Measurement of the branching ratio and form factor of K(L)-->mu(+)mu(-)gamma

A Alavi-Harati; T Alexopoulos; M Arenton; K Arisaka; S Averitte; A R Barker; L Bellantoni; A Bellavance; J Belz; R Ben-David; D R Bergman; E Blucher; G J Bock; C Bown; S Bright; E Cheu; S Childress; R Coleman; M D Corcoran; G Corti; B Cox; M B Crisler; A R Erwin; R Ford; A Glazov; A Golossanov; G Graham; J Graham; K Hagan; E Halkiadakis; J Hamm; K Hanagaki; S Hidaka; Y B Hsiung; V Jejer; D A Jensen; R Kessler; H G Kobrak; J LaDue; A Lath; A Ledovskoy; P L McBride; P Mikelsons; E Monnier; T Nakaya; K S Nelson; H Nguyen; V O'Dell; M Pang; R Pordes; V Prasad; B Quinn; E J Ramberg; R E Ray; A Roodman; M Sadamoto; S Schnetzer; K Senyo; P Shanahan; P S Shawhan; J Shields; W Slater; N Solomey; S V Somalwar; R L Stone; E C Swallow; S A Taegar; R J Tesarek; G B Thomson; P A Toale; A Tripathi; R Tschirhart; S E Turner; Y W Wah; J Wang; H B White; J Whitmore; B Winstein; R Winston; T Yamanaka; E D Zimmerman; KTeV Collaboration

doi:10.1103/PhysRevLett.87.071801

Measurement of the branching ratio and form factor of K(L)-->mu(+)mu(-)gamma

Phys Rev Lett. 2001 Aug 13;87(7):071801. doi: 10.1103/PhysRevLett.87.071801. Epub 2001 Jul 26.

Authors

A Alavi-Harati¹, T Alexopoulos, M Arenton, K Arisaka, S Averitte, A R Barker, L Bellantoni, A Bellavance, J Belz, R Ben-David, D R Bergman, E Blucher, G J Bock, C Bown, S Bright, E Cheu, S Childress, R Coleman, M D Corcoran, G Corti, B Cox, M B Crisler, A R Erwin, R Ford, A Glazov, A Golossanov, G Graham, J Graham, K Hagan, E Halkiadakis, J Hamm, K Hanagaki, S Hidaka, Y B Hsiung, V Jejer, D A Jensen, R Kessler, H G Kobrak, J LaDue, A Lath, A Ledovskoy, P L McBride, P Mikelsons, E Monnier, T Nakaya, K S Nelson, H Nguyen, V O'Dell, M Pang, R Pordes, V Prasad, B Quinn, E J Ramberg, R E Ray, A Roodman, M Sadamoto, S Schnetzer, K Senyo, P Shanahan, P S Shawhan, J Shields, W Slater, N Solomey, S V Somalwar, R L Stone, E C Swallow, S A Taegar, R J Tesarek, G B Thomson, P A Toale, A Tripathi, R Tschirhart, S E Turner, Y W Wah, J Wang, H B White, J Whitmore, B Winstein, R Winston, T Yamanaka, E D Zimmerman; KTeV Collaboration

Affiliation

¹ University of Wisconsin, Madison, Wisconsin 53706, USA.

PMID: 11497879
DOI: 10.1103/PhysRevLett.87.071801

Abstract

We report on the analysis of the rare decay K(L)-->mu(+)mu(-)gamma the 1997 data from the KTeV experiment at Fermilab. A total of 9327 candidate events are observed with 2.4% background, representing a factor of 40 increase in statistics over the current world sample. We find that B(K(L)-->mu(+)mu(-)gamma) = (3.62 +/- 0.04(stat) +/- 0.08(syst)) x 10(-7). The form factor parameter alpha(K*) is measured to be alpha(K*) = -0.160(+0.026)(-0.028). In addition, we make the first measurement of the parameter alpha from the D'Ambrosio-Isidori-Portolés form factor, finding alpha = -1.54 +/- 0.10. In that model, this alpha measurement limits the Cabibbo-Kobayashi-Maskawa parameter rho>-0.2.