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We discuss the effect of model space truncation on current conservation in quark model calculations., Comment: Latex, fbssuppl.sty. Contribution to Trento N* workshop

We discuss the role BLAST can play in the valuable kinematic window of low W and low Q^2., Comment: Latex, sprocl.sty, 2 figs. Contribution to MIT BLAST workshop

We investigate the model dependence and the importance of choice of database in extracting the {\it physical} nucleon-Delta(1232) electromagnetic transition amplitudes, of interest to QCD and baryon structure, from the pion photoproduction observables. The model dependence is found to be much smaller than the range of values obtained when different datasets are fitted. In addition, some inconsistencies in the current database are discovered, and their affect on the extracted transition amplitudes is discussed., Comment: Revtex, 2 figs., submitted to PRC

We limit ourselves basically to the SU(2) flavor sector of the CKM matrix, as probed in processes like nuclear $\beta$-decay, normal and radiative muon capture and neutrino reactions. Current interests in this primarily stem from our aspirations to interpret the weak form factors of the nucleon in the framework of QCD. Given a standard set of known form factors, we can look also in these processes for possible physics signals beyond the standard model., Comment: Invited talk, WEIN-98, Santa Fe, NM, June 15, 1998

Recently obtained polarized target and photon asymmetry data in eta photoproduction are shown to be very powerful, in conjunction with the differential cross-section data, in yielding model-insensitive constraints on the electrostrong parameters for the excitation and decay of the $N^{*}(1520)$ resonance. The extracted ratio of its electromagnetic helicity amplitudes, $A_{3/2}/A_{1/2}$, provides a critical test for the QCD-inspired hadron models., Comment: ReVTeX, 5 pages, corrected Table II and corresponding text

We consider prospects for studying the parity-violating electroweak excitation of the $\Delta (1232) $ resonance with polarized electron scattering (see nucl-th/9801025). We discuss the experimental feasibility and theoretical interpretability of such a measurement as well as the prospective implications for hadron structure theory. We also analyze the extent to which a PV $N\to\Delta$ measurement could constrain various extensions of the Standard Model., Comment: Talk given at the ECT/CEBAF Workshop on N* Physics, Trento, May 1998. Revtex (6 pages) with 2 postscript figures

We show that constraints from perturbative QCD calculations play a role in the nucleon to Delta(1232) electromagnetic transition even at moderate momentum transfer scales. The pQCD constraints, tied to real photoproduction data and unseparated resonance response functions, lead to explicit forms for the helicity amplitudes wherein the E2/M1 ratio remains small at moderately large momentum transfer., Comment: 4 pages, 2 figures, ReVTeX

We study total muon capture rates in light nuclei, taking into account renormalizations of the nuclear vector and axial vector strengths. We estimate the influence in the results of uncertainties of the spin-isospin interaction parameter and nuclear densities. A few of these reactions are theoretical benchmarks for physics involving searches for neutrino oscillations. New experiments in muon capture in several targets are suggested, in the light of some discrepancies with theory, crudeness of some experimental results and relevance to neutrino physics., Comment: 11 pages, Latex, no figures. Submitted to Phys.Lett.B

We study inclusive nu_e and nu_mu cross sections in C-12 in a theory that takes into account significant nuclear renormalization of strengths. Our calculation is in excellent agreement with the measured inclusive muon capture rate and the flux-averaged nu_e cross section, but overestimates the flux-averaged nu_mu inclusive cross section. These reactions are of crucial relevance to the issue of possible nu_mu to nu_e oscillations.We also calculate the flux-averaged cross sections in C-13 and Al-27, which are found to be consistent with the available experimental result., Comment: 11 pages, Latex. Submitted to Phys. Rev. C

We investigate the relations between the spin structure functions in the scaling and resonance regions. We examine the possible duality between the two, and draw inferences for the behavior of the asymmetry A_1 at large x. Finally, we point out the importance of additional polarized structure function data in the resonance region in terms of testing the hysteresis of perturbative physics., Comment: 4 pages, revtex, no figures

Relationships between mass intervals for free hadrons and in nuclei are studied in two theoretical approaches inspired by QCD: naive quark model and skyrmion model, taking one example each from mesons and baryons, that of pi-rho splitting in mesons, and nucleon-Delta splitting in baryons. Possible deconfinement effects in nuclei are examined., Comment: 16 pages, LaTex

We analyze the available data on eta photo- and electroproduction, around W~1535 MeV, in the framework of the effective Lagrangian approach, and extract, in a nearly model-independent fashion, the electrostrong amplitude for the gamma+N--> N*(1535)--> N+eta processes. Quark model approaches are shown to be quite inadequate to explain this property at all Q^2. In particular, at high Q^2, the extracted amplitude falls much slower than the predictions of the quark model, as a function of Q^2, a situation similar to the electroexcitation and decay of Delta(1232). A QCD explanation of these observations is urgently needed., Comment: 9 pages, 3 figures

