SUSY 2025

18 Aug 2025, 08:15 → 23 Aug 2025, 19:00 US/Pacific

University of California at Santa Cruz

The Conferences on Supersymmetry and Unification of Fundamental Interactions (SUSY) are among the largest international events where particle physicists come together to discuss innovative ideas pertaining to fundamental interactions among elementary particles.

The aim of the SUSY conference is to review and discuss recent research related to supersymmetric theories and other approaches to physics beyond the Standard Model in all aspects, including formal theory, phenomenology, experiment, astroparticle physics and cosmology.

The University of California at Santa Cruz is responsible for organizing and hosting the 32nd International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 2025).

The conference will take place from Monday, August 18, 2025 until 1pm on Saturday, August 23, 2025.

The conference is preceded by the pre-SUSY summer school, Monday, August 11, 2025 to Friday, August 15, 2025. A link to the Pre-SUSY School 2025 webpage is given here: https://indico.cern.ch/event/1524531/.

Early bird Registration for SUSY will open on March 3, 2025. Early bird registration is now closed. Late registrations will still be possible until August 1, 2025.

Abstract submission for parallel session talks is closed.

 

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Explore Santa Cruz.pdf

SUSY 2025 Poster_Final.png

Monday 18 August

08:15 → 08:45 Registration

08:45 → 10:30 Plenary 1

08:45 Welcome Address by Chancellor Cynthia Larive

Speaker: Cynthia Larive (UC Santa Cruz)

08:50 Logistics

Speakers: Howard Haber (University of California,Santa Cruz (US)), Marco Battaglia (University of California,Santa Cruz (US)), Wolfgang Altmannshofer (UC Santa Cruz)

09:00 Opening Talk

Speaker: Sven Heinemeyer (CSIC (Madrid, ES))

09:30 Status of Weak Scale Supersymmetry, 2025

Speaker: Howard Baer

10:00 NMSSM

Speaker: Milada Margarete Mühlleitner

10:30 → 11:00 Coffee break

11:00 → 12:30 Plenary 2

11:00 SUSY searches in ATLAS

Speaker: David Miller (University of Chicago (US))

11:30 SUSY searches in CMS

Speaker: Valentina Dutta (Carnegie-Mellon University (US))

12:00 SUSY and Cosmology

Speaker: Keith A. Olive (University of Minnesota (US))

12:30 → 14:00 Lunch break

14:00 → 16:00 Plenary 3

Chair: Konstantin Matchev

Convener: Konstantin Matchev (University of Alabama (US))

14:00 Machine Learning in Particle Physics

Speaker: David Shih

14:30 TBD

Speaker: TBD

15:00 TBD

Speakers: Prof. John Ellis (Kings College London), John Ellis (CERN)

15:30 SUSY and QCD

Speaker: Csaba Csaki (Cornell University)

16:00 → 16:30 Coffee break

16:30 → 18:00 Plenary 4

16:30 Recent Developments in Amplitudes

Speakers: Anastasia Volovich (Brown University), Anastasia Volovich, Anastasia Volovich (Brown University (US))

17:00 Exotic Symmetries

Speaker: Shu-Heng Shao (MIT)

17:30 Random Matrix Theory and Supergravity

Speaker: Clifford Johnson

18:30 → 20:30 Welcome Reception / Dinner

Tuesday 19 August

08:30 → 09:00 Registration

09:00 → 10:30 Plenary 5

09:00 Swampland

Speaker: Hirosi Ooguri

09:30 SUSY and Black Holes

Speaker: Victor Luca Iliesiu

10:00 Black Holes as Dark Matter Candidates

Speaker: ALEXANDER KUSENKO

10:30 → 11:00 Coffee break

11:00 → 12:30 Plenary 6

11:00 Dark Matter Theory

Speaker: Tracy Slatyer

11:30 Overview of Dark Matter Experiments

Speaker: Theresa Fruth (University of Sydney)

12:00 Dark Matter at Accelerator Experiments

Speaker: Natalia Toro (SLAC)

12:30 → 14:00 Lunch break

14:00 → 16:00 Supersymmetry phenomenology and experiment

Conveners: Isabell Melzer-Pellmann (Deutsches Elektronen-Synchrotron (DE)), Jason Evans (Shanghai Jiaotong University/TDLI), Jeff Shahinian (University of Pennsylvania (US)), Krzysztof Rolbiecki (University of Warsaw)

14:00 Searches for supersymmetry in non-minimal models with ATLAS

Supersymmetry (SUSY) provides elegant solutions to several problems in the Standard Model, and searches for SUSY particles are an important component of the LHC physics program. With increasing mass bounds on MSSM scenarios other non-minimal variations of supersymmetry become increasingly interesting. This talk will present the latest results of searches conducted by the ATLAS experiment targeting strong and electroweak production in R-parity-violating models, as well as non-minimal-flavour-violating models. Recent results and interpretations in the context of the pMSSM are also presented.

Speaker: Hoang Dai Nghia Nguyen (Université de Montreal (CA))

14:20 Searches for Supersymmetry with compressed scenarios

Results from the CMS experiment are presented for supersymmetry searches targeting so-called compressed spectra, with small mass splittings between the different supersymmetric partners. Such a spectrum presents unique experimental challenges. This talk describes the new techniques utilized by CMS to address such difficult scenarios and presents results based on these techniques.

Speaker: Margaret Rose Lazarovits (The University of Kansas (US))

14:40 Visible Collider Signals of Natural Quirks in Folded SUSY

Electroweak states below the TeV scale, motivated by Folded SUSY and confined by a new SU(3) gauge group, can still be discovered at the LHC. We show that masses as low as $100~{\rm GeV}$ evade current searches. Also, we propose using displaced vertex searches and a novel strategy as methods for discovery at the high-luminosity LHC.

Speaker: Joshua Forsyth (Brigham Young University)

15:00 Using MTN to study multiply-produced semi-invisible resonances at hadron colliders

The stransverse mass variable MT2 was originally proposed for the study of SUSY-like events at hadron colliders in which N=2 parent particles are produced and then decay semi-invisibly. Here we consider the generalization to the case of N≥3 semi-invisibly decaying parent particles. We introduce the corresponding class of kinematic variables MTN and illustrate their mathematical properties. Many of the celebrated features of the MT2 kinematic endpoint are retained in this more general case, including the ability to measure the mass of the invisible daughter particle from the stransverse mass kink.

Speaker: Konstantin Matchev (University of Alabama (US))

15:20 Machine Learning Analysis of Radiative Neutralino Decay searches at the LHC

The search for weakly interacting matter particles (WIMPs) is one of the main objectives of the High Luminosity Large Hadron Collider (HL-LHC). In this work we use Machine-Learning (ML) techniques to explore WIMP radiative decays into a Dark Matter (DM) candidate in a supersymmetric framework. The minimal supersymmetric WIMP sector includes the lightest neutralino that can provide the observed DM relic density through its co-annihilation with the second lightest neutralino and lightest chargino. Moreover, the direct DM detection cross section rates fulfill current experimental bounds and provide discovery targets for the same region of model parameters in which the radiative decay of the second lightest neutralino into a photon and the lightest neutralino is enhanced. This strongly motivates the search for radiatively decaying neutralinos which, however, suffers from strong backgrounds. We investigate the LHC reach in the search for these radiatively decaying particles by means of cut-based and ML methods and estimate its discovery potential in this well-motivated, new physics scenario.

Speaker: Carlos Wagner

15:40 Statistically Learning New Physics from LHC Data

Despite the large amount of data produced by the Large Hadron Collider (LHC), no clear evidence of New Physics (NP) has emerged so far. Most LHC searches target exclusive channels, focusing on specific final states, but NP may appear as a dispersed signal across many channels. This motivates a more global approach to finding out where beyond the Standard Model physics might be hiding. We present a statistical learning algorithm designed to identify such dispersed signals in the slew of published LHC analyses. The algorithm constructs candidate "proto-models", precursors to a possible next Standard Model, from small excesses in the data, while remaining consistent with negative results on NP.

In this talk, I will outline our method and highlight recent algorithmic advancements that goes beyond the initial concept published previously. Furthermore, I will share preliminary results obtained by applying this framework to the latest SModelS database, which aggregates around 110 published experimental analyses.

Speaker: Mohammad Mahdi Altakach (LPSC)

14:00 → 16:00 Dark matter, Astroparticle, Gravitational waves

Conveners: Gilly Elor, Maria Martinez (Universidad de Zaragoza), Nicholas Llewellyn Rodd (CERN), Nicholas Rodd (Lawrence Berkeley National Laboratory), Noah Kurinsky (SLAC/Stanford)

14:00 Latest results from the XENONnT experiment

XENONnT, located at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy, is a direct dark matter detection experiment designed to search primarily for Weakly Interacting Massive Particles (WIMPs) using a dual-phase xenon Time Projection Chamber (TPC). Thanks to its ultra-low background environment, the XENONnT detector is also sensitive to a variety of other rare-event physics channels.
In this talk, I will present the latest results from the XENONnT experiment, including an overview of the WIMP search based on the combined data from the first two science runs. I will also summarize the Coherent Elastic neutrino-Nucleus Scattering (CE$\nu$NS) analysis, which has led to the first observation of astrophysical neutrinos using a ton-scale detector.

Speaker: Lorenzo Principe (SUBATECH & University of Melbourne)

14:20 Unraveling the DAMA/LIBRA Puzzle: last results from the ANAIS-112 Experiment

For over two decades, the DAMA/LIBRA experiment has reported an annual modulation in the low-energy region, consistent with the expectation from dark matter (DM) in the galactic halo due to Earth's motion around the Sun. For most WIMP candidates, this result is excluded by the null results of other experiments, making it one of the most puzzling anomalies in the field. However, such comparisons are model-dependent, as these experiments use different target materials with respect to DAMA/LIBRA (NaI(Tl) scintillators).
In recent years, the ANAIS-112 and COSINE-100 experiments, which also employ NaI(Tl) detectors, have obtained results that are incompatible with those of DAMA/LIBRA at a high confidence level, leaving little room for a DM interpretation of the observed modulation.
The ANAIS-112 experiment uses 112.5 kg of NaI(Tl) detectors at the Canfranc Underground Laboratory and it has been taking data since August 2017. In this talk we will present the results of the annual modulation analysis corresponding to six years of ANAIS–112 data, that are the most sensitive to date with the same target material. Results are incompatible with the DM interpretation of the DAMA/LIBRA modulation signal at a 4$\sigma$ confidence level. We will also review the systematic uncertainties affecting the comparison, particularly those related to the response of detectors to nuclear recoils.

Speaker: Maria Martinez

14:40 Search for Baryogenesis and Dark Matter in $B$-meson decays at $BABAR$

We present the most recent $BABAR$ searches for reactions that could simultaneously explain the presence of dark matter and the matter-antimatter asymmetry in the Universe. This scenario predicts exotic $B$-meson decays of the kind $B\to\psi_{D} {\cal B}$, where $\cal{B}$ is an ordinary matter baryon (proton, $\Lambda$, or $\Lambda_c$) and $\psi_D$ is a dark-sector anti-baryon, with branching fractions accessible at the $B$ factories. The hadronic recoil method has been applied with one of the $B$ mesons from $\Upsilon(4S)$ decay fully reconstructed, while only one baryon is present in the signal $B$-meson side. The missing mass of signal $B$ meson is considered as the mass of the dark particle $\psi_{D}$. Stringent upper limits on the decay branching fraction are derived for $\psi_D$ masses between 0.5 and 4.3 GeV/c$^2$. The results are based on the full data set of about 470 million $B-\overline B$ pairs collected at the $\Upsilon(4S)$ resonance by the $BABAR$ detector at the PEP-II collider

Speaker: Massimo Carpinelli (University of Milano Bicocca and INFN)

15:00 Searches for dark sector particles at Belle and Belle II

The Belle and Belle II experiment have collected samples of $e^+e^-$ collision data at centre-of-mass energies near the $\Upsilon(nS)$ resonances. These data have constrained kinematics and low multiplicity, which allow searches for dark sector particles in the mass range from a few MeV to 10 GeV. Using a 365 fb$^{-1}$ sample collected by Belle II, we search for inelastic dark matter and an $Z^{\prime}$ that decays to invisible particles. In addition, we search for the dark photon decay $A^{\prime}\to \mu^+\mu^-$ using the full Belle II data set of $500~fb^{-1}$ Using a 711 fb$^{-1}$ sample collected by Belle, we search for $B\to h + \mathrm{invisible}$ decays, where $h$ is a $\pi$, $K$, $D$, $D_{s}$ or $p$, and $B\to Ka$, where $a$ is an axion-like particle.

Speaker: Paolo Branchini (Universita e INFN Roma Tre (IT))

15:20 Recent highlights of dark matter searches from CMS

Determination of the nature of dark matter is one of the most fundamental problems of particle physics and cosmology. This talk presents recent searches for dark matter particles from the CMS experiment at the Large Hadron Collider.

Speaker: Leonardo Favilla (Scuola Superiore Meridionale & INFN - Sezione di Napoli (IT))

15:40 Exploring new physics in the Dark Sector at CMS

Among the intriguing scenarios of new physics that provide explanation to several shortcomings of the Standard Model (SM), hidden valley scenarios include a Dark Sector that extends the SM with a non-Abelian gauge group, similar to quantum chromodynamics with new matter and gauge fields analogous to the SM quark and gluon fields. This may result in a rich phenomenology which we can access through portal interactions. In this talk we present the most recent results from CMS that explore such Dark Sectors by exploiting dedicated data streams and innovative usage of the CMS detector. We focus on the recent results obtained using the full Run-II data-set collected at the LHC.

Speaker: Tamas Almos Vami (Univ. of California Santa Barbara (US))

14:00 → 16:00 Cosmology and the early Universe: Chair

Conveners: Elisabeth Krause (The University of Arizona), Kai Schmitz (Westfaelische Wilhelms-Universitaet Muenster (DE)), Prof. Kimberly Boddy (University of Texas at Austin), Sarunas Verner (University of Florida)

14:00 Self Consistent Thermal Resummation: A Case Study of the Phase Transition in 2HDM

An accurate description of the scalar potential at finite temperature is crucial for studying cosmological first-order phase transitions (FOPT) in the early Universe. At finite temperatures, a precise treatment of thermal resummations is essential, as bosonic fields encounter significant infrared issues that can compromise standard perturbative approaches. The Partial Dressing (or the tadpole resummation) method provides a self consistent resummation of higher order corrections, allowing the computation of thermal masses and the effective potential including the proper Boltzmann suppression factors and without relying on any high-temperature approximation. We systematically compare the Partial dressing resummation scheme results with the Parwani and Arnold Espinosa (AE) ones to investigate the thermal phase transition dynamics in the Two-Higgs-Doublet Model (2HDM). Our findings reveal that different resummation prescriptions can significantly alter the nature of the phase transition within the same region of parameter space, confirming the differences that have already been noticed between the Parwani and AE schemes. Notably, the more refined resummation prescription, the Partial Dressing scheme, does not support symmetry non-restoration in 2HDM at high temperatures observed using the AE prescription. Furthermore, we quantify the uncertainties in the stochastic gravitational wave (GW) spectrum from an FOPT due to variations in resummation methods, illustrating their role in shaping theoretical predictions for upcoming GW experiments. Finally, we discuss the capability of the High-Luminosity LHC and proposed GW experiments to probe the FOEWPT-favored region of the parameter space.

Speaker: Dr Subhojit Roy (Argonne National Laboratory)

14:20 What happens when supercooling is terminated by curvature flipping of the effective potential?

We explore the nature of a certain type of supercooled phase transition, mainly motivated by supersymmetric theories, where the supercooling is guaranteed to end due to the curvature sign flipping of the finite-temperature effective potential at the origin. In such models, the potential barrier trapping the scalar field at the metastable origin quickly vanishes at the temperature scale of the phase transition. It is therefore not immediately clear if critical bubbles are able to form, or whether the field will simply transition over the barrier and smoothly roll down to the true minimum. To address this question, we perform lattice simulations of a scalar potential exhibiting supercooling, with a small barrier around the origin, and qualitatively determine the fate of the phase transition. Our simulations indicate that, owing to the required flatness of the potential, the scalar field remains trapped around the origin such that the phase transition generically proceeds via the nucleation and expansion of true-vacuum bubbles. We comment on the possible gravitational wave signals one might expect in a concrete toy model and discuss the parameter space in which bubble percolation is and isn't expected.

Speaker: Dr Tae Hyun Jung (Institute for Basic Science)

14:40 Gravitational Waves as Cosmic Tracers of Leptogenesis

Gravitational Waves (GWs) offer a powerful window into the physics of the early Universe and could provide a novel probe of high-scale leptogenesis models. In this talk, I will explore how GW observations can shed light on a class of GUT-inspired seesaw models based on the $U(1)_{B-L}$ gauge symmetry. In these scenarios, the scalar field $\Phi$ responsible for the spontaneously breaking of $U(1)_{B-L}$ generates Majorana masses $M_N$ for right-handed neutrinos. Moreover, when the scalar field couples only feebly to the Standard Model Higgs, it naturally induces a period of early matter domination that is intimately connected to the leptogenesis scale $M_N$ and, therefore, encodes valuable information about different regimes of flavored leptogenesis. In this framework, GWs are produced both by the cosmic strings associated with the breaking of the gauge symmetry $U(1)_{B-L}$ and by the amplification of primordial density fluctuations during the early matter-dominated era. I will demonstrate how the amplitude and the spectral features of the resulting GW background are shaped by the underlying leptogenesis scale $M_N$. A future GW detection across multiple frequency bands could thus offer unique insights into the origin of the matter-antimatter asymmetry. Even in the absence of a signal, stringent constraints could be placed on the leptogenesis parameter space—constraints that are otherwise inaccessible through conventional probes.

Speaker: Marco Chianese (Scuola Superiore Meridionale & INFN)

15:00 Leptogenesis and Neutrinoless Double-Beta Decay

We revisit the thermal leptogenesis based on the Type I seesaw mechanism and discuss the constraints from future neutrino experiments. We especially focus on the impact of the neutrinoless double-beta decay. Numerically solving the density matrix equation, which can describe the flavor effects, we present the lower bounds of right-handed neutrino mass required for successful leptogenesis as a contour plot on a plane of the lightest neutrino mass and the effective Majorana neutrino mass for the neutrinoless double-beta decay. By taking a projection, we also present the lower bound as a function of the effective Majorana neutrino mass.

Speaker: Mr Tatsuya Yokoyama (University of Tokyo)

15:20 Flavored Leptogenesis with MeV–GeV Dark Matter

We explore flavored resonant leptogenesis embedded in a neutrinophilic 2HDM. Successful leptogenesis is achieved by the very mildly degenerate two heavier right-handed neutrinos~(RHNs) $N_2$ and $N_3$ with a level of only $\Delta M_{32}/M_2 \sim \mathcal{O}(0.1\%-1\%)$. The lightest RHN, with a MeV–GeV mass, lies below the sphaleron freeze-out temperature and is stable, serving as a dark matter candidate. The model enables TeV-scale leptogenesis while avoiding the extreme mass degeneracy typically plagued conventional resonant leptogenesis. Baryon asymmetry, neutrino masses, and potentially even dark matter relic density can be addressed within a unified, experimentally testable framework.

Speaker: Kairui Zhang (University of Oklahoma-Norman)

15:40 Leptogenesis from magnetic helicity of gauged U(1)_{B-L}

If the $B-L$ symmetry is gauged with the addition of right-handed neutrinos, the standard model $B-L$ current is anomalous with respect to the $B-L$ gauge field itself. Then, the anomaly relation implies that the magnetic helicity of the $B-L$ gauge field is related to the standard model $B-L$ charges, although the whole universe is $B-L$ neutral with right-handed neutrinos. Based on this, we propose a new leptogenesis scenario with the gauged $B-L$ symmetry as follows. First, the magnetic helicity of the $B-L$ gauge field is generated, e.g., by the axion inflation, together with the standard model and right-handed neutrino $B-L$ charges, with the net $B-L$ charge kept zero. The $B-L$ charges in the standard model and right-handed neutrino sectors are then subject to washout effects from the interactions between them. After the washout effects decouple, the $B-L$ gauge symmetry is Higgsed and the magnetic helicity of the $B-L$ gauge field decays and generates $B-L$ charges in the both sector; thanks to the washout effects, we obtain a non-zero $B-L$ asymmetry. We show that the baryon asymmetry of the universe can be generated in this scenario, discussing the decay of the magnetic helicity of the $B-L$ gauge field and the interactions between the right-handed neutrinos and the standard model particles. We also discuss gauge (non-)invariance of the $B-L$ magnetic helicity and its possible implication.

Speaker: Hajime Fukuda

14:00 → 16:00 Flavor physics and neutrinos

Conveners: Dean Robinson (Lawrence Berkeley National Laboratory (LBL)), Eluned Anne Smith (Massachusetts Inst. of Technology (US)), Shirley Li (UC Irvine), Yun-Tse Tsai (SLAC), Yun-Tse Tsai (SLAC National Accelerator Laboratory (US)), Yun-Tse Tsai (SLAC National Accelerator Laboratory (US))

14:00 TeV-scale scalar leptoquarks solve shortcomings of SO(10) and explain the flavor anomalies

It is common practice to explain deviations between data and Standard-Model predictions by postulating new particles at the TeV scale ad-hoc. This approach becomes much more convincing, if one successfully embeds the postulated particles into a UV completion which addresses other conceptual or phenomenological shortcomings of the SM. I present a study of an SO(10) grand unified theory which contains scalar leptoquark fields employed to explain the “flavor anomalies” in $b\rightarrow s$ and $b\rightarrow c$ decays. I find that the additional degrees of freedom improve the renormalization group evolution of the SM parameters and may explain some of the observed fermion masses.

Speaker: Xiyuan Gao (KIT, Karlsruhe, TTP)

14:20 New measurement of $K^{+} \rightarrow \pi^{+}\nu\bar{\nu}$ branching ratio at the NA62 experiment

The $K^{+}\rightarrow\pi^{+}\nu\bar{\nu}$ decay is a golden mode for flavour physics. Its branching ratio is predicted with high precision by the Standard Model to be less than $10^{-10}$, and this decay mode is highly sensitive to indirect effects of new physics up to the highest mass scales. A new measurement of the $K^{+}\rightarrow\pi^{+}\nu\bar{\nu}$ decay by the NA62 experiment at the CERN SPS is presented, using data collected in 2021 and 2022. This new dataset was collected after modifications to the beamline and detectors and at a higher instantaneous beam intensity with respect to the previous 2016--2018 data taking. Using the NA62 datasets from 2016--2022, a new measurement of $\mathcal{B}(K^{+}\rightarrow\pi^{+}\nu\bar{\nu}) = \left(13.0^{+ 3.3}_{- 2.9} \right)\times 10^{-11} $ is reported, and for the first time the $K^{+}\rightarrow\pi^{+}\nu\bar{\nu}$ decay is observed with a significance exceeding $5\sigma$.

Speaker: Jonathan Leon Schubert (Max Planck Society (DE))

14:40 Targets for Flavor-Violating Top Decay

Analyticity and unitarity constrain broad classes of new physics models by linking flavor-conserving and flavor-violating four-fermion interactions. In this work, we explore how these theoretical relations impact flavor-violating rare top quark decays. Building on our previous results, we present an updated analysis of the decays $t \to q \ell^+ \ell^-$ and identify interesting target branching ratios in the range of $10^{-7}$ to $10^{-6}$ once current experimental constraints from flavor-conserving processes are taken into account. We extend the analysis to top decays with lepton flavor violation, deriving correlations among the relevant Wilson coefficients and confronting them with existing limits from LEP and the LHC. Notably, we find that current searches for $t \to q e \mu$ are already probing theoretically motivated regions of parameter space. These results strongly support continued efforts to explore flavor-violating top decays as a powerful probe of new physics.

Speaker: Christopher Donohue (University of California, Santa Cruz)

15:00 Searches for lepton-flavour violation at Belle and Belle II

The Belle and Belle II experiments have collected a $1.6~\mathrm{ab}^{-1}$ sample of $e^+e^-$ collision data at centre-of-mass energies near the $\Upsilon(nS)$ resonances. This sample contains approximately 1.5 billion $e^+e^-\to \tau^+\tau^{-}$ events, which we use to search for lepton-flavour violating decays. We present searches for $\tau\to\ell\gamma$, tau decay to three charged leptons, $\tau^-\to K_{\rm S}^0\ell^{-}$, $\tau^-\to \ell^-\alpha$, where $\alpha$ is an invisible scalar particle. Further, 75% of these data are collected at a center-of-mass energy corresponding to the $\Upsilon(4S)$ resonance, which decays almost exclusively to $B\bar{B}$ pairs. We present results of several searches for non-standard-model $B\to K^{(*)}\tau \ell$ decays. Finally, we present searches for lepton-flavour-violation in bottomonium decay.

Speaker: Paolo Branchini (Universita e INFN Roma Tre (IT))

15:20 Simulating Heavy Neutral Leptons with General Couplings at Collider and Fixed Target Experiments

Heavy Neutral Leptons (HNLs) are a well-motivated extension of the Standard Model which may provide explanations for observed neutrino masses, dark matter, and baryogengesis via leptogenesis. In this work, we present a user-friendly, fast, and flexible python library, HNLCalc, with over 150 HNL production channels and 100 HNL decay modes, which allows for the calculation of production and decay rates of HNLs between 100 MeV and 10 GeV with arbitrary couplings to electron, muon, and tau neutrinos. We use this library to extend the existing FORESEE simulation package to study the discovery prospects for the standard PBC benchmarks, Ue:Umu:Utau = 1:0:0, 0:1:0, and 0:0:1, as well as the more recently proposed and better motivated benchmarks 0:1:1 and 1:1:1. We present sensitivity reaches for FASER and FASER2 in comparison with current experimental constraints and find that our projections extend into currently unconstrained regions of parameter space for HNLs in the 2 to 3.5 GeV mass range.

Speaker: Daniel La Rocco

15:40 .

16:00 → 16:30 Coffee break

16:30 → 18:30 Supersymmetry phenomenology and experiment

Conveners: Isabell Melzer-Pellmann (Deutsches Elektronen-Synchrotron (DE)), Jason Evans (Shanghai Jiaotong University/TDLI), Jeff Shahinian (University of Pennsylvania (US)), Krzysztof Rolbiecki (University of Warsaw)

16:30 Aspects of the WIMP quality problem and R-parity violation in natural supersymmetry with all axion dark matter

In supersymmetric models where the mu problem is solved via discrete R-symmetries, then both the global $U(1)_{PQ}$ (Peccei-Quinn, needed to solve the strong CP problem) and R-parity conservation (RPC, needed for proton stability) are expected to arise as accidental, approximate symmetries. Then in some cases, SUSY dark matter is expected to be all axions since the relic lightest SUSY particles (LSPs) can decay away via small R-parity violating (RPV) couplings. We examine several aspects of this {\it all axion} SUSY dark matter scenario. 1. We catalogue the operator suppression which is gained from discrete R-symmetry breaking via four two-extra-field base models. 2. We present exact tree-level LSP decay rates including mixing and phase space effects and compare to results from simple, approximate formulae. 3. Natural SUSY models are characterized by light higgsinos with mass ~100-350 GeV so that the dominant sparticle production cross sections at LHC14 are expected to be higgsino pair production which occurs at the $10^2-10^4$ fb level. Assuming nature is natural, the lack of an RPV signal from higgsino pair production in LHC data translates into rather strong upper bounds on nearly all trilinear RPV couplings in order to render the SUSY signal (nearly) invisible. Thus, in natural SUSY models with light higgsinos, the RPV-couplings must be small enough that the LSP has a rather high quality of RPC.

Speaker: Kairui Zhang (University of Oklahoma-Norman)

16:50 Implications of purity constraints on higgsino dark matter

A higgsino could be some or all of the dark matter, with a mass bounded from above by about 1.1 TeV assuming a thermal freezeout density, and from below by collider searches. Direct detection experiments imply purity constraints on a dark matter higgsino, limiting the mixing with the electroweak gauginos. Using the new strong limits available as of the end of 2024 from the LUX-ZEPLIN experiment, I quantify the resulting lower bounds on gaugino masses and upper bounds on higgsino mass splittings, assuming that the scalar superpartners and Higgs bosons of minimal supersymmetry are in the decoupling limit. Similar bounds are projected for the critical future scenario that direct detection experiments reach the neutrino fog that hampers discovery prospects.

