nLab
V_cb puzzle

Contents

Context

Fields and quanta

field (physics)

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

hadron (bound states of the above quarks)

solitons

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 cbpuzzleV_{cb}-puzzle (see GJS 19 for the status as of May 2019) is an observation about the 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)

Created on May 21, 2019 at 04:03:53. See the history of this page for a list of all contributions to it.