Tobias Huber
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Research Interests
Tobias Huber has a total of 804 co-authors. Here are the top co-authors by number of shared publications:
- Farvah Mahmoudi
Institut de Physique des 2 Infinis de Lyon, UMR 5822
30 shared publications - Siavash Neshatpour
School of Particles and Accelerators Institute for Research in Fundamental Sciences (IPM) P.O. Box 19395 -5531 Tehran Iran
13 shared publications - Diego Martinez Santos
Universidade da Coruña
7 shared publications - Gang Yang
Chinese Academy of Sciences
7 shared publications - Enrico Lunghi
Indiana University
6 shared publications - Jack Jenkins
Universität Siegen
6 shared publications
Latest Publications
- Open Access
- 10 June 2026
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2026 (6) , 120
Nonlocal form factor of chromomagnetic penguin in B → Kℓ+ℓ− from QCD light-cone sum rules
A bstract: The branching fraction of the B → Kℓ + ℓ − decay has been measured recently by the LHC experiments, showing a deviation from theory predictions based on the Standard Model (SM). A major challenge in achieving a complete SM prediction and interpreting this discrepancy lies in the treatment of nonlocal hadronic effects. In B → Kℓ + ℓ − , these effects are cast in a single nonlocal form factor, a function of squared momentum transfer q 2 to the lepton pair. One of the previously used methods provides this form factor in the region of spacelike momentum transfer, q 2 < 0, matching the result to the hadronic dispersion relation, which is then continued to the physical region. The calculation done so far was a combination of QCD factorisation for hard-gluon contributions with light-cone sum rules (LCSRs) for soft-gluon ones. In this work, we calculate for the first time the complete nonlocal form factor at q 2 < 0 for one of the effective operators, the chromomagnetic operator O 8 g , applying the method of LCSRs with B -meson distribution amplitudes. We compute, both analytically and numerically, the operator-product expansion (OPE) diagrams with hard-gluon exchanges, analyse their structure and hierarchy, and obtain their spectral density entering the LCSR together with soft-gluon contributions. This study paves the way for our next task, a complete calculation of nonlocal B → Kℓ + ℓ − form factor at spacelike q 2 , including the dominant contributions of current-current operators, known as charm-loops.
- 10 June 2026
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2026 (6) , 120
Open AccessNonlocal form factor of chromomagnetic penguin in B → Kℓ+ℓ− from QCD light-cone sum rules
A bstract: The branching fraction of the B → Kℓ + ℓ − decay has been measured recently by the LHC experiments, showing a deviation from theory predictions based on the Standard Model (SM). A major challenge in achieving a complete SM prediction and interpreting this discrepancy lies in the treatment of nonlocal hadronic effects. In B → Kℓ + ℓ − , these effects are cast in a single nonlocal form factor, a function of squared momentum transfer q 2 to the lepton pair. One of the previously used methods provides this form factor in the region of spacelike momentum transfer, q 2 < 0, matching the result to the hadronic dispersion relation, which is then continued to the physical region. The calculation done so far was a combination of QCD factorisation for hard-gluon contributions with light-cone sum rules (LCSRs) for soft-gluon ones. In this work, we calculate for the first time the complete nonlocal form factor at q 2 < 0 for one of the effective operators, the chromomagnetic operator O 8 g , applying the method of LCSRs with B -meson distribution amplitudes. We compute, both analytically and numerically, the operator-product expansion (OPE) diagrams with hard-gluon exchanges, analyse their structure and hierarchy, and obtain their spectral density entering the LCSR together with soft-gluon contributions. This study paves the way for our next task, a complete calculation of nonlocal B → Kℓ + ℓ − form factor at spacelike q 2 , including the dominant contributions of current-current operators, known as charm-loops.
