Towards predictive flavour models in SUSY SU(5) GUTs with doublet-triplet splitting

We review the problem of neutrino masses and mixings in the context of grand unified theories. After a brief summary of the present experimental status of neutrino physics, we describe how the see-saw mechanism can automatically account for the large atmospheric mixing angle. We provide two specific examples where this possibility is realized by means of a flavor symmetry. We then review in some detail the various severe problems which plague minimal GUT models (like the doublet–triplet splitting and proton-decay) and which force us to investigate the possibility of constructing more elaborate but realistic models. We then show an example of a quasirealistic SUSY SU(5) model which, by exploiting the crucial presence of an Abelian flavor symmetry, does not require any fine-tuning and predicts a satisfactory phenomenology with respect to coupling unification, fermion masses and mixings and bounds from proton decay.

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REDUCED MULTIREFERENCE COUPLED-CLUSTER METHOD AND ITS APPLICATION TO THE PYRIDYNE DIRADICALS

Journal of Theoretical and Computational Chemistry ◽

10.1142/s0219633608004131 ◽

2008 ◽

Vol 07 (04) ◽

pp. 805-820 ◽

Cited By ~ 17

Author(s):

XIANGZHU LI ◽

JOSEF PALDUS

Keyword(s):

Molecular Geometry ◽

External Source ◽

Cluster Method ◽

Coupled Cluster ◽

Triplet States ◽

Correlation Effects ◽

Spin Multiplicity ◽

Triplet Splitting ◽

Singlet And Triplet States

The reduced multireference (RMR) coupled-cluster (CC) method with singles and doubles (RMR CCSD) that employs a modest-size MR CISD wave function as an external source for the most important (primary) triples and quadruples in order to account for the nondynamic correlation effects in the presence of quasidegeneracy, and which is further perturbatively corrected for the remaining (secondary) triples, RMR CCSD(T), is employed to compute the molecular geometry and the energy of the lowest-lying singlet and triplet states, as well as the corresponding singlet–triplet splitting, for all possible isomers of the m, n-pyridyne diradicals. A comparison is made with earlier results that were obtained by other authors, and the role of the multireference effects for both the geometry and the spin multiplicity of the lowest state, as described by the RMR-type methods, is demonstrated on the example of 2,6- and 3,5-pyridynes.

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Ab initio molecular orbital studies on a singlet-triplet splitting of C3H6 and C4H8 molecules

Journal of Molecular Structure THEOCHEM ◽

10.1016/0166-1280(91)85139-x ◽

1991 ◽

Vol 251 ◽

pp. 141-151 ◽

Cited By ~ 13

Author(s):

A.A. Ovchinnikov ◽

I.L. Shamovsky ◽

K.V. Bozhenko

Keyword(s):

Ab Initio ◽

Molecular Orbital ◽

Triplet Splitting

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High performance full color OLEDs based on a class of molecules with dual carrier transport channels and small singlet–triplet splitting

Chemical Communications ◽

10.1039/c5cc03492b ◽

2015 ◽

Vol 51 (53) ◽

pp. 10632-10635 ◽

Cited By ~ 72

Author(s):

Chenglong Li ◽

Shipan Wang ◽

Weiping Chen ◽

Jinbei Wei ◽

Guochun Yang ◽

...

Keyword(s):

High Performance ◽

Carrier Transport ◽

Blue Emission ◽

Deep Blue ◽

Full Color ◽

Triplet Splitting ◽

Transport Channels

The strong deep blue emission, good ambipolar carrier transport and small singlet–triplet splitting characteristics allow PPI-PPITPA and PPI-PPIPCz as emitting materials and hosts to fabricate high performance full color OLEDs.

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