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Related papers: A Variable Flavour Number Scheme at NNLO

200 papers

We investigate the uncertainties of the heavy-quark parton distribution functions in the variable flavor number scheme. Because the charm- and bottom-quark parton distribution functions (PDFs) are constructed predominantly from the gluon…

High Energy Physics - Phenomenology · Physics 2008-11-26 Z. Sullivan , P. M. Nadolsky

We discuss a general framework for the inclusion of heavy quark mass contributions to deep-inelastic structure functions and their perturbative matching to structure functions computed in variable-mass schemes. Our approach is based on the…

High Energy Physics - Phenomenology · Physics 2015-05-18 Stefano Forte , Eric Laenen , Paolo Nason , Juan Rojo

Heavy neutrinos at the TeV scale have been searched for at the LHC in the context of left-right models, under the assumption that they couple to the electron, the muon, or both. We show that current searches are also sensitive to heavy…

High Energy Physics - Phenomenology · Physics 2012-05-25 J. A. Aguilar-Saavedra , F. Deppisch , O. Kittel , J. W. F. Valle

Using the available data on deeply virtual Compton scattering (DVCS) off protons and utilizing neural networks enhanced by the dispersion relation constraint, we determine six out of eight leading Compton form factors in the valence quark…

High Energy Physics - Phenomenology · Physics 2020-07-02 Marija Cuic , Kresimir Kumericki , Andreas Schafer

We study the next-to-next-to-leading order (NNLO) evolution of flavour singlet parton densities and structure functions in massless perturbative QCD. Present information on the corresponding three-loop splitting functions is used to derive…

High Energy Physics - Phenomenology · Physics 2009-10-31 W. L. van Neerven , A. Vogt

We obtain a soft plus virtual approximation to the NNLO QCD contributions to the top-pair invariant mass distribution at hadron colliders. It is valid up to corrections of order m_t^2/M^2, with M the pair invariant mass. This is currently…

High Energy Physics - Phenomenology · Physics 2015-06-16 Andrea Ferroglia , Ben D. Pecjak , Li Lin Yang

Heavy-flavour jets enter many of today's collider studies, yet NLO predictions for these quantities are subject to large uncertainties, larger than the corresponding experimental errors. We propose a new, infrared safe definition of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Giulia Zanderighi

Flavor hierarchies emerge from a single hierarchical parameter $B$ in a one-flavon Froggatt--Nielsen scheme. Fixing $B=5.357$ from charged-lepton ratios ($m_e:m_\mu:m_\tau\!\propto\!\epsilon^5:\epsilon^2:1$, $\epsilon=1/B$), we reproduce…

High Energy Physics - Phenomenology · Physics 2026-03-03 Vernon Barger

We analyse the possible presence of New Physics (NP) in the Flavour Sector and evaluate its potential for solving the tension between the experimental values of $\AJPKs$ and $\BTNu$ with respect to the Standard Model (SM) expectations.…

High Energy Physics - Phenomenology · Physics 2015-06-05 F. J. Botella , G. C. Branco , M. Nebot

The twist-2 heavy-quark and antiquark distributions, as defined in the variable flavor number scheme, turn out to be different due to QCD corrections from three-loop onward. This is caused by terms containing the color factor $d_{abc}…

High Energy Physics - Phenomenology · Physics 2025-12-16 A. Behring , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider , K. Schönwald

The calculations of $Z + b{\bar b}$ tagged jet production performed in the four- and five-flavour schemes allow for detailed comparison of the heavy flavour structure of collinear and transverse momentum dependent (TMD) parton distributions…

High Energy Physics - Phenomenology · Physics 2021-06-21 H. Jung , S. Taheri Monfared

In this QCD analysis, we investigate the impact of recent measurements of heavy-flavor charm and beauty cross sections data sets on the simultaneous determination of Parton Distribution Functions (PDFs) and the strong coupling,…

High Energy Physics - Phenomenology · Physics 2017-11-20 A. Vafaee , A. Khorramian

The subject of this thesis is the construction of an approximation for the next-to-next-to-next-to leading order (N^3LO) deep inelastic scattering (DIS) massive coefficient function of the gluon for F2 in heavy quark pair production.…

High Energy Physics - Phenomenology · Physics 2024-01-23 Niccolò Laurenti

It is common, in both theoretical and experimental studies, to separately discuss quark and gluon jets. However, even at parton level, widely-used jet algorithms fail to provide an infrared safe way of making this distinction. We examine…

High Energy Physics - Phenomenology · Physics 2009-01-07 Andrea Banfi , Gavin P. Salam , Giulia Zanderighi

Flavour symmetries are fundamental tools in the search for an explanation to the flavour puzzle: fermion mass hierarchies, the neutrino mass ordering, the differences between the mixing matrices in the quark and lepton sector, can all find…

High Energy Physics - Phenomenology · Physics 2015-03-12 Luca Merlo

In this thesis, I study the phase diagram of dense, locally neutral three-flavor quark matter as a function of the strange quark mass, the quark chemical potential, and the temperature, employing a general nine-parameter ansatz for the gap…

Nuclear Theory · Physics 2007-05-23 Stefan B. Ruester

We extend a recent global analysis of nucleon parton distributions carried out at next-to-leading order (NLO) in the MSbar scheme to provide distributions in the so-called DIS scheme. We pay particular attention to the translation of the…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. D. Martin , R. G. Roberts , W. J. Stirling , R. S. Thorne

We consider application of domain wall fermions to quarks with relatively heavy masses, aiming at precision calculations of charmed meson properties. Preliminary results for a few basic quantities are presented.

High Energy Physics - Lattice · Physics 2019-08-14 N. Yamada

We present the first calculation of a fully-unintegrated parton distribution (beam function) at next-to-next-to-leading order (NNLO). We obtain the fully-differential beam function for quark-initiated processes by matching it onto standard…

High Energy Physics - Phenomenology · Physics 2015-01-05 Jonathan R. Gaunt , Maximilian Stahlhofen

Heavy-flavor particles are excellent probes of the properties of the hot and dense nuclear medium created in the relativistic heavy-ion collisions. Heavy-flavor transport coefficients in the quark-gluon plasma (QGP) stage of the collisions…

Nuclear Theory · Physics 2020-01-10 Weiyao Ke