Nonperturbative effects in the proton sea

dc.creatorSchäfer, W.
dc.creatorSpeth, J.
dc.date1999-08-30
dc.date.accessioned2026-07-07T04:07:56Z
dc.date.available2026-07-07T04:07:56Z
dc.descriptionWe revisit the evaluation of the pionic mechanism of the $\bar{u}-\bar{d}$-asymmetry in the proton structure function. Our analysis is based on the unitarity relation between contributions of different mechanisms to the inclusive particle production and the total photoabsorption cross-section (i.e. the proton structure function). We reanalyze the role of isovector reggeons in inclusive production of nucleons and Delta isobars in hadronic reactions. A rather large contribution of reggeon-exchange induced production of Delta isobars is found. This leaves much less room for the pion-exchange induced mechanism of $Δ$ production and provides a constraint on the $πN Δ$ form factor. The production of leading pions in proton-proton collisions puts additional constraints on the $πNN$ vertex form factors. All these constraints are used then to estimate the pion content of the nucleon and allow to calculate parameter-free the x-dependence of $\bar d - \bar u$. We discuss the violation of the Gottfried Sum Rule and $\bar d$-$\bar u$ asymmetry and compare to the one obtained from the E866 experiment at Fermilab.
dc.description8 pages, 5 eps-figures. Talk given at the 6th INT / JLAB Workshop on Exclusive and Semiexclusive Processes at High Momentum Transfer, Newport News, VA, 19-23 May 1999
dc.identifierhttps://arxiv.org/abs/hep-ph/9908503
dc.identifierhttp://arxiv.org/abs/hep-ph/9908503
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/49338
dc.subjectHigh Energy Physics - Phenomenology
dc.titleNonperturbative effects in the proton sea
dc.typetext

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