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Sample records for electroweak chiral lagrangian

  1. Electroweak chiral Lagrangian from a natural topcolor-assisted technicolor model

    International Nuclear Information System (INIS)

    Lang Junyi; Jiang Shaozhou; Wang Qing

    2009-01-01

    Based on previous studies on computing coefficients of the electroweak chiral Lagrangian from C. T. Hill's schematic topcolor-assisted technicolor model, we generalize the calculation to K. Lane's prototype natural topcolor-assisted technicolor model. We find that typical features of the model are qualitatively similar to those of Hill's, but Lane's model prefers a smaller technicolor group and the Z ' mass must be smaller than 400 GeV. Furthermore, the S parameter is around the order of +1, mainly due to the existence of three doublets of techniquarks. We obtain the values for all coefficients of the electroweak chiral Lagrangian up to the order p 4 . Apart from large negative four-fermion coupling values, the extended technicolor impacts on the electroweak chiral Lagrangian coefficients are small, since the techniquark self energy, which determines these coefficients, in general receives almost no influence from the extended technicolor induced four-fermion interactions except for its large momentum tail.

  2. Complete one-loop renormalization of the Higgs-electroweak chiral Lagrangian

    Science.gov (United States)

    Buchalla, G.; Catà, O.; Celis, A.; Knecht, M.; Krause, C.

    2018-03-01

    Employing background-field method and super-heat-kernel expansion, we compute the complete one-loop renormalization of the electroweak chiral Lagrangian with a light Higgs boson. Earlier results from purely scalar fluctuations are confirmed as a special case. We also recover the one-loop renormalization of the conventional Standard Model in the appropriate limit.

  3. Electroweak chiral Lagrangian from the topcolor-assisted technicolor model with nontrivial technicolor fermion condensation and walking

    International Nuclear Information System (INIS)

    Ge Fengjun; Jiang Shaozhou; Wang Qing

    2011-01-01

    The electroweak chiral Lagrangian for the topcolor-assisted technicolor model proposed by K. Lane, which uses nontrivial patterns of techniquark condensation and walking, was investigated in this study. We found that the features of the model are qualitatively similar to those of Lane's previous natural topcolor-assisted technicolor prototype model, but there is no limit on the upper bound of the Z ' mass. We discuss the phase structure and possible walking behavior of the model. We obtained the values of all coefficients of the electroweak chiral Lagrangian up to an order of p 4 . We show that although the walking effect reduces the S parameter to half its original value, it maintains an order of 2. Moreover, a special hypercharge arrangement is needed to achieve further reductions in its value.

  4. Chiral Lagrangians and the SSC

    International Nuclear Information System (INIS)

    Dawson, S.

    1991-09-01

    In the event that the SSC does not observe any resonances such as a Higgs boson or a techni-rho meson, we would like to know if the SSC can still discover something about the nature of the electroweak symmetry breaking. We will use chiral Lagrangian techniques to address this question and analyze their utility for studying events containing W and Z gauge bosons at the SSC. 20 refs., 4 figs

  5. Fingerprints of heavy scales in electroweak effective Lagrangians

    Science.gov (United States)

    Pich, Antonio; Rosell, Ignasi; Santos, Joaquín; Sanz-Cillero, Juan José

    2017-04-01

    The couplings of the electroweak effective theory contain information on the heavy-mass scales which are no-longer present in the low-energy Lagrangian. We build a general effective Lagrangian, implementing the electroweak chiral symmetry breaking SU(2) L ⊗ SU(2) R → SU(2) L+ R , which couples the known particle fields to heavier states with bosonic quantum numbers J P = 0± and 1±. We consider colour-singlet heavy fields that are in singlet or triplet representations of the electroweak group. Integrating out these heavy scales, we analyze the pattern of low-energy couplings among the light fields which are generated by the massive states. We adopt a generic non-linear realization of the electroweak symmetry breaking with a singlet Higgs, without making any assumption about its possible doublet structure. Special attention is given to the different possible descriptions of massive spin-1 fields and the differences arising from naive implementations of these formalisms, showing their full equivalence once a proper short-distance behaviour is required.

