Higgs+jets: data vs theory

Joey HustonBruce Mellado

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Higgs(->gg)+jets Most of the excess observed

for Higgs production is in >=1 jet final states

Maybe CMS does not see as large of an excess

In any case, we would like to use the best theory we can to understand the level of excess

For inclusive Higgs production through gg fusion, we use a NNLO+NNLL calculation which means a NLO

calculation for Higgs + 1 jet

and a LO calculation for Higgs + 2 jets

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NNNLO inclusive gg->Higgs cross section is not very convergent So it’s appropriate to think about effects of still higher order corrections Approximate NNNLO corrections have been carried out resumming the

effects of soft gluon radiation; recently BFKL logs have been resummed as well, leading to more scale stability and an additional increase in the cross section

This increase should bepassed on to the 1 and 2jet cross sections as well

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Higgs+1 jet at NLO …from Dec. 20 meeting NLO cross section has a LO-like scale dependence

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Higgs+1 jet at NNLO So the NNLO correction for

Higgs+1 jet (through gg fusion) is about 30%

gg corresponds to about 65% of the cross section; they are working on other initial states and it is probable that the NNLO corrections for the other initial states (gq) will be somewhat smaller (maybe 1.15 instead of 1.30)

σNLO/σLO = 1.6σNNLO/σNLO = 1.3

arXiv:1302.6216

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Higgs+jets (binned cross sections)

resummation for Higgs + 0 jetand for Higgs + 1 jet has leadto sizeable reduction in scaleuncertainty for exclusive Higgs+0,1 jet production

we need to revisit the formulation of the uncertainties for binned jet Higgs crosssections

this is a task for Snowmass/Les Houches

also investigate jet veto effects for higherenergy accelerators

Xiaohui Liu

What about Higgs+>=2 jet final states?

We know Higgs+2 jets to NLO A NNLO calculation of Higgs+2 jets is a long way off, but by general

arguments we might expect the size of the NNLO corrections to be <= that seen for Higgs+1 jet

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Sherpa+… One of the best vehicles to

estimate contributions to the different jet multiplicities may be Sherpa(+gosam/MCFM/blackhat)

At least it’s the one I’m currently using

One can include Higgs+0,1 and 2 jets at NLO, up to 3 additional jets at LO, with extra jets from parton showers, looking at the effects of varying the merging scale, the renormalization scale, the factorization scale and the resummation scale with maybe some motivated

re-weighting based on the new theory predictions

I have Higgs+1 jet (at NLO) working now, and should have Higgs+2 jets in the next few days

The same thing can be done for W+jets, so this may be a useful cross-check in a channel where the statistics are much higher and the physics perhaps better understood

We know we see an excess It may be a fluctuation, we would

like to understand the theory predictions and their uncertainties.

2nd jetreceives substantialcontributionsfrom 3-jetmatrix element

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