Loops in Twistor Space
نویسنده
چکیده
We elucidate the one-loop twistor-space structure corresponding to momentum-space MHV diagrams. We also discuss the infrared divergences, and argue that only a limited set of MHV diagrams contain them. We show how to introduce a twistor-space regulator corresponding to dimensional regularization for the infrared-divergent diagrams. We also evaluate explicitly the ‘holomorphic anomaly’ pointed out by Cachazo, Svrček, and Witten, and use the result to define modified differential operators which can be used to probe the twistor-space structure of one-loop amplitudes. Laboratory of the Direction des Sciences de la Matière of the Commissariat à l’Energie Atomique of France.
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