Test of lepton universality with B 0 → K *0+ decays

The LHCb collaboration

Research output: Contribution to journalArticle

244 Citations (Scopus)

Abstract

A test of lepton universality, performed by measuring the ratio of the branching fractions of the B0 → K*0μ+μ and B0 → K*0e+e decays, RK*0, is presented. The K*0 meson is reconstructed in the final state K+π, which is required to have an invariant mass within 100 MeV/c2 of the known K*(892)0 mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of about 3 fb−1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The ratio is measured in two regions of the dilepton invariant mass squared, q2, to be (Formula presented.) The corresponding 95.4% confidence level intervals are [0.52, 0.89] and [0.53, 0.94]. The results, which represent the most precise measurements of RK*0 to date, are compatible with the Standard Model expectations at the level of 2.1–2.3 and 2.4–2.5 standard deviations in the two q2 regions, respectively.[Figure not available: see fulltext.].

Original languageEnglish
Article number55
JournalJournal of High Energy Physics
Volume2017
Issue number8
DOIs
Publication statusPublished - 1 Aug 2017

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leptons
decay
protons
center of mass
confidence
standard deviation
mesons
luminosity
intervals
collisions
energy

Keywords

  • B physics
  • Branching fraction
  • Hadron-Hadron scattering (experiments)
  • Rare decay

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Cite this

Test of lepton universality with B 0 → K *0+ decays. / The LHCb collaboration.

In: Journal of High Energy Physics, Vol. 2017, No. 8, 55, 01.08.2017.

Research output: Contribution to journalArticle

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abstract = "A test of lepton universality, performed by measuring the ratio of the branching fractions of the B0 → K*0μ+μ− and B0 → K*0e+e− decays, RK*0, is presented. The K*0 meson is reconstructed in the final state K+π−, which is required to have an invariant mass within 100 MeV/c2 of the known K*(892)0 mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of about 3 fb−1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The ratio is measured in two regions of the dilepton invariant mass squared, q2, to be (Formula presented.) The corresponding 95.4{\%} confidence level intervals are [0.52, 0.89] and [0.53, 0.94]. The results, which represent the most precise measurements of RK*0 to date, are compatible with the Standard Model expectations at the level of 2.1–2.3 and 2.4–2.5 standard deviations in the two q2 regions, respectively.[Figure not available: see fulltext.].",
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author = "{The LHCb collaboration}, {LHCb collaboration} and R. Aaij and B. Adeva and M. Adinolfi and Z. Ajaltouni and S. Akar and J. Albrecht and F. Alessio and M. Alexander and S. Ali and G. Alkhazov and {Alvarez Cartelle}, P. and Alves, {A. A.} and S. Amato and S. Amerio and Y. Amhis and L. An and L. Anderlini and G. Andreassi and M. Andreotti and Andrews, {J. E.} and Appleby, {R. B.} and F. Archilli and P. d’Argent and {Arnau Romeu}, J. and A. Artamonov and M. Artuso and E. Aslanides and G. Auriemma and M. Baalouch and I. Babuschkin and S. Bachmann and Back, {J. J.} and A. Badalov and C. Baesso and S. Baker and V. Balagura and W. Baldini and A. Baranov and Barlow, {R. J.} and C. Barschel and S. Barsuk and W. Barter and F. Baryshnikov and M. Baszczyk and V. Batozskaya and V. Battista and A. Bay and L. Beaucourt and A. Petrov and A. Vagner",
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N2 - A test of lepton universality, performed by measuring the ratio of the branching fractions of the B0 → K*0μ+μ− and B0 → K*0e+e− decays, RK*0, is presented. The K*0 meson is reconstructed in the final state K+π−, which is required to have an invariant mass within 100 MeV/c2 of the known K*(892)0 mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of about 3 fb−1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The ratio is measured in two regions of the dilepton invariant mass squared, q2, to be (Formula presented.) The corresponding 95.4% confidence level intervals are [0.52, 0.89] and [0.53, 0.94]. The results, which represent the most precise measurements of RK*0 to date, are compatible with the Standard Model expectations at the level of 2.1–2.3 and 2.4–2.5 standard deviations in the two q2 regions, respectively.[Figure not available: see fulltext.].

AB - A test of lepton universality, performed by measuring the ratio of the branching fractions of the B0 → K*0μ+μ− and B0 → K*0e+e− decays, RK*0, is presented. The K*0 meson is reconstructed in the final state K+π−, which is required to have an invariant mass within 100 MeV/c2 of the known K*(892)0 mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of about 3 fb−1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The ratio is measured in two regions of the dilepton invariant mass squared, q2, to be (Formula presented.) The corresponding 95.4% confidence level intervals are [0.52, 0.89] and [0.53, 0.94]. The results, which represent the most precise measurements of RK*0 to date, are compatible with the Standard Model expectations at the level of 2.1–2.3 and 2.4–2.5 standard deviations in the two q2 regions, respectively.[Figure not available: see fulltext.].

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