14 research outputs found

    Theory, phenomenology, and experimental avenues for dark showers: a Snowmass 2021 report

    Full text link
    In this work, we consider the case of a strongly coupled dark/hidden sector, which extends the Standard Model (SM) by adding an additional non-Abelian gauge group. These extensions generally contain matter fields, much like the SM quarks, and gauge fields similar to the SM gluons. We focus on the exploration of such sectors where the dark particles are produced at the LHC through a portal and undergo rapid hadronization within the dark sector before decaying back, at least in part and potentially with sizeable lifetimes, to SM particles, giving a range of possibly spectacular signatures such as emerging or semi-visible jets. Other, non-QCD-like scenarios leading to soft unclustered energy patterns or glueballs are also discussed. After a review of the theory, existing benchmarks and constraints, this work addresses how to build consistent benchmarks from the underlying physical parameters and present new developments for the PYTHIA Hidden Valley module, along with jet substructure studies. Finally, a series of improved search strategies is presented in order to pave the way for a better exploration of the dark showers at the LHC.Comment: Uniform notation, fixed typos, improved numerical analysis, added references, comments welcom

    Search for new Higgs bosons via same-sign top quark pair production in association with a jet in proton-proton collisions at s\sqrt{s} = 13 TeV

    No full text
    International audienceA search is presented for new Higgs bosons in proton-proton (pp) collision events in which a same-sign top quark pair is produced in association with a jet, via the pp ‚Üí\to tH/A ‚Üí\to ttňČ\mathrm{\bar{t}}c and pp ‚Üí\to tH/A ‚Üí\to ttňČ\mathrm{\bar{t}}u processes. Here, H and A represent the extra scalar and pseudoscalar boson, respectively, of the second Higgs doublet in the generalized two-Higgs-doublet model (g2HDM). The search is based on pp collision data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 138 fb‚ąí1^{-1}. Final states with a same-sign lepton pair in association with jets and missing transverse momentum are considered. New Higgs bosons in the 200-1000 GeV mass range and new Yukawa couplings between 0.1 and 1.0 are targeted in the search, for scenarios in which either H or A appear alone, or in which they coexist and interfere. No significant excess above the standard model prediction is observed. Exclusion limits are derived in the context of the g2HDM

    Search for new Higgs bosons via same-sign top quark pair production in association with a jet in proton-proton collisions at s\sqrt{s} = 13 TeV