  6. Fingerprints of heavy scales in electroweak effective Lagrangians

    Energy Technology Data Exchange (ETDEWEB)

    Pich, Antonio [Departament de Física Teòrica, IFIC, Universitat de València - CSIC,Apt. Correus 22085, E-46071 València (Spain); Rosell, Ignasi [Departamento de Matemáticas, Física y Ciencias Tecnológicas,Universidad CEU Cardenal Herrera, E-46115 Alfara del Patriarca, València (Spain); Santos, Joaquín [Departament de Física Teòrica, IFIC, Universitat de València - CSIC,Apt. Correus 22085, E-46071 València (Spain); Sanz-Cillero, Juan José [Departamento de Física Teórica I, Universidad Complutense de Madrid,E-28040 Madrid (Spain)

    2017-04-04

    The couplings of the electroweak effective theory contain information on the heavy-mass scales which are no-longer present in the low-energy Lagrangian. We build a general effective Lagrangian, implementing the electroweak chiral symmetry breaking SU(2){sub L}⊗SU(2){sub R}→SU(2){sub L+R}, which couples the known particle fields to heavier states with bosonic quantum numbers J{sup P}=0{sup ±} and 1{sup ±}. We consider colour-singlet heavy fields that are in singlet or triplet representations of the electroweak group. Integrating out these heavy scales, we analyze the pattern of low-energy couplings among the light fields which are generated by the massive states. We adopt a generic non-linear realization of the electroweak symmetry breaking with a singlet Higgs, without making any assumption about its possible doublet structure. Special attention is given to the different possible descriptions of massive spin-1 fields and the differences arising from naive implementations of these formalisms, showing their full equivalence once a proper short-distance behaviour is required.

  7. A few words about resonances in the electroweak effective Lagrangian

    Energy Technology Data Exchange (ETDEWEB)

    Rosell, Ignasi [Departamento de Ciencias Físicas, Matemáticas y de la Computación, Universidad CEU Cardenal Herrera, c/ Sant Bartomeu 55, 46115 Alfara del Patriarca, València (Spain); Pich, Antonio; Santos, Joaquín [Departament de Física Teòrica, IFIC, Universitat de València – CSIC, Apt. Correus 22085, 46071 València (Spain); Sanz-Cillero, Juan José [Departamento de Física Teórica and Instituto Física Teórica, IFT-UAM/CSIC, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2016-01-22

    Contrary to a widely spread believe, we have demonstrated that strongly coupled electroweak models including both a light Higgs-like boson and massive spin-1 resonances are not in conflict with experimental constraints on the oblique S and T parameters. We use an effective Lagrangian implementing the chiral symmetry breaking SU (2){sub L} ⊗ SU (2){sub R} → SU (2){sub L+R} that contains the Standard Model gauge bosons coupled to the electroweak Goldstones, one Higgs-like scalar state h with mass m{sub h} = 126 GeV and the lightest vector and axial-vector resonance multiplets V and A. We have considered the one-loop calculation of S and T in order to study the viability of these strongly-coupled scenarios, being short-distance constraints and dispersive relations the main ingredients of the calculation. Once we have constrained the resonance parameters, we do a first approach to the determination of the low energy constants of the electroweak effective theory at low energies (without resonances). We show this determination in the case of the purely Higgsless bosonic Lagrangian.

  8. Uses of the chiral Lagrangian at the SSC

    International Nuclear Information System (INIS)

    Dawson, S.

    1992-09-01

    In the event that the SSC does not observe any resonances such as a Higgs boson or a techni-rho meson, we would like to know if the SSC can still discover something about the nature of the electroweak symmetry breaking. In particular, we consider the question of whether there is a ''no-lose'' corollary at the SSC. We will use chiral Lagrangian techniques to address this question and analyze their utility for studying events containing W and Z gauge bosons at the SSC

  9. Chiral charge flux and electroweak baryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Funakubo, Koichi [Saga Univ. (Japan). Dept. of Physics; Kakuto, Akira; Otsuki, Shoichiro; Takenaga, Kazunori; Toyoda, Fumihiko

    1995-06-01

    By treating CP-violating interaction of the electroweak bubble wall as a perturbative term, chiral charge flux through the bubble wall is estimated. It is found that the absolute value of the flux F{sub Q} has a sharp peak at m{sub 0} - a - T with F{sub Q}/(uT{sup 3}) - 10{sup -3}(Q{sub L}-Q{sub R}){Delta}{theta}. Here m{sub 0} is the fermion mass, 1/a is the wall thickness, T is the temperature at which the bubbles are growing, u is the wall velocity, Q{sub L(R)} is the chiral charge of the relevant left (right)-handed fermion and {Delta}{theta} is the measure of CP violation. (author).

