arXiv subjects

Josip Trampetic

Publications and source records attributed to Josip Trampetic.

At least 19 recordsLinked to original sources

arXiv2025

Quantum noncommutative ABJM field theory: four- and six-point functions

Following our previous paper Quantum noncommutative ABJM theory: first steps, JHEP {\bf 1804} (2018) 070), in this article we investigate one-loop 1PI four-, and six-point functions by using the component formalism in the Landau gauge and show that they are UV finite and have well-defined $(\theta^{\mu\nu}\rightarrow 0)$ limit. Those results also hold for all one-loop functions which are UV finite by power counting. In summary, taking into account results from previous paper, JHEP {\bf 1804} (2018) 070), and this paper, we conclude that, at least at one-loop order, the NCABJM theory is free from the noncommutative UV and IR instabilities, and that in the limit $\theta^{\mu\nu}\rightarrow 0$ it flows to the ordinary ABJM theory.

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arXiv2020

Light-by-Light Scattering and Spacetime Noncommutativity

The aim of this article is to explore a potential usability of a photon-photon self-interaction from the noncommutative quantum electrodynamics (NCQED) in the case of light-by-light scattering ($γγ\toγγ$) in ultraperipheral Pb+Pb collisions, a reaction measured recently by ATLAS and planned for future experiments in hadron-hadron colliders. We compute the total cross section from both, the full one-loop standard model (SM) and the tree-level NCQED amplitudes, in the equivalent photon approximation with impact parameters, for various noncommutative scales, $\rmΛ_{NC}$, and incoming nuclear spin-energy combinations. We find that NCQED contribution to the cross section has considerable increase at diphoton invariant mass range higher than $\rmΛ_{NC}$, while the SM contribution is strongly suppressed in such region. Our results show that the current ATLAS $\rm\sqrt{s_{NN}} = 5.02$ TeV experiment can only probe $\rmΛ_{NC}<100$ GeV region. On the other hand, future hadron-hadron collider proposals could have the potential to extend to $\rmΛ_{NC}\lesssim 300$ GeV region, making the performance of $\rm Pb+Pb(γγ)\to Pb+Pbγγ$ scattering on testing space-time noncommutativity close to that of the previously proposed photon-photon mode of linear electron-positron collider.

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arXiv2018

Inferring type and scale of noncommutativity from the PTOLEMY experiment

If neutrinos are Dirac particles and their right-handed component can be copiously produced in the early universe, then they could influence a direct observation of the cosmic neutrino background, which, most likely, will come about with the recently proposed PTOLEMY experiment. For the production mechanism of right-handed neutrinos we use a state-of-the-art version of gauge field theory deformed by the spacetime noncommutativity, to disclose by it not only the decoupling temperature for the said neutrino component, but also the otherwise hidden coupling temperature. Considering two relevant processes, the plasmon decay and the neutrino elastic scattering, we study the interplay between the structure of the noncommutativity parameter $θ^{μν}$ (type of noncommutativity) and the reheating temperature after inflation to obtain otherwise elusive upper bound on the scale of noncommutativity $Λ_{\rm NC}$. If PTOLEMY enhanced capture rate is due to spacetime noncommutativity, we verify that a nontrivial maximum upper bound on $Λ_{\rm NC}$ (a way below the Planck scale) emerges for a space-like $θ^{μν}$ and sufficiently high reheating temperature.

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arXiv2018

Quantum noncommutative ABJM theory: first steps

We introduce ABJM quantum field theory in the noncommutative spacetime by using the component formalism and show that it is N=6 supersymmetric. For the U(1)_κ x U(1)_{-κ} case, we compute all one-loop 1PI two and three point functions in the Landau gauge and show that they are UV finite and have well-defined commutative limits theta^{μν} -> 0, corresponding exactly to the 1PI functions of the ordinary ABJM field theory. This result also holds for all one-loop functions which are UV finite by power counting. It seems that the quantum noncommutative ABJM field theory is free from the noncommutative IR instabilities.

