Nuclear Theory·nucl-th

Friday·January 31, 2020

8 papers—3 primary·5 cross-listed

01
[Submitted on 29 Jan 2020]
The QCD phase diagram and statistics friendly distributions
Volker Koch🇺🇸 · Adam Bzdak🇵🇱 · Dmytro Oliinychenko🇺🇸 · Jan Steinheimer🇩🇪
The preliminary STAR data for proton cumulants for central collisions at \sqrt{s}=7.7 GeV are consistent with a two-component proton multiplicity distribution. We show that this two-component distribution is statistics friendly in that factorial cumulants of surprisingly high orders may be extracted with a relatively small number of events. As a consequence the two-component model can be tested and verified right now with the presently available STAR data from the first phase of the RHIC beam energy scan.
Comments:
Proceedings, Quark Matter 2019, Wuhan
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2001.11079 [pdf]
NPA(2021)·5 citations
02
[Submitted on 29 Jan 2020]
Production of $^{4} Li$ and $p -^{3} He$ correlation function in relativistic heavy-ion collisions
Sylwia Bazak🇵🇱 · Stanislaw Mrowczynski🇵🇱
The thermal and coalescence models both describe well yields of light nuclei produced in relativistic heavy-ion collisions at LHC. We propose to measure the yield of $^{4} Li$ and compare it to that of $^{4} He$ to falsify one of the models. Since the masses of $^{4} He$ and $^{4} Li$ are almost equal, the yield of $^{4} Li$ is about 5 times bigger than that of $^{4} He$ in the thermal model because of different numbers of spin states of the two nuclides. Their internal structures are, however, very different: the alpha particle is well bound and compact while $^{4} Li$ is weakly bound and loose. Consequently, the ratio of yields of $^{4} Li$ to $^{4} He$ is significantly smaller in the coalescence model and it strongly depends on the collision centrality. Since the nuclide $^{4} Li$ is unstable and it decays into $^{3} He$ and $p$ , the yield of $^{4} Li$ can be experimentally obtained through a measurement of the $p -^{3} He$ correlation function. The function carries information not only about the yield of $^{4} Li$ but also about the source of $^{3} He$ and allows one to determine through a source-size measurement whether of $^{3} He$ is directly emitted from the fireball or it is formed afterwards. We compute the correlation function taking into account the $s -$ wave scattering and Coulomb repulsion together with the resonance interaction responsible for the $^{4} Li$ nuclide. We discuss how to infer information about an origin of $^{3} He$ from the correlation function, and finally a method to obtain the yield of $^{4} Li$ is proposed.
Comments:
16 pages, 10 figures, to appear in European Physical Journal A Topical Issue on "Light clusters in nuclei and nuclear matter: Nuclear structure and decay, heavy ion collisions, and astrophysics". arXiv admin note: substantial text overlap with arXiv:2004.07029
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2001.11351 [pdf]
EPJA(2020)·27 citations
03
[Submitted on 30 Jan 2020]
Angular distribution of fragments in neutron-induced nuclear fission at energies 1-200 MeV: data, theoretical models and relevant problems
A. L. Barabanov · A. S. Vorobyev · A. M. Gagarski · O. A. Shcherbakov · L. A. Vaishnene
In recent years, investigations of angular distributions of fragments in neutron-induced nuclear fission have been extended to intermediate energies, up to 200 MeV, as well as to a wide range of target isotopes. Using as an example the latest data obtained by our group for the reaction 237-Np(n,f), we discuss the specific features of fission fragment angular distribution and present a method for their simulation based on the code TALYS. It is shown that a simplified model reasonably describes energy dependence of the angular distribution in the whole range 1-200 MeV. The ways to improve the model are discussed along with the possibilities to use it for obtaining new information on fission and pre-equilibrium processes in neutron-nucleus interaction. We consider also the relevant problems of describing fission fragment angular distributions.
Comments:
11 pages, 3 figures, Research was presented at the THEORY-5 Scientific Workshop on "Nuclear Fission Dynamics and the Emission of Prompt Neutrons and Gamma Rays", Castelvecchio Pascoli, Barga, Italy, September 24-26, 2019
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2001.11373 [pdf]
EPJ Web Conf.(2021)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

The QCD phase diagram and statistics friendly distributions

Production of 4Li and p−3He correlation function in relativistic heavy-ion collisions

Angular distribution of fragments in neutron-induced nuclear fission at energies 1-200 MeV: data, theoretical models and relevant problems

Affiliations

Production of $^{4} Li$ and $p -^{3} He$ correlation function in relativistic heavy-ion collisions