We study the production of the X(6900)in the ultra-peripheral heavy ion collisions at the LHC energy region.The potential quantum numbers of X(6900)could be 0^(±+)and 2^(±+).We find that the transverse momen...We study the production of the X(6900)in the ultra-peripheral heavy ion collisions at the LHC energy region.The potential quantum numbers of X(6900)could be 0^(±+)and 2^(±+).We find that the transverse momentum and the polar angle distributions of X(6900)can be used to distinguish these four potential quantum numbers.These characteristic distributions originate from linearly polarized photons emitted by relativistic nuclei and can be measured by further LHC experiments.展开更多
High multipole electromagnetic transitions are rare in nature.The highest-multipole transition observed in atomic nuclei is the electric hexacontatetrapole E6 transition from the T_(1/2)=2.54(2)-min J^(π)=1_(9/2)-iso...High multipole electromagnetic transitions are rare in nature.The highest-multipole transition observed in atomic nuclei is the electric hexacontatetrapole E6 transition from the T_(1/2)=2.54(2)-min J^(π)=1_(9/2)-isomer to the 7/2^(-)ground state in^(53)Fe with an angular momentum change of six units.In the present work,we performed ab initio calculations for this unique case by employing chiral effective field theory(EFT)forces.The in-medium similarity renormalization group is used to derive the valence-space effective Hamiltonian and multipolar transition operators.Bare nucleon charges were used in all the multipolar transition rate calculations,providing good agreement with the experimental data.The valence space takes the full fp shell.In^(53)Fe,the low-lying states were dominated by the 0f_(7/2)component.Two different versions of the chiral EFT two-plus three-nucleon interaction were used to test the dependence on the interaction used.We also tested the convergence of the transition rate calculations against the harmonic oscillator parameter hΩand basis truncations e_(max)and E_(3max)for twoand three-nucleon forces,respectively.展开更多
We present a concise review of the vector charmonium state ψ(4230), which was originally labelled as Y(4260)in the literature. As one of the earliest candidates for a quantum chromodynamics exotic states, its interpr...We present a concise review of the vector charmonium state ψ(4230), which was originally labelled as Y(4260)in the literature. As one of the earliest candidates for a quantum chromodynamics exotic states, its interpretation has initiated various ideas about possible manifestations of non-perturbative mechanisms in the charmonium mass regime. In this short article we briefly review the experimental status of ψ(4230) and discuss possible theoretical interpretations. We will focus on four broadly investigated scenarios, i.e., tetraquark, hybrid, hadro-quarkonium,and hadronic molecule, and highlight the key issues based on these approaches. Crucial experimental observables,e.g., mass position, lineshapes, di-lepton decay width Γ_(ee), production rates in B meson decays, dominant hadronic decay patterns, and the potential 1^(-+)and 0^(--)exotic partners, are assessed, which can provide crucial structure information for understanding this mysterious state.展开更多
We argue that the hypothesis that positive-parity charm meson resonances exhibit a compact tetraquark structure has some clear tension with recent lattice results for the S-waveπD system for an SU(3)flavor symmetric ...We argue that the hypothesis that positive-parity charm meson resonances exhibit a compact tetraquark structure has some clear tension with recent lattice results for the S-waveπD system for an SU(3)flavor symmetric setting.In particular,we show that such a diquark–anti-diquark tetraquark scenario would call for the presence of a state in the flavor[15]representation,not seen in the lattice analysis.Moreover,we show that analogous lattice data in the axial-vector channel are even more sensitive to the internal structure of these very interesting states.展开更多
Hypernuclei,nuclei containing one or more hyperons,serve as unique laboratories for probing the non-perturbative quantum chromodynamics(QCD).Recent progress in hypernuclear physics,driven by advanced experimental tech...Hypernuclei,nuclei containing one or more hyperons,serve as unique laboratories for probing the non-perturbative quantum chromodynamics(QCD).Recent progress in hypernuclear physics,driven by advanced experimental techniques and theoretical innovations,is briefly reviewed with a focus on key findings and unresolved challenges,such as the precise determination of the hypertriton binding energy,investigations of charge symmetry breaking in mirror hypernuclei,and the search for exotic systems,including the neutral nnΛstate.Experimental breakthroughs,including invariant-mass analyses and femtoscopy studies in heavy-ion collisions,as well as high-resolutionγ-spectroscopy,have enabled precise studies of light hypernuclei and offered critical insights into the hyperon–nucleon interaction.Theoretical progress,including ab initio calculations based on chiral effective field theory and lattice QCD,has further enhanced our understanding of hyperon–nucleon and hyperon–hyperon interactions.展开更多
