Search for new physics in final states with an energetic jet or a hadronically decaying W or Z boson and transverse momentum imbalance at s

Abstract

A search for new physics using events containing an imbalance in transverse momentum and one or more energetic jets arising from initial-state radiation or the hadronic decay of W or Z bosons is presented. A data sample of proton-proton collisions at ffiffi ffi s p ¼ 13 TeV, collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 35.9 fb −1 , is used. The observed data are found to be in agreement with the expectation from standard model processes. The results are interpreted as limits on the dark matter production cross section in simplified models with vector, axial-vector, scalar, and pseudoscalar mediators. Interpretations in the context of fermion portal and nonthermal dark matter models are also provided. In addition, the results are interpreted in terms of invisible decays of the Higgs boson and set stringent limits on the fundamental Planck scale in the Arkani-Hamed, Dimopoulos, and Dvali model with large extra spatial dimensions.

Strongly interacting dark sectors in the early Universe and at the LHC through a simplified portal

“…Ordinary "mono-jet" searches (i.e. searches for energetic jets in association with missing energy) will reject such events because of prohibitive QCD backgrounds from misreconstructed jets [55,56]. Traditional searches for di-jet resonances are also expected to be insensitive to these kinds of events, since the visible jets only carry a fraction of the energy of the dark shower and hence their invariant mass does not peak at the mass of the Z .…”

Dark matter capture in celestial objects: improved treatment of multiple scattering and updated constraints from white dwarfs

“…The very same vaunted testability of WIMPs has however led to some degree of disappointment at not having seen a positive signal yet. Searches using the Large Hadron Collider (LHC) haven't found any trace of new physics up to the TeV scale [3,4]. As a result, the parent theories now appear to be less well-motivated.…”

Multilepton dark matter signals

“…This framework has been much explored in the literature, but usually in the context of 'simplified dark matter models', where only the dark matter particle plus the mediator, Z ′ , are considered. This leads to very characteristic signals already searched for at the LHC, such as mono-Higgs [42,43], mono-top [44,45], mono-Z/W [46][47][48] and mono-jet [48,49] production. The common feature of these signals is the production of a SM particle together with large missing energy resulting from the undetected dark matter particle.…”