Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Weak $\Lam N\to NN$ Transition in the Direct Quark Mechanism   The weak $\Lam N\to NN$ transition is studied in the valence quark model
approach. The momentum transfer for this transition is so large that the
short-distance two baryon dynamics must be taken into account. The two baryon
system is described in the quark cluster model and the weak transition
amplitude is calculated by evaluating the matrix elements of the effective weak
$\Delta S= 1$ hamiltonian. The results indicate some qualitative differences
when compared with those in conventional meson-exchange calculations.
Especially, we conclude that contributions of the $\Delta I={3\over2}$
transition are significant and that the discrepancy in the $n-p$ ratio between
theory and experiment could be resolved by including the direct-quark
processes.

15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
16
The categories of this paper are: stat
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio