DOCSLIB.ORG

LOW ENERGY PIONS in NUCLEAR PHYSICS Mannque Rho

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
LOW ENERGY PIONS in NUCLEAR PHYSICS Mannque Rho LOW ENERGY PIONS IN NUCLEAR PHYSICS Mannque Rho To cite this version: Mannque Rho. LOW ENERGY PIONS IN NUCLEAR PHYSICS. Journal de Physique Colloques, 1972, 33 (C5), pp.C5-155-C5-169. 10.1051/jphyscol:1972512. jpa-00215114 HAL Id: jpa-00215114 https://hal.archives-ouvertes.fr/jpa-00215114 Submitted on 1 Jan 1972 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. JOURNAL DE PHYSIQUE Calloque C5, supplement au no 8-9, Tome 33, ~oOt-Septembre 1972, page C5-155 LOW ENERGY PIONS IN NUCLFAR PHYSICS Mannque RiiO Service de Physique Theorique, CEN-Saclay - France Rdsumd - On discute d'une faqon unifide 1es effets despiuns virtuels en physique nu- c- et l'rnteraction dwpions r&ls avec les noyaux & basse dnergie en termes du th&oreme de pions mous. Lcs sujets trait& de cette manihre sont les sufvants : les phd- nomisnes de courant d'echange, les rcgles de some reliant ceux-ci aux quantitds mesurdescims lesexperiences a haute hergie, la production, l'absorption et la diffusion despions par 1.2s noyaux prhs du seuil, et Itextraction & partir des donndes d'atomes X-m8siques des il~formationssur la symktrie chirakbrisec dans l'inter~ctionforte. Abstract - The effect of virtual pions in low-energy properties of nuclei and the inter- action wxth nuclei of low-energy real pions are discussed in terms of the information extracted from the exact soft-pion limit. The subjects treated in this way are the exchange current phenomena, the sum rules connecting these to quantities measurable in high energy sxperiments, the production, absorption and scattering of pions near threshold, and the extraction from x-mcsic data of an Information on the rhiral symmetry breaking in strong rnteract ion Hamiltonfan. I - IE*"TROWCTION - The pion was predicted in 1935 on the longest range part of it. Thus the pion by Yukawa and discovered in the laboratory in 1947. plays an essential role here just as the small mass It fs now well-known that just as the photon media- of pion plays a crucial role in the theories of tes the atomic and molecular forces, the pion me- elementary particle physics. The aim of this talk diates the nuclear force, responsible mainly for is to discuss the relevance of pions to nuclear the long range part. The pion mediating such force physics in as unified manner as it is possible to- is virtual just as the photon mediating the atomic day. Let me first explain what I mean by a unified and molecular forces is. However a pion can also be ma.-iner. The pion is a pseudoscalar object, spin produced if sufficient energy is given or it can be zero and parity-1 and may be described besides its absorbed by releasing energy. We say that the pion quantum numbers by the mmentum four vector -* invalved in this Latter process is real, i.e., on qk= (q i ) . A real plon satisfies the mass-shell q0 its mass shell.Just as the real photon has no mass, condition the pion 1s almost massless, in any case the smal- q2 = q2-q2 :-m2 . (1) lest among the known hadrons. This fact is quite X imf)ortant as we shall see later. The non-zero mass, However a virtual pion need not satisfy this. In however small it may br, turns out to raise many fact one defines a virtual pion by the fact that 2 2 interesting questions. For these reasons, even after q differs front -m7[. Suppose a pion is exchanged so many years of research on pions, we still try to between two nucleons as in a two-nualeon scattering learn more about them and will continue to do so. process of Fig.1. Here the pion is space-like. This means simply that in my metric qL: is a positive Nuclear Physics bas developed on the con- quantity. Now if all the nucleons are inside a nu- cept of potential. Much of low-energy properties cleus (in other words, within the Fermi sea), then studied in nuclear laboratories depend intimately Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1972512 even by a virtual pion. Nevertheless this one plays a very important role for pion physics and has also a great deal of relevance even for interactigns with nuclei. The point corresponding to q =m 0 T( and lGl= 0 evidently describes a real pion at, rest and we call it the threshold. A pion being ex- changed in a nucleus docs not have well-defined 121, and qo . They range over a considerable spread in although may be localized within a small Fig.1 (GI , qo One-pion exchange graph in N-N collision strip. On the average, a single-pion exchange is 4> centered around q2-m; , so the point relevant for q2 is usually small compared with q6 which is of nuclei ("1n nucleie* in the plot) is for convenience o:der of a few ( kf )2 where kf is the Fermi mo- put at m4 As we will emphasize again and again, mentum, roughly two pion mass. So one can say that 7i . we are interested in the phenomena where the long in a nucleus range one-pion-exchange picture is relevant. 