Sparticle and Higgs-boson production and detection at CERN LEP II in two supergravity models

Journal Article · Mon Nov 01 04:00:00 EST 1993 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.48.4062· OSTI ID:5993019

Lopez, J L; Nanopoulos, D V; Pois, H; Wang, X; Zichichi, A ^[1]

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1. Center for Theoretical Physics, Department of Physics, Texas A M University, College Station, Texas 77843-4242 (United States) Astroparticle Physics Group, Houston Advanced Research Center (HARC), The Woodlands, Texas 77381 (United States) CERN Theory Division, 1211 Geneva 23 (Switzerland) CERN, Geneva (Switzerland)

We study the most promising signals for supersymmetry at CERN LEP II in the context of two well-motivated supergravity models: (i) the minimal SU(5) supergravity model including the stringent constraints from proton stability and a not too young universe and (ii) a recently proposed string-inspired no-scale flipped SU(5) supergravity model. Our computations span the neutralino, chargino, slepton, and Higgs sectors together with their interconnections in this class of models. We find that the number of mixed'' (1-lepton+2-jets+[ital p]) events occurring in the decay of pair-produced charginos ([chi][sub 1][sup [plus minus]]) is generally significant (per [ital scrL]=100 pb[sup [minus]1]) for both models and that these predictions do not overlap. That is, if [ital m][sub [chi]1][sup [plus minus]][lt]100 GeV then LEP II should be able to exclude at least one of the two models. In the no-scale flipped SU(5) model we find that the number of acoplanar dielectron events from selectron pair production should allow for exploration of selectron masses up to the kinematical limit and chargino masses indirectly as high as 150 GeV. We find that the cross section [ital e][sup +][ital e[minus]][r arrow][ital Z][sup *][ital h] deviates negligibly from the SM result in the minimal model, whereas it can be as much as 1/3 lower in the flipped model. The usually neglected invisible mode [ital h][r arrow][chi][sub 1][sup 0][chi][sub 1][sup 0] can erode the preferred [ital h][r arrow]2 jets signal by as much as 40% in these models. We conclude that the charged slepton sector is a deeper probe than the chargino, neutralino, or Higgs sectors of the flipped SU(5) model at LEP II, while the opposite is true for the minimal SU(5) model where the slepton sector is no probe at all.

• DOE Contract Number: FG05-91ER40633
• OSTI ID: 5993019
• Journal Information: Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 48:9; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

662210 -- Specific Theories & Interaction Models
662440* -- Properties of Other Particles Including Hypothetical Particles-- (1992-)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYONS
COMPOSITE MODELS
CROSS SECTIONS
DETECTION
ELEMENTARY PARTICLES
EXTENDED PARTICLE MODEL
FERMIONS
FIELD THEORIES
HADRONS
HIGGS BOSONS
LIE GROUPS
MATHEMATICAL MODELS
NUCLEONS
PARTICLE MODELS
PARTICLE PRODUCTION
POSTULATED PARTICLES
PROTONS
Pa
Particle Systematics-- Unified Theories & Models-- (1992-)
QUARK MODEL
STABILITY
STRING MODELS
SU GROUPS
SU-5 GROUPS
SUPERGRAVITY
SUPERSYMMETRY
SYMMETRY
SYMMETRY GROUPS
UNIFIED-FIELD THEORIES