Nuclear Theory·nucl-th

Tuesday·September 20, 2016

13 papers—9 primary·4 cross-listed

01
[Submitted on 17 Sept 2016]
Centrality dependence of chemical freeze-out parameters from net-proton and net-charge fluctuations using hadron resonance gas model
Rama Prasad Adak🇮🇳 · Supriya Das🇮🇳 · Sanjay K. Ghosh🇮🇳 · Rajarshi Ray🇮🇳 · Subhasis Samanta🇮🇳
We estimate chemical freeze-out parameters in HRG and EVHRG model by fitting the experimental information of net-proton and net-charge fluctuations measured in Au + Au collisions by the STAR collaboration at RHIC. We observe that chemical freeze-out parameters obtained from lower and higher order fluctuations are though almost same for $s_{N N} > 27$ GeV, tend to deviate from each other at lower $s_{N N}$ . Moreover, these separations increase with decrease of $s_{N N}$ and for a fixed $s_{N N}$ increase towards central collisions. Furthermore, we observe an approximate scaling behaviour of $(μ_{B} / T) / (μ_{B} / T)_{ce n t r a l}$ with $(N_{p a r t}) / (N_{p a r t})_{ce n t r a l}$ for the parameters estimated from lower order fluctuations for 11.5 GeV $\leq s_{N N} \leq$ 200 GeV. Scaling is violated for the parameters estimated from higher order fluctuations for $s_{N N} = 11.5$ and 19.6 GeV. It is observed that the chemical freeze-out parameter, which can describe $σ^{2} / M$ of net-proton very well in all energies and centralities, can not describe the $s σ$ equally well and vice versa.
Comments:
11 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1609.05318 [pdf]
PRC(2017)·24 citations
02
[Submitted on 18 Sept 2016]
Predictions on the alpha decay chains of superheavy nuclei with Z =121 within the range 290 $\leq$ A $\leq$ 339
K. P. Santhosh · C. Nithya
A systematic study on the alpha decay half lives of various isotopes of superheavy element \textit{Z} = 121 within the range 290 $\leq$ A $\leq$ 339 is presented for the first time using Coulomb and proximity potential model for deformed nuclei (CPPMDN). The calculated $α$ decay half lives of the isotopes within our formalism match well with the values computed using Viola-Seaborg systematic, Universal curve of Poenaru et al., and the analytical formula of Royer. In our study by comparing the $α$ decay half lives with the spontaneous fission half lives, we have predicted $2 α$ chain from $^{309, 311, 312}$ 121, $3 α$ chain from $^{310}$ 121 and $1 α$ chain from $^{313, 314}$ 121. Clearly our study shows that the isotopes of superheavy element \textit{Z} = 121 within the mass range 309 $\leq$ A $\leq$ 314 will survive fission and can be synthesized and detected in the laboratory via alpha decay. We hope that our predictions will provide a new guide to future experiments.
Comments:
16 pages, 6 figures. arXiv admin note: text overlap with arXiv:1604.00296, arXiv:1504.00872
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1609.05495 [pdf]
IJMPE(2016)·8 citations
03
[Submitted on 18 Sept 2016]
Feasibility of observing the {\alpha} decay chains from isotopes of SHN with Z = 128, Z = 126, Z = 124 and Z = 122
K. P. Santhosh · B. Priyanka · C. Nithya
Taking the Coulomb and proximity potential model for deformed nuclei (CPPMDN) as the interacting potential for the post-scission region, the alpha decay properties of 34 isotopes of the superheavy nuclei with Z = 128 within the range 306 $\leq$ A $\leq$ 339 have been studied, considering both the parent and daughter nuclei to be deformed. The manuscript also deals with the decay properties of the isotopes of Z = 126 (within 288 $\leq$ A $\leq$ 339), Z = 124 (within 284 $\leq$ A $\leq$ 339) and Z = 122 (within 280 $\leq$ A $\leq$ 339). The alpha decay half lives thus evaluated has been compared with the values evaluated using other theoretical models and it was seen that, our theoretical alpha decay half lives matches well with these values. Through the present study, we have underlined and have established the fact that, among the 192 isotopes considered in the present study, only those isotopes $^{321 - 324, 328 - 335}$ 128, $^{318 - 320, 323 - 327}$ 126, $^{305 - 308, 315 - 322}$ 124 and $^{298 - 307, 311 - 314}$ 122 can be synthesized and detected through alpha decay in laboratory. As the alpha decay half lives of these superheavy isotopes lie within the experimental limits, we hope these predictions, on the decay modes of these unknown nuclei, to pave the way for the future experiments. The proton separation energy calculations on $^{306 - 339}$ 128, $^{288 - 336}$ 126, $^{284 - 339}$ 124 and $^{280 - 339}$ 122 superheavy nuclei have also been done and the study revealed the probable proton emitters among these nuclei.
Comments:
37 pages, 13 figures. arXiv admin note: text overlap with arXiv:1604.00296, arXiv:1504.00872
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1609.05498 [pdf]
NPA(2016)·26 citations
04
[Submitted on 19 Sept 2016]
Proton-proton hollowness at the LHC from inverse scattering
Enrique Ruiz Arriola🇪🇸 · Wojciech Broniowski🇵🇱
Parameterizations of the pp scattering data at the LHC collision energies indicate a hollow in the inelasticity profile of the pp interaction, with less absorption for head-on collisions than at a non-zero impact parameter. We show that some qualitatively unnoticed features may be unveiled by a judicious application of the inverse scattering problem in the eikonal approximation and interpre- tation within an optical potential model. The hollowness effect is magnifed in a 3D picture of the optical potential, and will presumably be enhanced at yet higher energies. Moreover, in 3D it sets in at much smaller energies than at the LHC. We argue that hollowness in the impact parameter is a quantum effect, relying on the build-up of the real part of the eikonal scattering phase and its possible passage through $π /2$ . We also show that it precludes models of inelastic collisions where inelasticity is obtained by naive folding of partonic densities.
