Article
Physics, Nuclear
Debraj Kundu, Vivek Baruah Thapa, Monika Sinha
Summary: Recent observations of massive pulsars suggest the presence of matter at very high densities beyond our normal understanding, which may lead to the appearance of exotic degrees of freedom in neutron star cores. Neutron stars are also characterized by high surface magnetic fields, up to approximately 10^16 G. This study examines the properties of dense matter with the possibility of heavier strange and nonstrange baryons, and kaons in the presence of a strong magnetic field. The findings suggest that a strong magnetic field can stiffen high-density matter, delaying the appearance of kaons and increasing the maximum attainable mass of neutron stars.
Article
Astronomy & Astrophysics
William G. Newton, Rebecca Preston, Lauren Balliet, Michael Ross
Summary: In this study, for the first time, Bayesian inference is used to investigate the properties of neutron star crust, incorporating neutron skin data and predictions of pure neutron matter. The results provide the most stringent constraints to date on the transition pressure, chemical potential, proton fractions, and properties of non-spherical nuclei layers in the crust.
Article
Astronomy & Astrophysics
Shriya Soma, Lingxiao Wang, Shuzhe Shi, Horst Stocker, Kai Zhou
Summary: This work presents a novel method that uses deep learning techniques to reconstruct the equation of state (EoS) of neutron stars. Experimental results on simulated data demonstrate the effectiveness of this method.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Vivek Baruah Thapa, Anil Kumar, Monika Sinha
Summary: The detection of gravitational waves from the merger of binary neutron star events and subsequent estimations of tidal deformability play a key role in constraining the behavior of dense matter. On the other hand, model parameters providing the highly dense matter response are bounded by nuclear saturation properties. This work analyzes coupling parametrizations from two classes based on covariant density functional models.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Physics, Fluids & Plasmas
Burkhard Militzer, Felipe Gonzalez-Cataldo, Shuai Zhang, Kevin P. Driver, Francois Soubiran
Summary: By combining simulation results of different elements and compounds, a first-principles equation of state database for matter at extreme conditions was established, providing valuable information on properties of mixtures at high density and temperature as well as predicting shock compression ratios.
Article
Astronomy & Astrophysics
J. M. Dong
Summary: This paper investigates the depletion effect of the Fermi surface and the quenched neutron triplet superfluidity on nuclear matter, exploring their impact on viscosity and core temperature of neutron stars. It was found that the core temperature of neutron stars in known low-mass X-ray binaries can be clearly divided into two groups, with some stars still being located in the unstable region. Additionally, the occurrence of the direct Urca process can reduce the inferred core temperature by about one order of magnitude, helping to alleviate the discrepancy between predictions and observations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
J. R. Stone, V Dexheimer, P. A. M. Guichon, A. W. Thomas, S. Typel
Summary: A new equation of state for cold and hot hyperonic matter has been developed in the context of the quark-meson-coupling model, yielding results compatible with existing nuclear physics constraints and astrophysical observations. The study explores the presence of hyperons in proto-neutron stars and neutron stars, as well as the nucleon-hyperon phase transition. Results show a correlation between hyperon presence and increasing temperature and density, with implications for understanding neutron star merger remnants.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Silvia Traversi, Prasanta Char, Giuseppe Pagliara, Alessandro Drago
Summary: This study explores the relationship between the existence of massive compact stars and their speed of sound, and finds that if these stars are strange quark stars, which are composed entirely of quarks, the speed of sound can be below the conformal limit. By using Bayesian analysis and astrophysical data, the study reveals that the posterior distribution of the squared speed of sound is peaked around 0.3, and the maximum mass of the most probable equation of state is approximately 2.13 times the mass of the Sun.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Physics, Nuclear
J. A. Rosero-Gil, G. Lugones
Summary: In this study, weak interaction processes within a combustion flame converting dense hadronic matter into quark matter in compact stars are analyzed using the Boltzmann equation. The analysis focuses on the evolution of quark matter, reaction rates, and neutrino emissivities without assumptions about neutrino degeneracy. Results reveal significant temperature increases within the flame, with rates varying based on initial conditions and densities.
