Effective Field Theory in Nuclear Many-Body Physics

Recent progress in Lorentz-covariant quantum field theories of the nuclear many-body problem (quantum hadrodynamics, or QHD) is discussed. The importance of modern perspectives in effective field theory and density functional theory for understanding the successes of QHD is emphasized. To appear in: 150 Years of Quantum Many-Body Theory: A conference in honour of the 65th birthdays of John W. Clark, Alpo J. Kallio, Manfred L. Ristig, and Sergio Rosati.Comment: 10 pages, REVTeX 3.0 with epsf.sty, plus 2 figure

Recent Progress in Quantum Hadrodynamics

Quantum hadrodynamics (QHD) is a framework for describing the nuclear many-body problem as a relativistic system of baryons and mesons. Motivation is given for the utility of such an approach and for the importance of basing it on a local, Lorentz-invariant lagrangian density. Calculations of nuclear matter and finite nuclei in both renormalizable and nonrenormalizable, effective QHD models are discussed. Connections are made between the effective and renormalizable models, as well as between relativistic mean-field theory and more sophisticated treatments. Recent work in QHD involving nuclear structure, electroweak interactions in nuclei, relativistic transport theory, nuclear matter under extreme conditions, and the evaluation of loop diagrams is reviewed.Comment: 115 pages, REVTeX 3.0 with epsf.sty, ijmpe1.sty, srev.sty, symbols.sty, plus 10 figure

Search for the second forbidden beta decay of 8B to the ground state of 8Be

A significant decay branch of 8B to the ground state of 8Be would extend the solar neutrino spectrum to higher energies than anticipated in the standard solar models. These high-energy neutrinos would affect current neutrino oscillation results and also would be a background to measurements of the hep process. We have measured the delayed alpha particles from the decay of 8B, with the goal of observing the two 46-keV alpha particles arising from the ground-state decay. The 8B was produced using an in-flight radioactive beam technique. It was implanted in a silicon PIN-diode detector that was capable of identifying the alpha-particles from the 8Be ground state. From this measurement we find an upper limit (at 90% confidence level) of 7.3 x 10^{-5} for the branching ratio to the ground state. In addition to describing this measurement, we present a theoretical calculation for this branching ratio.Comment: One reference corrected. Minor edits in tex

Wybrane aspekty strategii politycznego public relations na przykładzie polskich pozaparlamentarnych partii lewicowych. Pierwsza dekada XXI wieku

The study of political parties’ political public relations strategies in terms of image building is an interesting and important topie. The aim of the article is a reflection on the place and role of non-parliamentary parties of the Polish left-wing scene. These groups are similar in their organizational structure, platforms (often strikingly similar to the mainstream parties or other peripheral leftist groups), financial situation (no secured budget, which is a significant obstacle in financing of election campaigns and maintaining proper structures).Badanie strategii politycznego public relations partii politycznych w zakresie budowania wizerunku jest ciekawym i ważnym tematem. Celem artykułu są rozważania na temat miejsca i roli partii pozaparlamentarnych, które kształtują polską lewicową scenę pozaparlamentarną. Ugrupowania te są do siebie podobne w kwestii budowanej struktury organizacyjnej, zapisu programowego (często łudząco przypominającego partie mainstreamowe lub statuty innych peryferyjnych ugrupowań lewicowych), sytuacji ekonomicznej (brak zaplecza budżetowego, co stanowi znaczną przeszkodę w finansowaniu kampanii wyborczych oraz utrzymywaniu poprawnych struktur partyjnych)

Bridging over p-wave pi-production and weak processes in few-nucleon systems with chiral perturbation theory

