AION/Magis

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Classical and Quantum Brane Cosmology

(2000)

First Measurement of the Ratio B(t-->Wb)/B(t-->Wq) and Associated Limit on the CKM Element Vtb

ArXiv hep-ex/0012029 (2000)

Measurement of the Two-Jet Differential Cross Section in proton-antiproton Collisions at sqrt{s} = 1800 GeV

ArXiv hep-ex/0012013 (2000)

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(*)+¶ÙÌ„** 0, where ¶ÙÌ„**0 represents the sum of the DÌ„1(2420)0, DÌ„2*(2460)0, and DÌ„1(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 Ï€s- from the D*-→DÌ„0Ï€s- 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(*) +¶ÙÌ„**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϶Ä+ branching fraction. The measured Ds*+ longitudinal polarization, ΓL/Γ = (50.6±13.9±3.6)%, is consistent with the factorization prediction of 54%.