[SU(2)]3 dark matter

Science.gov (United States)

Ma, Ernest

2018-05-01

An extra SU(2)D gauge factor is added to the well-known left-right extension of the standard model (SM) of quarks and leptons. Under SU(2)L × SU(2)R × SU(2)D, two fermion bidoublets (2 , 1 , 2) and (1 , 2 , 2) are assumed. The resulting model has an automatic dark U (1) symmetry, in the same way that the SM has automatic baryon and lepton U (1) symmetries. Phenomenological implications are discussed, as well as the possible theoretical origins of this proposal.

Symmetry breaking and asymptotic freedom in colour SU(3) gauge models

International Nuclear Information System (INIS)

Ma, E.

1976-01-01

A class of quark models based on the colour gauge group SU(3) is shown to be asymptotically free despite the complete breakdown of local symmetry to guarantee infrared stability. The symmetry breakdown is achieved by the presence of elementary scalar fields either through the Higgs mechanism or dynamically as first proposed by Coleman and Weinberg. Asymptotic freedom is preserved by imposing eigenvalue conditions on the coupling constants as first proposed by Chang. New quark species must be present, but below their production threshold, colour can still be a global symmetry which is approximate under SU(3), but exact under SU(2). Among the many implications of this class of models is the possibility of producing isolated quarks and gluons of non-zero mass without altering the short-distance behaviour of the superstrong interaction which binds them. (Auth.)

Evidence for dynamic SU(5) symmetry breaking in meson mass multiplets

International Nuclear Information System (INIS)

Frikkee, E.

1994-07-01

It is shown that the mass differences and multiplet pattern for pseudoscalar and vector mesons correspond to a chain of dynamic symmetry reductions SU(n) contains SU(n-1)xU(1). In this symmetry-reduction model, the differences between the masses of the quark flavours are the result of intra-hadronic interactions. Quark confinement is explained as a consequence of the fact that this symmetry breaking chain only occurs in hadrons. The results of a quantitative analysis of mass splittings in meson multiplets indicate that SU(5) is probably the highest symmetry for hadron states. In the proposed dynamic symmetry breaking scheme with five quark flavours there is no one-to-one correspondence between lepton and quark generations. (orig.)

Broken SU(4) symmetry and new resonance

International Nuclear Information System (INIS)

Ueda, Y.

1975-11-01

Weinberg's spectral function sum rules are modified to accommodate broken symmetry effects of SU(4). With a simple choice of the symmetry-breaking term, the spectral function sum rules yield the observed vector meson mass spectrum as well as sum rules for the e - e + decay rates of vector mesons. In particular, a new mass formula, which can be interpreted as the broken symmetry version of the Schwinger formula, is derived, the agreement with experiments is excellent. (Ueda, Y.)

Minimal Supersymmetric $SU(4) \\to SU(2)_L \\to SU(2)_R$

CERN Document Server

King, S F

1998-01-01

We present a minimal string-inspired supersymmetric $SU(4) \\times SU(2)_L potential in this model, based on a generalisation of that recently proposed by Dvali, Lazarides and Shafi. The model contains a global U(1) R-symmetry and reduces to the MSSM at low energies. However it improves on the MSSM since it explains the magnitude of its $\\mu$ term and gives a prediction for $\\tan \\beta both `cold' and `hot' dark matter candidates. A period of hybrid inflation above the symmetry breaking scale is also possible in this model. Finally it suggests the existence of `heavy' charge $\\pm e/6$ (colored) and $\\pm e/2$ (color singlet) states.

Conflict between natural flavor conservation of Higgs couplings and Cabibbo mixing in SU(2)/sub L/ x U (1)

International Nuclear Information System (INIS)

Segre, G.; Arthur Weldon, H.

1980-01-01

The general problem of conservation of strangeness and other quark flavors by the exchange of several neutral Higgs mesons is investigated in SU (2)/sub L/ x U (1). We find that the horizontal symmetries necessary to enforce this conservation conflict with the known Cabibbo mixing. In particular, if the quarks form an irreducible representation of the horizontal symmetry, the mixing angles are all trivial (i.e. 0 or π/2); if they form a reducible representation, it is possible to have some nontrivial mixing angles, but only if there are several unmixed generations of quarks with exactly the same relative pattern of masses and mixings

On the algebraic realization of SU(4) symmetry

International Nuclear Information System (INIS)

Asatryan, G.M.; Zaslavsky, A.N.

1976-01-01

A possibility of nonlinear realization of the symmetry with linearization on the SU(4)xYxC group is discussed. Algebraic properties of SU(4) are restored from the Weinberg condition: amplitudes of goldstone scattering on particles should have a reasonable (as in the Regge theory) asymptotic behaviour. In this case the breaking appears to be minimal. Large values of psi meson masses lead to high-lying charmed trajectories in the SU(4) algebraic realization

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

Inflation and monopoles in supersymmetric SU(4)c x SU(2)L x SU(2)R

International Nuclear Information System (INIS)

Jeannerot, R.; Khalil, S.; Lazarides, G.; Shafi, Q.

2000-02-01

We show how hybrid inflation can be successfully realized in a supersymmetric model with gauge group G PS = SU(4) c x SU(2) L x SU(2) R . By including a non-renormalizable superpotential term, we generate an inflationary valley along which G PS is broken to the standard model gauge group. Thus, catastrophic production of the doubly charged magnetic monopoles, which are predicted by the model, cannot occur at the end of inflation. The results of the cosmic background explorer can be reproduced with natural values (of order 10 -3 ) of the relevant coupling constant, and symmetry breaking scale of G PS close to 10 16 GeV. The spectral index of density perturbations lies between unity and 0.94. Moreover, the μ-term is generated via a Peccei-Quinn symmetry and proton is practically stable. Baryogenesis in the universe takes place via leptogenesis. The low deuterium abundance constraint on the baryon asymmetry, the gravitino limit on the reheat temperature and the requirement of almost maximal ν μ - ν τ mixing from SuperKamiokande can be simultaneously met with m νμ , m ντ and heaviest Dirac neutrino mass determined from the large angle MSW resolution of the solar neutrino problem, the SuperKamiokande results and SU(4) c symmetry respectively. (author)

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.

Working memory and individual differences in the encoding of vertical, horizontal and diagonal symmetry.

Science.gov (United States)

Rossi-Arnaud, Clelia; Pieroni, Laura; Spataro, Pietro; Baddeley, Alan

2012-09-01

Previous studies, using a modified version of the sequential Corsi block task to examine the impact of symmetry on visuospatial memory, showed an advantage of vertical symmetry over non-symmetrical sequences, but no effect of horizontal or diagonal symmetry. The present four experiments investigated the mechanisms underlying the encoding of vertical, horizontal and diagonal configurations using simultaneous presentation and a dual-task paradigm. Results indicated that the recall of vertically symmetric arrays was always better than that of all other patterns and was not influenced by any of the concurrent tasks. Performance with horizontally or diagonally symmetrical patterns differed, with high performing participants showing little effect of concurrent tasks, while low performers were disrupted by concurrent visuospatial and executive tasks. A verbal interference had no effect on either group. Implications for processes involved in the encoding of symmetry are discussed, together with the crucial importance of individual differences. Copyright © 2012 Elsevier B.V. All rights reserved.

SU(3) chiral symmetry for baryons

International Nuclear Information System (INIS)

Dmitrasinovic, V.

2011-01-01

Three-quark nucleon interpolating fields in QCD have well-defined SU L (3)xSU R (3) and U A (1) chiral transformation properties, viz. [(6,3)+(3,6)], [(3,3-bar)+(3-bar,3)], [(8,1)+(1,8)] and their 'mirror' images. It has been shown (phenomenologically) in Ref. [2] that mixing of the [(6,3)+(3,6)] chiral multiplet with one ordinary ('naive') and one 'mirror' field belonging to the [(3,3-bar)+(3-bar,3)], [(8,1)+(1,8)] multiplets can be used to fit the values of the isovector (g A (3) ) and the flavor-singlet (isoscalar) axial coupling (g A (0) ) of the nucleon and then predict the axial F and D coefficients, or vice versa, in reasonable agreement with experiment. In an attempt to derive such mixing from an effective Lagrangian, we construct all SU L (3)xSU R (3) chirally invariant non-derivative one-meson-baryon interactions and then calculate the mixing angles in terms of baryons' masses. It turns out that there are (strong) selection rules: for example, there is only one non-derivative chirally symmetric interaction between J 1/2 fields belonging to the [(6,3)+(3,6)] and the [(3,3-bar)+(3-bar,3)] chiral multiplets, that is also U A (1) symmetric. We also study the chiral interactions of the [(3,3-bar)+(3-bar,3)] and [(8,1)+(1,8)] nucleon fields. Again, there are selection rules that allow only one off-diagonal non-derivative chiral SU L (3)xSU R (3) interaction of this type, that also explicitly breaks the U A (1) symmetry. We use this interaction to calculate the corresponding mixing angles in terms of baryon masses and fit two lowest lying observed nucleon (resonance) masses, thus predicting the third (J = 1/2, I = 3/2)Δ resonance, as well as one or two flavor-singlet Λ hyperon(s), depending on the type of mixing. The effective chiral Lagrangians derived here may be applied to high density matter calculations.

SU(1,2) invariance in two-dimensional oscillator

Energy Technology Data Exchange (ETDEWEB)

Krivonos, Sergey [Bogoliubov Laboratory of Theoretical Physics,Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Nersessian, Armen [Yerevan State University,1 Alex Manoogian St., Yerevan, 0025 (Armenia); Tomsk Polytechnic University,Lenin Ave. 30, 634050 Tomsk (Russian Federation)

2017-02-01

Performing the Hamiltonian analysis we explicitly established the canonical equivalence of the deformed oscillator, constructed in arXiv:1607.03756, with the ordinary one. As an immediate consequence, we proved that the SU(1,2) symmetry is the dynamical symmetry of the ordinary two-dimensional oscillator. The characteristic feature of this SU(1,2) symmetry is a non-polynomial structure of its generators written in terms of the oscillator variables.

The vertical, the horizontal and the rest: anatomy of the middle cohomology of Calabi-Yau fourfolds and F-theory applications

Energy Technology Data Exchange (ETDEWEB)

Braun, A.P. [Department of Mathematics, King’s College,London WC2R 2LS (United Kingdom); Watari, T. [Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo,Kashiwano-ha 5-1-5, 277-8583 (Japan)

2015-01-12

The four-form field strength in F-theory compactifications on Calabi-Yau fourfolds takes its value in the middle cohomology group H{sup 4}. The middle cohomology is decomposed into a vertical, a horizontal and a remaining component, all three of which are present in general. We argue that a flux along the remaining or vertical component may break some symmetry, while a purely horizontal flux does not influence the unbroken part of the gauge group or the net chirality of charged matter fields. This makes the decomposition crucial to the counting of flux vacua in the context of F-theory GUTs. We use mirror symmetry to derive a combinatorial formula for the dimensions of these components applicable to any toric Calabi-Yau hypersurface, and also make a partial attempt at providing a geometric characterization of the four-cycles Poincaré dual to the remaining component of H{sup 4}. It is also found in general elliptic Calabi-Yau fourfolds supporting SU(5) gauge symmetry that a remaining component can be present, for example, in a form crucial to the symmetry breaking SU(5)⟶SU(3){sub C}×SU(2){sub L}×U(1){sub Y}. The dimension of the horizontal component is used to derive an estimate of the statistical distribution of the number of generations and the rank of 7-brane gauge groups in the landscape of F-theory flux vacua.

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

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...

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

International Nuclear Information System (INIS)

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 multiparameter 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 alternative symmetry breaking mechanisms in models with this gauge group. Specifically, we study the recently proposed 'clash of symmetries' brane-world mechanism to see if it can help with the symmetry breaking conundrum. This requires a detailed analysis of Higgs potential global minima and kink or domain wall solutions interpolating between the disconnected global minima created through spontaneous discrete symmetry breaking. Sufficiently long-lived metastable kinks can also be considered. We develop what we think is an interesting, albeit speculative, brane-world scheme whereby the hierarchical symmetry breaking cascade, trinification to left-right symmetry to the standard model to color cross electromagnetism, may be induced without an initial hierarchy in vacuum expectation values. Another motivation for this paper is simply to continue the exploration of the rich class of kinks arising in models that are invariant under both discrete and continuous symmetries

The effect of vertical and horizontal symmetry on memory for tactile patterns in late blind individuals.

Science.gov (United States)

Cattaneo, Zaira; Vecchi, Tomaso; Fantino, Micaela; Herbert, Andrew M; Merabet, Lotfi B

2013-02-01

Visual stimuli that exhibit vertical symmetry are easier to remember than stimuli symmetric along other axes, an advantage that extends to the haptic modality as well. Critically, the vertical symmetry memory advantage has not been found in early blind individuals, despite their overall superior memory, as compared with sighted individuals, and the presence of an overall advantage for identifying symmetric over asymmetric patterns. The absence of the vertical axis memory advantage in the early blind may depend on their total lack of visual experience or on the effect of prolonged visual deprivation. To disentangle this issue, in this study, we measured the ability of late blind individuals to remember tactile spatial patterns that were either vertically or horizontally symmetric or asymmetric. Late blind participants showed better memory performance for symmetric patterns. An additional advantage for the vertical axis of symmetry over the horizontal one was reported, but only for patterns presented in the frontal plane. In the horizontal plane, no difference was observed between vertical and horizontal symmetric patterns, due to the latter being recalled particularly well. These results are discussed in terms of the influence of the spatial reference frame adopted during exploration. Overall, our data suggest that prior visual experience is sufficient to drive the vertical symmetry memory advantage, at least when an external reference frame based on geocentric cues (i.e., gravity) is adopted.

Spectral properties of embedded Gaussian unitary ensemble of random matrices with Wigner's SU(4) symmetry

International Nuclear Information System (INIS)

Vyas, Manan; Kota, V.K.B.

2010-01-01

For m fermions in Ω number of single particle orbitals, each fourfold degenerate, we introduce and analyze in detail embedded Gaussian unitary ensemble of random matrices generated by random two-body interactions that are SU(4) scalar [EGUE(2)-SU(4)]. Here the SU(4) algebra corresponds to the Wigner's supermultiplet SU(4) symmetry in nuclei. Embedding algebra for the EGUE(2)-SU(4) ensemble is U(4Ω) contains U(Ω) x SU(4). Exploiting the Wigner-Racah algebra of the embedding algebra, analytical expression for the ensemble average of the product of any two m particle Hamiltonian matrix elements is derived. Using this, formulas for a special class of U(Ω) irreducible representations (irreps) {4 r , p}, p = 0, 1, 2, 3 are derived for the ensemble averaged spectral variances and also for the covariances in energy centroids and spectral variances. On the other hand, simplifying the tabulations of Hecht for SU(Ω) Racah coefficients, numerical calculations are carried out for general U(Ω) irreps. Spectral variances clearly show, by applying Jacquod and Stone prescription, that the EGUE(2)-SU(4) ensemble generates ground state structure just as the quadratic Casimir invariant (C 2 ) of SU(4). This is further corroborated by the calculation of the expectation values of C 2 [SU(4)] and the four periodicity in the ground state energies. Secondly, it is found that the covariances in energy centroids and spectral variances increase in magnitude considerably as we go from EGUE(2) for spinless fermions to EGUE(2) for fermions with spin to EGUE(2)-SU(4) implying that the differences in ensemble and spectral averages grow with increasing symmetry. Also for EGUE(2)-SU(4) there are, unlike for GUE, non-zero cross-correlations in energy centroids and spectral variances defined over spaces with different particle numbers and/or U(Ω) [equivalently SU(4)] irreps. In the dilute limit defined by Ω → ∞, r >> 1 and r/Ω → 0, for the {4 r , p} irreps, we have derived analytical

Implications of horizontal symmetries on baryon number violation in supersymmetric models

International Nuclear Information System (INIS)

Ben-Hamo, V.; Nir, Y.

1994-08-01

The smallness of the quark and lepton parameters and the hierarchy between them could be the result of selection rules due to a horizontal symmetry broken by a small parameter. The same selection rules apply to baryon number violating terms. Consequently, the problem of baryon number violation in supersymmetry may be solved naturally, without invoking any especially-designed extra symmetry. This mechanism is efficient enough even for low-scale flavor physics. Proton decay is likely to be dominated by the modes K + ν-bar i or K o μ + (e + ), and may proceed at observable rates. (authors). 15 refs

Charmless B→VP decays using flavor SU(3) symmetry

International Nuclear Information System (INIS)

Chiang Chengwei; Gronau, Michael; Luo Zumin; Rosner, Jonathan L.; Suprun, Denis A.

2004-01-01

The decays of B mesons to a charmless vector (V) and pseudoscalar (P) meson are analyzed within a framework of flavor SU(3) in which symmetry breaking is taken into account through ratios of decay constants in tree (T) amplitudes but exact SU(3) is assumed for color-suppressed and penguin amplitudes. The magnitudes and relative phases of tree and penguin amplitudes are extracted from data, the symmetry assumption is tested, and predictions are made for rates and CP asymmetries in as-yet-unseen decay modes. A key assumption for which we perform some tests and suggest others is a relation between penguin amplitudes in which the spectator quark is incorporated into either a pseudoscalar meson or a vector meson. Values of γ slightly restricting the range currently allowed by fits to other data are favored, but outside this range there remain acceptable solutions which cannot be excluded solely on the basis of present B→VP experiments

Radiative gauge symmetry breaking in supersymmetric flipped SU(5)

Energy Technology Data Exchange (ETDEWEB)

Drees, M.

1988-05-19

The radiative breaking of the SU(5)xU(1) symmetry in the flipped SU(5) model recently proposed by Antoniadis et al. is studied using renormalization group techniques. It is shown that gaugino masses can only be the dominant source of supersymmetry breaking at the Planck scale if the U(1) gaugino mass M/sub 1/ is at least 10 times larger than the SU(5) gaugino mass M/sub 5/. If M/sub 1/ approx. = M/sub 5/ at the Planck scale, non-vanishing trilinear soft breaking terms ('A-terms') are needed already at the Planck scale. In both cases consequences for the sparticle spectrum at the weak scale are discussed.

SU(4) flavor symmetry breaking in D-meson couplings to light hadrons

Energy Technology Data Exchange (ETDEWEB)

Fontoura, C.E. [Instituto Tecnologico da Aeronautica, DCTA, Sao Jose dos Campos, SP (Brazil); Universidade Estadual Paulista, Instituto de Fisica Teorica, Sao Paulo, SP (Brazil); Haidenbauer, J. [Institute for Advanced Simulation, Institut fuer Kernphysik, and Juelich Center for Hadron Physics, Forschungszentrum Juelich, Juelich (Germany); Krein, G. [Universidade Estadual Paulista, Instituto de Fisica Teorica, Sao Paulo, SP (Brazil)

2017-05-15

The validity of SU(4)-flavor symmetry relations of couplings of charmed D-mesons to light mesons and baryons is examined with the use of {sup 3}P{sub 0} quark-pair creation model and nonrelativistic quark-model wave functions. We focus on the three-meson couplings ππρ, KKρ and DDρ and baryon-baryon-meson couplings NNπ, NΛK and NΛ{sub c}D. It is found that SU(4)-flavor symmetry is broken at the level of 30% in the DDρ tree-meson couplings and 20% in the baryon-baryon-meson couplings. Consequences of these findings for DN cross sections and existence of bound states D-mesons in nuclei are discussed. (orig.)

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

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.

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

N=2 supergravity in superspace and the BRS symmetry

International Nuclear Information System (INIS)

Kachkachi, M.; Lhallabi, T.

1989-07-01

The quantum N = 2 Einstein supergravity action is constructed by requiring the BRS symmetry. This latter is derived by the use of the distorted horizontality conditions in the curved N = 2 harmonic superspace. (author). 16 refs

Family symmetries in F-theory GUTs

CERN Document Server

King, S F; Ross, G G

2010-01-01

We discuss F-theory SU(5) GUTs in which some or all of the quark and lepton families are assigned to different curves and family symmetry enforces a leading order rank one structure of the Yukawa matrices. We consider two possibilities for the suppression of baryon and lepton number violation. The first is based on Flipped SU(5) with gauge group SU(5)\\times U(1)_\\chi \\times SU(4)_{\\perp} in which U(1)_{\\chi} plays the role of a generalised matter parity. We present an example which, after imposing a Z_2 monodromy, has a U(1)_{\\perp}^2 family symmetry. Even in the absence of flux, spontaneous breaking of the family symmetry leads to viable quark, charged lepton and neutrino masses and mixing. The second possibility has an R-parity associated with the symmetry of the underlying compactification manifold and the flux. We construct an example of a model with viable masses and mixing angles based on the gauge group SU(5)\\times SU(5)_{\\perp} with a U(1)_{\\perp}^3 family symmetry after imposing a Z_2 monodromy.

Supersymmetry and intermediate symmetry breaking in SO(10) superunification

International Nuclear Information System (INIS)

Asatryan, H.M.; Ioannisyan, A.N.

1985-01-01

A scheme of simultaneous breakdown of intermediate symmetry SO(10) → SU(3)sub(c) x U(1) x SU(2)sub(L) x SU(2)sub(R) and supersymmetry by means of a single scale parameter is suggested. This intermediate symmetry, which is preferable physically, owing to the broken supersymmetry has a minimum lying lower than SU(4) x SU(2)sub(L) x SU(2)sub(R). The intermediate symmetry is broken by the vacuum expectation value of the Higgs superfields. Owing to the quantum corrections the potential minimum turns out to correspond to breakdown of the intermediate symmetry up to the standard group SU(3)sub(c) x SU(2)sub(L) x U(1)sub(y). The value of the Weinberg angle is less than that in the supersymmetric SU(5) model and agrees with the experiment

Dynamical generation of a composite quark-lepton symmetry

International Nuclear Information System (INIS)

Yasue, Masaki.

1981-05-01

We demonstrate the possibility that a basic [SU(2)]sup(N) symmetry of N subconstituents, which describes particle and antiparticle transitions, generates at most an ''effective'' SO(2N) symmetry and at least an ''effective'' SU(N) x U(1) symmetry of composite quarks and leptons whose states are specified by the N different kinds of subconstituents. The generators of the ''effective'' symmetry, are identified by the correct algebraic properties specific to SO(2N) of composite operators constructed from the [SU(2)]sup(N)-operators acting on the composite quark-lepton states. The composite quarks and leptons are found to respect SO(4) x SO(6) or SU(2)sub(L) x U(1)sub(R) x SU(3)sub(c) x U(1)sub(B-L) according to a new selection rule, which are generated by the bilinear products of the raising and lowering operators of [SU(2)] 5 . This construction of the SO(4) x SO(6) generators allows us to uniquely define the five quantum numbers of that symmetry even at the subconstituent level. The full SO(10) generators can be also constructed; however, one needs a newly arranged [SU(2)] 5 symmetry only defined at the composite level, the generators of which turn out to be at most N body operators of the original [SU(2)] 5 . (author)

Exotic pairing in 1D spin-3/2 atomic gases with SO(4 symmetry

Directory of Open Access Journals (Sweden)

Yuzhu Jiang

2015-06-01

Full Text Available Tuning interactions in the spin singlet and quintet channels of two colliding atoms could change the symmetry of the one-dimensional spin-3/2 fermionic systems of ultracold atoms while preserving the integrability. Here we find a novel SO(4 symmetry integrable point in the spin-3/2 Fermi gas and derive the exact solution of the model using the Bethe ansatz. In contrast to the model with SU(4 and SO(5 symmetries, the present model with SO(4 symmetry preserves spin singlet and quintet Cooper pairs in two sets of SU(2⊗SU(2 spin subspaces. We obtain full phase diagrams, including the Fulde–Ferrel–Larkin–Ovchinnikov like pair correlations, spin excitations and quantum criticality through the generalized Yang–Yang thermodynamic equations. In particular, various correlation functions are calculated by using finite-size corrections in the frame work of conformal field theory. Moreover, within the local density approximation, we further find that spin singlet and quintet pairs form subtle multiple shell structures in density profiles of the trapped gas.

Averaging in SU(2) open quantum random walk

International Nuclear Information System (INIS)

Ampadu Clement

2014-01-01

We study the average position and the symmetry of the distribution in the SU(2) open quantum random walk (OQRW). We show that the average position in the central limit theorem (CLT) is non-uniform compared with the average position in the non-CLT. The symmetry of distribution is shown to be even in the CLT

Averaging in SU(2) open quantum random walk

Science.gov (United States)

Clement, Ampadu

2014-03-01

We study the average position and the symmetry of the distribution in the SU(2) open quantum random walk (OQRW). We show that the average position in the central limit theorem (CLT) is non-uniform compared with the average position in the non-CLT. The symmetry of distribution is shown to be even in the CLT.

SU(3) flavour symmetry breaking and charmed states

Energy Technology Data Exchange (ETDEWEB)

Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Najjar, J. [Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Hyogo (Japan); Perlt, H.; Schiller, A. [Leipzig Univ. (Germany). Inst. fuer Theoretische Physik; Pleiter, D. [Forschungszentrum Juelich GmbH (Germany). Juelich Supercomputing Centre (JSC); Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Stueben, H. [Hamburg Univ. (Germany). Regionales Rechenzentrum; Zanotti, J.M. [Adelaide Univ. (Australia). CSSM, School of Chemistry and Physics; Collaboration: QCDSF-UKQCD Collaborations

2013-11-15

By extending the SU(3) flavour symmetry breaking expansion from up, down and strange sea quark masses to partially quenched valence quark masses we propose a method to determine charmed quark hadron masses including possible QCD isospin breaking effects. Initial results for some open charmed pseudoscalar meson states and singly and doubly charmed baryon states are encouraging and demonstrate the potential of the procedure. Essential for the method is the determination of the scale using singlet quantities, and to this end we also give here a preliminary estimation of the recently introduced Wilson flow scales.

An improved estimate of SU(4) symmetry mixing in light nuclei

International Nuclear Information System (INIS)

Haq, R.; Parikh, J.C.; Bhatt, K.H.

1974-01-01

The spectral distribution method of French has been very successful in determining ground state energies and mixing intensities of various irreps of a group near the ground state. For the SU(4) group these methods have been extensively used. The method incorporated actually estimates an upper limit for the mixing and lower amounts of mixing cannot be ruled out. This is beacuse the total variance sigmasup(2) which is composed of sigmasup(2) external and sigmasup(2) internal is used for estimating the amount of mixing. Whereas sigmasup(2) int gives rise to spreading of various irreps, it is only sigmasup(2) ext which leads to symmetry mixing. Better methods of estimating the mixing shall be discussed. (author)

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.

Decoupling of parity- and SU(2)/sub R/-breaking scales: A new approach to left-right symmetric models

International Nuclear Information System (INIS)

Chang, D.; Mohapatra, R.N.; Parida, M.K.

1984-01-01

A new approach to left-right symmetric models is proposed, where the left-right discrete-symmetry- and SU(2)/sub R/-breaking scales are decoupled from each other. This changes the spectrum of physical Higgs bosons which leads to different patterns for gauge hierarchies in SU(2)/sub L/xSU(2)/sub R/xSU(4)/sub C/ and SO(10) models. Most interesting are two SO(10) symmetry-breaking chains with an intermediate U(1)/sub R/ symmetry. These are such as to provide new motivation to search for ΔB = 2 and right-handed current effects at low energies

Coleman-Weinberg symmetry breaking in SU(8) induced by a third rank antisymmetric tensor scalar field II: the fermion spectrum

Science.gov (United States)

Adler, Stephen L.

2017-07-01

We continue our study of Coleman-Weinberg symmetry breaking induced by a third rank antisymmetric tensor scalar, in the context of the SU(8) model (Adler 2014 Int. J. Mod. Phys. A 29 1450130) we proposed earlier. We focus in this paper on qualitative features that will determine whether the model can make contact with the observed particle spectrum. We discuss the mechanism for giving the spin \\frac{3}{2} field a mass by the BEH mechanism, and analyze the remaining massless spin \\frac{1}{2} fermions, the global chiral symmetries, and the running couplings after symmetry breaking. We note that the smallest gluon mass matrix eigenvalue has an eigenvector suggestive of U(1) B-L , and conjecture that the theory runs to an infrared fixed point at which there is a massless gluon with 3 to  -1 ratios in generator components. Assuming this, we discuss a mechanism for making contact with the standard model, based on a conjectured asymmetric breaking of Sp(4) to SU(2) subgroups, one of which is the electroweak SU(2), and the other of which is a ‘technicolor’ group that binds the original SU(8) model fermions, which play the role of ‘preons’, into composites. Quarks can emerge as 5 preon composites and leptons as 3 preon composites, with consequent stability of the proton against decay to a single lepton plus a meson. A composite Higgs boson can emerge as a two preon composite. Since anomaly matching for the relevant conserved global symmetry current is not obeyed by three fermion families, emergence of three composite families requires formation of a Goldstone boson with quantum numbers matching this current, which can be a light dark matter candidate.

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)

Horizontal, anomalous U(1) symmetry for the more minimal supersymmetric standard model

International Nuclear Information System (INIS)

Nelson, A.E.; Wright, D.

1997-01-01

We construct explicit examples with a horizontal, open-quotes anomalousclose quotes U(1) gauge group, which, in a supersymmetric extension of the standard model, reproduce qualitative features of the fermion spectrum and CKM matrix, and suppress FCNC and proton decay rates without the imposition of global symmetries. We review the motivation for such open-quotes moreclose quotes minimal supersymmetric standard models and their predictions for the sparticle spectrum. There is a mass hierarchy in the scalar sector which is the inverse of the fermion mass hierarchy. We show in detail why ΔS=2 FCNCs are greatly suppressed when compared with naive estimates for nondegenerate squarks. copyright 1997 The American Physical Society

arXiv Global $SU(2)_L \\otimes$BRST symmetry and its LSS theorem: Ward-Takahashi identities governing Green's functions, on-shell T-Matrix elements, and $V_{eff}$, in the scalar-sector of certain spontaneously broken non-Abelian gauge theories

CERN Document Server

Güngör, Özenç; Starkman, Glenn D.; Stora, Raymond

This work is dedicated to the memory of Raymond Stora (1930-2015). $SU(2)_L$ is the simplest spontaneous symmetry breaking (SSB) non-Abelian gauge theory: a complex scalar doublet $\\phi=\\frac{1}{\\sqrt{2}}\\begin{bmatrix}H+i\\pi_3-\\pi_2 +i\\pi_1\\end{bmatrix}\\equiv\\frac{1}{\\sqrt{2}}\\tilde{H}e^{2i\\tilde{t}\\cdot\\tilde{\\vec{\\pi}}/}\\begin{bmatrix}10\\end{bmatrix}$ and a vector $\\vec{W}^\\mu$. In Landau gauge, $\\vec{W}^\\mu$ is transverse, $\\vec{\\tilde{\\pi}}$ are massless derivatively coupled Nambu-Goldstone bosons (NGB). A global shift symmetry enforces $m^{2}_{\\tilde{\\pi}}=0$. We observe that on-shell T-matrix elements of physical states $\\vec{W}^\\mu$,$\\phi$ are independent of global $SU(2)_{L}$ transformations, and the associated global current is exactly conserved for amplitudes of physical states. We identify two towers of "1-soft-pion" global Ward-Takahashi Identities (WTI), which govern the $\\phi$-sector, and represent a new global symmetry, $SU(2)_L\\otimes$BRST, a symmetry not of the Lagrangian but of the physical...

The offset-midpoint traveltime pyramid in 3D transversely isotropic media with a horizontal symmetry axis

KAUST Repository

Hao, Qi

2014-12-30

Analytic representation of the offset-midpoint traveltime equation for anisotropy is very important for prestack Kirchhoff migration and velocity inversion in anisotropic media. For transversely isotropic media with a vertical symmetry axis, the offset-midpoint traveltime resembles the shape of a Cheops’ pyramid. This is also valid for homogeneous 3D transversely isotropic media with a horizontal symmetry axis (HTI). We extended the offset-midpoint traveltime pyramid to the case of homogeneous 3D HTI. Under the assumption of weak anellipticity of HTI media, we derived an analytic representation of the P-wave traveltime equation and used Shanks transformation to improve the accuracy of horizontal and vertical slownesses. The traveltime pyramid was derived in the depth and time domains. Numerical examples confirmed the accuracy of the proposed approximation for the traveltime function in 3D HTI media.

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.

Itinerant ferromagnetism in fermionic systems with SP (2 N) symmetry

Science.gov (United States)

Yang, Wang; Wu, Congjun

The Ginzburg-Landau free energy of systems with SP (2 N) symmetry describes a second order phase transition on the mean field level, since the Casimir invariants of the SP (2 N) group can be only of even order combinations of the generators of the SP (2 N) group. This is in contrast with systems having the SU (N) symmetry, where the allowance of cubic term generally makes the phase transition into first order. In this work, we consider the Hertz-Millis type itinerant ferromagnetism in an interacting fermionic system with SP (2 N) symmetry, where the ferromagnetic orders are enriched by the multi-component nature of the system. The quantum criticality is discussed near the second order phase transition point.

Large top quark Yukawa coupling and horizontal symmetries

International Nuclear Information System (INIS)

Rasin, A.

1997-05-01

We consider the maximal U(3) horizontal scheme as a handle on fermion masses and mixings. In particular, we attempt to explain the large top Yukawa coupling and the masses and mixing in the two heaviest generations. A simple model is constructed by enlarging the matter content of the Standard Model with that of a 10 + 10-bar pair of SU(5). The third generation particles get their masses when (U(3) is broken to U(2). Top quark mass is naturally of order one. Bottom and tau masses are suppressed because of a hierarchy in the effective Yukawa couplings and not from the hierarchy in the Higgs doublet vacuum expectation values. The hierarchy is a consequence of the fact that the particle spectrum contains an incomplete vector-like generation and can come from hierarchies between scales of breaking of different grand unified groups. Hierarchies and mixings between the second and third generation are obtained by introducing a single parameters is an element' representing the breaking U(2) → U(1). As a consequence, we show that the successful (and previously obtained) relations V cb approx. m s /m b approx. √ m c /m t easily follow from our scheme. (author). 39 refs, 5 figs

Quantum Monte Carlo detection of SU(2 symmetry breaking in the participation entropies of line subsystems

Directory of Open Access Journals (Sweden)

David J. Luitz, Nicolas Laflorencie

2017-03-01

Full Text Available Using quantum Monte Carlo simulations, we compute the participation (Shannon-R\\'enyi entropies for groundstate wave functions of Heisenberg antiferromagnets for one-dimensional (line subsystems of length $L$ embedded in two-dimensional ($L\\times L$ square lattices. We also study the line entropy at finite temperature, i.e. of the diagonal elements of the density matrix, for three-dimensional ($L\\times L\\times L$ cubic lattices. The breaking of SU(2 symmetry is clearly captured by a universal logarithmic scaling term $l_q\\ln L$ in the R\\'enyi entropies, in good agreement with the recent field-theory results of Misguish, Pasquier and Oshikawa [arXiv:1607.02465]. We also study the dependence of the log prefactor $l_q$ on the R\\'enyi index $q$ for which a transition is detected at $q_c\\simeq 1$.

Broken colour symmetry and liberated quarks

International Nuclear Information System (INIS)

Ma, E.

1976-01-01

A quark model of hadrons is presented and discussed, in which local SU(3) gauge symmetry is completely broken and yet asymptotic freedom is preserved. There is no infrared slavery in this model, and isolated quarks are free to exist. Colour becomes a global symmetry which is only approximate under SU(3) but nearly exact under SU(2) x U(1), as far as the usual hadron spectroscopy is concerned. (Auth.)

Wave Function and Emergent SU(2) Symmetry in the ν_{T}=1 Quantum Hall Bilayer.

Science.gov (United States)

Lian, Biao; Zhang, Shou-Cheng

2018-02-16

We propose a trial wave function for the quantum Hall bilayer system of total filling factor ν_{T}=1 at a layer distance d to magnetic length ℓ ratio d/ℓ=κ_{c1}≈1.1, where the lowest charged excitation is known to have a level crossing. The wave function has two-particle correlations, which fit well with those in previous numerical studies, and can be viewed as a Bose-Einstein condensate of free excitons formed by composite bosons and anticomposite bosons in different layers. We show the free nature of these excitons indicating an emergent SU(2) symmetry for the composite bosons at d/ℓ=κ_{c1}, which leads to the level crossing in low-lying charged excitations. We further show the overlap between the trial wave function, and the ground state of a small size exact diagonalization is peaked near d/ℓ=κ_{c1}, which supports our theory.

SU(4)

Indian Academy of Sciences (India)

Abstract. We introduce in this paper embedded Gaussian unitary ensemble of random matrices, for m fermions in Ω number of single particle orbits, generated by random two- body interactions that are SU(4) scalar, called EGUE(2)-SU(4). Here the SU(4) algebra corresponds to Wigner's supermultiplet SU(4) symmetry in ...

Dark revelations of the [SU(3)]3 and [SU(3)]4 gauge extensions of the standard model

Science.gov (United States)

Kownacki, Corey; Ma, Ernest; Pollard, Nicholas; Popov, Oleg; Zakeri, Mohammadreza

2018-02-01

Two theoretically well-motivated gauge extensions of the standard model are SU(3)C × SU(3)L × SU(3)R and SU(3)q × SU(3)L × SU(3)l × SU(3)R, where SU(3)q is the same as SU(3)C and SU(3)l is its color leptonic counterpart. Each has three variations, according to how SU(3)R is broken. It is shown here for the first time that a built-in dark U(1)D gauge symmetry exists in all six versions. However, the corresponding symmetry breaking pattern does not reduce properly to that of the standard model, unless an additional Z2‧ symmetry is defined, so that U(1)D ×Z2‧ is broken to Z2 dark parity. The available dark matter candidates in each case include fermions, scalars, as well as vector gauge bosons. This work points to the possible unity of matter with dark matter, the origin of which may not be ad hoc.

Dark revelations of the [SU(3]3 and [SU(3]4 gauge extensions of the standard model

Directory of Open Access Journals (Sweden)

Corey Kownacki

2018-02-01

Full Text Available Two theoretically well-motivated gauge extensions of the standard model are SU(3C×SU(3L×SU(3R and SU(3q×SU(3L×SU(3l×SU(3R, where SU(3q is the same as SU(3C and SU(3l is its color leptonic counterpart. Each has three variations, according to how SU(3R is broken. It is shown here for the first time that a built-in dark U(1D gauge symmetry exists in all six versions. However, the corresponding symmetry breaking pattern does not reduce properly to that of the standard model, unless an additional Z2′ symmetry is defined, so that U(1D×Z2′ is broken to Z2 dark parity. The available dark matter candidates in each case include fermions, scalars, as well as vector gauge bosons. This work points to the possible unity of matter with dark matter, the origin of which may not be ad hoc.

Lie-algebra approach to symmetry breaking

International Nuclear Information System (INIS)

Anderson, J.T.

1981-01-01

A formal Lie-algebra approach to symmetry breaking is studied in an attempt to reduce the arbitrariness of Lagrangian (Hamiltonian) models which include several free parameters and/or ad hoc symmetry groups. From Lie algebra it is shown that the unbroken Lagrangian vacuum symmetry can be identified from a linear function of integers which are Cartan matrix elements. In broken symmetry if the breaking operators form an algebra then the breaking symmetry (or symmetries) can be identified from linear functions of integers characteristic of the breaking symmetries. The results are applied to the Dirac Hamiltonian of a sum of flavored fermions and colored bosons in the absence of dynamical symmetry breaking. In the partially reduced quadratic Hamiltonian the breaking-operator functions are shown to consist of terms of order g 2 , g, and g 0 in the color coupling constants and identified with strong (boson-boson), medium strong (boson-fermion), and fine-structure (fermion-fermion) interactions. The breaking operators include a boson helicity operator in addition to the familiar fermion helicity and ''spin-orbit'' terms. Within the broken vacuum defined by the conventional formalism, the field divergence yields a gauge which is a linear function of Cartan matrix integers and which specifies the vacuum symmetry. We find that the vacuum symmetry is chiral SU(3) x SU(3) and the axial-vector-current divergence gives a PCAC -like function of the Cartan matrix integers which reduces to PCAC for SU(2) x SU(2) breaking. For the mass spectra of the nonets J/sup P/ = 0 - ,1/2 + ,1 - the integer runs through the sequence 3,0,-1,-2, which indicates that the breaking subgroups are the simple Lie groups. Exact axial-vector-current conservation indicates a breaking sum rule which generates octet enhancement. Finally, the second-order breaking terms are obtained from the second-order spin tensor sum of the completely reduced quartic Hamiltonian

Mercado consumidor de carne suína e derivados em Belo Horizonte

OpenAIRE

Faria,I.G.; Ferreira,J.M.; Garcia,S.K.

