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A Direct Search for Magnetic Monopoles at H1

HEP03, Aachen, 17 -23/7/03. A Direct Search for Magnetic Monopoles at H1. David Milstead The University of Liverpool. Monopoles in Particle Physics. Electric charge quantisation. Dirac - e=nh/g m 0. Gauge group symmetry breaking.

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A Direct Search for Magnetic Monopoles at H1

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  1. HEP03, Aachen, 17-23/7/03 A Direct Search for Magnetic Monopoles at H1 David Milstead The University of Liverpool

  2. Monopoles in Particle Physics Electric charge quantisation Dirac - e=nh/gm0 Gauge group symmetry breaking ‘t hooft/Polyakov – Monopole from breaking of simple symmetry group into U(1) SUSY GUTs: 1015 GeV Little Higgs: 1-5 TeV ?

  3. s e’ e aem m ag ag m Monopoles at HERA First search in ep at =300 GeV Sensitive to 150 GeV mass QED coupling for Dirac Monopole gD ag=gD2/4p =34 aem=1/137 p Processes predicted but not rate 103 greater ionisation energy loss rate than mip

  4. Monopoles in the H1 beam pipe Monopoles of strength > 0.75 gD stopped Bind to Al nucleus dipole moment and only released by melting (Milton et al.) Take 60cm section of 2mm thick H1 beam-pipe around interaction zone. Used 1994-1997 : lumi=60pb-1 Cut into 14 stripsand pass through superconducting loops and measure current.

  5. Southampton SQUID • DC SQUID (2G mod. 581) at Southampton Oceanography Centre, UK. • Sample sizes up to 1m long and 5cm radius. • Measures changes in magnetic field 10-12 T.

  6. B i sc loop solenoid Calibration Signature of monopole is persistent current Use solenoids with varying currents to mimick step x 10-2 90gD Induced current x 10-1 10gD 1.2gD position /cm

  7. Signal survival Monopole signal survives after strip traversal strip i Solenoid ( = 1 gd)

  8. Beam pipe measurements Induced current from strips Dirac Monopole Current Strip number No candidates found

  9. Monopole Acceptance Use gg-> mm (comphep) model Rising acceptance with high charge and low mass

  10. Cross-section upper limits First upper limits in ep collisions

  11. Upper limit for Dirac Monopole Production Different experimental techniques Competitive ep limit

  12. Upper limit for 3gd monopoles Only limits from ep and pp

  13. s Summary and Outlook Magnetic monopoles play fundamental role in modern physics theories. First search in electron-proton scattering at =300 GeV at the H1 experiment Search for monopoles stopped in the beam pipe. Monopole masses up to 150 GeV and charges 1 < gD < 6 excluded.

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