The Gerasimov-Drell-Hearn sum rule
and the infinite-momentum limit
R. Pantförder - H. Rollnik - W. Pfeil
Physikalisches Institut der Universität Bonn,
Nußallee 12, D-53115 Bonn, Germany
Received: 25 March 1997
We study the current-algebra approach to the Gerasimov-Drell-Hearn sum rule, paying particular attention to the infinite-momentum limit. Employing the Weinberg-Salam model of weak interactions as a testing ground, we find that the legitimacy of the infinite-momentum limit is intimately connected with the validity of the naive equal-times algebra of electric charge densities. Our results considerably reduce the reliability of a recently proposed modification of the Gerasimov-Drell-Hearn sum rule, originating from an anomalous charge-density algebra.