LHC Physics Potential vs. Energy: Considerations for the 2011 Run

Parton luminosities are convenient for estimating how the physics potential of Large Hadron Collider experiments depends on the energy of the proton beams. I quantify the advantage of increasing the beam energy from 3.5 TeV to 4 TeV. I present parton luminosities, ratios of parton luminosities, and contours of fixed parton luminosity for $gg$, $u\bar{d}$, $qq$, and $gq$ interactions over the energy range relevant to the Large Hadron Collider, along with example analyses for specific processes. This note extends the analysis presented in arXiv:0908.3660. Full-size figures are available as pdf files at http://lutece.fnal.gov/PartonLum11/