Precision calculations for collider processes Gudrun Heinrich Max Planck Institute for Physics, Munich

Transcription

1 Precision calculations for collider processes Gudrun Heinrich Max Planck Institute for Physics, Munich Scientific Board Meeting July 27, 2016

2 Overview tools FeynArts/FormCalc, Cuba GoSam SecDec NLO phenomenology Standard Model BSM two-loop calculations two-loop amplitude for Higgs boson pair production NNLO QCD corrections to dijet production at hadron colliders [J.Pires] public program for e+e- to 3 jets at NNLO [not covered here] two-loop corrections to the Higgs boson mass in the MSSM [covered by W.Hollik]

3 Thomas Hahn programs which expect keyboard input can be evoked directly from the shell

4 publicly available at open source amplitude generation on the fly example input file for e + e! t t NLO automation: GoSam program package for the automated calculation of one-loop multi-leg amplitudes Cullen, van Deurzen, Greiner, GH, Jahn, Luisoni, Mastrolia, Mirabella, Ossola, Peraro, Schlenk, Scyboz, von Soden-Fraunhofen, Tramontano

5 NLO automation graphics by G.Luisoni, E.Mirabella

6 Interface to Monte Carlo programs Binoth-Les-Houches-Accord (BLHA) standards extended [CPC 185 (2014)] important BLHA2 feature important BLHA2 feature combination of GoSam with the Monte Carlo programs Sherpa, Powheg, Herwig7, MadGraph (GoSam by default included in Herwig7 distribution)

7 Examples of processes calculated with GoSam GoSam + MadDipole/MadGraph/MadEvent pp! (G! )+1jet pp! +1, 2 jets pp! HH +2jets GoSam + Sherpa pp! W + W b b pp! t t +0, 1 jet pp! Ht t +0, 1 jet pp! top philic resonance [Greiner, Kong, J.Park, S.Park, Winter 15] pp! H +3jets [Cullen, v.deurzen, Greiner, Höche, Luisoni, Mastrolia, Mirabella, Ossola, Peraro, GoSam + Powheg Schönherr, Tramontano, Winter, Yundin 13, 15] pp! HW/HZ +0, 1 jet [Luisoni, Nason, Oleari, Tramontano '13] GoSam + Herwig7 GoSam + MadGraph5_aMC@NLO [Greiner, GH, Reichel, von Soden-Fraunhofen '13] [Gehrmann, Greiner, GH '13] [Dolan, Englert, Greiner, Spannowsky 13, 15] pp! W +2jets (EW corrections) [Chiesa, Greiner, Tramontano 15] pp! Wb b +0, 1 jet pp! W + W pp! t t +EFT [GH, Maier, Nisius, Schlenk, Winter '13] [Höche, Huang, Luisoni, Schönherr, Winter '13] [van Deurzen, Luisoni, Mastrolia, Mirabella, Ossola, Peraro '13] [Luisoni, Oleari, Tramontano '15] [Bellm, Gieseke, Greiner, GH, Plätzer, Reuschle, von Soden-Fraunhofen 16] [van Deurzen, Frederix, Hirschi, Luisoni, Mastrolia, Ossola '15]

8 Examples of processes calculated with GoSam GoSam + MadDipole/MadGraph/MadEvent pp! (G! )+1jet pp! +1, 2 jets pp! HH +2jets GoSam + Sherpa pp! W + W b b pp! t t +0, 1 jet pp! Ht t +0, 1 jet pp! top philic resonance [Greiner, Kong, J.Park, S.Park, Winter 15] pp! H +3jets [Cullen, v.deurzen, Greiner, Höche, Luisoni, Mastrolia, Mirabella, Ossola, Peraro, GoSam + Powheg Schönherr, Tramontano, Winter, Yundin 13, 15] pp! HW/HZ +0, 1 jet [Luisoni, Nason, Oleari, Tramontano '13] GoSam + Herwig7 GoSam + MadGraph5_aMC@NLO [Greiner, GH, Reichel, von Soden-Fraunhofen '13] [Gehrmann, Greiner, GH '13] [Dolan, Englert, Greiner, Spannowsky 13, 15] pp! W +2jets (EW corrections) [Chiesa, Greiner, Tramontano 15] pp! Wb b +0, 1 jet pp! W + W pp! t t +EFT [GH, Maier, Nisius, Schlenk, Winter '13] [Höche, Huang, Luisoni, Schönherr, Winter '13] [van Deurzen, Luisoni, Mastrolia, Mirabella, Ossola, Peraro '13] [Luisoni, Oleari, Tramontano '15] [Bellm, Gieseke, Greiner, GH, Plätzer, Reuschle, von Soden-Fraunhofen 16] [van Deurzen, Frederix, Hirschi, Luisoni, Mastrolia, Ossola '15]

