1 / 13

STAR Software Walk-Through

This document provides a comprehensive overview of the STAR software used for analyzing vast datasets produced from high-energy physics experiments, particularly at the RHIC collider. It describes the analysis process, tools, and computing resources such as PDSF and RCF. Key functionalities include data mining, running analysis on simulated or real data, utilizing the Maker framework for standardized analysis, and plotting results. This guide is essential for researchers looking to efficiently analyze events from the collider's data.

renee
Télécharger la présentation

STAR Software Walk-Through

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. STAR Software Walk-Through

  2. Doing analysis in a large collaboration: Overview • The experiment: • Collider runs for many weeks every year. • A lot of data to look at! • In 2007, ~70M minimum bias events. • Need computers to be able to analyze vast dataset. • Analysis Software: • Find relevant data • Develop analysis code • Interface to the data • Analysis code: plots and correlations of experimentally measured quantities • Submitting jobs to the batch farm • Plotting results

  3. Computing resources • Facilities available for STAR • PDSF (in Berkeley, part of NERSC) • Parallel Distributed Systems Facility • RCF (in Brookhaven Lab) • RHIC Computing Facility • Log in to PDSF: pdsf.nersc.gov • Web page: • http://www.nersc.gov/nusers/resources/PDSF/ • FAQ • USER accounts • Monitoring of farm conditions • … • Log in to RCF: rssh.rhic.bnl.gov • Web page: • http://www.rhic.bnl.gov/RCF/

  4. Doing Analysis 101 • For real or simulated data that has already been produced into a standard format: Run analysis on data. Tools: MuDST StMcEvent Plot results of analysis. Tools: ROOT classes. Find Data HPSS NFS local. Tools: FileCatalog

  5. Tools: • FileCatalog (get_file_list.pl) • http://www.star.bnl.gov/STAR/comp/sofi/FileCatalog/ • Finding Files (of course) that satisfy certain conditions: • production library used, trigger setup used, run numbers, collision system, … • i.e. it is a database of our data. • Examples of usage found in link above. • Note for PDSF: make sure you have a .chos file. I selected /auto/redhat8 as my environment. • Without an environment properly set, perl won’t work!

  6. Tools: • Scheduler • Used to submit jobs to the RCAS linux farm in batch mode. • RCAS: ~10 interactive nodes, ~150 batch nodes. • How to use it: • XML script that specifies • files to be used (e.g. using a catalog query) • macro to be executed (i.e. analysis to be done) • what to do with the output

  7. Analyzing Example: Real Data, Step I • Find events of interest • e.g. Au Au collisions, 200 GeV. (2004 data) • Many collisions and triggers have been used. • Example: Looking at “Minimum bias” triggers • This trigger is meant to capture almost all interactions. • Every trigger detector introduces a bias, this trigger is meant to reduce the bias introduced as much as possible. • Trigger ID: • Each file can have events that were selected by various trigger conditions • ID picks out a given trigger condition. • 2004 list of triggers: • http://www.star.bnl.gov/protected/common/common2004/trigger2004/triggers2004.html

  8. A file catalog query… pc2606:~ 54> get_file_list.pl -keys 'path,filename' -cond 'storage=NFS,filename~st_physics,collision=auau200,filetype=daq_reco_mudst' -limit 10 /dante3/starprod/reco/productionCentral/FullField/P02ge/2001/321::st_physics_2321030_raw_0102.MuDst.root /dante3/starprod/reco/productionCentral/FullField/P02ge/2001/321::st_physics_2321003_raw_0127.MuDst.root /eliza12/starprod/reco/productionMinBias/FullField/P05ic/2004/030::st_physics_5030114_raw_1010013.MuDst.root /eliza12/starprod/reco/productionMinBias/FullField/P05ic/2004/030::st_physics_5030114_raw_1010022.MuDst.root /eliza12/starprod/reco/productionMinBias/FullField/P05ic/2004/030::st_physics_5030114_raw_1020018.MuDst.root

  9. Define an Analysis Task • Examples: • Multiplicity Distribution • ~Probability to find events with Nch tracks. • Nch: number of charged particles in the event (typically, per unit rapidity at midrapidity). • pT distribution of charged tracks for all events. • ~Probability to find a track with a given pT.

  10. The “Maker” framework • “Makers” are a way to standardize the way we do analysis: • All have to “prepare” or initialize • e.g. book histograms and trees • All do something every event • e.g. calculate or obtain distributions of interest • All have to clean up when the job is done • e.g. write the histograms

  11. Example Maker code: • In PDSF: • /auto/pdsfdv39/starspec/pdsfdv34/starspec/calderon/tutorials/StRoot/StMuDstExampleAnalysisMaker • All Makers live under a directory called StRoot • Compilation of the analysis code is done in same directory where StRoot directory (or link) is found • cons +StMuDstExample • Running is done in same directory where compilation was done. Example in StRoot/macros/examples/ • root4star –b –q ‘RunMuDstExample.C(500)'

  12. Plotting the results • Open the output file (dummyFile00.root) in root. Can issue C++ commands on the root classes interactively. • Set a sensible color scheme • gStyle->SetPalette(1,0); • Create canvases (TCanvas) • TCanvas* cnv1 = new TCanvas(“cnv1”,”multiplicity”,600,600); • For drawing histograms: • TH1::Draw() • mMult->Draw(); • Can change line color, width, style • mMult->SetLineColor(2); • mMult->SetLineWidth(3); • mMult->SetLineStyle(11); • Can draw markers • mMult->SetMarkerStyle(20); • mMult->Draw(“P”); • For reproducibility, can also put all the commands into a macro, and just execute the macro: • .x plotMultExample.C

  13. Analyzing Example: Simulation, Step I • Generate events of interest • e.g. Lambda_c, Upsilon, J/Psi particles according to a distribution • e.g. use event generators • PYTHIA • HERWIG • HIJING • NEXUS • AMPT • MPC • For large datasets, request is done officially to STAR simulation (Maxim Potekhin, simulation leader)

More Related