1. 
 Glasbey, JC, et al.
(författare)

 2021

swepub:Mat__t


2. 
 Schael, S, et al.
(författare)

Precision electroweak measurements on the Z resonance
 2006

Ingår i: Physics Reports.  : Elsevier BV.  03701573 . 18736270. ; 427:56, s. 257454

Forskningsöversikt (refereegranskat)abstract
 We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electronpositron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include crosssections, forwardbackward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/ 0.0021 GeV, Gamma(Z) = 2.4952 +/ 0.0023 GeV, rho(l) = 1.0050 +/ 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/ 0.00016. The number of light neutrino species is determined to be 2.9840 +/ 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Zpole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Zpole measurements, the forwardbackward asymmetry in bquark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Zpole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/ 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.


3. 
 Schael, S., et al.
(författare)

Electroweak measurements in electron positron collisions at Wbosonpair energies at LEP
 2013

Ingår i: Physics Reports.  : Elsevier BV.  03701573 . 18736270. ; 532:4, s. 119244

Forskningsöversikt (refereegranskat)abstract
 Electroweak measurements performed with data taken at the electron positron collider LEP at CERN from 1995 to 2000 are reported. The combined data set considered in this report corresponds to a total luminosity of about 3 fb(1) collected by the four LEP experiments ALEPH, DELPHI, 13 and OPAL, at centreofmass energies ranging from 130 GeV to 209 GeV. Combining the published results of the four LEP experiments, the measurements include total and differential crosssections in photonpair, fermionpair and fourfermion production, the latter resulting from both doubleresonant WW and ZZ production as well as singly resonant production. Total and differential crosssections are measured precisely, providing a stringent test of the Standard Model at centreofmass energies never explored before in electron positron collisions. Finalstate interaction effects in fourfermion production, such as those arising from colour reconnection and Bose Einstein correlations between the two W decay systems arising in WW production, are searched for and upper limits on the strength of possible effects are obtained. The data are used to determine fundamental properties of the W boson and the electroweak theory. Among others, the mass and width of the W boson, m(w) and Gamma(w), the branching fraction of W decays to hadrons, B(W > had), and the trilinear gaugeboson selfcouplings g(1)(Z), Kgamma and lambda(gamma), are determined to be: m(w) = 80.376 +/ 0.033 GeV Gamma(w) = 2.195 +/ 0.083 GeV B(W > had) = 67.41 +/ 0.27% g(1)(Z) = 0.984(0.020)(+0.018) Kgamma  0.982 +/ 0.042 lambda(gamma) = 0.022 +/ 0.019. (C) 2013 Elsevier B.V. All rights reserved.


4. 


5. 
 Mishra, A, et al.
(författare)

Diminishing benefits of urban living for children and adolescents' growth and development
 2023

Ingår i: Nature.  : Springer Science and Business Media LLC.  14764687 . 00280836. ; 615:7954, s. 874883

Tidskriftsartikel (refereegranskat)abstract
 Optimal growth and development in childhood and adolescence is crucial for lifelong health and wellbeing1–6. Here we used data from 2,325 populationbased studies, with measurements of height and weight from 71 million participants, to report the height and bodymass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few highincome countries. By 2020, the urban height advantage became smaller in most countries, and in many highincome western countries it reversed into a small urbanbased disadvantage. The exception was for boys in most countries in subSaharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the agestandardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, subSaharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twentyfirst century, whereas in much of subSaharan Africa they have amplified.


6. 


