A review of the discovery potential of LHC for new phenomena beyond the Standard Model (BSM) other than Supersymmetry in the early phase of running is presented. Topics covered include searches for extra dimensions in different scenarios (ADD, Randall-Sundrum, black holes ...), resonance hunting in di-lepton, di-photon and di-jet final states, searches for contact interactions, heavy stable charged particles, technicolor, etc. The strategies of the ATLAS and CMS experiments to understand the detectors and prepare them for "search" mode and the prospects for discoveries using early data are described.
Results of searches at the Tevatron for physics (non-SUSY and non-Higgs) beyond the Standard Model using 200/pb to 480/pb of data are discussed. Searches at DO and CDF for Z', Lepton-Quark compositeness, Randall-Sundrum Gravitons, Large Extra Dimensions, W', Leptoquarks and Excited Electrons are presented here.
Recent results on searches for Beyond Standard Model production of Higgs bosons in fermion decay channels are presented. The analyses are based on proton-proton collision data recorded by the CMS experiment at 7, 8, and 13 TeV centre-of-mass energies. The exclusion limits determined by the null results of the searches are interpreted in the framework of models that include extensions of the standard Higgs sector.
In this paper, we present the latest results of the searches for beyond standard model Higgs boson production at the Tevatron collider of Fermilab. Analyses have been carried out on samples of about 1-4 inverse fb of data collected by the CDF and D0 detectors. In particular, Higgs bosons in supersymmetric models and fermiophobic scenario have been investigated, and limits on production cross sections and theory parameters have been established.
This paper presents an overview of recent experimental direct searches for Higgs-boson and beyond-the-standard-model (BSM) physics shown in the plenary session at the SUSY07 conference. The results reported correspond to an integrated luminosity of up to 2 fb-1 of Run II data from $p\bar{p}$ collisions collected by the CDF and D0 experiments at the Fermilab Tevatron Collider. Searches covered include: the standard model (SM) Higgs boson (including sensitivity projections), the minimal supersymmetric extension of the standard model (MSSM), charged Higgs bosons and extended Higgs models, supersy…
At the end of 2008, the Large Hadron Collider (LHC) will come into operation and the two experiments ATLAS and CMS will start taking data from proton-proton collisions at a center-of-mass energy of \sqrt{s}=14 TeV. In preparation for the data taking period, the discovery potential for Higgs bosons beyond the Standard Model has been updated by both experiments and is reviewed here. In addition, the prospects for measuring the properties of a Higgs boson like its mass and width, its CP eigenvalues and its couplings to fermions and gauge bosons are discussed.
A review of the current experimental results on searches for Higgs bosons in models beyond the Standard Model is presented. Searches from ATLAS, CMS and LHCb use datasets from Run 1 of the LHC, including 7 and 8 TeV proton-proton collisions. Searches from CDF and D0 use the full or partial 1.96 TeV proton-anti-proton collision datasets from the Tevatron.
The CDF experiment at the Tevatron $p\bar{p}$ collider has pioneered and established the role of hadron collisions in exploring flavor physics through a broad program that is now at its full maturity. We report new results sensitive to physics beyond the standard model, obtained using the whole CDF data set; including new bounds on the \Bs\ mixing phase and the decay width difference of \Bs\ mass-eigenstates and a measurement of the difference of CP asymmetries in $K^+K^-$ and $π^+π^-$ decays of $D^0$ mesons. We also present a new measurement of the $\Bs \rightarrow D^{(*)+}_s D^{(*)-}_s$ bran…
Searches for Beyond the Standard Model Higgs processes in the context of Minimal Supersymmetric Standard Model and Next to MSSM are presented. The results are based on the first LHC run of pp collision data recorded by the ATLAS and CMS experiments at the CERN Large Hadron Collider at centre-of-mass energies of 7 and 8 TeV, corresponding to integrated luminosities of about 5 and 20 fb$^{-1}$ respectively. Current searches constrain large parts of the parameter space. No evidence for BSM Higgs is found.
