Universal Unitarity Triangle 2016 and the tension between Delta Ms,d and epsilon(K) in CMFV models

作者：Blanke Monika; Buras Andrzej J

来源：European Physical Journal C, 2016, 76(4): 1-12.

DOI：10.1140/epjc/s10052-016-4044-6

Motivated by the recently improved results from the Fermilab Lattice and MILC Collaborations on the hadronic matrix elements entering Delta M-s,M-d in B-s,d(0)-(B) over bar (0)(s,d) mixing, we determine the universal unitarity triangle (UUT) in models with constrained minimal flavour violation (CMFV). Of particular importance are the very precise determinations of the ratio vertical bar V-ub vertical bar/vertical bar V-cb vertical bar = 0.0864 +/- 0.0025 and of the angle gamma = (62.7 +/- 2.1)degrees. They follow in this framework from the experimental values of Delta M-d/Delta M-s and of the CP-asymmetry S-psi KS. As in CMFV models the new contributions to meson mixings can be described by a single flavour-universal variable S(v), we next determine the CKM matrix elements vertical bar V-ts vertical bar, vertical bar V-td vertical bar, vertical bar V-cb vertical bar and vertical bar V-ub vertical bar as functions of S(v) using the experimental value of Delta M-s as input. The lower bound on S(v) in these models, derived by us in 2006, implies then upper bounds on these four CKM elements and on the CP-violating parameter epsilon(K), which turns out to be significantly below its experimental value. This strategy avoids the use of tree-level determinations of vertical bar V-ub vertical bar and vertical bar V-cb vertical bar, which are presently subject to considerable uncertainties. On the other hand, if epsilon(K) is used instead of Delta M-s as input, Delta M-s,M-d are found to be significantly above the data. In this manner we point out that the new lattice data have significantly sharpened the tension between Delta M-s,M-d and epsilon(K) within the CMFV framework. This implies the presence of new physics contributions beyond this framework that are responsible for the breakdown of the flavour universality of the function S(v). We also present the implications of these results for K+ -> pi(+)nu(nu) over bar, K-L -> pi(0)nu(nu) over bar and B-s,B-d -> mu(+)mu(-) within the Standard Model.

• 出版日期2016-4-11