Short-distance structure of hadrons in supersymmetric QCD

Abstract

Assuming supersymmetry to be a real symmetry in particle physics, we study the short-distance internal structure of nucleons (structure functions at large Q 2). We determine all calculable quantities in the leading logarithm approximation and discuss the N = 1 supersymmetry relations between them. Further relations are obtained by observing that the N = 1 supersymmetric lagrangian becomes N = 2 supersymmetric if the quarks and squarks are (formally) put into the adjoint representation of SU(3) colour. From the calculated elements of the 4 × 4 matrix of the Q 2 evolution kernels and knowing the quark and gluon distributions at low Q 2 we are able to determine the quark, squark, gluon, and gluino distributions for Q 2 above the threshold for the production of supersymmetric particles. We find that in the asymptotic limit ( Q 2 → ∞) the quarks carry only 2 3 of the nucleon's baryon number and the remaining 1 3 is carried by the squarks. We also find that in this limit 0.32 of the longitudinal nucleon momentum is carried by gluons, 0.08 by gluinos, 0.36 by the quarks and 0.24 by the squarks.