Nuclear Theory·nucl-th

Monday·January 27, 2020

16 papers—7 primary·9 cross-listed

08
[Submitted on 23 Jan 2020] (cross-list from hep-lat)
Skewness, kurtosis and the 5th and 6th order cumulants of net baryon-number distributions from lattice QCD confront high-statistics STAR data
A. Bazavov🇺🇸 · D. Bollweg🇩🇪 · H.-T. Ding🇨🇳 · P. Enns🇩🇪 · J. Goswami🇩🇪 · P. Hegde🇮🇳 · O. Kaczmarek🇨🇳 · F. Karsch🇩🇪 · R. Larsen🇺🇸 · Swagato Mukherjee🇺🇸 · H. Ohno🇯🇵 · P. Petreczky🇺🇸 and 3 other authors
We present new results on up to $6^{t h}$ order cumulants of net baryon-number fluctuations at small values of the baryon chemical potential, $μ_{B}$ , obtained in lattice QCD calculations with physical values of light and strange quark masses. Representation of the Taylor expansions of higher order cumulants in terms of the ratio of the two lowest order cumulants, $M_{B} / σ_{B}^{2} = χ_{1}^{B} (T, μ_{B}) / χ_{2}^{B} (T, μ_{B})$ , allows for a parameter free comparison with data on net proton-number cumulants obtained by the STAR Collaboration in the Beam Energy Scan at RHIC. We show that recent high statistics data on skewness and kurtosis ratios of net proton-number distributions, obtained at beam energy $s_{_{N N}} = 54.4$ GeV, agree well with lattice QCD results on cumulants of net baryon-number fluctuations close to the pseudo-critical temperature, $T_{p c} (μ_{B})$ , for the chiral transition in QCD. We also present first results from a next-to-leading order expansion of $5^{t h}$ and $6^{t h}$ order cumulants on the line of pseudo-critical temperatures.
Comments:
13 pages, 11 figures, minor corrections and updates of references
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2001.08530 [pdf]
PRD(2020)·211 citations
09
[Submitted on 23 Jan 2020] (cross-list from astro-ph.HE)
Characterizing $r$ -Process Sites through Actinide Production
Erika M. Holmbeck · Rebecca Surman · Anna Frebel · G. C. McLaughlin · Matthew R. Mumpower · Trevor M. Sprouse · Toshihiko Kawano · Nicole Vassh · Timothy C. Beers
Of the variations in the elemental abundance patterns of stars enhanced with $r$ -process elements, the variation in the relative actinide-to-lanthanide ratio is among the most significant. We investigate the source of these actinide differences in order to determine whether these variations are due to natural differences in astrophysical sites, or due to the uncertain nuclear properties that are accessed in $r$ -process sites. We find that variations between relative stellar actinide abundances is most likely astrophysical in nature, owing to how neutron-rich the ejecta from an $r$ -process event may be. Furthermore, if an $r$ -process site is capable of generating variations in the neutron-richness of its ejected material, then only one type of $r$ -process site is needed to explain all levels of observed relative actinide enhancements.
Comments:
12 pages, 5 figures, NPA-IX proceedings
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2001.08792 [pdf]
J.Phys.Conf.Ser.(2020)·3 citations
10
[Submitted on 24 Jan 2020] (cross-list from hep-ph)
Comparative analysis of $ω p$ , $ϕp$ , and $J / ψ p$ scattering lengths from A2, CLAS, and GlueX threshold measurements
Igor Strakovsky (GWU)🇺🇸 · Lubomir Pentchev (JLab)🇺🇸 · Alexander Titov (JINR)🇷🇺
The high accuracy $ϕ$ -meson photoproduction data from the CLAS experiment in Hall~B of Jefferson Laboratory allow us to determine the near-threshold total cross section of the $γ p \to ϕp$ reaction and use it for evaluating the $ϕp$ scattering length $α_{ϕp}$ . These data result in an absolute value of $∣ α_{ϕp} ∣ = (0.063 \pm 0.010)$ ~fm, which is smaller than the typical hadron size. A comparative analysis of $α_{ϕp}$ with the previously determined scattering lengths for $ω p$ and $J / ψ p$ from the A2 and GlueX experiments is performed.
