Hadronic molecular states composed of heavy flavor baryons.

We investigate the possible molecules composed oftwo heavy flavor baryons such as "AQBQ" (Q = b,c) within the one-pion-exchange model (OPE). Our results indicate that the long-range 7r exchange force is strong enough to form molecules such as [&Sgr;QΞ1Q]I=1/2S=1(Q = b, c), [&Sgr;Q&Lgr;Q]I=1S=1 (Q = b, c), [&Sgr;Ξ1b]I=3/2S=1, and [ΞbΞIb]I=0S=1 where the S-D mixing plays an important role. In contrast, the &pgr; exchange does not form the spin-singlet AQBQ bound states. If we consider the heavier scalar and vector meson exchanges as well as the pion exchange, some loosely bound spin-singlet S-wave states appear while results of the spin-triplet AQBQ system do not change significantly, which implies the pion exchange plays an dominant role in forming the spin-triplet molecules. Moreover, we perform an extensive coupled channel analysis of the &Lgr;Q&Lgr;Q system within the OPE and one-boson-exchange framework and find that there exist loosely bound states of &lgr;Q&Lgr;Q (Q = b, c) with quantum numbers I(JP) = 0(0+), 0(0+), and 0(1-). The binding solutions of &Lgr;Q&Lgr;Q system mainly come from the coupled-channel effect in the flavor space. Besides the OPE force, the medium- and short-range attractive force also plays a significant role in the formation of the loosely bound &Lgr;c&Lgr;c. and &lgr;b&Lgr;b states. Once produced, they will be very stable because such a system decays via weak interaction with a very long lifetime around 10-13-10-12 s. [ABSTRACT FROM AUTHOR]