Conveners
Beyond the Standard Model
- Niki Saoulidou (University of Athens, Greece)
- Antonio Sidoti (Istituto Nazionale di Fisica Nucleare)
Beyond the Standard Model
- Antonio Sidoti (Istituto Nazionale di Fisica Nucleare)
- Michal Malinsky (IPNP CU Prague)
Beyond the Standard Model
- Lesya Shchutska (EPFL)
- Michal Malinsky (IPNP CU Prague)
Beyond the Standard Model
- Lesya Shchutska (EPFL)
- Sarah Williams
Beyond the Standard Model
- Niki Saoulidou (University of Athens, Greece)
- Sarah Williams
Beyond the Standard Model
- Michal Malinsky (IPNP CU Prague)
- Antonio Sidoti (Istituto Nazionale di Fisica Nucleare)
Beyond the Standard Model
- John Conway (University of California, Davis)
- Lesya Shchutska (EPFL)
Beyond the Standard Model
- Antonio Sidoti (Istituto Nazionale di Fisica Nucleare)
- Sarah Williams
Beyond the Standard Model
- John Conway (University of California, Davis)
- Niki Saoulidou (University of Athens, Greece)
Beyond the Standard Model
- Michal Malinsky (IPNP CU Prague)
- Lesya Shchutska (EPFL)
Beyond the Standard Model
- Sarah Williams
- Lesya Shchutska (EPFL)
The $(g-2)_{\mu}$ anomaly is a longstanding problem in particle physics and many models are proposed to explain it. Leptoquark (LQ) models can be the solution to this anomaly because of the chiral enhancements. In this talk, we consider the models extended by the LQ and vector-like quark (VLQ) simultaneously. In the minimal LQ models, only the $R_2$ and $S_1$ representations can lead to the...
In recent times, several hints of lepton flavour universality violation have been observed in semileptonic B decays, which point towards the existence of New Physics beyond the Standard Model. In this context, we consider a new variant of $U(1)_{L_{\mu}-L_{\tau}}$ gauge extension of Standard Model, containing three additional neutral fermions $N_{e}, N_{\mu}, N_{\tau}$, along with a...
I will briefly discuss the signatures and discovery prospects of several new physics models containing dark matter candidates at future lepton colliders. In particular, I will discuss the IDM as well as THDMa. Based on https://arxiv.org/abs/2203.07913
The Inert Doublet Model (IDM) is a simple extension of the Standard Model, introducing an additional Higgs doublet that brings in four new scalar particles. The lightest of the IDM scalars is stable and is a good candidate for a dark matter particle. The potential of discovering the IDM scalars in the experiment at the Compact Linear Collider (CLIC), an e$^+$e$^-$ collider proposed as the next...
Many scenarios of physics beyond the Standard Model predict dark sectors containing new particles interacting only feebly with ordinary matter. Collider searches for these scenarios have largely focused on identifying signatures of new mediators, leaving much of the dark sector structure unexplored. We investigate the existence of a light dark-matter bound state, the darkonium,...
A resonant structure has been observed at ATOMKI in the invariant mass of electron-positron pairs, produced after excitation of nuclei such as $^8$Be and $^4$He by means of proton beams. Such a resonant structure can be interpreted as the production of an hypothetical particle (X17) whose mass is around 17 MeV.
The MEG-II experiment at the Paul Scherrer Institut whose primary physics goal is...
Electric charge quantization is a long-standing question in particle physics. While fractionally charged particles (millicharged particles hereafter) have typically been thought to preclude the possibility of Grand Unified Theories (GUTs), well-motivated dark-sector models have been proposed to predict the existence of millicharged particles while preserving the possibility for unification....
The Heavy Photon Search (HPS) experiment was conceived to search for a light new vector boson Aโ that is kinetically mixed with the photon and has a kinetic mixing parameter $ฮต^2 > 10^{-10}$. A vector boson with a mass in the 20-220 MeV/c$^2$ range could also mediate interactions between the Standard Model and light thermal dark matter. HPS searches for visible signatures of heavy photons in...
