Kevin has found some very nice charge separation in the Run-12 Collins asymmetries. The question has been raised, then, given appropriate scaling do we see the same effects at 500 GeV? To this point, I have only looked at Collins asymmetries as a function of p_T for VPDMB triggers. Here, I look at all triggers as a function of p_T.

Figure 1: Collins vs. p_T

For appropriate scaling, I would need to look at p_T > 25 GeV/c. Unfortunately, above 25 statistics quickly run thin, in particular, at high z. There is a tantalizing behavior in mid-z around 15-20 GeV/c. Integrating the distributions from 14-23 GeV/c, I find 0.00461±0.00673 for π⁺ and -0.0187±0.00694 for π^-. For p_T > 10 GeV/c, I find 0.00658±0.00446 for π⁺ and -0.00792±0.00456 for π^-. The behavior is not detectible at high-z where statistics are simply too low.