2005/12/31 by Siba Prasad Das
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1103/physrevd.73.115004
published as Phys.Rev.D73:115004,2006 · 24 pages, 14 figures, added comments in sec.1, added 2 figures and comments in sec.2.1, conclusion and references updated
arxiv created 2006/04/24 · openalex publication_date 2006/06/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We reinvestigated the parameter space allowing a large branching ratio (BR) of the 4-body decay of the lighter top squark (\stackrel\texttildelowt1) accessible at Tevatron Run-II by imposing the lighter CP-even Higgs boson mass (m_h0) bound from LEP. Important constraints were obtained in mSUGRA as well as in the unconstrained supersymmetric models. Our results show that the prospect of searching the lighter top squark via the 4-body decay mode, in particular, the \ensuremathℓ+n\ensuremath-jets+\mathrmE\ensuremath\llap\not T signal, is not promising in mSUGRA due to the above bound on m_h0. The existing bounds on m_\stackrel\texttildelowt1 from Tevatron Run-I and LEP assuming 100% BR of the loop decay of \stackrel\texttildelowt1 are, therefore, valid to a good approximation. We also find that large BRs of the above 4-body decay are allowed in the unconstrained model over significant regions of parameter spaces and the possibility that this decay mode is the main discovery channel at Tevatron Run-II is open. We have briefly reviewed the theoretical uncertainties in the calculation of m_h0 and their consequences for the constraints obtained by us. We have commented upon, with illustrative examples, how the above parameter space is affected if future experiments push the Higgs boson mass bound upward.