Today the investigation of dark matter nature, its origin, and the way it interacts with ordinary matter plays a crucial role in fundamental science. Several particle physics experiments at accelerators are searching for hidden particles signals to contribute setting more stringent limits on the characteristics of dark matter.
The Positron Annihilation into Dark Matter Experiment (PADME),...
We report on the search visible decays of exotic mediators from data taken in "beam-dump" mode with the NA62 experiment.
The NA62 experiment can be run as a "beam-dump experiment" by removing the Kaon production target and moving the upstream collimators into a "closed" position.
In 2021, more than 10^17 protons on target have been collected in this way during a week-long data-taking...
The search for Dark Matter (DM) is one of the hottest topics of modern physics. Despite the various astrophysical and cosmological observations proving its existence, its elementary properties remain to date unknown. In addition to gravity, DM could interact with ordinary matter through a new force, mediated by a new vector boson (Dark Photon, Heavy Photon or A'), kinetically mixed with the...
BESIII has collected 2.5 billion $\psi(2S)$ events and 10 billion $J/\psi$ events. The huge data
sample provide an excellent chance to search for new physics. We report the search
for the decay $J/\psi\to\gamma + invisible$, which is predicted by next-to-minimal
supersymmetric model. We also report the first search for the invisible decay of
$\Lambda$, which is predicted by the mirror...
Hidden particles can help explain many important hints for new physics, but the large variety of viable hidden sector models poses a challenge for the model-independent interpretation of hidden particle searches. We present techniques published in 2105.06477 and 2203.02229 that can be used to compute model-independent rates for hidden sector induced transitions. Adapting an effective field...
Leptoquarks are ubiquitous in several extensions of the Standard Model and seem to be able to accommodate the universality-violation-driven $B$-meson-decay anomalies and the $(g-2)_\mu$ discrepancy interpreted as deviations from the Standard Model predictions. In addition, the search for lepton-flavour violation in the charged sector is, at present, a major research program that could also be...
We study the impact of triple-leptoquark interactions on matter stability for two specific proton decay topologies that arise at the tree- and one-loop level if and when they coexist. We demonstrate that the one-loop level topology is much more relevant than the tree-level one when it comes to the proton decay signatures despite the usual loop-suppression factor. We subsequently present...
We examine new aspects of leptoquark (LQ) phenomenology using effective field theory (EFT). We construct a complete set of leading effective operators involving SU(2) singlets scalar LQ and the Standard Model (SM) fields up to dimension six. We show that, while the renormalizable LQ-lepton-quark interaction Lagrangian can address the persistent hints for physics beyond the SM in the B-decays...
Multi-lepton signals provide a relatively clean and rich testing ground for new physics (NP) at the LHC and, in particular, for searching for lepton flavor universality violation (LFUV) effects mediated by new heavy states of an underlying TeV-scale NP. The potential sensitivity of 3rd generation fermions (the top-quark in particular) to TeV-scale NP along with the persistent anomalies in...
The โ4321โ gauge models are promising extensions of the SM that give rise to the $๐_1$ vector leptoquark solution to the ๐ต-physics anomalies. Both the gauge and fermion sectors of these UV-constructions lead to a rich phenomenology currently accessible by the Large Hadron Collider. In this talk we describe some of the main LHC signatures and extract exclusion limits using run-II data. In...
Experimental hints for lepton flavor universality violation in beauty-quark decay both in neutral- and charged-current transitions require an extension of the Standard Model for which scalar leptoquarks (LQs) are the prime candidates. Besides, these same LQs can resolve the long-standing tension in the muon and the recently reported deviation in the electron $g-2$ anomalies. These tantalizing...
No stone can be left unturned in the search for new physics beyond the standard model (BSM). Since no indication of new physics was found yet, and the resources in hand are limited, we must devise novel avenues for discovery. We propose a Data-Directed Paradigm (DDP), whose principal objective is to direct dedicated analysis efforts towards regions of data which hold the highest potential for...
