Test of lepton flavor universality and search for lepton flavor violation in B → Kℓℓ decays

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Test of lepton flavor universality and search for lepton flavor violation in B → Kℓℓ decays. / The BELLE collaboration; Габышев, Николай Иванович; Гармаш, Алексей Юрьевич et al.

In: Journal of High Energy Physics, Vol. 2021, No. 3, 105, 03.2021.

Research output: Contribution to journal › Article › peer-review

Author

The BELLE collaboration ; Габышев, Николай Иванович ; Гармаш, Алексей Юрьевич et al. / Test of lepton flavor universality and search for lepton flavor violation in B → Kℓℓ decays. In: Journal of High Energy Physics. 2021 ; Vol. 2021, No. 3.

BibTeX

@article{b2f4aca40bd14d619b18f6034419e6f7,

title = "Test of lepton flavor universality and search for lepton flavor violation in B → Kℓℓ decays",

abstract = "We present measurements of the branching fractions for the decays B → Kμ+μ− and B → Ke+e−, and their ratio (RK), using a data sample of 711 fb−1 that contains 772 × 106BB¯ events. The data were collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. The ratio RK is measured in five bins of dilepton invariant-mass-squared (q2): q2 ∈ (0.1, 4.0), (4.00, 8.12), (1.0, 6.0), (10.2, 12.8) and (> 14.18) GeV2/c4, along with the whole q2 region. The RK value for q2 ∈ (1.0, 6.0) GeV2/c4 is 1.03−0.24+0.28 ± 0.01. The first and second uncertainties listed are statistical and systematic, respectively. All results for RK are consistent with Standard Model predictions. We also measure CP-averaged isospin asymmetries in the same q2 bins. The results are consistent with a null asymmetry, with the largest difference of 2.6 standard deviations occurring for the q2 ∈ (1.0, 6.0) GeV2/c4 bin in the mode with muon final states. The measured differential branching fractions, dℬ /dq2, are consistent with theoretical predictions for charged B decays, while the corresponding values are below the expectations for neutral B decays. We have also searched for lepton-flavor-violating B → Kμ±e∓ decays and set 90% confidence-level upper limits on the branching fraction in the range of 10−8 for B+ → K+μ±e∓, and B0 → K0μ±e∓ modes.",

keywords = "B physics, e-e Experiments, FCNC Interaction, Flavor physics, Flavour Changing Neutral Currents",

author = "{The BELLE collaboration} and S. Choudhury and S. Sandilya and K. Trabelsi and A. Giri and H. Aihara and {Al Said}, S. and Asner, {D. M.} and H. Atmacan and V. Aulchenko and T. Aushev and R. Ayad and V. Babu and S. Bahinipati and P. Behera and C. Bele{\~n}o and K. Belous and J. Bennett and F. Bernlochner and M. Bessner and V. Bhardwaj and T. Bilka and J. Biswal and G. Bonvicini and A. Bozek and M. Bra{\v c}ko and Browder, {T. E.} and M. Campajola and D. {\v C}ervenkov and Chang, {M. C.} and P. Chang and V. Chekelian and A. Chen and Cheon, {B. G.} and K. Chilikin and K. Cho and Choi, {S. K.} and Y. Choi and D. Cinabro and S. Cunliffe and N. Dash and {De Nardo}, G. and R. Dhamija and {Di Capua}, F. and J. Dingfelder and S. Eidelman and D. Epifanov and Габышев, {Николай Иванович} and Гармаш, {Алексей Юрьевич} and P. Krokovny and Кузьмин, {Александр Степанович} and D. Matvienko and A. Vinokurova and V. Vorobyev and Жилич, {Виктор Николаевич}",

year = "2021",

month = mar,

doi = "10.1007/JHEP03(2021)105",

language = "English",

volume = "2021",

journal = "Journal of High Energy Physics",

issn = "1029-8479",

publisher = "Springer US",

number = "3",

}

RIS

TY - JOUR

T1 - Test of lepton flavor universality and search for lepton flavor violation in B → Kℓℓ decays

AU - The BELLE collaboration

AU - Choudhury, S.

AU - Sandilya, S.

AU - Trabelsi, K.

AU - Giri, A.

AU - Aihara, H.

AU - Al Said, S.

AU - Asner, D. M.

AU - Atmacan, H.

AU - Aulchenko, V.

AU - Aushev, T.

AU - Ayad, R.

AU - Babu, V.

AU - Bahinipati, S.

AU - Behera, P.

AU - Beleño, C.

