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In a scalar field theory, when the tree level potential admits broken symmetry ground states, the quantum corrections to the static effective potential are complex. (The imaginary part is a consequence of an instability towards phase…

High Energy Physics - Theory · Physics 2009-10-22 D. Boyanovsky , H. J. de Vega

We find that perturbation theory fails to describe the short range static potential as obtained from quenched lattice simulations, at least for source separations r > 1/(6 GeV). The difference between the non-perturbatively determined…

High Energy Physics - Phenomenology · Physics 2009-10-31 Gunnar S. Bali

The first data on bottom quark production in p-pbar collisions at 1.96 TeV have recently been obtained by the CDF collaboration. These data probe the region of pt~0, providing a new invaluable input on the issue of the compatibility between…

High Energy Physics - Phenomenology · Physics 2010-04-06 M. Cacciari , S. Frixione , M. L. Mangano , P. Nason , G. Ridolfi

We study field strength correlators in presence of a static quark-antiquark pair by use of lattice methods. The lattice data have been acquired recently in the context of a determination of relativistic corrections to the static interquark…

High Energy Physics - Lattice · Physics 2014-11-17 Gunnar S. Bali , Nora Brambilla , Antonio Vairo

We show that the perturbatively-improved gluon action for QCD, once it is tadpole-improved, gives accurate results even with lattice spacings as large as 0.4~fm. {\em No\/} tuning of the couplings is required. Using this action and lattice…

High Energy Physics - Lattice · Physics 2009-10-28 M. Alford , W. Dimm , G. Hockney , P. Lepage , P. Mackenzie

In this talk we discuss a number of ChPT calculations relevant for lattice QCD. These include the finite volume corrections at two-loop order for masses and decay constants. The second part is about hadronic vacuum polarization where we…

High Energy Physics - Lattice · Physics 2016-11-21 Johan Bijnens , Johan Relefors

The complete NNLO QCD corrections to the total cross section $\sigma(e^+e^- \to Z*,\gamma*\to t\bar t)$ in the kinematic region close to the top-antitop threshold are calculated by solving the corresponding Schroedinger equations exactly in…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. H. Hoang , T. Teubner

In addition to the inclusive cross sections discussed within the QCD-parton model, in the regime of multiple parton interactions, different and more exclusive cross sections become experimentally viable and may be suitably measured. Indeed,…

High Energy Physics - Phenomenology · Physics 2015-05-13 G. Calucci , D. Treleani

The chiral phase transition at finite temperature T and/or chemical potential $\mu$ is studied using the QCD-like theory with a variational approach. The ``QCD-like theory'' means the improved ladder approximation with an infrared cutoff in…

High Energy Physics - Phenomenology · Physics 2009-10-31 O. Kiriyama , M. Maruyama , F. Takagi

QCD inequalities are derived for the masses of mesons and baryons containing a single heavy quark using the heavy quark effective field theory. A rigorous lower bound is obtained for the $\bar\Lambda$ parameters of the heavy quark effective…

High Energy Physics - Phenomenology · Physics 2011-01-25 Zachary Guralnik , Aneesh V. Manohar

We present in detail the calculation of the O(alpha_s^3)inclusive total cross section for the process (p pbar-> t tbar h) in the Standard Model, at the Tevatron center-of-mass energy sqrt(s_H)=2 TeV. The next-to-leading order QCD…

High Energy Physics - Phenomenology · Physics 2009-11-07 L. Reina , S. Dawson , D. Wackeroth

I shall review the present status of Tevatron QCD studies, focusing on the production of jets, vector bosons, photons and heavy quarks. In general there is good agreement between the results of current calculational tools and the…

High Energy Physics - Experiment · Physics 2007-05-23 John Womersley

We analyze the production of a single top squark at hadron colliders: ppbar/pp -> \tilde{t}_1 + X. The total cross sections and the transverse momentum distributions are presented in next-to-leading order QCD. The higher-order corrections…

High Energy Physics - Phenomenology · Physics 2009-10-31 T. Plehn

The talk summarises a calculation of the two-point functions for $\Delta S=1$ current-current and QCD-penguin operators, as well as for the $\Delta S=2$ operator, at the next-to-leading order. The size of the gluonic corrections to…

High Energy Physics - Phenomenology · Physics 2009-10-28 Matthias Jamin

For the first time, we determine the complete spin- and momentum-dependent order v^2 corrections to the static interquark potential from simulations of QCD in the valence quark approximation at inverse lattice spacings of 2-3 GeV. A new…

High Energy Physics - Lattice · Physics 2014-11-17 Gunnar S. Bali , Klaus Schilling , Armin Wachter

For precision studies with QCD observables at colliders, higher order perturbative corrections are often mandatory. For exclusive observables, like jet cross sections or differential distributions, these corrections were until recently only…

High Energy Physics - Phenomenology · Physics 2008-12-30 T. Gehrmann

We study the sensitivity of the dilepton production cross section to higher twist terms. A method for calculating the resummed cross section is introduced in moment space, where the leading higher twist terms can be easily parametrized and…

High Energy Physics - Phenomenology · Physics 2009-09-25 Lyndon Alvero

We construct an improved version of nonrelativistic QCD for use in lattice simulations of heavy quark physics, with the goal of reducing systematic errors from all sources to below 10\%. We develop power counting rules to assess the…

High Energy Physics - Lattice · Physics 2010-11-01 G. P. Lepage , L. Magnea , C. Nakhleh , U. Magnea , K. Hornbostel

The measurement of the $t\bar{t}$ inclusive production cross section $\sigma_{t\bar{t}}$ is crucial to probe QCD predictions, constrain new physic scenarios, proton PDFs, top quark pole mass, $\alpha_S$ and many other parameters from the…

High Energy Physics - Experiment · Physics 2018-01-11 Juan R. González Fernández

The beam energy spread is a major issue in future attempts to study the $t\overline{t}$ threshold at $e^+e^-$ colliders. Muon colliders are expected to naturally have narrow band beams making them an ideal place to study the excitation…

High Energy Physics - Phenomenology · Physics 2008-02-03 M. S. Berger
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