Determination of the width of the top quark

• Published in: arXiv.org 2010-09
• Main Authors: Arnoud, Y, Askew, A, Åsman, B, Bagby, L, Banerjee, S, Barberis, E, Baringer, P, Barreto, J, Bazterra, V, Beale, S, Begel, M, Bernardi, G, Bertram, I, Bhatnagar, V, Boos, E E, Brandt, O, Brock, R, Bross, A, Brown, J, Buchholz, D, Calpas, B, Carrasco-Lizarraga, M A, Castilla-Valdez, H, Chakrabarti, S, Chan, K M, Choi, S, Cooke, M, Demina, R, Dorland, T, Dubey, A, Enari, Y, Evdokimov, A, Fiedler, F, Fox, H, Gay, P, Gerber, C E, Grünewald, M W, Gutierrez, P, Haasc, A, Herner, K, Hoang, T, Iashvili, I, Illingworth, R, Joshi, J, Karmanov, D, Kermiche, S, Khanov, A, Kozelov, A V, Lammers, S, Lipton, R, Liu, Z, Lubatti, H J, Lyon, A L, Mackin, D, Malyshev, V L, Menezes, D, Mulhearn, M, Orduna, J, Osta, J, Parihar, V, Perfilov, M, Peters, Y, Petrillo, G, Podesta-Lermaf, P L M, Podstavkov, V M, Popov, A V, Quadt, A, Quinn, B, Rangel, M S, Ratoff, P N, Rich, P, Rominsky, M, Rubinov, P, Ruchti, R, Sajot, G, Scheglov, Y, Schlobohm, S, Schwienhorst, R, Shary, V, Shivpuri, R K, Simak, V, Slattery, P, Smirnov, D, Snow, J, Spurlock, B, Stoyanova, D A, Strauss, E, Strom, D, Svoisky, P, Tanasijczuk, A, van Leeuwen, W M, Varnes, E W, Vasilyev, I A, Verdier, P, Verzocchi, M, Wood, D R, Wyatt, T R, Yoo, H D, Zhao, T, Zivkovic, L
• Format: Article
• Language: English
• Subjects: Luminosity; Quarks
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1009.5686

We extract the total width of the top quark, Gamma_t, from the partial decay width Gamma(t -> W b) measured using the t-channel cross section for single top quark production and from the branching fraction B(t -> W b) measured in ttbar events using up to 2.3 fb^-1 of integrated luminosity collected by the D0 Collaboration at the Tevatron ppbar Collider. The result is Gamma_t = 1.99 +0.69 -0.55 GeV, which translates to a top-quark lifetime of tau_t = (3.3 +1.3 -0.9) x 10^-25 s. Assuming a high mass fourth generation b' quark and unitarity of the four-generation quark-mixing matrix, we set the first upper limit on |Vtb'| < 0.63 at 95% C.L.