fix: update normalization constant calculation in SmoothedPowerlawPrimaryMassRatio

src/gwkokab/models/mass/_models.py

@@ -651,10 +651,12 @@ def __init__(
         # Compute the normalization constant for primary mass distribution
 
         self._m1s = jnp.linspace(mmin, mmax, 1000)
-        self._logZ = jnp.trapezoid(
-            jnp.exp(self._log_prob_m1_unnorm(self._m1s)),
-            self._m1s,
-            axis=0,
+        self._logZ = jnp.log(
+            jnp.trapezoid(
+                jnp.exp(self._log_prob_m1_unnorm(self._m1s)),
+                self._m1s,
+                axis=0,
+            )
         )
 
         # Compute the normalization constant for mass ratio distribution