The d̄ − ū asymmetry of the proton in a Pion Cloud Model approach

We study the d̄− ū asymmetry of the proton in a model approach in which hadronic fluctuations of the nucleon are generated through gluon splitting and recombination mechanisms. Within this framework, it is shown that the d̄ − ū asymmetry of the proton is consistently described by including only nucleon fluctuations to |πN〉 and |π∆〉 bound states. Predictions of the model closely agree with the recent experimental data of the E866/NuSea Collaboration. Recently, the E866/NuSea Collaboration has measured a noticeable d̄− ū asymmetry in the proton sea [1]. Actually, the d̄ − ū asymmetry in the nucleon’s sea and the consequent Gottfried Sum Rule (GSR) [2] violation were known since the New Muon Collaboration (NMC) experiment in the early 90’s [3]. However, the origin of such asymmetry has remained unclear since then. Several ideas have been put forward to try to explain the GSR violation and the d̄ − ū asymmetry in nucleons. Among them the Pauli exclusion e-mail: [email protected] e-mail: [email protected]