New measurement of the K±→π±μ+μ− decay

6533b836fe1ef96bd12a1233

RESEARCH PRODUCT

New measurement of the K±→π±μ+μ− decay

A. Gonidec G. Collazuol Milene Calvetti H. Dibon H. D. Wahl Nicola Cabibbo C. Cheshkov V. Kozhuharov Mauro Raggi M. Fidecaro M. Savrie B. Bloch-devaux B. Peyaud E. Iacopini M. Sozzi D. Coward G. Neuhofer F. Marchetto G.e. Kalmus S. A. Wotton L. Widhalm M. De Beer D.c. Cundy Massimiliano Fiorini Wood Vladimir Kekelidze Fabrizio Petrucci G. Bocquet Yu. Potrebenikov G. Marel Rainer Wanke N. Doble A. Winhart P. Rubin A. Nappi M. Pepe Simone Bifani M. Markytan M. Lenti B. Vallage M. Behler W. Kubischta E. C. Swallow C. Lazzeroni Leander Litov J.b. Cheze Evgueni Goudzovski D. J. Munday M. Holder I. Mannelli Luca Fiorini Cristina Biino M. Veltri S. Goy Lopez A. Ceccucci A. Peters Andrea Bizzeti A. Norton Roland Winston Ivan Mikulec A. I. Zinchenko A. A. Maier V. Falaleev C. Cerri E. Marinova M. Scarpa Enrico Celeghini A. Dabrowski G.m. Pierazzini T. Fonseca Martin Maulik R. Patel Mauro Piccini M. C. Petrucci L. Masetti A. Gianoli C. Damiani M. Ziolkowski Konrad Kleinknecht Manfred Jeitler S. Stoynev P. Marouelli S. Giudici B. Renk M. Valdata-nappi G. Anzivino Alan W. Walker M. Shieh S. Balev M. Martini W. Baldini P. L. Frabetti M. Wache Nicolo Cartiglia D. T. Madigozhin A. Michetti E. Mazzucato N. A. Molokanova K. Eppard Marco Clemencic C. Morales Morales Mayda Velasco I. Polenkevich Mark Slater M. Szleper E. Imbergamo F. Costantini L. Di Lella P. F. Dalpiaz S. Venditti G. Lamanna U. Moosbrugger A. Cotta Ramusino E. Monnier Lau Gatignon P. Cenci Jacqueline Batley G. Ruggiero P. Hristov J. Derre Roberta Arcidiacono R. Fantechi

subject

Physics Nuclear physics Nuclear and High Energy Physics Particle decay Antiparticle Muon Pion Meson Branching fraction Analytical chemistry Lepton Dimensionless quantity

description

Abstract A sample of 3120 K ± → π ± μ + μ − 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 ) × 10 − 8 . The form factor W ( z ) , where z = ( M μ μ / M K ) 2 , was parameterized according to several models. In particular, the slope of the linear form factor W ( z ) = W 0 ( 1 + δ z ) was measured to be δ = 3.11 ± 0.57 . Upper limits of 2.9 × 10 − 2 and 2.3 × 10 − 2 on possible charge asymmetry and forward–backward asymmetry were established at 90% CL. An upper limit BR ( K ± → π ∓ μ ± μ ± ) 1.1 × 10 − 9 was established at 90% CL for the rate of the lepton number violating decay.

year	journal	country	edition	language
2011-02-01	Physics Letters B

https://doi.org/10.1016/j.physletb.2011.01.042