Exploring \(B_s\rightarrow D_s^{(*)\pm}K^{\mp}\) decays in the presence of a sizable width difference \(\Delta \Gamma_s\)

DOI10.1016/J.NUCLPHYSB.2012.11.012zbMATH Open1262.81194arXiv1208.6463OpenAlexW1580848353MaRDI QIDQ1950498

Robert Knegjens, Manuel Schiller, Kristof De Bruyn, Niels Tuning, R. Fleischer, Marcel Merk

Publication date: 13 May 2013

Published in: Nuclear Physics B (Search for Journal in Brave)

Abstract: The

B_{s} o D_{s}^{(*) p m} K^{m} p

decays allow a theoretically clean determination of

p h i_{s} + g a m m a

, where

p h i_{s}

is the

B_{s}^{0}

-

mixing phase and

g a m m a

the usual angle of the unitarity triangle. A sizable

B_{s}

decay width difference

D e l t a G a m m a_{s}

was recently established, which leads to subtleties in analyses of the

B_{s} o D_{s}^{(*) p m} K^{m} p

branching ratios but also offers new "untagged" observables, which do not require a distinction between initially present

B_{s}^{0}

or

mesons. We clarify these effects and address recent measurements of the ratio of the

B_{s} o D_{s}^{p} m K^{m} p

,

B_{s} o D_{s}^{p} m p i^{m} p

branching ratios. In anticipation of future LHCb analyses, we apply the SU(3) flavour symmetry of strong interactions to convert the

B

-factory data for

B_{d} o D^{(*) p m} p i^{m} p

,

B_{d} o D_{s}^{p m} p i^{m} p

decays into predictions of the

B_{s} o D_{s}^{(*) p m} K^{m} p

observables, and discuss strategies for the extraction of

p h i_{s} + g a m m a

, with a special focus on untagged observables and the resolution of discrete ambiguities. Using our theoretical predictions as a guideline, we make simulations to estimate experimental sensitivities, and extrapolate to the end of the planned LHCb upgrade. We find that the interplay between the untagged observables, which are accessible thanks to the sizable

D e l t a G a m m a_{s}

, and the mixing-induced CP asymmetries, which require tagging, will play the key role for the experimental determination of

p h i_{s} + g a m m a

.

Full work available at URL: https://arxiv.org/abs/1208.6463

Mathematics Subject Classification ID

Nuclear physics (81V35) Strong interaction, including quantum chromodynamics (81V05) Inelastic and multichannel quantum scattering (81U35)