An improved method is proposed for the extraction of the symmetry energy coefficient relative to the temperature,a_(sym)/T,in the heavy-ion reactions near the Fermi energy region,based on the modified Fisher Model.Thi...An improved method is proposed for the extraction of the symmetry energy coefficient relative to the temperature,a_(sym)/T,in the heavy-ion reactions near the Fermi energy region,based on the modified Fisher Model.This method is applied to the primary fragments of antisymmetrized molecular dynamics(AMD)simulations for ^(46)Fe+^(46)Fe,^(40)Ca+^(40)Ca and ^(48)Ca+^(48)Ca at 35 MeV/nucleon,in order to make direct comparison to the results from the K(N,Z)method of Ono et al.In our improved method,the extracted values of a_(sym)/T increase as the size of isotopes increases whereas,in the K(N,Z)method,the results show rather constant behavior.This increase in our result is attributed to the surface contribution of the symmetry energy in finite nuclei.In order to evaluate the surface contribution,the relation a_(sym)/T=[a_(sym)^((V))(1-k_(S/V) A^(-1/3))]/T is applied and k_(S/V)=1.20~1.25 was extracted.This value is smaller than those extracted from the mass table,reflecting the weakened surface contribution at higher temperature regime.Δμ/T,the difference of the neutron-proton chemical potentials relative to the temperature,is also extracted in this method at the same time.The average values of the extractedΔμ/T,Δμ/T show a linear dependence on the proton-neutron a_(sym)metry parameter of the system,δ_(sys),andΔμ/T=(15.1±0.2)δ_(sys)-(0.5±0.1)is obtained.展开更多
Experimental elastic scattering angular distributions of 11B,2C,and 16O+heavy-ions are used to studythe Woods-Saxon potential parameters.Best fitted values of the diffuseness parameters are found for each system,and a...Experimental elastic scattering angular distributions of 11B,2C,and 16O+heavy-ions are used to studythe Woods-Saxon potential parameters.Best fitted values of the diffuseness parameters are found for each system,and a linear relationship is expressed between the diffuseness parameters and A1/31+A1/32.The correlation of the po-tential depth and radius parameters with A1/31+A1/32is also revealed within the limitations of the diffuseness parameter formula.Because the incident energies of most of the analyzed reactions are below or around the Coulombbarrier,the energy dispersion relation between the real and imaginary potentials is considered in order to investigatethe ratio between the imaginary and real potential well depths,resulting in an expression of W/V.Within the limitation of the volume integrals calculated with the Sao Paulo potential,parameterized formulas for the depth and radius parameters are obtained.The systematic Woods-Saxon potential parameters derived in the present work can reproduce not only the experimental data of elastic scattering angular distributions induced by 11B,12C,and 16O butalso some elastic scattering induced by other heavy-ions.展开更多
We developed a dedicated data analysis framework for silicon strip detector telescopes(SSDTs)of the Compact Spectrometer for Heavy-IoN Experiments(CSHINE)that addresses the challenges of processing complex signals.The...We developed a dedicated data analysis framework for silicon strip detector telescopes(SSDTs)of the Compact Spectrometer for Heavy-IoN Experiments(CSHINE)that addresses the challenges of processing complex signals.The framework integrates advanced algorithms for precise calibration,accurate particle identification,and efficient event reconstruction,aiming to account for critical experimental factors such as charge-sharing effects,multi-hit event resolution,and detector response nonuniformity.Its robust performance was demonstrated through the successful analysis of light-charged particles in the 25 MeV/u^(86)Kr+^(124)Sn experiment conducted at the first Radioactive Ion Beam Line in Lanzhou,allowing for precise extraction of physical observables,including energy,momentum,and particle type.Furthermore,utilizing the reconstructed physical information,such as the number of effective physical events and energy spectra to optimize the track recognition algorithm,the final track recognition efficiencies of approximately 90%were achieved.This framework establishes a valuable reference methodology for SSDT-based detector systems in heavy-ion reaction experiments,thereby significantly enhancing the accuracy and efficiency of data analysis in nuclear physics research.展开更多
A heavy-ion time-of-flight spectrometer called HiToF,with magnet focusing accomplished by a quadrupole triplet lens,was constructed at the Beijing Tandem Accelerator National Laboratory,mainly for studies of multi-nuc...A heavy-ion time-of-flight spectrometer called HiToF,with magnet focusing accomplished by a quadrupole triplet lens,was constructed at the Beijing Tandem Accelerator National Laboratory,mainly for studies of multi-nucleon transfer reactions at energies near the Coulomb barrier.The spectrometer was equipped with a rotating chamber with a diameter of 40 cm and could be rotated over a large angular range from−40◦to 160◦.The length from the target to the focal plane is 2.7 m,enabling high-precision time-of-flight measurements using two microchannel plate detectors with a 1.9 m apart and a typical time resolution of 120 ps.A multisampling position-sensitive ionization chamber forΔE−E measurement is placed on the focal plane,which offers aΔZ∕Z resolution of 1/50.The setup provided a maximum solid angleΔΩ=20 msr.An experiment on^(32)S+^(90,94)Zr at a beam energy of 135 MeV was performed to test the performance.The projectile-like ions were identified with a mass resolution ofσ=0.2 amu.The results showed that the HiToF spectrometer is a powerful setup for studying heavy-ion reaction mechanisms at low energies.展开更多
