ALPS2023 -- Anomalies in Particle Physics

UZ Obergurgl

UZ Obergurgl

University Center Obergurgl Gaisbergweg 5 6456 Obergurgl Austria
Abdul Basith Kaliyar (Austrian Academy of Sciences (AT)), Andreas Crivellin (co-chair) (University of Zurich (CH)), Brigitte DeMonte (secretary), Gianluca Inguglia (chair) (Austrian Academy of Sciences (AT)), Josef Pradler (co-chair) (Austrian Academy of Sciences (AT))

Continuing the yearly tradition since 2016 and restarting after COVID, we will meet in the Austrian Alps to an "ALpine Particle physics Symposium" (ALPS)  to discuss recent results and developments in experimental and theoretical particle physics. This meeting will have a focus on anomalous experimental and observational results in particle physics and related fields.

The dates of the meeting are March 26 - 31, 2023 and the following topics are at the focus of the meeting:

  • Quark Flavour Anomalies (B anomalies, CKM Unitarity)
  • g-2, leptons, EW fit
  • Direct searches at LHC
  • Neutrinos, Dark Matter and cosmology

The days will feature invited keynote talks as well as shorter presentations  and a Young Scientist Forum. The meeting will take place at the Obergurgl University Centre, in the ski-resort town of Obergurgl, located in the upper Oetztal Valley in Tyrol, Austria.

Confirmed speakers (senior and junior):


Prafulla Behera 
Kim Berghaus  
Jorge Camalich  
Bernat Capdevilla 
Xiaoyong Chu 
Eung Jin Chun  
Pilar Coloma  
Patrizia De Simone
Giulio Dujany  
Gernot Eichmann  
John Ellis  
Nina Elmer  
Lisa Fantini
Anna Ferrari
Martina Ferrillo
Javier Fuentes-Martin
Zuzana Gruberova  
Diego Guadagnoli  
Shubham Gupta
Theo Heimel  
Martin Hoferichter  
Alejandro Ibarra
Syuhei Iguro  
Alberto Lusiani
Chaoyi Lyu
Eleanor Jones
Henrik Junkerkalefeld  
Felix Kahlhöfer  
Haruki Kindo  
Greg Landsberg  
Maciej Lewicki
Simone Quitadamo
Elizabeth Sarah Long  
Nadia Maslova  
Quim Matias  
Bruce Mellado  
Lachlan Milligan  
Tanmoy Modak  
Stefano Moneta  
Enrico Nardi  
Vivian Poulin  
Simone Quitadamo  
Navid Rad   
Josh Ruderman  
Luka Santelj 
Bisnupriya Sahu
Pedro Schwaller
Thomas Schwetz   
Dominik Stockinger  
Andreas Trautner
Tomer Volansky
Felix Wagner


Local Organizers (HEPHY):

  • Gianluca Inguglia (chair)
  • Mokina Valentyna
  • Abdul Basith Kaliyar
  • Brigitte De Monte (secretary)

Local Organizers (PSI Villingen):

  • Andreas Crivellin (co-chair)

Local Organizers (University of Graz):

  • Reinhard Alkofer

Local Organizers (University of Vienna & HEPHY):