2006-01-01

Avaliou-se o comportamento do mercado consumidor de carne suína e seus derivados em Belo Horizonte. Foram entrevistados 401 consumidores, homens e mulheres, maiores de 19 anos de idade, mantendo-se a proporcionalidade observada no censo populacional. Além de sexo e faixa etária, escolaridade, ocupação e renda familiar foram levantadas para compor os fatores condicionantes da pesquisa. A carne suína in natura é consumida até três vezes por semana pela maioria da população (61,6%), em função de...

Baryon axial-vector couplings and SU(3)-symmetry breaking in chiral quark models

International Nuclear Information System (INIS)

Horvat, D.; Ilakovac, A.; Tadic, D.

1986-01-01

SU(3)-symmetry breaking is studied in the framework of the chiral bag models. Comparisons are also made with the MIT bag model and the harmonic-oscillator quark model. An important clue for the nature of the symmetry breaking comes from the isoscalar axial-vector coupling constant g/sub A//sup S/ which can be indirectly estimated from the Bjorken sum rules for deep-inelastic scattering. The chiral bag model with two radii reasonably well accounts for the empirical values of g/sub A//sup S/ and of the axial-vector coupling constants measured in hyperon semileptonic decays

SU(2,R)q symmetries of non-Abelian Toda theories

International Nuclear Information System (INIS)

Gomes, J.F.; Zimerman, A.H.; Sotkov, G.M.

1998-03-01

The classical and quantum algebras of a class of conformal NA-Toda models are studied. It is shown that the SL (2,R) q . Poisson brackets algebra generated by certain chiral and antichiral charges of the nonlocal currents and the global U(1) charge appears as an algebra of the symmetries of these models. (author)

R-symmetry violation in N=2 SUSY

International Nuclear Information System (INIS)

Volkov, G.G.; Maslikov, A.A.

1990-01-01

The present paper discusses the spontaneous R-symmetry violation in the N=2 SUSY SU(4)xU(1) model with soft SUSY breaking terms preserving finiteness. (In this case an invisible axion appears). In particular, the mechanism producting a light photino mass up to some GeV is suggested. In R-odd version of this model the mechanisms of enhancement of the neutrino decay is discussed. 10 refs.; 3 figs

Chiral-symmetry restoration in baryon-rich environments

International Nuclear Information System (INIS)

Kogut, J.; Matsuoka, H.; Stone, M.; Wyld, H.W.; Shenker, S.; Shigemitsu, J.; Sinclair, D.K.

1983-04-01

Chiral symmetry restoration in an environment rich in baryons is studied by computer simulation methods in SU(2) and SU(3) gauge theories in the quenched approximation. The basic theory of symmetry restoration as a function of chemical potential is illustrated and the implementation of the ideas on a lattice is made explicit. A simple mean field model is presented to guide one's expectations. The second order conjugate-gradient iterative method and the pseudo-fermion Monte Carlo procedure are convergent methods of calculating the fermion propagator in an environment rich in baryons. Computer simulations of SU(3) gauge theory show an abrupt chiral symmetry restoring transition and the critical chemical potential and induced baryon density are estimated crudely. A smoother transition is observed for the color group SU(2)

Experimentally verifiable Yang-Mills spin 2 gauge theory of gravity with group U(1) x SU(2)

International Nuclear Information System (INIS)

Peng, H.

1988-01-01

In this work, a Yang-Mills spin 2 gauge theory of gravity is proposed. Based on both the verification of the helicity 2 property of the SU(2) gauge bosons of the theory and the agreement of the theory with most observational and experimental evidence, the authors argues that the theory is truly a gravitational theory. An internal symmetry group, the eigenvalues of its generators are identical with quantum numbers, characterizes the interactions of a given class. The author demonstrates that the 4-momentum P μ of a fermion field generates the U(1) x SU(2) internal symmetry group for gravity, but not the transformation group T 4 . That particles are classified by mass and spin implies that the U(1) x SU(2), instead of the Poincare group, is a symmetry group of gravity. It is shown that the U(1) x SU(2) group represents the time displacement and rotation in ordinary space. Thereby internal space associated with gravity is identical with Minkowski spacetime, so a gauge potential of gravity carries two space-time indices. Then he verifies that the SU(2) gravitational boson has helicity 2. It is this fact, spin from internal spin, that explains alternatively why the gravitational field is the only field which is characterized by spin 2. The Physical meaning of gauge potentials of gravity is determined by comparing theory with the results of experiments, such as the Collella-Overhauser-Werner (COW) experiment and the Newtonian limit, etc. The gauge potentials this must identify with ordinary gravitational potentials

Symmetry chains and adaptation coefficients

International Nuclear Information System (INIS)

Fritzer, H.P.; Gruber, B.

1985-01-01

Given a symmetry chain of physical significance it becomes necessary to obtain states which transform properly with respect to the symmetries of the chain. In this article we describe a method which permits us to calculate symmetry-adapted quantum states with relative ease. The coefficients for the symmetry-adapted linear combinations are obtained, in numerical form, in terms of the original states of the system and can thus be represented in the form of numerical tables. In addition, one also obtains automatically the matrix elements for the operators of the symmetry groups which are involved, and thus for any physical operator which can be expressed either as an element of the algebra or of the enveloping algebra. The method is well suited for computers once the physically relevant symmetry chain, or chains, have been defined. While the method to be described is generally applicable to any physical system for which semisimple Lie algebras play a role we choose here a familiar example in order to illustrate the method and to illuminate its simplicity. We choose the nuclear shell model for the case of two nucleons with orbital angular momentum l = 1. While the states of the entire shell transform like the smallest spin representation of SO(25) we restrict our attention to its subgroup SU(6) x SU(2)/sub T/. We determine the symmetry chains which lead to total angular momentum SU(2)/sub J/ and obtain the symmetry-adapted states for these chains

Symmetry chains for the atomic shell model. I. Classification of symmetry chains for atomic configurations

International Nuclear Information System (INIS)

Gruber, B.; Thomas, M.S.

1980-01-01

In this article the symmetry chains for the atomic shell model are classified in such a way that they lead from the group SU(4l+2) to its subgroup SOsub(J)(3). The atomic configurations (nl)sup(N) transform like irreducible representations of the group SU(4l+2), while SOsub(J)(3) corresponds to total angular momentum in SU(4l+2). The defining matrices for the various embeddings are given for each symmetry chain that is obtained. These matrices also define the projection onto the weight subspaces for the corresponding subsymmetries and thus relate the various quantum numbers and determine the branching of representations. It is shown in this article that three (interrelated) symmetry chains are obtained which correspond to L-S coupling, j-j coupling, and a seniority dependent coupling. Moreover, for l<=6 these chains are complete, i.e., there are no other chains but these. In articles to follow, the symmetry chains that lead from the group SO(8l+5) to SOsub(J)(3) will be discussed, with the entire atomic shell transforming like an irreducible representation of SO(8l+5). The transformation properties of the states of the atomic shell will be determined according to the various symmetry chains obtained. The symmetry lattice discussed in this article forms a sublattice of the larger symmetry lattice with SO(8l+5) as supergroup. Thus the transformation properties of the states of the atomic configurations, according to the various symmetry chains discussed in this article, will be obtained too. (author)

Hierarchy of symmetry-breaking scales in SO(10) grand unification and particle masses

International Nuclear Information System (INIS)

Asatryan, G.M.; Ioannisyan, A.N.

1987-01-01

An SO(10) grand unification model is proposed in which the introduction of an additional discrete symmetry solves the problem of the quark mass spectrum arising in SO(10) breaking schemes with intermediate SU(4) x SU(2)/sub L/ x SU(2)/sub R/ or SU(3)/sub C/ x U(1)/sub B//sub -//sub L/ x SU(2)/sub L/ x SU(2)/sub R/ symmetry. When the breaking of this discrete symmetry is taken into account the condition that there exist only a single light Higgs boson leads to a relation between the b- and t-quark masses which makes it possible to fix the ratio of the grand unification scale M/sub X/ and the quark--lepton symmetry-breaking scale M/sub C/. The specific values of M/sub X/ and M/sub C/ and also the scale of the SU(2)/sub R/ symmetry breaking M/sub R/ depend on the experimental value of the Weinberg angle and are in agreement with the experimental data on proton decay

Low-energy restoration of parity and maximal symmetry

International Nuclear Information System (INIS)

Raychaudhuri, A.; Sarkar, U.

1982-01-01

The maximal symmetry of fermions of one generation, SU(16), which includes the left-right-symmetric Pati-Salam group, SU(4)/sub c/ x SU(2) /sub L/ x SU(2)/sub R/, as a subgroup, allows the possibility of a low-energy (M/sub R/approx.100 GeV) breaking of the left-right symmetry. It is known that such a low-energy restoration of parity can be consistent with weak-interaction phenomenology. We examine different chains of descent of SU(16) that admit a low value of M/sub R/ and determine the other intermediate symmetry-breaking mass scales associated with each of these chains. These additional mass scales provide an alternative to the ''great desert'' expected in some grand unifying models. The contributions of the Higgs fields in the renormalization-group equations are retained and are found to be important

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

Diversity of off-shell twisted (4,4) multiplets in SU(2)xSU(2) harmonic superspace

International Nuclear Information System (INIS)

Ivanov, E.A.; Sutulin, A.O.

2004-01-01

We elaborate on four different types of twisted N=(4,4) supermultiplets in the SU(2)xSU(2), 2D harmonic superspace. In the conventional N=(4,4), 2D superspace they are described by the superfields q ia , q Ia , q IA , subjected to proper differential constraints, (i, I, a, A) being the doublet indices of four groups SU(2) which form the full R-symmetry group SO(4) L xSO(4) R of N=(4,4) supersymmetry. We construct the torsionful off-shell sigma-model actions for each type of these multiplets, as well as the corresponding invariant mass terms, in an analytic subspace of the SU(2)xSU(2) harmonic superspace. As an instructive example, N=(4,4) superconformal extension of the SU(2)xU(1) WZNW sigma-model action and its massive deformation are presented for the multiplet q iA . We prove that N=(4,4) supersymmetry requires the general sigma-model action of pair of different multiplets to split into a sum of sigma-model actions of each multiplet. This phenomenon also persists if a larger number of non-equivalent multiplets are simultaneously included. We show that different multiplets may interact with each other only through mixed mass terms which can be set up for multiplets belonging to 'self-dual' pairs (q ia , q IA ) and (q Ia , q iA ). The multiplets from different pairs cannot interact at all. For a 'self-dual' pair of the twisted multiplets we give the most general form of the on-shell scalar potential

SU(5)c color model constraints from UA2

International Nuclear Information System (INIS)

Foot, R.; Hernandez, O.F.; Rizzo, T.G.; Ames Lab., IA; Iowa State Univ. of Science and Technology, Ames

1991-01-01

We investigate the possibility that the color gauge group SU(3) may arise as a consequence of the spontaneous symmetry breaking of SU(5) c . In an earlier paper we examine the constraints imposed on the SU(5) c color model by recent measurements of the dijet mass distribution at CDF. We found that the CDF data did not exclude any region of parameter space in the model. Here we consider similar data from UA2 and find that it leads to the constraint Msub(Z') > or approx. 280 GeV. (orig.)

A minimal spontaneous CP violation model with small neutrino mass and SU(2) x U(1) x Z3 symmetry

International Nuclear Information System (INIS)

Geng, C.Q.; Ng, J.N.

1988-04-01

It is shown that spontaneous CP violation and natural flavor conservation can occur in the SU(2) L x U(1) Y model based on two Higgs doublet and one Higgs singlet fields with a Z 3 discrete symmetry. Physical CP nonconservation is purely due to scalar-pseudoscalar mixings. In order for this to be a major source of CP violation a light spin-O boson of mass less than 10 GeV is required. The see-saw mechanism can be implemented to generate small neutrino masses. The model implies a relatively large electric dipole moment for charged leptons and small value for ε'/ε

Vacuum expectation values of Higgs scalars in a SU(2)/sub L/ x SU(2)/sub R/ x U(1) gauge model

International Nuclear Information System (INIS)

Kitazoe, T.; Mainland, G.B.; Tanaka, K.

1979-01-01

We determine the vacuum expectation values of the Higgs scalars within the framework of a six-quark SU(2)/sub L/ x SU(2)/sub R/ x U(1) gauge model after the imposition of discrete symmetries that are necessary in order to express the Cabibbo angle in terms of quark mass ratios and phases of the vacuum expectation values. We find both real and complex solutions for the vacuum expectation values depending on the relative values of the parameters in the Higgs potential

Gauge origin of discrete flavor symmetries in heterotic orbifolds

Directory of Open Access Journals (Sweden)

Florian Beye

2014-09-01

Full Text Available We show that non-Abelian discrete symmetries in orbifold string models have a gauge origin. This can be understood when looking at the vicinity of a symmetry enhanced point in moduli space. At such an enhanced point, orbifold fixed points are characterized by an enhanced gauge symmetry. This gauge symmetry can be broken to a discrete subgroup by a nontrivial vacuum expectation value of the Kähler modulus T. Using this mechanism it is shown that the Δ(54 non-Abelian discrete symmetry group originates from a SU(3 gauge symmetry, whereas the D4 symmetry group is obtained from a SU(2 gauge symmetry.

Parastatistics and gauge symmetries

International Nuclear Information System (INIS)

Govorkov, A.B.

1982-01-01

A possible formulation of gauge symmetries in the Green parafield theory is analysed and the SO(3) gauge symmetry is shown to be on a distinct status. The Greenberg paraquark hypothesis turns out to be not equivalent to the hypothesis of quark colour SU(3)sub(c) symmetry. Specific features of the gauge SO(3) symmetry are discussed, and a possible scheme where it is an exact subgroup of the broken SU(3)sub(c) symmetry is proposed. The direct formulation of the gauge principle for the parafield represented by quaternions is also discussed

Strongly coupled SU(2v boson and LEP1 versus LEP2

Directory of Open Access Journals (Sweden)

M. Bilenky

1993-10-01

Full Text Available If new strong interactions exist in the electroweak bosonic sector (e.g., strong Higgs sector, dynamical electroweak breaking, etc., it is natural to expect new resonances, with potentially strong couplings. We consider an additional vector-boson triplet, V+-, V0, associated with an SU(2v local symmetry under the specific (but rather natural assumption that ordinary fermions are SU(2v singlets. Mixing of the V triplet with the W+-, Z0 bosons effectively leads to an SU(2L×U(1Y violating vector-boson-fermion interaction which is strongly bounded by LEP1 data. In contrast, the potentially large deviation of the Z0W+W- coupling from its SU(2L×U(1Y value is hardly constrained by LEP1 data. Results from experiments with direct access to the trilinear Z0W+W− coupling (LEP200, NLC are urgently needed.

Quantizations of D = 3 Lorentz symmetry

Energy Technology Data Exchange (ETDEWEB)

Lukierski, J. [University of Wroclaw, Institute for Theoretical Physics, Wroclaw (Poland); Tolstoy, V.N. [University of Wroclaw, Institute for Theoretical Physics, Wroclaw (Poland); Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow (Russian Federation)

2017-04-15

Using the isomorphism o(3; C) ≅ sl(2; C) we develop a new simple algebraic technique for complete classification of quantum deformations (the classical r-matrices) for real forms o(3) and o(2,1) of the complex Lie algebra o(3; C) in terms of real forms of sl(2; C): su(2), su(1,1) and sl(2; R). We prove that the D = 3 Lorentz symmetry o(2,1) ≅ su(1,1) ≅ sl(2; R) has three different Hopf-algebraic quantum deformations, which are expressed in the simplest way by two standard su(1,1) and sl(2; R) q-analogs and by simple Jordanian sl(2; R) twist deformation. These quantizations are presented in terms of the quantum Cartan-Weyl generators for the quantized algebras su(1,1) and sl(2; R) as well as in terms of quantum Cartesian generators for the quantized algebra o(2,1). Finally, some applications of the deformed D = 3 Lorentz symmetry are mentioned. (orig.)

Physical symmetry groups and associated bundles in field theory

International Nuclear Information System (INIS)

Crumeyrolle, A.

1986-01-01

A previous paper, ''Some geometrical consequences of physical symmetries'' describes in some detail invariant submanifolds of the linear representation space C /sup 4m/ for the physical symmetry group : SU(2,2)xSU(m) and its subgroup PxSU(m). In this paper the author intends to give a geometric version using homogeneous spaces and a spinorial approach. Some concrete orbits by means of spinor structures considered in the modern scope and some plausible physical consequences are discussed

Boson symmetries in exotic N∼Z nuclei

International Nuclear Information System (INIS)

Van Isacker, P.

1996-01-01

Heavy N ∼ Z nuclei provide an ideal testing ground for various symmetries such as isospin and isospin-spin or SU(4) symmetry. The associated quantum numbers of orbital angular momentum L, isospin T, spin S AND SU(4) labels (λμnu)can be carried over onto appropriate versions of the interacting boson model (IBM). Symmetries allow to relate the boson model to the shell model; the composite character of the bosons permits a broader application of the concept of symmetry in IBM. The discussion then focuses on IBM-3 (which includes T = 1 bosons only) and IBM-4 (with T = 0 and T = 1 bosons). A connection is established between them which relies on an IBM-4 classification that breaks Wigner's SU(4) symmetry. The resulting generalised IBM-4 is relevant for studying the competition between T = 0 and T = 1 pairing in N ∼ Z nuclei. An application to odd-odd self-conjugate nuclei is presented. (author). 20 refs., 2 tabs

Analysis on B → VV with the Flavour SU(3) Symmetry

International Nuclear Information System (INIS)

Shao-Min, Liu; Hong-Ying, Jin; Xue-Qian, Li

2008-01-01

It is noted that the rescattering and annihilation effects are significant in the penguin-dominant B → VV decays. In this work, we suggest to use a unique operator at the quark level to describe all the rescattering and the penguin-induced annihilation effects in B → φK * , and the coefficient of the operator depends on the polarizations of the produced mesons. By the flavour SU(3) symmetry, we apply the same scenario to all the penguin-dominant B → VV modes. (the physics of elementary particles and fields)

Quregisters, Symmetry Groups and Clifford Algebras

International Nuclear Information System (INIS)

Cervantes, D; Morales-Luna, G

2016-01-01

Natural one-to-one and two-to-one homomorphisms from SO(3) into SU(2) are built conventionally, and the collection of qubits, is identified with a subgroup of SU(2). This construction is suitable to be extended to corresponding tensor powers. The notions of qubits, quregisters and qugates are translated into the language of symmetry groups. The corresponding elements to entangled states in the tensor product of Hilbert spaces reflect entanglement properties as well, and in this way a notion of entanglement is realised in the tensor product of symmetry groups. (paper)

SU(5) monopoles, magnetic symmetry and confinement

International Nuclear Information System (INIS)

Daniel, M.; Lazarides, G.; Shafi, Q.

1980-01-01

The monopoles of the unified SU(5) gauge theory broken down to Hsub(E) = SU(3)sub(c) x U(1)sub(EM) [or to Ksub(E) = SU(3)sub(c) x SU(2) x U(1)sub(γ)], are classified. They belong to representations of a magnetic group Hsub(M)(Ksub(M)), which is found to be isomorphic to Hsub(E)(Ksub(E)). For SU(5) broken down to Hsub(E), there exists a regular and stable monopole which is a colour magnetic triplet, and carries a non-zero abelian magnetic charge. It is suggested that composite operators made out of this monopole and its antiparticle fields develop a non-zero vacuum expectation value, and so lead to a squeezing of the colour electric flux. Finally, we comment on the cosmological production of SU(5) monopoles. (orig.)

Broken SU(8) symmetry and the new particles

International Nuclear Information System (INIS)

Kramer, G.; Schiller, D.H.

1976-05-01

We study the mass spectra and wave functions for vector and pseudoscalar mesons in broken SU(8) (SU(8) is contained in SU(4)F * SU(2)J), where F stands for flavour and J for usual spin. The connection with the standard mass breaking in SU(4)F is worked out. We find that even in the presence of strong SU(8) breaking the ideal mixing scheme for the vector mesons can be approximately retained. For the pseudoscalar mesons the mixing of the singlet with the 63-plet representation of SU(8) turns out to be essential and stongly nonideal. (orig.) [de

Model for extended Pati-Salam gauge symmetry

International Nuclear Information System (INIS)

Foot, R.; Lew, H.; Volkas, R.R.

1990-11-01

The possibility of constructing non-minimal models of the Pati-Salam type is investigated. The most interesting examples are found to have an SU(6) x SU(2) L x SU(2) R guage invariance. Two interesting symmetry breaking patterns are analysed: one leading to the theory of SU(5) colour at an intermediate scale, the other to the quark-lepton symmetric model. 15 refs

Towards the establishment of nonlinear hidden symmetries of the Skyrme model

International Nuclear Information System (INIS)

Herrera-Aguilar, A.; Kanakoglou, K.; Paschalis, J. E.

2006-01-01

We present a preliminary attempt to establish the existence of hidden nonlinear symmetries of the SU(N) Skyrme model which could, in principle, lead to the further integration of the system. An explicit illustration is given for the SU(2) symmetry group

Spontaneous mirror left-right symmetry breaking for leptogenesis parametrized by Majorana neutrino mass matrix

Science.gov (United States)

Gu, Pei-Hong

2017-10-01

We introduce a mirror copy of the ordinary fermions and Higgs scalars for embedding the SU(2) L × U(1) Y electroweak gauge symmetry into an SU(2) L × SU(2) R × U(1) B-L left-right gauge symmetry. We then show the spontaneous left-right symmetry breaking can automatically break the parity symmetry motivated by solving the strong CP problem. Through the SU(2) R gauge interactions, a mirror Majorana neutrino can decay into a mirror charged lepton and two mirror quarks. Consequently we can obtain a lepton asymmetry stored in the mirror charged leptons. The Yukawa couplings of the mirror and ordinary charged fermions to a dark matter scalar then can transfer the mirror lepton asymmetry to an ordinary lepton asymmetry which provides a solution to the cosmic baryon asymmetry in association with the SU(2) L sphaleron processes. In this scenario, the baryon asymmetry can be well described by the neutrino mass matrix up to an overall factor.

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.)

Residual Z{sub 2} symmetries and leptonic mixing patterns from finite discrete subgroups of U(3)

Energy Technology Data Exchange (ETDEWEB)

Joshipura, Anjan S. [Physical Research Laboratory,Navarangpura, Ahmedabad 380 009 (India); Patel, Ketan M. [Indian Institute of Science Education and Research, Mohali,Knowledge City, Sector 81, S A S Nagar, Manauli 140 306 (India)

2017-01-30

We study embedding of non-commuting Z{sub 2} and Z{sub m}, m≥3 symmetries in discrete subgroups (DSG) of U(3) and analytically work out the mixing patterns implied by the assumption that Z{sub 2} and Z{sub m} describe the residual symmetries of the neutrino and the charged lepton mass matrices respectively. Both Z{sub 2} and Z{sub m} are assumed to be subgroups of a larger discrete symmetry group G{sub f} possessing three dimensional faithful irreducible representation. The residual symmetries predict the magnitude of a column of the leptonic mixing matrix U{sub PMNS} which are studied here assuming G{sub f} as the DSG of SU(3) designated as type C and D and large number of DSG of U(3) which are not in SU(3). These include the known group series Σ(3n{sup 3}), T{sub n}(m), Δ(3n{sup 2},m), Δ(6n{sup 2},m) and Δ{sup ′}(6n{sup 2},j,k). It is shown that the predictions for a column of |U{sub PMNS}| in these group series and the C and D types of groups are all contained in the predictions of the Δ(6N{sup 2}) groups for some integer N. The Δ(6N{sup 2}) groups therefore represent a sufficient set of G{sub f} to obtain predictions of the residual symmetries Z{sub 2} and Z{sub m}.

Operator realization of the SU(2) WZNW model

International Nuclear Information System (INIS)

Furlan, P.; Hadjiivanov, L.K.; Todorov, I.T.

1996-01-01

Decoupling the chiral dynamics in the canonical approach to the WZNW model requires an extended phase space that includes left and right monodromy variables M and M. Earlier work on the subject, which traced back the quantum group symmetry of the model to the Lie-Poisson symmetry of the chiral symplectic form, left some open questions: - How to reconcile the necessity to set MM -1 =1 (in order to recover the monodromy invariance of the local 2D group valued field g=uu) with the fact the M and M obey different exchange relations? - What is the status of the quantum symmetry in the 2D theory in which the chiral fields u(x-t) and u(x+t) commute? - Is there a consistent operator formalism in the chiral (and the extended 2D) theory in the continuum limit? We propose a constructive affirmative answer to these questions for G=SU(2) by presenting the quantum fields u and u as sums of products of chiral vertex operators and q-Bose creation and annihilation operators. (orig.)

SU(N) Irreducible Schwinger Bosons

OpenAIRE

Mathur, Manu; Raychowdhury, Indrakshi; Anishetty, Ramesh

2010-01-01

We construct SU(N) irreducible Schwinger bosons satisfying certain U(N-1) constraints which implement the symmetries of SU(N) Young tableaues. As a result all SU(N) irreducible representations are simple monomials of $(N-1)$ types of SU(N) irreducible Schwinger bosons. Further, we show that these representations are free of multiplicity problems. Thus all SU(N) representations are made as simple as SU(2).

Effective SU(2) theory for the pseudogap state

Science.gov (United States)

Montiel, X.; Kloss, T.; Pépin, C.

2017-03-01

This paper exposes in a detailed manner the recent findings about the SU(2) scenario for the underdoped phase of the cuprate superconductors. The SU(2) symmetry is formulated as a rotation between the d -wave superconducting (SC) phase and a d -wave charge order. We define the operators responsible for the SU(2) rotations and we derive the nonlinear σ model associated with it. In this framework, we demonstrate that SU(2) fluctuations are massless in finite portions of the Brillouin zone corresponding to the antinodal regions (0 ,π ) and (π ,0 ). We argue that the presence of SU(2) fluctuations in the antinodal region leads to the opening of Fermi arcs around the Fermi surface and to the formation of the pseudogap. Moreover, we show that SU(2) fluctuations lead, in turn, to the emergence of a finite momentum SC order—or pair density wave (PDW)—and more importantly to a new kind of excitonic particle-hole pairs liquid, the resonant excitonic state (RES), which is made of patches of preformed particle-hole pairs with multiple momenta. When the RES liquid becomes critical, we demonstrate that electronic scattering through the critical modes leads to anomalous transport properties. This new finding can account for the strange metal (SM) phase at finite temperature, on the right-hand side of the SC dome, shedding light on another notoriously mysterious part of the phase diagram of the cuprates.

Broken SU(5) x SU(5) chiral symmetry and the classification of B mesons

International Nuclear Information System (INIS)

Hatzis, M.

1984-01-01

We consider broken SU(5) x SU(5) chiral summetry and we assume that the vacuum is SU(5)-symmetric. Using the observed mass spectrum of pseudoscalar mesons, and setting the bu mass in the range 5.2 +- 0.06 GeV, we predict the masses of bs, bc, and etasub(b) states as well as axial current couplings fsub(i)/fsub(π). SU(5) x SU(5) is found to be consistent with SU(4) x SU(4) breaking. The problem of eta - eta' - eta sub(c) - eta sub(b) mixing is also discussed

Sub-color and leptoquark-quark symmetry

International Nuclear Information System (INIS)

Nakamura, Fumihiko

1982-01-01

On the basis of leptoquark-quark symmetry, we propose possible models, in which leptons and gauge bosons are constructed is SU(2) symmetry. In one of the cases, the subcolor is introduced as the quantum number of the leptoquark. Then the possibility of baryon decay is discussed. (author)

SP(6) X SU(2) and SO(8) X SU(2) - symmetric fermion-dynamic model of multinucleon systems

International Nuclear Information System (INIS)

Baktybaev, K.

2007-01-01

In last years a new approach describing collective states of multinucleon system on the base of their fermion dynamic symmetry was developed. Such fermion model is broad and logical one in comparison with the phenomenological model of interacting bosons. In cut fermion S- and D- pair spaces complicated nucleons interactions are approximating in that way so multinucleon system Hamiltonian becomes a simple function of fermion generators forming corresponding Lie algebra. Correlation fermion pairs are structured in such form so its operators of birth and destruction together with a set multiband operators are formed Sp(6) and SO(8) algebra of these pairs and SU(2)-algebra for so named anomalous pairs. For convenience at the model practical application to concrete systems the dynamical-symmetric Hamiltonian is writing by means of independent Casimir operators of subgroup are reductions of a large group. It is revealed, that observed Hamiltonians besides the known SU 3 , and SO 6 asymptotic borders have also more complicated 'vibration-like' borders SO 7 , SO 5 XSU 2 and SU 2 XSO 3 . In the paper both advantages and disadvantages of these borders and some its applications to specific nuclear systems are discussing

Weak interaction models with spontaneously broken left-right symmetry

International Nuclear Information System (INIS)

Mohapatra, R.H.

1978-01-01

The present status of weak interaction models with spontaneously broken left-right symmetry is reviewed. The theoretical basis for asymptotic parity conservation, manifest left-right symmetry in charged current weak interactions, natural parity conservation in neutral currents and CP-violation in the context of SU(2)/sub L/ circled x SU (2)/sub R/ circled x U(1) models are outlined in detail. Various directions for further research in the theoretical and experimental side are indicated

Charge commutation relation approach to composite vector bosons in SU(2)sub(L)xU(1)sub(Y)

International Nuclear Information System (INIS)

Yasue, Masaki; Oneda, Sadao.

1984-09-01

Under the assumption that the local SU(2)sub(L)xU(1)sub(Y) symmetry is a good symmetry for new resonances, we predict that msub(W)msub(W*)=costhetamsub(Z)msub(Z*) where theta represents the mixing angle between neutral gauge bosons and msub(W), msub(Z), msub(W*) and msub(Z*) are the masses of W, Z, W* and Z*, respectively. W* and Z* are the lowest lying spin one resonances, whose pure states belong to a triplet of SU(2)sub(L). Possible SU(2)sub(L)-singlet state is assumed to be much heavier than W* and Z*. Low energy phenomenology of weak interactions indicates msub(W)--costhetamsub(Z), suggesting msub(W*)--msub(Z*). (author)

Systematic model building with flavor symmetries

Energy Technology Data Exchange (ETDEWEB)

Plentinger, Florian

2009-12-19

The observation of neutrino masses and lepton mixing has highlighted the incompleteness of the Standard Model of particle physics. In conjunction with this discovery, new questions arise: why are the neutrino masses so small, which form has their mass hierarchy, why is the mixing in the quark and lepton sectors so different or what is the structure of the Higgs sector. In order to address these issues and to predict future experimental results, different approaches are considered. One particularly interesting possibility, are Grand Unified Theories such as SU(5) or SO(10). GUTs are vertical symmetries since they unify the SM particles into multiplets and usually predict new particles which can naturally explain the smallness of the neutrino masses via the seesaw mechanism. On the other hand, also horizontal symmetries, i.e., flavor symmetries, acting on the generation space of the SM particles, are promising. They can serve as an explanation for the quark and lepton mass hierarchies as well as for the different mixings in the quark and lepton sectors. In addition, flavor symmetries are significantly involved in the Higgs sector and predict certain forms of mass matrices. This high predictivity makes GUTs and flavor symmetries interesting for both, theorists and experimentalists. These extensions of the SM can be also combined with theories such as supersymmetry or extra dimensions. In addition, they usually have implications on the observed matter-antimatter asymmetry of the universe or can provide a dark matter candidate. In general, they also predict the lepton flavor violating rare decays {mu} {yields} e{gamma}, {tau} {yields} {mu}{gamma}, and {tau} {yields} e{gamma} which are strongly bounded by experiments but might be observed in the future. In this thesis, we combine all of these approaches, i.e., GUTs, the seesaw mechanism and flavor symmetries. Moreover, our request is to develop and perform a systematic model building approach with flavor symmetries and

Systematic model building with flavor symmetries

International Nuclear Information System (INIS)

Plentinger, Florian

2009-01-01

The observation of neutrino masses and lepton mixing has highlighted the incompleteness of the Standard Model of particle physics. In conjunction with this discovery, new questions arise: why are the neutrino masses so small, which form has their mass hierarchy, why is the mixing in the quark and lepton sectors so different or what is the structure of the Higgs sector. In order to address these issues and to predict future experimental results, different approaches are considered. One particularly interesting possibility, are Grand Unified Theories such as SU(5) or SO(10). GUTs are vertical symmetries since they unify the SM particles into multiplets and usually predict new particles which can naturally explain the smallness of the neutrino masses via the seesaw mechanism. On the other hand, also horizontal symmetries, i.e., flavor symmetries, acting on the generation space of the SM particles, are promising. They can serve as an explanation for the quark and lepton mass hierarchies as well as for the different mixings in the quark and lepton sectors. In addition, flavor symmetries are significantly involved in the Higgs sector and predict certain forms of mass matrices. This high predictivity makes GUTs and flavor symmetries interesting for both, theorists and experimentalists. These extensions of the SM can be also combined with theories such as supersymmetry or extra dimensions. In addition, they usually have implications on the observed matter-antimatter asymmetry of the universe or can provide a dark matter candidate. In general, they also predict the lepton flavor violating rare decays μ → eγ, τ → μγ, and τ → eγ which are strongly bounded by experiments but might be observed in the future. In this thesis, we combine all of these approaches, i.e., GUTs, the seesaw mechanism and flavor symmetries. Moreover, our request is to develop and perform a systematic model building approach with flavor symmetries and to search for phenomenological

On the SL(2,R) symmetry in Yang-Mills theories in the Landau, Curci-Ferrari and maximal abelian gauge

International Nuclear Information System (INIS)

Dudal, David; Verschelde, Henri; Rodino Lemes, Vitor Emanuel; Sarandy, Marcelo S.; Sorella, Silvio Paolo; Picariello, Marco

2002-01-01

The existence of a SL(2;R) symmetry is discussed in SU(N) Yang-Mills in the maximal abelian gauge. This symmetry, also present in the Landau and Curci-Ferrari gauge, ensures the absence of tachyons in the maximal abelian gauge. In all these gauges, SL(2;R) turns out to be dynamically broken by ghost condensates. (author)

Operator realization of the SU(2) WZNW model

International Nuclear Information System (INIS)

Furlan, P.; Todorov, I.T.

1995-12-01

Decoupling the chiral dynamics in the canonical approach to the WZNW model requires an extended phase space that includes left and right monodromy variables M and M-bar. Earlier work on the subject, which traced back the quantum group symmetry of the model to the Lie-Poisson symmetry of the chiral symplectic form, left some open questions: How to reconcile the necessity to set M M-bar -1 = 1 (in order to recover the monodromy invariance of the local 2D group valued field g = uu-bar) with the fact the M and M-bar obey different exchange relations? What is the status of the quantum symmetry in the 2D theory in which the chiral fields u(x-t) and u-bar(x+t) commute? Is there a consistent operator formalism in the chiral (and the extended 2D) theory in the continuum limit? We propose a constructive affirmative answer to these questions for G = SU(2) by presenting the quantum field u and u-bar as sums of products of chiral vertex operators and q Bose creation and annihilation operators. (author). 17 refs

The spectral density of the QCD Dirac operator and patterns of chiral symmetry breaking

International Nuclear Information System (INIS)

Toublan, D.; Verbaarschot, J.J.M.

1999-01-01

We study the spectrum of the QCD Dirac operator for two colors with fermions in the fundamental representation and for two or more colors with adjoint fermions. For N f flavors, the chiral flavor symmetry of these theories is spontaneously broken according to SU (2N f → Sp (2N f ) and SU (N f → O (N f ), respectively, rather than the symmetry breaking pattern SU (N f ) x SU (N f ) → SU (N f ) for QCD with three or more colors and fundamental fermions. In this paper we study the Dirac spectrum for the first two symmetry breaking patterns. Following previous work for the third case we find the Dirac spectrum in the domain λ QCD by means of partially quenched chiral perturbation theory. In particular, this result allows us to calculate the slope of the Dirac spectrum at λ = 0. We also show that for λ 2 Λ QCD (wing L the linear size of the system) the Dirac spectrum is given by a chiral Random Matrix Theory with the symmetries of the Dirac operator

Dynamical symmetries of the shell model

International Nuclear Information System (INIS)

Van Isacker, P.

2000-01-01

The applications of spectrum generating algebras and of dynamical symmetries in the nuclear shell model are many and varied. They stretch back to Wigner's early work on the supermultiplet model and encompass important landmarks in our understanding of the structure of the atomic nucleus such as Racah's SU(2) pairing model and Elliot's SU(3) rotational model. One of the aims of this contribution has been to show the historical importance of the idea of dynamical symmetry in nuclear physics. Another has been to indicate that, in spite of being old, this idea continues to inspire developments that are at the forefront of today's research in nuclear physics. It has been argued in this contribution that the main driving features of nuclear structure can be represented algebraically but at the same time the limitations of the symmetry approach must be recognised. It should be clear that such approach can only account for gross properties and that any detailed description requires more involved numerical calculations of which we have seen many fine examples during this symposium. In this way symmetry techniques can be used as an appropriate starting point for detailed calculations. A noteworthy example of this approach is the pseudo-SU(3) model which starting from its initial symmetry Ansatz has grown into an adequate and powerful description of the nucleus in terms of a truncated shell model. (author)

Couplings in D(2,1;α) superconformal mechanics from the SU(2) perspective

Energy Technology Data Exchange (ETDEWEB)

Galajinsky, Anton [Laboratory of Mathematical Physics, Tomsk Polytechnic University,Lenin Ave. 30, 634050 Tomsk (Russian Federation)

2017-03-09

Dynamical realizations of the most general N=4 superconformal group in one dimension D(2,1;α) are reconsidered from the perspective of the R-symmetry subgroup SU(2). It is shown that any realization of the R-symmetry subalgebra in some phase space can be extended to a representation of the Lie superalgebra corresponding to D(2,1;α). Novel couplings of arbitrary number of supermultiplets of the type (1,4,3) and (0,4,4) to a single supermultiplet of either the type (3,4,1), or (4,4,0) are constructed. D(2,1;α) superconformal mechanics describing superparticles propagating near the horizon of the extreme Reissner-Nordström-AdS-dS black hole in four and five dimensions is considered. The parameter α is linked to the cosmological constant.

Parity violations in electron-nucleon scattering and the SU(2)sub(L)xSU(2)sub(R)xU(1)sub(L+R) electroweak symmetry

International Nuclear Information System (INIS)

Rajpoot, S.

1981-07-01

The SU(2)sub(L) x SU(2)sub(R) x U(1)sub(L+R) model of electroweak interactions is described with the most general gauge couplings gsub(L), gsub(R) and gsub(L+R). The case in which neutrino neutral current interactions are identical to the standard SU(2)sub(L) x U(1)sub(L+R) model is discussed in detail. It is shown that with the weak angle lying in the experimental range sin 2 thetaSUB(w)=0.23+-0.015 and 1 2 /gsub(R) 2 <3 it is possible to explain the amount of parity violation observed at SLAC and at the same time predict values of the ''weak charge'' in bismuth to lie in the range admitted by the controversal data from different experiments. (author)

Heavy axions from strong broken horizontal gauge symmetry

International Nuclear Information System (INIS)

Elliott, T.; King, S.F.

