Pub Date : 2024-09-03DOI: 10.1103/physrevc.110.034902
Yang He, Mengxue Zhang, Maowu Nie, Shanshan Cao, Li Yi
In relativistic heavy-ion collisions, jet quenching in quark-gluon plasma (QGP) has been extensively studied, revealing important insights into the properties of the color deconfined nuclear matter. Over the past decade, there has been a surge of interest in the exploration of QGP droplets in small collision systems, such as or collisions, driven by the observation of collective flow phenomena. However, the absence of jet quenching, a key QGP signature, in these systems poses a puzzle. Understanding how jet quenching evolves with system size is crucial for uncovering the underlying physics. In this study, we employ the linear Boltzmann transport (LBT) model to investigate jet modification in , and collisions at GeV. Our findings highlight the system size sensitivity exhibited by jet nuclear modification factor () and jet shape (), contrasting to the relatively weak responses of jet mass (), girth () and momentum dispersion () to system size variations. These results offer invaluable insights into the system size dependence of the QGP properties and await experimental validation at the Relativistic Heavy-Ion Collider.
{"title":"Exploring system-size dependence of jet modification in heavy-ion collisions","authors":"Yang He, Mengxue Zhang, Maowu Nie, Shanshan Cao, Li Yi","doi":"10.1103/physrevc.110.034902","DOIUrl":"https://doi.org/10.1103/physrevc.110.034902","url":null,"abstract":"In relativistic heavy-ion collisions, jet quenching in quark-gluon plasma (QGP) has been extensively studied, revealing important insights into the properties of the color deconfined nuclear matter. Over the past decade, there has been a surge of interest in the exploration of QGP droplets in small collision systems, such as <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mo>+</mo><mi>p</mi></mrow></math> or <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mo>+</mo><mi>A</mi></mrow></math> collisions, driven by the observation of collective flow phenomena. However, the absence of jet quenching, a key QGP signature, in these systems poses a puzzle. Understanding how jet quenching evolves with system size is crucial for uncovering the underlying physics. In this study, we employ the linear Boltzmann transport (LBT) model to investigate jet modification in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mmultiscripts><mi>Ru</mi><mprescripts></mprescripts><none></none><mn>96</mn></mmultiscripts><mo>+</mo><mmultiscripts><mi>Ru</mi><mprescripts></mprescripts><none></none><mn>96</mn></mmultiscripts></mrow><mo>,</mo><mo> </mo><mrow><mmultiscripts><mi>Zr</mi><mprescripts></mprescripts><none></none><mn>96</mn></mmultiscripts><mo>+</mo><mmultiscripts><mi>Zr</mi><mprescripts></mprescripts><none></none><mn>96</mn></mmultiscripts></mrow></math>, and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mmultiscripts><mi>Au</mi><mprescripts></mprescripts><none></none><mn>197</mn></mmultiscripts><mo>+</mo><mmultiscripts><mi>Au</mi><mprescripts></mprescripts><none></none><mn>197</mn></mmultiscripts></mrow></math> collisions at <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo>=</mo><mn>200</mn></mrow></math> GeV. Our findings highlight the system size sensitivity exhibited by jet nuclear modification factor (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>R</mi><mrow><mi>A</mi><mi>A</mi></mrow></msub></math>) and jet shape (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>ρ</mi></math>), contrasting to the relatively weak responses of jet mass (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>M</mi></math>), girth (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>g</mi></math>) and momentum dispersion (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>p</mi><mi mathvariant=\"normal\">T</mi></msub><mi>D</mi></mrow></math>) to system size variations. These results offer invaluable insights into the system size dependence of the QGP properties and await experimental validation at the Relativistic Heavy-Ion Collider.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1103/physrevc.110.034601
A. Pal, S. Santra, P. C. Rout, A. Kundu, D. Chattopadhyay, Ramandeep Gandhi, P. N. Patil, R. Tripathi, B. J. Roy, Y. Sawant, T. N. Nag, Abhijit Baishya, T. Santhosh, P. K. Rath, N. Deshmukh
Mass distributions of fission fragments arising from the slow quasifission (SQF) process, derived by comparing the measured data with theory for several reactions, show distinct features. Irrespective of fissioning systems, the peak corresponding to lighter fragments in the SQF mass distribution is found to be always at , whereas the peak position of the heavier fragments increases linearly with the mass of the dinuclear system. Further, the yield of quasifission events decreases with the increasing projectile energy. These observations within certain model dependence provide clear evidences of shell effect in slow quasifission, where the lighter fragments are possibly some closed-shell nuclei in the mass region (possibly or ). Further, the results from a model independent approach involving multi-Gaussian fit to the high energy data points reaffirm the above conclusion.