  • Josef Pradler (co-chair)
    • 6:30 PM
    • Opening session
      • 1
        Welcome from the organisers
        Speakers: Gianluca Inguglia (Austrian Academy of Sciences (AT)), Reinhard Alkofer (University of Graz)
      • 2
        Anomalies in cosmology (45+15)
        Speaker: Dr Vivian Poulin (LUPM, CNRS & U. de Montpellier, France)
    • 9:15 PM
    • Keynotes
      • 3
        Status of flavour anomalies from LHCb (20+10)
        Speakers: Patrizia De Simone (INFN e Laboratori Nazionali di Frascati (IT)), Patrizia De Simone (Istituto Nazionale Fisica Nucleare (IT))
      • 4
        LFU and semileptonic B decays at Belle (20+10)
        Speaker: Luka Santelj (Jozef Stefan Institute)
      • 5
        b->sll transitions (20+10)
        Speaker: Bernat Capdevila (IFAE)
    • 10:00 AM
    • Keynotes
      • 6
        Recent semileptonic results from Belle II (20+10)
        Speaker: Chaoyi Lyu
      • 7
        Latest flavour physics results from CMS/ATLAS (20+10)
        Speaker: Prof. Prafulla Behera (Indian Institute of Technology Madras (IN))
      • 8
        New Physics in b->sll and b->ctaunu (20+10)
        Speaker: Syuhei Iguro (Nagoya University)
    • 12:00 PM
    • Keynotes/Contributed Talks
      • 9
        Anomalies in hadronic B decays (20+10)
        Speaker: Quim Matias
      • 10
        Latest results and precision measurement from the NA62 experiment (20+10)
        Speaker: Silvia Martellotti (INFN e Laboratori Nazionali di Frascati (IT))
    • 5:45 PM
    • Keynotes/Contributed Talks
      • 11
        Recent Belle II results related to flavor anomalies (20+10)
        Speaker: Stefano Moneta
    • Young Scientist Forum
      • 12
        Rare B decays from Belle (10+5)
        Speaker: Nadiia Maslova (Austrian Academy of Sciences (AT))
      • 13
        Results from LHCb on LFU tests in b->clnu transitions (10+5)
        Speaker: Martina Ferrillo (University of Zurich (CH))
      • 14
        Lepton number and LFV searches in B decays at LHCb (10+5)
        Speaker: Lisa Fantini (Universita e INFN, Perugia (IT))
    • 8:00 PM
    • Keynotes
      • 15
        tau physics at Belle II (20+10)
        Speaker: Navid Khandan Rad
      • 16
        Status and prospects of the Muon g-2 experiment at FNAL (20+10)

        After the 0.46 ppm measurement in 2021, the Muon g-2 experiment at FNAL aims at measuring the muon anomaly with a 0.23 precision in 2023 and later with a precision matching the design of 0.14 ppm.

        Speaker: Alberto Lusiani (Scuola Normale Superiore and INFN, sezione di Pisa)
    • Young Scientist Forum
      • 17
        Two Invertible Networks for the Matrix Element Method (10+5)

        The matrix element method is widely considered the ultimate LHC inference tool for small event numbers, but computationally expensive. We show how a combination of two conditional generative neural networks encodes the QCD radiation and detector effects without any simplifying assumptions, and allows us to efficiently compute likelihoods for individual events. We illustrate our approach for the CP-violating phase of the top Yukawa coupling in associated Higgs and single-top production. Currently, the limiting factor for the precision of our approach is jet combinatorics.

        Speaker: Theo Heimel (Heidelberg University)
      • 18
        To Profile or To Marginalize - A SMEFT case study (10+5)
        Speaker: Nina Elmer
    • 10:00 AM
    • Keynotes
      • 19
        g-2 and new physics (30+15)
        Speaker: Dominik Stockinger (IPPP Durham)
      • 20
        The Cabibbo angle anomaly and EW fits (30+15)
        Speaker: Martin Hoferichter
    • 12:00 PM
    • Keynotes/Contributed Talks
      • 21
        Latest results from CUORE (20+10)
        Speaker: Simone Quitadamo (GSSI (Gran Sasso Science Institute))
      • 22
        The search for Charged Lepton Flavour Violation with the Mu2e experiment (20+10)

        The Mu2e experiment, currently under construction at Fermilab (USA), will search for the charged-lepton flavor violating neutrino-less conversion of negative muons into electrons in the field of an aluminum nucleus. A conversion signal would require physics beyond the Standard Model, and the aim of Mu2e is to reach a sensitivity four orders of magnitude better than previous experiments.
        To achieve such a goal, a reliable estimate of the relevant particle yields and a rigorous control of all backgrounds are mandatory, together with an accurate normalization of signal events.
        An extensive campaign of Monte Carlo simulations has been therefore performed to investigate key yields, and beam and cosmic rays-related backgrounds.
        The normalization of the signal events will be done with a detector system made of a HPGe detector and a Lanthanum Bromide detector, which will measure the rate of muons stopped on the aluminum target by looking at the emitted characteristic X-and γ-rays of energies up to 1809 keV . At the Helmholtz-Zentrum Dresden-Rossendorf the pulsed Bremsstrahlung photon beam at the ELBE facility has been used to study the performance of this detector system under timing and background conditions very similar to the ones expected at Mu2.
        The design and present status of the Mu2e experiment will be presented, together with the main results of the background and sensitivity studies, and a summary of the results of the ELBE campaign.