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arXiv2018

UV/IR Mixing in Nonassociative Snyder phi^4 Theory

Using a quantization of the nonassociative and noncommutative Snyder phi^4 scalar field theory in a Hermitian realization, we present in this article analytical formulas for the momentum-conserving part of the one-loop two-point function of this theory in D-, 4-, and 3-dimensional Euclidean spaces, which are exact with respect to the noncommutative deformation parameter beta. We prove that these integrals are regularized by the Snyder deformation. These results indicate that the Snyder deformation does partially regularize the UV divergences of the undeformed theory, as it was proposed decades ago. Furthermore, it is observed that different nonassociative phi^4 products can generate different momentum-conserving integrals. Finally most importantly, a logarithmic infrared divergence emerges in one of these interaction terms. We then analyze sample momentum nonconserving integral qualitatively and show that it could exhibit IR divergence too. Therefore infrared divergences should exist, in general, in the Snyder phi^4 theory. We consider infrared divergences at the limit p -> 0 as UV-IR mixings induced by nonassociativity, since they are associated to the matching UV divergence in the zero-momentum limit and appear in specific types of nonassociative phi^4 products. We also discuss the extrapolation of the Snyder deformation parameter beta to negative values as well as certain general properties of one-loop quantum corrections in Snyder phi^4 theory at the zero-momentum limit.

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arXiv2017

Nonassociative Snyder phi4 Quantum Field Theory

In this article we define and quantize a truncated form of the nonassociative and noncommutative Snyder phi^4 field theory using the functional method in momentum space. More precisely, the action is approximated by expanding up to the linear order in the Snyder deformation parameter beta, producing an effective model on commutative spacetime for the computation of the two-, four- and six-point functions. The two- and four-point functions at one loop have the same structure as at the tree level, with UV divergences faster than in the commutative theory. The same behavior appears in the six-point function, with a logarithmic UV divergence and renders the theory unrenormalizable at beta^1 order except for the special choice of free parameters s_1=-s_2. We expect effects from nonassociativity on the correlation functions at beta^1 order, but these are cancelled due to the average over permutations.

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arXiv2017

Spacetime Deformation Effect on the Early Universe and the PTOLEMY Experiment

Using a fully-fledged formulation of gauge field theory deformed by the spacetime noncommutativity, we study its impact on relic neutrino direct detection, as proposed recently by the PTOLEMY experiment. The noncommutative background tends to influence the propagating neutrinos by providing them with a tree-level vector-like coupling to photons, enabling thus otherwise right-handed (RH) neutrinos to be thermally produced in the early universe. Such a new component in the universe's background radiation has been switched today to the almost fully active sea of non-relativistic neutrinos, exerting consequently some impact on the capture on tritium at PTOLEMY. The peculiarities of our nonperturbative approach tend to reflect in the cosmology as well, upon the appearances of the coupling temperature, above which RH neutrinos stay permanently decoupled from thermal environment. This entails the maximal scale of noncommutativity as well, being of order of $10^{-4} M_{Pl}$, above which there is no impact whatsoever on the capture rates at PTOLEMY. The latter represents an exceptional upper bound on the scale of noncommutativity coming from phenomenology.

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arXiv2016

Equivalence and/or quantum duality of the non/supersymmetric noncommutative field theories related by the theta-exact Seiberg-Witten map

In this article we expound a discovery of the quantum equivalence/duality of U(N) noncommutative quantum field theories (NC QFT) related by the theta-exact Seiberg-Witten (SW) maps and at all orders in the perturbation theory with respect to the coupling constant. We show that this proof holds for Super Yang-Mills (SYM) theories with N=0,1,2,4$ supersymmetry. In short, Seiberg-Witten map does commute with the quantization of the U(N) NCQFT independently, with or without supersymmetry.

