SU(8) family unification with boson-fermion balance

CERN Multimedia

CERN. Geneva

2014-01-01

Grand unification has been intensively investigated for over forty years, and many different approaches have been tried. In this talk I propose a model that involves three ingredients that do not appear in the usual constructions: (1) boson--fermion balance without full supersymmetry, (2) canceling the spin 1/2 fermion gauge anomalies against the anomaly from a gauged spin 3/2 gravitino, and (3) using a scalar field representation with non-zero U(1) generator to break the SU(8) gauge symmetry through a ground state which, before dynamical symmetry breaking, has a periodic U(1) generator structure. The model has a number of promising features: (1) natural incorporation of three families, (2) incorporation of the experimentally viable flipped SU(5) model, (3) a symmetry breaking pathway to the standard model using the scalar field required by boson-fermion balance, together with a stage of most attractive channel dynamical symmetry breaking, without postulating additional Higgs fields, (4) vanishing of bare Yuk...

Gauge coupling unification from unified theories in higher dimensions

International Nuclear Information System (INIS)

Hall, Lawrence J.; Nomura, Yasunori

2002-01-01

Higher dimensional grand unified theories, with gauge symmetry breaking by orbifold compactification, possess SU(5) breaking at fixed points, and do not automatically lead to tree-level gauge coupling unification. A new framework is introduced that guarantees precise unification--even the leading loop threshold corrections are predicted, although they are model dependent. Precise agreement with the experimental result, α s exp =0.117±0.002, occurs only for a unique theory, and gives α s KK =0.118±0.004±0.003. Remarkably, this unique theory is also the simplest, with SU(5) gauge interactions and two Higgs hypermultiplets propagating in a single extra dimension. This result is more successful and precise than that obtained from conventional supersymmetric grand unification, α s SGUT =0.130±0.004±Δ SGUT . There is a simultaneous solution to the three outstanding problems of 4D supersymmetric grand unified theories: a large mass splitting between Higgs doublets and their color triplet partners is forced, proton decay via dimension five operators is automatically forbidden, and the absence of fermion mass relations amongst light quarks and leptons is guaranteed, while preserving the successful m b /m τ relation. The theory necessarily has a strongly coupled top quark located on a fixed point and part of the lightest generation propagating in the bulk. The string and compactification scales are determined to be around 10 17 GeV and 10 15 GeV, respectively

Reason for SU(6) grand unification

International Nuclear Information System (INIS)

Kim, J.E.

1981-08-01

An SU(6) model can naturally guarantee strong CP invariance. This also includes Georgi and Glashow's SU(5) model. The axion in this model can be either invisible or visible, depending on the symmetry breaking scheme. The invisible axion is identical to a Majoron. Also, there exists a relationship between 24sub(H) and 45sub(H) of SU(5). (author)

LEP constraints on grand unified theories

International Nuclear Information System (INIS)

Sarkar, Utpal

1993-01-01

Recent developments on grand unified theories (GUTs) in the context of the LEP measurements of the coupling constants are reviewed. The three coupling constants at the electroweak scale have been measured at LEP quite precisely. One can allow these couplings to evolve with energy following the renormalization group equations for the various groups and find out whether all the coupling constants meet at any energy. It was pointed out that the minimal SU(5) grand unified theory fails to satisfy this test. However, various extensions of the theory are still allowed. These extensions include (i) supersymmetric SU(5) GUT, with some arbitrariness in the susy breaking scale arising from the threshold corrections, (ii) non-susy SU(5) GUTs with additional fermions as well as Higgs multiplets, which has masses of the order of TeV, and (iii) non-renormalizable effect of gravity with a fine tuned relation among the coupling constants at the unification energy. The LEP results also constrain GUTs with an intermediate symmetry breaking scale. By adjusting the intermediate symmetry breaking scale, one usually can have unification, but these theories get constrained. For example, the left-right symmetric theories coming from GUTs can be broken only at energies higher than about ∼10 10 GeV. This implies that if right handed gauge bosons are found at energies lower than this scale, then that will rule out the possibility of grand unification. Another recent interesting development on the subject, namely, low energy unification, is discussed in this context. All the coupling constants are unified at energies of the order of ∼10 8 GeV when they are embedded in an SU(15)GUT, with some particular symmetry breaking pattern. But even in this case the results of the intermediate symmetry breaking scale remain unchanged. (author). 16 refs., 3 figs

Leptoquark mechanism of neutrino masses within the grand unification framework

Science.gov (United States)

Doršner, Ilja; Fajfer, Svjetlana; Košnik, Nejc

2017-06-01

We demonstrate the viability of the one-loop neutrino mass mechanism within the framework of grand unification when the loop particles comprise scalar leptoquarks (LQs) and quarks of the matching electric charge. This mechanism can be implemented in both supersymmetric and non-supersymmetric models and requires the presence of at least one LQ pair. The appropriate pairs for the neutrino mass generation via the up-type and down-type quark loops are S_3-R_2 and S_{1, 3}-\\tilde{R}_2, respectively. We consider two distinct regimes for the LQ masses in our analysis. The first regime calls for very heavy LQs in the loop. It can be naturally realized with the S_{1, 3}-\\tilde{R}_2 scenarios when the LQ masses are roughly between 10^{12} and 5 × 10^{13} GeV. These lower and upper bounds originate from experimental limits on partial proton decay lifetimes and perturbativity constraints, respectively. Second regime corresponds to the collider accessible LQs in the neutrino mass loop. That option is viable for the S_3-\\tilde{R}_2 scenario in the models of unification that we discuss. If one furthermore assumes the presence of the type II see-saw mechanism there is an additional contribution from the S_3-R_2 scenario that needs to be taken into account beside the type II see-saw contribution itself. We provide a complete list of renormalizable operators that yield necessary mixing of all aforementioned LQ pairs using the language of SU(5). We furthermore discuss several possible embeddings of this mechanism in SU(5) and SO(10) gauge groups.

Leptoquark mechanism of neutrino masses within the grand unification framework

Energy Technology Data Exchange (ETDEWEB)

Dorsner, Ilja [University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture in Split (FESB), Split (Croatia); Fajfer, Svjetlana; Kosnik, Nejc [University of Ljubljana, Department of Physics, Ljubljana (Slovenia); Jozef Stefan Institute, Jamova 39, P. O. Box 3000, Ljubljana (Slovenia)

2017-06-15

We demonstrate the viability of the one-loop neutrino mass mechanism within the framework of grand unification when the loop particles comprise scalar leptoquarks (LQs) and quarks of the matching electric charge. This mechanism can be implemented in both supersymmetric and non-supersymmetric models and requires the presence of at least one LQ pair. The appropriate pairs for the neutrino mass generation via the up-type and down-type quark loops are S{sub 3}-R{sub 2} and S{sub 1,3}-R{sub 2}, respectively. We consider two distinct regimes for the LQ masses in our analysis. The first regime calls for very heavy LQs in the loop. It can be naturally realized with the S{sub 1,3}-R{sub 2} scenarios when the LQ masses are roughly between 10{sup 12} and 5 x 10{sup 13} GeV. These lower and upper bounds originate from experimental limits on partial proton decay lifetimes and perturbativity constraints, respectively. Second regime corresponds to the collider accessible LQs in the neutrino mass loop. That option is viable for the S{sub 3}-R{sub 2} scenario in the models of unification that we discuss. If one furthermore assumes the presence of the type II see-saw mechanism there is an additional contribution from the S{sub 3}-R{sub 2} scenario that needs to be taken into account beside the type II see-saw contribution itself. We provide a complete list of renormalizable operators that yield necessary mixing of all aforementioned LQ pairs using the language of SU(5). We furthermore discuss several possible embeddings of this mechanism in SU(5) and SO(10) gauge groups. (orig.)

Unification predictions

International Nuclear Information System (INIS)

Ghilencea, D.; Ross, G.G.; Lanzagorta, M.

1997-07-01

The unification of gauge couplings suggests that there is an underlying (supersymmetric) unification of the strong, electromagnetic and weak interactions. The prediction of the unification scale may be the first quantitative indication that this unification may extend to unification with gravity. We make a precise determination of these predictions for a class of models which extend the multiplet structure of the Minimal Supersymmetric Standard Model to include the heavy states expected in many Grand Unified and/or superstring theories. We show that there is a strong cancellation between the 2-loop and threshold effects. As a result the net effect is smaller than previously thought, giving a small increase in both the unification scale and the value of the strong coupling at low energies. (author). 15 refs, 5 figs

Phase transitions at finite chemical potential in grand unified theories

International Nuclear Information System (INIS)

Bailin, D.; Love, A.

1984-01-01

We discuss the circumstances in which non-zero chemical potentials might prevent symmetry restoration in phase transitions in the early universe at grand unification or partial unification scales. The general arguments are illustrated by consideration of SO(10) and SU(5) grand unified theories. (orig.)

SU(5) unification with TeV-scale leptoquarks

Energy Technology Data Exchange (ETDEWEB)

Cox, Peter [Kavli Institute for the Physics and Mathematics of the Universe (WPI), UTIAS,The University of Tokyo, Kashiwa, Chiba, 277-8583 (Japan); Kusenko, Alexander [Department of Physics and Astronomy, University of California,Los Angeles, CA, 90095-1547 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI), UTIAS,The University of Tokyo, Kashiwa, Chiba, 277-8583 (Japan); Sumensari, Olcyr [Laboratoire de Physique Théorique, CNRS, Université Paris-Sud, Université Paris-Saclay,Orsay, 91405 (France); Instituto de Física, Universidade de São Paulo,C.P. 66.318, São Paulo, 05315-970 (Brazil); Yanagida, Tsutomu T. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), UTIAS,The University of Tokyo, Kashiwa, Chiba, 277-8583 (Japan)

2017-03-07

It was previously noted that SU(5) unification can be achieved via the simple addition of light scalar leptoquarks from two split 10 multiplets. We explore the parameter space of this model in detail and find that unification requires at least one leptoquark to have mass below ≈16 TeV. We point out that introducing splitting of the 24 allows the unification scale to be raised beyond 10{sup 16} GeV, while a U(1){sub PQ} symmetry can be imposed to forbid dangerous proton decay mediated by the light leptoquarks. The latest bounds from LHC searches are combined and we find that a leptoquark as light as 400 GeV is still permitted. Finally, we discuss the interesting possibility that the leptoquarks required for unification could also be responsible for the 2.6σ deviation observed in the ratio R{sub K} at LHCb.

Local grand unification and string theory

International Nuclear Information System (INIS)

Nilles, Hans Peter; Vaudrevange, Patrick K.S.

2009-09-01

The low energy effective action of string theory depends strongly on the process of compactification and the localization of fields in extra dimensions. Explicit string constructions towards the minimal supersymmetric standard model (MSSM) reveal interesting results leading to the concept of local grand unification. Properties of the MSSM indicate that we might live at a special location close to an orbifold fixed point rather than a generic point in Calabi-Yau moduli space. We observe an enhancement of (discrete) symmetries that have various implications for the properties of the MSSM such as proton stability as well as solutions to the flavor problem, the m-problem and the strong CP-problem. (orig.)

Family unification in five and six dimensions

International Nuclear Information System (INIS)

Babu, K.S.; Barr, S.M.; Kyae, Bumseok

2002-01-01

In family unification models, all three families of quarks and leptons are grouped together into an irreducible representation of a simple gauge group, thus unifying the standard model gauge symmetries and a gauged family symmetry. Large orthogonal groups, and the exceptional groups E 7 and E 8 , have been much studied for family unification. The main theoretical difficulty of family unification is the existence of mirror families at the weak scale. It is shown here that family unification without mirror families can be realized in simple five-dimensional and six-dimensional orbifold models similar to those recently proposed for SU(5) and SO(10) grand unification. It is noted that a family unification group that survived to near the weak scale and whose coupling extrapolated to high scales unified with those of the standard model would be evidence, accessible in principle at low energy, of the existence of small (Planckian or GUT-scale) extra dimensions

The vacuum of the minimal nonsupersymmetric SO(10) unification

International Nuclear Information System (INIS)

Bertolini, Stefano; Di Luzio, Luca; Malinsky, Michal

2010-01-01

We study a class of nonsupersymmetric SO(10) grand-unified scenarios where the first stage of the symmetry breaking is driven by the vacuum expectation values of the 45-dimensional adjoint representation. Three-decade-old results claim that such a Higgs setting may lead exclusively to the flipped SU(5) x U(1) intermediate stage. We show that this conclusion is actually an artifact of the tree-level potential. The study of the accidental global symmetries emerging in various limits of the scalar potential offers a simple understanding of the tree-level result and a rationale for the drastic impact of quantum corrections. We scrutinize in detail the simplest and paradigmatic case of the 45 H +16 H Higgs sector triggering the breaking of SO(10) to the standard electroweak model. We show that the minimization of the one-loop effective potential allows for intermediate SU(4) C x SU(2) L x U(1) R and SU(3) c x SU(2) L x SU(2) R x U(1) B-L symmetric stages as well. These are the options favored by gauge unification. Our results, that apply whenever the SO(10) breaking is triggered by H >, open the path for hunting the simplest realistic scenario of nonsupersymmetric SO(10) grand unification.

A new flavour imprint of SU(5-like grand unification and its LHC signatures

Directory of Open Access Journals (Sweden)

S. Fichet

2015-03-01

Full Text Available We point out that the hypothesis of an SU(5-like supersymmetric Grand Unified Theory (GUT implies a generic relation within the flavour structure of up-type squarks. Contrary to other well-known SU(5 relations between the down-quark and charged lepton sectors, this relation remains exact in the presence of any corrections and extra operators. Moreover it remains valid to a good precision at the electroweak scale, and opens thus new possibilities for testing SU(5-like GUTs. We derive the low-energy effective theory of observable light up-type squarks, that also constitutes a useful tool for squark phenomenology. We use this effective theory to determine how to test SU(5 relations at the LHC. Focusing on scenarios with light stops, compatible with Natural SUSY, it appears that simple tests involving ratios of event rates are sufficient to test the hypothesis of an SU(5-like GUT theory. The techniques of charm-tagging and top-polarimetry are a crucial ingredient of these tests.

Reconciling grand unification with strings by anisotropic compactifications

International Nuclear Information System (INIS)

Dundee, Ben; Raby, Stuart; Wingerter, Akin

2008-01-01

We analyze gauge coupling unification in the context of heterotic strings on anisotropic orbifolds. This construction is very much analogous to effective five-dimensional orbifold grand unified theory field theories. Our analysis assumes three fundamental scales: the string scale M S , a compactification scale M C , and a mass scale for some of the vectorlike exotics M EX ; the other exotics are assumed to get mass at M S . In the particular models analyzed, we show that gauge coupling unification is not possible with M EX =M C , and in fact we require M EX C ∼3x10 16 GeV. We find that about 10% of the parameter space has a proton lifetime (from dimension six gauge exchange) 10 33 yr 0 e + ) 36 yr. The other 80% of the parameter space gives proton lifetimes below Super-Kamiokande bounds. The next generation of proton decay experiments should be sensitive to the remaining parameter space.

String unification and leptophobic Z` in flipped SU(5)

Energy Technology Data Exchange (ETDEWEB)

Lopez, J.L. [Rice Univ., Houston, TX (United States). Bonner Nuclear Labs.

1997-01-01

We summarize recent developments in the prediction for {alpha}{sub s}(M{sub Z}), self-consistent string unification and the dynamical determination of mass scales, and leptophobic Z` gauge bosons in the context of stringy flipped SU(5). (orig.).

Precision LEP data, supersymmetric GUTs and string unification

International Nuclear Information System (INIS)

Ellis, J.; Kelley, S.; Nanopoulos, D.V.; Houston Area Research Center

1990-01-01

The precision of sin 2 θ w MS (m Z ) extracted from LEP data (0.233±0.001) confirms the prediction of minimal supersymmetric GUTs (0.235±0.004) within the errors of about 2%. Moreover, supersymmetric GUTs with three generations and a heavy top quark also predict m b =5.2±0.3 GeV in perfect agreement with potential model estimates (5.0±0.2 GeV). String unification would require that the effective grand unification scale m GUT be no larger than the effective string unification scale m SU , which is indeed consistent with the LEP data, which indicate m GUT ≅ 2x10 16 GeV in a minimal supersymmetric GUT, compared with the theoretical estimate m SU ≅ 10 17 GeV. Specific choices of the string model moduli could enforce m GUT =m SU even in minimal supersymmetric GUTs, whilst non-minimal supersymmetric GUTs can reconcile the successful predictions of sin 2 θ w with m GUT = m SU for generic values of the moduli, but tend to have m b too large. (orig.)

Probing the design of grand unification through conservation laws

International Nuclear Information System (INIS)

Pati, J.C.

1981-01-01

The purpose of this talk is to note a few special consequences of gauging ''maximal'' quark-lepton symmetries such as SO(16), which is the maximal symmetry for a single family of fermions. Within these symmetries, violations for B, L and F are spontaneous rather than explicit. Furthermore these symmetries as a rule permit intermediate mass scales approx.(10 3 -10 6 GeV) and (10 8 -10 11 GeV) filling the so-called grand plateau between 10 2 and 10 15 GeV. It has been shown in earlier papers that within these symmetries proton may decay via four alternative models: i.e. proton→one or three leptons or antileptons plus mesons; some of which can coexist. It is now observed that even n-n-bar oscillations can coexist with (B-L) conserving proton-decays of the type p→e + π 0 etc. without posing any conflict with the cosmological generation of baryon-excess; both these processes can possess measurable strengths so as to be amenable to forthcoming searches. Search for alternative decay modes of proton and n-n-bar oscillations, even as processes in second and third generation experiments, would provide valuable information on the question of intermediate mass-scales and thereby on the design of grand unification

Bounds on the number of possible Higgs particles using grand unification and exceptional Lie groups

International Nuclear Information System (INIS)

El Naschie, M.S.

2008-01-01

The total sum of dimensions of a magnum exceptional Lie symmetry groups hierarchy is 4α-bar o =(4)(137+k o )≅548. Dividing this value among the various quantum fields leads to the possibility of an eight degrees of freedom Higgs field. However analyzing the same situation using sub groups of the largest exceptional Lie group leads to the conclusion that we are likely to find three Higgs particles only at the energy scale of the standard model. Consequently five of the eight degrees of freedom are unlikely to materialize as particles at this particular energy scale. This conclusion is reinforced by an entirely different approach based on grand unification analysis which excludes any grand unification using 4HD, i.e. four Higgs doublets. This leaves us with one, two and three Higgs doublets. Noting that a super symmetric standard model with two Higgs doublets gives almost perfect grand unification and that the result agrees with our exceptional Lie symmetry groups analysis, we exclude everything else. The final result is that we expect to find at least three more Higgs particles leading to a total of 66 elementary particles while at a somewhat higher energy, the expected number of 69 particles found using E-infinity theory is obtained

Grand unification and supergravity

International Nuclear Information System (INIS)

Nanopoulos, D.V.

Grand Unified Theories (GUTs) are very successful, but they suffer from fine-tuning or hierarchy problems. It seems that more symmetry beyond the gauge symmetry is needed and indeed supersymmetric GUTs may provide the correct framework in solving the hierarchy problems. These are reviewed. From the results discussed, it is seen that for the first time in particle physics, gravity seems to play a dominant role. It may be responsible for GUT breaking, SU(2) x U(1) breaking, fermion masses, proton decay and a consistent cosmological picture. Supergravity seems to offer a consistent, effective theory for energies below the Planck scale to N=1 local SUSY but also, in the context of N=8 extended supergravity with a dynamically realized SU(8), there may be a consistent fundamental unified theory of all interactions. (U.K.)

Direct mediation, duality and unification

International Nuclear Information System (INIS)

Abel, Steven; Khoze, Valentin V.

2008-01-01

It is well-known that in scenarios with direct gauge mediation of supersymmetry breaking the messenger fields significantly affect the running of Standard Model couplings and introduce Landau poles which are difficult to avoid. Among other things, this appears to remove any possibility of a meaningful unification prediction and is often viewed as a strong argument against direct mediation. We propose two ways that Seiberg duality can circumvent this problem. In the first, which we call 'deflected-unification', the SUSY-breaking hidden sector is a magnetic theory which undergoes a Seiberg duality to an electric phase. Importantly, the electric version has fewer fundamental degrees of freedom coupled to the MSSM compared to the magnetic formulation. This changes the β-functions of the MSSM gauge couplings so as to push their Landau poles above the unification scale. We show that this scenario is realised for recently suggested models of gauge mediation based on a metastable SCQD-type hidden sector directly coupled to MSSM. The second possibility for avoiding Landau poles, which we call 'dual-unification', begins with the observation that, if the mediating fields fall into complete SU(5) multiplets, then the MSSM+messengers exhibits a fake unification at unphysical values of the gauge couplings. We show that, in known examples of electric/magnetic duals, such a fake unification in the magnetic theory reflects a real unification in the electric theory. We therefore propose that the Standard Model could itself be a magnetic dual of some unknown electric theory in which the true unification takes place. This scenario maintains the unification prediction (and unification scale) even in the presence of Landau poles in the magnetic theory below the GUT scale. We further note that this dual realization of grand unification can explain why Nature appears to unify, but the proton does not decay.

Present status of SU(5)-based grand unifications

International Nuclear Information System (INIS)

Ahmad, S.M.W.

1990-10-01

This paper is a brief communique on the Georgi-Glashow SU(5) paper: Unity of all Elementary Forces, published in 1974; and the other more important papers based on SU(5) or linked with the Georgi-Glashow paper which was welcomed by many a theoretical physicist as a great step. At the end of the paper, a concise review of the experiments (in operation) and the proposed ones is given. (author). 22 refs

Grand unification in the projective plane

International Nuclear Information System (INIS)

Hebecker, A.

2004-01-01

A 6-dimensional grand unified theory with the compact space having the topology of a real projective plane, i.e., a 2-sphere with opposite points identified, is considered. The space is locally flat except for two conical singularities where the curvature is concentrated. One supersymmetry is preserved in the effective 4d theory. The unified gauge symmetry, for example SU(5), is broken only by the non-trivial global topology. In contrast to the Hosotani mechanism, no adjoint Wilson-line modulus associated with this breaking appears. Since, locally, SU(5) remains a good symmetry everywhere, no UV-sensitive threshold corrections arise and SU(5)-violating local operators are forbidden. Doublet-triplet splitting can be addressed in the context of a 6d N=2 super Yang-Mills theory with gauge group SU(6). If this symmetry is first broken to SU(5) at a fixed point and then further reduced to the standard model group in the above non-local way, the two light Higgs doublets of the MSSM are predicted by the group-theoretical and geometrical structure of the model. (author)

Relict gravitational waves in the expanding Universe model and the grand unification scale

International Nuclear Information System (INIS)

Veryskin, A.V.; Rubakov, V.A.; Sazhin, M.V.

1983-01-01

The amplification of the vacuum fluctuations of the metric in the model of the expanding Universe was considered. The spectrum of the relict gravitational waves was chosen to be independent from the details of an evolution of the Universe after the phase transition. It is shown that the expanding Universe scenario is compatible with the experimental data on the anisotropy of the microwave background only if the vacuum energy density of the symmetric phase is much less than the Planck one. The theories of grand unification with not large values of the unification scale (one and a half order less than the Planck mass) are preferable from the point of view of cosmology

SU(5)×U(1)X grand unification with minimal seesaw and Z‧-portal dark matter

Science.gov (United States)

Okada, Nobuchika; Okada, Satomi; Raut, Digesh

2018-05-01

We propose a grand unified SU (5) × U(1)X model, where the standard SU(5) grand unified theory is supplemented by minimal seesaw and a right-handed neutrino dark matter with an introduction of a global Z2-parity. In the presence of three right-handed neutrinos (RHNs), the model is free from all gauge and mixed-gravitational anomalies. The SU(5) symmetry is broken into the Standard Model (SM) gauge group at MGUT ≃ 4 ×1016GeV in the standard manner, while the U(1)X symmetry breaking occurs at the TeV scale, which generates the TeV-scale mass of the U(1)X gauge boson (Z‧ boson) and the three Majorana RHNs. A unique Z2-odd RHN is stable and serves as the dark matter (DM) in the present Universe, while the remaining two RHNs work to generate the SM neutrino masses through the minimal seesaw. We investigate the Z‧-portal RHN DM scenario in this model context. We find that the constraints from the DM relic abundance, and the Z‧ boson search at the Large Hadron Collider (LHC), and the perturbativity bound on the U(1)X gauge coupling are complementary to narrow down the allowed parameter region in the range of 3.0 ≤mZ‧ [TeV ] ≤ 9.2 for the Z‧ boson mass. The allowed region for mZ‧ ≤ 5TeV will be fully covered by the future LHC experiments. We also briefly discuss the successful implementation of Baryogenesis and cosmological inflation scenarios in the present model.

New Developments in Supersymmetry (1/5)

CERN Multimedia

CERN. Geneva

2001-01-01

Introduction to supersymmetric grand unified theories. An introduction to the MSSM and different mechanisms for supersymmetry breaking. Then the details of SU(5) and SO(10) unification, the new gauge sector beyond the standard model, representations of quarks and leptons. Gauge and Yukawa coupling unification and some predictions.

Low-energy parity restoration and unification mass scale within maximal symmetries

Directory of Open Access Journals (Sweden)

Ajaya K. Mohanty

1984-01-01

Full Text Available We investigate the hierarchy of gauge boson masses in the maximal grand unified theory by studying the renormalization group equations for the running coupling constants associated with the symmetry breaking of SU(16viaSU(12 q×SU(4 l×U(1 |B|−|L| chain. Particular attention is given to the contribution of Higgs scalars to these equations. It is found that the intermediate mass scale ML, associated with right-handed gauge bosons could be as low as 10 3 GeV only for sin 2θ w(M L as high as 0.265 with α s(M L=0.13. In this chain of symmetry breaking, we have also examined the lowest unification mass that is allowed by the low-energy data for sin 2θ w(M L and the assumed gauge hierarchy. This has been done in two cases; first for the case where SU(3 c is vectorial, second, for the case where SU(3 c is axial. In both cases the lowest unification mass scales were found to be 10 13, 10 11, 10 8 and 10 7 GeV for sin 2θ w(M L = 0.22, 0.24, 0.26,and0.265 respectively with α s(M L = 0.13. The implication of these low unification masses on baryon non-conserving processes is also discussed.

Gauge coupling unification in realistic free-fermionic string models

International Nuclear Information System (INIS)

Dienes, K.R.; Faraggi, A.E.

1995-01-01

We discuss the unification of gauge couplings within the framework of a wide class of realistic free-fermionic string models which have appeared in the literature, including the flipped SU(5), SO(6)xSO(4), and various SU(3)xSU(2)xU(1) models. If the matter spectrum below the string scale is that of the Minimal Supersymmetric Standard Model (MSSM), then string unification is in disagreement with experiment. We therefore examine several effects that may modify the minimal string predictions. First, we develop a systematic procedure for evaluating the one-loop heavy string threshold corrections in free-fermionic string models, and we explicitly evaluate these corrections for each of the realistic models. We find that these string threshold corrections are small, and we provide general arguments explaining why such threshold corrections are suppressed in string theory. Thus heavy thresholds cannot resolve the disagreement with experiment. We also study the effect of non-standard hypercharge normalizations, light SUSY thresholds, and intermediate-scale gauge structure, and similarly conclude that these effects cannot resolve the disagreement with low-energy data. Finally, we examine the effects of additional color triplets and electroweak doublets beyond the MSSM. Although not required in ordinary grand unification scenarios, such states generically appear within the context of certain realistic free-fermionic string models. We show that if these states exist at the appropriate thresholds, then the gauge couplings will indeed unify at the string scale. Thus, within these string models, string unification can be in agreement with low-energy data. (orig.)

SU(n)c x SU(m)L x U(1)N generalizations of the standard model

International Nuclear Information System (INIS)

Pleitez, V.

1993-01-01

Generalizations of the Standard Model which are based on the gauge symmetry SU(n) c x SU(m) L x U(1) N are considered. Although the most interesting possibility occurs when n = 3, it will be considered also the cases n = 4,5, both with m = 3,4. It will also be given possible grand unification scenarios. (author). 18 refs

Implications of results from the CERN e+e- collider LEP for SO(10) grand unification with two intermediate stages

International Nuclear Information System (INIS)

Deshpande, N.G.; Keith, E.; Pal, P.B.

1993-01-01

We consider the breaking of the grand unification group SO(10) to the standard model gauge group through several chains containing two intermediate stages. Using the values of the gauge coupling constants at a scale M Z derived from recent data from the CERN e + e- collider LEP, we determine the range of their intermediate and unification scales. In particular, we identify those chains that permit new gauge structure at relatively low energy (∼1 TeV)

Dynkin weights and global supersymmetry in grand unification

International Nuclear Information System (INIS)

Frampton, P.H.; Kephart, T.W.

1982-01-01

The requirement that supersymmetry be unbroken in a supersymmetrized gauge theory is shown to imply vanishing Dynkin weight of the components of the Higgs field representation receiving vacuum expectation values. As a corollary a compact expression is obtained for the Dynkin weights of general SU(N) representations. Examples are given for supersymmetrized grand unified theories

Grand unification and the fundamental problems of classical cosmology

International Nuclear Information System (INIS)

Turner, M.S.

1981-01-01

The accomplishments of classical cosmology are reviewed. In particular, the hot big bang model provides a reliable framework for understanding the evolution of the universe back to times at least as early as approx. 0.01 s after the big bang. At present there are (at least) six fundamental problems which have not yet been (completely) resolved. They are: (1) the origin of the baryon number-to-entropy ratio, (2) the origin of the isotropy, (3) the origin of the homogeneity and inhomogeneity, (4) the origin of the flatness, (5) the cosmological constant, and (6) the monopole problem. The role that grand unification has played, and may play in the resolution of these puzzles is discussed. Guth's inflationary universe, which addresses five of these six problems, is reviewed

Local grand unification in the heterotic landscape

International Nuclear Information System (INIS)

Schmidt, Jonas

2009-06-01

We consider the possibility that the unification of the electroweak interactions and the strong force arises from string theory, at energies significantly lower than the string scale. As a tool, an effective grand unified field theory in six dimensions is derived from an anisotropic orbifold compactification of the heterotic string. It is explicitly shown that all anomalies cancel in the model, though anomalous Abelian gauge symmetries are present locally at the boundary singularities. In the supersymmetric vacuum additional interactions arise from higher-dimensional operators. We develop methods that relate the couplings of the effective theory to the location of the vacuum, and find that unbroken discrete symmetries play an important role for the phenomenology of orbifold models. An efficient algorithm for the calculation of the superpotential to arbitrary order is developed, based on symmetry arguments. We furthermore present a correspondence between bulk fields of the orbifold model in six dimensions, and the moduli fields that arise from compactifying four internal dimensions on a manifold with non-trivial gauge background. (orig.)

Local grand unification in the heterotic landscape

Energy Technology Data Exchange (ETDEWEB)

Schmidt, Jonas

2009-07-15

We consider the possibility that the unification of the electroweak interactions and the strong force arises from string theory, at energies significantly lower than the string scale. As a tool, an effective grand unified field theory in six dimensions is derived from an anisotropic orbifold compactification of the heterotic string. It is explicitly shown that all anomalies cancel in the model, though anomalous Abelian gauge symmetries are present locally at the boundary singularities. In the supersymmetric vacuum additional interactions arise from higher-dimensional operators. We develop methods that relate the couplings of the effective theory to the location of the vacuum, and find that unbroken discrete symmetries play an important role for the phenomenology of orbifold models. An efficient algorithm for the calculation of the superpotential to arbitrary order is developed, based on symmetry arguments. We furthermore present a correspondence between bulk fields of the orbifold model in six dimensions, and the moduli fields that arise from compactifying four internal dimensions on a manifold with non-trivial gauge background. (orig.)

Unification beyond GUT's: Gauge-Yukawa unification

International Nuclear Information System (INIS)

Kubo, J.; Mondragon, M.; Zoupanos, G.

1996-01-01

Gauge-Yukawa Unification (GYU) is a renormalization group invariant functional relation among gauge and Yukawa couplings which holds beyond the unification point in Grand Unified Theories (GUTs). We present here various models where GYU is obtained by requiring the principles of finiteness and reduction of couplings. We examine the consequences of these requirements for the low energy parameters, especially for the top quark mass. The predictions are such that they clearly distinguish already GYU from ordinary GUTs. It is expected that it will be possible to discriminate among the various GYUs when more accurate measurements of the top quark mass are available. (author)

Dark matter as the signal of grand unification

International Nuclear Information System (INIS)

Kadastik, Mario; Kannike, Kristjan; Raidal, Martti

2009-01-01

We argue that the existence of dark matter (DM) is a possible consequence of grand unification (GUT) symmetry breaking. In GUTs like SO(10), discrete Z 2 matter parity (-1) 3(B-L) survives despite broken B-L, and group theory uniquely determines that the only possible Z 2 -odd matter multiplets belong to representation 16. We construct the minimal nonsupersymmetric SO(10) model containing one scalar 16 for DM and study its predictions below M G . We find that electroweak symmetry breaking occurs radiatively due to DM couplings to the standard model Higgs boson. For thermal relic DM the mass range M DM ∼O(0.1-1) TeV is predicted by model perturbativity up to M G . For M DM ∼O(1) TeV to explain the observed cosmic ray anomalies with DM decays, there exists a lower bound on the spin-independent direct detection cross section within the reach of planned experiments.

Neutrino masses and large mixings as a indirect signature of grand unified theory

International Nuclear Information System (INIS)

Maekawa, Nobuhiro

2015-01-01

Grand unified theory (GUT) unifies not only three forces (electromagnetic force, strong force and weak force) but also quarks and leptons. As an experimental support for the unification of forces, it is well-known that three gauge couplings meet at a scale (the GUT scale). However, it is not so well-known that there is an experimental support even for the unification of matters (quarks and leptons). We explain the indirect support in this document and show that the important key is what the neutrino experiments have revealed for 20 years. Concretely, for the unification of matters in SU(5) GUT, various observed hierarchies of quark and lepton masses and mixings can be understood only from one assumption that '10 dimensional fields of SU(5) induce stronger hierarchy for the Yukawa couplings than 5-bar fields'. For this explanation, the knowledges on neutrino masses and mixings are critical. In the end, we comment E 6 unification in which the above assumption in the SU(5) GUT can be induced. (author)

Study of theory and phenomenology of some classes of family symmetry and unification models

International Nuclear Information System (INIS)

Kane, Gordon L.; King, Steve F.; Peddie, Iain N.R.; Velasco-Sevilla, Liliana

2005-01-01

We review and compare theoretically and phenomenologically a number of possible family symmetries, which when combined with unification, could be important in explaining quark, lepton and neutrino masses and mixings, providing new results in several cases. Theoretical possibilities include abelian or non-abelian, symmetric or non symmetric Yukawa matrices, Grand Unification or not. Our main focus is on anomaly-free U(1) family symmetry combined with SU(5) unification, although we also discuss other possibilities. We provide a detailed phenomenological fit of the fermion masses and mixings for several examples, and discuss the supersymmetric flavour issues in such theories, including a detailed analysis of lepton flavour violation. We show that it is not possible to quantitatively and decisively discriminate between these different theoretical possibilities at the present time

Simple unification

International Nuclear Information System (INIS)

Ponce, W.A.; Zepeda, A.

1987-08-01

We present the results obtained from our systematic search of a simple Lie group that unifies weak and electromagnetic interactions in a single truly unified theory. We work with fractionally charged quarks, and allow for particles and antiparticles to belong to the same irreducible representation. We found that models based on SU(6), SU(7), SU(8) and SU(10) are viable candidates for simple unification. (author). 23 refs

Gravity-assisted exact unification in minimal supersymmetric SU(5) and its gaugino mass spectrum

International Nuclear Information System (INIS)

Tobe, Kazuhiro; Wells, James D.

2004-01-01

Minimal supersymmetric SU(5) with exact unification is naively inconsistent with proton decay constraints. However, it can be made viable by a gravity-induced non-renormalizable operator connecting the adjoint Higgs boson and adjoint vector boson representations. We compute the allowed coupling space for this theory and find natural compatibility with proton decay constraints even for relatively light superpartner masses. The modifications away from the naive SU(5) theory have an impact on the gaugino mass spectrum, which we calculate. A combination of precision linear collider and large hadron collider measurements of superpartner masses would enable interesting tests of the high-scale form of minimal supersymmetric SU(5)

The behaviour of effective coupling constants in 'finite' grand unification theories in curved spacetime

International Nuclear Information System (INIS)

Buchbinder, I.L.; Odintsov, S.D.; Lichtzier, I.M.

1989-01-01

The question of the behaviour of effective coupling constants in one-loop 'finite' grand unification theories in curved spacetime is investigated. It is shown that in strong gravitational fields the effective coupling constant, corresponding to the parameter of non-minimal interaction of scalar and gravitational fields, tends to the conformal value or increases in an exponential fashion. The one-loop effective potential is obtained with accuracy to linear curvature terms. It is shown that, in external supergravity, supersymmetric finite theories admit asymptotic conformal invariance. (Author)

Symmetry hierarchies and radiative corrections in the grand unified model SU(8)/sub L/ x SU(8)/sub R/

International Nuclear Information System (INIS)

Pirogov, Y.F.

1982-01-01

In the SU(8)/sub L/ x SU(8)/sub R/ model of precocious chiral unification, radiative corrections for the effective parameters sin 2 theta/sub W/(μ) and α(μ) are calculated in the one-loop approximation, neglecting contributions of the Higgs fields, and the unification mass M 8 is determined in the presence of a hierarchy of intermediate symmetries. It is shown that a natural hierarchy exists which leads to a decrease in sin 2 theta/sub W/(M/sub W/L) down to the value sin 2 theta/sub W/ = (1/5)--(1/4) together with a decrease in M 8 down to M 8 = 10 6 --10 7 GeV in comparison with the values in the absence of a hierarchy

On symmetry hierarchy and radiative corrections in the grand unified model SU(8)sub(L)xSU(8)sub(R)

International Nuclear Information System (INIS)

Pirogov, Yu.F.

1982-01-01

In the model of precocious chiral unification SU(8)sub(L)xSU(8)sub(R) radiative corrections are calculated for the effective parameters sin 2 thetaw(μ) and α(μ) and the unification mass M 8 is determifed in presence of a hierarchy of intermediate symmetries. The one-loop approximation is used and contributions from the Higgs fields are neglected. It is shown that a natural hierarchy exists leading to a decrease of sinsup(2)thetasub(w)(Msub(wsub(L))) up to sinsup(2)thetasub(w)=1/5-1/4 together with a decrease of M 8 up to M 8 =10 6 -10 7 GeV, as compared with the magnitudes without the hierarchy [ru

Infrared fixed points and fixed lines in the top-bottom-tau sector in supersymmetric grand unification

International Nuclear Information System (INIS)

Schrempp, B.

1994-10-01

The two loop 'top-down' renormalization group flow for the top, bottom and tau Yukawa couplings, from μ=M GUT ≅O(10 16 GeV) to μ≅m t , is explored in the framework of supersymmetric grand unification; reproduction of the physical bottom and tau masses is required. Instead of following the recent trend of implementing exact Yukawa coupling unification i) a search for infrared (IR) fixed lines and fixed points in the m t pole -tan β plane is performed and ii) the extent to which these imply approximate Yukawa unification is determined. In the m t pole -tan β plane two IR fixed lines, intersecting in an IR fixed point, are located. The more attractive fixed line has a branch of almost constant top mass, m t pole ≅168≅180 GeV (close to the experimental value), for the large interval 2.5 GUT approximately. The less attractive fixed line as well as the fixed point at m t pole ≅170 GeV, tan β≅55 implement approximate top-bottom Yukawa unification at all scales μ. The renormalization group flow is attracted towards the IR fixed point by way of the more attractive IR fixed line. The fixed point and lines are distinct from the much quoted effective IR fixed point m t pole ≅O(200 GeV) sin β. (orig.)

The subgroup structure of grand unified theories with application to the fermion mass matrix in 0(10)

International Nuclear Information System (INIS)

Feldman, G.; Fulton, T.

1982-01-01

A technique, using the orthonormal basis for roots and weights of compact Lie groups, introduced by Van der Waerden and developed by Dynkin (Am. Math. Soc. Transl.; 17: (1950) and Sec 2,6:111 (1957)) provides a convenient framework for discussing mass relations in grand unification theories. The structure constants Nsub(αβ) for SU(R + 1), O(2R + 1), Sp(2R), O(2R) and G(2) are obtained in an appendix, using an approach arising from this basis. The method for obtaining generators of non-regular subalgebras, in terms of generators of the original algebras, is discussed in terms of the basis. It is necessary to know this structure in order to trace the history of particles, originally in some grand unification group, through the various chains of decompositions into subgroups. As an illustration, the methods are applied to finding the minimal, non-trivial, mass relations for fermions in the O(10) grand unification scheme. (author)

Finite Unification: Theory, Models and Predictions

CERN Document Server

Heinemeyer, S; Zoupanos, G

2011-01-01

All-loop Finite Unified Theories (FUTs) are very interesting N=1 supersymmetric Grand Unified Theories (GUTs) realising an old field theory dream, and moreover have a remarkable predictive power due to the required reduction of couplings. The reduction of the dimensionless couplings in N=1 GUTs is achieved by searching for renormalization group invariant (RGI) relations among them holding beyond the unification scale. Finiteness results from the fact that there exist RGI relations among dimensional couplings that guarantee the vanishing of all beta-functions in certain N=1 GUTs even to all orders. Furthermore developments in the soft supersymmetry breaking sector of N=1 GUTs and FUTs lead to exact RGI relations, i.e. reduction of couplings, in this dimensionful sector of the theory, too. Based on the above theoretical framework phenomenologically consistent FUTs have been constructed. Here we review FUT models based on the SU(5) and SU(3)^3 gauge groups and their predictions. Of particular interest is the Hig...

Advantages of unity with SU(4)-color: Reflections through neutrino oscillations, baryogenesis and proton decay

Science.gov (United States)

Pati, Jogesh C.

2017-03-01

By way of paying tribute to Abdus Salam, I first recall the ideas of higher unification which the two of us introduced in 1972-73 to remove certain shortcomings in the status of particle physics prevailing then, and then present their current role in theory as well as experiments. These attempts initiated the idea of grand unification and provided the core symmetry-structure G(2, 2, 4) = SU(2)L × SU(2)R × SU(4)-color towards such a unification. Embodied with quark-lepton unification and left-right symmetry, the symmetry G(2, 2, 4) is uniquely chosen as being the minimal one that permits members of a family to belong to a single multiplet. The minimal extension of G(2, 2, 4) to a simple group is given by the attractive SO(10)-symmetry that was suggested a year later. The new concepts, and the many advantages introduced by this core symmetry (which are, of course, retained by SO(10) as well) are noted. These include explanations of the observed: (i) (rather weird) electroweak and color quantum numbers of the members of a family; (ii) quantization of electric charge; (iii) electron-proton charge-ratio being - 1; (iv) the co-existence of quarks and leptons; (v) likewise that of the three basic forces — the weak, electromagnetic and strong; (vi) the non-trivial cancelation of the triangle anomalies within each family; and opening the door for (vii) the appealing concept of parity being an exact symmetry of nature at the fundamental level. In addition, as a distinguishing feature, both because of SU(4)-color and independently because of SU(2)R as well, the symmetry G(2, 2, 4) introduced, to my knowledge, for the first time in the literature: (viii) a new kind of matter — the right-handed (RH) neutrino (νR) — as a compelling member of each family, and together with it; (ix) (B-L) as a local symmetry. The RH neutrions — contrary to prejudices held in the 1970’s against neutrinos being massive and thereby against the existence of νR’s as well — have in

Family unification within SO(15)

International Nuclear Information System (INIS)

Enqvist, K.; Maalampi, J.

1981-01-01

We present a model for the unification of fermion families based on the gauge symmetry SO(15). It is a minimal SO(n) model which can accommodate the known fermions within a single irreducible representation. The model predicts four ordinary fermion families and four families of mirror fermions. The latter have V + A weak interactions, and their mass scale is predicted to be 10 2 GeV/c 2 . We argue that radiative corrections to the fermion masses can cause non-negligible mixing between ordinary and mirror fermions. The implications of these mixings for the weak interaction phenomenology and solar neutrinos are discussed. (orig.)

Electroweak symmetry breaking and mass spectra in six-dimensional gauge-Higgs grand unification

Science.gov (United States)

Hosotani, Yutaka; Yamatsu, Naoki

2018-02-01

The mass spectra of the standard model particles are reproduced in the SO(11) gauge-Higgs grand unification in six-dimensional warped space without introducing exotic light fermions. Light neutrino masses are explained by the gauge-Higgs seesaw mechanism. We evaluate the effective potential of the four-dimensional Higgs boson appearing as a fluctuation mode of the Aharonov-Bohm phase θ_H in the extra-dimensional space, and show that the dynamical electroweak symmetry breaking takes place with the Higgs boson mass m_H ˜ 125 GeV and θ_H ˜ 0.1. The Kaluza-Klein mass scale in the fifth dimension is approximately given by m_KK ˜ 1.230 TeV/sin θ_H.

Stability of mass hierarchy in locally supersymmetric grand unification

International Nuclear Information System (INIS)

Nishino, H.; Helayel-Neto, J.A.; Koh, I.G.

1984-06-01

Some locally supersymmetric SU(5) grand unified models with a sliding singlet and two pairs of 5sub(tilde) and 5sub(tilde)* Higgs multiplets are considered from the viewpoint of universal baryon asymmetry and the one-loop stability of mass hierarchy. A new mechanism based on ''sliding singlet reflection symmetry'' to avoid the problem of the mass hierarchical stability is proposed. The stability is shown up to two-loop levels for some models. All order stability is also discussed. (author)

Unification of SUSY breaking and GUT breaking

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Tatsuo [Department of Physics, Hokkaido University,Sapporo 060-0810 (Japan); Omura, Yuji [Department of Physics, Nagoya University,Nagoya 464-8602 (Japan)

2015-02-18

We build explicit supersymmetric unification models where grand unified gauge symmetry breaking and supersymmetry (SUSY) breaking are caused by the same sector. Besides, the SM-charged particles are also predicted by the symmetry breaking sector, and they give the soft SUSY breaking terms through the so-called gauge mediation. We investigate the mass spectrums in an explicit model with SU(5) and additional gauge groups, and discuss its phenomenological aspects. Especially, nonzero A-term and B-term are generated at one-loop level according to the mediation via the vector superfields, so that the electro-weak symmetry breaking and 125 GeV Higgs mass may be achieved by the large B-term and A-term even if the stop mass is around 1 TeV.

Grand unification and the double beta-decay

International Nuclear Information System (INIS)

Faessler, A.

1992-01-01

Models of the unification of the electroweak and the strong interaction predict that the neutrino is a Majorana particle and therefore essentially identical with its own antiparticle. In such grand unified models the neutrino has also a finite mass and a slight right-handed weak interaction, since the model is left-right symmetric. These models have also left handed and right-handed vector bosons to mediate the weak interactions. If these models are correct the neutrinoless double beta-decay is feasable. Thus if one finds the neutrinoless double beta-decay one knows that the standard model can not be correct in which the neutrino is a Dirac particle and therefore different from its antiparticle. Although the neutrinoless double beta-decay has not been seen it is possible to extract from the lower limits of the lifetime against the double neutrinoless beta-decay upper limits for the effective electron-neutrino mass and for the effective mixing angle of the right-handed and the left-handed vector bosons mediating the weak interaction. One also can obtain an effective upper limit for the mass ratio of the light and the heavy vector bosons. The extraction of this physical quantities from the data is made difficult due to the fact that the weak interaction must not be diagonal in the representation of the mass matrix of the six neutrinos requested by such left-right symmetric models. (author)

Decaying dark matter in supersymmetric SU(5) models

International Nuclear Information System (INIS)

Luo Mingxing; Wang Liucheng; Wu Wei; Zhu Guohuai

2010-01-01

Motivated by recent observations from PAMELA, Fermi and H.E.S.S., we consider dark matter decays in the framework of supersymmetric SU(5) grand unification theories. An SU(5) singlet S is assumed to be the main component of dark matters, which decays into visible particles through dimension six operators suppressed by the grand unification scale. Under certain conditions, S decays dominantly into a pair of sleptons with universal coupling for all generations. Subsequently, electrons and positrons are produced from cascade decays of these sleptons. These cascade decay chains smooth the e + +e - spectrum, which permit naturally a good fit to the Fermi-LAT data. The observed positron fraction upturn by PAMELA can be reproduced simultaneously. We have also calculated diffuse gamma-ray spectra due to the e ± excesses and compared them with the preliminary Fermi-LAT data from 0.1 GeV to 10 GeV in the region 0 deg. ≤l≤ 360 deg., 10 deg. ≤|b|≤20 deg. The photon spectrum of energy above 100 GeV, mainly from final state radiations, may be checked in the near future.

Gauge hierarchy in an SO(10) supersymmetric grand unified model

International Nuclear Information System (INIS)

Zhiyong, Z.

1982-01-01

An SO(10) supersymmetric grand unified model is constructed in which the gauge hierarchy problem may be solved. Using Higgs superfields belonging to the SO(10) representations 16, 10 and 54, it is found that if SO(10) is broken down to SU(3)sub(c)xSU(2)sub(L)xU(1) via SO(6)xSO(4)approximately equal to SU(4)sub(c)xSU(2)sub(L)xSU(2)sub(R) at unification mass scales without supersymmetry breaking, the gauge hierarchy puzzle might be carried away. It is also shown that the colour-triplet Higgs, which mediates proton decay, is superheavy by an incredibly accurate, but 'natural' adjustment of parameters in the potential. (author)

On the vacuum of the minimal nonsupersymmetric SO(10) unification

CERN Document Server

Bertolini, Stefano; Malinsky, Michal

2010-01-01

We study a class of nonsupersymmetric SO(10) grand unified scenarios where the first stage of the symmetry breaking is driven by the vacuum expectation values of the 45-dimensional adjoint representation. Three decade old results claim that such a Higgs setting may lead exclusively to the flipped SU(5) x U(1) intermediate stage. We show that this conclusion is actually an artifact of the tree level potential. The study of the accidental global symmetries emerging in various limits of the scalar potential offers a simple understanding of the tree level result and a rationale for the drastic impact of quantum corrections. We scrutinize in detail the simplest and paradigmatic case of the 45_{H} + 16_{H} Higgs sector triggering the breaking of SO(10) to the standard electroweak model. We show that the minimization of the one-loop effective potential allows for intermediate SU(4)_C x SU(2)_L x U(1)_R and SU(3)_c x SU(2)_L x SU(2)_R x U(1)_{B-L} symmetric stages as well. These are the options favoured by gauge unif...

Cosmological implications of grand unified theories

International Nuclear Information System (INIS)

Nanopoulos, D.V.

1982-01-01

These lectures, mainly devoted to the cosmological implications of GUTs, also include the essential ingredients of GUTs and some of their important applications to particle physics. Section 1 contains some basic points concerning the structure of the standard strong and electroweak interactions prior to grand unification. A detailed expose of GUTs is attempted in sect. 2, including their basci principles and their consequences for particle physics. The minimal, simplest GUT, SU 5 is analysed in some detail and it will be used throughout these lectures as the GUT prototype. Finally, sect. 3 contains the most important cosmological implications of GUTs, including baryon number generation in the early Universe (in rather lengthy detail), dissipative processes in the very early Universe, grand unified monopoles, etc. (orig./HSI)

Revisiting top-bottom-tau Yukawa unification in supersymmetric grand unified theories

International Nuclear Information System (INIS)

Tobe, Kazuhiro; Wells, James D.

