Physics – High Energy Physics – High Energy Physics - Phenomenology
Scientific paper
1999-08-16
Nucl.Phys. B569 (2000) 391-416
Physics
High Energy Physics
High Energy Physics - Phenomenology
24 pages, LaTeX
Scientific paper
10.1016/S0550-3213(99)00770-1
We consider the calculation of threshold effects due to Kaluza Klein and winding modes in string theory. We show that for a large radius of compactification these effects may be approximated by an effective field theory applicable below the string cut-off scale. Using this formalism we show that the radiative contribution to gauge couplings involving only massive Kaluza Klein and winding modes may be calculated to all orders in perturbation theory and determine the full two loop contribution involving light modes and estimate the magnitude of the higher-order contributions. For the case of the weakly coupled heterotic string we also discuss how an improved calculation can be made incorporating the string theory threshold corrections which avoids the limitations of the effective field theory approach. Using this formalism we determine the implications for gauge coupling unification for one representative model including the effects of two loop corrections above the compactification scale. Finally we discuss the prospects for gauge unification in Type I models with a low string scale and point out potential fine tuning problems in this case.
Ghilencea Dumitru
Ross Graham
No associations
LandOfFree
String thresholds and Renormalisation Group Evolution does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with String thresholds and Renormalisation Group Evolution, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and String thresholds and Renormalisation Group Evolution will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-124753