Theoretical uncertainty in sin 2beta: An update

The source of theoretical uncertainty in the extraction of sin 2beta from the measurement of the golden channel Bd -> J/psi K0 is briefly reviewed. An updated estimate of this uncertainty based on SU(3) flavour symmetry and the measurement of the decay Bd -> J/psi pi0 is also presented.Comment: 8 pages, 2 figures, 3 tables, Proceedings of CKM2010, the 6th International Workshop on the CKM Unitarity Triangle, University of Warwick, UK, 6-10 September 201

Effective Theories for Quark Flavour Physics

The purpose of these lectures is to provide the reader with an idea of how we can probe New Physics with quark flavour observables using effective theory techniques. After giving a concise review of the quark flavour structure of the Standard Model, we introduce the effective Hamiltonian for quark weak decays. We then consider the effective Hamiltonian for $\Delta F=2$ transitions in the Standard Model and beyond. We discuss how meson-antimeson mixing and CP violation can be described in terms of the $\Delta F=1$ and $\Delta F=2$ effective Hamiltonians. Finally we present the Unitarity Triangle Analysis and discuss how very stringent constraints on New Physics can be obtained from $\Delta F=2$ processes.Comment: Lectures given at the Les Houches summer school: EFT in Particle Physics and Cosmology, 3-28 July 2017, Les Houches, France. 82 pages, 15 figures. v2: misprints corrected, references adde

Model-independent Bounds on the Standard Model Effective Theory from Flavour Physics

Meson-antimeson mixing provides the most stringent constraints on baryon- and lepton-number conserving New Physics, probing scales higher than $10^5$ TeV. In the context of the effective theory of weak interactions, these constraints translate into severe bounds on the coefficients of $\Delta F=2$ operators. Generalizing to the effective theory invariant under the Standard Model gauge group, valid above the electroweak scale, the bounds from $\Delta F=2$ processes also affect $\Delta F=1$ and even $\Delta F=0$ operators, due to log-enhanced radiative corrections induced by Yukawa couplings. We systematically analyze the effect of the renormalization group evolution above the electroweak scale and provide for the first time the full set of constraints on all relevant dimension-six operators.Comment: 8 pages, 8 tables. Table of DF=2 bounds on weak Hamiltonian added. Revised version published in Physics Letters