2 q2 rv m (2 > X There has been a considerable progress in Both points (1) and (2) are not too far from the both nuclear and subnuclear physics in describing point where q2 = 0 , certainly if one considers the threshold process involving nucleons starting these on the ather hadron scale, namely nucleon from the soft-pion limit. Like the soft-photon for which is as large as 7m It seems only natural which low-energy theorems are well known, the soft X . then to treat both cases (1) and (2) together, ho- pion limit gives us a model-independent result, ping that it makes some sense. quite similar in many aspects to the soft-photon results. The major progress concerns then the link between this point and the physical threshold. Now it seems reasonable to think that if one can go in 4 the q direction in the /q/ vs. qo plane, one should 1 Physical Threshold also bi able to go in GI direction. Thus one would expect that the soft-pion limit is as relevant to the threshold as to the nuclear matter region. This talk deals thus on a same footing the pion which is exchanged between nucleons and the pion which is produced or captured or scat- ters by nucleons or nuclei, The major advantagedte pion in nuclear physics is that it generates the potential which governs a great deal of nuclear dy- namics as well as it can be used as a probe, diffe- rent from the usual nuclear or efectromagnctic pro- bes. I1 - PlON CLOUD - What takes place when two nu- cleons approach each other at close distance is not k~ownat all. But we think we know a little about I have dram in Pig.2 the points in the what happens when they are at a large distance, say 1:1 1:1 vs. qo plot where the phenomena of our inte- mare than one pion Compton wave length apart. Around rests lie. The origin where I:/ = 0 , qo= 0 is cal- this range and beyond it, one pion exchange is impor- led the "soft-pion limit" which is cloarly an unphy- tant. sical mathematical point. This may not be reached MW ENERGY PIONS ... C5-157 We also know that each nucleon carries a Now how many mesons are exchanged on the average ? meson cloud srctund it. Suppose now two nucleons ap- One can have a rough idea about this by looking at proach each other at a distance at which two clouds the contribution to the norm of the basic Heitler- can overlap. The question one inay ask is, what is London state coming from one, two, ... meson ex- the distribution of meson clouds when there is a changes. This is shown in Fig.4. Clearly, at largo simulated creation and annihilation of pions ? distances, one-meson exchange seems enough. This is -1 There must be a certain distortion but this must certainly so for r > m As the distance becomes 71 . depend upon the distance. The only treatment on smaller, more and more pions are exchanged as one this question that I know of which has some credibi- would expect. lity 1s that of Cutkosky published some 14 years agoC1I. It is based on the Heitler-London model ba- sed on the static approximation. In this model, pat- terned after molecular structure, the simulated ex- change of pions as well as the excitation of nucle- on resonances can be correctly taken into account. The static model tells us that a nucleon carries,on the average, about 3 pions. Thus nun-interacting system of two nucleons would contain roughly 6 pions in the cloud. As the exchange occurs due to inter- actions, the distribution of meson clouds is expec- ted to be distorted. Cutkosky investigated this question and found that the deviation of the avera- ge number of pions in deuteron from that of two iso- lated nucleons was small at large distance, typical- Fig.4 ly $ to 1- pion at the distance of one-pion Campton The ono-, two-, and three-meson contributions to 2 the norm of the basic state in deuteron.
