| 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. |
|
|
| 3. |
- Aad, G., et al.
(författare)
-
- 2012
-
swepub:Mat__t (refereegranskat)
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
|
|
| 13. |
|
|
| 14. |
|
|
| 15. |
|
|
| 16. |
|
|
| 17. |
- Alcorn, J, et al.
(författare)
-
Basic instrumentation for Hall A at Jefferson Lab
- 2004
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 522:3, s. 294-346
-
Tidskriftsartikel (refereegranskat)abstract
- The instrumentation in Hall A at the Thomas Jefferson National Accelerator Facility was designed to study electro-and photo-induced reactions at very high luminosity and good momentum and angular resolution for at least one of the reaction products. The central components of Hall A are two identical high resolution spectrometers, which allow the vertical drift chambers in the focal plane to provide a momentum resolution of better than 2 x 10(-4). A variety of Cherenkov counters, scintillators and lead-glass calorimeters provide excellent particle identification. The facility has been operated successfully at a luminosity well in excess of 10(38) CM-2 s(-1). The research program is aimed at a variety of subjects, including nucleon structure functions, nucleon form factors and properties of the nuclear medium. (C) 2003 Elsevier B.V. All rights reserved.
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
- Dutta, D, et al.
(författare)
-
Nuclear transparency with the gamma n ->pi(-)p process in He-4
- 2003
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 68:2: 021001
-
Tidskriftsartikel (refereegranskat)abstract
- We have measured the nuclear transparency of the fundamental process gamman-->pi(-)p in He-4. These measurements were performed at Jefferson Lab in the photon energy range of 1.6-4.5 GeV and at theta(cm)(pi)=70degrees and 90degrees. These measurements are the first of their kind in the study of nuclear transparency in photoreactions. They also provide a benchmark test of Glauber calculations based on traditional models of nuclear physics. The transparency results suggest deviations from the traditional nuclear physics picture. The momentum transfer dependence of the measured nuclear transparency is consistent with Glauber calculations that include the quantum chromodynamics phenomenon of color transparency.
|
|
| 24. |
|
|
| 25. |
|
|
| 26. |
|
|
| 27. |
|
|
| 28. |
- Joshi, PK, et al.
(författare)
-
Genome-wide meta-analysis associates HLA-DQA1/DRB1 and LPA and lifestyle factors with human longevity
- 2017
-
Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8:1, s. 910-
-
Tidskriftsartikel (refereegranskat)abstract
- Genomic analysis of longevity offers the potential to illuminate the biology of human aging. Here, using genome-wide association meta-analysis of 606,059 parents’ survival, we discover two regions associated with longevity (HLA-DQA1/DRB1 and LPA). We also validate previous suggestions that APOE, CHRNA3/5, CDKN2A/B, SH2B3 and FOXO3A influence longevity. Next we show that giving up smoking, educational attainment, openness to new experience and high-density lipoprotein (HDL) cholesterol levels are most positively genetically correlated with lifespan while susceptibility to coronary artery disease (CAD), cigarettes smoked per day, lung cancer, insulin resistance and body fat are most negatively correlated. We suggest that the effect of education on lifespan is principally mediated through smoking while the effect of obesity appears to act via CAD. Using instrumental variables, we suggest that an increase of one body mass index unit reduces lifespan by 7 months while 1 year of education adds 11 months to expected lifespan.
|
|
| 29. |
|
|
| 30. |
- Kananen, L, et al.
