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1.
The behaviour of Levy index?? in various phase space dimensions is studied. The reason for the violation of Levy stable condition at three-dimension observed in experiment is investigated. It is shown that the apparent violation of Levy stable condition may be due to the wrong isotropic analysis for the highly anisotropic phase space of multiparticle production.  相似文献   

2.
The behaviour of Levy index 7 in various phase space dimensions is studied. The reason for the violation of Levy stable condition at three-dimension observed in experiment is investigated. It is shown that the apparent violation of Levy stable condition may be due to the wrong isotropic analysis for the highly anisotropic phase space of multiparticle production.  相似文献   

3.
In the present work target excitation dependence of the self-similar cascading rate has been studied in detail in the framework of Levy stable law using the experimental data of pions obtained from π ?-AgBr interactions at 350 GeV/c. TheLevy indices µ measured from the analysis fulfill the requirement of the Levy stable region 0 ? µ ? 2. The study gives an evidence of self-similar cascading mechanism responsible for multiparticle production. The different values of µ indicate different rates of cascading for different degrees of target excitation. Moreover, the values of universal scaling exponent (ν) obtained from Ginzburg-Landau theory indicate that no clear evidence of second-order phase transition has been found in the interaction.  相似文献   

4.
The possibility of explicit CP violation is studied in a supersymmetric model proposed by Dine, Seiberg, and Thomas, with two effective dimension-five operators. The explicit CP violation may be triggered by complex phases in the coefficients for the dimension-five operators in the Higgs potential, and by a complex phase in the scalar top quark masses. Although the scenario of explicit CP violation is found to be inconsistent with the experimental data at LEP2 at tree level, it may be possible at the one-loop level. For a reasonable parameter space, the masses of the neutral Higgs bosons and their couplings to a pair of Z bosons are consistent with the LEP2 data, at the one-loop level.  相似文献   

5.
The power law relation between higher order and second order scaled factorial moments is studied in one dimensional pseudo-rapidity phase (η) space in the interactions of 32S beam with CNO, AgBr and Emulsion at incident energy of 200 AGeV. Observation for such a power law may indicate a self similar cascade mechanism in multiparticle production process. The values of slope, βq are found to be independent of target size. The value of the scaling exponent υ = 1.412 obtained is higher than the critical value υ = 1.304, indicating that no second order phase transition exists in our data. The ratio of anomalous fractal dimensions, dq/d2 is found to increase with increase in the order of moments, q. The dependence of dq/d2 on q indicates a multifractal structure and the presence of self-similar cascading mechanism in our data. The dq/d2 values are well described by the Levy-stable distribution with Levy index μ = 1.562 which is consistent with and lies within the Levy stable region (0 ≤ μ ≤ 2). The multifractal spectrum is concave downward with a maximum at q = 0. The decrease in Dq with increasing q shows that there is a self affine multifractal behaviour in multiparticle production in our data.  相似文献   

6.
The Levy stable analysis for random cascade model is performed. The Levy stable index μ ofa-model is obtained by both Monte-Carlo simulation and analytical calculation. It is foundthat μ is increasing when the fluctuation becomes weaker, and vice versa, just as expected.It is shown that the Levy stable index of α-model depends mainly upon the model parameter α. Its weak dependence on the number λ of branches in each elementary splitting is due tothe normalization of probability in each step. The possible reason of the Levy stable indexgreater than 2 found experimentally is briefly discussed.  相似文献   

7.
The random walk simulation of a Levy flight shows a linear relation between the mean square displacement 〈r2〉 and time. We have analyzed different aspects of this linearity. It is shown that the restriction of jump length to a maximum value (lm) affects the diffusion coefficient, even though it remains constant for lm greater than 1464. So, this factor has no effect on the linearity. In addition, it is shown that the number of samples does not affect the results. We have demonstrated that the relation between the mean square displacement and time remains linear in a continuous space, while continuous variables just reduce the diffusion coefficient. The results also imply that the movement of a Levy flight particle is similar to the case in which the particle moves in each time step with an average jump length 〈l〉. Finally, it is shown that the non-linear relation of the Levy flight will be satisfied if we use a time average instead of an ensemble average. The difference between the time average and ensemble average results shows that the Levy distribution may be a non-ergodic distribution.  相似文献   

