Nuclear Theory·nucl-th

Tuesday·December 16, 2014

13 papers—7 primary·6 cross-listed

08
[Submitted on 12 Dec 2014] (cross-list from nucl-ex)
Symmetry energy dependence of long timescale isospin transport
K. Stiefel · Z. Kohley · R. T. deSouza · S. Hudan · K. Hammerton
Isospin transport occurring within dinuclear projectile-like fragments (PLFs) produced in heavy- ion collisions is explored as a probe of the nuclear symmetry energy. Within the framework of the Constrained Molecular Dynamics model (CoMD), the existence of the long-lived dinuclear PLFs, for up to 800 fm/c, is observed. It is demonstrated that changes in the <N/Z> of the two fragments resulting from the breakup of the dinuclear PLF is due to isospin transport. The rate of the transport between the two fragments is shown to be dependent on the slope of the symmetry energy at saturation density. Comparison of the CoMD calculations with experimental data establish that the evolution of <N/Z> could be used to constrain the density dependence of the symmetry energy.
Comments:
Accepted for publication as a Rapid Communication in Physical Review C
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1412.4135 [pdf]
PRC(2014)·17 citations
09
[Submitted on 13 Dec 2014] (cross-list from astro-ph.HE)
Probing Dynamics of Phase Transitions occurring inside a Pulsar
Partha Bagchi🇮🇳 · Arpan Das🇮🇳 · Biswanath Layek🇮🇳 · Ajit M. Srivastava🇮🇳
During the evolution of a pulsar, various phase transitions may occur in its dense interior, such as superfluid transition, as well as transition to various exotic phases of quantum chromodynamics (QCD). We propose a technique which allows to probe these phases and associated transitions by detecting changes in rotation of the star arising from density changes and fluctuations during the transition affecting star's moment of inertia. Our results suggest that these changes may be observable, and may possibly account for glitches and (recently observed) anti-glitches. Accurate measurements of pulsar timing and intensity modulations (arising from wobbling of star due to development of the off-diagonal components of moment of inertia) may be used to pin down the particular phase transition occurring inside the pulsar core. We also discuss the possibility of observing gravitational waves from the changes in the quadrupole moment arising from these rapidly evolving density fluctuations.
Comments:
14 pages, 2 figures
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
1412.4279 [pdf]
Springer Proc.Phys.(2016)·2 citations
10
[Submitted on 13 Dec 2014] (cross-list from hep-ex)
Recent Advances and Open Questions in Neutrino-induced Quasi-elastic Scattering and Single Photon Production
G. T. Garvey🇺🇸 · D. A. Harris🇺🇸 · H. A. Tanaka🇨🇦 · R. Tayloe🇺🇸 · G. P. Zeller🇺🇸
The study of neutrino-nucleus interactions has recently seen rapid development with a new generation of accelerator-based neutrino experiments employing medium and heavy nuclear targets for the study of neutrino oscillations. A few unexpected results in the study of quasi-elastic scattering and single photon production have spurred a revisiting of the underlying nuclear physics and connections to electron-nucleus scattering. A thorough understanding and resolution of these issues is essential for future progress in the study of neutrino oscillations. A recent workshop hosted by the Institute of Nuclear Theory at the University of Washington (INT-13-54W) examined experimental and theoretical developments in neutrino-nucleus interactions and related measurements from electron and pion scattering. We summarize the discussions at the workshop pertaining to the aforementioned issues in quasi-elastic scattering and single photon production, particularly where there was consensus on the highest priority issues to be resolved and the path towards resolving them.
Comments:
75 pages, 43 figures, summary of Institute of Nuclear Theory workshop INT-13-54W discussions
Subjects:
High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1412.4294 [pdf]
Phys.Rept.(2015)·40 citations
11
[Submitted on 15 Dec 2014] (cross-list from hep-ph)
Use of the Husimi distribution for nucleon tomography
Yoshikazu Hagiwara🇯🇵 · Yoshitaka Hatta🇯🇵
In the context of nucleon structure, the Wigner distribution has been commonly used to visualize the phase-space distribution of quarks and gluons inside the nucleon. However, the Wigner distribution does not allow for a probabilistic interpretation because it takes negative values. In pursuit of a positive phase-space distribution in QCD, we introduce the Husimi distribution and demonstrate its advantages via a simple one-loop example. We also comment on a possible connection to the semiclassical approach to saturation physics at small- $x$ .
Comments:
12 pages, 6 figures; improved discussion about the positivity of the Husimi distribution, to be published in Nuclear Physics A
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1412.4591 [pdf]
NPA(2015)·27 citations
12
[Submitted on 15 Dec 2014] (cross-list from hep-lat)
Hadron Structure from Lattice QCD
Jeremy Green🇩🇪
Recent progress in lattice QCD calculations of nucleon structure will be presented. Calculations of nucleon matrix elements and form factors have long been difficult to reconcile with experiment, but with advances in both methodology and computing resources, this situation is improving. Some calculations have produced agreement with experiment for key observables such as the axial charge and electromagnetic form factors, and the improved understanding of systematic errors will help to increase confidence in predictions of unmeasured quantities. The long-omitted disconnected contributions are now seeing considerable attention and some recent calculations of them will be discussed.
Comments:
12 pages, 7 figures. Review talk presented at the XIth Quark Confinement and the Hadron Spectrum, September 8-12, 2014, Saint Petersburg, Russia
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1412.4637 [pdf]
AIP Conf.Proc.(2016)·13 citations
13
[Submitted on 15 Dec 2014] (cross-list from nucl-ex)
Limitation of multi-particle correlations for studying the event-by-event distribution of harmonic flow in heavy-ion collisions
Jiangyong Jia🇺🇸 · Sooraj Krishnann🇺🇸
The sensitivity of flow harmonics from cumulants on the event-by-event flow distribution $p (v_{n})$ is investigated using a simple central moment expansion approach. For narrow distribution whose width is much smaller than the mean $σ_{n} ≪< v_{n} >$ , the difference between the first three higher-order cumulant estimates $v_{n} {4}$ , $v_{n} {6}$ and $v_{n} {8}$ are not very sensitive to the shape of $p (v_{n})$ . For broad distribution $σ_{n} ≳ < v_{n} >$ , the higher-order cumulant estimates differ from each other but may change sign and become ill-defined. This sign change arises from the choice of $p (v_{n})$ , without the need to invoke non-flow effects. Direct extraction of $p (v_{n})$ via a data-driven unfolding method is a more preferred approach for flow distribution measurement.
Comments:
9 pages, 3 figures, replaced with published version
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1412.4759 [pdf]
PRC(2015)·18 citations

Affiliations

first authorsco-authorsvia INSPIRE

Symmetry energy dependence of long timescale isospin transport

Probing Dynamics of Phase Transitions occurring inside a Pulsar

Recent Advances and Open Questions in Neutrino-induced Quasi-elastic Scattering and Single Photon Production

Use of the Husimi distribution for nucleon tomography

Hadron Structure from Lattice QCD

Limitation of multi-particle correlations for studying the event-by-event distribution of harmonic flow in heavy-ion collisions

Affiliations