New measurement of the K-+/- -> pi(+/-)mu(+)mu(-) decay

J. R. Batley, G. Kalmus, C. Lazzeroni, D. J. Munday, M. W. Slater, S. A. Wotton, R. Arcidiacono, G. Bocquet, N. Cabibbo, A. Ceccucci, D. Cundy, V. Falaleev, M. Fidecaro, L. Gatignon, A. Gonidec, W. Kubischta, A. Norton, A. Maier, M. Patel, A. PetersS. Balev, P. L. Frabetti, E. Goudzovski, P. Hristov, V. Kekelidze, V. Kozhuharov, L. Litov, D. Madigozhin, E. Marinova, N. Molokanova, I. Polenkevich, Yu. Potrebenikov, S. Stoynev, A. Zinchenko, E. Monnier, E. Swallow, R. Winston, P. Rubin, A. Walker, W. Baldini, A. Cotta Ramusino, P. Dalpiaz, C. Damiani, M. Fiorini, A. Gianoli, M. Martini, F. Petrucci, M. Savrie, M. Scarpa, H. Wahl, NA48 2 Collaboration

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A sample of 3120 K-+/- -> pi(+/-)mu(+)mu(-) decay candidates with (3.3 +/- 0.7)% background contamination has been collected by the NA48/2 experiment at the CERN SPS, allowing a detailed study of the decay properties. The branching ratio was measured to be BR = (9.62 +/- 0.25) x 10(-8). The form factor W(z), where z = (M-mu mu/M-K)(2), was parameterized according to several models. In particular, the slope of the linear form factor W(z) = W-0(1 + delta z) was measured to be delta = 3.11 +/- 0.57. Upper limits of 2.9 x 10(-2) and 2.3 x 10(-2) on possible charge asymmetry and forward-backward asymmetry were established at 90% CL. An upper limit BR(K-+/- -> pi(-/+)mu(+/-)mu(+/-)) < 1.1 x 10(-9) was established at 90% CL for the rate of the lepton number violating decay. (C) 2011 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)107-115
Number of pages9
JournalPhysics Letters B
Issue number2
Publication statusPublished - 28 Feb 2011

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