Broken SU(3) x SU(3) x SU(3) x SU(3) Symmetry
Freund, P. G. O.; Nambu, Y.
1964-10-01
We argue that the "Eight-fold Way" version of the SU(3) symmetry should be extended to a product of up to four separate and badly broken SU(3) groups, including the gamma{sub 5} type SU(3) symmetry. A hierarchy of subgroups (or subalgebras) are considered within this framework, and two candidates are found to be interesting in view of experimental evidence. Main features of the theory are: 1) the baryons belong to a nonet; 2) there is an octet of axial vector gauge mesons in addition to one or two octets of vector mesons; 3) pseudoscalar and scalar mesons exist as "incomplete" multiplets arising from spontaneous breakdown of symmetry.
Configuration-mixed effective SU(3) symmetries
Hess, P O; Hunyadi, M; Kvi, A G; Cseh, J
2002-01-01
The procedure of Jarrio et al. (Nucl. Phys. A 528, 409 (1991)) for the determination of the effective SU(3) symmetry of nuclear states is extended to small deformations and to oblate nuclei. Self-consistency checks are carried out both for light and for heavy nuclei. (orig.)
SU(3) × SU(3) symmetry breaking in a simple model
Wit, Bernard de
1972-01-01
A field-theoretical model, due to Lévy, is studied. It contains a triplet of quarks and a pseudoscalar and a scalar meson nonet. The original SU(3) × SU(3) symmetry is broken by terms linear in the scalar meson fields. A renormalization and regularization procedure is defined in order to remove the
Emergent SU(3) Symmetry in Random Spin-1 Chains.
Quito, V L; Hoyos, José A; Miranda, E
2015-10-16
We show that generic SU(2)-invariant random spin-1 chains have phases with an emergent SU(3) symmetry. We map out the full zero-temperature phase diagram and identify two different phases: (i) a conventional random-singlet phase (RSP) of strongly bound spin pairs [SU(3) "mesons"] and (ii) an unconventional RSP of bound SU(3) "baryons," which are formed, in the great majority, by spin trios located at random positions. The emergent SU(3) symmetry dictates that susceptibilities and correlation functions of both dipolar and quadrupolar spin operators have the same asymptotic behavior. PMID:26550897
Test of SU(3) Symmetry in Hyperon Semileptonic Decays
Pham, T N
2013-01-01
Existing analyzes of baryon semileptonic decays indicate the presence of a small SU(3) symmetry breaking in hyperon semileptonic decays, but to provide evidence for SU(3) symmetry breaking, one would need a relation similar to the Gell-Mann Okubo(GMO) baryon mass formula which is satisfied to a few percents and provides evidence for SU(3) symmetry breaking in the divergence of the vector current matrix element. In this paper, we shall present a similar GMO relation for the hyperon semileptonic decay axial vector form factors. Using these relations and the measured axial vector current to vector current form factor ratios, we show that SU(3) symmetry breaking in hyperon semileptonic decays is of 5-11%.
Test of SU(3) Symmetry in Hyperon Semileptonic Decays
Pham, T N
2014-01-01
Existing analyzes of baryon semileptonic decays indicate the presence of a small SU(3) symmetry breaking in hyperon semileptonic decays, but to provide evidence for SU(3) symmetry breaking, one would need a relation similar to the Gell-Mann--Okubo (GMO) baryon mass formula which is satisfied to a few percents, showing evidence for a small SU(3) symmetry breaking effect in the GMO mass formula. In this talk, I would like to present a similar GMO relation obtained in a recent work for hyperon semileptonic decay axial vector current matrix elements. Using these generalized GMO relations for the measured axial vector current to vector current form factor ratios, it is shown that SU(3) symmetry breaking in hyperon semileptonic decays is of $5-11%$ and confirms the validity of the Cabibbo model for hyperon semi-leptonic decays.
Dibaryonic states and the SU(3) symmetry
International Nuclear Information System (INIS)
The experimental information on dibaryon resonances with and without strangeness is analyzed, with the purpose of finding criteria for their especification as members of SU(3) multiplets formed by six quarks. The identification of a 10 multiplet with J(sup)P =1+ (spin triplet) and a 27 with J(sup)P = 2+ (spin singlet) is suggested. The conventional mass formula is used in this analysis, predicting the masses and decaying properties of several dibaryon states. The possible existence, in the 27, J(sup)P = 2+ representation, of strange states which are stable against strong interactions is discussed, and their experimental search is estimulated. Reactions in which the existence of dibaryon resonances can be detected are discussed, special attention being given to elastic K+d and K-d scattering, for which it is shown that the magnitude of the contributions of dibaryon resonances in intermediate states is of the same order of magnitude as those observed in the differential cross sections. (Author)
Emergent SU(3) symmetry in random spin-1 chains
Quito, Victor; Hoyos, Jose; Miranda, Eduardo
2015-03-01
We propose a system that realizes the idea of an ``emergent symmetry'': its low-temperature behavior has a larger symmetry than the underlying Hamiltonian. This is found in generic SU(2)-invariant random spin-1 chains, whose complete phase diagram we mapped out and characterized both analytically and numerically. The system is shown to have two different low-temperature phases with emergent SU(3) symmetry. In each of them, susceptibilities and correlation functions of both spin and quadrupolar operators are characterized by the same asymptotic exponents, which are dictated by the emergent symmetry group. Both SU(3)-symmetric phases are governed by infinitely disordered ground states. Whereas one of the ground states is formed by random singlets of pairs of spins, the other is less conventional and consists of random-singlet spin trios. This work was supported by FAPESP and CNPq.
BRST symmetries in SU(3) linear sigma model
International Nuclear Information System (INIS)
We study the BRST symmetries in the SU(3) linear sigma model which is constructed through the introduction of a novel matrix for the Goldstone boson fields satisfying geometrical constraints embedded in a SU(2) subgroup. To treat these constraints we exploit the improved Dirac quantization scheme. We also discuss phenomenological aspects in the mean field approach to this model. (orig.)
Quantum Critical Spin-2 Chain with Emergent SU(3) Symmetry
Chen, Pochung; Xue, Zhi-Long; McCulloch, I. P.; Chung, Ming-Chiang; Huang, Chao-Chun; Yip, S.-K.
2015-04-01
We study the quantum critical phase of an SU(2) symmetric spin-2 chain obtained from spin-2 bosons in a one-dimensional lattice. We obtain the scaling of the finite-size energies and entanglement entropy by exact diagonalization and density-matrix renormalization group methods. From the numerical results of the energy spectra, central charge, and scaling dimension we identify the conformal field theory describing the whole critical phase to be the SU (3 )1 Wess-Zumino-Witten model. We find that, while the Hamiltonian is only SU(2) invariant, in this critical phase there is an emergent SU(3) symmetry in the thermodynamic limit.
SU(3) symmetry and scissors mode vibrations in nuclei
Sun Yang; Bhatt, K; Guidry, M
2002-01-01
We show that a nearly perfect SU(3) symmetry emerges from an extended projected shell model. Starting from a deformed potential we construct separate bases for neutron and proton collective rotational states by exact angular momentum projection. These rotational states are then coupled by diagonalizing a residual pairing plus quadrupole interaction. The states obtained exhibit a one-to-one correspondence with an SU(3) spectrum up to high angular momentum and excitation, and their wave functions have a near-maximal overlap with the SU(3) states. They can also be classified as rotational bands built on spin-1 Planck constant phonon excitations, which correspond to a geometrical scissors mode and its generalizations. This work is a direct demonstration that numerical angular momentum projection theory extends the Elliott's original idea to heavy nuclear systems.
The Weak Mixing Angle from an SU(3) Symmetry at a TeV
Dimopoulos, Savas K; Dimopoulos, Savas; Kaplan, David Elazzar
2002-01-01
The measured values of two electroweak gauge couplings appear to obey an approximate 5% SU(3) relation. Unless this is an accident caused by fortuitous Planck-scale physics, it suggests the presence of an SU(3) symmetry near the electroweak scale. We propose this to be a local SU(3) which spontaneously ``mixes'' with SU(2) x U(1) near a TeV. Although all the particles of the standard model are SU(3)-singlets, this symmetry relates the electroweak gauge couplings and can successfully predict the weak mixing angle with a precision of a few percent. Since this mechanism operates at a TeV, it does not require an energy desert and consequently can be embedded in theories of TeV-gravity.
SU(3) Chiral Symmetry in Non-Relativistic Field Theory
Ouellette, S M
2001-01-01
Applications imposing SU(3) chiral symmetry on non-relativistic field theory are considered. The first example is a calculation of the self-energy shifts of the spin-3/2 decuplet baryons in nuclear matter, from the chiral effective Lagrangian coupling octet and decuplet baryon fields. Special attention is paid to the self-energy of the delta baryon near the saturation density of nuclear matter. We find contributions to the mass shifts from contact terms in the effective Lagrangian with coefficients of unknown value. As a second application, we formulate an effecive field theory with manifest SU(2) chiral symmetry for the interactions of K and eta mesons with pions at low energy. SU(3) chiral symmetry is imposed on the effective field theory by a matching calculation onto three-flavor chiral perturbation theory. The effective Lagrangian for the pi-K and pi-eta sectors is worked out to order Q^4; the effective Lagrangian for the K-K sector is worked out to order Q^2 with contact interactions to order Q^4. As an...
SU(3) flavour symmetry breaking and charmed states
International Nuclear Information System (INIS)
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.
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.
Rasin, A
1994-01-01
We discuss the idea of approximate flavor symmetries. Relations between approximate flavor symmetries and natural flavor conservation and democracy models is explored. Implications for neutrino physics are also discussed.
Radiative decays, nonet symmetry, and SU(3) breaking
International Nuclear Information System (INIS)
We reexamine the problem of simultaneously describing in a consistent way all radiative and leptonic decays of light mesons (V→Pγ, P→Vγ, P→γγ, V→e+e-). For this purpose, we rely on the hidden local symmetry model in both its anomalous and non-anomalous sectors. We show that the SU(3) symmetry breaking scheme proposed by Bando, Kugo and Yamawaki, supplemented with nonet symmetry breaking in the pseudoscalar sector, allows one to reach a nice agreement with all data, except for the K*± radiative decay. An extension of this breaking pattern allows one to account for this particular decay mode too. Considered together, the whole set of radiative decays provides a pseudoscalar mixing angle θP≅-11 degree and a value for θV which is ≅3 degree from that of ideal mixing. We also show that it is impossible, in a practical sense, to disentangle the effects of nonet symmetry breaking and those of glue inside the η', using only light meson decays. copyright 1999 The American Physical Society
Charged Fermion Masses and Mixing from a SU(3) Family Symmetry Model
Hernandez-Galeana, Albino
2016-01-01
Within the framework of a Beyond Standard Model (BSM) with a local $SU(3)$ family symmetry, we report an updated fit of parameters which account for the known spectrum of quarks and charged lepton masses and the quark mixing in a $4\\times 4$ non-unitary $V_{CKM}$. In this scenario, ordinary heavy fermions, top and bottom quarks and tau lepton, become massive at tree level from Dirac See-saw mechanisms implemented by the introduction of a new set of $SU(2)_L$ weak singlet vector-like fermions, $U,D,E,N$, with $N$ a sterile neutrino. The $N_{L,R}$ sterile neutrinos allow the implementation of a $8\\times 8$ general See-saw Majorana neutrino mass matrix with four massless eigenvalues at tree level. Hence, light fermions, including neutrinos, obtain masses from loop radiative corrections mediated by the massive $SU(3)$ gauge bosons. $SU(3)$ family symmetry is broken spontaneously in two stages, whose hierarchy of scales yield an approximate $SU(2)$ global symmetry associated with the $Z_1, Y_1^\\pm$ gauge boson mas...
A model based on gauge symmetry group G = Gsub(Wk) x [SU(3) x SU(3)]sub(c)
International Nuclear Information System (INIS)
The authors formulate a gauge model for basic interactions based on the symmetry group G = Gsub(Wk) x Gsub(c), where Gsub(c) is the chiral symmetry group [SU(3) x SU(3)]sub(c) in colour space. Gsub(Wk) is taken to be the left-right symmetric model SUsub(L)(2) x SUsub(R)(2) x U(1). The chiral colour symmetry is spontaneously broken in such a way that quarks acquire a common mass, an octet of axial gluons become massive but an octet of vector gluons remain massless. In this way quark mass arises from spontaneous colour chiral symmetry breaking. The experimental consequences of the left-right symmetric model are discussed and it is shown that one version of this model gives results similar to the Salam-Weinberg model for the presently available energies. There is also another version, where the results are again similar to the Salam-Weinberg model except that the y dependence for the asymmetry parameter for the deep inelastic scattering of polarized electrons is completely different although its value at y = 0.21 is compatible with experiment. (author)
Account of Nonpolynomial SU(3)-Breaking Effects By Use of Quantum Groups As Flavor Symmetries
Gavrilik, A M
1998-01-01
Using instead of ordinary flavour symmetries SU(n_f) their corresponding quantum (q-deformed) analogs yields new baryon mass sum rules of extreme accuracy. We show, in the 3-flavour case, that such approach accounts for highly nonlinear (nonpolynomial) SU(3)-breaking effects both in the octet and decuplet baryon masses. A version of this approach is considered that involves q-covariant ingredients in the mass operator. The resulting new 'q-deformed' mass relation (q-MR) is simpler than previously derived q-MRs, but requires, for its empirical validity, a fitting to fix the value of the deformation parameter q. Well-known Gell-Mann--Okubo (GMO) octet mass sum rule is found to result not only from usual SU(3), but also from some exotic symmetry corresponding to the q=-1 (i.e., singular) limit of the q-algebra U_q(su_3).
International Nuclear Information System (INIS)
The phenomenological symplectic model with a Davidson potential is used to construct rotational states for a rare-earth nucleus with microscopic wave functions. The energy levels and E2 transitions obtained are in remarkably close agreement (to within a few percent) with those of the rotor model with vibrational shape fluctations that are adiabatically decoupled from the rotational degrees of freedom. An analysis of the states in terms of their SU(3) content shows that SU(3) is a very poor dynamical symmetry but an excellent quasi-dynamical symmetry for the model. It is argued that such quasi-dynamical symmetry can be expected for any Hamiltonian that reproduces the observed low-energy properties of a well-deformed nucleus, whenever the latter are well-described by the nuclear rotor model
$SU(3)_{F}$ Gauge Family Model and New Symmetry Breaking Scale From FCNC Processes
Bao, Shou-Shan; Wu, Yue-Liang
2015-01-01
Based on the $SU(3)_{F}$ gauge family symmetry model which was proposed to explain the observed mass and mixing pattern of neutrinos, we investigate the symmetry breaking, the mixing pattern in quark and lepton sectors, and the contribution of the new gauge bosons to some flavor changing neutral currents (FCNC) processes at low energy. With the current data of the mass differences in the neutral pseudo-scalar $P^{0}-\\bar{P}^{0}$ systems, we find that the $SU(3)_{F}$ symmetry breaking scale can be as low as 300TeV and the mass of the lightest gauge boson be about $100$TeV. Other FCNC processes, such as the lepton flavor number violation process $\\mu^{-}\\rightarrow e^{-}e^{+}e^{-}$ and the semi-leptonic rare decay $K\\rightarrow \\pi \\bar{\
SU(3)c x SU(3)L x U(1)X gauge symmetry from SU(4)PS x SU(4)L+R
Sen, Sutapa; Dixit, Aparna
2004-01-01
We present a 3-3-1 model as a subgroup of SU(4)PS X SU(4)L+R gauge symmetry with symmetry-breaking pattern SU(4)->SU(3) X U(1) for both SU(4) groups. A Pleitez-Frampton type of 3C-3L-1X model is obtained with charged heavy leptons and SU(3)L gauge bosons (B-L= 0) which are not bileptons. The neutral gauge bosons include gamma,Z,Z'and a fourth Z" which decouples from rest but couples to ordinary fermions. The two-body decay rates for Z' are presented along with their mixings and interactions.
Decays of B mesons to two pseudoscalars in broken SU(3) symmetry
International Nuclear Information System (INIS)
The decays of B mesons to two-body hadronic final states are analyzed within the context of broken flavor SU(3) symmetry, extending a previous analysis involving pairs of light pseudoscalars to decays involving one or two charmed quarks in the final state. A systematic program is described for learning information from decay rates regarding (i) SU(3)-violating contributions, (ii) the magnitude of exchange and annihilation diagrams (effects involving the spectator quark), and (iii) strong final-state interactions. The implication of SU(3)-breaking effects for the extraction of weak phases is also examined. The present status of data on these questions is reviewed and suggestions for further experimental study are made
Triplets, Static SU(6), and Spontaneously Broken Chiral SU(3) Symmetry
Nambu, Y.
1966-01-01
I would like to present here my view of the current problems of elementary particle theory. It is largely inspired by the recent successes of SU(3) and SU(6) symmetries, and more or less summarizes what I have been pursuing lately. For the details of individual problems I must refer to the original papers. However, what is emphasized here is not the details, but a coherent overall picture plus some speculations which cannot yet be formulated precisely.
Centre vortices underpin dynamical chiral symmetry breaking in $\\mathrm{SU}(3)$ gauge theory
Trewartha, Daniel; Leinweber, Derek
2015-01-01
The link between dynamical chiral symmetry breaking and centre vortices in the gauge fields of pure $\\mathrm{SU}(3)$ gauge theory is studied using the overlap-fermion quark propagator in Lattice QCD. Overlap fermions provide a lattice realisation of chiral symmetry and consequently offer a unique opportunity to explore the interplay of centre vortices, instantons and dynamical mass generation. Simulations are performed on gauge fields featuring the removal of centre vortices, identified through gauge transformations maximising the center of the gauge group. In contrast to previous results using the staggered-fermion action, the overlap-fermion results illustrate a loss of dynamical chiral symmetry breaking coincident with vortex removal. This result is linked to the overlap-fermion's sensitivity to the subtle manner in which instanton degrees of freedom are compromised through the process of centre vortex removal. Backgrounds consisting solely of the identified centre vortices are also investigated. After smo...
Strange Baryon Electromagnetic Form Factors and SU(3) Flavor Symmetry Breaking
Energy Technology Data Exchange (ETDEWEB)
Lin, Huey-Wen; Orginos, Konstantinos
2009-01-01
We study the nucleon, Sigma and cascade octet baryon electromagnetic form factors and the effects of SU(3) flavor symmetry breaking from 2+1-flavor lattice calculations. We find that electric and magnetic radii are similar; the maximum discrepancy is about 10\\%. In the pion-mass region we explore, both the quark-component and full-baryon moments have small SU(3) symmetry breaking. We extrapolate the charge radii and the magnetic moments using three-flavor heavy-baryon chiral perturbation theory (HBXPT). The systematic errors due to chiral and continuum extrapolations remain significant, giving rise to charge radii for $p$ and $\\Sigma^-$ that are 3--4 standard deviations away from the known experimental ones. Within these systematics the predicted $\\Sigma^+$ and $\\Xi^-$ radii are 0.67(5) and 0.306(15)~fm$^2$ respectively. When the next-to-next-to-leading order of HBXPT is included, the extrapolated magnetic moments are less than 3 standard deviations away from PDG values, and the d
General Majorana Neutrino Mass Matrix from a Low Energy SU(3) Family Symmetry with Sterile Neutrinos
Hernandez-Galeana, Albino
2014-01-01
Within the framework of a local SU(3) family symmetry model, we report a general analysis of the mechanism for neutrino mass generation and mixing, including light sterile neutrinos. In this scenario, ordinary heavy fermions, top and bottom quarks and tau lepton, become massive at tree level from Dirac See-saw mechanisms implemented by the introduction of a new set of $SU(2)_L$ weak singlet vector-like fermions, U,D,E,N, with N a sterile neutrino. Right-handed and the $N_{L,R}$ sterile neutrinos allow the implementation of a 8x8 general Majorana neutrino mass matrix with four or five massless neutrinos at tree level. Hence, light fermions, including light neutrinos get masses from radiative corrections mediated by the massive SU(3) gauge bosons. We report the corresponding Majorana neutrino mass matrix up to one loop. Previous numerical analysis of the free parameters show out solutions for quarks and charged lepton masses within a parameter space region where the vector-like fermion masses $M_U, M_D, M_E$, a...
Relativistic chiral SU(3) symmetry, large Nc sum rules and meson-baryon scattering
International Nuclear Information System (INIS)
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 Q3 where we include only those terms which are leading in the large Nc 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 Nc 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 Nc 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 plab ≅ 500 MeV. (orig.)
Evidence that centre vortices underpin dynamical chiral symmetry breaking in SU (3) gauge theory
Trewartha, Daniel; Kamleh, Waseem; Leinweber, Derek
2015-07-01
The link between dynamical chiral symmetry breaking and centre vortices in the gauge fields of pure SU (3) gauge theory is studied using the overlap-fermion quark propagator in Lattice QCD. Overlap fermions provide a lattice realisation of chiral symmetry and consequently offer a unique opportunity to explore the interplay of centre vortices, instantons and dynamical mass generation. Simulations are performed on gauge fields featuring the removal of centre vortices, identified through gauge transformations maximising the center of the gauge group. In contrast to previous results using the staggered-fermion action, the overlap-fermion results illustrate a loss of dynamical chiral symmetry breaking coincident with vortex removal. This result is linked to the overlap-fermion's sensitivity to the subtle manner in which instanton degrees of freedom are compromised through the process of centre vortex removal. Backgrounds consisting solely of the identified centre vortices are also investigated. After smoothing the vortex-only gauge fields, we observe dynamical mass generation on the vortex-only backgrounds consistent within errors with the original gauge-field ensemble following the same smoothing. Through visualizations of the instanton-like degrees of freedom in the various gauge-field ensembles, we find evidence of a link between the centre vortex and instanton structure of the vacuum. While vortex removal destabilizes instanton-like objects under O (a4)-improved cooling, vortex-only backgrounds provide gauge-field degrees of freedom sufficient to create instantons upon cooling.
Fouladi, N; Sabri, H
2014-01-01
We consider the possibility of identifying nuclei exhibiting the partial dynamical SU(3) symmetry (SU(3)-PDS) as those having excitation energy ratio R(4/2)>3.00 . For this purpose, the level energy spectra of a set of 51 nuclei in the rare earth and actinide regions which presenting an axially deformed prolate rotational structure were analyzed via nuclear partial dynamical SU(3) symmetry in the framework of interacting boson model, to see if the SU(3)-PDS is broadly applicable, and where, how, and in which nuclei it breaks down. Overall, the PDS works very well, the predictions of such intermediate symmetry structure for energy spectrum were compared with the most recent experimental data and an acceptable degree of agreement is achieved. We conclude that PDS predictions have a more regular behavior in description of axially deformed prolate rotational nuclei than DS, which may lead to accurate predictions of such nuclei, and hence play a significant role in understanding the regular behavior of complex nuc...
Institute of Scientific and Technical Information of China (English)
LI Jie-Ming; CHEN Qi-Zhou; GUO Shuo-Hong
2001-01-01
The random phase approximation is applied to the coupled-cluster expansions of lattice gauge theory (LGT). Using this method, wavefunctions are approximated by linear combination of graphs consisting of only one connected Wilson loop. We study the excited state energy and wavefunction in (2 + 1)-D SU(3) LGT up to thc third order. The glueballmass shows a good scaling behavior.``
Polanco-Euán, E N; Sánchez-Colón, G; Bambah, B A
2016-01-01
The SU(3) octet states with baryon number B = 2, hexaquark dibaryons, are considered. Decay coupling constants sum rules for dibaryon octet into two ordinary baryon octets with ?$\\lambda_8$ first order SU(3) symmetry breaking are given. An SU(4) extension of the analysis is commented upon. Possibilities for the experimental observation of multibaryon and anti-multibaryon states are pointed out.
Silva, P J
2016-01-01
The correlations between the modulus of the Polyakov loop, its phase $\\theta$ and the Landau gauge gluon propagator at finite temperature are investigated in connection with the center symmetry for pure Yang-Mills SU(3) theory. In the deconfined phase, where the center symmetry is spontaneously broken, the phase of the Polyakov loop per configuration is close to $\\theta = 0$, $\\pm \\, 2 \\pi /3$. We find that the gluon propagator form factors associated with $\\theta \\approx 0$ differs quantitatively and qualitatively from those associated to $\\theta \\approx \\pm \\, 2 \\pi /3$. This difference between the form factors is a property of the deconfined phase and a sign of the spontaneous breaking of the center symmetry. Furthermore, given that this difference vanishes in the confined phase, it can be used as an order parameter associated to the deconfinement transition. For simulations near the critical temperature $T_c$, the difference between the propagators associated to $\\theta \\approx 0$ and $\\theta \\approx \\pm ...
Hernandez-Galeana, Albino
2013-01-01
We report a global fit of parameters for fermion masses and mixing, including light sterile neutrinos, within a local vector $SU(3)$ family symmetry model. In this scenario, ordinary heavy fermions, top and bottom quarks and tau lepton, become massive at tree level from {\\bf Dirac See-saw} mechanisms implemented by the introduction of a new set of $SU(2)_L$ weak singlet vector-like fermions, $U,D,E,N$, with $N$ a sterile neutrino. The $N_{L,R}$ sterile neutrinos allow the implementation of a $8\\times 8$ general tree level See-saw Majorana neutrino mass matrix with four massless eigenvalues. Hence, light fermions, including light neutrinos obtain masses from one loop radiative corrections mediated by the massive $SU(3)$ gauge bosons. This BSM model is able to accommodate the known spectrum of quark masses and mixing in a $4\\times 4$ non-unitary $V_{CKM}$ as well as the charged lepton masses. The explored parameter space region provide the vector-like fermion masses: $M_D \\approx 914.365 $GeV, $M_U \\approx 1.5 ...
Galeana, Albino Hernandez
2011-01-01
I report low energy results on the study of fermion masses and mixing for quarks and leptons, including neutrinos within a SU(3) flavor symmetry model, where ordinary heavy fermions, top and bottom quarks and tau lepton become massive at tree level from {\\bf Dirac See-saw} mechanisms implemented by the introduction a new set of $SU(2)_L$ weak singlet vector-like fermions $U,D,E,N$, with $N$ a sterile neutrino. Light fermions obtain masses from one loop radiative corrections mediated by the massive SU(3) gauge bosons. Recent results shows the existence of a low energy space parameter where this model is able to accommodate the known spectrum of quark masses and mixing in a $4\\times 4$ non-unitary $V_{CKM}$ as well as the charged lepton masses. Motivated by the recent LSND and MiniBooNe short-baseline neutrino oscillation experiments we fit for the 3+1 scenario the neutrino squared mass differences $m_2^2 - m_1^2\\approx 7.6\\times 10^{-5}\\;\\text{eV}^2$, $m_3^2 - m_2^2\\approx 2.43\\times 10^{-3} \\text{eV}^2$ and $...
Silva, P. J.; Oliveira, O.
2016-06-01
The correlations between the modulus of the Polyakov loop, its phase θ , and the Landau gauge gluon propagator at finite temperature are investigated in connection with the center symmetry for pure Yang-Mills SU(3) theory. In the deconfined phase, where the center symmetry is spontaneously broken, the phase of the Polyakov loop per configuration is close to θ =0 , ±2 π /3 . We find that the gluon propagator form factors associated with θ ≈0 differ quantitatively and qualitatively from those associated to θ ≈±2 π /3 . This difference between the form factors is a property of the deconfined phase and a sign of the spontaneous breaking of the center symmetry. Furthermore, given that this difference vanishes in the confined phase, it can be used as an order parameter associated to the deconfinement transition. For simulations near the critical temperature Tc, the difference between the propagators associated to θ ≈0 and θ ≈±2 π /3 allows one to classify the configurations as belonging to the confined or deconfined phase. This establishes a selection procedure which has a measurable impact on the gluon form factors. Our results also show that the absence of the selection procedure can be erroneously interpreted as lattice artifacts.
Bazzocchi, F; Picariello, M; Torrente-Lujan, E
2008-01-01
We present a common explanation of the fermion mass hierarchy and the large lepton mixing angles in the context of a grand unified flavor and gauge theory (GUTF). Our starting point is a SU(3)xU(1) flavor symmetry and a SO(10) GUT, a basic ingredient of our theory which plays a major role is that two different breaking pattern of the flavor symmetry are at work. On one side, the dynamical breaking of SU(3)xU(1) flavor symmetry into U(2)xZ_3 explains why one family is much heavier than the others. On the other side, an explicit symmetry breaking of SU(3) into a discrete flavor symmetry leads to the observed tribimaximal mixing for the leptons. We write an explicit model where this discrete symmetry group is A4. Naturalness of the charged fermion mass hierarchy appears as a consequence of the continuous SU(3) flavor symmetry. Moreover, the same discrete A4-GUT invariant operators are the root of the large lepton mixing, small Cabibbo angle, and neutrino masses.
Doff, A.(Universidade Tecnológica Federal do Paraná – UTFPR – DAFIS, Av. Monteiro Lobato Km 04, 84016-210 Ponta Grossa, PR, Brazil)
2007-01-01
The coupling constants $g_L$ and $g_X$ of some versions of the $SU(3)_L\\otimes U(1)_X$ extension of the standard model are related through to relationship $g^2_X/g^2_L= \\sin^2\\theta_W/(1 - 4\\sin^2\\theta_W)$. This fact suggest that the $SU(3)_L\\otimes U(1)_X$ gauge symmetry in this class of models can be broken dynamically to the standard model at TeV scale without requiring the introduction of fundamental scalars. This possibility was investigated by Das and Jain who considered only the first...
Approximate Noether gauge symmetries of the Bardeen model
Energy Technology Data Exchange (ETDEWEB)
Camci, U. [Akdeniz University, Department of Physics, Faculty of Science, Antalya (Turkey)
2014-12-01
We investigate the approximate Noether gauge symmetries of the geodesic Lagrangian for the Bardeen spacetime model. This is accommodated by a set of new approximate Noether gauge symmetry relations for the perturbed geodesic Lagrangian in the spacetime. A detailed analysis of the spacetime of the Bardeen model up to third-order approximate Noether gauge symmetries is presented. (orig.)
An SO(10) model with SU(3) x SU(2)L x SU(2)R x U(1)B-L x D intermediate symmetry
International Nuclear Information System (INIS)
We construct a SO(10) model with intermediate symmetry SU(3) x SU(2)L x SU(2)R x U(1)B-L x D and baryon and lepton number conserved between the two highest scales. The experimental values of sin2 θw and αs are consistent with the lower bound on τP → e++π0 and with a mass value for ντ around 1 eV. (orig.)
International Nuclear Information System (INIS)
We utilize Foldy's canonical representation (m,5/2) + -m,5/2) involving degrees of freedom pertaining to a spin of 5/2 units and make a unitary transformation to the current picture thereby deriving an expressing for the total angular momentum consisting of a together conserved orbital plus an intrinsic spin -1/2 part and yet another separately conserved SU(3)-unitary spin part. We demonstrate this explicity by algebraically deducing the Cartan-Weyl basis for The newly emerging invariance algebra whose eight generators are expressed in terms of three fundamental matrices representing spin-5/2 and proving that this basis excitingly coincides with that of the SU(3) algebra. The derivation of SU(6) in automatically achieved in our theory as a materials consequence Of the SU(3)-symmetry already derived and an SU(2)-spin symmetry guaranteed by the commentativity of Foldys mean sprin operators that find their find their natural places in the unitary-spin parts of the expressions for the Poincare generators, with the Dirac-type hamiltonian acting as the time-transtation generator. As a prelude aderivation of SU(2) is, initially presented working with Foldy's canomical representation (m,3/2) + (-m,3/2). In the process of deriving SU(2), an invariance under the discrete symmetrIc group S3 is also simultaneously datained. (author)
Gauge bosons and fermions in SU(3)C x SU(4)L x U(1)X model with SU(2)H xU(1)AH symmetry
Sen, Sutapa
2009-01-01
We present a phenomenological study of neutral gauge bosons and fermions in an extended Standard model with SU(3)C x SU(4)L x U(1)X gauge symmetry.The model includes gauge bosons and fermions without exotic charges and is distinguished by the symmetry-breaking patern SU(4)L->SU(2)L x SU(2)H x U(1)AH. This introduces an extended electroweak symmetry group SU(2)L x SU(2)H at low energies.We recover the fermion spectra of an anomaly-free three-family 3-4-1 modelwithout exotic chargesfor U(1)X charge X = T3R+(B-L)/2.The interaction of physical neutral gauge bosons Zprime,Z double prime and exotic fermions are presented along with their masses and mixing angle.The electroweak constraints from oblique corections on the model are also calculated.
International Nuclear Information System (INIS)
We construct an SU(3)LxU(1)N gauge model based on an S2L permutation symmetry for left-handed μ and τ families, which provides the almost maximal atmospheric neutrino mixing and the large solar neutrino mixing of the large mixing angle type. Neutrinos acquire one-loop radiative masses induced by the radiative mechanism of the Zee type as well as tree level masses induced by the type II seesaw mechanism utilizing interactions of lepton triplets with an SU(3)-sextet scalar. The atmospheric neutrino mixing controlled by the tree-level and radiative masses turns out to be almost maximal owing to the presence of S2L supplemented by a Z4 discrete symmetry. These symmetries ensure the near equality between the νe-νμ and νe-ντ radiative masses dominated by contributions from heavy leptons contained in the third members of lepton triplets, whose Yukawa interactions conserve S2L even after the spontaneous breaking. The solar neutrino mixing controlled by radiative masses, including a νμ-ντ mass, which are taken to be of similar order, turns out to be described by large solar neutrino mixing angles
SO(10) model with SU(3) x SU(2)/sub L/ x SU(2)/sub R/ x U(1)/sub B-L/ x D intermediate symmetry
Energy Technology Data Exchange (ETDEWEB)
Buccella, F.; Rosa, L.
1987-10-01
We construct a SO(10) model with intermediate symmetry SU(3) x SU(2)/sub L/ x SU(2)/sub R/ x U(1)/sub B-L/ x D and baryon and lepton number conserved between the two highest scales. The experimental values of sin/sup 2/ theta/sub w/ and ..cap alpha../sub s/ are consistent with the lower bound on tau/sub P/ -> e/sup +/+..pi../sup 0/ and with a mass value for ..nu../sub tau/ around 1 eV.
An SO(10) model with SU(3)⊗ SU(2) L ⊗ SU(2) R ⊗ U(1) B-L ⊗ D intermediate symmetry
Buccella, F.; Rosa, L.
1987-09-01
We construct a SO(10) model with intermediate symmetry 10052_2005_Article_BF01573937_TeX2GIFE1.gif SU(3) ⊗ SU(2)_L ⊗ SU(2)_R ⊗ U(1)_{B - L} ⊗ D and baryon and lepton number conserved between the two highest scales. The experimental values of sin2θ w and α s are consistent with the lower bound on τ p→ e ++π0 and with a mass value for v τ around 1 eV.
Energy of Bardeen Model Using Approximate Symmetry Method
Sharif, M.; Waheed, Saira
2010-01-01
In this paper, we investigate the energy problem in general relativity using approximate Lie symmetry methods for differential equations. This procedure is applied to Bardeen model (the regular black hole solution). Here we are forced to evaluate the third-order approximate symmetries of the orbital and geodesic equations. It is shown that energy must be re-scaled by some factor in the third-order approximation. We discuss the insights of this re-scaling factor.
International Nuclear Information System (INIS)
Complete sets of low-lying 1/2- and 3/2- levels in 185W and 187W have been obtained using measurements of primary γ-rays following average resonance neutron capture at mean incident neutron energies of 2 and 24 keV. The results are discussed in terms of both the Nilsson model and the SU(3) boson-fermion symmetry scheme appropriate to this region. The data highlights the advantages and deficiencies of both frameworks, and shows that neither is able to describe the complete spectrum of low-lying low-spin energy levels. The two approaches are outlined and compared and the role of the missing degrees of freedom in each is discussed. (orig.)
Boika, T; Polyakov, M V
2014-01-01
We study the implications of the flavour SU(3) symmetry for various interpretations of the neutron anomaly in the $\\gamma N\\to\\eta N$ cross section. We show that the explanation of the neutron anomaly due to interference of known N(1535) and N(1650) resonances implies that N(1650) resonance should have a huge coupling to $\\phi$-meson -- at least 5 times larger than the corresponding $\\rho^0$ coupling. In terms of quark degrees of freedom this means that the well-known N(1650) resonance must be a "cryptoexotic pentaquark"-- its wave function should contain predominantly an $s\\bar s$ component. It turns out that the "conventional" interpretation of the neutron anomaly by the interference of known resonances metamorphoses into unconventional physics picture of N(1650).
International Nuclear Information System (INIS)
The su(3) mean field approximation describes collective nuclear rotation in a density matrix formalism. The densities ρ=q-i l/2 are 3x3 Hermitian matrices in the su(3) dual space, where q is the expectation of the quadrupole moment and l is the expectation of the angular momentum. The mean field approximation restricts these densities to a level surface of the su(3) Casimirs. Each level surface is a coadjoint orbit of the canonical transformation group SU(3). For each density ρ, the su(3) mean field Hamiltonian h[ρ] is an element of the su(3) Lie algebra. A model su(3) energy functional and the symplectic structure on the coadjoint orbit determine uniquely the su(3) mean field Hamiltonian. The densities in time-dependent su(3) mean field theory obey the dynamical equation i ρ radical = [h[ρ],ρ] on a coadjoint orbit. The cranked mean field Hamiltonian is hΩ=h+iΩ, where Ω is the angular velocity of the rotating principal axis frame. A rotating equilibrium density ρ-tilde in the body-fixed frame is a self-consistent solution to the equation [hΩ[ρ-tilde],ρ-tilde]=0. (author)
Quark Yukawa pattern from spontaneous breaking of flavour $SU(3)^3$
Nardi, Enrico
2015-01-01
A $SU(3)_Q \\times SU(3)_u \\times SU(3)_d$ 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.
Hsu, Jong-Ping
2013-01-01
Gravitational field is the manifestation of space-time translational ($T_4$) gauge symmetry, which enables gravitational interaction to be unified with the strong and the electroweak interactions. Such a total-unified model is based on a generalized Yang-Mills framework in flat space-time. Following the idea of Glashow-Salam-Ward-Weinberg, we gauge the groups $T_4 \\times (SU_3)_{color} \\times SU_2 \\times U_1\\times U_{1b}$ on equal-footing, so that we have the total-unified gauge covariant derivative ${\\bf \\d}_{\\mu} = \\p_{\\mu} - ig\\phi_{\\mu}^{\
Institute of Scientific and Technical Information of China (English)
ZHANG Shun-Li; QU Chang-Zheng
2006-01-01
@@ The concept of approximate generalized conditional symmetry (AGCS) as a generalization to both approximate Lie point symmetry and generalized conditional symmetry is introduced, and it is applied to study the perturbed nonlinear diffusion-convection equations. Complete classification of those perturbed equations which admit cer tain types of AGCSs is derived.
Re-Scaling of Energy in the Stringy Charged Black Hole Solutions using Approximate Symmetries
Sharif, M.; Waheed, Saira
2010-01-01
This paper is devoted to study the energy problem in general relativity using approximate Lie symmetry methods for differential equations. We evaluate second-order approximate symmetries of the geodesic equations for the stringy charged black hole solutions. It is concluded that energy must be re-scaled by some factor in the second-order approximation.
A new method to obtain approximate symmetry of nonlinear evolution equation from perturbations
Institute of Scientific and Technical Information of China (English)
Zhang Zhi-Yong; Yong Xue-Lin; Chen Yu-Fu
2009-01-01
A novel method for obtaining the approximate symmetry of a partial differential equation with a small parameter is introduced. By expanding the independent variable and the dependent variable in the small parameter series, we obtain more affluent approximate symmetries. The method is applied to two perturbed nonlinear partial differential equations and new approximate solutions are derived.
International Nuclear Information System (INIS)
We consider symmetry properties of differential equations in non-relativistic quantum mechanics and classical mechanics. Special emphasis is given to periodically driven systems. For a model system connections between symmetries of corresponding classical and quantal systems are established. The fundamental difference between variational symmetries and symmetries of the Euler-Lagrange-equations is discussed for the special case of classical mechanics. For nonintegrable systems with quasiregular regions in phase space we introduce the notion of approximate symmetry. As an example, we demonstrate the accuracy of such symmetry properties in certain domains of phase space for a periodically driven anharmonic oscillator. (orig.)
Two Approaches to the Calculation of Approximate Symmetry of Ostrovsky Equation with Small Parameter
International Nuclear Information System (INIS)
In this paper, two methods of approximate symmetries for partial differential equations with a small parameter are applied to a perturbed nonlinear Ostrovsky equation. To compute the first-order approximate symmetry, we have applied two methods which one of them was proposed by Baikov et al. in which the infinitesimal generator is expanded in a perturbation series; whereas the other method by Fushchich and Shtelen [3] is based on the expansion of the dependent variables in perturbation series. Especially, an optimal system of one dimensional subalgebras is constructed and some invariant solutions corresponding to the resulted symmetries are obtained
Two Approaches to the Calculation of Approximate Symmetry of Ostrovsky Equation with Small Parameter
Energy Technology Data Exchange (ETDEWEB)
Mahdavi, Abolhassan, E-mail: ad.mahdavi@kiau.ac.ir [Karaj Branch Islamic University, Department of Mathematics (Iran, Islamic Republic of); Nadjafikhah, Mehdi, E-mail: mnadjafikhah@iust.ac.ir [Iran University of Science and Technology, School of Mathematics (Iran, Islamic Republic of); Toomanian, Megerdich, E-mail: megerdich.toomanian@kiau.ac.ir [Karaj Branch Islamic University, Department of Mathematics (Iran, Islamic Republic of)
2015-12-15
In this paper, two methods of approximate symmetries for partial differential equations with a small parameter are applied to a perturbed nonlinear Ostrovsky equation. To compute the first-order approximate symmetry, we have applied two methods which one of them was proposed by Baikov et al. in which the infinitesimal generator is expanded in a perturbation series; whereas the other method by Fushchich and Shtelen [3] is based on the expansion of the dependent variables in perturbation series. Especially, an optimal system of one dimensional subalgebras is constructed and some invariant solutions corresponding to the resulted symmetries are obtained.
Kaon-Baryon Couplings and the Goldberger-Treiman Relation in SU(3) x SU(3)
Nasrallah, N F
2007-01-01
The coupling constants G_(K N Lambda) and G_(K N Sigma) are obtained from the Goldberger-Treiman relation in the strange channel with chiral symmetry breaking taken into account. The results, G_(K N Lambda)=-12.3+-1.2 and G_(K N Sigma)=5.5+-.5 come close to the SU(3) values.
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
An approximate homotopy symmetry method for nonlinear problems is proposed and applied to the sixth-order Boussinesq equation,which arises from fluid dynamics.We summarize the general formulas for similarity reduction solutions and similarity reduction equations of different orders,educing the related homotopy series solutions.Zero-order similarity reduction equations are equivalent to the Painlevé IV type equation or Weierstrass elliptic equation.Higher order similarity solutions can be obtained by solving linear variable coefficients ordinary differential equations.The auxiliary parameter has an effect on the convergence of homotopy series solutions.Series solutions and similarity reduction equations from the approximate symmetry method can be retrieved from the approximate homotopy symmetry method.
Approximate restoration of translational and rotational symmetries within the Lipkin method
Gao, Y; Toivanen, P
2015-01-01
Background: Nuclear self-consistent mean-field approaches are rooted in the density functional theory and, through the spontaneous symmetry breaking mechanism, allow for including important correlations, while keeping the simplicity of the approach. Because real ground states should have all symmetries of the nuclear Hamiltonian, these methods require subsequent symmetry restoration. Purpose: We implement and study Lipkin method of approximate variation after projection applied to the restoration of the translational or rotational symmetries. Methods: We use Lipkin operators up to quadratic terms in momenta or angular momenta with self-consistently determined values of the Peierls-Yoccoz translational masses or moments of inertia, respectively. Calculations based on Skyrme energy-density functional are performed for heavy, deformed, and paired nuclei. Results: In deformed nuclei, the Peierls-Yoccoz translational masses along three different principal-axes directions of the intrinsic system can be different, w...
