  Central Limit Theorems are known for the Eulerian statistic "descent" (or
"excedance") in the symmetric group $\SSS_n$. Recently, Fulman, Kim, Lee and
Petersen gave a Central Limit Theorem for "descent" over the alternating group
$\AAA_n$ and also gave a Carlitz identity in $\AAA_n$ using descents.
  In this paper, we give a Central Limit Theorem in $\AAA_n$ involving
excedances. We extend these to the positive elements in type B and type D
Coxeter groups. Boroweic and M\l{}otkowski enumerated type B descents over
$\DD_n$, the type D Coxeter group and gave similar results. We refine their
results for both the positive and negative part of $\DD_n$. Our results are a
consequence of signed enumeration over these subsets.

Combinatorics