Writing single particle states in Peskin and Schroeder notation

[maverick280857]

Hello,

In the notation adopted by Peskin and Schroeder, the single particle state is

$$\left|\boldsymbol{p}_1, s_1\right\rangle = \sqrt{2 E_{p}} {a_{p_1}^{s_1}}^{\dagger}\left|0\right\rangle$$

How does one write down

$$\left\langle r|\boldsymbol{p}_1, s_1\right\rangle = \sqrt{2 E_{p}} \left\langle r|{a_{p_1}^{s_1}}^{\dagger}|0\right\rangle$$

?

Thanks in advance..

 

[maverick280857]

Any ideas, anyone? This ought to be connected to the Dirac field \psi(x) and its adjoint, but I don't see how to isolate the particle (antiparticle) contribution..