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Lightest-neutralino Decays in R-p-violating Models with Dominant lambda' and lambda Couplings
Auteur(s): Kneur J.-L., Borzumati F., Godbole R.M., Takayama F.
(Article) Publié:
Journal Of High Energy Physics, vol. 7 p.037 - (2002)
Texte intégral en Openaccess :
Ref Arxiv: hep-ph/0108244
DOI: 10.1088/1126-6708/2002/07/037
Ref. & Cit.: NASA ADS
Résumé: Decays of the lightest neutralino are studied in Rp-violating models with operators λ'LQDc and λLLEc involving third-generation matter fields and with dominant λ' and λ couplings. Generalizations to decays of the lightest neutralino induced by subdominant λ' and λ couplings are straightforward. Decays with the top-quark among the particles produced are considered, in addition to those with an almost massless final state. Phenomenological analyses for examples of both classes of decays are presented. No specific assumption on the composition of the lightest neutralino is made, and the formulae listed here can be easily generalized to study decays of heavier neutralinos. It has been recently pointed out that, for a sizable coupling λ'333, tau-sleptons may be copiously produced at the LHC as single supersymmetric particles, in association with top- and bottom-quark pairs. This analysis of neutralino decays is, therefore, a first step towards the reconstruction of the complete final state produced in this case.
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Probing the SUSY Higgs Boson Couplings to Scalar Leptons at High-energy e+e- Colliders
Auteur(s): Datta A., Djouadi Abdelhak, Kneur J.-L.
(Article) Publié:
Physics Letters B, vol. 509 p.299-306 (2001)
Texte intégral en Openaccess :
Ref Arxiv: hep-ph/0101353
DOI: 10.1016/S0370-2693(01)00533-0
WoS: 000169426400015
Ref. & Cit.: NASA ADS
12 Citations
Résumé: We discuss the production at $e^+e^-$ colliders of Higgs bosons in association with both the scalar leptons and the lightest neutralinos in the Minimal Supersymmetric extension of the Standard Model. While the rates for associated Higgs production with neutralinos and first/second generation sleptons are rather tiny, the cross section for the production of the lightest Higgs boson $h$ with scalar $\tau$ lepton pairs can reach the femtobarn level at c.m. energies at and above 500 GeV in favorable regions of the parameter space, making this process potentially detectable at a high-luminosity $\ee$ collider, in particular in the $\gamma \gamma$ option. This would provide a determination of the $h \tilde{\tau} \tilde{\tau}$ coupling and opens up the possibility of measuring the parameter $\tan \beta$.
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Toward convergence of the variational mass expansion in asymptotically free theories
Auteur(s): Kneur J.-L., Reynaud D
Conference: 30th International Conference on High Energy Physics (OSAKA, JP, 2000-07-27)
Actes de conférence: HIGH ENERGY PHYSICS, VOLS I AND II, vol. p.1344-1346 (2001)
Ref HAL: hal-00703764_v1
Exporter : BibTex | endNote
Résumé: We re-examine a modification of perturbative expansions, valid for asymptotically free theories, producing "variationally improved" expansions of physical quantities relevant to dynamical (chiral) symmetry breaking. The large order behaviour of this expansion is shown to be drastically improved, for reasons analogous to the convergence properties of the delta-expansion of the anharmonic oscillator.
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Report of the Tevatron Higgs Working Group
Auteur(s): Carena M., Kneur J.-L., Conway J.s., Haber H.e., Hobbs J.d.
(Document sans référence bibliographique) 2000-12-06Texte intégral en Openaccess :
Ref Arxiv: hep-ph/0010338
Ref. & Cit.: NASA ADS
Résumé: This report presents the theoretical analysis relevant for Higgs physics at the upgraded Tevatron collider and documents the Higgs Working Group simulations to estimate the discovery reach in Run 2 for the Standard Model and MSSM Higgs bosons. Based on a simple detector simulation, we have determined the integrated luminosity necessary to discover the SM Higgs in the mass range 100-190 GeV. The first phase of the Run 2 Higgs search, with a total integrated luminosity of 2 fb-1 per detector, will provide a 95% CL exclusion sensitivity comparable to that expected at the end of the LEP2 run. With 10 fb-1 per detector, this exclusion will extend up to Higgs masses of 180 GeV, and a tantalizing 3 sigma effect will be visible if the Higgs mass lies below 125 GeV. With 25 fb-1 of integrated luminosity per detector, evidence for SM Higgs production at the 3 sigma level is possible for Higgs masses up to 180 GeV. However, the discovery reach is much less impressive for achieving a 5 sigma Higgs boson signal. Even with 30 fb-1 per detector, only Higgs bosons with masses up to about 130 GeV can be detected with 5 sigma significance. These results can also be re-interpreted in the MSSM framework and yield the required luminosities to discover at least one Higgs boson of the MSSM Higgs sector. With 5-10 fb-1 of data per detector, it will be possible to exclude at 95% CL nearly the entire MSSM Higgs parameter space, whereas 20-30 fb-1 is required to obtain a 5 sigma Higgs discovery over a significant portion of the parameter space. Moreover, in one interesting region of the MSSM parameter space (at large tan(beta)), the associated production of a Higgs boson and a b b-bar pair is significantly enhanced and provides potential for discovering a non-SM-like Higgs boson in Run 2.
Commentaires: 185 pages, 124 figures, 55 tables
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Toward Convergence of the Variational Mass Expansive in Asymptotically Free Theories
Auteur(s): Kneur J.-L., Reynaud D.
Conference: HIGH ENERGY PHYSICS ICHEP 2000 (Osaka, JP, 2000-07-27)
Actes de conférence: Proceedings of the 30th International Conference ICHEP 2000, vol. 2 p.1344 (2000)
Ref HAL: hal-00308160_v1
Exporter : BibTex | endNote
Résumé: We re-examine a modification of perturbative expansions, valid for asymptotically free theories, producing variationally improved expansion of physical quantities relevant to dynamical (chiral) symmetry breaking. The large order behaviour of this expansion is shown to be drastically improved, for reasons analogous to the convergence properties of the delta-expansion of the anharmonic oscillator.
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Some Topics in the Determination of MSSM Parameters
Auteur(s): Kneur J.-L.
Conference: (, , 0000)
Actes de conférence: 4emes Rencontres Hanoi(Vietnam), 2000-Van Hieu N &Tran Thanh Van Eds, vol. p.- (2001)
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Toward Convergence of the Variational Mass Expansion and Chiral Symmetry Breaking Parameters
Auteur(s): Kneur J.-L., Reynaud D.
Conference: QCD 00 8th High-Energy Physics International Conference on Quantum ChromoDynamics (Montpellier, FR, 2000-07-03)
Actes de conférence: Nuclear Physics B - Proceedings Supplements, vol. 96 p.255-258 (2001)
Texte intégral en Openaccess :
Ref HAL: hal-00268377_v1
DOI: 10.1016/S0920-5632(01)01138-0
WoS: 000168045000040
Exporter : BibTex | endNote
Résumé: We re-examine a modification of perturbative expansions, valid for asymptotically free theories, producing variationally improved expansions of physical quantities relevant to dynamical (chiral) symmetry breaking. The large order behaviour of this expansion is drastically improved, with respect to the original perturbative expansion (making the series at least Borel summable, in a certain range of renormalization scheme parameters). We argue that non-perturbative estimates of the order parameters of QCD chiral symmetry breaking are therefore possible in this framework.
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