The experimental data concerning the58Ni+48Ca reaction at Elab(Ni)=25A MeV,collected by using the CHIMERA 4π device,have been analyzed in order to investigate the competition among different reaction mechanisms for c...The experimental data concerning the58Ni+48Ca reaction at Elab(Ni)=25A MeV,collected by using the CHIMERA 4π device,have been analyzed in order to investigate the competition among different reaction mechanisms for central collisions in the Fermi energy domain.As a main criterion for centrality selection we have chosen the flow angle(flow) method,making an event-by-event analysis that considers the shape of events,as it is determined by the eigenvectors of the experimental kinetic-energy tensor.For the selected central events(flow >60°) some global variables,good to characterize the pattern of central collisions have been constructed.The main features of the reaction products were explored by using different constraints on some of the relevant observables,like mass and velocity distributions and their correlations.Much emphasis was devoted,for central collisions,to the competition between fusion-evaporation processes with subsequent identification of a heavy residue and a possible multifragmentation mechanism of a well defined(if any) transient nuclear system.Dynamical evolution of the system and pre-equilibrium emission were taken into account by simulating the reactions in the framework of transport theories.Different approaches have been envisaged(dynamical stochastic BNV calculations + sequential SIMON code,QMD,CoMD,etc.).Preliminary comparison of the experimental data with BNV calculations shows reasonable agreement with the assumption of sequential multifragmentation emission in the mass region of IMFs close to the heavy residues.Possible deviations from sequential processes were found for those IMFs in the region of masses intermediate between the mass of heavy residues and the mass of light IMFs.Further simulations are in progress.The experimental analysis will be enriched also by information obtained inspecting the IMF-IMF correlation function,in order to elucidated the nature of space-time decay property of the emitting source associated with events having the largest IMF multiplicity.展开更多
The collective flow for <sup>64</sup>Zn+<sup>27</sup>Al system is measured at intermediate energyby using a 4π multidetector array in conjunction with an array of Si telescopes.Theevents have ...The collective flow for <sup>64</sup>Zn+<sup>27</sup>Al system is measured at intermediate energyby using a 4π multidetector array in conjunction with an array of Si telescopes.Theevents have been sorted versus the impact parameter by means of global variables.Three methods of reaction plane determination are compared:sphericity tensor method,transverse momentum analysis,and azimuthal correlation method.For this system,thetransverse momentum analysis method is the best one.展开更多
In this white paper,we present the potential of the enhanced X-ray timing and polarimetry(eXTP)mission to constrain the equation of state of dense matter in neutron stars,exploring regimes not directly accessible to t...In this white paper,we present the potential of the enhanced X-ray timing and polarimetry(eXTP)mission to constrain the equation of state of dense matter in neutron stars,exploring regimes not directly accessible to terrestrial experiments.By observing a diverse population of neutron stars—including isolated objects,X-ray bursters,and accreting systems—eXTP’s unique combination of timing,spectroscopy,and polarimetry enables high-precision measurements of compactness,spin,surface temperature,polarimetric signals,and timing irregularity.These multifaceted observations,combined with advances in theoretical modeling,pave the way toward a comprehensive description of the properties and phases of dense matter from the crust to the core of neutron stars.Under development by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Sciences,the eXTP mission is planned to be launched in early 2030.展开更多
文摘The experimental data concerning the58Ni+48Ca reaction at Elab(Ni)=25A MeV,collected by using the CHIMERA 4π device,have been analyzed in order to investigate the competition among different reaction mechanisms for central collisions in the Fermi energy domain.As a main criterion for centrality selection we have chosen the flow angle(flow) method,making an event-by-event analysis that considers the shape of events,as it is determined by the eigenvectors of the experimental kinetic-energy tensor.For the selected central events(flow >60°) some global variables,good to characterize the pattern of central collisions have been constructed.The main features of the reaction products were explored by using different constraints on some of the relevant observables,like mass and velocity distributions and their correlations.Much emphasis was devoted,for central collisions,to the competition between fusion-evaporation processes with subsequent identification of a heavy residue and a possible multifragmentation mechanism of a well defined(if any) transient nuclear system.Dynamical evolution of the system and pre-equilibrium emission were taken into account by simulating the reactions in the framework of transport theories.Different approaches have been envisaged(dynamical stochastic BNV calculations + sequential SIMON code,QMD,CoMD,etc.).Preliminary comparison of the experimental data with BNV calculations shows reasonable agreement with the assumption of sequential multifragmentation emission in the mass region of IMFs close to the heavy residues.Possible deviations from sequential processes were found for those IMFs in the region of masses intermediate between the mass of heavy residues and the mass of light IMFs.Further simulations are in progress.The experimental analysis will be enriched also by information obtained inspecting the IMF-IMF correlation function,in order to elucidated the nature of space-time decay property of the emitting source associated with events having the largest IMF multiplicity.
