QCD Interference Effects of Heavy Particles Below Threshold.pdfVIP

Caltech 68-2032, IASSNS 96/04 hep-ph/9601279 January 1996 6 9 9 1 QCD Interference Effects of Heavy Particles Below Threshold y a M 2 2 ⋆ 2 Per Kraus v 9 Department of Physics 7 2 Lauritsen Laboratory 1 0 California Institute of Technology 6 9 Pasadena, Cal. 91125 / h p - p e h : v † i Frank Wilczek X r a School of Natural Sciences Institute for Advanced Study Olden Lane Princeton, N.J. 08540 ⋆ Research supported in part by a DuBridge Fellowship and by DOE grant DE-FG03-92-ER40701 † Research supported in part by DOE grant DE-FG02-90ER40542. wilczek@sns.ias.edu ABSTRACT We consider how two classes of heavy particles: extra vector-like families, and strongly interacting superpartners, manifest themselves below threshold, by inter- ference of virtual loops with normal QCD processes. Quantitative estimates are presented. 2 1. Introduction Although the Standard Model has proven to be remarkably successful at presently accessible energies, there is universal agreement that it is incomplete – that new structure will emerge at higher energies. The existence of new heavy particles can be