9 Higgs + 3 jets at NLO [Cullen, v.deurzen, Greiner, Höche, Luisoni, Mastrolia, Mirabella, Ossola, Peraro, Schönherr, Tramontano, Winter, Yundin 13, 15] effective gluon-higgs boson couplings ( ) need higher rank integrals) detailed phenomenological study scale choices:

10 Higgs + 3 jets at NLO [Cullen, v.deurzen, Greiner, Höche, Luisoni, Mastrolia, Mirabella, Ossola, Peraro, Schönherr, Tramontano, Winter, Yundin 13, 15] effective gluon-higgs boson couplings ( ) need higher rank integrals) detailed phenomenological study results available in form of Root N-tuples, used by ATLAS scale choices:

11 Anomalous gluon - vector boson couplings [Bellm, Gieseke, Greiner, GH, Plätzer, Reuschle, von Soden-Fraunhofen 16] include effective operators which mediate direct coupling of gluons to W-bosons combine with full NLO corrections to pp! W + W include parton shower (Herwig7), top- and b-quark masses in the loops study SM versus BSM effects

12 Anomalous gluon - vector boson couplings [Bellm, Gieseke, Greiner, GH, Plätzer, Reuschle, von Soden-Fraunhofen 16]

13 beyond one loop

14 Numerical evaluation of multi-loop integrals contour deformation algorithm: T. Binoth, GH 00 version 1.0: version 2.0: S.Borowka, J. Carter, GH 12 version 3.0: J. Carter, GH 10 S.Borowka, GH, S.Jones, M.Kerner, J.Schlenk, T.Zirke 15

15 SecDec basic workflow graphics by S.Borowka optionally on a cluster uses CUBA library [ T.Hahn ]

16 SecDec development SecDec so far has been mainly used to check analytically calculated integrals important new step: use SecDec like a library to evaluate analytically unknown integrals within the calculation of two-loop amplitudes

17 SecDec development SecDec so far has been mainly used to check analytically calculated integrals important new step: use SecDec like a library to evaluate analytically unknown integrals within the calculation of two-loop amplitudes pysecdec: algebraic part in form of python modules S. Jahn, S. Jones, T. Zirke et al. coming soon

18 automated 2-loop amplitudes: 2 loops process definition projectors to form factors gosam.py process.rc integral families create QGRAF files create python,form files create Reduze files diagram pictures run Qgraf, FORM,python run Reduze create amplitude files create SecDec files numerical integration two-loop amplitude

19 other SecDec applications

20 SecDec applications beyond QCD

21 SecDec applications beyond QCD

22 precision Higgs physics Higgs boson self-coupling still largely unconstrained can be measured in Higgs boson pair production

23 Higgs boson pair production at NLO S.Borowka, N.Greiner, GH, S.Jones, M.Kerner, J.Schlenk, U.Schubert, T.Zirke 16 gg! HH : Leading Order already involves 1-loop diagrams g H t NLO (= 2 loops) g H 4 independent scales s12, s23, mh, mt graphics by S.Jones

24 Higgs boson pair production at NLO S.Borowka, N.Greiner, GH, S.Jones, M.Kerner, J.Schlenk, U.Schubert, T.Zirke 16 gg! HH : Leading Order already involves 1-loop diagrams g H t NLO (= 2 loops) g H 4 independent scales s12, s23, mh, mt graphics by S.Jones (most) 2-loop diagrams not known analytically with full mass dependence

