Changes between Version 12 and Version 13 of TechniColor
 Timestamp:
 11/30/10 17:45:23 (10 years ago)
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TechniColor
v12 v13 26 26 * Next to Minimal Walking Technicolor (NMWT) is a similar extension, but based on the gauge group SU(3) technicolor with a doublet of Dirac fermions in the twoindex symmetric representation. 27 27 28 Our implementation makes use of the effective lowenergy model containing scalars, pseudoscalars, vector mesons and other fields predicted by the models. The implemented model is the simplest one, which contains only the composite states, which are expected to be the most important ones for collider phenomenology. These are the composite Higgs,and the vector and axial spinone resonances. For these states the effective theories of MWT and NMWT coincide.28 Our implementation makes use of the effective lowenergy model containing scalars, pseudoscalars, vector mesons and other fields predicted by the models. The implemented model is the simplest one, which contains only the lightest composite states, which are expected to be the most important ones for collider phenomenology. These are the composite Higgs and the vector and axial spinone resonances. For these states the effective theories of MWT and NMWT coincide. 29 29 30 30 … … 34 34 The most relevant references for this model implementation are: 35 35 36 * Phys. Rev. D 71, 051901 (2005) [http://arxiv.org/abs/hepph/0405209]  F. Sannino and K. Tuominen, ''Orientifold Theory Dynamics and Symmetry Breaking''. Note that the original name was ''Techniorientifold''.36 * Phys. Rev. D 71, 051901 (2005) [http://arxiv.org/abs/hepph/0405209]  F. Sannino and K. Tuominen, ''Orientifold Theory Dynamics and Symmetry Breaking''. This article introduces MWT and NMWT. Note that the original name was ''Techniorientifold''. 37 37 * Phys. Rev. D 76, 055005 ( 2007) [http://arxiv.org/abs/0706.1696]  R. Foadi, M.T. Frandsen, T. A. Ryttov, F. Sannino, ''Minimal Walking Technicolor: Set Up for Collider Physics''. This article derives the effective theory for MWT. 38 * Phys. Rev. D 79, 035006 (2009) [http://arxiv.org/abs/0809.0793] –A. Belyaev, R. Foadi, M.T. Frandsen, M. Jarvinen, A. Pukhov, F. Sannino, ''Technicolor Walks at the LHC''. This article presents the Lagrangian used in this implementation, and analyses LHC phenomenology by using the earlier LanHEP implementation.38 * Phys. Rev. D 79, 035006 (2009) [http://arxiv.org/abs/0809.0793]  A. Belyaev, R. Foadi, M.T. Frandsen, M. Jarvinen, A. Pukhov, F. Sannino, ''Technicolor Walks at the LHC''. This article presents the Lagrangian used in this implementation, and analyses LHC phenomenology by using the earlier LanHEP implementation. 39 39 40 40 See also: 41 41 42 42 * Phys. Lett. B597:8993,2004 [http://arxiv.org/abs/hepph/0406200]  Deog Ki Hong, Stephen D.H. Hsu, F. Sannino, ''Composite Higgs from higher representations''. 43 * Phys. Rev. D72:055001, 2005 [http://arxiv.org/abs/hepph/0505059] 43 * Phys. Rev. D72:055001, 2005 [http://arxiv.org/abs/hepph/0505059]  D.D. Dietrich, F. Sannino, K. Tuominen ''Light composite Higgs from higher representations versus electroweak precision measurements: Predictions for CERN LHC''. 44 44 * Phys. Rev. D 75, 085018 (2007) [http://arxiv.org/abs/hepph/0611341]  D. D. Dietrich and F. Sannino, ''Conformal window of SU(N) gauge theories with fermions in higher dimensional representations''. Note that the original name was ''Walking in the SU(N)''. 45 * For the construction at the Lagrangian level of the terms involving the spacetime epsilon tensor – representing the correct generalization of the WessZuminoWitten topological term – involving massive spin one fields see Acta Phys. Polon. B40:35333743, 2009; [http://arxiv.org/abs/0911.0931] –F. Sannino, ''Conformal Dynamics for TeV Physics and Cosmology''.45 * For the construction at the Lagrangian level of the terms involving the spacetime epsilon tensor – representing the correct generalization of the WessZuminoWitten topological term – involving massive spin one fields see Acta Phys. Polon. B40:35333743, 2009; [http://arxiv.org/abs/0911.0931]  F. Sannino, ''Conformal Dynamics for TeV Physics and Cosmology''. 