2003-01-01

Third family Yukawa unification, as suggested by minimal SO(10) unification, is revisited in light of recent experimental measurements and theoretical progress. We characterize unification in a semi-model-independent fashion, and conclude that finite b quark mass corrections from superpartners must be non-zero, but much smaller than naively would be expected. We show that a solution that does not require cancellations of dangerously large tanβ effects in observables implies that scalar superpartner masses should be substantially heavier than the Z scale, and perhaps inaccessible to all currently approved colliders. On the other hand, gauginos must be significantly lighter than the scalars. We demonstrate that a spectrum of anomaly-mediated gaugino masses and heavy scalars works well as a theory compatible with third family Yukawa unification and dark matter observations

Gauge Coupling Unification with Partly Composite Matter

International Nuclear Information System (INIS)

Gherghetta, Tony

2005-01-01

It is shown how gauge coupling unification can occur in models with partly composite matter. The particle states which are composite only contribute small logarithmns to the running of gauge couplings, while the elementary states contribute the usual large logarithmns. This introduces a new differential running contribution to the gauge couplings from partly composite SU(5) matter multiplets. In particular, for partly supersymmetric models, the incomplete SU(5) elementary matter multiplets restore gauge coupling unification even though the usual elementary gaugino and Higgsino contributions need not be present

Confronting the conventional ideas of grand unification with fermion masses, neutrino oscillations and proton decay

Energy Technology Data Exchange (ETDEWEB)

Pati, J C [Department of Physics, University of Maryland, College Park (United States) and Stanford Linear Accelerator Center, Menlo Park (United States)

2002-09-15

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) meeting of the three gauge couplings, (iv) neutrino oscillations; in particular the mass squared-difference {delta}m{sup 2}({nu}{sub {mu}} - {nu}{sub {tau}}) (suggested by SuperK), (v) the intricate pattern of the masses and mixings of the fermions, including the smallness of V{sub cb} and the largeness of {theta}{sub {nu}{sub {mu}{nu}}{sub {tau}}}{sup osc}, 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 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, including the superheavy Majorana masses of the right-handed neutrinos, 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) x 10{sup 34} years, with {nu}-barK{sup +} being the dominant decay mode, and quite possibly {mu}{sup p}+K{sup 0} and e

Confronting the conventional ideas of grand unification with fermion masses, neutrino oscillations and proton decay

International Nuclear Information System (INIS)

Pati, J.C.

2002-01-01

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) meeting of the three gauge couplings, (iv) neutrino oscillations; in particular the mass squared-difference Δm 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 ν μ ν τ osc , 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 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, including the superheavy Majorana masses of the right-handed neutrinos, 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) x 10 34 years, with ν-barK + being the dominant decay mode, and quite possibly μ p +K 0 and e + π 0 being prominent. This in turn strongly suggests that an improvement in the current

String derived exophobic SU(6)×SU(2) GUTs

International Nuclear Information System (INIS)

Bernard, Laura; Faraggi, Alon E.; Glasser, Ivan; Rizos, John; Sonmez, Hasan

2013-01-01

With the apparent discovery of the Higgs boson, the Standard Model has been confirmed as the theory accounting for all sub-atomic phenomena. This observation lends further credence to the perturbative unification in Grand Unified Theories (GUTs) and string theories. The free fermionic formalism yielded fertile ground for the construction of quasi-realistic heterotic-string models, which correspond to toroidal Z 2 ×Z 2 orbifold compactifications. In this paper we study a new class of heterotic-string models in which the GUT group is SU(6)×SU(2) at the string level. We use our recently developed fishing algorithm to extract an example of a three generation SU(6)×SU(2) GUT model. We explore the phenomenology of the model and show that it contains the required symmetry breaking Higgs representations. We show that the model admits flat directions that produce a Yukawa coupling for a single family. The novel feature of the SU(6)×SU(2) string GUT models is that they produce an additional family universal anomaly free U(1) symmetry, and may remain unbroken below the string scale. The massless spectrum of the model is free of exotic states.

Restrictions on SU(5) as a grand unified theory

International Nuclear Information System (INIS)

Shellard, R.C.

1984-01-01

Some restrictions imposed upon Grand Unified Theories by dynamical symetry breakdown are examined. They are shown that, in particular, theories SU(5) as symmetry group, with 3 or more fermion families undergo dynamical symmetry breakdown, and some of the fermions will acquire mass at the Grand Unified scale. On the other hand, the SO(10) group, with 3 families is free from this problem. (Author) [pt

On grand unified SU(8)sub(L)xSU(8)sub(R) model

International Nuclear Information System (INIS)

Pirogov, Yu.F.

1980-01-01

A set of general prjnciples justifying the choice of the group SU(N)sub(L)xSU(N)sub(R) with N=8 as the grand unified symmetry group is considered. Accordjng to these principles the group SU(N)sub(L)xSU(N)sub(R) is one of the most natural unified groups. Namely this group is maximum symmetry group of kinetic term of the Lagrangian of one family, which conserves fermion number. A new principle has been introduced according to which one of the manifestations of extended conformal invariance at small distances is mirror doubling of set of fermions, which is necessary on the other hand for renormalizability of the given unified model

Grand unification in higher dimensions with split supersymmetry

International Nuclear Information System (INIS)

Schuster, Philip C.

2006-01-01

We investigate gauge coupling unification in higher dimensional GUT models with split supersymmetry. We focus on 5d and 6d orbifold GUTs, which permit a simple solution to several problems of 4D GUTs as well as control over GUT scale threshold corrections. In orbifold GUTs, calculable threshold corrections can raise or lower the prediction for α s (M Z ) in a way that depends on the location of Higgs fields. On the other hand, split supersymmetry lowers the prediction for α s (M Z ). Consequently, split supersymmetry changes the preferred location of the Higgs fields in orbifold GUTs. In the simplest models, we find that gauge coupling unification favors higgs doublets that live on the orbifold fixed points instead of in the bulk. In addition, relatively high scales of supersymmetry breaking of 10 10±2 GeV are generically favored

Aspects of the flipped unification of strong, weak and electromagnetic interactions

Energy Technology Data Exchange (ETDEWEB)

Ellis, J.; Hagelin, J.S.; Kelley, S.; Nanopoulos, D.V.

1988-12-19

We explore phenomenological aspects of a recently proposed flipped SU(5) x U(1) supersymmetric GUT which incorporates an economical and natural mechanism for splitting Higgs doublets and triplets, and can be derived from string theory. Using experimental values of sin/sup 2/theta/sub W/ and the strong QCD coupling, we estimate the grand unification scale M/sub G/, where the strong and weak coupling strengths are equal, and the superunification scale M/sub SU/, where all couplings are equal. We find typical values of M/sub G/ approx. = 10/sup 15/ to 10/sup 17/ GeV, with M/sub SU/ somewhat higher and close to the value suggested by string models. We discuss different mechanisms for baryon decay, finding that the dominant one is gauge-boson exchange giving rise to p -> e/sup +/ /sup 0/, anti /sup +/ and n -> e/sup +/ /sup -/, anti /sup 0/ with partial lifetimes approx. = 10/sup 35+-2/ y. We show that a large GUT symmetry-breaking scale M/sub G/ is naturally generated by radiative corrections to the effective potential if a small amount approx. = m/sub W/ of soft supersymmetry breaking is generated dynamically at a large scale. We analyze the low-energy effective theory obtained using the renormalization group equations, demonstrating that electroweak symmetry breaking is obtained if m/sub t/ approx. = 60 to 90 GeV. We analyze the spectrum of sparticles, with particular attention to neutralinos.

New grand unified models with intersecting D6-branes, neutrino masses, and flipped SU(5)

Energy Technology Data Exchange (ETDEWEB)

Cvetic, Mirjam [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104-6396 (United States)]. E-mail: cvetic@cvetic.hep.upenn.edu; Langacker, Paul [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104-6396 (United States); School of Natural Sciences, Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)

2007-07-30

We construct new supersymmetric SU(5) grand unified models based on Z{sub 4}xZ{sub 2} orientifolds with intersecting D6-branes. Unlike constructions based on Z{sub 2}xZ{sub 2} orientifolds, the orbifold images of the three-cycles wrapped by D6-branes correspond to new configurations and thus allow for models in which, in addition to the chiral sector in 10 and 5-bar representations of SU(5), only, there can be new sectors with (15+15-bar) and (10+10-bar) vector-pairs. We construct an example of such a globally consistent, supersymmetric model with four-families, two Standard Model Higgs pair-candidates and the gauge symmetry U(5)xU(1)xSp(4). In an N=2 sector, there are 5x(15+15-bar) and 1x(10+10-bar) vector-pairs, while another N=1 sector contains one vector-pair of 15-plets. The N=2 vector-pairs can obtain a large mass dynamically by parallel D6-brane splitting in a particular two-torus. The 15-vector-pairs provide, after symmetry breaking to the Standard Model (via parallel D-brane splitting), triplet pair candidates which can in principle play a role in generating Majorana-type masses for left-handed neutrinos, though the necessary Yukawa couplings are absent in the specific construction. This model can also be interpreted as a flipped SU(5)xU(1){sub X} grand unified model where the 10-vector-pairs can play the role of Higgs fields, though again there are phenomenological difficulties for the specific construction.

SO(10) - Grand unification and fermion masses

International Nuclear Information System (INIS)

Oezer, A.D.

2005-01-01

In this work, we study SO(10) grand unification in its full extent by using different explicit matrix representations which exhibit the structure of SO(10) in a very transparent way. Our approach consists mainly of two stages: We derive the explicit expressions of the mass-eigenvalues and mass-eigenstates of the physical gauge bosons from a mass squared-matrix that contains all the information about the mixing parameters among the gauge fields and the phases which are sources for CP violation. In the light of this analysis, we derive the explicit expressions for the interaction Lagrangians of the charged currents, the neutral currents and the charged and colored currents in SO(10). We present explicit expressions of the vector and axial-vector couplings of the two neutral currents in SO(10). We show how the baryon, lepton and baryon minus lepton number violating processes and their explicit CP violating phases are accommodated in the SO(10) theory. The Higgs potential that we use to implement in the Higgs mechanism is constructed in a most general fashion through a careful study of the Higgs fields of SO(10), where we give special emphasis on illustrating the explicit matrix representation of these Higgs fields. The potential part of the Higgs Lagrangian will give us the properties of the minimum of the vacuum, and the kinetic part will give us the mass-squared matrix of the gauge bosons via spontaneous symmetry breakdown. The same Higgs multiplets will be coupled to fermions through a democratic Yukawa matrix. Thereby, we derive explicit expressions for the fermion masses of the third family including Majorana and Dirac masses for neutrinos. We introduce a flavor-eigenbasis for neutrinos and find the mass-eigenstates and mass-eigenvalues of the neutrinos. Explicit expressions for CP violation in the neutrino sector are obtained. In the second stage of our work, we evaluate all the above mentioned quantities. In addition, we present the values of the physical

Asymptotically safe grand unification

Energy Technology Data Exchange (ETDEWEB)

Bajc, Borut [J. Stefan Institute,1000 Ljubljana (Slovenia); Sannino, Francesco [CP-Origins & the Danish IAS, University of Southern Denmark,Campusvej 55, DK-5230 Odense M (Denmark); Université de Lyon, France, Université Lyon 1, CNRS/IN2P3, UMR5822 IPNL,F-69622 Villeurbanne Cedex (France)

2016-12-28

Phenomenologically appealing supersymmetric grand unified theories have large gauge representations and thus are not asymptotically free. Their ultraviolet validity is limited by the appearance of a Landau pole well before the Planck scale. One could hope that these theories save themselves, before the inclusion of gravity, by generating an interacting ultraviolet fixed point, similar to the one recently discovered in non-supersymmetric gauge-Yukawa theories. Employing a-maximization, a-theorem, unitarity bounds, as well as positivity of other central charges we nonperturbatively rule out this possibility for a broad class of prime candidates of phenomenologically relevant supersymmetric grand unified theories. We also uncover candidates passing these tests, which have either exotic matter or contain one field decoupled from the superpotential. The latter class of theories contains a model with the minimal matter content required by phenomenology.

Low mass-scale parity restoration in expanded gauge theories

International Nuclear Information System (INIS)

Rajpoot, S.

1982-07-01

It is shown that schemes of grand unification with SU(2n) 4 gauge symmetry permit the embedding of the left-right symmetric SU(2)sub(L)xSU(2)sub(R)xU(1)xSU(3) intermediate symmetry at relatively low energies (between 250 GeV and 1 TeV) as well as allowing light unification mass-scales ( 5 TeV) if n>=3 for values of the weak angle Sin 2 thetasub(W) and the strong coupling αsub(s) in the ranges 0.20 2 thetasub(W)<=0.25, 0.10<=αsub(s)<=0.15. (author)

Masses and mixing angles in SU(5) gauge model

International Nuclear Information System (INIS)

Nandi, S.; Tanaka, K.

1979-01-01

Georgi and Jarlskog mass relations m/sub μ/m/sub e/ = 9m/sub s//m/sub d/, m/sub b/ = m/sub tau/ are obtained above the grand unification mass M = 10 15 GeV with two approx. 5's and one approx. 45 Higgs representations of SU(5) and a discrete symmetry. In the lowest order, the Kobayashi-Maskawa angles are found to be s 2 = -(m/sub c//m/sub t/) /sup 1/2/ and s 3 = -(m/sub u//m/sub t/) /sup 1/2//s 1 , where s 1 is the sine of the Cabibbo angle. The CP violation is considered, and the b quark decays predominantly into c quarks with lifetime of tau/sub b/ approx. equal to 10 -13 s for m/sub t/ = 25 GeV

Elementary particles and physics interaction unification

International Nuclear Information System (INIS)

Leite-Lopes, J.

1985-01-01

Quantum theory and relativity theory are fundamental of relativistic quantum mechanics, quantum field theory, which is the base of elementary particle physics, gauge field theory and basic force unification models. After a short introduction of relativistic equations of the main fields, the free scalar field, the free vector field, the free electromagnetic field and the free spinor field, and of elementary particles and basic interactions, gauge invariance and electromagnetic gauge field are detailed. Then the presentation of internal degrees of freedom, especially isospin, introduces gauge field theory of Yang-Mills. At last weak interactions and strong interactions are presented and lead to grand unification theory in conclusion [fr

Flavour Democracy in Strong Unification

CERN Document Server

Abel, S A; Abel, Steven; King, Steven

1998-01-01

We show that the fermion mass spectrum may naturally be understood in terms of flavour democratic fixed points in supersymmetric theories which have a large domain of attraction in the presence of "strong unification". Our approach provides an alternative to the approximate Yukawa texture zeroes of the Froggatt-Nielsen mechanism. We discuss a particular model based on a broken gauged $SU(3)_L\\times SU(3)_R$ family symmetry which illustrates our approach.

Twenty years later: Why I still believe in SU(4)-color

International Nuclear Information System (INIS)

Pati, J.C.

1994-01-01

Following some preliminary remarks of a historical nature, the recent success of the conventional approach to grand unification as regards the meeting of the coupling constants is summarized. Its shortcomings as regards the arbitrariness in the Higgs sector are noted and a case is made for an alternative approach to unification based on a purely gauge origin of the fundamental forces. This seems to call for the ideas of local supersymmetry and preons. Preonic ideas in turn seem to require SU(4)-color symmetry. The advantages of the marriage of these ideas as regards an understanding of the origins of (a) diverse mass-scales, (b) family-replication and (c) inter-family mass-hierarchy are discussed. (author). 31 refs, 2 figs

Unification and supersymmetry

International Nuclear Information System (INIS)

Mohapatra, R.N.

1991-01-01

This book deals with some of the latest developments in our attempts to construct a unified theory of the fundamental interactions of nature. Among the topics covered are spontaneous symmetry breaking, grand unified theories, supersymmetry, and supergravity. The book starts with a quick review of elementary particle theory and continues with a discussion of composite quarks, leptons, Higgs bosons, and CP violation; it concludes with consideration of supersymmetric unification schemes, in which bosons and leptons are considered in some sense equivalent. The second edition is updated and corrected and contains new chapters on recent developments

Particle physics models of inflation in supergravity and grand unification

International Nuclear Information System (INIS)

Kostka, Philipp Manuel

2010-01-01

magnetic monopoles at the end of the stage of inflation can be avoided. Finally, we sketch how in tribrid inflation models the concepts discussed in the two parts can be combined to realize inflation via Heisenberg symmetry in local supersymmetric SO(10) grand unification. (orig.)

Particle physics models of inflation in supergravity and grand unification

Energy Technology Data Exchange (ETDEWEB)

Kostka, Philipp Manuel

2010-12-03

production of stable magnetic monopoles at the end of the stage of inflation can be avoided. Finally, we sketch how in tribrid inflation models the concepts discussed in the two parts can be combined to realize inflation via Heisenberg symmetry in local supersymmetric SO(10) grand unification. (orig.)

Domain walls and fermion scattering in grand unified models

International Nuclear Information System (INIS)

Steer, D.A.; Vachaspati, T.

2006-01-01

Motivated by grand unification, we study the properties of domain walls formed in a model with SU(5)xZ 2 symmetry which is spontaneously broken to SU(3)xSU(2)xU(1)/Z 6 , and subsequently to SU(3)xU(1)/Z 3 . Even after the first stage of symmetry breaking, the SU(3) symmetry is broken to SU(2)xU(1)/Z 2 on the domain wall. In a certain range of parameters, flux tubes carrying color- and hyper-charge live on the domain wall and appear as 'boojums' when viewed from one side of the domain wall. Magnetic monopoles are also formed in the symmetry breaking and those carrying color and hyper-charge can be repelled from the wall due to the Meissner effect, or else their magnetic flux can penetrate the domain wall in quantized units. After the second stage of symmetry breaking, fermions can transmute when they scatter with the domain wall, providing a simpler version of fermion-monopole scattering: for example, neutrinos can scatter into d-quarks, leaving behind electric charge and color which is carried by gauge field excitations living on the domain wall

Low energy implications of minimal superstring unification

International Nuclear Information System (INIS)

Khalil, S.; Vissani, F.; Masiero, A.

1995-11-01

We study the phenomenological implications of effective supergravities based on string vacua with spontaneously broken N =1 supersymmetry by dilation and moduli F-terms. We further require Minimal String Unification, namely that large string threshold corrections ensure the correct unification of the gauge couplings at the grand unification scale. The whole supersymmetric mass spectrum turns out to be determined in terms of only two independent parameters, the dilaton-moduli mixing angle and the gravitino mass. In particular we discuss the region of the parameter space where at least one superpartner is ''visible'' at LEPII. We find that the most likely candidates are the scalar partner of the right-handed electron and the lightest chargino, with interesting correlations between their masses and with the mass of the lightest higgs. We show how discovering SUSY particles at LEPII might rather sharply discriminate between scenarios with pure dilaton SUSY breaking and mixed dilaton-moduli breaking. (author). 10 refs, 7 figs

Minimal SUSY SO(10) and Yukawa unification

International Nuclear Information System (INIS)

Okada, Nobuchika

2013-01-01

The minimal supersymmetric (SUSY) SO(10) model, where only two Higgs multiplets {10⊕126-bar} are utilized for Yukawa couplings with matter fields, can nicely fit the neutrino oscillation parameters as well as charged fermion masses and mixing angles. In the fitting of the fermion mass matrix data, the largest element in the Yukawa coupling with the 126-bar -plet Higgs (Y 126 ) is found to be of order one, so that the right see-saw scale should be provided by Higgs vacuum expectation values (VEVs) of β(10 14 GeV). This fact causes a serious problem, namely, the gauge coupling unification is spoiled because of the presence of many exotic Higgs multiples emerging at the see-saw scale. In order to solve this problem, we consider a unification between bottom-quark and tau Yukawa couplings (b - τ Yukawa coupling unification) at the grand unified theory (GUT) scale, due to threshold corrections of superpartners to the Yukawa couplings at the 1 TeV scale. When the b - τ Yukawa coupling unification is very accurate, the largest element in Y 126 can become β(0.01), so that the right see-saw scale is realized by the GUT scale VEV and the usual gauge coupling unification is maintained. Since the b - τ Yukawa unification alters the Yukawa coupling data at the GUT scale, we re-analyze the fitting of the fermion mass matrix data by taking all the relevant free parameters into account. Unfortunately, we find that no parameter region shows up to give a nice fit for the current neutrino oscillation data and therefore, the usual picture of the gauge coupling unification cannot accommodate the fermion mass matrix data fitting in our procedure.

Signatures of flipped SU(5)

Energy Technology Data Exchange (ETDEWEB)

Abel, S.A. (Bristol Univ. (UK). H.H. Wills Physics Lab.); Whittingham, I. (James Cook Univ. of North Queensland, Townsville (Australia). Dept. of Physics)

1990-02-22

We examine the electric dipole moment of the neutron and flavour changing Z decays in the flipped SU(5) grand unification scheme. We find that the new couplings at energy scales above M{sub GUT} can lead to neutron electric dipole moments vertical strokedvertical stroke{approx equal} 10{sup -25} e cm and decays of the form Z{yields}banti s, santi b with a branching ratio Bsub(Z{yields}banti s,santi b) {approx equal} 10{sup -6}, of which a large proportion ({epsilon}{le}1/4) may be CP violating. The first two effects are found to be slightly suppressed in the currently popular no-scale theories, but the CP violation parameter, {epsilon}, is relatively theory independent. (orig.).

Grand unification and subcritical hybrid inflation

International Nuclear Information System (INIS)

Buchmueller, Wilfried; Ishiwata, Koji

2014-12-01

We consider hybrid inflation for small couplings of the inflaton to matter such that the critical value of the inflaton field exceeds the Planck mass. It has recently been shown that inflation then continues at subcritical inflaton field values where quantum fluctuations generate an effective inflaton mass. The effective inflaton potential interpolates between a quadratic potential at small field values and a plateau at large field values. An analysis of the allowed parameter space leads to predictions for the scalar spectral index n s and the tensor-to-scalar ratio r similar to those of natural inflation. Using the range for n s and r favoured by the Planck data, we find that the energy scale of the plateau is constrained to the interval (1.6-2.4) x 10 16 GeV which includes the energy scale of gauge coupling unification in the supersymmetric standard model. The tensor-to-scalar ratio is predicted to have the lower bound r>0.049 for 60 e-folds before the end of inflation.

Gauge coupling running in minimal SU(3) x SU(2) x U(1) superstring unification

CERN Document Server

Ibáñez, L E; Ross, Graham G

1991-01-01

We study the evolution of the gauge coupling constants in string unification schemes in which the light spectrum below the compactification scale is exactly that of the minimal supersymmetric standard model. In the absence of string threshold corrections the predicted values $\\sin^2\\theta _W=0.218$ and $\\alpha _s=0.20$ are in gross conflict with experiment, but these corrections are generically important. One can express the string threshold corrections to $\\sin^2\\theta _W$ and $\\alpha_s$ in terms of certain $modular$ $weights$ of quark, lepton and Higgs superfields as well as the $moduli$ of the string model. We find that in order to get agreement with the experimental measurements within the context of this $minimal$ scheme, certain constraints on the $modular$ $weights$ of the quark, lepton and Higgs superfields should be obeyed. Our analysis indicates that this $minimal$ $string$ $unification$

Dark matter, mirror world, and E6 unification

International Nuclear Information System (INIS)

Das, Ch. R.; Laperashvili, L. V.

2009-01-01

The idea that the ordinary (O) and mirror (M) worlds exist simultaneously is developed. It is shown that, in the case of a violated mirror parity (MP), the renormalization-group evolution of the coupling constants, which is represented in the O world by the dependence α i -1 (μ) (μ is an energy variable), is not identical to the evolution of the coupling constants α' i -1 (μ) in the M world. Here, the index i labels the symmetry group under consideration, while a dash labels quantities defined in the M world. It is assumed that E 6 unification predicted by superstring theory restores MP at the unification scale M SGUT ∼ 10 18 GeV, this inevitably leading to the difference in the violation of E 6 unification in the O and M worlds at lower energies: E 6 → SO(10) x U(1) Z and E' 6 → SU(6)' x SU(2)' Z . Considering only asymptotically free theories, we present the evolution of all the inverse coupling constants α i -1 (μ) in the one-loop approximation. In dealing with the M world involving MP violation, we then arrive at the model of the accelerating expansion of our Universe, where the axion ('acceleron') belongs to the SU(2)' Z group of the M world. The coupling constant g' Z , which grows indefinitely at the scale Λ' Z ∼ 10 -3 eV, is associated with this group. Within this theory, our Universe is in the false vacuum of the M world, in agreement with the phenomenologically observed cosmological constant of about (3 x 10 -3 eV) 4 .

Unification of gauge couplings in radiative neutrino mass models

DEFF Research Database (Denmark)

Hagedorn, Claudia; Ohlsson, Tommy; Riad, Stella

2016-01-01

masses at one-loop level and (III) models with particles in the adjoint representation of SU(3). In class (I), gauge couplings unify in a few models and adding dark matter amplifies the chances for unification. In class (II), about a quarter of the models admits gauge coupling unification. In class (III......We investigate the possibility of gauge coupling unification in various radiative neutrino mass models, which generate neutrino masses at one- and/or two-loop level. Renormalization group running of gauge couplings is performed analytically and numerically at one- and two-loop order, respectively....... We study three representative classes of radiative neutrino mass models: (I) minimal ultraviolet completions of the dimension-7 ΔL = 2 operators which generate neutrino masses at one- and/or two-loop level without and with dark matter candidates, (II) models with dark matter which lead to neutrino...

Renormalization effects in the SU(16) maximally gauged theory

International Nuclear Information System (INIS)

Mahdavi-Hezaveh, E.

1981-03-01

In the context of a quark-lepton unified gauge theory, when fermionic degrees of freedom are maximally gauged, several intermediate mass scales filling the grand plateau, between 10 2 Gev. and the grand unifying mass scale, M, may exist. In particular, when renormalization effects are taken into account for the SU(16) ''maximal'' gauge symmetry, [in which lepton number is regarded as the fourth color quantum number], it turns out that two intermediate stages governed by the symmetries G 2 =SU(8)sub(I) S SU(8)sub(II) X U(1)sub(F) and G 3 =SU(2)sub(L) X XU(2)sub(R) X SU(4)sub(C) can naturally coexist if Sin 2 theta (Msub(W))>1/6+5/9(α(Msub(W)/αsub(S)(Msub(W)). It is shown that these symmetries break down at a mass scale of the order of Msub(X) approximately equal to 10 4 -10 5 Gev. If neutral current phenomenology (or any other experiment) predicts Sin 2 theta (Msub(W))>0.206, then quark-lepton unification and left-right symmetry simultaneously break down at M approximately equal to 10 4 Gev. (at which αsub(C)(Msub(X) approximately equal to 0.041). It is then argued that apart from proton decay, n-anti n oscillation and neutrinoless double β decay processes, an accurate experimental value of Sin 2 theta (Msub(W)), to α 10 -4 accuracy) plays a crucial role in determining the possible existence of such intermediate stages. (author)

Light grand unified theory triplets and Yukawa splitting

International Nuclear Information System (INIS)

Rakshit, Subhendu; Shadmi, Yael; Raz, Guy; Roy, Sourov

2004-01-01

Triplet-mediated proton decay in grand unified theories (GUTs) is usually suppressed by arranging a large triplet mass. Here we explore instead a mechanism for suppressing the couplings of the triplets to the first and second generations compared to the Yukawa couplings, so that the triplets can be light. This mechanism is based on a 'triplet symmetry' in the context of product-group GUTs. We study two possibilities. The first possibility, which requires the top Yukawa coupling to arise from a nonrenormalizable operator at the GUT scale, is that all triplet couplings to matter are negligible, so that the triplets can be at the weak scale, giving new evidence for grand unification. The second possibility is that some triplet couplings, and in particular Ttb and Tt-barl-bar, are equal to the corresponding Yukawa couplings. This would give a distinct signature of grand unification if the triplets were sufficiently light. However, we derive a model-independent bound on the triplet mass in this case, which is at least 10 6 GeV. Finally, we construct an explicit viable GUT model based on Yukawa splitting, with the triplets at 10 14 GeV, as required for coupling unification to work. This model requires no additional thresholds below the GUT scale

SO(14) unification of 3+1 families

International Nuclear Information System (INIS)

Karadayi, H.R.

1982-03-01

It is shown that the unification of 3+1 families is possible within the framework of 64 dimensional spinor representation of SO(14). Special care is given for a description without the heavy excess fermions such as conjugate and mirror or completely exotic fermions of some family unification schemes. With the aid of an intrinsic ''L-R Asymmetry'' mechanism which we proposed recently, the conventional strong and electromagnetic interactions are obtained for all four families by concentrating only on the symmetry breaking SO(14) → SU(3)sub(c) x U(1)sub(e.m.). However, the conventional weak interactions of the first three families are obtained just as in the standard SU(2)sub(L) x U(1)sub(Y) model, while those of the prescribed fourth family show certain differences. This is what we mean by 3+1 family unification. All vector particles mediating strong, electromagnetic and weak interactions which are the subjects of present phenomenological tests are specified among the vector fields of SO(14) and their mass mechanisms leading to a consistent description of this low-energy phenomenology are studied with the aid of the Higgs multiplets 14, 364, 1716 and 2002 of SO(14). Moreover, the fermion mass mechanisms are considered with the aid of these scalar multiplets and the contributions from these scalars to the vector and fermion masses are explicitly calculated. All these calculations are carried out in the new mathematical technique for the Lie algebra representations which we introduced recently. (author)

Probes of Yukawa unification in supersymmetric SO(10) models

Energy Technology Data Exchange (ETDEWEB)

Westhoff, Susanne

2009-10-23

This work is composed as follows: In Chapter 1, the disposed reader is made familiar with the foundations of flavourphysics and Grand Unification, including group-theoretical aspects of SO(10). In Chapter 2, we introduce a specific supersymmetric GUT model based on SO(10) and designed to probe down-quark-lepton Yukawa unification. Within this framework we explore the effects of large atmospheric neutrino mixing in bottom-strange transitions on the mass difference and CP phase in B{sub s}- anti B{sub s} meson mixing. Chapter 3 is devoted to corrections to Yukawa unification. We derive constraints on Yukawa corrections for light fermions from K- anti K and B{sub d}- anti B {sub d} mixing. As an application we study implications of neutrino mixing effects in CP-violating K and B{sub d} observables on the unitrity triangle. Finally, in Chapter 4, we discuss effects of large tan {beta} in B{yields}(D){tau}{nu} decays with respect to their potential to discover charged Higgs bosons and to discriminate between different GUT models of flavour.

SO(10) supersymmetric grand unified theories

Science.gov (United States)

Dermisek, Radovan

The origin of the fermion mass hierarchy is one of the most challenging problems in elementary particle physics. In the standard model fermion masses and mixing angles are free parameters. Supersymmetric grand unified theories provide a beautiful framework for physics beyond the standard model. In addition to gauge coupling unification these theories provide relations between quark and lepton masses within families, and with additional family symmetry the hierarchy between families can be generated. We present a predictive SO(10) supersymmetric grand unified model with D 3 x U(1) family symmetry. The hierarchy in fermion masses is generated by the family symmetry breaking D 3 x U(1) → ZN → nothing. This model fits the low energy data in the charged fermion sector quite well. We discuss the prediction of this model for the proton lifetime in light of recent SuperKamiokande results and present a clear picture of the allowed spectra of supersymmetric particles. Finally, the detailed discussion of the Yukawa coupling unification of the third generation particles is provided. We find a narrow region is consistent with t, b, tau Yukawa unification for mu > 0 (suggested by b → sgamma and the anomalous magnetic moment of the muon) with A0 ˜ -1.9m16, m10 ˜ 1.4m16, m16 ≳ 1200 GeV and mu, M1/2 ˜ 100--500 GeV. Demanding Yukawa unification thus makes definite predictions for Higgs and sparticle masses.

Some consequences of embedding heavy color in grand unified theories

International Nuclear Information System (INIS)

Elias, V.

1980-01-01

I show that ''standard'' embedding constraints cannot accommodate an empirically motivated value for the heavy-color (HC) momentum scale Λ/sub HC/ if the heavy-color group is SU(N>3). The heavy-color group can be SU(3), provided such constraints are relaxed in order to allow fermions to contribute differentially to SU(3)/sub HC/ and SU(3)/sub QCD/ β-functions (QCD=quantum chromodynamics). Theories successfully embedding G/sub HC/>SU(3) along with the known interactions are shown to require vastly reduced unification mass scales. As an example, empirically acceptable values for Λ/sub HC/, sin 2 theta/sub W/, and α/sub s/(m/sub W/) as well as a unification mass scale within an order of magnitude of Λ/sub HC/ are accommodated within very large models based on [SU(2n)] 4 unifying symmetry

Infrared fixed point solution for the top quark mass and unification of couplings in the MSSM

International Nuclear Information System (INIS)

Bardeen, W.A.; Carena, M.; Pokorski, S.; Wagner, C.E.M.

1993-08-01

We analyze the implications of the infrared quasi fixed point solution for the top quark mass in the Minimal Supersymmetric Standard Model. This solution could explain in a natural way the relatively large value of the top quark mass and, if confirmed experimentally, may be suggestive of the onset of nonperturbative physics at very high energy scales. In the framework of grand unification, the expected bottom quark -- tau lepton Yukawa coupling unification is very sensitive to the fixed point structure of the top quark mass. For the presently allowed values of the electroweak parameters and the bottom quark mass, the Yukawa coupling unification implies that the top quark mass must be within ten percent of its fixed point values

SU(2) x U(1) x U'(1) models which are slightly different from the Weinberg-Salam model

International Nuclear Information System (INIS)

Gao, C.; Wu, D.

1981-01-01

We discuss SU(2) x U(1) x U'(1) models by a uniform formula which is convenient for their comparison with the standard Weinberg-Salam model. As examples, we give three interesting models which are based on different grand unification models. In one model, U'(1) does not contribute to the electromagnetic interaction; in the other two, both U(1) and U'(1) do contribute to the electromagnetic interaction. Also, the first two models can approach the standard Weinberg-Salam model as close as one wants; but the third model has limitations on it

Gauge coupling unification and nonequilibrium thermal dark matter.

Science.gov (United States)

Mambrini, Yann; Olive, Keith A; Quevillon, Jérémie; Zaldívar, Bryan

2013-06-14

We study a new mechanism for the production of dark matter in the Universe which does not rely on thermal equilibrium. Dark matter is populated from the thermal bath subsequent to inflationary reheating via a massive mediator whose mass is above the reheating scale T(RH). To this end, we consider models with an extra U(1) gauge symmetry broken at some intermediate scale (M(int) ≃ 10(10)-10(12) GeV). We show that not only does the model allow for gauge coupling unification (at a higher scale associated with grand unification) but it can provide a dark matter candidate which is a standard model singlet but charged under the extra U(1). The intermediate scale gauge boson(s) which are predicted in several E6/SO(10) constructions can be a natural mediator between dark matter and the thermal bath. We show that the dark matter abundance, while never having achieved thermal equilibrium, is fixed shortly after the reheating epoch by the relation T(RH)(3)/M(int)(4). As a consequence, we show that the unification of gauge couplings which determines M(int) also fixes the reheating temperature, which can be as high as T(RH) ≃ 10(11) GeV.

Dark Matter after LHC Run I: Clues to Unification

Directory of Open Access Journals (Sweden)

Olive Keith A.

2017-01-01

Full Text Available After the results of Run I, can we still ‘guarantee’ the discovery of supersymmetry at the LHC? It is shown that viable dark matter models in CMSSM-like models tend to lie in strips (co-annihilation, funnel, focus point. The role of grand unification in constructing supersymmetric models is discussed and it is argued that non-supersymmetric GUTs such as SO(10 may provide solutions to many of the standard problems addressed by supersymmetry.

Natural fermion mass hierarchy and mixings in family unification

International Nuclear Information System (INIS)

Dent, James B.; Feger, Robert; Kephart, Thomas W.; Nandi, S.

2011-01-01

We present an SU(9) model of family unification with three light chiral families, and a natural hierarchy of charged fermion masses and mixings. The existence of singlet right handed neutrinos with masses about two orders of magnitude smaller than the GUT scale, as needed to understand the light neutrinos masses via the see-saw mechanism, is compelling in our model.

Gauge unification in highly anisotropic string compactifications

International Nuclear Information System (INIS)

Hebecker, A.; Trapletti, M.

2005-01-01

It is well known that heterotic string compactifications have, in spite of their conceptual simplicity and aesthetic appeal, a serious problem with precision gauge coupling unification in the perturbative regime of string theory. Using both a duality-based and a field-theoretic definition of the boundary of the perturbative regime, we reevaluate the situation in a quantitative manner. We conclude that the simplest and most promising situations are those where some of the compactification radii are exceptionally large, corresponding to highly anisotropic orbifold models. Thus, one is led to consider constructions which are known to the effective field-theorist as higher-dimensional or orbifold grand unified theories (orbifold GUTs). In particular, if the discrete symmetry used to break the GUT group acts freely, a non-local breaking in the larger compact dimensions can be realized, leading to a precise gauge coupling unification as expected on the basis of the MSSM particle spectrum. Furthermore, a somewhat more model dependent but nevertheless very promising scenario arises if the GUT breaking is restricted to certain singular points within the manifold spanned by the larger compactification radii

New Developments in Supersymmetry (2/5)

CERN Multimedia

CERN. Geneva

2001-01-01

Introduction to supersymmetric grand unified theories. An introduction to the MSSM and different mechanisms for supersymmetry breaking. Then the details of SU(5) and SO(10) unification, the new gauge sector beyond the standard model, representations of quarks and leptons. Gauge and Yukawa coupling unification and some predictions.

New Developments in Supersymmetry (5/5)

CERN Multimedia

CERN. Geneva

2001-01-01

Introduction to supersymmetric grand unified theories. An introduction to the MSSM and different mechanisms for supersymmetry breaking. Then the details of SU(5) and SO(10) unification, the new gauge sector beyond the standard model, representations of quarks and leptons. Gauge and Yukawa coupling unification and some predictions.

New Developments in Supersymmetry (3/5)

CERN Multimedia

CERN. Geneva

2001-01-01

Introduction to supersymmetric grand unified theories. An introduction to the MSSM and different mechanisms for supersymmetry breaking. Then the details of SU(5) and SO(10) unification, the new gauge sector beyond the standard model, representations of quarks and leptons. Gauge and Yukawa coupling unification and some predictions.

Theory of weak interactions and related topics. Progress report, January 1-December 31, 1981

International Nuclear Information System (INIS)

Marshak, R.E.

1985-08-01

The research program demonstrated that the acceptance of B-L local symmetry as the weak hypercharge, whose spontaneous breakdown was connected to the spontaneous breakdown of parity, predicted a light electron neutrino (Majorana) and a related heavy neutrino. The prediction of neutron oscillations following from the PUT group SU(4)/sub C/ x SU(2)/sub L/ x SU(2)/sub R/ was scrutinized. A relation was derived between the mixing time for free neutron oscillations and the lifetime for nuclear stability with respect to ΔB = 2 transitions, and a study was conducted of the effect of time-varying or spatial-varying magnetic fields on the mixing time of neutron oscillations. Reasons are given for continuing work with the left-right symmetry (LRS) and partial unification theory (PUT) groups to their grand unification realization. It was shown that, without assuming a simple GUT group, that the color group has to be SU(3) and that the only possible GUT groups are SU(5) and SU(10). The gauge boson mass relation was derived for arbitrary Higgs structure associated either with the standard SU(2)/sub L/ x U(1) electroweak group or the LRS group. Also examined was the Pati-Salam type of grand unification. 31 refs

The anomalous U(1)_{anom} symmetry and flavors from an SU(5) × SU(5)' GUT in Z_{12-I} orbifold compactification

Science.gov (United States)

Kim, Jihn E.; Kyae, Bumseok; Nam, Soonkeon

2017-12-01

In string compactifications, frequently the anomalous U(1) gauge symmetry appears which belongs to E_8 × E_8' of the heterotic string. This anomalous U(1) gauge boson obtains mass at the compactification scale (≈ 10^{18 } {GeV}) by absorbing one pseudoscalar (corresponding to the model-independent axion) from the second rank antisymmetric tensor field B_{MN}. Below the compactification scale a global symmetry U(1)_{anom} results whose charge Q_anom is the original gauge U(1) charge. This is the most natural global symmetry, realizing the "invisible" axion. This global symmetry U(1)_{anom} is suitable for a flavor symmetry. In the simplest compactification model with the flipped SU(5) grand unification, all the low energy parameters are calculated in terms of the vacuum expectation values of the standard model singlets.

Flavor hierarchy in SO(10) grand unified theories via 5-dimensional wave-function localization

Science.gov (United States)

Kitano, Ryuichiro; Li, Tianjun

2003-06-01

A mechanism to generate fermion-mass hierarchy in SO(10) grand unified theories is considered. We find that the lopsided family structure, which is suitable to the large angle Mikheyev-Smirnov-Wolfenstein solution to solar neutrino oscillation, is realized without introducing extra matter fields if the hierarchy originates from the wave-function profile in an extra dimension. Unlike the Froggatt-Nielsen mechanism, the SO(10) breaking effect may directly contribute to the source of the hierarchy, i.e., the bulk mass terms. It naturally explains the difference of the hierarchical patterns between the quark and the lepton sectors. We also find the possibility of horizontal unification, in which three generations of matter fields are unified to a 3-dimensional representation of an SU(2) gauge group.

Flavor hierarchy in SO(10) grand unified theories via 5-dimensional wave-function localization

International Nuclear Information System (INIS)

Kitano, Ryuichiro; Li Tianjun

2003-01-01

A mechanism to generate fermion-mass hierarchy in SO(10) grand unified theories is considered. We find that the lopsided family structure, which is suitable to the large angle Mikheyev-Smirnov-Wolfenstein solution to solar neutrino oscillation, is realized without introducing extra matter fields if the hierarchy originates from the wave-function profile in an extra dimension. Unlike the Froggatt-Nielsen mechanism, the SO(10) breaking effect may directly contribute to the source of the hierarchy, i.e., the bulk mass terms. It naturally explains the difference of the hierarchical patterns between the quark and the lepton sectors. We also find the possibility of horizontal unification, in which three generations of matter fields are unified to a 3-dimensional representation of an SU(2) gauge group

Preon Model and Family Replicated E_6 Unification

Directory of Open Access Journals (Sweden)

Larisa V. Laperashvili

2008-02-01

Full Text Available Previously we suggested a new preon model of composite quark-leptons and bosons with the 'flipped' $E_6imes widetilde{E_6}$ gauge symmetry group. We assumed that preons are dyons having both hyper-electric $g$ and hyper-magnetic $ilde g$ charges, and these preons-dyons are confined by hyper-magnetic strings which are an ${f N}=1$ supersymmetric non-Abelian flux tubes created by the condensation of spreons near the Planck scale. In the present paper we show that the existence of the three types of strings with tensions $T_k=k T_0$ $(k = 1,2,3$ producing three (and only three generations of composite quark-leptons, also provides three generations of composite gauge bosons ('hyper-gluons' and, as a consequence, predicts the family replicated $[E_6]^3$ unification at the scale $sim 10^{17}$ GeV. This group of unification has the possibility of breaking to the group of symmetry: $ [SU(3_C]^3imes [SU(2_L]^3imes [U(1_Y]^3 imes [U(1_{(B-L}]^3$ which undergoes the breakdown to the Standard Model at lower energies. Some predictive advantages of the family replicated gauge groups of symmetry are briefly discussed.

Problems in unification and supergravity

International Nuclear Information System (INIS)

Farrar, G.; Henyey, F.

1984-01-01

Problems in unification of the various gauge groups, quantum gravity, supersymmetry and supergravity, compact dimensions of space-time, and conditions at the beginning of the universe are discussed. Separate entries were prepared for the data base for the 15 papers presented

Twin-unified SU(5) × SU( 5)′ GUT and phenomenology

Indian Academy of Sciences (India)

Specific pattern of the GUT symmetry breaking causes new strong dynamics at ... Issues of the gauge coupling unification, generation of the charged fermion and ...... the SU(3)′ strong sector) and EW symmetry breaking, the scenario shares ...

Problems in unification and supergravity

Energy Technology Data Exchange (ETDEWEB)

Farrar, G.; Henyey, F. (eds.)

1984-01-01

Problems in unification of the various gauge groups, quantum gravity, supersymmetry and supergravity, compact dimensions of space-time, and conditions at the beginning of the universe are discussed. Separate entries were prepared for the data base for the 15 papers presented. (WHK)

Prospects for mass unification at low energy scales

International Nuclear Information System (INIS)

Volkas, R.R.

1995-01-01

A simple Pati-Salam SU(4) model with a low symmetry breaking scale of about 1000 TeV is presented. The analysis concentrates on calculating radiative corrections to tree level mass relations for third generation fermions. The tree-level relation m b /m τ = 1 predicted by such models can receive large radiative corrections up to about 50% due to threshold effects at the mass unification scale. These corrections are thus of about the same importance as those that give rise to renormalisation group running. The high figure of 50% can be achieved because l-loop graphs involving the physical charged Higgs boson give corrections to m τ -m b that are proportional to the large top quark mass. These corrections can either increase or decrease m b /m τ depending on the value of an unknown parameter. They can also be made to vanish through a fine-tuning. A related model of tree-level t-b-τ unification which uses the identification of SU(2) R with custodial SU(2) is then discussed. A curious relation m b ∼ √2m τ is found to be satisfied at tree-level in this model. The overall conclusion of this work is that the tree-level relation m b =m τ at low scales such as 1000 TeV or somewhat higher can produce a successful value for m b /m τ after corrections, but one must be mindful that radiative corrections beyond those incorporated through the renormalisation group can be very important. 14 refs., 7 figs

New aspects of flavour model building in supersymmetric grand unification

International Nuclear Information System (INIS)

Spinrath, Martin

2010-01-01

We derive predictions for Yukawa coupling ratios within Grand Unified Theories generated from operators with mass dimension four and five. These relations are a characteristic property of unified flavour models and can reduce the large number of free parameters related to the flavour sector of the Standard Model. The Yukawa couplings of the down-type quarks and charged leptons are affected within supersymmetric models by tan β-enhanced threshold corrections which can be sizeable if tan β is large. In this case their careful inclusion in the renormalisation group evolution is mandatory. We analyse these corrections and give simple analytic expressions and numerical estimates for them. The threshold corrections sensitively depend on the soft supersymmetry breaking parameters. Especially, they determine the overall sign of the corrections and therefore if the affected Yukawa couplings are enhanced or suppressed. In the minimal supersymmetric extension of the Standard Model many free parameters are introduced by supersymmetry breaking about which we make some plausible assumptions in our first simplified approach. In a second, more sophisticated approach we use three common breaking schemes in which all the soft breaking parameters at the electroweak scale can be calculated from only a handful of parameters. Within the second approach, we apply various phenomenological constraints on the supersymmetric parameters and find in this way new viable Yukawa coupling relations, for example y μ /y s =9/2 or 6 or y τ /y b =3/2 in SU(5). Furthermore, we study a special class of quark mass matrix textures for small tan β where θ u 13 =θ d 13 =0. We derive sum rules for the quark mixing parameters and find a simple relation between the two phases δ u 12 and δ d 12 and the right unitarity triangle angle α which suggests a simple phase structure for the quark mass matrices where one matrix element is purely imaginary and the remaining ones are purely real. To complement

SU(5) without SU(5): why B-L is conserved and baryon number not in unified models of quarks and leptons

International Nuclear Information System (INIS)

Lipkin, H.J.

1980-09-01

Quark-lepton unification is examined without assuming higher symmetries on more general gauge theories. In particular, properties are sought which are generally attributed to SU(5) models which are already present without the assumption of SU(5)

Towards a new paradigm for quark-lepton unification

Energy Technology Data Exchange (ETDEWEB)

Smith, Christopher [Laboratoire de Physique Subatomique et de Cosmologie, Université Grenoble-Alpes, CNRS/IN2P3,53 avenue des Martyrs, 38026 Grenoble Cedex (France)

2017-05-03

The quark and charged lepton mass patterns upset their naïve unification. In this paper, a new approach to solve this problem is proposed. Model-independently, we find that a successful unification can be achieved. A mechanism is identified by which the large top quark mass renders its third-generation leptonic partner very light. This state is thus identified with the electron. We then construct a toy model to implement dynamically this mechanism, using tree-level exchanges of vector leptons to relate the quark and charged lepton flavor structures. In a supersymmetric context, this same mechanism splits the squark masses, and third generation squarks end up much lighter than the others. Finally, the implementation of this mechanism in SU(5) GUT permits to avoid introducing any flavor structure beyond the two minimal Yukawa couplings, ensuring the absence of unknown mixing matrices and their potentially large impact on FCNC.

Supersymmetry, supergravity, and unification

CERN Document Server

Nath, Pran

2017-01-01

This unique book gives a modern account of particle physics and gravity based on supersymmetry and supergravity, two of the most significant developments in theoretical physics since general relativity. The book begins with a brief overview of the history of unification and then goes into a detailed exposition of both fundamental and phenomenological topics. The topics in fundamental physics include Einstein gravity, Yang-Mills theory, anomalies, the standard model, supersymmetry and supergravity, and the construction of supergravity couplings with matter and gauge fields, as well as computational techniques for SO(10) couplings. The topics of phenomenological interest include implications of supergravity models at colliders, CP violation, and proton stability, as well as topics in cosmology such as inflation, leptogenesis, baryogenesis, and dark matter. The book is intended for graduate students and researchers seeking to master the techniques for building grand unified models.

Post-sphaleron baryogenesis and n- anti n oscillation in non-SUSY SO(10) GUT with gauge coupling unification

International Nuclear Information System (INIS)

Patra, Sudhanwa; Pritimita, Prativa

2014-01-01

''Post-sphaleron baryogenesis'', a fresh and profound mechanism of baryogenesis accounts for the matter-antimatter asymmetry of our present universe in a framework of Pati-Salam symmetry. We attempt here to embed this mechanism in a non-SUSY SO(10) grand unified theory by reviving a novel symmetry breaking chain with Pati-Salam symmetry as an intermediate symmetry breaking step and as well to address post-sphaleron baryogenesis and neutron-antineutron oscillation in a rational manner. The Pati-Salam symmetry based on the gauge group SU(2) L x SU(2) R x SU(4) C is realized in our model at 10 5 -10 6 GeV and the mixing time for the neutron-antineutron oscillation process having ΔB = 2 is found to be τ n- anti n ≅ 10 8 -10 10 s with the model parameters, which is within the reach of forthcoming experiments. Other novel features of the model include low scale right-handed W R ± , Z R gauge bosons, explanation for neutrino oscillation data via the gauged inverse (or extended) seesaw mechanism and most importantly TeV scale color sextet scalar particles responsible for an observable n- anti n oscillation which may be accessible to LHC. We also look after gauge coupling unification and an estimation of the proton lifetime with and without the addition of color sextet scalars. (orig.)

Focus point gauge mediation in product group unification

International Nuclear Information System (INIS)

Bruemmer, Felix; Ibe, Masahiro; Tokyo Univ., Kashiwa; Yanagida, Tsutomu T.

2013-03-01

In certain models of gauge-mediated supersymmetry breaking with messenger fields in incomplete GUT multiplets, the radiative corrections to the Higgs potential cancel out during renormalization group running. This allows for relatively heavy superpartners and for a 125 GeV Higgs while the ne-tuning remains modest. In this paper, we show that such gauge mediation models with ''focus point'' behaviour can be naturally embedded into a model of SU(5) x U(3) product group unification.

Gauge coupling unification in heterotic string models with gauge mediated supersymmetry breaking

International Nuclear Information System (INIS)

Anandakrishnan, Archana; Raby, Stuart

2011-01-01

We calculate the weak scale minimal supersymmetric standard model spectrum starting from a heterotic string theory compactified on an anisotropic orbifold. Supersymmetry breaking is mediated by vectorlike exotics that arise naturally in heterotic string theories. The messengers that mediate supersymmetry breaking come in incomplete grand unified theory (GUT) multiplets and give rise to nonuniversal gaugino masses at the GUT scale. Models with nonuniversal gaugino masses at the GUT scale have the attractive feature of allowing for precision gauge coupling unification at the GUT scale with negligible contributions from threshold corrections near the unification scale. The unique features of this minimally supersymmetric standard model spectrum are light gluinos and also large mass differences between the lightest and the next-to-lightest neutralinos and charginos which could lead to interesting signatures at the colliders.

Functional Pearls : Polytypic Unification

NARCIS (Netherlands)

Jansson, P.; Jeuring, J.T.

1998-01-01

Unification, or two-way pattern matching, is the process of solving an equation involving two first-order terms with variables. Unification is used in type inference in many programming languages and in the execution of logic programs. This means that unification algorithms have to be written over

Cosmological origin of the grand-unification mass scale

International Nuclear Information System (INIS)

Brout, R.; Englert, F.; Spindel, P.

