19 research outputs found
Ătude par diffusion des neutrons de la cinĂ©tique des moments magnĂ©tiques dans le fer au voisinage du point de Curie
Plasma Dynamics
Contains reports on three research projects.United States Atomic Energy Commission (Contract AT(30-1)-1842)United States Air Force, Air Force Cambridge Research Center (Contract AF19(604)-5992)United States Air Force, Air Force Cambridge Research Center (Contract AF19(604)-4551)National Science Foundation (Grant G-9930)Office of Naval Research through Project SQUID, Phase III, under contract with Massachusetts Institute of Technolog
Pion and neutron production by cosmic-ray muons underground
The production of positive pions and neutrons by cosmic muons at underground
sites of various depths is investigated. We first test the equivalent photon
method in the particular case of excitation by the muon. We find that
this method, when it neglects the momentum dependence of the transverse
response, reproduces remarkably well the theoretical muon cross-section. This
success has lead us to apply the method to higher energies, where it has not
been tested. We evaluate in this way the production of positive pions in liquid
scintillator from known photo-absorption cross-sections. At a shallow depth of
20 meters our estimate reproduces the measurement. As for the neutron emission,
we include the obvious sources, such as the giant-resonance excitation, the
quasi-deuteron process, the quasi- free pion production as well as neutrons
emitted following pion capture. Our evaluation underestimates the number of
neutrons produced and finds a too weak dependence on the depth. This suggests
that secondary neutron production is important at all depths.Comment: 29 pages, late
Ătude par diffusion des neutrons de la cinĂ©tique des moments magnĂ©tiques dans le fer au voisinage du point de Curie
We have worked out, by neutron scattering, the dynamics of the fluctuations of magnetization in iron near the Curie Point. Results support the validity of the Heisenberg model in iron.On étudie par diffusion des neutrons la cinétique des fluctuations d'aimantation dans le fer au voisinage du point de Curie. Les résultats confirment la validité de l'application du modÚle de Heisenberg au fer
The Interrelated Roles of Correlations in the Nuclear Equation of State and in Response Functions: Application to a Chiral Confining Theory
We study the role of short-range correlations, as well as pion and rho loops
governing long-range RPA correlations, in nuclear matter properties and
response functions. We use an adapted formulation of the Brueckner G-matrix
approach to generate a pair correlation function satisfying the
Beg--Agassi--Gal theorem, providing a natural cutoff to the loop integrals. We
present results for the case of a relativistic chiral theory, including the
effects of quark confinement and of the chirally broken vacuum in a version
where parameters are directly connected to QCD observables or constrained by
well-established hadron phenomenology. This provides a unified and coherent
view of the nuclear matter equation of state and the effect of correlations on
neutrino--nucleus scattering
The Interrelated Roles of Correlations in the Nuclear Equation of State and in Response Functions: Application to a Chiral Confining Theory
International audienceWe study the role of short-range correlations, as well as pion and rho loops governing long-range RPA correlations, in nuclear matter properties and response functions. We use an adapted formulation of the Brueckner G-matrix approach to generate a pair correlation function satisfying the Beg--Agassi--Gal theorem, providing a natural cutoff to the loop integrals. We present results for the case of a relativistic chiral theory, including the effects of quark confinement and of the chirally broken vacuum in a version where parameters are directly connected to QCD observables or constrained by well-established hadron phenomenology. This provides a unified and coherent view of the nuclear matter equation of state and the effect of correlations on neutrino--nucleus scattering