Changes between Version 3 and Version 4 of FourFermionbbll
- Timestamp:
- Mar 24, 2021, 10:20:53 AM (4 years ago)
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FourFermionbbll
v3 v4 11 11 12 12 == Description of the model: 13 This is a Contact Interaction model with b-b-l-l Contact-Interaction terms, including interference with the SM. The effective Lagrangian of the model is described by:13 This is a Contact Interaction model with b-b-l-l terms, including interference with the SM, for all of the possible chirality combinations. The effective Lagrangian of the model is described by: 14 14 15 15 {{{ … … 19 19 \end{align*} 20 20 }}} 21 where here $\ell=e,\mu$, $\Lambda$ is the NP scale and we have summed over all possible chirality structures with $\eta_{ij}=\pm1$, which will be useful for accounting for constructive/destructive interference with the SM Drell-Yan process $pp\to Z/\gamma^*\to\ell^+\ell^- + X$.22 21 23 The behavior of the cross section for the corresponding $p p \to \ell^+ \ell^- + X$ processes can be parametrized by the contribution of three terms, which depend on the di-lepton invariant mass $m_{\ell \ell}$: 22 23 The behavior of the cross section can be parametrized by the contribution of three terms, which depend on the di-lepton invariant mass: 24 24 25 25 {{{ … … 30 30 }}} 31 31 32 where $\sigma^{SM}$ is the pure SM term and $\sigma^{NP}(\Lambda,m_{\ell \ell})$contain only the NP contributions:32 where the first term is the pure SM term and the second term contain only the NP contributions: 33 33 {{{ 34 34 #!latex … … 44 44 * [https://feynrules.irmp.ucl.ac.be/attachment/wiki/FourFermionbbll/bbll_UFO.zip bbll_UFO.zip] : the full model. 45 45 46 == Commands for MadGraph5_aMC@NLO :46 == Commands for MadGraph5_aMC@NLO, for a production of an electron and a positron with jets: 47 47 {{{ 48 48 define p = g u c d s b u~ c~ d~ s~ b~ … … 61 61 Where LambdaS is the scale of new physics in GeV, Celbbll is the bbee coupling with left-left chirality, etc. Note especially that the sign of Celbbll / Celbblr / Celbbrr / Celbbrl determines if the interference with the SM is constructive or destructive. 62 62 63 == Similarly, commands for MadGraph5_aMC@NLO, for a production of a muon and an anti-muon with jets: 64 {{{ 65 define p = g u c d s b u~ c~ d~ s~ b~ 66 define j = g u c d s b u~ c~ d~ s~ b~ 67 generate p p > mu+ mu- NP^2>0 68 add process p p > mu+ mu- j NP^2>0 69 add process p p > mu+ mu- j j NP^2>0 70 ... 71 set LambdaS ... 72 set Cmubbll ... 73 set Cmubblr ... 74 set Cmubbrr ... 75 set Cmubbrl ... 76 }}} 77 78 79 63 80 == References: 64 81 [1] Afik, Yoav and Bar-Shalom, Shaouly and Cohen, Jonathan and Rozen, Yoram. Phys. Lett. B. 807:135541, 2020, 1912.00425.
