Charged particle tracks and track-based higher level observables are a key ingredient of the event reconstruction for the CMS experiment. In 2017, the CMS pixel detector was upgraded, promising significantly improved performance, but also requiring a concerted commissioning effort and improved algorithms to realize this potential from the start of the data taking in that year. Described are the alignment procedure and tracking algorithms used in 2017, as well as the potential tracking performance with future upgrades. Additionally, recent and future b-tagging developments and the resulting performance improvements are discussed.
{"title":"Tracking, alignment and b-tagging performance and prospects in CMS","authors":"J. Schulte","doi":"10.22323/1.321.0224","DOIUrl":"https://doi.org/10.22323/1.321.0224","url":null,"abstract":"Charged particle tracks and track-based higher level observables are a key ingredient of the event reconstruction for the CMS experiment. In 2017, the CMS pixel detector was upgraded, promising significantly improved performance, but also requiring a concerted commissioning effort and improved algorithms to realize this potential from the start of the data taking in that year. Described are the alignment procedure and tracking algorithms used in 2017, as well as the potential \u0000tracking performance with future upgrades. Additionally, recent and future b-tagging developments and the resulting performance improvements are discussed.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133306208","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}
In the next years, the LHC accelerator will be upgraded with an increase of instantaneous and integrated luminosity, so that the particle rate will drastically increase. The ATLAS goal is to cope this large particle rate and at the same time trying to conserve the high muon detection efficiency. For this purpose the current innermost stations of the Muon Spectrometer end-caps, the Small Wheels , will be replaced in the year 2019/2020 shutdown with the New Small Wheel detector for high luminosity LHC runs. The New Small Wheel will feature two new detector technologies: resistive Micromegas will be used as a precision detector while small strip Thin Gap Chambers will provide the trigger. An overview of the design, construction and assembly procedures of the Micromegas modules will be reported with particular reference to the SM1 chambers built in Italy. Results and characterizations will also be presented.
{"title":"The Micromegas detector for the upgrade of the Muon Spectrometer of the ATLAS experiment","authors":"D. Vannicola","doi":"10.22323/1.321.0081","DOIUrl":"https://doi.org/10.22323/1.321.0081","url":null,"abstract":"In the next years, the LHC accelerator will be upgraded with an increase of instantaneous and integrated luminosity, so that the particle rate will drastically increase. The ATLAS goal is to cope this large particle rate and at the same time trying to conserve the high muon detection efficiency. For this purpose the current innermost stations of the Muon Spectrometer end-caps, the Small Wheels , will be replaced in the year 2019/2020 shutdown with the New Small Wheel detector for high luminosity LHC runs. The New Small Wheel will feature two new detector technologies: resistive Micromegas will be used as a precision detector while small strip Thin Gap Chambers will provide the trigger. \u0000An overview of the design, construction and assembly procedures of the Micromegas modules will be reported with particular reference to the SM1 chambers built in Italy. Results and characterizations will also be presented.","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":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127775817","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 current state of research on high-energy heavy ion physics, including its motivations and purpose is reviewed from a theorist's perspective. Possible future directions are discussed, in particular the possibility of investigating the regime of small transverse momenta in more detail and an improved interplay between experiments and dedicated theory development.
