Dispersive analysis of K_{L mu3} and K_{L e3} scalar and vector form factors using KTeV data

V. Bernard (1) , M. Oertel (2) , E. Passemar (1) , J. Stern (1) , E. Abouzaid , M. Arenton , A.R. Barker , L. Bellantoni , E. Blucher , G. J. Bock , E. Cheu , R. Coleman , M.D. Corcoran , B. Cox , A.R. Erwin , C.O. Escobar , A. Glazov , R.A. Gomes , P. Gouffon , Y. B. Hsiung , D.A. Jensen , R. Kessler , K. Kotera , A. Ledovskoy , P. L. Mcbride , E. Monnier , H. Nguyen , R. Niclasen , D.G. Phillips , E.J. Ramberg , R.E. Ray , M. Ronquest , E. Santos , W. Slater , D. Smith , N. Solomey , E. C. Swallow , P. A. Toale , R. Tschirhart , Y. W. Wah , J. Wang , H. B. White , J. Whitmore , M. J. Wilking , R. Winston , E.T. Worcester , T. Yamanaka , E. D. Zimmerman , R.F. Zukanovich

1 IPNO - Institut de Physique Nucléaire d'Orsay
2 LUTH (UMR_8102) - Laboratoire Univers et Théories

Using the published KTeV samples of K_L --> pi^{\pm} e^{\mp} nu and K_L --> pi^{\pm} mu^{\mp} nu decays [1], we perform a reanalysis of the scalar and vector form factors based on the dispersive parameterization [2,3]. We obtain phase space integrals I^e_K = 0.15446 \pm 0.00025 and I^{mu}_K = 0.10219 \pm 0.00025. For the scalar form factor parameterization, the only free parameter is the normalized form factor value at the Callan-Treiman point (C); our best fit results in ln C = 0.1915 \pm 0.0122. We also study the sensitivity of C to different parametrizations of the vector form factor. The results for the phase space integrals and C are then used to make tests of the Standard Model. Finally, we compare our results with lattice QCD calculations of F_K/F_pi and f_+(0).

Domaines: Physique des Hautes Energies - Expérience [hep-ex]

V. Bernard, M. Oertel, E. Passemar, J. Stern, E. Abouzaid, et al.. Dispersive analysis of K_{L mu3} and K_{L e3} scalar and vector form factors using KTeV data. Physical Review D, 2010, 81, pp.052001. ⟨10.1103/PhysRevD.81.052001⟩. ⟨in2p3-00454551⟩