International Nuclear Information System (INIS)
The group SU(3) is parameterized in terms of generalized open-quotes Euler anglesclose quotes. The differential operators of SU(3) corresponding to the Lie Algebra elements are obtained, the invariant forms are found, the group invariant volume element is found, and some relevant comments about the geometry of the group manifold are made
Properties of non-BPS SU(3) monopoles
International Nuclear Information System (INIS)
This paper is concerned with magnetic monopole solutions of SU(3) Yang-Mills-Higgs system beyond the Bogomol'nyi-Prasad-Sommerfield limit. The different SU(2) embeddings, which correspond to the fundamental monopoles, as well the embedding along composite root are studied. The interaction of two different fundamental monopoles is considered. Dissolution of a single fundamental non-BPS SU(3) monopole in the limit of the minimal symmetry breaking is analyzed. (author)
SU(3) flux tube gluon condensate
Dzhunushaliev, Vladimir
2010-01-01
The distribution of a gluon condensate in a flux tube is calculated. The result is that the chromoelectric fields are confined with a surrounding coset chromomagnetic field. Such picture presents the concrete realization of dual QCD model in a scalar model of the flux tube. In the scalar model the SU(3) gauge fields are separated on two parts: (1) is the $SU(2) \\subset SU(3)$ subgroup, (2) is the coset $SU(3) / SU(2)$. The SU(2) degrees of freedom are almost classical and the coset degrees of freedom are quantum ones. A nonperturbative approach for the quantization of the coset degrees of freedom is applied. In this approach 2-point Green's function is a bilinear combination of scalar fields and 4-point Green's function is the product of 2-points Green's functions. The gluon condensate is an effective Lagrangian describing the SU(2) gauge field with broken gauge symmetry and coupling with the scalar field. Corresponding field equations give us the flux tube.
Approximate symmetries in atomic nuclei from a large-scale shell-model perspective
International Nuclear Information System (INIS)
In this paper, we review recent developments that aim to achieve further understanding of the structure of atomic nuclei, by capitalizing on exact symmetries as well as approximate symmetries found to dominate low-lying nuclear states. The findings confirm the essential role played by the Sp(3, ℝ) symplectic symmetry to inform the interaction and the relevant model spaces in nuclear modeling. The significance of the Sp(3, ℝ) symmetry for a description of a quantum system of strongly interacting particles naturally emerges from the physical relevance of its generators, which directly relate to particle momentum and position coordinates, and represent important observables, such as, the many-particle kinetic energy, the monopole operator, the quadrupole moment and the angular momentum. We show that it is imperative that shell-model spaces be expanded well beyond the current limits to accommodate particle excitations that appear critical to enhanced collectivity in heavier systems and to highly-deformed spatial structures, exemplified by the second 0+ state in 12C (the challenging Hoyle state) and 8Be. While such states are presently inaccessible by large-scale no-core shell models, symmetry-based considerations are found to be essential. (author)
Alkhalifah, Tariq Ali
2012-04-30
Traveltime information is crucial for parameter estimation, especially if the medium is described by a set of anisotropy parameters. We can efficiently estimate these parameters if we are able to relate them analytically to traveltimes, which is generally hard to do in inhomogeneous media. I develop traveltime approximations for transversely isotropic media with a horizontal symmetry axis (HTI) as simplified and even linear functions of the anisotropy parameters. This is accomplished by perturbing the solution of the HTI eikonal equation with respect to the anellipticity parameter, η and the azimuth of the symmetry axis (typically associated with the fracture direction) from a generally inhomogeneous, elliptically anisotropic background medium. Such a perturbation is convenient since the elliptically anisotropic information might be obtained from well velocities in HTI media. Thus, we scan for only η and the symmetry-axis azimuth. The resulting approximations can provide a reasonably accurate analytical description of the traveltime in a homogenous background compared to other published moveout equations. They also help extend the inhomogenous background isotropic or elliptically anisotropic models to an HTI one with a smoothly variable η and symmetry-axis azimuth. © 2012 European Association of Geoscientists & Engineers.
CP violation and flavor SU(3) breaking in D-meson decays
International Nuclear Information System (INIS)
We carry out a systematic flavor SU(3) analysis of D-meson decays including the leading order symmetry breaking effects. We find that SU(3) breaking can easily account for the recent LHCb measurement of the difference in CP asymmetries in the decays of D0 into K+K- and π+π- mesons, once an enhancement mechanism, similar to the Δ=1/2 rule in neutral kaon decays is assumed. As a byproduct of the analysis, one can make predictions regarding the individual asymmetries in K+K-, π+π-, as well as the D0→π0π0 decay channels. Moreover, we find that the asymmetry in the decay D+→π+π0 vanishes in the leading approximation.
Exact and approximate symmetries for light propagation equations with higher order nonlinearity
Garcia, Martin E; Tatarinova, Larisa L
2010-01-01
For the first time exact analytical solutions to the eikonal equations in (1+1) dimensions with a refractive index being a saturated function of intensity are constructed. It is demonstrated that the solutions exhibit collapse; an explicit analytical expression for the self-focusing position, where the intensity tends to infinity, is found. Based on an approximated Lie symmetry group, solutions to the eikonal equations with arbitrary nonlinear refractive index are constructed. Comparison between exact and approximate solutions is presented. Approximate solutions to the nonlinear Schrodinger equation in (1+2) dimensions with arbitrary refractive index and initial intensity distribution are obtained. A particular case of refractive index consisting of Kerr refraction and multiphoton ionization is considered. It is demonstrated that the beam collapse can take place not only at the beam axis but also in an off-axis ring region around it. An analytical condition distinguishing these two cases is obtained and expli...
Color-charge separation in trapped SU(3) fermionic atoms
International Nuclear Information System (INIS)
Cold fermionic atoms with three different hyperfine states with SU(3) symmetry confined in one-dimensional optical lattices show color-charge separation, generalizing the conventional spin-charge separation for interacting SU(2) fermions in one dimension. Through time-dependent density-matrix renormalization-group simulations, we explore the features of this phenomenon for a generalized SU(3) Hubbard Hamiltonian. In our numerical simulations of finite-size systems, we observe different velocities of the charge and color degrees of freedom when a Gaussian wave packet or a charge (color) density response to a local perturbation is evolved. The differences between attractive and repulsive interactions are explored and we note that neither a small anisotropy of the interaction, breaking the SU(3) symmetry, nor the filling impedes the basic observation of these effects.
Spontaneous Breaking of $SU3_{f}$ Down to Isospin
Törnqvist, N A
1996-01-01
The mechanism where flavor symmetry of the standard model is broken spontaneously within the strong interactions of QCD is generalized for models involving nonets of pseudoscalar and vector mesons. After the breaking of chiral symmetry by the vacuum, creating singlets and degenerate octets of massive vector mesons and near massless pseudoscalars, also the SU3f symmetric spectrum is shown to be unstable with respect to s quark loops, and broken into a stable isospin symmetric mass spectrum close to the physical one.
New fixed point action for SU(3) lattice gauge theory
Blatter, Marc; Niedermayer, Ferenc
1996-01-01
We present a new fixed point action for SU(3) lattice gauge theory, which has --- compared to earlier published fixed point actions --- shorter interaction range and smaller violations of rotational symmetry in the static $q\\bar{q}$-potential even at shortest distances.
New fixed point action for SU(3) lattice gauge theory
International Nuclear Information System (INIS)
We present a new fixed point action for SU(3) lattice gauge theory, which has - compared to earlier published fixed point actions - shorter interaction range and smaller violations of rotational symmetry in the static qq potential even at shortest distances. (orig.)
Indian Academy of Sciences (India)
M Hamzavi; S M Ikhdair
2014-07-01
The Hellmann potential is simply a superposition of an attractive Coulomb potential $−a/r$ plus a Yukawa potential e${}^{−δr} /r$. The generalized parametric Nikiforov–Uvarov (NU) method is used to examine the approximate analytical energy eigenvalues and two-component wave function of the Dirac equation with the Hellmann potential for arbitrary spin-orbit quantum number in the presence of exact spin and pseudospin (p-spin) symmetries. As a particular case, we obtain the energy eigenvalues of the pure Coulomb potential in the non-relativistic limit.
International Nuclear Information System (INIS)
Since gravitational wave spacetimes are time-varying vacuum solutions of Einstein's field equations, there is no unambiguous means to define their energy content. However, Weber and Wheeler had demonstrated that they do impart energy to test particles. There have been various proposals to define the energy content, but they have not met with great success. Here we propose a definition using 'slightly broken' Noether symmetries. We check whether this definition is physically acceptable. The procedure adopted is to appeal to 'approximate symmetries' as defined in Lie analysis and use them in the limit of the exact symmetry holding. A problem is noted with the use of the proposal for plane-fronted gravitational waves. To attain a better understanding of the implications of this proposal we also use an artificially constructed time-varying nonvacuum metric and evaluate its Weyl and stress-energy tensors so as to obtain the gravitational and matter components separately and compare them with the energy content obtained by our proposal. The procedure is also used for cylindrical gravitational wave solutions. The usefulness of the definition is demonstrated by the fact that it leads to a result on whether gravitational waves suffer self-damping.
New origin for approximate symmetries from distant breaking in extra dimensions
International Nuclear Information System (INIS)
The recently proposed theories with TeV-scale quantum gravity do not have the usual ultraviolet desert between approximately 103-1019 GeV where effective field theory ideas apply. Consequently, the success of the desert in explaining approximate symmetries is lost, and theories of flavor, neutrino masses, proton longevity or supersymmetry breaking, lose their usual habitat. In this paper we show that these ideas can find a new home in an infrared desert: the large space in the extra dimensions. The main idea is that symmetries are primordially exact on our brane, but are broken at O(1) on distant branes. This breaking is communicated to us in a distance-suppressed way by bulk messengers. We illustrate these ideas in a number of settings: (1) We construct theories for the fermion mass hierarchy which avoid problems with large flavor-changing neutral currents. (2) We re-iterate that proton stability can arise if baryon number is gauged in the bulk. (3) We study limits on light gauge fields and scalars in the bulk coming from rare decays, astrophysics and cosmology. (4) We remark that the same ideas can be used to explain small neutrino masses, as well as hierarchical supersymmetry breaking. (5) We construct a theory with bulk technicolor, avoiding the difficulties with extended technicolor. There are also a number of interesting experimental signals of these ideas: (1) Attractive or repulsive, isotope dependent sub-millimeter forces approximately 106 times gravitational strength, from the exchange of light bulk particles. (2) Novel Higgs decays to light generation fermions plus bulk scalars. (3) Collider production of bulk vector and scalar fields, leading to γ or jet+ missing energy signals as in the case of bulk graviton production, with comparable or larger rates
Symmetry-broken local-density approximation for one-dimensional systems
Rogers, Fergus J M; Loos, Pierre-François
2016-01-01
Within density-functional theory, the local-density approximation (LDA) correlation functional is typically built by fitting the difference between the near-exact and Hartree-Fock (HF) energies of the uniform electron gas (UEG), together with analytic perturbative results from the high- and low-density regimes. Near-exact energies are obtained by performing accurate diffusion Monte Carlo calculations, while HF energies are usually assumed to be the Fermi fluid HF energy. However, it has been known since the seminal work of Overhauser that one can obtain lower, symmetry-broken (SB) HF energies at any density. Here, we have computed the SBHF energies of the one-dimensional UEG and constructed a SB version of the LDA (SBLDA) from the results. We compare the performance of the LDA and SBLDA functionals when applied to one-dimensional systems, including atoms and molecules. Generalization to higher dimensions is also discussed.
SU(3)direct-product U(1) model for electroweak interactions
International Nuclear Information System (INIS)
We consider a gauge model based on a SU(3)direct-product U(1) symmetry in which the lepton number is violated explicitly by charged scalar and gauge bosons, including a vector field with double electric charge
SU(3)-Flavor Anatomy of Non-Leptonic Charm Decays
Hiller, Gudrun; Schacht, Stefan
2012-01-01
We perform a comprehensive SU(3)-flavor analysis of charmed mesons decaying to two pseudoscalar SU(3)-octet mesons. Taking into account SU(3)-breaking effects induced by the splitting of the quark masses, m_s != m_{u,d}, we find that existing data can be described by SU(3)-breaking of the order 30%. The requisite penguin enhancement to accomodate all data on CP violation tends to be even larger than the one extracted from Delta a_{CP}^{dir}(K^+K^-,pi^+pi^-) alone, strengthening explanations beyond the standard model. Despite the large number of matrix elements, correlations between CP asymmetries allow potentially to differentiate between different scenarios for the underlying dynamics, as well as between the standard model and various extensions characterized by SU(3) symmetry and its subgroups. We investigate how improved measurements of the direct CP asymmetries in singly-Cabibbo-suppressed decays can further substantiate the interpretation of the data. We show that particularly informative are the asymmet...
Higgs Phenomenology in the Minimal $SU(3)_L\\times U(1)_X$ Model
Okada, Hiroshi; Okada, Nobuchika; Orikasa, Yuta; Yagyu, Kei
2016-01-01
We investigate the phenomenology of a model based on the $SU(3)_c\\times SU(3)_L\\times U(1)_X$ gauge theory, the so-called 331 model. In particular, we focus on the Higgs sector of the model which is composed of three $SU(3)_L$ triplet Higgs fields, and this corresponds to the minimal form to realize phenomenologically acceptable scenario. After the spontaneous symmetry breaking $SU(3)_L\\times U(1)_X\\to SU(2)_L\\times U(1)_Y$, our Higgs sector effectively becomes that with two $SU(2)_L$ doublet...
Jia, L Y
2016-01-01
The particle-hole symmetry (equivalence) of the full shell-model Hilbert space is straightforward and routinely used in practical calculations. In this work we show that this symmetry is preserved in the subspace truncated at a certain generalized seniority, and give the explicit transformation between the states in the two types (particle and hole) of representations. Based on the results, we study the particle-hole symmetry in popular theories that could be regarded as further truncations on top of the generalized seniority, including the microscopic interacting boson (fermion) model, the nucleon-pair approximation, and others.
Masmoudi, Nabil
2014-01-01
We present an approximate, but efficient and sufficiently accurate P-wave ray tracing and dynamic ray tracing procedure for 3D inhomogeneous, weakly orthorhombic media with varying orientation of symmetry planes. In contrast to commonly used approaches, the orthorhombic symmetry is preserved at any point of the model. The model is described by six weak-anisotropy parameters and three Euler angles, which may vary arbitrarily, but smoothly, throughout the model. We use the procedure for the calculation of rays and corresponding two-point traveltimes in a VSP experiment in a part of the BP benchmark model generalized to orthorhombic symmetry.
Inertial parameters in the interacting boson fermion approximation
International Nuclear Information System (INIS)
The Hartree-Bose-Fermi and the adiabatic approximations are used to derive analytic formulas for the moment of inertia and the decoupling parameter of the interacting boson fermion approximation for deformed systems. These formulas are applied to the SU(3) dynamical symmetry, obtaining perfect agreement with the exact results. (Authors)
Symmetry-broken local-density approximation for one-dimensional systems
Rogers, Fergus J. M.; Ball, Caleb J.; Loos, Pierre-François
2016-06-01
Within density-functional theory, the local-density approximation (LDA) correlation functional is typically built by fitting the difference between the near-exact and Hartree-Fock (HF) energies of the uniform electron gas (UEG), together with analytic perturbative results from the high- and low-density regimes. Near-exact energies are obtained by performing accurate diffusion Monte Carlo calculations, while HF energies are usually assumed to be the Fermi fluid HF energy. However, it has been known since the seminal work of A. W. Overhauser [Phys. Rev. Lett. 3, 414 (1959), 10.1103/PhysRevLett.3.414; Phys. Rev. 128, 1437 (1962), 10.1103/PhysRev.128.1437] that one can obtain lower, symmetry-broken (SB) HF energies at any density. Here, we have computed the SBHF energies of the one-dimensional UEG and constructed a SB version of the LDA (SBLDA) from the results. We compare the performance of the LDA and SBLDA functionals when applied to one-dimensional systems, including atoms and molecules. Generalization to higher dimensions is also discussed.
Leptonic SU(3), grand unification, and higher-dimensionality gravidynamics
Energy Technology Data Exchange (ETDEWEB)
Baaklini, N.S. (International Centre for Theoretical Physics, Trieste (Italy) Dahr el Chir Science Centre, Dhour el Choueir (Lebanon))
1990-06-01
Two considerations pertaining to the electroweak symmetry of leptons, and to higher-dimensionality gravidynamic spacetime-internal unification, lead us to suggest the gauging of SU(15), for each generation of leptons and quarks. On one hand, the electroweak leptonic sector is governed by SU(3), while the quark sector is standard. On the other hand, the Lorentz symmetry of Weyl fermions is generalized to spin-containing SU(2{ital n},C). Sketching the basic elements of the corresponding higher-dimensionality gravidynamics, we point out an associated quark-lepton unification scheme which does not require {ital V}+{ital A} generations.
Denominator function for canonical SU(3) tensor operators
International Nuclear Information System (INIS)
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
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This collection of specially written essays and articles celebrates the sixtieth birthday of Professor Yuval Ne'eman. Professor Ne'eman has been active at the forefront of many areas of modern physics; from SU(3) to Gravity. This book pays tribute to him by reporting and reflecting on the recent developments in these areas. The 36 contributions, all by internationally known and distinguished scientists are grouped under five main headings. The first, on Groups and Gauges has 5 articles, all of which are indexed separately. The second, on Particles has 11 articles, 10 indexed separately. The third, on Science Policy contains 5 articles, 1 indexed separately. The fourth on Astronomy and Astrophysics has 5 articles, 4 indexed separately. The final section on Gravity and Supergravity has 10 articles, all indexed separately. The resulting book will be of interest to researchers in cosmology and astrophysics, particle theory and relativity, and anyone who wishes to keep up to date with the interrelations between these subject areas. (UK)
Sameer M. Ikhdair; Sever, Ramazan
2009-01-01
We study the approximate analytical solutions of the Dirac equation for the generalized Woods-Saxon potential with the pseudo-centrifugal term. In the framework of the spin and pseudospin symmetry concept, the approximately analytical bound state energy eigenvalues and the corresponding upper- and lower-spinor components of the two Dirac particles are obtained, in closed form, by means of the Nikiforov-Uvarov method which is based on solving the second-order linear differential equation by re...
Applications of flavor symmetry to the phenomenology of elementary particles
International Nuclear Information System (INIS)
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
Coupled SU(3)-structures and Supersymmetry
Anna Fino; Alberto Raffero
2015-01-01
We review coupled ${\\rm SU}(3)$-structures, also known in the literature as restricted half-flat structures, in relation to supersymmetry. In particular, we study special classes of examples admitting such structures and the behaviour of flows of ${\\rm SU}(3)$-structures with respect to the coupled condition.
A class of optimal tests for symmetry based on local Edgeworth approximations
Cassart, Delphine; Paindaveine, Davy; 10.3150/10-BEJ298
2011-01-01
The objective of this paper is to provide, for the problem of univariate symmetry (with respect to specified or unspecified location), a concept of optimality, and to construct tests achieving such optimality. This requires embedding symmetry into adequate families of asymmetric (local) alternatives. We construct such families by considering non-Gaussian generalizations of classical first-order Edgeworth expansions indexed by a measure of skewness such that (i) location, scale and skewness play well-separated roles (diagonality of the corresponding information matrices) and (ii) the classical tests based on the Pearson--Fisher coefficient of skewness are optimal in the vicinity of Gaussian densities.
SU(3)-flavons in pati-salam-GUTs
International Nuclear Information System (INIS)
Pati-Salam GUTs are a first step in the direction of a complete fermion unification. As left-right-symmetric extensions of the SM they contain a right-handed neutrino. In addition the symmetry leads to a correlation between leptons and quarks. Thus they provide a framework to study mechanisms generating flavour structures simultaneously in quark and lepton sector. We study a SU(3) flavour symmetry and show how the spontaneous breaking of this symmetry by flavons may generate tribimaximal mixing for the leptons as well as nearly diagonal mixing in the quarks. Within this framework we present a supersymmetric model containing flavoured Higgs fields which may lead to a matter-Higgs-unification. We investigate which flavon representations are useful in constructing models leading to the desired CKM- and PMNS-mechanisms. Furthermore we discuss the problems of this approach and present possible solutions.
Breban, Romulus
2015-01-01
In previous work we discussed the problem of how a 4D observer perceives a 5D space-time and postulated that 4D perception is greatly facilitated if the 5D space-time is symmetric. In particular, if the 5D geometry is independent of the fifth coordinate then the 5D physics can be interpreted as 4D quantum mechanics. In this work we address the case where symmetry is approximate, focusing on the case where the 5D geometry depends weakly on the fifth coordinate. We show that concepts developed for the case of exact symmetry approximatively hold when other concepts such as decaying quantum states, resonant quantum scattering and friction are adopted as well. We briefly comment on the optical model and Millikan's experiment.
String completion of an SU(3)c ⊗ SU(3)L ⊗ U(1)X electroweak model
Addazi, Andrea; Valle, J. W. F.; Vaquera-Araujo, C. A.
2016-08-01
The extended electroweak SU(3)c ⊗ SU(3)L ⊗ U(1)X symmetry framework "explaining" the number of fermion families is revisited. While 331-based schemes can not easily be unified within the conventional field theory sense, we show how to do it within an approach based on D-branes and (un)oriented open strings, on Calabi-Yau singularities. We show how the theory can be UV-completed in a quiver setup, free of gauge and string anomalies. Lepton and baryon numbers are perturbatively conserved, so neutrinos are Dirac-type, and their lightness results from a novel TeV scale seesaw mechanism. Dynamical violation of baryon number by exotic instantons could induce neutron-antineutron oscillations, with proton decay and other dangerous R-parity violating processes strictly forbidden.
String completion of an SU(3c⊗SU(3L⊗U(1X electroweak model
Directory of Open Access Journals (Sweden)
Andrea Addazi
2016-08-01
Full Text Available The extended electroweak SU(3c⊗SU(3L⊗U(1X symmetry framework “explaining” the number of fermion families is revisited. While 331-based schemes can not easily be unified within the conventional field theory sense, we show how to do it within an approach based on D-branes and (unoriented open strings, on Calabi–Yau singularities. We show how the theory can be UV-completed in a quiver setup, free of gauge and string anomalies. Lepton and baryon numbers are perturbatively conserved, so neutrinos are Dirac-type, and their lightness results from a novel TeV scale seesaw mechanism. Dynamical violation of baryon number by exotic instantons could induce neutron–antineutron oscillations, with proton decay and other dangerous R-parity violating processes strictly forbidden.
String completion of an $\\mathrm{SU(3)_c \\otimes SU(3)_L \\otimes U(1)_X}$ electroweak model
Addazi, Andrea; Vaquera-Araujo, C A
2016-01-01
The extended electroweak $\\mathrm{SU(3)_c \\otimes SU(3)_L \\otimes U(1)_X}$ symmetry framework "explaining" the number of fermion families is revisited. While $331$-based schemes can not easily be unified within the conventional field theory sense, we show how to do it within an approach based on D-branes and (un)oriented open strings, on Calabi-Yau singularities. We show how the theory can be UV-completed in a quiver setup, free of gauge and string anomalies. Lepton and baryon numbers are perturbatively conserved, so neutrinos are Dirac-type, and their lightness results from a novel TeV scale seesaw mechanism. Dynamical violation of baryon number by exotic instantons could induce neutron-antineutron oscillations, with proton decay and R-parity violation strictly forbidden.
International Nuclear Information System (INIS)
The space expansion of magnetic field with median plane symmetry in Taylor series is derived in cylindrical coordinate system. The expansion is expressed with the field distribution in the median plane, which may be an analytic expression or the field values at the discrete nodes. The discrete values are fitted with bicubic spline functions and the corresponding computer program is also given
Random matrix theory and acoustic resonances in plates with an approximate symmetry
DEFF Research Database (Denmark)
Andersen, Anders Peter; Ellegaard, C.; Jackson, A.D.;
2001-01-01
the widths for acoustic resonances in thin aluminum plates, cut in the shape of the so-called three-leaf clover. Due to the mirror symmetry through the middle plane of the plate, each resonance of the plate belongs to one of two mode classes and we show how to separate the modes into these two classes...
Sameer M. Ikhdair
2011-01-01
By using an improved approximation scheme to deal with the centrifugal (pseudo-centrifugal) term, we solve the Dirac equation for the generalized Morse potential with arbitrary spin-orbit quantum number {\\kappa}. In the presence of spin and pseudospin symmetry, the analytic bound state energy eigenvalues and the associated upper- and lower-spinor components of two Dirac particles are found by using the basic concepts of the Nikiforov-Uvarov method. We study the special cases when {\\kappa}=\\pm...
Approximate k-state solutions to the Dirac-Yukawa problem based on the spin and pseudospin symmetry
Sameer M. Ikhdair
2012-01-01
Using an approximation scheme to deal with the centrifugal (pseudo-centrifugal) term, we solve the Dirac equation with the screened Coulomb (Yukawa) potential for any arbitrary spin-orbit quantum number {\\kappa}. Based on the spin and pseudospin symmetry, analytic bound state energy spectrum formulas and their corresponding upper- and lower-spinor components of two Dirac particles are obtained using a shortcut of the Nikiforov-Uvarov method. We find a wide range of permissible values for the ...
Fixed point actions in SU(3) gauge theory: surface tension and topology
Farchioni, F.; Papa, A.
1997-01-01
This work is organized in two independent parts. In the first part are presented some results concerning the surface tension in SU(3) obtained with a parametrized fixed point action. In the second part, a new, approximately scale-invariant, parametrized fixed point action is proposed which is suitable to study the topology in SU(3).
Fixed point actions in SU(3) gauge theory: surface tension and topology
International Nuclear Information System (INIS)
This work is organized in two independent parts. In the first part are presented some results concerning the surface tension in SU(3) obtained with a parametrized fixed point action. In the second part, a new, approximately scale-invariant, parametrized fixed point action is proposed which is suitable to study the topology in SU(3). (orig.)
A novel improved action for SU(3) lattice gauge theory
Langfeld, Kurt
2004-01-01
SU(3) lattice gauge theory is studied by means of an improved action where a $2 \\times 2$ Wilson loop is supplemented to the standard plaquette term. By contrast to earlier studies using a tree level improvement, the prefactor of the $2 \\times 2$ Wilson term is determined by minimizing the breaking of rotational symmetry detected from the static quark-antiquark potential. On coarse lattices, the novel action is superior to the Iwasaki action and comparable with DBW2 action. The scaling behavi...
Minimally allowed beta beata 0_nu rates from approximate flavor symmetries
Energy Technology Data Exchange (ETDEWEB)
Jenkins, James [Los Alamos National Laboratory
2008-01-01
Neutrinoless double beta decay ({beta}{beta}0{nu}) is the only realistic probe of Majorana neutrinos. In the standard scenario, dominated by light neutrino exchange, the process amplitude is proportional to m{sub ee} , the e - e element of the Majorana mass matrix. This is expected to hold true for small {beta}{beta}{nu} rates ({Gamma}{sub {beta}{beta}0{nu}}), even in the presence of new physics. Naively, current data allows for vanishing m{sub ee} , but this should be protected by an appropriate flavor symmetry. All such symmetries lead to mass matrices inconsistent with oscillation phenomenology. Hence, Majorana neutrinos imply nonzero {Gamma}{sub {beta}{beta}0{nu}}. I perform a spurion analysis to break all possible abelian symmetries that guarantee {Gamma}{sub {beta}{beta}0{nu}} = 0 and search for minimally allowed m{sub ee} values. Specifically, I survey 259 broken structures to yield m{sub ee} values and current phenomenological constraints under a variety of scenarios. This analysis also extracts predictions for both neutrino oscillation parameters and kinematic quantities. Assuming reasonable tuning levels, I find that m{sub ee} > 4 x 10{sup -6} eV at 99% confidence. Bounds below this value would indicate the Dirac neutrino nature or the existence of new light (eV-MeV scale) degrees of freedom that can potentially be probed elsewhere. This limit can be raised by improvements in neutrino parameter measurements, particularly of the reactor mixing angle, depending on the best fit parameter values. Such improvements will also significantly constrain the available model space and aid in future constructions.
Approximate k-state solutions to the Dirac-Yukawa problem based on the spin and pseudospin symmetry
Ikhdair, Sameer M
2012-01-01
Using an approximation scheme to deal with the centrifugal (pseudo-centrifugal) term, we solve the Dirac equation with the screened Coulomb (Yukawa) potential for any arbitrary spin-orbit quantum number {\\kappa}. Based on the spin and pseudospin symmetry, analytic bound state energy spectrum formulas and their corresponding upper- and lower-spinor components of two Dirac particles are obtained using a shortcut of the Nikiforov-Uvarov method. We find a wide range of permissible values for the spin symmetry constant C_{s} from the valence energy spectrum of particle and also for pseudospin symmetry constant C_{ps} from the hole energy spectrum of antiparticle. Further, we show that the present potential interaction becomes less (more) attractive for a long (short) range screening parameter {\\alpha}. To remove the degeneracies in energy levels we consider the spin and pseudospin solution of Dirac equation for Yukawa potential plus a centrifugal-like term. A few special cases such as the exact spin (pseudospin) s...
Hernández, A. E. Cárcamo; Mart'\\inez, R.; Ochoa, F.
2013-01-01
We take up again the study of the mass spectrum of the quark sector in a model with gauge symmetry $SU(3)_{c}\\otimes SU(3)_{L}\\otimes U(1)_{X}$ (331). In a special type II-like 331 model, we obtain specific zero-texture mass matrices for the quarks which predict four massless quarks ($u,c,d,s$) and two massive quarks ($b,t$) at the electroweak scale ($\\sim $ GeV). By considering the mixing between the SM quarks and new exotic quarks at large scales predicted by the model, we find that a third...
Nucleon instability in a supersymmetric SU(3)c x SU(3)L x U(1) model
International Nuclear Information System (INIS)
We construct the supersymmetric version of a model based on the gauge group SU(3)c x SU(3)L x U(1). We discuss the mechanism of baryon number violation which induces nucleon decay, and derive bounds on the relevant couplings. (author)
International Nuclear Information System (INIS)
This work uses FORM software aspects for obtaining a series of formal results in the non-Abelian gauge theory, with SU(3) group. The work also studies field transformation, Lagrangian density invariance, field equations, energy distribution and the theory reparametrization in terms of fields associated to particles which are possible to be detected in accelerators
Flux tubes in the SU(3) vacuum
Cardaci, Mario S.; Cea, Paolo; Cosmai, Leonardo; Falcone, Rossella; Papa, Alessandro
2011-01-01
We analyze the distribution of the chromoelectric field generated by a static quark-antiquark pair in the SU(3) vacuum. We find that the transverse profile of the flux tube resembles the dual version of the Abrikosov vortex field distribution and give an estimate of the London penetration length in the confined vacuum.
A Nearly Quaternionic Structure on SU(3)
Macia, Oscar
2009-01-01
It is shown that the compact Lie group SU(3) admits an Sp(2)Sp(1)-structure whose distinguished 2-forms $\\omega_1,\\omega_2,\\omega_3$ span a differential ideal. This is achieved by first reducing the structure further to a subgroup isomorphic to SO(3).
Axially symmetric SU(3) gravitating skyrmions
Energy Technology Data Exchange (ETDEWEB)
Ioannidou, Theodora [Maths Division, School of Technology, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece)]. E-mail: ti3@auth.gr; Kleihaus, Burkhard [Institut fuer Physik, Universitaet Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany)]. E-mail: kleihaus@theorie.physik.uni-oldenburg.de; Zakrzewski, Wojtek [Department of Mathematical Sciences, University of Durham, Durham DH1 3LE (United Kingdom)]. E-mail: w.j.zakrzewski@durham.ac.uk
2004-10-21
Axially symmetric gravitating multi-skyrmion configurations are obtained using the harmonic map ansatz introduced in [J. Math. Phys. 40 (1999) 6353]. In particular, the effect of gravity on the energy and baryon densities of the SU(3) non-gravitating multi-skyrmion configurations is studied in detail.
Axially symmetric SU(3) Gravitating Skyrmions
Ioannidou, T A; Zakrzewski, W J; Ioannidou, Theodora; Kleihaus, Burkhard; Zakrzewski, Wojtek
2004-01-01
Axially symmetric gravitating multi-skyrmion configurations are obtained using the harmonic map ansatz introduced in [1]. In particular, the effect of gravity on the energy and baryon densities of the SU(3) non-gravitating multi-skyrmion configurations is studied in detail.
Axially symmetric SU(3) gravitating skyrmions
International Nuclear Information System (INIS)
Axially symmetric gravitating multi-skyrmion configurations are obtained using the harmonic map ansatz introduced in [J. Math. Phys. 40 (1999) 6353]. In particular, the effect of gravity on the energy and baryon densities of the SU(3) non-gravitating multi-skyrmion configurations is studied in detail
Flux tubes in the SU(3) vacuum
Cardaci, M. S.; Cea, P.; Cosmai, L.; Falcone, R.; Papa, A.
We analyze the distribution of the chromoelectric field generated by a static quark-antiquark pair in the SU(3) vacuum. We find that the transverse profile of the flux tube resembles the dual version of the Abrikosov vortex field distribution and give an estimate of the London penetration length in the confined vacuum.
The strong CP problem and nucleon stability in the [SU(3)]3 trinification model
International Nuclear Information System (INIS)
We argue the Peccei-Quinn mechanism in the [SU(3)]3 trinification model. It turns out that the introduction of the Peccei-Quinn symmetry by allowing a third Higgs 27-plet leads to baryon-number conservation. Related discussions are included also. (orig.)
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The energy content of the Lee-Kim-Myung slowly-rotating black hole (Lee et al., Eur. Phys. J. C 70, 361 (2010)), in the Horava-Lifshitz (HL) theory of gravity is investigated by using approximate Lie symmetry methods for differential equations. The energy of this slowly-rotating black hole in the HL gravity is found to be is rescaled by a r-dependent factor. From the rescaling of energy, the rotation is observed to be added to the mass of the black hole, and this effect decreases with increasing coordinate r. This expression of energy rescaling reduces to the Schwarzschild mass for the limits in which the Lee-Kim-Myung slowly rotating black hole solution in the HL gravity reduces to the Schwarzschild solution in general relativity.
Quasi-SU(3) truncation scheme for even-even sd-shell nuclei
Vargas, C E; Draayer, J P
2000-01-01
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 the Hamiltonian used to describe well-deformed nuclei. A practical consequence of the quasi-SU(3) symmetry is an efficient basis truncation scheme. In a recent work was shown that when this type of Hamiltonian is diagonalized in an SU(3) basis, only a few irreducible represntations (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-Ne, 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 ...
Vortices and the SU(3) string tension
Kovács, T. G.; Tomboulis, E. T.
1998-01-01
We present simulation results comparing the SU(3) heavy quark potential extracted from the full Wilson loop expectation to that extracted from the expectation of the Wilson loop fluctuation solely by elements of Z(3). The two potentials are found to coincide. This agreement is stable under multiple smoothings of the configurations which remove short distance fluctuations, and thus reflects long-distance physics. It strongly indicates that the asymptotic string tension arises from thick center...
Tables of SU(3) isoscalar factors
International Nuclear Information System (INIS)
The Clebsch-Gordan coefficients of SU(3) are useful in calculations involving baryons and mesons, as well as in calculations involving arbitrary numbers of quarks. For the latter case, one needs the coupling constants between states of nonintegral hypercharges. The existing published tables are insufficient for many such applications, and therefore we have compiled this collection. This report supplies the isoscalar factors required to reconstruct the Clebsch-Gordan coefficients for a large set of products of representations
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In this paper we will study triangles in SU(3). The orbit space of congruence classes of triangles in SU(3) has dimension 8. Each corner is made up of a pair of tangent vectors (X,Y), and we consider the 8 functions trX2, i trX3, trY2, i trY3, trXY, i trY2Y, i trXY2, trX2Y2 which are invariant under the full isometry group of SU(3). We show that these 8 corner invariants determine the isometry class of the triangle. We give relations (laws of trigonometry) between the invariants at the different corners, enabling us to determine the invariants at the remaining corners, including the values of the remaining side and angles, if we know one set of corner invariants. The invariants that only depend on one tangent vector we will call side invariants, while those that depend on two tangent vectors will be called angular invariants. For each triangle we then have 6 side invariants and 12 angular invariants. Hence we need 18 - 8 = 10 laws of trigonometry. The basic tool for deriving these laws is a formula expressing tr(exp X exp Y) in terms of the corner invariants
Phenomenology of the SU(3)_C \\otimes SU(2)_L \\otimes SU(3)_R \\otimes U(1)_X gauge model
Dong, P V; Loi, D V; Nhuan, N T; Ngan, N T K
2016-01-01
We study the left-right asymmetric model based on SU(3)_C\\otimes SU(2)_L \\otimes SU(3)_R\\otimes U(1)_X gauge group, which improves the theoretical and phenomenological aspects of the known left-right symmetric model. This new gauge symmetry yields that the fermion generation number is three, and the tree-level flavor-changing neutral currents arise in both gauge and scalar sectors. Also, it can provide the observed neutrino masses as well as dark matter automatically. Further, we investigate the mass spectrum of the gauge and scalar fields. All the gauge interactions of the fermions and scalars are derived. We examine the tree-level contributions of the new neutral vector, Z'_R, and new neutral scalar, H_2, to flavor-violating neutral meson mixings, say K-\\bar{K}, B_d-\\bar{B}_d, and B_s-\\bar{B}_s, which strongly constrain the new physics scale as well as the elements of the right-handed quark mixing matrices. The bounds for the new physics scale are in agreement with those coming from the \\rho-parameter as we...
Chiral-symmetry restoration in baryon-rich environments
International Nuclear Information System (INIS)
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)
Particle-hole excitations in the interacting boson model; 4, the U(5)-SU(3) coupling
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.
Two Dimensional Hamiltonian with Generalized Shape Invariance Symmetry
Panahi-Talemi, H.; Jafarizadeh, M. A.
2002-01-01
The two dimensional Hamiltonian with generalized shape invariance symmetry over $S^2$, has been obtained via Fourier transformation over the three coordinates of the $SU(3)$ Casimir operator defined on $SU(3)/SU(2)$ symmetric space. It is shown that the generalized shape invariance is equivalent to $SU(3)$ symmetry and that there is one to one correspondence between the representations of the generalized shape invariance and $SU(3)$ Verma modules. Also the two dimensional Hamiltonian in $\\mat...
Reducing democratic type II supergravity on SU(3) x SU(3) structures
Cassani, Davide
2008-01-01
Type II supergravity on backgrounds admitting SU(3) x SU(3) structure and general fluxes is considered. Using the generalized geometry formalism, we study dimensional reductions leading to N=2 gauged supergravity in four dimensions, possibly with tensor multiplets. In particular, a geometric formula for the full N=2 scalar potential is given. Then we implement a truncation ansatz, and derive the complete N=2 bosonic action. While the NSNS contribution is obtained via a direct dimensional reduction, the contribution of the RR sector is computed starting from the democratic formulation and demanding consistency with the reduced equations of motion.
Higgs Phenomenology in the Minimal $SU(3)_L\\times U(1)_X$ Model
Okada, Hiroshi; Orikasa, Yuta; Yagyu, Kei
2016-01-01
We investigate the phenomenology of a model based on the $SU(3)_c\\times SU(3)_L\\times U(1)_X$ gauge theory, the so-called 331 model. In particular, we focus on the Higgs sector of the model which is composed of three $SU(3)_L$ triplet Higgs fields, and this corresponds to the minimal form to realize phenomenologically acceptable scenario. After the spontaneous symmetry breaking $SU(3)_L\\times U(1)_X\\to SU(2)_L\\times U(1)_Y$, our Higgs sector effectively becomes that with two $SU(2)_L$ doublet scalar fields, in which the first and the second generation quarks couple to the different Higgs doublet from that couples to the third generation quarks. This structure causes the flavour changing neutral current mediated by Higgs bosons at the tree level. By taking an alignment limit of the mass matrix for the CP-even Higgs bosons, which is naturally realized in the case with the breaking scale of $SU(3)_L\\times U(1)_X$ to be much larger than that of $SU(2)_L\\times U(1)_Y$, we can avoid current constraints from flavour...
More flavor SU(3) tests for new physics in CP violating B decays
International Nuclear Information System (INIS)
The recent LHCb measurements of the Bs→K−π+ and Bs→K+K− rates and CP asymmetries are in agreement with U-spin expectations from Bd→K+π− and Bd→π+π− results. We derive the complete set of isospin, U-spin, and SU(3) relations among the CP asymmetries in two-body charmless B→PP and B→PV decays, some of which are novel. To go beyond the unbroken SU(3) limit, we present relations which are properly defined and normalized to allow incorporation of SU(3) breaking in the simplest manner. We show that there are no CP relations beyond first order in SU(3) and isospin breaking. We also consider the corresponding relations for charm decays. Comparing parametrizations of the leading order sum rules with data can shed light on the applicability and limitations of both the flavor symmetry and factorization-based descriptions of SU(3) breaking. Two factorization relations can already be tested, and we show they agree with current data
Hernández, A E Cárcamo; Ochoa, F
2013-01-01
We take up again the study of the mass spectrum of the quark sector in a model with gauge symmetry $SU(3)_{c}\\otimes SU(3)_{L}\\otimes U(1)_{X}$ (331). In a special type II-like 331 model, we obtain specific zero-texture mass matrices for the quarks which predict four massless quarks ($u,c,d,s$) and two massive quarks ($b,t$) at the electroweak scale ($\\sim $ GeV). By considering the mixing between the SM quarks and new exotic quarks at large scales predicted by the model, we find that a third quark (associated to the charm quark) acquires a mass. The remaining light quarks ($u,d,s$) get small masses ($\\sim$ MeV) via radiative corrections.
Exceptional Lie algebras, SU(3) and Jordan pairs: part 2. Zorn-type representations
International Nuclear Information System (INIS)
A representation of the exceptional Lie algebras reflecting a simple unifying view, based on realizations in terms of Zorn-type matrices, is presented. The role of the underlying Jordan pair and Jordan algebra content is crucial in the development of the structure. Each algebra contains three Jordan pairs sharing the same Lie algebra of automorphisms and the same external su(3) symmetry. The applications in physics are outlined. (paper)
Dark Matter from a Classically Scale-Invariant $SU(3)_X$
Karam, Alexandros; Tamvakis, Kyriakos
2016-01-01
In this work we study a classically scale-invariant extension of the Standard Model in which the dark matter and electroweak scales are generated through the Coleman-Weinberg mechanism. The extra $SU(3)_X$ gauge factor gets completely broken by the vevs of two scalar triplets. Out of the eight resulting massive vector bosons the three lightest are stable due to an intrinsic $Z_2\\times Z_2'$ discrete symmetry and can constitute dark matter candidates. We analyze the phenomenological viability ...
SU(3)-flavour breaking in octet baryon masses and axial couplings
Carrillo-Serrano, Manuel E.; Cloët, Ian C.; Thomas, Anthony W.(CSSM and ARC Centre of Excellence for Particle Physics at the Tera-scale, School of Chemistry and Physics, University of Adelaide, Adelaide, SA 5005, Australia 1 1 http://www.physics.adelaide.edu.au/cssm .)
2014-01-01
The lightest baryon octet is studied within a covariant and confining Nambu--Jona-Lasinio model. By solving the relativistic Faddeev equations including scalar and axialvector diquarks, we determine the masses and axial charges for \\Delta S = 0 transitions. For the latter the degree of violation of SU(3) symmetry arising because of the strange spectator quark(s) is found to be up to 10%.
Two and three dimensional Hamiltonians with generalized and ordinary shape invariance symmetry
International Nuclear Information System (INIS)
Two and three dimensional Hamiltonians with generalized and ordinary shape invariance symmetry have been obtained by Fourier transforming over some coordinates of the SU(3) Casimir operator defined on SU(3)/SU(2) symmetric space. It is shown that the generalized shape invariance of the two dimensional Hamiltonian is equivalent to SU(3) symmetry while in the three dimensional one, the ordinary shape invariance is equivalent to contracted SU(3) and there is one to one correspondence between the representations of the generalized shape invariance symmetry of the two (three) dimensional Hamiltonian and SU(3) [contracted SU(3)] Verma bases
New phases of SU(3) and SU(4) at finite temperature
International Nuclear Information System (INIS)
The addition of an adjoint Polyakov loop term to the action of a pure gauge theory at finite temperature leads to new phases of SU(N) gauge theories. For SU(3), a new phase is found which breaks Z(3) symmetry in a novel way; for SU(4), the new phase exhibits spontaneous symmetry breaking of Z(4) to Z(2), representing a partially-confined phase in which quarks are confined, but diquarks are not. The overall phase structure and thermodynamics is consistent with a theoretical model of the effective potential for the Polyakov loop based on perturbation theory
Symmetry breaking patterns of the 3-3-1 model at finite temperature
Borges, J Sá
2016-01-01
We consider the minimal version of an extension of the standard electroweak model based on the $SU(3)_c \\times SU(3)_L \\times U(1)_X$ gauge symmetry (the 3-3-1 model). We analyze the most general potential constructed from three scalars in the triplet representation of $SU(3)_L$, whose neutral components develop nonzero vacuum expectation values, giving mass for all the model massive particles. {}For a convenient choice of parameters, we obtain the particle spectrum for the two symmetry breaking scales: one where the $SU(3)_L \\times U(1)_X$ group is broken down to $SU(2)_L\\times U(1)_Y$ and a lower scale similar to the standard model one. Within the approximations 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. We determine the respective critical temperatures for symmetry r...
