An antiproton-proton partial-wave analysis

Conference · Mon Nov 01 04:00:00 EST 1993

OSTI ID:10193978

Timmermans, R ^[1]; Rijken, T A; de Swart, J J ^[2]

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1. Los Alamos National Lab., NM (United States)
2. Katholieke Univ. Nijmegen (Netherlands). Inst. for Theoretical Physics

Partial-wave analyses (PWAs) have a long history in the fields of {pi}N and NN scattering. Due to the poor quality of low-energy antiproton beams and the resulting absence of accurate experimental data, analogous model-independent studies of the much more complex {bar p}p system have in the past always been impossible. In the pre-LEAR era spin-dependent observables and charge-exchange ({bar p}p - {bar n}n) data were almost nonexistent, the situation between 400 and 925 MeV/c is now quite good. High-quality analyzing-power data have been obtained for the elastic and charge-exchange reactions. Very recently, even charge-exchange depolarization data have become available. Unfortunately, the practical difficulties involved in constructing a high-quality ``cooled`` antiproton beam of lower momentum are large. Consequently, the {bar p}p database below about 400 MeV/c is still by far not as good as one would like, in striking contrast to the pp case where very accurate data exist as low as T{sub L} = 0.35 MeV. It also remains an outstanding experimental challenge to construct a polarized antiproton beam to further probe the spin structure of the interaction. A new method has been developed by the Nijmegen group to perform PWAs of the abundant and accurate NN scattering data below T{sub L} = 350 MeV. With the now available high-quality data from LEAR and KEK, we have been able to extend the methods used in these NN PWAs to perform an energy-dependent PWA of all {bar p}p scattering data below p{sub L} = 925 MeV/c. The same methods of PWA have also been applied to the strangeness-exchange reaction {bar p}p {yields} {bar {lambda}}{lambda}, for which the PS185 group at LEAR has obtained beautiful data. In the next section we review the theoretical ideas behind these Nijmegen PWAS, and we apply these ideas and methods to the case of {bar p}p scattering. In section IV some results of this {bar p}p PWA are presented and discussed.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 10193978
• Report Number(s): LA-UR--93-3728; CONF-9308164--5; ON: DE94002690
• Country of Publication: United States
• Language: English

Related Subjects

662340
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANALYZING POWER
DIFFERENTIAL CROSS SECTIONS
HADRON INTERACTIONS
PARTIAL WAVES
PROTON-ANTIPROTON INTERACTIONS
SCATTERING
WAVE FUNCTIONS