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The problem of entanglement produced by an arbitrary operator is formulated and a related measure of entanglement production is introduced. This measure of entanglement production satisfies all properties natural for such a characteristic.…

Quantum Physics · Physics 2009-11-10 V. I. Yukalov

We obtain predictions accurate at the next-to-leading order in QCD for the production of a generic spin-two particle in the most relevant channels at the LHC: production in association with coloured particles (inclusive, one jet, two jets…

High Energy Physics - Phenomenology · Physics 2017-05-10 Goutam Das , Celine Degrande , Valentin Hirschi , Fabio Maltoni , Hua-Sheng Shao

A method to efficiently compute, in a automatic way, helicity amplitudes for arbitrary scattering processes at leading order in the Standard Model is presented. The scattering amplitude is evaluated recursively through a set of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Costas G. Papadopoulos , Malgorzata Worek

In the framework of the kt-factorization approach, the production and polarization of prompt J/Psi mesons in pp collisions at the LHC energy 7 TeV is studied. Both the direct production mechanism as well as feed-down contributions from…

High Energy Physics - Phenomenology · Physics 2015-05-30 S. P. Baranov , A. V. Lipatov , N. P. Zotov

We discuss the production of polarized hadrons in polarized lepton nucleon interactions and show that the helicity density matrix of the hadron, when measurable, can give information on the spin structure of the nucleon and the spin…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Anselmino , M. Boglione , J. Hansson , F. Murgia

Precision phenomenological studies of high-multiplicity scattering processes at collider experiments present a substantial theoretical challenge and are vitally important ingredients in experimental measurements. Machine learning technology…

High Energy Physics - Phenomenology · Physics 2023-02-20 Ryan Moodie

Quantum discord as a measure of the quantum correlations cannot be easily computed for most of density operators. In this paper, we present a measure of the total quantum correlations that is operationally simple and can be computed…

Quantum Physics · Physics 2016-04-19 Javad Behdani , Seyed Javad Akhtarshenas , Mohsen Sarbishaei

Future hadron collider experiments are expected to record large to huge samples of $t\bar t$ events. The analysis of these data with respect to $t\bar t$ spin-spin correlations requires precise predictions of the production of these quark…

High Energy Physics - Phenomenology · Physics 2009-10-31 W. Bernreuther , A. Brandenburg , Z. G. Si

Precise determination of top-quark pairs is an essential tool for understanding the overall consistency of the standard model (SM) expectations, understanding limited New Physics (NP) models, through spin-spin correlation and polarization…

High Energy Physics - Phenomenology · Physics 2022-01-19 Altan Cakir , Orcun Kolay

The complete density matrix for all polarization configurations in the process B--> t tbar, where B is an off--shell Z or photon and t is the top quark, is calculated numerically including oneloop QCD corrections, i.e. virtual and real…

High Energy Physics - Phenomenology · Physics 2011-09-13 Bodo Lampe

The density matrix of a non-relativistic quantum system, divided into $N$ sub-systems, is rewritten in terms of the set of all partitioned density matrices for the system. For the case where the different sub-systems are distinguishable, we…

Quantum Physics · Physics 2018-12-19 Timothy Cox , Philip C. E. Stamp

The production of massive quarks and leptons in $e^+e^-$ collisions is studied using exact helicity amplitudes. Total cross sections as a function of $y_{\rm cut}$, in both the JADE and the $k_T$ algorithms, are presented and compared with…

High Energy Physics - Phenomenology · Physics 2009-10-22 A. Ballestrero , E. Maina , S. Moretti

Polarization and spin correlation measurements of top quark-antiquark ($t\bar{t}$) pairs provide tests of the standard model, but also new ways to test quantum mechanics with unstable particles at highest energies ever produced in a…

High Energy Physics - Experiment · Physics 2026-01-29 Efe Yazgan

We present the first analysis of top spin polarizations, $t \bar t$ spin correlations, and $t \bar t$ spin entanglement at the LHC in the context of the Standard Model Effective Field Theory, that goes beyond Leading Order QCD accuracy. The…

High Energy Physics - Phenomenology · Physics 2023-02-01 Claudio Severi , Eleni Vryonidou

A measure of entanglement production by quantum operations is suggested. This measure is general, being valid for operations over pure states as well as over mixed states, for equilibrium as well as for nonequilibrium processes. The measure…

Quantum Physics · Physics 2025-08-01 V. I. Yukalov , E. P. Yukalova

A next-to-leading order calculation for single top production including spin-dependent observables requires efficient techniques for the calculation of the relevant loop amplitudes. We discuss the adaption of dimensional regularization, the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Stefan Weinzierl

The description of particles with spin can be attained by using a spin density matrix in high energy reaction. In this paper we present a parametrization of the spin density matrix for spin -3/2 particles in the Cartesian form. Comparing…

High Energy Physics - Phenomenology · Physics 2020-05-05 Jiao Jiao Song , Wan Ling Chang

Measurements of spin correlation in top quark pair production are presented using data collected with the ATLAS detector at the LHC with proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity…

High Energy Physics - Experiment · Physics 2015-01-27 ATLAS Collaboration

We present a numerical implementation for virtual corrections to multi-jet production at Next-to-Leading order. Using the algorithm of generalised unitarity we compute primitive amplitudes from tree-level input. These basic ingredients are…

High Energy Physics - Phenomenology · Physics 2012-01-06 Simon Badger , Benedikt Biedermann , Peter Uwer

Entanglement, a defining feature of quantum mechanics, arises naturally from interactions between molecular systems. Yet the precise nature and quantification of entanglement in the products of molecular collisions and reactions remain…

Atomic Physics · Physics 2026-01-27 Adrien Devolder , Paul Brumer , Timur Tscherbul