Top-Antitop Production at Hadron Colliders

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Top-Antitop Production at Hadron Colliders

Two-Loop Corrections to q¯q → t¯t

|M| 2 (s, t, m, ε) = 4π2 α 2 » “

s αs

” “ αs

” 2

A 0 + A 1 + A2 + O `αs´–

3

N c π π

A 2 = A (2×0)

2

+ A (1×1)

2

A (2×0)

2

= N c C F

h

N 2 c A + B + C N 2 c

+ N l


N c D l + E l

N c

«


+N h N c D h + E «

h

+ Nl 2 N F l + N l N h F lh + Nh 2 F h

c

i

218 two-loop diagrams contribute to the 10 different color coefficients

The whole A (2×0)

2

is known numerically

Czakon ’08.

HP2.3rd GGI-Florence, September 15, 2010 – p.16/25

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