Analysis of weak-interaction effects in high-transverse-momentum hadron-hadron collisions. II. Implications of quantum chromodynamics

Parity-violating (pv) weak effects in inclusive hadron and jet production are studied in the framework of quantum chromodynamics (QCD). Results are given for the asymmetry parameter $\mathcal{a}$ for the processes $p+p\to {\pi }^{+}+X$ and $p+p\to \mathrm{jet}+X(X=\mathrm{anything})$, where $\mathcal{a}$ measures the difference in the inclusive cross sections for protons incident with ± helicity. We also calculate the longitudinal polarization $\mathcal{p}$ of $\Lambda$'s in $p+p\to \Lambda +X$ where the initial protons are unpolarized. Such effects arise from the coherent interference between the strong-QCD amplitude, which is parity conserving, and the pv weak amplitude. Due to the interplay between the weak amplitude (which changes flavor but conserves color) and the strong amplitude (which conserves flavor but changes color), only a limited number of parton scattering processes contribute to $\mathcal{a}$ or $\mathcal{p}$. In particular, it is shown that through order $G_F{g_s}^3$, where $G_F$ is the Fermi constant and $g_s$ is the strong quark-quark-gluon coupling constant, the only contributions to $\mathcal{a}$ or $\mathcal{p}$ arise from the interference between a strong quark-quark scattering amplitude in one channel ($\hat{s}$, $\hat{t}$, or $\hat{u}$) and a weak quark-quark amplitude in a different channel. Numerical results are presented for $\mathcal{a}$ and $\mathcal{p}$ as a function of the center-of-momentum energy $\sqrt{s}$ and $x_{\perp }=\frac{2p_{\perp }}{\sqrt{s}}$, where $p_{\perp }$ is the transverse momentum of the inclusively produced hadron or jet relative to the incoming beam. These results are qualitatively similar to those obtained previously using the phenomenological effective-gluon model of the strong amplitude, although they are somewhat smaller in magnitude for reasons which are discussed. A detailed summary is also given of recent calculations of inclusive strong production.