While the abundances of the final state hadrons in relativistic heavy-ion collisions are rather well described by the thermal particle production,the shape of the transverse momentum,pT,distribution below p_(T)≈500 M...While the abundances of the final state hadrons in relativistic heavy-ion collisions are rather well described by the thermal particle production,the shape of the transverse momentum,pT,distribution below p_(T)≈500 MeV/c,is still poorly understood.We propose a procedure to quantify the model-to-data differences using Bayesian inference techniques,which allows for consistent treatment of the experimental uncertainties and tests the completeness of the available hydrodynamic frameworks.Using relativistic fluid framework FluiduM with PCE coupled to TrENTo initial state and FasTrEso decays,we analyze p_(T)distribution of identified charged hadrons measured in heavy-ion collisions at top RHIC and the LHC energies and identify an excess of pions produced below p_(T)≈500 MeV/c.Our results provide new input for the interpretation of the pion excess as either missing components in the thermal particle yield description or as an evidence for a different particle production mechanism.展开更多
The derivation of the harmonic approximation of the Hamiltonian of a model of coupled three-dimensional harmonic oscillator is presented. It is shown how the splitting of the total Hamiltonian into the intrinsic and c...The derivation of the harmonic approximation of the Hamiltonian of a model of coupled three-dimensional harmonic oscillator is presented. It is shown how the splitting of the total Hamiltonian into the intrinsic and collective Hamiltonians leads to the description of the mechanism for energy dissipation in physical systems.展开更多
The relativistic heavy-ion collisions create both hot quark–gluon matter and strong magnetic fields, and provide an arena to study the interplay between quantum chromodynamics and quantum electrodynamics. In recent y...The relativistic heavy-ion collisions create both hot quark–gluon matter and strong magnetic fields, and provide an arena to study the interplay between quantum chromodynamics and quantum electrodynamics. In recent years, it has been shown that such an interplay can generate a number of interesting quantum phenomena in hadronic and quark–gluon matter. In this short review, we first discuss some properties of the magnetic fields in heavy-ion collisions and then give an overview of the magnetic fieldinduced novel quantum effects. In particular, we focus on the magnetic effect on the heavy flavor mesons, the heavyquark transports, and the phenomena closely related to chiral anomaly.展开更多
Recent progress of the quantum molecular dynamics model for describing the dynamics of heavy-ion collisions is viewed, in particular the nuclear fragmentation, isospin physics, particle production and in-medium effect...Recent progress of the quantum molecular dynamics model for describing the dynamics of heavy-ion collisions is viewed, in particular the nuclear fragmentation, isospin physics, particle production and in-medium effect, hadron-induced nuclear reactions, hypernucleus, etc.The neck fragmentation in Fermi-energy heavy-ion collisions is investigated for extracting the symmetry energy at subsaturation densities. The isospin effects, in-medium properties, and the behavior of high-density symmetry energy in medium-and high-energy heavy-ion collisions are thoroughly discussed. The hypernuclide dynamics formed in heavy-ion collisions and in hadron-induced reactions is analyzed and addressed in the future experiments at the high-intensity heavy-ion accelerator facility(HIAF).展开更多
We present a concise review of the recent development of relativistic hydrodynamics and its applications to heavy-ion collisions.Theoretical progress on the extended formulation of hydrodynamics toward out-ofequilibri...We present a concise review of the recent development of relativistic hydrodynamics and its applications to heavy-ion collisions.Theoretical progress on the extended formulation of hydrodynamics toward out-ofequilibrium systems is addressed,with emphasis on the socalled attractor solution.Moreover,recent phenomenological improvements in the hydrodynamic modeling of heavy-ion collisions with respect to the ongoing beam energy scan program,the quantitative characterization of transport coefficients in three-dimensionally expanding quark–gluon plasma,the fluid description of small colliding systems,and certain other interdisciplinary connections are discussed.展开更多
Relativistic heavy-ion collisions create hot quark–gluon plasma as well as very strong electromagnetic(EM)and fluid vortical fields.The strong EM field and vorticity can induce intriguing macroscopic quantum phenomen...Relativistic heavy-ion collisions create hot quark–gluon plasma as well as very strong electromagnetic(EM)and fluid vortical fields.The strong EM field and vorticity can induce intriguing macroscopic quantum phenomena such as chiral magnetic,chiral separation,chiral electric separation,and chiral vortical effects as well as the spin polarization of hadrons.These phenomena provide us with experimentally feasible means to study the nontrivial topological sector of quantum chromodynamics,the possible parity violation of strong interaction at high temperature,and the subatomic spintronics of quark–gluon plasma.These studies,both in theory and in experiments,are strongly connected with other subfields of physics such as condensed matter physics,astrophysics,and cold atomic physics,and thus form an emerging interdisciplinary research area.We give an introduction to the aforementioned phenomena induced by the EM field and vorticity and an overview of the current status of experimental research in heavy-ion collisions.We also briefly discuss spin hydrodynamics as well as chiral and spin kinetic theories.展开更多