  10. Effective Chiral Lagrangians and Lattice QCD

    CERN Document Server

    Heitger, J; Wittig, H; Heitger, Jochen; Sommer, Rainer; Wittig, Hartmut

    2000-01-01

    We propose a general method to obtain accurate estimates for some of the "low-energy constants" in the one-loop effective chiral Lagrangian by means of simulating lattice QCD. In particular, the method is sensitive to those constants whose values are required to test the hypothesis of a massless up-quark. Initial tests performed in the quenched approximation confirm that good statistical precision can be achieved. As a byproduct we obtain an accurate estimate for the ratio of pseudoscalar decay constants, F_K/F_pi, in the quenched approximation, which lies 10% below the experimental result. The quantities that serve to extract the low-energy constants also allow a test of the scaling behaviour of different discretizations of QCD and a search for the effects of dynamical quarks.

  11. The complete lowest order chiral Lagrangian from a little box

    International Nuclear Information System (INIS)

    DeGrand, T.; Schaefer, S.

    2007-09-01

    We recently performed a pilot study determining the parameters of the leading order chiral Lagrangian from distributions of the eigenvalues of a quenched Dirac operator coupled to an imaginary isospin chemical potential. (orig.)

  12. Electroweak amplitudes in chiral quark models

    International Nuclear Information System (INIS)

    Fiolhais, Manuel

    2004-01-01

    After referring to some basic features of chiral models for baryons, with quarks and mesons, we describe how to construct model states representing physical baryons. We consider soliton models such as the Linear Sigma Model or the Chromodielectric Model, and bag models such as the Cloudy Bag Model. These models are solved approximately using variational approaches whose starting point is a mean-field description. We go beyond the mean-field description by introducing quantum fluctuations in the mesonic degrees of freedom. This is achieved, in a first step, by using a quantum state to represent meson clouds and, secondly, by performing an angular momentum and isospin projection from the mean-field state (actually a coherent state). Model states for baryons (nucleon, Delta, Roper) constructed in this way are used to determine several physical properties. I this seminar we paid a particular attention to the nucleon-delta electromagnetic and weak transition, presenting the model predictions for the electromagnetic and axial amplitudes

  13. Low-energy phenomenological chiral Lagrangians

    International Nuclear Information System (INIS)

    Cavopol, A.V.

    1987-01-01

    We develop a phenomenological Lagrangian that satisfies the requirements of the so called alternative schemes designed to model low energy meson phenomenology. Linear and nonlinear σ type Lagrangians and symmetry breaking schemes are used to describe pions that exhibit masses proportional to the square of the symmetry breaking term's coefficient, ε. (m π 2 ∼ 0(ε 2 )). The invariance of the theory under coordinate dependent transformations is achieved by introducing gauge fields for both linear and nonlinear Lagrangians. Finally, analogies between the minimal symmetry breaking terms in Quantum Electrodynamics and in our phenomenological lagrangians are used to generate a discussion of the quark-pion mass dependence indicated by the model

  14. The anomalous chiral Lagrangian of order p6

    International Nuclear Information System (INIS)

    Bijnens, J.; Talavera, P.

    2002-01-01

    We construct the effective chiral Lagrangian for chiral perturbation theory in the mesonic odd-intrinsic-parity sector at order p 6 . The Lagrangian contains 24 in principle measurable terms and no contact terms for the general case of N f light flavors, 23 terms for three and 5 for two flavors. In the two flavor case we need a total of 13 terms if an external singlet vector field is included. We discuss and implement the methods used to reduce to a minimal set. The infinite parts needed for renormalization are calculated and presented as well. (orig.)

  15. Hadronic interactions from effective chiral Lagrangians of quarks and gluons

    International Nuclear Information System (INIS)

    Krein, G.

    1996-06-01

    We discuss the combined used of the techniques of effective chiral field theory and the field theoretic method known as Fock-Tani representation to derive effective hadron interactions. The Fock-Tani method is based on a change of representation by means of a unitary transformation such that the composite hadrons are redescribed by elementary-particle field operators. Application of the unitary transformation on the microscopic quark-quark interaction derived from a chiral effective Lagrangian leads to chiral effective interactions describing all possible processes involving hadrons and their constituents. The formalism is illustrated by deriving the one-pion-exchange potential between the nucleons using the quark-gluon effective chiral Lagrangian of Manohar and Georgi. We also present the results of a study of the saturation properties of the nuclear matter using this formalism. (author). 9 refs., 2 figs

  16. Nonleptonic decay of charmed mesons and chiral lagrangians

    International Nuclear Information System (INIS)

    Kalinovskij, Yu.L.; Pervushin, V.N.

