Fri·Nov 4, 2016Friday·November 4, 2016

1. 01*

   $\alpha$-scattering and $\alpha$-induced reaction cross sections of ${}^{64}$Zn at low energies

   A. Ornelas · P. Mohr🇭🇺 · Gy. Gyürky🇭🇺 · Z. Elekes🇭🇺 · Zs. Fülöp🇭🇺 · Z. Halász🇭🇺 · G.G. Kiss🇭🇺 · E. Somorjai🇭🇺 · T. Szücs🇭🇺 · M. P. Takács🇩🇪 · D. Galaviz🇵🇹 · R. T. Güray and 3 other authors

   Background: alpha-nucleus potentials play an essential role for the calculation of alpha-induced reaction cross sections at low energies in the statistical model... Purpose: The present work studies the total reaction cross section sigma_reac of alpha-induced reactions at low energies which can be determined from the elastic scattering angular distribution or from the sum over the cross sections of all open non-elastic channels. Method: Elastic and inelastic 64Zn(a,a)64Zn angular distributions were measured at two energies around the Coulomb barrier at 12.1 MeV and 16.1 MeV. Reaction cross sections of the (a,g), (a,n), and (a,p) reactions were measured at the same energies using the activation technique. The contributions of missing non-elastic channels were estimated from statistical model calculations. Results: The total reaction cross sections from elastic scattering and from the sum of the cross sections over all open non-elastic channels agree well within the uncertainties. This finding confirms the consistency of the experimental data. At the higher energy of 16.1 MeV, the predicted significant contribution of compound-inelastic scattering to the total reaction cross section is confirmed experimentally. As a by-product it is found that most recent global alpha-nucleus potentials are able to describe the reaction cross sections for 64Zn around the Coulomb barrier. Conclusions: Total reaction cross sections of alpha-induced reactions can be well determined from elastic scattering angular distributions. The present study proves experimentally that the total cross section from elastic scattering is identical to the sum of non-elastic reaction cross sections. Thus, the statistical model can reliably be used to distribute the total reaction cross section among the different open channels.

   nucl-exPRC(2016)·18 citations
2. 02*

   Inclusive {\Lambda} production in proton-proton collisions at 3.5 GeV

   J. Adamczewski-Musch🇩🇪 · G. Agakishiev🇷🇺 · O. Arnold🇩🇪 · E.T. Atomssa🇫🇷 · C. Behnke🇩🇪 · J.C. Berger-Chen🇩🇪 · J. Biernat🇵🇱 · A. Blanco🇵🇹 · C. Blume🇩🇪 · M. Böhmer🇩🇪 · P. Bordalo🇵🇹 · S. Chernenko🇷🇺 and 97 other authors

   The inclusive production of {\Lambda} hyperons in proton-proton collisions at $\sqrt{s}$ = 3.18 GeV was measured with HADES at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt. The experimental data are compared to a data-based model for individual exclusive {\Lambda} production channels in the same reaction. The contributions of intermediate resonances such as {\Sigma}(1385), {\Delta}++ or N* are considered in detail. In particular, the result of a partial wave analysis is accounted for the abundant pK${}^{+}${\Lambda} final state. Model and data show a reasonable agreement at mid rapidities, while a difference is found for larger rapidities. A total {\Lambda} production cross section in p+p collisions at $\sqrt{s}$ = 3.18 GeV of {\sigma}(pp $\to$ {\Lambda} + X) = 207.3 $\pm$ 1.3 +6.0 -7.3 (stat.) $\pm$ 8.4 (syst.) +0.4 -0.5 (model) {\mu}b is found.

   nucl-exPRC(2017)·25 citations
3. 03*

   First Measurement of Neutrino Interactions in MicroBooNE

   Pip Hamilton🇺🇸

   The MicroBooNE detector has recently completed its first year of neutrino beam data-taking in the Booster Neutrino Beam at Fermilab, having collected approximately half of its intended data ($3.4\times 10^{20}$ of $6.6\times 10^{20}$ protons on target). We present kinematic distributions of neutrino interactions observed from a small subset of this data (equivalent to $5\times 10^{19}$ protons on target), both as a first step towards a charged-current muon neutrino cross-section on argon, and as an exploration of the capabilities and operational challenges of large liquid argon time projection chambers as neutrino detectors. These distributions have been assessed using fully automated event selection and reconstruction.

   ↳ hep-exnucl-exphysics.ins-det2 citations
4. 04*

   LArIAT: Worlds First Pion-Argon Cross-Section

   Pip Hamilton🇺🇸

   The LArIAT experiment has performed the world's first measurement of the total charged-current pion cross-section on an argon target, using the repurposed ArgoNeuT detector in the Fermilab test beam. Presented here are the results of that measurement, along with an overview of the LArIAT experiment and details of the LArIAT collaboration's plans for future measurements.

   ↳ hep-exnucl-exphysics.ins-det1 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.