pdgLive Home   >   LIGHT UNFLAVORED MESONS ($\mathit S$ = $\mathit C$ = $\mathit B$ = 0)   >   ${{\mathit \rho}{(770)}}$   >   NEUTRAL ONLY, ${{\mathit e}^{+}}{{\mathit e}^{-}}$

${{\mathit \rho}{(770)}}$ MASS

We no longer list ${\mathit S}{\mathrm -wave}$ Breit-Wigner fits, or data with high combinatorial background.

NEUTRAL ONLY, ${{\mathit e}^{+}}{{\mathit e}^{-}}$

INSPIRE   PDGID:

M009M0

VALUE (MeV) EVTS DOCUMENT ID TECN  COMMENT $\bf{ 775.26 \pm0.23}$ OUR AVERAGE $775.3$ $\pm0.5$ $\pm0.6$ 1 ACHASOV 2021 SND ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ $775.02$ $\pm0.35$ 2 LEES 2012 G BABR ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$ $775.97$ $\pm0.46$ $\pm0.70$ 900k 3 AKHMETSHIN 2007 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ $774.6$ $\pm0.4$ $\pm0.5$ 800k 4, 5 ACHASOV 2006 SND ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ $775.65$ $\pm0.64$ $\pm0.50$ 114k 6, 7 AKHMETSHIN 2004 CMD2 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ $775.9$ $\pm0.5$ $\pm0.5$ 1.98M 8 ALOISIO 2003 KLOE 1.02 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ $775.8$ $\pm0.9$ $\pm2.0$ 500k 8 ACHASOV 2002 SND 1.02 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ $775.9$ $\pm1.1$ 9 BARKOV 1985 OLYA ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ • • We do not use the following data for averages, fits, limits, etc. • • $763.49$ $\pm0.53$ 10 BARTOS 2017 RVUE ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ $758.23$ $\pm0.46$ 11 BARTOS 2017 A RVUE ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ $775.8$ $\pm0.5$ $\pm0.3$ 1.98M 12 ALOISIO 2003 KLOE 1.02 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ $775.9$ $\pm0.6$ $\pm0.5$ 1.98M 13 ALOISIO 2003 KLOE 1.02 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ $775.0$ $\pm0.6$ $\pm1.1$ 500k 14 ACHASOV 2002 SND 1.02 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ $775.1$ $\pm0.7$ $\pm5.3$ 15 BENAYOUN 1998 RVUE ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ , ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ $770.5$ $\pm1.9$ $\pm5.1$ 16 GARDNER 1998 RVUE $0.28 - 0.92$ ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ $764.1$ $\pm0.7$ 17 O'CONNELL 1997 RVUE ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ $757.5$ $\pm1.5$ 18 BERNICHA 1994 RVUE ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ $768$ $\pm1$ 19 GESHKENBEIN 1989 RVUE ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ 1  From a fit of the cross section in the energy range 0.525 $<$ $\sqrt {s }$ $<$ 0.883 GeV parameterized by the sum of the Breit-Wigner amplitudes for the ${{\mathit \rho}{(770)}}$, ${{\mathit \omega}}$ and ${{\mathit \rho}{(1450)}}$ resonances. 2  Using the GOUNARIS 1968 parametrization with the complex phase of the ${{\mathit \rho}}−{{\mathit \omega}}$ interference and leaving the masses and widths of the ${{\mathit \rho}{(1450)}}$, ${{\mathit \rho}{(1700)}}$, and ${{\mathit \rho}{(2150)}}$ resonances as free parameters of the fit. 3  A combined fit of AKHMETSHIN 2007 , AULCHENKO 2006 , and AULCHENKO 2005 . 4  Supersedes ACHASOV 2005A. 5  A fit of the SND data from 400 to 1000 MeV using parameters of the ${{\mathit \rho}{(1450)}}$ and ${{\mathit \rho}{(1700)}}$ from a fit of the data of BARKOV 1985 , BISELLO 1989 and ANDERSON 2000A. 6  Using the GOUNARIS 1968 parametrization with the complex phase of the ${{\mathit \rho}}-{{\mathit \omega}}$ interference. 7  Update of AKHMETSHIN 2002 . 8  Assuming ${\mathit m}_{{{\mathit \rho}^{+}}}$ = ${\mathit m}_{{{\mathit \rho}^{-}}}$, $\Gamma _{{{\mathit \rho}^{+}}}$ = $\Gamma _{{{\mathit \rho}^{-}}}$. 9  From the GOUNARIS 1968 parametrization of the pion form factor. 10  Applies the Unitary $\&$ Analytic Model of the pion electromagnetic form factor of DUBNICKA 2010 to analyze the data of LEES 2012G and ABLIKIM 2016C. 11  Applies the Unitary $\&$ Analytic Model of the pion electromagnetic form factor of DUBNICKA 2010 to analyze the data of ACHASOV 2006 , AKHMETSHIN 2007 , AUBERT 2009AS, and AMBROSINO 2011A. 12  Assuming ${\mathit m}_{{{\mathit \rho}^{+}}}$ = ${\mathit m}_{{{\mathit \rho}^{-}}}$ = ${\mathit m}_{{{\mathit \rho}^{0}}}$, $\Gamma _{{{\mathit \rho}^{+}}}$ = $\Gamma _{{{\mathit \rho}^{-}}}$ = $\Gamma _{{{\mathit \rho}^{0}}}$. 13  Without limitations on masses and widths. 14  Assuming ${\mathit m}_{{{\mathit \rho}^{0}}}$ = ${\mathit m}_{{{\mathit \rho}^{\pm}}}$, $\mathit g_{ {{\mathit \rho}^{0}} {{\mathit \pi}} {{\mathit \pi}} }$ = $\mathit g_{ {{\mathit \rho}^{\pm}} {{\mathit \pi}} {{\mathit \pi}} }$. 15  Using the data of BARKOV 1985 in the hidden local symmetry model. 16  From the fit to ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ data from the compilations of HEYN 1981 and BARKOV 1985 , including the GOUNARIS 1968 parametrization of the pion form factor. 17  A fit of BARKOV 1985 data assuming the direct ${{\mathit \omega}}{{\mathit \pi}}{{\mathit \pi}}$ coupling. 18  Applying the S-matrix formalism to the BARKOV 1985 data. 19  Includes BARKOV 1985 data. Model-dependent width definition.

References:

ACHASOV 2021 JHEP 2101 113 Measurement of the $e^+e^- \to\pi^+\pi^- $ process cross section with the SND detector at the VEPP-2000 collider in the energy region $0.525<\sqrt{s}<0.883$ GeV BARTOS 2017A IJMP A32 1750154 The Mass and Width Differences of the Neutral and Charged ${{\mathit \rho}{(770)}}$, ${{\mathit \rho}{(1450 )}}$ and ${{\mathit \rho}{(1700)}}$ Mesons from ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ and ${{\mathit \nu}}{{\mathit \tau}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ Processes BARTOS 2017 PR D96 113004 What are the Correct ${{\mathit \rho}{(770)}^{0}}$ Meson Mass and Width Values? LEES 2012G PR D86 032013 Precise Measurement of the ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$( ${{\mathit \gamma}}$) Cross Section with the Initial-State Radiation Method at BABAR AKHMETSHIN 2007 PL B648 28 High-Statistics Measurement of the Pion Form Factor in the ${{\mathit \rho}}$-Meson Energy Range with the CMD-2 Detector ACHASOV 2006 JETP 103 380 Update of the ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ ${{\mathit \pi}^{+}}$ ${{\mathit \pi}^{-}}$ Cross-Section Measured by SND Detector in the Energy Region 400 < $\sqrt {s }$ < 1000 MeV AKHMETSHIN 2004 PL B578 285 Reanalysis of Hadronic Cross Section Measurements at CMD-2 ALOISIO 2003 PL B561 55 Study of the Decay ${{\mathit \phi}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ with the Detector ACHASOV 2002 PR D65 032002 Study of the ${{\mathit \pi}}{{\mathit \pi}}$ Mass Spectra in the Process ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{0}}$ at $\sqrt {s }$ = 1020 MeV BENAYOUN 1998 EPJ C2 269 New Results in ${{\mathit \rho}^{0}}$ Meson Physics GARDNER 1998 PR D57 2716 ${{\mathit \rho}}$ $\leftrightarrow$ ${{\mathit \omega}}$ Mixing and the Pion Formfactor in the Timelike Region Also PR D62 019903 (errat.) Erratum: GARDNER 1998 ${{\mathit \rho}}$ $\leftrightarrow$ ${{\mathit \omega}}$ Mixing and the Pion Form Factor in the Timelike Region O'CONNELL 1997 NP A623 559 Extracting the ${{\mathit \rho}}$ $\leftrightarrow$ ${{\mathit \omega}}$ Mixing Amplitude from the Pion Formfactor BERNICHA 1994 PR D50 4454 Mass and Width of the ${{\mathit \rho}^{0}}$ from an S Matrix Approach to ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ GESHKENBEIN 1989 ZPHY C45 351 Analysis of Experiments on Measurement of the Pion Electromagnetic Formfactor BARKOV 1985 NP B256 365 Electromagnetic Pion Form Factor in the Timelike Region

Except where otherwise noted, content of the 2023 Review of Particle Physics is licensed under a Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license. The publication of the Review of Particle Physics is supported by US DOE, MEXT (Japan), INFN (Italy), JPS and CERN. Individual collaborators receive support for their PDG activities from their respective institutes or funding agencies. © 2023. See LBNL disclaimers.