Subleading Isgur–Wise function of Λb→Λc1 using QCD sum rules

Subleading Isgur–Wise form factor τ(v·v′) at O(1/mQ) for Λb→Λc11/2,3/2 weak transition is calculated by using the QCD sum rules in the framework of the heavy quark effective theory (HQET), where Λ1/2c1 and Λ3/2c1 are the orbitally excited charmed baryon doublet with JP=(1−/2,3−/2). We consider the subleading contributions from the weak current matching in the HQET. The interpolating currents with transverse covariant derivative are adopted for Λ1/2c1 and Λ3/2c1 in the analysis. The slope parameter ρ2 in linear approximation of τ is obtained to be ρ2=2.76 and the interception to be τ(1)=−1.27 GeV.