Various flow phenomena of black particles （b-particles） and grey particles （g-particles） produced in magnesium-emulsion （Mg-Em） collisions at 4.5 A GeV/c are reported. These flows are directed and elliptic trans...Various flow phenomena of black particles （b-particles） and grey particles （g-particles） produced in magnesium-emulsion （Mg-Em） collisions at 4.5 A GeV/c are reported. These flows are directed and elliptic transverse flows （v1 and v2） related by the azimuthal angle （φ）, directed and elliptic reaction plane flows （vR1 and vR2） related by the projected angle （φ） on the reaction plane, and directed and elliptic polar direction flows （vp1 and vp2） related by the polar angle （ ）. We extract absolute flows as the direct experimental values minus the isotropic theoretical values. The dependence of the various flows on the target particle multiplicity and on the angles （ ,φ,φ） is investigated. Our results show that the dependence of b-particle flows on the target size is obvious and for heavy targets the dependence on target particle multiplicity is slight. Compared with b-particles, g-particles have a slight dependence on the target size and target particle multiplicity.展开更多
基金Supported by National Natural Science Foundation of China (10975095,10675077)Natural Science Foundation of Shanxi Province (2007011005)
文摘Various flow phenomena of black particles （b-particles） and grey particles （g-particles） produced in magnesium-emulsion （Mg-Em） collisions at 4.5 A GeV/c are reported. These flows are directed and elliptic transverse flows （v1 and v2） related by the azimuthal angle （φ）, directed and elliptic reaction plane flows （vR1 and vR2） related by the projected angle （φ） on the reaction plane, and directed and elliptic polar direction flows （vp1 and vp2） related by the polar angle （ ）. We extract absolute flows as the direct experimental values minus the isotropic theoretical values. The dependence of the various flows on the target particle multiplicity and on the angles （ ,φ,φ） is investigated. Our results show that the dependence of b-particle flows on the target size is obvious and for heavy targets the dependence on target particle multiplicity is slight. Compared with b-particles, g-particles have a slight dependence on the target size and target particle multiplicity.
