Results from the Dijet Resonance Search using data from 2016 Data running with integrated luminosity 36$fb^{-1}$ will be shown, with emphasis on narrow resonances, for resonance masses above 1.6 TeV and a variety of new physics models used for the interpretation of the experimental results. The traditional method of estimating the QCD background is used, employing a parametrization for the background and an empirical fit of the data in the signal region.
{"title":"Hunting for narrow resonances in the dijet mass spectrum at CMS","authors":"M. Diamantopoulou","doi":"10.22323/1.321.0061","DOIUrl":"https://doi.org/10.22323/1.321.0061","url":null,"abstract":"Results from the Dijet Resonance Search using data from 2016 Data running with integrated luminosity 36$fb^{-1}$ will be shown, with emphasis on narrow resonances, for resonance masses above 1.6 TeV and a variety of new physics models used for the interpretation of the experimental results. The traditional method of estimating the QCD background is used, employing a parametrization for the background and an empirical fit of the data in the signal region.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122349134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During 2017, the Large Hadron Collider provided record-breaking integrated and instantaneous luminosities, resulting in huge amounts of data with the number of interactions per bunch crossing being significantly beyond design values. I discuss the track reconstruction performance with the ATLAS detector in high-multiplicity data. I also discuss the expected tracking performance in even higher multiplicity environments in future data-taking at the high-luminosity LHC.
{"title":"Track reconstruction in high-multiplicity environments with the ATLAS Detector at the LHC","authors":"L. Mijović","doi":"10.22323/1.321.0036","DOIUrl":"https://doi.org/10.22323/1.321.0036","url":null,"abstract":"During 2017, the Large Hadron Collider provided record-breaking integrated and instantaneous luminosities, resulting in huge amounts of data with the number of interactions per bunch crossing being significantly beyond design values. I discuss the track reconstruction performance with the ATLAS detector in high-multiplicity data. I also discuss the expected tracking performance in even higher multiplicity environments in future data-taking at the high-luminosity LHC.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117101812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The High Luminosity LHC (HL-LHC) will integrate 10 times more luminosity than the LHC, posing significant challenges for radiation tolerance and event pileup on detectors. As part of their HL-LHC upgrade program, the ATLAS and CMS collaborations are replacing the electronics of their calorimeters that provide higher granularity for the level-1 trigger and better measurements of the time of arrival of particles. The CMS collaboration is also designing a High Granularity Calorimeter to replace the existing endcap calorimeters. It features unprecedented transverse and longitudinal segmentation for both electromagnetic and hadronic compartments. This will facilitate particle-flow calorimetry, where the fine structure of showers can be measured and used to enhance pileup rejection and particle identification. In addition, a new dimension in the event reconstruction will be provided by thin timing detectors built between the inner trackers and the calorimeters of both ATLAS and CMS. They will measure the time of arrival of charged tracks with a resolution of $30$ to $40, textrm{ps}$ and help reducing the pileup density in space-time down to the level of the Phase 1.
{"title":"Status of ATLAS and CMS upgrades on calorimetry and timing","authors":"J. Sauvan, Cms Collaborations","doi":"10.22323/1.321.0143","DOIUrl":"https://doi.org/10.22323/1.321.0143","url":null,"abstract":"The High Luminosity LHC (HL-LHC) will integrate 10 times more luminosity than the LHC, posing significant challenges for radiation tolerance and event pileup on detectors. As part of their HL-LHC upgrade program, the ATLAS and CMS collaborations are replacing the electronics of their calorimeters that provide higher granularity for the level-1 trigger and better measurements of the time of arrival of particles. The CMS collaboration is also designing a High Granularity Calorimeter to replace the existing endcap calorimeters. It features unprecedented transverse and longitudinal segmentation for both electromagnetic and hadronic compartments. This will facilitate particle-flow calorimetry, where the fine structure of showers can be measured and used to enhance pileup rejection and particle identification. In addition, a new dimension in the event reconstruction will be provided by thin timing detectors built between the inner trackers and the calorimeters of both ATLAS and CMS. They will measure the time of arrival of charged tracks with a resolution of $30$ to $40, textrm{ps}$ and help reducing the pileup density in space-time down to the level of the Phase 1.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"31 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132532119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Leptoquarks (LQ) with couplings to the third generation of Standard Model (SM) quarks have been proposed as possible explanations of the flavour anomalies indicating the violation of lepton flavour universality (LFV). The CMS collaboration has initiated an extensive search programme for these new states in the LHC run-2 data recorded at $sqrt{s}=13$ TeV. In this article, the CMS search results in the LQ pair-production final states $tau b,tau b$, $nu t,nu t$, $nu b,nu b$, $tau t,tau t$, and $mu t,mu t$, as well as in the LQ single-production final state $tau,tau b$ are discussed. No significant deviation from the SM is observed in any of these channels. For a broad range of LQ decay modes, exclusion limits on the LQ masses are determined at 95% confidence level reaching from 1.0 TeV to 1.8 TeV.
