EXA2011

Our recent measurement of the Lamb shift (2S-2P energy splitting) in muonic hydrogen [1] has created a puzzle. The value of the proton rms charge radius we deduce, Rp = 0.84184(67) fm, is ten times more accurate, but 4% smaller than the values deduced from both hydrogen spectroscopy and elastic electron scattering. In addition, we have determined the 2S hyperfine splitting in muonic hydrogen...

We are going to report preliminary experimental results in our recent pilot experiment performed in October 2010 for spectroscopy of pionic 121Sn atom in the RI beam factory, RIKEN. We have taken the excitation spectrum of the 122Sn(d,3He) reaction near the pion emission threshold. Presently, elaborate analysis is on-going and the preliminary spectrum observes a distinct structure of...

The future international accelerator Facility for Antiproton and Ion Research (FAIR) encompasses 4 scientific pillars containing, at this time, 14 approved technical proposals worked out by more than 2000 scientists from all over the world. They offer a wide range of new and challenging opportunities for atomic physics research in the realm of highly-charged heavy ions and exotic nuclei. As...

The ground-state level shifts and broadenings of the hydrogen isotopes caused by the strong interaction have been determined by using a high-resolution crystal spectrometer. From these parameters are derived the pion-nucleon and pion-deuteron scattering lengths and the threshold production and absorption strength of pions in nucleon-nucleon reactions. Muonic hydrogen reveals properties in the...