Changes between Version 8 and Version 9 of dim6top


Ignore:
Timestamp:
08/23/18 17:52:39 (12 months ago)
Author:
gdurieux
Comment:

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  • dim6top

    v8 v9  
    1111Top-quark FCNCs are also included by allowing one quark bilinear in each operator to break the U(2)q×U(2)u×U(2)d baseline flavour symmetry requirement and couple the third generation with either the first or the second. Operators with one light and one heavy quark, one light quark one heavy quark and two leptons, one light quark and three heavy quarks, three light and one heavy quark are included. The O(300) degrees of freedom are assigned a {{{FCNC=1}}} coupling order. Requiring {{{FCNC=0}}} at the generation level is required to not consider them.
    1212
    13 Two versions of the models are provided {{{dim6top_LO_UFO}}} and {{{dim6top_LO_UFO_each_coupling_order}}}. In the second one, each degree of freedom is assigned with an individual coupling order, like {{{DIM6_ctZ}}}, {{{DIM6_cQQ1}}}, or {{{FCNC_cqq11x3331}}}. This allows for the selection of individual degrees of freedom interferences at the generation level in {{{MG5_aMC@NLO}}}. The syntax:
     13Two versions of the models are provided {{{dim6top_LO_UFO}}} and {{{dim6top_LO_UFO_each_coupling_order}}}. In the second one, each degree of freedom is assigned an individual coupling order, like {{{DIM6_ctZ}}}, {{{DIM6_cQQ1}}}, or {{{FCNC_cqq11x3331}}}, in addition to the {{{DIM6}}} or {{{FCNC}}} one. This allows for the selection of individual degrees of freedom interferences at the generation level in {{{MG5_aMC@NLO}}}. The syntax:
    1414{{{
    15 > generate p p > t t~ FCNC=0 DIM6^2==1 DIM6_ctZ^2==1
    16 > generate p p > t t~ FCNC=0 DIM6^2==2 DIM6_ctZ^2==1 DIM6_ctW^2==1
     15> generate p p > t t~ FCNC=0 DIM6=1 DIM6^2==1 DIM6_ctZ^2==1
     16> generate p p > t t~ FCNC=0 DIM6=1 DIM6^2==2 DIM6_ctZ^2==1 DIM6_ctW^2==1
    1717}}}
    1818would for instance respectively retain only the interference between SM and {{{ctZ}}} amplitudes, and
    1919the interferences between {{{ctZ}}} and {{{ctW}}} amplitudes, in top pair production.
     20The {{{FCNC=0}}} specification excludes FCNC interactions, {{{DIM6=1}}} allows for at most one operator insertion at the amplitude level (to be removed to include multiple insertions too), {{{DIM6^2==n}}} specifies the overall EFT order of the selected squared amplitude, {{{DIM6_ctZ^2==n}}} specifies the order of the squared amplitude in the specific {{{ctZ}}} operator coefficient.
    2021
    2122Only tree-level simulation in the unitary gauge is possible. Loop induced couplings of the Higgs boson to pairs of gluons, photons, or {{{Zγ}}} are not included.
     
    4142
    4243Changelog:
     44- 2018-08-23: added back {{{DIM6}}} coupling orders to the {{{dim6top_LO_UFO_each_coupling_order}}} version (thanks to Jay Howarth)
    4345- 2018-06-06: corrected the Lorentz structures of the operators relative to {{{cbtud1}}} and {{{cbtud8}}} coefficients from scalar to vector (thanks to Céline Degrande)
    4446- 2018-05-28: moved the definition of 'ctA' below that of 'sw' and 'cw' in parameters.py, to avoid "MadGraph5Error : Unable to evaluate mdl_ctA = (mdl_ctW-mdl_cw*mdl_ctZ)/mdl_sw: raise error: name 'mdl_cw' is not defined" (thanks to Marcel Vos)