1. Marc Montull Supervisors: Jenny List, Mikael Berggren
Forward Veto reconstruction processor for ILC BeamCal
Marc Montull
Supervisors:
Jenny List, Mikael Berggren
DESY summer students September

2. Outline Goal Motivation SUSY/WMAP results Detecting SUSY
Writing a Marlin processor
My processor
Conclusions
Checks
Marc Montull DESY summer students September

3. Goal TO WRITE MARLIN processor
Marc Montull DESY summer students September

4. Goal TO WRITE THAT DETERMINES MARLIN processor γγ background
Marc Montull DESY summer students September

5. Goal TO WRITE THAT DETERMINES FOR MARLIN processor γγ background
SUSY analysis
Marc Montull DESY summer students September

6. Goal Writing some C++ code that
TO WRITE
THAT DETERMINES
FOR
MARLIN processor
γγ background
WHICH TRANSLATES TO
SUSY analysis
Writing some C++ code that
reconstructs energetic electrons and photons
in the Beam Calorimeter of the ILC
Marc Montull DESY summer students September

7. What’s the γγ background. Why need to detect energetic electrons
What’s the γγ background? Why need to detect energetic electrons? Why in the Beam Calorimeter?
Marc Montull DESY summer students September

8. What’s the γγ background. Why need to detect energetic electrons
What’s the γγ background? Why need to detect energetic electrons? Why in the Beam Calorimeter? Relation with SUSY?
Marc Montull DESY summer students September

9. What’s the γγ background. Why need to detect energetic electrons
What’s the γγ background? Why need to detect energetic electrons? Why in the Beam Calorimeter? Relation with SUSY? What’s a MARLIN processor?
Marc Montull DESY summer students September

10. ILC Let’s start from the beggining
Marc Montull DESY summer students September

11. ILC Let’s start from the beggining ILC: International Linear Collider
500 MeV CMS
Electron-positron collider
Nominal Luminosity
Marc Montull DESY summer students September

12. Marc Montull DESY summer students 2008 12 September 2008 12

13. We would like to find Supersymmetric particles…
Marc Montull DESY summer students September

14. related to detection of the two lightest SUSY particles
My project:
related to detection of the two lightest SUSY particles
Marc Montull DESY summer students September

15. Is it possible to produce and detect them?
My project:
related to detection of the two lightest SUSY particles
Is it possible to produce and detect them?
Marc Montull DESY summer students September

16. SUSY Weak scale SUSY models Are highly motivated extensions of the SM
Marc Montull DESY summer students September

17. SUSY Weak scale SUSY models Are highly motivated extensions of the SM
mSUGRA (minimal Supergravity)
Convenient to study the gravity mediated SUSY breaking models
Marc Montull DESY summer students September

18. SUSY 4 parameters and 1 sign Weak scale SUSY models
Are highly motivated extensions of the SM
mSUGRA (minimal Supergravity)
Convenient to study the gravity mediated SUSY breaking models
4 parameters and 1 sign
m0, M1/2, A0, tan β, sign of μ
Marc Montull DESY summer students September

19. Mass spectrum only depends on
SUSY
It can be seen that
Mass spectrum only depends on
2 parameters !!
mSUGRA
m0, M1/2
Marc Montull DESY summer students September

20. Mass spectrum only depends on
SUSY
Is there any way of constraining these parameters?
It can be seen that
Mass spectrum only depends on
2 parameters !!
mSUGRA
m0, M1/2
Marc Montull DESY summer students September

21. Dark matter WMAP (Wilkinson Microwave Anisotropy Probe)
Measured DM content of the Universe
Marc Montull DESY summer students September

22. Dark matter ? WMAP (Wilkinson Microwave Anisotropy Probe)
Measured DM content of the Universe
It sets constraints to SUSY mass spectrum
Marc Montull DESY summer students September

23. Dark matter ? WMAP (Wilkinson Microwave Anisotropy Probe)
Measured DM content of the Universe
It sets constraints to SUSY mass spectrum
mSUGRA
Marc Montull DESY summer students September

24. Dark matter mSUGRA Gravity-mediated supersymmetry breaking
LSP is neutralino
Marc Montull DESY summer students September

25. Dark matter mSUGRA Gravity-mediated supersymmetry breaking
R-parity conserved
mSUGRA
LSP is neutralino
Neutralino is stable
Marc Montull DESY summer students September

26. Dark matter mSUGRA Gravity-mediated supersymmetry breaking
R-parity conserved
Neutralino couples to other particles very weakly
mSUGRA
LSP is neutralino
Neutralino is stable
Hard to detect
Marc Montull DESY summer students September

