Fri·Dec 5, 2014Friday·December 5, 2014

1. 01*

   Measurement and analysis of the Am-243 neutron capture cross section at the n_TOF facility at CERN

   n_TOF Collaboration: E. Mendoza🇪🇸 · D. Cano-Ott🇪🇸 · C. Guerrero🇨🇭 · E. Berthoumieux🇫🇷 · U. Abbondanno🇮🇹 · G. Aerts🇫🇷 · F. Alvarez-Velarde🇪🇸 · S. Andriamonje🇫🇷 · J. Andrzejewski🇵🇱 · P. Assimakopoulos🇬🇷 · L. Audouin🇫🇷 · G. Badurek🇦🇹 and 119 other authors

   Background:The design of new nuclear reactors and transmutation devices requires to reduce the present neutron cross section uncertainties of minor actinides. Purpose: Reduce the ${}^{243}$Am(n,$\gamma$) cross section uncertainty. Method: The ${}^{243}$Am(n,$\gamma$) cross section has been measured at the n_TOF facility at CERN with a BaF${}_2$ Total Absorption Calorimeter, in the energy range between 0.7 eV and 2.5 keV. Results: The ${}^{243}$Am(n,$\gamma$) cross section has been successfully measured in the mentioned energy range. The resolved resonance region has been extended from 250 eV up to 400 eV. In the unresolved resonance region our results are compatible with one of the two incompatible capture data sets available below 2.5 keV. The data available in EXFOR and in the literature has been used to perform a simple analysis above 2.5 keV. Conclusions: The results of this measurement contribute to reduce the ${}^{243}$Am(n,$\gamma$) cross section uncertainty and suggest that this cross section is underestimated up to 25% in the neutron energy range between 50 eV and a few keV in the present evaluated data libraries.

   nucl-exPRC(2014)·16 citations
2. 02*

   Directed Flow Indicates a Crossover Deconfinement Transition in Relativistic Nuclear Collisions

   Yu. B. Ivanov🇷🇺 · A. A. Soldatov🇷🇺

   Analysis of directed flow ($v_1$) of protons, antiprotons and pions in heavy-ion collisions is performed in the range of incident energies $\sqrt{s_{NN}}$ = 2.7--27 GeV. Simulations have been done within a three-fluid model employing a purely hadronic equation of state (EoS) and two versions of the EoS involving deconfinement transitions: a first-order phase transition and a smooth crossover transition. High sensitivity of the directed flow, especially the proton one, to the EoS is found. The crossover EoS is favored by the most part of considered experimental data. A strong wiggle in the excitation function of the proton $v_1$ slope at the midrapidity obtained with the first-order-phase-transition EoS and a smooth proton $v_1$ with positive midrapidity slope, within the hadronic EoS unambiguously disagree with the data. The pion and antiproton $v_1$ also definitely testify in favor of the crossover EoS. The results obtained with deconfinement EoS's apparently indicate that these EoS's in the quark-gluon sector should be stiffer at high baryon densities than those used in the calculation.

   ↳ nucl-thhep-phnucl-exPRC(2015)·77 citations
3. 03*

   Time over threshold in the presence of noise

   F. Gonnella🇮🇹 · V. Kozhuharov🇧🇬 · M. Raggi🇮🇹

   The time over threshold is a widely used quantity to describe signals from various detectors in particle physics. Its electronics implementation is straightforward and in this paper we present the studies of its behavior in the presence of noise. A unique comb-like structure was identified in the data for a first time and was explained and modeled successfully. The effects of that structure on the efficiency and resolution are also discussed.

   ↳ physics.ins-dethep-exnucl-exNucl.Instrum.Meth.A(2015)·8 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.