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We present the midrapidity charged pion invariant cross sections and theratio of $\pi^-$-to-$\pi^+$ production ($5<p_T<13$ GeV/$c$), together with thedouble-helicity asymmetries ($5<p_T<12$ GeV/$c$) in polarized $p$$+$$p$collisions at $\sqrt{s} = 200$ GeV. The cross section measurements areconsistent with perturbative calculations in quantum chromodynamics withinlarge uncertainties in the calculation due to the choice of factorization,renormalization, and fragmentation scales. However, the theoretical calculationof the ratio of $\pi^-$-to-$\pi^+$ production when considering these scaleuncertainties overestimates the measured value, suggesting furtherinvestigation of the uncertainties on the charge-separated pion fragmentationfunctions is needed. Due to cancellations of uncertainties in the charge ratio,direct inclusion of these ratio data in future parameterizations should improveconstraints on the flavor dependence of quark fragmentation functions to pions.By measuring charge-separated pion asymmetries, one can gain sensitivity to thesign of $\Delta G$ through the opposite sign of the up and down quark helicitydistributions in conjunction with preferential fragmentation of positive pionsfrom up quarks and negative pions from down quarks. The double-helicityasymmetries presented are sensitive to the gluon helicity distribution over an$x$ range of $\sim$0.03--0.16.

Inclusive cross sections, charge ratio and double-helicity asymmetries  for $\pi^+$ and $\pi^-$ production in $p$$+$$p$ collisions at $\sqrt{s}$=200  GeV