Université de Fribourg

Status of the muonic hydrogen Lamb-shift experiment

Nebel, T. ; Amaro, F. D. ; Antognini, A. ; Biraben, F. ; Cardoso, J. M. R. ; Conde, C. A. N. ; Dax, A. ; Dhawan, S. ; Fernandes, L. M. P. ; Giesen, A. ; Hänsch, T. W. ; Indelicato, P. ; Julien, L. ; Knowles, Paul E. ; Kottmann, F. ; Le Bigot, E. ; Liu, Y.-W. ; Lopes, J. A. M. ; Ludhova, Livia ; Monteiro, C. M. B. ; Mulhauser, Françoise ; Nez, F. ; Pohl, R. ; Rabinowitz, P. ; Santos, J. M. F. dos ; Schaller, Lukas A. ; Schuhmann, K. ; Schwob, C. ; Taqqu, D. ; Veloso, J. F. C. A.

In: Canadian Journal of Physics, 2007, vol. 85, no. 5, p. 469-478

The Lamb-shift experiment in muonic hydrogen (μ⁻ p) aims to measure the energy difference between the 2SF=11/2-2PF=23/2 atomic levels to a precision of 30 ppm. This would allow the r.m.s. proton charge radius rp to be deduced to a precision of 10⁻³ and open a way to check bound-state quantum electrodynamics (QED) to...

Université de Fribourg

Muonic hydrogen cascade time and lifetime of the short-lived 2S

Ludhova, Livia ; Amaro, F. D. ; Antognini, A. ; Biraben, F. ; Cardoso, J. M. R. ; Conde, C. A. N. ; Dax, A. ; Dhawan, S. ; Fernandes, L. M. P. ; Hänsch, T. W. ; Hughes, V. W. ; Indelicato, P. ; Julien, L. ; Knowles, Paul E. ; Kottmann, F. ; Liu, Y.-W. ; Lopes, J. A. M. ; Monteiro, C. M. B. ; Mulhauser, Françoise ; Nez, F. ; Pohl, R. ; Rabinowitz, P. ; Santos, J. M. F. dos ; Schaller, Lukas A. ; Schwob, C. ; Taqqu, D. ; Veloso, J. F. C. A.

In: Physical Review A, 2007, vol. 75, p. 040501(R)

Metastable 2S muonic-hydrogen atoms undergo collisional 2S quenching, with rates which depend strongly on whether the µp kinetic energy is above or below the 2S -P energy threshold. Above threshold, collisional 2S -P excitation followed by fast radiative 2P -S deexcitation is allowed. The corresponding short-lived...

Université de Fribourg

Powerful fast triggerable 6 μm laser for the muonic hydrogen 2S-Lamb shift experiment

Antognini, A. ; Amaro, F. D. ; Biraben, F. ; Cardoso, J. M. R. ; Conde, C. A. N. ; Covita, D. S. ; Dax, A. ; Dhawan, S. ; Fernandes, L. M. P. ; Hänsch, T. W. ; Hughes, V. W. ; Huot, Olivier ; Indelicato, P. ; Julien, L. ; Knowles, Paul E. ; Kottmann, F. ; Liu, Y.-W. ; Lopes, J. A. M. ; Ludhova, Livia ; Monteiro, C. M. B. ; Mulhauser, Françoise ; Nez, F. ; Perry, B. N. ; Pohl, R. ; Rabinowitz, P. ; Santos, J. M. F. dos ; Schaller, Lukas A. ; Schwob, C. ; Taqqu, D. ; Veloso, J. F. C. A.

In: Optics Communications, 2005, vol. 253 (4-6), p. 362-374

Laser spectroscopy of the 2S-Lamb shift in muonic hydrogen (μ−p) is being performed at the Paul Scherrer Institute, Switzerland, to determine the root-mean-square (rms) proton charge radius with 10−3 precision. A multistage laser system has been developed which provides 0.2 mJ pulse energy tunable at 6 μm wavelength. An excimer pumped dye laser is used to drive a...

Université de Fribourg

Planar LAAPDs: temperature dependence, performance, and application in low-energy X-ray spectroscopy

Ludhova, Livia ; 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. ; Hänsch, T. W. ; Hughes, V.-W. ; Huot, Olivier ; Indelicato, P. ; Julien, L. ; Knowles, Paul E. ; Kottmann, F. ; Lopes, J. A. M. ; Liu, Y.-W. ; Monteiro, C. M. B. ; Mulhauser, Françoise ; Nez, F. ; Pohl, R. ; Rabinowitz, P. ; Santos, J. M. F. dos ; Schaller, Lukas A. ; Taqqu, D. ; Veloso, J. F. C. A.

In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2005, vol. 540, p. 169-179

An experiment measuring the 2S Lamb shift in muonic hydrogen (μ-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...