1979-01-01

The origin of the universe as a quantum phenomenon leads to a self-consistently generated space-time structure in which the mass of the created particles is O (kappa/sup -1/2/). We interpret the origin of the universe as a phase transition in which the grand unified symmetry is spontaneously broken

Grand unified models including extra Z bosons

International Nuclear Information System (INIS)

Li Tiezhong

1989-01-01

The grand unified theories (GUT) of the simple Lie groups including extra Z bosons are discussed. Under authors's hypothesis there are only SU 5+m SO 6+4n and E 6 groups. The general discussion of SU 5+m is given, then the SU 6 and SU 7 are considered. In SU 6 the 15+6 * +6 * fermion representations are used, which are not same as others in fermion content, Yukawa coupling and broken scales. A conception of clans of particles, which are not families, is suggested. These clans consist of extra Z bosons and the corresponding fermions of the scale. The all of fermions in the clans are down quarks except for the standard model which consists of Z bosons and 15 fermions, therefore, the spectrum of the hadrons which are composed of these down quarks are different from hadrons at present

The return of the King: No-Scale F-SU(5

Directory of Open Access Journals (Sweden)

Tianjun Li

2017-01-01

Full Text Available We revisit the viable parameter space in No-Scale F-SU(5, examining the Grand Unified Theory within the context of the prevailing gluino mass limits established by the LHC. The satisfaction of both the No-Scale boundary condition and the experimentally measured Standard Model (SM like Higgs boson mass requires a lower limit on the gluino mass in the model space of about 1.9 TeV, which maybe not coincidentally is the current LHC supersymmetry search bound. This offers a plausible explanation as to why a supersymmetry signal has thus far not been observed at the LHC. On the contrary, since the vector-like flippon particles are relatively heavy due to the strict condition that the supersymmetry breaking soft term Bμ must vanish at the unification scale, we also cannot address the recently vanished 750 GeV diphoton resonance at the 13 TeV LHC. Therefore, No-Scale F-SU(5 returns as a King after the spurious 750 GeV diphoton excess was gone with the wind.

Prospects for mass unification at low energy scales

Energy Technology Data Exchange (ETDEWEB)

Volkas, R.R.

1995-12-31

A simple Pati-Salam SU(4) model with a low symmetry breaking scale of about 1000 TeV is presented. The analysis concentrates on calculating radiative corrections to tree level mass relations for third generation fermions. The tree-level relation m{sub b}/m{sub {tau}} = 1 predicted by such models can receive large radiative corrections up to about 50% due to threshold effects at the mass unification scale. These corrections are thus of about the same importance as those that give rise to renormalisation group running. The high figure of 50% can be achieved because l-loop graphs involving the physical charged Higgs boson give corrections to m{sub {tau}} -m{sub b} that are proportional to the large top quark mass. These corrections can either increase or decrease m{sub b}/m{sub {tau}} depending on the value of an unknown parameter. They can also be made to vanish through a fine-tuning. A related model of tree-level t-b-{tau} unification which uses the identification of SU(2){sub R} with custodial SU(2) is then discussed. A curious relation m{sub b}{approx} {radical}2m{sub {tau}} is found to be satisfied at tree-level in this model. The overall conclusion of this work is that the tree-level relation m{sub b}=m{sub {tau}} at low scales such as 1000 TeV or somewhat higher can produce a successful value for m{sub b}/m{sub {tau}} after corrections, but one must be mindful that radiative corrections beyond those incorporated through the renormalisation group can be very important. 14 refs., 7 figs.

Focus point gauge mediation in product group unification

Energy Technology Data Exchange (ETDEWEB)

Bruemmer, Felix [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ibe, Masahiro [Tokyo Univ., Kashiwa (Japan). Kavli IPMU, TODIAS; Tokyo Univ., Kashiwa (Japan). ICRR; Yanagida, Tsutomu T. [Tokyo Univ., Kashiwa (Japan). Kavli IPMU, TODIAS

2013-03-15

In certain models of gauge-mediated supersymmetry breaking with messenger fields in incomplete GUT multiplets, the radiative corrections to the Higgs potential cancel out during renormalization group running. This allows for relatively heavy superpartners and for a 125 GeV Higgs while the ne-tuning remains modest. In this paper, we show that such gauge mediation models with ''focus point'' behaviour can be naturally embedded into a model of SU(5) x U(3) product group unification.

New aspects of flavour model building in supersymmetric grand unification

Energy Technology Data Exchange (ETDEWEB)

Spinrath, Martin

2010-05-19

We derive predictions for Yukawa coupling ratios within Grand Unified Theories generated from operators with mass dimension four and five. These relations are a characteristic property of unified flavour models and can reduce the large number of free parameters related to the flavour sector of the Standard Model. The Yukawa couplings of the down-type quarks and charged leptons are affected within supersymmetric models by tan {beta}-enhanced threshold corrections which can be sizeable if tan {beta} is large. In this case their careful inclusion in the renormalisation group evolution is mandatory. We analyse these corrections and give simple analytic expressions and numerical estimates for them. The threshold corrections sensitively depend on the soft supersymmetry breaking parameters. Especially, they determine the overall sign of the corrections and therefore if the affected Yukawa couplings are enhanced or suppressed. In the minimal supersymmetric extension of the Standard Model many free parameters are introduced by supersymmetry breaking about which we make some plausible assumptions in our first simplified approach. In a second, more sophisticated approach we use three common breaking schemes in which all the soft breaking parameters at the electroweak scale can be calculated from only a handful of parameters. Within the second approach, we apply various phenomenological constraints on the supersymmetric parameters and find in this way new viable Yukawa coupling relations, for example y{sub {mu}}/y{sub s}=9/2 or 6 or y{sub {tau}}/y{sub b}=3/2 in SU(5). Furthermore, we study a special class of quark mass matrix textures for small tan {beta} where {theta}{sup u}{sub 13}={theta}{sup d}{sub 13}=0. We derive sum rules for the quark mixing parameters and find a simple relation between the two phases {delta}{sup u}{sub 12} and {delta}{sup d}{sub 12} and the right unitarity triangle angle {alpha} which suggests a simple phase structure for the quark mass matrices where

Flipped SU(5)xU(1){sub X} models from F-theory

Energy Technology Data Exchange (ETDEWEB)

Jiang Jing [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Li Tianjun, E-mail: tjli@physics.rutgers.ed [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States); Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Nanopoulos, Dimitri V. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States); Astroparticle Physics Group, Houston Advanced Research Center (HARC), Mitchell Campus, Woodlands, TX 77381 (United States); Academy of Athens, Division of Natural Sciences, 28 Panepistimiou Avenue, Athens 10679 (Greece); Xie Dan [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States)

2010-05-01

We systematically construct flipped SU(5)xU(1){sub X} models without and with bulk vector-like particles from F-theory. To realize the decoupling scenario, we introduce sets of vector-like particles in complete SU(5)xU(1) multiplets at the TeV scale, or at the intermediate scale, or at the TeV scale and high scale. To avoid the Landau pole problem for the gauge couplings, we can only introduce five sets of vector-like particles around the TeV scale. These vector-like particles can couple to the Standard Model singlet fields, and obtain suitable masses by Higgs mechanism. We study gauge coupling unification in detail. We show that the U(1){sub X} flux contributions to the gauge couplings preserve the SU(5)xU(1){sub X} gauge coupling unification. We calculate the SU(3){sub C}xSU(2){sub L} unification scales, and the SU(5)xU(1){sub X} unification scales and unified couplings. In most of our models, the high-scale or bulk vector-like particles can be considered as string-scale threshold corrections since their masses are close to the string scale. Furthermore, we discuss the phenomenological consequences of our models. In particular, in the models with TeV-scale vector-like particles, the vector-like particles can be observed at the Large Hadron Collider, the proton decay is within the reach of the future Hyper-Kamiokande experiment, the lightest CP-even Higgs boson mass can be increased, the hybrid inflation can be naturally realized, and the correct cosmic primordial density fluctuations can be generated.

Grand unified theories. Pt. 2

International Nuclear Information System (INIS)

Ellis, J.

1982-01-01

The author gives an introduction to the construction of grand unified theories on the base of the SU(3)xSU(2)xU(1) model of the strong, weak, and electromagnetic interactions. Especially he discusses the proton decay, neutrino masses and oscillations, and cosmological implications in connection with grand unified theories. (orig./HSI)

Distinguishing between SU(5) and flipped SU(5)

Energy Technology Data Exchange (ETDEWEB)

Dorsner, Ilja [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34014 Trieste (Italy); Fileviez Perez, Pavel [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34014 Trieste (Italy) and Pontificia Universidad Catolica de Chile, Facultad de Fisica, Casilla 306, Santiago 22 (Chile)]. E-mail: fileviez@higgs.fis.puc.cl

2005-01-13

We study in detail the d=6 operators for proton decay in the two possible matter unification scenarios based on SU(5) gauge symmetry. We investigate the way to distinguish between these two scenarios. The dependence of the branching ratios for the two body decays on the fermion mixing is presented in both cases. We point out the possibility to make a clear test of flipped SU(5) through the decay channel p->{pi}{sup +}{nu}-bar , and the ratio {tau}(p->K{sup 0}e{sub {alpha}}{sup +})/{tau}(p->{pi}{sup 0}e{sub {alpha}}{sup +})

A unified model of the strong and electroweak interactions based on the gauge group SU(18)L x SU(18)R

International Nuclear Information System (INIS)

Kim Il Kang

1986-01-01

On the basis of semi-simple gauge group G=SU(18) L x SU(18) R the unified theory of strong, weak and electromagnetic fields is constructed, and it is shown that the Weinberg angle and the energy of unification are in good agreement with the experimental values. (author)

Proceedings of the fourth workshop on grand unification

Energy Technology Data Exchange (ETDEWEB)

Weldon, H.A.; Langacker, P.; Steinhardt, P.J.

1983-01-01

This book compiles the papers presented at the fourth conference of grand unified theories of nuclear physics held in University of Pennsylvania April 1983. The topics covered were proton decay theory; angular distribution and flux of atmospheric neutrinos; atmospheric neutrinos and astrophysical neutrinos in proton decay experiments; review of future nucleon decay experiments; monopole experiments; searches for magnetic monopole; monopoles, gauge, fields and anomalies; darkmatter, galaxies and voids; adiabatic fluctuations; supersymmetry, supergravity, and Kaluza-Klein theories; superstring theory and superunification.

Summary talk

International Nuclear Information System (INIS)

Harari, H.

1978-10-01

A general overview is given in this high energy physics conference summary. Quantum chromodynamics as a theory of strong interactions and studied by experimental tests, SU(2) x U(1) theory of weak and electromagnetic interactions and its experimental tests, weak interactions above 100 GeV, simple unification of weak and electromagnetic interactions, and the grand and the ultimate unifications with extended supergravity are discussed. 28 references

Asymptotically free SU(5) models

International Nuclear Information System (INIS)

Kogan, Ya.I.; Ter-Martirosyan, K.A.; Zhelonkin, A.V.

1981-01-01

The behaviour of Yukawa and Higgs effective charges of the minimal SU(5) unification model is investigated. The model includes ν=3 (or more, up to ν=7) generations of quarks and leptons and, in addition, the 24-plet of heavy fermions. A number of solutions of the renorm-group equations are found, which reproduce the known data about quarks and leptons and, due to a special choice of the coupling constants at the unification point are asymptotically free in all charges. The requirement of the asymptotical freedom leads to some restrictions on the masses of particles and on their mixing angles [ru

Aspects of grand unification in higher dimensions

Energy Technology Data Exchange (ETDEWEB)

Wingerter, A.

2005-07-01

We consider various aspects of string phenomenology in the context of heterotic orbifold constructions, where special emphasis is laid on the connection between GUT models in extra dimensions and their relation to string theory. We investigate orbifold models with more general structure than the Z{sub 3} orbifold, on which most of the past research had focused. The picture of the heterotic brane world which naturally emerges allows us to make contact to field theoretic orbifold constructions in five and six dimensions, which have recently attracted much attention. We present a classification scheme for inequivalent orbifold models and apply the results to the case of Z{sub 6}-II point group. We develop the mathematical background for a stringy Higgs mechanism which allows us to lower the rank of the gauge group in the higher dimensions, which cannot be achieved by contemporary orbifold constructions. We provide all the calculational methods needed to unambiguously identify the gauge symmetry and to construct the matter representations. For specific model constructions, we focus on two promising gauge groups, namely on SO(10) and E{sub 6}. In the latter case, we derive a GUT model in six dimensions which has a standard model like gauge symmetry SU(3) x SU (2) x U(1) x U(1)' in four dimensions, and discuss its embedding into string theory. (orig.)

Grand unified theories

International Nuclear Information System (INIS)

Langacker, P.

1981-01-01

In this talk I discuss the present status of these theories and of their observational and experimental implications. In section II, I briefly review the standard SU 3 sup(c) x SU 2 x U 1 model of the strong and electroweak interactions. Although phenomenologically successful, the standard model leaves many questions unanswered. Some of these questions are addressed by grand unified theories, which are defined and discussed in Section III. The Georgi-Glashow SU 5 model is described, as are theories based on larger groups such as SO 10 , E 6 , or SO 16 . It is emphasized that there are many possible grand unified theories and that it is an experimental problem not only to test the basic ideas but to discriminate between models. (orig./HSI)

SAT Encoding of Unification in EL

Science.gov (United States)

Baader, Franz; Morawska, Barbara

Unification in Description Logics has been proposed as a novel inference service that can, for example, be used to detect redundancies in ontologies. In a recent paper, we have shown that unification in EL is NP-complete, and thus of a complexity that is considerably lower than in other Description Logics of comparably restricted expressive power. In this paper, we introduce a new NP-algorithm for solving unification problems in EL, which is based on a reduction to satisfiability in propositional logic (SAT). The advantage of this new algorithm is, on the one hand, that it allows us to employ highly optimized state-of-the-art SAT solvers when implementing an EL-unification algorithm. On the other hand, this reduction provides us with a proof of the fact that EL-unification is in NP that is much simpler than the one given in our previous paper on EL-unification.

Low-energy lepton violation from supersymmetric flipped SU(5)

Energy Technology Data Exchange (ETDEWEB)

Brahm, D.E.; Hall, L.J. (Physics Department, University of California, Berkeley, California 94720 (US) Theoretical Physics Group, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720)

1989-10-01

We construct a supersymmetric flipped SU(5){direct product}U(1) model which violates {ital R} parity and electron number at low energies, through a superpotential term (1/2{ital C}{sup {ital ijk}}L{sub i}L{sub j}E{sub k}{sup c}). Rotation of the electron and Higgs superfields makes this term also responsible for charged-lepton masses. The model employs a missing-partners mechanism for the Higgs fields and a seesaw mechanism for the neutrinos. It correctly predicts the approximate electron mass and several mass relations, as well as numerical values for the grand unification scale and the {ital C}{sup {ital ijk}} coefficients. The electron-neutrino Majorana mass is close to experimental limits, and provides constraints. Interesting {ital Z}{sup 0} decays are predicted: e.g., {ital Z}{sup 0}{r arrow}e{sup {minus}}{mu}{sup +}e{sup +}{mu}{sup {minus}} with invariant-mass peaks in the ({ital e},{mu}) channels.

Beyond the Standard Model (1/5)

CERN Multimedia

CERN. Geneva

2000-01-01

After a critical discussion of the questions left unanswered by the Standard Model, I will review the main attemps to construct new theories. In particular, I will discuss grand unification, supersymmetry, technicolour, and theories with extra dimensions.

The anomalous U(1){sub anom} symmetry and flavors from an SU(5) x SU(5){sup '} GUT in Z{sub 12-I} orbifold compactification

Energy Technology Data Exchange (ETDEWEB)

Kim, Jihn E. [Kyung Hee University, Department of Physics, Seoul (Korea, Republic of); Center for Axion and Precision Physics Research (IBS), Daejeon (Korea, Republic of); Kyae, Bumseok [Pusan National University, Department of Physics, Busan (Korea, Republic of); Nam, Soonkeon [Kyung Hee University, Department of Physics, Seoul (Korea, Republic of)

2017-12-15

In string compactifications, frequently the anomalous U(1) gauge symmetry appears which belongs to E{sub 8} x E{sub 8}{sup '} of the heterotic string. This anomalous U(1) gauge boson obtains mass at the compactification scale (∼ 10{sup 18} GeV) by absorbing one pseudoscalar (corresponding to the model-independent axion) from the second rank antisymmetric tensor field B{sub MN}. Below the compactification scale a global symmetry U(1){sub anom} results whose charge Q{sub anom} is the original gauge U(1) charge. This is the most natural global symmetry, realizing the ''invisible'' axion. This global symmetry U(1){sub anom} is suitable for a flavor symmetry. In the simplest compactification model with the flipped SU(5) grand unification, all the low energy parameters are calculated in terms of the vacuum expectation values of the standard model singlets. (orig.)

Testable flipped SU(5)xU(1){sub X} models

Energy Technology Data Exchange (ETDEWEB)

Jiang Jing [Institute of Theoretical Science, University of Oregon, Eugene, OR 97403 (United States); Li Tianjun [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States) and Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100080 (China) and Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854 (United States)]. E-mail: tjli@physics.rutgers.edu; Nanopoulos, Dimitri V. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States); Astroparticle Physics Group, Houston Advanced Research Center (HARC), Mitchell Campus, Woodlands, TX 77381 (United States); Academy of Athens, Division of Natural Sciences, 28 Panepistimiou Avenue, Athens 10679 (Greece)

2007-06-11

The little hierarchy between the GUT scale and the string scale may give us some hints that can be tested at the LHC. To achieve string-scale gauge coupling unification, we introduce additional vector-like particles. We require that these vector-like particles be standard, form complete GUT multiplets, and have masses around the TeV scale or close to the string scale. Interestingly, only the flipped SU(5)xU(1){sub X} models can work elegantly. We consider all possible sets of vector-like particles with masses around the TeV scale. And we introduce vector-like particles with masses close to the string scale which can mimic the string-scale threshold corrections. We emphasize that all of these vector-like particles can be obtained in the interesting flipped SU(5)xU(1){sub X} string models from the four-dimensional free fermionic string construction. Assuming the low-energy supersymmetry, high-scale supersymmetry, and split supersymmetry, we show that the string-scale gauge coupling unification can indeed be achieved in the flipped SU(5)xU(1){sub X} models. These models can be tested at the LHC by observing simple sets of vector-like particles at the TeV scale. Moreover, we discuss a simple flipped SU(5)xU(1){sub X} model with string-scale gauge coupling unification and high-scale supersymmetry by introducing only one pair of the vector-like particles at the TeV scale, and we predict the corresponding Higgs boson masses. Also, we briefly comment on the string-scale gauge coupling unification in the model with low-energy supersymmetry by introducing only one pair of the vector-like particles at the intermediate scale. And we briefly comment on the mixings among the SM fermions and the corresponding extra vector-like particles.

Nontrivial asymptotically nonfree gauge theories and dynamical unification of couplings

International Nuclear Information System (INIS)

Kubo, J.

1995-01-01

Evidence for the nontriviality of asymptotically nonfree (ANF) Yang-Mills theories is found on the basis of optimized perturbation theory. It is argued that these theories with matter couplings can be made nontrivial by means of the reduction of couplings, leading to the idea of the dynamical unification of couplings (DUC). The second-order reduction of couplings in the ANF SU(3)-gauged Higgs-Yukawa theory, which is assumed to be nontrivial here, is carried out to motivate independent investigations on its nontriviality and DUC

Induced gravity II: grand unification

Energy Technology Data Exchange (ETDEWEB)

Einhorn, Martin B. [Kavli Institute for Theoretical Physics, Kohn Hall,University of California,Santa Barbara, CA 93106-4030 (United States); Jones, D.R. Timothy [Kavli Institute for Theoretical Physics, Kohn Hall,University of California,Santa Barbara, CA 93106-4030 (United States); Dept. of Mathematical Sciences, University of Liverpool,Peach Street, Liverpool L69 3BX (United Kingdom)

2016-05-31

As an illustration of a renormalizable, asymptotically-free model of induced gravity, we consider an SO(10) gauge theory interacting with a real scalar multiplet in the adjoint representation. We show that dimensional transmutation can occur, spontaneously breaking SO(10) to SU(5)⊗U(1), while inducing the Planck mass and a positive cosmological constant, all proportional to the same scale v. All mass ratios are functions of the values of coupling constants at that scale. Below this scale (at which the Big Bang may occur), the model takes the usual form of Einstein-Hilbert gravity in de Sitter space plus calculable corrections. We show that there exist regions of parameter space in which the breaking results in a local minimum of the effective action giving a positive dilaton (mass){sup 2} from two-loop corrections associated with the conformal anomaly. Furthermore, unlike the singlet case we considered previously, some minima lie within the basin of attraction of the ultraviolet fixed point. Moreover, the asymptotic behavior of the coupling constants also lie within the range of convergence of the Euclidean path integral, so there is hope that there will be candidates for sensible vacua. Although open questions remain concerning unitarity of all such renormalizable models of gravity, it is not obvious that, in curved backgrounds such as those considered here, unitarity is violated. In any case, any violation that may remain will be suppressed by inverse powers of the reduced Planck mass.

Low-scale gaugino mass unification

International Nuclear Information System (INIS)

Endo, M.; Yoshioka, K.

2008-04-01

We present a new class of scenarios with the gaugino mass unification at the weak scale. The unification conditions are generally classified and then, the mirage gauge mediation is explored where gaugino masses are naturally unified and scalar partners of quarks and leptons have no mass hierarchy. The low-energy mass spectrum is governed by the mirage of unified gauge coupling which is seen by low-energy observers. We also study several explicit models for dynamically realizing the TeV-scale unification. (orig.)

Low-scale gaugino mass unification

Energy Technology Data Exchange (ETDEWEB)

Endo, M [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yoshioka, K [Kyoto Univ. (Japan). Dept. of Physics

2008-04-15

We present a new class of scenarios with the gaugino mass unification at the weak scale. The unification conditions are generally classified and then, the mirage gauge mediation is explored where gaugino masses are naturally unified and scalar partners of quarks and leptons have no mass hierarchy. The low-energy mass spectrum is governed by the mirage of unified gauge coupling which is seen by low-energy observers. We also study several explicit models for dynamically realizing the TeV-scale unification. (orig.)

ACADEMIC TRAINING LECTURE

CERN Multimedia

Academic Training; Tel. 73127

2001-01-01

2, 3, 4, 5 and 6 April REGULAR LECTURE PROGRAMME From 11:00 hrs - Main Auditorium bldg. 500 New Developments in Supersymmetry S. Raby / CERN-TH Introduction to supersymmetric grand unified theories. An introduction to the MSSM and different mechanisms for supersymmetry breaking. Then the details of SU(5) and SO(10) unification, the new gauge sector beyond the standard model, representations of quarks and leptons. Gauge and Yukawa coupling unification and some predictions.

Unification

International Nuclear Information System (INIS)

Iliopoulos, J.

1983-01-01

This chapter describes the weak and electromagnetic interactions by a gauge theory based on the group U(1)xSU(2). Discusses SO(10), E 6 , beyond gauge theories, Grassmann algebras, graded superalgebras, Majorana and Weyl spinors; particle representations; all possible supersymmetries of the S-matrix; representations in terms of fields; a simple field theory model; supersymmetry and gauge invariance; the breaking of supersymmetry; the supersymmetric extension of the standard model; and supersymmetry and grand-unified theories. Finds that the rate of approach to the symmetric, which is logarithmic for dimensionless couplings, is too slow to account for the high accuracy with which symmetries are observed in nature. Shows that scalar Q.E.D. in perturbation theory is not an I.R. attractor when one attempts to approach it via a class of theories with negative metric

Hyperquarks and bosonic preon bound states

International Nuclear Information System (INIS)

Schmid, Michael L.; Buchmann, Alfons J.

2009-01-01

In a model in which leptons, quarks, and the recently introduced hyperquarks are built up from two fundamental spin-(1/2) preons, the standard model weak gauge bosons emerge as preon bound states. In addition, the model predicts a host of new composite gauge bosons, in particular, those responsible for hyperquark and proton decay. Their presence entails a left-right symmetric extension of the standard model weak interactions and a scheme for a partial and grand unification of nongravitational interactions based on, respectively, the effective gauge groups SU(6) P and SU(9) G . This leads to a prediction of the Weinberg angle at low energies in good agreement with experiment. Furthermore, using evolution equations for the effective coupling strengths, we calculate the partial and grand unification scales, the hyperquark mass scale, as well as the mass and decay rate of the lightest hyperhadron.

Política en tiempos de la Guerra Grande: su impacto en la vida cotidiana de dos ciudades

Directory of Open Access Journals (Sweden)

Alfredo Alpini

2014-07-01

Full Text Available Ciudad y política se influyen mutuamente cuando se inicia la Guerra Grande y el sitio de Montevideo instalado por el ejército blanco en 1843, comprime a la ciudad al encierro de los tiempos de las murallas. A su vez, el conflicto trastoca la vida cotidiana por los sistemas de vigilancia que padecen sus habitantes. Montevideo dejó de expandirse y, como un espejo, nació otra ciudad, la Restauración. El gobierno y la policía de ambas ciudades controlan a sus habitantes, inspeccionan su vida privada, vigilan los espacios de sociabilidad y fiscalizan la comunicación. También, en el transcurso de la guerra, Montevideo y la Restauración fueron construyendo su propia imagen en base a la mirada mutua.

Grand unified theory precursors and nontrivial fixed points in higher-dimensional gauge theories

International Nuclear Information System (INIS)

Dienes, Keith R.; Dudas, Emilian; Gherghetta, Tony

2003-01-01

Within the context of traditional logarithmic grand unification at M GUT ≅10 16 GeV, we show that it is nevertheless possible to observe certain GUT states such as X and Y gauge bosons at lower scales, perhaps even in the TeV range. We refer to such states as 'GUT precursors'. These states offer an interesting alternative possibility for new physics at the TeV scale, and could be used to directly probe GUT physics even though the scale of gauge coupling unification remains high. Our results also give rise to a Kaluza-Klein realization of nontrivial fixed points in higher-dimensional gauge theories

Oasis in the desert: weakly broken parity in grand unified theories

International Nuclear Information System (INIS)

Senjanovic, G.

1981-07-01

A discussion of low energy parity restoration in simple grand unified theories, such as SO(10), is presented. The consistency of phenomenological requirements and unification constraints is emphasized and various predictions of the theory are stressed, in particular: substantially lighter W and Z bosons than in the standard model and increased stability of the proton with tau/sub p/ approx. = 10 38 years

Proton decay: Numerical simulations confront grand unification

International Nuclear Information System (INIS)

Brower, R.C.; Maturana, G.; Giles, R.C.; Moriarty, K.J.M.; Samuel, S.

1985-01-01

The Grand Unified Theories of the electromagnetic, weak and strong interactions constitute a far reaching attempt to synthesize our knowledge of theoretical particle physics into a consistent and compelling whole. Unfortunately, many quantitative predictions of such unified theories are sensitive to the analytically intractible effects of the strong subnuclear theory (Quantum Chromodynamics or QCD). The consequence is that even ambitious experimental programs exploring weak and super-weak interaction effects often fail to give definitive theoretical tests. This paper describes large-scale calculations on a supercomputer which can help to overcome this gap between theoretical predictions and experimental results. Our focus here is on proton decay, though the methods described are useful for many weak processes. The basic algorithms for the numerical simulation of QCD are well known. We will discuss the advantages and challenges of applying these methods to weak transitions. The algorithms require a very large data base with regular data flow and are natural candidates for vectorization. Also, 32-bit floating point arithmetic is adequate. Thus they are most naturally approached using a supercomputer alone or in combination with a dedicated special purpose processor. (orig.)

Gauge hierarchy problem and a nonscaling SU(5) model

International Nuclear Information System (INIS)

Tajnov, Eh.A.

1987-01-01

It is shown that the problems of gauge hierarchy anf Higgs hierarchy have a common origin, and a way is proposed for their combined solution in a no-scale supersymmetric SU(5) gauge model, related to the N=1 supergravity. A reason of appearance of the grand unification scale, M G , is the dimensional transmutation owing to quantum corrections to the classical potential. In this model, the Higgs hierarchy is established automatically by means of the singlet mechanism, which does not require a fine tuning of the superpotential parameters. The effective potential for the singlet field X has a minimum at =M G =2.2x10 16 GeV. The scale parameter M G does not depend on the gravitino mass and initial values of the Yukawa coupling constants but depends on initial values of the gauge constant α -1 (0)=22.7 and on the trilinear supergravity constant A=1.84 at a scale M=M p /√8π=2.43x10 18 GeV

Higgs scalar in the grand desert with observable proton lifetime in SU(5) and small neutrino masses in SO(10)

International Nuclear Information System (INIS)

Kynshi, M.L.; Parida, M.K.

1993-01-01

We find that the presence of a real scalar in the grand desert transforming as ζ(3,0,8) under SU(2) L xU(1) Y xSU(3) C ensures the agreement of the GUT predictions with the data from CERN LEP and proton lifetime (τ p ). The mass of ζ is predicted to be close to the Peccei-Quinn symmetry-breaking scale. The computation of the threshold effects in SU(5) with Higgs representations 24, 5, and 75 shows that the maximum allowed τ p for reasonable superheavy Higgs boson masses is accessible to experimental tests at low energies. The additional predictions in SO(10) are small neutrino masses compatible with solutions to the solar-neutrino problem and the dark matter of the Universe

String threshold corrections and flipped SU(5)

Energy Technology Data Exchange (ETDEWEB)

Antoniadis, I. (Ecole Polytechnique, Centre de Physique Theorique, 91 - Palaiseau (France) Theory Div., CERN, Geneva (Switzerland)); Ellis, J. (Theory Div., CERN, Geneva (Switzerland)); Lacaze, R. (Service de Physique Theorique, CEN-Saclay, 91 - Gif-sur-Yvette (France)); Nanopoulos, D.V. (Center for Theoretical Physics, Dept. of Physics, Texas A and M Univ., College Station, TX (United States) Astroparticle Physics Group, HARC, The Woodlands, TX (United States) Theory Div., CERN, Geneva (Switzerland))

1991-10-10

We revise previous calculations of the effective unification scale m{sub SU} at which the extrapolated low-energy gauge couplings should appear to become equal, and we show explicitly how to calculate m{sub SU} in the fermionic construction of four-dimensional strings. In the case of the flipped SU(5) GUT derived from the string, the SU(5) and U(1) couplings defined in the anti Danti R scheme become equal to g{sub SU} at m{sub SU} {approx equal} 1.76 x g{sub SU} x 10{sup 18} GeV. This scale is significantly larger than m{sub GUT}, the scale at which the low-energy SU(3) and SU(2) couplings become equal if extrapolated using the renormalization group equations of the minimal supersymmetric extension of the standard model. The existence of an intermediate SU(5) x U(1) phase could have an observable effect on the calculated value of sin{sup 2}{theta}{sub w}. (orig.).

Grandes remolques

Directory of Open Access Journals (Sweden)

Editorial, Equipo

1961-07-01

Full Text Available El empleo creciente del material pesado auxiliar en la construcción de obras de ingeniería civil ha motivado la fabricación de grandes plataformas, capaces de transportar toda clase de maquinaria auxiliar. En general, este tipo de maquinaria requiere medios de transporte, pues su circulación por carreteras es lenta, obstructiva y cara, siempre que se trate de grandes distancias, caso presente en la mayoría de ocasiones en que se exige un traslado de esta maquinaria de una a otra obra.

SU(5): to flip or not to flip

International Nuclear Information System (INIS)

Nanopoulos, D.V.; Wisconsin Univ., Madison,

1988-01-01

Flipped SU(5) possesses some unique features as a grand unified theory: elegant missing partner mechanism, see-saw neutrino masses, no Higgs adjoints. This last property makes flipped SU(5) the only known grand unified theory derivable from 4-dimensional superstrings. When derived from the superstrings, flipped SU(5) possesses, in addition a hierarchical fermion mass spectrum. All these recent developments involving flipped SU(5) are discussed in a detailed but simple way, including phenomenological consequences at low energies

Natural embedding of Peccei-Quinn symmetry in flavor grand unification

International Nuclear Information System (INIS)

Kim, J.E.

1981-08-01

Peccei and Quinn's global U(1)sub(A) symmetry can be embedded in grand unified schemes without an artificial requirement of imposing U(1)sub(A) symmetry, which results from the representation content of fermions and Higgs fields. Then, in some cases there results an ordinary axion with a mass approximately 100 keV. The axion mass is proportional to v -1 sub(A), where v -1 sub(A) is the scale of the actual U(1)sub(A) symmetry breakdown. (author)

Weak mixing angle and the SU(3)CxSU(3) model on M4xS1/(Z2xZ'2)

International Nuclear Information System (INIS)

Li Tianjun; Wei Liao

2002-05-01

We show that the desirable weak mixing angle sin 2 θ W =0.2312 at m Z scale can be generated naturally in the SU(3) C xSU(3) model on M 4 xS 1 /(Z 2 x Z 2 ') where the gauge symmetry SU(3) is broken down to SU(2) L xU(1) Y by orbifold projection. For a supersymmetric model with a TeV scale extra dimension, the SU(3) unification scale is about hundreds of TeVs at which the gauge couplings for SU(3) C and SU(3) can also be equal in the mean time. For the non-supersymmetric model, SU(2) L xU(1) Y are unified at order of 10 TeV. These models may serve as good candidates for physics beyond the SM or MSSM. (author)

Gauge theories

International Nuclear Information System (INIS)

Jarlskog, C.

An introduction to the unified gauge theories of weak and electromagnetic interactions is given. The ingredients of gauge theories and symmetries and conservation laws lead to discussion of local gauge invariance and QED, followed by weak interactions and quantum flavor dynamics. The construction of the standard SU(2)xU(1) model precedes discussion of the unification of weak and electromagnetic interactions and weak neutral current couplings in this model. Presentation of spontaneous symmetry breaking and spontaneous breaking of a local symmetry leads to a spontaneous breaking scheme for the standard SU(2)xU(1) model. Consideration of quarks, leptons, masses and the Cabibbo angles, of the four quark and six quark models and CP violation lead finally to grand unification, followed by discussion of mixing angles in the Georgi-Glashow model, the Higgses of the SU(5) model and proton/ neutron decay in SU(5). (JIW)

Restrictions on two Higgs doublet models and CP violation at the unification scale

International Nuclear Information System (INIS)

Athanasiu, G.G.

1987-01-01

In Part I we examine bounds from CP violation in the neutral K system on charged Higgs masses and couplings in models with two Higgs doublets. While CP violation is still due only to a non-zero phase in the Kobayashi-Maskawa matrix, there are additional short-distance contributions involving charged Higgs exchange rather than W boson exchange. By having CP violation in the mass matrix, but not in the kaon to two pions decay amplitude, largely due to Higgs exchange, it is possible to obtain a small value of ε'/ε. In Part II we obtain bounds on charged-Higgs-boson masses and couplings in two Higgs doublet models from their effects on neutral-B-meson mixing. The bounds are comparable to those obtained with additional assumptions from the neutral-K-system. Neutral-Higgs-boson effects on the spectrum and wave functions of tt bound states are examined in the same model. In the future they could lead to restrictions on, or discovery of, the corresponding neutral Higgs bosons if they have relatively low masses and enhanced couplings. Finally, in Part III, the three generation phase invariant measure of CP violation is shown to satisfy a simple and solvable renormalization group equation. Its value falls by four to eight orders of magnitude between the weak and grand unification scales in the standard model, as well as in its two Higgs and supersymmetric extensions. Such a small value of CP violation at the grand unification scale can pose a problem for baryogenesis; this avoided if there are heavy quarks with masses close to their fixed points

L-R asymmetry in gut's

International Nuclear Information System (INIS)

Karadayi, H.R.

1982-01-01

An idea of L-R asymmetry is proposed for the grand unification schemes. The idea provides an intrinsic mechanism to obtain standard model charges of fermions in the case of more than one weak gauge boson. It is elaborated within a scheme based on the partial symmetry SU(4)sub(C)xSU(2)sub(L)xSU(2)sub(R) where the coupling constants gsub(L) and gsub(R) corresponding to the chiral SU(2) factors are assumed to be different from each other. Then, the embedding of this structure within the simple symmetry SO(10) is shown. In both cases, a consistent description of vector particle masses is given. These two schemes are considered as primary models to realize the L-R asymmetry idea due to the lack of family unification. However, in a subsequent work, we will show that the SO(14) unification of the three families can be obtained within the framework of L-R asymmetry. All formulations are carried out with the aid of a mathematical method that we recently proposed for the Lie algebra representations of classical groups. (author)

Higher-derivative Lee-Wick unification

International Nuclear Information System (INIS)

Carone, Christopher D.

2009-01-01

We consider gauge coupling unification in Lee-Wick extensions of the Standard Model that include higher-derivative quadratic terms beyond the minimally required set. We determine how the beta functions are modified when some Standard Model particles have two Lee-Wick partners. We show that gauge coupling unification can be achieved in such models without requiring the introduction of additional fields in the higher-derivative theory and we comment on possible ultraviolet completions.

Gauge unification, non-local breaking, open strings

International Nuclear Information System (INIS)

Trapletti, M.

2005-01-01

The issue of non-local GUT symmetry breaking is addressed in the context of open string model building. We study Z N xZ M ' orbifolds with all the GUT-breaking orbifold elements acting freely, as rotations accompanied by translations in the internal space. We consider open strings quantized on these backgrounds, distinguishing whether the translational action is parallel or perpendicular to the D-branes. GUT breaking is impossible in the purely perpendicular case, non-local GUT breaking is instead allowed in the purely parallel case. In the latter, the scale of breaking is set by the compactification moduli, and there are no fixed points with reduced gauge symmetry, where dangerous explicit GUT-breaking terms could be located. We investigate the mixed parallel+perpendicular case in a Z 2 xZ 2 ' example, having also a simplified field theory realization. It is a new S 1 /Z 2 xZ 2 ' orbifold-GUT model, with bulk gauge symmetry SU(5)xSU(5) broken locally to the Standard Model gauge group. In spite of the locality of the GUT symmetry breaking, there is no localized contribution to the running of the coupling constants, and the unification scale is completely set by the length of S 1

The search for a realistic flipped SU(5) string model

Energy Technology Data Exchange (ETDEWEB)

Lopez, J.L. (Center for Theoretical Physics, Texas A and M Univ., College Station, TX (United States) Astroparticle Physics Group, Houston Advanced Research Center (HARC), The Woodlands, TX (United States)); Nanopoulos, D.V. (Center for Theoretical Physics, Texas A and M Univ., College Station, TX (United States) Astroparticle Physics Group, Houston Advanced Research Center (HARC), The Woodlands, TX (United States)); Yuan, K. (Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL (United States))

1993-07-05

We present an extensive search for a class of flipped SU(5) models built within the free fermionic formulation of the heterotic string. We describe a set of algorithms which constitute the basis for a computer program capable of generating systematically the massless spectrum and the superpotential of all possible models within the class we consider. Our search through the huge parameter space to be explored is simplified considerably by the constraint of N=1 spacetime supersymmetry and the need for extra Q, anti Q representations beyond the standard ones in order to possibly achieve string gauge coupling unification at scales of O(10[sup 18] GeV). Our results are remarkably simple and evidence the large degree of redundancy in this kind of constructions. We find one model with gauge group SU(5)xU(1)sub(Y tilde)xSO(10)[sub h]xSU(4)[sub h]xU(1)[sup 5] and fairly acceptable phenomenological properties. We study the D- and F-flatness constraints and the symmetry breaking pattern in this model and conclude that string gauge coupling unification is quite possible. (orig.)

Unification of space-time and internal symmetries through superstrings, with elementary or composite quarks

International Nuclear Information System (INIS)

Huebsch, T.

1987-01-01

Symmetry properties of a given physical system constrain greatly the theoretical models built in the attempt to describe the system. In complement, the symmetry properties of a system typically undergo dramatic changes during its evolution in time, underpinning the concept of phase transitions. Employing these two ideas we analyze models of Particle Physics at increasingly higher levels of unification, attempting to cover the wide span from the domain of experimentally accessible energies to scales where all the known interactions (including gravity) may be described as low-energy effects of the tremendous and intricate structure of Superstring theories. In particular, we study the scenario of compactification of the Heterotic Superstring theory involving Calabi-Yau manifolds and derive the basic properties of the effective point-field theory action, give a huge class of constructions and devise some techniques for future analysis. Further we study the possibility that the phase-transition from Superstrings to observed particles involves an intermediary phase where the observed particles exhibit compositeness, together with some consequences on the low-energy phenomenology. Finally we include our attempt to modify the SU(5) model, as one of the simplest Grand-unified models, to provide a solution to its difficulties. As we now show, the problems we were trying to address are so generic that some of them remain (in a disguised form) even at the present understanding of the Superstring theories, the most ample constructs of fundamental Physics so far

Lie groups and grand unified theories

International Nuclear Information System (INIS)

Gubitoso, M.D.

1987-01-01

This work presents some concepts in group theory and Lie algebras and, at same time, shows a method to study and work with semisimple Lie groups, based on Dynkin diagrams. The aproach taken is not completely formal, but it presents the main points of the elaboration of the method, so its mathematical basis is designed with the purpose of making the reading not so cumbersome to those who are interested only in a general picture of the method and its usefulness. At the end it is shown a brief review of gauge theories and two grand-unification models based on SO(13) and E 7 gauge groups. (author) [pt

Gauge coupling unification in superstring derived standard-like models

International Nuclear Information System (INIS)

Faraggi, A.E.

1992-11-01

I discuss gauge coupling unification in a class of superstring standard-like models, which are derived in the free fermionic formulation. Recent calculations indicate that the superstring unification scale is at O(10 18 GeV) while the minimal supersymmetric standard model is consistent with LEP data if the unification scale is at O(10 16 )GeV. A generic feature of the superstring standard-like models is the appearance of extra color triplets (D,D), and electroweak doublets (l,l), in vector-like representations, beyond the supersymmetric standard model. I show that the gauge coupling unification at O(10 18 GeV) in the superstring standard-like models can be consistent with LEP data. I present an explicit standard-like model that can realize superstring gauge coupling unification. (author)

Gauge-Higgs unification with brane kinetic terms

International Nuclear Information System (INIS)

Aranda, Alfredo; Diaz-Cruz, J. Lorenzo

2006-01-01

By identifying the Higgs field as an internal component of a higher-dimensional gauge field it is possible to solve the little hierarchy problem. The construction of a realistic model that incorporates such a gauge-Higgs unification is an important problem that demands attention. In fact, several attempts in this direction have already been put forward. In this Letter we single out one such attempt, a 6D SU(3) extended electroweak theory, where it is possible to obtain a Higgs mass prediction in accord with global fits. One shortcoming of the model is its prediction for the Weinberg angle, it is too large. We slightly modify the model by including brane kinetic terms in a way motivated by the orbifold action on the 6D fields. We show that in this way it is possible to obtain the correct Weinberg angle while keeping the desired results in the Higgs sector

On SU(8)sub(L)xSU(8)sub(R) grand unified model

International Nuclear Information System (INIS)

Pirogov, Yu.F.

1981-01-01

A set of general propositions is considered which ground the choice of the SU(8)sub(L)xSU(8)sub(R) group as a unified symmetry group. According to these propositions the group SU(8)sub(L)xSU(8)sub(R) is the most natural unified group, it is the maximal symmetry group of the kinetic term of the lagrangian single family which conserves the fermion number. A new principle is introduced. According to this principle, the mirror doubling of the fermion spectrum, necessary for renormalizability of the given unified model is, on the other hand, a manifestation of the extended conformal invariance at short distances [ru

Left-right gauge symmetry breaking by radiative corrections in supergravity

International Nuclear Information System (INIS)

Moxhay, P.; Yamamoto, K.

1984-01-01

A supersymmetric SU(2)sub(L) x SU(2)sub(R) x U(1)sub(B-L) gauge theory coupled to N = 1 supergravity is investigated. The scale of left-right gauge symmetry breaking is determined as Msub(R) proportional Msub(P) esup(-1/α) by radiative corrections through the logarithmic evolution of soft supersymmetry breakings. SU(2)sub(L) x SU(2)sub(R) x U(1)sub(B-L) may be embedded in SO(10) grand unification. Cosmological implications intrinsic to the present model are also discussed, which may give a constraint Msub(R) approx.= 10 9-12 GeV. (orig.)

Unification of electromagnetic, strong and weak interaction

International Nuclear Information System (INIS)

Duong Van Phi; Duong Anh Duc

1993-09-01

The Unification of Electromagnetic, Strong and Weak Interactions is realized in the framework of the Quantum Field Theory, established in an 8-dimensional Unified Space. Two fundamental, spinor and vector field equations are considered. The first of the matter particles and the second is of the gauge particles. Interaction Lagrangians are formed from the external and internal currents and the external and internal vector field operators. Generators of the local gauge transformations are the combinations of the matrices of the first field equation. (author). 15 refs

Standard coupling unification in SO(10), hybrid seesaw neutrino mass and leptogenesis, dark matter, and proton lifetime predictions

Energy Technology Data Exchange (ETDEWEB)

Parida, M.K.; Nayak, Bidyut Prava; Satpathy, Rajesh [Centre of Excellence in Theoretical and Mathematical Sciences,Siksha ‘O’ Anusandhan University,Khandagiri Square, Bhubaneswar 751030 (India); Awasthi, Ram Lal [Indian Institute of Science Education and Research,Knowledge City, Sector 81, SAS Nagar, Manauli 140306 (India)

2017-04-12

We discuss gauge coupling unification of SU(3){sub C}×SU(2){sub L}×U(1){sub Y} descending directly from non-supersymmetric SO(10) while providing solutions to the three outstanding problems of the standard model: neutrino masses, dark matter, and the baryon asymmetry of the universe. Conservation of matter parity as gauged discrete symmetry for the stability and identification of dark matter in the model calls for high-scale spontaneous symmetry breaking through 126{sub H} Higgs representation. This naturally leads to the hybrid seesaw formula for neutrino masses mediated by heavy scalar triplet and right-handed neutrinos. Being quadratic in the Majorana coupling, the seesaw formula predicts two distinct patterns of right-handed neutrino masses, one hierarchical and another not so hierarchical (or compact), when fitted with the neutrino oscillation data. Predictions of the baryon asymmetry via leptogenesis are investigated through the decays of both the patterns of RHν masses. A complete flavor analysis has been carried out to compute CP-asymmetries including washouts and solutions to Boltzmann equations have been utilised to predict the baryon asymmetry. The additional contribution to vertex correction mediated by the heavy left-handed triplet scalar is noted to contribute as dominantly as other Feynman diagrams. We have found successful predictions of the baryon asymmetry for both the patterns of right-handed neutrino masses. The SU(2){sub L} triplet fermionic dark matter at the TeV scale carrying even matter parity is naturally embedded into the non-standard fermionic representation 45{sub F} of SO(10). In addition to the triplet scalar and the triplet fermion, the model needs a nonstandard color octet fermion of mass ∼5×10{sup 7} GeV to achieve precision gauge coupling unification at the GUT mass scale M{sub U}{sup 0}=10{sup 15.56} GeV. Threshold corrections due to superheavy components of 126{sub H} and other representations are estimated and found to be

Psychotherapy Integration via Theoretical Unification

Directory of Open Access Journals (Sweden)

Warren W. Tryon

2017-01-01

Full Text Available Meaningful psychotherapy integration requires theoretical unification because psychotherapists can only be expected to treat patients with the same diagnoses similarly if they understand these disorders similarly and if they agree on the mechanisms by which effective treatments work. Tryon (in press has proposed a transtheoretic transdiagnostic psychotherapy based on an Applied Psychological Science (APS clinical orientation, founded on a BioPsychology Network explanatory system that provides sufficient theoretical unification to support meaningful psychotherapy integration. That proposal focused mainly on making a neuroscience argument. This article makes a different argument for theoretical unification and consequently psychotherapy integration. The strength of theories of psychotherapy, like all theory, is to focus on certain topics, goals, and methods. But this strength is also a weakness because it can blind one to alternative perspectives and thereby promote unnecessary competition among therapies. This article provides a broader perspective based on learning and memory that is consistent with the behavioral, cognitive, cognitive-behavioral, psychodynamic, pharmacologic, and Existential/Humanistic/Experiential clinical orientations. It thereby provides a basis for meaningful psychotherapy integration.

Symmetry Breaking, Unification, and Theories Beyond the Standard Model

Energy Technology Data Exchange (ETDEWEB)

Nomura, Yasunori

2009-07-31

A model was constructed in which the supersymmetric fine-tuning problem is solved without extending the Higgs sector at the weak scale. We have demonstrated that the model can avoid all the phenomenological constraints, while avoiding excessive fine-tuning. We have also studied implications of the model on dark matter physics and collider physics. I have proposed in an extremely simple construction for models of gauge mediation. We found that the {mu} problem can be simply and elegantly solved in a class of models where the Higgs fields couple directly to the supersymmetry breaking sector. We proposed a new way of addressing the flavor problem of supersymmetric theories. We have proposed a new framework of constructing theories of grand unification. We constructed a simple and elegant model of dark matter which explains excess flux of electrons/positrons. We constructed a model of dark energy in which evolving quintessence-type dark energy is naturally obtained. We studied if we can find evidence of the multiverse.

An SU(5) grand unified model with hadrons as nontopological solitons. Pt. 1

International Nuclear Information System (INIS)

Chen Shihao

1994-01-01

A new grand unified model containing the known three generations of quark and lepton in which hadrons are regarded as nontopological solitons formed from quarks is presented. According to the model leptons and quarks are the same in essence. The differences between them are caused by spontaneous symmetry breaking. When a quark is located inside a hadron, its properties will be the same as those of a known quark and its mass very small. When a quark is outside hadrons, its properties will be the same as those of a known lepton, its mass very large and it will rapidly decay. Except defining charge Q 0 and fermion number F 0 which are exactly conserved, we also define interior colour, interior charge and interior fermion number approximately conserved inside a hadron. The (L-B) conservation in the known SU(5) model corresponds to the fermion number F 0 conservation in the present model

Some comments on flipped SU(5) times U(1) and flipped unification in general

Energy Technology Data Exchange (ETDEWEB)

Barr, S.M. (Bartol Research Institute, University of Delaware, Newark, Delaware 19716 (US))

1989-10-01

A general group-theoretical discussion of flipped embeddings is given. In addition to the well-known flipped SU(5) and flipped SO(10), the existence of flipped E{sub 6} and E{sub 7} is shown, as well as several families and special cases of flipped embeddings. A possible physical reason, essentially based on the group theory of flipped embeddings, why nature prefers the low-energy group SU(3){times}SU(2){times}U(1) to alternatives such as SU(4){times}U(1) and SU(5) is pointed out.

Some comments on flipped SU(5)xU(1) and flipped unification in general

International Nuclear Information System (INIS)

Barr, S.M.

1989-01-01

A general group-theoretical discussion of flipped embeddings is given. In addition to the well-known flipped SU(5) and flipped SO(10), the existence of flipped E 6 and E 7 is shown, as well as several families and special cases of flipped embeddings. A possible physical reason, essentially based on the group theory of flipped embeddings, why nature prefers the low-energy group SU(3)xSU(2)xU(1) to alternatives such as SU(4)xU(1) and SU(5) is pointed out

The economic implications of Korean unification

OpenAIRE

Schmitz, Jonathan L.

2002-01-01

Approved for public release; distribution unlimited A major area of concern for Korean unification is the immense cost it will impose on South Korea. To lessen this burden, South Korea will need to initiate policy reforms that can ease the financial stress and repercussions of unification and create an integrated economic community with North Korea. At the same time, North Korea will need to create an environment that is conducive to economic integration by accepting and adopting reform me...

Neutrino masses and b - τ unification in the supersymmetric standard model

International Nuclear Information System (INIS)

Vissani, F.; Smirnov, A.Yu.

1994-05-01

There are several indications that the Majorana masses of the right-handed neutrino components, M R , are at the intermediate scale: M R ∼ (10 10 - 10 12 ) GeV or even lighter. The renormalization effects due to large Yukawa couplings of neutrinos from region of momenta M R G are studied in the supersymmetric standard model. It is shown that neutrino renormalization effect can increase the m b /m τ ratio up to (10/15)%. This strongly disfavors m b - m τ unification for low values of tan β s . Lower bound on M R and tan β from the b - τ unification condition were found. The implications of the results to the see-saw mechanism of the neutrino mass generation are discussed. (author). 17 refs, 4 figs

Structural convergence under reversible and irreversible monetary unification

NARCIS (Netherlands)

Beetsma, R.M.W.J.; Jensen, H.

