Measurement of the muonic branching fractions of the narrow upsilon resonances

• Published in: Physical review letters Vol. 94; no. 1; pp. 012001.1 - 012001.5
• Main Authors: ADAMS, G. S, CHASSE, M, THORNDIKE, E. H, COAN, T. E, GAO, Y. S, LIU, F, STROYNOWSKI, R, ARTUSO, M, BOULAHOUACHE, C, BLUSK, S, BUTT, J, DAMBASUREN, E, CRAVEY, M, DORJKHAIDAV, O, MENAA, N, MOUNTAIN, R, MURAMATSU, H, NANDAKUMAR, R, REDJIMI, R, SIA, R, SKWARNICKI, T, STONE, S, WANG, J. C, CUMMINGS, J. P, ZHANG, K, CSORNA, S. E, BONVICINI, G, CINABRO, D, DUBROVIN, M, BORNHEIM, A, PAPPAS, S. P, WEINSTEIN, A. J, BRIERE, R. A, CHEN, G. P, DANKO, I, FERGUSON, T, TATISHVILI, G, VOGEL, H, WATKINS, M. E, ADAM, N. E, ALEXANDER, J. P, BERKELMAN, K, CASSEL, D. G, DUBOSCQ, J. E, ECKLUND, K. M, NAPOLITANO, J, EHRLICH, R, FIELDS, L, GALIK, R. S, GIBBONS, L, GITTELMAN, B, GRAY, R, GRAY, S. W, HARTILL, D. L, HELTSLEY, B. K, HERTZ, D, CRONIN-HENNESSY, D, PARK, C. S, PARK, W, THAYER, J. B
• Format: Journal Article
• Language: English
• Published: Ridge, NY American Physical Society 14-01-2005
• Subjects: Exact sciences and technology; Physics; Branching ratio; Resonance
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/physrevlett.94.012001

The decay branching fractions of the three narrow Upsilon resonances to mu(+)mu(-) have been measured by analyzing about 4.3 fb(-1) e(+)e(-) data collected with the CLEO III detector. The branching fraction B(Upsilon(1S)-->mu(+)mu(-))=(2.49+/-0.02+/-0.07)% is consistent with the current world average, but B(Upsilon(2S)-->mu(+)mu(-))=(2.03+/-0.03+/-0.08)% and B(Upsilon(3S)-->mu(+)mu(-))=(2.39+/-0.07+/-0.10)% are significantly larger than prior results. These new muonic branching fractions imply a narrower total decay width for the Upsilon(2S) and Upsilon(3S) resonances and lower other branching fractions that rely on these decays in their determination.