{"title":"N=50$同素异形体在$π g_{9/2}$壳中的反常资历断裂的 Ab initio 计算","authors":"Q. Yuan, B. S. Hu","doi":"arxiv-2409.10342","DOIUrl":null,"url":null,"abstract":"We performed \\textit{ab initio} valence-space in-medium similarity\nrenormalization group (VS-IMSRG) calculations based on chiral two-nucleon and\nthree-nucleon interactions to investigate the anomalous seniority breaking in\nthe neutron number $N=50$ isotones: $^{92}$Mo, $^{94}$Ru, $^{96}$Pd, and\n$^{98}$Cd. Our calculations well reproduced the measured low-lying spectra and\nelectromagnetic $E2$ transitions in these nuclei, supporting partial seniority\nconservation in the first $\\pi g_{9/2}$ shell. Recent experiments have revealed\nthat, compared to the symmetric patterns predicted under the conserved\nseniority symmetry, the $4^+_1\\to2^+_1$ $E2$ transition strength in $^{94}$Ru\nis significantly enhanced and that in $^{96}$Pd is suppressed. In contrast, the\n$6^+_1\\to 4^+_1$ and $8^+_1\\to6^+_1$ transitions exhibit the opposite trend. We\nfound that this anomalous asymmetry is sensitive to subtle seniority breaking\neffects, providing a stringent test for state-of-the-art nucleon-nucleon\ninteractions and nuclear models. We analyzed the anomalous asymmetry using\nVS-IMSRG calculations across various valence spaces. Our \\textit{ab initio}\nresults suggest that core excitations of both proton and neutron across the\n$Z=50$ shell are ascribed to the observed anomalous seniority breaking in the\n$N=50$ isotones.","PeriodicalId":501573,"journal":{"name":"arXiv - PHYS - Nuclear Theory","volume":"16 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Ab initio calculations of anomalous seniority breaking in the $π g_{9/2}$ shell for the $N=50$ isotones\",\"authors\":\"Q. Yuan, B. S. Hu\",\"doi\":\"arxiv-2409.10342\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"We performed \\\\textit{ab initio} valence-space in-medium similarity\\nrenormalization group (VS-IMSRG) calculations based on chiral two-nucleon and\\nthree-nucleon interactions to investigate the anomalous seniority breaking in\\nthe neutron number $N=50$ isotones: $^{92}$Mo, $^{94}$Ru, $^{96}$Pd, and\\n$^{98}$Cd. Our calculations well reproduced the measured low-lying spectra and\\nelectromagnetic $E2$ transitions in these nuclei, supporting partial seniority\\nconservation in the first $\\\\pi g_{9/2}$ shell. Recent experiments have revealed\\nthat, compared to the symmetric patterns predicted under the conserved\\nseniority symmetry, the $4^+_1\\\\to2^+_1$ $E2$ transition strength in $^{94}$Ru\\nis significantly enhanced and that in $^{96}$Pd is suppressed. In contrast, the\\n$6^+_1\\\\to 4^+_1$ and $8^+_1\\\\to6^+_1$ transitions exhibit the opposite trend. We\\nfound that this anomalous asymmetry is sensitive to subtle seniority breaking\\neffects, providing a stringent test for state-of-the-art nucleon-nucleon\\ninteractions and nuclear models. We analyzed the anomalous asymmetry using\\nVS-IMSRG calculations across various valence spaces. Our \\\\textit{ab initio}\\nresults suggest that core excitations of both proton and neutron across the\\n$Z=50$ shell are ascribed to the observed anomalous seniority breaking in the\\n$N=50$ isotones.\",\"PeriodicalId\":501573,\"journal\":{\"name\":\"arXiv - PHYS - Nuclear Theory\",\"volume\":\"16 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-09-16\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - PHYS - Nuclear Theory\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2409.10342\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Nuclear Theory","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2409.10342","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Ab initio calculations of anomalous seniority breaking in the $π g_{9/2}$ shell for the $N=50$ isotones
We performed \textit{ab initio} valence-space in-medium similarity
renormalization group (VS-IMSRG) calculations based on chiral two-nucleon and
three-nucleon interactions to investigate the anomalous seniority breaking in
the neutron number $N=50$ isotones: $^{92}$Mo, $^{94}$Ru, $^{96}$Pd, and
$^{98}$Cd. Our calculations well reproduced the measured low-lying spectra and
electromagnetic $E2$ transitions in these nuclei, supporting partial seniority
conservation in the first $\pi g_{9/2}$ shell. Recent experiments have revealed
that, compared to the symmetric patterns predicted under the conserved
seniority symmetry, the $4^+_1\to2^+_1$ $E2$ transition strength in $^{94}$Ru
is significantly enhanced and that in $^{96}$Pd is suppressed. In contrast, the
$6^+_1\to 4^+_1$ and $8^+_1\to6^+_1$ transitions exhibit the opposite trend. We
found that this anomalous asymmetry is sensitive to subtle seniority breaking
effects, providing a stringent test for state-of-the-art nucleon-nucleon
interactions and nuclear models. We analyzed the anomalous asymmetry using
VS-IMSRG calculations across various valence spaces. Our \textit{ab initio}
results suggest that core excitations of both proton and neutron across the
$Z=50$ shell are ascribed to the observed anomalous seniority breaking in the
$N=50$ isotones.