8,891 research outputs found
QCD corrections to double J/\psi production in e+e- annihilation at \sqrt{s}=10.6 GeV
Next-to-Leading-Order(NLO) QCD corrections to double J/psi production in
e^+e^- annihilation at sqrt{s}=10.6 GeV are calculated. We find that they
greatly decrease the cross section, with a K factor (NLO/LO) ranging from -0.31
to 0.25 depending on the renormalization scale. Although the renormalization
scale dependence indicates a large uncertainty, when combined with the NLO QCD
corrections to J/psi + eta_c production, it can explain why the double J/psi$
production could not be found at B factories while the J/psi + eta_c production
could, despite the fact that cross section of the former is larger than that of
the latter at LO by a factor of 1.8.Comment: 4 pages, 4 figures, use revtex
QCD corrections to J/psi plus eta_c production in e+e- annihilation at sqrt{s}=10.6 GeV
Next-to-Leading-Order(NLO) QCD corrections to J/jpsi plus eta_c production in
e+e- annihilation at sqrt{s}=10.6 GeV is calculated in this paper, and an
analytic result is obtained. By choosing proper physical parameters, a K factor
(ratio of NLO to LO) of about 2, which is in agreement with the result in
Ref.\cite{Zhang:2005ch}, is obtained. Our results show that the
Next-Next-to-Leading-Order(NNLO) corrections might be quite large. The plot of
the K-factor vs the center-of-mass energy sqrt{s} shows that it is more
difficult to obtain a convergent result from the perturbative QCD without
resummation of ln(s/m_c) terms as the sqrt{s} becomes larger.Comment: 8 pages, 6 figures, two column
Three-loop planar master integrals for heavy-to-light form factors
We calculate analytically the three-loop planar master integrals relevant for
heavy-to-light form factors using the method of differential equations. After
choosing a proper canonical basis, the boundary conditions are easy to be
determined, and the solution of differential equations is greatly simplified.
The results for seventy-one master integrals at general kinematics are all
expressed in terms of harmonic polylogarithms.Comment: 18 pages, 2 figure
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