We discuss recent progress in extracting the excited meson spectrum and radiative transition form factors from lattice QCD.We mention results in the charmonium sector,including the first lattice QCD calculation of rad...We discuss recent progress in extracting the excited meson spectrum and radiative transition form factors from lattice QCD.We mention results in the charmonium sector,including the first lattice QCD calculation of radiative transition rates involving excited charmonium states,highlighting results for high spin and exotic states.We present recent results on a highly excited isovector meson spectrum from dynamical anisotropic lattices.Using carefully constructed operators we show how the continuum spin of extracted states can be reliably identified and confidently extract excited states,states with exotic quantum numbers and states of high spin.This spectrum includes the first spin-four state extracted from lattice QCD.We conclude with some comments on future prospects.展开更多
In this study,the spectroscopic parameters of exotic molecular states composed of mesons containing two heavy quarks(scalar-axial and pseudoscalar-axial meson combinations)are investigated within the QCD sum rules.Our...In this study,the spectroscopic parameters of exotic molecular states composed of mesons containing two heavy quarks(scalar-axial and pseudoscalar-axial meson combinations)are investigated within the QCD sum rules.Our findings reveal that molecular states containing charm quarks do not form bound states,whereas states with b-quarks can form exotic molecular states.This observation has significant implications for understanding the structure of these exotic states.展开更多
We first construct the effective chiral Lagrangians tor the 1^-＋ exotic mesons.With the infrared regularization scheme,we derive the one-loop infrared singular chiral corrections to the π1（1600） mass explicitly.We...We first construct the effective chiral Lagrangians tor the 1^-＋ exotic mesons.With the infrared regularization scheme,we derive the one-loop infrared singular chiral corrections to the π1（1600） mass explicitly.We investigate the variation of the different chiral corrections with the pion mass under two schemes.Hopefully,the explicit non-analytical chiral structures will be helpful for the chiral extrapolation of lattice data from the dynamical lattice QCD simulation of either the exotic light hybrid meson or the tetraquark state.展开更多
In this exploratory study, near-threshold scattering of D and D^-* meson is investigated using lattice QCD with Nf=2+1+1 twisted mass fermion configurations. The calculation is performed in the coupled-channel Lü...In this exploratory study, near-threshold scattering of D and D^-* meson is investigated using lattice QCD with Nf=2+1+1 twisted mass fermion configurations. The calculation is performed in the coupled-channel Lüscher finite-size formalism. The study focuses on the channel with I^G(J^PC)=1^+(1+^+-) where the resonance-like structure Zc(3900) was discovered. We first identify the two most relevant channels and the lattice study is performed in the two-channel scattering model. Combined with the two-channel Ross-Shaw theory, scattering parameters are extracted from the energy levels by solving the generalized eigenvalue problem. Our results for the scattering length parameters suggest that for the particular lattice parameters that we studied, the best fit parameters do not correspond to the peak in the elastic scattering cross-section near the threshold. Furthermore, in the zero-range Ross-Shaw theory, the scenario of a narrow resonance close to the threshold is disfavored beyond the 3σ level.展开更多
Glueballs are investigated through gluonic operators on two N_(f)=2+1RBC/UKQCD gauge ensembles at the physical pion mass.The statistical errors of glueball correlation functions are considerably reduced through the cl...Glueballs are investigated through gluonic operators on two N_(f)=2+1RBC/UKQCD gauge ensembles at the physical pion mass.The statistical errors of glueball correlation functions are considerably reduced through the cluster decomposition error reduction(CDER)method.The Bethe-Salpeter wave functions are obtained for the scalar,tensor,and pseudoscalar glueballs by using spatially extended glueball operators defined through the gauge potential A_(μ)(x)in the Coulomb gauge.These wave functions exhibit similar features of non-relativistic two-gluon systems and are used to optimize the signals of the related correlation functions at the early time regions,where the ground state masses are extracted.These masses are close to those from the quenched approximation and indicate the possible existence of glueballs at the physical point.The resonance feature of glueballs and the mixing with conventional mesons and multi-hadron systems should be considered in a more systematic lattice study.展开更多
文摘We discuss recent progress in extracting the excited meson spectrum and radiative transition form factors from lattice QCD.We mention results in the charmonium sector,including the first lattice QCD calculation of radiative transition rates involving excited charmonium states,highlighting results for high spin and exotic states.We present recent results on a highly excited isovector meson spectrum from dynamical anisotropic lattices.Using carefully constructed operators we show how the continuum spin of extracted states can be reliably identified and confidently extract excited states,states with exotic quantum numbers and states of high spin.This spectrum includes the first spin-four state extracted from lattice QCD.We conclude with some comments on future prospects.