1993-01-01

We study the consequences of the existence and breaking of a Peccei-Quinn symmetry within the context of a dynamical model of electroweak symmetry breaking based on broken gauged flavour symmetries. We perform an estimate of the axion mass by including flavour instanton effects and show that, for low cut-offs, the axion is sufficiently massive to prevent it from being phenomenologically unacceptable. We conclude with an examination of the strong CP problem and show that our axion cannot solve the problem, though we indicate ways in which the model can be extended so that the strong CP problem is solved. (orig.)

Classification of three-family grand unification in string theory. II. The SU(5) and SU(6) models

International Nuclear Information System (INIS)

Kakushadze, Z.; Tye, S.H.

1997-01-01

Requiring that supersymmetric SU(5) and SU(6) grand unifications in the heterotic string theory must have three chiral families, adjoint (or higher representation) Higgs fields in the grand unified gauge group, and a non-Abelian hidden sector, we construct such string models within the framework of free conformal field theory and asymmetric orbifolds. Within this framework, we construct all such string models via Z 6 asymmetric orbifolds that include a Z 3 outerautomorphism, the latter yielding a level-three current algebra for the grand unification gauge group SU(5) or SU(6). We then classify all such Z 6 asymmetric orbifolds that result in models with a non-Abelian hidden sector. All models classified in this paper have only one adjoint (but no other higher representation) Higgs field in the grand unified gauge group. This Higgs field is neutral under all other gauge symmetries. The list of hidden sectors for three-family SU(6) string models are SU(2), SU(3), and SU(2)circle-times SU(2). In addition to these, three-family SU(5) string models can also have an SU(4) hidden sector. Some of the models have an apparent anomalous U(1) gauge symmetry. copyright 1997 The American Physical Society

Minimal unitary representation of D(2,1;λ) and its SU(2) deformations and d=1, N=4 superconformal models

International Nuclear Information System (INIS)

Govil, Karan; Gunaydin, Murat

2013-01-01

Quantization of the geometric quasiconformal realizations of noncompact groups and supergroups leads directly to their minimal unitary representations (minreps). Using quasiconformal methods massless unitary supermultiplets of superconformal groups SU(2,2|N) and OSp(8 ⁎ |2n) in four and six dimensions were constructed as minreps and their U(1) and SU(2) deformations, respectively. In this paper we extend these results to SU(2) deformations of the minrep of N=4 superconformal algebra D(2,1;λ) in one dimension. We find that SU(2) deformations can be achieved using n pair of bosons and m pairs of fermions simultaneously. The generators of deformed minimal representations of D(2,1;λ) commute with the generators of a dual superalgebra OSp(2n ⁎ |2m) realized in terms of these bosons and fermions. We show that there exists a precise mapping between symmetry generators of N=4 superconformal models in harmonic superspace studied recently and minimal unitary supermultiplets of D(2,1;λ) deformed by a pair of bosons. This can be understood as a particular case of a general mapping between the spectra of quantum mechanical quaternionic Kähler sigma models with eight super symmetries and minreps of their isometry groups that descends from the precise mapping established between the 4d, N=2 sigma models coupled to supergravity and minreps of their isometry groups.

Heavy quark spin symmetry and SU(3)-flavour partners of the X(3872)

Energy Technology Data Exchange (ETDEWEB)

Hidalgo-Duque, C., E-mail: carloshd@ific.uv.es [Instituto de Física Corpuscular (IFIC), Centro Mixto CSIC-Universidad de Valencia, Institutos de Investigación de Paterna, Aptd. 22085, E-46071 Valencia (Spain); Nieves, J. [Instituto de Física Corpuscular (IFIC), Centro Mixto CSIC-Universidad de Valencia, Institutos de Investigación de Paterna, Aptd. 22085, E-46071 Valencia (Spain); Pavón Valderrama, M. [Institut de Physique Nucléaire, Université Paris-Sud, IN2P3/CNRS, F-91406 Orsay Cedex (France)

2013-09-20

In this work, an Effective Field Theory (EFT) incorporating light SU(3)-flavour and heavy quark spin symmetries is used to describe charmed meson–antimeson bound states. At Lowest Order (LO), this means that only contact range interactions among the heavy meson and antimeson fields are involved. Besides, the isospin violating decays of the X(3872) will be used to constrain the interaction between the D and a D{sup ¯⁎} mesons in the isovector channel. Finally, assuming that the X(3915) and Y(4140) resonances are D{sup ⁎}D{sup ¯⁎} and D{sub s}{sup ⁎}D{sup ¯}{sub s}{sup ⁎} molecular states, we can determine the four Low Energy Constants (LECs) of the EFT that appear at LO and, therefore, the full spectrum of molecular states with isospin I=0, 1/2 and 1.

SU(3)xSU(2) color symmetry and Usub(B)(1)xSUsub(f)(4) quark model of hadrons

International Nuclear Information System (INIS)

Khrushchov, V.V.

1982-01-01

A quark model with a generalized color group SUsub(c)(3)xSU'sub(c)(2) is treated in the framework of the SUsub(f)(4)xUsub(B)(1) symnetry of strong interactions. The model contains twelve standard u, d, s, c quarks and new quarks belonging to representation 6 of the SU(4) group. The properties of new quarks are considered with respect to the color group and some properties of the exotic states, predicted by the model are presented

Center-symmetric effective theory for high-temperature SU(2) Yang-Mills theory

International Nuclear Information System (INIS)

Forcrand, Ph. de; Kurkela, A.; Vuorinen, A.

2008-01-01

We construct and study a dimensionally reduced effective theory for high-temperature SU(2) Yang-Mills theory that respects all the symmetries of the underlying theory. Our main motivation is to study whether the correct treatment of the center symmetry can help extend the applicability of the dimensional reduction procedure towards the confinement transition. After performing perturbative matching to the full theory at asymptotically high temperatures, we map the phase diagram of the effective theory using nonperturbative lattice simulations. We find that at lower temperature the theory undergoes a second-order confining phase transition, in complete analogy with the full theory, which is a direct consequence of having incorporated the center symmetry

Spontaneous symmetry breaking and fermion chirality in higher-dimensional gauge theory

International Nuclear Information System (INIS)

Wetterich, C.

1985-01-01

The number of chiral fermions may change in the course of spontaneous symmetry breaking. We discuss solutions of a six-dimensional Einstein-Yang-Mills theory based on SO(12). In the resulting effective four-dimensional theory they can be interpreted as spontaneous breaking of a gauge group SO(10) to H=SU(3)sub(C)xSU(2)sub(L)xU(1)sub(R)xU(1)sub(B-L). For all solutions, the fermions which are chiral with respect to H form standard generations. However, the number of generations for the solutions with broken SO(10) may be different compared to the symmetric solutions. All solutions considered here exhibit a local generation group SU(2)sub(G)xU(1)sub(G). For the solutions with broken SO(10) symmetry, the leptons and quarks within one generation transform differently with respect to SU(2)sub(G)xU(1)sub(G). Spontaneous symmetry breaking also modifies the SO(10) relations among Yukawa couplings. All this has important consequences for possible fermion mass relations obtained from higher-dimensional theories. (orig.)

Axions from chiral family symmetry

International Nuclear Information System (INIS)

Chang, D.; Pal, P.B.; Maryland Univ., College Park; Senjanovic, G.

1985-01-01

We investigate the possibility that family symmetry, Gsub(F), is spontaneously broken chiral global symmetry. We classify the interesting cases when family symmetry can result in an automatic Peccei-Quinn symmetry U(1)sub(PQ) and thus provide a solution to the strong CP problem. The result disfavors having two or four families. For more than four families, U(1)sub(PQ) is in general automatic. In the case of three families, a unique Higgs sector allows U(1)sub(PQ) in the simplest case of Gsub(F)=[SU(3)] 3 . Cosmological consideration also puts strong constraint on the number of families. For Gsub(F)=[SU(N)] 3 cosmology singles out the three-family (N=3) case as a unique solution if there are three light neutrinos. Possible implication of decoupling theorem as applied to family symmetry breaking is also discussed. (orig.)

Determination of the chiral SU(4) x SU(4) breaking parameters

International Nuclear Information System (INIS)

Das, K.P.; Deshpande, N.G.

1978-06-01

Broken chiral SU(4) x SU(4) symmetry: from the observed mass spectrum of pseudoscalar charmed mesons the symmetry breakig parameters of the theory could be solved. It is found that both vacuum and Hamiltonian breaking play an important role as far as charmed states are concerned. Purely from the masses of D and F mesons the current algebra mass ratio m/sub c//m/sub s/ < 5 is deduced. This differs greatly from values obtained using linear or quadratic mass formulas. Considering eta, eta', and eta/sub c/ mixing a good solution with m/sub c//m/sub s/ approx. 3.2 and (anti cc)/anti uu) approx. 5.67 is further obtained. 18 references

Mercado consumidor de carne suína e derivados em Belo Horizonte Pork consumer market in Belo Horizonte, Brazil

Directory of Open Access Journals (Sweden)

I.G. Faria

2006-04-01

Full Text Available Avaliou-se o comportamento do mercado consumidor de carne suína e seus derivados em Belo Horizonte. Foram entrevistados 401 consumidores, homens e mulheres, maiores de 19 anos de idade, mantendo-se a proporcionalidade observada no censo populacional. Além de sexo e faixa etária, escolaridade, ocupação e renda familiar foram levantadas para compor os fatores condicionantes da pesquisa. A carne suína in natura é consumida até três vezes por semana pela maioria da população (61,6%, em função de seu sabor e versatilidade. A compra costuma ser feita num mesmo estabelecimento comercial, sendo preferidos os cortes feitos na hora. O consumo de derivados da carne suína é maior que o da carne in natura em razão da grande variedade de produtos. Os consumidores acreditam que a carne suína in natura e derivados sejam perigosos à saúde pelo excesso de gordura ou de colesterol (38,4% e por transmitir doenças (27,8%. Sexo, idade e renda familiar têm influência no consumo, mas não escolaridade e ocupação. As marcas dos produtos derivados aumentam a confiabilidade e indicam a origem, para a maioria dos consumidores. A população, embora mais atenta aos conceitos de alimentação saudável e segura, não conhece o significado e a função da rastreabilidade e certificação de origem dos produtos. Para aumentar o consumo e justificar a criação de programa de certificação da carne suína e derivados em Minas Gerais, é necessário campanha dirigida de marketing para eliminar os preconceitos em relação a estes produtos.This study aimed to assess the behavior of the consumer in relation to pork and pork products. Four hundred and one consumers, men and women over 19 years old, were randomly sampled from the residents of Belo Horizonte, Minas Gerais, to supply information about pork and pork products consumption, besides school background, occupation and family income. Consumption of fresh pork was directly affected by concepts related

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)

Relativistic chiral SU(3) symmetry, large Nc sum rules and meson-baryon scattering

International Nuclear Information System (INIS)

Lutz, M.F.M.; Kolomeitsev, E.E.

2001-05-01

The relativistic chiral SU(3) Lagrangian is used to describe kaon-nucleon scattering imposing constraints from the pion-nucleon sector and the axial-vector coupling constants of the baryon octet states. We solve the covariant coupled-channel Bethe-Salpeter equation with the interaction kernel truncated at chiral order Q 3 where we include only those terms which are leading in the large N c limit of QCD. The baryon decuplet states are an important explicit ingredient in our scheme, because together with the baryon octet states they form the large N c baryon ground states of QCD. Part of our technical developments is a minimal chiral subtraction scheme within dimensional regularization, which leads to a manifest realization of the covariant chiral counting rules. All SU(3) symmetry-breaking effects are well controlled by the combined chiral and large N c expansion, but still found to play a crucial role in understanding the empirical data. We achieve an excellent description of the data set typically up to laboratory momenta of p lab ≅ 500 MeV. (orig.)

Family gauge symmetry as an origin of Koide's mass formula and charged lepton spectrum

International Nuclear Information System (INIS)

Sumino, Y.

2009-01-01

Koide's mass formula is an empirical relation among the charged lepton masses which holds with a striking precision. We present a model of charged lepton sector within an effective field theory with U(3) x SU(2) family gauge symmetry, which predicts Koide's formula within the present experimental accuracy. Radiative corrections as well as other corrections to Koide's mass formula have been taken into account. We adopt a known mechanism, through which the charged lepton spectrum is determined by the vacuum expectation value of a 9-component scalar field Φ. On the basis of this mechanism, we implement the following mechanisms into our model: (1) The radiative correction induced by family gauge interaction cancels the QED radiative correction to Koide's mass formula, assuming a scenario in which the U(3) family gauge symmetry and SU(2) L weak gauge symmetry are unified at 10 2 -10 3 TeV scale; (2) A simple potential of Φ invariant under U(3) x SU(2) leads to a realistic charged lepton spectrum, consistent with the experimental values, assuming that Koide's formula is protected; (3) Koide's formula is stabilized by embedding U(3) x SU(2) symmetry in a larger symmetry group. Formally fine tuning of parameters in the model is circumvented (apart from two exceptions) by appropriately connecting the charged lepton spectrum to the boundary (initial) conditions of the model at the cut-off scale. We also discuss some phenomenological implications.

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...

Implications of Anomalous U(1) Symmetry in Unified Models the Flipped SU(5) x U(1) Paradigm

CERN Document Server

Ellis, Jonathan Richard; Rizos, J; Ellis, John

2000-01-01

A generic feature of string-derived models is the appearance of an anomalousAbelian U(1)_A symmetry which, among other properties, constrains the Yukawacouplings and distinguishes the three families from each other. In this paper,we discuss in a model-independent way the general constraints imposed by such aU(1)_A symmetry on fermion masses, R-violating couplings and proton-decayoperators in a generic flipped SU(5) x U(1)' model. We construct all possibleviable fermion mass textures and give various examples of effective low-energymodels which are distinguished from each other by their different predictionsfor B-, L- and R-violating effects. We pay particular attention to predictionsfor neutrino masses, in the light of the recent Super-Kamiokande data.

BOOK REVIEW: Symmetry Breaking

Science.gov (United States)

Ryder, L. H.

2005-11-01

One of the most fruitful and enduring advances in theoretical physics during the last half century has been the development of the role played by symmetries. One needs only to consider SU(3) and the classification of elementary particles, the Yang Mills enlargement of Maxwell's electrodynamics to the symmetry group SU(2), and indeed the tremendous activity surrounding the discovery of parity violation in the weak interactions in the late 1950s. This last example is one of a broken symmetry, though the symmetry in question is a discrete one. It was clear to Gell-Mann, who first clarified the role of SU(3) in particle physics, that this symmetry was not exact. If it had been, it would have been much easier to discover; for example, the proton, neutron, Σ, Λ and Ξ particles would all have had the same mass. For many years the SU(3) symmetry breaking was assigned a mathematical form, but the importance of this formulation fell away when the quark model began to be taken seriously; the reason the SU(3) symmetry was not exact was simply that the (three, in those days) quarks had different masses. At the same time, and in a different context, symmetry breaking of a different type was being investigated. This went by the name of `spontaneous symmetry breaking' and its characteristic was that the ground state of a given system was not invariant under the symmetry transformation, though the interactions (the Hamiltonian, in effect) was. A classic example is ferromagnetism. In a ferromagnet the atomic spins are aligned in one direction only—this is the ground state of the system. It is clearly not invariant under a rotation, for that would change the ground state into a (similar but) different one, with the spins aligned in a different direction; this is the phenomenon of a degenerate vacuum. The contribution of the spin interaction, s1.s2, to the Hamiltonian, however, is actually invariant under rotations. As Coleman remarked, a little man living in a ferromagnet would

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

Symmetry breaking patterns of the 3-3-1 model at finite temperature

Energy Technology Data Exchange (ETDEWEB)

Borges, J.S. [Universidade do Estado do Rio de Janeiro, Departamento de Fisica de Altas Energias, Rio de Janeiro, RJ (Brazil); Ramos, Rudnei O. [Universidade do Estado do Rio de Janeiro, Departamento de Fisica Teorica, Rio de Janeiro, RJ (Brazil)

2016-06-15

We consider the minimal version of an extension of the standard electroweak model based on the SU(3){sub c} x SU(3){sub L} x U(1){sub X} gauge symmetry (the 3-3-1 model). We analyze the most general potential constructed from three scalars in the triplet representation of SU(3){sub L}, whose neutral components develop nonzero vacuum expectation values, giving mass for all the model's massive particles. For different choices of parameters, we obtain the particle spectrum for the two symmetry breaking scales: one where the SU(3){sub L} x U(1){sub X} group is broken down to SU(2){sub L} x U(1){sub Y} and a lower scale similar to the standard model one. Within the considerations used, we show that the model encodes two first-order phase transitions, respecting the pattern of symmetry restoration. The last transition, corresponding to the standard electroweak one, is found to be very weak first-order, most likely turning second-order or a crossover in practice. However, the first transition in this model can be strongly first-order, which might happen at a temperature not too high above the second one. We determine the respective critical temperatures for symmetry restoration for the model. (orig.)

Broken symmetries and the Cabibbo angle

International Nuclear Information System (INIS)

Lanik, J.

1975-04-01

Under the assumption that the SU(3) symmetry is broken down by the strong and electromagnetic interactions, a phenomenological theory of the Cabibbo angle theta is proposed. In this theory the angle theta is fixed, linking together the Cabibbo rotation in the SU(3) space and complete SU(3) breaking consisting of both the SU(3) Hamiltonian and vacuum non-invariances. Assuming that the value of theta is zero in the soft-pion limit and that, in this limit, the only forces responsible for the isotopic symmetry breaking are the usual photonic forces it is shown that the usual electromagnetic interactions can contribute for the value of theta only through the non-vanishing vacuum expectation value of a certain scalar field. Within the framework of the (3,average3)+(3,average3) chiral symmetry-breaking model and through the use of the experimental value of the ratio GAMMA (K→μν)/GAMMA(π→μν), the presented Cabibbo angle theory predicts the value sintheta=0.25 which is in good agreement with experiment. (Lanik, J.)

On the Relativistic Origin of Pseudo spin Symmetry in Nuclei

International Nuclear Information System (INIS)

Leviatan, A.

1998-01-01

We review the concept of pseudo spin symmetry and its role in nuclear spectroscopy. We survey the attempts to arrive at a microscopic understanding of this symmetry. In particular, we show that pseudo spin symmetry in nuclei could arise from nucleons moving in a relativistic mean field which has an attractive scalar (Vs) and repulsive vector (Vv) potential nearly equal in magnitude but opposite in sign. We show that the generators of pseudo spin symmetry are the non-relativistic limit of the generators of an SU(2) symmetry which leaves invariant the Dirac Hamiltonian with Vs 2= -Vv. Furthermore within this framework, we demonstrate that this symmetry may be approximately conserved for realistic scalar and vector potentials

Symmetry of wavefunctions in quantum algebras and supersymmetry

International Nuclear Information System (INIS)

Zachos, C.K.

1992-01-01

The statistics-altering operators η present in the limit q = -1 of multiparticle SU q (2)- invariant subspaces parallel the action of such operators which naturally occur in supersymmetric theories. I illustrate this heuristically by comparison to a toy N = 2 superymmetry algebra, and ask whether there is a supersymmetry structure underlying SU q (2) in that limit. I remark on the relevance of such alternating-symmetry multiplets to the construction of invariant hamiltonians

Hyperdeformed nuclei and the residual pseudo-SU(3) symmetry

International Nuclear Information System (INIS)

Dudek, J.; Werner, T.

1988-01-01

The author discusses superdeformed and hypothetical hyperdeformed nuclei. Quadrupole deformations characteristic of these types of nuclei are defined. Symmetry features are also discussed. The characteristic cycle dependence of shell structures as functions of the deformation gives rise to chains of the deformed shell closures. Such a chain structure applies to moderately-, super- and hyper-deformed nuclei as well. The resulting total energy calculations give a systematic variation of super- and hyperdeformations with, e.g., increasing N at fixed Z, thus predicting the way nuclei deviate from the simple a:b = 2:1 and a:b = 3:1 symmetries

On quantization of the SU(2) Skyrmions

International Nuclear Information System (INIS)

Jurčiukonis, D.; Norvaišas, E.

2013-01-01

There are two known approaches for quantizing the SU(2) Skyrme model, the semiclassical and canonical quantization. The semiclassical approach does not take into account the non-commutativity of velocity of quantum coordinates and the stability of the semiclassical soliton is conveniently ensured by the symmetry breaking term. The canonical quantum approach leads to quantum mass correction that is not obtained in the semiclassical approach. In this Letter we argue that these two approaches are not equivalent and lead to different results. We show that the resulting profile functions have the same asymptotic behaviour, however their shape in the region close to the origin is different

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 ...

Scattering lengths in SU(2) gauge theory with two fundamental fermions

DEFF Research Database (Denmark)

Arthur, R.; Drach, V.; Hansen, Martin Rasmus Lundquist

2014-01-01

We investigate non perturbatively scattering properties of Goldstone Bosons in an SU(2) gauge theory with two Wilson fermions in the fundamental representation. Such a theory can be used to build extensions of the Standard Model that unifies Technicolor and pseudo Goldstone composite Higgs models...... the expected chiral symmetry breaking pattern. We then discuss how to compute them on the lattice and give preliminary results using finite size methods....

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

Fermion mass hierarchy as a consequence of the spontaneous breakdown of the four-flavor symmetry

International Nuclear Information System (INIS)

Cveti, M.

1985-01-01

We study the fermion mass matrix in the case of four fermionic flavors u, d, c, and s. The original Lagrangian of the effective gauge theory respects the full four-flavor symmetry and fermions are massless. We analyze a vacuum expectation pattern of the elementary Higgs-field multiplet Phi/sub a/b [(a,b) = u,d,c,s]. Nonzero vacuum expectation values of Phi spontaneously break the original flavor symmetry with fermionic masses being directly proportional to these vacuum expectation values. In the Higgs potential, hard terms in Phi respect the global symmetry SU(4)/sub L/ x SU(4)/sub R/ of four flavors while soft terms in Psi break this symmetry down to the effective anomaly-free gauge group SU(2)/sub L//sup e/+μ x SU(2)/sub R//sup e/+μ. These soft terms are due to radiative as well as nonperturbative effects. Such a symmetry structure of the Higgs potential can be motivated by the underlying preonic dynamics. The desired solution, i.e., the proper interfamily and intrafamily hierarchy as well as the desired Cabibbo mixing angle, can emerge as a consequence of a subtle interplay between the soft terms and certain hard terms of the Higgs potential

The symmetry of man.

Science.gov (United States)

Ermolenko, Alexander E; Perepada, Elena A

2007-01-01

The paper contains a description of basic regularities in the manifestation of symmetry of human structural organization and its ontogenetic and phylogenetic development. A concept of macrobiocrystalloid with inherent complex symmetry is proposed for the description of the human organism in its integrity. The symmetry can be characterized as two-plane radial (quadrilateral), where the planar symmetry is predominant while the layout of organs of radial symmetry is subordinated to it. Out of the two planes of symmetry (sagittal and horizontal), the sagittal plane is predominant. The symmetry of the chromosome, of the embrio at the early stages of cell cleavage as well as of some organs and systems in their phylogenetic development is described. An hypothesis is postulated that the two-plane symmetry is formed by two mechanisms: a) the impact of morphogenetic fields of the whole crystalloid organism during embriogenesis and, b) genetic mechanisms of the development of chromosomes having two-plane symmetry.

Superdeformations and fermion dynamical symmetries

International Nuclear Information System (INIS)

Wu, Cheng-Li

1990-01-01

In this talk, I will present a link between nuclear collective motions and their underlying fermion dynamical symmetries. In particular, I will focus on the microscopic understanding of deformations. It is shown that the SU 3 of the one major shell fermion dynamical symmetry model (FDSM) is responsible for the physics of low and high spins in normal deformation. For the recently observed phenomena of superdeformation, the physics of the problem dictates a generalization to a supershell structure (SFDSM), which also has an SU 3 fermion dynamical symmetry. Many recently discovered feature of superdeformation are found to be inherent in such an SU 3 symmetry. In both cases the dynamical Pauli effect plays a vital role. A particularly noteworthy discovery from this model is that the superdeformed ground band is not the usual unaligned band but the D-pair aligned (DPA) band, which sharply crosses the excited bands. The existence of such DPA band is a key point to understand many properties of superdeformation. Our studies also poses new experimental challenge. This is particularly interesting since there are now plans to build new and exciting γ-ray detecting systems, like the GAMMASPHERE, which could provide answers to some of these challenges. 34 refs., 11 figs., 5 tabs

Instantons and chiral symmetry breaking

International Nuclear Information System (INIS)

Carneiro, C.E.I.; McDougall, N.A.

1984-01-01

A detailed investigation of chiral symmetry breaking due to instanton dynamics is carried out, within the framework of the dilute gas approximation, for quarks in both the fundamental and adjoint representations of SU(2). The momentum dependence of the dynamical mass is found to be very similar in each representation. (orig.)

Instantons and chiral symmetry breaking

Energy Technology Data Exchange (ETDEWEB)

Carneiro, C.E.I.; McDougall, N.A. (Oxford Univ. (UK). Dept. of Theoretical Physics)

1984-10-22

A detailed investigation of chiral symmetry breaking due to instanton dynamics is carried out, within the framework of the dilute gas approximation, for quarks in both the fundamental and adjoint representations of SU(2). The momentum dependence of the dynamical mass is found to be very similar in each representation.

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.)

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.

A test of Wigner's spin-isospin symmetry from double binding energy differences

International Nuclear Information System (INIS)

Van Isacker, P.; Warner, D.D.; Brenner, D.S.

1996-01-01

The spin-isospin or SU(4) symmetry is investigated. It is shown that the N = Z enhancements of |δV np | are an unavoidable consequence of Wigner's SU(4) symmetry and that the degree of the enhancement provides a sensitive test of the quality of the symmetry itself. (K.A.)

Hidden Symmetries of Stochastic Models

Directory of Open Access Journals (Sweden)

Boyka Aneva

2007-05-01

Full Text Available In the matrix product states approach to $n$ species diffusion processes the stationary probability distribution is expressed as a matrix product state with respect to a quadratic algebra determined by the dynamics of the process. The quadratic algebra defines a noncommutative space with a $SU_q(n$ quantum group action as its symmetry. Boundary processes amount to the appearance of parameter dependent linear terms in the algebraic relations and lead to a reduction of the $SU_q(n$ symmetry. We argue that the boundary operators of the asymmetric simple exclusion process generate a tridiagonal algebra whose irriducible representations are expressed in terms of the Askey-Wilson polynomials. The Askey-Wilson algebra arises as a symmetry of the boundary problem and allows to solve the model exactly.

Stable monopole-antimonopole string background in SU(2) QCD

International Nuclear Information System (INIS)

Cho, Y.M.; Pak, D.G.

2006-01-01

Motivated by the instability of the Savvidy-Nielsen-Olesen (SNO) vacuum we make a systematic search for a stable magnetic background in pure SU(2) QCD. It is shown that a pair of axially symmetric monopole and antimonopole strings is stable, provided that the distance between the two strings is less than a critical value. The existence of a stable monopole-antimonopole string background strongly supports that a magnetic condensation of monopole-antimonopole pairs can generate a dynamical symmetry breaking, and thus the magnetic confinement of color in QCD

Noncommutative gauge theory and symmetry breaking in matrix models

International Nuclear Information System (INIS)

Grosse, Harald; Steinacker, Harold; Lizzi, Fedele

2010-01-01

We show how the fields and particles of the standard model can be naturally realized in noncommutative gauge theory. Starting with a Yang-Mills matrix model in more than four dimensions, an SU(n) gauge theory on a Moyal-Weyl space arises with all matter and fields in the adjoint of the gauge group. We show how this gauge symmetry can be broken spontaneously down to SU(3) c xSU(2) L xU(1) Q [resp. SU(3) c xU(1) Q ], which couples appropriately to all fields in the standard model. An additional U(1) B gauge group arises which is anomalous at low energies, while the trace-U(1) sector is understood in terms of emergent gravity. A number of additional fields arise, which we assume to be massive, in a pattern that is reminiscent of supersymmetry. The symmetry breaking might arise via spontaneously generated fuzzy spheres, in which case the mechanism is similar to brane constructions in string theory.

Symmetry and binding in visuo-spatial working memory.

Science.gov (United States)

Rossi-Arnaud, C; Pieroni, L; Baddeley, A

2006-04-28

Three experiments study the impact of symmetry on a sequential block tapping immediate memory task in human subjects. Experiment 1 shows an advantage from vertical symmetry over non-symmetrical sequences, while finding no effect of horizontal or diagonal symmetry. Experiment 2 tests the possible role of verbal labeling by means of a secondary task that prevents this by articulatory suppression. No evidence of verbalization was observed. A third study examines the effects of a concurrent executive load, finding an overall impairment, that did not differ between symmetrical and asymmetric patterns, suggesting that the effect of symmetry reflects automatic rather than executive processes. Implications for the episodic buffer component of working memory are discussed.

Symmetry of priapulids (Priapulida). 2. Symmetry of larvae.

Science.gov (United States)

Adrianov, A V; Malakhov, V V

2001-02-01

Larvae of priapulids are characterized by radial symmetry evident from both external and internal characters of the introvert and lorica. The bilaterality appears as a result of a combination of several radial symmetries: pentaradial symmetry of the teeth, octaradial symmetry of the primary scalids, 25-radial symmetry of scalids, biradial symmetry of the neck, and biradial and decaradial symmetry of the trunk. Internal radiality is exhibited by musculature and the circumpharyngeal nerve ring. Internal bilaterality is evident from the position of the ventral nerve cord and excretory elements. Externally, the bilaterality is determined by the position of the anal tubulus and two shortened midventral rows of scalids bordering the ventral nerve cord. The lorical elements define the biradial symmetry that is missing in adult priapulids. The radial symmetry of larvae is a secondary appearance considered an evolutionary adaptation to a lifestyle within the three-dimensional environment of the benthic sediment. Copyright 2001 Wiley-Liss, Inc.

El horizonte gráfico Centelles y su posición en la secuencia del Arte Levantino del Maestrazgo

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Valentín VILLAVERDE BONILLA

2009-12-01

Full Text Available RESUMEN: El objetivo central del trabajo es la descripción y valoración de las figuras masculinas y femeninas del horizonte Centelles, prestando una especial atención al tipo de escenas en las que se integran y a su relación con las figuras animales. El Abric de Centelles constituye un foco preferencial de atención, especialmente a la hora de definir la variabilidad formal y compositiva del horizonte. Igualmente, se valoran los elementos que permiten su situación en la secuencia gráfica del núcleo de la Valltorta-Gasulla y se establecen relaciones con otros conjuntos similares del Maestrazgo. Finalmente, se discute la cronología de este horizonte gráfico, considerando una perspectiva territorial.ABSTRACT: The main goal of this paper is the description and appraisal of female and male depictions of the Centelles stylistic horizon, paying special attention to those scenes in which they are integrated and also in their scenic relation with animal depictions. The Centelles rock art shelter is a main focus of attention, especially for defining the formal and compositional variability of this stylistic horizon. In this sense, the elements that allow its situation in the graphic sequence of Valltorta-Gassulla Valley are valued, while stylistic parallels with similar rock art shelters of Maestrazgo area are established. Finally, we discuss the chronology of Centelles stylistic horizon considering a territorial perspective.

Symmetry-adapted Liouville space. Pt. 7

International Nuclear Information System (INIS)

Temme, F.P.

1990-01-01

In examining nuclear spin dynamics of NMR spin clusters in density operator/generalized torque formalisms over vertical strokekqv>> operator bases of Liouville space, it is necessary to consider the symmetry mappings and carrier spaces under a specialized group for such (k i = 1) nuclear spin clusters. The SU2 X S n group provides the essential mappings and the form of H carrier space, which allows one to: (a) draw comparisons with Hilbert space duality, and (b) outline the form of the Coleman-Kotani genealogical hierarchy under induced S n -symmetry. (orig.)

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

Towards mirror symmetry a la SYZ for generalized Calabi-Yau manifolds

Energy Technology Data Exchange (ETDEWEB)

Grange, P. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik]|[Hamburg Univ. (Germany). Zentrum fuer Mathematische Physik; Schaefer-Nameki, S. [California Inst. of Tech., Pasadena, CA (United States)

2007-10-15

Fibrations of flux backgrounds by supersymmetric cycles are investigated. For an internal sixmanifold M with static SU(2) structure and mirror M, it is argued that the product M x M is doubly fibered by supersymmetric three-tori, with both sets of fibers transverse to M and M. The mirror map is then realized by T-dualizing the fibers. Mirror-symmetric properties of the fluxes, both geometric and non-geometric, are shown to agree with previous conjectures based on the requirement of mirror symmetry for Killing prepotentials. The fibers are conjectured to be destabilized by fluxes on generic SU(3) x SU(3) backgrounds, though they may survive at type-jumping points. T-dualizing the surviving fibers ensures the exchange of pure spinors under mirror symmetry. (orig.)

Partial restoration of spin-isospin SU(4) symmetry and the one-quasiparticle random-phase approximation method in double-β decay

Science.gov (United States)

Ferreira, V. dos S.; Krmpotić, F.; Barbero, C. A.; Samana, A. R.

2017-10-01

The one-quasiparticle random-phase approximation (one-QRPA) method is used to describe simultaneously both double-β -decay modes, giving special attention to the partial restoration of spin-isospin SU(4 ) symmetry. To implement this restoration and to fix the model parameters, we resort to the energetics of Gamow-Teller resonances and to the minima of the single-β+-decay strengths. This makes the theory predictive regarding the β β2 ν decay, producing the 2 ν moments in 48Ca, 76Ge, 82Se, 96Zr, 100Mo, Te,130128, and 150Nd, that are of the same order of magnitude as the experimental ones; however, the agreement with β β2 ν data is only modest. To include contributions coming from induced nuclear weak currents, we extend the β β0 ν -decay formalism employed previously in C. Barbero et al., Nucl. Phys. A 628, 170 (1998), 10.1016/S0375-9474(97)00614-3, which is based on the Fourier-Bessel expansion. The numerical results for the β β0 ν moments in the above mentioned nuclei are similar to those obtained in other theoretical studies although smaller on average by ˜40 % . We attribute this difference basically to the one-QRPA method, employed here for the first time, instead of the currently used two-QRPA method. The difference is partially due also to the way of carrying out the restoration of the spin-isospin symmetry. It is hard to say which is the best way to make this restoration, since the β β0 ν moments are not experimentally measurable. The recipe proposed here is based on physically robust arguments. The numerical uncertainties in the β β moments, related to (i) their strong dependence on the residual interaction in the particle-particle channel when evaluated within the QRPA, and (ii) lack of proper knowledge of single-particle energies, have been quantified. It is concluded that the partial restoration of the SU(4 ) symmetry, generated by the residual interaction, is crucial in the description of the β β decays, regardless of the nuclear

Using Noether symmetries to specify f(R) gravity

International Nuclear Information System (INIS)

Paliathanasis, Andronikos

2013-01-01

A detailed study of the modified gravity, f(R) models is performed, using the fact that the Noether point symmetries of these models are geometric symmetries of the mini su-perspace of the theory. It is shown that the requirement that the field equations admit Noether point symmetries selects definite models in a self-consistent way. As an application in Cosmology we consider the Friedman -Robertson-Walker spacetime and show that the only cosmological model which is integrable via Noether point symmetries is the (R b − 2Λ) c model, which generalizes the Lambda Cosmology. Furthermore using the corresponding Noether integrals we compute the analytic form of the main cosmological functions

Quark mass matrices in left-right symmetric gauge theories

International Nuclear Information System (INIS)

Ecker, G.; Grimus, W.; Konetschny, W.

1981-01-01

The most general left-right symmetry for SU(2)sub(L) x SU(2)sub(R) x U(1) gauge theories with any number of flavours and with at most two scalar multiplets transforming as anti qq bilinears is analyzed. In order to get additional constraints on the structure of quark mass matrices all possible horizontal groups (continuous or discrete) are investigated. A complete classification of physically inequivalent quark mass matrices is given for four and six flavours. It is argued that the methods and results are also applicable in the case of dynamical symmetry breaking. Parity invariance and horizontal symmetry are shown to imply CP conservation on the Lagrangian level. For all non-trivial three-generation models there is spontaneous CP violation which in most cases turns out to be naturally small. (Auth.)

Deconfined Quantum Critical Points: Symmetries and Dualities

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Chong Wang

2017-09-01

Full Text Available The deconfined quantum critical point (QCP, separating the Néel and valence bond solid phases in a 2D antiferromagnet, was proposed as an example of (2+1D criticality fundamentally different from standard Landau-Ginzburg-Wilson-Fisher criticality. In this work, we present multiple equivalent descriptions of deconfined QCPs, and use these to address the possibility of enlarged emergent symmetries in the low-energy limit. The easy-plane deconfined QCP, besides its previously discussed self-duality, is dual to N_{f}=2 fermionic quantum electrodynamics, which has its own self-duality and hence may have an O(4×Z_{2}^{T} symmetry. We propose several dualities for the deconfined QCP with SU(2 spin symmetry which together make natural the emergence of a previously suggested SO(5 symmetry rotating the Néel and valence bond solid orders. These emergent symmetries are implemented anomalously. The associated infrared theories can also be viewed as surface descriptions of (3+1D topological paramagnets, giving further insight into the dualities. We describe a number of numerical tests of these dualities. We also discuss the possibility of “pseudocritical” behavior for deconfined critical points, and the meaning of the dualities and emergent symmetries in such a scenario.

Discrete symmetries and their stringy origin

International Nuclear Information System (INIS)

Mayorga Pena, Damian Kaloni

2014-05-01

Discrete symmetries have proven to be very useful in controlling the phenomenology of theories beyond the standard model. In this work we explore how these symmetries emerge from string compactifications. Our approach is twofold: On the one hand, we consider the heterotic string on orbifold backgrounds. In this case the discrete symmetries can be derived from the orbifold conformal field theory, and it can be shown that they are in close relation with the orbifold geometry. We devote special attention to R-symmetries, which arise from discrete remnants of the Lorentz group in compact space. Further we discuss the physical implications of these symmetries both in the heterotic mini-landscape and in newly constructed models based on the Z 2 x Z 4 orbifold. In both cases we observe that the discrete symmetries favor particular locations in the orbifold where the particles of standard model should live. On the other hand we consider a class of F-theory models exhibiting an SU(5) gauge group, times additional U(1) symmetries. In this case, the smooth compactification background does not permit us to track the discrete symmetries as transparently as in orbifold models. Hence, we follow a different approach and search for discrete subgroups emerging after the U(1)s are broken. We observe that in this approach it is possible to obtain the standard Z 2 matter parity of the MSSM.

Boson-fermion symmetries in the W-Pt region

International Nuclear Information System (INIS)

Warner, D.D.

1985-01-01

The concept of symmetry in the Interacting Boson Model (IBM) description of even-even nuclei has proved to be one of the model's most important elements, because they provide benchmarks in the formulation of a unified description of a broad range of nuclei. The importance of the recently proposed symmetries in odd-even systems can thus be viewed in the same light, and their role in pointing to a simple prescription for the changing collective structure in odd A nuclei throughout a major shell is likely to prove even more essential, given the much greater complexity of the boson-fermion (IBFM) Hamiltonian. The group structure of a boson-fermion system is described by U/sup B/(6) x U/sup F/(m) where m specifies the number of states available to the odd fermion, and thus depends on the single particle space assumed. The ability to construct group chains corresponding to the symmetries SU(5), SU(3) or 0(6) depends on the value of m. Of the structures studied in detail to date, the case of m = 12 is the one with the broadest potential. The fermion is allowed to occupy orbits with j = 1/2, 3/2 and 5/2, so that the assumed single particle space corresponds to the negative parity states available to an odd neutron at the end of the N = 82-126 shell, namely, P/sub 1/2/, p/sub 3/2/ and f/sub 5/2/. The region of interest thus spans the W-Pt nuclei, and since one prerequisite for an odd-A symmetry is the existence of that same symmetry in the neighboring even-even core nucleus, the odd Pt nuclei around A = 196 offer the obvious testing ground for the 0(6) limit of U(6/12). The heavier even-even W nuclei, on the other hand, have the characteristics of an axial rotor, and hence the negative parity structure of the neighboring odd W isotopes offers the possibility to study the validity of the SU(3) limit. Given a definition and understanding of these two limits, the construction of a simple description of the transitional Os nuclei can be considered

Effects of renormalizing the chiral SU(2) quark-meson model

Science.gov (United States)

Zacchi, Andreas; Schaffner-Bielich, Jürgen

2018-04-01

We investigate the restoration of chiral symmetry at finite temperature in the SU(2) quark-meson model, where the mean field approximation is compared to the renormalized version for quarks and mesons. In a combined approach at finite temperature, all the renormalized versions show a crossover transition. The inclusion of different renormalization scales leave the order parameter and the mass spectra nearly untouched but strongly influence the thermodynamics at low temperatures and around the phase transition. We find unphysical results for the renormalized version of mesons and the combined one.

