V_cb
E815591
V_cb is the CKM matrix element that quantifies the strength of quark flavor-changing transitions between charm and bottom quarks in the Standard Model of particle physics.
All labels observed (1)
| Label | Occurrences |
|---|---|
| V_cb canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T9689293 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: V_cb Context triple: [Cabibbo–Kobayashi–Maskawa matrix, hasElement, V_cb]
-
A.
VCCB
VCCB is the ICAO airport code for Batticaloa Airport in Sri Lanka.
-
B.
VCK
VCK is a Tamil Nadu–based political party in India known for its advocacy of Dalit rights and social justice.
-
C.
.vc
.vc is the country code top-level domain (ccTLD) assigned to Saint Vincent and the Grenadines, often also used creatively for various commercial and personal websites.
-
D.
VCCR
VCCR is an international treaty that defines the framework for consular relations between independent states, including the rights and protections of consular officials and their nationals abroad.
-
E.
VVCI
VVCI is the ICAO airport code for Cat Bi International Airport in Hai Phong, Vietnam.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: V_cb Target entity description: V_cb is the CKM matrix element that quantifies the strength of quark flavor-changing transitions between charm and bottom quarks in the Standard Model of particle physics.
-
A.
VCCB
VCCB is the ICAO airport code for Batticaloa Airport in Sri Lanka.
-
B.
VCK
VCK is a Tamil Nadu–based political party in India known for its advocacy of Dalit rights and social justice.
-
C.
.vc
.vc is the country code top-level domain (ccTLD) assigned to Saint Vincent and the Grenadines, often also used creatively for various commercial and personal websites.
-
D.
VCCR
VCCR is an international treaty that defines the framework for consular relations between independent states, including the rights and protections of consular officials and their nationals abroad.
-
E.
VVCI
VVCI is the ICAO airport code for Cat Bi International Airport in Hai Phong, Vietnam.
- F. None of above. chosen
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
CKM matrix element
ⓘ
complex number ⓘ |
| affects |
predictions for B meson lifetimes and branching ratios
ⓘ
rates of rare B decays via normalization of b → c transitions ⓘ |
| appearsIn |
W boson couplings to quarks
ⓘ
charged-current weak interactions ⓘ |
| approximatelyEquals | A λ² in Wolfenstein parametrization ⓘ |
| constrainedBy | unitarity of the CKM matrix ⓘ |
| constrains | models of new physics affecting b → c transitions ⓘ |
| contributesTo | determination of CKM unitarity triangle ⓘ |
| dependsOn | hadronic form factors ⓘ |
| describes | quark flavor-changing transitions between charm and bottom quarks ⓘ |
| dimension | dimensionless ⓘ |
| expressedIn |
Wolfenstein parametrization of the CKM matrix
ⓘ
linked to:
Cabibbo–Kobayashi–Maskawa matrix
|
| governs |
b → c transitions
ⓘ
b̄ → c̄ transitions ⓘ |
| hasApproximateMagnitude |
0.04
ⓘ
|V_cb| ≈ 4 × 10⁻² ⓘ |
| hasPhaseConvention | can be chosen approximately real in standard CKM phase convention ⓘ |
| hasRole | input parameter in precision flavor physics ⓘ |
| hasUncertaintySource |
experimental systematics
ⓘ
theoretical form-factor calculations ⓘ |
| hierarchyProperty |
|V_cb| ≪ |V_cs| and |V_cb| ≪ |V_tb|
ⓘ
|V_cb| ≫ |V_ub| ⓘ |
| isSubjectOf |
heavy quark effective theory analyses
ⓘ
inclusive–exclusive determination tension studies ⓘ lattice QCD calculations ⓘ |
| matrixPosition | row corresponding to charm quark, column corresponding to bottom quark ⓘ |
| measuredIn |
exclusive B → D ℓ ν decays
ⓘ
exclusive B → D* ℓ ν decays ⓘ inclusive b → c ℓ ν decays ⓘ semileptonic B meson decays ⓘ |
| namedAfter |
Cabibbo
ⓘ
Kobayashi ⓘ Maskawa ⓘ |
| parameterOf | weak interaction Lagrangian ⓘ |
| partOf |
Cabibbo–Kobayashi–Maskawa matrix
ⓘ
Standard Model of particle physics ⓘ
linked to:
Standard Model
|
| relatedTo |
V_ub via CKM hierarchy
ⓘ
Wolfenstein parameter A ⓘ
linked to:
Wolfenstein parameterization
|
| relatesQuarkFlavor |
bottom quark
ⓘ
charm quark ⓘ |
| symbolFor | CKM element between second and third quark generations ⓘ |
| usedIn |
global CKM fits
ⓘ
normalization of b → c semileptonic spectra ⓘ tests of CKM unitarity in the second and third columns ⓘ |
| usedToDetermine | strength of b → c weak transitions ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: V_cb Description of subject: V_cb is the CKM matrix element that quantifies the strength of quark flavor-changing transitions between charm and bottom quarks in the Standard Model of particle physics.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.