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V_cb puzzle

Contents

Context

Fields and quanta

fields and particles in particle physics

and in the standard model of particle physics:

force field gauge bosons

scalar bosons

matter field fermions (spinors, Dirac fields)

flavors of fundamental fermions in the
standard model of particle physics:
generation of fermions1st generation2nd generation3d generation
quarks (qq)
up-typeup quark (uu)charm quark (cc)top quark (tt)
down-typedown quark (dd)strange quark (ss)bottom quark (bb)
leptons
chargedelectronmuontauon
neutralelectron neutrinomuon neutrinotau neutrino
bound states:
mesonslight mesons:
pion (udu d)
ρ-meson (udu d)
ω-meson (udu d)
f1-meson
a1-meson
strange-mesons:
ϕ-meson (ss¯s \bar s),
kaon, K*-meson (usu s, dsd s)
eta-meson (uu+dd+ssu u + d d + s s)

charmed heavy mesons:
D-meson (uc u c, dcd c, scs c)
J/ψ-meson (cc¯c \bar c)
bottom heavy mesons:
B-meson (qbq b)
ϒ-meson (bb¯b \bar b)
baryonsnucleons:
proton (uud)(u u d)
neutron (udd)(u d d)

(also: antiparticles)

effective particles

hadrons (bound states of the above quarks)

solitons

in grand unified theory

minimally extended supersymmetric standard model

superpartners

bosinos:

sfermions:

dark matter candidates

Exotica

auxiliary fields

Physics

physics, mathematical physics, philosophy of physics

Surveys, textbooks and lecture notes


theory (physics), model (physics)

experiment, measurement, computable physics

Contents

Idea

In particle physics, what is called the V cbV_{cb}-puzzle (status updates in GJS 19, Ricciardi 21) is an observation about the semileptonic decay of B-mesons (by the Belle collaboration and other experiments) which implies a value of the element |V cb|\left\vert V_{c b}\right\vert in the CKM matrix that differs from the apparent prediction of the standard model of particle physics with a statistical significance of about 3σ3 \sigma. But the form factors involved in this prediction suffer from theoretical uncertainties of quark contributions, and further lattice QCD-computation is expected to be required to clarify the actual prediction of the standard model of particle physics (GJS 19, last sentence).

The V cbV_{c b}-puzzle is different from, but related to, the flavour anomalies (GJS 19 (6))

References

  • Paolo Gambino, Martin Jung, Stefan Schacht, The V cbV_{c b} puzzle: an update (arXiv:1905.08209)

  • Giulia Ricciardi, Semileptonic B decays and |V xb|\vert V_{x b}\vert update (arXiv:2103.06099)

With emphasis on lattice QCD-computations:

Last revised on April 1, 2021 at 00:33:28. See the history of this page for a list of all contributions to it.