Search for anomalous production of multiple leptons in association with W and Z bosons at CDF

Abstract

This paper presents a search for anomalous production of multiple low-energy leptons in association with a W or Z boson using events collected at the CDF experiment corresponding to 5.1 fb −1 of integrated luminosity. This search is sensitive to a wide range of topologies with low-momentum leptons, including those with the leptons near one another. The observed rates of production of additional electrons and muons are compared with the standard model predictions. No indications of phenomena beyond the standard model are found. A 95% confidence level limit is presented on the production cross section for a benchmark model of supersymmetric hidden-valley Higgs production. Particle identification efficiencies are also provided to enable the calculation of limits on additional models.

Exotic Decays of the 125 GeV Higgs Boson

“…Another interesting possibility would give several such dark photons created with low momentum along with E / T , leading to many unclustered very soft leptons. An attempt to search for such final states was made by CDF [226]. Unfortunately, in models where the vector bosons can decay also to pions, the leptons are fewer and hadrons often take their place, making the challenges much greater.…”

“…Searches in electron-jets are more challenging, as backgrounds from QCD jets with a large electromagnetic fraction are significant, and as identifying collimated electrons from BSM physics is complicated by photon conversions. Nonetheless, searches for h → 2 electronjets have been carried out, targeting W h associated production first at CDF with 5.1 fb −1 data [226] and later at ATLAS with 2.04 fb −1 of 7 TeV data [225] and inclusively for pairs [337]. Here solid lines indicate m χ 2 = 50 GeV and dotted lines m χ 2 = 60 GeV, while red, green, and blue correspond to m a,Z D = 3 GeV, 1 GeV, and 0.4 GeV respectively.…”

“…• h to > 4 leptons, τ s, bs; decays such as h → 6τ or 8b have been suggested in the literature [262], see also §1.3.5, §1.3.10, but both theoretical and experimental study has been limited, though CDF has looked for decays of the Higgs to many soft leptons [226].…”

Review of Physics Results from the Tevatron: Higgs Boson Physics

“…The CDF Collaboration has also performed a generic search for anomalous production of multiple leptons produced in association with W and Z bosons using 5.1 fb −1 of Run II data. 180 This search is sensitive to a wide range of scenarios that predict multiple electrons and muons, including clusters of leptons that are produced spatially close to each other, often referred to as "lepton-jets". [181][182][183] No significant excess is observed above the SM background expectation and a 95% C.L.…”