  The extremely neutron-rich system $^{6}$H was studied in the direct
$^2\text{H}(^8\text{He},{^4\text{He}})^{6}$H transfer reaction with a $26 A$
MeV secondary $^{8}$He beam. The measured missing mass spectrum shows a broad
bump at $\sim 4-8$ MeV above the $^3$H+$3n$ decay threshold. This bump can be
interpreted as a broad resonant state in $^{6}$H at $6.8(5)$ MeV. The
population cross section of such a presumably $p$-wave state (or may be few
overlapping states) in the energy range from 4 to 8 MeV is
$d\sigma/d\Omega_{\text{c.m.}} \simeq 190^{+40}_{-80}$ $\mu$b/sr in the angular
range $5^{\circ}<\theta_{\text{c.m.}}<16^{\circ}$. The obtained missing mass
spectrum is practically free of the $^{6}$H events below 3.5 MeV
($d\sigma/d\Omega_{\text{c.m.}} \lesssim 5$ $\mu$b/sr in the same angular
range). The steep rise of the $^{6}$H missing mass spectrum at $\sim 3$ MeV
allows to derive the lower limit for the possible resonant-state energy in
$^{6}$H to be $4.5(3)$ MeV. According to the paring energy estimates, such a
$4.5(3)$ MeV resonance is a realistic candidate for the $^{6}$H ground state
(g.s.). The obtained results confirm that the decay mechanism of the $^{7}$H
g.s.\ (located at 2.2 MeV above the $^{3}$H+$4n$ threshold) is the "true" (or
simultaneous) $4n$ emission. The resonance energy profiles and the momentum
distributions of fragments of the sequential $^{6}$H$ \,\rightarrow \,
^5$H(g.s.)+$n\, \rightarrow \, ^3$H+$3n$ decay were analyzed by the
theoretically-updated direct four-body-decay and sequential-emission
mechanisms. The measured momentum distributions of the $^{3}$H fragments in the
$^{6}$H rest frame indicate very strong "dineutron-type" correlations in the
$^{5}$H ground state decay.
