Speaker
Peter Plößl
(Deutsches Elektronen-Synchrotron DESY)
Description
Double parton scattering (DPS) and double parton distributions (DPDs) are
sensitive to non-trivial colour correlations between partons inside a hadron. At
small inter-parton distances the leading contribution to DPDs is due to a
perturbative splitting mechanism, which makes it possible to calculate DPDs in
perturbation theory in this regime. We compute this contribution at
next-to-leading (NLO) order for all possible colour correlations.
With these NLO DPDs we can show that positivity bounds for colour space DPDs can
be violated at NLO. We furthermore find that even at LO positivity can be
violated by evolution from lower to higher scales, in contrast to the situation
for ordinary PDFs and for colour singlet DPDs.
Primary author
Peter Plößl
(Deutsches Elektronen-Synchrotron DESY)
Co-authors
Jonathan Gaunt
(University of Manchester)
Markus Diehl
(Deutsches Elektronen-Synchrotron DESY)
