Pion Beam Experiment Page

Analysis of exclusive channels we moved to:


This page contains all informations about preparation to pion experiment: physics simulations, beam optics calculations and detector development.

People involved

IPN, Orsay
  • Beatrice Ramstein
  • Hubert Kuc
  • Thierry Hennino
  • Ermias Atomssa
  • Federico Scozzi
TU Muenchen
  • Laura Fabbietti
  • Rafal Lalik
  • Eliane Epple
  • Johannes Siebenson
  • Robert Muenzer
  • Joana Wirth
  • Tobias Schmitt
  • Ludwig Maier
GSI Darmstadt
  • Wolfgang Koenig
  • Jerzy Pietraszko
  • Michael Traxler

Pion Beam Physics

Pion Beam Optics

The good starting point is the paper

Design and commissioning of the GSI pion beam.

Simulation of pion beam optics

Pion beam - TDR - Document with the status of the preparation of the pion tracker and evaluation of the beam optics.

  • Git repository (read only access) can be fetch from
    or from the git web interface.
    For RW access to the git repository, please send your ssh key (which will you use for the ssh connection) to Rafal Lalik. If you are not familiar with the git you can download the git repository with the following command:
    git clone git://saturn.e12.ph.tum.de/HADESCerberosTDR.git
    edit your changes and send edited files to Rafal Lalik by e-mail.

Pion Beam Tracker Development

This page contains information about development of Pion Tracker detector for HADES pion experiments.

Cerberos info

Detector and DAQ Miscellaneous

Tests results


Counting rates & Physics predictions

Counting rate estimates for different channels and possible beam request presented at the HADES CM in november 2012

Predictions for two pion production from Bonn-Gatchina group (curtesy of a.Sarantsev)
  • download root macro (attached and look into plots)
pipi_hades.cpp: root macro for 2pi
utility_general.cpp: utility_general.cpp

Beam time GSI 1.07-16.07.2014

  • two pion count rates from preliminary analysis on date 186 (46 MLN of events roughly 7 hours of running, 217 files) PionBeamGSI2014
  • Proton-pion and two-pion correlations from 2 MLN events collected for 0.7 GeV /c pions on Carbon and Polyethylene targets
07GeVCarbon.pdf: proton-pion and 2pion correlations from 0.7GeV/c pion induced reactions

Beam time GSI 18.08-11.09.2014

Beam energy scan around second resonance region. * indicate that at this momentum Cristal Ball@ BNL took also data in pi-p -> pi0pi0 n channel- PHYSICAL REVIEW C 69, 045202 (2004) -(complementary channel - very important for PWA analysis because in this channel rho meson MUST be absent). At central value of our measurement 0.69 GeV /c we will have enough statistics to make additional 2 bins in momentum +- 2% (0.703 and 0.677 GeV /c b.t.w also measured by CB)

Runs with PE target

pion momentum [GeV/c] Centrum of mass Energy Number of events
0.8 1.556 >= 40 MLN (measured 52.4 MLN)
0.748* 1.526 >= 40 MLN (measured 76.5 MLN)
0.69 * 1.49 measured 774.7 MLN
0.656* 1.468 >= 40 MLN (measured 42.4 MLN)
0.612* 1.441 >= 40 MLN
For bakcground subtraction we need at least same statistics (40 MLN) in each momenty bin with Carbon target.

Thus, in total we need at least 9 good shifts (4 momentum scan and 5 carbon) to cover this program.

Runs with C target

pion momentum [GeV/c] Centrum of mass Energy Number of events
0.8 1.556 measured 41.2 MLN
0.748* 1.526 measured 42.2 MLN
0.69 * 1.49 measured 115.7 MLN
0.656* 1.468 measured 41.9 MLN
0.612* 1.4not41 measured 47.8 MLN

Dilepton analysis (Sept 2017):