2003-01-01

We explore endogenous monetary unification in the context of a model in which a country with serious structural distortions (and, hence, high inflation) is admitted into a monetary union once its economic structure has converged sufficiently towards that of the existing participants. If unification

Structural convergence under reversible and irreversible monetary unification

NARCIS (Netherlands)

Beetsma, R.M.W.J.; Jensen, H.

1999-01-01

We explore endogenous monetary unification in the context of a model in which a country with serious structural distortions (and, hence, high inflation) is admitted into a monetary union once its economic structure has converged sufficiently towards that of the existing participants. If unification

Restrictions on two Higgs doublet models and CP violation at the unification scale

International Nuclear Information System (INIS)

Athanasiu, G.G.

1987-04-01

Bounds on charged Higgs masses and couplings in models with two Higgs doublets are examined that came from CP violation in the neutral K system. Bounds on charged Higgs masses and couplings in two Higgs doublet models are also obtained from their effects on neutral-B-meson mixing. The bounds are found to be comparable to those obtained with additional assumptions from the neutral K system. The three generation phase invariant measure of CP violation is shown to satisfy a simple and solvable renormalization group equation. Its value is seen to fall by four to eight orders of magnitude between the weak and grand unification scales in the standard model, as well as in its two Higgs and supersymmetric extensions

Vanishing corrections on intermediate scale and implications for unification of forces

International Nuclear Information System (INIS)

Parida, M.K.

1996-02-01

In two-step breakings of a class of grand unified theories including SO(10), we prove a theorem showing that the scale (M I ) where the Pati-Salam gauge symmetry with parity breaks down to the standard gauge group, has vanishing corrections due to all sources emerging from higher scales (μ > M I ) such as the one-loop and all higher-loop effects, the GUT-threshold, gravitational smearing, and string threshold effects. Implications of such a scale for the unification of gauge couplings with small Majorana neutrino masses are discussed. In string inspired SO(10), we show that M I ≅ 5 x 10 12 GeV, needed for neutrino masses, with the GUT scale M U ≅ M str can be realized provided certain particle states in the predicted spectrum are light. (author). 28 refs, 1 tab

Case for neutrino oscillations

International Nuclear Information System (INIS)

Ramond, P.

1982-01-01

The building of a machine capable of producing an intense, well-calibrated beam of muon neutrinos is regarded by particle physicists with keen interest because of its ability of studying neutrino oscillations. The possibility of neutrino oscillations has long been recognized, but it was not made necessary on theoretical or experimental grounds; one knew that oscillations could be avoided if neutrinos were massless, and this was easily done by the conservation of lepton number. The idea of grand unification has led physicists to question the existence (at higher energies) of global conservation laws. The prime examples are baryon-number conservation, which prevents proton decay, and lepton-number conservation, which keeps neutrinos massless, and therefore free of oscillations. The detection of proton decay and neutrino oscillations would therefore be an indirect indication of the idea of Grand Unification, and therefore of paramount importance. Neutrino oscillations occur when neutrinos acquire mass in such a way that the neutrino mass eigenstates do not match the (neutrino) eigenstates produced by the weak interactions. We shall study the ways in which neutrinos can get mass, first at the level of the standard SU 2 x U 1 model, then at the level of its Grand Unification Generalizations

Hidden SUSY from precision gauge unification

Energy Technology Data Exchange (ETDEWEB)

Krippendorf, Sven; Nilles, Hans Peter [Bonn Univ. (Germany). Bethe Center for Theoretical Physics; Bonn Univ. (Germany). Physikalisches Inst.; Ratz, Michael [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Winkler, Martin Wolfgang [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2013-06-15

We revisit the implications of naturalness and gauge unification in the MSSM. We find that precision unification of the couplings in connection with a small {mu} parameter requires a highly compressed gaugino pattern as it is realized in mirage mediation. Due to the small mass difference between gluino and LSP, collider limits on the gluino mass are drastically relaxed. Without further assumptions, the relic density of the LSP is very close to the observed dark matter density due to coannihilation effects.

Hidden SUSY from precision gauge unification

International Nuclear Information System (INIS)

Krippendorf, Sven; Nilles, Hans Peter

2013-06-01

We revisit the implications of naturalness and gauge unification in the MSSM. We find that precision unification of the couplings in connection with a small μ parameter requires a highly compressed gaugino pattern as it is realized in mirage mediation. Due to the small mass difference between gluino and LSP, collider limits on the gluino mass are drastically relaxed. Without further assumptions, the relic density of the LSP is very close to the observed dark matter density due to coannihilation effects.

Dark matter from unification

DEFF Research Database (Denmark)

Kainulainen, Kimmo; Tuominen, Kimmo; Virkajärvi, Jussi Tuomas

2013-01-01

We consider a minimal extension of the Standard Model (SM), which leads to unification of the SM coupling constants, breaks electroweak symmetry dynamically by a new strongly coupled sector and leads to novel dark matter candidates. In this model, the coupling constant unification requires...... eigenstates of this sector and determine the resulting relic density. The results are constrained by available data from colliders and direct and indirect dark matter experiments. We find the model viable and outline briefly future research directions....... the existence of electroweak triplet and doublet fermions singlet under QCD and new strong dynamics underlying the Higgs sector. Among these new matter fields and a new right handed neutrino, we consider the mass and mixing patterns of the neutral states. We argue for a symmetry stabilizing the lightest mass...

Studi d'idoneità ambientale su grande scala a fini conservazionistici: il caso del Capriolo italico nel P.N. del Pollino

Directory of Open Access Journals (Sweden)

Alessandro Massolo

2003-10-01

Full Text Available Nonostante la loro grande diffusione negli ultimi decenni, i modelli di valutazione ambientale (MVA trovano tuttoggi scarsa applicazione pratica. Molte difficoltà s?incontrano non solo nel loro concreto utilizzo, ma anche nella validazione e applicazione. Spesso, il problema fondamentale consiste nella difficoltà di reperire dati biologici e geografici su grande scala che siano attendibili e omogenei. La gestione spesso però richiede valutazioni su grande scala e il problema diventa quindi rilevante. Nel presente lavoro sono descritte alcune procedure di modellizzazione e verifica a partire dai risultati di uno studio condotto sul capriolo nel Parco Nazionale del Pollino. A tale scopo, sono state utilizzate due delle più diffuse tecniche statistiche multivariate (Analisi della Funzione Discriminante e Regressione Logistica, confrontando modelli formulati con e senza l?uso di indici di complessità del paesaggio come variabili predittive. L?analisi è stata condotta a grande scala compatibilmente con le stime delle dimensioni degli home range della specie. Lo sviluppo di più modelli ha permesso di verificare l?adeguatezza delle tecniche utilizzate e l?efficacia dei più comuni indici di paesaggio, nel predire la distribuzione della specie. Le analisi ambientali sono state effettuate mediante l?uso di ArcView 3.2 e della sua estensione Patch Analyst, a partire da cartografia informatizzata come la carta di uso del suolo Corine Land Cover e i punti quotati IGMI. I modelli sono stati formulati da un set di dati provenienti dell?Appennino centro-settentrionale e validati con un set di dati locali (area di distribuzione e avvistamenti diretti, raccolti tra il 2001 e il 2003. Il confronto tra i modelli si è basato sulle loro capacità di classificazione (sensitività e sensibilità. Gli indici di paesaggio sono risultati critici nel predire correttamente la distribuzione della specie. Nella fase di validazione sui dati di partenza 3 dei 4 modelli

The minimal GUT with inflaton and dark matter unification

Science.gov (United States)

Chen, Heng-Yu; Gogoladze, Ilia; Hu, Shan; Li, Tianjun; Wu, Lina

2018-01-01

Giving up the solutions to the fine-tuning problems, we propose the non-supersymmetric flipped SU(5)× U(1)_X model based on the minimal particle content principle, which can be constructed from the four-dimensional SO(10) models, five-dimensional orbifold SO(10) models, and local F-theory SO(10) models. To achieve gauge coupling unification, we introduce one pair of vector-like fermions, which form a complete SU(5)× U(1)_X representation. The proton lifetime is around 5× 10^{35} years, neutrino masses and mixing can be explained via the seesaw mechanism, baryon asymmetry can be generated via leptogenesis, and the vacuum stability problem can be solved as well. In particular, we propose that inflaton and dark matter particles can be unified to a real scalar field with Z_2 symmetry, which is not an axion and does not have the non-minimal coupling to gravity. Such a kind of scenarios can be applied to the generic scalar dark matter models. Also, we find that the vector-like particle corrections to the B_s^0 masses might be about 6.6%, while their corrections to the K^0 and B_d^0 masses are negligible.

The minimal GUT with inflaton and dark matter unification

Energy Technology Data Exchange (ETDEWEB)

Chen, Heng-Yu; Gogoladze, Ilia [University of Delaware, Department of Physics and Astronomy, Bartol Research Institute, Newark, DE (United States); Hu, Shan [Hubei University, Department of Physics, Faculty of Physics and Electronic Sciences, Wuhan (China); Li, Tianjun [Chinese Academy of Sciences, Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China); University of Chinese Academy of Sciences, School of Physical Sciences, Beijing (China); Wu, Lina [Chinese Academy of Sciences, Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China); University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China)

2018-01-15

Giving up the solutions to the fine-tuning problems, we propose the non-supersymmetric flipped SU(5) x U(1){sub X} model based on the minimal particle content principle, which can be constructed from the four-dimensional SO(10) models, five-dimensional orbifold SO(10) models, and local F-theory SO(10) models. To achieve gauge coupling unification, we introduce one pair of vector-like fermions, which form a complete SU(5) x U(1){sub X} representation. The proton lifetime is around 5 x 10{sup 35} years, neutrino masses and mixing can be explained via the seesaw mechanism, baryon asymmetry can be generated via leptogenesis, and the vacuum stability problem can be solved as well. In particular, we propose that inflaton and dark matter particles can be unified to a real scalar field with Z{sub 2} symmetry, which is not an axion and does not have the non-minimal coupling to gravity. Such a kind of scenarios can be applied to the generic scalar dark matter models. Also, we find that the vector-like particle corrections to the B{sub s}{sup 0} masses might be about 6.6%, while their corrections to the K{sup 0} and B{sub d}{sup 0} masses are negligible. (orig.)

Gauge-Higgs unification with broken flavour symmetry

International Nuclear Information System (INIS)

Olschewsky, M.

2007-05-01

We study a five-dimensional Gauge-Higgs unification model on the orbifold S 1 /Z 2 based on the extended standard model (SM) gauge group SU(2) L x U(1) Y x SO(3) F . The group SO(3) F is treated as a chiral gauged flavour symmetry. Electroweak-, flavour- and Higgs interactions are unified in one single gauge group SU(7). The unified gauge group SU(7) is broken down to SU(2) L x U(1) Y x SO(3) F by orbifolding and imposing Dirichlet and Neumann boundary conditions. The compactification scale of the theory is O(1) TeV. Furthermore, the orbifold S 1 /Z 2 is put on a lattice. This setting gives a well-defined staring point for renormalisation group (RG) transformations. As a result of the RG-flow, the bulk is integrated out and the extra dimension will consist of only two points: the orbifold fixed points. The model obtained this way is called an effective bilayered transverse lattice model. Parallel transporters (PT) in the extra dimension become nonunitary as a result of the blockspin transformations. In addition, a Higgs potential V(Φ) emerges naturally. The PTs can be written as a product e A y e η e A y of unitary factors e A y and a selfadjoint factor e η . The reduction 48 → 35 + 6 + anti 6 + 1 of the adjoint representation of SU(7) with respect to SU(6) contains SU(2) L x U(1) Y x SO(3) F leads to three SU(2) L Higgs doublets: one for the first, one for the second and one for the third generation. Their zero modes serve as a substitute for the SM Higgs. When the extended SM gauge group SU(2) L x U(1) Y x SO(3) F is spontaneously broken down to U(1) em , an exponential gauge boson mass splitting occurs naturally. At a first step SU(2) L x U(1) Y x SO(3) F is broken to SU(2) L x U(1) Y by VEVs for the selfadjoint factor e η . This breaking leads to masses of flavour changing SO(3) F gauge bosons much above the compactification scale. Such a behaviour has no counterpart within the customary approximation scheme of an ordinary orbifold theory. This way tree

Necessity of intermediate mass scales in grand unified theories with spontaneously broken CP invariance

International Nuclear Information System (INIS)

Senjanovic, G.

1982-07-01

It is demonstrated that the spontaneous breakdown of CP invariance in grand unified theories requires the presence of intermediate mass scales. The simplest realization is provided by weakly broken left-right symmetry in the context of SU(2)sub(L) x SU(2)sub(R) x U(1)sub(B-L) model embedded in grand unified theories. (author)

Gauge field theories

International Nuclear Information System (INIS)

Leite Lopes, J.

1981-01-01

The book is intended to explain, in an elementary way, the basic notions and principles of gauge theories. Attention is centred on the Salem-Weinberg model of electro-weak interactions, as well as neutrino-lepton scattering and the parton model. Classical field theory, electromagnetic, Yang-Mills and gravitational gauge fields, weak interactions, Higgs mechanism and the SU(5) model of grand unification are also discussed. (U.K.)

Dirac gauginos, gauge mediation and unification

Energy Technology Data Exchange (ETDEWEB)

Benakli, K. [UPMC Univ. Paris 06 (France). Laboratoire de Physique Theorique et Hautes Energies, CNRS; Goodsell, M.D. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2010-03-15

We investigate the building of models with Dirac gauginos and perturbative gauge coupling unification. Here, in contrast to the MSSM, additional fields are required for unification, and these can naturally play the role of the messengers of supersymmetry breaking. We present a framework within which such models can be constructed, including the constraints that the messenger sector must satisfy; and the renormalisation group equations for the soft parameters, which differ from those of the MSSM. For illustration, we provide the spectrum at the electroweak scale for explicit models whose gauge couplings unify at the scale predicted by heterotic strings. (orig.)

Dirac Gauginos, Gauge Mediation and Unification

CERN Document Server

Benakli, K

2010-01-01

We investigate the building of models with Dirac gauginos and perturbative gauge coupling unification. Here, in contrast to the MSSM, additional fields are required for unification, and these can naturally play the role of the messengers of supersymmetry breaking. We present a framework within which such models can be constructed, including the constraints that the messenger sector must satisfy; and the renormalisation group equations for the soft parameters, which differ from those of the MSSM. For illustration, we provide the spectrum at the electroweak scale for explicit models whose gauge couplings unify at the scale predicted by heterotic strings.

Dirac gauginos, gauge mediation and unification

International Nuclear Information System (INIS)

Benakli, K.

2010-03-01

We investigate the building of models with Dirac gauginos and perturbative gauge coupling unification. Here, in contrast to the MSSM, additional fields are required for unification, and these can naturally play the role of the messengers of supersymmetry breaking. We present a framework within which such models can be constructed, including the constraints that the messenger sector must satisfy; and the renormalisation group equations for the soft parameters, which differ from those of the MSSM. For illustration, we provide the spectrum at the electroweak scale for explicit models whose gauge couplings unify at the scale predicted by heterotic strings. (orig.)

China’s unification: Myth or reality?

Directory of Open Access Journals (Sweden)

Estrada Mario Arturo Ruiz

2014-01-01

Full Text Available This paper evaluates the prospect of a possible unification between People’s Republic of China (Mainland China and Republic of China (Taiwan from a multi-dimensional perspective which encompasses the political, social, economic, and technological dimensions. The underlying idea is to evaluate the possibility of a partial or total reunification between the two countries in a more comprehensive way than just assessing the economic costs and benefits. Our evaluation is based on the application of the GDRI-Model, which looks at unification and regional integration simultaneously from the political, economic, social and technological perspectives.

Logarithmic unification from symmetries enhanced in the sub-millimeter infrared

International Nuclear Information System (INIS)

Arkani-Hamed, Nima; Dimopoulos, Savas; March-Russell, John

1999-01-01

In theories with TeV string scale and sub-millimeter extra dimensions the attractive picture of logarithmic gauge coupling unification at 10 16 GeV is seemingly destroyed. In this paper we argue to the contrary that logarithmic unification can occur in such theories. The rationale for unification is no longer that a gauge symmetry is restored at short distances, but rather that a geometric symmetry is restored at large distances in the bulk away from our 3-brane. The apparent ''running'' of the gauge couplings to energies far above the string scale actually arises from the logarithmic variation of classical fields in (sets of) two large transverse dimensions. We present a number of N = 2 and N = 1 supersymmetric D-brane constructions illustrating this picture for unification

Violation of the Appelquist-Carazzone decoupling in a nonsupersymmetric grand unified theory

International Nuclear Information System (INIS)

Chankowski, Piotr H.; Wagner, Jakub

2008-01-01

We point out that in nonsupersymmetric grand unified theories, in which the SU(5) gauge symmetry is broken down to the standard model gauge group by a 24 Higgs multiplet the Appelquist-Carazzone decoupling is violated. This is because the SU(2) L Higgs triplet contained in the 24 acquires a dimension-full coupling to the SU(2) L Higgs doublets which is proportional to the grand unified symmetry breaking vacuum expectation value. As a result, at one-loop heavy gauge and Higgs fields contribution to tadpoles generates a vacuum expectation value of the triplet which is not suppressed for V→∞ and violates the custodial symmetry

Avoiding domain wall problem in SU(N) grand unified theories

International Nuclear Information System (INIS)

Fujimoto, Y.; Zhiyong, Z.

1982-08-01

We look for the possibility of embedding the discrete sub-group of U(1)-Pecci-Quinn symmetry into the continuous one to avoid the domain wall problem. We find, within some restricted context, among various SU(N) models only one-family SU(5) and SU(6). (author)

New hierarchy in GUTs based on SU(n,1)/SU(n)U(1) SUGRA

International Nuclear Information System (INIS)

Hayashi, M.J.; Murayama, Akihiro

1985-01-01

Grand unified theories (GUTs) in the framework of SU(n, 1)/SU(n) x U(1) supergravity are discussed which naturally generate a new hierarchy, Msub(P) (Planck mass): Msub(X) (GUT scale):msub(3/2) (gravitino mass):m (explicit supersymmetry breaking scale)=1:epsilon:epsilon 3 :epsilon 5 α(Msub(X)) with Msub(P) as the only input mass scale. The SUSY breaking scale m is expected to be fixed radiatively as mproportionalMsub(W), i.e., epsilonproportional10 -3 . Our method would be applicable to any GUT based on SU(n, 1)/SU(n) x U(1) supergravity. (orig.)

Grand unified supersymmetric Higgs bosons as pseudo-Goldstone particles

International Nuclear Information System (INIS)

Barbieri, R.; Dvali, G.; Strumia, A.

1993-01-01

We reconsider the possibility that the Higgs doublet responsible for the breaking of the electroweak gauge group be quasi-Goldstone bosons of a spontaneously broken approximate global symmetry of the theory. Supersymmetric SU(5) and SO(10) gauge models are discussed. The main phenomenological consequence of this viewpoint is the possible existence at the Fermi scale of a quasi-stable particle, most likely a Lorentz scalar, with the same colour and charge as a down quark. Its existence is a generic feature of models based on SO(10). The associated phenomoenological is illustrated. We also show how the phenomenology of the minimal SU(5) theory, already proposed, gets tightly constrained by the consideration of coupling constant unification without any assumption, otherwise crucial, on the superheavy threshold effects. (orig.)

Gauge-Higgs unification with broken flavour symmetry

Energy Technology Data Exchange (ETDEWEB)

Olschewsky, M.

2007-05-15

We study a five-dimensional Gauge-Higgs unification model on the orbifold S{sup 1}/Z{sub 2} based on the extended standard model (SM) gauge group SU(2){sub L} x U(1){sub Y} x SO(3){sub F}. The group SO(3){sub F} is treated as a chiral gauged flavour symmetry. Electroweak-, flavour- and Higgs interactions are unified in one single gauge group SU(7). The unified gauge group SU(7) is broken down to SU(2){sub L} x U(1){sub Y} x SO(3){sub F} by orbifolding and imposing Dirichlet and Neumann boundary conditions. The compactification scale of the theory is O(1) TeV. Furthermore, the orbifold S{sup 1}/Z{sub 2} is put on a lattice. This setting gives a well-defined staring point for renormalisation group (RG) transformations. As a result of the RG-flow, the bulk is integrated out and the extra dimension will consist of only two points: the orbifold fixed points. The model obtained this way is called an effective bilayered transverse lattice model. Parallel transporters (PT) in the extra dimension become nonunitary as a result of the blockspin transformations. In addition, a Higgs potential V({phi}) emerges naturally. The PTs can be written as a product e{sup A{sub y}}e{sup {eta}}e{sup A{sub y}} of unitary factors e{sup A{sub y}} and a selfadjoint factor e{sup {eta}}. The reduction 48 {yields} 35 + 6 + anti 6 + 1 of the adjoint representation of SU(7) with respect to SU(6) contains SU(2){sub L} x U(1){sub Y} x SO(3){sub F} leads to three SU(2){sub L} Higgs doublets: one for the first, one for the second and one for the third generation. Their zero modes serve as a substitute for the SM Higgs. When the extended SM gauge group SU(2){sub L} x U(1){sub Y} x SO(3){sub F} is spontaneously broken down to U(1){sub em}, an exponential gauge boson mass splitting occurs naturally. At a first step SU(2){sub L} x U(1){sub Y} x SO(3){sub F} is broken to SU(2){sub L} x U(1){sub Y} by VEVs for the selfadjoint factor e{sup {eta}}. This breaking leads to masses of flavour changing SO(3){sub F

SU(5) finite unified theories and the mass of the top quark

International Nuclear Information System (INIS)

Mondragon, M.; Zoupanos, G.

1994-01-01

We present results of a study of phenomenologically interesting SU(5) supersymmetric GUT's, which are finite to all-loops before spontaneous symmetry breaking. The finiteness conditions provide the spontaneously broken theory with relationships among the Yukawa and gauge couplings at the unification point. These in turn predict a heavy top quark mass (∼175-190 GeV). (orig.)

Phenomenology of the SU(3)cxSU(3)LxU(1)X model with exotic charged leptons

International Nuclear Information System (INIS)

Salazar, Juan C.; Ponce, William A.; Gutierrez, Diego A.

2007-01-01

A phenomenological analysis of the three-family model based on the local gauge group SU(3) c xSU(3) L xU(1) X with exotic charged leptons, is carried out. Instead of using the minimal scalar sector able to break the symmetry in a proper way, we introduce an alternative set of four Higgs scalar triplets, which combined with an anomaly-free discrete symmetry, produce quark and charged lepton mass spectrum without hierarchies in the Yukawa coupling constants. We also embed the structure into a simple gauge group and show some conditions to achieve a low energy gauge coupling unification, avoiding possible conflict with proton decay bounds. By using experimental results from the CERN-LEP, SLAC linear collider, and atomic parity violation data, we update constraints on several parameters of the model

Unification of Patrimonial Laws Governing International Trade

DEFF Research Database (Denmark)

Lando, Ole

2016-01-01

Should the laws of the world dealing with cross-border transactions be unified? Such unification presupposes an agreement on what we understand by ‘law’ and what its sources are. The drafters of uniform laws and lawyers who are preoccupied with comparative law often ask themselves: Is there, among...... the nations, a common core of legal values? If there is, this will facilitate legal unification. It will also make the international law-making easier if, in exceptional cases, a court is permitted to disregard a legal rule....

Dark Matter in SuperGUT Unification Models

International Nuclear Information System (INIS)

Olive, Keith A

2011-01-01

After a brief update on the prospects for dark matter in the constrained version of the MSSM (CMSSM) and its differences with models based on minimal supergravity (mSUGRA), I will consider the effects of unifying the supersymmetry-breaking parameters at a scale above M GUT . One of the consequences of superGUT unification, is the ability to take vanishing scalar masses at the unification scale with a neutralino LSP dark matter candidate. This allows one to resurrect no-scale supergravity as a viable phenomenological model.

An Ordering Linear Unification Algorithm

Institute of Scientific and Technical Information of China (English)

胡运发

1989-01-01

In this paper,we present an ordering linear unification algorithm(OLU).A new idea on substituteion of the binding terms is introduced to the algorithm,which is able to overcome some drawbacks of other algorithms,e.g.,MM algorithm[1],RG1 and RG2 algorithms[2],Particularly,if we use the directed eyclie graphs,the algoritm needs not check the binding order,then the OLU algorithm can also be aplied to the infinite tree data struceture,and a higher efficiency can be expected.The paper focuses upon the discussion of OLU algorithm and a partial order structure with respect to the unification algorithm.This algorithm has been implemented in the GKD-PROLOG/VAX 780 interpreting system.Experimental results have shown that the algorithm is very simple and efficient.

Possible test of grand unification in the double beta-decay

International Nuclear Information System (INIS)

Faessler, A.

1988-01-01

The more successful grand unified theories predict that the neutrino is identical with its antiparticle and therefore is a Majorana neutrino which violates lepton number conservation. Such a neutrino should have a finite mass and also a small right handed weak interaction. If the double neutrinoless beta decay is observed with the full decay energy in the two electrons, it would establish that the electron neutrino is a Majorana particle. It is shown that the relativistic corrections of the nucleonic wave functions are essential for determining an upper limit of the right handedness from the measured lower limit of the life-time against the neutrinoless double beta decay. The upper limit for the right handedness of the weak interaction derived from the lower limit of the life-times against the neutrinoless beta decay is vertical stroke vertical stroke -8 and the upper limit for the neutrino mass is vertical stroke ν m>vertical stroke + -decay in proton rich nuclei, one can explain the long standing puzzle of the quenching of the Gamow-Teller strength in agreement with the data. (orig.)

Electroweak interaction parameters

International Nuclear Information System (INIS)

Marciano, W.J.

1984-01-01

After a presentation of the experimentally determined parameters of the standard SU(3) x SU(2) x U(1) model the author discusses the definition of the Weinberg angle. Then masses and widths of the intermediate vector bosons are considered in the framework of the Weinberg-Salam theory with radiative corrections. Furthermore the radiative decays of these bosons are discussed. Then the relations between the masses of the Higgs boson and the top quark are considered. Thereafter grand unification is briefly discussed with special regards to the SU(5) prediction of some observable parameters. Finally some speculations are made concerning the observation of radiative decays in the UA1 experiments. (HSI)

Einstein's dream : the space-time unification of fundamental forces

Energy Technology Data Exchange (ETDEWEB)

Salam, A [International Centre for Theoretical Physics, Trieste (Italy)

1981-06-01

The historical developments in physics which started with Galileo in the 11th century, Newton in the 17 century, culminated in the unification of space-time by Einstein in this century are traced. The theories put forward by Einstein himself and by subsequent workers in the field after him, regarding the unification of all basic forces of nature (i.e.) the electromagnetic and the gravitational ones and the weak and strong nuclear forces are discussed. The experiments being conducted in Kolar and other places to detect a heavier photon which would be a positive proof of the validity of the unification theory, are touched upon. The possible application of this concept even in industry has been pointed out.

Unification and geometrization of physics in the cosmological context

International Nuclear Information System (INIS)

Heller, M.; Watykanskie Obserwatorium Astronomiczne, Vatican

1991-01-01

Einstein belived that a good physical theory should posses an ''inner perfection''. Trace the inner perfection of the present gauge theories by contemplating their geometric structures (in terms of fibre bundles). The search for the ultimate symmetry of the unification of physics unavoidably leads to the unification of physics and cosmology. 4 figs., 23 refs. (author)

Two Higgs doublets in SO(10) model

International Nuclear Information System (INIS)

Asatryan, G.M.

1989-01-01

An SO(10) grand unification model is suggested with two light Higgs doublets, whose vacuum expectation values are connected with the SU(2) L xU(1) Y electroweak group breaking. Taking into account the naturality condition associated with absence of flavor changing neutral currents, a certain form of the quark mass matrices. As a result, the proton lifetime in the SO(10) model turns to be strongly restrained

Radiative breaking of cosmologically acceptable grand unified theories

International Nuclear Information System (INIS)

Gato, B.; Leon, J.; Quiros, M.

1984-01-01

We present a cosmologically acceptable grand unified model where the breaking of SU(5) proceeds through radiative corrections induced by supergravity soft-breaking terms. The breaking scale is determined by dimensional transmutation. The model is compatible with the radiative breaking of SU(2)sub(L)xU(1)sub(Y) which provides an experimentally accessible low energy particle spectrum and small top quark mass. (orig.)

Strings: A possible alternative explanation for the Unification of Gravitation Field and Electromagnetic Field

Science.gov (United States)

Rivera, Susana

Throughout the last century, since the last decades of the XIX century, until present day, there had been many attempts to achieve the unification of the Forces of Nature. First unification was done by James Clerk Maxwell, with his Electromagnetic Theory. Then Max Plank developed his Quantum Theory. In 1905, Albert Einstein gave birth to the Special Relativity Theory, and in 1916 he came out with his General Relativity Theory. He noticed that there was an evident parallelism between the Gravitational Force, and the Electromagnetic Force. So, he tried to unify these forces of Nature. But Quantum Theory interposed on his way. On the 1940’s it had been developed the Quantum Electrodynamics (QED), and with it, the unified field theory had an arise interest. On the 60’s and 70’s there was developed the Quantum Chromodynamics (QCD). Along with these theories came the discovery of the strong interaction force and weak interaction force. And though there had been many attempts to unify all these forces of the nature, it could only be achieved the Unification of strong interaction, weak interaction and Electromagnetic Force. On the late 80”s and throughout the last two decades, theories such as “super-string theory”, “or the “M-theory”, among others, groups of Scientists, had been doing grand efforts and finally they came out with the unification of the forces of nature, being the only limitation the use of more than 11 dimensions. Using an ingenious mathematical tool known as the super symmetries, based on the Kaluza - Klein work, they achieve this goal. The strings of these theories are in the rank of 10-33 m. Which make them undetectable. There are many other string theories. The GEUFT theory is based on the existence of concentrated energy lines, which vibrates, expands and contracts, submitting and absorbing energy, matter and antimatter, and which yields a determined geometry, that gives as a result the formation of stars, galaxies, nebulae, clusters

Beyond the CMSSM without an Accelerator: Proton Decay and Direct Dark Matter Detection

CERN Document Server

Ellis, John; Luo, Feng; Nagata, Natsumi; Olive, Keith A; Sandick, Pearl

2016-01-01

We consider two potential non-accelerator signatures of generalizations of the well-studied constrained minimal supersymmetric standard model (CMSSM). In one generalization, the universality constraints on soft supersymmetry-breaking parameters are applied at some input scale $M_{in}$ below the grand unification (GUT) scale $M_{GUT}$, a scenario referred to as `sub-GUT'. The other generalization we consider is to retain GUT-scale universality for the squark and slepton masses, but to relax universality for the soft supersymmetry-breaking contributions to the masses of the Higgs doublets. As with other CMSSM-like models, the measured Higgs mass requires supersymmetric particle masses near or beyond the TeV scale. Because of these rather heavy sparticle masses, the embedding of these CMSSM-like models in a minimal SU(5) model of grand unification can yield a proton lifetime consistent with current experimental limits, and may be accessible in existing and future proton decay experiments. Another possible signat...

On two-particle N=1 supersymmetric composite grand unified models

International Nuclear Information System (INIS)

Pirogov, Yu.F.

1984-01-01

A class of two-particle N=1 supersymmetric composite grand unified models, satisfying the anomaly matching and cancellation conditions, n-independence and survival hypothesis is considered. A unique admissible set of the light states, containing spectator states on a par with the composite ones is found. At low mass scales this set contains exactly four families of ordinary fermions without any additional exotics. The interactions of the light states at distances greater than the compositeness radius are described by the N=1 sypersymmetric chiral grand unified model [SU(6)] 2 (or [SU(8)] 2 with a fixed set of four second-rank tensors as matter fields

Prospects for further unification

International Nuclear Information System (INIS)

Ne'eman, Y.

1983-07-01

We review the unification of weak and electromagnetic interactions (QAD), the prevalent color gauge theory of the strong interactions (QCD) and attempts to embed both these theories in a further Unified Gauge Theory. We discuss the related advances in cosmology and touch upon other approaches to the understanding of particles and fields. 44 references

Phenomenology of the SU(3)c x SU(3)L x U(1)X model with right-handed neutrinos

International Nuclear Information System (INIS)

Gutierrez, D.A.; Ponce, W.A.; Sanchez, L.A.

2006-01-01

A phenomenological analysis of the three-family model based on the local gauge group SU(3) c x SU(3) L x U(1) X with right-handed neutrinos is carried out. Instead of using the minimal scalar sector able to break the symmetry in a proper way, we introduce an alternative set of four Higgs scalar triplets, which combined with an anomaly-free discrete symmetry, produces a quark mass spectrum without hierarchies in the Yukawa coupling constants. We also embed the structure into a simple gauge group and show some conditions for achieving a low energy gauge coupling unification, avoiding possible conflict with proton decay bounds. By using experimental results from the CERN-LEP, SLAC linear collider, and atomic parity violation data, we update constraints on several parameters of the model. (orig.)

Rare B decays, rare τ decays, and grand unification

International Nuclear Information System (INIS)

Sher, M.; Yuan, Y.

1991-01-01

In multi-Higgs-boson extensions of the standard model, tree-level flavor-changing neutral currents exist naturally, unless suppressed by some symmetry. For a given rate, the exchanged scalar or pseudoscalar mass is very sensitive to the flavor-changing coupling between the first two generations. Since the Yukawa couplings of the first two generations are unknown and certainly very small, bounds which rely on some assumed value of this flavor-changing coupling are quite dubious. One might expect the size (and reliability) of the Yukawa couplings involving the third generation to be greater. In this paper, we consider processes involving τ's and B's, and determine the bounds on the flavor-changing couplings which involve third-generation fields. The strongest bound in the quark sector comes from B-bar B mixing and in the lepton sector, surprisingly, from μ→eγ. It is then noted that the flavor-changing couplings in the quark sector are related to those in the lepton sector in many grand unified theories, and one can ask whether an analysis of rare τ decays or rare B decays will provide the strongest constraints. We show that rare B decays provide the strongest bounds, and that no useful information can be obtained from rare τ decays. It is also noted that the most promising decay modes are B→Kμτ and B s →μτ, and we urge experimenters to look for rare decay modes of the B in which a τ is in the final state

A non Supersymmetric SO(10) Grand Unified Model for All the Physics below $M_{GUT}$

CERN Document Server

Altarelli, Guido

2013-01-01

We present a renormalizable non supersymmetric Grand Unified SO(10) model which, at the price of a large fine tuning, is compatible with all compelling phenomenological requirements below the unification scale and thus realizes a minimal extension of the SM, unified in SO(10) and describing all known physics below $M_{GUT}$. These requirements include coupling unification at a large enough scale to be compatible with the bounds on proton decay; a Yukawa sector in agreement with all the data on quark and lepton masses and mixings and with leptogenesis as the origin of the baryon asymmetry of the Universe; an axion arising from the Higgs sector of the model, suitable to solve the strong CP problem and to account for the observed amount of Dark Matter. The above constraints imposed by the data are very stringent and single out a particular breaking chain with the Pati-Salam group at an intermediate scale $M_I\\sim10^{11}$ GeV.

Testing GUTs: where do monopoles fit

International Nuclear Information System (INIS)

Ellis, J.

1982-10-01

The report shows why the inadequacies of the standard model of elementary particles impel some theorists toward embedding the strong, weak and electromagnetic interactions in a simple GUT group, and explains why the grand unification scale and hence the GUM (Grand Unified Monopoles) mass are expected to be so large (greater than or equal to 10 14 GeV). It goes on to describe some model GUTs, notably minimal SU(5) and supersymmetric (susy) GUTs. The grand unified analogues of generalized Cabibbo mixing angles are introduced relevant to the prediction of baryon decay modes in different theories as well as to the Decay modes catalyzed by GUMs. Phenomenologies of conventional and susy GUTs are contrasted including the potential increase in the grand unification scale as well as possible different baryon decay modes in susy GUTs. The phenomenology of GUMs is discussed, principally their ability to catalyze baryon decays. Some of the astrophysical and cosmological constraints on GUMs, GUMs, which make it difficult to imagine ever seeing a GUM and may impose serious restrictions on GUT model-building via their behavior in the very early universe are introduced. Finally, the reasons why GUMs are crucial aspects and tests of GUTs are summarized

Witten's loop in the flipped SU(5) unification

Energy Technology Data Exchange (ETDEWEB)

Malinský, Michal, E-mail: malinsky@ipnp.troja.mff.cuni.cz [Institute of Particle and Nuclear Physics, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovičkách 2, 180 00 Praha 8 (Czech Republic); Rodríguez, Carolina Arbeláez [Centro de Física Teórica de Partículas, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais 1, 1049-001, Lisboa Portugal and AHEP Group, Instituto de Física Corpuscular - C.S.I.C./Uni (Spain); Kolešová, Helena [Institute of Particle and Nuclear Physics, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovičkách 2, 180 00 Praha 8, Czech Republic and Faculty of Nuclear Sciences and Physical Engineering, Czech Techni (Czech Republic)

2014-06-24

We study a very simple, yet potentially realistic renormalizable flipped SU(5) scenario in which the right-handed neutrino masses are generated at very high energies by means of a two-loop diagram similar to that identified by E. Witten in the early 1980's in the SO(10) GUT framework. This mechanism leaves its traces in the baryon number violating signals such as the proton decay, especially in the 'clean' channels with a charged lepton and a neutral meson in the final state.

The Economic Implications of Korean Unification

National Research Council Canada - National Science Library

Schmitz, Jonathan

2002-01-01

.... To lessen this burden, South Korea will need to initiate policy reforms that can ease the financial stress and repercussions of unification and create an integrated economic community with North Korea...

Lepton flavor changing processes and CP violation in the 331 model

Energy Technology Data Exchange (ETDEWEB)

Liu, J T [Texas A and M Univ., College Station, TX (United States). Center for Theoretical Physics; Ng, D

1994-01-01

By extending the electroweak gauge group to SU(3){sub L}x U(1){sub y}, the 331 model incorporates dilepton gauge bosons Y which do not respect individual lepton family number. We point out that, in addition to family diagonal couplings such as Y-e-e that change lepton family number by two units, dileptons may also have family nondiagonal couplings such as Y-{mu}-e. The latter coupling violates lepton family number by a single unit and manifests itself via lepton flavor changing decays such as {mu} {yields} e{gamma} and p --+ c-1. The family non-diagonal interaction can be CP violating and typically generates extremely large leptonic electric dipole moments. We demonstrate a natural mechanism for eliminating both single unit lepton flavor violation and large leptonic CP violation. Although we focus on the 331 model, our results are applicable to other dilepton models as well, including SU(15) grand unification. (author). 41 refs., 2 figs.

Gauge-Higgs Unification Models in Six Dimensions with S2/Z2 Extra Space and GUT Gauge Symmetry

Directory of Open Access Journals (Sweden)

Cheng-Wei Chiang

2012-01-01

Full Text Available We review gauge-Higgs unification models based on gauge theories defined on six-dimensional spacetime with S2/Z2 topology in the extra spatial dimensions. Nontrivial boundary conditions are imposed on the extra S2/Z2 space. This review considers two scenarios for constructing a four-dimensional theory from the six-dimensional model. One scheme utilizes the SO(12 gauge symmetry with a special symmetry condition imposed on the gauge field, whereas the other employs the E6 gauge symmetry without requiring the additional symmetry condition. Both models lead to a standard model-like gauge theory with the SU(3×SU(2L×U(1Y(×U(12 symmetry and SM fermions in four dimensions. The Higgs sector of the model is also analyzed. The electroweak symmetry breaking can be realized, and the weak gauge boson and Higgs boson masses are obtained.

Higgsless grand unified theory breaking and trinification

International Nuclear Information System (INIS)

Carone, Christopher D.; Conroy, Justin M.

2004-01-01

Boundary conditions on an extra dimensional interval can be chosen to break bulk gauge symmetries and to reduce the rank of the gauge group. We consider this mechanism in models with gauge trinification. We determine the boundary conditions necessary to break the trinified gauge group directly down to that of the standard model. Working in an effective theory for the gauge-symmetry-breaking parameters on a boundary, we examine the limit in which the grand-unified theory-breaking-sector is Higgsless and show how one may obtain the low-energy particle content of the minimal supersymmetric standard model. We find that gauge unification is preserved in this scenario, and that the differential gauge coupling running is logarithmic above the scale of compactification. We compare the phenomenology of our model to that of four dimensional 'trinified' theories

From chaos to unification: U theory vs. M theory

International Nuclear Information System (INIS)

Ye, Fred Y.

2009-01-01

A unified physical theory called U theory, that is different from M theory, is defined and characterized. U theory, which includes spinor and twistor theory, loop quantum gravity, causal dynamical triangulations, E-infinity unification theory, and Clifford-Finslerian unifications, is based on physical tradition and experimental foundations. In contrast, M theory pays more attention to mathematical forms. While M theory is characterized by supersymmetry string theory, U theory is characterized by non-supersymmetry unified field theory.

How supersymmetry naturally suppresses Higgs-boson-mediated baryon-number violation in SU/sub c/(4) x SU/sub L/(2) x SU/sub R/(2) and SO(10)

International Nuclear Information System (INIS)

Gipson, J.M.; Marshak, R.E.

1984-01-01

The supersymmetric versions of the left-right-symmetric SU/sub C/(4) x SU/sub L/(2) x SU/sub R/(2) Pati-Salam theory and the grand unified SO(10) theory are studied. In the minimal versions of these models the requirement of soft or spontaneous breaking of supersymmetry, together with renormalizibility, leads to an accidental global U(1) symmetry which leads to baryon-number conservation. A necessary condition for this symmetry to be broken is the existence of fields which are antisymmetric in at least two SU/sub C/(4) indices. The introduction of such fields may allow for observable neutron oscillation

The Unification of Private International Law

Directory of Open Access Journals (Sweden)

Emira Kazazi

2015-07-01

Full Text Available Civil and the common law approaching Europe is no longer a “future project”, but more and more rather a present attempt (Kötz, 2003 – 2004. In this prism, concentrating on the European International Private Law within the space of mixed jurisdictions, it may seem surprising in light of the attempts to create a new European ius commune. But is it possible that a unification of the material law may sign the start of the end of the European conflicts of laws? Last but not the least private international law is not just a choice of law. The unification of the private law, in its definition as a concept, does not influence two of the three pillars of the private international law: respectively, that of the jurisdiction and recognition as well as implementation of foreign decisions.

El 15-M como discurso contrahegemónico

Directory of Open Access Journals (Sweden)

Iñigo Errejón Galván

2011-12-01

Full Text Available El movimiento 15-M ha sido una irrupción inesperada en el panorama político español, que ha conseguido, desde su nacimiento, una enorme atención mediática y marcar en gran medida la agenda política española. En este artículo se defiende que una parte fundamental de su éxito político se debe a su capacidad de alterar las posiciones políticas dadas y generar una nueva identidad, los así llamados “indignados”, que suscitan lealtades relativamente transversales y reordenan el campo político español. Para ello, se analizará el discurso fundamental del 15-M desde los presupuestos y con las herramientas de la Teoría del Discurso y la Hegemonía. Se caracterizarán a grandes rasgos las principales operaciones de generación de sentido que constituyen a los “indignados” y se adelantarán algunas hipótesis sobre los escenarios de futuro.

[Theory of elementary particles studies in weak interaction and grand unification and studies in accelerator design

International Nuclear Information System (INIS)

1991-01-01

This report discusses research in high energy physics on the following topics: rare b decays; flavor changing top decays;neutrino physics; standard model; cp violation; heavy ion collisions; electron-positron interactions; electron-hadron interactions; hadron-hadron interactions; deep inelastic scattering; and grand unified models

La masa de los grandes impactores

Science.gov (United States)

Parisi, M. G.; Brunini, A.

Los planetas han sido formados fundamentalmente acretando masa a través de colisiones con planetesimales sólidos. La masa más grande de la distribución de planetesimales y las masas máxima y mínima de los impactores, han sido calculadas usando los valores actuales del período y de la inclinación de los planetas (Lissauer & Safronov 1991; Parisi & Brunini 1996). Recientes investigaciones han mostrado, que las órbitas de los planetas gigantes no han sufrido variaciones con el tiempo, siendo su movimiento regular durante su evolución a partir de la finalización de la etapa de acreción (Laskar 1990, 1994). Por lo tanto, la eccentricidad actual de los planetas gigantes se puede utilizar para imponer una cota máxima a las masas y velocidades orbitales de los grandes impactores. Mediante un simple modelo dinámico, y considerando lo arriba mencionado, obtenemos la cota superior para la masa del planetesimal más grande que impactó a cada planeta gigante al final de su etapa de acreción. El resultado más importante de este trabajo es la estimación de la masa máxima permitida para impactar a Júpiter, la cúal es ~ 1.136 × 10 -1, siendo en el caso de Neptuno ~ 3.99 × 10 -2 (expresada en unidades de la masa final de cada planeta). Además, fue posible obtener la velocidad orbital máxima permitida para los impactores como una función de su masa, para cada planeta. Las cotas obtenidas para la masa y velocidad de los impactores de Saturno y Urano (en unidades de la masa y velocidad final de cada planeta respectivamente) son casi las mismas que las obtenidas para Júpiter debido a que estos tres planetas poseen similar eccentricidad actual. Nuestros resultados están en buen acuerdo con los obtenidos por Lissauer & Safronov (1991). Estas cotas podrían ser utilizadas para obtener la distribución de planetesimales en el Sistema Solar primitivo.

Gauge coupling unification in six dimensions

Energy Technology Data Exchange (ETDEWEB)

Lee, H.M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[Carnegie-Mellon Univ., Pittsburgh, PA (United States). Dept. of Physics

2006-11-15

We compute the one-loop gauge couplings in six-dimensional non-Abelian gauge theories on the T{sup 2}/Z{sub 2} orbifold with general GUT breaking boundary conditions. For concreteness, we apply the obtained general formulae to the gauge coupling running in a 6D SO(10) orbifold GUT where the GUT group is broken down to the standard model gauge group up to an extra U(1). We find that the one-loop corrections depend on the parity matrices encoding the orbifold boundary conditions as well as the volume and shape moduli of extra dimensions. When the U(1) is broken by the VEV of bulk singlets, the accompanying extra color triplets also affect the unification of the gauge couplings. In this case, the B-L breaking scale is closely linked to the compactification scales for maintaining a success of the gauge coupling unification. (orig.)

M theory: a possible unification of physics laws

International Nuclear Information System (INIS)

Fernandes, Alexandre da Silva; Silva, Diego Oliveira Nolasco da; Sousa, Claudio Manoel Gomes de

2011-01-01

Full text: Physics has two pillars which are mutually incompatible: quantum field theory and general relativity theory. Throughout its history, various unifications have been made, and in attempts to have a better understanding of the birth and formation of the Universe is also necessary to unify these pillars. This unification may require 11 dimensions, and 6 of them are compressed so that it cannot be seen with existing instruments. These dimensions are the spaces in which the strings vibrate, and each mode of vibration corresponds to a particle. The last dimension shows that the universe is a brane, it is in full motion in the multiverse and the collision of two branes can answer the biggest problem of cosmology: what was the Big Bang? Black holes can be explained using a theory that contains gravity and quantum mechanics. The theory is still being developed, some problems are being solved and the main one is the experimental problem, because it requires energy levels that are not yet achieved by current particle accelerators. This work presents M theory as a possibility of unification between the micro and macro, which maybe leading us to the theory of everything. (author)

M theory: a possible unification of physics laws

Energy Technology Data Exchange (ETDEWEB)

Fernandes, Alexandre da Silva; Silva, Diego Oliveira Nolasco da; Sousa, Claudio Manoel Gomes de [Universidade Catolica de Brasilia (UCB), DF (Brazil)

2011-07-01

Full text: Physics has two pillars which are mutually incompatible: quantum field theory and general relativity theory. Throughout its history, various unifications have been made, and in attempts to have a better understanding of the birth and formation of the Universe is also necessary to unify these pillars. This unification may require 11 dimensions, and 6 of them are compressed so that it cannot be seen with existing instruments. These dimensions are the spaces in which the strings vibrate, and each mode of vibration corresponds to a particle. The last dimension shows that the universe is a brane, it is in full motion in the multiverse and the collision of two branes can answer the biggest problem of cosmology: what was the Big Bang? Black holes can be explained using a theory that contains gravity and quantum mechanics. The theory is still being developed, some problems are being solved and the main one is the experimental problem, because it requires energy levels that are not yet achieved by current particle accelerators. This work presents M theory as a possibility of unification between the micro and macro, which maybe leading us to the theory of everything. (author)

Soft CP violation and the global matter-antimatter symmetry of the universe

Science.gov (United States)

Senjanovic, G.; Stecker, F. W.

1980-01-01

Scenarios for baryon production are considered within the context of SU(5) and SO(10) grand unified theories where CP violation arises spontaneously. The spontaneous CP symmetry breaking then results in a matter-antimatter domain structure in the universe. Two possible, distinct types of theories of soft CP violation are defined. In the first type the CP nonconservation originates only from the breaking of SU(2) sub L X U(1) symmetry, and in the second type, even at the unification temperature scale, CP violation can emerge as a result of symmetry breaking by the vacuum expectation values of the superheavy Higgs sector scalars.

Squark and slepton mass relations in grand unified theories

International Nuclear Information System (INIS)

Cheng, H.; Hall, L.J.

1995-01-01

In the minimal supersymmetric standard model, assuming universal scalar masses at large energies, there are four intragenerational relations between the masses of the squarks and sleptons for each light generation. In this paper we study the scalar mass relations which follow only from the assumption that at large energies there is a grand unified theory which leads to a significant prediction of the weak mixing angle. Two new intragenerational mass relations for each of the light generations are derived. In addition, a third mass relation is found which relates the Higgs boson masses, the masses of the third generation scalars, and the masses of the scalars of the lighter generations. Verification of a fourth mass relation, involving only the charged slepton masses, provides a signal for SO(10) unification

Model-based object classification using unification grammars and abstract representations

Science.gov (United States)

Liburdy, Kathleen A.; Schalkoff, Robert J.

1993-04-01

The design and implementation of a high level computer vision system which performs object classification is described. General object labelling and functional analysis require models of classes which display a wide range of geometric variations. A large representational gap exists between abstract criteria such as `graspable' and current geometric image descriptions. The vision system developed and described in this work addresses this problem and implements solutions based on a fusion of semantics, unification, and formal language theory. Object models are represented using unification grammars, which provide a framework for the integration of structure and semantics. A methodology for the derivation of symbolic image descriptions capable of interacting with the grammar-based models is described and implemented. A unification-based parser developed for this system achieves object classification by determining if the symbolic image description can be unified with the abstract criteria of an object model. Future research directions are indicated.

Gauge unification of fundamental forces

International Nuclear Information System (INIS)

Salam, A.

1980-02-01

After having reviewed briefly the last twenty years' progress in the theory of unification, with the twin aspects of development of a gauge theory of basic interactions linked with internal symmetry and the spontaneous breaking of these symmetries, the Nobel prize winners have summarized the present situation and the immediate problems. At the end, an extrapolation of the future is also given

Similarity-Based Unification: A Multi-Adjoint Approach

Czech Academy of Sciences Publication Activity Database

Medina, J.; Ojeda-Aciego, M.; Vojtáš, Peter

2004-01-01

Roč. 146, č. 1 (2004), s. 43-62 ISSN 0165-0114 Source of funding: V - iné verejné zdroje Keywords : similarity * fuzzy unification Subject RIV: BA - General Mathematics Impact factor: 0.734, year: 2004

Gauge unification of basic forces particularly of gravitation with strong interactions

International Nuclear Information System (INIS)

Salam, A.

1977-01-01

Corresponding to the two known types of gauge theories, Yang-Mills with spin-one mediating particles and Einstein Weyl with spin-two mediating particles, it is speculated that two distinct gauge unifications of the basic forces appear to be taking place. One is the familiar Yang-Mills unification of weak and electromagnetic forces with the strong. The second is the less familiar gauge unification of gravitation with spin-two tensor-dominated aspects of strong interactions. It is proposed that there are strongly interacting spin-two strong gravitons obeying Einstein's equations, and their existence gives a clue to an understanding of the (partial) confinement of quarks, as well as of the concept of hadronic temperature, through the use of Schwarzschild de-Sitter-like partially confining solitonic solutions of the strong gravity Einstein equation

Discovery of proton decay: A must for theory, a challenge for experiment

Science.gov (United States)

Pati, Jogesh C.