A comprehensive review of the recent results on measurements of single top-quark production cross-sections at $\sqrt{s} =$ 7, 8 and 13 TeV performed by the ATLAS and CMS Collaborations is presented. The cross-section measurements include inclusive, fiducial and differential results. In addition, the latest measurements, based on angular distributions in $t$-channel single-top-quark processes, of the top-quark polarisation and $W$ boson spin observables at $\sqrt{s} =$ 8 TeV, and the analyses of the $Wtb$ vertex at $\sqrt{s} =$ 7 and 8 TeV are also discussed. All measurements are in good agreem…
The ATLAS, CMS and LHCb experiments will perform extensive searches for physics Beyond the Standard Model (BSM). The investigation of decays of beauty hadrons represents an alternative and complementary approach to the direct BSM searches. A particularly promising observable for the search of New Physics (NP) in $B-$hadron decays, is the measurement of the branching ratio of the decay $B_S\to μ^{+} μ^{-}$. This observable is sensitive to physics BSM with new scalar or pseudoscalar effective operators, such as theories involving an extended Higgs sector. Here the prospects of the ATLAS, CMS and…
The mass of the Standard Model (SM) Higgs boson was constrained by the Large Electron-Positron (LEP) collider to be above 114.4 GeV. Simple extensions of the scalar sector like adding singlets and/or doublets allow the lightest Higgs to be much lighter via a reduction in its coupling to gauge bosons. Such a light Higgs could have evaded the LEP searches but could be detected at the Large Hadron Collider (LHC) in the process pp -> h j -> tau^+ tau^- j, where j is a resolved jet. We conclude that in some Beyond the Standard Model (BSM) extensions of the scalar sector, a very light Higgs state co…
Semileptonic Flavor Changing Neutral Current decays of charmed hadrons uniquely probe the up-sector of the Standard Model. Clean null test observables, such as CP-asymmetries, lepton-universality ratios, missing energy modes, lepton flavor violating modes and angular observables can be studied in a variety of charmed meson and baryon modes. An overview of null test opportunities with rare charm decays is presented and similarities and complementarities of different modes are worked out.
The staged increase of the LHC beam energy provides a new class of interesting observables, namely ratios and double ratios of cross sections of various hard processes. The large degree of correlation of theoretical systematics in the cross section calculations at different energies leads to highly precise predictions for such ratios. We present in this letter few examples of such ratios, and discuss their possible implications, both in terms of opportunities for precision measurements and in terms of sensitivity to Beyond the Standard Model dynamics.
I present a new scheme for tagging boosted heavy flavor jets called "$μ_x$ tagging" and its application to TeV-scale physics beyond the Standard Model. Using muons from B hadron decay to define a particular combination "x" of angular information, and jet substructure variables, we identify a clean ($ε_{\mathrm{fake}}/ε_b\sim 1/100$) good efficiency ($ε_b = 14\%$) tag. I demonstrate the usefulness of this new scheme by showing the reach for discovery of leptophobic $Z^\prime\to b\bar b$ and $tH^\pm\to t t b$.
The LHC has collided protons on protons at center-of-mass energies of 7 and 8 TeV between 2010-2012, referred to as the Run I period. We review the current status of searches for new physics beyond the Standard Model at the end of Run I by the ATLAS and CMS experiments, limited to the 8 TeV search results published or submitted for publication as of the end of February 2014. We discuss some of the implications of these searches on the existence of TeV scale new physics, with a special focus on two open questions: the hierarchy problem, and the nature of dark matter. Finally, we give an outlook…
Models of Beyond the Standard Model (BSM) physics, like the Minimal Supersymmetric Standard Model (MSSM), often involve an extended Higgs sector, giving rise to extra neutral or charged Higgs bosons. The discovery reach expected from simulation studies for such additional Higgs particles is presented for the ATLAS, CMS and FP420 detectors at the LHC. Emphasis is put on production and decay modes involving heavy flavour b and tau particles, which are enhanced in large regions of BSM parameter space. The LHC experiments are indeed particularly well equipped to tackle final states containing heav…
The ATLAS detector has begun the search for new physics beyond the Standard Model (BSM) with \int L dt = ~45 pb^-1 of data collected in 2010. After no significant evidence of new physics was found in the data, limits on possible signatures have been set, many of which have already placed more stringent limits than previous measurements. These proceedings review recent limits obtained on various BSM models, including excited quarks, axigluons, contact interactions, quantum black holes, heavy gauge bosons (W', Z'), gravitons, fourth-generation quarks and leptoquarks.
We propose a data-directed paradigm (DDP) to search for new physics. Focusing on the data without using simulations, exclusive selections which exhibit significant deviations from known properties of the standard model can be identified efficiently and marked for further study. Different properties can be exploited with the DDP. Here, the paradigm is demonstrated by combining the promising potential of neural networks (NN) with the common bump-hunting approach. Using the NN, the resource-consuming tasks of background and systematic uncertainty estimation are avoided, allowing rapid testing of …
The D0 experiment has searched for phenomena beyond the standard model in top quark events. The methods and results of four analyses covering various possible deviations from the standard model behaviour are discussed. With data sets covering up to 2.1fb^-1 no deviation from the standard model expectations could be found.
Searches for Higgs bosons in different extensions of the Standard Model (SM) are presented. These include the Minimal Supersymmetric extension of the SM (MSSM), the next-to-MSSM (NMSSM), models with additional scalar singlets, doublets, or triplets, and generic searches for models with couplings modified with respect to the SM or for non-SM Higgs boson decay channels. Results are based on data collected by the ATLAS and CMS experiments in 2011 and 2012 at the LHC. No excess is found in any of the searches and thus the resulting exclusion limits are given.
This topical group focuses on searches for signals from physics Beyond the Standard Model (BSM), both from a theoretical and experimental perspective, including neutrino-related BSM and searches for BSM in other sectors using neutrino facilities.
Rare $\vert Δc \vert=\vert Δu \vert=1$ processes uniquely probe flavor in the Standard Model and beyond from the up-type quark sector. Opportunities to search for BSM physics in charm arise from the severe GIM suppression which kills SM contributions to leptonic axial-vector contributions and suppresses CP violation. Semileptonic decays of charmed hadrons offer a variety of clean null test observables, featuring new physics effects which are even enhanced by resonance contributions. In particular, angular observables in three- and self-analyzing four-body baryon decays, such as $Λ_c\to p \ell^…
This paper intends to collect available data on searches for scalar resonances at LHC. It is suggested that, in the absence of SUSY, the most compelling picture is the composite framework, with the idea that the lightest particles are composite scalars of the pseudo-Nambu-Goldstone type, emerging from a broken symmetry at a higher scale, the h(125) boson being one of them. Searches in two-photons, Z-photon, ZZ into 4 leptons, top, h and W pairs are reviewed. A recent search based on lepton tagging from a spectator W/Z is also discussed. Aside from the already well-known scalar observed by CMS …
A key research question at the Large Hadron Collider (LHC) is the test of models of new physics. Testing if a particular parameter set of such a model is excluded by LHC data is a challenge: It requires the time consuming generation of scattering events, the simulation of the detector response, the event reconstruction, cross section calculations and analysis code to test against several hundred signal regions defined by the ATLAS and CMS experiment. In the BSM-AI project we attack this challenge with a new approach. Machine learning tools are thought to predict within a fraction of a millisec…
The LHC experiments have searched for and excluded many proposed Beyond the Standard Model (BSM) theories. However, there are many scenarios where LHC has little or no sensitivity. Electron-positron colliders offers a different avenue for searches for such phenomena.In this talk, we will review the expectations for searches for number of BSM models at the International Linear Collider (ILC). We will discuss new Higgs-like scalars, indirect BSM via Standard Model Effective Field Theory (SMEFT) fits, mono-photons, and SUSY in strongly or moderately compressed models.
The direct searches for Beyond Standard Model (BSM) particles have been constraining their mass scale to the extent where it is now becoming consensual that such particles are likely to be above the energy reach of the LHC. Meanwhile, the studies of indirect probes of BSM physics, with all their diversity, have been progressing both in accurracy and in setting up observables with reduced theoretical uncertainties. The observation of flavour anomalies in $b$ hadron decays represents an important part of the program of indirect detection of BSM physics. Several benchmark analyses involving lepto…
Run 2 of the LHC offers some beautiful prospects for new physics, including flavour physics as well as more detailed studies of the Higgs boson and searches for new physics beyond the Standard Model (BSM). One of the possibilities for BSM physics is supersymmetry, and flavour physics plays various important rôles in constraining supersymmetric models.
