Conveners
Searches for the BSM Physics at the LHC and Future Hadronic Colliders
- Zhaofeng Kang
Searches for the BSM Physics at the LHC and Future Hadronic Colliders
- Shufang Su (University of Arizona)
Searches for the BSM Physics at the LHC and Future Hadronic Colliders
- Xin Gao (Sichuan University)
Searches for the BSM Physics at the LHC and Future Hadronic Colliders
- Robin Erbacher (University of California Davis (US))
Searches for the BSM Physics at the LHC and Future Hadronic Colliders
- Robin Erbacher (University of California Davis (US))
Searches for the BSM Physics at the LHC and Future Hadronic Colliders
- Eung Jin Chun (Korea Institute for Advanced Study)
Searches for the BSM Physics at the LHC and Future Hadronic Colliders
- Ning Chen (Nankai University)
Searches for the BSM Physics at the LHC and Future Hadronic Colliders
- Eung Jin Chun (Korea Institute for Advanced Study)
Searches for the BSM Physics at the LHC and Future Hadronic Colliders
- Zhaofeng Kang
Searches for the BSM Physics at the LHC and Future Hadronic Colliders
- Shufang Su (University of Arizona)
Many extensions of the standard model predict new particles with long lifetimes or other properties, that give rise to non-conventional signatures in the detector. We present recent results of searches for new physics from such non-conventional signatures obtained using data recorded by the CMS experiment using the full Run-II LHC data-set.
A quirk propagating through a detector is subject to the Lorentz force, a new confining gauge force, and the frictional force from ionization energy loss. At the LHC, it was found that the monojet search and the coplanar search were able to constrain such a quirk signal. Inspired by the coplanar search proposed by S. Knapen et. al, we develop a new search that also utilizes the information of...
We explore the direct Higgs-top CP structure via the $pp \to t\bar{t}h$ channel with machine learning techniques, considering the clean $h \to \gamma\gamma$ final state at the high luminosity LHC~(HL-LHC). We show that a combination of a comprehensive set of observables, that include the $t\bar{t}$ spin-correlations, with mass minimization strategies to reconstruct the $t\bar{t}$ rest frame...
In several searches for additional Higgs bosons at the LHC,
in particular the CMS search in the·
$pp \to \phi \to t \bar t$ channel and the ATLAS search in·
the $pp \to \phi \to \tau^+\tau^-$
channel, a local excess at
the level of $3\,\sigma$ or above has been observed·
at a mass scale of $m_\phi \approx 400$GeV.·
We investigate to what extent a possible signal in those
channels could...
We discuss a ∼ 3 σ signal (local) in the light Higgs-boson search in the diphoton decay mode at ∼ 96 GeV as reported by CMS, together with a ∼ 2 σ excess (local) in the b̄b final state at LEP in the same mass range. We interpret this possible signal as a Higgs boson in the 2 Higgs Doublet Model with an additional complex Higgs singlet (2HDMS). We find that the lightest CP-even Higgs boson of...
The presence of charged Higgs bosons is a generic prediction of multiplet extensions of the Standard Model (SM) Higgs sector. Focusing on the Two-Higgs-Doublet-Model (2HDM), we discuss the charged Higgs boson collider phenomenology in the theoretically and experimentally viable parameter space. While almost all existing experimental searches at the LHC target the fermionic decays of charged...
We explore the possibility of displaced Higgs production from the decays of the heavy fermions in the Type-III seesaw extension of the Standard Model at the LHC/FCC and the muon collider. The displaced heavy fermions and the Higgs boson can be traced back by measuring the displaced charged tracks of the charged leptons along with the $b$-jets. The prospects of the transverse and longitudinal...
We present a summary of searches for new heavy resonances decaying into pairs or triplets of bosons, performed on proton-proton collision data collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV. A common feature of these analyses is the boosted topology, namely the decay products of the considered bosons (both electroweak W, Z bosons and the Higgs boson) are...
Leptoquarks (LQ) 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...
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 are also...
Missing transverse momentum (MET) is a critical observable for physics searches in proton-proton collisions at the Large Hadron Collider. This talk describes these various novel approaches and their performance. ATLAS employs a suite of working points for missing transverse momentum (MET) reconstruction, and each is optimal for different event topologies. A new neural network can exploit...
The Bell inequality is a principal touchstone of testing the local realism posited by Einstein at the time of the formation of quantum theory. The violations of the Bell inequality have been found with the measured system of photons, electrons or nucleons at low energies, which reject local realism. Extending to systems with higher energies will be important for establishing the nonlocal...
The reconstruction and calibration of hadronic final states is an extremely challenging experimental aspect of measurements and searches at the LHC. This talk summarizes the latest results from ATLAS for jet reconstruction and calibration. New approaches to jet inputs better utilize relationships between calorimeter and tracking information to significantly improve the reconstruction of jet...
The minimal U$(1)_𝑋$ extension of the Standard Model (SM) is a simple and well-motivated extension of the SM, which supplements the SM with the seesaw mechanism for naturally generating the light neutrino masses and offers various interesting phenomenologies.In the model, the U$(1)_𝑋$ charge of each SM field is characterized by the U$(1)_𝑋$ charge of the SM Higgs doublet with a free parameter...
