Fri·Jul 1, 2016Friday·July 1, 2016

1. 01*

   Search for Perturbations of Nuclear Decay Rates Induced by Reactor Electron Antineutrinos

   V. E. Barnes🇺🇸 · D. J. Bernstein · C. D. Bryan🇺🇸 · N. Cinko🇺🇸 · G. G. Deichert🇺🇸 · J. T. Gruenwald · J. M. Heim🇺🇸 · H. B. Kaplan🇺🇸 · R. LaZur · D. Neff🇺🇸 · J. M. Nistor🇺🇸 · N. Sahelijo · E. Fischbach🇺🇸

   We report the results of an experiment conducted near the High Flux Isotope Reactor of Oak Ridge National Laboratory, designed to address the question of whether a flux of reactor-generated electron antineutrinos can alter the rates of weak nuclear interaction-induced decays for Mn-54, Na-22, and Co-60. This experiment, while quite sensitive, cannot exclude perturbations less than one or two parts in $10^4$ in $\beta$ decay (or electron capture) processes, in the presence of an antineutrino flux of $3\times 10^{12}$ cm${}^{-2}$ s${}^{-1}$. The present experimental methods are applicable to a wide range of isotopes. Improved sensitivity in future experiments may be possible if we can understand and reduce the dominant systematic uncertainties.

   nucl-exphysics.ins-det3 citations
2. 02*

   The 7Be(n,alpha)4He reaction and the Cosmological Lithium Problem: measurement of the cross section in a wide energy range at n_TOF (CERN)

   M. Barbagallo · A. Musumarra · L. Cosentino · E. Maugeri · S. Heinitz · A. Mengoni · R. Dressler · D. Schumann · F. Kaeppeler · N. Colonna · P. Finocchiaro · M. Ayranov and 3 other authors

   The energy-dependent cross section of the 7Be(n,alpha)4He reaction, of interest for the so-called Cosmological Lithium Problem in Big Bang Nucleosynthesis, has been measured for the first time from 10 meV to 10 keV neutron energy. The challenges posed by the short half-life of 7Be and by the low reaction cross section have been overcome at n_TOF thanks to an unprecedented combination of the extremely high luminosity and good resolution of the neutron beam in the new experimental area (EAR2) of the n_TOF facility at CERN, the availability of a sufficient amount of chemically pure 7Be, and a specifically designed experimental setup. Coincidences between the two alpha-particles have been recorded in two Si-7Be-Si arrays placed directly in the neutron beam. The present results are consistent, at thermal neutron energy, with the only previous measurement performed in the 60's at a nuclear reactor. The energy dependence here reported clearly indicates the inadequacy of the cross section estimates currently used in BBN calculations. Although new measurements at higher neutron energy may still be needed, the n_TOF results hint to a minor role of this reaction in BBN, leaving the long-standing Cosmological Lithium problem unsolved.

   nucl-exPRL(2016)·108 citations
3. 03*

   Probing transfer to unbound states of the ejectile with weakly bound 7Li on 93Nb

   S. K. Pandit🇮🇳 · A. Shrivastava🇮🇳 · K. Mahata🇮🇳 · N. Keeley🇫🇷 · V. V. Parkar🇮🇳 · P. C. Rout🇮🇳 · I. Martel🇪🇸 · C. S. Palshetkar🇮🇳 · A. Kumar🇮🇳 · K. Ramachandran🇮🇳 · P. Patale · A. Chatterjee🇮🇳 · S. Kailas🇮🇳

   The two-step process of transfer followed by breakup is explored by measuring a rather complete set of exclusive data for reaction channels populating states in the ejectile continua of the ${}^7$Li+${}^{93}$Nb system at energies close to the Coulomb barrier. The cross sections for $\alpha +\alpha$ events from one proton pickup were found to be smaller than those for $\alpha +d$ events from one neutron stripping and $\alpha +t$ events from direct breakup of ${}^7$Li. Coupled channels Born approximation and continuum discretized coupled channels calculations describe the data well and support the conclusion that the $\alpha +d$ and $\alpha +\alpha$ events are produced by direct transfer to unbound states of the ejectile.

   nucl-exnucl-thPRC(2016)·35 citations
4. 04*

   Diagonal and off-diagonal susceptibilities of conserved quantities in relativistic heavy-ion collisions

