SM Higgs Theory Robert Harlander Bergische Universität Wuppertal SM@LHC, GGI, Florence, 21 April 2015 supported by

see talk by D. Rathlev (Wed 11.15am) Backgrounds huge progress at NLO due to automatic tools: Sherpa+OpenLoops HELAC-NLO MadGraph5+aMC@NLO POWHEG-Box, GoSam, Recola, MCFM, Herwig, Pythia, ... many NNLO and/or EW calculations: WW, ZZ, ϒϒ, Zϒ, ttbar, ... see talk by D. Rathlev (Wed 11.15am)

precision physics is coming back!

Towards N3LO: Baikov, Chetyrkin, Smirnov, Smirnov, Steinhauser ’09 Lee, Smirnov, Smirnov ’10 Gehrmann, Glover, Huber, Ikizlerli, Studerus ’09 Hoschele, Hoff, Pak, Steinhauser, Ueda ’12 Anastasiou, Bühler, Duhr, Herzog ’12 O(ε) + Herzog ’13 Anastasiou, Duhr, Dulat, Mistlberger ’13 Boughezal, Caola, Melnikov, Petriello, Schulze ’13

Soft expansion: expansion around

2 lowest order terms in ambiguity: Anastasiou, Duhr, Dulat, Furlan, Gehrmann, Herzog, Mistlberger ’13 generalization of soft N3LO to pp→Xcolor singlet Ahmed, Mahakhud, Rana, Ravindran ’14 Catani, Cieri, de Florian, Ferrera, Grazzini ’14 ambiguity:

Anastasiou, Duhr, Dulat, Mistlberger ’15 30 terms: RH, Kilgore ’02 Anastasiou, Duhr, Dulat, Mistlberger ’15

Anastasiou, Duhr, Dulat, Mistlberger ’15

+ N3LO

perturbative effects under control soft resummation relevant? Consequence: perturbative effects under control soft resummation relevant? need to control other effects: bottom loops/Yukawa coupling? mb(MH) = 2.7 GeV mbpole = 4.7 GeV PDFs electro-weak effects mass effects at NNLO

pT distribution

Consider extreme case: Higgs does not couple to top quark gluon-Higgs coupling mediated by Λ >> MH measurement of total cross section ⇒ at least one of the Cn must be large! expect very different pT spectrum RH, Neumann ’13 Banfi, Martin, Sanz ’14 Azatov, Paul ’14 see also: Grojean, Salvioni, Schlaffer, Weiler ’14

pT-shape for higher operators: RH, Neumann ’13 NLO: Dawson, Lewis, Zeng ’14

pT distribution consider gluon fusion: p1+p2=q NLO: non-zero Higgs-pT requires emission of gluon

1/mt effects RH, Neumann, Wiesemann ’12 Neumann, Wiesemann ’14

threshold ŝ>(2mt)2 ŝ<(2mt)2

threshold [Marzani et al ’08]

(σ = φ⊗φ⊗σ) ˆ threshold

exact

RH, Mantler, Marzani, Ozeren ’09 Pak, Rogal, Steinhauser ’09

inclusive H+jet: NLO LO Neumann, Wiesemann ’14

Small pT ln(pT/Q) → ∞ Q∼mH requires resummation HqT Bozzi, Catani, de Florian, Grazzini ’03 Becher, Neubert, Wilhelm’11 de Florian, Kulesza, Vogelsang ’06 Kulesza, Sterman, Vogelsang ’03 Berger, Qiu ’03 see also: ...

→ bottom loop effects: resummation based on collinear factorization: pT « Q → ⊗ P + Q = ?

Banfi, Monni, Zanderighi ’13 jet vetoed Banfi, Monni, Zanderighi ’13 Mantler, Wiesemann ’12 Bagnaschi, Degrassi, Slavich, Vicini ’11 POWHEG Hamilton, Nason, Zanderighi ’15 NNLOPS vs. + Grazzini, Sargsyan ’13

unitarity constraint: Bozzi, Catani, de Florian, Grazzini ‘14 unitarity constraint: may lead to dσ/dpT ≠ dσ/dpT|fixed order at large pT RH, Mantler, Wiesemann ’14 use as prescription to determine Q!

produced with MoRe-SusHi

Conclusion on pt distribution: 1/mt effects desirable at large pT final understanding of bottom effects still missing detailed comparison of all approaches required may become very important in extended theories

Higgs Strahlung:

vs. Englert, McCullough, Spannowsky ’13 see also: Hespel, Maltoni, Vryonidou ’15

distribution of “fat jet” (see Butterworth et al. ’08): NNLO Ferrera, Grazzini, Tramontano ’14 +

threshold resummation: at NLO: NLO+NLL: RH, Kulesza, Theeuwes, Zirke threshold resummation: NLO: Altenkamp, Dittmaier, RH, Rzehak, Zirke ’12

consider ratio: σWH/σZH very weak dependence on PDFs very weak dependence on αS reduced experimental uncertainties RH, Liebler, Zirke ’13 see also: Englert, McCullough, Spannowsky ’13 Hespel, Maltoni, Vryonidou ’15

2HDM: RH, Liebler, Zirke ’13 see also: Englert, McCullough, Spannowsky ’13 Hespel, Maltoni, Vryonidou ’15

... back to SM there is still hope: mh2 = 2λv2 ?

Frederix et al. ’14 see also: Baglio et al. ’13

effective theory for mt→∞ higher orders? effective theory for mt→∞ → NLO: Dawson, Dittmaier, Spira ’95 NNLO: de Florian, Mazzitelli ’13 Grigo, Melnikov, Steinhauser ’14 1/mt effects? “like for gg→H”: caution!

effective theory expected to work gg→HH gg→H

Grigo, Hoff, Melnikov, Steinhauser ’13

full NLO calculation desirable... real emission exact virtual=EFT rescaled by Born Maltoni, Vryonidou, Zaro ’14 full NLO calculation desirable...

Off-shell / interference

Off-shell / interference off-shell production: handle on Higgs width off-shell Caola, Melnikov ’13 on-shell see also Passarino, Kauer ’12, Campbell, Ellis, Williams ’13, ... radiative corrections? see talk by N. Kauer (Wed, 9am)

Off-shell / interference signal / background interference: mass shift S.P. Martin ’12 de Florian et al. ’13 γ γ

Lots of things I could not talk about: pp→VH→VVV @ NLO+PS pp→WH→Vbb @ NNLO ttbb signal/background interference single top + Higgs analysis methods ... Hoeche et al. ’14 Ferrera, Grazzini, Tramontano ’14 Denner, Feger, Scharf ’14 Demartin, Maltoni, Mawatari, Zaro ’15 e.g. Perez, Soreq, Stamou, Tobioka ’15 ... apologies!

Conclusions theory progress unbroken will continue, no matter what, because: precision physics is gradually coming back many issues require a second glance “only Higgs” scenario disappointing ... but good for technology!

full MSSM @ NLO SM @ NNLO 2HDM NMSSM bbh various ren. schemes New! link to FeynHiggs link to LHAPDF link to 2HDMC ... RH, Liebler, Mantler ’12 Liebler ’15 New!