本文介绍了在大型强子对撞机CMS实验中观测WZ信号的方法。为了减少对蒙特卡罗模拟的依赖，我们使用数据驱动技术，并估计在95% C. L.时，WZ信号的5 sigma显著性可以达到小于350 pb^{-1}。对于sqrt{s} = 14 TeV。我们还概述了几种模型，将产生异常生产的WZ最终状态，灵敏度，可以实现较少的数据。
英文摘要：
In this article we describe the methods of observing WZ signal at CMS experiment at Large Hadron Collider. To reduce the dependence on Monte Carlo simulation we use data-driven techniques and estimate that 5sigma significance of WZ signal can be reached with less than 350 pb^{-1} at 95% C.L. for sqrt{s} = 14 TeV. We also overview several models that would yield anomalous production of the WZ final state, sensitivity to which can be achieved with less data.
The latest results on searches for production of two Higgs bosons with the CMS detector using the 2016 CERN LHC dataset are presented, as shown at the LHCP 2017 conference.
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.
Measurements of single boson production cross sections are presented. They are based on proton-proton collision data at 8 and 13 TeV recorded with the CMS detector at the LHC. Inclusive and differential cross sections with respect to various observables are measured in various phase spaces. These measurements are compared to perturbative QCD predictions and generally show good agreement with the prediction.
The most recent results of Standard Model physics using 8 and 13 TeV proton-proton collision data recorded by the CMS detector during the LHC Runs I and II are reviewed. This overview includes studies of several results of vector boson production in association with jets. The outlined results are compared to the corresponding theoretical predictions and no significant deviation is observed.
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.
Analyses of single top-quark production via $tW$ production, via $tZq$ production, and in the $s$-channel are presented, showing the scope of recent ATLAS and CMS analyses of $pp$ collisions produced at the LHC at $\sqrt{s}=7,8$, and ${13}\,\text{TeV}$. Cross-section values and signal significance estimates are established, confirming good agreement with the most precise available fixed-order calculations for each production mode.
Searches for production of supersymmetric partners of gluons and quarks with the CMS experiment at CERN's LHC have excluded these particles for masses up to about 2 TeV. The paper will present results and show the analysis techniques in these searches, with an emphasis on the use of razor variables for the discrimination between standard model backgrounds and signal.
The CMS experiment has measured the electroweak production of top quark in different singly production modes: t-, tW- and s-channel. Recent results on inclusive and differential cross section measurements of t-channel at 13 TeV and of the fiducial cross section at 8 TeV are shown. The search for single top quark production in s-channel at 7 and 8 TeV as well as the search for associated production of Z boson and single top are presented. All measurements are in agreement with the Standard Model prediction and no sign of new physics is observed.
Exclusive and diffractive physics measurements are important for the better understanding of the non-perturbative regime of QCD. Two recent results of the CMS experiment is presented in this paper. The total and differential cross sections of central exclusive $π^+π^-$ production are measured at 5.02 and 13 TeV in the $p_{\mathrm{T}}(π) > 0.2~$GeV/$c$ and $|η(π)| < 2.4$ kinematic region. The invariant mass distribution is fitted by the sum of a continuum and four interfering relativistic Breit-Wigner functions. In the second part of the paper the measurement of the single diffractive dijets is…
In this paper, a brief outlook on the measurements of the total and differential cross-sections of vector bosons production associated with heavy flavor quarks performed using CMS proton-proton collision data taken at center of mass energies of 7, 8, and 13 TeV is presented. Obtained results are compared with predictions of various state-of-the-art Monte-Carlo generators.
An overview of the boosted top production analyses using data collected by the ATLAS and CMS experiments at $\sqrt{s}=$ 8 TeV and 13 TeV of proton-proton collisions at the LHC is presented. These analyses use techniques for the reconstruction of boosted objects to measure the production of top quarks at high transverse momenta. The measurements are optimized for the different final states and for different ranges of the transverse momenta of the particles involved, improving on measurements with traditional objects reconstruction based on the combination of resolved objects.
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.
