First observation of the hyper superheavy hydrogen 6{\Lambda}H
Abstract
Three candidate events of the neutron-rich hypernucleus 6{\Lambda}H were uniquely identified in the FINUDA experiment at DA{\Phi}NE, Frascati, by observing {\pi}+ mesons from the (K-stop,{\pi}+) production reaction on 6Li targets, in coincidence with {\pi}-mesons from 6{\Lambda}H \rightarrow 6He+{\pi}- weak decay. Details of the experiment and the analysis of its data are reported, leading to an estimate of (2.9\pm2.0)\cdot10-6/K- stop for the 6{\Lambda}H production rate times the two-body {\pi}- weak decay branching ratio. The 6{\Lambda}H binding energy with respect to 5H + {\Lambda} was determined jointly from production and decay to be B{\Lambda} = (4.0 \pm 1.1) MeV, assuming that 5H is unbound with respect to 3H + 2n by 1.7 MeV. The binding energy determined from production is higher, in each one of the three events, than that determined from decay, with a difference of (0.98 \pm 0.74) MeV here assigned to the 0+g.s. \rightarrow 1+ excitation. The consequences of this assignment to {\Lambda} hypernuclear dynamics are briefly discussed.
Keywords
Cite
@article{arxiv.1203.1954,
title = {First observation of the hyper superheavy hydrogen 6{\Lambda}H},
author = {M. Agnello and L. Benussi and M. Bertani and H. C. Bhang and G. Bonomi and E. Botta and M. Bregant and T. Bressani and S. Bufalino and L. Busso and D. Calvo and P. Camerini and B. Dalena and F. De Mori and G. D'Erasmo and F. L. Fabbri and A. Feliciello and A. Filippi and E. M. Fiore and A. Fontana and H. Fujioka and P. Genova and P. Gianotti and N. Grion and V. Lucherini and S. Marcello and N. Mirfakhrai and F. Moia and O. Morra and T. Nagae and H. Outa and A. Pantaleo and V. Paticchio and S. Piano and R. Rui and G. Simonetti and R. Wheadon and A. Zenoni and A. Gal},
journal= {arXiv preprint arXiv:1203.1954},
year = {2012}
}
Comments
20 pages, 8 figures, version matching published Nuclear Physics A manuscript