The Supersymmetry Les Houches Accord (SLHA) provides a universal set of conventions for conveying spectral and decay information for supersymmetry analysis problems in high energy physics. Here, we propose extensions of the conventions of the first SLHA to include various generalisations: the minimal supersymmetric standard model with violation of CP, R-parity, and flavour, as well as the simplest next-to-minimal model. IntroductionSupersymmetric (SUSY) extensions of the Standard Model rank among the most promising and well-explored scenarios for New Physics at the TeV scale. Given the long history of supersymmetry and the number of people working in the field, several different conventions for defining supersymmetric theories have been proposed over the years, many of which have come into widespread use. At present, therefore, no unique set of conventions prevails. In principle, this is not a problem. As long as everything is clearly and consistently defined, a translation can always be made between two sets of conventions. However, the proliferation of conventions does have some disadvantages. Results obtained by different authors or computer codes are not always directly comparable. Hence, if author/code A wishes to use the results of author/code B in a calculation, a consistency check of all the relevant conventions and any necessary translations must first be made -a tedious and error-prone task.To deal with this problem, and to create a more transparent situation for non-experts, the original SUSY Les Houches Accord (SLHA1) was proposed [1]. This accord uniquely defines a set of conventions for supersymmetric models together with a common interface between codes. The most essential fact is not what the conventions are in detail (they largely resemble those of [2]), but that they are consistent and unambiguous, hence reducing the problem of translating between conventions to a linear, rather than a factorial, dependence on the number of codes involved. At present, these codes can be categorised roughly as follows (see [3,4] for a review and on-line repository):• Spectrum calculators [5][6][7][8], which calculate the supersymmetric mass and coupling spectrum, assuming some (given or derived) SUSY-breaking terms and a matching to known data on the Standard Model parameters.• Observables calculators [9][10][11][12][13][14][15][16][17][18][19]; packages which calculate one or more of the following: collider production cross sections (cross section calculators), decay partial widths (decay packages), relic dark matter density (dark matter packages), and indirect/precision observables, such as rare decay branching ratios or Higgs/electroweak observables (constraint packages).• Monte-Carlo event generators [20][21][22][23][24][25][26][27][28], which calculate cross sections through explicit statistical simulation of high-energy particle collisions. By including resonance decays, parton showering, hadronisation, and underlying-event effects, fully exclusive final states can be studied, and, for instance, ...
High-precision analyses of supersymmetry parameters aim at reconstructing the fundamental supersymmetric theory and its breaking mechanism. A well defined theoretical framework is needed when higher-order corrections are included. We propose such a scheme, Supersymmetry Parameter Analysis SPA, based on a consistent set of conventions and input parameters. A repository for computer programs is provided which connect parameters in different schemes and relate the Lagrangian parameters to physical observables at LHC and high energy e + e − linear collider experiments, i.e., masses, mixings, decay widths and production cross sections for supersymmetric particles. In addition, programs for calculating high-precision low energy observables, the density of cold dark matter (CDM) in the universe as well as the cross sections for CDM search experiments are included. The SPA scheme still requires extended efforts on both the theoretical and experimental side before data can be evaluated in the future at the level of the desired precision. We take here an initial step of testing the SPA scheme by applying the techniques involved to a specific supersymmetry reference point.
An impact parameter representation for soft gluon radiation is applied to obtain both the initial decrease of the total cross-section (σ tot ) for proton-proton collisions as well as the later rise of σ tot with energy for both pp and pp. The non-perturbative soft part of the eikonal includes only limited low energy gluon emission and leads to the initial decrease in the proton-proton cross-section. On the other hand, the rapid rise in the hard, perturbative jet part of the eikonal is tamed into the experimentally observed mild increase by soft gluon radiation whose maximum energy rises slowly with energy.
We argue that known systematics of hadron cross sections may cause different particles to freeze out of the fireball produced in heavy-ion collisions at different times. We find that a simple model with two freezeout points is a better description of data than that with a single freezeout, while still remaining predictive. The resulting fits seem to present constraints on the late stage evolution of the fireball, including the tantalizing possibility that the QCD chiral transition influences the yields at sqrt(S)=2700 GeV and the QCD critical point those at sqrt(S)=17.3 GeV
The work contained herein constitutes a report of the "Beyond the Standard Model" working group for the Workshop "Physics at TeV Colliders", Les Houches, France, 26 May-6 June, 2003. The research presented is original, and was performed specifically for the workshop. Tools for calculations in the minimal supersymmetric standard model are presented, including a comparison of the dark matter relic density predicted by public codes. Reconstruction of supersymmetric particle masses at the LHC and a future linear collider facility is examined. Less orthodox supersymmetric signals such as non-pointing photons and Rparity violating signals are studied. Features of extra dimensional models are examined next, including measurement strategies for radions and Higgs', as well as the virtual effects of Kaluza Klein modes of gluons. An LHC search strategy for a heavy top found in many little Higgs model is presented and finally, there is an update on LHC Z ′ studies. XIV Radion Mixing Effects In The Two-Higgs-DoubletModel 74 XV Search For The Radion Decay φ → hh With γγ+bb, τ τ +bb And bb+bb Final States In CMS 80 XVI The Invisible Higgs Decay Width In The ADD Model At The LHC 86 XVII Determining the extra-dimensional location of the Higgs boson 92 XVIII The sensitivity of the LHC for TeV scale dimensions in dijet production 95 XIX Little Higgs Model: LHC Potential 99 XX Z ′ studies at the LHC: an update 104 5 Part I Abstract An accord specifying a unique set of conventions for supersymmetric extensions of the Standard Model together with generic file structures for (1) supersymmetric model specifications and input parameters, (2) electroweak scale supersymmetric mass and coupling spectra, and (3) decay tables is defined, to provide a universal interface between spectrum calculation programs, decay packages, and high energy physics event generators. AbstractWe present and describe an internet resource which allows the user to compare different calculations of MSSM spectra. After providing (currently mSUGRA) SUSY breaking input parameters, the spectra predicted by the publicly available programs ISASUGRA, SOFTSUSY, SPHENO and SUSPECT are output by the resource. The variance and range of results is also produced. AbstractWe compare the relic density of neutralino dark matter within the minimal supergravity model (mSUGRA) using four different public codes for supersymetric spectra evaluation.Abstract SFITTER is a new tool to determine supersymmetric model parameters from collider measurements. It allows to perform a grid search for the minimal χ 2 and/or a fit of a given model. Currently, the model parameters in the general MSSM or in a gravity mediated SUSY breaking model can be tested using a given set of mass, branching ratio and cross section measurements. AbstractWe present the Fortran code SDECAY, a program which calculates the decay widths and branching ratios of all supersymmetric particles in the Minimal Supersymmetric Standard Model, including higher order effects. The usual two-body decays of sfermions and gauginos as ...
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