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A. G. Grozin

Publications and source records attributed to A. G. Grozin.

At least 19 recordsLinked to original sources
arXiv2020

HQET vertex diagram: $\varepsilon$ expansion

Differential equations for the one-loop HQET vertex diagram with arbitrary self-energy insertions and arbitrary residual energies are reduced to the $\varepsilon$ form and used to obtain the $\varepsilon$ expansion in terms of Goncharov polylogarithms.

hep-ph↗
arXiv2018

Four-loop results for the cusp anomalous dimension

We review the current status of calculations of the HQET field anomalous dimension and the cusp anomalous dimension. In particular, we give the results at 4 loops for the quartic Casimir contribution, and for the full QED case, up to $φ^6$ in the small angle expansion. Furthermore, we discuss the leading terms in the anti-parallel lines limit at four loops.

hep-ph↗
arXiv2017

Heavy quark form factors in the large $β_0$ limit

Heavy quark form factors are calculated at $β_0 α_s \sim 1$ to all orders in $α_s$ at the first order in $1/β_0$. The $n_f^2 α_s^3$ terms in the recent results [arXiv:1611.07535] for the vector form factors are confirmed, and $n_f^{L-1} α_s^L$ terms for higher $L$ are predicted.

hep-ph↗
arXiv2011

HQET heavy-heavy vertex diagram with two velocities

The one-loop HQET heavy-heavy vertex diagram with arbitrary powers of all three denominators and arbitrary residual energies is investigated. Various particular cases in which the result becomes simpler are considered.

hep-ph↗
arXiv2010

Matching heavy-quark fields in QCD and HQET at three loops

The relation between the heavy-quark field in QCD and the corresponding field in HQET is derived up to three loops, and to all orders in the large-$β_0$ limit. The corresponding relation between the QED electron field and the Bloch--Nordsieck one is gauge invariant to all orders. We also prove that the $\bar{\text{MS}}$ anomalous dimension of the QED electron field depends on the gauge parameter only at one loop.

hep-ph↗
arXiv2010

Matching QCD and HQET heavy-light currents at three loops

We consider the currents formed by a heavy and a light quark within Quantum Chromodynamics and compute the matching to Heavy Quark Effective Theory to three-loop accuracy. As an application we obtain the third-order perturbative corrections to ratios of B-meson decay constants.

hep-ph↗
arXiv2009

Three-loop on-shell Feynman integrals with two masses

All three-loop on-shell QCD Feynman integrals with two masses can be reduced to 27 master integrals. Here we calculate these master integrals, expanded in epsilon, both exactly in the mass ratio and as series in limiting cases.

hep-ph↗
arXiv2008

Higher radiative corrections in HQET

After a brief introduction to Heavy Quark Effective Theory, we discuss $α$ representation in HQET and methods of calculation of some kinds of HQET diagrams up to three loops.

hep-ph↗