Search for the process 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:mi>η</mml:mi></mml:mrow></mml:math>

Ачасов, М. Н.; Barnyakov, A.; Beloborodov, K.; Berdyugin, A. V.; Berkaev, D. E.; Богданчиков, А. Г.; Botov, A. A.; Dimova, T.; Голубев, В. Б.; Kardapoltsev, L.; Kasaev, A. S.; Kharlamov, A. G.; Koop, I. A.; Korneev, L.A.; Korol, A. A.; Kovrizhin, D. P.; Koshuba, S. V.; Kupich, A.; Litvinov, Roman; Martin, K. A.; Melnikova, N. A.; Muchnoi, N. Yu.; Obrazovsky, A. E.; Пахтусова, Е. В.; Пугачев, К. В.; Rogovsky, Yu. A.; Senchenko, A. I.; Serednyakov, S. I.; Силагадзе, З. К.; Shatilov, D.; Shatunov, Yu. M.; Shtol, D.; Shwartz, D. B.; Surin, I. K.; Usov, Y.; Vasiljev, A. V.; Zhabin, V. N.; Zhulanov, V.

doi:10.1103/physrevd.98.052007

Cited by 9 publications

(7 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Exclusive bare hadronic cross-section measurements for 32 channels are integrated up to 1.8 GeV over the relevant dispersion kernels. This analysis uses all the available public data with recent additions [9][10][11][12][13][14][15][16][17][18]. References for data already included in our 2017 analysis are provided in the corresponding paper [1] as well as earlier publications [19,20].…”

Section: Input Datamentioning

confidence: 99%

See 1 more Smart Citation

A new evaluation of the hadronic vacuum polarisation contributions to the muon anomalous magnetic moment and to $$\varvec{\alpha }({{\varvec{m}}}_{{\varvec{Z}}}^2)$$

et al. 2020

View full text Add to dashboard Cite

We reevaluate the hadronic vacuum polarisation contributions to the muon magnetic anomaly and to the running of the electromagnetic coupling constant at the Z-boson mass. We include newest e + e − → hadrons cross-section data together with a phenomenological fit of the threshold region in the evaluation of the dispersion integrals. The precision in the individual datasets cannot be fully exploited due to discrepancies that lead to additional systematic uncertainty in particular between BABAR and KLOE data in the dominant π + π − channel. For the muon (g − 2)/2, we find for the lowest-order hadronic contribution (693.9 ± 4.0) · 10 −10 . The full Standard Model prediction differs by 3.3σ from the experimental value. The five-quark hadronic contribution to α(m 2 Z ) is evaluated to be (276.1 ± 1.0) · 10 −4 .

show abstract

Section: Input Datamentioning

confidence: 99%

“…Recent measurements have been included in the data combinations: π 0 γ from SND [14], π + π − 2π 0 from BABAR [10], π + π − 3π 0 from BABAR [15], ηπ + π − from BABAR [13], ηπ + π − π 0 from CMD-3 [9] and SND [17], φη from CMD-3 [18], and K S K L π 0 from SND [11].…”

Section: Other Channelsmentioning

confidence: 99%

A new evaluation of the hadronic vacuum polarisation contributions to the muon anomalous magnetic moment and to $$\varvec{\alpha }({{\varvec{m}}}_{{\varvec{Z}}}^2)$$

et al. 2020

View full text Add to dashboard Cite

show abstract

“…This was then extended to 0.3 ≤ √ s ≤ 2.0 GeV as part of the upgrade to the VEPP-2000 machine. In recent years, SND have released new data for several hadronic modes [32,33], notably the π 0 γ [34,35] cross section and the K + K − cross section above the φ resonance [36]. The SND experiment is also currently analysing a new measurement of the π + π − cross section, having collected an integrated luminosity of 5pb −1 of data for this important final state [37].…”

Section: Sndmentioning

confidence: 99%

The muong−2: a brief overview of hadronic crosssection data

Keshavarzi¹

2020

Proceedings of the 9th International Workshop on Chiral Dynamics — PoS(CD2018)

View full text Add to dashboard Cite

The hadronic vacuum polarisation contributions to the anomalous magnetic moment of the muon, a had,VP µ are evaluated dispersively via a combination of experimentally measured e + e − → hadrons cross section data. Many experiments have dedicated programmes to precisely measure these final states, meaning that a vast amount of data is now available and that, in some cases, overall precision has reached the sub-percent level. However, data tensions are evident between measurements of the same hadronic channels from different experiments, which reduces the overall quality of the data combinations used to determine a had, VP µ . The inclusion of these data in the KNT18 analysis results in a had, LO VP µ = (693.26 ± 2.46) × 10 −10 and a had, NLO VP µ = (−9.82 ± 0.04) × 10 −10 . The corresponding new estimate for the Standard Model prediction is found to be a SM µ = (11 659 182.04 ± 3.56) × 10 −10 , which is 3.7σ below the current experimental measurement.

show abstract

“…No events were found. The upper limit for η → e + e − branching ratio is B(η → e + e − ) < 7 × 10 −7 90% CL [13].…”

Section: Pos(ichep2018)548mentioning

confidence: 90%

Study of the $e^+e^-$ annihilation into hadrons with the SND detector at the VEPP-2000 collider

Shtol¹,

Ачасов²,

Barnyakov³

et al. 2019

Proceedings of the 39th International Conference on High Energy Physics — PoS(ICHEP2018)

View full text Add to dashboard Cite

Recent results on study of exclusive processes of e + e − annihilation into hadrons below 2 GeV obtained at the SND detector are presented. The analysis are based on data collected at the VEPP-2M and VEPP-2000 colliders. In particular, we present the measurements of the e + e − → ηπ + π − , e + e − → ηK + K − , e + e − → K S K L π 0 cross sections, the preliminary results on study of the e + e − → π + π − , e + e − → nn and e + e − → π 0 γ, and the upper limit for η → e + e − decay branching fraction

show abstract

Search for the process e+e−→η

Cited by 9 publications

References 28 publications

A new evaluation of the hadronic vacuum polarisation contributions to the muon anomalous magnetic moment and to $$\varvec{\alpha }({{\varvec{m}}}_{{\varvec{Z}}}^2)$$

A new evaluation of the hadronic vacuum polarisation contributions to the muon anomalous magnetic moment and to $$\varvec{\alpha }({{\varvec{m}}}_{{\varvec{Z}}}^2)$$

The muong−2: a brief overview of hadronic crosssection data

Study of the $e^+e^-$ annihilation into hadrons with the SND detector at the VEPP-2000 collider

Contact Info

Product

Resources

About