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1.
It is observed that a simple mass formula of the formm =¯mQ 2(exp) is wholly consistent with experimental measurements and quark model estimates for all 12 fundamental fermions. Here¯m = 433.3 MeV is an input (mean fermion mass) constant,Q is the charge number of the lepton or quark, and is a real root of a quartic equation that brings in a principal quantum numbern (= 0, 1, 2, 3). The charged lepton masses are given accurately to within 0.3 of 1%, all neutrino masses are zero, and the top mass is predicted by the formula to be close tom t = 163.6 GeV.  相似文献   

2.
It has recently been shown that time-like spherical collapse of a physical fluid in General Relativity does not permit formation of trapped surfaces. This result followed from the fact that the formation of a trapped surface in a physical fluid would cause the time-like world lines of the collapsing fluid to become null at the would-be trapped surface, thus violating the Principle of Equivalence in General Theory of Relativity (GTR). For the case of the spherical collapse of a physical fluid, the no trapped surface condition 2GM(r, t)/R(r, t) c 2<1 was found to be required to be satisfied in all regions of spacetime, where R(r, t) is the invariant circumference variable, r is a co-moving radial coordinate and M(r, t) is the gravitational mass confined within the radius r. The above result was obtained by treating the problem from the viewpoint of an internal co-moving observer at radius r. The boundary of the fluid at r s=R s(r s, t) must also behave in a similar manner, and an external stationary observer should be able to obtain a similar no trapped surface relationship. Accordingly, we generalize this analysis by studying the problem of a time-like collapsing radiating plasma from the point of view of the exterior stationary observer. We find the Principle of Equivalence implies that the physical surface surrounding the plasma must obey 1/(1+z s)>0, where z s is the surface red shift seen by a zero-angular momentum observer. When this condition is applied to the first integral of the time-time component of the Einstein equation, it leads to the no trapped surface condition 2GM(r s, t)/R(r s, t) c 2<1 consistent with the condition obtained above for the interior co-moving metric. The Principle of Equivalence enforces the no trapped surface condition by constraining the physics of the general relativistic radiation transfer process in a manner that requires it to establish and maintain an Eddington limited secular equilibrium on the dynamics of the collapsing radiating surface so as to always keep the physical surface of the collapsing object outside of its Schwarzschild radius. The important physical implication of the no trapped surface condition is that galactic black hole candidates GBHC do not possess event horizons and hence do possess intrinsic magnetic fields. In this context the spectral characteristics of galactic black hole candidates offer strong evidence that their central nuclei are highly red-shifted Magnetospheric Eternally Collapsing Objects (MECO) within the framework of General Relativity.  相似文献   

3.
Theq-state Potts model (both scalar and gauge versions) is rewritten, with the help of the duality transformation, into a form of the Pirogov-Sinai theory with noninteracting contours that can be controlled by cluster expansions onceq is large enough. This is then used in a new proof of the existence of a unique transition (inverse) temperature t , where the mean internal energy is discontinuous. Moreover, we prove for the scalar model (again forq large enough) that there are discontinuities at t of the magnetization and of the mass gap, with the magnetization vanishing below t and the mass gap vanishing above t . We also show that the surface tensions between ordered stable phases are strictly positive up to t , and the surface tension between an ordered phase and the disordered one is strictly positive at t . For the three-dimensional gauge model, the Wilson parameter exhibits a direct transition from an area law decay (quark confinement) to a perimeter law decay (deconfinement).On leave from ENS Rabat, Morocco.  相似文献   

4.
We discuss a heurisitic model of gravitational vacuum as a set of virtual, radiating planckeons, particles with Planck size (L) and mass (/cL). Combined with Dirac's large number hypothesis, this gives the minimum universe scale factor valuea min10–13 cm, the strong interaction length (a = L just whena=a min ). Taking this state as an initial one using standard quantum techniques, we consider particle creation by planckeons. Under some reasonable assumptions we obtain the present number of particles with nucleon mass close to observations,N 1080. A criterion for gravitational stability of particles is formulated and some applications of the corresponding mass formula are considered. In particular, Fermi's weak interaction constant is expressed in terms ofa andL and a finite value for the neutrino mass is obtained.  相似文献   

