The 750 GeV LHC diphoton excess from a baryon number conserving string model

Abstract

We propose an explanation of the LHC data excess resonance of 750 GeV in the diphoton distribution using D-brane models, with gauged baryon number, which accommodate the Standard Model together with vector like exotics. We identify the 750 GeV scalar as either the sneutrino (${\tilde \nu}_R$) or as an axion. Using a bottom-up approch, ${\tilde \nu}_R$ is produced via gluon fusion when scalar (supersymmetric) partners of vector like quarks and leptons are generated by demanding that the corresponding intersections respect N=1 supersymmetry. When we generate the value of ${\tilde \nu}_R$ at 750 GeV, by varying the complex structure of the torus, the string scale is limited to be in the range $ 10^{14} < M_s < 10^{19}$ GeV. Also, generating the Higgs scalars by imposing N=1 supersymmetry on intersections fixes naturally, to zero, the coupling of the axion to SU(2) gauge bosons $\propto F_b \wedge F_b$ and in photon-photon fusion also decouples its coupling from $G^2$ of color SU(3) by simultaneously generating the superpartners of $q_L$, $U_R$, $l_L$, $\nu_R$ quarks and leptons.