Test of lepton flavor universality in semileptonic <math display="inline"><msubsup><mi>B</mi><mi>c</mi><mo>+</mo></msubsup></math> meson decays in proton-proton collisions at <math display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>

Benecke, Anna;Bethani, Agni;Bruno, Giacomo;Caputo, Claudio;CMS;et.al.
(2025) Physical review D — Vol. 111 (2025)

Files

8e659c9465920d61ae9f1714d0fdc259.pdf
  • Open Access
  • Adobe PDF
  • 463.2 KB
Download

Details

Authors
Show more
Abstract
A measurement of the ratio of branching fractions <math display="inline"><mi>R</mi><mo stretchy="false">(</mo><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow><mo stretchy="false">)</mo><mo>=</mo><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mi>B</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow><msup><mi>τ</mi><mo>+</mo></msup><msub><mi>ν</mi><mi>τ</mi></msub><mo stretchy="false">)</mo><mo>/</mo><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mi>B</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow><msup><mi>μ</mi><mo>+</mo></msup><msub><mi>ν</mi><mi>μ</mi></msub><mo stretchy="false">)</mo></math> in the <math display="inline"><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow><mo stretchy="false">→</mo><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>-</mo></msup></math>, <math display="inline"><mrow><msup><mrow><mi>τ</mi></mrow><mrow><mo>+</mo></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup><msub><mrow><mi>ν</mi></mrow><mrow><mi>μ</mi></mrow></msub><msub><mrow><mover accent="true"><mrow><mi>ν</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mi>τ</mi></mrow></msub></mrow></math> decay channel is presented. This measurement uses a sample of proton-proton collision data collected at a center-of-mass energy of <math display="inline"><mrow><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math> by the CMS experiment in 2018, corresponding to an integrated luminosity of <math display="inline"><mn>59.7</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>-</mo><mn>1</mn></mrow></msup></math>. The measured ratio, <math display="inline"><mi>R</mi><mo stretchy="false">(</mo><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow><mo stretchy="false">)</mo><mo>=</mo><mspace linebreak="goodbreak"/><mn>0.1</mn><msubsup><mn>7</mn><mrow><mo>-</mo><mn>0.17</mn></mrow><mrow><mo>+</mo><mn>0.18</mn></mrow></msubsup><msubsup><mrow><mrow><mo stretchy="false">(</mo><mi>stat</mi><mo stretchy="false">)</mo></mrow></mrow><mrow><mo>-</mo><mn>0.22</mn></mrow><mrow><mo>+</mo><mn>0.21</mn></mrow></msubsup><msubsup><mrow><mrow><mo stretchy="false">(</mo><mi>syst</mi><mo stretchy="false">)</mo></mrow></mrow><mrow><mo>-</mo><mn>0.18</mn></mrow><mrow><mo>+</mo><mn>0.19</mn></mrow></msubsup><mrow><mrow><mo stretchy="false">(</mo><mi>theo</mi><mo stretchy="false">)</mo></mrow></mrow><mo>=</mo><mn>0.17</mn><mo>±</mo><mn>0.33</mn></math>, agrees with the value of <math display="inline"><mn>0.2582</mn><mo>±</mo><mn>0.0038</mn></math> predicted by the standard model, which assumes lepton flavor universality. By testing lepton flavor universality, this measurement is a probe of new physics using <math display="inline"><msubsup><mi>B</mi><mi>c</mi><mo>+</mo></msubsup></math> mesons, which are currently only produced at the LHC.
Affiliations

Citations

  • APA
  • Chicago
  • FWB

Benecke, A., Bethani, A., Bruno, G., Caputo, C., Delaere, C., Donertas, I. S., Giammanco, A., Jain, S., Jain, S., Lemaitre, V., Lidrych, J., Mastrapasqua, P., Tran, T. T., Wertz, S., CMS, & et al. (2025). Test of lepton flavor universality in semileptonic <math display=“inline”><msubsup><mi>B</mi><mi>c</mi><mo>+</mo></msubsup></math> meson decays in proton-proton collisions at <math display=“inline”><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>. Physical review D, 111. https://doi.org/10.1103/PhysRevD.111.L051102 (Original work published 2025)