The Exclusive Vision of Rare $K$ and $B$ Decays and of the Quark Mixing in the Standard Model

Buras, Andrzej J.; Venturini, Elena

doi:10.48550/arxiv.2203.11960

Cited by 8 publications

(106 citation statements)

References 37 publications

(79 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The central values of |V td | and |V ts | exposed here are chosen to make the overall factors in these formulae to be equal to the experimental values of the two observables. The reference values for BB d F B d and BBs F Bs are those from the HPQCD collaboration [24] as used by us already in [11]. Correspondingly also the resulting reference values for |V td | and |V ts | agree perfectly with those quoted in [24].…”

Section: Basic Formulaesupporting

confidence: 64%

“…This strategy has already been explored in [21] where ε K , ∆M d and ∆M s and S ψK S have been considered. This was also the case of the analyses in [10,11].…”

Section: Introductionmentioning

confidence: 55%

“…• They exhibit the action of ∆M s and of B s decays together with other processes. In particular the recently found anomaly in B s → µ + µ − decay [11,17] can be exhibited in this manner which is not possible in a UT-plot.…”

Section: Introductionmentioning

confidence: 90%

“…As the removal of the |V cb | obstacle could still take some years before the experts agree on a unique value of this parameter, it is time to develop a new strategy for the coming years. In fact the |V cb | − γ plots proposed recently in collaboration with Elena Venturini in [10,11,16] appear to be superior to the usual UT plots in this context in three ways:…”

Section: Introductionmentioning

confidence: 91%

“…It appears then that the |V cb | − γ plots for ∆M s , ∆M d and ε K presented in [10,11] are more useful in this context than the usual UT plots that exhibit the impact of quark mixing and rare decays in the (¯ , η) plane [18,19] 3 . The goal of the present paper is to demonstrate the usefulness of |V cb | − γ plots also for…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

On the Superiority of the $|V_{cb}|-γ$ Plots over the Unitarity Triangle Plots in the 2020s

Buras

2022

Preprint

Self Cite

View full text Add to dashboard Cite

The Unitarity Triangle (UT) plots played already for three decades an important role in the tests of the Standard Model (SM) and the determination of the CKM parameters. As of 2022, among the four CKM parameters, |V us | and β are already measured with respectable precision, while this is not the case of |V cb | and γ. In the case of |V cb | the main obstacle are the significant tensions between its inclusive and exclusive determinations from tree-level decays and it could still take some years before a unique value of this parameter will be known. The present uncertainty in γ of 4 • from tree-level decays will be reduced to 1 • by the LHCb and Belle II collaborations in the coming years. Unfortunately in the common UT plots |V cb | is not seen and the experimental improvements in the determination of γ from tree-level decays at the level of a few degrees are difficult to appreciate. In view of these deficiencies of the UT plots with respect to |V cb | and γ and the central role these two CKM parameters will play in this decade, the recently proposed plots of |V cb | versus γ extracted from various processes appear to be superior to the UT plots in the flavour phenomenology of the 2020s. We illustrate this idea with ∆F = 2 observables ∆M s , ∆M d , ε K and with rare decaysIn particular the power of ε K , B(K + → π + ν ν) and B(K L → π 0 ν ν) in the determination of |V cb |, due to their strong dependence on |V cb |, is transparently exhibited in this manner. Combined with future reduced errors on γ and |V cb | from tree-level decays such plots can better exhibit possible inconsistencies between various determinations of these two parameters, caused by new physics, than it is possible with the UT plots. This can already be illustrated on the example of the recently found 2.7σ anomaly in B s → µ + µ − .

show abstract

Section: Basic Formulaesupporting

confidence: 64%

“…This strategy has already been explored in [21] where ε K , ∆M d and ∆M s and S ψK S have been considered. This was also the case of the analyses in [10,11].…”

Section: Introductionmentioning

confidence: 55%

Section: Introductionmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

On the Superiority of the $|V_{cb}|-γ$ Plots over the Unitarity Triangle Plots in the 2020s

Buras

2022

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

Chiral perturbation theory: reflections on effective theories of the standard model