Dynamical symmetries of the Klein-Gordon equation

International Nuclear Information System (INIS)

Zhang Fulin; Chen Jingling

2009-01-01

The dynamical symmetries of the two-dimensional Klein-Gordon equations with equal scalar and vector potentials (ESVPs) are studied. The dynamical symmetries are considered in the plane and the sphere, respectively. The generators of the SO(3) group corresponding to the Coulomb potential and the SU(2) group corresponding to the harmonic oscillator potential are derived. Moreover, the generators in the sphere construct the Higgs algebra. With the help of the Casimir operators, the energy levels of the Klein-Gordon systems are yielded naturally

Intersecting Branes Flip SU(5)

CERN Document Server

Ellis, Jonathan Richard; Nanopoulos, Dimitri V; Ellis, John

2002-01-01

Within a toroidal orbifold framework, we exhibit intersecting brane-world constructions of flipped SU(5) \\times U(1) GUT models with various numbers of generations, other chiral matter representations and Higgs representations. We exhibit orientifold constructions with integer winding numbers that yield 8 or more conventional SU(5) generations, and orbifold constructions with fractional winding numbers that yield flipped SU(5) \\times U(1) models with just 3 conventional generations. Some of these models have candidates for the 5 and {\\bar 5} Higgs representations needed for electroweak symmetry breaking, but not for the 10 and {\\bar 10} representations needed for GUT symmetry breaking, or vice-versa.

Chiral symmetry breaking parameters from QCD sum rules

Energy Technology Data Exchange (ETDEWEB)

Mallik, S [Karlsruhe Univ. (T.H.) (Germany, F.R.). Inst. fuer Theoretische Kernphysik; Bern Univ. (Switzerland). Inst. fuer Theoretische Physik)

1982-10-04

We obtain new QCD sum rules by considering vacuum expectation values of two-point functions, taking all the five quark bilinears into account. These sum rules are employed to extract values of different chiral symmetry breaking parameters in QCD theory. We find masses of light quarks, m=1/2msub(u)+msub(d)=8.4+-1.2 MeV, msub(s)=205+-65 MeV. Further, we obtain corrections to certain soft pion (kaon) PCAC relations and the violation of SU(3) flavour symmetry by the non-strange and strange quark-antiquark vacuum condensate.

Baryon number generation in a flipped SU(5) x U(1) model

International Nuclear Information System (INIS)

Campbell, B.; Hagelin, J.; Nanopoulos, D.V.; Olive, K.A.

1988-01-01

We consider the possibilities for generating a baryon asymmetry in the early universe in a flipped SU(5) x U(1) model inspired by the superstring. Depending on the temperature of the radiation background after inflation we can distinguish between two scenarios for baryogenesis: (1) After reheating the original SU(5) x U(1) symmetry is restored, or there was no inflation at all; (2) reheating after inflation is rather weak and SU(5) x U(1) is broken. In either case the asymmetry is generated by the out-of-equilibrium decays of a massive SU(3) x SU(2) x U(1) singlet field φ m . In the flipped SU(5) x U(1) model, gauge symmetry breaking is triggered by strong coupling phenomena, and is in general accompanied by the production of entropy. We examine constraints on the reheating temperature and the strong coupling scale in each of the scenarios. (orig.)

Alternative [SU(3]4 model of leptonic color and dark matter

Directory of Open Access Journals (Sweden)

Corey Kownacki

2018-03-01

Full Text Available The alternative [SU(3]4 model of leptonic color and dark matter is discussed. It unifies at MU∼1014 GeV and has the low-energy subgroup SU(3q×SU(2l×SU(2L×SU(2R×U(1X with (u,hR instead of (u,dR as doublets under SU(2R. It has the built-in global U(1 dark symmetry which is generalized B–L. In analogy to SU(3q quark triplets, it has SU(2l hemion doublets which have half-integral charges and are confined by SU(2l gauge bosons (stickons. In analogy to quarkonia, their vector bound states (hemionia are uniquely suited for exploration at a future e−e+ collider.

Alternative [SU(3)]4 model of leptonic color and dark matter

Science.gov (United States)

Kownacki, Corey; Ma, Ernest; Pollard, Nicholas; Popov, Oleg; Zakeri, Mohammadreza

2018-03-01

The alternative [ SU (3) ] 4 model of leptonic color and dark matter is discussed. It unifies at MU ∼1014 GeV and has the low-energy subgroup SU(3)q × SU(2)l × SU(2)L × SU(2)R × U(1)X with (u , h) R instead of (u , d) R as doublets under SU(2)R. It has the built-in global U (1) dark symmetry which is generalized B- L. In analogy to SU(3)q quark triplets, it has SU(2)l hemion doublets which have half-integral charges and are confined by SU(2)l gauge bosons (stickons). In analogy to quarkonia, their vector bound states (hemionia) are uniquely suited for exploration at a future e-e+ collider.

Near-horizon symmetries of extremal black holes

International Nuclear Information System (INIS)

Kunduri, Hari K; Lucietti, James; Reall, Harvey S

2007-01-01

Recent work has demonstrated an attractor mechanism for extremal rotating black holes subject to the assumption of a near-horizon SO(2, 1) symmetry. We prove the existence of this symmetry for any extremal black hole with the same number of rotational symmetries as known four- and five-dimensional solutions (including black rings). The result is valid for a general two-derivative theory of gravity coupled to Abelian vectors and uncharged scalars, allowing for a non-trivial scalar potential. We prove that it remains valid in the presence of higher-derivative corrections. We show that SO(2, 1)-symmetric near-horizon solutions can be analytically continued to give SU(2)-symmetric black hole solutions. For example, the near-horizon limit of an extremal 5D Myers-Perry black hole is related by analytic continuation to a non-extremal cohomogeneity-1 Myers-Perry solution

Comparison of IBM-2 calculations with X(5) critical point symmetry for low lying states in 128-140Nd

International Nuclear Information System (INIS)

Uluer, I.; Olgun, D.; Inan, S.; Tuerkan, N.

2006-01-01

The X(5) would take place when moving continuously from the pure U(5) symmetry to the SU(3) symmetry and it implies a definite relations among the level energies and among the E2 transition strengths. It was recently shown that a signature of phase transition is observed in the chain of Sm, Mo and Nd isotopes, where 1 52Sm, 1 04Mo and 1 50Nd display the predicted features of the X(5) symmetry and mark therefore the critical point. However, more detailed studies and experiments are needed to get ideas about this signature. Without entering into detail we have firstly compared the results obtained in our previous study of 1 28- 1 40Nd with that of the limits in X(5) symmetry and then given a clear description about the validity of the Hamiltonian parameters used in the study. At the end, we have concluded that some of Nd isotopes display X(5) symmetry features

Flavour from accidental symmetries

International Nuclear Information System (INIS)

Ferretti, Luca; King, Stephen F.; Romanino, Andrea

2006-01-01

We consider a new approach to fermion masses and mixings in which no special 'horizontal' dynamics is invoked to account for the hierarchical pattern of charged fermion masses and for the peculiar features of neutrino masses. The hierarchy follows from the vertical, family-independent structure of the model, in particular from the breaking pattern of the Pati-Salam group. The lightness of the first two fermion families can be related to two family symmetries emerging in this context as accidental symmetries

Reformulation od spontaneous symmetry breaking and the Weinberg-Salam model

International Nuclear Information System (INIS)

Rawat, A.S.; Rawat, S.; Negi, O.P.S.

1999-01-01

Spontaneous symmetry breaking and the Weinberg-Salam model have been reformulated in terms of quaternion-valued field variables. The quaternion-valued scalar Lagrangian reduces to four different field equations associated with the scalar quartet of a quaternion field φ φ 0 +e 1φ1 +e 2φ2 +e 3φ3 . It has been shown that the quaternion gauge group SO(4) is spontaneously broken to two gauge groups of SU(2) non Abelian gauge fields. The Weinberg-Salam model of electroweak interaction has been extensively studied to enlarge the gauge group structure SU(2) L xSU(2) R xU(1)

Neutrino masses in an SO(10) model with an intermediate stage of symmetry breaking

International Nuclear Information System (INIS)

Svetovoi, V.B.

1982-01-01

The effect on neutrino masses of an intermediate stage in symmetry breaking different from SU(5) is investigated in detail for the SO(10) model. There are two possibilities depending on the contents of the Higgs sector: i) m/sub ν/approx.m/sub f/(M/sub W//M 1 ); ii) m/sub ν/approx.m/sub f/(M/sub W//M 1 )(M/M 1 ), where M, M 1 and M/sub W/ are the scales of the breaking of the original SO(10) symmetry, the intermediate symmetry, and the standard SU/sub c/(3) x SU/sub L/(2) x U(1) symmetry, respectively, and m/sub f/ is a typical fermion mass. It is shown that a Majorana mass of the right-handed-neutrino (ν/sub R/) of a purely loop origin would result in too large a mass of the usual neutrinos, so a tree-graph contribution to the mass of ν/sub R/ is necessary. Numerical estimates for the neutrino masses are discussed

Supersonic Love waves in strong piezoelectrics of symmetry mm2

International Nuclear Information System (INIS)

Darinskii, A. N.; Weihnacht, M.

2001-01-01

A study has been made of the Love wave propagation on piezoelectric substrates of symmetry mm2. It has been shown that under certain conditions the velocity of the Love wave exceeds that of shear horizontal (SH) bulk waves in the substrate. This occurs when the slowness curve of SH bulk waves in the substrate either has a concavity or is convex with nearly zero curvature. For such 'supersonic' Love waves to appear, it is also required that the substrate as well as the layer be specially oriented and that their material constants fulfill a number of inequalities. Numerical computations have been carried out for a number of structures. The results of numerical computations have been compared with approximate analytical estimations. [copyright] 2001 American Institute of Physics

A test of Wigner's spin-isospin symmetry from double binding energy differences

International Nuclear Information System (INIS)

Van Isacker, P.; Warner, D.D.; Brenner, D.S.

1995-01-01

It is shown that the anomalously large double binding energy differences for even-even N = Z nuclei are a consequence of Wigner's SU(4) symmetry. These, and similar quantities for odd-mass and odd-odd nuclei, provide a simple and distinct signature of this symmetry in N ≅ Z nuclei. (authors). 16 refs., 2 figs., 1 tab

Peripheral Contour Grouping and Saccade Targeting: The Role of Mirror Symmetry

Directory of Open Access Journals (Sweden)

Michaël Sassi

2014-01-01

Full Text Available Integrating shape contours in the visual periphery is vital to our ability to locate objects and thus make targeted saccadic eye movements to efficiently explore our surroundings. We tested whether global shape symmetry facilitates peripheral contour integration and saccade targeting in three experiments, in which observers responded to a successful peripheral contour detection by making a saccade towards the target shape. The target contours were horizontally (Experiment 1 or vertically (Experiments 2 and 3 mirror symmetric. Observers responded by making a horizontal (Experiments 1 and 2 or vertical (Experiment 3 eye movement. Based on an analysis of the saccadic latency and accuracy, we conclude that the figure-ground cue of global mirror symmetry in the periphery has little effect on contour integration or on the speed and precision with which saccades are targeted towards objects. The role of mirror symmetry may be more apparent under natural viewing conditions with multiple objects competing for attention, where symmetric regions in the visual field can pre-attentively signal the presence of objects, and thus attract eye movements.

Threshold corrections and gauge symmetry in twisted superstring models

International Nuclear Information System (INIS)

Pierce, D.M.

1994-01-01

Threshold corrections to the running of gauge couplings are calculated for superstring models with free complex world sheet fermions. For two N=1 SU(2)xU(1) 5 models, the threshold corrections lead to a small increase in the unification scale. Examples are given to illustrate how a given particle spectrum can be described by models with different boundary conditions on the internal fermions. We also discuss how complex twisted fermions can enhance the symmetry group of an N=4, SU(3)xU(1)xU(1) model to the gauge group SU(3)xSU(2)xU(1). It is then shown how a mixing angle analogous to the Weinberg angle depends on the boundary conditions of the internal fermions

Neutrino masses and spontaneously broken flavor symmetries

International Nuclear Information System (INIS)

Staudt, Christian

2014-01-01

We study the phenomenology of supersymmetric flavor models. We show how the predictions of models based on spontaneously broken non-Abelian discrete flavor symmetries are altered when we include so-called Kaehler corrections. Furthermore, we discuss anomaly-free discrete R symmetries which are compatible with SU(5) unification. We find a set of symmetries compatible with suppressed Dirac neutrino masses and a unique symmetry consistent with the Weinberg operator. We also study a pseudo-anomalous U(1) R symmetry which explains the fermion mass hierarchies and, when amended with additional singlet fields, ameliorates the fine-tuning problem.

Symmetry breaking of SO(10) and constraints on Higgs potential, (1)

International Nuclear Information System (INIS)

Yasue, Masaki.

1980-08-01

The symmetry breaking of SO(10) is studied in the tree approximation of the potential for an adjoint (45) representation and a spinorial (16) representation. The potential can break SO(10) down to SU(3)sub(c) x SU(2)sub(L) x U(1). It is not allowed to break SO(10) down to SU(3)sub(c) x U(1)sub(em) via SU(3)sub(c) x SU(2)sub(L) x U(1) even in the presence of a cubic (16) (16*) (45) coupling. Instead, SU(3) x U(1) comes from SU(4) x U(1). The masses for the physical Higgs scalars are calculated in SU(3)sub(c) x SU(2)sub(L) x U(1). The dynamically allowed region of the vacuum expectation values of the (45) is found to be strongly restricted. As a result, SO(6) and SO(4) cannot show up in the course of the breaking. (author)

Spin transistor action from Onsager reciprocity and SU(2) gauge theory

Energy Technology Data Exchange (ETDEWEB)

Adagideli, Inanc [Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul (Turkey); Lutsker, Vitalij; Scheid, Matthias; Richter, Klaus [Institut fuer Theoretische Physik, Universitaet Regensburg, 93040 Regensburg (Germany); Jacquod, Philippe [Physics Department, University of Arizona, Tucson, AZ (United States)

2012-07-01

We construct a local gauge transformation to show how, in confined systems, a generic, weak non-homogeneous SU(2) spin-orbit Hamiltonian reduces to two U(1) Hamiltonians for spinless fermions at opposite magnetic fields, to leading order in the spin-orbit strength. Using an Onsager relation, we further show how the resulting spin conductance vanishes in a two-terminal setup, and how it is turned on by either weakly breaking time-reversal symmetry or opening additional transport terminals. We numerically check our theory for mesoscopic cavities as well as Aharonov-Bohm rings.

New narrow boson resonances and SU(4) symmetry: Selection rules, SU(4) mixing, and mass formulas

International Nuclear Information System (INIS)

Takasugi, E.; Oneda, S.

1975-01-01

General SU(4) sum rules are obtained for bosons in the theoretical framework of asymptotic SU(4), chiral SU(4) direct-product SU(4) charge algebra, and a simple mechanism of SU(4) and chiral SU(4) direct-product SU(4) breaking. The sum rules exhibit a remarkable interplay of the masses, SU(4) mixing angles, and axial-vector matrix elements of 16-plet boson multiplets. Under a particular circumstance (i.e., in the ''ideal'' limit) this interplay produces selection rules which may explain the remarkable stability of the newly found narrow boson resonances. General SU(4) mass formulas and inter-SU(4) -multiplet mass relations are derived and SU(4) mixing parameters are completely determined. Ground state 1 -- and 0 -+ 16-plets are especially discussed and the masses of charmed and uncharmed new members of these multiplets are predicted

Spontaneously broken global symmetries and cosmology

International Nuclear Information System (INIS)

Shafi, Q.; Vilenkin, A.

1984-01-01

Phase transitions associated with spontaneously broken global symmetries, in case these occur in nature, can have important cosmological implications. This is illustrated through two examples. The first one shows how the spontaneous breaking of a global U(1) symmetry, present, for instance, in the minimal SU(5) model, can lead to an inflationary phase. The second example illustrates how topologically stable strings associated with the breaking of U(1) symmetry make an appearance at (or near) the end of the inflationary era

White dwarf axions, PAMELA data, and flipped-SU(5)

Energy Technology Data Exchange (ETDEWEB)

Bae, Kyu Jung [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Huh, Ji-Haeng [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)], E-mail: jhhuh@phya.snu.ac.kr; 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@ctp.snu.ac.kr; Kyae, Bumseok [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)], E-mail: bskyae@gmail.com; Viollier, Raoul D. [Institute of Theoretical Physics and Astrophysics, Department of Physics, University of Cape Town, Private Bag, Rondebosch 7701 (South Africa)

2009-08-11

Recently, there are two hints arising from physics beyond the standard model. One is a possible energy loss mechanism due to emission of very weakly interacting light particles from white dwarf stars, with a coupling strength {approx}0.7x10{sup -13}, and another is the high energy positrons observed by the PAMELA satellite experiment. We construct a supersymmetric flipped-SU(5) model, SU(5)xU(1){sub X} with appropriate additional symmetries, [U(1){sub H}]{sub gauge}x[U(1){sub R}xU(1){sub {gamma}}]{sub global}xZ{sub 2}, such that these are explained by a very light electrophilic axion of mass 0.5 meV from the spontaneously broken U(1){sub {gamma}} and two component cold dark matters from Z{sub 2} parity. We show that in the flipped-SU(5) there exists a basic mechanism for allowing excess positrons through the charged SU(5) singlet leptons, but not allowing antiproton excess due to the absence of the SU(5) singlet quarks. We show the discovery potential of the charged SU(5) singlet E at the LHC experiments by observing the electron and positron spectrum. With these symmetries, we also comment on the mass hierarchy between the top and bottom quarks.

Quark diquark symmetry breaking

International Nuclear Information System (INIS)

Souza, M.M. de

1980-01-01

Assuming the baryons are made of quark-diquark pairs, the wave functions for the 126 allowed ground states are written. The quark creation and annihilations operators are generalized to describe the quark-diquark structure in terms of a parameter σ. Assuming that all quark-quark interactions are mediated by gluons transforming like an octet of vector mesons, the effective Hamiltonian and the baryon masses as constraint equations for the elements of the mass matrix is written. The symmetry is the SU(6) sub(quark)x SU(21) sub(diquark) broken by quark-quark interactions respectively invariant under U(6), U(2) sub(spin), U(3) and also interactions transforming like the eighth and the third components of SU(3). In the limit of no quark-diquark structure (σ = 0), the ground state masses is titted to within 1% of the experimental data, except for the Δ(1232), where the error is almost 2%. Expanding the decuplet mass equations in terms of σ and keeping terms only up to the second order, this error is reduced to 67%. (Author) [pt

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.

On the geometry of lambda-symmetries and PDE reduction

International Nuclear Information System (INIS)

Gaeta, Giuseppe; Morando, Paola

2004-01-01

We give a geometrical characterization of λ-prolongations of vector fields, and hence of λ-symmetries of ODEs. This allows an extension to the case of PDEs and systems of PDEs; in this context the central object is a horizontal 1-form μ, and we speak of μ-prolongations of vector fields and μ-symmetries of PDEs. We show that these are as good as standard symmetries in providing symmetry reduction of PDEs and systems, and explicit invariant solutions

Flipped SU(5) times U(1) in superconformal models

Energy Technology Data Exchange (ETDEWEB)

Bailin, D.; Katechou, E.K. (Sussex Univ., Brighton (United Kingdom). School of Mathematical and Physical Sciences); Love, A. (London Univ. (United Kingdom))

1992-01-10

This paper reports that flipped SU(5) {times} U(1) models are constructed in the framework of tensoring of N = 2 superconformal minimal models quotiented by discrete symmetries. Spontaneous breaking of flipped SU(5) {times} U(1) and extra U(1) factors in the gauge group along F-flat directions of the effective potential is studied.

Symmetry fractionalization of visons in Z2 spin liquids

Science.gov (United States)

Qi, Yang; Cheng, Meng; Fang, Chen

In this work we study symmetry fractionalization of vison excitations in topological Z2 spin liquids. We show that in the presence of the full SO (3) spin-rotational symmetry and if there is an odd number of spin-1/2 per unit cell, the symmetry fractionalization of visons is completely fixed. On the other hand, visons can have different classes of symmetry fractionalization if the spin-rotational symmetry is reduced. As a concrete example, we show that visons in the Balents-Fisher-Girvin Z2 spin liquid have crystal symmetry fractionalization classes which are not allowed in SO (3) symmetric spin liquids, due to the reduced spin-rotational symmetry.

Unveiling a spinor field classification with non-Abelian gauge symmetries

Science.gov (United States)

Fabbri, Luca; da Rocha, Roldão

2018-05-01

A spinor fields classification with non-Abelian gauge symmetries is introduced, generalizing the U(1) gauge symmetries-based Lounesto's classification. Here, a more general classification, contrary to the Lounesto's one, encompasses spinor multiplets, corresponding to non-Abelian gauge fields. The particular case of SU(2) gauge symmetry, encompassing electroweak and electromagnetic conserved charges, is then implemented by a non-Abelian spinor classification, now involving 14 mixed classes of spinor doublets. A richer flagpole, dipole, and flag-dipole structure naturally descends from this general classification. The Lounesto's classification of spinors is shown to arise as a Pauli's singlet, into this more general classification.

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

International Nuclear Information System (INIS)

Pirogov, Yu.F.

1980-01-01

In the model of early chiral grand unification SU(8)sub(L)xSU(8)sub(R) with intermediate symmetry hierarchies the radiation corrections for sinsup(2)thetasub(W)(μ) and α(μ) are calculated and unification mass M 8 is found in the one loop approximation with Higgs fields contribution being neglected. It is shown that there exists a natural hierarchy, leading to the decrease of sinsup(2)thetasub(W)(Msub(W)) down to the value sinsup(2)thetasub(W)=1/5-1/4 and simultaneous decrease of M 8 down to M 8 =(10 6 -10 7 ) GeV as compared with the values when there is no hierarchy [ru

The SU(4), SU(2)xSU(2) chain

International Nuclear Information System (INIS)

Partensky, A.; Maguin, C.

1976-11-01

The main results of a work concerning the calculation of the matrices of the generators of SU(4) in a given (p,p',p'') irreducible representation, in which the states are labelled by the spin quantum numbers, S, MS, are given. Then the SU(4) algebra is defined, the labelling problem of the states is discussed and the Racah formula transformed, which facilitates the calculation. The semi-reduced matrix elements of the Q, Vsup(Q) and Wsup(Q) vectors are defined. Finally an explicit formulation of the matrix elements of Q is given, in the particular case T=p for any S, or S=p for any T; the example of the (3 2 0) irreducible representation is treated

Flipped SU(5) predicts {delta}T/T

Energy Technology Data Exchange (ETDEWEB)

Kyae, Bumseok [School of Physics, Korea Institute for Advanced Study, 207-43, Cheongnyangni-Dong, Dongdaemun-Gu, Seoul 130-722 (Korea, Republic of)]. E-mail: bkyae@kias.re.kr; Shafi, Qaisar [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)]. E-mail: shafi@bartol.udel.edu

2006-04-20

We discuss hybrid inflation in supersymmetric flipped SU(5) model such that the cosmic microwave anisotropy {delta}T/T is essentially proportional to (M/M{sub P}){sup 2}, where M denotes the symmetry breaking scale and M{sub P} (=2.4x10{sup 18} GeV) is the reduced Planck mass. The magnitude of M determined from {delta}T/T measurements can be consistent with the value inferred from the evolution of SU(3) and SU(2) gauge couplings. In other words, one could state that flipped SU(5) predicts (more precisely 'postdicts') {delta}T/T. The scalar spectral index n{sub s}=0.993+/-0.007, the scalar to tensor ratio satisfies r-bar 10{sup -6}, while dn{sub s}/dlnk-bar 4x10{sup -4}.

New symmetries for the Dirac equation

International Nuclear Information System (INIS)

Linhares, C.A.; Mignaco, J.A.

1990-06-01

We study through both the matrix and differential-form formalism the SU(4) symmetry relating spin 1/2 particles. Minimal left ideals of the Clifford algebra are shown to be irreducible representations of these particles. Their physical interpretation relies on their mutual relationship via parity, time reversal and their product. The implication of these features on the spectrum proliferation problem on the lattice is emphasized. (author)

Unconstrained SU(2) and SU(3) Yang-Mills classical mechanics

International Nuclear Information System (INIS)

Dahmen, B.; Raabe, B.

1992-01-01

A systematic study of contraints in SU(2) and SU(3) Yang-Mills classical mechanics is performed. Expect for the SU(2) case with spatial angular momenta they turn out to be nonholonomic. The complete elimination of the unphysical gauge and rotatinal degrees of freedom is achieved using Dirac's constraint formalism. We present an effective unconstrained formulation of the general SU(2) Yang-Mills classical mechanics as well as for SU(3) in the subspace of vanishing spatial angular momenta that is well suited for further explicit dynamical investigations. (orig.)

Breaking of the SU(4) limit for the Gamow-Teller strength in N{proportional_to}Z nuclei

Energy Technology Data Exchange (ETDEWEB)

Petermann, I. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); Gesellschaft fuer Schwerionenforschung Darmstadt, Darmstadt (Germany); Martinez-Pinedo, G. [Gesellschaft fuer Schwerionenforschung Darmstadt, Darmstadt (Germany); Langanke, K. [Gesellschaft fuer Schwerionenforschung Darmstadt, Darmstadt (Germany); Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); Caurier, E. [Universite Louis Pasteur, Institut de Recherches Subatomiques, Strasbourg (France)

2007-12-15

We have performed large-scale shell model calculations of the Gamow-Teller strength distributions in N{proportional_to}Z pf-shell nuclei. These calculations were motivated by the experimental attempts to measure the low-lying GT strength for the even-even N=Z+2 or N=Z-2 nuclei {sup 46}Ti, {sup 50}Cr, {sup 54}Fe and {sup 62}Ge, where a sizable low-energy GT strength could be interpreted as reminiscence of SU(4) symmetry; in the limit of exact SU(4) symmetry the GT{sub -} strength would be concentrated in a single transition to the lowest T=0, J=1{sup +} state in the daughter. We confirm that the SU(4) symmetry is strongly broken by the spin-orbit interaction and by increasing neutron excess. (orig.)

Dynamical symmetries of two-dimensional systems in relativistic quantum mechanics

International Nuclear Information System (INIS)

Zhang Fulin; Song Ci; Chen Jingling

2009-01-01

The two-dimensional Dirac Hamiltonian with equal scalar and vector potentials has been proved commuting with the deformed orbital angular momentum L. When the potential takes the Coulomb form, the system has an SO(3) symmetry, and similarly the harmonic oscillator potential possesses an SU(2) symmetry. The generators of the symmetric groups are derived for these two systems separately. The corresponding energy spectra are yielded naturally from the Casimir operators. Their non-relativistic limits are also discussed

Two-plane symmetry in the structural organization of man.

Science.gov (United States)

Ermolenko, A E

2005-01-01

Manifestations of symmetry in the human structural organization in ontogenesis and phylogenetic development are analysed. A concept of macrobiocrystalloid with inherent complex symmetry is proposed for the description of the human organism in its integrity. The symmetry can be characterized as two-plane radial (quadrilateral), where the planar symmetry is predominant while the layout of organs of radial symmetry is subordinated to it. Out of the two planes of symmetry (sagittal and horizontal), the sagittal plane is predominant: (a) the location of the organs is governed by two principles: in compliance with the symmetry planes and in compliance with the radial symmetry around cavities; (b) the location of the radial symmetry organs is also governed by the principle of two-plane symmetry; (c) out of the four antimeres of two-plane symmetry, two are paired while the other two have merged into one organ; (d) some organs which are antimeres relative to the horizontal plane are located at the cranial end of the organism (sensory organs, cerebrum-cerebellum, heart-spleen and others). The two-plane symmetry is formed by two mechanisms--(a) the impact of morphogenetic fields of the whole crystalloid organism during embriogenesis and (b) genetic mechanisms of the development of chromosomes having two-plane symmetry. When comparing mineral and biological entities we should consider not the whole immobile crystal but only the active superficial part of a growing or dissolving crystal, the interface between the crystal surface and the crystal-forming environment which directly controls crystal growth and adapts itself to it, as well as crystal feed stock expressed in the structure of concentration flows. The symmetry of the chromosome, of the embrion at the early stages of cell cleavage as well as of some organs and systems in their phylogenetic development is described.

CKM and PMNS mixing matrices from discrete subgroups of SU(2)

International Nuclear Information System (INIS)

Potter, Franklin

2015-01-01

Remaining within the realm of the Standard Model(SM) local gauge group, this first principles derivation of both the PMNS and CKM matrices utilizes quaternion generators of the three discrete (i.e., finite) binary rotational subgroups of SU(2) called [3,3,2], [4,3,2], and [5,3,2] for three lepton families in R 3 and four related discrete binary rotational subgroups [3,3,3], [4,3,3], [3,4,3], and [5,3,3] represented by four quark families in R 4 . The traditional 3x3 CKM matrix is extracted as a submatrix of the 4x4 CKM4 matrix. If these two additional quarks b' and t' of a 4th quark family exist, there is the possibility that the SM lagrangian may apply all the way down to the Planck scale. There are then numerous other important consequences. The Weinberg angle is derived using these same quaternion generators, and the triangle anomaly cancellation is satisfied even though there is an obvious mismatch of three lepton families to four quark families. In a discrete space, one can also use these generators to derive a unique connection from the electroweak local gauge group SU(2) L x U(1) Y acting in R 4 to the discrete group Weyl E 8 in R 8 . By considering Lorentz transformations in discrete (3,1)-D spacetime, one obtains another Weyl E 8 discrete symmetry group in R 8 , so that the combined symmetry is Weyl E 8 x Weyl E 8 = 'discrete' SO(9,1) in 10-D spacetime. This unique connection is in direct contrast to the 10 500 possible connections for superstring theory! (paper)

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.

Unconstrained SU(2) and SU(3) Yang-Mills clasical mechanics

International Nuclear Information System (INIS)

Dahmen, B.; Raabe, B.

1992-01-01

A systematic study of constraints in SU(2) and SU(3) Yang-Mills classical mechanics is performed. Expect for the SU(2) case with vanishing spatial angular momenta they turn out to be non-holonomic. Using Dirac's constraint formalism we achieve a complete elimination of the unphysical gauge and rotational degrees of freedom. This leads to an effective unconstrained formulation both for the full SU(2) Yang-Mills classical mechanics and for the SU(3) case in the subspace of vanishing spatial angular momenta. We believe that our results are well suited for further explicit dynamical investigations. (orig.)

Enhanced gauge symmetry and winding modes in double field theory

Energy Technology Data Exchange (ETDEWEB)

Aldazabal, G. [Centro Atómico Bariloche,8400 S.C. de Bariloche (Argentina); Instituto Balseiro (CNEA-UNC) and CONICET,8400 S.C. de Bariloche (Argentina); Graña, M. [Institut de Physique Théorique, CEA/ Saclay,91191 Gif-sur-Yvette Cedex (France); Iguri, S. [Instituto de Astronomía y Física del Espacio (CONICET-UBA), Universidad de Buenos Aires,1428 Buenos Aires (Argentina); Mayo, M. [Centro Atómico Bariloche,8400 S.C. de Bariloche (Argentina); Instituto Balseiro (CNEA-UNC) and CONICET,8400 S.C. de Bariloche (Argentina); Nuñez, C. [Instituto de Astronomía y Física del Espacio (CONICET-UBA), Universidad de Buenos Aires,1428 Buenos Aires (Argentina); Departamento de Física, FCEN, Universidad de Buenos Aires,C.C. 67 - Suc. 28, 1428 Buenos Aires (Argentina); Rosabal, J.A. [Departamento de Física, FCEN, Universidad de Buenos Aires,C.C. 67 - Suc. 28, 1428 Buenos Aires (Argentina)

2016-03-15

We provide an explicit example of how the string winding modes can be incorporated in double field theory. Our guiding case is the closed bosonic string compactified on a circle of radius close to the self-dual point, where some modes with non-zero winding or discrete momentum number become massless and enhance the U(1)×U(1) symmetry to SU(2)×SU(2). We compute three-point string scattering amplitudes of massless and slightly massive states, and extract the corresponding effective low energy gauge field theory. The enhanced gauge symmetry at the self-dual point and the Higgs-like mechanism arising when changing the compactification radius are examined in detail. The extra massless fields associated to the enhancement are incorporated into a generalized frame with ((O(d+3,d+3))/(O(d+3)×O(d+3))) structure, where d is the number of non-compact dimensions. We devise a consistent double field theory action that reproduces the low energy string effective action with enhanced gauge symmetry. The construction requires a truly non-geometric frame which explicitly depends on both the compact coordinate along the circle and its dual.

Symmetries and groups in particle physics

International Nuclear Information System (INIS)

Scherer, Stefan

2016-01-01

The aim of this book consists of a didactic introduction to the group-theoretical considerations and methods, which have led to an ever deeper understanding of the interactions of the elementary particles. The first three chapters deal primarily with the foundations of the representation theory of primarily finite groups, whereby many results are also transferable to compact Lie groups. In the third chapter we discuss the concept of Lie groups and their connection with Lie algebras. In the remaining chapter it is mainly about the application of group theory in physics. Chapter 4 deals with the groups SO(3) and SU(2), which occur in connection with the description of the angular momentum in quantum mechanics. We discuss the Wigner-Eckar theorem together with some applications. In chapter 5 we are employed to the composition properties of strongly interacting systems, so called hadrons, and discuss extensively the transformation properties of quarks with relation to the special unitary groups. The Noether theorem is generally treated in connection to the conservation laws belonging to the Galilei group and the Poincare group. We confine us in chapter 6 to internal symmetries, but explain for that extensively the application to quantum field theory. Especially an outlook on the effect of symmetries in form of so called Ward identities is granted. In chapter 7 we turn towards the gauge principle and discuss first the construction of quantum electrodynamics. In the following we generalize the gauge principle to non-Abelian groups (Yang-Mills theories) and formulate the quantum chromodynamics (QCD). Especially we take a view of ''random'' global symmetries of QCD, especially the chiral symmetry. In chapter 8 we illuminate the phenomenon of spontaneous symmetry breaking both for global and for local symmetries. In the final chapter we work out the group-theoretical structure of the Standard Model. Finally by means of the group SU(5) we take a view to

Symmetry restoration at high-temperature in two-color and two-flavor lattice gauge theories

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong-Wan [Department of Physics, College of Science, Swansea University,Singleton Park, SA2 8PP, Swansea, Wales (United Kingdom); Department of Physics, Pusan National University,Busan 46241 (Korea, Republic of); Extreme Physics Institute, Pusan National University,Busan 46241 (Korea, Republic of); Lucini, Biagio; Piai, Maurizio [Department of Physics, College of Science, Swansea University,Singleton Park, SA2 8PP, Swansea, Wales (United Kingdom)

2017-04-07

We consider the SU(2) gauge theory with N{sub f}=2 flavors of Dirac fundamental fermions. We study the high-temperature behavior of the spectra of mesons, discretizing the theory on anisotropic lattices, and measuring the two-point correlation functions in the temporal direction as well as screening masses in various channels. We identify the (pseudo-)critical temperature as the temperature at which the susceptibility associated with the Polyakov loop has a maximum. At high temperature both the spin-1 and spin-0 sectors of the light meson spectra exhibit enhanced symmetry properties, indicating the restoration of both the global SU(4) and the axial U(1){sub A} symmetries of the model.

New particle-hole symmetries and the extended interacting boson model

CERN Document Server

De Coster, C; Decroix, B; Heyde, Kris L G; Oros, A M

1998-01-01

We describe shape coexistence and intruder many-particle-hole (mp-nh)excitations in the extended interacting boson model EIBM and EIBM-2,combining both the particle-hole and the charge degree of freedom.Besides the concept of I-spin multiplets and subsequently $SU(4)$ multiplets, we touch upon the existence of particle-hole mixed symmetry states. We furthermore describe regular and intrudermany-particle-hole excitations in one nucleus on an equal footing, creating (annihilating) particle-hole pairs using the K-spin operatorand studying possible mixing between these states. As a limiting case,we treat the coupling of two IBM-1 Hamiltonians, each decribing the regular and intruder excitations respectively, in particular lookingat the $U(5)$-$SU(3)$ dynamical symmetry coupling. We apply such coupling scheme to the Po isotopes.

SU(N) multi-Skyrmions at finite volume

Energy Technology Data Exchange (ETDEWEB)

Canfora, Fabrizio [Centro de Estudios Cientificos (CECS), Casilla, Valdivia (Chile); Di Mauro, Marco; Naddeo, Adele [Universita di Salerno, Dipartimento di Fisica ' ' E.R. Caianiello' ' , Fisciano, SA (Italy); Kurkov, Maxim A. [Universita di Napoli Federico II, Dipartimento di Matematica e Applicazioni ' ' R. Caccioppoli' ' , Napoli (Italy)

2015-09-15

We study multi-soliton solutions of the fourdimensional SU(N) Skyrme model by combining the hedgehog ansatz for SU(N) based on the harmonic maps of S{sup 2} into CP{sup N-1} and a geometrical trick which allows to analyze explicitly finite-volume effects without breaking the relevant symmetries of the ansatz. The geometric set-up allows to introduce a parameter which is related to the ft Hooft coupling of a suitable large N limit, in which N → ∞ and the curvature of the background metric approaches zero, in such a way that their product is constant. The relevance of such a parameter to the physics of the system is pointed out. In particular, we discuss how the discrete symmetries of the configurations depend on it. (orig.)

An extension to SUf3 and Dirac particle of the transformation between physical bases and symmetry bases for dibaryon states

International Nuclear Information System (INIS)

Ping Jialun

1994-01-01

The transformation between physical bases and symmetry bases is extended from SU f 2 to SU f 3 . Its application in dibaryon calculation for both nonrelativistic and relativistic quark model is discussed

On Symmetries of Extremal Black Holes with One and Two Centers

CERN Document Server

Ferrara, Sergio

2013-01-01

After a brief introduction to the Attractor Mechanism, we review the appearance of groups of type E7 as generalized electric-magnetic duality symmetries in locally supersymmetric theories of gravity, with particular emphasis on the symplectic structure of fluxes in the background of extremal black hole solutions, with one or two centers. In the latter case, the role of an "horizontal" symmetry SL(2,R) is elucidated by presenting a set of two-centered relations governing the structure of two-centered invariant polynomials.

Lattice analysis of SU(2) chromodynamics with light quarks

International Nuclear Information System (INIS)

Laermann, E.

1986-01-01

I report on the Monte-Carlo simulation of a SU(2) lattice gauge theory which includes dynamical Kogut-Susskind quarks. On a 16*8 3 lattice the masses of ρ and π mesons are studied, the condensate measuring the chiral symmetry breaking determined, and the potential between static quarks measured. Extrapolations to vanishing quark mass yield a finite ρ mass but a value for the π mass which is compatible with zero, as well as a result different from zero for the quark condensate in accordance with the spontaneous breaking of the chiral symmetry of massless non-Abelian gauge theories. The shape of the q-anti q potential equals the pure gauge potential for small to intermediate distances. However at large distances (σ(fm)) deviations from the linear increase are indicated as they are expected due to the breakup of the flux tube between heavy quarks because of spontaneous quark-pair production. For all numerical calculations it is common that they favor a value for the scale parameter Λsub(anti Manti S)(N F =4) of quantum chromodynamics which is smaller than in the pure gauge field theory. (orig.) [de

Aspects of the SO(5) symmetry and the problem of high temperature superconductivity

Science.gov (United States)

Demler, Eugene A.

