Precision Measurement of the Mass of the $D^{*0}$ Meson and the Binding Energy of the $X(3872)$ Meson as a $D^0\overline{D^{*0}}$ Molecule

TL;DR

This paper reports a precise measurement of the $D^{*0}$ meson mass and the binding energy of the $X(3872)$ meson, supporting its interpretation as a $D^0ar{D}^{*0}$ molecule with a very small binding energy.

Contribution

It provides the most precise measurement of the $D^{*0}$ mass and the $X(3872)$ binding energy, refining the understanding of its molecular structure.

Findings

Measured $ riangle M$ between $D^0$ and $D^{*0}$ with high precision.

Determined $M(D^{*0})$ as 2006.850 MeV.

Estimated the $X(3872)$ binding energy as 3 keV with uncertainty.

Abstract

A precision measurement of the mass difference between the $D^0$ and $D^{*0}$ mesons has been made using 316~pb$^{-1}$ of $e^{+}e^{-}$ annihilation data taken at $\sqrt{s}=4170$~MeV using the CLEO-c detector. We obtain $\Delta M \equiv M(D^{*0})-M(D^0) =142.007\pm0.015$(stat)~$\pm$~0.014(syst)~MeV, as the average for the two decays, $D^0\to K^-\pi^+$ and $D^0\to K^-\pi^+\pi^-\pi^+$. The new measurement of $\Delta M$ leads to $M(D^{*0})=2006.850\pm0.049$~MeV, and the currently most precise measurement of the binding energy of the ``exotic'' meson X(3872) if interpreted as a $D^0D^{*0}$ hadronic molecule, $E_{b}(\text{X}(3872))\equiv M(D^0D^{*0})-M(\text{X}(3872))=3\pm192$ keV.