Interpretations for the X(4160) observed in the double charm production at B factories

Abstract

Belle Collaboration has recently observed a new state, the X(4160), in the process of double charm production $e^{+}{e}^{-}\to J/\psi +X(4160)$ followed by $X(4160)\to D^{\ast }\overline{D^{\ast }}$. We discuss possible interpretations for the X(4160) based on the NRQCD calculations and the potential model estimates for the charmonium spectrum. We first focus on the D-wave spin-singlet $2^{-+}$ charmonium ${}^1{D}_2(2D)$, which is estimated to have a small production rate of about 5% of that for $e^{+}{e}^{-}\to J/\psi +{\eta }_c(1S)$, and therefore is incompatible with the observed data for X(4160). We then discuss the possibility that the X(4160) is the known $J^{PC}=1^{--}$ charmonium state $\psi (4160)$, which can be produced via two photon fragmentation, but the production rate is much smaller than observed for $e^{+}{e}^{-}\to J/\psi +X(4160)$. In contrast to above two possibilities, the ${\eta }_c(4S)$ assignment is a likely one, which is supported by the observed relatively large production rate and non-observation of $D\bar{D}$ decay of X(4160), but we have to understand why ${\eta }_c(4S)$ has such a low mass, which deserves further studies. The P-wave excited state ${\chi }_{c0}(3P)$ is also an interesting candidate, if the observed broad peak around 3.8-3.9 GeV in the recoil mass of $D\bar{D}$ against $J/\psi$ in $e^{+}+e^{-}\to J/\psi +D\bar{D}$ is due to the ${\chi }_{c0}(2P)$ state. Measurements of production angular distributions will be helpful to distinguish between ${\eta }_c(4S)$ and ${\chi }_{c0}(3P)$ assignments. Production mechanisms in nonrelativistic QCD are emphasized.

version to appear in Phys. Lette. B, discussions and references added

References in corpus (11)

• Search for new charmonium states in the processes e+ e- --> J/psi D(*) D(*) at sqrt{s} ~ 10.6 GeV
• Reconciling the X(3872) with the near-threshold enhancement in the D^0\bar{D}^{*0} final state
• Relativistic corrections to $J/\psi$ exclusive and inclusive double charm production at B factories
• QCD corrections to J/psi plus eta_c production in e+e- annihilation at sqrt{s}=10.6 GeV
• Double charm production e^+ e^- \to J/ψ+ c \bar{c} at B factories with next-to-leading order QCD corrections
• Potential-model calculation of an order-v^2 NRQCD matrix element
• The study of leading twist light cone wave function of η_c meson
• NRQCD Factorization for Twist-2 Light-Cone Wave-Functions of Charmonia
• Relativistic effects in the production of pseudoscalar and vector doubly heavy mesons from e^+e^- annihilation
• Weakly-bound Hadronic Molecule near a 3-body Threshold
• The processes $e^{+}{e}^{-}\to J/\Psi {\chi }_{c0},\Psi (2S){\chi }_{c0}$ at $\sqrt{s}=10.6$GeV in the framework of light cone formalism

Cited by in corpus (19)

• Multiquark Resonances
• Higher Charmonia and X,Y,Z states with Screened Potential
• Where is the χ_{c0}(2P)?
• A New Hadron Spectroscopy
• Is the X(3915) the chi_{c0}(2P)?
• The $\mathbf{S}-\mathbf{D}$ mixing and di-electron widths of higher charmonium $1^{--}$ states
• Detecting the long-distance structure of the X(3872)
• Mass spectra for $qc\bar{q}\bar{c}$, $sc\bar{s}\bar{c}$, $qb\bar{q}\bar{b}$, $sb\bar{s}\bar{b}$ tetraquark states with $J^{PC}=0^{++}$ and $2^{++}$
• Charmonium states in QCD-inspired quark potential model using Gaussian expansion method
• Two-Body Strong Decay of the 2P and 3P Charmonium states
• The Strong Decays of X(3940) and X(4160)
• Charmonium states in a coupled-channel model
• $P$-wave charmonium contribution to hidden-charm states from reanalysis of lattice QCD data
• Charmonium: Conventional and $XYZ$ States in a Relativistic Screened Potential Model
• Is the $3S$-$2D$ mixing strong for the charmonia $\psi (4040)$ and $\psi (4160)$?
• Hidden and open charm at Belle (and elsewhere)
• Medium modifications of $1P$-wave charmonia ${\chi }_{cJ}(1P)$ in cold nuclear matter
• $X(3860)$ production in association with $J/\psi$ via $e^{+}{e}^{-}$ annihilation at Belle
• Spectroscopy and Decay Properties of Excited Charmonium States