Direct CP Violation in B+ to J/psi K+ Decay as Probe for New Physics

TL;DR

This paper proposes that measuring direct CP violation in B+ to J/psi K+ decay, especially an asymmetry of 1% or higher, could serve as a clear indicator of New Physics beyond the Standard Model.

Contribution

It highlights direct CP violation in B+ to J/psi K+ decay as a novel, clean probe for detecting New Physics, addressing limitations of previous measurements.

Findings

A 1% or higher asymmetry would suggest New Physics.

Current hints in CP violation measurements are inconclusive due to uncertainties.

Direct CP violation in this mode offers a unique, less ambiguous test for New Physics.

Abstract

Currently there are New Physics hints in mixing-induced CP violation S(phi K0), S(pi0 K0) < S(J/psi K0), unequal direct CP violation A(K+ pi-) differs A(K+ pi0), and maybe even in measured S(J/psi K0) vs prediction from global fit to other data. However, these hints either suffer from experimental uncertainties, or uncertain hadronic corrections, and are not yet unequivocal. Motivated by these hints, however, we point out that a unique probe may be direct CP violation in B to J\psi K mode. An asymmetry observed at 1% or higher would indicate New Physics.