43 research outputs found
The O(\alpha_s^3) Heavy Flavor Contributions to the Charged Current Structure Function xF_3(x,Q^2) at Large Momentum Transfer
We calculate the massive Wilson coefficients for the heavy flavor
contributions to the non-singlet charged current deep-inelastic scattering
structure function in the asymptotic
region to 3-loop order in Quantum Chromodynamics (QCD) at general
values of the Mellin variable and the momentum fraction . Besides the
heavy quark pair production also the single heavy flavor excitation contributes. Numerical results are presented for the charm quark
contributions and consequences on the Gross-Llewellyn Smith sum rule are
discussed.Comment: 30 pages, 6 figures. arXiv admin note: text overlap with
arXiv:1504.0821
3-Loop Heavy Flavor Corrections in Deep-Inelastic Scattering with Two Heavy Quark Lines
We consider gluonic contributions to the heavy flavor Wilson coefficients at
3-loop order in QCD with two heavy quark lines in the asymptotic region . Here we report on the complete result in the case of two equal
masses for the massive operator matrix element ,
which contributes to the corresponding heavy flavor transition matrix element
in the variable flavor number scheme. Nested finite binomial sums and iterated
integrals over square-root valued alphabets emerge in the result for this
quantity in and -space, respectively. We also present results for the
case of two unequal masses for the flavor non-singlet OMEs and on the scalar
integrals ic case of , which were calculated without a further
approximation. The graphs can be expressed by finite nested binomial sums over
generalized harmonic sums, the alphabet of which contains rational letters in
the ratio .Comment: 10 pages LATEX, 1 Figure, Proceedings of Loops and Legs in Quantum
Field Theory, Weimar April 201
3-loop Massive Contributions to the DIS Operator Matrix Element
Contributions to heavy flavour transition matrix elements in the variable
flavour number scheme are considered at 3-loop order. In particular a
calculation of the diagrams with two equal masses that contribute to the
massive operator matrix element is performed. In the Mellin
space result one finds finite nested binomial sums. In -space these sums
correspond to iterated integrals over an alphabet containing also square-root
valued letters.Comment: 4 pages, Contribution to the Proceedings of QCD '14, Montpellier,
July 201
Recent progress on the calculation of three-loop heavy flavor Wilson coefficients in deep-inelastic scattering
We report on our latest results in the calculation of the three-loop heavy
flavor contributions to the Wilson coefficients in deep-inelastic scattering in
the asymptotic region . We discuss the different methods used to
compute the required operator matrix elements and the corresponding Feynman
integrals. These methods very recently allowed us to obtain a series of new
operator matrix elements and Wilson coefficients like the flavor non-singlet
and pure singlet Wilson coefficients.Comment: 11 pages Latex, 2 Figures, Proc. of Loops and Legs in Quantum Field
Theory, April 2014, Weimar, German
The 3-Loop Non-Singlet Heavy Flavor Contributions and Anomalous Dimensions for the Structure Function and Transversity
We calculate the massive flavor non-singlet Wilson coefficient for the heavy
flavor contributions to the structure function in the asymptotic
region and the associated operator matrix element to 3-loop order in Quantum Chromodynamics at general values of the
Mellin variable . This matrix element is associated to the vector current
and axial vector current for the even and the odd moments , respectively. We
also calculate the corresponding operator matrix elements for transversity,
compute the contributions to the 3-loop anomalous dimensions to and
compare to results in the literature. The 3-loop matching of the flavor
non-singlet distribution in the variable flavor number scheme is derived. All
results can be expressed in terms of nested harmonic sums in space and
harmonic polylogarithms in -space. Numerical results are presented for the
non-singlet charm quark contribution to .Comment: 82 pages, 3 style files, 33 Figure
New Results on Massive 3-Loop Wilson Coefficients in Deep-Inelastic Scattering
We present recent results on newly calculated 2- and 3-loop contributions to
the heavy quark parts of the structure functions in deep-inelastic scattering
due to charm and bottom.Comment: Contribution to the Proc. of Loops and Legs 2016, PoS, in prin
3-loop heavy flavor Wilson coefficients in deep-inelastic scattering
We present our most recent results on the calculation of the heavy flavor
contributions to deep-inelastic scattering at 3-loop order in the large
limit, where the heavy flavor Wilson coefficients are known to factorize into
light flavor Wilson coefficients and massive operator matrix elements. We
describe the different techniques employed for the calculation and show the
results in the case of the heavy flavor non-singlet and pure singlet
contributions to the structure function .Comment: 4 pages Latex, 2 style files, 4 Figures, Contribution to the
Proceedings of QCD '14, Montpellier, Jult 201
3-Loop Corrections to the Heavy Flavor Wilson Coefficients in Deep-Inelastic Scattering
A survey is given on the status of 3-loop heavy flavor corrections to
deep-inelastic structure functions at large enough virtualities .Comment: 13 pages Latex, 8 Figures, Contribution to the Proceedings of EPS
2015 Wie
The O(\alpha_s^3 T_F^2) Contributions to the Gluonic Operator Matrix Element
The contributions to the transition matrix
element relevant for the variable flavor number scheme at 3--loop
order are calculated. The corresponding graphs contain two massive fermion
lines of equal mass leading to terms given by inverse binomially weighted sums
beyond the usual harmonic sums. In -space two root-valued letters contribute
in the iterated integrals in addition to those forming the harmonic
polylogarithms. We outline technical details needed in the calculation of
graphs of this type, which are as well of importance in the case of two
different internal massive lines.Comment: 39 papges LATEX, 8 Figure
Exact N3LO results for qq ′ → H + X
We compute the contribution to the total cross section for the inclusive production of a Standard Model Higgs boson induced by two quarks with different flavour in the initial state. Our calculation is exact in the Higgs boson mass and the partonic center-of-mass energy. We describe the reduction to master integrals, the construction of a canonical basis, and the solution of the corresponding differential equations. Our analytic result contains both Harmonic Polylogarithms and iterated integrals with additional letters in the alphabet. © 2015, The Author(s)