RR photons

Abstract

Type II string compactifications to 4d generically contain massless RamondRamond U(1) gauge symmetries. However there is no massless matter charged under these U(1)'s, which makes a priori difficult to measure any physical consequences of their existence. There is however a window of opportunity if these RR U(1)'s mix with the hypercharge U(1) Y (hence with the photon). In this paper we study in detail different avenues by which U(1) RR bosons may mix with D-brane U(1)'s. We concentrate on Type IIA orientifolds and their M-theory lift, and provide geometric criteria for the existence of such mixing, which may occur either via standard kinetic mixing or via the mass terms induced by Stückelberg couplings. The latter case is particularly interesting, and appears whenever D-branes wrap torsional p-cycles in the compactification manifold. We also show that in the presence of torsional cycles discrete gauge symmetries and Aharanov-Bohm strings and particles appear in the 4d effective action, and that type IIA Stückelberg couplings can be understood in terms of torsional (co)homology in M-theory. We provide examples of Type IIA Calabi-Yau orientifolds in which the required torsional cycles exist and kinetic mixing induced by mass mixing is present. We discuss some phenomenological consequences of our findings. In particular, we find that mass mixing may induce corrections relevant for hypercharge gauge coupling unification in F-theory SU(5) GUT's.

Massive Abelian gauge symmetries and fluxes in F-theory

“…It is worth noting that our proposal differs slightly in its implementation of the differential structure from similar setups such as presented in [70,74,75]. Once the first relation in (3.13) is introduced the natural complement relation involves a set of non-closed 5-forms rather than the 3-forms we have introduced.…”

Discrete gauge symmetry and Aharonov-Bohm radiation in string theory

“…In string theories, discrete gauge symmetries have been widely studied from various points of view [22][23][24][25][26][27][28][29][30][31][32][33][34][35]. For example, in [30], BF coupling is derived by dimensionally reducing the Chern-Simons coupling in a flux compactification, and, in [27], by dimensional reduction of the kinetic term of an RR-field in a compactification with discrete torsions.…”

“…For example, in [30], BF coupling is derived by dimensionally reducing the Chern-Simons coupling in a flux compactification, and, in [27], by dimensional reduction of the kinetic term of an RR-field in a compactification with discrete torsions. It is fascinating that seemingly different such studies can be understood in a uniform manner by BF couplings.…”

“…which is one of recent progresses on discrete gauge symmetries in string theories [27][28][29][30], the essential arguments can be applied to various related models.…”

Massive vector fields on the Schwarzschild spacetime: Quasinormal modes and bound states

“…Massive hidden U (1) vector fields are also a generic feature of Beyond-Standard-Model scenarios and, in particular, string theory compactifications, arising in the latter case from a variety of sources, such as broken nonAbelian orbifolds in heterotic compactifications, and Dbrane configurations and bulk Ramond-Ramond fields in type II string theories [52][53][54]. The nature of U (1) vector masses is, however, inherently different from the axion case, where the associated shift symmetry (reminiscent of an underlying U (1) symmetry) is only broken nonperturbatively.…”