1,968 research outputs found
Tests of the Standard Model Using Muon Polarization Asymmetries in Kaon Decays
We have examined the physics and the experimental feasibility of studying
various kaon decay processes in which the polarization of a muon in the final
state is measured. Valuable information on CP violation, the quark mixing (CKM)
matrix, and new physics can be obtained from such measurements. We have
considered muon polarization in K_L to mu+ mu- and K to pi mu+ mu- decays.
Although the effects are small, or difficult to measure because of the small
branching ratios involved, these studies could provide clean measurements of
the CKM parameters. The experimental difficulty appears comparable to the
observation of K to pi nu barnu. New sources of physics, involving non-standard
CP violation, could produce effects observable in these measurements. Limits
from new results on the neutron and electron electric dipole moment, and
epsilon-prime over epsilon in neutral kaon decays, do not eliminate certain
models that could contribute to the signal. A detailed examination of muon
polarization out of the decay plane in KMU3 and radiative KMU2 decays also
appears to be of interest. With current kaon beams and detector techniques, it
is possible to measure the T-violating polarization for KMU3 with uncertainties
approaching 0.0001. This level of sensitivity would provide an interesting
probe of new physics.Comment: 24 pages, 3 figures, To be published in the International Journal of
Modern Physics
Analysis of a Large Sample of Neutrino-Induced Muons with the ArgoNeuT Detector
ArgoNeuT, or Argon Neutrino Test, is a 170 liter liquid argon time projection
chamber designed to collect neutrino interactions from the NuMI beam at Fermi
National Accelerator Laboratory. ArgoNeuT operated in the NuMI low-energy beam
line directly upstream of the MINOS Near Detector from September 2009 to
February 2010, during which thousands of neutrino and antineutrino events were
collected. The MINOS Near Detector was used to measure muons downstream of
ArgoNeuT. Though ArgoNeuT is primarily an R&D project, the data collected
provide a unique opportunity to measure neutrino cross sections in the 0.1-10
GeV energy range. Fully reconstructing the muon from these interactions is
imperative for these measurements. This paper focuses on the complete kinematic
reconstruction of neutrino-induced through-going muons tracks. Analysis of this
high statistics sample of minimum ionizing tracks demonstrates the reliability
of the geometric and calorimetric reconstruction in the ArgoNeuT detector
The ArgoNeuT Detector in the NuMI Low-Energy beam line at Fermilab
The ArgoNeuT liquid argon time projection chamber has collected thousands of
neutrino and antineutrino events during an extended run period in the NuMI
beam-line at Fermilab. This paper focuses on the main aspects of the detector
layout and related technical features, including the cryogenic equipment, time
projection chamber, read-out electronics, and off-line data treatment. The
detector commissioning phase, physics run, and first neutrino event displays
are also reported. The characterization of the main working parameters of the
detector during data-taking, the ionization electron drift velocity and
lifetime in liquid argon, as obtained from through-going muon data complete the
present report.Comment: 43 pages, 27 figures, 5 tables - update referenc
The polyAT, intronic IVS11-6 and Lys939Gln XPC polymorphisms are not associated with transitional cell carcinoma of the bladder
Chemical carcinogens from cigarette smoking and occupational exposure are risk factors for bladder transitional cell carcinoma (TCC). The Xeroderma Pigmentosum Group C (XPC) gene is essential for repair of bulky adducts from carcinogens. The Xeroderma Pigmentosum Group C gene polymorphisms may alter DNA repair capacity (DRC), thus giving rise to genetic predisposition to bladder cancer. Recent studies have demonstrated linkage disequilibrium between three polymorphisms in the XPC gene (polyAT, IVS11-6 and Lys939Gln) and these have been shown to influence the DRC, as well as to be associated with bladder cancer risk. We analysed all three XPC polymorphisms in 547 bladder TCC patients and 579 cancer-free controls to investigate the association between these polymorphisms and bladder cancer susceptibility, and we also attempted to assess gene–environmental interactions. We confirmed strong linkage disequilibrium among the polymorphisms (Lewontin's D′>0.99). Using logistic regression adjusting for smoking, occupational and family history, neither the heterozygote nor the homozygote variants of these polymorphisms were associated with increased bladder cancer risk (adjusted odds ratio [95% confidence interval] for heterozygote 0.82 [0.63–1.07], 0.82 [0.63–1.08] and 0.83 [0.63–1.08] for PolyAT, IVS11-6 and Lys939Gln, respectively and homozygote variant, 0.98 [0.68–1.42], 0.99 [0.69–1.43] and 1.01 [0.70–1.46]). Moreover, we did not find any significant interaction between these XPC polymorphisms and environmental exposure to cigarette smoking and occupational carcinogens
Changes in vitamin and mineral supplement use after breast cancer diagnosis in the Pathways Study: a prospective cohort study
BACKGROUND: Vitamin and mineral supplement use after a breast cancer diagnosis is common and controversial. Dosages used and the timing of initiation and/or discontinuation of supplements have not been clearly described. METHODS: We prospectively examined changes in use of 17 vitamin/mineral supplements in the first six months following breast cancer diagnosis among 2,596 members (28% non-white) of Kaiser Permanente Northern California. We used multivariable logistic regression to examine demographic, clinical, and lifestyle predictors of initiation and discontinuation. RESULTS: Most women used vitamin/mineral supplements before (84%) and after (82%) diagnosis, with average doses far in excess of Institute of Medicine reference intakes. Over half (60.2%) reported initiating a vitamin/mineral following diagnosis, 46.3% discontinuing a vitamin/mineral, 65.6% using a vitamin/mineral continuously, and only 7.2% not using any vitamin/mineral supplement before or after diagnosis. The most commonly initiated supplements were calcium (38.2%), vitamin D (32.01%), vitamin B6 (12.3%) and magnesium (11.31%); the most commonly discontinued supplements were multivitamins (17.14%), vitamin C (15.97%) and vitamin E (45.62%). Higher education, higher intake of fruits/vegetables, and receipt of chemotherapy were associated with initiation (p-values <0.05). Younger age and breast-conserving surgery were associated with discontinuation (p-values <0.05). CONCLUSIONS: In this large cohort of ethnically diverse breast cancer patients, high numbers of women used vitamin/mineral supplements in the 6Â months following breast cancer diagnosis, often at high doses and in combination with other supplements. The immediate period after diagnosis is a critical time for clinicians to counsel women on supplement use
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