The propagation of single-event effects(SEEs)on a Xilinx Zynq-7000 system on chip(SoC)was inves-tigated using heavy-ion microbeam radiation.The irradia-tion results reveal several functional blocks’sensitivity locati...The propagation of single-event effects(SEEs)on a Xilinx Zynq-7000 system on chip(SoC)was inves-tigated using heavy-ion microbeam radiation.The irradia-tion results reveal several functional blocks’sensitivity locations and cross sections,for instance,the arithmetic logic unit,register,D-cache,and peripheral,while irradi-ating the on-chip memory(OCM)region.Moreover,event tree analysis was executed based on the obtained microbeam irradiation results.This study quantitatively assesses the probabilities of SEE propagation from the OCM to other blocks in the SoC.展开更多
We give a brief overview of recent theoretical and experimental results on the chiral magnetic effect and spin polarization effect in heavy-ion collisions.We present updated experimental results for the chiral magneti...We give a brief overview of recent theoretical and experimental results on the chiral magnetic effect and spin polarization effect in heavy-ion collisions.We present updated experimental results for the chiral magnetic effect and related phenomena.The time evolution of the magnetic fields in different models is discussed.The newly developed quantum kinetic theory for massive fermions is reviewed.We present theoretical and experimental results for the polarization of K hyperons and the q00 value of vector mesons.展开更多
Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic fields.In these collisions,highly charged fast-moving ions carry strong electromagnetic fields that...Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic fields.In these collisions,highly charged fast-moving ions carry strong electromagnetic fields that can be effectively treated as photon fluxes.The exchange of photons can induce photonuclear and two-photon interactions and excite ions.This excitation of the ions results in Coulomb dissociation with the emission of photons,neutrons,and other particles.Additionally,the electromagnetic fields generated by the ions can be sufficiently strong to enforce mutual interactions between the two colliding ions.Consequently,the two colliding ions experience an electromagnetic force that pushes them in opposite directions,causing a back-to-back correlation in the emitted neutrons.Using a Monte Carlo simulation,we qualitatively demonstrate that the above electromagnetic effect is large enough to be observed in UPCs,which would provide a clear means to study strong electromagnetic fields and their effects.展开更多
The swelling behavior of 20% cold-worked 15-15Ti steels with （0.23-0.40） wt% titanium and （0.42-0.81） wt% silicon content after heavy-ion beam irradiation has been investigated by transmission electron microscopy....The swelling behavior of 20% cold-worked 15-15Ti steels with （0.23-0.40） wt% titanium and （0.42-0.81） wt% silicon content after heavy-ion beam irradiation has been investigated by transmission electron microscopy. The results show that 15-15Ti steel with higher titanium content displays lower swelling. As silicon content increases, the cavity size and the swelling of the 15-15Ti steels decrease obviously. Titanium and silicon may play important roles in suppressing the cavity nucleation and growth in 15-15Ti steel.展开更多
In this study, the rapidity distribution, collective flows, and nuclear stopping power in ^(197)Au+^(197)Au collisions at intermediate energies were investigated using the ultrarelativistic quantum molecular dynamics(...In this study, the rapidity distribution, collective flows, and nuclear stopping power in ^(197)Au+^(197)Au collisions at intermediate energies were investigated using the ultrarelativistic quantum molecular dynamics(UrQMD) model with GEMINI++ code. The UrQMD model was adopted to simulate the dynamic evolution of heavy-ion collisions, whereas the GEMINI++ code was used to simulate the decay of primary fragments produced by UrQMD. The calculated results were compared with the INDRA and FOPI experimental data. It was found that the rapidity distribution, collective flows, and nuclear stopping power were affected to a certain extent by the decay of primary fragments, especially at lower beam energies. Furthermore, the experimental data of the collective flows and nuclear stopping power at the investigated beam energies were better reproduced when the sequential decay effect was included.展开更多
High-energy nuclear collisions encompass three key stages:the structure of the colliding nuclei,informed by low-energy nuclear physics,the initial condition,leading to the formation of quark-gluon plasma(QGP),and the ...High-energy nuclear collisions encompass three key stages:the structure of the colliding nuclei,informed by low-energy nuclear physics,the initial condition,leading to the formation of quark-gluon plasma(QGP),and the hydrodynamic expansion and hadronization of the QGP,leading to fnal-state hadron distributions that are observed experimentally.Recent advances in both experimental and theoretical methods have ushered in a precision era of heavy-ion collisions,enabling an increasingly accurate understanding of these stages.However,most approaches involve simultaneously determining both QGP properties and initial conditions from a single collision system,creating complexity due to the coupled contributions of these stages to the fnal-state observables.To avoid this,we propose leveraging established knowledge of low-energy nuclear structures and hydrodynamic observables to independently constrain the QGP's initial condition.By conducting comparative studies of collisions involving isobar-like nuclei—species with similar mass numbers but diferent ground-state geometries—we can disentangle the initial condition's impacts from the QGP properties.This approach not only refnes our understanding of the initial stages of the collisions but also turns high-energy nuclear experiments into a precision tool for imaging nuclear structures,ofering insights that complement traditional low-energy approaches.Opportunities for carrying out such comparative experiments at the Large Hadron Collider and other facilities could signifcantly advance both highenergy and low-energy nuclear physics.Additionally,this approach has implications for the future electron-ion collider.While the possibilities are extensive,we focus on selected proposals that could beneft both the high-energy and low-energy nuclear physics communities.Originally prepared as input for the long-range plan of U.S.nuclear physics,this white paper refects the status as of September 2022,with a brief update on developments since then.展开更多
