  For the past six years we have carried out a search for massive planets
around main sequence and evolved stars in the open cluster (OC) M67, using
radial velocity (RV) measurements obtained with HARPS at ESO (La Silla), SOPHIE
at OHP and HRS at HET. Additional RV data come from CORALIE at the Euler Swiss
Telescope. We aim to perform a long-term study on giant planet formation in
open clusters and determine how it depends on stellar mass and chemical
composition.
  We report the detection of three new extrasolar planets: two in orbit around
the two G dwarfs YBP1194 and YBP1514, and one around the evolved star S364. The
orbital solution for YBP1194 yields a period of 6.9 days, an eccentricity of
0.24, and a minimum mass of 0.34 Mj. YBP1514 shows periodic RV variations of
5.1 days, a minimum mass of 0.40 Mj, and an eccentricity of 0.39. The best
Keplerian solution for S364 yields a period of 121.7 days, an eccentricity of
0.35 and a minimum mass of 1.54 Mj. An analysis of H_alpha core flux
measurements as well as of the line bisectors spans revealed no correlation
with the RV periods, indicating that the RV variations are best explained by
the presence of a planetary companion. Remarkably, YBP1194 is one of the best
solar twins identified so far, and YBP1194b is the first planet found around a
solar twin that belongs to a stellar cluster. In contrast with early reports
and in agreement with recent findings, our results show that massive planets
around stars of open clusters are as frequent as those around field stars.