We present a search for single production of heavy vector-like quarks (VLQs), carried out by the CMS collaboration analyzing LHC pp collisions at 13 TeV. The vector like quark is a massive top quark partner that is searched for in a mass range between 0.7 and 1.7 TeV and a width between $<$1\% and 30\%. Single production can be dominant over pair production, depending on the mass of the new quark. The search is performed in a variety of final states including boosted topologies that can increase the sensitivity of the analysis.
The measurement of the $t\bar{t}$ inclusive production cross section $σ_{t\bar{t}}$ is crucial to probe QCD predictions, constrain new physic scenarios, proton PDFs, top quark pole mass, $α_S$ and many other parameters from the SM. The CMS Collaboration has measured this quantity in different final states and at different centre-of-mass energies, probing QCD calculations and deriving several constraints. In this document a summary of the latest results at each channel and centre-of-mass energy is presented.
Latest results from the CMS experiment at the LHC on top quark production in association with a Z boson or a photon, and the production of four top quarks, are summarized. Proton-proton collision data corresponding to an integrated luminosity of up to 138 fb$^{-1}$, collected at 13 TeV center-of-mass energy are used. Among the measured results, most precise inclusive cross sections, most stringent limits on models beyond the standard model and first differential measurements are presented. Overall, good agreement with standard model predictions is observed.
The study of the associated production of vector bosons and jets constitutes an excellent environment to check numerous QCD predictions. Total and differential cross sections of vector bosons produced in association with jets have been studied in pp collisions using CMS data. Differential distributions as a function of a broad range of kinematical observables are measured and compared with theoretical predictions. In this talk, studies of associated production of vector bosons with inclusive jets and with jets originating from heavy-flavour quarks will be summarized.
Results of searches for the Higgs boson production in association with a pair of top quarks using the proton-proton collision data collected by the CMS detector at LHC are presented. First, results of the searches at centre-of-mass energy of 13 TeV are briefly discussed. Then, the combination of results at centre-of-mass energies of 7, 8, and 13 TeV are presented, which provides an observation of the Higgs boson production in association with a pair of top quarks with a significance of 5.2 standard deviations.
A search for central exclusive production of top quark pairs ($\mathrm{t}\bar{\mathrm{t}}$) is presented using collision data collected by CMS and the CMS-TOTEM Precision Proton Spectrometer in 2017. A data-driven method to estimate the background from coincidences of inclusive events and pileup protons is described, as well as the development of a Boosted Decision Tree classifier to separate the exclusive $\mathrm{t}\bar{\mathrm{t}}$ signal from the inclusive $\mathrm{t}\bar{\mathrm{t}}$ background. The first-ever upper limits on the cross section of exclusive $\mathrm{t}\bar{\mathrm{t}}$ are…
This note presents selected measurements of W and Z boson production, carried out with the CMS experiment at the LHC, based on samples of events collected during 2015-2018 physics runs. W boson events were selected containing an isolated, energetic electron or muon, while Z boson events were selected containing a pair of isolated, energetic electrons or muons. Presented results include searches for rare decays of W bosons to pions.
The searches for Higgs boson production in association with a pair of top quarks at the Compact Muon Solenoid (CMS) experiment using data collected during proton-proton collisions at a center of mass energy of 13 TeV in 2016 are presented. The decay modes of the Higgs boson that are discussed here correspond to the $H \rightarrow ZZ^{*}$, $H \rightarrow WW^{*}$, $H \rightarrow ττ$ and $H \rightarrow γγ$ channels.
A search for new physics in central exclusive production using the missing mass technique with the CMS detector and the CMS-TOTEM precision proton spectrometer
RefDB: The Reference Database for CMS Monte Carlo Production
RefDB是CMS Monte Carlo参考数据库。它用于记录和管理物理模拟、重建和分析请求的所有细节，用于协调全球分布式区域中心的任务分配，无论是否启用网格，并跟踪其进度。RefDB也是工作流计划者联系以获取任务指令的中央数据库。它是自动和异步更新与簿记运行摘要。最后，它是数据目录的最终用户界面。
Searches in CMS for dark matter in final states with invisible particles recoiling against jets, top, W, Z, photon, and Higgs are presented. Various topologies are explored, covering several specific dark-matter production modes. The summary in a simplified-model framework of various searches for direct dark matter production with the CMS detector is discussed, highlighting sensitivities of the analyses under various assumptions of DM production.