    1978-01-01

    Nonleptonic decays of charmed mesons in chiral theory are considered. The lagrangian of strong interaction is taken to be invariant under the SU(4)xSU(4) group. Symmetry breaking is chosen according to the (4,4sup(*))+(4sup(*),4) simplest representation of the SU(4)xSU(4) group. The lagrangian of weak interaction is taken in the ''current x current'' form and satisfies exactly the rule probabilities of decays for D and F mesons are compared with available experimental data

  17. Chiral Lagrangians and quark condensate in nuclei

    International Nuclear Information System (INIS)

    Delorme, J.; Chanfray, G.; Ericson, M.

    1996-03-01

    The evolution of density of quark condensate in nuclear medium with interacting nucleons, including the short range correlations is examined. Two chiral models are used, the linear sigma model and the non-linear one. It is shown that the quark condensate, as other observables, is independent on the variant selected. The application to physical pions excludes the linear sigma model as a credible one. The non-linear models restricted to pure s-wave pion-nucleon scattering are examined. (author)

  18. Electromagnetic couplings of the chiral perturbation theory Lagrangian from the perturbative chiral quark model

    International Nuclear Information System (INIS)

    Lyubovitskij, V.E.; Gutsche, Th.; Faessler, Amand; Mau, R. Vinh

    2002-01-01

    We apply the perturbative chiral quark model to the study of the low-energy πN interaction. Using an effective chiral Lagrangian we reproduce the Weinberg-Tomozawa result for the S-wave πN scattering lengths. After inclusion of the photon field we give predictions for the electromagnetic O(p 2 ) low-energy couplings of the chiral perturbation theory effective Lagrangian that define the electromagnetic mass shifts of nucleons and first-order (e 2 ) radiative corrections to the πN scattering amplitude. Finally, we estimate the leading isospin-breaking correction to the strong energy shift of the π - p atom in the 1s state, which is relevant for the experiment 'pionic hydrogen' at PSI

  19. Parameterization of general Z-γ-Z' mixing in an electroweak chiral theory

    International Nuclear Information System (INIS)

    Zhang Ying; Wang Qing

    2012-01-01

    A new general parameterization with eight mixing parameters among Z, γ and an extra neutral gauge boson Z ' is proposed and subjected to phenomenological analysis. We show that in addition to the conventional Weinberg angle θ W , there are seven other phenomenological parameters, G ' , ξ, η, θ 1 , θ r , r and l, for the most general Z-γ-Z ' mixings, in which parameter G ' arises due to the presence of an extra Stueckelbergtype mass coupling. Combined with the conventional Z-Z ' mass mixing angle 0', the remaining six parameters, ξ, η, θ l -θ ' , θ r - θ ' , r and l, are caused by general kinetic mixing. In all eight phenomenological parameters, θ W , G ' , ξ, η, θ 1 , θ r , r and l, we can determine the Z-Z ' mass mixing angle θ ' and the mass ratio M Z /M Z ' . The Z-γ-Z ' mixing that we discuss are based on the model-independent description of the extended electroweak chiral Lagrangian (EWCL) previously proposed by us. In addition, we show that there are eight corresponding independent theoretical coefficients in our EWCL, which are fully fixed by our eight phenomenological mixing parameters. We further find that the experimental measurability of these eight parameters does not rely on the extended neutral current for Z ' , but depends on the Z-Z ' mass ratio. (authors)

  20. The Effective Chiral Lagrangian for a Light Dynamical "Higgs Particle"

    CERN Document Server

    Alonso, R.; Merlo, L.; Rigolin, S.; Yepes, J.

    2013-01-01

    We generalize the basis of CP-even chiral effective operators describing a dynamical Higgs sector, to the case in which the Higgs-like particle is light. Gauge and gauge-Higgs operators are considered up to mass dimension five. This analysis completes the tool needed to explore at leading order the connection between linear realizations of the electroweak symmetry breaking mechanism - whose extreme case is the Standard Model - and non-linear realizations with a light Higgs-like particle present. It may also provide a model-independent guideline to explore which exotic gauge-Higgs couplings may be expected, and their relative strength to Higgsless observable amplitudes. With respect to fermions, the analysis is reduced by nature to the consideration of those flavour-conserving operators that can be written in terms of pure-gauge or gauge-Higgs ones via the equations of motion, but for the standard Yukawa-type couplings.

  1. K → ππ Electroweak penguins in the chiral limit

    International Nuclear Information System (INIS)

    Cirigliano, V.; Donoghue, J.F.; Golowich, E.; Maltman, K.

