Which is hotter the habanero pepper or the ghost chili pepper?

Jalapeno peppers are significantly weaker than cayenne peppers.

Here is the comparison given in Scoville Heat Units (SHU)

Jalapeno 3,500-8,000

Cayenne 30,00-50,000

The Scoville scale quantifies the concentration of Capsaicin. Capsaicin is the chemical which causes the sensation known as "spicy."

This means that the Cayenne pepper is about 6-8 times hotter than the Jalapeno.