ONE-LOOP AMPLITUDES IN THE HETEROTIC STRING

We calculate the one-loop amplitudes for the emission of four massless particles in the heterotic string model. In particular, we consider the amplitudes involving four gravitons and gauge bosons supermultiplets as well as those for the mixed processes. We also discuss their modular invariance and finiteness.

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One-loop string corrections to AdS amplitudes from CFT

Journal of High Energy Physics ◽

10.1007/jhep03(2021)038 ◽

2021 ◽

Vol 2021 (3) ◽

Cited By ~ 2

Author(s):

J.M. Drummond ◽

H. Paul

Keyword(s):

Stress Tensor ◽

Analytic Structure ◽

Position Space ◽

Yang Mills ◽

String Corrections ◽

The One ◽

Loop Amplitudes

Abstract We consider α′ corrections to the one-loop four-point correlator of the stress- tensor multiplets in $$ \mathcal{N} $$ N = 4 super Yang-Mills at order 1/N4. Holographically, this is dual to string corrections of the one-loop supergravity amplitude on AdS5 × S5. While this correlator has been considered in Mellin space before, we derive the corresponding position space results, gaining new insights into the analytic structure of AdS loop amplitudes. Most notably, the presence of a transcendental weight three function involving new singularities is required, which has not appeared in the context of AdS amplitudes before. We thereby confirm the structure of string corrected one-loop Mellin amplitudes, and also provide new explicit results at orders in α′ not considered before.

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FIVEBRANE STRUCTURES

Reviews in Mathematical Physics ◽

10.1142/s0129055x09003840 ◽

2009 ◽

Vol 21 (10) ◽

pp. 1197-1240 ◽

Cited By ~ 18

Author(s):

HISHAM SATI ◽

URS SCHREIBER ◽

JIM STASHEFF

Keyword(s):

String Theory ◽

Heterotic String ◽

Target Space ◽

Type Ii ◽

Anomaly Cancellation ◽

Heterotic String Theory ◽

Dual Version ◽

String Structure ◽

Topological Obstructions ◽

The One

We study the cohomological physics of fivebranes in type II and heterotic string theory. We give an interpretation of the one-loop term in type IIA, which involves the first and second Pontrjagin classes of spacetime, in terms of obstructions to having bundles with certain structure groups. Using a generalization of the Green–Schwarz anomaly cancellation in heterotic string theory which demands the target space to have a String structure, we observe that the "magnetic dual" version of the anomaly cancellation condition can be read as a higher analog of String structure, which we call Fivebrane structure. This involves lifts of orthogonal and unitary structures through higher connected covers which are not just 3- but even 7-connected. We discuss the topological obstructions to the existence of Fivebrane structures. The dual version of the anomaly cancellation points to a relation of string and Fivebrane structures under electric-magnetic duality.

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LITTLE HIGGS MODELS FOR NON-UNIVERSALITY FERMION

Modern Physics Letters A ◽

10.1142/s0217732305016816 ◽

2005 ◽

Vol 20 (21) ◽

pp. 1589-1603

Author(s):

YAN CHAI ◽

FURONG YIN

Keyword(s):

Higgs Mass ◽

Little Higgs ◽

Gauge Bosons ◽

New Models ◽

The One

We introduce the fermion non-universality into the little Higgs models SU (5)/ SO (5), SU (6)/ Sp (6) and study the phenomenology of the new models. We find that if we change the transform property of the observed fermions under the extended [ SU (2)× U (1)]2, the cancellation of the one-loop quadratically divergent correction to the Higgs mass arising from gauge bosons will not be changed, whereas the phenomenology at W-pole, Z-pole and low q2 will be changed.

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