与第三代标准模型(SM)夸克耦合的轻夸克(LQ)已被提出作为表明轻子风味普适性(LFV)被违反的风味异常的可能解释。CMS合作已经启动了一个广泛的搜索计划，在$sqrt{s}=13$ TeV记录的LHC run-2数据中寻找这些新状态。本文将讨论LQ成对生产最终状态$tau b,tau b$、$nu t,nu t$、$nu b,nu b$、$tau t,tau t$和$mu t,mu t$中的CMS搜索结果，以及LQ单个生产最终状态$tau,tau b$中的CMS搜索结果。在这些通道中没有观察到明显的SM偏差。对于大范围的LQ衰变模式，LQ质量的排除极限在95处确定% confidence level reaching from 1.0 TeV to 1.8 TeV.
{"title":"Searches for LFV with CMS: leptoquarks with couplings to quarks of the 3rd generation","authors":"J. Haller","doi":"10.22323/1.321.0271","DOIUrl":"https://doi.org/10.22323/1.321.0271","url":null,"abstract":"Leptoquarks (LQ) with couplings to the third generation of Standard Model (SM) quarks have been proposed as possible explanations of the flavour anomalies indicating the violation of lepton flavour universality (LFV). The CMS collaboration has initiated an extensive search programme for these new states in the LHC run-2 data recorded at $sqrt{s}=13$ TeV. In this article, the CMS search results in the LQ pair-production final states $tau b,tau b$, $nu t,nu t$, $nu b,nu b$, $tau t,tau t$, and $mu t,mu t$, as well as in the LQ single-production final state $tau,tau b$ are discussed. No significant deviation from the SM is observed in any of these channels. For a broad range of LQ decay modes, exclusion limits on the LQ masses are determined at 95% confidence level reaching from 1.0 TeV to 1.8 TeV.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"175 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117194385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Spectroscopy studies are an essential part of the LHCb experiment physics programme. The unique collected data samples and the excellent performance of the LHCb detector enable precision studies in the spectroscopy sector. These measurements provide tests for effective theories of the strong interaction. The latest results obtained by the LHCb experiment in the standard and exotic spectroscopy sectors are presented.
{"title":"LHCb spectroscopy results","authors":"Roberta Cardinale","doi":"10.22323/1.321.0191","DOIUrl":"https://doi.org/10.22323/1.321.0191","url":null,"abstract":"Spectroscopy studies are an essential part of the LHCb experiment physics programme. The unique collected data samples and the excellent performance of the LHCb detector enable precision studies in the spectroscopy sector. These measurements provide tests for effective theories of the strong interaction. The latest results obtained by the LHCb experiment in the standard and exotic spectroscopy sectors are presented.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129244427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recent measurements of diboson production in proton-proton collisions at the LHC, performed by the CMS Collaboration, are summarized. Studies of ZZ production, WZ and WW production at $sqrt{s} = 13$~TeV, $mathrm{WV} to ellnumathrm{q}bar{mathrm{q}}$ ($mathrm{V} = mathrm{W}^pm$ or Z, $ell = mathrm{e}$ or $mu$) at $sqrt{s} = 13$~TeV, and $mathrm{Z}gamma gamma$ and $mathrm{W}gamma gamma$ at $sqrt{s} = 8$~TeV are reported. Inclusive and differential cross section measurements and limits on anomalous triple gauge couplings are reported, as well as a measurement of the $mathrm{Z} to 4ell$ branching fraction.
