Amb motiu del tancament d'estiu, la validació de documents es reprendrà a partir del 28 d'agost de 2026. Disculpeu les molèsties.
Con motivo del cierre de verano, la validación de documentos se reanudará a partir del 28 de agosto de 2026. Disculpad las molestias
Due to the summer closure, document validation will resume starting August 28, 2026. We apologize for any inconvenience.

Document type

Article

Version

Published version

Publication date

All rights reserved

Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/124889

Test of lepton universality in Upsilon(1S) decays at BaBar

Journal Title

Director/Tutor

Journal ISSN

Volume Title

Abstract

The ratio Rtau mu(Υ(1S))=ΓΥ(1S)-->tau+tau-/GammaΥ(1S)-->mu+mu- is measured using a sample of (121.8±1.2)×10[superscript 6]Υ(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 Υ(3S)-->Υ(1S)pi+pi-, Υ(1S)→l+l-, where l=mu, tau. The result, Rtau mu(Υ(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.

Citation

Citation

GARRA TICÓ, Jordi, GRAUGÉS POUS, Eugeni and BABAR Collaboration. Test of lepton universality in Upsilon(1S) decays at BaBar. Physical Review Letters. 2010. Vol. 104, num. 191801. ISSN 0031-9007. [consulted: 9 of August of 2026]. Available at: https://hdl.handle.net/2445/124889

Export metadata

JSON - METS

Share record