(författare)
-
Self-rated health in individuals with and without disease is associated with multiple biomarkers representing multiple biological domains
- 2021
-
Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1, s. 6139-
-
Tidskriftsartikel (refereegranskat)abstract
- Self-rated health (SRH) is one of the most frequently used indicators in health and social research. Its robust association with mortality in very different populations implies that it is a comprehensive measure of health status and may even reflect the condition of the human organism beyond clinical diagnoses. Yet the biological basis of SRH is poorly understood. We used data from three independent European population samples (N approx. 15,000) to investigate the associations of SRH with 150 biomolecules in blood or urine (biomarkers). Altogether 57 biomarkers representing different organ systems were associated with SRH. In almost half of the cases the association was independent of disease and physical functioning. Biomarkers weakened but did not remove the association between SRH and mortality. We propose three potential pathways through which biomarkers may be incorporated into an individual’s subjective health assessment, including (1) their role in clinical diseases; (2) their association with health-related lifestyles; and (3) their potential to stimulate physical sensations through interoceptive mechanisms. Our findings indicate that SRH has a solid biological basis and it is a valid but non-specific indicator of the biological condition of the human organism.
|
|
| 31. |
- Levitz, D, et al.
(författare)
-
Determination of optical scattering properties of highly-scattering media in optical coherence tomography images
- 2004
-
Ingår i: Optics Express. - 1094-4087. ; 12:2, s. 249-259
-
Tidskriftsartikel (refereegranskat)abstract
- We developed a new algorithm that fits optical coherence tomography (OCT) signals as a function of depth to a general theoretical OCT model which takes into account multiple scattering effects. With use of this algorithm, it was possible to extract both the scattering coefficient and anisotropy factor from a particular region of interest in an OCT image. The extraction algorithm was evaluated against measurements from an integrating sphere on a set of tissue phantoms and yielded valid results. Finally, a preliminary ex vivo OCT investigation on human aortic specimen indicated that the algorithm may contribute importantly to differentiation between normal and atherosclerotic arteries. We conclude that this algorithm may facilitate tissue characterization by OCT. (C) 2004 Optical Society of America.
|
|
| 32. |
|
|
| 33. |
|
|
| 34. |
|
|
| 35. |
|
|
| 36. |
|
|
| 37. |
- Rvachev, MM, et al.
(författare)
-
Quasielastic He-3(e,e(')p)H-2 reaction at Q(2)=1.5 GeV2 for recoil momenta up to 1 GeV/c
- 2005
-
Ingår i: Physical Review Letters. - 1079-7114. ; 94:19
-
Tidskriftsartikel (refereegranskat)abstract
- We have studied the quasielastic He-3(e,e(')p)H-2 reaction in perpendicular coplanar kinematics, with the energy and the momentum transferred by the electron fixed at 840 MeV and 1502 MeV/c, respectively. The He-3(e,e(')p)H-2 cross section was measured for missing momenta up to 1000 MeV/c, while the A(TL) asymmetry was extracted for missing momenta up to 660 MeV/c. For missing momenta up to 150 MeV/c, the cross section is described by variational calculations using modern He-3 wave functions. For missing momenta from 150 to 750 MeV/c, strong final-state interaction effects are observed. Near 1000 MeV/c, the experimental cross section is more than an order of magnitude larger than predicted by available theories. The A(TL) asymmetry displays characteristic features of broken factorization with a structure that is similar to that generated by available models.
|
|
| 38. |
- Strauch, S, et al.
(författare)
-
Polarization transfer in the He-4((e)over-right-arrow,e '(p)over-right-arrow)H-3 reaction up to Q(2)=2.6 (GeV/c)(2)
- 2003
-
Ingår i: Physical Review Letters. - 1079-7114. ; 91:5: 052301
-
Tidskriftsartikel (refereegranskat)abstract
- We have measured the proton recoil polarization in the He-4((e) over right arrow ,e(')(p) over right arrow)H-4 reaction at Q(2)=0.5, 1.0, 1.6, and 2.6 (GeV/c)(2). The measured ratio of polarization transfer coefficients differs from a fully relativistic calculation, favoring the inclusion of a medium modification of the proton form factors predicted by a quark-meson coupling model. In addition, the measured induced polarizations agree reasonably well with the fully relativistic calculation indicating that the treatment of final-state interactions is under control.
|
|
| 39. |
|
|
| 40. |
|
|
| 41. |
- Thrane, L, et al.