5.
Existing data from precision tests of the electroweak standard model at LEP, the -colliders andvN-scattering experiments constrain the mass of the top quark toM t =144 –26–21 +23+19 GeV, where the central value and first error refer to a Higgs mass value of 300 GeV. The second error shows the variation ofM t for Higgs mass values spanning the range 50M H(GeV)<1000. the=" present=" apparent=" sensitivity=" of=" the=" data=" to=" the=" value=" of=" the=" higgs=" mass=" is=" investigated.=" future=" data=" from=" lep=" will=" significantly=" tighten=" the=" bounds=">M t . Limits onM H however will remain of order M H/M H2 without an independent measurement ofM t .  相似文献   

6.
A new model is proposed to a collapsing radiating star consisting of an isotropic fluid with shear viscosity undergoing radial heat flow with outgoing radiation. In a previous paper we have introduced a function time dependent into the g rr , besides the time dependent metric functions and . The aim of this work is to generalize this previous model by introducing shear viscosity and compare it to the non-viscous collapse. The behavior of the density, pressure, mass, luminosity and the effective adiabatic index is analyzed. Our work is compared to the case of a collapsing shearing fluid of a previous model, for a star with 6 . The pressure of the star, at the beginning of the collapse, is isotropic but due to the presence of the shear the pressure becomes more and more anisotropic. The black hole is never formed because the apparent horizon formation condition is never satisfied. An observer at infinity sees a radial point source radiating exponentially until reaches the time of maximum luminosity and suddenly the star turns off. The effective adiabatic index has a very unusual behavior because we have a non-adiabatic regime in the fluid due to the heat flow.  相似文献   

7.
We present a generalization of Gerstenhaber's theory of deformations. We no longer assume that the deformation parameter t acts in its usual free and symmetric way on the elements of the original algebra A, but in the following manner: t · a = (a)t and a · t = (a)t, where and are endomorphisms of A. We develop the cohomological framework adapted to these deformations.  相似文献   

8.
A diffusion model of metal surface modification by plasma nitriding has been developed. This model takes into account the erosion effects at the plasma/solid interface occurring due to the ion bombardment of the surface. For constant sputtering rate, which is the usual situation during plasma nitriding, the growth of the sub-layers is well described by the analytical expressiong(t) =g 0,f –1 (t/t 0), whereg(t) is the sub-layer thickness at timet,g 0 andt 0 are parameters which depend on the treated material and plasma characteristics,f –1 is the inverse of the function — In(1 - x) + x), 0 x 1. Under negligible erosion effects, the expression forg(t) reduces to the parabolic law. The diffusion zone (substratum) growth does not follow the parabolic law as well. However, the deviation occurs after long plasma nitriding time. The model can be used for experimentally determining the effective diffusion coefficients and the erosion rate during plasma nitriding of metal surfaces.  相似文献   

9.
We analyze the limiting behavior of the densities A(t) and B(t), and the random spatial structure(r) = ( A(t)., B(t)), for the diffusion-controlled chemical reaction A+Binert. For equal initial densities B(0) = b(0) there is a change in behavior fromd 4, where A(t) = B(t) C/td/4, tod 4, where A(t) = b(t) C/t ast ; the termC depends on the initial densities and changes withd. There is a corresponding change in the spatial structure. Ind < 4, the particle types separate with only one type present locally, and , after suitable rescaling, tends to a random Gaussian process. Ind >4, both particle types are, after large times, present locally in concentrations not depending on type or location. Ind=4, both particle types are present locally, but with random concentrations, and the process tends to a limit.  相似文献   

10.
We explicitly calculate the free energy of the general solvableN-state chiral Potts model in the scaling region, forT<T c . We do this from both of the two available results for the free energy, and verify that they are mutually consistent. Ift=T c –T, then we find that - c /t has a Taylor expansion in powers oft 2/N (together with higher-order non-scaling terms of ordert, ort logt).  相似文献   

11.
The expression of a time-dependent cosmological constant 1/t2 is interpreted as the energy density of a special type of the quaternionic field which is coupled to its own field energy. The general solution of the corresponding field equations yields the field energy which contains an integration constant t 0. If t 0 > 0 then the cosmological constant exhibits no initial singularity at t = 0. In the early universe the black energy associated with can be made small enough for the structure forming of galaxies getting, however, its observational value at the present time.  相似文献   

12.
It is shown that a Universe with a time-varying gravitational constantG necessarily implies creation if the rest mass of matter particlesm p is constant. In this case, from Einstein's field equations, the conditions for energy-momentum propagation are ·(GT v ) from which matter and photon propagation equations are derived. Free matter particle propagation is not affected by creation that is given byGN pmp=const, whereN p is the number of matter particles within a proper volume. This relation introduces explicitly the rest mass of the Universe into the field equations. Free photon propagation is affected by creation that is given byGT v R=const, whereN is the number of photons within a proper volume, which is the cosmic red shift law. Conservation of the cosmic background photon distribution determines photon creation asG 3 N 4 . The results are applied to the caseG t –1 equivalent toN p ÷ t.It is found that at an aget=1, 0–40 t o, of the order light takes to travel a proton size, Planck's units become of the order of the proton's massm p, sizer p, and timer p/c. Hence, matter particles at this age are quantum black holes. Evaporation of these quantum black holes at this age gives a background blackbody radiation that, red shifted to present timet 0, gives the present cosmic microwave background.A cosmological model of the Friedmann type is constructed. The red shift versus distance relation is derived taking into account creation. Using a Hubble's constantH obs=50 km sec–1 Mpc–1 and a deceleration parameterq obs=1.0 the model is of the typek=1 and gives a present aget 0=6.81×109 yr, consistent with Uranium model ages. Thus, the three results for the age of the Universe, i.e., radioactive decay, Hubble's constant, and stellar evolution are brought together in this creation model. The matter-dominated era occurs fort>7.6×10–3 t 0, while the radiation-dominated era occurs for 7.6×10–3 t o>t>10–40 t o. The origin of the Universe is placed at this last limit, which is Planck's time at the corresponding G, consisting of quantum black holes at a temperature Ti=3×1011K.  相似文献   

13.
The semi-infinite Toda lattice is the system of differential equations d n (t)/dt = n (t)(b n+1(t) – b n (t)), db n (t)/dt = 2( n 2(t) – n–1 2(t)), n = 1, 2, ..., t > 0. The solution of this system (if it exists) is a pair of real sequences n (t), b n (t) which satisfy the conditions n (0) = n ,, b n (0) = b n , where n > 0 and b n are given sequences of real numbers. It is well known that the system has a unique solution provided that both sequences n and b n are bounded. When at least one of the known sequences n and b n is unbounded, many difficulties arise and, to the best of our knowledge, there are few results concerning the solution of the system. In this letter we find a class of unbounded sequences n and b n such that the system has a unique solution. The results are illustrated with a typical example where the sequences i (t), b i (t), i = 1, 2, ... can be exactly determined. The connection of the Toda lattice with the semi-infinite differential-difference equation d2/dt 2 log h n = h n+1 + h n–1 – 2h n , n = 1, 2, ... is also discussed and the above results are translated to analogous results for the last equation.  相似文献   

14.
The Hubbard modelH=–tc x c y +U n x n x withN electrons and periodic boundary condition is studied onv-dimensionalL 1 × ... ×L v lattices. It is shown that for any value ofU there is no ground state with maximal spin (S=N/2) in the following cases: (i) v (v2) at low electron densities; with one hole ift>0 andL i is odd for somei; with two holes ift<0, or ift>0 and all theL i are even. (ii) Thebcc lattice at low densities; with two holes ift<0, or ift>0 and all theL i are even; with 2, ..., 6 holes ifL i =L andt<0, or ift>0 andL is even. (iii) The triangular lattice at densities near 0 and 1 ift>0; with two holes ift<0; with 2, 3, 4 holes ift<0 andL 1=L 2. (iv) Thefcc lattice at densities near 0 and 1 ift>0; with two holes ift<0. Some results for the one dimensional model are also presented.  相似文献   