This dissertation reviews several aspects of the SO(5) theory, that unifies superconductivity and antiferromagnetism and that has recently been suggested in connection with the problem of high temperature superconductivity. Microscopic analysis of the pi operators (generators of the SO(5) symmetry) is given for the t-J and Hubbard models and it is argued that pseudo-Goldstone bosons that correspond to these operators produce resonant peaks observed in neutron scattering experiments on YBCO. Microscopic models with exact SO(5) symmetry are considered and the nature of the AF/SC transition in these systems is discussed. Analysis of a non-Abelian SU(2) holonomy of the SO (5) spinor states is presented, the SO(5) Berry's phase is shown to be related to the second Hopf map and described by a Yang monopole at the degeneracy point. These results are used to show that fermionic excitations in models with exact SO(5) symmetry may be described as four component Dirac fermions coupled to SU(2) gauge fields in 2 + 1 dimensions. Finally some experimental tests of the SO(5) model are suggested.

Dynamical Symmetries of Two-Dimensional Dirac Equation with Screened Coulomb and Isotropic Harmonic Oscillator Potentials

International Nuclear Information System (INIS)

Wang Qing; Hou Yu-Long; Jing Jian; Long Zheng-Wen

2014-01-01

In this paper, we study symmetrical properties of two-dimensional (2D) screened Dirac Hydrogen atom and isotropic harmonic oscillator with scalar and vector potentials of equal magnitude (SVPEM). We find that it is possible for both cases to preserve so(3) and su(2) dynamical symmetries provided certain conditions are satisfied. Interestingly, the conditions for preserving these dynamical symmetries are exactly the same as non-relativistic screened Hydrogen atom and screened isotropic oscillator preserving their dynamical symmetries. Some intuitive explanations are proposed. (general)

8x8 and 10x10 Hyperspace Representations of SU(3) and 10-fold Point-Symmetry Group of Quasicrystals

Science.gov (United States)

Animalu, Alexander

2012-02-01

In order to further elucidate the unexpected 10-fold point-symmetry group structure of quasi-crystals for which the 2011 Nobel Prize in chemistry was awarded to Daniel Shechtman, we explore a correspondence principle between the number of (projective) geometric elements (points[vertices] + lines[edges] + planes[faces]) of primitive cells of periodic or quasi-periodic arrangement of hard or deformable spheres in 3-dimensional space of crystallography and elements of quantum field theory of particle physics [points ( particles, lines ( particles, planes ( currents] and hence construct 8x8 =64 = 28+36 = 26 + 38, and 10x10 =100= 64 + 36 = 74 + 26 hyperspace representations of the SU(3) symmetry of elementary particle physics and quasicrystals of condensed matter (solid state) physics respectively, As a result, we predict the Cabibbo-like angles in leptonic decay of hadrons in elementary-particle physics and the observed 10-fold symmetric diffraction pattern of quasi-crystals.

SU(4) x U(1) gauge theory. II. CP nonconservation

International Nuclear Information System (INIS)

Deshpande, N.G.; Hwa, R.C.; Mannheim, P.D.

1979-01-01

We exploit the higher symmetry inherent in an SU(4) x U(1) gauge theory to construct a spontaneously broken theory of CP nonconservation. Higgs multiplets in the adjoint representation of SU(4) contain both even and odd CP fields; thus, requiring the simultaneous nonvanishing of the vacuum expectation values of these fields leads to CP noninvariance of the vacuum. We find that all the CP-nonconserving effects are mediated in our theory by the superheavy gauge bosons of the broken SU(4) x U(1) symmetry. In fact, the very existence of CP violation sets an upper limit on the masses of these bosons. In our model the dominant CP effect lies in the neutral kaon system and is found to arise through a direct (ΔS = 2) K 1 -K 2 transition. The model has all the features of a superweak theory, with a neutron electric dipole moment substantially smaller than 10 -24 e cm

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)

SU(2)xSU(2) coupling rule and a tensor glueball candidate

International Nuclear Information System (INIS)

Lanik, J.

1984-01-01

The data on the decay of THETA(1640) particles are considered. It is shown that the SU(2)xSU(2) mechanism for coupling of theta(1640) tensor glueball candidate to pseudoscalar Gold-stone mesons is in a remarkable agreement with existing experimental data

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)

Emergent Electroweak Symmetry Breaking with Composite W, Z Bosons

CERN Document Server

Cui, Yanou; Wells, James D

2009-01-01

We present a model of electroweak symmetry breaking in a warped extra dimension where electroweak symmetry is broken at the UV (or Planck) scale. An underlying conformal symmetry is broken at the IR (or TeV) scale generating masses for the electroweak gauge bosons without invoking a Higgs mechanism. By the AdS/CFT correspondence the W,Z bosons are identified as composite states of a strongly-coupled gauge theory, suggesting that electroweak symmetry breaking is an emergent phenomenon at the IR scale. The model satisfies electroweak precision tests with reasonable fits to the S and T parameter. In particular the T parameter is sufficiently suppressed since the model naturally admits a custodial SU(2) symmetry. The composite nature of the W,Z-bosons provide a novel possibility of unitarizing WW scattering via form factor suppression. Constraints from LEP and the Tevatron as well as discovery opportunities at the LHC are discussed for these composite electroweak gauge bosons.

Ab Initio Symmetry-Adapted No-Core Shell Model

International Nuclear Information System (INIS)

Draayer, J P; Dytrych, T; Launey, K D

2011-01-01

A multi-shell extension of the Elliott SU(3) model, the SU(3) symmetry-adapted version of the no-core shell model (SA-NCSM), is described. The significance of this SA-NCSM emerges from the physical relevance of its SU(3)-coupled basis, which – while it naturally manages center-of-mass spuriosity – provides a microscopic description of nuclei in terms of mixed shape configurations. Since typically configurations of maximum spatial deformation dominate, only a small part of the model space suffices to reproduce the low-energy nuclear dynamics and hence, offers an effective symmetry-guided framework for winnowing of model space. This is based on our recent findings of low-spin and high-deformation dominance in realistic NCSM results and, in turn, holds promise to significantly enhance the reach of ab initio shell models.

Applications of flavor symmetry to the phenomenology of elementary particles

International Nuclear Information System (INIS)

Kaeding, T.A.

1995-05-01

Some applications of flavor symmetry are examined. Approximate flavor symmetries and their consequences in the MSSM (Minimal Supersymmetric Standard Model) are considered, and found to give natural values for the possible B- and L-violating couplings that are empirically acceptable, except for the case of proton decay. The coupling constants of SU(3) are calculated and used to parameterize the decays of the D mesons in broken flavor SU(3). The resulting couplings are used to estimate the long-distance contributions to D-meson mixing

Symmetries of quantum spaces. Subgroups and quotient spaces of quantum SU(2) and SO(3) groups

International Nuclear Information System (INIS)

Podles, P.

1995-01-01

We prove that each action of a compact matrix quantum group on a compact quantum space can be decomposed into irreducible representations of the group. We give the formula for the corresponding multiplicities in the case of the quotient quantum spaces. We describe the subgroups and the quotient spaces of quantum SU(2) and SO(3) groups. (orig.)

Higgs boson from an extended symmetry

International Nuclear Information System (INIS)

Barbieri, Riccardo; Bellazzini, Brando; Rychkov, Vyacheslav S.; Varagnolo, Alvise

2007-01-01

The variety of ideas put forward in the context of a composite picture for the Higgs boson calls for a simple and effective description of the related phenomenology. Such a description is given here by means of a minimal model and is explicitly applied to the example of a Higgs-top sector from an SO(5) symmetry. We discuss the spectrum, the electroweak precision tests, B-physics, and naturalness. We show the difficulty in complying with the different constraints. The extended gauge sector relative to the standard SU(2)xU(1), if there is any, has little or no impact on these considerations. We also discuss the relation of the minimal model with its 'little Higgs' or holographic extensions based on the same symmetry

Deviation from bimaximal mixing and leptonic CP phases in S4 family symmetry and generalized CP

International Nuclear Information System (INIS)

Li, Cai-Chang; Ding, Gui-Jun

2015-01-01

The lepton flavor mixing matrix having one row or one column in common with the bimaximal mixing up to permutations is still compatible with the present neutrino oscillation data. We provide a thorough exploration of generating such a mixing matrix from S 4 family symmetry and generalized CP symmetry H CP . Supposing that S 4 ⋊H CP is broken down to Z 2 ST 2 SU ×H CP ν in the neutrino sector and Z 4 TST 2 U ⋊H CP l in the charged lepton sector, one column of the PMNS matrix would be of the form (1/2,1/√2,1/2) T up to permutations, both Dirac CP phase and Majorana CP phases are trivial to accommodate the observed lepton mixing angles. The phenomenological implications of the remnant symmetry K 4 (TST 2 ,T 2 U) ×H CP ν in the neutrino sector and Z 2 SU ×H CP l in the charged lepton sector are studied. One row of PMNS matrix is determined to be (1/2,1/2,−i/√2), and all the three leptonic CP phases can only be trivial to fit the measured values of the mixing angles. Two models based on S 4 family symmetry and generalized CP are constructed to implement these model independent predictions enforced by remnant symmetry. The correct mass hierarchy among the charged leptons is achieved. The vacuum alignment and higher order corrections are discussed.

Infinitesimal symmetries: a computational approach

International Nuclear Information System (INIS)

Kersten, P.H.M.

1985-01-01

This thesis is concerned with computational aspects in the determination of infinitesimal symmetries and Lie-Baecklund transformations of differential equations. Moreover some problems are calculated explicitly. A brief introduction to some concepts in the theory of symmetries and Lie-Baecklund transformations, relevant for this thesis, are given. The mathematical formalism is shortly reviewed. The jet bundle formulation is chosen, in which, by its algebraic nature, objects can be described very precisely. Consequently it is appropriate for implementation. A number of procedures are discussed, which enable to carry through computations with the help of a computer. These computations are very extensive in practice. The Lie algebras of infinitesimal symmetries of a number of differential equations in Mathematical Physics are established and some of their applications are discussed, i.e., Maxwell equations, nonlinear diffusion equation, nonlinear Schroedinger equation, nonlinear Dirac equations and self dual SU(2) Yang-Mills equations. Lie-Baecklund transformations of Burgers' equation, Classical Boussinesq equation and the Massive Thirring Model are determined. Furthermore, nonlocal Lie-Baecklund transformations of the last equation are derived. (orig.)

Phenomenology with supersymmetric flipped SU(6)

Energy Technology Data Exchange (ETDEWEB)

Shafi, Qaisar E-mail: shafi@bartol.udel.edu; Tavartkiladze, Zurab E-mail: tavzur@axpfe1.fe.infn.it

1999-07-12

The supersymmetric flipped SU(6) x U(1) gauge symmetry can arise through compactification of the ten-dimensional E{sub 8} x E{sub 8} superstring theory. We show how realistic phenomenology can emerge from this theory by supplementing it with the symmetry R x U(1), where R denotes a discrete 'R'-symmetry. The well-known doublet-triplet splitting problem is resolved to 'all orders' via the pseudo-Goldstone mechanism, and the GUT scale arises from an interplay of the Planck and supersymmetry breaking scales. The symmetry R x U(1) is also important for understanding the fermion mass hierarchies as well as the magnitudes of the CKM matrix elements. Furthermore, the well-known MSSM parameter tan {beta} is estimated to be of order unity, while the proton lifetime ({tau}{sub p} {approx} 10{sup 2}{tau}{sub pSU(5)}) is consistent with observations. Depending on some parameters, p {yields} K{mu}{sup +} can be the dominant decay mode. Finally, the observed solar and atmospheric neutrino 'anomalies' requir us to introduce a 'sterile' neutrino state. Remarkably, the R x U(1) symmetry protects it from becoming heavy, so that maximal angle {nu}{sub {mu}} oscillations into a sterile state can explain the atmospheric anomaly, while the solar neutrino puzzle is resolved via the small angle {nu}{sub e} - {nu}{sub {tau}} MSW oscillations. The existence of some ({approx} 15-20% of critical energy density) neutrino hot dark matter is also predicted.

Discrete gauge symmetries in discrete MSSM-like orientifolds

International Nuclear Information System (INIS)

Ibáñez, L.E.; Schellekens, A.N.; Uranga, A.M.

2012-01-01

Motivated by the necessity of discrete Z N symmetries in the MSSM to insure baryon stability, we study the origin of discrete gauge symmetries from open string sector U(1)'s in orientifolds based on rational conformal field theory. By means of an explicit construction, we find an integral basis for the couplings of axions and U(1) factors for all simple current MIPFs and orientifolds of all 168 Gepner models, a total of 32 990 distinct cases. We discuss how the presence of discrete symmetries surviving as a subgroup of broken U(1)'s can be derived using this basis. We apply this procedure to models with MSSM chiral spectrum, concretely to all known U(3)×U(2)×U(1)×U(1) and U(3)×Sp(2)×U(1)×U(1) configurations with chiral bi-fundamentals, but no chiral tensors, as well as some SU(5) GUT models. We find examples of models with Z 2 (R-parity) and Z 3 symmetries that forbid certain B and/or L violating MSSM couplings. Their presence is however relatively rare, at the level of a few percent of all cases.

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

Type IIA orientifolds on SU(2)-structure manifolds

Energy Technology Data Exchange (ETDEWEB)

Danckaert, Thomas

2010-11-15

We investigate the possible supersymmetry-preserving orientifold projections of type IIA string theory on a six-dimensional background with SU(2)-structure. We find two categories of projections which preserve half of the low-energy supersymmetry, reducing the effective theory from an N=4 supergravity theory, to an N=2 supergravity. For these two cases, we impose the projection on the low-energy spectrum and reduce the effective N=4 supergravity action accordingly. We can identify the resulting gauged N=2 supergravity theory and bring the action into canonical form. We compute the scalar moduli spaces and characterize the gauged symmetries in terms of the geometry of these moduli spaces. Due to their origin in N=4 supergravity, which is a highly constrained theory, the moduli spaces are of a very simple form. We find that, for suitable background manifolds, isometries in all scalar sectors can become gauged. The obtained gaugings share many features with those of N=2 supergravities obtained previously from other G-structure compactifications. (orig.)

Nonthermal leptogenesis via direct inflaton decay without SU(2)L triplets

International Nuclear Information System (INIS)

Dent, Thomas; Lazarides, George; Ruiz de Austri, Roberto

2005-01-01

We present a nonthermal leptogenesis scenario following standard supersymmetric hybrid inflation, in the case where light neutrinos acquire mass via the usual seesaw mechanism and inflaton decay to heavy right-handed neutrino superfields is kinematically disallowed, or the right-handed neutrinos which can be decay products of the inflaton are unable to generate sufficient baryon asymmetry via their subsequent decay. The primordial lepton asymmetry is generated through the decay of the inflaton into light particles by the interference of one-loop diagrams with exchange of different right-handed neutrinos. The mechanism requires superpotential couplings explicitly violating a U(1) R-symmetry and R-parity. We take into account the constraints from neutrino masses and mixing and the preservation of the primordial asymmetry. We consider two models, one without and one with SU(2) R gauge symmetry. We show that the former is viable, whereas the latter is ruled out. Although the broken R-parity need not have currently observable low-energy signatures, some R-parity-violating slepton decays may be detectable in the future colliders

Tracing symmetries and their breakdown through phases of heterotic (2,2) compactifications

Energy Technology Data Exchange (ETDEWEB)

Blaszczyk, Michael [Johannes-Gutenberg-Universität,Staudingerweg 7, 55099 Mainz (Germany); Oehlmann, Paul-Konstantin [Bethe Center for Theoretical Physics, Physikalisches Institut der Universität Bonn,Nussallee 12, 53115 Bonn (Germany)

2016-04-12

We are considering the class of heterotic N=(2,2) Landau-Ginzburg orbifolds with 9 fields corresponding to A{sub 1}{sup 9} Gepner models. We classify all of its Abelian discrete quotients and obtain 152 inequivalent models closed under mirror symmetry with N=1,2 and 4 supersymmetry in 4D. We compute the full massless matter spectrum at the Fermat locus and find a universal relation satisfied by all models. In addition we give prescriptions of how to compute all quantum numbers of the 4D states including their discrete R-symmetries. Using mirror symmetry of rigid geometries we describe orbifold and smooth Calabi-Yau phases as deformations away from the Landau-Ginzburg Fermat locus in two explicit examples. We match the non-Fermat deformations to the 4D Higgs mechanism and study the conservation of R-symmetries. The first example is a ℤ{sub 3} orbifold on an E{sub 6} lattice where the R-symmetry is preserved. Due to a permutation symmetry of blow-up and torus Kähler parameters the R-symmetry stays conserved also in the smooth Calabi-Yau phase. In the second example the R-symmetry gets broken once we deform to the geometric ℤ{sub 3}×ℤ{sub 3,free} orbifold regime.

Tracing symmetries and their breakdown through phases of heterotic (2,2) compactifications

International Nuclear Information System (INIS)

Blaszczyk, Michael; Oehlmann, Paul-Konstantin

2016-01-01

We are considering the class of heterotic N=(2,2) Landau-Ginzburg orbifolds with 9 fields corresponding to A 1 9 Gepner models. We classify all of its Abelian discrete quotients and obtain 152 inequivalent models closed under mirror symmetry with N=1,2 and 4 supersymmetry in 4D. We compute the full massless matter spectrum at the Fermat locus and find a universal relation satisfied by all models. In addition we give prescriptions of how to compute all quantum numbers of the 4D states including their discrete R-symmetries. Using mirror symmetry of rigid geometries we describe orbifold and smooth Calabi-Yau phases as deformations away from the Landau-Ginzburg Fermat locus in two explicit examples. We match the non-Fermat deformations to the 4D Higgs mechanism and study the conservation of R-symmetries. The first example is a ℤ 3 orbifold on an E 6 lattice where the R-symmetry is preserved. Due to a permutation symmetry of blow-up and torus Kähler parameters the R-symmetry stays conserved also in the smooth Calabi-Yau phase. In the second example the R-symmetry gets broken once we deform to the geometric ℤ 3 ×ℤ 3,free orbifold regime.

Tracing symmetries and their breakdown through phases of heterotic (2,2) compactifications

Science.gov (United States)

Blaszczyk, Michael; Oehlmann, Paul-Konstantin

2016-04-01

We are considering the class of heterotic N=(2,2) Landau-Ginzburg orbifolds with 9 fields corresponding to A 1 9 Gepner models. We classify all of its Abelian discrete quotients and obtain 152 inequivalent models closed under mirror symmetry with N=1 , 2 and 4 supersymmetry in 4D. We compute the full massless matter spectrum at the Fermat locus and find a universal relation satisfied by all models. In addition we give prescriptions of how to compute all quantum numbers of the 4D states including their discrete R-symmetries. Using mirror symmetry of rigid geometries we describe orbifold and smooth Calabi-Yau phases as deformations away from the Landau-Ginzburg Fermat locus in two explicit examples. We match the non-Fermat deformations to the 4D Higgs mechanism and study the conservation of R-symmetries. The first example is a Z_3 orbifold on an E6 lattice where the R-symmetry is preserved. Due to a permutation symmetry of blow-up and torus Kähler parameters the R-symmetry stays conserved also in the smooth Calabi-Yau phase. In the second example the R-symmetry gets broken once we deform to the geometric Z_3× Z_{3,free} orbifold regime.

Characterizing symmetries in a projected entangled pair state

Energy Technology Data Exchange (ETDEWEB)

Perez-Garcia, D; Gonzalez-Guillen, C E [Departamento Analisis Matematico and IMI, Universidad Complutense de Madrid, 28040 Madrid (Spain); Sanz, M; Cirac, J I [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching (Germany); Wolf, M M [Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen (Denmark)], E-mail: dperez@mat.ucm.es

2010-02-15

We show that two different tensors defining the same translational invariant injective projected entangled pair state (PEPS) in a square lattice must be the same up to a trivial gauge freedom. This allows us to characterize the existence of any local or spatial symmetry in the state. As an application of these results we prove that a SU(2) invariant PEPS with half-integer spin cannot be injective, which can be seen as a Lieb-Shultz-Mattis theorem in this context. We also give the natural generalization for U(1) symmetry in the spirit of Oshikawa-Yamanaka-Affleck, and show that a PEPS with Wilson loops cannot be injective.

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.

The su(2 vertical bar 3) dynamic spin chain

International Nuclear Information System (INIS)

Beisert, Niklas

2004-01-01

The complete one-loop, planar dilatation operator of the N=4 superconformal gauge theory was recently derived and shown to be integrable. Here, we present further compelling evidence for a generalisation of this integrable structure to higher orders of the coupling constant. For that we consider the su(2 vertical bar 3) subsector and investigate the restrictions imposed on the spin chain Hamiltonian by the symmetry algebra. This allows us to uniquely fix the energy shifts up to the three-loop level and thus prove the correctness of a conjecture in hep-th/0303060. A novel aspect of this spin chain model is that the higher-loop Hamiltonian, as for N=4 SYM in general, does not preserve the number of spin sites. Yet this dynamic spin chain appears to be integrable

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 +})

Flipped SO(10) model

Energy Technology Data Exchange (ETDEWEB)

Maekawa, Nobuhiro; Yamashita, Toshifumi

2003-08-14

This Letter demonstrates that, as in flipped SU(5) models, doublet-triplet splitting is accomplished by a missing partner mechanism in flipped SO(10) models. The gauge group SO(10){sub F}xU(1){sub V'{sub F}} includes SU(2){sub E} gauge symmetry, which plays an important role in solving the supersymmetric (SUSY) flavor problem by introducing non-abelian horizontal gauge symmetry and anomalous U(1){sub A} gauge symmetry. The gauge group can be broken into the standard model gauge group by VEVs of only spinor fields; such models may be easier to derive than E{sub 6} models from superstring theory.

PT symmetry and a dynamical realization of the SU(1, 1) algebra

Science.gov (United States)

Banerjee, Rabin; Mukherjee, Pradip

2016-01-01

We show that the elementary modes of the planar harmonic oscillator can be quantized in the framework of quantum mechanics based on pseudo-hermitian Hamiltonians. These quantized modes are demonstrated to act as dynamical structures behind a new Jordan-Schwinger realization of the SU(1, 1) algebra. This analysis complements the conventional Jordan-Schwinger construction of the SU(2) algebra based on hermitian Hamiltonians of a doublet of oscillators.

Symmetry breaking by Wilson loops in gauge field theory

International Nuclear Information System (INIS)

Dowker, J.S.; Jadhav, S.P.

1989-01-01

An analysis is presented of the gauge symmetry breaking caused by Wilson loops on a space-time whose spatial section is openR/sup d/ x S 3 /Γ, for all those fundamental groups Γ that give a homogeneous space. We concentrate on pure SU(3) and SU(5) gauge field theories and find that symmetry breaking can occur when d = 0, for all Γ. If d = 3, the extra minimal scalars prevent any breaking and one must include other fields to achieve this. Explicit forms for the vacuum energies are exhibited in the case of lens and prism spaces, the former for SU(n). For Γ = Z/sub m/, when m and the radius of the sphere become infinite, we recover the results on the space-time openR/sup d//sup +3/ x S 1

Scanning anisotropy parameters in horizontal transversely isotropic media

KAUST Repository

Masmoudi, Nabil; Stovas, Alexey; Alkhalifah, Tariq Ali

2016-01-01

in reservoir characterisation, specifically in terms of fracture delineation. We propose a travel-time-based approach to estimate the anellipticity parameter η and the symmetry axis azimuth ϕ of a horizontal transversely isotropic medium, given an inhomogeneous

Resonant Interaction, Approximate Symmetry, and Electromagnetic Interaction (EMI) in Low Energy Nuclear Reactions (LENR)

Science.gov (United States)

Chubb, Scott

2007-03-01

Only recently (talk by P.A. Mosier-Boss et al, in this session) has it become possible to trigger high energy particle emission and Excess Heat, on demand, in LENR involving PdD. Also, most nuclear physicists are bothered by the fact that the dominant reaction appears to be related to the least common deuteron(d) fusion reaction,d+d ->α+γ. A clear consensus about the underlying effect has also been illusive. One reason for this involves confusion about the approximate (SU2) symmetry: The fact that all d-d fusion reactions conserve isospin has been widely assumed to mean the dynamics is driven by the strong force interaction (SFI), NOT EMI. Thus, most nuclear physicists assume: 1. EMI is static; 2. Dominant reactions have smallest changes in incident kinetic energy (T); and (because of 2), d+d ->α+γ is suppressed. But this assumes a stronger form of SU2 symmetry than is present; d+d ->α+γ reactions are suppressed not because of large changes in T but because the interaction potential involves EMI, is dynamic (not static), the SFI is static, and because the two incident deuterons must have approximate Bose Exchange symmetry and vanishing spin. A generalization of this idea involves a resonant form of reaction, similar to the de-excitation of an atom. These and related (broken gauge) symmetry EMI effects on LENR are discussed.

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)

Flavor distributions in the nucleons: SU(2) sea asymmetry or isospin symmetry breaking?

International Nuclear Information System (INIS)

Ma, B.; Schaefer, A.; Greiner, W.

1993-01-01

The Gottfried sum-rule violation reported by the New Muon Collaboration was interpreted as an indication for a flavor asymmetry of the sea quark in the nucleon. We investigate the alternative possibility that isospin symmetry between the proton and the neutron is breaking for small x. We examine systematically the consequences of this possibility for several processes, namely, neutrino deep inelastic scattering, the charged pion Drell-Yan process, the proton Drell-Yan process, and semi-inclusive deep inelastic scattering, and conclude that a decision between the two alternative explanations is possible

Effective Lagrangian approach to the fermion mass problem

International Nuclear Information System (INIS)

Shaw, D.S.; Volkas, R.R.

1994-01-01

An effective theory is proposed, combining the standard gauge group SU(3) C direct-product SU(2) L direct-product U(1) Y with a horizontal discrete symmetry. By assigning appropriate charges under this discrete symmetry to the various fermion fields and to (at least) two Higgs doublets, the broad spread of the fermion mass and mixing angle spectrum can be explained as a result of suppressed, non-renormalizable terms. A particular model is constructed which achieves the above while simultaneously suppressing neutral Higgs-induced flavour-changing processes. 9 refs., 3 tabs., 1 fig

Scanning anisotropy parameters in horizontal transversely isotropic media

KAUST Repository

Masmoudi, Nabil

2016-10-12

The horizontal transversely isotropic model, with arbitrary symmetry axis orientation, is the simplest effective representative that explains the azimuthal behaviour of seismic data. Estimating the anisotropy parameters of this model is important in reservoir characterisation, specifically in terms of fracture delineation. We propose a travel-time-based approach to estimate the anellipticity parameter η and the symmetry axis azimuth ϕ of a horizontal transversely isotropic medium, given an inhomogeneous elliptic background model (which might be obtained from velocity analysis and well velocities). This is accomplished through a Taylor\\'s series expansion of the travel-time solution (of the eikonal equation) as a function of parameter η and azimuth angle ϕ. The accuracy of the travel time expansion is enhanced by the use of Shanks transform. This results in an accurate approximation of the solution of the non-linear eikonal equation and provides a mechanism to scan simultaneously for the best fitting effective parameters η and ϕ, without the need for repetitive modelling of travel times. The analysis of the travel time sensitivity to parameters η and ϕ reveals that travel times are more sensitive to η than to the symmetry axis azimuth ϕ. Thus, η is better constrained from travel times than the azimuth. Moreover, the two-parameter scan in the homogeneous case shows that errors in the background model affect the estimation of η and ϕ differently. While a gradual increase in errors in the background model leads to increasing errors in η, inaccuracies in ϕ, on the other hand, depend on the background model errors. We also propose a layer-stripping method valid for a stack of arbitrary oriented symmetry axis horizontal transversely isotropic layers to convert the effective parameters to the interval layer values.

Relations between the SU(2|4) symmetric theories and the gauge gravity correspondence

International Nuclear Information System (INIS)

Tsuchiya, Asato

2008-01-01

We study theories with SU(2|4) symmetry, which include N=4 SYM on R x S 3 /Z k , 2+1 SYM on R x S 2 and the plane wave matrix model. All these theories possess many vacua. From Lin-Maldacena's method which gives the gravity dual of each vacuum, it is suggested that the theory around each vacuum of N=4 SYM on R x S 3 /Z k and 2+1 SYM on R x S 2 is equivalent to the theory around a certain vacuum of the plane wave matrix model. We show this directly on the gauge theory side. We realize theories around multi-monopole backgrounds in matrix model, and extend Taylor's matrix T-duality to that on spheres. (author)

Implications of an arithmetical symmetry of the commutant for modular invariants

International Nuclear Information System (INIS)

Ruelle, P.; Thiran, E.; Weyers, J.

1993-01-01

We point out the existence of an arithmetical symmetry for the commutant of the modular matrices S and T. This symmetry holds for all affine simple Lie algebras at all levels and implies the equality of certain coefficients in any modular invariant. Particularizing to SU(3) k , we classify the modular invariant partition functions when k+3 is an integer coprime with 6 and when it is a power of either 2 or 3. Our results imply that no detailed knowledge of the commutant is needed to undertake a classification of all modular invariants. (orig.)

Independent SU(2)-loop variables

International Nuclear Information System (INIS)

Loll, R.

1991-04-01

We give a reduction procedure for SU(2)-trace variables and introduce a complete set of indepentent, gauge-invariant and almost local loop variables for the configuration space of SU(2)-lattice gauge theory in 2+1 dimensions. (orig.)

Flavor symmetry breaking and meson masses

International Nuclear Information System (INIS)

Bhagwat, Mandar S.; Roberts, Craig D.; Chang Lei; Liu Yuxin; Tandy, Peter C.

2007-01-01

The axial-vector Ward-Takahashi identity is used to derive mass formulas for neutral pseudoscalar mesons. Flavor symmetry breaking entails nonideal flavor content for these states. Adding that the η ' is not a Goldstone mode, exact chiral-limit relations are developed from the identity. They connect the dressed-quark propagator to the topological susceptibility. It is confirmed that in the chiral limit the η ' mass is proportional to the matrix element which connects this state to the vacuum via the topological susceptibility. The implications of the mass formulas are illustrated using an elementary dynamical model, which includes an Ansatz for that part of the Bethe-Salpeter kernel related to the non-Abelian anomaly. In addition to the current-quark masses, the model involves two parameters, one of which is a mass-scale. It is employed in an analysis of pseudoscalar- and vector-meson bound-states. While the effects of SU(N f =2) and SU(N f =3) flavor symmetry breaking are emphasized, the five-flavor spectra are described. Despite its simplicity, the model is elucidative and phenomenologically efficacious; e.g., it predicts η-η ' mixing angles of ∼-15 deg. and π 0 -η angles of ∼1 deg

Supersymmetric models for quarks and leptons with nonlinearly realized E8 symmetry

International Nuclear Information System (INIS)

Ong, C.L.

1985-01-01

We propose three supersymmetric nonlinear sigma models with global symmetry E 8 . The models can accommodate three left-handed families of quarks and leptons without incurring the Adler-Bell-Jackiw anomaly with respect to either the standard SU(3) x SU(2) x U(1) gauge group, or the SU(5), or SO(10) grand unifying gauge group. They also predict unambiguously a right-handed, fourth family of quarks and leptons. In order to explore the structure of the models, we develop a differential-form formulation of the Kahler manifolds, resulting in general expressions for the curvature tensors and other geometrical objects in terms of the structure constants of the algebra, and the squashing parameters. These results, in turn, facilitate a general method for determining the Lagrangian to quartic order, and so the structure of the inherent four-fermion interactions of the models. We observe that the Kahlerian condition dω = 0 on the fundamental two-form ω greatly reduces the number of the independent squashing parameters. We also point out two plausible mechanisms for symmetry breaking, involving gravity

Heavy Higgs boson with a light sneutrino next-to-lightest supersymmetric particle in the MSSM with enhanced SU(2) D-terms

International Nuclear Information System (INIS)

Medina, Anibal D.; Shah, Nausheen R.; Wagner, Carlos E. M.

2009-01-01

The minimal supersymmetric extension of the standard model provides a solution to the hierarchy problem and leads to the presence of a light Higgs. A Higgs boson with mass above the present experimental bound may only be obtained for relatively heavy third generation squarks, requiring a precise, somewhat unnatural balance between different contributions to the effective Higgs mass parameter. It was recently noticed that somewhat heavier Higgs bosons, which are naturally beyond the CERN LEP bound, may be obtained by enhanced weak SU(2) D-terms. Such contributions appear in models with an enhanced electroweak gauge symmetry, provided the supersymmetry breaking masses associated with the scalars responsible for the breakdown of the enhanced gauge symmetry group to the standard model one are larger than the enhanced symmetry breaking scale. In this article we emphasize that the enhanced SU(2) D-terms will not only raise the Higgs boson mass but also affect the spectrum of the nonstandard Higgs bosons, sleptons, and squarks, which therefore provide a natural contribution to the T parameter, compensating for the negative one coming from the heavy Higgs boson. The sleptons and nonstandard Higgs bosons of these models, in particular, may act in a way similar to the so-called inert Higgs doublet. The phenomenological properties of these models are emphasized, and possible cosmological implications as well as collider signatures are described.

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

Mass generation and chiral symmetry breaking by pseudoparticles

International Nuclear Information System (INIS)

Hietarinta, J.; Palmer, W.F.; Pinsky, S.S.

1978-01-01

Massless QCD is studied with regard to mass generation and chiral SU(N/sub f/) symmetry breaking from pseudoparticle effects. While mass is generated when there is only one massless quark, and chiral U(1) is always broken, no rigorous indication of the breaking of chiral SU(N/sub f/) and mass generation is seen when there are more than one massless quarks in the original theory

Symmetry restoration in the Georgi-Glashow model at finite temperature

International Nuclear Information System (INIS)

Guerra Junior, J.M.

1985-01-01

Symmetry restoration in the SU(5) model is analysed by means of finite temperature field theory. In our calculations symmetry restoration is due to topological defects which appear thanks to thermodynamical effects. We apply our results in cosmology, in order to explain the primordial inhomogeneity. Our results are compatible with Zeldovich's spectrum. (author) [pt

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)

Finite size giant magnons in the SU(2) x SU(2) sector of AdS4 x CP3

International Nuclear Information System (INIS)

Lukowski, Tomasz; Sax, Olof Ohlsson

2008-01-01

We use the algebraic curve and Luescher's μ-term to calculate the leading order finite size corrections to the dispersion relation of giant magnons in the SU(2) x SU(2) sector of AdS 4 x CP 3 . We consider a single magnon as well as one magnon in each SU(2). In addition the algebraic curve computation is generalized to give the leading order correction for an arbitrary multi-magnon state in the SU(2) x SU(2) sector.

Path integrals and coherent states of SU(2) and SU(1,1)

CERN Document Server

Inomata, Akira; Kuratsuji, Hiroshi

1992-01-01

The authors examine several topical subjects, commencing with a general introduction to path integrals in quantum mechanics and the group theoretical backgrounds for path integrals. Applications of harmonic analysis, polar coordinate formulation, various techniques and path integrals on SU(2) and SU(1, 1) are discussed. Soluble examples presented include particle-flux system, a pulsed oscillator, magnetic monopole, the Coulomb problem in curved space and others.The second part deals with the SU(2) coherent states and their applications. Construction and generalization of the SU(2) coherent sta

Gauge theories of weak interactions with left-right symmetry and the structure of neutral currents

International Nuclear Information System (INIS)

Mohapatra, R.N.; Sidhu, D.P.

1977-01-01

Failure to detect parity-violating effects in atomic transitions by Oxford and Washington groups would appear to rule out the Weinberg-Salam SU(2) x U(1) model as well as any variation of it that respects natural conservation laws for charm and strangeness to order a G/sub F/ (called ''natural'') and obeys quark-lepton symmetry. In this paper, a simple left-right--symmetric model based on the SU(2)/sub L/ x SU(2)/sub R/ x U(1) group with four and six quark flavors is analyzed and found to accomodate the results of the atomic experiments as well as the other features of neutral-current phenomena

SO(8) fermion dynamical symmetry and strongly correlated quantum Hall states in monolayer graphene

Science.gov (United States)

Wu, Lian-Ao; Murphy, Matthew; Guidry, Mike

2017-03-01

A formalism is presented for treating strongly correlated graphene quantum Hall states in terms of an SO(8) fermion dynamical symmetry that includes pairing as well as particle-hole generators. The graphene SO(8) algebra is isomorphic to an SO(8) algebra that has found broad application in nuclear physics, albeit with physically very different generators, and exhibits a strong formal similarity to SU(4) symmetries that have been proposed to describe high-temperature superconductors. The well-known SU(4) symmetry of quantum Hall ferromagnetism for single-layer graphene is recovered as one subgroup of SO(8), but the dynamical symmetry structure associated with the full set of SO(8) subgroup chains extends quantum Hall ferromagnetism and allows analytical many-body solutions for a rich set of collective states exhibiting spontaneously broken symmetry that may be important for the low-energy physics of graphene in strong magnetic fields. The SO(8) symmetry permits a natural definition of generalized coherent states that correspond to symmetry-constrained Hartree-Fock-Bogoliubov solutions, or equivalently a microscopically derived Ginzburg-Landau formalism, exhibiting the interplay between competing spontaneously broken symmetries in determining the ground state.

SU(2) symmetry and degeneracy from SUSY QM of a neutron in the magnetic field of a linear current

International Nuclear Information System (INIS)

Martinez, D.; Granados, V.D.; Mota, R.D.

2006-01-01

From SUSY ladder operators in momentum space of a neutron in the magnetic field of a linear current, we construct 2x2 matrix operators that together with the z-component of the total angular momentum satisfy the su(2) Lie algebra. We use this fact to explain the degeneracy of the energy spectrum

Ratios of B and D meson decay constants with heavy quarks symmetry

International Nuclear Information System (INIS)

Giri, A.K.; Maharana, L.; Mohanta, R.

1996-01-01

SU(3) flavor symmetry allows the decay constants f Ds , and f Dd as well as f Bs , and f Bd , to be equal. But due to SU(3) flavor symmetry breaking the ratios f Bs /f Bd and f Ds /f Dd are deviated from unity. We have estimated these ratios in the heavy quark effective theory and obtained f Bs /f Bd = 0.93, f Ds /f Dd = 0.94 and the double ratio (f Bs /f Bd )/(f Ds /f Dd ) = 0.99. (author). 22 refs

Flipped SU(6) from ten dimensions

Energy Technology Data Exchange (ETDEWEB)

Panagiotakopoulos, C. (Bartol Research Inst., Univ. of Delaware, Newark, DE (US))

1990-06-20

The authors study the compactification of the heterotic supersting on the only known three generation Calabi-Yau space with flux breakings leading to SU(6) {times} U(1) as the gauge group in four dimensions. We compute the massless spectrum and identify the discrete symmetries of the internal space that survive flux breaking. The possible four-dimensional models are classified according to their honest discrete symmetries. The allowed breaking chains of SU(6) {times} U(1) are listed. Model building with SU(6) {times} U(1) is discussed in general and a concrete realistic model is constructed which does not suffer from the gauge hierarchy problem, fast proton decay or any other obvious phenomenological disaster. A distinct experimental signature of this class of models is the presence in the low energy spectrum of vector-like quarks and antiquarks, outside the three known families, with masses of the order of the supersymmetry breaking scale.

Symmetry breaking and scalar bosons

International Nuclear Information System (INIS)

Gildener, E.; Weinberg, S.

1976-01-01

There are reasons to suspect that the spontaneous breakdown of the gauge symmetries of the observed weak and electromagnetic interactions may be produced by the vacuum expectation values of massless weakly coupled elementary scalar fields. A method is described for finding the broken-symmetry solutions of such theories even when they contain arbitrary numbers of scalar fields with unconstrained couplings. In any such theory, there should exist a number of heavy Higgs bosons, with masses comparable to the intermediate vector bosons, plus one light Higgs boson, or ''scalon'' with mass of order αG/sub F/sub 1/2/. The mass and couplings of the scalon are calculable in terms of other masses, even without knowing all the details of the theory. For an SU(2) direct-product U(1) model with arbitrary numbers of scalar isodoublets, the scalon mass is greater than 5.26 GeV; a likely value is 7--10 GeV. The production and decay of the scalon are briefly considered. Some comments are offered on the relation between the mass scales associated with the weak and strong interactions

Gauging the graded conformal group with unitary internal symmetries

International Nuclear Information System (INIS)

Ferrara, S.; Townsend, P.K.; Kaku, M.; Nieuwenhuizen Van, P.