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 leptons and photons. This talk presents searches in CMS for new phenomena in the final states that include leptons and photons, focusing on the recent results obtained using the full Run-II...
Abstract
Recently, there has been great interest in beyond-the-Standard Model (BSM) physics involving new low-mass matter and mediator particles. One such model, U(1)T3R, proposes a new U(1) gauge symmetry under which only right-handed fermions of the standard model are charged, as well as the addition of new vector-like fermions (e.g., chi_t) and a new dark scalar particle (phi) whose vacuum...
Vector like quarks appear in many theories beyond the Standard Model as a way to cancel the mass divergence for the Higgs boson. The talk will focus on the most recent results using 13 TeV pp collision data collected by the ATLAS detector. This presentation will address the analysis techniques, in particular the selection criteria, the background modelling and the related experimental...
In this talk, we point out a novel signature of physics beyond the Standard Model which could potentially be observed both at the LHC and at future colliders. This signature, which emerges naturally within many proposed extensions of the Standard Model, results from the multiple displaced vertices associated with the successive decays of unstable, long-lived particles along the same decay...
Triggering long-lived particles (LLPs) at the first stage of the trigger system is very crucial in LLP searches to ensure that we do not miss them at the very beginning. The future High Luminosity runs of the Large Hadron Collider will have an increased number of pile-up events per bunch crossing. There will be major upgrades in hardware, firmware and software sides, like tracking at level-1...
This talk discusses new techniques to detect signatures potentially originating from long-lived particles in the CMS detector, presents recent results from such searches in CMS using the full Run-II data-set of the LHC, and discusses prospects for Run-III.
We investigate simplified models involving an inert scalar triplet and vector-like leptons that can account for the muon g−2 anomaly. These simplified scenarios are embedded in a model that features W' and Z' bosons, which are subject to stringent collider bounds. The constraints coming from the muon g−2 anomaly are put into perspective with collider bounds, as well as bounds coming from...
The semileptonic B-decay anomalies could be a gateway to new physics. Of the theories and BSM models put forward, the vector charge-2/3 $U_1$ leptoquark (LQ) seems to be the best candidate to explain the anomalies seen in the $R_{D^{(*)}}$ and $R_{K^{(*)}}$ observables. In this talk, I will explore the LHC bounds on the $U_1$ leptoquark model. I will present a list of possible scenarios with...
In this talk, we present an extension of the SM featuring vector-like leptons and uncharged scalars in the BSM sector. We show that this theory allows to accommodate for the discrepancies in both the muon and electron anomalous magnetic moments simultaneously, without explicit violation of lepton flavor universality. Moreover, the theory remains physical and predictive until the Planck scale...
While the hunt for new states beyond the standard model (SM) goes on for various well motivated theories, the leptoquarks are among the most appealing scenarios at recent times due to a series of tensions observed in B−decays. We consider two scalar leptoquarks, one being a singlet and the other a triplet under the electroweak gauge group, and respectively contributes to charged and neutral...
The recent experimental result on the muon g-2 from Fermilab has confirmed the old Brookhaven result and increased the tension with the Standard Model. We investigate the electroweak sector of supersymmetry to explain the muon g-2 anomaly. We perform a scan of the SUGRA parameter space with the help of a neural network to identify the regions consistent with the g-2 anomaly. It is shown that a...
We construct a model in which the standard model
is extended by a hidden sector with two gauge $U(1)$ bosons.
A Dirac fermion $\psi$ charged under both $U(1)$ fields
is introduced in the hidden sector which
can be a subcomponent of the dark matter in the Universe.
Stueckelberg mass terms between the two
new gauge $U(1)$ fields
and the hypercharge gauge boson mediate
the...
Various theories beyond the Standard Model predict unique signatures that are difficult to reconstruct and for which estimating the background rate is also a challenge. Signatures from displaced 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 electron or high mass stable charged...
The unique design of the LHCb detector with a flexible trigger and a precision vertex tracker, offers the possibility to search for long-lived particles with low masses and short lifetimes, in complementarity with other general-purpose detectors at the LHC.
Searches have been performed at LHCb, in fully leptonic and semi-leptonic final states. In particular, searches for long-lived particles...
We consider a neutrinophilic U(1) extension of the standard model (SM) which couples only to SM isosinglet neutral fermions, charged under the new group. The neutral fermions couple to the SM matter fields through Yukawa interactions. The neutrinos in the model get their masses from a standard inverse-seesaw mechanism while an added scalar sector is responsible for the breaking of the gauged...
Axion-like particles (ALPs) are ubiquitous in models of new physics explaining some of the most
pressing puzzles of the Standard Model. However, until relatively recently, little attention has been
paid to its interplay with flavour. In this work, we study in detail the phenomenology of ALPs
that exclusively interact with up-type quarks at the tree-level, which arise in some...