  • 3-dim acceptance and efficiency matrices calculated from GEANT4 simulations of electrons/positrons with flat momentum distributions (p<700 MeV /c).X=theta (deg) 45 bins (0.,90.) ;Y=phi (deg) 90 bins (0.,360.); Z=p (MeV /c) 40 bins (0.,800.);
  • data and simulation (using PLUTO ρ and old RICH digitizer) events for extraction of Spin Density Matrix coefficients (Andrey's procedure)
  • tar file with Andrey's code. Instructions can be found in the README.
  • files with events generated with the GSI model (old version) in 4π N1440,N1520,N1520+N1440,N1520-N1440: original files and files with appropriate format to be used by the fitting code. (Note: model files not available anymore)
  • Federico's talk in ECT 2017 F_Scozzi_trento.pdf: F_Scozzi_trento.pdf

Dilepton cocktail (Sept 2017):

  • dilepton cocktail based on incoherent sum of contribution of known cross sections: PLUTO simulation. Normalization and C subtraction: pion_dilep_normXS.pdf

Pion beam normalization (Sept 2017):

One pion and two pion production (Sept 2017):

More complete information with start and end run numbers, detailed statistical information can be found here:


-excell table with run info data_august2014.xlsx

On-line analysis of the beam momentum scan

Liquid Hydrogen target

A repair action on the LH2 target is underway. Tests are being conducted with a proton beam at the Orsay Tandem. See the presentation THennino_pactandem_140213.pdf at the PAC meeting on the 14/2/13.

The test at the Orsay tandem was conducted from 6th to 8th of january 2014. See the presentation TEST_LH2_tandem_150114.pdf

segmented Start Detector

The Start detector consists of 9 diamonds each with 4 pads. In runs with the LH2 target, it will be located 40 cm upstream of the target center and about 80 cm inside the support pipe (downstream) of the target. The estimated heat injection after shielding start detector and support rods with aluminized mylar foils (low emissivity of 5% each layer) will amount to several 10 mW. The effect of this heat injection onto liquid stability will be tested as soon as the LN2 target is operational.
Some details of the design can be found in PionBeamStartDetector.pdf. It will be updated regularly.

