pith. sign in

Resonances gone topsy turvy - the charm of QCD or new physics in $b \to s \ell^+ \ell^-$?

1 Pith paper cite this work. Polarity classification is still indexing.

1 Pith paper citing it
abstract

We investigate the interference pattern of the charm-resonances $\Psi(3370,4040,4160,4415)$ with the electroweak penguin operator $O_9$ in the branching fraction of $B^+\to K^+\mu\mu$. For this purpose we extract the charm vacuum polarisation via a standard dispersion relation from BESII-data on $e^+e^-\to hadrons$. 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 $q^2$-dependent shift of the Wilson coefficient combination $C^{eff}_9 + C^{' eff}_9$. We devise strategies to investigate the microscopic structure in future measurements. We show that the charm-resonance effects can accommodate the $B \to K^* ll$-anomalies (e.g. $P_5'$). Hence our findings indicate that the interpretation of the anomaly through a $Z'$-boson, mediating between $bs$ and $ll$ fields, is disfavoured. More generally our results motivate investigations into $b \to s\bar cc$-physics.

citation-role summary

background 1

citation-polarity summary

fields

hep-ph 1

years

2026 1

verdicts

UNVERDICTED 1

roles

background 1

polarities

background 1

representative citing papers

A Phenomenological Model of Mesons for Charged Current Weak Decays

hep-ph · 2026-05-13 · unverdicted · novelty 6.0

A symmetry-guided phenomenological model organizes leading current-current operators for charged-current decays of heavy-light mesons and reproduces heavy-quark scaling relations for decay constants and form factors.

citing papers explorer

Showing 1 of 1 citing paper.

  • A Phenomenological Model of Mesons for Charged Current Weak Decays hep-ph · 2026-05-13 · unverdicted · none · ref 66 · internal anchor

    A symmetry-guided phenomenological model organizes leading current-current operators for charged-current decays of heavy-light mesons and reproduces heavy-quark scaling relations for decay constants and form factors.