Pub Date : 2024-12-30DOI: 10.1016/j.nuclphysa.2024.123014
Stephan Narison
<div><div>We improve the determinations of the QCD condensates within the SVZ expansion in the axial-vector (A) channel using the ratio of Laplace sum rule (LSR) <span><math><msubsup><mrow><mi>R</mi></mrow><mrow><mn>10</mn></mrow><mrow><mi>A</mi></mrow></msubsup><mo>(</mo><mi>τ</mi><mo>)</mo></math></span> within stability criteria and <em>τ</em>-like higher moments <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>n</mi><mo>,</mo><mi>A</mi></mrow></msub></math></span> within stability for arbitrary <em>τ</em>-mass squared <span><math><msub><mrow><mi>s</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>. We find the same violation of the factorization by a factor 6 of the four-quark condensate as from <span><math><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo>→</mo></math></span> Hadrons data. One can notice a systematic alternate sign and no exponential growth of the size of these condensates. Then, we extract <span><math><msub><mrow><mi>α</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span> from the lowest <em>τ</em>-decay like moment. We obtain to order <span><math><msubsup><mrow><mi>α</mi></mrow><mrow><mi>s</mi></mrow><mrow><mn>4</mn></mrow></msubsup></math></span> the conservative value from the <span><math><msub><mrow><mi>s</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>-stability until <span><math><msubsup><mrow><mi>M</mi></mrow><mrow><mi>τ</mi></mrow><mrow><mn>2</mn></mrow></msubsup></math></span>: <span><math><msub><mrow><mi>α</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>(</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>τ</mi></mrow></msub><mo>)</mo><msub><mrow><mo>|</mo></mrow><mrow><mi>A</mi></mrow></msub><mo>=</mo><mn>0.3178</mn><mo>(</mo><mn>66</mn><mo>)</mo></math></span> (FO) and 0.3380 (44) (CI) leading to: <span><math><msub><mrow><mi>α</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>(</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>Z</mi></mrow></msub><mo>)</mo><msub><mrow><mo>|</mo></mrow><mrow><mi>A</mi></mrow></msub><mo>=</mo><mn>0.1182</mn><msub><mrow><mo>(</mo><mn>8</mn><mo>)</mo></mrow><mrow><mi>f</mi><mi>i</mi><mi>t</mi></mrow></msub><msub><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow><mrow><mi>e</mi><mi>v</mi><mi>o</mi><mi>l</mi><mo>.</mo></mrow></msub></math></span> (FO) and <span><math><mn>0.1206</mn><msub><mrow><mo>(</mo><mn>5</mn><mo>)</mo></mrow><mrow><mi>f</mi><mi>i</mi><mi>t</mi></mrow></msub><msub><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow><mrow><mi>e</mi><mi>v</mi><mi>o</mi><mi>l</mi><mo>.</mo></mrow></msub></math></span> (CI). We extend the analysis to the V–A channel and find: <span><math><msub><mrow><mi>α</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>(</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>τ</mi></mrow></msub><mo>)</mo><msub><mrow><mo>|</mo></mrow><mrow><mi>V</mi><mo>−</mo><mi>A</mi></mrow></msub><mo>=</mo><mn>0.3135</mn><mo>(</mo><mn>83</mn><mo>)</mo></math></span> (FO) and 0.3322 (81) (CI) leading to: <span><math><msub><mrow><mi>α
{"title":"QCD condensates and αs from τ-decay","authors":"Stephan Narison","doi":"10.1016/j.nuclphysa.2024.123014","DOIUrl":"10.1016/j.nuclphysa.2024.123014","url":null,"abstract":"<div><div>We improve the determinations of the QCD condensates within the SVZ expansion in the axial-vector (A) channel using the ratio of Laplace sum rule (LSR) <span><math><msubsup><mrow><mi>R</mi></mrow><mrow><mn>10</mn></mrow><mrow><mi>A</mi></mrow></msubsup><mo>(</mo><mi>τ</mi><mo>)</mo></math></span> within stability criteria and <em>τ</em>-like higher moments <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>n</mi><mo>,</mo><mi>A</mi></mrow></msub></math></span> within stability for arbitrary <em>τ</em>-mass squared <span><math><msub><mrow><mi>s</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>. We find the same violation of the factorization by a factor 6 of the four-quark condensate as from <span><math><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo>→</mo></math></span> Hadrons data. One can notice a systematic alternate sign and no exponential growth of the size of these condensates. Then, we extract <span><math><msub><mrow><mi>α</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span> from the lowest <em>τ</em>-decay like moment. We obtain to order <span><math><msubsup><mrow><mi>α</mi></mrow><mrow><mi>s</mi></mrow><mrow><mn>4</mn></mrow></msubsup></math></span> the conservative value from the <span><math><msub><mrow><mi>s</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>-stability until <span><math><msubsup><mrow><mi>M</mi></mrow><mrow><mi>τ</mi></mrow><mrow><mn>2</mn></mrow></msubsup></math></span>: <span><math><msub><mrow><mi>α</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>(</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>τ</mi></mrow></msub><mo>)</mo><msub><mrow><mo>|</mo></mrow><mrow><mi>A</mi></mrow></msub><mo>=</mo><mn>0.3178</mn><mo>(</mo><mn>66</mn><mo>)</mo></math></span> (FO) and 0.3380 (44) (CI) leading to: <span><math><msub><mrow><mi>α</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>(</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>Z</mi></mrow></msub><mo>)</mo><msub><mrow><mo>|</mo></mrow><mrow><mi>A</mi></mrow></msub><mo>=</mo><mn>0.1182</mn><msub><mrow><mo>(</mo><mn>8</mn><mo>)</mo></mrow><mrow><mi>f</mi><mi>i</mi><mi>t</mi></mrow></msub><msub><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow><mrow><mi>e</mi><mi>v</mi><mi>o</mi><mi>l</mi><mo>.</mo></mrow></msub></math></span> (FO) and <span><math><mn>0.1206</mn><msub><mrow><mo>(</mo><mn>5</mn><mo>)</mo></mrow><mrow><mi>f</mi><mi>i</mi><mi>t</mi></mrow></msub><msub><mrow><mo>(</mo><mn>3</mn><mo>)</mo></mrow><mrow><mi>e</mi><mi>v</mi><mi>o</mi><mi>l</mi><mo>.</mo></mrow></msub></math></span> (CI). We extend the analysis to the V–A channel and find: <span><math><msub><mrow><mi>α</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>(</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>τ</mi></mrow></msub><mo>)</mo><msub><mrow><mo>|</mo></mrow><mrow><mi>V</mi><mo>−</mo><mi>A</mi></mrow></msub><mo>=</mo><mn>0.3135</mn><mo>(</mo><mn>83</mn><mo>)</mo></math></span> (FO) and 0.3322 (81) (CI) leading to: <span><math><msub><mrow><mi>α","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1055 ","pages":"Article 123014"},"PeriodicalIF":1.7,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-12-19DOI: 10.1016/j.nuclphysa.2024.123010
Krishna Patel , Rahulbhai Mistry , Ajay Majethiya
In this article, we investigate the mass spectra and Regge trajectories of singly heavy baryons in the framework of the Relativistic Dirac formalism, incorporating a non-Coulombic linear potential. We have included spin-spin, spin-orbit and spin-tensor interactions to predict the masses of Λc, Σc, Ξc and Ωc baryons for both radial and orbital excitations. Our calculated masses are utilized to construct the Regge trajectories of Λc, Σc, Ξc and Ωc in both the and planes. Moreover, the strong decay widths and electromagnetic properties such as magnetic moments, transition magnetic moments and radiative decay widths are determined for the ground state of these baryons. We compare our results with other theoretical predictions and experimental observations. Our results closely align with both theoretical predictions and available experimental results.