I Attachment Action Size Date Who Comment
07GeVCarbon.pdfpdf 07GeVCarbon.pdf manage 233 K 2014-07-16 - 19:15 PiotrSalabura proton-pion and 2pion correlations from 0.7GeV/c pion on Carbon
Efficiency.rootroot Efficiency.root manage 787 K 2017-09-19 - 17:28 BeatriceRamstein efficiency matrices for electrons and positrons
F_Scozzi_trento.pdfpdf F_Scozzi_trento.pdf manage 2 MB 2017-10-18 - 11:52 PiotrSalabura  
GSI2012.pdfpdf GSI2012.pdf manage 2 MB 2013-02-26 - 23:33 BeatriceRamstein presentation at the HADES CM in nov. 2012
GSImodel_oldfiles_saranformat.zipzip GSImodel_oldfiles_saranformat.zip manage 14 MB 2017-09-29 - 17:40 BeatriceRamstein  
Lara_Hijazi.Master2-NPAC.pdfpdf Lara_Hijazi.Master2-NPAC.pdf manage 1 MB 2014-08-25 - 11:46 BeatriceRamstein Master2 internship presentation of Lara Hijazi (analysis of May2014 test beam data)
PHN-NQM-HADES-09.pdfpdf PHN-NQM-HADES-09.pdf manage 115 K 2012-11-26 - 10:28 ElianeEpple GSI Report 2010 about CERBEROS
PHN-NQM-HADES-14.pdfpdf PHN-NQM-HADES-14.pdf manage 169 K 2012-11-26 - 10:31 ElianeEpple GSI Report 2011 - Status of the Pion Beam Tracker
PHN-NQM-HADES-15.pdfpdf PHN-NQM-HADES-15.pdf manage 87 K 2012-11-26 - 10:31 ElianeEpple GSI Report 2011 - Simulation for the L1405 in pion reactions
PionBeamCalibration_Apr26.pdfpdf PionBeamCalibration_Apr26.pdf manage 355 K 2014-05-14 - 10:25 BeatriceRamstein preliminary analysis of APR2014 measurements
PionBeamStartDetector.pdfpdf PionBeamStartDetector.pdf manage 189 K 2013-04-03 - 10:41 WolfgangKoenig Pion Beam Start Detector design & simulation
TEST_LH2_tandem_150114.pdfpdf TEST_LH2_tandem_150114.pdf manage 833 K 2014-01-15 - 15:11 ThierryHennino result of the LH2 test at the Orsay tandem
THennino_pactandem_140213.pdfpdf THennino_pactandem_140213.pdf manage 760 K 2013-02-15 - 10:08 ThierryHennino LH2 target test proposal
acceptance_electrons.rootroot acceptance_electrons.root manage 313 K 2017-09-19 - 17:29 BeatriceRamstein acceptance matrix for electrons
acceptance_positrons.rootroot acceptance_positrons.root manage 329 K 2017-09-19 - 17:29 BeatriceRamstein acceptance matrix for positrons
calibration_pionBeam.pdfpdf calibration_pionBeam.pdf manage 850 K 2018-11-25 - 16:03 BeatriceRamstein summary of observations of momentum shifts at p=0.69 GeV/c
chamber.pdfpdf chamber.pdf manage 831 K 2013-03-08 - 14:42 LauraFabbietti Solid Work drawings of the final detector assembly
correlationY1Y2.pdfpdf correlationY1Y2.pdf manage 758 K 2018-11-25 - 15:48 BeatriceRamstein Y1*Y2 correlation: comparison exp. and simul.
data_august2014.xlsxxlsx data_august2014.xlsx manage 11 K 2014-09-11 - 10:47 ThierryHennino data summary september 2014
epjconf_meson2016_witek.pd.pdfpdf epjconf_meson2016_witek.pd.pdf manage 174 K 2017-10-18 - 12:00 PiotrSalabura Meson2016_proceedings
hades_beam_settings.pdfpdf hades_beam_settings.pdf manage 60 K 2014-04-30 - 20:51 PiotrSalabura settings of magnets and file names for the measurement of the beam transmission (pdf and excel file)
hades_beam_settings.xlsxxlsx hades_beam_settings.xlsx manage 10 K 2014-04-30 - 20:53 PiotrSalabura  
pion_beam_epem.pdfpdf pion_beam_epem.pdf manage 297 K 2014-08-27 - 19:34 WitoldPrzygoda Pion beam e+e- (ver 27.08.14 evening)
pion_dilep_normXS.pdfpdf pion_dilep_normXS.pdf manage 985 K 2017-10-18 - 12:35 PiotrSalabura cocktail
pion_exp_target_consid.pptxpptx pion_exp_target_consid.pptx manage 1 MB 2014-09-02 - 09:56 PiotrSalabura consideration on targets for pion experiment and update on count estimates
pion_intro_hades.pptppt pion_intro_hades.ppt manage 5 MB 2014-09-02 - 09:50 PiotrSalabura introduction to HADES pion physics programme
pions_from_august.pdfpdf pions_from_august.pdf manage 299 K 2014-08-30 - 09:15 PiotrSalabura one,two pion events from day 232/233-pdf file
pions_from_august.pptxpptx pions_from_august.pptx manage 248 K 2014-08-30 - 09:17 PiotrSalabura one,two pion events from day 232/233
piontracker-30-08-2014.pdfpdf piontracker-30-08-2014.pdf manage 1 MB 2014-09-01 - 18:11 JoanaWirth PionTracker:Hitfinder
piontracker_v2_joana_0112205.pdfpdf piontracker_v2_joana_0112205.pdf manage 5 MB 2018-11-25 - 15:54 BeatriceRamstein  
pipi_hades.cppcpp pipi_hades.cpp manage 6 K 2014-03-12 - 15:09 PiotrSalabura root macro for 2pi
pt_0.pngpng pt_0.png manage 18 K 2014-07-06 - 19:54 KirillLapidus it is very preliminary
salabura_ect_PION.pdfpdf salabura_ect_PION.pdf manage 1 MB 2017-10-18 - 12:03 PiotrSalabura presentation ECT
summary_data_300414.xlsxxlsx summary_data_300414.xlsx manage 11 K 2014-05-01 - 13:35 ThierryHennino summary of settings for transport coefficients measurements
utility_general.cppcpp utility_general.cpp manage 2 K 2014-03-12 - 15:11 PiotrSalabura  
witek_cm_2016_paris.pdfpdf witek_cm_2016_paris.pdf manage 582 K 2017-10-18 - 11:56 PiotrSalabura Witek prezentation in CM2016 Paris
Topic revision: r98 - 2023-05-15, BeatriceRamstein
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