    2003-01-01

    We report on dispersive and finite energy sum rule analyses of the electroweak penguin matrix elements 2 vertical bar Q 7,8 vertical bar K 0 > in the chiral limit. We accomplish the correct perturbative matching (scale and scheme dependence) at NLO in α s , and we describe two different strategies for numerical evaluation

  2. Partition function of a chiral boson on a 2-torus from the Floreanini–Jackiw Lagrangian

    International Nuclear Information System (INIS)

    Chen, Wei-Ming; Ho, Pei-Ming; Kao, Hsien-chung; Khoo, Fech Scen; Matsuo, Yutaka

    2014-01-01

    We revisit the problem of quantizing a chiral boson on a torus. The conventional approach is to extract the partition function of a chiral boson from the path integral of a non-chiral boson. Instead we compute it directly from the chiral boson Lagrangian of Floreanini and Jackiw modified by topological terms involving an auxiliary field. A careful analysis of the gauge-fixing condition for the extra gauge symmetry reproduces the correct results for the free chiral boson, and has the advantage of being applicable to a wider class of interacting chiral boson theories

  3. An Effective Chiral Meson Lagrangian at O(p6) from the NJL Model

    International Nuclear Information System (INIS)

    Bel'kov, A.A.; Lanev, A.V.; Schaale, A.; Scherer, S.; Mainz Univ.

    1994-01-01

    In this work we present a strong chiral meson Lagrangian up to and including O(p 6 ) in the momentum expansion. It is derived from the Nambu-Jona-Lasinio (NJL) model using the heat-kernel method. Identities related to the properties of covariant derivatives of the chiral matrix U as well as field transformations have been used to predict the chiral coefficients of a minimal set of linearly independent terms. 16 refs

  4. QCD chiral Lagrangian on the lattice, strong coupling expansion, and Ward identities with Wilson fermions

    International Nuclear Information System (INIS)

    Levi, A.R.; Lubicz, V.; Rebbi, C.

    1997-01-01

    We discuss a general strategy to compute the coefficients of the QCD chiral Lagrangian using lattice QCD with Wilson fermions. This procedure requires the introduction of a lattice chiral Lagrangian as an intermediate step in the calculation. The QCD chiral Lagrangian is then obtained by expanding the lattice effective theory in increasing powers of the lattice spacing and the external momenta. In order to investigate the general structure of the lattice effective Lagrangian, we perform an analytical calculation at the leading order of the strong-coupling and large-N expansion. We find that the explicit chiral symmetry breaking, introduced on the lattice by the Wilson term, is reproduced in the effective theory by a set of additional terms, which do not have direct correspondence in the continuum chiral Lagrangian. We argue that these terms can be conveniently reabsorbed by a suitable renormalization procedure. This is shown explicitly at the leading order of the strong-coupling and large-N expansion. In fact, we find that at this order, as is known to be the case in the opposite weak-coupling limit, the vector and axial Ward identities of the continuum theory are reproduced on the lattice provided that the bare quark mass and the lattice operators are properly renormalized. copyright 1997 The American Physical Society

  5. Chiral magnetic effect in the presence of electroweak interactions as a quasiclassical phenomenon

    Science.gov (United States)

    Dvornikov, Maxim; Semikoz, Victor B.

    2018-03-01

    We elaborate the quasiclassical approach to obtain the modified chiral magnetic effect (CME) in the case when the massless charged fermions interact with electromagnetic fields and the background matter by the electroweak forces. The derivation of the anomalous current along the external magnetic field involves the study of the energy density evolution of chiral particles in parallel electric and magnetic fields. We consider both the particle acceleration by the external electric field and the contribution of the Adler anomaly. The condition of the validity of this method for the derivation of the CME is formulated. We obtain the expression for the electric current along the external magnetic field, which appears to coincide with our previous results based on the purely quantum approach. Our results are compared with the findings of other authors.

  6. Extension of the chiral perturbation theory meson Lagrangian to order p{sup 6}

    Energy Technology Data Exchange (ETDEWEB)

    Fearing, H W; Scherer, S

    1994-08-01

    We have derived the most general chirally invariant Lagrangian L{sub 6} for the meson sector at order p{sup 6}. The result provides an extension of the standard Gasser-Leutwyler Lagrangian L{sub 4} to one higher order, including as well all the odd intrinsic parity terms in the Lagrangian. The most difficult part of the derivation was developing a systematic strategy so as to get all of the independent terms and eliminate the redundant ones in an efficient way. The equation of motion terms, which are redundant in the sense that they can be transformed away via field transformations, are separated out explicitly. The resulting Lagrangian has been separated into groupings of terms contributing to increasingly more complicated processes, so that one does not have to deal with the full result when calculating p{sup 6} contributions to simple processes. (author). 53 refs., 10 tabs.

