The bottom-quark mass from non-relativistic sum rules at NNNLO

Beneke, Μ.; Maier, A. A.; Piclum, Jan; Rauh, Thomas

doi:10.1016/j.nuclphysb.2014.12.001

Cited by 73 publications

(92 citation statements)

References 76 publications

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“…Taking into account only the uncertainty from scale variation the uncertainty of the peak position amounts to ±60 MeV at N 3 LO with a factor two improvement relative to NNLO. The improvement is even larger for the peak height, which is relevant to the top quark width and Yukawa coupling determination as discussed above and in [39]. Note that these conclusions refer to the top quark PS mass (and not the pole mass), and correspondingly to the MS mass, which can be related to the PS mass with an accuracy of about 20 MeV [41].…”

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confidence: 71%

Next-to-Next-to-Next-to-Leading Order QCD Prediction for the Top AntitopS-Wave Pair Production Cross Section Near Threshold ine+e−Annihilation

et al. 2015

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We present the third-order QCD prediction for the production of top-anti-top quark pairs in electronpositron collisions close to the threshold in the dominant S-wave state. We observe a significant reduction of the theoretical uncertainty and discuss the sensitivity to the top quark mass and width.PACS numbers: 14.65. Ha, 12.38.Bx, 13.66.Bc Among the main motivations for building a future highenergy electron-positron collider in steps of increasing center-of-mass energy are precise measurements at √ s ≈ 345 GeV close to the production threshold of top antitop quark pairs. The peculiar behaviour of the cross section allows for the precise determination of a number of Standard Model parameters, most prominently the top quark mass. To date the most precise measurement of m t = 173.34±0.27(stat)±0.71(syst) GeV comes from the hadron colliders Fermilab Tevatron and CERN LHC [1] and is based on the reconstruction of the top and antitop quarks through their decay products. This approach and the value quoted above are plagued by unknown relations of the extracted mass value m t to top quark masses in the pole or MS renormalization scheme, which may well exceed 1 GeV. At hadron colliders there are also methods to determine directly a well-defined top quark mass, such as the extraction of m t from top quark cross section measurements. However, the final precision is of the order of a few GeV and thus significantly worse. At an electron-positron collider, on the other hand, scans of the top anti-top pair production threshold can lead to very precise measurements of well-defined mass values with a statistical accuracy of only 20-30 MeV [2,3]. Besides the top quark mass also its decay width and the strong coupling constant can be extracted with an accuracy of 21 MeV [3] and 0.0009 [2], respectively. A recent study has shown that for a Higgs boson with a mass of about 125 GeV the top quark Yukawa coupling can be obtained with a statistical uncertainty of only 4.2% [3]. These numbers pose several challenges to theory.A crucial input to reach the aimed precision is a precise calculation of the top anti-top pair production cross section in the threshold region. While the fundamental theory of quantum chromodyanmics (QCD) is wellestablished, performing calculations of quantum corrections to the very high accuracies demanded here is very difficult indeed. The problem is further complicated by the fact that in the threshold region the colour Coulomb potential ∝ α s /r, where α s denotes the strong coupling, can no longer be treated as a perturbation even though α s ≪ 1. Standard perturbation theory in α s breaks down and resummation is required.The relevant techniques have been developed in the 1990s in the framework of effective field theory (EFT), which accounts for the different dynamical scales in the problem. For a heavy quark anti-quark system at threshold there are three relevant scales, the hard scale m, the potential and soft scale mv, and the ultrasoft scale mv 2 , where m denotes the mass of the quark and v its velocit...

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confidence: 71%

Next-to-Next-to-Next-to-Leading Order QCD Prediction for the Top AntitopS-Wave Pair Production Cross Section Near Threshold ine+e−Annihilation

et al. 2015

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“…In contrast, the factorization scale entering the LCSR for the hadronic photon corrections will be taken as µ ∈ −0.033 GeV [44] in the MS scheme from non-relativistic sum rules. Finally, we turn to determine the Borel mass M 2 and the threshold parameter s 0 in the LCSR for the hadronic photon contributions.…”