Speaker: Stephen Martin

17:10 Status and Recent Results from the LUX-ZEPLIN Dark Matter Experiment

LUX-ZEPLIN (LZ) is a direct detection dark matter experiment located nearly a mile underground at the Sanford Underground Research Facility in South Dakota, USA, employing 7 tonnes of active liquid xenon in a dual-phase time projection chamber (TPC). It is further surrounded by a veto system that includes a 2-tonne liquid xenon skin, a gadolinium-loaded liquid scintillator, and an ultra-pure water tank. The experiment has been taking data since 2021, and in 2024 released world-leading constraints on WIMP-nucleon cross-sections for WIMP masses > 9 GeV/c2. This talk will discuss the status of the LZ experiment and report on its recent science results with a specific emphasis on the dark matter parameter space being probed.

Speaker: Daniel Kodroff (Lawrence Berkeley National Lab)

17:30 Primordial Black Holes and Gravity Wave Signatures of Resonant Nonequilibrium ALP dynamics

In the context of out of equilibrium radial field dynamics during inflation, ALPs can attain resonantly enhanced perturbation amplitudes. We present how such enhanced amplitudes can lead to a boost in primordial dark matter fraction as well as gravity waves observable by existing and future gravity wave detectors. SUSY embeddings of this class of scenarios will also be discussed.

Speaker: DANIEL CHUNG

17:50 A Dual to Ordinary Matter Yielding Composite Neutral Flavored Scalar Dark Matter

We discuss a Dual to ordinary matter that yields composite self-interacting dark matter. For each elementary particle inn the SM, the Dual:
1. Changes spin by ½, i.e. a SUSY-lite;
2. U(1): Changes electric charge e to magnetic charge g with g=e/; to avoid non-integer magnetic charge the up and down squark sectors have g=+3g and -6g, the charged sleptons and Wino are charged 2g;
3. SU(2)L => SU(2)R – L/R handedness is interchanged along with weak charges. The Z cannot decay to pairs of dual particles, like sneutrinos, by handedness constraints.
4. SU(3): Changes chromoelectric charge to chromomagnetic charge, with chromocharges reciprocal, similar to electric/magnetic duality– no triple-gluino vertex, and an effectives for chromomagnetic squarks is weak and runs oppositely; pseudoscalar squarks interact by exchange of gluino-loops yielding a weak Yukawa interaction.
5. Flavors remain the same in the Dual.
6. Up to tree level and field energy corrections, the dual masses are the same as the SM; in effect, flavor and mass describe the same property with respect to the Higgs.
7. The masses of the Higgs and Higgsino are stabilized, as the top and magnetic scalar stop have the same masses. Similarly, there is no need for R-parity, as there are no diagrams where magnetically charged squarks can lead to proton decay.
Consequences: the charged dual particles are confined as magnetically and chromomagnetically stable neutral shadrons, or slepton-pair monopoliums with long lifetimes. When pair-produced from the SM, monopoles dress themselves to neutral monopolium in analogous ways to chromoelectric confinement and escape, enabled by the low mass squarks and sleptons, like the low mass squarks. We discuss how present limits on monopoles evade detection when pair-produced, and the consequences of CP violation on pair-production of magnetic scalars. Because the down/up sector squarks charges are -6g/+3g and Wino charge 2g, the weak magnetic current is shut off as 2g cannot change +3g to -6g, leading to 6 stable neutral flavored smesons and to 27 stable neutral flavored sbaryons, with hundreds of other multiple component neutral dual sector configurations, resulting in a surprisingly large spectrum of dark matter composite light neutral flavored particles. It is reasonable that the strength of magnetic forces would create much more dark magnetic matter than electric matter in the early epoch. The photon is in effect divided into 2 classes: photons emitted from electric particles couple to magnetic particles as g, whereas photons emitted from magnetic particles couple as e, which interact with SM matter weakly for photon energies less than ~10 MeV in the lab frame, effectively dark photons. Such photons with ~few eV energies would be largely invisible in cameras, for example from dim galaxies, and at 10’s MeV’s in calorimeters or satellite x-ray detetectors. Considering the magnetic binding energies ~ TeV, resolving the charges in stable neutral flavored monopoliums requires very large energies, such as associated with cosmic rays. Production cross-sections for stable neutral monopoliums from electric matter is discussed as is magnetic matter in the cosmos. Hints of this dual in existing accelerator, cosmic ray data, in present anomalies and neutrino oscillations, and consequences for massless photinos are presented.

Speaker: Prof. David Winn (Fairfield University)

18:10 .

16:30 → 18:30 Higgs theory and experiment

Conveners: Johannes Braathen (DESY), Marko Stamenkovic (Brown University (US)), Tania Robens (Rudjer Boskovic Institute (HR)), Tatjana Lenz (University of Bonn (DE))

16:30 Resonant Di-Higgs Production at the LHC: Theory vs. Experiment

ATLAS and CMS are searching for resonant di-$h_{125}$ production, where the $m_{hh}$ distributions are key. Within UV-complete models we compare the experimental procedure with the theoretical predictions. For parameter regions allowed by all current theoretical and experimental constraints, we find that the experimental limits cannot be readily applied to concrete model realizations. We stress the relevance of higher-order corrections to triple Higgs couplings in this context that can substantially change the tree-level predictions.

Speaker: Milada Margarete Mühlleitner

16:50 BSM Di-Higgs Production in the RxSM

We discuss di-Higgs production in the SM extended by a real singlet, RxSM. The RxSM is the simplest model that can yield a Strong First Order Electroweak Phase Transition (SFOEWPT) in the early universe. We concentrate on the regions yielding a SFOEWPT, including higher-order corrections to the triple Higgs couplings, which can be substantial. We discuss the sensitivity of the HL-LHC and high-energy $e^+e^-$ colliders (such as ILC or CLIC) to BSM triple Higgs couplings.

Speaker: Sven Heinemeyer (CSIC (Madrid, ES))

17:10 HH searches and higgs-self couplings measurements by ATLAS

In the Standard Model, the ground state of the Higgs field is not found at zero but instead corresponds to one of the degenerate solutions minimising the Higgs potential. In turn, this spontaneous electroweak symmetry breaking provides a mechanism for the mass generation of nearly all fundamental particles. Experimentally, the Higgs boson self-couplingm and thereby the shape of the Higgs potential, can be probed through the production of Higgs boson pairs (HH). In this talk, the latest HH searches by the ATLAS experiment using the LHC Run 2 and Run 3 datasets are reported. Non-resonant HH search results are interpreted both in terms of sensitivity to the Standard Model and as limits on the Higgs boson self-coupling and the quartic VVHH coupling. Additionally, extrapolations of recent HH results towards the High Luminosity LHC upgrade are also discussed. Many new physics models predict the existence of resonances decaying into two bosons, including the Higgs boson or new scalar S bosons making these important signatures in the search for new physics. Searches for HH or SH resonances performed in various final states are also presented.

Speaker: Cecilia Tosciri (University of Chicago (US))

17:30 Di-Higgs searches at CMS

The measurement of the production of Higgs boson pairs (HH) at the LHC allows the exploration of the Higgs boson interaction with itself and is thus a fundamental test of the Standard Model theory and has a key role in the determination of the Higgs boson nature. The most recent results from the CMS collaboration on measurements of non-resonant HH production using different final states and their combination using the data set collected by the CMS experiment will be presented.

Speaker: Tamas Almos Vami (Univ. of California Santa Barbara (US))

17:50 .

18:10 Measurement of BSM Triple Higgs Couplings using a Neural Network

We demonstrate that a BSM triple Higgs coupling (THC) can possibly be measured at the HL-LHC using a Neural Network (NN). We take the 2HDM as concrete example, take into account all current theoretical and experimental constraints, as well as anticipated future experimental uncertainties. Depending on the mass of the involved BSM Higgs-boson and the value of the THC realized in nature, a determination of the BSM THC at the 10-20% level may be possible.

Speaker: Sven Heinemeyer (CSIC (Madrid, ES))

16:30 → 18:30 Dark matter, Astroparticle, Gravitational waves

Conveners: Gilly Elor, Maria Martínez (Universidad de Zaragoza (ES)), Nicholas Llewellyn Rodd (CERN), Nicholas Rodd (Lawrence Berkeley National Laboratory), Noah Kurinsky (SLAC/Stanford)

16:30 Genesis of Baryon and Dark Matter Asymmetries through Ultraviolet Scattering Freeze-in

We introduce a new mechanism for the simultaneous generation of baryon and dark matter asymmetries through ultraviolet-dominated freeze-in scatterings. The mechanism relies on heavy Majorana neutrinos that connect the visible Standard Model sector to a dark sector through the neutrino portal. Following reheating of the visible sector to a temperature well below the heavy neutrino masses, we show that 2-to-2 scattering processes can populate the dark sector and generate both baryon and dark matter asymmetries. In some parameter regions, the dominant source of baryon asymmetry can be charge transfer from the dark sector, a process we call dark wash-in. We also demonstrate that annihilation of the dark matter to massless states within the dark sector can deplete the symmetric population without destroying the net baryon charge to leave only an asymmetric dark matter abundance today. Depending on the specific model parameters, the observed baryon and dark matter abundances can be attained with dark matter masses in the range 0.1 GeV ≲mχ≲103≲mχ​≲10^3 GeV if the dark matter relic abundance is mainly asymmetric and even lower masses if it is symmetric.

Speaker: Pouya Asadi (University of Oregon)

16:50 Higgs-Portal Spin-1 Dark Matter with Parity-Violating Interaction

We introduce the spin-1 $U(1)_X$ gauged field $X$ with $Z_2$ odd dark parity to evade the current strong constraints on kinetic mixing. Then, $X$ becomes stable and a candidate for the dark matter. The lowest mass dimension of interaction is six, and the type is the Higgs portal. Two types of dim-$6$ operators are introduced. We consider the freeze-out dark matter scenario. With the limit of null momentum transfer, a parity odd operator is free from the direct detection constraints. Accordingly, the strong constraints on a parity even operator indicate turning on this parity odd operator to realize the dark matter relic density of the Universe. With the $1$ TeV cut-off scale, our dark matter of around $400$ GeV mass can explain the dark matter relic density and is allowed from the LUX-ZEPLIN experiment of the direct detection.

Speaker: Prof. Kimiko Yamashita (Ibaraki University)

17:10 Gamma-Ray and Gravitational Wave Signals of Inelastic Higgs Portal Dark Matter

We explore a simple and predictive dark matter scenario involving a complex scalar field, $\phi$, coupled to the Higgs portal with no additional field content. In the UV, the field possesses a global $U(1)$ symmetry which is broken by mass terms and Higgs portal interactions. In the mass basis, the complex field splits into a pair of real scalars with a small mass splitting (in analogy with pseudo-Dirac fermions), such that the Higgs portal acquires both diagonal and off-diagonal terms with respect to these eigenstates. In the parameter space where the off-diagonal interaction predominates, this scenario is safe from all existing direct detection constraints. Moreover, this model provides a viable explanation for the longstanding Galactic Center gamma-ray excess. Additionally, this model influences the Higgs potential in a way that could lead to a strong first-order electroweak phase transition, potentially generating a stochastic gravitational wave signal that could fall within the reach of upcoming space-based detectors.

Speaker: Dr Subhojit Roy (Argonne National Laboratory)

17:30 Light Dark Pions from a SO(NDC) confining Dark Sector

This work extends a BSM scenario based on a dark color gauge group SO($N_{\mathrm{DC}}$), with a vector-like heavy SU(2) doublet and one Majorana SM singlet, recently introduced by Antipin et al., and later investigated by Contino et al. We extend the dark flavour sector to two Majorana singlets and explore the possibility of the emergence of Dark Pions, pNGBs of spontaneous symmetry breaking in the dark flavour sector. Our analysis provides an effective description for energies below the confinement scale $\Lambda_{\mathrm{DC}}$ (and below the electroweak scale $\Lambda_{\mathrm{EW}}$). In general, resulting Dark Pions are meta-stable and can decay to the Standard Model states via 5- and 6-dimensional portal operators, leading to distinctive collider signatures like displaced vertices or missing energy, and offering a promising target for long-lived particle searches. However, the main focus of this talk will be on the Light Dark Pions mass regime, in which they are cosmologically stable and could play the role of a light Dark Matter component, produced via freeze-in process from SM states. Additionally, this scenario introduces a Dark Matter candidate—the lightest Dark Baryon—which is stabilized by an accidental $\mathbb{Z}_2$ symmetry.

Speaker: Karolina Filipowicz

17:50 Molecules for Dark Matter

Molecular crystals are apparently ideal candidates for the next generation of dark matter (DM) detectors. Their anisotropic responses to DM scattering allow the DM signal to be distinguished from the irreducible backgrounds, e.g. by searching for a sidereal daily modulation signal in a detector that rotates with the Earth (every 23.93 hours). Trans-stilbene ($C_{14}H_{12}$) is an excellent first example, with O(10%) daily modulation amplitudes. In this talk, I provide an update on the multi-gram-scale prototype experiment currently being assembled at Fermilab. I also present a simple, universal measure for quantifying the statistical power of a directionally sensitive counting experiment, to guide the search for target materials that are even more effective than trans-stilbene.

Speaker: Ben Lillard (University of Oregon)

18:10 Cross-sections and experimental signatures for detection of a well-defined dark matter WIMP

We report the following calculations for a recently proposed bosonic dark matter WIMP with well-defined interactions [1-4]: (1) the mass as determined by fitting to the relic abundance; (2) the current annihilation cross-section for indirect detection; (3) cross-sections for pair production accompanied by jets in proton colliders with center-of-mass energies ranging from 13 to 100 TeV; (4) for the high-luminosity LHC, and planned 100 TeV proton collider, detailed plots of experimentally accessible quantities before and after optimal cuts; (5) cross-sections, and plots of experimentally accessible quantities, for production in e$^+$e$^-$ or muon colliders with center-of-mass energies up to 10 TeV; (6)~cross-section per nucleon for direct detection. The conclusions are given in the text, including the principal prediction that (with optimal cuts) this particle should be detectable at the high-luminosity LHC, perhaps after only two years with an integrated luminosity of 500 fb$^{-1}$.}
[1] Reagan Thornberry et al., EPL [Europhysics Letters] 134, 49001 (2021), arXiv:2104.11715 [hep-ph].
[2] Bailey Tallman et al., proceedings of the 41st International Conference on High Energy Physics, ICHEP 2022, arXiv:2210.05380 [hep-ph].
[3] Bailey Tallman et al., Letters in High Energy Physics LHEP-342 (2023), arXiv:2210.15019 [hep-ph].
[4] Bailey Tallman, Jehu Martinez, Rohan Shankar, Kane Rylander, and Roland E. Allen, arXiv:2506.19719 [hep-ph] and in review.

