Search for hadronic decays of W and Z bosons in photon events in pp̄ collisions at s=1.96TeV

Physical Review D - Particles, Fields, Gravitation and Cosmology 80:5 (2009)

Authors:

T Aaltonen, J Adelman, T Akimoto, MG Albrow, BA González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, M Aoki, G Apollinari, A Apresyan, T Arisawa, A Artikov, W Ashmanskas, A Attal, A Aurisano, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, PH Beauchemin, F Bedeschi, P Bednar, S Behari, G Bellettini, J Bellinger, A Belloni, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, I Bizjak, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, A Boveia, B Brau, A Bridgeman, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, A Buzatu, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, 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, K Cho, D Chokheli, JP Chou, G Choudalakis, SH Chuang, K Chung, WH Chung, YS Chung, CI Ciobanu

Abstract:

We report on a search for the process pp̄→γ+W/Z with W/Z→qq̄ in events containing two jets and a photon at the center-of-mass energy s=1.96TeV, using 184pb-1 of data collected by the CDF II detector. A neural network event selection has been developed to optimize the rejection of the large QCD production background; it is shown that this method gives a significant improvement in both signal-to-noise ratio and signal sensitivity, as compared with an event selection based on conventional cuts. An upper limit is presented for the γ+W/Z production cross section with the W and Z decaying hadronically. © 2009 The American Physical Society.

Study of the semileptonic decay Ds+→f0(980)e+ν and implications for Bs0→J/ψf0

Physical Review D - Particles, Fields, Gravitation and Cosmology 80:5 (2009)

Authors:

KM Ecklund, Q He, J Insler, H Muramatsu, CS Park, EH Thorndike, F Yang, M Artuso, S Blusk, S Khalil, R Mountain, K Randrianarivony, T Skwarnicki, S Stone, JC Wang, LM Zhang, G Bonvicini, D Cinabro, A Lincoln, MJ Smith, P Zhou, J Zhu, P Naik, J Rademacker, DM Asner, KW Edwards, J Reed, AN Robichaud, G Tatishvili, EJ White, RA Briere, H Vogel, PUE Onyisi, JL Rosner, JP Alexander, DG Cassel, R Ehrlich, L Fields, L Gibbons, SW Gray, DL Hartill, BK Heltsley, JM Hunt, DL Kreinick, VE Kuznetsov, J Ledoux, H Mahlke-Krüger, JR Patterson, D Peterson, D Riley, A Ryd, AJ Sadoff, X Shi, S Stroiney, WM Sun, J Yelton, P Rubin, N Lowrey, S Mehrabyan, M Selen, J Wiss, M Kornicer, RE Mitchell, MR Shepherd, CM Tarbert, D Besson, TK Pedlar, J Xavier, D Cronin-Hennessy, KY Gao, J Hietala, R Poling, P Zweber, S Dobbs, Z Metreveli, KK Seth, BJY Tan, A Tomaradze, S Brisbane, J Libby, L Martin, A Powell, C Thomas, G Wilkinson, H Mendez, JY Ge, DH Miller, IPJ Shipsey, B Xin, GS Adams, D Hu, B Moziak, J Napolitano

Abstract:

Using e+e-→Ds-Ds*+ and Ds*-Ds+ interactions at 4170 MeV collected with the CLEO-c detector, we investigate the semileptonic decays Ds+→f0(980)e+ν and Ds+→e+ν. By examining the decay rates as functions of the four-momentum transfer squared q2, we measure the ratio [dBdq2(Ds+→f0(980)e+ν)B(f0→π+π-)]/[dBdq2(Ds+→e+ν) B(→K+K-)] at q2 of zero to be (42±11)%. This ratio has been predicted to equal the rate ratio [B(Bs→J/ψf0)B(f0→π+π-)]/ [B(Bs→J/ψ)B(→K+K-)], thus indicating that the CP eigenstate J/ψf0 could be useful for measuring CP violation via Bs mixing. Assuming a simple pole model for the form factor |f+(q2)| in the f0e+ν decay, we find a pole mass of (1.7-0.7+4.5±0.2)GeV. We also determine the f0 mass and width as (977-9+11±1) and (91-22+30±3)MeV, respectively. In addition, we present updated results for B(Ds+→f0(980)e+ν) B(f0→π+π-)=(0.20±0.03±0.01)% and B(Ds+→e+ν)=(2. 36±0.23±0.13)%. Assuming that the f0 wave function is a combination of strange and nonstrange quark-antiquark components, we use our measurement for B(Ds+→f0(980)e+ν) to extract a value of the mixing angle that we find consistent with s̄s dominance, adding to the mystery as to why the f0 decays predominantly to two pions rather than two kaons. © 2009 The American Physical Society.

