Effects of aCPT-even and Lorentz-violating nonminimal coupling on electron-positron scattering

Abstract

We propose a new CPT -even and Lorentz-violating nonminimal coupling between fermions and Abelian gauge fields involving the CPT -even tensor (KF ) µναβ of the standard model extension. We thus investigate its effects on the cross section of the electron-positron scattering by analyzing the process e + + e − → µ + + µ − . Such a study was performed for the parity-odd and parity-even nonbirefringent components of the Lorentz-violating (KF ) µναβ tensor. Finally, by using experimental data available in the literature, we have imposed upper bounds as tight as 10 −12 (eV) −1 on the magnitude of the CPT -even and Lorentz-violating parameters while nonminimally coupled.

Perturbative unitarity and higher-order Lorentz symmetry breaking

“…Limits on the Lorentz violating coefficients of nonrenormalizable operators have been obtained from astrophysical observations [5] and synchrotron radiation [6]; see also [7]. Recently, extensions with higher-order couplings have also been proposed [8].…”

Einstein-Hilbert graviton modes modified by the Lorentz-violating bumblebee field

“…This theoretical framework has inspired a large number of investigations in the last several years, encompassing fermion systems [12][13][14][15][16][17][18][19][20], CPT-probing experiments [21][22][23][24][25][26][27], the electromagnetic CPT-and Lorentzodd term [28]- [41], the CPT-even and Lorentz-odd gauge sector and its interactions with fermions [42][43][44][45][46][47][48][49][50][51], [52][53][54][55][56][57]. Recent investigations involving higher dimensional operators [58][59][60], its possible connections with LV theories [61][62][63][64][65][66], and nonminimal couplings [67][68][69][70]…”

He–McKellar–Wilkens-type effect, quantum holonomies and Aharonov–Bohm-type effect for bound states from the Lorentz symmetry breaking effects

“…We show that analogues of the Anandan quantum phase [17,18] and the He-McKellar-Wilkens effect [19] can be obtained from the effects of the violation of the Lorentz symmetry. Recently, a non-minimal coupling has been introduced in the fermionic sector whose property is that a tensor governs the Lorentz symmetry violation in the CPT-even gauge sector of the Standard Model Extension [28,29]. The coupling suggested allow us to write the Dirac equation in the form:…”