21 research outputs found

    BTB \rightarrow T transition form factors in light-cone sum rules

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    We present a new calculation of the semileptonic tree-level and flavor-changing neutral current form factors describing BB-meson transitions to tensor mesons T=D2,K2,a2,f2T=D_2^*,K_2^*,a_2,f_2 (JP=2+J^{P}=2^{+}). We employ the QCD Light-Cone Sum Rules approach with BB-meson distribution amplitudes. We go beyond the leading-twist accuracy and provide analytically, for the first time, higher-twist corrections for the two-particle contributions up to twist four terms. We observe that the impact of higher twist terms to the sum rules is noticeable. We study the phenomenological implications of our results on the radiative BK2γ{B} \to K_2^{*}\gamma and semileptonic BD2νˉ{B} \to D_2^* \ell {\bar \nu}_\ell, BK2+{B} \to K_2^{*}\ell^+\ell^- decays.Comment: 31 pages, 5 figures, 4 tables, references added, slight modifications on the text, numerical results revised using a new fit function, main conclusions unchanged. Version accepted for publication in PR

    Towards NNLO accuracy for epsilon '/epsilon

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    The quantity ε/ε\varepsilon'/\varepsilon measures direct CP violation in Kaon decays. Recent SM predictions show a 2.9σ2.9\sigma tension with data, with the theoretical uncertainty dominating. As rapid progress on the lattice is bringing nonperturbative long-distance effects under control, a more precise knowledge of short-distance contributions is needed. We describe the first NNLO results for ε/ε\varepsilon'/\varepsilon and discuss future prospects, as well as issues of scheme dependence and the separation of perturbative and nonperturbative effects. Finally we also comment on the solution of the renormalisation-group evolution in one of the talks at this conference and present the correct solution.Comment: 8 pages, Proceedings of the Kaon 2016 Conferenc

    Erratum: The Belle II Physics Book (Progress of Theoretical and Experimental Physics (2019) 2019 (123C01) DOI: 10.1093/ptep/ptz106)

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    The Belle II Physics Book

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    We present the physics program of the Belle II experiment, located on the intensity frontier SuperKEKB e+ee^+e^- collider. Belle II collected its first collisions in 2018, and is expected to operate for the next decade. It is anticipated to collect 50/ab of collision data over its lifetime. This book is the outcome of a joint effort of Belle II collaborators and theorists through the Belle II theory interface platform (B2TiP), an effort that commenced in 2014. The aim of B2TiP was to elucidate the potential impacts of the Belle II program, which includes a wide scope of physics topics: B physics, charm, tau, quarkonium, electroweak precision measurements and dark sector searches. It is composed of nine working groups (WGs), which are coordinated by teams of theorist and experimentalists conveners: Semileptonic and leptonic B decays, Radiative and Electroweak penguins, phi_1 and phi_2 (time-dependent CP violation) measurements, phi_3 measurements, Charmless hadronic B decay, Charm, Quarkonium(like), tau and low-multiplicity processes, new physics and global fit analyses. This book highlights "golden- and silver-channels", i.e. those that would have the highest potential impact in the field. Theorists scrutinised the role of those measurements and estimated the respective theoretical uncertainties, achievable now as well as prospects for the future. Experimentalists investigated the expected improvements with the large dataset expected from Belle II, taking into account improved performance from the upgraded detector.Comment: 689 page

    Diabetik sistopatide sistometri

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    TEZ151Tez (Uzmanlık) -- Çukurova Üniversitesi, Adana, 1983.Kaynakça (s. [69]-72) var.72 s. : res. ; 31 cm.

    The double radiative B̄

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    Next-to-leading logarithmic QCD contribution of the electromagnetic dipole operator to B̅ →Xsγγ

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    We calculate the set of O(alpha_s) corrections to the double differential decay width dGamma_77/(ds_1*ds_2) for the process B -> X_s gamma gamma originating from diagrams involving the electromagnetic dipole operator O_7. The kinematical variables s_1 and s_2 are defined as s_i=(p_b - q_i)^2/m_b^2, where p_b, q_1, q_2 are the momenta of b-quark and two photons. While the (renormalized) virtual corrections are worked exactly for a certain range of s_1 and s_2, we retain in the gluon bremsstrahlung process only the leading power w.r.t. the (normalized) hadronic mass s_3=(p_b-q_1-q_2)^2/m_b^2 in the underlying triple differential decay width dGamma_77/(ds_1*ds_2*ds_3). The double differential decay width, based on this approximation is free of infrared- and collinear singularities when combining virtual- and bremsstrahlung corrections. The corresponding results are obtained analytically. When retaining all powers in s_3, the sum of virtual- and bremstrahlung corrections contains uncanceled 1/epsilon singularities (which are due to collinear photon emission from the s-quark) and other concepts, which go beyond perturbation theory, like parton fragmentation functions of a quark or a gluon into a photon, are needed which is beyond the scope of our paper.Comment: 22 pages, 6 figure

    Improved analysis of the (

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