We studied the energy partition between two well-separated fission fragments associated with the partition of nucleons owing to quantum entanglement.This is different from most fission models that invoke an explicit s...We studied the energy partition between two well-separated fission fragments associated with the partition of nucleons owing to quantum entanglement.This is different from most fission models that invoke an explicit statistical partition of excitation energies.The dynamical fission evolution is described within the time-dependent Hartree-Fock+BCS framework.Excitation energies of isotopic fission fragments were obtained using the particle number projection method after the dynamical splitting of^(238)U.The resulting excitation energies of the light and heavy fragments are consistent with the appearance of sawtooth structures.We found that the pairing correlation strengths have a significant influence on the partition of the excitation energies.Furthermore,the excitation energies of isotopic fragments increase with increasing neutron number,implying the suppression of the production of neutron-rich beams in rare-isotope beam facilities.展开更多
The full configuration interaction quantum Monte Carlo(FCIQMC)method,originally developed in quantum chemistry,has also been successful for both molecular and condensed matter systems.Another natural extension of this...The full configuration interaction quantum Monte Carlo(FCIQMC)method,originally developed in quantum chemistry,has also been successful for both molecular and condensed matter systems.Another natural extension of this methodology is its application to nuclear structure calculations.We developed an FCIQMC approach to study nuclear systems.To validate this method,we applied FCIQMC to a small model space,where the standard shell model remains computationally feasible.Specifically,we performed calculations for?ωisotopes using pf-shell GXPF1A interaction and compared the results with those obtained from the standard shell model calculations.To further demonstrate the capabilities of the FCIQMC,we investigated its performance in systems exhibiting strong correlations,where conventional nuclear structure models are less effective.Using an artificially constructed strongly correlated system with a modified GXPF1A interaction,our calculations revealed that FCIQMC delivered superior results compared to many existing methods.Finally,we applied FCIQMC to Fe isotopes in the sdpf-shell model space,showing its potential to perform accurate calculations in large model spaces that are inaccessible to the shell model because of the limitations of current computational resources.展开更多
Exotic hadrons,beyond the conventional quark model,have been discovered over the past two decades.Investigating these states can lead to a deeper understanding of the nonperturbative dynamics of the strong interaction...Exotic hadrons,beyond the conventional quark model,have been discovered over the past two decades.Investigating these states can lead to a deeper understanding of the nonperturbative dynamics of the strong interaction.In this review,we focus on the production of exotic hadrons in pp,PP^(-),and nuclear collisions.Experimental observations of light and hypernuclei as prototypes of hadronic molecules in heavy-ion collisions are also briefly discussed.展开更多
The beyond-dripline oxygen isotopes^(27,28)O were recently observed at RIKEN,and were found to be unbound decaying into^(24)O by emitting neutrons.The unbound feature of the heaviest oxygen isotope,^(28)O,provides an ...The beyond-dripline oxygen isotopes^(27,28)O were recently observed at RIKEN,and were found to be unbound decaying into^(24)O by emitting neutrons.The unbound feature of the heaviest oxygen isotope,^(28)O,provides an excellent test for stateof-the-art nuclear models.The atomic nucleus is a self-organized quantum manybody system comprising specific numbers of protons Z and neutrons N.展开更多
The role of the delta isobar degrees of freedom in nucleon–nucleon scattering is revisited.We attempt to understand why the dimensionally regularized two-pion exchanges with the explicit delta isobar is much stronger...The role of the delta isobar degrees of freedom in nucleon–nucleon scattering is revisited.We attempt to understand why the dimensionally regularized two-pion exchanges with the explicit delta isobar is much stronger than the ones with spectral function regularization.When the cutoff value of spectral function regularization is varied,the isoscalar central component exhibits a rather large cut-off variation.This reveals a surprisingly large numerical factor of the deltaful two-pion exchange potentials.The power counting is adjusted accordingly and we discuss the results and how to improve upon this finding.展开更多
We derive the discontinuities of banana integrals using the dispersion relation iteratively,and find a series of identities between the parameterized discontinuities of banana integrals(p-DOBIs).Similar to elliptic in...We derive the discontinuities of banana integrals using the dispersion relation iteratively,and find a series of identities between the parameterized discontinuities of banana integrals(p-DOBIs).Similar to elliptic integrals,these identities enable the reduction of various p-DOBIs to be a linear combination of some fundamental ones.We present a practical application of p-DOBIs for deriving the Picard–Fuchs operator.Then we establish the expression of generalized dispersion relation,which enables us to obtain the dispersion relation representation of arbitrary banana integrals.Moreover,we propose a hypothesis for generalized dispersion relation and p-DOBIs,which provides a simple way to calculate the discontinuities and transform dispersion relation representation to p-DOBIs.展开更多