2000-08-01

It is noted that, but for one missing piece—proton decay—the evidence in support of grand unification is now strong. It includes: (i) the observed family-structure, (ii) the meeting of the gauge couplings, (iii) neutrino-oscillations, (iv) the intricate pattern of the masses and mixings of all fermions, including the neutrinos, and (v) the need for B-L as a generator, to implement baryogenesis. Taken together, these not only favor grand unification but in fact select out a particular route to such unification, based on the ideas of supersymmetry, SU(4)-color and left-right symmetry. Thus they point to the relevance of an effective string-unified G(224) or SO(10)-symmetry. 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 pays special attention to its dependence on the fermion masses, including the superheavy Majorana masses of the right-handed neutrinos. The study shows that a conservative upper limit on the proton lifetime is about (1/2-1)×1034yrs, with ν¯K+ being the dominant decay mode, and as a distinctive feature, μ+K0 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.

Neutrino masses in the SU(5) x (lower case x) SU(5)' mirror symmetric model

International Nuclear Information System (INIS)

Collie, M.; Foot, R.

1998-02-01

Motivated by the atmospheric and solar neutrino anomalies, we study neutrino masses in a parity invariant SU(5) x SU(5)' grand unified model. Two distinct ways of incorporating neutrino masses into this model are envisaged. One way involves adding a gauge singlet fermion to each generation. The other way, is to extend the scalar sector. This possibility suggests that photon - mirror photon kinetic mixing is non-zero since is generated radiatively. It is argued that the kinetic mixing is such models may well be close to the experimental limit

Luis de León (1527-1591 y su teoría de la justicia: aspectos principales de su doctrina

Directory of Open Access Journals (Sweden)

Sebastián Contreras

2014-04-01

Full Text Available Las investigaciones sobre Luis de León se han centrado, sobre todo, en su mística, narrativa y teoría literaria. En este trabajo, el autor intenta desarrollar los principales aspectos de su teoría jurídica. Al igual que otros grandes teólogos de la Escuela de Salamanca, también León ha estudiado el problema de la naturaleza de la ley humana y su vinculación con el derecho natural. Éste es, justamente, el tema del siguiente trabajo.

Asymptotically Safe Grand Unification

DEFF Research Database (Denmark)

Bajc, Borut; Sannino, Francesco

2016-01-01

the inclusion of gravity, by generating an interacting ultraviolet fixed point, similar to the one recently discovered in non-supersymmetric gauge-Yukawa theories. Employing a-maximization, a-theorem, unitarity bounds, as well as positivity of other central charges we nonperturbatively rule out this possibility...

Dynamical symmetry breakdown in SU(5) and SO(10)

International Nuclear Information System (INIS)

Shellard, R.C.

1983-09-01

Some restrictions imposed upon Grand Unified Theories by dynamical symmetry breakdown are examined. It is observed in particular, that theories with SU(5) as symmetry group, with 3 or more fermion families undergo dynamical symmetry breakdown, and some of the fermions will acquire mass at the Grand Unified scale. On the other hand, the SO(10) group, with 3 families is free from this problem. (Author) [pt

Unification and new particles at the LHC

Energy Technology Data Exchange (ETDEWEB)

Arkani-Hamed, Nima; D’Agnolo, Raffaele Tito; Low, Matthew [School of Natural Sciences, Institute for Advanced Study,Einstein Drive, Princeton, NJ 08540 (United States); Pinner, David [Princeton Center for Theoretical Physics, Princeton University,Jadwin Hall, Princeton, NJ 08544 (United States)

2016-11-14

Precision gauge coupling unification is one of the primary quantitative successes of low energy or split supersymmetry. Preserving this success puts severe restrictions on possible matter and gauge sectors that might appear at collider-accessible energies. In this work we enumerate new gauge sectors which are compatible with unification, consisting of horizontal gauge groups acting on vector-like matter charged under the Standard Model. Interestingly, almost all of these theories are in the supersymmetric conformal window at high energies and confine quickly after the superpartners are decoupled. For a range of scalar masses compatible with both moderately tuned and minimally split supersymmetry, the confining dynamics happen at the multi-TeV scale, leading to a spectrum of multiple spin-0 and spin-1 resonances accessible to the LHC, with unusual quantum numbers and striking decay patterns.

Unification and new particles at the LHC

International Nuclear Information System (INIS)

Arkani-Hamed, Nima; D’Agnolo, Raffaele Tito; Low, Matthew; Pinner, David

2016-01-01

Precision gauge coupling unification is one of the primary quantitative successes of low energy or split supersymmetry. Preserving this success puts severe restrictions on possible matter and gauge sectors that might appear at collider-accessible energies. In this work we enumerate new gauge sectors which are compatible with unification, consisting of horizontal gauge groups acting on vector-like matter charged under the Standard Model. Interestingly, almost all of these theories are in the supersymmetric conformal window at high energies and confine quickly after the superpartners are decoupled. For a range of scalar masses compatible with both moderately tuned and minimally split supersymmetry, the confining dynamics happen at the multi-TeV scale, leading to a spectrum of multiple spin-0 and spin-1 resonances accessible to the LHC, with unusual quantum numbers and striking decay patterns.

The Super-GUT CMSSM Revisited

CERN Document Server

Ellis, John

2016-01-01

We revisit minimal supersymmetric SU(5) grand unification (GUT) models in which the soft supersymmetry-breaking parameters of the minimal supersymmetric Standard Model (MSSM) are universal at some input scale, $M_{in}$, above the supersymmetric gauge coupling unification scale, $M_{GUT}$. As in the constrained MSSM (CMSSM), we assume that the scalar masses and gaugino masses have common values, $m_0$ and $m_{1/2}$ respectively, at $M_{in}$, as do the trilinear soft supersymmetry-breaking parameters $A_0$. Going beyond previous studies of such a super-GUT CMSSM scenario, we explore the constraints imposed by the lower limit on the proton lifetime and the LHC measurement of the Higgs mass, $m_h$. We find regions of $m_0$, $m_{1/2}$, $A_0$ and the parameters of the SU(5) superpotential that are compatible with these and other phenomenological constraints such as the density of cold dark matter, which we assume to be provided by the lightest neutralino. Typically, these allowed regions appear for $m_0$ and $m_{1/...

Macroscopic constraints on string unification

International Nuclear Information System (INIS)

Taylor, T.R.

1989-03-01

The comparison of sting theory with experiment requires a huge extrapolation from the microscopic distances, of order of the Planck length, up to the macroscopic laboratory distances. The quantum effects give rise to large corrections to the macroscopic predictions of sting unification. I discus the model-independent constraints on the gravitational sector of string theory due to the inevitable existence of universal Fradkin-Tseytlin dilatons. 9 refs

Gauge hierarchy problem in grand unified theories

International Nuclear Information System (INIS)

Alhendi, H.A.A.

1982-01-01

In grand unification schemes, several mass scales are to be introduced, with some of them much larger than all the others, to cope with experimental observations, in which elementary particles of higher masses require higher energy to observe them than elementary particles of lower masses. There have been controversial arguments in the literature on such hierarchical scale structure, when radiative corrections are taken into account. It has been asserted that the gauge hierarchy depends on the choice of the subtraction point (in the classical field space), of the four-point function at zero external momentum. It also has been asserted that the gauge hierarchy problem whenever it is possible to be maintained in one sector of particles, it also is possible to be maintained in the other sectors. These two problems have been studied in a prototype model, namely an 0(3)-model with two triplets of real scalar Higgs fields. Our analysis shows that, within ordinary perturbation theory, none of these two problems is quite correct

Technical constraints for the GUT scale parameter

International Nuclear Information System (INIS)

Diosi, L.; Lukacs, B.; Paal, G.

1984-01-01

The influence of the grand unification scale on the thermal history of the early universe is discussed. Above M approx.= 6.8x10 15 GeV the irreversibilities seem to be too strong to ignore, and the usual calculations lose their validity. (author)

Supersymmetric SU(11), the invisible axion, and proton decay

International Nuclear Information System (INIS)

Alwis, S.P. de; Kim, J.E.

1981-09-01

We supersymmetrize the very attractive flavour unification model SU(11). As with other supersymmetric GUTs the gauge hierarchy problem is simplified, but we may also have observable (tausub(p) is approximately 10 33 yrs) proton decay. The required split multiplets are obtained by making the adjoint take a particular direction. Supersymmetry is broken softly at the TeV scale. There is a unique U(1)sub(A) symmetry, and hence there are no true Nambu-Goldstone bosons. The U(1)sub(A) is broken at the GUT scale and there result an invisible axion and neutrino masses. (author)

Constructing 5d orbifold grand unified theories from heterotic strings

International Nuclear Information System (INIS)

Kobayashi, Tatsuo; Raby, Stuart; Zhang Renjie

2004-01-01

A three-generation Pati-Salam model is constructed by compactifying the heterotic string on a particular T 6 /Z 6 Abelian symmetric orbifold with two discrete Wilson lines. The compactified space is taken to be the Lie algebra lattice G 2 -bar SU(3)-bar SO(4). When one dimension of the SO(4) lattice is large compared to the string scale, this model reproduces many features of a 5d SO(10) grand unified theory compactified on an S 1 /Z 2 orbifold. (Of course, with two large extra dimensions we can obtain a 6d SO(10) grand unified theory.) We identify the orbifold parities and other ingredients of the orbifold grand unified theories in the string model. Our construction provides a UV completion of orbifold grand unified theories, and gives new insights into both field theoretical and string theoretical constructions

Flipped and unflipped SU(5) as type IIA flux vacua

Energy Technology Data Exchange (ETDEWEB)

Chen Chingming [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States); Li Tianjun [Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854 (United States) and Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100080 (China)]. E-mail: tjli@physics.rutgers.edu; Nanopoulos, Dimitri V. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States); Astroparticle Physics Group, Houston Advanced Research Center (HARC), Mitchell Campus, Woodlands, TX 77381 (United States); Academy of Athens, Division of Natural Sciences, 28 Panepistimiou Avenue, Athens 10679 (Greece)

2006-09-04

On type IIA orientifolds with flux compactifications in supersymmetric AdS vacua, we for the first time construct SU(5) models with three anti-symmetric 10 representations and without symmetric 15 representations. We show that all the pairs of the anti-fundamental 5-bar and fundamental 5 representations can obtain GUT/string-scale vector-like masses after the additional gauge symmetry breaking via supersymmetry preserving Higgs mechanism. Then we have exact three 5-bar , and no other chiral exotic particles that are charged under SU(5) due to the non-Abelian anomaly free condition. Moreover, we can break the SU(5) gauge symmetry down to the SM gauge symmetry via D6-brane splitting, and solve the doublet-triplet splitting problem. Assuming that the extra one (or several) pair(s) of Higgs doublets and adjoint particles obtain GUT/string-scale masses via high-dimensional operators, we only have the MSSM in the observable sector below the GUT scale. Then the observed low energy gauge couplings can be generated via RGE running if we choose the suitable grand unified gauge coupling by adjusting the string scale. Furthermore, we construct the first flipped SU(5) model with exact three 10, and the first flipped SU(5) model in which all the Yukawa couplings are allowed by the global U(1) symmetries.

Neutrino masses in the flipped SU(5) x U(1) and the SU(4) x O(4) GUT models

Energy Technology Data Exchange (ETDEWEB)

Ranfone, S.; Papageorgiu, E.

1992-03-01

We classify the different neutrino-mass pattern arising in string-inspired Grand Universal Theory (GUT) and supersymmetric GUT models based on the flipped SU(5)xU(1) and the SU(4)xO(4) gauge groups. Phenomenologically interesting spectra are obtained through the interplay of the two seesaw mechanisms present, with typical neutrino masses {approx}10{sup -3} eV in the supersymmetric GUT models and of order 0.1 - 10 KeV in the ordinary GUTs. (author).

Warped unification, proton stability, and dark matter.

Science.gov (United States)

Agashe, Kaustubh; Servant, Géraldine

2004-12-03

We show that solving the problem of baryon-number violation in nonsupersymmetric grand unified theories (GUT's) in warped higher-dimensional spacetime can lead to a stable Kaluza-Klein particle. This exotic particle has gauge quantum numbers of a right-handed neutrino, but carries fractional baryon number and is related to the top quark within the higher-dimensional GUT. A combination of baryon number and SU(3) color ensures its stability. Its relic density can easily be of the right value for masses in the 10 GeV-few TeV range. An exciting aspect of these models is that the entire parameter space will be tested at near future dark matter direct detection experiments. Other exotic GUT partners of the top quark are also light and can be produced at high energy colliders with distinctive signatures.

Testing the AGN Unification Model in the Infrared

International Nuclear Information System (INIS)

Ramos Almeida, C; Levenson, N A; Radomski, J T; Alonso-Herrero, A; Asensio Ramos, A; Rodríguez Espinosa, J M; Pérez García, A M; Packham, C; Mason, R; Díaz-Santos, T

2012-01-01

We present near-to-mid-infrared spectral energy distributions (SEDs) for 21 Seyfert galaxies, using subarcsecond resolution imaging data. Our aim is to compare the properties Seyfert 1 (Sy1) and Seyfert 2 (Sy2) tori using clumpy torus models and a Bayesian approach to fit the infrared (IR) nuclear SEDs. These dusty tori have physical sizes smaller than 6 pc radius, as derived from our fits. Active galactic nuclei (AGN) unification schemes account for a variety of observational differences in terms of viewing geometry. However, we find evidence that strong unification may not hold, and that the immediate dusty surroundings of Sy1 and Sy2 nuclei are intrinsically different. The Type 2 tori studied here are broader, have more clumps, and these clumps have lower optical depths than those of Type 1 tori. The larger the covering factor of the torus, the smaller the probability of having direct view of the AGN, and vice-versa. In our sample, Sy2 tori have larger covering factors (C T = 0.95±0.02) and smaller escape probabilities than those of Sy1 (C T = 0.5±0.1). Thus, on the basis of the results presented here, the classification of a Seyfert galaxy may depend more on the intrinsic properties of the torus rather than on its mere inclination, in contradiction with the simplest unification model.

Third-generation effects on fermion mass predictions in supersymmetric grand unified theories

International Nuclear Information System (INIS)

Naculich, S.G.

1993-01-01

Relations among fermion masses and mixing angles at the scale of grand unification are modified at lower energies by renormalization group running induced by gauge and Yukawa couplings. In supersymmetric theories, the b quark and τ lepton Yukawa couplings, as well as the t quark coupling, may cause significant running if tanβ, the ratio of Higgs field expectation values, is large. We present approximate analytic expressions for the scaling factors for fermion masses and CKM matrix elements induced by all three third generation Yukawa couplings. We then determine how running caused by the third generation of fermions affects the predictions arising from three possible forms for the Yukawa coupling matrices at the GUT scale: the Georgi-Jarlskog, Giudice, and Fritzsch textures

Neutrino masses in flipped SU(5)

Energy Technology Data Exchange (ETDEWEB)

Abel, S.A. (Bristol Univ. (UK). H.H. Wills Physics Lab.)

1990-01-04

It is demonstrated that the, recently proposed, SU(5)xU(1) unification scheme is one of only a small number of the current candidates that allows, in its parameter space, the possibility of heavy neutrinos. This is due to the fact that the usual GIM suppression mechanism does not operate, leading to fast decays of heavy tau neutrinos of the form {nu}{yields}{nu}{gamma}, with an estimated lifetime of O(1 yr) for a tau neutrino mass of 1 MeV. Using well known cosmological arguments, based on the observed 3 K background radiation, the mass of the electron neutrino is constrained to be either greater than O(1 eV), or less than the usual limit of O(10{sup -2} eV). (orig.).

A supersymmetric flipped SU(5) intersecting brane world

Energy Technology Data Exchange (ETDEWEB)

Chen, C.-M. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States)]. E-mail: cchen@physics.tamu.edu; Kraniotis, G.V. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States)]. E-mail: kraniotis@physics.tamu.edu; Mayes, V.E. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States)]. E-mail: eric@physics.tamu.edu (and others)

2005-03-31

We construct an N=1 supersymmetric three-family flipped SU(5) model from type IIA orientifolds on T{sup 6}/(Z{sub 2}xZ{sub 2}) with D6-branes intersecting at general angles. The spectrum contains a complete grand unified and electroweak Higgs sector. In addition, it contains extra exotic matter both in bi-fundamental and vector-like representations as well as two copies of matter in the symmetric representation of SU(5)

Constraints on grand unified superstring theories

International Nuclear Information System (INIS)

Ellis, J.; Lopez, J.L.; Nanopoulos, D.V.; Houston Advanced Research Center

1990-01-01

We evaluate some constraints on the construction of grand unified superstring theories (GUSTs) using higher level Kac-Moody algebras on the world-sheet. In the most general formulation of the heterotic string in four dimensions, an analysis of the basic GUST model-building constraints, including a realistic hidden gauge group, reveals that there are no E 6 models and any SO(10) models can only exist at level-5. Also, any such SU(5) models can exist only for levels 4≤k≤19. These SO(10) and SU(5) models risk having many large, massless, phenomenologically troublesome representations. We also show that with a suitable hidden sector gauge group, it is possible to avoid free light fractionally charged particles, which are endemic to string derived models. We list all such groups and their representations for the flipped SU(5)xU(1) model. We conclude that a sufficiently binding hidden sector gauge group becomes a basic model-building constraint. (orig.)

Explanatory Unification by Proofs in School Mathematics

Science.gov (United States)

Komatsu, Kotaro; Fujita, Taro; Jones, Keith; Naoki, Sue

2018-01-01

Kitcher's idea of 'explanatory unification', while originally proposed in the philosophy of science, may also be relevant to mathematics education, as a way of enhancing student thinking and achieving classroom activity that is closer to authentic mathematical practice. There is, however, no mathematics education research treating explanatory…

Chiral symmetry and eta, eta' → 3π decays. Grand unified theories

International Nuclear Information System (INIS)

Roiesnel, C.

1982-11-01

Two different topics related to symmetry breaking are discussed. First the eta, eta' → 3π decays are presented. The amplitudes eta, eta' → 3π are calculated with the square root threshold singularity induced by the strong pion-pion final state interaction properly taken into account. It is shown that the eta' → 3π decay rate depends sensitively upon an improved treatment of the pseudoscalar nonet mass matrix. Then symmetry-breaking effects in grand unified theories are discussed. The threshold effects in a spontaneously broken gauge theory are studied. In particular a computation of the symmetry-breaking effects in the SU(5) grand unified theory including those of the breaking of SU(2)xU(1) is presented. As an application a precise value of the superheavy gauge boson mass Mx is given. It is possible in SU(5) to define a natural effective weak angle theta w(μ) for any scale μ, below as well as above Mw, and the predicted curve for sin 2 theta w(μ) is given [fr

N-anti N oscillation in SO(10) and SU(6) supersymmetric grand unified models

International Nuclear Information System (INIS)

Fujimoto, Y.; Zhiyong, Z.

1982-06-01

N-anti N oscillation in SO(10) and SU(6) S.G.U.M. is considered. We find a new type of diagram leading to a faster oscillation rate than in non-supersymmetric case. It is also noted that in SO(10) S.G.U.M. with intermediate SU(4)sub(C)xSU(2)sub(L)xSU(2)sub(R) symmetry N-anti N oscillation would be highly suppressed, which may not necessarily be the case for SU(6) S.G.U.M. (author)

Families in the nonperturbative unification scheme

Energy Technology Data Exchange (ETDEWEB)

Kapetanakis, D. (National Research Centre for the Physical Sciences Democritos, Athens (Greece)); Theisen, S. (European Organization for Nuclear Research, Geneva (Switzerland)); Zoupanos, G. (Ethnikon Metsovion Polytechneion, Athens (Greece). Dept. of Physics)

1989-10-12

Within the nonperturbative unification framework of Maiani, Parisi and Petronzio, we examine the influence of the number of fermion and Higgs families, when they are grouped in representations of horizontal family groups, on the low energy couplings of the standard model. In this way we find a number of new phenomenologically acceptable solutions for the standard model's low energy couplings. (orig.).

Families in the nonperturbative unification scheme

International Nuclear Information System (INIS)

Kapetanakis, D.; Theisen, S.; Zoupanos, G.

1989-01-01

Within the nonperturbative unification framework of Maiani, Parisi and Petronzio, we examine the influence of the number of fermion and Higgs families, when they are grouped in representations of horizontal family groups, on the low energy couplings of the standard model. In this way we find a number of new phenomenologically acceptable solutions for the standard model's low energy couplings. (orig.)

Authenticity and Unification in Quechua Language Planning.

Science.gov (United States)

Hornberger, Nancy H.; King, Kendall

1998-01-01

Examines the potentially problematic tension between the goals of authenticity and unification in Quechua-language planning. One case study examines the orthographic debate that arose in Peru, and the second case study concerns two indigenous communities in Saraguro in the Southern Ecuadorian highlands where Spanish predominates but two Quichua…

Discovery of proton decay: A must for theory, a challenge for experiment

International Nuclear Information System (INIS)

Pati, Jogesh C.

2000-01-01

It is noted that, but for one missing piece--proton decay--the evidence in support of grand unification is now strong. It includes: (i) the observed family-structure, (ii) the meeting of the gauge couplings, (iii) neutrino-oscillations, (iv) the intricate pattern of the masses and mixings of all fermions, including the neutrinos, and (v) the need for B-L as a generator, to implement baryogenesis. Taken together, these not only favor grand unification but in fact select out a particular route to such unification, based on the ideas of supersymmetry, SU(4)-color and left-right symmetry. Thus they point to the relevance of an effective string-unified G(224) or SO(10)-symmetry. 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 pays special attention to its dependence on the fermion masses, including the superheavy Majorana masses of the right-handed neutrinos. The study shows that a conservative upper limit on the proton lifetime is about (1/2-1)x10 34 yrs, with ν(bar sign)K + being the dominant decay mode, and as a distinctive feature, μ + K 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

Fermion unification model based on the intrinsic SU(8 symmetry of a generalized Dirac equation

Directory of Open Access Journals (Sweden)

Eckart eMarsch

2015-10-01

Full Text Available A natural generalization of the original Dirac spinor into a multi-component spinor is achieved, which corresponds to the single lepton and the three quarks of the first family of the standard model of elementary particle physics. Different fermions result from similarity transformations of the Dirac equation, but apparently there can be no more fermions according to the maximal multiplicity revealed in this study. Rotations in the fermion state space are achieved by the unitary generators of the U(1 and the SU(3 groups, corresponding to quantum electrodynamics (QED based on electric charge and chromodynamics (QCD based on colour charge. In addition to hypercharge the dual degree of freedom of hyperspin emerges, which occurs due to the duplicity implied by the two related (Weyl and Dirac representations of the Dirac equation. This yields the SU(2 symmetry of the weak interaction, which can be married to U(1 to generate the unified electroweak interaction as in the standard model. Therefore, the symmetry group encompassing all the three groups mentioned above is SU(8, which can accommodate and unify the observed eight basic stable fermions.

Predictions of the Higgs mass and the weak mixing angle in the 6D gauge-Higgs unification

International Nuclear Information System (INIS)

Hasegawa, Kouhei; Lim, Chong-Sa; Maru, Nobuhito

2016-01-01

In the gauge-Higgs unification with multiple extra spaces, the Higgs self-coupling is on the order of g 2 and the Higgs boson is predicted to be light, being consistent with the LHC results. When the gauge group is simple, the weak mixing angle is also predictable. We address a question on whether there exists a model of gauge-Higgs unification in six-dimensional space-time, which successfully predicts the mass ratios of the Higgs boson and weak gauge bosons. First, using a useful formula, we give a general argument on the condition for obtaining a realistic prediction of the weak mixing angle sin 2 θ W = 1/4, and find that triplet and sextet representations of the minimal SU(3) gauge group lead to the realistic prediction. Concerning the Higgs mass, we notice that, in the models with one Higgs doublet, the predicted Higgs mass is always the same: M H = 2M W . However, by extending our discussion to the models with two Higgs doublets, the situation changes: we obtain an interesting prediction M H ≤ 2M W at the leading order of the perturbation. Thus, it is possible to recover the observed Higgs mass, 125 GeV, for a suitable choice of the parameter. The situation is in clear contrast to the case of the minimal supersymmetric standard model, where M H ≤ M Z at the classical level and the predicted Higgs mass cannot recover the observed value. (author)

NÃveis de isoleucina digestÃvel para suÃnos machos castrados dos 15 aos 30 kg

OpenAIRE

Doglas Batista Lazzeri

2011-01-01

Com o objetivo de determinar a exigÃncia de isoleucina digestÃvel para suÃnos machos castrados dos 15 aos 30 kg de peso vivo, foram realizados dois experimentos, um de digestibilidade e outro de desempenho. Para determinar o coeficiente de digestibilidade ileal dos aminoÃcidos da raÃÃo basal, foram utilizados 10 suÃnos, machos castrados, mestiÃos, com peso mÃdio inicial de 15,00Â0,27 kg, alojados individualmente em gaiolas de metabolismo, em um delineamento inteiramente ao acaso, com dois tra...

Introduction to Grand Unified Theories. 12

International Nuclear Information System (INIS)

Wali, K.C.

1989-01-01

This chapter presents an introduction into Grand Unified Theories. After a discussion of the general features to be expected in any such theory, and of the motivations for them, a detailed presentation of SU(5) theory is given. The group structures, particle multiplets, gauge and Higgs bosons are explained. The two stages of spontaneous symmetry breaking via the Higgs model, are calculated individually and in combination. Fermion mass matrices and relations between quark and lepton masses are derived. predictions of SU(5) theory, calculated using renormalization group methods, are derived. The chapter ends with discussions that bring together particle physics and cosmology, including the baryon asymmetry problem, phase transitions in the very early universe, and singularities like domain walls, vortex lines and monopoles. (author). 9 refs.; 4 figs.; 5 tabs

Nuove prospettive storiografiche sulla Grande guerra: violenze, traumi, esperienze

Directory of Open Access Journals (Sweden)

Marco Bizzocchi

2014-03-01

Full Text Available Il testo propone, attraverso l’analisi delle recensioni pubblicate sulla rivista internazionale “First World War Studies”, una rassegna su alcuni recenti studi storici sulla Prima guerra mondiale. Dopo la svolta degli anni Settanta-Ottanta, la storiografia sta continuando ad approfondire in particolare il tema dei risvolti sociali e culturali della Grande guerra.

Unification types of housing during Sochi Olympics

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Aleksandr A. Babaev

2011-05-01

Full Text Available In the article the statement of the unification problem of housing accommodation of participants, spectators, staff, committee during the Winter Olympics in Sochi. We give a mathematical formalization of the problem, where the unknown variables are theelements of the combination of types of accommodation sorted by the level of comfortand representation.

Flipped SU(5) from Z{sub 12-I} orbifold with Wilson line

Energy Technology Data Exchange (ETDEWEB)

Kim, Jihn E. [Department of Physics and Astronomy, and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)]. E-mail: jekim@phyp.snu.ac.kr; Kyae, Bumseok [School of Physics, Korea Institute for Advanced Study, 207-43 Cheongryangri-dong, Dongdaemun-gu, Seoul 130-722 (Korea, Republic of)]. E-mail: bkyae@kias.re.kr

2007-05-14

We construct a three family flipped SU(5) model from the heterotic string theory compactified on the Z{sub 12-I} orbifold with one Wilson line. The gauge group is SU(5)xU(1){sub X}xU(1){sup 3}x[SU(2)xSO(10)xU(1){sup 2}]{sup '}. This model does not derive any non-Abelian group except SU(5) from E{sub 8}, which is possible only for two cases in case of one shift V, one in Z{sub 12-I} and the other in Z{sub 12-II}. We present all possible Yukawa couplings. We place the third quark family in the twisted sectors and two light quark families in the untwisted sector. From the Yukawa couplings, the model provides the R-parity, the doublet-triplet splitting, and one pair of Higgs doublets. It is also shown that quark and lepton mixings are possible. So far we have not encountered a serious phenomenological problem. There exist vector-like flavor SU(5) exotics (including Q{sub em}=+/-16 color exotics and Q{sub em}=+/-12 electromagnetic exotics) and SU(5) vector-like singlet exotics with Q{sub em}=+/-12 which can be removed near the GUT scale. In this model, sin{sup 2}{theta}{sub W}{sup 0}=38 at the full unification scale.

SU(3)_C× SU(2)_L× U(1)_Y( × U(1)_X ) as a symmetry of division algebraic ladder operators

Science.gov (United States)

Furey, C.

2018-05-01

We demonstrate a model which captures certain attractive features of SU(5) theory, while providing a possible escape from proton decay. In this paper we show how ladder operators arise from the division algebras R, C, H, and O. From the SU( n) symmetry of these ladder operators, we then demonstrate a model which has much structural similarity to Georgi and Glashow's SU(5) grand unified theory. However, in this case, the transitions leading to proton decay are expected to be blocked, given that they coincide with presumably forbidden transformations which would incorrectly mix distinct algebraic actions. As a result, we find that we are left with G_{sm} = SU(3)_C× SU(2)_L× U(1)_Y / Z_6. Finally, we point out that if U( n) ladder symmetries are used in place of SU( n), it may then be possible to find this same G_{sm}=SU(3)_C× SU(2)_L× U(1)_Y / Z_6, together with an extra U(1)_X symmetry, related to B-L.

Higgs Inflation, Reheating and Gravitino Production in No-Scale Supersymmetric GUTs

CERN Document Server

Ellis, John; Xianyu, Zhong-Zhi

2016-08-30

We extend our previous study of supersymmetric Higgs inflation in the context of no-scale supergravity and grand unification, to include models based on the flipped SU(5) and the Pati-Salam group. Like the previous SU(5) GUT model, these yield a class of inflation models whose inflation predictions interpolate between those of the quadratic chaotic inflation and Starobinsky-like inflation, while also avoiding tension with proton decay limits. We further analyse the reheating process in these models, and derive the number of $e$-folds, which is independent of the reheating temperature. We derive the corresponding predictions for the scalar tilt and the tensor-to-scalar ratio in cosmic microwave background perturbations, and also discuss gravitino production following inflation.

Higgs inflation, reheating and gravitino production in no-scale Supersymmetric GUTs

Energy Technology Data Exchange (ETDEWEB)

Ellis, John [Theoretical Particle Physics and Cosmology Group,Department of Physics, King’s College London,London WC2R 2LS (United Kingdom); Theoretical Physics Department, CERN,CH-1211 Geneva 23 (Switzerland); He, Hong-Jian [Institute of Modern Physics and Center for High Energy Physics, Tsinghua University,Beijing 100084 (China); Center for High Energy Physics, Peking University,Beijing 100871 (China); Xianyu, Zhong-Zhi [Center of Mathematical Sciences and Applications andDepartment of Physics, Harvard University,Massachusetts 02138 (United States)

2016-08-30

We extend our previous study of supersymmetric Higgs inflation in the context of no-scale supergravity and grand unification, to include models based on the flipped SU(5) and the Pati-Salam group. Like the previous SU(5) GUT model, these yield a class of inflation models whose inflation predictions interpolate between those of the quadratic chaotic inflation and Starobinsky-like inflation, while avoiding tension with proton decay limits. We further analyse the reheating process in these models, and derive the number of e-folds, which is independent of the reheating temperature. We derive the corresponding predictions for the scalar tilt and the tensor-to-scalar ratio in cosmic microwave background perturbations, as well as discussing the gravitino production following inflation.

Principles of the Unification of Our Agency

Science.gov (United States)

Roth, Klas

2011-01-01

Do we need principles of the unification of our agency, our mode of acting? Immanuel Kant and Christine Korsgaard argue that the reflective structure of our mind forces us to have some conception of ourselves, others and the world--including our agency--and that it is through will and reason, and in particular principles of our agency, that we…

Esclusas de peces en la represa de Salto Grande. Consideraciones acerca de su funcionamiento

OpenAIRE

Delfino, R.; Baigún, C.R.M.; Quirós, R.

1986-01-01

Fishlocks at Salto Grande Reservoir. Considerations about its functioning. The Salto Grande dam, has in its structure two Borland type fishlocks. The fish passage efficiency is low, and it is limited by the original system design, the management of the dam and the Uruguay river hidrology. Thus, in the 1984-1986 period, on annual average, the fishlocks were out of service 53 o/o of the time, while in the two periods when higher observed fish accumulation occur, march-april and september-octobe...

La herencia universitaria a 100 años de la reforma – debates y combates sobre su vigencia y perspectivas

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Pablo Imen

2018-04-01

Full Text Available El presente artículo se propone analizar, desde la perspectiva del siglo XXI, los acervos de la Reforma Universitaria de Córdoba, Argentina, el 15 de junio de 1918. En aquél entonces la reacción estudiantil contra una institución universitaria clerical, autoritaria y conservadora incluyó su crítica como una alternativa democratizadora que se expandió por América Latina. Durante el siglo XX hubo distintas experiencias que resultan aportes valiosos para pensar la Universidad del siglo XXI en el marco de la construcción de la Patria Grande a partir del reformismo y del nacionalismo popular revolucionario. La Declaración de Cartagena de Indias de 2008, por parte del Consejo Regional de Educación Superior (CRES de la UNESCO recupera estas herencias, proponiendo rescates de su espíritu democratizador en los planos del gobierno, su proyecto pedagógico y su proyección hacia los contextos nacionales y regionales

Deductive Synthesis of the Unification Algorithm,

Science.gov (United States)

1981-06-01

DEDUCTIVE SYNTHESIS OF THE I - UNIFICATION ALGORITHM Zohar Manna Richard Waldinger I F? Computer Science Department Artificial Intelligence Center...theorem proving," Artificial Intelligence Journal, Vol. 9, No. 1, pp. 1-35. Boyer, R. S. and J S. Moore [Jan. 19751, "Proving theorems about LISP...d’Intelligence Artificielle , U.E.R. de Luminy, Universit6 d’ Aix-Marseille II. Green, C. C. [May 1969], "Application of theorem proving to problem

The Tatar Tsarevitches in the Grand Duchy of Lithuania (15th–18th centuries »

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S.V. Dumin

2016-07-01

Full Text Available The article is devoted to the genealogy of the three families of the Tatar tsarevitches (Soltans, settled in the Grand Duchy of Lithuania in the 15th or early 16th century. The first of these (extinct until the mid 16th century descended from “tsarevitch Sihdohman from Perekop” (in all probability, from khan Sidi Ahmed. The second, tsarevitches Ostrynsky (extinct in the early 17th century, were descendants of the Crimean Giray dynasty. The third, ”tsarevitches Zavolzhsky”, called later “tsarevitches Punsky”, were the descendants of Halleck-Soltan, nephew of the last khan of the Great Horde Shah Ahmat (Sheikh Ahmed and they still existed in the first half of the 18th century. At the beginning of the 16th century these tsarevitches maintained their contacst with the Great Horde and Crimea and played some role in the diplomatic relations of the Grand Duchy and Tatar khanates. Later, they turned into ordinary military landowners, though they occupied the honored place in the Lithuanian Tatar aristocracy and retained their traditional title of tsarevitches (though often they also titled princes, like other noble Tatars.

Unification of Forces: The Road to Jointness?

Science.gov (United States)

1991-05-15

tend to resist large change--or innovation. Because organizations value "predictability, stability, and certainty," incremental change is the...preferred mode of behavior for organizations.29 Unification of the forces would be a large, rather than an incremental , change; thus, the services would...coordinating planning and bidgeting , providing unified direction, accounting and controlling weapons and equipment acquisition, eliminating duplication of

Quantum gravity unification via transfinite arithmetic and geometrical averaging

International Nuclear Information System (INIS)

El Naschie, M.S.

2008-01-01

In E-Infinity theory, we have not only infinitely many dimensions but also infinitely many fundamental forces. However, due to the hierarchical structure of ε (∞) spacetime we have a finite expectation number for its dimensionality and likewise a finite expectation number for the corresponding interactions. Starting from the preceding fundamental principles and using the experimental findings as well as the theoretical value of the coupling constants of the electroweak and the strong forces we present an extremely simple averaging procedure for determining the quantum gravity unification coupling constant with and without super symmetry. The work draws heavily on previous results, in particular a paper, by the Slovian Prof. Marek-Crnjac [Marek-Crnjac L. On the unification of all fundamental forces in a fundamentally fuzzy Cantorian ε (∞) manifold and high energy physics. Chaos, Solitons and Fractals 2004;4:657-68

Generalization of trinification to theories with 3N SU(3) gauge groups

International Nuclear Information System (INIS)

Carone, Christopher D.

2005-01-01

We consider a natural generalization of trinification to theories with 3N SU(3) gauge groups. These theories have a simple moose representation and a gauge boson spectrum that can be interpreted via the deconstruction of a 5D theory with unified symmetry broken on a boundary. Although the matter and Higgs sectors of the theory have no simple extra-dimensional analog, gauge unification retains features characteristic of the 5D theory. We determine possible assignments of the matter and Higgs fields to unified multiplets and present theories that are viable alternatives to minimal trinified GUTs

Reduced modular symmetries of threshold corrections and gauge coupling unification

Energy Technology Data Exchange (ETDEWEB)

Bailin, David; Love, Alex [Department of Physics & Astronomy, University of Sussex,Brighton, BN1 9QH (United Kingdom)

2015-04-01

We revisit the question of gauge coupling unification at the string scale in orbifold compactifications of the heterotic string for the supersymmetric Standard Model. In the presence of discrete Wilson lines threshold corrections with modular symmetry that is a subgroup of the full modular group arise. We find that reduced modular symmetries not previously reported are possible. We conjecture that the effects of such threshold corrections can be simulated using sums of terms built from Dedekind eta functions to obtain the appropriate modular symmetry. For the cases of the ℤ{sub 8}-I orbifold and the ℤ{sub 3}×ℤ{sub 6} orbifold it is easily possible to obtain gauge coupling unification at the “observed” scale with Kähler moduli T of approximately one.

Les représentations de la réunification allemande dans l’ex-Yougoslavie

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Laurent Hassid

2012-06-01

Full Text Available La réunification allemande a été perçue de manière différente dans les États de l’ex-Yougoslavie. En Serbie, république la plus peuplée de la Fédération et où se trouve le pouvoir central, elle est crainte comme le symbole d’une possible désintégration. En Croatie et en Slovénie s’est ainsi répandue l’idée que « si l’Allemagne peut se réunifier, la Yougoslavie peut bien se désintégrer » (Entretien avec Vladimir Radomirovic, ancien rédacteur en chef du quotidien serbe Politika et fondateur en 2009 de Pistaljka, site Internet qui dénonce la corruption dans les Balkans - www.pistaljka.rs. Au risque de provoquer une crise au sein de la CEE, l’Allemagne a poussé les autres grandes puissances du continent, dont la France, à reconnaître rapidement les indépendances des deux républiques. Pour comprendre les différentes représentations de la réunification allemande dans les Balkans, il est nécessaire d’étudier également les perceptions de la chute du Mur de Berlin, un an plus tôt. Symbole d’un communisme qui n’est pas tombé partout dans l’ex-Yougoslavie à partir de 1991, il a néanmoins grandement participé à la désintégration de la Fédération. Vingt ans après, l’Allemagne reste un acteur majeur dans la région, mais a abandonné une partie de son influence économique et politique au profit de l’Union européenne, notamment à partir de l’introduction de l’euro qui prend la place du mark, ancienne devise de référence.

Plan de actividades físico-recreativas para la ocupación del tiempo libre en los adolescentes de 15 a 18 años del Municipio Carirubana en el Consejo Comunal Sabana Grande

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Yamila Sánchez Bello

2011-12-01

Full Text Available El presente trabajo tiene como base el estudio acerca de la ocupación del tiempo libre, por su positiva influencia en la formación de la personalidad del hombre manifestada en su modo de vida al cambiar hábitos, ideología y cultura social de cómo ocuparlo. Consta de tres capítulos que van desde, las concepciones del tiempo libre y la recreación el primero sobre, la caracterización del grupo, la comunidad y resultados del diagnóstico inicial, donde se constata cuál es el tiempo libre que disponen los adolescentes y la poca sistematicidad en actividades, al aplicar de los métodos teóricos y empíricos en el segundo, y un tercer capítulo donde se realiza la fundamentación del plan de actividades físico-recreativa para ocupar el tiempo libre de los adolescentes y al final se analizan los resultados obtenido tras su puesta en marcha. Las actividades van acompañadas de acciones encaminadas a transformar conductas desacordes al buen desarrollo humano, para este propósito se escogieron un grupo de adolescentes en edades entre 15-18 años del municipio Carirubana en el Consejo Comunal Sabana Grande. El plan tuvo como base la aplicación de los conceptos: Tiempo libre, comunidad, adolescente.

José Nicolás de Azara : un icono del Grand Tour

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Jorge García Sánchez

2008-01-01

Full Text Available José Nicolás de Azara, bien conocido como Agente de Preces y ministro plenipotenciario ante la Santa Sede, fue tal vez la personalidad española de mayor influencia en los círculos intelectuales y artísticos de la Roma del siglo XVIII. Su asumida función de guía ilustrado y su vocación pedagógica para con los jóvenes viajeros lo convirtieron en un auténtico icono del Grand Tour.José Nicolás de Azara, well known as Agente de Preces (Agent of Supplications and ministro plenipotenciario (Plenipotentiary Minister in the Holy See, was perhaps the most influential Spanish personality in the intellectual and artistic circles of Eighteenth-Century Rome. His wilful function of enlightened guide and his pedagogic attitude towards the young travellers made of him an authentic icon of the Grand Tour.

Castro en su territorio

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Gonzalo Cerda Brintrup

1988-06-01

Full Text Available Su emplazamiento estaba dominado por sitios eriazos concentrándose las edificaciones más importantes en torno a la plaza (Iglesia, Convento, Edificios Públicos, Liceos y en calle Lillo, centro de la actividad comercial portuaria que, encaramadas sobre palafitos ponían un pie en el mar. Las grandes casonas de Lillo de dos y tres pisos con bodegas, locales comerciales, residenciales y hoteles serían reducidas a cenizas en el gran incendio de 1936.

Exploring the Use of Enterprise Content Management Systems in Unification Types of Organizations

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Arshad Noreen Izza

2014-03-01

Full Text Available The aim of this paper is to better understand how highly standardized and integrated businesses known as unification types of organizations use Enterprise Content Management Systems (ECMS to support their business processes. Multiple case study approach was used to study the ways two unification organizations use their ECMS in their daily work practices. Arising from these case studies are insights into the differing ways in which ECMS is used to support businesses. Based on the comparisons of the two cases, this study proposed that unification organizations may use ECMS in four ways, for: (1 collaboration, (2 information sharing that supports a standardized process structure, (3 building custom workflows that support integrated and standardized processes, and (4 providing links and access to information systems. These findings may guide organizations that are highly standardized and integrated in fashion, to achieve their intended ECMS-use, to understand reasons for ECMS failures and underutilization and to exploit technologies investments.

Aportes para la estimación de la huella de carbono en los grandes asentamientos urbanos de Argentina

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Rosana Ferraro

2013-07-01

Full Text Available El cambio climático y su efecto más inmediato, el calentamiento global, plantean desafíos para la gestión ambiental de las ciudades. Uno de ellos es estimar su huella de carbono con la finalidad de morigerar los potenciales impactos. El presente trabajo propone calcular las emisiones de CO2 producidas por las actividades antrópicas de los 15 asentamientos urbanos de Argentina de más de 300.000 habitantes. Para ello se analizaron por localidad los consumos de energía eléctrica y se calcularon las emisiones de CO2 por sector de demanda eléctrica. Los resultados muestran que Argentina, en general, y los grandes asentamientos, en particular, tienen una baja contribución de emisiones de CO2, que se asocian en orden decreciente con la actividad industrial, residencial y comercial.

Elementary particles and particle interactions

International Nuclear Information System (INIS)

Bethge, K.; Schroeder, U.E.

1986-01-01

This book is a textbook for an introductory course of elementary particle physics. After a general introduction the symmetry principles governing the interactions of elementary particles are discussed. Then the phenomenology of the electroweak and strong interactions are described together with a short introduction to the Weinberg-Salam theory respectively to quantum chromodynamics. Finally a short outlook is given to grand unification with special regards to SU(5) and cosmology in the framework of the current understanding of the fundamental principles of nature. In the appendix is a table of particle properties and physical constants. (HSI) [de

F-theory GUTs with U(1) symmetries: Generalities and survey

International Nuclear Information System (INIS)

Dolan, Matthew J.; Marsano, Joseph; Saulina, Natalia; Schaefer-Nameki, Sakura

2011-01-01

We study the structure of SU(5) F-theory grand unified theory (GUT) models that engineer additional U(1) symmetries. These are highly constrained by a set of relations observed by Dudas and Palti (DP) that originate from the physics of four-dimensional anomaly cancellation. Using the DP relations, we describe a general tension between unification and the suppression of dimension 5 proton decay when one or more U(1)'s are Peccei-Quinn (PQ) symmetries and hypercharge flux is used to break the SU(5) GUT group. We then specialize to spectral cover models, whose global completions in F theory we know how to construct. In that setting, we provide a technical derivation of the DP relations, construct spectral covers that yield all possible solutions to them, and provide a complete survey of spectral cover models for SU(5) GUTs that exhibit two U(1) symmetries.

Einstein's Last Dream: The Space–Time Unification of Fundamental ...

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 1. Einstein's Last Dream: The Space – Time Unification of Fundamental Forces. Abdus Salam. Reflections Volume 3 Issue 1 January 1998 pp 81-88. Fulltext. Click here to view fulltext PDF. Permanent link:

Educational Systems and Rising Inequality: Eastern Germany after Unification

Science.gov (United States)

von Below, Susanne; Powell, Justin J. W.; Roberts, Lance W.

2013-01-01

Educational systems considerably influence educational opportunities and the resulting social inequalities. Contrasting institutional regulations of both structures and contents, the authors present a typology of educational system types in Germany to analyze their effects on social inequality in eastern Germany after unification. After 1990, the…

Introduction to unification of electromagnetic and weak interactions

International Nuclear Information System (INIS)

Martin, F.

1980-01-01

After reviewing the present status of weak interaction phenomenology we discuss the basic principles of gauge theories. Then we show how Higgs mechanism can give massive quanta of interaction. The so-called 'Weinberg-Salam' model, which unifies electromagnetic and weak interactions, is described. We conclude with a few words on unification with strong interactions and gravity [fr

A4 family symmetry and quark-lepton unification

International Nuclear Information System (INIS)

King, Stephen F.; Malinsky, Michal

2007-01-01

We present a model of quark and lepton masses and mixings based on A 4 family symmetry, a discrete subgroup of an SO(3) flavour symmetry, together with Pati-Salam unification. It accommodates tri-bimaximal neutrino mixing via constrained sequential dominance with a particularly simple vacuum alignment mechanism emerging through the effective D-term contributions to the scalar potential

The string unification of gauge couplings and gauge kinetic mixings

International Nuclear Information System (INIS)

Hattori, Chuichiro; Matsuda, Masahisa; Matsuoka, Takeo; Mochinaga, Daizo.

1993-01-01

In the superstring models we have not only the complete 27 multiplets of E 6 but also extra incomplete (27+27-bar) chiral supermultiplets being alive at low energies. Associated with these additional multiplets, when the gauge symmetry contains more than one U(1) gauge group, there may exist gauge kinetic mixings among these U(1) gauge groups. In such cases the effect of gauge kinetic mixings should be incorporated into the study of unification of gauge couplings. We study these interesting effects systematically in these models. The string threshold effect is also taken into account. It is found that in the four-generation models we do not have an advisable solution of string unification of gauge couplings consistent with experimental values at the electroweak scale. We also discuss the possible scenarios to solve this problem. (author)

Phenomenology of the hierarchical lepton mass spectrum in the flipped SU(5)xU(1) string model

Energy Technology Data Exchange (ETDEWEB)

Leontaris, G.K.; Nanopoulos, D.V.

1988-09-29

A detailed phenomenological analysis of the lepton mass matrices and their implications in the low energy theory are discussed, within the recently proposed SU(5)xU(1) string model. The unification scale is highly constrained while the Yukawa couplings lie in a natural region. The flavour changing decays ..mu.. -> e..gamma.., ..mu.. -> 3e, ..mu.. -> e are highly suppressed while the depletion in the flux of muon neutrinos reported by the Kamiokande is explained through ..nu../sub ..mu../ reversible ..nu../sub tau/ oscillations.

Supersymmetric grand unified theories from quarks to strings via SUSY GUTs

CERN Document Server

Raby, Stuart

2017-01-01

These course-tested lectures provide a technical introduction to Supersymmetric Grand Unified Theories (SUSY GUTs), as well as a personal view on the topic by one of the pioneers in the field. While the Standard Model of Particle Physics is incredibly successful in describing the known universe it is, nevertheless, an incomplete theory with many free parameters and open issues. An elegant solution to all of these quandaries is the proposed theory of SUSY GUTs. In a GUT, quarks and leptons are related in a simple way by the unifying symmetry and their electric charges are quantized, further the relative strength of the strong, weak and electromagnetic forces are predicted. SUSY GUTs additionally provide a framework for understanding particle masses and offer candidates for dark matter. Finally, with the extension of SUSY GUTs to string theory, a quantum-mechanically consistent unification of the four known forces (including gravity) is obtained. The book is organized in three sections: the first section contai...

Unification of reactor elastomeric sealing based on material

International Nuclear Information System (INIS)

Sinha, N.K.; Raj, Baldev

2012-01-01

The unification of elastomeric sealing applications of Indian nuclear reactors based on a few qualified fluoroelastomer/perfluoroelastomer compounds and standardized approaches for finite element analysis (FEA) based design, manufacturing process and antifriction coatings is discussed. It is shown that the advance polymer architecture based Viton ® formulation developed for inflatable seals of 500 MWe Prototype Fast Breeder Reactor (PFBR) and its four basic variations can encompass other sealing applications of PFBR with minimum additional efforts on development and validation. Changing the blend ratio of Viton ® GBL 200S and 600S in inflatable seal formulation could extend its use to Pressurized Heavy Water Reactors (PHWRs). The higher operating temperature of Advanced Heavy Water Reactor (AHWR) seals expands the choice to perfluoroelastomers. FEA based on plane-strain/axisymmetric modeling (with Mooney–Rivlin as the basic constitutive model), seal manufacture by cold feed extrusion and injection molding as well as plasma Teflon-like coating belonging to two variations obtained from the development of inflatable seals provide the necessary standardization for unification. The gains in simplification of design, development and operation of seals along with the enhancements of safety and reliability are expected to be substantial.

Unification of three linear models for the transient visual system

NARCIS (Netherlands)

Brinker, den A.C.

1989-01-01

Three different linear filters are considered as a model describing the experimentally determined triphasic impulse responses of discs. These impulse responses arc associated with the transient visual system. Each model reveals a different feature of the system. Unification of the models is

Law behind second law of thermodynamics - unification with cosmology

International Nuclear Information System (INIS)

Nielsen, Holger B.; Ninomiya, Masao

2006-01-01

In an abstract setting of a general classical mechanical system as a model for the universe we set up a general formalism for a law behind the second law of thermodynamics, i.e. really for 'initial conditions'. We propose a unification with the other laws by requiring similar symmetry and locality properties

Radiative electroweak breaking with pseudo Goldstone Higgs doublets

International Nuclear Information System (INIS)

Ananthanarayan, B.; Shafi, Q.