{"title":"Relativistic insights into singly heavy baryons: Excitation, decays and magnetic moments","authors":"Krishna Patel , Rahulbhai Mistry , Ajay Majethiya","doi":"10.1016/j.nuclphysa.2024.123010","DOIUrl":"10.1016/j.nuclphysa.2024.123010","url":null,"abstract":"<div><div>In this article, we investigate the mass spectra and Regge trajectories of singly heavy baryons in the framework of the Relativistic Dirac formalism, incorporating a non-Coulombic linear potential. We have included spin-spin, spin-orbit and spin-tensor interactions to predict the masses of Λ<em>c</em>, Σ<em>c</em>, Ξ<em>c</em> and Ω<em>c</em> baryons for both radial and orbital excitations. Our calculated masses are utilized to construct the Regge trajectories of Λ<em>c</em>, Σ<em>c</em>, Ξ<em>c</em> and Ω<em>c</em> in both the <span><math><mo>(</mo><mi>J</mi><mo>,</mo><msup><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></math></span> and <span><math><mo>(</mo><msub><mrow><mi>n</mi></mrow><mrow><mi>r</mi></mrow></msub><mo>,</mo><msup><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></math></span> planes. Moreover, the strong decay widths and electromagnetic properties such as magnetic moments, transition magnetic moments and radiative decay widths are determined for the ground state of these baryons. We compare our results with other theoretical predictions and experimental observations. Our results closely align with both theoretical predictions and available experimental results.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1055 ","pages":"Article 123010"},"PeriodicalIF":1.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-12-18DOI: 10.1016/j.nuclphysa.2024.123008
Ferdinando Frascà , Andrea Beraudo , Michael Strickland
We exactly solve an RTA-Boltzmann equation that describes the dynamics of coupled massless quark and gluon fluids undergoing transversally homogeneous longitudinal boost-invariant expansion. We include a fugacity parameter that allows quarks to be out of chemical equilibrium and we account for the different collision rates of quarks and gluons, which are related by Casimir scaling. Based on these assumptions, we numerically determine the evolution of a large set of moments of the quark and gluon distribution functions and reconstruct their entire distribution functions. We find that both late and early-time attractors exist for all moments of the distribution functions containing more than one power of the squared longitudinal momentum. These attractors emerge long before the system reaches the regime where hydrodynamic approximations apply. In addition, we discuss how the shear viscous corrections and entropy density of the fluid mixture evolve and consider the properties of their respective attractors. Finally, the entropy production is also investigated for different initial values of momentum anisotropy and quark abundance.
{"title":"Far-from-equilibrium attractors in kinetic theory for a mixture of quark and gluon fluids","authors":"Ferdinando Frascà , Andrea Beraudo , Michael Strickland","doi":"10.1016/j.nuclphysa.2024.123008","DOIUrl":"10.1016/j.nuclphysa.2024.123008","url":null,"abstract":"<div><div>We exactly solve an RTA-Boltzmann equation that describes the dynamics of coupled massless quark and gluon fluids undergoing transversally homogeneous longitudinal boost-invariant expansion. We include a fugacity parameter that allows quarks to be out of chemical equilibrium and we account for the different collision rates of quarks and gluons, which are related by Casimir scaling. Based on these assumptions, we numerically determine the evolution of a large set of moments of the quark and gluon distribution functions and reconstruct their entire distribution functions. We find that both late and early-time attractors exist for all moments of the distribution functions containing more than one power of the squared longitudinal momentum. These attractors emerge long before the system reaches the regime where hydrodynamic approximations apply. In addition, we discuss how the shear viscous corrections and entropy density of the fluid mixture evolve and consider the properties of their respective attractors. Finally, the entropy production is also investigated for different initial values of momentum anisotropy and quark abundance.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1055 ","pages":"Article 123008"},"PeriodicalIF":1.7,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-16DOI: 10.1016/j.nuclphysa.2024.123009
S. Mallik
The phenomenon of nuclear liquid–gas phase transition is a topic of contemporary interest. In heavy-ion collisions, there is no direct way of accessing the thermodynamic variables like pressure, density, free energy, entropy etc., and unambiguous detection of phase transition becomes difficult. A peak in the first order derivative of total multiplicity with respect to temperature (commonly abbreviated as the multiplicity derivative) has been established as a new experimentally accessible signature of the nuclear liquid-gas phase transition. In this work, the effect of isospin asymmetry in the fragmenting system, as well as the nuclear equation of state, on the multiplicity derivative and specific heat at constant volume is investigated within the framework of the Canonical Thermodynamical Model (CTM) with a semi-microscopic cluster functional.