27. Dark matter mSUGRA NEUTRALINO IS A GOOD CANDIDATE FOR DM
Gravity-mediated
supersymmetry breaking
R-parity conserved
Neutralinos couple to other particles very weakly
mSUGRA
LSP is neutralino
Neutralino is stable
Hard to detect
NEUTRALINO IS A GOOD CANDIDATE FOR DM
Marc Montull DESY summer students September

28. Neutralino good DM candidate
Dark matter
WMAP (Wilkinson Microwave Anisotropy Probe) ?
Measured DM content of the Universe
It sets constraints to SUSY mass spectrum
Neutralino good DM candidate
mSUGRA
Marc Montull DESY summer students September

29. Neutralino good DM candidate
Dark matter
WMAP (Wilkinson Microwave Anisotropy Probe)
Measured DM content of the Universe
It sets constraints to SUSY mass spectrum
Neutralino good DM candidate
mSUGRA
Marc Montull DESY summer students September

30. mSUGRA
Marc Montull DESY summer students September

31. mSUGRA +
WMAP results =
Marc Montull DESY summer students September

32. Possible solutions for m0 and M1/2
mSUGRA +
WMAP results =
Marc Montull DESY summer students September

33. Possible solutions for m0 and M1/2 mSUGRA + WMAP results =
Processes to control DM amount
[1]
Marc Montull DESY summer students September

34. Possible solutions for m0 and M1/2 mSUGRA + WMAP results =
Processes to control DM amount
Marc Montull DESY summer students September

35. Possible solutions for m0 and M1/2
mSUGRA +
WMAP results =
[2]
Marc Montull DESY summer students September

36. Possible solutions for m0 and M1/2
mSUGRA +
WMAP results =
Marc Montull DESY summer students September

37. Motivation SUSY could be produced if latest assumptions where right
Marc Montull DESY summer students September

38. Motivation SUSY could be produced if latest assumptions where right
Co-annihilation region
Mass ≈ Mass
Mass diference Amount of DM
Marc Montull DESY summer students September

39. How to detect them? Motivation
SUSY could be produced if latest assumptions where right
Co-annihilation region
Mass ≈ Mass
Mass diference Amount of DM
How to detect them?
Marc Montull DESY summer students September

40. Motivation Q
Marc Montull DESY summer students September

41. Motivation Q
[3]
Marc Montull DESY summer students September

42. Motivation Q
Marc Montull DESY summer students September

43. Cuts on if electron transverse momentum is low
Electron veto when electron’s transverse momentum is high
[4]
Marc Montull DESY summer students September

44. Need to detect all electrons
Cuts on if electron transverse momentum is low
Electron veto when electron’s transverse momentum is high
Need to detect all electrons
Marc Montull DESY summer students September

45. t-channel
Marc Montull DESY summer students September

46. Little transverse momentum
t-channel Forward process
Little transverse momentum
Marc Montull DESY summer students September

47. Forward region of calorimeter
BeamCal: 4 < θ < 28 mrad
Marc Montull DESY summer students September

48. Problems
Marc Montull DESY summer students September

49. Many radiation in BeamCal
Problems
Many radiation in BeamCal
Beamsstrahlung
Bremsstrahlung
Marc Montull DESY summer students September

50. Many radiation in BeamCal
Problems
Many radiation in BeamCal
Remember that we need to detect all electrons (as many as possible)
Marc Montull DESY summer students September

51. Goal TO WRITE MARLIN processor
Marc Montull DESY summer students September

52. Goal TO WRITE TO DETERMINE MARLIN processor γγ background
Marc Montull DESY summer students September

53. Goal TO WRITE TO DETERMINE FOR MARLIN processor γγ background
SUSY analysis
Marc Montull DESY summer students September

54. What’s the γγ background. Why need to detect energetic electrons
What’s the γγ background? Why need to detect energetic electrons? For vetoing these background Why in the Beam Calorimeter? Because it’s mostly a forward event
Marc Montull DESY summer students September

55. Writing a MARLIN processor
Marc Montull DESY summer students September

56. Marlin Modular Analysis Reconstruction for LINear collider
Modular application framework for LCIO code
Marc Montull DESY summer students September

57. particles information
Marlin Collections
Collections are classes
Way of storing
particles information
Marc Montull DESY summer students September

58. Marlin Processors Gets a particle collection
Marc Montull DESY summer students September

59. Marlin Processors Gets a particle collection Does something to it
Marc Montull DESY summer students September

60. Marlin Processors Gets a particle collection
Does something to it Gives it back
Marc Montull DESY summer students September

61. Marlin Processors Gets a particle collection
Does something to it Gives it back
Standard Methods
virtual void init()
virtual void process RunHeader (LCRunHeader* hdr)
virtual void processEvent (LCEvent *evt)
virtual void check (LCEvent *evt)
virtual void end ()
Marc Montull DESY summer students September