Absolute branching fraction measurements for exclusive Ds semileptonic decays

Physical Review D - Particles, Fields, Gravitation and Cosmology 80:5 (2009)

Authors:

J Yelton, P Rubin, N Lowrey, S Mehrabyan, M Selen, J Wiss, RE Mitchell, MR Shepherd, D Besson, TK Pedlar, D Cronin-Hennessy, KY Gao, J Hietala, Y Kubota, T Klein, R Poling, AW Scott, P Zweber, S Dobbs, Z Metreveli, KK Seth, BJY Tan, A Tomaradze, J Libby, L Martin, A Powell, G Wilkinson, H Mendez, JY Ge, DH Miller, V Pavlunin, B Sanghi, IPJ Shipsey, B Xin, GS Adams, D Hu, B Moziak, J Napolitano, KM Ecklund, Q He, J Insler, H Muramatsu, CS Park, EH Thorndike, F Yang, M Artuso, S Blusk, S Khalil, J Li, R Mountain, K Randrianarivony, N Sultana, T Skwarnicki, S Stone, JC Wang, LM Zhang, G Bonvicini, D Cinabro, M Dubrovin, A Lincoln, MJ Smith, P Naik, J Rademacker, DM Asner, KW Edwards, J Reed, AN Robichaud, G Tatishvili, EJ White, RA Briere, H Vogel, PUE Onyisi, JL Rosner, JP Alexander, DG Cassel, JE Duboscq, R Ehrlich, L Fields, L Gibbons, R Gray, SW Gray, DL Hartill, BK Heltsley, D Hertz, JM Hunt, J Kandaswamy, DL Kreinick, VE Kuznetsov, J Ledoux, H Mahlke-Krüger, D Mohapatra, JR Patterson, D Peterson, D Riley, A Ryd, AJ Sadoff, X Shi, S Stroiney, WM Sun, T Wilksen

Abstract:

We measure the absolute branching fractions of Ds semileptonic decays where the hadron in the final state is one of φ, η, η′, KS0, K 0, and f0, using 2.8×105 e+e-→DsDs decays collected in the CLEO-c detector at a center-of-mass energy close to 4170 MeV. We obtain B(Ds+→e+νe)=(2.29±0.37±0.11)%, B(Ds+→ηe+νe)= (2.48±0.29±0.13)%, B(Ds+→η′e+νe)=(0.91±0. 33±0.05)%, where the first uncertainties are statistical and the second are systematic. We also obtain B(Ds+→K0e+νe)=(0.37±0.10±0. 02)%, and B(Ds+→K0e+νe)=(0.18±0.07±0.01)%, which are the first measurements of Cabibbo suppressed exclusive Ds semileptonic decays, and, B(Ds+→f0e+νe)×B(f0→π+π-)=(0.13±0.04±0.01) %. This is the first absolute product branching fraction determination for a semileptonic decay including a scalar meson in the final state. © 2009 The American Physical Society.

