Whizard

WHIZARD (W, Higgs, Z and respective decays) is a program system designed for the efficient calculation of multi-particle scattering cross sections and simulated event samples. The most up to date version can be found at http://whizard.event-generator.org/. Anyhow, the version currently recommanded is that used to generate the SLAC standard model background sample and can be found at http://confluence.slac.stanford.edu/display/ilc/Standard+Model+Data+Samples.

Pre-Installations

Unfortunately WHIZARD depends on stdhep and O'Mega, which is using the programming language Objective Caml. So if you want to run Whizard on your machine you will first have to install these packages. You can get stdhep from http://cepa.fnal.gov/psm/stdhep/ and ocaml from http://caml.inria.fr/ocaml/index.en.html, respectively. O'Mega should be delivered with newer WHIZARD versions, but otherwise you can find it athttp://theorie.physik.uni-wuerzburg.de/~ohl/omega/. All of them deliver a README and a manual with them, so please have a look at them.

stdhep

This one is uncomplicated. Just follow the instructions in the README.

OCaml

Go into your ocaml directory and type

$ export OCAML='my path to OCaml'/ocaml-3.10.1
$ export PATH=$PATH:'my path to OCaml'/ocaml-3.10.1/bin
$ ./configure --prefix='my path to OCaml'
$ make world

With the --prefix option you can chose where to install ocaml. Now this package should also be fine.

Environment

Before installing WHIZARD, you have to set some path:

$ export F95=/opt/products/ifort/10.1/bin/ifort
$ export LIBS=-lg2c
$ export F77=/opt/products/ifort/10.1/bin/ifort

$ export OCAML=/data/nwattime/LDC_optimization/whizard/source/ocaml-3.10.1
$ export PATH=$PATH:$OCAML/bin

$ export STDHEP=/data/nwattime/LDC_optimization/whizard/stdhep/stdhep-5-06-01/lib/libstdhep.a
$ export FMCFIO=/data/nwattime/LDC_optimization/whizard/stdhep/stdhep-5-06-01/lib/libFmcfio.a

$ export CERNLIB_DIR=/cern/pro/lib

It is important to set the correct paths, otherwise your configuration will fail.

Adaption to the SLAC sample

Some pythia files and beam settings have been changed in the SLAC installation, to optimize whizard for the ILC. Thus, you should copy the a6f directory for fragmentation and guineapig directory for correct beam properties, as well as the whizard-src/user.f90 file from theSLAC page.

Installing Whizard

Now you can configure and afterward install WHIZARD

$ cd whizardDir
$ ./configure --prefix='my_path_to_WHIZARD' "USERLIBS=-L/my_path_to_a6f/a6f/lib/ -linclude"
$ make prg install

/!\ I had serios problems with

they removed some .f95 files that were not restored by make, so don't use them! Better try

if you only changed the whizard.prc or whizard.in files.

Configuration

Whizard is using the CompHEP naming scheme. You can have a look at myWhizard/conf/models/SM.mdl, or MSSM.mdl to find out how to write your particles. Here is a short summary:

Particle

Name

Antiparticle

Mass

Width

Sparticle

Name

Antisparticle

Mass

Width

d-quark

d

D

d-squark

sd1

msd1

wsd1

u-quark

u

U

u-squark

su1

msu1

wsu1

s-quark

s

S

ms

0

s-squark

ss1

mss1

wss1

c-quark

c

C

mc

0

c-squark

sc1

msc1

wsc1

b-quark

b

B

mb

0

b-squark

sb1

msb1

wsb1

t-quark

t

T

mtop

wtop

t-squark

st1

mst1

wst1

electron

e1

E1

me

selectron

se1

mse1

wse1

muon

e2

E2

mmu

smuon

smu1

msmu1

wsmu1

tau-lepton

e3

E3

mtau

stau

stau1

mstau1

wstau1

e-neutrino

n1

N1

e-sneutrino

sne

msne

wsne

µ-neutrino

n2

N2

µ-sneutrino

snmu

msnmu

wsnmu

t-neutrino

n3

N3

t-sneutrino

sntau

msntau

wsntau

gluon

G

gluino

gg

mgg

wgg

photon

A

chargino1

ch1

mch1

wch1

Z-boson

Z

mZ

wZ

chargino2

ch2

mch2

wch2

W-boson

W+

W-

mW

wW

neutralino1

neu1

mneu1

wneu1

Higgs

H

mH

wH

neutralino2

neu2

mneu2

wneu2

The configuration of whizard whould be done in the whizardDir/conf directory. Here you can modify the whizard.prc and whizard.in files to teach WHIZARD the process of interest. Note that WHIZARD expects any input files, e.g. SUSY Les Houche Accord files, to end with .in.

Physics Process

In whizard.prc you can chose which model and processes you are interested in

# The selected model
model MSSM_Grav

# Tag           In      Out                      Method Option
#====================================================================================
test1           e-,e+   A,GR,A,GR  omega  r: 3+4~neu1 && 5+6~neu1  //e+ e- -> 2 Neutralino1 -> 2 gamma + 2 Gravitino
test2           e1,E1   e1,E1                    chep

In case you want to have a look at a minimal supersymmetric standard model process, you have to chose O'Mega as method.

Beam Parameters

The whizard.in file contains informtaion about your beam, input files

 &process_input
 process_id = "test1"         //which process
 input_file = "SPheno"        //SUSY input with path to directory, should end with .in 
 cm_frame = T                      
 sqrts = 500                  //center of mass energy
 polarized_beams = T          //polarized beams is true
 structured_beams = T          
 luminosity = 500             //luminosity in fb-1
 beam_recoil = 

Polarisation is defined as left handed polarisation P_L / right handed polarisation P_R, e.g.

&beam_input
particle_name = 'e1'
polarization  = 0.9 0.1

This would result in an electron beam with 90% left, and 10% righthanded polarisation. Since these are defined as

P_R = (1 + P_e) / 2
P_L = (1 - p_e) / 2

the total electron polaristion P_e results in

P_e = 2*P_R - 1 = 1 - 2* P_L

For this example, we would get -80% electron polarisation.

Running Whizard

Once you have defined your process you can run compile WHIZARD

$ cd whizardDir
$ make clean
$ make proclean
$ make prg install

Now you can chage to the whizardDir/results directory, and run the executable whizard

$ cd ./results
$ ./whizard

The results will be displayed on screen and logged in whizard.test1.out.

/!\ Whizard does not know any non standard modell processes. Therefore, you have to teach it what to do. the process in test 1 will produce 2 neutralinos out of an electron positron collision, that decay into Gravitinos and photons. This option r is only available from whizard 1.51 on. /!\ MSSM_Grav will not be available before whizard 1.93, older versions do not know how to handle Gravitinos

Whizard (last edited 2009-06-16 18:32:15 by localhost)