Gravitational effects in ultrahigh-energy string scattering
Loading...
Date
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Description
Ultrahigh-energy string scattering is investigated to clarify the relative role of string and gravitational effects, and their possible contributions to nonlocal behavior. Different regimes can be characterized by varying the impact parameter at fixed energy. In the regime where momentum transfers reach the string scale, string effects appear subdominant to higher-loop gravitational processes, approximated via the eikonal. At smaller impact parameters, "diffractive" or "tidal" string excitation leads to processes dominated by highly excited strings. However, new evidence is presented that these excitation effects do not play a direct role in black hole formation, which corresponds to breakdown of gravitational perturbation theory and appears to dominate at sufficiently small impact parameters. The estimated amplitudes violate expected bounds on high-energy behavior for local theories.
19 pages, harvmac. v2: fixed typos, added refs and discussion of longitudinal spread. v3: minor changes to agree with published version
19 pages, harvmac. v2: fixed typos, added refs and discussion of longitudinal spread. v3: minor changes to agree with published version