Publications (1)0 Total impact
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The GEM Collaboration,
A. Budzanowski,
A. Chatterjee,
R. Gebel,
P. Hawranek,
R Jahn,
V. Jha,
K. Kilian,
S. Kliczewski,
Da. Kirillov, [......],
D. Protić,
J. Ritman,
P. von Rossen,
B. J. Roy, U. Sitnik,
R. Siudak,
R. Tsenov,
J. Urban,
G. Vankova,
C. Wilkin
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ABSTRACT: The angular distributions of the unpolarised differential cross section and tensor analysing power $A_{xx}$ of the $\vec{d}d\to\alpha \eta$ reaction have been measured at an excess energy of 16.6 MeV. The ambiguities in the partial-wave description of these data are made explicit by using the invariant amplitude decomposition. This allows the magnitude of the s-wave amplitude to be extracted and compared with results published at lower energies. In this way, firmer bounds could be obtained on the scattering length of the $\eta \alpha$ system. The results do not, however, unambiguously prove the existence of a quasi-bound $\eta \alpha$ state. Comment: 20 pages, 11 figures
11/2008;
