A search for excited leptons in pp collisions at √s=7 TeV

作者：Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Eroe, J.; Fabjan, C.; Fried, M.; Fruehwirth, R.; Ghete, V. M.; Hammer, J.; Haensel, S.; Hoch, M.; Hoermann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Krammer, M.; Liko, D.; Mikulec, I.; Pernicka, M.; Rohringer, H.; Schoefbeck, R.; Strauss, J.; Taurok, A.; Teischinger, F.; Wagner, P.; Waltenberger, W.; Walzel, G.; Widl, E.; Wulz, C. -E.; Mossolov, V.; Shumeiko, N.; Gonzalez, J. Suarez

来源：Physics Letters B, 2011, 704(3): 143-162.

DOI：10.1016/j.physletb.2011.09.021

• CMS
• Physics

A search for excited leptons is carried out with the CMS detector at the LHC, using 36 pb(-1) of pp collision data recorded at root s = 7 TeV. The search is performed for associated production of a lepton and an oppositely charged excited lepton pp -> ll*, followed by the decay l* -> l gamma, resulting in the eey final state, where l = e, mu. No excess of events above the standard model expectation is observed. Interpreting the findings in the context of l* production through four-fermion contact interactions and subsequent decay via electroweak processes, first upper limits are reported for l* production at this collision energy. The exclusion region in the compositeness scale A and excited lepton mass M-l* parameter space is extended beyond previously established limits. For Lambda = M-l*, excited lepton masses are excluded below 1070 GeV/c(2) for e* and 1090 GeV/c(2) for mu* at the 95% confidence level.

• 出版日期2011-10-13
• 单位中国地震局; 东北大学; 西北大学; rutgers; Perugia; Univ Estadual Paulista; 北京大学; Los Alamos; 中央民族大学