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Related papers: Singlet and non-singlet three-loop massive form fa…

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The non-diagonal correlators of vector and scalar currents are considered at three-loop order in QCD. The full mass dependence is computed in the case where one of the quarks is massless and the other one carries the mass $M$. As…

High Energy Physics - Phenomenology · Physics 2009-10-31 K. G. Chetyrkin , M. Steinhauser

Future high luminosity polarized deep--inelastic scattering experiments will improve both the knowledge of the spin sub--structure of the nucleons and contribute further to the precision determination of the strong coupling constant, as…

High Energy Physics - Phenomenology · Physics 2022-02-16 J. Blümlein , P. Marquard , C. Schneider , K. Schönwald

We extend a local subtraction framework to three-loop QCD corrections for the production of multiple electroweak bosons in quark-antiquark annihilation. We derive two-loop Ward identities that ensure the factorisation of most collinear…

High Energy Physics - Phenomenology · Physics 2025-11-11 Rayan Haindl

We perform a high-precision computation of the three-loop three-point form factor of the stress-tensor supermultiplet in ${\cal N}=4$ SYM. Both the leading-color and non-leading-color form factors are expanded in terms of simple integrals.…

High Energy Physics - Theory · Physics 2024-03-04 Xin Guan , Guanda Lin , Xiao Liu , Yan-Qing Ma , Gang Yang

We compute the matching coefficient between the quantum chromodynamics (QCD) and the non-relativistic QCD ( NRQCD) for the flavor-changing scalar current involving the heavy charm and bottom quark, up to the three-loop order within the…

High Energy Physics - Phenomenology · Physics 2023-05-03 Wei Tao , Ruilin Zhu , Zhen-Jun Xiao

We present preliminary results of a determination of the semileptonic form factor for the decay of pseudoscalar heavy-light mesons to pseudoscalar light-light mesons in full QCD. In this preliminary study we focus on the effects of…

High Energy Physics - Lattice · Physics 2008-11-26 C. Bernard , C. DeTar , Steven Gottlieb , E. Gregory , Urs Heller , C. McNeile , J. Osborn , R. Sugar , D. Toussaint

We compute three-loop vertex corrections to $b\to s\gamma$ induced by current-current operators. The results are presented as expansions in $m_c/m_b$ with numerical coefficients which allow to cover all relevant values for the heavy quark…

High Energy Physics - Phenomenology · Physics 2023-12-11 Matteo Fael , Fabian Lange , Kay Schoenwald , Matthias Steinhauser

In the framework of analytic approach to QCD the nonperturbative contributions in running coupling of strong interaction up to 4-loop order are obtained in an explicit form. For all $Q>\Lambda$ they are shown to be represented in the form…

High Energy Physics - Phenomenology · Physics 2009-11-07 Aleksey I. Alekseev

The three-loop form factors in massless QCD can be expressed as a linear combination of master integrals. Besides a number of master integrals which factorise into products of one-loop and two-loop integrals, one finds 16 genuine three-loop…

High Energy Physics - Phenomenology · Physics 2010-04-05 T. Gehrmann , G. Heinrich , T. Huber , C. Studerus

We compute the next-to-next-to-leading order (NNLO) contributions to the three splitting functions governing the evolution of unpolarized non-singlet combinations of quark densities in perturbative QCD. Our results agree with all partial…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Moch , J. A. M. Vermaseren , A. Vogt

We use the method of differential equations to analytically evaluate all planar three-loop Feynman integrals relevant for form factor calculations involving massive particles. Our results for ninety master integrals at general $q^2$ are…

High Energy Physics - Phenomenology · Physics 2017-02-01 Johannes M. Henn , Alexander V. Smirnov , Vladimir A. Smirnov

Light quark masses can be determined through lattice simulations in regularization invariant momentum-subtraction(RI/MOM) schemes. Subsequently, matching factors, computed in continuum perturbation theory, are used in order to convert these…

High Energy Physics - Phenomenology · Physics 2011-05-04 Leandro G. Almeida , Christian Sturm

Three-loop QCD corrections to the vector current correlator are considered. The large momentum procedure is applied in order to evaluate mass corrections up to order $(m^2/q^2)^6$. The inclusion of the first seven terms to the ratio…

High Energy Physics - Phenomenology · Physics 2009-10-30 K. G. Chetyrkin , R. Harlander , J. H. Kuehn , M. Steinhauser

We consider the Z Q Qbar vertex to second order in the QCD coupling for an on-shell massive quark-antiquark pair and for arbitrary momentum transfer of the Z boson. We present closed analytic expressions for the two parity-violating form…

High Energy Physics - Phenomenology · Physics 2010-04-05 W. Bernreuther , R. Bonciani , T. Gehrmann , R. Heinesch , T. Leineweber , P. Mastrolia , E. Remiddi

We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the structure function $F_2(x,Q^2)$ in the asymptotic region $Q^2 \gg m^2$ and the associated operator matrix element $A_{qq,Q}^{(3), \rm…

High Energy Physics - Phenomenology · Physics 2014-07-23 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. Hasselhuhn , A. von Manteuffel , M. Round , C. Schneider , F. Wißbrock

This paper provides details of the massless three-loop three-point integrals calculation at the symmetric point. Our work aimed to extend known two-loop results for such integrals to the three-loop level. Obtained results can find their…

High Energy Physics - Phenomenology · Physics 2021-06-17 Andrey Pikelner

In this letter we continue the calculation of master integrals for massless three-loop form factors by giving analytical results for those integrals which are relevant for the fermionic contributions proportional to N_F^2, N_F*N, and N_F/N.…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Heinrich , T. Huber , D. Maitre

Single-scale quantities, like the QCD anomalous dimensions and Wilson coefficients, obey difference equations. Therefore their analytic form can be determined from a finite number of moments. We demonstrate this in an explicit calculation…

High Energy Physics - Phenomenology · Physics 2014-11-18 J. Blümlein , M. Kauers , S. Klein , C. Schneider

The strange-quark vector current $\rho$-to-$\pi$ meson transition form factor is computed at one-loop order using strange meson intermediate states. A comparison is made with a $\phi$-meson dominance model estimate. We find that one-loop…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. L. Goity , M. J. Musolf

QCD sum rules for the determination of form factors of $\Lambda_b$ and $\Lambda_c$ semileptonic decays are investigated. With a form for the baryonic current appropriate for the limits of the heavy quark symmetries, the different tensor…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. S. Marques de Carvalho , F. S. Navarra , M. Nielsen , E. Ferreira , H. G. Dosch