Event Generator framework for incorporating Spectroscopy into electro / photoproduction reactions.

Currently hosted on GitHub, please refer to README there for the most up-to-date information.



To run the preinstalled package on cvmfs (natively at the labs or via singularity), first prepare the environment:

source /cvmfs/sphenix.sdcc.bnl.gov/gcc-8.3/opt/sphenix/core/gcc/
source /cvmfs/sphenix.sdcc.bnl.gov/gcc-8.3/opt/sphenix/core/binutils/2.30-e5b21/x86_64-centos7/setup.csh
source /cvmfs/sphenix.sdcc.bnl.gov/gcc-8.3/opt/sphenix/core/root-6.22.02/bin/thisroot.csh
setenv $PATH $EICDIRECTORY/gcc-8.3/bin:${PATH}

This step is necessary because elSpectro requires a newer gcc version than the CentOS7 / SL7 default.

Then in an appropriate directory, for example do:

cp $EICDIRECTORY/PACKAGES/elSpectro/examples/ComparePhaseSpaceto2.C .
elspectro ComparePhaseSpaceto2.C

More examples

All are found in the examples sub-directory ($EICDIRECTORY/PACKAGES/elSpectro/examples on cvmfs).

Examples comparing to simple weighting of TGenPhaseSpace

1) Decay a rho meson to 2 pi

elspectro ComparePhaseSpaceto2.C

2) Decay g+p -> rho(pi+,pi-) p

elspectro ComparePhaseSpaceto3Rho.C

3) Decay g+p -> X(rho(pi+,pi-) , phi(K+,K-) ) p

elspectro ComparePhaseSpaceto5RhoPhi.C
Examples of ElectroProduction

1) EIC e + p -> e’ rho(pi+,pi-) p

elspectro RunRhoProton.C
Examples of ElectroProduction of Jpac amplitudes

1) e + p -> e’ X (Jpsi (e+e-)rho(pi+,pi-)) p

elspectro 'EIC_JPAC_X3872.C("high",5,41,1E33,10)'

Which will run with 5GeV e- energy, 41 GeV proton, Luminosity=10^33 for 10 days

Or with diagnostic histgrams

elspectro 'EIC_JPAC_X3872_Hists.C("high",5,41,1E33,10)'

The first argument can be “high” or “low” giving different parameterisations.

To set luminosity and days change last 2 arguments, e.g. for luminosity 10^33 and 25 days, e- energy 100 and p energy 100 with high energy paramterisation :

elspectro 'EIC_JPAC_X3872.C("high",100,100,1E33,25)'

To just run a fixed number of events leave last argument 0 and nLumi=number of events

elspectro 'EIC_JPAC_X3872.C("high",100,100,1E4)'

2) e + p -> e’ Z(3900) (Jpsi (e+e-) pi+) n

To run with luminosity 10^33 for 25 days

elspectro 'EIC_JPAC_nZc_Hists.C("low",5,41,1E33,25)'

or to just run 1000 events

elspectro 'EIC_JPAC_nZc_Hists.C("low",5,41,1000)'
Examples of MesonEx Quasi-real PhotoProduction

Note forward tagger acceptance can be included with lines like


1) e + p -> e’ X (pi+pi-) p

elspectro MesonEx_p2pi.C

2) e + p -> e’ X (pi+pi+pi-) n

elspectro MesonEx_n3pi.C

3) e + p -> e’ P_c -> Jpsi(e+e-) p

elspectro MesonEx_JpsiPenta.C

Also just does phase space Jpsi, which does not need jpacPhoto, see code for details

Installation from scratch

git clone --recurse-submodules https://github.com/dglazier/elSpectro
cd elSpectro
Set Environment
setenv ELSPECTRO /path/to/elSpectro (or $PWD)
setenv PATH ${PATH}:${ELSPECTRO}/bin
Build with cmake
mkdir build; cd build;
cmake ../
cmake --build . --target install

In the first cmake step, you can specify installation locations with

cmake -DCMAKE_INSTALL_BINDIR=/some/where/bin -DCMAKE_INSTALL_LIBDIR=/some/where/lib