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Title: Penguin-like diagrams from the standard model

The Standard Model is highly successful in describing the interactions of leptons and quarks. There are, however, rare processes that involve higher order effects in electroweak interactions. One specific class of processes is the penguin-like diagram. Such class of diagrams involves the neutral change of quark flavours accompanied by the emission of a gluon (gluon penguin), a photon (photon penguin), a gluon and a photon (gluon-photon penguin), a Z-boson (Z penguin), or a Higgs-boson (Higgs penguin). Such diagrams do not arise at the tree level in the Standard Model. They are, however, induced by one-loop effects. In this paper, we present an exact calculation of the penguin diagram vertices in the ‘tHooft-Feynman gauge. Renormalization of the vertex is effected by a prescription by Chia and Chong which gives an expression for the counter term identical to that obtained by employing Ward-Takahashi identity. The on-shell vertex functions for the penguin diagram vertices are obtained. The various penguin diagram vertex functions are related to one another via Ward-Takahashi identity. From these, a set of relations is obtained connecting the vertex form factors of various penguin diagrams. Explicit expressions for the gluon-photon penguin vertex form factors are obtained, and their contributions to themore » flavor changing processes estimated.« less
Authors:
 [1]
  1. High Impact Research, University of Malaya, 50603 Kuala Lumpur (Malaysia)
Publication Date:
OSTI Identifier:
22391508
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1657; Journal Issue: 1; Conference: PERFIK 2014: National Physics Conference 2014, Kuala Lumpur (Malaysia), 18-19 Nov 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; FEYNMAN DIAGRAM; FLAVOR MODEL; FORM FACTORS; GLUONS; HIGGS BOSONS; HIGGS MODEL; LEPTONS; PARTICLE INTERACTIONS; PHOTONS; QUARKS; RENORMALIZATION; STANDARD MODEL; VERTEX FUNCTIONS; Z NEUTRAL BOSONS