Following over 20 years of research,a direct measurement of the QGP temperature has been achieved at Relativistic Heavy-Ion Collider(RHIC),free from the blue-shift effect and contamination from strong interactions.Thi...Following over 20 years of research,a direct measurement of the QGP temperature has been achieved at Relativistic Heavy-Ion Collider(RHIC),free from the blue-shift effect and contamination from strong interactions.This viewpoint discusses a recent measurement of the QGP temperature at different stages at the Solenoidal Tracker at RHIC(STAR),which used e^(+)e^(-)pairs as penetrating probes.展开更多
Leveraging high-precision lattice QCD data on the equation of state and baryon number susceptibility at a vanishing chemical potential,we constructed a Bayesian holographic QCD model and systematically analyzed the th...Leveraging high-precision lattice QCD data on the equation of state and baryon number susceptibility at a vanishing chemical potential,we constructed a Bayesian holographic QCD model and systematically analyzed the thermodynamic properties of heavy quarkonium in QCD matter under varying temperatures and chemical potentials.We computed the quark-antiquark interquark distance,potential energy,entropy,binding energy,and internal energy.We present detailed posterior distribution results of the thermodynamic quantities of heavy quarkonium,including maximum a posteriori(MAP)value estimates and 95%confidence levels(CL).Through numerical simulations and theoretical analysis,we find that an increase in the temperature and chemical potential reduces the quark distance,thereby facilitating the dissociation of heavy quarkonium and leading to a suppressed potential energy.The increase in temperature and chemical potential also raises the entropy and entropy force,further accelerating the dissociation of heavy quarkonium.The calculated results of binding energy indicate that a higher temperature and chemical potential enhance the tendency of heavy quarkonium to dissociate into free quarks.The internal energy also increases with rising temperature and chemical potential.These findings provide significant theoretical insights into the properties of strongly interacting matter under extreme conditions and lay a solid foundation for the interpretation and validation of future experimental data.Finally,we also present the results for the free energy,entropy,and internal energy of a single quark.展开更多
The transverse single-spin asymmetry forρ^(0) production in semi-inclusive deep inelastic scattering was recently reported by the COMPASS Collaboration.Using the Sivers function extracted from pion and kaon productio...The transverse single-spin asymmetry forρ^(0) production in semi-inclusive deep inelastic scattering was recently reported by the COMPASS Collaboration.Using the Sivers function extracted from pion and kaon productions,we perform a calculation of the Sivers asymmetry within the transverse momentum-dependent factorization.Our results are consistent with the COMPASS data,supporting the universality of the Sivers function in the semi-inclusive deep inelastic scattering process for different final-state hadrons within current experimental uncertainties.While different parametrizations of the Sivers function from global analyses allow describing the data equally well,we obtain very different predictions on the Sivers asymmetry ofρand K^(*)productions at electron-ion colliders,which therefore are expected to provide further constraints.展开更多
In this paper,we study the ρ-meson electromagnetic form factors(EMFFs)within the framework of the light-front quark model.The physical form factors G_(C,M,Q)(Q^(2))of the ρ-meson,as well as the charged square radius...In this paper,we study the ρ-meson electromagnetic form factors(EMFFs)within the framework of the light-front quark model.The physical form factors G_(C,M,Q)(Q^(2))of the ρ-meson,as well as the charged square radius<r^(2)>,the magnetic moment μ,and the quadrupole moment Q,are calculated,which describe the behaviors of EMFFs at zero momentum transfer.Using the type-Ⅱ replacement,we find that the zero-mode does contribute zero to the matrix element S_(00)^(+).It is found that the“M→M_(0)”replacement improves the angular condition remarkably,which permits different prescriptions of ρ-meson EMFFs to give the consistent results.The residual tiny violation of angular condition needs other explanations beyond the zero-mode contributions.Our results indicate that the relativistic effects or interaction internal structure are weaken in the zero-binding limit.This work is also applicable to other spin-1 particles.展开更多
