22nd Conference on Flavor Physics and CP Violation (FPCP 2024)

Searching new physics in c→ul+l− decays with non-universal Z' model

28 May 2024, 15:15

15m

Chulalongkorn University

Parallel session Rare decays of hadrons and leptons Parallel - 5

Speaker

Ms Mansi Mandal (National Institute of Technology Durgapur)

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, $D^0-\overline{D^0}$ mixing and CP violation [3, 4]. The experimental upper bounds for the branching fractions are constrained at $7.9\times {10}^{-8}$ for $D^0\to e^{+}{e}^{-}$[5] and $6.2\times {10}^{-9}$ for $D^0\to {\mu }^{+}{\mu }^{-}$[6]. Recent results from the LHCb have provided the limit of the branching ratio of lepton flavour violating decays $D^0\to {\mu }^{\mp }{e}^{\pm }$ as $B(D^0\to {\mu }^{\mp }{e}^{\pm })<1.3\times {10}^{-8}$ [7] at $90\mathrm{\%}$ confidence level. The Glashow-Iliopoulos-Maiani mechanism effectively suppresses the flavour changing neutral currents (FCNC) decays involving $𝑐\to 𝑢$ transitions which makes them sensitive to new physics (NP) effects. Among various NP models, the non-universal $Z^{\prime }$ 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 $Z^{\prime }$ boson. In this work, we intend to investigate the rare charm decays involving $c\to u{l}^{+}{l}^{-}$ transition in non-universal $Z^{\prime }$ model. We estimate the branching fractions of the decays $D\to \rho l^{+}{l}^{-}$, $D\to \pi l^{+}{l}^{-}$, and $D_s\to K{l}^{+}{l}^{-}$ in $Z^{\prime }$ model with the leptonic couplings constrained from $D\to {\mu }^{+}{\mu }^{-}$ decays. We expect our study will provide more opportunities to explore NP in the charm sector.

References

1. S. Sahoo and R. Mohanta, New physics effects in charm meson decays involving $c\to u{l}^{+}{l}^{-}(l_i^{\pm }{l}_j^{\mp })$ transitions, Eur. Phys. J. C 77, 344 (2017).
2. R. Bause, M. Golz, G. Hiller and A. Tayduganov, The new physics reach of null tests with $D\to \pi ll$ and $D_s\to Kll$ decays, Eur. Phys. J. C 80, 65 (2020).
3. A. Lenz and G. Wilkinson, Mixing and CP violation in the charm system, Annu. Rev. Nucl. Part. Sci. 71, 59 (2021).

4. R. Aaij et al. [LHCb Collaboration], Observation of CP Violation in Charm Decays, Phys. Rev. Lett. 122, 211803 (2019) [arXiv: 1903.08726 [hep-ex]].

5. M. Petric et al. [Belle Collaboration], Search for leptonic decays of $D_0$ mesons, Phys. Rev. D 81, 091102 (2010).

6. R. Aaij et al. [LHCb Collaboration], Search for the rare decay $D_0\to {\mu }^{+}{\mu }^{-}$, Phys. Lett. B 725, 15 (2013).

7. R. Aaij et al. [LHCb Collaboration], Search for the lepton-flavour violating decay $D_0\to e^{\pm }{\mu }^{\mp }$, Phys. Lett. B 754, 167 (2016).

Presentation materials

Mansi Mandal FPCP.pdf