Galilean covariant effective theory for bound states of heavy mesons

2018 ◽  
Vol 33 (30) ◽  
pp. 1850180
Author(s):  
L. M. Abreu ◽  
M. de Montigny ◽  
E. S. Santos ◽  
D. F. C. A. Silva
Keyword(s):  
Bound States ◽  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Heavy Meson ◽  
Effective Theory ◽  
Heavy Mesons ◽  
Interaction Terms ◽  
Effective Lagrangian ◽  
Dimensional Space Time ◽  
Covariant Version

In this work we formulate the Galilei-covariant version of an effective theory containing nonrelativistic heavy mesons and pions as degrees of freedom. This manifestly Galilean covariant framework is based on a five-dimensional space–time that has been used in the description of covariant nonrelativistic physics. In this context, effective Lagrangian is introduced without ambiguities, containing kinetic and interaction terms that are naturally Galilean invariant. The leading-order scattering amplitudes and the properties of possible heavy-meson bound states are calculated and discussed.

scholarly journals Lorentz-violating effects in three-dimensional QED

2014 ◽  
Vol 29 (22) ◽  
pp. 1450112 ◽  
Author(s):  
R. Bufalo
Keyword(s):  
Quantum Electrodynamics ◽  
Lagrangian Density ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Space Time ◽  
Nonminimal Coupling ◽  
Coupling Term ◽  
Interaction Terms ◽  
Higher Derivative ◽  
Dimensional Space Time

Inspired in discussions presented lately regarding Lorentz-violating interaction terms in B. Charneski, M. Gomes, R. V. Maluf and A. J. da Silva, Phys. Rev. D86, 045003 (2012); R. Casana, M. M. Ferreira Jr., R. V. Maluf and F. E. P. dos Santos, Phys. Lett. B726, 815 (2013); R. Casana, M. M. Ferreira Jr., E. Passos, F. E. P. dos Santos and E. O. Silva, Phys. Rev. D87, 047701 (2013), we propose here a slightly different version for the coupling term. We will consider a modified quantum electrodynamics with violation of Lorentz symmetry defined in a (2+1)-dimensional space–time. We define the Lagrangian density with a Lorentz-violating interaction, where the space–time dimensionality is explicitly taken into account in its definition. The work encompasses an analysis of this model at both zero and finite-temperature, where very interesting features are known to occur due to the space–time dimensionality. With that in mind, we expect that the space–time dimensionality may provide new insights about the radiative generation of higher-derivative terms into the action, implying in a new Lorentz-violating electrodynamics, as well the nonminimal coupling may provide interesting implications on the thermodynamical quantities.

scholarly journals Gravitational Theory Without the Cosmological Constant Problem

1997 ◽  
Vol 12 (32) ◽  
pp. 2421-2424 ◽  
Author(s):  
E. I. Guendelman ◽  
A. B. Kaganovich
Keyword(s):  
Cosmological Constant ◽  
Degrees Of Freedom ◽  
Vacuum Energy ◽  
Dimensional Space ◽  
Realistic Model ◽  
Gravitational Theory ◽  
Space Time ◽  
Higher Dimensional Space Time ◽  
Higher Dimensional ◽  
Dimensional Space Time

We develop a gravitational theory where the measure of integration in the action principle is not necessarily [Formula: see text] but it is determined dynamically through additional degrees of freedom. This theory is based on the demand that such measure respects the principle of "non-gravitating vacuum energy" which states that the Lagrangian density L can be changed to L + const. without affecting the dynamics. Formulating the theory in the first-order formalism we get as a consequence of the variational principle a constraint that enforces the vanishing of the cosmological constant. The most realistic model that implements these ideas is realized in a six or higher dimensional space–time. The compactification of extra dimensions into a sphere gives the possibility of generating scalar masses and potentials, gauge fields and fermionic masses. It turns out that the remaining four-dimensional space–time must have effective zero cosmological constant.

scholarly journals Partition Function in One, Two, and Three Spatial Dimensions from Effective Lagrangian Field Theory

