Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC

Collaboration, Cms; Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Aguilo, E.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hammer, J.; Hoch, M.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Majerotto, W.; Mikulec, I.; Pernicka, M.; Rahbaran, B.; Rohringer, C.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Szoncsó, F.; Taurok, A.; Waltenberger, W.; Walzel, G.; Widl, E.; Wulz, C. E.; Chekhovsky, V.; Emeliantchik, I.; Litomin, A.; Makarenko, V.; Mossolov, V.; Shumeiko, N.; Solin, A.; Stefanovitch, R.; Suarez Gonzalez, J.; Fedorov, A.; Korzhik, M.; Missevitch, O.; Zuyeuski, R.; Bansal, M.; Bansal, S.; Beaumont, W.; Cornelis, T.; De Wolf, E. A.; Druzhkin, D.; Janssen, X.; Luyckx, S.; Mucibello, L.; Ochesanu, S.; Roland, B.; Rougny, R.; Selvaggi, M.; Staykova, Z.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D’Hondt, J.; Devroede, O.; Gonzalez Suarez, R.; Goorens, R.; Kalogeropoulos, A.; Maes, M.; Olbrechts, A.; Tavernier, S.; Van Doninck, W.; Van Lancker, L.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Clerbaux, B.; De Lentdecker, G.; Dero, V.; Dewulf, J. P.; Gay, A. P. R.; Hreus, T.; Léonard, A.; Marage, P. E.; Mohammadi, A.; Reis, T.; Rugovac, S.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Wickens, J.; Adler, V.; Beernaert, K.; Cimmino, A.; Costantini, S.; Garcia, G.; Grunewald, M.; Klein, B.; Lellouch, J.; Marinov, A.; Mccartin, J.; Ocampo Rios, A. A.; Ryckbosch, D.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Walsh, S.; Yazgan, E.; Zaganidis, N.; Biasini, Maurizio; Bilei, G. M.; Fano', Livio; Lariccia, P.; Lucaroni, A.; Mantovani, G.; Menichelli, M.; Nappi, A.; Passeri, Daniele; Placidi, Pisana; Romeo, F.; Sahaa, A.; Santocchia, Attilio; Servoli, L.; Spiezia, A.; Taroni, S.; Valdata, M.; Ambroglini, Filippo

doi:10.1016/j.physletb.2012.08.021

Results are presented from searches for the standard model Higgs boson in proton–proton collisions at √s = 7 and 8 TeV in the Compact Muon Solenoid experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.1 fb−1 at 7 TeV and 5.3 fb−1 at 8 TeV. The search is performed in five decay modes: γγ, ZZ, W+W−, τ+τ−, and bb. An excess of events is observed above the expected background, with a local significance of 5.0 standard deviations, at a mass near 125 GeV, signalling the production of a new particle. The expected significance for a standard model Higgs boson of that mass is 5.8 standard deviations. The excess is most significant in the two decay modes with the best mass resolution, γγ and ZZ; a fit to these signals gives a mass of 125.3±0.4(stat.)±0.5(syst.) GeV. The decay to two photons indicates that the new particle is a boson with spin different from one.