QCD corrections to properties of technipions in technicolor theories

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1990
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Slaven, David
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Bing-Lin Young
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Physics and Astronomy
Physics and astronomy are basic natural sciences which attempt to describe and provide an understanding of both our world and our universe. Physics serves as the underpinning of many different disciplines including the other natural sciences and technological areas.
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In this work we calculate QCD corrections to technipion processes in a one family technicolor model. Our approach is to use an effective technipion Lagrangian analogous to the effective Lagrangian of QCD. The effective Lagrangian includes the Wess-Zumino-Witten Lagrangian (adapted to technicolor), and we gauge the QCD subgroup of the chiral symmetry to obtain couplings between the technipions and gluons. Here we examine processes involving the P[superscript]0[superscript]', a colorless, neutral, electroweak singlet, and the lightest technipion in a one family technicolor model. In addition to the Wess-Zumino-Witten Lagrangian, we assume couplings between technipions and ordinary fermions, due to a higher scale extended technicolor interaction;As a part of our work, we develop a technique, using the Slavnov-Taylor identities, for easily removing the unphysical polarization states from multi-gluon calculations. We apply our technique later in this work;Next we calculate three body decay modes and compare them to the lowest order two body decays which have been previously studied. The decays we examine are ones which are QCD corrections to lowest order two body decays. We find that these decays are large, mainly because the QCD coupling constant, [alpha][subscript] s is not small. We also examine the possibility of producing the P[superscript]0[superscript]' at high transverse momentum at hadron colliders (a similar calculation). This rate is also large, especially at a very high energy machine such as the proposed SSC, where P[superscript]0[superscript]' production at high p[subscript]⊥ will exceed W[superscript]± production;Finally, we consider QCD corrections to two body decays involving products of tree level Feynman diagrams and one loop diagrams. This leads us to the problems of ultraviolet and infrared divergences. Since the theory is non-renormalizable, we can't expect to be able to eliminate the ultraviolet divergences, but in fact they are surprisingly well behaved, with only one ultraviolet divergence left uncanceled. With a judicious choice of renormalization scheme, we also find that the infrared divergences between the two body and three body decay cancel. We use dimensional regularization for the divergences, and renormalize with the [overline] MS scheme. In the end, we find that these corrections are also quite large, comparable to the lowest order decays. Furthermore, we find that due to the entanglement of the infrared divergences, it is useless to attempt to classify the decays into two body or three body decays in a perturbative scheme such as we employ here.

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Mon Jan 01 00:00:00 UTC 1990