Diquark-Antidiquark Interpretation of Mesons

TL;DR

This paper explores the tetraquark (diquark-antidiquark) model to interpret exotic mesons like X(3872) and Y(10890), calculating their spectra, decay modes, and radiative decays to better understand their nature.

Contribution

It provides a detailed non-relativistic quark model analysis of exotic mesons as tetraquark states, including spectral calculations and decay mode predictions.

Findings

X(3872) is a $1^{++}$ tetraquark state with specific diquark configurations.

Y(10890) is a $1^{--}$ P-wave tetraquark state.

Decay mode analysis supports the tetraquark interpretation of these states.

Abstract

We study the spectroscopy of the states which defy conventional $c\bar{c}$ charmonium and $b\bar{b}$ bottomonium interpretation respectively, and are termed as exotic states. In August 2003 a state X(3872), was discovered [K. Abe\textit{\ et al.} (Belle Collaboration), Phys. Rev. Lett. \textbf{91}, 262001 (2003) [arXiv:hep-ex/0309032]] and in December 2007 a state Y(10890) was reported [K. F. Chen \textit{et. al.} [Belle Collaboration], Phys. Rev. Lett. \textbf{100}, 112001 (2008) [arXiv:0710.2577]. One possible interpretation of such exotic state is that they are tetraquark (diquark-antiquark) states. Applying knowledge of non-relativistic constituent quark model, we calculate the spectrum of hidden charm and bottom exotic mesons within diquark-antidiquark model. We investigate that X(3872) is $1^{++}$ state of the kind $X_{[cq]}=([cq]_{S=1}[ \bar{c}\bar{q}]_{S=0})_{S\mathrm{-wave}}$, and Y(10890) is $1^{--}$ state of the kind $Y_{[bq]}=([bq]_{S=0}[\bar{b}\bar{q}]_{S=0})_{\mathrm{P-wave}}$ and calculate the decay modes of these exotic states, further supporting X(3872) and Y(10890) as tetraquark (diquark-antidiquark) states and resolve the puzzling features of the data. We study the radiative decays of these states, using the idea of Vector Meson Dominance (VMD), which we hope will increase an insight about these tetraquark states.