%0 Journal Article
%T Test of Lepton Universality in Y(1S) Decays at BABAR
%A BABAR Collaboration (del Amo Sanchez, P. et al
%A Azzolini, V.
%A Lopez-March, N.
%A Martinez-Vidal, F.
%A Milanes, D. A.
%A Oyanguren, A.
%J Physical Review Letters
%D 2010
%V 104
%N 19
%I Amer Physical Soc
%@ 0031-9007
%G English
%F BABARCollaborationdelAmoSanchez_etal2010
%O ISI:000277699600013
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=451), last updated on Mon, 11 Apr 2011 13:11:31 +0000
%X The ratio R-tau mu(Y(1S)) = Gamma Y(1S)->tau(+)tau(-)/Gamma(+)(-)(Y(1S)->mu)(mu) is measured using a sample of (121.8 +/- 1.2) x 10(6)Y(3S) events recorded by the BABAR detector. This measurement is intended as a test of lepton universality and as a search for a possible light pseudoscalar Higgs boson. In the standard model (SM) this ratio is expected to be close to 1. Any significant deviations would violate lepton universality and could be introduced by the coupling to a light pseudoscalar Higgs boson. The analysis studies the decays Y(3S) -> Y(1S)pi(+)pi(-), Y(1S) -> l(+)l(-), where l = mu, tau. The result, R-tau μ(Y(1S)) = 1.005 +/- 0.013(stat) +/- 0.022(syst), shows no deviation from the expected SM value, while improving the precision with respect to previous measurements.
%R 10.1103/PhysRevLett.104.191801
%U http://arxiv.org/abs/1002.4358
%U https://doi.org/10.1103/PhysRevLett.104.191801
%P 191801-7pp