New Attempt to Determine the <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="italic">n</mi><mi mathvariant="italic">−</mi><mi mathvariant="italic">n</mi></math></span> Scattering Length with the <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>H</mi></mrow><mprescripts></mprescripts><mrow></mrow><mrow><mn>2</mn></mrow><mrow></mrow><mrow></mrow></mmultiscripts></mrow><mo>(</mo><mi mathvariant="italic">n</mi><mo>,</mo><mi mathvariant="italic">n</mi><mi mathvariant="italic">p</mi><mo>)</mo><mi mathvariant="italic">n</mi></math></span> Reaction

V. Huhn; L. Wätzold; Ch. Weber; A. Siepe; W. von Witsch; H. Witała; W. Glöckle

doi:10.1103/PhysRevLett.85.1190

New Attempt to Determine the $n - n$ Scattering Length with the ${}^{2}H (n, n p) n$ Reaction

V. Huhn, L. Wätzold, Ch. Weber, A. Siepe, W. von Witsch, H. Witała, and W. Glöckle

Phys. Rev. Lett. 85, 1190 – Published 7 August 2000

Abstract

The $n - n$ final-state interaction (FSI) was investigated via the $^{2} H (n, n p) n$ reaction at 25 MeV, using a geometry which enables the simultaneous observation of $n - p$ quasifree (QFS) scattering. The data were analyzed with Monte Carlo simulations based on rigorous Faddeev calculations with realistic nucleon-nucleon potentials. The value of $a_{nn}$ deduced from the absolute yield in the FSI peak is $- 16.27 \pm 0.40 fm$ while the relative data, normalized in the QFS region, give $- 16.06 \pm 0.35 fm$ . Thus our results differ from the “recommended” value of $a_{nn} = - 18.5 \pm 0.3 fm$ by more than 5 standard deviations.

Received 3 April 2000

DOI:https://doi.org/10.1103/PhysRevLett.85.1190

Authors & Affiliations

V. Huhn, L. Wätzold, Ch. Weber, A. Siepe, W. von Witsch, H. Witała^*, and W. Glöckle^†

Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany

^*Permanent address: Institute of Physics, Jagellonian University, Reymonta 4, PL-30059 Cracow, Poland.
^†Permanent address: Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum, Germany.