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Title: An electron fixed target experiment to search for a new vector boson A' decaying to e+e-

We describe an experiment to search for a new vector boson A' with weak coupling alpha' > 6 x 10–8 α to electrons (α' = e2/4π) in the mass range 65 MeV < mA' < 550 MeV. New vector bosons with such small couplings arise naturally from a small kinetic mixing of the "dark photon" A' with the photon -- one of the very few ways in which new forces can couple to the Standard Model -- and have received considerable attention as an explanation of various dark matter related anomalies. A' bosons are produced by radiation off an electron beam, and could appear as narrow resonances with small production cross-section in the trident e+e- spectrum. We summarize the experimental approach described in a proposal submitted to Jefferson Laboratory's PAC35, PR-10-009. This experiment, the A' Experiment (APEX), uses the electron beam of the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory (CEBAF) at energies of ~1-4 GeV incident on 0.5-10% radiation length Tungsten wire mesh targets, and measures the resulting e+e- pairs to search for the A' using the High Resolution Spectrometer and the septum magnet in Hall A. With a ~1 month run, APEX will achieve very good sensitivitymore » because the statistics of e+e- pairs will be ~10,000 times larger in the explored mass range than any previous search for the A' boson. These statistics and the excellent mass resolution of the spectrometers allow sensitivity to α'/α one to three orders of magnitude below current limits, in a region of parameter space of great theoretical and phenomenological interest. Similar experiments could also be performed at other facilities, such as the Mainz Microtron.« less
Authors:
;  [1] ;  [1] ;  [2]
  1. Perimeter Institute for Theoretical Physics, Waterloo, ON (Canada)
  2. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
Publication Date:
OSTI Identifier:
1023010
Report Number(s):
JLAB-PHY--10-1124; DOE/OR/23177--1121; arXiv:1001.2557; SLAC-PUB--13882; SU-ITP--10-01
Journal ID: ISSN 1029-8479; TRN: US1104441
Grant/Contract Number:
AC05-06OR23177; AC02-76SFO0515
Type:
Accepted Manuscript
Journal Name:
Journal of High Energy Physics (Online)
Additional Journal Information:
Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2011; Journal Issue: 2; Journal ID: ISSN 1029-8479
Publisher:
Springer Berlin
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ACCELERATORS; BOSONS; CEBAF ACCELERATOR; ELECTRON BEAMS; ELECTRONS; KINETICS; MASS RESOLUTION; NONLUMINOUS MATTER; PHOTONS; RADIATION LENGTH; RADIATIONS; RESOLUTION; SENSITIVITY; SEPTUM MAGNETS; SPECTROMETERS; STANDARD MODEL; STATISTICS; TARGETS; TUNGSTEN; VECTORS Beyond Standard Model; electromagnetic processes and properties