(författare)
-
Extraction of tissue optical properties from optical coherence tomography images for diagnostic purposes
- 2005
-
Ingår i: Saratov Fall Meeting 2004: Optical Technologies in Biophysics and Medicine VI. - : SPIE. - 1996-756X .- 0277-786X. - 0819457523 ; 5771, s. 139-150
-
Konferensbidrag (refereegranskat)abstract
- The concept of optical coherence tomography (OCT) for high-resolution imaging of tissues in vivo is introduced. Analytical and numerical models for describing and understanding the light propagation in samples imaged by OCT systems are presented. An analytical model for calculating the OCT signal based on the extended Huygens-Fresnel principle and valid both for single and multiple scattering regimes is outlined. From this model, an algorithm for extracting tissue optical properties for multi-layered tissues is derived. The algorithm is first verified for various optical properties and geometries using solid phantoms and numerical simulations. The applicability of the algorithm for extraction of tissue optical properties is then demonstrated for vascular tissue samples ex vivo. With the use of data from numerical phantoms, the validity of the OCT extraction algorithm for a two-layer geometry is further supported. It is concluded that by using optical properties extracted from OCT images of human tissues, the clinical utility of OCT imaging can be substantially increased.
|
|
| 42. |
- Ulmer, PE, et al.
(författare)
-
H-2(e,e ' p)n reaction at high recoil momenta
- 2002
-
Ingår i: Physical Review Letters. - 1079-7114. ; 89:6
-
Tidskriftsartikel (refereegranskat)abstract
- The 2H(e,e(')p)n cross section was measured in Hall A of the Thomas Jefferson National Accelerator Facility near the top of the quasielastic peak (x(Bj)=0.964) at a four-momentum transfer squared, Q(2)=0.665 (GeV/c) (2) (omega=0.368 GeV, W=2.057 GeV), and for recoil momenta up to 550 MeV/c. The measured cross section deviates by 1-2sigma from a state-of-the-art calculation at low recoil momenta. At high recoil momenta the cross section is well described by the same calculation; however, in this region, final-state interactions and interaction currents are predicted to be large, and alternative choices of nucleon-nucleon potential and nucleon current operator may result in significant spread in the calculations.
|
|
| 43. |
|
|
| 44. |
- Wijesooriya, K, et al.
(författare)
-
Polarization measurements in neutral pion photoproduction
- 2002
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 66:3
-
Tidskriftsartikel (refereegranskat)abstract
- We present measurements of the recoil proton polarization for the H-1((γ) over right arrow,(p) over right arrow)pi(0) reaction for theta(c.m.)(pi) = 60degrees-135degrees and for photon energies up to 4.1 GeV. These are the first data in this reaction for polarization transfer with circularly polarized photons. Various theoretical models are compared with the results. No evidence for hadron helicity conservation is observed. Models that employ factorization are not favored. It appears from the strong angular dependence of the induced polarization at photon energies of 2.5 and 3.1 GeV that a relatively high spin resonance or background amplitude might exist in this energy region.
|
|
| 45. |
|
|
| 46. |
|
|
| 47. |
- Zhu, LY, et al.
(författare)
-
Cross-section measurement of charged-pion photoproduction from hydrogen and deuterium
- 2003
-
Ingår i: Physical Review Letters. - 1079-7114. ; 91:2: 022003
-
Tidskriftsartikel (refereegranskat)abstract
- We have measured the differential cross section for the gamman-->pi(-)p and gammap-->pi(+)n reactions at theta(c.m.)=90degrees in the photon energy range from 1.1 to 5.5 GeV at Jefferson Lab (JLab). The data at E(gamma)greater than or similar to3.3 GeV exhibit a global scaling behavior for both pi(-) and pi(+) photoproduction, consistent with the constituent counting rule and the existing pi(+) photoproduction data. Possible oscillations around the scaling value are suggested by these new data. The data show enhancement in the scaled cross section at a center-of-mass energy near 2.2 GeV. The cross section ratio of exclusive pi(-) to pi(+) photoproduction at high energy is consistent with the prediction based on one-hard-gluon-exchange diagrams.
|
|
| 48. |
|
|