文摘The collective flow for <sup>64</sup>Zn+<sup>27</sup>Al system is measured at intermediate energyby using a 4π multidetector array in conjunction with an array of Si telescopes.Theevents have been sorted versus the impact parameter by means of global variables.Three methods of reaction plane determination are compared:sphericity tensor method,transverse momentum analysis,and azimuthal correlation method.For this system,thetransverse momentum analysis method is the best one.
基金supported by China’s Space Origins Exploration Programsupported by the National Natural Science Foundation of China (Grant No.12273028)+36 种基金support from ERC Consolidator (Grant No.865768) AEONSsupport from NWO grant ENW-XL OCENW.XL21.XL21.038the support of the CNESsupported by the National Natural Science Foundation of China (Grant No.12333007)the International Partnership Program of Chinese Academy of Sciences (Grant No.113111KYSB20190020)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDA15020100)supported by the China National Postdoctoral Program for Innovation Talents (Grant No.BX20240223)the China Postdoctoral Science Foundation Funded Project (Grant No.2024M761948)support from a Ramon y Cajal fellowship (Grant No.RYC2021-032718-I) financed by MCIN/AEI/10.13039/501100011033 and the European Union Next Generation EU/PRTRsupported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region (Grant No.2023D01E20)the National SKA Program of China (Grant No.2020SKA0120300)supported by the National Natural Science Foundation of China (Grant Nos.12033001,and 12473039)supported by Zhejiang Provincial Natural Science Foundation of China (Grant No.LQ24A030002)supported by the National Natural Science Foundation of China (Grant No.12003009)supported by the National SKA Program of China (Grant No.2020SKA0120200)the National Natural Science Foundation of China (Grant No.12041303)supported by the National Natural Science Foundation of China (Grant No.1227303)supported by the National SKA Program of China (Grant No.2020SKA0120300)the Beijing Natural Science Foundation (Grant No.1242018)the Max Planck Partner Group Program funded by the Max Planck Societysupported by JSPS KAKENHI (the Japan Society for the Promotion of Science,Grantsin-Aid for Scientific Research) (Grant Nos.23K19056,and 25K17403)supported by the National Natural Science Foundation of China (Grant No.12175109)support from FCT (Fundacao para a Ciência e a Tecnologia,I.P.,Portugal) (Grant Nos.UIDB/04564/2020,and 2022.06460.PTDC)supported from the program Unidad de Excelencia María de Maeztu CEX2020-001058-Mfrom the project PID2022-139427NB-I00 financed by the Spanish MCIN/AEI/10.13039/501100011033/FEDER,UE (FSE+)by the CRC-TR 211 “Strong-interaction matter under extreme conditions” -project Nr.315477589-TRR 211support from grant PID2021-124581OB-I0,PID2024-155316NB-I00,and 2021SGR00426supported by the National Natural Science Foundation of China (Grant No.12122513)supported in part by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant No.101020842)by the Deutsche Forschungsgemeinschaft (DFG,German Research Foundation)-Project-ID 279384907-SFB 1245support from the ERC Consolidator (Grant No.101002352) (LOVENEST)supported by the European Research Council (ERC) via the Consolidator Grant “MAGNESIA” (Grant No.817661)the Proof of Concept “Deep Space Pulse” (Grant No.101189496)the Catalan grant SGR2021-01269the Spanish grant ID2023-153099NA-I00the program Unidad de Excelencia Maria de Maeztu CEX2020-001058-Msupported by the Research Council of Finland (Grant No.354533).
文摘In this white paper,we present the potential of the enhanced X-ray timing and polarimetry(eXTP)mission to constrain the equation of state of dense matter in neutron stars,exploring regimes not directly accessible to terrestrial experiments.By observing a diverse population of neutron stars—including isolated objects,X-ray bursters,and accreting systems—eXTP’s unique combination of timing,spectroscopy,and polarimetry enables high-precision measurements of compactness,spin,surface temperature,polarimetric signals,and timing irregularity.These multifaceted observations,combined with advances in theoretical modeling,pave the way toward a comprehensive description of the properties and phases of dense matter from the crust to the core of neutron stars.Under development by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Sciences,the eXTP mission is planned to be launched in early 2030.