Within the extended vector meson dominance model,we investigate the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction and the electromagnetic form factors of the charmed baryon𝛬 Λ_(c)^(+)𝑐.The model par...Within the extended vector meson dominance model,we investigate the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction and the electromagnetic form factors of the charmed baryon𝛬 Λ_(c)^(+)𝑐.The model parameters are determined by fitting them to the cross sections of the process𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) and the magnetic form factor|G_(M)|of Λ_(c)^(+) .By considering four charmonium-like states,called𝜓(4500),𝜓(4660),𝜓(4790),and𝜓(4900),we can well describe the current data on the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction from the reaction threshold up to 4.96 GeV.In addition to the total cross sections and|𝐺M|,the ratio|G_(E)/G_(M)|and the effective form factor|Geff|for Λ_(c)^(+) 𝑐are also calculated,and found that these calculations are consistent with the experimental data.Within the fitted model parameters,we have also estimated the charge radius of the charmed Λ_(c)^(+) baryon.展开更多
Recently,a new excited baryon state,Ω(2012),was observed in the invariant mass spectra of𝐾K^(-)■^(0) and K_(S)^(0)■^(-)by the Belle collaboration.This state has a narrow width(∼6 MeV)compared to other bary...Recently,a new excited baryon state,Ω(2012),was observed in the invariant mass spectra of𝐾K^(-)■^(0) and K_(S)^(0)■^(-)by the Belle collaboration.This state has a narrow width(∼6 MeV)compared to other baryon states with a similar mass.Here,we provide a mini-review on the Ω(2012)state from the molecular perspective,where it appears to be a dynamically generated state with spin-parity 3/2^(−)from the coupled-channels interactions of the K■(1530)and ηΩ in s-wave and K■ in𝑑d-wave.Additionally,alternative explanations for the Ω(2012)resonance are also discussed.展开更多
The structure of light diquarks plays a crucial role in formation of exotic hadrons beyond the conventional quark model,especially with regard to the line shapes of bottomed hadron decays.We study the two-body hadroni...The structure of light diquarks plays a crucial role in formation of exotic hadrons beyond the conventional quark model,especially with regard to the line shapes of bottomed hadron decays.We study the two-body hadronic weak decays of bottomed baryons and bottomed mesons to probe the light diquark structure and to pin down the quark–quark correlations in the diquark picture.It is found that the light diquark does not favor a compact structure.For instance,the isoscalar diquark[ud]inΛ_(b)^(0)can be easily split and rearranged to form■via the color-suppressed transition.This provides a hint that the hidden charm pentaquark states produced inΛ_(b)^(0)decays could be the■chadronic molecular candidates.This quantitative study resolves the apparent conflicts between the production mechanism and the molecular nature of these P_(c)states observed in experiment.展开更多
Strong empirical and phenomenological indications exist for large sea-quark admixtures in the low-lying excited baryons.Investigating the low-lying excited baryon ∑^(*)(1/2^(-))is important for determining the nature...Strong empirical and phenomenological indications exist for large sea-quark admixtures in the low-lying excited baryons.Investigating the low-lying excited baryon ∑^(*)(1/2^(-))is important for determining the nature of the low-lying excited baryons.We review the experimental and theoretical progress on the studies of the ∑^(*)(1/2^(-)).展开更多
Magicity,or shell closure,plays an important role in our understanding of complex nuclear phenomena.In this work,we employ one of the state-of-the-art density functional theories,the deformed relativistic Hartree-Bogo...Magicity,or shell closure,plays an important role in our understanding of complex nuclear phenomena.In this work,we employ one of the state-of-the-art density functional theories,the deformed relativistic Hartree-Bogoliubov theory in continuum(DRHBc)with the density functional PC-PK1,to investigate the evolution of the N=20,28,50 shell closures in the 20≤Z≤30 region.We show how these three conventional shell closures evolve from the proton drip line to the neutron drip line by studying the charge radii,two-neutron separation energies,two-neutron gaps,quadrupole deformations,and single-particle levels.In particular,we find that in the 21≤Z≤27 region,the N=50 shell closure disappears or becomes quenched,mainly due to the deformation effects.Similarly,both experimental data and theoretical predictions indicate that the N=28 shell closure disappears in the Mn isotopic chain,mainly due to the deformation effects.The DRHBc theory predicts the existence of the N=20 shell closure in the Ca,Sc,and Ti isotopic chains,but the existing data for the Ti isotopes suggest the contrary,and therefore further research is needed.展开更多
