Muon Working Group nano/picoDST's Tutorial

• (Frederic) march 5th, 2004 - Update nanoDST and picoDST documentation.

This tutorial aims to help beginners to run through the MWG nanoDSTs code:

• Short overview : provides links to nanoDST documentations and gives some information. TO BE UPGRADED
• How to produce MWG nanoDSTs : provides information about the nanoDST production process. Provides, in addition, some files to use as starting examples.
• MWG nanoDSTs variables : provides information about MWG variables, and the functions to access them.
• How to produce picoDSTs : gives information about analysis macros. Also provides a short example to analyze a nanoDST.
• dimuon picoDSTs variables : provides information about variables stored within dimuon picoDSTs.

MWG nanoDST overview

• MWG Package Documentation : MWG_doc.ps (last update 03/03/04)

How to produce MWG nanoDSTs

• Using Fun4All:
  Using Fun4All framework, one can either produce at the same time DSTs and nanoDSTs out of PRDFs or produce nanoDSTs out of DSTs. Here are the corresponding macros:
  • Fun4Muons.C : to make, at the same time, DSTs and nanoDSTs out of PRDFs.
  • Fun4MWG.C : to make nanoDSTs out of DSTs.
• Raphael's tutorial web page.
• MWG.rcp: The Run Control Parameter file.
  This file contains all the input parameters used to produce the output Muon nanoDST. It is read during the execution; consequently, one doesn't have to recompile the code when changing input parameters. Input parameters are divided into four categories: The event selection parameters, the particle selection parameters, the dimuon parameters and the output branches parameters.
  Event selections: Event selections act as event filter. Events passing these cuts are stored in the output nanoDST.
  • vertexcut (default=40cm): if | event Zvertex | < vertexcut, keep event and proceed.
  • mintrackcut (default=1): if number of tracks >= mintrackcut, keep event and proceed.
  • maxtrackcut (default=1000): if number of tracks <= maxtrackcut, keep event and proceed.
  
  Particle selections: Particle selections act as particle filter within an accepted event. Particles passing these cuts are stored in the output nanoDST.
  • ptlowcut (default=0): if particle pT <= ptlowcut, keep particle and proceed.
  • pthighcut (default=1000): if particle pT >= pthighcut, keep particle and proceed.
  • minhitcut (default=0): if number of hits within the track >= minhitcut, keep particle and proceed.
  
  Dimuon selections: Dimuon branch processing is optionnal and controlled by dodimu. If dimuon processing is selected, dimuons passing the cuts are stored in the output nanoDST.
  • dodimu (default=false): if dodimu=true, dimuon branch is produced.
  • dimasscut (default=0.5 GeV): if dimuon mass >= dimasscut, keep dimuon and proceed.
  
  Output branches selections: Since Muon reconstruction can be done by either mut package or mutoo package or both, one can produce either one or two corresponding branches in the output nanoDST.
  • doframework (default=1):
    • if doframework=0 produce PHMuoTracks branch only (mut package output)
    • if doframework=1 produce PHMuoTracksOO branch only (mutoo package output)
    • if doframework=2 produce both branches.

MWG nanoDST variables

• Muon tracks information : contains MuoTracks variables and access methods information.
• Dimuons information : contains diMuoTracks variables and access methods information.

Muon Tracks information

• int get_npart() = number of muon tracks within the event.
• short get_nhits(int i) = i^th track number of hits (16 hits maximum).
• int get_charge(int i) = i^th track charge.
• float get_xpos, get_ypos, get_zpos (short arr, int i) = i^th track x, y, z position at station 0 (vertex), station 1, station 2 or station 3 (arr=0,1,2,3). Only Station 0 (vertex) filled for MUTOO.
• float get_px, get_py, get_pz (short st, int i) = i^th track x, y, z momentum at station 0 (vertex), station 1, station 2 or station 3 (st=0,1,2,3). Only Station 0 (vertex) filled for MUTOO.
• float get_st1_bp_P(short arr, int i) = i^th track x, y, z (arr=0,1,2) station 1 Bent Plane momentum. Not filled for MUTOO.
• float get_st1_bp_pos(short arr, int i) = i^th track x, y, z (arr=0,1,2) station 1 Bent Plane position. Not filled for MUTOO.
• float get_cov(short arr1, short arr2, int i) = i^th track covariance matrix (arr1,arr2) element.
• float get_chisquare(int i) = i^th track chisquare.
• float get_ghostflag(int i) = i^th track ghostflag (0=is not a ghost, 1=is a ghost).
• int get_muTRhits(int i) = i^th track hits information.
• bool is_muTRhit(int i, int st, int gap, int plane) = true if, for i^th track, plane^th cathode of gap^th gap of st^th station is hit.
• int get_muIDhits(int i) = i^th track's road hits information. Not filled for MUTOO.
• bool is_muIDhit(int i, int plane, int orient) = true if, for i^th track's road, orient^th tube of plane^th plane is hit. Not filled for MUTOO.
• float get_muID_gap0(short arr, int i) = return i^th track road position and direction at gap0 (x,y,z,dxdz,dydz). Not filled for MUTOO.
• float get_muIDOOchi(short iroad, int i) = i^th track's iroad^th road chi2 information. MUTOO only.
• int get_muIDOOhits(short iroad, int i) = i^th track's iroad^th road hits information. MUTOO only.
• bool is_muIDOOhit(int i, int plane, int orient) = true if, for i^th track's road, orient^th tube of plane^th plane is hit. MUTOO only.
• float get_muIDOO_gap0(short arr, short iroad, int i) = return i^th track iroad^th road position and direction at gap0 (x,y,z,dxdz,dydz). MUTOO only.
• float get_TMutTrk_status(int i) = return i^th track status. MUTOO only.
• short get_PID(int i) = i^th track ID. Not filled yet.
• float get_MuonConfidence(int i) = i^th track probability to be a muon. Not filled yet.
• float get_PionConfidence(int i) = i^th track probability to be a pion. Not filled yet.

