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Related papers: Four-Quark Effective Operators at Hadron Colliders

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Extensions of the Standard Model which involve a new scale, $\Lambda$, may, for energies sufficiently small compared to this new scale, be expressed in terms of operators with energy dimension greater than four. The coefficients of just…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. Hagiwara , S. Matsumoto , R. Szalapski

We write down a minimal basis for dimension-six gauge-invariant four-fermion operators, with some operator replacements with respect to previous ones which make it simpler for calculations. Using this basis we classify all four-fermion…

High Energy Physics - Phenomenology · Physics 2011-07-13 J. A. Aguilar-Saavedra

We present calculations of matrix elements of 4-quark operators in the pion and in the nucleon extracted from quenched Monte Carlo simulations at beta = 6.0 using Wilson fermions. These operators are relevant for higher-twist effects. We…

High Energy Physics - Lattice · Physics 2008-11-26 S. Capitani , M. Gockeler , R. Horsley , B. Klaus , W. Kurzinger , D. Petters , D. Pleiter , P. E. L. Rakow , S. Schaefer , A. Schafer , G. Schierholz

We discuss how to consistently use Effective Field Theories (EFTs) to set universal bounds on heavy-mediator Dark Matter at colliders, without prejudice on the model underlying a given effective interaction. We illustrate the method for a…

High Energy Physics - Phenomenology · Physics 2015-05-18 Davide Racco , Andrea Wulzer , Fabio Zwirner

We establish constraints on the dimension-six four-heavy-quark operators in the Standard Model Effective Field Theory (SMEFT) by synthesising LHC measurements of top-quark and single-Higgs production with electroweak precision observables.…

High Energy Physics - Phenomenology · Physics 2025-07-03 Stefano Di Noi , Hesham El Faham , Ramona Gröber , Marco Vitti , Eleni Vryonidou

We show how heavy quark effective theory, including 1/M corrections, may be matched onto dynamical quark models by making a specific choice of K,m and v in the p=mv+K expansion. We note that Wigner rotations of heavy quark spins arise at…

High Energy Physics - Phenomenology · Physics 2010-11-01 Frank Close , Zhenping Li

The top quark will be extensively studied at future muon colliders. The threshold cross section can be measured precisely, and the small beam energy spread is especially effective at making the measurement useful. We report on all the…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. S. Berger , B. L. Winer

The spin and flavor symmetries of the heavy quark effective theory are employed to discuss the exclusive cross sections for pair production of heavy mesons in photon-photon collision. The ratios of the exclusive cross sections for heavy…

High Energy Physics - Phenomenology · Physics 2009-10-22 S. Y. Choi , H. S. Song

We show that the amplitudes for B decays into two light mesons at leading order in soft-collinear effective theory are factorized to all orders in alpha_s. We construct gauge-invariant four-quark operators by employing the effective…

High Energy Physics - Phenomenology · Physics 2009-11-10 Junegone Chay , Chul Kim

Many theories, from Supersymmetry to models of Strong Electroweak Symmetry Breaking, look at the production of four top quarks as an interesting channel to evidentiate signals of new physics beyond the Standard Model. The production of…

High Energy Physics - Phenomenology · Physics 2012-07-19 G. Bevilacqua , M. Worek

In the heavy quark effective theory, hadronic matrix elements of currents between two hadrons containing a heavy quark are expanded in inverse powers of the heavy quark masses, with coefficients that are functions of the kinematic variable…

High Energy Physics - Phenomenology · Physics 2009-10-22 Adam F. Falk , Matthias Neubert

We match the non-relativistic quark model, with both flavor dependent and flavor independent effective quark-quark interactions, to the spin-flavor operator basis of the 1/Nc expansion for the L=1 non-strange baryons. We obtain analytic…

Nuclear Theory · Physics 2016-02-10 Cintia Willemyns , Carlos Schat

I review recent progresses in heavy quarks physics on the lattice. I focus on decay constants and form factors relevant for the extraction of CKM matrix elements from experimental data. B-\bar{B} mixing is also discussed. In the last part…

High Energy Physics - Lattice · Physics 2009-01-06 Michele Della Morte

Effective field theory techniques are used to describe the interaction of heavy hadrons in a model independent way. Predictability is obtained by exploiting the symmetries of QCD. Heavy hadron chiral perturbation theory is reviewed and used…

High Energy Physics - Phenomenology · Physics 2007-05-23 Iain W. Stewart

We study possible theoretical deviations from SM in top quark physics which alter the decay properties of the top quark. Using effective filed theory techniques we parametrize the effects of potential NP of scales well above the electroweak…

High Energy Physics - Phenomenology · Physics 2012-10-19 Jure Drobnak

Starting from the Fock space representation of hadron bound states in a quark model, a change of representation is implemented by a unitary transformation such that the composite hadrons are redescribed by elementary-particle field…

High Energy Physics - Phenomenology · Physics 2010-11-19 D. Hadjimichef , G. Krein , S. Szpigel , J. S. da Veiga

Many scenarios of beyond the Standard Model (BSM) physics give rise to new top-philic interactions that can be probed at proton machines such as the Large Hadron Collider through a variety of production and decay modes. On the one hand,…

High Energy Physics - Phenomenology · Physics 2023-08-16 Anisha , Oliver Atkinson , Akanksha Bhardwaj , Christoph Englert , Wrishik Naskar , Panagiotis Stylianou

We have calculated the perturbative corrections to all the structure functions in the semileptonic decays of a heavy quark. Assuming an arbitrary gluon mass as a technical tool allowed to obtain in parallel all the BLM corrections. We…

High Energy Physics - Phenomenology · Physics 2008-11-26 Nikolai Uraltsev

Achievements in the heavy quark theory over the last decade are reviewed, with the main emphasis put on dynamical methods which quantify nonperturbative effects via application of the Operator Product Expansion. These include the total weak…

High Energy Physics - Phenomenology · Physics 2016-11-23 Nikolai Uraltsev

We consider processes which produce final state hadrons whose energy is much greater than their mass. In this limit interactions involving collinear fermions and gluons are constrained by a symmetry, and we give a general set of rules for…

High Energy Physics - Phenomenology · Physics 2011-05-05 Christian W. Bauer , Iain W. Stewart
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