{"title":"Physics perspectives with heavy ions in the HL-LHC phase and beyond","authors":"S. Floerchinger","doi":"10.22323/1.321.0262","DOIUrl":"https://doi.org/10.22323/1.321.0262","url":null,"abstract":"The current state of research on high-energy heavy ion physics, including its motivations and purpose is reviewed from a theorist's perspective. Possible future directions are discussed, in particular the possibility of investigating the regime of small transverse momenta in more detail and an improved interplay between experiments and dedicated theory development.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114657565","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 azimuthal anisotropies of particle yields observed in relativistic heavy-ion collisions have been traditionally considered as a strong evidence of the formation of a deconfined quark-gluon plasma produced in these collisions. However multiple recent measurements from the LHC experiments in $pp$ and $p$+Pb systems show similar features as those observed in Pb+Pb collisions, indicating the possibility of the production of such a deconfined medium in smaller collision systems. This report presents a comprehensive summary of ATLAS measurements in $pp$ collisions at 2.76, 5.02 and 13~TeV and in $p$+Pb collisions at 5.02 and 8.16 TeV. It includes measurements of two-particle hadron-hadron correlations in $Deltaphi$ and $Deltaeta$, with a template fitting procedure used to subtract the dijet contributions. Measurements of multi-particle cumulants $c_n{2-8}$ are also presented. The standard cumulant measurements confirm presence of collective phenomena in $p$+Pb collisions, but are biased by non-flow correlations and are not able to provide evidence for collectivity in $pp$ collisions. To address this, measurements from a new sub-event cumulant method that suppresses the contribution of non-flow effects are discussed. Also the first measurements of $mathrm{v}_2$ coefficient in $Z$-tagged $pp$ events and with $D^{starpm}$ mesons in the final state in $p$+Pb collisions are presented.
{"title":"New results on collectivity in small systems with ATLAS","authors":"M. Przybycien","doi":"10.22323/1.321.0213","DOIUrl":"https://doi.org/10.22323/1.321.0213","url":null,"abstract":"The azimuthal anisotropies of particle yields observed in relativistic heavy-ion collisions have been traditionally considered as a strong evidence of the formation of a deconfined quark-gluon plasma produced in these collisions. However multiple recent measurements from the LHC experiments in $pp$ and $p$+Pb systems show similar features as those observed in Pb+Pb collisions, indicating the possibility of the production of such a deconfined medium in smaller collision systems. \u0000This report presents a comprehensive summary of ATLAS measurements in $pp$ collisions at 2.76, 5.02 and 13~TeV and in $p$+Pb collisions at 5.02 and 8.16 TeV. It includes measurements of two-particle hadron-hadron correlations in $Deltaphi$ and $Deltaeta$, with a template fitting procedure used to subtract the dijet contributions. Measurements of multi-particle cumulants $c_n{2-8}$ are also presented. The standard cumulant measurements confirm presence of collective phenomena in $p$+Pb collisions, but are biased by non-flow correlations and are not able to provide evidence for collectivity in $pp$ collisions. To address this, measurements from a new sub-event cumulant method that suppresses the contribution of non-flow effects are discussed. Also the first measurements of $mathrm{v}_2$ coefficient in $Z$-tagged $pp$ events and with $D^{starpm}$ mesons in the final state in $p$+Pb collisions are presented.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125578284","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}
Various electroweak precision measurements are performed at the hadron colliders Tevatron and LHC. The main ones regard the masses of the W boson, top quark and Higgs boson, and sin 2 theta^l_eff. This talk covers the latter and also other measurements carried out using Drell--Yan decays. The results of the sin 2 theta^l_eff measurements have an accuracy of approximately twice that reached at LEP and SLD. The LEP and SLD accuracy is expected to be approached with Run 2 and Run 3 data and surpassed with high-luminosity LHC data. Other measurements reported are the differential distributions and the full set of decay angular coefficient in Drell--Yan events.