Article
Astronomy & Astrophysics
Marie Cassing, Alexander Brisebois, Muhammad Azeem, Juergen Schaffner-Bielich
Summary: The generic properties of compact objects made of two different fluids of dark matter are studied. Compact objects with a core-shell structure and mixed dark matter components are investigated. The results show novel features in the mass-radius relations for combined dark matter compact objects, distinguishing them from compact objects with a single dark matter fluid and compact stars made of ordinary baryonic matter.
ASTROPHYSICAL JOURNAL
(2023)
Article
Physics, Nuclear
X-L Shang, J-M Dong, W. Zuo, P. Yin, U. Lombardo
Summary: An exact treatment of the operators Q/e(omega) and total momentum was used to solve the nuclear matter Bruecker-Bethe-Goldstone equation with two- and three-body forces. The results were compared with those obtained under angle-average and total momentum approximation, with the angle-average method providing a fairly accurate approximation while the total momentum approximation was found to be quite inaccurate.
Review
Multidisciplinary Sciences
Christoph Adam, Alberto Garcia Martin-Caro, Miguel Huidobro, Andrzej Wereszczynski
Summary: This article presents a general review of the crystalline solutions of the generalized Skyrme model and their applications in the study of cold nuclear matter at finite density and the Equation of State (EOS) of neutron stars. It is shown that the ground state of the Skyrme model on the three torus corresponds to configurations with different symmetries, and phase transitions between these configurations occur. The effects of nonzero finite isospin asymmetry and strange degrees of freedom are also explored, and an approximate EOS of dense matter is constructed by fitting the free parameters of the model to relevant nuclear observables close to saturation density.
Article
Physics, Multidisciplinary
Aaram J. Kim, Katharina Lenk, Jiajun Li, Philipp Werner, Martin Eckstein
Summary: We propose a diagrammatic Monte Carlo approach for quantum impurity models, which is a generalization of the strong-coupling expansion for fermionic impurity models. The algorithm is based on a self-consistently computed three-point vertex and a stochastically sampled four-point vertex and provides numerically exact results in a wide parameter regime. The performance of the algorithm is demonstrated with applications to a spin-boson model representing an emitter in a waveguide. The spatial distribution of the photon density around the emitter is also discussed.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Eemeli Annala, Tyler Gorda, Evangelia Katerini, Aleksi Kurkela, Joonas Nattila, Vasileios Paschalidis, Aleksi Vuorinen
Summary: Recent progress in neutron-star observations has the potential to greatly enhance our knowledge of strongly interacting matter under extreme conditions. By analyzing a large ensemble of randomly generated equations of state and corresponding stellar structures, this study aims to exploit current observational data and investigate the impact of future observations on neutron star properties. The study discusses the compatibility and impact of various hypotheses and measurements, and provides important constraints and insights on the equation of state, tidal deformabilities, and maximum mass of neutron stars.
Article
Physics, Multidisciplinary
Xueling Mu, Xia Zhou, Guansheng He
Summary: This paper investigates the impact of the saturation properties of nuclear matter on the mass of massive neutron stars and attempts to constrain the saturation properties of nuclear matter using SU(6) symmetry. The study concludes that it is difficult to obtain a stiff enough equation of state within the range of empirical values of saturation properties of nuclear matter to support the maximum mass of a neutron star up to 2.0 solar masses.
EUROPEAN PHYSICAL JOURNAL PLUS
(2021)
Review
Physics, Multidisciplinary
Kai Hebeler
Summary: Recent advances in nuclear structure theory through ab initio many-body calculations have expanded the accessible part of the nuclear landscape, allowing for new microscopic studies. While different many-body methods show remarkable agreement, comparison with experiment and understanding theoretical uncertainties remain important. Efforts are being made to improve nuclear interactions and operators, including the systematic derivation of contributions using chiral effective field theory. Ongoing work focuses on improving the treatment of 3N interactions in ab initio frameworks to further advance our understanding of atomic nuclei.
