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An aging study of double GEMs in Ar-CO2

IEEE Nuclear Science Symposium and Medical Imaging Conference 1 (2000)

Authors:

J Miyamoto, I Shipsey

Abstract:

An aging study was performed using double OEMs and a printed circuit readout board (PCB) with an intense X-ray source in an ultra clean Argon-CO2 gas environment. The detector was irradiated continuously for about 1000 hours without interruption until a large amount of charge was accumulated. A single-wire chamber served as a monitoring device to check the beam and ambient conditions and gas chromatography was used to ensure no hydrocarbon materials were present in the gas mixture. The detector could withstand more than 25 mC/mm2 with only a slight sign of aging and the charge accumulated is presumably sufficient to conduct large-scale and long-term experiments in intense radiation fields.

Measurement of B→Ds(*)+D*(*) branching fractions

Physical Review D Particles Fields Gravitation and Cosmology 62:11 (2000) 1-13

Authors:

S Ahmed, MS Alam, SB Athar, L Jian, L Ling, M Saleem, S Timm, F Wappler, A Anastassov, JE Duboscq, E Eckhart, KK Gan, C Gwon, T Hart, K Honscheid, D Hufnagel, H Kagan, R Kass, TK Pedlar, H Schwarthoff, JB Thayer, E Von Toerne, MM Zoeller, SJ Richichi, H Severini, P Skubic, A Undrus, S Chen, J Fast, JW Hinson, J Lee, DH Miller, EI Shibata, IPJ Shipsey, V Pavlunin, D Cronin-Hennessy, AL Lyon, EH Thorndike, CP Jessop, H Marsiske, ML Perl, V Savinov, X Zhou, TE Coan, V Fadeyev, Y Maravin, I Narsky, R Stroynowski, J Ye, T Wlodek, M Artuso, R Ayad, C Boulahouache, K Bukin, E Dambasuren, S Karamov, G Majumder, GC Moneti, R Mountain, S Schuh, T Skwarnicki, S Stone, G Viehhauser, JC Wang, A Wolf, J Wu, S Kopp, AH Mahmood, SE Csorna, I Danko, KW McLean, S Márka, Z Xu, R Godang, K Kinoshita, IC Lai, S Schrenk, G Bonvicini, D Cinabro, S McGee, LP Perera, GJ Zhou, E Lipeles, SP Pappas, M Schmidtler, A Shapiro, WM Sun, AJ Weinstein, F Würthwein, DE Jaffe, G Masek, HP Paar, EM Potter, S Prell, V Sharma, DM Asner, A Eppich, TS Hill, RJ Morrison, HN Nelson

Abstract:

This article describes improved measurements by CLEO of the B0→Ds+D*- and B0→Ds*+D*- branching fractions, and first evidence for the decay B+→Ds(*)+̄** 0, where ̄**0 represents the sum of the D̄1(2420)0, D̄2*(2460)0, and D̄1(j = 1/2)0 L = 1 charm meson states. Also reported is the first measurement of the Ds*+ polarization in the decay B0→Ds*+D*-. A partial reconstruction technique, employing only the fully reconstructed Ds+ and slow pion πs- from the D*-→D̄0πs- decay, enhances sensitivity. The observed branching fractions are B(B0→Ds+D*-) = (1.10±0.18±0.10±0.28)%, B(B0→Ds*+D*-) = (1.82±0.37±0.24 ±0.46)% , and B(B+→Ds(*) +̄**0) = (2.73±0.78±0.48±0.68)%, where the first error is statistical, the second systematic, and the third is the uncertainty in the Ds+→φ϶+ branching fraction. The measured Ds*+ longitudinal polarization, ΓL/Γ = (50.6±13.9±3.6)%, is consistent with the factorization prediction of 54%.

Measurement of sin 2β from B→J/φK s0 with the CDF detector

Physical Review D 61:7 (2000)

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, SR Amendolia, D Amidei, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, M Atac, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, G Bauer, F Bedeschi, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, S Bertolucci, B Bevensee, A Bhatti, C Bigongiari, M Binkley, D Bisello, RE Blair, C Blocker, K Bloom, B Blumenfeld, BS Blusk, A Bocci, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S van den Brink, C Bromberg, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, M Campbell, A Caner, W Carithers, J Carlson, D Carlsmith, J Cassada, A Castro, D Cauz, A Cerri, PS Chang, PT Chang, J Chapman, C Chen, YC Chen, MT Cheng, M Chertok, G Chiarelli, I Chirikov-Zorin, G Chlachidze, F Chlebana, L Christofek, ML Chu, S Cihangir, CI Ciobanu, AG Clark, M Cobal, E Cocca, A Connolly, J Conway, J Cooper, M Cordelli, J Guimaraes da Costa, D Costanzo, J Cranshaw, D Cronin-Hennessy, R Cropp, R Culbertson, D Dagenhart, F DeJongh

Abstract:

This paper reports an updated measurement of the standard model CP violation parameter sin 2β using the CDF Detector at Fermilab. The entire run I data sample of 110 pb -1 of proton-antiproton collisions at √s = 1.8 TeV is used to identify a signal sample of ∼400 B→J/φK s0 events, where J/φ→μ + μ - →μ + μ - . The flavor of the neutral B meson is identified at the time of production by combining information from three tagging algorithms: a same-side tag, a jet-charge tag, and a soft-lepton tag. A maximum likelihood fitting method is used to determine sin 2β=0.79 -0.44+0.41 (stat+syst). This value of sin 2β is consistent with the standard model prediction, based upon existing measurements, of a large positive CP-violating asymmetry in this decay mode. ©2000 The American Physical Society.