Comments:
5 pages, 2 figures, 1 figure added
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2001.08851 [pdf]
PRC(2020)·56 citations
11
[Submitted on 14 Jan 2020] (cross-list from hep-ph)
Role of interaction on electrical conductivity of QGP in presence of magnetic field
Ankita Mishra🇮🇳 · Souvik Paul🇮🇳 · Jayanta Dey🇮🇳 · Sarthak Satapathy🇮🇳 · Sabyasachi Ghosh🇮🇳
Effect of quantum chromodynamics (QCD) interaction in quark-gluon plasma on electrical conductivity is studied, where lattice quantum chromodynamics (LQCD) results are mapped through quark and gluon degeneracy.
Comments:
Conference proceeding in 64th DAE-BRNS Symposium on Nuclear Physics, Link- http://sympnp.org/snp2019/
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2001.08990 [pdf]
DAE Symp.Nucl.Phys.(2019)·0 citations
12
[Submitted on 14 Jan 2020] (cross-list from hep-ph)
Causal aspects of effective QCD models
Jayanta Dey🇮🇳 · Sabyasachi Ghosh🇮🇳 · Chowdhury Aminul Islam🇮🇳
Here we studied the possible diffusion speed for relativistic fluid in different effective quantum chromodynamics models: Nambu-Jona-Lasinio (NJL), Polyakov loop extended NJL, entangled PNJL (EPNJL) model.
Comments:
Conference proceeding in 64th DAE-BRNS Symposium on Nuclear Physics, Link- http://sympnp.org/snp2019/
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2001.08991 [pdf]
DAE Symp.Nucl.Phys.(2019)·0 citations
13
[Submitted on 23 Jan 2020] (cross-list from nucl-ex)
Deuteron-induced reactions on manganese at low energies
M. Avrigeanu · E. Simeckova · U. Fischer · J. Mrazek · J. Novak · M. Stefanik · C. Costache · V. Avrigeanu
The scarce data systematics and complexity of deuteron interactions demand the update of both the experimental database and theoretical frame of deuteron activation cross sections. Various reactions induced by neutrons and protons following the deuteron breakup (BU) should be also taken into account. On the other hand, deuteron reaction cross sections recommended recently for high-priority elements are still based on data fit without predictive power. Purpose: Accurate new measurements of low-energy deuteron-induced reaction cross sections for monoisotopic (55Mn) natural manganese target enhance the related database as well as the opportunity of an unitary and consistent account of the related reaction mechanisms. Method: Activation cross sections of 54,56Mn, and 51Cr nuclei by deuterons on $^{55}$ Mn were measured at energies <20 MeV by the stacked-foil technique and high resolution gamma spectrometry at the U-120M cyclotron of CANAM, NPI CAS. Then all available data for deuterons on 55Mn up to 50 MeV are analyzed paying particular attention to BU and direct reaction (DR) mechanisms. Results: Newly measured activation cross sections strengthen the deuteron database at low energies, at once with a consistent account for the first time of all available data. Conclusions: Due account of deuteron-induced reactions on 55Mn, including particularly the new experimental data at low energies, is provided by a suitable BU and DR assessment.
