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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

The phi-meson and Chiral-mass-meson production in heavy-ion collisions as potential probes of quark-gluon-plasma and Chiral symmetry transitions

Possibilities of observing abundances of phi mesons and narrow hadronic pairs, as results of QGP and Chiral transitions, are considered for nucleus-nucleus interactions. Kinematical requirements in forming close pairs are satisfied in K+K decays of S(975) and delta (980) mesons with small phi, and phi (91020) mesons with large PT, and in pi-pi decays of familiar resonance mesons only in a partially restored chiral symmetry. Gluon-gluon dominance in QGP can enhance phi meson production. High hadronization rates of primordial resonance mesons which form narrow hadronic pairs are not implausible. Past cosmic ray evidences of anomalous phi production and narrow pair abundances are considered.

Takahashi, Y.↗
NASA NTRS1969

Validity of approximations used in mesonic atom calculations.

The Deser-Goldberger-Baumann-Thirring (DGBT) formula [a = 1/4B(ΔE 1S /|E 1S |)] and other various approximations commonly used to extract meson-nucleus scattering lengths from energy-level measurements on mesonic atoms are studied by means of a model calculation and are shown to be inadequate for most of the π − -mesonic atoms commonly considered. A simple empirical formula is obtained in place of the DGBT formula for the π − -mesonic atoms of the light nuclei. The DGBT formula is also examined for the case of the K − −He 4 atom and is found to be a good approximation.

Ryoichi Seki↗
NASA NTRS1985

Connection between variations of the atmosphere temperature profile and variations of the meson component intensity

The influence of temperature effects on intensity variations of the cosmic ray meson component were studied. The connection between the temperature variation delta T and the intensity variation delta I was established by using the temperature coefficient density technique. To realize how many devices are needed on the Earth for predicting the temperature variation of the atmosphere profile with a reasonable accuracy, IO isobaric levels and IO were calculated. The set of initial elements of the cosmic ray mesons are varied and it is shown that the matrix of the coefficients B sub ij is rather sensitive to their choice. It is found that if for the calculations of the atmospheric temperature variations the model is used, the number of meson components, essentially exceeding 3, should be considered.

Blokh, Y. L.↗
NASA NTRS1988

Accuracy of analytic energy level formulas applied to hadronic spectroscopy of heavy mesons

Linear and harmonic potential models are used in the nonrelativistic Schroedinger equation to obtain article mass spectra for mesons as bound states of quarks. The main emphasis is on the linear potential where exact solutions of the S-state eigenvalues and eigenfunctions and the asymptotic solution for the higher order partial wave are obtained. A study of the accuracy of two analytical energy level formulas as applied to heavy mesons is also included. Cornwall's formula is found to be particularly accurate and useful as a predictor of heavy quarkonium states. Exact solution for all partial waves of eigenvalues and eigenfunctions for a harmonic potential is also obtained and compared with the calculated discrete spectra of the linear potential. Detailed derivations of the eigenvalues and eigenfunctions of the linear and harmonic potentials are presented in appendixes.

Badavi, Forooz F.↗
NASA NTRS2008

Eta Meson Production in Proton-Proton and Nuclear Collisions

Total cross sections for eta meson production in proton - proton collisions are calculated. The eta meson is mainly produced via decay of the excited nucleon resonance at 1535 MeV. A scalar quantum field theory is used to calculate cross sections, which also include resonance decay. Comparison between theory and experiment is problematic near threshold when resonance decay is not included. When the decay is included, the comparison between theory and experiment is much better.

Norbury, John W.↗