Related papers: Potential NRQED: The Positronium Case
The dominant contribution of the next-to-leading order perturbative QCD corrections to the Upsilon -> X gamma photon energy spectrum for photon energies w ~ m_b alpha_s can be obtained trivially from the knowledge of the corresponding…
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…
Effective Lagrangians were originally used only at the tree level as so-called phenomenological Lagrangians since they were in general non-renormalizable. Today they are treated as effective field theories valid below a characteristic…
This contribution contains the first numerical computation of the complete set of relativistic corrections of relative order $v^{2}$ for electric dipole (E1) transitions in heavy quarkonium; in particular, for the processes $\chi_{bJ}(1P)…
We obtain information on the QED photon amplitudes at high orders in perturbation theory starting from known results on the QED effective Lagrangian in a constant electric field. A closed-form all-order result for the weak field limit of…
We analyze the end-point region of the photon spectrum in semi-inclusive radiative decays of very heavy quarkonium (m alpha_s^2 >> Lambda_QCD). We discuss the interplay of the scales arising in the Soft-Collinear Effective Theory, m,…
We compute the complete imaginary part of the NRQCD Lagrangian at order 1/M^4 in the heavy-quark mass expansion, which includes center of mass operators, and at order alpha_s^2 in the matching coefficients. We also compute the imaginary…
In the heavy quark limit, properties of heavy mesons and doubly heavy baryons are related by heavy quark-diquark symmetry. This problem is reanalyzed in the framework of Non-Relativistic QCD (NRQCD). We introduce a novel method for deriving…
Canonically, the quantum electrodynamic radiative corrections in bound systems have been evaluated in photon energy regularization, i. e. using a noncovariant overlapping parameter that separates the high-energy relativistic scales of the…
The heavy quarkonium static potential is discussed within the framework of potential NRQCD. Some quantitative statements are made in the kinematical situation $mv >> \Lambda_{\rm QCD}$ at the level of accuracy of the next-to-leading order…
Potential-NRQCD offers an effective-theory based approach to heavy-quark physics. While meson Q-anti_Q computations are tractable in pure alpha_s-perturbation theory, more complex many-body quark systems transcend it. A possibility…
Effective field theories such as Heavy Quark Effective Theory (HQET) and Non Relativistic Quantum Chromo-(Electro-) dynamics NRQCD (NRQED) are indispensable tools in controlling the effects of the strong interaction. The increasing…
We review recent theoretical developments in heavy quarkonium physics from the point of view of Effective Field Theories of QCD. We discuss Non-Relativistic QCD and concentrate on potential Non-Relativistic QCD. Our main goal will be to…
QCD nonrelativistic effective field theories (NREFT) are the modern and most suitable frame to describe heavy quarkonium properties. Here I summarize few relevant concepts and some of the interesting physical applications (spectrum, decays,…
We show that some NRQCD colour-octet matrix elements can be written in terms of (derivatives of) wave functions at the origin and non-perturbative universal constants once the factorization between the soft and ultrasoft scale is achieved…
Taking into account the negative searches for New Physics at the LHC, electroweak effective theories are appropriate to deal with current energies. Tracks of new, higher scales can be studied through next-to leading order corrections of the…
We review some recent developments on non-relativistic effective field theories for heavy quark-antiquark systems and how they can bring a well founded connection between QCD and potential models.
The orthopositronium decay to three photons is studied in the phase-space region where one of the photons has an energy comparable to the relative three-momentum of the e+e- system (w ~ m alpha). The NRQED computation in this regime shows…
The subject of low energy photon-photon scattering is considered in arbitrary dimensional space-time and the interaction is widened to include scattering events involving an arbitrary number of photons. The effective interaction Lagrangian…
We present a theroretical treatment of electric dipole (E1) transitions of heavy quarkonia based on effective field theories. Within the framework of potential nonrelativistic QCD (pNRQCD) we derive the complete set of relativistic…