Observation of Transverse Spin-Dependent Azimuthal Correlations of Charged Pion Pairs in $p^\uparrow+p$ at $\sqrt{s}=200$ GeV

The STAR collaboration Adamczyk, L. ; Adkins, J.K. ; Agakishiev, G. ; et al.
Phys.Rev.Lett. 115 (2015) 242501, 2015.
Inspire Record 1357596 DOI 10.17182/hepdata.73282

We report the observation of transverse polarization-dependent azimuthal correlations in charged pion pair production with the STAR experiment in $p^\uparrow+p$ collisions at RHIC. These correlations directly probe quark transversity distributions. We measure signals in excess of five standard deviations at high transverse momenta, at high pseudorapidities eta>0.5, and for pair masses around the mass of the rho-meson. This is the first direct transversity measurement in p+p collisions. Comparing the results to data from lepton-nucleon scattering will test the universality of these spin-dependent quantities.

15 data tables match query

$p_T$ asymmetries, $\eta$ < 0, maximum opening angle of 0.2.

$<M_{inv}>$ asymmetries, $\eta$ < 0, maximum opening angle of 0.2.

$p_T$ asymmetries, $\eta$ > 0, maximum opening angle 0.2.

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