The flipped SU(5)×U(1) string model revamped

Antoniadis, Ignatios; Ellis, Jonathan Richard; Hagelin, John S.; Nanopoulos, Dimitri V.

doi:10.1016/0370-2693(89)90115-9

Cited by 459 publications

(723 citation statements)

References 57 publications

Supporting

Mentioning

711

Contrasting

Unclassified

Order By: Relevance

“…(z k |e 1,2,3,4,5,6 2, 3, 4, 5, 6} for k = 1 or/and k = 2. In this case the gauge group enhancement includes several possibilities, depending on the (b 1 |z k ) we can obtain: ( Depending on the separate enhancements of SO(8) k for k = 1, 2 we can obtain for example:…”

Section: The Four Dimensional Gauge Groupmentioning

confidence: 99%

Spinor-vector duality in heterotic string vacua

2008

View full text Add to dashboard Cite

Classification of the N = 1 space-time supersymmetric fermionic Z 2 × Z 2 heterotic-string vacua with symmetric internal shifts, revealed a novel spinorvector duality symmetry over the entire space of vacua, where the S t ↔ V duality interchanges the spinor plus anti-spinor representations with vector representations. In this paper we demonstrate that the spinor-vector duality exists also in fermionic Z 2 heterotic string models, which preserve N = 2 space-time supersymmetry. In this case the interchange is between spinorial and vectorial representations of the unbroken SO(12) GUT symmetry. We provide a general algebraic proof for the existence of the S t ↔ V duality map. We present a novel basis to generate the free fermionic models in which the ten dimensional gauge degrees of freedom are grouped into four groups of four, each generating an SO(8) modular block. In the new basis the GUT symmetries are produced by generators arising from the trivial and non-trivial sectors, and due to the triality property of the SO(8) representations. Thus, while in the new basis the appearance of GUT symmetries is more cumbersome, it may be more instrumental in revealing the duality symmetries that underly the string vacua.

show abstract

Section: The Four Dimensional Gauge Groupmentioning

confidence: 99%

Spinor-vector duality in heterotic string vacua

2008

View full text Add to dashboard Cite

show abstract

“…They also generate all other τ B -invariant curves, so the most general τ B -invariant class η ∈ H 2 (dP 3 , Z) is a linear combination 5) for some arbitrary integer coefficients m j to be determined imposing the requirements summarized in section 2.7. The first Chern class c 1 (dP 3 ) reads, in terms of the M j ,…”

Section: Vacua Over the Del Pezzo Surface Dpmentioning

confidence: 99%

“…It should be emphasized, however, that the heterotic string in itself does not guarantee the preservation of the SO (10) embedding and indeed many quasirealistic models have been constructed that do not maintain the SO (10) embedding [4]. A class of realistic string models that do preserve the SO (10) embedding are the free fermionic heterotic string models [5]. In these three generation models the SO (10) symmetry is broken to one of its subgroups by utilizing Wilson line symmetry breaking.…”

Section: Introductionmentioning

confidence: 99%

Nonperturbative flipped SU(5) vacua in heterotic M-theory

2002

View full text Add to dashboard Cite

The evidence for neutrino masses in atmospheric and solar neutrino experiments provides further support for the embedding of the Standard Model fermions in the chiral 16 SO(10) representation. Such an embedding is afforded by the realistic free fermionic heterotic-string models. In this paper we advance the study of these string models toward a non-perturbative analysis by generalizing the work of Donagi, Pantev, Ovrut and Waldram from the case of G = SU (2n + 1) to G = SU (2n) stable holomorphic vector bundles on elliptically fibered Calabi-Yau manifolds with fundamental group Z 2 . We demonstrate existence of G = SU (4) solutions with three generations and SO(10) observable gauge group over Hirzebruch base surface, whereas we show that certain classes of del Pezzo base surface do not admit such solutions. The SO(10) symmetry is broken to SU (5) × U (1) by Wilson line. The overlap with the realistic free fermionic heterotic-string models is discussed. * faraggi@thphys.ox.ac.uk

show abstract

“…[69], and of analogous results obtained for the free fermionic formulation of string theory [70] (for applications based on this formulation, see e.g., Ref. [71], [30], [31] and [72]), that grand unification occurs, through symmetries like E 6 , SO(10) or SU(5), only in some higher dimension (d > 4), and that the breaking of the unification gauge symmetry to some lower symmetry containing the standard model gauge group as well as doublet-triplet splitting occurs in the process of compactification. More specifically the latter two phenomena take place through either (a) Wilson lines [69], or (b) orbifolds [73] (for an incomplete list of recent attempts based on orbifold compactification, see e.g., Refs.…”

Section: Conventional Versus Other Approachesmentioning

confidence: 53%

“…More specifically the latter two phenomena take place through either (a) Wilson lines [69], or (b) orbifolds [73] (for an incomplete list of recent attempts based on orbifold compactification, see e.g., Refs. [74,75,76,77,79,80,81]), or (c) essentially equivalently by a set of boundary conditions together with the associated GSO projections for the free fermionic formulation (see e.g., [30,31,71,72]), or (d) discrete symmetries operating in higher dimensions [82].…”

Section: Conventional Versus Other Approachesmentioning

confidence: 99%

Probing grand unification with fermion masses, neutrino oscillations and proton decay

Pati

2003

Pramana - J Phys

View full text Add to dashboard Cite

It is noted that one is now in possession of a set of facts, which may be viewed as the matching pieces of a puzzle; in that all of them can be resolved by just one idea-that is grand unification. These include (i) the observed family-structure, (ii) quantization of electric charge, (iii) the meeting of the three gauge couplings, (iv) neutrino oscillations [in particular the value ∆m 2 (ν µ − ν τ ), suggested by SuperK], (v) the intricate pattern of the masses and mixings of the fermions, including the smallness of V cb and the largeness of θ osc νµντ , and (vi) the need for B-L as a generator to implement baryogenesis (via leptogenesis). All these pieces fit beautifully together within a single puzzle board framed by supersymmetric unification, based on either SO(10) or a string-unified G(224)-symmetry. The two notable pieces of the puzzle still missing, however, are proton decay and supersymmetry.A concrete proposal is presented within a predictive SO(10)/G(224)-framework that successfully describes the masses and mixings of all fermions, including the neutrinos-with eight predictions, all in agreement with observation. Within this framework, a systematic study of proton decay is carried out, which (a) pays special attention to its dependence on the fermion masses, and (b) limits the threshold corrections so as to preserve natural coupling unification. The study updates prior work by Babu, Pati and Wilczek, in the context of both MSSM and its (interesting) variant, the so-called ESSM, by allowing for improved values of the matrix elements and of the short-and long-distance renormalization effects. It shows that a conservative upper limit on the proton lifetime is about (1/3 -2)×10 34 years, with νK + being the dominant decay mode, and quite possibly µ + K 0 and e + π 0 being prominent. This in turn strongly suggests that an improvement in the current sensitivity by a factor of five to ten (compared to SuperK) ought to reveal proton decay. Otherwise some promising and remarkably successful ideas on unification would suffer a major setback. For comparison, some alternatives to the conventional approach to unification pursued here are mentioned at the end.

show abstract

The flipped SU(5)×U(1) string model revamped

Cited by 459 publications

References 57 publications

Spinor-vector duality in heterotic string vacua

Spinor-vector duality in heterotic string vacua

Nonperturbative flipped SU(5) vacua in heterotic M-theory

Probing grand unification with fermion masses, neutrino oscillations and proton decay

Contact Info

Product

Resources

About