Context : There are competing scenarii for planetary systems formation and evolution trying to explain how hot Jupiters came to be so close to their parent star .
Most planetary parameters evolve with time , making distinction between models hard to do .
It is thought the obliquity of an orbit with respect to the stellar rotation is more stable than other parameters such as eccentricity .
Most planets , to date , appear aligned with the stellar rotation axis ; the few misaligned planets so far detected are massive ( > 2 M _ { \mathrm { J } } ) .

Aims : Our goal is to measure the degree of alignment between planetary orbits and stellar spin axes , to detect potential correlation with eccentricity or other planetary parameters and to measure long term radial velocity variability indicating the presence of other bodies in the system .

Methods : For transiting planets , the Rossiter-McLaughlin effect allows the measurement of the sky-projected angle \beta between the stellar rotation axis and a planet ’ s orbital axis .
Using the HARPS spectrograph , we observed the Rossiter-McLaughlin effect for six transiting hot Jupiters found by the WASP consortium .
We combine these with long term radial velocity measurements obtained with CORALIE .
We used a combined analysis of photometry and radial velocities , fitting models with a Markov Chain Monte Carlo .
After obtaining \beta we attempt to statistically determine the distribution of the real spin-orbit angle \psi .

Results : We found that three of our targets have \beta above 90 ^ { \circ } : WASP-2b : \beta = 153 ^ { \circ +11 } _ { -15 } , WASP-15b : \beta = 139.6 ^ { \circ +5.2 } _ { -4.3 } and WASP-17b : \beta = 148.5 ^ { \circ +5.1 } _ { -4.2 } ; the other three ( WASP-4b , WASP-5b and WASP-18b ) have angles compatible with 0 ^ { \circ } .
There is no dependence between the misaligned angle and planet mass nor with any other planetary parameter .
All orbits are close to circular , with only one firm detection of eccentricity on WASP-18b with e = 0.00848 ^ { +0.00085 } _ { -0.00095 } .
No long term radial acceleration was detected for any of the targets .
Combining all previous 20 measurements of \beta and our six and transforming them into a distribution of \psi we find that between about 45 and 85 \% of hot Jupiters have \psi > 30 ^ { \circ } .

Conclusions : Most hot Jupiters are misaligned , with a large variety of spin-orbit angles .
We find observations and predictions using the Kozai mechanism match well .
If these observational facts are confirmed in the future , we may then conclude that most hot Jupiters are formed from a dynamical and tidal origin without the necessity to use type I or II migration .
At present , standard disc migration can not explain the observations without invoking at least another additional process .