9-14 September 2018
University of Ferrara
Europe/Rome timezone

K-/K+ multiplicity ratio in SIDIS from COMPASS

13 Sep 2018, 14:50
A10 (Polo degli Adelardi - Via Adelardi, 33)


Polo degli Adelardi - Via Adelardi, 33

Parallel Sessions Nucleon Helicity Structure Nucleon helicity structure


Dr fabienne kunne (CEA saclay)


For the first time, the K-/K+ multiplicity ratio was measured in deep-inelastic scattering for kaons carrying a large fraction z of the virtual-photon energy. The data were obtained using a 160 GeV muon beam and an isoscalar 6LiD target. They cover the range 0.01 < x < 0.4, z> 0.75, Q2 > 1 (GeV/c)2, and W > 5 GeV/c2. For values of z larger than 0.8, the results contradict expectations obtained using the formalism of (next-to-) leading order perturbative quantum chromodynamics. In particular, the K-/K+ data shows a strong dependence upon the missing mass Mx, not expected from the calculations. The results suggest that additional corrections to the formalism may be required to take into account the phase space available for hadronization.

Primary author

Dr fabienne kunne (CEA saclay)

Presentation Materials