Pub Date : 2024-05-02DOI: 10.5506/APhysPolB.55.4-A4
A. Vuorinen
Understanding the properties and physical phase of the dense strongly interacting matter present in the cores of neutron stars or created in their binary mergers remains one of the most prominent open problems in nuclear astrophysics. While most microscopic analyses have historically relied on solvable phenomenological models of nuclear and quark matter, in recent years a model-independent approach utilizing only controlled ab-initio calculations and astrophysical observations has emerged as a viable alternative. In these lecture notes, I review recent progress in first-principles weak-coupling calculations within high-density quark matter, shedding light on its thermodynamic and transport properties. I cover the most important technical tools used in such calculations, introduce selected highlight results, and explain how this information can be used in phenomenological studies of neutron-star physics. The notes do not offer a self-consistent treatment of the topics covered, but rather aim at filling gaps in existing textbooks on thermal field theory and at connecting the dots in a story developed in several recent research articles, to which the interested reader is directed for further technical details.
{"title":"Particle-theory Input for Neutron-star Physics","authors":"A. Vuorinen","doi":"10.5506/APhysPolB.55.4-A4","DOIUrl":"https://doi.org/10.5506/APhysPolB.55.4-A4","url":null,"abstract":"Understanding the properties and physical phase of the dense strongly interacting matter present in the cores of neutron stars or created in their binary mergers remains one of the most prominent open problems in nuclear astrophysics. While most microscopic analyses have historically relied on solvable phenomenological models of nuclear and quark matter, in recent years a model-independent approach utilizing only controlled ab-initio calculations and astrophysical observations has emerged as a viable alternative. In these lecture notes, I review recent progress in first-principles weak-coupling calculations within high-density quark matter, shedding light on its thermodynamic and transport properties. I cover the most important technical tools used in such calculations, introduce selected highlight results, and explain how this information can be used in phenomenological studies of neutron-star physics. The notes do not offer a self-consistent treatment of the topics covered, but rather aim at filling gaps in existing textbooks on thermal field theory and at connecting the dots in a story developed in several recent research articles, to which the interested reader is directed for further technical details.","PeriodicalId":7060,"journal":{"name":"Acta Physica Polonica B","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141129888","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 : 2023-09-26DOI: 10.5506/aphyspolb.54.11-a4
Oskar Grocholski, P. Chankowski
We apply the thermal (imaginary time) perturbative expansion to the relevant effective field theory to compute characteristics of the phase transition to the ordered state which can occur at low temperatures in the gas of (nonrelativistic) spin 1/2 fermions interacting through a short-range spin independent repulsive binary interaction potential. We show how to obtain a systematic expansion of the system's free energy depending on the densities $n_+$ and $n_-$ of spin-up and spin-down fermions. In this paper we truncate this expansion at the second order and determine, by numerically minimizing the free energy, the equilibrium proportions of $n_+$ and $n_-$ (that is, the system's polarization) as functions of the temperature, the system's overall density $n = n_+ + n_-$ and the strength of the interaction.
{"title":"Perturbative Computation of Thermal Characteristics of the Stoner Phase Transition","authors":"Oskar Grocholski, P. Chankowski","doi":"10.5506/aphyspolb.54.11-a4","DOIUrl":"https://doi.org/10.5506/aphyspolb.54.11-a4","url":null,"abstract":"We apply the thermal (imaginary time) perturbative expansion to the relevant effective field theory to compute characteristics of the phase transition to the ordered state which can occur at low temperatures in the gas of (nonrelativistic) spin 1/2 fermions interacting through a short-range spin independent repulsive binary interaction potential. We show how to obtain a systematic expansion of the system's free energy depending on the densities $n_+$ and $n_-$ of spin-up and spin-down fermions. In this paper we truncate this expansion at the second order and determine, by numerically minimizing the free energy, the equilibrium proportions of $n_+$ and $n_-$ (that is, the system's polarization) as functions of the temperature, the system's overall density $n = n_+ + n_-$ and the strength of the interaction.","PeriodicalId":7060,"journal":{"name":"Acta Physica Polonica B","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139335855","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 : 2023-08-07DOI: 10.5506/aphyspolb.54.11-a2
E. Malec
We analyze the evolution of the mass density contrast in spherical perturbations of flat Friedman-Lemaitre-Robertson-Walker cosmologies. Both dark matter and dark energy are included. In the absence of dark energy the evolution equation coincides with that obtained by Bonnor within the ``Newtonian cosmology''.