We present an overview of searches for new physics with top and bottom quarks in the final state, using proton-proton collision data collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV. The results cover non-SUSY based extensions of the SM, including heavy gauge bosons or excited third generation quarks. Decay channels to vector-like top partner quarks, such as...
Many theories beyond the Standard Model predict new phenomena, such as heavy vectors or scalars, as well as vector-like quarks, 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...
We discuss a complete setup for simulations, relevant for the production of a single vector-like quark at hadron colliders, including finite width effects, signal-background interference effects and next-to-leading order QCD corrections. This procedure can be extended to include additional interactions with exotic particles. We provide quantitative results for representative benchmark...
We present results of searches for massive vector-like third-generation quark and lepton partners using proton-proton collision data collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV. Pair production of vector-like leptons is studied, with decays into final states, containing third generation quarks and leptons. Vector-like quarks are studied in both single...
We present a threshold resummation calculation for the associated production of squarks and gauginos at the LHC to the next-to-leading logarithmic (NLL) accuracy, matched to next-to-leading order (NLO) QCD corrections. Analytical results are obtained for the process-dependent soft anomalous dimension and the hard matching coefficient. Numerically, the NLL contributions increase the total NLO...
Results from the CMS experiment are presented for supersymmetry searches targeting so-called compressed spectra. Those have 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. The searches use proton-proton collision data with...
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 lead to difficult searches, despite relatively clean final states. This talk will highlight the most recent results of searches performed by the ATLAS...
We study in detail the viability and the patterns of a strong first-order electroweak phase transition as a prerequisite to electroweak baryogenesis in the framework of $Z_3$-invariant Next-to-Minimal Supersymmetric Standard Model (NMSSM), in the light of recent experimental results from the Higgs sector, dark matter (DM) searches and those from the searches of the lighter chargino and...
The latest results of searches for supersymmetry in hadronic and photonic final states with the CMS experiment will be presented. The analyses are based on the full dataset of proton-proton collisions collected during the Run 2 of the LHC at a center-of-mass energy of 13 TeV.
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 for weak-scale supersymmetry 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...
The direct pair-production of the tau-lepton superpartner, stau, is one of the most interesting channels to search for SUSY. First of all the stau is with high probability the lightest of the scalar leptons. Secondly the signature of stau pair production signal events is one of the most difficult ones, yielding to the 'worst' and so most global scenario for the searches. The current...
Results from the CMS experiment are presented for searches for supersymmetric partners of the top and bottom quarks and tau leptons. A wide range of final state decays are considered in order to maximize sensitivities to different possible supersymmetric particle spectra. The searches use proton-proton collision data with luminosity up to 138 fb-1 recorded by the CMS detector at center of mass...
The latest results from combinations of multiple searches targeting the electroweak production of supersymmetric particles and top squarks will be presented. The analyses are based on the full dataset of proton-proton collisions collected during the Run 2 of the LHC at a center-of-mass energy of 13 TeV.
The long-standing mismatch between the measured muon magnetic moment and its Standard Model (SM) prediction (the so called (g-2)$_{\mu}$ anomaly) remains one of the most pressing questions in particle physics. Recently, the Muon g-2 Collaboration at Fermilab reported its latest results on the muon magnetic moment measurement. The combination of this measurement with the previous Brookhaven...
Hadronic ฯ decays are studied as probe of new physics. We determine the dependence of several inclusive and exclusive ฯ observables on the Wilson coefficients of the low-energy effective theory describing charged-current interactions between light quarks and leptons. The analysis includes both strange and non-strange decay channels. The main result is the likelihood function for the Wilson...
Metastable pionic helium is a three-body exotic atom composed of a helium nucleus, electron, and negatively-charged pion occupying a highly-excited state with principal and orbital angular momentum quantum numbers of nโl-1โ17 [1,2] with a 7 ns average lifetime. We recently used the 590 MeV ring cyclotron facility of PSI to synthesize pionic helium atoms in a helium target, and induced an...