We investigate the valence quark distributions of pions at a low initial scale(Q_(0)^(2))using Tsallis entropy,a non-extensive measure that effectively captures long-range correlations among internal constituents.Util...We investigate the valence quark distributions of pions at a low initial scale(Q_(0)^(2))using Tsallis entropy,a non-extensive measure that effectively captures long-range correlations among internal constituents.Utilizing the maximum entropy approach,we adopt two distinct functional forms and fit experimental data using the elegant GLR-MQ-ZRS evolution equation to derive the model parameters.Our findings indicate that the resulting valence quark distributions provide an optimal fit to the experimental data,with q values deviating from unity.This deviation indicates that correlations among valence quarks play a significant role in shaping understanding of the internal structures of pions.Additionally,our computations of the first three moments of the pion quark distributions at Q^(2)=4 GeV^(2) display consistency with other theoretical models,thereby reinforcing the importance of incorporating valence quark correlations within this analytical framework.展开更多
We propose a major upgrade to the existing PandaX-4T experiment at the China Jinping Underground Laboratory.The new experiment,PandaX-xT,will be a multi-ten-tonne liquid xenon,ultra-low background,and general-purpose ...We propose a major upgrade to the existing PandaX-4T experiment at the China Jinping Underground Laboratory.The new experiment,PandaX-xT,will be a multi-ten-tonne liquid xenon,ultra-low background,and general-purpose observatory.The full-scaled PandaX-xT contains a 43-t liquid xenon active target.Such an experiment will significantly advance our fundamental understanding of particle physics and astrophysics.The sensitivity of dark matter direct detection will be improved by nearly two orders of magnitude compared to the current best limits,approaching the so-called“neutrino floor”for a dark matter mass above 10 GeV/c^(2),providing a key test to the Weakly Interacting Massive Particle paradigm.By searching for the neutrinoless double beta decay of^(136)Xe isotope in the detector,the effective Majorana neutrino mass can be measured to a 10-41 meV/c^(2) sensitivity,providing a key test to the Dirac/Majorana nature of neutrinos.Astrophysical neutrinos and other ultra-rare interactions can also be measured and searched for with an unprecedented background level,opening up new windows of discovery.Depending on the findings,PandaX-xT will seek the next stage upgrade utilizing isotopic separation of natural xenon.展开更多
Bremsstrahlung photons emitted during nucleon-nucleus reactions in compact stars are investigated.The influence of stellar medium density on emission intensity is studied from a quantum perspective for the first time....Bremsstrahlung photons emitted during nucleon-nucleus reactions in compact stars are investigated.The influence of stellar medium density on emission intensity is studied from a quantum perspective for the first time.A bremsstrahlung model is generalized,where a new term describing the influence of the stellar medium is added to interactions between nucleons and nuclei(in the framework of a nuclear model of deformed oscillatoric shells).Polytropic EOS,Chandrasekar EOS,and Harrison-Wheeler EOS are employed for calculation.Haensel and Potekhin's unified EOS of neutron-star matter based on FPS and SLy EOSs are used for tests.Bremsstrahlung calculations are tested on existing measurements of bremsstrahlung in the scattering of protons off ^(197)Au nuclei at a proton beam energy of E_(p)=190 MeV.Many properties of bremsstrahlung emitted from nuclear processes in the stellar medium of compact stars are studied for the first time.In particular,the spectra of photons in the scattering of protons and neutrons off ^(4)He,^(8)Be,^(12)C,^(16O),^(24)Mg,40Ca,^(56)Fe are estimated based on stellar medium density.The medium of white dwarfs has a small influence on the bremsstrahlung emission from nuclear processes,while bremsstrahlung emission is intensive in neutron stars and it is changed in dependence on stellar medium and structure.展开更多
The quest for understanding the internal structure of hadrons is key to probing how color confinement,which remains a fundamental challenge in the Standard Model,manifests itself.The lowest-lying hadrons fit well into...The quest for understanding the internal structure of hadrons is key to probing how color confinement,which remains a fundamental challenge in the Standard Model,manifests itself.The lowest-lying hadrons fit well into the classification of the conventional quark model,such as quark-antiquark mesons and three-quark baryons.However,for excited states,the energy excitation inside a hadron can be distributed in various ways:it can appear as orbital or radial excitation within a conventional quark model configuration,or it leads to the creation of a quark-antiquark pair.展开更多
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(Grant Nos.2020B0301030008 and 2023A1515010416)the National Natural Science Foundation of China(Grant Nos.12375073,12275091,12147128,and 12035007).
文摘We study the production of the X(6900)in the ultra-peripheral heavy ion collisions at the LHC energy region.The potential quantum numbers of X(6900)could be 0^(±+)and 2^(±+).We find that the transverse momentum and the polar angle distributions of X(6900)can be used to distinguish these four potential quantum numbers.These characteristic distributions originate from linearly polarized photons emitted by relativistic nuclei and can be measured by further LHC experiments.