Quaternion-Octonion Unitary Symmetries and Analogous Casimir Operators
Pushpa,; Li, Tianjun; Negi, O P S
2012-01-01
An attempt has been made to investigate the global SU(2) and SU(3) unitary flavor symmetries systematically in terms of quaternion and octonion respectively. It is shown that these symmetries are suitably handled with quaternions and octonions in order to obtain their generators, commutation rules and symmetry properties. Accordingly, Casimir operators for SU(2)and SU(3) flavor symmetries are also constructed for the proper testing of these symmetries in terms of quaternions and octonions.
International Nuclear Information System (INIS)
We generalize the finite-range momentum- and density-dependent Seyler-Blanchard nucleon-nucleon effective interaction to the case of interaction between two baryons. This effective interaction is then used to describe dense hadronic matter relevant to neutron stars in the non-relativistic Thomas-Fermi approach. We investigate the behaviour of nuclear symmetry energy in dense nuclear and hyperon matter relevant to neutron stars. It is found that the nuclear symmetry energy always increases with density in hyperon matter unlike the situation in nuclear matter. This rising characteristic of the symmetry energy in the presence of hyperons may have significant implications on the mass-radius relationship and the cooling properties of neutron stars. We have also noted that with the appearance of hyperons, the equation of state calculated in this model remains causal at high density. (author)
Mean field analysis of SU(3) lattice Yang-Mills theory at finite temperature
International Nuclear Information System (INIS)
The phase diagram of the SU(3) four-dimensional space-time lattice Yang-Mills field theory at finite temperature is analysed by the extended mean-field technique. With this technique, finite temperature effects are present already at the saddle point approximation. A reasonable quantitative agreement with Monte Carlo numerical simulations is obtained. (author)
Phenomenological aspects of a left-right model based on SU(3)
Energy Technology Data Exchange (ETDEWEB)
Doas, Alex G.; Nishi, Celso C. [Universidade Federal do ABC (UFABC), SP (Brazil)
2011-07-01
Full text: Motivated by the problem of explaining the observed maximal parity violation in the electroweak interactions, we develop a model based on the SU(3){sub L} x SU(3){sub R} x U(1){sub X} gauge symmetry, where anomalies cancellation restricts the number of families is restricted to be a multiple of three. Left-right symmetry is fully realized in the model and the standard model arises in the low energy limit. The fermionic representation content has, besides standard model fields, nine additional neutrinos which could be linked with problems like neutrino oscillation, warm dark matter and baryogenesis; six new quarks which could show up at the TeV; and also new gauge bosons whose production and associated effects observed in colliders shall indicate the parity restoration. Our focus will be mainly on the spontaneous symmetry breakdown patterns leading to a compatible scenario for particle interactions with the well tested standard model. In order to break the symmetries we take into account a set of scalar fields representation content composed by: two sextets and two bi-triplets. These fields are sufficient to implement a successful mass generation mechanisms, furnishing also a consistent mixing among the fermions. We discuss the main phenomenological issues of the model. (author)
Form factors in SU(3)-invariant integrable models
Belliard, S; Ragoucy, E; Slavnov, N A
2013-01-01
We study SU(3)-invariant integrable models solvable by nested algebraic Bethe ansatz. We obtain determinant representations for form factors of diagonal entries of the monodromy matrix. This representation can be used for the calculation of form factors and correlation functions of the XXX SU(3)-invariant Heisenberg chain.
On some properties of SU(3) Fusion Coefficients
Coquereaux, Robert
2016-01-01
Three aspects of the SU(3) fusion coefficients are revisited: the generating polynomials of fusion coefficients are written explicitly; some curious identities generalizing the classical Freudenthal-de Vries formula are derived; and the properties of the fusion coefficients under conjugation of one of the factors, previously analysed in the classical case, are extended to the affine algebra of su(3) at finite level.
The Gauge Bosons Masses in a SU(2)_TC x SU(3)_L x U(1)_X Extension of the Standard Model
Doff, A.(Universidade Tecnológica Federal do Paraná – UTFPR – DAFIS, Av. Monteiro Lobato Km 04, 84016-210 Ponta Grossa, PR, Brazil)
2010-01-01
The gauge symmetry breaking in 3-3-1 models can be implemented dynamically because at the scale of a few TeVs the U(1)_X coupling constant becomes strong. The exotic quark T introduced in the model will form a condensate breaking SU(3)_L x U(1)_X to electroweak symmetry. In this work we explore the full realization of the dynamical symmetry breaking of an 3-3-1 model to U(1)_{em} considering a model based on SU(2)_TC x SU(3)_L x U(1)_X. We compute the mass generated for the charged and neutra...
Confining properties of the classical SU(3) Yang - Mills theory
Dzhunushaliev, V D
1996-01-01
The spherically and cylindrically symmetric solutions of the $SU(3)$ Yang - Mills theory are obtained. The corresponding gauge potential has the confining properties. It is supposed that: a) the spherically symmetric solution is a field distribution of the classical ``quark'' and in this sense it is similar to the Coulomb potential; b) the cylindrically symmetric solution describes a classical field ``string'' (flux tube) between two ``quarks''. It is noticed that these solutions are typically for the classical $SU(3)$ Yang - Mills theory in contradiction to monopole that is an exceptional solution. This allows to conclude that the confining properties of the classical $SU(3)$ Yang - Mills theory are general properties of this theory.
Skyrmions from SU(3) harmonic maps and their quantization
Kopeliovich, V B; Zakrzewski, W J
2000-01-01
Static properties of SU(3) multiskyrmions with baryon number up to 6(classical masses and momenta of inertia) are estimated. The calculations arebased on the recently suggested generalization of the SU(2) rational mapansaetze applied to the SU(3) model. Both SU(2) embedded skyrmions and genuineSU(3) solutions are considered, and it is shown that although, at the classicallevel, the energy of embeddings is lower, the quantum corrections can alterthis conclusion. This correction to the energy of lowest state, bilinear in theWess-Zumino (WZ) term, is presented for the most general case as a convolutionof the inverse tensor of inertia and the components of the WZ-term.
Transport coefficients from SU(3) Polyakov linear-σ model
International Nuclear Information System (INIS)
In the mean field approximation, the grand potential of SU(3) Polyakov linear-σ model (PLSM) is analyzed for the order parameter of the light and strange chiral phase-transitions, σl and σs, respectively, and for the deconfinement order parameters φ and φ*. Furthermore, the subtracted condensate Δl,s and the chiral order-parameters Mb are compared with lattice QCD calculations. By using the dynamical quasiparticle model (DQPM), which can be considered as a system of noninteracting massive quasiparticles, we have evaluated the decay width and the relaxation time of quarks and gluons. In the framework of LSM and with Polyakov loop corrections included, the interaction measure Δ/T4, the specific heat cv and speed of sound squared cs2 have been determined, as well as the temperature dependence of the normalized quark number density nq/T3 and the quark number susceptibilities χq/T2 at various values of the baryon chemical potential. The electric and heat conductivity, σe and κ, and the bulk and shear viscosities normalized to the thermal entropy, ζ/s and η/s, are compared with available results of lattice QCD calculations.
Exact solutions to D=2 Supersymmetric Yang-Mills Quantum Mechanics with SU(3) gauge group
Korcyl, Piotr
2009-01-01
In this article we present the cut Fock space approach to the D=d+1=2, Supersymmetric Yang-Mills Quantum Mechanics (SYMQM). We start by briefly introducing the main features of the framework. We concentrate on those properties of the method which make it a convenient set up not only for numerical calculations but also for analytic computations. In the main part of the article a sample of results are discussed, namely, analytic and numerical analysis of the D=2, SYMQM systems with SU(2) and SU(3) gauge symmetry.
Finite-temperature study of eight-flavor SU(3) gauge theory
Schaich, David; Rinaldi, Enrico
2015-01-01
We present new lattice investigations of finite-temperature transitions for SU(3) gauge theory with Nf=8 light flavors. Using nHYP-smeared staggered fermions we are able to explore renormalized couplings $g^2 \\lesssim 20$ on lattice volumes as large as $48^3 \\times 24$. Finite-temperature transitions at non-zero fermion mass do not persist in the chiral limit, instead running into a strongly coupled lattice phase as the mass decreases. That is, finite-temperature studies with this lattice action require even larger $N_T > 24$ to directly confirm spontaneous chiral symmetry breaking.
Is SU(3) Chiral Perturbation Theory an Effective Field Theory?
Holstein, Barry R.
1998-01-01
We argue that the difficulties associated with the convergence properties of conventional SU(3) chiral perturbation theory can be ameliorated by use of a cutoff, which suppresses the model-dependent short distance effects in such calculations.
Soliton Solution of SU(3) Gauge Fields at Finite Temperature
Institute of Scientific and Technical Information of China (English)
WANG Dian-Fu; SONG He-Shan
2005-01-01
@@ Starting from a soliton model of SU(3) gauge fields, we investigate the behaviour of the model at finite temperature. it is found that colour confinement at zero temperature can be melted away under high temperatures.
Flux tubes and coherence length in the SU(3) vacuum
Cea, Paolo; Cosmai, Leonardo; Cuteri, Francesca; Papa, Alessandro
2013-01-01
An estimate of the London penetration and coherence lengths in the vacuum of the SU(3) pure gauge theory is given downstream an analysis of the transverse profile of the chromoelectric flux tubes. Within ordinary superconductivity, a simple variational model for the magnitude of the normalized order parameter of an isolated vortex produces an analytic expression for magnetic field and supercurrent density. In the picture of SU(3) vacuum as dual superconductor, this expression provides us with...
Intermediate Symmetries in the Spontaneous Breaking of Supersymmetric SO(10)
Buccella, F.; Savoy, C. A.
We study the supersymmetric spontaneous symmetry breaking of SO(10) into SU(3) ⊗ SU(2) ⊗ U(1) for the most physically interesting cases of SU(5) or flipped SU(5) ⊗ U(1) intermediate symmetries. The first case is more easily realized while the second one requires a fine-tuning condition on the parameters of the superpotential. This is because in the case of SU(5) symmetry there is at most one singlet of the residual symmetry in each SO(10) irreducible representation. We also point out on more general grounds in supersymmetric GUTs that some intermediate symmetries can be exactly realized and others can only be approximated by fine-tuning. In the first category, there could occur some tunneling between the vacua with exact and approximate intermediate symmetry. The flipped SU(5) ⊗ U(1) symmetry improves the unification of gauge couplings if (B-L) is broken by ∥(B-L)∥ =1 scalars yielding right-handed neutrino masses below 1014 GeV.
Intermediate Symmetries in the Spontaneous Breaking of Supersymmetric SO(10)
Buccella, F
2002-01-01
We study the supersymmetric spontaneous symmetry breaking of SO(10) into SU(3)xSU(2)xU(1) for the most physically interesting cases of SU(5) or flipped SU(5)xU(1) intermediate symmetries. The first case is more easily realized while the second one requires a fine-tuning condition on the parameters of the superpotential. This is because in the case of SU(5) symmetry there is at most one singlet of the residual symmetry in each SO(10) irreducible representation. We also point out on more general grounds in supersymmetric GUT's that some intermediate symmetries can be exactly realized and others can only be approximated by fine-tuning. In the first category, there could occur some tunneling between the vacua with exact and approximate intermediate symmetry. The flipped SU(5)xU(1) symmetry improves the unification of gauge couplings if (B-L) is broken by (B-L)=1 scalars yielding right handed neutrino masses below 10^{14} GeV}.
Heavy quark solitons strangeness and symmetry breaking
Momen, A; Subbaraman, A; Momen, Arshad; Schechter, Joseph; Subbaraman, Anand
1994-01-01
We discuss the generalization of the Callan-Klebanov model to the case of heavy quark baryons. The light flavor group is considered to be $SU(3)$ and the limit of heavy spin symmetry is taken. The presence of the Wess-Zumino-Witten term permits the neat development of a picture , at the collective level, of a light diquark bound to a ``heavy" quark with decoupled spin degree of freedom. The consequences of $SU(3)$ symmetry breaking are discussed in detail. We point out that the $SU(3)$ mass splittings of the heavy baryons essentially measure the ``low energy" physics once more and that the comparison with experiment is satisfactory.
Heavy quark solitons: Strangeness and symmetry breaking
International Nuclear Information System (INIS)
We discuss the generalization of the Callan-Klebanov model to the case of heavy quark baryons. The light flavor group is considered to be SU(3) and the limit of heavy spin symmetry is taken. The presence of the Wess-Zumino-Witten term permits the neat development of a picture, at the collective level, of a light diquark bound to a ''heavy'' quark with decoupled spin degree of freedom. The consequences of SU(3) symmetry breaking are discussed in detail. We point out that the SU(3) mass splitting of the heavy baryons essentially measure the ''low energy'' physics once more and that the comparison with experiment is satisfactory
Glueball-like screening masses in pure SU(3) at finite temperatures
International Nuclear Information System (INIS)
We investigate the finite-temperature excitation spectrum in the gluon sector of SU(3) pure gauge theory through measurements of screening masses in correlations of loop operators. We develop the classification of such operators under the symmetry group of the ''z-slice''. In the confined phase of the theory, we find that the spectrum dynamically realises the zero-temperature symmetries. We observe a large thermal shift of the 0++ glueball mass. In the deconfined phase, the spectrum distinguishes between operators coupling to electrically and magnetically polarised gluon fields. The former yields a screening mass equal to the Wilson-line screening mass; the latter a method for the measurement of the magnetic mass in the high-temperature limit. (orig.)
The SU(3) Nambu-Jona-Lasinio soliton in the collective quantization formulation
International Nuclear Information System (INIS)
On grounds of a semibosonized Nambu-Jona-Lasinio model, which has SU(3)RxSU(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 can 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 diagnonalized by means of strict perturbation theory in the strange-quark mass and by the Yabu-Ando 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 of Guadagnini and the latter one is able to describe the mass splittings up to a few MeV. (orig.)
Mass Formulas Derived by Symmetry Breaking and Prediction of Masses on Heavy Flavor Hadrons
Chang, Yi-Fang
2008-01-01
The base is the Lagrangian of symmetry and its dynamical breaking or Higgs breaking. When the soliton-like solutions of the scalar field equations are substituted into the spinor field equations, in the approximation of non-relativity we derive the Morse-type potential, whose energy spectrum is the GMO mass formula and its modified accurate mass formula. According to the symmetry of s-c quarks, the heavy flavor hadrons which made of u,d and c quarks may be classified by SU(3) octet and decuplet. Then some simple mass formulas are obtained, from this we predict some masses of unknown hadrons.
Symmetry and Phase Transitions in Nuclei
International Nuclear Information System (INIS)
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)
International Nuclear Information System (INIS)
Internal and space-time symmetries are discussed in this group of lectures. The first of the lectures deals with an internal symmetry, or rather two related symmetries called charge independence and charge symmetry. The next two discuss space-time symmetries which also hold approximately, but are broken only by the weak forces; that is, these symmetries hold for both the hadronic and electromagnetic forces
SU(3) Approach to Hypernuclear Interactions and Spectroscopy
Lenske, H; Gaitanos, T
2016-01-01
The $SU(3)$ meson exchange approach to interactions within the baryon octet and nuclear density functional theory are used to derive an \\emph{ab initio} description of hypernuclear interactions. The density dependence of interactions is recast into a DFT with density dependent interaction vertices. The field-theoretical structure is retained by expressing the vertices as functionals of the matter field operators. Applications to infinite hypermatter and neutron star matter are discussed. A new approach is presented allowing to determine in-medium coupling constants out of the $NN$-vertex functionals, obtained e.g. by DBHF theory, for the full baryon octet by exploiting $SU(3)$ relations.
Flux tubes and coherence length in the SU(3) vacuum
Cea, Paolo; Cuteri, Francesca; Papa, Alessandro
2013-01-01
An estimate of the London penetration and coherence lengths in the vacuum of the SU(3) pure gauge theory is given downstream an analysis of the transverse profile of the chromoelectric flux tubes. Within ordinary superconductivity, a simple variational model for the magnitude of the normalized order parameter of an isolated vortex produces an analytic expression for magnetic field and supercurrent density. In the picture of SU(3) vacuum as dual superconductor, this expression provides us with the function that fits the chromoelectric field data. The smearing procedure is used in order to reduce noise.
Flux tubes and coherence length in the SU(3) vacuum
Cea, P.; Cosmai, L.; Cuteri, F.; Papa, A.
An estimate of the London penetration and coherence lengths in the vacuum of the SU(3) pure gauge theory is given downstream an analysis of the transverse profile of the chromoelectric flux tubes. Within ordinary superconductivity, a simple variational model for the magnitude of the normalized order parameter of an isolated vortex produces an analytic expression for magnetic field and supercurrent density. In the picture of SU(3) vacuum as dual superconductor, this expression provides us with the function that fits the chromoelectric field data. The smearing procedure is used in order to reduce noise.
Quark and lepton generations: CP-violation and rare processes in SUSY SU(3)HV-gauge horizontal model
International Nuclear Information System (INIS)
In this paper, the current state of the generation mixing and CP-violation problems is discussed from the standpoint of the hypothetical existence of SUSY - SU(3)HV-gauge horizontal symmetry. The behaviour of the estimates for the horizontal symmetry breaking scale showed certain regularities depending on particular symmetry breaking schemes and generation mixing mechanisms (different anzatzes for quark and lepton mass matrices with 3 and 4 generations have been discussed). Supersymmetry is supposed to be important for: the hierarchy problem, certain useful constraints on Yukawa couplings, the super-Higgs effect in the case of a broken local horizontal symmetry, the estimates of the gauge coupling constants gH and the restrictions on the horizontal gaugino masses. 24 refs
Symmetries, Symmetry Breaking, Gauge Symmetries
Strocchi, Franco
2015-01-01
The concepts of symmetry, symmetry breaking and gauge symmetries are discussed, their operational meaning being displayed by the observables {\\em and} the (physical) states. For infinitely extended systems the states fall into physically disjoint {\\em phases} characterized by their behavior at infinity or boundary conditions, encoded in the ground state, which provide the cause of symmetry breaking without contradicting Curie Principle. Global gauge symmetries, not seen by the observables, are nevertheless displayed by detectable properties of the states (superselected quantum numbers and parastatistics). Local gauge symmetries are not seen also by the physical states; they appear only in non-positive representations of field algebras. Their role at the Lagrangian level is merely to ensure the validity on the physical states of local Gauss laws, obeyed by the currents which generate the corresponding global gauge symmetries; they are responsible for most distinctive physical properties of gauge quantum field ...
String tension in SU(3) lattice gauge theory
International Nuclear Information System (INIS)
Wilson loop expectation values have been determined in SU(3) lattice gauge theory without fermions using Monte Carlo methods and considering lattices up to 104 sites. A heat bath technique has been developed in order to enhance the statistical independence of successive lattice configurations. (author)
Parida, M K; Das, C R; Purkayastha, B; 10.1140/epjc/s2003-01180-x
2003-01-01
In a class of SUSY SO(10) with SU(2)/sub L/*SU(2)/sub R/*U(1)/sub B-L /*SU(3)/sub C/ (g/sub 2L/ not= g/sub 2R/) intermediate gauge symmetry, we observe that the prediction on the unification mass (M /sub U/) is unaffected by Planck-scale-induced gravitational and intermediate-scale threshold effects, although the intermediate scale (M/sub I/) itself is subject to such corrections. In particular, without invoking the presence of additional lighter scalar degrees of freedom but including plausible and reasonable threshold effects, we find that interesting solutions for neutrino physics corresponding to M/sub I/ approximately= 10/sup 10/-10/sup 13/ GeV and M/sub U/ approximately= (5-6) * 10/sup 17/ GeV are permitted in the minimal models. The possibilities of low-mass right-handed gauge bosons corresponding to M/sub I/ approximately= 1-10 TeV consistent with the CERN-LEP data are pointed out in a number of models in which threshold effects are included using effective mass parameters. (39 refs).
Kotb, M.
2016-07-01
In the framework of the interacting boson model (IBM) with intrinsic coherent state, the shape Hamiltonian from spherical vibrator U(5) to axially symmetric prolate deformed rotator SU(3) are examined. The Hamiltonian used is composed of a single boson energy term and quadrupole term. The potential energy surfaces (PES' s) corresponding to the U(5)-SU(3) transition are calculated with variation of a scaling and control parameters. The model is applied to 150-162Dy chain of isotopes. In this chain a change from spherical to well deformed nuclei is observed when moving from the lighter to heavier isotopes. 156Dy is a good candidate for the critical point symmetry X(5). The parameters of the model are determined by using a computer simulated search program in order to minimize the deviation between our calculated and some selected experimental energy levels, B(E2) transition rates and the two neutron separation energies S2n. We have also studied the energy ratios and the B(E2) values for the yrast state of the critical nucleus. The nucleon pair transfer intensities between ground-ground and ground-beta states are examined within IBM and boson intrinsic coherent framework.
An algebraic method for solving the SU(3) Gauss law
Salmela, A
2003-01-01
A generalisation of existing SU(2) results is obtained. In particular, the source-free Gauss law for SU(3)-valued gauge fields is solved using a non-Abelian analogue of the Poincare lemma. When sources are present, the colour-electric field is divided into two parts in a way similar to the Hodge decomposition. Singularities due to coinciding eigenvalues of the colour-magnetic field are also analysed.
Fixed point SU(3) gauge actions: scaling properties and glueballs
International Nuclear Information System (INIS)
We present a new parametrization of a SU(3) fixed point (FP) gauge action using smeared ('fat') gauge links. We report on the scaling behaviour of the FP action on coarse lattices by means of the static quark-antiquark potential, the hadronic scale r0, the string tension σ and the critical temperature Tc of the deconfining phase transition. In addition, we investigate the low lying glueball masses where we observe no scaling violations within the statistical errors
Using Wilson flow to study the SU(3) deconfinement transition
Datta, Saumen; Lytle, Andrew
2015-01-01
We explore the use of Wilson flow to study the deconfinement transition in SU(3) gauge theory. We use the flowed Polyakov loop as a renormalized order parameter for the transition, and use it to renormalize the Polyakov loop. We also study the flow properties of the electric and magnetic gluon condensates, and demonstrate that the difference of the flowed operators shows rapid change across the transition point.
Dark Matter from a Classically Scale-Invariant $SU(3)_X$
Karam, Alexandros
2016-01-01
In this work we study a classically scale-invariant extension of the Standard Model in which the dark matter and electroweak scales are generated through the Coleman-Weinberg mechanism. The extra $SU(3)_X$ gauge factor gets completely broken by the vevs of two scalar triplets. Out of the eight resulting massive vector bosons the three lightest are stable due to an intrinsic $Z_2\\times Z_2'$ discrete symmetry and can constitute dark matter candidates. We analyze the phenomenological viability of the predicted multi-Higgs sector imposing theoretical and experimental constraints. We perform a comprehensive analysis of the dark matter predictions of the model solving numerically the set of coupled Boltzmann equations involving all relevant dark matter processes and explore the direct detection prospects of the dark matter candidates.
$SU(3)_{c} X SU(4)_{L} X U(1)_{x}$ model for three families
Sanchez, Luis A; Ponce, W A; Sanchez, Luis A.; Perez, Felipe A.; Ponce, William A.; 10.1140/epjc/s2004-01851-0
2004-01-01
An extension of the Standard Model to the local gauge group $SU(3)_c\\otimes SU(4)_L\\otimes U(1)_X$ as a three-family model is presented. The model does not contain exotic electric charges and we obtain a consistent mass spectrum by introducing an anomaly-free discrete $Z_2$ symmetry. The neutral currents coupled to all neutral vector bosons in the model are studied. By using experimental results from the CERN LEP, SLAC Linear Collider and atomic parity violation we constrain the mixing angle between two of the neutral currents in the model and the mass of the additional neutral gauge bosons to be $-0.0032\\leq\\sin\\theta\\leq 0.0031$ and $0.67 \\hbox{TeV}\\leq M_{Z_2} \\leq 6.1$ TeV at 95% C.L., respectively.
Zuker, A P; Nowacki, F; Lenzi, S
2014-01-01
It is argued that there exist natural shell model spaces optimally adapted to the operation of two variants of Elliott' SU3 symmetry that provide accurate predictions of quadrupole moments of deformed states. A selfconsistent Nilsson-like calculation describes the competition between the realistic quadrupole force and the central field, indicating a {\\em remarkable stability of the quadruplole moments}---which remain close to their quasi and pseudo SU3 values---as the single particle splittings increase. A detailed study of the $N=Z$ even nuclei from $^{56}$Ni to $^{96}$Cd reveals that the region of prolate deformation is bounded by a pair of transitional nuclei $^{72}$Kr and $^{84}$Mo in which prolate ground state bands are predicted to dominate, though coexisting with oblate ones,
The evolution of gauge couplings and the Weinberg angle in 5 dimensions for an SU(3) gauge group
Khojali, Mohammed Omer; Deandrea, Aldo
2016-01-01
We test in a simplified 5-dimensional model with SU(3) gauge symmetry, the evolution equations of the gauge couplings of a model containing bulk fields, gauge fields and one pair of fermions. In this model we assume that the fermion doublet and two singlet fields are located at fixed points of the extra-dimension compactified on an $S^{1}/Z_{2}$ orbifold. The gauge coupling evolution is derived at one-loop in 5-dimensions, for the gauge group $G = SU(3)$, and used to test the impact on lower energy observables, in particular the Weinberg angle. The gauge bosons and the Higgs field arise from the gauge bosons in 5 dimensions, as in a gauge-Higgs model. The model is used as a testing ground as it is not a complete and realistic model for the electroweak interactions.
Improved constraints on chiral SU(3) dynamics from kaonic hydrogen
Ikeda, Yoichi; Weise, Wolfram
2011-01-01
A new improved study of K^- - proton interactions near threshold is performed using coupled-channels dynamics based on the next-to-leading order chiral SU(3) meson-baryon effective Lagrangian. Accurate constraints are now provided by new high-precision kaonic hydrogen measurements. Together with threshold branching ratios and scattering data, these constraints permit an updated analysis of the complex barK N and pi Sigma coupled-channels amplitudes and an improved determination of the K^- p scattering length, including uncertainty estimates.
A simplified SO(6,2) model of SU(3)
International Nuclear Information System (INIS)
A new realization is obtained of the representation of so(6,2) which has been shown recently by Flath and Biedenharn, and also by Bracken and MacGibbon, to define a model of SU(3). In contrast to the realization in terms of six pairs of boson operators used previously, which involved cubic expressions, the new realization involves only quadratic expressions in eight pairs of boson operators, and is manifestly hermitian. Properties of this new ''oscillator realization'', and in particular its advantages over the old realization, are discussed briefly. It is deduced that the representation of so(6,2) is integrable to a unitary group representation. (orig.)
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.
Höllwieser, Roman
2015-01-01
We apply the relative weights method to extract an effective Polyakov line action, at finite chemical potential, from an underlying $SU(3)$ lattice gauge theory with dynamical fermions. The center-symmetry breaking terms in the effective theory are fit to a form suggested by the hopping-parameter expansion, and the effective action is solved at finite chemical potential by a mean field approach. We present preliminary results for one-link staggered fermions with mass $ma=1.0$ and Wilson gauge action at $\\beta=5.4$ on $L^3\\times4$ lattices with $L=16$.
International Nuclear Information System (INIS)
This paper concludes our efforts in describing SU(3)-Yang-Mills theories at different couplings/temperatures in terms of effective Polyakov-loop models. The associated effective couplings are determined through an inverse Monte Carlo procedure based on novel Schwinger-Dyson equations that employ the symmetries of the Haar measure. Because of the first-order nature of the phase transition we encounter a fine-tuning problem in reproducing the correct behavior of the Polyakov-loop from the effective models. The problem remains under control as long as the number of effective couplings is sufficiently small
Deconfinement and chiral symmetry restoration in an SU(3) gauge theory with adjoint fermions
International Nuclear Information System (INIS)
We analyze the finite temperature phase diagram of QCD with fermions in the adjoint representation. The simulations performed with four dynamical Majorana fermions show that the deconfinement and chiral phase transitions occur at two distinct temperatures. While the deconfinement transition is first-order at Td we find evidence for a continuous chiral transition at a higher temperature Tc ≅ 8 Td. We observe a rapid change of bulk thermodynamic observables at Td which reflects the increase in the number of degrees of freedom. However, these show little variation at Tc, where the fermion condensate vanishes. We also analyze the potential between static fundamental and adjoint charges in all three phases and extract the corresponding screening masses above Td
Reig, Mario; Vaquera-Araujo, C A
2016-01-01
Here we propose a realistic $\\mathrm{SU(3)_c \\otimes SU(3)_L \\otimes U(1)_X}$ electroweak gauge model with enlarged Higgs sector. The scheme allows for the natural implementation of a type-II seesaw mechanism for Dirac neutrinos, while charged lepton and quark masses are reproduced with natural flavor conservation in the scalar sector. The new $\\mathrm{SU(3)_c \\otimes SU(3)_L \\otimes U(1)_X}$ energy scale characterizing neutrino mass generation could be accessible to the current LHC experiments.
$SU(3)_{C}\\otimes SU(3)_{L}\\otimes U(1)_{X}$ models in view of the 750 GeV diphoton signal
Martinez, R; Sierra, C F
2016-01-01
We analyze the recent diphoton signal reported by ATLAS and CMS collaborations in the context of the $SU(3)_{C}\\otimes SU(3)_{L}\\otimes U(1)_{X}$ anomaly free models , with a 750 GeV scalar candidate which can decay into two photons. This models may explain the 750GeV signal by means of one loop decays to $\\gamma\\gamma$ through both charged vector and charged Higgs bosons, as well as top-, bottom- and electron-like exotic particles that arise naturally from the condition of anomalies cancellation of the $SU(3)_{C}\\otimes SU(3)_{L}\\otimes U(1)_{X}$ models.
Disoriented chiral condensate dynamics with the SU(3) linear sigma model
International Nuclear Information System (INIS)
The SU(3) extension of the linear sigma model is employed to elucidate the effect of including strangeness on the formation of disoriented chiral condensates. By means of a Hartree factorization, approximate dispersion relations for the 18 scalar and pseudoscalar meson species are derived and their self-consistent solution makes it possible to trace out the thermal path of the two order parameters as well as delineate the region of instability within which spontaneous pair creation becomes possible. The results depend significantly on the employed sigma mass, with the highest values yielding the largest regions of instability. An approximate solution of the equations of motion for the order parameter in scenarios emulating uniform scaling expansions show that even with a rapid quench only the pionic modes grow unstable. Nevertheless, the rapid and oscillatory relaxation of the order parameters leads to enhanced production of both pions and (to a lesser degree) kaons. copyright 1999 The American Physical Society
Superdeformations and fermion dynamical symmetries
International Nuclear Information System (INIS)
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 SU3 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 SU3 fermion dynamical symmetry. Many recently discovered feature of superdeformation are found to be inherent in such an SU3 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
Bilarge neutrino mixing and μ-τ permutation symmetry for two-loop radiative mechanism
International Nuclear Information System (INIS)
The presence of approximate electron number conservation and μ-τ permutation symmetry of S2 is shown to naturally provide bilarge neutrino mixing. First, the bimaximal neutrino mixing together with Ue3=0 is guaranteed to appear owing to S2, and then, the bilarge neutrino mixing together with |Ue3|2. The observed mass hierarchy of Δm·2 atm2 is subject to another tiny violation of the electron number conservation. This scenario is realized in a specific model based on SU(3)LxU(1)N with two-loop radiative mechanism for neutrino masses. The radiative effects from heavy leptons contained in lepton triplets generate the bimaximal structure, and those from charged leptons, which break S2, generate the bilarge structure together with vertical bar Ue3 vertical bar 2 symmetry is extended to a discrete Z8 symmetry, which also ensures the absence of a one-loop radiative mechanism
Topological susceptibility near Tc in SU(3 gauge theory
Directory of Open Access Journals (Sweden)
Guang-Yi Xiong
2016-01-01
Full Text Available Topological charge susceptibility χt for pure gauge SU(3 theory at finite temperature is studied using anisotropic lattices. The over-improved stout-link smoothing method is utilized to calculate the topological charge. Near the phase transition point we find a rapid declining behavior for χt with values decreasing from (188(1 MeV4 to (67(3 MeV4 as the temperature increased from zero temperature to 1.9Tc which demonstrates the existence of topological excitations far above Tc. The 4th order cumulant c4 of topological charge, as well as the ratio c4/χt is also investigated. Results of c4 show step-like behavior near Tc while the ratio at high temperature agrees with the value as predicted by the diluted instanton gas model.
IR fixed points in SU(3 gauge theories
Directory of Open Access Journals (Sweden)
K.-I. Ishikawa
2015-09-01
Full Text Available We propose a novel RG method to specify the location of the IR fixed point in lattice gauge theories and apply it to the SU(3 gauge theories with Nf fundamental fermions. It is based on the scaling behavior of the propagator through the RG analysis with a finite IR cutoff, which we cannot remove in the conformal field theories in sharp contrast to the confining theories. The method also enables us to estimate the anomalous mass dimension in the continuum limit at the IR fixed point. We perform the program for Nf=16,12,8 and Nf=7 and indeed identify the location of the IR fixed points in all cases.
Topological susceptibility near Tc in SU(3) gauge theory
Xiong, Guang-Yi; Zhang, Jian-Bo; Chen, Ying; Liu, Chuan; Liu, Yu-Bin; Ma, Jian-Ping
2016-01-01
Topological charge susceptibility χt for pure gauge SU(3) theory at finite temperature is studied using anisotropic lattices. The over-improved stout-link smoothing method is utilized to calculate the topological charge. Near the phase transition point we find a rapid declining behavior for χt with values decreasing from (188 (1) MeV) 4 to (67 (3) MeV) 4 as the temperature increased from zero temperature to 1.9Tc which demonstrates the existence of topological excitations far above Tc. The 4th order cumulant c4 of topological charge, as well as the ratio c4 /χt is also investigated. Results of c4 show step-like behavior near Tc while the ratio at high temperature agrees with the value as predicted by the diluted instanton gas model.
IR fixed points in $SU(3)$ gauge Theories
Ishikawa, K -I; Nakayama, Yu; Yoshie, Y
2015-01-01
We propose a novel RG method to specify the location of the IR fixed point in lattice gauge theories and apply it to the $SU(3)$ gauge theories with $N_f$ fundamental fermions. It is based on the scaling behavior of the propagator through the RG analysis with a finite IR cut-off, which we cannot remove in the conformal field theories in sharp contrast with the confining theories. The method also enables us to estimate the anomalous mass dimension in the continuum limit at the IR fixed point. We perform the program for $N_f=16, 12, 8 $ and $N_f=7$ and indeed identify the location of the IR fixed points in all cases.
SU(3) breaking in hyperon transition vector form factors
International Nuclear Information System (INIS)
We present a calculation of the SU(3)-breaking corrections to the hyperon transition vector form factors to O(p4) in heavy baryon chiral perturbation theory with finite-range regularisation. Both octet and decuplet degrees of freedom are included. We formulate a chiral expansion at the kinematic point Q2=-(MB1-MB2)2, which can be conveniently accessed in lattice QCD. The two unknown low-energy constants at this point are constrained by lattice QCD simulation results for the Σ-→n and Ξ0→Σ+ transition form factors. Hence we determine lattice-informed values of f1 at the physical point. This work constitutes progress towards the precise determination of vertical stroke Vus vertical stroke from hyperon semileptonic decays.
Strange magnetic moments of octet baryons under SU(3) breaking
Institute of Scientific and Technical Information of China (English)
CAO Lu; WANG Biao; CHEN Hong
2012-01-01
Magnetic moments of octet baryons are parameterized to all orders of the flavor SU(3) breaking with the irreducible tensor technique in order to extract the contribution of each flavor quark to the magnetic moments of the octet baryons.The not-yet measured magnetic moment of Σ0 is predicted to be 0.649 μN.Our parameterized forms for the magnetic moments are explicitly flavor-dependent,and hence each flavor component of the magnetic moments can be evaluated directly via the flavor projection operator.It is fouud that the strange magnetic moment of the nucleon is suppressed due to the small isoscalar anomalous magnetic moment of the nucleon.In particular,the strange magnetic form factor of the nucleon turns out to be positive,(G(s)N) (0) =0.428 μN,which is consistent with recent data.
SU(3) breaking in hyperon transition vector form factors
Energy Technology Data Exchange (ETDEWEB)
Shanahan, P.E.; Thomas, A.W.; Young, R.D.; Zanotti, J.M. [ARC Centre of Excellence in Particle Physics at the Terascale, Adelaide (Australia); Centre for the Subatomic Structure of Matter (CSSM), Adelaide, SA (Australia); Adelaide Univ., SA (Australia). Dept. of Physics; Cooke, A.N.; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe (Japan); Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Division; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2015-08-15
We present a calculation of the SU(3)-breaking corrections to the hyperon transition vector form factors to O(p{sup 4}) in heavy baryon chiral perturbation theory with finite-range regularisation. Both octet and decuplet degrees of freedom are included. We formulate a chiral expansion at the kinematic point Q{sup 2}=-(M{sub B{sub 1}}-M{sub B{sub 2}}){sup 2}, which can be conveniently accessed in lattice QCD. The two unknown low-energy constants at this point are constrained by lattice QCD simulation results for the Σ{sup -}→n and Ξ{sup 0}→Σ{sup +} transition form factors. Hence we determine lattice-informed values of f{sub 1} at the physical point. This work constitutes progress towards the precise determination of vertical stroke V{sub us} vertical stroke from hyperon semileptonic decays.
Chiral symmetry and chiral-symmetry breaking
International Nuclear Information System (INIS)
These lectures concern the dynamics of fermions in strong interaction with gauge fields. Systems of fermions coupled by gauge forces have a very rich structure of global symmetries, which are called chiral symmetries. These lectures will focus on the realization of chiral symmetries and the causes and consequences of thier spontaneous breaking. A brief introduction to the basic formalism and concepts of chiral symmetry breaking is given, then some explicit calculations of chiral symmetry breaking in gauge theories are given, treating first parity-invariant and then chiral models. These calculations are meant to be illustrative rather than accurate; they make use of unjustified mathematical approximations which serve to make the physics more clear. Some formal constraints on chiral symmetry breaking are discussed which illuminate and extend the results of our more explicit analysis. Finally, a brief review of the phenomenological theory of chiral symmetry breaking is presented, and some applications of this theory to problems in weak-interaction physics are discussed
Efficacy of the SU(3) scheme for ab initio large-scale calculations beyond the lightest nuclei
Dytrych, T; Launey, K D; Draayer, J P; Vary, J P; Langr, D; Saule, E; Caprio, M A; Catalyurek, U; Sosonkina, M
2016-01-01
We report on the computational characteristics of ab initio nuclear structure calculations in a symmetry-adapted no-core shell model (SA-NCSM) framework. We examine the computational complexity of the current implementation of the SA-NCSM approach, dubbed LSU3shell, by analyzing ab initio results for 6Li and 12C in large harmonic oscillator model spaces and SU(3)-selected subspaces. We demonstrate LSU3shell's strong-scaling properties achieved with highly-parallel methods for computing the many-body matrix elements. Results compare favorably with complete model space calculations and significant memory savings are achieved in physically important applications. In particular, a well-chosen symmetry-adapted basis affords memory savings in calculations of states with a fixed total angular momentum in large model spaces while exactly preserving translational invariance.
Symmetries and Symmetry Breaking
Van Oers, W T H
2003-01-01
In understanding the world of matter, the introduction of symmetry principles following experimentation or using the predictive power of symmetry principles to guide experimentation is most profound. The conservation of energy, linear momentum, angular momentum, charge, and CPT involve fundamental symmetries. All other conservation laws are valid within a restricted subspace of the four interactions: the strong, the electromagnetic, the weak, and the gravitational interaction. In this paper comments are made regarding parity violation in hadronic systems, charge symmetry breaking in two nucleon and few nucleon systems, and time-reversal-invariance in hadronic systems.
Moduli in General $SU(3)$-Structure Heterotic Compactifications
Svanes, Eirik Eik
2014-01-01
In this thesis, we study moduli in compactifications of ten-dimensional heterotic supergravity. We consider supersymmetric compactifications to four-dimensional maximally symmetric space, commonly referred to as the Strominger system. The compact part of space-time $X$ is a six-dimensional manifold of what we refer to as a heterotic $SU(3)$-structure. We show that this system can be put in terms of a holomorphic operator $\\bar D$ on a bundle $\\mathcal{Q}=T^*X\\oplus\\mathrm{End}(TX)\\oplus\\mathrm{End}(V)\\oplus TX$, defined by a series of extensions. We proceed to compute the infinitesimal deformation space of this structure, given by $T\\mathcal{M}=H^{(0,1)}(\\mathcal{Q})$, which constitutes the infinitesimal spectrum of the four-dimensional theory. In doing so, we find an over counting of moduli by $H^{(0,1)}(\\mathrm{End}(TX))$, which can be reinterpreted as $\\mathcal{O}(\\alpha')$ field redefinitions. We next consider non-maximally symmetric domain wall compactifications of the form $M_{10}=M_3\\times Y$, where $M...
Hadronization in the SU(3) Nambu - Jona-Lasinio model
Rehberg, P
1995-01-01
The hadronization process for quarks combining into two mesons, q\\bar q\\to MM' at temperature T is described within the SU(3) Nambu- Jona-Lasinio model with finite current quark masses. Invariant matrix elements, cross-sections and transition rates are calculated to leading order in a 1/N_c expansion. Four independent classes, u\\bar d, u\\bar s, u\\bar u and s\\bar s\\to hadrons are analysed, and the yield is found to be dominated by pion production. Threshold behaviour is determined by the exothermic or endothermic nature of the processes constituting the hadronization class. A strong suppression of transition rates is found at the pionic Mott temperature T_{M\\pi}=212 MeV, at which the pion becomes a resonant state. The mean time for hadronization is calculated to be 2-4 fm/c near the Mott temperature. The calculation of strangeness changing processes indicates that hadronization accounts for a 1% increase in the absolute value of the kaon to pion ratio at T=150 MeV.
Theory of broken gauge symmetry of families
International Nuclear Information System (INIS)
A theoretical scheme is considered, based on the gauge spontaneously-broken SU(3)H symmetry of families. The generation of quark and lepton masses is induced by their mixing with hypothetical superheavy fermions, providing a relationship of the observed mass hierarchy and mixing of quarks and leptons with the structure of horizontal symmetry breaking. The model predicts the existance of invisible axion, being simultaneously familon and Majoron, as well as the existence of neutrino Majorana mass hierarchy
Clusters and the quasi-dynamical symmetry
International Nuclear Information System (INIS)
The possible role of the quasi-dynamical symmetry in nuclear clusterization is discussed. Two particular examples are considered: i) the phases and phase-transitions of some algebraic cluster models, and ii) the clusterization in heavy nuclei. The interrelation of exotic (superdeformed, hyperdeformed) nuclear shapes and cluster-configurations are also investigated both for light, and for heavy nuclei, based on the dynamical and quasi-dynamical SU(3) symmetries, respectively
Properties of single cluster structure of $d^*(2380)$ in chiral SU(3) quark model
Lü, Qi-Fang; Dong, Yu-Bing; Shen, Peng-Nian; Zhang, Zong-Ye
2016-01-01
The structure of $d^*(2380)$ is re-studied with the single cluster structure in the chiral SU(3) quark model which has successfully been employed to explain the scattering and binding behaviors of baryonic systems. The mass and width are explicitly calculated with two types of trial wave functions. The result shows that the $(0s)^6 [6]_{orb}$ configuration is easy to convert to the configuration with the same $[6]_{orb}$ symmetry but $2\\hbar \\omega$ excitation back and forth, however, it is seldom to turn into a two-cluster configuration with a (1s) relative motion in between. The resultant mass and width are about $2394$MeV and $25$MeV, respectively, and the stable size is about $0.75fm$, which are consistent with both the results in the two-cluster configuration calculation and the data measured by the COSY collaboration. It seems that the observed $d^*$ is a six-quark dominated exotic state with a spherical shape and breath mode in the coordinate space. Moreover, if $d^*$ does have $2\\hbar \\omega$ excitati...
