Author/Authors :
Betigeri، نويسنده , , M.G. and Bojowald، نويسنده , , J. and Budzanowski، نويسنده , , A. and Chatterjee، نويسنده , , A. and Drochner، نويسنده , , M. and Ernst، نويسنده , , J. and F?rtsch، نويسنده , , S. and Freindl، نويسنده , , L. and Frekers، نويسنده , , D. and Garske، نويسنده , , W. and Grewer، نويسنده , , K. and Hamacher، نويسنده , , A. and Hawash، نويسنده , , M. and Igel، نويسنده , , S. and Ilieva، نويسنده , , I. and Jahn، نويسنده , , R. an، نويسنده ,
Abstract :
We present a method to determine precisely the absolute momentum of the external proton beam from the Jülich Cooler Synchrotron COSY near 1930 MeV/c. In the pp → dπ+ reaction at 1930.477 MeV/c incident beam momentum, the forward going pions (θc.m.=0°) and the backward going deuterons (θc.m.=180°) have the same laboratory momentum. Such coincident pion–deuteron events are detected in the focal plane of the magnetic spectrometer BIG KARL located at θlab=0°. Using the nearly linear dependence of the difference between the measured pion and deuteron momenta as a function of the proton beam momentum, the absolute momentum of the external proton beam from COSY near 1930 MeV/c was determined with a precision of 5.2×10−5.
Keywords :
proton beam , pions , Deuterons , 1930 MeV/c
