| Literature DB >> 36093314 |
Cesare Cazzaniga1, Annapaola de Cosa1.
Abstract
This Letter proposes a new search for confining dark sectors at the Large Hadron Collider. As a result of the strong dynamics in the hidden sector, dark matter could manifest in proton-proton collisions at the Large Hadron Collider in form of hadronic jets containing stable invisible bound states. These semi-visible jets have been studied theoretically and experimentally in the fully hadronic signature where the unstable composite dark matter can only decay promptly back to Standard Model quarks. We present a simplified model based on two messenger fields separated by a large mass gap allowing dark bound states to decay into pairs of oppositely charged leptons. The resulting experimental signature is characterized by non-isolated lepton pairs inside semi-visible jets. We propose a search strategy independent from the underlying model assumptions targeting this new signature, and discuss the orthogonality with respect to the existing searches. Remaining agnostic on the shape of the di-lepton spectrum, we determine the sensitivity of a dedicated analysis to the target signal. The proposed search can claim the 3 σ evidence (exclusion) of the heavier mediator up to masses of 3.5 TeV (4.5 TeV) with the full Run 2 data of the LHC. Exploiting the resonant feature of the lepton pairs can enhance the sensitivity reach on a specific model. We estimate that an analysis using the di-lepton invariant mass information can reach 5 σ discovery up to masses of 3.5 TeV and improve the exclusion up to more than 5 TeV.Entities:
Year: 2022 PMID: 36093314 PMCID: PMC9448692 DOI: 10.1140/epjc/s10052-022-10775-2
Source DB: PubMed Journal: Eur Phys J C Part Fields ISSN: 1434-6044 Impact factor: 4.991
Fig. 1S-channel production of semi-visible jets with non-isolated prompt leptons produced from dark hadrons decays
Signal model parameterization
| Parameter | Description | Benchmark |
|---|---|---|
| 1.5–5 TeV | ||
| Effective mixing | 0.03 | |
| Invisible fraction | 0.3, 0.5, 0.7 | |
| Dark confinement scale | 5 GeV | |
| Pseudo-scalar mass ratio | 1.6 |
Fig. 2a Multiplicity of mini-isolated muons. b Distribution of muons inter-isolation for . c Multiplicity of non inter-isolated muons. In all the histograms the last bin represents the overflow. The signal distributions are referred to a benchmark mass point TeV and , while all the other parameters are fixed as in Table 1
Fig. 3a template for the signal (benchmark mass point TeV and ) and background processes after applying the selections proposed in this Letter (without the requirement on ). The binning has been chosen according to an experimental resolution . b Expected limits on for the signal benchmark with and all the other parameters fixed as in Table 1. The fully hadronic SVJ analysis expected exclusion reach (dashed blue line) for the SVJ signature is compared with the proposed SVJ cut based analysis without exploiting the selection on (dashed gray line)