共查询到20条相似文献,搜索用时 46 毫秒
1.
Hans Christian ?ttinger 《Journal of statistical physics》2010,138(6):1067-1083
We elaborate and compare two approaches to nonequilibrium thermodynamics, the two-generator bracket formulation of time-evolution equations for averages and the macroscopic fluctuation theory, for a purely dissipative isothermal driven diffusive system under steady state conditions. The fluctuation dissipation relations of both approaches play an important role for a detailed comparison. The nonequilibrium Helmholtz free energies introduced in these two approaches differ as a result of boundary conditions. A Fokker-Planck equation derived by projection operator techniques properly reproduces long range fluctuations in nonequilibrium steady states and offers the most promising possibility to describe the physically relevant fluctuations around macroscopic averages for time-dependent nonequilibrium systems. 相似文献
2.
Paul Sorensen 《The European Physical Journal C - Particles and Fields》2009,61(4):829-833
Recent data from heavy ion collisions at RHIC show strong near-side correlations extending over several units of rapidity.
This ridge-like correlation exhibits an abrupt onset with collision centrality. In this talk, I argue that the centrality
and beam-energy dependence of these near-angle correlations could provide access to information about the Quark Gluon Plasma
phase boundary and the Equation of State of nuclear matter. A beam-energy-scan at RHIC will better reveal the true source
of these correlations and should be a high priority at RHIC. 相似文献
3.
M. Hauer V. V. Begun M. I. Gorenstein 《The European Physical Journal C - Particles and Fields》2008,58(1):83-110
The aim of this paper is to introduce a new technique for the calculation of observables, in particular multiplicity distributions,
in various statistical ensembles at finite volume. The method is based on Fourier analysis of the grand canonical partition
function. A Taylor expansion of the generating function is used to separate contributions to the partition function in their
power in volume. We employ Laplace’s asymptotic expansion to show that any equilibrium distribution of multiplicity, charge,
energy, etc. tends to a multivariate normal distribution in the thermodynamic limit. A Gram–Charlier expansion additionally
allows for the calculation of finite volume corrections. Analytical formulas are presented for the inclusion of resonance
decay and finite acceptance effects directly into the partition function of the system. This paper consolidates and extends
previously published results of the current investigation into the properties of statistical ensembles. 相似文献
4.
5.
M. Agop O. Niculescu A. Timofte L. Bibire A. S. Ghenadi A. Nicuta C. Nejneru G. V. Munceleanu 《International Journal of Theoretical Physics》2010,49(7):1489-1506
Considering that the motions of the particles take place on fractals, a non-differentiable mechanical model is built. Only if the spatial coordinates are fractal functions, the Galilean version of our model is obtained: the geodesics satisfy a Navier-Stokes-type of equation with an imaginary viscosity coefficient for a complex speed field or respectively, a Schrödinger-type of equation or hydrodynamic equations, in the case of irrotational movements. Moreover, in this approach, the analysis of the fractal fluid dynamics generates conductive properties in the case of movements synchronization both on differentiable and fractal scales, and convective properties in the absence of synchronization (e.g. laser ablation plasma is analyzed). On the other hand, if both the spatial and temporal coordinates are fractal functions, it results that, the geodesics satisfy a Klein-Gordon-type of equation on a Minkowskian manifold. 相似文献
6.
L. A. Harland-Lang V. A. Khoze M. G. Ryskin W. J. Stirling 《The European Physical Journal C - Particles and Fields》2010,69(1-2):179-199
Central exclusive production (CEP) processes in high-energy proton—(anti)proton collisions offer a very promising framework within which to study both novel aspects of QCD and new physics signals. Among the many interesting processes that can be studied in this way, those involving the production of heavy (c,b) quarkonia and γ γ states have sufficiently well understood theoretical properties and sufficiently large cross sections that they can serve as ‘standard candle’ processes with which we can benchmark predictions for new physics CEP at the CERN Large Hadron Collider. Motivated by the broad agreement with theoretical predictions of recent CEP measurements at the Fermilab Tevatron, we perform a detailed quantitative study of heavy quarkonia (χ and η) and γ γ production at the Tevatron, RHIC and LHC, paying particular attention to the various uncertainties in the calculations. Our results confirm the rich phenomenology that these production processes offer at present and future high-energy colliders. 相似文献
7.
Hye Won Kim Eun-Kyung Ahn Bo Keun Jee Hyoung-Kyu Yoon Kweon Haeng Lee Young Lim 《Journal of nanoparticle research》2009,11(1):55-65
In urban areas, the quantity of exhaust particles from vehicle emissions is tremendous and has been regarded as the main contributor
to particulate matter (PM) pollution. Recently, the nano-sized PM on public health has begun to raise the attention. The increased
toxicity of nanoparticulate can be largely explained by their small size, high airborne concentration, extensive surface area
and high content of organic carbon and transition metals. We have attempted to address the toxicity of nano sized-particlulate
matter by comparing various particulates including micro-SiO2 (mSiO2), nano-SiO2 (nSiO2), micro-TiO2 (mTiO2), and nano-TiO2 (nTiO2) in RAW264.7 cells and in vivo. The cell viability of all particulates decreased dose dependently. 24-h incubation with nSiO2
demonstrated apoptosis in RAW264.7 using Annexin-V binding immunofluorescent microscopy, but not in any other particulates.
