A polarized look at nucleons: Laser electron gamma source

Conference · Tue Jan 01 04:00:00 EST 1991

OSTI ID:7048494

As the title suggests we are going to look at reactions induced on nucleons by polarized photons. The results I am going to show today are from the Laser Electron Gamma Source, or LEGS'' facility, at Brookhaven National Laboratory. At LEGS, gamma ray beams are produced by backscattering laser light from relativistic electrons. I will only summarize the main characteristics of this facility, and leave an in depth description to Dr. Schaerf who will discuss LEGS and other similar backscattering facilities on Wednesday. Reactions with polarized photons inevitably reflect interference terms that for the most part remain hidden in spin-averaged unpolarized measurements. This provides a tool for probing interactions that depend upon spin. In particular, we are going to look today at two cases where the polarization is used to probe the tensor interaction. First, we will examine the tensor force between a proton-neutron pair in deuterium. Secondly, we will examine the tensor force between quarks in a proton that produces a small E2 component that is mixed with the predominantly M1 excitation of the delta resonance.The magnitude of this E2 components provides a sensitive probe of the structure of the Nucleon.

• Research Organization: Brookhaven National Lab., Upton, NY (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 7048494
• Report Number(s): BNL-47729; CONF-9112101--2; ON: DE92018119
• Country of Publication: United States
• Language: English

Related Subjects

662340* -- Hadron Interactions-- (1992-)
662410 -- Properties of Baryons & Baryon Resonances-- (1992-)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYON-BARYON INTERACTIONS
BARYONS
BASIC INTERACTIONS
BEAMS
CROSS SECTIONS
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
FERMIONS
GAMMA SOURCES
HADRON-HADRON INTERACTIONS
HADRONS
INTERACTIONS
LASERS
NUCLEON-NUCLEON INTERACTIONS
NUCLEONS
PARTICLE INTERACTIONS
PARTICLE STRUCTURE
PHOTON-BARYON INTERACTIONS
PHOTON-HADRON INTERACTIONS
PHOTON-NUCLEON INTERACTIONS
POLARIZED BEAMS
POSTULATED PARTICLES
QUARKS
RADIATION SOURCES
TENSOR FORCES