Search for heavy vector-like quarks coupling to light quarks in proton–proton collisions at s=7 TeV with the ATLAS detector

• Published in: Physics letters. B 2012-05, Vol.712 (1-2), p.22-39
• Main Authors: Addy, T.N., Alessandria, F., Anastopoulos, C., Bain, T., Bangert, A., Battaglia, A., Benhammou, Y., Benoit, M., Bensinger, J.R., Bertinelli, F., Besson, N., Blondel, A., Bohm, J., Bozhko, N.I., Buran, T., Canale, V., Cavalli-Sforza, M., Chelkov, G.A., Cinca, D., Costa, G., Dittus, F., Duchovni, E., Dudziak, F., Fanti, M., Fokitis, M., Fournier, D., Friedrich, F., Gaur, B., Gee, C.N.P., Goy, C., Grancagnolo, F., Guindon, S., Gwilliam, C.B., Hayden, D., Huang, G.S., Hubacek, Z., Hurwitz, M., Ilic, N., Jackson, B., Jain, V., Karnevskiy, M., Klein, U., Knue, A., Koi, T., Kolesnikov, V., Kono, T., Kotov, V.M., Kruchonak, U., Levitski, M.S., Liebig, W., Liu, M., Loddenkoetter, T., Loscutoff, P., Luci, C., Ma, L.L., Malon, D., Mameghani, R., Marino, C.P., Martens, F.K., Martin, B., Martin, Ph, McMahon, S.J., Miller, R.J., Miñano Moya, M., Murray, W.J., Palma, A., Perez Codina, E., Peters, K., Petersen, B.A., Petrolo, E., Plamondon, M., Polci, F., Pope, B.G., Popeneciu, G.A., Radics, B., Richter, R., Rosselet, L., Rubinskiy, I., Sandstroem, R., Saxon, J., Schlenker, S., Schneider, B., Schroeder, C., Seiden, A., Seman, M., Sinervo, P., Spurlock, B., Stumer, I., Szeless, B., Terada, S., Thun, R.P., Tuts, P.M., Vickey, T., Weber, M., White, A., Yamamoto, S., Yasu, Y., Yorita, K., Zemla, A., Zevi della Porta, G.
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Nuclear physics; Physics; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; The physics of elementary particles and fields
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2012.03.082

This Letter presents a search for singly produced vector-like quarks, Q, coupling to light quarks, q. The search is sensitive to both charged current (CC) and neutral current (NC) processes, pp→Qq→Wqq′ and pp→Qq→Zqq′ with a leptonic decay of the vector gauge boson. In 1.04 fb−1 of data taken in 2011 by the ATLAS experiment at a center-of-mass energy s=7 TeV, no evidence of such heavy vector-like quarks is observed above the expected Standard Model background. Limits on the heavy vector-like quark production cross section times branching ratio as a function of mass mQ are obtained. For a coupling κqQ=v/mQ, where v is the Higgs vacuum expectation value, 95% C.L. lower limits on the mass of a vector-like quark are set at 900 GeV and 760 GeV from CC and NC processes, respectively.