@article{10902/28394, year = {2011}, month = {8}, url = {https://hdl.handle.net/10902/28394}, abstract = {A measurement is presented of the charged hadron multiplicity in hadronic PbPb collisions, as a function of pseudorapidity and centrality, at a collision energy of 2.76 TeV per nucleon pair. The data sample is collected using the CMS detector and a minimum-bias trigger, with the CMS solenoid off. The number of charged hadrons is measured both by counting the number of reconstructed particle hits and by forming hit doublets of pairs of layers in the pixel detector. The two methods give consistent results. The charged hadron multiplicity density, dN ch /dη|η=0, for head-on collisions is found to be 1612 ± 55, where the uncertainty is dominated by systematic effects. Comparisons of these results to previous measurements and to various models are also presented.}, organization = {We wish to congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC machine. We thank the technical and administrative staff at CERN and other CMS institutes, and acknowledge support from: FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTD (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA). Individuals have received support from the Marie-Curie programme and the European Research Council (European Union); the Leventis Foundation; the A. P. Sloan Foundation; the Alexander von Humboldt Foundation; the Associazione per lo Sviluppo Scientifico e Tecnologico del Piemonte (Italy); the Belgian Federal Science Policy Office; the Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); and the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium).}, publisher = {Springer Verlag}, publisher = {Journal of High Energy Physics, 2011, 2011(8), 141}, title = {Dependence on pseudorapidity and on centrality of charged hadron production in PbPb collisions at √ sNN=2.76 TeV}, author = {Chatrchyan, S. and Brochero Cifuentes, Javier Andrés and Cabrillo Bartolomé, José Iban and Calderón Tazón, Alicia and Chuang, S. H. and Duarte Campderros, Jorge and Felcini, Marta and Fernández García, Marcos and Gómez Gramuglio, Gervasio and González Sánchez, Francisco Javier and Jordá Lope, Clara and Lobelle Pardo, Patricia and López Virto, María Amparo and Marco de Lucas, Jesús and Marco de Lucas, Rafael José and Martínez Rivero, Celso and Matorras Weinig, Francisco and Muñoz Sánchez, Francisca Javiela and Piedra Gómez, Jonatan and Rodrigo Anoro, Teresa and Rodríguez Marrero, Ana Yaiza and Ruiz Jimeno, Alberto and Scodellaro, Luca and Sobrón Sañudo, Mar and Vila Álvarez, Iván and Vilar Cortabitarte, Rocío}, }