Many theories, from Supersymmetry to models of Strong Electroweak Symmetry Breaking, look at the production of four top quarks as an interesting channel to evidentiate signals of new physics beyond the Standard Model. The production of four-top final states requires large partonic energies, above the 4mt threshold, that are available at the CERN Large Hadron Collider and will become more and more accessible with increasing energy and luminosity of the proton beams. A good theoretical control on the Standard Model background is a fundamental prerequisite for a correct interpretation of the poss…
ATLAS and CMS have performed a large number of searches for physics beyond the Standard Model (BSM). The results are typically presented in the context of Simplified Model Spectra (SMS), containing only a few new particles with fixed decay branching ratios, yielding generic upper limits on the cross section as a function of particle masses. The interpretation of these limits within realistic BSM scenarios is non-trivial and best done by automated computational tools. To this end we have developed SModelS, a public tool that can test any given BSM model with a $\mathbb{Z}_2$ symmetry by decompo…
Many models of physics beyond the Standard Model (SM) contain enhanced couplings to third generation particles. The predicted signatures include vector-like quarks and $t\bar{t}$ resonances. We present a review of non-SUSY based searches for new physics beyond the SM in final states with third-generation quarks using proton-proton collision data collected with the CMS detector at the CERN LHC. We analyze a wide range of final states, from multi-leptonic to entirely hadronic, and many results use novel analysis techniques to identify and reconstruct highly boosted final states that are created …
FCC-hh is a proposed future energy-frontier hadron collider, which goal is to provide high luminosity proton collisions at a centre-of-mass energy of 100 TeV. The FCC-hh has an extremely rich physics program ranging from standard model (SM) measurements to direct searches for physics beyond the standard model (BSM). One of the processes sensitive to new physics is flavour-changing neutral currents (FCNC) that extremely rare in the SM but have enhanced behavior in several BSM scenarios. In this report we present results of projections of FCNC searches in top quark interactions to the FCC-hh con…
Experiments searching for Heavy Neutral Leptons (HNLs) typically interpret their results within simplified models consisting of a single HNL coupled to a single lepton flavor. However, any model which aims to describe neutrino oscillations necessarily features more than one HNL, coupled to several flavors. As we show in this work, the reinterpretation of the results of experimental searches in terms of realistic models is a non-trivial task. We perform a detailed reinterpretation of the latest ATLAS search for prompt HNLs in W decays within a minimal low-scale seesaw with two HNLs. We show tha…
The recent results on various Beyond the Standard Model (BSM) Higgs boson searches performed by the DZERO experiment at the Tevatron are presented here. In particular, the Higgs bosons in supersymmetric models and fermiophobic scenario have been investigated. No significant excess over the Standard Model (SM) expectations have been observed and accordingly limits have been established on the corresponding model parameters.
This paper explores the physics reach of the High-Luminosity Large Hadron Collider (HL-LHC) for searches of new particles decaying to two jets. We discuss inclusive searches in dijets and b-jets, as well as searches in semi-inclusive events by requiring an additional lepton that increases sensitivity to different aspects of the underlying processes. We discuss the expected exclusion limits for generic models predicting new massive particles that result in resonant structures in the dijet mass. Prospects of the Higher-Energy LHC (HE-LHC) collider are also discussed. The study is based on the Py…
The Run 2 data taking period of the Large Hadron Collider (LHC) at CERN in years 2015-2018 has presented a great opportunity to search for physics beyond the standard model (BSM). It will be followed by the Run 3 period starting in 2022, and by the High-Luminosity LHC (HL-LHC) era starting in late 2020s, where the latter promises an unprecedented wealth of physics prospects due to very high expected integrated luminosity and improved detector features. The ATLAS, CMS and LHCb experiments pursued a rich physics program in Run 2, and are already assessing the physics expectations at the HL-LHC e…
This report presents recent results from studies of Beyond the Standard Model physics at the LHC. A focus is placed on heavy gauge bosons, electroweak symmetry breaking and left-right symmetry.