2023

View full text Add to dashboard Cite

The pseudoscalar particles pions, kaons and the g-particle are considerably lighter than the other hadrons such as protons or neutrons. Their lightness was understood as a consequence of approximate chiral symmetry breaking. This led to current algebra, a way to express the relations imposed by the symmetry breaking. It was realized by Weinberg that because of their low mass, it is possible to formulate a purely pionic (effective) field theory at experimental energies, which carries all information on the (non-perturbative) dynamics, symmetries, and their spontaneous breaking of quantum chromodynamics (QCD) and allows for systematic calculations of observables. In this review, we trace these developments and present recent activities in this field. We make the connection to other effective theories, more generally introduced by Wilson, as approximate field theories at low energies. Indeed, principles and paradigms introduced first for pions have become ubiquitous in particle physics and the standard model. Lastly, we turn to the latest development where the present (fundamental) standard model itself is considered as an effective field theory of a-yet to be formulated-even more fundamental theory. We also discuss important techniques that were developed in order to turn chiral perturbation theory into a predictive framework and briefly review some connections between lattice QCD and chiral perturbation theory (ChPT).

show abstract

On the superiority of the $$|V_{cb}|-\gamma $$ plots over the unitarity triangle plots in the 2020s

Buras

2022

Eur. Phys. J. C

Self Cite

View full text Add to dashboard Cite

The unitarity triangle (UT) plots played already for three decades an important role in the tests of the Standard Model (SM) and the determination of the CKM parameters. As of 2022, among the four CKM parameters, $$|V_{us}|$$ | V us | and $$\beta $$ β are already measured with respectable precision, while this is not the case of $$|V_{cb}|$$ | V cb | and $$\gamma $$ γ . In the case of $$|V_{cb}|$$ | V cb | the main obstacle are the significant tensions between its inclusive and exclusive determinations from tree-level decays and it could still take some years before a unique value of this parameter will be known. The present uncertainty in $$\gamma $$ γ of $$4^\circ $$ 4 ∘ from tree-level decays will be reduced to $$1^\circ $$ 1 ∘ by the LHCb and Belle II collaborations in the coming years. Unfortunately in the common UT plots $$|V_{cb}|$$ | V cb | is not seen and the experimental improvements in the determination of $$\gamma $$ γ from tree-level decays at the level of a few degrees are difficult to appreciate. In view of these deficiencies of the UT plots with respect to $$|V_{cb}|$$ | V cb | and $$\gamma $$ γ and the central role these two CKM parameters will play in this decade, the recently proposed plots of $$|V_{cb}|$$ | V cb | versus $$\gamma $$ γ extracted from various processes appear to be superior to the UT plots in the flavour phenomenology of the 2020s. We illustrate this idea with $$\Delta F=2$$ Δ F = 2 observables $$\Delta M_s$$ Δ M s , $$\Delta M_d$$ Δ M d , $$\varepsilon _K$$ ε K and with rare decays $$B_s\rightarrow \mu ^+\mu ^-$$ B s → μ + μ - , $$B_d\rightarrow \mu ^+\mu ^-$$ B d → μ + μ - , $$K^+\rightarrow \pi ^+\nu \bar{\nu }$$ K + → π + ν ν ¯ and $$K_L\rightarrow \pi ^0\nu \bar{\nu }$$ K L → π 0 ν ν ¯ . In particular the power of $$\varepsilon _K$$ ε K , $$\mathcal {B}(K^+\rightarrow \pi ^+\nu \bar{\nu })$$ B ( K + → π + ν ν ¯ ) and $$\mathcal {B}(K_L\rightarrow \pi ^0\nu \bar{\nu })$$ B ( K L → π 0 ν ν ¯ ) in the determination of $$|V_{cb}|$$ | V cb | , due to their strong dependence on $$|V_{cb}|$$ | V cb | , is transparently exhibited in this manner. Combined with future reduced errors on $$\gamma $$ γ and $$|V_{cb}|$$ | V cb | from tree-level decays such plots can better exhibit possible inconsistencies between various determinations of these two parameters, caused by new physics, than it is possible with the UT plots. This can already be illustrated on the example of the recently found $$2.7\sigma $$ 2.7 σ anomaly in $$B_s\rightarrow \mu ^+\mu ^-$$ B s → μ + μ - .

show abstract

The Exclusive Vision of Rare $K$ and $B$ Decays and of the Quark Mixing in the Standard Model

Cited by 8 publications

References 37 publications

On the Superiority of the $|V_{cb}|-γ$ Plots over the Unitarity Triangle Plots in the 2020s

On the Superiority of the $|V_{cb}|-γ$ Plots over the Unitarity Triangle Plots in the 2020s

Chiral perturbation theory: reflections on effective theories of the standard model

On the superiority of the $$|V_{cb}|-\gamma $$ plots over the unitarity triangle plots in the 2020s

Contact Info

Product

Resources

About