LHCb published a measurement of |Vub/Vcb|= from the
partial rate for Λb→pμν normalized to
Λb→Λcμν, [arXiv:1504.01568].
The published value, |Vub/Vcb|=0.083±0.004exp.±0.004th.
updated to the PDG2018 average for the Branching Fraction BF(Λc→p K π)=(6.28 ± 0.32)%,
is
|Vub/Vcb|=0.079±0.004exp.±0.004th.
LHCb published a measurement of Bs→K μν normalized to Bs→Ds μν decays. The measurement has been performed in two bins of q2. The resul, using recent Lattice calculation for q2 > 7 GeV2 is
|Vub/Vcb|=0.095±0.004exp.±0.007th.
The combination gives |Vub/Vcb|=0.0838±0.046tot
The average of the |Vcb| obtained from B→D l;ν, B→D*lν½ and Bs→ Ds(*)μμ,
is |Vcb|=38.90±0.53tot x 10-3.
The result of a combined fit using as input only the exclusive |Vub| and |Vcb| measurements, with the |Vub/Vcb| measurements from LHCb gives the following results
|Vub|=(3.51 ±0.12)x10-3
|Vcb|=(39.10 ±0.50)x10-3
the correlation is ρ=0.175, with a fit P(χ2)=8.9%. In this combination the uncertainties
are considered uncorrelated.
The result of the fit is shown here
.C,
.pdf,
.png.