https://doi.org/10.1140/epjc/s10052-016-4044-6
Regular Article - Theoretical Physics
Universal Unitarity Triangle 2016 and the tension between 
and 
in CMFV models
1
Institut fur Kernphysik, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
2
Institut fur Theoretische Teilchenphysik, Karlsruhe Institute of Technology, Engesserstraße 7, 76128, Karlsruhe, Germany
3
TUM-IAS, Lichtenbergstr. 2a, 85748, Garching, Germany
4
Physik Department, TUM, 85748, Garching, Germany
* e-mail: monika.blanke@kit.edu
Received:
17
February
2016
Accepted:
28
March
2016
Published online:
11
April
2016
Motivated by the recently improved results from the Fermilab Lattice and MILC Collaborations on the hadronic matrix elements entering in 
–
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 
and of the angle 
. They follow in this framework from the experimental values of 
and of the CP-asymmetry 
. 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 
, 
, 
and 
as functions of S(v) using the experimental value of 
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 , which turns out to be significantly below its experimental value. This strategy avoids the use of tree-level determinations of and , which are presently subject to considerable uncertainties. On the other hand, if is used instead of as input, 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 and 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 
, 
and 
within the Standard Model.
© The Author(s), 2016
