20,755 research outputs found
Pressure and intermittency in passive vector turbulence
We investigate the scaling properties a model of passive vector turbulence
with pressure and in the presence of a large-scale anisotropy. The leading
scaling exponents of the structure functions are proven to be anomalous. The
anisotropic exponents are organized in hierarchical families growing without
bound with the degree of anisotropy. Nonlocality produces poles in the
inertial-range dynamics corresponding to the dimensional scaling solution. The
increase with the P\'{e}clet number of hyperskewness and higher odd-dimensional
ratios signals the persistence of anisotropy effects also in the inertial
range.Comment: 4 pages, 1 figur
The H molecular ion: a solution
Combining the WKB expansion at large distances and Perturbation Theory at
small distances it is constructed a compact uniform approximation for
eigenfunctions. For lowest states 1s\si_{g} and 2p\si_{u} this
approximation provides the relative accuracy (5 s.d.) for
any real in eigenfunctions and for total energy it gives 10-11 s.d.
for internuclear distances . Corrections to proposed
approximations are evaluated. Separation constants and the oscillator strength
for the transition 1s\si_{g} \rar 2p\si_{u} are calculated and compared with
existing data.Comment: 16 pages, 4 figures, 6 tables, typos are corrected and small
additions are inserted, to be published at JPB (fast track comm
On Prospects for Exploration of Supersymmetry in Double Beta Decay Experiments
We analyze constraints on the parameters of the R-parity violating
supersymmetry which can be extracted from non-observation of the neutrinoless
nuclear double beta decay () at a given half-life lower bound.
Our analysis covers a large class of phenomenologically viable R-parity
violating SUSY models. We introduce special characteristics: the SUSY
sensitivity of a decaying isotope and the SUSY reach of a
experiment. The former provides a physical criterion for a
selection of the most promising isotopes for SUSY searches and the latter gives
a measure of success for a experiment in exploring the
R-parity violating SUSY parameter space. On this basis we discuss prospects for
exploration of supersymmetry in various experiments.Comment: 11 pages, 5 Postscript figures. Modified and updated version is
printed also in Proc. of NANP97 (JINR, Dubna, July 7--11, 1997): Phys. Atom
Nucl, 1998, 61, vol. 6, p.1092--109
Renormalization group in the infinite-dimensional turbulence: third-order results
The field theoretic renormalization group is applied to the stochastic
Navier-Stokes equation with the stirring force correlator of the form
k^(4-d-2\epsilon) in the d-dimensional space, in connection with the problem of
construction of the 1/d expansion for the fully developed fluid turbulence
beyond the scope of the standard epsilon expansion. It is shown that in the
large-d limit the number of the Feynman diagrams for the Green function (linear
response function) decreases drastically, and the technique of their analytical
calculation is developed. The main ingredients of the renormalization group
approach -- the renormalization constant, beta function and the ultraviolet
correction exponent omega, are calculated to order epsilon^3 (three-loop
approximation). The two-point velocity-velocity correlation function, the
Kolmogorov constant C_K in the spectrum of turbulent energy and the
inertial-range skewness factor S are calculated in the large-d limit to third
order of the epsilon expansion. Surprisingly enough, our results for C_K are in
a reasonable agreement with the existing experimental estimates.Comment: 30 pages with EPS figure
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