nucl-th digest · May 18, 2018

Analysis of the

b_{1}

meson decay in local tensor bilinear representation

We explore the validity of vector meson dominance in the radiative decay of the

b_{1} (1235)

meson. In order to explain the violation of the vector meson dominance hypothesis in this decay process, we investigate a model where the

b_{1}

meson strongly couples with the local current in tensor bilinear representation. The tensor representation is investigated in the framework of the operator product expansion and we found a low energy decay process that does not follow the usual vector meson dominance hypothesis. The

ω

-like intermediate meson state of quantum numbers

I^{G} (J^{P C}) = 0^{-} (1^{--})

is found to have a nontrivial role in the decay process of the

b_{1}

meson. The spectral structure of the

ω

-like state is found to be close to a

π

ρ

hybrid state, which provides a mechanism that evades the usual vector meson dominance hypothesis. Precise measurements of various decay channels of the

b_{1}

meson are, therefore, required to unravel the internal structure of axial vector mesons.

Comments:: 28 pages, 13 figures, revised version to appear in JHEP
Subjects:: High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:: 1805.06559 [pdf]

JHEP(2018)·7 citations

[Submitted on 17 May 2018] (cross-list from hep-ph)

Decay behavior of the strange and beauty partners of $P_{c}$ hadronic molecules

Yong-Hui Lin🇨🇳 · Chao-Wei Shen🇨🇳 · Bing-Song Zou🇨🇳

We extend our previous study on the decay behavior of $P_{c}$ hadronic molecules to their strange and beauty partners. While $P_{c} (4380)$ and $P_{c} (4450)$ locate just below the $D ˉ Σ_{c}^{*}$ and $D ˉ^{*} Σ_{c}$ thresholds, respectively, their proposed strange partners $N (1875)$ and $N (2080)$ sit just below the $K Σ^{*}$ and $K^{*} Σ$ thresholds, respectively. Using the effective Lagrangian approach as the same as for the study of $P_{c}$ hadronic molecular states and with the couplings determined by the $SU (3)$ flavor symmetry, the decay patterns of $N (1875)$ and $N (2080)$ are obtained assuming them to be the $S$ -wave $K Σ^{*}$ and $K^{*} Σ$ molecules, respectively. It is found that the measured decay properties of $N (1875)$ and $N (2080)$ are reproduced well. Our results suggest that both $N (1875)$ and $N (2080)$ can be ascribed as the hadronic molecular pentaquark states in the hidden strangeness sector with quantum number $I (J^{P}) = 1/2 (3/2^{-})$ . Further checks on their hadronic molecule nature by various experiments are proposed. With the same approach, we also give our predictions for the decay behavior of the possible beauty partners of the $P_{c}$ hadronic molecular states. The $B^{*} Λ_{b}$ is found to be the largest decay mode for both $B Σ_{b}^{*}$ and $B^{*} Σ_{b}$ hadronic molecules, hence can be used to look for the hidden beauty pentaquark states in forthcoming experiments.

Comments:: 11 pages, 5 figures
Subjects:: High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:: 1805.06843 [pdf]

NPA(2018)·41 citations

Friday·May 18, 2018

Analysis of the $b_{1}$ meson decay in local tensor bilinear representation

Decay behavior of the strange and beauty partners of $P_{c}$ hadronic molecules

Affiliations

Analysis of the b1​ meson decay in local tensor bilinear representation

Decay behavior of the strange and beauty partners of Pc​ hadronic molecules

Affiliations

Analysis of the $b_{1}$ meson decay in local tensor bilinear representation

Decay behavior of the strange and beauty partners of $P_{c}$ hadronic molecules