Hybrid phenomenology in a chiral approach

Walaa I. Eshraim; Christian S. Fischer; Francesco Giacosa; Denis Parganlija

doi:10.1140/epjp/s13360-020-00900-z

2024 Impact factor 2.9

EPJ PLUS - Condensed Matter and Complex Systems

Eur. Phys. J. Plus (2020) 135: 945
https://doi.org/10.1140/epjp/s13360-020-00900-z

Regular Article

Hybrid phenomenology in a chiral approach

Walaa I. Eshraim¹^,2, Christian S. Fischer¹^,3, Francesco Giacosa²^,4^c and Denis Parganlija⁵^,6

¹ Institute for Theoretical Physics, Justus-Liebig University, Heinrich-Buff-Ring 16, 35392, Giessen, Germany
² Institute for Theoretical Physics, Goethe University, Max-von-Laue-Str. 1, 60438, Frankfurt am Main, Germany
³ Helmholtz Forschungsakademie Hessen für FAIR (HFHF), GSI Helmholtzzentrum für Schwerionenforschung, Campus Gießen, 35392, Gießen, Germany
⁴ Institute of Physics, Jan Kochanowski University, ul. Uniwersytecka 7, 25-406, Kielce, Poland
⁵ Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10, 1040, Vienna, Austria
⁶ Verbund AG, Information Security and Digitalisation, Am Hof 6a, 1010, Vienna, Austria

^c fgiacosa@ujk.edu.pl

Received: 20 January 2020
Accepted: 29 October 2020
Published online: 1 December 2020

Abstract

We calculate masses and decays of the (lightest) hybrid nonet with exotic quantum numbers $J^{PC} = 1^{- +}$ $J^{PC}=1^{-+}$ and the nonet of their chiral partners with $J^{PC} = 1^{+ -}$ $J^{PC}=1^{+-}$ in the framework of the extended Linear Sigma Model (eLSM). As an input, we identify $π_{1}^{hyb} = π_{1} (1600)$ $\pi _{1}^{hyb}=\pi _{1}(1600)$ as a low-lying hybrid. We investigated interaction terms which fulfill chiral symmetry. For what concerns $π_{1}^{hyb},$ $\pi _{1}^{hyb},$ the most important decays are $π_{1}^{hyb} \to b_{1} π$ $\pi _{1}^{hyb} \rightarrow b_{1}\pi$ , $π_{1} (1600) \to ρ π η$ $\pi _{1}(1600)\rightarrow \rho \pi \eta$ , $π_{1}^{hyb} \to ρ π,$ $\pi _{1}^{hyb} \rightarrow \rho \pi ,$ and $π_{1}^{hyb} \to K K^{*} (892) .$ $\pi _{1}^{hyb}\rightarrow KK^{*}(892).$ The decays $π_{1}^{hyb} \to η π$ $\pi _{1}^{hyb}\rightarrow \eta \pi$ and $π_{1}^{hyb} \to η^{'} π$ $\pi _{1}^{hyb}\rightarrow \eta ^{\prime }\pi$ are expected to be small but nonzero: they follow from a chirally symmetric interaction term that breaks explicitly the axial anomaly. For all the other members of the two hybrid nonets (for which no experimental candidates exist yet), we report decay ratios that may guide ongoing and future experiments.