9 pages, 12 figures. Contribution to the proceedings of the 16th international conference on supersymmetry and the unification of fundamental interactions, SUSY08, Seoul, Korea, June 16-21, 2008
We discuss how the CMS and ATLAS experiments are preparing for the analysis of first LHC data with emphasis on the search for supersymmetry. We will show the importance of the understanding of detector, trigger, reconstruction and backgrounds, and we will present realistic estimates of the reach of CMS and ATLAS.
The expected SUSY discovery potential of the CMS experiment at LHC is described, both in the MSSM and in the more constrained framework of mSugra, with emphasis on inclusive searches, the MSSM Higgs sector, and one example of complete reconstruction of a SUSY decay chain.
Searches for supersymmetry (SUSY) models with a compressed mass spectrum are theoretically motivated but also pose experimental challenges. Two recent searches from the CMS Collaboration targeting leptonic final states that can originate from such models are presented. The first search investigates SUSY signatures with two opposite sign or three low momentum leptons, while the second probes the parameter space of top squark models, where the mass difference of the lightest SUSY particles is close to the mass of the top quark. Both searches are based on the full dataset collected by CMS during …
The tau identification and reconstruction algorithms developed for the LHC experiments Atlas and CMS are presented. Reconstruction methods suitable for use at High Level Trigger and off-line are described in detail
The latest results on searches for stop and sbottom squarks are presented. Searches for direct squark production in a variety of decay channels are reviewed. The results are based on 19.5/fb of LHC proton-proton collisions at sqrt = 8 TeV taken with the CMS detector.
We present recent work performed in ATLAS on techniques used to reconstruct the decays of SUSY particles at the LHC. We concentrate on strategies to be applied to the first fb-1 of LHC data.
Multiple searches for supersymmetry have been performed at the CMS experiment. Of these, inclusive searches aim to remain as sensitive as possible to the widest range of potential new physics scenarios. The results presented in this talk use the latest 19.5 fb$^{-1}$ of 8 TeV data from the 2012 LHC run. Interpretations are given within the context of Simplified Model Spectra for a variety of both hadronic and leptonic signatures.
The present understanding of the expected MSSM SUSY heavy neutral $A^0$ and $H^0$ Higgs reach at CMS is reviewed. Two Higgs decay channels are considered in this talk: $A,H$ $\to$ $ττ$ and $A,H$ $\to$ $χ_2^0 χ_2^0$. Under the assumption that neutralinos and sleptons are not too heavy, the channel $A,H$ $\to$ $χ_2^0 χ_2^0$ provides an interesting and complementary channel to the $ττ$ channel. The expected reach in the MSSM parameter space for both channels as well as their discovery potential at the CMS detector will be presented.
Natural SUSY suggests the existence of light stop quarks, accessible at the LHC, which are the focus of a dedicated CMS search program. I present two inclusive CMS searches that look for TeV scale colored sparticles in final states with jets, b-tagged jets and missing transverse energy performed using up to 19.4fb-1 of 8TeV LHC proton-proton data. No deviation from the Standard Model was observed in these searches, and the implications for this was shown for several simplified model scenarios and phenomenological MSSM.
An overview of minimum bias and underlying event studies at the LHC with the ATLAS and CMS detectors is presented. Current uncertainties in the modeling of soft pp inelastic interactions at the LHC energy scale are discussed. Triggers used to select inelastic interactions at ATLAS and CMS are described and compared. A summary of some of the ongoing minimum bias and underlying event analyses by the ATLAS and CMS collaborations is given.
A review of the main recent results on top quark production from the ATLAS and CMS experiments is presented. Results on both electroweak single top quark production and strong top pair production are presented.
In this paper we briefly discuss the estimation of uncertainties in QCD backgrounds to searches for Supersymmetry under development by the ATLAS collaboration.
The jet reconstruction and jet energy calibration strategies adopted by the CMS and ATLAS experiments are presented. Jet measurements that can be done with early data to confront QCD at the highest transverse momentum scale and search for new physics are described.
A set of measurements of top quark pair and single top quark production in association with standard model (SM) bosons performed by the CMS and ATLAS Collaborations is presented. The consistency of these results among themselves and with the SM prediction is discussed. The latest results on four top quark production are also shown.
The challenges for a discovery of new physics with 1 fb^-1 of LHC data for ATLAS and CMS are discussed. Four specific examples are chosen: a deviation of QCD jet distributions at high E_T, high-mass dilepton pairs, Higgs search in the WW decay channel, and low mass supersymmetry.
