Difference: PiENu (1 vs. 9)

Revision 92013-04-25 - DanProtopopescu

Line: 1 to 1
 
META TOPICPARENT name="DanProtopopescu"

PiENu

Line: 26 to 26
 The MC code was obtained from svn (pienu02.triumf.ca/pienumc/trunk) and unpacked on the UI. Specific versions of CLHEP (2.0.4.2) and Geant4 (4.9.0.3.p02) were installed in the user directory in ~/packages/. Detailed download and compilation instructions for CLHEP, Geant4 and the main pienu code were provided by Aleksey Sher via email (May 2011).
Changed:
<
<

Monte Carlo

>
>
Our MC code version is slightly modified to record the angles and energies of the Bhabha-scattered e+ and e-. During our analysis we have discovered that a spurious production cut was forgotten in the code, and this was introducing, among others, incorrectly high (2 MeV) energy thresholds for the Bhabha-scattered electrons. This is now corrected everywhere.
 
Changed:
<
<
MC run using recommended settings, 100k events (to check):
>
>

Simulation and Reconstruction

 
Changed:
<
<
>
>
Pienu or Pimunu events are simulated with pienu, and a Root output is produced. This output is subsequently processed with MC2Data, which does the reconstruction and produces a Root file with additional information. The reconstructed data is then analysed with various macros that were custom-written for our study.
 
Changed:
<
<

Bhabha events tagging

>
>

Bhabha events tagging in MC

Bhabha scattering events are flagged in SteppingAction, by assigning to EBh the energy of the positron if the process involved at a certain step is "eIoni" and the volume where this occurs is "Target":

 
Deleted:
<
<
In MC, this is done via a code snippet added by Chloe in SteppingAction.cc:
 
Deleted:
<
<
//Chloe's addition (in SteppingAction.cc)
  if (theParticleName == "e+" && thePostVolume == "/pienu/Target" && theProcessName == "eIoni") {
Changed:
<
<
runAction->SBhabha(postEnergy); // G4cout << postEnergy/MeV << G4endl;
>
>
runAction->TgtBhabha(postEnergy);
  }
Deleted:
<
<
However, this only selects Bhabha scattering events happening in the target volume.
 
Changed:
<
<

Reproducing plots from Chloe's thesis

>
>
The energies and momenta of the initial positron and the outgoing positron and electron are recorded with the following conditionals:

    if(theParticleName == "e+"
       && thePostVolume == "/pienu/Target"
       && theProcessName == "eIoni") {
      runAction->PositronFromBhabha(postEnergy, postMomentum);
      runAction->PositronPreBhabha(preEnergy, preMomentum);  
    }

    if(theParticleName == "e-" 
       && thePostVolume == "/pienu/Target"
       && theCreatorProcessName == "eIoni"
       && theTrack->GetCurrentStepNumber()==1) {
      runAction->ElectronFromBhabha(prePosition, preEnergy, preMomentum);        
    }

The "eIoni" physics processes are implemented in module G4MollerBhabhaModel.cc from the Geant4 MC simulation package.

Events such tagged were studied to understand energy and angular distributions of the Bhabha-scattered e- and e+ and compare them with 'non-Bhabha' events.

Analysis

The first step was to validate our software by reproducing all plots done with MC from Chloe's thesis. The second step was to try to reproduce data results from Chloe's thesis with our MC (adding radiative effects, pileup etc. if necessary). We have satisfactorily achieved these steps.

 
Changed:
<
<
The data tree produced by MCtoData contains numerous new branches, which can be useful for this analysis. A first step is trying to identify these branches and reproduce some of the most important plots from Chloe's thesis. These PDFs contain our plots:
>
>
In terms of understanding the energy and angular distributions of the Bhabha-scattered e- and e+, we have prepared a report (attached to this wiki) for the PiENu collaboration. Since the Bhabha correction to the tail correction is not directly measurable, the plan is to estimate it from the MC and then validate the MC by comparing a measurable Bhabha effect with data.
 
Changed:
<
<
The ROOT macros used to draw these plots are attached here.
>
>
Some of the ROOT macros used are attached here.
 
