Search for a new state of matter – the QuarkGluon Plasm一個(gè)物質(zhì)–夸克膠子等離子體的新狀態(tài)搜索

1、1evidence for multi-parton dynamics in hadronization of bulk partonic matter at rhichuan zhong huang (黃煥中黃煥中)department of physics and astronomyuniversity of california los angelesdepartment of engineering physicstsinghua university7th annual conference of chinese high energy physics society2outline

2、 relativistic heavy ion collider (rhic) and quark-gluon plasma (qgp) fragmentation scheme hadronization of bulk partonic matter recent results of high pt probes outlook3starrelativistic heavy ion collider - rhicau+au 200 gev n-n cm energypolarized p+p up to 500 gev cm energy4quark-hadron phase trans

3、ition5au + au collisions at rhiccentral event(real-time level 3)6nucleus-nucleus collisions and volcanic eruptionvolcanic high pt - strombolian eruption volcanic mediate pt spatter (clumps)volcanic low pt bulk matter flows7kretzerismd048baryon production from pqcdp pkkppp pe+e-jet fragmentation from

4、 sldnormal fragmentation cannot produce the large baryon yield9too many baryons at intermediate pt10elliptic flow parameter v2yxpypxcoordinate-space-anisotropy momentum-space-anisotropyinitial/final conditions, dof, eos 1iritttt)cos(i(2v1dydppdn21dyddppdn 11elliptic flow: ultra-cold fermi-gasli-atom

5、s released from an optical trap exhibit elliptic flow analogous to what is observed in ultra-relativistic heavy-ion collisions elliptic flow is a general feature of strongly interacting systems!12hydro calculations break-down at higher pt (as expected).how is v2 established at pt above 2 gev/c?why i

6、s baryon v2 larger than meson v2?prl 92 (2004) 052302; prl 91 (2003) 182301 elliptic flow v213constituent quark degree of freedomks two quark coalescencel three quark coalescence from the partonic matter surface?!particle v2 may be related to quark matter anisotropy !pt nk a feature not present in s

7、ingle parton fragmentation !multi-parton dynamics: coalescence, recombination and gluon junctions.rcprcp=yield/n-ncentralyield/n-nperipheral41starphenixparticle dependence of v2baryonmesonwhy saturation at intermediate pt ?why baryon and meson difference ?42spin physics programthe spin structure of the proton: = s sd dq + d dg + q up, down and strange quarksg gluonsl angular momentum of quarks and gluonsexperimentally: 1) total spin in quarks 30%