Nuclear Theory·nucl-th

Monday·February 8, 2016

6 papers—2 primary·4 cross-listed

01
[Submitted on 5 Feb 2016]
Rotational Properties of the Odd- $Z$ Transfermium Nucleus $^{255}$ Lr by a Particle-number-conserving Method in the Cranked Shell Model
Yu-Chun Li🇨🇳 · Xiao-Tao He🇨🇳
Experimentally observed ground state band based on the $1/ 2^{-} [521]$ Nilsson state and the first exited band based on the $7/ 2^{-} [514]$ Nilsson state in the odd- $Z$ nucleus $^{255}$ Lr are studied by the cranked shell model (CSM) with the paring correlations treated by the particle-number-conserving (PNC) method. This is the first time the detailed theoretical investigations being performed on these rotational bands. Both the experimental kinematic and dynamic moment of inertia ( $J^{(1)}$ and $J^{(2)}$ ) versus rotational frequency are reproduced quite well by the PNC-CSM calculations. By comparing the theoretical kinematic moment of inertia $J^{(1)}$ with the experimental ones extracted from different spin assignments, the spin $17/ 2^{-} \to 13/ 2^{-}$ is assigned to the lowest-lying $196.6 (5)$ keV transition of the $1/ 2^{-} [521]$ band, and $15/ 2^{-} \to 11/ 2^{-}$ to the $189 (1)$ keV transition of the $7/ 2^{-} [514]$ band, respectively. The proton $N = 7$ major shell is included in the calculations. The intruder of the high $- j$ low $- Ω$ orbitals $1 j_{15/2}$ $(1/ 2^{-} [770])$ at the high spin leads to the band-crossing at $ℏ ω \approx 0.20$ ( $ℏ ω \approx 0.25$ ) MeV for the $7/ 2^{-} [514]$ $α = - 1/2$ ( $α = + 1/2$ ) band, and at $ℏ ω \approx 0.175$ MeV for the $1/ 2^{-} [521]$ $α = - 1/2$ band, respectively. Further investigations show that the band-crossing frequencies are quadrupole deformation dependent.
Comments:
arXiv admin note: text overlap with arXiv:1208.1156 by other authors
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1602.01933 [pdf]
SCPMA(2016)·12 citations
02
[Submitted on 5 Feb 2016]
High order flow harmonics of identified hadrons in 2.76 A TeV Pb+Pb collisions
Hao-jie Xu🇨🇳 · Zhuopeng Li🇨🇳 · Huichao Song🇨🇳
Using iEBE-VISHNU hybrid model with the AMPT initial conditions, we study the higher order flow harmonics of identified hadrons in 2.76 A TeV Pb+Pb collisions. Comparison with the recent ALICE measurements at 20-30\% centrality shows that our calculations nicely describe the data below 2 GeV, especially for the $v_{2}$ , $v_{3}$ and $v_{4}$ mass-orderings among pions, kaons and protons. We also extended the calculations to other centrality bins, which presents similar mass-ordering patterns for these flow harmonics as the ones observed at 20-30\% centrality. In the later part of this article, we explore the development of $v_{n}$ mass ordering/splitting during the hadronic evolution through the comparison runs from iEBE-VISHNU hybrid model and pure hydrodynamics with different decoupling temperatures.
Comments:
7 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1602.02029 [pdf]
PRC(2016)·60 citations
03
[Submitted on 4 Feb 2016] (cross-list from astro-ph.HE)
Thermal conductivity and impurity scattering in the accreting neutron star crust
Alessandro Roggero · Sanjay Reddy
We calculate the thermal conductivity of electrons for the strongly correlated multi-component ion plasma expected in the outer layers of neutron star's crust employing a Path Integral Monte Carlo (PIMC) approach. This allows us to isolate the low energy response of the ions and use it to calculate the electron scattering rate and the electron thermal conductivity. We find that the scattering rate is enhanced by a factor 2-4 compared to earlier calculations based on the simpler electron-impurity scattering formalism. This findings directly impacts the interpretation of thermal relaxation observed in transiently accreting neutron stars and has implications for the composition and nuclear reactions in the crust that occur during accretion.
Comments:
Revised version addressing referee comments
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
1602.01831 [pdf]
PRC(2016)·25 citations
04
[Submitted on 5 Feb 2016] (cross-list from hep-ph)
