World average values for excited \(D_{(s)}\) mesons
(updated June 2021)

 

People working on this: Tara Nanut

Mass and width averages

An average mass and width is calculated wherever possible. The calculation of the averages assumes no correlation between individual measurements. The masses and widths of narrow (\(\Gamma<50\) MeV) orbitally excited \(D\) mesons, both neutral and charged, are well-established. Measurements of broad states (\(\Gamma\sim\) 200–400 MeV) are less abundant, as identifying the signal is more challenging.

[Click on plots for high resolution .pdf files]
D masses       D masses

 

D masses       D masses

 

Tables of measured masses and widths, and our world averages, are here: \(D_s\) mesons, \(D\) mesons (1/2).

 

Branching fraction averages

Detailed tables of measurements of branching fractions for: \(D\) mesons (1/2), \(D_s\) mesons. It is notable that the branching fractions for \(B\) mesons decaying to a narrow \(D^{\ast\ast}\) state and a pion are similar for charged and neutral \(B\) initial states, while the branching fractions to a broad \(D^{\ast\ast}\) state and \(\pi^+\) are much larger for \(B^+\) than for \(B^0\).

Mass differences

A summary of mass difference measurements is listed here.

Helicity parameter

A summary of helicity parameter measurements is listed here. In \(D^{\ast\ast}\) meson decays to \(D^{\ast\ast} \to D^{\ast}\pi\), \(D^{\ast} \to D \pi\), the helicity distribution is dependent on the helicity parameter, which is sensitive to possible S-wave contributions in the decay.

 


This page is maintained by Tara Nanut and A. Schwartz and was last updated