Load more

Recommended publications
  • The\Bar Qq Bound States and Instanton Molecule at T>~
    The qq¯ Bound States and Instanton Molecules at T > TC ∼ Gerald E. Brown, a Chang-Hwan Lee, b Mannque Rho, c,d,e Edward Shuryak a aDepartment of Physics and Astronomy, State University of New York, Stony Brook, NY 11794, USA (E-mail: [email protected], [email protected]) bDepartment of Physics and Nuclear Physics & Radiation Technology Institute (NuRI), Pusan National University, Pusan 609-735, Korea (E-mail: [email protected]) cService de Physique Th´eorique, CEA/DSM/SPhT. Unit´ede recherche associ´ee au CNRS, CEA/Saclay, 91191 Gif-sur-Yvette c´edex, France (E-mail: [email protected]) dSchool of Physics, Korea Institute for Advanced Study, Seoul 130-722, Korea eDepartment of Physics, Hanyang University, Seoul 133-791, Korea Abstract The main objective of this work is to explore the evolution in the structure of the quark-anti-quark bound states in going down in the chirally restored phase from the so-called “zero binding points” Tzb to the full (unquenched) QCD critical temperature Tc at which the Nambu-Goldstone and Wigner-Weyl modes meet. In arXiv:hep-ph/0312175v3 25 May 2004 doing this, we adopt the idea recently introduced by Shuryak and Zahed for charmed cc¯ , light-quarkqq ¯ mesons π, σ, ρ, A1 and gluons that at Tzb, the quark-anti-quark scattering length goes through at which conformal invariance is restored, thereby ∞ transforming the matter into a near perfect fluid behaving hydrodynamically, as found at RHIC. We show that the binding of these states is accomplished by the combination of (i) the color Coulomb interaction, (ii) the relativistic effects, and (iii) the interaction induced by the instanton-anti-instanton molecules.
    [Show full text]
  • Service De Physique Théorique
    ff^tfOO 1Û^\ COMMISSARIAT A L'ÉNERGIE ATOMIQUE DIVISION DE LA PHYSIQUE SERVICE DE PHYSIQUE THÉORIQUE THE QUARK MATTEk by Mannque RHO Ettore majorana "school on nuclear astrophysics, „ Erice, Italy, March 25 - April 6, 1980. ', CEA - CONF 5194 CEN-SACLAY - BOITE POSTALE N° 2 - 91190 GIF-S/-YVETTE - * • -- • THE QUARK MATTER Nannque RHO Service de Physique Théorique CEN Siclay. 91190 Gif-sur-Yvette, France Lectures given at the "Ettore Majorana" School on Nuclear Astrophysics, Erice, Sicily (Italy) (25 March - 6 April 1980). 1 I. INTRODUCTION In this series of lectures I will discuss the present status of ojr understanding of the physics of hadronic (nuclear or neutron) matter under extreme conditions, in particular at high densities. This is a problem which challenges three disci• plines of physics : nuclear physics, astrophysics and particle physics. It is ge• nerally believed that we now have a correct and perhaps ultimate theory of the strong interactions, namely quantum chromodynamics (QCD). The constituents of this theery are quarks and gluons, so highly dense matters should be describable in terms of these constituents alone. This is a question that addresses directly to the phenomenon of quark confinement, one of the least understood aspects in par• ticle physics. For nuclear physics, the possibility of a phase change between nuclear matter and quark matter introduces entirely new degrees of freedom in the description of nuclei and will bring perhaps a deeper understanding of nuclear dynamics. In astrophysics, the properties of neutron stars will.be properly under• stood only when the equation of state of "neutron" matter at densities exceeding that of nuclear matter can be realiably calculated.