Reply to "Comment on `Breakdown of the expansion of finite-size corrections to the hydrogen Lamb shift in moments of charge distribution'"
Franziska Hagelstein🇩🇪 · Vladimir Pascalutsa (KPH, JGU Mainz)🇩🇪
To comply with the critique of the Comment [J. Arrington, arXiv:1602.01461], we consider another modification of the proton electric form factor, which resolves the "proton-radius puzzle". The proposed modification satisfies all the consistency criteria put forward in the Comment, and yet has a similar impact on the puzzle as that of the original paper. Contrary to the concluding statement of the Comment, it is not difficult to find an ad hoc modification of the form factor at low $Q$ that resolves the discrepancy and is consistent with analyticity constraints. We emphasize once again that we do not consider such an ad hoc modification of the proton form factor to be a solution of the puzzle until a physical mechanism for it is found.
Comments:
3 pages, 3 figures, 1 table, to appear in Phys. Rev. A, corrected typo in caption of fig. 1
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
arXiv:
1602.01978 [pdf]
PRA(2016)·2 citations
05
[Submitted on 5 Feb 2016] (cross-list from hep-ph)
PDFs from nucleons to nuclei
Alberto Accardi🇺🇸
I review recent progress in the extraction of unpolarized parton distributions in the proton and in nuclei from a unified point of view that highlights how the interplay between high energy particle physics and lower energy nuclear physics can be of mutual benefit to either field. Areas of overlap range from the search for physics beyond the standard model at the LHC, to the study of the non perturbative structure of nucleons and the emergence of nuclei from quark and gluon degrees of freedom, to the interaction of colored probes in a cold nuclear medium.
Comments:
Pleanary talk delivered at DIS 2015, Dallas, TX (USA), 27 April - May 1 2015
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1602.02035 [pdf]
PoS(2015)·14 citations
06
[Submitted on 5 Feb 2016] (cross-list from hep-ph)
On the uncertainty estimates of the $σ$ -pole determination by Padé approximants
Irinel Caprini🇷🇴 · Pere Masjuan🇩🇪 · Jacobo Ruiz de Elvira🇩🇪 · Juan José Sanz-Cillero🇪🇸
We discuss the determination of the $f_{0} (500)$ (or $σ$ ) resonance by analytic continuation through Padé approximants of the $π π$ -scattering amplitude from the physical region to the pole in the complex energy plane. The aim is to analyze the uncertainties of the method, having in view the fact that analytic continuation is an ill-posed problem in the sense of Hadamard. Using as input a class of admissible parameterizations of the scalar-isoscalar $π π$ partial wave, which satisfy with great accuracy the same set of dispersive constraints, we find that the Roy-type integral representations lead to almost identical pole positions for all of them, while the predictions of the Padé approximants have a larger spread, being sensitive to features of the input parameterization that are not controlled by the dispersive constraints. Our conservative conclusion is that the $σ$ -pole determination by Padé approximants is consistent with the prediction of Roy-type equations, but has an uncertainty almost a factor two larger.
Comments:
11 pages, 13 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1602.02062 [pdf]
PRD(2016)·43 citations

Affiliations

first authorsco-authorsvia INSPIRE

Rotational Properties of the Odd-Z Transfermium Nucleus 255Lr by a Particle-number-conserving Method in the Cranked Shell Model

High order flow harmonics of identified hadrons in 2.76 A TeV Pb+Pb collisions

Thermal conductivity and impurity scattering in the accreting neutron star crust

Reply to "Comment on `Breakdown of the expansion of finite-size corrections to the hydrogen Lamb shift in moments of charge distribution'"

PDFs from nucleons to nuclei

On the uncertainty estimates of the σ-pole determination by Padé approximants

Affiliations

Rotational Properties of the Odd- $Z$ Transfermium Nucleus $^{255}$ Lr by a Particle-number-conserving Method in the Cranked Shell Model

On the uncertainty estimates of the $σ$ -pole determination by Padé approximants