S-waves and the measurement of βs in Bs decays

Sheldon Stone

Research output: Contribution to journalConference Articlepeer-review


The CP Violating asymmetry in Bs mixing (βs) is one of the most promising measurements where physics beyond the Standard Model could be revealed. As such, analyses need to be subjected to great scrutiny. The mode Bs → J/ψφ has been used, and the mode Bs → φφ proposed for future measurements. These modes both have two vector particles in the final state and thus angular analyses must be used to disentangle the contributions from CP+ and CP− configurations. The angular distributions, however, could be distorted by the presence of S-waves masquerading as low mass K+K pairs, that could result in erroneous values of βs. The S-waves could well be the result of a final state formed from an s-quark s-quark pair in a 0+ spin-parity state, such as the f0(980) meson. Data driven and theoretical estimates of the Bs decay rate into the CP+ final state J/ψ f0(980) are given, when f0 → π+π. The S-wave contribution in J/ψφ should be taken into account when determining βs by including a K+K S-wave amplitude in the fit. This may change the central value of current results and will also increase the statistical uncertainty. Importantly, the J/ψ f0(980) mode has been suggested as an alternative channel for measuring βs. An expanded version of this paper is available at arXiv:1009.4939 [hep-ph].

Original languageEnglish (US)
JournalProceedings of Science
StatePublished - 2010
Event35th International Conference of High Energy Physics, ICHEP 2010 - Paris, France
Duration: Jul 22 2010Jul 28 2010

ASJC Scopus subject areas

  • General


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