Atlantis tutorialJon Couchman (UCL),

Hans Drevermann (CERN),

Gary Taylor (UCSC)

16 May 2003 Atlas software week/CERN

Outline

• Introduction• Data visualization – Hans Drevermann• Basic concepts (presentation)• Hands on demonstration of basic functionality• User session ---- Coffee ---- • Advanced features (presentation)• Hands on demonstration of advanced features• User session • Access to events – Jon Couchman• Questions & answers

Atlantis goals

Primary • visual investigation and physical understanding of

complete Atlas events.

Secondary • help develop reconstruction and analysis

algorithms • debugging during commissioning • pictures and animations for publications,

presentations and exhibitions • event display for simple test-beams• online event display

Data

The following data may currently be visualized by the program

• 3D silicon points, silicon strip clusters and TRT straws

• Simulated tracks, neutral particles and vertices

• Reconstructed tracks iPatRec, xKalman

• Hit-to-track associations (kine, iPatRec only)

• Reconstructed secondary vertices

• LAr, TILE, HEC and FCAL calorimeter cells and clusters.

• MDT, RPC, TGC, CSC hits and CSC clusters

• Simulated and reconstructed muon tracks (MOORE)

Detector/Data oriented projections

3D Cartesian coordinates x,y,z are not always optimal for colliding beam experiments

More natural and useful are the non-linear combinations which reflect the design of ATLAS

= (x2+y2),= atan2(y, x),= log( z/(z/2+1)

where x, y, z need to be slightly modified to take into account the primary vertex of the underlying event (xvtx yvtx zvtx )

x' = x-xvtx , y' = y-yvtx , z' = z-zvtx

r

Y/X projection – TILE, LAr barrel, RPC (intuitive)

RPC

projection – like Y/X, but prompt tracks are straight lines

projection – calorimeters, muon hits (sector) (intuitive)

X'projection – muon hits and their association to Moore tracks

projection – TRT and LAr endcaps, HEC, TGC phi strips

TRT

TGC

projection and the V-Plot

Max

cm

V-Plot Draw each space point twice at

+k*(Max) and -k*(Max)

3D information

For tracks can judge

• • • pt (slope of V arms)• charge ( -ve V +ve)

Distorted V’s track not from IP

low p, -ve

high p, +ve

projection – track to calorimeter associations (30 GeV electron)

Pt=29.3 GeVE =31.2 GeV

LAr Presampler

LAr Layer 1 LAr Layer 2 LAr Layer 3

Island (guides eye)

Track(enters LAr here)

Cell geometry

Area E

User interface

Menu bar(IO,preferences,help)

Window Control (zoom,copy, DnD)

Commands

Output window

Parameter groups

Projections

Interaction Control

Parameters

Online help – available for every component

Right click on component for online help (hyper-linked HTML)Hover for tool-tip help

Interactions

• ZMR - zoom, move and rotate w.r.t defined center

• Rubberband - selection and zooming

• Pick - pick and move to (selection and query)

• Fisheye - relative expansion of central region

• Clock - relative expansion of angular region

• Synchro-cursors - correlation between different projections

• Scale - copy scales between windows

Mostly mouse driven with sometimes amodifier key pressed on the keyboard

Input Data

Atlantis is a JAVA application

It communicates with Athena via dedicate XML files produced by JiveXML ( see talk by J.Couchman)

These files are best grouped and compressed inside zip files

Single design luminosity event is approx 20 MB (XML)

4 MB (zip)

Detector Geometry

• Used to convey quickly to the user the context in which hits are to be viewed.

• Idealized geometry is adequate and desirable. (e.g. LAr pre-sampler is only 1 cm thick and would be invisible if drawn as such

• Stored in two separate XML files. • muon geometry derived from parameter book.

