The document presents work on the MIDAS project which aims to identify particle masses using multiple sampling. It outlines results from initial MATLAB simulations showing electrons can be distinguished from muons and protons below 500 MeV. A Geant4 simulation using the SETA environment was also developed to model the TRASGO detector in more detail. Further simulations are needed but combining velocity, chi-squared values with additional information like timing may allow ambiguous particles to be discriminated.

1. MIDAS: Identifying particle masses with TRASGOS
Teresa Kurtukian-Nieto
CEN Bordeaux-Gradignan
Santiago de Compostela, February 5th 2010

2. Outline
MIDAS: MultisamplIng iDentification of pArticleS
Matlab simulation: first results
Geant4 simulation:
SETA: Simulation Environment for TrAsgo
Summary and outlook
Teresa Kurtukian Nieto, CENBG 2nd Workshop TRASGO Project February 5th 2010 2

3. MIDAS:
MultisamplIng iDentification of pArticleS
Teresa Kurtukian Nieto, CENBG 2nd Workshop TRASGO Project February 5th 2010 3

4. MIDAS:
MultisamplIng iDentification of pArticleS
Teresa Kurtukian Nieto, CENBG 2nd Workshop TRASGO Project February 5th 2010 4

5. Matlab simulation: first results
Teresa Kurtukian Nieto, CENBG 2nd Workshop TRASGO Project February 5th 2010 5

6. Matlab simulation: first results
Teresa Kurtukian Nieto, CENBG 2nd Workshop TRASGO Project February 5th 2010 6

7. Matlab simulation: first results
Teresa Kurtukian Nieto, CENBG 2nd Workshop TRASGO Project February 5th 2010 7

8. Matlab simulation: first results
Teresa Kurtukian Nieto, CENBG 2nd Workshop TRASGO Project February 5th 2010 8

9. TRASGO view by SETA
Teresa Kurtukian Nieto, CENBG 2nd Workshop TRASGO Project
D. Gonzalez Diaz2010
February 5th 9

10. Geant4 simulation SETA
Teresa Kurtukian Nieto, CENBG 2nd Workshop TRASGO Project February 5th 2010 10

11. Geant4 simulation SETA
Teresa Kurtukian Nieto, CENBG 2nd Workshop TRASGO Project February 5th 2010 11

12. Summary and Outlook
Low-energy electrons give values for the reduced chi-squared much higher
than high-energy muons, even by increasing the thickness of the absorbent or
the material, being possible as a consequence to distinguish muons and
electrons below 500 MeV.
Protons could be identified for the same energy regime, by the measurement
of velocity which is always smaller than the one for muons and electrons. By
increasing the number of active planes it can be possible to cut low-energy
charged particles up to the desired level.
In general, protons, muons and electrons shows clusters at different zones
on the beta-chi-squared plots, however an important overlapping is also
present.
Next steps in this analysis will be to perform a full simulation under Geant4
(SETA) which will allows one to get more realistic results.
Once this analysis on velocity and chi-squared can be correlated with the
arrival time, azimuthal and zenital angles, distance to the core of the shower,
etc, the discrimination between particles in case of ambiguity will be possible
Teresa Kurtukian Nieto, CENBG 2nd Workshop TRASGO Project February 5th 2010 12

13. Thank you
Teresa Kurtukian Nieto, CENBG 2nd Workshop TRASGO Project February 5th 2010 13