Transverse single-spin asymmetry of forward mesons in collisions at GeV
NJ Abdulameer, U Acharya, C Aidala… - arXiv preprint arXiv …, 2025 - arxiv.org
NJ Abdulameer, U Acharya, C Aidala, NN Ajitanand, Y Akiba, R Akimoto, J Alexander…
arXiv preprint arXiv:2509.13497, 2025•arxiv.orgUtilizing the 2012 transversely polarized proton data from the Relativistic Heavy Ion Collider
at Brookhaven National Laboratory, the forward $\eta $-meson transverse single-spin
asymmetry ($ A_N $) was measured for $ p^{\uparrow}+ p $ collisions at $\sqrt {s}= 200$
GeV as a function of Feynman-x ($ x_F $) for $0.2<| x_F|< 0.8$ and transverse momentum ($
p_T $) for $1.0< p_T< 5.0$ GeV/$ c $. Large asymmetries at positive $ x_F $ are observed
($\left< A_N\right>= 0.086\pm 0.019$), agreeing well with previous measurements of $\pi^{0} …
at Brookhaven National Laboratory, the forward $\eta $-meson transverse single-spin
asymmetry ($ A_N $) was measured for $ p^{\uparrow}+ p $ collisions at $\sqrt {s}= 200$
GeV as a function of Feynman-x ($ x_F $) for $0.2<| x_F|< 0.8$ and transverse momentum ($
p_T $) for $1.0< p_T< 5.0$ GeV/$ c $. Large asymmetries at positive $ x_F $ are observed
($\left< A_N\right>= 0.086\pm 0.019$), agreeing well with previous measurements of $\pi^{0} …
Utilizing the 2012 transversely polarized proton data from the Relativistic Heavy Ion Collider at Brookhaven National Laboratory, the forward -meson transverse single-spin asymmetry () was measured for collisions at GeV as a function of Feynman-x () for and transverse momentum () for GeV/. Large asymmetries at positive are observed (), agreeing well with previous measurements of and , but with reach to higher and . The contribution of initial-state spin-momentum correlations to the asymmetry, as calculated in the collinear twist-3 framework, appears insufficient to describe the data and suggests a significant impact on the asymmetry from fragmentation.
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