Gg initial states (Higgs, with NLM Higgs)

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gg> H + jets study

People so far :

  • P. Skands,
  • F. Maltoni,
  • M. Mangano, Alpgen matched with PS
  • S. de Visscher, MG/ME matched with PS
  • J. Andersen, HE approach
  • J. Winter, S. Hoeche, SHERPA
  • K. Hamilton, HERWIG++ (+POWHEG)

Parameters/plots of the study number 1: Inclusive Higgs

  • CTEQ6M for NLO and NNLO results
  • CTEQ6L1 for LO results
  • 5 Flavours in the initial state
  • pp @ LHC10, mh=120
  • jet-algorithm : kt with D=0.7, E-scheme (fastjet implementation from here)
  • Matched samples plots to be done after showering/before hadronization


  • For the Higgs-effective coupling let's use the notation of [[1]] with tau=0, with a fixed value of alpha_S=0.120

0. Format : x y dy (dy is just a placeholder for some kind of content bins should be dropped).

1. Jet rates (from zero jets to 4 or 5 jets) (Pt>20, |eta|<4.5).

2. Pt (pt) and and pseudo-rapidity (eta) of the Higgs:

      pt in [0:250] GeV bins of 10  GeV
      pt in [0:50] GeV bins of 2  GeV
      eta in [-5.25 : 5.25] bins of 0.5 

3. pt jets and eta of jets and deltaR(i,j):

      1st  j pt [0:250] GeV  bins of 10 GeV
      2nd  j pt [0:150] GeV  bins of 10 GeV
      3rd  j pt [0:100] GeV  bins of 10 GeV
      4rd  j pt [0:100] GeV  bins of 10 GeV
      nth  j eta [-5.25:5.25] in bins of 0.5
      Delta12,23,34 in [0,5] in bins of 0.2

1. Ht_red and Ht

     a. Sum of pt_jets (no higgs) in [0:500] bins of 10 GeV
     b. Sum of pt_jets + pt higgs in [0:500] bins of 10 GeV

Parameters/plots of the study number 2: Higgs + dijet

Jeppe and Stefan to fill this.

[FM: I want to mention that it would be probably interesting to have also MCFM numbers here for H+2jet at NLO. Maybe we should ask Giulia....

Jeppe: It certainly would be, but is currently not possible. hjj@NLO was never implemented in MCFM since the virtual corrections were evaluated using a (semi-)numerical method, which turned out to be too slow. John Campbell is currently working on implementing the recently calculated analytic form for the virtual currections]

Jet-algo: kt with D=0.7, min jet pt:40GeV, |y_j|<4.5
Require at least two jets
Higgs: |y_h|<4.5

1. Average number of hard jets and tagjet azimuthal decorrelation vs. rapidity span (Delta y_{ja jb} is rapidity difference between the most forward/backward hard jet)

  <N_jet> vs Delta y_{ja jb} [0:8] in bins of 0.2 units of rapidity
  <cos(Pi-DeltaPhi)> vs Delta y_{ja jb} [0:8] in bins of 0.2

The remaining studies require also

Delta y_{ja jb}>4., where jb is the backward and ja is the forward hard jet

2. Rapidity distribution of most forward/backward hard jet, and of hardest (in pt) and next-to-hardest jet.

3. Transverse momentum distribution for the Higgs boson

  pt in [0:250] GeV bins of 10  GeV

4. Effects of central rapidity jet veto (a la Fig. 23 in arXiv:0808.3696, same binning i.e. [0:4] in 0.1 in y_c)

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