Taking into account nucleon-nucleon gravitational interaction, higher-order terms of symmetry energy, pairing interaction, and neural network corrections, a new BW4 mass model has been developed, which more accurately reflects the contributions of various terms to the binding energy. A novel hybrid algorithm and neural network correction method has been implemented to optimize the discrepancy between theoretical and experimental results, significantly improving the model's binding energy predictions (reduced to around 350 keV). At the same time, the theoretical accuracy near magic nuclei has been marginally enhanced, effectively capturing the special interaction effects around magic nuclei and showing good agreement with experimental data.
{"title":"Optimization of Nuclear Mass Models Using Algorithms and Neural Networks","authors":"Jin Li, Hang Yang","doi":"arxiv-2409.11930","DOIUrl":"https://doi.org/arxiv-2409.11930","url":null,"abstract":"Taking into account nucleon-nucleon gravitational interaction, higher-order\u0000terms of symmetry energy, pairing interaction, and neural network corrections,\u0000a new BW4 mass model has been developed, which more accurately reflects the\u0000contributions of various terms to the binding energy. A novel hybrid algorithm\u0000and neural network correction method has been implemented to optimize the\u0000discrepancy between theoretical and experimental results, significantly\u0000improving the model's binding energy predictions (reduced to around 350 keV).\u0000At the same time, the theoretical accuracy near magic nuclei has been\u0000marginally enhanced, effectively capturing the special interaction effects\u0000around magic nuclei and showing good agreement with experimental data.","PeriodicalId":501573,"journal":{"name":"arXiv - PHYS - Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263259","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}
Reliable photo-nuclear reaction rates at the stellar conditions are essential to understand the origin of the heavy stable neutron-deficient isotopes between $^{74}$Se and $^{196}$Hg-p-nuclei, however, many reaction rates of relevance still have to rely on the Hauser-Feshbach model due to rare experimental progress. One such case is in the mass range of 160 for Dy, Er, Ho and Tm isotopes. In this work we attempt to constrain the Hauser-Feshbach model in the TALYS package by reproducing the available experimental data of $^{160}$Dy($p,gamma$)$^{161}$Ho and $^{162}$Er($p,gamma$)$^{163}$Tm in the $Asim 160$ mass region, and examine the effects of level density, gamma strength function and the optical model potential. The constrained model then allows us to calculate the reaction rates of $^{157, 159}$Ho($gamma$, $p$) and $^{163,165}$Tm($gamma$, $p$) for the $gamma$-process nucleosynthesis in carbon-deflagration SNe Ia model. Our recommended rates differ from the JINA REACLIB by more than 1 order of magnitude in the temperature range of 2-3 GK. This results in the changes of final abundance of $p$-nuclei in the $Asim 160$ mass range by -5.5-3% from those with JINA, which means that the ($gamma$, $p$) reactions uncertainty is not predominant for the synthesis of these nuclei.
{"title":"Photo-nuclear reaction rates of $^{157,159}$Ho and $^{163,165}$Tm and their impact in the $γ$--process","authors":"Hao Cheng, Bao-Hua Sun, Li-Hua Zhu, Motohiko Kusakabe, Yudong Luo, Toshitaka Kajino, Chang-Jian Wang, Xing-Qun Yao, Chuang-Ye He, Fu-Long Liu, Bing Guo","doi":"arxiv-2409.11710","DOIUrl":"https://doi.org/arxiv-2409.11710","url":null,"abstract":"Reliable photo-nuclear reaction rates at the stellar conditions are essential\u0000to understand the origin of the heavy stable neutron-deficient isotopes between\u0000$^{74}$Se and $^{196}$Hg-p-nuclei, however, many reaction rates of relevance\u0000still have to rely on the Hauser-Feshbach model due to rare experimental\u0000progress. One such case is in the mass range of 160 for Dy, Er, Ho and Tm\u0000isotopes. In this work we attempt to constrain the Hauser-Feshbach model in the\u0000TALYS package by reproducing the available experimental data of\u0000$^{160}$Dy($p,gamma$)$^{161}$Ho and $^{162}$Er($p,gamma$)$^{163}$Tm in the\u0000$Asim 160$ mass region, and examine the effects of level density, gamma\u0000strength function and the optical model potential. The constrained model then\u0000allows us to calculate the reaction rates of $^{157, 159}$Ho($gamma$, $p$) and\u0000$^{163,165}$Tm($gamma$, $p$) for the $gamma$-process nucleosynthesis in\u0000carbon-deflagration SNe Ia model. Our recommended rates differ from the JINA\u0000REACLIB by more than 1 order of magnitude in the temperature range of 2-3 GK.\u0000This results in the changes of final abundance of $p$-nuclei in the $Asim 160$\u0000mass range by -5.5-3% from those with JINA, which means that the ($gamma$,\u0000$p$) reactions uncertainty is not predominant for the synthesis of these\u0000nuclei.","PeriodicalId":501573,"journal":{"name":"arXiv - PHYS - Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263261","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}
