Precise measurement of the K±→π±e+e− decay

6533b860fe1ef96bd12c3842

RESEARCH PRODUCT

Precise measurement of the K±→π±e+e− decay

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

subject

Nuclear physics Physics Nuclear and High Energy Physics Meson Branching fraction Hadron Gamma ray Analytical chemistry CP violation Radioactive decay Lepton Dimensionless quantity

description

Abstract A sample of 7253 K ± → π ± e + e − ( γ ) decay candidates with 1.0% background contamination has been collected by the NA48/2 experiment at the CERN SPS, which allowed a precise measurement of the decay properties. The branching ratio in the full kinematic range was measured to be BR = ( 3.11 ± 0.12 ) × 10 − 7 , where the uncertainty includes also the model dependence. The shape of the form factor W ( z ) , where z = ( M e e / M K ) 2 , was parameterized according to several models, and, in particular, the slope δ of the linear form factor W ( z ) = W 0 ( 1 + δ z ) was determined to be δ = 2.32 ± 0.18 . A possible CP violating asymmetry of K + and K − decay widths was investigated, and a conservative upper limit of 2.1 × 10 − 2 at 90% CL was established.

year	journal	country	edition	language
2009-06-01	Physics Letters B

https://doi.org/10.1016/j.physletb.2009.05.040