Early results of the LHCf experiment and their contribution to ultra-high-energy cosmic ray physics

LHCf is an experiment dedicated to the measurement of neutral particles emitted in the very forward region of LHC collisions. The physics goal is to provide data for calibrating hadron interaction models that are used in the study of Extremely High-Energy Cosmic-Rays. The LHCf experiment acquired data from April to July 2010 during commissioning time of LHC operations at low luminosity. Production spectra of photons and neutrons emitted in the very forward region (η> 8.4) have been obtained. In this paper preliminary results of the photon spectra taken at s√ = 7TeV are reported

Search for a W ' boson decaying to a muon and a neutrino in pp collisions at √s =7 TeV

This is the Pre-Print version of the Article. The official published version can be accessed from the link below - Copyright @ 2011 ElsevierA new heavy gauge boson, W', decaying to a muon and a neutrino, is searched for in pp collisions at a centre-of-mass of 7 TeV. The data, collected with the CMS detector at the LHC, correspond to an integrated luminosity of 36 inverse picobarns. No significant excess of events above the standard model expectation is found in the transverse mass distribution of the muon-neutrino system. Masses below 1.40 TeV are excluded at the 95% confidence level for a sequential standard-model-like W'. The W' mass lower limit increases to 1.58 TeV when the present analysis is combined with the CMS result for the electron channel.This work is supported by the 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)

Search for a standard-model-like Higgs boson with a mass in the range 145 to 1000 GeV at the LHC

Open Access: This article is distributed under the terms of the Creative Commons Attribution License.-- et al.A search for a standard-model-like Higgs boson in the H → WW and H → ZZ decay channels is reported, for Higgs boson masses in the range 145 <mH < 1000 GeV. The search is based upon proton–proton collision data samples corresponding to an integrated luminosity of up to 5.1 fb−1 at √s=7 TeV and up to 5.3 fb−1 at √s=8 TeV , recorded by the CMS experiment at the LHC. The combined upper limits at 95 % confidence level on products of the cross section and branching fractions exclude a standard-model-like Higgs boson in the range 145<mH<710 GeV, thus extending the mass region excluded by CMS from 127–600 GeV up to 710 GeV.European Commission; Federal Ministry of Science, Research and Economy (Austria); National Fund for Scientific Research (Belgium); Research Foundation – Flanders; Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Brasil); Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro; Fundação de Amparo à Pesquisa do Estado de São Paulo; Bulgarian Ministry of Education and Science; Centre National de la Recherche Scientifique (France); Commissariat à l'énergie atomique et aux énergies alternatives (France); Ministry of Science and Technology of the People's Republic of China; Chinese Academy of Sciences; National Natural Science Foundation of China; Colciencias (Colombia); Croatian Ministry of Science, Education and Sport; Academy of Finland; Helsinki Institute of Physics; Bundesministerium für Bildung und Forschung (Deutschland); Deutsche Forschungsgemeinschaft; Helmholtz Association; General Secretariat of Research and Technology (Greece); Hungarian Scientific Research Fund; National Office for Research and Technology (Hungary); Department of Atomic Energy (India); Department of Science and Technology (India); Council of Science and Industrial Research (India); Institute for Research in Fundamental Sciences (Iran); Science Foundation Ireland; Istituto Nazionale di Fisica Nucleare (Italia); Korean Ministry of Education, Science and Technology; Lithuanian Academy of Sciences; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (México); Consejo Nacional de Ciencia y Tecnología (México); Secretaría de Educación Pública (México); Universidad Autónoma de San Luis Potosí; Ministry of Science and Innovation (New Zealand); Ministry of Science and Higher Education and the National Science Centre (Poland); Fundação para a Ciência e a Tecnologia (Portugal); Joint Institute for Nuclear Research (Russia); Russian Academy of Sciences; Russian Foundation for Basic Research; Ministry of Education, Science and Technological Development (Serbia); Ministerio de Ciencia e Innovación (España); Swiss Funding Agencies; Swiss National Science Foundation; National Science Council (Taiwan); The Scientific and Technological Research Council of Turkey; Turkish Atomic Energy Authority; Science and Technology Facilities Council (UK); Department of Energy (US); National Science Foundation (US); A. G. Leventis Foundation; Alfred P. Sloan Foundation; Alexander von Humboldt Foundation; Foundation for Polish Science.Peer Reviewe