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Search for charginos, neutralinos and gravitinos at LEP

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Abstract

An update of the searches for charginos and neutralinos in DELPHI is presented, based mainly on recent data collected at centre-of-mass energies of 161 GeV and 172 GeV. No signal is found. For a sneutrino with mass above 300 GeV/c 2 and a mass difference between the chargino and the lightest neutralino above 10 GeV/c 2, the lower limit at 95% confidence level on the chargino mass ranges from 84.3 GeV/c 2 to the kinematical limit (86.0 GeV/c 2), depending on the mixing parameters. The limit decreases for lower chargino-neutralino mass differences. The limit in the case of a light sneutrino is 67.6 GeV/c 2, provided that that there is no light sneutrino with a mass within 10 GeV/c 2 below the chargino mass. Upper limits on neutralino pair production cross-sections of about a picobarn are derived. The (μ,M 2) domain excluded in the MSSM-GUT scenario is determined by combining the neutralino and chargino searches. These results imply a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 24.9 GeV/c 2 for tanß >- 1. The search has also been extended to the case where the lightest neutralino is unstable and decays into a photon and a gravitino. imply a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 24.9 GeV/c 2 for tanß >- 1. The search has also been extended to the case where the lightest neutralino is unstable and decays into a photon and a gravitino.

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References

  1. P. Fayet and S. Ferrara, Phys. Rep.32 (1977) 249;

    Article  ADS  MathSciNet  Google Scholar 

  2. H.P. Nilles, Phys. Rep.110 (1984) 1;

    Article  ADS  Google Scholar 

  3. H.E. Haber and G.L. Kane, Phys. Rep.117 (1985) 75

    Article  ADS  Google Scholar 

  4. DELPHI Coll., P. Abreu et al., Phys. Lett.B382 (1996) 323

    Article  ADS  Google Scholar 

  5. DELPHI Coll., P. Abreu et al., Phys. Lett.B387 (1996) 651

    Article  ADS  Google Scholar 

  6. DELPHI Coll., P. Abreu et al., Phys. Lett.B380 (1996) 471

    ADS  Google Scholar 

  7. P.Rebecchi, Optimisation de l'herméticité du détecteur DELPHI pour la recherche de particules supersymétriques à LEP2, PhD. thesis, LAL 96-30 (May 1996), Université Paris XI Orsay, CERN THESIS-96-003

  8. D. Dicus et al., Phys. Rev.D41 (1990) 2347;

    ADS  Google Scholar 

  9. D. Dicus et al., Phys. Rev.D43 (1991) 2951;

    ADS  Google Scholar 

  10. D. Dicus et al., Phys. Lett.B258 (1991) 231

    Article  ADS  Google Scholar 

  11. S. Dimopoulos et al., Phys. Rev. Lett.76 (1996) 3494

    Article  ADS  Google Scholar 

  12. S. Ambrosanio et al., Phys. Rev. Lett.76 (1996) 3498

    Article  ADS  Google Scholar 

  13. J.L. Lopez and D.V. Nanopoulos, Mod. Phys. Lett.A10 (1996) 2473;

    Article  ADS  Google Scholar 

  14. J.L. Lopez and D.V. Nanopoulos, Phys. Rev.D55 (1997) 4450

    ADS  Google Scholar 

  15. S. Ambrosanio et al., Phys. Rev.D54 (1996) 5395

    ADS  Google Scholar 

  16. A. Bartl, H. Fraas and W. Majerotto, Z. Phys.C30 (1986) 441;

    ADS  Google Scholar 

  17. A.Bartl, H. Fraas and W. Majerotto, Z. Phys.C41 (1988) 475;

    Google Scholar 

  18. A.Bartl, H.Fraas, W. Majerotto and B.Mösslacher, Z. Phys.C55 (1992) 257

    ADS  Google Scholar 

  19. DELPHI Coll., P. Aarnio et al., Nucl. Instr. and Meth.303 (1991) 233;

    Article  Google Scholar 

  20. DELPHI Coll., P. Abreu et al., Nucl. Instr. and Meth.378 (1996) 57

    Article  ADS  Google Scholar 

  21. S. Navas Concha, Búsqueda de charginos con el detector DELPHI de LEP aE cm = 130 - 172 GeV , Ph.D. thesis, CERN-THESIS-97-005 (June 1997)

  22. T.Sjöstrand, Comp. Phys. Comm.39 (1986) 347

    Article  ADS  Google Scholar 

  23. T. Sjöstrand,Pythia 5.6 andJetset 7.3, CERNTH/6488-92

  24. DELPHI Coll., P. Abreu et al., Z. Phys.C73 (1996) 11

    ADS  Google Scholar 

  25. S. Katsanevas and S. Melachroinos in Physics at LEP2, CERN 96-01, Vol. 2, p. 328

  26. S. Ambrosanio and B. Mele, Phys. Rev.D52 (1995) 3900;

    ADS  Google Scholar 

  27. S. Ambrosanio and B. Mele, Phys. Rev.D53 (1996) 2451

    ADS  Google Scholar 

  28. J.E. Campagne and R. Zitoun, Z. Phys.C43 (1989) 469

    ADS  Google Scholar 

  29. S. Jadach and Z. Was, Comp. Phys. Comm.79 (1994) 503

    Article  ADS  Google Scholar 

  30. F.A. Berends, R. Kleiss, W. Hollik, Nucl. Phys.B304 (1988) 712

    Article  ADS  Google Scholar 

  31. F.A. Berends, R. Pittau, R. Kleiss, Comp. Phys. Comm.85 (1995) 437

    Article  ADS  Google Scholar 

  32. S. Nova, A. Olshevski, and T. Todorov, A Monte Carlo event generator for two photon physics, DELPHI note 9035 (1990)

  33. F.A. Berends, P. H. Daverveldt, R. Kleiss, Comp. Phys. Comm.40 (1986) 271

    Article  ADS  Google Scholar 

  34. Comp. Phys. Comm.40 (1986) 285

    Article  ADS  Google Scholar 

  35. Comp. Phys. Comm.40 (1986) 309

    Article  ADS  Google Scholar 

  36. DELPHI Coll., P. Abreu et al., Z. Phys.C74 (1997) 577

    Google Scholar 

  37. O. Helene, Nucl. Instr. and Meth.212 (1983) 319

    Article  Google Scholar 

  38. DELPHI Coll., P. Abreu et al., to appear

  39. V.F. Obraztsov, Nucl. Instr. and Meth.316 (1992) 388

    Article  ADS  Google Scholar 

  40. ALEPH Coll., D. Decamp et al., Phys. Rep.216 (1992) 253;

    Article  Google Scholar 

  41. A. Lopez-Fernandez, DELPHI note 92-95 (Dallas) PHYS 206;

  42. L3 Coll., M. Acciarri et al., Phys. Lett.B350 (1995) 109;

    Article  ADS  Google Scholar 

  43. OPAL Coll., G. Alexander et al., Phys. Lett.B377 (1996) 273

    Article  ADS  Google Scholar 

  44. J. Lopez, D. Nanopoulos and A. Zichichi, Phys. Rev. Lett.77 (1996) 5168

    Article  ADS  Google Scholar 

  45. E. Boos et al. in Physics at LEP2, CERN 96-01, Vol. 2, p.16, hep-ph/9503280

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On leave of absence from IHEP Serpukhov

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DELPHI Collaboration., Abreu, P., Adam, W. et al. Search for charginos, neutralinos and gravitinos at LEP. Eur. Phys. J. C 1, 1–20 (1998). https://doi.org/10.1007/BF01245794

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