We investigate the e^(+)e^(-)→∑∑^(-) and e^(+)e^(-)→Λ∑^(-)reactions within the extended vector meson dominance model.In addition to the ground state mesons ρ and ω,we consider the contributions of the excited ...We investigate the e^(+)e^(-)→∑∑^(-) and e^(+)e^(-)→Λ∑^(-)reactions within the extended vector meson dominance model.In addition to the ground state mesons ρ and ω,we consider the contributions of the excited states ρ(3D),ω(3D),φ(3D),and ρ(2850).It is found that the current experimental data on the Σ electromagnetic form factors in timelike region can be well reproduced.The Φ(3D) resonance is essential to the near thresholdenhancement of the cross-section for the e^(+)e^(-)→∑∑^(-) reaction. Furthermore, in the e^(+)e^(-)→Λ∑^(-) reaction, theρ(3D) is important to get a good fit for the experimental results.展开更多
The X(3872)is theoretically predicted to have a spin-0 partner state denoted as X_(0).Assuming the X_(0)as a molecular bound state,we calculate the decay widths of X_(0)→VV and X_(0)→PP(V and P stand for light vecto...The X(3872)is theoretically predicted to have a spin-0 partner state denoted as X_(0).Assuming the X_(0)as a molecular bound state,we calculate the decay widths of X_(0)→VV and X_(0)→PP(V and P stand for light vector and pseudoscalar mesons,respectively)via intermediate charmed meson loops.Three different configurations of the X_(0),i.e.,pure neutral components(θ=0),isospin singlet(θ=π/4),and pure charged components(θ=π/2),are investigated.Within a commonly accepted range of the model parameterα,the predicted decay widths of X_(0)→VV are on the order of a few hundred keV,while the decay widths of X_(0)→PP can reach several MeV.The X_(0)→ρρandππhave larger decay rates.The relative width ratios between the channels are nearly model-independent.Moreover,among those channels only with isovector or isoscalar mesons,the relevant ratios are also independent of the phase angle.The predicted ratios are helpful for searching the X_(0)in the future experiments at BESIII and Belle II.展开更多
Recently,taking advantage of the large volume of data collected by the detector,the BESIII International Collaboration successfully measured the decay constant for the charmed meson D+-with the best precision to date....Recently,taking advantage of the large volume of data collected by the detector,the BESIII International Collaboration successfully measured the decay constant for the charmed meson D+-with the best precision to date.As an unstable particle,the charmed meson D+can decay via many different pathways,each with a different possibility.In the process of the decay,its constituent heavy charm quark can transform itself into other particles,thereby diverting the subsequent decay cascade into a different pathway or a different decay network.展开更多
Decays of charmonium into hyperon and antihyperon pairs provide a pristine laboratory for exploring hyperon properties,such as their polarization and decay parameters,and for conducting tests of fundamental symmetries...Decays of charmonium into hyperon and antihyperon pairs provide a pristine laboratory for exploring hyperon properties,such as their polarization and decay parameters,and for conducting tests of fundamental symmetries.This brief review highlights the significant progress made in precise tests of CP symmetry at BESIII using entangled hyperon-antihyperon pairs。展开更多
Inspired by the X(4140)structure reported in the J/ψφsystem by the CDF experiment in 2009,a series of searches have been carried out in theJ/ψφand J/ψK channels,leading to the claim of ten structures in the B→J...Inspired by the X(4140)structure reported in the J/ψφsystem by the CDF experiment in 2009,a series of searches have been carried out in theJ/ψφand J/ψK channels,leading to the claim of ten structures in the B→J/ψφK system.This article provides a comprehensive review of experimental developments,from the initial evidence of X(4140)at CDF to the amplitude analyses and diffractive process investigations by the LHCb experiment,as well as theoretical interpretations of these states.A triplet of J^(PC)=1++states with relatively large mass splittings[about 200MeV(natural units are adopted)]has been identified in the J/ψφsystem by LHCb.Their mass-squared values align approximately linearly with a possible radial quantum number,suggesting that the triplet may represent a radially excited family.For X(4140),the first state in the triplet,its width reported by LHCb is inconsistent with that measured by other experiments,and possible reasons for this discrepancy are discussed.A potential connection between an excess at 4.35 GeV in the J/ψφmass spectrum reported by the Belle experiment through a two-photon process and a potential spin-2 excess in the LHCb data is also investigated.In addition,potential parallels between the J/ψφand J/ψJ/ψsystems,both composed of two vector mesons,are discussed.The continued interest in,and complexity of,these systems underscore the necessity of further experimental exploration with increased statistical precision across a variety of experiments,particularly those with relatively flat efficiency across the Dalitz plot.The J/ψω,φφ,ρω,andρφsystems are mentioned,and the prospects for the J/ψγandγγsystems,are also highlighted.展开更多
The significance of laser-driven polarized beam acceleration has been increasingly recognized in recent years.We propose an efficient method for generating polarized proton beams from a pre-polarized hydrogen halide g...The significance of laser-driven polarized beam acceleration has been increasingly recognized in recent years.We propose an efficient method for generating polarized proton beams from a pre-polarized hydrogen halide gas jet,utilizing magnetic vortex acceleration enhanced by a laser-driven plasma bubble.When a petawatt laser pulse passes through a pre-polarized gas jet,a bubble-like ultra-nonlinear plasma wave is formed.As a portion of the particles constituting this wave,background protons are swept by the acceleration field of the bubble and oscillate significantly along the laser propagation axis.Some of the pre-accelerated protons in the plasma wave are trapped by the acceleration field at the rear side of the target.This acceleration field is intensified by the transverse expansion of the laser-driven magnetic vortex,resulting in energetic polarized proton beams.The spin of energetic protons is determined by their precession within the electromagnetic field,which is described using the Thomas-Bargmann-Michel-Telegdi equation in analytical models and particle-in-cell simulations.Multidimensional simulations reveal that monoenergetic proton beams with an energy of hundreds of MeV,a beam charge of hundreds of pC,and a beam polarization of tens of percent can be produced at laser powers of several petawatts.Such laser-driven polarized proton beams have promise for application in polarized beam colliders,where they can be utilized to investigate particle interactions and to explore the properties of matter under extreme conditions.展开更多
文摘Following over 20 years of research,a direct measurement of the QGP temperature has been achieved at Relativistic Heavy-Ion Collider(RHIC),free from the blue-shift effect and contamination from strong interactions.This viewpoint discusses a recent measurement of the QGP temperature at different stages at the Solenoidal Tracker at RHIC(STAR),which used e^(+)e^(-)pairs as penetrating probes.
基金supported in part by the National Key Research and Development Program of China(No.2022YFA1604900)the National Natural Science Foundation of China(NSFC)(Nos.12405154,12235016,12221005,12435009,12275104,92570117)+7 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB34030000)the Fundamental Research Funds for the Central UniversitiesOpen fund for Key Laboratories of the Ministry of Education(No.QLPL2024P01)CUHK-Shenzhen University Development Fund(Nos.UDF01003041 and UDF03003041)Shenzhen Peacock Fund(No.2023TC0007)Ministry of Science and Technology of China(No.2024YFA1611004)the European Union–Next Generation EU through the research(No.P2022Z4P4B)“SOPHYA-Sustainable Optimized PHYsics Algorithms:fundamental physics to build an advanced society”under the program PRIN 2022 PNRR of the Italian Ministero dell’Universitàe Ricerca(MUR)。
文摘Leveraging high-precision lattice QCD data on the equation of state and baryon number susceptibility at a vanishing chemical potential,we constructed a Bayesian holographic QCD model and systematically analyzed the thermodynamic properties of heavy quarkonium in QCD matter under varying temperatures and chemical potentials.We computed the quark-antiquark interquark distance,potential energy,entropy,binding energy,and internal energy.We present detailed posterior distribution results of the thermodynamic quantities of heavy quarkonium,including maximum a posteriori(MAP)value estimates and 95%confidence levels(CL).Through numerical simulations and theoretical analysis,we find that an increase in the temperature and chemical potential reduces the quark distance,thereby facilitating the dissociation of heavy quarkonium and leading to a suppressed potential energy.The increase in temperature and chemical potential also raises the entropy and entropy force,further accelerating the dissociation of heavy quarkonium.The calculated results of binding energy indicate that a higher temperature and chemical potential enhance the tendency of heavy quarkonium to dissociate into free quarks.The internal energy also increases with rising temperature and chemical potential.These findings provide significant theoretical insights into the properties of strongly interacting matter under extreme conditions and lay a solid foundation for the interpretation and validation of future experimental data.Finally,we also present the results for the free energy,entropy,and internal energy of a single quark.
