  We have performed low-temperature specific-heat measurements in magnetic
fields for a single crystal UBe13. It has been observed that our sample
exhibits a superconducting transition at an intermediate temperature between
previously reported values for two variant samples called H type and L type.
The specific heat C(T) of our sample shows a T^3 behavior in the temperature
range below 0.7 Tc, which is similar to the behavior of the H-type sample,
suggesting the existence of point nodes in the superconducting gap function. We
have obtained the upper-critical-field curves Hc2 for the [001], [110], and
[111] crystal axes, which show no anisotropy at least down to the lowest
measured temperature of 0.5 K. We have also derived the Maki parameter kappa2,
and it has been revealed that the kappa2 steeply decreases isotropically upon
cooling just below Tc. Paramagnetic effects and the symmetry of Cooper pairing
of UBe13 are discussed.
