scholarly journals THE FERMION GENERATION PROBLEM IN THE GUST’S OF THE FREE WORLD SHEET FERMION FORMULATION

1996 ◽  
Vol 11 (06) ◽  
pp. 1117-1168 ◽  
Author(s):  
A.A. MASLIKOV ◽  
I.A. NAUMOV ◽  
G.G. VOLKOV
Keyword(s):  
Gauge Symmetry ◽  
Mass Spectra ◽  
World Sheet ◽  
Family Symmetry ◽  
Low Mass ◽  
Level 1 ◽  
Low Dimensional ◽  
String Models ◽  
Diagonal Subgroup ◽  
Generation Problem

In the framework of the four-dimensional heterotic superstring with free fermions, we investigate the rank 8 grand unified string theories (GUST’s) which contain the SU (3)H gauge family symmetry, and develop some methods for building corresponding string models. We explicitly construct GUST’s with gauge symmetry G= SU (5)× U (1) × [ SU (3)× U (1)]H and G= SO (10)×[ SU (3)× U (1)]H ⊂ SO (16) or E(6)× SU (3)H ⊂ E(8), and consider the full massless spectrum for our string models. As the GUST’s originating from level 1 Kac–Moody algebra (KMA) contain only low-dimensional representations, we consider for the observable gauge symmetry the diagonal subgroup G sym of the rank 16 group G×G ⊂ SO (16)× SO (16) or ⊂ E(8)×E(8). We discuss the possible fermion matter and Higgs sectors in these theories. There has to exist “superweak” light chiral matter [Formula: see text] in the GUST’s under consideration. The understanding of quark and lepton mass spectra and family mixing leaves a possibility for the existence of an unusually low mass breaking scale of the SU (3)H family gauge symmetry (some TeV).

STRING-MOTIVATED GRAND UNIFIED THEORIES WITH HORIZONTAL GAUGE SYMMETRY

1994 ◽  
Vol 09 (30) ◽  
pp. 5369-5385 ◽  
Author(s):  
A.A. MASLIKOV ◽  
S.M. SERGEEV ◽  
G.G. VOLKOV
Keyword(s):  
Gauge Symmetry ◽  
Fermion Mass ◽  
Family Symmetry ◽  
Grand Unified Theories ◽  
Higher Dimensional ◽  
Unified Theories ◽  
Low Dimensional ◽  
Diagonal Subgroup ◽  
Higgs Fields ◽  
Level 2

In the framework of four-dimensional heterotic superstring with free fermions, we investigate the rank 8 grand unified string theories (GUST’s) which contain the SU(3) H gauge family symmetry. GUST’s of this type accommodate naturally the three fermion families presently observed and, moreover, can describe the fermion mass spectrum without high-dimensional representations of conventional unification groups. We explicitly construct GUST’s with gauge symmetry G= SU(5) × U(1) ×[ SU(3) × U(1) ]H ⊂ SO (16) in free complex fermion formulation. As the GUST’s originating from Kac-Moody algebras (KMA’s) contain only low-dimensional representations, it is usually difficult to break the gauge symmetry. We solve this problem by taking for the observable gauge symmetry the diagonal subgroup G sym of the rank 16 group G×G ⊂ SO(16) × SO(16) ⊂ E(8)×E(8). Such a construction effectively corresponds to a level 2 KMA, and therefore some higher-dimensional representations of the diagonal subgroup appear. This (due to G×G tensor Higgs fields) allows one to break GUST symmetry down to SU (3c)× U(1) em . In this approach the observed electromagnetic charge Q em can be viewed as a sum of two Q I and Q II charges of each G group. In this case, below the scale where G×G breaks down to G sym the spectrum does not contain particles with exotic fractional charges.

FERMIONIC STRING MODELS AND ZN ORBIFOLDS

1989 ◽  
Vol 04 (24) ◽  
pp. 2339-2347 ◽  
Author(s):  
DAVID C. DUNBAR
Keyword(s):  
Boundary Conditions ◽  
World Sheet ◽  
Fermionic String ◽  
String Models ◽  
Special Case

It is shown that ZN orbifold models may, in special case be realised by a set world sheet fermions which have boundary conditions which are non-diagonal.

