pdgLive Home   >   LIGHT UNFLAVORED MESONS ($\mathit S$ = $\mathit C$ = $\mathit B$ = 0)   >   ${{\mathit \rho}{(770)}}$

LIGHT UNFLAVORED MESONS ($\mathit S$ = $\mathit C$ = $\mathit B$ = 0) For $\mathit I = 1$ (${{\mathit \pi}}$, ${{\mathit b}}$, ${{\mathit \rho}}$, ${{\mathit a}}$): ${\mathit {\mathit u}}$ ${\mathit {\overline{\mathit d}}}$, (${\mathit {\mathit u}}$ ${\mathit {\overline{\mathit u}}}−{\mathit {\mathit d}}$ ${\mathit {\overline{\mathit d}}})/\sqrt {2 }$, ${\mathit {\mathit d}}$ ${\mathit {\overline{\mathit u}}}$; for $\mathit I = 0$ (${{\mathit \eta}}$, ${{\mathit \eta}^{\,'}}$, ${{\mathit h}}$, ${{\mathit h}^{\,'}}$, ${{\mathit \omega}}$, ${{\mathit \phi}}$, ${{\mathit f}}$, ${{\mathit f}^{\,'}}$): ${\mathit {\mathit c}}_{{\mathrm {1}}}({{\mathit u}}{{\overline{\mathit u}}}$ $+$ ${{\mathit d}}{{\overline{\mathit d}}}$) $+$ ${\mathit {\mathit c}}_{{\mathrm {2}}}({{\mathit s}}{{\overline{\mathit s}}}$)

INSPIRE   JSON PDGID: M009

${{\mathit \rho}{(770)}}$ $I^G(J^{PC})$ = $1^+(1^{- -})$

See related review:
Spectroscopy of Light Meson Resonances

Expand/Collapse All

${{\mathit \rho}{(770)}}$ T-MATRIX POLE $\sqrt {\mathit s }$ $(761 - 765) - i (71 - 74)$ MeV

▸  exp ${{\mathit \rho}{(770)}}$ MASS

NEUTRAL ONLY, ${{\mathit e}^{+}}{{\mathit e}^{-}}$ [1] $775.26$ $\pm0.23$ MeV

CHARGED ONLY, ${{\mathit \tau}}$ DECAYS and ${{\mathit e}^{+}}{{\mathit e}^{-}}$ [2] $775.11$ $\pm0.34$ MeV

MIXED CHARGES, OTHER REACTIONS $763.0$ $\pm1.2$ MeV

CHARGED ONLY, HADROPRODUCED $766.5$ $\pm1.1$ MeV

NEUTRAL ONLY, PHOTOPRODUCED $769.2$ $\pm0.9$ MeV

NEUTRAL ONLY, OTHER REACTIONS $769.0$ $\pm0.9$ MeV (S = 1.4)

${\mathit m}_{{{\mathit \rho}{(770)}^{0}}}-{\mathit m}_{{{\mathit \rho}{(770)}^{\pm}}}$ $-0.7$ $\pm0.8$ MeV (S = 1.5)

${\mathit m}_{{{\mathit \rho}{(770)}^{+}}}-{\mathit m}_{{{\mathit \rho}{(770)}^{-}}}$

${{\mathit \rho}{(770)}}$ RANGE PARAMETER $5.3^{+0.9}_{-0.7}$ GeV${}^{-1}$

▸  exp ${{\mathit \rho}{(770)}}$ WIDTH

NEUTRAL ONLY, ${{\mathit e}^{+}}{{\mathit e}^{-}}$ [1] $147.4$ $\pm0.8$ MeV (S = 2.0)

CHARGED ONLY, ${{\mathit \tau}}$ DECAYS and ${{\mathit e}^{+}}{{\mathit e}^{-}}$ [2] $149.1$ $\pm0.8$ MeV

MIXED CHARGES, OTHER REACTIONS $149.5$ $\pm1.3$ MeV

CHARGED ONLY, HADROPRODUCED $150.2$ $\pm2.4$ MeV

NEUTRAL ONLY, PHOTOPRODUCED $151.5^{+1.9}_{-2.1}$ MeV

NEUTRAL ONLY, OTHER REACTIONS $150.9$ $\pm1.7$ MeV (S = 1.1)

${\Gamma}_{{\mathit \rho}{(770)}^{0}}-{\Gamma}_{{\mathit \rho}{(770)}^{\pm}}$ $0.3$ $\pm1.3$ MeV (S = 1.4)

