Jul 20 – 27, 2011
Alpes Congrès - Alpexpo
Europe/Paris timezone

Exploring New Physics in the C7-C7' plane

Jul 22, 2011, 12:15 PM
Oisans (Alpes Congès - Alpexpo)


Alpes Congès - Alpexpo

Parallel session talk Flavour Physics and Fundamental Symmetries Flavour Physics and Fundamental Symmetries


Dr Sébastien Descotes-Genon (LPT Orsay)


The Wilson coefficient C_7 governing the radiative electromagnetic decays of B meson has been calculated to a very high accuracy in the Standard Model, but till date there is no convincing model-independent experimental bound on either the magnitude or the sign of C_7. In the present paper, we attempt at constraining both the magnitude and sign of C_7 using a systematic approach. We consider already measured observables like the branching ratios of B --> Xs mu+ mu- and B --> Xs gamma, the isospin and CP asymmetries in B --> K* gamma, as well as A_FB and F_L in B --> K* l+ l-. We also discuss the transverse observable A_T^(2) which, once measured, may help to disentangle some of the scenarios considered. We explore the constraints on C_7, C_9, C_10 as well as their chirality-flipped counterparts. Within our framework, we find that we need to extend the constraints up to 1.6 sigma to allow for the "flipped-sign solution" of C_7. The SM solution for C_7 exhibits a very mild tension if New Physics is allowed in dipole operators only.

Primary author


Dr Diptimoy Ghosh (Tata Institute of Fundamental Research of Mumbai) Dr Joaquim Matias (Universitat Autonoma de Barcelona) Marc Ramon (Universtitat Autonoma de Barcelona)

Presentation materials