Speaker: Roland Allen

16:30 → 18:30 Non-SUSY extensions of the Standard Model

Conveners: Cristián Peña (Fermi National Accelerator Lab. (US)), Karri Di Petrillo (University of Chicago), Pouya Asadi (University of Oregon), Zhen Liu

16:30 .

17:10 On the sensitivity of nuclear clocks to new physics

The recent demonstration of laser excitation of the 8 eV isomeric state of thorium-229 is a significant step towards a nuclear clock. The low excitation energy likely results from a cancellation between the contributions of the electromagnetic and strong forces. Physics beyond the Standard Model could disrupt this cancellation, highlighting nuclear clocks' sensitivity to new physics.

It is challenging to accurately predict the different contributions to nuclear transition energies and therefore of the sensitivity of a nuclear clock to new physics. We improve upon previous sensitivity estimates. First, by revisiting a classical geometric model of thorium-229. Second, by proposing a new d-wave halo model, inspired by effective field theory. For both approaches we show that poor sensitivity to new physics is unlikely. For the halo model we find that the nuclear clock's sensitivity to variations in the effective fine structure constant is enhanced by a factor of order 10,000.

Speaker: Gil Paz

17:30 Hydrogen 21cm Constraints on the Photon's Spin Scale

We explore the fundamental but untested possibility that the photon is a continuous spin particle (CSP) with a small but non-zero spin Casimir $\rho$. When $\rho\neq 0$, the familiar polarization modes of the photon transform non-trivially under Lorentz boosts, leading to deviations from familiar QED. Surprisingly, these deviations are strongest at low energy, but smoothly vanish in the $\rho\rightarrow 0$ limit. In this letter, we compute corrections to the hydrogen 21cm transition rate, which is expected to be particularly sensitive given the small hyperfine energy splitting $\omega$. We find deviations from QED $\propto \rho^2 \alpha^2/\omega^2$ at leading order, suggesting experimental constraints $\rho\lesssim 1$ meV. Building on this work, we expect that a range of other atomic, molecular, or condensed matter systems could be used to provide even more stringent tests of $\rho$ in electromagnetic interactions.

Speaker: Aidan Reilly (SLAC)

17:50 Direct deflection of Millicharged radiation

Millicharged particles are generic in theories of dark sectors. A cosmic or local abundance of them may be produced by the early universe, stellar environments, or the decay or annihilation of dark matter/dark energy. Furthermore, if such particles are light, these production channels result in a background of millicharged radiation. We show that light-shining-through-wall experiments employing superconducting RF cavities can also be used as ``direct deflection" experiments to search for this relativistic background. The millicharged plasma is first subjected to an oscillating electromagnetic field of a driven cavity, which causes charge separation in the form of charge and current perturbations. In turn, these perturbations can propagate outwards and resonantly excite electromagnetic fields in a well-shielded cavity placed nearby, enabling detection. We estimate that future versions of the existing Dark SRF experiment can probe orders of magnitude of currently unexplored parameter space, including millicharges produced from the Sun, the cosmic neutrino background, or other mechanisms that generate a thermal abundance with energy density as small as $10^{-4}$ that of the cosmic microwave background.

Speaker: Erwin Tanin (Stanford)

18:10 .

Wednesday 20 August

08:30 → 09:00 Registration

09:00 → 10:30 Plenary 7

09:00 String Model Building

Speakers: Stuart Raby (The Ohio State University), Prof. Stuart Raby (The Ohio State University)

09:30 Composite Higgs Models

Speakers: Stefania De Curtis (U), Stefania De Curtis (Universita e INFN, Firenze (IT))

10:00 Effective Field Theories

Speaker: Aneesh Vasant Manohar (Univ. of California San Diego (US))

10:30 → 11:00 Coffee break

11:00 → 12:30 Plenary 8

Chair: Carlos Wagner

Convener: Carlos Wagner

11:00 Higgs Theory

Speakers: Shinya KANEMURA (Osaka University), Shinya Kanemura

11:30 Sensitivity to beyond SM phenomena through the Higgs sector in ATLAS

12:00 The sensitivity to beyond SM phenomena through the Higgs sector in CMS

Speakers: Scott David Thomas (Rutgers State Univ. of New Jersey (US)), Scott Thomas

12:30 → 14:00 Lunch break

Thursday 21 August

08:30 → 09:00 Registration

09:00 → 10:30 Plenary 9

Chair: Gil Paz

Convener: Gil Paz

09:00 Muon g-2 Theory

Speaker: Aida El-Khadra (University of Illinois Urbana-Champaign)

09:30 Muon g-2 Experiment + Mu2e

Speakers: Yongyi Wu (University of Virginia), Yongyi Wu (University of Michigan)

10:00 Flavor Results from LHCb and Belle II

Speaker: Angelo Di Canto (Brookhaven National Laboratory (US))

10:30 → 11:00 Coffee break

11:00 → 12:30 Plenary 10

11:00 Flavor Theory

Speaker: Zoltan Ligeti (Lawrence Berkeley National Lab. (US))

11:30 Neutrino Theory

Speaker: Pedro Machado (Fermilab)

12:00 Neutrino Experiments

Speakers: Georgia Karagiorgi (University of Manchester), Georgia Karagiorgi (MIT), Georgia Karagiorgi

12:30 → 14:00 Lunch break

14:00 → 16:00 Supersymmetry phenomenology and experiment

Conveners: Isabell Melzer-Pellmann (Deutsches Elektronen-Synchrotron (DE)), Jason Evans (Shanghai Jiaotong University/TDLI), Jeff Shahinian (University of Pennsylvania (US)), Krzysztof Rolbiecki (University of Warsaw)

14:00 Searches for strong production of supersymmetric particles with ATLAS

Supersymmetry (SUSY) provides elegant solutions to several problems in the Standard Model, and searches for SUSY particles are an important component of the LHC physics program. Naturalness arguments favour supersymmetric partners of the gluons and third-generation quarks with masses light enough to be produced at the LHC. This talk will present the latest results of searches conducted by the ATLAS experiment which target gluino and squark production, including stop and sbottom, in a variety of decay modes.

Speaker: Takane Sano (Kyoto University (JP))

14:20 Recent searches for strong and electroweak production of SUSY particles with CMS

A wide variety of searches for strong and electroweak productionSupersymmetry have been performed by experiments at the Large Hadron Collider. In this talk, we present recent highlights from these searches.

Speaker: Aleesha Kallil Tharayil (Carnegie-Mellon University (US))

14:40 Searches for electroweak production of supersymmetric particles with ATLAS

The direct production of electroweak SUSY particles, including sleptons, charginos, and neutralinos, is a particularly interesting area with connections to dark matter and the naturalness of the Higgs mass. The small production cross-sections and challenging experimental signatures lead to difficult searches. This talk will highlight the most recent results of searches performed by the ATLAS experiment for supersymmetric particles produced via electroweak processes.

Speaker: Chihiro Kawamoto (Kyoto University (JP))

15:00 Soft-lepton excesses in EW SUSY searches: Interpretation in (GUT-based) SUSY scenarios

For the first time ATLAS and CMS report consistently about excesses in the search for EW SUSY particles, seen in two different search channels by each experiment. We interpret these excesses as the production of two light EW MSSM particles, yielding $M_1 \sim M_2$, i.e. not within "natural GUT-based scenarios". We also interpret these excesses in the NMSSM, where the relation $M_1 \sim M_2/2 \sim M_3/6$ can be retained, with the gluino mass beyond the LHC bounds.

Speaker: Sven Heinemeyer (CSIC (Madrid, ES))

15:20 Stealth and RPV SUSY searches with CMS

Since the classic searches for supersymmetry under R-parity conserving scenarios have not given any strong indication for new physics yet, more and more supersymmetry searches are carried out on a wider range of supersymmetric scenarios. This talk focuses on searches looking for signatures of stealth and R-parity-violating supersymmetry.

Speaker: Philip Jason Meltzer (Rutgers State Univ. of New Jersey (US))

15:40 .

14:00 → 16:00 Higgs theory and experiment

Conveners: Johannes Alf Braathen (DESY), Marko Stamenkovic (Brown University (US)), Tania Robens (Rudjer Boskovic Institute (HR)), Tatjana Lenz (University of Bonn (DE))

14:00 Highlights on Higgs measurements with ATLAS

This talk presents recent precision measurements of key properties of the Higgs boson using the full dataset of proton-proton collisions at √s = 13 TeV and 13.6 teV collected during Run 2 and Run 3, respectively, of the LHC by the ATLAS experiment. Recent projections done for the HL-LHC will also be discussed.

Speaker: Maria Mironova (Lawrence Berkeley National Lab. (US))

14:20 .

14:40 .

15:00 Searches for rare Higgs boson processes with the CMS detector

The full set of data collected by CMS experiment at a centre of mass energy of 13 TeV allows searches for rare production modes of the Higgs boson, subdominant with respect the ones already observed at the LHC, by using a variety of decay modes profiting of the ones with largest expected branching fractions. We also discuss rare Higgs boson decay channel searches with the CMS experiment. Searches of decays into quaronia final states can help constrain Yukawa couplings to light and charm quarks. While the expected rate is still limited with the collected data, these modes become enhanced in several BSM theories and can be used to constrain such models. Other rare Higgs boson decay channels, such as H->mumu or H->Zgamma, will also be discussed.

Speaker: Leonardo Giannini (Univ. of California San Diego (US))

15:20 Anomalous couplings and CP properties at CMS

To fully characterize the Higgs boson, it is important to establish whether it presents coupling properties that are not expected in the Standard Model of particle physics. These can probe BSM effects, such as CP conserving or CP violating couplings to particles with masses not directly accessible at the LHC through virtual quantum loops. In this talk we will present the most recent searches from the CMS experiment for anomalous Higgs boson interactions with vector bosons (HVV) or in effective interactions via the gluon-fusion production (ggH). Combination of the results from different channels will be presented, and interpreted as constraints on Wilson coefficients of BSM operators.

Speaker: Rohith Saradhy (University of Minnesota (US))

15:40 .

14:00 → 16:00 Dark matter, Astroparticle, Gravitational waves

Conveners: Gilly Elor, Maria Martinez (Universidad de Zaragoza (ES)), Nicholas Llewellyn Rodd (CERN), Nicholas Rodd (Lawrence Berkeley National Laboratory), Noah Kurinsky (SLAC/Stanford)

14:00 Electric Dipole Moments From Missed Dark Matter Scattering

Axion-like particles are a well-motivated candidate for ultralight dark matter. Because dark matter must be non-relativistic, the effects of its scattering with Standard Model particles are negligible and generally go unnoticed. However, due to the large occupation number of ultralight dark matter, the sum of all scatterings leads to a classical field-like interaction with Standard Model particles. In the case of an axion-like particle, this scattering imparts a parity violating effect. If this collective scattering with axion-like particles is inserted into the one-loop quantum electrodynamics diagram, the parity violation imparted by this scattering will convert the anomalous magnetic moment contribution into an electric dipole moment. This contribution is quite large and leads to a prediction inconsistent with precision measurements of the proton and electron electric dipole moments, unless their couplings to the axion-like particles are very weak. As a result, the constraints on the couplings of axion-like particle dark matter to the electron and proton are improved by as
much as eleven and six orders of magnitude, respectively.

Speaker: Prof. Jason Evans (Shanghai Jiaotong University/TDLI)

14:20 Galactic Axion Laser Interferometer Leveraging Electro-Optics

We introduce GALILEO, a novel experimental approach to detect light dark matter candidates through precision optical interferometry. The method exploits the sensitivity of electro-optical materials, whose refractive indices are modulated by a coherently oscillating dark matter field. Using a highprecision resonant Michelson interferometer as the detection mechanism, GALILEO enables the exploration of uncharted parameter space for light dark matter, including dark photons and axionlike particles, across a broad mass range. Notably, the experiment achieves sensitivity to dark matter masses exceeding tens of microelectronvolts—a challenging regime for conventional microwave cavity haloscopes.

Speaker: Reza Ebadi (University of Maryland, College Park)

14:40 Probing Dark Matter in Red Giants

Red giants (RGs) provide a promising astrophysical environment for capturing dark matter (DM) via elastic scattering with stellar nuclei. Captured DM particles migrate toward the helium-rich core and accumulate into a compact configuration. As the DM population grows, it can become self-gravitating and undergo gravitational collapse, leading to adiabatic contraction through interactions with the ambient medium. The resulting energy release, through elastic scattering and, where relevant, DM annihilation, locally heats the stellar core and can trigger helium ignition earlier than predicted by standard stellar evolution. We analyze the conditions under which DM-induced heating leads to runaway helium burning and identify the critical DM mass required for ignition. Imposing the observational constraint that helium ignition must not occur before the observed luminosity at the tip of the RG branch, we translate these conditions into bounds on DM properties. Remarkably, we find that RGs are sensitive to DM, particularly {\color{red} with masses around $10^{12} \,{\rm GeV}$ and spin-independent scattering cross sections near $10^{-36}\,{\rm cm}^2$}, which lies beyond the reach of current terrestrial direct detection experiments. RG stars, therefore, open a novel observational window for probing heavy DM.

