Skip to main content

Search for nearly mass-degenerate charginos and neutralinos at LEP

Abstract.

A search was performed for charginos with masses close to the mass of the lightest neutralino in \(\mathrm{e}^{+}\mathrm{e}^{-}\) collisions at centre-of-mass energies of 189-209 GeV recorded by the OPAL detector at LEP. Events were selected if they had an observed high-energy photon from initial state radiation, reducing the dominant background from two-photon scattering to a negligible level. No significant excess over Standard Model expectations has been observed in the analysed data set corresponding to an integrated luminosity of 570 pb-1. Upper limits were derived on the chargino pair-production cross-section, and lower limits on the chargino mass were derived in the context of the Minimal Supersymmetric Extension of the Standard Model for the gravity- and anomaly-mediated Supersymmetry breaking scenarios.

This is a preview of subscription content, access via your institution.

References

  1. 1

    Y.A. Golfand, E.P. Likhtman, JETP Lett. 13, 323 (1971)

    Google Scholar 

  2. 2

    H.P. Nilles, Phys. Rept. 110, 1 (1984)

    Article  Google Scholar 

  3. 3

    S.P. Martin, A Supersymmetry Primer, in G.L. Kane (ed.): Perspectives On Supersymmetry, 1, hep-ph/9709356

  4. 4

    L. Randall, R. Sundrum, Nucl. Phys. B 557, 79 (1999)

    Article  MathSciNet  MATH  Google Scholar 

  5. 5

    G.F. Giudice, M.A. Luty, H. Murayama, R. Rattazzi, JHEP 9812 (1998) 027

  6. 6

    ALEPH Collaboration, R. Barate et al., Eur. Phys. J. C 11, 193 (1999)

    Article  Google Scholar 

  7. 7

    DELPHI Collaboration, P. Abreu et al., Phys. Lett. B 479, 129 (2000)

    Article  Google Scholar 

  8. 8

    L3 Collaboration, M. Acciarri et al., Phys. Lett. B 472, 420 (2000)

    Article  Google Scholar 

  9. 9

    OPAL Collaboration, G. Abbiendi et al., Eur. Phys. J. C 14, 187 (2000)

    Google Scholar 

  10. 10

    C.H. Chen, M.Drees, J.F. Gunion, Phys. Rev. Lett. 76, 2002 (1996)

    Article  Google Scholar 

  11. 11

    K. Riles et al., Phys. Rev. D 42, 1 (1990)

    Article  Google Scholar 

  12. 12

    ALEPH Collaboration, A. Heister et al., Phys. Lett. B 533, 223 (2002)

    Google Scholar 

  13. 13

    DELPHI Collaboration, P. Abreu et al., Phys. Lett. B 485, 95 (2000)

    Article  Google Scholar 

  14. 14

    L3 Collaboration, M. Acciarri et al., Phys. Lett. B 482, 31 (2000)

    Article  Google Scholar 

  15. 15

    OPAL Collaboration, K. Ahmet et al., Nucl. Instrum. Meth. A 305, 275 (1991)

    Google Scholar 

  16. 16

    G. Aguillion et al., Nucl. Instrum. Meth. A 417, 266 (1998)

    Google Scholar 

  17. 17

    S. Katsanevas, P. Morawitz, Comput. Phys. Commun. 112, 227 (1998)

    Article  MATH  Google Scholar 

  18. 18

    W. Beenakker et al., WW Cross-sections and Distributions, In Physics at LEP2, vol. 1, 79, hep-ph/9602351

    Google Scholar 

  19. 19

    S. Thomas, J.D. Wells, Phys. Rev. Lett. 81, 34 (1998)

    Article  MATH  Google Scholar 

  20. 20

    S. Jadach, B.F. Ward, Z. Was, Comput. Phys. Commun. 130, 260 (2000)

    Article  MATH  Google Scholar 

  21. 21

    G. Montagna, M. Moretti, O. Nicrosini, F. Piccinini, Nucl. Phys. B 541, 31 (1999)

    Article  Google Scholar 

  22. 22

    D. Karlen, Nucl. Phys. B 289, 23 (1987)

    Article  Google Scholar 

  23. 23

    S. Jadach, W. Placzek, B.F. Ward, Phys. Lett. B 390, 298 (1997)

    Article  Google Scholar 

  24. 24

    F.A. Berends, R. Kleiss, Nucl. Phys. B 186, 22 (1981)

    Article  Google Scholar 

  25. 25

    M. Skrzypek, S. Jadach, W. Placzek, Z. Was, Comput. Phys. Commun. 94, 216 (1996)

    Article  Google Scholar 

  26. 26

    J. Fujimoto et al., Comput. Phys. Commun. 100, 128 (1997)

    Article  Google Scholar 

  27. 27

    R. Engel, Z. Phys. C 66, 203 (1995)

    Google Scholar 

  28. 28

    G. Marchesini, B.R. Webber, G. Abbiendi, I.G. Knowles, M.H. Seymour, L. Stanco, Comput. Phys. Commun. 67, 465 (1992)

    MATH  Google Scholar 

  29. 29

    J.A.M. Vermaseren, Nucl. Phys. B 229, 347 (1983)

    Article  Google Scholar 

  30. 30

    F.A. Berends, P.H. Daverveldt, R. Kleiss, Nucl. Phys. B 253, 421 (1985)

    Article  Google Scholar 

  31. 31

    T. Sjostrand, Comput. Phys. Commun. 39, 347 (1986)

    Article  Google Scholar 

  32. 32

    OPAL Collaboration, J. Allison et al., Nucl. Instrum. Meth. A 317, 47 (1992)

    Google Scholar 

  33. 33

    J.F. Gunion, S. Mrenna, Phys. Rev. D 64, 075002 (2001)

    Article  Google Scholar 

  34. 34

    OPAL Collaboration, G. Abbiendi et al., Eur. Phys. J. C 16, 185 (2000)

    Google Scholar 

  35. 35

    OPAL Collaboration, K. Ackerstaff et al., Eur. Phys. J. C 2, 213 (1998)

    Article  Google Scholar 

  36. 36

    OPAL Collaboration, K. Ackerstaff et al., Phys. Lett. B 437, 218 (1998)

    Article  Google Scholar 

  37. 37

    G. Abbiendi et al. [OPAL Collaboration], Eur. Phys. J. C 18, 253 (2000)

    Google Scholar 

  38. 38

    T. Junk, Nucl. Instrum. Meth. A 434, 435 (1999)

    Article  Google Scholar 

  39. 39

    C.H. Chen, M. Drees, J.F. Gunion, Phys. Rev. D 55, 330 (1997)

    Article  Google Scholar 

  40. 40

    H. Baer, F.E. Paige, S.D. Protopopescu, X. Tata, ISAJET 7.48: A Monte Carlo Event Generator for p p, anti-p p, and \(e^+e^-\) Reactions, (1999), hep-ph/0001086

Download references

Author information

Consortia

Additional information

Received: 26 July 2002, Published online: 11 July 2003

Rights and permissions

Reprints and Permissions

About this article

Cite this article

The OPAL Collaboration. Search for nearly mass-degenerate charginos and neutralinos at LEP. Eur. Phys. J. C 29, 479–489 (2003). https://doi.org/10.1140/epjc/s2003-01237-x

Download citation

Keywords

  • Supersymmetry Breaking
  • Light Neutralino
  • Initial State Radiation
  • Negligible Level
  • Model Expectation