An angular analysis of the Bs0→ ϕe+e− decay is performed using the proton-proton collision dataset collected between 2011 and 2018 by the LHCb experiment, corresponding to an integrated luminosity of 9 fb−1 at centre-of-mass energies of 7, 8 and 13 TeV. The analysis is performed in the very low dielectron invariant mass-squared region between 0.0009 and 0.2615 GeV2/c4. The longitudinal polarisation fraction of the ϕ meson is measured to be less than 11.5% at 90% confidence level. The ATReCP observable, which is related to the lepton forward-backward asymmetry, is measured to be 0.116 ± 0.155 ± 0.006, where the first uncertainty is statistical and the second systematic. The transverse asymmetries, AT2 and ATImCP, which are sensitive to the virtual photon polarisation, are found to be −0.045 ± 0.235 ± 0.014 and 0.002 ± 0.247 ± 0.016, respectively. The results are consistent with Standard Model predictions.

Constraints on the photon polarisation in b → sγ transitions using Bs0→ ϕe+e− decays

Argenton M.;Bolzonella R.;Calabrese R.;Capriotti L.;Cavallini V.;Couturier B.;Fiorini M.;Franzoso E.;Guarise M.;Kotriakhova S.;Luppi E.;Okamura S.;Pappalardo L. L.;Passalacqua B.;Romolini G.;Tomassetti L.;
2025

Abstract

An angular analysis of the Bs0→ ϕe+e− decay is performed using the proton-proton collision dataset collected between 2011 and 2018 by the LHCb experiment, corresponding to an integrated luminosity of 9 fb−1 at centre-of-mass energies of 7, 8 and 13 TeV. The analysis is performed in the very low dielectron invariant mass-squared region between 0.0009 and 0.2615 GeV2/c4. The longitudinal polarisation fraction of the ϕ meson is measured to be less than 11.5% at 90% confidence level. The ATReCP observable, which is related to the lepton forward-backward asymmetry, is measured to be 0.116 ± 0.155 ± 0.006, where the first uncertainty is statistical and the second systematic. The transverse asymmetries, AT2 and ATImCP, which are sensitive to the virtual photon polarisation, are found to be −0.045 ± 0.235 ± 0.014 and 0.002 ± 0.247 ± 0.016, respectively. The results are consistent with Standard Model predictions.
2025
Aaij, R.; Abdelmotteleb, A. S. W.; Abellan Beteta, C.; Abudinen, F.; Ackernley, T.; Adefisoye, A. A.; Adeva, B.; Adinolfi, M.; Adlarson, P.; Agapopoul...espandi
File in questo prodotto:
File Dimensione Formato  
JHEP03(2025)047.pdf

accesso aperto

Descrizione: versione editoriale
Tipologia: Full text (versione editoriale)
Licenza: Creative commons
Dimensione 1.26 MB
Formato Adobe PDF
1.26 MB Adobe PDF Visualizza/Apri

I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11392/2592951
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 3
  • ???jsp.display-item.citation.isi??? ND
social impact