Within a transport model,we investigated the effects of the momentum dependence of the nuclear symmetry potential on the pion observables in central Sn+Sn collisions at 270 MeV/nucleon.To this end,the quantity U^(∞)_...Within a transport model,we investigated the effects of the momentum dependence of the nuclear symmetry potential on the pion observables in central Sn+Sn collisions at 270 MeV/nucleon.To this end,the quantity U^(∞)_(sym)(ρ_(0))(i.e.,the value of the nuclear symmetry potential at the saturation densityρ_(0) and infinitely large nucleon momentum)was used to characterize the momentum dependence of the nuclear symmetry potential.With a certain L(i.e.,the slope of the nuclear symmetry energy at(ρ_(0))),the characteristic parameter U^(∞)_(sym)(ρ_(0))of the symmetry potential significantly affects the production of−and+and their pion ratios.Moreover,by comparing the charged pion yields,pion ratios,and spectral pion ratios of the theoretical simulations for the reactions ^(108) Sn+^(112) Sn and ^(132)Sn+^(124)Sn with the corresponding data in the SRIT experiments,we found that our results favor a constraint on U^(∞)_(sym)(ρ_(0))(i.e.,−160_(−9)^(+18) MeV),and L is also suggested within a range of 62.7 MeV<L<93.1 MeV.In addition,the pion observable for^(197)Au+^(197)Au collisions at 400 MeV/nucleon also supports the extracted value for U^(∞)_(sym)(ρ_(0)).展开更多
基金supported by the National Natural Science Foundation of China(Nos.11965008 and 11405128)the Guizhou Provincial Science and Technology Foundation(No.[2020]1Y034)the PhD-funded project of Guizhou Normal University(No.GZNUD[2018]11).
文摘Within a transport model,we investigated the effects of the momentum dependence of the nuclear symmetry potential on the pion observables in central Sn+Sn collisions at 270 MeV/nucleon.To this end,the quantity U^(∞)_(sym)(ρ_(0))(i.e.,the value of the nuclear symmetry potential at the saturation densityρ_(0) and infinitely large nucleon momentum)was used to characterize the momentum dependence of the nuclear symmetry potential.With a certain L(i.e.,the slope of the nuclear symmetry energy at(ρ_(0))),the characteristic parameter U^(∞)_(sym)(ρ_(0))of the symmetry potential significantly affects the production of−and+and their pion ratios.Moreover,by comparing the charged pion yields,pion ratios,and spectral pion ratios of the theoretical simulations for the reactions ^(108) Sn+^(112) Sn and ^(132)Sn+^(124)Sn with the corresponding data in the SRIT experiments,we found that our results favor a constraint on U^(∞)_(sym)(ρ_(0))(i.e.,−160_(−9)^(+18) MeV),and L is also suggested within a range of 62.7 MeV<L<93.1 MeV.In addition,the pion observable for^(197)Au+^(197)Au collisions at 400 MeV/nucleon also supports the extracted value for U^(∞)_(sym)(ρ_(0)).