The Deep Underground Neutrino Experiment (DUNE) is an international project aiming at neutrino physics and astrophysics and a search for phenomena predicted by theories beyond the standard model. The excellent imaging capability of Liquid Argon Time Projection Chamber (LArTPC) technology, particle tracking and identification utilized in the Far Detector allow the experiment to achieve high...
The 2020 Update for the European Strategy for Particle Physics explicitly highlights the need for programs at the so-called intensity frontier which exploit the unique potential of European laboratories. The European Spallation Source (ESS), presently under construction, in Lund, Sweden, is a multi-disciplinary international laboratory that will operate the world's most powerful pulsed neutron...
Search for possible violation of combined charge, parity, and time-reversal symmetries is yet another approach for a test of New Physics, therefore a bound state of electron and positron (positronium) as the lightest matter-antimatter system and at the same time aneigenstate of the C and P operators is an unique probe in such endeavour. The test is performed by measurement of angular...
Tests of Lorentz invariance continue to inform and challenge our modern understanding of spacetime symmetries. Using a model-independent framework based on effective field theory, generic perturbations from exact Lorentz invariance, CPT invariance, and other fundamental symmetries can be studied in a wide class of physical systems. Despite the large number of constraints extracted over the...
Several physics scenarios beyond the Standard Model predict the existence of new particles that can subsequently decay into a pair of Higgs bosons. This talk summarises ATLAS searches for resonant HH production with LHC Run 2 data. Several final states are considered, arising from various combinations of Higgs boson decays.
Many new physics models predict the existence of new particles decaying into scalar or vector bosons making these important signatures in the search for new physics. Searches for such resonances have been performed in final states with different numbers of leptons. This talk summarises ATLAS searches for diboson resonances with LHC Run 2 data in fully- and semi-leptonic final states.
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A summary of searches for heavy resonances with masses exceeding 1 TeV decaying into pairs or triplets of bosons is presented, performed on data produced by LHC pp collisions at $\sqrt{s}$ = 13 TeV and collected with the CMS detector during 2016, 2017, and 2018. The common feature of these analyses is the boosted topology, namely the decay products of the considered bosons (both electroweak W,...
We have analyzed the ATLAS sample of 4-lepton
events, in the region of invariant mass 620$\div$740 GeV. We argue
that, from these data, one can obtain a clear signal for the
existence of a new scalar resonance. Looking for its possible
interpretation, we have compared with the hypothetical second
resonance of the Higgs field that has been recently proposed
and which would couple to...
Many extensions to the Standard Model predict new particles decaying into two bosons (W, Z, photon, or Higgs bosons) making these important signatures in the search for new physics. Searches for such diboson resonances have been performed in different final states and novel analysis techniques, including unsupervised learning, are also used to extract new features from the data. This talk...
In various models beyond the standard model, the Higgs sector is extended, and some new scalar bosons are introduced. One of the interesting candidates is the doubly charged scalar boson from the isospin doublet with Y=3/2. It is often introduced in models for the radiative generation of the neutrino mass. However, its phenomenology had not been fully investigated. We have investigated how to...
In this work, we derive lower mass bounds on the $Z^\prime$ gauge boson based on the dilepton data from LHC with 13 TeV of center-of-mass energy, and forecast the sensitivity of the High-Luminosity-LHC with $L=3000 fb^{-1}$, the High-Energy LHC with $\sqrt{s}=27$~TeV, and also at the Future Circular Collider with $\sqrt{s}=100$~TeV. We take into account the presence of exotic and invisible...
In scenarios beyond the Standard Model (BSM) characterised by charged (W') or neutral (Z') massive gauge bosons with large width, resonant mass searches are not very effective, so that one has to exploit the tails of the mass distributions measured at the Large Hadron Collider (LHC). In this case, the LHC sensitivity to new physics signals is influenced significantly by systematic...
