  In this paper, we are concerned with the minimal regularity of weak solutions
implying the law of balance for both energy and helicity in the incompressible
Euler equations. In the spirit of recent works due to Berselli [5] and
Berselli-Georgiadis [6], it is shown that the energy of weak solutions is
invariant if $v\in L^{p}(0,T;B^{\frac1p}_{\frac{2p}{p-1},c(\mathbb{N})} )$ with
$1<p\leq3$ and the helicity is conserved if $v\in
L^{p}(0,T;B^{\frac2p}_{\frac{2p}{p-1},c(\mathbb{N})} )$ with $2<p\leq3 $ for
both the periodic domain and the whole space, which generalizes the classical
work of Cheskidov-Constantin-Friedlander-Shvydkoy in [10]. This indicates the
role of the time integrability, spatial integrability and differential
regularity of the velocity in the conserved quantities of weak solutions of the
ideal fluid.