Speaker: Chang Sub SHIN (Chungnam National University)

15:00 On Pulsar Timing Detection of Ultralight Vector Dark Matter

Ultralight vector dark matter induces metric fluctuations that generate timing residuals in the arrival times of pulsar emissions through two distinct modes: a fast mode, sourced by coherent field oscillations, and a slow mode, arising from interference patterns. These modes enable the detection of vector dark matter with masses $m \sim 10^{-24} - 10^{-22}\ \mathrm{eV}$ and $m \sim 10^{-18} - 10^{-16}\ \mathrm{eV}$, respectively, using pulsar timing arrays. While previous studies have explored the fast mode, they neglect the full statistical treatment of the vector field and a precise treatment of its polarization structure. In this work, we investigate the timing residuals from both modes, fully accounting for the statistical properties of ultralight vector dark matter, assuming equipartition among its three polarization states. The two-point correlation functions of timing residuals that we derive serve as direct tools for identifying vector dark matter signatures as a stochastic background in pulsar timing data.

Speaker: Qiushi Wei (University of Florida)

15:20 .

15:40 .

14:00 → 16:00 Non-SUSY extensions of the Standard Model

Conveners: Cristián Peña (Fermi National Accelerator Lab. (US)), Karri Di Petrillo (University of Chicago), Pouya Asadi (University of Oregon), Zhen Liu (University of Minnesota)

14:00 Can forward neutrinos at the LHC help understand cosmic ray showers?

The cosmic ray muon puzzle, an 8$\sigma$ disagreement in the numbers of observed and predicted cosmic ray muons, could be due to a mismodeling of the secondary particle showers in contemporary event generators. A possible solution to the puzzle is provided by the enhanced strangeness hypothesis, suggesting that the showers contain more strange particles than currently predicted. As the incident cosmic ray energies starting at $10^8$ GeV translate to 14 TeV in the center-of-mass frame of proton-proton collisions, the hypothesis can be tested at the existing and proposed forward neutrino detectors at the LHC. The novel LHC neutrino program will hence be able to constrain forward strangeness, potentially solving the muon puzzle. Moreover, we discuss suggested future improvements to the detectors, enhancing these capabilities and providing even further constraints on BSM scenarios affecting hadron production at large rapidities.

Speaker: Dr Toni Makela (University of California, Irvine)

14:20 Distinguishing between Dirac and Majorana HNL's at FASER2

Heavy Neutral Leptons (HNLs) are promising extensions of the Standard Model that could explain neutrino masses, baryogenesis, and dark matter. A key question is whether HNLs are Dirac or Majorana particles, with the latter allowing lepton number violation. We investigate the potential of the proposed FASER2 detector, alone and in combination with ATLAS, to distinguish between Dirac and Majorana HNLs in the GeV mass range. Using simulations with FORESEE and HNLCalc, we assess sensitivity to HNL mass, mixing, and lifetime differences. We find that there are regions of un-probed HNL parameter space where FASER2 alone can discriminate between Dirac and Majorana scenarios based on their energy spectra. Furthermore, we demonstrate that FASER2 can act as a viable trigger for ATLAS within the allowed timing constraints. This coordination enables the use of charge information from prompt leptons observed in ATLAS, which significantly enhances model discrimination when combined with FASER2 data.

Speaker: Alec Hewitt

14:40 Long lived particle searches at FASER

The FASER experiment at the LHC is designed to search for light, weakly-coupled new particles, and to study high-energy neutrinos. The experiment has been running since 2022, and has collected nearly 200/fb of pp collision data. FASER has released a search for long-lived dark photons, and long lived axion-like-particles (also interpreted in several other scenarios). This talk will summarise the long-lived BSM particle search program and discuss future prospects.

Speaker: Eli Marcel Welch (University of California Irvine (US))

15:00 Searches for Dark Matter and new phenomena in hadronic final states with ATLAS

Many theories beyond the Standard Model predict new phenomena giving rise to multijet final states. These jets could originate from the decay of a heavy resonance into SM quarks or gluons, or from more complicated decay chains involving additional resonances that decay e.g. into leptons. Also of interest are resonant and non-resonant hadronic final states with jets originating from a dark sector, giving rise to a diverse phenomenology depending on the interactions between the dark sector and SM particles. This talk presents the latest ATLAS results.

Speaker: Emily Anne Thompson (Lawrence Berkeley National Lab (US))

15:20 .

15:40 .

16:00 → 16:30 Coffee break

16:30 → 18:30 SUSY, strings, field theory

Conveners: Jaroslav Trnka (University of California, Davis), Sungwoo Hong (Korea Advanced Institute of Science & Technology (KAIST))

16:30 Geometric Building Blocks of EFT Amplitudes

The analogy between field redefinitions in EFTs and coordinate transformations suggests that EFT amplitudes can be interpreted as geometric invariants, constructed from fundamental building blocks. We identify these building blocks as geometric quantities derived from the covariant derivatives of the action, which remain covariant in the on-shell limit under derivative-dependent field redefinitions. By restricting to two-derivative theories and applying a field-space-metric-compatible connection, we reproduce the amplitudes being expressed in terms of covariant derivatives of the Riemann curvature tensor and the scalar potential formulated from these building blocks. This geometric perspective provides new insights into the structure of EFT amplitudes and the inherent redundancy associated with general field redefinitions.

Speaker: Xu-Xiang Li (University of Utah)

16:50 UV Origin of Modular Flavor Symmetries

Modular flavor symmetries in supersymmetric models have been proposed as a new way to address the flavor problem. It is known that they can emerge from string compactifications. We discuss this connection in detail, and show how the congruence subgroups of SL(2,Z), which underlie many modular flavor symmetries, emerge from stringy duality symmetries by orbifolding. We show that, at least in the Z3 orbifold, the string selection rules can be understood as discrete remnants of continuous gauge symmetries.

Speaker: Alex Stewart

17:10 Interactions of a Continuous-Spin Field with a Spin-1/2 Particle

We introduce a formalism for coupling bosonic Continuous-Spin Particles (CSP) to familiar spin-1/2 matter. To do this, we describe the matter using the supersymmetric worldline formalism. We construct currents that are local functions of worldline kinematics, and respect both the worldline supersymmetry and the conservation condition required for consistent couplings to Abelian CSP fields. As the spin Casimir $\rho$ of the CSP vanishes, the interactions reduce to that of familiar QED in one case, and to a Yukawa interaction with a spin-1/2 fermion in another case. Our formalism is applicable to computing deviations from QED if the photon is a CSP, thereby enabling a range of phenomenological studies.

Speaker: Shayarneel Kundu

17:30 Domain walls and their junctions from $\mathcal{N}=1$ quarks and gluons

In this talk we are going to discuss multiplicities and junctions of BPS domain walls interpolating between different chiral vacua in $\mathcal{N}=1$ supersymmetric QCD (SQCD) with the $SU(N)$ gauge group and a varying number of fundamental quarks. Depending on the number of flavors $F$ two distinct classes of degenerate domain walls emerge: (i) locally distinguishable, i.e. those which differ from each other locally, in local experiments; and (ii) those which have identical local structure and are differentiated only topologically, through judicially chosen compactifications. In the first class two-wall junctions exist while in the second class such junctions do not exist. Acharya and Vafa counted topologically distinguishable walls in pure super-Yang-Mills. Ritz, Shifman and Vainshtein counted the locally distinguishable walls in $F=N$ SQCD. In both cases the multiplicity was the same.

We study the general case $0 \leqslant F \leqslant N$, with mixed sets of walls from both classes (i) and (ii) simultaneously, and demonstrate that the above overall multiplicity remains intact. We argue that the growth of the quark mass $m$ does not exhibit a phase transition at any finite masses. The locally distinguishable walls can turn into topologically distinguishable only at $m=\infty$. An evolution of the low-energy wall world sheet theory in passage from small to large $m$ is briefly discussed. We also propose a candidate for the low-energy description of wall junctions.

Speaker: Evgenii Ievlev (University of Minnesota)

17:50 No gauge cancellation at high energy in the five-vector $R_\xi$ gauge

We propose a novel $R_\xi$ gauge in the five-vector (5V) framework within the Abelian Higgs model. In the Cartesian basis of the complex Higgs field, the 5V $R_\xi$ gauge ensures non-divergent tree-level amplitudes for each Feynman diagram in the high-energy limit. This framework pinpoints the origin of high-energy divergences in tree-level amplitudes for each diagram, providing a criterion for quantifying the degree of divergences from other gauges. The 5V description necessitates treating the Goldstone field as the fifth gauge-field component, offering deeper insight into the dynamics of massive gauge bosons, particularly its longitudinal mode. The impact of this framework is demonstrated by rigorously comparing tree-level amplitudes from the 5V $R_\xi$ gauge with those from the conventional 4V $R_\xi$ gauge and the Feynman diagram gauge, the latter of which exhibits no gauge cancellation, similar to the 5V $R_\xi$ gauge.

Speaker: Jaehoon Jeong (KIAS)

18:10 .

16:30 → 18:30 Higgs theory and experiment

Conveners: Johannes Braathen (DESY), Marko Stamenkovic (Brown University (US)), Tania Robens (Rudjer Boskovic Institute (HR)), Tatjana Lenz (University of Bonn (DE))

16:30 Maximal Entanglement and Symmetries in the 2HDMs

We consider 2-to-2 scatterings of Higgs bosons in a CP-conserving two-Higgs-doublet model (2HDM) and study the implication of maximizing the entanglement in the flavor space. In the unbroken phase and turning off the gauge interactions, entanglement maximization results in the appearance of an U(2) x U(2) global symmetry. Interestingly, once the Higgs bosons acquire vacuum expectation values, maximal entanglement enforces an exact U(2)xU(2) symmetry, which is spontaneously broken to U(1) x U (1). As a byproduct, this gives rise to Higgs alignment as well as to the existence of 6 massless Nambu-Goldstone bosons. The U(2)xU(2) symmetry can be gauged to lift the massless Goldstones, while maintaining maximal entanglement demands the presence of a discrete Z2 symmetry interchanging the two gauge sectors. The model is custodially invariant in the scalar sector, and the inclusion of fermions requires a mirror dark sector, related to the standard one by the Z2 symmetry.

Speaker: Prof. Carlos Wagner (University of Chicago)

16:50 .

17:10 Machine Learning to rescue large pseudoscalar Yukawa couplings in the C3HDM

With LHC Run 3 in progress, the 125GeV Higgs boson couplings are being examined in greater detail, while testing for additional scalars. Multi-Higgs frameworks allow Higgs couplings to significantly deviate from Standard Model values, enabling indirect probes of extra scalars. We consider the possibility of large pseudoscalar Yukawa couplings in the softly-broken three-Higgs doublet model with CP violating coefficients. We present a parameterization of the rotations leading to the mass eigenstates and describe all the current constraints. To explore the parameter space of the model, we employ a Machine Learning algorithm that significantly enhances sampling efficiency. This method leverages an Evolutionary Strategy to improve convergence towards valid regions with an additional Novelty Reward mechanism. We show the potential of the new techniques, applicable to any beyond the Standard Model scenario.

Speaker: Rafael Filipe Teixeira Boto (Instituto Superior Técnico)

17:30 .

17:50 .

18:10 .

16:30 → 18:30 Dark matter, Astroparticle, Gravitational waves

Conveners: Gilly Elor, Maria Martinez, Nicholas Llewellyn Rodd (CERN), Nicholas Rodd, Noah Kurinsky (SLAC/Stanford)

16:30 Gravothermal evolution of self-interacting dark matter halos beyond the born regime

Self-interacting dark matter (SIDM) provides an intriguing alternative to collisionless dark matter, especially when it comes to resolving small-scale structure problems. I will present our preliminary findings on gravothermal collapse in SIDM halos using an extended version of the GravothermalSIDM code, now capable of incorporating velocity-dependent cross sections from the CLASSICS repository and going beyond the Born limit for the Yukawa potential. This framework allows us to systematically explore a wide range of velocity dependencies and help us understand how these dependencies impact the onset and progression of gravothermal collapse. In this talk, I will discuss how we can probe a much broader range in parameter space by including non-perturbative effects and the potential to establish new limits based on halo collapse timescales.

Speaker: Bashi Mandava (UC Berkeley)

16:50 Ultra-faint dwarf galaxies are more concentrated than expected

Dark matter dominated dwarf galaxies are considered excellent targets for probing particle dark matter and galaxy formation. However, current estimates of dark matter density profiles for these systems may be prone to systematic uncertainties. In this talk, I will discuss a new method for inferring dwarf galaxy characteristics from semi-analytic modeling and explore the associated systematics. In particular, we find that ultra-faint dwarf galaxies are systematically more concentrated than expectations under the standard cosmological model. I will also discuss astrophysical J-factor estimation for both dwarf galaxies and the recently discovered Ursa Major III system. Finally, we apply our inferred J-factors to the analysis of gamma-ray data from Fermi LAT telescope and present adjusted constraints on WIMP dark matter annihilation cross section.

Speaker: Kailash Raman (University of California, Berkeley)

17:10 Strong Gravitational Lensing for Inference of Small-Scale Dark Matter Structure

Strong gravitational lenses are a singular probe of the Universe's small-scale structure—they are sensitive to the gravitational effects of low-mass ($<10^{10} M_\odot$) halos even without a luminous counterpart. Constraining structure at these scales opens a window into the phenomenological properties of dark matter, allowing us to constrain self-interacting, warm, and fuzzy dark matter models. Accessing this rich trove of information requires an array of advancements in our statistical modeling techniques. In this talk, I’ll present two of these advances. The first, sequential simulation-based inference, leverages our access to a reliable simulator to iteratively focus computational effort on the regions of parameter space preferred by the data. The second, diffusion model priors for source separation, allows us to build expressive, data-driven priors directly from noisy, incomplete observations. As a demonstration of these methods, I will present initial constraints on the small-scale structure population using a set of Hubble Space Telescope lenses.

Speaker: Dr Sebastian Wagner-Carena (Flatiron / NYU)

17:30 Learning the energy dependence and source brightness distribution of the Galactic Center Excess

An excess of gamma rays from the Galactic center is observed by the Fermi Space Telescope. The two leading hypotheses for the cause of this excess are millisecond pulsars or dark matter. Generically, we expect the statistics of these two sources to differ. We train a graph convolutional neural network (NN) to accurately determine the relative flux contribution of point sources to the Galactic center excess (GCE), training the model on the energy dependent data for the first time. The NN method allows us to avoid biases that have been attributed to existing likelihood based techniques and we show training on energy dependent data predicts sources that are indistinguishable from Poisson emission. We determine that we cannot rule out any of the flux of the GCE as Poisson-like and we need at least order O(10,000) sources to explain the observed excess.