        Speaker: Dr Anna Ferrari (Helmholtz-Zentrum Dresden-Rossendorf)
    • 5:45 PM
    • Keynotes
      • 23
        QCD contributions to the muon anomalous magnetic moment (20+10)

        The anomalous magnetic moment (g-2) of the muon continues to be one of the most promising places to look for evidence of new physics. First measurements at Fermilab have confirmed the previous Brookhaven result and slightly increased the tension with the Standard Model prediction to 4.2 standard deviations. The theoretical value is the sum of QED, electroweak and QCD contributions, where the hadronic parts are the most difficult to calculate and responsible for almost all of the theory uncertainty. The leading hadronic contribution is the hadronic vacuum polarization, whereas the hadronic light-by-light scattering contribution is much smaller but comes with a similar theoretical uncertainty. In this talk I will present an overview of the problem and the various approaches to compute the hadronic parts from dispersion theory, lattice QCD and functional methods. I will focus in particular on the hadronic light-by-light contribution and discuss the different strategies in its computation.

        Speaker: Gernot Eichmann
    • Young Scientist Forum
      • 24
        The CUPID double beta decay experiment (10+5)

        Neutrinoless double-beta decay (0$\nu\beta\beta$) is a key process to address some of the major outstanding issues in particle physics, such as the lepton number conservation and the Majorana nature of the neutrino. Several efforts have taken place in the last decades in order to reach higher and higher sensitivity on its half-life. The next-generation of experiments aims at covering the Inverted-Ordering region of the neutrino mass spectrum, with sensitivities on the half-lives greater than 10$^{27}$ years. Among the exploited techniques, low-temperature calorimetry has proved to be a very promising one, and will keep its leading role in the future thanks to the CUPID experiment. CUPID (CUORE Upgrade with Particle IDentification) will search for the neutrinoless double-beta decay of $^{100}$Mo and will exploit the existing cryogenic infrastructure as well as the gained experience of CUORE, at the Laboratori Nazionali del Gran Sasso in Italy. Thanks to 1596 scintillating Li$_2$MoO$_4$ crystals, enriched in $^{100}$Mo, coupled to 1710 light detectors CUPID will have a simultaneous readout of heat and light that will allow for particle identification, and thus a powerful alpha background rejection. Numerous studies and R&D projects are currently ongoing in a coordinated effort aimed at finalizing the design of the CUPID detector and at assessing its performance and physics reach.
        In our talk, we will present the current status of CUPID and outline the forthcoming steps towards the construction of the experiment.

        Speakers: Antoine Armatol (CEA IRFU/DPhP), The CUPID Collaboration
    • 7:00 PM
      Conference Dinner

      Weather permitting at 'Hohe Mut' on top of the mountain.

    • Keynotes
      • 25
        Overview and LHC searches for New Physics (30+15)
        Speaker: Greg Landsberg (Brown University (US))
      • 26
        Overview of LHC anomalies (30+15)
        Speaker: Bruce Mellado Garcia (University of Wisconsin)
    • 10:00 AM
    • Young Scientist Forum
      • 27
        Overview of ATLAS forward proton detectors: status, performance and new physics results (10+5)
        Speaker: Maciej Piotr Lewicki (Polish Academy of Sciences (PL))
      • 28
        Search for dark matter in Higgs to tau tau and MET final state using Run2 data at CMS (10+5)

        The result presents the search for dark matter produced in association with Higgs boson decaying into a pair of τ leptons performed in proton-proton collisions at a center-of-mass energy of 13 TeV with the CMS detector at CERN LHC. The data used in the study has been collected during Run-2 of CMS running and corresponds to an integrated luminosity of 137 fb − 1 . The results are interpreted in framework of 2HDM+a model where a lighter and heavier pseudo-scalar mediator couples to the pairs of τ leptons and then decay to two dark matter particle. The results are also interpreted using production mechanisms of Two Higgs Doublet Model where a high mass resonance Z decays into A0 and standard model Higgs boson, and on parameters of baryonic Z’ simplified model.

