Search results for "computations"

From loops to trees by-passing Feynman's theorem

2008

We derive a duality relation between one-loop integrals and phase-space integrals emerging from them through single cuts. The duality relation is realized by a modification of the customary +i0 prescription of the Feynman propagators. The new prescription regularizing the propagators, which we write in a Lorentz covariant form, compensates for the absence of multiple-cut contributions that appear in the Feynman Tree Theorem. The duality relation can be applied to generic one-loop quantities in any relativistic, local and unitary field theories. %It is suitable for applications to the analytical calculation of %one-loop scattering amplitudes, and to the numerical evaluation of %cross-section…

Single bottom quark production in kT-factorisation

2015

Journal of High Energy Physics 2015.9 (2015): 123 reproduced by permission of Scuola Internazionale Superiore di Studi Avanzati (SISSA)

Heavy quark impact factor in kT-factorization

2013

We present the calculation of the finite part of the heavy quark impact factor at next-to-leading logarithmic accuracy in a form suitable for phenomenological studies such as the calculation of the cross-section for single bottom quark production at the LHC within the kT-factorization scheme.

Perturbative quark mass corrections to the tau hadronic width

1998

15 páginas, 3 figuras, 2 tablas.-- arXiv:hep-ph/9804462v1

Theoretical study of a hydration mechanism in an enaminone pro-drug prototype

2003

Enaminones may act as pro-drugs releasing via proton-catalyzed hydrolysis a primary amine, which may be an actual drug. A hydration mechanism of prototype enaminone (2-propenal-3-amine) has been subjected to quantum chemical studies. All involved compounds were investigated in a search for the most likely reactive form. Results revealed that the proposed reaction pathway is thermodynamically possible.

Two-Loop Planar Corrections to Heavy-Quark Pair Production in the Quark-Antiquark Channel

2009

We evaluate the planar two-loop QCD diagrams contributing to the leading color coefficient of the heavy-quark pair production cross section, in the quark-antiquark annihilation channel. We obtain the leading color coefficient in an analytic form, in terms of one- and two-dimensional harmonic polylogarithms of maximal weight 4. The result is valid for arbitrary values of the Mandelstam invariants s and t, and of the heavy-quark mass m. Our findings agree with previous analytic results in the small-mass limit and numerical results for the exact amplitude.

Design of carborane molecular architectures with electronic structure computations: From endohedral and polyradical systems to multidimensional netwo…

2009

11 pags, 6 figs. -- 19th International Conference on Physical Organic Chemistry (ICPOC-19) 13–18 July 2008, Santiago de Compostela, Spain

Weak intermolecular interactions promote blue luminescence of protonated 2,2′-dipyridylamine salts

2014

In this work we demonstrate that protonation and π-stacking can be exploited to convert non-luminescent 2,2′-dipyridylamine into blue-emitting derivatives. We have synthesized a series of luminescent 2,2′-dipyridylamine (dpa) salts, i.e., (dpaH)X·nSolv (dpa = 2,2′-dipyridylamine, X = HF2, n = 0.5, Solv = H2O 1; X = Cl, n = 2, Solv = H2O 2; X = Br, n = 2, Solv = H2O 3; X = I n = 1, Solv = H2O 4a; X = I n = 1, Solv = CHCl34b), (dpaH)2[SiF6]·H2O 5 and (dpaH)X (X = I36; SbF67; BF48) and characterized their emission properties, both in the solid-state and in solution. To rationalize our observations and relate the luminescence properties to the structure in the solid state and in solution, we ha…

Tendencies in ABO3 Perovskite and SrF2, BaF2 and CaF2 Bulk and Surface F-Center Ab Initio Computations at High Symmetry Cubic Structure

2021

This research was partly funded by the Latvian Council of Science project No. LZP‐ 2020/2‐0009 (for R. Eglitis), as well as the ERAF Project No. 1.1.1.1/18/A/073. We express our gratitude for the financial support from Latvian–Ukraine cooperation Project No. Latvia–Ukraine LV‐ UA/2021/5. The Institute of Solid State Physics, University of Latvia (Latvia), as the Centre of Excellence has received funding from the European Unions Horizon 2020 Framework Pro‐ gramme H2020‐WIDESPREAD01‐2016‐2017‐Teaming Phase2 under Grant Agreement No. 739508, project CAMART2.

On computation in the limit by non-deterministic Turing machines

1974