Speaker: Eve Schoen (UC Berkeley)

17:50 Dark plasmas in the nonlinear regime: Constraints from particle-in-cell simulations

If the dark sector possesses long-range self-interactions, these interactions can source dramatic collective instabilities even in astrophysical settings where the collisional mean free path is long. Here, we focus on the specific case of dark matter halos composed of a dark $𝑈⁡(1)$ gauge sector undergoing a dissociative cluster merger. We study this by performing the first dedicated particle-in-cell plasma simulations of interacting dark matter streams, tracking the growth, formation, and saturation of instabilities through both the linear and nonlinear regimes. We find that these instabilities give rise to local (dark) electromagnetic inhomogeneities that serve as scattering sites, inducing an effective dynamic collisional cross section. Mapping this effective cross section onto existing results from large-scale simulations of the Bullet Cluster, we extend the limit on the dark charge-to-mass ratio by over 10 orders of magnitude. Our results serve as a simple example of the rich phenomenology that may arise in a dark sector with long-range interactions and motivate future dedicated study of such “dark plasmas.”

Speaker: Pierce Giffin

18:10 Indirect Searches for Ultraheavy Dark Matter in the Time Domain

Dark matter may exist today in the form of macroscopic composite bound states. Collisions between such dark matter states can release intense bursts of radiation that includes gamma-rays among the final products. Thus, indirect-detection signals of dark matter may include unconventional gamma-ray bursts. Such bursts may have been missed not necessarily because of their low arriving gamma-ray fluxes, but rather their briefness and rareness. We point out that intense bursts whose non-detection thus far are due to the latter can be detected in the near future with existing and planned facilities. In particular, we propose that, with slight experimental adjustments and suitable data analyses, imaging atmospheric Cherenkov telescopes (IACTs) and Pulsed All-sky Near-infrared and Optical Search for Extra-Terrestrial Intelligence (PANOSETI) are promising tools for detecting such rare, brief, but intense bursts. We also show that if we assume these bursts originate from collisions of dark matter states, IACTs and PANOSETI can probe a large dark matter parameter space beyond existing limits. Additionally, we present a concrete model of dark matter that produces bursts potentially detectable in these instruments.

Speaker: Erwin Tanin (Stanford)

16:30 → 18:30 Non-SUSY extensions of the Standard Model

Conveners: Cristián Peña (Fermi National Accelerator Lab. (US)), Karri Di Petrillo (University of Chicago), Pouya Asadi (University of Oregon), Zhen Liu

16:30 Heavy Twin Higgs Axion

Heavy axions address the strong CP problem in a robust way, less susceptible to high scale corrections to their potential. We outline a framework for producing a GeV scale axion while simultaneously addressing the other naturalness issue of the Standard Model: the electroweak hierarchy problem. This is done by modifying the twin Higgs framework so that the twin sector has a larger color group while preserving its natural aspects. We also comment on the experimental signatures that can be used to probe this construction.

Speaker: Christopher Verhaaren (Brigham Young University)

16:50 A covariant description of the interactions of axion-like particles and hadrons

Axion-like particles (ALPs) can couple to both gluons and quarks, leading to rich hadronic phenomenology. In this talk, I present a field-redefinition–invariant framework that captures these interactions in a unified way. By identifying invariant combinations of ALP couplings, we derive physical decay rates using a data-driven method to interpolate between chiral perturbation theory and perturbative QCD prediction. This provides a robust, model-independent toolkit for calculating ALP production and decay rates across a wide ALP mass range.

Speaker: Reuven Balkin (UC Santa Cruz)

17:10 Probing the CP properties of ALP couplings using 3-body neutral kaon decays

Flavor probes, in particular rare kaon decays, provide some of the strongest constraints on ALP couplings. Rare neutral kaon decays also provide a unique probe to the CP properties of ALP couplings. In this talk I will present a first calculation of the 3-body neutral kaon decay rates, first by showing how the required flavor- and CP-violating couplings are generated from the UV theory. I will discuss the symmetry properties of the amplitudes and compare the rates from 2- and 3-body neutral kaon decays for a few benchmark cases. Finally, I will present some of the phenomenological implications.

Speaker: Reuven Balkin (UC Santa Cruz)

17:30 Cheshire θ terms, Aharonov-Bohm effects, and axions

We discuss unusual θ terms that can appear in field theories that allow global vortices. These "Cheshire θ terms" induce Aharonov-Bohm effects for some particles that move around vortices. For example, a Cheshire θ term can appear in QCD coupled to an axion and induces Aharonov-Bohm effects for baryons and leptons moving around axion strings. We point out a potential experimental signature left on the spectrum of gravitational waves from axion cosmic string network by the Cheshire θ term.

Speaker: Gongjun Choi

17:50 Non-abelian Embeddings of the Standard Model Group and Charge Quantisation

In this talk, I will show a novel minimal non-abelian gauge group to embed the G_{SM}/Z1 quotient with fractionally charged beyond the standard model matter fields and show how we can define a new quantum number n_6 that is written in terms of the generators of G_{SM}. We also comment on interesting aspects of this new number, like how the degree of compositeness can shift n_6. This new quantum number we suggest can give a full spectrum of allowed electric and magnetic charges and has an important connection to the topology of the standard model gauge group.

Speaker: Yunji Ha (Institute of Particle Physics Phenomenology)

18:10 .

19:00 → 21:00 Conference Banquet

Friday 22 August

08:30 → 09:00 Registration

09:00 → 10:30 Plenary 11

09:00 Overview of Cosmology

Speaker: Prof. Francis-Yan Cyr-Racine (University of New Mexico)

09:30 Baryogenesis

Speaker: Marcela Carena Lopez

10:00 Gravitational Waves and Phase Transitions

Speaker: Sebastian Ellis (Universite de Geneve (CH))

10:30 → 11:00 Coffee break

11:00 → 12:30 Plenary 12

11:00 Axion Theory

Speakers: Kiwoon Choi (KAIST), Kiwoon Choi (KAIST), Kiwoon Choi, Kiwoon Choi (IBS CTPU)

11:30 Overview of Axion/Light Boson Searches

Speakers: Chelsea Bartram, Chelsea Bartram (SLAC)

12:00 Novel Probes of Axions

Speaker: Masha Baryakhtar (University of Washington)

12:30 → 14:00 Lunch break

14:00 → 16:00 SUSY, strings, field theory

Conveners: Jaroslav Trnka (University of California, Davis), Sungwoo Hong (Korea Advanced Institute of Science & Technology (KAIST))

14:00 Higher-Dimensional Fermionic SYK Model in IR Region

We study the 2D fermionic SYK model with Majorana fermions, featuring a kinetic term with a quartic expression and a $2q$-body interaction with Gaussian disorder. By minimizing the effective action or solving the SD equation for $q=1$, we determine that the appropriate ansatz involves zero spins. Our computation of the Lyapunov exponent shows violations of chaos and unitarity bounds. The gravitational dual corresponds to AdS$_3$ Einstein gravity with a finite radial cut-off even if we lose the non-zero spins. We also extend the SYK model to higher dimensions while maintaining a similar SD equation in the IR.

Speaker: Chen-Te Ma

14:20 Understanding Strongly Coupled Theories with AMSB

I will review developments in applying Anomaly Mediated SUSY Breaking (AMSB) as a theoretical tool for understanding the dynamics of strongly coupled gauge theories. After reviewing the general properties of AMSB, I will show what we have been able to learn when applying it to a variety of examples. Many non-trivial consistency conditions are satisfied. In the case of QCD, I will show how we can establish the presence of chiral symmetry breaking vacua, explicitly calculate condensates, derive the chiral lagrangian, and even obtain the low-lying spectrum of hadrons in qualitative agreement with QCD. I will conclude with an example of a phenomenological application in composite axion models.

Speaker: Bea Noether (UC Berkeley)

14:40 Exact Results in Chiral Gauge Theories with Flavor

We present exact results in SU($N_C$) chiral gauge theories with charged fermions in an antisymmetric, $N_F$ fundamental, and $N_C + N_F − 4$ anti-fundamental representations. We achieve this by considering the supersymmetric version of these theories and utilizing anomaly mediated supersymmetry breaking at a scale $m ≪ Λ$ to generate a vacuum. The connection to non-supersymmetric theories is then argued by taking the limit $m → ∞$. For odd $N_C$, we determine the massless fermions and unbroken global symmetries in the infrared. For even $N_C$, we find global symmetries are non-anomalous and no massless fermions. In all cases, the symmetry breaking patterns differ from what the tumbling hypothesis would suggest.

Speaker: Bethany Suter (UC Berkeley)

15:00 Holographic Chiral Anomalies

The structure of chiral anomalies in braneworlds is subtle. The divergence of a 5D current has long been known to be localized to end-of-the world branes, and to be evenly divided between these branes. However, such branes may be hidden by horizons, or may even be replaced by soft-wall geometries in certain cases. We demonstrate the correct approach, particularly in models motivated by the AdS/CFT correspondence, is to flow the anomaly with appropriate Chern-Simons terms so that only the UV, or "cut-off" brane contains the anomaly.

Speaker: Prakriti Singh (Syracuse University)

15:20 Phenomenology of Holographic Chiral Anomalies

In Randall-Sundrum models, the AdS/CFT correspondence motivates the addition of Chern-Simons terms that flow anomalies such that they are entirely localized on the ultraviolet brane. This has interesting implications both for collider physics and for cosmology. We discuss the implications for holographic composite axion solutions to the strong CP problem, and for inflationary cosmology.

Speaker: Hanieh Moradipasha

15:40 .

14:00 → 16:00 Higgs theory and experiment

Conveners: Johannes Braathen (DESY), Marko Stamenkovic (Brown University (US)), Tania Robens (Rudjer Boskovic Institute (HR)), Tatjana Lenz (University of Bonn (DE))

14:00 Prospects for light exotic scalar measurements at the e+e- Higgs factory

Extra light scalars are still not excluded by the existing experimental constraints, provided their coupling to the SM gauge bosons is sufficiently suppressed. They could be produced at the e$^+$e$^-$ Higgs factory in a scalar-strahlug process, analogous to the Higgs-strahlung process being the dominant production channel for the 125 GeV Higgs boson. This was selected as one of the focus topics of the ECFA Higgs/Top/EW factory study and various search strategies were considered. Presented are the expected cross section limits from the decay-mode independent search and from the search in the $b\bar{b}$ decay channel, based on a full simulation of the International Large Detector (ILD), supplemented with the expected sensitivity in di-tau and invisible decay channels, based on the fast simulation in the DELPHES framework, assuming 250 GeV ILC running scenario.

Speaker: Aleksander Zarnecki (University of Warsaw (PL))

14:20 Di-Higgs Production in the 2HDM at high-energy $e^+e^-$ Colliders

Within the framework of the 2HDM we discuss di-$h_{125}$ production at future high-energy $e^+e^-$ colliders, such as ILC or CLIC. We analyze the sensitivity to BSM triple Higgs couplings (THCs), taking into account experimental errors and uncertainties. Our results indicate that BSM THCs can possibly accessed at ILC or CLIC.

Speaker: Milada Margarete Mühlleitner

14:40 The Price of a Large Electron Yukawa

The electron Yukawa coupling is expected to be the last Standard Model coupling to be measured, requiring the next generation of colliders. In the coming decades, the FCC will offer a constraint on the Higgs-electron coupling that is within a factor of a few with the Standard Model value. If a discovery of this coupling is made at the FCC, it would be a clear sign of new physics. However, models which modify the electron Yukawa to this extent can induce deviations in other observables. In this talk, I will review the alternative observables that are connected to the electron Yukawa and evaluate feasibility of discovering an enhanced electron Yukawa at the FCC.

Speaker: Duncan Rocha (University of Chicago)

15:00 Higgs Boson Production at µ+ µ+ Colliders

Motivated by recent advancements in antimuon cooling, we study Higgs boson production at $\mu^+\mu^+$ colliders at high energy. Since both initial-state particles are positively charged, there is no $W$ boson fusion at the leading order, as it requires a $W^+W^−$ pair. However, we find that the cross section of the higher-order, $\gamma$- and $Z$-mediated $W$ boson fusion process is large at high center-of-mass energies $\sqrt{s}$, growing as $(\log s)^3$. This is in contrast to the $(\log s)$ behavior of the leading-order $W$ boson fusion. Thus, even though it is a higher-order process, the rate of Higgs boson production for 10 TeV energies at $\mu^+\mu^+$ colliders with polarized beams can be as high as about half of the one at $\mu^+\mu^−$ colliders, assuming the same integrated luminosity. To calculate the cross section of this process accurately, we carefully treat the collinear emission of the photon in the intermediate state. The thereby obtained large cross section furthermore shows the significance of Higgs boson production with an extra $W$ boson in the final state also at $\mu^+\mu^−$ and $e^+e^−$ colliders.

Speaker: Lukas Treuer (Yukawa Inst., Kyoto U. and KEK, SOKENDAI (Japan))

15:20 BSM Triple Higgs Couplings at a Future Muon Collider

We analyze di-Higgs production at a future $\mu^+\mu^-$ collider. As a concrete framework we take the SM extended by a real Singlet (RxSM), the simplest Higgs-sector extension that can yield a Strong First Order Electroweak Phase Transition (SFOEWPT) in the early universe. Concentrating on the parameter space yielding a SFOEWPT we demonstrate that with the measurement of different di-Higgs production modes all four triple Higgs couplings of the model can be reconstructed.

Speaker: Sven Heinemeyer (CSIC (Madrid, ES))

15:40 .