Scalar-Quark Systems and Chimera Hadrons in SU(3)_c Lattice QCD
Iida, H; Takahashi, T T
2007-01-01
Light scalar-quarks \\phi (colored scalar particles or idealized diquarks) and their color-singlet hadronic states are studied with quenched SU(3)_c lattice QCD in terms of mass generation in strong interaction without chiral symmetry breaking. We investigate ``scalar-quark mesons'' \\phi^\\dagger \\phi and ``scalar-quark baryons'' \\phi\\phi\\phi which are the bound states of scalar-quarks \\phi. We also investigate the bound states of scalar-quarks \\phi and quarks \\psi, i.e., \\phi^\\dagger \\psi, \\psi\\psi\\phi and \\phi\\phi\\psi, which we name ``chimera hadrons''. All the new-type hadrons including \\phi are found to have a large mass even for zero bare scalar-quark mass m_\\phi=0 at a^{-1}\\simeq 1GeV. We find that the constituent scalar-quark and quark picture is satisfied for all the new-type hadrons. Namely, the mass of the new-type hadron composed of m \\phi's and n \\psi's, M_{{m}\\phi+{n}\\psi}, satisfies M_{{m}\\phi+{n}\\psi}\\simeq {m} M_\\phi +{n} M_\\psi, where M_\\phi and M_\\psi are the constituent scalar-quark and quark...
Empirical Example of Nucleus with Transitional Dynamical Symmetry X(5)
Institute of Scientific and Technical Information of China (English)
张大立; 赵惠英
2002-01-01
By analysing the energy spectrum, E2 transition rates and branching ratios, it is shown explicitly that the nucleus 150Nd provides an empirical example with X(5) symmetry at the critical point of the transition from U(5) to SU(3) symmetry.
Creation and annihilation operators for SU(3) in an SO(6,2) model
International Nuclear Information System (INIS)
Creation and annihilation operators are defined which are Wigner operators (tensor shift operators) for SU(3). While the annihilation operators are simply boson operators, the creation operators are cubic polynomials in boson operators. Together they generate under commutation the Lie algebra of SO(6,2). A model for SU(3) is defined. The different SU(3) irreducible representations appear explicitly as manifestly covariant, irreducible tensors, whose orthogonality and normalisation properties are examined. Other Wigner operators for SU(3) can be constructed simply as products of the new creation and annihilation operators, or sums of such products. (author)
SU(3) magnet: finite-gap integration on the lowest genus curve
International Nuclear Information System (INIS)
We consider the integrable system of isotropic SU(3) Landau-Lifshits equation as a Hamiltonian system on a coadjoint orbit of the SU(3) loop group. We connect the mentioned equation with an isotropic SU(3) magnet because it describes the mean fields of magnetic and quadrupole moments in a spin-1 lattice. For the system of isotropic SU(3) Landau-Lifshits equation we perform separation of variables in Sklyanin's manner, and integrate in the lowest finite gap where the spectral curve is elliptic
An approach to permutation symmetry for the electroweak theory
Jora, R; Schechter, J; Jora, Renata; Nasri, Salah; Schechter, Joseph
2006-01-01
The form of the leptonic mixing matrix emerging from experiment has, in the last few years, generated a lot of interest in the so-called tribimaximal type. This form may be naturally associated with the possibility of a discrete permutation symmetry ($S_3$) among the three generations. However, trying to implement this attractive symmetry has resulted in some problems and it seems to have fallen out of favor. We suggest an approach in which the $S_3$ holds to first approximation, somewhat in the manner of the old SU(3) flavor symmetry of the three flavor quark model. We discuss the nature of the perturbations which are the analogs of the Gell-Mann Okubo perturbations in the above case but confine our attention for the most part to the $S_3$ invariant model. We postulate that the $S_3$ invariant mass spectrum consists of non zero masses for the $(\\tau,b,t)$ and zero masses for the other charged fermions but approximately degenerate masses for the three neutrinos. The mixing matrices are assumed to be trivial f...
Quantum mechanics. Symmetries. 5. corr. ed.
International Nuclear Information System (INIS)
The volume quantum mechanics treats the as elegant as mighty theory of the symmetry groups and their application in quantum mechanics and the theory of the elementary particles. By means of many examples and problems with worked-out solutions the application of the fundamental principles to realistic problems is elucidated. The themes are symmetries in quantum mechanics, representations of the algebra of the angular momentum operators as generators of the SO(3) group. fundamental properties of Lie groups as mathematical supplement, symmetry groups and their physical meaning, thr isospin group, the hypercharge, quarks and the symmetry group SU(3), representations of the permutation group and Young diagrams, group characters as mathematical supplement, charm and the symmetry group SU(4), Cartan-Weyl claasification as mathematical supplement, special discrete symmetries, dynamical symmetries and the hydrogen atom, non-compact Lie groups as mathematical supplement, a proof of Racah's theorem.
The SU(3)/Z_3 QCD(adj) deconfinement transition via the gauge theory/"affine" XY-model duality
Anber, Mohamed M; Poppitz, Erich
2012-01-01
Earlier, two of us and M. Unsal [arXiv:1112.6389] showed that some 4d gauge theories, compactified on a small spatial circle of size L and considered at temperatures 1/beta near deconfinement, are dual to 2d "affine" XY-spin models. We use the duality to study deconfinement in SU(3)/Z_3 theories with n_f>1 massless adjoint Weyl fermions, QCD(adj) on R^2 x S^1_beta x S^1_L. The"affine" XY-model describes two "spins" - compact scalars taking values in the SU(3) root lattice, with nearest-neighbor interactions and subject to an "external field" preserving the topological Z_3^t and a discrete Z_3^chi subgroup of the chiral symmetry of the 4d gauge theory. The equivalent Coulomb gas representation of the theory exhibits electric-magnetic duality, which is also a high-/low-temperature duality. A renormalization group analysis suggests - but is not convincing, due to the onset of strong coupling - that the self-dual point is a fixed point, implying a continuous deconfinement transition. Here, we study the nature of ...
Notes on TQFT wire models and coherence equations for SU(3) triangular cells
Coquereaux, R; Schieber, G
2010-01-01
After a summary of the TQFT wire model formalism we bridge the gap from Kuperberg equations for SU(3) spiders to Ocneanu coherence equations for systems of triangular cells on fusion graphs that describe modules associated with the fusion category of SU(3) at level k. We show how to solve these equations in a number of examples.
Algebraic Bethe ansatz for scalar products in SU(3)-invariant integrable models
Belliard, S; Ragoucy, E; Slavnov, N A
2012-01-01
We study SU(3)-invariant integrable models solvable by nested algebraic Bethe ansatz. We obtain a determinant representation for particular case of scalar products of Bethe vectors. This representation can be used for the calculation of form factors and correlation functions of XXX SU(3)-invariant Heisenberg chain.
The role of SU(2) 3n-j coefficients in SU(3)
International Nuclear Information System (INIS)
The irreducible representations of the group SU(3) may be given completely in terms of the 3-j, 6-j, and 9-j coefficients of SU(2). More remarkably these same coefficients, and the 12-j coefficients as well, enter into the description of a large class of Clebsch-Gordan (C-G) coefficients for the group SU(3), this occurrence going beyond that in the well-known group-subgroup reduction SU(3)↓U(2). The problem of determining the SU(3) irreducible representations and its C-G coefficients is reviewed, and it is shown how the SU(2) quantities enter into the SU(3) problem in special cases
Spinor Structure and Internal Symmetries
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.
Strong coupling and quasispinor representations of the SU(3) rotor model
International Nuclear Information System (INIS)
We define a coupling scheme, in close parallel to the coupling scheme of Elliott and Wilsdon, in which nucleonic intrinsic spins are strongly coupled to SU(3) spatial wave functions. The scheme is proposed for shell-model calculations in strongly deformed nuclei and for semimicroscopic analyses of rotations in odd-mass nuclei and other nuclei for which the spin-orbit interaction is believed to play an important role. The coupling scheme extends the domain of utility of the SU(3) model, and the symplectic model, to heavy nuclei and odd-mass nuclei. It is based on the observation that the low angular-momentum states of an SU(3) irrep have properties that mimic those of a corresponding irrep of the rotor algebra. Thus, we show that strongly coupled spin-SU(3) bands behave like strongly coupled rotor bands with properties that approach those of irreducible representations of the rigid-rotor algebra in the limit of large SU(3) quantum numbers. Moreover, we determine that the low angular-momentum states of a strongly coupled band of states of half-odd integer angular momentum behave to a high degree of accuracy as if they belonged to an SU(3) irrep. These are the quasispinor SU(3) irreps referred to in the title. (orig.)
Karsch, F.; Laermann, E.; Lütgemeier, M.
1994-01-01
We establish a close relation between the spatial string tension of the (3+1)-dimensional $SU(3)$ gauge theory at finite temperature ($\\sigma_s$) and the string tension of the 3-dimensional $SU(3)$ gauge theory ($\\sigma_3$) which is similar to what has been found previously for $SU(2)$. We obtain $\\sqrt{\\sigma_3} = (0.554 \\pm 0.004) g_3^2$ and $\\sqrt{\\sigma_s} = (0.586 \\pm 0.045)g^2(T) T$, respectively. For temperatures larger than twice the critical temperature results are consistent with a ...
On SU(3) effective models and chiral phase-transition
Tawfik, Abdel Nasser
2015-01-01
The sensitivity of Polyakov Nambu-Jona-Lasinio (PNJL) model as an effective theory of quark dynamics to chiral symmetry has been utilized in studying the QCD phase-diagram. Also, Poyakov linear sigma-model (PLSM), in which information about the confining glue sector of the theory was included through Polyakov-loop potential. Furthermore, from quasi-particle model (QPM), the gluonic sector of QPM is integrated to LSM in order to reproduce recent lattice calculations. We review PLSM, QLSM, PNJL and HRG with respect to their descriptions for the chiral phase-transition. We analyse chiral order-parameter M(T), normalized net-strange condensate Delta_{q,s}(T) and chiral phase-diagram and compare the results with lattice QCD. We conclude that PLSM works perfectly in reproducing M(T) and Delta_{q,s}(T). HRG model reproduces Delta_{q,s}(T), while PNJL and QLSM seem to fail. These differences are present in QCD chiral phase-diagram. PLSM chiral boundary is located in upper band of lattice QCD calculations and agree we...
Charge independence and charge symmetry
Miller, G A; Miller, Gerald A; van Oers, Willem T H
1994-01-01
Charge independence and charge symmetry are approximate symmetries of nature, violated by the perturbing effects of the mass difference between up and down quarks and by electromagnetic interactions. The observations of the symmetry breaking effects in nuclear and particle physics and the implications of those effects are reviewed.
Charge independence and charge symmetry
International Nuclear Information System (INIS)
Charge independence and charge symmetry are approximate symmetries of nature, violated by the perturbing effects of the mass difference between up and down quarks and by electromagnetic interactions. The observations of the symmetry breaking effects in nuclear and particle physics and the implications of those effects are reviewed. (author). 145 refs., 3 tabs., 11 figs
△△ Dibaryon Structure in Extended Chiral SU(3) Quark Model
Institute of Scientific and Technical Information of China (English)
DAI Lian-Rong
2005-01-01
@@ The structure of △△ dibaryon is studied in the extended chiral SU(3) quark model in which vector meson exchanges are included. The effect of the vector meson fields is very similar to that of the one-gluon exchange (OGE) interaction. Both in the chiral SU(3) quark model and in the extended chiral SU(3) quark model, the resultant mass of the △△ dibaryon is lower than the threshold of the △△ channel but higher than that of the△Nπ channel.
Ocneanu Cells and Boltzmann Weights for the SU(3) ADE Graphs
Evans, David E
2009-01-01
We determine the cells, whose existence has been announced by Ocneanu, on all the candidate nimrep graphs except $\\mathcal{E}_4^{(12)}$ proposed by di Francesco and Zuber for the SU(3) modular invariants classified by Gannon. This enables the Boltzmann weights to be computed for the corresponding integrable statistical mechanical models and provide the framework for studying corresponding braided subfactors to realise all the SU(3) modular invariants as well as a framework for a new SU(3) planar algebra theory.
Quasi-integrable deformations of the SU(3) Affine Toda theory
Ferreira, L. A.; Klimas, P.; Zakrzewski, Wojtek J.
2016-05-01
We consider deformations of the SU(3) Affine Toda theory (AT) and investigate the integrability properties of the deformed theories. We find that for some special deformations all conserved quantities change to being conserved only asymptotically, i.e. in the process of the scattering of two solitons these charges do vary in time, but they return, after the scattering, to the values they had prior to the scattering. This phenomenon, which we have called quasi-integrability, is related to special properties of the two-soliton solutions under space-time parity transformations. Some properties of the AT solitons are discussed, especially those involving interesting static multi-soliton solutions. We support our analytical studies with detailed numerical ones in which the time evolution has been simulated by the 4th order Runge-Kutta method. We find that for some perturbations the solitons repel and for the others they form a quasi-bound state. When we send solitons towards each other they can repel when they come close together with or without `flipping' the fields of the model. The solitons radiate very little and appear to be stable. These results support the ideas of quasi-integrability, i.e. that many effects of integrability also approximately hold for the deformed models.
A 125 GeV Scalar Boson and SU(N_{TC})\\otimes SU(3)_{{}_{L}}\\otimes U(1)_{{}_{X}} models
Doff, A.(Universidade Tecnológica Federal do Paraná – UTFPR – DAFIS, Av. Monteiro Lobato Km 04, 84016-210 Ponta Grossa, PR, Brazil); Natale, A. A.
2013-01-01
We verify that SU(N)_{{}_{TC}}\\otimes SU(3)_{{}_{L}}\\otimes U(1)_{{}_{X}} models, where the gauge symmetry breaking is totally dynamical and promoted by the non-Abelian technicolor (TC) group and the strong Abelian interactions, are quite constrained by the LHC data. The theory contains a T quark self-energy involving the mixing between the neutral gauge bosons, which introduces the coupling between the light and heavy composite scalar bosons of the model. We determine the lightest scalar bos...
Quarks and the Poincare group: SU(6) x SU(3) as a classification group for baryons
International Nuclear Information System (INIS)
The description of baryons as a three quark system results in an irreducible unitary representation of the Poincare group. Starting from this description collinear baryon states can be classified within the SU(6) x SU(3) group. (WL)
Chiral symmetry and chiral-symmetry breaking
Energy Technology Data Exchange (ETDEWEB)
Peskin, M.E.
1982-12-01
These lectures concern the dynamics of fermions in strong interaction with gauge fields. Systems of fermions coupled by gauge forces have a very rich structure of global symmetries, which are called chiral symmetries. These lectures will focus on the realization of chiral symmetries and the causes and consequences of thier spontaneous breaking. A brief introduction to the basic formalism and concepts of chiral symmetry breaking is given, then some explicit calculations of chiral symmetry breaking in gauge theories are given, treating first parity-invariant and then chiral models. These calculations are meant to be illustrative rather than accurate; they make use of unjustified mathematical approximations which serve to make the physics more clear. Some formal constraints on chiral symmetry breaking are discussed which illuminate and extend the results of our more explicit analysis. Finally, a brief review of the phenomenological theory of chiral symmetry breaking is presented, and some applications of this theory to problems in weak-interaction physics are discussed. (WHK)
Energy Technology Data Exchange (ETDEWEB)
Kremer, Christoph
2016-01-27
The first part of this thesis revolves around symmetries in the sd-IBA-1. A region of approximate O(6) symmetry for the ground-state band, a partial dynamical symmetry (PDS) of type III, in the parameter space of the extended consistent-Q formalism is identified through quantum number fluctuations. The simultaneous occurrence of a SU(3) quasi dynamical symmetry for nuclei in the region of O(6) PDS is explained via the β=1, γ=0 intrinsic state underlying the ground-state band. The previously unrelated concepts of PDS and QDS are connected for the first time and many nuclei in the rare earth region that approximately satisfy both symmetry requirements are identified. Ground-state to ground-state (p, t) transfer reactions are presented as an experimental signature to identify pairs of nuclei that both exhibit O(6) PDS. In the second part of this thesis inelastic electron scattering off {sup 96}Zr is studied. The experiment was performed at the high resolution Lintott spectrometer at the S-DALINAC and covered a momentum-transfer range of 0.28 - 0.59 fm{sup -1}. Through a relative analysis using Plane Wave Born Approximation (PWBA) the B(E2;2{sup +}{sub 2}→0{sup +}{sub 1}) value is extracted without incurring the additional model dependence of a Distorted Wave Born Approximation (DWBA). By combining this result with known multipole mixing ratios and branching ratios all decay strengths of the 2{sup +}{sub 2} state are determined. A mixing calculation establishes very weak mixing (V{sub mix}=76 keV) between states of the ground-state band and those of the band build on top of the 0{sup +}{sub 2} state which includes the 2{sup +}{sub 2} state. The occurrence of these two isolated bands is interpreted within the shell model in terms of type II shell evolution.
A new procedure for constructing basis vectors of SU(3)⊃SO(3)
Pan, Feng; Yuan, Shuli; Launey, Kristina D.; Draayer, Jerry P.
2016-08-01
A simple and effective algebraic angular momentum projection procedure for constructing basis vectors of SU (3) ⊃ SO (3) ⊃ SO (2) from the canonical U (3) ⊃ U (2) ⊃ U (1) basis vectors is outlined. The expansion coefficients are components of the null-space vectors of a projection matrix with, in general, four nonzero elements in each row, where the projection matrix is derived from known matrix elements of the U (3) generators in the canonical basis. The advantage of the new procedure lies in the fact that the Hill-Wheeler integral involved in the Elliott's projection operator method used previously is avoided, thereby achieving faster numerical calculations with improved accuracy. Selected analytical expressions of the expansion coefficients for the SU (3) irreps [n13 ,n23 ], or equally, (λ , μ) = (n13 -n23 ,n23) with λ and μ the SU (3) labels familiar from the Elliott model, are presented as examples for n23 ≤ 4. Explicit formulae for evaluating SO (3)-reduced matrix elements of SU (3) generators are derived. A general formula for evaluating the SU (3) ⊃ SO (3) Wigner coefficients is given, which is expressed in terms of the expansion coefficients and known U (3) ⊃ U (2) and U (2) ⊃ U (1) Wigner coefficients. Formulae for evaluating the elementary Wigner coefficients of SU (3) ⊃ SO (3), i.e., for the SU (3) coupling [n13 ,n23 ] ⊗ [ 1 , 0 ], are explicitly given with some analytical examples shown to check the validity of the results. However, the Gram-Schmidt orthonormalization is still needed in order to provide orthonormalized basis vectors.
Non-Kaehler SYZ mirror symmetry
Lau, Siu-Cheong; Yau, Shing-Tung
2014-01-01
We study SYZ mirror symmetry in the context of non-Kaehler Calabi-Yau manifolds. In particular, we study the six-dimensional Type II supersymmetric $SU(3)$ systems with Ramond-Ramond fluxes, and generalized them to higher dimensions. We show that Fourier-Mukai transform provides the mirror map between these Type IIA and Type IIB supersymmetric systems in the semi-flat setting. This is concretely exhibited by nilmanifolds.
Diffeomorphism symmetry in quantum gravity models
Dittrich, Bianca
2008-01-01
We review and discuss the role of diffeomorphism symmetry in quantum gravity models. Such models often involve a discretization of the space-time manifold as a regularization method. Generically this leads to a breaking of the symmetries to approximate ones, however there are incidences in which the symmetries are exactly preserved. Both kind of symmetries have to be taken into account in covariant and canonical theories in order to ensure the correct continuum limit. We will sketch how to identify exact and approximate symmetries in the action and how to define a corresponding canonical theory in which such symmetries are reflected as exact and approximate constraints.
Intermediate Symmetries in the Spontaneous Breaking of Supersymmetric SO(10)
Buccella, F.; Savoy, C.A.
2002-01-01
We study the supersymmetric spontaneous symmetry breaking of SO(10) into SU(3)xSU(2)xU(1) for the most physically interesting cases of SU(5) or flipped SU(5)xU(1) intermediate symmetries. The first case is more easily realized while the second one requires a fine-tuning condition on the parameters of the superpotential. This is because in the case of SU(5) symmetry there is at most one singlet of the residual symmetry in each SO(10) irreducible representation. We also point out on more genera...
Lepton-flavor-changing processes and CP violation in the SU(3)cxSU(3)LxU(1)X model
International Nuclear Information System (INIS)
By extending the electroweak gauge group to SU(3)LxU(1)Y, the SU(3)cxSU(3)LxU(1)X (3-3-1) dilepton gauge bosons Y which do not respect individual lepton family number. We point out that, in addition to family diagonal couplings such as Y-e-e that change the lepton family number by two uinits, dileptons may also have family nondiagonal couplings such as Y-μ-e. The latter coupling violates lepton family number by a single unit and manifests itself via lepton-flavor-changing decays such as μ→3e and μ→eγ. The family nondiagonal interaction can be CP violating and typically generates an extremely large leptonic electric dipole moment. We demonstrate a natural mechanism for eliminating both single unit lepton-flavor violation and large leptonic CP violation. Although we focus on the 3-3-1 model, our results are applicable to other dilepton models as well, including SU(15) grand unification
Z-Z' Mixing and Z-Mediated FCNCs in SU(3)_C x SU(3)_L x U(1)_X Models
Buras, Andrzej J; Girrbach-Noe, Jennifer
2014-01-01
Most of the existing analyses of FCNC processes in the 331 models, based on the gauge group SU(3)_C x SU(3)_L x U(1)_X, take only into account tree-level exchanges of a new heavy neutral gauge boson Z'. However due to the Z-Z' mixing also corresponding contributions from Z boson are present that are usually neglected. We calculate the impact of these contributions on Delta F=2 processes and rare K, B_s and B_d decays for different values of a parameter beta, which distinguishes between various 331 models and for different fermion representations under the SU(3)_L group. We find a general expression for the Z-Z' mixing in terms beta, M_Z, M_Z' and tan(bar{beta}), familiar from 2 Higgs Doublet models, that differs from the one quoted in the literature. We study in particular the models with beta=+-n/sqrt{3} with n=1,2 which have recently been investigated by us in the context of new data on B_{s,d}->mu^+ mu^- and B_d->K^*(K)mu^+ mu^-. We find that these new contributions can indeed be neglected in the case of D...
AdS/dCFT one-point functions of the SU(3) sector
de Leeuw, Marius; Mori, Stefano
2016-01-01
We propose a closed formula for the tree-level one-point functions of non-protected operators belonging to an SU(3) sub-sector of the defect CFT dual to the D3-D5 probe brane system with background gauge field flux, k, valid for k=2. The formula passes a number of non-trivial analytical and numerical tests. Our proposal is based on expressing the one-point functions as an overlap between a Bethe eigenstate of the SU(3) spin chain and a certain matrix product state, deriving various factorization properties of the Gaudin norm and performing explicit computations for shorter spin chains. As its SU(2) counterpart, the one-point function formula for the SU(3) sub-sector is of determinant type. We discuss the the differences with the SU(2) case and the challenges in extending the present formula beyond k=2.
The Polyakov loop and its correlators in higher representations of SU(3) at finite temperature
Energy Technology Data Exchange (ETDEWEB)
Huebner, K.A.
2006-09-15
We have calculated the Polyakov loop in representations D=3,6,8,10,15,15',24,27 and diquark and baryonic Polyakov loop correlation functions with fundamental sources in SU(3) pure gauge theory and 2-flavour QCD with staggered quarks and Q anti Q-singlet correlation functions with sources in the fundamental and adjoint representation in SU(3) pure gauge theory. We have tested a new renormalisation procedure for the Polyakov loop and extracted the adjoint Polyakov loop below T{sub c}, binding energy of the gluelump and string breaking distances. Moreover, we could show Casimir scaling for the Polyakov loop in different representations in SU(3) pure gauge theory above T{sub c}. Diquark antitriplet and baryonic singlet free energies are related to the Q anti Q-singlet free energies by the Casimir as well. (orig.)
The Polyakov loop and its correlators in higher representations of SU(3) at finite temperature
International Nuclear Information System (INIS)
We have calculated the Polyakov loop in representations D=3,6,8,10,15,15',24,27 and diquark and baryonic Polyakov loop correlation functions with fundamental sources in SU(3) pure gauge theory and 2-flavour QCD with staggered quarks and Q anti Q-singlet correlation functions with sources in the fundamental and adjoint representation in SU(3) pure gauge theory. We have tested a new renormalisation procedure for the Polyakov loop and extracted the adjoint Polyakov loop below Tc, binding energy of the gluelump and string breaking distances. Moreover, we could show Casimir scaling for the Polyakov loop in different representations in SU(3) pure gauge theory above Tc. Diquark antitriplet and baryonic singlet free energies are related to the Q anti Q-singlet free energies by the Casimir as well. (orig.)
Lattice study for conformal windows of SU(2) and SU(3) gauge theories with fundamental fermions
Huang, Cynthia Y -H; Lin, C -J David; Ogawa, Kenji; Ohki, Hiroshi; Ramos, Alberto; Rinaldi, Enrico
2015-01-01
We present our investigation of SU(2) gauge theory with 8 flavours, and SU(3) gauge theory with 12 flavours. For the SU(2) case, at strong bare coupling, $\\beta \\lesssim 1.45$, the distribution of the lowest eigenvalue of the Dirac operator can be described by chiral random matrix theory for the Gaussian symplectic ensemble. Our preliminary result indicates that the chiral phase transition in this theory is of bulk nature. For the SU(3) theory, we use high-precision lattice data to perform the step-scaling study of the coupling, $g_{{\\rm GF}}$, in the Gradient Flow scheme. We carefully examine the reliability of the continuum extrapolation in the analysis, and conclude that the scaling behaviour of this SU(3) theory is not governed by possible infrared conformality at $g_{{\\rm GF}}^{2} \\lesssim 6$.
The Spectrum of the Baryon Masses in a Self-consistent SU(3) Quantum Skyrme Model
Jurciukonis, Darius; Regelskis, Vidas
2012-01-01
The semiclassical SU(3) Skyrme model is traditionally considered as describing a rigid quantum rotator with the profile function being fixed by the classical solution of the corresponding SU(2) Skyrme model. In contrast, we go beyond the classical profile function by quantizing the SU(3) Skyrme model canonically. The quantization of the model is performed in terms of the collective coordinate formalism and leads to the establishment of purely quantum corrections of the model. These new corrections are of fundamental importance. They are crucial in obtaining stable quantum solitons of the quantum SU(3) Skyrme model, thus making the model self-consistent and not dependent on the classical solution of the SU(2) case. We show that such a treatment of the model leads to a family of stable quantum solitons that describe the baryon octet and decuplet and reproduce the experimental values of their masses.
Dynamical symmetries of the shell model
International Nuclear Information System (INIS)
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)
Dynamical symmetries of the shell model
Energy Technology Data Exchange (ETDEWEB)
Van Isacker, P
2000-07-01
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)
The Polyakov loop and its correlators in higher representations of SU(3) at finite temperature
Hübner, Kay A.
2006-01-01
We have calculated the Polyakov loop in representations D=3,6,8,10,15a,15s,24,27 and diquark and baryonic Polyakov loop correlation functions with fundamental sources in SU(3) pure gauge theory and 2-flavour QCD with staggered quarks and Qbar Q-singlet correlation functions with sources in the fundamental and adjoint representation in SU(3) pure gauge theory. We have tested a new renormalisation procedure for the Polyakov loop and extracted the adjoint Polyakov loop below T_c, binding energy ...
SU(3)-instantons and G2, Spin (7)-heterotic string solitons
International Nuclear Information System (INIS)
Necessary and sufficient conditions to the existence of a hermitian connection with totally skew-symmetric torsion and holonomy contained in SU(3) are given. A formula for the Riemannian scalar curvature is obtained. Nonconformally flat solutions to the supergravity-type I equations of motion with non-zero flux and non-constant dilaton are found in dimensions 6, 7 and 8. A Riemannian metric with holonomy contained in G2 arose from our solution and Hitchin's flow equations, which seems to be new. Compact examples of SU(3), G2 and Spin(7) instanton satisfying the anomaly cancellation conditions are presented. (author)
Bosonization of the generalized SU(3) Nambu-Jona-Lasinio model in the 1/N expansion
International Nuclear Information System (INIS)
The present work consists in a 1/N expansion of extended version of the SU(3) Nambu-Jona-Lasinio model in the context of the Functional Integral. The gap equations, meson propagators, triangle diagram, etc, appear quite naturally as different orders in the expansion. The new features of this approach is the inclusion of high order corrections in the 1/N leading orders, which have never included in the previous one. The method also allows for the construction of a chiral Lagrangian of interacting mesons based on the SU(3) NJL model, here obtained for the first time. (author)
Unconstrained SU(2) and SU(3) Yang-Mills classical mechanics
International Nuclear Information System (INIS)
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.)
$\\Delta(27)$ family symmetry and neutrino mixing
Varzielas, Ivo de Medeiros
2015-01-01
The observed neutrino mixing, having a near maximal atmospheric neutrino mixing angle and a large solar mixing angle, is close to tri-bi-maximal. This structure may be related to the existence of a discrete non-Abelian family symmetry. In this paper the family symmetry is the non-Abelian discrete group $\\Delta(27)$, a subgroup of $SU(3)$ with triplet and anti-triplet representations. Different frameworks are constructed in which the mixing follows from combining fermion mass terms with the vacuum structure enforced by the discrete symmetry. Mass terms for the fermions originate from familon triplets, anti-triplets or both. Vacuum alignment for the family symmetry breaking familons follows from simple invariants.
International Nuclear Information System (INIS)
We calculate the glueball mass spectrum in the SU(3) lattice regularized gauge theory. We find four light glueballs: the 0++, 2++, 0-+, and, most interestingly from the experimental point of view, the oddball 1-+. We calculate the 0++ and 2++ masses over a range of β values and find that both states conform to continuum renormalization group behaviour to a very significant degree. The question of metastable states and temperature is addressed in detail. Finally we discuss and resolve contrary claims in the recent literature. (orig.)
Macroscopic limit of the microscopic SU(3)containsSO(3) integrity basis interaction
International Nuclear Information System (INIS)
It is shown that a fourth degree SU(3)containsSO(3) integrity basis interaction, encountered in both fermion and boson theories of nuclear structure, maps onto an axially symmetric rotor Hamiltonian for a special linear combination of the third (LQL) and fourth (LQQL) order scalar operators
Monte Carlo Renormalization Group study for SU(3) lattice gauge theory
International Nuclear Information System (INIS)
A special Monte Carlo Renormalization Group method, the so-called ratio method is discussed. Possible systematic error of the method is investigated, and a systematic improvement is proposed based on perturbation theory. The method is applied to determine the β-function of 4 dimensional SU(3) pure gauge theory
Invariant Differential Operators for Non-Compact Lie Groups: the Reduced SU(3,3) Multiplets
Dobrev, V K
2013-01-01
In the present paper we continue the project of systematic construction of invariant differential operators on the example of the non-compact algebras $su(n,n)$. Earlier were given the main multiplets of indecomposable elementary representations for $n\\leq 4$, and the reduced ones for $n=2$. Here we give the reduced multiplets for the algebra $su(3,3)$.
SU (3) realization of the rigid asymmetric rotor within the IBM
International Nuclear Information System (INIS)
It is shown that the spectrum of the asymmetric rotor can be realized quantum mechanically in terms of a system of interacting bosons. This is achieved in the SU(3) limit of the interacting boson model by considering higher-order interactions between the bosons. The spectrum corresponds to that of a rigid asymmetric rotor in the limit of infinite boson number. (author)
Splitting the spectral flow and the SU(3) Casson invariant for spliced sums
DEFF Research Database (Denmark)
Boden, Hans U.; Himpel, Benjamin
2009-01-01
We show that the SU(3) Casson invariant for spliced sums along certain torus knots equals 16 times the product of their SU(2) Casson knot invariants. The key step is a splitting formula for su(n) spectral flow for closed 3–manifolds split along a torus....
London penetration depth and coherence length of SU(3) vacuum flux tubes
Cea, Paolo; Cosmai, Leonardo; Cuteri, Francesca; Papa, Alessandro
2014-01-01
The transverse profile of the chromoelectric field generated by a quark-antiquark pair in the SU(3) vacuum is analysed within the dual superconductor scenario, then the London penetration depth and coherence length are extracted. The color field is determined on the lattice through a connected correlator of two Polyakov loops measured on smeared configurations.
Weak-coupling universality in SU(3) mixed actions: Theory versus high-statistics simulation
International Nuclear Information System (INIS)
Predictions of weak-coupling universality and high-statistics simulations on the string tension of SU(3) do disagree beyond the statistical error. This disagreement is larger for the conventional two-loop universality formula than for the self-consistent large-N expression. Various ways out are suggested
The spin-orbit interaction and SU(3) generators in superdeformation
International Nuclear Information System (INIS)
We found that the effect of the spin-orbit coupling force becomes smaller for the parity doublet levels and for some other levels around superdeformation. This is because of the strongly deformed quadrupole field, which indicates the L-S coupling scheme is recovered for these level. These levels can be described by SU(3) group with eight generators and Casimir operator. (orig.)
Fortran MPI Checkerboard Code for SU(3) Lattice Gauge Theory II
Berg, Bernd A.; Wu, Hao
2009-01-01
We study the performance of MPI checkerboard code for SU(3) lattice gauge theory as function of the number of MPI processes, which run in parallel on an identical number of CPU cores. Computing platforms explored are a small PC cluster at FSU and the Cray at NERSC.
Family symmetry, fermion mass matrices and cosmic texture
International Nuclear Information System (INIS)
The observed replication of fermions in three families is undoubtedly a reflection of a deeper symmetry underlying the standard model. In this paper we investigate one very elementary possibility, that physics above the grand unification scale is described by the symmetry group G x SU(3)fam with G a gauged grand unified group, and SU(3)fam a global family symmetry. The breaking of this symmetry at the GUT scale produces global texture, providing a mechanism for structure formation in the universe, and sets strong constraints on the low energy fermion mass matrix. With the addition of a 45 Higgs and certain assumptions about the relative strength of Higgs couplings, the simplest SU(5) theory yields an eight-parameter form for the fermion mass matrices, which we show is consistent with the thirteen observable masses and mixing angles. We discuss the natural suppression of flavour-changing neutral currents (FCNCs) and emphasise the rich low energy Higgs sector. With minor assumptions, the theory unifies consistently with the recent LEP data. We consider the extension to G = SO(10), where some simplification and further predictiveness emerges. Finally we discuss the dynamics of SU(3)fam texture and show that the known constraints on unification ''predict'' a GUT symmetry-breaking scale of the order required for cosmic structure formation, and by the recent detection of cosmic microwave anisotropy by COBE. (orig.)
Symmetries and deformations in the spherical shell model
Van Isacker, Piet
2016-01-01
We discuss symmetries of the spherical shell model that make contact with the geometric collective model of Bohr and Mottelson. The most celebrated symmetry of this kind is SU(3), which is the basis of Elliott's model of rotation. It corresponds to a deformed mean field induced by a quadrupole interaction in a single major oscillator shell N and can be generalized to include several major shells. As such, Elliott's SU(3) model establishes the link between the spherical shell model and the (quadrupole component of the) geometric collective model. We introduce the analogue symmetry induced by an octupole interaction in two major oscillator shells N-1 and N, leading to an octupole-deformed solution of the spherical shell model. We show that in the limit of large oscillator shells (large N) the algebraic octupole interaction tends to that of the geometric collective model.
Symmetry relation for helical plasmas: parity symmetry
International Nuclear Information System (INIS)
It is shown that a symmetry relation holds strictly in the LHD (Large Helical Device) type helical magnetic fields. The symmetry relation can be expressed explicitly in the rotating helical coordinate system. It is named as parity symmetry in helical systems. A new concept, - concept of even scalars, odd scalars, even vectors, odd vectors -, is introduced. Calculus of vector operation retains strictly the parity relations for these quantities. For example, the vector product of two vectors with same parity become a odd parity vector. The rotation of a vector field A, ∇ x A, has same parity characteristics with the vector A. It is concluded that the equilibrium magnetic field and current distribution are expressed by even parity vectors. Pressure distribution is expressed by an even parity scalar function. The parity symmetry relations conduct uniquely the power expansion form of equilibrium magnetic field and pressure distribution. Analytical expression for these quantities are obtained approximately by truncation of the power series. Closed magnetic surface, islands, chaotic field line region and divertor field lines are well reproduced by this simple model. (author)
Chiral symmetry and strangeness at SIS energies
International Nuclear Information System (INIS)
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.)
Heterotic and type II orientifold compactifications on SU(3) structure manifolds
International Nuclear Information System (INIS)
We study the four-dimensional N=1 effective theories of generic SU(3) structure compactifications in the presence of background fluxes. For heterotic and type IIA/B orientifold theories, the N=1 characteristic data are determined by a Kaluza-Klein reduction of the fermionic actions. The Kaehler potentials, superpotentials and the D-terms are entirely encoded by geometrical data of the internal manifold. The background flux and the intrinsic torsion of the SU(3) structure manifold, gives rise to contributions to the four-dimensional F-terms. The corresponding superpotentials generalize the Gukov-Vafa-Witten superpotential. For the heterotic compactification, the four-dimensional fermionic supersymmetry variations, as well as the conditions on supersymmetric vacua, are determined. The Yukawa couplings of the theory turn out to be similar to their Calabi-Yau counterparts. (Orig.)
Heterotic and type II orientifold compactifications on SU(3) structure manifolds
Energy Technology Data Exchange (ETDEWEB)
Benmachiche, I.
2006-07-15
We study the four-dimensional N=1 effective theories of generic SU(3) structure compactifications in the presence of background fluxes. For heterotic and type IIA/B orientifold theories, the N=1 characteristic data are determined by a Kaluza-Klein reduction of the fermionic actions. The Kaehler potentials, superpotentials and the D-terms are entirely encoded by geometrical data of the internal manifold. The background flux and the intrinsic torsion of the SU(3) structure manifold, gives rise to contributions to the four-dimensional F-terms. The corresponding superpotentials generalize the Gukov-Vafa-Witten superpotential. For the heterotic compactification, the four-dimensional fermionic supersymmetry variations, as well as the conditions on supersymmetric vacua, are determined. The Yukawa couplings of the theory turn out to be similar to their Calabi-Yau counterparts. (Orig.)
Magnetic monopole and confinement/deconfinement phase transition in SU(3) Yang-Mills theory
Shibata, Akihiro; Kato, Seikou; Shinohara, Toru
2015-01-01
We have proposed the non-Abelian dual superconductivity in SU(3) Yang-Mills theory for the mechanism of quark confinement,and we presented the numerical evidences in preceding lattice conferences by using the proposed gauge link decomposition to extract magnetic monopole in the gauge invariant way. In this talk, we focus on the dual Meissner effects in view of the magnetic monopole in SU(3) Yang-Mills theory. We measure the chromoelectric and chromomagnetic flux due to a pair of quark and antiquark source at finite temperature. Then, we measure the correlation function of Polyakov loops and Polyakov loop average at various temperatures, and investigate chromomagnetic monopole current induced by chromo-magnetic flux in both confinement and deconfinement phase. We will discuss the role of the chromoelectric monopole in confinement/deconfinement phase transition.
Broken SU(3) antidecuplet for Θ+ and Ξ3/2
International Nuclear Information System (INIS)
If the narrow exotic baryon resonances Θ+(1540) and Ξ3/2 are members of the JP = 1/2+ antidecuplet with N*(1710), the octet-antidecuplet mixing is required not only by the mass spectrum but also by the decay pattern of N*(1710). This casts doubt on validity of the Θ+ mass prediction by the chiral soliton model. While all pieces of the existing experimental information point to a small octet-decuplet mixing, the magnitude of mixing required by the mass spectrum is not consistent with the value needed to account for the hadronic decay rates. The discrepancy is not resolved even after the large experimental uncertainty is taken into consideration. We fail to find an alternative SU(3) assignment even with different spin-parity assignment. When we extend the analysis to mixing with a higher SU(3) multiplet, we find one experimentally testable scenario in the case of mixing with a 27-plet
Thermodynamics and reference scale of SU(3) gauge theory from gradient flow on fine lattices
Kitazawa, Masakiyo; Hatsuda, Tetsuo; Iritani, Takumi; Itou, Etsuko; Suzuki, Hiroshi
2015-01-01
We study the parametrization of lattice spacing and thermodynamics of SU(3) gauge theory on the basis of the Yang-Mills gradient flow on fine lattices. The lattice spacing of the Wilson gauge action is determined over a wide range $6.3\\le\\beta\\le7.5$ with high accuracy. The measurements of the flow time and lattice spacing dependences of the expectation values of the energy-momentum tensor are performed on fine lattices.
The quantization of exotic states in SU(3) soliton models: A solvable quantum mechanical analog
Cherman, Aleksey; Cohen, Thomas D.; Nellore, Abhinav
2004-01-01
The distinction between the rigid rotor and Callan-Klebanov approaches to the quantization of SU(3) solitons is considered in the context of exotic baryons. A numerically tractable quantum mechanical analog system is introduced to test the reliability of the two quantization schemes. We find that in the equivalent of the large N_c limit of QCD, the Callan-Klebanov approach agrees with a numerical solution of the quantum mechanical analog. Rigid rotor quantization generally does not. The impli...
Low-Temperature Thermodynamics of $A^{(2)}_2$ and su(3)-invariant Spin Chains
Mezincescu, L; Townsend, P K; Tsvelik, A M; Mezincescu, Luca; Nepomechie, Rafael I.
1993-01-01
We formulate the thermodynamic Bethe Ansatz (TBA) equations for the closed (periodic boundary conditions) $A^{(2)}_2$ quantum spin chain in an external magnetic field, in the (noncritical) regime where the anisotropy parameter $\\eta$ is real. In the limit $\\eta \\to 0$, we recover the TBA equations of the antiferromagnetic su(3)-invariant chain in the fundamental representation. We solve these equations for low temperature and small field, and calculate the specific heat and magnetic susceptibility.
Renormalization group improved action for SU(3) lattice gauge theory and the string tension
International Nuclear Information System (INIS)
The expectation values of the Wilson loops and the string tension are calculated by Monte Carlo simulations for SU(3) lattice gauge theory with a renormalization group improved action, the form of which is chosen from a block spin renormalization group study and an analysis of instantions on the lattice. The string tension is about 2.5 times larger than that obtained so far for the standard model. The deconfinement phase transition temperature is also calculated roughly. (orig.)
Polyakov loop fluctuations in SU(3) lattice gauge theory and an effective gluon potential
Lo, Pok Man; Friman, Bengt; Kaczmarek, Olaf; Redlich, Krzysztof; Sasaki, Chihiro
2013-01-01
We calculate the Polyakov loop susceptibilities in the SU(3) lattice gauge theory using the Symanzik improved gauge action on different-sized lattices. The longitudinal and transverse fluctu- ations of the Polyakov loop, as well as, that of its absolute value are considered. We analyze their properties in relation to the confinement-deconfinement phase transition. We also present results based on simulations of (2+1)-flavor QCD on 32^3 x 8 lattice using Highly Improved Staggered Quark (HISQ) ...
Polyakov loop in different representations of SU(3) at finite temperature
S Gupta; Huebner, K; Kaczmarek, O.
2006-01-01
We investigate the Polyakov loop in different representations of SU(3) in pure gauge at finite $T$. We discuss Casimir scaling for the Polyakov loop in the deconfined phase and test and generalize the renormalization procedure for the Polyakov loop from \\cite{Kaczmarek:2002mc} to arbitrary representations. In the confined phase we extract the renormalized adjoint Polyakov loop, which is finite in the thermodynamic limit. For our numerical calculations we used the tree-level improved Symanzik ...
Magnetic susceptibility of the QCD vacuum in a nonlocal SU(3) PNJL model
Pagura, V P; Noguera, S; Scoccola, N N
2016-01-01
The magnetic susceptibility of the QCD vacuum is analyzed in the framework of a nonlocal SU(3) Polyakov-Nambu-Jona-Lasinio model. Considering two different model parametrizations, we estimate the values of the $u$ and $s$-quark tensor coefficients and magnetic susceptibilities and then we extend the analysis to finite temperature systems. Our numerical results are compared to those obtained in other theoretical approaches and in lattice QCD calculations.
Strange quark matter in a chiral SU(3) quark mean field model
Wang, P.; Lyubovitskij, V. E.; Gutsche, Th.; Faessler, Amand
2002-01-01
We apply the chiral SU(3) quark mean field model to investigate strange quark matter. The stability of strange quark matter with different strangeness fraction is studied. The interaction between quarks and vector mesons destabilizes the strange quark matter. If the strength of the vector coupling is the same as in hadronic matter, strangelets can not be formed. For the case of beta equilibrium, there is no strange quark matter which can be stable against hadron emission even without vector m...
