We establish new quantitative Hessian integrability estimates for viscosity supersolutions of fully nonlinear elliptic operators. As a corollary, we show that the optimal power ε=ε(λ,Λ,n) in celebrated W2,ε–regularity estimate satisfies(1+23(1−λΛ))n−1ln⁡n4⋅(λΛ)n−1≤ε≤nλ(n−1)Λ+λ, where n≥3 is dimension and 0<λ<Λ are ellipticity constants. In particular, (Λλ)n−1ε(λ,Λ,n) blows-up, as n→∞; previous ...

Exclusive semileptonic Λb decays to excited charmed Λc baryons are investigated at order ΛQCD/mQ in the heavy quark effective theory. The differential decay rates are analyzed for the Jπ = 1/2− Λc(2593) and the J π = 3/2− Λc(2625). They receive 1/mc,b corrections at zero recoil that are determined by mass splittings and the leading order Isgur-Wise function. With some assumptions, we find that ...