P

Panoramix

Graphical display of detector and event information. Project website.

PCIe40: PCI express

Readout boards used for the data acquisition system, Experiment Control System and Timing and Fast Control (TFC). Refer to the LHCb Trigger and Online TDR for details. Each board has 48 bidirectional optical links for interfacing with the frontend electronics and one bidirectional optical link for interfacing the TFC.

PFN: Physical File Name

A path for a file on the grid, including the physical location to allow for access.

PHOTOS

Software package for adding final state radiation (FSR) to simulated particles. Eur. Phys. J. C45 (2006) 97

PID: Particle identification

The process of determining what species a final state particle is. Charged particle identification typically separates electrons, kaons, muons, pions and protons. Neutral particle identification typically separates neutral pions and photons.

PL: Project Leader

Person responsible for leading a substructure of LHCb that is formally called a Project. This should not be confused with working group conveners. See the list of current Project leaders.

Point 8

Interaction point of the LHC at which the LHCb pit and the cavern are located.

Power cycle

Short for "turning it off and on again".

PPG: Physics Planning Group

Advisory body to the LHCb management that defines the strategy and priority of the experiments physics programme.

Physics (Analysis) Working Group (often short "Working Group (WG)")

Group of analysts working on similar/related analyses in terms of research subject. PPWGs are coordinated by convenors (who are part of the PPG). Many working groups are further divided into subgroups. See the section below Physics Planning Group.

PPWG: Physics Performance Working Group

Groups in charge of maintaining tools and inputs into multiple analyses, such as luminosity measurements, PID methods and calibration, Flavour Tagging. PAWGs are coordinated by convenors (who are part of the PPG). See the section below Physics Planning Group.

Production Request

A request for processing centrally a physics request. Production Requests are managed by the LHCb distributed computing team via LHCbDIRAC. LHCb users can create production requests via the LHCbDIRAC Web Portal. Production Requests are subject to approval by the PPG.

Productions

Centrally managed processing, via LHCbDIRAC, of Production Requests. Examples of productions include: MC simulation, Reconstruction, Stripping, Working Group productions. A production is a combination of application steps.

Project (Constitutional Project)

A substructure of LHCb as defined by the LHCb constitution. Typically these are detectors (VELO, ST, CALO, …) but also HLT, Computing, Online, and RTA are projects. Not to be confused with Physics (Analysis/Performance) Working Groups (they differ in creation procedure, budget, authority, formal commitment from institutes…).

Project (Software Project)

Subdivision level at which LHCb software is hosted (version control, dealing with merge requests, builds, releases).

PRR: Production Readiness Review

A milestone during the construction of a subdetector. The PRR occurs after the EDR. The PRR is a meeting with accompanying documentation that describes the detailed design of a component system of the detector (e.g. sensors, an ASIC, high voltage system). Reviewers with relevant expertise from other subdetectors in LHCb and from other experiments are usually appointed to conduct the review and make recommendations. The PRR makes recommendations for revisions or approves that the final production of this element of the subdetector can start.

Pseudorapidity

The angle between a particle's trajectory and the beam axis, see Wikipedia.

PS: Preshower Detector

The PS consists of scintillating pads and is placed after the SPD and before the ECAL. A lead absorber is placed between the SPD and PS. The joint purpose of the SPD and PS is to reduce the background for the L0 electron trigger. The PS helps distinguish between electrons and charged hadrons.

PV: Primary Vertex

The point of the original, typically proton-proton, collision.

Pythia

The most commonly used Monte Carlo generator in LHCb. Typically simulates the proton-proton collision and hadronisation process. Website.