14:00 → 16:00 Dark matter, Astroparticle, Gravitational waves

Conveners: Gilly Elor, Maria Martinez (Universidad de Zaragoza (ES)), Nicholas Llewellyn Rodd (CERN), Nicholas Rodd (Lawrence Berkeley National Laboratory), Noah Kurinsky (SLAC/Stanford)

14:00 The Axion Dark Matter Experiment (ADMX)

QCD axions are the resulting bosons from the Peccei-Quinn mechanism which solves the strong CP problem, and are also a convincing candidate for wavelike dark matter. The Axion Dark Matter Experiment (ADMX) is an axion haloscope located at the University of Washington which directly detects axions through axion-photon coupling. Since the axion mass and corresponding conversion photon frequency is unknown, an axion haloscope will need to scan across a wide range of frequencies at relevant sensitivities such as the benchmark models Kim-Shifman-Vainshtein-Zakharov (KSVZ) and Dine-Fischler-Srednicki-Zhitnitskii (DFSZ). In order to achieve this, ADMX uses a superconducting solenoid magnet to convert axions into photons inside a resonant microwave cavity which is read out through a receiver chain with low noise, nearly-quantum-limited-amplifiers as the first amplifier. ADMX has so far excluded KSVZ axions for 1.93 - 4.2 µeV and DFSZ axions for 2.66 - 3.3 µeV and 3.9 - 4.1 µeV at a 90% confidence level. In this talk, I will present the current status and future plans of ADMX as well as additional R&D efforts to expand our reach into the wider axion parameter space.

Speaker: Andrew Yi

14:20 Bode-Fano Evasion for Broadband Axion Searches

The QCD axion is a well-motivated dark matter candidate that also solves the strong CP problem. Axion detection often relies on axion-to-photon conversion in a strong magnetic field, inducing a monochromatic AC signal whose frequency depends on the unknown axion mass and may span over ten orders of magnitude. The most sensitive searches—scanning resonant experiments—use high-Q resonators to enhance this signal while tuning across the frequency parameter space. However, the sensitivity and scan rate of these searches is fundamentally limited by the Bode-Fano constraint, which enforces a tradeoff between bandwidth and gain for any passive, linear, time-invariant system. In this talk, we present a conceptual design and preliminary simulations of a “Bode-Fano evading” device that uses Josephson junctions to break passivity and linearity assumptions. We will focus on the theoretical overview, simulation, and characterization of such devices, with special emphasis on their implication for the sensitivity of GUT-scale axion searches.

Speaker: Pamela Stark

14:40 High Frequency Axion Detectors from ADMX-VERA

Axions are theoretical particles which explain why the strong force does not violate CP symmetry, and can be created in the early universe in enough abundance to account for all of dark matter, making them a very compelling dark matter candidate. The axion couples feebly to magnetic fields, converting to a photon; using resonant cavities in the presence of a strong magnetic field we can detect these photons. However, the allowed mass range for the axion is enormous, spanning ~10 orders of magnitude, with corresponding range in the photon’s frequency. For this reason we need devices that can scan over a wide range of frequencies. ADMX-VERA is developing high frequency cavities to further probe the axion parameter space, including the wedge cavity and beehive cavity. These cavities come with new challenges, including the localization of the cavity modes. To address this, we are developing and currently testing a device for coupling to multiple locations in the cavity at once.

Speaker: Jacob Laurel (Stanford, SLAC)

15:00 Prospects and constraints for sub-GeV DM with spin-dependent interactions to nucleons

In recent years attention has shifted to probes of sub-GeV dark matter. In this work, we explore the direct detection prospects through single/multiphonon production for dark matter in the keV-GeV mass range, which couples effectively to protons/neutrons via spin-dependent interactions. In particular, we consider coupling the SM to the dark matter through a pseudo scalar, scalar or pseudo vector mediators in the UV, and we derive the expected cross-sections that could be accessible to GaAs and sapphire. We find that our results are complementary to the bounds obtained from meson decays and from astrophysical constraints such as supernova SN1987A and dark matter self-interactions. In particular, for $m_\chi \gtrsim 100$ MeV, previously unexplored parameter space may be probed by these crystals assuming a minimal detectable signal rate of roughly a hundred events/g-yr.

Speaker: Pankaj Munbodh (University of California Santa Cruz)

15:20 Towards the deployment of DAMIC-M

The DAMIC-M (DArk Matter In CCDs at Modane) experiment is scheduled to begin operations at the Modane underground laboratory (LSM) in late 2025. This talk presents the current status of the project, highlighting recent results from its prototype—the Low-Background Chamber (LBC)—and progress on detector construction at LSM. Data from the LBC have been used to exclude theoretical benchmarks where hidden-sector particles make up the dominant component of dark matter via freeze-in or freeze-out mechanisms. In preparation for DAMIC-M, 26 CCD modules packaged at the University of Washington will undergo underground testing at LSM for detailed characterization prior to their integration into the full detector array.

Speaker: Dr Nuria Castello-Mor (Universidad de Cantabria, CSIC, Instituto de Fisica de Cantabria IFCA, (ES))

15:40 Progress of the TESSERACT Dark Matter Experiment

The TESSERACT project will use a slate of target materials optimized for MeV to few-GeV mass dark matter searches alongside transition-edge-sensors to set world-leading limits on the dark matter/nucleon cross-section. After a brief overview of the experimental goals and sensor technologies, I will discuss the status of the superfluid He-4 target, (HeRALD,) for which multi-channel readout has been demonstrated in two testbeds. Next, I will discuss the ongoing testing of sapphire and gallium arsenide targets (SPICE). Finally, I will briefly discuss additional targets and the outlook for TESSERACT as we move underground for an extended science run in Modane, France in 2028.

Speaker: William Matava (UC Berkeley)

14:00 → 16:00 Non-SUSY extensions of the Standard Model

Conveners: Cristián Peña (Fermi National Accelerator Lab. (US)), Karri Di Petrillo (University of Chicago), Pouya Asadi (University of Oregon), Zhen Liu

14:00 Electroweak spin-1 resonances in Composite Higgs models

Composite Higgs models offer an elegant solution to the hierarchy problem by assuming that the Higgs boson is not an elementary particle but a composite state. The Higgs emerges as a pseudo-Nambu-Goldstone boson due to spontaneous symmetry breaking within a new strongly interacting sector.
We focus on minimal realizations of such models with fermionic UV completions that preserve custodial symmetry and naturally include fermionic resonances acting as top partners.
These models predict spin-1 resonances which carry electroweak quantum numbers.
We find that three such states mix significantly with the electroweak gauge bosons, allowing their single production in Drell-Yan-like processes at the LHC. We explore the rich LHC phenomenology of these states and find scenarios where their masses could be as low as 1.5 TeV.

Speaker: Jan Hadlik (University Würzburg)

14:20 Searches for New Resonances in CMS

The quest for new physics is a major aspect of the CMS experimental program. This includes a myriad of theoretical models involving resonances that can decay to massive bosons, photons, leptons or jets. This talk presents an overview of such analyses with an emphasis on new results and the novel techniques developed by the CMS collaboration to boost the search sensitivity. The searches are carried out with data of the Run-II and Run-III of the LHC in proton-proton collisions with the CMS detector, including those data with dedicated data-streams.

Speaker: Emery Nibigira (University of Tennessee (US))

14:40 CP-violation in the complex singlet extension of 2HDM

We explore the possibility of CP-violation in the complex-singlet extension of 2HDM. The addition of complex singlet paves the way for additional sources of CP-violation compared to 2HDM. If a Z2-symmetry is imposed on the complex-singlet, such a model can accommodate a dark matter candidate as well. We identify the regions of parameter space, that can fit DM observables and at the same time generate sufficient CP-violation. The amount of CP-violation gets severely constrained from electric-dipole moment (EDM) experiments, which we take into account. In addition, we examine the impact of other theoretical and experimental constraints. Finally, we probe the CP-violation in this model at present and future collider experiments.

Speaker: Dr Jayita Lahiri (University of Hamburg)

15:00 Quark-universal U(1) breaking scalar at the LHC

If the quarks or leptons are charged under a new $U(1)$ gauge
symmetry, then besides a $Z'$ boson there must exist at least one new
boson whose decay products include Standard Model particles. In the
case of a minimal symmetry breaking sector, that new boson is a scalar
$\phi$ that couples to the $Z'$ boson as well as to the new
fermions required to cancel the $U(1)$ gauge anomalies. The scalar
may be produced at the Large Hadron Collider (LHC) in association with a $Z'$ boson, or
through $Z'$ boson fusion, while its decays are typically into four
jets or two photons. We analyze in detail the case where the $Z'$
boson is leptophobic, and all the quarks have the same charge under
the new $U(1)$. If $\phi$ mixes with the Standard Model Higgs
boson, then the new scalar can also be produced via gluon fusion, and the
discovery mode is likely to be a diphoton resonance.

Speaker: Lorin Armbruster

15:20 Searches for new phenomena in final states with 3rd generation quarks using the ATLAS detector

Many theories beyond the Standard Model predict new phenomena, such as heavy vectors or scalar, vector-like quarks, and leptoquarks in final states containing bottom or top quarks. Such final states offer great potential to reduce the Standard Model background, although with significant challenges in reconstructing and identifying the decay products and modelling the remaining background. The recent 13 TeV pp results, along with the associated improvements in identification techniques, will be reported.

Speaker: Makayla Vessella 🐏 (University of California Irvine (US))

15:40 .

16:00 → 16:30 Coffee break

16:30 → 18:30 Supersymmetry phenomenology and experiment

Conveners: Isabell Melzer-Pellmann (Deutsches Elektronen-Synchrotron (DE)), Jason Evans (Shanghai Jiaotong University/TDLI), Jeff Shahinian (University of Pennsylvania (US)), Krzysztof Rolbiecki (University of Warsaw)

16:30 Search for supersymmetry with compressed spectra with ATLAS

Supersymmetry (SUSY) models with featuring small mass splittings between one or more particles and the lightest neutralino could solve the hierarchy problem as well as offer a suitable dark matter candidate consistent with the observed thermal-relic dark matter density. However, the detection of SUSY higgsinos at the LHC remains challenging especially if their mass-splitting is O(1 GeV) or lower. Searches are developed using the LHC ATLAS Run 2 dataset to overcome the challenge. Novel techniques are developed exploiting machine-learning techniques, low-momentum tracks with large transverse impact parameters, or topologies consistent with VBF production of the supersymmetric particles. Results are interpreted in terms of SUSY simplified models and, for the first time since the LEP era, several gaps in different ranges of mass-splittings are excluded.

Speaker: Sonia Carra (Pavia University and INFN (IT))

16:50 Searching for Supersymmetry at FCC-ee

We discuss indirect probes of the MSSM at FCC-ee, with particular emphasis on the complementarity between single Higgs production and electroweak precision tests at the Tera-Z run. In addition to flavor-universal contributions to the STWY oblique parameters, we point out important flavor non-universal effects. An example of the latter is the heavy Higgs doublet, which gives tree-level shifts in Higgs couplings as well as sizeable RGE contributions to the Zbb vertex. Overall, we find that FCC-ee can probe the MSSM in the multi-TeV range, and test the naturalness of the EW scale at the per-mille level.

Speaker: Benjamin Stefanek (IFIC Valencia)

17:10 Anomaly-Mediated SUSY Breaking in QCD-like SU(N) and Sp(N) Gauge Theories

We present an analytical derivation of the chiral symmetry breaking minima in supersymmetric asymptotically-free SU(N) and Sp(N) theories with F flavors of "quarks", perturbed by Anomaly Mediated Supersymmetry Breaking. We are able to show that all such theories, except in the SU(N) case of N = F, possess stable chiral symmetry breaking minima that are plausibly continuously connected to the vacua of QCD-like SU(N) or Sp(N) theories for large SUSY breaking.
In SU(N) QCD, due to the presence of incalculable global minima, we are often able to only derive "locally stable" chiral symmetry breaking minima. In particular, tachyonic two-loop AMSB masses lead to baryonic runaways to incalculable minima at the upper end of the free magnetic phase (1.5N ≥ F ≳ 1.43N), whereas for the s-confining case (F = N + 1) and most of the free-magnetic phase (F ≤ 1.43N) we find that naive tree-level baryonic runaways are stabilized by loop effects near the origin of moduli space. However, in the Sp(N) counterparts, all the minima that we derive are global because tachyonic dual squark directions are naturally stabilized by quartic tree level SUSY potentials, and there are no tree level runaways as baryons are absent.

Speaker: Digvijay Roy Varier (University of California, Berkeley)

17:30 The EDM inverse problem: Disentangling the sources of CP violation and PQ breaking with EDMs

The permanent electric dipole moments (EDMs) of nucleons, atoms, and electrons serve as powerful probes of new physics beyond the TeV scale. Once a non-vanishing EDM is discovered, an important issue may be identification of the underlying CP violating source originated from high energy physics. In this work, we investigate the feasibility of experimentally identifying the ultraviolet (UV) origin of CP violation through future EDM measurements. In particular, we explore whether future EDM data can reveal the UV origin of the QCD axion vacuum expectation value. We find that CP violation dominated by the gluon chromo-electric dipole moment (CEDM) or by quark CEDMs—with or without the QCD axion—can be experimentally distinguished from CP violation dominated by the Standard Model (SM) QCD theta term, based on distinctive nuclear and atomic EDM patterns. Generally, future EDM experiments, together with improved theoretical calculations, may enable us to disentangle (semi-)leptonic and four other hadronic UV CP-violating sources from the SM CP violation dominated by the QCD theta term.

Speaker: Dr Sang Hui Im (IBS CTPU)

17:50 .

18:10 .

16:30 → 18:30 Cosmology and the early Universe: Joint Dark Matter / Cosmology

Conveners: Elisabeth Krause (The University of Arizona), Gilly Elor, Kai Schmitz (Westfaelische Wilhelms-Universitaet Muenster (DE)), Kimberly Boddy (University of Texas at Austin), Maria Martinez, Nicholas Llewellyn Rodd (CERN), Nicholas Rodd, Noah Kurinsky (SLAC/Stanford)

16:30 Primordial Gravitational Waves from Phase Transitions during Reheating

We study primordial gravitational waves (GWs) generated from first-order phase transitions (PTs) during cosmic reheating. Using a minimal particle physics model, and a general parametrization of the inflaton energy density and the evolution of the Standard Model temperature, we explore the conditions under which PTs occur and determine the corresponding PT parameters (the PT temperature, duration and strength), which depend on the evolution of the background during reheating. We find that, in certain cosmological scenarios, PTs can be delayed and prolonged compared to the standard post-inflationary evolution. Incorporating these PT parameters, we compute the resulting GW spectrum generated from the various processes occurring during a first-order PT: bubble collisions, sound waves, and magneto-hydrodynamic turbulence. We find that, in comparison to the standard cosmological history, the GW amplitude and peak frequency can be modified by several orders of magnitude due to the additional enhancement or suppression arising from the cosmological evolution during reheating. In particular, the GW spectra could be within the reach of next-generation GW and CMB observatories.

Speaker: Amitayus Banik (Chungbuk National University)

16:50 Gravitational Wave Signals from Spectator Scalar Fields

In this talk, I will present a novel mechanism for gravitational wave generation from spectator scalar fields in the early universe. Spectator scalar fields with masses below the inflationary scale can produce significant isocurvature power spectra in the ultraviolet region, generating substantial curvature perturbations at small scales. These perturbations result in a stochastic gravitational wave background (SGWB) with typical amplitudes of Ω_GW h^2 = 10^{-18} – 10^{-6} across frequencies ranging from 10^{-18} to 1 Hz. Notably, these signals fall within detection ranges of planned gravitational wave observatories. I will demonstrate that these gravitational waves impose new, more stringent constraints on spectator field masses than those derived from isocurvature perturbations alone. Finally, I will explore enhancement mechanisms for the isocurvature power spectrum through direct coupling between the inflaton and spectator fields, highlighting how such interactions modify the resulting gravitational wave signatures.

Speaker: Sarunas Verner (University of Florida)

17:10 Constraining Dark Matter from Gravitational Wave Observations

In this talk, I will explore how gravitational-wave(GW) observations of compact binary mergers can provide insight into properties of dark matter through examples of specific models which predict the formation of compact objects detectable by current and future GW detectors. GW signals from black hole binaries that form from the cooling and gravitational collapse of dissipative dark matter halos constrain the mass spectrum of such objects. On the other hand, asymmetric dark matter accumulation in the cores of neutron stars can cause their implosion to form solar-mass black holes which, if present in binary systems, will produce detectable GW signals. Especially, the detection of a sub-solar mass black hole will provide decisive evidence for new physics, and possibly formation channels involving dark matter. Searches for GW signals from sub-solar mass compact objects have been conducted in data from LIGO-Virgo detectors with no detections so far. However, they constrain the merger rates of such binaries which in turn provide useful constraints for dark matter candidates like primordial black holes.

Speaker: Divya Singh

17:30 Primordial black holes versus their impersonators at gravitational wave observatories

Primordial black holes (PBHs) are compelling dark matter candidates and potential probes of new physics. Gravitational wave observations offer a unique avenue for detecting sub-solar mass black holes, objects not expected from known astrophysical processes.
In addition to PBHs, we consider other exotic compact object (ECO) candidates—such as strange quark stars and boson stars—which can produce similar gravitational signatures and potentially mimic PBHs.
In this talk, we will use Fisher matrix forecasts to assess the ability of next-generation detectors—Cosmic Explorer and the Einstein Telescope—to distinguish PBHs from stellar BH, neutron stars and ECOs across a wide parameter space, including mass, spin, and various equations of state.
We compute the maximum redshift at which confident ($\geq 3\sigma$) detections of sub-solar masses or tidal effects are possible, providing quantitative benchmarks for PBH identification or exclusion under various observational scenarios.
Our results indicate that next-generation detectors will be capable of probing sub-solar mass PBHs out to cosmological distances of $z \sim 3$. For heavier objects with masses up to $M \lesssim 2, M_\odot$, we show that PBHs can be distinguished from neutron stars via their lack of tidal effects up to redshifts of $z \sim 0.5$.

Speaker: Andrea Begnoni

17:50 Detecting gravitational waves with spin and condensed matter systems

I will present some of our recent proposals for detecting axions and gravitational waves using unconventional methods, such as cryogenic quantum transport technology, artificial magnetoelectric materials, and spin systems. These proposals may have promising sensitivity for axions with masses ranging from kHz to GHz, and a similar device can also be used for high-frequency gravitational wave detection within the same frequency range.

Speaker: Sichun Sun

18:10 Cosmological Constraints on Majoron Dark Matter in Vanilla Leptogenesis

In this talk, we look at some cosmological constraints on majoron dark matter in the singlet Majoron model. We consider two scenarios: pre-inflationary and post inflationary spontaneous lepton number symmetry breaking, while simultaneously demanding thermal leptogenesis to happen, and neutrino masses being generated by the type I seesaw mechanism. We derive the constraints and future prospects to probe majoron dark matter over a broad mass range. Some constraints that are particularly interesting are isocurvature constraints in pre-inflationary scenario and gravitational wave signatures in post inflationary scenario.

Speaker: Swapnil Dutta

16:30 → 18:30 Flavor physics and neutrinos

Conveners: Dean Robinson (Lawrence Berkeley National Laboratory (LBL)), Eluned Anne Smith (Massachusetts Inst. of Technology (US)), Shirley Li (UC Irvine), Yun-Tse Tsai (SLAC National Accelerator Laboratory (US)), Yun-Tse Tsai (SLAC), Yun-Tse Tsai (SLAC)

16:30 Autonomous Model Building Neutrino Flavor Theories with Reinforcement Learning

Model building in particle physics relies heavily on the intuition of theorists to select appropriate symmetry groups, particle content, and representation assignments. However, the space of viable models is vast. Exploring the space is usually computationally expensive. The challenge lies in the combinatorial complexity of symmetry and representation choices and the computational effort required to evaluate and compare a model’s predictions with experimental data. In this talk, we present the development of an Autonomous Model Builder (AMBer), a reinforcement learning framework designed to search these spaces efficiently. We apply our framework to construct neutrino flavor models that reproduce the observed mass spectrum and mixing angles while maintaining minimal field content. We apply our agent to well-studied symmetry group spaces and discover new models within spaces that have not been previously explored.

Speaker: Victoria Knapp Perez (UCI)

16:50 Neutrino Magnetic Moment, Charge Radius and Polarizability from MeV to GeV Neutrino Interactions

As neutrino experiments become more precise and explore a wide range of energies, studying how neutrinos interact with matter has become an important way to test the Standard Model and search for new physics. In this talk, I will present our work on neutrino interactions at both low (MeV) and high (GeV) energy scales. At low energies, we consider coherent elastic neutrino–nucleus scattering (CEvNS) at current and upcoming neutrino facilities. CEvNS allows to explore possible new physics effects such as non-standard neutrino interactions (NSI), neutrino magnetic moment, and charge radius. At energies relevant for DUNE, neutrinos interacting with nuclei or electrons can have enhanced couplings to photons if light scalar mediators are present, resulting in a potentially measurable neutrino polarizability. We identify two possible experimental signatures of such coupling—one or two separated electromagnetic showers with no associated hadronic activity and show the projected sensitivity for the DUNE
Near Detector.

Speaker: Sam Carey (Wayne State University)

17:10 MicroBooNE's beyond the Standard Model physics program

MicroBooNE is an 85-tonne active mass liquid argon time projection chamber (LArTPC) at Fermilab. The detector, which has an excellent calorimetric, spatial and energy resolution, has collected beam data from two different beamlines between 2015 and 2020. These characteristics make MicroBooNE a powerful detector not just to explore neutrino physics, but also for Beyond the Standard Model (BSM) physics. Additionally, MicroBooNE is investigating the observed low energy excess (LEE) of single electromagnetic shower events reported by the MiniBooNE experiment with various searches across a number of channels the anomalous excess may originate in. This talk will discuss various newly published BSM and LEE search results as well as explore future MicroBooNE searches.

Speaker: Lee Hagaman

17:30 Status of the Short-Baseline Near Detector at Fermilab

The Short-Baseline Near Detector (SBND) is one of the Liquid Argon Time Projection Chamber (LArTPC) neutrino detectors positioned along the axis of the Booster Neutrino Beam (BNB) at Fermilab, and is the near detector in the Short-Baseline Neutrino (SBN) Program. The detector completed commissioning and began taking neutrino data in the summer of 2024. SBND is characterized by superb imaging capabilities and will record around 2 million neutrino interactions per year. Thanks to its unique combination of measurement resolution and statistics, SBND will soon carry out a rich program of neutrino interaction measurements and novel searches for physics beyond the Standard Model (BSM). As the near detector, it will enable the full potential of the SBN sterile neutrino program by performing a precise characterization of the unoscillated event rate and constraining BNB flux and neutrino-argon cross-section systematic uncertainties. In this talk, the physics reach, current status, and future prospects of SBND are discussed.

Speaker: Avinay Bhat (University of Chicago)

17:50 Results from the T2K Experiment

T2K is a neutrino experiment that measures neutrino and antineutrino oscillations using a long baseline of 295km, from the neutrino beam source at JPARC in Japan, to the Super-Kamiokande detector in Kamioka. The ND280 near detector at JPARC measures the properties of the neutrino beam prior to oscillations, while SuperK measures the beam after oscillations.
In this talk, the most recent results of neutrino oscillations will be presented, featuring world-leading sensitivities on the search of Charge-Parity violation, by comparing oscillation measurements of neutrinos and antineutrinos. Measurements of the atmospheric oscillation parameters also extracted by observing the disappearance of muon neutrinos and the appearance of electron neutrinos. Combinations with other experiments such as SuperK and NOvA are also presented.

Speaker: Clark McGrew (Stony Brook Univ.)

18:10 Simulating Resonant Scattering of Boosted Dark Matter in Large Volume Neutrino Detectors

Cosmologically consistent Dark Matter models which allow for one or more component of the dark sector to receive a Lorentz boost may produce detectable signatures in terrestrial neutrino detectors. The Boosted Dark Matter (BDM) component may interact with the target material through elastic, resonant, or deep inelastic scattering. The aim of this work is to develop an event generator in GENIE for BDM resonant scattering. The hadronic model for resonant scattering is the same as neutrinos in GENIE with new helicity amplitudes. Improved sensitivity to BDM models is demonstrated with the inclusion of resonant scattering. Additionally, the dominant scattering contribution from the Delta baryon resonance is found to be suppressed for isospin conserving models and enhanced for BDM models with isospin symmetry violation.

Speaker: Zachary Orr (Colorado State University)

16:30 → 18:30 Non-SUSY extensions of the Standard Model

Conveners: Cristián Peña (Fermi National Accelerator Lab. (US)), Karri Di Petrillo (University of Chicago), Pouya Asadi (University of Oregon), Zhen Liu (University of Minnesota)

16:30 Upper Bound on The Parity Breaking Scale of WIMP Dark Matter Models

We consider weakly interacting massive particle (WIMP) dark matter in a parity solution to the strong CP problem. The WIMP phenomenology is drastically affected by the presence of parity partners of WIMP and electroweak gauge bosons. We focus on a parity extension of $SU(2)_L$ doublet fermion dark matter, identify the viable parameter space, and derive the predictions of the theory. We find that the parity symmetry breaking scale is generically bounded from above, with the bound given by $O(10)$ TeV, depending on the details of the model. The High-Luminosity Large Hadron Collider, future colliders, and direct detection experiments will probe this parameter space further.

Speaker: Matthew Baldwin

16:50 Testability of Dynamical Inflection Point Inflation at Collider Experiments

The growth of large-scale structure in the early universe remains unexplained to this day. Originally proposed by Alan Guth, inflation, which posits a brief period of rapid cosmological growth, stands as a potential explanation to this puzzle. Inflationary models use “slow roll parameters” to align predictions with cosmological constraints fixed by data from the CMB and other such experiments. Due to the constraining nature of slow roll parameters, most inflationary models are only testable at energies far from the reach of particle colliders. However, recently Yang Bai and Daniel Stolarski have proposed an interesting new inflationary model with energies falling within the detection range of current and upcoming particle colliders. We introduce a minimal setup to achieve dynamical inflection point inflation, utilizing a minimal framework. Our approach examines collider constraints on inflationary parameters using the same field composition. Specifically, we incorporate an dark SU(2)D gauge sector featuring a dark scalar doublet as the inflaton, accompanied by particle content akin to the Standard Model but with degenerate masses. This configuration facilitates the realization of multiple inflection points in the inflaton potential. Notably, all vector-like particles in the exotic content possess identical Standard Model charges, enabling the inflaton's decay into the visible sector for reheating the universe. Our study establishes a vital link between collider constraints and their implications on inflationary parameters.

Speaker: Francis Burk

17:10 Testing the lepton content of the proton at HERA and EIC

Although protons are baryons with an overall vanishing lepton number, they possess a non-trivial leptonic content arising from quantum fluctuations which can be described by lepton parton distribution functions (PDFs) of the proton. These PDFs have been recently computed and can be used to define lepton-induced processes at high-energy colliders. In this article, we propose a novel way to test the computation of lepton PDFs of the proton by analyzing both non-resonant di-lepton and resonant Z gauge boson production processes induced by leptons within the proton at proton-electron colliders like HERA and EIC. Despite the fact that lepton PDFs of the proton are known to be small, this work demonstrates that both processes imply a measurable yield of events at HERA and EIC, which could be used to test these PDFs.

Speaker: Dr Subhojit Roy (Argonne National Laboratory)

17:30 Searches for new physics with leptons using the ATLAS detector

Many different theories beyond the Standard Model (SM) predict that new physics will manifest itself by decaying into final states involving leptons. Leptoquarks are predicted by many new physics theories to describe the similarities between the lepton and quark sectors of the SM. Right-handed Ws and heavy-neutrinos are also predicted by many extensions of the SM in the gauge sector, and lepton flavour violation could manifest itself by decays of new gauge bosons into leptons of different flavours. This talk will present the most recent 13 TeV results on the searches for leptoquarks with the ATLAS detector, covering flavour-diagonal and cross-generational final states, as well as the latest searches for lepton-flavour violating Z' and heavy neutrinos arising from left-right symmetric models.

Speaker: Mr Daniele Dal Santo (Universität Bern)

17:50 .

18:10 .

Saturday 23 August

09:00 → 11:00 Plenary 13

09:00 Linear Electron Positron Colliders

Speaker: Aleksander Zarnecki (University of Warsaw (PL))

09:30 TBD

Speaker: TBD

10:00 Muon Collider

Speaker: Tao Han

10:30 TBD

Speaker: TBD

11:00 → 11:30 Coffee break

11:30 → 12:45 Closing Plenary

11:30 Vision Talk

Speaker: Hitoshi Murayama (University of California Berkeley (US))

12:00 SUSY 2026 Announcement

Speaker: Howard Baer

12:05 Farewell

Speaker: Howard Haber (University of California,Santa Cruz (US))