7. 
 Ade, P. A. R., et al.
(författare)

Planck 2015 results XIV. Dark energy and modified gravity
 2016

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 594

Tidskriftsartikel (refereegranskat)abstract
 We study the implications of Planck data for models of dark energy (DE) and modified gravity (MG) beyond the standard cosmological constant scenario. We start with cases where the DE only directly affects the background evolution, considering Taylor expansions of the equation of state w(a), as well as principal component analysis and parameterizations related to the potential of a minimally coupled DE scalar field. When estimating the density of DE at early times, we significantly improve present constraints and find that it has to be below similar to 2% (at 95% confidence) of the critical density, even when forced to play a role for z < 50 only. We then move to general parameterizations of the DE or MG perturbations that encompass both effective field theories and the phenomenology of gravitational potentials in MG models. Lastly, we test a range of specific models, such as kessence, f(R) theories, and coupled DE. In addition to the latest Planck data, for our main analyses, we use background constraints from baryonic acoustic oscillations, typeIa supernovae, and local measurements of the Hubble constant. We further show the impact of measurements of the cosmological perturbations, such as redshiftspace distortions and weak gravitational lensing. These additional probes are important tools for testing MG models and for breaking degeneracies that are still present in the combination of Planck and background data sets. All results that include only background parameterizations (expansion of the equation of state, early DE, general potentials in minimallycoupled scalar fields or principal component analysis) are in agreement with ACDM. When testing models that also change perturbations (even when the background is fixed to ACDM), some tensions appear in a few scenarios: the maximum one found is similar to 2 sigma for Planck TT + lowP when parameterizing observables related to the gravitational potentials with a chosen time dependence; the tension increases to, at most, 3 sigma when external data sets are included. It however disappears when including CMB lensing.


8. 
 Ade, P. A. R., et al.
(författare)

Planck 2015 results XVII. Constraints on primordial nonGaussianity
 2016

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 594

Tidskriftsartikel (refereegranskat)abstract
 The Planck full mission cosmic microwave background (CMB) temperature and Emode polarization maps are analysed to obtain constraints on primordial nonGaussianity (NG). Using three classes of optimal bispectrum estimators  separable templatefitting (KSW), binned, and modal we obtain consistent values for the primordial local, equilateral, and orthogonal bispectrum amplitudes, quoting as our final result from temperature alone f(NL)(local) = 2.5 +/ 5.7, f(NL)(equil) = 16 +/ 70, and f(NL)(ortho) = 34 +/ 33 (68% CL, statistical). Combining temperature and polarization data we obtain f(NL)(local) = 0.8 +/ 5.0, f(NL)(equil) = 4 +/ 43, and f(NL)(ortho) = 26 +/ 21 (68% CL, statistical). The results are based on comprehensive crossvalidation of these estimators on Gaussian and nonGaussian simulations, are stable across component separation techniques, pass an extensive suite of tests, and are consistent with estimators based on measuring the Minkowski functionals of the CMB. The effect of timedomain deglitching systematics on the bispectrum is negligible. In spite of these test outcomes we conservatively label the results including polarization data as preliminary, owing to a known mismatch of the noise model in simulations and the data. Beyond estimates of individual shape amplitudes, we present modelindependent, threedimensional reconstructions of the Planck CMB bispectrum and derive constraints on early universe scenarios that generate primordial NG, including general singlefield models of inflation, axion inflation, initial state modifications, models producing parityviolating tensor bispectra, and directionally dependent vector models. We present a wide survey of scaledependent feature and resonance models, accounting for the look elsewhere effect in estimating the statistical significance of features. We also look for isocurvature NG, and find no signal, but we obtain constraints that improve significantly with the inclusion of polarization. The primordial trispectrum amplitude in the local model is constrained to be g(NL)(local) = (9.0 +/ 7.7) x 10(4) (68% CL statistical), and we perform an analysis of trispectrum shapes beyond the local case. The global picture that emerges is one of consistency with the premises of the Lambda CDM cosmology, namely that the structure we observe today was sourced by adiabatic, passive, Gaussian, and primordial seed perturbations.


