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1.
Summary Semi-empirical formulations which have been proposed to describe the wind and potential temperature profiles are used to derive relationships between the gradient Richardson number, Ri, the finite-difference layer Richardson number, Rib, the surface layer Richardson number, Ris, and the bulk Richardson number,B, through the atmospheric surface layer. The theoretical analysis for stable conditions indicates that Ri (z 3)=Rib, wherez 3=(z 2z 1)/ln(z 2/z 1), andz 2;z 1=upper and lower levels at which temperature and wind speed are specified. It is also found that, during stable conditions, the wind profile power law exponent,p, is computed at the heightz 3, instead of the widely used geometric mean height,z m, between top (z 2) and bottom (z 1) of the layer considered.  相似文献   

2.
We consider associated production of squarks and gluinos with the lightest supersymmetric particle (LSP), or states nearly degenerate in mass with it. Though sub-dominant to pair production of color SU(3)-charged superpartners, these processes are directly sensitive to the wavefunction composition of the lightest neutralinos. Exploiting event-shape variables - including some introduced here for the first time - we are able to identify the composition of the LSP by selecting events involving a single high-pT jet recoiling against missing transverse energy. We illustrate the proposed technique on a set of benchmark cases and propose methods for applying these results in more realistic experimental environments.  相似文献   

3.
We define a derivation operation working on hybrid objects which are tensors under theEinstein group of coordinate transformations and under theLorentz group of transformations of reference systems. With these general covariant derivations we formulate the principle of the equivalence of theEinstein- and of theLorentz-covariant representations of the physical laws. This principle means the general covariant constance of the metric tetradsh i A (Weyl's lemma).  相似文献   

4.
We confront the discovery of a boson decaying into two photons, as reported recently by ATLAS and CMS, with the corresponding predictions in the Minimal Supersymmetric Standard Model (MSSM) and the Next-to-Minimal Supersymmetric Standard Model (NMSSM). We perform a scan over the relevant regions of parameter space in both models and evaluate the MSSM and NMSSM predictions for the dominant Higgs production channel and the photon–photon decay channel. Taking into account the experimental constraints from previous direct searches, flavor physics, electroweak measurements as well as theoretical considerations, we find that a Higgs signal in the two photon channel with a rate equal to, or above, the SM prediction is viable over the full mass range 123?M H ?127 GeV, both in the MSSM and the NMSSM. We find that besides the interpretation of a possible signal at about 125 GeV in terms of the lightest $\mathcal {CP}$ -even Higgs boson, both the MSSM and the NMSSM permit also a viable interpretation where an observed state at about 125 GeV would correspond to the second-lightest $\mathcal {CP}$ -even Higgs boson in the spectrum, which would be accompanied by another light Higgs with suppressed couplings to W and Z bosons. We find that a significant enhancement of the γγ rate, compatible with the signal strengths observed by ATLAS and CMS, is possible in both the MSSM and the NMSSM, and we analyse in detail different mechanisms in the two models that can give rise to such an enhancement. We briefly discuss also our predictions in the two models for the production and subsequent decay into two photons of a $\mathcal {CP}$ -odd Higgs boson.  相似文献   

5.
We study the Cauchy problem for the Whitham modulation equations for increasing smooth initial data. The Whitham equations are a collection of one-dimensional quasi-linear hyperbolic systems. This collection of systems is enumerated by the genus g=0,1,2, ... of the corresponding hyperelliptic Riemann surface. Each of these systems can be integrated by the so-called hodograph transformation introduced by Tsarev. A key step in the integration process is the solution of the Tsarev linear overdetermined system. For each g>0, we construct the unique solution of the Tsarev system, which matches the genus g+1 and g–1 solutions on the transition boundaries.  相似文献   

6.
A new investigation is done of the possibility of binding the “dodecatoplet”, a system of six top quarks and six top antiquarks, (t 6 6), using the Yukawa potential mediated by Higgs exchange. A simple variational method gives a upper bound close to that recently estimated in a mean-field calculation. It is supplemented by a lower bound provided by identities among the Hamiltonians describing the system and its subsystems.  相似文献   

7.
Using the Landau theory of phase transitions it has been shown that for a second order phase transition Ω/kBTc ? 0.01. and its isomorphs 4Ω/J1 ? 1 and for a first order transition Ω/kBTc ? 0.01.  相似文献   

8.
The general expression for the static permittivity ε(q, 0) of the Coulomb system in the region of small wave vectors was derived based on exact limit relations. The relation obtained describes the function ε(q, 0) in both “metal” and “dielectric” states of the Coulomb system. On this basis, the concept of the “true” dielectric is introduced and the definition of the “true” screening length was discussed. Exact relations were derived for the function ε(q, 0) in the region of small wave vectors q within the random phase approximation at an arbitrary degeneracy.  相似文献   

9.
We discuss a category of stable dark matter particles which are weakly interacting and related to the superstructure of the universe.These particles may be degenerate fermions and the bosons near a high temperature state.In both cases,we deduce that the particle mass is ~10-1eV and the absolute value of its chemical potential is <<10-1eV.This result is not in contradiction with the dip phenomena of the ultra high energy primary cosmic ray spectrum at ~1015eV and ~1018eV.  相似文献   