- Open Access
- 30 January 2026
- Published by Sissa Medialab Srl
NLO analysis of the subleading-power $Q_1-Q_{7\gamma}$ interference in $\bar{B}\to X_s\gamma$ at large photon energiesWe report on progress towards including next-to-leading order (NLO) radiative corrections to the subleading-power factorization formula for the 𝑄 𝑞 1-𝑄 7𝛾 interference contribution in B → 𝑋 𝑠 𝛾 at large photon energies, 𝑚 𝑏-2𝐸 𝛾 = O (Λ QCD). The novel ingredients for a NLO analysis are the one-loop anomalous dimension of the subleading shape function 𝑔 17 (𝜔, 𝜔 1 ; 𝜇), which was recently computed by us, and the two-loop corrections to the jet function with an internal charm loop. Here we summarize the renormalization of 𝑔 17 (𝜔, 𝜔 1 ; 𝜇), and further discuss that our insights allow for a simplified renormalization of a specific generalization of a three-particle 𝐵meson light-cone distribution amplitude, but with non-aligned light-like separations of the fields.
- 30 January 2026
- Published by Sissa Medialab Srl
Open AccessNLO analysis of the subleading-power $Q_1-Q_{7\gamma}$ interference in $\bar{B}\to X_s\gamma$ at large photon energiesWe report on progress towards including next-to-leading order (NLO) radiative corrections to the subleading-power factorization formula for the 𝑄 𝑞 1-𝑄 7𝛾 interference contribution in B → 𝑋 𝑠 𝛾 at large photon energies, 𝑚 𝑏-2𝐸 𝛾 = O (Λ QCD). The novel ingredients for a NLO analysis are the one-loop anomalous dimension of the subleading shape function 𝑔 17 (𝜔, 𝜔 1 ; 𝜇), which was recently computed by us, and the two-loop corrections to the jet function with an internal charm loop. Here we summarize the renormalization of 𝑔 17 (𝜔, 𝜔 1 ; 𝜇), and further discuss that our insights allow for a simplified renormalization of a specific generalization of a three-particle 𝐵meson light-cone distribution amplitude, but with non-aligned light-like separations of the fields.
- Open Access
- 21 January 2026
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2026 (1) , 142
Multi-parton contributions to $\overline{B}\to {X }_{s}\gamma $ at NLOA bstract: Many contributions to the decay rate of the inclusive radiative $$\overline{B}\to {X }_{s}\gamma $$ transition have been calculated to NNLO in QCD during the past decades. However, there are still a few unknown contributions from multi-parton final states which are formally NLO. In the present work, we compute those four-body $$b\to sq\overline{q }\gamma $$ contributions at NLO in QCD which need to be supplemented by the five-body $$b\to sq\overline{q }g\gamma $$ bremsstrahlung. This calculation formally completes the purely perturbative contributions to $$\overline{B}\to {X }_{s}\gamma $$ at NLO. Our results are obtained by applying modern techniques of integral reduction and evaluation of master integrals. In particular, the analytic integration over the four and five-particle phase space in the presence of a cut on the photon energy turns out to be technically involved. We give our results completely analytically in terms of multiple polylogarithms, including the dependence on the collinear logarithms which arise from the mass-regularisation of collinear divergences. The numerical impact of multi-parton corrections on the $$\overline{B}\to {X }_{s}\gamma $$ decay rate turns out to be small, owing to a partial cancellation between LO and NLO contributions.- 21 January 2026
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2026 (1) , 142
Open AccessMulti-parton contributions to $\overline{B}\to {X }_{s}\gamma $ at NLOA bstract: Many contributions to the decay rate of the inclusive radiative $$\overline{B}\to {X }_{s}\gamma $$ transition have been calculated to NNLO in QCD during the past decades. However, there are still a few unknown contributions from multi-parton final states which are formally NLO. In the present work, we compute those four-body $$b\to sq\overline{q }\gamma $$ contributions at NLO in QCD which need to be supplemented by the five-body $$b\to sq\overline{q }g\gamma $$ bremsstrahlung. This calculation formally completes the purely perturbative contributions to $$\overline{B}\to {X }_{s}\gamma $$ at NLO. Our results are obtained by applying modern techniques of integral reduction and evaluation of master integrals. In particular, the analytic integration over the four and five-particle