Magnetic Monopole Search at a high altitude

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Magnetic Monopole Search at a high altitude with
the SLIM (Search for Light Magnetic Monopoles)
experiment
http//www.bo.infn.it/slim/
Eduardo Medinaceli for the SLIM collaboration
S. Balestra, S. Cecchini, M. Cozzi, M. Errico, F.
Fabri, G. Giacomelli, R. Giacomelli, M.
Giorgini, A. Kumar, S. Manzoor, J. McDonald, G.
Mandrioli, S. Marcellini, A. Margiotta, E.
Medinaceli, L. Patrizii, J. Pinfold , V. Popa,
I.E. Qureshi, O. Saavedra, Z. Sahnoun, G. Sirri,
M. Spurio, V. Togo, A. Velarde , A. Zanini
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Magnetic Monopoles
Glashow et. al
GUT MM 1016 - 1017 GeV
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De Rujula CERN-TH 7273/94, E. Huguet P. Peter
hep-ph/ 901370, T.Kephart, Q. Shafi Phys. Lett.
B520(2001)313, Wick et al. Astropart. Phys. 18,
663 (2003)
Intermediate Mass Magnetic Monopoles (IMM)
Produced in the Early Universe in later phase
transitions
(105 M 1012 GeV)
IMMs can be accelerated in the
galactic B field to relativistic velocities
W gD B L 6x1019 eV
(B/3 µG)(L/300pc) Galaxy W ?
6x1019 eV Neutron stars W ? 1020 - 1024 eV
AGN W ? 1023 - 1024 eV
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Energy losses of IMM
ß gt 10-2 Ionization (à la Bethe-Bloch)
(Zeeq)2 (gß)2
(a)
10-4ltßlt10-2 Excitation (Medium as Fermi gas)

10-4ltßlt10-3 Drell effect M He ? M He
Penning effect He CH4 ? He CH4 e-
(b)
ß lt 10-4 Elastic collisions
(c)
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SLIM Nuclear Track Detectors (NTD)
Chemical etching solutions
The alcohol added in the etching
solution improved the detector surface quality
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Calibrations
In49 Pb82 158 A GeV CERNSPS, Pb
target Fe26 Si14 1 and 5 A GeV BNLAGS, CH2
target 0.41 A GeV Fe26 and 0.29 A GeV C6 HIMAC
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SLIM layout
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SLIM stacks and search techniche
A 24 x 24 cm2 t 1.23466 g/cm2 h 8.37
mm3
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Accessible regions in the parameter space (mass,
??) for IMMs coming from above

• 105 MIMM 1012 GeV
• b gt 0.03

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Energy losses in CR39 and Acceptance
IMM
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SLIM scan
L1 scan 3 X Mag, stereo microscope scanned
twice 99 20 40 X Mag
Coincidence area 0.5 cm2
Measured with 6.3ob X 25oc Mag Event p and ?
are equal within 20
L5 scan 500 1000 X Mag
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Classifications of Tracks for Scanning in the
SLIM NTDs
(a) (b) (c)
(d) (e) (f)
(g) (h)
collinear etch-pits
Different Track Shapes as Observerd in the SLIM
NTDs

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Statistical studies of n indiced background in
CR39
negative positive neutral
C12H18O7 (? 1.31 g/cm3)
Zanini et al._at_Chacaltaya
dim 1450 µm x 1 x 1 cm2
FN 1.8x10-12 cm-2 s-1 100 keV 20 MeV
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SLIM final results
area 427 m2, t 4.22 years, over 2p. No
candidate found! F 1.3x10-15
cm-2sr-1s-1, ßgt0.03 for IMM
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BACKUP SLIDES
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Validazione Monte Carlo
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GUT Monopoles (Gauge, Cosmic,..)
Gauge theories of unified interactions predict
MMs

• Mass mM mX/G gt 1016 GeV 0.02 mg ? 1017 GeV
  
• ( Kaluza Klein poles ? gt 1019 GeV
  , SUSY ? gt 1017 GeV )

• Size extended object

Bg/r2 Magnetic field of a point Dirac monopole
Confinement region virtual gs, gluons,
condensate of fermions -antifermion, 4 fermion
virtual states
Electroweak unification W, Z
Grand Unification virtual X,Y
r ? few fm B g/r2
Radius (cm)
10-29 10-16 10-13

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A Strange Event Observed in the SLIM _7408 Module
0.0
(a)
(b)
5.0
10.0
15.0
20.0
25.0 cm
G 6.3x
2 cm
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