        Speaker: Bisnupriya Sahu (University of Hyderabad,India)
      • 29
        Search for heavy Higgs bosons in top-antitop final states at ATLAS (10+5)
        Speaker: Eleanor Jones (University of Warwick (GB))
    • Keynotes: Automatized One-Loop Matching of BSM Models
      Convener: Javier Fuentes-Martin (Universidad de Granada)
    • 12:00 PM
    • Keynotes/Contributed Talks
      • 30
        The X17
        Speaker: Enrico Nardi (INFN e Laboratori Nazionali di Frascati (IT))
      • 31
        Study of the X17 anomaly with the PADME experiment (20+10)
        Speaker: Elizabeth Sarah Long
    • 5:45 PM
    • Keynotes/Contributed Talks
      • 32
        Latest dark sector results from e+ e- colliders (20+10)

        Many experiments are conducted to search for Dark Matter. In addition to the experiments detecting the Dark Matters through elastic scattering of nucleii, collider experiments can search for Dark Matter that are produced in the particle reactions.
        We report the result of Belle experiment searching for Dark Photon ($A'$) in MeV region using a charmed decay.
        The Belle experiment had been operated from 1999 to 2010 and the integrated luminosity is about 1 ab$^{-1}$. The high statistics sample can be utilized for the search of Dark Matter which is considered to be rarely produced.
        Dark Photon, a part of Dark Matter model called Hidden Sector hypothesis, is predicted to have mixing with Standard Model photon. We use $D^{*0}\to D^0A'(\to e^+e^-)$ decay in data accumulated by Belle experiment that produces $c\bar{c}$ pair as well as $B\overline{B}$ meson pair. A process $D^{*0}\to D^0A'$ may occur by a mixing between $\gamma$ and $A'$ in $D^{*0}\to D^0\gamma$. The mass difference between $D^{*0}$ and $D^0$ is 142 MeV, so this is suitable to search for MeV scale Dark Photon.
        In this presentation, we also review the recent searches for Dark Matter in $e^+e^-$ collider experiments; Belle, Belle2, and BaBar.

        Speaker: Haruki Kindo
      • 33
        Supernova constraints on dark flavored sectors (20+10)
        Speaker: Jorge Martin Camalich (Institute of Astrophysics of the Canary Islands (ES))
      • 34
        Probing extended Starobinsky inflation with CMB and 21cm intensity mapping (15+5)

        The Starobinsky inflation where the general relativity is extended by $R^2$ term is one of bestfit model to Planck data. Higher order modification to Starobinsky model with $R^3$ term is of great interest since it may be induced by quantum gravity effects. In this article we
        study the potential of future CMB experiments LiteBIRD and CMB stage four (CMB-S4) and 21cm intensity mapping by Square Kilometre Array (SKA) to probe Starobinsky model extended by R3 term. Such an extend model would provide intriguing insight about inflationary dynamics.

        Speaker: Tanmoy Modak
    • Young Scientist Forum
      • 35
        Higgs physics at a future Muon Collider (10+5)

        A multi-TeV muon collider is one of the best candidates under investigation for the future development of high energy particle physics. Since the discovery of the Higgs boson at the LHC in 2012, a great effort has been made in order to probe its properties. Nevertheless, almost all the Higgs boson couplings to second and third generation fermions and self couplings are still out of reach and, unfortunately, will not be completely accessed even at the High Luminosity era of LHC (HL-LHC). For this reason, one of the main goals future colliders have to accomplish is the measurement of the Higgs boson couplings with a precision of a few percent.
        A 14 TeV muon collider with sufficient luminosity would provide a similar discovery reach as a 100 TeV hadron collider. Moreover, a muon collider would lose much less synchrotron radiation than an analogous electron-positron machine.
        At a multi-TeV muon collider, the vector boson fusion/scattering would be the dominant production mechanism, allowing us to study with high precision all the Standard Model processes and, if possible, probe for new physics. With sufficient luminosity, it would also be possible to directly measure the Higgs boson trilinear and quadrilinear self-couplings, necessary to determine the Higgs potential.
        In order to investigate the physics potential of such a facility, the International Muon Collider Collaboration (IMCC) has developed a framework to perform detailed simulations of the physics processes of interest, which include a realistic detector response. This work will give an overview of a selected set of results, focusing on the Higgs boson couplings.

        Speaker: Angela Zaza (Universita e INFN, Bari (IT))
      • 36
        Searches for low scale resonances decaying to WW (10+5)
        Speaker: Guglielmo Coloretti (University of Zurich (UZH) / Paul Scherrer Institute (PSI))
    • 8:05 PM
    • Keynotes
      • 37
        TBA (20+10)
        Speaker: Tomer Volansky (Tel Aviv University (IL))
      • 38
        Short baseline anomalies (20+10)
        Speaker: Pilar Coloma (Universidad Autónoma de Madrid)
      • 39
        Tensions between terrestrial and cosmological neutrino mass determinations (20+10)
        Speaker: Thomas Schwetz
    • 10:00 AM
    • Keynotes
      • 40
        21cm and the radio background excess (20+10)
        Speakers: Joshua Ruderman (Princeton University), Joshua Thomas Ruderman (NYU)
      • 41
        New constraints on the dark matter-neutrino and the dark matter-photon scattering cross-sections (20+10)