Marcus Bluhm, Yuki Fujimoto, Larry McLerran, Marlene Nahrgang
We determine the onset of Quarkyonic Matter corresponding to values of temperature and baryon chemical potential at which the quark phase space density becomes one. At zero temperature for baryon chemical potentials below the mass of the Lambda baryon, only nucleons contribute to the quark density. This is different at finite temperature, where all baryons, mesons and their resonances can be excited and thus add quarks to the phase space. The probability density to find a quark inside a hadron is determined using the Yukawa ansatz of the IdylliQ model of Quarkyonic Matter. We estimate separately the magnitude of the various contributions of nucleons, Delta baryons, pions as well as further hadrons and resonances. The uncertainty in the parametrization of the probability density to find a quark inside a nucleon is spanned by assuming that at zero temperature the transition density to Quarkyonic Matter is between one and three times that of nuclear matter. Various predictions for a possible critical point associated with the chiral phase transition are found close to a triple point at which the line of the deconfinement transition and the curve associated with the transition to Quarkyonic Matter intersect. These considerations provide an estimate for the region in the QCD phase diagram where Quarkyonic Matter may be found.
{"title":"Quark saturation in the QCD phase diagram","authors":"Marcus Bluhm, Yuki Fujimoto, Larry McLerran, Marlene Nahrgang","doi":"arxiv-2409.12088","DOIUrl":"https://doi.org/arxiv-2409.12088","url":null,"abstract":"We determine the onset of Quarkyonic Matter corresponding to values of\u0000temperature and baryon chemical potential at which the quark phase space\u0000density becomes one. At zero temperature for baryon chemical potentials below\u0000the mass of the Lambda baryon, only nucleons contribute to the quark density.\u0000This is different at finite temperature, where all baryons, mesons and their\u0000resonances can be excited and thus add quarks to the phase space. The\u0000probability density to find a quark inside a hadron is determined using the\u0000Yukawa ansatz of the IdylliQ model of Quarkyonic Matter. We estimate separately\u0000the magnitude of the various contributions of nucleons, Delta baryons, pions as\u0000well as further hadrons and resonances. The uncertainty in the parametrization\u0000of the probability density to find a quark inside a nucleon is spanned by\u0000assuming that at zero temperature the transition density to Quarkyonic Matter\u0000is between one and three times that of nuclear matter. Various predictions for\u0000a possible critical point associated with the chiral phase transition are found\u0000close to a triple point at which the line of the deconfinement transition and\u0000the curve associated with the transition to Quarkyonic Matter intersect. These\u0000considerations provide an estimate for the region in the QCD phase diagram\u0000where Quarkyonic Matter may be found.","PeriodicalId":501573,"journal":{"name":"arXiv - PHYS - Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263257","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}
Vincenzo NugaraDepartment of Physics and Astronomy, University of Catania, CataniaINFN-Laboratori Nazionali del Sud, Catania, Italy, Vincenzo GrecoDepartment of Physics and Astronomy, University of Catania, CataniaINFN-Laboratori Nazionali del Sud, Catania, Italy, Salvatore PlumariDepartment of Physics and Astronomy, University of Catania, CataniaINFN-Laboratori Nazionali del Sud, Catania, Italy
We employ the Full Relativistic Boltzmann Transport approach for a conformal system in 3+1D to study the universal behaviour in moments of the distribution function and anisotropic flows. We investigate different transverse system sizes $R$ and interaction strength $eta/s$ and identify universality classes based upon the interplay between $R$ and the mean free path; we show that each of this classes can be identified by a particular value of the opacity $hat gamma$, which has been previously introduced in literature. Our results highlight that, at early times, the inverse Reynolds number and momentum moments of the distribution function display universal behaviour, converging to a 1D attractor driven by longitudinal expansion. This indicates that systems of different sizes and interaction strengths tend to approach equilibrium in a similar manner. We provide a detailed analysis of how the onset of transverse flow affects these moments at later times. Moreover, we investigate the system size and $eta/s$ dependence for the harmonic flows $v_2$, $v_3$, $v_4$ and their response functions, along with the impact of the $eta/s$ and the system transverse size on the dissipation of initial azimuthal correlations in momentum space. Finally, we introduce the normalised elliptic flow $v_2/v_{2,eq}$, showing the emergence of attractor behaviour in the regime of large opacity. These results offer new insights into how different systems evolve towards equilibrium and the role that system size and interaction play in this process.
