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Nuclear Theory·nucl-th

Tuesday·October 11, 2022

18 papers—12 primary·6 cross-listed

All18Primary12Cross-lists6
  1. 13

    Production of and production in ultra-peripheral collisions with two-photon processes

    Gongming Yu🇨🇳 · Yanbing Cai🇨🇳 · Quangui Gao🇨🇳 · Qiang Hu🇨🇳

    We calculate the production of and by the semi-coherent and coherent two-photon interaction in ultra-peripheral heavy ion collisions at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies. The differential cross section of transverse momentum distribution and rapidity distribution for (H= and ), are estimated by using the equivalent photon approximation in ultra-peripheral nucleus-nucleus collisions. The numerical results demonstrate that the experimental study of and in ultra-peripheral nucleus-nucleus collisions is feasible at RHIC and LHC energies.

    ↳ hep-phnucl-th0 citations
  2. 14

    A convolution formalism for defining spatial densities of hadrons

    Adam Freese🇺🇸 · Gerald A. Miller🇺🇸

    We clarify the meaning of spatial densities of hadrons. A physical density is given by the expectation value of a local operator for a physical state, and depends on both internal structure and the hadron's wave packet. In some particular cases, the physical density can be written as a convolution between a density function that depends on internal structure but not wave packet, and a smearing function that depends on wave packet but not internal structure. We show that the light front densities often encountered in the literature have this property but that instant form densities do not. For hadrons prepared in broad wave packets, physical instant form densities approximately obey such a convolution relation, with Breit frame densities as the apparent internal densities. However, there is an infinite series of relativistic corrections to this convolution formula.

    ↳ hep-phnucl-thPRD(2023)·34 citations
  4. 16

    Revealing the short-range structure of the "mirror nuclei" H and He

    S.Li🇺🇸 · R.Cruz-Torres🇺🇸 · N.Santiesteban🇺🇸 · Z.H.Ye🇨🇳 · D.Abrams🇺🇸 · S.Alsalmi🇺🇸 · D.Androic🇭🇷 · K.Aniol🇺🇸 · J.Arrington🇺🇸 · T.Averett🇺🇸 · C.Ayerbe Gayoso🇺🇸 · J.Bane🇺🇸 and 104 other authors

    When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough together to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon-nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly-energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure and mapping out the strength and isospin structure (neutron-proton vs proton-proton pairs) of these virtual excitations is thus critical input for modeling a range of nuclear, particle, and astrophysics measurements. Hitherto measurements used two-nucleon knockout or ``triple-coincidence'' reactions to measure the relative contribution of np- and pp-SRCs by knocking out a proton from the SRC and detecting its partner nucleon (proton or neutron). These measurementsshow that SRCs are almost exclusively np pairs, but had limited statistics and required large model-dependent final-state interaction (FSI) corrections. We report on the first measurement using inclusive scattering from the mirror nuclei H and He to extract the np/pp ratio of SRCs in the A=3 system. We obtain a measure of the np/pp SRC ratio that is an order of magnitude more precise than previous experiments, and find a dramatic deviation from the near-total np dominance observed in heavy nuclei. This result implies an unexpected structure in the high-momentum wavefunction for He and H. Understanding these results will improve our understanding of the short-range part of the N-N interaction.

    ↳ nucl-exhep-exnucl-thNature(2022)·42 citations
  5. 17

    Intermediate-Distance String Effects in Wilson Loops\\ via Boundary Action

    M. N. Khalil🇪🇬 · A. M. Khalaf🇪🇬 · A. S. Bakry🇪🇬 · M. Deliyergiyev🇪🇬 · A. A. Galal🇪🇬 · M. Kotb🇪🇬 · M. D. Okasha🇨🇳 · G. S. M. Ahmed🇨🇭

    The density profile of the QCD flux tube is investigated within the framework of the Lüscher-Weisz (LW) string action with two boundary terms. The transverse action profile and potential between static quarks are considered using Wilson's loop overlap formalism at zero temperature in SU(2) Yang-Mills theory. We find the predictions of the LW string matching the lattice data for the width of the energy-density and potential up to a small color-source separation of \,fm.

    ↳ hep-thhep-lathep-phnucl-thLHEP(2023)·1 citation
  6. 18

    On the Quantum Nature of a Fireball Created in Ultrarelativistic Nuclear Collisions

    V.A. Kizka🇺🇦

    In the article, the fireball formed in the collision of relativistic nuclei is considered as a quantum object. Based on this, an attempt is made to explain the difference in the measurements of hyperon yields in the two experiments - NA49 and NA57. Using the basic principles of quantum mechanics, it was shown that a fireball can have two quantum states - with and without ignited Quark-Gluon Plasma (QGP). With an increase of the collision energy of heavy ions, the probability of QGP ignition increases. At the same time, the probability of the formation of fireball without QGP ignition also remains nonzero even at nuclear collision energies that are much higher than the threshold QGP formation energy, which may be erroneously considered to be fixed and which is intensively sought in modern heavy ion accelerators. Thus, at SPS energy of heavy ion collisions \sqrt{s_{NN}} = 17.3 GeV, which is much higher than the assumed threshold energy of QGP formation in the region around or slightly above of \sqrt{s_{NN}} = 3 GeV, only half of the central collisions of heavy ions bring to the formation of a fireball consisted of deconfined matter, the remaining half of the collisions lead to the formation of a fireball from only hadronic matter.

    ↳ physics.gen-phnucl-thNuclear Collisions. NFPSR-V1 2022, 52-62·1 citation

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first authorsco-authorsvia INSPIRE