367 research outputs found
Ratio of productions of pi+pi-atoms to free pi+pi- pairs with account of the strong interaction in final states
The ratio of productions of pi+pi- atoms to free pi+pi- pairs is calculated
with account of the strong interaction in final states. It is shown that this
ratio is expressed via a squared ratio of the well-known Coulomb wave functions
and thus can be calculated with a high accuracy.Comment: 3 page
Contribution of -terms to the total interaction cross sections of relativistic elementary atoms with atoms of matter
It is shown that the corrections of order to the total cross
sections for interaction of elementary hydrogen-like atoms with target atoms,
reported in the previously published paper [S.Mrowczynski, Phys.Rev. D36, 1520
(1987)], do not include some terms of the same order of magnitude. That results
in a significant contribution of these corrections in particular cases. The
full -corrections have been derived and it is shown that they are
really small and could be omitted for most practical applications.Comment: 5 page
Sum Rules for Total Interaction Cross Sections of Relativistic Elementary Atoms with Atoms of Matter Up to Terms of Order
It is shown that -term of sum rules for the total cross sections of
interaction of elementary atoms with matter ones, obtained in ref.[Denisenko K.
and Mrowczynski S., Phys. Rev. D36 (1987) 1529] is wrong. New sum rules valid
up to terms of order are derived.Comment: 3 page
Dynamics of the Pionium with the Density Matrix Formalism
The evolution of pionium, the hydrogen-like atom, while passing
through matter is solved within the density matrix formalism in the first Born
approximation. We compare the influence on the pionium break-up probability
between the standard probabilistic calculations and the more precise picture of
the density matrix formalism accounting for interference effects. We focus our
general result in the particular conditions of the DIRAC experiment at CERN.Comment: 14 pages, 2 figures, submitted to J. Phys. B: At. Mol. Phy
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.
The multilevel trigger system of the DIRAC experiment
The multilevel trigger system of the DIRAC experiment at CERN is presented.
It includes a fast first level trigger as well as various trigger processors to
select events with a pair of pions having a low relative momentum typical of
the physical process under study. One of these processors employs the drift
chamber data, another one is based on a neural network algorithm and the others
use various hit-map detector correlations. Two versions of the trigger system
used at different stages of the experiment are described. The complete system
reduces the event rate by a factor of 1000, with efficiency 95% of
detecting the events in the relative momentum range of interest.Comment: 21 pages, 11 figure
Chromosome Abnormalities and Hematopoietic Stem Cell Transplantation in Acute Leukemias
The chapter considers specific treatment options, including allogeneic hematopoietic stem cell transplantation (allo‐HSCT) in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL), in patients with some prognostically proven cytogenetic variants as monosomal ones, complex and hyperdiploid karyotypes, like chromosomal translocations t(v;11)(v;q23), t(3;3)/inv(3); t(8;21), t(9;22), etc. Important prognostic role of additional chromosome abnormalities was shown for the patients with t(8;21) and t(9;22). Hence, it is evident that allo‐HSCT in patients with poor risk cytogenetic variant must be performed as early as possible, i.e., during first complete remission
Theoretical Predictions for Pionium Searches
Characteristic properties of pionium and associated low energy
s--wave cross sections ,
and are
investigated with a coupled channels potential model. Some experimental results
and conclusions are to be reconsidered.Comment: 10 Pages REVTeX using epsfig.sty. Submitted to PR
- …