1
|
Huth S, Pang PTH, Tews I, Dietrich T, Le Fèvre A, Schwenk A, Trautmann W, Agarwal K, Bulla M, Coughlin MW, Van Den Broeck C. Constraining neutron-star matter with microscopic and macroscopic collisions. Nature 2022; 606:276-280. [PMID: 35676430 PMCID: PMC9177417 DOI: 10.1038/s41586-022-04750-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 04/11/2022] [Indexed: 11/16/2022]
Abstract
Interpreting high-energy, astrophysical phenomena, such as supernova explosions or neutron-star collisions, requires a robust understanding of matter at supranuclear densities. However, our knowledge about dense matter explored in the cores of neutron stars remains limited. Fortunately, dense matter is not probed only in astrophysical observations, but also in terrestrial heavy-ion collision experiments. Here we use Bayesian inference to combine data from astrophysical multi-messenger observations of neutron stars1-9 and from heavy-ion collisions of gold nuclei at relativistic energies10,11 with microscopic nuclear theory calculations12-17 to improve our understanding of dense matter. We find that the inclusion of heavy-ion collision data indicates an increase in the pressure in dense matter relative to previous analyses, shifting neutron-star radii towards larger values, consistent with recent observations by the Neutron Star Interior Composition Explorer mission5-8,18. Our findings show that constraints from heavy-ion collision experiments show a remarkable consistency with multi-messenger observations and provide complementary information on nuclear matter at intermediate densities. This work combines nuclear theory, nuclear experiment and astrophysical observations, and shows how joint analyses can shed light on the properties of neutron-rich supranuclear matter over the density range probed in neutron stars.
Collapse
Affiliation(s)
- Sabrina Huth
- Department of Physics, Technische Universität Darmstadt, Darmstadt, Germany.
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany.
| | - Peter T H Pang
- Nikhef, Amsterdam, The Netherlands.
- Institute for Gravitational and Subatomic Physics (GRASP), Utrecht University, Utrecht, The Netherlands.
| | - Ingo Tews
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Tim Dietrich
- Institut für Physik und Astronomie, Universität Potsdam, Potsdam, Germany
- Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam, Germany
| | - Arnaud Le Fèvre
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
| | - Achim Schwenk
- Department of Physics, Technische Universität Darmstadt, Darmstadt, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
- Max-Planck-Institut für Kernphysik, Heidelberg, Germany
| | | | - Kshitij Agarwal
- Physikalisches Institut, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Mattia Bulla
- The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, Stockholm, Sweden
| | - Michael W Coughlin
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Chris Van Den Broeck
- Nikhef, Amsterdam, The Netherlands
- Institute for Gravitational and Subatomic Physics (GRASP), Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
2
|
Quantifying the Effect of Initial Fluctuations on Isospin-Sensitive Observables from Heavy-Ion Collisions at Intermediate Energies. Symmetry (Basel) 2021. [DOI: 10.3390/sym13112172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Initial fluctuation is one of the ingredients that washes fingerprints of the nuclear symmetry energy on observables in heavy-ion collisions. By artificially using the same initial nuclei in all collision events, the effect of the initial fluctuation on isospin-sensitive observables, e.g., the yield ratio of free neutrons with respect to protons Nn/Np, 3H/3He yield ratio, the yield ratio between charged pions π−/π+, and the elliptic flow ratio or difference between free neutrons and protons v2n/v2p (v2n-v2p), are studied within the ultrarelativistic quantum molecular dynamics (UrQMD) model. In practice, Au + Au collisions with impact parameter b = 5 fm and beam energy Elab = 400 MeV/nucleon are calculated. It is found that the effect of the initialization on the yields of free protons and neutrons is small, while for the yield of pions, the directed and elliptic flows are found to be apparently influenced by the choice of initialization because of the strong memory effects. Regarding the isospin-sensitive observables, the effect of the initialization on Nn/Np and 3H/3He is negligible, while π−/π+ and v2n/v2p (v2n-v2p) display a distinct difference among different initializations. The fingerprints of symmetry energy on π−/π+ and v2n/v2p can be either enhanced or reduced when different initializations are utilized.
