593 research outputs found
Measurement of helium-3 and deuterium stopping power ratio for negative muons
The measurement method and results measuring of the stopping power ratio of
helium-3 and deuterium atoms for muons slowed down in the D/He mixture are
presented. Measurements were performed at four values of pure He gas target
densities, (normalized to the
liquid hydrogen density) and at a density 0.0585 of the D/He mixture. The
experiment was carried out at PSI muon beam E4 with the momentum P MeV/c. The measured value of the mean stopping ratio is
. This value can also be interpreted as the value of mean reduced
ratio of probabilities for muon capture by helium-3 and deuterium atoms.Comment: 7 pages, 6 figure
Compilation and analysis of charge asymmetry measurements from electron and positron scattering on nucleon and nuclei
World data on the lepton-charge asymmetry in the elastic and inelastic lepton
scattering off the proton and nuclei are compiled and discussed. After
reviewing the published results, we compare the elastic data to a model
calculation of the two-photon exchange mechanism. We show that the existing
data do not provide any evidence for the two-photon contribution. At
significance level 0.05 the data allow to exclude the two-photon exchange as an
explanation for the difference between Rosenbluth and polarization measurements
of proton electromagnetic form factors.Comment: 20 pages, 7 figures 2 table
Monte Carlo Fitting Of Data From Muon Catalyzed Fusion Experiments In Solid Hydrogen
Applying the classical chi-square fitting procedure for multiparameter systems is in somecases extremely difficult due to the lack of an analytical expression for the theoretical functionsdescribing the system. This paper presents an analysis procedure for experimental datausing theoretical functions generated by Monte Carlo method, each corresponding to definitevalues of the minimization parameters. It was applied for the E742 experiment (TRIUMF,Vancouver, Canada) data analysis with the aim to analyze data from Muon Catalyzed Fusionexperiments (extraction muonic atom scattering parameters and parameters of pd fusion inpdμ molecule)
Method of Monte Carlo grid for data analysis
This paper presents an analysis procedure for experimental data using
theoretical functions generated by Monte Carlo. Applying the classical
chi-square fitting procedure for some multiparameter systems is extremely
difficult due to a lack of an analytical expression for the theoretical
functions describing the system. The proposed algorithm is based on the least
square method using a grid of Monte Carlo generated functions each
corresponding to definite values of the minimization parameters. It is used for
the E742 experiment (TRIUMF, Vancouver, Canada) data analysis with the aim to
extract muonic atom scattering parameters on solid hydrogen.Comment: 16 pages, 10 figures, submitted to NI
Methods of studying the composition of the low-energy ion beams and the surface of deuterated-metal targets
To study the reactions between the light nuclei (dd, pd, d{3}He, d{4}He) with ultralow collision energies, there is a need to obtain the high-precision experimental results on the purity of the target surface saturated with the hydrogen isotopes (protium, deuterium) and on the number and composition of the accelerated particles falling on the target. To solve this problem, a method has been developed and tested for operational testing the quality of the vacuum system and the cleaning of the metal target surface saturated with deuterium. The paper also presents the measurement results for the true flow of the accelerated ions and neutrals of hydrogen (deuterium), using a multigrid electrostatic energy analyzer. The values of the ion and neutral components of the accelerated particle flow were received for the Hall ion source. The values of the secondary electron emission coefficients were determined for a number of the metal targets (Cu, Ti, Ta, Zr) in the range of the accelerated ion energies of 3-12 keV
Muon capture by 3He nuclei followed by proton and deuteron production
The paper describes an experiment aimed at studying muon capture by
nuclei in pure and mixtures at various densities. Energy distributions of
protons and deuterons produced via and are measured for the
energy intervals MeV and MeV, respectively. Muon capture
rates, and are obtained using two different analysis methods. The
least--squares methods gives , . The Bayes theorem
gives ,
. The experimental
differential capture rates, and , are compared with theoretical
calculations performed using the plane--wave impulse approximation (PWIA) with
the realistic NN interaction Bonn B potential. Extrapolation to the full energy
range yields total proton and deuteron capture rates in good agreement with
former results.Comment: 17 pages, 13 figures, accepted for publication in PR
Muon Capture on the Proton and Deuteron
By measuring the lifetime of the negative muon in pure protium (hydrogen-1),
the MuCap experiment determines the rate of muon capture on the proton, from
which the proton's pseudoscalar coupling g_p may be inferred. A precision of
15% for g_p has been published; this is a step along the way to a goal of 7%.
This coupling can be calculated precisely from heavy baryon chiral perturbation
theory and therefore permits a test of QCD's chiral symmetry. Meanwhile, the
MuSun experiment is in its final design stage; it will measure the rate of muon
capture on the deuteron using a similar technique. This process can be related
through pionless effective field theory and chiral perturbation theory to other
two-nucleon reactions of astrophysical interest, including proton-proton fusion
and deuteron breakup.Comment: Submitted to the proceedings of the 2007 Advanced Studies Institute
on Symmetries and Spin (SPIN-Praha-2007
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