Search for structure in the $B_s^0\pi^\pm$ invariant mass spectrum

TL;DR

This study searches for exotic meson states in the $B_s^0 o ext{pi}^ ext{pm}$ invariant mass spectrum using LHCb data, but finds no significant signals and sets upper limits on possible production rates.

Contribution

The paper provides the first LHCb-based search for exotic $B_s^0 ext{pi}^ ext{pm}$ states and establishes upper limits on their production.

Findings

No significant excess observed in the $B_s^0 ext{pi}^ ext{pm}$ spectrum.

Upper limits set on the production rate of the $X(5568)$ and similar states.

Limits depend on the mass and width of potential exotic mesons.

Abstract

The $B_s^0\pi^\pm$ invariant mass distribution is investigated in order to search for possible exotic meson states. The analysis is based on a data sample recorded with the LHCb detector corresponding to $3$ fb$^{-1}$ of $pp$ collision data at $\sqrt{s} = 7$ and $8$ TeV. No significant excess is found, and upper limits are set on the production rate of the claimed $X(5568)$ state within the LHCb acceptance. Upper limits are also set as a function of the mass and width of a possible exotic meson decaying to the $B_s^0\pi^\pm$ final state. The same limits also apply to a possible exotic meson decaying through the chain $B_s^{*0}\pi^\pm$, $B_s^{*0} \to B_s^0 \gamma$ where the photon is excluded from the reconstructed decays.