Published April 2016 | Version v1
Journal article

Universal Unitarity Triangle 2016 and the tension between ΔMs,d and εK in CMFV models

  • 1. Karlsruhe Institute of Technology, Institut fur Theoretische Teilchenphysik, Karlsruhe (Germany)
  • 2. Karlsruhe Institute of Technology, Institut fur Kernphysik, Eggenstein-Leopoldshafen (Germany)
  • 3. TUM, Physik Department, Garching (Germany)
  • 4. TUM-IAS, Garching (Germany)

Description

Motivated by the recently improved results from the Fermilab Lattice and MILC Collaborations on the hadronic matrix elements entering ΔMs,d in B0s,d- anti B0s,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 stroke Vub vertical stroke / vertical stroke Vcb vertical stroke = 0.0864 ± 0.0025 and of the angle γ = (62.7 ± 2.1) circle. They follow in this framework from the experimental values of ΔMd/ΔMs and of the CP-asymmetry SψKS. 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 stroke Vts vertical stroke, vertical stroke Vtd vertical stroke, vertical stroke Vcb vertical stroke and vertical stroke Vub vertical stroke as functions of S(v) using the experimental value of ΔMs 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 εK, which turns out to be significantly below its experimental value. This strategy avoids the use of tree-level determinations of vertical stroke Vub vertical stroke and vertical stroke Vcb vertical stroke, which are presently subject to considerable uncertainties. On the other hand, if εK is used instead of ΔMs as input, ΔMs,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 ΔMs,d and εK 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+ → π+νanti ν, KL → π0νanti ν and Bs,d → μ+μ- within the Standard Model. (orig.)

Availability note (English)

Available from: http://dx.doi.org/10.1140/epjc/s10052-016-4044-6

Additional details

Publishing Information

Journal Title
European Physical Journal. C, Particles and Fields (Online)
Journal Volume
76
Journal Issue
4
Journal Page Range
p. 1-12
ISSN
1434-6052