Collider constraints on dark mediators

Abstract

We explore the constraints current collider searches place on a QCD-like dark sector. A combination of multi-jet, multi-jet plus missing energy and emerging jets searches is used to derive constraints on the mediator mass across the full range of the dark meson lifetimes for the first time.The dark sector inherits a flavour structure from the coupling between the dark quarks and the SM quarks through the mediator. When this is taken into account, the differently flavoured dark pions become distinguishable through their lifetime. We show that also in these cases the above mentioned searches remain sensitive, and we obtain limits on the mediator mass also for the flavoured scenario.We then contrast the constraints from collider searches with direct detection bounds on the dark matter candidate itself in both the flavoured and unflavoured scenario. Using a simple prescription it becomes possible to display all constraints in the dark matter and mediator mass plane. Constraints from direct detection tend to be stronger than the collider constraints, unless the coupling to the first generation quarks is suppressed, in which case the collider searches place the most stringent limits on the parameter space.

Charming ALPs

“…Regardless of whether these collaborations publish limits directly on a two-body decay or a recast of the three-body decay analysis is needed, such numbers represent a great improvement with respect to current bounds. 6…”

“…Simple flavoured dark matter scenarios have received a lot of attention recently [1][2][3][4], since they allow probes of dark sector physics using low energy flavour observables. For strongly coupled dark sectors, a JHEP08(2021)121 flavoured portal imprints the Standard Model (SM) flavour structure on the dark sector, leading to a variety of new phenomena [5,6].…”

Exploring jet substructure in semi-visible jets

“…Studies discussed in [7,[10][11][12] have shown that the decay of dark hadrons also depends on the mediator to the visible sector. Two different dark quark flavours combine to form dark π + , π − , π 0 , and dark ρ + , ρ − , ρ 0 , where the dark ρ's are assumed to be produced thrice as much as pions.…”

Emerging Jets Displaced into the Future

“…The dark pion lifetime is of crucial importance in determining the type of signals these dark QCD models produce. Depending on the dark pion lifetime, there are three different final states that can be considered [48]: 1) the dark pions are long-lived (cτ π d 1 m) and appear as missing energy in the primary LHC detectors, 2) the dark pions have intermediate lifetimes (1 mm cτ π d 1 m) and produce Emerging Jets, and 3) the dark pions decay promptly (cτ π d 1 mm), producing 4 jets. For this work, the first scenario is our primary interest as it is the chunk of parameter space most easily explored by LLP detectors.…”

“…The EJ signature features clusters of LLPs produced in jet-like structures, and there has now been an experimental search for Emerging Jets at CMS [45]. There have also been phenomenological studies of the flavour effects in these models [46,47], a recast of different bounds [48], and a study of novel triggering strategies [49].…”