  7. Extension of the chiral perturbation theory meson Lagrangian to order p6

    International Nuclear Information System (INIS)

    Fearing, H.W.; Scherer, S.

    1996-01-01

    We have constructed the most general chirally invariant Lagrangian scrL 6 for the meson sector at order p 6 . The result provides an extension of the standard Gasser-Leutwyler Lagrangian scrL 4 to one higher order, including as well all the odd intrinsic parity terms in the Lagrangian. The most difficult part of the construction was developing a systematic strategy so as to get all of the independent terms and eliminate the redundant ones in an efficient way. The claim to have obtained the most general Lagrangian relies on this systematic construction and on the elimination of redundant quantities using relations of which we are aware, rather than on a general formal proof of either completeness or independence. The open-quote open-quote equation-of-motion close-quote close-quote terms, which are redundant in the sense that they can be transformed away via field transformations, are separated out explicitly. The resulting Lagrangian has been separated into groupings of terms contributing to increasingly more complicated processes, so that one does not have to deal with the full result when calculating p 6 contributions to simple processes. copyright 1995 The American Physical Society

  8. Effective meson lagrangian with chiral and heavy quark symmetries from quark flavor dynamics

    International Nuclear Information System (INIS)

    Ebert, D.; Feldmann, T.; Friedrich, R.; Reinhardt, H.

    1994-06-01

    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.)

  9. Phenomenological analysis of ε'/ε within an effective chiral Lagrangian approach at O(p6)

    International Nuclear Information System (INIS)

    Bel'kov, A.A.; Lanev, A.V.; Moshkin, A.A.; Bohm, G.

    1999-01-01

    We have combined a new systematic calculation of mesonic matrix elements at O(p 6 ) from an effective chiral Lagrangian approach with Wilson coefficients from [1], derived in the framework of perturbative QCD, and restricted partly by experimental data. We derive complete expressions for K → 2π amplitudes and compare the results for ε'/ε with experiment

  10. Some aspects of pion physics in the Nambu- and Jona-Lasinio model and chiral Lagrangians

    International Nuclear Information System (INIS)

    Tegen, R.

    1994-03-01

    I discuss here to what extent the original two-flavour NJL model (which has a minimal number of adjustable parameters) reproduces pion observables. In particular, the sensitivity of the recently calculated electromagnetic mass shift to these NJL parameters is pointed out and a new way to fix them is suggested. A new set of O(1/N c ) diagrams, which are the first meson loop corrections to the RPA, is presented and its effect on the pionic Goldstone mode, its electromagnetic form factor, weak decay constant, and on the constituent quark mass m is discusseed. The relation of these NJL model results to some other chiral Lagrangians is pointed out, where ever possible. The here presented higher order diagrams indicate how one could systematically generate the next-order diagrams. It is, however, questionable whether the simplistic but mathematically manageable contact interaction of the NJL model should be maintained also in these higher order diagrams. (orig.)

  11. Pseudoscalar glueball, η'-meson and its excitation in the chiral effective Lagrangian

    International Nuclear Information System (INIS)

    Nekrasov, M.L.

    1995-12-01

    A generalization of the chiral effective Lagrangian of order p 2 is obtained which describes interaction between singlet pseudoscalar states and octet of the lightest pseudoscalar states π, K, η. The singlet states were lowest quarkic state, its excitation, and the lowest gluonic state. The QCD renormalization group for the composite operators generating the singlet states, and some other QCD-inspired conditions have been taken into consideration. The way is found, which allows one to separate unambiguously the contributions of the lowest gluonic state and the single excited state. Besides, an additional condition is found which restricts the singlet-state contributions. The mixing picture of the singlet states is considered. The problem of the radiative decays of the singlet mesons is discussed. (author). 13 refs, 1 tab

  12. Chiral Lagrangian with broken scale: Testing the restoration of symmetries in astrophysics and in the laboratory

    International Nuclear Information System (INIS)

