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Title: AN EXPERIMENTAL STUDY OF THE DIRECT PRODUCTION OF PI MESONS BY HIGH-ENERGY ELECTRONS

Abstract

The direct production of pi mesons by high-energy electrons was studied experimentally as an indirect measurement of the charge and magnetic structure of the neutron. The reactions of interest are: e/sup -/ + p/sup +/ yields e/sup -/ + p/sup ~+/ + i/sup 0/ and e/sup -/ + p/sup +/ yields e/sup -/ + n/sup 0/ + pi /sup +/. Only the final electro n is observed. Physically the experiment consists of passing a beam of electrons through a liquid hydrogen target. Electrons scattered at a given angle and having momenta within a certain range about a selected value are analyzed with a magnetic spectrometer and counted by virtue of their Cerenkov light in a counter filled with paraffin oil. This counter has been designed to minimize the background. Counting rates for positive and negative particles are recorded for each momentum setting. The initial and final energies may be programmed to vary either the pionnucleon dynamics or the invariant four-momentum transfer (q/sup 2/) independently. The behavior of the cross section as a function of the latter variable is in part determined by charge and magnetic moment distributions of the proton and neutron and by the charge distribution of the pion.more » It is unfortunate that the sensitivity of the present experiment to the pion size is rather low, as no published information exists on this quantity. One important difference between electroproduction and the more usual gamma-ray excitation of mesons is the possibility of inducing the above reactions with the electric field possessed by the electron along its direction of motion. A simple proof was found of a theorem which permits a purely experimental determination of the amount of this longitudinal interaction relative to the transverse interaction occurring in both the electron and gamma-ray production of pions. This theorem is applicable to a wide class of electron scattering experiments. The results indicate the absence of any longitudinal pion production in the energy region covered by this experiment. This work represents a continuation and extension of two previous experiments done at Stanford. An unsuccessful search was made at high energies for effects of the socalled second resonance'' in the pion-nucleon interaction. Several experimental checks were raade on the validity of from deuteriura.« less

Authors:
Publication Date:
Research Org.:
Stanford Univ., Calif.
OSTI Identifier:
4805220
NSA Number:
NSA-16-024707
Resource Type:
Journal Article
Resource Relation:
Journal Name: Dissertation Abstr.; Journal Volume: Vol: 22; Other Information: Orig. Receipt Date: 31-DEC-62
Country of Publication:
Country unknown/Code not available
Language:
English
Subject:
PHYSICS; CHERENKOV COUNTERS; CROSS SECTIONS; DIGITAL SYSTEMS; DISTRIBUTION; ELECTRIC CHARGES; ELECTRONS; EXCITATION; GAMMA RADIATION; HYDROGEN; INTERACTIONS; LIQUIDS; MAGNETIC FIELDS; MAGNETIC MOMENTS; MEASURED VALUES; MOMENTUM; NEUTRONS; NUMERICALS; PARTICLE MODELS; PHASE SHIFT; PIONS; PRODUCTION; PROTONS; SCATTERING; SPECTROMETERS; TARGETS; VARIATIONS

Citation Formats

Hand, L.N. AN EXPERIMENTAL STUDY OF THE DIRECT PRODUCTION OF PI MESONS BY HIGH-ENERGY ELECTRONS. Country unknown/Code not available: N. p., 1962. Web.
Hand, L.N. AN EXPERIMENTAL STUDY OF THE DIRECT PRODUCTION OF PI MESONS BY HIGH-ENERGY ELECTRONS. Country unknown/Code not available.
Hand, L.N. Sun . "AN EXPERIMENTAL STUDY OF THE DIRECT PRODUCTION OF PI MESONS BY HIGH-ENERGY ELECTRONS". Country unknown/Code not available.
@article{osti_4805220,
title = {AN EXPERIMENTAL STUDY OF THE DIRECT PRODUCTION OF PI MESONS BY HIGH-ENERGY ELECTRONS},
author = {Hand, L.N.},
abstractNote = {The direct production of pi mesons by high-energy electrons was studied experimentally as an indirect measurement of the charge and magnetic structure of the neutron. The reactions of interest are: e/sup -/ + p/sup +/ yields e/sup -/ + p/sup ~+/ + i/sup 0/ and e/sup -/ + p/sup +/ yields e/sup -/ + n/sup 0/ + pi /sup +/. Only the final electro n is observed. Physically the experiment consists of passing a beam of electrons through a liquid hydrogen target. Electrons scattered at a given angle and having momenta within a certain range about a selected value are analyzed with a magnetic spectrometer and counted by virtue of their Cerenkov light in a counter filled with paraffin oil. This counter has been designed to minimize the background. Counting rates for positive and negative particles are recorded for each momentum setting. The initial and final energies may be programmed to vary either the pionnucleon dynamics or the invariant four-momentum transfer (q/sup 2/) independently. The behavior of the cross section as a function of the latter variable is in part determined by charge and magnetic moment distributions of the proton and neutron and by the charge distribution of the pion. It is unfortunate that the sensitivity of the present experiment to the pion size is rather low, as no published information exists on this quantity. One important difference between electroproduction and the more usual gamma-ray excitation of mesons is the possibility of inducing the above reactions with the electric field possessed by the electron along its direction of motion. A simple proof was found of a theorem which permits a purely experimental determination of the amount of this longitudinal interaction relative to the transverse interaction occurring in both the electron and gamma-ray production of pions. This theorem is applicable to a wide class of electron scattering experiments. The results indicate the absence of any longitudinal pion production in the energy region covered by this experiment. This work represents a continuation and extension of two previous experiments done at Stanford. An unsuccessful search was made at high energies for effects of the socalled second resonance'' in the pion-nucleon interaction. Several experimental checks were raade on the validity of from deuteriura.},
doi = {},
journal = {Dissertation Abstr.},
number = ,
volume = Vol: 22,
place = {Country unknown/Code not available},
year = {Sun Apr 01 00:00:00 EST 1962},
month = {Sun Apr 01 00:00:00 EST 1962}
}