CP-Conserving Unparticle Phase Effects on the Unpolarized and Polarized Direct CP Asymmetry in $b \to d \ell^+\ell^-$ Transition

TL;DR

This paper investigates how unparticle physics, specifically the CP-conserving phase, influences the direct CP asymmetry in the rare decay process $b o d \, \ell^+ \ell^-$, revealing significant effects depending on unparticle parameters.

Contribution

It introduces the impact of unparticle CP-conserving phases on CP asymmetries in $b \to d \ell^+ \ell^-$ decay, highlighting the dependence on unparticle scaling dimension and potential for observable effects.

Findings

CP asymmetries strongly depend on unparticle parameters.

Significant enhancement or suppression of CP asymmetry occurs with varying unparticle scale dimension.

CP asymmetries vanish near $d_{\UP} \sim 1.1$.

Abstract

We examine the unparticle CP-conserving phase effects on the direct CP asymmetry for both polarized and unpolarized lepton in the inclusive $b\to d \ell^+ \ell^-$ transition, where the flavor changing neutral currents are forbidden at tree level but are induced by one-loop penguin diagrams. The averaged polarized and unpolarized CP asymmetries depict strong dependency on the unparticle parameters. In particular, a sizable discrepancy corresponding to the standard model is achieved when the scale dimension value is $1<d_{\UP}< 2$. We see that the unparticle stuff significantly enhances, suppresses or changes the sign of the CP asymmetry depending on the definite value of the scaling dimension $d_{\UP}$. Especially, when $d_{\UP}\sim 1.1$ the CP asymmetries vanish.