Speaker
Heikki Mäntysaari
(University of Jyväskylä)
Description
Deep inelastic scattering is a powerful tool to
study the structure of hadrons and test our understanding of the strong
interaction. The precise proton structure
function measurements done at HERA have been a crucial test for
the Color Glass Condensate effective field
theory description of the high energy hadronic interactions.
Ideally one would want to continue the analysis with nuclear targets where
gluon saturation effects are expected to be even stronger.
Because the role of the electron in DIS events is to only act as a source of virtual
photons, one can study the same physics in ultraperipheral (large impact
parameter) heavy ion collisions. In these events the dominant process is the
one where one nucleus acts as a photon source, and one is left with a
similar photon-nucleus scattering as in DIS.
Recently diffractive vector meson production in ultraperipheral collisions has
gained a lot of theoretical and experimental attention, because the cross section
is especially sensitive to the saturation effects and also probes the spatial
distribution of gluons. For example the ALICE collaboration has measured the
diffractive J/Psi cross sections in lead-lead collisions [1].
We calculate coherent and incoherent diffractive vector meson production from
the Color Glass Condensate framework and compare our results and predictions
with the ALICE data. We discuss the dependence on the vector meson properties and
the modelling uncertainties. We also present predictions for proton-nucleus
collisions. [2]
[1] ALICE collaboration, Phys. Lett. B718 (2013) 1273,
Eur.Phys.J. C73 (2013) 2617
[2] T. Lappi, H. Mäntysaari, Phys.Rev. C87 (2013) 032201,
Phys.Rev. C83 (2011) 065202
Author
Heikki Mäntysaari
(University of Jyväskylä)
Co-author
Tuomas Lappi
(University of Jyvaskyla)
