Distinct doping dependences of the pseudogap and superconducting gap   La$_{2-x}$Sr$_{x}$CuO$_4$ cuprate superconductors
  We have performed a temperature-dependent angle-integrated photoemission study of lightly-doped to heavily-overdoped La$_{2-x}$Sr$_{x}$CuO$_4$ and oxygen-doped La$_2$CuO$_{4.10}$. We found that both the magnitude $\Delta$* of the (small) pseudogap and the temperature \textit{T}* at which the pseudogap is opened increases with decreasing hole concentration, consistent with previous studies. On the other hand, the superconducting gap $\Delta_{sc}$ was found to remain small for decreasing hole concentration. The results can be explained if the superconducting gap opens only on the Fermi arc around the nodal (0,0)-($\pi,\pi$) direction while the pseudogap opens around $\sim$($\pi$, 0). 
M. Hashimoto, T. Yoshida, K. Tanaka, A. Fujimori, M. Okusawa, S.   Wakimoto, K. Yamada, T. Kakeshita, H. Eisaki, S. Uchida