Pion Beam Experiment Page

Analysis of exclusive channels we moved to:

https://hades-wiki.gsi.de/foswiki/bin/view/Physics/ExclusivePWG

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

• piontracker-30-08-2014.pdf: status pion tracker hitfinder (only using time cuts)

Pion Beam Optics

• summary_data_300414.xlsx: summary of settings for transport coefficients measurements
• hades_beam_settings.pdf: settings of magnets and file names for the measurement of the beam transmission (pdf and excel file)
• hades_beam_settings.xlsx: hades_beam_settings.xlsx
• PionBeamCalibration _Apr26.pdf: preliminary analysis of Apr 26 and Apr30 measurements
• Lara_Hijazi.Master2-NPAC.pdf: presentation of Master2 internship of Lara Hijazi (analysis of May14 test beam data)
• correlationY1Y2.pdf: do simulations reproduce y1*y2 correlation ?
• piontracker_v2_joana_0112205.pdf: correlation between pion momentum from tracker and from HADES
• calibration_pionBeam.pdf: summary of observations of momentum shifts

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.

• A secondary Pion Beam for the HADES Experiment - Technical Design Report

• Git repository (read only access) can be fetch from
  git://saturn.e12.ph.tum.de:HADESCerberosTDR.git
  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.

• ZIP archive - recent version: http://transfer.ktas.ph.tum.de/papers/piontracker/HADES_Cerberos_TDR.zip

Pion Beam Tracker Development

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

Cerberos info

Detector and DAQ chamber.pdf: Solid Work drawings of the final detector assembly Silicons

Miscellaneous Detector cooling

Tests results

• Test beam in Juelich, Dec 2013

Meetings

• Pion beam Task Group meetings

Counting rates & Physics predictions

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

• See the presentation GSI2012.pdf

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

• pion_intro_hades.ppt: introduction to HADES pion physics programme

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

• and on PolyEthylene
• results from online strangeness analyses PionBeamJul14StrangenessOnline

• pion_exp_target_consid.pptx: consideration on targets for pion experiment and update on count estimates

Beam time GSI 18.08-11.09.2014

• First results from 12 hours run with 0.69 GeV /c pions on PE target: one pion and two pion channels: pπ- , pπ-π0, nπ-π+
• pions_from_august.pptx: one,two pion events from day 232/233
• pions_from_august.pdf: one,two pion events from day 232/233-pdf file
• piontracker-30-08-2014.pdf: pion momentum reconstruction from pion tracker
• pion_beam_epem.pdf (updated 27.08.2014 evening) e+e- reconstruction for pion beam with PE target : PionBeamAug14Dileptons

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.);
  • acceptance_electrons.root and acceptance_positrons.root : geometrical acceptance matrices for electrons and positrons for true values of theta,phi,p .
  • Efficiency.root: contains efficiency matrices for electrons and positrons for the old RICH digitizer defined as N(p_rec,theta_rec,phi_rec)/ N(p_true, theta_true, phi_true)
• 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):

• elastic scattering : Final results : Witek presentation in CM2016 Paris witek_cm_2016_paris.pdf:

One pion and two pion production (Sept 2017):

• Witek's report (Meson'2016) : epjconf_meson2016_witek.pd.pdf: Meson2016_proceedings
• two pion production -Partial Wave Analysis : status ECT Trento 2017: salabura_ect_PION.pdf: presentation ECT

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

http://web-docs.gsi.de/~webhades/media/logbook/aug14/collected_statistic_aug14.html

-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.

• Lara_Hijazi.Master2-NPAC.pdf: Master2 internship presentation of Lara Hijazi (analysis of May2014 test beam data

• F_Scozzi_trento.pdf: F_Scozzi_trento.pdf

• pion_dilep_normXS.pdf: simulation and normalization