{"title":"Experimental evidence of shell effects in slow quasifission","authors":"A. Pal, S. Santra, P. C. Rout, A. Kundu, D. Chattopadhyay, Ramandeep Gandhi, P. N. Patil, R. Tripathi, B. J. Roy, Y. Sawant, T. N. Nag, Abhijit Baishya, T. Santhosh, P. K. Rath, N. Deshmukh","doi":"10.1103/physrevc.110.034601","DOIUrl":"https://doi.org/10.1103/physrevc.110.034601","url":null,"abstract":"Mass distributions of fission fragments arising from the slow quasifission (SQF) process, derived by comparing the measured data with theory for several reactions, show distinct features. Irrespective of fissioning systems, the peak corresponding to lighter fragments in the SQF mass distribution is found to be always at <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>A</mi><mo>≈</mo><mn>96</mn></mrow></math>, whereas the peak position of the heavier fragments increases linearly with the mass of the dinuclear system. Further, the yield of quasifission events decreases with the increasing projectile energy. These observations within certain model dependence provide clear evidences of shell effect in slow quasifission, where the lighter fragments are possibly some closed-shell nuclei in the mass region <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>A</mi><mo>≈</mo><mn>96</mn></mrow></math> (possibly <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Zr</mi><mprescripts></mprescripts><none></none><mn>96</mn></mmultiscripts></math> or <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Sr</mi><mprescripts></mprescripts><none></none><mn>94</mn></mmultiscripts></math>). Further, the results from a model independent approach involving multi-Gaussian fit to the high energy data points reaffirm the above conclusion.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1103/physrevc.110.024005
H. Witała, J. Golak, R. Skibiński
We propose a simplified approach to incorporate the long-range proton-proton () Coulomb force in three-nucleon (3N) scattering calculations, based on the exact formulation presented by Witała, Skibiński, Golak, and Glöckle [Eur. Phys. J. A41, 369 (2009) and Eur. Phys. J. A41, 385 (2009)]. It permits us to get elastic proton-deuteron () scattering and breakup observables relatively simply by performing standard Faddeev calculations as known for the neutron-deuteron () system. The basic ingredient in that approach is a three-dimensional screened Coulomb -matrix obtained by numerical solution of the three-dimensional Lippmann-Schwinger (LS) equation. Based on this -matrix, pure Coulomb transition terms contributing to elastic scattering and breakup are calculated without any need for partial-wave decomposition. For elastic scattering such a term removes the Rutherford amplitude for point deuteron proton-deuteron () scattering. For breakup it provides contributions which are important in some regions of the breakup phase space. We demonstrate numerically that the elastic observables can be determined directly from the resulting 3N amplitudes without any renormalization, simply by increasing the screening radius in order to reach the existing screening limit. However, for breakup the renormalization of the contributing on-shell amplitudes is required. We apply our approach in a wide energy range of the incoming proton for elastic scattering as well as for the breakup reaction.
