45 research outputs found
Invariant Connections with Torsion on Group Manifolds and Their Application in Kaluza-Klein Theories
Invariant connections with torsion on simple group manifolds are studied
and an explicit formula describing them is presented. This result is used for
the dimensional reduction in a theory of multidimensional gravity with
curvature squared terms on . We calculate the potential of
scalar fields, emerging from extra components of the metric and torsion, and
analyze the role of the torsion for the stability of spontaneous
compactification.Comment: 13 pages, LATEX, UB-ECM-PF 93/1
Plane torsion waves in quadratic gravitational theories
The definition of the Riemann-Cartan space of the plane wave type is given.
The condition under which the torsion plane waves exist is found. It is
expressed in the form of the restriction imposed on the coupling constants of
the 10-parametric quadratic gravitational Lagrangian. In the mathematical
appendix the formula for commutator of the variation operator and Hodge
operator is proved. This formula is applied for the variational procedure when
the gravitational field equations are obtained in terms of the exterior
differential forms.Comment: 3 May 1998. - 11
Search for the Cryptoexotic Member of the Baryon Antidecuplet 1/2+ in the Reactions pi- p --> pi- p and pi- p --> K L
The main goal of this proposal is the search for a narrow cryptoexotic
nucleon resonance by scanning of the pi- p system invariant mass in the region
(1610-1770) MeV with the detection of pi- p and K Lambda decays. The scan is
supposed to be done by the variation of the incident pi- momentum and its
measurement with the accuracy of up to +-0.1% (better than 1 MeV in terms of
the invariant mass in the whole energy range) with a set of proportional
chambers located in the first focus of the magnetooptical channel. High
sensitivity of the method to the resonance under search is shown. The secondary
particles scattered from a liquid hydrogen target are detected by sets of the
wire drift chambers equipped with modern electronics. The time scale of the
project is about 3 years. The budget estimate including manpower, the apparatus
and operation cost, is about 40 million rubles. The beam time required is (4-6)
two week runs on "high" (10 GeV/c) flattop of the ITEP proton synchrotron.Comment: 16 pages, 10 figures. v2: an acknowledge adde
Axial-Vector Torsion and the Teleparallel Kerr Spacetime
In the context of the teleparallel equivalent of general relativity, we
obtain the tetrad and the torsion fields of the stationary axisymmetric Kerr
spacetime. It is shown that, in the slow rotation and weak field
approximations, the axial-vector torsion plays the role of the gravitomagnetic
component of the gravitational field, and is thus the responsible for the
Lense-Thirring effect.Comment: 9 pages, no figures, to appear in Class. Quant. Gra
Backward asymmetry measurements in the elastic pion-proton scattering at resonance energies
The asymmetry parameter P was measured for the elastic pion-proton scattering
in the very backward angular region of theta_cm ~ 150-170^o at several pion
beam energies in the invariant mass range containing most of the pion-proton
resonances.
The general goal of the experimental program was to provide new data for
partial wave analyses in order to resolve their uncertainties in the baryon
resonance region to allow the unambiguous baryon spectrum reconstructions.
Until recently the parameter P was not measured in the examined domain that
might be explained by the extremely low cross section. At the same time the
predictions of various partial wave analyses are far from agreement in some
kinematic areas and specifically those areas were chosen for the measurements
where the disagreement is most pronouncing.
The experiment was performed at the ITEP U-10 proton synchrotron, Moscow, by
the ITEP-PNPI collaboration in the latest 5 years.Comment: 6 pages, 5 figures. to be submitted to the European Physical Journa