In recent several years,the tensor force,one of the most important components of the nucleon-nucleon force,has been implemented in time-dependent density functional theories and it has been found to influence many asp...In recent several years,the tensor force,one of the most important components of the nucleon-nucleon force,has been implemented in time-dependent density functional theories and it has been found to influence many aspects of low-energy heavy-ion reactions,such as dissipation dynamics,sub-barrier fusions,and low-lying vibration states of colliding partners.Especially,the effects of tensor force on fusion reactions have been investigated from the internuclear potential to fusion crosssections systematically.In this work,we present a mini review on the recent progress on this topic.Considering the recent progress of low-energy reaction theories,we will also mention more possible effects of the tensor force on reaction dynamics.展开更多
The squeezed back-to-back correlation(SBBC)of a boson-antiboson pair is sensitive to the time distribution of the particle-emitting source,and the SBBC function for an evolving source is expected to be affected by the...The squeezed back-to-back correlation(SBBC)of a boson-antiboson pair is sensitive to the time distribution of the particle-emitting source,and the SBBC function for an evolving source is expected to be affected by the relaxation time of the system.In this study,we investigated the effect of relaxation time on the SBBC function.We propose a method for calculating the SBBC function with relaxation-time approximation for evolving sources.SBBC functions of D^(0)D^(-0)in relativistic heavy-ion collisions were investigated using a hydrodynamic model.We found that the relaxation time reduces the amplitudes of the SBBC functions.This becomes apparent for long relaxation times and large initial relative deviations of the chaotic and squeezed amplitudes from their equilibrium values in the temporal steps.展开更多
We investigate the squeezed back-to-back correlation（BBC） of D^0~0 in relativistic heavy-ion collisions, using the in-medium mass modification calculated with a self-energy in hot pion gas and the source space-time ...We investigate the squeezed back-to-back correlation（BBC） of D^0~0 in relativistic heavy-ion collisions, using the in-medium mass modification calculated with a self-energy in hot pion gas and the source space-time distributions provided by the viscous hydrodynamic code VISH2＋1. It is found that the squeezed BBC of D^0~0 is significant in peripheral Au＋Au collisions at the relativistic heavy ion collider energy. A possible way to detect the squeezed BBC in an experiment is presented.展开更多
Heavy-ion-acoustic(HIA) waves in an unmagnetized collisionless plasma system comprising superthermal electrons, Boltzmann distributed light ions, and adiabatic positively charged inertial heavy ions have been investig...Heavy-ion-acoustic(HIA) waves in an unmagnetized collisionless plasma system comprising superthermal electrons, Boltzmann distributed light ions, and adiabatic positively charged inertial heavy ions have been investigated both numerically and analytically. The well-known reductive perturbation method has been used to derive the Kortewegde Vries(K-d V) and Burgers(BG) equations. The parametric regimes for the existence of both the positive and negative solitary and shock waves have been obtained. The effects of adiabaticity of heavy ions and superthermality of electrons,which are found to notably modify the fundamental features(viz. polarity, amplitude, phase speed, etc.) of HIA solitary and shock waves, are precisely studied. The results of our theoretical investigation can be applicable to understand the characteristics and basic nonlinear structures of HIA waves both in space and laboratory plasma situations.展开更多
文摘An improved method is proposed for the extraction of the symmetry energy coefficient relative to the temperature,a_(sym)/T,in the heavy-ion reactions near the Fermi energy region,based on the modified Fisher Model.This method is applied to the primary fragments of antisymmetrized molecular dynamics(AMD)simulations for ^(46)Fe+^(46)Fe,^(40)Ca+^(40)Ca and ^(48)Ca+^(48)Ca at 35 MeV/nucleon,in order to make direct comparison to the results from the K(N,Z)method of Ono et al.In our improved method,the extracted values of a_(sym)/T increase as the size of isotopes increases whereas,in the K(N,Z)method,the results show rather constant behavior.This increase in our result is attributed to the surface contribution of the symmetry energy in finite nuclei.In order to evaluate the surface contribution,the relation a_(sym)/T=[a_(sym)^((V))(1-k_(S/V) A^(-1/3))]/T is applied and k_(S/V)=1.20~1.25 was extracted.This value is smaller than those extracted from the mass table,reflecting the weakened surface contribution at higher temperature regime.Δμ/T,the difference of the neutron-proton chemical potentials relative to the temperature,is also extracted in this method at the same time.The average values of the extractedΔμ/T,Δμ/T show a linear dependence on the proton-neutron a_(sym)metry parameter of the system,δ_(sys),andΔμ/T=(15.1±0.2)δ_(sys)-(0.5±0.1)is obtained.
