Anomalies in B Decays: A Sign of New
Physics?
David London
Abstract At the present time, there are a number of measurements of B-decay
observables that disagree with the predictions of the standard model. These discrepancies have been seen in processes governed by two types of decay: (1) b → sμ + μ −
and (2) b → cτ − ¯
ν. In this talk, I review the experimental results, as well as the
proposed new-physics explanations. We may be seeing the first signs of physics
beyond the standard model.
Keywords Anomalies in B decays · New physics
1 Introduction
The development of the standard model (SM) in particle physics is one of the great
triumphs in all of physics. The SM has made a great many predictions, almost all of
which have been verified, including the existence of the Higgs boson. There is no
question that the SM is correct.
However, there are many reasons to believe it is not complete, such as the
large number of arbitrary parameters, the hierarchy problem, the matter-antimatter
asymmetry in the universe, dark matter, etc. In order to address these issues, there
must be physics beyond the SM. We do not know what the new physics (NP) is, nor
where it is, so we have to search for it in all possible ways:
• Direct searches: in high-energy experiments, one task is to look for the production of new particles. Unfortunately, to date, such searches have revealed nothing.
No SUSY, no direct dark matter detection, no new particles.
• Indirect searches: here the idea is to look for virtual effects of new particles. This
method has been more promising.
D. London ()
Physique des Particules, Université de Montréal, Montréal, QC, Canada
e-mail: london@lps.umontreal.ca
© Springer Nature Switzerland AG 2021
M. B. Paranjape et al. (eds.), Quantum Theory and Symmetries, CRM Series in
Mathematical Physics, https://doi.org/10.1007/978-3-030-55777-5_54
577
Physics?
David London
Abstract At the present time, there are a number of measurements of B-decay
observables that disagree with the predictions of the standard model. These discrepancies have been seen in processes governed by two types of decay: (1) b → sμ + μ −
and (2) b → cτ − ¯
ν. In this talk, I review the experimental results, as well as the
proposed new-physics explanations. We may be seeing the first signs of physics
beyond the standard model.
Keywords Anomalies in B decays · New physics
1 Introduction
The development of the standard model (SM) in particle physics is one of the great
triumphs in all of physics. The SM has made a great many predictions, almost all of
which have been verified, including the existence of the Higgs boson. There is no
question that the SM is correct.
However, there are many reasons to believe it is not complete, such as the
large number of arbitrary parameters, the hierarchy problem, the matter-antimatter
asymmetry in the universe, dark matter, etc. In order to address these issues, there
must be physics beyond the SM. We do not know what the new physics (NP) is, nor
where it is, so we have to search for it in all possible ways:
• Direct searches: in high-energy experiments, one task is to look for the production of new particles. Unfortunately, to date, such searches have revealed nothing.
No SUSY, no direct dark matter detection, no new particles.
• Indirect searches: here the idea is to look for virtual effects of new particles. This
method has been more promising.
D. London ()
Physique des Particules, Université de Montréal, Montréal, QC, Canada
e-mail: london@lps.umontreal.ca
© Springer Nature Switzerland AG 2021
M. B. Paranjape et al. (eds.), Quantum Theory and Symmetries, CRM Series in
Mathematical Physics, https://doi.org/10.1007/978-3-030-55777-5_54
577