Welcome to the  MET web page
The conveners of the group are :  Patrice Verdier and Sophie Trincaz Duvoid

 

 

Link to the old Jet/Met page

Presentations at CALGO meetings

6 oct 03     : MET status
21 oct 03   : MissingET corrections
18 nov 03  : Status of MET certification
3 dec 03    : MET Certification
3 dec 03    : MET and d0correct
 

MET Certification on p14
334 runs studied between 178309 and 180956
47490 lumi blocks =>  106.9  Mevts (52.6 pb-1)
• In the « official» Physics Runs database ? 337 runs  listed                                (http://www-d0.fnal.gov/runcoor/d0_private/operations/stores_runs.html)
    • 326 in common
    • 11 are in the db but are zeroB or not in tmb
24 runs are excluded because flagged bad by Slava or after reading the logbook
(43698 lumi blocks / 98.0 Mevts / 48.5 pb-1)

• Studies done at cc-in2p3 on thumbnails

Run selection
For each run we run on all events and get the mean values and RMS of METBx, METBy,SETB and MET-T42x, MET-T42y,SET-T42 distributions.

Definitions :
METB = MET computed with cells not belonging to the CH (Ecell>0, layer<15) and with the CH fraction of JCCB jets.
MET-T42 = METC (Ecell>0) – T42 cells
Variables computed with mean values of distributions of all events in a run.

Cuts
SHIFT-metbxy < 4 GeV
RMS-metbxy   < 22 GeV
Mean-setb       > 80 GeV
Nevts > 1000

We keep 276 runs =>  88.7 %  (92.7 % of lumi blk and 92.9  % of events)
 But still large fluctuations of <METBx> and <METBy> per lumi blocks

<METBx> (left) and <METBy> (right) for each luminosity block as function of the number                                                                 of events in the lumi block after the run selection :


Add a cut at the lumi block level :                                                                                                                                         if Nevt of lumi block > 1000 and SHIFTmetb of the lumi block  > 10  => exclude the run.
This removes 9 runs more.
Keep 85 % of runs (89.2 % of lumi blk and 89.0 % of events)

Luminosity block selection
For each lumi block we run on all events and get the mean values and RMS of METBx, METBy,SETB and MET-T42x, MET-T42y,SET-T42 distributions.

Cuts at the lumi block level :

SHIFT-metbxy < 4 GeV
RMS-metbxy   < 22 GeV
Mean-setb       > 80 GeV
Nevts > 500

With this selection  we  keep 40597 lumi blocks / 93.2 Mevts
and we save 92.9 % of lumi bks or  95.1 % of evts

      METBx for each lumi block                                        METBy for each lumi block
                  Before selection                                                     Before selection              
                   After selection                                                                              After selection

  <METB> for each lumi block after selection           RMS METB for each lumi block after selection

missingET Package documentation

Description of the corrections
Currently in the new missingET package (v00-06-05) MET is corrected for jet energy scale and muons.
The em-scale is being implemented now and not yet available.
In the future it will be also corrected for unclustured energy.

Old MET variables will still be in the missingET chunk for backward compatibility and new variables of corrected MET are added.
The package missingET is called by d0correct afterthe other Id packages and MET corrections come   from these packages.

The missing transverse energy corrected is META or METB (generically called MET below).
It's determined on cells with energy>0 and not belonging to the CH. The CH fraction of good JCCA and JCCB jets is also taken (META and METB refer to JCCA/B).

CORRECTIONS

*  For the jet energy scale, there is a list of good certified jets provided by the method  isGoodJet(*jet).
For each of these jet, there is a correction to apply to MET given by  : jetcorr:forMET.
The fact that the jet  is matched  with a muon is taken into account to determine the JES correction applied to MET.
=> Note that even if the jet is matched with a muon, this correction will only be for the jet part and at this step, MET is not corrected for the muon.

For the muons, there is a list of good certified medium muons provided by the method isGoodMuon(*muon).
The correction is made simply by subtracting the transverse momentum of each muon to MET.
Note that the correction is applied for all medium muons (track matched or not).

* For the electro-magnetic scale, there is a list  of good certified em objects provided by isGoodEM(*em).
There is a matching made between each em object and the jets. For the em objects which are not jets, an em-scale correction is applied.
 

The corrected MET is returned by the following methods :

getMETACorrCALO         ->  MET                          corrected for JES of  JCCA jets and for electrons
getMETACorrCALOxy      ->  METx , METy               (and for em-scale in next version)
getSETACorrCALO           ->  SET

getMETBCorrCALO         ->  MET                          corrected for JES of  JCCB jets and for electrons
getMETBCorrCALOxy      ->  METx , METy         (and for em-scale in next version)
getSETBCorrCALO           ->  SET
 

getMETACorrCALOMU       ->  MET                    corrected for JES of  JCCA jets, for electrons and muons
getMETACorrCALOMUxy    ->  METx , METy        (and for em-scale in next version)
getSETACorrCALOMU         ->  SET

getMETBCorrCALOMU        ->  MET                    corrected for JES of  JCCB jets, for electrons and muons
getMETBCorrCALOMUxy    ->  METx , METy        (and for em-scale in next version)
getSETBCorrCALOMU         ->  SET

Sample WZ, Z->ee , 117pb-1 , 12000 evts, p14TMBfixer01 + d0correct
MET corrections for JCCA (blue) and JCCB (red) for respectively CH, JES, bad jets,
em-scale and muons

Requiring no jets
METC (black), METD (green), METE (purple) with METE = METC -T42 corrected
META (blue) and METB (red)

                        Uncorrected                                                   Corrected