Searching for an Invisible A' Vector Boson with DarkLight

High-luminosity experiments are able to search for new physics at low energies, which could have evaded detection thus far due to very weak couplings to the Standard Model. The DarkLight experiment at Jefferson Lab is designed to search for a new U(1) vector boson A′ in the mass range 10–100 MeV thr...

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Bibliographic Details
Main Authors: Kahn, Yonatan Frederick, Thaler, Jesse
Other Authors: Massachusetts Institute of Technology. Center for Theoretical Physics
Format: Article
Language:en_US
Published: American Physical Society 2013
Online Access:http://hdl.handle.net/1721.1/76697
https://orcid.org/0000-0002-9379-1838
https://orcid.org/0000-0002-2406-8160
Description
Summary:High-luminosity experiments are able to search for new physics at low energies, which could have evaded detection thus far due to very weak couplings to the Standard Model. The DarkLight experiment at Jefferson Lab is designed to search for a new U(1) vector boson A′ in the mass range 10–100 MeV through its decay A′→e[superscript +]e[superscript -]. In this paper, we demonstrate that DarkLight is also sensitive to an A′ decaying to invisible final states. We analyze the DarkLight reach for invisible A′ bosons assuming a nominal two month running time, including the possibility of augmenting the DarkLight design to include photon detection. We also propose two new analysis techniques that might prove useful for other high-luminosity searches: a cut on missing energy to improve the invariant mass resolution, and a cut on the sign of the missing invariant mass-squared to mitigate pileup. We compare the DarkLight reach to existing experimental proposals, including a complementary search using the VEPP-3 positron beam.