A unified approach to electron and neutrino elastic scattering off nuclei with an application to the study of the axial structure

We show a relationship between elastic electron scattering observables and the elastic neutrino cross section that provides a straightforward determination of the latter from experimental data of the former and relates their uncertainties. An illustration of this procedure is presented using a Hartree-Fock mean field for the nuclear structure of a set of even-even nuclear targets, using the spectra of the neutrinos produced in pion decay at rest. We also analyze the prospects to measure the incoherent axial contribution to the neutrino elastic scattering in odd targets

Meson-Exchange Currents and the Strangeness Radius of 4he

Meson-exchange current contributions to the strangeness radius of $^4$He are computed in the one-boson exchange approximation. It is found that these contributions introduce a \lapp10\% correction to the one-body contribution. They should not, therefore, hamper the extraction of the nucleon strangeness radius from the parity-violating electron-$^4$He asymmetry.Comment: 9 tex pages and 2 figures (not included, available from authors on request), CEBAF Preprint #TH-93-16 and MIT Preprint CTP#223

Was the Accounting Profession Really That Bad?

To gain insight into the extent of malpractice in the State of California prior to the Passage of Sarbanes-Oxley, we examined the nature and magnitude of complains filed with the California Board of Accountancy (CBA) against both licensed and unlicensed accountants during the fiscal years 2000, 2001, and 2002. The CBA currently licenses and regulates over 73,000 licenses, with 1,431 complaints filed during the period reviewed. Disciplinary actions were taken against 283 different licensees for the three fiscal years reviewed. SEC issues were involved in 19 cases, theft or embezzlement 46 cases, public accounting malpractice 146 cases, improper retention of client records 11 cases, cheating on the CPA examination 9 cases, and miscellaneous other 52 cases. Over half of the complaints involved public accounting issues. Audit related complaints accounted for 48%, tax related complaints 36%, and compilations or reviews accounted for 16% of the complaints. These statistics were in line with the experience of the AICPA Professional Liability program. Within the above sections, the paper contains specifics with regards to the most common problems identified as a result of this work. While a number of interesting facts were discovered, one item of particularly interest was the significant number of claims that involved non-profit organizations. CBA administrators do not believe there is any greater tendency for non profit reporting versus for profit reporting, thus appearing to indicate this is just an area that has a greater possibility of accounting malpractice

Coincidence charged-current neutrino-induced deuteron disintegration for 2H216O^2\mathrm{H}_2{^{16}}\mathrm{O}

Semi-inclusive charge-changing neutrino reactions on targets of heavy water are investigated with the goal of determining the relative contributions to the total cross section of deuterium and oxygen in kinematics chosen to emphasize the former. The study is undertaken for conditions where the typical neutrino beam energies are in the few GeV region, and hence relativistic modeling is essential. For this, the previous relativistic approach for the deuteron is employed, together with a spectral function approach for the case of oxygen. Upon optimizing the kinematics of the final-state particles assumed to be detected (typically a muon and a proton) it is shown that the oxygen contribution to the total cross section is suppressed by roughly an order of magnitude compared with the deuterium cross section, thereby confirming that CC$\nu$ studies of heavy water can effectively yield the cross sections for deuterium, with acceptable backgrounds from oxygen. This opens the possibility of using deuterium to determine the incident neutrino flux distribution, to have it serve as a target for which the nuclear structure issues are minimal, and possibly to use deuterium to provide improved knowledge of specific aspects of hadronic structure, such as to explore the momentum transfer dependence of the isovector axial-vector form factor of the nucleon

Semi-inclusive charged-current neutrino-nucleus reactions

The general, universal formalism for semi-inclusive charged-current (anti)neutrino-nucleus reactions is given for studies of any hadronic system, namely, either nuclei or the nucleon itself. The detailed developments are presented with the former in mind and are further specialized to cases where the final-state charged lepton and an ejected nucleon are presumed to be detected. General kinematics for such processes are summarized and then explicit expressions are developed for the leptonic and hadronic tensors involved and for the corresponding responses according to the usual charge, longitudinal and transverse projections, keeping finite the masses of all particles involved. In the case of the hadronic responses, general symmetry principles are invoked to determine which contributions can occur. Finally, the general leptonic-hadronic tensor contraction is given as well as the cross section for the process

Coincidence charged-current neutrino-induced deuteron disintegration

Deuteron disintegration by charged-current neutrino (CC$\nu$) scattering offers the possibility to determine the energy of the incident neutrino by measuring in coincidence two of the three resulting particles: a charged lepton (usually a muon) and two protons, where we show that this channel can be isolated from all other, for instance, from those with a pion in the final state. We discuss the kinematics of the process for several detection scenarios, both in terms of kinematic variables that are natural from a theoretical point of view and others that are better matched to experimental situations. The deuteron structure is obtained from a relativistic model (involving an approximation to the Bethe-Salpeter equation) as an extension of a previous, well-tested model used in deuteron electrodisintegration. We provide inclusive and coincidence (semi-inclusive) cross sections for a variety of kinematic conditions, using the plane-wave impulse approximation, introducing final-state hadronic exchange terms (plane-wave Born approximation) and final-state hadronic interactions (distorted-wave Born approximation).Comment: 31 pages, 14 figure

Parity violation in quasielastic electron-nucleus scattering within the relativistic impulse approximation

We study parity violation in quasielastic (QE) electron-nucleus scattering using the relativistic impulse approximation. Different fully relativistic approaches have been considered to estimate the effects associated with the final-state interactions. We have computed the parity-violating quasielastic (PVQE) asymmetry and have analyzed its sensitivity to the different ingredients that enter in the description of the reaction mechanism: final-state interactions, nucleon off-shellness effects, current gauge ambiguities. Particular attention has been paid to the description of the weak neutral current form factors. The PVQE asymmetry is proven to be an excellent observable when the goal is to get precise information on the axial-vector sector of the weak neutral current. Specifically, from measurements of the asymmetry at backward scattering angles good knowledge of the radiative corrections entering in the isovector axial-vector sector can be gained. Finally, scaling properties shown by the interference $\gamma-Z$ nuclear responses are also analyzed.Comment: 15 pages, 11 figure