Intrinsic operators for the electromagnetic nuclear current

The intrinsic electromagnetic nuclear meson exchange charge and current operators arising from a separation of the center-of-mass motion are derived for a one-boson-exchange model for the nuclear interaction with scalar, pseudoscalar and vector meson exchange including leading order relativistic terms. Explicit expressions for the meson exchange operators corresponding to the different meson types are given in detail for a two-nucleon system. These intrinsic operators are to be evaluated between intrinsic wave functions in their center-of-mass frame.Comment: 54 pages revtex, no figure

Few-Body Physics -- Then and Now

A summary of the XIV\underline{th} International Conference on Few-body Problems In Physics is given, with an emphasis on the important problems solved recently and the prognosis for the future of the field. Personal remarks and ``homework'' problem assignments are made.Comment: 17 pages, 1 fig., LA-UR-94-213

Three-Nucleon Forces for the New Millennium

Most nuclear physics ranges from insensitive to relatively insensitive to many-nucleon forces. The dominant ingredient in calculations of nuclear properties is the nucleon-nucleon potential. Three-nucleon forces nevertheless play an important role in nuclear physics because of the great precision of modern calculational methods for systems of relatively few nucleons. We explore the reasons why many-body forces are weak in nuclei by using a classification scheme for such forces that is based on dimensional power counting, which is used to organize chiral perturbation theory. An assessment will be made of how close we are to a ``standard'' three-nucleon force. Recent advances in determining the significance of three-nucleon forces will also be discussed.Comment: Invited talk presented at XVIth International Conference on Few-Body Problems in Physics, Taipei, Taiwan, March 6-10, 2000. -- 9 pages, latex, 3 figures -- To appear in Nuclear Physics A -- fleqn.sty, espcrc1.sty, and epsfig.sty require

Twenty-Five Years of Progress in the Three-Nucleon Problem

Twenty-five years ago the International Few-Body Conference was held in Quebec City. It became very clear at that meeting that the theoretical situation concerning the He3 and H3 ground states was confused. A lack of computational power prevented converged brute-force solutions of the Faddeev or Schroedinger equations, both for bound and continuum states of the three-nucleon systems. Pushed by experimental programs at Bates and elsewhere and facilitated by the rapid growth of computational power, converged solutions were finally achieved about a decade later. Twenty-five years ago the first three-nucleon force based on chiral-symmetry considerations was produced. Since then this symmetry has been our guiding principle in constructing three-nucleon forces and, more recently, nucleon-nucleon forces. We are finally nearing an understanding of the common ingredients used in constructing both types of forces. I will discuss these and other issues involving the few-nucleon systems and attempt to define the current state-of-the-art.Comment: Invited talk at Bates25 Symposium, MIT, November 3-5, 1999 - 13 pages, latex, 8 figures - To appear in AIP Conference Proceedings - epsfig.sty and aipproc.sty require

Triton calculations with the new Nijmegen potentials

Triton properties are calculated using new nucleon-nucleon potentials, which were fit to the world nucleon-nucleon data. All potentials are charge dependent and explicitly incorporate the mass difference between the charged and neutral pions. Three of these models have a nearly optimal chi**2 per degree of freedom and can therefore be considered as alternative partial wave analyses, which in quality can almost compete with the Nijmegen partial-wave analysis. The triton binding energy obtained with three local models (Nijm II, Reid93, AV18) can be summarized as 7.62 +_ 0.01 MeV, which is nearly 900 keV lower than experiment. The non-local model Nijm I binds by 7.72 MeV.Comment: 11 pages RevTex and 1 fig in PS, THEF-NYM-93-0

Dimensional Regularization and Nuclear Potentials

It is shown how nucleon-nucleon potentials can be defined in N dimensions, using dimensional regularization to continue amplitudes. This provides an easy way to separate out contact ($\delta$-function) terms arising from renormalization. An example is worked out several ways for the case of two scalar particles exchanged between nucleons, which involves a very simple loop calculation. This leads to a Feynman-parameterized representation for the nucleon-nucleon potential. Alternately, a dispersion representation can be developed leading to a different, though equivalent, form.Comment: 7 pages, latex, 2 figures -- To appear in Int. J. Mod. Phys. E -- epsfig.sty require

Nuclear Polarization Corrections to mu-d Atoms in Zero-Range Approximation

Nuclear polarization corrections to the 2P-2S Lamb shift in mu-d atoms are developed in order alpha^5 and are shown to agree with a recent calculation. The nuclear physics in the resulting corrections is then evaluated in zero-range approximation. The dominant part of the correction is very simple in form and differs from a recent potential model calculation by less than 1%. It is also demonstrated how the third-Zemach-moment contribution largely cancels against part of the polarization correction, as it did in e-d atoms and does so exactly for point-like nucleons. This suggests that it may be possible to reduce the uncertainty in the theory (of which nuclear polarization is the largest contributor) to less than 1%.Comment: 31 pages, 1 figur