Abstract
Measurements of the Cabbibo–Kobayashi–Maskawa matrix elements are important tests of the consistency of the standard model. However, there is some tension in the \(|V_{cb}|\) measurements, depending on the final states used. The \(|V_{cb}|\) has been determined from the measured branching ratios of a B-hadron to final states with c quarks. An independent method of measuring \(|V_{cb}|\) is needed to understand the cause of the discrepancies. We propose a new way of measuring \(|V_{cb}|\) at the LHC. It can be measured from decay of real W bosons \(W\rightarrow c{\bar{b}}\), where the source of the real W bosons is the abundant \(t{\bar{t}}\) sample. By applying b-tagging algorithms on jets from \(W\rightarrow q{\bar{q}}'\), we can measure the fraction of \(W\rightarrow c{\bar{b}}\) present. With approximately \(300\ \mathrm {fb}^{-1}\) of data, the significance is large enough to merit further development of the method.
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References
P.A. Zyla et al. (Particle Data Group), Prog. Theor. Exp. Phys. 2020, 083C01 (2020)
Y. Amhis et al. (Heavy Flavor Averaging Group) (2019) [arXiv :1909.12524]
P.F. Harrison, V.E. Vladimirov, J. High Energy Phys. 01, 191 (2019)
J. Alwall et al., J. High Energy Phys. 07, 079 (2014)
N. Kidonakis, Top-pair and tW production at approximate \(N^3LO\) (2017), arXiv:1709.06975
T. Sjöstrand et al., Comput. Phys. Commun. 191, 159 (2015)
T. Sjöstrand et al., J. High Energy Phys. 05, 026 (2006)
J. de Favereau et al., J. High Energy Phys. 2, 057 (2014)
CMS Collaboration, Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV. https://doi.org/10.1088/1748-0221/13/05/P05011
A.M. Sirunyan et al., CMS Collaboration. Eur. J. Phys. C 78, 891 (2018)
T. Aaltonen et al., CDF Collaboration. Phys. Rev. Lett. 105, 252001 (2010)
Acknowledgements
This work has been supported by the Korean National Research Foundation through grants NRF-2020R1A2B5B02001726 and NRF-2008-00460.
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Choi, S., Kim, B. Measurement of the CKM matrix element \(|V_{cb}|\) from top quark pair events at the LHC. J. Korean Phys. Soc. 78, 1023–1028 (2021). https://doi.org/10.1007/s40042-021-00148-5
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DOI: https://doi.org/10.1007/s40042-021-00148-5