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Related papers: The QCD Scale in the Heavy Quark Expansion

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We discuss the role of the U(1) axial symmetry for the phase structure of QCD at finite temperature. In particular, supported by recent lattice results, we analyse a scenario in which a U(1)-breaking condensate survives across the chiral…

High Energy Physics - Phenomenology · Physics 2009-11-10 Enrico Meggiolaro

The construction of heavy quark effective field theory (HqEFT) is extended to arbitrary order in both expansion parameters $\alpha_s$ and $1/m_q$. Matching conditions are discussed for the general case, and it is verified that this approach…

High Energy Physics - Phenomenology · Physics 2013-11-13 W. Kilian , T. Mannel

We derive commensurate scale relations which relate perturbatively calculable QCD observables to each other, including the annihilation ratio, the heavy quark potential, tau decay, and radiative corrections to structure function sum rules.…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stanley J. Brodsky , Hung Lung Lu

In the framework of QCD sum rules one uses a scheme, allowing one to apply the conditions of both nonrelativistic heavy quark motion inside mesons and independence of nonsplitting nS-state density on the heavy quark flavours. In the leading…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. V. Kiselev

We discuss the QCD corrections to the large-$m_t$ electroweak contributions to $\Delta r$ and to the process $Z\to b \bar b$ as two of the most representative examples. This needs the construction of an effetive field theory below the top…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Peris

In supersymmetric theories, the main decay modes of scalar quarks are decays into quarks plus charginos or neutralinos, if the gluinos are heavy enough. We calculate the O($\alpha_s$) QCD corrections to these decay modes in the minimal…

High Energy Physics - Phenomenology · Physics 2011-01-27 A. Djouadi , W. Hollik , C. Junger

We review recent results on the phase structure of QCD and bulk QCD thermodynamics. In particular we discuss how universal critical scaling related to spontaneous breaking of the chiral symmetry manifests itself in recent lattice QCD…

High Energy Physics - Lattice · Physics 2017-10-11 Christian Schmidt , Sayantan Sharma

The light scalar meson spectrum is studied using the improved ladder QCD with the UA(1) breaking Kobayashi-Maskawa-'t Hooft interaction by solving the Schwinger-Dyson and Bethe-Salpeter equations. The dynamically generated…

High Energy Physics - Phenomenology · Physics 2009-11-10 Toru Umekawa , Kenichi Naito , Makoto Oka , Makoto Takizawa

In the domain wall fermion formulation, chiral symmetry breaking in full QCD is expected to fall exponentially with the length of the extra dimension. We measure the chiral symmetry breaking due to a finite extra dimension in two ways,…

High Energy Physics - Lattice · Physics 2015-06-25 George R. Fleming

In order to study the QCD chiral critical point we investigate Binder Cumulants of the chiral condensate. The results were obtained from simulations of 3 and 2+1 flavors of standard staggered fermions and 3 flavors of p4 improved staggered…

High Energy Physics - Lattice · Physics 2009-11-07 Ch. Schmidt , C. R. Allton , S. Ejiri , S. J. Hands , O. Kaczmarek , F. Karsch , E. Laermann

We apply heavy-quark effective theory to separate long- and short-distance effects of heavy quarks in lattice gauge theory. In this approach, the inverse heavy-quark mass and the lattice spacing are treated as short distances, and their…

High Energy Physics - Lattice · Physics 2014-11-17 Junpei Harada , Shoji Hashimoto , Ken-Ichi Ishikawa , Andreas S. Kronfeld , Tetsuya Onogi , Norikazu Yamada

We draw an analogy between the chiral extrapolation of lattice QCD calculations from large to small quark masses and the interpolation between the large mass (weak field) and small mass (strong field) limits of the Euler--Heisenberg QED…

High Energy Physics - Theory · Physics 2017-08-23 Gerald V. Dunne , Anthony W. Thomas , Stewart V. Wright

I report on recent developments in the heavy-quark effective theory and its application to $B$ meson decays. The parameters of the effective theory, the spin-flavor symmetry limit, and the leading symmetry-breaking corrections to it are…

High Energy Physics - Phenomenology · Physics 2007-05-23 Matthias Neubert

derivation of the effective lagrangian for non-relativistic quantum chromodynamics and the heavy quarks effective field theory is given. Our calculation provides of a simple and systematic method of calculation of the full off shell…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. Gamboa , S. Lepe an L. Vergara

The coupling constants of D*D$\pi$ and B*B$\pi$ strong interactions are computed in the effective quark model with chiral symmetry incorporating Heavy quark effective theory (HQET) and Chiral perturbation theory at the quark level with…

High Energy Physics - Phenomenology · Physics 2022-03-02 A. N. Ivanov , N. I. Troitskaya

Scalar mesons are a key expression of the strong physics regime of QCD and the role condensates, particularly $<q{\bar q}>$, play in breaking chiral symmetry. What new insights have been provided by recent experiments on $D, D_s$ and…

High Energy Physics - Phenomenology · Physics 2009-11-11 M. R. Pennington

In a local gauge-invariant theory with massless Dirac fermions a symmetry of the Lorentz-invariant fermion charge is larger than a symmetry of the Lagrangian as a whole. While the Dirac Lagrangian exhibits only a chiral symmetry, the…

High Energy Physics - Phenomenology · Physics 2019-01-14 L. Ya. Glozman

Light and heavy-light (b) hadrons are among the most interesting and among the most challenging quantities to calculate in lattice gauge theory. One would like to avoid discretization effects from very heavy quarks and to calculate chiral…

High Energy Physics - Lattice · Physics 2007-05-23 A. Ali Khan

After discussing the intrinsic ambiguity in determining the light quark mass ratio $m_u/m_d$, we reexamine the recent proposal that this ambiguity can be resolved by applying the QCD multipole expansion for the heavy quarkonium decays. It…

High Energy Physics - Phenomenology · Physics 2008-11-26 Kiwoon Choi

A distinctive feature of the presence of spontaneous chiral symmetry breaking in QCD is the condensation of low modes of the Dirac operator near the origin. The rate of condensation must be equal to the slope of (Mpi^2 Fpi^2)/2 with respect…

High Energy Physics - Phenomenology · Physics 2015-03-25 Georg P. Engel , Leonardo Giusti , Stefano Lottini , Rainer Sommer