| 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. |
- Amsler, C., et al.
(författare)
-
Review of particle physics
- 2008
-
Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 667:1-5, s. 1-1
-
Forskningsöversikt (refereegranskat)abstract
- This biennial Review summarizes much of particle physics. Using data from previous editions., plus 2778 new measurements from 645 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors., probability, and statistics. Among the 108 reviews are many that are new or heavily revised including those on CKM quark-mixing matrix, V-ud & V-us, V-cb & V-ub, top quark, muon anomalous magnetic moment, extra dimensions, particle detectors, cosmic background radiation, dark matter, cosmological parameters, and big bang cosmology.
|
|
| 3. |
- Yao, W-M, et al.
(författare)
-
Review of Particle Physics
- 2006
-
Ingår i: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 33:1, s. 1-1
-
Tidskriftsartikel (refereegranskat)
|
|
| 4. |
|
|
| 5. |
- Clark, Andrew G., et al.
(författare)
-
Evolution of genes and genomes on the Drosophila phylogeny
- 2007
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
-
Tidskriftsartikel (refereegranskat)abstract
- Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
|
|
| 6. |
|
|
| 7. |
- Adolph, C, et al.
(författare)
-
Measurement of the eta -> 3 pi(0) Dalitz plot distribution with the WASA detector at COSY
- 2009
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 677:1-2, s. 24-29
-
Tidskriftsartikel (refereegranskat)abstract
- In the first production run of the WASA experiment at COSY, the eta decay into three neutral pions was measured in proton-proton interactions at a proton beam kinetic energy of 1.4 GeV. The Dalitz plot of the three pious was Studied using 1.2 x 10(5) fully reconstructed events. and the quadratic slope parameter alpha was determined to be -0.027 +/- 0.008(stat) +/- 0.005(syst). The result is consistent with previous measurements and further corroborates the importance of pion-pion final state interactions. (C) 2009 Elsevier B.V. All rights reserved.
|
|
| 8. |
- Arimoto, M., et al.
(författare)
-
Performance assessment study of the balloon-borne astronomical soft gamma-ray polarimeter PoGOLite
- 2007
-
Ingår i: Physica. E, Low-Dimensional systems and nanostructures. - : Elsevier BV. - 1386-9477 .- 1873-1759. ; 40:2, s. 438-441
-
Tidskriftsartikel (refereegranskat)abstract
- Measurements of polarization play a crucial role in the understanding of the dominant emission mechanism of astronomical sources. Polarized Gamma-ray Observer-Light version (PoGOLite) is a balloon-borne astronomical soft gamma-ray polarimeter at the 25-80 keV band. The PoGOLite detector consists of a hexagonal close-packed array of 217 Phoswich detector cells (PDCs) and side anti-coincidence shields (SASs) made of BGO crystals surrounding PDCs. Each PDC consists of a slow hollow scintillator, a fast scintillator and a BGO crystal that connects to a photomultiplier tube at the end. To examine the PoGOLite's capability and estimate the performance, we conducted experiments with the PDC using radioisotope 241Am. In addition, we compared this result with performance expected by Monte Carlo simulation with Geant4. As a result, we found that the actual PDC has the capability to detect a 100 m Crab source until 80 keV.
|
|
| 9. |
- Kanai, Y., et al.
(författare)
-
Beam test of a prototype phoswich detector assembly for the PoGOLite astronomical soft gamma-ray polarimeter
- 2007
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 570:1, s. 61-71
-
Tidskriftsartikel (refereegranskat)abstract
- We report about the beam test on a prototype of the balloon-based astronomical soft gamma-ray polarimeter, PoGOLite (Polarized Gamma-ray Observer-Light Version) conducted at KEK Photon Factory, a synchrotron radiation facility in Japan. The synchrotron beam was set at 30, 50, and 70 keV and its polarization was monitored by a calibrated polarimeter. The goal of the experiment was to validate the flight design of the polarimeter. PoGOLite is designed to measure polarization by detecting a Compton scattering and the subsequent photo-absorption in an array of 217 well-type phoswich detector cells (PDCs). The test setup included a first flight model PDC and a front-end electronics to select and reconstruct valid Compton scattering events. The experiment has verified that the flight PDC can detect recoil electrons and select valid Compton scattering events down to 30 keV from background. The measure azimuthal modulations (34.4%, 35.8% and 37.2% at 30, 50, and 70 keV, respectively) agreed within 10% (relative) with the predictions by Geant4 implemented with dependence on the initial and final photon polarizations.
|
|
| 10. |
- Regan, P H, et al.
(författare)
-
Vibrational and rotational sequences in Mo-101 and Ru-103,Ru-4 studied via multinucleon transfer reactions
- 2005
-
Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 36:4, s. 1313-1322
-
Tidskriftsartikel (refereegranskat)abstract
- The near-yrast states of Mo-101(42)59 and Ru-103,4(44)59,60 have been studied following their population via heavy-ion multinucleon transfer reactions between a Xe-136 beam and a thin, self-supporting Mo-100 target. The ground state sequence in Ru-104 can be understood as demonstrating a simple evolution from a quasi-vibrational structure at lower spins to statically deformed, quasi-rotational excitation involving the population of a pair of low-Omega h(11/2) neutron orbitals. The effect of the decoupled h(11/2) orbital on this vibration-to-rotational evolution is demonstrated by an extension of the "E-GOS" prescription to include odd-A nuclei. The experimental results are also compared with self-consistent Total Routhian Surface calculations which also highlight the polarising role of the highly aligned neutron h(11/2) orbital in these nuclei.
|
|
