A simple relation between the gamma N -> N(1535) helicity amplitudes

Abstract

It is shown that the helicity amplitudes A_1/2 and S_1/2 in the gamma N -> N(1535) reaction, can be well related by S_1/2 = -\frac{\sqrt{1+τ}}{\sqrt{2}} \frac{M_S^2-M^2}{2 M_S Q} A_1/2 in the region Q^2 > 2 GeV^2, where M and M_S are the nucleon and N(1535) masses, q^2=-Q^2 the four-momentum transfer squared, and tau=\sfrac{Q^2}{(M_S+M)^2}. The observed relation is tested by the experimental data and the MAID parametrization. A direct consequence of the relation is that the assumption,|A_1/2| >> |S_1/2|, is not valid for high Q^2. Instead, both amplitudes A_1/2 and S_1/2 have the same Q^2 dependence in the high Q^2 region, aside from that S_{1/2} has an extra factor,-\sfrac{1}{\sqrt{2}}\sfrac{M_S-M}{2M_S}. The origin of this relation is interpreted in a perspective of a quark model.

Version accepted for publication in Phys.Rev.D. 4 pages, 3 figures

References in corpus (8)

• Unitary Isobar Model - MAID2007
• Nucleon Electromagnetic Form Factors
• A pure S-wave covariant model for the nucleon
• D-state effects in the electromagnetic N-Delta transition
• Dynamical coupled-channels analysis of 1H(e,e'pi)N reactions
• Transition form factors of the N*(1535) as a dynamically generated resonance
• A covariant model for the gamma N -> N(1535) transition at high momentum transfer
• Electroproduction of the N*(1535) resonance at large momentum transfer

Cited by in corpus (28)

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• Valence quark and meson cloud contributions for the gamma* Lambda -> Lambda* and gamma* Sigma0 -> Lambda* reactions
• Valence quark and meson cloud contributions to the ${\gamma }^{\ast }N\to N^{\ast }(1520)$ form factors
• Nucleon resonances in Compton scattering
• Axial form factors of the octet baryons in a covariant quark model
• 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
• Nucleon resonances with higher spins in soft-wall AdS/QCD
• ${\gamma }^{\ast }N\to N(1710)$ transition at high momentum transfer
• Semirelativistic approximation to the ${\gamma }^{\ast }N\to N(1520)$ and ${\gamma }^{\ast }N\to N(1535)$ transition form factors
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• Improved empirical parametrizations of the ${\gamma }^{\ast }N\to N(1535)$ transition amplitudes and the Siegert's theorem
• Covariant model for the Dalitz decay of the $N(1535)$ resonance
• $\gamma N\to N^{\ast }(1535)$ transition in soft-wall AdS/QCD
• Electromagnetic form factors of octet baryons in QCD
• Low-$Q^2$ empirical parametrizations of the $N^{\ast }$ helicity amplitudes
• Electroweak form factors of baryons in dense nuclear matter
• Octet negative parity to octet positive parity electromagnetic transitions in light cone QCD
• Odd-Parity Nucleon Electromagnetic Transitions in Lattice QCD
• Quark model calculations of transition form factors at high photon virtualities
• A covariant model for the negative parity resonances of the nucleon
• A Relativistic Model for the Electromagnetic Structure of Baryons from the 3rd Resonance Region
• Hadronic few-body systems in chiral dynamics, -- Few-body systems in hadron physics --
• N*(1535) electroproduction at high Q2