LHCb Glossary

This glossary is intended as a reference for new (and old) LHCb members to quickly find out the basic meanings of common technical terms/acronyms. Please add words/acronyms you don't understand, or fill out the definitions for terms which you do.

A

B

Batch System

Blinding

C

CASTOR

Computing Element (The Grid)

Computing Elements (CEs) is the term used to describe computers which run jobs on the grid.

Concurrent Versions System (CVS)

CVS is a version control system that allows the user to record the history of their source files and document changes to new versions. CVS should be completely replaced by SVN in the LHCb software by the end of 2010.

Configuration Management Tool (CMT)

The CMT handles the production and setup of packages. It provides tools for the automation of building and compiling new projects and packages.

Coordinates

As you look along the detector from VELO to MUON, z is increasing, x is to your left, y is above, and phi=0 is defined along the x axis and phi=90 along the y axis. This means x points towards the Saleve. The definition for the LHC machine is opposite to this.

D

Davinci

Davinci is the main project software used for performing physics analysis on LHCb data. It is built on the Gaudi Framework.

Dataset File (DST)

E

Exclusive (selection)

F

FSR

Framework

A skeleton of an application, which users can put their own algorithms into. It provides the most commonly used code already in order to prevent duplicated effort between collaborators.

G

Global Event Cut (GEC)

Ganga

Ganga is a piece of software which allows users to run jobs seamlessly on the Grid, locally or on a batch system.

The Grid

The Grid is a global, interconnected network of computers (Computing Elements) used to run software remotely. It is commonly used by splitting a task into smaller "subjobs" which are submitted to multiple computers simultaneously.

Wikipedia article on the LHC computing grid

H

High Level Trigger (HLT)

I

Inclusive (selection)

Interval of Validity (IOV)

J

K

L

Level Zero Trigger (L0)

M

MicroDST

Mu

N

Non-Zero Suppressed (NZS)

O

P

Prescaled

Preshower (PS)

An LHCb subdector that assists the calorimeter with background rejection and charged particle identification (see SPD).

Primary Vertex (PV)

Prompt Particle

PVSS

The controlling software of the LHC. Often used as GUI panels in the control rooms. It allows for the manipulation of the hardware of detectors, online monitoring, alarms, access etc.

Q

R

RAW File

S

Scintillator Pad Detector (SPD)

A subdetector of the LHCb that allows for separation of electrons and photons by the identification of charged particles. Works in conjunction with the PS to allow good background rejection and photon identification in the calorimeter.

Sidebands

Storage Element (The Grid)

A storage element (SE) is disk used to store data on the Grid.

Stripping

Subversion (SVN)

SVN is a version control system that allows the user to record the history of their source files and document changes to new versions. By the end of 2010 the LHCb software will have migrated to SVN from CVS.

T

Trigger

Trigger Configuration Key (TCK)

U

V

W

X

Y

Z

Zero Suppressed (ZS)