What question did this study set out to answer?

To measure the masses and widths of specific charm meson states, namely D*^0_2 and D*^+_2.

March 5, 2026Open Access

Results on Charmed Meson Spectroscopy from FOCUS

Key Points

To measure the masses and widths of specific charm meson states, namely D*^0_2 and D*^+_2.
Preliminary measurement conducted by the FOCUS Collaboration at Fermilab
Analysis of decay channels to D^+pi^- and D^0pi^+
Fit of the invariant mass distribution including terms for background structures
D*^0_2 state observed with mass of 2463.5 MeV/c^2 and width measurements
D*^+_2 state reported with mass of 2468.2 MeV/c^2 and width measurements
An additional term required in the fit to describe a broad structure in the mass distribution

Abstract

We report the preliminary measurement by the FOCUS Collaboration (E831 at Fermilab) of masses and widths of the L=1 charm mesons: a D*⁰₂ state of mass (width) 2463. 5 ±1. 5 ±1. 5 (30. 5 ±1. 9 ±3. 8) MeV/c² decaying to D^+pi^-, and a D*^+₂ state of mass (width) 2468. 2 ±1. 5 ±1. 4 (28. 6 ±1. 3 ±3. 8) M V /c 2 decaying to D⁰pi^+. The fit of the invariant mass distribution requires an additional term to account for a broad structure over background.

Bookmark

View Full Paper