PaperPanorama
FAQ

Nuclear Theory·nucl-th

Tuesday·June 2, 2015

8 papers—5 primary·3 cross-listed

All8Primary5Cross-lists3
  1. 06

    Cherenkov and Fano effects at the origin of asymmetric vector mesons in nuclear media

    I.M. Dremin🇷🇺

    It is argued that the experimentally observed phenomenon of asymmetric vector mesons produced in nuclear media during high energy nucleus-nucleus collisions can be explained as Cherenkov and Fano effects. The mass distributions of lepton pairs created at meson decays decline from the traditional Breit-Wigner shape in the low-mass wing of the resonance. That is explained by the positive real part of the amplitude in this wing for classic Cherenkov treatment and further detalized in quantum mechanics as the interference of direct and continuum states in Fano effect. The corresponding parameters are found from the comparison with rho-meson data and admit reasonable explanation.

    ↳ hep-phhep-exnucl-exnucl-th0 citations
  2. 07

    Matrix model and Holographic Baryons in the D0-D4 background

    Si-wen Li🇨🇳 · Tuo Jia🇨🇳

    We study on the spectrum and short-distance two-body force of holographic baryons by the matrix model, which is derived from Sakai-Sugimoto model in D0-D4 background (D0-D4/D8 system). The matrix model is derived by using the standard technique in string theory and it can describe multi-baryon system. We re-derive the action of the matrix model from open string theory on the wrapped baryon vertex, which is embedded in the D0- D4/D8 system. The matrix model offers a more systematic approach to the dynamics of the baryons at short distances. In our system, we find that the matrix model describe stable baryonic states only if , where is related to the number density of smeared D0-branes. This result in our paper is exactly the same as some previous presented results studied on this system as \cite{key-24 Baryons in D0-D4}. We also compute the baryon spectrum ( case) and short-distance two-body force of baryons ( case). The baryon spectrum is modified and could be able to fit the experimental data if we choose suitable value for . And the short-distance two-body force of baryons is also modified by the appearance of smeared D0-branes from the original Sakai-Sugimoto model. If , we find that the baryon spectrum would be totally complex and an attractive force will appear in the short-distance interaction of baryons, which may consistently correspond to the existence of unstable baryonic states.

    ↳ hep-thnucl-thPRD(2015)·23 citations
  3. 08

    Mean pt scaling with m/nq at the LHC: Absence of (hydro) flow in small systems?

    Antonio Ortiz🇲🇽

    In this work, a study of the average transverse momentum (pt) as a function of the mid-rapidity charged hadron multiplicity (Nch) and hadron mass (m) in p-Pb and Pb-Pb collisions at LHC energies is presented. For the events producing low Nch, the average pt is found to scale with the reduced hadron mass, i.e., mass divided by the number of quark constituents (m/nq), this scaling also holds for inelastic pp collisions at RHIC and LHC energies. The scaling is broken in high multiplicity p-Pb and Pb-Pb collisions, where, for <Nch/deta> < 60 the average pt is higher for baryons than that for mesons, though they increase linearly with m/nq. This behavior is qualitatively well reproduced by Pythia 8, but not by hydro calculations, where an universal scaling with the hadron mass (and not with m/nq) is predicted for all the multiplicity event classes. Only the central (0-60%) Pb-Pb collisions behave as expected from hydro.

    ↳ hep-phnucl-thNPA(2015)·20 citations

Affiliations

first authorsco-authorsvia INSPIRE