8.
The parameters at which the maximally entangled two-particle state appears in the system of two ideal electronic Mach-Zehnder interferometers are known. In this work, the operation of nonideal devices with finite scattering in splitters and with reflection in the region of the Coulomb Interaction has been considered. It has been shown that, under the condition of postselection of experimental results, these factors can increase the observed Bell parameter to values exceeding Cirel’son’s (or Tsirelson’s) bound equal to 2√2 up to the mathematical limit equal to 4. A simple postselective measurement scheme providing B = 4 has been described. Although the results of such measurements are not as fundamental as the observation of the violation of Bell’s inequality, they can indirectly indicate the existence of an entangled state in the system. The measurement system is more stable against fluctuations of the phase than a system without postselection. Furthermore, it has been found that the proposed system is optimal for investigation of cross correlations between interferometers in the dc regime (beyond the paradigm of the violation of Bell’s inequality) because they cannot be generated by coordinated fluctuations of Aharonov-Bohm phases.  相似文献   

9.
10.
《Physics letters. A》1997,236(3):173-176
It is shown that Bell's proof of the violation of local realism in phase space is incorrect. Bell's experiment is based upon position measurements of free particles. A violation can be derived even for a nonnegative Wigner distribution, which in this case acts as a local classical model.  相似文献   

11.
Ring-like and jet-like events produced in 16O-AgBr interactions at 60 AGeV are analyzed in terms of multifractal G-moment method and factorial moment method in both η space and ? space for emitted pions. Further, the Levy indices and multifractal specific heat c have been calculated. The results clearly indicate that μ and c both are different in ring-like and jet-like events depicting different mechanism in the production process.  相似文献   

12.
The influence of a Lorentz violation on soliton solutions generated by a system of two coupled scalar fields is investigated. Lorentz violation is induced by a fixed tensor coefficient that couples the two fields. The Bogomol’nyi method is applied and first-order differential equations are obtained whose solutions minimize the energy and are also solutions of the equations of motion. The analysis of the solutions in phase space shows how the stability is modified with the Lorentz violation. It is shown explicitly that the solutions preserve linear stability despite the presence of Lorentz violation. Considering Lorentz violation as a small perturbation, an analytical method is employed to yield analytical solutions.  相似文献   

13.
In this study, we apply two methods to consider the variation of massive black holes in both normal and extended thermodynamic phase spaces. The first method considers a charged particle being absorbed by the black hole, whereas the second considers a shell of dust falling into it. With the former method, the first and second laws of thermodynamics are always satisfied in the normal phase space; however, in the extended phase space, the first law is satisfied but the validity of the second law?of?thermodynamics depends upon the model parameters. With the latter method, both laws are valid. We argue that the former method's violation of the second law of thermodynamics may be attributable to the assumption that the change of internal energy of the black hole is equal to the energy of the particle. Finally, we demonstrate that the event horizon always ensures the validity of weak cosmic censorship in both phase spaces; this means that the violation of the second law of thermodynamics, arising under the aforementioned assumption, does not affect the weak cosmic censorship conjecture. This further supports our argument that the assumption in the first method is responsible for the violation and requires deeper treatment.  相似文献   

14.
Following a suggestion of Salam and Strathdee that CP violation disappears and the Cabbibo angle vanishes at high magnetic fields we infer that no CP (or T) violation should be observed in nuclear beta decays and that stable hypernuclei are in principle possible.  相似文献   