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Christoph P. Hofmann
Keyword(s):  
Partition Function ◽  
Degrees Of Freedom ◽  
Spatial Dimension ◽  
Lagrangian Method ◽  
Point Of View ◽  
Low Energy ◽  
Effective Theory ◽  
Goldstone Bosons ◽  
Effective Lagrangian ◽  
Spatial Dimensions

The systematic effective Lagrangian method was first formulated in the context of the strong interaction; chiral perturbation theory (CHPT) is the effective theory of quantum chromodynamics (QCD). It was then pointed out that the method can be transferred to the nonrelativistic domain—in particular, to describe the low-energy properties of ferromagnets. Interestingly, whereas for Lorentz-invariant systems the effective Lagrangian method fails in one spatial dimension (ds=1), it perfectly works for nonrelativistic systems in ds=1. In the present brief review, we give an outline of the method and then focus on the partition function for ferromagnetic spin chains, ferromagnetic films, and ferromagnetic crystals up to three loops in the perturbative expansion—an accuracy never achieved by conventional condensed matter methods. We then compare ferromagnets in ds=1, 2, 3 with the behavior of QCD at low temperatures by considering the pressure and the order parameter. The two apparently very different systems (ferromagnets and QCD) are related from a universal point of view based on the spontaneously broken symmetry. In either case, the low-energy dynamics is described by an effective theory containing Goldstone bosons as basic degrees of freedom.

scholarly journals ON UNITARITY OF A LINEARIZED YANG–MILLS FORMULATION FOR MASSLESS AND MASSIVE GRAVITY WITH PROPAGATING TORSION

2010 ◽  
Vol 25 (26) ◽  
pp. 4911-4932
Author(s):  
ROLANDO GAITAN DEVERAS
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Massive Gravity ◽  
Dynamical Variable ◽  
General Covariance ◽  
Yang Mills ◽  
Dimensional Space Time ◽  
Perturbative Regime ◽  
Massive Theory ◽  
Extended Theories

A perturbative regime based on contortion as a dynamical variable and metric as a (classical) fixed background, is performed in the context of a pure Yang–Mills formulation for gravity in a (2+1)-dimensional space–time. In the massless case, we show that the theory contains three degrees of freedom and only one is a nonunitary mode. Next, we introduce quadratical terms dependent on torsion, which preserve parity and general covariance. The linearized version reproduces an analogue Hilbert–Einstein–Fierz–Pauli unitary massive theory plus three massless modes, two of them represents nonunitary ones. Finally, we confirm the existence of a family of unitary Yang–Mills-extended theories which are classically consistent with Einstein's solutions coming from nonmassive and topologically massive gravity. The unitarity of these Yang–Mills-extended theories is shown in a perturbative regime. A possible way to perform a nonperturbative study is remarked.

scholarly journals THE LOW ENERGY EFFECTIVE LAGRANGIAN FOR PHOTON INTERACTIONS IN ANY DIMENSION

1996 ◽  
Vol 11 (02) ◽  
pp. 253-269 ◽  
Author(s):  
A. RITZ ◽  
R. DELBOURGO
Keyword(s):  
Dimensional Space ◽  
Effective Interaction ◽  
Bernoulli Polynomial ◽  
Weak Field ◽  
Space Time ◽  
Low Energy ◽  
Time Dimension ◽  
Effective Lagrangian ◽  
Dimensional Space Time ◽  
Photon Interactions

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 for these processes in QED has been determined in a manifestly invariant form. This generalization resolves the structure of the weak field Euler-Heisenberg Lagrangian and indicates that the component invariant functions have coefficients related not only to the space-time dimension but also to the coefficients of the Bernoulli polynomial.

scholarly journals Light-front heavy-quark effective theory and heavy-meson bound states

1995 ◽  
Vol 52 (5) ◽  
pp. 2915-2925 ◽  
Author(s):  
Chi-Yee Cheung ◽  
Wei-Min Zhang ◽  
Guey-Lin Lin
Keyword(s):  
Heavy Quark ◽  
Bound States ◽  
Heavy Meson ◽  
Light Front ◽  
Effective Theory ◽  
Heavy Quark Effective Theory

scholarly journals ON THE POSSIBLE EXISTENCE OF NEW FERMIONIC DEGREES OF FREEDOM IN D = 6

2003 ◽  
Vol 8 (2) ◽  
pp. 155-164
Author(s):  
P. Miškinis
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Physical Object ◽  
Space Time ◽  
Dimensional Space Time ◽  
Fermionic Fields

The bispinors formed by quaternion in D = 6 dimensional space‐time are proposed to be treated as new fermionic fields. The gauge nonabelian field is formulated by the quaternions. A new kind of physical object, an extended relativistic quaternionic membrane in D = 6, is discussed.