基金National Key R&D Program of China(2017YFF0106501)Natural Science Foundation of Guangdong China(2016A030310042)+3 种基金Project funded by China Postdoctoral Science Foundation(2019M652999)National Natural Science Foundation of China(11575118,11605114,11490563)Continuous Basic Scientific Research Project(WDJC-2019-13)National key Research and Development Program of China(2016YFA0400502)。
文摘Experimental elastic scattering angular distributions of 11B,2C,and 16O+heavy-ions are used to studythe Woods-Saxon potential parameters.Best fitted values of the diffuseness parameters are found for each system,and a linear relationship is expressed between the diffuseness parameters and A1/31+A1/32.The correlation of the po-tential depth and radius parameters with A1/31+A1/32is also revealed within the limitations of the diffuseness parameter formula.Because the incident energies of most of the analyzed reactions are below or around the Coulombbarrier,the energy dispersion relation between the real and imaginary potentials is considered in order to investigatethe ratio between the imaginary and real potential well depths,resulting in an expression of W/V.Within the limitation of the volume integrals calculated with the Sao Paulo potential,parameterized formulas for the depth and radius parameters are obtained.The systematic Woods-Saxon potential parameters derived in the present work can reproduce not only the experimental data of elastic scattering angular distributions induced by 11B,12C,and 16O butalso some elastic scattering induced by other heavy-ions.
基金supported by the National Natural Science Foundation of China(NNSFC)(Nos.12375123,12205160,and 12335008)the Natural Science Foundation of Henan Province,China(No.242300421048)the postgraduate research and practice innovation project of Henan Normal University(No.YB202402).
文摘We developed a dedicated data analysis framework for silicon strip detector telescopes(SSDTs)of the Compact Spectrometer for Heavy-IoN Experiments(CSHINE)that addresses the challenges of processing complex signals.The framework integrates advanced algorithms for precise calibration,accurate particle identification,and efficient event reconstruction,aiming to account for critical experimental factors such as charge-sharing effects,multi-hit event resolution,and detector response nonuniformity.Its robust performance was demonstrated through the successful analysis of light-charged particles in the 25 MeV/u^(86)Kr+^(124)Sn experiment conducted at the first Radioactive Ion Beam Line in Lanzhou,allowing for precise extraction of physical observables,including energy,momentum,and particle type.Furthermore,utilizing the reconstructed physical information,such as the number of effective physical events and energy spectra to optimize the track recognition algorithm,the final track recognition efficiencies of approximately 90%were achieved.This framework establishes a valuable reference methodology for SSDT-based detector systems in heavy-ion reaction experiments,thereby significantly enhancing the accuracy and efficiency of data analysis in nuclear physics research.
基金supported by the National Key R&D Program of China(No.2022YFA1602302)the National Natural Science Foundation of China(Nos.U2167204,12175314,and 12235020)the Continuous-Support Basic Scientific Research Project.
文摘A heavy-ion time-of-flight spectrometer called HiToF,with magnet focusing accomplished by a quadrupole triplet lens,was constructed at the Beijing Tandem Accelerator National Laboratory,mainly for studies of multi-nucleon transfer reactions at energies near the Coulomb barrier.The spectrometer was equipped with a rotating chamber with a diameter of 40 cm and could be rotated over a large angular range from−40◦to 160◦.The length from the target to the focal plane is 2.7 m,enabling high-precision time-of-flight measurements using two microchannel plate detectors with a 1.9 m apart and a typical time resolution of 120 ps.A multisampling position-sensitive ionization chamber forΔE−E measurement is placed on the focal plane,which offers aΔZ∕Z resolution of 1/50.The setup provided a maximum solid angleΔΩ=20 msr.An experiment on^(32)S+^(90,94)Zr at a beam energy of 135 MeV was performed to test the performance.The projectile-like ions were identified with a mass resolution ofσ=0.2 amu.The results showed that the HiToF spectrometer is a powerful setup for studying heavy-ion reaction mechanisms at low energies.
