First observation and branching fraction and decay parameter measurements of the weak radiative decay Xi0 -> Lambda e+ e-

6533b827fe1ef96bd12870ae

RESEARCH PRODUCT

First observation and branching fraction and decay parameter measurements of the weak radiative decay Xi0 -> Lambda e+ e-

Nadia Pastrone A. Winhart T. Fonseca Martin M. Eppard Mauro Piccini Fabrizio Petrucci G. Bocquet Yu. Potrebenikov M. Ziolkowski Leander Litov P.l. Frabetti A. Peters D.j. Munday Rainer Wanke Nicolo Cartiglia Cristina Lazzeroni Ivan Mikulec P. Debu E. Iacopini M. Valdata P. Grafström Alan W. Walker M.w. Slater V. Falaleev S. A. Wotton P. F. Dalpiaz M. Pepe E. Imbergamo E. C. Swallow A. Dabrowski M. Veltri M. C. Petrucci J. R. Batley R. Fantechi S. Goy Lopez G. Ruggiero N. Doble J.b. Cheze A. Norton Roland Winston M. Patel Milene Calvetti U. Moosbrugger M. Martini Evgueni Goudzovski A. Maier P. Hristov G. Lamanna M. Holder Vladimir Kekelidze A. Gonidec N. A. Molokanova K. Eppard H. Dibon Konrad Kleinknecht A. Hirstius A. Ceccucci Andrea Bizzeti Luca Fiorini G. Collazuol W. Kubischta G. Marel M. Markytan M. Lenti E. Menichetti P. Marouelli C. Cerri S. Stoynev U. Koch C. Cheshkov W. Baldini F. Marchetto L. Widhalm M. Savrie P. Cenci H. D. Wahl G.e. Kalmus W. Wislicki M. De Beer B. Peyaud Roberta Arcidiacono M. Behler A. Michetti Marco Clemencic M. Sozzi F. Costantini S. Giudici Cristina Biino P. Rubin E. Monnier C. Morales Morales Mayda Velasco D. T. Madigozhin E. Mazzucato A. I. Zinchenko A. Gianoli I. Mannelli L. Masetti B. Panzer-steindel P. Lubrano A. Nappi Manfred Jeitler G.m. Pierazzini G. Anzivino G. Gouge L. Gatignon B. Vallage R. Sacco G. Neuhofer D.c. Cundy M. Scarpa

subject

Nuclear and High Energy Physics media_common.quotation_subject Signal region Radiative decay Xi0 hyperon Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Asymmetry iperoni acceleratori di particelle NO High Energy Physics - Experiment mesoni K 0103 physical sciences 010306 general physics Xi0 hyperon; radiative decay particelle elementari media_common Physics decadimenti 010308 nuclear & particles physics Branching fraction radiative decay High Energy Physics::Phenomenology Bremsstrahlung mesoni K; iperoni; decadimenti; particelle elementari; acceleratori di particelle High Energy Physics::Experiment Atomic physics Particle Physics - Experiment Conjugate

description

The weak radiative decay Xi0 --> Lambda e+e- has been detected for the first time. We find 412 candidates in the signal region, with an estimated background of 15 +/- 5 events. We determine the branching fraction B(Xi0 --> Lambda e+e-) = [7.6 +/- 0.4(stat) +/- 0.4(syst) +/- 0.2(norm)] x 10^{-6}, consistent with an internal bremsstrahlung process, and the decay asymmetry parameter alpha_{XiLambdaee} = -0.8 +/- 0.2, consistent with that of Xi0 --> Lambda gamma. The charge conjugate reaction Xi0_bar --> Lambda_bar e+e- has also been observed.

year	journal	country	edition	language
2007-03-13

10.1016/j.physletb.2007.04.066 https://hdl.handle.net/11380/610651