Collapse
|
3
|
Estee J, Lynch WG, Tsang CY, Barney J, Jhang G, Tsang MB, Wang R, Kaneko M, Lee JW, Isobe T, Kurata-Nishimura M, Murakami T, Ahn DS, Atar L, Aumann T, Baba H, Boretzky K, Brzychczyk J, Cerizza G, Chiga N, Fukuda N, Gasparic I, Hong B, Horvat A, Ieki K, Inabe N, Kim YJ, Kobayashi T, Kondo Y, Lasko P, Lee HS, Leifels Y, Łukasik J, Manfredi J, McIntosh AB, Morfouace P, Nakamura T, Nakatsuka N, Nishimura S, Otsu H, Pawłowski P, Pelczar K, Rossi D, Sakurai H, Santamaria C, Sato H, Scheit H, Shane R, Shimizu Y, Simon H, Snoch A, Sochocka A, Sumikama T, Suzuki H, Suzuki D, Takeda H, Tangwancharoen S, Toernqvist H, Togano Y, Xiao ZG, Yennello SJ, Zhang Y, Cozma MD. Probing the Symmetry Energy with the Spectral Pion Ratio. PHYSICAL REVIEW LETTERS 2021; 126:162701. [PMID: 33961456 DOI: 10.1103/physrevlett.126.162701] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/08/2021] [Accepted: 03/22/2021] [Indexed: 06/12/2023]
Abstract
Many neutron star properties, such as the proton fraction, reflect the symmetry energy contributions to the equation of state that dominate when neutron and proton densities differ strongly. To constrain these contributions at suprasaturation densities, we measure the spectra of charged pions produced by colliding rare isotope tin (Sn) beams with isotopically enriched Sn targets. Using ratios of the charged pion spectra measured at high transverse momenta, we deduce the slope of the symmetry energy to be 42<L<117 MeV. This value is slightly lower but consistent with the L values deduced from a recent measurement of the neutron skin thickness of ^{208}Pb.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - M D Cozma
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- IFIN-HH, Reactorului 30, 077125 Măgurele-Bucharest, Romania
| |
Collapse
|
4
|
Li H, Xu HJ, Zhou Y, Wang X, Zhao J, Chen LW, Wang F. Probing the Neutron Skin with Ultrarelativistic Isobaric Collisions. PHYSICAL REVIEW LETTERS 2020; 125:222301. [PMID: 33315427 DOI: 10.1103/physrevlett.125.222301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 10/15/2020] [Indexed: 06/12/2023]
Abstract
Particle production in ultrarelativistic heavy ion collisions depends on the details of the nucleon density distributions in the colliding nuclei. We demonstrate that the charged hadron multiplicity distributions in isobaric collisions at ultrarelativistic energies provide a novel approach to determine the poorly known neutron density distributions and thus the neutron skin thickness in finite nuclei, which can in turn put stringent constraints on the nuclear symmetry energy.
Collapse
Affiliation(s)
- Hanlin Li
- College of Science, Wuhan University of Science and Technology, Wuhan, Hubei 430065, China
| | - Hao-Jie Xu
- School of Science, Huzhou University, Huzhou, Zhejiang 313000, China
| | - Ying Zhou
- School of Physics and Astronomy and Shanghai Key Laboratory for Particle Physics and Cosmology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaobao Wang
- School of Science, Huzhou University, Huzhou, Zhejiang 313000, China
| | - Jie Zhao
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - Lie-Wen Chen
- School of Physics and Astronomy and Shanghai Key Laboratory for Particle Physics and Cosmology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Fuqiang Wang
- School of Science, Huzhou University, Huzhou, Zhejiang 313000, China
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| |
Collapse
|
5
|
Abstract
A brief review of some highlights and puzzles on strangeness production in heavy ion collisions is given. These include strangeness production and the nuclear equation of state; deeply subthreshold strangeness production; mean-field potentials on strange hadrons; phi meson in dense matter; anomalous strange hadron to pion ratios; density fluctuations on particle production; A hyperon polarization and the vorticity field, and exotic hadrons.
