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Measurement of the Neutron Electromagnetic Form Factor with Large Acceptance at High Rates

ORAL

Abstract

The neutron electromagnetic form factors, GEn and GMn, give important insights into the neutron structure. In previous experiments the proton electromagnetic form factors, GEp, was measured up to Q2 = 8.5 GeV2, and GMp was measured up to Q2 = 30 GeV2, while GEn has only been measured up to Q2 = 3.4 GeV2. The Super BigBite Spectrometer (SBS) program at JLab will measure the neutron form factor ratio, GEn/GMn, at Q2 values of 2.9, 6.6, and 9.7 GeV2 by scattering a polarized electron beam with a polarized 3He target, used here as an effective polarized neutron target, and measuring the double spin asymmetry of the cross section. Measurements of Q2 = 2.9 and 6.6 GeV2 was completed in December 2022, and Q2 = 9.7 GeV2 will be complete in October 2023. The analysis of this data is especially challenging due to the unprecedented high-rate background environment caused by the open nature of the spectrometer with a direct line of sight from tracking detectors to the target. Early analysis details for cuts and corrections needed for GEn extraction under these high-rate conditions at all Q2 points will be presented.

Presenters

  • Sean Jeffas

    University of Virginia

Authors

  • Sean Jeffas

    University of Virginia

  • Nilanga Liyanage

    University of Virginia, Univ of Virginia

  • Gordon D Cates

    Univ of Virginia

  • Bogdan Wojtsekhowski

    Jefferson Lab/Jefferson Science Associat, University of Virginia

  • Todd D Averett

    William & Mary

  • Andrew J Puckett

    University of Connecticut