    [Show full text]
  • Table of Contents (Print)
    PERIODICALS PHYSICAL REVIEW Dä For editorial and subscription correspondence, Postmaster send address changes to: please see inside front cover (ISSN: 1550-7998) APS Subscription Services P.O. Box 41 Annapolis Junction, MD 20701 THIRD SERIES, VOLUME 92, NUMBER 5 CONTENTS D1 SEPTEMBER 2015 EDITORIALS Editorial: General Relativity Still Making Waves (2 pages) ........................................................................... 050001 Clifford Will RAPID COMMUNICATIONS Observation of η0 → ωeþe− (8 pages) ..................................................................................................... 051101(R) M. Ablikim et al. (BESIII Collaboration) þ þ Measurement of the branching fraction of B → τ ντ decays with the semileptonic tagging method (8 pages) ............ 051102(R) B. Kronenbitter et al. (Belle Collaboration) Transformative A4 mixing of neutrinos with CP violation (5 pages) ................................................................ 051301(R) Ernest Ma Reconstruction of energy spectra of neutrino beams independent of nuclear effects (6 pages) .................................. 051302(R) X.-G. Lu, D. Coplowe, R. Shah, G. Barr, D. Wark, and A. Weber þ þ Pentaquark candidates Pc ð4380Þ and Pc ð4450Þ within the soliton picture of baryons (5 pages) .............................. 051501(R) N. N. Scoccola, D. O. Riska, and Mannque Rho ARTICLES Study of W boson production in association with beauty and charm (16 pages) .................................................. 052001 R. Aaij et al. (LHCb Collaboration) pffiffiffi
    [Show full text]
  • Recent Progress on Dense Nuclear Matter in Skyrmion Approaches Yong-Liang Ma, Mannque Rho
    Recent progress on dense nuclear matter in skyrmion approaches Yong-Liang Ma, Mannque Rho To cite this version: Yong-Liang Ma, Mannque Rho. Recent progress on dense nuclear matter in skyrmion approaches. SCIENCE CHINA Physics, Mechanics & Astronomy, 2017, 60, pp.032001. 10.1007/s11433-016-0497- 2. cea-01491871 HAL Id: cea-01491871 https://hal-cea.archives-ouvertes.fr/cea-01491871 Submitted on 17 Mar 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. SCIENCE CHINA Physics, Mechanics & Astronomy . Invited Review . Month 2016 Vol. *** No. ***: ****** doi: ******** Recent progress on dense nuclear matter in skyrmion approaches Yong-Liang Ma1 & Mannque Rho2 1Center of Theoretical Physics and College of Physics, Jilin University, Changchun, 130012, China; Email:[email protected] 2Institut de Physique Th´eorique, CEA Saclay, 91191 Gif-sur-Yvette c´edex, France; Email:[email protected] The Skyrme model provides a novel unified approach to nuclear physics. In this approach, single baryon, baryonic matter and medium-modified hadron properties are treated on the same footing. Intrinsic density dependence (IDD) reflecting the change of vacuum by compressed baryonic matter figures naturally in the approach. In this article, we review the recent progress on accessing dense nuclear matter by putting baryons treated as solitons, namely, skyrmions, on crystal lattice with accents on the implications in compact stars.
    [Show full text]
  • Physics & Astronomy
    Peter Koch, 9 September 2008 Physics & Astronomy – Our Community Another Friday afternoon (29 August 2008) A Friday afternoon (17 August 2007) DepartmentDepartment StaffStaff Peter Koch, Chair Pam Burris, Assistant to the Chair Laszlo Mihaly, Graduate Program Director Pat Peiliker, Assistant Graduate Program Director Phil Allen, Undergraduate Program Director Elaine Larsen, Assistant Undergraduate Program Director Bob Segnini, Director of Physical Laboratories Rich Berscak, Building Manager Sara Lutterbie, Business Officer Maria Hofer, Main Office Diane Diaferia, Main Office Joe Feliciano and Frank Chin, Instructional Laboratories Chuck Pancake and Gene Shafto, Electronics Center Walt Schmeling and crew, Machine Shop Sal Natale, Receiving Since 1999 we have been “fenced in” to our building when some bricks fell off the façade. The ~2 M$ fix to the roof and bricks has been completed. HELP! Removal of the scaffolding and fencing around the building is now underway !!! The “fixing the concrete deck” project is now out for bid. Start/completion date: ??? thanks to Sara Lutterbie for making this slide New faculty Stan Metchev, observational astronomer, just joined us as Assistant Professor. He was a Spitzer Postdoc at UCLA. Stan’s research focuses on understanding the physical properties and dynamical evolution of extrasolar planetary systems and brown dwarfs - objects with intermediate characteristics between those of stars and gas giant planets. Stan uses the high-contrast imaging capabilities of the Hubble Space Telescope and ground-based telescopes equipped with adaptive optics systems to resolve protoplanetary disks around young stars. Resolved images of such circumstellar disks allow us to study the formation and architectures of extrasolar planetary systems. Stan uses sensitive optical to infrared spectroscopy to characterize the atmospheres of brown dwarfs at all ages.