基金supported by the National Key R&D Program of China(Nos.2024YFA1610900 and 2023YFA1606401)the National Natural Science Foundation of China(Nos.12335007 and 12035001)the United Kingdom Science and Technology Facilities Council(No.ST/V001108/1)。
文摘High multipole electromagnetic transitions are rare in nature.The highest-multipole transition observed in atomic nuclei is the electric hexacontatetrapole E6 transition from the T_(1/2)=2.54(2)-min J^(π)=1_(9/2)-isomer to the 7/2^(-)ground state in^(53)Fe with an angular momentum change of six units.In the present work,we performed ab initio calculations for this unique case by employing chiral effective field theory(EFT)forces.The in-medium similarity renormalization group is used to derive the valence-space effective Hamiltonian and multipolar transition operators.Bare nucleon charges were used in all the multipolar transition rate calculations,providing good agreement with the experimental data.The valence space takes the full fp shell.In^(53)Fe,the low-lying states were dominated by the 0f_(7/2)component.Two different versions of the chiral EFT two-plus three-nucleon interaction were used to test the dependence on the interaction used.We also tested the convergence of the transition rate calculations against the harmonic oscillator parameter hΩand basis truncations e_(max)and E_(3max)for twoand three-nucleon forces,respectively.
基金supported in part by the National Natural Science Foundation of China (Grant Nos.12375073 and 12235018)。
文摘We present a concise review of the vector charmonium state ψ(4230), which was originally labelled as Y(4260)in the literature. As one of the earliest candidates for a quantum chromodynamics exotic states, its interpretation has initiated various ideas about possible manifestations of non-perturbative mechanisms in the charmonium mass regime. In this short article we briefly review the experimental status of ψ(4230) and discuss possible theoretical interpretations. We will focus on four broadly investigated scenarios, i.e., tetraquark, hybrid, hadro-quarkonium,and hadronic molecule, and highlight the key issues based on these approaches. Crucial experimental observables,e.g., mass position, lineshapes, di-lepton decay width Γ_(ee), production rates in B meson decays, dominant hadronic decay patterns, and the potential 1^(-+)and 0^(--)exotic partners, are assessed, which can provide crucial structure information for understanding this mysterious state.
基金supported in part by the National Natural Science Foundation of China(NSFC)under Grants Nos.12125507,12361141819,and 12047503the National Key R&D Program of China under Grant No.2023YFA1606703+1 种基金the Chinese Academy of Sciences(CAS)under Grants No.YSBR-101the CAS President’s International Fellowship Initiative(PIFI)under Grant No.2025PD0087 for the partial support。
文摘We argue that the hypothesis that positive-parity charm meson resonances exhibit a compact tetraquark structure has some clear tension with recent lattice results for the S-waveπD system for an SU(3)flavor symmetric setting.In particular,we show that such a diquark–anti-diquark tetraquark scenario would call for the presence of a state in the flavor[15]representation,not seen in the lattice analysis.Moreover,we show that analogous lattice data in the axial-vector channel are even more sensitive to the internal structure of these very interesting states.
基金supported by the the National Key R&D Program of China(Grant Nos.2022YFA1604900 and 2023YFA1606703)the National Natural Science Foundation of China(Grant Nos.12025501,12435007,12405133,and 12347180)+1 种基金China Postdoctoral Science Foundation(Grant No.2023M740189)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20233381).
文摘Hypernuclei,nuclei containing one or more hyperons,serve as unique laboratories for probing the non-perturbative quantum chromodynamics(QCD).Recent progress in hypernuclear physics,driven by advanced experimental techniques and theoretical innovations,is briefly reviewed with a focus on key findings and unresolved challenges,such as the precise determination of the hypertriton binding energy,investigations of charge symmetry breaking in mirror hypernuclei,and the search for exotic systems,including the neutral nnΛstate.Experimental breakthroughs,including invariant-mass analyses and femtoscopy studies in heavy-ion collisions,as well as high-resolutionγ-spectroscopy,have enabled precise studies of light hypernuclei and offered critical insights into the hyperon–nucleon interaction.Theoretical progress,including ab initio calculations based on chiral effective field theory and lattice QCD,has further enhanced our understanding of hyperon–nucleon and hyperon–hyperon interactions.
基金supported by the National Key R&D Program of China(Nos.2023YFE0101500,2023YFA1606403)the National Natural Science Foundation of China(Nos.12475118,12335007)the State Key Laboratory of Nuclear Physics and Technology,Peking University(No.NPT2023ZX01)。
文摘We studied the energy partition between two well-separated fission fragments associated with the partition of nucleons owing to quantum entanglement.This is different from most fission models that invoke an explicit statistical partition of excitation energies.The dynamical fission evolution is described within the time-dependent Hartree-Fock+BCS framework.Excitation energies of isotopic fission fragments were obtained using the particle number projection method after the dynamical splitting of^(238)U.The resulting excitation energies of the light and heavy fragments are consistent with the appearance of sawtooth structures.We found that the pairing correlation strengths have a significant influence on the partition of the excitation energies.Furthermore,the excitation energies of isotopic fragments increase with increasing neutron number,implying the suppression of the production of neutron-rich beams in rare-isotope beam facilities.
基金supported by the National Key R&D Program of China(Nos.2024YFA1610900,2023YFA1606401,and 2023YFA1606403)the National Natural Science Foundation of China(Nos.12335007,12035001 and 12205340)。
文摘The full configuration interaction quantum Monte Carlo(FCIQMC)method,originally developed in quantum chemistry,has also been successful for both molecular and condensed matter systems.Another natural extension of this methodology is its application to nuclear structure calculations.We developed an FCIQMC approach to study nuclear systems.To validate this method,we applied FCIQMC to a small model space,where the standard shell model remains computationally feasible.Specifically,we performed calculations for?ωisotopes using pf-shell GXPF1A interaction and compared the results with those obtained from the standard shell model calculations.To further demonstrate the capabilities of the FCIQMC,we investigated its performance in systems exhibiting strong correlations,where conventional nuclear structure models are less effective.Using an artificially constructed strongly correlated system with a modified GXPF1A interaction,our calculations revealed that FCIQMC delivered superior results compared to many existing methods.Finally,we applied FCIQMC to Fe isotopes in the sdpf-shell model space,showing its potential to perform accurate calculations in large model spaces that are inaccessible to the shell model because of the limitations of current computational resources.
基金supported in part by the National Key Research and Development Program of China(Nos.2022YFA1604900,2023YFA1606703,2024YFA1610503)the National Natural Science Foundation of China(Nos.12025501,12147101,12375073,12125507,12361141819,12047503,12175239,12221005)the Chinese Academy of Sciences(Nos.XDB34000000 and YSBR-101)。
文摘Exotic hadrons,beyond the conventional quark model,have been discovered over the past two decades.Investigating these states can lead to a deeper understanding of the nonperturbative dynamics of the strong interaction.In this review,we focus on the production of exotic hadrons in pp,PP^(-),and nuclear collisions.Experimental observations of light and hypernuclei as prototypes of hadronic molecules in heavy-ion collisions are also briefly discussed.
基金This work was supported by the National Natural Science Foundation of China(Nos.12335007,11835001,11921006,12035001 and 12205340)the State Key Laboratory of Nuclear Physics and Technology,Peking University(No.NPT2020KFY13)Gansu Natural Science Foundation(No.22JR5RA123).
文摘The beyond-dripline oxygen isotopes^(27,28)O were recently observed at RIKEN,and were found to be unbound decaying into^(24)O by emitting neutrons.The unbound feature of the heaviest oxygen isotope,^(28)O,provides an excellent test for stateof-the-art nuclear models.The atomic nucleus is a self-organized quantum manybody system comprising specific numbers of protons Z and neutrons N.
基金supported by the National Natural Science Foundation of China(NSFC)under Grant Nos.12275185,12335002(BL),and 12347154(RP)。
文摘The role of the delta isobar degrees of freedom in nucleon–nucleon scattering is revisited.We attempt to understand why the dimensionally regularized two-pion exchanges with the explicit delta isobar is much stronger than the ones with spectral function regularization.When the cutoff value of spectral function regularization is varied,the isoscalar central component exhibits a rather large cut-off variation.This reveals a surprisingly large numerical factor of the deltaful two-pion exchange potentials.The power counting is adjusted accordingly and we discuss the results and how to improve upon this finding.
基金supported by the National Natural Science Foundation of China(Grant No.12175318)the Natural Science Foundation of Guangdong Province of China(Grant No.2022A1515011922).
文摘We derive the discontinuities of banana integrals using the dispersion relation iteratively,and find a series of identities between the parameterized discontinuities of banana integrals(p-DOBIs).Similar to elliptic integrals,these identities enable the reduction of various p-DOBIs to be a linear combination of some fundamental ones.We present a practical application of p-DOBIs for deriving the Picard–Fuchs operator.Then we establish the expression of generalized dispersion relation,which enables us to obtain the dispersion relation representation of arbitrary banana integrals.Moreover,we propose a hypothesis for generalized dispersion relation and p-DOBIs,which provides a simple way to calculate the discontinuities and transform dispersion relation representation to p-DOBIs.
基金supported by the National Key R&D Program of China(Grant No.2023YFA1606703)the National Natural Science Foundation of China(Grant No.12075288)the Youth Innovation Promotion Association CAS.
文摘Within the extended vector meson dominance model,we investigate the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction and the electromagnetic form factors of the charmed baryon𝛬 Λ_(c)^(+)𝑐.The model parameters are determined by fitting them to the cross sections of the process𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) and the magnetic form factor|G_(M)|of Λ_(c)^(+) .By considering four charmonium-like states,called𝜓(4500),𝜓(4660),𝜓(4790),and𝜓(4900),we can well describe the current data on the𝑒e^(+)e^(-)→Λ_(c)+Λ_(c)^(- ) reaction from the reaction threshold up to 4.96 GeV.In addition to the total cross sections and|𝐺M|,the ratio|G_(E)/G_(M)|and the effective form factor|Geff|for Λ_(c)^(+) 𝑐are also calculated,and found that these calculations are consistent with the experimental data.Within the fitted model parameters,we have also estimated the charge radius of the charmed Λ_(c)^(+) baryon.