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS
(2021)
Article
Physics, Nuclear
Y. Kucuk, M. Karakoc, A. Vitturi
Summary: In this paper, the transition density to the 0(+) monopole resonant state was calculated using the collective macroscopic model to generate the inelastic scattering angular distribution of the alpha-alpha system. The macroscopic transition density and form factor show good agreement with results obtained from the microscopic ab-initio model calculations.
EUROPEAN PHYSICAL JOURNAL A
(2021)
Article
Physics, Multidisciplinary
Mohammad Al-Mamun, Andrew W. Steiner, Joonas Nattila, Jacob Lange, Richard O'Shaughnessy, Ingo Tews, Stefano Gandolfi, Craig Heinke, Sophia Han
Summary: The study performs joint Bayesian inference to verify neutron-star mass and radius constraints, finding consistency in electromagnetic data. The results suggest that gravitational-wave and electromagnetic observations provide a consistent picture of neutron-star structure.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Xiu-Lei Ren, Chun-Xuan Wang, Kai-Wen Li, Li-Sheng Geng, Jie Meng
Summary: The researchers formulated a relativistic chiral nucleon-nucleon interaction model that provides a good description of the phase shifts of J <= 1 partial waves. By using a specific form of regulator function to regularize the kernel potential, they successfully demonstrated that the resulting relativistic potential can accurately describe the unique features of the (1)S(0) channel.
CHINESE PHYSICS LETTERS
(2021)
Article
Physics, Multidisciplinary
Dean Lee, Scott Bogner, B. Alex Brown, Serdar Elhatisari, Evgeny Epelbaum, Heiko Hergert, Morten Hjorth-Jensen, Hermann Krebs, Ning Li, Bing-Nan Lu, Ulf-G Meissner
Summary: The passage discusses the approximate spin-isospin exchange symmetry in the strong interactions among nucleons, which is derived from quantum chromodynamics properties in the limit of many colors, N-c. This large-N-c symmetry is well hidden and only reveals itself when averaging over intrinsic spin orientations, requiring a momentum resolution scale close to an optimal scale known as Lambda(large-Nc) of around 500 MeV. The passage also derives a set of spin-isospin exchange sum rules and discusses implications for various applications in nuclear physics.
PHYSICAL REVIEW LETTERS
(2021)
Article
Astronomy & Astrophysics
Peter T. H. Pang, Ingo Tews, Michael W. Coughlin, Mattia Bulla, Chris van den Broeck, Tim Dietrich
Summary: Recent observations of neutron stars have provided a wealth of data to constrain the equation of state of nuclear matter. By revisiting previous constraints and incorporating new measurements, updated constraints on the interior of neutron stars have been derived.
ASTROPHYSICAL JOURNAL
(2021)
Review
Physics, Multidisciplinary
Ingo Tews, Diego Lonardoni, Stefano Gandolfi
Summary: Effective field theory interactions derived from chiral Lagrangians have significantly advanced microscopic studies of atomic nuclei and the nuclear-matter equation of state, providing an effective method for describing nuclear systems.
