Proton-tetraneutron elastic scattering

We analyze the elastic scattering of protons on a 4n system. This was used as part of the detection technique of a recent experiment [F. M. Marqués et al. Phys. Rev. C 65, 044006 (2002)] to search for the 4n (tetra-neutron) as a bound particle. We show that it is unlikely that this process alone could yield the events reported in F. M. Marqués et al., [Phys. Rev. C 65, 044006 (2002)], unless the 4n has an anomalously large backward elastic scattering amplitude. DOI: 10.1103/PhysRevC.69.027601 PACS number(s): 25.60.Bx, 25.10.1s The possible existence of the tetraneutron has been dis-cussed theoretically by numerous authors already in the 1960s (see Refs. [1–3] and references therein). Numerous experiments have been performed with negative results ([1–3] and references therein). However, in a recent experi-ment [1], the existence of bound neutron clusters was studied by fragmentation of intermediate energy s35 MeV/nucleond 14Be nuclei. As described in Ref. [1], the data analysis was confined (for technical reasons related to the detector re