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Related papers: Pomeron loops in zero transverse dimensions

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The most general QCD next-to-leading anomalous-dimension matrix of all possible four-fermion, dimension-six $\Delta F=2$ operators is computed. The results of this calculation can be used in many phenomenological applications, among which…

High Energy Physics - Phenomenology · Physics 2009-10-30 M. Ciuchini , E. Franco , V. Lubicz , G. Martinelli , I. Scimemi , L. Silvestrini

We have computed the complete next-to-next-to-leading order (NNLO) contributions to the splitting functions governing the evolution of unpolarized parton densities in perturbative QCD. Our results agree with all partial results available in…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. Moch , J. A. M. Vermaseren , A. Vogt

The four-pomeron vertex is studied in the perturbative QCD. Its dominating terms of the leading (zeroth and first) orders in the coupling constant and subdominant in the number of colors are constructed. The vertex consists of two terms,…

High Energy Physics - Phenomenology · Physics 2021-12-22 M. A. Braun

We investigate the next-to-next-to-leading order (NNLO) QCD radiative corrections to the pion electromagnetic form factor with large momentum transfer. We explicitly verify the validity of the collinear factorization to two-loop order for…

High Energy Physics - Phenomenology · Physics 2024-08-01 Long-Bin Chen , Wen Chen , Feng Feng , Yu Jia

We evaluate the next-to-next-to-leading order corrections to the hard-scattering amplitude of the photon-to-pion transition form factor. Our approach is based on the predictive power of the conformal operator product expansion, which is…

High Energy Physics - Phenomenology · Physics 2009-11-07 B. Melic , D. Müller , K. Passek-Kumericki

The partons' transverse momentum can be explored with QCD lattice simulations by studying the quasi-transverse-momentum-dependent parton distribution functions (qTMDPDFs), which are factorized in terms of physical TMDPDFs and soft factors…

High Energy Physics - Phenomenology · Physics 2023-12-19 Óscar del Río , Alexey Vladimirov

We compute the next-to-leading order QCD corrections to the ``direct'' part of the spin-dependent cross section for hadron-pair photoproduction. The calculation is performed using largely analytical methods. We present a brief…

High Energy Physics - Phenomenology · Physics 2008-11-26 Christof Hendlmeier , Andreas Schafer , Marco Stratmann

In the framework of Anisotropic Chromodynamics, a non-perturbative realization of QCD, we develop the Low-Nussinov picture of the Pomeron. In this approach all the usual problems of low pT perturbative calculations (infrared divergence) are…

High Energy Physics - Phenomenology · Physics 2009-10-28 Giuliano Preparata , Philip G. Ratcliffe

We have investigated the next-to-next-to-leading order (NNLO) corrections to inclusive hadron production in e^+e^- annihilation and the related parton fragmentation distributions, the `time-like' counterparts of the `space-like'…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Mitov , S. Moch , A. Vogt

We present a calculation of the two-loop splitting functions for the evolution of the twist-2 `transversity' parton densities of transversely polarized nucleons. We study the implications of our results for Soffer's inequality for the case…

High Energy Physics - Phenomenology · Physics 2011-05-05 W. Vogelsang

We present the first calculations of next-to-next-to-next-to-next-to-leading order (N^4LO) contributions to anomalous dimensions of spin-N twist-2 operators in perturbative QCD. Specifically, we have obtained the respective non-singlet…

High Energy Physics - Phenomenology · Physics 2019-02-06 F. Herzog , S. Moch , B. Ruijl , T. Ueda , J. A. M. Vermaseren , A. Vogt

We revisit the calculation of the evolution equations for four unpolarized twist-3 transverse momentum dependent (TMD) parton distribution functions (PDFs) at $\mathcal {O}(\alpha_s)$. Unlike the existing calculations in the literature,…

High Energy Physics - Phenomenology · Physics 2025-07-01 Xue-Tao Liu , Ping-An Liu , Yu-Lu Liu , An-Ping Chen

The factorization theorems for transverse momentum distributions of dilepton/boson production, recently formulated by Collins and Echevarria-Idilbi-Scimemi in terms of well-defined transverse momentum dependent distributions (TMDs), allows…

High Energy Physics - Phenomenology · Physics 2015-06-22 Umberto D'Alesio , Miguel G. Echevarria , Stefano Melis , Ignazio Scimemi

We present results for W-boson production at large transverse momentum at LHC and Tevatron energies. We calculate complete next-to-leading-order (NLO) QCD corrections and higher-order soft-gluon corrections to the differential cross…

High Energy Physics - Phenomenology · Physics 2015-06-03 Nikolaos Kidonakis , Richard J. Gonsalves

By considering semi-inclusive deep-inelastic scattering and the (complementary) $q_T$-spectrum for Drell-Yan lepton pair production we derive the QCD evolution for all the leading-twist transverse momentum dependent distribution and…

High Energy Physics - Phenomenology · Physics 2014-07-10 Miguel G. Echevarria , Ahmad Idilbi , Ignazio Scimemi

Leading-twist operators have a remarkable property that their divergence vanishes in a free theory. Recently it was suggested that this property can be used for an alternative technique to calculate anomalous dimensions of leading-twist…

High Energy Physics - Theory · Physics 2015-09-02 A. N. Manashov , M. Strohmaier

We explore possible extensions of the $t$-channel and $s$-channel unitary model of high energy evolution in zero transverse dimensions appropriate to very high energy/atomic number where the dipole density in a toy hadron is parametrically…

High Energy Physics - Phenomenology · Physics 2022-05-18 A. Kovner , E. Levin , M. Lublinsky

We present an extraction of unpolarized partonic transverse momentum distributions (TMDs) from a simultaneous fit of available data measured in semi-inclusive deep-inelastic scattering, Drell-Yan and Z-boson production. To connect data at…

High Energy Physics - Phenomenology · Physics 2017-08-02 Alessandro Bacchetta , Filippo Delcarro , Cristian Pisano , Marco Radici , Andrea Signori

The QCD-induced $W^\pm \gamma$ production channels in association with two jets are computed at next-to-leading order QCD accuracy. The W bosons decay leptonicly and full off-shell and finite width effects as well as spin correlations are…

High Energy Physics - Phenomenology · Physics 2015-07-15 Francisco Campanario , Matthias Kerner , Le Duc Ninh , Dieter Zeppenfeld

In this proceeding we consider QCD radiative corrections to the production of colourless high-mass systems in hadron collisions. At small transverse momentum the logarithmically-enhanced contributions can be organized to all perturbative…

High Energy Physics - Phenomenology · Physics 2014-07-21 Leandro Cieri