Semiclassical and quantum decay of massive strings

by Jorge RUSSO (CERN)

Tuesday 4 Mar 2003, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

While massive string states are a key ingredient for the consistency of string theory, little is known about the way they decay. The important study of their decay properties present a major difficulty given by the high degeneracy of the decay products. For large quantum numbers, a generic massive string state (in any superstring theory) can be described semiclassically by a soliton solution, and their decay properties admit a simple description. This approximation holds for most very massive string states. In the same large mass limit, also the one-loop quantum calculation simplifies: the infinite products in the integral over modular parameters can be reorganized and saddle point techniques can be used to evaluate the integrals. Such quantum calculation becomes exact for large masses, and exactly matches the semiclassical calculation, despite the fact they involve completely different computations. For the first time, explicit solutions describing string evolution and splitting into new strings will be constructed.