1977-06-01

Gauge theories for extended SU(N) conformal supergravity are constructed which are invariant under local scale, chiral, proper conformal, supersymmetry and internal SU(N) transformations. The relation between intrinsic parity and symmetry properties of their generators of the internal vector mesons is established. These theories contain no cosmological constants, but technical problems inherent to higher derivative actions are pointed out

Flavor symmetry in the large Nc limit

International Nuclear Information System (INIS)

Karl, G.; Washington Univ., Seattle, WA; Lipkin, H.J.; Washington Univ., Seattle, WA

1991-01-01

An essential difference between two-flavor and three-flavor descriptions of baryons in large N c QCD is discussed in detail. For N c ≥3 a state with the SU(3) flavor quantum numbers of the proton must contain a number of strange quarks n s ≥(N c -3)/3, while a state with no strange quarks must have extra hypercharge Y-1 = 3/N c -1. The extra strangeness or extra hypercharge which vanishes for N c = 3 is spurious for the physical proton. This problem does not arise in two-flavor QCD, where the flavor-SU(2) Skyrmion may give a good approximation for nucleon-pion physics at low energies below strangeness threshold. But any nucleon model with SU(3) flavor symmetry which is interpreted as arising from the large N c limit in QCD can lead to erroneous conclusions about the spin and flavor structure of the proton. 12 refs

Static properties of baryons in the SU(3) Skyrme model

International Nuclear Information System (INIS)

Sriram, M.S.; Mani, H.S.; Ramachandran, R.

1984-01-01

We study the SU(3) x SU(3) Skyrme model with explicit chiral- and flavor-symmetry-breaking terms. We evaluate the SU(3)-symmetric meson-baryon coupling-constant ratio α, SU(3) mass breaking in the octet and decuplet, and the ΔI = 1 part of the electromagnetic mass splitting in baryons. The theoretical numbers are in reasonable agreement with the experimental values

Chiral symmetry breaking and the spin content of the ρ and ρ' mesons

International Nuclear Information System (INIS)

Glozman, L.Ya.; Lang, C.B.; Limmer, M.

2011-01-01

Using interpolators with different SU(2) L xSU(2) R transformation properties we study the chiral symmetry and spin contents of the ρ and ρ ' mesons in lattice simulations with dynamical quarks. A ratio of couplings of the q-bar γ i τq and q-bar σ 0i τq interpolators to a given meson state at different resolution scales tells one about the degree of chiral symmetry breaking in the meson wave function at these scales. Using a Gaussian gauge invariant smearing of the quark fields in the interpolators, we are able to extract the chiral content of mesons up to the infrared resolution of ∼1 fm. In the ground state ρ meson the chiral symmetry is strongly broken with comparable contributions of both the (0,1)+(1,0) and (1/2,1/2) b chiral representations with the former being the leading contribution. In contrast, in the ρ ' meson the degree of chiral symmetry breaking is manifestly smaller and the leading representation is (1/2,1/2) b . Using a unitary transformation from the chiral basis to the 2S+1 L J basis, we are able to define and measure the angular momentum content of mesons in the rest frame. This definition is different from the traditional one which uses parton distributions in the infinite momentum frame. The ρ meson is practically a 3 S 1 state with no obvious trace of a 'spin crisis'. The ρ ' meson has a sizeable contribution of the 3 D 1 wave, which implies that the ρ ' meson cannot be considered as a pure radial excitation of the ρ meson.

Soliton surfaces associated with generalized symmetries of integrable equations

International Nuclear Information System (INIS)

Grundland, A M; Post, S

2011-01-01

In this paper, based on the Fokas et al approach (Fokas and Gel'fand 1996 Commun. Math. Phys. 177 203-20; Fokas et al 2000 Sel. Math. 6 347-75), we provide a symmetry characterization of continuous deformations of soliton surfaces immersed in a Lie algebra using the formalism of generalized vector fields, their prolongation structure and links with the Frechet derivatives. We express the necessary and sufficient condition for the existence of such surfaces in terms of the invariance criterion for generalized symmetries and identify additional sufficient conditions which admit an explicit integration of the immersion functions of 2D surfaces in Lie algebras. We discuss in detail the su(N)-valued immersion functions generated by conformal symmetries of the CP N-1 sigma model defined on either the Minkowski or Euclidean space. We further show that the sufficient conditions for explicit integration of such immersion functions impose additional restrictions on the admissible conformal symmetries of the model defined on Minkowski space. On the other hand, the sufficient conditions are identically satisfied for arbitrary conformal symmetries of finite action solutions of the CP N-1 sigma model defined on Euclidean space.

Semiclassical approach to squeezing-like transformations in quantum systems with higher symmetries

International Nuclear Information System (INIS)

Klimov, Andrei B; Dinani, Hossein Tavakoli; De Guise, Hubert

2013-01-01

We provide a coarse but intuitive classification of squeezing in quantum systems with SU(n) symmetries. This classification is based on the non-equivalent paths (classical trajectories) in the corresponding phase-space. The example of SU(3) is studied in details. (paper)

Anomalies of hidden local chiral symmetries in sigma-models and extended supergravities

International Nuclear Information System (INIS)

Vecchia, P. di; Ferrara, S.; Girardello, L.

1985-01-01

Non-linear sigma-models with hidden gauge symmetries are anomalous, at the quantum level, when coupled to chiral fermions in not anomaly free representations of the hidden chiral symmetry. These considerations generally apply to supersymmetric kaehlerian sigma-models on coset spaces with hidden chiral symmetries as well as to extended supergravities in four dimensions with local SU(N) symmetry. The presence of the anomaly implies that the scenario of dynamical generation of gauge vector bosons has to be reconsidered in these theories. (orig.)

Using MT2 to distinguish dark matter stabilization symmetries

International Nuclear Information System (INIS)

Agashe, Kaustubh; Kim, Doojin; Zhu Lijun; Walker, Devin G. E.

2011-01-01

We examine the potential of using colliders to distinguish models with parity (Z 2 ) stabilized dark matter (DM) from models in which the DM is stabilized by other symmetries, taking the latter to be a Z 3 symmetry for illustration. The key observation is that a heavier mother particle charged under a Z 3 stabilization symmetry can decay into one or two DM particles along with standard model particles. This can be contrasted with the decay of a mother particle charged under a parity symmetry; typically, only one DM particle appears in the decay chain. The arXiv:1003.0899 studied the distributions of visible invariant mass from the decay of a single such mother particle in order to highlight the resulting distinctive signatures of Z 3 symmetry versus parity symmetry stabilized dark matter candidates. We now describe a complementary study which focuses on decay chains of the two mother particles which are necessarily present in these events. We also include in our analysis the missing energy/momentum in the event. For the Z 3 symmetry stabilized mothers, the resulting inclusive final state can have two, three or four DM particles. In contrast, models with Z 2 symmetry can have only two. We show that the shapes and edges of the distribution of M T2 -type variables, along with ratio of the visible momentum/energy on the two sides of the event, are powerful in distinguishing these different scenarios. Finally we conclude by outlining future work which focuses on reducing combinatoric ambiguities from reconstructing multijet events. Increasing the reconstruction efficiency can allow better reconstruction of events with two or three dark matter candidates in the final state.

SU(2 color NJL model and EOS of quark-hadron matter at finite temperature and density

Directory of Open Access Journals (Sweden)

Weise Wolfram

2012-02-01

Full Text Available We study the NJL model with the Polyakov loop in the SU(2-color case for the EOS of quark-hadron matter at finite temperature and density. We consider the spontaneous chiral symmetry breaking and the diquark condensation together with the behavior of the Polyakov loop for the phase diagram of quark-hadron matter. We discuss the spectrum of mesons and diquark baryons (boson at finite temperature and density.We derive also the linear sigma model Lagrangian for diquark baryon and mesons.

Quasi-SU(3) truncation scheme for even-even sd-shell nuclei

International Nuclear Information System (INIS)

Vargas, C.E.; Hirsch, J.G.; Draayer, J.P.

2001-01-01

The quasi-SU(3) symmetry was uncovered in full pf and sdg shell-model calculations for both even-even and odd-even nuclei. It manifests itself through a dominance of single-particle and quadrupole-quadrupole terms in a Hamiltonian used to describe well-deformed nuclei. A practical consequence of the quasi-SU(3) symmetry is an efficient basis truncation scheme. In [C.E. Vargas et al., Phys. Rev. C 58 (1998) 1488] it is shown that when this type of Hamiltonian is diagonalized in an SU(3) basis, only a few irreducible representations (irreps) of SU(3) are needed to describe the yrast band, the leading S=0 irrep augmented with the leading S=1 irreps in the proton and neutron subspaces. In the present article the quasi-SU(3) truncation scheme is used, in conjunction with a 'realistic but schematic' Hamiltonian that includes the most important multipole terms, to describe the energy spectra and B(E2) transition strengths of 20,22 Ne, 24 Mg and 28 Si. The effect of the size of the Hilbert space on both sets of observables is discussed, as well as the structure of the yrast band and the importance of the various terms in the Hamiltonian. The limitations of the model are explicitly discussed

An SU(2) x SU(2) symmetric Higgs-Fermion model with staggered fermions

International Nuclear Information System (INIS)

Berlin, J.; Heller, U.M.

1991-01-01

We have simulated on SU(2)xSU(2) symmetric Higgs-Fermion model with a four component scalar field coupled with a Yukawa type coupling to two flavours of staggered fermions. The results show two qualitatively different behaviours in the broken phase. One for weak coupling where the fermion masses obey the perturbative tree level relation M F =y , and one for strong coupling where the behaviour agrees with a 1/d expansion. (orig.)

Deformations of spacetime and internal symmetries

Directory of Open Access Journals (Sweden)

Gresnigt Niels G.

2017-01-01

Full Text Available Algebraic deformations provide a systematic approach to generalizing the symmetries of a physical theory through the introduction of new fundamental constants. The applications of deformations of Lie algebras and Hopf algebras to both spacetime and internal symmetries are discussed. As a specific example we demonstrate how deforming the classical flavor group S U(3 to the quantum group S Uq(3 ≡ U q (su(3 (a Hopf algebra and taking into account electromagnetic mass splitting within isospin multiplets leads to new and exceptionally accurate baryon mass sum rules that agree perfectly with experimental data.

Cosmoparticle physics of family symmetry breaking

International Nuclear Information System (INIS)

Khlopov, M.Yu.

1993-07-01

The foundations of both particle theory and cosmology are hidden at super energy scale and can not be tested by direct laboratory means. Cosmoparticle physics is developed to probe these foundations by the proper combination of their indirect effects, thus providing definite conclusions on their reliability. Cosmological and astrophysical tests turn to be complementary to laboratory searches of rare processes, induced by new physics, as it can be seen in the case of gauge theory of broken symmetry of quark and lepton families, ascribing to the hierarchy of the horizontal symmetry breaking the observed hierarchy of masses and the mixing between quark and lepton families. 36 refs

Symmetry broken and restored coupled-cluster theory: I. Rotational symmetry and angular momentum

International Nuclear Information System (INIS)

Duguet, T

2015-01-01

We extend coupled-cluster (CC) theory performed on top of a Slater determinant breaking rotational symmetry to allow for the exact restoration of the angular momentum at any truncation order. The main objective relates to the description of near-degenerate finite quantum systems with an open-shell character. As such, the newly developed many-body formalism offers a wealth of potential applications and further extensions dedicated to the ab initio description of, e.g., doubly open-shell atomic nuclei and molecule dissociation. The formalism, which encompasses both single-reference CC theory and projected Hartree–Fock theory as particular cases, permits the computation of usual sets of connected diagrams while consistently incorporating static correlations through the highly non-perturbative restoration of rotational symmetry. Interestingly, the yrast spectroscopy of the system, i.e. the lowest energy associated with each angular momentum, is accessed within a single calculation. A key difficulty presently overcome relates to the necessity to handle generalized energy and norm kernels for which naturally terminating CC expansions could be eventually obtained. The present work focuses on SU(2) but can be extended to any (locally) compact Lie group and to discrete groups, such as most point groups. In particular, the formalism will be soon generalized to U(1) symmetry associated with particle number conservation. This is relevant to Bogoliubov CC theory that was recently applied to singly open-shell nuclei. (paper)

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

Energy Technology Data Exchange (ETDEWEB)

Faraggi, Alon E. E-mail: faraggi@thphys.ox.ac.uk; Garavuso, Richard E-mail: garavuso@thphys.ox.ac.uk; Isidro, Jose M. E-mail: isidro@thphys.ox.ac.uk

2002-10-07

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

Neutrino masses and a low breaking scale of left-right symmetry

International Nuclear Information System (INIS)

Khasanov, Oleg; Perez, Gilad

2002-01-01

In left-right symmetric models (LRSMs) the light neutrino masses arise from two sources: the seesaw mechanism and a vacuum expectation value of an SU(2) L triplet. If the left-right symmetry breaking v R is low, v R (less-or-similar sign)15 TeV, the contributions to the light neutrino masses from both the seesaw mechanism and the triplet Yukawa couplings are expected to be well above the experimental bounds. We present a minimal LRSM with an additional U(1) symmetry in which the masses induced by the two sources are below the eV scale and the twofold problem is solved. We further show that, if the U(1) symmetry is also responsible for the lepton flavor structure, the model yields a small mixing angle within the first two lepton generations

Studies on phenomenological hadron models with chiral symmetry

International Nuclear Information System (INIS)

Rathske, E.

1991-12-01

In this report we consider, in the context of phenomenological models for hadrons, several aspects of Skyrme-type and hybrid bag models. In the first of the two central parts we discuss two qualitatively different generalizations of the minimal SU(2) Skyrme model. One of these consists in adding to the Lagrangian density a symmetric term of fourth order in the field derivatives. Its consequences are determined for solutions and observables by analytical and numerical investigations. In the other we propose a contribution for explicit isospin symmetry breaking in the mesonic as well as the baryonic sector. Together with the standard nonlinear σ-model term it allows for exact time-dependent classical soliton solutions. Their quantization leads to a quantitative connection between the hadronic isospin mass differenced of pions and nucleons. The second main part of this report is devoted to the generalization of SU(2) bag models under the aspect of chiral symmetry. We first show that the construction of appropriate surface terms in the Lagrangian density necessitates the introduction of dynamical bosonic degrees of freedom. This allows for a variety of bag scenarios (including the 'endopionic' bag). We then consider explicit isospin symmetry breaking for hybrid bag models with a nonlinear mesonic sector. An intimate relationship is revealed between the effects of a quark mass difference and the time-dependent bosonic solutions found for the purely mesonic case. It is reflected in a nontrivial interdependence between quark and meson masses, bag radius and chiral angle. We provide an especially extensive list of references for the topics discussed in this report. (orig.) [de

On the value and origin of the chiral condensate in quenched SU(2) lattice gauge theory

International Nuclear Information System (INIS)

Hands, S.J.; Teper, M.; Oxford Univ.

1990-01-01

We present results of a numerical calculation of the chiral condensate in quenched SU(2) lattice gauge theory. The calculation proceeds by evaluating the spectral density distribution function for small eigenvalues on both the original lattice and after a factor-of-two blocking. It is performed on lattices as large as 20 4 and for couplings as small as β=4/g 2 =2.6. The fitted values of the condensate as a function of β show good evidence for scaling and universality when compared with string tension measurements at the same value. At the smallest lattice spacings considered, we find evidence that a separation of length scales between ultraviolet fluctuations and those responsible for chiral symmetry breaking has occurred. A more qualitative study yields a significant correlation between the small modes vertical stroken> responsible for the non-zero value of and topological activity as revealed by the expectation value 5 x1/n(>, and hence provides evidence for a topological origin of chiral symmetry breaking. Our interpretation is supported by a subsidiary calculation of the topological susceptibility of the vacuum. (orig.)

Chiral symmetry breaking and the spin content of the ρ and ρ‧ mesons

Science.gov (United States)

Glozman, L. Ya.; Lang, C. B.; Limmer, M.

2011-11-01

Using interpolators with different SU(2)L × SU(2)R transformation properties we study the chiral symmetry and spin contents of the ρ and ρ‧ mesons in lattice simulations with dynamical quarks. A ratio of couplings of the qbarγi τq and qbarσ0i τq interpolators to a given meson state at different resolution scales tells one about the degree of chiral symmetry breaking in the meson wave function at these scales. Using a Gaussian gauge invariant smearing of the quark fields in the interpolators, we are able to extract the chiral content of mesons up to the infrared resolution of ∼ 1 fm. In the ground state ρ meson the chiral symmetry is strongly broken with comparable contributions of both the (0 , 1) + (1 , 0) and (1 / 2 , 1 / 2) b chiral representations with the former being the leading contribution. In contrast, in the ρ‧ meson the degree of chiral symmetry breaking is manifestly smaller and the leading representation is (1 / 2 , 1 / 2) b. Using a unitary transformation from the chiral basis to the LJ2S+1 basis, we are able to define and measure the angular momentum content of mesons in the rest frame. This definition is different from the traditional one which uses parton distributions in the infinite momentum frame. The ρ meson is practically a 3S1 state with no obvious trace of a "spin crisis". The ρ‧ meson has a sizeable contribution of the 3D1 wave, which implies that the ρ‧ meson cannot be considered as a pure radial excitation of the ρ meson.

Pure classical SU(2) Yang-Mills theory with potentials invariant under a U(1) gauge subgroup

International Nuclear Information System (INIS)

Bacry, H.

1978-07-01

The present article is devoted to pure SU(2) classical Yang-Mills theories whose potentials are invariant under a U(1) gauge subgroup. Such potentials are shown to be associated with classical Maxwell-like fields with magnetic sources as 't Hooft's monopole is associated with the Dirac magnetic monopole. Conversely, the authors give Yang-Mills potentials corresponding to some Maxwell-like fields, in particular static magnetic fields with emphasis on those with cylindrical symmetry (including the dipole and other multipoles) and the ephemerons corresponding to an instantaneous magnetic multipole

Laughlin states on the Poincare half-plane and its quantum group symmetry

OpenAIRE

Alimohammadi, M.; Sadjadi, H. Mohseni

1996-01-01

We find the Laughlin states of the electrons on the Poincare half-plane in different representations. In each case we show that there exist a quantum group $su_q(2)$ symmetry such that the Laughlin states are a representation of it. We calculate the corresponding filling factor by using the plasma analogy of the FQHE.

Discrete R symmetries for the MSSM and its singlet extensions

CERN Document Server

Lee, Hyun Min; Ratz, Michael; Ross, Graham G; Schieren, Roland; Schmidt-Hoberg, Kai; Vaudrevange, Patrick K S

2011-01-01

We determine the anomaly free discrete R symmetries, consistent with the MSSM, that commute with SU(5) and suppress the $\\mu$ parameter and nucleon decay. We show that the order M of such $Z_M^R$ symmetries has to divide 24 and identify 5 viable symmetries. The simplest possibility is a $Z_4^R$ symmetry which commutes with SO(10). We present a string-derived model with this $Z_4^R$ symmetry and the exact MSSM spectrum below the GUT scale; in this model $Z_4^R$ originates from the Lorentz symmetry of compactified dimensions. We extend the discussion to include the singlet extensions of the MSSM and find $Z_4^R$ and $Z_8^R$ are the only possible symmetries capable of solving the $\\mu$ problem in the NMSSM. We also show that a singlet extension of the MSSM based on a $Z_{24}^R$ symmetry can provide a simultaneous solution to the $\\mu$ and strong CP problem with the axion coupling in the favoured window.

On ''conformal spinor geometry'': An attempt to ''understand'' internal symmetry

International Nuclear Information System (INIS)

Budinich, P.

1981-09-01

The natural homomorphism of pure spinors corresponding to a given Clifford algebra Csub(2n) to polarized isotropic n-planes of complex Euclidean space Esub(2n)sup(c) is taken as a starting point for the construction of a geometry called spinor geometry where pure spinors are the only elements out of which all tensors have to be constructed (analytically as bilinear polynomia of the components of a pure spinor). C 4 and C 6 spinor geometry are analyzed but it seems that C 8 spinor geometry is necessary to construct Minkowski space Msup(3,1). C 6 spinor field equations give rise in Minkowski space to a pair of Dirac equations (for conformal semispinors) presenting an SU(2) internal symmetry algebra. Mass is generated by spontaneously breaking the original O(4,2) symmetry of the spinor equation. (author)

On ''conformal spinor geometry'': An attempt to ''understand'' internal symmetry

International Nuclear Information System (INIS)

Budinich, P.

1982-01-01

The natural homomorphism of pure spinors corresponding to a given Clifford algebra Csub(2n) to polarized isotropic n-planes of complex Euclidean space Esub(2n)sup(c) is taken as a starting point for the construction of a geometry called spinor geometry where pure spinors are the only elements out of which all tensors have to be constructed (analytically as bilinear polynomials of the components of a pure spinor). C 4 and C 6 spinor geometry are analyzed, but it seems that C 8 spinor geometry is necessary to construct Minkowski space Msup(3,1). C 6 spinor field equations give rise in Minkowski space to a pair of Dirac equations (for conformal semispinors) presenting an su(2) internal symmetry algebra. Mass is generated by breaking spontaneously the original O(4,2) symmetry of the spinor equation. (author)

Coherent states for polynomial su(2) algebra

International Nuclear Information System (INIS)

Sadiq, Muhammad; Inomata, Akira

2007-01-01

A class of generalized coherent states is constructed for a polynomial su(2) algebra in a group-free manner. As a special case, the coherent states for the cubic su(2) algebra are discussed. The states so constructed reduce to the usual SU(2) coherent states in the linear limit

Balanced Hermitian metrics from SU(2)-structures

International Nuclear Information System (INIS)

Fernandez, M.; Tomassini, A.; Ugarte, L.; Villacampa, R.

2009-01-01

We study the intrinsic geometrical structure of hypersurfaces in six-manifolds carrying a balanced Hermitian SU(3)-structure, which we call balanced SU(2)-structure. We provide sufficient conditions, in terms of suitable evolution equations, which imply that a five-manifold with such structure can be isometrically embedded as a hypersurface in a balanced Hermitian SU(3)-manifold. Any five-dimensional compact nilmanifold has an invariant balanced SU(2)-structure, and we show how some of them can be evolved to give new explicit examples of balanced Hermitian SU(3)-structures. Moreover, for n=3,4, we present examples of compact solvmanifolds endowed with a balanced SU(n)-structure such that the corresponding Bismut connection has holonomy equal to SU(n)

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

Critical behaviour of SU(n) quantum chains and topological non-linear σ-models

International Nuclear Information System (INIS)

Affleck, I.; British Columbia Univ., Vancouver

1988-01-01

The critical behaviour of SU(n) quantum ''spin'' chains, Wess-Zumino-Witten σ-models and grassmanian σ-models at topological angle θ = π (of possible relevance to the quantum Hall effect) is reexamined. It is argued that an additional Z n symmetry is generally necessary to stabilize the massless phase. This symmetry is not present for the σ-models for n>2 and is only present for certain representations of ''spin'' chains. (orig.)

Fermi-Surface Topological Phase Transition and Horizontal Order-Parameter Nodes in CaFe2As2 Under Pressure

Science.gov (United States)

Gonnelli, R. S.; Daghero, D.; Tortello, M.; Ummarino, G. A.; Bukowski, Z.; Karpinski, J.; Reuvekamp, P. G.; Kremer, R. K.; Profeta, G.; Suzuki, K.; Kuroki, K.

2016-05-01

Iron-based compounds (IBS) display a surprising variety of superconducting properties that seems to arise from the strong sensitivity of these systems to tiny details of the lattice structure. In this respect, systems that become superconducting under pressure, like CaFe2As2, are of particular interest. Here we report on the first directional point-contact Andreev-reflection spectroscopy (PCARS) measurements on CaFe2As2 crystals under quasi-hydrostatic pressure, and on the interpretation of the results using a 3D model for Andreev reflection combined with ab-initio calculations of the Fermi surface (within the density functional theory) and of the order parameter symmetry (within a random-phase-approximation approach in a ten-orbital model). The almost perfect agreement between PCARS results at different pressures and theoretical predictions highlights the intimate connection between the changes in the lattice structure, a topological transition in the holelike Fermi surface sheet, and the emergence on the same sheet of an order parameter with a horizontal node line.

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

Geometry and time scales of self-consistent orbits in a modified SU(2) model

International Nuclear Information System (INIS)

Jezek, D.M.; Hernandez, E.S.; Solari, H.G.

1986-01-01

We investigate the time-dependent Hartree-Fock flow pattern of a two-level many fermion system interacting via a two-body interaction which does not preserve the parity symmetry of standard SU(2) models. The geometrical features of the time-dependent Hartree-Fock energy surface are analyzed and a phase instability is clearly recognized. The time evolution of one-body observables along self-consistent and exact trajectories are examined together with the overlaps between both orbits. Typical time scales for the determinantal motion can be set and the validity of the time-dependent Hartree-Fock approach in the various regions of quasispin phase space is discussed

Constraints on GUTS with Coleman-Weinberg symmetry breaking

International Nuclear Information System (INIS)

Sher, M.A.

1981-01-01

A popular assumption introduced by Coleman and Weinberg is that the elementary Higgs scalars of a gauge theory are massless at the tree level; the symmetry breakdown is then entirely due to quantum radiative corrections. In grand unified theories (GUTS), this assumption becomes particularly attractive. Many GUTS have intermediate mass scales [scales of symmetry breaking between baryon number generation and SU(2) x U(1) breaking], and it is attractive to apply the Coleman-Weinberg assumption to all stages of symmetry breaking after baryon number generation. In this paper, it is shown that most such GUTS are phenomenologically unacceptable. The reason is that as the universe cools, at each scale of symmetry breaking there will be a phase transition; if the symmetry is broken a la Coleman-Weinberg, this transition is strongly first order and thus generates entropy, decreasing the previously generated baryon number to entropy ratio by a large, and perhaps unacceptable amount. The entropy generated in a general intermediate mass scale transition is calculated, and the severe constraints that any Coleman-Weinberg-type GUT with intermediate mass scales must satisfy (in order to avoid excessive entropy generation) are found. Turning to specific models, it is shown that all intermediate mass scale transitions associated with SO(10) do not satisfy these constraints; the Coleman-Weinberg form of these transitions is inconsistent with cosmological observations and is thus phenomenologically unacceptable. (orig.)

Individual eigenvalue distributions of crossover chiral random matrices and low-energy constants of SU(2) × U(1) lattice gauge theory

Science.gov (United States)

Yamamoto, Takuya; Nishigaki, Shinsuke M.

2018-02-01

We compute individual distributions of low-lying eigenvalues of a chiral random matrix ensemble interpolating symplectic and unitary symmetry classes by the Nyström-type method of evaluating the Fredholm Pfaffian and resolvents of the quaternion kernel. The one-parameter family of these distributions is shown to fit excellently the Dirac spectra of SU(2) lattice gauge theory with a constant U(1) background or dynamically fluctuating U(1) gauge field, which weakly breaks the pseudoreality of the unperturbed SU(2) Dirac operator. The observed linear dependence of the crossover parameter with the strength of the U(1) perturbations leads to precise determination of the pseudo-scalar decay constant, as well as the chiral condensate in the effective chiral Lagrangian of the AI class.

Quasi-SU(3) truncation scheme for even-even sd-shell nuclei

Energy Technology Data Exchange (ETDEWEB)

Vargas, C.E. E-mail: cvargas@fis.cinvestav.mx; Hirsch, J.G. E-mail: hirsch@nuclecu.unam.mx; Draayer, J.P. E-mail: draayer@lsu.edu

2001-07-30

The quasi-SU(3) symmetry was uncovered in full pf and sdg shell-model calculations for both even-even and odd-even nuclei. It manifests itself through a dominance of single-particle and quadrupole-quadrupole terms in a Hamiltonian used to describe well-deformed nuclei. A practical consequence of the quasi-SU(3) symmetry is an efficient basis truncation scheme. In [C.E. Vargas et al., Phys. Rev. C 58 (1998) 1488] it is shown that when this type of Hamiltonian is diagonalized in an SU(3) basis, only a few irreducible representations (irreps) of SU(3) are needed to describe the yrast band, the leading S=0 irrep augmented with the leading S=1 irreps in the proton and neutron subspaces. In the present article the quasi-SU(3) truncation scheme is used, in conjunction with a 'realistic but schematic' Hamiltonian that includes the most important multipole terms, to describe the energy spectra and B(E2) transition strengths of {sup 20,22}Ne, {sup 24}Mg and {sup 28}Si. The effect of the size of the Hilbert space on both sets of observables is discussed, as well as the structure of the yrast band and the importance of the various terms in the Hamiltonian. The limitations of the model are explicitly discussed.

Independent SU(2)-loop variables and the reduced configuration space of SU(2)-lattice gauge theory

International Nuclear Information System (INIS)

Loll, R.

1992-01-01

We give a reduction procedure for SU(2)-trace variables and an explicit description of the reduced configuration sace of pure SU(2)-gauge theory on the hypercubic lattices in two, three and four dimensions, using an independent subset of the gauge-invariant Wilson loops. (orig.)

SU (2) with fundamental fermions and scalars

DEFF Research Database (Denmark)

Hansen, Martin; Janowski, Tadeusz; Pica, Claudio

2018-01-01

We present preliminary results on the lattice simulation of an SU(2) gauge theory with two fermion flavors and one strongly interacting scalar field, all in the fundamental representation of SU(2). The motivation for this study comes from the recent proposal of "fundamental" partial compositeness...... the properties of light meson resonances previously obtained for the SU(2) model. Preprint: CP3-Origins-2017-047 DNRF90...

Classification of compactified su( N c ) gauge theories with fermions in all representations

Science.gov (United States)

Anber, Mohamed M.; Vincent-Genod, Loïc

2017-12-01

We classify su( N c ) gauge theories on R^3× S^1 with massless fermions in higher representations obeying periodic boundary conditions along S^1 . In particular, we single out the class of theories that is asymptotically free and weakly coupled in the infrared, and therefore, is amenable to semi-classical treatment. Our study is conducted by carefully identifying the vacua inside the affine Weyl chamber using Verma bases and Frobenius formula techniques. Theories with fermions in pure representations are generally strongly coupled. The only exceptions are the four-index symmetric representation of su(2) and adjoint representation of su( N c ). However, we find a plethora of admissible theories with fermions in mixed representations. A sub-class of these theories have degenerate perturbative vacua separated by domain walls. In particular, su( N c ) theories with fermions in the mixed representations adjoint⊕fundamental and adjoint⊕two-index symmetric admit degenerate vacua that spontaneously break the parity P , charge conjugation C , and time reversal T symmetries. These are the first examples of strictly weakly coupled gauge theories on R^3× S^1 with spontaneously broken C , P , and T symmetries. We also compute the fermion zero modes in the background of monopole-instantons. The monopoles and their composites (topological molecules) proliferate in the vacuum leading to the confinement of electric charges. Interestingly enough, some theories have also accidental degenerate vacua, which are not related by any symmetry. These vacua admit different numbers of fermionic zero modes, and hence, different kinds of topological molecules. The lack of symmetry, however, indicates that such degeneracy might be lifted by higher order corrections. Finally, we study the general phase structure of adjoint⊕fundamental theories in the small circle and decompactification limits.

SU(4) Kondo effect in double quantum dots with ferromagnetic leads

Science.gov (United States)

Weymann, Ireneusz; Chirla, Razvan; Trocha, Piotr; Moca, Cǎtǎlin Paşcu

2018-02-01

We investigate the spin-resolved transport properties, such as the linear conductance and the tunnel magnetoresistance, of a double quantum dot device attached to ferromagnetic leads and look for signatures of the SU (4 ) symmetry in the Kondo regime. We show that the transport behavior greatly depends on the magnetic configuration of the device, and the spin-SU(2) as well as the orbital and spin-SU(4) Kondo effects become generally suppressed when the magnetic configuration of the leads varies from the antiparallel to the parallel one. Furthermore, a finite spin polarization of the leads lifts the spin degeneracy and drives the system from the SU(4) to an orbital-SU(2) Kondo state. We analyze in detail the crossover and show that the Kondo temperature between the two fixed points has a nonmonotonic dependence on the degree of spin polarization of the leads. In terms of methods used, we characterize transport by using a combination of analytical and numerical renormalization group approaches.

Symmetry of dipositronium Ps2

International Nuclear Information System (INIS)

Schrader, D.M.

2004-01-01

We work out the complete symmetry and spin problem for diatomic positronium Ps 2 for the ground and singly excited states of zero orbital angular momentum. The general form of the wave function for each state is given, with due regard to charge conjugation parity. Annihilation rates are discussed, and correlations to dissociation products are deduced. We indicate how the approach is extensible to larger aggregates: i.e., PsPs n , n>2

Spinor Structure and Internal Symmetries

Science.gov (United States)

Varlamov, V. V.

2015-10-01

Spinor structure and internal symmetries are considered within one theoretical framework based on the generalized spin and abstract Hilbert space. Complex momentum is understood as a generating kernel of the underlying spinor structure. It is shown that tensor products of biquaternion algebras are associated with the each irreducible representation of the Lorentz group. Space-time discrete symmetries P, T and their combination PT are generated by the fundamental automorphisms of this algebraic background (Clifford algebras). Charge conjugation C is presented by a pseudoautomorphism of the complex Clifford algebra. This description of the operation C allows one to distinguish charged and neutral particles including particle-antiparticle interchange and truly neutral particles. Spin and charge multiplets, based on the interlocking representations of the Lorentz group, are introduced. A central point of the work is a correspondence between Wigner definition of elementary particle as an irreducible representation of the Poincaré group and SU(3)-description (quark scheme) of the particle as a vector of the supermultiplet (irreducible representation of SU(3)). This correspondence is realized on the ground of a spin-charge Hilbert space. Basic hadron supermultiplets of SU(3)-theory (baryon octet and two meson octets) are studied in this framework. It is shown that quark phenomenologies are naturally incorporated into presented scheme. The relationship between mass and spin is established. The introduced spin-mass formula and its combination with Gell-Mann-Okubo mass formula allows one to take a new look at the problem of mass spectrum of elementary particles.

Vibrational states as a representations of a SU(6) group

International Nuclear Information System (INIS)

Abdulvahabova, S.G.; Barkhalova, N.Sh.; Bayramova, T.O.

2012-01-01

Full text : In any event it is proved that a description of collective states in terms of a SU(6) model might be appropriate, especially in the two limiting situations in which the approximate symmetries O + (5) and SU(3) occur. For nuclei whose spectrum is not too far from these exact symmetries it might be useful to use the respective unperturbed wave functions and energies. The symmetry structure of the nuclear many body system is in general very complex. However, since only few degrees of freedom play a dominant role in the description of the collective states, it is hoped that the Hamiltonian of the system when written in terms of these degrees of freedom has simple symmetry properties. It is important to notice that our collective Hamiltonian yields a finite energy matrix for a given value of N and a definite spin. This is a consequence of the symmetry properties of our collective operators. Because the boson-boson interaction in Hamiltonian splits the degeneracy of the multiplets, this limit describes an anharmonic vibrator. It is worth nothing that the knowledge of the invariance properties of the Hamiltonian provides directly a solution to the eigenvalue problem.

SU(2) and SU(1,1) squeezing of interacting radiation modes

International Nuclear Information System (INIS)

Abdalla Sebawe, M.; Faisal El-Orany, A.A.; Perina, J.

2000-01-01

In this communication we discuss SU(1,1) and SU(2) squeezing of an interacting system of radiation modes in a quadratic medium in the framework of Lie algebra. We show that regardless of which state being initially considered, squeezing can be periodically generated. (authors)

Body image dissatisfaction in patients undergoing breast reconstruction: Examining the roles of breast symmetry and appearance investment.

Science.gov (United States)

Teo, Irene; Reece, Gregory P; Huang, Sheng-Cheng; Mahajan, Kanika; Andon, Johnny; Khanal, Pujjal; Sun, Clement; Nicklaus, Krista; Merchant, Fatima; Markey, Mia K; Fingeret, Michelle Cororve

2018-03-01

Reconstruction as part of treatment for breast cancer is aimed at mitigating body image concerns after mastectomy. Although algorithms have been developed to objectively assess breast reconstruction outcomes, associations between objectively quantified breast aesthetic appearance and patient-reported body image outcomes have not been examined. Further, the role of appearance investment in explaining a patient's body image is not well understood. We investigated the extent to which objectively quantified breast symmetry and patient-reported appearance investment were associated with body image dissatisfaction in patients undergoing cancer-related breast reconstruction. Breast cancer patients in different stages of reconstruction (n = 190) completed self-report measures of appearance investment and body image dissatisfaction. Vertical extent and horizontal extent symmetry values, which are indicators of breast symmetry, were calculated from clinical photographs. Associations among breast symmetry, appearance investment, body image dissatisfaction, and patient clinical factors were examined. Multi-variable regression was used to evaluate the extent to which symmetry and appearance investment were associated with body image dissatisfaction. Vertical extent symmetry, but not horizontal extent symmetry, was associated with body image dissatisfaction. Decreased vertical extent symmetry (β = -.19, P image dissatisfaction while controlling for clinical factors. Breast symmetry and patient appearance investment both significantly contribute to an understanding of patient-reported body image satisfaction during breast reconstruction treatment. Copyright © 2017 John Wiley & Sons, Ltd.

The generation problem

International Nuclear Information System (INIS)

Ecker, G.

1983-01-01

Evidence for the generation structure of quarks and leptons is reviewed. The two main aspects of the generation problem are emphasized. The concept and possible problems of horizontal symmetries are discussed. Two different mechanisms for horizontal symmetries are considered leading to a generalized permutation symmetry in SU(2)sub(L) x u(1) in one case. The second mechanism uses the discrete unbroken subgroup of an axial U(1) with hypercolour anomalies in composite models. A concrete realization in the rishon model is investigated. The two different approaches produce almost identical quark mass matrices for three generations. In addition to a correct prediction for the Cabibbo angle the models yield a very small Kobayashi-Maskawa mixing angle Theta 3 and thus provide for a natural explanation of the smallness of CP violation. (Author)

Local U(2,2) Symmetry in Relativistic Quantum Mechanics

OpenAIRE

Finster, Felix

1997-01-01

Local gauge freedom in relativistic quantum mechanics is derived from a measurement principle for space and time. For the Dirac equation, one obtains local U(2,2) gauge transformations acting on the spinor index of the wave functions. This local U(2,2) symmetry allows a unified description of electrodynamics and general relativity as a classical gauge theory.

Local U(2,2) symmetry in relativistic quantum mechanics

Science.gov (United States)

Finster, Felix

1998-12-01

Local gauge freedom in relativistic quantum mechanics is derived from a measurement principle for space and time. For the Dirac equation, one obtains local U(2,2) gauge transformations acting on the spinor index of the wave functions. This local U(2,2) symmetry allows a unified description of electrodynamics and general relativity as a classical gauge theory.

Dynamical Symmetry Breaking of Extended Gauge Symmetries

OpenAIRE

Appelquist, Thomas; Shrock, Robert

2003-01-01

We construct asymptotically free gauge theories exhibiting dynamical breaking of the left-right, strong-electroweak gauge group $G_{LR} = {\\rm SU}(3)_c \\times {\\rm SU}(2)_L \\times {\\rm SU}(2)_R \\times {\\rm U}(1)_{B-L}$, and its extension to the Pati-Salam gauge group $G_{422}={\\rm SU}(4)_{PS} \\times {\\rm SU}(2)_L \\times {\\rm SU}(2)_R$. The models incorporate technicolor for electroweak breaking, and extended technicolor for the breaking of $G_{LR}$ and $G_{422}$ and the generation of fermion ...