    [Show full text]
  • Arxiv:Nucl-Th/9412025V1 16 Dec 1994 Omls.Teecag Urn Orcini on Ob (4 Be to Found Is Correction Current Exchange the Order Formalism
    SNUTP 94-124 RADIATIVE NEUTRON-PROTON CAPTURE IN EFFECTIVE CHIRAL LAGRANGIANS Tae-Sun Park and Dong-Pil Min Department of Physics and Center for Theoretical Physics Seoul National University, Seoul 151-742, Korea Mannque Rho Service de Physique Th´eorique, CEA Saclay 91191 Gif-sur-Yvette Cedex, France Abstract We calculate the cross-section for the thermal n + p d + γ process in chi- → ral perturbation theory to next-to-next-to-leading order using heavy-fermion formalism. The exchange current correction is found to be (4.5 0.3) % in ± amplitude and the chiral perturbation at one-loop order gives the cross sec- tion σnp = (334 2) mb which is in agreement with the experimental value th ± (334.2 0.5) mb. Together with the axial charge transitions, this provides a ± strong support for the power of chiral Lagrangians for nuclear physics. PACS: 12.39.Fe 21.30.+y 21.10.Ky 25.40.Lw arXiv:nucl-th/9412025v1 16 Dec 1994 Typeset using REVTEX 1 One of the corner-stones of nuclear physics is the successful explanation in terms of exchange currents given two decades ago by Riska and Brown [1] of the 10% discrepancy ∼ between the experimental cross-section and the theoretical impulse approximation prediction for the process n + p d + γ (1) → at threshold. Riska and Brown computed, using a realistic hard-core wave function for the deuteron, the two one-pion-exchange diagrams initially suggested in 1947 by Villars [2] plus the ω and ∆ resonance diagrams. That the dominant contributions to electroweak exchange currents could be gotten from current-algebra low-energy theorems was suggested by Chemtob and Rho [3] who gave a systematic rule for organizing the leading exchange- current diagrams effective at low energy and momentum.
    [Show full text]
  • The Power of Effective Field Theories in Nuclei: the Deuteron, NN
    KIAS-P98015 The Power Of Effective Field Theories In Nuclei: The Deuteron, NN Scattering and Electroweak Processes Tae-Sun Park#1 Grupo de F´ısica Nuclear, Universidad de Salamanca, 37008 Salamanca, Spain and School of Physics, Korea Institute for Advanced Study, Seoul 130-012, Korea Kuniharu Kubodera#2 Department of Physics and Astronomy, University of South Carolina Columbia, SC 29208, U.S.A. Dong-Pil Min#3 Department of Physics and Center for Theoretical Physics Seoul National University, Seoul 151-742, Korea Mannque Rho#4 Service de Physique Th´eorique, CEA Saclay 91191 Gif-sur-Yvette Cedex, France Abstract We show how effectively effective quantum field theories work in nuclear physics. Us- ing the physically transparent cut-off regularization, we study the simplest nuclear systems of two nucleons for both bound and scattering states at a momentum scale much less than the pion mass. We consider all the static properties of the deuteron, the two-nucleon scat- arXiv:nucl-th/9807054v2 18 Nov 1998 tering phase-shifts, the n + p d + γ process at thermal energy and the solar proton fusion + → process p + p d + e + νe, and we demonstrate that these are all described with great → accuracy in the expansion to the next-to-leading order. We explore how a “new” degree of freedom enters in an effective theory by turning on and off the role of the pion in the Lagrangian. PACS: 21.30.Fe, 03.65.Nk, 13.75.Cs, 25.40.Lw, 26.65.+t Key words: effective field theory, NN scattering, deuteron, radiative proton capture, solar proton fusion #1 Corresponding auther.