{"title":"Far-from-equilibrium attractors with Full Relativistic Boltzmann approach in 3+1 D: moments of distribution function and anisotropic flows $v_n$","authors":"Vincenzo NugaraDepartment of Physics and Astronomy, University of Catania, CataniaINFN-Laboratori Nazionali del Sud, Catania, Italy, Vincenzo GrecoDepartment of Physics and Astronomy, University of Catania, CataniaINFN-Laboratori Nazionali del Sud, Catania, Italy, Salvatore PlumariDepartment of Physics and Astronomy, University of Catania, CataniaINFN-Laboratori Nazionali del Sud, Catania, Italy","doi":"arxiv-2409.12123","DOIUrl":"https://doi.org/arxiv-2409.12123","url":null,"abstract":"We employ the Full Relativistic Boltzmann Transport approach for a conformal\u0000system in 3+1D to study the universal behaviour in moments of the distribution\u0000function and anisotropic flows. We investigate different transverse system\u0000sizes $R$ and interaction strength $eta/s$ and identify universality classes\u0000based upon the interplay between $R$ and the mean free path; we show that each\u0000of this classes can be identified by a particular value of the opacity $hat\u0000gamma$, which has been previously introduced in literature. Our results\u0000highlight that, at early times, the inverse Reynolds number and momentum\u0000moments of the distribution function display universal behaviour, converging to\u0000a 1D attractor driven by longitudinal expansion. This indicates that systems of\u0000different sizes and interaction strengths tend to approach equilibrium in a\u0000similar manner. We provide a detailed analysis of how the onset of transverse\u0000flow affects these moments at later times. Moreover, we investigate the system\u0000size and $eta/s$ dependence for the harmonic flows $v_2$, $v_3$, $v_4$ and\u0000their response functions, along with the impact of the $eta/s$ and the system\u0000transverse size on the dissipation of initial azimuthal correlations in\u0000momentum space. Finally, we introduce the normalised elliptic flow\u0000$v_2/v_{2,eq}$, showing the emergence of attractor behaviour in the regime of\u0000large opacity. These results offer new insights into how different systems\u0000evolve towards equilibrium and the role that system size and interaction play\u0000in this process.","PeriodicalId":501573,"journal":{"name":"arXiv - PHYS - Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263260","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}
Florian Brökemeier, S. Momme Hengstenberg, James W. T. Keeble, Caroline E. P. Robin, Federico Rocco, Martin J. Savage
Motivated by the Gottesman-Knill theorem, we present a detailed study of the quantum complexity of $p$-shell and $sd$-shell nuclei. Valence-space nuclear shell-model wavefunctions generated by the BIGSTICK code are mapped to qubit registers using the Jordan-Wigner mapping (12 qubits for the $p$-shell and 24 qubits for the $sd$-shell), from which measures of the many-body entanglement ($n$-tangles) and magic (non-stabilizerness) are determined. While exact evaluations of these measures are possible for nuclei with a modest number of active nucleons, Monte Carlo simulations are required for the more complex nuclei. The broadly-applicable Pauli-String $IZ$ exact (PSIZe-) MCMC technique is introduced to accelerate the evaluation of measures of magic in deformed nuclei (with hierarchical wavefunctions), by factors of $sim 8$ for some nuclei. Significant multi-nucleon entanglement is found in the $sd$-shell, dominated by proton-neutron configurations, along with significant measures of magic. This is evident not only for the deformed states, but also for nuclei on the path to instability via regions of shape coexistence and level inversion. These results indicate that quantum-computing resources will accelerate precision simulations of such nuclei and beyond.