基金supported by the National Key R&D Program of China(Grant No.2024YFA1611004)the National Natural Science Foundation of China(Grant Nos.12175117,12475084,and 12321005)the Shandong Province Natural Science Foundation(Grant Nos.ZFJH202303 and ZR2024MA012)。
文摘The transverse single-spin asymmetry forρ^(0) production in semi-inclusive deep inelastic scattering was recently reported by the COMPASS Collaboration.Using the Sivers function extracted from pion and kaon productions,we perform a calculation of the Sivers asymmetry within the transverse momentum-dependent factorization.Our results are consistent with the COMPASS data,supporting the universality of the Sivers function in the semi-inclusive deep inelastic scattering process for different final-state hadrons within current experimental uncertainties.While different parametrizations of the Sivers function from global analyses allow describing the data equally well,we obtain very different predictions on the Sivers asymmetry ofρand K^(*)productions at electron-ion colliders,which therefore are expected to provide further constraints.
基金supported by the National Natural Science Foundation of China(Grant Nos.11875122,12175025,and 12147102)Tongling University Talent Program(Grant No.R23100)。
文摘In this paper,we study the ρ-meson electromagnetic form factors(EMFFs)within the framework of the light-front quark model.The physical form factors G_(C,M,Q)(Q^(2))of the ρ-meson,as well as the charged square radius<r^(2)>,the magnetic moment μ,and the quadrupole moment Q,are calculated,which describe the behaviors of EMFFs at zero momentum transfer.Using the type-Ⅱ replacement,we find that the zero-mode does contribute zero to the matrix element S_(00)^(+).It is found that the“M→M_(0)”replacement improves the angular condition remarkably,which permits different prescriptions of ρ-meson EMFFs to give the consistent results.The residual tiny violation of angular condition needs other explanations beyond the zero-mode contributions.Our results indicate that the relativistic effects or interaction internal structure are weaken in the zero-binding limit.This work is also applicable to other spin-1 particles.
基金partly supported by the National Key R&D Program of China(Grant No.2023YFA1606703)the National Natural Science Foundation of China(Grant Nos.12435007,12361141819,12275185,and 12335002)。
文摘We investigate the e^(+)e^(-)→∑∑^(-) and e^(+)e^(-)→Λ∑^(-)reactions within the extended vector meson dominance model.In addition to the ground state mesons ρ and ω,we consider the contributions of the excited states ρ(3D),ω(3D),φ(3D),and ρ(2850).It is found that the current experimental data on the Σ electromagnetic form factors in timelike region can be well reproduced.The Φ(3D) resonance is essential to the near thresholdenhancement of the cross-section for the e^(+)e^(-)→∑∑^(-) reaction. Furthermore, in the e^(+)e^(-)→Λ∑^(-) reaction, theρ(3D) is important to get a good fit for the experimental results.
基金supported by the National Natural Science Foundation of China(Grant Nos.12475081 and 12105153)the Natural Science Foundation of Shandong Province(Grant Nos.ZR2021MA082 and ZR2022ZD26)Taishan Scholar Project of Shandong Province(Grant No.tsqn202103062).
文摘The X(3872)is theoretically predicted to have a spin-0 partner state denoted as X_(0).Assuming the X_(0)as a molecular bound state,we calculate the decay widths of X_(0)→VV and X_(0)→PP(V and P stand for light vector and pseudoscalar mesons,respectively)via intermediate charmed meson loops.Three different configurations of the X_(0),i.e.,pure neutral components(θ=0),isospin singlet(θ=π/4),and pure charged components(θ=π/2),are investigated.Within a commonly accepted range of the model parameterα,the predicted decay widths of X_(0)→VV are on the order of a few hundred keV,while the decay widths of X_(0)→PP can reach several MeV.The X_(0)→ρρandππhave larger decay rates.The relative width ratios between the channels are nearly model-independent.Moreover,among those channels only with isovector or isoscalar mesons,the relevant ratios are also independent of the phase angle.The predicted ratios are helpful for searching the X_(0)in the future experiments at BESIII and Belle II.