    [Show full text]
  • Dense Stellar Matter with Strange Quark Matter Driven by Kaon Condensation
    PHYSICAL REVIEW C 84, 035810 (2011) Dense stellar matter with strange quark matter driven by kaon condensation Kyungmin Kim,1,* Hyun Kyu Lee,1,† and Mannque Rho1,2,‡ 1Department of Physics, Hanyang University, Seoul 133-791, Korea 2Institut de Physique The´orique, Direction des Sciences de la Matie`re, CEA Saclay, F-91191 Gif-sur-Yvette, France (Received 23 March 2011; published 28 September 2011) The core of neutron-star matter is supposed to be at a much higher density than the normal nuclear-matter density, for which various possibilities have been suggested, such as, for example, meson or hyperon condensation and/or deconfined quark or color-superconducting matter. In this work, we explore the implication on hadron physics of a dense compact object that has three “phases”: nuclear matter at the outer layer, kaon condensed nuclear matter in the middle, and strange quark matter at the core. Using a drastically simplified but not unreasonable model, we develop the scenario where the different phases are smoothly connected with the kaon condensed matter playing a role of a “doorway” to a quark core, the equation of state of which with parameters restricted within the range allowed by nature could be made compatible with the mass vs radius constraint given by the 1.97-solar-mass object PSR J1614-2230 recently observed. DOI: 10.1103/PhysRevC.84.035810 PACS number(s): 97.60.Jd, 26.60.Dd, 26.60.Kp, 12.39.Fe I. INTRODUCTION determine the equation of state (EoS) for both symmetric and asymmetric systems up to the normal nuclear-matter The recent observation of a 1.97-solar-mass (M) neutron density ρ .
    [Show full text]
  • Baryons and Vector Dominance in Holographic Dual
    1 Baryons and Vector Dominance in Holographic Dual QCD Mannque Rho Institut de Physique Th´eorique, Direction des Sciences de la Mati`ere, CEA-Saclay, F-91191 Gif-sur-Yvette, France The infinite tower of vector mesons encoded in holographic dual QCD bring drastic changes to the soliton structure of the nucleon. The nucleon is given by a point-like instanton in 5D surrounded by a vector meson cloud with the vector dominance restored by the infinite tower. I discuss the possible relevance of this structure in hot and dense hadronic matter. §1. The Objective I would like to discuss in this talk a particular aspect of baryon structure that arises from holographic dual QCD (hQCD for short) that has an important ramifica- tion on some current issues of nuclear/hadronic physics. My talk will be largely mo- tivated by the series of work1), 2) I have done recently with my string theory/particle physics colleagues in Korea. This work addressed broadly two different issues. As nicely exposed in the recent talks by my colleagues,3), 4) to string theorists, it is al- ready quite surprising that the notion of gravity/gauge duality can access certain properties of the baryons at such an accuracy, say, 10% level. Here string theory ∼ purports to first ascertain how well it postdicts the baryon properties well described by QCD proper or rather by its effective field theories and then to address problems that go beyond the standard model, e.g., baryon decay,5) just to cite one. What I am interested in here is quite different in nature.
    [Show full text]
  • Arxiv:2107.01879V2 [Nucl-Th] 22 Jul 2021 [email protected] § [email protected] J = (38.1 ± 4.7) Mev,L = (106 ± 37) Mev
    Cusp in the Symmetry Energy, PREX-II And Pseudo-Conformal Sound Speed in Neutron Stars Hyun Kyu Lee,1, ∗ Yong-Liang Ma,2, 3, y Won-Gi Paeng,4, z and Mannque Rho5, x 1Department of Physics, Hanyang University, Seoul 133-791, Korea 2School of Fundamental Physics and Mathematical Sciences, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, 310024, China 3International Center for Theoretical Physics Asia-Pacific (ICTP-AP) (Beijing/Hangzhou), UCAS, Beijing 100190, China 4A I Lab., Clunix, Seoul 07209, Korea 5Institut de Physique Th´eorique,Universit´eParis-Saclay, CNRS, CEA, 91191, Gif-sur-Yvette, France (Dated: July 23, 2021) The recent announcement of the PREX-II measurement of the neutron skin of 208Pb that suggests a stiff symmetry energy near nuclear matter density n0 and its impact on the EoS of massive compact stars raise the issue as to whether the widely accepted lore in nuclear astrophysics that the EoS determined at n0 necessarily gives a stringent \constraint" at high densities relevant to massive compact stars. We present the argument that the \cusp" structure in the symmetry energy at n1=2 >∼ 2n0 predicted by a topology change in dense matter could obstruct the validity of the lore. The topology change, encoding the emergence of QCD degrees of freedom in terms of hidden local and scale symmetries, predicts an EoS that is soft below and stiff above n >∼ n1=2, involving no low-order phase transitions, and yields the macrophysical properties of neutron stars overall consistent with the astrophysical observations including the maximum mass 2:0 <∼ M=M <∼ 2:2 as well as the GW data.
