摘要：
Based on the extended Ginzburg-Landau model, it is shown that the dependences of the scaled factorial moments In F-q on phase space intervals are different for first- and second-order QGP phase transitions. When In F-q are fitted to polynomials of X = delta(1/3), the relative sign between the fitted coefficients can be used to judge the order of phase transitions.
期刊：
EUROPEAN PHYSICAL JOURNAL A,1999年5(4):429-440 ISSN：1434-6001
通讯作者：
Adamovich, MI
作者机构：
PN Lebedev Phys Inst, Moscow 117924, Russia.;Inst High Energy Phys, Alma Ata, Kazakhstan.;Acad Sinica, Inst High Energy Phys, Beijing, Peoples R China.;Inst Space Sci, Bucharest, Romania.;Panjab Univ, Dept Phys, Chandigarh 160014, India.
摘要：
The experimental data on the interactions of 10.6A GeV gold nuclei in nuclear emulsions are analyzed with particular emphasis of target separation interactions and study of critical exponents. Charged fragment moments, conditional moments as well as two and three - body asymmetries of the fast moving. projectile particles are determined in terms of the total charge remaining bound in the multiply charged projectile fragments. Some differences in the average yields of helium nuclei and heavier fragments are observed, which may be attributed to a target effect. However, two and three-body asymmetries and conditional moments indicate that the breakup mechanism of the projectile seems to be independent of target mass. We looked for evidence of critical point observable in finite nuclei by study the resulting charged fragments distributions. We have obtained the values for the critical exponents γ, β and τ and compare our results with those at lower energy experiment (1.0A GeV data). The values suggest that a phase transition like behavior, is observed.
关键词：
05.70.Jk critical point phenomena;64.60.-i general studies of phase transitions
摘要：
We reexamine the range of validity of finite-size scaling in the
$${\varphi ^4}$$
lattice model and the
$${\varphi ^4}$$
field theory below four dimensions. We show that general renormalization-group arguments based on the renormalizability of the
$${\varphi ^4}$$
theory do not rule out the possibility of a violation of finite-size scaling due to a finite lattice constant and a finite cutoff. For a confined geometry of linear size L with periodic boundary conditions we analyze the approach towards bulk critical behavior as
$$L \to \infty $$
at fixed
$$\xi $$
for T > Tcwhere
$$\xi $$
is the bulk correlation length. We show that for this analysis ordinary renormalized perturbation theory is sufficient. On the basis of one-loop results and of exact results in the spherical limit we find that finite-size scaling is violated for both the
$${\varphi ^4}$$
lattice model and the
$${\varphi ^4}$$
field theory in the region
$$L \gg \xi $$
. The non-scaling effects in the field theory and in the lattice model differ significantly from each other.
摘要：
Starting from the shell model configurations, valence nucleon effective interactions and fermion E2 transition operator, a microscopic approach of sdglBM- 2 is used to calculate the energy spectra, E2 transitions, and binding energies for 48,52,56Cr. The results fit the experimental data quite well.
期刊：
SCIENCE IN CHINA SERIES A-MATHEMATICS,1999年42(8):845-851 ISSN：1006-9283
通讯作者：
Wang, XR
作者机构：
[Wang, XR] Huazhong Normal Univ, Inst Particle Phys, Wuhan 430070, Peoples R China.;Acad Sinica, Inst High Energy Phys, Beijing 100039, Peoples R China.;China Inst Atom Energy, Beijing 102413, Peoples R China.;Free Univ Berlin, FB Phys, D-14195 Berlin, Germany.
通讯机构：
[Wang, XR] H;Huazhong Normal Univ, Inst Particle Phys, Wuhan 430070, Peoples R China.
关键词：
RELATIVISTIC;HEAVY-ION;COLLISION;GREY;particle;EMULSION;experiments;LUCIAE;model.;grey particle;emulsion experiments;LUCIAE model
摘要：
The hadronic and string cascade model and the corresponding event generator LUCIAE are used to study systematically the production of the grey particles in (14.6, 60 and 200A GeV)0 + Em, (2004 GeV)Si + Em, (200A GeV)S + Em and (11.6A GeV)Au + Em reactions. The dependences of the mean multiplicity, the multiplicity distributions and the polar angular distributions of the grey particles on the incident energy, the projectile mass and the collision centrality observed in emulsion experiments, respectively, are all reproduced by LUCIAE calculations. In addition the effects of the rescattering on the grey particle production are also investigated.
摘要：
Transverse momentum event-by-event fluctuations are studied within the string-hadronic model of high energy nuclear collisions, LUCIAE. Data on non-statistical PT fluctuations in p+p interactions are reproduced. Fluctuations of similar magnitude are predicted for nucleus-nucleus collisions, in contradiction to the preliminary NA49 results. The introduction of a string clustering mechanism (Firecracker Model) leads to a further, significant increase of PT fluctuations for nucleus-nucleus collisions. Secondary hadronic interactions, as implemented in LUCIAE, cause only a small reduction of PT fluctuations.
摘要：
Hadronic multiplicity distributions in small bins are studied within the Ginzburg-Landau description for quark-hadron phase transitions. Direct comparison of the distributions with Poisson ones (with the same averages) is made in the light of dynamical factors d<sub>q</sub> for the distributions and ratios D<sub>q</sub>, equivalent d<sub>q</sub>/ d<sub>1</sub>,. Scaling behavior between D<sub>q</sub>' s is found, which can be used to detect the formation of quark-gluon plasma. The same method can be used in the analysis of other processes without phase transition.
作者机构：
[Hu, XM; Peng, JS] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Hu, XM] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
关键词：
激光;噪声;双量子跳动
摘要：
Noise squeezing of intensity difference between the pair of sum modes may be generated in a cascade laser of A and V quantum-beats. The best achievable squeezing is up to 50% below the shot noise limit. This new kind of squeezed lasers has potential for quantum communications and precision measurements.
摘要：
In this paper we investigate the quantum statistical properties in a cascade laser system with the lower transition being in a #LAMBDA# quantum-beat configuration. It is shown that a type of three-mode squeezing may be generated. The fluctuations of the intensity difference between the sum-mode from the quantum-beat and the cascade single mode may be reduced below the shot-noise limit. The best achievable noise reduction is up to 50%. Good squeezing occurs when the sum mode and the cascade single mode have normalized intensities much larger than unity and the intensity difference is much smaller than the respective intensity.
作者机构：
[Hu, XM; Peng, JS] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Hu, XM] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
关键词：
European Physical Journal D;Atomic Physics;Molecular Physics;Optical physics;Plasma Physics;journal;EPJ
摘要：
On the basis of the nondegenerate Λ quantum-beat laser model, we introduce a coherent field which drives the transition between the upper lasing level and an auxiliary level. We demonstrate that such a four-level system can produce squeezed two-mode lasei without and with inversion. When the laser is operated well above threshold, the intensity fluctuation in the average mode is reduced below the shot noise with an optimum Mandel parameter Q = -1/2. At the same time, the noises in the relative amplitude and the relative phase drop to their vaccum noise levels. Fuithermore, regardless of inversion, noninversion, and transition between inversion and noninversion, the optimum Mandel Q parameter of Q = -1/2 is retained when the system operates well above threshold. A simple physical explanation of the squeezing mechanism for two-mode squeezing is given.
