A Modern View of the Equation of State in Nuclear and Neutron Star Matter
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Exploring Pulsars
High-energy astrophysics Explore the PUL SAR menagerie Astronomers are discovering many strange properties of compact stellar objects called pulsars. Here’s how they fit together. by Victoria M. Kaspi f you browse through an astronomy book published 25 years ago, you’d likely assume that astronomers understood extremely dense objects called neutron stars fairly well. The spectacular Crab Nebula’s central body has been a “poster child” for these objects for years. This specific neutron star is a pulsar that I rotates roughly 30 times per second, emitting regular appar- ent pulsations in Earth’s direction through a sort of “light- house” effect as the star rotates. While these textbook descriptions aren’t incorrect, research over roughly the past decade has shown that the picture they portray is fundamentally incomplete. Astrono- mers know that the simple scenario where neutron stars are all born “Crab-like” is not true. Experts in the field could not have imagined the variety of neutron stars they’ve recently observed. We’ve found that bizarre objects repre- sent a significant fraction of the neutron star population. With names like magnetars, anomalous X-ray pulsars, soft gamma repeaters, rotating radio transients, and compact Long the pulsar poster child, central objects, these bodies bear properties radically differ- the Crab Nebula’s central object is a fast-spinning neutron star ent from those of the Crab pulsar. Just how large a fraction that emits jets of radiation at its they represent is still hotly debated, but it’s at least 10 per- magnetic axis. Astronomers cent and maybe even the majority. -
Computing ATOMIC NUCLEI
UNIVERSAL NUCLEAR ENERGY DENSITY FUNCTIONAL Computing ATOMIC NUCLEI Petascale computing helps disentangle the nuclear puzzle. The goal of the Universal Nuclear Energy Density Functional (UNEDF) collaboration is to provide a comprehensive description of all nuclei and their reactions based on the most accurate knowledge of the nuclear interaction, the most reliable theoretical approaches, and the massive use of computer power. Science of Nuclei the Hamiltonian matrix. Coupled cluster (CC) Nuclei comprise 99.9% of all baryonic matter in techniques, which were formulated by nuclear sci- the Universe and are the fuel that burns in stars. entists in the 1950s, are essential techniques in The rather complex nature of the nuclear forces chemistry today and have recently been resurgent among protons and neutrons generates a broad in nuclear structure. Quantum Monte Carlo tech- range and diversity in the nuclear phenomena that niques dominate studies of phase transitions in can be observed. As shown during the last decade, spin systems and nuclei. These methods are used developing a comprehensive description of all to understand both the nuclear and electronic nuclei and their reactions requires theoretical and equations of state in condensed systems, and they experimental investigations of rare isotopes with are used to investigate the excitation spectra in unusual neutron-to-proton ratios. These nuclei nuclei, atoms, and molecules. are labeled exotic, or rare, because they are not When applied to systems with many active par- typically found on Earth. They are difficult to pro- ticles, ab initio and configuration interaction duce experimentally because they usually have methods present computational challenges as the extremely short lifetimes. -
1 Standard Model: Successes and Problems