{"title":"The Mass Density Contrast in Perturbed Friedman–Lemaître–Robertson–Walker Cosmologies","authors":"E. Malec","doi":"10.5506/aphyspolb.54.11-a2","DOIUrl":"https://doi.org/10.5506/aphyspolb.54.11-a2","url":null,"abstract":"We analyze the evolution of the mass density contrast in spherical perturbations of flat Friedman-Lemaitre-Robertson-Walker cosmologies. Both dark matter and dark energy are included. In the absence of dark energy the evolution equation coincides with that obtained by Bonnor within the ``Newtonian cosmology''.","PeriodicalId":7060,"journal":{"name":"Acta Physica Polonica B","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139351513","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 : 2023-08-07DOI: 10.5506/APhysPolB.54.11-A3
F. Ahmed
In this article, we present a stationary metric ansatz to describe a rotating traversable wormhole in the presence of the topological defect produced by a global monopole charge. This particular rotating space-time is referred to as the topologically charged rotating Schwarzschild-Klinkahmer wormhole. Our study involves the analysis of geodesic motion for test particles and photon rays in the context of this topologically charged rotating traversable wormhole. We aim to analyze the effects of global monopole charge and other parameters on the outcomes of this investigation. Additionally, we explore the matter-energy distribution within this rotating wormhole, considering it as a non-vacuum solution of Einstein's field equation. Notably, we demonstrate that the energy density of the matter content satisfies the criteria of the weak energy condition.
{"title":"Topologically Charged Rotating Wormhole","authors":"F. Ahmed","doi":"10.5506/APhysPolB.54.11-A3","DOIUrl":"https://doi.org/10.5506/APhysPolB.54.11-A3","url":null,"abstract":"In this article, we present a stationary metric ansatz to describe a rotating traversable wormhole in the presence of the topological defect produced by a global monopole charge. This particular rotating space-time is referred to as the topologically charged rotating Schwarzschild-Klinkahmer wormhole. Our study involves the analysis of geodesic motion for test particles and photon rays in the context of this topologically charged rotating traversable wormhole. We aim to analyze the effects of global monopole charge and other parameters on the outcomes of this investigation. Additionally, we explore the matter-energy distribution within this rotating wormhole, considering it as a non-vacuum solution of Einstein's field equation. Notably, we demonstrate that the energy density of the matter content satisfies the criteria of the weak energy condition.","PeriodicalId":7060,"journal":{"name":"Acta Physica Polonica B","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139351428","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 : 2023-07-26DOI: 10.5506/aphyspolb.54.7-a4
W. Broniowski, E. Arriola
Generalized transverse momentum distributions (GTMDs), the Wigner, and the Husimi distributions of quarks in the pion are evaluated in a chiral quark model at the one-loop-level. Analytic expressions are obtained for GTMDs, allowing for a qualitative discussion of their features, whereas the Wigner and the Husimi distribution are obtained with numerical integration of simple formulas. We explain the features of the Wigner distributions, in particular their non-positivity. In our model, the Husimi distributions, which are interpreted as coarse-grained Wigner distributions, are not mathematically positive-definite, but the magnitude of their negative values is tiny and occurs at large transverse momenta and impact parameters. Hence, as expected, coarse-graining leads to better behaved functions from the point of view of the probabilistic interpretation.
{"title":"Wigner and Husimi Partonic Distributions of the Pion in a Chiral Quark Model","authors":"W. Broniowski, E. Arriola","doi":"10.5506/aphyspolb.54.7-a4","DOIUrl":"https://doi.org/10.5506/aphyspolb.54.7-a4","url":null,"abstract":"Generalized transverse momentum distributions (GTMDs), the Wigner, and the Husimi distributions of quarks in the pion are evaluated in a chiral quark model at the one-loop-level. Analytic expressions are obtained for GTMDs, allowing for a qualitative discussion of their features, whereas the Wigner and the Husimi distribution are obtained with numerical integration of simple formulas. We explain the features of the Wigner distributions, in particular their non-positivity. In our model, the Husimi distributions, which are interpreted as coarse-grained Wigner distributions, are not mathematically positive-definite, but the magnitude of their negative values is tiny and occurs at large transverse momenta and impact parameters. Hence, as expected, coarse-graining leads to better behaved functions from the point of view of the probabilistic interpretation.","PeriodicalId":7060,"journal":{"name":"Acta Physica Polonica B","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44469337","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 : 2023-07-20DOI: 10.5506/aphyspolb.54.7-a1
Xue-Chao Feng, K. Wei
The mass and decay of the $sbar{s}$ member of the $1^{3}F_{4}$ meson nonet are investigated in the framework of the Regge phenomenology and the $^{3}P_{0}$ model. We propose, based on the results, that the assignment of the $sbar{s}$ member of the $1^{3}F_{4}$ meson nonet will require additional testing in the future. Our results also provide information for future studies of the $1^{3}F_{4}$ meson nonet.
