N = 2 worldsheet instantons yield cubic selfdual YangMills
Abstract
When the gauge instantons on the N = 2 string worldsheet are properly included in the sum over topologies, the breaking of SO(2,2) Lorentz symmetry in R^{2,2} is parametrized by a spacetime twistor containing the string coupling and theta angle. The resulting (treelevel) effective action for the open string is not Yang's but Leznov's cubic action for selfdual YangMills in a lightcone gauge. In the closed case, Plebański's action for selfdual gravity gets modified analogously. In contrast to the N = 1 NSR string, picturechanging is not locally invertible, but produces a semiinfinite tower of massless physical states with everincreasing spin, perhaps related to harmonic superspace. A truncation yields the twofield action of Chalmers and Siegel.
 Publication:

Physics Letters B
 Pub Date:
 February 1997
 DOI:
 10.1016/S03702693(97)005959
 arXiv:
 arXiv:hepth/9704076
 Bibcode:
 1997PhLB..405...49L
 Keywords:

 High Energy Physics  Theory
 EPrint:
 9 pages, no figures, LaTeX (amsbsy,latexsym)