Comments:
11 pages, 7 figures. arXiv admin note: text overlap with arXiv:1809.02706
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2001.09019 [pdf]
PRC(2020)·6 citations
14
[Submitted on 23 Jan 2020] (cross-list from hep-ph)
\nu \bar{\nu} -Pair Synchrotron Emission in Neutron-Star Matter based on a Relativistic Quantum Approach
Tomoyuki Maruyama A. Baha Balantekin · Myung-Ki Cheoun · Toshitaka Kajino · Grant J. Mathews
We study the neutrino anti-neutrino pair synchrotron emission from electrons and protons in a relativistic quantum approach. This process occurs only under a strong magnetic field, and it is considered to be one of effective processes for neutron star cooling. In this work we calculate the luminosity of the neutrino anti-neutrino pairs emitted from neutron-star-matter with a magnetic field of about 10^{15} G. We find that the energy loss is much larger than that of the modified Urca process. The neutrino anti-neutrino pair emission processes in strong magnetic fields is expected to contribute significantly to the cooling of the magnetars.
Comments:
9 pages , 4 figures. arXiv admin note: text overlap with arXiv:1707.00384
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2001.09020 [pdf]
PLB(2020)·6 citations
15
[Submitted on 24 Jan 2020] (cross-list from nucl-ex)
Shape coexistence in the neutron-deficient $^{188}$ Hg investigated via lifetime measurements
M. Siciliano🇮🇹 · I. Zanon🇮🇹 · A. Goasduff🇮🇹 · P.R. John🇮🇹 · T.R. Rodríguez🇪🇸 · S. Péru🇫🇷 · I. Deloncle🇫🇷 · J. Libert🇫🇷 · M. Zielińska🇫🇷 · D. Ashad🇮🇹 · D. Bazzacco🇮🇹 · G. Benzoni🇮🇹 and 32 other authors
Shape coexistence in the $Z \approx 82$ region has been established in mercury, lead and polonium isotopes. Even-even mercury isotopes with $100 \leq N \leq 106$ present multiple fingerprints of this phenomenon, which seems to be no longer present for $N \geq 110$ . According to a number of theoretical calculations, shape coexistence is predicted in the $^{188}$ Hg isotope. The $^{188}$ Hg nucleus was populated using two different fusion-evaporation reactions with two targets, $^{158}$ Gd and $^{160}$ Gd, and a beam of $^{34}$ S, provided by the Tandem-ALPI accelerators complex at the Laboratori Nazionali di Legnaro. The channels of interest were selected using the information from the Neutron Wall array, while the $γ$ rays were detected using the GALILEO $γ$ -ray array. The lifetimes of the excited states were determined using the Recoil Distance Doppler-Shift method, employing the dedicated GALILEO plunger device. Using the two-bands mixing and rotational models, the deformation of the pure configurations was obtained from the experimental results. The extracted transition strengths were compared with those calculated with the state-of-the-art symmetry-conserving configuration-mixing (SCCM) and five-dimentional collective Hamiltonian (5DCH) approaches in order to shed light on the nature of the observed structures in the $^{188}$ Hg nucleus. An oblate, a normal- and a super-deformed prolate bands were predicted and their underlying shell structure was also discussed.
Comments:
v1: 13 pages, 10 figures, comparison between IBM-CM and SCCM calculations; v2: 16 pages, 13 figures, discussion on the mixing amplitudes from the experimental B(E2) values, comparison between SCCM and 5DCH calculations
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2001.09035 [pdf]
PRC(2020)·19 citations
16
[Submitted on 24 Jan 2020] (cross-list from hep-ph)
Nuclear effects on jet substructure observables at the LHC
Paul Caucal🇫🇷 · Edmond Iancu🇫🇷 · Gregory Soyez🇫🇷
Using a pQCD picture for jet evolution in a dense QCD medium, in which medium-induced parton branchings are factorized from vacuum-like emissions, we study two jet substructure observables: the $z_{g}$ and the Soft Drop multiplicity distributions. We compute the respective nuclear modification factors using a Monte-Carlo implementation of the parton showers. Our results are in qualitative agreement with LHC data for Pb+Pb collisions. We identify the physical mechanisms explaining our results: incoherent jet energy loss, semi-hard medium-induced emissions and the bias introduced by the steeply falling jet spectrum.
Comments:
Presented at the XXVIIIth International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2019), Wuhan, China
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2001.09071 [pdf]
NPA(2021)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE