Abstract:
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Narrow highly excited states with halfwidth of $\Gamma \approx 
0.4$ MeV have been recently detected [1] in nuclei formed in pickup 
reactions $A_1(d,^3He)A_2^*$. They were observed in kinetic energy spectra 
of $^3$He ejectiles. The measurements were performed with targets of 
$^{116,120,124}$Sn isotopes in recoil-free kinematics. The last requires 
for the two-body reaction $m_1+A_1 -->m_2+A_2^* $ the proper projectile 
momentum
\begin{eqnarray} 
p_1=\sqrt{[\Delta^2 -(m_1+m_2)^2] [\Delta^2 -(m_1-m_2)^2]}c/(2 \Delta)
\end{eqnarray}
where $\Delta=A_1-A_2$ is a mass difference between nuclei $A_1$ and 
$A_2$.
       If one changes $^3$He ejectiles by hyperhydrogen nuclei the 
possibility is opened to search for narrow highly excited states with 
positive strangeness. The following tables contain examples of appropriate 
reactions for experimental investigations. Projectile and ejectile kinetic 
energies are also determined for excitation of $A_2^*$ at the level of 590 
MeV.

Reaction                                           $T_1$, MeV   $T_2$, MeV

p +$^{120}$Sn --> $^{118}A_2^*$ +$^3H_1^{\Lambda}$      1589        811

p +$^{120}$Sn --> $^{117}A_2^*$ +^4H_1^{\Lambda}         1248       469

$\pi^+$ + $^{120}$Sn --> $^{119}A_2^*$ +$\Lambda$        1489       854 

$K^+$ + $^{120}$Sn --> $^{119}A_2^*$ + p                 280        173

$K^+$ + d  --> $\Theta ^+$ + p                           287        178

The last reaction is also proposed in [2].

Reaction                                     $E_{\gamma}$, MeV    $T_2$, MeV

$\gamma$ + d --> $\Theta ^+$ + $\Lambda$                 1687         907

$\gamma$ + d --> $\Theta ^+$ + $\Lambda$                 1181         400

$\gamma$ + $^{120}$Sn --> $^{119}A_2^*$+$\Lambda$        1675         987

$\gamma$ + $^{120}$Sn --> $^{119}A_2^*$+$^3_1H^{\Lambda}$ 934       142


Processes of complex nuclear disintegrations may be closely connected with 
the formation of narrow highly excited states in heavy nuclei because of 
similar recoil-free kinematics [3].

                  References

1. K.Suzuki et al., Phys. Rev. Lett. 92 (2004) 072302.
2. A.Gal and E.Friedman, Phys. Rev. Lett. 94 (2005) 072301.
3. L.N.Andronenko et al., Phys. Atom. Nucl. 65 (2002) 478.