I have some questions regarding Jack polynomials. I use the notation of of I.G. Macdonald's book "Symmetric Functions and Hall polynomials".

Let $\Lambda$ be the ring of symmetric functions over $\mathbb{C}$ (in countably infinitely many variables $x_i$). For a partition $\mu=(\mu_1,\mu_2,\dots)$ let $p_\mu$ denote the power sums, i.e., $p_\mu=p_{\mu_1}p_{\mu_2}\cdots$ and
$p_{\mu_i}=\sum_k x_k^{\mu_i}$.

Let $\langle\ ,\ \rangle^{\alpha}$ be the inner product given by
$\langle p_\mu,p_\nu\rangle=\delta_{\mu,\nu}\alpha^{\ell(\mu)}z_\mu$, where $\alpha\in\mathbb{C}$, $\ell(\mu)$ is the length of the partition $\mu$, $z_\mu=\prod_{i\in\mu}i^{m_i(\mu)}\cdot m_i(\mu)!$ and $m_i(\mu)$ is the multiplicity of $i$ in $\mu$.

The Jack symmetric functions $P_\mu^{(\alpha)}$ form a basis of $\Lambda$ indexed by partitions and are characterised by 2 properties:

 1. $P_\mu^{(\alpha)}=m_\mu + \sum_\nu u_{\mu,\nu}(\alpha)m_\nu$,
where the $m_\nu$ are symmetric monomials, the $u_\nu(\alpha)\in\mathbb{C}$ and the summation index runs over all partitions $\nu <\mu$ in the dominance ordering.
 2. The Jack symmetric functions are mutually orthogonal 
$\langle P_\mu^{(\alpha)} ,P_\nu^{(\alpha)} \rangle^{\alpha}=0$ if $\mu\neq\nu$.

In fact explicit formulae for $\langle P_\mu^{(\alpha)}, P_\mu^{(\alpha)}\rangle^{\alpha}$ are know, but rather complicated, so I won't list them here.

**Question:** What happens when I vary the parameter $\alpha$ of the inner product, but not for the Jack polynomials? Does anyone know how to evaluate
$\langle P_\mu^{(\alpha)} ,P_\nu^{(\alpha)} \rangle^{\beta}$, $\beta\in\mathbb{C}$? I am most interested in the case $\beta=-2\alpha$.