N=31, D=11

We show that eleven-dimensional supergravity backgrounds with thirty one supersymmetries, N=31, admit an additional Killing spinor and so they are locally isometric to maximally supersymmetric ones. This rules out the existence of simply connected eleven-dimensional supergravity preons. We also show that N=15 solutions of type I supergravities are locally isometric to Minkowski spacetime.Comment: 17 page

Oxidizing SuperYang-Mills from (N=4,d=4) to (N=1,d=10)

We introduce superspace generalizations of the transverse derivatives to rewrite the four-dimensional N=4 Yang-Mills theory into the fully ten-dimensional N=1 Yang-Mills in light-cone form. The explicit SuperPoincare algebra is constructed and invariance of the ten-dimensional action is proved.Comment: 15 page

The reactions p + n --> d + omega and p + n --> d + phi near threshold

The reactions p+n-->d+omega and p+n-->d+phi are studied within a relativistic meson-exchange model of hadronic interactions. Predictions for the total cross sections and for the angular distributions of the vector mesons are presented. The resulting cross sections near threshold are around 10 - 30 microb for p+n-->d+omega$ and 200 - 250 nb for p+n-->d+phi. A moderate deviation of the cross section ratio sigma_{p+n-->d+phi} / sigma_{p+n-->d+omega} from that of the Okubo-Zweig-Iizuka rule is predicted.Comment: 12 pages, 7 figure

Extraction of a_nn from pi- d -> n n gamma

I present a calculation of the pi- d -> n n gamma reaction to third order in chiral perturbation theory. The short-distance physics of this reaction can be constrained by relating it to several important low-energy weak reactions. The theoretical error in a_nn extracted from this reaction can thus be reduced by a factor larger than three to +-0.05 fm.Comment: 2 pages, 2 eps figures, uses ws-procs9x6.cls, summary of invited talk at Chiral Dynamics 2006, Sept. 18-22, Durham/Chapel Hill, NC, to be published in the proceeding