Speaker
Description
In recent years, the flavour changing charged current (FCCC) $b→c\bar l ν_l$ transitions have gained special attention both in experiment and in phenomenological study to explore new physics (NP) beyond the standard model (SM). Recently, the BaBar, Belle and LHCb have measured lepton flavour universality (LFU) ratios $R_{D^{(*)}}$ and the world average values of the colliders exhibited around $3.3σ$ tension from their corresponding SM results [1], implies possible hint of NP. Such anomalies associated with $b$ hadron decays raise a question. Whether the similar inconsistency can be observed in charm decays induced by $c→s\bar l ν_l$ transitions! Most of the recent experimental measurements on the pure leptonic and semileptonic $D$ decays except $D_{(s)}^+→η^{(\prime)}\bar l ν_l$ decays agree with the SM predictions. In the last few years, a lot of theoretical efforts have been made for searching NP contribution in $D$ decays [2, 3]. Experimental results of branching ratios for $D_{(s)}^+→η^{(\prime)}\bar l ν_l$ decays show greater than $1σ$ tension from their corresponding SM predictions [4] which indicates possibility of the existence of NP. Inspired by these results, we will study the $D_s^+→η^{(\prime)} μ^+ ν_μ$ decays in $W'$ model [5-7] to explore NP effects. Basically, $W'$ is a theoretically predicted vector boson which arises from the simplest extension of the SM electroweak gauge group by adding extra $SU(2)$ group. In this work, we will predict the new $W'$ coupling parameters using recent experimental results of branching fractions of the above decays. Finally, the effects of NP on the branching fractions will be investigated using our new coupling parameters. Our investigation may be helpful to search $W'$ boson in future collider experiments.
References
[1] Y. Amhis et al. (Heavy Flavor Averaging Group), [arXiv:2206.07501v1 [hep-ex]] (2022).
[2] X. Leng, X. L. Mu, Z. T. Zou and Y. Li, Chinese Phys. C 45, 063107 (2021) [arXiv:2011.01061v1 [hep-ph]].
[3] K. Jain and B. Mawlong, 20th Conference on Flavour Physics and CP Violation, Oxford, MS, 2022, [arXiv:2207.04935v1 [hep-ph]].
[4] R. L. Workman et al. (Particle Data Group), Prog. Theor. Exp. Phys. 2022, 083C01 (2022).
[5] J. D. Gomez, N. Quintero and E. Rojas, Phys. Rev. D 100, 093003 (2019) [arXiv:1907.08357 [hep-ph]].
[6] X. L. Mu, Y. Li, Z. T. Zou and B. Zhu, Phys. Rev. D 100, 113004 (2019) [arXiv:1909.10769 [hep-ph]].
[7] S. Mahata, P. Maji, S. Biswas and S. Sahoo, Int. J. Mod. Phys. A 36, 2150206 (2021).
| Session | Beyond the Standard Model |
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