== ---+ Experimental tests of the spin of the top quark ==

==== 1. ====

Compute analytically the partonic cross sections for $q \bar q \to t \bar t$ and $g g \to t \bar t$ for t spin 1/2 and spin 0 at the tree level. Check your results against the LO results available in the literature:









with



==== 2. ====

Consider the behaviour at threshold and also the relative sizes of the cross sections for corresponding masses.

==== 3. ====

Use any MC at tree level to calculate the cross sections for tops and stops at the Tevatron and the LHC. Make plots of the distributions and in particular of $m_tt$.

==== 4. ====

Compare your findings with [http://arxiv.org/abs/hep-ph/0002305 Top Spin and experimental tests], by Ed Berger and Tim Tait.

-- Main.FabioMaltoni - 03 Dec 2008