Collapse
|
6
|
|
7
|
|
8
|
Xiao Z, Li BA, Chen LW, Yong GC, Zhang M. Circumstantial evidence for a soft nuclear symmetry energy at suprasaturation densities. PHYSICAL REVIEW LETTERS 2009; 102:062502. [PMID: 19257581 DOI: 10.1103/physrevlett.102.062502] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Revised: 12/01/2008] [Indexed: 05/27/2023]
Abstract
Within an isospin- and momentum-dependent hadronic transport model, it is shown that the recent FOPI data on the pi;{-}/pi;{+} ratio in central heavy-ion collisions at SIS/GSI energies [Willy Reisdorf, Nucl. Phys. A 781, 459 (2007)10.1016/j.nuclphysa.2006.10.085] provide circumstantial evidence suggesting a rather soft nuclear symmetry energy E_{sym}(rho) at rho> or =2rho_{0} compared to the Akmal-Pandharipande-Ravenhall prediction. Some astrophysical implications and the need for further experimental confirmations are discussed.
Collapse
Affiliation(s)
- Zhigang Xiao
- Department of Physics, Tsinghua University, Beijing 100084, PR China
| | | | | | | | | |
Collapse
|
9
|
Famiano MA, Liu T, Lynch WG, Mocko M, Rogers AM, Tsang MB, Wallace MS, Charity RJ, Komarov S, Sarantites DG, Sobotka LG, Verde G. Neutron and proton transverse emission ratio measurements and the density dependence of the asymmetry term of the nuclear equation of state. PHYSICAL REVIEW LETTERS 2006; 97:052701. [PMID: 17026096 DOI: 10.1103/physrevlett.97.052701] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2006] [Indexed: 05/12/2023]
Abstract
Recent measurements of preequilibrium neutron and proton transverse emission from (112,124)Sn+(112,124)Sn reactions at 50 MeV/A have been completed at the National Superconducting Cyclotron Laboratory. Free nucleon transverse emission ratios are compared to those of A=3 mirror nuclei. Comparisons are made to Boltzmann-Uehling-Uhlenbeck (BUU) transport calculations and conclusions concerning the density dependence of the asymmetry term of the nuclear equation of state at subnuclear densities are made. Comparison to BUU model predictions indicate a density dependence of the asymmetry energy that is closer to a form in which the asymmetry energy increases as the square root of the density for the density region studied. A coalescent-invariant analysis is introduced as a means of reducing suggested difficulties with cluster emission in total nucleon emission.
Collapse
Affiliation(s)
- M A Famiano
- Physics Department, Western Michigan University, Kalamazoo, MI, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Le Fèvre A, Auger G, Begemann-Blaich ML, Bellaize N, Bittiger R, Bocage F, Borderie B, Bougault R, Bouriquet B, Charvet JL, Chbihi A, Dayras R, Durand D, Frankland JD, Galichet E, Gourio D, Guinet D, Hudan S, Immé G, Lautesse P, Lavaud F, Legrain R, Lopez O, Łukasik J, Lynen U, Müller WFJ, Nalpas L, Orth H, Plagnol E, Raciti G, Rosato E, Saija A, Schwarz C, Seidel W, Sfienti C, Tamain B, Trautmann W, Trzciński A, Turzó K, Vient E, Vigilante M, Volant C, Zwiegliński B, Botvina AS. Isotopic scaling and the symmetry energy in spectator fragmentation. PHYSICAL REVIEW LETTERS 2005; 94:162701. [PMID: 15904219 DOI: 10.1103/physrevlett.94.162701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2004] [Indexed: 05/02/2023]
Abstract
Isotopic effects in the fragmentation of excited target residues following collisions of 12C on (112,124)Sn at incident energies of 300 and 600 MeV per nucleon were studied with the INDRA 4pi detector. The measured yield ratios for light particles and fragments with atomic number Z < or = 5 obey the exponential law of isotopic scaling. The deduced scaling parameters decrease strongly with increasing centrality to values smaller than 50% of those obtained for the peripheral event groups. Symmetry-term coefficients, deduced from these data within the statistical description of isotopic scaling, are near gamma = 25 MeV for peripheral and gamma < 15 MeV for central collisions.
