A Search for Rare Decay D0 --> mu+mu - High Energy Physics UPRM
A Search for Rare Decay D0 --> mu+mu - High Energy Physics UPRM
A Search for Rare Decay D0 --> mu+mu - High Energy Physics UPRM
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Chapter 2Previous Works2.1 FCNC <strong>Decay</strong> TheoryThe fundamental work concerning FCNC decays is the famous paper by Glashow,Iliopoulos & Maiani in which they propose the existence of the charm quark and discusshow it can explain the suppression of FCNC decays [12] through what is now called theGIM mechanism. This has been discussed in Section 1.4.With respect Dacb d$efdhg to which is a charm FCNC decay, the GIM mechanismleads to suppression of the tree-level diagrams such as Figure 2.1.a. In a 1997 paper [14],Pakvasa presented the latest calculation <strong>for</strong> this process. He found that the short distanceeffects are dominated by internal s-quark loop diagrams which are suppressed by thesmallness of the s quark mass and by helicity considerations (Section 1.2.1).30
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