我们根据维塔瓦、斯基宾斯基、戈拉克和格勒克尔提出的精确公式[欧洲物理学报 A 41, 369 (2009) 和欧洲物理学报 A 41, 385 (2009)]，提出了一种简化方法，将长程质子-质子（pp）库仑力纳入三核（3N）散射计算。它使我们能够相对简单地通过对中子-氘核（nd）系统进行已知的标准法迪夫计算来获得弹性质子-氘核（pd）散射和破裂观测值。这种方法的基本要素是通过数值求解三维李普曼-施温格（LS）方程获得的三维屏蔽pp库仑 t 矩阵。在此 t 矩阵的基础上，无需进行部分波分解，即可计算出导致弹性散射和破裂的纯库仑转换项。在弹性散射中，这个项消除了点氘核质子-氘核（pd）散射的卢瑟福振幅。对于破裂，它提供的贡献在破裂相空间的某些区域非常重要。我们用数值证明，只需增大屏蔽半径以达到现有的屏蔽极限，就可以直接从得到的 3N 振幅确定 pd 弹性观测值，而无需任何重正化。然而，对于 pd 破裂，需要对贡献的壳上振幅进行重正化。我们将我们的方法应用于 pd 弹性散射和 pd 分裂反应的入射质子的宽能量范围。
{"title":"Inclusion of the long-range proton-proton Coulomb force in the three-nucleon scattering Faddeev calculations","authors":"H. Witała, J. Golak, R. Skibiński","doi":"10.1103/physrevc.110.024005","DOIUrl":"https://doi.org/10.1103/physrevc.110.024005","url":null,"abstract":"We propose a simplified approach to incorporate the long-range proton-proton (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mi>p</mi></mrow></math>) Coulomb force in three-nucleon (3N) scattering calculations, based on the exact formulation presented by Witała, Skibiński, Golak, and Glöckle [<span>Eur. Phys. J. A</span> <b>41</b>, 369 (2009) and <span>Eur. Phys. J. A</span> <b>41</b>, 385 (2009)]. It permits us to get elastic proton-deuteron (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mi>d</mi></mrow></math>) scattering and breakup observables relatively simply by performing standard Faddeev calculations as known for the neutron-deuteron (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>n</mi><mi>d</mi></mrow></math>) system. The basic ingredient in that approach is a three-dimensional screened <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mi>p</mi></mrow></math> Coulomb <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>t</mi></math>-matrix obtained by numerical solution of the three-dimensional Lippmann-Schwinger (LS) equation. Based on this <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>t</mi></math>-matrix, pure Coulomb transition terms contributing to elastic scattering and breakup are calculated without any need for partial-wave decomposition. For elastic scattering such a term removes the Rutherford amplitude for point deuteron proton-deuteron (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mi>d</mi></mrow></math>) scattering. For breakup it provides contributions which are important in some regions of the breakup phase space. We demonstrate numerically that the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mi>d</mi></mrow></math> elastic observables can be determined directly from the resulting 3N amplitudes without any renormalization, simply by increasing the screening radius in order to reach the existing screening limit. However, for <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mi>d</mi></mrow></math> breakup the renormalization of the contributing on-shell amplitudes is required. We apply our approach in a wide energy range of the incoming proton for <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mi>d</mi></mrow></math> elastic scattering as well as for the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mi>d</mi></mrow></math> breakup reaction.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1103/physrevc.110.024323
A. Ravlić, T. Nikšić, Y. F. Niu, P. Ring, N. Paar
Collective nuclear excitations, like giant resonances, are sensitive to nuclear deformation, as evidenced by alterations in their excitation energies and transition strength distributions. A common theoretical framework to study these collective modes, the random-phase approximation (RPA), has to deal with large dimensions spanned by all possible particle-hole configurations satisfying certain symmetries. It is the aim of this work to establish a new theoretical framework to study the impact of deformation on spin-isospin excitations, that is able to provide fast and reliable solutions of the RPA equations. The nuclear ground state is determined with the axially deformed relativistic Hartree-Bogoliubov (RHB) model based on relativistic point-coupling energy density functionals (EDFs). To study the excitations in the charge-exchange channel, an axially deformed proton-neutron relativistic quasiparticle RPA (pnRQRPA) is developed in the linear response approach. After benchmarking the axially deformed pnRQRPA in the spherical limit, a study of spin-isospin excitations including Fermi, Gamow-Teller (GT), and spin-dipole (SD) is performed for selected -shell nuclei. For GT transitions, it is demonstrated that deformation leads to a considerable fragmentation of the strength function. A mechanism inducing the fragmentation is studied by decomposing the total strength to different projections of total angular momentum and constraining the nuclear shape to either spherical, prolate, or oblate. A similar fragmentation is also observed for SD transitions, although somewhat moderated by the complex structure of these transitions, while, as expected, the Fermi strength is almost shape independent. The axially deformed pnRQRPA introduced in this work open perspectives for the future studies of deformation effects on astrophysically relevant weak interaction processes, in particular beta decay and electron capture.