文摘While the abundances of the final state hadrons in relativistic heavy-ion collisions are rather well described by the thermal particle production,the shape of the transverse momentum,pT,distribution below p_(T)≈500 MeV/c,is still poorly understood.We propose a procedure to quantify the model-to-data differences using Bayesian inference techniques,which allows for consistent treatment of the experimental uncertainties and tests the completeness of the available hydrodynamic frameworks.Using relativistic fluid framework FluiduM with PCE coupled to TrENTo initial state and FasTrEso decays,we analyze p_(T)distribution of identified charged hadrons measured in heavy-ion collisions at top RHIC and the LHC energies and identify an excess of pions produced below p_(T)≈500 MeV/c.Our results provide new input for the interpretation of the pion excess as either missing components in the thermal particle yield description or as an evidence for a different particle production mechanism.
文摘The derivation of the harmonic approximation of the Hamiltonian of a model of coupled three-dimensional harmonic oscillator is presented. It is shown how the splitting of the total Hamiltonian into the intrinsic and collective Hamiltonians leads to the description of the mechanism for energy dissipation in physical systems.
基金supported by Shanghai Natural Science Foundation(No.14ZR1403000)1000 Young Talents Program of China+2 种基金the National Natural Science Foundation of China(No.11535012)supported by China Postdoctoral Science Foundation under Grant No.2016M590312support from RIKEN-BNL Research Center
文摘The relativistic heavy-ion collisions create both hot quark–gluon matter and strong magnetic fields, and provide an arena to study the interplay between quantum chromodynamics and quantum electrodynamics. In recent years, it has been shown that such an interplay can generate a number of interesting quantum phenomena in hadronic and quark–gluon matter. In this short review, we first discuss some properties of the magnetic fields in heavy-ion collisions and then give an overview of the magnetic fieldinduced novel quantum effects. In particular, we focus on the magnetic effect on the heavy flavor mesons, the heavyquark transports, and the phenomena closely related to chiral anomaly.
基金supported by the National Natural Science Foundation of China(Nos.11675226 and 11722546)the Major State Basic Research Development Program of China(Nos.2014CB845405 and 2015CB856903)
文摘Recent progress of the quantum molecular dynamics model for describing the dynamics of heavy-ion collisions is viewed, in particular the nuclear fragmentation, isospin physics, particle production and in-medium effect, hadron-induced nuclear reactions, hypernucleus, etc.The neck fragmentation in Fermi-energy heavy-ion collisions is investigated for extracting the symmetry energy at subsaturation densities. The isospin effects, in-medium properties, and the behavior of high-density symmetry energy in medium-and high-energy heavy-ion collisions are thoroughly discussed. The hypernuclide dynamics formed in heavy-ion collisions and in hadron-induced reactions is analyzed and addressed in the future experiments at the high-intensity heavy-ion accelerator facility(HIAF).
基金the US Department of Energy(DOE)(No.DE-SC0013460)the National Science Foundation(NSF)(No.PHY-2012922)+1 种基金the National Natural Science Foundation of China(No.11975079)the US Department of Energy,Office of Science,Office of Nuclear Physics,within the framework of the Beam Energy Scan Theory(BEST)Topical Collaboration.
文摘We present a concise review of the recent development of relativistic hydrodynamics and its applications to heavy-ion collisions.Theoretical progress on the extended formulation of hydrodynamics toward out-ofequilibrium systems is addressed,with emphasis on the socalled attractor solution.Moreover,recent phenomenological improvements in the hydrodynamic modeling of heavy-ion collisions with respect to the ongoing beam energy scan program,the quantitative characterization of transport coefficients in three-dimensionally expanding quark–gluon plasma,the fluid description of small colliding systems,and certain other interdisciplinary connections are discussed.
基金supported by National Natural Science Foundation of China(Nos.11535012 and 11675041)。
文摘Relativistic heavy-ion collisions create hot quark–gluon plasma as well as very strong electromagnetic(EM)and fluid vortical fields.The strong EM field and vorticity can induce intriguing macroscopic quantum phenomena such as chiral magnetic,chiral separation,chiral electric separation,and chiral vortical effects as well as the spin polarization of hadrons.These phenomena provide us with experimentally feasible means to study the nontrivial topological sector of quantum chromodynamics,the possible parity violation of strong interaction at high temperature,and the subatomic spintronics of quark–gluon plasma.These studies,both in theory and in experiments,are strongly connected with other subfields of physics such as condensed matter physics,astrophysics,and cold atomic physics,and thus form an emerging interdisciplinary research area.We give an introduction to the aforementioned phenomena induced by the EM field and vorticity and an overview of the current status of experimental research in heavy-ion collisions.We also briefly discuss spin hydrodynamics as well as chiral and spin kinetic theories.
