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

The LHCb Collaboration

doi:10.1007/JHEP08(2017)055

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

The LHCb Collaboration

(Astro)-Particles Physics

Research output: Contribution to Journal › Article › Academic › peer-review

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 language	English
Article number	55
Journal	Journal of High Energy Physics
Volume	2017
Issue number	8
DOIs	https://doi.org/10.1007/JHEP08(2017)055
Publication status	Published - 1 Aug 2017

Funding

Funders	Funder number
Not added	1681016
Horizon 2020 Framework Programme	639068
Science and Technology Facilities Council	ST/N000250/1, ST/H006737/1, ST/N000331/1, GRIDPP, LHCb Upgrades, 1707993, ST/J004332/1, 1641747, ST/K003410/1, 1708182, ST/G005974/1, LHCb, ST/N000234/1
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung	172637, 166208

Keywords

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

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1007/JHEP08(2017)055

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Cite this

@article{ef7a592f1fc848dfb05afdce1b1b7bba,

title = "Test of lepton universality with B 0 → K *0 ℓ + ℓ − decays",

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.].",

keywords = "B physics, Branching fraction, Hadron-Hadron scattering (experiments), Rare decay",

author = "R. Aaij and B. Adeva and Z. Ajaltouni and S. Akar 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{\textquoteright}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 {Carvalho Akiba}, K. and V. Coco and {De Bruyn}, K. and M. Ferro-Luzzi and T. Ketel and {van Leerdam}, J. and M. Merk and Onderwater, {C. J.G.} and G. Raven and M. Schiller and B. Storaci and V. Syropoulos and {van Tilburg}, J. and S. Tolk and P. Tsopelas and N. Tuning and {The LHCb collaboration}, {LHCb collaboration}",

year = "2017",

month = aug,

day = "1",

doi = "10.1007/JHEP08(2017)055",

language = "English",

volume = "2017",

journal = "Journal of High Energy Physics",

issn = "1126-6708",

publisher = "Springer Verlag",

number = "8",

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TY - JOUR

T1 - Test of lepton universality with B 0 → K *0 ℓ + ℓ − decays

AU - Aaij, R.

AU - Adeva, B.

AU - Ajaltouni, Z.

AU - Akar, S.

AU - Alessio, F.

AU - Alexander, M.

AU - Ali, S.

AU - Alkhazov, G.

AU - Alvarez Cartelle, P.

AU - Alves, A. A.

AU - Amato, S.

AU - Amerio, S.

AU - Amhis, Y.

AU - An, L.

AU - Anderlini, L.

AU - Andreassi, G.

AU - Andreotti, M.

AU - Andrews, J. E.

AU - Appleby, R. B.

AU - Archilli, F.

AU - d’Argent, P.

AU - Arnau Romeu, J.

AU - Artamonov, A.

AU - Artuso, M.

AU - Aslanides, E.

AU - Auriemma, G.

AU - Baalouch, M.

AU - Babuschkin, I.

AU - Bachmann, S.

AU - Back, J. J.

AU - Badalov, A.

AU - Baesso, C.

AU - Baker, S.

AU - Balagura, V.

AU - Carvalho Akiba, K.

AU - Coco, V.

AU - De Bruyn, K.

AU - Ferro-Luzzi, M.

AU - Ketel, T.

AU - van Leerdam, J.

AU - Merk, M.

AU - Onderwater, C. J.G.

AU - Raven, G.

AU - Schiller, M.

AU - Storaci, B.

AU - Syropoulos, V.

AU - van Tilburg, J.

AU - Tolk, S.

AU - Tsopelas, P.

AU - Tuning, N.

AU - The LHCb Collaboration

PY - 2017/8/1

Y1 - 2017/8/1

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.].

KW - B physics

KW - Branching fraction

KW - Hadron-Hadron scattering (experiments)

KW - Rare decay

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U2 - 10.1007/JHEP08(2017)055

DO - 10.1007/JHEP08(2017)055

M3 - Article

AN - SCOPUS:85027973382

SN - 1126-6708

VL - 2017

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

IS - 8

M1 - 55

ER -