Related papers: The Perturbative Pole Mass in QCD
The $\Lambda(1405)$ baryon is difficult to detect in experiment, absent in many quark model calculations, and supposedly manifested through a two-pole structure. Its uncommon properties made it subject to numerous experimental and…
The definition of the quark-antiquark static potential is given within an effective field theory framework. The leading infrared divergences of the static singlet potential in perturbation theory are explicitly calculated.
We analyze lattice QCD results on the equation of state in terms of infinitely many non-interacting massive ideal gas components. We find that the entire pressure-temperature curve can be described by a temperature independent mass…
We estimate the presently unknown constant in the 4-loop relation between the quark pole mass and the MSbar mass, by requiring stability of the perturbative prediction for E_tot(r)=2m_pole+V_QCD(r) in the intermediate-distance region. The…
We show that the renormalization factor relating the renormalization group invariant quark masses to the bare quark masses computed in lattice QCD can be determined non-perturbatively. The calculation is based on an extension of a…
Systematic approaches to building up gauge invariant descriptions of charged fields, such as electrons or quarks, are described. Physically relevant descriptions must then be singled out from a multiplicity of possibilities and to this end…
Two flavor QCD involves three independent mass parameters for which non-perturbative effects are not universal. This precludes matching lattice and perturbative results for non-degenerate quarks and eliminates a vanishing up quark mass as a…
We consider the equation of state of QCD at high density and zero temperature in perturbation theory to first order in the coupling constant $\alpha_s$. We compute the thermodynamic potential including the effect of a non-vanishing mass for…
Creutz [hep-ph/0312225] has argued that nonperturbative effects in QCD lead to an additive ambiguity in the up quark mass, and that "this calls into question the acceptability of attempts to solve the strong CP problem via a vanishing mass…
Detailed analysis shows that the phase of a complex mass term of a quark does not violate CP, while the QCD vacuum angle can naturally be set equal to zero. There is no strong CP problem and no need for axions or similar speculative…
The CP violating Dashen phase in QCD is predicted by chiral perturbation theory to occur when the up-down quark mass difference becomes sufficiently large at fixed down-quark mass. Before reaching this phase, all physical hadronic masses…
The freedom one has in constructing locally gauge invariant charged fields in gauge theories is analyzed in full detail and exploited to construct, in QED, an electron field whose two-point function W(p), up to the fourth order in the…
Considered as a function of the quark mases, two-flavor QCD depends on three parameters, including one that is CP violating. As the masses vary to unphysical values, regions of both first- and second-order phase transitions are expected.…
We present the light-quark mass dependence of the $\Lambda(1405)$ resonance at leading order in a renormalizable framework of covariant chiral effective field theory. The meson-baryon scattering amplitudes, which are obtained by solving the…
The potential between infinitely heavy quarks in a color singlet state is of fundamental importance in QCD. While the confining long distance part is inherently non-perturbative, the short-distance (Coulomb-like) regime is accessible…
Effects of heavy sea quarks on the low energy physics are described by an effective theory where the expansion parameter is the inverse quark mass, 1/$M$. At leading order in 1/$M$ (and neglecting light quark masses) the dependence of any…
As a model for nonideal behavior in the equation of state of QCD at high density, we consider cold quark matter in perturbation theory. To second order in the strong coupling constant, $\alpha_s$, the results depend sensitively on the…
We discuss the gauge invariance of quark-quark potential in QCD in the perturbative treatment, and show that the gauge dependence of the quark-gluon interaction cannot be eliminated. Therefore, the quark-quark potential cannot properly be…
We present a pedagogical review of certain exact theoretical results concerning the physics of an imaginary world where one quark or more are deprived of their masses.
We describe the effects of the strange quark mass and of the color and electric neutrality on the superconducing phases of QCD.