CP violation in B mesons using Dalitz plot asymmetries

TL;DR

This paper introduces a novel method using Dalitz plot asymmetries in B meson decays to detect CP violation without flavor or time tagging, requiring fewer B mesons than traditional methods.

Contribution

It proposes a new type of asymmetry measurement that simplifies CP violation detection in B decays and enhances parameter constraints with fewer B mesons.

Findings

New asymmetries do not need flavor or time tagging.

Standard Model requires 2×10^8/η B's for measurement.

Two-Higgs doublet model needs only 10^7 B's for better constraints.

Abstract

We study CP violation in $B\to K^* \ell^+\ell^-$ using generalized Dalitz plot asymmetries in the angular distribution. These new kind of asymmetries are constructed by adding B and ${\bar B}$ events, and do not require flavor or time tagging, nor is the presence of strong phases needed. Using this method one requires about $2 \times 10^8/\eta$ B's to measure the CP violating parameter $\eta$ in the Standard model. The two--Higgs doublet model requires only $10^7$ B's to constrain parameters better than done by the electric dipole moment of the neutron.