1,082 research outputs found
RooHammerModel: interfacing the HAMMER software tool with the HistFactory package
Recent -physics results have sparkled great interest in the search for
beyond-the-Standard-Model (BSM) physics in transitions.
The need to analyse in a consistent manner big datasets for these searches,
using high-statistics Monte-Carlo (MC) samples, led to the development of
HAMMER, a software tool which enables to perform a fast morphing of MC-derived
templates to include BSM effects and/or alternative parameterisations of
long-distance effects, avoiding the need to re-generate simulated samples. This
note describes the development of RooHammerModel, an interface between this
tool and the commonly-used data-fitting framework HistFactory. The code is
written in C++ and admits an alternative usage in standalone RooFit analyses.
In this document, the structure and functionality of the user interface are
explained. Information of a public repository where it can be accessed is
provided, as well as validation and performance studies of the interface. The
methods developed in the construction of RooHammerModel can provide specific
information for alternative future attempts to interface HAMMER with other
data-fitting frameworks
Unlocking Andean sigmodontine diversity: five new species of Chilomys (Rodentia: Cricetidae) from the montane forests of Ecuador
The Andean cloud forests of Ecuador are home to several endemic mammals. Members of the Thomasomyini rodents are well represented in the Andes, with Thomasomys being the largest genus (47 species) of the subfamily Sigmodontinae. Within this tribe, however, there are genera that have escaped a taxonomic revision, and Chilomys Thomas, 1897, constitutes a paradigmatic example of these âforgottenâ Andean cricetids. Described more than a century ago, current knowledge of this externally unmistakable montane rodent is very limited, and doubts persist as to whether or not it is monotypic. After several years of field efforts in Ecuador, a considerable quantity of specimens of Chilomys were collected from various localities representing both Andean chains. Based on an extensive genetic survey of the obtained material, we can demonstrate that what is currently treated as C. instans in Ecuador is a complex comprising at least five new species which are described in this paper. In addition, based on these noteworthy new evidence, we amend the generic diagnosis in detail, adding several key craniodental traits such as incisor procumbency and microdonty. These results indicate that Chilomys probably has a hidden additional diversity in large parts of the Colombian and Peruvian territories, inviting a necessary revision of the entire genus.Fil: Brito, Jorge. Instituto Nacional de Biodiversidad; EcuadorFil: Tinoco, NicolĂĄs. Pontificia Universidad CatĂłlica del Ecuador; EcuadorFil: Pinto, C. Miguel. Observatorio de Biodiversidad Ambiente y Salud; EcuadorFil: GarcĂa, RubĂ. Instituto Nacional de Biodiversidad; EcuadorFil: Koch, Claudia. Leibniz Institute for the Analysis of Biodiversity Chang; AlemaniaFil: Fernandez, Vincent. Natural History Museum; Reino UnidoFil: Burneo, Santiago. Pontificia Universidad CatĂłlica del Ecuador; EcuadorFil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Centro Nacional PatagĂłnico. Instituto de Diversidad y EvoluciĂłn Austral; Argentin
Central exclusive production of J/Ï and Ï(2S) mesons in pp collisions at âs=13 TeV
Measurements are reported of the central exclusive production of J/Ï and Ï(2S) mesons in pp collisions at a centre-of-mass energy of 13 TeV. Backgrounds are significantly reduced compared to previous measurements made at lower energies through the use of new forward shower counters. The products of the cross-sections and the branching fractions for the decays to dimuons, where both muons are within the pseudorapidity range 2.0 < η < 4.5, are measured to be
ÏJ/ÏâÎŒ+ÎŒâ=435±18±11±17 pbÏÏ(2S)âÎŒ+ÎŒâ=11.1±1.1±0.3±0.4 pb.
