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DOE OSTI Β· 21361999

Spin physics at RHIC

Goto, Yuji
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Abstract

Polarized-proton collisions at a collision energy 200 GeV started in 2001 at RHIC in BNL. We have investigated a polarized structure of the proton to understand the origin of the nucleon spin 1/2 with polarized-proton collisions. The first goal of spin physics at RHIC is determination of the gluon-spin contribution to the proton spin. The PHENIX and STAR experiments have investigated the gluon-spin contribution by measuring longitudinal-spin asymmetries of neutral pion and jet produced in longitudinally-polarized proton collisions. Experimental results have shown that these asymmetries are small and strong constraints have been given for the gluon-spin contribution. From 2009, polarized-proton collisions at a collision energy 500 GeV started and we have investigated flavor-sorted contribution of the quark spin to the proton spin with weak-boson production. The final remaining piece of information to understand the proton spin is orbital-angular momenta of quarks and gluons. Multi-dimensional structure of the nucleon which includes information of the orbital-angular motion inside the nucleon has been investigated with transverse-spin asymmetry measurements.

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72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDSACCELERATORSANGULAR MOMENTUMASYMMETRYBARYONSBEAMSBNLBOSONSBROOKHAVEN RHICCOMPOSITE MODELSELEMENTARY PARTICLESENERGY RANGEFERMIONSFLAVOR MODELGEV RANGEGEV RANGE 100-1000GLUONSHADRONSHEAVY ION ACCELERATORSMATHEMATICAL MODELSMESONSNATIONAL ORGANIZATIONSNUCLEONSORBITAL ANGULAR MOMENTUMPARTICLE MODELSPARTICLE PROPERTIESPIONSPIONS NEUTRALPOLARIZED BEAMSPROTONSPSEUDOSCALAR MESONSQUARK MODELQUARKSSPINSTORAGE RINGSUS AECUS DOEUS ERDAUS ORGANIZATIONS

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BibTeXRIS

Goto, Yuji. 2010-05-12. Spin physics at RHIC. https://doi.org/10.1063/1.3442577

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