Spectrum of positive and negative parity pentaquarks, including $SU(3)_F$ breaking
Abud, M; Falcone, D; Ricciardi, G; Tramontano, F
2008-01-01
We present the spectrum of the lightest pentaquark states of both parities and compare it with the present experimental evidence for these states. We have assumed that the main role for their mass splittings is played by the chromo-magnetic interaction. We have also kept into account the $SU(3)_F$ breaking for their contribution and for the spin orbit term. The resulting pattern is in good agreement with experiment.
Spatial Correlation of the Topological Charge in Pure SU(3) Gauge Theory and in QCD
Hasenfratz, Anna
1999-01-01
We study the spatial correlator of the topological charge density operator in pure SU(3) gauge theory and in two flavor QCD. We show that the data for distances up to about 1 fm is consistent with a vacuum consisting of individual instantons and closely bound pairs. The percentage of paired objects is twice as large on the dynamical configurations than on the pure gauge ones, implying increased molecule formations due to fermionic interactions.
Flux tubes in the SU(3) vacuum: London penetration depth and coherence length
Cea, Paolo; Cosmai, Leonardo; Cuteri, Francesca; Papa, Alessandro
2014-01-01
Within the dual superconductor scenario for the QCD confining vacuum, the chromoelectric field generated by a static $q\\overline{q}$ pair can be fitted by a function derived, by dual analogy, from a simple variational model for the magnitude of the normalized order parameter of an isolated Abrikosov vortex. Previous results for the SU(3) vacuum are revisited, but here the transverse chromoelectric field is measured by means of the connected correlator of two Polyakov loops and, in order to re...
Quasi-integrable deformations of the $SU(3)$ Affine Toda Theory
Ferreira, Luiz A.; Klimas, Pawel; Zakrzewski, Wojtek J.
2016-01-01
We consider deformations of the $SU(3)$ Affine Toda theory (AT) and investigate the integrability properties of the deformed theories. We find that for some special deformations all conserved quantities change to being conserved only asymptotically, {\\it i.e.} in the process of the scattering of two solitons these charges do vary in time, but they return, after the scattering, to the values they had prior to the scattering. This phenomenon, which we have called quasi-integrability, is related...
The Economical SU(3CÃ¢ÂŠÂ—SU(3LÃ¢ÂŠÂ—U(1X Model
Directory of Open Access Journals (Sweden)
P. V. Dong
2008-08-01
Full Text Available The SU(3CÃ¢ÂŠÂ—SU(3LÃ¢ÂŠÂ—U(1X gauge model with minimal scalar sector, two Higgs triplets, is presented in detail. One of the vacuum expectation values u is a source of lepton-number violations and a reason for mixing among charged gauge bosonsÃ¢Â€Â”the standard model WÃ‚Â± and the bilepton gauge bosons YÃ‚Â±, as well as among the neutral non-Hermitian bilepton X0 and neutral gauge bosonsÃ¢Â€Â”the Z and the new ZÃ¢Â€Â². An exact diagonalization of the neutral gauge boson sector is derived, and bilepton mass splitting is also given. Because of these mixings, the lepton-number violating interactions exist in both charged and neutral gauge boson sectors. Constraints on vacuum expectation values of the model are estimated and uÃ¢Â‰ÂƒÃ°ÂÂ’Âª(1 GeV, vÃ¢Â‰Âƒvweak=246 GeV, and ÃÂ‰Ã¢Â‰ÂƒÃ°ÂÂ’Âª(1 TeV. In this model, there are three physical scalars, two neutral and one charged, and eight Goldstone bosonsÃ¢Â€Â”the needed number for massive gauge bosons. The minimal scalar sector can provide all fermions including quarks and neutrinos consistent masses in which some of them require one-loop radiative corrections.
Infrared Zero of $\\beta$ and Value of $\\gamma_m$ for an SU(3) Gauge Theory at the Five-Loop Level
Ryttov, Thomas A
2016-01-01
We calculate the value of the coupling at the infrared zero of the beta function of an asymptotically free SU(3) gauge theory at the five-loop level as a function of the number of fermions. Both a direct analysis of the beta function and analyses of Pad\\'e approximants are used for this purpose. We then calculate the value of the five-loop anomalous dimension, $\\gamma_m$, of the fermion bilinear at this IR zero of the beta function.
Adler, Stephen L.
2016-08-01
We study SU(8) symmetry breaking induced by minimizing the Coleman–Weinberg effective potential for a third rank antisymmetric tensor scalar field in the 56 representation. Instead of breaking {SU}(8)\\supset {SU}(3)× {SU}(5), we find that the stable minimum of the potential breaks the original symmetry according to {SU}(8)\\supset {SU}(3)× {Sp}(4). Using both numerical and analytical methods, we present results for the potential minimum, the corresponding Goldstone boson structure and BEH mechanism, and the group-theoretic classification of the residual states after symmetry breaking.
Adler, Stephen L
2016-01-01
We study $SU(8)$ symmetry breaking induced by minimizing the Coleman-Weinberg effective potential for a third rank antisymmetric tensor scalar field in the 56 representation. Instead of breaking $SU(8) \\supset SU(3) \\times SU(5)$, we find that the stable minimum of the potential breaks the original symmetry according to $SU(8) \\supset SU(3) \\times Sp(4)$. Using both numerical and analytical methods, we present results for the potential minimum, the corresponding Goldstone boson structure and BEH mechanism, and the group-theoretic classification of the residual states after symmetry breaking.
Dynamical Symmetry Breaking in a Minimal 3-3-1 Model
Doff, A.(Universidade Tecnológica Federal do Paraná – UTFPR – DAFIS, Av. Monteiro Lobato Km 04, 84016-210 Ponta Grossa, PR, Brazil); Natale, A. A.
2012-01-01
The gauge symmetry breaking in some versions of 3-3-1 models can be implemented dynamically because at the scale of a few TeVs the $U(1)_X$ coupling constant becomes strong. In this work we consider the dynamical symmetry breaking in a minimal $SU(3)_{{}_{TC}}\\times SU(3)_{{}_{L}}\\times U(1)_{X}$ model, where we propose a new scheme to cancel the chiral anomalies, including two-index symmetric (6) technifermions, which incorporates naturally the walking behavior in the TC sector. The composit...
Electroweak Symmetry Breaking by QCD
Kubo, Jisuke; Lindner, Manfred
2014-01-01
We propose a new mechanism to generate the electroweak scale within the framework of QCD, which is extended to include conformally invariant scalar degrees of freedom belonging to a larger irreducible representation of $SU(3)_c$. The electroweak symmetry breaking is triggered dynamically via the Higgs portal by the condensation of the colored scalar field around $1$ TeV. The mass of the colored boson is restricted to be $350$ GeV $\\lesssim m_S\\lesssim 3$ TeV, with the upper bound obtained from renormalization group evolution. This implies that the colored boson can be produced at LHC. If the colored boson is electrically charged, the branching fraction of the Higgs decaying into two photons can slightly increase, and moreover, it can be produced at future linear colliders.
International Nuclear Information System (INIS)
We propose a novel SU(3)c×SU(2)L×SU(2)R×U(1)B-L left-right symmetric model where the standard model fermion and Higgs fields are SU(2)L doublets or SU(2) singlets while their mirror partners are SU(2)R doublets or SU(2) singlets. The scalar fields also include a real singlet for dark matter and two SU(2) triplets for seesaw. The mixing between the standard model and mirror fermions is forbidden by a Z2×Z2′ discrete symmetry. The mirror charged fermions can decay into their standard model partners with the dark-matter scalar while the mirror neutrinos can decay into the mirror charged fermions through the right-handed gauge interactions. Our model can have new implications on the strong CP problem, leptogenesis, collider phenomenology and dark matter detection.
Analytic Approximations for the Extrapolation of Lattice Data
Masjuan, Pere
2010-01-01
We present analytic approximations of chiral SU(3) amplitudes for the extrapolation of lattice data to the physical masses and the determination of Next-to-Next-to-Leading-Order low-energy constants. Lattice data for the ratio F_K/F_pi is used to test the approximation proposed.
Unified models and unitary symmetry
International Nuclear Information System (INIS)
The experimentally established small size of the space time region where weak interactions occur; ''the weak beg'', is taken as a starting point for a dynamical model for parity violation in weak interactions. It is argued that weakly interacting Dirac bi-spinors behave as massles in the weak beg, and then they split into pairs of decoupled Weyl spinors. As a consequence, any P, C, T conserving gauge Lagrangian in terms of multiplets of Dirac fields will split, in the weak bag, into P and C violating terms representing the weak interactions of the concerned fermions. Following the criterion of maximal simplicity and economy, some SU(N), U(N) symmetruc models are presented. It is shown that (a) Reduction of SU(3) x P, C, T symmetry to SU(2) x U(1) x PC, T for weak interactions is easily obtained by force of chiral projectors. (b) The models are apt to represent all weak and e.m. properties of known leptons and a unified model for weak and e.m. interactions, generalization of the Salam-Weinberg model, emerges with the mixing angle theta depending on N in SU(N). For N=3 the model coincides with the Salam-Weinberg model with theta=30sup(deg). At present experimental data seem to favour the SU(4) model where sin sup(2)theta = 1/3. (c) Absence of ΔS=1 neutral currents can easily be explained already in the frame of SU(3). (d) Integer charges for leptons and fractional charges for quarks can be fitted in appropriate SU(3)-U(3) models. (e) In U(N) symmetric models the resulting q.e.d. presents Pauli-Villars regularization of the self-energy and vertex parts, and the Schwinger-Dyson equations for self-masses are of the Fredholm type as a consequence of the U(N) symmetry and of the neutral currents. The possibility then arises of a full q.e.d. regularization by weak interactions. (f) Neutral current interactions are parity conserving (axial) among charged particles, while parity violating among neutral-charged, neutral-neutral ones in all models presented. A generalized
Attanucci, Frank J.; Losse, John
2008-01-01
In a first calculus course, it is not unusual for students to encounter the theorems which state: If f is an even (odd) differentiable function, then its derivative is odd (even). In our paper, we prove some theorems which show how the symmetry of a continuous function f with respect to (i) the vertical line: x = a or (ii) with respect to the…
International Nuclear Information System (INIS)
We present many varied chiral symmetry models at the quark level which consistently describe strong interaction hadron dynamics. The pattern that emerges is a nonstrange current quark mass scale mcur ≅ (34-69) MeV and a current quark mass ratio (ms/m)cur ≅ 5-6 along with no strange quark content in nucleons. (orig./WL)
Ledwig, Tim; Goeke, Klaus
2008-01-01
We investigate the vector transition form factors of the nucleon and vector meson $K^*$ to the pentaquark baryon $\\Theta^+$ within the framework of the SU(3) chiral quark-soliton model. We take into account the rotational $1/N_c$ and linear $m_{\\rm s}$ corrections, assuming isospin symmetry and employing the symmetry-conserving quantization. It turns out that the leading-order contributions to the form factors are almost cancelled by the rotational corrections. Because of this, the flavor SU(3) symmetry-breaking terms yield sizeable effects on the transition form factors. In particular, the main contribution to the electric transition form factor comes from the wave-function corrections, which is a consequence of the generalized Ademollo-Gatto theorem derived in the present work. We estimate with the help of the vector meson dominance the $K^*$ vector and tensor coupling constants for the $\\Theta^+$: $g_{K^{*}N\\Theta}=0.74 - 0.87$ and $f_{K^{*}N\\Theta}=0.53 - 1.16$. We argue that the outcome of the present wo...
Spectral functions in finite temperature SU(3) gauge theory and applications to transport phenomena
International Nuclear Information System (INIS)
In this thesis, gluon spectral functions in SU(3) gauge theory are calculated at finite temperature. The temperature range covers the confining regime below Tc to the high temperature regime, where perturbation theory is applicable. The numerical tool is the Maximum Entropy Method (MEM) employing euclidean, non-perturbative, Landau gauge gluon propagators, obtained with the Functional Renormalisation Group and Lattice QCD, as input. The spectral function is related to the propagators by an integral equation. MEM is a complex multidimensional optimisation algorithm to invert such integral equations, corresponding to an analytic continuation of the numerical data. A continuation of a discreet set of data cannot be unambiguous. The occuring ambiguities are resolved by introducing a priori knowledge of the asymptotic shape of the spectral function, in the form of a model function. Thereby, MEM simultaneously optimizes the spectral function to the input propagators and the model, leading to a unique model-dependent solution. Standard-MEM assumes positive definite spectral functions, whereas gluons show a violation of positivity in the spectral function, due to confinement. Therefore, an extended-MEM algorithm is proposed. The main application of this thesis is the calculation of the shear viscosity in units of the entropy density. A Kubo relation connects shear viscosity to the low frequency limit of a certain energy-momentum tensor correlation function. For this correlation function a loop representation of finite order in terms of gluon spectral functions is derived. That allows to calculate (η)/(s) from first principles in SU(3) for the first time for arbitrary temperatures. Further, a mapping of the SU(3) results for (η)/(s) to QCD is proposed.
SU(3) Polyakov linear-sigma model: bulk and shear viscosity of QCD matter in finite magnetic field
Tawfik, Abdel Nasser; Hussein, T M
2016-01-01
Due to off-center relativistic motion of the charged spectators and the local momentum-imbalance of the participants, a short-lived huge magnetic field is likely generated, especially in relativistic heavy-ion collisions. In determining the temperature dependence of bulk and shear viscosities of the QCD matter in vanishing and finite magnetic field, we utilize mean field approximation to the SU($3$) Polyakov linear-sigma model (PLSM). We compare between the results from two different approaches; Green-Kubo correlation and Boltzmann master equation with Chapman-Enskog expansion. We find that both approaches have almost identical results, especially in the hadron phase. In the temperature dependence of bulk and shear viscosities relative to thermal entropy at the critical temperature, there is a rapid decrease in the chiral phase-transition and in the critical temperature with increasing magnetic field. As the magnetic field strength increases, a peak appears at the critical temperature ($T_c$). This can be und...
Fisher zeros and RG flows for $SU(3)$ with $N_f$ flavors
Gelzer, Zechariah; Meurice, Yannick; Sinclair, Donald
2013-01-01
We calculate the Fisher zeros for $SU(3)$ gauge theory with different $N_f$ flavors of staggered fermions for various values of the fermion mass. We discuss the finite-size scaling near the end point of the line of discontinuity of $\\bar{\\psi} \\psi$ in the beta-mass plane and in the larger beta-lower mass region. We discuss possible interpretations of these results in terms of Wilsonian RG flows and their possible relevance to construct composite Higgs models.
The quantization of exotic states in SU(3) soliton models: A solvable quantum mechanical analog
Cherman, A; Nellore, A; Cherman, Aleksey; Cohen, Thomas D.; Nellore, Abhinav
2004-01-01
The distinction between the rigid rotor and Callan-Klebanov approaches to the quantization of SU(3) solitons is considered in the context of exotic baryons. A numerically tractable quantum mechanical analog system is introduced to test the reliability of the two quantization schemes. We find that in the equivalent of the large N_c limit of QCD, the Callan-Klebanov approach agrees with a numerical solution of the quantum mechanical analog. Rigid rotor quantization generally does not. The implications for exotic baryons are briefly discussed.
Relative weights approach to SU(3) gauge theories with dynamical fermions at finite density
Höllwieser, Roman
2016-01-01
We derive effective Polyakov line actions for SU(3) gauge theories with staggered dynamical fermions, for a small sample of lattice couplings, lattice actions, and lattice extensions in the time direction. The derivation is via the method of relative weights, and the theories are solved at finite chemical potential by mean field theory. We find in some instances that the long-range couplings in the effective action are very important to the phase structure, and that these couplings are responsible for long-lived metastable states in the effective theory. Only one of these states corresponds to the underlying lattice gauge theory.
Non-Abelian {SU}{(3)}_{k} anyons: inversion identities for higher rank face models
Frahm, Holger; Karaiskos, Nikos
2015-12-01
The spectral problem for an integrable system of particles satisfying the fusion rules of {SU}{(3)}k is expressed in terms of exact inversion identities satisfied by the commuting transfer matrices of the integrable fused {A}2(1) interaction round a face model of Jimbo, Miwa and Okado. The identities are proven using local properties of the Boltzmann weights, in particular the Yang-Baxter equation and unitarity. They are closely related to the consistency conditions for the construction of eigenvalues obtained in the separation of variables approach to integrable vertex models.
Two-point functions for SU(3) Polyakov Loops near T_c
Dumitru, Adrian; Pisarski, Robert D.
2002-01-01
We discuss the behavior of two point functions for Polyakov loops in a SU(3) gauge theory about the critical temperature, T_c. From a Z(3) model, in mean field theory we obtain a prediction for the ratio of masses at T_c, extracted from correlation functions for the imaginary and real parts of the Polyakov loop. This ratio is m_i/m_r = 3 if the potential only includes terms up to quartic order in the Polyakov loop; its value changes as pentic and hexatic interactions become important. The Pol...
Three particle Poincare states and SU(6) x SU(3) as a classification group for baryons
International Nuclear Information System (INIS)
A complete set of democratic quantum numbers is introduced to classify the states of an irreducible unitary representation (IUR) of the Poincare group obtained from the decomposition of the direct products of three I.U.R. Such states are identified with the baryon states constituted of three free relativistic quarks. The transformation from current to constituent quarks is then easily reobtained. Moreover, the group SU(6) x SU(3) appears naturally as a collinear classification group for baryons. Results similar to those of the symmetric harmonic oscillator quark model are obtained
SU(3)--Breaking Effects in Axial--Vector Couplings of Octet Baryons
Gensini, P M; Gensini, Paolo M.; Violini, Galileo
1993-01-01
Present evidence on baryon axial--vector couplings is reviewed, the main emphasis being on internal consistency between asymmetry and rate data. A complete account of all {\\sl small} terms in the Standard Model description of these latter leads to {\\sl both} consistency {\\sl and} evidence for breaking of flavour SU(3) in the axial couplings of octet baryons. Talk presented at "5th Int. Sympos. on Meson--Nucleon Physics and the Structure of the Nucleon", Boulder, CO, sept. 1993. To be published in $\\pi N$ Newsletter.
Consistency between SU(3) and SU(2) chiral perturbation theory for the nucleon mass
Ren, Xiu-Lei; Alvarez-Ruso, L.; Geng, Li-Sheng; Ledwig, T.; Meng, Jie; Vacas, M. J. Vicente
2016-01-01
Treating the strange quark mass as a heavy scale compared to the light quark mass, we perform a matching of the nucleon mass in the SU(3) sector to the two-flavor case in covariant baryon chiral perturbation theory. The validity of the $19$ low-energy constants appearing in the octet baryon masses up to next-to-next-to-next-to-leading order~\\cite{Ren:2014vea} is supported by comparing the effective parameters (the combinations of the $19$ couplings) with the corresponding low-energy constants...
The classically perfect fixed point action for SU(3) gauge theory
DeGrand, T; Hasenfratz, A.; Hasenfratz, P.; Niedermayer, F.
1995-01-01
In this paper (the first of a series) we describe the construction of fixed point actions for lattice $SU(3)$ pure gauge theory. Fixed point actions have scale invariant instanton solutions and the spectrum of their quadratic part is exact (they are classical perfect actions). We argue that the fixed point action is even 1--loop quantum perfect, i.e. in its physical predictions there are no $g^2 a^n$ cut--off effects for any $n$. We discuss the construction of fixed point operators and presen...
Unified SU(3) x U(1) gauge theory with different muon and electron neutral currents
International Nuclear Information System (INIS)
We propose a gauge theory of weak and electromagnetic interactions based on SU(3) x U(1). The muonic and electronic doublets are classified differently. As a consequence, we get the same predictions of the Weinberg-Salam SU(2) x U(1) theory for the ν/sub μ/ - (nu-bar/sub μ/-) initiated processes and parity conservation in atoms. The muon number is exactly conserved. Predictions are made that will be tested in the future high-energy colliding-beam experiments
Unified SU(3) x U(1) gauge theory with different muon and electron neutral currents
Energy Technology Data Exchange (ETDEWEB)
Buccella, F.; Lusignoli, M.; Pugliese, A.
1978-06-05
We propose a gauge theory of weak and electromagnetic interactions based on SU(3) x U(1). The muonic and electronic doublets are classified differently. As a consequence, we get the same predictions of the Weinberg-Salam SU(2) x U(1) theory for the ..nu../sub ..mu../ - (nu-bar/sub ..mu../-) initiated processes and parity conservation in atoms. The muon number is exactly conserved. Predictions are made that will be tested in the future high-energy colliding-beam experiments.
Efficient multitasking of the SU(3) lattice gauge theory algorithm on the CRAY X-MP
International Nuclear Information System (INIS)
The Monte Carlo lattice gauge theory algorithm with the Metropolis et.al. updating procedure is vectorized and multitasked on the four processor CRAY X-MP and results in a code with a link-update-time, in 64-bit arithmetic and 10 hits-per-link, of 11.0 μs on a 164 lattice, the fastest link-update-time so far achieved. The program calculates the Wilson loops of size up to L/2.L/2 for an L4 lattice for SU(3) gauge theory. (orig./HSI)
A massive quasi-particle model of the SU(3) gluon plasma
International Nuclear Information System (INIS)
Recent SU(3) gauge field lattice data for the equation of state are interpreted by a quasi-particle model with effective thermal gluon masses. The model is motivated by lowest-order perturbative QCD and describes very well the data. The proposed quasi-particle approach can be applied to study color excitations in the non-perturbative regime. As an example we estimate the temperature dependence of the Debye screening mass and find that it declines sharply when approaching the confinement temperature from above, while the thermal mass continuously rises. (orig.)
Discriminating between two reformulations of SU(3) Yang-Mills theory on a lattice
Energy Technology Data Exchange (ETDEWEB)
Shibata, Akihiro [Computing Research Center, High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan); Kondo, Kei-Ichi; Shinohara, Toru [Department of Physics, Graduate School of Science, Chiba University, Chiba 263-8522 (Japan); Kato, Seikou [Fukui National College of Technology, Sabae 916-8507 (Japan)
2016-01-22
In order to investigate quark confinement, we give a new reformulation of the SU (N) Yang-Mills theory on a lattice and present the results of the numerical simulations of the SU (3) Yang-Mills theory on a lattice. The numerical simulations include the derivation of the linear potential for static interquark potential, i.e., non-vanishing string tension, in which the “Abelian” dominance and magnetic monopole dominance are established, confirmation of the dual Meissner effect by measuring the chromoelectric flux tube between quark-antiquark pair, the induced magnetic-monopole current, and the type of dual superconductivity, etc.
A precise determination of the running coupling in the SU(3) Yang-Mills theory
International Nuclear Information System (INIS)
A non-perturbative finite-size scaling technique is used to study the evolution of the running coupling (in a certain adapted scheme) in the SU(3) Yang-Mills theory. At low energies contact is made with the fundamental dynamical scales, such as the string tension K, while at larger energies the coupling is shown to evolve according to perturbation theory. In that regime the coupling in the anti M anti S scheme of dimensional regularization is obtained with an estimated total error of a few percent. (orig.)
NΩ and ΔΩ dibaryons in a SU(3) chiral quark model
International Nuclear Information System (INIS)
The binding energy of the six-quark system with strangeness s=-3 is investigated under the chiral SU(3) constituent quark model in the framework of RGM. The calculations of the single NΩ channel with spin S=2 and the single ΔΩ channel with spin S=3 are performed. The results show that both systems could be dibaryons and the interaction induced by the chiral field plays a very important role on forming bound states in the systems considered. The phase shifts and scattering lengths in corresponding channels are also given. (orig.)
ΞΩ and Ξ*Ω dibaryons in SU(3) chiral quark model
International Nuclear Information System (INIS)
The binding energy of the six quark system with strangeness s = -5 is investigated by the SU(3) chiral constituent quark model. the single Ξ*Ω channel calculation with spin S = 0 and the coupled ΞΩ-Ξ*Ω channel calculation with spin S = 1 are considered. It is shown that in the spin S = 0 case, the binding energy of Ξ*Ω is ranged from 80.0 to 92.4 MeV, while in the S = 1 case, the additional Ξ*Ω channel increases the binding energy of ΞΩ to a range of 26.2-32.9 MeV
Flux tubes in the SU(3) vacuum: London penetration depth and coherence length
Cea, Paolo; Cosmai, Leonardo; Cuteri, Francesca; Papa, Alessandro
2014-05-01
Within the dual superconductor scenario for the QCD confining vacuum, the chromoelectric field generated by a static qq¯ pair can be fitted by a function derived, by dual analogy, from a simple variational model for the magnitude of the normalized order parameter of an isolated Abrikosov vortex. Previous results for the SU(3) vacuum are revisited, but here the transverse chromoelectric field is measured by means of the connected correlator of two Polyakov loops and, in order to reduce noise, the smearing procedure is used instead of cooling. The penetration and coherence lengths of the flux tube are then extracted from the fit and compared with previous results.
Flux tubes in the SU(3) vacuum: London penetration depth and coherence length
Cea, Paolo; Cuteri, Francesca; Papa, Alessandro
2014-01-01
Within the dual superconductor scenario for the QCD confining vacuum, the chromoelectric field generated by a static $q\\overline{q}$ pair can be fitted by a function derived, by dual analogy, from a simple variational model for the magnitude of the normalized order parameter of an isolated Abrikosov vortex. Previous results for the SU(3) vacuum are revisited, but here the transverse chromoelectric field is measured by means of the connected correlator of two Polyakov loops and, in order to reduce noise, the smearing procedure is used instead of cooling. The penetration and coherence lengths of the flux tube are then extracted from the fit and compared with previous results.
Hyperons in nuclear matter from SU(3) chiral effective field theory
Energy Technology Data Exchange (ETDEWEB)
Petschauer, S.; Kaiser, N. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Haidenbauer, J. [Institut fuer Kernphysik, Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich Center for Hadron Physics, Juelich (Germany); Meissner, Ulf G. [Institut fuer Kernphysik, Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich Center for Hadron Physics, Juelich (Germany); Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Weise, W. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Villa Tambosi, ECT, Villazzano (Trento) (Italy)
2016-01-15
Brueckner theory is used to investigate the properties of hyperons in nuclear matter. The hyperon-nucleon interaction is taken from chiral effective field theory at next-to-leading order with SU(3) symmetric low-energy constants. Furthermore, the underlying nucleon-nucleon interaction is also derived within chiral effective field theory. We present the single-particle potentials of Λ and Σ hyperons in symmetric and asymmetric nuclear matter computed with the continuous choice for intermediate spectra. The results are in good agreement with the empirical information. In particular, our calculation gives a repulsive Σ-nuclear potential and a weak Λ-nuclear spin-orbit force. (orig.)
Equation of state for pure SU(3) gauge theory on anisotropic lattices
International Nuclear Information System (INIS)
We present results for the equation of state for pure SU(3) gauge theory obtained on anisotropic lattices with the anisotropy ξ ≡ as/at = 2. The pressure and energy density are calculated on Nt/ξ = 4, 5 and 6 lattices with the integral method. They are found to satisfy the leading 1/Nt2 scaling from our coarsest lattice Nt/ξ = 4. This enables us to carry out well controlled continuum extrapolations. We find that the pressure and energy density agree with those obtained using the isotropic plaquette action, but have smaller and more reliable errors
Progress toward the effective Quantum Chromodynamic Lagrangian from symmetry considerations
Energy Technology Data Exchange (ETDEWEB)
Salomone, A.N.
1982-01-01
The properties of an effective Lagrangian which satisfies both the axial and trace anomaly equations of Quantum Chromodynamics are investigated both from the theoretical and phenomenological points of view. The model Lagrangian requires that chiral symmetry be broken spontaneously. The non-linear approximation of the model illuminates eta-glue duality or mixing. The phase transition behavior of the model of Quantum Chromodynamics can be studied as the numbers of flavors and the vacuum angle are varied by analyzing a simple mechanical analog. The analog of the model is similar to the massive Schwinger model. The possibility of a physical scalar glue state is discussed and it is shown that it is characterized by a pronounced eta to two glue decay width. A nonperturbative Quantum Chromodynamic vacuum is seen to follow directly from satisfying the trace anomaly. The quark matter meson, eta, is at least as prominent as the glueball, iota, in the gluon dominated reaction psi to gamma plus anything. An associated large breaking of flavor SU(3) is shown to be ameliorated as the model is made more realistic by lowering scalar meson masses from infinity. The pi delta decay of the iota (1440) can be reasonably well estimated without the need of introducing any new parameters.
Symmetry relation for helical plasma. Parity symmetry
International Nuclear Information System (INIS)
It is shown that a strict symmetry relation holds in the LHD (Large Helical Device) type helical magnetic field. The symmetry relation is expressed explicitly in the rotating helical coordinate system and named as parity symmetry in helical system. A new concept, -concept of even scalars, odd scalars, even vectors, odd vectors-, is introduced. Calculus of vector operation retains strictly the parity relations for these quantities. For example, the vector product of two vectors with same parity become an odd parity vector. The rotation of a vector field A, ∇xA, has same parity characteristics with that of the vector A. It is concluded that the equilibrium magnetic field and current distribution are expressed by even parity vectors. Pressure distribution is expressed by an even parity scalar function. The parity symmetry relations conduct uniquely the power expansion form of equilibrium magnetic field and pressure distribution. Analytical expressions for these quantities are obtained approximately by truncation of the power series. An example of vacuum helical magnetic field is shown in the following, B=∇xA+B0(0, 0, r0/r), A=Bp/a=-(p/3r)Y3-(p3/12r3)Y(X4+Y4), -(p/3r)X3-(p3/12r3)X(X4+Y4), -((X2-Y2)/2)(1-(Xcos(pφ)-Ysin(pφ))/4r)-(p4/6r4)X2Y2)=, where p, r0, a, Bp, B0 are constants for magnetic field. Rotating helical coordinate system is expressed by (X, Y, φ) and r≡r0+Xcos (pφ) - Ysin (pφ). Closed magnetic surface, islands, chaotic field line region and divertor field lines are well represented by this simple model. (author)
A tree-level 3-point function in the su(3)-sector of planar N=4 SYM
Foda, Omar; Kostov, Ivan; Serban, Didina
2013-01-01
We classify the 3-point functions of local gauge-invariant single-trace operators in the scalar sector of planar N=4 supersymmetric Yang-Mills involving at least one su(3) operator. In the case of two su(3) and one su(2) operators, the tree-level 3-point function can be expressed in terms of scalar products of su(3) Bethe vectors. Moreover, if the second level Bethe roots of one of the su(3) operators is trivial (set to infinity), this 3-point function can be written in a determinant form. Using the determinant representation, we evaluate the structure constant in the semi-classical limit, when the number of roots goes to infinity.
SU(3)F breaking in D → P1P8 and D → P1P1
International Nuclear Information System (INIS)
We perform a SU(3) flavor analysis of nonleptonic charm decays to a pseudoscalar octet and singlet and to two pseudoscalar singlets. The analysis includes linear breaking effects caused by different quark masses ms ≠ mu,d.
LIE SYMMETRIES AND NOETHER SYMMETRIES
Directory of Open Access Journals (Sweden)
PGL Leach
2012-10-01
Full Text Available We demonstrate that so-called nonnoetherian symmetries with which a known first integral is associated of a differential equation derived from a Lagrangian are in fact noetherian. The source of the misunderstanding lies in the nonuniqueness of the Lagrangian.
Symmetry, Symmetry Breaking and Topology
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Siddhartha Sen
2010-07-01
Full Text Available The ground state of a system with symmetry can be described by a group G. This symmetry group G can be discrete or continuous. Thus for a crystal G is a finite group while for the vacuum state of a grand unified theory G is a continuous Lie group. The ground state symmetry described by G can change spontaneously from G to one of its subgroups H as the external parameters of the system are modified. Such a macroscopic change of the ground state symmetry of a system from G to H correspond to a “phase transition”. Such phase transitions have been extensively studied within a framework due to Landau. A vast range of systems can be described using Landau’s approach, however there are also systems where the framework does not work. Recently there has been growing interest in looking at such non-Landau type of phase transitions. For instance there are several “quantum phase transitions” that are not of the Landau type. In this short review we first describe a refined version of Landau’s approach in which topological ideas are used together with group theory. The combined use of group theory and topological arguments allows us to determine selection rule which forbid transitions from G to certain of its subgroups. We end by making a few brief remarks about non-Landau type of phase transition.
Pseudospin Symmetry as a Bridge between Hadrons and Nuclei
Directory of Open Access Journals (Sweden)
Joseph N. Ginocchio
2016-03-01
Full Text Available Atomic nuclei exhibit approximate pseudospin symmetry. We review the arguments that this symmetry is a relativistic symmetry. The condition for this symmetry is that the sum of the vector and scalar potentials in the Dirac Hamiltonian is a constant. We give the generators of pseudospin symmetry. We review some of the predictions that follow from the insight that pseudospin symmetry has relativistic origins . We show that approximate pseudospin symmetry in nuclei predicts approximate spin symmetry in anti-nucleon scattering from nuclei. Since QCD sum rules predict that the sum of the scalar and vector potentials is small, we discuss the quark origins of pseudospin symmetry in nuclei and spin symmetry in hadrons.
Analytic description of SU(3) lattice thermodynamics within the mass gap approach. I
Gogokhia, V; Vasúth, M
2014-01-01
A general method how to analytically describe and understand $SU(3)$ lattice thermodynamics within the effective potential approach for composite operators properly generalized to finite temperature and density is formulated and used. This makes it possible to introduce into this formalism a dependence on the mass gap, which is responsible for the large-scale dynamical structure of the QCD ground state. The gluon plasma pressure adjusted by this approach to the corresponding lattice data is shown to be a continuously growing function of temperature in the whole temperature range $[0, \\infty)$. The entropy and energy densities have finite jump discontinuities at some characteristic temperature $T_c = 266.5$ MeV with latent heat $\\epsilon_{LH}= 1.41$. This is a firm evidence of the first-order phase transition in $SU(3)$ pure gluon plasma. The heat capacity has a $\\delta$-type singularity (an essential discontinuity) at $T_c$, so that the velocity of sound squared becomes zero at this point. All the independent...
Dynamical symmetries in nuclear structure
International Nuclear Information System (INIS)
In recent years the concept of dynamical symmetries in nuclei has witnessed a renaissance of interest and activity. Much of this work has been developed in the context of the Interacting Boson Approximation (or IBA) model. The appearance and properties of dynamical symmetries in nuclei will be reviewed, with emphasis on their characteristic signatures and on the role of the proton-neutron interaction in their formation, systematics and evolution. 36 refs., 20 figs
International Nuclear Information System (INIS)
The sky uniformity can be noticed in studying the repartition of objects far enough. The sky isotropy description uses space rotations. The group theory elements will allow to give a meaning at the same time precise and general to the word a ''symmetry''. Universe models are reviewed, which must have both of the following qualities: - conformity with the physic known laws; - rigorous symmetry following one of the permitted groups. Each of the models foresees that universe evolution obeys an evolution equation. Expansion and big-bang theory are recalled. Is universe an open or closed space. Universe is also electrically neutral. That leads to a work hypothesis: the existing matter is not given data of universe but it appeared by evolution from nothing. Problem of matter and antimatter is then raised up together with its place in universe
Unification via intermediate symmetry breaking scales with the quartification gauge group
Demaria, A; Volkas, R R
2005-01-01
The idea of quark-lepton universality at high energies has been introduced as a natural extension to the standard model. This is achieved by endowing leptons with new degrees of freedom -- leptonic colour, an analogue of the familiar quark colour. Grand and partially unified models which utilise this new gauge symmetry SU(3)_\\ell have been proposed in the context of the quartification gauge group SU(3)^4. Phenomenologically successful gauge coupling constant unification without supersymmetry has been demonstrated for cases where the symmetry breaking leaves a residual SU(2)_\\ell unbroken. Though attractive, these schemes either incorporate ad hoc discrete symmetries and non-renormalisable mass terms, or achieve only partial unification. We show that grand unified models can be constructed where the quartification group can be broken fully [i.e. no residual SU(2)_\\ell] to the standard model gauge group without requiring additional discrete symmetries or higher dimension operators. These models also automatical...
Global analysis of two-body D →V P decays within the framework of flavor symmetry
Cheng, Hai-Yang; Chiang, Cheng-Wei; Kuo, An-Li
2016-06-01
Two-body charmed meson decays D →V P are studied within the framework of the diagrammatic approach. Under flavor SU(3) symmetry, all the flavor amplitude sizes and their associated strong phases are extracted by performing a χ2 fit. Thanks to the recent measurement of Ds+→π+ρ0 , the magnitudes and the strong phases of the W -annihilation amplitudes AP ,V have been extracted for the first time. As a consequence, the branching fractions of all the D →V P decays are predicted, especially those modes that could not be predicted previously due to the unknown AP ,V. Our working assumption, the flavor SU(3) symmetry, is tested by comparing our predictions with experiment for the singly and doubly Cabibbo-suppressed decay modes based on the flavor amplitudes extracted from the Cabibbo-favored decays using the current data. The predictions for the doubly Cabibbo-suppressed channels are in good agreement with the data, while those for the singly Cabibbo-suppressed decay modes are seen to have flavor SU(3) symmetry breaking effects. We find that the inclusion of SU(3) symmetry breaking in color-allowed and color-suppressed tree amplitudes is needed in general in order to have a better agreement with experiment. Nevertheless, the exact flavor SU(3)-symmetric approach alone is adequate to provide an overall explanation for the current data.
Chiral symmetry breaking and monopoles
Di Giacomo, Adriano; Pucci, Fabrizio
2015-01-01
To understand the relation between the chiral symmetry breaking and monopoles, the chiral condensate which is the order parameter of the chiral symmetry breaking is calculated in the $\\overline{\\mbox{MS}}$ scheme at 2 [GeV]. First, we add one pair of monopoles, varying the monopole charges $m_{c}$ from zero to four, to SU(3) quenched configurations by a monopole creation operator. The low-lying eigenvalues of the Overlap Dirac operator are computed from the gauge links of the normal configurations and the configurations with additional monopoles. Next, we compare the distributions of the nearest-neighbor spacing of the low-lying eigenvalues with the prediction of the random matrix theory. The low-lying eigenvalues not depending on the scale parameter $\\Sigma$ are compared to the prediction of the random matrix theory. The results show the consistency with the random matrix theory. Thus, the additional monopoles do not affect the low-lying eigenvalues. Moreover, we discover that the additional monopoles increa...
Symmetry limit properties of decay amplitudes with mirror matter admixtures
Sánchez-Colón, G; Sanchez-Colon, Gabriel; Garcia, Augusto
2006-01-01
We extend our previous analysis on the symmetry limit properties of non-leptonic and weak radiative decay amplitudes of hyperons in a scheme of mirror matter admixtures in physical hadrons to include the two-body non-leptonic decays of $\\Omega^-$ and the two photon and two pion decays of kaons. We show that the so-called parity-conserving amplitudes predicted for all the decays vanish in the strong flavor SU(3) symmetry limit. We also establish the specific conditions under which the corresponding so-called parity-violating amplitudes vanish in the same limit.
Quasi-dynamical symmetries in the backbending of chromium isotopes
Herrera, Raul A.; Johnson, Calvin W.
2016-01-01
We examine the well-known backbending, or abrupt change in the moment of inertia along the yrast line, in $^{48,49,50}$Cr by decomposing configuration-interaction shell-model wavefunctions into group irreps, using the subgroups $L$ (total orbital angular momentum) and $S$ (total spin) of SU(2), and the groups SU(3) and SU(4). We see strong signatures of quasi-dynamical symmetries--the same or similar decomposition across members of a band--below the backbending, while quasi-dynamical symmetry...
Horizontal symmetries of leptons with a massless neutrino
Joshipura, Anjan S.; PATEL, KETAN M.
2013-01-01
Residual symmetry Gν of neutrino mass matrix with a massless neutrino and embedding of Gν and the residual symmetry Gl of the charged lepton mass matrix into finite discrete groups G is discussed. Massless neutrino results if Gν and hence G are subgroups of U(3) rather than of SU(3). Structure of the resulting leptonic mixing matrix UPMNS is discussed in three specific examples based on groups (a) Σ(3N3), (b) Σ(2N2) and (c) S4(2)≡A4⋊Z4. Σ(3N3) groups are able to reproduce either the second or...
Modular Ground State for SU(8) Symmetry Breaking
Adler, Stephen L
2015-01-01
We elaborate on our recent proposal of a modular ground state structure for the first stage of $SU(8)$ symmetry breaking by a scalar in the 56 representation. We review the arguments for $U(1)$ generator modularity 15, and show that this can lead to a vanishing mass for the $U(1)$ gauge boson, as needed for the symmetry breaking pattern $SU(8) \\supset SU(3) \\times SU(5) \\times U(1)$. We then give a simplified form for the modulo 5 ground state obeying clustering, that we have conjectured to lead from broken $SU(8)$ to the flipped $SU(5)$ model. Generalizations of these results are also given.
Quasi-dynamical symmetries in the backbending of chromium isotopes
Herrera, Raul A
2016-01-01
We examine the well-known backbending, or abrupt change in the moment of inertia along the yrast line, in $^{48,49,50}$Cr by decomposing configuration-interaction shell-model wavefunctions into group irreps, using the subgroups $L$ (total orbital angular momentum) and $S$ (total spin) of SU(2), and the groups SU(3) and SU(4). We see strong signatures of quasi-dynamical symmetries--the same or similar decomposition across members of a band--below the backbending, while quasi-dynamical symmetry is weaker above the bandbending.
Unification via intermediate symmetry breaking scales with the quartification gauge group
International Nuclear Information System (INIS)
The idea of quark-lepton universality at high energies has been introduced as a natural extension to the standard model. This is achieved by endowing leptons with new degrees of freedom--leptonic color, an analogue of the familiar quark color. Grand and partially unified models which utilize this new gauge symmetry SU(3)l have been proposed in the context of the quartification gauge group SU(3)4. Phenomenologically successful gauge coupling constant unification without supersymmetry has been demonstrated for cases where the symmetry breaking leaves a residual SU(2)l unbroken. Though attractive, these schemes either incorporate ad hoc discrete symmetries and nonrenormalizable mass terms, or achieve only partial unification. We show that grand unified models can be constructed where the quartification group can be broken fully [i.e. no residual SU(2)l] to the standard model gauge group without requiring additional discrete symmetries or higher dimension operators. These models also automatically have suppressed nonzero neutrino masses. We perform a systematic analysis of the renormalization-group equations for all possible symmetry breaking routes from SU(3)4→SU(3)qxSU(2)LxU(1)Y. This analysis indicates that gauge coupling unification can be achieved for several different symmetry breaking patterns and we outline the requirements that each gives on the unification scale. We also show that the unification scenarios of those models which leave a residual SU(2)l symmetry are not unique. In both symmetry breaking cases, some of the scenarios require new physics at the TeV scale, while others do not allow for new TeV phenomenology in the fermionic sector
Interacting boson approximation
International Nuclear Information System (INIS)
Lectures notes on the Interacting Boson Approximation are given. Topics include: angular momentum tensors; properties of T/sub i//sup (n)/ matrices; T/sub i//sup (n)/ matrices as Clebsch-Gordan coefficients; construction of higher rank tensors; normalization: trace of products of two s-rank tensors; completeness relation; algebra of U(N); eigenvalue of the quadratic Casimir operator for U(3); general result for U(N); angular momentum content of U(3) representation; p-Boson model; Hamiltonian; quadrupole transitions; S,P Boson model; expectation value of dipole operator; S-D model: U(6); quadratic Casimir operator; an O(5) subgroup; an O(6) subgroup; properties of O(5) representations; quadratic Casimir operator; quadratic Casimir operator for U(6); decomposition via SU(5) chain; a special O(3) decomposition of SU(3); useful identities; a useful property of D/sub αβγ/(α,β,γ = 4-8) as coupling coefficients; explicit construction of T/sub x//sup (2)/ and d/sub αβγ/; D-coefficients; eigenstates of T3; and summary of T = 2 states
Perfect Abelian dominance of confinement in quark-antiquark potential in SU(3) lattice QCD
Suganuma, Hideo; Sakumichi, Naoyuki
2016-01-01
In the context of the dual superconductor picture for the confinement mechanism, we study maximally Abelian (MA) projection of quark confinement in SU(3) quenched lattice QCD with 324 at β=6.4 (i.e., a ≃ 0.058 fm). We investigate the static quark-antiquark potential V(r), its Abelian part VAbel(r) and its off-diagonal part Voff(r), respectively, from the on-axis lattice data. As a remarkable fact, we find almost perfect Abelian dominance for quark confinement, i.e., σAbel ≃ σ for the string tension, on the fine and large-volume lattice. We find also a nontrivial summation relation of V (r) ≃ VAbel(r)+Voff(r).
