Decays $D^+_{(s)}\to \pi(K)^{+}\ell^+\ell^-$ and $D^0\to \ell^+\ell^-$ in the MSSM with and without R-parity

TL;DR

This paper investigates rare charm meson decays within the MSSM framework, analyzing how supersymmetric parameters influence decay rates, CP violations, and lepton flavor ratios, with implications for new physics detection.

Contribution

It provides a comprehensive analysis of supersymmetric effects on rare D meson decays, including CP violation and lepton flavor ratios, considering constraints from other processes.

Findings

Supersymmetric parameters significantly affect direct CP violations.

Mass insertions influence decay rate ratios of muons to electrons.

Differential CP asymmetries are highly sensitive to SUSY parameters.

Abstract

We study the rare decays $D^+\to \pi^{+}\ell^+\ell^-$, $D^+_s\to K^{+}\ell^+\ell^-$ and $D^0\to \ell^+\ell^-(\ell=e,\mu)$ in the minimal supersymmetic standard model with and without R-parity. Using the strong constraints on relevant supersymmetric parameters from $D^0-\bar{D}^0$ mixing and $K^+\to \pi^+\nu\bar{\nu}$ decay, we examine constrained supersymmetry contributions to relevant branching ratios, direct CP violations and ratios of $D^+_{(s)}\to \pi(K)^{+}\mu^+\mu^-$ and $D^+_{(s)}\to \pi(K)^{+}e^+e^-$ decay rates. We find that both R-parity conserving LR as well as RL mass insertions and R-parity violating squark exchange couplings have huge effects on the direct CP violations of $D^+_{(s)}\to \pi(K)^{+}\ell^+\ell^-$, moreover, the constrained LR and RL mass insertions still have obvious effects on the ratios of $D^+_{(s)}\to \pi(K)^{+}\mu^+\mu^-$ and $D^+_{(s)}\to \pi(K)^{+}e^+e^-$ decay rates. The direct CP asymmetries and the ratios of $D^+_{(s)}\to \pi(K)^{+}\mu^+\mu^-$ and $D^+_{(s)}\to \pi(K)^{+}e^+e^-$ decay rates are very sensitive to both moduli and phases of relevant supersymmetric parameters. In addition, the differential direct CP asymmetries of $D^+_{(s)}\to \pi(K)^{+}\ell^+\ell^-$ are studied in detail.