One-loop threshold effects in string unification
نویسندگان
چکیده
منابع مشابه
String Unification and Threshold Corrections
The interpretation of the apparent unification of gauge couplings within supersymmetric theories depends on uncertainties induced through heavy particle thresholds. While in standard grand unified theories these effects can be estimated easily, the corresponding calculations are quite complicated in string unified theories and do exist only in models with unbroken E6. We present results for hea...
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It is shown that the technique recently suggested by Lowell Brown for summing the tree graphs at threshold can be extended to calculate the loop effects. Explicit result is derived for the sum of one-loop graphs for the amplitude of threshold production of n on-mass-shell particles by one virtual in the unbroken λφ 4 theory. It is also found that the tree-level amplitude of production of n part...
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I discuss several aspects of strings as unified theories. After recalling the difficulties of the simplest supersymmetric grand unification schemes I emphasize the distinct features of string unification. An important role in constraining the effective low energy physics from strings is played by duality symmetries. The discussed topics include the unification of coupling constants (computation...
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ژورنال
عنوان ژورنال: Nuclear Physics B
سال: 1988
ISSN: 0550-3213
DOI: 10.1016/0550-3213(88)90526-3