The ".e" and ".p" tags in the file-names indicates the nature of the particle: if the tag is R or L, the initial particle is an electron or positron with the indicated polarisation. Otherwise, it indicates the nature of the photon on the electron or positron side: .eB or .pB means that the photon on the electron or positron side was a real photon from the photon component of the beam, while .eW or .pW means that it was a virtual (Weizsaecker-Williams) photon radiated off the lepton.
For the final states, e is electron-positron, l other charged lepton, n is neutrino, x is up-type quark and y is down-type quark.
The links below brings you to the relevant pages at SLAC.
2048 May 29 18:05 gamma e to 1f or 3f
2048 May 29 18:05 gamma e to 5f
2048 May 29 18:05 gammagamma to 2f
2048 May 29 18:05 gammagamma to 4f
2048 May 29 18:05 low pt gammagamma
2048 May 29 18:05 minijets
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