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First Measurement of the Ratio of Central-Electron to Forward-Electron W Partial Cross Sections in p-pbar Collisions at sqrt{s} = 1.96 TeV

ArXiv hep-ex/0702037 (2007)

Collisional relaxation of Feshbach molecules and three-body recombination in Rb87 Bose-Einstein condensates

Physical Review A Atomic Molecular and Optical Physics 75:2 (2007)

Authors:

G Smirne, RM Godun, D Cassettari, V Boyer, CJ Foot, T Volz, N Syassen, S Dürr, G Rempe, MD Lee, K Góral, T Köhler

Abstract:

We predict the resonance-enhanced magnetic field dependence of atom-dimer relaxation and three-body recombination rates in a Rb87 Bose-Einstein condensate close to 1007 G. Our exact treatments of three-particle scattering explicitly include the dependence of the interactions on the atomic Zeeman levels. The Feshbach resonance distorts the entire diatomic energy spectrum, causing interferences in both loss phenomena. Our two independent experiments confirm the predicted recombination loss over a range of rate constants that spans four orders of magnitude. © 2007 The American Physical Society.

Search for New Physics in Lepton + Photon + X Events with 929 pb-1 of ppbar Collisions at roots = 1.96 TeV

ArXiv hep-ex/0702029 (2007)

Observation of WZ Production

ArXiv hep-ex/0702027 (2007)

Search for V+A current in top-quark decays in pp̄ collisions at s=1.96TeV

Physical Review Letters 98:7 (2007)

Authors:

A Abulencia, J Adelman, T Affolder, T Akimoto, MG Albrow, D Ambrose, S Amerio, D Amidei, A Anastassov, K Anikeev, A Annovi, J Antos, M Aoki, G Apollinari, JF Arguin, T Arisawa, A Artikov, W Ashmanskas, A Attal, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, F Bedeschi, S Behari, S Belforte, G Bellettini, J Bellinger, A Belloni, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, A Boveia, B Brau, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, S Budroni, K Burkett, G Busetto, P Bussey, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, S Carillo, D Carlsmith, R Carosi, S Carron, M Casarsa, A Castro, P Catastini, D Cauz, M Cavalli-Sforza, A Cerri, L Cerrito, SH Chang, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, I Cho, K Cho, D Chokheli, JP Chou, G Choudalakis, SH Chuang, K Chung, WH Chung, YS Chung, M Ciljak, CI Ciobanu, MA Ciocci

Abstract:

We report an upper limit on the fraction of V+A current, fV+A, in top-quark decays, using approximately 700pb-1 of pp̄ collisions at s=1.96TeV acquired by the upgraded Collider Detector at Fermilab. For the decay t→Wb→ νb (where =e or μ), the invariant mass of the charged lepton and the bottom quark jet is sensitive to the polarization of the W boson. We determine fV+A=-0.06±0.25 given a top-quark mass of 175GeV/c2. We set an upper limit on fV+A of 0.29 at the 95% confidence level, an improvement by a factor of 2 on the previous best direct limit. © 2007 The American Physical Society.