Search for anomalous Z → γγγ events at LEP

Acciarri, M.; Bobbink, G. J.; Bouwens, B.; Duinker, P.; Erné, F.C.; Koffeman, E.; Linde, F.L.; Massaro, G.; Zhang, D.H.; Zwaan, Bob van der; Buytenhuijs, A.; Filthaut, F.; Hauschildt, D.; Kittel, W.; Koenig, Adriaan; Kuijten, H.; Metzger, W. J.; Raven, G.; Rosmalen, R.; Rossum, W. van; Schotanus, D. J.; Sens, L.C.; Syed, A.A.; Walle, R. T. Van de; Ijzerman, M.P.

doi:10.1016/0370-2693(95)01612-t

Cited by 63 publications

(54 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This production mechanism is intermediate between that of pp experiments such as that given in [21], and that of the possible production through e + e − collisions [182], and conceivably might yield a cleaner interpretation if monopole condensates are responsible for the confinement of quarks [15,207,208,209]. Although the mass limits determined are not as strong as in our experiment described in the previous section, it is crucial that different physical domains be explored carefully.…”

Section: H1 Limitsmentioning

confidence: 58%

“…De Rújula in 1995 [181] proposed looking at the three-photon decay of the Z boson, where the process proceeds through a virtual monopole loop, as shown in figure 13. If we use his formula for the branching ratio for the Z → 3γ process, compared to the current experimental upper limit [182] for the branching ratio of 10 −5 , we can rule out monopole masses lower than about 400 GeV, rather than the 600 GeV quoted by De Rújula. Similarly, Ginzburg and Panfil in 1982 [183] and more recently Ginzburg and Schiller in 1999 [184,185] considered the production of two photons with high transverse momenta by the collision of two photons produced either from e + e − or qq collisions.…”

Section: Indirect Searchesmentioning

confidence: 93%

See 1 more Smart Citation

Theoretical and Experimental Status of Magnetic Monopoles

Milton

Kalbfleisch

Luo

2002

Int. J. Mod. Phys. A

View full text Add to dashboard Cite

Abstract. The Tevatron has inspired new interest in the subject of magnetic monopoles. First there was the 1998 D0 limit on the virtual production of monopoles, based on the theory of Ginzburg and collaborators. In 2000 and 2004 results from an experiment (Fermilab E882) searching for real magnetically charged particles bound to elements from the CDF and D0 detectors were reported. The strongest direct experimental limits, from the CDF collaboration, have been reported in 2005. Less strong, but complementary, limits from the H1 collaboration at HERA were reported in the same year. Interpretation of these experiments also require new developments in theory. Earlier experimental and observational constraints on point-like (Dirac) and non-Abelian monopoles were given from the 1970s through the 1990s, with occasional short-lived positive evidence for such exotic particles reported. The status of the experimental limits on monopole masses will be reported, as well as the limitation of the theory of magnetic charge at present.

show abstract

Section: H1 Limitsmentioning

confidence: 58%

Section: Indirect Searchesmentioning

confidence: 93%

Theoretical and Experimental Status of Magnetic Monopoles

Milton

Kalbfleisch

Luo

2002

Int. J. Mod. Phys. A

View full text Add to dashboard Cite

show abstract

“…Since a simple three photon final state at an e + e − collider should be relatively clean, we do not expect there to be a big difference in the signal acceptance if we were to include a simulated detector response and ISR effects. At the Z-pole, the analysis chosen was by the L3 experiment [56], while the higher energy run with the highest integrated luminosity came from DELPHI [57]. Precise details of each selection can be found in appendix B but they can be generally summarised as requiring a pair of isolated, well identified photons above a certain energy threshold within an angular acceptance accompanied by a third photon with slightly relaxed criteria.…”

Section: Triphoton Signaturesmentioning

confidence: 99%

ALPs at colliders

Mimasu

Sanz

2015

J. High Energ. Phys.

189

205

View full text Add to dashboard Cite

New pseudo-scalars, often called axion-like particles (ALPs), abound in modelbuilding and are often associated with the breaking of a new symmetry. Traditional searches and indirect bounds are limited to light axions, typically in or below the KeV range for ALPs coupled to photons. We present collider bounds on ALPs from mono-γ, tri-γ and mono-jet searches in a model independent fashion, as well as the prospects for the LHC and future machines. We find that they are complementary to existing searches, as they are sensitive to heavier ALPs and have the capability to cover an otherwise inaccessible region of parameter space. We also show that, assuming certain model dependent correlations between the ALP coupling to photons and gluons as well as considering the validity of the effective description of ALP interactions, mono-jet searches are in fact more suitable and effective in indirectly constraining ALP scenarios.

show abstract

“…LEP II and OPAL have 2γ and 3γ data [120], which are employed to put the bounds on the process, e þ e − → γ=Z ⋆ → aγ → 2γ þγ. The L3 Collaboration has searched the process Z → aγ → ðγγÞγ at the Z pole, with a limit on the BR of order 10 −5 [67]. The ATLAS 3γ and Z → 3γ [121,122] search can be translated to the ALP bound as derived in Ref.…”

Section: Axionlike Particlementioning

confidence: 99%

“…Recently, this topic has been addressed for some specific models [56][57][58][59][60]. Large Electron-Positron collider (LEP) has also searched for exotic Z decays into light Higgs [61,62], two light Higgs in the minimal supersymmetric Standard Model [63], photon and missing energy [64][65][66], and three photons [67]. There are also direct searches for DM particles at LEP-II via mono photon final states [68].…”

Section: Introductionmentioning

confidence: 99%

Exposing the dark sector with future Z factories

Liu

Wang

et al. 2018

Phys. Rev. D

View full text Add to dashboard Cite

We investigate the prospects of searching dark sector models via exotic Z-boson decay at future e þ e − colliders with Giga Z and Tera Z options. Four general categories of dark sector models, Higgs portal dark matter, vector-portal dark matter, inelastic dark matter, and axionlike particles, are considered. Focusing on channels motivated by the dark sector models, we carry out a model-independent study of the sensitivities of Z factories in probing exotic decays. The limits on branching ratios of the exotic Z decay are typically Oð10 −6 -10 −8.5 Þ for the Giga Z and Oð10 −7.5 -10 −11 Þ for the Tera Z, and they are compared with the projection for the high luminosity LHC. We demonstrate that future Z factories can provide its unique and leading sensitivity and highlight the complementarity with other experiments, including the indirect and direct dark matter search limits and the existing collider limits. Future Z factories will play a leading role in uncovering the hidden sector of the Universe in the future.

show abstract

Search for anomalous Z → γγγ events at LEP

Cited by 63 publications

References 13 publications

Theoretical and Experimental Status of Magnetic Monopoles

Theoretical and Experimental Status of Magnetic Monopoles

ALPs at colliders

Exposing the dark sector with future Z factories

Contact Info

Product

Resources

About