Naslov
Transverse single-spin asymmetry and cross section for π0 and η mesons at large Feynman x in p↑+p collisions at √s=200  GeV

Autori
Adamczyk, L. ; ... ; Planinić, Mirko ; ... ; Poljak, Nikola ; ... ; Zoulkarneeva, Y.

Izvornik
Physical Review D - Particles, Fields, Gravitation, and Cosmology (1550-7998) 86 (2012); 051101-1

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
spin; asymmetry; meson; STAR

Sažetak
Measurements of the differential cross section and the transverse single-spin asymmetry, AN, vs xF for π0 and η mesons are reported for 0.4<xF<0.75 at an average pseudorapidity of 3.68. A data sample of approximately 6.3  pb-1 was analyzed, which was recorded during p↑+p collisions at √s=200  GeV by the STAR experiment at RHIC. The average transverse beam polarization was 56%. The cross section for π0, including the previously unmeasured region of xF>0.55, is consistent with a perturbative QCD prediction, and the η/π0 cross-section ratio agrees with existing midrapidity measurements. For 0.55<xF<0.75, the average AN for η is 0.210±0.056, and that for π0 is 0.081±0.016. The probability that these two asymmetries are equal is ∼3%.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

Napomena
STAR Collaboration.

POVEZANOST RADA