15.
Based on the output saturation of classcial bistable stochastic resonance (CBSR), a new type of piecewise nonlinear bistable stochastic resonance (PNBSR) system is constructed. The mean signal-to-noise ratio gain is regarded as an index to measure the stochastic resonance phenomenon. The laws for the resonant output of piecewise nonlinear bistable system governed by l, c, a, b and D of Levy noise are explored under different characteristic index α and symmetry parameter β of Levy noise. The results show that the output of PNBSR system has increased 4?dB by comparing with the output signal-to-noise ratio of CBSR system. And the stochastic resonance phenomenon can be induced by adjusting the piecewise nonlinear system's parameters under any α or β of Levy noise. The interval of the parameters of system which induces good stochastic resonance is roughly the same. And the output signal waveform of resonance is very similar to the input signal waveform, which has some reference value for the signal recovery. Moreover, we can find the good stochastic resonance interval of the system parameters do not change with D of Levy noise under the different noise intensity D of Levy noise. On the basis of this, adjusting the intensity amplification factor D of Levy noise, which induces good stochastic resonance, and the interval does not change with α or β. At last, the piecewise nonlinear bistable system is applied to detect bearing fault signals, which achieves better performance compared with the classical bistable system.  相似文献   

16.
17.
We study the gravitational effects of a planar domain wall on quantum fluctuations of a massless scalar field during inflation. By obtaining an exact solution of the scalar field equation in de-Sitter space, we show that the gravitational effects of the domain wall break the rotational invariance of the primordial power spectrum without affecting the translational invariance. The strength of rotational violation is determined by one dimensionless parameter β, which is a function of two physical parameters, the domain wall surface tension σ and cosmological constant Λ. In the limit of small β, the leading effect of rotational violation of the primordial power spectrum is scale-invariant.  相似文献   

18.
The Migdal renormalization group approach is applied to a finite temperature lattice gauge theory. Imposing the periodic boundary condition in the timelike orientation, the phase structure of the finite temperature lattice gauge system with a gauge groupG in (d+1)-dimensional space is determined by two kinds of recursion equations, describing spacelike and timelike correlations, respectively. One is the recursion equation for ad-dimensional gauge system with the gauge groupG, and the other corresponds to ad-dimensional spin system for which the effective theory is described by the nearest neighbor interaction of the Wilson lines. Detailed phase structure is investigated for theSU(2) gauge theory in (3+1)-dimensional space. Deconfinement phase transition is obtained. Using the recursion equation for the three dimensional spin system of the Wilson lines, it is shown that the flow of the renormalization group trajectories leads to a phase transition of the three dimensional Ising model.  相似文献   

19.
We investigate the possibility of parity being spontaneously violated in QCD at finite baryon density and temperature. QCD is approximated by a generalized σ model with two isomultiplets of scalars and pseudoscalars. The interaction with the chemical potential is introduced via the coupling to constituent quark fields as nucleons are not considered as point-like degrees of freedom in our approach. This mechanism of parity violation is based on interplay between lightest and heavier degrees of freedom and it cannot be understood in simple models retaining the pion and nucleon sectors solely. We argue that, in the appropriate environment (dense and hot nuclear matter of a few normal densities and moderate temperatures), parity violation may be the rule rather than the exception and its occurrence is well compatible with the existence of stable bound state of normal nuclear matter. We prove that the so-called ‘chiral collapse’ never takes place for the parameter region supporting spontaneous parity violation.  相似文献   

20.
An explicit violation of the general gauge invariance/relativity is adopted as the origin of dark matter and dark energy in the context of gravitation. The violation of the local scale invariance alone, with the residual unimodular one, is considered. Besides the four-volume preserving deformation mode—the transverse-tensor graviton—the metric comprises a compression mode—the scalar graviton, or the systolon. A unimodular invariant and general covariant metric theory of the bimode/scalar-tensor gravity is consistently worked out. To reduce the primordial ambiguity of the theory a dynamical global symmetry is imposed, with its subsequent spontaneous breaking revealed. The static spherically symmetric case in empty space, except possibly for the origin, is studied. A three-parameter solution describing a new static space structure—the dark lacuna—is constructed. It enjoys the property of gravitational confinement, with the logarithmic potential of gravitational attraction at the periphery, and results in asymptotically flat rotation curves. Comprising a super-massive dark fracture (a scalar-modified black hole) at the origin surrounded by a cored dark halo, the dark lacunas are proposed as a prototype model of galaxies, implying an ultimate account for the distributed non-gravitational matter and putative asphericity or rotation.  相似文献   

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