{"title":"Latest results on diboson and multiboson production from the CMS experiment","authors":"J. Cuevas","doi":"10.22323/1.321.0288","DOIUrl":"https://doi.org/10.22323/1.321.0288","url":null,"abstract":"Recent measurements of diboson production in proton-proton collisions at the LHC, performed by the CMS Collaboration, are summarized. Studies of ZZ production, WZ and WW production at $sqrt{s} = 13$~TeV, $mathrm{WV} to ellnumathrm{q}bar{mathrm{q}}$ ($mathrm{V} = mathrm{W}^pm$ or Z, $ell = mathrm{e}$ or $mu$) at $sqrt{s} = 13$~TeV, and $mathrm{Z}gamma gamma$ and $mathrm{W}gamma gamma$ at $sqrt{s} = 8$~TeV are reported. Inclusive and differential cross section measurements and limits on anomalous triple gauge couplings are reported, as well as a measurement of the $mathrm{Z} to 4ell$ branching fraction.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132156312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The H $to$ ZZ $to$ 4$ell$ decay channel ($ell = e, mu$) is one of the most important channels for studies of properties of the Higgs boson since it has a large signal-to-background ratio due to the complete reconstruction of the final state decay objects and excellent lepton momentum resolution. Measurements performed using this decay channel and Run 1 data include, among others, the determination of the mass, spin-parity, and width of the new boson as well as tests for anomalous HVV couplings. This analysis presents measurements of properties of the Higgs boson in the H $to$ ZZ $to$ 4$ell$ decay channel at the $sqrt{s} = 13$ TeV using 41.8 fb$^{-1}$ of pp collision data collected with the CMS experiment at the LHC in 2017. In the previous iteration, categories have been introduced targeting sub-leading production modes of the Higgs boson such as vector boson fusion (VBF) and associated production with a vector boson (WH, ZH) or top quark pair (t$bar{textrm{t}}$H). Apart from a larger dataset used, the main improvements in this analysis are newly optimised lepton selection, featuring in particular the usage of a new multivariate discriminant for electrons, and improved categorisation, especially optimised towards the associated production with a top quark.
{"title":"Measurements of properties of the Higgs boson in the four-lepton final state at √s = 13 TeV","authors":"M. Kovac","doi":"10.22323/1.321.0067","DOIUrl":"https://doi.org/10.22323/1.321.0067","url":null,"abstract":"The H $to$ ZZ $to$ 4$ell$ decay channel ($ell = e, mu$) is one of the most important channels for studies of properties of the Higgs boson since it has a large signal-to-background ratio due to the complete reconstruction of the final state decay objects and excellent lepton momentum resolution. Measurements performed using this decay channel and Run 1 data include, among others, the determination of the mass, spin-parity, and width of the new boson as well as tests for anomalous HVV couplings. This analysis presents measurements of properties of the Higgs boson in the H $to$ ZZ $to$ 4$ell$ decay channel at the $sqrt{s} = 13$ TeV using 41.8 fb$^{-1}$ of pp collision data collected with the CMS experiment at the LHC in 2017. In the previous iteration, categories have been introduced targeting sub-leading production modes of the Higgs boson such as vector boson fusion (VBF) and associated production with a vector boson (WH, ZH) or top quark pair (t$bar{textrm{t}}$H). Apart from a larger dataset used, the main improvements in this analysis are newly optimised lepton selection, featuring in particular the usage of a new multivariate discriminant for electrons, and improved categorisation, especially optimised towards the associated production with a top quark.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128519760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The latest measurements of the vector boson fusion (VBF) and vector boson scattering (VBS) processes from the CMS experiment are presented, using 36 fb$^{-1}$ data collected in proton-proton collisions at $sqrt{s}$ = 13 TeV at the LHC. The measured total cross sections are compared to the theoretical predictions and limits are set on the presence of anomalous triple and quartic gauge couplings.
