| Popis: |
The upgraded Collider Detector at Fermilab (CDF II) has a high bandwidth available for track based triggers. This capability, in conjunction with an integrated luminosity in excess of 1 fb −1 , enables detailed studies of charm hadron production. CDF is now releasing first measurements of the prompt charm meson pair cross-sections, which give access to QCD mechanisms by which charm quarks are produced in proton anti-proton collisions. Recent results on the spin alignment of J / ψ and ψ ( 2 S ) as well as on the relative production of the χ c 1 ( P 1 ) and χ c 2 ( 1 P ) challenge our understanding of the fragmentation of charm quarks into charmonium states. |
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