Gl(2/2)-oscillators and Gl(2/2)-dynamical symmetry

International Nuclear Information System (INIS)

Kamupingene, A.H.; Nguyen Anh Ky.

1991-07-01

Extending the concept of the dynamical symmetry, we identify the Lie superalgebra Gl(2/2) as a dynamical (super-)algebra of a class of non-canonical quantum systems, whose dynamical variables and quantities can be realized in terms of the Gl(2/2)-generators. In this way, a new class of harmonic oscillators is established. As a consequence of the choice of the dynamical variables the Heisenberg algebra and the Hermitian condition for the Gl(2/2)-representations are also given. (author). 12 refs

The SU(3)-Nambu-Jona-Lasinio soliton in the collective quantization formulation

International Nuclear Information System (INIS)

Blotz, A.; Goeke, K.; Diakonov, D.; Petrov, V.; Pobylitsa, P.V.; Park, N.W.

1992-01-01

On grounds of a semibosonized Nambu-Jona-Lasinio model, which has SU(3) R circle-times SU(3) L -symmetry in the chiral limit, mass splittings for spin 1/2 and spin 3/2 baryons are studied in the presence of an explicit chiral symmetry breaking strange quark mass. To this aim these strangeness carrying baryons are understood as SU(3)-rotational excitations of an SU(2)-embedded soliton solution. Therefore, within the framework of collective quantization, the fermion determinant with the strange quark mass is expanded up to the second order in the flavor rotation velocity and up to the first order in this quark mass. Besides the strange and non-strange moments of inertia, which have some counterparts within the Skyrme model, some so-called anomalous moments of inertia are obtained. These call be related to the imaginary part of the effective Euclidian action and contain among others the anomalous baryon current. This is shown in a gradient expansion up to the first non-vanishing order. Together with the Σ-commutator these are the solitonic ingredients of the collective hamiltonian, which is then diagonalized by means of strict perturbation theory in the strange quark mass and by the Yabu-Audo method. Both methods yield very good results for the masses of the spin 1/2 and 3/2 baryons. The former one reproduces some interesting mass formulas of Gell-Mann Okubo and Guadagnini and the latter one is able to describe the mass splittings up to a few MeV

Spin energy levels in axial symmetry: spin 3/2

Energy Technology Data Exchange (ETDEWEB)

de Biasi, R S; Portella, P D [Instituto Militar de Engenharia, Rio de Janeiro (Brazil). Secao de Engenharia e Ciencia dos Materiais

1977-01-01

The spin energy levels in axial symmetry are presented, in graphical and tabular form, for a spin 3/2. The levels are calculated for five different angles between the applied field and the symmetry axis: 0/sup 0/, 30/sup 0/, 45/sup 0/, 60/sup 0/ and 90/sup 0/.

Chiral symmetry breaking in gauge theories from Reggeon diagram analysis

International Nuclear Information System (INIS)

White, A.R.

1991-01-01

It is argued that reggeon diagrams can be used to study dynamical properties of gauge theories containing a large number of massless fermions. SU(2) gauge theory is studied in detail and it is argued that there is a high energy solution which is analogous to the solution of the massless Schwinger model. A generalized winding-number condensate produces the massless pseudoscalar spectrum associated with chiral symmetry breaking and a ''trivial'' S-Matrix

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.)

Study of the Local Horizon. (Spanish Title: Estudio del Horizonte Local.) Estudo do Horizonte Local

Science.gov (United States)

Ros, Rosa M.

2009-12-01

The study of the horizon is fundamental to easy the first observations of the students at any education center. A simple model, to be developed in each center, allows to easy the study and comprehension of the rudiments of astronomy. The constructed model is presented in turn as a simple equatorial clock, other models (horizontal and vertical) may be constructed starting from it. El estudio del horizonte es fundamental para poder facilitar las primeras observaciones de los alumnos en un centro educativo. Un simple modelo, que debe realizarse para cada centro, nos permite facilitar el estudio y la comprensión de los primeros rudimentos astronómicos. El modelo construido se presenta a su vez como un sencillo modelo de reloj ecuatorial y a partir de él se pueden construir otros modelos (horizontal y vertical). O estudo do horizonte é fundamental para facilitar as primeiras observações dos alunos num centro educativo. Um modelo simples, que deve ser feito para cada centro, permite facilitar o estudo e a compreensão dos primeiros rudimentos astronômicos. O modelo construído apresenta-se, por sua vez, como um modelo simples de relógio equatorial e a partir dele pode-se construir outros modelos (horizontal e vertical)

Symmetry boost of the fidelity of Shor factoring

Science.gov (United States)

Nam, Y. S.; Blümel, R.

2018-05-01

In Shor's algorithm quantum subroutines occur with the structure F U F-1 , where F is a unitary transform and U is performing a quantum computation. Examples are quantum adders and subunits of quantum modulo adders. In this paper we show, both analytically and numerically, that if, in analogy to spin echoes, F and F-1 can be implemented symmetrically when executing Shor's algorithm on actual, imperfect quantum hardware, such that F and F-1 have the same hardware errors, a symmetry boost in the fidelity of the combined F U F-1 quantum operation results when compared to the case in which the errors in F and F-1 are independently random. Running the complete gate-by-gate implemented Shor algorithm, we show that the symmetry-induced fidelity boost can be as large as a factor 4. While most of our analytical and numerical results concern the case of over- and under-rotation of controlled rotation gates, in the numerically accessible case of Shor's algorithm with a small number of qubits, we show explicitly that the symmetry boost is robust with respect to more general types of errors. While, expectedly, additional error types reduce the symmetry boost, we show explicitly, by implementing general off-diagonal SU (N ) errors (N =2 ,4 ,8 ), that the boost factor scales like a Lorentzian in δ /σ , where σ and δ are the error strengths of the diagonal over- and underrotation errors and the off-diagonal SU (N ) errors, respectively. The Lorentzian shape also shows that, while the boost factor may become small with increasing δ , it declines slowly (essentially like a power law) and is never completely erased. We also investigate the effect of diagonal nonunitary errors, which, in analogy to unitary errors, reduce but never erase the symmetry boost. Going beyond the case of small quantum processors, we present analytical scaling results that show that the symmetry boost persists in the practically interesting case of a large number of qubits. We illustrate this result

Super-No-Scale F-SU(5): A dynamic determination of M{sub 1/2} and tan{beta}

Energy Technology Data Exchange (ETDEWEB)

Li Tianjun, E-mail: junlt@physics.tamu.edu [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); Maxin, James A., E-mail: jmaxin@physics.tamu.edu [George P. and Cynthia W. Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States); Nanopoulos, Dimitri V., E-mail: dimitri@physics.tamu.edu [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); Walker, Joel W., E-mail: jwalker@shsu.edu [Department of Physics, Sam Houston State University, Huntsville, TX 77341 (United States)

2011-09-20

We study the Higgs potential in No-Scale F-SU(5), a model built on the tripodal foundations of the F-lipped SU(5)xU(1){sub X} Grand Unified Theory, extra F-theory derived TeV scale vector-like particle multiplets, and the high scale boundary conditions of no-scale supergravity. V{sub min}, the minimum of the potential following radiative electroweak symmetry breaking, is a function at fixed Z-boson mass of the universal gaugino boundary mass M{sub 1/2} and tan{beta}, the ratio of Higgs vacuum expectation values. The so-scale nullification of the bilinear Higgs soft term B{sub {mu}} at the boundary reduces V{sub min}(M{sub 1/2}) to a one-dimensional dependency, which may be secondarily minimized. This 'Super-No-Scale' condition dynamically fixes tan{beta} and M{sub 1/2} at the local minimum minimorum of V{sub min}. Fantastically, the walls of this theoretically established secondary potential coalesce in descent to a striking concurrency with the previously phenomenologically favored 'Golden Point' and 'Golden Strip'.

Enlarged symmetry algebras of spin chains, loop models, and S-matrices

International Nuclear Information System (INIS)

Read, N.; Saleur, H.

2007-01-01

The symmetry algebras of certain families of quantum spin chains are considered in detail. The simplest examples possess m states per site (m>=2), with nearest-neighbor interactions with U(m) symmetry, under which the sites transform alternately along the chain in the fundamental m and its conjugate representation m-bar. We find that these spin chains, even with arbitrary coefficients of these interactions, have a symmetry algebra A m much larger than U(m), which implies that the energy eigenstates fall into sectors that for open chains (i.e., free boundary conditions) can be labeled by j=0,1,...,L, for the 2L-site chain such that the degeneracies of all eigenvalues in the jth sector are generically the same and increase rapidly with j. For large j, these degeneracies are much larger than those that would be expected from the U(m) symmetry alone. The enlarged symmetry algebra A m (2L) consists of operators that commute in this space of states with the Temperley-Lieb algebra that is generated by the set of nearest-neighbor interaction terms; A m (2L) is not a Yangian. There are similar results for supersymmetric chains with gl(m+n|n) symmetry of nearest-neighbor interactions, and a richer representation structure for closed chains (i.e., periodic boundary conditions). The symmetries also apply to the loop models that can be obtained from the spin chains in a spacetime or transfer matrix picture. In the loop language, the symmetries arise because the loops cannot cross. We further define tensor products of representations (for the open chains) by joining chains end to end. The fusion rules for decomposing the tensor product of representations labeled j 1 and j 2 take the same form as the Clebsch-Gordan series for SU(2). This and other structures turn the symmetry algebra A m into a ribbon Hopf algebra, and we show that this is 'Morita equivalent' to the quantum group U q (sl 2 ) for m=q+q -1 . The open-chain results are extended to the cases vertical bar m vertical

2-surface twistors, embeddings and symmetries

International Nuclear Information System (INIS)

Jeffryes, B.P.

1987-01-01

2-Surface twistor space was introduced in connection with a proposal for a quasi-local definition of mass and angular momentum within general relativity. Properties of the 2-surface twistor space are related to the possibilities for embedding the 2-surface in real and complex conformally flat spaces. The additional properties of the twistor space resulting from symmetries of the 2-surface are discussed, with particular detail on axisymmetric 2-surfaces. (author)

Contraction of graded su(2) algebra

International Nuclear Information System (INIS)

Patra, M.K.; Tripathy, K.C.

1989-01-01

The Inoenu-Wigner contraction scheme is extended to Lie superalgebras. The structure and representations of extended BRS algebra are obtained from contraction of the graded su(2) algebra. From cohomological consideration, we demonstrate that the graded su(2) algebra is the only superalgebra which, on contraction, yields the full BRS algebra. (orig.)

Chiral symmetry breaking and the spin content of the {rho} and {rho}{sup '} mesons

Energy Technology Data Exchange (ETDEWEB)

Glozman, L.Ya., E-mail: leonid.glozman@uni-graz.at [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria); Lang, C.B., E-mail: christian.lang@uni-graz.at [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria); Limmer, M., E-mail: markus.limmer@uni-graz.at [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria)

2011-11-03

Using interpolators with different SU(2){sub L}xSU(2){sub R} transformation properties we study the chiral symmetry and spin contents of the {rho} and {rho}{sup '} mesons in lattice simulations with dynamical quarks. A ratio of couplings of the q-bar {gamma}{sup i}{tau}q and q-bar {sigma}{sup 0}i{tau}q interpolators to a given meson state at different resolution scales tells one about the degree of chiral symmetry breaking in the meson wave function at these scales. Using a Gaussian gauge invariant smearing of the quark fields in the interpolators, we are able to extract the chiral content of mesons up to the infrared resolution of {approx}1 fm. In the ground state {rho} meson the chiral symmetry is strongly broken with comparable contributions of both the (0,1)+(1,0) and (1/2,1/2){sub b} chiral representations with the former being the leading contribution. In contrast, in the {rho}{sup '} meson the degree of chiral symmetry breaking is manifestly smaller and the leading representation is (1/2,1/2){sub b}. Using a unitary transformation from the chiral basis to the {sup 2S+1}L{sub J} basis, we are able to define and measure the angular momentum content of mesons in the rest frame. This definition is different from the traditional one which uses parton distributions in the infinite momentum frame. The {rho} meson is practically a {sup 3}S{sub 1} state with no obvious trace of a 'spin crisis'. The {rho}{sup '} meson has a sizeable contribution of the {sup 3}D{sub 1} wave, which implies that the {rho}{sup '} meson cannot be considered as a pure radial excitation of the {rho} meson.

Entanglement properties of the two-dimensional SU(3) Affleck-Kennedy-Lieb-Tasaki state

Science.gov (United States)

Gauthé, Olivier; Poilblanc, Didier

2017-09-01

Two-dimensional (spin-2) Affleck-Kennedy-Lieb-Tasaki (AKLT) type valence bond solids on a square lattice are known to be symmetry-protected topological (SPT) gapped spin liquids [S. Takayoshi, P. Pujol, and A. Tanaka Phys. Rev. B 94, 235159 (2016), 10.1103/PhysRevB.94.235159]. Using the projected entangled pair state framework, we extend the construction of the AKLT state to the case of SU(3 ) , relevant for cold atom systems. The entanglement spectrum is shown to be described by an alternating SU(3 ) chain of "quarks" and "antiquarks", subject to exponentially decaying (with distance) Heisenberg interactions, in close similarity with its SU(2 ) analog. We discuss the SPT feature of the state.

Bifurcation in Z2-symmetry quadratic polynomial systems with delay

International Nuclear Information System (INIS)

Zhang Chunrui; Zheng Baodong

2009-01-01

Z 2 -symmetry systems are considered. Firstly the general forms of Z 2 -symmetry quadratic polynomial system are given, and then a three-dimensional Z 2 equivariant system is considered, which describes the relations of two predator species for a single prey species. Finally, the explicit formulas for determining the Fold and Hopf bifurcations are obtained by using the normal form theory and center manifold argument.

Hidden Uq (sl(2)) Uq (sl(2)) Quantum Group Symmetry in Two Dimensional Gravity

Science.gov (United States)

Cremmer, Eugène; Gervais, Jean-Loup; Schnittger, Jens

1997-02-01

In a previous paper, the quantum-group-covariant chiral vertex operators in the spin 1/2 representation were shown to act, by braiding with the other covariant primaries, as generators of the well known Uq(sl(2)) quantum group symmetry (for a single screening charge). Here, this structure is transformed to the Bloch wave/Coulomb gas operator basis, thereby establishing for the first time its quantum group symmetry properties. A Uq(sl(2)) otimes Uq(sl(2)) symmetry of a novel type emerges: The two Cartan-generator eigenvalues are specified by the choice of matrix element (Vermamodules); the two Casimir eigenvalues are equal and specified by the Virasoro weight of the vertex operator considered; the co-product is defined with a matching condition dictated by the Hilbert space structure of the operator product. This hidden symmetry possesses a novel Hopf-like structure compatible with these conditions. At roots of unity it gives the right truncation. Its (non-linear) connection with the Uq(sl(2)) previously discussed is disentangled.

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

Supervariable Approach to the Nilpotent Symmetries for a Toy Model of the Hodge Theory

International Nuclear Information System (INIS)

Malik, R. P.; Bhanja, T.; Shukla, D.

2016-01-01

We exploit the standard techniques of the supervariable approach to derive the nilpotent Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry transformations for a toy model of the Hodge theory (i.e., a rigid rotor) and provide the geometrical meaning and interpretation to them. Furthermore, we also derive the nilpotent (anti-)co-BRST symmetry transformations for this theory within the framework of the above supervariable approach. We capture the (anti-)BRST and (anti-)co-BRST invariance of the Lagrangian of our present theory within the framework of augmented supervariable formalism. We also express the (anti-)BRST and (anti-)co-BRST charges in terms of the supervariables (obtained after the application of the (dual-)horizontality conditions and (anti-)BRST and (anti-)co-BRST invariant restrictions) to provide the geometrical interpretations for their nilpotency and anticommutativity properties. The application of the dual-horizontality condition and ensuing proper (i.e., nilpotent and absolutely anticommuting) fermionic (anti-)co-BRST symmetries are completely novel results in our present investigation.

Pork consumer market in Belo Horizonte, Brazil

OpenAIRE

Faria, I.G.; Ferreira, J.M.; Garcia, S.K.

2006-01-01

Avaliou-se o comportamento do mercado consumidor de carne suína e seus derivados em Belo Horizonte. Foram entrevistados 401 consumidores, homens e mulheres, maiores de 19 anos de idade, mantendo-se a proporcionalidade observada no censo populacional. Além de sexo e faixa etária, escolaridade, ocupação e renda familiar foram levantadas para compor os fatores condicionantes da pesquisa. A carne suína in natura é consumida até três vezes por semana pela maioria da população (61,6%), em função de...

Symmetries and groups in particle physics; Symmetrien und Gruppen in der Teilchenphysik

Energy Technology Data Exchange (ETDEWEB)

Scherer, Stefan [Mainz Univ. (Germany)

2016-07-01

The aim of this book consists of a didactic introduction to the group-theoretical considerations and methods, which have led to an ever deeper understanding of the interactions of the elementary particles. The first three chapters deal primarily with the foundations of the representation theory of primarily finite groups, whereby many results are also transferable to compact Lie groups. In the third chapter we discuss the concept of Lie groups and their connection with Lie algebras. In the remaining chapter it is mainly about the application of group theory in physics. Chapter 4 deals with the groups SO(3) and SU(2), which occur in connection with the description of the angular momentum in quantum mechanics. We discuss the Wigner-Eckar theorem together with some applications. In chapter 5 we are employed to the composition properties of strongly interacting systems, so called hadrons, and discuss extensively the transformation properties of quarks with relation to the special unitary groups. The Noether theorem is generally treated in connection to the conservation laws belonging to the Galilei group and the Poincare group. We confine us in chapter 6 to internal symmetries, but explain for that extensively the application to quantum field theory. Especially an outlook on the effect of symmetries in form of so called Ward identities is granted. In chapter 7 we turn towards the gauge principle and discuss first the construction of quantum electrodynamics. In the following we generalize the gauge principle to non-Abelian groups (Yang-Mills theories) and formulate the quantum chromodynamics (QCD). Especially we take a view of ''random'' global symmetries of QCD, especially the chiral symmetry. In chapter 8 we illuminate the phenomenon of spontaneous symmetry breaking both for global and for local symmetries. In the final chapter we work out the group-theoretical structure of the Standard Model. Finally by means of the group SU(5) we take a view to

Torons, chiral symmetry breaking and U(1) problem in σ-model and gauge theories. Part 2

International Nuclear Information System (INIS)

Zhitnitskij, A.R.

1989-01-01

The main point of this work is the physical consenquences of the existence of fractional charge in the σ-models and espesially in the physically interesting theory QCD. It is shown that the corresponding fluctuations ensure spontaneous breaking of the chiral symmetry and give a nonzero contribution to the chiral condensate. Toron solution is determined on the manifold with boundary. In this case many questions arise such as: global boundary conditions, the stability of the solution, self-adjointness of Dirac operator, single-valuedness of the physical values and so on. These questions are interconnected and turn out to be self cobsistent only for the special choice of the topological number (Q=1/2 for SU(2)). It is shown that in the Dirac's spectrum of the quarks the gap between zero and the continuum is absent. 50 refs.; 10 figs

Double beta decay, neutrino physics, nuclear structure and isospin and spin-isospin symmetries

International Nuclear Information System (INIS)

Krmpotic, F.

1989-12-01

Prominent features of the double beta decay processes are reviewed. Emphasis is placed on the neutrino masses and the quasiparticle random phase approximation (GRPA). The suppression mechanism for the ββ-decay transition rates, proposed by Vogel and Zirnbauer, is found to be closely related to the restoration of SU(4) symmetry. It is suggested that the extreme sensitivity of the ββ-decay amplitude on the proton-neutron coupling is a consequence of the explicit violation of the SU(4) symmetry and therefore an artifact of the model. A prescription is given for fixing this interaction strength within the GRPA itself, which in this way acquires predicting power on both single and double β-decay lifetimes. (author) [pt

Chiral symmetry and strangeness at SIS energies

International Nuclear Information System (INIS)

Lutz, M.F.M.

2003-11-01

In this talk we review the consequences of the chiral SU(3) symmetry for strangeness propagation in nuclear matter. Objects of crucial importance are the meson-baryon scattering amplitudes obtained within the chiral coupled-channel effective field theory. Results for antikaon and hyperon-resonance spectral functions in cold nuclear matter are presented and discussed. The importance of the Σ(1385) resonance for the subthreshold antikaon production in heavy-ion reaction at SIS is pointed out. The in-medium properties of the latter together with an antikaon spectral function based on chiral SU(3) dynamics suggest a significant enhancement of the π Λ → anti Κ N reaction in nuclear matter. (orig.)

Lepton mixing predictions from Δ(6n2) family symmetry

International Nuclear Information System (INIS)

King, Stephen F.; Neder, Thomas; Stuart, Alexander J.

2013-01-01

We obtain predictions of lepton mixing parameters for direct models based on Δ(6n 2 ) family symmetry groups for arbitrarily large n in which the full Klein symmetry is identified as a subgroup of the family symmetry. After reviewing and developing the group theory associated with Δ(6n 2 ), we find many new candidates for large n able to yield reactor angle predictions within 3σ of recent global fits. We show that such Δ(6n 2 ) models with Majorana neutrinos predict trimaximal mixing with reactor angle θ 13 fixed up to a discrete choice, an oscillation phase of either zero or π and the atmospheric angle sum rules θ 23 =45°∓θ 13 /√(2), respectively, which are consistent with recent global fits and will be tested in the near future

Influences on target irradiation symmetry in CO2 laser-fusion experiments

International Nuclear Information System (INIS)

Carman, R.L.

1981-01-01

The existence of very steep density profiles and high upper shelf densities imply that the CO 2 laser deposits its energy spatially quite close to the ablation surface where calculations indicate that a high degree of symmetry must exist in order to achieve the necessary high compression ratios. Thus, energy transport provides only limited improvement in the ablative symmetry over that achieved in the irradiation symmetry. Current data suggests that a balance between radiation pressure and hydrodynamic pressure underestimates the density to which the CO 2 laser light penetrates for early times

Self-interacting dark matter and Higgs bosons in the SU(3)C x SU(3)L x U(1)N model with right-handed neutrinos

International Nuclear Information System (INIS)

Hoang Ngoc Long; Nguyen Quynh Lan

2003-05-01

We show that the SU(3) C x SU(3) L x U(1) N (3-3-1) model with right-handed neutrinos can provide candidates for self-interacting dark matter, namely they are the CP-even and odd Higgs bosons. These dark matters are stable without imposing of new symmetry and should be weak-interacting. (author)

Flavor SU(3) in hadronic B decays

International Nuclear Information System (INIS)

Dighe, A.

1998-11-01

Here we shall outline a few methods that use the flavor SU(3) symmetry in the decays of B mesons to determine the angles of the unitarity triangle and to identify the decay modes which would display a significant CP violation. (author)

Translational Symmetry Breaking and Gapping of Heavy-Quasiparticle Pocket in URu2Si2

Science.gov (United States)

Yoshida, Rikiya; Tsubota, Koji; Ishiga, Toshihiko; Sunagawa, Masanori; Sonoyama, Jyunki; Aoki, Dai; Flouquet, Jacques; Wakita, Takanori; Muraoka, Yuji; Yokoya, Takayoshi

2013-01-01

URu2Si2 is a uranium compound that exhibits a so-called ‘hidden-order’ transition at ~17.5 K. However, the order parameter of this second-order transition as well as many of its microscopic properties remain unclarified despite considerable research. One of the key questions in this regard concerns the type of spontaneous symmetry breaking occurring at the transition; although rotational symmetry breaking has been detected, it is not clear whether another type of symmetry breaking also occurs. Another key question concerns the property of Fermi-surface gapping in the momentum space. Here we address these key questions by a momentum-dependent observation of electronic states at the transition employing ultrahigh-resolution three-dimensional angle-resolved photoemission spectroscopy. Our results provide compelling evidence of the spontaneous breaking of the lattice's translational symmetry and particle-hole asymmetric gapping of a heavy quasiparticle pocket at the transition. PMID:24084937

The spontaneous breakdown of chiral symmetry in QCD

International Nuclear Information System (INIS)

Yoshida, K.

1980-02-01

It is suggested that the usual path integral representation of Euclidean vacuum amplitude (tunneling amplitude) in QCD must be supplemented by the explicit boundary condition corresponding to the spontaneous breaking of chiral SU(N) x SU(N). Adopting the trial wave function introduced by Nambu and Jona-Lasinio, one sees that such a path integral automatically breaks also the additional chiral U(1) symmetry of massless quarks. The catastrophe of semi-classical approach to QCD and 'U(1) problem' would be avoided in this way and one has, in principle, a better starting point for the self-consistent calculation

Symmetry Analysis and Exact Solutions of (2+1)-Dimensional Sawada-Kotera Equation

International Nuclear Information System (INIS)

Zhi Hongyan; Zhang Hongqing

2008-01-01

Based on the symbolic computation system Maple, the infinite-dimensional symmetry group of the (2+1)-dimensional Sawada-Kotera equation is found by the classical Lie group method and the characterization of the group properties is given. The symmetry groups are used to perform the symmetry reduction. Moreover, with Lou's direct method that is based on Lax pairs, we obtain the symmetry transformations of the Sawada-Kotera and Konopelchenko-Dubrovsky equations, respectively.

Classification of flipped SU(5) heterotic-string vacua

Energy Technology Data Exchange (ETDEWEB)

Faraggi, Alon E., E-mail: alon.faraggi@liv.ac.uk [Department of Mathematical Sciences, University of Liverpool, Liverpool L69 7ZL (United Kingdom); Rizos, John, E-mail: irizos@uoi.gr [Department of Physics, University of Ioannina, GR45110 Ioannina (Greece); Sonmez, Hasan, E-mail: Hasan.Sonmez@liv.ac.uk [Department of Mathematical Sciences, University of Liverpool, Liverpool L69 7ZL (United Kingdom)

2014-09-15

We extend the classification of free fermionic heterotic-string vacua to models in which the SO(10) GUT symmetry is reduced at the string level to the flipped SU(5) subgroup. In our classification method the set of boundary condition basis vectors is fixed and the enumeration of string vacua is obtained in terms of the Generalised GSO (GGSO) projection coefficients entering the one-loop partition function. We derive algebraic expressions for the GGSO projections for all the physical states appearing in the sectors generated by the set of basis vectors. This enables the programming of the entire spectrum analysis in a computer code. For that purpose we developed two independent codes, based on FORTRAN95 and JAVA, and all results presented are confirmed by the two independent routines. We perform a statistical sampling in the space of 2{sup 44}∼10{sup 13} flipped SU(5) vacua, and scan up to 10{sup 12} GGSO configurations. Contrary to the corresponding Pati–Salam classification results, we do not find exophobic flipped SU(5) vacua with an odd number of generations. We study the structure of exotic states appearing in the three generation models, that additionally contain a viable Higgs spectrum, and demonstrate the existence of models in which all the exotic states are confined by a hidden sector non-Abelian gauge symmetry, as well as models that may admit the racetrack mechanism.

Effective hamiltonian within the microscopic unitary nuclear model

International Nuclear Information System (INIS)

Avramenko, V.I.; Blokhin, A.L.

1989-01-01

Within the microscopic version of the unitary collective model with the horizontal mixing the effective Hamiltonian for 18 O and 18 Ne nuclei is constructed. The algebraic structure of the Hamiltonian is compared to the familiar phenomenological ones with the SU(3)-mixing terms which describe the coupled rotational and vibrational spectra. The Hamiltonian, including central nuclear and Coulomb interaction, is diagonalized on the basis of three SU(3) irreducible representations with two orbital symmetries. 32 refs.; 2 figs.; 4 tabs

Quotients of irreducible N=2 superconformal coset theories by discrete symmetries

International Nuclear Information System (INIS)

Bailin, D.; Love, A.

1990-01-01

The spectrum of massless states is studied for the irreducible N=2 superconformal coset theories when these theories are quotiented by discrete symmetries, including the effect of embedding the discrete symmetries in the gauge group. (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

Particle-hole excitations in the interacting boson model; 4, the U(5)-SU(3) coupling

CERN Document Server

De Coster, C; Heyde, Kris L G; Jolie, J; Lehmann, H; Wood, J L

1999-01-01

In the extended interacting boson model (EIBM) both particle- and hole-like bosons are incorporated to encompass multi-particle-multi-hole excitations at and near to closed shells.We apply the group theoretical concepts of the EIBM to the particular case of two coexisting systems in the same nucleus exhibiting a U(5) (for the regular configurations) and an SU(3) symmetry (for the intruder configurations).Besides the description of ``global'' symmetry aspects in terms of I-spin , also the very specific local mixing effects characteristic for the U(5)-SU(3) symmetry coupling are studied.The model is applied to the Po isotopes and a comparison with a morerealistic calculation is made.

Minimal Regge model for meson--baryon scattering: duality, SU(3) and phase-modified absorptive cuts

International Nuclear Information System (INIS)

Egli, S.E.

1975-10-01

A model is presented which incorporates economically all of the modifications to simple SU(3)-symmetric dual Regge pole theory which are required by existing data on 0 -1 / 2 + → -1 / 2 + processes. The basic assumptions are no-exotics duality, minimally broken SU(3) symmetry, and absorptive Regge cuts phase-modified by the Ringland prescription. First it is described qualitatively how these assumptions suffice for the description of all measured reactions, and then the results of a detailed fit to 1987 data points are presented for 18 different reactions. (auth)

On the SU2 unit tensor

International Nuclear Information System (INIS)

Kibler, M.; Grenet, G.

1979-07-01

The SU 2 unit tensor operators tsub(k,α) are studied. In the case where the spinor point group G* coincides with U 1 , then tsub(k α) reduces up to a constant to the Wigner-Racah-Schwinger tensor operator tsub(kqα), an operator which produces an angular momentum state. One first investigates those general properties of tsub(kα) which are independent of their realization. The tsub(kα) in terms of two pairs of boson creation and annihilation operators are realized. This leads to look at the Schwinger calculus relative to one angular momentum of two coupled angular momenta. As a by-product, a procedure is given for producing recursion relationships between SU 2 Wigner coefficients. Finally, some of the properties of the Wigner and Racah operators for an arbitrary compact group and the SU 2 coupling coefficients are studied

Split-Family SUSY, U(2)^5 Flavour Symmetry and Neutrino Physics

CERN Document Server

Jones-Pérez, Joel

2014-01-01

In split-family SUSY, one can use a U(2)^3 symmetry to protect flavour observables in the quark sector from SUSY contributions. However, attempts to extend this procedure to the lepton sector by using an analogous U(2)^5 symmetry fail to reproduce the neutrino data without introducing some form of fine-tuning. In this work, we solve this problem by shifting the U(2)^2 symmetry acting on leptons towards the second and third generations. This allows neutrino data to be reproduced without much difficulties, as well as protecting the leptonic flavour observables from SUSY. Key signatures are a $\\mu\\to e\\gamma$ branching ratio possibly observable in the near future, as well as having selectrons as the lightest sleptons.

OSp(5|4) superconformal symmetry of N=5 Chern–Simons theory

International Nuclear Information System (INIS)

Chen, Fa-Min

2013-01-01

We demonstrate that the general D=3, N=5 Chern–Simons matter theory possesses a full OSp(5|4) superconformal symmetry, and construct the corresponding superconformal currents. The closure of the superconformal algebra is verified in detail. We also show that the conserved OSp(6|4) superconformal currents in the general N=6 theory can be obtained as special cases of the OSp(5|4) currents by enhancing the R-symmetry of the N=5 theory from USp(4) to SU(4)

Comments on global symmetries, anomalies, and duality in (2+1)d

Energy Technology Data Exchange (ETDEWEB)

Benini, Francesco [School of Natural Sciences, Institute for Advanced Study,Princeton, NJ 08540 (United States); SISSA & INFN,via Bonomea 265, 34136 Trieste (Italy); Hsin, Po-Shen [Department of Physics, Princeton University,Princeton, NJ 08544 (United States); Seiberg, Nathan [School of Natural Sciences, Institute for Advanced Study,Princeton, NJ 08540 (United States)

2017-04-21

We analyze in detail the global symmetries of various (2+1)d quantum field theories and couple them to classical background gauge fields. A proper identification of the global symmetries allows us to consider all non-trivial bundles of those background fields, thus finding more subtle observables. The global symmetries exhibit interesting ’t Hooft anomalies. These allow us to constrain the IR behavior of the theories and provide powerful constraints on conjectured dualities.

Dynamical symmetry as a tool to understanding properties of supersymmetric partner potentials. Example of so(2,1) symmetry

International Nuclear Information System (INIS)

Wehrhahn, R.F.; Cooper, I.L.

1992-05-01

Analysis of the dynamical symmetry of a system is used to predict properties arising from its supersymmetric quantum mechanical treatment. Two applications of the so(2,1) algebra, the Coulomb potential and Morse oscillator potential which display different structure with respect to the dynamical symmetry, are studied. This difference is shown to be responsible for the behaviour of the respective supersymmetric partner potentials. (orig.)

Horizontal vortex single chamber hydroturbine

Directory of Open Access Journals (Sweden)

Sergio Antonio Zarate-Orrego

2016-01-01

Full Text Available Se evaluó una máquina con alta resistencia de forma para extraer energía de una quebrada, río o corriente marina, y generar electricidad. Sin instrumentos adecuados, la investigación fue cualitativa. Se supuso que si aun así funcionaba, su comportamiento podía mejorar suavizándose la forma. El aparato tiene una tobera semi-convergente de paredes planas, una cámara de vórtice cilíndrica y un rodete. Capta agua por su sección mayor y la descarga tangencialmente por su sección menor en la cámara de vórtice; ésta tiene un orificio en una de sus paredes laterales. Así forma un vórtice horizontal que hace girar un rodete cuyo eje acciona un generador eléctrico. El trabajo experimental realizado mostró que sí es posible producir energía eléctrica con este dispositivo pese a las condiciones adversas en que se ensayó.

Coherent non-linear optical response in SU(2) symmetry broken single and bilayer graphene

International Nuclear Information System (INIS)

Kumar, Vipin; Enamullah,; Kumar, Upendra; Setlur, Girish S.

2014-01-01

Anomalous Rabi oscillations in single and bilayer graphene, in the absence of time-reversal symmetry, are described. The main findings of this work are that intra-layer sublattice space asymmetry has a remarkable effect on anomalous Rabi frequency in single and bilayer graphene, namely it is offset by the asymmetry parameter. However, the conventional Rabi frequency is nearly independent of the asymmetry parameter. Inter-layer asymmetry in bilayer graphene has an even more significant effect on anomalous Rabi frequency. When inter-layer asymmetry is taken into account, the anomalous Rabi frequency versus the external field goes through a minimum. The induced current in the frequency domain in these systems shows a finite threshold behavior even for vanishingly small applied fields. These offset oscillations are attributable to the asymmetry parameter in these systems, and are observable only for weak applied fields. For stronger applied fields these phenomena tend towards those without asymmetry

Los 'Horizontes poéticos' (1881) de Francisca Sarasate

OpenAIRE

Mata-Induráin, C. (Carlos)

1999-01-01

Francisca Sarasate supone una excepción notable en el área de las letras navarras, por la escasez de mujeres en el ámbito literario. Cultivó, entre otros, la novela, el cuento, el teatro y la poesía. Destaca su obra 'Horizontes poéticos'. ------------------ Francisca Sarasate is a notable exception in the area of the letters of Navarra, by the scarcity of women in the literary field. She cultivated the novel, short stories, drama and poetry. She wrote, among others, 'Horizontes poéticos'....

Gelfand-Dickey algebra and higher spin symmetries on T2

International Nuclear Information System (INIS)

Sedra, M.B.

2007-08-01

We focus in this work to renew the interest in higher conformal spins symmetries and their relations to quantum field theories and integrable models. We consider the extension of the conformal Frappat et al. symmetries containing the Virasoro and the Antoniadis et al. algebras as particular cases describing geometrically special diffeomorphisms of the two dimensional torus T 2 . We show in a consistent way, and explicitly, how one can extract these generalized symmetries from the Gelfand-Dickey algebra. The link with Liouville and Toda conformal field theories is established and various important properties are discussed. (author)

Symmetries and nuclei

International Nuclear Information System (INIS)

Henley, E.M.

1987-01-01

Nuclei are very useful for testing symmetries, and for studies of symmetry breaking. This thesis is illustrated for two improper space-time transformations, parity and time-reversal and for one internal symmetry: charge symmetry and independence. Recent progress and present interest is reviewed. 23 refs., 8 figs., 2 tabs

Vector coherent state representations of SO5 contains SU2 + SU2 contains U1 + U1 and SO5 contains U1 + U1

International Nuclear Information System (INIS)

Pan Feng

1991-01-01

VCS representations of SO 5 contains SU 2 + SU 2 contains U 1 + U 1 and SO 5 contains U 1 + U 1 are discussed. Reduced matrix elements for SO 5 contains SU 2 + SU 2 are derived. The multiplicity of a weight for SO 5 is determined by using the K-matrix technique

Exact scattering in the SU(n) supersymmetric principal chiral model

CERN Document Server

Evans, J M; Evans, Jonathan M; Hollowood, Timothy J

1997-01-01

The complete spectrum of states in the supersymmetric principal chiral model based on SU(n) is conjectured, and an exact factorizable S-matrix is proposed to describe scattering amongst these states. The SU(n)_L*SU(n)_R symmetry of the lagrangian is manifest in the S-matrix construction. The supersymmetries, on the other hand, are incorporated in the guise of spin-1/2 charges acting on a set of RSOS kinks associated with su(n) at level n. To test the proposed S-matrix, calculations of the change in the ground-state energy in the presence of a coupling to a background charge are carried out. The results derived from the lagrangian using perturbation theory and from the S-matrix using the TBA are found to be in complete agreement for a variety of background charges which pick out, in turn, the highest weight states in each of the fundamental representations of SU(n). In particular, these methods rule out the possibility of additional CDD factors in the S-matrix. Comparison of the expressions found for the free-...

Top quark asymmetry from a non-Abelian horizontal symmetry

CERN Document Server

Jung, Sunghoon; Wells, James D

2011-01-01

Motivated by the persistence of a large measured top quark forward-backward asymmetry at the Tevatron, we examine a model of non-Abelian flavor gauge symmetry. The exchange of the gauge bosons in the $t$-channel can give a large $\\Afb$ due to the forward Rutherford scattering peak. We address generic constraints on non-Abelian $t$-channel physics models including flavor diagonal resonances and potentially dangerous contributions to inclusive top pair cross sections. We caution on the general difficulty of comparing theoretical predictions for top quark signals to the existing experimental results due to potentially important acceptance effects. The first signature at the Large Hadron Collider can be a large inclusive top pair cross section, or like-sign dilepton events, although the latter signal is much smaller than in Abelian models. Deviations of the invariant mass distributions at the LHC will also be promising signatures. A more direct consistency check of the Tevatron asymmetry through the LHC asymmetry...

A separate SU(2) for the third family: Topflavor

International Nuclear Information System (INIS)

Muller, D.J.; Nandi, S.; Univ. of Texas, Austin, TX

1996-01-01

The authors consider the extended electroweak gauge group SU(2) 1 xSU(2) x xU(1) Y where the first and second families of fermions couple to SU(2) 1 while the third family couples to SU(2) 2 . Bounds based on precision electroweak observables and heavy gauge boson searches are placed on the new parameters of the theory. The extra gauge bosons can be as light as about a TeV and can be discovered at future colliders such as the NLC and LHC for a wide range of the parameter space. FCNC interactions are also considered

Random SU(2) invariant tensors

Science.gov (United States)

Li, Youning; Han, Muxin; Ruan, Dong; Zeng, Bei

2018-04-01

SU(2) invariant tensors are states in the (local) SU(2) tensor product representation but invariant under the global group action. They are of importance in the study of loop quantum gravity. A random tensor is an ensemble of tensor states. An average over the ensemble is carried out when computing any physical quantities. The random tensor exhibits a phenomenon known as ‘concentration of measure’, which states that for any bipartition the average value of entanglement entropy of its reduced density matrix is asymptotically the maximal possible as the local dimensions go to infinity. We show that this phenomenon is also true when the average is over the SU(2) invariant subspace instead of the entire space for rank-n tensors in general. It is shown in our earlier work Li et al (2017 New J. Phys. 19 063029) that the subleading correction of the entanglement entropy has a mild logarithmic divergence when n  =  4. In this paper, we show that for n  >  4 the subleading correction is not divergent but a finite number. In some special situation, the number could be even smaller than 1/2, which is the subleading correction of random state over the entire Hilbert space of tensors.