1996-01-01

We consider a realistic example of supersymmetric grand unification based on SU(3) c xSU(3) L xSU(3) R in which the electroweak (EW) Higgs doublets are open-quote open-quote light close-quote close-quote as a consequence of the open-quote open-quote pseudo Goldstone close-quote close-quote mechanism. We discuss radiative EW breaking in this model, exploring in particular the open-quote open-quote small close-quote close-quote (order unity) and open-quote open-quote large close-quote close-quote (≅m t /m b ) tanβ regions by studying the variations of r 2 (≡μ 1,2 2 /μ 2 3 ), where μ 1,2,3 2 are the well-known MSSM parameters evaluated at the GUT scale. For |r| sufficiently close to unity the quantity tanβ can be of order unity, but the converse is not always true. copyright 1996 The American Physical Society

Profumo di SUSY: Suggestive Correlations in the ATLAS and CMS High Jet Multiplicity Data

CERN Document Server

Li, Tianjun; Nanopoulos, Dimitri V; Walker, Joel W

2011-01-01

We present persistently amassing evidence that the CMS and ATLAS Collaborations may indeed be already registering supersymmetry events at the Large Hadron Collider (LHC). Our analysis is performed in the context of a highly phenomenologically favorable model named No-Scale F-SU(5), which represents the unification of the F-lipped SU(5) Grand Unified Theory (GUT), two pairs of hypothetical TeV-scale vector-like supersymmetric multiplets derived out of F-Theory, and the dynamically established boundary conditions of No-Scale supergravity. We document highly suggestive correlations between the first inverse femtobarn of observations by CMS and ATLAS, where seductive excesses in multijet events, particularly those with nine or more jets, are unambiguously accounted for by a precision Monte-Carlo simulation of the F-SU(5) model space. This intimate correspondence is optimized by a unified gaugino mass in the neighborhood of M_{1/2}=518 GeV. We supplement this analysis by extrapolating for the expected data profile...

125 GeV Higgs boson mass from 5D gauge-Higgs unification

Science.gov (United States)

Carson, Jason; Okada, Nobuchika

2018-03-01

In the context of a simple gauge-Higgs unification (GHU) scenario based on the gauge group SU(3)×U(1)^' in a 5D flat space-time, we investigate the possibility of reproducing the observed Higgs boson mass of around 125 GeV. We introduce bulk fermion multiplets with a bulk mass and a (half-)periodic boundary condition. In our analysis, we adopt a low-energy effective theoretical approach of the GHU scenario, where the running Higgs quartic coupling is required to vanish at the compactification scale. Under this "gauge-Higgs condition," we investigate the renormalization group evolution of the Higgs quartic coupling and find a relation between the bulk mass and the compactification scale so as to reproduce the 125 GeV Higgs boson mass. Through quantum corrections at the one-loop level, the bulk fermions contribute to the Higgs boson production and decay processes and deviate the Higgs boson signal strengths at the Large Hadron Collider experiments from the Standard Model (SM) predictions. Employing the current experimental data that show that the Higgs boson signal strengths for a variety of Higgs decay modes are consistent with the SM predictions, we obtain lower mass bounds on the lightest mode of the bulk fermions to be around 1 TeV.

Problems of CP-violation in early unification theories

International Nuclear Information System (INIS)

Liparteliani, A.G.; Monich, V.A.; Volkov, G.G.

1985-01-01

The present work studies possible mechanisms of P and CP-violation in the frames of an approach based on early unification of fundamental local symmetries, i.e., Pati-Salam four-colour symmetry, extended weak isotopic symmetry and that of quark-lepton generations. The work also studies the influence of generations mixing on the rates of rare processes in each of 3 classes of interactions

Could a Weak Coupling Massless SU(5) Theory Underly the Standard Model S-Matrix

Science.gov (United States)

White, Alan R.

2011-04-01

The unitary Critical Pomeron connects to a unique massless left-handed SU(5) theory that, remarkably, might provide an unconventional underlying unification for the Standard Model. Multi-regge theory suggests the existence of a bound-state high-energy S-Matrix that replicates Standard Model states and interactions via massless fermion anomaly dynamics. Configurations of anomalous wee gauge boson reggeons play a vacuum-like role. All particles, including neutrinos, are bound-states with dynamical masses (there is no Higgs field) that are formed (in part) by anomaly poles. The contributing zero-momentum chirality transitions break the SU(5) symmetry to vector SU(3)⊗U(1) in the S-Matrix. The high-energy interactions are vector reggeon exchanges accompanied by wee boson sums (odd-signature for the strong interaction and even-signature for the electroweak interaction) that strongly enhance couplings. The very small SU(5) coupling, αQUD ≲ 1/120, should be reflected in small (Majorana) neutrino masses. A color sextet quark sector, still to be discovered, produces both Dark Matter and Electroweak Symmetry Breaking. Anomaly color factors imply this sector could be produced at the LHC with large cross-sections, and would be definitively identified in double pomeron processes.

THE COMPLETION OF THE CHURCH UNIFICATION FROM 1700-1701 UNDER THE BISHOP ATANASIE

Directory of Open Access Journals (Sweden)

Florin-Alin OROS

2013-11-01

Full Text Available The religious unification around year 1700, betweeen a part of the Orthodox believers from Transylvania and the Church of Rome, of Catholic religion, had represented an event that left a profound spiritual mark on the Romanian and Transylvanian population. The efforts for a Unification had started under the Orthodox bishop from Transylvania, Teofil (1692-1697, a part of the Orthodox priests being willing to accept it for a series of rights and benefits. These efforts could not be accomplished because of the sudden death of the bishop in 1697. As a result of the endeavours of the next bishop of the Romanians, Atanasie, a part of the Orthodox believers had joined the new Greek-Catholic communion around 1700-1701. There is no doubt that this historical and religious endeavour was not an easy one, Atanasie being compelled to „sail” in the muddy waters of the religious structure in Transylvania. This oscillation between the Orthodox and Catholic religions, under the strict supervision of the Imperial authorities from Wien, had triggered the completion of the religious Unification at the beginning of the 18th century and the development of the Greek-Catholic church in Transylvania.

Kink-induced symmetry breaking patterns in brane-world SU(3)^3 trinification models

OpenAIRE

Demaria, Alison; Volkas, Raymond R.

2005-01-01

The trinification grand unified theory (GUT) has gauge group SU(3)^3 and a discrete symmetry permuting the SU(3) factors. In common with other GUTs, the attractive nature of the fermionic multiplet assignments is obviated by the complicated multi-parameter Higgs potential apparently needed for phenomenological reasons, and also by vacuum expectation value (VEV) hierarchies within a given multiplet. This motivates the rigorous consideration of Higgs potentials, symmetry breaking patterns and a...

Astrophysical Probes of Varying Constants and Unification

International Nuclear Information System (INIS)

Martins, C J A P

2016-01-01

The observational evidence for the acceleration of the universe demonstrates that canonical theories of gravitation and particle physics are incomplete, if not incorrect. A new generation of astronomical facilities will soon carry out precision consistency tests of the standard cosmological model and search for evidence of new physics beyond it. I describe recent work of CAUP's Dark Side team on some of these tests, focusing on the stability of nature's fundamental couplings and tests of unification scenarios. (paper)

Proton decay in a nucleus: Nonrelativistic treatment of nuclear effects

International Nuclear Information System (INIS)

Fernandez, L.A.; Alvarez-Estrada, R.F.; Sanchez-Gomez, J.L.

1983-01-01

In this paper, proton decay in a large nucleus is studied in the framework of SU(5) grand unification theory (GUT). By using a method based upon the Green's-function technique of many-body physics, nuclear effects on spectator and pole terms are computed. The decay width in the nucleus is found to be practically the same as in free space. However, nuclear effects are of considerable importance concerning the positron spectrum. A density-correlation expansion is introduced which is useful for carrying out a systematic study of nuclear effects in proton decay in a large nucleus. The method presented here can be easily extended to other GUT's or supersymmetric GUT's

Supersymmetric family unification

International Nuclear Information System (INIS)

Frampton, P.H.; Kephart, T.W.

1983-01-01

The superheavy symmetry breaking of the gauge group in supersymmetrized unified theories is studied. The requirement that supersymmetry be unbroken strongly constrains the possible gauge group breaking, and we systematize such constraints group theoretically. In model building, one issue is whether to permit an adjoint matter superfield with concomitant color exotic fermions. A second issue is that of naturalness which is complicated by the well-known supersymmetry non-renormalization theorems. Both with and without an adjoint matter superfield, the most promising group appears to be SU(9) where three families can be naturally accommodated, at least for low-energy gauge group SU(3) x SU(2) x U(1). With an extra U(1) factor, as advocated by Fayet, the non-renormalization theorem must be exploited. (orig.)

Genesis of Electroweak Unification and the Higgs

CERN Multimedia

CERN. Geneva

2014-01-01

I will give a historical account of the developments leading up to the unification of weak and electromagnetic interactions, as I saw them from my standpoint in Imperial College London. I will describe the state of physics in the 1950s, the aim of finding a unified theory of various interactions, the obstacles encountered in trying to unify the weak and electromagnetic interactions, and their eventual resolution, with a brief discussion of the later history culminating in the discovery of the Higgs boson in 2012.

Supersymmetric SU(5) GUT with Stabilized Moduli

CERN Document Server

Antoniadis, Ignatios; Panda, Binata

2008-01-01

We construct a minimal example of a supersymmetric grand unified model in a toroidal compactification of type I string theory with magnetized D9-branes. All geometric moduli are stabilized in terms of the background internal magnetic fluxes which are of "oblique" type (mutually non-commuting). The gauge symmetry is just SU(5) and the gauge non-singlet chiral spectrum contains only three families of quarks and leptons transforming in the $10+{\\bar 5}$ representations.

LA GRANDE DESCENTE

CERN Multimedia

The first endcap disc of CMS being lowered slowly and carefully 100 m underground into the experimental cavern. The disc is one of 15 large pieces to make the grand descent.  The uniquely shaped slice, 16 m high, about 50 cm thick weighs 400 tonnes. The two HF that were lowered earlier in November can also be seen in the foreground and background.  

Standard(-like) Model from an SO(12) Grand Unified Theory in six-dimensions with S2 extra-space

International Nuclear Information System (INIS)

Nomura, Takaaki; Sato, Joe

2009-01-01

We analyze a gauge-Higgs unification model which is based on a gauge theory defined on a six-dimensional spacetime with an S 2 extra-space. We impose a symmetry condition for a gauge field and non-trivial boundary conditions of the S 2 . We provide the scheme for constructing a four-dimensional theory from the six-dimensional gauge theory under these conditions. We then construct a concrete model based on an SO(12) gauge theory with fermions which lie in a 32 representation of SO(12), under the scheme. This model leads to a Standard Model(-like) gauge theory which has gauge symmetry SU(3)xSU(2) L xU(1) Y (xU(1) 2 ) and one generation of SM fermions, in four-dimensions. The Higgs sector of the model is also analyzed, and it is shown that the electroweak symmetry breaking and the prediction of W-boson and Higgs-boson masses are obtained

Unification of Radio Galaxies and their Accretion Jet Properties

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... We investigate the relation between black hole mass, bh, and jet power, jet, for a sample of BL Lacs and radio quasars. We find that BL Lacs are separated from radio quasars by the FR I/II dividing line in bh-jet plane, which strongly supports the unification scheme of FR I/BL Lac and FR II/radio ...

Unification of Radio Galaxies and their Accretion Jet Properties ...

Indian Academy of Sciences (India)

Abstract. We investigate the relation between black hole mass, Mbh, and jet power, Qjet, for a sample of BL Lacs and radio quasars. We find that BL Lacs are separated from radio quasars by the FR I/II dividing line in Mbh–Qjet plane, which strongly supports the unification scheme of FR. I/BL Lac and FR II/radio quasar.

The unification of powerful radio-loud AGN: the multi-wavelength balance

NARCIS (Netherlands)

Podigachoski, Pece; Barthel, Peter; Haas, Martin; Leipski, Christian; Wilkes, Belinda; Rocca-Volmerange, Brigitte; Drouart, Guillaume

2016-01-01

Powerful radio-loud AGN, by virtue of their optically-thin low-frequency radio emission, represent unique targets in orientation-based unification studies, and in searches for orientation indicators and orientation invariants. Central in these efforts is the landmark Third Cambridge Catalog of Radio

MUC (Memory, Unification, Control and beyond

Directory of Open Access Journals (Sweden)

Peter eHagoort

2013-07-01

Full Text Available A neurobiological model of language is discussed that overcomes the shortcomings of the classical Wernicke-Lichtheim-Geschwind model. It is based on a subdivision of language processing into three components: Memory, Unification, and Control. The functional components as well as the neurobiological underpinnings of the model are discussed. In addition, the need for extension of the model beyond the classical core regions for language is shown. Attentional networks as well as networks for inferential processing are crucial to realize language comprehension beyond single word processing and beyond decoding propositional content. It is shown that this requires the dynamic interaction between multiple brain regions.

Quark-lepton unification and proton decay

International Nuclear Information System (INIS)

Pati, J.C.; Salam, A.

1980-05-01

Complexions for proton decay arising within a maximal symmetry for quark-lepton unification, which leads to spontaneous rather than intrinsic violations of B, L and F are considered. Four major modes satisfying δB=-1 and δF=0, -2, -4 and -6 are noted. It is stressed that some of these modes can coexist in accord with allowed solutions for renormalization group equations for coupling constants for a class of unifying symmetries. None of these remarks is dependent on the nature of quark charges. It is noted that if quarks and leptons are made of constituent preons, the preon binding is likely to be magnetic. (author)

Gravitational waves as cosmological probes for new physics between the electroweak and the grand-unification scale

International Nuclear Information System (INIS)

Sagunski, Laura

2013-04-01

Relic gravitational waves, generated by strongly first-order phase transitions in the early Universe, can serve as cosmological probes for new physics beyond the Standard Model. We investigate phase transitions at temperatures between the electroweak and the GUT scale in two extensions of the Standard Model for their possibility to provide detectable gravitational radiation. First, we study the Z 2 symmetry breaking phase transition in the Standard model extended by a real gauge singlet. The analysis yields that the gravitational wave amplitude of the first-order phase transition with a thermally induced barrier is several orders too small for being detectable. The second model we discuss is a left-right symmetric model based on the gauge group SU(2) L x SU(2) R x U(1) B-L generating a first-order phase transition already due to the emergence of a barrier in the tree-level potential. We derive an upper bound on the peak amplitude of the gravitational wave spectrum of the order h o 2 Ω GW ≅ 3 . 10 -11 . Hence, for very strong phase transitions a detection with the spaceborne interferometer LISA will be possible, whereas the sensitivity of the (cross-correlated) BBO detector will even allow to observe the gravitational wave spectrum within the whole parameter range of the model. By using the correlation between the characteristic parameters α and β of the gravitational wave spectrum, we finally compute the lower bounds on α(T * ) in dependence of the tunneling temperature T * which are necessary for a detection of the model spectrum by the specific detectors.

Unification of fuel elements for research reactors

International Nuclear Information System (INIS)

Vatulyn, A.V.; Stetskyi, Y.A.; Dobrikova, I.V.

1997-01-01

To the purpose of fuel elements unification the possibility of rod fuel assembly (FA) using in the cores of research reactors have been considered in this paper. The calculation results of geometric, hydraulic and thermotechnical parameters of rod assembly are submitted. Several designs of finned square fuel element and fuel assembly are proposed on base of analysis of rod FA characteristics in compare of tube ones. The fuel elements specimens and the model assembly are manufactured. The developed designs are the basis for further optimization after neutron-physical calculations of cores. (author)

Entering tennis men’s Grand Slams within the top-10 and its relationship with the fact of winning the tournament. [Acceder a los Grand Slams de tenis masculino desde el top-10 y su relación con el hecho de ganar el torneo].

Directory of Open Access Journals (Sweden)

Jaime Prieto-Bermejo

2016-10-01

Full Text Available The purpose of this study was to analyse the relationship between entering tennis men’s singles Grand Slams within the top-10 ranking (i.e. title favourites and the fact of winning the tournament. In order to differentiate between these players in a more powerful way than just considering the ranking number, a cluster algorithm was used to classify the players into two groups depending on their number of ranking points (i.e. higher level top-10 players vs. lower level top-10 players. The possible winners entering the tournament outside the top-10 (if any were also considered. The sample comprised all the 92 men’s singles Grand Slams played between 1990 and 2012. As was expected, the majority of Grand Slams were won by players entering the tournament ranked in the top-10. However, the main result is contrary to the hypothesis that there would be significant differences in the number of titles won in favour of the players entering the tournament from the higher positions of the top-10 when comparing to those won by the players entering from the lower positions of the top-10. Several factors that may influence whether and to what extent a player is more or less favourite to win a Grand Slam title are presented in the discussion. Resumen El propósito del estudio fue analizar la relación entre acceder a los Grand Slam de tenis masculino desde el top-10 del ranking (favoritos al título y el hecho de ganar el torneo. Con el objeto de diferenciar a estos jugadores de una forma más potente que simplemente considerando su número de ranking, se empleó un algoritmo cluster que clasificó a los jugadores en dos grupos en función del número de puntos de ranking (jugadores de mayor nivel dentro del top-10 v. jugadores de menor nivel del top-10. Los posibles ganadores del torneo accediendo al mismo desde posiciones fuera del top-10 (si los hubiera fueron también considerados. La muestra comprendió los 92 torneos de Grand Slam masculinos jugados

Cosmological grand unification monopoles: astrophysical constraints

International Nuclear Information System (INIS)

Fry, J.N.

1982-01-01

I review the general arguments which suggest that relic GU magnetic monopoles should emerge from the early universe, and I discuss several astrophysical settings in which their effects could be, but are not, observed. This places limits on their possible flux, and their abundance bound to more ordinary material

Introduction to quantum field theory

International Nuclear Information System (INIS)

Kazakov, D.I.

1988-01-01

The lectures appear to be a continuation to the introduction to elementary principles of the quantum field theory. The work is aimed at constructing the formalism of standard particle interaction model. Efforts are made to exceed the limits of the standard model in the quantum field theory context. Grand unification models including strong and electrical weak interactions, supersymmetric generalizations of the standard model and grand unification theories and, finally, supergravitation theories including gravitation interaction to the universal scheme, are considered. 3 refs.; 19 figs.; 2 tabs

Do Unification Models Explain the X-ray Properties of Radio Sources?

NARCIS (Netherlands)

Wilkes, Belinda J.; Kuraszkiewicz, J.; Haas, M.; Barthel, P.; Willner, S. P.; Leipski, C.; Worrall, D.; Birkinshaw, M.; Antonucci, R. R.; Ashby, M.; Chini, R.; Fazio, G. G.; Lawrence, C. R.; Ogle, P. M.; Schulz, B.

Chandra observations of a complete, flux-limited sample of 38 high-redshift (1 Unification models and lead to estimates of the covering

[Laboratory unification: advantages and disadvantages for clinical microbiology].

Science.gov (United States)

Andreu, Antonia; Matas, Lurdes

2010-10-01

This article aims to reflect on which areas or tasks of microbiology laboratories could be unified with those of clinical biochemistry, hematology, immunology or pathology laboratories to benefit patients and the health system, as well as the areas that should remain independent since their amalgamation would not only fail to provide a benefit but could even jeopardize the quality of microbiological diagnosis, and consequently patient care. To do this, the distinct analytic phases of diagnosis are analyzed, and the advantages and disadvantages of amalgamation are evaluated in each phase. The pros and cons of the unification of certain areas such as the computer system, occupational risk units, customer service, purchasing logistics, and materials storage, etc, are also discussed. Lastly, the effect of unification on urgent microbiology diagnosis is analyzed. Microbiological diagnosis should be unique. The microbiologist should perform an overall evaluation of the distinct techniques used for a particular patient, both those that involve direct diagnosis (staining, culture, antigen detection techniques or molecular techniques) and indirect diagnosis (antibody detection). Moreover, the microbiology laboratory should be independent, with highly trained technicians and specialists in microbiology that provide added value as experts in infection and as key figures in the process of establishing a correct etiological diagnosis. Copyright © 2010 Elsevier España S.L. All rights reserved.

Gravitational waves as cosmological probes for new physics between the electroweak and the grand-unification scale

Energy Technology Data Exchange (ETDEWEB)

Sagunski, Laura

2013-04-15

Relic gravitational waves, generated by strongly first-order phase transitions in the early Universe, can serve as cosmological probes for new physics beyond the Standard Model. We investigate phase transitions at temperatures between the electroweak and the GUT scale in two extensions of the Standard Model for their possibility to provide detectable gravitational radiation. First, we study the Z{sub 2} symmetry breaking phase transition in the Standard model extended by a real gauge singlet. The analysis yields that the gravitational wave amplitude of the first-order phase transition with a thermally induced barrier is several orders too small for being detectable. The second model we discuss is a left-right symmetric model based on the gauge group SU(2){sub L} x SU(2){sub R} x U(1){sub B-L} generating a first-order phase transition already due to the emergence of a barrier in the tree-level potential. We derive an upper bound on the peak amplitude of the gravitational wave spectrum of the order h{sub o}{sup 2}{Omega}{sub GW} {approx_equal} 3 . 10{sup -11}. Hence, for very strong phase transitions a detection with the spaceborne interferometer LISA will be possible, whereas the sensitivity of the (cross-correlated) BBO detector will even allow to observe the gravitational wave spectrum within the whole parameter range of the model. By using the correlation between the characteristic parameters {alpha} and {beta} of the gravitational wave spectrum, we finally compute the lower bounds on {alpha}(T{sub *}) in dependence of the tunneling temperature T{sub *} which are necessary for a detection of the model spectrum by the specific detectors.

NÃveis de isoleucina digestÃvel sobre o desempenho de fÃmeas suÃnas dos 15 aos 30 kg

OpenAIRE

Leandro Dalcin Castilha

2011-01-01

Com o objetivo de determinar a exigÃncia de isoleucina digestÃvel para fÃmeas suÃnas dos 15 aos 30 kg, foram realizados dois experimentos, um ensaio de desempenho e um balanÃo do nitrogÃnio. No primeiro experimento, foram utilizadas 40 fÃmeas suÃnas, mestiÃas, de alto potencial genÃtico e desempenho mÃdio, com peso vivo inicial de 15,00 Â 0,52kg, distribuÃdas em um delineamento experimental de blocos ao acaso, constituÃdo de cinco tratamentos (0,45; 0,52; 0,59; 0,66; 0,73% de isoleucina diges...

Signatures of lower-scale gauge coupling unification in the standard model due to extended Higgs sector

International Nuclear Information System (INIS)

Chizhov, M. V.; Bednyakov, V. A.

2016-01-01

The gauge coupling unification can be achieved at a unification scale around 5×10"1"3 GeV if the Standard Model scalar sector is extended with extra Higgs-like doublets. The relevant new scalar degrees of freedom in the form of chiral Z* and W* vector bosons might “be visible” already at about 700 GeV. Their eventual preferred coupling to the heavy quarks explains the non observation of these bosons in the first LHC run and provides promising expectation for the second LHC run.

Flocculent and grand design spiral galaxies in groups: time scales for the persistence of grand design spiral structures

International Nuclear Information System (INIS)

Elmegreen, B.G.; Elmegreen, D.M.

1983-01-01

Spiral arm classifications were made for 261 low-inclination galaxies in groups listed by Huchra and Geller. The fractional occurrence of grand design spiral structure in nonbarred galaxies was found to increase from approx.0.1 to approx.0.6 and then level off as the group crossing rate or galaxy collision rate in a group increases. A simple model is discussed where the random encounters between galaxies of any type and flocculent galaxies induce transient grand design spirals in the flocculent galaxies. If this grand-design stimulation occurs for binary collisions with impact parameters less than αR 25 , were R 25 is the galactic radius at 25 mag arcsec - 2 , and if the induced grand design spirals persist for an average time equal to #betta# galactic rotations, then the quantity α 2 #betta# equals approximately 3 x 10 4 . If binary collisions are responsible for grand design spirals, then this result implies either that the induced spirals last for many galactic rotations (#betta#>15), or that they can be stimulated by very remote encounters (α>45.) Alternatively, grand design spirals may be stimulated by multiple galaxy encounters, which would be the case for such large α, or by interactions with the potential well of the associated group, rather than by simple binary encounters. Weak correlations between the grand design fraction and the galaxy size, or between this fraction and the total number of galaxies in a group, were also found. Spiral structures of barred galaxies show no correlations with group environment

Neutrino masses and the unification of the SO(10) families

International Nuclear Information System (INIS)

Maalampi, J.; Enqvist, K.

1980-01-01

We show that the unification of the SO(10) families in SO(10+m) group can offer a solution to the neutrino mass problem. For simplicity we have restricted our analysis to SO(11), which contains - aside from generation mixing -the main novel feature of the theories of this kind: fermions that couple by V+A charged weak currents. (author)

Tratamento de dejetos suínos com biorreator UASB

Directory of Open Access Journals (Sweden)

Pablo Costa da Silva

2014-05-01

Full Text Available Esse trabalho tem por objetivo analisar a importância do biodigestor UASB no tratamento de dejetos suínos. A suinocultura possui papel importante quanto ao desenvolvimento econômico do Brasil. No entanto, o aumento de produção vem causando problemas ambientais graves, por conta do grande volume de resíduos sólidos gerados pela atividade. O desenvolvimento de métodos de tratamento de dejetos que agreguem valor à produção e respeitem as leis ambientais é um dos grandes desafios do setor. A biodigestão anaeróbia é um dos métodos mais eficazes para o tratamento de dejetos de suinoculturas. Este método de digestão, denominado UASB, tem como característica principal a produção de biogás e de biofertilizante, produto rico em nutrientes, e livre de patógenos. O método oferece vantagens como a promoção do bem estar animal, o aumento da fertilidade do solo, a diminuição da poluição e da emissão de gases geradores do efeito estufa e a melhoria da qualidade de vida, nos centros produtores de suínos, além de minimizar problemas relacionados ao déficit de energia elétrica. Portanto, a utilização de biodigestores UASB para o tratamento de dejetos de suínos é uma opção interessante, que deve ser avaliada com seriedade.

Grand Canyon Monitoring and Research Center

Science.gov (United States)

Hamill, John F.

2009-01-01

The Grand Canyon of the Colorado River, one of the world's most spectacular gorges, is a premier U.S. National Park and a World Heritage Site. The canyon supports a diverse array of distinctive plants and animals and contains cultural resources significant to the region's Native Americans. About 15 miles upstream of Grand Canyon National Park sits Glen Canyon Dam, completed in 1963, which created Lake Powell. The dam provides hydroelectric power for 200 wholesale customers in six western States, but it has also altered the Colorado River's flow, temperature, and sediment-carrying capacity. Over time this has resulted in beach erosion, invasion and expansion of nonnative species, and losses of native fish. Public concern about the effects of Glen Canyon Dam operations prompted the passage of the Grand Canyon Protection Act of 1992, which directs the Secretary of the Interior to operate the dam 'to protect, mitigate adverse impacts to, and improve values for which Grand Canyon National Park and Glen Canyon National Recreation Area were established...' This legislation also required the creation of a long-term monitoring and research program to provide information that could inform decisions related to dam operations and protection of downstream resources.

The origin of baryon number and related problems

International Nuclear Information System (INIS)

Schramm, D.N.; Turner, M.S.

1980-01-01

The possibility of cosmological baryon production, as motivated by grand unification, is discussed. It is postulated that the application of grand unified theories of particle interactions may explain the origin of baryons in the universe. (C.F.)

Why unify

International Nuclear Information System (INIS)

Georgi, H.

1980-01-01

Unified gauge theories such as SU(5) of particle interactions are built on the colour SU(3) and SU(2) x U(1) gauge theories which apparently describe strong and weak and electromagnetic interactions at distances as small as 10 -16 cm. In this article the classical reasons for going beyond SU(3)xSU(2)xU(1) to a fully unified theory such as SU(5) are reviewed, and a new reason formulated. A class of imaginary worlds similar to our own is considered and it is shown that unification is possible only in ours. This suggests that the low-energy interactions are unique in that they are constructed to make unification possible. (author)

Posicionamiento de la comunicación estratégica como gestión gerencial en las empresas más grandes de Colombia

Directory of Open Access Journals (Sweden)

Claudia Patricia Salas Forero

2013-01-01

Full Text Available Para Martín-Barbero y Rey (1999, el estudio de la comunicación se enfoca, a comienzos de la actual década, en la comunicación organizacional, marcado por un enfoque estratégico para alcanzar su estatus de gestión gerencial y su poder. El objetivo de este estudio es determinar si se está ejerciendo la función gerencial de la comunicación en las compañías más grandes y de mayores ventas en Colombia. Por medio de encuestas personales y por teléfono se realizaron preguntas semiestructuradas a los directores de comunicación de las 21 empresas de mayores ventas en Colombia, de acuerdo con la lista de la revista Dinero (2010. Se encontró que aunque hay un posicionamiento en general positivo de los directivos encargados de la comunicación estratégica en las empresas más grandes de Colombia, su influencia es limitada en ciertas áreas, responsabilidades o stakeholders, con lo cual no cumplen a cabalidad su gestión estratégica.

Integrable multi parametric SU(N) chain

International Nuclear Information System (INIS)

Foerster, Angela; Roditi, Itzhak; Rodrigues, Ligia M.C.S.

1996-03-01

We analyse integrable models associated to a multi parametric SU(N) R-matrix. We show that the Hamiltonians describe SU(N) chains with twisted boundary conditions and that the underlying algebraic structure is the multi parametric deformation of SU(N) enlarged by the introduction of a central element. (author). 15 refs

The phase transition in the SU(5) model at high temperatures

International Nuclear Information System (INIS)

Daniel, M.; Vayonakis, C.E.

1981-01-01

Within the minimum GUT model we have studied the nature of the fluctuation-induced transition between the SU(5) and the SU(3)sub(c) x SU(2) x U(1) phase which occurs at high temperatures. Our analysis is limited to the case when the phase transition occurs outside the critical (fluctuation-dominated) region. For this to happen the SU(5) model has to be in a mode analogous to the type I superconductor. This corresponds to having the scalar quartic couplings in the Higgs sector less than the squared gauge coupling. For generic values of the coupling constants the phase transition is found to be weakly first order. As we approach the boundaries for the region of the SU(3)sub(c) x SU(2) x U(1) phase, however, a strong first-order transition occurs. The SU(5) mode (analogous to the type II superconductor) when the phase transition occurs inside the fluctuation-dominated region has been recently studied by Ginsparg. His results together with ours show that there is a continuous merging of the type I mode into the type II mode. Finally our analysis elucidates some aspects of the monopole problem in grand unified theories. (orig.)

Light higgsino for gauge coupling unification

Directory of Open Access Journals (Sweden)

Kwang Sik Jeong

2017-06-01

Full Text Available We explore gauge coupling unification and dark matter in high scale supersymmetry where the scale of supersymmetry breaking is much above the weak scale. The gauge couplings unify as precisely as in low energy supersymmetry if the higgsinos, whose mass does not break supersymmetry, are much lighter than those obtaining masses from supersymmetry breaking. The dark matter of the universe can then be explained by the neutral higgsino or the gravitino. High scale supersymmetry with light higgsinos requires a large Higgs mixing parameter for electroweak symmetry breaking to take place. It is thus naturally realized in models where superparticle masses are generated at loop level while the Higgs mixing parameter is induced at tree level, like in anomaly and gauge mediation of supersymmetry breaking.

Light higgsino for gauge coupling unification

Energy Technology Data Exchange (ETDEWEB)

Jeong, Kwang Sik, E-mail: ksjeong@pusan.ac.kr

2017-06-10

We explore gauge coupling unification and dark matter in high scale supersymmetry where the scale of supersymmetry breaking is much above the weak scale. The gauge couplings unify as precisely as in low energy supersymmetry if the higgsinos, whose mass does not break supersymmetry, are much lighter than those obtaining masses from supersymmetry breaking. The dark matter of the universe can then be explained by the neutral higgsino or the gravitino. High scale supersymmetry with light higgsinos requires a large Higgs mixing parameter for electroweak symmetry breaking to take place. It is thus naturally realized in models where superparticle masses are generated at loop level while the Higgs mixing parameter is induced at tree level, like in anomaly and gauge mediation of supersymmetry breaking.

Low-luminosity Blazars in Wise: A Mid-infrared View of Unification

Science.gov (United States)

Plotkin, Richard M.; Anderson, S. F.; Brandt, W. N.; Markoff, S.; Shemmer, O.; Wu, J.

2012-01-01

We use the preliminary data release from the Wide-Field Infrared Survey Explorer (WISE) to perform the first statistical study on the mid-infrared (IR) properties of a large number ( 102) of BL Lac objects -- low-luminosity Active Galactic Nuclei (AGN) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions (SEDs), and the shape of their SEDs in the IR correlates well with SED peak frequency. In other BL Lac objects, the jet is not strong enough to completely dilute the rest of the AGN, and we do not see observational signatures of the dusty torus from these weakly beamed BL Lac objects. While at odds with simple unification, the missing torus is consistent with recent suggestions that BL Lac objects are fed by radiatively inefficient accretion flows. We discuss implications on the ``nature vs. nurture" debate for FR I and FR II galaxies, and also on the standard orientation-based AGN unification model.

Exchange-Rate Unification with Black Market Leakages; Russia 1992

OpenAIRE

Linda S. Goldberg

1993-01-01

In 1992 Russia unified the multiple exchange rates that had applied to international transactions. This paper describes the multiple exchange rate system that existed in Russia prior to mid-1992 and undertakes a theoretical exploration of the effects of the exchange rate unification that took place in July 1992. The model developed here allows for leakages between official and black markets and permits flexibility of the exchange rates in both official and parallel currency markets. Within th...

Yukawa unification in moduli-dominant SUSY breaking

International Nuclear Information System (INIS)

Khalil, S.; Tatsuo Kobayashi

1997-07-01

We study Yukawa in string models with moduli-dominant SUSY breaking. This type of SUSY breaking in general leads to non-universal soft masses, i.e. soft scalar masses and gaugino masses. Such non-universality is important for phenomenological aspects of Yukawa unification, i.e., successful electroweak breaking, SUSY corrections to the bottom mass and the branching ratio of b → sγ. We show three regions in the whole parameter space which lead to successful electroweak breaking and allow small SUSY corrections to the bottom mass. For these three regions we investigated the b → sγ decay and mass spectra. (author). 26 refs, 6 figs

Geometrical theory of ghost and Higgs fields and SU(2/1)

International Nuclear Information System (INIS)

Ne'eman, Y.; Thierry-Mieg, J.

1979-10-01

That a Principal Fiber Bundle provides a precise geometrical representation of Yang-Mills gauge theories has been known since 1963 and used since 1975. This work presents an entirely new domain of applications. The Feynman-DeWitt-Fadeev-Popov ghost-fields required in the renormalization procedure are identified with geometrical objects in the Principal Bundle. This procedure directly yields the BRS equations guaranteeing unitarity and Slavnov-Taylor invariance of the quantum effective Lagrangian. Except for one ghost field and its variation, this entire symmetry thus corresponds to classical notions, in that it is geometrical, and completely independent of the gauge-fixing procedure, which determines the quantized Lagrangian. These results may be used to fix the signs associated with the various ghost loops of quantum supergravity. The result is based upon the identification of a geometrical Z(2) x Z(2) double-gradation of the generalized fields in supergravity: [physical/ghost] fields and [integer/half integer] spins. Then the case of a supergroup as an internal symmetry gauge is considered. Ghosts geometrically associated to odd generators may be identified with the Goldstone-Nambu Higgs-Kibble scalar fields of conventional models with spontaneous symmetry breakdown. As an example, the chiral SU(3)/sub L/ x SU(3)/sub R/ flavor symmetry is realized by gauging the supergroup Q(3).Lastly, the main results concerning asthenodynamics (Weak-EM Unification) as given by the ghost-gauge SU(2/1) supergroup are recalled. 1 table

Beyond the CMSSM without an accelerator: proton decay and direct dark matter detection

International Nuclear Information System (INIS)

Ellis, John; Evans, Jason L.; Olive, Keith A.; Luo, Feng; Nagata, Natsumi; Sandick, Pearl

2016-01-01

We consider two potential non-accelerator signatures of generalizations of the well-studied constrained minimal supersymmetric standard model (CMSSM). In one generalization, the universality constraints on soft supersymmetry-breaking parameters are applied at some input scale M in below the grand unification (GUT) scale M GUT , a scenario referred to as 'sub-GUT'. The other generalization we consider is to retain GUT-scale universality for the squark and slepton masses, but to relax universality for the soft supersymmetry-breaking contributions to the masses of the Higgs doublets. As with other CMSSM-like models, the measured Higgs mass requires supersymmetric particle masses near or beyond the TeV scale. Because of these rather heavy sparticle masses, the embedding of these CMSSM-like models in a minimal SU(5) model of grand unification can yield a proton lifetime consistent with current experimental limits, and may be accessible in existing and future proton decay experiments. Another possible signature of these CMSSM-like models is direct detection of supersymmetric dark matter. The direct dark matter scattering rate is typically below the reach of the LUX-ZEPLIN (LZ) experiment if M in is close to M GUT , but it may lie within its reach if M in

Estrés entre rejas: Los grandes felinos en cautividad

OpenAIRE

Lobo Sánchez, Emilio; Outomuro López, Carolina; Pereira Regueira, María

2017-01-01

Los objetivos de este trabajo son los siguientes: - Conocer los factores desencadenantes de estrés en grandes felinos en cautividad. - Diferenciar los comportamientos anómalos derivados del diestrés. - Comprender los métodos para cuantificar el nivel de estrés. - Formas de disminuir el estrés mediante enriquecimiento ambiental. El estrés es un mecanismo de los seres vivos para responder ante una situación de amenaza y mantener su homeostasis, adaptándose así al estímulo estreso...

Luis Felipe Fajardo (1927-2013. Su vida y su obra

Directory of Open Access Journals (Sweden)

Hernando Sarasti Obregón

2017-09-01

Full Text Available FragmentoTeniendo en cuenta los grandes logros de este médico colombiano, en la Academia Nacional de Medicina se le rindió un homenaje a su memoria. Los ponentes de la sesión fueron los académicos Sarasti y Patiño. Por lo importante del tema, hemos querido incluir sus presentaciones en este artículo de la revista MEDICINA. El tema tocado por el doctor Sarasti fue el siguiente:El 5 de julio de 2013 falleció en los Estados Unidos en la ciudad de Palo Alto, California, el patólogo colombiano Dr. Luis Felipe Fajardo Lobo- Guerrero. Había nacido en Bogotá el 23 de enero de 1927 en el hogar de Don Luís Antonio Fajardo Suárez y Doña María Teresa Lobo-Guerrero.Se graduó como Bachiller en el Colegio de La Salle en 1944, hizo su medicatura rural en Restrepo (Meta y recibió el título de Médico en la Facultad de Medicina de la Universidad Nacional de Colombia en 1952. Inició su entrenamiento en Patología en el Hospital San Juan de Dios de Bogotá y lo continuó en los Estados Unidos en la Universidad de Yale entre 1954 y 1958. Ese mismo año fue certificado por el American Board of Pathology, contrajo matrimonio con Lorela Enterline y regresó a Colombia a ejercer su especialidad en el Hospital de la Samaritana.En noviembre de 1959 volvió a los Estados Unidos para ocupar un “locum tenens” en Connecticut en el New Britain General Hospital y regresó nuevamente a Colombia en octubre de 1960 como Profesor Asistente de Patología de la Universidad Nacional al mismo tiempo que fue Jefe del Laboratorio Clínico del Hospital San Juan de Dios.El Dr. Fajardo y el suscrito formábamos parte de la generación de médicos colombianos que hacia mediados del siglo XX viajamos a los Estados Unidos para especializarnos en diversas ramas de la Medicina.

Intoxicação em suínos pela ingestão de sementes de Aeschynomene indica (Leg.Papilionoideae)

OpenAIRE

Oliveira,Fabiano N.; Rech,Raquel R.; Rissi,Daniel R.; Barros,Ricardo R.; Barros,Claudio S.L.

2005-01-01

Relata-se um surto espontâneo de intoxicação em suínos pela ingestão de sementes de Aeschynomene indica e a reprodução da doença nessa espécie animal. O surto espontâneo ocorreu numa propriedade de criação de suínos localizada na região central do Rio Grande do Sul. Nessa propriedade havia 100 suínos (20 matrizes e 80 suínos jovens de várias categorias). Os suínos eram alimentados com uma ração feita na propriedade pela mistura de 50% farelo de milho, 25% de farelo de soja, 5% de um suplement...

Unification of Frequency direction Pilot-symbol Aided Channel Estimation (PACE) for OFDM

DEFF Research Database (Denmark)

Rom, Christian; Manchón, Carles Navarro; Deneire, Luc

2007-01-01

their specificities, namely the presence of virtual subcarriers and non-sample-spaced channels. To ease this choice, we propose a unified presentation of estimators encompassing most of the algorithms that can be found in literature, which only differ by the assumptions made on the channel. This unification leads...

El fiscal Roa Bastos: escenas del “Cristo paraguayo” y su guerra grande

OpenAIRE

Paco Tovar

2015-01-01

In 1993, Augusto RoaBastos published El fiscal, a novel in which he revisits a moment in Paraguay’s contemporary history, offering, from a contemporary perspective opposed to Alfredo Stroessner’s dictatorship, a view to la Guerra Grande, marshall SolanoLópez and Doña Elisa Lynch. History and caracters shaped to some Félix Moral taste, get their final shape in an unfinished script, faithfull to the deeds, as describing another version of the reality for a failed film production about the same ...

The grand unified link between the Peccei-Quinn mechanism and the generation puzzle

International Nuclear Information System (INIS)

Davidson, A.; Wali, K.C.

1982-03-01

The essential ingredients of the Peccei-Quinn mechanism are shown to be dictated by a proper choice of a grand unification scheme. The presence of U(1)sub(PQ) gives rise to the possibility that the same physics which resolves the strong CP-violation problem may decode the generation puzzle with no extra cost. Multigenerational signatures of the invisible axion scenario, such as the canonical fermion mass matrix, are discussed. The uniqueness and the special values of the quantized PQ-assignments, namely 1,-3,5-7,... for successive generations, acquire an automatic explanation once the idea of ''horizontal compositeness'' is invoked. A characteristic feature then is that the muon appears to have a less complicated structure than the electron. Furthermore, U(1)sub(PQ) chooses SO(10) to be its only tenable gauge symmetry partner, and at the same time crucially restricts the associated Higgs system. All this finally results in a consistent fermion mass hierarchy with log m, to the crudest estimation, varying linearly with respect to the generation index. (author)

Sfermion mass degeneracy, superconformal dynamics, and supersymmetric grand unified theories

International Nuclear Information System (INIS)

Kobayashi, Tatsuo; Noguchi, Tatsuya; Nakano, Hiroaki; Terao, Haruhiko

2002-01-01

We discuss issues in a scenario where hierarchical Yukawa couplings are generated through the strong dynamics of superconformal field theories (SCFTs). Independently of the mediation mechanism of supersymmetry breaking, the infrared convergence property of SCFTs can provide an interesting solution to the supersymmetric flavor problem; sfermion masses are suppressed around the decoupling scale of SCFTs and eventually become degenerate to some degree, thanks to family-independent radiative corrections governed by the gaugino masses of the minimal supersymmetric standard model (MSSM). We discuss under what conditions the degeneracy of the sfermion mass can be estimated in a simple manner. We also discuss the constraints from lepton flavor violations. We then explicitly study sfermion mass degeneracy within the framework of grand unified theories coupled to SCFTs. It is found that the degeneracy for right-handed sleptons becomes worse in the conventional SU(5) model than in the MSSM. On the other hand, in the flipped SU(5)xU(1) model, each right-handed lepton is still an SU(5) singlet, whereas the B-ino mass M 1 is determined by two independent gaugino masses of SU(5)xU(1). These two properties enable us to have an improved degeneracy for the right-handed sleptons. We also speculate on how further improvement can be obtained in the SCFT approach

Diagnóstico das lavouras de arroz do Rio Grande do Sul: Safras 2004/2005 x 2014/2015 = Diagnosis of rice field in Rio Grande do Sul: 2004/05 x 2014/15 crops

Directory of Open Access Journals (Sweden)

Mário Sérgio de Lima Azeredo

2017-04-01

Full Text Available Este trabalho avaliou os resultados financeiros e respectivas capacidades de investimentos de 1.217 lavouras de arroz irrigado, no sistema de cultivo mínimo, com participação simultânea nas safras 2004/05 e 2014/15 no estado do Rio Grande do Sul. Aplicou-seanálise de sensibilidade, considerando diferentes cenários para os componentes dos custos variáveis, custos fixos desembolsáveis e comportamento da produtividade. Na análise de investimento, a safra 2004/05 apresentou resultado negativo no Valor Presente Líquido [VPL], em todas as simulações. A safra 2014/15, com custo variável e despesas de custeio inferiores a 10%, sem redução da produtividade em 5% ou mais, apresentou VPL positivo. Por conseguinte, a Taxa Interna de Retorno [TIR] e o payback descontado [PDB] foram favoráveis à aquisição de uma colhedora, objeto da análise para o Fluxo de Caixa Líquido [FCL] do investimento proposto. = This work evaluated the financial results and respective investment capacities of 1,217 irrigated rice crops in the system of the minumum-tillage with simultaneous participation in the 2004/05 and 2014/15 harvests in the state of Rio Grande do Sul. A sensitivity analysis was applied considering different scenarios for the components of variable costs, disbursable fixed costs and productivity behavior. In the investment analysis, the 2004/05 harvest presented a negative result in the Net Present Value [NPV] in all simulations. The 2014/15 harvest, with variable costs and costs of less than 10%, without reduction of productivity 5% or more presented a positive NPV. The Internal Rate of Return [IRR] and the discounted payback [PBD] favored the acquisition of a combine harvester, which is the subject of the analysis of the proposed Net Cash Flow [FCL] of the proposed investment.

Mompox y el río grande de la Magdalena: Patrimonio cultural y natural de colombia y la humanidad

Directory of Open Access Journals (Sweden)

Franco Ossa Lucía Victoria

2011-11-01

Full Text Available El sistema estructurante urbano­regional de Mompox esta configurado por su arquitectura y el río Grande de la Magdalena, es decir, por su patrimonio cultural y ambiental. A su vez, Mompox constituye un hito estructurante del desarrollo regional, en el contexto histórico, urbano­ arquitectónico, ambiental y socio­cultural, y un referente importante de la memoria de la humanidad, en tanto está inscrito en la lista del patrimonio mundial desde 1995. La conservación, tutela y revitalización de estos hitos culturales y naturales dependen de estrategias sistémicas de valoración, planeamiento, gestión y educación de las valías patrim oniales culturales y ambientales de Mompox y la región. El objetivo de esta publicación es poner en valor el patrimonio de Mompox y del río Grande de la Magdalena, como ejes estructurantes de fundación, poblamiento y desarrollo urbano, y como marcas del paisaje y ejes de multiculturalidad y biodiversidad regional, a partir de la valoración de su historia, arquitectura y ambiente y la concepción del patrimonio com o sistema contenedor de la expresión humana en su íntima relación con el entorno. El patrimonio de Mompox es tratado desde su contexto histórico durante los períodos pre­hispánico, colonial y el más reciente el aprovechamiento de los recursos naturales y la actividad fluvial en los procesos de poblamiento y colonización española y la configuración urbana de la ciudad.

Reinventing Consumption Traditions through the Process of Unification of a Country: Understanding “Good Bye Lenin!”

Directory of Open Access Journals (Sweden)

Ece Ceren Engür

2016-02-01

Full Text Available This paper focuses on the change of consumption traditions in terms of re-unification of a country. The discussion bases on the movie, “Good Bye Lenin!”(2003 and chases the transformations on consumption trends in order to understand how the re-unification of East and West Germany influences the practices of everyday life after a four decade long segregation. The movie displays the 1990’s Germany during the times when the Berlin Wall falls and frames a family portrait which is dominated by an idealist and traditional mother character in the last days of her life.

Valoración comparativa de las tres grandes religiones (judaímo, cristianismo, islam) /

OpenAIRE

Aragón Zamora, Raúl

2013-01-01

Se realiza una valoración comparativa de las tres grandes religiones del mundo monoteístas: cristianismo, islam y judaísmo. De gran importancia en occidente, han influido en su historia, en sus costumbres, en sus tradiciones y manera de vivir. Se analizan las diferencias que hay entre ellas y se nos muestra cómo hoy en día siguen influyendo en la vida de muchas personas.

76 FR 15209 - 150th Anniversary of the Unification of Italy, 2011

Science.gov (United States)

2011-03-21

... fighting for the preservation of our own Union, Giuseppe Garibaldi's campaign for the unification of Italy... millions of American women and men of Italian descent who strengthen and enrich our Nation. Italy and the... thousand eleven, and of the Independence of the United States of America the two hundred and thirty-fifth...

THE UNIFICATION OF POWERFUL QUASARS AND RADIO GALAXIES AND THEIR RELATION TO OTHER MASSIVE GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Podigachoski, Pece; Barthel, Peter [Kapteyn Astronomical Institute, University of Groningen, 9747 AD Groningen (Netherlands); Haas, Martin [Astronomisches Institut, Ruhr Universität, D-44801 Bochum (Germany); Leipski, Christian [Max-Planck Institut für Astronomie (MPIA), D-69117 Heidelberg (Germany); Wilkes, Belinda, E-mail: podigachoski@astro.rug.nl [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

2015-06-10

The unification model for powerful radio galaxies (RGs) and radio-loud quasars postulates that these objects are intrinsically the same but viewed along different angles. Herschel Space Observatory data permit the assessment of that model in the far-infrared spectral window. We analyze photometry from Spitzer and Herschel for the distant 3CR hosts, and find that RGs and quasars have different mid-infrared, but indistinguishable far-infrared colors. Both these properties, the former being orientation dependent and the latter orientation invariant, are in line with expectations from the unification model. Adding powerful radio-quiet active galaxies and typical massive star-forming (SF) galaxies to the analysis, we demonstrate that infrared colors not only provide an orientation indicator, but can also distinguish active from SF galaxies.

THE UNIFICATION OF POWERFUL QUASARS AND RADIO GALAXIES AND THEIR RELATION TO OTHER MASSIVE GALAXIES

International Nuclear Information System (INIS)

Podigachoski, Pece; Barthel, Peter; Haas, Martin; Leipski, Christian; Wilkes, Belinda

2015-01-01

The unification model for powerful radio galaxies (RGs) and radio-loud quasars postulates that these objects are intrinsically the same but viewed along different angles. Herschel Space Observatory data permit the assessment of that model in the far-infrared spectral window. We analyze photometry from Spitzer and Herschel for the distant 3CR hosts, and find that RGs and quasars have different mid-infrared, but indistinguishable far-infrared colors. Both these properties, the former being orientation dependent and the latter orientation invariant, are in line with expectations from the unification model. Adding powerful radio-quiet active galaxies and typical massive star-forming (SF) galaxies to the analysis, we demonstrate that infrared colors not only provide an orientation indicator, but can also distinguish active from SF galaxies

Gauge-Higgs unification in higher dimensions

International Nuclear Information System (INIS)

Hall, Lawrence; Nomura, Yasunori; Smith, David

2002-01-01

The electroweak Higgs doublets are identified as components of a vector multiplet in a higher-dimensional supersymmetric field theory. We construct a minimal model in 6D where the electroweak SU(2)xU(1) gauge group is extended to SU(3), and unified 6D models with the unified SU(5) gauge symmetry extended to SU(6). In these realistic theories the extended gauge group is broken by orbifold boundary conditions, leaving Higgs doublet zero modes which have Yukawa couplings to quarks and leptons on the orbifold fixed points. In one SU(6) model the weak mixing angle receives power law corrections, while in another the fixed point structure forbids such corrections. A 5D model is also constructed in which the Higgs doublet contains the fifth component of the gauge field. In this case Yukawa couplings are introduced as nonlocal operators involving the Wilson line of this gauge field

Unification venoplasty to cope with recipient portal vein anomaly during living donor liver transplantation.

Science.gov (United States)

Kang, S-H; Hwang, S; Jung, D-H; Ahn, C-S; Moon, D-B; Ha, T-Y; Song, G-W; Kim, K-H; Park, G-C; Namgoong, J-M; Park, Y-H; Park, H-W; Jung, B-H; Lee, S-G

2013-10-01

To cope with recipient portal vein (PV) anomalies, such as early branching of the right posterior section (RPS), during living donor liver transplantation (LDLT) surgery, we performed a simulation study to standardize the surgical technique for unification portal venoplasty. This study included an observational analysis of conventional methods utilizing RPS PV, simulation-based design of a new surgical technique, and clinical application of this new technique. In a case encountering RPS PV, a mild anastomotic PV stenosis was persistent over 6 months postsurgery, indicating the need for technical refinement. After computational simulation analysis, we found that simple suturing of the PV branch patch automatically resulted in a funnel-shaped elongation. A prospective recipient study (n = 30) indicated that usual PV reconstruction via the PV bifurcation method is feasible in the absence of unusual donor or recipient PV anomaly. Retrospective living donor PV anatomy analysis (n = 20) revealed that 20-mm-long limbs of the first-order PV branches are necessary to make a 10- to l5-mm-long funneled PV stump. This technique of unification venoplasty for an anomalous recipient PV was applied to an adult patient undergoing LDLT with a right liver graft, for which it was shown to be technically feasible and effective. A simplified unification venoplasty technique was developed to cope with a recipient PV anomaly in adult LDLT. Copyright © 2013. Published by Elsevier Inc.

