Magnetic monopoles and free fractionally charged states at accelerators and in cosmic rays

Abstract

Unified theories of strong, weak and electromagnetic interactions which have electric charge quantization predict the existence of topologically stable magnetic monopoles. Intermediate scale monopoles are comparable with detection energies of cosmic ray monopoles at IceCube and other cosmic ray experiments. Magnetic monopoles in some models can be significantly lighter and carry two, three or possibly even higher quanta of the Dirac magnetic charge. They could be light enough for their effects to be detected at the LHC either directly or indirectly. An example based on a D-brane inspired SU(3) C × SU(3) L × SU(3) R (trinification) model with the monopole carrying three quanta of Dirac magnetic charge is presented. These theories also predict the existence of color singlet states with fractional electric charge which may be accessible at the LHC.

Weak-U(1) × strong-U(1) effective gauge field theories and electron-monopole scattering

“…Notice that in our approach, in contrast to that of Zwanziger [2], which was adopted in [18], the photon (A µ ) and the dual photon (B µ ) are independent fields, which explains the presence of the last two graphs on the right-hand side of the figure (connected with a "+" sign). When however consider the monopole, one should impose on the classical on-shell gauge fields the constraint (10), which brings back the Dirac-string effects. For slowly moving monopoles, Z 1 and this ensures perturbativity of all couplings, hence the depicted graphs denote the leading corrections in both A µ and B µ sectors.…”

“…The analysis has been performed in [18] and in previous relevant literature referenced there, and we shall not repeat it here. We only point out a trivial modification in our case as compared to those works, namely the addition of the soft-B µ (dual-photon)-emission graph, since, in contrast to the standard Zwanziger approach [2], here the fields A µ and B µ are treated as independent gauge fields, not related through (6), except when one considers classical solutions (10). Such solutions are the on-shell solutions represented by the external gauge field wavy lines in the graphs, and will combine the A and B photon emission into one; this is indicated with the pertinent "+" sign in fig.…”

“…In superstring theories, with appropriate grand unifying gauge groups, broken by stringy methods (Wilson lines), structures with magnetic charges have been first considered in [9]. Moreover, in D-brane-inspired GUT models [10], the unification scale (and hence the mass of the appropriate magnetic monopoles/dyons) can be lowered significantly, down to 10 4 − 10 6 GeV, relevant for future collider or cosmic-ray searches.…”

Searches for magnetic monopoles with IceCube

“…The proposed inflationary phase of the early universe leads to a dilution of the monopole density. Intermediate (or smaller) mass monopoles are predicted within intermediate steps of symmetry breaking during or after inflation with masses in the order of 10 7 GeV to 10 13 GeV [4,5]. Monopoles at relativistic speeds are expected to have intermediate masses since only in this mass range they can be sufficiently accelerated in cosmic magnetic fields [4].…”

Ongoing magnetic monopole searches with IceCube

“…Only with the introduction of a magnetic counterpart to the electron, the magnetic monopole, do the Maxwell equations become symmetric. The question of the existence of this hypothetical particle has become more important as all Grand Unifying Theories (GUTs) as well supersymmetry (SUSY) theories predict them [1]. Multiple searches for magnetic monopoles have been conducted at multiple experiments over the past serveral years.…”