Experimental Review of Structures in the $J/\psi \varphi$ Mass Spectrum

Abstract

The discovery of numerous new charmonium-like structures since 2003 have revitalized interest in exotic meson spectroscopy. These structures do not fit easily into the conventional charmonium model, and proposals like four-quark states, hybrids, and re-scattering effects have been suggested as explanations. Since 2009, several new structures were reported in the $J/\psi \varphi$ mass spectrum with the following characteristics: they are the first ones reported decaying into two heavy mesons which contain both a $c\bar{c}$ pair and a $s\bar{s}$ pair; and their masses are well beyond the open charm pair threshold. Conventional $c\bar{c}$ states with a mass beyond the $J/\psi \varphi$ threshold are not expected to decay into this channel and the width is expected to be large, thus they are good candidates for exotic mesons. My focus in this article is to review the recent developments on the structures in the $J/\psi \varphi$ mass spectrum from CDF, Belle and LHCb.

Review published on International Journal of Modern Physics A

References in corpus (8)

• Evidence for a Narrow Near-Threshold Structure in the $J/\psi \varphi$ Mass Spectrum in $B^{+}\to J/\psi \varphi K^{+}$ Decays
• Hadro-Charmonium
• Hadronic molecule structure of the Y(3940) and Y(4140)
• Measurement of the Bc meson mass in the exclusive decay Bc --> Jpsi Pi
• $\{Q\bar{q}\}\{{\bar{Q}}^{{(}^{\prime })}q\}$ molecular states
• Possible Molecular States of $D_s^{\ast }{\bar{D}}_s^{\ast }$ System and Y(4140)
• The hidden charm decay of Y(4140) by the rescattering mechanism
• The molecular systems composed of the charmed mesons in the $H\bar{S}+h.c.$ doublet

Cited by in corpus (16)

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• Search for the X(4140) state in B+->J/psi phi K+ decays with the D0 detector
• The XYZ states revisited
• A New Hadron Spectroscopy
• Scalar tetraquark state candidates: $X(3915)$, $X(4500)$ and $X(4700)$
• Exotic resonances of fully-heavy tetraquarks in a lattice-QCD insipired quark model
• Tetraquark state candidates: $Y(4140)$, $Y(4274)$ and $X(4350)$
• Search for the $Y(4140)$ via $e^{+}{e}^{-}\to \gamma \varphi J/\psi$ at $\sqrt{s}=$ 4.23, 4.26 and 4.36 GeV
• Understanding Y(4274) and X(4320) in the $J/\psi \varphi$ invariant mass spectrum
• Searching for charmoniumlike states with hidden $s\bar{s}$
• Things that go bump in the night: From $J/\psi \varphi$ to other mass spectrum
• Review of bottomonium measurements from CMS
• QCD Exotics
• Review of Physics Results from the Tevatron: Heavy Flavor Physics