Exploring sizable triple Higgs couplings in the 2HDM

An important task at future colliders is the measurement of the triple Higgs coupling. Depending on its size relative to the Standard Model (SM) value, certain collider options result in a higher experimental accuracy. Within the framework of Two Higgs Doublet Models (2HDM) type I and II we investigate the allowed ranges for all triple Higgs couplings involving at least one light, SM-like Higgs boson. We take into account theoretical constraints (unitarity, stability), experimental constraints from direct Higgs-boson searches, measurements of the SM-like Higgs-boson properties, flavor observables and electroweak precision data. We find that the SM-type triple Higgs coupling w.r.t. its SM value, $\lambda_{hhh}/\lambda_{\rm SM}$, can range between $\sim -0.5$ and $\sim 1.5$. Depending on which value is realized, the HL-LHC can compete with, or is clearly inferior to the ILC. We find the coupling $\lambda_{hhH}$ between $\sim -1.5$ and $\sim 1.5$. Triple Higgs couplings involving two heavy Higgs bosons, $\lambda_{hHH}$, $\lambda_{hAA}$ and $\lambda_{hH^+H^-}$ can reach values up to ${\cal O}(10)$, roughly independent of the 2HDM type. This can lead to potentially strongly enhanced production of two Higgs-bosons at the HL-LHC or high-energy $e^+e^-$ colliders.Comment: 44 pages, 16 figure

New Constraints on General Slepton Flavor Mixing

We explore the phenomenological implications on charged lepton flavor violating (LFV) processes from slepton flavor mixing within the Minimal Supersymmetric Standard Model. We work under the model-independent hypothesis of general flavor mixing in the slepton sector, being parametrized by a complete set of dimensionless delta^AB_ij (A,B = L,R; i,j = 1, 2, 3) parameters. The present upper bounds on the most relevant LFV processes, together with the requirement of compatibility in the choice of the MSSM parameters with the recent LHC and (g-2) data, lead to updated constraints on all slepton flavor mixing parameters. A comparative discussion of the most effective LFV processes to constrain the various generation mixings is included.Comment: 42 pages, 19 figures. Minor changes, version to appear in PR

Updated Constraints on General Squark Flavor Mixing

We explore the phenomenological implications on non-minimal flavor violating (NMFV) processes from squark flavor mixing within the Minimal Supersymmetric Standard Model. We work under the model-independent hypothesis of general flavor mixing in the squark sector, being parametrized by a complete set of dimensionless delta^AB_ij (A,B = L, R; i,j = u, c, t or d, s, b) parameters. The present upper bounds on the most relevant NMFV processes, together with the requirement of compatibility in the choice of the MSSM parameters with the recent LHC and g-2 data, lead to updated constraints on all squark flavor mixing parameters.Comment: 30 pages, 7 figures. arXiv admin note: text overlap with arXiv:1304.2783, arXiv:1109.623

Masgomas-4: Physical characterization of a double-core obscured cluster with a massive and very young stellar population

The discovery of new, obscured massive star clusters has changed our understanding of the Milky Way star-forming activity from a passive to a very active star-forming machine. The search for these obscured clusters is strongly supported by the use of all-sky, near-IR surveys. The main goal of the MASGOMAS project is to search for and study unknown, young, and massive star clusters in the Milky Way, using near-IR data. Here we try to determine the main physical parameters (distance, size, total mass, and age) of Masgomas-4, a new double-core obscured cluster. Using near-IR photometry ($J$, $H$, and $K_S$) we selected a total of 21 stars as OB-type star candidates. Multi-object, near-IR follow-up spectroscopy allowed us to carry out the spectral classification of the OB-type candidates. Of the 21 spectroscopically observed stars, ten are classified as OB-type stars, eight as F- to early G-type dwarf stars, and three as late-type giant stars. Spectroscopically estimated distances indicate that the OB-type stars belong to the same cluster, located at a distance of $1.90^{+1.28}_{-0.90}$ kpc. Our spectrophotometric data confirm a very young and massive stellar population, with a clear concentration of pre-main-sequence massive candidates (Herbig Ae/Be) around one of the cluster cores. The presence of a surrounding HII cloud and the Herbig Ae/Be candidates indicate an upper age limit of 5 Myr.Comment: Accepted for publication in A&

Higgs Boson Masses in the MSSM with Heavy Majorana Neutrinos

We present a full diagrammatic computation of the one-loop corrections from the neutrino/sneutrino sector to the renormalized neutral CP-even Higgs boson self-energies and the lightest Higgs boson mass, Mh, within the context of the so-called MSSM-seesaw scenario. This consists of the Minimal Supersymmetric Standard Model with the addition of massive right handed Majorana neutrinos and their supersymmetric partners, and where the seesaw mechanism is used for the lightest neutrino mass generation. We explore the dependence on all the parameters involved, with particular emphasis in the role played by the heavy Majorana scale. We restrict ourselves to the case of one generation of neutrinos/sneutrinos. For the numerical part of the study, we consider a very wide range of values for all the parameters involved. We find sizeable corrections to Mh, which are negative in the region where the Majorana scale is large (10^{13}-10^{15} GeV) and the lightest neutrino mass is within a range inspired by data (0.1-1 eV). For some regions of the MSSM-seesaw parameter space, the corrections to Mh are substantially larger than the anticipated Large Hadron Collider precision.Comment: Latex, 50 pages, 15 figures, 6 tables. Discussion improved. Comments and some new approximate formulae have been added. Published version on JHE