20,733 research outputs found
Probing the strange Higgs coupling at lepton colliders using light-jet flavor tagging
We propose a method to probe the coupling of the Higgs to strange quarks by
tagging strange jets at future lepton colliders. For this purpose we describe a
jet-flavor observable, , that is correlated with the flavor of the quark
associated with the hard part of the jet. Using this variable, we set up a
strangeness tagger aimed at studying the decay . We determine
the sensitivity of our method to the strange Yukawa coupling, and find it to be
of the order of the standard-model expectation.Comment: 6 pages, v2 accepted for publication in PR
Squark-mediated Higgs+jets production at the LHC
We investigate possible scenarios of light-squark production at the LHC as a
new mechanism to produce Higgs bosons in association with jets. The study is
motivated by the SUSY search for H+jets events, performed by the CMS
collaboration on 8 and 13 TeV data using the razor variables. Two simplified
models are proposed to interpret the observations in this search. The
constraint from Run I and the implications for Run II and beyond are discussed
Gluon and Ghost Dynamics from Lattice QCD
The two point gluon and ghost correlation functions and the three gluon
vertex are investigated, in the Landau gauge, using lattice simulations. For
the two point functions, we discuss the approach to the continuum limit looking
at the dependence on the lattice spacing and volume. The analytical structure
of the propagators is also investigated by computing the corresponding spectral
functions using an implementation of the Tikhonov regularisation to solve the
integral equation. For the three point function we report results when the
momentum of one of the gluon lines is set to zero and discuss its implications.Comment: Proceedings of Light Cone 2016, held in Lisbon, September 2016. Minor
changes in text. To appear in Few B Sy
What controls the large-scale magnetic fields of M dwarfs?
Observations of active M dwarfs show a broad variety of large-scale magnetic
fields encompassing dipole-dominated and multipolar geometries. We detail the
analogy between some anelastic dynamo simulations and spectropolarimetric
observations of 23 M stars. In numerical models, the relative contribution of
inertia and Coriolis force in the global force balance -estimated by the
so-called local Rossby number- is known to have a strong impact on the magnetic
field geometry. We discuss the relevance of this parameter in setting the
large-scale magnetic field of M dwarfs.Comment: 4 pages, 3 figures, conference proceeding, IAUS 302 'Magnetic Fields
Throughout the Stellar Evolution', (26-30 Aug 2013, Biarritz, France
Explaining Jupiter's magnetic field and equatorial jet dynamics
Spacecraft data reveal a very Earth-like Jovian magnetic field. This is
surprising since numerical simulations have shown that the vastly different
interiors of terrestrial and gas planets can strongly affect the internal
dynamo process. Here we present the first numerical dynamo that manages to
match the structure and strength of the observed magnetic field by embracing
the newest models for Jupiter's interior. Simulated dynamo action primarily
occurs in the deep high electrical conductivity region while zonal flows are
dynamically constrained to a strong equatorial jet in the outer envelope of low
conductivity. Our model reproduces the structure and strength of the observed
global magnetic field and predicts that secondary dynamo action associated to
the equatorial jet produces banded magnetic features likely observable by the
Juno mission. Secular variation in our model scales to about 2000 nT per year
and should also be observable during the one year nominal mission duration.Comment: 7 pages, 4 figures, accepted for publication in Geophysical Research
Letter
Learning roadmaps for Higher Education
An integrated platform for the support of teaching activities as been developed and deployed at the Aveiro Norte Polytechnic School of the University of Aveiro. In this paper we present an approach to Learning Roadmaps for Higher Education based on this platform. The aprend.e platform – Electronic Integrated System for Learning and Training - has at its core a Learning Management System with a number of plugins. It represents a new challenge for the University of Aveiro for higher education and is already being at its core is the concept of learning roadmaps that act upon two fundamental axes: education and learning. For the teachers, it aims at becoming a self-supporting tool that stimulates the organization and management of the course materials (lectures, presentations, multimedia content, and evaluation materials, amongst others). For the students, the learning roadmap aims at promoting self-study and supervised study, endowing the pupil with the capabilities to find the relevant information and to capture the concepts in the study materials. The outcome will be a stimulating learning process together with an organized management of those materials
What controls the magnetic geometry of M dwarfs?
Context: observations of rapidly rotating M dwarfs show a broad variety of
large-scale magnetic fields encompassing dipole-dominated and multipolar
geometries. In dynamo models, the relative importance of inertia in the force
balance -- quantified by the local Rossby number -- is known to have a strong
impact on the magnetic field geometry. Aims: we aim to assess the relevance of
the local Rossby number in controlling the large-scale magnetic field geometry
of M dwarfs. Methods: we explore the similarities between anelastic dynamo
models in spherical shells and observations of active M-dwarfs, focusing on
field geometries derived from spectropolarimetric studies. To do so, we
construct observation-based quantities aimed to reflect the diagnostic
parameters employed in numerical models. Results: the transition between
dipole-dominated and multipolar large-scale fields in early to mid M dwarfs is
tentatively attributed to a Rossby number threshold. We interpret late M dwarfs
magnetism to result from a dynamo bistability occurring at low Rossby number.
By analogy with numerical models, we expect different amplitudes of
differential rotation on the two dynamo branches.Comment: 4 pages, 4 figures, accepted for publication in A&
Tightening the belt: Constraining the mass and evolution in SDC335
Recent ALMA observations identified one of the most massive star-forming
cores yet observed in the Milky Way; SDC335-MM1, within the infrared dark cloud
SDC335.579-0.292. Along with an accompanying core MM2, SDC335 appears to be in
the early stages of its star formation process. In this paper we aim to
constrain the properties of the stars forming within these two massive
millimetre sources. Observations of SDC335 at 6, 8, 23 and 25GHz were made with
the ATCA. We report the results of these continuum measurements, which combined
with archival data, allow us to build and analyse the spectral energy
distributions (SEDs) of the compact sources in SDC335. Three HCHII regions
within SDC335 are identified, two within the MM1 core. For each HCHII region, a
free-free emission curve is fit to the data allowing the derivation of the
sources' emission measure, ionising photon flux and electron density. Using
these physical properties we assign each HCHII region a ZAMS spectral type,
finding two protostars with characteristics of spectral type B1.5 and one with
a lower limit of B1-B1.5. Ancillary data from infrared to mm wavelength are
used to construct free-free component subtracted SEDs for the mm-cores,
allowing calculation of the bolometric luminosities and revision of the
previous gas mass estimates. The measured luminosities for the two mm-cores are
lower than expected from accreting sources displaying characteristics of the
ZAMS spectral type assigned to them. The protostars are still actively
accreting, suggesting that a mechanism is limiting the accretion luminosity, we
present the case for two different mechanisms capable of causing this. Finally,
using the ZAMS mass values as lower limit constraints, a final stellar
population for SDC335 was synthesised finding SDC335 is likely to be in the
process of forming a stellar cluster comparable to the Trapezium Cluster and
NGC6334 I(N).Comment: 10 pages, 5 figures. Accepted for publication in A&
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