443 research outputs found
Discovering the Higgs Through Highly-Displaced Vertices
We suggest that the Higgs could be discovered at the Tevatron or the LHC
(perhaps at the LHCb detector) through decays with one or more substantially
displaced vertices from the decay of new neutral particles. This signal may
occur with a small but measurable branching fraction in the recently-described
``hidden valley'' models, hep-ph/0604261; weakly-coupled models with multiple
scalars, including those of hep-ph/0511250, can also provide such signals,
potentially with a much larger branching fraction. This decay channel may
extend the Higgs mass reach for the Tevatron. Unusual combinations of b jets,
lepton pairs and/or missing energy may accompany this signal.Comment: v2, minor improvements/clarifications, one added referenc
Finite Theories and Marginal Operators on the Brane
We show how to use D and NS fivebranes in Type IIB superstring theory to
construct large classes of finite N=1 supersymmetric four dimensional field
theories. In this construction, the beta functions of the theories are directly
related to the bending of branes; in finite theories the branes are not bent,
and vice versa. Many of these theories have multiple dimensionless couplings. A
group of duality transformations acts on the space of dimensionless couplings;
for a large subclass of models, this group always includes an overall
SL(2,\ZZ) invariance. In addition, we find even larger classes of theories
which, although not finite, also have one or more marginal operators.Comment: 32 pages, 13 figures, uses revte
The Higgs as a Portal to Plasmon-like Unparticle Excitations
A renormalizable coupling between the Higgs and a scalar unparticle operator
O_U of non-integer dimension d_U<2 triggers, after electroweak symmetry
breaking, an infrared divergent vacuum expectation value for O_U. Such IR
divergence should be tamed before any phenomenological implications of the
Higgs-unparticle interplay can be drawn. In this paper we present a novel
mechanism to cure that IR divergence through (scale-invariant) unparticle
self-interactions, which has properties qualitatively different from the
mechanism considered previously. Besides finding a mass gap in the unparticle
continuum we also find an unparticle pole reminiscent of a plasmon resonance.
Such unparticle features could be explored experimentally through their mixing
with the Higgs boson.Comment: 12 LaTeX pages, 2 figure
QCD String as Vortex String in Seiberg-Dual Theory
We construct a classical vortex string solution in a Seiberg-dual theory of
N=1 supersymmetric SO(N_c) QCD which flows to a confining phase. We claim that
this vortex string is a QCD string, as previouly argued by M.Strassler. In
SO(N_c) QCD, it is known that stable QCD strings exist even in the presence of
dynamical quarks. We show that our vortex strings are stable in the
Seiberg-dual theory.Comment: 15 pages, 1 figur
- …