LQ_NLO

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.

VERSIONS

LQ_NLO-0.0.1 (upload date 11/2/2018)

DESCRIPTION

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.

NLO MODELS

The NLO UFO model file directories to be used with MADGRAPH5_AMC@NLO  are:

Leptokvark_NLO

NLO_LQ_R2

NLO_LQ_R2~

NLO_LQ_S1

NLO_LQ_S1~

NLO_LQ_S3

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]”).

LO MODELS

The leading-order Universal FeynRules Output (UFO) model file directories are:

LO_LQ_R2

LO_LQ_R2~

LO_LQ_S1

LO_LQ_S1~

LO_LQ_S3

VectorLQ_UFO

The leading-order UFO models, except for VectorLQ_UFO, can be found in the associated LO_MODEL directories that contain the following files:

Diag_CKM.rst 

(FeynRules restriction file for Cabbibo-Kobayashi-Maskawa (CKM) mixing matrix.)

Diag_PMNS.rst

(FeynRules restriction file for Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix.)

Massless.rst

(FeynRules restriction file for the Standard Model quark and charged lepton masses.)

SM_CKM_PMNS.fr

(FeynRules model file for the Standard Model with CKM and PMNS rotations in the up-type quark and the neutrino sectors, respectively.)

LO_LQ_(LQ_NAME).fr

(FeynRules model file for the scalar leptoquark (LQ_NAME)=(R2, R2~, S1, S1~, S3). LO stands for the leading order use.)

LO_LQ_(LQ_NAME).nb

(Mathematica file that generates UFO model LO_LQ_(LQ_NAME) via FeynRules.)

LO_LQ_(LQ_NAME)

(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.