1,122 research outputs found
Local Inhomogeneity Effects on Nucleation Process in a High External Bias
Quantum nucleation processes in the presence of local moderate
inhomogeneities are studied theoretically at high biases. The quantum
nucleation rate Gamma is calculated for one-dimensional systems in a form Gamma
= A e^(-B/hbar) by using the `bounce' method. The bias-dependence of the
exponent B is shown to be changed by inhomogeneities. This change is explained
by the reduction of the effective spatial dimension of the system. By studying
the system-size dependence of the prefactor A, the condition for the appearance
of inhomogeneity effects is evaluated. Nucleation rates in thermal activation
regimes are also calculated, and compared with quantum tunneling regimes. For
higher-dimensional systems, it is shown that the local approximation of
inhomogeneity does not hold, and that spatial profiles of inhomogeneity become
important.Comment: 10 pages, 6 figure
No association between green tea and prostate cancer risk in Japanese men: the Ohsaki Cohort Study
In a prospective study of 19â561 Japanese men, green-tea intake was not associated with a lower risk of prostate cancer (110 cases), the multivariate hazard ratio for men drinking â„5 cups compared with <1 cup per day being 0.85 (95% confidence interval 0.50â1.43, trend P=0.81)
Personality traits and cancer survival: a Danish cohort study
We conducted a population-based prospective cohort study in Denmark to investigate associations between the personality traits and cancer survival. Between 1976 and 1977, 1020 residents of the Copenhagen County completed a questionnaire eliciting information on personality traits and various health habits. The personality traits extraversion and neuroticism were measured using the short form of the Eysenck Personality Inventory. Follow-up in the Danish Cancer Registry for 1976â2002 revealed 189 incidents of primary cancer and follow-up for death from the date of the cancer diagnosis until 2005 revealed 82 deaths from all-cause in this group. A Cox proportional-hazards model was used to estimate the hazard ratios (HRs) of death from all-cause according to extraversion and neuroticism adjusting for potential confounding factors. A significant association was found between neuroticism and risk of death (HR, 2.3 (95% CI=1.1â4.7); Linear trend P=0.04) but not between extraversion and risk of death (HR, 0.9 (0.4â1.7); Linear trend P=0.34). Similar results were found when using cancer-related death. Stratification by gender revealed a strong positive association between neuroticism and the risk of death among women (Linear trend P=0.03). This study showed that neuroticism is positively associated with cancer survival. Further research on neuroticism and cancer survival is needed
The K2K SciBar Detector
A new near detector, SciBar, for the K2K long-baseline neutrino oscillation
expe riment was installed to improve the measurement of neutrino energy
spectrum and to study neutrino interactions in the energy region around 1 GeV.
SciBar is a 'fully active' tracking detector with fine segmentation consisting
of plastic scintillator bars. The detector was constructed in summer 2003 and
is taking data since October 2003. The basic design and initial performance is
presented.Comment: 7 pages, 4figures, Contributed to Proceedings of the 10th Vienna
Conference on Instrumentation, Vienna, February 16-21, 200
Search for Electron Neutrino Appearance in a 250 km Long-baseline Experiment
We present a search for electron neutrino appearance from accelerator
produced muon neutrinos in the K2K long baseline neutrino experiment. One
candidate event is found in the data corresponding to an exposure of 4.8*10^19
protons on target. The expected background in the absence of neutrino
oscillations is estimated to be 2.4+-0.6 events and is dominated by
mis-identification of events from neutral current pi^0 production. We exclude
the \nu_\mu to \nu_e oscillations at 90% C.L. for the effective mixing angle in
2-flavor approximation of sin^2(2theta_\mu_e) (~= 1/2 sin^2 2 th_13) > 0.15 at
Delta m^2_\mu_e = 2.8*10^{-3} eV^2, the best fit value of the \nu_\mu
disappearance analysis in K2K. The most stringent limit of sin^2(2theta_\mu_e)
< 0.09 is obtained at Delta m^2_\mu_e = 6*10^{-3} eV^2.Comment: 5 pages with 2 figures embeded in two column revtex4 style. Accepted
to be published in Phys. Rev. Let
Solar neutrino measurements in Super-Kamiokande-I
The details of Super--Kamiokande--I's solar neutrino analysis are given.
Solar neutrino measurement in Super--Kamiokande is a high statistics collection
of B solar neutrinos via neutrino-electron scattering. The analysis method
and results of the 1496 day data sample are presented. The final oscillation
results for the data are also presented.Comment: 32pages, 57figures, submitted to Physical Review
Experimental study of the atmospheric neutrino backgrounds for proton decay to positron and neutral pion searches in water Cherenkov detectors
The atmospheric neutrino background for proton decay to positron and neutral
pion in ring imaging water Cherenkov detectors is studied with an artificial
accelerator neutrino beam for the first time. In total, about 314,000 neutrino
events corresponding to about 10 megaton-years of atmospheric neutrino
interactions were collected by a 1,000 ton water Cherenkov detector (KT). The
KT charged-current single neutral pion production data are well reproduced by
simulation programs of neutrino and secondary hadronic interactions used in the
Super-Kamiokande (SK) proton decay search. The obtained proton to positron and
neutral pion background rate by the KT data for SK from the atmospheric
neutrinos whose energies are below 3 GeV is about two per megaton-year. This
result is also relevant to possible future, megaton-scale water Cherenkov
detectors.Comment: 13 pages, 16 figure
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