Toponium tests of top quark Higgs bags

Abstract

Recently it has been suggested that top quarks, or very massive fourth generation quarks, might surround themselves with a Higgs “bag” of deformation of the Higgs expectation value from its vacuum magnitude. In this paper we address the question of whether such non-linear Higgs-top interaction effects are subject to experimental test. We first note that if top quarks were necessarily accompanied by Higgs “bags”, then top quark weak decay would involve the sudden disruption of the Higgs “bag”, with copious production of physical Higgs particles accompanying the decay. We then examine the effects that such Higgs “bags” would produce on the spectrum of toponium, where the two bound top (anti) quarks, and their “bags”, overlap. We numerically evaluate the effects that the non-linear feedback in the Higgs-toponium system would have on the energy level splittings of the toponium bound states, and find that for allowed values of the top and Higgs mass the effect is negligible, thus indicating that even in this favourable circumstance Higgs “bag” formation around top quarks does not observably occur. Finally, we consider the case of a second Higgs doublet, allowing the possibility of enhanced couplings for one of the physical Higgs to top. Even in this non-standard scenario the effects are minimal, and we infer the general absence of observable effects at any level that might suggest the utility of considering top quarks to be accompanied by Higgs “bags”.