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Barenboim, G., Bosch, C., Lopez-Ibañez, M. L., & Vives, O. (2013). Eviction of a 125 GeV “heavy”-Higgs from the MSSM. J. High Energy Phys., 11(11), 051–39pp.
Abstract: We prove that the present experimental constraints are already enough to rule out the possibility of the similar to 125 GeV Higgs found at LHC being the second lightest Higgs in a general MSSM context, even with explicit CP violation in the Higgs potential. Contrary to previous studies, we are able to eliminate this possibility analytically, using simple expressions for a relatively small number of observables. We show that the present LHC constraints on the diphoton signal strength, tau tau production through Higgs and BR(B -> X-s gamma) are enough to preclude the possibility of H-2 being the observed Higgs with m(H) similar or equal to 125 GeV within an MSSM context, without leaving room for finely tuned cancellations. As a by-product, we also comment on the difficulties of an MSSM interpretation of the excess in the gamma gamma production cross section recently found at CMS that could correspond to a second Higgs resonance at m(H) similar or equal to 136 GeV.
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Celis, A., Ilisie, V., & Pich, A. (2013). Towards a general analysis of LHC data within two-Higgs-doublet models. J. High Energy Phys., 12(12), 095–32pp.
Abstract: The data accumulated so far confirm the Higgs-like nature of the new boson discovered at the LHC. The Standard Model Higgs hypothesis is compatible with the collider results and no significant deviations from the Standard Model have been observed neither in the flavour sector nor in electroweak precision observables. We update the LHC and Tevatron constraints on CP-conserving two-Higgs-doublet models without tree-level flavour-changing neutral currents. While the relative sign between the top Yukawa and the gauge coupling of the 126 GeV Higgs is found be the same as in the SM, at 90% CL, there is a sign degeneracy in the determination of its bottom and tau Yukawa couplings. This results in several disjoint allowed regions in the parameter space. We show how generic sum rules governing the scalar couplings determine the properties of the additional Higgs bosons in the different allowed regions. The role of electroweak precision observables, low-energy flavour constraints and LHC searches for additional scalars to further restrict the available parameter space is also discussed.
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Mitsou, V. A. (2013). Shedding light on dark matter at colliders. Int. J. Mod. Phys. A, 28(31), 1330052–34pp.
Abstract: Dark matter remains one of the most puzzling mysteries in Fundamental Physics of our times. Experiments at high-energy physics colliders are expected to shed light to its nature and determine its properties. This review focuses on recent searches for dark matter signatures at the Large Hadron Collider, also discussing related prospects in future e(+)e(-) colliders.
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Barenboim, G., & Rasero, J. (2014). Structure formation during an early period of matter domination. J. High Energy Phys., 04(4), 138–17pp.
Abstract: In this work we show that modifying the thermal history of the Universe by including an early period of matter domination can lead to the formation of astronomical objects. However, the survival of these objects can only be possible if the dominating matter decays to a daughter particle which is not only almost degenerate with the parent particle but also has an open annihilation channel. This requirement translates in an upper bound for the coupling of such a channel and makes the early structure formation viable.
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Li, X. Q., Lu, J., & Pich, A. (2014). Bs,d(0) -> l(+)l(-) decays in the aligned two-Higgs-doublet model. J. High Energy Phys., 06(6), 022–39pp.
Abstract: The rare decays B-s,d(0) -> l(+)l(-) are analyzed within the general framework of the aligned two-Higgs doublet model. We present a complete one-loop calculation of the relevant short-distance Wilson coefficients, giving a detailed technical summary of our results and comparing them with previous calculations performed in particular limits or approximations. We investigate the impact of various model parameters on the branching ratios and study the phenomenological constraints imposed by present data.
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