I study an aspect of chiral perturbation theory (\chi PT) which enables one to ``bridge'' different reactions. That is, an operator fixed in one of the reactions can then be used to predict the other. For this purpose, I calculate the partial wave amplitude for the p-wave pion production (pp\to pn\pi^+) using the pion production operator from the lowest and the next nonvanishing orders. The operator includes a contact operator whose coupling has been fixed using a matrix element of a low-energy weak process (pp\to de^+\nu_e). I find that this operator does not reproduce the partial wave amplitude extracted from experimental data, showing that the bridging over the reactions with significantly different kinematics is not necessarily successful. I study the dependence of the amplitude on the various inputs such as the NN potential, the \pi N\Delta coupling, and the cutoff. I argue the importance of a higher order calculation. In order to gain an insight into a higher order calculation, I add a higher order counter term to the operator used above, and fit the couplings to both the low-energy weak process and the pion production. The energy dependence of the partial wave amplitude for the pion production is described by the operator consistently with the data. However, I find a result which tells us to be careful about the convergence of the chiral expansion for the pp\to pn\pi^+ reaction.Comment: 30 pages, 13 figures, figures changed, compacted tex

Nuclear Hydrodynamics in a Relativistic Mean Field Theory

Paper by J. D. Waleck

Neutral-current neutrino-nucleus cross sections based on relativistic nuclear energy density functional

Background: Inelastic neutrino-nucleus scattering through the weak neutral-current plays important role in stellar environment where transport of neutrinos determine the rate of cooling. Since there are no direct experimental data on neutral-current neutrino-nucleus cross sections available, only the modeling of these reactions provides the relevant input for supernova simulations. Purpose: To establish fully self-consistent framework for neutral-current neutrino-nucleus reactions based on relativistic nuclear energy density functional. Methods: Neutrino-nucleus cross sections are calculated using weak Hamiltonian and nuclear properties of initial and excited states are obtained with relativistic Hartree-Bogoliubov model and relativistic quasiparticle random phase approximation that is extended to include pion contributions for unnatural parity transitions. Results: Inelastic neutral-current neutrino-nucleus cross sections for 12C, 16O, 56Fe, 56Ni, and even isotopes {92-100}Mo as well as respective cross sections averaged over distribution of supernova neutrinos. Conclusions: The present study provides insight into neutrino-nucleus scattering cross sections in the neutral channel, their theoretical uncertainty in view of recently developed microscopic models, and paves the way for systematic self-consistent large-scale calculations involving open-shell target nuclei.Comment: 25 pages, 9 figures, 2 tables, submitted to Physical Review

Electron Scattering for Nuclear and Nucleon Structure

The scattering of high-energy electrons from nuclear and nucleon targets provides a microscope for examining the structure of these tiny objects. The best evidence we have on what nuclei and nucleons actually look like comes from electron scattering. This 2001 book examines the motivation for electron scattering and develops the theoretical analysis of the process. It discusses our theoretical understanding of the underlying structure of nuclei and nucleons at appropriate levels of resolution and sophistication, and summarizes experimental electron scattering capabilities. Only a working knowledge of quantum mechanics and special relativity is assumed, making this a suitable textbook for graduate and advanced undergraduate courses. It will also provide a valuable summary and reference for researchers already working in electron scattering and other areas of nuclear and particle physics. This text has been reissued as an Open Access publication

Direct Urca processes on nucleons in cooling neutron stars

We use the field theoretical model to perform relativistic calculations of neutrino energy losses caused by the direct Urca processes on nucleons in the degenerate baryon matter. By our analysis, the direct neutron decay in the superdense nuclear matter under beta equilibrium is open only due to the isovector meson fields, which create a large energy gap between protons and neutrons in the medium. Our expression for the neutrino energy losses, obtained in the mean field approximation, incorporates the effects of nucleon recoil, parity violation, weak magnetism, and pseudoscalar interaction. For numerical testing of our formula, we use a self-consistent relativistic model of the multicomponent baryon matter. The relativistic emissivity of the direct Urca reactions is found substantially larger than predicted in the non-relativistic approach. We found that, due to weak magnetism effects, relativistic emissivities increase by approximately 40-50%, while the pseudoscalar interaction only slightly suppresses the energy losses, approximately by 5%.Comment: 21 pages, 2 figure