2006/01/17 by Patrick Meade, Matthew Reece · 4 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Higgs boson #Invariant mass #Large Hadron Collider #Particle physics #Particle physics theoretical and experimental studies #Phenomenology (philosophy) #Physics #Physics beyond the Standard Model #Tevatron #WIMP #hep-ph
paper · pdf · doi:10.1103/physrevd.74.015010
published as Phys.Rev.D74:015010,2006 · 28 pages, 5 figures
arxiv created 2006/01/17 · openalex publication_date 2006/07/19 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
If one takes naturalness seriously and also assumes a weakly coupled extension of the standard model (SM) then there are expectations for phenomenology that can be inferred in a model-independent framework. The first such expectation is that there is likely to be some colored particle with mass O(TeV) that cancels the top loop contribution to the quadratic divergence of the Higgs mass. In this paper we begin a model-independent analysis of the phenomenology of this ``top partner,'' t^\ensuremath'. We make one additional assumption that it is odd under a parity which is responsible for the stability of a WIMP dark matter candidate, N. We focus on three questions to be explored at the LHC: discovery opportunities, mass determination, and spin determination of this top partner. We find that within a certain region of masses for the t^\ensuremath' and N, t^\ensuremath't^\ensuremath' is easily discovered in the tt+2N decay with the tops decaying fully hadronically. We show that without having to rely on other channels for new physics that for a given t^\ensuremath' spin the masses of t^\ensuremath' and N can be measured using kinematic information (e.g. average \mathrmE\ensuremath\llap\not T or HT) and total cross section. A degeneracy due to the spin remains, but with several hundred fb^\ensuremath-1 of luminosity we demonstrate potentially useful new methods for determining the t^\ensuremath' spin over a wide range of masses. Our methods when could be useful for distinguishing supersymmetric and nonsupersymmetric models.