文摘Recently,taking advantage of the large volume of data collected by the detector,the BESIII International Collaboration successfully measured the decay constant for the charmed meson D+-with the best precision to date.As an unstable particle,the charmed meson D+can decay via many different pathways,each with a different possibility.In the process of the decay,its constituent heavy charm quark can transform itself into other particles,thereby diverting the subsequent decay cascade into a different pathway or a different decay network.
基金supported by the National Natural Science Foundation of China(Grant No.12225509),the National Natural Science Foundation of China(Grant No.12247101)the Polish National Science Centre(Grant No.2024/53/B/ST2/00975)+2 种基金the Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2024-jdzx06)the Natural Science Foundation of Gansu Province(Grant No.22JR5RA389)the‘111 Center’under Grant No.B20063。
文摘Decays of charmonium into hyperon and antihyperon pairs provide a pristine laboratory for exploring hyperon properties,such as their polarization and decay parameters,and for conducting tests of fundamental symmetries.This brief review highlights the significant progress made in precise tests of CP symmetry at BESIII using entangled hyperon-antihyperon pairs。
基金partially supported by the Natural Science Foundation of China(Grant Nos.12075123,12061141002,and 12535004)the Ministry of Science and Technology of China(Grant Nos.2023YFA1605804 and 2024YFA1610501)。
文摘Inspired by the X(4140)structure reported in the J/ψφsystem by the CDF experiment in 2009,a series of searches have been carried out in theJ/ψφand J/ψK channels,leading to the claim of ten structures in the B→J/ψφK system.This article provides a comprehensive review of experimental developments,from the initial evidence of X(4140)at CDF to the amplitude analyses and diffractive process investigations by the LHCb experiment,as well as theoretical interpretations of these states.A triplet of J^(PC)=1++states with relatively large mass splittings[about 200MeV(natural units are adopted)]has been identified in the J/ψφsystem by LHCb.Their mass-squared values align approximately linearly with a possible radial quantum number,suggesting that the triplet may represent a radially excited family.For X(4140),the first state in the triplet,its width reported by LHCb is inconsistent with that measured by other experiments,and possible reasons for this discrepancy are discussed.A potential connection between an excess at 4.35 GeV in the J/ψφmass spectrum reported by the Belle experiment through a two-photon process and a potential spin-2 excess in the LHCb data is also investigated.In addition,potential parallels between the J/ψφand J/ψJ/ψsystems,both composed of two vector mesons,are discussed.The continued interest in,and complexity of,these systems underscore the necessity of further experimental exploration with increased statistical precision across a variety of experiments,particularly those with relatively flat efficiency across the Dalitz plot.The J/ψω,φφ,ρω,andρφsystems are mentioned,and the prospects for the J/ψγandγγsystems,are also highlighted.
基金supported by the National Natural Science Foundation of China(Grant Nos.12075081 and 12404395)the Innovation Group Project of the Natural Science Foundation of Hubei Province of China(Grant No.2024AFA038)Bin Liu acknowledges the support of Guangdong High Level Innovation Research Institute Project,Grant No.2021B0909050006.
文摘The significance of laser-driven polarized beam acceleration has been increasingly recognized in recent years.We propose an efficient method for generating polarized proton beams from a pre-polarized hydrogen halide gas jet,utilizing magnetic vortex acceleration enhanced by a laser-driven plasma bubble.When a petawatt laser pulse passes through a pre-polarized gas jet,a bubble-like ultra-nonlinear plasma wave is formed.As a portion of the particles constituting this wave,background protons are swept by the acceleration field of the bubble and oscillate significantly along the laser propagation axis.Some of the pre-accelerated protons in the plasma wave are trapped by the acceleration field at the rear side of the target.This acceleration field is intensified by the transverse expansion of the laser-driven magnetic vortex,resulting in energetic polarized proton beams.The spin of energetic protons is determined by their precession within the electromagnetic field,which is described using the Thomas-Bargmann-Michel-Telegdi equation in analytical models and particle-in-cell simulations.Multidimensional simulations reveal that monoenergetic proton beams with an energy of hundreds of MeV,a beam charge of hundreds of pC,and a beam polarization of tens of percent can be produced at laser powers of several petawatts.Such laser-driven polarized proton beams have promise for application in polarized beam colliders,where they can be utilized to investigate particle interactions and to explore the properties of matter under extreme conditions.