We utilize precise weak interaction experiments on atomic muon capture and beta decay in the A = 3 nuclei, and take into account the effects of nuclear "anomalous thresholds" to extract the pseudoscalar pi-^3He-^3H coupling parameter, G^{eff}(m_\pi^2) = 45.8+- 2.4. This is an order of magnitude improvement in precision over that from the use of pion-nuclear scattering data and dispersion relations., Comment: to be published in Phys. Rev. Lett

We analyze the existing data on electroproduction of eta mesons in the region of W~1.5GeV, and extract an electrostrong form factor for the N*(1535) electroexcitation and decay into the eta-N channel, which is found to be relatively insensitive to the uncertainties of the effective Lagrangian approach. this extracted quantity is of interest in the QCD description of relevant baryons., Comment: 12 pages, two figures; to be published in Phys. Rev. Lett

From the new Mainz data of eta photoproduction off protons\cite{ref1} and deuterons\cite{ref2}, we can extract, via the effective Lagrangian approach (ELA)\cite{ref3}, the electrostrong parameters $\xi_{p}$ and $\xi_{n}$ for the N$^*$(1535) excitation. These parameters are, in units of $10^{-4} MeV^{-1}$, $(2.20\pm 0.15)$ and $(-1.86\pm 0.20)$ respectively. They yield the ratio of the helicity amplitudes for the excitation of N$^*$(1535) by photons off neutrons and protons to be $A^{n}_{1/2}/A^{p}_{1/2}=-0.84\pm 0.15$, a quantity of fundamental importance in the baryon structure. Best estimates in the quark model are close to this ratio., Comment: 1 fig. in ps.. It is an invited talk in Baryon'95, Santa Fe, Oct. 1995

Using the recent precise measurements of eta photopro- duction in proton and deuteron targets, we extract the ratio of the helicity amplitudes A^n_1/2 / A^p_1/2, for the excitation of N^*(1535), in the effective Lagrangian approach, It is fairly model-independent, free from the final-state interaction effects, and negative as predicted by the quark models. We stress the importance of polarization observables in further elucidation of the N^*(1520) photoexcitation amplitudes., Comment: 4 figures. It will be published in Phys. Lett. B

We extract a parameter $\xi$, a characteristic product of the strong and electromagnetic amplitudes for the N^*(1535), to be (2.20+-0.15) in unit of 10^(-4)MeV^(-1) from the new data on photoproduction of etas off proton., Comment: will be published in Phys. Rev. Lett

We discuss the eta and eta prime photo- and electroproduction as a way to probe the nucleon resonance structure., Comment: 6 pages,including 2 figs.(psfig)

We investigate the nucleon to Delta(1232) vector and axial vector amplitudes in the non-relativistic quark model of the Isgur-Karl variety. A particular interest is to investigate the SU(6) symmetry breaking, due to color hyperfine interaction. We compare the theoretical estimates to recent experimental investigation of the Adler amplitudes by neutrino scattering., Comment: \documentstyle[aps]{revtex}, 21pages; 11 postscript figures. Accepted for publication by Phys. Rev. C

We examine eta prime photoproduction, as a novel tool to study baryon resonances around 2 GeV, of particular interest to the quark shell model, which predicts a number of them. We find important roles of the form factors at the strong vertices, and show that the N^*(2080) can be probed efficiently by this reaction., Comment: Will be published in Phys. Rev. C

The existing inclusive electroproduction data base allow us a look at the issue of the relative behaviors of background and resonance excitations, a part of the Bloom-Gilman duality. These data lack accuracy at high Q^2, but establish PQCD scaling in the resonance region and even allow us a glimpse at the leading logarithmic corrections due to the gluon radiation and its possible quenching at large W and x. These should inspire better quality experimental tests at facilities like CEBAF II., Comment: 7 pages

The influence of the phi-meson on the nucleon properties in the chiral soliton model is discussed., Comment: 5 pages

We study log corrections to inelastic scattering at high Bjorken x for Q^2 from 1 to 21 GeV^2. At issue is the presence of log corrections, which can be absent if high x scattering has damped gluon radiation. We find logarithmic correction of the scaling curve extrapolated to low Q^2 improves the duality between it and the resonance plus background data in the Delta region, indicating log corrections exist in the data. However, at W > 2 GeV and high x, the data shows a (1-x)^3 form. Log corrections in one situation but not in another can be reconciled by a W- or Q^2- dependent higher twist correction., Comment: 13 pages, report nos. RPI-94-N90 and WM-94-106, revtex, two figures (available by fax or post)

We examine mass-corrected SU(6) symmetry predictions in the quark model relating vector, axial-vector and strong NN and N\Delta couplings, and demonstrate that the experimental N\Delta value is significantly higher than predicted in each case. Nevertheless the Goldberger-Treiman relation is satisfied in both sectors. Possible origins of the discrepancy of the quark model predictions with experiment are discussed., Comment: 22 pg. Latex file, figures available by request