AU - Belous, K.

AU - Bennett, J.

AU - Bernlochner, F.

AU - Bessner, M.

AU - Bhardwaj, V.

AU - Bilka, T.

AU - Biswal, J.

AU - Bonvicini, G.

AU - Bozek, A.

AU - Bračko, M.

AU - Browder, T. E.

AU - Campajola, M.

AU - Červenkov, D.

AU - Chang, M. C.

AU - Chang, P.

AU - Chekelian, V.

AU - Chen, A.

AU - Cheon, B. G.

AU - Chilikin, K.

AU - Cho, K.

AU - Choi, S. K.

AU - Choi, Y.

AU - Cinabro, D.

AU - Cunliffe, S.

AU - Dash, N.

AU - De Nardo, G.

AU - Dhamija, R.

AU - Di Capua, F.

AU - Dingfelder, J.

AU - Eidelman, S.

AU - Epifanov, D.

AU - Габышев, Николай Иванович

AU - Гармаш, Алексей Юрьевич

AU - Krokovny, P.

AU - Кузьмин, Александр Степанович

AU - Matvienko, D.

AU - Vinokurova, A.

AU - Vorobyev, V.

AU - Жилич, Виктор Николаевич

PY - 2021/3

Y1 - 2021/3

N2 - We present measurements of the branching fractions for the decays B → Kμ+μ− and B → Ke+e−, and their ratio (RK), using a data sample of 711 fb−1 that contains 772 × 106BB¯ events. The data were collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. The ratio RK is measured in five bins of dilepton invariant-mass-squared (q2): q2 ∈ (0.1, 4.0), (4.00, 8.12), (1.0, 6.0), (10.2, 12.8) and (> 14.18) GeV2/c4, along with the whole q2 region. The RK value for q2 ∈ (1.0, 6.0) GeV2/c4 is 1.03−0.24+0.28 ± 0.01. The first and second uncertainties listed are statistical and systematic, respectively. All results for RK are consistent with Standard Model predictions. We also measure CP-averaged isospin asymmetries in the same q2 bins. The results are consistent with a null asymmetry, with the largest difference of 2.6 standard deviations occurring for the q2 ∈ (1.0, 6.0) GeV2/c4 bin in the mode with muon final states. The measured differential branching fractions, dℬ /dq2, are consistent with theoretical predictions for charged B decays, while the corresponding values are below the expectations for neutral B decays. We have also searched for lepton-flavor-violating B → Kμ±e∓ decays and set 90% confidence-level upper limits on the branching fraction in the range of 10−8 for B+ → K+μ±e∓, and B0 → K0μ±e∓ modes.

AB - We present measurements of the branching fractions for the decays B → Kμ+μ− and B → Ke+e−, and their ratio (RK), using a data sample of 711 fb−1 that contains 772 × 106BB¯ events. The data were collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. The ratio RK is measured in five bins of dilepton invariant-mass-squared (q2): q2 ∈ (0.1, 4.0), (4.00, 8.12), (1.0, 6.0), (10.2, 12.8) and (> 14.18) GeV2/c4, along with the whole q2 region. The RK value for q2 ∈ (1.0, 6.0) GeV2/c4 is 1.03−0.24+0.28 ± 0.01. The first and second uncertainties listed are statistical and systematic, respectively. All results for RK are consistent with Standard Model predictions. We also measure CP-averaged isospin asymmetries in the same q2 bins. The results are consistent with a null asymmetry, with the largest difference of 2.6 standard deviations occurring for the q2 ∈ (1.0, 6.0) GeV2/c4 bin in the mode with muon final states. The measured differential branching fractions, dℬ /dq2, are consistent with theoretical predictions for charged B decays, while the corresponding values are below the expectations for neutral B decays. We have also searched for lepton-flavor-violating B → Kμ±e∓ decays and set 90% confidence-level upper limits on the branching fraction in the range of 10−8 for B+ → K+μ±e∓, and B0 → K0μ±e∓ modes.

KW - B physics

KW - e-e Experiments

KW - FCNC Interaction

KW - Flavor physics

KW - Flavour Changing Neutral Currents

UR - http://www.scopus.com/inward/record.url?scp=85102586238&partnerID=8YFLogxK

U2 - 10.1007/JHEP03(2021)105

DO - 10.1007/JHEP03(2021)105

M3 - Article

AN - SCOPUS:85102586238

VL - 2021

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

SN - 1029-8479

IS - 3

M1 - 105

ER -

ID: 28080531