Thu·Mar 3, 2016Thursday·March 3, 2016

1. 01*

   An above-barrier narrow resonance in ${}^{15}$F

   F. De Grancey (GANIL)🇫🇷 · A. Mercenne (GANIL)🇫🇷 · F. de Oliveira Santos (GANIL)🇫🇷 · T. Davinson🇬🇧 · O. Sorlin (GANIL)🇫🇷 · J.C. Angélique (LPCC)🇫🇷 · M. Assié (IPNO, GANIL)🇫🇷 · E. Berthoumieux (IRFU)🇫🇷 · R. Borcea🇷🇴 · A. Buta🇷🇴 · I. Celikovic🇷🇸 · V. Chudoba🇨🇿 and 28 other authors

   Intense and purified radioactive beam of post-accelerated ${}^{14}$O was used to study the low-lying states in the unbound ${}^{15}$F nucleus. Exploiting resonant elastic scattering in inverse kinematics with a thick target, the second excited state, a resonance at E$\_R$=4.757(6)(10)~MeV with a width of $\Gamma$=36(5)(14)~keV was measured for the first time with high precision. The structure of this narrow above-barrier state in a nucleus located two neutrons beyond the proton drip line was investigated using the Gamow Shell Model in the coupled channel representation with a ${}^{12}$C core and three valence protons. It is found that it is an almost pure wave function of two quasi-bound protons in the $2s\_1/2$ shell.

   nucl-exPLB(2016)·37 citations
2. 02*

   Open Heavy Flavor in QCD Matter and in Nuclear Collisions

   Francesco Prino🇮🇹 · Ralf Rapp🇺🇸

   We review the experimental and theoretical status of open heavy-flavor (HF) production in high-energy nuclear collisions at RHIC and LHC. We first overview the theoretical concepts and pertinent calculations of HF transport in QCD matter, including perturbative and non-perturbative approaches in the quark-gluon plasma, effective models in hadronic matter, as well as implementations of heavy-quark (HQ) hadronization. This is followed by a brief discussion of bulk evolution models for heavy-ion collisions and initial conditions for the HQ distributions which are needed to calculate HF spectra in comparison to observables. We then turn to a discussion of experimental data that have been collected to date at RHIC and LHC, specifically for the nuclear suppression factor and elliptic flow of semileptonic HF decays, D mesons, non-prompt $J/\psi$ from B-meson decays, and b-jets. Model comparisons to HF data are conducted with regards to extracting the magnitude, temperature and momentum-dependence of HF transport coefficients from experiment.

   nucl-exhep-exhep-phnucl-thJ.Phys.G(2016)·221 citations
3. 03*

   Reply to Comment on "New formulas for the $(-2)$ moment of the photo-absorption cross section, ${\sigma }_{{}_{-2}}$"

   Nico Orce🇨🇦

   This is a Reply to a Comment on my paper: New formulas for the (-2) moment of the photo-absorption cross section, sigma-2.

   nucl-ex0 citations
4. 04*

   Constraining the density dependence of the symmetry energy using the multiplicity and average $p_T$ ratios of charged pions

   M.D. Cozma🇷🇴

   The charged pion multiplicity ratio in intermediate energy heavy-ion collisions, a probe of the density dependence of symmetry energy above the saturation point, has been proven in a previous study to be extremely sensitive to the strength of the isovector $\Delta$(1232) potential in nuclear matter. As there is no knowledge, either from theory or experiment, about the magnitude of this quantity, the extraction of constraints on the slope of the symmetry energy at saturation by using exclusively the mentioned observable is hindered at present. It is shown that, by including the ratio of average $p_T$ of charged pions $⟨p_T^{({\pi }^{+})}⟩/⟨p_T^{({\pi }^{-})}⟩$ in the list of fitted observables, the noted problem can be circumvented. A realistic description of this observable requires accounting for the interaction of pions with the dense nuclear matter environment by the incorporation of the so called $S$-wave and $P$-wave pion optical potentials. This is performed within the framework of a quantum molecular dynamics transport model that enforces the conservation of the total energy of the system. It is shown that constraints on the slope of the symmetry energy at saturation density and the strength of the $\Delta$(1232) potential can be simultaneously extracted. A symmetry energy with a value of the slope parameter $L>$ 50 MeV is favored, at 1$\sigma$ confidence level, from a comparison with published FOPI experimental data. A precise constraint will require experimental data more accurate than presently available, particularly for the charged pion multiplicity ratio, and better knowledge of the density and momentum dependence of the pion potential for the whole range of these two variables probed in intermediate energy heavy-ion collisions.

   ↳ nucl-thnucl-exPRC(2017)·52 citations
5. 05*

   Tagged spectator deep-inelastic scattering off the deuteron as a tool to study neutron structure

   W. Cosyn🇧🇪 · M. Sargsian🇺🇸

   We give an overview of a model to describe deep-inelastic scattering (DIS) off the deuteron with a spectator proton, based on the virtual nucleon approximation (VNA). The model accounts for the final-state interactions (FSI) of the DIS debris with the spectator proton. Values of the rescattering cross section are obtained by fits to high-momentum spectator data. By using the so-called "pole extrapolation method", free neutron structure functions can be obtained by extrapolating low-momentum spectator proton data to the on-shell neutron pole. We apply this method to the BONuS data set and find a surprising Bjorken $x$ dependence, indicating a possible rise of the neutron to proton structure function ratio at high $x$.

   ↳ nucl-thnucl-exEPJ Web Conf.(2016)·1 citation

* 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.