The spectrum and strong couplings of heavy-light hybrids

TL;DR

This paper calculates the spectrum and decay properties of heavy-light hybrid mesons using QCD sum rules within HQET, providing new insights into their masses and decay widths for various quantum states.

Contribution

It introduces specific interpolating currents for heavy-light hybrids and computes their masses and decay widths, advancing understanding of hybrid meson properties in HQET.

Findings

Masses of $0^{++}$ hybrids are similar across modes.

Decay widths differ between TM and TE modes.

Strong couplings to $B(D)\pi$ are quantified.

Abstract

The spectrum of the $0^{++}$, $0^{--}$, $1^{-+}$ and $1^{+-}$ heavy-light hybrids have been calculated in HQET. The interpolated current of the hybrid is chosen as $g\bar q\gamma_{\alpha}G_{\alpha\mu}^aT^ah_{\it v}(x)$, $g\bar q\gamma_{\alpha}\gamma_{5}G_{\alpha\mu}^aT^ah_{\it v}(x)$ and $g\bar q\sigma_{\mu\alpha}G_{\alpha\mu}^aT^ah_{\it v}(x)$. Some strong couplings and decay widths of the heavy-light hybrids to $B(D)\pi$ are calculated by using the QCD sum rules. The mass of $0^{++}$ hybrid with gluon in TM($1^{--}$) or TE($1^{+-}$) mode is found similar, while their decay widths are different. A two-point correlation function between the pion and vacuum is employed and the leading order of $1/M_Q$ expansion is kept in our calculation.