Abstrakt
Investigation of GPDs and TMDs represents one of the major goals of the COMPASS-II program. Together, GPDs and TMDs provide the most complete description of the partonic structure of the nucleon.
GPDs can be accessed by lepton-induced exclusive scattering processes, such as Deep Virtual Compton Scattering or Hard Exclusive Meson Production. The exclusive π0 production is the main source of background for the DVCS, and it provides complementary information on GPD parametrization.
The dedicated GPD program started with a pilot run in 2012, followed by data taking in 2016-2017, using 160 GeV/c muon beam and a liquid hydrogen target. A recoil proton detector surrounding the target and an additional electromagnetic calorimeter were added to complete the COMPASS spectrometer.
We will present the first measurement from 2012 of the exclusive π0 cross section and its φ and |t|-dependence in the xBj domain from 0.01 to 0.15. These results will be compared with the phenomenological Goloskokov-Kroll model.
A prospect will be given on upcoming results of the 2016-17 measurement.