We have carried out an (e,e'p) experiment at high momentum transfer and in parallel kinematics to measure the strength of the nuclear spectral function S(k,E) at high nucleon momenta k and large ...removal energies E. This strength is related to the presence of short-range and tensor correlations, and was known hitherto only indirectly and with considerable uncertainty from the lack of strength in the independent-particle region. This experiment locates by direct measurement the correlated strength predicted by theory.
We aimed to evaluate low intensity oral anticoagulation with warfarin and low-dose aspirin in the primary prevention of ischaemic heart disease (IHD).
5499 men aged between 45 years and 69 years at ...high risk of IHD were recruited from 108 practices in the UK that belong to the Medical Research Council's General Practice Research Framework. Initially, warfarin or placebo was randomly allocated to 1427 men; 1013 of these men later moved to a factorial stage of the trial, retaining their warfarin or placebo warfarin allocation and adding randomly allocated active or placebo aspirin. Another 4072 men entered directly into the factorial stage making a total of 5085 men. The four factorial treatment groups were: active warfarin and active aspirin (WA, n=1277), active warfarin and placebo aspirin (W, n=1268), placebo warfarin and active aspirin (A, n=1268), and placebo warfarin and placebo aspirin (P, n=1272). The primary end-point was all IHD defined as the sum of coronary death and fatal and non-fatal myocardial infarction (Ml).
The mean International Normalised Ratio (INR) of those on active warfarin was 1·47. The mean warfarin dose was 4·1 mg a day (range 0·5 mg-12·5 mg). There were 410 IHD events (142 fatal, 268 non-fatal). The main effect of warfarin (ie, WA and W
vs A and P) was a reduction in all IHD of 21% (95% Cl 4–35, p=0·02) chiefly due to a 39% reduction (15–57, p=0·003) in fatal events so that warfarin reduced the death rate from all causes by 17% (1–30, p=0·04). The main effect of aspirin (ie, WA and A
vs W and P) was a reduction in all IHD of 20% (1–35, p=0·04) almost entirely due to a 32% reduction (12–48, p=0·004) in non-fatal events. Absolute reductions in all IHD due to warfarin or aspirin were 2·6 and 2·3 per 1000 person years, respectively. WA reduced all IHD by 34% (11–51, p=0·006) compared with P. WA increased haemorrhagic and fatal strokes. Ruptured aortic or dissecting aneurysms occurred in 15 of those who were or had been on warfarin compared with three of those who had not (p=0·01).
These results add to evidence that aspirin reduces non-fatal IHD. Warfarin reduced all IHD chiefly because of an effect on fatal events. Combined treatment with warfarin and aspirin is more effective in the reduction of IHD than either agent on its own.
We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination of the strength of two-nucleon correlations for several nuclei, ...including light nuclei where clustering effects can, for the first time, be examined. The data also include the kinematic region where three-nucleon correlations are expected to dominate.
We report on a detailed study of longitudinal strength in the nucleon resonance region, presenting new results from inclusive electron-proton cross sections measured at Jefferson Lab Hall C in the ...four-momentum transfer range 0.2
We have measured the nuclear transparency of the A(e,e'pi+) process in 2H, 12C, 27Al, 63Cu, and 197Au targets. These measurements were performed at the Jefferson Laboratory over a four momentum ...transfer squared range Q2=1.1 to 4.7 (GeV/c)2. The nuclear transparency was extracted as the super-ratio of (sigmaA/sigmaH) from data to a model of pion-electroproduction from nuclei without pi-N final-state interactions. The Q2 and atomic number dependence of the nuclear transparency both show deviations from traditional nuclear physics expectations and are consistent with calculations that include the quantum chromodynamical phenomenon of color transparency.
Design studies for a second generation dilepton spectrometer to be built at the SIS accelerator of GSI Darmstadt are presented. The basic design parameters of this system are specified and the ...different detector components for charged particle tracking and for lepton identification are described. The geometrical acceptance for lepton pairs is given. Results on single track momentum resolution and on lepton pair mass resolution are reported.
We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for x>1, which is sensitive to ...short-range contributions to the nuclear wave function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees with higher energy muon scattering measurements, but is in sharp contrast to neutrino scattering measurements which suggested a dramatic enhancement in the distribution of the "superfast" quarks probed at x>1. The falloff at x>1 is noticeably stronger in 2H and 3He, but nearly identical for all heavier nuclei.
Double-spin asymmetries of semiinclusive cross sections for the production of identified pions and kaons have been measured in deep inelastic scattering of polarized positrons on a polarized ...deuterium target. Five helicity distributions including those for three sea quark flavors were extracted from these data together with reanalyzed previous data for identified pions from a hydrogen target. These distributions are consistent with zero for all three sea flavors. A recently predicted flavor asymmetry in the polarization of the light quark sea appears to be disfavored by the data.
We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for $x>1$, which is sensitive to ...short range contributions to the nuclear wave-function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees with higher energy muon scattering measurements, but is in sharp contrast to neutrino scattering measurements which suggested a dramatic enhancement in the distribution of the `super-fast' quarks probed at x>1. The falloff at x>1 is noticeably stronger in ^2H and ^3He, but nearly identical for all heavier nuclei.
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