${\Gamma}_{{\mathit \rho}{(770)}^{+}}-{\Gamma}_{{\mathit \rho}{(770)}^{-}}$ $1.8$ $\pm2.1$

${{\mathit \rho}{(770)}}$ DECAY MODES

Mode   Fraction ($\Gamma_i$ / $\Gamma$) Scale Factor/ Conf. Level P(MeV/c)   $\Gamma_{1}$ ${{\mathit \pi}}{{\mathit \pi}}$ $\sim100$ $\%$ 363   ▸  exp ${{\mathit \rho}{(770)}^{\pm}}$ decays $\Gamma_{2}$ ${{\mathit \pi}^{\pm}}{{\mathit \pi}^{0}}$ $\sim100$ $\%$ 362   $\Gamma_{3}$ ${{\mathit \pi}^{\pm}}{{\mathit \gamma}}$ ($4.5$ $\pm0.5$) $ \times 10^{-4}$ S=2.2  375   $\Gamma_{4}$ ${{\mathit \pi}^{\pm}}{{\mathit \eta}}$ $<6$ $\times 10^{-3}$ CL=84% 152   $\Gamma_{5}$ ${{\mathit \pi}^{\pm}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ $<2.0$ $\times 10^{-3}$ CL=84% 254   ▸  exp ${{\mathit \rho}{(770)}^{0}}$ decays $\Gamma_{6}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ $\sim100$ $\%$ 362   $\Gamma_{7}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$ ($9.9$ $\pm1.6$) $ \times 10^{-3}$ 362   $\Gamma_{8}$ ${{\mathit \pi}^{0}}{{\mathit \gamma}}$ ($4.7$ $\pm0.8$) $ \times 10^{-4}$ S=1.7  376   $\Gamma_{9}$ ${{\mathit \eta}}{{\mathit \gamma}}$ ($3.00$ $\pm0.21$) $ \times 10^{-4}$ 194   $\Gamma_{10}$ ${{\mathit \pi}^{0}}{{\mathit \pi}^{0}}{{\mathit \gamma}}$ ($4.5$ $\pm0.8$) $ \times 10^{-5}$ 363   $\Gamma_{11}$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ [3] [4] ($4.55$ $\pm0.28$) $ \times 10^{-5}$ 373   $\Gamma_{12}$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ [3] [4] ($4.72$ $\pm0.05$) $ \times 10^{-5}$ 388   $\Gamma_{13}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ ($9$ $\pm4$) $ \times 10^{-5}$ 323   $\Gamma_{14}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ ($1.8$ $\pm0.9$) $ \times 10^{-5}$ 251   $\Gamma_{15}$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$ ($1.6$ $\pm0.8$) $ \times 10^{-5}$ 256   $\Gamma_{16}$ ${{\mathit \pi}^{0}}{{\mathit e}^{+}}{{\mathit e}^{-}}$ $<1.2$ $\times 10^{-5}$ CL=90% 376   $\Gamma_{17}$ ${{\mathit \eta}}{{\mathit e}^{+}}{{\mathit e}^{-}}$ 194

[1] As measured in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \rho}^{0}}$. [2] As measured in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ and ${{\mathit \tau}}$ decays. [3] The ${{\mathit e}^{+}}{{\mathit e}^{-}}$ branching fraction is from ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ experiments only. The ${{\mathit \omega}}{{\mathit \rho}}$ interference is then due to ${{\mathit \omega}}{{\mathit \rho}}$ mixing only, and is expected to be small. If ${{\mathit e}}{{\mathit \mu}}$ universality holds, $\Gamma\mathrm {({{\mathit \rho}^{0}} \rightarrow {{\mathit \mu}^{+}} {{\mathit \mu}^{-}})}$ = $\Gamma\mathrm {({{\mathit \rho}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}})}{\times }$ 0.99785. [4] The ${{\mathit \omega}}{{\mathit \rho}}$ interference is then due to ${{\mathit \omega}}{{\mathit \rho}}$ mixing only, and is expected to be small. If ${{\mathit e}}{{\mathit \mu}}$ universality holds, $\Gamma\mathrm {({{\mathit \rho}^{0}} \rightarrow {{\mathit \mu}^{+}} {{\mathit \mu}^{-}})}$ = $\Gamma\mathrm {({{\mathit \rho}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}})}{\times }$ 0.99785.

Constrained Fit information