文摘In this study,the spectroscopic parameters of exotic molecular states composed of mesons containing two heavy quarks(scalar-axial and pseudoscalar-axial meson combinations)are investigated within the QCD sum rules.Our findings reveal that molecular states containing charm quarks do not form bound states,whereas states with b-quarks can form exotic molecular states.This observation has significant implications for understanding the structure of these exotic states.
基金Supported by National Natural Science Foundation of China(11222547,11175073,11575008)and 973 Programsupported by the National Youth Top-Level Talent Support Program(“Thousand Talents Scheme”)
文摘We first construct the effective chiral Lagrangians tor the 1^-＋ exotic mesons.With the infrared regularization scheme,we derive the one-loop infrared singular chiral corrections to the π1（1600） mass explicitly.We investigate the variation of the different chiral corrections with the pion mass under two schemes.Hopefully,the explicit non-analytical chiral structures will be helpful for the chiral extrapolation of lattice data from the dynamical lattice QCD simulation of either the exotic light hybrid meson or the tetraquark state.
基金Supported in part by the Ministry of Science and Technology of China(MSTC)under 973 project"Systematic studies on light hadron spectroscopy"(2015CB856702)supported in part by the DFG and the NSFC through funds provided to the Sino-Germen CRC 110"Symmetries and the Emergence of Structure in QCD",DFG grant no.TRR 110 and NSFC(11621131001)+2 种基金supported in part by the National Science Foundation of China(NSFC)(11775229,11875169)the Youth Innovation Promotion Association of CAS(2015013)the support from the Key Research Program of the Chinese Academy of Sciences(XDPB09)
文摘In this exploratory study, near-threshold scattering of D and D^-* meson is investigated using lattice QCD with Nf=2+1+1 twisted mass fermion configurations. The calculation is performed in the coupled-channel Lüscher finite-size formalism. The study focuses on the channel with I^G(J^PC)=1^+(1+^+-) where the resonance-like structure Zc(3900) was discovered. We first identify the two most relevant channels and the lattice study is performed in the two-channel scattering model. Combined with the two-channel Ross-Shaw theory, scattering parameters are extracted from the energy levels by solving the generalized eigenvalue problem. Our results for the scattering length parameters suggest that for the particular lattice parameters that we studied, the best fit parameters do not correspond to the peak in the elastic scattering cross-section near the threshold. Furthermore, in the zero-range Ross-Shaw theory, the scenario of a narrow resonance close to the threshold is disfavored beyond the 3σ level.
基金Supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDB34030300,XDPB15)the National Key Research and Development Program of China(2020YFA0406400)+1 种基金the National Natural Science Foundation of China(NNSFC)under Grants(11935017,12070131001)(CRC 110 by DFG and NNSFC)supported in part by a NSFC-DFG joint grant(12061131006 and SCHA458/22)。
文摘Glueballs are investigated through gluonic operators on two N_(f)=2+1RBC/UKQCD gauge ensembles at the physical pion mass.The statistical errors of glueball correlation functions are considerably reduced through the cluster decomposition error reduction(CDER)method.The Bethe-Salpeter wave functions are obtained for the scalar,tensor,and pseudoscalar glueballs by using spatially extended glueball operators defined through the gauge potential A_(μ)(x)in the Coulomb gauge.These wave functions exhibit similar features of non-relativistic two-gluon systems and are used to optimize the signals of the related correlation functions at the early time regions,where the ground state masses are extracted.These masses are close to those from the quenched approximation and indicate the possible existence of glueballs at the physical point.The resonance feature of glueballs and the mixing with conventional mesons and multi-hadron systems should be considered in a more systematic lattice study.
