152 research outputs found
On the numerical closeness of the effective phenomenological electroweak mixing angle and the \MS parameter
It happens that and are equal with 0.1% accuracy, though
they are split by radiative corrections and a natural estimate for their
difference is 1%. This degeneracy occurs only for value close to
170\GeV, so no deep physical reason can be attributed to it. However, another
puzzle of the Standard Model, the degeneracy of s_\Eff^2 and , is not
independent of the previous one since a good physical reason exists for
s_\Eff^2 and degeneracy. We present explicit formulas which relate
these three angles.Comment: 10 pages, latex, 3 figures included; published on MPLA. A few
numerical estimates are improved; journal-ref is adde
QCD Corrections to Electroweak Annihilation Decays of Superheavy Quarkonia
QCD corrections to all the allowed decays of superheavy groundstate quarkonia
into electroweak gauge and Higgs bosons are presented. For quick estimates,
approximations that reproduce the exact results within less than at worst two
percent are also given.Comment: 20 pages RevTeX, 9 figures. The complete paper, including figures, is
also available via anonymous ftp at (129.13.102.139) as
ftp://ttpux2.physik.uni-karlsruhe.de/ttp95-05/ttp95-05.ps, or via www at
http://ttpux2.physik.uni-karlsruhe.de/cgi-bin/preprints
Binary systems of neutral mesons in Quantum Field Theory
Quasi-degenerate binary systems of neutral mesons of the kaon type are
investigated in Quantum Field Theory (QFT). General constraints cast by
analyticity and discrete symmetries P, C, CP, TCP on the propagator (and on its
spectral function) are deduced. Its poles are the physical masses; this
unambiguously defines the propagating eigenstates. It is diagonalized and its
spectrum thoroughly investigated. The role of ``spurious'' states, of zero norm
at the poles, is emphasized, in particular for unitarity and for the
realization of TCP symmetry. The K_L-K_S mass splitting triggers a tiny
difference between their CP violating parameters \epsilon_L and \epsilon_S,
without any violation of TCP. A constant mass matrix like used in Quantum
Mechanics (QM) can only be introduced in a linear approximation to the inverse
propagator, which respects its analyticity and positivity properties; it is
however unable to faithfully describe all features of neutral mesons as we
determine them in QFT, nor to provide any sensible parameterization of eventual
effects of TCP violation. The suitable way to diagonalize the propagator makes
use of a bi-orthogonal basis; it is inequivalent to a bi-unitary transformation
(unless the propagator is normal, which cannot occur here). Problems linked
with the existence of different ``in'' and ``out'' eigenstates are smoothed
out. We study phenomenological consequences of the differences between the QFT
and QM treatments. The non-vanishing of semi-leptonic asymmetry \delta_S -
\delta_L does not signal, unlike usually claimed, TCP violation, while A_TCP
keeps vanishing when TCP is realized. We provide expressions invariant by the
rephasing of K0 and K0bar.Comment: 44 pages, 2 figures. Version to appear in Int. J. Mod. Phys.
Quarkonium production in SM Higgs decays
We investigate the SM Higgs decays into heavy quarkonia J/\psi and \Upsilon
in both color-singlet and color-octet mechanisms. It is found that in J/\psi
production the contribution through color-octet processes overwhelm that in
color-singlet processes all the intermediate region M_Z<M_{H^0}<2 M_w and the
fraction ratio is comparatively large, but in \Upsilon production the
contribution through color-octet mechanism is negligible.Comment: 9 pages, LaTex, 4 postscript figures. To appear in Journal of Physics
Macro- and microelements determination in children with rotavirus infection
The purpose of this study was to determine serum zinc, iron, magnesium, copper, potassium, calcium, and sodium levels in acute rotavirus infection and convalescence period in children.
Materials and methods. We examined 86 patients aged from 4 months to 5 years with clinical and laboratory signs of rotavirus infection. The I group – 43 children with RVI in acute period. The II group – 43 children with RVI in convalescence period. The control group included 14 healthy children at the same age. The content of macro- and microelements (zinc, iron, magnesium, copper, potassium, calcium and sodium) in blood serum was determined by atomic absorption spectrophotometry. Feces samples were used for Cito Test Rota (Pharmasco). Cito test was used for rotavirus antigen detection in feces. Statistical analysis was performed by Excel. Student’s t-test was used to evaluate differences between study groups.
Results. The acute period of the disease in children with rotavirus infection was characterized by a significant increase of copper in blood serum compared with the control group. At the same time, a significant decrease of iron, magnesium, zinc, potassium, calcium, sodium were determined in patients with rotavirus infection, compared with apparently healthy children. After standard treatment only the indicators of magnesium, potassium and sodium reached the same indices of control group children.
Conclusions. The detected changes in the mineral status of patients with rotavirus infection suggest the need for treatment correction. Correction of micro- and macroelements imbalances in patients with rotavirus infection possibly should be aimed at the metallo-drugs inclusion in complex treatment as well as medicines which improve absorption of the latter in the intestine
Conference of Soviet and American Jurists on the Law of the Sea and the Protection of the Marine Environment
Included in the papers for the Conference of Soviet and American Jurists on the Law of the Sea and the Protection of the Marine Environment:
Introduction by Milton Katz and Richard R. Baxter, p. 1
Freedom of Scientific Research in the World Ocean by A.F. Vysotsky, p. 7
The International Law of Scientific Research in the Oceans by Richard R. Baxter, p. 27
Responsibility and Liability for Harm to the Marine Environment by Robert E. Stein, p. 41
Liability for Marine Environment Pollution Damage in Contemporary International Sea Law by A. L. Makovsky, p. 59
Protection of the Marine Environment from Pollution by Richard A. Frank, p. 73
The Freedom of Navigation and the Problem of Pollution of the Marine Environment by V. A. Kiselev, p. 93
The Freedom of Navigation Under International Law by William E. Butler, p. 107
International Fisheries Management Without Global Agreement: United States Policies and Their Impact on the Soviet Union by H. Gary Knight, p. 119
Some Biological Background for International Legal Acts on Rational Utilization of the Living Resources of the World Ocean by P. A. Moiseev, p. 143
An International Regime for the Seabed Beyond National Jurisdiction by Thomas M. Franck, p. 151
Settlement of Disputes Under the Law of Ocean Use, with Particular Reference to Environmental Protection by John Lawrence Hargrove, p. 18
Solving the mu problem with a heavy Higgs boson
We discuss the generation of the mu-term in a class of supersymmetric models
characterized by a low energy effective superpotential containing a term lambda
S H_1 H_2 with a large coupling lambda~2. These models generically predict a
lightest Higgs boson well above the LEP limit of 114 GeV and have been shown to
be compatible with the unification of gauge couplings. Here we discuss a
specific example where the superpotential has no dimensionful parameters and we
point out the relation between the generated mu-term and the mass of the
lightest Higgs boson. We discuss the fine-tuning of the model and we find that
the generation of a phenomenologically viable mu-term fits very well with a
heavy lightest Higgs boson and a low degree of fine-tuning. We discuss
experimental constraints from collider direct searches, precision data, thermal
relic dark matter abundance, and WIMP searches finding that the most natural
region of the parameter space is still allowed by current experiments. We
analyse bounds on the masses of the superpartners coming from Naturalness
arguments and discuss the main signatures of the model for the LHC and future
WIMP searches.Comment: Extended discussion of the LHC phenomenology, as published on JHEP
plus an addendum on the existence of further extremal points of the
potential. 47 pages, 16 figure
Cosmological constraints on R-parity violation from neutrino decay
If the neutrino mass is non-zero, as hinted by several experiments, then
R-parity-violating supersymmetric Yukawa couplings can drive a heavy neutrino
decay into lighter states. The heavy neutrino may either decay radiatively into
a lighter neutrino, or it may decay into three light neutrinos through a
Z-mediated penguin. For a given mass of the decaying neutrino, we calculate its
lifetime for the various modes, each mode requiring certain pairs of
R-parity-violating couplings be non-zero. We then check whether the calculated
lifetimes fall in zones allowed or excluded by cosmological requirements. For
the latter case, we derive stringent new constraints on the corresponding
products of R-parity-violating couplings for given values of the decaying
neutrino mass.Comment: 13 pages, Latex, uses axodraw.sty; version to appear in Physical
Review
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