Prospects for heavy flavour studies with the CMS and ATLAS detectors are presented. Many studies are aimed for early LHC data, taking advantage of the large $b$ production cross-section. Rare decay studies as the $B_s \to μ^+μ^-$ decay have also been performed.
This article presents a review of recent results on direct top quark mass measurements performed by the ATLAS and CMS collaborations on $pp$ collisions collected during Run 2 of the LHC at $\sqrt{s}=$13 TeV.
The prospects of the ATLAS and CMS experiments at LHC for beyond standard model searches are depicted in this document. The presented studies concentrate on the search plans for supersymmetry (SUSY) and beyond in the first few years of data taking.
A brief review of the discovery potential of the ATLAS and CMS experiments to search for signals from extra dimensions in different luminosity scenarios is given.
Recent results of the searches for Supersymmetry in final states with one or two leptons at CMS are presented. Many Supersymmetry scenarios, including the Constrained Minimal Supersymmetric extension of the Standard Model (CMSSM), predict a substantial amount of events containing leptons, while the largest fraction of Standard Model background events -- which are QCD interactions -- gets strongly reduced by requiring isolated leptons. The analyzed data was taken in 2011 and corresponds to an integrated luminosity of approximately $\mathcal{L} = 1\,\text{fb}^{-1}$. The center-of-mass energy of …
These lecture notes for graduate students and young postdocs introduce the commissioning and early physics programme of the high-transverse-momentum experiments ATLAS and CMS, operating at the Large Hadron Collider (LHC) at CERN.
A summary of the sensitivity of the ATLAS and CMS experiments at the LHC to discover a Standard Model Higgs boson is presented. Some prospects for Minimal Supersymmetric Standard Model Higgs searches at LHC are also included.
Machine learning is essential in many aspects of top-quark related physics in the ATLAS and CMS Collaborations. This work aims to give a brief overview over current applications in the two collaborations as well as on-going studies for future applications. Copyright 2023 CERN for the benefit of the ATLAS and CMS Collaborations. Reproduction of this article or parts of it is allowed as specified in the CC-BY-4.0 license
This paper describes latest results on lepton (electron, muon and tau) and photon particle identification at the ATLAS and CMS experiments, with emphasis on how the particle identification can be validated and its performance determined using early LHC data.
The potential for top quark physics of the ATLAS and CMS experiments at the Large Hadron Collider is surveyed ranging from top quark "re-discovery" and its use as a calibration tool to initial and later stage measurements.
Recent results on top quark modelling and tuning are presented. In particular, the focus of this talk is on the studies on the definition and commissioning of the common Monte Carlo effort carried out by ATLAS and CMS within the LHCtopWG. An overview of current recommendations for modelling uncertainties is also presented.
Latest results on inclusive top-quark pair production cross-sections are presented using collision data collected by ATLAS and CMS experiments at the LHC. Inclusive and differential measurements of top-quark pair production cross-sections from ATLAS and CMS are presented in the resolved and boosted kinematic regions. The cross-sections are measured as a function of various kinematic observables of the top quarks, the jets and leptons of the event final state.
We present a result of a search for supersymmetry in final states with missing transverse energy and b-tagged jets. This search is performed with data collected by the CMS experiment at the LHC in pp-collisions at a center-of-mass energy of 7 TeV. Data-driven techniques used to measure the Standard Model background are demonstrated. The result is interpreted in terms of the constrained Minimal Supersymmetric Standard Model and compared to a similar search without any b-tag requirement.
Already with very first data, the ATLAS experiment should be sensitive to a SUSY signal well beyond the regions explored by the Tevatron. We present a detailed study of the ATLAS discovery reach in the parameter space for various SUSY models. The expected uncertainties on the background estimates are taken ito account.
The ATLAS and CMS detectors can be used to search for heavy long-lived particles which might signal physics beyond the Standard Model. Such new states can be distinguished from Standard Model particles by exploiting their unique signatures, ranging from multi-leptons and/or jets pro- duction anywhere within the detector volume, to minimum ionizing particles with low velocity and high momentum. Here are reviewed the strategies proposed by ATLAS and CMS to search for these signals, with particular emphasis on possible challenges to the trigger and detector operations.
Leptons will play a key role in the first measurements performed by the LHC experiments. The ATLAS and CMS detectors are now built, and early estimates of their performances have been revisited. The expected first physics signals are described: they will shed light on the level of detector understanding and allow a control of the systematics uncertainties, opening the road to new and precision physics.
Recent results on searches for third generation supersymmetry carried out by the ATLAS collaboration with 2.05 fb-1 of sqrt(s) = 7 TeV pp collisions recorded with the LHC in 2011 are reported. These analyses focus on search for gluino- and squark-mediated stau production, direct scalar bottom pair production and gluino-mediated sbottom and stop pair production.
Searches for resonances in final states with leptons and photons have always been a powerful tool for discovery in high energy physics. We present here the latest results from the ATLAS and CMS experiments, based on up to 36.1 fb$^{-1}$ of 13 TeV proton-proton collisions produced at the Large Hadron Collider. Detailed results on single lepton, dilepton, diphoton and Z$γ$ resonances are included.
The capabilities of the ATLAS, CMS and LHCb detectors to reconstruct jets at forward rapidities (|η|> 3) in p-p collisions at the CERN Large Hadron Collider are reviewed. The QCD and Higgs physics motivations for such measurements are summarised. Details are given on studies that provide information on the parton structure and evolution at small values of fractional momenta in the proton.
Recent results on heavy flavor physics using data from the ATLAS and CMS detectors are presented. The searches for new physics signatures in CP violation of B0_s - anti(B0_s) mixing and in B0_d --> K*0 mu+ mu- decays are discussed. The bottomonium and open-b production results obtained from proton-proton collisions at LHC are shown. The results are based on data samples containing mu+ mu- pairs collected with the ATLAS or CMS detectors by their corresponding muon trigger systems.
Using the data collected during Run I of LHC operation the CMS Collaboration performed multiple analyses searching for the direct electroweak production of supersymmetric particles in proton-proton collisions. Different decay modes of the gauginos and sleptons were considered, through intermediate vector bosons or Higgs bosons, or directly to leptons. A set of complementary searches were designed to target these different decays. None of these searches shows any indication for physics beyond the standard model.
Within the mSUGRA model, the observability of the decay of the next to lightest neutralino into leptons and the lightest neutralino has been studied using a full simulation of the CMS detector. The final state signature consists of two opposite sign leptons, several hard jets and missing transverse energy. The expected precision of the measurement of the dilepton mass edge is reported for 1 fb^-1 of data, including systematic and statistic uncertainties, comparing two benchmark points with different signatures.
Thanks to the excellent performances of ATLAS and CMS in triggering on muon signals and reconstructing these particles down to low transverse momentum, large samples of heavy-flavored hadrons have been collected in the 2011 LHC run at sqrt(s) = 7 TeV. The analysis of these samples has enabled both experiments to perform competitive measurements of heavy-flavor properties, such as quarkonium polarization, lifetime and CP-violation measurements, hadron spectroscopy and branching ratios of rare B decays.
We present heavy flavor measurements performed by the ATLAS and CMS Collaborations with data collected at the Large Hadron Collider. The production mechanism of heavy flavor hadrons is discussed as well as lifetime measurements and searches for the rare decay Bs->mumu. The large available statistics of about 5 fb-1 per experiment collected during the year 2011 together with the excellent detector performance allows to perform competitive heavy flavor measurements.
Selected results from searches for new physics with unconventional signatures using the ATLAS and CMS detectors are presented. Such signatures include emerging jets, heavy charged particles, displaced or delayed objects, and disappearing tracks. These signatures may arise from hidden sectors or supersymmetric models. The searches use proton-proton collision data from Run 2 of the LHC with a center-of-mass energy of 13 TeV.
Highlights are presented of current searches for supersymmetry produced in proton-proton collisions at the LHC, operating at sqrt(s)=7TeV. Searches with missing transverse energy are summarized from both the ATLAS and CMS experiments. A wide range of final states is covered, including recent searches with photons, leptons, and purely hadronic final states. Future developments are anticipated with extra focus on exclusive searches in electroweak and third-generation supersymmetry production.
The production of top quarks through single or rare production modes has become important due to the large amount of data collected by both ATLAS and CMS at the LHC. Many searches are now studying these processes either as a targeted signal or as an important source of background. This document reviews the Monte Carlo simulations used to model these processes in ATLAS and CMS, and how the modeling systematic uncertainties are estimated. Many analyses have also recently released a large variety of unfolded distributions. These distributions are shown and the modeling from various Monte Carlo ge…
We present recent measurements of the top quark mass by the ATLAS and CMS experiments in the $\mathrm{t}\overline{\mathrm{t}}$ lepton+jets, all-hadronic, and dilepton channels. In addition, we present a measurement using a topology enriched in t-channel single top events. The analyses include observables whose sensitivity to the top mass is calibrated using Monte Carlo simulation before they are utilized to extract the value of $\mathrm{m}_{\mathrm{t}}$ in data. The measurements outlined here enter into recent combinations by ATLAS and CMS that yield a sub-GeV precision on the top mass.