STUDY OF IN-MEDIUM MESON MODIFICATION IN 12 GeV p + A REACTIONS

2007 ◽  
Vol 22 (02n03) ◽  
pp. 397-405 ◽  
Author(s):  
◽  
S. Yokkaichi ◽  
H. En'yo ◽  
M. Naruki ◽  
R. Muto ◽  
...  
Keyword(s):  
Nuclear Matter ◽  
Invariant Mass ◽  
Mass Spectra ◽  
Proton Synchrotron ◽  
Vector Mesons ◽  
Significant Excess ◽  
Cold Nuclear Matter ◽  
Spectral Modification ◽  
Low Mass ◽  
Target Data

Invariant mass spectra of low-mass vector mesons in the e+e- channel are measured in 12 GeV p + C and p + Cu reactions [Formula: see text] at the KEK Proton Synchrotron. Significant excess is observed at the low-mass side of ω meson peak over the known hadronic sources both in the C and Cu target data. Also below the ϕ meson peak, an excess is found in the Cu target data for slowly moving mesons whose βγ is less than 1.25. They can be interpreted as signatures of the spectral modification of vector mesons in cold nuclear matter.

Di-lepton production in heavy-ion collisions and the QCD phase diagram

Open Physics ◽  
2012 ◽  
Vol 10 (6) ◽  
Author(s):  
Yifei Zhang ◽  
Haojie Xu ◽  
Wangmei Zha ◽  
Qun Wang
Keyword(s):  
Phase Diagram ◽  
Mass Spectra ◽  
Heavy Ion ◽  
Mass Region ◽  
Lepton Production ◽  
Qcd Phase Diagram ◽  
Ion Collisions ◽  
200 Gev ◽  
Star Experiment ◽  
Low Mass

AbstractWe reproduce di-electron spectra in the region of 0 < m e+e < 4 GeV in both minimum bias and central Au+Au collisions at $\sqrt {s_{NN} } $ = 200 GeV measured by the STAR experiment. A cocktail simulation, incorporating STAR acceptance and detector responses, is able to describe the “enhancement” of the low mass region by including an in-medium modification of vector mesons and a thermal di-lepton calculation. We also predict the di-lepton mass spectra in RHIC lower energies via an extrapolation method. The evolution of Di-lepton mass spectra, effective temperature, and possible medium modifications versus colliding energies are studied to explore the QCD phase diagram.

scholarly journals ASYMMETRY OF IN-MEDIUM ρ-MESONS AS A SIGNATURE OF CHERENKOV EFFECTS

2009 ◽  
Vol 24 (06) ◽  
pp. 1221-1228 ◽  
Author(s):  
I. M. DREMIN ◽  
V. A. NECHITAILO
Keyword(s):  
Mass Spectra ◽  
Meson Mass ◽  
Low Mass ◽  
The Asymmetry

Cherenkov gluons may be responsible for the asymmetry of dilepton mass spectra near ρ-meson observed in experiment. They can be in charge only for dileptons in the low-mass wing of the resonance. Therefore the dilepton mass spectra are flattened there and their peak is slightly shifted to lower masses compared with the in-vacuum ρ-meson mass. This feature must be common for all resonances.

scholarly journals A learned embedding for efficient joint analysis of millions of mass spectra

2018 ◽  
Author(s):  
Damon H. May ◽  
Jeffrey Bilmes ◽  
William S. Noble
Keyword(s):  
Mass Spectra ◽  
Large Scale ◽  
Dimensional Space ◽  
Software Implementation ◽  
Mass Spectrometry Data ◽  
Joint Analysis ◽  
Clustering Methods ◽  
Peptide Mass ◽  
Public Repositories ◽  
Low Dimensional

AbstractDespite an explosion of data in public repositories, peptide mass spectra are usually analyzed by each laboratory in isolation, treating each experiment as if it has no relationship to any others. This approach fails to exploit the wealth of existing, previously analyzed mass spectrometry data. Others have jointly analyzed many mass spectra, often using clustering. However, mass spectra are not necessarily best summarized as clusters, and although new spectra can be added to existing clusters, clustering methods previously applied to mass spectra do not allow new clusters to be defined without completely re-clustering. As an alternative, we propose to train a deep neural network, called “GLEAMS,” to learn an embedding of spectra into a low-dimensional space in which spectra generated by the same peptide are close to one another. We demonstrate empirically the utility of this learned embedding by propagating annotations from labeled to unlabeled spectra. We further use GLEAMS to detect groups of unidentified, proximal spectra representing the same peptide, and we show how to use these spectral communities to reveal misidentified spectra and to characterize frequently observed but consistently unidentified molecular species. We provide a software implementation of our approach, along with a tool to quickly embed additional spectra using a pre-trained model, to facilitate large-scale analyses.