We present the first measurement of the top quark pair production cross section at the new LHC center-of-mass energy of $\sqrt{s} = 13.6 \, \mathrm{TeV}$, using $1.20 \, \mathrm{fb}^{-1}$ of data recorded at the CMS detector. We use a new method combining dilepton and lepton+jets decay channels, constraining several experimental uncertainties in situ. A cross section of $887^{+43}_{-41}(\mathrm{stat+syst}) \pm 53 (\mathrm{lumi}) \, \mathrm{pb}$ is measured, in agreement with the standard model. This result constitutes a first validation of the new data taken by CMS in LHC Run 3.
The inclusive cross-section for tW production in proton-proton collisions at $\sqrt{s} = 13$ TeV is measured with a dataset corresponding to an integrated luminosity of 35.9 fb$^{-1}$ collected by the CMS experiment. The measurement is performed in events with one electron and one muon, and exploits kinematic differences between the signal and the dominating $t\bar{t}$ background through the use of multivariate discriminants designed to separate the two processes. The measured cross-section of $σ= 63.1 \pm 1.8~({\rm stat}) \pm 6.0~({\rm syst}) \pm 2.1~({\rm lumi})$ pb is in agreement with stan…
Recent analyses of top quark production in association with vector bosons are summarized, representing the most precise inclusive and differential cross section measurements of these processes to date. Proton-proton collision data at a center-of-mass energy of $\sqrt{s}=13$ TeV, recorded by the ATLAS and CMS detectors at the LHC are analyzed, corresponding to an integrated luminosity of up to 139 fb$^{-1}$ for each experiment. Comparisons with theory calculations are performed and overall good agreement with standard model predictions are obtained.
The results of the most recent measurements of the inclusive $\mathrm{t\bar{t}}$ cross section performed by the ATLAS and CMS experiments at the CERN LHC are summarized. These include results obtained in proton-proton collisions at different centre-of-mass energies, and the first observation of $\mathrm{t\bar{t}}$ production in proton-lead collisions. A new result at $\sqrt{s} = 13~\mathrm{TeV}$ by the CMS Collaboration is presented for the first time at this conference. In this analysis, the total cross section is determined both for a fixed top quark mass value in the simulation of $m_{\math…
Recent results from the CMS experiment on the production of multiple vector bosons in proton-proton collisions at the CERN LHC are presented. Measurements of WZ and ZZ production with fully leptonic decays, Z$(νν)γ$, and WV (V $=$ W,Z $\rightarrow q\bar{q}$) production at 8 and 13 TeV are discussed. Selected cross section measurements, unfolded differential measurements, and limits on anomalous triple gauge couplings are presented and compared with theoretical predictions.
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…
Measurements of several top-quark properties obtained from CMS data collected at various centre-of-mass energies are presented. The results include measurements of the top pair charge asymmetry, $\textrm{t}\bar{\textrm{t}}$ spin correlation, CP violation and the cross section of $\textrm{t}\bar{\textrm{t}}$ events produced in association with a W or a Z boson. The results are compared with predictions from the standard model as well as new physics models.
An overview of recent measurements of differential top quark pair production cross sections performed by the CMS experiment at the LHC is presented. Measurements at different proton-proton center-of-mass energies are available using the dilepton, lepton+jets, and all-jets decay channels of the top quark. In addition to the measurements of parton-level top quarks, many measurements at particle level in an experimental accessible phase space are now available. For these results the dependence on theoretical extrapolations is reduced. A common observation of all measurements is a softer transvers…
Soft quantum chromodynamics (QCD) measurements play an important role in fundamental QCD studies as well as in tuning of corresponding Monte Carlo generator models for a good description of experimental data. Recent results of soft QCD measurements with the CMS experiment, such as minimum bias/underlying event physics, double parton scattering and forward jet production production are presented.