The search for Beyond the Standard Model (BSM) physics is one of the major tasks of the LHC, CERN. In these proceedings, I review the status of searches for Supersymmetry by the ATLAS and CMS collaborations. The efforts in both the hadronic and leptonic search channels are presented. A special focus is placed on the treatment of approximately one inverse femtobarn of early LHC data, and examples of background estimation techniques in such a dataset are given. Phenomenologically, besides "typical" mSUGRA scenarios, signatures based on prompt and non-pointing photons, as well as long-lived lepto…
In practice the asymmetry, which is defined based on the angular distribution of the final states in scattering or decay processes, can be utilized to scrutinize underlying dynamics in and/or beyond the standard model (BSM). As one of the possible BSM physics which might be discovered early at the LHC, extra neutral gauge bosons $Z^\prime$s are theoretical well motivated. Once $Z^\prime$s are discovered at the LHC, it is crucial to discriminate different $Z^\prime$s in various BSM. In principle such task can be accomplished by measuring the angular distribution of the final states which are pr…
The discovery potentials of ATLAS and CMS experiments at the Large Hadron Collider (LHC) for Supersimmetry (SUSY), Extra Dimensions (ED), new Gauge Bosons and R-Hadrons are discussed. Beyond Standard-Model (BSM) searches at LHC require a detailed understanding of the detector performance, reconstruction algorithms and triggering. Precision measurements of Standard Model (SM) processes are also mandatory to acquire the necessary knowledge of SM background. Both ATLAS and CMS efforts are hence addressed to determine the best calibration candles and to design a realistic plan for the initial peri…
Supersymmetry will be searched for in a variety of final states at the LHC. It is crucial that a robust, efficient and unbiased trigger selection for SUSY is implemented from the very early days of data taking. After a brief description of the ATLAS and the CMS trigger systems, and a more in-depth discussion of the ATLAS High-Level Trigger, a triggering strategy is outlined for early SUSY searches at the LHC.
Two related searches for phenomena beyond the standard model (BSM) are performed using events with hadronic jets and significant transverse momentum imbalance. The results are based on a sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment at the LHC in 2016-2018 and corresponding to an integrated luminosity of 137 fb$^{-1}$. The first search is inclusive, based on signal regions defined by the hadronic energy in the event, the jet multiplicity, the number of jets identified as originating from bottom quarks, and the value of the kinematic va…
Searches for supersymmetry (SUSY) are very important tasks at the Large Hadron colleder(LHC). If SUSY exists at the TeV scale, clear excess above the Standard Model (SM) background will be observed. SM background should be estimated from real data self. In this paper, we descrive the strategy for the early SUSY searches at the LHC and focus on the data-driven estimation of the SM background in the early stage of collision.
The High-Luminosity Large Hadron Collider (HL-LHC) is expected to deliver an integrated luminosity of up to 3000 fb$^{-1}$. The very high instantaneous luminosity will lead to about 200 proton-proton collisions per bunch crossing (pileup) superimposed to each event of interest, thus providing extremely challenging experimental conditions, which will be addressed by accompanying improvements in the decetors. The sensitivity to find new physics Beyond the Standard Model (BSM) is significantly improved and will allow to extend the reach for SUSY, heavy exotic resonances, vector like quarks, dark …
Supersymmetric particles that are long-lived or violate R-parity could evade many conventional searches for supersymmetry. This talk presents the latest results of searches for supersymmetry with long-lived particles or R-parity violation performed by the ATLAS and CMS collaborations using $\sim$20 fb$^{-1}$ of proton-proton collisions at center-of-mass energy of 8 TeV delivered by the LHC.
We identify two types of well-motivated, so-far experimentally unexplored LHC signatures of extended Higgs sectors: First, Higgs-to-Higgs decay signatures that involve (at least) two Beyond-the-Standard Model (BSM) neutral scalar bosons, $ϕ_i \to ϕ_j ϕ_k$. These signatures are discussed in the framework of the Two-Real-Singlet-Model (TRSM), which can furthermore exhibit cascades of Higgs-to-Higgs decays leading to multi-Higgs final states. Second, the charged Higgs boson decay to a W boson and a neutral BSM Higgs boson, which can easily become the dominant decay within the Two-Higgs-Doublet-Mo…
We present a general procedure to decompose Beyond the Standard Model (BSM) collider signatures presenting a Z2 symmetry into Simplified Model Spectrum (SMS) topologies. Our method provides a way to cast BSM predictions for the LHC in a model independent framework, which can be directly confronted with the relevant experimental constraints. Our concrete implementation currently focusses on supersymmetry searches with missing energy, for which a large variety of SMS results from ATLAS and CMS are available. As show-case examples we apply our procedure to two scans of the minimal supersymmetric …
We present a method to measure dominant Standard Model backgrounds using data containing high rapidity objects in pp collisions at the Large Hadron Collider. The method is developed for analyses of early LHC data when robustness against imperfections of background modeling and detector simulation can be a key to the discovery of new physics at LHC.