{"title":"Quantum Magic and Multi-Partite Entanglement in the Structure of Nuclei","authors":"Florian Brökemeier, S. Momme Hengstenberg, James W. T. Keeble, Caroline E. P. Robin, Federico Rocco, Martin J. Savage","doi":"arxiv-2409.12064","DOIUrl":"https://doi.org/arxiv-2409.12064","url":null,"abstract":"Motivated by the Gottesman-Knill theorem, we present a detailed study of the\u0000quantum complexity of $p$-shell and $sd$-shell nuclei. Valence-space nuclear\u0000shell-model wavefunctions generated by the BIGSTICK code are mapped to qubit\u0000registers using the Jordan-Wigner mapping (12 qubits for the $p$-shell and 24\u0000qubits for the $sd$-shell), from which measures of the many-body entanglement\u0000($n$-tangles) and magic (non-stabilizerness) are determined. While exact\u0000evaluations of these measures are possible for nuclei with a modest number of\u0000active nucleons, Monte Carlo simulations are required for the more complex\u0000nuclei. The broadly-applicable Pauli-String $IZ$ exact (PSIZe-) MCMC technique\u0000is introduced to accelerate the evaluation of measures of magic in deformed\u0000nuclei (with hierarchical wavefunctions), by factors of $sim 8$ for some\u0000nuclei. Significant multi-nucleon entanglement is found in the $sd$-shell,\u0000dominated by proton-neutron configurations, along with significant measures of\u0000magic. This is evident not only for the deformed states, but also for nuclei on\u0000the path to instability via regions of shape coexistence and level inversion.\u0000These results indicate that quantum-computing resources will accelerate\u0000precision simulations of such nuclei and beyond.","PeriodicalId":501573,"journal":{"name":"arXiv - PHYS - Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263258","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}
We have shown that the relationship between the DIS structure functions is stable for a nuclear target with mass number A at $x{leq}10^{-3}$. Numerical results are provided for the specific nuclei 12C and 208Pb using the nuclear PDF parameterizations implemented in the HIJING2.0 model. These results fall whithin the EIC kinematic acceptance for heavy ion running. The ratio $R^{A}_{F_{L}}$ is calculated as the ratio $R^{A}_{F_{2}}$ in the HIJING2.0 model.
{"title":"Approximation method for the nuclear structure functions at small $x$","authors":"G. R. Boroun","doi":"arxiv-2409.11154","DOIUrl":"https://doi.org/arxiv-2409.11154","url":null,"abstract":"We have shown that the relationship between the DIS structure functions is\u0000stable for a nuclear target with mass number A at $x{leq}10^{-3}$. Numerical\u0000results are provided for the specific nuclei 12C and 208Pb using the nuclear\u0000PDF parameterizations implemented in the HIJING2.0 model. These results fall\u0000whithin the EIC kinematic acceptance for heavy ion running. The ratio\u0000$R^{A}_{F_{L}}$ is calculated as the ratio $R^{A}_{F_{2}}$ in the HIJING2.0\u0000model.","PeriodicalId":501573,"journal":{"name":"arXiv - PHYS - Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269936","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}
New liquid drop model with the isospin-square dependence of the volume and surface energy terms is applied to reproduce experimentally known masses of nuclei with number of protons and neutrons larger or equal to twenty. The ground-state microscopic energy corrections are taken into account. In spite of the fact that the model contains only six adjustable parameters, the quality of mass reproduction is good, and it is comparable with other contemporary mass models. Also, the fission barrier heights of actinide nuclei evaluated using the topographical theorem of Myers and Swiatecki are close to the data.