Three dimensional finite temperature SU(3) gauge theory near the phase transition
Bialas, Piotr; Morel, Andre; Petersson, Bengt
2012-01-01
We have measured the correlation function of Polyakov loops on the lattice in three dimensional SU(3) gauge theory near its finite temperature phase transition. Using a new and powerful application of finite size scaling, we furthermore extend the measurements of the critical couplings to considerably larger values of the lattice sizes, both in the temperature and space directions, than was investigated earlier in this theory. With the help of these measurements we perform a detailed finite size scaling analysis, showing that for the critical exponents of the two dimensional three state Potts model the mass and the susceptibility fall on unique scaling curves. This strongly supports the expectation that the gauge theory is in the same universality class. The Nambu-Goto string model on the other hand predicts that the exponent \
Study of the conformal region of the SU(3) gauge theory with domain-wall fermions
Noaki, J; Ishikawa, K-I; Iwasaki, Y; Yoshie, T
2015-01-01
We investigate the phase structure of the SU(3) gauge theory with $N_f=8$ by numerical simulations employing the massless Domain-Wall fermions.Our aim is to study directly the massless quark region, since it is the most important region to clarify the properties of conformal theories. When the number of flavor is within the conformal window, it is claimed recently with Wilson quarks that there is the conformal region at the small quark mass region in the parameter space in addition to the confining phase and the deconfining phase. We study the properties of the conformal region investing the spatial Polyakov loops and the temporal meson propagators. Our data imply that there is the conformal region, and a phase transition between the confining phase and the conformal region takes place. These results are consistent with the claim that the conformal window is between $7$ and $16$. Progress reports on other related studies are also presented.
First Study for the Pentaquark Potential in SU(3) Lattice QCD
Okiharu, F; Takahashi, T T; Okiharu, Fumiko; Suganuma, Hideo; Takahashi, Toru T
2004-01-01
The static penta-quark (5Q) potential $V_{\\rm 5Q}$ is studied in SU(3) lattice QCD with $16^3\\times 32$ and $\\beta$=6.0 at the quenched level. From the 5Q Wilson loop, $V_{\\rm 5Q}$ is calculated in a gauge-invariant manner, with the smearing method to enhance the ground-state component. $V_{\\rm 5Q}$ is well described by the OGE plus multi-Y Ansatz: a sum of the OGE Coulomb term and the multi-Y-type linear term proportional to the minimal total length of the flux-tube linking the five quarks. Comparing with ${\\rm Q \\bar Q}$ and 3Q potentials, we find a universality of the string tension, $\\sigma_{\\rm Q \\bar Q} \\simeq \\sigma_{\\rm 3Q} \\simeq \\sigma_{\\rm 5Q}$, and the OGE result for Coulomb coefficients.
Perfect Abelian dominance of confinement in quark-antiquark potential in SU(3) lattice QCD
International Nuclear Information System (INIS)
In the context of the dual superconductor picture for the confinement mechanism, we study maximally Abelian (MA) projection of quark confinement in SU(3) quenched lattice QCD with 324 at β=6.4 (i.e., a ≃ 0.058 fm). We investigate the static quark-antiquark potential V(r), its Abelian part VAbel(r) and its off-diagonal part Voff(r), respectively, from the on-axis lattice data. As a remarkable fact, we find almost perfect Abelian dominance for quark confinement, i.e., σAbel ≃ σ for the string tension, on the fine and large-volume lattice. We find also a nontrivial summation relation of V (r) ≃ VAbel(r)+Voff(r)
Magnetic polarizabilities of light mesons in SU(3 lattice gauge theory
Directory of Open Access Journals (Sweden)
E.V. Luschevskaya
2015-09-01
Full Text Available We investigate the ground state energies of neutral pseudoscalar and vector meson in SU(3 lattice gauge theory in the strong abelian magnetic field. The energy of ρ0 meson with zero spin projection sz=0 on the axis of the external magnetic field decreases, while the energies with non-zero spins sz=−1 and +1 increase with the field. The energy of π0 meson decreases as a function of the magnetic field. We calculate the magnetic polarizabilities of pseudoscalar and vector mesons for lattice volume 184. For ρ0 with spin |sz|=1 and π0 meson the polarizabilities in the continuum limit have been evaluated. We do not observe any evidence in favour of tachyonic mode existence.
Small eigenvalues of the SU(3) Dirac operator on the lattice and in Random Matrix Theory
Göckeler, M; Rakow, P E L; Schäfer, A; Wettig, T
1999-01-01
We have calculated complete spectra of the staggered Dirac operator on the lattice in quenched SU(3) gauge theory for \\beta = 5.4 and various lattice sizes. The microscopic spectral density, the distribution of the smallest eigenvalue, and the two-point spectral correlation function are analyzed. We find the expected agreement of the lattice data with universal predictions of the chiral unitary ensemble of random matrix theory up to a certain energy scale, the Thouless energy. The deviations from the universal predictions are determined using the disconnected scalar susceptibility. We find that the Thouless energy scales with the lattice size as expected from theoretical arguments making use of the Gell-Mann--Oakes--Renner relation.
QQqq Four-Quark Bound States in Chiral SU(3) Quark Model
Institute of Scientific and Technical Information of China (English)
ZHANG Ming; ZHANG Hai-Xia; ZHANG Zong-Ye
2008-01-01
The possibility of QQqq heavy-light four-quark bound states has been analyzed by means of the chiral SU(3) quark model, where Q is the heavy quark (c or b) and q is the light quark (u, d, or s). We obtain a bound state for the bbnn configuration with quantum number JP=1+, I=0 and for the ccnn (JP=1+, I=0) configuration, which is not bound but slightly above the D*D* threshold (n is u or d quark). Meanwhile, we also conclude that a weakly bound state in bbnn system can also be found without considering the chiral quark interactions between the two light quarks, yet its binding energy is weaker than that with the chiral quark interactions.
The renormalization group step scaling function of the 2-flavor SU(3) sextet model
Hasenfratz, Anna; Huang, Cynthia Yu-Han
2015-01-01
We investigate the discrete $\\beta$ function of the 2-flavor SU(3) sextet model using the finite volume gradient flow scheme. Our results, using clover improved nHYP smeared Wilson fermions, follow the (non-universal) 4-loop $\\overline{\\textrm{MS}}$ perturbative predictions closely up to $g^2 \\approx 5.5$, the strongest coupling reached in our simulation. At strong couplings the results are in tension with a recently published work using the same gradient flow renormalization scheme with staggered fermions. Since these calculations define the discrete $\\beta$ function in the same continuum renormalization scheme, they should lead to the same continuum predictions, irrespective of the lattice fermion action. In order to test systematic effects in our computation we compare two different lattice operators, three different flow definitions, and two volume extrapolations. We find agreement among these different approaches in the continuum limit when the gradient flow parameter $c\\gtrsim0.35$. Considering the pote...
Bound States of (Anti-)Scalar-Quarks in $SU(3)_{c}$ Lattice QCD
Iida, H; Takahashi, T T
2007-01-01
Light scalar-quarks \\phi (colored scalar particles or idealized diquarks) and their color-singlet hadronic states are studied with quenched SU(3)_c lattice QCD in terms of mass generation. We investigate ``scalar-quark mesons'' \\phi^\\dagger \\phi and ``scalar-quark baryons'' \\phi\\phi\\phi as the bound states of scalar-quarks \\phi. We also investigate the bound states of scalar-quarks \\phi and quarks \\psi, i.e., \\phi^\\dagger \\psi, \\psi\\psi\\phi and \\phi\\phi\\psi, which we name ``chimera hadrons''. All the new-type hadrons including \\phi are found to have a large mass due to large quantum corrections by gluons, even for zero bare scalar-quark mass m_\\phi=0 at a^{-1}\\sim 1{\\rm GeV}. We conjecture that all colored particles generally acquire a large effective mass due to dressed gluon effects.
Nonperturbative β function of eight-flavor SU(3) gauge theory
Hasenfratz, Anna; Schaich, David; Veernala, Aarti
2015-06-01
We present a new lattice study of the discrete β function for SU(3) gauge theory with N f = 8 massless flavors of fermions in the fundamental representation. Using the gradient flow running coupling, and comparing two different nHYP-smeared staggered lattice actions, we calculate the 8-flavor step-scaling function at significantly stronger couplings than were previously accessible. Our continuum-extrapolated results for the discrete β function show no sign of an IR fixed point up to couplings of g 2 ≈ 14. At the same time, we find that the gradient flow coupling runs much more slowly than predicted by two-loop perturbation theory, reinforcing previous indications that the 8-flavor system possesses nontrivial strongly coupled IR dynamics with relevance to BSM phenomenology.
Nonperturbative beta function of eight-flavor SU(3) gauge theory
Hasenfratz, Anna; Veernala, Aarti
2014-01-01
We present a new lattice study of the discrete beta function for SU(3) gauge theory with Nf=8 massless flavors of fermions in the fundamental representation. Using the gradient flow running coupling, and comparing two different nHYP-smeared staggered lattice actions, we calculate the 8-flavor step-scaling function at significantly stronger couplings than were previously accessible. Our continuum-extrapolated results for the discrete beta function show no sign of an IR fixed point up to couplings of g^2~14. At the same time, we find that the gradient flow coupling runs much more slowly than predicted by two-loop perturbation theory, reinforcing previous indications that the 8-flavor system possesses nontrivial strongly coupled IR dynamics with relevance to BSM phenomenology.
The eightfold way model, the SU(3)-flavor model and the medium-strong interaction
Abbas, Syed Afsar
2015-03-01
Lack of any baryon number in the eightfold way model, and its intrinsic presence in the SU(3)-flavor model, has been a puzzle since the genesis of these models in 1961-1964. First we show that the conventional popular understanding of this puzzle is actually fundamentally wrong, and hence the problem being so old, begs urgently for resolution. In this paper we show that the issue is linked to the way that the adjoint representation is defined mathematically for a Lie algebra, and how it manifests itself as a physical representation. This forces us to distinguish between the global and the local charges and between the microscopic and the macroscopic models. As a bonus, a consistent understanding of the hitherto mysterious medium-strong interaction is achieved. We also gain a new perspective on how confinement arises in quantum chromodynamics.
Drinfeld Doubles for Finite Subgroups of SU(2) and SU(3) Lie Groups
Coquereaux, Robert; Zuber, Jean-Bernard
2013-05-01
Drinfeld doubles of finite subgroups of SU(2) and SU(3) are investigated in detail. Their modular data - S, T and fusion matrices - are computed explicitly, and illustrated by means of fusion graphs. This allows us to reexamine certain identities on these tensor product or fusion multiplicities under conjugation of representations that had been discussed in our recent paper [J. Phys. A: Math. Theor. 44 (2011), 295208, 26 pages], proved to hold for simple and affine Lie algebras, and found to be generally wrong for finite groups. It is shown here that these identities fail also in general for Drinfeld doubles, indicating that modularity of the fusion category is not the decisive feature. Along the way, we collect many data on these Drinfeld doubles which are interesting for their own sake and maybe also in a relation with the theory of orbifolds in conformal field theory.
Drinfeld Doubles for Finite Subgroups of SU(2 and SU(3 Lie Groups
Directory of Open Access Journals (Sweden)
Robert Coquereaux
2013-05-01
Full Text Available Drinfeld doubles of finite subgroups of SU(2 and SU(3 are investigated in detail. Their modular data – S, T and fusion matrices – are computed explicitly, and illustrated by means of fusion graphs. This allows us to reexamine certain identities on these tensor product or fusion multiplicities under conjugation of representations that had been discussed in our recent paper [J. Phys. A: Math. Theor. 44 (2011, 295208, 26 pages], proved to hold for simple and affine Lie algebras, and found to be generally wrong for finite groups. It is shown here that these identities fail also in general for Drinfeld doubles, indicating that modularity of the fusion category is not the decisive feature. Along the way, we collect many data on these Drinfeld doubles which are interesting for their own sake and maybe also in a relation with the theory of orbifolds in conformal field theory.
Drinfeld doubles for finite subgroups of SU(2) and SU(3) Lie groups
Coquereaux, Robert
2014-01-01
Drinfeld doubles of finite subgroups of SU(2) and SU(3) are investigated in detail. Their modular data --S, T and fusion matrices-- are computed explicitly, and illustrated by means of fusion graphs. This allows us to reexamine certain identities on these tensor product or fusion multiplicities under conjugation of representations that had been discussed in a recent paper [Coquereaux-Zuber 2011 arXiv:1103.2943], proved to hold for simple and affine Lie algebras, and found to be generally wrong for finite groups. It is shown here that these identities fail also in general for Drinfeld doubles, indicating that modularity of the fusion category is not the decisive feature. Along the way, we collect many data on these Drinfeld doubles and make a certain number of curious observations.
Fate of the conformal fixed point with twelve massless fermions and SU(3) gauge group
Fodor, Zoltan; Kuti, Julius; Mondal, Santanu; Nogradi, Daniel; Wong, Chik Him
2016-01-01
We report new results on the conformal properties of an important strongly coupled gauge theory, a building block of composite Higgs models beyond the Standard Model. With twelve massless fermions in the fundamental representation of the SU(3) color gauge group, an infrared fixed point of the $\\beta$-function was recently reported in the theory (Cheng:2014jba) with uncertainty in the location of the critical gauge coupling inside the narrow $[ 6.0
Consistency between SU(3) and SU(2) chiral perturbation theory for the nucleon mass
Ren, Xiu-Lei; Geng, Li-Sheng; Ledwig, T; Meng, Jie; Vacas, M J Vicente
2016-01-01
Treating the strange quark mass as a heavy scale compared to the light quark mass, we perform a matching of the nucleon mass in the SU(3) sector to the two-flavor case in covariant baryon chiral perturbation theory. The validity of the $19$ low-energy constants appearing in the octet baryon masses up to next-to-next-to-next-to-leading order~\\cite{Ren:2014vea} is supported by comparing the effective parameters (the combinations of the $19$ couplings) with the corresponding low-energy constants in the SU(2) sector~\\cite{Alvarez-Ruso:2013fza}. In addition, it is shown that the dependence of the effective parameters and the pion-nucleon sigma term on the strange quark mass is relatively weak around its physical value, thus providing support to the assumption made in Ref.~\\cite{Alvarez-Ruso:2013fza}.
On the strong-coupling spectrum of pure SU(3) Seiberg-Witten theory
International Nuclear Information System (INIS)
We consider the two complex dimensional moduli space of supersymmetric vacua for low energy effective N=2 SYM with gauge group SU(3). We describe, at the topological level, a consistent model of how the relevant curves of marginal stability (CMS) intertwine with the branch cuts to partition the moduli space into pieces carrying different BPS spectra. At strong coupling we find connected cores which carry a smaller BPS spectrum than that at weak coupling. At the strongest coupling we find double cores which carry a finite BPS spectrum. These include not only states one can deduce from the monodromy group, but three states, bounded away from weak coupling, each of which we interpret as a bound state of two BPS gauge bosons. We find new BPS states at weak coupling corresponding to a excitations of a state with magnetic charge a simple co-root, with respect to the other simple root direction. (author)
Critical properties of the Z(3) interface in (2+1)-D SU(3) gauge theory
International Nuclear Information System (INIS)
We study the interface between two different Z(3) vacua in the deconfined phase of SU(3) pure gauge theory in 2+1 dimensions just above the critical temperature. In simulations of the Euclidean lattice gauge theory formulation of the system we measure the fluctuations of the interface as the critical temperature is approached and as a function of system size. We show that the intrinsic width of the interface remains small even very close to the critical temperature. Some dynamical exponents which govern the interaction of the interface with our Monte Carlo algorithm are also estimated. We conclude that the Z(3) interface has properties broadly similar to those in many other comparable statistical mechanical systems. (orig.)
Diophantine approximations on fractals
Einsiedler, Manfred; Shapira, Uri
2009-01-01
We exploit dynamical properties of diagonal actions to derive results in Diophantine approximations. In particular, we prove that the continued fraction expansion of almost any point on the middle third Cantor set (with respect to the natural measure) contains all finite patterns (hence is well approximable). Similarly, we show that for a variety of fractals in [0,1]^2, possessing some symmetry, almost any point is not Dirichlet improvable (hence is well approximable) and has property C (after Cassels). We then settle by similar methods a conjecture of M. Boshernitzan saying that there are no irrational numbers x in the unit interval such that the continued fraction expansions of {nx mod1 : n is a natural number} are uniformly eventually bounded.
Covariant approximation averaging
Shintani, Eigo; Blum, Thomas; Izubuchi, Taku; Jung, Chulwoo; Lehner, Christoph
2014-01-01
We present a new class of statistical error reduction techniques for Monte-Carlo simulations. Using covariant symmetries, we show that correlation functions can be constructed from inexpensive approximations without introducing any systematic bias in the final result. We introduce a new class of covariant approximation averaging techniques, known as all-mode averaging (AMA), in which the approximation takes account of contributions of all eigenmodes through the inverse of the Dirac operator computed from the conjugate gradient method with a relaxed stopping condition. In this paper we compare the performance and computational cost of our new method with traditional methods using correlation functions and masses of the pion, nucleon, and vector meson in $N_f=2+1$ lattice QCD using domain-wall fermions. This comparison indicates that AMA significantly reduces statistical errors in Monte-Carlo calculations over conventional methods for the same cost.
Peters, Kirstin
2010-01-01
A well-known result by Palamidessi tells us that {\\pi}mix (the {\\pi}-calculus with mixed choice) is more expressive than {\\pi}sep (its subset with only separate choice). The proof of this result argues with their different expressive power concerning leader election in symmetric networks. Later on, Gorla of- fered an arguably simpler proof that, instead of leader election in symmetric networks, employed the reducibility of "incestual" processes (mixed choices that include both enabled senders and receivers for the same channel) when running two copies in parallel. In both proofs, the role of breaking (ini- tial) symmetries is more or less apparent. In this paper, we shed more light on this role by re-proving the above result-based on a proper formalization of what it means to break symmetries-without referring to another layer of the distinguishing problem domain of leader election. Both Palamidessi and Gorla rephrased their results by stating that there is no uniform and reason- able encoding from {\\pi}mix i...
Strongly broken Peccei-Quinn symmetry in the early Universe
Energy Technology Data Exchange (ETDEWEB)
Takahashi, Fuminobu [Department of Physics, Tohoku University,Sendai, Miyagi 980-8578 (Japan); Kavli IPMU (WPI), TODIAS, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan); Yamada, Masaki [Kavli IPMU (WPI), TODIAS, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan); Institute for Cosmic Ray Research, ICRR, The University of Tokyo,Kashiwa, Chiba 277-8582 (Japan)
2015-10-06
We consider QCD axion models where the Peccei-Quinn symmetry is badly broken by a larger amount in the past than in the present, in order to avoid the axion isocurvature problem. Specifically we study supersymmetric axion models where the Peccei-Quinn symmetry is dynamically broken by either hidden gauge interactions or the SU(3){sub c} strong interactions whose dynamical scales are temporarily enhanced by the dynamics of flat directions. The former scenario predicts a large amount of self-interacting dark radiation as the hidden gauge symmetry is weakly coupled in the present Universe. We also show that the observed amount of baryon asymmetry can be generated by the QCD axion dynamics via spontaneous baryogenesis. We briefly comment on the case in which the PQ symmetry is broken by a non-minimal coupling to gravity.
Strongly broken Peccei-Quinn symmetry in the early Universe
Takahashi, Fuminobu
2015-01-01
We consider QCD axion models where the Peccei-Quinn symmetry is badly broken by a larger amount in the past than in the present, in order to avoid the axion isocurvature problem. Specifically we study supersymmetric axion models where the Peccei-Quinn symmetry is dynamically broken by either hidden gauge interactions or the $SU(3)_c$ strong interactions whose dynamical scales are temporarily enhanced by the dynamics of flat directions. The former scenario predicts a large amount of self-interacting dark radiation as the hidden gauge symmetry is weakly coupled in the present Universe. We also show that the observed amount of baryon asymmetry can be generated by the QCD axion dynamics via spontaneous baryogenesis. We briefly comment on the case in which the PQ symmetry is broken by a non-minimal coupling to gravity.
Energy Technology Data Exchange (ETDEWEB)
Campos, Francisco Antonio Pena
1995-12-31
The present work consists in a 1/N expansion of extended version of the SU(3) Nambu-Jona-Lasinio model in the context of the Functional Integral. The gap equations, meson propagators, triangle diagram, etc, appear quite naturally as different orders in the expansion. The new features of this approach is the inclusion of high order corrections in the 1/N leading orders, which have never included in the previous one. The method also allows for the construction of a chiral Lagrangian of interacting mesons based on the SU(3) NJL model, here obtained for the first time. (author) 32 refs., 11 figs., 5 tabs.
SU(3) breaking corrections to the D, D⁎, B, and B⁎ decay constants
International Nuclear Information System (INIS)
We report on a first next-to-next-to-leading order calculation of the decay constants of the D (D⁎) and B (B⁎) mesons using a covariant formulation of chiral perturbation theory. It is shown that, using the state-of-the-art lattice QCD results on fDs/fD as input, one can predict quantitatively the ratios of fDs⁎/fD⁎, fBs/fB, and fBs⁎/fB⁎ taking into account heavy-quark spin-flavor symmetry breaking effects on the relevant low-energy constants. The predicted relations between these ratios, fDs⁎/fD⁎Ds/fD and fBs/fB>fDs/fD, and their light-quark mass dependence should be testable in future lattice QCD simulations, providing a stringent test of our understanding of heavy quark spin-flavor symmetry, chiral symmetry and their breaking patterns.
International Nuclear Information System (INIS)
The weak-interaction contributions to the anomalous magnetic and electric dipole form factors of muon, electron and heavy leptons as well as their static values have been calculated in the framework of the Lee-Weinberg SU(3)xU(1) unified model of weak and electromagnetic interactions. It has been shown that the X1, X2 neutral gauge boson exchange diagrams, which may be responsible for the CP violation effects in the SU(3)xU(1) model, yield the leading contribution to weak-interaction correction to the electron and muon magnetic moments in comparison with contributions of the rest W, U, Y, Z boson exchange diagrams. The essential limitations on the SU(3)xU(1) model parameters have been obtained using the experimental data concerning the anomalous magnetic moment of muon and electric dipole moment of electron
Structures of (ΩΩ)0+ and (([1])Ω)1+ in Extended Chiral SU(3) Quark Model
Institute of Scientific and Technical Information of China (English)
ZHANG Zong-Ye; YU You-Wen; DAI Lian-Rong
2003-01-01
The structures of (ΩΩ)0+ and (([1])Ω)1+ are studied in the extended chiral SU(3) quark model in whichvector meson exchanges are included. The effect from the vector meson fields is very similar to that from the one-gluonexchange (OGE) interaction. Both in the chiral SU(3) quark model and in the extended chiral SU(3) quark model,di-omega (ΩΩ)0+ is always deeply bound, with over one hundred MeV binding energy, and (([1])Ω)1+ 's binding energyis around 20 MeV. An analysis shows that the quark exchange effect plays a very important role for making di-omega(ΩΩ)0+ deeply bound.
Symmetry Breaking in Finite Volume
Institute of Scientific and Technical Information of China (English)
LIU Chuan
2000-01-01
Spontaneous symmetry breaking is a cooperative phenomenon for systems with infinitely many degrees of freedom and it plays an essential role in quantum field theories. Lattice O(N) model is studied within the Hamiltonian approach using an adiabatic approximation. It is shown that the low-lying spectrum of the system in the broken phase can be understood by using the adiabatic, or Born-Oppenheimer approximation, which turns out to become an expansion in the inverse power of volume. In the infinite volume limit, the symmetry is broken while in the finite volume the slow rotation of the zero-momentum mode restores the symmetry and gives rise to the rotator spectrum, which has been observed in realistic Monte Carlo simulations.
Niven, Ivan
2008-01-01
This self-contained treatment originated as a series of lectures delivered to the Mathematical Association of America. It covers basic results on homogeneous approximation of real numbers; the analogue for complex numbers; basic results for nonhomogeneous approximation in the real case; the analogue for complex numbers; and fundamental properties of the multiples of an irrational number, for both the fractional and integral parts.The author refrains from the use of continuous fractions and includes basic results in the complex case, a feature often neglected in favor of the real number discuss
Instantons and chiral symmetry breaking
International Nuclear Information System (INIS)
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.)
CP and other Symmetries of Symmetries
Trautner, Andreas
2016-01-01
Outer automorphisms of symmetries ("symmetries of symmetries") in relativistic quantum field theories are studied, including charge conjugation (C), space-reflection (P) , and time-reversal (T) transformations. The group theory of outer automorphisms is pedagogically introduced and it is shown that CP transformations are special outer automorphisms of the global, local, and space-time symmetries of a theory. It is shown that certain discrete groups allow for a group theoretical prediction of parameter independent CP violating complex phases with fixed geometrical values. The remainder of this thesis pioneers the study of outer automorphisms which are not related to C, P, or T. It is shown how outer automorphisms, in general, relate symmetry invariants and, in theories with spontaneous symmetry breaking, imply relations between different vacuum expectation values. Thereby, outer automorphisms can give rise to emergent symmetries. An example model with a discrete symmetry and three copies of the Standard Model ...
Venderbos, J. W. F.
2016-03-01
In this work we introduce a symmetry classification for electronic density waves which break translational symmetry due to commensurate wave-vector modulations. The symmetry classification builds on the concept of extended point groups: symmetry groups which contain, in addition to the lattice point group, translations that do not map the enlarged unit cell of the density wave to itself, and become "nonsymmorphic"-like elements. Multidimensional representations of the extended point group are associated with degenerate wave vectors. Electronic properties such as (nodal) band degeneracies and topological character can be straightforwardly addressed, and often follow directly. To further flesh out the idea of symmetry, the classification is constructed so as to manifestly distinguish time-reversal invariant charge (i.e., site and bond) order, and time-reversal breaking flux order. For the purpose of this work, we particularize to spin-rotation invariant density waves. As a first example of the application of the classification we consider the density waves of a simple single- and two-orbital square lattice model. The main objective, however, is to apply the classification to two-dimensional (2D) hexagonal lattices, specifically the triangular and the honeycomb lattices. The multicomponent density waves corresponding to the commensurate M -point ordering vectors are worked out in detail. To show that our results generally apply to 2 D hexagonal lattices, we develop a general low-energy SU(3 ) theory of (spinless) saddle-point electrons.
Theory of spontaneously broken gauge family symmetry and its cosmological consequences
International Nuclear Information System (INIS)
The SU(2) U(1) SU(3)H model with SU(3)H being spontaneously broken local family symmetry is considered as a simplest version of realistic quantum flavourdynamics, giving reasonable explanation of the mass hierarchy and mixing pattern of quarks and leptons. The model predicts: existence of the neutrino Majorana masses with regular hierarchy, existence of familon being simultaneously invisible axion (or arion) and majoron, relationship between neutrino lifetimes relative to familon decays. Thereby, the model provides the unified physical ground for all the main types of dark matter, considered in the theory of large scale structure of the Universe
Developing and testing the density of states FFA method in the SU(3) spin model
Giuliani, Mario; Törek, Pascal
2016-01-01
The Density of States Functional Fit Approach (DoS FFA) is a recently proposed modern density of states technique suitable for calculations in lattice field theories with a complex action problem. In this article we present an exploratory implementation of DoS FFA for the SU(3) spin system at finite chemical potential $\\mu$ - an effective theory for the Polyakov loop. This model has a complex action problem similar to the one of QCD but also allows for a dual simulation in terms of worldlines where the complex action problem is solved. Thus we can compare the DoS FFA results to the reference data from the dual simulation and assess the performance of the new approach. We find that the method reproduces the observables from the dual simulation for a large range of $\\mu$ values, including also phase transitions, illustrating that DoS FFA is an interesting approach for exploring phase diagrams of lattice field theories with a complex action problem.
Latent heat at the first order phase transition point of SU(3) gauge theory
Shirogane, Mizuki; Iwami, Ryo; Kanaya, Kazuyuki; Kitazawa, Masakiyo
2016-01-01
We calculate the energy gap (latent heat) and pressure gap between the hot and cold phases of the SU(3) gauge theory at the first order deconfining phase transition point. We perform simulations around the phase transition point with the lattice size in the temporal direction Nt=6, 8 and 12 and extrapolate the results to the continuum limit. We also investigate the spatial volume dependence. The energy density and pressure are evaluated by the derivative method with non-perturabative anisotropy coefficients. We adopt a multi-point reweighting method to determine the anisotropy coefficients. We confirm that the anisotropy coefficients approach the perturbative values as Nt increases. We find that the pressure gap vanishes at all values of Nt when the non-perturbative anisotropy coefficients are used. The spatial volume dependence in the latent heat is found to be small on large lattices. Performing extrapolation to the continuum limit, we obtain $ \\Delta \\epsilon/T^4 = 0.75 \\pm 0.17 $ and $ \\Delta (\\epsilon -3...
Latent heat at the first order phase transition point of SU(3) gauge theory
Shirogane, Mizuki; Ejiri, Shinji; Iwami, Ryo; Kanaya, Kazuyuki; Kitazawa, Masakiyo; WHOT-QCD Collaboration
2016-07-01
We calculate the energy gap (latent heat) and pressure gap between the hot and cold phases of the SU(3) gauge theory at the first order deconfining phase transition point. We perform simulations around the phase transition point with the lattice size in the temporal direction Nt=6 , 8 and 12 and extrapolate the results to the continuum limit. We also investigate the spatial volume dependence. The energy density and pressure are evaluated by the derivative method with nonperturabative anisotropy coefficients. We adopt a multipoint reweighting method to determine the anisotropy coefficients. We confirm that the anisotropy coefficients approach the perturbative values as Nt increases. We find that the pressure gap vanishes at all values of Nt when the nonperturbative anisotropy coefficients are used. The spatial volume dependence in the latent heat is found to be small on large lattices. Performing extrapolation to the continuum limit, we obtain Δ ɛ /T4=0.75 ±0.17 and Δ (ɛ -3 p )/T4=0.623 ±0.056 .
Quasi-integrable deformations of the $SU(3)$ Affine Toda Theory
Ferreira, Luiz A; Zakrzewski, Wojtek J
2016-01-01
We consider deformations of the $SU(3)$ Affine Toda theory (AT) and investigate the integrability properties of the deformed theories. We find that for some special deformations all conserved quantities change to being conserved only asymptotically, {\\it i.e.} in the process of the scattering of two solitons these charges do vary in time, but they return, after the scattering, to the values they had prior to the scattering. This phenomenon, which we have called quasi-integrability, is related to special properties of the two-soliton solutions under space-time parity transformations. Some properties of the AT solitons are discussed, especially those involving interesting static multi-soliton solutions. We support our analytical studies with detailed numerical ones in which the time evolution has been simulated by the 4th order Runge-Kutta method. We find that for some perturbations the solitons repel and for the others they form a quasi-bound state. When we send solitons towards each other they can repel when ...
Stable hybrid stars within a SU(3) quark-meson-model
Zacchi, Andreas; Hanauske, Matthias; Schaffner-Bielich, Jürgen
2016-03-01
The inner regions of the most massive compact stellar objects might be occupied by a phase of quarks. Since the observations of the massive pulsars PSR J1614-2230 and PSR J 0348 +0432 with about two solar masses, the equations of state constructing relativistic stellar models have to be constrained respecting these new limits. We discuss stable hybrid stars, i.e. compact objects with an outer layer composed of nuclear matter and with a core consisting of quark matter (QM). For the outer nuclear layer we utilize a density dependent nuclear equation of state and we use a chiral SU(3) quark-meson model with a vacuum energy pressure to describe the object's core. The appearance of a disconnected mass-radius branch emerging from the hybrid star branch implies the existence of a third family of compact stars, so-called twin stars. Twin stars did not emerge as the transition pressure has to be relatively small with a large jump in energy density, which could not be satisfied within our approach. This is, among other reasons, due to the fact that the speed of sound in QM has to be relatively high, which can be accomplished by an increase of the repulsive coupling. This increase on the other hand yields transition pressures that are too high for twins stars to appear.
Stable hybrid stars within a SU(3) Quark-Meson-Model
Zacchi, Andreas; Schaffner-Bielich, Jürgen
2015-01-01
The inner regions of the most massive compact stellar objects might be occupied by a phase of quarks. Since the observations of the massive pulsars PSR J1614-2230 and of PSR J0348+0432 with about two solar masses, the equations of state constructing relativistic stellar models have to be constrained respecting these new limits. We discuss stable hybrid stars, i.e. compact objects with an outer layer composed of nuclear matter and with a core consisting of quark matter (QM). For the outer nuclear layer we utilize a density dependent nuclear equation of state and we use a chiral SU(3) Quark-Meson model with a vacuum energy pressure to describe the objects core. The appearance of a disconnected mass-radius branch emerging from the hybrid star branch implies the existence of a third family of compact stars, so called twin stars. Twin stars did not emerge as the transition pressure has to be relatively small with a large jump in energy density, which could not be satisfied within our approach. This is, among other...
Investigation of the scalar spectrum in SU(3) with eight degenerate flavors
Rinaldi, Enrico
2015-01-01
The Lattice Strong Dynamics collaboration is investigating the properties of a SU(3) gauge theory with $N_f = 8$ light fermions on the lattice. We measure the masses of the lightest pseudoscalar, scalar and vector states using simulations with the nHYP staggered-fermion action on large volumes and at small fermion masses, reaching $M_{\\rho}/M_{\\pi} \\approx 2.2$. The axial-vector meson and the nucleon are also studied for the same range of fermion masses. One of the interesting features of this theory is the dynamical presence of a light flavor-singlet scalar state with $0^{++}$ quantum numbers that is lighter than the vector resonance and has a mass consistent with the one of the pseudoscalar state for the whole fermion mass range explored. We comment on the existence of such state emerging from our lattice simulations and on the challenges of its analysis. Moreover we highlight the difficulties in pursuing simulations in the chiral regime of this theory using large volumes.
Asymptotic behavior of the ghost propagator in SU3 lattice gauge theory
Boucaud, P; Le Yaouanc, A; Lokhov, A Y; Micheli, J; Pène, O; Rodríguez-Quintero, J; Roiesnel, C; Boucaud, Ph.
2005-01-01
We study the asymptotic behavior of the ghost propagator in the quenched SU(3) lattice gauge theory with Wilson action. The study is performed on lattices with a physical volume fixed around 1.6 fm and different lattice spacings: 0.100 fm, 0.070 fm and 0.055 fm. We implement an efficient algorithm for computing the Faddeev-Popov operator on the lattice. We are able to extrapolate the lattice data for the ghost propagator towards the continuum and to show that the extrapolated data on each lattice can be described up to four-loop perturbation theory from 2.0 GeV to 6.0 GeV. The three-loop values are consistent with those extracted from previous perturbative studies of the gluon propagator. However the effective $\\Lambda_{\\ms}$ scale which reproduces the data does depend strongly upon the order of perturbation theory and on the renormalization scheme used in the parametrization. We show how the truncation of the perturbative series can account for the magnitude of the dependency in this energy range. The contri...
Properties of Scalar-Quark Systems in SU(3)c Lattice QCD
Iida, Hideaki; Suganuma, Hideo
2008-01-01
We perform the first study for the bound states of colored scalar particles $\\phi$ ("scalar quarks") in terms of mass generation with quenched SU(3)$_c$ lattice QCD. We investigate the bound states of $\\phi$, $\\phi^\\dagger\\phi$ and $\\phi\\phi\\phi$ ("scalar-quark hadrons"), as well as the bound states of $\\phi$ and quarks $\\psi$, i.e., $\\phi^\\dagger\\psi$, $\\psi\\psi\\phi$ and $\\phi\\phi\\psi$ ("chimera hadrons"). All these new-type hadrons including $\\phi$ have a large mass of several GeV due to large quantum corrections by gluons, even for zero bare scalar-quark mass $m_\\phi=0$ at $a^{-1}\\sim 1{\\rm GeV}$. We find a similar $m_\\psi$-dependence between $\\phi^\\dagger\\psi$ and $\\phi\\phi\\psi$, which indicates their similar structure due to the large mass of $\\phi$. From this study, we conjecture that all colored particles generally acquire a large effective mass due to dressed gluons.
On the cosmology of type IIA compactifications on SU(3)-structure manifolds
Caviezel, Claudio; Koerber, Paul; Körs, Simon; Lüst, Dieter; Wrase, Timm; Zagermann, Marco
2009-04-01
We study cosmological properties of type IIA compactifications on orientifolds of SU(3)-structure manifolds with non-vanishing geometric flux. These compactifications give rise to effective 4D Script N = 1 supergravity theories that do not fall under some recently-proven no-go theorems against de Sitter vacua and slow-roll inflation. Focusing on a well-understood class of models based on coset spaces, however, we can use a refined no-go theorem that rules out de Sitter vacua and slow-roll inflation in all but one case. The refined no-go theorem uses the dilaton and a specific linear combination of the Kähler moduli, which is different from the overall volume modulus. It puts a lower bound on the first slow-roll parameter: epsilon >= 2. The only case not ruled out is the manifold SU(2) × SU(2), for which we indeed find critical points with epsilon numerically zero. However, all the points we could find have a tachyon corresponding to an eta-parameter η lesssim -2.4.
Gedanken Worlds without Higgs: QCD-Induced Electroweak Symmetry Breaking
Energy Technology Data Exchange (ETDEWEB)
Quigg, Chris; /Fermilab /Karlsruhe U., TTP; Shrock, Robert; /YITP, Stony Brook
2009-01-01
To illuminate how electroweak symmetry breaking shapes the physical world, we investigate toy models in which no Higgs fields or other constructs are introduced to induce spontaneous symmetry breaking. Two models incorporate the standard SU(3){sub c} {circle_times} SU(2){sub L} {circle_times} U(1){sub Y} gauge symmetry and fermion content similar to that of the standard model. The first class--like the standard electroweak theory--contains no bare mass terms, so the spontaneous breaking of chiral symmetry within quantum chromodynamics is the only source of electroweak symmetry breaking. The second class adds bare fermion masses sufficiently small that QCD remains the dominant source of electroweak symmetry breaking and the model can serve as a well-behaved low-energy effective field theory to energies somewhat above the hadronic scale. A third class of models is based on the left-right-symmetric SU(3){sub c} {circle_times} SU(2){sub L} {circle_times} SU(2){sub R} {circle_times} U(1)B?L gauge group. In a fourth class of models, built on SU(4){sub PS} {circle_times} SU(2){sub L} {circle_times} SU(2){sub R} gauge symmetry, lepton number is treated as a fourth color. Many interesting characteristics of the models stem from the fact that the effective strength of the weak interactions is much closer to that of the residual strong interactions than in the real world. The Higgs-free models not only provide informative contrasts to the real world, but also lead us to consider intriguing issues in the application of field theory to the real world.
Rosensteel, George
1995-01-01
Riemann ellipsoids model rotating galaxies when the galactic velocity field is a linear function of the Cartesian coordinates of the galactic masses. In nuclear physics, the kinetic energy in the linear velocity field approximation is known as the collective kinetic energy. But, the linear approximation neglects intrinsic degrees of freedom associated with nonlinear velocity fields. To remove this limitation, the theory of symplectic dynamical symmetry is developed for classical systems. A classical phase space for a self-gravitating symplectic system is a co-adjoint orbit of the noncompact group SP(3,R). The degenerate co-adjoint orbit is the 12 dimensional homogeneous space Sp(3,R)/U(3), where the maximal compact subgroup U(3) is the symmetry group of the harmonic oscillator. The Hamiltonian equations of motion on each orbit form a Lax system X = (X,F), where X and F are elements of the symplectic Lie algebra. The elements of the matrix X are the generators of the symplectic Lie algebra, viz., the one-body collective quadratic functions of the positions and momenta of the galactic masses. The matrix F is composed from the self-gravitating potential energy, the angular velocity, and the hydostatic pressure. Solutions to the hamiltonian dynamical system on Sp(3,R)/U(3) are given by symplectic isospectral deformations. The Casimirs of Sp(3,R), equal to the traces of powers of X, are conserved quantities.
Approximate Representations and Approximate Homomorphisms
Moore, Cristopher; Russell, Alexander
2010-01-01
Approximate algebraic structures play a defining role in arithmetic combinatorics and have found remarkable applications to basic questions in number theory and pseudorandomness. Here we study approximate representations of finite groups: functions f:G -> U_d such that Pr[f(xy) = f(x) f(y)] is large, or more generally Exp_{x,y} ||f(xy) - f(x)f(y)||^2$ is small, where x and y are uniformly random elements of the group G and U_d denotes the unitary group of degree d. We bound these quantities i...
Symmetry vs. Chaos in collective dynamics
International Nuclear Information System (INIS)
Models of nuclear collective dynamics are used to study the interplay of order (approximate dynamical symmetry) and chaos in general physical systems. We report on some recent results obtained within the interacting boson model and the geometric model. (author)
Pairs of charged heavy fermions from an $SU(3)_{L}(-)U(1)_{N}$ model at $e^{+}e^{-}$ colliders
Cieza-Montalvo, J E; 10.1103/PhysRevD.67.075022
2003-01-01
We investigate the production, backgrounds, and signatures of pairs of charged heavy fermions using the SU(3)/sub L/(-)U(1)/sub N/ electroweak model in e/sup +/e/sup -/ colliders (Next Linear Collider and CERN Linear Collider). We also analyze the indirect evidence for a boson Z'. (23 refs).
From SU(3) to gravity: Festschrift in honor of Yuval Ne'eman
International Nuclear Information System (INIS)
This book contains papers covering the following topics: groups and gauges, particles, science policy, astronomy and astrophysics, and gravity and supergravity. Some of the titles of the papers include: General covariance and the passive equations of physics, Symmetry of wave functions for ''like'' unstable particles, Analytical calculations for masses in Hamiltonian lattice theories, on plane waves and nullicles, Descrete Yang-Milles theories, Refugee scientists and nuclear energy, QCD inequalities, Speculation in cosmology, and an alternative to general relativity
Scaling in SU(3) theory with a MCRG improved lattice action
Borici, A.; Rosenfelder, R.
1997-01-01
We test various improved gauge actions which are made of linear combinations of Wilson loops. We observe the restoration of rotational symmetry in the static interquark potential already on coarse lattices as small as 6^3x12. Furthermore, we study scaling and asymptotic scaling of the string tension with a MCRG-improved action on 12^3x24 lattices. Preliminary results show that scaling sets in at a ~ 0.3 fm.
Charmed Mesons in Nuclei with Heavy-Quark Spin Symmetry
Tolos, L.; Garcia-Recio, C.; Nieves, J.; Romanets, O.; Salcedo, L. L.
2013-08-01
We study the properties of charmed pseudoscalar and vector mesons in dense matter within a unitary meson-baryon coupled-channel model which incorporates heavy-quark spin symmetry. This is accomplished by extending the SU(3) Weinberg-Tomozawa Lagrangian to incorporate spin-flavor symmetry and implement a suitable flavor symmetry breaking. Several resonances with negative parity are generated dynamically by the s-wave interaction between pseudoscalar and vector meson multiplets with 1/2+ and 3/2+ baryons. Those states are then compared to experimental data as well as theoretical models. Next, Pauli-blocking effects and meson self-energies are introduced in a self-consistent manner to obtain the open-charm meson spectral functions in a dense nuclear environment. We finally discuss the formation of D-mesic nuclei.
Charmed mesons in nuclei with heavy-quark spin symmetry
Tolos, L; Nieves, J; Romanets, O; Salcedo, L L
2012-01-01
We study the properties of charmed pseudoscalar and vector mesons in dense matter within a unitary meson-baryon coupled-channel model which incorporates heavy-quark spin symmetry. This is accomplished by extending the SU(3) Weinberg-Tomozawa Lagrangian to SU(8) spin-flavor symmetry and implementing a suitable flavor symmetry breaking. Several resonances with negative parity are generated dynamically by the s-wave interaction between pseudoscalar and vector meson multiplets with $1/2^+$ and $3/2^+$ baryons. Those states are then compared to experimental data as well as theoretical models. Next, Pauli-blocking effects and meson self-energies are introduced in a self-consistent manner to obtain the open-charm meson spectral functions in a dense nuclear environment. We finally discuss the formation of $D$-mesic nuclei.
