magnetic monopole search at a high altitude with the slim (search for light magnetic monopoles)...
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Magnetic Monopole Search at a high altitudewith 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
1931 Dirac: Quantization of electric charge Proc. R. Soc. London, 133 ( 1931) 60
Magnetic Monopoles
...3,2,1,n,2
c n eg
Dirac relation
DD gng , e2
137
2e
cg
SU(5) SU(3)C x [SU(2)L x U(1)Y]EW SU(3)C x U(1)EM
102 GeV
10-10 s10-35 s
1015 GeV
GUT MM1016 - 1017 GeV
Glashow et. al
Intermediate Mass Magnetic Monopoles (IMM)
SO(10)
1015 GeV
10-35 s
SU(4) x SU(2)L x SU(2)R
109 GeV
10-23 s
SU(3)C x [SU(2)L x U(1)Y]EW +…
Virtual vector bosons X, Y?
Electroweak Unification W, Z
Virtual photons and gluons Confinement region
Magnetic field of a point MM
10-25 10-16 10-13 Radius (m)
Produced in the Early Universe in later phase transitions
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)
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
(105 ≤ M ≤ 1012 GeV)
liquid H2
(c)(b)
(a) 10-4<β<10-2 Excitation (Medium as Fermi gas) 10-4<β<10-3 Drell effect M + He M + He*
Penning effect He*+ CH4 He + CH4 + e-
β < 10-4 Elastic collisions (c)
β > 10-2 Ionization (à la Bethe-Bloch) (Zeeq)2= (gβ)2 (a)
Energy losses of IMM
(b)
CR39®ρ = 1.32 g /cm3
(C12H18O7)n
A/Z = 1.877
MAKROFOL ®ρ = 1.29 g /cm3
(C16H14O3)n
A/Z = 1.896
158 A GeV 82+Pb in CR3920X Mag.
150X150 μm2
Chemical etching solutions
CR39® 0.1% dioctyl phthalate DOPρ = 1.32 g /cm3
(C12H18O7)n
150X150 μm2
SLIM Nuclear Track Detectors (NTD)
detector type solution
CR39 8N KOH + 1.5% alcohol 70° C 30h
strong CR39 DOP 8N KOH + 1.5% alcohol 75° C 30h
Makrofol 6N KOH + 20% alcohol 75° C 30h
soft CR39 6N NaOH + 1% alcohol 70° C 40h
CR39 DOP 6N NaOH 70° C 40h
The alcohol added in the etching solutionimproved the detector surface quality
Calibrations
In49+ & Pb82+ 158 A GeV CERN–SPS, Pb target
Fe26+ & Si14+ 1 and 5 A GeV BNL–AGS, CH2 target
0.41 A GeV Fe26+ and 0.29 A GeV C6+ HIMAC
detector
type Z/βREL
[MeVcm2/g]vB
[ μm/h]
CR39 14 200 7.2±0.4
strong CR39DOP 19 240 5.9±0.3
Makrofol 50 2500 3.4±0.1
soft CR39 7 501.25±0.02
CR39DOP 10 2350.98± 0.02
p-1
Survived beam
Fragments
Target
Incident ion beam
NTDNTD
Z/ = 78
Z/ = 82
Z/ = 51 60 70
78
Z/ = 10
2030 40
Z/ = 46
Z/ = 49CR39 Makrofol
SLIM layout
Area = 427 m2 (7420 stacks)Atm depth = 540 g/cm2(5230 m a.s.l.) R ~ 12.5 GVExposure t = 4.22 years
Atm Preassure ~ 0.5 atmMean Temp = 12 °CRd concentr. ~ 40-50 Bq/m3
Neutron flux = 1.8x10-2 cm-2s-1
SLIM stacks and search techniche
A = 24 x 24 cm2
t = 1.23466 g/cm2
h = 8.37 mm3
1000 μm
1450 μm
570 μm
125 μm
Thickness
STRONG
SOFT
SOFT
Slow IMM
FastIMM
Nuclear fragment
105 ≤ MIMM ≤ 1012 GeV > 0.03
Accessible regions in the parameter space (mass, )for IMMs coming from above
IMM
Energy losses in CR39 and Acceptance
CR39 (strong)
L5 scan: 500 – 1000 X Mag
L1 scan 3 X Mag, stereo microscope; scanned twice ~ 99%20 – 40 X Mag
SLIM scan
Coincidence area ~ 0.5 cm2
Measured with 6.3ob X 25oc MagEvent ≡ p and θ are equal within 20 %
Classifications of Tracks for Scanning in the SLIM NTDs
Different Track Shapes as Observerd in the SLIM NTDs
(a) (b) (c) (d) (e) (f) (g) (h)
collinear etch-pits
negativepositiveneutral
C12H18O7
(ρ = 1.31 g/cm3)dim = 1450 μm x 1 x 1 cm2
ΦN ~ 1.8x10-12 cm-2 s-1 100 keV – 20 MeV
Zanini et al.@Chacaltaya
Statistical studies of n indiced background in CR39
area = 427 m2, t = 4.22 years, over 2π. No candidate found!
Φ ≤ 1.3x10-15 cm-2sr-1s-1, β>0.03 for IMM
SLIM final results
BACKUP SLIDES
Validazione Monte Carlo
Gauge theories of unified interactions predict MMs
Mass mM ≥ mX/G > 1016 GeV ~ 0.02 mg 1017 GeV
( Kaluza –Klein poles > 1019 GeV , SUSY > 1017 GeV )
GUT Monopoles (Gauge, Cosmic,..)
SU(5)1015 GeV
10-35 sSU(3)C x [SU(2)L x U(1)y]
102 GeV
10-9 sSU(3)C x U(1)EM
Grand Unification: virtual X,Y
Electroweak unification: W, Z
Confinement region: virtual s, gluons, condensate of fermions -antifermion, 4 fermion virtual states
B=g/r2 Magnetic field of a point Dirac monopole
Radius (cm)10-29 10-16 10-13
r few fm B ~ g/r2
Size: extended object
(b)0.0
10.0
15.0
20.0
25.0cm
5.0
(a)
~2 cm
G = 6.3x
(d) G = 6.3x
(c)
G = 6.3x
A Strange Event Observed in the SLIM _7408 Module
74107408
Layout of the SLIM modules near 7408 module
Positions of the SLIM modules inside the wooden box during the flight Bologna-La Paz and La Paz-Bologna..