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- Bechtle, P., et al.
(author)
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MSSM interpretations of the LHC discovery : light or heavy Higgs?
- 2013
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In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 73:4, s. 2354-
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Journal article (peer-reviewed)abstract
- A Higgs-like particle with a mass of about 126 GeV has been discovered at the LHC. Within the experimental uncertainties, the measured properties of this new state are compatible with those of the Higgs boson in the Standard Model (SM). While not statistically significant at present, the results show some interesting patterns of deviations from the SM predictions, in particular a higher rate in the gamma gamma decay mode observed by ATLAS and CMS, and a somewhat smaller rate in the tau(+)tau(-) mode. The LHC discovery is also compatible with the predictions of the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM), interpreting the new state as either the light or the heavy CP-even MSSM Higgs boson. Within the framework of the MSSM with seven free parameters (pMSSM-7), we fit the various rates of cross section times branching ratio as measured by the LHC and Tevatron experiments under the hypotheses of either the light or the heavy CP-even Higgs boson being the new state around 126 GeV, with and without the inclusion of further low-energy observables. We find an overall good quality of the fits, with the best fit points exhibiting an enhancement of the gamma gamma rate, as well as a small suppression of the b (b) over bar and tau(+)tau(-) channels with respect to their SM expectations, depending on the details of the fit. For the fits including the whole dataset the light CP-even Higgs interpretation in the MSSM results in a higher relative fit probability than the SM fit. On the other hand, we find that the present data also permit the more exotic interpretation in terms of the heavy CP-even MSSM Higgs, which could give rise to experimental signatures of additional Higgs states in the near future.
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| 2. |
- Carena, M., et al.
(author)
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MSSM Higgs boson searches at the LHC : benchmark scenarios after the discovery of a Higgs-like particle
- 2013
-
In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 73:9, s. 2552-
-
Journal article (peer-reviewed)abstract
- A Higgs-like particle with a mass of about 125.5 GeV has been discovered at the LHC. Within the current experimental uncertainties, this new state is compatible with both the predictions for the Standard Model (SM) Higgs boson and with the Higgs sector in the Minimal Supersymmetric Standard Model (MSSM). We propose new low-energy MSSM benchmark scenarios that, over a wide parameter range, are compatible with the mass and production rates of the observed signal. These scenarios also exhibit interesting phenomenology for the MSSM Higgs sector. We propose a slightly updated version of the well-known scenario, and a modified scenario (), where the light -even Higgs boson can be interpreted as the LHC signal in large parts of the M (A) -tan beta plane. Furthermore, we define a light stop scenario that leads to a suppression of the lightest -even Higgs gluon fusion rate, and a light stau scenario with an enhanced decay rate of h ->gamma gamma at large tan beta. We also suggest a tau-phobic Higgs scenario in which the lightest Higgs can have suppressed couplings to down-type fermions. We propose to supplement the specified value of the mu parameter in some of these scenarios with additional values of both signs. This has a significant impact on the interpretation of searches for the non-SM-like MSSM Higgs bosons. We also discuss the sensitivity of the searches to heavy Higgs decays into light charginos and neutralinos, and to decays of the form H -> hh. Finally, in addition to all the other scenarios where the lightest -even Higgs is interpreted as the LHC signal, we propose a low-M (H) scenario, where instead the heavy -even Higgs boson corresponds to the new state around 125.5 GeV.
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