GEp/GMp Ratio by Polarization Transfer in \vec{e}p→e\vec{p}

• The ratio of the proton's elastic electromagnetic form factors, GEp/GMp, was obtained by measuring Pt and Pℓ, the transverse and the longitudinal recoil proton polarization, respectively. For elastic →ep→e→p, GEp/GMp is proportional to Pt/Pℓ. Simultaneous measurement of Pt and Pℓ in a polarimeter provides good control of the systematic uncertainty. The results for the ratio GEp/GMp show a systematic decrease as Q2 increases from 0.5 to 3.5GeV2, indicating for the first time a definite difference in the spatial distribution of charge and magnetization currents in the proton.

Subject headings

NATURVETENSKAP  -- Fysik -- Acceleratorfysik och instrumentering (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Accelerator Physics and Instrumentation (hsv//eng)

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art (subject category)

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