{"title":"Nuclear masses and fission barriers within the isospin-square liquid drop model","authors":"Krzysztof Pomorski","doi":"arxiv-2409.11019","DOIUrl":"https://doi.org/arxiv-2409.11019","url":null,"abstract":"New liquid drop model with the isospin-square dependence of the volume and\u0000surface energy terms is applied to reproduce experimentally known masses of\u0000nuclei with number of protons and neutrons larger or equal to twenty. The\u0000ground-state microscopic energy corrections are taken into account. In spite of\u0000the fact that the model contains only six adjustable parameters, the quality of\u0000mass reproduction is good, and it is comparable with other contemporary mass\u0000models. Also, the fission barrier heights of actinide nuclei evaluated using\u0000the topographical theorem of Myers and Swiatecki are close to the data.","PeriodicalId":501573,"journal":{"name":"arXiv - PHYS - Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263263","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}
We present a novel relaxation time approximation for kinetic theory with spin which takes into account the nonlocality of particle collisions. In particular, it models the property of the microscopic nonlocal collision term to vanish in global, but not in local equilibrium. We study the asymptotic distribution function obtained as the solution of the Boltzmann equation within the nonlocal relaxation time approximation in the limit of small gradients and short relaxation time. We show that the resulting polarization agrees with the one obtained from the Zubarev formalism for a certain value of a coefficient that determines the time scale on which orbital angular momentum is converted into spin. This coefficient can be identified with a parameter related to the pseudo gauge choice in the Zubarev formalism. Finally, we demonstrate how the nonlocal collision term generates polarization from vorticity by studying a nonrelativistic rotating cylinder both from kinetic and hydrodynamic approaches, which are shown to be equivalent in this example.
{"title":"Spin kinetic theory with a nonlocal relaxation time approximation","authors":"Nora Weickgenannt, Jean-Paul Blaizot","doi":"arxiv-2409.11045","DOIUrl":"https://doi.org/arxiv-2409.11045","url":null,"abstract":"We present a novel relaxation time approximation for kinetic theory with spin\u0000which takes into account the nonlocality of particle collisions. In particular,\u0000it models the property of the microscopic nonlocal collision term to vanish in\u0000global, but not in local equilibrium. We study the asymptotic distribution\u0000function obtained as the solution of the Boltzmann equation within the nonlocal\u0000relaxation time approximation in the limit of small gradients and short\u0000relaxation time. We show that the resulting polarization agrees with the one\u0000obtained from the Zubarev formalism for a certain value of a coefficient that\u0000determines the time scale on which orbital angular momentum is converted into\u0000spin. This coefficient can be identified with a parameter related to the pseudo\u0000gauge choice in the Zubarev formalism. Finally, we demonstrate how the nonlocal\u0000collision term generates polarization from vorticity by studying a\u0000nonrelativistic rotating cylinder both from kinetic and hydrodynamic\u0000approaches, which are shown to be equivalent in this example.","PeriodicalId":501573,"journal":{"name":"arXiv - PHYS - Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263266","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}
In the present work, we have predicted the half-lives for the $beta^{-}$ decay for higher forbidden unique transitions in the mass range of nuclei from A = 40-138. For these transitions, the experimental data for half-lives are not available except for a few cases. The calculations for half-lives are performed within the framework of the nuclear shell model (SM). We have used the effective interactions sdpf-mu, gxpf1a, gwbxg, G-matrix, snet, sn100pn, and jj56pnb to perform the SM calculations in different mass regions. A comprehensive discussion has been made between the SM-predicted half-lives and the scaled half-lives from proton-neutron quasiparticle random-phase approximation (pnQRPA). The results of the present study will be useful to plan new experiments to measure half-lives for these higher forbidden unique $beta^{-}$ transitions.
