Determination of the width of the top quark

• Published in: Physical review letters 2011-01, Vol.106 (2), p.022001-022001, Article 022001
• Main Authors: Abazov, V M, Abbott, B, Abolins, M, Acharya, B S, Adams, M, Adams, T, Alexeev, G D, Alkhazov, G, Alton, A, Alverson, G, Alves, G A, Ancu, L S, Aoki, M, Arnoud, Y, Arov, M, Askew, A, Åsman, B, Atramentov, O, Avila, C, BackusMayes, J, Badaud, F, Bagby, L, Baldin, B, Bandurin, D V, Banerjee, S, Barberis, E, Baringer, P, Barreto, J, Bartlett, J F, Bassler, U, Bazterra, V, Beale, S, Bean, A, Begalli, M, Begel, M, Belanger-Champagne, C, Bellantoni, L, Beri, S B, Bernardi, G, Bernhard, R, Bertram, I, Besançon, M, Beuselinck, R, Bezzubov, V A, Bhat, P C, Bhatnagar, V, Blazey, G, Blessing, S, Bloom, K, Boehnlein, A, Boline, D, Bolton, T A, Boos, E E, Borissov, G, Bose, T, Brandt, A, Brandt, O, Brock, R, Brooijmans, G, Bross, A, Brown, D, Brown, J, Bu, X B, Buchholz, D, Buehler, M, Buescher, V, Bunichev, V, Burdin, S, Burnett, T H, Buszello, C P, Calpas, B, Camacho-Pérez, E, Carrasco-Lizarraga, M A, Casey, B C K, Castilla-Valdez, H, Chakrabarti, S, Chakraborty, D, Chan, K M, Chandra, A, Chen, G, Chevalier-Théry, S, Cho, D K, Cho, S W, Choi, S, Choudhary, B, Christoudias, T, Cihangir, S, Claes, D, Clutter, J, Cooke, M, Cooper, W E, Corcoran, M, Couderc, F, Cousinou, M-C, Croc, A, Cutts, D, Ćwiok, M, Das, A, Davies, G, De, K
• Format: Article
• Language: English
• Subjects: Elementarpartikelfysik; Elementary particle physics; Fysik; High Energy Physics - Experiment; NATURAL SCIENCES; NATURVETENSKAP; Physics
• ISSN: 0031-9007; 1079-7114; 1079-7114
• DOI: 10.1103/physrevlett.106.022001

We extract the total width of the top quark, Γ(t), from the partial decay width Γ(t → Wb) measured using the t-channel cross section for single top-quark production and from the branching fraction B(t → Wb) measured in tt events using up to 2.3  fb(-1) of integrated luminosity collected by the D0 Collaboration at the Tevatron pp Collider. The result is Γ(t) = 1.99(-0.55)(+0.69)  GeV, which translates to a top-quark lifetime of τ(t) = (3.3(-0.9)(+1.3)) × 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 |V(tb')| < 0.63 at 95% C.L.