Nuclear Theory·nucl-th

Thursday·May 21, 2015

9 papers—4 primary·5 cross-listed

01
[Submitted on 20 May 2015]
Nuclear dynamics induced by antiprotons
Zhao-Qing Feng🇨🇳
Reaction dynamics in collisions of antiprotons on nuclei is investigated within the Lanzhou quantum molecular dynamics model. The reaction channels of elastic scattering, annihilation, charge exchange and inelastic collisions of antiprotons on nucleons have been included in the model. Dynamics on particle production, in particular pions, kaons, antikaons and hyperons, is investigated in collisions of $p$ on $^{12}$ C, $^{20}$ Ne, $^{40}$ Ca and $^{181}$ Ta from a low to high incident momenta. It is found that the annihilations of $p$ on nucleons are of importance on the dynamics of particle production in phase space. Hyperons are mainly produced via meson induced reactions on nucleons and strangeness exchange collisions, which lead to the delayed emission in antiproton-nucleus collisions.
Comments:
8 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:1405.1997
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1505.05260 [pdf]
Nucl.Sci.Tech.(2015)·6 citations
02
[Submitted on 20 May 2015]
Effects of chiral imbalance and magnetic field on pion superfluidity and color superconductivity
Gaoqing Cao🇨🇳 · Pengfei Zhuang🇨🇳
The effects of chiral imbalance and external magnetic field on pion superfluidity and color superconductivity are investigated in extended Nambu--Jona-Lasinio models. We take Schwinger approach to treat the interaction between charged pion condensate and magnetic field at finite isospin density and include simultaneously the chiral imbalance and magnetic field at finite baryon density. For the superfluidity, the chiral imbalance and magnetic field lead to catalysis and inverse catalysis effects, respectively. For the superconductivity, the chiral imbalance enhances the critical baryon density, and the magnetic field results in a de Haas--van Alphan oscillation on the phase transition line.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1505.05307 [pdf]
PRD(2015)·63 citations
03
[Submitted on 20 May 2015]
Understanding the structure of $d^{*} (2380)$ in chiral quark model
F. Huang🇨🇳 · P. N. Shen🇨🇳 · Y. B. Dong🇨🇳 · Z. Y. Zhang🇨🇳
The structure and decay properties of $d^{*}$ have been detailedly investigated in both the chiral SU(3) quark model and the extended chiral SU(3) quark model that describe the energies of baryon ground states and the nucleon-nucleon (NN) scattering data satisfactorily. By performing a dynamical coupled-channels study of the system of $ΔΔ$ and hidden-color channel (CC) with quantum numbers $I (J^{P}) = 0 (3^{+})$ in the framework of the resonating group method (RGM), we find that the $d^{*}$ has a mass of about $2.38 - 2.42$ GeV and a root-mean-square radius (RMS) of about $0.76 - 0.88$ fm. The channel wave function is extracted by a projection of the RGM wave function onto the physical basis, and the fraction of CC component in the $d^{*}$ is found to be about $66% - 68%$ , which indicates that the $d^{*}$ is a hexaquark-dominated exotic state. Based on this scenario the partial decay widths of $d^{*} \to d π^{0} π^{0}$ and $d^{*} \to d π^{+} π^{-}$ are further explicitly evaluated and the total width is then obtained by use of the branching ratios extracted from the measured cross sections of other possible decay channels. Both the mass and the decay width of $d^{*}$ calculated in this work are compatible with the data ( $M \approx 2380$ MeV, $Γ \approx 70$ MeV) reported by WASA-at-COSY Collaboration.
Comments:
9 pages, 2 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1505.05395 [pdf]
SCPMA(2016)·39 citations
04
[Submitted on 20 May 2015]
Scaling violation and relativistic effective mass from quasielastic electron scattering: implications for neutrino reactions
J.E. Amaro🇪🇸 · E. Ruiz Arriola🇪🇸 · I. Ruiz Simo🇪🇸
The experimental data from quasielastic electron scattering from $^{12}$ C are reanalyzed in terms of a new scaling variable suggested by the interacting relativistic Fermi gas with scalar and vector interactions, which is known to generate a relativistic effective mass for the interacting nucleons. By choosing a mean value of this relativistic effective mass $m_{N}^{*} = 0.8 m_{N}$ , we observe that most of the data fall inside a region around the inverse parabola-shaped universal scaling function of the relativistic Fermi gas. This suggests a method to select the subset of data that highlight the quasielastic region, about two thirds of the total 2,500 data. Regardless of the momentum and energy transfer, this method automatically excludes the data that are not dominated by the quasielastic process. The resulting band of data reflects deviations from the perfect universality, and can be used to characterize experimentally the quasielastic peak, despite the manifest scaling violation. Moreover we show that the spread of the data around the scaling function can be interpreted as genuine fluctuations of the effective mass $M^{*} \equiv m_{N}^{*} / m_{N} \sim 0.8 \pm 0.1$ . Applying the same procedure we transport the scaling quasielastic band into a theoretical prediction band for neutrino scattering cross section that is compatible with the recent measurements and slightly more accurate.
Comments:
5 pages, 3 figures. Updated version as accepted for publication. Small updates to text, corrected some errors in equations and figure labels
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1505.05415 [pdf]
PRC(2015)·21 citations

Affiliations

first authorsco-authorsvia INSPIRE

Nuclear dynamics induced by antiprotons

Effects of chiral imbalance and magnetic field on pion superfluidity and color superconductivity

Understanding the structure of d∗(2380) in chiral quark model

Scaling violation and relativistic effective mass from quasielastic electron scattering: implications for neutrino reactions

Affiliations

Understanding the structure of $d^{*} (2380)$ in chiral quark model