Fri·Aug 3, 2018Friday·August 3, 2018

1. 01*

   Justification of Landau Hydrodynamic-Tube Model in Central Relativistic Heavy-Ion Collisions

   U. U. Abdurakhmanov🇺🇿 · K. G. Gulamov🇺🇿 · V.V.Lugovoi🇺🇿 · V. Sh. Navotny🇺🇿

   The statistical event-by-event analysis of inelastic interactions of 16O and 32S nuclei in emulsion at 60 A GeV/c and 200 A GeV/c reveals the existence of groups of high multiplicity events belonging to very central nuclear interactions with Gaussian pseudorapidity distributions for produced particles as suggested by the original hydrodynamic-tube model. Characteristics of these events are presented. The experimental observations are interpreted as a result of quark-gluon plasma formation in the course of central nuclear interactions.

   nucl-exnucl-thChin.J.Phys.(2018)·0 citations
2. 02*

   Empirical signatures of shape phase transitions in nuclei with odd nucleon numbers

   D. Bucurescu🇷🇴 · N.V. Zamfir🇷🇴

   Nuclear level density at low excitation energies is proposed as an indicator of the first order phase transitions in nuclei. The new signature, a maximum value of the level density at the critical point, appears to be sensitive to the detailed way the phase transition takes place in different nuclear regions: it is consistent with phase coexistence in the N=90 region, and with a rapid crossing of the two phases, without their coexistence/mixing at the critical point in the N=60 region, respectively. Candidates for critical point nuclei are proposed for odd-mass and odd-odd nuclei, using correlations between relative excitation energies, and their ratios, for structures (bands) based on unique-parity orbitals.

   ↳ nucl-thnucl-exPRC(2018)·11 citations
3. 03*

   Direct and indirect $\alpha$ transfer in the elastic ${}^{16}$O+${}^{12}$C scattering

   Nguyen Tri Toan Phuc🇻🇳 · Nguyen Hoang Phuc🇻🇳 · Dao T. Khoa🇻🇳

   The extensive elastic ${}^{16}$O+${}^{12}$C scattering data measured at low energies show consistently an oscillating enhancement of the elastic cross section at backward angles that is difficult to describe within the conventional optical model. Given the significant $\alpha$ spectroscopic factors predicted for the dissociation ${}^{16}$O$\to \alpha {+}^{12}$C by the shell model (SM) and $\alpha$-cluster model calculations, the contribution of the $\alpha$ transfer channels to the elastic ${}^{16}$O+${}^{12}$C scattering should not be negligible, and is expected to account for the enhanced oscillation of the elastic cross section at backward angles. To reveal the impact of the $\alpha$ transfer, a systematic coupled reaction channels (CRC) analysis of the elastic ${}^{16}$O+${}^{12}$C scattering has been performed where the multistep couplings between the elastic and inelastic scattering channels, the direct and indirect $\alpha$ transfer channels were treated explicitly, using the real optical potentials and inelastic scattering form factors determined by the double-folding model. We show that a consistent CRC description of the elastic ${}^{16}$O+${}^{12}$C data at different energies can be obtained over the whole angular region, using the $\alpha$ spectroscopic factors determined recently in the large scale SM calculation. The present CRC results are, therefore, of interest not only for the nuclear scattering studies but also provide an important spectroscopic information on the cluster dissociation of ${}^{16}$O.

   ↳ nucl-thnucl-exPRC(2018)·15 citations
4. 04*

   Nucleon dissociation and incoherent $J/\psi$ photoproduction on nuclei in ion ultraperipheral collisions at the CERN Large Hadron Collider

   V. Guzey (Jyvaskyla U., Helsinki Inst. of Phys, St. Petersburg, INP)🇷🇺 · M. Strikman (Penn State U.)🇺🇸 · M. Zhalov (St. Petersburg, INP)🇷🇺

   Using the general notion of cross section fluctuations in hadron--nucleus scattering at high energies, we derive an expression for the cross section of incoherent $J/\psi$ photoproduction on heavy nuclei $d{\sigma }_{\gamma A\to J/\psi Y}/dt$, which includes both elastic $d{\sigma }_{\gamma p\to J/\psi p}/dt$ and proton-dissociation $d{\sigma }_{\gamma p\to J/\psi Y}/dt$ photoproduction on target nucleons. We find that with good accuracy, $d{\sigma }_{\gamma A\to J/\psi Y}/dt$ can be expressed as a product of the sum of the $d{\sigma }_{\gamma p\to J/\psi p}/dt$ and $d{\sigma }_{\gamma p\to J/\psi Y}/dt$ cross sections, which have been measured at HERA, and the common nuclear shadowing factor, which is calculated using the leading twist nuclear shadowing model. Our prediction for the cross section of incoherent $J/\psi$ photoproduction in Pb-Pb UPCs at $\sqrt{s_{NN}}=2.76$ TeV and $y=0$, $d{\sigma }_{AA\to J/\psi AY}(y=0)/dy=0.59-1.24$ mb, agrees within significant theoretical uncertainties with the data of the ALICE collaboration.

   ↳ hep-phnucl-exPRC(2019)·32 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.