COVARIANT QUANTIZATION OF MASSLESS SUPERPARTICLE IN 4-DIMENSIONAL SPACE-TIME: TWISTOR APPROACH

1989 ◽  
Vol 04 (19) ◽  
pp. 1827-1837 ◽  
Author(s):  
M.S. PLYUSHCHAY
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Space Time ◽  
Extended Model ◽  
Covariant Quantization ◽  
Covariant Operator ◽  
Dimensional Space Time ◽  
Penrose Twistor

With the help of Penrose twistor approach by introducing the auxiliary “Stückelberg” degrees of freedom, the “extended” model of massless superparticle is constructed in 4-dimensional space-time, which is equivalent to the original Brink-Schwarz model. The covariant operator quantization of the obtained system is performed in the cases of N=1 and extended supersymmetries. It is shown that there are three independent schemes of quantization of the system at even N, one of which becomes anomalous at odd N.

scholarly journals MAGNETIC ZN SYMMETRY IN 2+1 DIMENSIONS

2002 ◽  
Vol 17 (16) ◽  
pp. 2113-2164 ◽  
Author(s):  
A. KOVNER
Keyword(s):  
Degrees Of Freedom ◽  
Gauge Theories ◽  
Chiral Symmetry Breaking ◽  
Low Energy ◽  
Effective Theory ◽  
Spontaneous Breaking ◽  
Range Interaction ◽  
Strongly Coupled ◽  
Effective Lagrangian ◽  
Magnetic Symmetry

This review describes the role of magnetic symmetry in (2+1)-dimensional gauge theories. In confining theories without matter fields in fundamental representation the magnetic symmetry is spontaneously broken. Under some mild assumptions, the low-energy dynamics is determined universally by this spontaneous breaking phenomenon. The degrees of freedom in the effective theory are magnetic vortices. Their role in confining dynamics is similar to that played by pions and σ in the chiral symmetry breaking dynamics. I give an explicit derivation of the effective theory in (2+1)-dimensional weakly coupled confining models and argue that it remains qualitatively the same in strongly coupled (2+1)-dimensional gluodynamics. Confinement in this effective theory is a very simple classical statement about the long range interaction between topological solitons, which follows (as a result of a simple direct classical calculation) from the structure of the effective Lagrangian. I show that if fundamentally charged dynamical fields are present the magnetic symmetry becomes local rather than global. The modifications to the effective low energy description in the case of heavy dynamical fundamental matter are discussed. This effective Lagrangian naturally yields a bag like description of baryonic excitations. I also discuss the fate of the magnetic symmetry in gauge theories with the Chern–Simons term.

scholarly journals The fate of the axial anomaly in a finite field theory

2020 ◽  
Vol 35 (05) ◽  
pp. 2050025
Author(s):  
Pierre Grangé ◽  
Jean-François Mathiot ◽  
Ernst Werner
Keyword(s):  
Degrees Of Freedom ◽  
Gauge Theories ◽  
Dimensional Space ◽  
Decay Amplitude ◽  
Vector Current ◽  
Leading Order ◽  
Axial Anomaly ◽  
Internal Loop ◽  
Lagrange Formulation ◽  
Dimensional Space Time

The conservation of the vector current and the axial anomaly responsible for the [Formula: see text] decay amplitude are obtained in leading order within the Taylor–Lagrange formulation of fields considered as operator-valued distributions. As for gauge theories, where this formulation eliminates all divergences and preserves gauge symmetry, it is shown that the different contributions can be evaluated directly in four-dimensional space–time, with no restrictions whatsoever on the four-momentum of the internal loop, and without the need to introduce any additional nonphysical degrees of freedom like Pauli–Villars fields. We comment on the similar contributions responsible for the decay of the Higgs boson into two photons.

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