Search for nuclearites with the SLIM detector

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Search for nuclearites with the SLIM detector
From Colliders to Cosmic Rays 7 13 September
2005, Prague, Czech Republic

• V. Popa, for the SLIM Collaboration

Search for Light Monopoles
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• Intermediate mass Magnetic Monopoles
• Strange Quark Matter
• Q-balls

The Collaboration (Bolivia, Canada, Italy,
Pakistan) S.Balestra , S. Cecchini, F. Fabbri ,
G. Giacomelli, A. Kumar  S. Manzoor , J. McDonald
, E. Medinaceli , J. Nogales , L. Patrizii, J.
Pinfold , V. Popa , O. Saavedra, G. Sher , M.
Shahzad , M. Spurio, V. Togo, A. Velarde , A.
Zanini
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Chacaltaya Cosmic Ray Laboratory
5230 m a.s.l
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The experiment
Total area 440 m2
One module (24?24 cm2)
In four years of exposure, for a downgoing flux
of particles, the SLIM sensitivity will be about
10-15cm-2s-1sr-1
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Nuclear Track Detectors
CR39 and Makrofol
The track-etch technique
SQM nuggets
200 A GeV S16 or ß 10-2 MM
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Calibrations of NTDs
In49 158 AGeV
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Calibrations of NTDs
Reduced etch rate vs REL
Makrofol
CR39
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The search technique
Up to now, no double coincidences found
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Strange Quark Matter E. Witten, Phys. Rev. D30
(1984) 272A. De Rujula, S. L. Glashow, Nature 312
(1984) 734

• Aggregates of u, d, s quarks electrons , ne
  2/3 nu 1/3 nd 1/3 ns
• Ground state of QCD stable for ?300 lt A lt 1057

rN ? 3.5 x 1014 g cm-3 rnuclei ? 1014 g cm-3
A qualitative picture
black points are electrons
R (fm) 102 103 104
105 106 M (GeV) 106
109 1012 1015 1018
Produced in Early Universe or in strange star
collisions (J. Madsen, PRD71 (2005)
014026) Candidates for cold Dark Matter! Searched
for in CR reaching the Earth

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Low mass nuclearites (strangelets) in
M (GeV)
At least two propagation models allow them to
reach the SLIM atmospheric depth.
Spectator participant (mass decrease) (Wilk
Wlodarczyk, Heavy Ion Phys. 4(1986)396
Accretion (mass increase) S. Banerjee al., PRL
85 (2000) 1384
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Important feature Z /A 1
M. Kasuya et al. Phys.Rev.D47(1993)2153
H.Heiselberg, Phys. Rev.D48(1993)1418 J. Madsen
Phys. Rev.Lett.87(2001)172003
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Strangelets small lumps of SQM
- 300 lt A lt 106 Produced in collisions of
strange stars R. Klingenberg J. Phys. G27
(2001) 475 -charged Accelerated as ordinary
nuclei
Mass increase during propagation gt large fluxes
expected at the SLIM altitude
Mass decrease during propagation gt smaller
fluxes expected!
How low?
G. Wilk et al. hep-ph/ 0009164 (2000) J. Madsen
et al. Phys.Rev.D71 (2005) 014026
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Assuming the fragmentation propagation
In the accretion scenario, fluxes could be
(much) larger (?)
Which is really the lowest A for which
strangelets are stable?
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High mass nuclearites
M (GeV)
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Intermediate mass nuclearites
M (GeV)
M. Ambrosio et al., Eur.Phys. J. C13 (2000) 453
L. Patrizii, TAUP 2003
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Nuclearites - basics
A. De Rújula and S.L. Glashow, Nature 312 (1984)
734

• Typical galactic velocities ? ? 10-3
• Dominant interaction elastic collisions with
  atoms in the medium
• Dominant energy losses
• Phenomenological flux limit from the local
  density of DM

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Arrival conditions to SLIM
The velocity of a nuclearite entering in a medium
with v0, after a path L becomes
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Detection conditions in SLIM
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preliminary results
About 170 m2 of detectors with an average
exposure time of 3.5 years were analyzed.
Various background tracks (compatible with
nuclear recoil fragments produced by C.R.
neutrons) were found.
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perspectives
Detector removal from Chacaltaya during
fall Analysis completed by mid 2006
Discovery of IMMs, SQM or Q-balls???
Otherwise, significant limits in not yet explored
mass regions!
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Nuclearites
High altitude SLIM 5300 m White Mountain
4800 m Mt. Norikura 2000 m Underground Ohya
100 hg/cm2 MACRO 3700 hg/cm2
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Light and intermediate mass MMs
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Charged Q- balls
AKENO, KEK ground level MACRO 3700 hg/cm2
undg. AMS Space Station SLIM 540 g/cm2 atm depth
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perspectives
Detector removal from Chacaltaya during
fall Analysis completed by mid 2006
Discovery of IMMs, SQM or Q-balls???
Otherwise, significant limits in not yet explored
mass regions!
Strong constrains, rejection/confirmation on
models of strangelets production and propagation.