Searching for new particles at the Large Hadron Collider James Hirschauer (Fermi National Accelerator Laboratory) Sambamurti Memorial Lecture : August 7, 2017 Our current theory of the most fundamental laws of physics, known as the standard model (SM), works very well to explain many aspects of nature. Most recently, the Higgs boson, predicted to exist in the late 1960s, was discovered by the CMS and ATLAS collaborations at the Large Hadron Collider at CERN in 2012 [1] marking the first observation of the full spectrum of predicted SM particles. Despite the great success of this theory, there are several aspects of nature for which the SM description is completely lacking or unsatisfactory, including the identity of the astronomically observed dark matter and the mass of newly discovered Higgs boson. These and other apparent limitations of the SM motivate the search for new phenomena beyond the SM either directly at the LHC or indirectly with lower energy, high precision experiments. In these proceedings, the successes and some of the shortcomings of the SM are described, followed by a description of the methods and status of the search for new phenomena at the LHC, with some focus on supersymmetry (SUSY) [2], a specific theory of physics beyond the standard model (BSM). 1 Standard model: successes and problems The standard model of particle physics describes the interactions of fundamental matter particles (quarks and leptons) via the fundamental forces (mediated by the force carrying particles: the photon, gluon, and weak bosons). The Higgs boson, also a fundamental SM particle, plays a central role in the mechanism that determines the masses of the photon and weak bosons, as well as the rest of the standard model particles. -
Chapter 22 Neutron Stars and Black Holes Units of Chapter 22 22.1 Neutron Stars 22.2 Pulsars 22.3 Xxneutron-Star Binaries: X-Ray Bursters
Chapter 22 Neutron Stars and Black Holes Units of Chapter 22 22.1 Neutron Stars 22.2 Pulsars 22.3 XXNeutron-Star Binaries: X-ray bursters [Look at the slides and the pictures in your book, but I won’t test you on this in detail, and we may skip altogether in class.] 22.4 Gamma-Ray Bursts 22.5 Black Holes 22.6 XXEinstein’s Theories of Relativity Special Relativity 22.7 Space Travel Near Black Holes 22.8 Observational Evidence for Black Holes Tests of General Relativity Gravity Waves: A New Window on the Universe Neutron Stars and Pulsars (sec. 22.1, 2 in textbook) 22.1 Neutron Stars According to models for stellar explosions: After a carbon detonation supernova (white dwarf in binary), little or nothing remains of the original star. After a core collapse supernova, part of the core may survive. It is very dense—as dense as an atomic nucleus—and is called a neutron star. [Recall that during core collapse the iron core (ashes of previous fusion reactions) is disintegrated into protons and neutrons, the protons combine with the surrounding electrons to make more neutrons, so the core becomes pure neutron matter. Because of this, core collapse can be halted if the core’s mass is between 1.4 (the Chandrasekhar limit) and about 3-4 solar masses, by neutron degeneracy.] What do you get if the core mass is less than 1.4 solar masses? Greater than 3-4 solar masses? 22.1 Neutron Stars Neutron stars, although they have 1–3 solar masses, are so dense that they are very small. -
7. Gamma and X-Ray Interactions in Matter
Photon interactions in matter Gamma- and X-Ray • Compton effect • Photoelectric effect Interactions in Matter • Pair production • Rayleigh (coherent) scattering Chapter 7 • Photonuclear interactions F.A. Attix, Introduction to Radiological Kinematics Physics and Radiation Dosimetry Interaction cross sections Energy-transfer cross sections Mass attenuation coefficients 1 2 Compton interaction A.H. Compton • Inelastic photon scattering by an electron • Arthur Holly Compton (September 10, 1892 – March 15, 1962) • Main assumption: the electron struck by the • Received Nobel prize in physics 1927 for incoming photon is unbound and stationary his discovery of the Compton effect – The largest contribution from binding is under • Was a key figure in the Manhattan Project, condition of high Z, low energy and creation of first nuclear reactor, which went critical in December 1942 – Under these conditions photoelectric effect is dominant Born and buried in • Consider two aspects: kinematics and cross Wooster, OH http://en.wikipedia.org/wiki/Arthur_Compton sections http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=22551 3 4 Compton interaction: Kinematics Compton interaction: Kinematics • An earlier theory of -ray scattering by Thomson, based on observations only at low energies, predicted that the scattered photon should always have the same energy as the incident one, regardless of h or • The failure of the Thomson theory to describe high-energy photon scattering necessitated the • Inelastic collision • After the collision the electron departs -
