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Register a new userNeutron charge form factor and quadrupole deformation of the nucleon
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Authors
A.J. Buchmann
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A quark model relation between the neutron charge form factor and the N->Delta charge quadrupole form factor is used to predict the C2/M1 ratio in the N->Delta transition from the elastic neutron form factor data. Excellent agreement with the electro-pionproduction data is found, indicating the validity of the suggested relation. The implication of the negative C2/M1 ratio for the intrinsic deformation of the nucleon is discussed.
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To obtain further information on the geometric shape of the nucleon, the proton charge form factor is decomposed into two terms, which are connected respectively with a spherically symmetric and an intrinsic quadrupole part of the protons charge density. Quark model relations are employed to derive expressions for both terms. In particular, the protons intrinsic quadrupole form factor is obtained from a relation between the N -> Delta and neutron charge form factors. The proposed decomposition shows that the neutron charge form factor is an observable manifestation of an intrinsic quadrupole form factor of the nucleon. Furthermore, it affords an interpretation of recent electron-nucleon scattering data in terms of a nonspherical distribution of quark-antiquark pairs in the nucleon.
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