Conserved quantities and symmetries related to stochastic Hamiltonian systems
Institute of Scientific and Technical Information of China (English)
Shang Mei; Mei Feng-Xiang
2007-01-01
In this paper symmetries and conservation laws for stochastic dynamical systems are discussed in detail.Determining equations for infinitesimal approximate symmetries of Ito and Stratonovich dynamical systems are derived. It shows how to derive conserved quantities for stochastic dynamical systems by using their symmetries without recourse to Noether's theorem.
Jaffé, Hans H
1977-01-01
This book, devoted exclusively to symmetry in chemistry and developed in an essentially nonmathematical way, is a must for students and researchers. Topics include symmetry elements and operations, multiple symmetry operations, multiplication tables and point groups, group theory applications, and crystal symmetry. Extensive appendices provide useful tables.
CERN. Geneva
2015-01-01
Most physics results at the LHC end in a likelihood ratio test. This includes discovery and exclusion for searches as well as mass, cross-section, and coupling measurements. The use of Machine Learning (multivariate) algorithms in HEP is mainly restricted to searches, which can be reduced to classification between two fixed distributions: signal vs. background. I will show how we can extend the use of ML classifiers to distributions parameterized by physical quantities like masses and couplings as well as nuisance parameters associated to systematic uncertainties. This allows for one to approximate the likelihood ratio while still using a high dimensional feature vector for the data. Both the MEM and ABC approaches mentioned above aim to provide inference on model parameters (like cross-sections, masses, couplings, etc.). ABC is fundamentally tied Bayesian inference and focuses on the “likelihood free” setting where only a simulator is available and one cannot directly compute the likelihood for the dat...
Schmidt, Wolfgang M
1980-01-01
"In 1970, at the U. of Colorado, the author delivered a course of lectures on his famous generalization, then just established, relating to Roth's theorem on rational approxi- mations to algebraic numbers. The present volume is an ex- panded and up-dated version of the original mimeographed notes on the course. As an introduction to the author's own remarkable achievements relating to the Thue-Siegel-Roth theory, the text can hardly be bettered and the tract can already be regarded as a classic in its field."(Bull.LMS) "Schmidt's work on approximations by algebraic numbers belongs to the deepest and most satisfactory parts of number theory. These notes give the best accessible way to learn the subject. ... this book is highly recommended." (Mededelingen van het Wiskundig Genootschap)
Rotational-isotopic symmetries
International Nuclear Information System (INIS)
In this note we submit a nonlocal (integral) generalization of the rotational-isotopic symmetries O-circumflex(3) introduced in preceding works for nonlinear and nonhamiltonian systems in local approximation. By recalling that the Lie-isotopic theory naturally admits nonlocal terms when all embedded in the isounit, while the conventional symplectic geometry is strictly local-differential, we introduce the notion of symplectic-isotopic two-forms, which are exact symplectic two-forms admitting a factorization into the Kronecker product of a canonical two-form time the isotopic element of an underlying Euclidean-isotopic space. Topological consistency is then achieved by embedding all nonlocal terms in the isounit of the iso-cotangent bundle, while keeping the local topology for the canonical part. In this way, we identify the symplectic-isotopic geometry as being the natural geometrical counterpart of the Lie-isotopic theory. The results are used for the introduction of the notion of Birkhoffian angular momentum, that is, the generalization of the conventional canonical angular momentum which is applicable to Birkhoffian systems with generally nonlinear, nonlocal and nonhamiltonian internal forces. The generators J (and the parameters θ) coincide with the conventional quantities. Nevertheless, the quantity J is defined on the underlying Euclidean-isotopic space, by therefore acquiring a generalized magnitude. The isocommutation rules and isoexponentiation of the Birkhoffian angular momentum are explicitly computed and shown to characterize the most general known nonlinear and nonlocal realization of the isorotational symmetry. The local isomorphisms between the infinitely possible isotopes O-circumflex(3) and the conventional symmetry O(3) is proved. Finally the isosymmetries O-circumflex(3) are used to characterize the conserved, total, Birkhoffian angular momentum of closed nonselfadjoint systems. (author). 4 refs
The LHC diphoton resonance from gauge symmetry
Boucenna, Sofiane M; Vicente, Avelino
2015-01-01
Motivated by what is possibly the first sign of new physics seen at the LHC, the diphoton excess at 750 GeV in ATLAS and CMS, we present a model that provides naturally the necessary ingredients to explain the resonance. The simplest phenomenological explanation for the diphoton excess requires a new scalar state, X(750), as well as additional vector-like (VL) fermions introduced in an ad-hoc way in order to enhance its decays into a pair of photons and/or increase its production cross-section. We show that the new scalar particle, as well as the necessary VL quarks to produce it and generate the diphoton signal can be naturally embedded in a complete framework based on the SU(3)_L gauge symmetry.
Applications of chiral symmetry
International Nuclear Information System (INIS)
The author discusses several topics in the applications of chiral symmetry at nonzero temperature. First, where does the rho go? The answer: up. The restoration of chiral symmetry at a temperature Tχ implies that the ρ and a1 vector mesons are degenerate in mass. In a gauged linear sigma model the ρ mass increases with temperature, mρ(Tχ) > mρ(0). The author conjectures that at Tχ the thermal ρ - a1, peak is relatively high, at about ∼1 GeV, with a width approximately that at zero temperature (up to standard kinematic factors). The ω meson also increases in mass, nearly degenerate with the ρ, but its width grows dramatically with temperature, increasing to at least ∼100 MeV by Tχ. The author also stresses how utterly remarkable the principle of vector meson dominance is, when viewed from the modern perspective of the renormalization group. Secondly, he discusses the possible appearance of disoriented chiral condensates from open-quotes quenchedclose quotes heavy ion collisions. It appears difficult to obtain large domains of disoriented chiral condensates in the standard two flavor model. This leads to the last topic, which is the phase diagram for QCD with three flavors, and its proximity to the chiral critical point. QCD may be very near this chiral critical point, and one might thereby generated large domains of disoriented chiral condensates
Miller, G A
2003-01-01
Two new experiments have detected charge-symmetry breaking, the mechanism responsible for protons and neutrons having different masses. Symmetry is a crucial concept in the theories that describe the subatomic world because it has an intimate connection with the laws of conservation. The theory of the strong interaction between quarks - quantum chromodynamics - is approximately invariant under what is called charge symmetry. In other words, if we swap an up quark for a down quark, then the strong interaction will look almost the same. This symmetry is related to the concept of sup i sospin sup , and is not the same as charge conjugation (in which a particle is replaced by its antiparticle). Charge symmetry is broken by the competition between two different effects. The first is the small difference in mass between up and down quarks, which is about 200 times less than the mass of the proton. The second is their different electric charges. The up quark has a charge of +2/3 in units of the proton charge, while ...
International Nuclear Information System (INIS)
Highlights: • Development of optimization rules for S2 quadrature sets. • Studying the dependency of optimized S2 quadratures on composition and geometry. • Demonstrating S2 procedures preserving the features of higher approximations. - Abstract: Discrete ordinates method relies on approximating the integral term of the transport equation with the aid of quadrature summation rules. These quadratures are usually based on certain assumptions which assure specific symmetry rules and transport/diffusion limits. Generally, these assumptions are not problem-dependent which results in inaccuracies in some instances. Here, various methods have been developed for more accurate estimation of the independent angle in S2 approximation, as it is tightly related to valid estimation of the diffusion coefficient/length. We proposed and examined a method to reduce a complicated problem that usually is consisting many energy groups and discrete directions (SN) to an equivalent one-group S2 problem while it mostly preserves general features of the original model. Some numerical results are demonstrated to show the accuracy of proposed method
Unified framework for symmetry breaking in SO(10)
International Nuclear Information System (INIS)
A new SO(10) unified model is proposed based on a one-step breaking of SO(10) to the standard model gauge group SU(3)CxSU(2)LxU(1)Y using a single 144 of Higgs. The symmetry breaking occurs when the SU(5) 24-plet component of 144 develops a vacuum expectation value. Further, it is possible to obtain from the same 144 a light Higgs doublet necessary for electroweak symmetry breaking using recent ideas of string vacua landscapes and fine-tuning. Thus the breaking of SO(10) down to SU(3)CxU(1)em can be accomplished with a single Higgs. We analyze this symmetry breaking pattern in the nonsupersymmetric as well as in the supersymmetric SO(10) model. In this scenario masses of the quarks and leptons arise via quartic couplings. We show that the resulting mass pattern is consistent with experimental data, including neutrino oscillations. The model represents an alternative to the currently popular grand unified scenarios
Shibata, Akihiro; Kato, Seikou; Shinohara, Toru
2014-01-01
The dual superconductivity is a promising mechanism for quark confinement. We proposed the non-Abelian dual superconductivity picture for SU(3) Yang-Mills theory, and demonstrated the restricted field dominance (called conventionally "Abelian" dominance), and non-Abelian magnetic monopole dominance in the string tension. In the last conference, we have demonstrated by measuring the chromoelectric flux that the non-Abelian dual Meissner effect exists and determined that the dual superconductivity for SU(3) case is of type I, which is in sharp contrast to the SU(2) case: the border of type I and type II. In this talk, we focus on the confinement/deconfinemen phase transition and the non-Abelian dual superconductivity at finite temperature: We measure the chromoelectric flux between a pair of static quark and antiquark at finite temperature, and investigate its relevance to the phase transition and the non-Abelian dual Meissner effect.
Indian Academy of Sciences (India)
Siddhartha Sen
2002-08-01
A classical phase space with a suitable symplectic structure is constructed together with functions which have Poisson brackets algebraically identical to the Lie algebra structure of the Lie group SU(3). It is shown that in this phase space there are two spheres which intersect at one point. Such a system has a representation as an algebraic curve of the form $X^{3} +\\cdots = 0$ in $\\mathscr{C}^{3}$. The curve introduced is singular at the origin in the limit when the radii of the spheres go to zero. A direct connection between the Lie groups SU(3) and a singular curve in $\\mathscr{C}^{3}$ is thus established. The key step needed to do this was to treat the Lie group as a quantum system and determine its phase space.
Pushing the pseudo-SU(3) model towards its limits: Excited bands in even-even Dy isotopes
International Nuclear Information System (INIS)
The energetics of states belonging to normal parity bands in even-even dysprosium isotopes, and their B(E2) transition strengths, are studied using an extended pseudo-SU(3) shell model. States with pseudospin 1 are added to the standard pseudospin 0 space, allowing for a proper description of known excited normal parity bands. A realistic Hamiltonian is employed. Both the success of model and its limitations are discussed
Müller, Sarah; Schacht, Stefan
2015-01-01
We study decays of $D^0$, $D^+$, and $D_s^+$ mesons into two pseudoscalar mesons by expressing the decay amplitudes in terms of topological amplitudes. Including consistently SU(3)$_F$ breaking to linear order, we show how the topological-amplitude decomposition can be mapped onto the standard expansion using reduced amplitudes characterized by SU(3) representations. The tree and annihilation amplitudes can be calculated in factorization up to corrections which are quadratic in the color-counting parameter $1/N_c$. We find new sum rules connecting $D^+\\rightarrow K_SK^+$, $D_s^+\\rightarrow K_S\\pi^+$ and $D^+\\rightarrow K^+\\pi^0$, which test the quality of the $1/N_c$ expansion. Subsequently, we determine the topological amplitudes in a global fit to the data, taking the statistical correlations among the various measurements into account. We carry out likelihood ratio tests in order to quantify the role of specific topological contributions. While the SU(3)$_F$ limit is excluded with a significance of more th...
Low-Lying Pentaquark Baryons in Pseudoscalar-Vector SU(3) Skyrme Model
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
For the first time the low-lying J = 1/2 pentaquark states are investigated in the pseudoscalar-vector Skyrme model. Once the conventional baryon properties are fit, other states are predicted without any more adjustable parameters. Furthermore, both symmetry-breaking and decay operators are treated in full. In particular, we focus on the calculations of mass and decay width, and compare them with the experimental data available and relevant theoretical results obtained in other pictures. We recognize that the higher-order contributions, such as the 35 and/or (-35) representation admixtures, are not negligible. Our analysis provides some valuable clues to the physical mechanisms, and the oncoming experimental search and/or confirmation could provide a sharp test of our proposal.
Dynamical generation of a composite quark-lepton symmetry
International Nuclear Information System (INIS)
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)
CHIRAL SYMMETRIES IN NUCLEAR PHYSICS
International Nuclear Information System (INIS)
The theoretical concepts of a chirally symmetric meson field theory are reviewed and an overview of the most relevant applications in nuclear physics is given. This includes a unified description of the vacuum properties of hadrons, finite nuclei and hot, dense and strange nuclear matter in an extended chiral SU(3)L/SU(3)R σ-ω model
On the hidden U(3) symmetry of an electron
International Nuclear Information System (INIS)
It is shown that the Zitterbewegung and the internal degrees of freedom of the relativistic particle are associated with Lie algebra of the SO(5) group. The SO(5) algebra is the dynamical algebra of electron. It is as well found that the electron Hamiltonian is invariant under the U(3) transformation, i.e. Dirac's theory contains the hidden U(3) symmetry caused by the Zittenbewegung and by the existence of the dynamical algebra. Four triplets are pointed out which satisfy the Dirac equation and form basises of the fundamental representations of the SU(3) group
On the hidden U(3) symmetry of the electron
International Nuclear Information System (INIS)
It is shown that the Zitterbewegung and internal degrees of freedom of a relativistic particle are related to the Lie algebra of SO(5). The SO(5) algebra is the dynamical algebra of the electron. It is also shown that the electron Hamiltonian is invariant under transformations of the group U(3), that is, the Dirac theory contains a hidden U(3) symmetry due to the Zitterbewegung and the existence of a dynamical algebra. We find four triplets which satisfy the Dirac equation and form the basis of the fundamental representations of the group SU(3)
Colour-symmetry-breaking effects in hard processes
International Nuclear Information System (INIS)
A possibility of colour symmetry U(1)xSU(3)sub(C) spontaneous breaking and integer-charged quarks is considered. It is argued that one-photon processes are sensitive only to the colour-averaged charges of quarks and gluons. The true charges can be observed in rigid processes involving at least two real photons. The available now experimental data on processes #betta#p → #betta#X, #betta##betta# → jet+jet are in better agreement with the integer-charges than with the standard QCD
Local Conformal Symmetry: the Missing Symmetry Component for Space and Time
Hooft, Gerard T
2014-01-01
Local conformal symmetry is usually considered to be an approximate symmetry of nature, which is explicitly and badly broken. Arguments are brought forward here why it has to be turned into an exact symmetry that is spontaneously broken. As in the B.E.H. mechanism in Yang-Mills theories, we then will have a mechanism for disclosing the small-distance structure of the gravitational force. The symmetry could be as fundamental as Lorentz invariance, and guide us towards a complete understanding of physics at the ultra short distance scale.
Discrete Symmetries/Discrete Theories
Bose, Milton; Dine, Michael
2012-01-01
Dynamical, metastable supersymmetry breaking appears to be a generic phenomena in supersymmetric field theories. It's simplest implementation is within the so-called "retrofitted O'Raifeartaigh Models". While seemingly flexible, model building in these theories is significantly constrained. In gauge-mediated versions, if the approximate $R$ symmetry of the theory is spontaneously broken, the messenger scale is fixed; if explicitly broken by retrofitted couplings, a very small dimensionless nu...
Miyatsu, Tsuyoshi; Saito, Koichi
2015-01-01
We construct the equation of state (EoS) for neutron stars explicitly including hyperons and quarks. Using the quark-meson coupling model with relativistic Hartree-Fock approximation, the EoS for hadronic matter is derived by taking into account the strange ($\\sigma^{\\ast}$ and $\\phi$) mesons as well as the light non-strange ($\\sigma$, $\\omega$, $\\vec{\\pi}$ and $\\vec{\\rho}$) mesons. Relevant coupling constants are determined to reproduce the experimental data of nuclear matter and hypernuclei in SU(3) flavor symmetry. For quark matter, we employ the MIT bag model with one-gluon-exchange interaction, and Gibbs criteria for chemical equilibrium in the phase transition from hadrons to quarks. We find that the strange vector ($\\phi$) meson and the Fock contribution make the hadronic EoS stiff, and that the maximum mass of a neutron star can be consistent with the observed mass of heavy neutron stars even if the coexistence of hadrons and quarks takes place in the core. However, in the present calculation the tran...
Towards mirror symmetry a la SYZ for generalized Calabi-Yau manifolds
International Nuclear Information System (INIS)
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.)
Buccella, F.; Cocco, L.; Sciarrino, A.; Tuzi, T.
1986-09-01
We construct a unified model with symmetry breaking pattern SO(10) → SO(6) × SO(4) → SU(3) × SU(2) × U(1) → SU3 ×U(1) with Higgs in the 210 + 126 + 10 representations, which is consistent with the lower bound on τp → e + + π0 and with the experimental values of sin 2ϑ w and α s. It is not difficult to adjust the parameters in the scalar potential in such a way as to expect mντ ≈ 10 eV, while drastic conditions are required to expect τ N overlineN
Nilles, H. P.; Ratz, M.; Vaudrevange, P. K. S.
2012-01-01
Discrete (family) symmetries might play an important role in models of elementary particle physics. We discuss the origin of such symmetries in the framework of consistent ultraviolet completions of the standard model in field and string theory. The symmetries can arise due to special geometrical properties of extra compact dimensions and the localization of fields in this geometrical landscape. We also comment on anomaly constraints for discrete symmetries.
Energy Technology Data Exchange (ETDEWEB)
Nilles, Hans Peter [Bonn Univ. (Germany). Bethe Center for Theoretical Physics; Bonn Univ. (Germany). Physikalisches Inst.; Ratz, Michael [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Vaudrevange, Patrick K.S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2012-04-15
Discrete (family) symmetries might play an important role in models of elementary particle physics. We discuss the origin of such symmetries in the framework of consistent ultraviolet completions of the standard model in field and string theory. The symmetries can arise due to special geometrical properties of extra compact dimensions and the localization of fields in this geometrical landscape. We also comment on anomaly constraints for discrete symmetries.
Numerical renormalization group studies of the partially brogen SU(3) Kondo model
Energy Technology Data Exchange (ETDEWEB)
Fuh Chuo, Evaristus
2013-04-15
The two-channel Kondo (2CK) effect with its exotic ground state properties has remained difficult to realize in physical systems. At low energies, a quantum impurity with orbital degree of freedom, like a proton bound in an interstitial lattice space, comprises a 3-level system with a unique ground state and (at least) doubly degenerate rotational excitations with excitation energy {Delta}{sub 0}. When immersed in a metal, electronic angular momentum scattering induces transitions between any two of these levels (couplings J), while the electron spin is conserved. We show by extensive numerical renormalization group (NRG) calculations that without fi ne-tuning of parameters this system exhibits a 2CK fixed point, due to Kondo correlations in the excited-state doublet whose degeneracy is stabilized by the host lattice parity, while the channel symmetry (electron spin) is guaranteed by time reversal symmetry. We find a pronounced plateau in the entropy at S(T{sub K}
Numerical renormalization group studies of the partially brogen SU(3) Kondo model
International Nuclear Information System (INIS)
The two-channel Kondo (2CK) effect with its exotic ground state properties has remained difficult to realize in physical systems. At low energies, a quantum impurity with orbital degree of freedom, like a proton bound in an interstitial lattice space, comprises a 3-level system with a unique ground state and (at least) doubly degenerate rotational excitations with excitation energy Δ0. When immersed in a metal, electronic angular momentum scattering induces transitions between any two of these levels (couplings J), while the electron spin is conserved. We show by extensive numerical renormalization group (NRG) calculations that without fi ne-tuning of parameters this system exhibits a 2CK fixed point, due to Kondo correlations in the excited-state doublet whose degeneracy is stabilized by the host lattice parity, while the channel symmetry (electron spin) is guaranteed by time reversal symmetry. We find a pronounced plateau in the entropy at S(TK0)=kB ln 2 between the high-T value, S(T>>Δ0)=kB ln 3, and the 2CK ground state value, S(0)=kB ln √(2). This indicates a downward renormalization of the doublet below the non-interacting ground state, thus realizing the 2CK fixed point, in agreement with earlier conjectures. We mapped out the phase diagram of the model in the J-Δ0 plane. The Kondo temperature TK shows non-monotonic J-dependence, characteristic for 2CK systems. Beside the two-channel Kondo effect of the model, we also study the single-channel version, which is realized by applying a strong magnetic fi eld to the conduction band electrons so that their degeneracy is lifted and consequently having only one kind of electrons scattering off the impurity. This single-channel case is easier to analyze since the Hilbert space is not as large as that of the 2CK. We equally find a downward renormalization of the excited state energy by the Kondo correlations in the SU(2) doublet. In a wide range of parameter values this stabilizes the single-channel Kondo fixed
The discrete family symmetry as a possible solution to the flavour problem
Dziewit, Bartosz; Richter, Monika; Zając, Sebastian; Zrałek, Marek
2016-01-01
In order to explain the fermions masses and mixing parameters appearing in the lepton sector of the Standard Model, one proposes the extension of its symmetry. A discrete, non-abelian subgroup of $U(3)$ is added to the gauge group $SU(3)_{C}\\times SU(2)_{L}\\times U(1)_{Y}$ . Apart from that, one assumes the existence of one extra Higgs doublet. This article focuses mainly on the mathematical theorems and computational techniques which brought us to the results.
Spontaneous CP violation and non-abelian family symmetry in SUSY
International Nuclear Information System (INIS)
We present a model based on an SU(3) family symmetry providing a full description of quark and lepton masses and mixing angles. CP is spontaneously broken in the flavour sector reproducing the observed results of the Jarlskog invariant in the CKM mixing matrix. Our model predicts the amount of CP violation to be expected in the neutrino sector and solves the Supersymmetric CP and FCNC problems in a gravity mediation scenario. (author)
IBM symmetries in realistic shell model states
International Nuclear Information System (INIS)
An approximate dynamical symmetry referring to IBM-type bosons is shown to be latent in the shell model eigenfunctions for 54Cr and 56Fe. No symmetry is assumed in the approach, which invokes only a realistic shell model interaction and an interpretation of the bosons as nucleon pairs. Particular emphasis is placed on the levels involved in M1 excitation. 25 refs., 4 tabs., 1 fig
Approximate maximizers of intricacy functionals
Buzzi, Jerome
2009-01-01
G. Edelman, O. Sporns, and G. Tononi introduced in theoretical biology the neural complexity of a family of random variables. This functional is a special case of intricacy, i.e., an average of the mutual information of subsystems whose weights have good mathematical properties. Moreover, its maximum value grows at a definite speed with the size of the system. In this work, we compute exactly this speed of growth by building "approximate maximizers" subject to an entropy condition. These approximate maximizers work simultaneously for all intricacies. We also establish some properties of arbitrary approximate maximizers, in particular the existence of a threshold in the size of subsystems of approximate maximizers: most smaller subsystems are almost equidistributed, most larger subsystems determine the full system. The main ideas are a random construction of almost maximizers with a high statistical symmetry and the consideration of entropy profiles, i.e., the average entropies of sub-systems of a given size. ...
Effective lattice Polyakov loop theory vs. full SU(3) Yang-Mills at finite temperature
Energy Technology Data Exchange (ETDEWEB)
Bergner, G. [Institut für Theoretische Physik, Goethe-Universität Frankfurt,Max-von-Laue-Str. 1, 60438 Frankfurt am Main (Germany); Langelage, J. [Institute for Theoretical Physics, ETH Zürich,CH-8093 Zürich (Switzerland); Philipsen, O. [Institut für Theoretische Physik, Goethe-Universität Frankfurt,Max-von-Laue-Str. 1, 60438 Frankfurt am Main (Germany)
2014-03-06
A three-dimensional effective theory of Polyakov loops has recently been derived from Wilson’s Yang-Mills lattice action by means of a strong coupling expansion. It is valid in the confined phase up to the deconfinement phase transition, for which it predicts the correct order and gives quantitative estimates for the critical coupling. In this work we study its predictive power for further observables like correlation functions and the equation of state. We find that the effective theory correctly reproduces qualitative features and symmetries of the full theory as the continuum is approached. Regarding quantitative predictions, we identify two classes of observables by numerical comparison as well as analytic calculations: correlation functions and their associated mass scales cannot be described accurately from a truncated effective theory, due to its inherently non-local nature involving long-range couplings. On the other hand, phase transitions and bulk thermodynamic quantities are accurately reproduced by the leading local part of the effective theory. In particular, the effective theory description is numerically superior when computing the equation of state at low temperatures or the properties of the phase transition.
International Nuclear Information System (INIS)
It is shown that arguments given by Edwards and Kamal, against the explanation of the experimental value GAMMA (rho → πγ) = 35 +- 10 keV by an SU(3) -scalar term in the electromagnetic current operator, are wrong. Sensitive experimental criteria for such an SU(3) -scalar term are listed and it is shown that the very recently obtained experimental value of the branching ratio (eta' → rhoγ)/(eta' → ωγ) = 9.9 +- 2 disfavors the existence of an SU(3) -scalar term large enough to explain the experimental value of GAMMA
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.
Spontaneously broken SU(5) symmetries and 1-loop effects in the early Universe
Buccella, F.; Esposito, G.; Miele, G.
1992-06-01
This paper studies one-loop effective potential and spontaneous-symmetry-breaking pattern for SU(5) gauge theory in de Sitter space-time. Curvature effects modify the flat-space effective potential by means of a very complicated special function previously derived in the literature. An algebraic technique already developed by the first author to study spontaneous symmetry breaking of SU(n) for renormalizable polynomial potentials is here generalized, for SU(5), to the much harder case of a de Sitter background. A detailed algebraic and numerical analysis provides a better derivation of the stability of the extrema in the maximal subgroups SU(4) x U(1), SU(3) x SU(2) x U(1), SU(3) x U(1) x U(1) x R(311), SU(2) x SU(2) x U(1) x U(1) x R(2211), where R(311) and R(2211) discrete symmetries select particular directions in the corresponding two-dimensional strata. One thus obtains a deeper understanding of the result, previously found with a different numerical analysis, predicting the slide of the inflationary universe into either the SU(3) x SU(2) x U(1) or SU(4) x U(1) extremum. Interestingly, using this approach, one can easily generalize all previous results to a more complete SU(5) tree-level potential also containing cubic terms.
Symmetry Analysis of Telegraph Equation
Nadjafikhah, Mehdi; Hejazi, Seyed Reza
2010-01-01
Lie symmetry group method is applied to study the Telegraph equation. The symmetry group and its optimal system are given, and group invariant solutions associated to the symmetries are obtained. Finally the structure of the Lie algebra symmetries is determined.
Symmetries in subatomic systems
International Nuclear Information System (INIS)
The underlying common themes of the EJC-2010 are symmetries and symmetry violation in relation to nucleon structure, nuclear geometry, isospin and reaction dynamics. The parity violation in electron scattering is the unique probe of strange quarks in nucleons and of neutron skin in heavy nuclei. The use of dynamical symmetries or spectrum generating algebras for the solution of the nuclear many-body problem is reviewed. We also discuss the impact of the symmetries of quantum chromodynamics on the observed properties of hadrons and strongly interacting matter. Mean field approaches are widely used to study nuclear structure properties and correlations between nucleons are treated by symmetry-violating mean field approaches and symmetry properties are currently treated with beyond mean field approaches by using projection techniques. A paper focuses on properties of giant resonances (GR) and particularly on the relationship between GR and isospin symmetry. This document gathers the papers and/or slides of 10 presentations. (A.C.)
Three-particle Poincare states and SU(6) x SU(3) as a classification group of baryons
International Nuclear Information System (INIS)
A complete set of democratic quantum numbers is introduced to classify the states of an irreducible unitary representation (IUR) of the Poincare group obtained from the decomposition of the direct product of three IUR. Such states are identified with the baryon states constituted of three free relativistic quarks. The transformation form current to constitutent quarks is then easily reobtained. Moreover, the group SU(6) x SU(3) appears naturally as a collinear classification group for baryons. Results similar to those of the symmetric harmonic oscillator quark model are obtained
Three-particle Poincare states and SU(6) x SU(3) as a classification group of baryons
Energy Technology Data Exchange (ETDEWEB)
Buccella, F.; Sciarrino, A.; Sorba, P.
1976-09-10
A complete set of democratic quantum numbers is introduced to classify the states of an irreducible unitary representation (IUR) of the Poincare group obtained from the decomposition of the direct product of three IUR. Such states are identified with the baryon states constituted of three free relativistic quarks. The transformation form current to constitutent quarks is then easily reobtained. Moreover, the group SU(6) x SU(3) appears naturally as a collinear classification group for baryons. Results similar to those of the symmetric harmonic oscillator quark model are obtained. (AIP)
The role of the Coriolis potential in the pseudo SU(3) description of well deformed odd-A isotopes
International Nuclear Information System (INIS)
The energy spectrum of 179Ta has been predicted using the quadrupole plus the Coriolis interaction in the pseudo SU(3) scheme. The doublet structure of the 1/2+ band members has been generated to fit exactly the experimental situation, a vast improvement over the mispairing obtained with the quadrupole interaction alone as the two-body interaction, obtained in a previous study. The effect of the Coriolis term on the spacings of low-lying rotational levels, especially of the 1/2+ band, was studied at two different strengths. It is shown that the particle-rotation coupling is important at the strongly deformed regions. (author)
Z' boson decay in the SU(3)L \\otimes U(1)N electroweak model with heavy leptons
Abad, David Romero; Ravinez, Orlando Pereyra
2011-01-01
Based on the expectation generated by the discovery of new particles by current colliders, we analyze the decay of the Z' boson in the frame of one of the SU(3)L \\otimes U(1)N electroweak extensions of the standard model. The main objective is calculate the decay rate of this exotic boson in the aforementioned model at the tree level. With this purpose we need to develop the gauge sector, where we find thirty-three interaction terms. Mentioned particle (Z') has not yet been observed experimen...
Chiu, Ting-Wai
2016-01-01
We present the first study of the discrete $\\beta$-function of the $ SU(3) $ gauge theory with 10 massless domain-wall fermions in the fundamental representation. The renormalized coupling is obtained by the finite-volume gradient flow scheme, and the discrete $\\beta$-function is extrapolated to the continuum limit by the step-scaling method. Our result of the discrete $\\beta$-function (with $ s = 2 $) suggests that this theory possesses an infrared fixed point around $ g_c^2 \\sim 7.0 $ for $ c = \\sqrt{8t}/L = 0.3 $.
A search for symmetries in the genetic code
International Nuclear Information System (INIS)
A search for symmetries based on the classification theorem of Cartan for the compact simple Lie algebras is performed to verify to what extent the genetic code is a manifestation of some underlying symmetry. An exact continuous symmetry group cannot be found to reproduce the present, universal code. However a unique approximate symmetry group is compatible with codon assignment for the fundamental amino acids and the termination codon. In order to obtain the actual genetic code, the symmetry must be slightly broken. (author). 27 refs, 3 figs, 6 tabs
Symmetry and symmetry breaking in quantum mechanics
International Nuclear Information System (INIS)
In the world of infinitely small, the world of atoms, nuclei and particles, the quantum mechanics enforces its laws. The discovery of Quanta, this unbelievable castration of the Possible in grains of matter and radiation, in discrete energy levels compels us of thinking the Single to comprehend the Universal. Quantum Numbers, magic Numbers and Numbers sign the wave. The matter is vibration. To describe the music of the world one needs keys, measures, notes, rules and partition: one needs quantum mechanics. The particles reduce themselves not in material points as the scholars of the past centuries thought, but they must be conceived throughout the space, in the accomplishment of shapes of volumes. When Einstein asked himself whether God plays dice, there was no doubt among its contemporaries that if He exists He is a geometer. In a Nature reduced to Geometry, the symmetries assume their role in servicing the Harmony. The symmetries allow ordering the energy levels to make them understandable. They impose there geometrical rules to the matter waves, giving them properties which sometimes astonish us. Hidden symmetries, internal symmetries and newly conceived symmetries have to be adopted subsequently to the observation of some order in this world of Quanta. In turn, the symmetries provide new observables which open new spaces of observation
Introduction to particle physics, symmetries and conservation laws. 10
International Nuclear Information System (INIS)
This chapter gives a description of the phenomenology of particle physics, more or less in a historical sequence. The various inter-actions, their strengths and symmetries, associated selection rules, and details of the particle spectrum are discussed, with frequent presentation of orders of magnitude of physical quantities. Isotopic spin, strangeness, baryon and lepton numbers, and the discrete symmetries C. P, T and their combinations are explained. The presentation includes γ5 invariance of the V-A form of weak interactions; the quark-gluon picture for strong interactions based on SU(3)c; and the gauge principle for electrodynamics and for non-Abelian theory. The Glashow-Weinberg-Salam model is briefly sketched. (author). 2 refs.; 1 fig.; 2 tabs
Unified dark matter with intermediate symmetry breaking scales
Lonsdale, Stephen J.
2015-06-01
Asymmetric symmetry breaking models dynamically break the G ×G gauge symmetries of mirror models to distinct subgroups in the two sectors. The coincidental abundances of visible and dark matter, ΩDM≃5 ΩVM , motivates asymmetric dark matter theories where similar number densities of baryons in each sector are explained by their connected origins. However, the question of why the baryons of two sectors should have similar mass remains. In this work we develop an alternative class of asymmetric symmetry breaking models which unify the dark and visible sectors while generating a small difference in the mass scale of the baryons of each sector. By examining the different paths that the SO(10) GUT group can take in breaking to gauge symmetries containing SU(3), we can adapt the mechanism of asymmetric symmetry breaking to demonstrate models in which originally unified visible and dark sectors have isomorphic color gauge groups at low energy yet pass through different intermediate gauge groups at high energy. Through this, slight differences in the running coupling evolutions and, thus, the confinement scales of the two sectors are generated.
Unified dark matter with intermediate symmetry breaking scales
Lonsdale, Stephen J
2014-01-01
Asymmetric symmetry breaking models dynamically break the G X G gauge symmetries of mirror models to distinct subgroups in the two sectors. The coincidental abundances of visible and dark matter, $\\Omega_{DM} \\simeq 5\\Omega_{VM}$, motivates asymmetric dark matter theories where similar number densities of baryons in each sector are explained by their connected origins. However the question of why the baryons of two sectors should have similar mass remains. In this work we develop an alternative class of asymmetric symmetry breaking models which unify the dark and visible sectors while generating a small difference in the mass scale of the baryons of each sector. By examining the different paths that the SO(10) GUT group can take in breaking to gauge symmetries containing SU(3) we can adapt the mechanism of asymmetric symmetry breaking to demonstrate models in which originally unified visible and dark sectors have isomorphic color gauge groups at low energy yet pass through different intermediate gauge groups ...
Symmetry-guided large-scale shell-model theory
Launey, Kristina D.; Dytrych, Tomas; Draayer, Jerry P.
2016-07-01
In this review, we present a symmetry-guided strategy that utilizes exact as well as partial symmetries for enabling a deeper understanding of and advancing ab initio studies for determining the microscopic structure of atomic nuclei. These symmetries expose physically relevant degrees of freedom that, for large-scale calculations with QCD-inspired interactions, allow the model space size to be reduced through a very structured selection of the basis states to physically relevant subspaces. This can guide explorations of simple patterns in nuclei and how they emerge from first principles, as well as extensions of the theory beyond current limitations toward heavier nuclei and larger model spaces. This is illustrated for the ab initio symmetry-adapted no-core shell model (SA-NCSM) and two significant underlying symmetries, the symplectic Sp(3 , R) group and its deformation-related SU(3) subgroup. We review the broad scope of nuclei, where these symmetries have been found to play a key role-from the light p-shell systems, such as 6Li, 8B, 8Be, 12C, and 16O, and sd-shell nuclei exemplified by 20Ne, based on first-principle explorations; through the Hoyle state in 12C and enhanced collectivity in intermediate-mass nuclei, within a no-core shell-model perspective; up to strongly deformed species of the rare-earth and actinide regions, as investigated in earlier studies. A complementary picture, driven by symmetries dual to Sp(3 , R) , is also discussed. We briefly review symmetry-guided techniques that prove useful in various nuclear-theory models, such as Elliott model, ab initio SA-NCSM, symplectic model, pseudo- SU(3) and pseudo-symplectic models, ab initio hyperspherical harmonics method, ab initio lattice effective field theory, exact pairing-plus-shell model approaches, and cluster models, including the resonating-group method. Important implications of these approaches that have deepened our understanding of emergent phenomena in nuclei, such as enhanced
Effective meson lagrangian with chiral and heavy quark symmetries from quark flavor dynamics
International Nuclear Information System (INIS)
By bosonization of an extended NJL model we derive an effective meson theory which describes the interplay between chiral symmetry and heavy quark dynamics. This effective theory is worked out in the low-energy regime using the gradient expansion. The resulting effective lagrangian describes strong and weak interactions of heavy B and D mesons with pseudoscalar Goldstone bosons and light vector and axial-vector mesons. Heavy meson weak decay constants, coupling constants and the Isgur-Wise function are predicted in terms of the model parameters partially fixed from the light quark sector. Explicit SU(3)F symmetry breaking effects are estimated and, if possible, confronted with experiment. ((orig.))
Implications of an arithmetical symmetry of the commutant for modular invariants
International Nuclear Information System (INIS)
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.)
Mixed-Symmetry Shell-Model Calculations in Nuclear Physics
Gueorguiev, V G
2010-01-01
We consider a novel approach to the nuclear shell model. The one-dimensional harmonic oscillator in a box is used to introduce the concept of an oblique-basis shell-model theory. By implementing the Lanczos method for diagonalization of large matrices, and the Cholesky algorithm for solving generalized eigenvalue problems, the method is applied to nuclei. The mixed-symmetry basis combines traditional spherical shell-model states with SU(3) collective configurations. We test the validity of this mixed-symmetry scheme on 24Mg and 44Ti. Results for 24Mg, obtained using the Wilthental USD intersection in a space that spans less than 10% of the full-space, reproduce the binding energy within 2% as well as an accurate reproduction of the low-energy spectrum and the structure of the states - 90% overlap with the exact eigenstates. In contrast, for an m-scheme calculation, one needs about 60% of the full space to obtain compatible results. Calculations for 44Ti support the mixed-mode scheme although the pure SU(3) ca...
International Nuclear Information System (INIS)
Symmetry, disymmetry, chirality etc. are well-known topics in chemistry. But they cannot only be found on the molecular level of matter. Atoms and elementary particles in physics are also characterized by particular symmetry groups. Even living organisms and populations on the macroscopic level have functional properties of symmetry. The whole physical, chemical, and biological evolution seems to be regulated by the emergence of new symmetries and the breaking down of old ones. One is reminded of Heisenberg's famous statement: 'Die letzte Wurzel der Erscheinungen ist also nicht die Materie, sondern das mathematische Gesetz, die Symmetrie, die mathematische Form' (Wandlungen in den Grundlagen der Naturwissenschaften, 1959). Historically the belief in symmetry and simplicity of nature has a long philosophical tradition from the Pythagoreans, Plato and Greek astronomers to Kepler and modern scientists. Today, 'symmetries in nature' is a common topic of mathematics, physics, chemistry, and biology. A lot of Nobel prizes were given in honour of inquiries concerning symmetries in nature. The fascination of symmetries is not only motivated by science, but by art and religion too. Therefore 'symmetris in nature' is an interdisciplinary topic which may help to overcome C.P. Snow's 'Two Cultures' of natural sciences and humanities. (author) 17 refs., 21 figs
Alternative formulation for the operator algebra over the space of paths in a ADE $SU(3)$ graph
Pineda, Jesús A; Caicedo, Mario I
2015-01-01
In this work we discuss the elements required for the construction of the operator algebra for the space of paths over a simply laced $SU(3)$ graph. These operators are an important step in the construction of the bialgebra required to find the partition functions of some modular invariant CFTs. We define the cup and cap operators associated with back-and-forth sequences and add them to the creation and annihilation operators in the operator algebra as they are required for the calculation of the full space of essential paths prescribed by the fusion algebra. These operators require collapsed triangular cells that had not been found in previous works; here we provide explicit values for these cells and show their importance in order for the cell system to fulfill the Kuperberg relations for $SU(3)$ tangles. We also find that demanding that our operators satisfy the Temperley-Lieb algebra leads one naturally to consider operators that create and annihilate closed triangular sequences, which in turn provides an...
Huang, C; Zhou, B H
2016-01-01
This paper gives general intrinsic theory of general large $N_{c}$ QCD, SU(3) QCD, SU(2) hadron-dynamics and U(1) QED gauge field theories in general field theory and progress towards solving the nucleon spin crisis, i.e., presents general large $N_{c}$ QCD's inner structures, gauge invariant angular momenta and new corresponding Coulomb theorem in quark-gluon field interaction systems based on general field theory, and naturally deduces the gauge invariant spin and orbital angular momentum operators of quark and gauge fields with $SU(N_{c})$ gauge symmetry by Noether theorem in general field theory. In the general large $N_{c}$ QCD, we discover not only the general covariant transverse and parallel conditions ( namely, non-Abelian divergence and curl ), but also that this general system has good intrinsic symmetry characteristics. Specially, this paper's generally decomposing gauge potential theory presents a new technique, it should play a votal role in future physics research. Therefore, this paper breakth...
Unified theory for external and internal attributes and symmetries of fundamental fermions
Energy Technology Data Exchange (ETDEWEB)
Sogami, Ikuo S, E-mail: sogami@cc.kyoto-su.ac.jp [Maskawa Institute for Science and Culture, Kyoto Sangyo University, Kita-Ku, Kyoto 603-8555 (Japan)
2011-03-01
An unorthodox unified theory is developed to describe external and internal attributes and symmetries of fundamental fermions, quarks and leptons. Basic ingredients of the theory are an algebra which consists of all the triple-direct-products of Dirac {gamma}-matrices and a triple-spinor-field, called a triplet field, defined on the algebra. The algebra possesses three commutative subalgebras which describe, respectively, the external spacetime symmetry, the family structure and the internal color symmetry of quarks and leptons. The triplet field includes threefold (fourfold) repetitional modes of spin 1/2 component fields with SU(3) (SU(4)) color symmetry. It is possible to qualify the Yukawa interaction and to make a new interpretation of its coupling constants naturally in an intrinsic mechanism of the triplet field formalism. The Dirac mass matrices with quasi-democratic structure are derived as an illustration.
From physical symmetries to emergent gauge symmetries
Barceló, Carlos; Di Filippo, Francesco; Garay, Luis J
2016-01-01
Gauge symmetries indicate redundancies in the description of the relevant degrees of freedom of a given field theory and restrict the nature of observable quantities. One of the problems faced by emergent theories of relativistic fields is to understand how gauge symmetries can show up in systems that contain no trace of these symmetries at a more fundamental level. In this paper we start a systematic study aimed to establish a satisfactory mathematical and physical picture of this issue, dealing first with abelian field theories. We discuss how the trivialization, due to the decoupling and lack of excitation of some degrees of freedom, of the Noether currents associated with physical symmetries leads to emergent gauge symmetries in specific situations. An example of a relativistic field theory of a vector field is worked out in detail in order to make explicit how this mechanism works and to clarify the physics behind it. The interplay of these ideas with well-known results of importance to the emergent grav...
Symmetry-improved CJT effective action
International Nuclear Information System (INIS)
The formalism introduced by Cornwall, Jackiw and Tomboulis (CJT) provides a systematic approach to consistently resumming non-perturbative effects in Quantum Thermal Field Theory. One major limitation of the CJT effective action is that its loopwise expansion introduces residual violations of possible global symmetries, thus giving rise to massive Goldstone bosons in the spontaneously broken phase of the theory. In this paper we develop a novel symmetry-improved CJT formalism for consistently encoding global symmetries in a loopwise expansion. In our formalism, the extremal solutions of the fields and propagators to a loopwise truncated CJT effective action are subject to additional constraints given by the Ward Identities due to global symmetries. By considering a simple O(2) scalar model, we show that, unlike other methods, our approach satisfies a number of important field-theoretic properties. In particular, we find that the Goldstone boson resulting from spontaneous symmetry breaking of O(2) is massless and the phase transition is a second-order one, already in the Hartree–Fock approximation. After taking the sunset diagrams into account, we show how our approach properly describes the threshold properties of the massless Goldstone boson and the Higgs particle in the loops. Finally, assuming minimal modifications to the Hartree–Fock approximated CJT effective action, we calculate the corresponding symmetry-improved CJT effective potential and discuss the conditions for its uniqueness for scalar-field values away from its minimum
van der Schaft, A. J.