Real and imaginary elements of fermion mass matrices

International Nuclear Information System (INIS)

Masina, I.; Savoy, C.A.

2006-01-01

Prompted by the recent better determination of the angles of the unitarity triangle, we re-appraise the problem of finding simple fermion mass textures, possibly linked to some symmetry principle and compatible with grand unification. In particular, the indication that the angle α is close to rectangle turns out to be the crucial ingredient leading us to single out fermion mass textures whose elements are either real or purely imaginary. In terms of the five parameters ascribed to the quark sector, these textures reproduce the eight experimental data on quark mass ratios and mixings within 1σ. When embedded in an SU(5) framework, these textures suggest a common origin for quark and lepton CP violations, also linked to the spontaneous breaking of the gauge group

Neutrino tri-bi-maximal mixing from a non-Abelian discrete family symmetry

CERN Document Server

Varzielas, I M; Ross, Graham G

2007-01-01

The observed neutrino mixing, having a near maximal atmospheric neutrino mixing angle and a large solar mixing angle, is close to tri-bi-maximal. We argue that this structure suggests a family symmetric origin in which the magnitude of the mixing angles are related to the existence of a discrete non-Abelian family symmetry. We construct a model in which the family symmetry is the non-Abelian discrete group $\\Delta(27)$, a subgroup of $SU(3)$ in which the tri-bi-maximal mixing directly follows from the vacuum structure enforced by the discrete symmetry. In addition to the lepton mixing angles, the model accounts for the observed quark and lepton masses and the CKM matrix. The structure is also consistent with an underlying stage of Grand Unification.

On a radiative origin of the Standard Model from trinification

Science.gov (United States)

Camargo-Molina, José Eliel; Morais, António P.; Pasechnik, Roman; Wessén, Jonas

2016-09-01

In this work, we present a trinification-based grand unified theory incorporating a global SU(3) family symmetry that after a spontaneous breaking leads to a left-right symmetric model. Already at the classical level, this model can accommodate the matter content and the quark Cabbibo mixing in the Standard Model (SM) with only one Yukawa coupling at the unification scale. Considering the minimal low-energy scenario with the least amount of light states, we show that the resulting effective theory enables dynamical breaking of its gauge group down to that of the SM by means of radiative corrections accounted for by the renormalisation group evolution at one loop. This result paves the way for a consistent explanation of the SM breaking scale and fermion mass hierarchies.

Dynamical supersymmetry breaking

International Nuclear Information System (INIS)

Affleck, I.

1985-03-01

Supersymmetry, and in particular, dynamical supersymmetry breaking, offers the hope of a natural solution of the gauge hierarchy problem in grand unification. I briefly review recent work on dynamical supersymmetry breaking in four-dimensional Higgs theories and its application to grand unified model building

Higgs mass scales and matter-antimatter oscillations in grand unified theories

International Nuclear Information System (INIS)

Senjanovic, G.

1982-01-01

A general discussion of mass scales in grand unified theories is presented, with special emphasis on Higgs scalars which mediate neutron-antineutron (n-anti n) and hydrogen-antihydrogen (H-anti H) oscillations. It is shown that the analogue of survival hypothesis for fermions naturally makes such particles superheavy, thus leading to unobservable lifetimes. If this hypothesis is relaxed, an interesting possibility of potentially observable n-anti n and H-anti H transitions, mutually related arises in the context of SU(5) theory with spontaneously broken B-L symmetry

Group theory approach to unification of gravity with internal symmetry gauge interactions. Part 1

International Nuclear Information System (INIS)

Samokhvalov, S.E.; Vanyashin, V.S.

1990-12-01

The infinite group of deformed diffeomorphisms of space-time continuum is put into the basis of the Gauge Theory of Gravity. This gives rise to some new ways for unification of gravity with other gauge interactions. (author). 7 refs

Quantum numbers of anti-grand-unified-theory Higgs fields from the quark-lepton spectrum

International Nuclear Information System (INIS)

Froggatt, C.D.; Nielsen, H.B.; Smith, D.J.

2002-01-01

A series of Higgs field quantum numbers in the anti-grand-unification model, based on the gauge group SMG 3 xU(1) f , is tested against the spectrum of quark and lepton masses and mixing angles. A more precise formulation of the statement that the couplings are assumed of order unity is given. It is found that the corrections coming from this more precise assumption do not contain factors of the order of the number of colors, N c =3, as one could have feared. We also include a combinatorial correction factor, taking account of the distinct internal orderings within the chain Feynman diagrams in our statistical estimates. Strictly speaking our model predicts that the uncertainty in its predictions and thus the accuracy of our fits should be ±60%. Many of the best fitting quantum numbers give a higher accuracy fit to the masses and mixing angles, although within the expected fluctuations in a χ 2 . This means that our fit is as good as it can possibly be

Juan Eduardo Cirlot. Cuando la palabra y la letra llaman a su forma

Directory of Open Access Journals (Sweden)

Clara Janés

2014-03-01

Full Text Available Juan Eduardo Cirlot es uno de los grandes innovadores en el campo de la poesía del siglo XX española. Crítico de arte y ensayista, además de poeta y músico, su relación con la familia Buñuel le impulsa a ponerse en contacto con André Breton y los surrealistas de París. Incorpora las técnicas tanto surrealistas como Dadá, pero va mucho más lejos. Su conocimiento de la música contemporánea que adopta el serialismo de Schönberg, el cual parte de la Cabala hebraica -que él transforma en la poesía permutatoria-, su atrevimiento al aproximarse a las antiguas fórmulas mágicas egipcias, sus hallazgos fono-visuales le llevan a cubrir el abanico más amplio y atrevido de la vanguardia hispana de su tiempo.

Softening the supersymmetric flavor problem in orbifold grand unified theories

International Nuclear Information System (INIS)

Kajiyama, Yuji; Terao, Haruhiko; Kubo, Jisuke

2004-01-01

The infrared attractive force of the bulk gauge interactions is applied to soften the supersymmetric flavor problem in the orbifold SU(5) grand unified theory of Kawamura. Then this force aligns in the infrared regime the soft supersymmetry breaking terms out of their anarchical disorder at a fundamental scale, in such a way that flavor-changing neutral currents as well as dangerous CP-violating phases are suppressed at low energies. It is found that this dynamical alignment is sufficiently good compared with the current experimental bounds, as long as the diagonalization matrices of the Yukawa couplings are CKM-like

A comment on the quark mixing in the supersymmetric SU(4)xO(4) GUT model

International Nuclear Information System (INIS)

Ranfone, S.

1992-08-01

The SU(4) x O(4) and the ''flipped'' SU(5) x U(1) models seem to be the only possible Grand Universal Theories (GUT's) derivable from string theories with Kac-Moody level K=1. Naively, the SU(4) x O(4) model, at least in its minimal GUT version, is characterized by the lack of any mixing in the quark sector. In this ''Comment'' we show that, although some mixing may be generated as a consequence of large vacuum-expectation-values for the scalar partners of the right-handed neutrinos, it turns out to be too small by several orders of magnitude, in net contrast with our experimental information concerning the Cabibbo mixing. Our result, which therefore rules out the minimal SU(4) x O(4) GUT model, also applies to ''flipped'' SU(5) x U(1) in the case of the embedding in SO(10). (Author)

Grand Fir Nutrient Management in the Inland Northwestern USA

Directory of Open Access Journals (Sweden)

Dennis R. Parent

2016-11-01

Full Text Available Grand fir (Abies grandis (Douglas ex D. Don Lindley is widely distributed in the moist forests of the Inland Northwest. It has high potential productivity, its growth being nearly equal to western white pine, the most productive species in the region. There are large standing volumes of grand fir in the region. Nutritionally, the species has higher foliage cation concentrations than associated conifers, especially potassium (K and calcium (Ca. In contrast, it has lower nitrogen (N foliage concentrations, which creates favorable nutrient balance on N-limited sites. Despite concentration differences, grand fir stores proportionally more nutrients per tree than associated species because of greater crown biomass. Although few fertilization trials have examined grand fir specifically, its response is inferred from its occurrence in many monitored mixed conifer stands. Fertilization trials including grand fir either as a major or minor component show that it has a strong diameter and height growth response ranging from 15% to 50% depending in part on site moisture availability and soil geology. Grand fir tends to have a longer response duration than other inland conifers. When executed concurrently with thinning, fertilization often increases the total response. Late rotation application of N provides solid investment returns in carefully selected stands. Although there are still challenges with the post-fertilization effects on tree mortality, grand fir will continue to be an important species with good economic values and beneficial responses to fertilization and nutrient management.

Raptor Use of the Rio Grande Gorge

Energy Technology Data Exchange (ETDEWEB)

Ponton, David A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-03-20

The Rio Grande Gorge is a 115 km long river canyon located in Southern Colorado (15 km) and Northern New Mexico (100 km). The majority of the canyon is under the administration of the Bureau of Land Management {BLM), and 77 km of the canyon south of the Colorado/New Mexico border are designated Wild River under the National Wild and Scenic Rivers Act of 1968. Visits I have made to the Rio Grande Gorge over the past 15 .years disclosed some raptor utilization. As the Snake River Birds of Prey Natural Area gained publicity, its similarity to the Rio Grande Gorge became obvious, and I was intrigued by the possibility of a high raptor nesting density in the Gorge. A survey in 1979 of 20 km of the northern end of the canyon revealed a moderately high density of red-tailed hawks and prairie falcons. With the encouragement of that partial survey, and a need to assess the impact of river-running on nesting birds of prey, I made a more comprehensive survey in 1980. The results of my surveys, along with those of a 1978 helicopter survey by the BLM, are presented in this report, as well as general characterization of the area, winter use by raptors, and an assessment of factors influencing the raptor population.

INTRODUCTION A L'UNIFICATION DES INTERACTIONS ELECTROMAGNETIQUES ET FAIBLES

OpenAIRE

Martin , F.

1980-01-01

Après avoir décrit l'état actuel de la phénoménologie des interactions faibles on discute les principes de base des théories de jauge. On montre ensuite comment le mécanisme de Higgs permet d'obtenir des quanta d'interaction massifs. Le modèle dit de "Weinberg-Salam" permettant d'unifier les interactions électromagnétiques et faibles est présenté. On termine par quelques mots sur l'unification avec les interactions fortes et la gravitation.

Interplay between grand unification and supersymmetry in

Indian Academy of Sciences (India)

2016-01-21

Jan 21, 2016 ... Proceedings of the International Workshop/Conference on Computational Condensed Matter Physics and Materials Science (IWCCMP-2015). Posted on November 27, 2015. Guest Editors: Anurag Srivastava, C. S. Praveen, H. S. Tewari. © 2015 Indian Academy of Sciences, Bengaluru. Contact | Site index.

Grand unification in the heterotic brane world

International Nuclear Information System (INIS)

Vaudrevange, Patrick Karl Simon

2008-08-01

String theory is known to be one of the most promising candidates for a uni ed description of all elementary particles and their interactions. Starting from the ten-dimensional heterotic string, we study its compactification on six-dimensional orbifolds. We clarify some important technical aspects of their construction and introduce new parameters, called generalized discrete torsion. We identify intrinsic new relations between orbifolds with and without (generalized) discrete torsion. Furthermore, we perform a systematic search for MSSM-like models in the context of Z 6 -II orbifolds. Using local GUTs, which naturally appear in the heterotic brane world, we construct about 200 MSSM candidates. We find that intermediate SUSY breaking through hidden sector gaugino condensation is preferred in this set of models. A specific model, the so-called benchmark model, is analyzed in detail addressing questions like the identification of a supersymmetric vacuum with a naturally small μ-term and proton decay. Furthermore, as vevs of twisted fields correspond to a resolution of orbifold singularities, we analyze the resolution of Z 3 singularities in the local and in the compact case. Finally, we exemplify this procedure with the resolution of a Z 3 MSSM candidate. (orig.)

Physics and cosmology - geometry for grand unification

International Nuclear Information System (INIS)

Heller, M.

1985-01-01

Fibre bundle technique to geometrize gauge field theories and possibly to unify physics is presented on the introductory level. Some remarks are made concerning the mutual relationship between physics and cosmology. 21 refs., 10 figs. (author)

Grand unification in the heterotic brane world

Energy Technology Data Exchange (ETDEWEB)

Vaudrevange, Patrick Karl Simon

2008-08-15

String theory is known to be one of the most promising candidates for a uni ed description of all elementary particles and their interactions. Starting from the ten-dimensional heterotic string, we study its compactification on six-dimensional orbifolds. We clarify some important technical aspects of their construction and introduce new parameters, called generalized discrete torsion. We identify intrinsic new relations between orbifolds with and without (generalized) discrete torsion. Furthermore, we perform a systematic search for MSSM-like models in the context of Z{sub 6}-II orbifolds. Using local GUTs, which naturally appear in the heterotic brane world, we construct about 200 MSSM candidates. We find that intermediate SUSY breaking through hidden sector gaugino condensation is preferred in this set of models. A specific model, the so-called benchmark model, is analyzed in detail addressing questions like the identification of a supersymmetric vacuum with a naturally small {mu}-term and proton decay. Furthermore, as vevs of twisted fields correspond to a resolution of orbifold singularities, we analyze the resolution of Z{sub 3} singularities in the local and in the compact case. Finally, we exemplify this procedure with the resolution of a Z{sub 3} MSSM candidate. (orig.)

Características e frequência das doenças de suínos na Região Central do Rio Grande do Sul

Directory of Open Access Journals (Sweden)

Juliana S. Brum

2013-10-01

Full Text Available Visando-se determinar as características e frequência das doenças na população suína na região de abrangência do Laboratório de Patologia Veterinária (LPV da Universidade Federal de Santa Maria (UFSM, foi realizado um estudo retrospectivo de todos os diagnósticos de necropsias realizadas nesta espécie no período de 1964 a 2011. Foram separados 564 casos com diagnósticos conclusivos. A criação suína na região de abrangência do estudo é predominantemente familiar e as doenças diagnosticadas, refletem esta realidade. As doenças infecciosas e parasitárias foram as mais prevalentes [380(68,1%], seguidas, em ordem decrescente, das doenças metabólicas e nutricionais [64(11,5%], intoxicações e toxi-infecções [33(5,9%], e distúrbios do desenvolvimento [15(2,7%]. Outras alterações de diversas etiologias, sobretudo de trauma, foram causa de morte em pouco mais de 11% dos protocolos examinados. Doenças bacterianas foram responsáveis por mais da metade das causas de morte ou razão para eutanásia dos suínos estudados, revelando a influência de fatores de manejo, ambientais e nutricionais regional de criação de suínos. A principal doença diagnosticada em suínos na região de abrangência do estudo foi a doença do edema e juntamente com outras formas de infecção por Escherichia coli é responsável por 23% das mortes. Doenças de etiologia viral e neoplasia não são importantes causas de morte em suínos na região estudada. Hepatose nutricional e aflatoxicose são importantes doenças da região e se devem, sobretudo, a fatores de manejo nutricional.

Introduction to unified theories of weak, electromagnetic and strong interactions - SU(5)

International Nuclear Information System (INIS)

Billoire, Alain; Morel, Andre.

1980-11-01

These notes correspond to a series of lectures given at Salay during winter 1979-1980. They are meant to be an introduction to the so-called grand unified theories of weak, electromagnetic and strong interactions. In a first part, we recall in a very elementary way the standard SU(2) model of electroweak interactions, putting the emphasis on the questions which are left open by this model and which unified theories help to answer. In part II, we explain in a systematic way how unified theories can be constructed, and develop the SU(5) model in great detail. Other models, like SO(10) and E 6 , are not presented, because SU(5) is the simplest one and has been subject to the deepest investigations up to now. Also it appears that most concepts and general results are not specific to any particular symmetry group [fr

Building a Larger Tent for Public Health: Implications of the SOPHE-AAHE Unification

Science.gov (United States)

Goodman, Robert Mark

2013-01-01

The unification of the American Association for Health Education (AAHE) and the Society for Public Health Education (SOPHE) generates a long-desired synergy, a ramping up of our leadership influence in promoting health. It also serves as an ongoing opportunity to reflect on how we synergize the distinct philosophic, scientific, and practical…

Electroweak unification and tree unitarity

International Nuclear Information System (INIS)

Horejsi, J.

1993-01-01

The monograph is an unconventional introduction into the theory of unification of weak and electromagnetic interactions, which is conceptually different from the exposition presented in standard textbooks. A detailed explanation is given of the way to the standard model of electroweak interactions which is based on a straightforward application of the requirement of renormalizability of the perturbation series expansion. The procedure to derive the model is interesting as it demonstrates the necessity of introducing vector bosons and Yang-Mills type interactions and at least one elementary scalar boson to obtain a renormalizable theory of weak and electromagnetic interactions. The book is divided into 5 chapters: introduction, problems encountered in a Fermi type theory, the intermediate vector boson, electrodynamics of vector bosons, tree unitarity, and electroweak interactions. Each chapter is completed with exercise problems to be solved by the reader. The text is supplemented with a number of appendices. The monograph is aimed at undergraduate and postgraduate students as well as at physicists interested in the theory of elementary particles. (Z.J.)

Lycalopex culpaeus reissii, el segundo cánido más grande de Sudamérica

Directory of Open Access Journals (Sweden)

Domenica Garzón

2017-08-01

Full Text Available Lycalopex culpaeus reissii es una subespecie del Lycalopex Culpaeus perteneciente a la familia Canidae. El culpaeus es el segundo cánido más grande de América del Sur. En Ecuador, se localiza principalmente en los páramos, estepas y bosques como los de la reserva Antisana y en el Bosque Jerusalén. Es un animal tímido y solitario que se distingue por su pelaje rojizo, y su cráneo prolongado. Suele mantener una pareja estable para la reproducción y cuidado de las crías. Su alimentación es muy variada pero principalmente se constituye de mamíferos más pequeños. Actualmente, sus principales amenazas son el ser humano, esencialmente porque se considera que este lobo es perjudicial para el ganado, y la depredación por perros domésticos y salvajes, así como su adquisición de enfermedades parasitarias. Además, las investigaciones centradas en esta subespecie son escasas en el país.

Quarks and leptons

International Nuclear Information System (INIS)

Harari, H.

1977-01-01

The physics of quarks and leptons within the framework of gauge theories for the weak and electromagnetic interactions is reviewed. The Weinberg-Salam SU(2)xU(1) theory is used as a ''reference point'' but models based on larger gauge groups, especially SU(2)sub(L)xSU(2)sub(R)xU(1), are discussed. We distinguish among three ''Generations'' of fundamental fermions: The first generation (e - , νsub(e), u, d), the second generation (μ - , νsub(μ), c, s) and the third generation (tau - , νsub(tau), t, b). For each generation are discussed the classification of all fermions, the charged and neutral weak currents, possible right-handed currents, parity and CP-violation, fermion masses and Cabibbo-like angles and related problems. Theoretical ideas as well as experimental evidence, emphasizing open theoretical problems and possible experimental tests are reviewed, as well as the possibility of unifying the weak, electromagnetic and strong interactions in a grand unification scheme. The problems and their possible solutions are presented, generation by generation, but a brief subject-index (following the table of contents) enbales the interested reader to follow any specific topic throughout the three generations. (author)

Threshold corrections to dimension-six proton decay operators in non-minimal SUSY SU(5 GUTs

Directory of Open Access Journals (Sweden)

Borut Bajc

2016-09-01

Full Text Available We calculate the high and low scale threshold corrections to the D=6 proton decay mode in supersymmetric SU(5 grand unified theories with higher-dimensional representation Higgs multiplets. In particular, we focus on a missing-partner model in which the grand unified group is spontaneously broken by the 75-dimensional Higgs multiplet and the doublet–triplet splitting problem is solved. We find that in the missing-partner model the D=6 proton decay rate gets suppressed by about 60%, mainly due to the threshold effect at the GUT scale, while the SUSY-scale threshold corrections are found to be less prominent when sfermions are heavy.

Korean Unification and the Future of the U.S.-ROK Alliance

Science.gov (United States)

2016-02-01

including the Korean People’s Army, which, by ROK estimates, numbers 1.2 million in the active force and some 7.7 million in the reserve , or...management. A broader alli- ance agenda would also place a premium on establishing an interagency or whole-of-government dialogue, fusing together...annualized gross domestic product (GDP). See Christine Kim, “Korean Unification May Cost South 7 Percent of GDP: Ministry,” Reuters, January 1, 2013

Reformulating XQuery queries using GLAV mapping and complex unification

Directory of Open Access Journals (Sweden)

Saber Benharzallah

2016-01-01

Full Text Available This paper describes an algorithm for reformulation of XQuery queries. The mediation is based on an essential component called mediator. Its main role is to reformulate a user query, written in terms of global schema, into queries written in terms of source schemas. Our algorithm is based on the principle of logical equivalence, simple and complex unification, to obtain a better reformulation. It takes XQuery query, global schema (written in XMLSchema, and mappings GLAV as input parameters and provides resultant query written in terms of source schemas. The results of implementation show the proper functioning of the algorithm.

Technicolor and Beyond: Unification in Theory Space

DEFF Research Database (Denmark)

Sannino, Francesco

2010-01-01

The salient features of models of dynamical electroweak symmetry breaking are reviewed. The ideal walking idea is introduced according to which one should carefully take into account the effects of the extended technicolor dynamics on the technicolor dynamics itself. The effects amount at the enh......The salient features of models of dynamical electroweak symmetry breaking are reviewed. The ideal walking idea is introduced according to which one should carefully take into account the effects of the extended technicolor dynamics on the technicolor dynamics itself. The effects amount...... supersymmetry and technicolor. The reason is to provide a unification of different extensions of the standard model. For example, this means that one can recover, according to the parameters and spectrum of the theory distinct extensions of the standard model, from supersymmetry to technicolor and unparticle...

La acuicultura y su impacto al medio ambiente

Directory of Open Access Journals (Sweden)

Angélica Espinosa Plascencia

2012-01-01

Full Text Available En el noroeste de México la producción de camarón cultivado es considerada como una de las más importantes de América Latina. Sin embargo, se presentan grandes pérdidas económicas asociadas a enfermedades durante su cultivo, aunado a la intervención intensiva que generan las prácticas acuícolas que van degradando el medio ambiente. Esto es, primero, por la utilización del agua que recibe grandes cantidades de desechos, así como el alimento no consumido por los organismos que se sedimenta en el fondo marino, dañando al ambiente que es habitado no solo por los organismos cultivados sino también por otras especies. Segundo, porque se introducen antibióticos y sustancias químicas al ecosistema durante el desarrollo de la actividad. Por ello, fue necesario evaluar el efecto de un antibiótico y un biocida sobre las bacterias que habitan un sistema de cultivo, en relación al desarrollo de resistencia y la presencia de lesiones en los distintos órganos de camarón Litopenaeus vannamei. El empleo de los compuestos puede generar una huella ecológica, ya que se considera que un sistema de cultivo tiene una influencia en el medio ambiente diez mil veces superior a su superficie. El impacto tiene un costo ambiental, económico y social y la pregunta que surge es si esto es sustentable en el tiempo.

Special Issue: 15 Years of SU8 as MEMS Material

Directory of Open Access Journals (Sweden)

Arnaud Bertsch

2015-06-01

Full Text Available In 1997, the first paper using SU-8 as a material for microfabrication was published [1], demonstrating the interest of this negative photoresist for the near-UV structuration of thick layers and the manufacturing of high aspect-ratio components.[...

Squark and slepton masses as probes of supersymmetric SO(10) unification

Energy Technology Data Exchange (ETDEWEB)

Balasubramanian Ananthanarayan; P. N. Pandita

2003-09-01

We carry out a detailed analysis of the non-universal supersymmetry breaking scalar masses arising in SO(10) supersymmetric unification. By considering patterns of squark and slepton masses, we show that a set of sum rules for the sfermion masses is independent of the manner in which SO(10) breaks. We discuss the reasons for this remarkable result. The phenomenology arising from such non-universality is shown to be practically unaffected by the symmetry breaking pattern.

Physics beyond the standard model in the non-perturbative unification scheme

International Nuclear Information System (INIS)

Kapetanakis, D.; Zoupanos, G.

1990-01-01

The non-perturbative unification scenario predicts reasonably well the low energy gauge couplings of the standard model. Agreement with the measured low energy couplings is obtained by assuming certain kind of physics beyond the standard model. A number of possibilities for physics beyond the standard model is examined. The best candidates so far are the standard model with eight fermionic families and a similar number of Higgs doublets, and the supersymmetric standard model with five families. (author)

Charles Fourier y la educación de su época: Crítica y propuesta

Directory of Open Access Journals (Sweden)

Diego SEVILLA MERINO

2010-03-01

Full Text Available RESUMEN: El pensamiento utópico, liberado de una interpretación dépréciât iva que lo identificaba con fábula y quimera y lo confundía con la expresión literaria más frecuentemente adoptada por él, ha demostrado ser un «modo específico de conocer la realidad a través de su proyección ideal de la misma». Cuando nos acercamos a los grandes utopistas, encontramos crítica ante las limitaciones e injusticias que advierten en la sociedad de su tiempo y proyectos con los que buscan su superación. De este modo, el pensamiento toma las situaciones reales como un negativo con el que se logrará, por su modificación e inversión, un orden social más justo.

Random dynamics and relations between the number of fermion generations and the fine structure

International Nuclear Information System (INIS)

Nielsen, H.B.

1989-01-01

By looking at the structure and crude features of the parameters of the Standard Model we argue for some properties of physics at a more fundamental level, presumably the Planck energy scale. These properties suggest a picture of 'anti-grand-unification' in the sense that, contrary to usual grand unification, we do not expect a simple gauge group at the high energy level. Rather we expect to see a gauge algebra which is a cross product of several simple or abelian factors. A symmetry breaking mechanism called confusion may then break each set of isomorphic factors down to the diagonal subgroup, thereby explaining the fact that non of the direct product factors in the Standard Model are repeated. (orig.)

A proposal for unification of fatigue crack growth law

Science.gov (United States)

Kobelev, V.

2017-05-01

In the present paper, the new fractional-differential dependences of cycles to failure for a given initial crack length upon the stress amplitude in the linear fracture approach are proposed. The anticipated unified propagation function describes the infinitesimal crack length growths per increasing number of load cycles, supposing that the load ratio remains constant over the load history. Two unification fractional-differential functions with different number of fitting parameters are proposed. An alternative, threshold formulations for the fractional-differential propagation functions are suggested. The mean stress dependence is the immediate consequence from the considered laws. The corresponding formulas for crack length over the number of cycles are derived in closed form.

A Layman's guide to SUSY GUTs

CERN Document Server

López, Jorge L; Zichichi, A

1994-01-01

The determination of the most straightforward evidence for the existence of the Superworld requires a guide for non-experts (especially experimental physicists) for them to make their own judgement on the value of such predictions. For this purpose we review the most basic results of Super-Grand unification in a simple and clear way. We focus the attention on two specific models and their predictions. These two models represent an example of a direct comparison between a traditional unified-theory and a string-inspired approach to the solution of the many open problems of the Standard Model. We emphasize that viable models must satisfy {\\em all} available experimental constraints and be as simple as theoretically possible. The two well defined supergravity models, $SU(5)$ and $SU(5)\\times U(1)$, can be described in terms of only a few parameters (five and three respectively) instead of the more than twenty needed in the MSSM model, \\ie, the Minimal Supersymmetric extension of the Standard Model. A case of spe...

Elementary particle theory

International Nuclear Information System (INIS)

Marciano, W.J.

1984-12-01

The present state of the art in elementary particle theory is reviewed. Topics include quantum electrodynamics, weak interactions, electroweak unification, quantum chromodynamics, and grand unified theories. 113 references

Low energy gauge couplings in grand unified theories and high precision physics

International Nuclear Information System (INIS)

Lynn, B.W.

1993-09-01

I generalize the leading log relations between low energy SU(3) QCD , SU(2) rvec I and U(l) Y effective gauge couplings to include all one-loop threshold effects of matter fields in oblique vector self energy quantum corrections for both supersymmetric and non-supersymmetric SU(5) grand unified theories. These always involve an exactly conserved current from the unbroken SU(3) QCD x U(L) QED subgroup; this fact strongly constrains any non-decoupling of heavy states as well as the generic character of threshold effects. Relations between low energy gauge couplings depend on the details of the spectra of both the superheavy and low mass sectors; I display the common origin of the logs appropriate to superheavy matter states, which can be found with well known renormalization group techniques, and the combination of logs and polynomials appropriate for light matter states, which cannot. Relations between any two or all three low energy effective gauge couplings do not depend on the top quark or standard model Higgs' masses. Neither do they depend on neutral color singlet states such as other neutral color singlet Higgs' or higgsinos, neutrinos, zinos or photinos. Further, they do not depend on degenerate SU(5) matter representations, of either spin 0 or spin 1/2 of any mass; matter representations of SU(5) can affect such relations only if there is mass splitting within them. The b quark splitting from the τ and ν τ can affect the relation between gauge couplings for |q 2 | → m b 2 as can hadronic resonances and multi-hadron states for lower |q 2 |. New mass-split representations of light states, such as occur in supersymmetric theories, can also affect such relations

Low energy gauge couplings in grand unified theories and high precision physics

Energy Technology Data Exchange (ETDEWEB)

Lynn, B.W. [Stanford Univ., CA (United States). Dept. of Physics]|[Superconducting Super Collider Lab., Dallas, TX (United States)

1993-09-01

I generalize the leading log relations between low energy SU(3){sub QCD}, SU(2){sub {rvec I}} and U(l){sub Y} effective gauge couplings to include all one-loop threshold effects of matter fields in oblique vector self energy quantum corrections for both supersymmetric and non-supersymmetric SU(5) grand unified theories. These always involve an exactly conserved current from the unbroken SU(3){sub QCD} {times} U(L){sub QED} subgroup; this fact strongly constrains any non-decoupling of heavy states as well as the generic character of threshold effects. Relations between low energy gauge couplings depend on the details of the spectra of both the superheavy and low mass sectors; I display the common origin of the logs appropriate to superheavy matter states, which can be found with well known renormalization group techniques, and the combination of logs and polynomials appropriate for light matter states, which cannot. Relations between any two or all three low energy effective gauge couplings do not depend on the top quark or standard model Higgs` masses. Neither do they depend on neutral color singlet states such as other neutral color singlet Higgs` or higgsinos, neutrinos, zinos or photinos. Further, they do not depend on degenerate SU(5) matter representations, of either spin 0 or spin 1/2 of any mass; matter representations of SU(5) can affect such relations only if there is mass splitting within them. The b quark splitting from the {tau} and {nu}{sub {tau}} can affect the relation between gauge couplings for {vert_bar}q{sub 2}{vert_bar} {yields} m{sub b}{sup 2} as can hadronic resonances and multi-hadron states for lower {vert_bar}q{sub 2}{vert_bar}. New mass-split representations of light states, such as occur in supersymmetric theories, can also affect such relations.

Pericardite em suínos ao abate no Rio Grande Sul: avaliação de agentes bacterianos e lesões associadas

Directory of Open Access Journals (Sweden)

Carolini F. Coelho

2014-07-01

Full Text Available O objetivo do presente estudo foi identificar a frequência de lesões macroscópicas e microscópicas e dos agentes bacterianos envolvidos em pericardites em suínos no abate no Estado do Rio Grande do Sul. As amostras foram coletadas em frigoríficos de suínos com Serviço de Inspeção Federal (SIF entre fevereiro a outubro de 2010 e a condenação por pericardite dos animais acompanhados foi de 3,9% (299/7.571. No total foram investigados 91 casos de pericardites, 89% deles foram classificados como crônicos por histopatologia e pleurite crônica foi observada em 47% dos pulmões correspondentes, todavia não houve associação significativa entre as duas lesões. Os agentes bacterianos isolados a partir dos corações foram Streptococcus spp., Pasteurella multocida, Haemophilus parasuis e Streptococcus suis. DNA bacterianos mais detectados pela PCR foram de Mycoplasma hyopneumoniae e Actinobacillus pleuropneumoniae. Houve associação significativa entre isolamento de P. multocida e Streptococcus sp. nos corações e pulmões correspondentes. Esses resultados sugerem que a infecção no pulmão possa ter servido de porta de entrada para a colonização do pericárdio adjacente. Apesar de M. hyopneumoniae ter sido o agente detectado com maior frequência pela PCR em corações e pulmões correspondentes, não houve associação significativa da detecção dos agentes nos órgãos. Isto sugere que as infecções foram eventos independentes. Os demais agentes investigados não apresentaram associação significativa entre isolamento ou detecção de DNA em coração e pulmão correspondente. Outro achado importante foi a presença de coinfecções bacterianas em 2% dos corações e por PCR foi detectado DNA bacteriano de dois ou mais agentes em 16,5% dos corações. Esses resultados sugerem que as coinfecções em pericardites precisam ser melhor estudadas.

Minimal supersymmetric grand unified theory: Symmetry breaking and the particle spectrum

International Nuclear Information System (INIS)

Bajc, Borut; Melfo, Alejandra; Senjanovic, Goran; Vissani, Francesco

2004-01-01

We discuss in detail the symmetry breaking and related issues in the minimal renormalizable supersymmetric grand unified theory. We find all the possible patterns of symmetry breaking, compute the associated particle spectrum and study its impact on the physical scales of the theory. In particular, the complete mass matrices of the SU(2) doublets and the color triplets are computed in connection with the doublet-triplet splitting and the d=5 proton decay. We explicitly construct the two light Higgs doublets as a function of the Higgs superpotential parameters. This provides a framework for the analysis of phenomenological implications of the theory, to be carried out in a second paper

Interpreting mathematics in physics: Charting the applications of SU(2) in 20th century physics

International Nuclear Information System (INIS)

Anderson, Ronald; Joshi, G.C.

2008-01-01

The role mathematics plays within physics has been of sustained interest for physicists as well as for philosophers and historians of science. We explore this topic by tracing the role the mathematical structure associated with SU(2) has played in three key episodes in 20th century physics - intrinsic spin, isospin, and gauge theory and electroweak unification. We also briefly consider its role in loop quantum gravity. Each episode has led to profound and new physical notions of a space other than the traditional ones of space and spacetime, and each has had associated with it a complex and in places, contested history. The episodes also reveal ways mathematical structures provide resources for new physical theorizing and we propose our study as a contribution to a need Roger Penrose has identified to develop a 'profoundly sensitive aesthetic' sense for locating physically relevant mathematics

How European unification has shaped the debate on measuring international financial integration

OpenAIRE

Pieterse-Bloem, Mary; Eijffinger, Sylvester

2013-01-01

textabstractIn this paper we analyse a chronicle of economic theory on international financial integration post-WWII to the present date. Our focus is on theories that have somehow quantify the state and speed of international financial integration. We are able to contrast and compare three distinct strands that have brought forward conditions for its measurement. It is shown that European unification provides much of the empirical testing ground for these measures of international financial ...

Network Dependency in Migration Flows – A Space-time Analysis for Germany since Re-unification

DEFF Research Database (Denmark)

Mitze, Timo

The contribution of this paper is to analyse the role of network interdependencies in a dynamic panel data model for German internal migration fl ows since re-unification. So far, a capacious account of spatial patterns in German migration data is still missing in the empirical literature. In the...

Para la investigación de estructuras grandes, procesos amplios y comparaciones

Directory of Open Access Journals (Sweden)

EMILIO CASTILLA

1992-01-01

Full Text Available A lo largo del siglo XIX, grandes cambios sociales, políticos y económicos (y su incomprensión crean el contexto idóneo para el surgimiento de un aparato científico-ideológico peculiar con el que analizar y explicar esa compleja realidad del momento. En el artículo se presenta un análisis crítico de los modelos de estudio adoptados por las Ciencias Sociales para la investigación de grandes estructuras y procesos sociales, muchos de los cuales siguen siendo utilizados en análisis contemporáneos. Se propone un modelo alternativo (un programa de interpretación social que promueva la comparación sistemática y crítica, y el análisis con base histórica. Este innovador método descarta las generalizaciones como objeto último del estudio social en un intento de comprender los procesos de modernización de las últimas décadas.

Heterotic brane world

International Nuclear Information System (INIS)

Nilles, H.-P.

2004-01-01

Heterotic E 8 x E 8 string theory is a promising source of grand unified model building. It can accommodate the successful aspects of grand unification while avoiding problems like doublet-triplet splitting in the Higgs sector and fast proton decay. We exploit the geometrical properties of the theory as a guideline for realistic model building. (author)

Natural supersymmetry and unification in five dimensions

Energy Technology Data Exchange (ETDEWEB)

Abdalgabar, Ammar [National Institute for Theoretical Physics and School of Physics and Mandelstam Institute for Theoretical Physics, University of the Witwatersrand,Private Bag 3, Wits, 2050 (South Africa); Department of Physics, Sudan University of Science and Technology,Khartoum, 407 (Sudan); Cornell, Alan S. [National Institute for Theoretical Physics and School of Physics and Mandelstam Institute for Theoretical Physics, University of the Witwatersrand,Private Bag 3, Wits, 2050 (South Africa); Deandrea, Aldo [Université de Lyon,92, rue Pasteur, Lyon, F-69361 (France); IPNL, Université Lyon 1, CNRS/IN2P3,4 rue Fermi, Villeurbanne Cedex, F-69622 (France); Institut Universitaire de France,103 boulevard Saint-Michel, Paris, 75005 (France); McGarrie, Moritz [Faculty of Physics, University of Warsaw,Hoża 69, Warsaw, 00-681 (Poland)

2016-01-14

We explore unification and natural supersymmetry in a five dimensional extension of the standard model in which the extra dimension may be large, of the order of 1–10 TeV. Power law running generates a TeV scale A{sub t} term allowing for the observed 125 GeV Higgs and allowing for stop masses below 2 TeV, compatible with a natural SUSY spectrum. We supply the full one-loop RGEs for various models and use metastability to give a prediction that the gluino mass should be lighter than 3.5 TeV for A{sub t}≥−2.5 TeV, for such a compactification scale, with brane localised 3rd generation matter. We also discuss models in which only the 1st and 2nd generation of matter fields are located in the bulk. We also look at electroweak symmetry breaking in these models.

Towards worldwide height unification using ocean information

Directory of Open Access Journals (Sweden)

P. L. Woodworth

2015-03-01

Full Text Available This paper describes how we are contributing to worldwide height system unification (WHSU by using ocean models together with sea level (tide gauge and altimeter information, geodetic (GPS and levelling data, and new geoid models based on information from the GRACE and GOCE gravity missions, to understand how mean sea level (MSL varies from place to place along the coast. For the last two centuries, MSL has been used to define datums for national levelling systems. However, there are many problems with this. One consequence of WHSU will be the substitution of conventional datums as a reference for heights with the use of geoid, as the only true "level" or datum. This work is within a number of GOCE-related activities funded by the European Space Agency. The study is focused on the coastlines of North America and Europe where the various datasets are most copious.

Literatura y filmicidad: El vocabulario de los balcones (Almudena Grandes, 1998 en Aunque tú no lo sepas (Juan Vicente Córdoba, 2000

Directory of Open Access Journals (Sweden)

Bonilla Cerezo, Rafael

2004-06-01

Full Text Available In the tales and narrative collections of the Spanish writers, different arts and genres can be encountered. This article focuses upon the study of one dialogue between El vocabulario de los balcones, published by Almudena Grandes in 1998, and Aunque tú no lo sepas (2000, the debut of Juan Vicente Córdoba as director. Because the Grandes' tale has a very filmic language: flashbacks, cuts, flashforwards and almost the steady cam. Here, I study the development and influences in this opera prima where Córdoba shows the effects of his light over the words.En los cuentos y colecciones narrativas de nuestro país prolifera el diálogo entre los diversos géneros, escuelas y medios expresivos. Este artículo pone de manifiesto la causalidad y el proceso de reescritura —o adaptación— fílmica de un relato breve de Almudena Grandes, El vocabulario de los balcones (1998, en una película de Juan Vicente Córdoba: Aunque tú no lo sepas (2000. Porque la historia de la autora madrileña posee, en el fondo, un lenguaje puramente fílmico: flashbacks, cuts, flashforwards e incluso un moderado uso de la steady cam. Estudio, pues, su desarrollo e influencias en esta opera prima donde Córdoba expone el efecto de su luz sobre las palabras.

El fiscal Roa Bastos: escenas del “Cristo paraguayo” y su guerra grande

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Paco Tovar

2015-07-01

Full Text Available In 1993, Augusto RoaBastos published El fiscal, a novel in which he revisits a moment in Paraguay’s contemporary history, offering, from a contemporary perspective opposed to Alfredo Stroessner’s dictatorship, a view to la Guerra Grande, marshall SolanoLópez and Doña Elisa Lynch. History and caracters shaped to some Félix Moral taste, get their final shape in an unfinished script, faithfull to the deeds, as describing another version of the reality for a failed film production about the same theme and a melodramatic atmosphere. That configuration, as well as a third one as an historical point of view from R. F. Burton, can be seen in Mathias Grünewald’s paintings and Cándido López’s works. All as a fiction that includes a testimonial nature, literary dimension and symbolic value.

Towards Unification of Methods for Speech, Audio, Picture and Multimedia Quality Assessment

DEFF Research Database (Denmark)

Zielinski, S.; Rumsey, F.; Bech, Søren

2015-01-01

attempting to “bridge the gap” between the quality assessment methods used in various disciplines are indicated. Prospective challenges faced by researchers in the unification process are outlined. They include development of unified scales, defining unified anchors, integration of objective models......The paper addresses the need to develop unified methods for subjective and objective quality assessment across speech, audio, picture, and multimedia applications. Commonalities and differences between the currently used standards are overviewed. Examples of the already undertaken research...

Maternal and fetal outcome in grand multipara

International Nuclear Information System (INIS)

Qamar, A.; Qamar, S.

2015-01-01

Study Design: Case control study. Place and Duration of Study: Gynecology and Obstetric Unit-I of the Jinnah Post Graduate and Medical Centre Karachi, from February 2009 to January 2010. Patients and Methods: One hundred (100) patients of grand multipara (GMP), (parity = 5) and 100 patients of multipara (MP) (parity 2-4) were included in the study. Pregnant women with known medical conditions including essential hypertension, diabetes mellitus, epilepsy, primigravidas, women with previous caesarean section and twin pregnancies were excluded. Patients were admitted through antenatal clinic and emergency. A detailed history was taken and a physical examination was done with special emphasis on obstetrical examination. Investigations like blood CP, Urine D/R, blood grouping and sonogram were done. During labour, mother and neonates were managed according to ward protocols. Maternal and fetal outcomes were compared among GMPs and MPs. Results: A high frequency of anaemia (81% vs 20%), pregnancy induced hypertension (45%, vs. 26%) and gestational diabetes (9%, vs1%) were seen in GMP as compared to MP group. Frequency of malpresentations (26% vs 15%), postpartum hemorrhage (15%, vs 10%) and intrauterine deaths (26%, vs 13%) were higher in GMP group along with a high caesarean delivery rate (GMP 21%, MP 14%). A higher maternal mortality (GMP 4%, MP 1%) and low APGAR score (GMP 12%, MP 4%) were observed among babies born to grand multipara group. Conclusion: Grand multiparity is associated with adverse outcome for both mother and fetus. Effort should be directed to reduce high parity in the community through effective family planning initiatives. Specialized antenatal and obstetrical care facilities should be available. (author)

Una visión global del e.Learning y su e.Market

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Guillermo Vázquez

Full Text Available Las Tecnologías de la Información y de la Comunicación y su aplicación en la formación y entrenamiento de los profesionales, mediante el eLearning, supone una de las grandes revoluciones que caracterizan a la Sociedad del Conocimiento. Sin embargo solo una estrategia global que encare todas sus facetas simultáneamente puede acompasar el desarrollo tecnológico y su implementación efectiva. En este artículo los autores subrayan en primer lugar la importancia del liderazgo en la fase actual de implantación y aceptación del eLearning, y los punto claves sobre los que se debe de sustentar. En segundo lugar explican las características de las acciones formativas online, y su engarce en un Campus Virtual. En tercer lugar se explican las características tecnológicas del eLearning. Finalmente recalcan la necesidad de un eMarket para asegurar que lo altos costes de una nueva metodología, son sostenibles.

Una visión global del e.Learning y su e.Market

Directory of Open Access Journals (Sweden)

Guillermo Vázquez

2006-12-01

Full Text Available Las Tecnologías de la Información y de la Comunicación y su aplicación en la formación y entrenamiento de los profesionales, mediante el eLearning, supone una de las grandes revoluciones que caracterizan a la Sociedad del Conocimiento. Sin embargo solo una estrategia global que encare todas sus facetas simultáneamente puede acompasar el desarrollo tecnológico y su implementación efectiva. En este artículo los autores subrayan en primer lugar la importancia del liderazgo en la fase actual de implantación y aceptación del eLearning, y los punto claves sobre los que se debe de sustentar. En segundo lugar explican las características de las acciones formativas online, y su engarce en un Campus Virtual. En tercer lugar se explican las características tecnológicas del eLearning. Finalmente recalcan la necesidad de un eMarket para asegurar que lo altos costes de una nueva metodología, son sostenibles.

Calculation of the top quark mass in the flipped SU(5)xU(1) superstring model

Energy Technology Data Exchange (ETDEWEB)

Leontaris, G.K.; Rizos, J.; Tamvakis, K. (Ioannina Univ. (Greece). Dept. of Physics)

1990-11-08

We present a complete renormalization group calculation of the top-quark mass in the SU(5)xU(1) superstring model. We solve the coupled renormalization group equations for the gauge and Yukawa couplings in the two-loop approximation and obtain the top-quark mass as a function of two parameters of the model which could be chosen to be ratios of singlet VEVs associated with the surplus (U(1)){sup 4} breaking. We obtain a heavy top-quark with 150 GeV{le}m{sub t}<200 GeV, for most part of the parameter space, while lower values are possible only in a very small extremal region. We also compute the allowed range of unification parameters (M{sub x}, sin{sup 2}{theta}{sub w}, {alpha}{sub 3}(M{sub W})) in the presence of a heavy top-quark. (orig.).

Towards unification of the Vorticity Confinement and Shock Capturing (TVD and ENO/WENO) methods

Science.gov (United States)

Sidilkover, David

2018-04-01

New multidimensional extensions of the TVD and finite difference ENO/WENO methods for the compressible flow equations are proposed. The novelty of the approach is in the discretization schemes that acquire by means of a single mechanism both shock-capturing and vorticity confinement capabilities. Thus, the new method can be interpreted as a unification of the two methodologies, intended initially for different purposes.

Pautas de localización de las sedes de las grandes empresas y entornos metropolitanos

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Joan-Eugeni Sánchez

2007-12-01

Full Text Available La localización de las sedes de las grandes empresas {headquarter es un tema de interés socioterritorial por cuanto implica relaciones de poder y dependencia entre territorios, con tendencia progresiva a la mundialización. El objetivo principal es detectar algunos de los factores socioterritoriales que intervienen en su localización, sobre la hipótesis de la importancia que tienen los entornos metropolitanos y de capitalidad. El análisis empírico se plantea al nivel de los centros de decisión de las grandes empresas y al nivel de los centros de decisión subsidiaria en naciones secundarias (España. Así la escala mundial de las grandes empresas multinacionales se contrastará con lo que ocurre dentro de un territorio secundario en las lógicas de distribución de las sedes primarias y subsidiarias. Se toma como base las 500 grandes empresas mundiales (Fortune, 2005 y las 1000 mayores empresas en España para los territorios secundarios. La conclusión es que la concentración territorial de poder político, poder económico y vinculación internacional -por este orden de importancia-, son los tres factores fundamentales que explican las decisiones de localización tanto de sedes centrales como subsidiarias, condiciones que de forma casi exclusiva se dan en las áreas metropolitanas, y con especial significación en las capitales de Estado

Europe '92: Consequences of the European Unification for Cultural Federalism in the Federal Republic of Germany.

Science.gov (United States)

Berggreen, Ingeborg

1990-01-01

Discusses consequences of European unification in the Federal Republic of Germany. Focuses on the relationships between the European Community, the federal government of Germany, and the German states. Suggests that the German states are aware of their responsibility to give education and culture a European dimension. (NL)

Meson-baryon four-body reaction amplitudes in exact SU(4)

International Nuclear Information System (INIS)

Liede, I.; Maalampi, J.; Roos, M.

1976-01-01

Fully SU(4) symmetric meson-baryon four body reaction amplitudes are presented in terms of SU(4) eigenamplitudes. The mesons and baryons considered belong to the SU(4) representations 15 and 20, respectively. Using these reletions, the cross-sections for the production of charmed particles can be predicted from known uncharmed reactions. (author)

Comment on “Apatite 4He/3He and (U-Th)/He Evidence for an Ancient Grand Canyon”

Science.gov (United States)

Karlstrom, Karl E.; Lee, John P.; Kelley, Shari A.; Crow, Ryan S.; Young, Richard A.; Lucchitta, Ivo; Beard, L. Sue; Dorsey, Rebecca; Ricketts, Jason; Dickinson, William R.; Crossey, Laura

2013-01-01

Flowers and Farley (Reports, 21 December 2012, p. 1616; published online 29 November 2012) propose that the Grand Canyon is 70 million years old. Starkly contrasting models for the age of the Grand Canyon—70 versus 6 million years—can be reconciled by a shallow paleocanyon that was carved in the eastern Grand Canyon 25 to 15 million years ago (Ma), negating the proposed 70 Ma and 55 Ma paleocanyons. Cooling models and geologic data are most consistent with a 5 to 6 Ma age for western Grand Canyon and Marble Canyon.

Probing grand unification with fermion masses, neutrino oscillations ...

Indian Academy of Sciences (India)

owing to the contributions from both the standard and the neutrino mass-relatedd =5 op- ..... framework emerges, which successfully accounts for a host of observed phenomena per- ...... conclusion reached by other authors (see especially ref.

Problems, puzzles and prospects: a personal perspective on present particle physics

International Nuclear Information System (INIS)

Politzer, H.D.

1982-01-01

As closing remarks to the meeting the author gives his personal perspective on a number of issues in Grand Unification. These include: gravity, particle structure, QCD and possible experimental tests of theory

Cassini's Grand Finale Science Highlights

Science.gov (United States)

Spilker, Linda

2017-10-01

After 13 years in orbit, the Cassini-Huygens Mission to Saturn ended in a science-rich blaze of glory. Cassini returned its final bits of unique science data on September 15, 2017, as it plunged into Saturn's atmosphere satisfying planetary protection requirements. Cassini's Grand Finale covered a period of roughly five months and ended with the first time exploration of the region between the rings and planet.The final close flyby of Titan in late April 2017 propelled Cassini across Saturn’s main rings and into its Grand Finale orbits; 22 orbits that repeatedly dove between Saturn’s innermost rings and upper atmosphere making Cassini the first spacecraft to explore this region. The last orbit turned the spacecraft into the first Saturn upper atmospheric probe.The Grand Finale orbits provided highest resolution observations of both the rings and Saturn, and in-situ sampling of the ring particle composition, Saturn's atmosphere, plasma, and innermost radiation belts. The gravitational field was measured to unprecedented accuracy, providing information on the interior structure of the planet, winds in the deeper atmosphere, and mass of the rings. The magnetic field provided insight into the physical nature of the magnetic dynamo and structure of the internal magnetic field. The ion and neutral mass spectrometer sampled the upper atmosphere for molecules that escape the atmosphere in addition to molecules originating from the rings. The cosmic dust analyzer directly sampled the composition from different parts of the main rings for the first time. Fields and particles instruments directly measured the plasma environment between the rings and planet.Science highlights and new mysteries gleaned to date from the Grand Finale orbits will be discussed.The research described in this paper was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Copyright 2017

Innovative SU-8 Lithography Techniques and Their Applications

Directory of Open Access Journals (Sweden)

Jeong Bong Lee

2014-12-01

Full Text Available SU-8 has been widely used in a variety of applications for creating structures in micro-scale as well as sub-micron scales for more than 15 years. One of the most common structures made of SU-8 is tall (up to millimeters high-aspect-ratio (up to 100:1 3D microstructure, which is far better than that made of any other photoresists. There has been a great deal of efforts in developing innovative unconventional lithography techniques to fully utilize the thick high aspect ratio nature of the SU-8 photoresist. Those unconventional lithography techniques include inclined ultraviolet (UV exposure, back-side UV exposure, drawing lithography, and moving-mask UV lithography. In addition, since SU-8 is a negative-tone photoresist, it has been a popular choice of material for multiple-photon interference lithography for the periodic structure in scales down to deep sub-microns such as photonic crystals. These innovative lithography techniques for SU-8 have led to a lot of unprecedented capabilities for creating unique micro- and nano-structures. This paper reviews such innovative lithography techniques developed in the past 15 years or so.

