Semirelativistic approximation to the ${\gamma }^{\ast }N\to N(1520)$ and ${\gamma }^{\ast }N\to N(1535)$ transition form factors

Abstract

The representation of the wave functions of the nucleon resonances within a relativistic framework is a complex task. In a nonrelativistic framework the orthogonality between states can be imposed naturally. In a relativistic generalization, however, the derivation of the orthogonality condition between states can be problematic, particularly when the states have different masses. In this work we study the $N(1520)$ and $N(1535)$ states using a relativistic framework. We considered wave functions derived in previous works, but impose the orthogonality between the nucleon and resonance states using the properties of the nucleon, ignoring the difference of masses between the states (semirelativistic approximation). The $N(1520)$ and $N(1535)$ wave functions are then defined without any adjustable parameters and are used to make predictions for the valence quark contributions to the transition form factors. The predictions compare well with the data particularly for high momentum transfer, where the dominance of the quark degrees of freedom is expected.

5 figures, 14 pages. Published version

References in corpus (20)

• Unitary Isobar Model - MAID2007
• A study of the $P_{11}(1440)$ and $D_{13}(1520)$ resonances from CLAS data on $ep\to e^{\prime }{\pi }^{+}{\pi }^{-}{p}^{\prime }$
• A pure S-wave covariant model for the nucleon
• A systematic study of longitudinal and transverse helicity amplidutes in the hypercentral Constituent Quark Model
• D-state effects in the electromagnetic N-Delta transition
• A Covariant model for the nucleon and the $\Delta$
• A relativistic quark model for the Omega- electromagnetic form factors
• Electroexcitation of the Roper resonance in the relativistic quark models
• Octet baryon electromagnetic form factors in nuclear medium
• Dynamical coupled-channels analysis of 1H(e,e'pi)N reactions
• Transition form factors of the N*(1535) as a dynamically generated resonance
• Timelike gamma* N -> Delta form factors and Delta Dalitz decay
• Valence quark and meson cloud contributions for the gamma* Lambda -> Lambda* and gamma* Sigma0 -> Lambda* reactions
• Extracting the Omega- electric quadrupole moment from lattice QCD data
• Fixed-axis polarization states: covariance and comparisons
• ${\gamma }^{\ast }N\to N^{\ast }(1520)$ form factors in the timelike regime
• Covariant spectator quark model description of the ${\gamma }^{\ast }\Lambda \to {\Sigma }^0$ transition
• Using the Single Quark Transition Model to predict nucleon resonance amplitudes
• The shape of the $\Delta$ baryon in a covariant spectator quark model
• ${\gamma }^{\ast }N\to N(1710)$ transition at high momentum transfer

Cited by in corpus (11)

• Electromagnetic Transition Form Factors of Baryon Resonances
• Nucleon resonances with higher spins in soft-wall AdS/QCD
• Transition form factors and helicity amplitudes for electroexcitation of negative- and positive parity nucleon resonances in a light-front quark model
• Electromagnetic form factors of the ${\Omega }^{-}$ baryon in the spacelike and timelike regions
• Covariant model for the Dalitz decay of the $N(1535)$ resonance
• $\gamma N\to N^{\ast }(1535)$ transition in soft-wall AdS/QCD
• A covariant model for the decuplet to octet Dalitz decays
• Weak interaction axial form factors of the octet baryons in nuclear medium
• Meson cloud contributions to the Dalitz decays of decuplet to octet baryons
• Electroweak form factors of baryons in dense nuclear matter
• About the magnitude of the ${\gamma }^{\ast }N\to N(1520)$ transverse amplitudes near $Q^2=0$