Ignatios Antoniadis

750 GeV diphotons from closed string states

We show that low-mass-scale string compactifications, with a generic D-brane configuration that realizes the standard model by open strings, can explain the relatively broad peak in the diphoton invariant mass spectrum at 750 GeV recently reported by the ATLAS and CMS Collaborations. Under reasonable assumptions, we demonstrate that the excess could originate from a closed string (possibly axionic) excitation φ that has a coupling with gauge kinetic terms. We estimate the φ production rate from photon–photon fusion in elastic pp scattering, using the effective photon and narrow width approximations. For string scales above todays lower limit Ms ≈ 7 TeV, we can accommodate the diphoton rate observed at Run II while maintaining consistency with Run I data.

The coupling of non-linear supersymmetry to supergravity

We study the coupling of non-linear supersymmetry to supergravity. The goldstino nilpotent superfield of global supersymmetry coupled to supergravity is described by a geometric action of the chiral curvature superfield

Update on 750 GeV diphotons from closed string states

mathscr {R}

Inflation from supergravity with gauged R-symmetry in de Sitter vacuum

R subject to the constraint

Heisenberg symmetry and hypermultiplet manifolds

(mathscr {R}-lambda )^2=0

Probing the moduli dependence of refined topological amplitudes

(R-λ)2=0 with an appropriate constant