   Arghya Chatterjee🇮🇳 · Sandeep Chatterjee🇮🇳 · Tapan K. Nayak🇮🇳 · Nihar Ranjan Sahoo🇺🇸

   Susceptibilities of conserved quantities, such as baryon number, strangeness and electric charge are sensitive to the onset of quantum chromodynamics (QCD) phase transition and are expected to provide information on the matter produced in heavy-ion collision experiments. A comprehensive study of the second-order diagonal susceptibilities and cross correlations has been made within a thermal model approach of the hadron resonance gas (HRG) model as well as with a hadronic transport model, UrQMD. We perform a detailed analysis of the effect of detector acceptances and choice of particle species in the experimental measurements of the susceptibilities for heavy-ion collisions corresponding to \sNN = 4 GeV to 200 GeV. The transverse momentum cutoff dependence of suitably normalised susceptibilities are proposed as useful observables to probe the properties of the medium at freezeout.

   nucl-exhep-exhep-phnucl-thJ.Phys.G(2016)·25 citations
5. 05*

   On the Equivalence of Experimental B(E2) Values Determined by Various Techniques

   M. Birch🇨🇦 · B. Pritychenko🇺🇸 · B. Singh🇨🇦

   We establish the equivalence of the various techniques for measuring B(E2) values using a statistical analysis. Data used in this work come from the re- cent compilation by B. Pritychenko et al., At. Data Nucl. Data Tables 107 (2016). We consider only those nuclei for which the B(E2) values were measured by at least two different methods, with each method being independently performed at least twice. Our results indicate that most prevalent methods of measuring B(E2) values are equivalent, with some weak evidence that Doppler-shift attenuation method (DSAM) measurements may differ from Coulomb excitation (CE) and nuclear resonance fuorescence (NRF) measurements. However, such an evidence appears to arise from discrepant DSAM measurements of the lifetimes for 60Ni and some Sn nuclei rather than a systematic deviation in the method itself.

   nucl-exNPA(2016)·3 citations
6. 06*

   (Anti-)deuteron production and anisotropic flow measured with ALICE at the LHC

   Ramona Lea (for the ALICE Collaboration)🇮🇹

   The high abundance of (anti-)deuterons in the statistics gathered in Run 1 of the LHC and the excellent performance of the ALICE setup allow for the simultaneous measurement of the elliptic flow and the deuteron production rates with a large transverse momentum ($p_{\mathrm{T}}$) reach. The (anti-) deuterons are identified using the specific energy loss in the time projection chamber and the velocity information in the time-of-flight detector. The elliptic flow of (anti-)deuterons can provide insight into the production mechanisms of particles in heavy-ion collisions. Quark coalescence is one of the approaches to describe the elliptic flow of hadrons, while the production of light nuclei can be also depicted as a coalescence of nucleons. In these proceedings, the measured $v_2$ of deuterons produced in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}$=2.76TeV will be compared to expectations from coalescence and hydrodynamic models.

   ↳ hep-exnucl-exNPA(2016)·3 citations
7. 07*

   Negative and nonlinear magnetoresistance effect in silicon strip

   Fangcong Wang🇨🇳 · Haixia Li🇨🇳 · Hui Guo · Xiaolong Fan · Zhankui Li🇨🇳

   Both negative magnetoresistance and nonlinear magnetoresisitance were observed in silicon strip nuclear radiation detector in room temperature if we applied high magnetic field intensity in different direction. This result is different with former report. We believe this is the result of coaction of high electric field (Gunn effect) and high magnetic field, or because of the variation of number of carriers and the carriers mobility. The weak localization and Landau energy levels also affect the magnetoresistance. Different crystal orientations have different energy band structures. Complex band structures lead complex carriers mobility plus Landau energy levels. So the magnetoresisitance effect is anisotropy.

   ↳ physics.ins-detnucl-ex0 citations
8. 08*

   Hadronic EDM and New physics beyond standard model

   Nodoka Yamanaka🇯🇵

   The nuclear electric dipole moment is a very sensitive probe of CP violation beyond the standard model, and for light nuclei, it can be evaluated accurately using the few-body calculational methods. In this talk, we present the result of the evaluation of the electric dipole moment of 3-body and 4-body systems using the Gaussian expansion method in the ab initio approach and in the cluster model. We also give the future prospects for the discovery of new physics beyond it within the sensitivity of prepared experiments.

   ↳ nucl-thhep-exhep-phnucl-exJPS Conf.Proc.(2017)·0 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.