Abstract
Electron positron collisions are a very promising environment to search for new physics, and in particular for dark sector related observables. The most challenging experimental problem in detecting dark sector candidates is the very high associated Standard Model background. For this reason it is important to identify observables that are, at the same time, minimally suppressed in the dark sector and highly suppressed in the Standard Model. One example is the e+e− → 3(e+e−) process that can be mediated either by the production and subsequent decay of dark Higgs (h′), e+e− → A′h′ → 6e [1] or produced by the Standards Model process e+e− → 3(e+e−). In the following letter we study the relative contribution to observed e+e− → 3(e+e−) total cross section, coming from the h′ mediated and from the Standard Model processes in the contest of fixed target and low energy collider experiments, with particular attention to the PADME experiment at the INFN Laboratori Nazionali di Frascati.
Highlights
Background suppression we would like to point out that appropriate experimental cuts on the final e+e− → 3(e+e−) state can strongly enhance the S/B ratio
In the following letter we study the relative contribution to observed e+e− → 3(e+e−) total cross section, coming from the h mediated and from the Standard Model processes in the contest of fixed target and low energy collider experiments, with particular attention to the PADME experiment at the INFN Laboratori Nazionali di Frascati
As shown in the previous paragraph the precision of the leading log Equivalent Photon Approximation (EPA) approximation in predicting the value of the σe+e−→e+e−e+e− is poor, in particular at energies below the GeV. For this reason we developed an alternative approach which allows to maintain better precision, without performing a full tree level calculation as we did with CalcHEP
Summary
The authors of [1] consider a minimal extension of the SM by adding to the SM a U(1)D gauge boson A and a single complex scalar Higgs’ field φ responsible for spontaneous symmetry breaking. They assume that any additional particles, in particular possible dark matter candidates, are heavy compared to the A and h mass scales. For masses mh < 2mA decays to off-shell A are possible but, due to the suppression of the 4 body decay h → A ∗ A ∗ → 2(e+e−), the dominant decay proceeds through triangle graphs to an e+e− pair [1] The lifetime in this case is extremely long and the Dark Higgs will be stable on the experiment scale producing missing energy in the final state. Under the muon production threshold the possible dark sector final states induced by h produced in association with an A are either 3(e+e−) or (e+e−) + missing energy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
