Improved branching ratio measurement for the decay K(0)(L) --> &mgr;(+)&mgr;(-)

D Ambrose; C Arroyo; M Bachman; D Connor; M Eckhause; S Graessle; AD Hancock; K Hartman; M Hebert; CH Hoff; GW Hoffmann; GM Irwin; JR Kane; N Kanematsu; Y Kuang; K Lang; R Lee; RD Martin; J McDonough; A Milder; WR Molzon; M Pommot-Maia; PJ Riley; JL Ritchie; PD Rubin; VI Vassilakopoulos VI

doi:10.1103/PhysRevLett.84.1389

Improved branching ratio measurement for the decay K(0)(L) --> &mgr;(+)&mgr;(-)

Phys Rev Lett. 2000 Feb 14;84(7):1389-92. doi: 10.1103/PhysRevLett.84.1389.

Affiliation

¹ University of Texas, Austin, Texas 78712, USA.

PMID: 11017525
DOI: 10.1103/PhysRevLett.84.1389

Abstract

We report results from Experiment 871, performed at the BNL AGS, of a measurement of the branching ratio K(0)(L)-->&mgr;(+)&mgr;(-) with respect to the CP-violating mode K(0)(L)-->pi(+)pi(-). This experiment detected over 6200 candidate &mgr;(+)&mgr;(-) events, a factor of 6 more than that seen in all previous measurements combined. The resulting branching ratio gamma(K(0)(L)-->&mgr;(+)&mgr;(-))/gamma(K(0)(L)-->pi(+)pi(-)) = (3. 474+/-0.057)x10(-6) leads to a branching fraction B(K(0)(L)-->&mgr;(+)&mgr;(-)) = (7.18+/-0.17)x10(-9), which is consistent with the current world average, and reduces the uncertainty in this decay mode by a factor of 3.