Nuclear Theory·nucl-th

Thursday·February 12, 2015

7 papers—4 primary·3 cross-listed

05
[Submitted on 10 Feb 2015] (cross-list from hep-ph)
Constraints on string percolation model from anomalous centrality evolution data in Au-Au collisions at $s_{NN} =$ 62 and 200 GeV
Grigory Feofilov🇷🇺 · Igor Altsybeev🇷🇺 · Olga Kochebina🇫🇷
Anomalous centrality evolution of two-particle angular correlations observed in Au-Au collisions at $s_{N N} = 62$ and 200 GeV and the onset of ridge structures are considered in the model of interacting quark-gluon strings. We assume that at the given energy of nucleus-nucleus collisions the critical energy density may be reached at the specific centrality. In a string percolation model this might be treated equivalently to a formation of a large cluster of strings characterized by the critical string density, with a size comparable to the whole area of interaction of two nuclei. This hypothesis allows to define some constraints on the string percolation model using data on transitional centralities in Au-Au collisions at these two energies. Results are extrapolated to the LHC energy where high string densities (exceeding the critical value) are confirmed for all classes of centralities in Pb-Pb collisions. Interaction between strings inside large clusters formed in nucleus-nucleus collisions is considered in a simplified Monte Carlo model. This model is applied to the qualitative analysis of the onset of collectivity and the ridge formation in Pb-Pb collisions. It is shown that the approach of the repulsive string-string interaction is capable to explain the appearance of elliptic and triangular flow observed in nucleus-nucleus collisions at RHIC and LHC energies.
Comments:
11 pages, 5 figures, proc. Baldin ISHEPP XXII; PoS (Baldin ISHEPP XXII) 067 (2015)
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1502.03144 [pdf]
PoS(2015)·2 citations
06
[Submitted on 11 Feb 2015] (cross-list from hep-ph)
Hypothesis about semi-weak interaction and experiments with solar neutrinos
L.M. Slad🇷🇺
A new concept is proposed to solve the solar neutrino problem, that is based on a hypothesis about the existence of semi-weak interaction of electron neutrinos with nucleons mediated by massless pseudoscalar bosons. Owing to about 10 collisions of a solar neutrino with nucleons of the Sun, the fluxes of left- and right-handed solar neutrinos at the Earth surface are approximately equal, and their spectrum is changed in comparison with the one at the production moment. The postulated model with one free parameter provides a good agreement between the calculated and experimental characteristics of the processes with solar neutrinos: $^{37} Cl \to^{37} Ar$ , $^{71} Ga \to^{71} Ge$ , $ν_{e} e^{-} \to ν_{e} e^{-}$ , and $ν_{e} D \to e^{-} pp$ .
Comments:
12 pages. The main material is contained in JETP 129 (2019) 973
Subjects:
High Energy Physics — Phenomenology (hep-ph); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1502.03262 [pdf]
4 citations
07
[Submitted on 11 Feb 2015] (cross-list from hep-ph)
Self-consistent statistical error analysis of $π π$ scattering
R. Navarro Pérez🇪🇸 · E. Ruiz Arriola🇪🇸 · J. Ruiz de Elvira🇩🇪
We analyze the conditions under which a statistical error analysis can be carried out in the case of $π π$ scattering, namely the normality of residuals in the conventional $χ^{2}$ -fit method. Here we check that the current and benchmarking analyses only present very small violations of the normality requirements. In particular, we show how it is possible to amend slightly the selection of the experimental data, and improve the normality of residuals. As an example, we discuss the $0^{++}$ channel and the implications for the $f_{0} (500)$ and $f_{0} (980)$ resonances, obtaining that the new selection of data provides very similar and compatible results. In addition, the effect on the $f_{0} (500)$ and $f_{0} (980)$ resonance pole parameters is almost negligible, which reinforces the central results and the uncertainty analysis performed in these benchmarking determinations.
Comments:
17 pg, 22 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1502.03361 [pdf]
PRD(2015)·32 citations

Affiliations

first authorsco-authorsvia INSPIRE

Constraints on string percolation model from anomalous centrality evolution data in Au-Au collisions at sNN​​= 62 and 200 GeV

Hypothesis about semi-weak interaction and experiments with solar neutrinos

Self-consistent statistical error analysis of ππ scattering

Affiliations

Constraints on string percolation model from anomalous centrality evolution data in Au-Au collisions at $s_{NN} =$ 62 and 200 GeV

Self-consistent statistical error analysis of $π π$ scattering