{"title":"Axially deformed relativistic quasiparticle random-phase approximation based on point-coupling interactions","authors":"A. Ravlić, T. Nikšić, Y. F. Niu, P. Ring, N. Paar","doi":"10.1103/physrevc.110.024323","DOIUrl":"https://doi.org/10.1103/physrevc.110.024323","url":null,"abstract":"Collective nuclear excitations, like giant resonances, are sensitive to nuclear deformation, as evidenced by alterations in their excitation energies and transition strength distributions. A common theoretical framework to study these collective modes, the random-phase approximation (RPA), has to deal with large dimensions spanned by all possible particle-hole configurations satisfying certain symmetries. It is the aim of this work to establish a new theoretical framework to study the impact of deformation on spin-isospin excitations, that is able to provide fast and reliable solutions of the RPA equations. The nuclear ground state is determined with the axially deformed relativistic Hartree-Bogoliubov (RHB) model based on relativistic point-coupling energy density functionals (EDFs). To study the excitations in the charge-exchange channel, an axially deformed proton-neutron relativistic quasiparticle RPA (pnRQRPA) is developed in the linear response approach. After benchmarking the axially deformed pnRQRPA in the spherical limit, a study of spin-isospin excitations including Fermi, Gamow-Teller (GT), and spin-dipole (SD) is performed for selected <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mi>f</mi></mrow></math>-shell nuclei. For GT transitions, it is demonstrated that deformation leads to a considerable fragmentation of the strength function. A mechanism inducing the fragmentation is studied by decomposing the total strength to different projections of total angular momentum <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>K</mi></math> and constraining the nuclear shape to either spherical, prolate, or oblate. A similar fragmentation is also observed for SD transitions, although somewhat moderated by the complex structure of these transitions, while, as expected, the Fermi strength is almost shape independent. The axially deformed pnRQRPA introduced in this work open perspectives for the future studies of deformation effects on astrophysically relevant weak interaction processes, in particular beta decay and electron capture.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-28DOI: 10.1103/physrevc.110.024910
Shuang Guo (郭爽), Han-Sheng Wang (王瀚生), Kai Zhou (周凯), Guo-Liang Ma (马国亮)
Collective flow has been found to be similar between small colliding systems ( and collisions) and large colliding systems (peripheral collisions) at the CERN Large Hadron Collider. In order to study the differences of collective flow between small and large colliding systems, we employ a point-cloud network to identify Pb collisions and peripheral Pb Pb collisions at TeV generated from a multiphase transport model. After removing the discrepancies in the pseudorapidity distribution and the spectra, we capture the discrepancy in collective flow. Although the verification accuracy of our PCN is limited due to similar event-by-event distributions of elliptic and triangular flow, we demonstrate that collective flow between Pb collisions and peripheral Pb Pb collisions becomes more distinct with increasing final hadron multiplicity and parton scattering cross section. This study not only highlights the potential of PCN techniques in advancing the understanding of collective flow in varying colliding systems, but more importantly lays the groundwork for the future PCN-related research.
{"title":"Machine learning study to identify collective flow in small and large colliding systems","authors":"Shuang Guo (郭爽), Han-Sheng Wang (王瀚生), Kai Zhou (周凯), Guo-Liang Ma (马国亮)","doi":"10.1103/physrevc.110.024910","DOIUrl":"https://doi.org/10.1103/physrevc.110.024910","url":null,"abstract":"Collective flow has been found to be similar between small colliding systems (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mo>+</mo><mi>p</mi></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi mathvariant=\"normal\">p</mi><mo>+</mo><mi mathvariant=\"normal\">A</mi></mrow></math> collisions) and large colliding systems (peripheral <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi mathvariant=\"normal\">A</mi><mo>+</mo><mi mathvariant=\"normal\">A</mi></mrow></math> collisions) at the CERN Large Hadron Collider. In order to study the differences of collective flow between small and large colliding systems, we employ a point-cloud network to identify <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mspace width=\"4pt\"></mspace><mo>+</mo></mrow></math> Pb collisions and peripheral Pb <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mo>+</mo></math> Pb collisions at <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msqrt><msub><mi>s</mi><mtext>NN</mtext></msub></msqrt><mo>=</mo><mn>5.02</mn></mrow></math> TeV generated from a multiphase transport model. After removing the discrepancies in the pseudorapidity distribution and the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>p</mi><mi mathvariant=\"normal\">T</mi></msub></math> spectra, we capture the discrepancy in collective flow. Although the verification accuracy of our PCN is limited due to similar event-by-event distributions of elliptic and triangular flow, we demonstrate that collective flow between <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>p</mi><mspace width=\"4pt\"></mspace><mo>+</mo></mrow></math> Pb collisions and peripheral Pb <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mo>+</mo></math> Pb collisions becomes more distinct with increasing final hadron multiplicity and parton scattering cross section. This study not only highlights the potential of PCN techniques in advancing the understanding of collective flow in varying colliding systems, but more importantly lays the groundwork for the future PCN-related research.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-28DOI: 10.1103/physrevc.110.024322
A. Sanchez, H. Iwasaki, A. Revel, B. A. Brown, J. Ash, D. Bazin, J. Chen, R. Elder, A. Gade, A. Goldkuhle, M. Grinder, D. Lempke, J. Li, B. Longfellow, C. Müller-Gatermann, J. Pereira, D. Rhodes, R. Salinas, D. Weisshaar
The <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>E</mi><mn>2</mn></mrow></math> transition matrix elements of isobaric multiplets are expected to follow a linear trend as a function of isospin projection. However, measurements of the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mn>2</mn><mo>+</mo></msup><mo>→</mo><msup><mn>0</mn><mo>+</mo></msup></mrow></math> transitions in the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>A</mi><mo>=</mo><mn>38</mn></mrow></math> triplet of Ca, K, and Ar show a deviation from this trend with an enhanced transition strength in <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>Ca</mi><mprescripts></mprescripts><none></none><mn>38</mn></mmultiscripts></math> with respect to its mirror <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>Ar</mi><mprescripts></mprescripts><none></none><mn>38</mn></mmultiscripts></math>. We have studied analogue <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>11</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo>→</mo><mn>7</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup></mrow><mo> </mo><mrow><mi>E</mi><mn>2</mn></mrow></math> transitions in <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>Ca</mi><mprescripts></mprescripts><none></none><mn>39</mn></mmultiscripts></math> and its mirror partner <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi mathvariant="normal">K</mi><mprescripts></mprescripts><none></none><mn>39</mn></mmultiscripts></math> to determine if this enhancement persists in neighboring Ca isotopes. Recoil-distance lifetime measurements of <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>Ca</mi><mprescripts></mprescripts><none></none><mn>39</mn></mmultiscripts></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi mathvariant="normal">K</mi><mprescripts></mprescripts><none></none><mn>39</mn></mmultiscripts></math> were performed utilizing a <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>Sc</mi><mprescripts></mprescripts><none></none><mn>42</mn></mmultiscripts></math> secondary beam, the TRIPLEX plunger, the GRETINA array, and the S800 spectrograph. Our data provide a lifetime measurement of the (<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>11</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup></mrow></math>) state in <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>Ca</mi><mprescripts></mprescripts><none></none><mn>39</mn></mmultiscripts></math> as well as an improved lifetime result for the (<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>9</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup></mrow></math>) state, while the <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi mathvariant="normal">K</mi><mprescripts></mprescripts><none></none><mn>39</mn></mmultiscripts></math> data are used to validate the present analysis. A comparison
{"title":"Proton and neutron contributions to the quadrupole transition strengths in Ca39 and K39 studied by lifetime measurements of mirror transitions","authors":"A. Sanchez, H. Iwasaki, A. Revel, B. A. Brown, J. Ash, D. Bazin, J. Chen, R. Elder, A. Gade, A. Goldkuhle, M. Grinder, D. Lempke, J. Li, B. Longfellow, C. Müller-Gatermann, J. Pereira, D. Rhodes, R. Salinas, D. Weisshaar","doi":"10.1103/physrevc.110.024322","DOIUrl":"https://doi.org/10.1103/physrevc.110.024322","url":null,"abstract":"The <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>E</mi><mn>2</mn></mrow></math> transition matrix elements of isobaric multiplets are expected to follow a linear trend as a function of isospin projection. However, measurements of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msup><mn>2</mn><mo>+</mo></msup><mo>→</mo><msup><mn>0</mn><mo>+</mo></msup></mrow></math> transitions in the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>A</mi><mo>=</mo><mn>38</mn></mrow></math> triplet of Ca, K, and Ar show a deviation from this trend with an enhanced transition strength in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Ca</mi><mprescripts></mprescripts><none></none><mn>38</mn></mmultiscripts></math> with respect to its mirror <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Ar</mi><mprescripts></mprescripts><none></none><mn>38</mn></mmultiscripts></math>. We have studied analogue <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>11</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo>→</mo><mn>7</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup></mrow><mo> </mo><mrow><mi>E</mi><mn>2</mn></mrow></math> transitions in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Ca</mi><mprescripts></mprescripts><none></none><mn>39</mn></mmultiscripts></math> and its mirror partner <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi mathvariant=\"normal\">K</mi><mprescripts></mprescripts><none></none><mn>39</mn></mmultiscripts></math> to determine if this enhancement persists in neighboring Ca isotopes. Recoil-distance lifetime measurements of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Ca</mi><mprescripts></mprescripts><none></none><mn>39</mn></mmultiscripts></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi mathvariant=\"normal\">K</mi><mprescripts></mprescripts><none></none><mn>39</mn></mmultiscripts></math> were performed utilizing a <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Sc</mi><mprescripts></mprescripts><none></none><mn>42</mn></mmultiscripts></math> secondary beam, the TRIPLEX plunger, the GRETINA array, and the S800 spectrograph. Our data provide a lifetime measurement of the (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>11</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup></mrow></math>) state in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Ca</mi><mprescripts></mprescripts><none></none><mn>39</mn></mmultiscripts></math> as well as an improved lifetime result for the (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>9</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup></mrow></math>) state, while the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi mathvariant=\"normal\">K</mi><mprescripts></mprescripts><none></none><mn>39</mn></mmultiscripts></math> data are used to validate the present analysis. A comparison ","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-28DOI: 10.1103/physrevc.110.024324
S. Chakraborty, S. Bhattacharyya, G. Mukherjee, C. Majumder
The structure of the negative parity bands, based on the orbital, in is revisited to search for the wobbling mode in this nucleus. Existing angular distribution/correlation and linear polarization results are indicative of a large admixture in the 365 keV interconnecting transition between yrast bands. This provides an indication of the existence of a wobbling mode in this nucleus. Theoretical calculations performed in this work using the quasiparticle plus triaxial rotor model have effectively replicated the available experimental results.