1987-01-01
It is argued that the existence of symmetries may simplify, as in classical mechanics, the solution of optimal control problems. A procedure for obtaining symmetries for the optimal Hamiltonian resulting from the Maximum Principle is given; this avoids the actual calculation of the optimal Hamiltonian. This procedure is based upon the notion of symmetry for the Hamiltonian system with inputs and outputs associated with an optimal control problem.
Gray, J E; Vogt, A
1997-01-01
Is symmetry informative? The answer is both yes and no. We examine what information and symmetry are and how they are related. Our approach is primarily mathematical, not because mathematics provides the final word, but because it provides an insightful and relatively precise starting point. Information theory treats transformations that messages undergo from source to destination. Symmetries are information that leave some property of interest unchanged. In this respect the studies of information and symmetry can both be regarded as a Quest for the identity transformation. PMID:9224554
Chiral Symmetry Restoration from a Boundary
Tiburzi, B C
2013-01-01
The boundary of a manifold can alter the phase of a theory in the bulk. We explore the possibility of a boundary-induced phase transition for the chiral symmetry of QCD. In particular, we investigate the consequences of imposing homogeneous Dirichlet boundary conditions on the quark fields. Such boundary conditions are employed on occasion in lattice gauge theory computations, for example, when including external electromagnetic fields, or when computing quark propagators with a reduced temporal extent. Homogeneous Dirichlet boundary conditions force the chiral condensate to vanish at the boundary, and thereby obstruct the spontaneous breaking of chiral symmetry in the bulk. As the restoration of chiral symmetry due to a boundary is a non-perturbative phenomenon, we utilize the sigma model to exemplify the issues. Using this model, we find that chiral symmetry is completely restored if the length of the compact direction is less than 2.0 fm. For lengths greater than about 4 fm, an approximately uniform chiral...
Gauss law and symmetry restoration
International Nuclear Information System (INIS)
The authors study the restoration of global symmetries of lattice QCD at finite temperature and chemical potential for an arbitrary number of colors Nc and flavors Nf. The Hamiltonian in the Ao gauge has to be supplemented by the Gauss law constraint, that thermal excitations must satisfy. The authors study the problem in the strong-coupling limit and in a Bogoliubov approximation. The free energy to be minimized must be defined by traces over states restricted in the color singlet Hilbert space at each lattice site
Hidden symmetry in quantum nanostructures
International Nuclear Information System (INIS)
Full text: (author)The theoretical investigation of the hidden symmetries influence on the optical properties of the quantum nanostructures is presented. The problems connected with the parabolic approximation of the confinement potential of the system, as well as two-dimensional Coulomb problem on the character of optical transitions in semiconductor nanostructures are discussed. In particular excitonic absorption in quantum filma and character of arrangement of absorption peak depending on the principal quantum number of the two-dimensional Coulombic problem is also discussed
Roberge-Weiss phase transitions and extended Z3 symmetry
Kouno, H.; Sakai, Y.; Kashiwa, K; Matsuzaki, M.; Yahiro, M.
2008-01-01
Using the Polyakov extended Nambu-Jona-Lasinio (PNJL) model with imaginary chemical potential, the relation between the Roberge-Weiss (RW) phase transition and the extended Z3 symmetry is studied. At low temperature, there is approximate continuous symmetry under the phase transformation of the Polyakov loop with the shift of the imaginary chemical potential. Due to this continuous symmetry, the Polyakov loop can oscillate smoothly as the imaginary chemical potential increases. At high temper...
Lorentz symmetry breaking effects on relativistic EPR correlations
Energy Technology Data Exchange (ETDEWEB)
Belich, H. [Universidade Federal do Espirito Santo, Departamento de Fisica e Quimica, Vitoria, ES (Brazil); Furtado, C.; Bakke, K. [Universidade Federal da Paraiba, Departamento de Fisica, Caixa Postal 5008, Joao Pessoa, PB (Brazil)
2015-09-15
Lorentz symmetry breaking effects on relativistic EPR (Einstein-Podolsky-Rosen) correlations are discussed. From the modified Maxwell theory coupled to gravity, we establish a possible scenario of the Lorentz symmetry violation and write an effective metric for the Minkowski spacetime. Then we obtain the Wigner rotation angle via the Fermi-Walker transport of spinors and consider the WKB (Wentzel-Kramers-Brillouin) approximation in order to study the influence of Lorentz symmetry breaking effects on the relativistic EPR correlations. (orig.)
Approximate gauge symemtry of composite vector bosons
Energy Technology Data Exchange (ETDEWEB)
Suzuki, Mahiko
2010-06-01
It can be shown in a solvable field theory model that the couplings of the composite vector mesons made of a fermion pair approach the gauge couplings in the limit of strong binding. Although this phenomenon may appear accidental and special to the vector bosons made of a fermion pair, we extend it to the case of bosons being constituents and find that the same phenomenon occurs in more an intriguing way. The functional formalism not only facilitates computation but also provides us with a better insight into the generating mechanism of approximate gauge symmetry, in particular, how the strong binding and global current conservation conspire to generate such an approximate symmetry. Remarks are made on its possible relevance or irrelevance to electroweak and higher symmetries.
2016-01-01
The Symmetry Festival is a science and art program series, the most important periodic event (see its history) to bring together scientists, artists, educators and practitioners interested in symmetry (its roots, what is behind, applications, etc.), or in the consequences of its absence.
Symmetries of Spectral Problems
Shabat, A.
Deriving abelian KdV and NLS hierarchies, we describe non-abelian symmetries and "pre-Lax" elementary approach to Lax pairs. Discrete symmetries of spectral problems are considered in Sect. 4.2. Here we prove Darboux classical theorem and discuss a modern theory of dressing chains.
Symmetries in Lagrangian Dynamics
Ferrario, Carlo; Passerini, Arianna
2007-01-01
In the framework of Noether's theorem, a distinction between Lagrangian and dynamical symmetries is made, in order to clarify some aspects neglected by textbooks. An intuitive setting of the concept of invariance of differential equations is presented. The analysis is completed by deriving the symmetry properties in the motion of a charged…
Meshkov, Sydney
2009-01-01
The study of the symmetries of nature has fascinated scientists for eons. The application of the formal mathematical description of symmetries during the last century has produced many breakthroughs in our understanding of the substructure of matter. In this talk, a number of these advances are discussed, and the important role that George Sudarshan played in their development is emphasized
Göckeler, M; Rakow, P E L; Schäfer, A; Wettig, T
2002-01-01
We calculate complete spectra of the Kogut-Susskind Dirac operator on the lattice in quenched SU(3) gauge theory for various values of coupling constant and lattice size. From these spectra we compute the connected and disconnected scalar susceptibilities and find agreement with chiral random matrix theory up to a certain energy scale, the Thouless energy. The dependence of this scale on the lattice volume is analyzed. In the case of the connected susceptibility this dependence is anomalous, and we explain the reason for this. We present a model of chiral perturbation theory that is capable of describing the data beyond the Thouless energy and that has a common range of applicability with chiral random matrix theory.
Akiyama, S; Akiyama, Satoru; Futami, Yasuhiko
2006-01-01
Mesonic fluctuations around the chiral solitons are investigated in the SU(3) chiral quark soliton model. Since the soliton takes the non-hedgehog shape for the hyperons and the hedgehog one for the non-hedgehog baryons in our approach, the fluctuations also change according to the baryonic state. The quantum corrections to the masses (the Casimir energies) are estimated for the octet and decuplet baryons. The lack of the confinement in this model demands the cutoff on the energy of the fluctuations. Under the assumption that the value of the cutoff energy is $2\\times$(the lightest constituent quark mass), these calculation reproduces the masses of the baryons within 15 % error.
International Nuclear Information System (INIS)
A possibility of 5D gauge unification of SU(2)LxU(1)Y in SU(3)W is examined. The orbifold compactification allows fixed points where SU(2)LxU(1)Y representations can be assigned. We present a few possibilities which give long proton lifetime, top-bottom mass hierarchy from geometry, and reasonable neutrino masses. In general, these chiral models can lead to fixed point anomalies. We can show easily, due to the simplicity of the model, that these anomalies are cancelled by the relevant Chern-Simons terms for all the models we consider. It is also shown that the fixed point U(1)-graviton-graviton anomaly cancels without the help from the Chern-Simons term. Hence, we conjecture that the fixed point anomalies can be cancelled if the effective 4D theory is made anomaly free by locating chiral fermions at the fixed points. (author)
International Nuclear Information System (INIS)
I carry out a finite-size scaling study of the correlation length in SU(3) lattice gauge theory coupled to 12 fundamental flavor fermions, using recent data published by Fodor, Holland, Kuti, Nogradi and Schroeder [Z. Fodor, K. Holland, J. Kuti, D. Nogradi, and C. Schroeder, Phys. Lett. B 703, 348 (2011).]. I make the assumption that the system is conformal in the zero-mass, infinite volume limit, that scaling is violated by both nonzero fermion mass and by finite volume, and that the scaling function in each channel is determined self-consistently by the data. From several different observables I extract a common exponent for the scaling of the correlation length ξ with the fermion mass mq, ξ∼mq-1/ym with ym∼1.35. Shortcomings of the analysis are discussed.
Graphical Tensor Product Reduction Scheme for the Lie Algebras so(5) = sp(2), su(3), and g(2)
Vlasii, N D; Wiese, U -J
2015-01-01
We develop in detail a graphical tensor product reduction scheme, first described by Antoine and Speiser, for the simple rank 2 Lie algebras so(5) = sp(2), su(3), and g(2). This leads to an efficient practical method to reduce tensor products of irreducible representations into sums of such representations. For this purpose, the 2-dimensional weight diagram of a given representation is placed in a "landscape" of irreducible representations. We provide both the landscapes and the weight diagrams for a large number of representations for the three simple rank 2 Lie algebras. We also apply the algebraic "girdle" method, which is much less efficient for calculations by hand for moderately large representations. Computer code for reducing tensor products, based on the graphical method, has been developed as well and is available from the authors upon request.
Scheme-Independent Calculation of $\\gamma_{\\bar\\psi\\psi,IR}$ for an SU(3) Gauge Theory
Ryttov, Thomas A
2016-01-01
We present a scheme-independent calculation of the infrared value of the anomalous dimension of the fermion bilinear, $\\gamma_{\\bar\\psi\\psi,IR}$ in an SU(3) gauge theory as a function of the number of fermions, $N_f$, via a series expansion in powers of $\\Delta_f$, where $\\Delta_f=(16.5-N_f)$, to order $\\Delta_f^4$. We perform an extrapolation to obtain the first determination of the exact $\\gamma_{\\bar\\psi\\psi,IR}$ from continuum field theory. The results are compared with calculations of the $n$-loop values of this anomalous dimension from series in powers of the coupling and from lattice measurements.
Graphical tensor product reduction scheme for the Lie algebras so(5) = sp(2) , su(3) , and g(2)
Vlasii, N. D.; von Rütte, F.; Wiese, U.-J.
2016-08-01
We develop in detail a graphical tensor product reduction scheme, first described by Antoine and Speiser, for the simple rank 2 Lie algebras so(5) = sp(2) , su(3) , and g(2) . This leads to an efficient practical method to reduce tensor products of irreducible representations into sums of such representations. For this purpose, the 2-dimensional weight diagram of a given representation is placed in a "landscape" of irreducible representations. We provide both the landscapes and the weight diagrams for a large number of representations for the three simple rank 2 Lie algebras. We also apply the algebraic "girdle" method, which is much less efficient for calculations by hand for moderately large representations. Computer code for reducing tensor products, based on the graphical method, has been developed as well and is available from the authors upon request.
Symmetry Effects in Computation
Yao, Andrew Chi-Chih
2008-12-01
The concept of symmetry has played a key role in the development of modern physics. For example, using symmetry, C.N. Yang and other physicists have greatly advanced our understanding of the fundamental laws of physics. Meanwhile, computer scientists have been pondering why some computational problems seem intractable, while others are easy. Just as in physics, the laws of computation sometimes can only be inferred indirectly by considerations of general principles such as symmetry. The symmetry properties of a function can indeed have a profound effect on how fast the function can be computed. In this talk, we present several elegant and surprising discoveries along this line, made by computer scientists using symmetry as their primary tool. Note from Publisher: This article contains the abstract only.
Loebbert, Florian
2016-01-01
In these introductory lectures we discuss the topic of Yangian symmetry from various perspectives. Forming the classical counterpart of the Yangian and an extension of ordinary Noether symmetries, first the concept of nonlocal charges in classical, two-dimensional field theory is reviewed. We then define the Yangian algebra following Drinfeld's original motivation to construct solutions to the quantum Yang-Baxter equation. Different realizations of the Yangian and its mathematical role as a Hopf algebra and quantum group are discussed. We demonstrate how the Yangian algebra is implemented in quantum, two-dimensional field theories and how its generators are renormalized. Implications of Yangian symmetry on the two-dimensional scattering matrix are investigated. We furthermore consider the important case of discrete Yangian symmetry realized on integrable spin chains. Finally we give a brief introduction to Yangian symmetry in planar, four-dimensional super Yang-Mills theory and indicate its impact on the dila...
Neutral kaons without Weisskopf-Wigner approximation
International Nuclear Information System (INIS)
The model-independent formalism is constructed to describe decays of mixed particles without using the Weisskopf-Wigner approximation (WWA). Limitations due to various symmetries are traced for neutral K mesons. As an application we show that effects of CPT violation and going beyond WWA may be separated and studied independently. 16 refs
Neutral Kaons without Weisskopf-Wigner Approximation
Azimov, Ya. I.
1995-01-01
The model-independent formalism is constructed to describe decays of mixed particles without using the Weisskopf-Wigner approximation. Limitations due to various symmetries are traced for neutral $K-$mesons. As an application we show that effects of $CPT-$violation and going beyond WWA may be separated and studied independently.
Weak mixing matrix under permutation symmetry breaking
International Nuclear Information System (INIS)
The two-Higgs-doublet extension of the standard electroweak model is considered. A permutation symmetry-breaking scheme is proposed and used to calculate the weak mixing matrix up to second order. The CP-violation factor J and the correction to Bjorken's approximation are then given. A special case is considered
Miyatsu, Tsuyoshi; Cheoun, Myung-Ki; Saito, Koichi
2015-11-01
We construct the equation of state (EoS) for neutron stars explicitly including hyperons and quarks. Using the quark-meson coupling model with the relativistic Hartree-Fock approximation, the EoS for hadronic matter is derived by taking into account the strange (σ* and ϕ) mesons as well as the light non-strange (σ, ω, {\\boldsymbol{π }}, and {\\boldsymbol{ρ }}) mesons. Relevant coupling constants are determined to reproduce the experimental data of nuclear matter and hypernuclei in SU(3) flavor symmetry. For quark matter, we employ the MIT bag model with a one-gluon-exchange interaction, and Gibbs criteria for chemical equilibrium in the phase transition from hadrons to quarks. We find that the strange vector (ϕ) meson and the Fock contribution make the hadronic EoS stiff, and that the maximum mass of a neutron star can be consistent with the observed mass of heavy neutron stars even if the coexistence of hadrons and quarks takes place in the core. However, in the present calculation, the transition to pure quark matter does not occur in stable neutron stars. Furthermore, the lower bound of the critical chemical potential of the quark-hadron transition at zero temperature turns out to be around 1.5 GeV in order to be consistent with the recent observed neutron-star data.
Vien, V V
2015-01-01
We construct a new version for the 3-3-1 model based on $T_7$ flavor symmetry where the left-handed leptons under $T_7$ differ from those of our previous work while the $\\mathrm{SU}(3)_C \\otimes \\mathrm{SU}(3)_L \\otimes \\mathrm{U}(1)_X$ gauge symmetry is retain. The flavor mixing patterns and mass splitting are obtained without perturbation. The realistic lepton mixing can be obtained if both the direction of breakings $T_7 \\rightarrow Z_3$ and $Z_3 \\rightarrow \\{\\mathrm{Identity}\\}$ are taken place in neutrino sector. Maximal CP violation is predicted and CKM matrix is the identity matrix at the tree-level.
On the symmetry breaking phenomenon
Birtea, Petre; Puta, Mircea; Ratiu, Tudor S.; Tudoran, Ruazvan Micu
2006-01-01
We investigate the problem of symmetry breaking in the framework of dynamical systems with symmetry on a smooth manifold. Two cases will be analyzed: general and Hamiltonian dynamical systems. We give sufficient conditions for symmetry breaking in both cases.
Gedanken worlds without Higgs fields: QCD-induced electroweak symmetry breaking
International Nuclear Information System (INIS)
To illuminate how electroweak symmetry breaking shapes the physical world, we investigate toy models in which no Higgs fields or other constructs are introduced to induce spontaneous symmetry breaking. Two models incorporate the standard SU(3)c x SU(2)L x U(1)Y gauge symmetry and fermion content similar to that of the standard model. The first class--like the standard electroweak theory--contains no bare mass terms, so the spontaneous breaking of chiral symmetry within quantum chromodynamics is the only source of electroweak symmetry breaking. The second class adds bare fermion masses sufficiently small that QCD remains the dominant source of electroweak symmetry breaking and the model can serve as a well-behaved low-energy effective field theory to energies somewhat above the hadronic scale. A third class of models is based on the left-right-symmetric SU(3)c x SU(2)L x SU(2)R x U(1) gauge group. In a fourth class of models, built on SU(4)PS x SU(2)L x SU(2)R gauge symmetry, the lepton number is treated as a fourth color and the color gauge group is enlarged to the SU(4)PS of Pati and Salam (PS). Many interesting characteristics of the models stem from the fact that the effective strength of the weak interactions is much closer to that of the residual strong interactions than in the real world. The Higgs-free models not only provide informative contrasts to the real world, but also lead us to consider intriguing issues in the application of field theory to the real world.
Flavor symmetries and fermion masses
International Nuclear Information System (INIS)
We introduce several ways in which approximate flavor symmetries act on fermions and which are consistent with observed fermion masses and mixings. Flavor changing interactions mediated by new scalars appear as a consequence of approximate flavor symmetries. We discuss the experimental limits on masses of the new scalars, and show that the masses can easily be of the order of weak scale. Some implications for neutrino physics are also discussed. Such flavor changing interactions would easily erase any primordial baryon asymmetry. We show that this situation can be saved by simply adding a new charged particle with its own asymmetry. The neutrality of the Universe, together with sphaleron processes, then ensures a survival of baryon asymmetry. Several topics on flavor structure of the supersymmetric grand unified theories are discussed. First, we show that the successful predictions for the Kobayashi-Maskawa mixing matrix elements, Vub/Vcb = √mu/mc and Vtd/Vts = √md/ms, are a consequence of a large class of models, rather than specific properties of a few models. Second, we discuss how the recent observation of the decay β → sγ constrains the parameter space when the ratio of the vacuum expectation values of the two Higgs doublets, tanΒ, is large. Finally, we discuss the flavor structure of proton decay. We observe a surprising enhancement of the branching ratio for the muon mode in SO(10) models compared to the same mode in the SU(5) model
Mapping moveout approximations in TI media
Stovas, Alexey
2013-11-21
Moveout approximations play a very important role in seismic modeling, inversion, and scanning for parameters in complex media. We developed a scheme to map one-way moveout approximations for transversely isotropic media with a vertical axis of symmetry (VTI), which is widely available, to the tilted case (TTI) by introducing the effective tilt angle. As a result, we obtained highly accurate TTI moveout equations analogous with their VTI counterparts. Our analysis showed that the most accurate approximation is obtained from the mapping of generalized approximation. The new moveout approximations allow for, as the examples demonstrate, accurate description of moveout in the TTI case even for vertical heterogeneity. The proposed moveout approximations can be easily used for inversion in a layered TTI medium because the parameters of these approximations explicitly depend on corresponding effective parameters in a layered VTI medium.
Counting trees using symmetries
Bernardi, Olivier
2012-01-01
We present a new approach for counting trees, and we apply it to count multitype Cayley trees and to prove the multivariate Lagrange inversion formula. The gist of our approach is to exploit the symmetries of refined enumerative formulas: proving these symmetries is easy, and once the symmetries are proved the formulas follow effortlessly. Somewhat surprisingly, our formula for the generating function of multitype Cayley trees appears to be new, and implies certain recent results by Bousquet-M\\'elou and Chapuy. We also adapt our approach to recover known enumerative formulas for cacti counted according to their degree distribution.
Schwichtenberg, Jakob
2015-01-01
This is a textbook that derives the fundamental theories of physics from symmetry. It starts by introducing, in a completely self-contained way, all mathematical tools needed to use symmetry ideas in physics. Thereafter, these tools are put into action and by using symmetry constraints, the fundamental equations of Quantum Mechanics, Quantum Field Theory, Electromagnetism, and Classical Mechanics are derived. As a result, the reader is able to understand the basic assumptions behind, and the connections between the modern theories of physics. The book concludes with first applications of the previously derived equations.
Symmetry in Boolean Satisfiability
Directory of Open Access Journals (Sweden)
Fadi A. Aloul
2010-06-01
Full Text Available This paper reviews recent approaches on how to accelerate Boolean Satisfiability (SAT search by exploiting symmetries in the problem space. SAT search algorithms traverse an exponentially large search space looking for an assignment that satisfies a set of constraints. The presence of symmetries in the search space induces equivalence classes on the set of truth assignments. The goal is to use symmetries to avoid traversing all assignments by constraining the search to visit a few representative assignments in each equivalence class. This can lead to a significant reduction in search runtime without affecting the completeness of the search.
Sequential flavor symmetry breaking
International Nuclear Information System (INIS)
The gauge sector of the standard model exhibits a flavor symmetry that allows for independent unitary transformations of the fermion multiplets. In the standard model the flavor symmetry is broken by the Yukawa couplings to the Higgs boson, and the resulting fermion masses and mixing angles show a pronounced hierarchy. In this work we connect the observed hierarchy to a sequence of intermediate effective theories, where the flavor symmetries are broken in a stepwise fashion by vacuum expectation values of suitably constructed spurion fields. We identify the possible scenarios in the quark sector and discuss some implications of this approach.
DEFF Research Database (Denmark)
Avery, John Scales; Rettrup, Sten; Avery, James Emil
In theoretical physics, theoretical chemistry and engineering, one often wishes to solve partial differential equations subject to a set of boundary conditions. This gives rise to eigenvalue problems of which some solutions may be very difficult to find. For example, the problem of finding...... such problems can be much reduced by making use of symmetry-adapted basis functions. The conventional method for generating symmetry-adapted basis sets is through the application of group theory, but this can be difficult. This book describes an easier method for generating symmetry-adapted basis sets...
Kuramashi, Yoshinobu; Takeda, Shinji; Ukawa, Akira
2016-01-01
We investigate the critical endline of the finite temperature phase transition of QCD around the SU(3)-flavor symmetric point at zero chemical potential. We employ the renormalization-group improved Iwasaki gauge action and non-perturbatively $O(a)$-improved Wilson-clover fermion action. The critical endline is determined by using the intersection point of kurtosis, employing the multi-parameter, multi-ensemble reweighting method to calculate observables off the SU(3)-symmetric point, at the temporal size $N_{\\rm T}$=6 and lattice spacing as low as $a \\approx 0.19$ fm. We confirm that the slope of the critical endline takes the value of $-2$, and find that the second derivative is positive, at the SU(3)-flavor symmetric point on the Columbia plot parametrized with the strange quark mass $m_s$ and degenerated up-down quark mass $m_{\\rm l}$.
Diophantine approximation and badly approximable sets
DEFF Research Database (Denmark)
Kristensen, S.; Thorn, R.; Velani, S.
2006-01-01
Let (X,d) be a metric space and (Omega, d) a compact subspace of X which supports a non-atomic finite measure m. We consider `natural' classes of badly approximable subsets of Omega. Loosely speaking, these consist of points in Omega which `stay clear' of some given set of points in X....... The classical set Bad of `badly approximable' numbers in the theory of Diophantine approximation falls within our framework as do the sets Bad(i,j) of simultaneously badly approximable numbers. Under various natural conditions we prove that the badly approximable subsets of Omega have full Hausdorff dimension...
Baryogenesis in AN SO(10) GUT Model with Pati-Salam Intermediate Symmetry
Buccella, F.; Pisanti, O.; Rosa, L.
The possibility of generating the observed baryon asymmetry of the universe in an SO(10) gauge model with spontaneous symmetry breaking pattern SO(10) MX--> SU(4){ PS} ⊗ SU(2)L ⊗ SU(2)R MR--> SU(3)c ⊗ SU(2)L ⊗ U(1)Y MZ--> SU(3)c ⊗ U(1)Q} is studied. We find it possible to generate a Δ B= {nB-n_{bar B}/{s} ˜ 10-11, converting the leptonic number produced at the B- L breaking scale via the B+L violating processes mediated by sphalerons at the electroweak scale. The resulting picture is tested against the limit coming from experimental data: proton lifetime and neutrino oscillations.
Quark-flavour phenomenology of models with extended gauge symmetries
International Nuclear Information System (INIS)
Gauge invariance is one of the fundamental principles of the Standard Model of particles and interactions, and it is reasonable to believe that it also regulates the physics beyond it. In this thesis we have studied the theory and phenomenology of two New Physics models based on gauge symmetries that are extensions of the Standard Model group. Both of them are particularly interesting because they provide some answers to the question of the origin of flavour, which is still unexplained. Moreover, the flavour sector represents a promising field for the research of indirect signatures of New Physics, since after the first run of LHC we do not have any direct hint of it yet. The first model assumes that flavour is a gauge symmetry of nature, SU(3)3f, spontaneously broken by the vacuum expectation values of new scalar fields; the second model is based on the gauge group SU(3)c x SU(3)L x U(1)X, the simplest non-abelian extension of the Standard Model group. We have traced the complete theoretical building of the models, from the gauge group, passing through the nonanomalous fermion contents and the appropriate symmetry breakings, up to the spectra and the Feynman rules, with a particular attention to the treatment of the flavour structure, of tree-level Flavour Changing Neutral Currents and of new CP-violating phases. In fact, these models present an interesting flavour phenomenology, and for both of them we have analytically calculated the contributions to the ΔF=2 and ΔF=1 down-type transitions, arising from new tree-level and box diagrams. Subsequently, we have performed a comprehensive numerical analysis of the phenomenology of the two models. In both cases we have found very effective the strategy of first to identify the quantities able to provide the strongest constraints to the parameter space, then to systematically scan the allowed regions of the latter in order to obtain indications about the key flavour observables, namely the mixing parameters of the
International Nuclear Information System (INIS)
The purpose of this course is to study the evolution of the symmetry concept and establish its influence in the knowledge of the fundamental laws of nature. Physicist have been using the symmetry concept in two ways: to solve problems and to search for new understanding of the world around us. In quantum physics symmetry plays a key role in gaining an understanding of the physical laws governing the behavior of matter and field systems. It provides, generally, a shortcut based on geometry for discovering the secrets of the Universe. Because it is believed that the laws of physics are invariant under discrete and continuous transformation operations of the space and time, there are continuous symmetries, for example, energy and momentum together with discrete ones corresponding to charge, parity and time reversal operations.
Global Bifurcations With Symmetry
Porter, J B
2001-01-01
Symmetry is a ubiquitous feature of physical systems with profound implications for their dynamics. This thesis investigates the role of symmetry in global bifurcations. In particular, the structure imposed by symmetry can encourage the formation of complex solutions such as heteroclinic cycles and chaotic invariant sets. The first study focuses on the dynamics of 1:n steady-state mode interactions in the presence of O(2) symmetry. The normal form equations considered are relevant to a variety of physical problems including Rayleigh-Bénard convection with periodic boundary conditions. In open regions of parameter space these equations contain structurally stable heteroclinic cycles composed of connections between standing wave, pure mode, and trivial solutions. These structurally stable cycles exist between two global bifurcations, the second of which involves an additional mixed mode state and creates as many as four distinct kinds of structurally unstable heteroclinic cycles. The various cycles c...
Gauge symmetry from decoupling
Wetterich, C
2016-01-01
Gauge symmetries emerge from a redundant description of the effective action for light degrees of freedom after the decoupling of heavy modes. This redundant description avoids the use of explicit constraints in configuration space. For non-linear constraints the gauge symmetries are non-linear. In a quantum field theory setting the gauge symmetries are local and can describe Yang-Mills theories or quantum gravity. We formulate gauge invariant fields that correspond to the non-linear light degrees of freedom. In the context of functional renormalization gauge symmetries can emerge if the flow generates or preserves large mass-like terms for the heavy degrees of freedom. They correspond to a particular form of gauge fixing terms in quantum field theories.
International Nuclear Information System (INIS)
In the present work, we elucidate the meaning of the custodial symmetry and its importance at the phenomenological level in the framework of the standard model of the electroweak interactions and its possible extensions. (Author)
Golubitsky, Martin
2012-04-01
Many gaits of four-legged animals are described by symmetry. For example, when a horse paces it moves both left legs in unison and then both right legs and so on. The motion is described by two symmetries: Interchange front and back legs, and swap left and right legs with a half-period phase shift. Biologists postulate the existence of a central pattern generator (CPG) in the neuronal system that sends periodic signals to the legs. CPGs can be thought of as electrical circuits that produce periodic signals and can be modeled by systems with symmetry. In this lecture we discuss animal gaits; use gait symmetries to construct a simplest CPG architecture that naturally produces quadrupedal gait rhythms; and make several testable predictions about gaits.
Symmetry, conservation laws, and theoretical particle physics
Krumins, Andris Visvaldis
In this work, we trace the role of symmetry throughout the history of theoretical particle physics, paying particular attention to the role of group theory, the formal mathematics of symmetry. After an analysis of the role of conservation laws and invariance in the theory of general relativity, we move on to Weyl's gauge theory of 1918, which was developed within the context of general relativity as an attempt to unify gravitation and electromagnetism. Weyl was trying to exploit an invariance of scale, and although his theory was experimentally refuted, it provided a formulation of the conservation of charge. After the advent of quantum mechanics, gauge theory was reinterpreted by London as an invariance of the wave-function. Weyl and Wigner studied group theory in the context of quantum mechanics, but the broadness of its application had yet to be appreciated. Symmetry was soon exploited in the nuclear interactions, however, and we examine the events leading to the discovery of SU(2) of isotopic spin. We analyze how the discovery of strangeness was linked to the generalization of SU(2) to SU(3), and also how it led to a differentiation between the strong interactions, which conserve isotopic spin and strangeness, and the weak interactions, which violate these conservation laws, along with the conservation of parity. Yang and Mills were impressed with gauge invariance, and in 1954, they took the bold step of imposing it upon the Lagrangian of the strong interactions, forcing the introduction of three new gauge fields. There was a problem, however, because although the short-range of the strong interactions implied that these gauge bosons should be massive, they needed to be massless in order to preserve gauge invariance. In addition, efforts were made to extend Yang-Mills theory to the weak interactions, but they also faced the same zero-mass problem. This problem was finally solved in 1967, when Weinberg and Salam showed how gauge boson masses could be generated
Second order symmetry operators
International Nuclear Information System (INIS)
Using systematic calculations in spinor language, we obtain simple descriptions of the second order symmetry operators for the conformal wave equation, the Dirac–Weyl equation and the Maxwell equation on a curved four-dimensional Lorentzian manifold. The conditions for existence of symmetry operators for the different equations are seen to be related. Computer algebra tools have been developed and used to systematically reduce the equations to a form which allows geometrical interpretation. (paper)
IBM: discrete symmetry viewpoint
International Nuclear Information System (INIS)
It is shown that the set of information of the s and d boson operators which maintain the IBM-like form of the Hamiltonian comprises a discrete point symmetry group D2'. The transformations manifest themselves as a parameter symmetry of the IBM-1 Hamiltonian. The transformations considered are also necessary for constructing the most general IBM-2 Hamiltonian. The properties of the potential energy surfaces arising in connection with these transformations are discussed
Quaternion family symmetry of quarks and leptons
International Nuclear Information System (INIS)
To a first approximation, the quark mixing matrix has θ13q=θ23q=0, whereas the lepton mixing matrix has θ23l=π/4. We show how this structure may be understood if the family symmetry is Q8, the quaternion group of eight elements. We find three viable scenarios for the Majorana neutrino mass matrix, each depending on four parameters and predicting a specific mass spectrum. The phenomenology of the two Higgs doublets which generate the Yukawa sector is analyzed and testable predictions are derived. We discuss also the closely related model based on D4, the symmetry group of the square
Special conformal symmetry of worldvolume actions
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Kappa-symmetric worldvolume actions of the D3-, M5-, and M2-branes can be coupled consistently to their near horizon bosonic geometry background. We study the gauge-fixed action in the approximation in which only the transverse radial direction of the brane is allowed to fluctuate. The generalized special conformal symmetry of these self-interacting actions is established. This opens up the possibility to find out if the full superconformal symmetry of the free actions of these branes survives in the presence of coupling defined by the size of the anti endash de Sitter throat. copyright 1998 The American Physical Society
Variants of fattening and flavor symmetry restoration
Orginos, K; Toussaint, D; Orginos, Kostas; Toussaint, Doug
1999-01-01
We study the effects of different "fat link" actions for Kogut-Susskind quarks on flavor symmetry breaking. Our method is mostly empirical - we compute the pion spectrum with different valence quark actions on common sets of sample lattices. Different actions are compared, as best we can, at equivalent physical points. We find significant reductions in flavor symmetry breaking relative to the conventional or to the "link plus staple" actions, with a reasonable cost in computer time. We also develop and test a scheme for approximate unitarization of the fat links. While our tests have concentrated on the valence quark action, our results will be useful in designing simulations with dynamical quarks.
Chiral symmetry breaking in lattice electrodynamics
International Nuclear Information System (INIS)
Chiral symmetry breaking is studied in lattice quantum electrodynamics in the quenched approximation by computer-simulation methods. Simulations at zero temperature show that in non-zero for all couplings e2 greater than a critical value e2/sub c/. The sensitivity of to short-distance features of the lattice Action is studied by simulating variant gauge Actions. Simulations on asymmetric lattices do not reveal significant temperature dependence in the symmetry-breaking dynamics. Subtle effects and limitations of quenched calculations are discussed
IBM: parameter symmetry, hidden symmetries and transformations of boson operators
International Nuclear Information System (INIS)
A symmetry of the parameter space of interacting boson models IBM-1 and IBM-2 is studied. The symmetry is associated with linear canonical transformations of boson operators, or, equivalently, with the existence of different realizations of the symmetry algebras of the models. The relevance of the parameter symmetry to physical observables is discussed. (Author)
International Nuclear Information System (INIS)
This thesis deals with the possibility of describing the flavor sector of the Standard Model of Particle Physics (with neutrino masses), that is the fermion masses and mixing matrices, with a discrete, non-abelian flavor symmetry. In particular, mass independent textures are considered, where one or several of the mixing angles are determined by group theory alone and are independent of the fermion masses. To this end a systematic analysis of a large class of discrete symmetries, the dihedral groups, is analyzed. Mass independent textures originating from such symmetries are described and it is shown that such structures arise naturally from the minimization of scalar potentials, where the scalars are gauge singlet flavons transforming non-trivially only under the flavor group. Two models are constructed from this input, one describing leptons, based on the group D4, the other describing quarks and employing the symmetry D14. In the latter model it is the quark mixing matrix element Vud - basically the Cabibbo angle - which is at leading order predicted from group theory. Finally, discrete flavor groups are discussed as subgroups of a continuous gauge symmetry and it is shown that this implies that the original gauge symmetry is broken by fairly large representations. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Blum, Alexander Simon
2009-06-10
This thesis deals with the possibility of describing the flavor sector of the Standard Model of Particle Physics (with neutrino masses), that is the fermion masses and mixing matrices, with a discrete, non-abelian flavor symmetry. In particular, mass independent textures are considered, where one or several of the mixing angles are determined by group theory alone and are independent of the fermion masses. To this end a systematic analysis of a large class of discrete symmetries, the dihedral groups, is analyzed. Mass independent textures originating from such symmetries are described and it is shown that such structures arise naturally from the minimization of scalar potentials, where the scalars are gauge singlet flavons transforming non-trivially only under the flavor group. Two models are constructed from this input, one describing leptons, based on the group D{sub 4}, the other describing quarks and employing the symmetry D{sub 14}. In the latter model it is the quark mixing matrix element V{sub ud} - basically the Cabibbo angle - which is at leading order predicted from group theory. Finally, discrete flavor groups are discussed as subgroups of a continuous gauge symmetry and it is shown that this implies that the original gauge symmetry is broken by fairly large representations. (orig.)
International Nuclear Information System (INIS)
This talk explores the role that U(1) (or some discrete) R-symmetries can play in the construction of realistic supersymmetric models. By exploiting U(1)R, the first part attempts to obtain a more robust version of MSSM in which neutrinos are massive and the resolution of the μ and strong CP problems is intimately related. The second part goes beyond the MSSM gauge group by considering SU(3)cxSU(2)LxSU(2)RxU(1)B-L, supplemented by U(1)R. The parameter tan ampersand hthinsp;β≅mt/mb, which allows one to predict the top quark mass in the right ball park, and also explain why the open-quote standard model close-quote higgs h degree has so far not been found at LEPII. Its tree level mass is MZdegree and, after radiative corrections, one expects mhdegree∼110±10 ampersand hthinsp;GeV. This particular scheme also resolves the μ problem of MSSM and enables one to realize an inflationary epoch with the spectral index of density fluctuations very close to unity (n∼0.98). copyright 1998 American Institute of Physics
Gauge Symmetry Breaking Patterns in an SU(5) Grand Gauge-Higgs Unification
Kojima, Kentaro; Yamashita, Toshifumi
2016-01-01
We study gauge symmetry breaking patterns of the five-dimensional $SU(5)$ grand gauge-Higgs unification compactified on an orbifold $S^1/{\\mathbb Z}_2$ with the Hosotani mechanism in the framework of the diagonal embedding method. We find matter contents that lead to the $SU(3)\\times SU(2)\\times U(1)$ gauge symmetry on the global minimum of the effective potential and also present examples of matter content for which each regular subgroup of $SU(5)$ is realized as vacuum configuration. The finite temperature phase transitions for the models with the gauge symmetry of the standard model at zero temperature and also for supersymmetric models are studied. We show in a certain model with supersymmetry that the vacuum of the standard model selected dynamically before the inflation continues to stay there up to the present.
Two-loop study of the deconfinement transition in Yang-Mills theories: SU(3) and beyond
Reinosa, U.; Serreau, J.; Tissier, M.; Wschebor, N.
2016-05-01
We study the confinement-deconfinement phase transition of pure Yang-Mills theories at finite temperature using a simple massive extension of standard background field methods. We generalize our recent next-to-leading-order perturbative calculation of the Polyakov loop and of the related background field effective potential for the SU(2) theory to any compact and connex Lie group with a simple Lie algebra. We discuss in detail the SU(3) theory, where the two-loop corrections yield improved values for the first-order transition temperature as compared to the one-loop result. We also show that certain one-loop artifacts of thermodynamical observables disappear at two-loop order, as was already the case for the SU(2) theory. In particular, the entropy and the pressure are positive for all temperatures. Finally, we discuss the groups SU(4) and Sp(2) which shed interesting light, respectively, on the relation between the (de)confinement of static matter sources in the various representations of the gauge group and on the use of the background field itself as an order parameter for confinement. In both cases, we obtain first-order transitions, in agreement with lattice simulations and other continuum approaches.
A two-loop study of the deconfinement transition in Yang-Mills theories: SU(3) and beyond
Reinosa, U; Tissier, M; Wschebor, N
2015-01-01
We study the confinement-deconfinement phase transition of pure Yang-Mills theories at finite temperature within a simple massive extension of standard background field methods. We generalize our recent next-to-leading-order perturbative calculation of the Polyakov loop and the related background field effective potential for the SU(2) theory to any compact and connex Lie group with a simple Lie algebra. We discuss in detail the SU(3) theory, where the two-loop corrections yield improved values for the first order transition temperature as compared to the one-loop result. We show that certain one-loop artifacts of thermodynamical observables disappear at two-loop order, as was already the case for the SU(2) theory. In particular, the entropy and the pressure are positive for all temperatures. We also discuss the groups SU(4) and Sp(2) which shed interesting light, respectively, on the relation between the (de)confinement of static matter sources in the various representations of the gauge group and on the use...
Ananthanarayan, B; Imsong, I Sentitemsu
2012-01-01
AMPCALCULATOR is a mathematica-based program that was made publicly available some time ago by Unterdorfer and Ecker. It enables the user to compute several processes upto $O(p^4)$ in SU(3) chiral perturbation theory. They include computing matrix elements and form factors for strong and nonleptonic weak processes with at most six external states. It was used to compute some novel processes and was tested against some well-known results by the original authors. Here we present the results of several thorough checks of the package. Exhaustive checks performed by the original authors are not publicly available, and hence the present effort. Some new results are obtained from the software especially in the kaon odd-intrinsic parity nonleptonic decay sector involving the coupling $G_{27}$. Another illustrative set of amplitudes at tree level we provide is in the context of $\\tau$-decays with several mesons including quark mass effects, of use to the BELLE experiment. All eight meson-meson scattering amplitudes ha...
Neutral B-meson mixing from three-flavor lattice QCD: Determination of the SU(3)-breaking ratio \\xi
Bazavov, A; Bouchard, C M; DeTar, C; Di Pierro, M; El-Khadra, A X; Evans, R T; Freeland, E D; Gamiz, E; Gottlieb, Steven; Heller, U M; Hetrick, J E; Jain, R; Kronfeld, A S; Laiho, J; Levkova, L; Mackenzie, P B; Neil, E T; Oktay, M B; Simone, J N; Sugar, R; Toussaint, D; Van de Water, R S
2012-01-01
We study SU(3)-breaking effects in the neutral B_d-\\bar B_d and B_s-\\bar B_s systems with unquenched N_f=2+1 lattice QCD. We calculate the relevant matrix elements on the MILC collaboration's gauge configurations with asqtad-improved staggered sea quarks. For the valence light-quarks (u, d, and s) we use the asqtad action, while for b quarks we use the Fermilab action. We obtain \\xi=f_{B_s}\\sqrt{B_{B_s}}/f_{B_d}\\sqrt{B_{B_d}}=1.268+-0.063. We also present results for the ratio of bag parameters B_{B_s}/B_{B_d} and the ratio of CKM matrix elements |V_{td}|/|V_{ts}|. Although we focus on the calculation of \\xi, the strategy and techniques described here will be employed in future extended studies of the B mixing parameters \\Delta M_{d,s} and \\Delta\\Gamma_{d,s} in the Standard Model and beyond.
Hidden symmetries and critical dimensions in the theory of modulated structures
International Nuclear Information System (INIS)
Some aspects of the theory of the critical phenomena in systems with spontaneous symmetry breaking are considered. The applicability range of the mean field approximation for the systems with modulated structures is discussed. Connection between symmetries of a corresponding model and the existence of exact solutions is showed. The role of symmetries in the theory of dynamic long range ordering is discussed
Medium effect on charge symmetry breaking
International Nuclear Information System (INIS)
We examine the nuclear medium effect on charge symmetry breaking (CSB) caused by isospin mixing of two neutral vector mesons interacting with nucleons in the nuclear medium. Isospin mixing is assumed to occur through the transition between isoscalar and isovector mesons. We use a quantum hadrodynamic nuclear model in the mean-field approximation for the meson fields involved. We find that (i) charge symmetry is gradually restored in nuclear matter in β equilibrium as the nucleon density increases; (ii) when the system departs from β equilibrium, CSB is much enhanced because the isospin mixing depends strongly on the nucleon isovector density; (iii) this leads to the symmetry energy coefficient of 32MeV, of which more than 50 percent arises from the mesonic mean fields; (iv) the Nolen-Schiffer anomaly regarding the masses of neighboring mirror nuclei can be resolved by considering these aspects of CSB in nuclear medium. copyright 1997 The American Physical Society
International Nuclear Information System (INIS)
In a class of SUSY SO(10) with SU(2)L x SU(2)R x U(1)B-L x SU(3)C(g2L≠g2R) intermediate gauge symmetry, we observe that the prediction on the unification mass (MU) is unaffected by Planck-scale-induced gravitational and intermediate-scale threshold effects, although the intermediate scale (MI) itself is subject to such corrections. In particular, without invoking the presence of additional lighter scalar degrees of freedom but including plausible and reasonable threshold effects, we find that interesting solutions for neutrino physics corresponding to MI≅1010-1013 GeV and MU≅(5-6) x 1017 GeV are permitted in the minimal models. The possibilities of low-mass right-handed gauge bosons corresponding to MI≅1-10 TeV consistent with the CERN-LEP data are pointed out in a number of models in which threshold effects are included using effective mass parameters. (orig.)