CONSTRUCTION OF FOUR DIMENSIONAL FERMIONIC STRING MODELS WITH A GENERALIZED SUPERCURRENT

1988 ◽  
Vol 03 (01) ◽  
pp. 279-284 ◽  
Author(s):  
HIKARU KAWAI ◽  
DAVID C. LEWELLEN ◽  
S.-H. HENRY TYE
Keyword(s):  
Spin Structure ◽  
Model Building ◽  
World Sheet ◽  
The World ◽  
Fermionic String ◽  
String Models

The spin structure construction of four-dimensional fermionic string models of the heterotic type is extended by considering a generalized form of the world-sheet super-current. The rules for model building are given and illustrated with two sets of examples: the original spin structure construction and the Z3 asymmetric orbifold.

scholarly journals Supersymmetric U(1)Y′⊗ U(1)B−L extension of the Standard Model

2017 ◽  
Vol 32 (16) ◽  
pp. 1750093 ◽  
Author(s):  
J. C. Montero ◽  
V. Pleitez ◽  
B. L. Sánchez-Vega ◽  
M. C. Rodriguez
Keyword(s):  
Gauge Symmetry ◽  
Mass Spectra ◽  
Tree Level ◽  
Neutrino Masses ◽  
Type I ◽  
Seesaw Mechanism ◽  
Active Neutrino ◽  
Supersymmetric Version ◽  
Fermion Masses ◽  
The Standard Model

We build a supersymmetric version with [Formula: see text] gauge symmetry, where [Formula: see text] is a new charge and [Formula: see text] and [Formula: see text] are the usual baryonic and leptonic numbers. The model has three right-handed neutrinos with identical [Formula: see text] charges, and can accommodate all fermion masses at the tree level. In particular, the type I seesaw mechanism is implemented for the generation of the active neutrino masses. We obtain the mass spectra of all sectors and for the scalar one we also give the flat directions allowed by the model.

scholarly journals The Unification in the String Theories with the G × G Gauge Groups

1997 ◽  
Vol 12 (26) ◽  
pp. 1909-1927
Author(s):  
A. Maslikov ◽  
I. Naumov ◽  
G. Volkov
Keyword(s):  
Gauge Symmetry ◽  
Gauge Group ◽  
Family Symmetry ◽  
Gauge Groups ◽  
Free Fermions ◽  
String Theories

In the framework of the four-dimensional heterotic superstring with free fermions we discuss the rank eight and/or 16 Grand Unified String Theories (GUSTs) which contain the SU (3)H-gauge family symmetry. We explicitly investigate the paths of the unification in the GUST with gauge symmetry G × G = [ SU (5)× U (1)×( SU (3)× U (1))H]⊗2. We show that the GUSTs with the G × G gauge group allow one to make the scale of unification to be consistent with the string scale M SU ~ g str ×5×1017 GeV.

scholarly journals REDUNDANCIES IN EXPLICITLY CONSTRUCTED TEN-DIMENSIONAL HETEROTIC STRING MODELS

2011 ◽  
Vol 26 (25) ◽  
pp. 4451-4473 ◽  
Author(s):  
TIMOTHY RENNER ◽  
JARED GREENWALD ◽  
DOUGLAS MOORE ◽  
GERALD CLEAVER
Keyword(s):  
Construction Method ◽  
Space Time ◽  
Heterotic String ◽  
Large Space ◽  
Weakly Coupled ◽  
Level 1 ◽  
String Models ◽  
Basis Vectors

Using Baylor University's C ++ software for construction of weakly coupled free fermionic heterotic string models, called the FF Framework, we explicitly construct the level-1 Kač–Moody ten-dimensional heterotic string models with the aim of understanding the redundancies endemic to this construction method. We show that for models in any even number of large space–time dimensions with a massless left-mover and an odd ordered right-mover, the maximal number of space–time supersymmetries are present. We show that in order to produce all of the models for a given order, different basis vectors must be built; one cannot vary only the GSO coefficients. We also show that all combinations of two order-2 basis vectors do not produce the same models as all possible single order-4 basis vectors, implying the product of the orders used in a search does not necessarily determine the models built. We also show that to build all of the D = 10 level-1 models the inputs must be: sets of single order-6 basis vectors, pairs of basis vectors with orders 3 and 2, or sets of three order-2 basis vectors.

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