Del sueño olímpico al proyecto Porto Maravilha: el ‘eventismo’ como catalizador de la regeneración a través de grandes proyectos urbanos Do sonho olímpico ao projeto Porto Maravilha: o ‘eventismo’ como catalizador da regeneração através de grandes projetos urbanos

Directory of Open Access Journals (Sweden)

Mauro Castro Coma

2011-12-01

Full Text Available El ‘eventismo’, o la promoción de grandes eventos, se ha venido aplicando como estrategia privilegiada al alcance de las administraciones locales con el fin de desarrollar operaciones de marketing urbano, ganar proyección internacional y como medio para justificar grandes proyectos de reforma. Este parece ser el caso de Rio de Janeiro que tomando como principal referente la ciudad de Barcelona, planea servirse de las Olimpiadas como elemento catalizador para revitalizar su zona portuaria a través de un proyecto de grandes dimensiones denominado Porto Maravilha, aprobado de forma excepcional un mes después del anuncio de la ciudad como sede olímpica. Pese a que este proyecto ha sido ampliamente elogiado entre los principales agentes económicos y públicos defendiendo el legado que éste supondrá para la ciudad, consideramos necesario realizar un análisis crítico respecto a los posibles impactos de su aplicación dada la naturaleza de las estrategias a través de las cuales se está llevando a cabo. A partir del proyecto Porto Maravilha como exponente de lo que en la literatura se conoce como grandes proyectos urbanos, resaltaremos algunas de las tensiones y problemáticas asociadas a estas intervenciones de gran escala y los desafíos para la democracia urbana provocados por la adopción de modelos de gestión basados en la gobernanza urbana de carácter empresarial.

Freudental magic square and its dimensional implication for α-bar0≅137 and high energy physics

International Nuclear Information System (INIS)

El Naschie, M.S.

2008-01-01

Modern theories of high energy physics are based in one way or another on Lie symmetry group's considerations. In particular the exceptional family plays a pivotal role in superstring and E-infinity theory. For a long time the very existence of the famous 5 exceptional Lie groups G 2 , F 4 , E 6 , E 7 and E 8 with dimensions 14; 52, 78, 133 and 248 was bizarre. Freudental magic square gives some reasons to believe that the exceptional groups are not that exceptional. In the present work we elaborate this point further still and show that the sum of the dimension of E 8 , E 7 and E 6 when adding the dimensions of the two grand unification groups SO(10) and SU(4) to them amounts to the number of states in Witten's p = 5 Brane model, namely 528. Furthermore when taking the standard model SU(3) SU(2) U(1) and an eight degrees of freedom Higgs field into account, the number rises to 4 multiplied with 137 of the inverse electromagnetic fine structure constant 528+12+8=4α-bar 0 =(4)(137)=548. The general implications of these results for high energy physics are briefly discussed

La Sabana de Bogotá y su lago en el Pleniglacial Medio

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Hamenn Thomas Van Der

1986-12-01

Full Text Available Durante buena parte del Pleistoceno (últimos  2.5 millones de años, la Sabana de Bogotá fue un lago. En su extensa historia presenta cambios frecuentes de nivel, especialmente durante las épocas interglaciales en las cuales el lago se contraía y dejaba una amplia zona pantanosa y boscosa entre su orilla y el pie de los cerros (VAN DER HAMMEN & GONZÁLEZ 1960-1963; HOOGHIEMSTRA,1984. Durante el último interglacial y en los interestadiales y estadiales de la parte temprana del último glacial existía un lago relativamente grande; en los bordes y especialmente en la parte baja de los valles que desembocan a la Sabana (como el de Tenjo se encontraba vegetación pantanosa, especialmente con Alnus acuminata (Aliso acompañado en ocasiones de Weinmannia sp. y Vallea stipularis.

Interpreting mathematics in physics: Charting the applications of SU(2) in 20th century physics

Energy Technology Data Exchange (ETDEWEB)

Anderson, Ronald [Department of Philosophy, Boston College, Chestnut Hill, MA 02467 (United States)], E-mail: ronald.anderson@bc.edu; Joshi, G.C. [School of Physics, University of Melbourne, Victoria 3010 (Australia)], E-mail: joshi@physics.unimelb.edu.au

2008-04-15

The role mathematics plays within physics has been of sustained interest for physicists as well as for philosophers and historians of science. We explore this topic by tracing the role the mathematical structure associated with SU(2) has played in three key episodes in 20th century physics - intrinsic spin, isospin, and gauge theory and electroweak unification. We also briefly consider its role in loop quantum gravity. Each episode has led to profound and new physical notions of a space other than the traditional ones of space and spacetime, and each has had associated with it a complex and in places, contested history. The episodes also reveal ways mathematical structures provide resources for new physical theorizing and we propose our study as a contribution to a need Roger Penrose has identified to develop a 'profoundly sensitive aesthetic' sense for locating physically relevant mathematics.

UTC(SU) and EOP(SU) - the only legal reference frames of Russian Federation

Science.gov (United States)

Koshelyaevsky, Nikolay B.; Blinov, Igor Yu; Pasynok, Sergey L.

2015-08-01

There are two legal time reference frames in Russian Federation. UTC(SU) deals with atomic time and play a role of reference for legal timing through the whole country. The other one, EOP(SU), deals with Earth's orientation parameters and provides the official EOP data for scientific, technical and metrological applications in Russia.The atomic time is based on two essential hardware components: primary Cs fountain standards and ensemble of continuously operating H-masers as a time unit/time scale keeper. Basing on H-maser intercomparison system data, regular H-maser frequency calibration against Cs standards and time algorithm autonomous TA(SU) time scale is maintained by the Main Metrological Center. Since 2013 time unit in TA(SU) is the second (SU) reproduced independently by VNIIFTRI Cs primary standards in accordance to it’s definition in the SI. UTC(SU) is relied on TA(SU) and steering to UTC basing on TWSTFT/GNSS time link data. As a result TA(SU) stability level relative to TT considerably exceeds 1×10-15 for sample time one month and more, RMS[UTC-UTC(SU)] ≤ 3 ns for the period of 2013-2015. UTC(SU) is broadcasted by different national means such as specialized radio and TV stations, NTP servers and GLONASS. Signals of Russian radio stations contains DUT1 and dUT1 values at 0.1s and 0.02s resolution respectively.The definitive EOP(SU) are calculated by the Main Metrological Center basing on composition of the eight independent individual EOP data streams delivered by four Russian analysis centers: VNIIFTRI, Institute of Applied Astronomy, Information-Analytical Center of Russian Space Agency and Analysis Center of Russian Space Agency. The accuracy of ultra-rapid EOP values for 2014 is estimated ≤ 0.0006" for polar motion, ≤ 70 microseconds for UT1-UTC and ≤ 0.0003" for celestial pole offsets respectively.The other VNIIFTRI EOP activities can be grouped in three basic directions:- arrangement and carrying out GNSS and SLR observations at five

New fat Higgs: Increasing the MSSM Higgs mass with natural gauge unification

International Nuclear Information System (INIS)

Chang, Spencer; Kilic, Can; Mahbubani, Rakhi

2005-01-01

In this paper we increase the minimal supersymmetric standard model tree level Higgs mass bound to a value that is naturally larger than the LEP-II search constraint by adding to the superpotential a λSH u H d term, as in the next to minimal supersymmetric standard model, and UV completing with new strong dynamics before λ becomes nonperturbative. Unlike other models of this type, the Higgs fields remain elementary, alleviating the supersymmetric fine-tuning problem while maintaining unification in a natural way

Faut-il avoir peur de l’Allemagne? Représentations belges de la réunification allemande à travers 'Le Soir' et 'De Standaard'

Directory of Open Access Journals (Sweden)

Geneviève Duchenne

2012-11-01

Full Text Available Cet article revisite deux grands titres de la presse quotidienne belge, à savoir De Standaard et Le Soir, pour découvrir les perceptions qui entourèrent les événements qui se sont succédés entre l’été 1989 et l’automne 1990. Comment les différentes composantes de la société belge ont-elles réagi aux perspectives ouvertes par la chute du mur de Berlin ? Existait-il un décalage entre des élites convaincues depuis longtemps de la nécessité vitale de faire l’Europe et une population mue par un sentiment européen fort peu passionné ? Existait-il des différences de perception entre le Nord et le Sud du pays ? La réunification allemande fut-elle l’enjeu d’un débat passionné ? Le cas échéant, comment ce débat fut-il instrumentalisé ? C’est à ces quelques questions que l’article entend répondre tout en oubliant pas qu’il faudra approfondir la recherche et l’élargir notamment à d’autres sources.

Fundamental Elements and Interactions of Nature: A Classical Unification Theory

Directory of Open Access Journals (Sweden)

Tianxi Zhang

2010-04-01

Full Text Available A classical unification theory that completely unifies all the fundamental interactions of nature is developed. First, the nature is suggested to be composed of the following four fundamental elements: mass, radiation, electric charge, and color charge. All known types of matter or particles are a combination of one or more of the four fundamental elements. Photons are radiation; neutrons have only mass; protons have both mass and electric charge; and quarks contain mass, electric charge, and color charge. The nature fundamental interactions are interactions among these nature fundamental elements. Mass and radiation are two forms of real energy. Electric and color charges are considered as two forms of imaginary energy. All the fundamental interactions of nature are therefore unified as a single interaction between complex energies. The interaction between real energies is the gravitational force, which has three types: mass-mass, mass-radiation, and radiation-radiation interactions. Calculating the work done by the mass-radiation interaction on a photon derives the Einsteinian gravitational redshift. Calculating the work done on a photon by the radiation-radiation interaction derives a radiation redshift, which is much smaller than the gravitational redshift. The interaction between imaginary energies is the electromagnetic (between electric charges, weak (between electric and color charges, and strong (between color charges interactions. In addition, we have four imaginary forces between real and imaginary energies, which are mass-electric charge, radiation-electric charge, mass-color charge, and radiation-color charge interactions. Among the four fundamental elements, there are ten (six real and four imaginary fundamental interactions. This classical unification theory deepens our understanding of the nature fundamental elements and interactions, develops a new concept of imaginary energy for electric and color charges, and provides a

Fundamental Elements and Interactions of Nature: A Classical Unification Theory

Directory of Open Access Journals (Sweden)

Zhang T. X.

2010-04-01

Full Text Available A classical unification theory that completely unifies all the fundamental interactions of nature is developed. First, the nature is suggested to be composed of the following four fundamental elements: mass, radiation, electric charge, and color charge. All known types of matter or particles are a combination of one or more of the four fundamental elements. Photons are radiation; neutrons have only mass; protons have both mass and electric charge; and quarks contain mass, electric charge, and color charge. The nature fundamental interactions are interactions among these nature fundamental elements. Mass and radiation are two forms of real energy. Electric and color charges are con- sidered as two forms of imaginary energy. All the fundamental interactions of nature are therefore unified as a single interaction between complex energies. The interac- tion between real energies is the gravitational force, which has three types: mass-mass, mass-radiation, and radiation-radiation interactions. Calculating the work done by the mass-radiation interaction on a photon derives the Einsteinian gravitational redshift. Calculating the work done on a photon by the radiation-radiation interaction derives a radiation redshift, which is much smaller than the gravitational redshift. The interaction between imaginary energies is the electromagnetic (between electric charges, weak (between electric and color charges, and strong (between color charges interactions. In addition, we have four imaginary forces between real and imaginary energies, which are mass-electric charge, radiation-electric charge, mass-color charge, and radiation- color charge interactions. Among the four fundamental elements, there are ten (six real and four imaginary fundamental interactions. This classical unification theory deep- ens our understanding of the nature fundamental elements and interactions, develops a new concept of imaginary energy for electric and color charges, and provides a

Search for Z′, vacuum (instability and hints of high-energy structures

Directory of Open Access Journals (Sweden)

Accomando Elena

2016-01-01

Full Text Available We study the high-energy behaviour of a class of anomaly-free abelian extensions of the Standard Model. We focus on the interplay among the phenomenological characterisation of the model and the use of precise renormalisation group methods. Using as boundary conditions regions of the parameter space at the verge of current LHC probe, interesting unification patterns emerge linked to thresholds belonging to a SO(10 grand unification theory (GUT. We stress how the evolution of the mixing between the two abelian factors may provide a valuable tool to address the candidate high-energy embedding. The emerging unification scenarios are then challenged to be perturbative and to allow for a stable vacuum.

A K-theory anomaly free supersymmetric flipped SU(5) model from intersecting branes

Energy Technology Data Exchange (ETDEWEB)

Chen, C.-M. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States)]. E-mail: cchen@physics.tamu.edu; Kraniotis, G.V. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States)]. E-mail: kraniotis@physics.tamu.edu; Mayes, V.E. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States)]. E-mail: eric@physics.tamu.edu; Nanopoulos, D.V. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States) and Astroparticle Physics Group, Houston Advanced Research Center (HARC), Mitchell Campus, Woodlands, TX 77381 (United States) and Academy of Athens, Division of Natural Sciences, 28 Panepistimiou Avenue, Athens 10679 (Greece)]. E-mail: dimitri@physics.tamu.edu; Walker, J.W. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States)]. E-mail: jwalker@physics.tamu.edu

2005-10-06

We construct an N=1 supersymmetric three-family flipped SU(5) model from type IIA orientifolds on T{sup 6}/(Z{sub 2}xZ{sub 2}) with D6-branes intersecting at general angles. The model is constrained by the requirement that Ramond-Ramond tadpoles cancel, the supersymmetry conditions, and that the gauge boson coupled to the U(1){sub X} factor does not get a string-scale mass via a generalised Green-Schwarz mechanism. The model is further constrained by requiring cancellation of K-theory charges. The spectrum contains a complete grand unified and electroweak Higgs sector, however the latter in a non-minimal number of copies. In addition, it contains extra matter both in bi-fundamental and vector-like representations as well as two copies of matter in the symmetric representation of SU(5)

Some topics in grand unified models and the cosmological baryon asymmetry

International Nuclear Information System (INIS)

Reiss, D.B.

1981-01-01

In part I of this thesis some of the parameters relevant to the production of a cosmological baryon number asymmetry are considered in the context of grand unified models. General expressions for the average baryon number generated in the free decays of bosons are derived. The CP violation necessary for the generation of a baryon excess is discussed for a variety of SU(5) models. The kinematics of baryon number production in an illustrative SO(10) model is discussed in detail. In part II a viable SO(10) model is constructed which reproduces the phenomenological fermion mass and mixing angle values. A detailed discussion of the beta function for this model is presented. This analysis includes the effects of scalars

Fabrication of raised and inverted SU8 polymer waveguides

Science.gov (United States)

Holland, Anthony S.; Mitchell, Arnan; Balkunje, Vishal S.; Austin, Mike W.; Raghunathan, Mukund K.

2005-01-01

Polymer films with high optical transmission have been investigated for making optical devices for several years. SU8 photoresist and optical adhesives have been investigated for use as thin films for optical devices, not what they were originally designed for. Optical adhesives are typically a one component thermoset polymer and are convenient to use for making thin film optical devices such as waveguides. They are prepared in minutes as thin films unlike SU8, which has to be carefully thermally cured over several hours for optimum results. However SU8 can be accurately patterned to form the geometry of structures required for single mode optical waveguides. SU8 in combination with the lower refractive index optical adhesive films such as UV15 from Master Bond are used to form single and multi mode waveguides. SU8 is photopatternable but we have also used dry etching of the SU8 layer or the other polymer layers e.g. UV15 to form the ribs, ridges or trenches required to guide single modes of light. Optical waveguides were also fabricated using only optical adhesives of different refractive indices. The resolution obtainable is poorer than with SU8 and hence multi mode waveguides are obtained. Loss measurements have been obtained for waveguides of different geometries and material combinations. The process for making polymer waveguides is demonstrated for making large multi mode waveguides and microfluidic channels by scaling the process up in size.

Redes sociales en el sector turístico : éxito en su implantación e influencia en el comportamiento de los consumidores

OpenAIRE

Pérez Calañas, Cinta

2017-01-01

El desarrollo de las nuevas tecnologías de la información y la comunicación (TIC) que ha tenido lugar en las últimas décadas, ha ejercido un cambio muy importante en nuestra sociedad, contribuyendo a su creciente evolución económica, así como a la transformación del entorno competitivo al surgir nuevas maneras de comunicar, compartir información y realizar transacciones, Esto ha dado lugar a grandes transformaciones en las empresas que abarcan desde su sistema productivo hasta la comercializa...

Yukawa sector of minimal SO(10) unification

Energy Technology Data Exchange (ETDEWEB)

Babu, K.S. [Department of Physics, Oklahoma State University,Stillwater, OK, 74078 (United States); Bajc, Borut [Jožef Stefan Institute,Ljubljana, 1000 (Slovenia); Saad, Shaikh [Department of Physics, Oklahoma State University,Stillwater, OK, 74078 (United States)

2017-02-28

We show that in SO(10) models, a Yukawa sector consisting of a real 10{sub H}, a real 120{sub H} and a complex 126{sub H} of Higgs fields can provide a realistic fit to all fermion masses and mixings, including the neutrino sector. Although the group theory of SO(10) demands that the 10{sub H} and 120{sub H} be real, most constructions complexify these fields and impose symmetries exterior to SO(10) to achieve predictivity. The proposed new framework with real10{sub H} and real120{sub H} relies only on SO(10) gauge symmetry, and yet has a limited number of Yukawa parameters. Our analysis shows that while there are restrictions on the observables, a good fit to the entire fermion spectrum can be realized. Unification of gauge couplings is achieved with an intermediate scale Pati-Salam gauge symmetry. Proton decay branching ratios are calculable, with the leading decay modes being p→ν̄π{sup +} and p→e{sup +}π{sup 0}.

Supersymmetry and the unification of fundamental interactions.

Science.gov (United States)

Fayet, P.

Les physiciens élaborent progressivement une description unifée des lois de l'Univers, qui fait intervenir des principes de symétrie de plus en plus étendus. La supersymétrie, qui englobe la mécanique quantique et la relativité générale en opérant dans une extension de l'espace-temps ordinaire, appelée le superespace, est-elle l'un de ces principes fondamentaux? Dans cet article, l'auteur explique ce qu'est cette nouvelle symétrie, et comment, pour appliquer celle-ci au monde physique, il a été amené à envisager l'existence de toute une famille de nouvelles particules - comme les photinos, gluinos, squarks et sélectrons - que l'on recherche activement aujourd'hui. On espère parvenir à les détecter grâce aux nouvelles générations d'accélerateurs, et découvrir ainsi un nouveau principe auquel doivent satisfaire toutes les lois physiques, aussi fondamental que la relativité.

Óscar Bermúdez: investigador del Norte Grande, historiador del salitre, hombre de dos mundos.

Directory of Open Access Journals (Sweden)

Sergio González Miranda

2013-01-01

Full Text Available Este artículo tiene por objetivo hacer una semblanza biográfica del historiador Óscar Bermúdez, investigador del Norte Grande de Chile, especialmente del periodo salitrero. Para alcanzar ese objetivo, se interpretaron sus principales obras, se realizaron entrevistas y se analizaron dos estudios biográficos anteriores sobre Bermúdez. Sin embargo, este artículo no pretende ser solamente una semblanza biográfica de un personaje, sino establecer cuáles serían las principales influencias disciplinarias y de pensamientos en el trabajo historiográfico de este investigador. Se analiza de modo preferente la perspectiva epistemológica de Bermúdez, donde se discutela metodología positivista de su investigación historiográfica, que es comparada con su narrativa, especialmente sus cuentos publicados, donde se abren otras posibilidades para comprender el pensamiento de este autor.

Ten years after the unification : East Germany and the relevance of modern theories of trade, location and growth

NARCIS (Netherlands)

Brakman, S.; Schramm, M.; Garretsen, Harry

2000-01-01

In the paper we analyse, ten years after the German unification, the relevance of modern theoretical developments on trade, location and growth for East Germany using sectoral and regional data. Given our discussion of stylized facts about industry growth, economies of scale and differences in

Bankruptcy and Voluntary Liquidation: Evidence for New Firms in East and West Germany after Unification

OpenAIRE

Prantl, Susanne

2003-01-01

Exploiting the unique economic situation after German unification, I investigate how exit decisions deviate between new firms in a transition and a comparatively stable market environment. Two competing exit mechanisms are considered: entrepreneurial self-selection via voluntary liquidation and external selection based on insolvency regulation. Distinguishing between the competing exit modes proves to be crucial in semi-parametric propor- tional hazard-rate estimations. Comparing East and Wes...

Beyond the Standard Model (2/5)

CERN Multimedia

CERN. Geneva

2000-01-01

After a critical discussion of the questions left unanswered by the Standard Model, I will review the main attemps to construct new theories. In particular, I will discuss grand unification, supersymmetry, technicolour, and theories with extra dimensions.

Beyond the Standard Model (5/5)

CERN Multimedia

CERN. Geneva

2000-01-01

After a critical discussion of the questions left unanswered by the Standard Model, I will review the main attemps to construct new theories. In particular, I will discuss grand unification, supersymmetry, technicolour, and theories with extra dimensions.

Beyond the Standard Model (3/5)

CERN Multimedia

CERN. Geneva

2000-01-01

After a critical discussion of the questions left unanswered by the Standard Model, I will review the main attemps to construct new theories. In particular, I will discuss grand unification, supersymmetry, technicolour, and theories with extra dimensions.

Beyond the Standard Model (4/5)

CERN Multimedia

CERN. Geneva

2000-01-01

After a critical discussion of the questions left unanswered by the Standard Model, I will review the main attemps to construct new theories. In particular, I will discuss grand unification, supersymmetry, technicolour, and theories with extra dimensions.

CARACTERIZACIÓN DE LA FUNCIÓN DE VALOR EMPLEADA EN LAS DECISIONES AMBIENTALES POR LAS GRANDES ORGANIZACIONES: ESTUDIO DE LOS GRANDES PROYECTOS HIDROELÉCTRICOS EN COLOMBIA

Directory of Open Access Journals (Sweden)

RODOLFO GARCÍA SIERRA

2018-01-01

Full Text Available Esta investigación ofrece una explicación sobre una de las fuentes generadoras de los altos nive- les de conflictividad, actualmente predecibles entre las comunidades locales y la construcción de megaproyectos hidroeléctricos en Colombia, a través de una mirada endógena de las grandes organizaciones, específicamente en su proceso de toma de decisiones ambientales basado en juicio de expertos. En este caso el análisis se aplica a la construcción de megaproyectos hidroeléctricos (>350 MW en Colombia durante el período 2010 al 2020. La investigación emplea la teoría prospectiva acumulativa (Cumulative Prospect Theory - CPT. Se inicia determinando el uso de la heurística de disponibilidad y su cuantificación, a partir de los criterios de facilidad de recordación y tiempo de deliberación de las respuestas. Paso siguiente, se caracteriza la función de preferen - cias de los expertos, determinando las dimensiones en las que se presentan zonas de aptitudes de ganancia (altas y bajas y zonas de aptitudes de pérdidas (bajas y altas. Su aplicación a las organiza - ciones según las simulaciones realizadas, permite mejorar la influencia de las comunidades locales en las decisiones ambientales, teniendo presente los resultados sobre las aptitudes de pérdidas que han experimentado los tomadores de decisiones, ante peticiones externas en las dimensiones tecnológicas y ambientales.

Calculation of the decay rate of the proton

International Nuclear Information System (INIS)

Ross, D.A.

1980-01-01

The SU(5) model of Georgi and Glashow is used for these calculations, being the simplist such model and since the point of unification of the strong, weak and electromagnetic interactions is very intensitive to the exact details of the model provided it obeys the desert hypothesis. The broad features of the calculation are common to all models with a dessert between the W-mass and unification

N=2 extended supersymmetric GUTs

International Nuclear Information System (INIS)

Fayet, P.

1984-01-01

We construct N = 2 extended SUSY GUTs which provide a general association between massive spin-1 gauge bosons, spin-1/2 inos and spin-0 Higgs bosons. The corresponding gauge hypermultiplets are of four different types, while leptons and quarks are associated with mirror and spin-0 partners. The anticommutators of the two supersymmetry generators provide two spin-0 symmetry generators Zsub(s) and Zsub(p), which do not commute. Their field-independent parts and do commute, however, and appear as central charges in the symmetry algebra of the spontaneously broken gauge theory. These central charges and are linear combinations of global symmetry generators with grand unification generators such as the weak hypercharge (but not the electrical charge). They survive the electroweak symmetry breaking. They do not vanish for massive gauge hypermultiplets of types II and III, which verify M 2 = 2 + 2 > 0 and M 2 > 2 + 2 > 0, respectively. The formula M 2 approx.= 2 + 2 determines the mass spectrum on the grand unification scale, up to electroweak corrections. Finally, we indicate how our mass relations can be interpreted in a 5- or 6-dimensional formalism, the central charges appearing as the extra components of the covariant momentum along the compact fifth or sixth dimensions; and how to evaluate the grand unification mass msub(x) in terms of the lengths of the latter (msub(x)approx.=(h/2π)/Lsub(5(6))c). (orig./HSI)

Superstrings and the search for the theory of everything

International Nuclear Information System (INIS)

Peat, D.

1988-01-01

This book contains the following chapters: A Crisis in Physics; From Points to Strings; Nambu's String Theory; Grand Unification; Superstrings; Heterotic Strings: Two Dimensions in One; From Spinors to Twistors; Twistor Space; Twistor Gravity; and Into Deep Waters

Marketing social: inciativas de responsabilidad social corporativa y su impacto en los individuos

OpenAIRE

Viscarri Colomer, Jesús

2010-01-01

El 99,79% de los negocios en Europa están liderados por pequeñas o medianas empresas, suponiendo el 69,73% de los puestos de trabajo (Comisión Europea, 2003). El tamaño de la empresa influye en la adopción de iniciativas de responsabilidad social corporativa (RSC). Sin embargo, la literatura es generosa con las grandes corporaciones en este ámbito, siendo muy limitada para pequeñas y medianas empresas. Las primeras, debido a su mayor impacto social, se ven a menudo obligadas a incluir polí...

Geographic distribution of genetic diversity in populations of Rio Grande Chub Gila pandora

Science.gov (United States)

Galindo, Rene; Wilson, Wade; Caldwell, Colleen A.

2016-01-01

In the southwestern United States (US), the Rio Grande chub (Gila pandora) is state-listed as a fish species of greatest conservation need and federally listed as sensitive due to habitat alterations and competition with non-native fishes. Characterizing genetic diversity, genetic population structure, and effective number of breeders will assist with conservation efforts by providing a baseline of genetic metrics. Genetic relatedness within and among G. pandora populations throughout New Mexico was characterized using 11 microsatellite loci among 15 populations in three drainage basins (Rio Grande, Pecos, Canadian). Observed heterozygosity (HO) ranged from 0.71–0.87 and was similar to expected heterozygosity (0.75–0.87). Rio Ojo Caliente (Rio Grande) had the highest allelic richness (AR = 15.09), while Upper Rio Bonito (Pecos) had the lowest allelic richness (AR = 6.75). Genetic differentiation existed among all populations with the lowest genetic variation occurring within the Pecos drainage. STRUCTURE analysis revealed seven genetic clusters. Populations of G. pandora within the upper Rio Grande drainage (Rio Ojo Caliente, Rio Vallecitos, Rio Pueblo de Taos) had high levels of admixture with Q-values ranging from 0.30–0.50. In contrast, populations within the Pecos drainage (Pecos River and Upper Rio Bonito) had low levels of admixture (Q = 0.94 and 0.87, respectively). Estimates of effective number of breeders (N b ) varied from 6.1 (Pecos: Upper Rio Bonito) to 109.7 (Rio Grande: Rio Peñasco) indicating that populations in the Pecos drainage are at risk of extirpation. In the event that management actions are deemed necessary to preserve or increase genetic diversity of G. pandora, consideration must be given as to which populations are selected for translocation.

Non-accelerator particle physics

International Nuclear Information System (INIS)

Steinberg, R.I.; Lane, C.E.

1991-08-01

The goals of this research were the experimental testing of fundamental theories of physics such as grand unification and the exploration of cosmic phenomena through the techniques of particle physics. We have worked on the MACRO experiment, which is employing a large area underground detector to search for grand unification magnetic monopoles and dark matter candidates and to study cosmic ray muons as well as low and high energy neutrinos; the νIMB project, which seeks to refurbish and upgrade the IMB water Cerenkov detector to perform an improved proton decay search together with a long baseline reactor neutrino oscillation experiments using a one kiloton liquid scintillator (the Perry experiment); and development of technology for improved liquid scintillators and for very low background materials in support of the MACRO and Perry experiments and for new solar neutrino experiments

Non-accelerator particle physics

International Nuclear Information System (INIS)

Steinberg, R.I.; Lane, C.E.

1991-09-01

The goals of this research are the experimental testing of fundamental theories of physics such as grand unification and the exploration of cosmic phenomena through the techniques of particle physics. We are working on the MACRO experiment, which employs a large area underground detector to search for grand unification magnetic monopoles and dark matter candidates and to study cosmic ray muons as well as low and high energy neutrinos: the νIMB project, which seeks to refurbish and upgrade the IMB water Cerenkov detector to perform an improved proton decay search together with a long baseline reactor neutrino oscillation experiment using a kiloton liquid scintillator (the Perry experiment); and development of technology for improved liquid scintillators and for very low background materials in support of the MACRO and Perry experiments and for new solar neutrino experiments. 21 refs., 19 figs., 6 tabs

Theory of elementary particles. Proceedings

International Nuclear Information System (INIS)

Luest, D.; Weigt, G.

1994-03-01

These proceedings contain most of the invited talks ans short communications presented at the named symposium. These concern developments in field theory in connection with string models, grand unification, and quantum gravity. See hints under the relevant topics. (HSI)

Solar Cycle Variability and Grand Minima Induced by Joy's Law Scatter

Science.gov (United States)

Karak, Bidya Binay; Miesch, Mark S.

2017-08-01

The strength of the solar cycle varies from one cycle to another in an irregular manner and the extreme example of this irregularity is the Maunder minimum when Sun produced only a few spots for several years. We explore the cause of these variabilities using a 3D Babcock--Leighton dynamo. In this model, based on the toroidal flux at the base of the convection zone, bipolar magnetic regions (BMRs) are produced with flux, tilt angle, and time of emergence all obtain from their observed distributions. The dynamo growth is limited by a tilt quenching.The randomnesses in the BMR emergences make the poloidal field unequal and eventually cause an unequal solar cycle. When observed fluctuations of BMR tilts around Joy's law, i.e., a standard deviation of 15 degrees, are considered, our model produces a variation in the solar cycle comparable to the observed solar cycle variability. Tilt scatter also causes occasional Maunder-like grand minima, although the observed scatter does not reproduce correct statistics of grand minima. However, when we double the tilt scatter, we find grand minima consistent with observations. Importantly, our dynamo model can operate even during grand minima with only a few BMRs, without requiring any additional alpha effect.

New dimensions new hopes

International Nuclear Information System (INIS)

Sarkar, Utpal

2001-05-01

We live in a four dimensional world. But the idea of unification of fundamental interactions lead us to higher dimensional theories. Recently a new theory with extra dimensions has emerged where only gravity propagates in the extra dimension and all other interactions are confined to only four dimensions. This theory gives us many new hopes. In earlier theories unification of strong, weak and the electromagnetic forces was possible at around 10 16 GeV in a grand unified theory (GUT) and it could get unified with gravity at around the Planck scale of 10 19 GeV. With this new idea it is possible to bring down all unification scales within the reach of the new generation accelerators, i.e., around 10 4 GeV. (author)

Effects of design geometry on SU8 polymer waveguides

Science.gov (United States)

Holland, Anthony S.; Balkunje, Vishal S.; Mitchell, Arnan; Austin, Michael W.; Raghunathan, Mukund K.; Kostovski, Gorgi

2005-02-01

The spin-on photoresist SU8 from MicroChem has a relatively high refractive index (n=1.57 at 1550nm) compared with other polymers. It is stable and has high optical transmission at optical communication wavelengths. In this paper we study rib waveguides fabricated using SU8 as the core layer and thermoset polymers UV15 (n=1.50 at 1550nm) from Master Bond and NOA61 (n=1.54 at 1550nm) from Gentec as the cladding layers. The rib height is varied from 0.3 to 1.7μm high. This is part of the SU8 layer sandwiched between the cladding layers. The waveguides are tested to determine the effects of varying this geometry for single mode optical transmission. The lengths of the waveguides were 1.5 cm to 5 cm.

Radio Loud AGN Unification: Connecting Jets and Accretion

Directory of Open Access Journals (Sweden)

Meyer Eileen T.

2013-12-01

Full Text Available While only a fraction of Active Galactic Nuclei are observed to host a powerful relativistic jet, a cohesive picture is emerging that radio-loud AGN may represent an important phase in the evolution of galaxies and the growth of the central super-massive black hole. I will review my own recent observational work in radio-loud AGN unification in the context of understanding how and why jets form and their the connection to different kinds of accretion and growing the black hole, along with a brief discussion of possible connections to recent modeling work in jet formation. Starting from the significant observational advances in our understanding of jetted AGN as a population over the last decade thanks to new, more sensitive instruments such as Fermi and Swift as well as all-sky surveys at all frequencies, I will lay out the case for a dichotomy in the jetted AGN population connected to accretion mode onto the black hole. In recent work, we have identified two sub-populations of radio-loud AGN which appear to be distinguished by jet structure, where low-efficiency accreting systems produce ‘weak’ jets which decelerate more rapidly than the ’strong’ jets of black holes accreting near the Eddington limit. The two classes are comprised of: (1The weak jet sources, corresponding to the less collimated, edge-darkened FR Is, with a decelerating or spine-sheath jet with velocity gradients, and (2 The strong jet sources, having fast, collimated jets, and typically displaying strong emission lines. The dichotomy in the vp-Lp plane can be understood as a "broken power sequence" in which jets exist on one branch or the other based on the particular accretion mode (Georganopolous 2011.We suggest that the intrinsic kinetic power (as measured by low-frequency, isotropic radio emission, the orientation, and the accretion rate of the SMBH system are the the fundamental axes needed for unification of radio-loud AGN by studying a well-characterized sample

Physics possibilities at a linear collider

Indian Academy of Sciences (India)

Up to now the standard model (SM) has passed all accelerator-based experimental tests. .... Higgs sector and of the MSSM as well as for testing grand unification. ..... SPS1a scenario [33] for a coherent combination of LHC and linear collider.

Proceedings of the 8 Warsaw symposium on elementary particle physics, Kazimierz, Poland, May 26 - June 1, 1985

International Nuclear Information System (INIS)

Ajduk, Z.

1985-01-01

These proceedings contain 47 lectures held at the symposium. They deal with pbar-p collider results, phenomenology of electroweak effects, high energy lepton interactions, high energy hadron interactions, quantum chromodynamics, bag model, grand unification, supersymmetry and superstring theory. (M.F.W.)

A natural scenario for heavy colored and light uncolored superpartners

International Nuclear Information System (INIS)

Bhattacharyya, Gautam; Bhattacherjee, Biplob; Yanagida, Tsutomu T.; Yokozaki, Norimi

2013-01-01

Influenced by the current trend of experimental data, especially from the LHC, we construct a supersymmetric scenario where a natural dynamics makes the squarks and gluino super-heavy (order 10 TeV) while keeping the sleptons and the weak gauginos light (100–500 GeV). The dynamics relies on the interfusion of two underlying ideas: (i) gauge mediation of supersymmetry breaking with two messenger multiplets, one transforming as a triplet of weak SU(2) and the other as an octet of color SU(3); (ii) perturbative gauge coupling unification at the string scale even with these incomplete SU(5) multiplets. Interestingly, the relative magnitude of the triplet and octet messenger scales that ensures gauge unification at the two-loop level also helps to naturally keep the uncolored superpartners light while making the colored ones heavy

El destilatorio de Quellón Nuevo: génesis y decadencia de un pueblo en la Isla Grande de Chiloé./ The New Quellon distillatory: genesis and decay of a town on the Big Island of Chiloe, Chile.

Directory of Open Access Journals (Sweden)

Quilodrán Rubio, Carolina

2009-12-01

Full Text Available Quellón, una de las principales ciudades chilotas, confín de la Isla Grande, debe su desarrollo económico y social a un destilatorio de alcoholes y maderas. A diferencia de la mayor parte de las demás localidades sureñas, germinalmente hispánicas y nutridas por la industria maderera de comienzos del siglo XX, la comunidad de Quellón construye su andamiaje sobre los réditos económicos que derivan del destilatorio. Su ocaso, sin embargo, deriva del cuestionable desembarco de la industria salmonícola./ Quellón, one of the main chiloteans cities, confine of Isla Grande, because their economic and social development a distiller of alcohols and Woods. Unlike most of the other cities in southern, originally Hispanic and abounding by timber of early 20th century, the community of Quellón builds your scaffolding on economic revenues derived from the distiller. Its decline, however, derives from the questionable landing salmon's industry.

What energy does gravity unite with grand unified theories in the early universe

International Nuclear Information System (INIS)

Sivaram, C.

1987-01-01

Unification of gravity with GUTs is usually expected at the Planck energy E/sub PI/ ∼ 10 19 GeV. However, the vastly different values of the two couplings at E/sub PI/ (α/sub GUT/ E/sub PI/ with a single dimensionless coupling constant (α/sub U/ << 1) and described by a scale-invariant action quadratic in the Weyl curvature (with Yang-Mills fields). Breaking of scale invariance at E/sub PI/ then separates the interactions into gravity, now described by a Hilbert action with a dimensional G and GUTs with a dimensionless α/sub GUT/ and YM action. Problems with Klein-Kaluza unification of gravity with GUTs are also discussed in this context

A test of unification towards the radio source PKS1413+135

International Nuclear Information System (INIS)

Ferreira, M.C.; Julião, M.D.; Martins, C.J.A.P.; Monteiro, A.M.R.V.L.

2013-01-01

We point out that existing astrophysical measurements of combinations of the fine-structure constant α, the proton-to-electron mass ratio μ and the proton gyromagnetic ratio g p towards the radio source PKS1413+135 can be used to individually constrain each of these fundamental couplings. While the accuracy of the available measurements is not yet sufficient to test the spatial dipole scenario, our analysis serves as a proof of concept as new observational facilities will soon allow significantly more robust tests. Moreover, these measurements can also be used to obtain constraints on certain classes of unification scenarios, and we compare the constraints obtained for PKS1413+135 with those previously obtained from local atomic clock measurements

A test of unification towards the radio source PKS1413+135

Energy Technology Data Exchange (ETDEWEB)

Ferreira, M.C., E-mail: up200802537@fc.up.pt [Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4150-007 Porto (Portugal); Julião, M.D., E-mail: meinf12013@fe.up.pt [Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Faculdade de Engenharia, Universidade do Porto, Rua Dr Roberto Frias, 4200-465 Porto (Portugal); Martins, C.J.A.P., E-mail: Carlos.Martins@astro.up.pt [Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Monteiro, A.M.R.V.L., E-mail: mmonteiro@fc.up.pt [Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4150-007 Porto (Portugal); Department of Applied Physics, Delft University of Technology, P.O. Box 5046, 2600 GA Delft (Netherlands)

2013-07-09

We point out that existing astrophysical measurements of combinations of the fine-structure constant α, the proton-to-electron mass ratio μ and the proton gyromagnetic ratio g{sub p} towards the radio source PKS1413+135 can be used to individually constrain each of these fundamental couplings. While the accuracy of the available measurements is not yet sufficient to test the spatial dipole scenario, our analysis serves as a proof of concept as new observational facilities will soon allow significantly more robust tests. Moreover, these measurements can also be used to obtain constraints on certain classes of unification scenarios, and we compare the constraints obtained for PKS1413+135 with those previously obtained from local atomic clock measurements.

Self-Similar Symmetry Model and Cosmic Microwave Background

Directory of Open Access Journals (Sweden)

Tomohide eSonoda

2016-05-01

Full Text Available In this paper, we present the self-similar symmetry (SSS model that describes the hierarchical structure of the universe. The model is based on the concept of self-similarity, which explains the symmetry of the cosmic microwave background (CMB. The approximate length and time scales of the six hierarchies of the universe---grand unification, electroweak unification, the atom, the pulsar, the solar system, and the galactic system---are derived from the SSS model. In addition, the model implies that the electron mass and gravitational constant could vary with the CMB radiation temperature.

Dynamical resonance shift and unification of resonances in short-pulse laser-cluster interaction

Science.gov (United States)

Mahalik, S. S.; Kundu, M.

2018-06-01

Pronounced maximum absorption of laser light irradiating a rare-gas or metal cluster is widely expected during the linear resonance (LR) when Mie-plasma wavelength λM of electrons equals the laser wavelength λ . On the contrary, by performing molecular dynamics (MD) simulations of an argon cluster irradiated by short 5-fs (FWHM) laser pulses it is revealed that, for a given laser pulse energy and a cluster, at each peak intensity there exists a λ —shifted from the expected λM—that corresponds to a unified dynamical LR at which evolution of the cluster happens through very efficient unification of possible resonances in various stages, including (i) the LR in the initial time of plasma creation, (ii) the LR in the Coulomb expanding phase in the later time, and (iii) anharmonic resonance in the marginally overdense regime for a relatively longer pulse duration, leading to maximum laser absorption accompanied by maximum removal of electrons from cluster and also maximum allowed average charge states for the argon cluster. Increasing the laser intensity, the absorption maxima is found to shift to a higher wavelength in the band of λ ≈(1 -1.5 ) λM than permanently staying at the expected λM. A naive rigid sphere model also corroborates the wavelength shift of the absorption peak as found in MD and unequivocally proves that maximum laser absorption in a cluster happens at a shifted λ in the marginally overdense regime of λ ≈(1 -1.5 ) λM instead of λM of LR. The present study is important for guiding an optimal condition laser-cluster interaction experiment in the short-pulse regime.

Higgs mass in the gauge-Higgs unification

International Nuclear Information System (INIS)

Haba, Naoyuki; Takenaga, Kazunori; Yamashita, Toshifumi

2005-01-01

The gauge-Higgs unification theory identifies the zero mode of the extra-dimensional component of the gauge field as the usual Higgs doublet. Since this degree of freedom is the Wilson line phase, the Higgs does not have the mass term nor quartic coupling at the tree level. Through quantum corrections, the Higgs can take a vacuum expectation value, and its mass is induced. The radiatively induced mass tends to be small, although it can be lifted to O(100) GeV by introducing the O(10) numbers of bulk fields. Perturbation theory becomes unreliable when a large number of bulk fields are introduced. We reanalyze the Higgs mass based on useful expansion formulae for the effective potential and find that even a small number of bulk field can have the suitable heavy Higgs mass. We show that a small (large) number of bulk fields are enough (needed) when the SUSY breaking mass is large (small). We also study the case of introducing the soft SUSY breaking scalar masses in addition to the Scherk-Schwarz SUSY breaking and obtain the heavy Higgs mass due to the effect of the scalar mass

¿Por qué cilindros de 15 x 30 cm para obtener la resistencia a compresión del hormigón?

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Garralón Jorba, José

1983-07-01

Full Text Available Not available.Se refiere este trabajo a la exposición de los estudios realizados por su autor, para reemplazar las probetas cilíndricas de 15 cm de diámetro y 30 cm de altura, que se emplean para el ensayo del hormigón a compresión, por probetas también cilíndricas, de 4 cm de diámetro y 4 cm de altura, obtenidas del mortero del hormigón a ensayar. Tres grandes ventajas aporta este sistema dentro de la misma fiabilidad que ofrece el procedimiento en uso actualmente: •Menos volumen. •Menos peso. •Menos costo, A las que se puede añadir más comodidad en los ensayos de control.

Unification, small and large

Energy Technology Data Exchange (ETDEWEB)

Fritzsch, Harald

1993-04-15

Full text: Fruitful exchanges between particle physics, astrophysics and cosmology have become a common feature in the last decade. In January, Coral Gables near Miami was the stage for a 'Unified Symmetry in the Small and the Large' meeting. Coral Gables is a famous physics venue. In January 1964, the year that the quark model of hadrons emerged, Behram Kursunoglu initiated a series of particle physics meetings that continued for 20 years and formed a regular focus for this development. The final such meeting was in 1983, coinciding with both the 80th birthday of field theory pioneer Paul Dirac, who worked in Florida towards the end of his career, and the discovery of the W bosons at CERN. The resurrected Coral Gables meeting began with historical accounts of the emergence of Big Bang cosmology, by Robert Ralph and Herman Alpher, while Andrei Linde proposed our expanding universe as a small part of a stationary system, infinite both in space and in time. The observational status of Big Bang cosmology was reviewed by Bruce Partridge, John Mather and Martin Harwit, emphasizing the cosmic background radiation, where temperature is now measured by the COBE satellite detectors to 2.726 ± 0.01 OK. The tiny fluctuations observed by COBE pose problems for standard cold dark matter models. Edward ('Rocky') Kolb reported on new studies on the electroweak phase transition, based on an analogy with the physics of liquid crystals. Richard Holman discussed the fate of global symmetries at energies near the Planck (grand unification) energy, and Paul Steinhardt talked about tensorial and scalar metric fluctuations in the light of the COBE results. Anthony Tyson gave an impressive description of dark matter studies using gravitational lensing, now emerging as a unique tool for indirectly observing intervening dark matter. A neutrino mass of 10 electronvolts could account for observed dark matter distributions, but fails to provide the necessary seeds for galaxy formation. A

Unification, small and large

International Nuclear Information System (INIS)

Fritzsch, Harald

1993-01-01

Full text: Fruitful exchanges between particle physics, astrophysics and cosmology have become a common feature in the last decade. In January, Coral Gables near Miami was the stage for a 'Unified Symmetry in the Small and the Large' meeting. Coral Gables is a famous physics venue. In January 1964, the year that the quark model of hadrons emerged, Behram Kursunoglu initiated a series of particle physics meetings that continued for 20 years and formed a regular focus for this development. The final such meeting was in 1983, coinciding with both the 80th birthday of field theory pioneer Paul Dirac, who worked in Florida towards the end of his career, and the discovery of the W bosons at CERN. The resurrected Coral Gables meeting began with historical accounts of the emergence of Big Bang cosmology, by Robert Ralph and Herman Alpher, while Andrei Linde proposed our expanding universe as a small part of a stationary system, infinite both in space and in time. The observational status of Big Bang cosmology was reviewed by Bruce Partridge, John Mather and Martin Harwit, emphasizing the cosmic background radiation, where temperature is now measured by the COBE satellite detectors to 2.726 ± 0.01 OK. The tiny fluctuations observed by COBE pose problems for standard cold dark matter models. Edward ('Rocky') Kolb reported on new studies on the electroweak phase transition, based on an analogy with the physics of liquid crystals. Richard Holman discussed the fate of global symmetries at energies near the Planck (grand unification) energy, and Paul Steinhardt talked about tensorial and scalar metric fluctuations in the light of the COBE results. Anthony Tyson gave an impressive description of dark matter studies using gravitational lensing, now emerging as a unique tool for indirectly observing intervening dark matter. A neutrino mass of 10 electronvolts could account for observed dark matter distributions, but fails to provide the necessary seeds for

Borehole DC-15 hydrostratigraphic chart

International Nuclear Information System (INIS)

Gephart, R.E.

1981-09-01

This hydrostratigraphic chart identifies the basic stratigraphy and preliminary hydrologic testing results for Borehole DC-15. This borehole was cored through the Saddle Mountains and Wanapum basalt formations and into the Grande Ronde. Selected zones were hydrologically tested during coring

MODELACIÓN DE TRÁNSITO DE CRECIENTES EN EL RÍO ABURRÁ-MEDELLÍN PARA UNA PROPUESTA DE SU RESTAURACIÓN

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Andrés Felipe Marín Muñoz

Full Text Available La cuenca del río Aburrá-Medellín está localizada sobre la cordillera central, en el departamento de Antioquia. El río nace en el Alto de San Miguel en el municipio de Caldas y atraviesa 10 municipios hasta finalmente unirse con el río Grande, donde cambia de nombre a río Porce. El tramo del río Aburrá-Medellín comprendido entre el nacimiento y su entrada al municipio de Caldas ha sufrido grandes alteraciones en sus condiciones naturales debido a la explotación de materiales para construcción. También se ha visto afectado por la deforestación de su cuenca y la introducción de fauna no nativa que han afectado la disponibilidad del recurso y su calidad. El proyecto tiene como objetivo formular alternativas de restauración para algunos tramos del río Medellín que presentan un alto grado de afectación antrópica. Para el análisis hidrológico e hidráulico se utilizaron los programas HEC-HMS, HEC-RAS e Iber como soporte técnico para establecer las medidas de restauración. Se espera que los resultados de este proyecto sirvan como apoyo para otros de mayor alcance como el POMCA, el proyecto Bio 2030 y los Parques del Río Medellín.

AFECCIÓN DE LAS AUTOVÍAS A SU ENTORNO RURAL: EXTREMADURA

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Antonio Pérez Díaz

2016-01-01

Full Text Available La relación entre el transporte terrestre, y más específicamente el transporte por carretera a través de vías de gran capacidad o autovías, ha sido ampliamente estudiada desde la órbita urbana, por cuanto que éstas se estructuran como red de conexión de grandes núcleos a pesar de que discurren inevitablemente por territorio rural, como es el caso de la comunidad autónoma de Extremadura. Surge el interrogante de qué pasa con los pequeños núcleos ubicados al lado de estos corredores de transporte cuyo diseño se acometió a sus espaldas. Se estudia, por ello, cómo pueden ser afectados una serie de parámetros de territorios claramente rurales según su cercanía a una autovía. Los resultados indican distintos comportamientos de entornos rurales asociados a su grado de accesibilidad a una red de autovías.

Ensino de enfermagem no Rio Grande do Sul apartir de 1950 Enseñanza de enfermería en Rio Grande do Sul a partir del 1950 Teaching of nursing in Rio Grande do Sul in the 1950

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Valéria Lamb Corbellini

2010-08-01

Full Text Available Essa pesquisa teve como objetivo analisar como o ensino de graduação na enfermagem, no Rio Grande do Sul construiu o seu saber, desde o primeiro curso, a partir da década de 1950. O estudo envolveu enfermeiras docentes que vivenciaram esse período da história e, para análise documental, foi utilizada a análise de discurso. Os dados indicam, dentre eles, o currículo mais integrado que busca articular teoria/prática sem fragmentação do saber e a relação ensino-aprendizagem, na qual professor e aluno são sujeitos desse processo.Esta investigación tuvo como objetivo analizar como la enseñanza de la pregrado de Enfermería en Río Grande do Sul construyó su saber, desde el primer curso, a partir de la década de 1950. El estudio integró enfermeras docentes que vivenciaron ese periodo de la historia y, para el análisis documental, fue utilizado el análisis del discurso.Los datos indican, entre ellos, el curriculum más integrado que busca articular teoría y práctica sin fragmentación del saber y la relación enseñanza aprendizaje, en la cuál el profesor y el alumno son sujetos de ese processo.The purpose of this research was to analyze how the undergraduate teaching of nursing in Rio Grande do Sul has constructed its knowledge, since the first course, as of the decade of 1950s. The survey has involved teaching nurses who have lived such period of our history, and the discourse analysis has been utilized for the documental analysis. The information data indicate, among them, the most integrated curriculum that seeks articulating theory/practice without fragmenting the knowledge and the teaching-learning relationship, wherein professors and students are subjects of such procedure.

Diffraction scattering and the parton model in QCD

International Nuclear Information System (INIS)

White, A.

1985-01-01

Arguments are presented that the validity of the parton model for hadron scattering in QCD is directly related to the occurrence of the Critical Pomeron description of diffraction scattering. An attractive route suggested for Electroweak and Grand Unification is also briefly described