CERN Accelerating science

The $J/\psi \pi^{\pm}$ invariant mass distribution for the ``displaced-vertex'' candidates at $4.2

The $J/\psi \pi^+ \pi^-$ decay length in the transverse plane for events in the range $4.2

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.4--4.5~GeV, 4.5--4.6~GeV, and 4.6--4.7~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The $Z_c^+(3900)$ signal yield per 100 MeV for the six intervals of $m(J/\psi \pi^+ \pi^-)$: 4.1--4.2, 4.2--4.3, 4.3--4.4, 4.4--4.5, 4.5--4.6 and 4.6--4.7~GeV for (a) ``displaced vertex'' and (b) ``primary vertex'' selection. The points are placed at the bin centers.

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.4--4.5~GeV, 4.5--4.6~GeV, and 4.6--4.7~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.4--4.5~GeV, 4.5--4.6~GeV, and 4.6--4.7~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.1--4.2~GeV, 4.2--4.3~GeV, and 4.3--4.4~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The $J/\psi \pi^{\pm}$ invariant mass distribution for the ``displaced-vertex'' candidates at $4.2

The $J/\psi \pi^+ \pi^-$ decay length in the transverse plane for events in the range $4.2

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.4--4.5~GeV, 4.5--4.6~GeV, and 4.6--4.7~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The $Z_c^+(3900)$ signal yield per 100 MeV for the six intervals of $m(J/\psi \pi^+ \pi^-)$: 4.1--4.2, 4.2--4.3, 4.3--4.4, 4.4--4.5, 4.5--4.6 and 4.6--4.7~GeV for (a) ``displaced vertex'' and (b) ``primary vertex'' selection. The points are placed at the bin centers.

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.1--4.2~GeV, 4.2--4.3~GeV, and 4.3--4.4~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.1--4.2~GeV, 4.2--4.3~GeV, and 4.3--4.4~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.4--4.5~GeV, 4.5--4.6~GeV, and 4.6--4.7~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.1--4.2~GeV, 4.2--4.3~GeV, and 4.3--4.4~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.1--4.2~GeV, 4.2--4.3~GeV, and 4.3--4.4~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.1--4.2~GeV, 4.2--4.3~GeV, and 4.3--4.4~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.1--4.2~GeV, 4.2--4.3~GeV, and 4.3--4.4~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.4--4.5~GeV, 4.5--4.6~GeV, and 4.6--4.7~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.1--4.2~GeV, 4.2--4.3~GeV, and 4.3--4.4~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.4--4.5~GeV, 4.5--4.6~GeV, and 4.6--4.7~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.1--4.2~GeV, 4.2--4.3~GeV, and 4.3--4.4~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.4--4.5~GeV, 4.5--4.6~GeV, and 4.6--4.7~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.1--4.2~GeV, 4.2--4.3~GeV, and 4.3--4.4~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.4--4.5~GeV, 4.5--4.6~GeV, and 4.6--4.7~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.1--4.2~GeV, 4.2--4.3~GeV, and 4.3--4.4~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.4--4.5~GeV, 4.5--4.6~GeV, and 4.6--4.7~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The $Z_c^+(3900)$ signal yield per 100 MeV for the six intervals of $m(J/\psi \pi^+ \pi^-)$: 4.1--4.2, 4.2--4.3, 4.3--4.4, 4.4--4.5, 4.5--4.6 and 4.6--4.7~GeV for (a) ``displaced vertex'' and (b) ``primary vertex'' selection. The points are placed at the bin centers.

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.4--4.5~GeV, 4.5--4.6~GeV, and 4.6--4.7~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.1--4.2~GeV, 4.2--4.3~GeV, and 4.3--4.4~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The invariant mass distribution of $J/\psi \pi^{\pm}$ candidates in three intervals of $M(J/\psi \pi^+ \pi^-)$, from top to bottom 4.4--4.5~GeV, 4.5--4.6~GeV, and 4.6--4.7~GeV. Left: events with a displaced vertex. Right: ``primary vertex'' events. Superimposed are the fits of a Breit-Wigner signal with fixed mass and width~\cite{zcpdg1} (dashed blue lines), a Chebyshev polynomial background (dashed red lines), and their sum (solid blue lines).

The $Z_c^+(3900)$ signal yield per 100 MeV for the six intervals of $m(J/\psi \pi^+ \pi^-)$: 4.1--4.2, 4.2--4.3, 4.3--4.4, 4.4--4.5, 4.5--4.6 and 4.6--4.7~GeV for (a) ``displaced vertex'' and (b) ``primary vertex'' selection. The points are placed at the bin centers.