On the renormalization of the electroweak chiral Lagrangian with a Higgs

We consider the scalar sector of the effective non-linear electroweak Lagrangian with a light "Higgs" particle, up to four derivatives in the chiral expansion. The complete off-shell renormalization procedure is implemented, including one loop corrections stemming from the leading two-derivative terms, for finite Higgs mass. This determines the complete set of independent chiral invariant scalar counterterms required for consistency; these include bosonic operators often disregarded. Furthermore, new counterterms involving the Higgs particle which are apparently chiral non-invariant are identified in the perturbative analysis. A novel general parametrization of the pseudoescalar field redefinitions is proposed, which reduces to the various usual ones for specific values of its parameter; the non-local field redefinitions reabsorbing all chiral non-invariant counterterms are then explicitly determined. The physical results translate into renormalization group equations which may be useful when comparing future Higgs data at different energies

Primordial Black Holes as Generators of Cosmic Structures

Primordial black holes (PBHs) could provide the dark matter in various mass windows below $10^2 M_{\odot}$ and those of $30 M_{\odot}$ might explain the LIGO events. PBHs much larger than this might have important consequences even if they provide only a small fraction of the dark matter. In particular, they could generate cosmological structure either individually through through the `seed' effect or collectively through the `Poisson' effect, thereby alleviating some problems associated with the standard CDM scenario. If the PBHs all have a similar mass and make a small contribution to the dark matter, then the seed effect dominates on small scales, in which case PBHs could seed the supermassive black holes in galactic nuclei or even galaxies themselves. If they have a similar mass and provide the dark matter, the Poisson effect dominates on all scales and the first bound clouds would form earlier than in the usual scenario, with interesting observational consequences. If the PBHs have an extended mass spectrum, which is more likely, they could fulfill all three roles - providing the dark matter, binding the first bound clouds and generating galaxies. In this case, the galactic mass function naturally has the observed form, with the galaxy mass being simply related to the black hole mass. The stochastic gravitational wave background from the PBHs in this scenario would extend continuously from the LIGO frequency to the LISA frequency, offering a potential goal for future surveys.Comment: 48 pages, 3 figures, accepted for publication in Monthly Notices of Royal Astronomical Societ

The minimal linear sigma model for the Goldstone Higgs

In the context of the minimal SO(5) linear {\sigma}-model, a complete renormalizable Lagrangian -including gauge bosons and fermions- is considered, with the symmetry softly broken to SO(4). The scalar sector describes both the electroweak Higgs doublet and the singlet {\sigma}. Varying the {\sigma} mass would allow to sweep from the regime of perturbative ultraviolet completion to the non-linear one assumed in models in which the Higgs particle is a low-energy remnant of some strong dynamics. We analyze the phenomenological implications and constraints from precision observables and LHC data. Furthermore, we derive the d <= 6 effective Lagrangian in the limit of heavy exotic fermions

The Goldstone Boson Higgs and the effective Lagrangian(s)