phase space in the presence of a cut on the photon energy turns out to be technically involved. We give our results completely analytically in terms of multiple polylogarithms, including the dependence on the collinear logarithms which arise from the mass-regularisation of collinear divergences. The numerical impact of multi-parton corrections on the $$\overline{B}\to {X }_{s}\gamma $$ decay rate turns out to be small, owing to a partial cancellation between LO and NLO contributions. - Open AccessNLO analysis of the subleading-power $Q_1-Q_{7γ}$ interference in $\bar{B}\to X_sγ$ at large photon energiesWe report on progress towards including next-to-leading order (NLO) radiative corrections to the subleading-power factorization formula for the $Q_1^{q}-Q_{7γ}$ interference contribution in $\bar{B}\to X_sγ$ at large photon energies, $m_b - 2E_γ= \mathcal{O}(Λ_{\rm QCD})$. The novel ingredients for a NLO analysis are the one-loop anomalous dimension of the subleading shape function $g_{17}(ω,ω_1;μ)$, which was recently computed by us, and the two-loop corrections to the jet function with an internal charm loop. Here we summarize the renormalization of $g_{17}(ω,ω_1;μ)$, and further discuss that our insights allow for a simplified renormalization of a specific generalization of a three-particle $B$-meson light-cone distribution amplitude, but with non-aligned light-like separations of the fields.Open AccessNLO analysis of the subleading-power $Q_1-Q_{7γ}$ interference in $\bar{B}\to X_sγ$ at large photon energiesWe report on progress towards including next-to-leading order (NLO) radiative corrections to the subleading-power factorization formula for the $Q_1^{q}-Q_{7γ}$ interference contribution in $\bar{B}\to X_sγ$ at large photon energies, $m_b - 2E_γ= \mathcal{O}(Λ_{\rm QCD})$. The novel ingredients for a NLO analysis are the one-loop anomalous dimension of the subleading shape function $g_{17}(ω,ω_1;μ)$, which was recently computed by us, and the two-loop corrections to the jet function with an internal charm loop. Here we summarize the renormalization of $g_{17}(ω,ω_1;μ)$, and further discuss that our insights allow for a simplified renormalization of a specific generalization of a three-particle $B$-meson light-cone distribution amplitude, but with non-aligned light-like separations of the fields.
- Open Access
- 23 May 2025
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2025 (5) , 1-36
Renormalisation group evolution effects on global SMEFT analyses
Global analyses in the Standard Model Effective Field Theory (SMEFT) framework serve as a tool to probe potential directions of new physics. To break degeneracies between the Wilson coefficients of the SMEFT, it is essential to combine observables from various experiments. Since different observables entering global fits may be measured at different energy scales, it becomes increasingly important to account for this fact through the renormalisation group evolution (RGE) of the Wilson coefficients. In this work, we investigate the effects of the RGE on a global SMEFT fit under the assumption of a U(3)5 symmetry within the minimal flavour violation framework. We comment on the role of next-to-leading order SMEFT predictions for breaking potential degeneracies between Wilson coefficients arising as a result of RGE effects.
- 23 May 2025
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2025 (5) , 1-36
Open AccessRenormalisation group evolution effects on global SMEFT analyses
Global analyses in the Standard Model Effective Field Theory (SMEFT) framework serve as a tool to probe potential directions of new physics. To break degeneracies between the Wilson coefficients of the SMEFT, it is essential to combine observables from various experiments. Since different observables entering global fits may be measured at different energy scales, it becomes increasingly important to account for this fact through the renormalisation group evolution (RGE) of the Wilson coefficients. In this work, we investigate the effects of the RGE on a global SMEFT fit under the assumption of a U(3)5 symmetry within the minimal flavour violation framework. We comment on the role of next-to-leading order SMEFT predictions for breaking potential degeneracies between Wilson coefficients arising as a result of RGE effects.