META FILEATTACHMENT attachment="TalkINPC.pdf" attr="" comment="INPC 2010 talk by Chloé Malbrunot" date="1336144134" name="TalkINPC.pdf" path="TalkINPC.pdf" size="3207320" stream="TalkINPC.pdf" tmpFilename="/usr/tmp/CGItemp16539" user="DanProtopopescu" version="1"
META FILEATTACHMENT attachment="PIENU_proposal.pdf" attr="" comment="PIENU Proposal" date="1336144271" name="PIENU_proposal.pdf" path="PIENU_proposal.pdf" size="390839" stream="PIENU_proposal.pdf" tmpFilename="/usr/tmp/CGItemp16616" user="DanProtopopescu" version="1"

Revision 82013-02-06 - DanProtopopescu

Line: 1 to 1
 
META TOPICPARENT name="DanProtopopescu"

PiENu

Line: 9 to 9
 

PPE People

Changed:
<
<
Currently, David Britton and DanProtopopescu are directly involved in this experiment.
>
>
Currently, David Britton, DanProtopopescu and Ian Skillicorn are contributing to this experiment.
 

Shift Schedule

Revision 72012-08-09 - DanProtopopescu

Line: 1 to 1
 
META TOPICPARENT name="DanProtopopescu"

PiENu

Line: 11 to 11
  Currently, David Britton and DanProtopopescu are directly involved in this experiment.
Added:
>
>

Shift Schedule

Available here: http://pienu02.triumf.ca/pienu_shifts/index.php

 

Documentation

Revision 62012-06-27 - DanProtopopescu

Line: 1 to 1
 
META TOPICPARENT name="DanProtopopescu"

PiENu

Line: 29 to 29
 
Changed:
<
<

Tagging Bhabha events

>
>

Bhabha events tagging

In MC, this is done via a code snippet added by Chloe in SteppingAction.cc:

//Chloe's addition (in SteppingAction.cc)
    if (theParticleName == "e+" 
        && thePostVolume == "/pienu/Target" 
        && theProcessName == "eIoni") {
        runAction->SBhabha(postEnergy);
     // G4cout << postEnergy/MeV << G4endl;
    } 
However, this only selects Bhabha scattering events happening in the target volume.

Reproducing plots from Chloe's thesis

The data tree produced by MCtoData contains numerous new branches, which can be useful for this analysis. A first step is trying to identify these branches and reproduce some of the most important plots from Chloe's thesis. These PDFs contain our plots:

The ROOT macros used to draw these plots are attached here.

 
Deleted:
<
<
... Will be documented along the way ...
 
META FILEATTACHMENT attachment="TalkINPC.pdf" attr="" comment="INPC 2010 talk by Chloé Malbrunot" date="1336144134" name="TalkINPC.pdf" path="TalkINPC.pdf" size="3207320" stream="TalkINPC.pdf" tmpFilename="/usr/tmp/CGItemp16539" user="DanProtopopescu" version="1"
META FILEATTACHMENT attachment="PIENU_proposal.pdf" attr="" comment="PIENU Proposal" date="1336144271" name="PIENU_proposal.pdf" path="PIENU_proposal.pdf" size="390839" stream="PIENU_proposal.pdf" tmpFilename="/usr/tmp/CGItemp16616" user="DanProtopopescu" version="1"
Added:
>
>
META FILEATTACHMENT attachment="Plots-2012-06-26.pdf" attr="" comment="Plots reproducing figures 1.2, 5.1 and 5.19" date="1340795222" name="Plots-2012-06-26.pdf" path="Plots-2012-06-26.pdf" size="1055200" stream="Plots-2012-06-26.pdf" tmpFilename="/usr/tmp/CGItemp20782" user="DanProtopopescu" version="1"
META FILEATTACHMENT attachment="macros.tgz" attr="" comment="Analysis macros (initial versions)" date="1340795449" name="macros.tgz" path="macros.tgz" size="4122" stream="macros.tgz" tmpFilename="/usr/tmp/CGItemp20416" user="DanProtopopescu" version="1"

Revision 52012-06-15 - DanProtopopescu

Line: 1 to 1
Changed:
<
<
META TOPICPARENT name="DanProtopopescuLeftBar"
>
>
META TOPICPARENT name="DanProtopopescu"
 

PiENu

The PIENU experiment at TRIUMF (Vancouver, Canada) aims at precisely measuring the pion decay branching ratio (π+ → eν)/(π →μν).

Revision 42012-06-15 - DanProtopopescu

Line: 1 to 1
 
META TOPICPARENT name="DanProtopopescuLeftBar"

PiENu

Changed:
<
<
The PIENU experiment aims at precisely measuring the pion decay branching ratio (π+ → eν)/(π →μν).
>
>
The PIENU experiment at TRIUMF (Vancouver, Canada) aims at precisely measuring the pion decay branching ratio (π+ → eν)/(π →μν).
 The current experimental value for this ratio is 20 times less precise than the theoretical calculation done within the SM, leaving a large window in which non-standard physics - new interactions or exotic particles - can be involved. Or, on the other hand, improved precision that would confirm the SM would set tighter constraints on new physics scenarios.