The Goldstone boson nature of the observed Higgs scalar particle represents a tempting possible solution for the Standard Model hierarchy problem. We first discuss the essence of the problem in the context of low energy QCD and the Higgs sector of the Standard Model. As a step towards the solution we construct a UV complete model of the Goldstone Higgs based on the global $SO(5)/SO(4)$ symmetry breaking. The scalar sector of the theory is a linear sigma model extended by a scalar singlet $\sigma$, with mass $m_\sigma>500$ GeV. In order to give mass to the SM fermions through the partial compositeness mechanism, the fermion sector is extended by heavy vectorlike fermions. We study in detail the possible direct detection of $\sigma$ and the impact of the new scalar and fermion states on Electroweak Precision Tests. We conclude in particular that any reasonable contribution of the scalar sector can in principle be compensated by a fermionic one. At low energies any extension of the Standard Model results in a set of effective operators, describing the deviations of the couplings from their predicted values. %This description is incorporated in the Effective Field Theory (EFT) language. Depending on how the electroweak symmetry is realised, two intrinsically different effective descriptions are possible: linear and non-linear one. Varying the $\sigma$ mass allows to sweep from the regime of the perturbative linear UV completion to the non-linear one. The latter one is typically assumed in models in which the Higgs particle is a low-energy remnant of some strong dynamics at a higher scale. In the limit of large but finite masses of the new states we derive the benchmark non-linear effective Lagrangian. Furthermore the first order linear corrections originating from large, but finite mass of the additional scalar to the Higgs couplings have been derived and they are found to be suppressed by the scalar masses ratio. Finally, we consider the renormalization of the custodial preserving scalar sector of the non-linear effective Lagrangian in a general Goldstone bosons matrix parametrisation and identify the physical counterterms as well as the chiral-noninvariant divergences. The latter ones are shown to be unphysical as they can be removed by a field redefinition. The procedure allows to check the consistency of the non-linear effective Lagrangian at one loop. The results confirm the completeness of the scalar sector of NLO Lagrangian previously identified in the literature

The Penning Discharge Experimental Study and Its Simulation

The influence of the demountable Penning ion source electrodes geometry on the discharge characteristics and extracted ion current is investigated. The extracted currents, ignition potentials and the operational pressure ranges are compared at different anode heights and its arrangement relative to the discharge cell. The use of ring and mesh anodes has allowed to visualize the discharge burning areas and their structure versus the pressure, anode potential and cell geometry. Some PIC simulations of Penning discharge are made in the Vorpal code. The good correspondence between the simulated electron density and plasma glow areas on the photos is shown. The other one-particle simulation has shown that the magnetic field nonuniformity significantly affects the ignition and combustion discharge potentials

Phosphoproteomic analysis identifies supervillin as an ERK3 substrate regulating cytokinesis and cell ploidy

Extracellular signal-regulated kinase 3 (ERK3) is a poorly characterized member of the mitogen-activated protein (MAP) kinase family. Functional analysis of the ERK3 signaling pathway has been hampered by a lack of knowledge about the substrates and downstream effectors of the kinase. Here, we used large-scale quantitative phosphoproteomics and targeted gene silencing to identify direct ERK3 substrates and gain insight into its cellular functions. Detailed validation of one candidate substrate identified the gelsolin/villin family member supervillin (SVIL) as a bona fide ERK3 substrate. We show that ERK3 phosphorylates SVIL on Ser245 to regulate myosin II activation and cytokinesis completion in dividing cells. Depletion of SVIL or ERK3 leads to increased cytokinesis failure and multinucleation, a phenotype rescued by wild type SVIL but not by the non-phosphorylatable S245A mutant. Our results unveil a new function of the atypical MAP kinase ERK3 in cell division and the regulation of cell ploidy

Author response

In eukaryotes, exposure to hypertonic conditions activates a MAPK (Hog1 in Saccharomyces cerevisiae and ortholog p38 in human cells). In yeast, intracellular glycerol accumulates to counterbalance the high external osmolarity. To prevent glycerol efflux, Hog1 action impedes the function of the aquaglyceroporin Fps1, in part, by displacing channel co-activators (Rgc1/2). However, Fps1 closes upon hyperosmotic shock even in hog1∆ cells, indicating another mechanism to prevent Fps1-mediated glycerol efflux. In our prior proteome-wide screen, Fps1 was identified as a target of TORC2-dependent protein kinase Ypk1 (Muir et al., 2014). We show here that Fps1 is an authentic Ypk1 substrate and that the open channel state of Fps1 requires phosphorylation by Ypk1. Moreover, hyperosmotic conditions block TORC2-dependent Ypk1-mediated Fps1 phosphorylation, causing channel closure, glycerol accumulation, and enhanced survival under hyperosmotic stress. These events are all Hog1-independent. Our findings define the underlying molecular basis of a new mechanism for responding to hypertonic conditions. DOI: http://dx.doi.org/10.7554/eLife.09336.00