Skip to main content
eScholarship
Open Access Publications from the University of California

Test of lepton flavor universality by the measurement of the B0 →d∗-τ+ντ branching fraction using three-prong τ decays

  • Author(s): Aaij, R
  • Adeva, B
  • Adinolfi, M
  • Ajaltouni, Z
  • Akar, S
  • Albrecht, J
  • Alessio, F
  • Alexander, M
  • Alfonso Albero, A
  • Ali, S
  • Alkhazov, G
  • Alvarez Cartelle, P
  • Alves, AA
  • Amato, S
  • Amerio, S
  • Amhis, Y
  • An, L
  • Anderlini, L
  • Andreassi, G
  • Andreotti, M
  • Andrews, JE
  • Appleby, RB
  • Archilli, F
  • D’argent, P
  • Arnau Romeu, J
  • Artamonov, A
  • Artuso, M
  • Aslanides, E
  • Auriemma, G
  • Baalouch, M
  • Babuschkin, I
  • Bachmann, S
  • Back, JJ
  • Badalov, A
  • Baesso, C
  • Baker, S
  • Balagura, V
  • Baldini, W
  • Baranov, A
  • Barlow, RJ
  • Barschel, C
  • Barsuk, S
  • Barter, W
  • Baryshnikov, F
  • Batozskaya, V
  • Battista, V
  • Bay, A
  • Beaucourt, L
  • Beddow, J
  • Bedeschi, F
  • Bediaga, I
  • Beiter, A
  • Bel, LJ
  • Beliy, N
  • Bellee, V
  • Belloli, N
  • Belous, K
  • Belyaev, I
  • Ben-Haim, E
  • Bencivenni, G
  • Benson, S
  • Beranek, S
  • Berezhnoy, A
  • Bernet, R
  • Berninghoff, D
  • Bertholet, E
  • Bertolin, A
  • Betancourt, C
  • Betti, F
  • Bettler, MO
  • van Beuzekom, M
  • Bezshyiko, I
  • Bifani, S
  • Billoir, P
  • Birnkraut, A
  • Bitadze, A
  • Bizzeti, A
  • Bjørn, M
  • Blake, T
  • Blanc, F
  • Blouw, J
  • Blusk, S
  • Bocci, V
  • Boettcher, T
  • Bondar, A
  • Bondar, N
  • Bonivento, W
  • Bordyuzhin, I
  • Borgheresi, A
  • Borghi, S
  • Borisyak, M
  • Borsato, M
  • Bossu, F
  • Boubdir, M
  • Bowcock, TJV
  • Bowen, E
  • Bozzi, C
  • Braun, S
  • Britton, T
  • Brodzicka, J
  • et al.

Published Web Location

http://doi.org/10.1103/PhysRevD.97.072013
No data is associated with this publication.
Abstract

The ratio of branching fractions R(D∗-)≡B(B0→D∗-τ+ντ)/B(B0→D∗-μ+νμ) is measured using a data sample of proton-proton collisions collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb-1. The τ lepton is reconstructed with three charged pions in the final state. A novel method is used that exploits the different vertex topologies of signal and backgrounds to isolate samples of semitauonic decays of b hadrons with high purity. Using the B0→D∗-π+π-π+ decay as the normalization channel, the ratio B(B0→D∗-τ+ντ)/B(B0→D∗-π+π-π+) is measured to be 1.97±0.13±0.18, where the first uncertainty is statistical and the second systematic. An average of branching fraction measurements for the normalization channel is used to derive B(B0→D∗-τ+ντ)=(1.42±0.094±0.129±0.054)%, where the third uncertainty is due to the limited knowledge of B(B0→D∗-π+π-π+). A test of lepton flavor universality is performed using the well-measured branching fraction B(B0→D∗-μ+νμ) to compute R(D∗-)=0.291±0.019±0.026±0.013, where the third uncertainty originates from the uncertainties on B(B0→D∗-π+π-π+) and B(B0→D∗-μ+νμ). This measurement is in agreement with the Standard Model prediction and with previous measurements.

Item not freely available? Link broken?
Report a problem accessing this item