In vivo, cytotoxicity of nanosized was higher than micro-sized particulates. As higher the concentration of particulates,
the more pulmonary injury and neutrophilic infiltration were observed in nano-sized than micro-sized particulates, respectively.
Particularly, 5.0 mg/kg of mTiO2 never shows any increase of neutrophile even with high cellularity of total cells and macrophages. From these results, we
suggested that particulate-induced respiratory toxicity be influenced by component, size, and dose of particulates including
the characteristic nature of the target cells in vitro and in vivo. 相似文献
8.
V. A. Khoze F. Krauss A. D. Martin M. G. Ryskin K. C. Zapp 《The European Physical Journal C - Particles and Fields》2010,69(1-2):85-93
We note that the definition of diffractive events is a matter of convention. We discuss two possible “definitions”: one based on unitarity and the other on Large Rapidity Gaps (LRG) or Pomeron exchange. LRG can also arise from fluctuations and we quantify this effect and some of the related uncertainties. We find care must be taken in extracting the Pomeron contribution from LRG events. We show that long-range correlations in multiplicities can arise from the same multi-Pomeron diagrams that are responsible for LRG events, and we explain how early LHC data can illuminate our understanding of ‘soft’ interactions. 相似文献
9.
By embedding a free function into a compatible zero curvature equation, we propose a lattice hierarchy with the free function
which still admits zero curvature representation. It is interesting that the hierarchy can reduce the Ablowitz-Ladik hierarchy,
the Volterra hierarchy and a new hierarchy by properly choosing the embedded function. Moreover, the new hierarchy is integrable
in Liouville’s sense and possess multi-Hamiltonian structure. 相似文献
10.
A. Bolshakova I. Boyko G. Chelkov D. Dedovitch A. Elagin M. Gostkin S. Grishin A. Guskov Z. Kroumchtein Yu. Nefedov K. Nikolaev A. Zhemchugov F. Dydak J. Wotschack A. De Min V. Ammosov V. Gapienko V. Koreshev A. Semak Yu. Sviridov E. Usenko V. Zaets 《The European Physical Journal C - Particles and Fields》2009,62(4):697-754
We report on double-differential inclusive cross-sections of the production of secondary protons and charged pions, in the
interactions with a 5% λ
abs thick stationary beryllium target, of proton and pion beams with momentum from ±3 GeV/c to ±15 GeV/c. Results are given for secondary particles with production angles 20° <θ<125°. 相似文献
11.
Linsen Zhang Puxun Wu Hongwei Yu 《The European Physical Journal C - Particles and Fields》2011,71(3):1588
In this paper, two modified Ricci models are considered as the candidates of unified dark matter–dark energy. In model one,
the energy density is given by rMR=3Mpl(aH2+b[(H)\dot])\rho_{\mathrm{MR}}=3M_{\mathrm{pl}}(\alpha H^{2}+\beta\dot{H}), whereas, in model two, by
rMR=3Mpl(\fraca6 R+g[(H)\ddot]H-1)\rho_{\mathrm{MR}}=3M_{\mathrm{pl}}(\frac{\alpha}{6} R+\gamma\ddot{H}H^{-1}). We find that they can explain both dark matter and dark energy successfully. A constant equation of state of dark energy
is obtained in model one, which means that it gives the same background evolution as the wCDM model, while model two can give an evolutionary equation of state of dark energy with the phantom divide line crossing
in the near past. 相似文献
12.
We investigate the cosmological evolution of the tachyon and phantom-tachyon scalar field by considering the potential parameter $\Gamma(=\frac{VV''}{V'^{2}}$ ) as a function of another potential parameter $\lambda(=\frac{V'}{\kappa V^{3/2}}$ ), which correspondingly extends the analysis of the evolution of our universe from a two-dimensional autonomous dynamical system to the three-dimensional case. It allows us to investigate the more general situation where the potential is not restricted to an inverse square potential. One particular result is that, apart from the inverse square potential, there are a large number of potentials which can give the scaling and dominant solution when the function Γ(λ) equals 3/2 for one or more values of λ *, as well as that the parameter λ * satisfies certain conditions. We also find that for a class of different potentials the possibilities for the dynamical evolution of the universe are actually the same and therefore undistinguishable. 相似文献
13.
Mubasher Jamil Farook Rahaman Mehedi Kalam 《The European Physical Journal C - Particles and Fields》2009,60(1):149-156
The standard model of cosmology is investigated using a time-dependent cosmological constant Λ and Newton gravitational constant G. The total energy content is described by the modified Chaplygin gas equation of state. It is found that the time-dependent
constants coupled with the modified Chaplygin gas interpolate between the earlier matter to the later dark-energy dominated
phase of the universe. We also achieve a convergence of the parameter ω→−1, almost at the present time. Thus our model fairly alleviates the cosmic-coincidence problem, which demands ω=−1 at the present time. 相似文献
14.
Zhao-Xian Yu Fu-Ping Liu Zhi-Yong Jiao 《International Journal of Theoretical Physics》2008,47(5):1206-1210
By using of the Lewis-Riesenfeld invariant theory, dynamical and geometric phases of Bose-Einstein condensates are studied.
The Aharonov-Anandan phase is also obtained under the cyclical evolution. 相似文献
15.
The isotropic oscillator on a plane is discussed where the coordinate and momentum space are both considered to be non-commutative.
We also discuss the symmetry properties of the oscillator for three separate cases when the non-commutative parameters Θ and
for x and p-space, respectively, satisfy specific relations. We compare the Landau problem with the isotropic oscillator on non-commutative
space and obtain a relation between the two non-commutative parameters and the magnetic field of the Landau problem. 相似文献
16.
In this paper, we study the symmetries of massless and massive particles action. By considering the non-commutative space-time,
we find appropriate non-commutative relation for relativistic particles which leaves invariant the non-commutative Minkowski
space-time. We show that non-commutativity break the scale and conformal invariance in massless and massive action. So, in
non-commutative space-time the massless and massive particles have same symmetry. 相似文献
17.
Miroslav Grmela 《Journal of statistical physics》2010,141(2):318-341
The state variables in the novel model introduced in this paper are the fields playing this role in the classical Landau-Tisza
model and additional fields of mass, entropy (or temperature), superfluid velocity, and gradient of the superfluid velocity,
all depending on the position vector and another tree dimensional vector labeling the scale, describing the small-scale structure
developed in 4He superfluid experiencing turbulent motion. The fluxes of mass, momentum, energy, and entropy in the position space as well
as the fluxes of energy and entropy in scales, appear in the time evolution equations as explicit functions of the state variables
and of their conjugates. The fundamental thermodynamic relation relating the fields to their conjugates is left in this paper
undetermined. The GENERIC structure of the equations serves two purposes: (i) it guarantees that solutions to the governing
equations, independently of the choice of the fundamental thermodynamic relation, agree with the observed compatibility with
thermodynamics, and (ii) it is used as a guide in the construction of the novel model. 相似文献
18.
The main purpose of this paper is to study time operators associated with generalized shifts and determined by the Haar and
Faber–Schauder bases on the space of continuous functions. It is given the characterization of the domains of the constructed
time operators and their scalings. It is also shown how scalings of time operators affect the dynamics of associated semigroups
of shift operators. 相似文献
19.
Arnaud Duperrin 《The European Physical Journal C - Particles and Fields》2009,59(2):297-334
The energy frontier is currently at the Fermilab Tevatron accelerator, which collides protons and antiprotons at a center-of-mass energy of 1.96 TeV. The luminosity delivered to the CDF and DØ experiments has now surpassed the 4 fb?1. This paper reviews the most recent direct searches for Higgs bosons and beyond-the-standard-model (BSM) physics at the Tevatron. The results reported correspond to an integrated luminosity of up to 2.5 fb?1 of Run II data collected by the two Collaborations. Searches covered include the standard model (SM) Higgs boson (including sensitivity projections), the neutral Higgs bosons in the minimal supersymmetric extension of the standard model (MSSM), charged Higgs bosons and extended Higgs models, supersymmetric decays that conserve or violate R-parity, gauge-mediated supersymmetric breaking models, long-lived particles, leptoquarks, compositeness, extra gauge bosons, extra dimensions, and finally signature-based searches. Given the excellent performance of the collider and the continued productivity of the experiments, the Tevatron physics potential looks promising for discovery with the coming larger data sets. In particular, evidence for the SM Higgs boson could be obtained if its mass is light or near 160 GeV. The observed (expected) upper limits are currently a factor of 3.7 (3.3) higher than the expected SM Higgs boson cross section at m H =115 GeV and 1.1 (1.6) at m H =160 GeV at 95% C.L. 相似文献
20.
Gravitational Perturbation of Garfinkle-Horowitz-Strominger Dilaton Black Hole and Quasinormal Modes
Kai Lin 《International Journal of Theoretical Physics》2010,49(11):2786-2792
We research gravitational perturbation of Garfinkle-Horowitz-Strominger dilaton black hole and its quasinormal modes by using
WKB approach proposed by Schutz, Will, Iyer and Konoplya. The quasinormal frequency with different angular momentum l is calculated in this paper. Our results show that, as the charge parameter b increase, both the real part and the absolute value of imaginary part of quasinormal frequency also increase, which means
that the effect of charge in Garfinkle-Horowitz-Strominger dilaton background spacetime lead to higher frequency gravitational
wave and the quasinormal modes damp at a rapider rate. 相似文献