15.
We develop a method for precise asymptotic analysis of partition functions near first-order phase transitions. Working in a (+1)-dimensional cylinder of volumeL×...×L×t, we show that leading exponentials int can be determined from a simple matrix calculation providedtv logL. Through a careful surface analysis we relate the off-diagonal matrix elements of this matrix to the surface tension andL, while the diagonal matrix elements of this matrix are related to the metastable free energies of the model. For the off-diagonal matrix elements, which are related to the crossover length from hypercubic (L=t) to cylindrical (t=) scaling, this includes a determination of the pre-exponential power ofL as a function of dimension. The results are applied to supersymmetric field theory and, in a forthcoming paper, to the finite-size scaling of the magnetization and inner energy at field and temperature driven first-order transitions in the crossover region from hypercubic to cylindrical scaling.Research partially supported by the A. P. Sloan Foundation and by the NSF under DMS-8858073Research partially supported by the NSF under DMS-8858073 and DMS-9008827  相似文献   

16.
The Euclidean field theory of the Sine-Gordon model (SG) is investigated by using methods of statistical physics. The SG model is shown to be the continuum limit of the ferromagnetic Harmonic Rotator model (HR) which itself is equivalent to a classical Coulomb plasma of unit charges on a lattice. Using our recent results for the latter models in all Euclidean dimensionsD we determine the existence of the SG field theory in terms of the HR parameters, temperaturet and magnetic fieldB. The following results are derived: 1. InD=1 the SG exists neart=B=0; the quantum theory in zero space dimensions is just the Mathieu equation as Schrödinger equation. 2. ForD>2 the SG field theory exists for allt nearB=0. The theory is actually constructed and is equivalent to a free massive scalar theory. 3. In the most interesting case ofD=2 the SG field theory exists for allt<t=8 nearB=0, it does not exist fortt. All necessary renormalizations are performed and all necessary subtractions are obtained in closed form which proves that the theory is superrenormalizable when it exists. We also discuss the relations between the structure of the particle spectrum of the SG, the phase transitions of the HR, and the binding properties of the classical Coulomb charges.  相似文献   

17.
The general study of random walks on a lattice is developed further with emphasis on continuous-time walks with an asymmetric bias. Continuous time walks are characterized by random pauses between jumps, with a common pausing time distribution(t). An analytic solution in the form of an inverse Laplace transform for P(l, t), the probability of a walker being atl at timet if it started atl o att=0, is obtained in the presence of completely absorbing boundaries. Numerical results for P(l, t) are presented for characteristically different (t), including one which leads to a non-Gaussian behavior for P(l, t) even for larget. Asymptotic results are obtained for the number of surviving walkers and the mean l showing the effect of the absorption at the boundary.This study was partially supported by ARPA and monitored by ONR(N00014-17-0308).  相似文献   

18.
We consider the diffusion of a particle at Xt in a drift field derived from a smooth potential of the formV+B, whereV is periodic andB is a bump of compact support. With no bump,B=0, the mean squared displacementE(t) E |X t – X0|2 =D(V)t +C +O(e t ),>0, in any dimension. WhenB0, we establish in one dimension the asymptotic expansion , 0, ast. Our analysis relies on the Nash estimates developed in previous work for the transition density of the process and their consequences for the analytic structure,of the Laplace transform ofE(t).  相似文献   

19.
We estimate the electro-magnetic mass differences of strange, charm b- and t-quark meson isodoublets in a parametrized potential model including the gluonic hyperfine splitting term explicitly. The numerical results of the mass differences for strange, charm and b-quark mesons agree well with the available experimental values. We predict the electromagnetic mass differences of t-quark mesons: .  相似文献   

20.
P K Sahu  A Ohnishi  M Isse  N Otuka  S C Phatak 《Pramana》2006,67(2):257-268
We present the analysis of elliptic flow at =130 A GeV energy in a hadron-string cascade model. We find that the final hadronic yields are qualitatively described. The elliptic flow v 2 is reasonably well-described at low transverse momentum (p t<1 GeV/c) in mid-central collisions. On the other hand, this model does not explain v 2 at high p t or in peripheral collisions and thus generally, it underestimates the elliptic flow at RHIC energy.  相似文献   

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