No Arabic abstract
We study the renormalization of the properties of low lying charm and hidden charm scalar mesons in a nuclear medium, concretely of the D_{s0}(2317) and the theoretical hidden charm state X(3700). We find that for the D_{s0}(2317), with negligible width at zero density, the width becomes about 100 MeV at normal nuclear matter density, while in the case of the X(3700) the width becomes as large as 200 MeV. We discuss the origin of this new width and trace it to reactions occurring in the nucleus, while offering a guideline for future experiments testing these changes. We also show how those medium modifications will bring valuable information on the nature of the scalar resonances and the mechanisms of the interaction of D mesons with nucleons and nuclei.
In this presentation I explain our framework for dynamically generating resonances from the meson meson interaction. Our model generates many poles in the T-matrix which are associated with known states, while at the same time new states are predicted.
We calculate spatial correlation functions of in-medium mesons consisting of strange--anti-strange, strange--anti-charm and charm--anti-charm quarks in (2+1)-flavor lattice QCD using the highly improved staggered quark action. A comparative study of the in-medium modifications of mesons with different flavor contents is performed. We observe significant in-medium modifications for the $phi$ and $D_s$ meson channels already at temperatures around the chiral crossover region. On the other hand, for the $J/psi$ and $eta_c$ meson channels in-medium modifications remain relatively small around the chiral crossover region and become significant only above 1.3 times the chiral crossover temperature.
We present the first predictions for sub-threshold open charm and charmonium production in nuclear collisions. The production mechanism is driven by multi-step scatterings of nucleons and their resonance states, accumulating sufficient energy for the production of $J/Psi$, $Lambda_c + overline{D}$ and $D+overline{D}$. Our results are of particular importance for the CBM experiment at FAIR, as they indicate that already at the SIS100 accelerator one can expect a significant number of charmed hadrons to be produced. This opens new possibilities to explore charm dynamics and the formation of charmed nuclei.
We discuss recent experimental results on the modification of hadron properties in a nuclear medium. Particular emphasis is placed on an $omega$ production experiment performed by the CBELSA/TAPS collaboration at the ELSA accelerator. The data shows a smaller $omega$ meson mass together with a significant increase of its width in the nuclear medium.
In this article, we study the masses and pole residues of the pseudoscalar-diquark-pseudoscalar-antidiquark type and vector-diquark-vector-antidiquark type scalar hidden-charm $cubar{c}bar{d}$ ($cubar{c}bar{s}$) tetraquark states with QCD sum rules by taking into account the contributions of the vacuum condensates up to dimension-10 in the operator product expansion. The predicted masses can be confronted with the experimental data in the future. Possible decays of those tetraquark states are also discussed.