Angular distributions of leptons from J/psi's produced in 920 GeV fixed-target proton-nucleus collisions

	Angular distributions of leptons from J/psi's produced in 920 GeV fixed-target proton-nucleus collisions
	HERA-B Collaboration
刊名	EUROPEAN PHYSICAL JOURNAL C
	2009
卷号	60 期号:4 页码:#REF!
通讯作者	Abt, I (reprint author), NIKHEF, NL-1009 DB Amsterdam, Netherlands.
英文摘要	A study of the angular distributions of leptons from decays of J/psi's produced in p-C and p-W collisions at root s = 41.6 GeV has been performed in the J/psi Feynman-x region -0.34 < x(F) < 0.14 and for J/psi transverse momenta up to 5.4 GeV/c. The data were collected by the HERA-B experiment at the HERA proton ring of the DESY laboratory. The results, based on a clean selection of 2.3 x 10(5) J/psi's reconstructed in both the e(+)e(-) and mu(+)mu(-) decay channels, indicate that J/psi's are produced polarized. The magnitude of the effect is maximal at low p(T). For p(T) > 1 GeV/c a significant dependence on the reference frame is found: the polar anisotropy is more pronounced in the Collins-Soper frame and almost vanishes in the helicity frame, where, instead, a significant azimuthal anisotropy arises.
学科主题	Physics
类目[WOS]	Physics, Particles & Fields
收录类别	SCI
WOS记录号	WOS:000265215100001
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/227708]
专题	高能物理研究所_实验物理中心
推荐引用方式 GB/T 7714	HERA-B Collaboration. Angular distributions of leptons from J/psi's produced in 920 GeV fixed-target proton-nucleus collisions[J]. EUROPEAN PHYSICAL JOURNAL C,2009,60(4):#REF!.
APA	HERA-B Collaboration.(2009).Angular distributions of leptons from J/psi's produced in 920 GeV fixed-target proton-nucleus collisions.EUROPEAN PHYSICAL JOURNAL C,60(4),#REF!.
MLA	HERA-B Collaboration."Angular distributions of leptons from J/psi's produced in 920 GeV fixed-target proton-nucleus collisions".EUROPEAN PHYSICAL JOURNAL C 60.4(2009):#REF!.