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...
The discovery of the Higgs boson with the mass of about 125 GeV completed the particle content predicted by the Standard Model. Even though this model is well established and consistent with many measurements, it is not capable to solely explain some observations. Many extensions of the Standard Model addressing such shortcomings introduce additional Higgs bosons, beyond-the-Standard-Model...
The discovery of the Higgs boson with the mass of about 125 GeV completed the particle content predicted by the Standard Model. Even though this model is well established and consistent with many measurements, it is not capable to solely explain some observations. Many extensions of the Standard Model addressing such shortcomings introduce additional Higgs bosons, beyond-the-Standard-Model...
High-energy $\gamma\gamma$- and $e\gamma$-collisions offer a rich phenomenological programme, complementary to $e^+e^-$ collisions at a linear collider both in kinematic as well as physics reaches. In particular, $\gamma\gamma$ collisions offer a unique setting to investigate properties of the Higgs boson(s). High polarisation of the photon beams (produced via Compton back-scattering) can be...
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...
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...
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...
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...
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...
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.
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...
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,...
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...
Results are presented for the combination of CMS Run 2 searches for new physics, interpreted in the framework of the phenomenological MSSM (pMSSM) via a scan over its 19-dimensional parameter space, using 138 fb⁻¹ of proton-proton collision data collected at 13 TeV. A global Bayesian analysis is performed, using a likelihood-based Markov Chain Monte Carlo (MCMC) approach incorporating data...
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.
We present a systematic study of one-loop quantum corrections in scalar effective field theories from a geometric viewpoint, emphasizing the role of field-space curvature and its renormalisation. By treating the scalar fields as coordinates on a Riemannian manifold, we exploit field redefinition invariance to maintain manifest coordinate independence of physical observables. Focusing on the...
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...
We present searches for additional Higgs bosons from the CMS experiment. A variety of states are searched for, at masses both above and below 125 GeV.
Various theories beyond the Standard Model predict new, long-lived particles with unique signatures which are difficult to reconstruct and for which estimating the background rates is also a challenge. Signatures from displaced and/or delayed decays anywhere from the inner detector to the muon spectrometer, as well as those of new particles with fractional or multiple values of the charge of...
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...
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...
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...
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...
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...
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...
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.
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...
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...
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...
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...
In spite of extensive searches for supersymmetric matter at LHC and SUSY WIMPs at
ton-scale noble liquid dark matter search experiments, the status of SUSY is good.
I review why early naturalness estimates overestimated finetuning while the more recent
model-independent measure DEW leaves broad swaths of natural SUSY parameter space.
Rather general arguments from the string landscape...
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.
$SU(5)$ grand unified model, which unifies SM quarks and leptons in $\overline{5}$ and $10$ dimensional irreducible representations~(irrep), yields observationally inconsistent tree-level Yukawa relations when only a single $5_{\rm H}$ or $45_{\rm H}$ dimensional irrep having a single Higgs contributes to the Yukawa sector. For instance, only $5_{\rm H}$ dimensional Higgs in the Yukawa sector...
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...
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...
We present a recomputation of the Large Hadron Collider (LHC) bounds for the Two-Higgs-Doublet Model (2HDM) extended with vector-like quarks (VLQs), building upon the reported limits for the Standard Model (SM) augmented with VLQs. Our analysis focuses on two distinct scenarios: the vector-like T singlet and the vector-like T doublet. By re-evaluating the experimental constraints and...
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....
We present the current exclusion limits for vector-like quarks (VLQs) of bottom (B) and top (T) types, based on combined ATLAS and CMS data from the LHC. For B-type VLQs, pair production excludes masses up to 1.52 TeV in doublet scenarios, while single production limits the mixing parameter κ to values between 0.2 and 0.7. For T-type VLQs, pair production excludes masses up to 1.49 TeV, with...