Collapse
Affiliation(s)
- A Le Fèvre
- Gesellschaft für Schwerionenforschung mbH, D-64291 Darmstadt, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Chen LW, Ko CM, Li BA. Determination of the stiffness of the nuclear symmetry energy from isospin diffusion. PHYSICAL REVIEW LETTERS 2005; 94:032701. [PMID: 15698257 DOI: 10.1103/physrevlett.94.032701] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2004] [Indexed: 05/24/2023]
Abstract
With an isospin- and momentum-dependent transport model, we find that the degree of isospin diffusion in heavy-ion collisions at intermediate energies is affected by both the stiffness of the nuclear symmetry energy and the momentum dependence of the nucleon potential. Using a momentum dependence derived from the Gogny effective interaction, recent experimental data from NSCL-MSU on isospin diffusion are shown to be consistent with a nuclear symmetry energy given by E(sym)(rho) approximately 31.6(rho/rho(0))(1.05) at subnormal densities. This leads to a significantly constrained value of about -550 MeV for the isospin-dependent part of the isobaric incompressibility of isospin asymmetric nuclear matter.
Collapse
Affiliation(s)
- Lie-Wen Chen
- Cyclotron Institute and Physics Department, Texas A&M University, College Station, Texas 77843-3366, USA
| | | | | |
Collapse
|
12
|
Tsang MB, Liu TX, Shi L, Danielewicz P, Gelbke CK, Liu XD, Lynch WG, Tan WP, Verde G, Wagner A, Xu HS, Friedman WA, Beaulieu L, Davin B, de Souza RT, Larochelle Y, Lefort T, Yanez R, Viola VE, Charity RJ, Sobotka LG. Isospin diffusion and the nuclear symmetry energy in heavy ion reactions. PHYSICAL REVIEW LETTERS 2004; 92:062701. [PMID: 14995234 DOI: 10.1103/physrevlett.92.062701] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2003] [Indexed: 05/24/2023]
Abstract
Using symmetric 112Sn+112Sn, 124Sn+124Sn collisions as references, we probe isospin diffusion in peripheral asymmetric 112Sn+124Sn, 124Sn+112Sn systems at an incident energy of E/A=50 MeV. Isoscaling analyses imply that the quasiprojectile and quasitarget in these collisions do not achieve isospin equilibrium, permitting an assessment of isospin transport rates. We find that comparisons between isospin sensitive experimental and theoretical observables, using suitably chosen scaled ratios, permit investigation of the density dependence of the asymmetry term of the nuclear equation of state.
Collapse
Affiliation(s)
- M B Tsang
- National Superconducting Cyclotron Laboratory and Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Chen LW, Greco V, Ko CM, Li BA. Effects of symmetry energy on two-nucleon correlation functions in heavy-ion collisions induced by neutron-rich nuclei. PHYSICAL REVIEW LETTERS 2003; 90:162701. [PMID: 12731973 DOI: 10.1103/physrevlett.90.162701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2002] [Indexed: 05/24/2023]
Abstract
Using an isospin-dependent transport model, we study the effects of nuclear symmetry energy on two-nucleon correlation functions in heavy-ion collisions induced by neutron-rich nuclei. We find that the density dependence of the nuclear symmetry energy affects significantly the nucleon emission times in these collisions, leading to larger values of two-nucleon correlation functions for a symmetry energy that has a stronger density dependence. Two-nucleon correlation functions are thus useful tools for extracting information about the nuclear symmetry energy from heavy-ion collisions.
Collapse
Affiliation(s)
- Lie-Wen Chen
- Cyclotron Institute and Physics Department, Texas A&M University, College Station, Texas 77843-3366, USA
| | | | | | | |
Collapse
|