Many theories beyond the Standard Model predict new phenomena, such as Z, W bosons, KK gravitons, or heavy leptons, in final states with isolated, high-pt leptons (e/mu/tau) or photons. Searches for new physics with such signatures, produced either resonantly or non-resonantly, are performed using the ATLAS experiment at the LHC. This includes a novel search that exploits the lepton-charge...
Many new physics models, such as the Sequential Standard Model, Grand Unified Theories, models of extra dimensions, or models with eg. leptoquarks or vector-like leptons, predict heavy mediators at the TeV energy scale. We present recent results of such searches in leptonic final states obtained using data recorded by the CMS experiment at Run-II of the LHC.
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...
Many new physics models, e.g., compositeness, extra dimensions, extended Higgs sectors, supersymmetric theories, and dark sector extensions, are expected to manifest themselves in the final states with hadronic jets. This talk presents searches in CMS for new phenomena in the final states that include jets, focusing on the recent results obtained using the full Run-II data-set collected at the LHC.
Leptoquarks are predicted by many new physics theories to describe the similarities between the lepton and quark sectors of the Standard Model and offer an attractive potential explanation for the lepton flavour anomalies observed at LHCb and flavour factories. The ATLAS experiment has a broad program of direct searches for leptoquarks, coupling to the first-, second- or third-generation...
Many new physics models predict low mass resonances. However, the kinematic thresholds used in the nominal data taking program of CMS pose a difficulty in kinematically accessing these resonances. To overcome this problem, CMS has implemented Data Scouting Techniques that allow trigger thresholds to be lowered by saving a very limited amount of trigger-level event information offline. In this...
The electron-positron stage of the Future Circular Collider (FCC-ee) is a frontier factory for Higgs, electroweak, QCD and flavour physics. It is designed to operate in a 100 km circular tunnel built at CERN, and will serve as the first step towards 100-TeV proton-proton collisions. In addition to an essential and unique Higgs program, FCC-ee offers powerful opportunities to discover direct or...
We propose a two-stage strategy to search for new long-lived particles that could be produced at the CERN LHC, become trapped in detector material, and decay later. In the first stage, metal rods are exposed to LHC collisions in an experimental cavern. In the second stage, they are immersed in liquid argon at a different location, where out-of-time decays could be detected. Using a benchmark...
The proposed MATHUSLA experiment (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) could open a new avenue for discovery of Physics Beyond the Standard Model at the LHC. The large-volume detector will be placed above the CMS experiment with O(100) m of rock separation from the LHC interaction point. It is instrumented with a tracking system to observe long-lived particle decays...
Many models beyond the standard model predict new particles with long lifetimes, such that the position of their decay is measurably displaced from their production vertex, and particles giving rise to other non-conventional signatures. We present recent results of searches for long-lived particles and other non-conventional signatures obtained using data recorded by the CMS experiment at...
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...
The MoEDAL experiment deployed at IP8 on the LHC ring was the first dedicated search experiment to take data at the LHC in 2010. It was designed to search for Highly Ionizing Particle (HIP) avatars of new physics such as magnetic monopoles, dyons, Q-balls, multiply charged particles, massive slowly moving charged particles and long-lived massive charge SUSY particles. We shall report on our...
Axion-like particles (ALPs) are at the forefront of physics research, especially at the intensity frontier, dealing with light weakly coupled particles. A plethora of different experiments searches for signals of the ALP in many different final states using innovative search strategies. We present a different perspective on ALP searches, concentrating on the modifications that such a particle...
Many extensions of the Standard Model include the possibility of light new particles, such as axions candidates. These scenarios can be probed using the large data sets collected by $B$-factories, complementing measurements performed at the LHC. We report on a search for an Axion-like particle (ALP), $a$, produced in the Flavor-Changing Neutral-Current decay $B\to K a$, with $a\to...
Coherent CAPTAIN-Mills (CCM) is a 10 ton liquid argon scintillation detector located at Los Alamos National Lab. The prototype detector CCM120 was fabricated in 2017, which utilized 120 PMTs, and now the upgraded detector CCM200, with 200 PMTs, has collected data in the 2021 run cycle. The physics program of CCM comprises searches for new particles in the weak sector, including Dark Photons,...
