Dead material correction in CTB2004 testbeam

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1 Dead material correction in CTB24 testbeam Karl-Johan Grahn, KTH Stockholm Tancredi Carli, CERN

2 Role of testbeam Validate reconstruction: Geant4 physics Detector description In simple case, i.e. singe pion, test procedure on data For the moment, only study crack between LAr and Tile

3 Requirements Demands on DM reconstruction (in order of preference) No tail Good mean Good resolution

4 Canonical dead material formula E DM,rec = const E LAr3 E T ile ELAr3 E T ile Plot E DM,true against in a profile histogram and do a linear fit.

5 Problem 1 : Tails Consequence: DM energy overestimated, giving rise to a tail in reconstructed DM energy spectrum. Tail can be suppressed by requiring ELAr3 > M IP MIP in DM and in LAr3, but not in Tile hist2 hist1 Entries Mean RMS !6 SqrtLayersVisibleE ELAr3 ET ile TileVisible[]:LArVisible[3] {( *SqrtLayersVisibleE - )/ < 2} 3 TileVisible[] EDM,true :SqrtLayersVisibleE {( *SqrtLayersVisibleE - )/ <= 2 && DMLarTile >= } EDM,rec EDM,true EDM,true LArVisible[3]

6 2 GeV EDM,true GeV Visible energy in whole layer Sum of all clusters First cluster ELAr3 E T ile Problem 2 : Lots of energy missed by first cluster for low energy

7 Fraction of total layer energy in first cluster, as a function of layer energy GeV LAr ClustersLArVisible[][3]/LArVisible[3]:LArVisible[3] ClustersLArVisible[][3]/LArVisible[3] ClustersLArVisible[][3]/LArVisible[3] ClustersLArVisible[][3]/LArVisible[3]:LArVisible[3] LArVisible[3] GeV Tile LArVisible[3] ClustersTileVisible[][]/TileVisible[]:TileVisible[] ClustersTileVisible[][]/TileVisible[] ClustersTileVisible[][]/TileVisible[] ClustersTileVisible[][]/TileVisible[]:TileVisible[] 1 1 GeV LAr GeV Tile TileVisible[] TileVisible[]

8 Problem 3 : Remaining offset Clustering effects aside, there remains an offset of a few GeVs. If cutting out LAr3=MIP it gets even larger EDM,true :SqrtLayersVisibleE No cut ELar3 > 5 MeV htemp Entries Mean Meany 1.9 RMS RMSy The opposite of the tail problem ( Problem 1 ). No signal in LAr3 and Tile, but still signal in DM. Physical cause of this? Offset ELAr3 E T ile (1 GeV beam energy) (Visible energy whole layer)

9 A refined power law? Is the square root the best function to use? Instead of E DM,rec = const1 + const2 E LAr3 E T ile Try E DM,rec = const1 + const2 E p LAr3 Ep 1 T ile ( p 1) Do the fit for various values of p and compare χ 2, resolution and mean.

10 p =.2 p =.5 :LArVisible[3]^.8*TileVisible[]^(1-.8) { >= } GeV LArVisible[3]^.2*TileVisible[]^(1-.2) 5 1 GeV LArVisible[3]^.5*TileVisible[]^(1-.5) :LArVisible[3]^.5*TileVisible[]^(1-.5) { >= } :LArVisible[3]^.2*TileVisible[]^(1-.2) { >= } LArVisible[3]^.2*TileVisible[]^(1-.2) LArVisible[3]^.8*TileVisible[]^(1-.8) :LArVisible[3]^.8*TileVisible[]^(1-.8) { >= } :LArVisible[3]^.5*TileVisible[]^(1-.5) { >= } :LArVisible[3]^.2*TileVisible[]^(1-.2) { >= } p = LArVisible[3]^.5*TileVisible[]^(1-.5) LArVisible[3]^.8*TileVisible[]^(1-.8)

11 Mean as function of parameter 1 GeV Resolution as function of parameter ! 2 /NDF as function of parameter 5 ( *(LArVisible[3]^.2)*(TileVisible[]^.8) - ) / {LArVisible[3] > minires_2 5} ( *(LArVisible[3]^.3)*(TileVisible[]^.7) - ) / {LArVisible[3] > 5} minires1_2 ( *(LArVisible[3]^.4)*(TileVisible[]^.6) - ) / {LArVisible[3] > minires2_2 5} Entries 811 Entries 811 Entries 811 Mean.1237 Mean.1172 Mean.1118 RMS.5366 RMS.568 RMS ( *(LArVisible[3]^.5)*(TileVisible[]^.5) - ) / {LArVisible[3] > minires3_2 5} ( *(LArVisible[3]^.6)*(TileVisible[]^.4) - ) / {LArVisible[3] > minires4_2 5} ( *(LArVisible[3]^.7)*(TileVisible[]^.3) - ) / {LArVisible[3] > minires5_2 5} Entries 811 Entries 811 Entries 811 Mean Mean.1148 Mean.1176 RMS.4678 RMS.4682 RMS DM rec DM true DM true Cut: E LAr3 > 5GeV

12 Mean as function of parameter 2 GeV Resolution as function of parameter ! 2 /NDF as function of parameter 4 ( *(LArVisible[3]^.2)*(TileVisible[]^.8) - ) / {LArVisible[3] > minires_2 5} ( *(LArVisible[3]^.3)*(TileVisible[]^.7) - ) / {LArVisible[3] > minires1_2 5} ( *(LArVisible[3]^.4)*(TileVisible[]^.6) - ) / {LArVisible[3] > minires2_2 5} Entries 6768 Entries 6768 Entries 6768 Mean.1471 Mean.1526 Mean.169 RMS RMS RMS ( *(LArVisible[3]^.5)*(TileVisible[]^.5) - ) / {LArVisible[3] > minires3_2 5} ( *(LArVisible[3]^.6)*(TileVisible[]^.4) - ) / {LArVisible[3] > minires4_2 5} ( *(LArVisible[3]^.7)*(TileVisible[]^.3) - ) / {LArVisible[3] > minires5_2 5} Entries 6768 Entries 6768 Entries 6768 Mean.169 Mean.1764 Mean.1764 RMS.587 RMS RMS DM rec DM true DM true Cut: E LAr3 > 5GeV

13 Possible development Find observable sensitive to shower start to get rid of tail? Shower depth? Use real data as soon as possible. Physical explanation of offset. Estimate type of energy deposition in ELAr3, ETile to get better resolution: MIP, hadronic shower, EM showers. Leakage and upstream losses. Cluster definition and out-of-cluster correction?

Study of TileCal Sampling Fraction for Improvement of Monte-Carlo Data Reconstruction

Study of TileCal Sampling Fraction for Improvement of Monte-Carlo Data Reconstruction Study of Cal Sampling Fraction for Improvement of Monte-Carlo Data Reconstruction J.Budagov 1), G.Khoriauli 1), ), J.Khubua 1), ), A.Khukhunaishvili 1), Y.Kulchitsky 1), 4), A.Solodkov 5) 1) JINR, Dubna