LQ_NLO is a leptoquark toolbox for precision collider studies. It contains Universal FeynRules Output (UFO) model file directories for all scalar leptoquarks and one vector leptoquark to be used with MADGRAPH5_AMC@NLO. It also contains original FeynRules model files to allow for reusability and customisation. The main features of these UFO models and associated physics results are summarised in arXiv:1801.07641.
Please acknowledge arXiv:1801.07641 if you use the LQ_NLO material.
LQ_NLO-0.0.1 (upload date 11/2/2018)
LQ_NLO provides both the leading order (LO) and next-to-leading order (NLO) UFO model files to be used with MADGRAPH5_AMC@NLO. We describe the content of the latest LQ_NLO version, i.e., LQ_NLO-0.0.1, briefly in what follows.
The NLO UFO model file directories to be used with MADGRAPH5_AMC@NLO are:
All of these NLO models produce the same total inclusive cross section for the pair production of a given scalar leptoquark since the Yukawa coupling dependent t-channel is excluded. To generate numerical results for pair production with, for example, Leptokvark_NLO UFO model one should first import it in MADGRAPH5_AMC@NLO and subsequently execute “p p > lq lq~ [QCD] NP=0”. One can specify relevant parton distribution function sets and collider energies in run_card.dat of MADGRAPH5_AMC@NLO to generate customised numerical output.
Total inclusive cross section for the single leptoquark + lepton production depends on the quark flavour (but not the lepton flavour) the leptoquark couples to. For example, to generate NLO cross section with Leptokvark_NLO UFO model for a single scalar leptoquark production via strange (charm) quark one should import the model in MADGRAPH5_AMC@NLO and execute “p p > lq mu- $$ lq~ [QCD]” (“p p > lq vm $$ lq~ [QCD]”).
The leading-order Universal FeynRules Output (UFO) model file directories are:
The leading-order UFO models, except for VectorLQ_UFO, can be found in the associated LO_MODEL directories that contain the following files:
(FeynRules restriction file for Cabbibo-Kobayashi-Maskawa (CKM) mixing matrix.)
(FeynRules restriction file for Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix.)
(FeynRules restriction file for the Standard Model quark and charged lepton masses.)
(FeynRules model file for the Standard Model with CKM and PMNS rotations in the up-type quark and the neutrino sectors, respectively.)
(FeynRules model file for the scalar leptoquark (LQ_NAME)=(R2, R2~, S1, S1~, S3). LO stands for the leading order use.)
(Mathematica file that generates UFO model LO_LQ_(LQ_NAME) via FeynRules.)
(UFO model LO_LQ_(LQ_NAME), where (LQ_NAME)=(R2, R2~, S1, S1~, S3).)
Lagrangians of R2, R2~, S1, S1~, and S3 leptoquarks are given in Phys. Rept. 641 (2016) 1-68 (arXiv:1603.04993).
VectorLQ_UFO is the UFO model file for one particular vector leptoquark. The associated lagrangian is given in arXiv:1801.07641 and in FeynRules model file vleptokvark.fr.