DISCLAIMER

this page is work in progress

obtain (more) reliable information from the Brunel release notes, the minutes of the PAC meetings, the PPTS meetings, ... svn diff, svn log. It is hereby encouraged to ask for reconstruction versions / changes on the corresponding mailing list lhcb-reconstruction or your liaison person (charged PID, calorimeter objects, tracking-alignment-vertexing).

for reconstruction experts

I wrote the REC versions to enable package lookup via http://lhcb-release-area.web.cern.ch/LHCb-release-area/DOC/rec/releases/v13r3p1/ (although you can reach the the same information via cmt show uses)

2010

2011

at the time of writing, for a maximum data set, you want Reco12

Reco12

reprocessing of all 2011 data.

new wrt 2010 * replaced PatVelo by FastVelo, TsaSeeding by PatSeeding, TrackMatching by PatMatch. none of these brought a systematic change I'm aware of.

Reco12a

FIXME

for the experts: Reco12a uses REC v12r0 in Brunel v41r1p1

2012

at the time of writing, for a maximum data set, you want Reco13+Reco13a+Reco13c (yes, no PreReco13 and no Reco13b)

PreReco13

didn't look up what went on exactly. let's call it a beta test for Reco13.

There is only Stripping18 selected, not okay PreReco13

Reco13

prompt reconstruction of 2012 data

used in Stripping18 and Stripping19

• new OT projector: real tracks have smaller track chi2 values than before (if they go through the OT). This changes the phi distribution of real tracks wrt. Reco12 (at a given overall cut efficiency). The track chi2 distribution for real IT and OT tracks are more similar to each other than before. Also chi2 values for ghosts are smaller than before. The discrimination power is slightly better than in Reco12.
• new FastVelo version (v1r7): better track finding efficiency for high IP tracks. reduced effect of upper life time acceptance.
• various pattern recognition tunings: no impact on physics observed so far
• negative side effects: new track chi2 cut tuning needed. probably new acceptance studies needed. higher ghost rate than reco12

for the experts: Reco13 uses REC v13r2 in Brunel v42r2p2

Reco13a

prompt reconstruction of 2012 data

used in Stripping19a

• new clone killing strategy: more elaborate strategy of deciding which track of a particle to keep. improved performance for downstream & Velo tracks. longtrack efficiency rather stable. cuts aligned with standard particle cuts in rich reco and davinci => no tracks with chi2>3 kept on DST.
• no new negative side effects known so far.

for the experts: Reco13a uses REC v13r3 in Brunel v42r3p2

Reco13b

use Reco13c if available prompt reconstruction of 2012 data

not used for any good flagged data. not to be used

• FastVelo internal clone reduction improved (v1r10): slightly better longtracking efficiency than reco12 in combination with the new clone killer (introduced in reco13a).
• this version came with wrong database settings (correct me if i'm wrong / inaccurate here).
• no new negative side effects known which are inherent to the reconstruction changes

for the experts: Reco13b uses REC v14r0 in Brunel v43r0

Reco13c

prompt reconstruction of 2012 data

used in Stripping19b

• no reconstruction changes. corrected database
• negative side effects as in Reco13

Stripping versions

Cut on "(PT>250*MeV) & (MIPCHI2DV(PRIMARY) > 4.)" added for StdLoose common particles for Stripping17b onwards.

Stripping	DaVinci version	CommonParticles.Utils defaults	AppConfig
Stripping17b	v30r0p1	Chi2Cut < 5, KL > 5000, (PT>250*MeV) & (MIPCHI2DV(PRIMARY) > 4.)	MaxCandidates = 2000
Stripping18	v30r2p3	Chi2Cut < 5, KL > 5000, (PT>250*MeV) & (MIPCHI2DV(PRIMARY) > 4.)	MaxCandidates = 2000, Chi2Cut < 3
Stripping18a	v30r2p3	Chi2Cut < 5, KL > 5000, (PT>250*MeV) & (MIPCHI2DV(PRIMARY) > 4.)	MaxCandidates = 2000, Chi2Cut < 3
Stripping18b	v30r2p3	Chi2Cut < 5, KL > 5000, (PT>250*MeV) & (MIPCHI2DV(PRIMARY) > 4.)	MaxCandidates = 2000, Chi2Cut < 3
Stripping19	v30r3	Chi2Cut < 5, KL > 5000, (PT>250*MeV) & (MIPCHI2DV(PRIMARY) > 4.)	MaxCandidates = 2000, Chi2Cut < 3
Stripping19a	v30r4p1	Chi2Cut < 5, KL > 5000, (PT>250*MeV) & (MIPCHI2DV(PRIMARY) > 4.)	MaxCandidates = 2000, Chi2Cut < 3
Stripping19b	v31r0	Chi2Cut < 5, KL > 5000, (PT>250*MeV) & (MIPCHI2DV(PRIMARY) > 4.)	MaxCandidates = 2000, Chi2Cut < 3

-- PaulSeyfert - 16-Jul-2012