Abstract
Nucleon resonance contributions to the inclusive proton ${F}_{2}$ and ${F}_{L}$ structure functions are computed from resonance electroexcitation amplitudes in the mass range up to 1.75 GeV extracted from CLAS exclusive meson electroproduction data, taking into account interference between different excited nucleon states. The resonance contributions are compared with inclusive proton structure functions evaluated from $(e,{e}^{\ensuremath{'}}X)$ cross section data and the longitudinal to transverse cross section ratio. Contributions from isospin-1/2 and -3/2 resonances remain substantial over the entire range of photon virtualities ${Q}^{2}\ensuremath{\lesssim}4\phantom{\rule{4pt}{0ex}}{\mathrm{GeV}}^{2}$, where their electroexcitation amplitudes have been obtained, and their ${Q}^{2}$ evolution displays pronounced differences in the first, second, and third resonance regions. We compare the structure functions in the resonance region with those computed from parton distributions fitted to deep-inelastic scattering data, and extrapolated to the resonance region, providing new quantitative assessments of quark-hadron duality in inclusive electron-proton scattering.
Highlights
Inclusive electron scattering from protons has for many years provided fundamental information on the structure of the nucleon
We present the results of our calculations of the resonance contributions to the inclusive proton F2 and FL structure functions from the experimental results on the γ ∗ pN∗ electrocouplings [102,104], and compare these with the structure functions extracted from experimental inclusive cross sections from CLAS [50] combined with empirical results on the RLT ratio from Hall C [54,55]
We examine the role of individual resonance contributions to the structure functions, and assess the importance of the interference effects computed from our coherent Ansatz relative to the incoherent approach from Ref. [104]
Summary
Inclusive electron scattering from protons has for many years provided fundamental information on the structure of the nucleon. The experimental program exploring exclusive π +n, π 0 p, ηp, and π +π − p electroproduction channels in the resonance region using the CLAS detector at Jefferson Lab has provided important new information on the nucleon resonance electroexcitation amplitudes, or γ ∗ pN∗ electrocouplings These include the electrocouplings of most nucleon resonances in the mass range W 1.75 GeV and Q2 5 GeV2 [97,98,99,100,101,102], as well as the new baryon state N (1720) 3/2+ observed in combined studies of the π +π − p photo- and electroproduction data [103]. In the Appendix, for completeness we collect the main formulas for target mass corrections from the OPE and collinear factorization approaches
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