{"title":"Isospin effect on the liquid-gas phase transition for finite nuclei","authors":"S. Mallik","doi":"10.1016/j.nuclphysa.2024.123009","DOIUrl":"10.1016/j.nuclphysa.2024.123009","url":null,"abstract":"<div><div>The phenomenon of nuclear liquid–gas phase transition is a topic of contemporary interest. In heavy-ion collisions, there is no direct way of accessing the thermodynamic variables like pressure, density, free energy, entropy etc., and unambiguous detection of phase transition becomes difficult. A peak in the first order derivative of total multiplicity with respect to temperature (commonly abbreviated as the multiplicity derivative) has been established as a new experimentally accessible signature of the nuclear liquid-gas phase transition. In this work, the effect of isospin asymmetry in the fragmenting system, as well as the nuclear equation of state, on the multiplicity derivative and specific heat at constant volume is investigated within the framework of the Canonical Thermodynamical Model (CTM) with a semi-microscopic cluster functional.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1055 ","pages":"Article 123009"},"PeriodicalIF":1.7,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-12-12DOI: 10.1016/j.nuclphysa.2024.123007
Hossein Mehranfar, Mohammad Ali Jafarizadeh
This paper investigates the lightly bound model as a variant of the Skyrme model, which includes an additional fourth-degree potential term. The study explores its application to light nuclei, , using the rational map approximation. Even though the standard Skyrme model has demonstrated a great deal of usefulness in forecasting nuclear energies for specific nuclei, it continues to show inconsistencies with accurate experimental findings. Using this modified Skyrme model with an extra parameter, we achieve improved predictions of nuclear energies that better align with experimental data. By quantizing the model and fitting its parameters to the properties of the lithium-6 nucleus, we derive the static mass of Skyrmions that aligns more closely with the experimental values, along with the quantum energy contribution for both the ground and excited states of light nuclei, and the prediction of new states.
{"title":"Lightly bound Skyrmions and light nuclei","authors":"Hossein Mehranfar, Mohammad Ali Jafarizadeh","doi":"10.1016/j.nuclphysa.2024.123007","DOIUrl":"10.1016/j.nuclphysa.2024.123007","url":null,"abstract":"<div><div>This paper investigates the lightly bound model as a variant of the Skyrme model, which includes an additional fourth-degree potential term. The study explores its application to light nuclei, <span><math><mn>1</mn><mo>≤</mo><mi>B</mi><mo>≤</mo><mn>8</mn></math></span>, using the rational map approximation. Even though the standard Skyrme model has demonstrated a great deal of usefulness in forecasting nuclear energies for specific nuclei, it continues to show inconsistencies with accurate experimental findings. Using this modified Skyrme model with an extra parameter, we achieve improved predictions of nuclear energies that better align with experimental data. By quantizing the model and fitting its parameters to the properties of the lithium-6 nucleus, we derive the static mass of Skyrmions that aligns more closely with the experimental values, along with the quantum energy contribution for both the ground and excited states of light nuclei, and the prediction of new states.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1055 ","pages":"Article 123007"},"PeriodicalIF":1.7,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-12-10DOI: 10.1016/j.nuclphysa.2024.123006
I.A.M. Abdulmagead
By including the projectile neutron contribution, we developed a free parameter formula based on the Glauber model framework for nucleus-nucleus interaction to determine the total charge change cross section σcc. The formula successfully reproduced the experimental data of reactions 9Be + 12C, 16,17O + 12C, 27Al + 12C, 28Si + 12C, 40Ar + 12C, 56Fe + 12C, and 238U + 27Al. Consequently, our study ensures that the charge change cross sections depend on the projectile's neutrons, as well as its protons.
