1,573 research outputs found
One-loop non-renormalization results in EFTs
In Effective Field Theories (EFTs) with higher-dimensional operators many
anomalous dimensions vanish at the one-loop level for no apparent reason. With
the use of supersymmetry, and a classification of the operators according to
their embedding in super-operators, we are able to show why many of these
anomalous dimensions are zero. The key observation is that one-loop
contributions from superpartners trivially vanish in many cases under
consideration, making supersymmetry a powerful tool even for non-supersymmetric
models. We show this in detail in a simple U(1) model with a scalar and
fermions, and explain how to extend this to SM EFTs and the QCD Chiral
Langrangian. This provides an understanding of why most "current-current"
operators do not renormalize "loop" operators at the one-loop level, and allows
to find the few exceptions to this ubiquitous rule.Comment: Corrections made in Sec. 3.2 and Fig.
Renormalization of dimension-six operators relevant for the Higgs decays
The discovery of the Higgs boson has opened a new window to test the SM
through the measurements of its couplings. Of particular interest is the
measured Higgs coupling to photons which arises in the SM at the one-loop
level, and can then be significantly affected by new physics. We calculate the
one-loop renormalization of the dimension-six operators relevant for
, which can be potentially important since
it could, in principle, give log-enhanced contributions from operator mixing.
We find however that there is no mixing from any current-current operator that
could lead to this log-enhanced effect. We show how the right choice of
operator basis can make this calculation simple. We then conclude that
can only be affected by RG mixing from
operators whose Wilson coefficients are expected to be of one-loop size, among
them fermion dipole-moment operators which we have also included.Comment: 21 pages. Improved version with h -> gamma Z results added and
structure of anomalous-dimension matrix determined further. Conclusions
unchange
Higgs Inflation as a Mirage
We discuss a simple unitarization of Higgs inflation that is genuinely weakly
coupled up to Planckian energies. A large non-minimal coupling between the
Higgs and the Ricci curvature is induced dynamically at intermediate energies,
as a simple ratio of mass scales. Despite not being dominated by the Higgs
field, inflationary dynamics simulates the `Higgs inflation' one would get by
blind extrapolation of the low-energy effective Lagrangian, at least
qualitatively. Hence, Higgs inflation arises as an approximate `mirage' picture
of the true dynamics. We further speculate on the generality of this phenomenon
and show that, if Higgs-inflation arises as an effective description, the
details of the UV completion are necessary to extract robust quantitative
predictions.Comment: 21 pages, 2 figure
Habitat requirements and conservation needs of peripheral populations : the case of the great crested newt (Triturus cristatus) in the Scottish Highlands
Edge populations are of conservation importance because of their roles as reservoirs of evolutionary potential and in understanding a given species’ ecological needs. Mainly due to loss of aquatic breeding sites, the great crested newt Triturus cristatus is amongst the fastest declining amphibian species in Europe. Focusing on the north-westerly limit of the T. cristatus range, in the Scottish Highlands, we aimed to characterise habitat requirements and conservation needs of an isolated set of edge populations. We recorded 129 breeding-pond related environmental parameters, and used a variable-selection procedure followed by random forest analysis to build a predictive model for the species’ present occurrence, as well as for population persistence incorporating data on population losses. The most important variables predicting T. cristatus occurrence and persistence were associated with pond quality, pond shore and surrounding terrestrial habitat (especially mixed Pinus sylvestris - Betula woodland), and differed from those identified in the species’ core range. We propose that habitat management and pond creation should focus on the locally most favourable habitat characteristics to improve the conservation status and resilience of populations. This collaborative work, between conservation agencies and scientific researchers, is presented as an illustrative example of linking research, management and conservation
Ground reaction forces, asymmetries and performance of change of direction tasks in youth elite female basketball players
The magnitude and direction of inter-limb asymmetries in a change of direction (COD) have increased interest in scientific research in recent years. This present study aimed to investigate the magnitude of asymmetries in an elite youth female basketball sample (n = 18, age = 17.79 ± 0.67 y)
and determine its directionality using force platform technology. Participants performed 70◦ and 180◦ COD tests analyzing the following variables: time, ground contact time (GCT) and ground reaction forces (GRF) along the anterior–posterior, mediolateral, and vertical axes. Inter-limb asymmetries were evident in both COD tests, with substantial differences observed between limbs (p < 0.01). The asymmetry values ranged from 3.02% to 24.31% in COD 180◦ and from 1.99% to 21.70% in COD 70◦, with anterior–posterior GRF consistently exhibiting the highest asymmetry magnitude. Additionally, the directionality exhibited variability between the tests, indicating poor agreement and suggesting
the independent directionality of asymmetries across tasks. Moreover, players required more time to complete the COD 180â—¦, the GCT was noticeably longer for the COD 180â—¦
than for the COD 70â—¦, and GRF varied across the axis, suggesting that players adapt uniquely to the specific demands of each task. The utilization of force platforms presents a comprehensive approach to assess asymmetries and
COD variables performance variables which are “angle-dependent”, which could have important implications for COD screening and effective training interventions
User quality of experience of mulsemedia applications
User Quality of Experience (QoE) is of fundamental importance in multimedia applications and has been extensively studied for decades. However, user QoE in the context of the emerging multiple-sensorial media (mulsemedia) services, which involve different media components than the traditional multimedia applications, have not been comprehensively studied. This article presents the results of subjective tests which have investigated user perception of mulsemedia content. In particular, the impact of intensity of certain mulsemedia components including haptic and airflow on user-perceived experience are studied. Results demonstrate that by making use of mulsemedia the overall user enjoyment levels increased by up to 77%
SuDS and amphibians - are constructed wetlands really benefitting nature and people?
While urbanisation is a major threat to global
biodiversity, it also brings opportunities for some
species. Sustainable Drainage Systems (SuDS) have
been installed in all Scottish cities to reduce flood
and pollution risk and they can also offer new
habitats for wildlife. We studied SuDS in Inverness
and the Scottish Central Belt to assess their value as
amphibian breeding sites, habitats, and as places
where urban people can experience nature. The
nine-year study revealed that many SuDS were of
similar ecological quality to wider countryside ponds
but that the quality of ponds is not equitably
distributed between neighbourhoods inhabited by
different socio-economic classes. However, the
findings suggest ways to improve the design and
management of SuDS for people and nature, making
access to high quality ponds available to all social
groups
Leisure, Use of Leisure Time, and Forms of Recreation in Rural Communities
The article is based on the results of an investigation carried out in the
coastal village of Filip Jakov in summer 1967.
Like most villages in the coastal belt Filip Jakov too has benefited from the
development of the tourist trade in recent years. As a result, the inhabitants’ daily
programme for spending their leisure time, the traditional forms and manners of
recreation have underwent certain changes.
The author discusses the general difference between the daily rhythm of life
and work in rural and urban communities and goes on to describe the characteristics
of the village, its inhabitants, and the persons interviewed (heads of households).
He discusses in particular the various form and manners in which the
inhabitants spend their free time both on working days and, especially, on Sunday
and holidays and during their annual leave.
A compaaraison between the pre-war and current forms in which free time is
spent shows that various popular forms of entertainment (social events, singing,
j eel dancing, etc.) have disappeared to be replaced primarily by mass communication
media (radio, TV, cinema). However, many traditional forms of recreation
still survive such as card playing, ball games, social conversation, etc. which have
always been a feature oi social life in Mediterranean communities
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