Radiation hardness qualification of PbWO4 scintillation crystals for the CMS Electromagnetic Calorimeter

This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2010 IOPEnsuring the radiation hardness of PbWO4 crystals was one of the main priorities during the construction of the electromagnetic calorimeter of the CMS experiment at CERN. The production on an industrial scale of radiation hard crystals and their certification over a period of several years represented a difficult challenge both for CMS and for the crystal suppliers. The present article reviews the related scientific and technological problems encountered

Angular coefficients of Z bosons produced in pp collisions at s=8 TeV and decaying to ?+?? as a function of transverse momentum and rapidity

Measurements of the five most significant angular coefficients, A0 through A4, for Z bosons produced in pp collisions at s=8 TeV and decaying to ?+?? are presented as a function of the transverse momentum and rapidity of the Z boson. The integrated luminosity of the dataset collected with the CMS detector at the LHC corresponds to 19.7fb?1. These measurements provide comprehensive information about the Z boson production mechanisms, and are compared to the QCD predictions at leading order, next-to-leading order, and next-to-next-to-leading order in perturbation theoryCalifornia Earthquake Authority European Regional Development Fund Joint Institute for Nuclear Research Pakistan Atomic Energy Commission: Pakistan National Science and Technology Development Agency: Thailand Ministry of Science and Technology Fundacja na rzecz Nauki Polskiej Hispanics in Philanthropy California Department of Fish and Game Compagnia di San Paolo Qatar National Research Fund Secretaría de Estado de Investigación, Desarrollo e Innovación National Research Foundation Ministry of Science ICT and Future Planning Canadian Mathematical Society A.G. Leventis Foundation U.S. Department of Energy Academy of Finland Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Ministerio de Educación y Cultura Türkiye Atom Enerjisi Kurumu Research Promotion Foundation: Cyprus National Science Foundation Science and Technology Facilities Council Austrian Science Fund Bundesministerium für Wissenschaft, Forschung und Wirtschaft National Academy of Sciences of Ukraine Instituto Nazionale di Fisica Nucleare Department of Atomic Energy, Government of India Department of Science and Technology, Government of Rajasthan Conselho Nacional de Desenvolvimento Científico e Tecnológico ?????????? ???? ??????????????? ???????????? (????) Belgian Federal Science Policy Office Canadian Anesthesiologists' Society Alexander von Humboldt-Stiftung Departamento Administrativo de Ciencia, Tecnología e Innovación European Commission Ministerstvo Školství, Mláde?e a T?lov?chovy National Institutes of Health: Hungary CERN Serbia Erzincan Üniversitesi NSC Fonds Wetenschappelijk Onderzoek Santa Fe Institute Ministry of Education and Science Louisiana Academy of Sciences A.P. Giannini Foundation Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro State Fund for Fundamental Research of Ukraine: Ukraine CS Fund: Croatia Fuel Cell Technologies Program Bangladesh Council of Scientific and Industrial Research Ministry of Education Consejo Nacional de Ciencia y Tecnología Ministry for Business Innovation and Employment Institute for Research in Fundamental Sciences Foundation for Promotion of Material Science and Technology of Japan: Taipei College of Environmental Science and Forestry, State University of New York Human Growth Foundation Fundação de Amparo à Pesquisa do Estado de São Paulo Secretaría de Educación Pública Fonds De La Recherche Scientifique - FNRS National Natural Science Foundation of China Bundesministerium für Bildung und Forschung Hungarian Scientific Research Fund Universidade de Macau Rochester Academy of Science Agentschap voor Innovatie door Wetenschap en Technologie Ministerstvo Školství, Mláde?e a T?lov?chovy European Regional Development Fund Ministero dell’Istruzione, dell’Università e della Ricerca: 20108T4XTM General Secretariat for Research and Technology European Research CouncilWe congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC and thank the technical and administrative staffs at CERN and at other CMS institutes for their contributions to the success of the CMS effort. In addition, we gratefully acknowledge the computing centers and personnel of the Worldwide LHC Computing Grid for delivering so effectively the computing infrastructure essential to our analyses. Finally, we acknowledge the enduring support for the construction and operation of the LHC and the CMS detector provided by the following funding agencies: BMWFW and FWF (Austria); FNRS and FWO (Belgium); CNPq , CAPES , FAPERJ , and FAPESP (Brazil); MES (Bulgaria); CERN ; CAS , MOST , and NSFC (China); COLCIENCIAS (Colombia); MSES and CSF (Croatia); RPF (Cyprus); MoER , ERC IUT and ERDF (Estonia); Academy of Finland , MEC , and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF , DFG , and HGF (Germany); GSRT (Greece); OTKA and NIH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); LAS (Lithuania); MOE and UM (Malaysia); CINVESTAV , CONACYT , SEP , and UASLP-FAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON , RosAtom , RAS and RFBR (Russia); MESTD (Serbia); SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland); MST (Taipei); ThEPCenter , IPST , STAR and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU and SFFR (Ukraine); STFC (United Kingdom); DOE and NSF (USA). Individuals have received support from the Marie-Curie program and the European Research Council and EPLANET (European Union); the Leventis Foundation ; the A.P. Sloan Foundation ; the Alexander von Humboldt Foundation ; the Belgian Federal Science Policy Office ; the Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Council of Scientific and Industrial Research , India; the HOMING PLUS program of the Foundation for Polish Science , cofinanced from European Union, Regional Development Fund ; the Compagnia di San Paolo (Torino); the Consorzio per la Fisica (Trieste); MIUR project 20108T4XTM (Italy); the Thalis and Aristeia programs cofinanced by EU- ESF and the Greek NSRF ; and the National Priorities Research Program by Qatar National Research Fund

Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up

Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO