119782208
The influence of statistical fluctuations on the erraticity behavior of multiparticle system
Abstract It is demonstrated that in a low-multiplicity sample, the increase of the fluctuation of event factorial moments with decreasing phase-space scale, called “erraticity”, is dominated by the statistical fluctuations. The erraticity behavior observed in the NA27 experiment can be readily reproduced by purely statistical fluctuations. Applying the erraticity analysis to a high-multiplicity sample is, however, recommended and the method is improved for the very-high-multiplicity case.
124945127
Longitudinal phase space of multiparticle final states in high energy hadron-hadron collisions
The highly anisotropic phase space (known as longitudinal phase space) of multipartide final states in high energy hh collisions is studied in detail. It is pointed out that the anisotropy of phase space should manifest itself not only in the dramatic difference in magnitude between the average transverse and longitudinal momenta, but also in the anisotropy of dynamical fluctuations in the two directions. It means that the particle distribution in phase space has the property of selfaffine fractal. A method for experimentally testing the selfaffine fractality and measuring its cbaracteristic parameterHurst exponent is given. In addition, the correlation between the degree of longitudinal fractality and the magnitude of average transverse momentum is discussed. A new characteristic quantity--average transverse momentum per event--for de scribing the dynamical property of an event (hard, soft or ultrasoft) is proposed. A comparison of the results with experimental data is given.
116833066
Locating the critical point of QCD phase transition by finite-size scaling
It is pointed out that in relativistic heavy ion collisions, critical related observable in the vicinity of critical point should follow finite-size scaling. The methods of finding and locating critical point are established for the first time by finite-size scaling and its critical characteristics, in particular, the fixed-point and straight-line behavior. As an application of the method, the critical behavior at RHIC data is demonstrated.
118547741
Statistical and dynamical fluctuations of Binder ratios in heavy ion collisions
Higher moments of the net-proton Binder ratio, which is suggested to be a good observation to locate the QCD critical point, is measured in relativistic heavy ion collisions. We first estimate the effect of statistical fluctuations of the third- and fourth-order Binder ratios. Then the dynamical Binder ratio is proposed and investigated in both transport and statistical models. The energy dependence of dynamical Binder ratios with different system sizes at RHIC beam scan energies is presented and discussed.
16991538
On the Dominance of Statistical Fluctuation in the Factorial-Moment Study of Chaos in Low Multiplicity Events of High Energy Collisions
It is shown using Monte Carlo simulation that for low multiplicity events the single-event factorial moments are saturated by the statistical fluctuations. The diverse of the event-space moments $C_{p,q}$ of single-event moments with the diminishing of phase space scale, called ``erraticity'', observed in experiment can readily be reproduced by a flat probability distribution with only statistical fluctuations and therefore does not indicate the existence of chaos as suggested. The possibility of studying chaos in high multiplicity events using erraticity analysis is discussed.
123369286
Local charge nonequilibrium and anomalous energy dependence of normalized moments in narrow rapidity windows
118408012
Measurement of Cosmic Ray Flux in China JinPing underground Laboratory
China JinPing underground Laboratory (CJPL) is the deepest underground laboratory presently running in the world. In such a deep underground laboratory, the cosmic ray flux is a very important and necessary parameter for rare event experiments. A plastic scintillator telescope system has been set up to measure the cosmic ray flux. The performance of the telescope system has been studied using the cosmic ray on the ground laboratory near CJPL. Based on the underground experimental data taken from November 2010 to December 2011 in CJPL, which has effective live time of 171 days, the cosmic ray muon flux in CJPL is measured to be (2.0+-0.4)*10^(-10)/(cm^2)/(s). The ultra-low cosmic ray background guarantees CJPL's ideal environment for dark matter experiment.
119209693
THE DIFFERENT NATURE OF SEYFERT 2 GALAXIES WITH AND WITHOUT HIDDEN BROAD-LINE REGIONS
We compile a large sample of 120 Seyfert 2 galaxies (Sy2s) which contains 49 hidden broad-line region (HBLR) Sy2s and 71 non-HBLR Sy2s. From the difference in the power sources between two groups, we test whether HBLR Sy2s are dominated by active galactic nuclei (AGNs) and whether non-HBLR Sy2s are dominated by starbursts. We show that (1) HBLR Sy2s have larger accretion rates than non-HBLR Sy2s; (2) HBLR Sy2s have larger [Ne V] λ14.32/[Ne II] λ12.81 and [O IV] λ25.89/[Ne II] λ12.81 line ratios than non-HBLR Sy2s; and (3) HBLR Sy2s have smaller IRAS f 60/f 25 flux ratios, which show the relative strength of the host galaxy and nuclear emission, than non-HBLR Sy2s. Consequently, we suggest that HBLR Sy2s and non-HBLR Sy2s are AGN dominated and starburst dominated, respectively. In addition, non-HBLR Sy2s can be classified into luminous (L [O III]>1041 erg s–1) and less luminous (L [O III] < 1041 erg s–1) samples, when considering only their obscuration. We suggest that (1) the invisibility of polarized broad lines (PBLs) in the luminous non-HBLR Sy2s depends on the obscuration and (2) the invisibility of PBLs in the less luminous non-HBLR Sy2s depends on the very low Eddington ratio rather than the obscuration.
120094754
Thermodynamical Behaviors of Nonflat Brans-Dicke Gravity with Interacting New Agegraphic Dark Energy
The dynamical behaviors of Brans–Dicke gravity with the interacting new agegraphic dark energy (NADE) model are studied in this paper. First of all, by considering the dark energy density ρde = 3n2Φη-2, the evolutions of the equation of state and the deceleration parameter can be described in the framework of Friedmann–Robertson–Walker universe. Moreover, the field equations of the Brans–Dicke gravity can be cast to the form of the first law of thermodynamics with the so-called entropy production term . Furthermore, the generalized second law of thermodynamics can be given in nonflat Brans–Dicke gravity with the interacting NADE enclosed by the dynamical apparent horizon with Hawking temperature. Finally, when the interaction between NADE and dark matter is considered as a fluctuation around the thermal equilibrium, it can be written to a form of logarithmic correction, and the expression of the interaction term can be obtained.
118401402
Constraints on a decomposed dark fluid with constant adiabatic sound speed by jointing the geometry test and growth rate after Planck data
In this paper, a unified dark fluid with constant adiabatic sound speed is decomposed into cold dark matter interacting with vacuum energy. Based on a Markov-chain Monte Carlo method, we constrain this model by jointing the geometry and dynamical measurement. The geometry test includes cosmic microwave background radiation from Planck, baryon acoustic oscillation, and type-Ia supernovae; the dynamic measurement is $f{\ensuremath{\sigma}}_{8}(z)$ data points, which is obtained from the growth rate via redshift space distortion, and ${\ensuremath{\sigma}}_{8}(z)$ is the root-mean-square amplitude of the density contrast $\ensuremath{\delta}$ at the comoving $8{h}^{\ensuremath{-}1}\text{ }\text{ }\mathrm{Mpc}$ scale. The jointed constraint shows that $\ensuremath{\alpha}=0.00066{2}_{\ensuremath{-}0.000662}^{+0.000173}$ and ${\ensuremath{\alpha}}_{8}=0.82{4}_{\ensuremath{-}0.0166}^{+0.0128}$. The CMB and matter power spectra are both similar for the case of $\ensuremath{\alpha}=\text{mean}$ value and that of $\ensuremath{\alpha}=0$. However, the evolutionary curves of $f{\ensuremath{\sigma}}_{8}(z)$ are different. This means that, to some extent, the data points of the growth rate could break the degeneracy of the dark energy models.
119273059
Does accelerating universe indicate Brans-Dicke theory?
The evolution of the universe in Brans-Dicke (BD) theory is discussed in this paper. Considering a parameterized scenario for BD scalar field φ = φ0aα which plays the role of gravitational constant G, we apply the Markov Chain Monte Carlo method to investigate a global constraints on BD theory with a self-interacting potential according to the current observational data: the Union2 dataset of type-Ia supernovae (SNIa), the high-redshift Gamma-Ray Bursts (GRBs) data, the observational Hubble data (OHD), the cluster X-ray gas mass fraction, the baryon acoustic oscillation (BAO), and the cosmic microwave background (CMB) data. It is shown that an expanded universe from deceleration to acceleration is given in this theory, and the constraint results of dimensionless matter density Ω0m and parameter α are, Ω0m = 0.286−0.039−0.047+0.037+0.050 and α = 0.0046−0.0171−0.0206+0.0149+0.0171 which is consistent with the result of current experiment exploration, |α| ≤ 0.132124. In addition, we use the geometrical diagnostic method, jerk parameter j, to distinguish the BD theory and the cosmological constant model in Einstein’s theory of general relativity.