基金This work was supported by the National Natural Science Foundation of China(Nos.11575138,11835006,11690040,11690043,and 11705216)the Innovation Center of Radiation Application(No.KFZC2019050321)the China Scholarships Council program(No.201906280343).
文摘The propagation of single-event effects(SEEs)on a Xilinx Zynq-7000 system on chip(SoC)was inves-tigated using heavy-ion microbeam radiation.The irradia-tion results reveal several functional blocks’sensitivity locations and cross sections,for instance,the arithmetic logic unit,register,D-cache,and peripheral,while irradi-ating the on-chip memory(OCM)region.Moreover,event tree analysis was executed based on the obtained microbeam irradiation results.This study quantitatively assesses the probabilities of SEE propagation from the OCM to other blocks in the SoC.
基金supported in part by the National Natural Science Foundation of China(Nos.11890713,11890714,11835002,11961131011,11421505,11535012 and 11890713)the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB34030202 and XDB34030102)。
文摘We give a brief overview of recent theoretical and experimental results on the chiral magnetic effect and spin polarization effect in heavy-ion collisions.We present updated experimental results for the chiral magnetic effect and related phenomena.The time evolution of the magnetic fields in different models is discussed.The newly developed quantum kinetic theory for massive fermions is reviewed.We present theoretical and experimental results for the polarization of K hyperons and the q00 value of vector mesons.
基金This work is supported in part by the National Key Research and Development Program of China(Nos.2022YFA1604900)the Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030008)+3 种基金the National Natural Science Foundation of China(Nos.12275053,12025501,11890710,11890714,12147101,12075061,and 12225502)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB34030000)Shanghai National Science Foundation(No.20ZR1404100)STCSM(No.23590780100).
文摘Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic fields.In these collisions,highly charged fast-moving ions carry strong electromagnetic fields that can be effectively treated as photon fluxes.The exchange of photons can induce photonuclear and two-photon interactions and excite ions.This excitation of the ions results in Coulomb dissociation with the emission of photons,neutrons,and other particles.Additionally,the electromagnetic fields generated by the ions can be sufficiently strong to enforce mutual interactions between the two colliding ions.Consequently,the two colliding ions experience an electromagnetic force that pushes them in opposite directions,causing a back-to-back correlation in the emitted neutrons.Using a Monte Carlo simulation,we qualitatively demonstrate that the above electromagnetic effect is large enough to be observed in UPCs,which would provide a clear means to study strong electromagnetic fields and their effects.
基金supported from the National Natural Science Foundation of China(Grant Nos.11005158 and 9112600)the National major project of science and technology(Grant No.2012ZX06004-005-005)
文摘The swelling behavior of 20% cold-worked 15-15Ti steels with （0.23-0.40） wt% titanium and （0.42-0.81） wt% silicon content after heavy-ion beam irradiation has been investigated by transmission electron microscopy. The results show that 15-15Ti steel with higher titanium content displays lower swelling. As silicon content increases, the cavity size and the swelling of the 15-15Ti steels decrease obviously. Titanium and silicon may play important roles in suppressing the cavity nucleation and growth in 15-15Ti steel.
基金partly supported by the National Natural Science Foundation of China (Nos. U2032145 and 11875125)the National Key Research and Development Program of China (No. 2020YFE0202002)。
文摘In this study, the rapidity distribution, collective flows, and nuclear stopping power in ^(197)Au+^(197)Au collisions at intermediate energies were investigated using the ultrarelativistic quantum molecular dynamics(UrQMD) model with GEMINI++ code. The UrQMD model was adopted to simulate the dynamic evolution of heavy-ion collisions, whereas the GEMINI++ code was used to simulate the decay of primary fragments produced by UrQMD. The calculated results were compared with the INDRA and FOPI experimental data. It was found that the rapidity distribution, collective flows, and nuclear stopping power were affected to a certain extent by the decay of primary fragments, especially at lower beam energies. Furthermore, the experimental data of the collective flows and nuclear stopping power at the investigated beam energies were better reproduced when the sequential decay effect was included.