{"title":"Mass and Decay of the (sbar {s}) Member of the 1(^{3}F_{4}) Meson Nonet","authors":"Xue-Chao Feng, K. Wei","doi":"10.5506/aphyspolb.54.7-a1","DOIUrl":"https://doi.org/10.5506/aphyspolb.54.7-a1","url":null,"abstract":"The mass and decay of the $sbar{s}$ member of the $1^{3}F_{4}$ meson nonet are investigated in the framework of the Regge phenomenology and the $^{3}P_{0}$ model. We propose, based on the results, that the assignment of the $sbar{s}$ member of the $1^{3}F_{4}$ meson nonet will require additional testing in the future. Our results also provide information for future studies of the $1^{3}F_{4}$ meson nonet.","PeriodicalId":7060,"journal":{"name":"Acta Physica Polonica B","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46522038","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 : 2023-07-11DOI: 10.5506/APhysPolB.54.4-A1
Kamal Kanta, B. Sahu, Jajati k. Nayak, R. Preethi, B. Sharma, Santosh Kumar
A phenomenological optical potential is used to study the elastic angular distributions for the system $^{19}F+^{208}Pb$ close to the Coulomb barrier. This potential is constructed by taking into account the flexible potential developed by Ginocchio. The fluctuations in the real and imaginary parts of the optical model potential follow the trends of the threshold anomaly. The set of optical potential parameters needed to analyze the fusion cross sections of the same system are obtained through analysis of the scattering cross sections. Theoretical fusion cross-sections and results from four different experimental groups well agree for a range of energies. Several Fluorine (F) isotopes are used as projectiles in this study of fusion cross-sections by slightly altering the radial parameter. It was found that the fusion process occurs unfettered in the $^{19}F +^{208}Pb$ system below the Coulomb barrier but is seriously hindered in the case of its isotopic projectiles.
{"title":"Simultaneous Study of Scattering and Fusion Hindrance Near Coulomb Barrier in F(+)Pb Systems","authors":"Kamal Kanta, B. Sahu, Jajati k. Nayak, R. Preethi, B. Sharma, Santosh Kumar","doi":"10.5506/APhysPolB.54.4-A1","DOIUrl":"https://doi.org/10.5506/APhysPolB.54.4-A1","url":null,"abstract":"A phenomenological optical potential is used to study the elastic angular distributions for the system $^{19}F+^{208}Pb$ close to the Coulomb barrier. This potential is constructed by taking into account the flexible potential developed by Ginocchio. The fluctuations in the real and imaginary parts of the optical model potential follow the trends of the threshold anomaly. The set of optical potential parameters needed to analyze the fusion cross sections of the same system are obtained through analysis of the scattering cross sections. Theoretical fusion cross-sections and results from four different experimental groups well agree for a range of energies. Several Fluorine (F) isotopes are used as projectiles in this study of fusion cross-sections by slightly altering the radial parameter. It was found that the fusion process occurs unfettered in the $^{19}F +^{208}Pb$ system below the Coulomb barrier but is seriously hindered in the case of its isotopic projectiles.","PeriodicalId":7060,"journal":{"name":"Acta Physica Polonica B","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41985163","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 : 2023-06-20DOI: 10.5506/APhysPolB.54.5-A4
Bora I¸sıldak, Alper Hayreter, Murat Hüdaverdi̇, F. Ilgin, S. Salva, Ebru ¸Sim¸sek, Sinan Güyer
There are a number of studies in the literature on search for Charge-Parity (CP) violating signals in top quark productions at the LHC. In most of these studies, ChromoMagnetic Dipole Moments (CMDM) and ChromoElectric Dipole Moments (CEDM) of top quarks is bounded either by deviations from the Standard Model (SM) cross sections or by T-odd asymmetries in di-muon channels. However, the required precision on these cross section values are far beyond from that of ATLAS or CMS experiments can reach. In this letter, the investigation of CEDM based asymmetries in the semileptonic top pair decays are presented as T-odd asymmetries in CMS experiment. Expected asymmetry values are determined at the detector level using MadGraph5, Pythia8 and Delphes softwares along with the discrimination of the signal and the background with Deep Neural Networks (DNN).
