A search is performed for long-lived particles that decay into final states that include a pair of electrons or a pair of muons. The experimental signature is a distinctive topology consisting of a pair of charged leptons originating from a displaced secondary vertex. Events corresponding to an integrated luminosity of 19.6(20.5)fb-1 in the electron (muon) channel were collected with the CMS detector at the CERN LHC in proton-proton collisions at s=8TeV. No significant excess is observed above standard model expectations. Upper limits on the product of the cross section and branching fraction of such a signal are presented as a function of the long-lived particle's mean proper decay length. The limits are presented in an approximately model-independent way, allowing them to be applied to a wide class of models yielding the above topology. Over much of the investigated parameter space, the limits obtained are the most stringent to date. In the specific case of a model in which a Higgs boson in the mass range 125-1000GeV/c2 decays into a pair of long-lived neutral bosons in the mass range 20-350GeV/c2, each of which can then decay to dileptons, the upper limits obtained are typically in the range 0.2-10 fb for mean proper decay lengths of the long-lived particles in the range 0.01-100 cm. In the case of the lowest Higgs mass considered (125GeV/c2), the limits are in the range 2-50 fb. These limits are sensitive to Higgs boson branching fractions as low as 10-4.

Khachatryan, V., Sirunyan, A., Tumasyan, A., Adam, W., Bergauer, T., Dragicevic, M., et al. (2015). Search for long-lived particles that decay into final states containing two electrons or two muons in proton-proton collisions at s =8TeV. PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY, 91(5) [10.1103/PhysRevD.91.052012].

Search for long-lived particles that decay into final states containing two electrons or two muons in proton-proton collisions at s =8TeV

DINARDO, MAURO EMANUELE;FIORENDI, SARA;GEROSA, RAFFAELE ANGELO;GHEZZI, ALESSIO;GOVONI, PIETRO;LUCCHINI, MARCO TOLIMAN;MANZONI, RICCARDO ANDREA;MARTELLI, ARABELLA;MARZOCCHI, BADDER;MORONI, LUIGI;PAGANONI, MARCO;RAGAZZI, STEFANO;TABARELLI DE FATIS, TOMMASO;Branca, A;De Guio, F;
2015

Abstract

A search is performed for long-lived particles that decay into final states that include a pair of electrons or a pair of muons. The experimental signature is a distinctive topology consisting of a pair of charged leptons originating from a displaced secondary vertex. Events corresponding to an integrated luminosity of 19.6(20.5)fb-1 in the electron (muon) channel were collected with the CMS detector at the CERN LHC in proton-proton collisions at s=8TeV. No significant excess is observed above standard model expectations. Upper limits on the product of the cross section and branching fraction of such a signal are presented as a function of the long-lived particle's mean proper decay length. The limits are presented in an approximately model-independent way, allowing them to be applied to a wide class of models yielding the above topology. Over much of the investigated parameter space, the limits obtained are the most stringent to date. In the specific case of a model in which a Higgs boson in the mass range 125-1000GeV/c2 decays into a pair of long-lived neutral bosons in the mass range 20-350GeV/c2, each of which can then decay to dileptons, the upper limits obtained are typically in the range 0.2-10 fb for mean proper decay lengths of the long-lived particles in the range 0.01-100 cm. In the case of the lowest Higgs mass considered (125GeV/c2), the limits are in the range 2-50 fb. These limits are sensitive to Higgs boson branching fractions as low as 10-4.
Articolo in rivista - Articolo scientifico
Nuclear and High Energy Physics
English
Khachatryan, V., Sirunyan, A., Tumasyan, A., Adam, W., Bergauer, T., Dragicevic, M., et al. (2015). Search for long-lived particles that decay into final states containing two electrons or two muons in proton-proton collisions at s =8TeV. PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY, 91(5) [10.1103/PhysRevD.91.052012].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/153602
Citazioni
  • Scopus 96
  • ???jsp.display-item.citation.isi??? 34
Social impact