Perceptions of research

The term 'research' is rarely questioned. It is a term whose meaning seems to be implicitly understood. Certainly there is an institutional bureaucracy which supports 'research', and academic staff are rewarded for their strength in 'research'. But what is this research? It is likely that there are multiple understandings of 'research', but unless this diversity of understanding is recognised, it is difficult to have meaningful dialogue about it

Recent results in chiral effective field theory for the NN system

I describe recent progress towards a theory of the NN force which captures the consequences of QCD's chiral symmetry and the pattern of its breaking, and is formulated as an expansion in a ratio of low and high mass scales, M_{lo}/M_{hi}. This "chiral effective field theory" of the NN system is a firm foundation for explorations of nuclear structure and reactions that are grounded in QCD's low-energy symmetries. While calculations that use a ChiPT expansion for the NN potential have proven very successful, they can only be used with a narrow range of momentum-space cutoffs, which leaves the expansion parameter for observable quantities somewhat murky. Here we seek a truly systematic effective field theory for the NN amplitude, that is manifestly renormalization-group invariant at each order in a demonstrably perturbative expansion.Comment: Invited talk at the 7th International Workshop on Chiral Dynamics, August 6-10, 2012, Jefferson Lab, Newport News, VA. To appear in the proceedings. 12 pages, 5 figure

Electron-deuteron scattering in a relativistic theory of hadrons

We review a three-dimensional formalism that provides a systematic way to include relativistic effects including relativistic kinematics, the effects of negative-energy states, and the boosts of the two-body system in calculations of two-body bound-states. We then explain how to construct a conserved current within this relativistic three-dimensional approach. This general theoretical framework is specifically applied to electron-deuteron scattering both in impulse approximation and when the $\rho \pi \gamma$ meson-exchange current is included. The experimentally-measured quantities $A$, $B$, and $T_{20}$ are calculated over the kinematic range that is probed in Jefferson Lab experiments. The role of both negative-energy states and meson retardation appears to be small in the region of interest.Comment: 17 pages, 4 figures, uses BoxedEPS.tex, lamuphys.sty, bibnorm.sty. To appear in the proceedings of the Workshop on Electron-Nucleus Scattering held at the Elba International Physics Center, June 199

The nucleon-nucleon system in chiral effective theory

I discuss the conditions under which the application of chiral perturbation theory to the NN potential gives reliable results for NN scattering phase shifts. ChiPT also yields a convergent expansion for the deuteron charge operator. For cutoffs < 1 GeV, this produces precise predictions for deuterium's quadrupole and charge form factors in the range Q^2 < 0.25 GeV^2.Comment: 4 pages, 4 figures. Contribution to Proceedings of "12th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon", Williamsburg, VA, May 31-June 4, 201

Comment

With the proper role of judging so unsettled, it is hardly surprising that Americans also do not agree on what training, experience or temperament will produce the best judge