Sounds of a Supersolid A
NEWS & VIEWS RESEARCH hypothesis came from extensive population humans, implying possible mosquito exposure long-distance spread of insecticide-resistant time-series analysis from that earlier study5, to malaria parasites and the potential to spread mosquitoes, worsening an already dire situ- which showed beyond reasonable doubt that infection over great distances. ation, given the current spread of insecticide a mosquito vector species called Anopheles However, the authors failed to detect resistance in mosquito populations. This would coluzzii persists locally in the dry season in parasite infections in their aerially sampled be a matter of great concern because insecticides as-yet-undiscovered places. However, the malaria vectors, a result that they assert is to be are the best means of malaria control currently data were not consistent with this outcome for expected given the small sample size and the low available8. However, long-distance migration other malaria vectors in the study area — the parasite-infection rates typical of populations of could facilitate the desirable spread of mosqui- species Anopheles gambiae and Anopheles ara- malaria vectors. A problem with this argument toes for gene-based methods of malaria-vector biensis — leaving wind-powered long-distance is that the typical infection rates they mention control. One thing is certain, Huestis and col- migration as the only remaining possibility to are based on one specific mosquito body part leagues have permanently transformed our explain the data5. (salivary glands), rather than the unknown but understanding of African malaria vectors and Both modelling6 and genetic studies7 undoubtedly much higher infection rates that what it will take to conquer malaria. -
Constraining the Neutron Star Equation of State with Astrophysical Observables
CONSTRAINING THE NEUTRON STAR EQUATION OF STATE WITH ASTROPHYSICAL OBSERVABLES by Carolyn A. Raithel Copyright © Carolyn A. Raithel 2020 A Dissertation Submitted to the Faculty of the DEPARTMENT OF ASTRONOMY In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY WITH A MAJOR IN ASTRONOMY AND ASTROPHYSICS In the Graduate College THE UNIVERSITY OF ARIZONA 2020 3 ACKNOWLEDGEMENTS Looking back over the last five years, this dissertation would not have been possible with the support of many people. First and foremost, I would like to thank my advisor, Feryal Ozel,¨ from whom I have learned so much { about not only the science I want to do, but about the type of scientist I want to be. I am grateful as well for the support and mentorship of Dimitrios Psaltis and Vasileios Paschalidis { I have so enjoyed working with and learning from you both. To Joel Weisberg, my undergraduate research advisor who first got me started on this journey and who has continued to support me throughout, thank you. I believe a scientist is shaped by the mentors she has early in her career, and I am grateful to have had so many excellent ones. I am deeply thankful for my friends, near and far, who have supported me, encouraged me, and helped preserve my sanity over the last five years. To our astronomy crafting group Lia, Ekta, Samantha, and Allie; to my office mates David, Gabrielle, Tyler, Kaushik, and Michi; to Sarah, Marina, Tanner, Charlie, and Lina{ thank you. I will be forever grateful to my family for their continual support { espe- cially my parents, Don and Kathy, who instilled in me a love for learning from a very young age and who have encouraged me ever since. -
1 PROF. CHHANDA SAMANTA, Phd PAPERS in PEER REVIEWED INTERNATIONAL JOURNALS: 1. C. Samanta, T. A. Schmitt, “Binding, Bonding A
