ENH: wrtite Barrier factor in TR029 (#25)

docs/029/index.ipynb

@@ -18,7 +18,7 @@
    },
    "source": [
     "::::{margin}\n",
-    ":::{card} Definition of the normalized Blatt–Weisskopf form factor from Hankel functions of the first kind.\n",
+    ":::{card} Definition of the normalized Blatt–Weisskopf form factor (barrier factor) from Hankel functions of the first kind.\n",
     "TR-029\n",
     "^^^\n",
     "This report investigates how to implement [ComPWA/ampform#417](https://github.com/ComPWA/ampform/issues/417), where it was suggested to define the 'normalized' Blatt–Weisskopf function $B_L^2(z)$ from a Hankel function of the first kind, $h_l^{(1)}$.\n",
@@ -111,7 +111,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "In the following, we call $F_\\ell(z)$ the _unnormalized_ Blatt–Weisskopf form factor.\n",
+    "In the following, we call $F_\\ell(z)$ the _unnormalized_ Blatt–Weisskopf form factor (barrier factor).\n",
     "Following Chung and other resources (see e.g. {cite}`Chung:1995dx`, p. 415), AmpForm implements a unitless, _normalized_ Blatt–Weisskopf factor $B_L$, meaning that $B_L(1)=1$.[^3]\n",
     "It can be defined in terms of $F_L$ as\n",
     "\n",
@@ -323,7 +323,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Normalized Blatt–Weisskopf form factor"
+    "## Normalized Blatt–Weisskopf form factor (barrier factor)"
    ]
   },
   {