{"title":"Exploring the possibility of wobbling motion in Ba129","authors":"S. Chakraborty, S. Bhattacharyya, G. Mukherjee, C. Majumder","doi":"10.1103/physrevc.110.024324","DOIUrl":"https://doi.org/10.1103/physrevc.110.024324","url":null,"abstract":"The structure of the negative parity bands, based on the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>ν</mi><msub><mi>h</mi><mrow><mn>11</mn><mo>/</mo><mn>2</mn></mrow></msub></mrow></math> orbital, in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Ba</mi><mprescripts></mprescripts><none></none><mn>129</mn></mmultiscripts></math> is revisited to search for the wobbling mode in this nucleus. Existing angular distribution/correlation and linear polarization results are indicative of a large <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>E</mi><mn>2</mn></mrow></math> admixture in the 365 keV interconnecting <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi mathvariant=\"normal\">Δ</mi><mi>I</mi><mo>=</mo><mn>1</mn></mrow></math> <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>γ</mi></math> transition between yrast bands. This provides an indication of the existence of a wobbling mode in this nucleus. Theoretical calculations performed in this work using the quasiparticle plus triaxial rotor model have effectively replicated the available experimental results.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-28DOI: 10.1103/physrevc.110.025504
Krishnan Raghavan, Alessandro Lovato
Nuclear quantum many-body methods rely on integral transform techniques to infer properties of electroweak response functions from ground-state expectation values. Retrieving the energy dependence of these responses is highly nontrivial, especially for quantum Monte Carlo methods, as it requires inverting the Laplace transform, a notoriously ill-posed problem. In this work, we propose an artificial neural network architecture suitable for accurate response function reconstruction with precise estimation of the uncertainty of the inversion. We demonstrate the capabilities of this new architecture benchmarking it against maximum entropy and previously developed neural network methods designed for a similar task, paying particular attention to its robustness against increasing noise in the input Euclidean responses.
{"title":"Uncertainty-quantification-enabled inversion of nuclear responses","authors":"Krishnan Raghavan, Alessandro Lovato","doi":"10.1103/physrevc.110.025504","DOIUrl":"https://doi.org/10.1103/physrevc.110.025504","url":null,"abstract":"Nuclear quantum many-body methods rely on integral transform techniques to infer properties of electroweak response functions from ground-state expectation values. Retrieving the energy dependence of these responses is highly nontrivial, especially for quantum Monte Carlo methods, as it requires inverting the Laplace transform, a notoriously ill-posed problem. In this work, we propose an artificial neural network architecture suitable for accurate response function reconstruction with precise estimation of the uncertainty of the inversion. We demonstrate the capabilities of this new architecture benchmarking it against maximum entropy and previously developed neural network methods designed for a similar task, paying particular attention to its robustness against increasing noise in the input Euclidean responses.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-27DOI: 10.1103/physrevc.110.024614
A. Švarc, R. L. Workman
Single-energy partial-wave analysis has often been applied as a way to fit data with minimal model dependence. However, remaining unconstrained, partial waves at neighboring energies will vary discontinuously because the overall amplitude phase cannot be determined through single-channel measurements. This problem can be mitigated through the use of a constraining penalty function based on an associated energy-dependent fit. However, the weight given to this constraint results in a biased fit to the data. In this paper, for the first time, we explore a constraining function which does not influence the fit to data. The constraint comes from the overall phase found in multichannel fits which, in the present study, are the Bonn-Gatchina and Jülich-Bonn multichannel analyses. The data are well reproduced and weighting of the penalty function does not influence the result. The method is applied to photoproduction data and all observables can be maximally well reproduced. While the employed multichannel analyses display very different multipole amplitudes, we show that the major difference between two sets of multipoles can be related to the different overall phases.