PROF. CHHANDA SAMANTA, PhD PAPERS IN PEER REVIEWED INTERNATIONAL JOURNALS: 1. C. Samanta, T. A. Schmitt, “Binding, bonding and charge symmetry breaking in Λ- hypernuclei”, arXiv:1710.08036v2 [nucl-th] (to be published) 2. T. A. Schmitt, C. Samanta, “A-dependence of -bond and charge symmetry energies”, EPJ Web Conf. 182, 03012 (2018) 3. Chhanda Samanta, Superheavy Nuclei to Hypernuclei: A Tribute to Walter Greiner, EPJ Web Conf. 182, 02107 (2018) 4. C. Samanta with X Qiu, L Tang, C Chen, et al., “Direct measurements of the lifetime of medium-heavy hypernuclei”, Nucl. Phys. A973, 116 (2018); arXiv:1212.1133 [nucl-ex] 5. C. Samanta with with S. Mukhopadhyay, D. Atta, K. Imam, D. N. Basu, “Static and rotating hadronic stars mixed with self-interacting fermionic Asymmetric Dark Matter”, The European Physical Journal C.77:440 (2017); arXiv:1612.07093v1 6. C. Samanta with R. Honda, M. Agnello, J. K. Ahn et al, “Missing-mass spectroscopy with 6 − + 6 the Li(π ,K )X reaction to search for ΛH”, Phys. Rev. C 96, 014005 (2017); arXiv:1703.00623v2 [nucl-ex] 7. C. Samanta with T. Gogami, C. Chen, D. Kawama et al., “Spectroscopy of the neutron-rich 7 hypernucleus He from electron scattering”, Phys. Rev. C94, 021302(R) (2016); arXiv:1606.09157 8. C. Samanta with T. Gogami, C. Chen, D. Kawama,et al., ”High Resolution Spectroscopic 10 Study of ΛBe”, Phys. Rev. C93, 034314(2016); arXiv:1511.04801v1[nucl-ex] 9. C. Samanta with L. Tang, C. Chen, T. Gogami et al., “The experiments with the High 12 Resolution Kaon Spectrometer at JLab Hall C and the new spectroscopy of ΛB hypernuclei, Phys. -
Current Status of Equation of State in Nuclear Matter and Neutron Stars
Open Issues in Understanding Core Collapse Supernovae June 22-24, 2004 Current Status of Equation of State in Nuclear Matter and Neutron Stars J.R.Stone1,2, J.C. Miller1,3 and W.G.Newton1 1 Oxford University, Oxford, UK 2Physics Division, ORNL, Oak Ridge, TN 3 SISSA, Trieste, Italy Outline 1. General properties of EOS in nuclear matter 2. Classification according to models of N-N interaction 3. Examples of EOS – sensitivity to the choice of N-N interaction 4. Consequences for supernova simulations 5. Constraints on EOS 6. High density nuclear matter (HDNM) 7. New developments Equation of State is derived from a known dependence of energy per particle of a system on particle number density: EA/(==En) or F/AF(n) I. E ( or Boltzman free energy F = E-TS for system at finite temperature) is constructed in a form of effective energy functional (Hamiltonian, Lagrangian, DFT/EFT functional or an empirical form) II. An equilibrium state of matter is found at each density n by minimization of E (n) or F (n) III. All other related quantities like e.g. pressure P, incompressibility K or entropy s are calculated as derivatives of E or F at equilibrium: 2 ∂E ()n ∂F ()n Pn()= n sn()=− | ∂n ∂T nY, p ∂∂P()nnEE() ∂2 ()n Kn()==9 18n +9n2 ∂∂nn∂n2 IV. Use as input for model simulations (Very) schematic sequence of equilibrium phases of nuclear matter as a function of density: <~2x10-4fm-3 ~2x10-4 fm-3 ~0.06 fm-3 Nuclei in Nuclei in Neutron electron gas + ‘Pasta phase’ Electron gas ~0.1 fm-3 0.3-0.5 fm-3 >0.5 fm-3 Nucleons + n,p,e,µ heavy baryons Quarks ??? -
Arxiv:1901.01410V3 [Astro-Ph.HE] 1 Feb 2021 Mental Information Is Available, and One Has to Rely Strongly on Theoretical Predictions for Nuclear Properties
Origin of the heaviest elements: The rapid neutron-capture process John J. Cowan∗ HLD Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, OK 73019, USA Christopher Snedeny Department of Astronomy, University of Texas, 2515 Speedway, Austin, TX 78712-1205, USA James E. Lawlerz Physics Department, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706-1390, USA Ani Aprahamianx and Michael Wiescher{ Department of Physics and Joint Institute for Nuclear Astrophysics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556, USA Karlheinz Langanke∗∗ GSI Helmholtzzentrum f¨urSchwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany and Institut f¨urKernphysik (Theoriezentrum), Fachbereich Physik, Technische Universit¨atDarmstadt, Schlossgartenstraße 2, 64298 Darmstadt, Germany Gabriel Mart´ınez-Pinedoyy GSI Helmholtzzentrum f¨urSchwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany; Institut f¨urKernphysik (Theoriezentrum), Fachbereich Physik, Technische Universit¨atDarmstadt, Schlossgartenstraße 2, 64298 Darmstadt, Germany; and Helmholtz Forschungsakademie Hessen