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Dark-matter production through loop-induced processes at the LHC: the s-channel mediator case.

Mattelaer O, Vryonidou E - Eur Phys J C Part Fields (2015)

Bottom Line: We show how studies relevant for mono-X searches at the LHC in simplified models featuring a dark-matter candidate and an s-channel mediator can be performed within the MadGraph5_aMC@NLO framework.We focus on gluon-initiated loop-induced processes, mostly relevant to the case where the mediator couples preferentially to third generation quarks and in particular to the top quark.Our implementation allows us to study signatures at hadron colliders involving missing transverse energy plus jets or plus neutral bosons ([Formula: see text]), possibly including the effects of extra radiation by multi-parton merging and matching to the parton shower.

View Article: PubMed Central - PubMed

Affiliation: Institute for Particle Physics Phenomenology (IPPP), Durham University, Durham, DH1 3LF UK.

ABSTRACT

We show how studies relevant for mono-X searches at the LHC in simplified models featuring a dark-matter candidate and an s-channel mediator can be performed within the MadGraph5_aMC@NLO framework. We focus on gluon-initiated loop-induced processes, mostly relevant to the case where the mediator couples preferentially to third generation quarks and in particular to the top quark. Our implementation allows us to study signatures at hadron colliders involving missing transverse energy plus jets or plus neutral bosons ([Formula: see text]), possibly including the effects of extra radiation by multi-parton merging and matching to the parton shower.

No MeSH data available.


Related in: MedlinePlus

Missing  distribution for  for the scalar mediator of 200 GeV. The  distributions are shown for two cuts on the transverse momentum of the jet
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Fig19: Missing distribution for for the scalar mediator of 200 GeV. The distributions are shown for two cuts on the transverse momentum of the jet

Mentions: For this kind of process, it is important to investigate the importance of additional QCD radiation, similarly to what we observe in the SM for [25]. We illustrate this effect in Fig. 19 by showing in the ‘resonant’ case (200 GeV scalar mediator) the missing transverse momentum for the zero and one-jet multiplicities. We see that these contributions are not suppressed compared to the 0-jet ones. In the SM this effect, i.e. the importance of the 1-jet contribution, is even more pronounced at high as the 0-jet amplitude is extremely suppressed by the cancellation between box and triangle diagrams. In any case, it might be important experimentally to perform inclusive searches rather than applying a jet veto, as such a cut will eliminate these enhanced 1-jet contributions. A more accurate prediction of the shapes can be provided by LO merging and matching to the PS, a procedure that is automatic in MG5aMC.


Dark-matter production through loop-induced processes at the LHC: the s-channel mediator case.

Mattelaer O, Vryonidou E - Eur Phys J C Part Fields (2015)

Missing  distribution for  for the scalar mediator of 200 GeV. The  distributions are shown for two cuts on the transverse momentum of the jet
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4581402&req=5

Fig19: Missing distribution for for the scalar mediator of 200 GeV. The distributions are shown for two cuts on the transverse momentum of the jet
Mentions: For this kind of process, it is important to investigate the importance of additional QCD radiation, similarly to what we observe in the SM for [25]. We illustrate this effect in Fig. 19 by showing in the ‘resonant’ case (200 GeV scalar mediator) the missing transverse momentum for the zero and one-jet multiplicities. We see that these contributions are not suppressed compared to the 0-jet ones. In the SM this effect, i.e. the importance of the 1-jet contribution, is even more pronounced at high as the 0-jet amplitude is extremely suppressed by the cancellation between box and triangle diagrams. In any case, it might be important experimentally to perform inclusive searches rather than applying a jet veto, as such a cut will eliminate these enhanced 1-jet contributions. A more accurate prediction of the shapes can be provided by LO merging and matching to the PS, a procedure that is automatic in MG5aMC.

Bottom Line: We show how studies relevant for mono-X searches at the LHC in simplified models featuring a dark-matter candidate and an s-channel mediator can be performed within the MadGraph5_aMC@NLO framework.We focus on gluon-initiated loop-induced processes, mostly relevant to the case where the mediator couples preferentially to third generation quarks and in particular to the top quark.Our implementation allows us to study signatures at hadron colliders involving missing transverse energy plus jets or plus neutral bosons ([Formula: see text]), possibly including the effects of extra radiation by multi-parton merging and matching to the parton shower.

View Article: PubMed Central - PubMed

Affiliation: Institute for Particle Physics Phenomenology (IPPP), Durham University, Durham, DH1 3LF UK.

ABSTRACT

We show how studies relevant for mono-X searches at the LHC in simplified models featuring a dark-matter candidate and an s-channel mediator can be performed within the MadGraph5_aMC@NLO framework. We focus on gluon-initiated loop-induced processes, mostly relevant to the case where the mediator couples preferentially to third generation quarks and in particular to the top quark. Our implementation allows us to study signatures at hadron colliders involving missing transverse energy plus jets or plus neutral bosons ([Formula: see text]), possibly including the effects of extra radiation by multi-parton merging and matching to the parton shower.

No MeSH data available.


Related in: MedlinePlus