3,142 research outputs found
Tests of small proportional tubes with CF4-HRS gas mixtures
We have investigated the operating characteristics and drift times of small proportional tubes (active WIDTH = 3.17 mm) containing mixtures of CF4 and HRS gas (89% Ar, 10% CO2, 1% CH4). As the fraction of CF4 is varied from zero to 100%, maximum drift times decrease from about 32 to 16 ns. The operating voltage increases and the energy resolution worsens significantly with increases in the CF4 component.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27024/1/0000012.pd
Search for heavy sequential neutrinos at PEP and PETRA
The experimental signature of the production of heavy, sequential neutrinos at the PEP and PETRA e+e- colliders is discussed. The model for this discussion assumes that in analogy with quarks the neutrino mass spectrum rises sharply and that massive neutrinos decay via charged currents involving as yet unknown mixing parameters.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24930/1/0000357.pd
Searches for effects of flavor-changing neutral currents
We discuss some possible processes, mainly decays, to search for flavor-changing neutral currents. We examine the theoretical constraints from present data as well as improved sensitivities which might be achieved in future experiments. We focus on the decays K0 --> [mu]e, [Sigma]+ p[mu]e, [tau]--> [mu][mu]e and [mu] --> eee as being particularly interesting for further experimental searches.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23166/1/0000091.pd
Detecting the (Quasi-)Two-Body Decays of Leptons in Short-Baseline Neutrino Oscillation Experiments
Novel detector schemes are proposed for the short-baseline neutrino
experiments of next generation, aimed at exploring the large-
domain of \omutau oscillations in the appearance mode. These schemes emphasize
good spectrometry for charged particles and for electromagnetic showers and
efficient reconstruction of \ypi_gg decays. The basic elements are a sequence
of relatively thin emulsion targets, immersed in magnetic field and
interspersed with electronic trackers, and a fine-grained electromagnetic
calorimeter built of lead glass. These elements act as an integral whole in
reconstructing the electromagnetic showers. This conceptual scheme shows good
performance in identifying the (quasi-)two-body decays by their
characteristic kinematics and in selecting the electronic decays of the .Comment: 34 pages, 8 figure
Alcohol, tobacco and breast cancer: should alcohol be condemned and tobacco acquitted?
British Journal of Cancer (2002) 87, 1195â1196. doi:10.1038/sj.bjc.6600633 www.bjcancer.co
Experimental limits on massive neutrinos from e(+)e(-) annihilations at 29 GeV
This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.37.577.A search was made in 29-GeV e(+)e(-) annihilations for massive neutrinos decaying to e(±)X(â)(Îœ) where X is a muon or meson. A 300-pb(-1) data sample yielded just one candidate event with a mass m(e)X>1.8 GeV. Significant limits are found for new neutrinos with masses from 1.8 to 6.7 GeV and with mixing parameters in the range 3Ă10(-6)<âUâ(2)<1. .A
Male tobacco smoke load and non-lung cancer mortality associations in Massachusetts
<p>Abstract</p> <p>Background</p> <p>Different methods exist to estimate smoking attributable cancer mortality rates (Peto and Ezzati methods, as examples). However, the smoking attributable estimates using these methods cannot be generalized to all population sub-groups. A simpler method has recently been developed that can be adapted and applied to different population sub-groups. This study assessed cumulative tobacco smoke damage (smoke load)/non-lung cancer mortality associations across time from 1979 to 2003 among all Massachusetts males and ages 30â74 years, using this novel methodology.</p> <p>Methods</p> <p>Annual lung cancer death rates were used as smoke load bio-indices, and age-adjusted lung/all other (non-lung) cancer death rates were analyzed with linear regression approach. Non-lung cancer death rates include all cancer deaths excluding lung. Smoking-attributable-fractions (SAFs) for the latest period (year 2003) were estimated as: 1-(estimated unexposed cancer death rate/observed rate).</p> <p>Results</p> <p>Male lung and non-lung cancer death rates have declined steadily since 1992. Lung and non-lung cancer death rates were tightly and steeply associated across years. The slopes of the associations analyzed were 1.69 (95% confidence interval (CI) 1.35â2.04, r = 0.90), and 1.36 (CI 1.14â1.58, r = 0.94) without detected autocorrelation (Durbin-Watson statistic = 1.8). The lung/non-lung cancer death rate associations suggest that all-sites cancer death rate SAFs in year 2003 were 73% (Sensitivity Range [SR] 61â82%) for all ages and 74% (SR 61â82%) for ages 30â74 years.</p> <p>Conclusion</p> <p>The strong lung/non-lung cancer death rate associations suggest that tobacco smoke load may be responsible for most prematurely fatal cancers at both lung and non-lung sites. The present method estimates are greater than the earlier estimates. Therefore, tobacco control may reduce cancer death rates more than previously noted.</p
Role of lepton flavor violating (LFV) muon decay in Seesaw model and LSND
The aim of the work is to study LFV in a newly proposed Seesaw model of
neutrino mass and to see whether it could explain LSND excess. The motivation
of this Seesaw model was that there was no new physics beyond the TeV scale. By
studying \mu \to 3e in this model, it is shown that the upper bound on the
branching ratio requires Higgs mass m_{h} of a new scalar doublet with lepton
number L=-1 needed in the model has to be about 9 TeV. The predicted branching
ratio for \mu \to e\nu_{l}\bar{\nu}_{l} is too small to explain the LSND. PACS:
11.30.Hv, 14.60.PqComment: 05 pages, three figures, the version to appear in PR
- âŠ