How to distinguish Dirac from t'Hooft-Polyakov monopoles at ATLAS detector?

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• How to distinguish Dirac from t'Hooft-Polyakov
  monopoles at ATLAS detector?

Yu. Kurochkin, I. Satsunkevich, Dz. Shoukavy, S.
Harkusha B.I. Stepanov Institute of Physics,
Minsk
Yu. Kulchitsky, N. Rusakovich JINR, Dubna
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Introduction
WHY does quantisation of the electric charge
exist?
In 1931 Dirac showed that the existence of
single magnetic monopole with magnetic charge g
explained the quantization of electric charge e
in terms of the Dirac quantization condition

• e g n hc/2, n0,1,2, (P.A.M. Dirac,
  1931)

Besides explaining the quantization of electric
charge, the existence of magnetic charges
restores the symmetry of the Maxwells
equations
Thus, existence of both electric and magnetic
charge in the universe requires charge
quantization. Since the quantization of electric
charge in nature is well established but still
mysterious, the discovery of just a single
monopole would provide a much wanted explanation.
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Introduction
New situation was created in 1974 after
work's Polyakov and 'tHooft in which they
demonstrated monopole solutions in the SO(3)
Georgi-Glashow model. Later it was discovered
that any scheme of Grand Unification with an
electromagnetic U(1) subgroup embedded into a
semi-simple gauge group, which became
spontaneously broken by Higgs mechanism,
possessed monopole solutions inevitably.
The monopoles of the usual Grand Unification have
a mass of the order of the unification scale
1017 GeV and therefore cannot be discovered at
the current or future accelerators. They could
only be produced in the first instants of our
Universe and can be searched for in the
penetrating cosmic radiation. However, there
are models of the Grand Unification where
unification scale could be significantly lowered
through appearance of extra dimensions. Thus,
these monopoles have masses which can be produced
at LHC energies.
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The most recent limits on the monopole mass

• Tevatron
• p p collisions
• Experiment E-882
• (Al) n1, M gt 285 GeV
• (Al) n2, M gt 355 GeV
• (Be) n3, M gt 325 GeV
• (Be) n6, M gt 420 GeV

LEP 2 e e- - collisions

• HERA
• e p collisions
• n1,2,3,6

45 GeV lt M lt 102 GeV
(Al) M gt 140 GeV
Drell- Yan production
CDF Run II M gt 360 GeV
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Monopole production
By a Dirac monopole we mean a particle without
electric charge or hadronic interactions and with
magnetic charge g satisfying the Dirac
quantization condition.
Going from lepton to monopole production we
replace
e gß
Two photon s1/2
Drell-Yan
Differential cross section
Differential cross section
When we make duality substitution e gß the
Drell-Yan model satisfy the unitarity relation
up to n3 Therefore, we need to use n3 cross
section as the unitarity limit for all ngt3
As it follows from differential cross section we
have all partial waves for two photon production.
Thus, we have no any contradiction with unitarity
for ?? processes.
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How can we search monopole at LHC?
If magnetic monopole produced in ATLAS then
monopole would be revealed by its unique
characteristic.

1. Transition Radiation
2. The large value of a magnetic charge means that
   ionization energy losses will be several orders
   of magnitude greater for monopoles than for
   electrically charged particle.
3. Trapped magnetic monopoles can be draft by the
   magnetic field and further registered.
4. Dirac and GUT monopoles have different appearance
   in detector.

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GUT Monopoles

• ??? ???????? ?? ????? ?????? ???????? ???????????
  ???????? ?? ???????? ??????- ???????? ?????
  ????? (??????? ????????????).
• ???? ???????? ?????? ???????? ?????? ???????
  ? ???????? ??? ??????????? ????? ????. ?????? ???
  ??????? ???? ??? ???? ????????, ?????????? ??
  ???????
• (1)
  (2)
• ?????? ???? ??????? ??????? ????? ????????
  90, ?????? 10. ?????? ??????? ??? ????
  ???????? ????????? ???????
• ?? ??????? ????? ???????? ????????, ?? ???
  ?????????????, ????????? ?? .

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GUT Monopoles

• ??? ??????????? ???????? ? ??? ?????????????
  ????? ???????? ?????? ?? ???????? ?? ??????????
  ????????? ??? ???????????, ? ????? ? ????
  ??????????? ???????? ???? ?????? ????? ?
  ?? ? ? ? ?.?.
• - ????? ????? ??????? 0,5 ??? ?
  ???????????? ???????, ?? 0.25 ??? ???
  ??, ? ????? ??????????.
• - ????? ????? ??????????.

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???????????????? ????????
10
???????????????? ????????
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Monte Carlo Simulation-Recent work

• The behavior of the magnetic monopole inside the
  Atlas detector will be similar with the one of a
  massive, neutral particle that interacts with
  matter via ionization using a modified
  Bethe-Block formula.
• The magnetic monopole was implemented in this
  manner in Geant4 by Mr. Vladimir Ivantchenko and
  Andrea dell Acqua
• Now there is a work on addition G4 example for a
  magnetic monopole to current release Athena 14.5.0

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Future plans

• The creation of Monte-Carlo generator for
  two-photon and diffraction monopole productions.
• The estimation of the detector and trigger
  efficiencies.
• Simulation of monopole catalysis in detector.