Cross Sections and Transverse Single-Spin Asymmetries in Forward Neutral-Pion Production from Proton Collisions ats=200  GeV

Abstract

Measurements of the production of forward high-energy pi(0) mesons from transversely polarized proton collisions at sqrt[s]=200 GeV are reported. The cross section is generally consistent with next-to-leading order perturbative QCD calculations. The analyzing power is small at x(F) below about 0.3, and becomes positive and large at higher x(F), similar to the trend in data at sqrt[s]< or =20 GeV. The analyzing power is in qualitative agreement with perturbative QCD model expectations. This is the first significant spin result seen for particles produced with p(T)>1 GeV/c at a polarized proton collider.

Scaling properties at freeze-out in relativistic heavy-ion collisions

“…Copper nuclei ( 63 Cu) were collided at √ s NN = 200 and 62.4 GeV. Data were recorded with a minimum bias trigger obtained from the beambeam Cherenkov counters [10] coupled with information from the zero-degree calorimeters [11]. This trigger is found to be sensitive to the top ∼85% of the inelastic cross section.…”

Single-spin asymmetry ofJ/ψproduction inp+p,p+Al, andAidala1, Akiba2, Alfred3 et al. 2018Phys. Rev. DSelf Cite211180View full textAdd to dashboardCite

“…In the trigluon correlation, the two parton composite state is composed of two gluons instead of a quark and gluon as described above for the QiuSterman correlation [11,15]. The collinear factorization framework has been widely used to describe the TSSA's measured at RHIC [16][17][18][19][20][21][22][23].…”

Azimuthal transverse single-spin asymmetries of inclusive jets and charged pions within jets from polarized-proton collisions at s=500 GeV

“…The corrected pion asymmetry is calculated as the pion, kaon, and proton fractions from the proton-rich sample. Equation (12) assumes the electron asymmetry is negligible. The electron contamination is dominated by photonic electrons, largely from π 0 decay photons, and heavy flavor decays.…”