Mon·Sep 22, 2014Monday·September 22, 2014

1. 01*

   Tidal Waves in ${}^{102}$Pd: A Phenomenological Analysis

   A.O. Macchiavelli🇺🇸 · A.D. Ayangeakaa🇺🇸 · S. Frauendorf🇺🇸 · U. Garg🇺🇸 · M. A. Caprio🇺🇸

   Rotational and electromagnetic properties of the yrast band in ${}^{102}$Pd are analyzed in terms of a phenomenological phonon model that includes anharmonic terms. Both the moment of inertia and $B(E2)$'s are well reproduced by the model, providing an independent confirmation of the multi-phonon picture recently proposed. The (empirical) dependence of the phonon-phonon interaction on the phonon frequency, in Ru, Pd, and Ru isotopes, follows the expectations from particle-vibration coupling.

   nucl-exnucl-thPRC(2014)·9 citations
2. 02*

   Statistical Methods for Thermonuclear Reaction Rates and Nucleosynthesis Simulations

   Christian Iliadis🇺🇸 · Richard Longland🇪🇸 · Alain Coc🇫🇷 · F. X. Timmes🇺🇸 · Art E. Champagne🇺🇸

   Rigorous statistical methods for estimating thermonuclear reaction rates and nucleosynthesis are becoming increasingly established in nuclear astrophysics. The main challenge being faced is that experimental reaction rates are highly complex quantities derived from a multitude of different measured nuclear parameters (e.g., astrophysical S-factors, resonance energies and strengths, particle and gamma-ray partial widths). We discuss the application of the Monte Carlo method to two distinct, but related, questions. First, given a set of measured nuclear parameters, how can one best estimate the resulting thermonuclear reaction rates and associated uncertainties? Second, given a set of appropriate reaction rates, how can one best estimate the abundances from nucleosynthesis (i.e., reaction network) calculations? The techniques described here provide probability density functions that can be used to derive statistically meaningful reaction rates and final abundances for any desired coverage probability. Examples are given for applications to s-process neutron sources, core-collapse supernovae, classical novae, and big bang nucleosynthesis.

   nucl-exastro-ph.SRJ.Phys.G(2015)·40 citations
3. 03*

   Higher order moments of multiparticle azimuthal correlations

   Ante Bilandzic🇩🇰

   We introduce a general procedure to pave the road towards the ultimate goal of deriving analytic expressions for the probability density functions (p.d.f.'s) of multiparticle azimuthal correlations. All multiparticle azimuthal correlators can be expressed analytically in terms of the real and imaginary parts of $M$-particle $Q$-vectors. We derive the analytic results for the p.d.f.'s of single-particle $Q$-vectors in the most general case and demonstrate that they can be expressed solely in terms of Chebyshev polynomials of the first kind. This leads analytically to the expressions of the characteristic functions of $M$-particle $Q$-vectors in terms of Bessel functions of the first kind. From the obtained characteristics functions we calculate the higher order moments of the real and imaginary parts of $M$-particle $Q$-vectors and use them to obtain the higher order moments of multiparticle azimuthal correlators. Finally, these results are used to investigate the sensitivity of multiparticle azimuthal correlations and to illuminate requirements necessary for future anisotropic flow measurements.

   nucl-exnucl-th4 citations
4. 04*

   Beam Energy Dependence of Dielectron Production in Au+Au Collisions from STAR at RHIC

   Patrick Huck (for the STAR Collaboration)🇨🇳

   We present the energy-dependent study of dielectron production in 0-80% minimum-bias Au+Au collisions at $\sqrt{s_{NN}}$ energies of 19.6, 27, 39, and 62.4 GeV in STAR. Invariant mass ($M_{ee}$) and transverse momentum ($p_T$) differential measurements of dielectron yields are compared to cocktail simulations of known hadronic sources and semi-leptonic charmed decays. The enhancement (excess yield) prominent in the Low-Mass Region (LMR) over the cocktail at all energies, is further compared to calculations of $\rho$ in-medium modifications. Within statistical and systematic uncertainties, we find that the model consistently describes this enhancement from SPS up to top RHIC energies in its $M_{ee}$- as well as $p_T$-dependence. Dielectron measurements drive the statistics for the future BES Phase-II program, which promises to improve our understanding of the LMR enhancement's trend with total baryon densities.

   nucl-exhep-exNPA(2014)·25 citations
5. 05*

   Simulation of the response functions of Extended Range Neutron Multisphere Spectrometer using FLUKA program

   Panfeng Wang🇨🇳 · Yadong Ding🇨🇳 · Qingbin Wang🇨🇳 · Zhongjian Ma🇨🇳 · Siming Guo🇨🇳 · Guanjia Li🇨🇳

   In this paper, the distribution of radiation field in the CSNS spectrometer hall was simulated by FLUKA program. The results showed that the radiation field of high energy proton accelerator is dominated by neutron radiation, and the range of neutron energy is quite widely, including about eleven orders of magnitude. Nextly, work of simulation and calculation of the response functions of four Bonner spheres with simplified model is done by FLUKA and MCNP codes respectively, and the acceptable difference proved the feasibility of FLUKA program in this application and the correctness of the relevant calculation method. Through adopting the actual model, we simulate and calculate the energy response functions of Bonner sphere detectors with polyethylene layers of different diameters, including the detectors with lead layers by using FLUKA code. According to the simulation results, we select eleven detectors as the basic structure of ERNMS.

   ↳ physics.ins-detnucl-exCPC(2015)·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.