f¨urFAIR, GSI Helmholtzzentrum f¨urSchwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany Friedrich-Karl Thielemannzz Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland and GSI Helmholtzzentrum f¨urSchwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany (Dated: February 2, 2021) The production of about half of the heavy elements found in nature is assigned to a spe- cific astrophysical nucleosynthesis process: the rapid neutron capture process (r-process). Although this idea has been postulated more than six decades ago, the full understand- ing faces two types of uncertainties/open questions: (a) The nucleosynthesis path in the nuclear chart runs close to the neutron-drip line, where presently only limited experi- arXiv:1901.01410v3 [astro-ph.HE] 1 Feb 2021 mental information is available, and one has to rely strongly on theoretical predictions for nuclear properties. -
A Short Walk Through the Physics of Neutron Stars
A short walk through the physics of neutron stars Isaac Vidaña, INFN Catania ASTRA: Advanced and open problems in low-energy nuclear and hadronic STRAngeness physics October 23rd-27th 2017, Trento (Italy) This short talk is just a brush-stroke on the physics of neutron stars. Three excellent monographs on this topic for interested readers are: Neutron stars are different things for different people ² For astronomers are very little stars “visible” as radio pulsars or sources of X- and γ-rays. ² For particle physicists are neutrino sources (when they born) and probably the only places in the Universe where deconfined quark matter may be abundant. ² For cosmologists are “almost” black holes. ² For nuclear physicists & the participants of this workshop are the biggest neutron-rich (hyper)nuclei of the Universe (A ~ 1056-1057, R ~ 10 km, M ~ 1-2 M ). ¤ But everybody agrees that … Neutron stars are a type of stellar compact remnant that can result from the gravitational collapse of a massive star (8 M¤< M < 25 M¤) during a Type II, Ib or Ic supernova event. 50 years of the discovery of the first radio pulsar ² radio pulsar at 81.5 MHz ² pulse period P=1.337 s Most NS are observed as pulsars. In 1967 Jocelyn Bell & Anthony Hewish discover the first radio pulsar, soon identified as a rotating neutron star (1974 Nobel Prize for Hewish but not for Jocelyn) Nowadays more than 2000 pulsars are known (~ 1900 Radio PSRs (141 in binary systems), ~ 40 X-ray PSRs & ~ 60 γ-ray PSRs) Observables § Period (P, dP/dt) § Masses § Luminosity § Temperature http://www.phys.ncku.edu.tw/~astrolab/mirrors/apod_e/ap090709.html -
Structure of Exotic Nuclei: a Theoretical Review
Structure of Exotic Nuclei: A Theoretical Review Shan-Gui Zhou∗ CAS Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000, China Synergetic Innovation Center for Quantum Effects and Application, Hunan Normal University, Changsha, 410081, China E-mail: [email protected] The study of exotic nuclei—nuclei with the ratio of neutron number N to proton number Z de- viating much from that of those found in nature—is at the forefront of nuclear physics research because it can not only reveal novel nuclear properties and thus enrich our knowledge of atomic nuclei, but also help us to understand the origin of chemical elements in the nucleosynthesis. With the development of radioactive ion beam facilities around the world, more and more unstable nu- clei become experimentally accessible. Many exotic nuclear phenomena have been observed or predicted in nuclei far from the β-stability line, such as neutron or proton halos, the shell evo- lution and changes of nuclear magic numbers, the island of inversion, soft-dipole excitations, clustering effects, new radioactivities, giant neutron halos, the shape decoupling between core and valence nucleons in deformed halo nuclei, etc. In this contribution, I will present a review of theoretical study of exotic nuclear structure. I will first introduce characteristic features and new physics connected with exotic nuclear phenomena: the weakly-bound feature, the large-spatial extension in halo nuclei, deformation effects in halo nuclei, the shell evolution, new radioactiv- ities and clustering effects.