    [Show full text]
  • DELTA-NUCLEUS DYNAMICS May 2-3, 1983 at Argonne National Laboratory
    Distribution Category: Physics—lh»cl«*r (UC-34C) AHL-PHY-83-1 M84003655 C0MF-830S88 MJL-PHY—-83-1 DB84 003655 PROCEEDINGS OF THE SYMPOSIUM ON DELTA-NUCLEUS DYNAMICS May 2-3, 1983 at Argonne National Laboratory Edited by T.-S. H. Lee D. F. Geesaman J. P. Schiffer Organizing Committee Scientific Advisory Conaittee D. F. Geesaman 6. E. Brown (SUNY) T.-S. H. Lee C. H. Q. Ingram (SIN) J. P. Schiffer E. J. Moniz (MIT) E. Vogt (TRIDMF) J. D. Walecka (Stanford) Jointly sponsored by Physics Division, Argonne National Laboratory and The University of Chicago October 1983 mm EOTICE PORTIONS OF THIS REPORT ARC JLLEHll^. A limited nwiber of oopiea of this report ore available for general It he* been reprocmcei from tho distribution. For Ji&ther copies, evaflaMt copy to permit Dm contact T.-S. H. Lee, Physics Div.t Argonne National laboratory, Argonnej Illinois, 60439. f: OF THIS DOCUMENT IS f i ii Introduction The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta A(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reaction* induced by intermediate energy pious, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of iov-enurgy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe A-nucleus dynamics at all energies.
    [Show full text]
  • Heavy Quark Symmetry and the Skyrme Model
    SNUTP-94/13 (Revised) Heavy Quark Symmetry and the Skyrme Model Yongseok Oh Department of Physics, National Taiwan University, Taipei, Taiwan 10764, R.O.C. Byung-Yoon Park Department of Physics, Chungnam National University, Daejeon 305–764, Korea Dong-Pil Min Center for Theoretical Physics and Department of Physics, Seoul National University, Seoul 151–742, Korea Abstract We present a consistent way of describing heavy baryons containing a heavy quark as bound states of an SU(2) soliton and heavy mesons. The resulting mass formula reveals the heavy quark symmetry explicitly. By extending the model to the orbitally excited states, we establish the generic structure of the heavy baryon spectrum. As anticipated from the heavy quark spin symmetry, the c-factor denoting the hyperfine splitting constant vanishes and the baryons with the same angular momentum of light degrees of freedom form degenerate doublets. This approach is also applied to the pentaquark exotic baryons, where the conventional c-factor plays no more a role of the 1 hyperfine constant. After diagonalizing the Hamiltonian of order Nc− , we arXiv:hep-ph/9407214v1 4 Jul 1994 get the degenerate doublets, which implies the vanishing of genuine hyperfine splitting. PACS number(s): 12.39.Dc, 12.39.Hg, 14.20.Lq, 14.20.Mr Typeset using REVTEX 1 I. INTRODUCTION Hadrons containing a single heavy quark (Q) with its mass (mQ) much greater than a typical scale of strong interactions (ΛQCD) can be viewed as a freely propagating point-like color source dressed by light degrees of freedom such as light quarks and gluons.
    [Show full text]