Sensitivity of the squark flavor mixing to the CP violation of K, B0 and Bs mesons

TL;DR

This paper investigates how squark flavor mixing influences CP violation in K, B0, and Bs mesons within a split-family supersymmetry scenario, predicting potential deviations from the Standard Model observable at Belle II.

Contribution

It provides a detailed analysis of squark flavor mixing effects on CP violation, constrained by experimental data, and predicts observable deviations in specific B meson decay asymmetries.

Findings

Allowed squark mixing parameters are small, up to 0.01 for 1st/3rd and 0.04 for 2nd/3rd generations.

Deviations from the Standard Model are minimal in some CP asymmetries but significant in others like Bs decays.

Future measurements at Belle II can test these squark flavor mixing effects.

Abstract

We study the sensitivity of the squark flavor mixing to the CP violating phenomena of $K$, $B^0$ and $B_s$ mesons in the framework of the split-family scenario, where the first and second family squarks are very heavy, ${\cal O}(10)$TeV, on the other hand, the third family squark masses are at ${\cal O}(1)$TeV. In order to constrain the gluino-sbottom-quark mixing parameters, we input the experimental data of the CP violations of $K$, $B^0$, and $B_s$ mesons, that is $\epsilon_K$, $\phi_d$, and $\phi_s$. The experimental upper bound of the chromo-EDM of the strange quark is also input. In addition, we take account of the observed values $\Delta M_{B^0}$, $\Delta M_{B_s}$, the CKM mixing $|V_{ub}|$, and the branching ratio of $b\to s\gamma$. The allowed region of the mixing parameters are obtained as $|\delta_{13}^{dL(dR)}|=0\sim 0.01$ and $|\delta_{23}^{dL(dR)}|=0\sim 0.04$. By using these values, the deviations from the SM are estimated in the CP violations of the $B^0$ and $B_s$ decays. The deviation from the SM one is tiny in the CP asymmetries of $B^0\to \phi K_S$ and $B^0\to \eta 'K^0$ due to the chromo-EDM of the strange quark. On the other hand, the CP asymmetries $B_s \to \phi \phi$ and $B_s \to \phi \eta '$ could be largely deviated from the SM predictions. We also predict the time dependent CP asymmetry of $B^0\to K^0\bar K^0$ and the semi-leptonic CP asymmetries of $B^0 \to \mu ^-X$ and $B_s \to \mu ^-X$. We expect those precise measurements at Belle II, which will provide us interesting tests for the squark flavor mixing.