# SPIN 2014 abstract

Intended only as a backup, if the PANIC abstract doesn't work out.

LaTeX pasted in below.  PDF attached.

Neutral Pion Spin Asymmetries and Cross Section at $0.8 < \eta < 2.0$ in p+p Collisions at $\sqrt{s} = 200$ GeV and $\sqrt{s} = 510$ GeV at STAR

Adam Gibson for the STAR Collaboration
Department of Physics and Astronomy, Valparaiso University, Valparaiso, IN 46383, USA

The STAR endcap electromagnetic calorimeter (EEMC) was designed to
allow measurement of cross sections and spin observables in an
intermediate pseudorapidity range, $0.8 < \eta < 2.0$, and with full
azimuth.  Using the EEMC to measure double longitudinal spin asymmetries
in photonic channels---such as inclusive neutral pions, prompt photon, and
prompt photon + jet---allows access to $\Delta G$ covering a lower
Bjorken-$x$ region than current mid-rapidity measurements. A recent global
analysis including those mid-rapidity results has, for the first time,
yielded evidence of a positive $\Delta g$ in the region $0.05 < x < 0.2$.
But, the gluon polarization remains under-constrained for the region
$x < 0.05$, motivating the extension of these measurements into a lower $x$ region.
Transverse spin asymmetries have been shown to be near zero at
$\eta$ near zero and as large as 10\% at $\eta$ near four.  When measured
with the EEMC at intermediate pseudorapidity they occupy a previously
unmeasured region in the 3D pseudorapidity, transverse momentum, and
Feynman-$x$ phase space. The neutral pion cross section measurement
verifies that the signal of interest can be properly reconstructed and
isolated from the background and can quantify the applicability of pQCD
predictions.

Recently published results for the neutral pion cross
section, transverse, and double longitudinal spin asymmetries using the
2006 dataset from STAR, p+p collisions at $\sqrt{s} = 200$ GeV, will be presented.
Higher $\sqrt{s}$ collisions allow us to probe even lower Bjorken-$x$.
The status of the neutral pion double longitudinal asymmetry analysis
with a much larger dataset at $\sqrt{s} = 510$ GeV from 2012
at STAR will be shown.

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