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Physics and Simulation Studies

ILC Simulations and Physics Studies at Fermilab--01/2007 update

main ILC Detector Simulation page
version 0.31, John Yoh, 01/05/07
Changes --Adding the instructions for 2 physics example tutorial (prelim)
New --Fermilab computer division has a new ILC simulation support group--contact Mark Fischler mf@fnal.gov for more information--and tell him if you are doing work on ILC simulation or physics studies
Please send all comments, addendum, suggestions, etc. to johny@fnal.gov and mf@fnal.gov mf@fnal.gov

INDEX

  1. Introduction--overview of ILC
  2. Available Software Framework/Tools
  3. Getting started at Fermilab
  4. (New) Tutorials on sample projects
  5. Proposed Projects
  6. Currently ongoing projects
  7. Miscellaneous

(1) Introduction--overview of ILC

ILC (International Linear Collider) is a ongoing Global initiative to design, get approval from various governments, construct and operate an ILC by 2015-2017.

ILC will be a linear (20 mile long) collider of electrons and positrons beams, with a total Energy of 500 Gev, though future upgrade to 1 TeV may be possible.

The Goal of such a collider is to

  1. Discover the secrets of the Terascale--- study the Higgs particle (expected to be discovered in the forthcoming LHC collider at Cern, Geneva, Switzerland, due to come online in 2007)
  2. Shed light on dark matter
  3. Reveal the Ultimate unified theory

These are from Joe Lykken's talk on Physics case for ILC(pdf)

more detailed information on ILC current efforts are in Talks from July 2006 Vancouver Linear Accelerator workshop
ILC newline --weekly news letter from the ILC GDE--Global Design Effort--The GDE, headed by Barry Barish working with all the interested Physicists and accelerator people, is expected to arrived at a conceptual design--The ILC RDR (Reference Design Report) and the DCR (Detector Concept Report) both due early 2007--see GDE Report at Vancouver workshop

Some useful information about ILC and general issues of physics studies can be seen in Useful ILC terminologies, Acronyms, etc.

For detailed advanced description of various ILC physics objectives (Higgs, SUSY, Top, GigaZ, etc.), see the 480 page "book" ILC Physics Resource guide for Snowmass 2001 ---(individual chapters can be downloaded separately--note that this is from 2001, so, some of machine information is outdated--as well as some of the Physics studies results) -- A more recent review of ILC physics objectives (to be inserted later) see also ALCPG (American Linear Collider Physics Group and 2000 Linear Collider Physics Studies at Fermilab

(2) Available Software Framework/Tools

Many Physicists interested in ILC have contributed software and studies, starting more than 10 years ago. For an overview of the Simulation studies, see Mark Thomson's review at the 4/06 Cambridge ILC software and Physics meeting Where are we now and what next

In particular, take a look at slide 4--which give a list of software framework and tools available for ILC simulation and Physics studies.

Much of the current effort at Fermilab involve using SLIC/org.lcsim/ LCIO/JAS3, as well as confluence. Some projects just use GEANT4.

Some other potentially useful web sites include
lcsim getting started
SLIC
ilcsim information ilcsim is the Fermilab server for ilc simulation
lcsim--Linear Collider Simulation

Datasets for ILC physics studies contains lots of datasets (simulated) which one can use for physics studies--reconstruction software are being developed right now and may be needed.

(3) Getting started at Fermilab

You can test drive some of the software by following the instructions on lcsim getting started--using JAS3 with the LCSIM Event Browser or the Event Display plug-in, you can look at some events from a file generated at SLAC. You can then try doing some simple analysis.

There are 2+ (perhaps complementary) ways to work on ILC simulation studies at Fermilab

  1. Use your personal workstation or laptop to run JAS3 and do program development, testing on a few events--you need to download Java, etc. from slac--so, broadband is required.
  2. use the ilcsim server (see ilcsim instructions , or contact Lynn Garren at garren@fnal.gov to get an account) and run your jobs there--note that you would need a FNAL account with kerboros password. There may also be some additional issues with accessing ilcsim from outside Fermilab..
  3. In addition, you can use the grid to run batch jobs--in case you need more cpu than available in the previous options.

NOTE (on using your laptop or workstation)

  1. You will need about 1 GB of disk space, and at least 15-30 minutes to set up the JAS3 program.
  2. You will need to load both JDK and Java Runtime (see the links)
  3. (At least for me) To compile the sample driver program, you need to change the path in JAS3 for view-->perferences-->Java-->compiler to the right area on your disk (in my case, it was C:\Program Files\Java\jdk1.5.0_07\bin\javac.exe )--otherwise it will fail to compile
    You can then run the program and see some sample histograms
  4. (New) You can also test drive some of the example tutorial listed below in section 4.

(4)Physics example Tutorials--updated 12/21/06

2 example tutorials (in beta test) provided--more later If you wish to help provide more useful example tutorials , please contact us

We are providing several step-by-step tutorials for any beginner to go through a physics example analysis/simulation --and will add more later. Currently, these 2 example tutorials utilize particle level analysis--no simulation or reconstruction is being used (we hope to provide sample tuutorial incorporating FASTMC or even full simulation/reconstruction later).

  1. The following 2 projects will utilize JAS3 using datasets (generated by our SLAC colleagues) of e+e---> ZH --> with a Higgs mass of 120 GeV at a collision energy of 350 or 500 GeV--suitable for using your own workstation or laptop.
  2. First, you must load the latest Java dk and rt, then the JAS3 package from slac --see lcsim getting started--follow the links to install Java and JAS3 + plugins
  3. (1) Higgs recoil mass analysis ZH --> Dimuons + Higgs, with recoil mass (Higgs) calculation and various histograms
    --find all high Pt muonss above some thrshold;
    for events with 2 such muonss with a mass near the peak, provide a distribution of recoil mass off the dimuon from Z. This is a simple study which was done by many people in the past. (Thanks to Norman Graf for providing this example)
  4. (2) Higgs into diphoton example ZH --> Z + H->Diphotons
    Look for 2 photons E > 20, |Cos (Theta)| <0.9, etc.
    with selection criteria to reduce backgrounds
    Signal and Background dataset provided -- for more statistics on background, please contact John Yoh ( johny@fnal.gov )
  5. Some general comments on Higgs and Higgs examples

(5)Proposed Projects--INCOMPLETE

Here's a partial list of potential studies projects (to be added later)--name included people who are working on these projects (), or those who are interested []

PHYSICS STUDIES PROJECTS

  1. Understand the potential gamma-gamma backgrounds to physics proecesses such as WH, ZH, etc. [Yoh]
    See Considerations on Physics and Non-Physics Backgrounds for ILC

Simulation Studies projects

  1. Understand Calorimetry resolution--how to improve it (Para, Yu, Wenzel)

(6)Currently ongoing projects

Many Simulation projects are ongoing at Fermilab currently--(if you are working on something, please provide an .html web page and a short description and I will add a link below). If some particular project interest you, please contact the appropriate person(s)--here's a partial list (to be updated)

  1. Muon id studies, algorithm development, reconstruction (Caroline Milstene, Gene Fisk, Adam Para)-- see Muon id studies
  2. Super-Symmetry studies--(Milstene, Freitas, Carrena, Finch, Sopczak, Nowak) see SUSY
  3. Si vertex tracking (Caroline Milstene, Sopczak, Finch, DeMarteau) see Vertex detector
  4. Calorimetry studies--using GEANT (Adam Para, Eiko Yu, Hans Wenzel)

(7)Miscellaneous