1,145 research outputs found
BFKL Azimuthal Imprints in Inclusive Three-jet Production at 7 and 13 TeV
We propose the study of new observables in LHC inclusive events with three
tagged jets, one in the forward direction, one in the backward direction and
both well-separated in rapidity from the each other (Mueller-Navelet jets),
together with a third jet tagged in central regions of rapidity. Since
non-tagged associated mini-jet multiplicity is allowed, we argue that
projecting the cross sections on azimuthal-angle components can provide several
distinct tests of the BFKL dynamics. Realistic LHC kinematical cuts are
introduced.Comment: 17 pages, 7 figure
Inclusive Four-jet Production at 7 and 13 TeV: Azimuthal Profile in Multi-Regge Kinematics
Recently, new observables in LHC inclusive events with three tagged jets were
proposed. Here, we extend that proposal to events with four tagged jets. The
events are characterised by one jet in the forward direction, one in the
backward direction with a large rapidity distance from the first one and
two more jets tagged in more central regions of the detector. In our setup,
non-tagged associated mini-jet multiplicity is present and needs to be
accounted for by the inclusion of BFKL gluon Green functions. The projection of
the cross section on azimuthal-angle components opens up the opportunity for
defining new ratios of correlation functions of the azimuthal angle differences
among the tagged jets that can be used as probes of the BFKL dynamics.Comment: 19 pages, 8 figures; v2: published versio
Conditional Image-Text Embedding Networks
This paper presents an approach for grounding phrases in images which jointly
learns multiple text-conditioned embeddings in a single end-to-end model. In
order to differentiate text phrases into semantically distinct subspaces, we
propose a concept weight branch that automatically assigns phrases to
embeddings, whereas prior works predefine such assignments. Our proposed
solution simplifies the representation requirements for individual embeddings
and allows the underrepresented concepts to take advantage of the shared
representations before feeding them into concept-specific layers. Comprehensive
experiments verify the effectiveness of our approach across three phrase
grounding datasets, Flickr30K Entities, ReferIt Game, and Visual Genome, where
we obtain a (resp.) 4%, 3%, and 4% improvement in grounding performance over a
strong region-phrase embedding baseline.Comment: ECCV 2018 accepted pape
Azimuthal-angle Observables in Inclusive Three-jet Production
We discuss the impact of corrections beyond the leading-logarithmic accuracy
on some recently proposed LHC observables that are based on azimuthal-angle
ratios in a kinematical setup that is an extension to the usual one for
Mueller-Navelet jets, after requiring an extra tagged jet in central regions of
rapidity. The corrections tend to be mild which suggests that these observables
are an excellent way to probe the onset of BFKL effects at hadronic colliders.Comment: 6 pages, presented by G. Chachamis at the 25th International Workshop
on Deep Inelastic Scattering and Related Topics, 3-7 April 2017, Birmingham,
U
Probing the BFKL dynamics in inclusive three jet production at the LHC
We propose the study of new observables in LHC inclusive events with three
tagged jets, one in the forward direction, one in the backward direction and
both well-separated in rapidity from the each other (Mueller-Navelet jets),
together with a third jet tagged in central regions of rapidity. Since
non-tagged associated mini-jet multiplicity is allowed, we argue that
projecting the cross sections on azimuthal-angle components can provide several
distinct tests of the BFKL dynamics. Realistic LHC kinematical cuts are
introduced.Comment: 8 pages. Talk given by G. Chachamis at the 5th International
Conference on New Frontiers in Physics (ICNFP2016), 6-14 July 2016,
Kolymbari, Crete, Greec
Evolution of clonal populations approaching a fitness peak
Populations facing novel environments are expected to evolve through the accumulation of adaptive substitutions. The dynamics of adaptation depend on the fitness landscape and possibly on the genetic background on which new mutations arise. Here, we model the dynamics of adaptive evolution at the phenotypic and genotypic levels, focusing on a Fisherian landscape characterized by a single peak. We find that Fisher's geometrical model of adaptation, extended to allow for small random environmental variations, is able to explain several features made recently in experimentally evolved populations. Consistent with data on populations evolving under controlled conditions, the model predicts that mean population fitness increases rapidly when populations face novel environments and then achieves a dynamic plateau, the rate of molecular evolution is remarkably constant over long periods of evolution, mutators are expected to invade and patterns of epistasis vary along the adaptive walk. Negative epistasis is expected in the initial steps of adaptation but not at later steps, a prediction that remains to be tested. Furthermore, populations are expected to exhibit high levels of phenotypic diversity at all times during their evolution. This implies that populations are possibly able to adapt rapidly to novel abiotic environments.CAPES-IGC
Scaling, genetic drift and clonal interference in the extinction pattern of asexual populations
We investigate the dynamics of loss of favorable mutations in an asexual haploid population. In the current work, we consider homogeneous as well as spatially structured population models. We focus our analysis on statistical measurements of the probability distribution of the maximum population size N(sb) achieved by those mutations that have not reached fixation. Our results show a crossover behavior which demonstrates the occurrence of two evolutionary regimes. In the first regime, which takes place for small N(sb) , the probability distribution is described by a power law with characteristic exponent theta(d) =1.8 +/- 0.01. This power law is not influenced by the rate of beneficial mutations. The second regime, which occurs for intermediate to large values of N(sb), has a characteristic exponent theta(c) which increases as the rate of beneficial mutations grows. These results establish where genetic drift and clonal interference become the main underlying mechanism in the extinction of advantageous mutations
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The Influence of Changing Hours of Work on Women’s Life-Satisfaction
This paper asks whether moving to part-time work makes women happy. Previous research on labour supply has assumed that as workers freely choose their optimal working hours on the basis of their innate preferences and the hourly wage rate, outcome reflects preference. This paper tests this assumption by measuring the impact of changes in working-hours on life satisfaction in two countries (the UK and Germany using the German Socio-Economic Panel and the British Household Panel Survey). We find decreases in working-hours bring about positive and significant improvement on well-being for women
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