{"title":"Precision Electroweak Measurements at the LHC and Tevatron","authors":"M. Pieri, C. Atlas, LHCb collaborations","doi":"10.22323/1.321.0112","DOIUrl":"https://doi.org/10.22323/1.321.0112","url":null,"abstract":"Various electroweak precision measurements are performed at the hadron colliders Tevatron and LHC. \u0000The main ones regard the masses of the W boson, top quark and Higgs boson, and sin 2 theta^l_eff. \u0000This talk covers the latter and also other measurements carried out using Drell--Yan decays. \u0000The results of the sin 2 theta^l_eff measurements have an accuracy of approximately twice that reached at LEP and SLD. The LEP and SLD accuracy is expected to be approached with Run 2 and Run 3 data and surpassed with high-luminosity LHC data. \u0000Other measurements reported are the differential distributions and the full set of decay angular coefficient in Drell--Yan events.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115422805","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}
T. Diotalevi, D. Bonacorsi, C. Battilana, L. Guiducci
After the high-luminosity upgrade of the LHC, the muon chambers of CMS Barrel must cope with an increase in the number of interactions per bunch crossing. Therefore, new algorithmic techniques for data acquisition and processing will be necessary in preparation for such a high pile-up environment. Using Machine Learning as a technique to tackle this problem, this paper focuses in the production of models - with data obtained through Monte Carlo simulations - capable of predicting the transverse momentum of muons crossing the CMS Barrel muon chambers, comparing them with the transverse momentum ($p_T$) assigned by the current CMS Level-1 trigger system.
{"title":"Development of Machine Learning based muon trigger algorithms for the Phase2 upgrade of the CMS detector","authors":"T. Diotalevi, D. Bonacorsi, C. Battilana, L. Guiducci","doi":"10.22323/1.321.0092","DOIUrl":"https://doi.org/10.22323/1.321.0092","url":null,"abstract":"After the high-luminosity upgrade of the LHC, the muon chambers of CMS Barrel must cope with an increase in the number of interactions per bunch crossing. Therefore, new algorithmic techniques for data acquisition and processing will be necessary in preparation for such a high pile-up environment. Using Machine Learning as a technique to tackle this problem, this paper focuses in the production of models - with data obtained through Monte Carlo simulations - capable of predicting the transverse momentum of muons crossing the CMS Barrel muon chambers, comparing them with the transverse momentum ($p_T$) assigned by the current CMS Level-1 trigger system.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132963099","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}
In this contribution we review the status of inclusive jet cross sections at hadron colliders in perturbative QCD, studying in particular the renormalisation and factorisation scale dependence of the one-jet inclusive cross section at NNLO.
{"title":"Scale setting in inclusive jet production at hadron colliders","authors":"Joao Ramalho Pires","doi":"10.22323/1.321.0193","DOIUrl":"https://doi.org/10.22323/1.321.0193","url":null,"abstract":"In this contribution we review the status of inclusive jet cross sections at hadron colliders in perturbative QCD, studying in particular the renormalisation and factorisation scale dependence of the one-jet inclusive cross section at NNLO.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"36 130","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113974813","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}
We discuss the needs and plans for evolving event reconstruction and computing infrastructures of high-energy physics experiments towards the high-luminosity LHC era. Realizing the full physics potential of programs of the HL-LHC experiments will require the HEP community to address a number of challenges in the area of reconstruction algorithms, software and computing. These challenges center around a number of themes, including: complexity of event environment; enhancements in detector capabilities; changes in commodity computing technologies; legacy software; and the need for increased sensitivity in HL-LHC analyses. We summarize some of the research and development opportunities in thes areas.
{"title":"Future Evolution of Computing/Reconstruction in High Energy Physics","authors":"D. Lange","doi":"10.22323/1.321.0236","DOIUrl":"https://doi.org/10.22323/1.321.0236","url":null,"abstract":"We discuss the needs and plans for evolving event reconstruction and computing infrastructures of high-energy physics experiments towards the high-luminosity LHC era. Realizing the full physics potential of programs of the HL-LHC experiments will require the HEP community to address a number of challenges in the area of reconstruction algorithms, software and computing. These challenges center around a number of themes, including: complexity of event environment; enhancements in detector capabilities; changes in commodity computing technologies; legacy software; and the need for increased sensitivity in HL-LHC analyses. We summarize some of the research and development opportunities in thes areas.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121500189","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 the High Luminosity LHC, both ATLAS and CMS detectors will need extremely fast charged-particle tracking at the trigger level to maintain manageable trigger rates and achieve their physics goals. An overview of the upgrades planned for the the tracker sub-detectors and trigger systems is given, along with a description of the algorithms under study. Preliminary results from smaller scale demonstrator tes ts are also shown.
{"title":"Track Trigger at the High Luminosity LHC","authors":"M. Trovato","doi":"10.22323/1.321.0259","DOIUrl":"https://doi.org/10.22323/1.321.0259","url":null,"abstract":"During the High Luminosity LHC, both ATLAS and CMS detectors will need extremely fast charged-particle tracking at the trigger level to maintain manageable trigger rates and achieve their physics goals. \u0000 An overview of the upgrades planned for the the tracker sub-detectors and trigger systems is given, along with a description of the algorithms under study. Preliminary results from smaller scale demonstrator tes \u0000ts are also shown.","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":"2018-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131125355","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}
A. Gabrielli, G. Gebbia, F. Alfonsi, G. D'amen, N. Giangiacomi, Davide Soverini, G. Balbi, D. Falchieri, R. Travaglini
During the next years a great number of laboratories all around the world will be involved in the upgrading of the main experiments at CERN’s LHC (ATLAS, CMS, LHCb, ALICE). The ATLAS Bologna group, which collaborates with the Pixel Detector DAQ, in the last two years has developed a prototype of a new board named PILUP (PIxel detector high Luminosity UPgrade); this board is a candidate for the redesign of the ATLAS DAQ required for High Luminosity LHC project. The main characteristics of this board are the embedded processor (dual-core ARM) and the large communication bandwidth (up to 60 Gb/s through optical fibers). The board is hence capable of managing complex systems and data transmissions suitable to meet the performance required to reach the next High Energy Physics goals. The PILUP has already demonstrated the capability to manage the communication with the main board of the ATLAS DAQ upgrade, the FELIX, using different communication protocols (GBT and Full-Mode). This is the first result of the collaboration with the FELIX group. Moreover, its features make it adaptable to be programmed as an emulator of several devices (front end electronic or read-out chips like the new RD53a). In conclusion, the characteristics of this new board and the experience of its team of developers open many directions for the use of the PILUP.
{"title":"A PCI Express board proposed for the upgrade of the ATLAS TDAQ read-out system","authors":"A. Gabrielli, G. Gebbia, F. Alfonsi, G. D'amen, N. Giangiacomi, Davide Soverini, G. Balbi, D. Falchieri, R. Travaglini","doi":"10.22323/1.321.0076","DOIUrl":"https://doi.org/10.22323/1.321.0076","url":null,"abstract":"During the next years a great number of laboratories all around the world will be involved in the upgrading of the main experiments at CERN’s LHC (ATLAS, CMS, LHCb, ALICE). The ATLAS Bologna group, which collaborates with the Pixel Detector DAQ, in the last two years has developed a prototype of a new board named PILUP (PIxel detector high Luminosity UPgrade); this board is a candidate for the redesign of the ATLAS DAQ required for High Luminosity LHC project. The main characteristics of this board are the embedded processor (dual-core ARM) and the large communication bandwidth (up to 60 Gb/s through optical fibers). The board is hence capable of managing complex systems and data transmissions suitable to meet the performance required to reach the next High Energy Physics goals. The PILUP has already demonstrated the capability to manage the communication with the main board of the ATLAS DAQ upgrade, the FELIX, using different communication protocols (GBT and Full-Mode). This is the first result of the collaboration with the FELIX group. Moreover, its features make it adaptable to be programmed as an emulator of several devices (front end electronic or read-out chips like the new RD53a). In conclusion, the characteristics of this new board and the experience of its team of developers open many directions for the use of the PILUP.","PeriodicalId":346295,"journal":{"name":"Proceedings of Sixth Annual Conference on Large Hadron Collider Physics — PoS(LHCP2018)","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114513654","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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