{"title":"New formula for charge change cross section of nucleus-nucleus interaction","authors":"I.A.M. Abdulmagead","doi":"10.1016/j.nuclphysa.2024.123006","DOIUrl":"10.1016/j.nuclphysa.2024.123006","url":null,"abstract":"<div><div>By including the projectile neutron contribution, we developed a free parameter formula based on the Glauber model framework for nucleus-nucleus interaction to determine the total charge change cross section σ<sub>cc</sub>. The formula successfully reproduced the experimental data of reactions <sup>9</sup>Be + <sup>12</sup>C, <sup>16,17</sup>O + <sup>12</sup>C, <sup>27</sup>Al + <sup>12</sup>C, <sup>28</sup>Si + <sup>12</sup>C, <sup>40</sup>Ar + <sup>12</sup>C, <sup>56</sup>Fe + <sup>12</sup>C, and <sup>238</sup>U + <sup>27</sup>Al. Consequently, our study ensures that the charge change cross sections depend on the projectile's neutrons, as well as its protons.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1055 ","pages":"Article 123006"},"PeriodicalIF":1.7,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-12-06DOI: 10.1016/j.nuclphysa.2024.123005
Dhanpat Sharma, Suneel Kumar
This research work delves into the contribution of different mass fragments in the generation of magnetic field during heavy ion collisions (HICs) in the intermediate energy regime. Isospin dependent quantum molecular dynamics (IQMD) framework has been employed as a primary tool for phase space along with minimum spanning tree with momentum cut (MSTP) algorithm for the clusterization process. In this study, temporal evolution of magnetic field due to various mass fragments and its correlation with the impact parameter have been visualized. Moreover, the influence of some significant observables, such as rapidity and transverse momentum on the production of magnetic field due to various mass fragments have been investigated to gain more insights.
{"title":"Probing the contribution of various mass fragments in the production of magnetic field during heavy ion collisions","authors":"Dhanpat Sharma, Suneel Kumar","doi":"10.1016/j.nuclphysa.2024.123005","DOIUrl":"10.1016/j.nuclphysa.2024.123005","url":null,"abstract":"<div><div>This research work delves into the contribution of different mass fragments in the generation of magnetic field during heavy ion collisions (HICs) in the intermediate energy regime. Isospin dependent quantum molecular dynamics (IQMD) framework has been employed as a primary tool for phase space along with minimum spanning tree with momentum cut (MSTP) algorithm for the clusterization process. In this study, temporal evolution of magnetic field due to various mass fragments and its correlation with the impact parameter have been visualized. Moreover, the influence of some significant observables, such as rapidity and transverse momentum on the production of magnetic field due to various mass fragments have been investigated to gain more insights.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1055 ","pages":"Article 123005"},"PeriodicalIF":1.7,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-12-03DOI: 10.1016/j.nuclphysa.2024.123004
Halim Büyükuslu
In this study, dispersive optical model (DOM) potential parameters were derived for the 197Au target nucleus up to an incident neutron energy of 200 MeV. The procedure involved fitting the theoretical total cross sections σtot with the experimental ones and thereby determining the valid free potential parameters at the lowest value of . The contribution of compound nuclei mechanism at low energies was also incorporated in the calculations. The theoretical results obtained using the derived potential were compared to the experimental data for both the angular differential cross-section and the elastic cross-section. While there was a good agreement with the experimental values for the total cross section, a satisfactory agreement was achieved for the angular cross section. The obtained potential is useful for describing the n+197Au scattering system and its outputs over an extensive energy spectrum.
