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a{sub 0}{sup +} (980)-resonance production in the reaction pp {sup {yields}} d{pi}{sup +}{eta} close to the KK-bar threshold

Journal Article · · Physics of Atomic Nuclei
;  [1];  [2];  [1];  [3]; ; ;  [1];  [4];  [1];  [2];  [5];  [2];  [1];  [6];  [5]; ; ; ;  [1]
  1. Forschungszentrum Juelich, Institut fuer Kemphysik (Germany)
  2. Institute for Theoretical and Experimental Physics (Russian Federation)
  3. Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)
  4. Universitaet zu Koeln, Institut fuer Kemphysik (Germany)
  5. Petersburg Nuclear Physics Institute (Russian Federation)
  6. Joint Institute for Nuclear Research (Russian Federation)
The reaction pp {sup {yields}} d{pi}{sup +}{eta} has been measured at a beam energy of T{sub p} = 2.65 GeV (p{sub p} = 3.46 GeV/c) using the ANKE spectrometer at COSY-Julich. The missing-mass distribution of the detected d{pi}{sup +} pairs exhibits a peak around the {eta} mass on top of a strong background of multipion pp {sup {yields}} d{pi}{sup +}(n{pi}) events. The differential cross section d{sup 4}{sigma}/d{omega}{sub d}d{omega}{sub {pi}}{sup +}dp{sub d}dp{sub {pi}}{sup +} for the reaction pp {sup {yields}} d{pi}{sup +}{eta} has been determined model independently for two regions of phase space. Employing a dynamical model for the a{sub 0}{sup +} production allows one then to deduce a total cross section of {sigma}(pp {sup {yields}} da{sub 0}{sup +} {sup {yields}} d{pi}{sup +}{eta}) = 1.1 {+-} 0.3{sub stat} {+-} 0.7{sub syst} {mu}b for the production of {pi}{sup +}{eta} via the scalar a{sub 0}{sup +}(980) resonance and {sigma}(pp {sup {yields}} d{pi}{sup +}{eta}) = 3.5 {+-} 0.3{sub stat} {+-} 1.0{sub syst} {mu}b for the nonresonant production. Using the same model as for the interpretation of recent results from ANKE for the reaction pp{yields}dK{sup +}K-bar{sup 0}, the ratio of the total cross sections is {sigma}(pp{yields}d(K{sup +}K-bar{sup 0}){sub L=0})/{sigma}(pp{yields}da{sub 0}{sup +}{yields}d{pi}{sup +}{eta})=0.029= {+-}0.008{sub stat}{+-}0.009{sub syst}, which is in agreement with branching ratios in the literature.
OSTI ID:
21076112
Journal Information:
Physics of Atomic Nuclei, Journal Name: Physics of Atomic Nuclei Journal Issue: 2 Vol. 69; ISSN 1063-7788; ISSN PANUEO
Country of Publication:
United States
Language:
English