Bonn 2010 – wissenschaftliches Programm
HK 64.5: Vortrag
Freitag, 19. März 2010, 15:15–15:30, HG III
Transverse Λ and Λ polarization with a transversely polarized proton target at COMPASS* — •DONGHEE KANG — Institut für Kernphysik, Johannes Gutenberg Universität Mainz, D-55099 Mainz
The measurement of the transverse quark distribution functions ΔTq(x) is an important
part of the physics program of the COMPASS experiment at CERN.
The transversity distributions, being chiral-odd objects, are not directly accessible in
inclusive deep-inelastic scattering (DIS), but require the presence of another chiral-odd object.
They can be measured in semi-inclusive deep-inelastic scattering (SIDIS),
where this additional object is provided by the transversely polarized fragmentation functions
The most promising channels for the measurement of the transversity distributions in SIDIS
are the Collins effect, the azimuthal asymmetries in two hadrons production and the transverse
The transverse Λ and Λ polarization can be studied by measuring
the acceptance corrected angular distribution of its decay products.
At COMPASS, the data on the Λ and Λ hyperons produced
in SIDIS processes have been collected in 2007, using a beam of 160 GeV/c polarized µ+
scattering off a NH3 target.
The preliminary results on the transverse Λ and Λ polarization
as a function of xBj and z will be presented.
* This work is supported by the BMBF.