arXiv subjects
Publications and source records attributed to Xing-Hua Wu.
We examine new tests for (non-)extremal Reissner-Nordström/Conformal field theory correspondences (RN/CFT) in this paper. The decay rate of the charged scalar wave sourced by an orbiting star around the black hole is computed and is compared with the decay rate computed in the corresponding CFT. We find that precise matches are achieved.
In this paper we compute the decay rates of massless scalar waves excited by a star circularly orbiting around the non-extremal (general) and extremal BTZ black holes. These decay rates are compared with the corresponding quantities computed in the corresponding dual conformal field theories respectively. We find that matches are achieved in both cases.
In the quasilinear Regge trajectory ansatz, some useful linear mass inequalities, quadratic mass inequalities and quadratic mass equalities are derived for mesons and baryons. Based on these relations, mass ranges of some mesons and baryons are given. The masses of bc-bar and ss-bar belonging to the pseudoscalar, vector and tensor meson multiplets are also extracted. The J^P of the baryon Xi_cc(3520) is assigned to be 1/2^+. The numerical values for Regge slopes and intercepts of the 1/2^+ and 3/2^+ SU(4) baryon trajectories are extracted and the masses of the orbital excited baryons lying on the 1/2^+ and 3/2^+ trajectories are estimated. The J^P assignments of baryons Xi_c(2980), Xi_c(3055), Xi_c(3077) and Xi_c(3123) are discussed. The predictions are in reasonable agreement with the existing experimental data and those suggested in many other different approaches. The mass relations and the predictions may be useful for the discovery of the unobserved meson and baryon states and the J^P assignment of these states.
In this work we evaluate the cross section of the process $e^+e^-\to J/ψη_c$ at energy $\sqrt{s}\approx 10.6$ GeV in the Bethe-Salpeter formalism. To simplify our calculation, the heavy quark limit is employed. Without taking the beyond-leading-order contribution(s) into account, the cross section calculated in this scenario is comparable with the experimental data. We also present our prediction for the cross section of double bottomonium production $e^+e^-\to Υ(1S)η_b$ for the energy range of $\sqrt{s}\approx (25 \hbox{-} 30)$ GeV which may be experimentally tested, even though there is no facility of this range available at present yet.
In this paper we study the properties of diquarks (composed of $u$ and/or $d$ quarks) in the Bethe-Salpeter formalism under the covariant instantaneous approximation. We calculate their BS wave functions and study their effective interaction with the pion. Using the effective coupling constant among the diquarks and the pion, in the heavy quark limit $m_Q\to\infty$, we calculate the decay widths of $Σ_Q^{(*)}$ ($Q=c,b$) in the BS formalism under the covariant instantaneous approximation and then give predictions of the decay widths $Γ(Σ_b^{(*)}\toΛ_b+π)$.
We study the possible bound states of the $K\bar K$ system in the Bethe-Salpeter formalism in the ladder and instantaneous approximations. We find that the bound states exist. However, these bound states have very small decay widths. Therefore, besides the possible $K\bar K$ component, there may be some other structures in the observed $f_0(980)$ and $a_0(980)$ .
Twist-3 distribution amplitudes of the pion and kaon are studied in this paper. We calculate the fist several moments for the twist-3 distribution amplitudes (ϕ_{p,σ}^πand ϕ_{p,σ}^K) of the pion and kaon by applying the QCD sum rules. Our results show that, (i) the first three moments of ϕ_p^K and the first two moments of ϕ_p^πand ϕ_σ^{π,K} of the pion and kaon can be obtained with 30% uncertainty; (ii) the fourth moment of the ϕ_p^πand the second moment of the ϕ_σ^K can be obtained when the uncertainty are relaxed to 35%; (iii) the fourth moment of the ϕ_σ^πcan be obtained only when the uncertainty are relaxed to 40%; (iv) we have m_{0π}^p=1.10\pm 0.08 {\rm GeV} and m_{0K}^p=1.25\pm 0.15 {\rm GeV} after including the α_s-corrections to the perturbative part. These moments will be helpful for constructing the twist-3 wave functions of the pion and kaon.
We apply the background field method to calculate the moments of the pion two-particles twist-3 distribution amplitude (DA) $ϕ_p(ξ)$ in QCD sum rules. In this paper,we do not use the equation of motion for the quarks inside the pion since they are not on shell and introduce a new parameter $m_0^p$ to be determined. We get the parameter $m_0^p\approx1.30GeV$ in this approach. If assuming the expansion of $ϕ_p(ξ)$ in the series in Gegenbauer polynomials $C_n^{1/2}(ξ)$, one can obtain its approximate expression which can be determined by its first few moments.
We derive an expression for the $B\toπ$ transition form factor only depending the twist-3 distribution amplitudes by choosing an adequate chiral current correlator in the light-cone QCD sum rules. Our result show that the contribution from the twist-3 distribution amplitudes to the $f_{Bπ}^+(q^2)$ give a constraint on the twist-3 light-cone distribution amplitude.