Addressing the multi-channel inverse problem at high energy colliders: a model-independent approach to the search for new physics with trileptons

Abstract

We describe a method for interpreting trilepton searches at high energy colliders in a model-independent fashion and apply it to the recent searches at the Tevatron. The key step is to recognize that the trilepton signature is comprised of four experimentally very different channels defined by the number of τ leptons in the trilepton state. Contributions from these multiple channels to the overall experimental sensitivity (cross section times branching ratio) are model-independent and can be parametrized in terms of relevant new particle masses. Given the trileptonic branching ratios of a specific model, these experimentally obtained multichannel sensitivities can be combined to obtain a cross section measurement that can be used to confront the model with data. Our model-independent results are more widely applicable than the current Tevatron trilepton results which are stated exclusively in terms of mSUGRA parameters of supersymmetry. The technique presented here can be expanded beyond trilepton searches to the more general "inverse problem" of experimentally discriminating between competing models that seek to explain new physics discovered in multiple channels.

The status of GMSB after 1/fb at the LHC

“…Simplified spectra are ideal for this, as they capture precisely the information experimentalists will actually use: physical masses, production rates, and branching ratios. In taking this approach, our outlook is similar to that of other recent work that advocates for studying new physics in terms of physical masses, rates, and branching ratios [27][28][29][30][31][50][51][52][53][54][55], and complementary to other work in progress [56].…”

The hunt for the rest of the Higgs bosons

“…Given the proliferation of potential signals, it is useful to consider signatures broadly. Interesting topologies and searches for new Higgs bosons can be classified in terms of simplified models, much in the spirit of simplified model searches for supersymmetry [10][11][12]. These simplified models may then be combined to provide coverage of the parameter space of a given extended Higgs sector.…”

Multi-lepton signals of multiple Higgs bosons

“…In this work, we have examined the reach of multi-lepton searches for probing the collective leptonic signatures resulting from the additional Higgs bosons in 2HDMs. In a study of 20 exclusive multi-lepton channels in four benchmark spectra with four discrete types of fermion couplings across 222 production and decay topologies, using a factorized mapping procedure [12] we determined regions of 2HDM parameter space probed by data from a recent CMS multilepton search [9] with 5 fb −1 of 7 TeV proton-proton collisions. These results provide new limits in some regions of 2HDM parameter space that have not been covered by other types of direct experimental investigations.…”

“…In order to assess the multi-lepton signatures of the 2HDMs studied here we employ a factorized mapping procedure [12] to go between model parameters and signatures. In this procedure the acceptance times efficiency is independently determined in each of the 20 exclusive multi-lepton channels by monte carlo simulation of each individual production and decay topology in each of the four 2HDM mass spectra as well as for the individual topologies of the Standard Model Higgs boson.…”

“…So instead we employ a factorized mapping procedure to go between model parameters and signatures [12]. In this procedure the acceptance times efficiency for each individual production and decay topology is independently determined from monte carlo simulation, assuming unit values for all branching ratios in the decay topology.…”