Nuclear Theory·nucl-th

Friday·September 8, 2017

8 papers—4 primary·4 cross-listed

01
High cumulants of conserved charges and their statistical uncertainties
Li-Zhu Chen🇨🇳 · Ye-Yin Zhao🇨🇳 · Xue Pan🇨🇳 · Zhi-Ming Li🇨🇳 · Yuan-Fang Wu🇨🇳
We study the influence of measured high cumulants of conserved charges on their associated statistical uncertainties in relativistic heavy-ion collisions. With a given number of events, the measured cumulants randomly fluctuate with an approximately normal distribution, while the estimated statistical uncertainties are found to be correlated with corresponding values of the obtained cumulants. Generally, with a given number of events, the larger the cumulants we measure, the larger the statistical uncertainties that are estimated. The error-weighted averaged cumulants are dependent on statistics. Despite this effect, however, it is found that the three sigma rule of thumb is still applicable when the statistics are above one million.
nucl-thhep-phCPC(2017)·3 citations
02
Relation of $a^{†} a$ terms to higher-order terms in the adiabatic expansion for large-amplitude collective motion
Koichi Sato
We investigate the relation of $a^{†} a$ terms in the collective operator to the higher-order terms in the adiabatic self-consistent collective coordinate (ASCC) method. In the ASCC method, a state vector is written as $e^{i G^(q, p, n)} ∣ ϕ (q)⟩$ with $G^(q, p, n)$ which is a function of collective coordinate $q$ , its conjugate momentum $p$ and the particle number $n$ . According to the generalized Thouless theorem, $G^$ can be written as a linear combination of two-quasiparticle creation and annihilation operators $a_{μ}^{†} a_{ν}^{†}$ and $a_{ν} a_{μ}$ . We show that, if $a^{†} a$ terms are included in $G^(q, p, n)$ , it corresponds to the higher-order terms in the adiabatic expansion of $G^$ . This relation serves as a prescription to determine the higher-order collective operators from the $a^{†} a$ part of the collective operator, once it is given without solving the higher-order equations of motion.
nucl-thPTEP(2017)·1 citation
03
Thermodynamics and relativistic kinetic theory for q-generalized Bose-Einstein and Fermi-Dirac systems
Sukanya Mitra🇮🇳
The thermodynamics and covariant kinetic theory have been elaborately investigated in a non-extensive environment considering the non-extensive generalization of Bose-Einstein (BE) and Fermi-Dirac (FD) statistics. Starting with Tsallis' entropy formula, the fundamental principles of thermostatistics have been established for a grand canonical system having q-generalized BE/FD degrees of freedom. The many particle kinetic theory has been set up in terms of the relativistic transport equation with q-generalized Uehling-Uhlenbeck collision term. The conservation laws have been realized in terms of appropriate moments of the transport equation. The thermodynamic quantities have been obtained in weak non-extensive environment for a massive pion-nucleon and a massless quark-gluon system with non-zero baryon chemical potential. In order to get an estimate of the impact of non-extensivity on the system dynamics, the q-modified Debye mass and hence the q-modified effective coupling have been estimated for a quark-gluon system.
nucl-thEPJC(2018)·17 citations
04
Updated three-body model of $^{6}$ He $β$ decay into the $α$ + $d$ continuum
E.M. Tursunov · D. Baye · P. Descouvemont
The $β$ -decay process of the $^{6}$ He halo nucleus into the $α + d$ continuum is studied in an updated three-body model. The $^{6}$ He nucleus is described as an $α + n + n$ system in hyperspherical coordinates on a Lagrange-mesh. The shape and absolute values of the transition probability per time and energy units of new experiments are reproduced with a modified $α + d$ potential. The obtained total transition probabilities are $2.48 \times 1 0^{- 6}$ s $^{- 1}$ for the full energy region and $2.40 \times 1 0^{- 6}$ s $^{- 1}$ for the cut-off $E > 150$ keV. The strong cancellation between the internal and halo parts of the $β$ decay matrix element is a challenge for future {\it ab initio} calculations.
nucl-thPRC(2018)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

High cumulants of conserved charges and their statistical uncertainties

Relation of a†a terms to higher-order terms in the adiabatic expansion for large-amplitude collective motion

Thermodynamics and relativistic kinetic theory for q-generalized Bose-Einstein and Fermi-Dirac systems

Updated three-body model of 6He β decay into the α + d continuum

Affiliations

Relation of $a^{†} a$ terms to higher-order terms in the adiabatic expansion for large-amplitude collective motion

Updated three-body model of $^{6}$ He $β$ decay into the $α$ + $d$ continuum