Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Investigating charmed hybrid baryons via QCD sum rules

Hui-Min Yang, Xuan Luo, Hua-Xing Chen, Wei Chen

TL;DR

This work addresses the existence and spectrum of charmed hybrid baryons by applying QCD sum rules within the heavy quark effective theory (HQET). It constructs 28 interpolating currents and analyzes 19 states across $qqcg$, $qscg$, and $sscg$ configurations, identifying the lowest-lying states in the $SU(3)_F$ flavor $\mathbf{6}_F$ multiplet with masses $M_{\Sigma_{cg}(1/2^+)} = 3.36^{+0.27}_{-0.26}$ GeV, $M_{\Xi'_{cg}(1/2^+)} = 3.59 \pm 0.20$ GeV, and $M_{\Omega_{cg}(1/2^+)} = 3.82 \pm 0.21$ GeV. The analysis includes ${\mathcal{O}}(1/m_Q)$ corrections, yielding a notable intra-doublet mass splitting driven by chromomagnetic interactions. The authors propose experimental searches in $P$-wave decay channels such as $ND^{(*)}$, $\Lambda D^{(*)}$, and $\Xi D^{(*)}$ to probe the gluonic components of these states, thereby advancing understanding of gluonic excitations in hadron structure.

Abstract

We investigate charmed hybrid baryons using the QCD sum rule method within the framework of heavy quark effective theory. We construct twenty-eight interpolating currents for charmed hybrid baryons, seven of which are employed in QCD sum rule analyses of nineteen states with quark-gluon configurations $qqcg$, $qscg$, and $sscg$ ($q = u/d$). The masses of the lowest-lying charmed hybrid baryons in the $SU(3)$ flavor $\mathbf{6}_F$ representation are calculated to be $M_{Σ_{cg}(1/2^+)} = 3.36^{+0.27}_{-0.26}~\rm{GeV}$, $M_{Ξ^\prime_{cg}(1/2^+)} = 3.59\pm 0.20~\rm{GeV}$, and $M_{Ω_{cg}(1/2^+)} = 3.82\pm 0.21~\rm{GeV}$. We propose that future experiments search for these states via their $P$-wave decay channels $ND^{(*)}$, $ΛD^{(*)}$, and $ΞD^{(*)}$, respectively. Such investigations would provide valuable insight into the role of gluonic excitations in hadron structure.

Investigating charmed hybrid baryons via QCD sum rules

TL;DR

This work addresses the existence and spectrum of charmed hybrid baryons by applying QCD sum rules within the heavy quark effective theory (HQET). It constructs 28 interpolating currents and analyzes 19 states across , , and configurations, identifying the lowest-lying states in the flavor multiplet with masses GeV, GeV, and GeV. The analysis includes corrections, yielding a notable intra-doublet mass splitting driven by chromomagnetic interactions. The authors propose experimental searches in -wave decay channels such as , , and to probe the gluonic components of these states, thereby advancing understanding of gluonic excitations in hadron structure.

Abstract

We investigate charmed hybrid baryons using the QCD sum rule method within the framework of heavy quark effective theory. We construct twenty-eight interpolating currents for charmed hybrid baryons, seven of which are employed in QCD sum rule analyses of nineteen states with quark-gluon configurations , , and (). The masses of the lowest-lying charmed hybrid baryons in the flavor representation are calculated to be , , and . We propose that future experiments search for these states via their -wave decay channels , , and , respectively. Such investigations would provide valuable insight into the role of gluonic excitations in hadron structure.

Paper Structure

This paper contains 5 sections, 29 equations, 5 figures, 2 tables.

Table of Contents

  1. Introduction
  2. Charmed hybrid baryon currents
  3. Results at the leading order
  4. Results at the ${\mathcal{O}}(1/m_Q)$ order
  5. Discussions and Conclusion

Figures (5)

  • Figure 1: Categorization of charmed hybrid baryon currents.
  • Figure 2: CVG$^{(\prime,\prime\prime)}$ and PC as functions of the Borel mass $T$, with the threshold value set to be $\omega_c = 2.95$ GeV. These curves are derived using the current $J_{\Sigma_{cg}^+,\bar{3}_c,1,1,1/2^+}$, which belongs to the doublet $[\Sigma_{cg}^+,\bar{3}_c,1,1, G]$.
  • Figure 3: Variations of (a) $\bar{\Lambda}_+$ and (b) $f_+$ as functions of the Borel mass $T$, where the long-dashed, solid, and short-dashed curves correspond to fixed threshold values $\omega_c = 2.85~\mathrm{GeV}$, $2.95~\mathrm{GeV}$, and $3.05~\mathrm{GeV}$, respectively. These results are obtained using the current $J_{\Sigma_{cg}^+,\bar{3}c,1,1,1/2^+}$, which is associated with the doublet $[\Sigma_{cg}^+,\bar{3}_c,1,1,G]$.
  • Figure 4: Variations of (a) $K_+$ and (b) $\Sigma_+$ as functions of the Borel mass $T$, where the long-dashed, solid, and short-dashed curves correspond to fixed threshold values $\omega_c = 2.85~\mathrm{GeV}$, $2.95~\mathrm{GeV}$, and $3.05~\mathrm{GeV}$, respectively. These results are obtained using the current $J_{\Sigma_{cg}^+,\bar{3}c,1,1,1/2^+}$, which is associated with the doublet $[\Sigma_{cg}^+,\bar{3}_c,1,1,G]$.
  • Figure 5: Variations of $M_+$ as functions of (a) the threshold value $\omega_c$ and (b) the Borel mass $T$. In the left panel the long-dashed, solid, and short-dashed curves correspond to fixed Borel masses $T = 0.37~\mathrm{GeV}$, $0.38~\mathrm{GeV}$, and $0.40~\mathrm{GeV}$, respectively. In the right panel the long-dashed, solid, and short-dashed curves correspond to fixed threshold values $\omega_c = 2.85~\mathrm{GeV}$, $2.95~\mathrm{GeV}$, and $3.05~\mathrm{GeV}$, respectively. These results are obtained using the current $J_{\Sigma_{cg}^+,\bar{3}c,1,1,1/2^+}$, which is associated with the doublet $[\Sigma_{cg}^+,\bar{3}_c,1,1,G]$.