| 1. |
- Schael, S, et al.
(författare)
-
Precision electroweak measurements on the Z resonance
- 2006
-
Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
-
Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron 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 cross-sections, forward-backward 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 Z-pole, 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 Z-pole measurements, the forward-backward asymmetry in b-quark 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 Z-pole 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.
|
|
| 2. |
- Abbasi, R, et al.
(författare)
-
FIRST NEUTRINO POINT-SOURCE RESULTS FROM THE 22 STRING ICECUBE DETECTOR
- 2009
-
Ingår i: Astrophysical Journal Letters. - 2041-8205. ; 701, s. L47-L51
-
Tidskriftsartikel (refereegranskat)abstract
- We present new results of searches for neutrino point sources in the northern sky, using data recorded in 2007-2008 with 22 strings of the IceCube detector (approximately one-fourth of the planned total) and 275.7 days of live time. The final sample of 5114 neutrino candidate events agrees well with the expected background of atmospheric muon neutrinos and a small component of atmospheric muons. No evidence of a point source is found, with the most significant excess of events in the sky at 2.2 sigma after accounting for all trials. The average upper limit over the northern sky for point sources of muon-neutrinos with E-2 spectrum is E-2 Phi(v mu) < 1.4 x 10(-11) TeV cm(-2) s(-1), in the energy range from 3 TeV to 3 PeV, improving the previous best average upper limit by the AMANDA-II detector by a factor of 2.
|
|
| 3. |
|
|
| 4. |
- Barraza-Villarreal, Albino, et al.
(författare)
-
Air pollution, airway inflammation, and lung function in a cohort study of Mexico City schoolchildren.
- 2008
-
Ingår i: Environmental health perspectives. - : Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 116:6, s. 832-8
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The biological mechanisms involved in inflammatory response to air pollution are not clearly understood. OBJECTIVE: In this study we assessed the association of short-term air pollutant exposure with inflammatory markers and lung function. METHODS: We studied a cohort of 158 asthmatic and 50 nonasthmatic school-age children, followed an average of 22 weeks. We conducted spirometric tests, measurements of fractional exhaled nitric oxide (Fe(NO)), interleukin-8 (IL-8) in nasal lavage, and pH of exhaled breath condensate every 15 days during follow-up. Data were analyzed using linear mixed-effects models. RESULTS: An increase of 17.5 microg/m(3) in the 8-hr moving average of PM(2.5) levels (interquartile range) was associated with a 1.08-ppb increase in Fe(NO) [95% confidence interval (CI), 1.01-1.16] and a 1.07-pg/mL increase in IL-8 (95% CI 0.98-1.19) in asthmatic children and a 1.16 pg/ml increase in IL-8 (95% CI, 1.00-1.36) in nonasthmatic children. The 5-day accumulated average of exposure to particulate matter <2.5 microm in aerodynamic diamter (PM(2.5)) was significantly inversely associated with forced expiratory volume in 1 sec (FEV(1)) (p=0.048) and forced vital capacity (FVC) (p=0.012) in asthmatic children and with FVC (p=0.021) in nonasthmatic children. Fe(NO) and FEV(1) were inversely associated (p=0.005) in asthmatic children. CONCLUSIONS: Exposure to PM(2.5) resulted in acute airway inflammation and decrease in lung function in both asthmatic and nonasthmatic children.
|
|
| 5. |
|
|
| 6. |
- Brunet, Manola, et al.
(författare)
-
Long-term changes in extreme temperatures and precipitation in Spain
- 2007
-
Ingår i: Contributions to Science: The International Journal of the Institute for Catalan Studies (IEC). - 1575-6343. ; 3:3, s. 331-342
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The development of the Spanish daily adjusted temperatureseries (SDATS) and the Spanish daily adjusted precipitation series(SDAPS) datasets in the framework of the European Community(EC)-funded project EMULATE (European and North Atlanticdaily to MULtidecadal climATE variability) enabled theassessment of long-term annual changes of extreme temperatureand precipitation indices over peninsular Spain for the period1901–2005. Within this framework, a set of procedureswas developed to generate long-term (1850–2005) daily adjustedtemperature and precipitation series and to use them toassess changes in climatic extremes. The present report describesdetails of the data employed to analyze the behavior ofSpanish climate extremes and discusses the results of investigationsinto the annual changes in selected indices that occurredduring the 20th century: exceedances of upper and lowerpercentiles of daily maximum (Tmax) and minimum (Tmin)temperatures, cold-spell duration index (CSDI), warm-spell durationindex (WSDI), daily rainfall (R) exceeding the 95th and 99thpercentiles, simple daily intensity index (SDII), and greatest 1–and 5-day total precipitation. Upper and lower temperaturepercentiles increased during the 20th century over mainlandSpain, but changes in daytime extreme temperatures werelarger than the changes in night-time extreme temperatures.This pattern, however, shifted slightly in the recent period ofstrong warming, with more similar rates of change among daytimeand night-time extreme temperatures. Changes in extremeprecipitation indices were not as evident as those in extreme-temperature indices, but there was a tendency towardsheavier precipitation.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Plieva, Fatima, et al.
(författare)
-
Pore structure in supermacroporous polyacrylamide based cryogels
- 2005
-
Ingår i: Soft Matter. - : Royal Society of Chemistry (RSC). - 1744-6848 .- 1744-683X. ; 1:4, s. 303-309
-
Tidskriftsartikel (refereegranskat)abstract
- Pore size and thickness of pore walls in macroporous polyacrylamide gels, so-called cryogels (pAAm-cryogels), were controlled by varying the content of monomers in the initial reaction mixture and the cross-linker used. The thickness of pore walls in pAAm-cryogels increased with increasing concentration of monomers in the initial reaction mixture. Pore volume in the supermacroporous pAAm-cryogels was in the range of 70-93% and decreased with increasing concentration of monomers in the reaction feed. The porous structure of the pAAm-cryogels was visualized using environmental scanning electron microscopy (ESEM) that allowed monitoring of the dehydration process in pAAm-cryogels. The accessibility of ligands covalently coupled to the polymer backbone for low molecular weight target, Cu(II) ions, and high molecular weight target, the protein lysozyme, was assessed for pAAm-cryogels produced from feeds with different monomer concentration. The amount of bound Cu(II) ions increased linearly with increasing monomer concentration in the reaction feed, suggesting that all ligands are equally accessible for small targets. On the contrary, lysozyme binding demonstrated a clear maximum at monomer concentration about 18% suggesting that only ligrands present at the surface of pore walls are accessible for high molecular weight targets.
|
|
