Naslov
Measurement of Charge Symmetry Breaking by the Comparison of Pi^+d->p p Eta with Pi^-d->n n Eta

Autori
Tippens, W.B. ; Abaev, V. ; Batinić, Mijo ; Bekrenev, V. ; Briscoe, W.J. ; Chiren, R.E. ; Clajus, M. ; Isenhower, D. ; Kozlenko, N. ; Kruglov, S. ; Leitch, M.J. ; Marušić, Aljoša ; Moriwaki, T. ; Morrison, T. ; Nefkens, B.M.K. ; Peng, J.C. ; Pile, P.H. ; Price, J.W. ; Rigsby, D. ; Sadler, M.E. ; Sawafta, R. ; Šlaus, Ivo ; Seyfarth, H. ; Starostin, A. ; Supek, Ivan ; Sutter, R.J. ; Švarc, Alfred ; White, D.B.

Izvornik
Physical review. D, Particles and fields (0556-2821) 63 (2001), 5; 052001, 16

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Radovi u časopisima, članak, znanstveni

Ključne riječi
charge symmetry breaking ; NN Ni system ; differential cross section

Sažetak
We report a measurement of charge symmetry breaking in the NN Eta system. We have measured the ratio of the differential cross sections of the charge-symmetric reactions Pi^+d->p p Eta with Pi^-d->n n Eta in the energy region of the Eta threshold. Our result is R=d Sigma(Pi^+d->ppEta)/d Sigma(Pi^-d->nn Eta)=0.938+-0.009 after a phase-space correction is made for the difference in the threshold energies of the two reactions. The deviation of R from unity is an indication of charge symmetry breaking, which is mostly due to Pi^0 - Eta mixing. A theoretical model for Eta production which includes Pi^0 - Eta mixing was used to fit the data and yields a mixing angle of (1.5+-0.4)^o. Our result is consistent with the mixing angle determined in particle decay and isospin-forbidden processes as well as predictions by several theoretical analyses which yield ~ 1^o and another which yields ~ 2^o.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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