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Nuclear Theory·nucl-th

Thursday·February 7, 2019

5 papers—3 primary·2 cross-listed

All5Primary3Cross-lists2
  1. 01

    Thick-Restart Block Lanczos Method for Large-Scale Shell-Model Calculations

    Noritaka Shimizu · Takahiro Mizusaki · Yutaka Utsuno · Yusuke Tsunoda

    We propose a thick-restart block Lanczos method, which is an extension of the thick-restart Lanczos method with the block algorithm, as an eigensolver of the large-scale shell-model calculations. This method has two advantages over the conventional Lanczos method: the precise computations of the near-degenerate eigenvalues, and the efficient computations for obtaining a large number of eigenvalues. These features are quite advantageous to compute highly excited states where the eigenvalue density is rather high. A shell-model code, named KSHELL, equipped with this method was developed for massively parallel computations, and it enables us to reveal nuclear statistical properties which are intensively investigated by recent experimental facilities. We describe the algorithm and performance of the KSHELL code and demonstrate that the present method outperforms the conventional Lanczos method.

    nucl-thphysics.comp-phComput.Phys.Commun.(2019)·400 citations
  2. 02

    Effects of drag induced radiation and multi-stage evolution on heavy quark energy loss

    Abhijit Majumder🇺🇸 · Shanshan Cao🇺🇸 · Chun Shen🇺🇸 · Guang-You Qin🇨🇳

    Heavy quarks serve as ideal probes of the QGP properties produced in energetic nuclear collisions, and provide a unique opportunity to study the mass effects on parton energy loss. We develop a multi-stage approach for heavy quark evolution inside the QGP, in which heavy quarks first undergo a rare-scattering multiple-emission evolution at momenta large compared to their mass (sensitive only to the transverse diffusion coefficient ), and then evolve through a single-scattering induced emission (Gunion-Bertsch) stage at momenta comparable to their mass [sensitive to not only , but also the longitudinal drag and diffusion coefficients]. This multi-stage approach is coupled to a (2+1)-D viscous hydrodynamic model for a quantitative investigation of charm vs. beauty quark energy loss inside the QGP. Based on this approach, we find that drag induced radiation has a considerable impact on the energy loss of intermediate massive beauty quarks. This effect increases the suppression of B mesons and narrows the difference between the of B and D mesons. Our results are consistent with the experimental data at the LHC and contribute to a more quantitative understanding of the transverse momentum dependence of the mass hierarchy of parton energy loss inside the QGP.

    nucl-thhep-phPoS(2019)·0 citations
  3. 03

    Complex-energy analysis of proton-proton fusion

    David Gaspard · Jean-Marc Sparenberg · Quentin Wenda · Daniel Baye

    An analysis of the astrophysical factor of the proton-proton weak capture () is performed on a large energy range covering solar-core and early Universe temperatures. The measurement of being physically unachievable, its value relies on the theoretical calculation of the matrix element . Surprisingly, reaches a maximum near that has been unexplained until now. A model-independent parametrization of valid up to about is established on the basis of recent effective-range functions. It provides an insight into the relationship between the maximum of and the proton-proton resonance pole at from analytic continuation. In addition, this parametrization leads to an accurate evaluation of the derivatives of , and hence of , in the limit of zero energy.

    nucl-thPRC(2019)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE