Determination of the sign of the decay width difference in the Bs0 System

The LHCb Collaboration, Matthew Needham, Franz Muheim, Peter Clarke, Yuehong Xie, Stephan Eisenhardt

Research output: Contribution to journalArticlepeer-review

Abstract

The interference between the K+K- S-wave and P-wave amplitudes in B_s -> J/psi K+K- decays with the K+K- pairs in the region around the phi(1020) resonance is used to determine the variation of the difference of the strong phase between these amplitudes as a function of K+K- invariant mass. Combined with the results from our CP asymmetry measurements in B_s -> J/psi phi decays, we conclude that the B_s mass eigenstate that is almost CP =+1 is lighter and decays faster than the mass eigenstate that is almost CP =-1. This determines the sign of the decay width difference DeltaGamma_s == Gamma_L -Gamma_H to be positive. Our result also resolves the ambiguity in the past measurements of the CP violating phase phi_s to be close to zero rather than pi. These conclusions are in agreement with the Standard Model expectations.
Original languageEnglish
Article number241801
Number of pages7
JournalPhysical Review Letters
Volume108
Issue number24
Early online date21 Feb 2012
DOIs
Publication statusPublished - 11 Jun 2012

Fingerprint Dive into the research topics of 'Determination of the sign of the decay width difference in the Bs0 System'. Together they form a unique fingerprint.

Cite this