Encontrados 10 documentos, a visualizar página 1 de 1
Planar LAAPDs: temperature dependence, performance, and application in low-ener...
Ludhova, L.; Amaro, F. D.; Antognini, A.; Biraben, F.; Cardoso, J. M. R.; Conde, C. A. N.; Covita, D. S.; Dax, A.; Dhawan, S.; Fernandes, L. M. P.An experiment measuring the 2S Lamb shift in muonic hydrogen ([mu]-p) was performed at the Paul Scherrer Institute, Switzerland. It required small and compact detectors for 1.9 keV X-rays (2P-1S transition) with an energy resolution around 25% at 2 keV, a time resolution better than 100 ns, a large solid angle coverage, and insensitivity to a 5 T magnetic field. We chose Large Area Avalanche Photodiodes (LAAPDs...
Application of large-area avalanche photodiodes to X-ray spectrometry of muonic...
Fernandes, L. M. P.; Antognini, A.; Boucher, M.; Conde, C. A. N.; Huot, O.; Knowles, P. E.; Kottmann, F.; Ludhova, L.; Mulhauser, F.; Pohl, R.Large-area avalanche photodiodes have been investigated as 1.9-keV X-ray detectors for the muonic hydrogen Lamb-shift experiment. We report experimental tests carried out for evaluation of the avalanche photodiode capabilities for X-ray detection in the intense radiation and low counting rate environment of experiments with muonic atoms. Several muonic atoms were used and it was shown that the electronic backgr...
Large area APDs for low energy X-ray detection in intense magnetic fields
Boucher, M.; Huot, O.; Knowles, P. E.; Ludhova, L.; Mulhauser, F.; Schaller, L. A.; Conde, C. A. N.; Santos, J. M. F. dos; Fernandes, L. M. P.An experiment to measure the energy difference between the 2S-2P atomic levels (Lamb shift) in muonic hydrogen is being prepared at PSI. Since the energy levels of muonic hydrogen are a factor of 186 more energetic than those of hydrogen, according to the ratio of reduced masses, the transitions lie in the soft X-ray region. The experiment needs long-lived muonic hydrogen in the 2S state. This is achieved by st...
Behaviour of large-area avalanche photodiodes under intense magnetic fields for...
Fernandes, L. M. P.; Antognini, A.; Boucher, M.; Conde, C. A. N.; Huot, O.; Knowles, P.; Kottmann, F.; Ludhova, L.; Mulhauser, F.; Pohl, R.The behaviour of large-area avalanche photodiodes for X-rays, visible and vacuum-ultra-violet (VUV) light detection in magnetic fields up to 5 T is described. For X-rays and visible light detection, the photodiode pulse amplitude and energy resolution were unaffected from 0 to 5 T, demonstrating the insensitivity of this type of detector to strong magnetic fields. For VUV light detection, however, the photodiod...
Physics at CPLEAR
Angelopoulos, A.; Apostolakis, A.; Aslanides, E.; Backenstoss, G.; Bargassa, P.; Bee, C. P.; Behnke, O.; Benelli, A.; Bertin, V.; Blanc, F.; Bloch, P.LEAR offered unique opportunities to study the symmetries which exist between matter and antimatter. At variance with other approaches at this facility, CPLEAR was an experiment devoted to the study of , and symmetries in the neutral-kaon system. A variety of measurements allowed us to determine with high precision the parameters which describe the time evolution of the neutral kaons and their antiparticles, in...
Measurement of the energy dependence of the form factor f+ in K0e3 decay
Apostolakis, A.; Aslanides, E.; Backenstoss, G.; Bargassa, P.; Behnke, O.; Benelli, A.; Bertin, V.; Blanc, F.; Bloch, P.; Carlson, P.; Carroll, M.Neutral-kaon decays to [pi]e[nu] were analysed to determine the q2 dependence of the K0e3 electroweak form factor f+. Based on 365 612 events, this form factor was found to have a linear dependence on q2 with a slope [lambda]+=0.0245±0.0012stat±0.0022syst. ; http://www.sciencedirect.com/science/article/B6TVN-414F7YB-Y/1/f9d5dd66c27d4f9264d1cec6fac93c68
Experiment to measure the Lamb shift in muonic hydrogen
Pohl, R.; Biraben, F.; Conde, C. A. N.; Gay, C. Donche; Hänsch, T. W.; Hartmann, F. J.; Hauser, P.; Hughes, V. W.; Huot, O.; Indelicato, P.; Knowles, P.Abstract The contribution of the root mean square (RMS) proton charge radius to the Lamb shift (2S–2P energy difference) in muonic hydrogen (µp) amounts to 2%. Apart from the uncertainty on this charge radius, theory predicts the Lamb shift with a precision on the ppm level. We are going to measure ?E (2 S1/2(F=1)–2 P3/2(F=2)) in a laser resonance experiment to a precision of 30 ppm (i.e., 10% of the natural l...
Tests of the Equivalence Principle with neutral kaons
Apostolakis, A.; Aslanides, E.; Backenstoss, G.; Bargassa, P.; Behnke, O.; Benelli, A.; Bertin, V.; Blanc, F.; Bloch, P.; Carlson, P.; Carroll, M.We test the Principle of Equivalence for particles and antiparticles, using CPLEAR data on tagged K0 and decays into [pi]+[pi]-. For the first time, we search for possible annual, monthly and diurnal modulations of the observables [eta]+- and [phi]+-, that could be correlated with variations in astrophysical potentials. Within the accuracy of CPLEAR, the measured values of [eta]+- and [phi]+- are found not to b...
First direct observation of time-reversal non-invariance in the neutral-kaon sy...
Angelopoulos, A.; Apostolakis, A.; Aslanides, E.; Backenstoss, G.; Bargassa, P.; Behnke, O.; Benelli, A.; Bertin, V.; Blanc, F.; Bloch, P.; Carlson, P.We report on the first observation of time-reversal symmetry violation through a comparison of the probabilities of transforming into K0 and K0 into as a function of the neutral-kaon eigentime t. The comparison is based on the analysis of the neutral-kaon semileptonic decays recorded in the CPLEAR experiment. There, the strangeness of the neutral kaon at time t=0 was tagged by the kaon charge in the reaction at...
An EPR experiment testing the non-separability of the wave function
Apostolakis, A.; Aslanides, E.; Backenstoss, G.; Bargassa, P.; Behnke, O.; Benelli, A.; Bertin, V.; Blanc, F.; Bloch, P.; Carlson, P.; Carroll, M.The EPR-type strangeness correlation in the K0 system produced in the reaction at rest has been tested using the CPLEAR detector. The strangeness was tagged via strong interaction with absorbers away from the creation point. The results are consistent with the QM non-separability of the wave function and exclude a spontaneous wave-function factorisation at creation (CL >99.99%). ; http://www.sciencedirect.co...
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