Quark Asymmetries and Intrinsic Charm in Nucleons
2005 (English)Report (Other scientific)
We have developed a physical model for the non-perturbative x-shape of parton density functions in the proton, based on Gaussian fluctuations in momenta, and quantum fluctuations of the proton into meson-baryon pairs. The model describes the proton structure function and gives a natural explanation of observed quark asymmetries, such as the difference between the anti-up and anti-down sea quark distributions and between the up and down valence distributions. We find an asymmetry in the momentum distribution of strange and anti-strange quarks in the nucleon, large enough to reduce the NuTeV anomaly to a level which does not give a significant indication of physics beyond the standard model. We also consider charmed fluctuations, and show that they can explain the excess at large x in the EMC F2c data.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:uu:diva-77165OAI: oai:DiVA.org:uu-77165DiVA: diva2:105077
Extended version of talk given at DIS 2005, Madison, USA, April 27-May 1, 20052006-03-132006-03-13