Supersymmetric \Delta A_{CP}

TL;DR

This paper investigates whether supersymmetric models with specific flavor symmetries can account for the observed CP asymmetry in D meson decays, which exceeds Standard Model expectations.

Contribution

It explores supersymmetric contributions to _{CP} using models with flavor structures linked to Yukawa couplings, considering recent Higgs mass hints.

Findings

Supersymmetric models can produce _{CP} .001

Flavor symmetries influence the size of CP asymmetry contributions

Light Higgs mass supports the viability of these models

Abstract

There is experimental evidence for a direct CP asymmetry in singly Cabibbo suppressed D decays, \Delta A_{CP} \sim 0.006. Naive expectations are that the Standard Model contribution to \Delta A_{CP} is an order of magnitude smaller. We explore the possibility that a major part of the symmetry comes from supersymmetric contributions. The leading candidates are models where the flavor structure of the trilinear scalar couplings is related to the structure of the Yukawa couplings via approximate flavor symmetries, particularly U(1), [U(1)]^2 and U(2). The recent hints for a lightest neutral Higgs boson with mass around 125 GeV support the requisite order one trilinear terms. The typical value of the supersymmetric contribution to the asymmetry is \Delta A_{CP}^{SUSY}\sim 0.001, but it could be accidentally enhanced by order one coefficients.