基金U.S.Department of Energy,Office of Science,Ofifce of Nuclear Physics,under Award or Contract No.DE-SC002418(JDB),DE-SC0024602(SH,JJ,CZ),DE-SC0004286(UH),DE-FG02-10ER41666(CL,WL),DE-SC0013365,DE-SC0024586 and DE-SC0023175(DL),DE-SC0011088(YL),DE-AC02-05CH11231(MP),DE-FG02-89ER40531(AT),DE-SC0012704(BS),DE-SC0021969 and DE-SC0024232(CS),DE-SC0023861(JN),DE-FG02-07ER41521(ZX)by National Science Foundation under grant number OAC-2103680(JN)+1 种基金by European Union(ERC,Initial Conditions),VILLUM FONDEN with grant no.00025462,and Danmarks Frie Forskningsfond(YZ)by FAPESP projects 2017/05685-2,2018/24720-6,and 2021/08465-9,project INCT-FNA Proc.~No.~464898/2014-5,and CAPES-Finance Code 001(ML)。
文摘High-energy nuclear collisions encompass three key stages:the structure of the colliding nuclei,informed by low-energy nuclear physics,the initial condition,leading to the formation of quark-gluon plasma(QGP),and the hydrodynamic expansion and hadronization of the QGP,leading to fnal-state hadron distributions that are observed experimentally.Recent advances in both experimental and theoretical methods have ushered in a precision era of heavy-ion collisions,enabling an increasingly accurate understanding of these stages.However,most approaches involve simultaneously determining both QGP properties and initial conditions from a single collision system,creating complexity due to the coupled contributions of these stages to the fnal-state observables.To avoid this,we propose leveraging established knowledge of low-energy nuclear structures and hydrodynamic observables to independently constrain the QGP's initial condition.By conducting comparative studies of collisions involving isobar-like nuclei—species with similar mass numbers but diferent ground-state geometries—we can disentangle the initial condition's impacts from the QGP properties.This approach not only refnes our understanding of the initial stages of the collisions but also turns high-energy nuclear experiments into a precision tool for imaging nuclear structures,ofering insights that complement traditional low-energy approaches.Opportunities for carrying out such comparative experiments at the Large Hadron Collider and other facilities could signifcantly advance both highenergy and low-energy nuclear physics.Additionally,this approach has implications for the future electron-ion collider.While the possibilities are extensive,we focus on selected proposals that could beneft both the high-energy and low-energy nuclear physics communities.Originally prepared as input for the long-range plan of U.S.nuclear physics,this white paper refects the status as of September 2022,with a brief update on developments since then.
基金supported by the National Natural Science Foundation of China(Grants No.11975237,No.11575189,and No.11790325)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB34010000 and No.XDPB15)
文摘In recent several years,the tensor force,one of the most important components of the nucleon-nucleon force,has been implemented in time-dependent density functional theories and it has been found to influence many aspects of low-energy heavy-ion reactions,such as dissipation dynamics,sub-barrier fusions,and low-lying vibration states of colliding partners.Especially,the effects of tensor force on fusion reactions have been investigated from the internuclear potential to fusion crosssections systematically.In this work,we present a mini review on the recent progress on this topic.Considering the recent progress of low-energy reaction theories,we will also mention more possible effects of the tensor force on reaction dynamics.
基金supported by the National Natural Science Foundation of China (Nos. 12175031 and 11675034)
文摘The squeezed back-to-back correlation(SBBC)of a boson-antiboson pair is sensitive to the time distribution of the particle-emitting source,and the SBBC function for an evolving source is expected to be affected by the relaxation time of the system.In this study,we investigated the effect of relaxation time on the SBBC function.We propose a method for calculating the SBBC function with relaxation-time approximation for evolving sources.SBBC functions of D^(0)D^(-0)in relativistic heavy-ion collisions were investigated using a hydrodynamic model.We found that the relaxation time reduces the amplitudes of the SBBC functions.This becomes apparent for long relaxation times and large initial relative deviations of the chaotic and squeezed amplitudes from their equilibrium values in the temporal steps.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11675034,11647166 and 11675033
文摘We investigate the squeezed back-to-back correlation（BBC） of D^0~0 in relativistic heavy-ion collisions, using the in-medium mass modification calculated with a self-energy in hot pion gas and the source space-time distributions provided by the viscous hydrodynamic code VISH2＋1. It is found that the squeezed BBC of D^0~0 is significant in peripheral Au＋Au collisions at the relativistic heavy ion collider energy. A possible way to detect the squeezed BBC in an experiment is presented.
文摘Heavy-ion-acoustic(HIA) waves in an unmagnetized collisionless plasma system comprising superthermal electrons, Boltzmann distributed light ions, and adiabatic positively charged inertial heavy ions have been investigated both numerically and analytically. The well-known reductive perturbation method has been used to derive the Kortewegde Vries(K-d V) and Burgers(BG) equations. The parametric regimes for the existence of both the positive and negative solitary and shock waves have been obtained. The effects of adiabaticity of heavy ions and superthermality of electrons,which are found to notably modify the fundamental features(viz. polarity, amplitude, phase speed, etc.) of HIA solitary and shock waves, are precisely studied. The results of our theoretical investigation can be applicable to understand the characteristics and basic nonlinear structures of HIA waves both in space and laboratory plasma situations.
