Review on Dark Photon

Abstract

Abstract. e + e − collider experiments at the intensity frontier are naturally suited to probe the existence of a force beyond the Standard Model between WIMPs, the most viable dark matter candidates. The mediator of this new force, known as dark photon, should be a new vector gauge boson very weakly coupled to the Standard Model photon. No significant signal has been observed so far. I will report on current limits set on the coupling factor ε 2 between the photon and the dark photon by e + e − collider experiments.

Dark-sector physics in the search for the rare decays $$K^+\rightarrow \pi ^+ \nu {\bar{\nu }}$$ and $$K_L\rightarrow \pi ^0 \nu {\bar{\nu }}$$

“…Moreover, to directly constrain the magnetic dipole interactions, we approximate the diagonal couplings ρ dd = ρ ss = 1 in Eq. (16), which is also in agreement with the minimal flavor violation hypothesis. The comparison requires the introduction of the full effective Lagrangian [38][39][40][41] inclusive of the new operators induced by the dark sector.…”

“…Among the many models for the dark sector (see, for example, the review articles in [13][14][15][16][17]), we use one made to resemble QED -that is, a theory of charged fermions. It has the advantage of being simple.…”

From Hadronic Cross Section to the measurement of the Vacuum Polarization at KLOE: a fascinating endeavour

“…1. to search for a light vector boson [38]; The SM predictions refer to: JN09 [31], DHMZ11 [32], HLMNT11 [33], JS11 [34], BDDJ15 [35], DHMZ16 [36], FJ16 [37]. KLOE08 [21], KLOE10 [22], and KLOE12 [30] refer to the compilations where KLOE data are included.…”

“…Measurement of the running of the fine structure constant below 1 GeVWith about 2 fb −1 of luminosity collected in 2004-2005, the KLOE-2 Collaboration -the successor of KLOE -embarked in a full statistics analysis of the µµγ cross section with a twofold motivation:1. to search for a light vector boson[38];…”

A New Torsion Balance for the Search of Long-range Interactions Coupling to Baryon and Lepton Numbers

“…The possible existence of a 'dark/hidden sector' of particles which are neutral to the forces of the SM has been a leading motivation for Beyond Standard Model (BSM) physics searches and EP experiments are capable of probing the parameter spaces of these models [6]. Despite the sensitive bounds on η shown above plenty of untouched parameter space exists for future EEP violation searches to explore in the context of BSM physics and constrain properties of new particles of interest such as dark photons and Weakly Interacting Massive Particles (WIMPs) [14,15].…”