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

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6.3. Parameters 149• H¯qq ¯QQ: Ref. [109].These new analytic results have now been included in the MCFM package, version5.7 (which may be downloaded from mcfm.fnal.gov), leading to a considerableimprovement in the speed of the code. For the processes involving two quarkantiquarkpairs, the matrix elements squared given in Ref. [104] are implemented inMCFM, rather than the amplitudes of Ref. [109], because they lead to faster code.The values of the amplitudes calculated by the new analytic code and the previoussemi-numerical code [105] are in full numerical agreement for all amplitudes.The improvement in the performance of our numerical code means that it isappropriate to revisit the phenomenology of Higgs + 2 jet production and to extendit in a number of ways. The improvement in the speed of the code means that it ispossible to include the decays of the Higgs boson, specifically for the processes:h 1 + h 2 → H + j 1 + j 2 → τ + + τ − + j 1 + j 2 (6.5)h 1 + h 2 → H + j 1 + j 2 → b + ¯b + j 1 + j 2 (6.6)h 1 + h 2 → H + j 1 + j 2 → W − + W + + j 1 + j 2|| → ν + e+| → e − + ¯ν(6.7)h 1 + h 2 → H + j 1 + j 2 → Z + Z + j 1 + j 2|| → e − + e + (6.8)| → µ − + µ +where h 1 , h 2 represent partons inside the incident hadron beams. All four of theseprocesses are included in MCFM v5.7.6.3 ParametersThroughout this paper we make use of the MSTW2008 parton distribution functions[22], using the LO fit (α s (M Z ) = 0.13939 and 1-loop running) for the lowestorder calculation and the NLO fit (α s (M Z ) = 0.12018 and 2-loop running) at NLO.
6.4. Tevatron results 150The W mass and width are chosen to be,m W = 80.398 GeV, Γ W = 2.1054 GeV . (6.9)The mass is taken from Ref. [56]. The total width given in Eq. (6.9) is derived fromthe measured branching ratio for W → l¯ν, 10.80 ± 0.09% [56] by using a lowestorder calculation of the partial width,Γ(W → l¯ν) = G F√2m 2 W6π . (6.10)This ensures that our calculation incorporates the best possible value for the Wbranching ratio which is determined to about 1%. The values of the total Higgswidth are taken from the program hdecay [213], version 3.51.To define the jets we perform clustering according to the k T algorithm [32], withjet definitions detailed further below.6.4 Tevatron resultsWe use a very simple set of inclusive cuts, with no requirements on the Higgs bosondecay products,p t (jet) > 15 GeV, |η jet | < 2.5, R jet,jet > 0.4 . (6.11)At the Tevatron the search for the Higgs boson has been divided into jet bins.To set the stage for this we show in Table 6.1 the expected cross section in each bindue to the gluon fusion mechanism. The parameter µ is the renormalization andfactorization scale, which we set equal to m H here. We note that next-to-next-toleadingorder (NNLO) results for the Higgs + 0 jet cross section are given in [214],based on the earlier calculations in Refs. [78,79,81]. From table 6.1 columns 3 and5, we see that the Higgs + ≥ 2 jets bin constitutes about 13% of the cross sectionfor |η jet | < 2.5 and 11% with |η jet | < 2.It is interesting to compare the number for the fraction of Higgs + ≥ 2 jet events(|η jet | < 2) with the percentage extracted from Table 2 of [214], which is quoted
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Contentsvii1.4.1 Effective Lagrangi
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Contentsix4 One-loop Higgs plus fou
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ContentsxiB.2 Box Integral Function
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1.1. The Standard Model of Particle
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1.5. Higgs plus two jets: Its pheno
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2.1. Unitarity 32of two tree level
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2.2. Quadruple cuts 34the rational
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2.2. Quadruple cuts 360000000111111
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2.2. Quadruple cuts 38We now must s
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2.4. Spinor integration 46Here we h
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2.6. The unitarity-bootstrap 56Next
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2.6. The unitarity-bootstrap 58Figu
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2.6. The unitarity-bootstrap 62rati
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2.9. Summary 68cluding the recent c
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Page 145 and 146: 4.6. Summary 130p µ 2 = (+0.344450
Page 147 and 148: Chapter 5The φqqgg- NMHV amplitude
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Page 151 and 152: 5.1. Introduction 136H amplitude φ
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Page 157 and 158: 5.2. One-loop results 142Relation f
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Page 161 and 162: 5.4. Summary 146(φ, 1 −¯q , 2 +
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Page 175 and 176: 6.5. LHC results 160of describing T
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Page 185 and 186: Appendix ASpinor Helicity Formalism
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Page 189 and 190: A.3. Pure QCD amplitudes 174Further
Page 191 and 192: Appendix BOne-loop Basis IntegralsI
Page 193 and 194: B.2. Box Integral Functions 178boxe
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Page 197 and 198: Bibliography 182[10] R. Feynman, Ma
Page 199 and 200: Bibliography 184[36] M. Bahr et. al
Page 201 and 202: Bibliography 186[63] M. Shifman, A.
Page 203 and 204: Bibliography 188[85] R. V. Harlande
Page 205 and 206: Bibliography 190[104] R. K. Ellis,
Page 207 and 208: Bibliography 192[125] G. Ossola, C.
Page 209 and 210: Bibliography 194[148] R. Boels and
Page 211 and 212: Bibliography 196[170] Z. Bern and A
Page 213 and 214: Bibliography 198anti-t + 2 jets at
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Bibliography 200[214] C. Anastasiou
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