25 previous results in the literature LO with full heavy quark mass dependence Glover, van der Bij 88, Plehn, Spira, Zerwas 96 NLO in m t!1 limit (HEFT): Dawson, Dittmaier, Spira 98 (HPAIR) supplemented with Grigo, Hoff, Melnikov, Steinhauser 13, 15 ; full mass dependence in NLO real radiation part and matching to parton shower Frederix, Hirschi, Mattelaer, Maltoni, Torrielli, Vryonidou, Zaro 14; Maltoni, Vryonidou, Zaro 14 NNLO in m t!1 limit: 1/m t expansion: (±10%) De Florian, Mazzitelli 13; De Florian, Grazzini, Hanga, Kallweit, Lindert, Maierhöfer, Mazzutelli, Rathlev 16 including all matching coefficients Grigo, Melnikov, Steinhauser 14 1/m t soft gluon resummation NNLL matched to NNLO De Florian, Mazzitelli 15 + lots of phenomenological studies Degrassi, Giardino, Gröber 16-10% +20% supplemented with expansion: Grigo, Hoff, Steinhauser 15 Baglio, Barr, Contino, Dawson, Dolan, Englert, Ferreira de Lima, Furlan, Goncalves-Netto, Greiner, Gröber, Krauss, Lewis, Maierhöfer, Maltoni, Mühlleitner, Papaefstathiou, Spannowsky, Spira,Thompson, Vryonidou, Zaro, Zurita,...

26 previous results in the literature LO with full heavy quark mass dependence Glover, van der Bij 88, Plehn, Spira, Zerwas 96 NLO in m t!1 limit (HEFT): Dawson, Dittmaier, Spira 98 (HPAIR) supplemented with Grigo, Hoff, Melnikov, Steinhauser 13, 15 ; full mass dependence in NLO real radiation part and matching to parton shower Frederix, Hirschi, Mattelaer, Maltoni, Torrielli, Vryonidou, Zaro 14; Maltoni, Vryonidou, Zaro 14 NNLO in m t!1 limit: 1/m t expansion: (±10%) De Florian, Mazzitelli 13; De Florian, Grazzini, Hanga, Kallweit, Lindert, Maierhöfer, Mazzutelli, Rathlev 16 including all matching coefficients Grigo, Melnikov, Steinhauser 14 1/m t soft gluon resummation NNLL matched to NNLO De Florian, Mazzitelli 15 + lots of phenomenological studies Degrassi, Giardino, Gröber 16-10% +20% supplemented with expansion: Grigo, Hoff, Steinhauser 15 main uncertainty was due to unknown top mass effects Baglio, Barr, Contino, Dawson, Dolan, Englert, Ferreira de Lima, Furlan, Goncalves-Netto, Greiner, Gröber, Krauss, Lewis, Maierhöfer, Maltoni, Mühlleitner, Papaefstathiou, Spannowsky, Spira,Thompson, Vryonidou, Zaro, Zurita,...

27 gg to HH with full top quark mass dependence S. Borowka, N. Greiner, G. Heinrich, S. P. Jones, M. Kerner, J. Schlenk, U. Schubert, T. Zirke Phys. Rev. Lett. 117, (2016) unique combination of tools and expertise g t H all integrals calculated numerically with SecDec g H total number of integrals after decomposition 11244, 3086 non-planar integration with quasi Monte Carlo method [Dick, Kuo, Sloan 13] parallelisation on GPU [Li, Wang, Yan, Zhao 15] number of sampling points dynamically set for each integral target accuracy set at amplitude level

28 resources

29 top mass effects d /d mhh [fb/gev] K factor LO NLO HEFT NLO FT approx NLO p s = 13 TeV m h =125 GeV m t central scale m hh /2 =173 GeV FTapprox: full mtop dependence in real radiation part only d /d mhh [fb/gev] m hh [GeV] p s = 14 TeV LO, =1 NLO, =1 LO, =0 NLO, =0 LO, =2 NLO, =2 LO, =3 NLO, = m hh [GeV] d /d mhh [fb/gev] K factor LO NLOFTapprox NLO p s = 100 TeV m hh [GeV]

30 Summary and Outlook the tools developed in the phenomenology group have found many successful applications within the group in the particle physics community numerous phenomenological results, used by experimental collaborations new combination of tools and (numerical) methods which allowed calculation of gg! HH two-loop amplitudes with full opens the door to precision calculations which seemed unfeasible until recently m t dependence

31 BACKUP SLIDES

32 sector decomposition x (1) x t 1 + (2) + y t 1 y algorithmic procedure to factorise end-point singularities

33 Higgs + 2 jets at NLO

34 e+e- to 3 jets at NNLO

35 examples of integrals contributing to Higgs boson pair production at NLO graphics by Stephen Jones