Transcript Slides

CEDAR
Combined E-science Data Analysis Resource
http://www.cedar.ac.uk/
JetWeb
HepData
 A collaborative project between UCL (London) and IPPP (Durham)
 Funded by PPARC E-Science call in 2003 (independent of the
IPPP) – basically providing funding for 2 RAs (2004-2008).
 Main purpose is to integrate and modernize: JetWeb (UCL) and
HepData (Durham) to provide data archival and presentation with
validation of MCs to experimental data.
 Plus: development tools/environment : HepForge
 Extra: CEDAR tools being used to tune MCs`
 People involved:
UCL: James Monk, Jon Butterworth, Ben Waugh, Emily Nurse……
Durham: Andy Buckley, Mike Whalley, James Stirling
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Why do we need CEDAR/Problems?
 Analysis of the complex events from LHC will require:
MC simulations to be precisely tuned and validated over the full
kinematic range
 JetWeb (UCL –developed at HERA)
allows validation of MCs against a wide range of experimental data.
‘number crunching’ part - HZTool – written in Fortran
contains individual routines for each data set/analysis,
but modern analyses and MCs use C++ !
 HepData (Durham – Reaction database)
~30 year archive of published ‘cross section’ data
could directly provide the input real data to JetWeb
but its Data Base Management System is not suitable
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HepData upgrade
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Old HepData database - Hierarchical -DBMS – Fortran!.
(actually HDBMS suits the data well)
Most modern DBMS are Relational – eq MySQL,Oracle,…
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New HepData version – to use MySQL
Objects – paper,
datasets, axes, bins
points,errors, etc.
Features:
Handles data with a Java object model
Object-relational mapping via Hibernate(DB) and
Castor(external HepML/XML).
New front-end via Java servlets/Tapestry.
Data plotting/export via (J)AIDA.
User input (more direct): HepML/Web Form – authentication?

Migration of old data is underway:
Hdbms <Fortran> flat files <Python> hepml <Castor/Java/Hibernate> New DB
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New HepData Structure
MySQL
hibernate
xml
Java
Java
Servlets
Java
Servlets
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JetWeb upgrade
 System for running MC generators + database of calculated
distributions + comparisons with real data.
 Work on the upgrade primarily at UCL:
o Replace HZTool/HZSteer
with Rivet/RivetGun
o Interface with HepData and
the new Java data model
o Modernize the front end web
interface
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JetWeb screenshots
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Hztool upgrade: Rivet/RivetGun
Robust Independent Validation of Experiment and Theory
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Rivet is essentially a C++ replacement for the Fortran HZTool.
Performs an analysis on a set of particles from a simulated collision.
Combination of tools, analysis handler and analyses.
Outputs histograms for comparison to data from HepData and for
inclusion in JetWeb.
 Release v0.9 on 29/6/2007
 RivetGun interfaces Rivet to the MCs, thereby isolating the
generator steering from Rivet and allowing selection of the
parameters and running the Rivet analyses.
 At present supports FHerwig, FPythia, AlpGen, Sherpa, Herwig++
and Pythia8.
$rivetgun-static –g FPythia –n 5000 –a
-beam1 PROTON –mom1 980
-beam2 ANTIPROTON –mom2 980
-P fpythia.params –l RivetGun:WARN
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HepForge
 Online development environment for free HEP projects
(mainly for CEDAR, but supported)
 For those who want to provide quality multi-use software
for HEP.
 HepForge provides the user with:
Subversion version control (SVN)
Trac issue tracker/wiki/SVN browser
Mailman mailing lists
Downloads management…..
 We don’t provide large volume storage or CPU
resources though!
 Currently about 40 projects, 80 users.
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HepForge
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Tuning with Rivet
(next step from CEDAR- Professor)
 As so often happens, MC parameters are highly correlated, so no
point in tuning one parameter at a time…
 High-dimensional parameter space, n>~10
 Data from LEP, RHIC, HERA, Tevatron.
 Delphi tuning: fit MC results to quadratic in n variables:
 Being reimplemented with Rivet machinery.
 Andy Buckley + Hendrick Hoeth (Wuppertal) + Frank Krauss &
Dresden group
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Tuning with Rivet
 n-dimensional hypercube specifying sample ranges in each
parameter
 generate N random n-vectors in the hypercube
 run RivetGun/Rivet on each set of vectors to produce N Rivet output
files, each of which describes B bins.
 for each bin b fit polynomial function to the N generated values,
using SVD
 Use real data from HepData to compute GoF such as
 Minimise individual functions as:
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CEDAR - Summary
 The HZTool C++ replacement, the Rivet/RivetGun system, now
provides a unified mechanism to re-generate experimental analysis
distributions with various MC generators.
 HepData archive DBMS is being updated and is now used as the
data source for Rivet and JetWeb.
 JetWeb generates and archives Rivet distributions and compares
with data from HepData through a user web interface.
 HepForge accounts are available for suitable projects (current list
include, Herwig++, Sherpa, LHAPDF… ~40 in total
 Rivet will be combined with the Professor tuning system to
automatically tune generators based on Rivet/Hepata mechanisms.
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