Nomenclatura Unesco > (22) Física > (2208) Nucleónica

Diffractive Contribution to the Elasticity and the Nucleonic Flux in the Atmosphere

J. Bell,R. J. M. Covolan,A. L. Godoi,J. Montanha,Gleb Wataghin

We calculate the average elasticity considering non-diffractive and single diffractive interactions and perform an analysis of the cosmic-ray flux by means of an analytical solution for the nucleonic diffusion equation. We show that the diffractive contribution is important for the adequate description of the nucleonic and hadronic fluxes in the atmosphere. It is well known that the evolution of the nucleonic cosmic ray component is controlled by two physical quantities related to high energy...

Consistent Effective Description Of Nucleonic Resonances In An Unitary Relativistic Field-Theoret...

F. Kleefeld

High energy strong interaction physics is successfully described by the local renormalizable gauge theory called Quantum--Chromo--Dynamics (QCD) with quarks and gluons as "elementary" degrees of freedom, while intermediate energy strong interaction physics shows up to be determined by a non--local, non--renormalizable effective field theory (EFT) of "effective" degrees of freedom like mesons, ground state baryons and resonances. The connection between high and intermediate physics is establis...

Consistent Effective Description Of Nucleonic Resonances In An Unitary Relativistic Field--Theore...

F. Kleefeld

Nucleonic coal detector with independent, hydropneumatic suspension

Jones, E. W.; Handy, K.

The design of a nucleonic, coal interface detector which measures the depth of coal on the roof and floor of a coal mine is presented. The nucleonic source and the nucleonic detector are on independent hydropneumatic suspensions to reduce the measurement errors due to air gap.

Optimal configuration for a zero-g nucleonic fuel gage.

Pfeifer, R. J.

Optimal configuration for zero-g nucleonic fuel gage

Nucleonic measurements of cryogenic densities and qualities.

Cho, B. Y.; Scheiwe, J. P.

Liquid and slush hydrogen density data measured by fast response nucleonic densitometer, reviewing liquid-vapor quality data obtained from cryogenic meter

Nucleonic lunar ranging and tracking system Final report

Nucleonic lunar ranging and tracking system for altitude measurement in lunar landing vehicles

Construction of gauge invariant effective nucleonic theories: functional approach

Naus, H. W. L.

Starting from relativistic quantum field theories, describing interacting nucleons and pions coupled to the dynamical electromagnetic field, the pion degrees of freedom are eliminated by means of functional integration. Apart from taking into account some operators perturbatively in $e$, e.g. the vacuum polarization, this procedure is exact, giving effective theories for nucleons and photons. The subsequent nonrelativistic reduction yields the corresponding nonrelativistic quantum field theor...

Nucleonic resonance effects in the $\phi$ meson photoproduction

Zhao, Q.; Didelez, J. -P.; Guidal, M.; Saghai, B.

The process $\gamma p \to \phi p$ close to threshold is investigated focusing on the role played by the {\it s}- and {\it u}-channel nucleonic resonances. For this purpose, a recent quark model approach, based on the $SU(6)\otimes O(3)$ symmetry with an effective Lagrangian, is extended to the $\phi$ meson photoproduction. Another non-diffractive process, the {\it t}-channel $\pi^0$ exchange, is also included. The diffractive contribution is produced by the {\it t}-channel Pomeron exchange. C...

Pairing properties of nucleonic matter employing dressed nucleons

Müther, H.; Dickhoff, W. H.

A survey of pairing properties of nucleonic matter is presented that includes the off-shell propagation associated with short-range and tensor correlations. For this purpose, the gap equation has been solved in its most general form employing the complete energy and momentum dependence of the normal self-energy contributions. The latter correlations include the self-consistent calculation of the nucleon self-energy that is generated by the summation of ladder diagrams. This treatment preserve...

Diffractive Contribution to the Elasticity and the Nucleonic Flux in the Atmosphere

Bellandi, J.; Covolan, R. J. M.; Godoi, A. L.; Montanha, J.

