The Status of ∣Vub∣

Gibbons, L.

doi:10.1063/1.1807315

Cited by 8 publications

(6 citation statements)

References 90 publications

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“…Due to the three indices the decompositions become rather lengthy, so we will not write them out explicitly. 4 Instead, we define the shape functions as in Eqs. (46) by projecting out the independent Lorentz structures, which is done in the appendix.…”

Section: Subleading Operatorsmentioning

confidence: 99%

“…Moment analyses of B → X c ℓν ℓ decay distributions have provided a precision measurement of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |V cb | at the two-percent level, along with an extraction of the b-quark and c-quark masses, and higher order hadronic parameters [1,2,3]. Similarly, the study of inclusive decays B → X u ℓν ℓ allows for an extraction of |V ub | with current errors of 10%-15% [4,5,6,7,8,9].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Full-phase-space twist expansion in semileptonic and radiativeB-meson decays

Tackmann

2005

Phys. Rev. D

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We study the Λ QCD /M B corrections from subleading shape functions in inclusive B-meson decays. We propose a natural and smooth interpolation from the endpoint region to the full phase space, and derive expressions for the triple differential decay rate in B → X u ℓν ℓ and the photon energy spectrum in B → X s γ. Our results are valid to order Λ QCD /M B for hadronic invariant masses of order Λ QCD M B and to order Λ 2 QCD /M 2 B for larger hadronic masses. They allow a systematic investigation of the transition between the separate regimes of the local and nonlocal expansions, and can be used to study decay distributions in any kinematic variables. We consider several examples of interest and point out that a combined measurement of hadronic energy and invariant mass provides an alternative to the extraction of |V ub | which is largely independent of shape-function effects and in principle allows a higher accuracy than the combined measurement of leptonic and hadronic invariant masses. We perform the expansion directly in QCD light-cone operators, and give a discussion of the general basis of light-cone operators. Reparametrization invariance under the change of the light-cone direction reduces the number of independent shape functions. We show that differing previous results for the lepton energy spectrum obtained from different choices of light-cone coordinates are in agreement.

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Section: Subleading Operatorsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Full-phase-space twist expansion in semileptonic and radiativeB-meson decays

Tackmann

2005

Phys. Rev. D

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“…In Schwarzschild-(A)dS spacetimes, however, the presence of Λ = 0 provides the missing ingredient. The basic idea of extended thermodynamic phase space, or "black hole chemistry", is to regard the cosmological constant of anti de Sitter (AdS) spacetime as a thermodynamic variable [7], analogous to pressure in the first law [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. The original motivations for so doing originate from a consideration of the Smarr relation [24], which is satisfied provided Λ is taken to be thermodynamic pressure [8,9].…”

Section: Introductionmentioning

confidence: 99%

Lower-dimensional black hole chemistry

2015

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The connection between black hole thermodynamics and chemistry is extended to the lowerdimensional regime by considering the rotating and charged BTZ metric in the (2 + 1)-D and a (1 + 1)-D limits of Einstein gravity. The Smarr relation is naturally upheld in both BTZ cases, where those with Q = 0 violate the Reverse Isoperimetric Inequality and are thus superentropic. The inequality can be maintained, however, with the addition of a new thermodynamic work term associated with the mass renormalization scale. The D → 0 limit of a generic D + 2-dimensional Einstein gravity theory is also considered to derive the Smarr and Komar relations, although the opposite sign definitions of the cosmological constant and thermodynamic pressure from the D > 2 cases must be adopted in order to satisfy the relation. The requirement of positive entropy implies an upper bound on the mass of a (1 + 1)-D black hole. Promoting an associated constant of integration to a thermodynamic variable allows one to define a "rotation" in one spatial dimension. Neither the D = 3 nor the D → 2 black holes exhibit any interesting phase behaviour.

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“…Analysis of moments of the inclusive decay spectra allow continuing refinements [37]. The improved understanding also aids the extraction of V ub , where the errors from exclusive and inclusive approaches are comparable (though the results are not in perfect agreement) at about 7% [36,38]. The inclusive analysis is dominated by new results from BABAR [39], Belle [40] and CLEO [41] in the B → πlν channel, complemented by improved lattice calculations [42].…”

Section: The Unitary Trianglementioning

confidence: 99%

Beauty 2006 – Conference Summary and Future Prospects

Gershon

2007

Nuclear Physics B - Proceedings Supplements

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The Status of ∣Vub∣

Cited by 8 publications

References 90 publications

Full-phase-space twist expansion in semileptonic and radiativeB-meson decays

Full-phase-space twist expansion in semileptonic and radiativeB-meson decays

Lower-dimensional black hole chemistry

Beauty 2006 – Conference Summary and Future Prospects

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