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Compton Scattering Sum Rules for Massive Vector Bosons

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Lagrangian in the limit of natural values. At tree level, the GDH can be confirmed.<br />

However, at one-loop we find that the effective Lagrangian is not complete. An<br />

additional self-interaction tadpole is needed to derive the anomalous magnetic moment.<br />

Additionally, <strong>for</strong> the quadrupole sum rule, it is found that even at tree level polarization<br />

effects might give a contribution, since the QSR yields a finite, non-zero result.<br />

The SU(2) Yang-Mills ansatz and the resulting tadpole contribution is given in chapter 5,<br />

where the complete Yang-Mills result at one-loop is discussed. As a concluding remark,<br />

the anomalous magnetic moment <strong>for</strong> j = 1 is compared qualitatively to the value<br />

<strong>for</strong> spin 1 /2. The relation to the experimental results <strong>for</strong> deuteron and W bosons is<br />

commented upon.<br />

The conclusion is followed by an appendix containing Feynman rules <strong>for</strong> both theories,<br />

the vertex diagrams, and some helpful references on the handling of loop integrals.<br />

Tools<br />

In the course of this work, two major tools have been used in the calculation process.<br />

Besides manual calculations, we used Nikhef’s FORM algebra manipulation program<br />

[Ver00] and Wolfram’s Mathematica 6 suite. FORM has primarily been used to<br />

derive the structures used in this work, i.e. the diagrams and the LETs, as well as<br />

to confirm the Ward-Takahashi-identities. In Mathematica we derived the amplitude<br />

decompositions and identified the LETs with the appropriate dispersion relations. The<br />

sum rule tree-level integrations were done in Mathematica, which we also used to plot<br />

the integrands.<br />

For the creation of this work free software was used where possible. The thesis was<br />

written in L A TEX using Kile and Aquamacs Emacs. The document is based on a<br />

template by T. Beranek. It uses the KOMA-Script scrbook class. Also, the physicsrelated<br />

TEX package PhysTEX by F. Jung [Jun02] was used, with some personal<br />

extensions. All Feynman diagrams and other illustrations were either created in<br />

JaxoDraw [BT04, BCKT08] or done using PGF and TikZ [Tan06].<br />

Notation and Conventions<br />

Throughout this thesis, the Einstein summation convention is used, i.e. summation is<br />

implied over indices which appear twice. If not mentioned otherwise, latin letters imply<br />

ix

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