- Open Access
- 13 May 2025
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2025 (5) , 1-2
Erratum to: Inclusive $ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $ at the LHC: theory predictions and new-physics reachA correction to this paper has been published: https://doi.org/10.1007/JHEP11(2024)130
- 13 May 2025
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2025 (5) , 1-2
Open AccessErratum to: Inclusive $ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $ at the LHC: theory predictions and new-physics reachA correction to this paper has been published: https://doi.org/10.1007/JHEP11(2024)130
- Open Access
- 9 April 2025
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2025 (4) , 1-37
Renormalisation group evolution of the shape function g17 in $ \overline{B}\to {X}_s\gamma $ and $ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $ at subleading powerWe derive and solve the renormalisation-group (RG) equation of the shape function g 17(ω, ω 1; μ), which appears at subleading power in the factorisation of the inclusive decays $$ \overline{B}\to {X}_s\gamma $$ and $$ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $$ . Our results provide the first ingredient for a next-to-leading order analysis of the respective resolved-photon $$ {Q}_1^c-{Q}_{7\gamma } $$ interference contribution, whose current uncertainties are among the largest ones in both inclusive penguin modes. As a by-product of our study, we find that the analytic properties of the soft anomalous dimension as well as the jet functions in a factorisation theorem allow for a simplified renormalisation of operators in Heavy-Quark Effective Theory that are composed of fields smeared along distinct light-cone directions. Their hadronic matrix elements become relevant in various inclusive and exclusive B-decays beyond leading power in the heavy-quark and large-energy expansion. Using these insights, we derive and solve a simpler “reduced” RG equation of an amplitude-level soft function that describes the long-distance QCD dynamics for penguin contributions to exclusive $$ {\overline{B}}_{d,s}\to \gamma \gamma $$ decays, and which has recently been discussed in the literature.- 9 April 2025
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2025 (4) , 1-37
Open AccessRenormalisation group evolution of the shape function g17 in $ \overline{B}\to {X}_s\gamma $ and $ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $ at subleading powerWe derive and solve the renormalisation-group (RG) equation of the shape function g 17(ω, ω 1; μ), which appears at subleading power in the factorisation of the inclusive decays $$ \overline{B}\to {X}_s\gamma $$ and $$ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $$ . Our results provide the first ingredient for a next-to-leading order analysis of the respective resolved-photon $$ {Q}_1^c-{Q}_{7\gamma } $$ interference contribution, whose current uncertainties are among the largest ones in both inclusive penguin modes. As a by-product of our study, we find that the analytic properties of the soft anomalous dimension as well as the jet functions in a factorisation theorem allow for a simplified renormalisation of operators in Heavy-Quark Effective Theory that are composed of fields smeared along distinct light-cone directions. Their hadronic matrix elements become relevant in various inclusive and exclusive B-decays beyond leading power in the heavy-quark and large-energy expansion. Using these insights, we derive and solve a simpler “reduced” RG equation of an amplitude-level soft function that describes the long-distance QCD dynamics for penguin contributions to exclusive $$ {\overline{B}}_{d,s}\to \gamma \gamma $$ decays, and which has recently been discussed in the literature. - Open Access
- 22 November 2024
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2024 (11) , 1-23
Inclusive $ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $ at the LHC: theory predictions and new-physics reachWe present theoretical predictions for observables in inclusive $$ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $$ suitable for measurements at hadron colliders through a sum-over-exclusive approach. At low q 2 we calculate the branching ratio and three angular observables. At high q 2 we provide the branching ratio and the ratio of the $$ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $$ rate with respect to the inclusive $$ \overline{B}\to {X}_u\ell \overline{\nu} $$ rate with the same phase-space cut. We compare our predictions to the B factory measurements and also to an extraction of the experimental rate through a sum-over-exclusive method using branching ratios of the exclusive $$ \overline{B}\to {K}^{\left(\ast \right)}{\mu}^{+}{\mu}^{-} $$ modes measured at LHCb. We find a consistent picture comparing Standard Model theory and experiment. As such, our analysis does not support a recent claim about a deficit in the inclusive branching ratio in the high-q 2 region. Finally, we present current model-independent bounds on new physics and emphasize the potential of complementary analyses of $$ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $$ at Belle II and the LHC.- 22 November 2024
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2024 (11) , 1-23