46 46 47 47 … … 59 59 === Interfaces and related files === 60 60 61 * '''CalcHEP''': [/attachment/wiki/TechniColor/MWT_ch.zip (12.06.09)].62 * '''!MadGraph''': [/attachment/wiki/TechniColor/MWT_mg.zip (12.06.09)].61 * '''CalcHEP''': [/attachment/wiki/TechniColor/MWT_ch.zip MWT_ch.zip]. 62 * '''!MadGraph''': [/attachment/wiki/TechniColor/MWT_mg.zip MWT_mg.zip]. 63 63 * [/attachment/wiki/TechniColor/MWT_Calculator.zip MWT_Calculator.zip]: the calculator needed in !MadGraph in order to generate the param_card.dat for a different set of model parameters. 64 65 !FeynArts and Sherpa interfaces have not been tested. 64 66 65 67 … … 67 69 === Instructions and details === 68 70 69 The model file is loaded as usual. The attached Mathematica® notebook can be used for this task. The implementation supports only unitary gauge. The standard model section has only Cabibbo mixing, and the electron and the muon, as well as the up, down and strange quarks, are taken to be massless. 70 71 The model file is loaded as usual. The implementation supports only unitary gauge. The standard model section has only Cabibbo mixing, and the electron and the muon, as well as the up, down and strange quarks, are taken to be massless. 72 {{{ 73 #!comment 74 The attached Mathematica® notebook can be used for this task. 75 }}} 71 76 The calculator is needed by the !MadGraph implementation in order to change the parameters of the model. The directory is provided by a README file with the instructions on the usage. 72 77 73 The model file implements a (linear) effective theory for the spinzero and spinone sectors in technicolor, with the minimal SU(2),,L,, x SU(2),,R,, > SU(2),,V,, chiral symmetry breaking pattern. The strong technicolor interactions islinked to the electroweak sector as stipulated by the electroweak gauge transformations of the techniquarks. The modifications to the effective theory due to the electroweak interactions are mostly small. The composite scalar sector contains the composite Higgs boson and a triplet of massless technipions, which are eaten by the heavy gauge boson Z and W. The Higgs is expected to be relatively light (mass less than 500 GeV). We also have vector and axial spinone triplets, which mix with each other and with the electroweak gauge bosons.78 The model file implements a (linear) effective theory for the spinzero and spinone sectors in technicolor, with the minimal SU(2),,L,, x SU(2),,R,, > SU(2),,V,, chiral symmetry breaking pattern. The strong technicolor interactions are linked to the electroweak sector as stipulated by the electroweak gauge transformations of the techniquarks. The modifications to the effective theory due to the electroweak interactions are mostly small. The composite scalar sector contains the composite Higgs boson and a triplet of massless technipions, which are eaten by the heavy gauge boson Z and W. The Higgs is expected to be relatively light (mass less than 500 GeV). We also have vector and axial spinone triplets, which mix with each other and with the electroweak gauge bosons. 74 79 75 80 In addition to the standard model fermions, we thus have the following new particles: … … 81 86 * Charged heavy vectors R,,2,,^+^, R,,2,,^^ 82 87 83 The numbering convention for the heavy spinone states is such that R,,1,, is always the lighte r one. When the mass scale is below 1 TeVR,,1,, (R,,2,,) has larger component of the axial (vector) spinone composite state than of the vector (axial) state. When masses are increased to about 2 TeV, the situation is reversed.88 The numbering convention for the heavy spinone states is such that R,,1,, is always the lightest one. When the mass scale is below 1 TeV, R,,1,, (R,,2,,) has larger component of the axial (vector) spinone composite state than of the vector (axial) state. When masses are increased to about 2 TeV, the situation is reversed. 