Characteristics of alpha projectile fragments emission in interaction of nuclei with emulsion

The properties of the relativistic alpha fragments produced in interactions of 84^Kr at around 1 A GeV in nuclear emulsion are investigated. The experimental results are compared with the similar results obtained from various projectiles with emulsion interactions at different energies. The total, partial nuclear cross-sections and production rates of alpha fragmentation channels in relativistic nucleus-nucleus collisions and their dependence on the mass number and initial energy of the incident projectile nucleus are investigated. The yields of multiple alpha fragments emitted from the interactions of projectile nuclei with the nuclei of light, medium and heavy target groups of emulsion-detector are discussed and they indicate that the projectile-breakup mechanism seems to be free from the target mass number. It is found that the multiplicity distributions of alpha fragments are well described by the Koba-Nielsen-Olesen (KNO) scaling presentation. The mean multiplicities of the freshly produced newly created charged secondary particles, normally known as shower and secondary particles associated with target in the events where the emission of alpha fragments were accompanied by heavy projectile fragments having Z value larger than 4 seem to be constant as the alpha fragments multiplicity increases, and exhibit a behavior independent of the alpha fragments multiplicity.Comment: 33 pages, 8 figures and 3 tables (in press

Supersymmetric Gauge Theories with an Affine Quantum Moduli Space

All supersymmetric gauge theories based on simple groups which have an affine quantum moduli space, i.e. one generated by gauge invariants with no relations, W=0, and anomaly matching at the origin, are classified. It is shown that the only theories with no gauge invariants (and moduli space equal to a single point) are the two known examples, SU(5) with 5-bar + 10 and SO(10) with a spinor. The index of the matter representation must be at least as big as the index of the adjoint in theories which have a non-trivial relation among the gauge invariants.Comment: Incorrect proof that theories with constraints must have mu >= mu(adj) replaced by a correct one (6 pages, uses revtex, amssymb, array

Environmental pollutants in blood donors: The multicentre Norwegian donor study

Objectives - The aim of this study was to measure blood concentrations of environmental pollutants in Norwegian donors and evaluate the risk of pollutant exposure through blood transfusions. Background - Transfused blood may be a potential source of exposure to heavy metals and organic pollutants and presents a risk to vulnerable patient groups such as premature infants. Methods/Materials - Donors were randomly recruited from three Norwegian blood banks: in Bergen, Tromsø and Kirkenes. Selected heavy metals were measured in whole blood using inductively coupled plasma mass spectrometry (ICP‐MS), and perfluoroalkyl substances (PFAS) were measured in serum by ultrahigh‐pressure liquid chromatography coupled with a triple‐quadrupole mass spectrometer (UHPLC‐MS/MS). Results - Almost 18% of blood donors had lead concentrations over the limit suggested for transfusions in premature infants (0.09 μmol/L). About 11% of all donors had mercury concentrations over the suggested limit of 23.7 nmol/L. Cadmium was higher than the limit, 16 nmol/L, in 4% of donors. Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) concentrations were over the suggested limit of 0.91 ng/mL in 68% and 100% of the donors, respectively. PFAS concentrations and heavy metal concentrations increased with donor's age. Conclusion - A considerable percentage of donors had lead, PFOS and PFOA concentrations over the suggested limits. In addition, at each study site, there were donors with high mercury and cadmium concentrations. Selecting young donors for transfusions or measurements of pollutants in donor blood may be a feasible approach to avoid exposure through blood transfusions to vulnerable groups of patients such as premature infants

Enabling comparison of UrQMD with Geant4 hadronic models

Geant4 has an abundant set of physics models that handle the diverse interaction of particles with matter across a wide energy range. However, there are also many well established reaction codes currently used in the same fields where Geant4 is applied. One such code is the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model. In order to take advantage of the UrQMD code, we create a tool to enable comparisons among UrQMD and Geant4 hadronic models. This tool allows a user to process the output file of UrQMD through Geant4 toolkit, while at the same time, can choose among different Geant4 hadronic model generators. As an example, the UrQMD model is compared with the HARP-CDP experimental data and with the Binary and FRITIOF generators, in the framework of Geant4. It is shown that the UrQMD model can better reproduce charged pion production for p+Cu and Pb interactions at 3, 8 and 15 GeV/c, and is a good candidate for Geant4 hadronic models.Comment: 17 pages, 5 Figure

Momentum Correlations of Charmed Pairs Produced in π−−Cu\pi^{-}-Cu Interactions at 230 GeV/c

We study the production characteristics of 557 pairs of charmed hadrons produced in $\pi^{-}-Cu$\ interactions at 230~GeV/c using a momentum estimator for charmed hadrons with missing decay products. We find, the mean value of the transverse momentum squared of the charmed pairs is $=(1.98\pm 0.11\pm 0.09)\;$ GeV$^2$/c$^2$, the mean rapidity difference is $=0.54\pm 0.02\pm 0.24$, and the mean effective mass is $=(4.45\pm 0.03\pm 0.13)\;$ GeV/c$^2$. Comparing these results with the next-to-leading order QCD predictions we find an agreement for the \yd\ and \mef, whilst the measured mean value of \pts\ is significantly larger than the predicted value.Comment: 10 pages, LaTeX, 4 (pages) postscript figure

Dissociation of relativistic 10^{10}C nuclei in nuclear track emulsion

Dissociation of 1.2 A GeV $^{10}$C nuclei in nuclear track emulsionis is studied. It is shown that most precise angular measurements provided by this technique play a crucial role in the restoration of the excitation spectrum of the 2$\alpha$+2p system. Strong contribution of the cascade process $^{10}$C$\rightarrow ^9$B$\rightarrow ^8$Be identified.Comment: 5 pages, 3 figures, conference: The 21st European Conference on Few-Body Problems in Physics, Salamanca, Spain, 29th August - 3rd September, 201

Применение белого люпина в качестве компонента комбикормов для ценных видов рыб

Применение белого люпина как компонента для производства комбикормов применяемых при выращивании ценных видов рыб позволяет увеличить эффективность усвояемости белка, повысит плавучесть и водостойкость гранул комбикорма применяемого в индустриальной аквакультуре

ON THE INTRINSIC CHARM COMPONENT OF THE NUCLEON

Using a $\overline D$ meson cloud model we calculate the squared charm radius of the nucleon . The ratio between this squared radius and the ordinary baryon squared radius is identified with the probability of ``seeing'' the intrinsic charm component of the nucleon. Our estimate is compatible with those used to successfully describe the charm production phenomenology.Comment: 9 pages, 2 figures not included, avaiable from the author

Alignment in Gamma-Hadron Families of Cosmic Rays

Alignment of main fluxes of energy in a target plane is found in families of cosmic ray particles detected in deep lead X-ray chambers. The fraction of events with alignment is unexpectedly large for families with high energy and large number of hadrons. This can be considered as evidence for the existence of coplanar scattering of secondary particles in interaction of particles with superhigh energy, $E_0 > 10^{16}$ eV. Data analysis suggests that production of most aligned groups occurs low above the chamber and is characterized by a coplanar scattering and quasiscaling spectrum of secondaries in the fragmentation region. The most elaborated hypothesis for explanation of alignment is related to the quark-gluon string rupture. However, the problem of theoretical interpretation of our results still remains open.Comment: 15 pages, 2 tables, 6 figures (not included), Stanford University preprint SU-ITP-94-2