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Xiu-Li Gao

Publications and source records attributed to Xiu-Li Gao.

5 recordsLinked to original sources

On Compositeness of $D_{s0}^*(2317)$ and its decay to $D_sπ^0$

We demonstrate that the $D_{s0}^{*}(2317)$ can be described as a bound-state pole arising from the coupling between a discrete $c\bar{s}(1^3P_0)$ state and the $DK$ continuum state in the Lee-Friedrichs model. The elementariness and compositeness of the $D_{s0}^{*}(2317)$ are determined to be about $Z:X\approx 51.1 \%:48.9\%$, indicating a nearly equal admixture of compact quark-model state and hadronic molecular components. The decay width of $D_{s0}^{*}(2317)\rightarrow D_s^{+}π^0$ is evaluated within the quark rearrangement framework. The transition $c\bar{s}(1^3P_0)\rightarrow D_sπ^0$ proceeds via the OZI-allowed $c\bar{s}(1^3P_0)-D_sη$ coupling followed by $η-π^0$ mixing, which serves as the primary source of isospin violation in this channel. The coupling between $DK$ and $D_sπ^0$ is computed in a quark rearrangement model, where the isospin violation effect originates from the mass difference between the $D^0K^+$ and $D^+K^0$ thresholds. The parameters of the scheme shares the same ones with those of the underlying potential model and only the vacuum production strength is adjusted to reproduce the physical $D_{s0}^{*}(2317)$ mass. This calculation may shed more insight to the nature of exotic $D_{s0}^{*}(2317)$ state and its isospin-breaking decay properties.

hep-ph

Comparing relativistic and non-relativistic quark pair creation models

We investigate the strong decay properties of light unflavored and strange mesons within a relativistic quark-pair-creation (QPC) framework, and compare the results with those obtained in the conventional non-relativistic QPC model. Our analysis shows that, within the present theoretical and experimental uncertainties, the relativistic QPC model yields predictions for strong decay widths of comparable overall quality to those of the non-relativistic QPC model. This indicates that the non-relativistic QPC approach remains adequate for estimating decay widths in most practical applications. Nevertheless, owing to the inclusion of Lorentz boosts and Wigner rotations, the relativistic QPC model exhibits a stronger suppression of decay amplitudes in the high-energy region. This feature may be useful in studies based on unquenched quark models, where the relativistic QPC coupling could lead to more controlled meson-loop effects and mass shifts.

hep-ph

Updated analysis of charmonium states in a relativized quark potential model

Motivated by recent experimental observations of charmonium(-like) states, we investigate their interpretation as conventional charmonium states within the framework of relativized quark potential model. We find a consistent description of the updated masses of charmonia, bottomonia and some selected charmed mesons, then systematically compute open-charm strong decay widths and electromagnetic transition widths for radially excited charmonium states up to $n=5$. The numerical results show significantly improved agreement with experimental masses and widths. Notably, the newly-observed $χ_{c1}(4010)$ and $χ_{c1}(4274)$ are tentatively associated with the $χ_{c1}(2P)$ and $χ_{c1}(3P)$ respectively, while the $χ_{c0}(4500)$ and $χ_{c0}(4700)$ are interpreted as the $χ_{c0}(4P)$ and $χ_{c0}(5P)$ states. For the controversial $χ_{c1}(3872)$ state, we suggest its potential connection to $χ_{c1}(4010)$, as a two-pole structure due to the $χ_{c1}(2P)$ coupling to $D\bar{D}$ channels. Intriguingly, the predicted mass of $χ_{c0}(2P)$ is about 3851 MeV, diverging from the original estimate of 3916 MeV in the Godfrey and Isgur's work but consistent with non-relativistic potential model predictions. This calculation might provide more insight to the future experimental investigation of charmonium(-like) states.

hep-ph

Scrutinizing $ππ$ scattering in light of recent lattice phase shifts

In this paper, the $IJ=00, 11, 20$ partial wave $ππ$ scattering phase shifts determined by the lattice QCD approach are analyzed by using a novel dispersive solution of the S-matrix, i.e. the PKU representation, in which the unitarity and analyticity of scattering amplitudes are automatically satisfied and the phase shifts are conveniently decomposed into the contributions of the cuts and various poles, including bound states, virtual states and resonances. The contribution of the left-hand cut is estimated by the $SU(2)$ chiral perturbation theory to $\mathcal{O}(p^4)$. The Balanchandran-Nuyts-Roskies relations are considered as constraints to meet the requirements of the crossing symmetry. It is found that the $IJ=00$ $ππ$ scattering phase shifts obtained at $m_π=391$ MeV by Hadron Spectrum Collaboration (HSC) reveal the presence of both a bound state pole and a virtual state pole below the $ππ$ threshold rather than only one bound state pole for the $σ$. To reproduce the lattice phase shifts at $m_π=391$ MeV, a virtual-state pole in the $IJ=20$ channel is found to be necessary in order to balance the left-hand cut effects from the chiral amplitudes. Similar discussions are also carried out for the lattice results with $m_π=236$ MeV from HSC. The observed behaviors of the pole positions with respect to the variation of the pion masses can provide deep insights into our understanding of the dynamical origin of $σ$ resonance.

hep-ph