Speaker
Description
Charm decays have immense potential to probe physics beyond the standard model [1, 2]. The charm sector has shown some interesting phenomena, for instance, $D^0-\bar{D^0}$ mixing and CP violation [3, 4]. The experimental upper bounds for the branching fractions are constrained at $7.9×10^{-8}$ for $D^0→e^+ e^-$[5] and $6.2×10^{-9}$ for $D^0→μ^+ μ^-$[6]. Recent results from the LHCb have provided the limit of the branching ratio of lepton flavour violating decays $D^0→μ^∓ e^±$ as $B(D^0→μ^∓ e^±)<1.3×10^{-8}$ [7] at $90\%$ confidence level. The Glashow-Iliopoulos-Maiani mechanism effectively suppresses the flavour changing neutral currents (FCNC) decays involving $𝑐 → 𝑢$ transitions which makes them sensitive to new physics (NP) effects. Among various NP models, the non-universal $Z'$ model is one of the best appreciated NP models. In this model, the rare decays occur at the tree level as they are mediated by a new gauge boson particle, the $Z'$ boson. In this work, we intend to investigate the rare charm decays involving $c→ul^+ l^-$ transition in non-universal $Z'$ model. We estimate the branching fractions of the decays $D→ρl^+ l^-$, $D→πl^+ l^-$, and $D_s→Kl^+ l^-$ in $Z'$ model with the leptonic couplings constrained from $D→μ^+ μ^-$ decays. We expect our study will provide more opportunities to explore NP in the charm sector.
References
- S. Sahoo and R. Mohanta, New physics effects in charm meson decays involving $c→ul^+ l^- (l_i^± l_j^∓)$ transitions, Eur. Phys. J. C 77, 344 (2017).
- R. Bause, M. Golz, G. Hiller and A. Tayduganov, The new physics reach of null tests with $D→πll$ and $D_s→Kll$ decays, Eur. Phys. J. C 80, 65 (2020).
- A. Lenz and G. Wilkinson, Mixing and CP violation in the charm system, Annu. Rev. Nucl. Part. Sci. 71, 59 (2021).
-
R. Aaij et al. [LHCb Collaboration], Observation of CP Violation in Charm Decays, Phys. Rev. Lett. 122, 211803 (2019) [arXiv: 1903.08726 [hep-ex]].
-
M. Petric et al. [Belle Collaboration], Search for leptonic decays of $D_0$ mesons, Phys. Rev. D 81, 091102 (2010).
-
R. Aaij et al. [LHCb Collaboration], Search for the rare decay $D_0→μ^+ μ^-$, Phys. Lett. B 725, 15 (2013).
-
R. Aaij et al. [LHCb Collaboration], Search for the lepton-flavour violating decay $D_0→e^± μ^∓$, Phys. Lett. B 754, 167 (2016).
