@article{10902/28856,
year = {2013},
month = {4},
url = {https://hdl.handle.net/10902/28856},
abstract = {The first measurement of vector-boson production associated with a top quark-antiquark pair in proton-proton collisions at √s=7  TeV is presented. The results are based on a data set corresponding to an integrated luminosity of 5.0  fb−1, recorded by the CMS detector at the LHC in 2011. The measurement is performed in two independent channels through a trilepton analysis of t¯tZ events and a same-sign dilepton analysis of t¯tV (V=W or Z) events. In the trilepton channel a direct measurement of the t¯tZ cross section σt¯tZ=0.28+0.14−0.11 (stat)+0.06−0.03 (syst)  pb is obtained. In the dilepton channel a measurement of the t¯tV cross section yields σt¯tV=0.43+0.17−0.15 (stat)+0.09−0.07 (syst)  pb. These measurements have a significance, respectively, of 3.3 and 3.0 standard deviations from the background hypotheses and are compatible, within uncertainties, with the corresponding next-to-leading order predictions of 0.137+0.012−0.016 and 0.306+0.031−0.053  pb.},
organization = {We 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: BMWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MEYS (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); MoER, SF0690030s09,and ERDF (Estonia); Academy of Finland, MEC, 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 (Republic of Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MSI (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MON, RosAtom, RAS, and RFBR (Russia); MSTD (Serbia); SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); ThEPCenter, IPST and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA).},
publisher = {American Physical Society},
publisher = {Physical Review Letters, 2013,110(7), 172002},
title = {Measurement of associated production of vector bosons and top quark-antiquark pairs in pp collisions at sqrt(s) = 7 TeV},
author = {Chatrchyan, Serguei 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 Graziano, Alberto and Jordá Lope, Clara 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 Rodrigo Anoro, Teresa and Rodríguez Marrero, Ana Yaiza and Ruiz Jimeno, Alberto and Scodellaro, Luca and Vila Álvarez, Iván  and Vilar Cortabitarte, Rocío},
}