385 research outputs found
A study of gamma-families generated in nucleon-nucleus (NA) and pion-nucleus (pi A) interactions
The separation of the gamma families generated in nucleon-nuclear and pion-nuclear (PI-A) interactions is realized from the analysis of simulated gamma families. Some characteristics of NA and PI families and the influence of the process of inelastic charge-exchange of charged pions neutral ones type of PI + or - A yields are studied
A Conserved Vector Current test using low energy beta-beams
We discuss the possibility of testing the weak currents and, in particular,
the weak magnetism term through the measurement of the electron anti-neutrinos
capture by protons at a low energy beta-beam facility. We analyze the
sensitivity using both the total number of events and the angular distribution
of the positrons emitted in a water Cerenkov detector. We show that the weak
magnetism form factor might be determined with better than several percent
accuracy using the angular distribution. This offers a new way of testing the
Conserved Vector Current hypothesis.Comment: 8 pages, 5 figure
A comparative analysis of gamma and hadron families at the superhigh energies recorded in experiment Pamir
A comparative analysis of hadron and gamma families which have undergone the decascading procedure is made. Results are compared with different models of interactions. In hadron families with energies Summary E sub H sup gamma 20 TeV as well as in gamma families with energies Summary E sub gamma 70 TeV, increasing azimuthal anisotropy is observed
Light Baryon Resonances: Restrictions and Perspectives
The problem of nucleon resonances N' with masses below the Delta is
considered. We derive bounds for the properties of such states. Some of these
are new, while others improve upon existing limits. We discuss the nature of N'
states, and their unitary partners, assuming their existence can be verified.Comment: 11 pages, 11 figur
Low energy neutrino scattering measurements at future Spallation Source facilities
In the future several Spallation Source facilities will be available
worldwide. Spallation Sources produce large amount of neutrinos from
decay-at-rest muons and thus can be well adapted to accommodate
state-of-the-art neutrino experiments. In this paper low energy neutrino
scattering experiments that can be performed at such facilities are reviewed.
Estimation of expected event rates are given for several nuclei, electrons and
protons at a detector located close to the source. A neutrino program at
Spallation Sources comprises neutrino-nucleus cross section measurements
relevant for neutrino and core-collapse supernova physics, electroweak tests
and lepton-flavor violation searches.Comment: 12 pages, 4 figures, 5 table
Schistosomatidae from the trematode fauna of aquatic and semi-aquatic birds in Uzbekistan
The article discusses the infection of wetland birds in Uzbekistan with the trematodes Schistosomatidae Stiles et Hassall, 1898. The research covered 282 individuals from the main groups of birds represented by the orders Pelecaniformes, Ciconiformes, Anseriformes, Gruiformes, Podicipediformes and Charadriiformes. The Schistosomatidae fauna of Uzbekistan includes 13 species: Bilharziella polonica (Kowalewsky, 1895), Trichobilharzia ocellata (La Valette, 1854), T. filiformis (Szidat, 1938), T. kowalewskii (Ejsmont, 1929), T. tatianae (Spasskaja, 1953), Macrobilharzia macrobilharzia Trawassos, 1923, Ornithobilharzia canaliculata (Rudolphi, 1819), O. baeri Fain, 1955, Dendritobilharzia pulverulenta (Braun, 1901), D. loossi Skrjabin, 1924, D. anatinarum Cheatum, 1941, Gigantobilharzia acotylea Odhner, 1910 and Gigantobilharziella monocotylea (Szidat, 1930). Predominant are representatives of the genera Trichobilharzia and Dendritobilharzia. The species composition of Schistosomatidae is most diverse in birds from the lower reaches of the Amu Darya, where a high rate of infection with larvae of some of these trematodes was also recorded in aquatic molluscs. 11 species of molluscs were registered in the studied regions: Galba truncatula (Muller, 1774), Stagnicola corvus (Gmelin, 1791), Radix auricularia (Linnaeus, 1758), Lymnaea stagnalis (Linnaeus, 1758), Physa fontinalis (Linnaeus, 1758), Physella acuta (Draparnaud, 1805), Planorbis planorbis (Linnaeus, 1758), P. tangitarensis Germain, 1918, Anisus spirorbis (Linnaeus, 1758), Gyraulus albus (Muller, 1774), Melanoides kainarensis Starobogatov et Izzatullaev, 1980, from the families Lymnaeidae (4 species), Planorbidae (4 species), Physidae (2 species) and Thiaridae (1 species). They are identified as intermediate hosts of Schistosomatidae and were infected with 7 species of flukes. The total rate of infection with larval stages of Schistosomatidae in molluscs was about 2.0%. The highest infection rate was observed in Melanoides kainarensis – 5.3%. Morpho-biological indicators for mature forms of B. polonica from different bird species (Anas platyrhynchos and Oxyura leucocephala) were confirmed by molecular genetic studies. The study identified foci of birds’ infection with Schistosomatidae and the occurrence of human cercarial dermatitis
Unbroken supersymmetry in the Aharonov-Casher effect
We consider the problem of the bound states of a spin 1/2 chargless particle
in a given Aharonov-Casher configuration. To this end we recast the description
of the system in a supersymmetric form. Then the basic physical requirements
for unbroken supersymmetry are established. We comment on the possibility of
neutron confinement in this system
Low x particle spectra in the Modified Leading Logarithm Approximation
We show that the higher moments of the evolution obtained from the Modified
Leading Logarithm Approximation may be regarded as spurious higher order terms
in perturbation theory, and that neglecting them leads to a good description of
the data around and above the peak in . Furthermore, we use this
study of the moments to show that at high energy the Limiting Spectrum with
Local Parton-Hadron Duality may also be derived from the Modified Leading
Logarithm Approximation without any non-perturbative assumptions.Comment: Submitted to Eur. Phys. J.,
Towards a common origin of the elliptic flow, ridge and alignment
It is claimed that elliptic flow, ridge and alignment are effects of
azimuthal asymmetry, which have a common origin evolving with primary energy
and stemming from the general structure of field-theoretical matrix elements.
It interrelates a new ridge-phenomenon, recently found at the LHC and RHIC,
with known coplanarity feature observed in collider jet physics as well as in
cosmic ray studies.Comment: 4 pages, few typos fixed, reference added, version published in JETP
Letter
Monte Carlo simulation for jet fragmentation in SUSY-QCD
We present results from a new Monte Carlo simulation for jet fragmentation in
QCD and SUSY QCD for large primary energies up to GeV. In
the case of SUSY QCD the simulation takes into account not only gluons and
quarks as cascading particles, but also their supersymmetric partners. A new
model-independent hadronization scheme is developed, in which the hadronization
functions are found from LEP data. An interesting feature of SUSY QCD is the
prediction of a sizeable flux of the lightest supersymmetric particles (LSPs),
if R-parity is conserved. About 10% of the jet energy is transferred to LSPs
which, owing to their harder spectra, constitute an important part of the
spectra for large . Spectra of protons and of secondary particles,
photons and neutrinos, are also calculated. These results have implications for
the decay of superheavy particles with masses up to the GUT scale, which have
been suggested as a source of ultrahigh energy cosmic rays.Comment: latex, 25 pages with 17 eps figure
- …