{"title":"Investigating the Violation of Charge-parity Symmetry Through Top-quark ChromoElectric Dipole Moments by Using Machine Learning Techniques","authors":"Bora I¸sıldak, Alper Hayreter, Murat Hüdaverdi̇, F. Ilgin, S. Salva, Ebru ¸Sim¸sek, Sinan Güyer","doi":"10.5506/APhysPolB.54.5-A4","DOIUrl":"https://doi.org/10.5506/APhysPolB.54.5-A4","url":null,"abstract":"There are a number of studies in the literature on search for Charge-Parity (CP) violating signals in top quark productions at the LHC. In most of these studies, ChromoMagnetic Dipole Moments (CMDM) and ChromoElectric Dipole Moments (CEDM) of top quarks is bounded either by deviations from the Standard Model (SM) cross sections or by T-odd asymmetries in di-muon channels. However, the required precision on these cross section values are far beyond from that of ATLAS or CMS experiments can reach. In this letter, the investigation of CEDM based asymmetries in the semileptonic top pair decays are presented as T-odd asymmetries in CMS experiment. Expected asymmetry values are determined at the detector level using MadGraph5, Pythia8 and Delphes softwares along with the discrimination of the signal and the background with Deep Neural Networks (DNN).","PeriodicalId":7060,"journal":{"name":"Acta Physica Polonica B","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48092141","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 : 2023-05-22DOI: 10.5506/APhysPolB.54.7-A3
F. Klinkhamer
We have recently discovered a smooth vacuum-wormhole solution of the first-order equations of general relativity. Here, we obtain the corresponding multiple-vacuum-wormhole solution. Assuming that our world is essentially Minkowski spacetime with a large number of these vacuum-defect wormholes inserted, there is then another flat spacetime with opposite spatial orientation, which may be called a"mirror"world. We briefly discuss some phenomenological aspects and point out that there will be no significant vacuum-Cherenkov radiation in our world, so that ultrahigh-energy cosmic rays do not constrain the typical size and separation of the wormhole mouths (different from the constraints obtained for a single Minkowski spacetime with similar defects). Other signatures from a"gas"of vacuum-defect wormholes are mentioned, including a possible time machine.
{"title":"Vacuum-Defect Wormholes and a Mirror World","authors":"F. Klinkhamer","doi":"10.5506/APhysPolB.54.7-A3","DOIUrl":"https://doi.org/10.5506/APhysPolB.54.7-A3","url":null,"abstract":"We have recently discovered a smooth vacuum-wormhole solution of the first-order equations of general relativity. Here, we obtain the corresponding multiple-vacuum-wormhole solution. Assuming that our world is essentially Minkowski spacetime with a large number of these vacuum-defect wormholes inserted, there is then another flat spacetime with opposite spatial orientation, which may be called a\"mirror\"world. We briefly discuss some phenomenological aspects and point out that there will be no significant vacuum-Cherenkov radiation in our world, so that ultrahigh-energy cosmic rays do not constrain the typical size and separation of the wormhole mouths (different from the constraints obtained for a single Minkowski spacetime with similar defects). Other signatures from a\"gas\"of vacuum-defect wormholes are mentioned, including a possible time machine.","PeriodicalId":7060,"journal":{"name":"Acta Physica Polonica B","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44913999","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 : 2023-02-02DOI: 10.5506/APhysPolB.54.1-A2
M. Sanctis
Lorentz scalar and mass interactions are studied in more detail in the framework of a reduced Dirac equation for heavy quark-antiquark mesons. A microscopic model for these interactions is proposed and analyzed. The charmonium mass spectrum is reproduced by means of two free parameters; a third parameter is fixed by means of a phenomenological hypothesis in accordance with the model.
{"title":"The Role of Scalar and Mass Interactions in a Relativistic Model of the Charmonium Spectrum","authors":"M. Sanctis","doi":"10.5506/APhysPolB.54.1-A2","DOIUrl":"https://doi.org/10.5506/APhysPolB.54.1-A2","url":null,"abstract":"Lorentz scalar and mass interactions are studied in more detail in the framework of a reduced Dirac equation for heavy quark-antiquark mesons. A microscopic model for these interactions is proposed and analyzed. The charmonium mass spectrum is reproduced by means of two free parameters; a third parameter is fixed by means of a phenomenological hypothesis in accordance with the model.","PeriodicalId":7060,"journal":{"name":"Acta Physica Polonica B","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42038701","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：