Minutes of Survey All SM Higgs Production and Decay Processes Campaign meeting
February 13, 2014, 14:00 - 15:30
InDico: http://indico.cern.ch/event/297849/
Participants: ~10 (CERN) + ~30 (Vidyo)
1) Introduction (R. Tanaka)
-
LHC Higgs XS WG will be restructured to start from April 1st, 2014.
-
The aim of this meeting to survey all accessible SM Higgs production and decay at RUN-2, HL-LHC and beyond.
-
Tentative date for the 1st general meeting on June 12 (Thu.) - 13 (Fri.), 2014, when we can discuss the progress on this.
Discussions
=========
I. Main production processes [H, qqH, VH]
1) ggF
-
There could be a progress in N^3LO in near future.
-
Question was raised on approximate N^3LO (M. Spira), detailed answer by S. Forte who also explains how N^3LO PDFs are negligible for ggF.
-
Both arguments should be investigated in ggH subgroup asap.
-
Higgs pT studies for the 2HDM are in the starting/comparing phase in POWHEG in addition to MSSM. (A. Vicini)
2) VBF, WH/ZH
-
Hγ+2-jets could be an interesting channel to investigate among HV+2-jets category (V=γ,Z,W). (T. Figy)
-
VH+2jets (EW) is under study with MadGraph5_aMC@NLO. VH+2jets (QCD) is available MadGraph5_aMC@NLO. (F. Maltoni)
3) PDF
-
PDF4LHC new recommendation with arrival of many NNLO PDF sets?
-
A new one foreseeable next spring (J. Houston), but no decrease in the spread should be expected. (S.Forte)
-
Maybe top data (ex. rapidity distribution) will give some indication on which set is right/wrong.
-
A new WG for gg-PDFs is about to be created, and working on gg->Higgs PDF uncertainty through the Les Houches workshop. (J. Huston)
------
II. Associated Higgs production with heavy quarks [ttH/bbH/ccH]
1) ttH
-
NLO+PS is available since some time in POWHEL and aMC@NLO, and will be soon
also in SHERPA. (L. Reina)
-
EW could be done (M. Spira) but do not expect NNLO QCD, perhaps fragmentation picture could give insights on the way to build approximations.
-
Current major interest is ttbar+HF/V+jets, such as ttbb as backgrounds to ttH which are more urgent (L. Reina).
-
SM backgrounds calculations are more important than more higher-orders (M.Spira agreed).
2) bbH
-
Same comments as above in 4FS (M. Spira) while 5FS could eventually be done a la Anastasiou.
-
Plots with uncertainty should (probably) be redrawn (scale variation by 3).
-
bbH in 4FS is under study with MadGraph5_aMC@NLO. (F. Maltoni)
3) ccH
-
Numbers can be produced by SUSHI. (R. Harlander)
-
ccH in 3FS has large logs, which is more difficult than bbH. (M. Spira)
-> bbH and ccH can be discussed in MSSM subgroup.
------
III. Associated Higgs production with single top/bottom quark [tHq, WtH, btH, tH, bH, etc.]
-
bq->tHq' is the major channel which amounts to 14% of ttH at 14TeV and some interest in kF=+-1 case. (R. Tanaka)
-
tbH etc. are available via MadGraph5 in 4FS/5FS. (F. Maltoni)
-
tjH in 4FS/5FS are both available with MadGraph5_aMC@NLO. (F. Maltoni)
-
bH can be calculated in 4FS/5FS, but physically most interesting is in MSSM context at large tanβ.
-> These processes can be discussed in ttH/MSSM subgroups.
------
IV. Higgs boson pair/triple production [HH, qqHH, VHH, ttHH, tjHH, HHH]
1) HH
-
Very important channel for HH discovery in RUN-2 and beyond. (R. Tanaka)
-
gg->HH can be calculated/generated via HPAIR (M. Spira) and other processes via VBFNLO.
-
gg ->HH at NLO and NLO+PS improved by loop effects (including the real loops) is available with MadGraph5_aMC@NLO. (F. Maltoni)
-
NNLO gg->HH calculation exists by D. de Florian et al. (R. Tanaka)
-
The NNLO calculation is in the EFT and globally rescaled with the Born loop. (F. Maltoni)
-
Open question is what to learn from M. Steinhauser et al.(arXiv:1311.7425) on finite top quark mass effect.
2) qqHH (VBF)
-
NLO in total/differential in the VBFNLO framework, and public realeas of code soon. (J. Baglio)
-
NNLO calculation exists in the structure function approach, but no public code. (J. Baglio)
-
The NLO and NLO+PS obtained by MadGraph5_aMC@NLO are published and publicly available. (F. Maltoni)
3) ttHH
-
The NLO and NLO+PS obtained by MadGraph5_aMC@NLO are published and publicly available. (F. Maltoni)
4) tjHH
-
The NLO and NLO+PS obtained in the 5FS by MadGraph5_aMC@NLO are published and publicly available. (F. Maltoni)
5) HHH
-
Forget about HHH, as inaccessible for HL-LHC or even higher energies (J. Baglio).
-
Maybe at 100 TeV? -> paper by Yao...? (M. Spira) Energy does not help, only Lumi (M. Muehlleitner).
-> New HH subgroup being created. MadGraph5 plots are available, THU agreement is needed.
------
V. Higgs production in association with gauge bosons [VVH]
-
The NLO and NLO+PS obtained by MadGraph5_aMC@NLO are published and publicly available (F. Maltoni).
-> WH/ZH subgroup can cover this process.
------
VI. Higgs production in association with a gauge boson and two jets [qqHV]
-
Interesting channel as qq->HWqq amounts 2% of VBF and 5% of WH. interest for Yb measurement (D. Rainwater 2001).
-
The NLO and NLO+PS for HVjj (EW) can be tried with MadGraph5_aMC@NLO. (F. Maltoni).
-> VBF subgroup can cover this process.
------
VII. Gauge boson scattering [WW→WW, WW→HH, etc.]
-
Very important processes to probe the physics potential at very high-energy colliders. (R. Tanaka)
-
Can be studied via POWHEG VBF, VBF@NLO, MadGraph5_aMC@NLO, Phantom, etc.
-> VBF subgroup can cover this process.
------
VIII. Rare process and decay [qq→Hγ, t→cH, etc.] [quarkonia J/Ψ(Υ)+γ, γ/Z/W+P, etc.]
1) BR uncertainty
-
PU heavily depends on lattice input, ex. quark mass. (M. Spira)
-
Non-perturbative effects (ex. alpha_s) are neglected, expectations too optimistic? (M. Spira)
2) Rare decays
-
Probably only channels with photon (to replace Z in the listed channels in VP decays) might be visible.
-> To be followed up in BR subgroup for common framework for THU and PU.
------
Minutes taken by CGRS.
There are minutes attached to this event.
Show them.
