Purely leptonic decay of the charged vector mesons ($D_{(s)}^{*+}$)

Author:

Kalpalata Dash, P. C. Dash, R. N. Panda, Susmita Kar, N. Barik

Keyword:

High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph)

journal:

date:

2023-12-11 00:00:00

Abstract

In the wake of the first-ever experimental study of the decay: $D_s^{*+}\to e^+\nu_e$ with $e^+e^-$ collision data taken with the BESIII detector at the BEPCII collider, we study the purely leptonic decay of the charged vector mesons ($D^*_{(s)}$) in the framework of a relativistic independent quark (RIQ) model based on an average flavor-independent confining potential in equally mixed scalar-vector harmonic form. We calculate the decay constants: $f_{D^*}$ and $f_{D_s^*}$ representing the decay amplitudes using the meson wave function derivable in the RIQ model. Our results for the decay constants: $f_{D^*}=197\pm 14$ MeV, $f_{D_s^*}=236\pm 19$ MeV, decay widths: $\Gamma (D^*\to e\nu_e)=(57.52\pm 8.18) \ \mu eV$, $\Gamma (D_s^*\to e\nu_e) = (1.80\pm 0.27) \ meV$ and corresponding branching fractions (BFs): ${\cal B} (D^*\to e\nu_e)= (6.89\pm 0.99)\times 10^{-10}$ and ${\cal B} (D_s^*\to e\nu_e)= (2.57\pm 1.10) \times 10^{-5}$ are in good agreement with available experimental data and other model predictions including those from the lattice QCD calculation. Our predictions: ${\cal R}_{D^{*+}}=0.066$ and ${\cal R}_{D_s^{*+}}=0.116$, which correspond to the ratios of the BFs for $D_{(s)}^{*+}$ decays in their $\tau^-$ mode to the corresponding values in $e^-$ mode, are in good agreement with the results of the LQCD and LFQM calculations. Our predicted ${\cal R}_{D_{(s)}^{*+}}$ clearly violates the lepton flavor universality (LFU) hinting at new physics (NP) beyond the Standard Model (SM).

PDF: Purely leptonic decay of the charged vector mesons ($D_{(s)}^{*+}$).pdf