Covariant model for the Dalitz decay of the $N(1535)$ resonance

Abstract

We develop a covariant model for the ${\gamma }^{\ast }N\to N(1535)$ transition in the timelike kinematical region, the region where the square momentum transfer $q^2$ is positive. Our starting point is the covariant spectator quark model constrained by data in the spacelike kinematical region ($Q^2=-q^2>0$). The model is used to estimate the contributions of valence quarks to the transition form factors, and one obtains a fair description of the Dirac form factor at intermediate and large $Q^2$. For the Pauli form factor there is evidence that beyond the quark-core contributions there are also significant contributions of meson cloud effects. Combining the quark-core model with an effective description of the meson cloud effects, we derive a parametrization of the spacelike data that can be extended covariantly to the timelike region. This extension enabled us to estimate the Dalitz decay widths of the $N(1535)$ resonance, among other observables. Our calculations can help in the interpretation of the present experiments at HADES ($pp$ collisions and others).

arXiv comment23 pages, 17 figures

References in corpus (74)

• Unitary Isobar Model - MAID2007
• Electroexcitation of nucleon resonances from CLAS data on single pion electroproduction
• Studies of Nucleon Resonance Structure in Exclusive Meson Electroproduction
• Electromagnetic structure of the deuteron
• Electroexcitation of nucleon resonances
• Dressed-quark anomalous magnetic moments
• Electromagnetic Meson Production in the Nucleon Resonance Region
• Re-analysis of the nucleon space- and time-like electromagnetic form factors in a two-component model
• Origin of the low-mass electron pair excess in light nucleus-nucleus collisions
• Hamiltonian effective field theory study of the ${\mathbf{N}}^{\ast }(1535)$ resonance in lattice QCD
• A pure S-wave covariant model for the nucleon
• Structure of the nucleon from electromagnetic space-like and time-like form factors
• Dilepton production in proton-induced reactions at SIS energies with the GiBUU transport model
• Inclusive dielectron spectra in p+p collisions at 3.5 GeV
• Covariant equations for the three-body bound state
• 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
• Isospin decomposition of $\gamma N\to N^{\ast }$ transitions within a dynamical coupled-channels model
• The Anomalous Magnetic Moment of Quarks
• 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
• Valence quark contribution for the gamma N -> Delta quadrupole transition extracted from lattice QCD
• Valence quark contributions for the gamma N -> P11(1440) form factors
• First measurement of low momentum dielectrons radiated off cold nuclear matter
• Electromagnetic form factors of the Delta with D-waves
• Electromagnetic transition form factors and dilepton decay rates of nucleon resonances
• A covariant model for the gamma N -> N(1535) transition at high momentum transfer
• Timelike gamma* N -> Delta form factors and Delta Dalitz decay
• Electroproduction of Eta Mesons in the S11(1535) Resonance Region at High Momentum Transfer
• Octet baryon electromagnetic form factors in a relativistic quark model
• A model for the Delta(1600) resonance and gamma N -> Delta(1600) transition
• A versatile method for simulating pp -> ppe+e- and dp -> pne+e-p_spec reactions
• Electroproduction of the N*(1535) resonance at large momentum transfer
• Nucleon and gamma N -> Delta lattice form factors in a constituent quark model
• Approach to Perturbative Results in the N-Delta Transition
• Octet to decuplet electromagnetic transition in a relativistic quark model
• Baryon resonance production and dielectron decays in proton-proton collisions at 3.5 GeV
• Electroproduction of the $N^{\ast }(1535)$ nucleon resonance in QCD
• Rôle of the pion electromagnetic form factor in the $\Delta (1232)\to {\gamma }^{\ast }N$ timelike transition
• Hyperon electromagnetic timelike elastic form factors at large $q^2$
• Baryon Resonance Analysis from MAID
• Covariant nucleon wave function with S, D, and P-state components
• Using baryon octet magnetic moments and masses to fix the pion cloud contribution
• Valence quark and meson cloud contributions for the gamma* Lambda -> Lambda* and gamma* Sigma0 -> Lambda* reactions
• What is the role of the meson cloud in the ${\Sigma }^{\ast 0}\to \gamma \Lambda$ and ${\Sigma }^{\ast }\to \gamma \Sigma$ decays?
• A simple relation between the gamma N -> N(1535) helicity amplitudes
• Inclusive dielectron production in proton-proton collisions at 2.2 GeV beam energy
• Valence quark and meson cloud contributions to the ${\gamma }^{\ast }N\to N^{\ast }(1520)$ form factors
• Electromagnetic form factors of the Delta in a S-wave approach
• Axial form factors of the octet baryons in a covariant quark model
• Nucleon resonances in Compton scattering
• $\Delta$(1232) Dalitz decay in proton-proton collisions at T=1.25 GeV measured with HADES
• e^+e^- production from pp reactions at BEVALAC energies
• Study of exclusive one-pion and one-eta production using hadron and dielectron channels in pp reactions at kinetic beam energies of 1.25 GeV and 2.2 GeV with HADES
• Dilepton production in proton-proton collisions at BEVALAC energies
• ${\gamma }^{\ast }N\to N^{\ast }(1520)$ form factors in the timelike regime
• Spin and angular momentum in the nucleon
• 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
• Analysis of pion production data measured by HADES in proton-proton collisions at 1.25 GeV
• Electroexcitation of nucleon resonances of the [70,1-] multiplet in a light-front relativistic quark model
• Semirelativistic approximation to the ${\gamma }^{\ast }N\to N(1520)$ and ${\gamma }^{\ast }N\to N(1535)$ transition form factors
• ${\gamma }^{\ast }N\to N(1710)$ transition at high momentum transfer
• $N^{\ast }$ Form Factors based on a Covariant Quark Model
• Transition form factors and helicity amplitudes for electroexcitation of negative- and positive parity nucleon resonances in a light-front quark model
• Pole Term and Gauge Invariance in Deep Inelastic Scattering
• Improved empirical parametrizations of the ${\gamma }^{\ast }N\to N(1535)$ transition amplitudes and the Siegert's theorem
• Analysis of the exclusive final state npe${}^{+}$e${}^{-}$ in quasi-free np reaction
• $\gamma N\to N^{\ast }(1535)$ transition in soft-wall AdS/QCD
• Octet baryon electromagnetic form factor double ratios $(G_E^{\ast }/G_M^{\ast })/(G_E/G_M)$ in a nuclear medium
• Low-$Q^2$ empirical parametrizations of the $N^{\ast }$ helicity amplitudes
• Production of negative parity baryons in the holographic Sakai-Sugimoto model

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• Role of baryon resonances in the ${\pi }^{-}p\to n{e}^{+}{e}^{-}$ reaction within an effective-Lagrangian model
• Weak interaction axial form factors of the octet baryons in nuclear medium
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• Electroweak form factors of baryons in dense nuclear matter
• Quark model calculations of transition form factors at high photon virtualities