基金supported by the National Key R&D Program of China(Grant No.2023YFA1606703)the National Natural Science Foundation of China(Grant Nos.12075288 and 12361141819)the Youth Innovation Promotion Association of CAS.
文摘Recently,a new excited baryon state,Ω(2012),was observed in the invariant mass spectra of𝐾K^(-)■^(0) and K_(S)^(0)■^(-)by the Belle collaboration.This state has a narrow width(∼6 MeV)compared to other baryon states with a similar mass.Here,we provide a mini-review on the Ω(2012)state from the molecular perspective,where it appears to be a dynamically generated state with spin-parity 3/2^(−)from the coupled-channels interactions of the K■(1530)and ηΩ in s-wave and K■ in𝑑d-wave.Additionally,alternative explanations for the Ω(2012)resonance are also discussed.
基金partly supported by the National Natural Science Foundation of China(Grant Nos.12375073,12035007,12205106,and 12105028)Guangdong Provincial Fund(Grant No.2019QN01X172)+2 种基金Guangdong Major Project of Basic and Applied Basic Research(Grant No.2020B0301030008)the NSFC and the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)through the funds provided to the Sino-German Collaborative Research Center TRR110“Symmetries and the Emergence of Structure in QCD”(NSFC Grant No.12070131001,DFG Project-ID 196253076-TRR 110)supported by the Natural Science Foundation of Jiangsu Province(Grant No.BK20200980)
文摘The structure of light diquarks plays a crucial role in formation of exotic hadrons beyond the conventional quark model,especially with regard to the line shapes of bottomed hadron decays.We study the two-body hadronic weak decays of bottomed baryons and bottomed mesons to probe the light diquark structure and to pin down the quark–quark correlations in the diquark picture.It is found that the light diquark does not favor a compact structure.For instance,the isoscalar diquark[ud]inΛ_(b)^(0)can be easily split and rearranged to form■via the color-suppressed transition.This provides a hint that the hidden charm pentaquark states produced inΛ_(b)^(0)decays could be the■chadronic molecular candidates.This quantitative study resolves the apparent conflicts between the production mechanism and the molecular nature of these P_(c)states observed in experiment.
基金partly supported by the National Key R&D Program of China(Grant No.2023YFA1606700)partly supported by the National Key R&D Program of China(Grant No.2024YFE0105200)+6 种基金supported by the Natural Science Foundation of Henan(Grant Nos.232300421140 and 222300420554)the National Natural Science Foundation of China(Grant Nos.12475086,12192263,12205075,12175239,12221005,12075288,and 12361141819)the Open Project of Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology(Grant No.NLK2021-08)the Central Government Guidance Funds for Local Scientific and Technological Development,China(Grant No.ZY22096024)the National Key Research and Development Program of China(Grant No.2020YFA0406400)the Chinese Academy of Sciences(Grant No.YSBR-101)the Youth Innovation Promotion Association of CAS。
文摘Strong empirical and phenomenological indications exist for large sea-quark admixtures in the low-lying excited baryons.Investigating the low-lying excited baryon ∑^(*)(1/2^(-))is important for determining the nature of the low-lying excited baryons.We review the experimental and theoretical progress on the studies of the ∑^(*)(1/2^(-)).
基金Supported in part by the National Natural Science Foundation of China(NSFC)(11975041,11961141004)Xiang-Xiang Sun is supported in part by NSFC(12205308)the Deutsche Forschungsgemeinschaft(DFG)and NSFC through the funds provided to the Sino-German Collaborative Research Center TRR110"Symmetries and the Emergence of Structure in QCD"(NSFC Grant No.12070131001,DFG Project-ID 196253076)。
文摘Magicity,or shell closure,plays an important role in our understanding of complex nuclear phenomena.In this work,we employ one of the state-of-the-art density functional theories,the deformed relativistic Hartree-Bogoliubov theory in continuum(DRHBc)with the density functional PC-PK1,to investigate the evolution of the N=20,28,50 shell closures in the 20≤Z≤30 region.We show how these three conventional shell closures evolve from the proton drip line to the neutron drip line by studying the charge radii,two-neutron separation energies,two-neutron gaps,quadrupole deformations,and single-particle levels.In particular,we find that in the 21≤Z≤27 region,the N=50 shell closure disappears or becomes quenched,mainly due to the deformation effects.Similarly,both experimental data and theoretical predictions indicate that the N=28 shell closure disappears in the Mn isotopic chain,mainly due to the deformation effects.The DRHBc theory predicts the existence of the N=20 shell closure in the Ca,Sc,and Ti isotopic chains,but the existing data for the Ti isotopes suggest the contrary,and therefore further research is needed.