Changed:
<
<

People

>
>

PPE People

  Currently, David Britton and DanProtopopescu are directly involved in this experiment.
Line: 29 to 29
 
Added:
>
>

Tagging Bhabha events

... Will be documented along the way ...

 
META FILEATTACHMENT attachment="TalkINPC.pdf" attr="" comment="INPC 2010 talk by Chloé Malbrunot" date="1336144134" name="TalkINPC.pdf" path="TalkINPC.pdf" size="3207320" stream="TalkINPC.pdf" tmpFilename="/usr/tmp/CGItemp16539" user="DanProtopopescu" version="1"
META FILEATTACHMENT attachment="PIENU_proposal.pdf" attr="" comment="PIENU Proposal" date="1336144271" name="PIENU_proposal.pdf" path="PIENU_proposal.pdf" size="390839" stream="PIENU_proposal.pdf" tmpFilename="/usr/tmp/CGItemp16616" user="DanProtopopescu" version="1"

Revision 32012-05-08 - DanProtopopescu

Line: 1 to 1
 
META TOPICPARENT name="DanProtopopescuLeftBar"

PiENu

Line: 22 to 22
 The MC code was obtained from svn (pienu02.triumf.ca/pienumc/trunk) and unpacked on the UI. Specific versions of CLHEP (2.0.4.2) and Geant4 (4.9.0.3.p02) were installed in the user directory in ~/packages/. Detailed download and compilation instructions for CLHEP, Geant4 and the main pienu code were provided by Aleksey Sher via email (May 2011).
Added:
>
>

Monte Carlo

MC run using recommended settings, 100k events (to check):

 

META FILEATTACHMENT attachment="TalkINPC.pdf" attr="" comment="INPC 2010 talk by Chloé Malbrunot" date="1336144134" name="TalkINPC.pdf" path="TalkINPC.pdf" size="3207320" stream="TalkINPC.pdf" tmpFilename="/usr/tmp/CGItemp16539" user="DanProtopopescu" version="1"

Revision 22012-05-04 - DanProtopopescu

Line: 1 to 1
 
META TOPICPARENT name="DanProtopopescuLeftBar"
Changed:
<
<

PiENu

>
>

PiENu

 
Changed:
<
<
This wiki refers to the PiENu experiment at Triumf: http://pienu.triumf.ca/
>
>
The PIENU experiment aims at precisely measuring the pion decay branching ratio (π+ → eν)/(π →μν). The current experimental value for this ratio is 20 times less precise than the theoretical calculation done within the SM, leaving a large window in which non-standard physics - new interactions or exotic particles - can be involved. Or, on the other hand, improved precision that would confirm the SM would set tighter constraints on new physics scenarios.
 
Changed:
<
<
-- DanProtopopescu - 2012-04-05
>
>

People

Currently, David Britton and DanProtopopescu are directly involved in this experiment.

Documentation

Code compilation

The MC code was obtained from svn (pienu02.triumf.ca/pienumc/trunk) and unpacked on the UI. Specific versions of CLHEP (2.0.4.2) and Geant4 (4.9.0.3.p02) were installed in the user directory in ~/packages/. Detailed download and compilation instructions for CLHEP, Geant4 and the main pienu code were provided by Aleksey Sher via email (May 2011).

META FILEATTACHMENT attachment="TalkINPC.pdf" attr="" comment="INPC 2010 talk by Chloé Malbrunot" date="1336144134" name="TalkINPC.pdf" path="TalkINPC.pdf" size="3207320" stream="TalkINPC.pdf" tmpFilename="/usr/tmp/CGItemp16539" user="DanProtopopescu" version="1"
META FILEATTACHMENT attachment="PIENU_proposal.pdf" attr="" comment="PIENU Proposal" date="1336144271" name="PIENU_proposal.pdf" path="PIENU_proposal.pdf" size="390839" stream="PIENU_proposal.pdf" tmpFilename="/usr/tmp/CGItemp16616" user="DanProtopopescu" version="1"

Revision 12012-04-05 - DanProtopopescu

Line: 1 to 1
Added:
>
>
META TOPICPARENT name="DanProtopopescuLeftBar"

PiENu

This wiki refers to the PiENu experiment at Triumf: http://pienu.triumf.ca/

-- DanProtopopescu - 2012-04-05

 
This site is powered by the TWiki collaboration platform Powered by PerlCopyright © 2008-2020 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback