String-derived MSSM vacua with residual R symmetries

Abstract

Recently it was shown that there is a unique R 4 symmetry for the MSSM which allows the Yukawa couplings and dimension five neutrino mass operator, forbids the µ term and commutes with SO(10). This R 4 symmetry contains matter parity as a subgroup and forbids dimension four and five proton decay operators. We show how to construct string vacua with discrete R symmetries in general and this symmetry in particular, and present an explicit example which exhibits the exact MSSM spectrum, the R 4 symmetry as well as other desired features such as gauge-top unification. We introduce the Hilbert basis method for determining all D-flat configurations and efficient algorithms for identifying field configurations with a desired residual symmetry. These methods are used in an explicit example, in which we describe in detail how to construct a supersymmetric vacuum configuration with the phenomenologically attractive R 4 symmetry. At the perturbative level, this is a supersymmetric Minkowski vacuum in which almost all singlet fields (moduli) are fixed.

Discrete gauge symmetry and Aharonov-Bohm radiation in string theory

“…On the other hand, AB particles associated with Z I 3 are objects electrically couple toà I µ , thus they are the fundamental strings ending on a, b, c branes in the context of string theory. 10 We choose n 2 a = 0, n 1 c = n 2 d m 3 d , m 3 a = m 3 d = 1, n 1 c = n 2 d = 3 and Ng = 3 in the models studied in [28].…”

“…Various applications have been discussed (see [1][2][3][4][5][6][7][8][9][10][11][12] and references therein) in the contexts of stabilizing baryons, suppressing flavor changing neutral currents and fixing the quark and lepton mixing angles. Recent arguments by Banks and Seiberg shed new light on this subject from a different viewpoint [13].…”

A zip-code for quarks, leptons and Higgs bosons

“…As discussed in ref [25] we can determine the gauge groups in the hidden sector and this leads to an acceptable gravitino mass in the (multi) TeV-range (provided the dilaton is fixed at a realistic grand unified gauge coupling). If we assume a stabilization of moduli in the spirit discussed in [46,47], we would then remain with a run-away dilaton and a positive vacuum energy. It can be shown that the adjustment of the vacuum energy with a matter superpotential (downlifting the vacuum energy) one can fix the dilaton as well.…”

Proton hexality in local grand unification

“…Moreover, it has recently been argued that discrete symmetries appear abundantly in string model constructions [15][16][17], with important applications for particle physics model building [18][19][20][21][22]. We are thus in a situation that P 6 could originate from a string model as consistent UV completion and that such a symmetry is compatible with local grand unification.…”