        The flux of high energy neutrinos and photons produced in active galactic nuclei could get attenuated when they propagate through the dark matter spike around their central black hole. Using measurements of the neutrino and the gamma-ray fluxes from TXS 0506+056 and from NGC 1068 by IceCube and the Fermi-LAT we derive new constraints on the dark matter-neutrino and the dark matter-photon scattering cross sections. Our constraints are orders of magnitude more stringent than those derived from considering the attenuation through the intergalactic medium and the Milky Way dark matter halo. We also briefly discuss the implication for some specific dark matter scenarios.

        Speaker: Alejandro Ibarra
      • 42
        Small-scale tensions and self-interacting dark matter
        Speaker: Felix Kahlhoefer (Karlsruhe Institute of Technology)
    • 12:00 PM
    • Keynotes/Contributed Talks
      • 43
        The Cosmology of Dark Energy Radiation (20+10)
        Speaker: Kim Berghaus (Stony Brook University)
      • 44
        GRB221009A high energy gamma ray excess and new physics explanations
        Speaker: Andreas Trautner
    • 5:45 PM
    • Keynotes/Contributed Talks
      • 45
        MeV dark matter in the interplay of visible and neutrino sectors

        MeV-scale thermal dark matter has its abundance set during the highly non-trivial epochs of neutrino decoupling and electron annihilation. We study this problem by solving the Boltzmann equations of multiple interacting sectors being both relativistic and non-relativistic. We show that the freeze-out of thermal MeV dark particles has subtle effects on Neff, as well as on other cosmological observables, depending on the annihilation/scattering channels.

        Speaker: Xiaoyong Chu (Institute of High Energy Physics (Vienna, Austria))
    • Young Scientist Forum
      • 46
        The SABRE South Experiment at the Stawell Underground Physics Laboratory (10+5)

        The SABRE (Sodium iodide with Active Background REjection) experiment aims to detect an annual rate modulation from dark matter interactions in ultra-high purity NaI(Tl) crystals in order to provide a model independent test of the signal observed by DAMA/LIBRA. It is made up of two separate detectors; SABRE South located at the Stawell Underground Physics Laboratory (SUPL), in regional Victoria, Australia, and SABRE North at the Laboratori Nazionali del Gran Sasso (LNGS).

        SABRE South is designed to disentangle seasonal or site-related effects from the dark matter-like modulated signal by using an active veto and muon detection system. Ultra-high purity NaI(Tl) crystals are immersed in a linear alkyl benzene (LAB) based liquid scintillator veto, further surrounded by passive steel and polyethylene shielding and a plastic scintillator muon veto. Significant work has been undertaken to understand and mitigate the background processes, that take into account radiation from the detector materials, from both intrinsic and cosmogenic activated processes, and to understand the performance of both the crystal and veto systems.

        SUPL is a newly built facility located 1024 m underground (~2900 m water equivalent) within the Stawell Gold Mine and its construction has been completed in mid-2022. The laboratory will house rare event physics searches, including the upcoming SABRE dark matter experiment, as well as measurement facilities to support low background physics experiments and applications such as radiobiology and quantum computing. The SABRE South commissioning is expected to occur in 2023.

        This talk will report on the design of SUPL and the general status of the SABRE South assembly.

        Speakers: Irene Bolognino (The University of Adelaide), Lachlan Milligan
      • 47
        Latest results from CRESST (10+5)
        Speaker: Shubham Gupta (CRESST)
      • 48
        Latest news from COSINUS (10+5)
        Speaker: Felix Wagner (HEPHY Vienna)
    • Keynotes
      • 49
        Bd,s → μ+ μ– γ phenomenology overview
        Speakers: Diego Guadagnoli, Diego Guadagnoli (LAPTh Annecy), Diego Guadagnoli (Universite Paris XI), Diego Guadagnoli (Technical University Munich)
    • 8:00 PM
    • Keynotes
      • 50
        Ultralight dark matter generated by thermal fermions
        Speaker: Eung Jin Chun
      • 51
        Nanograv anomaly
        Speaker: Pedro Klaus Schwaller (Mainz University)
    • 9:30 AM
    • Closing session
      • 52
        The future of particle physics
        Speaker: Prof. John Ellis