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. For the first time, R(D∗-) is determined using the τ-lepton decays with three charged pions in the final state. The B0→D∗-τ+ντ yield is normalized to that of the B0→D∗-π+π-π+ mode, providing a measurement of B(B0→D∗-τ+ντ)/B(B0→D∗-π+π-π+)=1.97±0.13±0.18, where the first uncertainty is statistical and the second systematic. The value of B(B0→D∗-τ+ντ)=(1.42±0.094±0.129±0.054)% is obtained, where the third uncertainty is due to the limited knowledge of the branching fraction of the normalization mode. Using the well-measured branching fraction of the B0→D∗-μ+νμ decay, a value of R(D∗-)=0.291±0.019±0.026±0.013 is established, where the third uncertainty is due to the limited knowledge of the branching fractions of the normalization and B0→D∗-μ+νμ modes. This measurement is in agreement with the standard model prediction and with previous results.

Measurement of the Ratio of the B0 →d∗-τ+ντ and B0 →d∗-μ+νμ Branching Fractions Using Three-Prong τ -Lepton Decays / 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, A.A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Andreassi, G., Andreotti, M., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 120:17(2018), p. 171802. [10.1103/PhysRevLett.120.171802]

Measurement of the Ratio of the B0 →d∗-τ+ντ and B0 →d∗-μ+νμ Branching Fractions Using Three-Prong τ -Lepton Decays

Capriotti L.;Casse G.;Sarti A.;Sciubba A.;
2018

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. For the first time, R(D∗-) is determined using the τ-lepton decays with three charged pions in the final state. The B0→D∗-τ+ντ yield is normalized to that of the B0→D∗-π+π-π+ mode, providing a measurement of B(B0→D∗-τ+ντ)/B(B0→D∗-π+π-π+)=1.97±0.13±0.18, where the first uncertainty is statistical and the second systematic. The value of B(B0→D∗-τ+ντ)=(1.42±0.094±0.129±0.054)% is obtained, where the third uncertainty is due to the limited knowledge of the branching fraction of the normalization mode. Using the well-measured branching fraction of the B0→D∗-μ+νμ decay, a value of R(D∗-)=0.291±0.019±0.026±0.013 is established, where the third uncertainty is due to the limited knowledge of the branching fractions of the normalization and B0→D∗-μ+νμ modes. This measurement is in agreement with the standard model prediction and with previous results.
2018
Branching fraction, Hadron-Hadron scattering (experiments), QCD
01 Pubblicazione su rivista::01a Articolo in rivista
Measurement of the Ratio of the B0 →d∗-τ+ντ and B0 →d∗-μ+νμ Branching Fractions Using Three-Prong τ -Lepton Decays / 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, A.A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Andreassi, G., Andreotti, M., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 120:17(2018), p. 171802. [10.1103/PhysRevLett.120.171802]
File allegati a questo prodotto
File Dimensione Formato  
PhysRevLett.120.171802.pdf

accesso aperto

Tipologia: Versione editoriale (versione pubblicata con il layout dell'editore)
Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 547.83 kB
Formato Adobe PDF
547.83 kB Adobe PDF

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1310921
Citazioni
  • ???jsp.display-item.citation.pmc??? 3
  • Scopus 402
  • ???jsp.display-item.citation.isi??? 252
social impact