Unitary string amplitudes

Berera, Arjun

doi:10.1016/0550-3213(94)90057-4

Unitary string amplitudes

Arjun Berera
(
- UC, Berkeley and
- LBL, Berkeley
)

May, 1992

26 pages

Published in:

Nucl.Phys.B 411 (1994) 157-180

DOI:

10.1016/0550-3213(94)90057-4

Report number:

UCB-PTH-92-11,
LBL-32248

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Abstract: (Elsevier)

The scattering amplitudes of string theory are divergent when the Riemann surface has a particular degeneracy associated with loops becoming infinitely long. These divergences originate from multiparticle intermediate states. The string amplitudes do not have the imaginary part required by unitarity. We give a prescription for defining string amplitudes that extends to all tachyon-free string theories. Explicit applications of our procedure are given at one-loop level for the Green-Schwarz and Neveu-Schwarz-Ramond theories. Our procedure is valid for higher loops also. However, only some simple features for this situation are explicitly discussed.

string model
scattering amplitude: higher-order
higher-order: scattering amplitude
analytic properties
Riemann surface

References(4)

Figures(0)

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,
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Arjun Berera
(
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)

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•
DOI:
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