1993/08/12 by Jorge L. Lopez, J. Lopez, D. Nanopoulos +4 · 3 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1103/physrevd.49.355
published as Phys.Rev.D49:355-365,1994 · CTP-TAMU-40/93, Latex, 13 pages, 10 figures (available as uuencoded 0.963MB file from [email protected])
arxiv created 1993/08/12 · openalex publication_date 1994/01/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We consider a class of well-motivated string-inspired flipped SU(5) supergravity models which include four supersymmetry-breaking scenarios: no-scale, strict no-scale, dilaton, and special dilaton, such that only three parameters are needed to describe all new phenomena (mt,tan\ensuremathβ,m_\stackrel\ifmmode \else \~\fig). We show that the CERN LEP precise measurements of the electroweak parameters in the form of the \ensuremathε1 variable and the CLEO II allowed range for B(b\ensuremath→s\ensuremathγ) are at present the most important experimental constraints on this class of models. For mt\ensuremath\gtrsim155(165) GeV, the \ensuremathε1 constraint [at 90 (95)% C.L.] requires the presence of light charginos (m_x1^\ifmmode±\else\textpm\fi\ensuremath\lesssim50\ensuremath-100 GeV depending on mt). Since all sparticle masses are proportional to m_\stackrel\ifmmode \else \~\fig, m_x1^\ifmmode±\else\textpm\fi\ensuremath\lesssim100 GeV implies m_x10\ensuremath\lesssim55 GeV, m_x20\ensuremath\lesssim100 GeV, m_\stackrel\ifmmode \else \~\fig\ensuremath\lesssim360 GeV, m_\stackrel\ifmmode \else \~\fiq\ensuremath\lesssim350 (365) GeV, m_\stackrel\ifmmode \else \~\fieR\ensuremath\lesssim80 (125) GeV, m_\stackrel\ifmmode \else \~\fieL\ensuremath\lesssim120 (155) GeV, and m_\stackrel\ifmmode \else \~\fi\ensuremathν\ensuremath\lesssim100 (140) GeV in the no-scale (dilaton) flipped SU(5) supergravity model. The B(b\ensuremath→s\ensuremathγ) constraint excludes a significant fraction of the otherwise allowed region in the (m_x1^\ifmmode±\else\textpm\fi,tan\ensuremathβ) plane (irrespective of the magnitude of the chargino mass), while future experimental improvements will result in decisive tests of these models. In light of the \ensuremathε1 constraint, we conclude that the outlook for chargino and selectron detection at LEP II and at DESY HERA is quite favorable in this class of models.