8 research outputs found
Village‐specific Kula partnerships revealed by obsidian sourcing on Tubetube Island, Papua New Guinea
The late prehistoric introduction of pottery to Rossel Island, Louisiade Archipelago, Papua New Guinea: Insights into local social organisation and regional exchange in the Massim
Measurement of the reaction gamma* p --> phi p in deep inelastic e+ p scattering at HERA
The production of mesons in the reaction (), for GeV and for
virtual photon-proton centre of mass energies () in the range 42-134 GeV,
has been studied with the ZEUS detector at HERA. When compared to lower energy
data at similar , the results show that the \gamma^*p \rightarrow \phid
p cross section rises strongly with . This behaviour is similar to that
previously found for the cross section. This
strong dependence cannot be explained by production through soft pomeron
exchange. It is, however, consistent with perturbative QCD expectations, where
it reflects the rise of the gluon momentum density in the proton at small .
The ratio of , which has previously been
determined by ZEUS to be 0.065 0.013 (stat.) in photoproduction at a mean
of 70 GeV, is measured to be 0.18 0.05 (stat.) 0.03 (syst.) at
a mean of 12.3 GeV and mean of 100 GeV and is thus
approaching at large the value of 2/9 predicted from the quark charges of
the vector mesons and a flavour independent production mechanism.Comment: 22 pages, including 4 figures. Includes some minor editorial change