THE LAMBDA(B)-]SIGMA(C)(ASTERISK) FORM-FACTORS TO 2ND-ORDER POWER CORRECTIONS IN THE HEAVY-QUARK EFFECTIVE THEORY

The suppressed LAMBDA(b) --> SIGMA(c) decay form factors are analyzed using the heavy quark effective theory (HQET) to second order power co rrections. We find that to order 1/m(c) and 1/m(b), four form factors are needed to describe these decays while to order 1/m(c)2, 1/m(b)2 an d 1/m(c)m(b), 26 more form factors are introduced. Our result for the 1/mc contribution is at variance with the previous result. It is shown that at the zero-recoil point 1/m(c)2 and 1/m(c)m(b) terms are the le ading ones contributing to LAMBDA(b) --> SIGMA(c) and LAMBDA(b) --> SI GMA(c) respectively. We also give a rough estimate for the decay width LAMBDA(b) --> SIGMA(c)lnu.