An SU(4) × SU(2)L × SU(2)R string model with direct unification at the string scale

Murayama, Akihiro; Toon, Andrew

doi:10.1016/0370-2693(93)90132-2

Cited by 18 publications

(9 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In fact, there are no gauge bosons mediating proton decay and the SU( 4) breaking scale can be low enough provided this is consistent with the low energy values of gauge couplings. This is indeed the case revealed in several recent renormalization group analyses [20,21] of models based on the PS-gauge group. Note however that a realistic model should at least have SU( 5) or a higher rank symmetry as a confining group.…”

supporting

confidence: 70%

Supercompositeness from superstrings

Dimopoulos

Leontaris

Tracas

1997

Zeitschrift f�r Physik C Particles and Fields

View full text Add to dashboard Cite

String Unified Models based on the k = 1 level of the Kac-Moody Algebra, predict the existence of "exotic" new states which carry fractional electric charges. We analyse the possibility of considering these "exotics" as preonic matter which can be used to form the families and the gauge group breaking higgs scalars. It is proposed that such a formation may occur provided that these states transform non-trivially under a non-Abelian gauge group with a relatively large rank in order to confine them at a sufficiently large scale. Such a situation is natural in string derived unified models, since the role of the confining group can be played by (part of) the Hidden symmetry. As an example, we present a string derived toy model based on the SU(4) × SU(2) L × SU(2) R Pati-Salam gauge group.IOA-01/96 NTUA 54-96(1) pdimop@zeus.central.ntua.gr (2) leonta@cc.uoi.gr (3) ntrac@zeus.central.ntua.gr 1 Compositeness may also be combined with Technicolor and Extended Technicolor Theories[16] to produce interactions which may create dynamically the fermion masses.

show abstract

supporting

confidence: 70%

Supercompositeness from superstrings

Dimopoulos

Leontaris

Tracas

1997

Zeitschrift f�r Physik C Particles and Fields

View full text Add to dashboard Cite

show abstract

“…As a matter of fact, in a previous paper Ref. [6] the field content without D and one of the bidoublets have been used to raise the unification scale. This field content also satisfies Eq.…”

Section: And DCmentioning

confidence: 99%

“…As a matter of fact, in a previous paper Ref. [6] 2), the constraints on the additional field content is given by :…”

mentioning

confidence: 99%

“…Such realistic string models have been built for cases where the intermediate symmetry is the flipped SU(5)× U(1) [3] or SO(4)× SO(6)∼ SU(2) L ×SU(2) R ×SU(4) C [4][5][6][7], and sometimes the field content of these models have been found to alleviate the discrepancy between the string and gauge unification scales [6][7][8]. In this letter, we shall investigate what field content and additional constraints may be required to have a model with gauge unification at the string scale, that has SU(2) L ×SU(2) R ×SU(4) C breaking to the MSSM at an intermediate scale of ∼ 10 12 GeV, that allows a PQ symmetry also broken ∼ 10 12 GeV with a weakly coupled axion, and where the scale of gauge symmetry breaking and the PQ symmetry breaking are determined by a single parameter in the superpotential.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Towards a viable grand unified model with M ∼ Mstring and M ∼ 1012 GeV

1996

View full text Add to dashboard Cite

We present a model based on the gauge group SU(2) L ×SU(2) R ×SU(4) C with gauge couplings that are found to be unified at a scale M G near the string unification scale. The model breaks to the minimal supersymmetric standard model at a scale M I ∼ 10 12 GeV, which is instrumental in producing a neutrino in a mass range that can serve as hot dark matter and this scale can also solve the strong CP problem via the Peccei-Quinn (PQ) mechanism with an invisible harmless axion. We show how this model can accommodate low and high values of tan β and "exotic" representations that often occur in string derived models. We show that this model has lepton flavor violation which can lead to processes which are one or two orders of magnitude below the current experimental limits.

show abstract

“…Furthermore, a recent non -renormalisable operator analysis [16] of its supersymmetric version, has shown quite remarkable features on the fermion mass matrices [17,18], which provide a strong motivation to study the string derived model in more detail. The renormalisation group analysis of the string version has already been studied in detail in many papers, taking into account GUT, supersymmetric and string threshold corrections [19,20,21]. It was shown that it is possible to obtain the correct range of the low energy parameters while having two different scales, (a string M string ∼ 10 18 GeV and a "GUT" SU(4) gauge breaking around (10 15 −10 16 )GeV ) provided there is an intermediate scale ∼ 10 10 GeV where some "exotic" states acquire their masses.…”

mentioning

confidence: 99%

A string model with SU(4) × O(4) × [Sp(4)]hidden gauge symmetry

Leontaris¹

1996

Physics Letters B

View full text Add to dashboard Cite

In the four dimensional free fermionic formulation of the heterotic string, a semirealistic SU(4) × SU(2) L × SU(2) R model is proposed with three fermion generations in (4, 2, 1) + (4, 1, 2) representations. The gauge symmetry of the model breaks to the standard gauge group using a higgs pair in the (4, 1, 2)+(4, 1, 2) representations. The massless spectrum includes exotic fractionally charged states with non -trivial transformation properties under part (Sp(4)) of the nonabelian 'hidden' symmetry. Finally there is a mirror pair in (4, 2, 1), (4, 2, 1) allowing the possibility for an identical running of g 4,L,R couplings between the string and SU(4) breaking scales. This is of crucial importance for a successful prediction of the weak mixing angle. Potential shortcomings and problems of the construction are analysed and possible solutions are discussed. IOA-335/95 September 95A partially unified group which fulfills the basic requirements [5], is based on 1 more recent attempts[9, 10] to overcome this difficulty have led to SO(10) × SO(10) or SU (5) × SU (5) product groups, where the SO(10) or SU (5) are realized directly at level 1.

show abstract

An SU(4) × SU(2)L × SU(2)R string model with direct unification at the string scale

Cited by 18 publications

References 47 publications

Supercompositeness from superstrings

Supercompositeness from superstrings

Towards a viable grand unified model with M ∼ Mstring and M ∼ 1012 GeV

A string model with SU(4) × O(4) × [Sp(4)]hidden gauge symmetry

Contact Info

Product

Resources

About