22 research outputs found
Neutrino Physics: an Update
We update our recent didactic survey of neutrino physics, including new
results from the Sudbury Neutrino Observatory and KamLAND experiments, and
recent constraints from WMAP and other cosmological probes.Comment: latex; 19 pages; five figure
Neutrino Physics
The basic concepts of neutrino physics are presented at a level appropriate
for integration into elementary courses on quantum mechanics and/or modern
physics.Comment: Prepared for the American Journal of Physics; 50 pages; 11 figures
(10 included); late
Piecewise moments method: Generalized Lanczos technique for nuclear response surfaces
For some years Lanczos moments methods have been combined with large-scale shell-model calculations in evaluations of the spectral distributions of certain operators. This technique is of great value because the alternative, a state-by-state summation over final states, is generally not feasible. The most celebrated application is to the Gamow-Teller operator, which governs β decay and neutrino reactions in the allowed limit. The Lanczos procedure determines the nuclear response along a line q = 0 in the (ω,q) plane, where ω and q are the energy and three-momentum transferred to the nucleus, respectively. However, generalizing such treatments from the allowed limit to general electroweak response functions at arbitrary momentum transfers seems considerably more difficult: The response function must be determined over the entire (ω,q) plane for an operator O(q) that is not fixed, but depends explicitly on q. Such operators arise in any semileptonic process in which the momentum transfer is comparable with (or larger than) the inverse nuclear size. Here we show, for Slater determinants built on harmonic-oscillator basis functions, that the nuclear response for any multipole operator O(q) can be determined efficiently over the full response plane by a generalization of the standard Lanczos moments method. We describe the piecewise moments method and thoroughly explore its convergence properties for the test case of electromagnetic responses in a full sd-shell calculation of ^(28)Si. We discuss possible extensions to a variety of electroweak processes, including charged- and neutral-current neutrino scattering
From Hadrons to Nuclei: Crossing the Border
The study of nuclei predates by many years the theory of quantum
chromodynamics. More recently, effective field theories have been used in
nuclear physics to ``cross the border'' from QCD to a nuclear theory. We are
now entering the second decade of efforts to develop a perturbative theory of
nuclear interactions using effective field theory. This work describes the
current status of these efforts.Comment: 141 pages, 58 figs, latex. To appear in the Boris Ioffe Festschrift,
ed. by M. Shifman, World Scientifi
Piecewise moments method: Generalized Lanczos technique for nuclear response surfaces
For some years Lanczos moments methods have been combined with large-scale shell-model calculations in evaluations of the spectral distributions of certain operators. This technique is of great value because the alternative, a state-by-state summation over final states, is generally not feasible. The most celebrated application is to the Gamow-Teller operator, which governs β decay and neutrino reactions in the allowed limit. The Lanczos procedure determines the nuclear response along a line q = 0 in the (ω,q) plane, where ω and q are the energy and three-momentum transferred to the nucleus, respectively. However, generalizing such treatments from the allowed limit to general electroweak response functions at arbitrary momentum transfers seems considerably more difficult: The response function must be determined over the entire (ω,q) plane for an operator O(q) that is not fixed, but depends explicitly on q. Such operators arise in any semileptonic process in which the momentum transfer is comparable with (or larger than) the inverse nuclear size. Here we show, for Slater determinants built on harmonic-oscillator basis functions, that the nuclear response for any multipole operator O(q) can be determined efficiently over the full response plane by a generalization of the standard Lanczos moments method. We describe the piecewise moments method and thoroughly explore its convergence properties for the test case of electromagnetic responses in a full sd-shell calculation of ^(28)Si. We discuss possible extensions to a variety of electroweak processes, including charged- and neutral-current neutrino scattering
Deep Underground Science and Engineering Laboratory - Preliminary Design Report
The DUSEL Project has produced the Preliminary Design of the Deep Underground
Science and Engineering Laboratory (DUSEL) at the rehabilitated former
Homestake mine in South Dakota. The Facility design calls for, on the surface,
two new buildings - one a visitor and education center, the other an experiment
assembly hall - and multiple repurposed existing buildings. To support
underground research activities, the design includes two laboratory modules and
additional spaces at a level 4,850 feet underground for physics, biology,
engineering, and Earth science experiments. On the same level, the design
includes a Department of Energy-shepherded Large Cavity supporting the Long
Baseline Neutrino Experiment. At the 7,400-feet level, the design incorporates
one laboratory module and additional spaces for physics and Earth science
efforts. With input from some 25 science and engineering collaborations, the
Project has designed critical experimental space and infrastructure needs,
including space for a suite of multidisciplinary experiments in a laboratory
whose projected life span is at least 30 years. From these experiments, a
critical suite of experiments is outlined, whose construction will be funded
along with the facility. The Facility design permits expansion and evolution,
as may be driven by future science requirements, and enables participation by
other agencies. The design leverages South Dakota's substantial investment in
facility infrastructure, risk retirement, and operation of its Sanford
Laboratory at Homestake. The Project is planning education and outreach
programs, and has initiated efforts to establish regional partnerships with
underserved populations - regional American Indian and rural populations