Investigation of exotic state X(3872) in $pp$ collisions at $\sqrt{s}=$7 and 13 TeV.

The production of particles $D$, $\bar D^{*}$ simulated in pp collisions at $\sqrt{s}=7$ TeV at mid-rapidity using the PACIAE model. The simulation results of $D^{0}$, $D^{+}$, $D^{*+}$, $\pi^{+}$ and $K^{+}$ from PACIAE agree well with the experimental results. The $X(3872)$ could be tetraquarks state, nucleus-like state and molecular state. Then, we use a dynamically constrained phase-space coalescence model plus PACIAE model to produce the $D\bar D^{*}$ bound states and study the exotic state $X(3872)$ as different structures in $pp$ collisions at $\sqrt{s}=7$ and 13 TeV. The yield, transverse momentum distribution, and rapidity distribution of the exotic state $X(3872)$ as tetraquarks state, nucleus-like state and molecular state were predicted.