Algebras with involution that become hyperbolic over the fonction field   of a conic
  We study central simple algebras with involution of the first kind that become hyperbolic over the function field of the conic associated to a given quaternion algebra $Q$. We classify these algebras in degree~4 and give an example of such a division algebra with orthogonal involution of degree~8 that does not contain $Q$ with its canonical involution, even though it contains $Q$ and is totally decomposable into a tensor product of quaternion algebras with involution. 
Anne Qu\'eguiner-Mathieu (LAGA), Jean-Pierre Tignol