{"title":"Hadron–quark phase transition in the context of GW190814","authors":"I. A. Rather, A. A. Usmani, S. Patra","doi":"10.1088/1361-6471/ac0129","DOIUrl":"https://doi.org/10.1088/1361-6471/ac0129","url":null,"abstract":"The properties of the neutron stars are calculated for the hadronic matter within the density-dependent relativistic mean-field model (DD-RMF). The phase transition to the quark matter is studied and the hybrid star matter properties are systematically calculated using the Vector-Enhanced Bag model (vBag). The maximum mass of neutron star with DD-LZ1 and DD-RMF parameter sets is found to be around 2.55$M_{odot}$ for pure hadronic phase and around 2$M_{odot}$ for hadron-quark mixed phase using both Gibbs and Maxwell construction. The tidal deformability for the hybrid EoS at 1.4$M_{odot}$, $Lambda_{1.4}$, remains unchanged from the pure hadronic EoS with Maxwell construction, but decreases with the increasing neutron star mass for Gibbs construction. While the pure hadron matter EoS satisfies the mass constraint from recently observed GW190814 data, the star matter properties for the hadron-quark phase transition satisfy the constraints from the recent observations GW170817. Therefore, we cannot exclude the possibility of the secondary object in GW190814 as a neutron star composed of hadrons and quarks.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82947830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fusion reaction of a weakly bound nucleus with a deformed target","authors":"K. Choi, K. S. Kim, M. Cheoun, W. So, K. Hagino","doi":"10.1103/PHYSREVC.103.034611","DOIUrl":"https://doi.org/10.1103/PHYSREVC.103.034611","url":null,"abstract":"We discuss the role of deformation of the target nucleus in the fusion reaction of the $^{15}$C + $^{232}$Th system at energies around the Coulomb barrier, for which $^{15}$C is a well-known one-neutron halo nucleus. To this end, we construct the potential between $^{15}$C and $^{232}$Th with the double folding procedure, assuming that the projectile nucleus is composed of the core nucleus, $^{14}$C, and a valance neutron. By taking into account the halo nature of the projectile nucleus as well as the deformation of the target nucleus, we simultaneously reproduce the fusion cross sections for the $^{14}$C + $^{232}$Th and the $^{15}$C + $^{232}$Th systems. Our calculation indicates that the net effect of the breakup and the transfer channels is small for this system.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85918921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Quark-hadron crossover equations of state for neutron stars: Constraining the chiral invariant mass in a parity doublet model","authors":"Takuya Minamikawa, T. Kojo, M. Harada","doi":"10.1103/PHYSREVC.103.045205","DOIUrl":"https://doi.org/10.1103/PHYSREVC.103.045205","url":null,"abstract":"We construct an equation of state (EOS) for neutron stars by interpolating hadronic EOS at low density and quark EOS at high density. A hadronic model based on the parity doublet structure is used for hadronic matter and a quark model of Nambu--Jona-Lasinio type is for quark matter. We assume crossover between hadronic matter and quark matter in the the color-flavor locked phase. The nucleon mass of the parity doublet model has a mass associated with the chiral symmetry breaking, and a chiral invariant mass $m_0$ which is insensitive to the chiral condensate. The value of $m_0$ affects the nuclear EOSs at low density, and has strong correlations with the radii of neutron stars. Using the constraint to the radius obtained by LIGO-Virgo and NICER, we find that $m_0$ is restricted as $700,mathrm{MeV}lesssim m_0 lesssim 900,mathrm{MeV}$.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78307767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Consistent description for cluster dynamics and single-particle correlation","authors":"N. Itagaki, T. Naito","doi":"10.1103/PHYSREVC.103.044303","DOIUrl":"https://doi.org/10.1103/PHYSREVC.103.044303","url":null,"abstract":"Cluster dynamics and single-particle correlation are simultaneously treated for the description of the ground state of ${}^{12} mathrm{C} $. The recent development of the antisymmetrized quasi cluster model (AQCM) makes it possible to generate $jj$-coupling shell-model wave functions from $alpha$ clusters models. The cluster dynamics and the competition with the $jj$-coupling shell-model structure can be estimated rather easily. In the present study, we further include the effect of single-particle excitation; the mixing of the two-particle-two-hole excited states is considered. The single-particle excitation is not always taken into account in the standard cluster model analyses, and the two-particle-two-hole states are found to strongly contribute to the lowering of the ground state owing to the pairing-like correlations. By extending AQCM, all of the basis states are prepared on the same footing, and they are superposed based on the framework of the generator coordinate method (GCM).","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89035273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Learning about the structure of giant resonances from their \u0000γ\u0000 decay","authors":"W. Lv, Y. Niu, G. Colò","doi":"10.1103/PhysRevC.103.064321","DOIUrl":"https://doi.org/10.1103/PhysRevC.103.064321","url":null,"abstract":"The direct $gamma$-decays of the giant dipole resonance (GDR) and the giant quadrupole resonance (GQR) of $^{208}$Pb to low-lying states are investigated by means of a microscopic self-consistent model. The model considers effects beyond the linear response approximation. The strong sensitivity of $gamma$-decay to the isospin of the involved states is proven. By comparing their decay widths, a much larger weight of the $3_{1}^{-}$ component in the GQR wave function of $^{208}$Pb is deduced, with respect to the weight of the $2_{1}^{+}$ component in the GDR wave function. Thus, we have shown that $gamma$-decay is a unique probe of the resonance wave functions, and a testground for nuclear structure models.","PeriodicalId":8463,"journal":{"name":"arXiv: Nuclear Theory","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84787675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}