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Hadronic production of a Higgs boson in association with two jets at ...

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4.2. Cut-Constructible Contributions 122φ1φ1φ122 43C 2;φ 4 4 C32;φ4 3 C 2;φ342(a) (b) (c)Figure 4.3: The three bubble <strong>in</strong>tegral topologies th<strong>at</strong> appear for A (1)4 (φ, 1, 2, 3, 4).We must also <strong>in</strong>clude cyclic permut<strong>at</strong>ions <strong>of</strong> the four gluons.The lead<strong>in</strong>g s<strong>in</strong>gularity <strong>of</strong> the bubble <strong>in</strong>tegral is O(1/ǫ),( )1 µ2 ǫI 2 (s) ∝. (4.24)(1 − 2ǫ)ǫ −sHowever for the total amplitude there is no overall ǫ pole, and this implies a rel<strong>at</strong>ionamongst the bubble coefficients such th<strong>at</strong>,4∑(C 2;φk + C 2;φkk+1 ) = 0. (4.25)k=1It is therefore most n<strong>at</strong>ural to work <strong>with</strong> log’s <strong>of</strong> r<strong>at</strong>ios <strong>of</strong> k<strong>in</strong>em<strong>at</strong>ic scales (r<strong>at</strong>herthan log(s/µ 2 )), s<strong>in</strong>ce the coefficients <strong>of</strong> <strong>in</strong>dividual logarithms must cancel pairwise.To this end, as <strong>in</strong> the last chapter, we express our result <strong>in</strong> terms <strong>of</strong> the follow<strong>in</strong>gfunctions,L k (s, t) =log (s/t)(s − t) k . (4.26)Us<strong>in</strong>g the Stokes’ theorem method [132], we gener<strong>at</strong>ed compact analytic expressionsfor the coefficients <strong>of</strong> each bubble-function, which we also checked numerically <strong>with</strong>Forde’s method [122]. The comb<strong>in</strong><strong>at</strong>ion <strong>of</strong> all double-cuts is given by,(C 2 (φ, 1 + , 2 − , 3 − , 4 − ) = 4 − N ) (fC (1)2 + 1 − N )fC (2)2 (4.27)NN c<strong>with</strong>{C (1) 〈24〉〈3|pφ |1] 22 = − L 1 (s 124 , s 12 ) − 〈23〉〈4|p } { }φ|1] 2L 1 (s 123 , s 12 ) − (2 ↔ 4)s 124 [42]s 123 [32](4.28)

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