4,061 research outputs found

    Two-Loop integrals for CP-even heavy quarkonium production and decays: Elliptic Sectors

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    By employing the differential equations, we compute analytically the elliptic sectors of two-loop master integrals appearing in the NNLO QCD corrections to CP-even heavy quarkonium exclusive production and decays, which turns out to be the last and toughest part in the relevant calculation. The integrals are found can be expressed as Goncharov polylogarithms and iterative integrals over elliptic functions. The master integrals may be applied to some other NNLO QCD calculations about heavy quarkonium exclusive production, like γγQQˉ\gamma^*\gamma\rightarrow Q\bar{Q}, e+eγ+QQˉe^+e^-\rightarrow \gamma+ Q\bar{Q},~and~H/Z0γ+QQˉH/Z^0\rightarrow \gamma+ Q\bar{Q}, heavy quarkonium exclusive decays, and also the CP-even heavy quarkonium inclusive production and decays.Comment: 23 pages, 3 figures, more discussions and references adde

    Measurement-device-independent quantum key distribution with source state errors and statistical fluctuation

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    We show how to calculate the secure final key rate in the four-intensity decoy-state MDI-QKD protocol with both source errors and statistical fluctuations with a certain failure probability. Our results rely only on the range of only a few parameters in the source state. All imperfections in this protocol have been taken into consideration without any unverifiable error patterns.Comment: Published in PRA in March 2017. We present general results for MDIQKD with both intensity error of source and statistical fluctuatio

    NNLO QCD Corrections to γ+ηc(ηb)\gamma + \eta_c(\eta_b) Exclusive Production in Electron-Positron Collision

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    Based on the NRQCD factorization formalism, we calculate the next-to-next-to-leading order QCD corrections to the heavy quarkonium ηc(ηb)\eta_c (\eta_b) production associated with a photon at electron-positron colliders. By matching the amplitudes calculated in full QCD theory to a series of operators in NRQCD, the short-distance coefficients up to NNLO QCD radiative corrections are determined. It turns out that the full set of master integrals that we obtained could be analytically expressed in terms of Goncharov Polylogarithms, Chen's iterated integrals, and elliptic functions, which mostly do not exist in the literature and could be employed in the analyses of other physical processes. In phenomenology, numerical calculations of NNLO K-factors and cross sections of e+eγ+ηc(ηb)e^+e^-\rightarrow \gamma + \eta_c(\eta_b) processes in BESIII and B-factory experiments are performed, which may stand as a test of the NRQCD higher order calculation while confronting to the data.Comment: 12 pages, 5 firue
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