Open AccessInclusive $ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $ at the LHC: theory predictions and new-physics reachWe present theoretical predictions for observables in inclusive $$ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $$ suitable for measurements at hadron colliders through a sum-over-exclusive approach. At low q 2 we calculate the branching ratio and three angular observables. At high q 2 we provide the branching ratio and the ratio of the $$ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $$ rate with respect to the inclusive $$ \overline{B}\to {X}_u\ell \overline{\nu} $$ rate with the same phase-space cut. We compare our predictions to the B factory measurements and also to an extraction of the experimental rate through a sum-over-exclusive method using branching ratios of the exclusive $$ \overline{B}\to {K}^{\left(\ast \right)}{\mu}^{+}{\mu}^{-} $$ modes measured at LHCb. We find a consistent picture comparing Standard Model theory and experiment. As such, our analysis does not support a recent claim about a deficit in the inclusive branching ratio in the high-q 2 region. Finally, we present current model-independent bounds on new physics and emphasize the potential of complementary analyses of $$ \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} $$ at Belle II and the LHC. - Open Access
- 6 September 2024
- Published by American Physical Society (APS) in Physical Review D
- Vol. 110 (5) , 056011
Heavy-to-light form factors to three loops
We compute three-loop corrections of to form factors with one massive and one massless quark coupling to an external vector, axialvector, scalar, pseudoscalar, or tensor current. We obtain analytic results for the color-planar contributions, for the contributions of light-quark loops, and the contributions with two heavy-quark loops. For the computation of the remaining master integrals we use the “expand and match” approach which leads to semianalytic results for the form factors. We implement our results in a Mathematica and a fortran code which allows for fast and precise numerical evaluations in the physically relevant phase space. The form factors are used to compute the hard matching coefficients in Soft-Collinear Effective Theory for all currents. The tensor coefficients at lightlike momentum transfer are used to extract the hard function in to three loops.- 6 September 2024
- Published by American Physical Society (APS) in Physical Review D
- Vol. 110 (5) , 056011
Open AccessHeavy-to-light form factors to three loops
We compute three-loop corrections of to form factors with one massive and one massless quark coupling to an external vector, axialvector, scalar, pseudoscalar, or tensor current. We obtain analytic results for the color-planar contributions, for the contributions of light-quark loops, and the contributions with two heavy-quark loops. For the computation of the remaining master integrals we use the “expand and match” approach which leads to semianalytic results for the form factors. We implement our results in a Mathematica and a fortran code which allows for fast and precise numerical evaluations in the physically relevant phase space. The form factors are used to compute the hard matching coefficients in Soft-Collinear Effective Theory for all currents. The tensor coefficients at lightlike momentum transfer are used to extract the hard function in to three loops. - Open Access
- 8 May 2024
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2024 (5) , 1-42
A global analysis of the SMEFT under the minimal MFV assumption
We present comprehensive global fits of the SMEFT under the minimal minimal flavour violation (MFV) hypothesis, i.e. assuming that only the flavour-symmetric and CP-invariant operators are relevant at the high scale. The considered operator set is determined by this flavour assumption rather than the used datasets. We establish global limits on these Wilson coefficients using leading order and next-to-leading order SMEFT predictions for electroweak precision observables, Higgs, top, flavour and dijet data as well as measurements from parity violation experiments and lepton scattering. Our investigations reveal an intriguing crosstalk among different observables, underscoring the importance of combining diverse observables from various energy scales in global SMEFT analyses.
- 8 May 2024
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2024 (5) , 1-42
Open AccessA global analysis of the SMEFT under the minimal MFV assumption
We present comprehensive global fits of the SMEFT under the minimal minimal flavour violation (MFV) hypothesis, i.e. assuming that only the flavour-symmetric and CP-invariant operators are relevant at the high scale. The considered operator set is determined by this flavour assumption rather than the used datasets. We establish global limits on these Wilson coefficients using leading order and next-to-leading order SMEFT predictions for electroweak precision observables, Higgs, top, flavour and dijet data as well as measurements from parity violation experiments and lepton scattering. Our investigations reveal an intriguing crosstalk among different observables, underscoring the importance of combining diverse observables from various energy scales in global SMEFT analyses.