2019 Impact factor 2.176
Hadrons and Nuclei

Eur. Phys. J. A 14, 247-254 (2002)
DOI: 10.1140/epja/i2001-10195-x

Polarization phenomena by deuteron fragmentation into pions

A.Yu. Illarionov, A.G. Litvinenko and G.I. Lykasov

Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia


(Received: 17 April 2001 / Revised version: 7 March 2002 Communicated by V. Vento)

The fragmentation of deuterons into pions emitted forward in the kinematic region forbidden for free nucleon-nucleon collisions is analyzed. The inclusive relativistic invariant spectrum of pions and the tensor analyzing power T20 are investigated within the framework of an impulse approximation using various deuteron wave functions. The influence of ${\mathcal P}$-wave inclusion in the deuteron wave function is also studied. The invariant spectrum is shown to be more sensitive to the amplitude of the $NN \to \pi X$ process than the tensor analyzing power T20. It is shown that the inclusion of the non-nucleonic degrees of freedom in a deuteron results in a satisfactory description of the data for the inclusive pion spectrum and improves the description of the data about T20. According to the data, T20 has very small positive values, less than 0.2, which contradicts the theoretical calculations ignoring these degrees of freedom.

25.10.+s - Nuclear reactions involving few-nucleon systems.
24.70.+s - Polarization phenomena in reactions.
24.10.Jv - Relativistic models.

© Società Italiana di Fisica, Springer-Verlag 2002