Printing

File => print => EPS, PNG, GIF

EPS – high quality vector graphics

good for posters, publications

(file size 200KB - 2MB)

PNG – compressed bitmap

good for ppt presentations + web

(file size 20-50 KB)

AtlFast

User defined geometry (e.g. MDT - cosmic test stand)

Web page

• www.cern.ch/atlantis

• How to download, install and run Atlantis

• Picture database (example event displays)

• Presentations

Contibutors

Many people contributed to the development of Atlantis. In particular

Gary Taylor (UC Santa Cruz) Principal developer

Hans Drevermann (CERN/EP) Original ideas, FORTRAN version

Dumitru Petrusca (Siegen/CERN) Initial work on GUI, calorimeters

Jon Couchman (UCL) Athena algorithm (JiveXML)

Frans Crijns (Nijmegen) Muon geometry

Peter Klok (Nijmegen) Picture database

Atlantis tutorial-2Jon Couchman (UCL),

Hans Drevermann (CERN),

Gary Taylor (UCSC)

16 May 2003 Atlas software week/CERN

Analysis Techniques

Data to be viewed may be

Cut - e.g. by pT, energy, association…

Colored - by associations , layer, sub-detector

more powerful when used in combination

e.g. selected only hits belonging to kine tracks

and color them by their associated reconstructed track

( inconsistencies indicate problems)

Superimposed – iPatRec tracks over true tracks

Check track reconstruction in difficult design luminosity event

• Selected event has two high pt (>560GeV) jets ( DC1dataset 2045)

• Luminosity 1034

• Silicon space points 27,000

• TRT hits 240,000

• Reconstructed tracks 1,200

• Reconstructed in 20 minutes

2D projections of Inner Detector data not very useful at design luminosity(TRT -ve barrel only)

V-Plot silicon space points calorimeters

Filtering of space points available inside Atlantis

Filter space points with a histogram based technique which selects hits consistent with tracks originating from the primary vertex.

Time = 1 sec/event

ATLAS note in preparation

Filtered hits iPatRec tracks True tracks

236 tracks 440 GeV

34 tracks 410 GeV

25 tracks222 GeV

27 tracks270 GeV

Tracks lost in core of central jet

STr,iPat,S3D(STr,iPat) iPat, xKal iPat,S3D(Filter,iPat)

Lists

Up till now we have seen how to investigate data and association present on the input file.

Lists allow user to dynamically create and manage their own associations

grouping of object

perform context dependent operations

e.g. vertex a set of reconstructed tracks

Identifying secondary vertices Look for a group of nearby kinked V’s in the VPlot

Reconstructed tracks True tracks

D

B

Y/X projection – region around the primary vertex

• Region around primary vertex

Reconstructed tracks True tracks

Primary

B

D

3 errorellipse

Secondary vertex region best displayed in abstract 3D Box

Planecontainingprimaryvertex

Planecontainingsecondaryvertex

primaryvertex

Ellipsesrepresenttrack error (1)

secondaryvertex

Space point formation from silicon strip clusters

iPatRec track

u-strip

v-strip

-strip

S3D (pixel)

S3D missing?

50 m

Comparison of muon and inner detector track fits

V-Plot allows comparison of and pt

p = 28 GeVp = 5 GeV = 1.5 deg= 0.02

p = 25 GeVp = 4 GeV = 1 deg= 0.01

Inner detector tracks

muon tracks

Cell clustering and Jet reconstruction – AtlFast (DC1- QCD event)

Cells coloured by cluster (Area E)

Jet (Area E)

E= 13 GeVE= 347 GeV

Details of cell clustering

?

Bug ?

Contibutors

Many people contributed to the development of Atlantis. In particular

Gary Taylor (UC Santa Cruz) Principal developer

Hans Drevermann (CERN/EP) Original ideas, FORTRAN version

Dumitru Petrusca (Siegen/CERN) Initial work on GUI, calorimeters

Jon Couchman (UCL) Athena algorithm (JiveXML)

Frans Crijns (Nijmegen) Muon geometry

Peter Klok (Nijmegen) Picture database