Selected results of searches for neutral long-lived particles with displaced and delayed jets, trackless jets and emerging jets, as well as displaced muons, obtained with data recorded at a centre-of-mass energy of 13 TeV by the ATLAS and CMS Collaborations during LHC's Run 2 are presented, as well as challenges and techniques.
The production of jets at the Large Hadron Collider (LHC) at TeV centre-of-mass energy is summarized, including results from both the ATLAS and CMS detectors. Current jet performance is described, followed by inclusive jet and multi-jet measurements in various final state configurations. Finally some results on heavy flavour and jet substructure are presented.
The production of single top quarks allows to study the interplay of top quark physics and the electroweak sector of the standard model. Deviations from predictions can be a hint for physics beyond the standard model. The t-channel is the dominant production mode for single top quarks at the LHC. This talk presents the latest measurements from the ATLAS and CMS collaborations.
The ATLAS and CMS Collaborations have performed a variety of measurements of the top quark mass, taking advantage of the abundant production of top quarks at the LHC. The most recent measurements are reported here, based on data collected at 8 and 13 TeV, with particular emphasis on the distinction between the so-called "direct" measurements and the "indirect" evaluations obtained from cross sections and differential cross sections.
Supersymmetry (SUSY) is an attractive extension of the Standard Model possibly solving many standing issues in particle physics and cosmology. The general purpose ATLAS detector at the Large Hadron Collider (LHC) is an experiment capable of discovering or excluding TeV SUSY. However discovery can only be claimed when the Standard Model backgrounds are understood and are under control. The expectations at the LHC are that Monte Carlo simulation predictions may not be sufficient to achieve this and the backgrounds will have to determined from data itself. In this note we will highlight some data…
Recent inclusive and differential cross section measurements of the associated production of top quark pairs with gauge bosons or heavy-flavor jets are reported. A search for physics beyond the standard model in the top quark sector is also presented. All measurements are based on data samples of proton-proton collisions at $\sqrt{s}=13$ TeV collected by the ATLAS and CMS experiments at the CERN LHC. No significant deviation from the standard model predictions is observed.
Top quarks are produced copiously at the LHC, and a variety of related measurements has been made in the recent years by the two collaborations ATLAS and CMS. The most recent measurements of the top quark mass by the two collaborations are reported here. The top quark mass has been measured with a relative uncertainty smaller than 0.3%, making the top quark the most accurately measured quark.
The latest results of high mass searches for new physics in a variety of final states from the CMS and ATLAS collaborations are presented. These searches are based on $\sqrt{s}=13$ TeV proton-proton collisions data at the LHC collected in the year 2016 and 2015. No excess above expectation from Standard Model processes are observed and exclusion limits are set at the 95% confidence level on various benchmark models.
Searches for direct electroweak production of charginos and neutralinos in signatures with two light leptons of the same charge and with three or more leptons including up to two hadronically decaying τ leptons are presented . The full 2016 dataset of pp collisions recorded by CMS at a center-of-mass energy of 13 TeV is used, corresponding to an integrated luminosity of 35.9 /fb. The observed event rates are in agreement with expectations from the standard model. These results probe charginos and neutralinos with masses up to values between 225 and 1150 GeV, depending on the model parameters a…
Supersymmetry (SUSY) is one of the most relevant scenarios of new physics searched by the ATLAS experiment at the CERN Large Hadron Collider. In this writeup the principal search strategies employed by ATLAS are outlined and the most recent results for analyses targeting SUSY discovery are discussed. A wide range of signatures is covered motivated by various theoretical scenarios and topologies: strong production, third-generation fermions, long-lived particles and R-parity violation, among others. The results are based on up to ~5 fb-1 of data recorded during 2010-2011 at sqrt(s) = 7 TeV cent…
Energetic primary cosmic rays entering the Earth's atmosphere generate flux of secondary particles including neutrinos. Muon neutrinos passed through the Earth and produced muons via the charged current reaction can be registered by experimental setups intended for the measurements with colliding beams. Due to large geometrical size and advanced muon detecting system such detectors as ATLAS and CMS on LHC have chance to contribute also into the neutrino physics. The estimation of possible rates of up-going muons produced by neutrinos is given.
The classic searches for supersymmetry have not given any strong indication for new physics. Therefore CMS is designing dedicated searches to target the more difficult and specific supersymmetry scenarios. This contribution present three such recent searches based on 13 TeV proton-proton collisions recorded with the CMS detector in 2016, 2017 and 2018: a search for heavy gluinos cascading via heavy next-to-lightest neutralino in final states with boosted Z bosons and missing transverse momentum; a search for compressed supersymmetry in final states with soft taus; and a search for compressed, …