Thu·Jul 7, 2011Thursday·July 7, 2011

1. 01*

   ${}^{12}$C+${}^{16}$O sub-barrier radiative capture cross-section measurements

   A. Goasduff🇫🇷 · S. Courtin🇫🇷 · F. Haas🇩🇪 · D. Lebhertz🇫🇷 · D.G. Jenkins🇬🇧 · C. Beck🇫🇷 · J. Fallis🇨🇦 · C. Ruiz🇨🇦 · D. A. Hutcheon🇨🇦 · P.-A. Amandruz · C. Davis🇨🇦 · U. Hager · D. Ottewell · G. Ruprecht🇨🇦

   We have performed a heavy ion radiative capture reaction between two light heavy ions, ${}^{12}$C and ${}^{16}$O, leading to ${}^{28}$Si. The present experiment has been performed below Coulomb barrier energies in order to reduce the phase space and to try to shed light on structural effects. Obtained $\gamma$-spectra display a previously unobserved strong feeding of intermediate states around 11 MeV at these energies. This new decay branch is not fully reproduced by statistical nor semi-statistical decay scenarii and may imply structural effects. Radiative capture cross-sections are extracted from the data.

   nucl-exEPJ Web Conf.(2011)·0 citations
2. 02*

   Suppression of high-pT particle production in AA collisions: the role of in-medium color-flow

   A. Beraudo🇮🇹 · J.G. Milhano🇵🇹 · U.A. Wiedemann🇨🇭

   The suppression of high-pT single-hadron spectra in heavy-ion collisions is usually interpreted as due to parton energy-loss of high-momentum quarks and gluons propagating in the plasma. Here, we discuss to what extent this partonic picture must be complemented by a picture of medium-modified hadronization. In particular, we show how color-exchange with the medium modifies the properties of color singlet-clusters arising from the parton branchings, producing a softening of the hadron spectra.

   ↳ hep-phnucl-exnucl-thJ.Phys.G(2011)·1 citation
3. 03*

   Standard Big-Bang Nucleosynthesis up to CNO with an improved extended nuclear network

   Alain Coc (CSNSM, Orsay, France)🇫🇷 · Stephane Goriely🇧🇪 · Yi Xu (ULB Bruxelles, Belgique)🇧🇪 · Matthias Saimpert🇫🇷 · Elisabeth Vangioni (IAP, Paris, France)🇫🇷

   Primordial or Big Bang nucleosynthesis (BBN) is one of the three strong evidences for the Big- Bang model together with the expansion of the Universe and the Cosmic Microwave Background radiation. In this study, we improve the standard BBN calculations taking into account new nuclear physics analyses and we enlarge the nuclear network until Sodium. This is, in particular, important to evaluate the primitive value of CNO mass fraction that could affect Population III stellar evolution. For the first time we list the complete network of more than 400 reactions with references to the origin of the rates, including \approx 270 reaction rates calculated using the TALYS code. Together with the cosmological light elements, we calculate the primordial Beryllium, Boron, Carbon, Nitrogen and Oxygen nuclei. We performed a sensitivity study to identify the important reactions for CNO, 9Be and Boron nucleosynthesis. We reevaluated those important reaction rates using experimental data and/or theoretical evaluations. The results are compared with precedent calculations: a primordial Beryllium abundance increase by a factor of 4 compared to its previous evaluation, but we note a stability for B/H and for the CNO/H abundance ratio that remains close to its previous value of 0.7 \times 10-15. On the other hand, the extension of the nuclear network has not changed the 7Li value, so its abundance is still 3-4 times greater than its observed spectroscopic value.

   ↳ astro-ph.COastro-ph.HEnucl-exApJ(2012)·169 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.