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A scanner is a machine used to make a representation of a physical object in the digital world. Generally this is to scan paper (with pictures or text). In earlier days, scanner was the job title of a person who counted and measured particle tracks on photographic images of particle interactions (from bubble chambers, cloud chambers, spark chambers, etc.).

The description of the persistent class types that create the BaBar database data model is called the schema.

Reference Link (http://www.slac.stanford.edu/BFROOT/www/doc/workbook/objectivity1/objectivity1.html#terms)

Material (usually plastic) that has the property of emitting light when a particle passes through it.

Secure Shell (ssh) is a secure replacement for telnet, rlogin, rsh, and rcp. It uses encryption to keep information that you send over the network from being seen by others. It also uses public and private keys to valida te that the host and client machi nes are who they say they are. Since SCS will disable RSH access soon, BaBar users should start switching to SSH for accessing SLAC machines.

Reference Link (http://www.slac.stanford.edu/comp/unix/ssh.html)

A term for those Monte Carlo signal events not truth-matched

Positive voltage (2 kV) wire in Drift Chamber to which electrons are attracted. Sense wires are 20 um tungsten-rhenium alloy, plated with gold. They are capacitively coupled to the DCH front-end electronics.

Reference Link (http://www.slac.stanford.edu/BFROOT/www/Detector/CentralTracker/mechanical/drift_system/index.html)

A Framework sequence is a list of related modules that must be placed together and executed in sequence to provide a defined service to the Framework.

Reference Link (http://www.slac.stanford.edu/BFROOT/www/doc/workbook/framework1/framework1.html#sequences)

setboot is a command which should be used by the developers to setup access to their private test federation. For this command to run successfully, test release directory should have file named '.bbobjy' containing a line 'FD_NUMBER := NUM', where NUM is the

A sixth portion of a whole part. In case of the IFR, is the sixth portion in which the barrel is divided in Phi

The silicon vertex detector/tracker, (SVT), is the only tracking device inside the 20cm radius of the BaBar support tube. It is used to measure precisely both impact parameters for charged tracks (z and r - phi).

Reference Link (http://www.slac.stanford.edu/BFROOT/www/doc/workbook/detector/detector.html#systems)

Silo is the name given to a large structure containing thousands of tapes, several tape drives and a robot to allow automatic staging of tapes.

a simulation module which produces the detector response (digitization or digi) given the simple particle position and momentum variables (GHits) generated in a tracking and physics simulation module such as BgsApp.

The system set up to produce Monte Carlo events in BaBar. Production is done at SLAC and in a number (currently 25) remote sites. A number is attached to the acronym to indicate the version

Reference Link (http://www.slac.stanford.edu/BFROOT/www/Computing/Offline/Production)

Magnitude of CP asymmetry due to interference between mixing and decay of certain B decays, such as the gold-plated mode B0 -> J/psi K_S. Beta is one of the angles of the CKM triangle.

Sub-set of events selected with a specific physics signature or decay topology for use in BaBar analyses.

Reference Link (http://www.slac.stanford.edu/BFROOT/www/Computing/Operation/SKP.htm)

"Skim" is part of a "stream", that is a collection of events selected on the basis of "tagbits", defined by analysis groups as a pre-selection for sets of physics channels.

Reference Link (http://www.slac.stanford.edu/BFROOT/www/Physics/skims/skimsRelease10.html)

BAD 116 Particle ID selector based on SVT, DCH dEdX and DIRC information; mainly used for likelihood-based kaon identification

SLUO was formerly called the Slac-Lbl Users Organization.

Collaboration which measured the left-right asymmetry at the Z resonance. The SLD detector is located in the CEH (Collider Experimental Hall) at the SLC (SLAC Linear Collider) at SLAC.

Reference Link (http://www-sld.slac.stanford.edu/sldwww/sld-working.html)

This set of tools (in the BaBar packages SoftRelTools, SiteConfig, SrtAdmin and PackageList) support the development, building and distribution of BaBar releases.

Reference Link (http://www.slac.stanford.edu/BFROOT/www/Computing/Environment/Tools/SRT/)

The complete set of Software Release Tools, (SRT), refers to SoftRelTools. SoftRelTools is itself a package, and is used to install and maintain releases. The BaBar Software Release Tools are based on the Concurrent Versions System, (CVS).

