10,642 research outputs found

    Reconstruction of the spontaneously broken gauge theory in non-commutative geometry

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    The scheme previously proposed by the present authors is modified to incorporate the strong interaction by affording the direct product internal symmetry. We do not need to prepare the extra discrete space for the color gauge group responsible for the strong interaction to reconstruct the standard model and the left-right symmetric gauge model(LRSM). The approach based on non-commutative geometry leads us to presents many attractive points such as the unified picture of the gauge and Higgs field as the generalized connection on the discrete space; Minkowski space multipied by N-points discrete space. This approach leads us to unified picture of gauge and Higgs fields as the generalized connection. The standard model needs N=2 discrete space for reconstruction in this formalism. \lr is still alive as a model with the intermediate symmetry of the spontaneously broken SO(10) grand unified theory(GUT). N=3 discrete space is needed for the reconstruction of LRSM to include two Higgs bosons ϕ\phi and ξ\xi which are as usual transformed as (2,2*,0)$ and (1,3,-2) under left-handed SU(2)x right-handed SU(2)x U(1), respectively. xi is responsible to make the right handed-neutrino Majorana fermion and so well explains the seesaw mechanism. Up and down quarks have the different masses through the vacuum expectation value of phi.Comment: 21 page

    Field Theory in Noncommutative Minkowski Superspace

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    There is much discussion of scenarios where the space-time coordinates x^\mu are noncommutative. The discussion has been extended to include nontrivial anticommutation relations among spinor coordinates in superspace. A number of authors have studied field theoretical consequences of the deformation of N=1 superspace arising from nonanticommutativity of coordinates \theta, while leaving \bar{theta}'s anticommuting. This is possible in Euclidean superspace only. In this note we present a way to extend the discussion by making both \theta and \bar{theta} coordinates non-anticommuting in Minkowski superspace. We present a consistent algebra for the supercoordinates, find a star-product, and give the Wess-Zumino Lagrangian L_{WZ} within our model. It has two extra terms due to non(anti)commutativity. The Lagrangian in Minkowski superspace is always manifestly Hermitian and for L_{WZ} it preserves Lorentz invariance.Comment: 8 pages, added references, two-column format, published in PR

    Quaternion Octonion Reformulation of Quantum Chromodynamics

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    We have made an attempt to develop the quaternionic formulation of Yang - Mill's field equations and octonion reformulation of quantum chromo dynamics (QCD). Starting with the Lagrangian density, we have discussed the field equations of SU(2) and SU(3) gauge fields for both cases of global and local gauge symmetries. It has been shown that the three quaternion units explain the structure of Yang- Mill's field while the seven octonion units provide the consistent structure of SU(3)_{C} gauge symmetry of quantum chromo dynamics

    BRST invariant Lagrangian of spontaneously broken gauge theories in noncommutative geometry

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    The quantization of spontaneously broken gauge theories in noncommutative geometry(NCG) has been sought for some time, because quantization is crucial for making the NCG approach a reliable and physically acceptable theory. Lee, Hwang and Ne'eman recently succeeded in realizing the BRST quantization of gauge theories in NCG in the matrix derivative approach proposed by Coquereaux et al. The present author has proposed a characteristic formulation to reconstruct a gauge theory in NCG on the discrete space M4×ZNM_4\times Z_{_N}. Since this formulation is a generalization of the differential geometry on the ordinary manifold to that on the discrete manifold, it is more familiar than other approaches. In this paper, we show that within our formulation we can obtain the BRST invariant Lagrangian in the same way as Lee, Hwang and Ne'eman and apply it to the SU(2)×\timesU(1) gauge theory.Comment: RevTeX, page

    Quaternion-Octonion SU(3) Flavor Symmetry

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    Starting with the quaternionic formulation of isospin SU(2) group, we have derived the relations for different components of isospin with quark states. Extending this formalism to the case of SU(3) group we have considered the theory of octonion variables. Accordingly, the octonion splitting of SU(3) group have been reconsidered and various commutation relations for SU(3) group and its shift operators are also derived and verified for different iso-spin multiplets i.e. I, U and V- spins. Keywords: SU(3), Quaternions, Octonions and Gell Mann matrices PACS NO: 11.30.Hv: Flavor symmetries; 12.10-Dm: Unified field theories and models of strong and electroweak interaction

    In-medium modification of P-wave charmonia from QCD sum rules

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    We investigate the changes of the masses and widths of χc0\chi_{c0} and χc1\chi_{c1} in hot gluonic matter near TcT_c and in nuclear medium using QCD sum rules. As in the previous works for the J/ψJ/\psi and ηc\eta_c, in-medium effects are incorporated through the changes of gluon condensates. Twist-2 terms for the 3P0(χc0)^3 P_0 (\chi_{c0}) and 3P1(χc1)^3 P_1 (\chi_{c1}) are also included for the first time. The results show that larger mass shifts and width broadenings take place as compared to the SS-wave states. As the critical change take place near TcT_c, related measurements can reveal critical phenomenon in QCD.Comment: 7 pages, 6 figures, to be published in Phys.Rev.

    Residue network in protein native structure belongs to the universality class of three dimensional critical percolation cluster

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    A single protein molecule is regarded as a contact network of amino-acid residues. Some studies have indicated that this network is a small world network (SWN), while other results have implied that this is a fractal network (FN). However, SWN and FN are essentially different in the dependence of the shortest path length on the number of nodes. In this paper, we investigate this dependence in the residue contact networks of proteins in native structures, and show that the networks are not SWN but FN. FN is generally characterized by several dimensions. Among them, we focus on three dimensions; the network topological dimension DcD_c, the fractal dimension DfD_f, and the spectral dimension DsD_s. We find that proteins universally yield Dc1.9D_c \approx 1.9, Df2.5D_f \approx 2.5 and Ds1.3Ds \approx 1.3. These values are in surprisingly good coincidence with those in three dimensional critical percolation cluster. Hence the residue contact networks in the protein native structures belong to the universality class of three dimensional percolation cluster. The criticality is relevant to the ambivalent nature of the protein native structures, i.e., the coexistence of stability and instability, both of which are necessary for a protein to function as a molecular machine or an allosteric enzyme.Comment: 4 pages, 3 figure

    Critical Behavior of J/psi across the Phase Transition from QCD sum rules

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    We study behavior of J/psi in hot gluonic matter using QCD sum rules. Taking into account temperature dependences of the gluon condensates extracted from lattice thermodynamics for the pure SU(3) system, we find that the mass and width of J/psi exhibit rapid change across the critical temperature.Comment: 5 pages, 3 figures. Poster contribution for Quark Matter 2008. To be published in the proceeding

    On the Energy Required to Eject Processed Matter from Galaxies

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    We evaluate the minimum energy input rate that starbursts require for expelling their newly processed matter from their host galaxies. Special attention is given to the pressure caused by the environment in which a galaxy is situated, as well as to the intrinsic rotation of the gaseous component. We account for these factors and for a massive dark matter distribution, and develop a self-consistent solution for the interstellar matter gas distribution. Our results are in excellent agreement with the results of Mac Low & Ferrara (1999) for galaxies with a flattened disk-like ISM density distribution and a low intergalactic gas pressure (PIGM/kP_{IGM}/k \leq 1 cm3^{-3} K). However, our solution also requires a much larger energy input rate threshold when one takes into consideration both a larger intergalactic pressure and the possible existence of a low-density, non-rotating, extended gaseous halo component.Comment: 7 pages, 4 figures, 1 table, Accepted for publication in Ap
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