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arXiv2016

Quantum duality under the theta-exact Seiberg-Witten map

We show that in the perturbative regime defined by the coupling constant, the theta-exact Seiberg-Witten map applied to noncommutative U(N) Yang-Mills --with or without Supersymmetry-- gives an ordinary gauge theory which is, at the quantum level, dual to the former. We do so by using the on-shell DeWitt effective action and dimensional regularization. We explicitly compute the one-loop two-point function contribution to the on-shell DeWitt effective action of the ordinary U(1) theory furnished by the theta-exact Seiberg-Witten map. We find that the non-local UV divergences found in the propagator in the Feynman gauge all but disappear, so that they are not physically relevant. We also show that the quadratic noncommutative IR divergences are gauge-fixing independent and go away in the Supersymmetric version of the U(1) theory.

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arXiv2016

Equivalence of quantum field theories related by the theta-exact Seiberg-Witten map

The equivalence of the noncommutative U(N) quantum field theories related by the theta-exact Seiberg-Witten maps is in this letter proven to all orders in the perturbation theory with respect to the coupling constant. We show that this duality holds for Super Yang-Mills theories with N=0,1,2,4 supersymmetry. A direct check of this equivalence relation is performed by computing the one-loop quantum corrections to the quadratic part of the effective action in the noncommutative U(1) gauge theory with N=0,1,2,4 supersymmetry.

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arXiv2016

Super Yang-Mills and theta-exact Seiberg-Witten map: Absence of quadratic noncommutative IR divergences

We compute the one-loop 1PI contributions to all the propagators of the noncommutative N=1, 2, 4 super Yang-Mills (SYM) U(1) theories defined by the means of the theta-exact Seiberg-Witten (SW) map in the Wess-Zumino gauge. Then we extract the UV divergent contributions and the noncommutative IR divergences. We show that all the quadratic noncommutative IR divergences add up to zero in each propagator.

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arXiv2016

Photon polarization tensor on deformed spacetime: A four-photon-tadpole contribution

In this contribution to the Proceedings of the Corfu Summer Institute 2015 we present our study on photon self-interaction in the deformed U(1) gauge field theory defined via Seiberg-Witten map. We derive the theta-exact expressions for the four photon self-coupling in this theory with a large number of gauge symmetry inspired freedom parameters included. The physical effect of four photon self-coupling is accessed by its contribution to photon polarization tensor via 1-loop four-photon-tadpole-diagram. The four-photon tadpole diagram consists the same tensorial structures as the photon self-interacting bubble diagram we studied before, with however only quadratically IR divergent coefficients. We show that there exists a unique combination of gauge symmetry inspired freedoms which induces full quadratic IR divergence cancellation for arbitrary noncommutative parameter theta once the photon self-interacting bubble and tadpole diagrams are summed over.

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arXiv2015

The theta-exact Seiberg-Witten maps at the e3 order

We study wo distinct theta-exact Seiberg-Witten (SW) map expansions, (I) and (II) respectively, up to the e3 order for the gauge parameter, gauge field and the gauge field strengths of the noncommutative U*(1) gauge theory on the Moyal space. We derive explicitly the closed form expression for the SW map ambiguity between the two and observe the emergence of several new totally commutative generalized star products. We also identify the additional gauge freedoms within each of the e3 order field strength expansions and define corresponding sets of deformation/ratio/weight parameters, (kappa,kappa_i) and (kappa,kappa'_i), for these two SW maps respectively.