Section: Jhep05(2018)184mentioning

confidence: 99%

Subleading-power corrections to the radiative leptonic B → γℓν decay in QCD

Wang

Shen

2018

J. High Energ. Phys.

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Applying the method of light-cone sum rules with photon distribution amplitudes, we compute the subleading-power correction to the radiative leptonic B → γ ν decay from the twist-two hadronic photon contribution at next-to-leading order in QCD; and further evaluate the higher-twist "resolved photon" corrections at leading order in α s , up to twist-four accuracy. QCD factorization for the vacuum-to-photon correlation function with an interpolating current for the B-meson is established explicitly at leading power in Λ/m b employing the evanescent operator approach. Resummation of the parametrically large logarithms of m 2 b /Λ 2 entering the hard function of the leading-twist factorization formula is achieved by solving the QCD evolution equation for the light-ray tensor operator at two loops. The leading-twist hadronic photon effect turns out to preserve the symmetry relation between the two B → γ form factors due to the helicity conservation, however, the higher-twist hadronic photon corrections can yield symmetry-breaking effect already at tree level in QCD. Using the conformal expansion of photon distribution amplitudes with the non-perturbative parameters estimated from QCD sum rules, the twist-two hadronic photon contribution can give rise to approximately 30% correction to the leading-power "direct photon" effect computed from the perturbative QCD factorization approach. In contrast, the subleading-power corrections from the higher-twist two-particle and three-particle photon distribution amplitudes are estimated to be of O(3 ∼ 5%) with the light-cone sum rule approach. We further predict the partial branching fractions of B → γ ν with a photonenergy cut E γ ≥ E cut , which are of interest for determining the inverse moment of the leading-twist B-meson distribution amplitude thanks to the forthcoming high-luminosity Belle II experiment at KEK.

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“…Likewise, we will adopt the intervals for the D-meson decay constant in QCD from lattice simulations f D = (209.2 ± 3.3) MeV [58] with N f = 2 + 1. In addition, we will employ the MS bottom quark mass m b (m b ) = (4.193 +0.022 −0.035 ) GeV [59] from non-relativistic sum rules and the MS charm quark mass m c (m c ) = (1.288 ± 0.020) GeV [60] from relativistic sum rules, employing the quark vector correlation function computed at O(α 3 s ). Following [15,41], the hard scales µ h1 and µ h2 are taken to be equal and will be varied in the interval [m b /2 , 2 m b ] around the default value m b , and the factorization scale is chosen as 1.0 GeV ≤ µ ≤ 2.0 GeV with the default value µ = 1.5 GeV.…”

Section: Jhep06(2017)062mentioning

confidence: 99%

Perturbative corrections to B → D form factors in QCD

Wang

Wei

Shen

et al. 2017

J. High Energ. Phys.

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We compute perturbative QCD corrections to B → D form factors at leading power in Λ/m b , at large hadronic recoil, from the light-cone sum rules (LCSR) with Bmeson distribution amplitudes in HQET. QCD factorization for the vacuum-to-B-meson correlation function with an interpolating current for the D-meson is demonstrated explicitly at one loop with the power counting scheme m c ∼ O √ Λ m b . The jet functions encoding information of the hard-collinear dynamics in the above-mentioned correlation function are complicated by the appearance of an additional hard-collinear scale m c , compared to the counterparts entering the factorization formula of the vacuum-to-B-meson correction function for the construction of B → π from factors. Inspecting the next-toleading-logarithmic sum rules for the form factors of B → D ν indicates that perturbative corrections to the hard-collinear functions are more profound than that for the hard functions, with the default theory inputs, in the physical kinematic region. We further compute the subleading power correction induced by the three-particle quark-gluon distribution amplitudes of the B-meson at tree level employing the background gluon field approach. The LCSR predictions for the semileptonic B → D ν form factors are then extrapolated to the entire kinematic region with the z-series parametrization. Phenomenological implications of our determinations for the form factors f +,0 BD (q 2 ) are explored by investigating the (differential) branching fractions and the R(D) ratio of B → D ν and by determining the CKM matrix element |V cb | from the total decay rate of B → Dµν µ .

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The bottom-quark mass from non-relativistic sum rules at NNNLO

Cited by 73 publications

References 76 publications

Next-to-Next-to-Next-to-Leading Order QCD Prediction for the Top AntitopS-Wave Pair Production Cross Section Near Threshold ine+e−Annihilation

Next-to-Next-to-Next-to-Leading Order QCD Prediction for the Top AntitopS-Wave Pair Production Cross Section Near Threshold ine+e−Annihilation

Subleading-power corrections to the radiative leptonic B → γℓν decay in QCD

Perturbative corrections to B → D form factors in QCD

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