Reference Link (http://www.slac.stanford.edu/BFROOT/www/doc/workbook/srt1/srt1.html)

To achieve good momentum resolution without increasing the tracking volume the BaBar solenoid magnet, (MAG), provides a field of 1.5T. The magnet coil is therefore of superconducting design.

Reference Link (http://www.slac.stanford.edu/BFROOT/www/doc/workbook/detector/detector.html#systems)

A regularly-performed calibration of the ElectroMagnetic Calorimeter (EMC). A liquid (Fluorinert) is activated via a neutron generator and pumped past the front of the crystals. The 6.1 MeV decay photons are then detected by the crystals for an ab solu t e calibration at this low energy.

Reference Link (http://www.slac.stanford.edu/BFROOT/www/Detector/Calorimeter/RadSource/index.html)

SP2 analysis federation. Used to run analysis based on the Simulation Production Version 2 Monte Carlo.

SP2 production boot file, should not be used by users.

Monte Carlo Simulation produced for run 1 data using Geant 3 and release 8

SP3 analysis federation. Used to run analysis based on the Simulation Production Version 3 Monte Carlo.

SP3 production boot file, should not be used by users.

Monte Carlo simulation production for run 1 and 2 data using Geant 4 and release 10 during 2001-2002

Reference Link (http://www.slac.stanford.edu/BFROOT/www/Computing/Offline/Production/)

SP4 analysis federation. Used to run analysis based on the Simulation Production Version 4 Monte Carlo.

SP4 production boot file, should not be used by users.

This is the database used by the OPR multi-node calibration. Every OPR node writes all calibrations in the separate container.

Reference Link (http://www.slac.stanford.edu/BFROOT/www/Computing/Online/PromptReco/OprDatabases.html)

This is a database used in Prompt Calibration to collect information from all the nodes participating. Each node writes to the database and the finalise nodes reads back all the contributions.

srtpath is a BaBar UNIX command that sets up the PATH variable for BaBar's Software Release environment.

Reference Link (http://www.slac.stanford.edu/BFROOT/www/doc/workbook/srt1/srt1.html#setup)

Staging is the loading of information from (usually) tape to (usually) disk. This implies that the data will not remain on disk forever and may need to be restaged in the future.

A component of the BaBar DIRC Cerenkov counter which contains very pure water.

Reference Link (http://www.slac.stanford.edu/BFROOT/www/Detector/DIRC/dirc_whatsit.html)

STK are the current vendor for SLAC tapes and drives (which are the Eagle technology currently).

Reference Link (http://www.stortek.com/)

This is the BaBar computing environment's version of the glimpse command. Use this command to search the sources of a release for a given pattern.

Reference Link (http://www.slac.stanford.edu/cgi-wrap/bfman/page?srtglimpse)

The super Fox-Wolfram moments are a means of continuum suppression. The underlying idea of continuum suppression techniques is the difference in the event shapes of continuum and BBbar events. Since BBbar events are resonant only little energy is released and these events tend to be spherical. In contrast continuum events exhibit a large energy release and the q and qbar jets tend to emerge collimated back to back. A number of variables have been developed to quantify these differences, one of them are the Fox-Wolfram moments which are already defined elsewhere in this glossary. The l-th Fox-Wolfram moment is defined as H_l=sum_{ij} { |p_i||p_j| P_l(cos(p_i,p_j)) } where p_i is the i-th particle's momentum, and p_l is the l-th Legendre polynomial. The argument of P_l is the cosine of the angle theta_ij between particle i and particle j. The super Fox-Wolfram moments are extensions of the Fox-Wolfram moments, the terms in the summation of H_l are separated into 3 groups: (1) terms involving particles in the B candidate, (2) terms with some particles in the B candidate and others from the rest of the event, (3) terms involving only particles from the rest of the event. A Fisher discriminant (this is already defined elsewhere in this glossary) is then constructed from these terms. This Fisher discriminant is the so-called super Fox-Wolfram moment.

The shift which starts at 4pm and ends at midnight.

To add an entry to the Glossary use the BaBar Glossary Submission Form.

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Last significant update: 10-Sept-2002