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arXiv2014

Two-Point Functions on Deformed Spacetime

We present a review of the one-loop photon ($Π$) and neutrino ($Σ$) two-point functions in a covariant and deformed $\rm U(1)$ gauge-theory on the 4-dimensional noncommutative spaces, determined by a constant antisymmetric tensor $θ^{μν}$, and by a parameter-space $(κ_f,κ_g)$, respectively. For the general fermion-photon $S_f(κ_f)$ and photon self-interaction $S_g(κ_g)$ the closed form results reveal two-point functions with all kind of pathological terms: the UV divergence, the quadratic UV/IR mixing terms as well as a logarithmic IR divergent term of the type $\ln(μ^2(θp)^2)$. In addition, the photon-loop produces new tensor structures satisfying transversality condition by themselves. We show that the photon two-point function in the 4-dimensional Euclidean spacetime can be reduced to two finite terms by imposing a specific full rank of $θ^{μν}$ and setting deformation parameters $(κ_f,κ_g)=(0,3)$. In this case the neutrino two-point function vanishes. Thus for a specific point $(0,3)$ in the parameter-space $(κ_f,κ_g)$, a covariant $θ$-exact approach is able to produce a divergence-free result for the one-loop quantum corrections, having also both well-defined commutative limit and point-like limit of an extended object.

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arXiv2014

Forbidden and invisible Z boson decays in covariant theta-exact noncommutative standard model

The triple neutral gauge boson and direct U(1)_Y-neutrino interactions, being absent in ordinary field theory, can arise quite naturally in noncommutative gauge field theories. Using non-perturbative methods and a Seiberg-Witten map based covariant approach to noncommutative gauge theory, we have found theta-exact expressions for both interactions, thereby eliminating previous restrictions to low-energy phenomena. In particular we obtain for the first time the covariant, theta-exact, triple neutral gauge boson interactions within the noncommutative Standard Model gauge sector including an additional gauge-field deformation freedom. Finally we discuss implications for Z->2gamma and Z->neutrino-pair decays, and show that our results behave quite reasonably throughout all interaction energy scales.

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arXiv2013

Noncommutative geometry in quantum field theory and the cosmogenic neutrino physics at the extreme energies

Analysis of the covariant theta-exact noncommutative (NC) gauge field theory (GFT), inspired by high energy cosmic rays experiments, is performed in the framework of the inelastic neutrino-nucleon scatterings. Next we have have found neutrino two-point function and shows a closed form decoupled from the hard ultraviolet (UV) divergent term, from softened ultraviolet/infrared (UV/IR) mixing term, and from the finite terms as well. For a certain choice of the noncommutative parameter theta which preserves unitarity, problematic UV divergent and UV/IR mixing terms vanish. Non-perturbative modifications of the neutrino dispersion relations are assymptotically independent of the scale of noncommutativity in both, the low and high energy limits and may allow superluminal propagation.

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arXiv2012

High energy cosmic rays experiments inspired by noncommutative quantum field theory

Phenomenological analysis of the covariant theta-exact noncommutative (NC) gauge field theory (GFT), inspired by high energy cosmic rays experiments, is performed in the framework of the inelastic neutrino-nucleon scatterings, plasmon and $Z$-boson decays into neutrino pair, the Big Bang Nucleosynthesis (BBN) and the Reheating Phase After Inflation (RPAI), respectively. Next we have have found neutrino two-point function and shows a closed form decoupling of the hard ultraviolet (UV) divergent term from softened ultraviolet/infrared (UV/IR) mixing term and from the finite terms as well. For a certain choice of the noncommutative parameter theta which preserves unitarity, problematic UV divergent and UV/IR mixing terms vanish. Non-perturbative modifications of the neutrino dispersion relations are assymptotically independent of the scale of noncommutativity in both the low and high energy limits and may allow superluminal propagation.

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arXiv2012

Yukawa couplings and seesaw neutrino masses in noncommutative gauge theory

We consider Yukawa couplings in a theta-exact approach to noncommutative gauge field theory and show that both Dirac and singlet Majorana neutrino mass terms can be consistently accommodated. This shows that in fact the whole neutrino-mass extended standard model on noncommutative spacetime can the formulated in the new nonperturbative (in theta) approach which eliminates the previous restriction of Seiberg-Witten map based theories to low-energy phenomena. Spacetime noncommutativity induced couplings between neutrinos and photons as well as Z-bosons appear quite naturally in the model. We derive relevant Feynman rules for the type I seesaw mechanism.

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