25 research outputs found
Spectra of Quarkonia at Finite Temperature
Finite-temperature spectra of heavy quarkonia are calculated by combining
potential model and thermofield dynamics formalisms. The mass spectra of the
heavy quarkonia with various quark contents are calculated. It is found that
binding mass of the quarkonium decreases as temperature increases.Comment: 12 pages, 1 figure. To appear Mod.Phys.Lett.
Morphological Characteristics of Tumors of the Outer Ear
The article is devoted to the morphological picture of tumors of the outer ear. It was found that benign tumors predominate in the structure of tumors of the outer ear, which are most often found at the age of 30 years and are localized in the cartilaginous part of the external auditory canal and external ear. The main part consisted of keloids, glomus angiomas and lipomas. An important role in the diagnosis of tumors at the present stage is played by morphological methods, in particular, histological examination. It is noted that their timely use will contribute to effective prevention of benign tumors of the external ear
Electron loss of fast heavy projectiles in collision with neutral targets
The multiple electron loss of heavy projectiles in fast ion-atom collisions
has been studied in the framework of the sudden perturbation approximation.
Especially, a model is developed to calculate the cross sections for the loss
of any number of electrons from the projectile ion, including the ionization of
a single electron and up to the complete stripping of the projectile. For a
given collision system, that is specified by the (type and charge state of the)
projectile and target as well as the collision energy, in fact, the
experimental cross sections for just three final states of the projectile are
required by this model in order to predict the loss of any number, , of
electrons for the same collision system, or for any similar system that differs
only in the energy or the initial charge state of the projectile ion. The model
is simple and can be utilized for both, the projectile and target ionization,
and without that large computer resources are requested. Detailed computation
have been carried out for the multiple electron loss of Xe and
U projectiles in collision with neutral Ar and Ne gas
targets
Inelastic Processes in the Collision of Relativistic Highly Charged Ions with Atoms
A general expression for the cross sections of inelastic collisions of fast
(including relativistic) multicharged ions with atoms which is based on the
genelazition of the eikonal approximation is derived. This expression is
applicable for wide range of collision energy and has the standard
nonrelativistic limit and in the ultrarelativistic limit coincides with the
Baltz's exact solution ~\cite{art13} of the Dirac equation. As an application
of the obtained result the following processes are calculated: the excitation
and ionization cross sections of hydrogenlike atom; the single and double
excitation and ionization of heliumlike atom; the multiply ionization of neon
and argon atoms; the probability and cross section of K-vacancy production in
the relativistic collision. The simple analytic formulae
for the cross sections of inelastic collisions and the recurrence relations
between the ionization cross sections of different multiplicities are also
obtained. Comparison of our results with the experimental data and the results
of other calculations are given.Comment: 25 pages, latex, 7 figures avialable upon request,submitted to PR