Bs mixing observables and |Vtd/Vts| from sum rules

King, Daniel; Lenz, Alexander; Rauh, Thomas

Abstract

We consider the effects of a non-vanishing strange-quark mass in the determination of the full basis of dimension six matrix elements for Bs mixing, in particular we get for the ratio of the V − A Bag parameter in the Bs and Bd system: B s Q1 /B d Q1 = 0.987+0.007 −0.009. Combining these results with the most recent lattice values for the ratio of decay constants fBs /fBd we obtain the most precise determination of the ratio ξ = fBs q B s Q1 /fBd q B d Q1 = 1.2014+0.0065 −0.0072 in agreement with recent lattice determinations. We find ∆Ms = (18.5 +1.2 −1.5 )ps−1 and ∆Md = (0.547+0.035 −0.046)ps−1 to be consistent with experiments at below one sigma. Assuming the validity of the SM, our calculation can be used to directly determine the ratio of CKM elements |Vtd/Vts| = 0.2045+0.0012 −0.0013, which is compatible with the results from the CKM fitting groups, but again more precise.

Citation

King, D., Lenz, A., & Rauh, T. (2019). Bs mixing observables and |Vtd/Vts| from sum rules. Journal of High Energy Physics, 2019(5), Article 34. https://doi.org/10.1007/jhep05%282019%29034

• Journal Article Type: Article
• Acceptance Date: May 26, 2019
• Online Publication Date: May 30, 2019
• Publication Date: May 31, 2019
• Deposit Date: May 29, 2019
• Publicly Available Date: May 29, 2019
• Journal: Journal of High Energy Physics
• Print ISSN: 1126-6708
• Publisher: Scuola Internazionale Superiore di Studi Avanzati (SISSA)
• Peer Reviewed: Peer Reviewed
• Volume: 2019
• Issue: 5
• Article Number: 34
• DOI: https://doi.org/10.1007/jhep05%282019%29034