CTEQ Handbook Version 1.0 Errata Here we only record substantive corrections, but all corrections are welcome. Send to scalise@phys.psu.edu. ------------------------------------------------------------------ Equations (4.49) to (4.50) should read \begin{eqnarray} P_{11}^{{\rm hel}} \equiv P_{22}^{{\rm hel}} = 0, \\ P_{12}^{{\rm hel}} \equiv -P_{21}^{{\rm hel}} = -i, \nonumber \\ P_{n,jj'}^{{\rm lin}} \equiv 2 n_{j}n_{j'} - \delta _{jj'}. \end{eqnarray} The correction is to the sign of $P^{\rm hel}$. This can be checked by observing that the transverse parts of the polarization vectors for gluons with helicity $\lambda$ are \begin{displaymath} \left( \epsilon^1(\lambda),\epsilon^2(\lambda) \right) = - \frac{1}{\sqrt 2}\ \left( \lambda,i \right) \end{displaymath} (up to an overall phase), and that the matrix $P_{jj'}^{\rm hel}$ should be \begin{displaymath} P^{jj'} = \sum_{\lambda = \pm 1} \lambda\, \epsilon^j(\lambda) \epsilon^{j'}(\lambda)^* \end{displaymath} We need to be careful that this is the matrix and not its transpose. The $\epsilon^*$ multiplies the gluon destruction operator. ------------------------------------------------------------------ Equation 6.26 should read: [(1+x^2)/(1-x)]_+ = P_{qq}^(1)(x) = (1+x^2)/[1-x]_+ + 3/2 \delta(1-x) ------------------------------------------------------------------