Nucleonic gamma-ray production in Pulsar Wind Nebulae

Horns, D.; Aharonian, F.; Hoffmann, A. I. D.; Santangelo, A.

Observations of the inner radian of the Galactic disk at very high energy (VHE) gamma-rays have revealed at least 16 new sources. Besides shell type super-nova remnants, pulsar wind nebulae (PWN) appear to be a dominant source population in the catalogue of VHE gamma-ray sources. Except for the Crab nebula, the newly discovered PWN are resolved at VHE gamma-rays to be spatially extended (5-20 pc). Currently, at least 3 middle aged ($t>10$ kyrs) PWN (Vela X, G18.0-0.7, and G313.3+0.6 in the ``...

Complete Set of Splitting Functions Relevant in the Evolution of Nucleonic Helicity Distributions

Kundu, Rajen

In this work, we show how the complete set of splitting functions relevant for the evolution of various distribution functions describing nucleonic helicity structure can be obtained in the light front Hamiltonian perturbation theory using completely fixed light front gauge, $A^+=0$.

Has Nucleonic Matter at the Critical Point Been Produced in Recent Multifragmentation Experiments?

For nuclei in five different mass regions the critical temperatures, at which the surface tension vanishes, are derived from information on the liquid branch of the coexistence curve. These critical temperatures increase with increasing mass and, for higher masses are well above recently reported critical temperatures obtained from Fisher Droplet model and percolation model analyses. However, for the lowest mass region nuclei, with 30

Nucleonic resonance excitations and "missing resonances" in the $\omega$ meson photoproduction

Zhao, Q.

In this work, an improved quark model approach to the $\omega$ meson photoproduction with an effective Lagrangian is reported. The {\it t}-channel {\it natural} parity exchange is consistently taken into account through the Pomeron exchange, while the {\it unnatural} parity exchange is described by the $\pi^0$ exchange. It shows that with very limited number of parameters, all the available experimental data in the low energy regime can be consistently accounted for in this framework. Effects...

Is it Possible to Describe Short-range NN Correlations in Nuclei on the Basis of Nucleonic Degr...

Ryzhikh, G. G.

Assuming that NN interaction is modified inside a nucleus by a specific way, phenomenological effective broad core (BC) NN potential is constructed. It is shown that increase in the width of repulsive core lets us describe the Coulomb form factors of few-body nuclei on the basis of nucleonic degrees of freedom only.

Solar-cycle dependence of galactic cosmic ray flux. II - The correlation between the nucleonic fl...

Parker, G. D.; Chasson, R. L.; Hansen, R. T.; Hansen, S. F.

To investigate the relationship between solar activity and cosmic-ray modulation, time series of the nucleonic flux and of solar plages, sunspots, centimeter radio noise, and the brightness of the white-light corona at 1.1 and 1.5 solar radii from the center of sun are cross-correlated. Data pertain to the years 1964-1967 during the ascending phase of the current solar cycle. The amplitudes and phases of correlation functions for filtered and unfiltered indices are discussed. The existence of...

Improved nucleonic coal-thickness monitor

Crouch, C. E.; Rose, S. D.; Jones, E. W.

Design for coal-thickness-sensing instrument features independent hydropneumatic suspension of radiation source and detector. Monitor uses source and detector which are independently mounted, to follow contour of coal surface more closely and to eliminate errors caused by variations in airgap along radiation path. Device may help to bring fully-automated coal mining closer to reality.

Nucleonic thickness gauges -- a SAPPHO pair

Rothwell, R.

Equation of state of nucleonic matter

Cassing, W.

The nuclear equation of state (EoS) is investigated by flow phenomena in relativistic heavy-ion collisions, both in transverse and radial direction, in comparison to experimental data from 150 A MeV to 11 A GeV. To this aim the collective dynamics of the nucleus-nucleus collision is described within a transport model of the coupled channel RBUU type. There are two factors which dominantly determine the baryon flow at these energies: the momentum dependence of the scalar ($U_S$) and vector pot...