paper

Resonances gone topsy turvy - the charm of QCD or new physics in ?

arXiv:1406.0566

Abstract

We investigate the interference pattern of the charm-resonances with the electroweak penguin operator in the branching fraction of . For this purpose we extract the charm vacuum polarisation via a standard dispersion relation from BESII-data on . In the factorisation approximation (FA) the vacuum polarisation describes the interference fully non-perturbatively. The observed interference pattern by the LHCb collaboration is opposite in sign and and significantly enhanced as compared to the FA. A change of the FA-result by a factor of -2.5, which correspond to a 350%-corrections, results in a reasonable agreement with the data. This raises the question on the size of non-factorisable corrections which are colour enhanced but loop-suppressed. In the parton picture it is found that the corrections are of relative size ~-0.5 when averaged over the open charm-region which is far below -3.5 needed to explain the observed effect. We present combined fits to the BESII- and the LHCb-data, testing for effects beyond the Standard Model (SM)-FA. We cannot find any significant evidence of the parton estimate being too small due to cancellations between the individual resonances. It seems difficult to accommodate the LHCb-result in the standard treatment of the SM or QCD respectively. In the SM the effect can be described in a -dependent shift of the Wilson coefficient combination . We devise strategies to investigate the microscopic structure in future measurements. We show that the charm-resonance effects can accommodate the -anomalies (e.g. ). Hence our findings indicate that the interpretation of the anomaly through a -boson, mediating between and fields, is disfavoured. More generally our results motivate investigations into -physics.

28 pp, 13 figures, 5 tables

References in corpus (6)

Cited by in corpus (19)