62. My processor
Marc Montull DESY summer students September

63. Read Variables from steering file
Main steps
Read Variables from steering file
Read INPUT collection
Marc Montull DESY summer students September

64. Main steps Read Variables from steering file Read INPUT collection
Select electrons or photons
Select those within chosen energy range
Propagate from IP to Bcal given B field , particle charge
Marc Montull DESY summer students September

65. Main steps Read Variables from steering file Rotation of axis
Get average energy density on each detector layer from ROOT file
Using BcEnergyDensity
Read INPUT collection
Select electrons or photons
Select those within chosen energy range
Propagate from IP to Bcal given B field , particle charge
Marc Montull DESY summer students September

66. Main steps Beam Calorimeter Read Variables from steering file
Rotation of axis
Get average energy density on each detector layer from ROOT file
Using BcEnergyDensity
Read INPUT collection
Select electrons or photons
Beam Calorimeter
Sum Energy density for all layers
Select those within chosen energy range
Propagate from IP to Bcal given B field , particle charge
Marc Montull DESY summer students September

67. Main steps Read Variables from steering file Rotation of axis
Get average energy density on each detector layer from ROOT file
Using BcEnergyDensity
Read INPUT collection
Select electrons or photons
Sum Energy density for all layers
Select those within chosen energy range
Parametrize efficiency of detector given Particle’s energy, energy density
Propagate from IP to Bcal given B field , particle charge
MoteCarlo method to see if detected TRandom3, get random seed
Marc Montull DESY summer students September

68. Main steps Read Variables from steering file Rotation of axis
If detected write it to OUPUT collection
Get average energy density on each detector layer from ROOT file
Using BcEnergyDensity
Read INPUT collection
END
Select electrons or photons
Sum Energy density for all layers
Select those within chosen energy range
Parametrize efficiency of detector given Particle’s energy, energy density
Propagate from IP to Bcal given B field , particle charge
MoteCarlo method to see if detected TRandom3, get random seed
Marc Montull DESY summer students September

69. Main steps Additional features Read Variables from steering file
Rotation of axis
If detected write it to OUPUT collection
Get average energy density on each detector layer from ROOT file
Using BcEnergyDensity
Read INPUT collection
END
Select electrons or photons
Sum Energy density for all layers
Select those within chosen energy range
Additional features
Parametrize efficiency of detector given Particle’s energy, energy density
Create if wanted a ROOT tree for each kind of particle
Propagate from IP to Bcal given B field , particle charge
MoteCarlo method to see if detected TRandom3, get random seed
Marc Montull DESY summer students September

70. Steering file gives parameters to the processor
Marc Montull DESY summer students September

71. Steering file gives parameters to the processor
B field
Particle type
Beam energy
BCal position
Energy range
thresholdMax
thresholdMin
Input collection name
Output collection
detectAll
createRootTree
It looks like this
Steering file
Marc Montull DESY summer students September

72. Steering file gives parameters to the processor
B field
Particle type
Beam energy
BCal position
Energy range
thresholdMax
thresholdMin
Input collection name
Output collection name
detectAll (within E range)
createRootTree
Output collection of detected electrons in the BCal
Input collection
Processor
(forwardveto)
Steering file
Output collection
Marc Montull DESY summer students September

73. Conclusions That’s all I did The processor seems to work fine
It will be available to anyone after some further checks are done
Already someone expecting to use it !!! 
Marc Montull DESY summer students September

74. Checks
Written a new collection to see that the ouput collection from my veto processor readable and usable
Checked that efficiencies are as expected for different energy ranges
Checking that everything is ok
Marc Montull DESY summer students September

75. I’d like to thank My supervisors: Jenny List Mikael Berggren
Summer student coordinators
Andrea Schrader
Joachim Mayer
My group collegues
Moritz Beckmann
Christian Helebrant
Daniela Kafer
Tony Hartin
Nicola D’Ascenzo
Niels Meyer
Benjamin Lutz
Sebastian Ricther
Jan Engels
All the summer students !!!
Marc Montull DESY summer students September

76. And thanks for your attention !!!
Have a nice day !
And thanks for your attention !!!
Marc Montull DESY summer students September

77. Questions?

78. References
[1,2]
Experimental Implications for a Linera Collider of the SUSY Dark Matter Scenario, hep-ph/ v1
BeamCal performance at different ILC Beam Parameter Sets, Vladimir Drugakov
New Analysis of SUSY Dark Matter Scenarios ILC, Zhiqing Zhang, ph-hep/ v1
[3]
[4]
Marc Montull DESY summer students September