在本研究中，我们预测了原子核质量范围从A = 40-138的高禁唯一跃迁的$beta^{-}$衰变的半衰期。对于这些跃迁，除少数情况外，没有半衰期的实验数据。半衰期的计算是在核壳模型（SM）的框架内进行的。我们使用了有效的相互作用 sdpf-mu、gxpf1a、gwbxg、G-matrix、snet、sn100pn 和 jj56pnb 来进行不同质量区域的 SM 计算。对 SM 预测的半衰期和质子-中子准粒子随机相位逼近（pnQRPA）的缩放半衰期进行了全面讨论。本研究的结果将有助于规划新的实验，以测量这些更高的禁止的独特$beta^{-}$转变的半衰期。
{"title":"Higher forbidden unique $β^-$ decay transitions and shell-model interpretation","authors":"Archana Saxena, Praveen C. Srivastava","doi":"arxiv-2409.11244","DOIUrl":"https://doi.org/arxiv-2409.11244","url":null,"abstract":"In the present work, we have predicted the half-lives for the $beta^{-}$\u0000decay for higher forbidden unique transitions in the mass range of nuclei from\u0000A = 40-138. For these transitions, the experimental data for half-lives are not\u0000available except for a few cases. The calculations for half-lives are performed\u0000within the framework of the nuclear shell model (SM). We have used the\u0000effective interactions sdpf-mu, gxpf1a, gwbxg, G-matrix, snet, sn100pn, and\u0000jj56pnb to perform the SM calculations in different mass regions. A\u0000comprehensive discussion has been made between the SM-predicted half-lives and\u0000the scaled half-lives from proton-neutron quasiparticle random-phase\u0000approximation (pnQRPA). The results of the present study will be useful to plan\u0000new experiments to measure half-lives for these higher forbidden unique\u0000$beta^{-}$ transitions.","PeriodicalId":501573,"journal":{"name":"arXiv - PHYS - Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269881","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}
The recent discovery of gravitational waves (GWs) has opened a new avenue for investigating the equation of state (EOS) of dense matter in compact stars, which is an outstanding problem in astronomy and nuclear physics. In the future, next-generation (XG) GW detectors will be constructed, deemed to provide a large number of high-precision observations. We investigate the potential of constraining the EOS of quark stars (QSs) with high-precision measurements of mass $m$ and tidal deformability $Lambda$ from the XG GW observatories. We adopt the widely-used bag model for QSs, consisting of four microscopic parameters: the effective bag constant $B_{rm eff}$, the perturbative quantum chromodynamics correction parameter $a_4$, the strange quark mass $m_s$, and the pairing energy gap $Delta$. With the help of hierarchical Bayesian inference, for the first time we are able to infer the EOS of QSs combining multiple GW observations. Using the top 25 loudest GW events in our simulation, we find that, the constraints on $B_{rm eff}$ and $Delta$ are tightened by several times, while $a_4$ and $m_s$ are still poorly constrained. We also study a simplified 2-dimensional (2-d) EOS model which was recently proposed in literature. The 2-d model is found to exhibit significant parameter-estimation biases as more GW events are analyzed, while the predicted $m$-$Lambda$ relation remains consistent with the full model.
{"title":"Vetting quark-star models with gravitational waves in the hierarchical Bayesian framework","authors":"Ziming Wang, Yong Gao, Dicong Liang, Junjie Zhao, Lijing Shao","doi":"arxiv-2409.11103","DOIUrl":"https://doi.org/arxiv-2409.11103","url":null,"abstract":"The recent discovery of gravitational waves (GWs) has opened a new avenue for\u0000investigating the equation of state (EOS) of dense matter in compact stars,\u0000which is an outstanding problem in astronomy and nuclear physics. In the\u0000future, next-generation (XG) GW detectors will be constructed, deemed to\u0000provide a large number of high-precision observations. We investigate the\u0000potential of constraining the EOS of quark stars (QSs) with high-precision\u0000measurements of mass $m$ and tidal deformability $Lambda$ from the XG GW\u0000observatories. We adopt the widely-used bag model for QSs, consisting of four\u0000microscopic parameters: the effective bag constant $B_{rm eff}$, the\u0000perturbative quantum chromodynamics correction parameter $a_4$, the strange\u0000quark mass $m_s$, and the pairing energy gap $Delta$. With the help of\u0000hierarchical Bayesian inference, for the first time we are able to infer the\u0000EOS of QSs combining multiple GW observations. Using the top 25 loudest GW\u0000events in our simulation, we find that, the constraints on $B_{rm eff}$ and\u0000$Delta$ are tightened by several times, while $a_4$ and $m_s$ are still poorly\u0000constrained. We also study a simplified 2-dimensional (2-d) EOS model which was\u0000recently proposed in literature. The 2-d model is found to exhibit significant\u0000parameter-estimation biases as more GW events are analyzed, while the predicted\u0000$m$-$Lambda$ relation remains consistent with the full model.","PeriodicalId":501573,"journal":{"name":"arXiv - PHYS - Nuclear Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263265","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}
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