Three - Loop Polarization Function and O ( α 2 s ) Corrections to the Production of Heavy Quarks †
نویسندگان
چکیده
The three-loop vacuum polarization function Π(q 2) induced by a massive quark is calculated. A comprehensive description of the method is presented. From the imaginary part the O(α 2 s) result for the production of heavy quarks R(s) = σ(e + e − → hadrons)/σ(e + e − → µ + µ −) can be extracted. Explicit formulae separated into the different colour factors are given.
منابع مشابه
Analytic Calculation of Two Loop Corrections to Heavy Quark Pair Production Vertices Induced by Light Quarks
Non-singlet O(α2 s ) corrections from light quarks are calculated analytically for the massive quark-antiquark pair production rates through the vector, axial-vector, scalar and pseudoscalar currents for all energies above the threshold. The results are presented in terms of the moments of the absorptive part of the vacuum polarization function of the light quarks, which allows for an immediate...
متن کاملHeavy - quark vacuum polarization : first two moments of the O ( α 3 s n 2 f ) contribution
The vacuum polarization due to a virtual heavy quark pair and specifically the coefficients of its Taylor expansion in the external momentum are closely related to moments of the cross section for quarkantiquark pair production in electron-positron annihilation. Relating measurement and theoretically calculated Taylor coefficients, an accurate value for charmand bottom-quark mass can be derived...
متن کاملLeading log radiative corrections to deep inelastic production of heavy quarks
O(α) QED radiative corrections to neutral current deep inelastic production of heavy quarks are calculated in the leading log approximation and compared with the corresponding corrections assuming a massless charm parton. Besides the inclusive case, corrections to the semi-inclusive dσ/dxdydz and the effect of z-cuts are studied. In the latter case, the massless corrections differ from the corr...
متن کاملar X iv : h ep - p h / 06 01 20 7 v 1 2 5 Ja n 20 06 Heavy - Quark Form Factors and Threshold Cross Section at O ( α 2 S )
During the last year, analytic expressions for the two-loop QCD corrections to the form factors for the vector, axial-vector, scalar and pseudo-scalar vertices involving a pair of heavy quarks, QQ̄, were calculated. The results are valid for arbitrary momentum transfer and mass of the heavy quarks. These form factors have a number of applications, including anomalous couplings, the e+e− → QQ̄ cro...
متن کاملCorrections of Order O ( G F α s m 2 t ) to the Higgs Decay Rate Γ ( H →
QCD corrections to the electroweak one-loop result for the partial width Γ(H → b ¯ b) are studied. For the decay channel into bottom quarks the rate is affected by a virtual top quark through electroweak interactions. The calculation of QCD corrections to this quantity is performed for an intermediate range Higgs mass in the heavy top mass limit. The leading correction of order O(G F α s m 2 t)...
متن کامل