Nuclear Theory·nucl-th

Thursday·January 8, 2015

7 papers—3 primary·4 cross-listed

01
[Submitted on 7 Jan 2015]
Half-lives of Double $β^{+}$ -decay with Two Neutrinos
Yuejiao Ren🇨🇳 · Zhongzhou Ren🇨🇳
Nuclear double $β^{-}$ -decays with two neutrinos were observed for many years and a systematic law describing the relation between their half-lives and decay energies was also proposed recently [Phys. Rev. C89, 064603 (2014)]. However, double $β^{+}$ -decay ( $β^{+} β^{+})$ with emission of both two positrons and two neutrinos has not been observed up to date. In this article, we perform a systematic analysis on the candidates of double $β^{+}$ -decay, based on the 2012 nuclear mass table. Eight nuclei are found to be the good candidates for double $β^{+}$ -decay and their half-lives are predicted according to the generalization of the systematic law to double $β^{+}$ -decay. As far as we know, there is no theoretical result on double $β^{+}$ -decay of nucleus $^{154} D y$ and our result is the first prediction on this nucleus. This is also the first complete research on eight double $β^{+}$ -decay candidates based on the available data of nuclear masses. It is expected that the calculated half-lives of double $β^{+}$ -decay in this article will be useful for future experimental search of double $β^{+}$ -decay.
Comments:
9 pages,1 figure,2 tables
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1501.01374 [pdf]
SCPMA(2015)·5 citations
02
[Submitted on 7 Jan 2015]
A new shock-capturing numerical scheme for ideal hydrodynamics
Zuzana Feckova · Boris Tomasik
We present a new algorithm for solving ideal relativistic hydrodynamics based on Godunov method with an exact solution of Riemann problem for an arbitrary equation of state. Standard numerical tests are executed, such as the sound wave propagation and the shock tube problem. Low numerical viscosity and high precision are attained with proper discretization.
Comments:
Proceedings of Hot Quarks 2014
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1501.01411 [pdf]
J.Phys.Conf.Ser.(2015)·0 citations
03
[Submitted on 7 Jan 2015]
De-Confinement and Clustering of Color Sources in Nuclear Collisions
M. A. Braun🇷🇺 · J. Dias de Deus🇵🇹 · A. S. Hirsch🇺🇸 · C. Pajares🇪🇸 · R. P. Scharenberg🇺🇸 · B. K. Srivastava🇺🇸
A brief introduction of the relationship of string percolation to the Quantum Chromo Dynamics (QCD) phase diagram is presented. The behavior of the Polyakov loop close to the critical temperature is studied in terms of the color fields inside the clusters of overlapping strings, which are produced in high energy hadronic collisions. The non-Abelian nature of the color fields implies an enhancement of the transverse momentum and a suppression of the multiplicities relative to the non overlapping case. The prediction of this framework are compared with experimental results from the SPS, RHIC and LHC for $pp$ and AA collisions. Rapidity distributions, probability distributions of transverse momentum and multiplicities, Bose-Einstein correlations, elliptic flow and ridge structures are used to evaluate these comparison. The thermodynamical quantities, the temperature, and energy density derived from RHIC and LHC data and Color String Percolation Model (CSPM) are used to obtain the shear viscosity to entropy density ratio ( $η / s$ ). It was observed that the inverse of ( $η / s$ ) represents the trace anomaly $Δ = (ε - 3 P) / T^{4}$ . Thus the percolation approach within CSPM can be successfully used to describe the initial stages in high energy heavy ion collisions in the soft region in high energy heavy ion collisions. The thermodynamical quantities, temperature and the equation of state are in agreement with the lattice QCD calculations. Thus the clustering of color sources has a clear physical basis although it cannot be deduced directly from QCD.
Comments:
107 pages, 37 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1501.01524 [pdf]
Phys.Rept.(2015)·84 citations

Affiliations

first authorsco-authorsvia INSPIRE

Half-lives of Double β+-decay with Two Neutrinos

A new shock-capturing numerical scheme for ideal hydrodynamics

De-Confinement and Clustering of Color Sources in Nuclear Collisions

Affiliations

Half-lives of Double $β^{+}$ -decay with Two Neutrinos