arXiv subjects

C. W. Xiao

Publications and source records attributed to C. W. Xiao.

42 records · Page 3Linked to original sources

arXiv2012

Narrow bound states of the DNN system

We report on a recent calculation of the properties of the $DNN$ system, a charmed meson with two nucleons. The system is analogous to the $\bar K NN$ system substituting a strange quark by a charm quark. Two different methods are used to evaluate the binding and width, the Fixed Center approximation to the Faddeev equations and a variational calculation. In both methods we find that the system is bound by about 200 MeV and the width is smaller than 40 MeV, a situation opposite to the one of the $\bar K NN$ system and which makes this state well suited for experimental observation.

nucl-th↗

arXiv2012

A prediction of $D^*$-multi-$ρ$ states

We present a study of the many-body interaction between a $D^*$ and multi-$ρ$. We use an extrapolation to SU(4) of the hidden gauge formalism, which produced dynamically the resonances $f_2(1270)$ in the $ρρ$ interaction and $D^*_2(2460)$ in the $ρD^*$ interaction. Then let a third particle, $ρ$, $D^*$, or a resonance collide with them, evaluating the scattering amplitudes in terms of the Fixed Center Approximation of the Faddeev equations. We find several clear resonant structures above $2800\mev$ in the multibody scattering amplitudes. They would correspond to new charmed resonances, $D^*_3$, $D^*_4$, $D^*_5$ and $D^*_6$, which are not yet listed in the PDG, which would be analogous to the $ρ_3(1690)$, $f_4(2050)$, $ρ_5(2350)$, $f_6(2510)$ and $K^*_3(1780)$, $K^*_4(2045)$, $K^*_5(2380)$ described before as multi-$ρ$ and $K^*$-multi-$ρ$ states respectively.

hep-ph↗

arXiv2012

$J/ψ$ reaction mechanisms and suppression in the nuclear medium

Recent studies of the interaction of vector mesons with nuclei make possible and opportune the study of the interaction of the $J/ψ$ with nuclei and the investigation of the origin of the $J/ψ$ suppression in its propagation thorough a nuclear medium. We observe that the transition of $J/ψN$ to $VN$ with $V$ being a light vector, $ρ, ω,ϕ$, together with the inelastic channels, $J/ψN \to \bar D Λ_c$ and $J/ψN \to \bar D Σ_c$ leads to a particular shape of the inelastic cross section. Analogously, we consider the mechanisms where the exchanged $D$ collides with a nucleon and gives $πΛ_c$ or $πΣ_c$. The cross section has a peak around $\sqrt s=4415$ MeV, where the $J/ψN$ couples to a resonance predicted recently. We study the transparency ratio for electron induced $J/ψ$ production in nuclei at about 10 GeV and find that 30 - 35% of the $J/ψ$ produced in heavy nuclei are absorbed inside the nucleus. This ratio is in line with depletions of $J/ψ$ though matter observed in other reactions.

nucl-th↗

arXiv2012

A narrow $DNN$ quasi-bound state

The energies and widths of $DNN$ quasi-bound states with isospin I=1/2 are evaluated in two methods, the fixed center approximation to the Faddeev equation and the variational method approach to the effective one-channel Hamiltonian. The $DN$ interactions are constructed so that they dynamically generate the $Λ_c(2595)$ (I=0, $J^π =1/2^-$) resonance state. We find that the system is bound by about 250 MeV from the $DNN$ threshold, $\sqrt{s} \sim 3500$ MeV. Its width including both the mesonic decay and the $D$ absorption, is estimated to be about 20-40 MeV. The I=0 $DN$ pair in the $DNN$ system is found to form a cluster that is similar to the $Λ_c(2595)$.

hep-ph↗

arXiv2012

Interaction of vector mesons with baryons and vectors in the nuclear medium

In this talk we present a short review of recent developments concerning the interaction of vector mesons with baryons and with nuclei. We begin with the hidden gauge formalism for the interaction of vector mesons, then review results for vector baryon interaction and in particular the resonances which appear as composite states, dynamically generated from the interaction of vector mesons with baryons. New developments concerning the mixing of these states with pseudoscalars and baryons are also reported. We include some discussion on the $5/2^+$ $Δ$ resonances around 2000 MeV, where we suggest that the $Δ(2000)5/2^+$ resonance, which comes in the PDG from averaging a set of resonances appearing around 1700 MeV and another one around 2200 MeV, corresponds indeed to two distinct resonances. We also report on a hidden charm baryon state around 4400 MeV coming from the interaction of vector mesons and baryons with charm, and how this state has some repercussion in the $J/ψ$ suppression in nuclei. The interaction of $K^*$ in nuclei is also reported and suggestions are made to measure by means of the transparency ratio the huge width in the medium that the theoretical calculations predict. The formalism is extended to $J/ψ$ interaction with nuclei and the transparency ratio for $J/ψ$ photoproduction in nuclei is studied and shown to be a good tool to find possible baryon states which couple to $J/ψN$.

nucl-th↗

arXiv2011

$NDK$, $\bar{K} DN$ and $ND\bar{D}$ molecules

We investigate theoretically baryon systems made of three hadrons which contain one nucleon and one D meson, and in addition another meson, $\bar{D}, K$ or $\bar{K}$. The systems are studied using the Fixed Center Approximation to the Faddeev equations. The study is made assuming scattering of a $K$ or a $\bar{K}$ on a $DN$ cluster, which is known to generate the $Λ_c(2595)$, or the scattering of a nucleon on the $D\bar{D}$ cluster, which has been shown to generate a hidden charm resonance named X(3700). We also investigate the configuration of scattering of $N$ on the $KD$ cluster, which is known to generate the $D_{s0}^*(2317)$. In all cases we find bound states, with the $NDK$ system, of exotic nature, more bound than the $\bar{K} DN$.

hep-ph↗