基金Supported by National Key R&D Program of China(2024YFE0109800,2024YFE0109802)National Natural Science Foundation of China(12375073)Guizhou Provincial Basic Research Program(Natural Science)(QKHJC-ZK[2023]YB027)。
文摘We investigate the valence quark distributions of pions at a low initial scale(Q_(0)^(2))using Tsallis entropy,a non-extensive measure that effectively captures long-range correlations among internal constituents.Utilizing the maximum entropy approach,we adopt two distinct functional forms and fit experimental data using the elegant GLR-MQ-ZRS evolution equation to derive the model parameters.Our findings indicate that the resulting valence quark distributions provide an optimal fit to the experimental data,with q values deviating from unity.This deviation indicates that correlations among valence quarks play a significant role in shaping understanding of the internal structures of pions.Additionally,our computations of the first three moments of the pion quark distributions at Q^(2)=4 GeV^(2) display consistency with other theoretical models,thereby reinforcing the importance of incorporating valence quark correlations within this analytical framework.
基金supported by the Office of Science and Technology,Shanghai Municipal Government(Grant Nos.23JC1410200,and 22JCJC1410200)the Ministry of Science and Technology of China(Grant No.2023YFA1606200)+6 种基金the National Natural Science Foundation of China(Grant Nos.1209060,12005131,11905128,11925502,12222505,and 12175139)support from Double First Class Plan of the Shanghai Jiao Tong Universitythe Tsung-Dao Lee Institute Experimental Platform Development Fundthe sponsorship from the Hongwen Foundation in Hong KongTencentNew Cornerstone Science Foundation in ChinaYangyang Development Fund。
文摘We propose a major upgrade to the existing PandaX-4T experiment at the China Jinping Underground Laboratory.The new experiment,PandaX-xT,will be a multi-ten-tonne liquid xenon,ultra-low background,and general-purpose observatory.The full-scaled PandaX-xT contains a 43-t liquid xenon active target.Such an experiment will significantly advance our fundamental understanding of particle physics and astrophysics.The sensitivity of dark matter direct detection will be improved by nearly two orders of magnitude compared to the current best limits,approaching the so-called“neutrino floor”for a dark matter mass above 10 GeV/c^(2),providing a key test to the Weakly Interacting Massive Particle paradigm.By searching for the neutrinoless double beta decay of^(136)Xe isotope in the detector,the effective Majorana neutrino mass can be measured to a 10-41 meV/c^(2) sensitivity,providing a key test to the Dirac/Majorana nature of neutrinos.Astrophysical neutrinos and other ultra-rare interactions can also be measured and searched for with an unprecedented background level,opening up new windows of discovery.Depending on the findings,PandaX-xT will seek the next stage upgrade utilizing isotopic separation of natural xenon.
文摘Bremsstrahlung photons emitted during nucleon-nucleus reactions in compact stars are investigated.The influence of stellar medium density on emission intensity is studied from a quantum perspective for the first time.A bremsstrahlung model is generalized,where a new term describing the influence of the stellar medium is added to interactions between nucleons and nuclei(in the framework of a nuclear model of deformed oscillatoric shells).Polytropic EOS,Chandrasekar EOS,and Harrison-Wheeler EOS are employed for calculation.Haensel and Potekhin's unified EOS of neutron-star matter based on FPS and SLy EOSs are used for tests.Bremsstrahlung calculations are tested on existing measurements of bremsstrahlung in the scattering of protons off ^(197)Au nuclei at a proton beam energy of E_(p)=190 MeV.Many properties of bremsstrahlung emitted from nuclear processes in the stellar medium of compact stars are studied for the first time.In particular,the spectra of photons in the scattering of protons and neutrons off ^(4)He,^(8)Be,^(12)C,^(16O),^(24)Mg,40Ca,^(56)Fe are estimated based on stellar medium density.The medium of white dwarfs has a small influence on the bremsstrahlung emission from nuclear processes,while bremsstrahlung emission is intensive in neutron stars and it is changed in dependence on stellar medium and structure.
基金supported in part by the National Natural Science Foundation of China(12125507,12361141819,and 12447101)the National Key R&D Program of China(2023YFA1606703)the Chinese Academy of Sciences(YSBR101).
文摘The quest for understanding the internal structure of hadrons is key to probing how color confinement,which remains a fundamental challenge in the Standard Model,manifests itself.The lowest-lying hadrons fit well into the classification of the conventional quark model,such as quark-antiquark mesons and three-quark baryons.However,for excited states,the energy excitation inside a hadron can be distributed in various ways:it can appear as orbital or radial excitation within a conventional quark model configuration,or it leads to the creation of a quark-antiquark pair.