Article
Physics, Particles & Fields
Serdar Elhatisari, Timo A. Lahde, Dean Lee, Ulf-G Meissner, Thomas Vonk
Summary: We investigate the phase shifts of low-energy alpha-alpha scattering under variations of the fundamental parameters of the Standard Model. We find that positive shifts in the pion mass have a small effect on the S-wave phase shift, whereas lowering the pion mass adds some repulsion in the two-alpha system. Variations of the fine-structure constant have almost no effect on the low-energy alpha-alpha phase shifts. We further show that variations of these phase shifts with respect to the QCD theta-angle can be expressed in terms of the theta-dependent pion mass.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Multidisciplinary
Bing-Nan Lu, Ning Li, Serdar Elhatisari, Yuan-Zhuo Ma, Dean Lee, Ulf-G Meissner
Summary: We present a new method for computing perturbative corrections in projection QMC calculations and demonstrate it by computing nuclear ground state energies for a realistic chiral interaction. In contrast to the natural ordering, we find remarkably large second-order energy corrections.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Ingo Tews, Zohreh Davoudi, Andreas Ekstrom, Jason D. Holt, Kevin Becker, Raul Briceno, David J. Dean, William Detmold, Christian Drischler, Thomas Duguet, Evgeny Epelbaum, Ashot Gasparyan, Jambul Gegelia, Jeremy R. Green, Harald W. Griesshammer, Andrew D. Hanlon, Matthias Heinz, Heiko Hergert, Martin Hoferichter, Marc Illa, David Kekejian, Alejandro Kievsky, Sebastian Konig, Hermann Krebs, Kristina D. Launey, Dean Lee, Petr Navratil, Amy Nicholson, Assumpta Parreno, Daniel R. Phillips, Marek Ploszajczak, Xiu-Lei Ren, Thomas R. Richardson, Caroline Robin, Grigor H. Sargsyan, Martin J. Savage, Matthias R. Schindler, Phiala E. Shanahan, Roxanne P. Springer, Alexander Tichai, Ubirajara van Kolck, Michael L. Wagman, Andre Walker-Loud, Chieh-Jen Yang, Xilin Zhang
Summary: This is a collection of perspective pieces contributed by researchers in the field of low-energy nuclear physics, discussing the current status and challenges of theoretical research in this field, as well as new ideas and strategies in nuclear structure, reaction physics, effective field theory, lattice QCD, quantum information, and quantum computing.
Article
Multidisciplinary Sciences
Shihang Shen, Serdar Elhatisari, Timo A. Laehde, Dean Lee, Bing-Nan Lu, Ulf-G. Meissner
Summary: The carbon atom is the backbone of organic chemistry and has a complex nucleus in its predominant isotope, C-12. In this study, a model-independent density map of the nuclear states of C-12 is provided using nuclear lattice effective field theory. The well-known Hoyle state is found to have a bent-arm or obtuse triangular arrangement of alpha clusters. All low-lying nuclear states of C-12 are identified as having an intrinsic shape composed of three alpha clusters forming either an equilateral triangle or an obtuse triangle.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Nuclear
Fabian Hildenbrand, Serdar Elhatisari, Timo A. Laehde, Dean Lee, Ulf-G Meissner
Summary: We develop the impurity lattice Monte Carlo formalism for the case of two distinguishable impurities in a bath of polarized fermions. The method is applied to non-relativistic three-dimensional systems, studying the formation and disintegration of bound states in the presence of attractive impurity-majority interactions and varying impurity-impurity interaction strength.
EUROPEAN PHYSICAL JOURNAL A
(2022)
Article
Astronomy & Astrophysics
Nina Kunert, Peter T. H. Pang, Ingo Tews, Michael W. Coughlin, Tim Dietrich
Summary: With the increasing sensitivity of gravitational-wave detectors, the combined analysis of multiple binary neutron-star systems through gravitational waves offers the possibility to accurately constrain the neutron-star radius and the equation of state of dense nuclear matter. However, it is crucial to address systematic biases caused by uncertainties in the gravitational-wave models when combining information from multiple detections.
Article
Physics, Nuclear
Reed Essick, Philippe Landry, Achim Schwenk, Ingo Tews
Summary: The study found that observations from heavy pulsar masses, LIGO/Virgo, and NICER prefer smaller values of the neutron skin and L, as well as negative symmetry incompressibilities. Combining astrophysical data with chiral effective field theory (chi EFT) and PREX-II constraints yields specific values for S-0, L, and R-skin(208Pb). There is good agreement between chi EFT, astrophysical observations, and other nuclear experiments.
Article
Astronomy & Astrophysics
Ingo Tews, Peter T. H. Pang, Tim Dietrich, Michael W. Coughlin, Sarah Antier, Mattia Bulla, Jack Heinzel, Lina Issa
Summary: The observation suggests that the compact object has a mass of 2.50-2.67M99.9%, and even with relaxed constraints on the maximum mass of neutron stars, the probability of a binary black hole origin remains around 81%. Analysis of the allowed region in the mass-radius diagram for neutron stars indicates that the scenario with a neutron star as the secondary object would require a rather stiff equation of state.
ASTROPHYSICAL JOURNAL LETTERS
(2021)