    Bonanno, Luca; Drago, Alessandro

    2009-01-01

    We study matter at high density and temperature using a chiral Lagrangian in which the breaking of scale invariance is regulated by the value of a scalar field, called dilaton [E. K. Heide, S. Rudaz, and P. J. Ellis, Nucl. Phys. A571, 713 (1994); G. W. Carter, P. J. Ellis, and S. Rudaz, Nucl. Phys. A603, 367 (1996); G. W. Carter, P. J. Ellis, and S. Rudaz, Nucl. Phys. A618, 317 (1997); G. W. Carter and P. J. Ellis, Nucl. Phys. A628, 325 (1998)]. We provide a phase diagram describing the restoration of chiral and scale symmetries. We show that chiral symmetry is restored at large temperatures, but at low temperatures it remains broken at all densities. We also show that scale invariance is more easily restored at low rather than large baryon densities. The masses of vector-mesons scale with the value of the dilaton and their values initially slightly decrease with the density but then they increase again for densities larger than ∼3ρ 0 . The pion mass increases continuously with the density and at ρ 0 and T=0 its value is ∼30 MeV larger than in the vacuum. We show that the model is compatible with the bounds stemming from astrophysics, as, e.g., the one associated with the maximum mass of a neutron star. The most striking feature of the model is a very significant softening at large densities, which manifests also as a strong reduction of the adiabatic index. Although the softening has probably no consequence for supernova explosion via the direct mechanism, it could modify the signal in gravitational waves associated with the merging of two neutron stars.

  13. Probing electroweak symmetry braking mechanism at the LHC: A guideline from power counting analysis

    International Nuclear Information System (INIS)

    He Hongjian; Virginia Polytechnic Inst. and State Univ., Blacksburg, VA; Virginia Polytechnic Inst. and State Univ., Blacksburg, VA; Kuang, Y.P.; Tsinghua Univ., Beijing, BJ; Yuan, C.P.

    1996-01-01

    We formulate the equivalence theorem as a criterion for sensitively probing the electroweak symmetry breaking mechanism, and develop a precise power counting rule for chiral Lagrangian formulated electroweak theories (CLEWT). With these we give a systematic analysis on the sensitivities of the scattering processes W ± W ± →W ± W ± and q anti q'→W ± Z to probing all possible effective bosonic operators in the CLEWT at the CERN Large Hadron Collider (LHC). (orig.)

  14. Meson-baryon coupling constants from a chiral-invariant SU(3) Lagrangian and application to NN scattering

    International Nuclear Information System (INIS)

    Stoks, V.G.J.

    1997-01-01

    We present a chiral-invariant meson-baryon Lagrangian which describes the interactions of the baryon octet with the lowest-mass meson nonets. The nonlinear realization of the chiral symmetry generates pair-meson interaction vertices. The corresponding pair-meson coupling constants can all be expressed in terms of the meson-nucleon-nucleon pseudovector, scalar, and vector coupling constants, and their corresponding F/(F+D) ratios, and for which empirical estimates are given. We show that it is possible to construct an NN potential of reasonable quality satisfying these theoretical and empirical constraints. (orig.)

  15. Chiral Lagrangian calculation of nucleon branching ratios in the supersymmetric SU(5) model

    International Nuclear Information System (INIS)

    Chadha, S.; Daniel, M.

    1983-12-01

    The branching ratios are calculated for the two body nucleon decay modes involving pseudoscalars in the minimal SU(5) supersymmetric model with three generations using the techniques of chiral dynamics. (author)

  16. Application of chiral resonance Lagrangian theories to the muon g-2

    Energy Technology Data Exchange (ETDEWEB)

    Jegerlehner, Fred [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2013-12-15

    We think that phenomenological resonance Lagrangian models, constrained by global fits from low energy hadron reaction data, can help to improve muon g-2 predictions. The main issue are those contributions which cannot be calculated by perturbative means: the hadronic vacuum polarization (HVP) effects and the hadronic light-by-light (HLbL) scattering contribution. I review recent progress in the evaluation of the HVP contribution within the broken Hidden Local Symmetry (HLS) framework, worked out in collaboration with M. Benayoun, P. David and L. Del-Buono. Our HLS driven estimate reads a{sub {mu}}{sup LO} {sup had} = (688.60{+-}4.24) . 10{sup -10} and we find a{sub {mu}}{sup the} = (11659177.65{+-}5.76) . 10{sup -10}.