Flipped SU(5) from manifold compactification of the ten-dimensional heterotic string

Energy Technology Data Exchange (ETDEWEB)

Campbell, B.A.; Ellis, J.; Hagelin, J.S.; Ticciati, R.; Nanopoulos, D.V.

1987-11-19

We show that a recently proposed flipped SU(5) x U(1) GUT cannot be obtained from a conventional SO(10) GUT, nor from the heterotic string by Hosotani gauge symmetry breaking of E/sub 6/ on a manifold with (2,2) world-sheet supersymmetry. It can in principle be obtained by Hosotani gauge symmetry breaking of SO(10) on a manifold with (1,2) world-sheet supersymmetry. We identify the topological conditions under which the required chiral matter generations, Higgs multiplets, and gauge singlet fields can be light. In particular we show that non-perturbative world-sheet instanton effects neither destabilize the manifold nor give masses to the gauge singlets. The required Yukawa couplings are not forbidden by any known selection rules.

SU(2) with fundamental fermions and scalars

Science.gov (United States)

Hansen, Martin; Janowski, Tadeusz; Pica, Claudio; Toniato, Arianna

2018-03-01

We present preliminary results on the lattice simulation of an SU(2) gauge theory with two fermion flavors and one strongly interacting scalar field, all in the fundamental representation of SU(2). The motivation for this study comes from the recent proposal of "fundamental" partial compositeness models featuring strongly interacting scalar fields in addition to fermions. Here we describe the lattice setup for our study of this class of models and a first exploration of the lattice phase diagram. In particular we then investigate how the presence of a strongly coupled scalar field affects the properties of light meson resonances previously obtained for the SU(2) model. Preprint: CP3-Origins-2017-047 DNRF90

Heterotic String/F-theory Duality from Mirror Symmetry

CERN Document Server

Berglund, Per

1998-01-01

We use local mirror symmetry in type IIA string compactifications on Calabi-Yau n+1 folds $X_{n+1}$ to construct vector bundles on (possibly singular) elliptically fibered Calabi-Yau n-folds Z_n. The interpretation of these data as valid classical solutions of the heterotic string compactified on Z_n proves F-theory/heterotic duality at the classical level. Toric geometry is used to establish a systematic dictionary that assigns to each given toric n+1-fold $X_{n+1}$ a toric n fold Z_n together with a specific family of sheafs on it. This allows for a systematic construction of phenomenologically interesting d=4 N=1 heterotic vacua, e.g. on deformations of the tangent bundle, with grand unified and SU(3)\\times SU(2) gauge groups. As another application we find non-perturbative gauge enhancements of the heterotic string on singular Calabi-Yau manifolds and new non-perturbative dualities relating heterotic compactifications on different manifolds.

Quantum SU(2|1) supersymmetric Calogero-Moser spinning systems

Science.gov (United States)

Fedoruk, Sergey; Ivanov, Evgeny; Lechtenfeld, Olaf; Sidorov, Stepan

2018-04-01

SU(2|1) supersymmetric multi-particle quantum mechanics with additional semi-dynamical spin degrees of freedom is considered. In particular, we provide an N=4 supersymmetrization of the quantum U(2) spin Calogero-Moser model, with an intrinsic mass parameter coming from the centrally-extended superalgebra \\widehat{su}(2\\Big|1) . The full system admits an SU(2|1) covariant separation into the center-of-mass sector and the quotient. We derive explicit expressions for the classical and quantum SU(2|1) generators in both sectors as well as for the total system, and we determine the relevant energy spectra, degeneracies, and the sets of physical states.

Using Lie Symmetry Analysis to Solve a Problem That Models Mass Transfer from a Horizontal Flat Plate

Directory of Open Access Journals (Sweden)

W. Sinkala

2012-01-01

Full Text Available We use Lie symmetry analysis to solve a boundary value problem that arises in chemical engineering, namely, mass transfer during the contact of a solid slab with an overhead flowing fluid. This problem was earlier tackled using Adomian decomposition method (Fatoorehchi and Abolghasemi 2011, leading to the Adomian series form of solution. It turns out that the application of Lie group analysis yields an elegant form of the solution. After introducing the governing mathematical model and some preliminaries of Lie symmetry analysis, we compute the Lie point symmetries admitted by the governing equation and use these to construct the desired solution as an invariant solution.

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

El Sistema de información en la propiedad horizontal y su relación con los procesos contables

Directory of Open Access Journals (Sweden)

Omar Javier Solano Rodríguez

2008-01-01

Full Text Available Los ambientes computacionales con los últimos desarrollos tecnológicos permitirán cambios fundamentales en las estructuras contables y operativas de los edificios y conjuntos residenciales sometidos al régimen de propiedad horizontal y de las organizaciones en general. En el campo de los sistemas de información los cambios serán trascendentales. El presente artículo ilustra un panorama general del sistema de información y su interrelación con los procesos contables; se identifica la estructura básica del procesamiento electrónico de datos (PED, e incluye sus características; proporcionando al lector la relación entre los procesos contables automatizados con los controles a aplicar. Para concluir presentando un enfoque genérico sobre el apoyo que puede y debe brindar el control interno informático, en la cual sus procesos contables se encuentran automatizados.

Dirac dark matter and b →s ℓ+ℓ- with U(1) gauge symmetry

Science.gov (United States)

Celis, Alejandro; Feng, Wan-Zhe; Vollmann, Martin

2017-02-01

We revisit the possibility of a Dirac fermion dark matter candidate in the light of current b →s ℓ+ℓ- anomalies by investigating a minimal extension of the Standard Model with a horizontal U(1 ) ' local symmetry. Dark matter stability is protected by a remnant Z2 symmetry arising after spontaneous symmetry breaking of U(1 ) '. The associated Z' gauge boson can accommodate current hints of new physics in b →s ℓ+ℓ- decays, and acts as a vector portal between dark matter and the visible sector. We find that the model is severely constrained by a combination of precision measurements at flavor factories, LHC searches for dilepton resonances, as well as direct and indirect dark matter searches. Despite this, viable regions of the parameter space accommodating the observed dark matter relic abundance and the b →s ℓ+ℓ-anomalies still persist for dark matter and Z ' masses in the TeV range.

Denominator function for canonical SU(3) tensor operators

International Nuclear Information System (INIS)

Biedenharn, L.C.; Lohe, M.A.; Louck, J.D.

1985-01-01

The definition of a canonical unit SU(3) tensor operator is given in terms of its characteristic null space as determined by group-theoretic properties of the intertwining number. This definition is shown to imply the canonical splitting conditions used in earlier work for the explicit and unique (up to +- phases) construction of all SU(3) WCG coefficients (Wigner--Clebsch--Gordan). Using this construction, an explicit SU(3)-invariant denominator function characterizing completely the canonically defined WCG coefficients is obtained. It is shown that this denominator function (squared) is a product of linear factors which may be obtained explicitly from the characteristic null space times a ratio of polynomials. These polynomials, denoted G/sup t//sub q/, are defined over three (shift) parameters and three barycentric coordinates. The properties of these polynomials (hence, of the corresponding invariant denominator function) are developed in detail: These include a derivation of their degree, symmetries, and zeros. The symmetries are those induced on the shift parameters and barycentric coordinates by the transformations of a 3 x 3 array under row interchange, column interchange, and transposition (the group of 72 operations leaving a 3 x 3 determinant invariant). Remarkably, the zeros of the general G/sup t//sub q/ polynomial are in position and multiplicity exactly those of the SU(3) weight space associated with irreducible representation [q-1,t-1,0]. The results obtained are an essential step in the derivation of a fully explicit and comprehensible algebraic expression for all SU(3) WCG coefficients

Neutrino magnetic moment in a theory with lepton flavor symmetry

International Nuclear Information System (INIS)

Stephanov, M.A.

1987-01-01

A model for generating the neutrino magnetic moment of the order of 10 -10 μ B is proposed, which is based on the SU(3) lepton flavor symmetry. In such a way one can avoid the flavor changing processes. The experimental constraints on the constants of the model are considered

A quest for symmetry selected works of Bunji Sakita

CERN Document Server

Wadia, Spenta R; Kikkawa, Keiji

1999-01-01

This important book contains selected research papers of Prof Bunji Sakita. Included are his pioneering papers on SU(6) symmetry, strong coupling theory, string theory, supersymmetry and the method of collective coordinates. There is also a vivid personal account of his journey in physics. The book brings to light some of the key concepts of modern high energy physics.

Semileptonic B-meson decays in SU(3)

International Nuclear Information System (INIS)

Li Zuohong; Hou Yunzhi

1994-01-01

Based on the SU(3) approximate symmetry in the strong interaction three-body and four-body semileptonic B-meson decays are analyzed. Relations between decay rates are derived. Some of these relations may provide information on the nature of various competing dynamical effects that can occur in semileptonic B-meson decays

SU(3) breaking and the pseudo-scalar spectrum in multi-taste QCD

Energy Technology Data Exchange (ETDEWEB)

Creutz, Michael

2017-06-18

Using the Sigma model to explore the lowest order pseudo-scalar spectrum with SU(3) breaking, this talk considers an additional exact "taste" symmetry to mimic species doubling. Rooting replicas of a valid approach such as Wilson fermions reproduces the desired physical spectrum. In contrast, extra symmetries of the rooted staggered approach leave spurious states and a flavor dependent taste multiplicity.

Experimental consequences of SU(3) symmetry in an sdg boson model

International Nuclear Information System (INIS)

Akiyama, Y.; Brentano, P. von; Gelberg, A.

1987-01-01

Energies of collective levels in 178 Hf and 234 U are compared wth predictions of the SU(3) limiz of the sdg interacting boson model. All known positive parity states of 178 Hf below 1.8 MeV (with the expection of a 0 + band) have been satisfactorily reproduced. Most of the bands in 234 U are also described by the model. However, a few predicted states have no experimental counterpart. The introduction of the g-basons strongly reduces the previously observed discrepancies between experimental B(E2)'s in 238 U and the sd-IBM calculation. (orig.)

Freedom in electroweak symmetry breaking and mass matrix of fermions in dimensional deconstruction model

International Nuclear Information System (INIS)

Nojiri, Shin'ichi; Odintsov, Sergei D.; Sugamoto, Akio

2004-01-01

There exists a freedom in a class of four-dimensional electroweak theories proposed by Arkani-Hamed et al. relying on deconstruction and Coleman-Weinberg mechanism. The freedom comes from the winding modes of the link variable (Wilson operator) connecting non-nearest neighbours in the discrete fifth dimension. Using this freedom, dynamical breaking of SU(2) gauge symmetry, mass hierarchy patterns of fermions and Cabbibo-Kobayashi-Maskawa matrix may be obtained

The spontaneous ℤ_2 breaking Twin Higgs

International Nuclear Information System (INIS)

Beauchesne, Hugues; Earl, Kevin; Grégoire, Thomas

2016-01-01

The Twin Higgs model seeks to address the little hierarchy problem by making the Higgs a pseudo-Goldstone of a global SU(4) symmetry that is spontaneously broken to SU(3). Gauge and Yukawa couplings, which explicitly break SU(4), enjoy a discrete ℤ_2 symmetry that accidentally maintains SU(4) at the quadratic level and therefore keeps the Higgs light. Contrary to most beyond the Standard Model theories, the quadratically divergent corrections to the Higgs mass are cancelled by a mirror sector, which is uncharged under the Standard Model groups. However, the Twin Higgs with an exact ℤ_2 symmetry leads to equal vevs in the Standard Model and mirror sectors, which is phenomenologically unviable. An explicit ℤ_2 breaking potential must then be introduced and tuned against the SU(4) breaking terms to produce a hierarchy of vevs between the two sectors. This leads to a moderate but non-negligible tuning. We propose a model to alleviate this tuning, without the need for an explicit ℤ_2 breaking sector. The model consists of two SU(4) fundamental Higgses, one whose vacuum preserves ℤ_2 and one whose vacuum breaks it. As the interactions between the two Higgses are turned on, the ℤ_2 breaking is transmitted from the broken to the unbroken sector and a small hierarchy of vevs is naturally produced. The presence of an effective tadpole and feedback between the two Higgses lead to a sizable improvement of the tuning. The resulting Higgs boson is naturally very Standard Model like.

Essential restriction on the symmetry of a unified theory for the case of massive gluons

International Nuclear Information System (INIS)

Mohapatra, N.; Pati, C.

1976-01-01

In unified gauge theories with massive 'color' gluons, the physical requirement of maintaining 'color' SU(3) as a global classification symmetry is shown to lead to the following restrictions: (i) the local unifying symmetry group must be of the form Gsub(flavor)xGsub(color); (ii) quarks are to be integer charged; (iii) the number of flavors is an integral multiple of the number of 'colors'. (Auth.)

UV completions of partial compositeness: the case for a SU(4) gauge group

International Nuclear Information System (INIS)

Ferretti, Gabriele

2014-01-01

We present a model of partial compositeness arising as the IR limit of a SU(4) gauge theory with only fermionic matter. This group is one of the most promising ones among a handful of possible choices allowing a symmetry breaking pattern incorporating custodial symmetry and a top partner candidate, while retaining asymptotic freedom. It is favored for not giving rise to lepto-quarks or Landau poles in the SM gauge couplings. The minimal UV theory consists of five hyperfermions in the anti-symmetric representation and three in the fundamental and anti-fundamental. The IR theory is centered around the coset SU(5)/SO(5), with top partners in the fundamental of SO(5), giving rise to one composite fermion of electric charge 5/3, three of charge 2/3 and one of charge −1/3. Electro-Weak symmetry breaking occurs via top-quark-driven vacuum misalignment. The top quark mass is generated via the mechanism of partial compositeness, while the remaining fermions acquire a mass via a standard quadratic coupling to the Higgs. We compute the top and bottom quark mass matrix and the Electro-Weak currents of the composite fermions. The model does not give rise to unacceptably large deviations from the SM Z→bb-bar decay width.

Quark Yukawa pattern from spontaneous breaking of flavour SU(3) 3

Science.gov (United States)

Nardi, Enrico

2015-10-01

A SU(3)Q × SU(3)u × SU(3)d invariant scalar potential breaking spontaneously the quark flavour symmetry can explain the Standard Model flavour puzzle. The approximate alignment in flavour space of the vacuum expectation values of the up and down 'Yukawa fields' results as a dynamical effect. The observed quark mixing angles, the weak CP violating phase, and hierarchical quark masses can be all reproduced at the cost of introducing additional (auxiliary) scalar multiplets, but without the need of introducing hierarchical parameters.

Radiative violation of CP-symmetry

International Nuclear Information System (INIS)

Galvan Herrera, J.B.

1990-01-01

The left-right quiral symmetry is not conserved by the Standard model. A subgroup of the standard gauge group (SU(2) L ) breaks this symmetry in a explicit way. Moreover, the standard model, if there are theree or more matter generations, violates the CP discrete symmetry. This prediction has been experimentally demonstrated correct in the Kaon anti Kaon system. In this work some possible explanations to the CP violation parameter magnitude are researched. We have studied the variation of the Kobayashi-Maskawa matrix with the energy scale. To realize this work we have developed a general method to calculate the renormalization group equations of the Kobayashi-Maskawa matrix parameters. From these equations we could also calculate the renormalization group equation of the J parameter that characterizes the CP violation. This calculus has been applied in a concrete example: a typical supersymmetric model from superstring theories. This model can be seen like a natural extension of the supersymmetric standard model. This kind of models have a gauge group bigger that the standard one more particles and new terms of the Lagrangian. We have verified that such model provides us of a correct low energy fenomenology and, moreover other results, some particle spectrums have been developed. In the elaboration of this model some conditions, that the model has to respected to be compatible with the actual fenomenology, have been studied. The most interesting results of this thesis are the develop of a general method to calculate the renormalization group equations of the Kobayashi-Maskawa matrix parameters and the develop of a new mechanism of the radiative violation. This mechanism is related with the new terms of the Lagrangian. (Author)

Thermal evolution of massive strange compact objects in a SU(3) chiral Quark Meson model

Energy Technology Data Exchange (ETDEWEB)

Zacchi, Andreas

2017-07-04

In this work, thermodynamical properties of strongly interacting matter within a chiral SU(2)- and SU(3) chiral Quark Meson model have been analysed. Both effective models describe the development of the quark masses in media via the corresponding fields through chiral symmetry, which is expected to be restored at high temperatures and/or high densities, and spontaneously broken at low temperatures and/or densities. Spontaneous and explicit chiral symmetry breaking patterns give rise to massive Goldstone bosons, which are associated with the pions. Their chiral partners, the sigma mesons, are expected to be degenerate in mass, which was what we studied and observed at large temperatures/densities. The derivation and computation of thermodynamical quantities and properties in both cases can for instance be used to study relativistic and hydrodynamic Heavy Ion Collisions and the early universe for vanishing baryon number (SU(2)-case). They are also interesting for extreme astrophysical scenarios, such as Supernova explosions and the thermal evolution of their remnants, which has been among the topics of this thesis (SU(3)-case). Inclusion of the zero point energy in the SU(2) model has been carried out separately for the meson sector and for the quark sector as well as in a combined approach, where we learned, that the quark sector is quite dominant and that the vacuum fluctuations of the meson fields have little influence on the order parameter, but affect the relativistic degrees of freedom. In the SU(3) case, the inclusion of the zero point energy in the quark sector is much more computationally complex, but, as in the SU(2) case, is also not negliable, as its influence also changes the thermodynamical quantities at finite temperatures in a nontrivial manner. Here some features of the Supernova equation of state have been studied, which look promising for further investigations for Supernovae (proto neutron stars) and also for compact star mergers. The final

Varieties of Abelian mirror symmetry on ℝℙ{sup 2}×S{sup 1}

Energy Technology Data Exchange (ETDEWEB)

Mori, Hironori [Department of Physics, Graduate School of Science, Osaka University,Toyonaka, Osaka 560-0043 (Japan); Tanaka, Akinori [iTHES Research Group, RIKEN,Wako, Saitama 351-0198 (Japan)

2016-02-15

We study 3d mirror symmetry with loop operators, Wilson loop and Vortex loop, and multi-flavor mirror symmetry through utilizing the ℝℙ{sup 2}×S{sup 1} index formula. The key identity which makes the above description work well is the mod 2 version of the Fourier analysis, and we study such structure, the S-operation in the context of a SL(2,ℤ) action on 3d SCFTs. We observed that two types of the parity conditions basically associated with gauge symmetries which we call P-type and CP-type are interchanged under mirror symmetry. We will also comment on the T-operation.

High-field Transport in Low Symmetry β-Ga2O3 Crystal

Science.gov (United States)

Ghosh, Krishnendu; Singisetti, Uttam

High-field carrier transport plays an important role in many disciplines of electronics. Conventional transport theories work well on high-symmetry materials but lacks insight as the crystal symmetry goes down. Newly emerging materials, many of which possess low symmetry, demand more rigorous treatment of charge transport. We will present a comprehensive study of high-field transport using ab initio electron-phonon interaction (EPI) elements in a full-band Monte Carlo (FBMC) algorithm. We use monoclinic β-Ga2O3 as a benchmark low-symmetry material which is also an emerging wide-bandgap semiconductor. β-Ga2O3 has a C2m space group and a 10 atom primitive cell. In this work the EPIs are calculated under density-functional perturbation theory framework. We will focus on the computational challenges arising from many phonon modes and low crystal symmetry. Significant insights will be presented on the details of energy relaxation by the hot electrons mediated by different phonon modes. We will also show the velocity-field curves of electrons in different crystal directions. The authors acknowledge the support from the National Science Foundation Grant (ECCS 1607833). The authors also acknowledge the computing support provided by the Center for Computational Research at the University at Buffalo.

SU(2) X SU(2) X U(1) basis for symmetric SO(6) representations: matrix elements of the generators

International Nuclear Information System (INIS)

Piepenbring, R.; Silvestre-Brac, B.; Szymanski, Z.

1987-01-01

Matrix elements of the group generators for the symmetric irreducible representations of SO(6) are explicitly calculated in a closed form employing thedecomposition chain SO(6) is contained in SU(2) X SU(2) X U(1) (which is different from the well known Wigner supermultiplet scheme). The relation to the Gel'fand Tsetlin method using SO(6) contained in SO(5) up to ... SO(2) is indicated. An example of a physical application is given

Generalised discrete torsion and mirror symmetry for G2 manifolds

International Nuclear Information System (INIS)

Gaberdiel, Matthias R.; Kaste, Peter

2004-01-01

A generalisation of discrete torsion is introduced in which different discrete torsion phases are considered for the different fixed points or twist fields of a twisted sector. The constraints that arise from modular invariance are analysed carefully. As an application we show how all the different resolutions of the T 7 /Z 2 3 orbifold of Joyce have an interpretation in terms of such generalised discrete torsion orbifolds. Furthermore, we show that these manifolds are pairwise identified under G 2 mirror symmetry. From a conformal field theory point of view, this mirror symmetry arises from an automorphism of the extended chiral algebra of the G 2 compactification. (author)

A SU(3) x U(1) model for electroweak interactions

International Nuclear Information System (INIS)

Pisano, F.; Pleitez, V.

1992-01-01

We consider a gauge model based on a SU(3) vector U(1) symmetry in which the lepton number is violated explicitly by charged scalar and gauge boson, including a vector field with double electric charge. (author)

FN-2HDM: Two Higgs Doublet Models with Froggatt-Nielsen symmetry

Energy Technology Data Exchange (ETDEWEB)

Dery, Avital; Nir, Yosef [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Herzl 234, Rehovot 76100 (Israel)

2017-04-03

We embed Two Higgs Doublet Models (2HDMs) in the Froggatt Nielsen (FN) framework. We find that the approximate FN symmetry predicts i) approximate Natural Flavor Conservation (NFC) of Types II or IV in the Yukawa sector, and ii) approximate Peccei-Quinn (PQ) symmetry in the scalar sector. We discuss the phenomenological consequences of these features.

Experimental consequences of SU(3) symmetry in an sdg boson model

Energy Technology Data Exchange (ETDEWEB)

Akiyama, Y.; Brentano, P. von; Gelberg, A.

1987-05-01

Energies of collective levels in /sup 178/Hf and /sup 234/U are compared wth predictions of the SU(3) limiz of the sdg interacting boson model. All known positive parity states of /sup 178/Hf below 1.8 MeV (with the expection of a 0/sup +/ band) have been satisfactorily reproduced. Most of the bands in /sup 234/U are also described by the model. However, a few predicted states have no experimental counterpart. The introduction of the g-basons strongly reduces the previously observed discrepancies between experimental B(E2)'s in /sup 238/U and the sd-IBM calculation.

Neutrino masses in the SO(10) model with intermediate stage of the symmetry breaking

International Nuclear Information System (INIS)

Svetovoj, V.B.

1982-01-01

An effect for the neutrino masses of an intermediate stage in the symmetry spontaneous breaking, different from SU(5), is investigated in some detail for the SO(1O) model. There are two possibilities depending on the composition of the Higgs sector: i) msub(ν) approximately msub(f)(Msub(W)/Msub(1)); ii) msub(ν) approximately msub(f)sub(b)/Msub(1))(M/Msub(1)), where M, M 1 and Msub) are the scales of the breaking of the original SO(10) simmetry, the intermediate symmetry, and the standard SUsub(c)(3)xSUsub(L)(2)xU(1) symmetry, respectively, and msub(f) is a typical fermion mass. It as shown that a Majorana mass of the right neutrino (νsub(R)) of a purely loop origin would result in a too large mass of the usual neutrinos, so a tree-graph contribution to the mass of νsub(R) is necessary. Numerical estimates for the neutrino masses are discussed [ru

Final-state rescattering and SU(3) symmetry breaking in B→DK and B→DK* decays

International Nuclear Information System (INIS)

Xing, Z.Z.

2003-01-01

The first observation of the anti B 0 d →D 0 anti K 0 and anti B 0 d →D 0 anti K *0 transitions by the Belle Collaboration allows us to do a complete isospin analysis of the B→DK (*) decay modes. We find that their respective isospin phase shifts are very likely to lie in the ranges 37 circle ≤(φ 1 -φ 0 ) DK ≤63 circle (or around 50 circle ) and 25 circle ≤(φ 1 -φ 0 ) DK * ≤50 circle (or around 35 circle ), although the possibility (φ 1 -φ 0 ) DK = (φ 1 -φ 0 ) DK * = 0 circle cannot be ruled out at present. Thus significant final-state rescattering effects possibly exist in such exclusive vertical stroke ΔB vertical stroke = vertical stroke ΔC vertical stroke = vertical stroke ΔS vertical stroke =1 processes. We determine the spectator and color-suppressed spectator quark-diagram amplitudes of the B→DK and B→DK * decays, and compare them with the corresponding quark-diagram amplitudes of the B→Dπ and B→Dρ decays. The effects of SU(3) flavor symmetry breaking are in most cases understandable in the factorization approximation, which works for the individual isospin amplitudes. Very instructive predictions are also obtained for the branching fractions of rare anti B 0 d → anti D 0 anti K (*)0 , B - u → anti D 0 K (*)- and B - u →D - anti K (*)0 transitions. (orig.)

Electromagnetic properties in {sup 160-170}Dy nuclei. A microscopic description by the pseudo-SU(3) shell model

Energy Technology Data Exchange (ETDEWEB)

Vargas, Carlos E.; Bagatella-Flores, Norma [Universidad Veracruzana, Facultad de Fisica, Veracruz (Mexico); Velazquez, Victor [Universidad Nacional Autonoma de Mexico, Facultad de Ciencias, Mexico D.F. (Mexico); Lerma-Hernandez, Sergio [Universidad Veracruzana, Facultad de Fisica, Veracruz (Mexico); Universidad Nacional Autonoma de Mexico, Instituto de Ciencias Nucleares, Mexico D.F. (Mexico)

2017-04-15

The large collectivity observed in the rare-earth region of the nuclear landscape is well known. The microscopic studies are difficult to perform in this region due to the enormous size of the valence spaces, a problem that can be avoided by means of the use of symmetry-based models. Here we present calculations for electromagnetic properties of {sup 160-170}Dy nuclei within the pseudo-SU(3) scheme. The model Hamiltonian includes the preserving symmetry Q.Q term and the symmetry-breaking Nilsson and pairing terms, systematically parametrized for all members of the chain. The model is used to calculate B(E2) and B(M1) inter-band transition strengths between the ground state, γ and β-bands. In addition, we present results for quadrupole moments and g factors in these rotational bands. The results show that the pseudo-SU(3) shell model is a powerful microscopic theory for a description of electromagnetic properties of states in the normal parity sector in heavy deformed nuclei. (orig.)

Recovery of Stokes waves from velocity measurements on an axis of symmetry

International Nuclear Information System (INIS)

Matioc, Bogdan-Vasile

2015-01-01

We provide a new method to recover the profile of Stokes waves, and more generally of waves with smooth vorticity, from measurements of the horizontal velocity component on a vertical axis of symmetry of the wave surface. Although we consider periodic waves only, the extension to solitary waves is straightforward. (paper)

Anomaly-free gauged R-symmetry in local supersymmetry

International Nuclear Information System (INIS)

Chamseddine, A.H.; Dreiner, H.

1996-01-01

We discuss local R-symmetry as a potentially powerful new model building tool. We first review and clarify that a U(1) R-symmetry can only be gauged in local and not in global supersymmetry. We determine the anomaly-cancellation conditions for the gauged R-symmetry. For the standard superpotential these equations have no solution, independently of how many Standard Model singlets are added to the model. There is also no solution when we increase the number of families and the number of pairs of Higgs doublets. When the Green-Schwarz mechanism is employed to cancel the anomalies, solutions only exist for a large number of singlets. We find many anomaly-free family-independent models with an extra SU(3) c octet chiral superfield. We consider in detail the conditions for an anomaly-free family-dependent U(1) R and find solutions with one, two, three and four extra singlets. Only with three and four extra singlets do we naturally obtain sfermion masses of the order of the weak scale. For these solutions we consider the spontaneous breaking of supersymmetry and the R-symmetry in the context of local supersymmetry. In general the U(1) R gauge group is broken at or close to the Planck scale. We consider the effects of the R-symmetry on baryon- and lepton-number violation in supersymmetry. There is no logical connection between a conserved R-symmetry and a conserved R-parity. For conserved R-symmetry we have models for all possibilities of conserved or broken R-parity. Most models predict dominant effects which could be observed at HERA. (orig.)

Relationship between harmonic analysis on SU(2) and on SL(2,C)/SU(2)

International Nuclear Information System (INIS)

Healy, D.M. Jr.

1986-01-01

A topic of interest in harmonic analysis is the comparison of Fourier transforms on compact and noncompact spaces. The Poisson summation formula provides a classical example of this idea by providing an explicit relationship between harmonic analysis on the real line R and on the circle S 1 . This dissertation provides a new geometric proof of this formula, and then generalizes this approach to obtain a relationship between Fourier transforms on Upsilon, the space of positive matrices in SL(2,C), and Fourier transforms on SU(2)

Control of spin-orbit torques through crystal symmetry in WTe2/ferromagnet bilayers

Science.gov (United States)

MacNeill, D.; Stiehl, G. M.; Guimaraes, M. H. D.; Buhrman, R. A.; Park, J.; Ralph, D. C.

2017-03-01

Recent discoveries regarding current-induced spin-orbit torques produced by heavy-metal/ferromagnet and topological-insulator/ferromagnet bilayers provide the potential for dramatically improved efficiency in the manipulation of magnetic devices. However, in experiments performed to date, spin-orbit torques have an important limitation--the component of torque that can compensate magnetic damping is required by symmetry to lie within the device plane. This means that spin-orbit torques can drive the most current-efficient type of magnetic reversal (antidamping switching) only for magnetic devices with in-plane anisotropy, not the devices with perpendicular magnetic anisotropy that are needed for high-density applications. Here we show experimentally that this state of affairs is not fundamental, but rather one can change the allowed symmetries of spin-orbit torques in spin-source/ferromagnet bilayer devices by using a spin-source material with low crystalline symmetry. We use WTe2, a transition-metal dichalcogenide whose surface crystal structure has only one mirror plane and no two-fold rotational invariance. Consistent with these symmetries, we generate an out-of-plane antidamping torque when current is applied along a low-symmetry axis of WTe2/Permalloy bilayers, but not when current is applied along a high-symmetry axis. Controlling spin-orbit torques by crystal symmetries in multilayer samples provides a new strategy for optimizing future magnetic technologies.

Symmetry and Phase Transitions in Nuclei

International Nuclear Information System (INIS)

Iachello, F.

2009-01-01

Phase transitions in nuclei have received considerable attention in recent years, especially after the discovery that, contrary to expectations, systems at the critical point of a phase transition display a simple structure. In this talk, quantum phase transitions (QPT), i.e. phase transitions that occur as a function of a coupling constant that appears in the quantum Hamiltonian, H, describing the system, will be reviewed and experimental evidence for their occurrence in nuclei will be presented. The phase transitions discussed in the talk will be shape phase transitions. Different shapes have different symmetries, classified by the dynamic symmetries of the Interacting Boson Model, U(5), SU(3) and SO(6). Very recently, the concept of Quantum Phase Transitions has been extended to Excited State Quantum Phase Transitions (ESQPT). This extension will be discussed and some evidence for incipient ESQPT in nuclei will be presented. Systems at the critical point of a phase transition are called 'critical systems'. Approximate analytic formulas for energy spectra and other properties of 'critical nuclei', in particular for nuclei at the critical point of the second order U(5)-SO(6) transition, called E(5), and along the line of first order U(5)-SU(3) transitions, called X(5), will be presented. Experimental evidence for 'critical nuclei' will be also shown. Finally, the microscopic derivation of shape phase transitions in nuclei within the framework of density functional methods will be briefly discussed.(author)

Nuclear lattice simulations using symmetry-sign extrapolation

Energy Technology Data Exchange (ETDEWEB)

Laehde, Timo A.; Luu, Thomas [Forschungszentrum Juelich, Institute for Advanced Simulation, Institut fuer Kernphysik, and Juelich Center for Hadron Physics, Juelich (Germany); Lee, Dean [North Carolina State University, Department of Physics, Raleigh, NC (United States); Meissner, Ulf G. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Institut fuer Kernphysik, and Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, JARA - High Performance Computing, Juelich (Germany); Epelbaum, Evgeny; Krebs, Hermann [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Bochum (Germany); Rupak, Gautam [Mississippi State University, Department of Physics and Astronomy, Mississippi State, MS (United States)

2015-07-15

Projection Monte Carlo calculations of lattice Chiral Effective Field Theory suffer from sign oscillations to a varying degree dependent on the number of protons and neutrons. Hence, such studies have hitherto been concentrated on nuclei with equal numbers of protons and neutrons, and especially on the alpha nuclei where the sign oscillations are smallest. Here, we introduce the ''symmetry-sign extrapolation'' method, which allows us to use the approximate Wigner SU(4) symmetry of the nuclear interaction to systematically extend the Projection Monte Carlo calculations to nuclear systems where the sign problem is severe. We benchmark this method by calculating the ground-state energies of the {sup 12}C, {sup 6}He and {sup 6}Be nuclei, and discuss its potential for studies of neutron-rich halo nuclei and asymmetric nuclear matter. (orig.)

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.

SU(6)-strong breaking: structure functions and small momentum transfer properties of the nucleon

International Nuclear Information System (INIS)

Le Yaouanc, A.; Oliver, L.; Pene, O.; Raynal, J.C.

1975-01-01

A new approach in the study of the SU(6) symmetry breaking (in particular in deep inelastic electron-nucleon scattering) is presented. It is shown that there is a connection between deep inelastic and low momentum transfer or static properties of the nucleon, which extends much beyond the common SU(6) 56-assignments of the nucleon in both cases. This connection is provided by the realistic quark model (in which quarks are considered as real entities moving inside the hadron). Using this connection it is shown that the breaking of the prediction Fsub(2)sup(en)/Fsub(2)sup(ep)=2/3 is not truly related to chiral configuration mixings. An alternative solution, based on a true modification of the 56-assignment of the nucleon to a (56,L=0)+(70,L=0) mixing (called SU(6) strong mixing) is proposed. It is shown that the 'good' predictions of SU(6) are not much changed by this mixing. A complete description of the deep inelastic scattering including gluons and pairs is presented

Quantization of the Poisson SU(2) and its Poisson homogeneous space - the 2-sphere

International Nuclear Information System (INIS)

Sheu, A.J.L.

1991-01-01

We show that deformation quantizations of the Poisson structures on the Poisson Lie group SU(2) and its homogeneous space, the 2-sphere, are compatible with Woronowicz's deformation quantization of SU(2)'s group structure and Podles' deformation quantization of 2-sphere's homogeneous structure, respectively. So in a certain sense the multiplicativity of the Lie Poisson structure on SU(2) at the classical level is preserved under quantization. (orig.)

Canonical forms of tensor representations and spontaneous symmetry breaking

International Nuclear Information System (INIS)

Cummins, C.J.

1986-01-01

An algorithm for constructing canonical forms for any tensor representation of the classical compact Lie groups is given. This method is used to find a complete list of the symmetry breaking patterns produced by Higgs fields in the third-rank antisymmetric representations of U(n), SU(n) and SO(n) for n<=7. A simple canonical form is also given for kth-rank symmetric tensor representations. (author)

Symmetries in nuclei

International Nuclear Information System (INIS)

Arima, A.

2003-01-01

(1) There are symmetries in nature, and the concept of symmetry has been used in art and architecture. The symmetry is evaluated high in the European culture. In China, the symmetry is broken in the paintings but it is valued in the architecture. In Japan, however, the symmetry has been broken everywhere. The serious and interesting question is why these differences happens? (2) In this lecture, I reviewed from the very beginning the importance of the rotational symmetry in quantum mechanics. I am sorry to be too fundamental for specialists of nuclear physics. But for people who do not use these theories, I think that you could understand the mathematical aspects of quantum mechanics and the relation between the angular momentum and the rotational symmetry. (3) To the specialists of nuclear physics, I talked about my idea as follows: dynamical treatment of collective motions in nuclei by IBM, especially the meaning of the degeneracy observed in the rotation bands top of γ vibration and β vibration, and the origin of pseudo-spin symmetry. Namely, if there is a symmetry, a degeneracy occurs. Conversely, if there is a degeneracy, there must be a symmetry. I discussed some details of the observed evidence and this correspondence is my strong belief in physics. (author)

Towards generalized mirror symmetry for twisted connected sum G 2 manifolds

Science.gov (United States)

Braun, Andreas P.; Del Zotto, Michele

2018-03-01

We revisit our construction of mirror symmetries for compactifications of Type II superstrings on twisted connected sum G 2 manifolds. For a given G 2 manifold, we discuss evidence for the existence of mirror symmetries of two kinds: one is an autoequivalence for a given Type II superstring on a mirror pair of G 2 manifolds, the other is a duality between Type II strings with different chiralities for another pair of mirror manifolds. We clarify the role of the B-field in the construction, and check that the corresponding massless spectra are respected by the generalized mirror maps. We discuss hints towards a homological version based on BPS spectroscopy. We provide several novel examples of smooth, as well as singular, mirror G 2 backgrounds via pairs of dual projecting tops. We test our conjectures against a Joyce orbifold example, where we reproduce, using our geometrical methods, the known mirror maps that arise from the SCFT worldsheet perspective. Along the way, we discuss non-Abelian gauge symmetries, and argue for the generation of the Affleck-Harvey-Witten superpotential in the pure SYM case.

Observation of two-orbital spin-exchange interactions with ultracold SU(N)-symmetric fermions

Science.gov (United States)

Scazza, F.; Hofrichter, C.; Höfer, M.; de Groot, P. C.; Bloch, I.; Fölling, S.

2014-10-01

Spin-exchanging interactions govern the properties of strongly correlated electron systems such as many magnetic materials. When orbital degrees of freedom are present, spin exchange between different orbitals often dominates, leading to the Kondo effect, heavy fermion behaviour or magnetic ordering. Ultracold ytterbium or alkaline-earth ensembles have attracted much recent interest as model systems for these effects, with two (meta-) stable electronic configurations representing independent orbitals. We report the observation of spin-exchanging contact interactions in a two-orbital SU(N)-symmetric quantum gas realized with fermionic 173Yb. We find strong inter-orbital spin exchange by spectroscopic characterization of all interaction channels and demonstrate SU(N = 6) symmetry within our measurement precision. The spin-exchange process is also directly observed through the dynamic equilibration of spin imbalances between ensembles in separate orbitals. The realization of an SU(N)-symmetric two-orbital Hubbard Hamiltonian opens the route to quantum simulations with extended symmetries and with orbital magnetic interactions, such as the Kondo lattice model.

Coupled SU(3) models of rotational states in nuclei and quasi-dynamical symmetry

International Nuclear Information System (INIS)

Thiamova, G.; Rowe, D. J.

2007-01-01

This contribution reports a first step towards the development of a model of low-lying nuclear collective states based on the progression from weak to strong coupling of a combination of systems in multiple SU(3) irreps. The motivation for such a model comes partly from the remarkable persistence of rotational structure observed experimentally and in many model calculations. This work considers the spectra obtainable by coupling just two SU(3) irreps by means of a quadrupole-quadrupole interaction. For a particular value of this interaction, the two irreps combine to form strongly-coupled irreps while for zero interaction the weakly-coupled results are mixtures of many such strongly-coupled irreps. A notable result is the persistence of the rotor character of the low-energy states for a wide range of the interaction strength. Also notable is the fact that, for very weak interaction strengths, the energy levels of the yrast band resemble those of a vibrational sequence while the B(E2) transition strengths remain close to those of an axially symmetric rotor, as observed in many nuclei. (Author)