Resonant structure of τ→3 ππ 0 ν τ and τ→ωπν τ decays

Physical Review D 61:7 (2000)

Authors:

KW Edwards, R Janicek, PM Patel, AJ Sadoff, R Ammar, P Baringer, A Bean, D Besson, R Davis, S Kotov, I Kravchenko, N Kwak, X Zhao, S Anderson, VV Frolov, Y Kubota, SJ Lee, R Mahapatra, JJ O'Neill, R Poling, T Riehle, A Smith, S Ahmed, MS Alam, SB Athar, L Jian, L Ling, AH Mahmood, M Saleem, S Timm, F Wappler, A Anastassov, JE Duboscq, KK Gan, C Gwon, T Hart, K Honscheid, H Kagan, R Kass, J Lorenc, H Schwarthoff, E von Toerne, MM Zoeller, SJ Richichi, H Severini, P Skubic, A Undrus, M Bishai, S Chen, J Fast, JW Hinson, J Lee, N Menon, DH Miller, EI Shibata, IPJ Shipsey, Y Kwon, AL Lyon, EH Thorndike, CP Jessop, K Lingel, H Marsiske, ML Perl, V Savinov, D Ugolini, X Zhou, TE Coan, V Fadeyev, I Korolkov, Y Maravin, I Narsky, V Shelkov, R Stroynowski, J Ye, T Wlodek, M Artuso, R Ayad, E Dambasuren, S Kopp, G Majumder, GC Moneti, R Mountain, S Schuh, T Skwarnicki, S Stone, A Titov, G Viehhauser, JC Wang, A Wolf, J Wu, SE Csorna, KW McLean, S Marka, Z Xu, R Godang, K Kinoshita, IC Lai, P Pomianowski, S Schrenk, G Bonvicini

Abstract:

The resonant structure of the four pion final state in the decay τ→3 ππ 0 ν τ has been analyzed using 4.27 million τ + τ - pairs collected by the CLEO II experiment at the Cornell Electron Storage Ring. A partial wave analysis of the resonant structure of the τ→3 ππ 0 ν τ decay has been performed; the spectral decomposition of the four pion system is dominated by the ωπ and a 1 π final states. The mass and width of the ρ′ resonance have been extracted from a fit to the τ→ωπν τ spectral function. We have searched for second class currents in the decay τ→ωπν τ using spin-parity analysis and established an upper limit on the non-vector current contribution. © 2000 The American Physical Society.

Measurement of the decay amplitudes of B0 → J/ψK*0 and Bs0 → J/ψφ decays

Physical Review Letters 85:22 (2000) 4668-4673

Authors:

T Affolder, H Akimoto, A Akopian, MG Albrow, P Amaral, SR Amendolia, D Amidei, K Anikeev, J Antos, G Apollinari, T Arisawa, T Asakawa, W Ashmanskas, M Atac, F Azfar, P Azzi-Bacchetta, N Bacchetta, MW Bailey, S Bailey, P de Barbaro, A Barbaro-Galtieri, VE Barnes, BA Barnett, M Barone, G Bauer, F Bedeschi, S Belforte, G Bellettini, J Bellinger, D Benjamin, J Bensinger, A Beretvas, JP Berge, J Berryhill, B Bevensee, A Bhatti, M Binkley, D Bisello, RE Blair, C Blocker, K Bloom, B Blumenfeld, SR Blusk, A Bocci, A Bodek, W Bokhari, G Bolla, Y Bonushkin, D Bortoletto, J Boudreau, A Brandl, S van den Brink, C Bromberg, M Brozovic, N Bruner, E Buckley-Geer, J Budagov, HS Budd, K Burkett, G Busetto, A Byon-Wagner, KL Byrum, P Calafiura, M Campbell, W Carithers, J Carlson, D Carlsmith, J Cassada, A Castro, D Cauz, A Cerri, AW Chan, PS Chang, PT Chang, J Chapman, C Chen, YC Chen, MT Cheng, M Chertok, G Chiarelli, I Chirikov-Zorin, G Chlachidze, F Chlebana, L Christofek, ML Chu, YS Chung, CI Ciobanu, AG Clark, A Connolly, J Conway, J Cooper, M Cordelli, J Cranshaw, D Cronin-Hennessy, R Cropp, R Culbertson, D Dagenhart, F de Jongh, S dell'Agnello, M dell'Orso

Abstract:

A full angular analysis of both the B0 and Bs0 decay modes was carried out. For this analysis, the B0 → J/ψK*0 and Bs0 → J/ψφ decays were reconstructed. The obtained data were analyzed in detail.