84 89 85 90 Using the effective theory introduces several new coupling constants. These can be constrained by linking to the underlying gauge theory via the Weinberg sum rules and the definition of the electroweak S parameter. After taking into account the Weinberg sum rules, the free parameters can be expressed in terms of: … … 89 94 * S: The (contribution of the lowest spinone states to the) S parameter. Recommended values come from naive estimates of the S parameter (calculation of techniquark loops), which gives S=0.15 for MWT and S=0.3 for NMWT. 90 95 * MH: The mass of the composite Higgs boson. 91 * rs: Parametrizes the couplings of the Higgs to the composite spinone states. Expected to be O(1).96 * rs: Parametrizes the couplings of the Higgs to the composite spinone states. Expected to be of order 1. 92 97 93 98 … … 95 100 === Validation === 96 101 97 The implementation of the following MWTCprocesses through the FeynRules interface was crosschecked with the already existing implementation in LanHEP (see references):102 The implementation of the following processes through the FeynRules interface was crosschecked with the already existing implementation in LanHEP (see references): 98 103 99 * pp>jj at 1400 GeV 100 * pp>mu+mu at 1400 GeV 104 * pp>jj at 14 TeV 105 * pp>mu+mu at 14 TeV 106 107 Among others, also the processes 108 109 * e+e>mu+mu at 14 TeV 110 * uu~>hZ at 14 TeV 111 112 were crosschecked between the !MadGraph and CalcHEP implementations. 113 114 Standard model processes like 115 * gg>gg 116 * ug>ug 117 * ud>us 118 were checked by comparing to the standard model implementation both in CalcHEP and in !MadGraph. 101 119 102 120 Furthermore, the matrix elements generated for … … 106 124 * uu~>!r1>dd~ 107 125 * l+l>!r1>uu~g 108 * l+vl>W>W H and lvl>W+>W+H126 * l+vl>W>Wh and lvl>W+>W+h 109 127 110 128 were checked by hand for a few phase space points. 129 130 Values of constrained parameters (e.g. rotation matrices) in CalcHEP, some randomly chosen Lagrangian terms, as well as all the partial widths for the decay of any of the composite states to any two particles, were checked against the earlier LanHEP implementation. 111 131 112 132 … … 118 138 119 139 !HiggsEffective.fr has to be loaded together with the FeynRules file for the MWT model, i.e. using the command {{{LoadModel[HiggsEffective.fr, MWT.fr]}}} where MWT.fr indicates the name of the MWT model file. 120 The value of the effective coupling coincides with the full one loop result, and depends on the values assumed by the other parameters of the model. For practical reasons though the effective coupling is introduced as an external parameter. Anyway its value doesn't need to be introduced at the Lagrangian level (i.e. in the FeynRules file) but will be calculated by the modified calculator for MadGraph, that computes its value based on the full one loop result. Therefore this extension can be used currently only with MadGraph. Note that the effective coupling is independent of the new dynamics because the Higgsfermions couplings are not modified in the MWT implementation respect to the SM. 140 [[BR]] 141 The value of the effective coupling is a function of the other parameters of the model, that has been calculated in full generality at the one loop order. For practical reasons though the effective coupling is declared as an external parameter. Anyway its correct value doesn't need to be introduced in the FeynRules file but it will be computed by the modified calculator for !MadGraph. Therefore this extension can be currently used only with !MadGraph. 142 [[BR]] 143 Note that the effective coupling is independent of the new dynamics because the Higgsfermions couplings are not modified in the MWT implementation with respect to the SM.