Revisiting light stringy states in view of the 750 GeV diphoton excess

TL;DR

This paper explores light massive string states at brane intersections, their spectrum, interactions, and proposes a novel interpretation of the 750 GeV diphoton excess as a stringy Higgs replica.

Contribution

It identifies and characterizes light massive string states, constructs their vertex operators, and offers a new string-based explanation for the 750 GeV diphoton excess.

Findings

Light massive string states can be parametrically lighter than Regge excitations.

Explicit vertex operators for these states are constructed.

A potential string-theoretic explanation for the 750 GeV diphoton excess is proposed.

Abstract

We investigate light massive string states that appear at brane intersections. They replicate the massless spectrum in a richer fashion and may be parametrically lighter than standard Regge excitations. We identify the first few physical states and determine their BRST invariant vertex operators. In the supersymmetric case we reconstruct the super-multiplet structure. We then compute some simple interactions, such as the decay rate of a massive scalar or vector into two massless fermions. Finally we suggest an alternative interpretation of the 750 GeV diphoton excess at LHC in terms of a light massive string state, a replica of the Standard Model Higgs.