It is well known that the Sun represents an efficient and intense source of axions. We aim to study such axions and analyze their properties using the terrestrial neutrino oscillation experiment JUNO. We consider the Compton conversion, axions decay to the photon, and inverse Primakoff conversion processes in order to analyze the axion detection signatures. In this talk, will be presented a...
The proposed LUXE experiment (LASER Und XFEL Experiment) at DESY, Hamburg, using the electron beam from the European XFEL, aims to probe QED in the non-perturbative regime created in collisions between high-intensity laser pulses and high-energy electron or photon beams. This setup also provides a unique opportunity to probe physics beyond the standard model. In this talk we show that by...
Although the LHC experiments have searched for and excluded many proposed
new particles up to masses close to 1 TeV, there are many scenarios that
are difficult to address at a hadron collider. This talk will review a
number of these scenarios and present the expectations for searches at an
electron-positron collider such as the International Linear Collider.
The cases discussed include...
We study the possibility of measuring neutrino Yukawa couplings in the Next-to-
Minimal Supersymmetric Standard Model with right-handed neutrinos (NMSSMr) when the lightest right-sneutrino is the Dark Matter (DM) candidate, by exploiting a โdijet + dilepton + Missing Transverse Energyโ (MET) signature. We show that, contrary to the minimal realisation of Supersymmetry (SUSY), the MSSM,...
MicroBooNE is an 85-tonne active mass liquid argon time projection chamber (LArTPC) at Fermilab. It has excellent calorimetric, spatial and energy resolution and is exposed to two neutrino beams, which make it a powerful detector not just for neutrino physics, but also for Beyond the Standard Model (BSM) physics. The experiment has competitive sensitivity to heavy neutral leptons possibly...
This talk presents a model independent search for an additional heavy, mostly sterile, neutral lepton (HNL) which is capable of mixing with the Standard Model tau neutrino with a mixing strength of $|U_{\tau 4}|^{2}$, corresponding to the square of the extended ย PontecorvoโMakiโNakagawaโSakata (PMNS) matrix element. HNLs are hypothetical particles predicted by many beyond Standard Model...
The LHeC and the FCC-he offer fascinating, unique possibilities for discovering BSM physics in DIS, both due to their large centre-of-mass energies and high luminosities. In this talk we will show the prospects for observing extensions of the Higgs sectors both with charged and neutral scalars, anomalous Higgs couplings and exotic decays. Then we will discuss searches for R-parity conserving...
The smallness of neutrino masses, together with neutrino oscillations could be pointing to physics beyond the standard model, can be naturally accommodated by the so-called "seesaw" mechanism, in which new Heavy Neutral Majorana Leptons (HNL) are postulated. Several models with HNLs exist that incorporate the seesaw mechanism, sometimes also providing a DM candidate or giving a possible...
Extensions of the Standard Model with right handed (sterile) neutrinos pose viable explanations for the origin of neutrino masses and could solve a variety of open questions in physics such as neutrino oscillation anomalies, the nature of dark matter, and baryon asymmetry. Multiple models posit the existence of a GeV-scale, sterile neutrino (also called a Heavy Neutral Lepton (HNL)), which...
Neutrinos are probably the most mysterious particles of the Standard Model. The mass hierarchy and oscillations, as well as the nature of their antiparticles, are currently being studied in experiments around the world. Moreover, in many models of New Physics, baryon asymmetry or dark matter density in the universe are explained by introducing new species of neutrinos. Among others, heavy...
We exhibit the geometric structure of the convex cone in the linear space of the Wilson coefficients for the dimension-8 operators involving the left-handed lepton doublet $L$ and the Higgs doublet $H$ in the Standard Model effective field theory (SMEFT). The boundary of the convex cone gives rise to the positivity bounds on the Wilson coefficients, while the extremal ray corresponds to the...