Dimuons information

• int get_ndimu() = number of dimuons within the event.
• int get_ditrkIndex(short arr, int idimu) = idimu^th dimuon track indices (arr=0,1).
• float get_dimass(int idimu) = idimu^th dimuon mass.
• int get_dicharge(int idimu) = idimu^th dimuon charge (0=+-, 1=++, -1=--).
• float get_dipx, get_dipy, get_dipz (int idimu) = idimu^th dimuon x, y, z momentum.
• float get_vtx_xpos, get_vtx_ypos, get_vtx_zpos (int idimu) = idimu^th ditrack vertex position.
• float get_vtx_chisquare (int idimu) = idimu^th chisquare from vertex fit.
• float get_vtx_cov (short arr1, short arr2, int idimu) = idimu^th covariance matrix from vertex fit.
• float get_vtx_chrg_1, get_vtx_chrg_2 (int idimu) = idimu^th .
• float get_vtx_px1, get_vtx_py1, get_vtx_pz1 (int idimu) = idimu^th .
• float get_vtx_px2, get_vtx_py2, get_vtx_pz2 (int idimu) = idimu^th .

How to produce MWG picoDSTs

Macros to produce picoDSTs stand in CVS (in offline/packages/MWGpico).

• How to install MWGpico.
  • >mkdir myanalysis
  • >cd myanalysis
  • >mkdir Sources
  • >mkdir Builds
  • >mkdir Libraries
  • >cd Sources
  • >cvs co -d . offline/packages/MWGpico
  • >cd ../Builds
  • >mkdir MWGpico
  • >cd MWGpico
  • >../../Sources/MWGpico/autogen.sh --prefix=/direct/phenix+u/[yourname]/myanalysis/Libraries
  • >make; make install
  
  
• How to run MWGpico.
  • From myanalysis: >cd Sources/MWGpico/macros
  • >setenv LD_LIBRARY_PATH /direct/phenix+u/[yourname]/myanalysis/Libraries/lib:$LD_LIBRARY_PATH
  • Change the file file.txt to load your own nanoDSTs.
  • >root -b -q 'doMWGpico.C(0,"file")'
  Note that one can choose to run with an "official" list of file. See MWGpico/LoadNano.h for possible choices.

dimuon picoDST variables

The core object of the dimuon picoDSTs is the dimuon. It means that, within the rootuple, one entry corresponds to one dimuon. For each dimuon, one can find information on the associated run, the associated event, the dimuon itself and the two associated tracks.

• run information : contains MuoTracks variables and access methods information.
• event information : contains diMuoTracks variables and access methods information.
• Dimuon information : contains diMuoTracks variables and access methods information.
• tracks information : contains diMuoTracks variables and access methods information.

run information

• Run_Number = dimuon's run number.

event information

• Evt_Number = dimuon's event number.
• Evt_Nmu = number of tracks within the event.
• Evt_bbcZ = event's BBC Z vertex.
• Evt_bbcCentrality = event's BBC centrality.
• Evt_fclCentrality = event's FCAL centrality.
• Evt_zdcCentrality = event's ZDC centrality.
• Evt_zdcEnerN = event's north ZDC energy.
• Evt_fclGreyN = event's north FCAL energy.
• Evt_pseudotrigS_2D = pseudo trigger 2 deeps South.
• Evt_pseudotrigS_1D1S = pseudo trigger 1 deep 1 shallow South.
• Evt_pseudotrigN_2D = pseudo trigger 2 deeps North.
• Evt_pseudotrigN_1D1S = pseudo trigger 1 deep 1 shallow North.
• Evt_vtxchi2 = vertex chi2 (mutoo).
• Evt_vtxooz = vertex z position (mutoo).

dimuon information

• mass = dimuon mass.
• charge = dimuon charge (0 or 1 or -1).
• rapidity = dimuon rapidity.
• pT = dimuon pT.
• p = dimuon p.
• xF = dimuon xF.
• x1 = dimuon x1.
• x2 = dimuon x2.
• costhCS = dimuon cosinus theta Collins-Soper.
• dca = DCA (Distance of Closest Approach) between the 2 tracks (à la Mike).
• xvtxbp = Bend plane x vertex (à la Mike).
• yvtxbp = Bend plane y vertex (à la Mike).
• zvtxbp = Bend plane z vertex (à la Mike).

tracks information

• Tr0_chi2 (Tr1_chi2) = track chi2.
• Tr0_px (Tr1_px) = track px.
• Tr0_py (Tr1_py) = track py.
• Tr0_pz (Tr1_pz) = track pz.
• Tr0_idhits (Tr1_idhits) = muID hit pattern.
• Tr0_idquad (Tr1_idquad) = muID quadrant at gap 0.
• Tr0_trhits (Tr1_trhits) = muTr hit pattern.
• Tr0_DS3 (Tr1_DS3) = DS3 (à la Olivier).
• Tr0_DS3ctp (Tr1_DS3ctp) = DS3 (w/ const theta & phi).
• Tr0_idchi2 (Tr1_idchi2) = muID chi2.