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The loop level flavor changing neutral currents transitions of the $\Sigma_{b}\to n l^+l^-$ and $\Sigma_{c}\to p l^+l^-$ are investigated in full QCD and heavy quark effective theory in the light cone QCD sum rules approach. Using the most…

High Energy Physics - Phenomenology · Physics 2014-11-20 K. Azizi , M. Bayar , M. T. Zeyrek

We report on recent progress in calculating the three loop QCD corrections of the heavy flavor contributions in deep--inelastic scattering and the massive operator matrix elements of the variable flavor number scheme. Notably we deal with…

High Energy Physics - Phenomenology · Physics 2023-06-30 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. Goedicke , A. von Manteuffel , C. Schneider , K. Schönwald

We present the analytic expressions for the color-planar contributions to the heavy-light form factors at three loops in perturbative QCD. These form factors play an important role in the precision predictions of various observables in top…

High Energy Physics - Phenomenology · Physics 2023-08-24 Sudeepan Datta , Narayan Rana , V. Ravindran , Ratan Sarkar

We calculate the next-to-leading order (NLO) quantum chromodynamics (QCD) corrections to $\gamma+\gamma\to \eta_c+c+\bar{c}$, $\gamma+\gamma\to \eta_b+b+\bar{b}$ and $\gamma+\gamma\to B_c+b+\bar{c}$ processes in the framework of…

High Energy Physics - Phenomenology · Physics 2022-05-25 Hao Yang , Zi-Qiang Chen , Cong-Feng Qiao

The decay B_s -> mu^+ mu^- in the Standard Model is generated by the well-known W-box and Z-penguin diagrams that give rise to an effective quark-lepton operator Q_A at low energies. We compute QCD corrections of order alpha_s^2 to its…

High Energy Physics - Phenomenology · Physics 2014-03-18 Thomas Hermann , Mikolaj Misiak , Matthias Steinhauser

In the framework of nonrelativistic QCD (NRQCD) factorization, we compute both the polarized and the unpolarized decay widths for the processes $\eta_b(\chi_{bJ})\to J/\psi J/\psi$, accurate up to next-to-next-to-leading-order (NNLO) in…

High Energy Physics - Phenomenology · Physics 2023-10-13 Yu-Dong Zhang , Xiao-Wei Bai , Feng Feng , Wen-Long Sang , Ming-Zhen Zhou

We calculate three-loop corrections to correlation functions of heavy-quark currents in the low- and high-energy regions. We present 30 coefficients both in the low-energy and the high-energy expansion of the scalar and the vector…

High Energy Physics - Phenomenology · Physics 2015-05-30 A. Maier , P. Marquard

In this talk \footnote{Presented at ICHEP'98, Vancouver, CA, July 1998}, we present a recently suggested way on how to analytically incorporate massive threshold effects into observables calculated in massless QCD. No matching is required…

High Energy Physics - Phenomenology · Physics 2007-05-23 Michael Melles

In this paper, we evaluate, up to QCD next-to-next-to-next-to-leading order, the $B_c^*$ decay constant, which, within the nonrelativistic QCD (NRQCD) framework, is factorized as the product of the short-distance coefficient (SDC) and the…

High Energy Physics - Phenomenology · Physics 2023-03-16 Wen-Long Sang , Hong-Fei Zhang , Ming-Zhen Zhou

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 mass $M$. We exploit the…

High Energy Physics - Phenomenology · Physics 2014-11-17 K. G. Chetyrkin , M. Steinhauser

We present the first complete next-to-next-to-next-to-leading-order calculation of the matching coefficients that link unpolarized flavor non-singlet parton distribution functions with lattice QCD computable correlation functions. By using…

High Energy Physics - Phenomenology · Physics 2024-10-11 Chen Cheng , Li-Hong Huang , Xiang Li , Zheng-Yang Li , Yan-Qing Ma

We present a next-to-leading-order (NLO) analysis of the rare radiative decay $\eta_b \to J/\psi\gamma$, a flavor-changing transition between bottomonium and charmonium, within the framework of non-relativistic QCD (NRQCD). We…

High Energy Physics - Phenomenology · Physics 2026-03-17 Hao Yang , Lin Zuo , Bingwei Long

In the present paper, we make a detailed analysis for the QCD corrections to the electroweak $\rho$ parameter by applying the principle of maximum conformality (PMC). As a comparison, we show that under the conventional scale setting, we…

High Energy Physics - Phenomenology · Physics 2014-06-04 Sheng-Quan Wang , Xing-Gang Wu , Jian-Ming Shen , Hua-Yong Han , Yang Ma

We compute the leading mass corrections to the high-energy behavior of the massive quark vector form factor to three loops in QCD in the double-logarithmic approximation.

High Energy Physics - Phenomenology · Physics 2017-06-28 Tao Liu , Alexander A. Penin , Nikolai Zerf

We calculate the one-loop QCD corrections for the decay of an off-shell vector boson with vector couplings into two pairs of quarks of equal or unequal flavours keeping all orders in the number of colours. These matrix elements are relevant…

High Energy Physics - Phenomenology · Physics 2008-11-26 E. W. N. Glover , D. J. Miller

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

The decay width of $Z^0$ to $B_c$ meson is evaluated at the next-to-leading order(NLO) accuracy in strong interaction. Numerical calculation shows that the NLO correction to this process is remarkable. The quantum…

High Energy Physics - Phenomenology · Physics 2015-05-28 Cong-Feng Qiao , Li-Ping Sun , Rui-Lin Zhu

The next-to-leading order (NLO) quantum chromodynamics (QCD) corrections for $\chi_{cJ}(^3P_J^{[1]},^3S_1^{[8]})$, the P-wave charmoniums inclusive production at $B$ factories are calculated utilizing the non-relativistic QCD (NRQCD)…

High Energy Physics - Phenomenology · Physics 2015-06-03 Long-Bin Chen , Jun Jiang , Cong-Feng Qiao

We calculate the two-loop QCD mixing of the dimension-five flavor-changing operators that arise in the Standard Model after integrating out the $W$, $Z$ and Higgs bosons and the top-quark, i.e.~the mixing among gluonic and photonic magnetic…

High Energy Physics - Phenomenology · Physics 2011-07-19 M. Misiak , M. Muenz

We compute corrections of order $\alpha_s^3$ to the decay $b \to c \ell \bar\nu$ taking into account massive charm quarks. In the on-shell scheme large three-loop corrections are found. However, in the kinetic scheme the three-loop…

High Energy Physics - Phenomenology · Physics 2021-07-16 Matteo Fael , Kay Schönwald , Matthias Steinhauser