Comments:
9 pages, 6 figures,expanded version with further discussions
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1609.05597 [pdf]
PRD(2017)·29 citations
05
[Submitted on 19 Sept 2016]
Photoproduction of $π^{0}$ -Mesons on the Nucleon and Deuteron
Eed M. Darwish🇸🇦 · A. Hemmdan🇪🇬 · N. T. El-Shamy🇪🇬
The photoproduction of $π^{0}$ -mesons from the nucleon and deuteron has been studied for incidents of photon energies up to 1.5 GeV. By using the MAID-2007 model for the process on the nucleon, we predict results for the unpolarized and helicity-dependent total cross sections of the semi-exclusive reaction $γ d \to π^{0} X$ ( $X = n p + d$ ) with the inclusion of rescattering effects. We find that rescattering effects yield a substantially large contribution. The extracted results are compared with the available experimental data and a satisfactory agreement is obtained. In addition, the contribution of $γ d \to π^{0} X$ ( $X = n p + d$ ) to the finite GDH integral has been evaluated by explicit integration up to 1.5 GeV and a total value of 256.96 $μ$ b has been obtained. Convergence of the GDH integral has been reached.
Comments:
Mini Review, 6 Pages, 6 Figures, 1 Table
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1609.05628 [pdf]
Makara J.Sci.(2016)·3 citations
06
[Submitted on 19 Sept 2016]
Nuclear structure calculations for two-neutrino double-beta decay
P. Sarriguren · O. Moreno · E. Moya de Guerra
We study the two-neutrino double-beta decay in 76Ge, 116Cd, 128Te, 130Te, and 150Nd, as well as the two Gamow-Teller branches that connect the double-beta decay partners with the states in the intermediate nuclei. We use a theoretical microscopic approach based on a deformed selfconsistent mean field with Skyrme interactions including pairing and spin-isospin residual forces, which are treated in a proton-neutron quasiparticle random-phase approximation. We compare our results for Gamow-Teller strength distributions with experimental information obtained from charge-exchange reactions. We also compare our results for the two-neutrino double-beta decay nuclear matrix elements with those extracted from the measured half-lives. Both single-state and low-lying-state dominance hypotheses are analyzed theoretically and experimentally making use of recent data from charge-exchange reactions and beta decay of the intermediate nuclei.
Comments:
11 pages, 6 figures. arXiv admin note: text overlap with arXiv:1502.05889
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1609.05648 [pdf]
Adv.High Energy Phys.(2016)·6 citations
07
[Submitted on 19 Sept 2016]
Heavy quark dynamics in QCD matter
Santosh K. Das🇮🇹 · Francesco Scardina🇮🇹 · Salvatore Plumari🇮🇹 · Vincenzo Greco🇮🇹
Simultaneous description of heavy quark nuclear suppression factor $R_{AA}$ and the elliptic flow $v_{2}$ is a top challenge for all the existing models. We highlight how the temperature dependence of the energy loss/transport coefficients is responsible to address a large part of such a puzzle along with the the full solution of the Boltzmann collision integral for the momentum evolution of heavy quark. We consider four different models to evaluate the temperature dependence of drag coefficients of the heavy quark in the QGP. We have also highlighted the heavy quark dynamics in the presence of an external electromagnetic field which develops a sizable heavy quark directed flow, $v_{1} (y)$ , can be measurable at LHC.
Comments:
4 pages, To appear in the proceedings of SQM-2016
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1609.05751 [pdf]
J.Phys.Conf.Ser.(2017)·1 citation
08
[Submitted on 19 Sept 2016]
Some aspects on four quarks recombination
G. Toledo Sanchez🇲🇽 · I. A. Toledano Juarez🇲🇽
We have performed a 3-D Monte Carlo simulation of a system composed of two identical light quarks ( $q q$ ) and two identical antiquarks ( $Q ˉ Q ˉ$ ) and determined whether it is energetically more favorable to form a tetraquark or two mesons, as a function of the interparticle separation distance which, for a fixed number of particles, can be identified as a particle density. In this proceedings, we highlight the main results and elaborate on the implications in properties like the correlation function for two-mesons and characterize the isolated diquark correlation function. We analize the four-body potential evolution and exhibit its linear behavior as a function of the invariant distance. We track the dynamical flipping among configurations to determine the recombination probability, exhibiting the importance of the tetraquark state.
Comments:
To be published in Journal of Physics Conference Series (IOP). Joint Proceedings of the XV Mexican Workshop on Particles and Fields & the XXX Annual Meeting of the Division of Particles and Fields of the Mexican Physical Society
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1609.05753 [pdf]
J.Phys.Conf.Ser.(2016)·0 citations
09
[Submitted on 15 Sept 2016]
The physics mechanisms of light and heavy flavor $v_{2}$ and mass ordering in AMPT
Hanlin Li🇨🇳 · Zi-Wei Lin🇨🇳 · Fuqiang Wang🇺🇸
A Multi-Phase Transport (AMPT) model has been shown to describe experimental data well, such as the bulk properties of particle spectra and elliptic anisotropy ( $v_{2}$ ) in heavy ion collisions. Recent studies have shown that AMPT describes the $v_{2}$ data in small system collisions as well. In these proceedings, we first investigate the origin of the mass ordering of identified hadrons $v_{2}$ in heavy ion as well as small system collisions. We then study the production mechanism of the charm $v_{2}$ in light of the escape mechanism for the light quark $v_{2}$ .
Comments:
SQM2016 proceeding, 4 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1609.05862 [pdf]
J.Phys.Conf.Ser.(2017)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE