1,198 research outputs found

    Simulating Supersymmetry with ISAJET 7.0/ ISASUSY 1.0

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    We review the physics assumptions and input used in ISAJET~7.0 / ISA\-SUSY~1.0 that are relevant for simulating fundamental processes within the framework of the Minimal Supersymmetric Standard Model (MSSM) at ppˉp\bar p and pppp colliders. After a brief discussion of the underlying MSSM framework, we discuss event simulation and list the sparticle production processes and decay modes that have been incorporated into our calculations. We then describe how to set up and run an ISAJET / ISASUSY job and the user input and output formats. The ISAJET program is sufficiently flexible that some non-minimal supersymmetry scenarios may be simulated as well. Finally, plans for future upgrades which include the extension to e+e−e^+ e^- collisions, are listed.Comment: 17 pages, FSU-HEP-930329 UH-511-764-9

    Integration of GPS and GIS in Mapping of Secondary Schools in Akure South Local Government Area of Ondo State Nigeria

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    The study aims at integrating GPS and GIS in the Mapping of secondary schools in Akure South Local Government Area of Ondo State with a view to identify, map, and create a database for both private and government secondary schools within the study area. A total number of 56 schools were identified. Garmin Map 76CSX hand-held GPS was used in acquiring their positions (coordinate in Eastings and Northings) within the study area while the attribute datawas obtained from the ministry of education. The satellite image of the study area was downloaded from Google Earthwebsite. ArcGIS 10.1 was used for the production of the digital map while Microsoft Access 2007 was used in generating the database. In performing the query, the query builder in ArcView was used. The result of the database reveals that the number of secondary schools owned by the government and private individuals are 26 and 30 respectively, representing 45% and 54% respectively of the total secondary schools within the study area. The created database reveals that some schools have complete facilities with specific laboratories for each of the science subjects while others have incomplete equipment or lack specific laboratory facilities for practical subjects. Furthermore, the study reveals that there are more private schools than government owned secondary schools within the study area

    Yukawa Coupling Unification in Supersymmetric Models

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    We present an updated assessment of the viability of t-b-tau Yukawa coupling unification in supersymmetric models. For the superpotential Higgs mass parameter mu>0, we find unification to less than 1% is possible, but only for GUT scale scalar mass parameter m_{16}~8-20 TeV, and small values of gaugino mass m_{1/2}<400 GeV. Such models require that a GUT scale mass splitting exists amongst Higgs scalars with m_{H_u}^2<m_{H_d}^2. Viable solutions lead to a radiatively generated inverted scalar mass hierarchy, with third generation and Higgs scalars being lighter than other sfermions. These models have very heavy sfermions, so that unwanted flavor changing and CP violating SUSY processes are suppressed, but may suffer from some fine-tuning requirements. While the generated spectra satisfy b->s gamma and (g-2)_mu constraints, there exists tension with the dark matter relic density unless m_{16}<3 TeV. These models offer prospects for a SUSY discovery at the Fermilab Tevatron collider via the search for chargino_1 neutralino_2 -> 3 leptons events, or via gluino pair production. If mu<0, Yukawa coupling unification to less than 5% can occur for m_{16} and m_{1/2}>1-2 TeV. Consistency of negative mu Yukawa unified models with b->s gamma, (g-2)_mu, and relic density all imply very large values of m_{1/2} typically greater than about 2.5 TeV, in which case direct detection of sparticles may be a challenge even at the LHC.Comment: 38 pages, 15 figures. Fig.15 changed, some references were added. A copy of the paper with better resolution figures can be found at http://www.hep.fsu.edu/~balazs/Physics/Papers/2003

    Probing SUSY beyond the reach of LEP2 at the Fermilab Tevatron: low |M_3| dark matter models

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    In supersymmetric models where the magnitude of the GUT scale gaugino mass parameter M_3 is suppressed relative to M_1 and M_2, the lightest neutralino can be a mixed higgsino-bino state with a thermal relic abundance in agreement with the WMAP central value for \Omega_{\rm CDM} h^2 and consistent with all other phenomenological constraints. In these models, the gluino can be as light as 200 GeV without conflicting with the LEP2 bounds on the chargino mass. Thus, gluino pair production can be accessible at the Fermilab Tevatron at high rates. In this framework, gluinos decay radiatively with a large branching fraction to a gluon plus a neutralino. We find that experiments at the Fermilab Tevatron, with 5 fb^{-1} of integrated luminosity, will be sensitive to gluino pair production in the m_{\tg}\sim 200-350 GeV range via the multi-jet +etmissing and multi-jet +\ell^+\ell^- + etmissing channels at the 5\sigma level, while trilepton signatures are expected to be below this level of detectability. Dilepton mass edges from both \tz_2 and \tz_3 decays may be measurable in the dilepton + multi-jet +etmissing channel.Comment: 14 pages including 6 EPS figure

    LHC discovery potential for supersymmetry with \sqrt{s}=7 TeV and 5-30 fb^{-1}

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    We extend our earlier results delineating the supersymmetry (SUSY) reach of the CERN Large Hadron Collider operating at a centre-of-mass energy \sqrt{s}=7 TeV to integrated luminosities in the range 5 - 30 fb^{-1}. Our results are presented within the paradigm minimal supergravity model (mSUGRA or CMSSM). Using a 6-dimensional grid of cuts for the optimization of signal to background ratio -- including missing E_T-- we find for m(gluino) \sim m(squark) an LHC 5\sigma SUSY discovery reach of m(gluino) \sim 1.3,\ 1.4,\ 1.5 and 1.6 TeV for 5, 10, 20 and 30 fb^{-1}, respectively. For m(squark)>> m(gluino), the corresponding reach is instead m(gluino)\sim 0.8,\ 0.9,\ 1.0 and 1.05 TeV, for the same integrated luminosities.Comment: 7 pages with 2 .eps figure. In version 2, a new figure has been added along with associated discussio

    Addressing \mu-b_\mu and proton lifetime problems and active neutrino masses in a U(1)^\prime-extended supergravity model

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    We present a locally supersymmetric extension of the minimal supersymmetric Standard Model (MSSM) based on the gauge group SU(3)C×SU(2)L×U(1)Y×U(1)′SU(3)_C\times SU(2)_L\times U(1)_Y\times U(1)^\prime where, except for the supersymmetry breaking scale which is fixed to be ∼1011\sim 10^{11} GeV, we require that all non-Standard-Model parameters allowed by the {\it local} spacetime and gauge symmetries assume their natural values. The U(1)′U(1)^\prime symmetry, which is spontaneously broken at the intermediate scale, serves to ({\it i}) explain the weak scale magnitudes of μ\mu and bμb_\mu terms, ({\it ii}) ensure that dimension-3 and dimension-4 baryon-number-violating superpotential operators are forbidden, solving the proton-lifetime problem, ({\it iii}) predict {\it bilinear lepton number violation} in the superpotential at just the right level to accommodate the observed mass and mixing pattern of active neutrinos (leading to a novel connection between the SUSY breaking scale and neutrino masses), while corresponding trilinear operators are strongly supppressed. The phenomenology is like that of the MSSM with bilinear R-parity violation, were the would-be lightest supersymmetric particle decays leptonically with a lifetime of ∼10−12−10−8\sim 10^{-12}-10^{-8} s. Theoretical consistency of our model requires the existence of multi-TeV, stable, colour-triplet, weak-isosinglet scalars or fermions, with either conventional or exotic electric charge which should be readily detectable if they are within the kinematic reach of a hadron collider. Null results of searches for heavy exotic isotopes implies that the re-heating temperature of our Universe must have been below their mass scale which, in turn, suggests that sphalerons play a key role for baryogensis. Finally, the dark matter cannot be the weakly interacting neutralino.Comment: 33 pages, 2 figures, Discussion on proton decay and radiative neutrino masses augmented, and references adde
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