Abstract.
Searches for H Z production with the Higgs boson decaying into an invisible final state were performed using the data collected by the DELPHI experiment at centre-of-mass energies between 188 GeV and 209 GeV. Both hadronic and leptonic final states of the Z boson were analysed. In addition to the search for a heavy Higgs boson, a dedicated search for a light Higgs boson down to 40 GeV/c 2 was performed. No signal was found. Assuming the Standard Model HZ production cross-section, the mass limit for invisibly decaying Higgs bosons is 112.1 GeV/c 2 at 95% confidence level. An interpretation in the Minimal Supersymmetric extension of the Standard Model (MSSM) and in a Majoron model is also given.
Similar content being viewed by others
References
A. Djouadi, P. Janot, J. Kalinowski and P.M. Zerwas, Phys. Lett. B 376, 220 (1996)
T. Binoth and J.J. van der Bij, Z. Phys. C 75, 17 (1997)
K. Belotsky, Invisible Higgs boson decay into massive neutrinos of fourth generation, hep-ph/0210153
Y. Chikashige, R.N. Mohapatra, R.D. Peccei, Phys. Lett. B 98, 265 (1981)
F. de Campos, Phys. Rev. D 55, 1316 (1997)
S.P. Martin and J.D. Wells,Phys. Rev. D 60, 035006 (1999)
DELPHI Collaboration, P. Abreu, Eur. Phys. J. C 2, 1 (1998)
DELPHI Collaboration, P. Abreu, Phys. Lett. B 459, 367 (1999)
ALEPH Collaboration, A. Heister Phys. Lett. B 526, 191 (2002)
L3 Collaboration, M. Acciarri, Phys. Lett. B 485, 85 (2000)
DELPHI Collaboration, P. Abreu, Nucl. Instrum. Methods A 378, 57 (1996)
DELPHI Silicon Tracker Group, P. Chochula, Nucl. Instrum. Methods A 412, 304 (1998)
P. Janot, in CERN Report 96-01, Vol. 2, p. 309
S. Jadach, B.F.L. Ward and Z. Was, Comput. Phys. Commun. 130, 260 (2000)
S. Jadach, W. Placzek and B.F.L. Ward, Phys. Lett. B 390, 298 (1997)
E. Accomando and A. Ballestrero, Comput. Phys. Commun. 99, 270 (1997)
T. Sjöstrand, Comput. Phys. Commun. 39, 347 (1986)
F.A. Berends, P.H. Daverveldt, R. Kleiss, Nucl. Phys. 253, 421 (1985)
S. Jadach, B.F.L Ward and Z. Was, Comput. Phys. Commun. 79, 503 (1994)
S. Catani, Phys. Lett. B 269, 432 (1991)
T.G.M. Malmgren, Comput. Phys. Commun. 106, 230 (1997)
DELPHI Collaboration, P. Abreu, Phys. Lett. B 372, 172 (1996)
DELPHI Collaboration, J. Abdallah, Final results on SM and MSSM Neutral Higgs bosons, CERN EP/2003-008, Eur. Phys. J (accepted)
L. Lönnblad, Comput. Phys. Commun. 71, 15 (1992)
M. W. Grünewald et al., In CERN Report 2000-009 p. 1-135. Four-fermion production in electron positron collisions.
T. Sjöstrand, PYTHIA 5.7 / JETSET 7.4, CERN-TH.7112/93 (1993)
DELPHI Collaboration, J. Abdallah, ZZ production in e + e − interactions at \(\sqrt{s}=183\)-209 GeV, CERN EP/2003-009, Eur. Phys. J (accepted)
DELPHI Collaboration, P. Abreu, Phys. Lett. B 511, 159 (2001)
A.L. Read, in CERN Report 2000-005 p. 81 (2000)
DELPHI Collaboration, P. Abreu, Eur. Phys. J. C 10, 563 (1999)
DELPHI Collaboration, P. Abreu, Eur. Phys. J. C 17, 187 (2000)
DELPHI Collaboration, J. Abdallah, Eur. Phys. J. C 23, 409 (2002)
DELPHI Collaboration, J. Abdallah, Searches for Supersymmetric particles in e + e − collisions up to 208 GeV and interpretation of the results within the MSSM, CERN-EP/2003-007, Eur. Phys. J. C (accepted)
DELPHI Collaboration, J. Abdallah, Study of the Anomaly Mediated SUSY Breaking Model in DELPHI, CERN-EP/2003-048, and Eur. Phys. J. C (submitted)
Author information
Consortia
Additional information
Received: 2 September 2003, Revised: 10 November 2003, Published online: 15 January 2004
Rights and permissions
About this article
Cite this article
The DELPHI Collaboration. Searches for invisibly decaying Higgs bosonswith the DELPHI detector at LEP. Eur. Phys. J. C 32, 475–492 (2004). https://doi.org/10.1140/epjc/s2003-01469-8
Issue Date:
DOI: https://doi.org/10.1140/epjc/s2003-01469-8