Author/Authors :
H.-Ch. Schr?der، نويسنده , , A. Badertscher، نويسنده , , P.F.A. Goudsmit، نويسنده , , M. Janousch، نويسنده , , H.J. Leisi، نويسنده , , E. Matsinos، نويسنده , , D. Sigg، نويسنده , , Z.G. Zhao، نويسنده , , D. Chatellard، نويسنده , , J.-P. Egger، نويسنده , , E. Jeannet، نويسنده , , K. Gabathuler، نويسنده , , P. Hauser، نويسنده , , L.M. Simons، نويسنده , , A.J. Rusi El Hassani، نويسنده ,
Abstract :
The final results from the pionic hydrogen X-ray experiment at PSI are presented. With this experiment the strong interaction energy level shift ε1s and the total decay width Γ1s of the 1s state of pionic hydrogen were obtained from a precise measurement of the 3p–1s X-ray line: ε1s=−7.108±0.013(stat.)±0.034(syst.) eV (attractive) and Γ1s = 0.868±0.040(stat.)±0.038(syst.) eV. The corresponding hadronic πN s-wave scattering lengths for elastic scattering and single charge exchange are: aπ−p→π−p=0.0883±0.0008 m−1π and aπ−p→π0n=−0.128±0.006 m−1π. Combining the results of the pionic hydrogen and deuterium measurements, the isoscalar (b0) and isovector (b1) scattering lengths, corresponding to an isospin symmetric interaction, can be calculated: b0=0.0016±0.0013 m−1π and b1=−0.0868±0.0014 m−1π.