9. 
 Adam, R., et al.
(författare)

Planck 2015 results X. Diffuse component separation : Foreground maps
 2016

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 594

Tidskriftsartikel (refereegranskat)abstract
 Planck has mapped the microwave sky in temperature over nine frequency bands between 30 and 857 GHz and in polarization over seven frequency bands between 30 and 353 GHz in polarization. In this paper we consider the problem of diffuse astrophysical component separation, and process these maps within a Bayesian framework to derive an internally consistent set of fullsky astrophysical component maps. Component separation dedicated to cosmic microwave background (CMB) reconstruction is described in a companion paper. For the temperature analysis, we combine the Planck observations with the 9yr Wilkinson Microwave Anisotropy Probe (WMAP) sky maps and the Haslam et al. 408 MHz map, to derive a joint model of CMB, synchrotron, freefree, spinning dust, CO, line emission in the 94 and 100 GHz channels, and thermal dust emission. Fullsky maps are provided for each component, with an angular resolution varying between 7: 5 and 1 degrees. Global parameters (monopoles, dipoles, relative calibration, and bandpass errors) are fitted jointly with the sky model, and bestfit values are tabulated. For polarization, the model includes CMB, synchrotron, and thermal dust emission. These models provide excellent fits to the observed data, with rms temperature residuals smaller than 4pK over 93% of the sky for all Planck frequencies up to 353 GHz, and fractional errors smaller than 1% in the remaining 7% of the sky. The main limitations of the temperature model at the lower frequencies are internal degeneracies among the spinning dust, freefree, and synchrotron components; additional observations from external lowfrequency experiments will be essential to break these degeneracies. The main limitations of the temperature model at the higher frequencies are uncertainties in the 545 and 857 GHz calibration and zeropoints. For polarization, the main outstanding issues are instrumental systematics in the 100353 GHz bands on large angular scales in the form of temperaturetopolarization leakage, uncertainties in the analoguetodigital conversion, and corrections for the very long time constant of the bolometer detectors, all of which are expected to improve in the near future.


10. 
 Ade, P. A. R., et al.
(författare)

Planck 2015 results XX. Constraints on inflation
 2016

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 594

Tidskriftsartikel (refereegranskat)abstract
 We present the implications for cosmic inflation of the Planck measurements of the cosmic microwave background (CMB) anisotropies in both temperature and polarization based on the full Planck survey, which includes more than twice the integration time of the nominal survey used for the 2013 release papers. The Planck full mission temperature data and a first release of polarization data on large angular scales measure the spectral index of curvature perturbations to be n(s) = 0.968 +/ 0.006 and tightly constrain its scale dependence to dn(s)/dln k = 0.003 +/ 0.007 when combined with the Planck lensing likelihood. When the Planck highl polarization data are included, the results are consistent and uncertainties are further reduced. The upper bound on the tensortoscalar ratio is r(0).(002) < 0.11 (95% CL). This upper limit is consistent with the Bmode polarization constraint r < 0.12 (95% CL) obtained from a joint analysis of the BICEP2/Keck Array and Planck data. These results imply that V(phi) proportional to phi(2) and natural inflation are now disfavoured compared to models predicting a smaller tensortoscalar ratio, such as R2 inflation. We search for several physically motivated deviations from a simple powerlaw spectrum of curvature perturbations, including those motivated by a reconstruction of the inflaton potential not relying on the slowroll approximation. We find that such models are not preferred, either according to a Bayesian model comparison or according to a frequentist simulationbased analysis. Three independent methods reconstructing the primordial power spectrum consistently recover a featureless and smooth PR (k) over the range of scales 0.008 Mpc(1) less than or similar to k less than or similar to 0.1 Mpc(1). At large scales, each method finds deviations from a power law, connected to a deficit at multipoles l approximate to 2040 in the temperature power spectrum, but at an uncompelling statistical significance owing to the large cosmic variance present at these multipoles. By combining power spectrum and nonGaussianity bounds, we constrain models with generalized Lagrangians, including Galileon models and axion monodromy models. The Planck data are consistent with adiabatic primordial perturbations, and the estimated values for the parameters of the base Lambda cold dark matter (Lambda CDM) model are not significantly altered when more general initial conditions are admitted. In correlated mixed adiabatic and isocurvature models, the 95% CL upper bound for the nonadiabatic contribution to the observed CMB temperature variance is vertical bar alpha(nonadi)vertical bar < 1.9%, 4.0%, and 2.9% for CDM, neutrino density, and neutrino velocity isocurvature modes, respectively. We have tested inflationary models producing an anisotropic modulation of the primordial curvature power spectrum finding that the dipolar modulation in the CMB temperature field induced by a CDM isocurvature perturbation is not preferred at a statistically significant level. We also establish tight constraints on a possible quadrupolar modulation of the curvature perturbation. These results are consistent with the Planck 2013 analysis based on the nominal mission data and further constrain slowroll singlefield inflationary models, as expected from the increased precision of Planck data using the full set of observations.

