Related papers: Limits on the Non-commutativity Scale
Lorentz-invariant non-commutative QED (NCQED) is constructed such that it should be a part of Lorentz-invariant non-commutative standard model (NCSM), a subject to be treated in later publications. Our NCSM is based on Connes' observation…
The energy spectrum of neutrino-induced upward-going muons in MACRO was analysed in terms of special relativity principles violating effects, keeping standard mass-induced atmospheric neutrino oscillations as the dominant source of nu_mu…
Upon a suggestion of Kostelecky et al., we have performed a test of CPT and Lorentz invariance from the microwave spectroscopy of muonium. New terms in their standard model extension violating CPT and Lorentz symmetry would appear as…
This paper addresses the question of whether there are 4D Lorentz invariant unitary quantum field theories with scale invariance but not conformal invariance. An important loophole in the arguments of Luty-Polchinski-Rattazzi and…
We consider an effective model formed by usual QED (minimal coupling) with the addition of a nonminimal Lorentz violating interaction (proportional to a fixed 4-vector $b_\mu$) which may radiatively generate both CPT even and odd terms in…
It is pointed out that the space noncommutativity parameters $theta^{\mu \nu}$ in noncommutative gauge theory can be considered as a set of superselection parameters, in analogy with the theta-angle in ordinary gauge theories. As such, they…
New developments on the symmetries of non-relativistic field theoretical models on the non commutative plane are reviewed. It is shown in particular that Galilean invariance strongly restricts the admissible interactions. Moreover, if a…
In the context of the nonminimal Standard-Model Extension a special subset of the CPT-even higher-dimensional operators in the photon sector is discussed from a quantum-field theoretical point of view. The modified dispersion laws, photon…
The influence of higher dimensions in noncommutative field theories is considered. For this purpose, we analyze the bosonic sector of a recently proposed 6 dimensional SU(3) orbifold model for the electroweak interactions. The corresponding…
In the context of conventional quantum field theory, we present a general Lorentz-violating extension of the minimal SU(3) x SU(2) x U(1) standard model including CPT-even and CPT-odd terms. It can be viewed as the low-energy limit of a…
Some extensions of the Standard Model of Particle Physics allow for Lorentz invariance and Charge-Parity-Time (CPT)-invariance violations. In the neutrino sector strong constraints have been set by neutrino-oscillation and time-of-flight…
We give a complete classification of mass dimension five Lorentz-non-invariant interactions composed from the Standard Model fields, using the effective field theory approach. We identify different classes of Lorentz violating operators,…
A constant antisymmetric 2-tensor can arise in general relativity with spontaneous symmetry breaking or in field theories formulated in a noncommutative space-time. In this work, the one-loop contribution of a nonstandard $WW\gamma$ vertex…
In this note we investigate a new type of non-commutative field theory based on a constant skew-symmetric three-form parameter. In 3+1 dimensions such a three-form parameter can be viewed as a short-distance regulator which nevertheless…
We present a unified, SI-consistent framework to constrain minimal SME coefficients $a_\mu$ and $b_\mu$ using magnetically confined two-dimensional electron systems under a uniform magnetic field. Working in the nonrelativistic…
We study phenomenological consequences of a noncommutative extension of the standard model in the theta-expanded approach at the ILC. We estimate the sensitivity of the ILC for the noncommutative scale Lambda_NC. Comparing with earlier…
The CPT-even abelian gauge sector of the Standard Model Extension is represented by the Maxwell term supplemented by $(K_{F})_{\mu\nu\rho\sigma}F^{\mu\nu}F^{\rho\sigma}$, where the Lorentz-violating background tensor,…
We study the recently proposed Lorentz-violating dispersion relation for fermions and show that it leads to two distinct cubic operators in the momentum. We compute the leading order terms that modify the non-relativistic equations of…
In this paper we deal with the issue of Lorentz symmetry breaking in quantum field theories formulated in a non-commutative space-time. We show that, unlike in some recente analysis of quantum gravity effects, supersymmetry does not protect…
Lorentz and CPT violation in hadronic physics must be tied to symmetry violations at the underlying quark and gluon level. Chiral perturbation theory provides a method for translating novel operators that may appear in the Lagrange density…