{"title":"Latest results on VBF and VBS processes from the CMS experiment","authors":"N. Chernyavskaya","doi":"10.22323/1.321.0291","DOIUrl":"https://doi.org/10.22323/1.321.0291","url":null,"abstract":"The latest measurements of the vector boson fusion (VBF) and vector boson scattering (VBS) processes from the CMS experiment are presented, using 36 fb$^{-1}$ data collected in proton-proton collisions at $sqrt{s}$ = 13 TeV at the LHC. The measured total cross sections are compared to the theoretical predictions and limits are set on the presence of anomalous triple and quartic gauge couplings.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124826039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Important analyses of the core LHCb physics program rely on calorimetry to identify photons, high-energy neutral pions and electrons. For this purpose, the LHCb calorimeter system is composed of a scintillating pad plane, a preshower detector, an electromagnetic and a hadronic sampling calorimeters. The interaction of a given particle in these detectors leaves a specific signature. This is exploited for particle identification (PID) by combining calorimeters and tracking information into multivariate classifiers. In this contribution, we focus on the identification of photons against high-energy neutral pions, electrons and hadronic backgrounds. Neutral particles reconstruction process at LHCb is succinctly explained and PID performances on Run 1 data is shown. Discrepancies with simulation predictions are then discussed, with special emphasis on the methods to correctly estimate PID cut efficiencies by means of large calibration samples of abundant beauty and charm decays to final states with photons or neutral pions. Finally, the technical aspects of the collection of these samples in Run 2 are presented.
{"title":"Particle identification of neutral particles at LHCb","authors":"B. Quintana","doi":"10.22323/1.321.0046","DOIUrl":"https://doi.org/10.22323/1.321.0046","url":null,"abstract":"Important analyses of the core LHCb physics program rely on calorimetry to identify photons, high-energy neutral pions and electrons. For this purpose, the LHCb calorimeter system is composed of a scintillating pad plane, a preshower detector, an electromagnetic and a hadronic sampling calorimeters. The interaction of a given particle in these detectors leaves a specific signature. This is exploited for particle identification (PID) by combining calorimeters and tracking information into multivariate classifiers. \u0000 \u0000In this contribution, we focus on the identification of photons against high-energy neutral pions, electrons and hadronic backgrounds. Neutral particles reconstruction process at LHCb is succinctly explained and PID performances on Run 1 data is shown. Discrepancies with simulation predictions are then discussed, with special emphasis on the methods to correctly estimate PID cut efficiencies by means of large calibration samples of abundant beauty and charm decays to final states with photons or neutral pions. Finally, the technical aspects of the collection of these samples in Run 2 are presented.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"9 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132546049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The LHCb experiment offers a complementary phase space to ATLAS and CMS to study electroweak processes, thanks to the forward acceptance and the large bandwidth of the trigger allowing low energy thresholds. For this reason electroweak measurements at LHCb can provide unique constraints to the Parton Distribution Functions. In these proceedings the latest measurements on $W$ and $Z$ bosons production performed during the LHC Run I and Run II data taking are presented.
{"title":"Recent results on electroweak boson production at LHCb","authors":"L. Sestini","doi":"10.22323/1.321.0299","DOIUrl":"https://doi.org/10.22323/1.321.0299","url":null,"abstract":"The LHCb experiment offers a complementary phase space to ATLAS and CMS to study electroweak processes, thanks to the forward acceptance and the large bandwidth of the trigger allowing low energy thresholds. For this reason electroweak measurements at LHCb can provide unique constraints to the Parton Distribution Functions. \u0000In these proceedings the latest measurements on $W$ and $Z$ bosons production performed during the LHC Run I and Run II data taking are presented.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132616739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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