The MuCap experiment at the Paul Scherrer Institute has measured the rate Λ(S) of muon capture from the singlet state of the muonic hydrogen atom to a precision of 1%. A muon beam was stopped in a ...time projection chamber filled with 10-bar, ultrapure hydrogen gas. Cylindrical wire chambers and a segmented scintillator barrel detected electrons from muon decay. Λ(S) is determined from the difference between the μ(-) disappearance rate in hydrogen and the free muon decay rate. The result is based on the analysis of 1.2 × 10(10) μ(-) decays, from which we extract the capture rate Λ(S) = (714.9 ± 5.4(stat) ± 5.1(syst)) s(-1) and derive the proton's pseudoscalar coupling g(P)(q(0)(2) = -0.88 m(μ)(2)) = 8.06 ± 0.55.
Atomic-force microscopy methods were used to study specimens of cathodes of multiwire proportional chambers subjected to a long-term exposure to a β-source
90
Sr in the course of laboratory longevity ...tests. The changes in the surface morphology of the copper foil at the detector cathode that have occurred as a result of action of an electron beam have been described. The quantitative estimate and analysis of the evolution of radiation defects depending on the irradiation dose are presented. The similarity of the radiation-induced defects in the laboratory prototypes and in the full-scale proportional chambers after their use for 10 years at the Large Hadron Collider is demonstrated.
The rate of nuclear muon capture by the proton has been measured using a new technique based on a time projection chamber operating in ultraclean, deuterium-depleted hydrogen gas, which is key to ...avoiding uncertainties from muonic molecule formation. The capture rate from the hyperfine singlet ground state of the microp atom was obtained from the difference between the micro(-) disappearance rate in hydrogen and the world average for the micro(+) decay rate, yielding Lambda(S)=725.0+/-17.4 s(-1), from which the induced pseudoscalar coupling of the nucleon, g(P)(q(2)=-0.88m(2)(micro))=7.3+/-1.1, is extracted.
The mechanism of occurrence of spontaneous self-sustained currents in a multiwire proportional chamber from the experiment at the Large Hadron Collider has been considered. Atomic force microscopy, ...Rutherford backscattering, and Raman spectroscopy on the copper foil of the chamber cathode revealed the formation of nanocarbon structures and their fluorinated compounds, which are well known as low-threshold sources of field emission of electrons.
The relevance of studying such problems as gastroesophageal reflux disease (GERD) and obesity is caused by their high prevalence in the developed countries of the world. Epidemiological data indicate ...that obesity is a significant risk factor for developing GERD due to increased intra-abdominal pressure and gastroesophageal gradient, slowing of gastric evacuation and formation of hiatal hernia. Abdominal obesity increases the likelihood of complications of GERD: erosive esophagitis, Barrett's esophagus and adenocarcinoma. This fact is connected with humoral influences: increased production of pro-inflammatory cytokines and leptin, and decreased secretion of adiponectin. Treatment of comorbid patients requires higher dosages and longer courses of antisecretory medicines, and an additional prescription of ursodeoxycholic acid.
The MuCap experiment at the Paul Scherrer Institute has measured the rate Λ{sub S} of muon capture from the singlet state of the muonic hydrogen atom to a precision of 1%. A muon beam was stopped in ...a time projection chamber filled with 10-bar, ultrapure hydrogen gas. Cylindrical wire chambers and a segmented scintillator barrel detected electrons from muon decay. Λ{sub S} is determined from the difference between the μ{sup -} disappearance rate in hydrogen and the free muon decay rate. The result is based on the analysis of 1.2×10{sup 10} μ{sup -} decays, from which we extract the capture rate Λ{sub S} =(714.9±5.4{sub stat} ±5.1{sub syst} )s{sup -1} and derive the proton’s pseudoscalar coupling g{sub P} (q{sup 2}{sub 0} =-0.88m{sup 2}{sub μ} )=8.06±0.55 .
A comprehensive study is performed of the cathode of a multiwire proportional chamber subjected to prolonged irradiation in an experiment at the LHC. The structural-phase state of the copper foil on ...the cathode is analyzed via nuclear scanning microscopy, atomic scanning microscopy, Raman spectroscopy, and X-ray phase analysis. Nanostructural formations of carbon are found in the zone of spontaneous electron emission on the electrode.
The rate of nuclear muon capture by the proton has been measured using a new technique based on a time projection chamber operating in ultraclean, deuterium-depleted hydrogen gas, which is key to ...avoiding uncertainties from muonic molecule formation. The capture rate from the hyperfine singlet ground state of the {mu}p atom was obtained from the difference between the {mu}{sup -} disappearance rate in hydrogen and the world average for the {mu}{sup +} decay rate, yielding {lambda}{sub S}=725.0{+-}17.4 s{sup -1}, from which the induced pseudoscalar coupling of the nucleon, g{sub P}(q{sup 2}=-0.88m{sub {mu}}{sup 2})=7.3{+-}1.1, is extracted.
Muon catalyzed
dd
fusion in D
2
and HD gases in the temperature range from 28 to 350 K was investigated in a series of experiments based on a time-projection ionization chamber operating with pure ...hydrogen. All main observables in this reaction chain were measured with high absolute precision including the resonant and non-resonant
dd
μ formation rates, the rate for hyperfine transitions in
d
μ atoms, the branching ratio of the two charge symmetric fusion channels
3
He +
n
and
t
+
p
and the muon sticking probability. The report presents the final analysis of the data together with a comprehensive comparison with calculations based on recent μCF theories. The energy of the loosely bound
dd
μ state with quantum numbers
J
= 1,
ν
= 1, which is central to the mechanism of resonant molecule formation, is extracted with precision ɛ
11
(fit) = −1.9651(7) eV. in impressive agreement with the latest theoretical results ɛ
11
(theory) = −1.9646 eV.
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