10.
The energies and the entropies of the spin-glass state and the paramagnetic state at T = 0 of the random-bond Ising mixture of the ferromagnetic bond (concentration p) and the antiferromagnetic bond (concentration 1 ? p) on the square lattice are calculated by the method of the square approximation in the simple version. A self-consistent relation that the partial trace of the normalized density matrix of the square cluster is equal to that of the vertex (tr(jkl??(4)(i,j,k,l) = ??(1)(i)) leads to an integral equation for the distribution function of the effective fields, and it is solved exactly at T = 0. The symmetric solution of the integral equation contains the paramagnetic state and two spin-glass states, SG1 and SG2. The energies and the entropies of these states are obtained as functions of the concentration p. The values of the energies per spin at p = 12 are -0.75|EF|, -0.72746|EF|, -0.72543|EF|, and correspond to a minimum, a saddle point, and a maximum, respectively, and the values of the entropies are 0, 0.082886kB, and 0.054457kB, respectively. The present results are compared with those of the pair approximation and discussed.  相似文献   

11.
Conductivity and superconductivity studies of amorphous [Sn1–y Cu y]1–x H x samples in connection with119Sn Mössbauer effect experiments on119Sn1–x H x give strong evidence that the observed increase of the superconducting transition temperatureT c in the Sn–H-system is caused by the stabilization of an amorphous structure. Thus the Sn–H-system is very similar to the Sn–Cu-system and no H-specific effect is needed to explain the increase ofT c.  相似文献   

12.
Intergalactic magnetic fields are assumed to have been spontaneously generated at the reheating stage of the early Universe, due to vacuum polarization of non-Abelian gauge fields at high temperature. The fact that the screening mass of this type of fields has zero value was discovered recently. A procedure to estimate their field strengths, B(T), at different temperatures is here developed, and the value B(T ew)∼1014 G at the electroweak phase transition temperature is derived by taking into consideration the present value of the intergalactic magnetic field strength, B 0∼10−15 G, coherent on the ∼1 Mpc scale. As a particular case, the standard model is considered and the field scale at high temperature is estimated in this case. Model-dependent properties of the phenomena under investigation are briefly discussed, too.  相似文献   

13.
14.
Preliminary probe experiments on the Filippov-type plasma focus with the energy E = 70 kJ and a current of about 1 MA show significant stray currents flowing near the insulator. To suppress them and optimize the discharge circuit, the main discharge chamber elements, i.e., the insulator, anode and cathode liner, were changed. As a result, a 30-fold increase in the setup neutron yield to Y n = 5· 1010 neutrons per pulse was detected.  相似文献   

15.
Using the GKS inequality Griffiths and Kaufman showed in [12] that the susceptibility in the Ising model on the hierarchical lattices is infinite forT>T c . In the present work we give an analytic calculation of the dominant singularity of the susceptibility whenh0 forT>T c . Moreover we analytically find the spontaneous magnetization forT<T c and prove that forT<T c the susceptibility is finite.  相似文献   

16.
The compressible and heat-conductive Navier-Stokes equation obtained as the second approximation of the formal Chapman-Enskog expansion is investigated on its relations to the original nonlinear Boltzmann equation and also to the incompressible Navier-Stokes equation. The solutions of the Boltzmann equation and the incompressible Navier-Stokes equation for small initial data are proved to be asymptotically equivalent (mod decay ratet –5/4) ast+ to that of the compressible Navier-Stokes equation for the corresponding initial data.  相似文献   

17.
It is shown that short range unitary transformations on the deuteron wave function of the super-soft-core potential of de Tourreil and Sprung, which fix the percentageD state of the deuteronP D, do not simultaneously fix the peak valueM of the electromagnetic quadrupole form factor of the deuteron within small error bars, even when the transformed wave functions are required to fit the quadrupole moment and the electric form factor of the deuteron within narrow limits. However there is a strong correlation betweenP D andM 2 for realistic interactions whose deuteron wave functions are suppressed at short distances.  相似文献   

18.
Themodel of degenerate weakly nonideal Bose gas is considered without the assumption on the C-number nature of creation and annihilation operators of particles in the zero-momentum state. It was shown that the “density-density” Green’s function pole defines the Bogolyubov spectrum of phonon-roton-type collective excitations. The single-particle excitation spectrum is characterized by the gap whose value is defined by the particle density in the “condensate”.  相似文献   

19.
The gravitational Szekeres differential system is completely integrable with two rational first integrals and an additional analytical first integral. We describe the dynamics of the Szekeres system when one of these two rational first integrals is negative, showing that all the orbits come from the infinity of R4 and go to infinity.  相似文献   

20.
New polarimeter based on the asymmetry measurement in dp-elastic scattering has been constructed at internal target at Nuclotron (JINR). The result on the deuteron analyzing powers A y , A yy and A xx in the deuteron-proton (dp) elastic scattering at the energies of 880 and 2000 MeV are presented. They are compared with different theoretical approaches.  相似文献   

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