{"title":"Dispersive optical-model potential parameters for neutron scattering on 197Au up to 200 MeV","authors":"Halim Büyükuslu","doi":"10.1016/j.nuclphysa.2024.123004","DOIUrl":"10.1016/j.nuclphysa.2024.123004","url":null,"abstract":"<div><div>In this study, dispersive optical model (DOM) potential parameters were derived for the <sup>197</sup>Au target nucleus up to an incident neutron energy of 200 MeV. The procedure involved fitting the theoretical total cross sections <em>σ<sub>tot</sub></em> with the experimental ones and thereby determining the valid free potential parameters at the lowest value of <span><math><mrow><msup><mrow><mi>χ</mi></mrow><mn>2</mn></msup><mo>/</mo><mi>M</mi></mrow></math></span>. The contribution of compound nuclei mechanism at low energies was also incorporated in the calculations. The theoretical results obtained using the derived potential were compared to the experimental data for both the angular differential cross-section and the elastic cross-section. While there was a good agreement with the experimental values for the total cross section, a satisfactory agreement was achieved for the angular cross section. The obtained potential is useful for describing the n+<sup>197</sup>Au scattering system and its outputs over an extensive energy spectrum.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1055 ","pages":"Article 123004"},"PeriodicalIF":1.7,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-12-02DOI: 10.1016/j.nuclphysa.2024.122994
Iqbal Mohi Ud Din , Sameer Ahmad Mir , Nasir Ahmad Rather , Saeed Uddin , Rameez Ahmad Parra
This work investigates the thermo-chemical freeze-out condition of the multi-component hot and dense hadron resonance gas (HRG) formed in the ultra-relativistic nucleus-nucleus collisions (URNNC). The van der Waals (VDW) type model used in the present analysis incorporates the repulsive as well as attractive interactions among the hadrons. The baryons (antibaryons) are treated as incompressible objects. Using this theoretical approach the values of the model freeze-out parameters of the system are extracted over a wide range of collision energy by analyzing experimental data on like-mass antibaryon to baryon ratios. The same set of parameters is found to explain the energy dependence of several other particle ratios quite satisfactorily. We find that the horn-like structures seen in the ratios of strange particles to pions as a function of the collision energy cannot be explained by the VDW-HRG model alone without considering the strangeness imbalance effect in the system. We have compared our freeze-out line with those obtained earlier. The correlation between the and ratios is also examined.
{"title":"Collision Energy Dependence of Particle Ratios and Freeze-out Parameters in Ultra Relativistic Nucleus Nucleus Collisions","authors":"Iqbal Mohi Ud Din , Sameer Ahmad Mir , Nasir Ahmad Rather , Saeed Uddin , Rameez Ahmad Parra","doi":"10.1016/j.nuclphysa.2024.122994","DOIUrl":"10.1016/j.nuclphysa.2024.122994","url":null,"abstract":"<div><div>This work investigates the thermo-chemical freeze-out condition of the multi-component hot and dense hadron resonance gas (HRG) formed in the ultra-relativistic nucleus-nucleus collisions (URNNC). The van der Waals (VDW) type model used in the present analysis incorporates the repulsive as well as attractive interactions among the hadrons. The baryons (antibaryons) are treated as incompressible objects. Using this theoretical approach the values of the model freeze-out parameters of the system are extracted over a wide range of collision energy by analyzing experimental data on like-mass antibaryon to baryon ratios. The same set of parameters is found to explain the energy dependence of several other particle ratios quite satisfactorily. We find that the horn-like structures seen in the ratios of strange particles to pions as a function of the collision energy cannot be explained by the VDW-HRG model alone without considering the strangeness imbalance effect in the system. We have compared our freeze-out line with those obtained earlier. The correlation between the <span><math><mover><mrow><mi>p</mi></mrow><mrow><mo>¯</mo></mrow></mover><mo>/</mo><mi>p</mi></math></span> and <span><math><msup><mrow><mi>K</mi></mrow><mrow><mo>−</mo></mrow></msup><mo>/</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup></math></span> ratios is also examined.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1055 ","pages":"Article 122994"},"PeriodicalIF":1.7,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-12-02DOI: 10.1016/j.nuclphysa.2024.122993
Vladimir A. Petrov, Nikolai P. Tkachenko
The question of possible existence of oscillations in the region of diffraction peak in pp - scattering at TeV is considered in detail. It is shown that, within available experimental data published by the TOTEM and ALFA/ATLAS, posing the question of searching for such a subtle effect looks premature.
{"title":"On supposed oscillations of differential cross sections in pp - scattering at s=13 TeV","authors":"Vladimir A. Petrov, Nikolai P. Tkachenko","doi":"10.1016/j.nuclphysa.2024.122993","DOIUrl":"10.1016/j.nuclphysa.2024.122993","url":null,"abstract":"<div><div>The question of possible existence of oscillations in the region of diffraction peak in <em>pp</em> - scattering at <span><math><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>13</mn></math></span> TeV is considered in detail. It is shown that, within available experimental data published by the TOTEM and ALFA/ATLAS, posing the question of searching for such a subtle effect looks premature.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1055 ","pages":"Article 122993"},"PeriodicalIF":1.7,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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