112 research outputs found
The Relativistic Linear Singular Oscillator
Exactly-solvable model of the linear singular oscillator in the relativistic
configurational space is considered. We have found wavefunctions and energy
spectrum for the model under study. It is shown that they have correct
non-relativistic limits.Comment: 14 pages, 12 figures in eps format, IOP style LaTeX file (revised
taking into account referees suggestions
Measurement of the cross section with the CMD-3 detector at the VEPP-2000 collider
The process has been studied in the
center-of-mass energy range from 1500 to 2000\,MeV using a data sample of 23
pb collected with the CMD-3 detector at the VEPP-2000 collider.
Using about 24000 selected events, the cross
section has been measured with a systematic uncertainty decreasing from 11.7\%
at 1500-1600\,MeV to 6.1\% above 1800\,MeV. A preliminary study of
production dynamics has been performed
Study of the process in the c.m. energy range from threshold to 2 GeV with the CMD-3 detector
Using a data sample of 6.8 pb collected with the CMD-3 detector at the
VEPP-2000 collider we select about 2700 events of the process and measure its cross section at 12 energy ponts with about
6\% systematic uncertainty. From the angular distribution of produced nucleons
we obtain the ratio
Electroproduction, photoproduction, and inverse electroproduction of pions in the first resonance region
Methods are set forth for determining the hadron electromagnetic structure in
the sub--threshold timelike region of the virtual-photon ``mass'' and
for investigating the nucleon weak structure in the spacelike region from
experimental data on the process at low energies. These
methods are formulated using the unified description of photoproduction,
electroproduction, and inverse electroproduction of pions in the first
resonance region in the framework of the dispersion-relation model and on the
basis of the model-independent properties of inverse electroproduction.
Applications of these methods are also shown.Comment: The revised published version; Revtex4, 18 pages, 6 figure
Density Matrix Kinetic Equation Describing a Passage of Fast Atomic Systems Through Matter
The quantum-mechanical consideration of a passage of fast dimesoatoms through
matter is given. A set of quantum-kinetic equations for the density matrix
elements describing their internal state evolution is derived. It is shown that
probabilistic description of internal dynamics of hydrogen-like atoms is
impossible even at sufficiently low energies because of the ``accidental''
degeneracy of their energy levels.Comment: 12 pages, LATEX, submitted to J. Phys.
Measurement of the cross section from threshold to 1.2 GeV with the CMD-3 detector
The cross section of the process has been measured in
the center of mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at
the electron-positron collider VEPP-2000. The measurement is based on a full
dataset collected below 1 GeV during three data taking seasons, corresponding
to an integrated luminosity of about 62 pb. In the dominant
-resonance region, a systematic uncertainty of 0.7% has been reached. At
energies around -resonance the production cross section was
measured for the first time with high energy resolution. The forward-backward
charge asymmetry in the production has also been measured. It
shows the strong deviation from the theoretical prediction based on
conventional sQED framework and is in good agreement with GVDM and
dispersive-based predictions. The impact of presented results on the evaluation
of the hadronic contribution to the anomalous magnetic moment of muon is
discussed.Comment: 52 pages, 36 figures; cosmetic changes of the text, fix fig.2 , fix
comment on used selection cuts in the attached radiative correction tabl
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