The search for beyond the Standard Model interactions of neutrinos and other light new physics species is one of the most promising experimental targets, which, in the high-energy regime, is also currently less explored. In the talk, we will discuss novel prospects for such studies that will be opened up thanks to a new far-forward physics program at the LHC to be initiated with the FASER...
We investigate the prospect of searching for new physics via the novel signature of same-sign diboson + ${E\!\!/}_{T}$ at current and future LHC. We study three new physics models: (i) natural SUSY models, (ii) type-III seesaw model and (iii) type-II seesaw/Georgi-Machacek model. In the first two class of models, this signature arises due to the presence of a singly-charged particle which has...
Universal Extra Dimension (UED) is a well-motivated and well-studied scenario. One of the main motivations is the presence of a dark matter (DM) candidate namely, the lightest level-1 Kaluza-Klein (KK) particle (LKP), in the particle spectrum of UED. The minimal version of UED (mUED) scenario is highly predictive with only two parameters namely, the radius of compactification and cut-off...
Theories Beyond the Standard Model (BSM) address the outstanding issues of the Standard Model (SM). These theories predict new particles with different spin and isospin representations within a similar mass range.We consider one such model, the Leptoquarks, well motivated by various anomalies observed in the flavour sector. These particles have integral spins, 0 or 1, and belong to either of...
The type-II see-saw mechanism based on the annexation of the Standard Model by weak gauge triplet of scalar field proffers a natural explanation for the very minuteness of neutrino masses. Noting that the phenomenology for the degenerate triplet Higgs spectrum is substantially contrasting than that for the non-degenerate one, we perform a comprehensive study for a wide range of the model...
The Higgs boson may well be a composite scalar with a finite extension in space. Owing to the momentum dependence of its couplings the imprints of such a composite pseudo Goldstone Higgs may show up in the tails of various kinematic distributions at the LHC, distinguishing it from an elementary state. From the bottom up we construct the momentum dependent form factors to capture the...
The ability to identify jets stemming from the hadronisation of b-quarks (b-jets) is crucial for the physics program of ATLAS. The higher pileup conditions and the growing interest for measurements including c-jets and for searches in the high transverse momentum regime make the task more and more complex. The algorithms responsible for establishing the jet’s flavour are evolving quickly,...
We consider a classically conformal $U(1)$ extension of the Standard Model (SM).
The $U(1)$ symmetry is radiatively broken by the Coleman-Weinberg mechanism, after which the $U(1)$ Higgs field $\phi$ drives electroweak symmetry breaking through a mixed quartic coupling with the SM Higgs doublet with coupling constant $\lambda_{mix}$.
We calculate the Higgs triple couplings in this system and...
Though collider searches are constraining supersymmetric parameter space, generic model independent bounds on sneutrinos remain very low. We calculate new model independent lower bounds on general supersymmetric scenarios with sneutrino LSP and NLSPs. By recasting ATLAS LHC exotic searches in mono boson channels, we place an upper bound on the cross section on...
If the dark sector contains multiple components with similar quantum numbers which only communicate with the visible sector through a mediator, this mediator necessarily gives rise to dark-sector decays, with heavier dark components decaying to lighter components. Such successive decays can even give rise to relatively long dark decay chains with visible matter being produced at each step. In...
Confining hidden sectors are an attractive possibility for physics beyond the Standard Model (SM). They are especially motivated by neutral naturalness theories, which reconcile the lightness of the Higgs with the strong constraints on colored top partners. We study hidden QCD with one light quark flavor, coupled to the SM via effective operators suppressed by the mass of new...
Many new physics models, e.g., compositeness, extra dimensions, excited quarks, and dark matter mediators, are expected to manifest themselves in final states with 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.
We study the observability of new interactions which modify Higgs-pair production via vector-boson fusion processes at the LHC and at future proton-proton colliders. In an effective-Lagrangian approach, we explore in particular the effect of the operator $h^2 W_{\mu\nu}^a W^{a,\mu\nu}$, which describes the interaction of the Higgs boson with transverse vector-boson polarization modes. By...
Many new-physics signatures at the LHC produce highly boosted particles, leading to close-by objects in the detector and necessitating jet substructure techniques to disentangle the hadronic decay products. This talk will illustrate the use of these techniques in recent ATLAS searches for heavy W’ and Z’ resonances in top-bottom and di-top final states, as well as searches for vector-like...
We present results of searches for vector-like quarks using proton-proton collision data collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV. Single and pair production of vector-like quarks are studied, with decays into a variety of final states, containing top and bottom quarks, electroweak gauge and Higgs bosons. The presented searches make use of a wide...
Many theories beyond the Standard Model predict new phenomena, such as Z’, W’ bosons, or heavy leptons, in final states with isolated, high-pt leptons (e/mu/tau). 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 asymmetry in events with...
Searches for electroweakinos light enough to be produced at the LHC are well motivated by consideration on dark matter, naturalness and the recently observed muon g-2 anomaly. This talk presents a search for electroweakinos in fully-hadronic final states to exploit the advantage of the large branching ratio, and the efficient background rejection by identifying the high-pT bosons using...