Evidence for decays of hc to multipion final states

Physical Review D - Particles, Fields, Gravitation and Cosmology 80:5 (2009)

Authors:

GS Adams, D Hu, B Moziak, J Napolitano, KM Ecklund, Q He, J Insler, H Muramatsu, CS Park, EH Thorndike, F Yang, M Artuso, S Blusk, S Khalil, R Mountain, K Randrianarivony, T Skwarnicki, S Stone, JC Wang, LM Zhang, G Bonvicini, D Cinabro, A Lincoln, MJ Smith, P Zhou, J Zhu, P Naik, J Rademacker, DM Asner, KW Edwards, J Reed, AN Robichaud, G Tatishvili, EJ White, RA Briere, H Vogel, PUE Onyisi, JL Rosner, JP Alexander, DG Cassel, R Ehrlich, L Fields, L Gibbons, SW Gray, DL Hartill, BK Heltsley, JM Hunt, J Kandaswamy, DL Kreinick, VE Kuznetsov, J Ledoux, H Mahlke-Krüger, JR Patterson, D Peterson, D Riley, A Ryd, AJ Sadoff, X Shi, S Stroiney, WM Sun, T Wilksen, J Yelton, P Rubin, N Lowrey, S Mehrabyan, M Selen, J Wiss, M Kornicer, RE Mitchell, MR Shepherd, CM Tarbert, D Besson, TK Pedlar, J Xavier, D Cronin-Hennessy, KY Gao, J Hietala, T Klein, R Poling, P Zweber, S Dobbs, Z Metreveli, KK Seth, BJY Tan, A Tomaradze, S Brisbane, J Libby, L Martin, A Powell, C Thomas, G Wilkinson, H Mendez, JY Ge, DH Miller, IPJ Shipsey, B Xin

Abstract:

Using a sample of 2.59×107 ψ(2S) decays collected by the CLEO-c detector, we present results of a search for the decay chain ψ(2S)→π0hc, hc→n(π+π-)π0, n=1, 2, 3. We observe no significant signals for n=1 and n=3 and set upper limits for the corresponding decay rates. First evidence for the decay hc→π+π-π+π-π0 is presented, and a product branching fraction of B(ψ(2S)→hcπ0) ×B(hc→2(π+π-)π0)=1.88-0.45-0.30+0.48+0.47×10-5 is measured. This result implies that hc→hadrons and hc→γηc have comparable rates, in agreement with expectations. © 2009 The American Physical Society.

Search for anomalous production of events with a photon, jet, b-quark jet, and missing transverse energy

Physical Review D - Particles, Fields, Gravitation and Cosmology 80:5 (2009)

Authors:

T Aaltonen, J Adelman, T Akimoto, BA González, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, G Apollinari, A Apresyan, T Arisawa, A Artikov, W Ashmanskas, A Attal, A Aurisano, F Azfar, P Azzurri, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, V Bartsch, G Bauer, PH Beauchemin, F Bedeschi, D Beecher, S Behari, G Bellettini, J Bellinger, D Benjamin, A Beretvas, J Beringer, A Bhatti, M Binkley, D Bisello, I Bizjak, RE Blair, C Blocker, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, D Bortoletto, J Boudreau, A Boveia, B Brau, A Bridgeman, L Brigliadori, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, S Burke, K Burkett, G Busetto, P Bussey, A Buzatu, KL Byrum, S Cabrera, C Calancha, M Campanelli, M Campbell, F Canelli, A Canepa, B Carls, D Carlsmith, R Carosi, S Carrillo, S Carron, B Casal, M Casarsa, A Castro, P Catastini, D Cauz, V Cavaliere, M Cavalli-Sforza, A Cerri, L Cerrito, SH Chang, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, JP Chou, G Choudalakis, SH Chuang, K Chung, WH Chung, YS Chung, T Chwalek, CI Ciobanu, MA Ciocci, A Clark, D Clark

Abstract:

We present a signature-based search for the anomalous production of events containing a photon, two jets, of which at least one is identified as originating from a b quark, and missing transverse energy (E T). The search uses data corresponding to 2.0fb-1 of integrated luminosity from pp̄ collisions at a center-of-mass energy of s=1.96TeV, collected with the CDF II detector at the Fermilab Tevatron. From 6.69747×106 events with a photon candidate with transverse energy ET>25GeV, we find 617 events with E T>25GeV and two or more jets with ET>15GeV, at least one identified as originating from a b quark, versus an expectation of 607±113 events. Increasing the requirement on E T to 50 GeV, we find 28 events versus an expectation of 30±11 events. We find no indications of non-standard-model phenomena. © 2009 The American Physical Society.