The first uncertainties are statistical, the second are systematic, and the third are due to the luminosity determination. The cross-sections are also measured differentially for meson rapidities between 2.0 and 4.5. Good agreement is observed with theoretical predictions. Photoproduction cross-sections are derived and compared to previous experiments, and a deviation from a pure power-law extrapolation of lower energy data is observed.S
A randomized study of nutritional supplementation in patients with unilateral wet age-related macular degeneration
The purpose of this study is evaluate the efficacy and safety of medicinal products con-taining the original Age-Related Eye Disease group (AREDS) formulation at doses approved in Europe (EU, control group; n = 59) with a product that adds DHA, lutein, zeaxanthin, resveratrol and hydroxytyrosol to the formula (intervention group; n = 50). This was a multicenter, random-ized, observer-blinded trial conducted in patients aged 50 years or older diagnosed with unilateral exudative Age related Macular Degeneration AMD. At month 12, the intervention did not have a significant differential effect on visual acuity compared with the control group, with an estimated treatment difference in Early Treatment Diabetic Retinopathy Study (ETDRS) of -1.63 (95% CI -0.83 to 4.09; p = 0.192). The intervention exhibited a significant and, in most cases, relevant effect in terms of a reduction in some inflammatory cytokines and a greater improvement in the fatty acid profile and serum lutein and zeaxantin concentration. In patients with unilateral wet AMD, the addition of lutein, zeaxanthin, resveratrol, hydroxytyrosol and DHA to the AREDS EU recommended doses in the short-term did not have a differential effect on visual acuity compared to a standard AREDS EU formula but, in addition to improving the fatty acid profile and increasing carotenoid serum levels, may provide a beneficial effect in improving the proinflammatory and proangiogenic profile of patients with AMD. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Measurement of forward J/Ï production cross-sections in pp collisions at âs=13 TeV
The production of J/Ï mesons in proton-proton collisions at a centre-of-mass energy of âs=13 TeV is studied with the LHCb detector. Cross-section measurements are performed as a function of the transverse momentum p T and the rapidity y of the J/Ï meson in the region p T < 14 GeV/c and 2.0 < y < 4.5, for both prompt J/Ï mesons and J/Ï mesons from b-hadron decays. The production cross-sections integrated over the kinematic coverage are 15.30 ± 0.03 ± 0.86 ÎŒb for prompt J/Ï and 2.34 ± 0.01 ± 0.13 ÎŒb for J/Ï from b-hadron decays, assuming zero polarization of the J/Ï meson. The first uncertainties are statistical and the second systematic. The cross-section reported for J/Ï mesons from b-hadron decays is used to extrapolate to a total bb cross-section. The ratios of the cross-sections with respect to âs=8 TeV are also determinedS
Measurement of Ï production in pp collisions at âs=13 TeV
The production cross-sections of Ï(1S), Ï(2S) and Ï(3S) mesons in proton-proton collisions at âs=13 TeV are measured with a data sample corresponding to an integrated luminosity of 277 ± 11 pbâ1 recorded by the LHCb experiment in 2015. The Ï mesons are reconstructed in the decay mode Ï â ÎŒ+ÎŒâ. The differential production cross-sections times the dimuon branching fractions are measured as a function of the Ï transverse momentum, pT, and rapidity, y, over the range 0 < pT < 30 GeV/c and 2.0 < y < 4.5. The ratios of the cross-sections with respect to the LHCb measurement at sâ=8 TeV are also determined. The measurements are compared with theoretical predictions based on NRQCD.S
Development of a silicon bulk radiation damage model for Sentaurus TCAD
This article presents a new bulk radiation damage model for p -type silicon for use in Synopsys Sentaurus TCAD. The model is shown to provide agreement between experiment and simulation for the voltage dependence of the leakage current and the charge collection efficiency, for fluences up to 8Ă10151MeVneqâcm2
Observation of two new baryon resonances
Two structures are observed close to the kinematic threshold in the mass spectrum in a sample of proton-proton collision data, corresponding
to an integrated luminosity of 3.0 fb recorded by the LHCb experiment.
In the quark model, two baryonic resonances with quark content are
expected in this mass region: the spin-parity and
states, denoted and .
Interpreting the structures as these resonances, we measure the mass
differences and the width of the heavier state to be
MeV,
MeV,
MeV, where the first and second
uncertainties are statistical and systematic, respectively. The width of the
lighter state is consistent with zero, and we place an upper limit of
MeV at 95% confidence level. Relative
production rates of these states are also reported.Comment: 17 pages, 2 figure
Study of and decays and determination of the CKM angle
We report a study of the suppressed and favored
decays, where the neutral meson is detected
through its decays to the and CP-even and
final states. The measurement is carried out using a proton-proton
collision data sample collected by the LHCb experiment, corresponding to an
integrated luminosity of 3.0~fb. We observe the first significant
signals in the CP-even final states of the meson for both the suppressed
and favored modes, as well as
in the doubly Cabibbo-suppressed final state of the decay. Evidence for the ADS suppressed decay , with , is also presented. From the observed
yields in the , and their
charge conjugate decay modes, we measure the value of the weak phase to be
. This is one of the most precise
single-measurement determinations of to date.Comment: 22 pages, 9 figures; All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-020.htm
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