The effective hyperKahler potential in the N = 2 supersymmetric QCD
Abstract
The effective lowenergy hyperK"ahler potential for a massive N=2 matter in the N=2 superQCD is investigated. The N=2 extended supersymmetry severely restricts that N=2 matter selfcouplings so that their exact form can be fixed by a few parameters, which is apparent in the N=2 harmonic superspace. In the N=2 QED with a single matter hypermultiplet, the oneloop perturbative calculations lead to the TaubNUT hyperK"ahler metric in the massive case, and a free metric in the massless case. It is remarkable that the naive nonrenormalization `theorem' does not apply. There exists a manifestly N=2 supersymmetric duality transformation converting the lowenergy effective action for the N=2 QED hypermultiplet into a sum of the quadratic and the improved (nonpolynomial) actions for an N=2 tensor multiplet. The duality transformation also gives a simple connection between the lowenergy effective action in the N=2 harmonic superspace and the component results.
 Publication:

Physics Letters B
 Pub Date:
 April 1997
 DOI:
 10.1016/S03702693(97)002645
 arXiv:
 arXiv:hepth/9701158
 Bibcode:
 1997PhLB..399...83K
 Keywords:

 High Energy Physics  Theory
 EPrint:
 12 pages, LaTeX, one figure and macros included