The process e+e-->mu+mu- has been studied by SND detector at VEPP-2M e+e- collider in the phi(1020)-resonance energy region. The measured effective phi meson leptonic branching ratio: B(phi->l+l-)=sqrt{B(phi->e+e-)*B(phi->mu+mu-)}=(2.89+-0.10+-0.06)*10^{-4} agrees well with the PDG value B(phi->e+e-)=(2.91+-0.07)*10^{-4} confirming mu-e universality. Without additional assumption of mu-e universality the branching ratio B(phi->mu+mu-)=(2.87+-0.20+-0.14)*10^{-4} was obtained.
@article{arxiv.hep-ex/0102029,
title = {Direct measurement of the phi(1020) leptonic branching ratio},
author = {M. N. Achasov and K. I. Beloborodov and A. V. Berdyugin and A. G. Bogdanchikov and A. V. Bozhenok and A. D. Bukin and D. A. Bukin and S. V. Burdin and T. V. Dimova and A. A. Drozdetsky and V. P. Druzhinin and M. S. Dubrovin and I. A. Gaponenko and V. B. Golubev and V. N. Ivanchenko and P. M. Ivanov and A. A. Korol and S. V. Koshuba and A. P. Lysenko and I. N. Nesterenko and E. V. Pakhtusova and E. A. Perevedentsev and A. A. Salnikov and S. I. Serednyakov and V. V. Shary and Yu. M. Shatunov and V. A. Sidorov and Z. K. Silagadze and A. N. Skrinsky and Yu. V. Usov and A. V. Vasiljev},
journal= {arXiv preprint arXiv:hep-ex/0102029},
year = {2008}
}
Comments
RevTeX, 5 pages, 3 figures. To be published in Phys. Rev. Lett