Measurement of the polarization of the $$\Upsilon(1S)$$ and $$\Upsilon(2S)$$ states in $$p\bar{p}$$ collisions at $$\sqrt{s}=$$1.96 TeV
We present a study of the polarization of the {Upsilon}(1S) and {Upsilon}(2S) states using a 1.3 fb{sup -1} data sample collected by the D0 experiment in 2002-2006 during Run II of the Fermilab Tevatron Collider. We measure the polarization parameter {alpha} = ({sigma}{sub T} - 2{sigma}{sub L})/({sigma}{sub T} + 2{sigma}{sub L}), where {sigma}{sub T} and {sigma}{sub L} are the transversely and longitudinally polarized components of the production cross section, as a function of the transverse momentum (p{sub T}{sup {Upsilon}}) for the {Upsilon}(1S) and {Upsilon}(2S). Significant p{sub T}{sup {Upsilon}}-dependent longitudinal polarization is observed for the {Upsilon}(1S). A comparison with theoretical models is presented.
- Research Organization:
- Fermi National Accelerator Laboratory (FNAL), Batavia, IL
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 927641
- Report Number(s):
- FERMILAB-PUB-08-089-E; arXiv eprint number arXiv:0804.2799
- Country of Publication:
- United States
- Language:
- English
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