Electromagnetic Dalitz Decays of $D_{(s)}^\ast$ Mesons

TL;DR

This paper calculates the branching ratios, invariant mass spectra, and angular distributions of electromagnetic Dalitz decays of various $D_{(s)}^ ext{*}$ mesons using the Vector-Meson Dominance model, aiding hadronic structure studies.

Contribution

It provides theoretical predictions for electromagnetic Dalitz decays of $D_{(s)}^ ext{*}$ mesons, including form factors and spectra, which are novel in this context.

Findings

Predicted relative branching ratios for $D_{(s)}^ ext{*}$ decays.

Computed dileptonic invariant mass spectra.

Analyzed leptonic angular distributions.

Abstract

Rare electromagnetic decays of charmed mesons are useful laboratories to explore the structure of hadronic states and the interactions between photon and charmed mesons, to test the chiral perturbation theory in flavor sector and to search for new physics including dark photons. In this paper, we calculate the relative branching ratios of electromagnetic Dalitz decays $D_{(s)}^\ast\to D_{(s)}\ell^+\ell^-$ to their corresponding radiative decays $D_{(s)}^\ast\to D_{(s)}\gamma$, the dileptonic invariant mass spectra and the leptonic angular distributions with transition form factor in Vector-Meson Dominance model, where $D_{(s)}^\ast$ represents $D^\ast(2007)^0$, $D^\ast(2010)^\pm$, $D^\ast(2640)^\pm$, $D_s^{\ast\pm}$, $D_{s1}^\ast(2700)^\pm$ and $D_{s1}^\ast(2860)^\pm$.