Browsing by Author "Ho, PM"

Now showing 1 - 3 of 3

High-energy zero-norm states and symmetries of string theory
(2006-05-05)
Chan, CT
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Ho, PM
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Lee, JC
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Teraguchi, S
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Yang, Y
High-energy limit of zero-norm states in the old covariant first quantized spectrum of the 26D open bosonic string, together with the assumption of a smooth behavior of string theory in this limit, are used to derive infinitely many linear relations among the leading high-energy, fixed-angle behavior of four-point functions of different string states. As a result, ratios among all high-energy scattering amplitudes of four arbitrary string states can be calculated algebraically and the leading order amplitudes can be expressed in terms of that of four tachyons as conjectured by Gross in 1988. A dual calculation can also be performed and equivalent results are obtained by taking the high-energy limit of Virasoro constraints. Finally, we compute all high-energy scattering amplitudes of three tachyons and one massive state at the leading order by saddle-point approximation to verify our results.
Solving all 4-point correlation functions for bosonic open string theory in the high-energy limit
(2005-10-03)
Chan, CT
;
Ho, PM
;
Lee, JC
;
Teraguchi, S
;
Yang, Y
We study the implication of decoupling zero-norm states in the high-energy limit, for the 26-dimensional bosonic open string theory. Infinitely many linear relations among 4-point functions are derived algebraically, and their unique solution is found. Equivalent results are also obtained by taking the high-energy limit of Virasoro constraints, and as an independent check, we compute all 4-point functions of 3 tachyons and an arbitrary massive state by saddle-point approximation. (c) 2005 Elsevier B.V. All rights reserved.
Ward identities and high energy scattering amplitudes in string theory
(2005-02-28)
Chan, CT
;
Ho, PM
;
Lee, JC
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電子物理學系
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Department of Electrophysics
High-energy limit alpha' --> infinity, of stringy Ward identities derived from the decoupling of two types of zero-norm states in the old covariant first quantized (OCFQ) spectrum of open bosonic string are used to check the consistency of saddle point calculations of high energy scattering amplitudes of Gross and Mende and Gross and Manes. Some inconsistencies of their saddle point calculations are found even for the string-tree scattering amplitudes of the excited string states. We discuss and calculate the missing terms of the calculation by those authors to recover the stringy Ward identities. In addition, based on the tree-level stringy Ward identities, we give the proof of a general formula, which was proposed previously, of all high energy four-point string-tree amplitudes of arbitrary particles in the string spectrum. In this formula all such scattering amplitudes are expressed in terms of those of tachyons as conjectured by Gross. The formula is extremely simple which manifestly demonstrates the universal high energy behavior of the interactions among all string states. (C) 2004 Elsevier B.V. All rights reserved.