{"title":"Single-channel and single-energy partial-wave analysis with continuity improved through minimal phase constraints","authors":"A. Švarc, R. L. Workman","doi":"10.1103/physrevc.110.024614","DOIUrl":"https://doi.org/10.1103/physrevc.110.024614","url":null,"abstract":"Single-energy partial-wave analysis has often been applied as a way to fit data with minimal model dependence. However, remaining unconstrained, partial waves at neighboring energies will vary discontinuously because the overall amplitude phase cannot be determined through single-channel measurements. This problem can be mitigated through the use of a constraining penalty function based on an associated energy-dependent fit. However, the weight given to this constraint results in a biased fit to the data. In this paper, for the first time, we explore a constraining function which does not influence the fit to data. The constraint comes from the overall phase found in multichannel fits which, in the present study, are the Bonn-Gatchina and Jülich-Bonn multichannel analyses. The data are well reproduced and weighting of the penalty function does not influence the result. The method is applied to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>K</mi><mi mathvariant=\"normal\">Λ</mi></mrow></math> photoproduction data and all observables can be maximally well reproduced. While the employed multichannel analyses display very different multipole amplitudes, we show that the major difference between two sets of multipoles can be related to the different overall phases.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-27DOI: 10.1103/physrevc.110.l021001
Ha S. Nguyen, Jared Vanasse
The Gamow-Teller and Fermi matrix elements, and , respectively, for tritium decay are calculated to next-to-leading order (NLO) in pionless effective field theory in the absence of Coulomb interactions and isospin violation giving the leading order predictions and . Using an experimentally determined value for the tritium decay GT matrix element, the two-body axial current low energy constant is fixed at NLO yielding at the renormalization scale of the physical pion mass, which agrees with predictions based on naive dimensional analysis. The impact of on proton-proton fusion is also discussed. Finally, the consequences of Wigner-SU(4) spin-isospin symmetry are considered for the Gamow-Teller matrix element.
{"title":"Tritium β decay and proton-proton fusion in pionless effective field theory","authors":"Ha S. Nguyen, Jared Vanasse","doi":"10.1103/physrevc.110.l021001","DOIUrl":"https://doi.org/10.1103/physrevc.110.l021001","url":null,"abstract":"The Gamow-Teller and Fermi matrix elements, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>〈</mo><mi mathvariant=\"bold\">GT</mi><mo>〉</mo></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>〈</mo><mi mathvariant=\"bold\">F</mi><mo>〉</mo></mrow></math>, respectively, for tritium <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>β</mi></math> decay are calculated to next-to-leading order (NLO) in pionless effective field theory in the absence of Coulomb interactions and isospin violation giving the leading order predictions <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mrow><mo>〈</mo><mi mathvariant=\"bold\">GT</mi><mo>〉</mo></mrow><mn>0</mn></msub><mo>=</mo><mn>0.9807</mn></mrow></math> and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mrow><mo>〈</mo><mi mathvariant=\"bold\">F</mi><mo>〉</mo></mrow><mn>0</mn></msub><mo>=</mo><mn>1</mn></mrow></math>. Using an experimentally determined value for the tritium <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>β</mi></math> decay GT matrix element, the two-body axial current low energy constant is fixed at NLO yielding <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>L</mi><mrow><mn>1</mn><mo>,</mo><mi>A</mi></mrow></msub><mo>=</mo><mn>6.01</mn><mo>±</mo><mn>2.08</mn><mspace width=\"4pt\"></mspace><msup><mrow><mi>fm</mi></mrow><mn>3</mn></msup></mrow></math> at the renormalization scale of the physical pion mass, which agrees with predictions based on naive dimensional analysis. The impact of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>L</mi><mrow><mn>1</mn><mo>,</mo><mi>A</mi></mrow></msub></math> on proton-proton fusion is also discussed. Finally, the consequences of Wigner-SU(4) spin-isospin symmetry are considered for the Gamow-Teller matrix element.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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