Light dark matter candidates in intense laser pulses I: paraphotons and fermionic minicharged particles

Abstract

Polarimetric experiments driven by the strong field of a circularly polarized laser wave can become a powerful tool to limit the parameter space of not yet detected hidden-photons and minicharged particles associated with extra U(1) gauge symmetries. We show how the absorption and dispersion of probe electromagnetic waves in the vacuum polarized by such a background are modified due to the coupling between the visible U(1)-gauge sector and these hypothetical degrees of freedom. The results of this analysis reveal that the regime close to the two-photon reaction threshold can be a sensititive probe of these hidden particles. Parameters of modern laser systems are used to estimate the projected sensitivities on the corresponding coupling constants in regions where experiments driven by dipole magnets are less constricted. The role played by a paraphoton field is analyzed via a comparison with a model in which the existence of minicharges is assumed only. For both scenarios is found that the most stringent exclusion limit occurs at the lowest threshold mass; this one being determined by a certain combination of the field frequencies and dictated by energy momentum balance of the photo-production of a pair of minicharged particles. The dependencies of the observables on the laser attributes as well as on the unknown particle parameters are also analyzed.

New experimental approaches in the search for axion-like particles

“…The kinetic mixing angle between the hidden and standard photon is naturally small -values χ h ∼ 10 −13 − 10 −2 are typically predicted in the literature [127][128][129][130][131][132][133][134][135][136][137][138]. The mixing leads to a number of observable consequences in laboratory experiments [139][140][141][142][143][144][145][146][147][148][149][150][151][152][153][154][155], astrophysics [156][157][158][159][160][161][162][163][164] and cosmology [165][166][167][168][169][170][171][172][173]…”

Light dark matter candidates in intense laser pulses II: the relevance of the spin degrees of freedom

“…Conversely, the dispersion equations resulting from the poles associated with the transverse modes Λ ± concide with those found previously in Refs. [67][68][69]:…”

“…[67]. Later, in part I of this series [68], a further step was performed by investigating the optical effects resulting from an extended model containing fermionic MCPs and a hidden photon field. There we revealed that, at moderate intensities 10 16 W/cm 2 as provided by the nanosecond frontends of the PHELIX laser [72] and LULI system [73], high-precision polarimetric measurements could improve the existing laboratory upper bounds for the coupling constant of MCPs by an order of magnitude for masses of the order of m ∼ eV.…”

“…Recent theoretical studies on the birefringence and dichroism of the vacuum in an external magnetic field can be found in[27][28][29].2 See[58,59,67,68] for new insights on the vacuum refractive indices in plane-wave fields…”

ALP production through non-linear Compton scattering in intense fields

“…For studies involving calculations similar to those presented in this paper we refer the reader to [99–102] Given the increasing availability of high-intensity lasers from recent and upcoming experiments [103–109] the study of QED in intense fields to observe both SM and BSM phenomena is of crucial importance. So far, using high-intensity lasers to probe BSM phenomena has mainly be studied theoretically, and then through the coupling to ALPs [110–116] and mini-charged particles [117–119] to photons. In this paper we study interactions involving electrons and ALPs in intense electromagnetic fields, focusing on the production of ALPs via Compton scattering from electrons in intense laser pulses.…”