  17. Application of chiral resonance Lagrangian theories to the muon g-2

    International Nuclear Information System (INIS)

    Jegerlehner, Fred

    2013-12-01

    We think that phenomenological resonance Lagrangian models, constrained by global fits from low energy hadron reaction data, can help to improve muon g-2 predictions. The main issue are those contributions which cannot be calculated by perturbative means: the hadronic vacuum polarization (HVP) effects and the hadronic light-by-light (HLbL) scattering contribution. I review recent progress in the evaluation of the HVP contribution within the broken Hidden Local Symmetry (HLS) framework, worked out in collaboration with M. Benayoun, P. David and L. Del-Buono. Our HLS driven estimate reads a μ LO had = (688.60±4.24) . 10 -10 and we find a μ the = (11659177.65±5.76) . 10 -10 .

  18. K → πι+ι- decays in the effective chiral lagrangian of the standard model

    International Nuclear Information System (INIS)

    Pich, A.; Rafael, E. de; Ecker, G.

    1986-01-01

    The decay amplitudes of K → πι + ι - transitions (ι = e or μ) are calculated in chiral perturbation theory to lowest non-trivial order. This includes one-loop contributions as well as contributions from all possible tree level counterterms to the corresponding order in momenta and meson masses. Only one combination of counterterm coupling constants appearing in the decay amplitudes remains unknown. Two possible solutions for this constant are found from a comparison with the experimentally known K + → π + e + e - decay rate. Predictions are then obtained for the rates of K + → π + μ + μ - , K S o → π o e + e - and K S o → π o μ + μ - decays as well as for the corresponding spectra in the invariant mass of the lepton pair. The CP-violating transition K L o → π o 'γ' → π o ι + ι - is also discussed. (Author)

  19. The nucleon-nucleon interaction from a realistic pseudoscalar-vector chiral lagrangian

    International Nuclear Information System (INIS)

    Kaiser, N.; Meissner, U.G.; Massachusetts Inst. of Tech., Cambridge

    1990-01-01

    We investigate the static nucleon-nucleon potential in the framework of a non-linear chiral meson theory. The model includes pions as well as the vector mesons ρ and ω. All parameters are fixed in the meson sector and predictions about the nucleon-nucleon interaction follow without adjusting any parameters. We use an S-matrix approach to calculate correlated two-pion exchange between two solitons. The most prominent feature of this two-pion exchange is that it leads very natural to attraction in the scalar-isoscalar channel. We also discuss the effect of πp correlations on the central potential, and present the spectral function related to the correlated two-pion exchange. Furthermore, we study the form factors of the nucleon sources related to the two-pion exchange and find that they are of dipole type with typical cutoff scales Λ D ≅ 700 MeV. We also discuss the destructive interference of π- and ρ-exchange in the isovector tensor potential. Altogether, we present a unified treatment of meson exchange phenomenology based on a serious model of the nucleon. Finally, we point out the limitations of the model and discuss some further applications. (orig.)

  20. Simplifications in lagrangian BV quantization exemplified by the anomalies of chiral W3 gravity

    International Nuclear Information System (INIS)

    Vandoren, S.; Proeyen, A. van

    1994-01-01

    The Batalin-Vilkovisky (BV) formalism is a useful framework to study gauge theories. We summarize a simple procedure to find a gauge-fixed action in this language and a way to obtain one-loop anomalies. Calculations involving the antifields can be greatly simplified by using a theorem on the antibracket cohomology. The latter is based on properties of a ''Koszul-Tate differential'', namely its acyclicity and nilpotency. We present a new proof for this acyclicity, respecting locality and covariance of the theory. This theorem then implies that consistent higher ghost terms in various expressions exist, and it avoids tedious calculations. This is illustrated in chiral W 3 gravity. We compute the one-loop anomaly without terms of negative ghost number. Then the mentioned theorem and the consistency condition imply that the full anomaly is determined up to local counterterms. Finally we show how to implement background charges into the BV language in order to cancel the anomaly with the appropriate counterterms. Again we use the theorem to simplify the calculations, which agree with previous results. (orig.)

  1. Electroweak interactions on the lattice

    International Nuclear Information System (INIS)

    Kieu, T.D.

    1994-07-01

    It is shown that the lattice fermion doubling phenomenon is connected to the chiral anomaly which is unique to the electroweak interactions. The chiral anomaly is the breaking of chiral gauge symmetry at the quantum level due to the quantum fluctuations. Such breaking, however, is undesirable and to be avoided. The preservation of gauge symmetry imposes stringent constraints on acceptable chiral gauge theory. It is argued that the constraints are unnecessary because the conventional quantization of chiral gauge theory has missed out some crucial contributions of the chiral interactions. The corrected quantization yields consistent theory in which there is no gauge anomaly and in which various mass terms can be introduced with neither the loss of gauge invariance nor the need for the Higgs mechanism. The new quantization also provide a solution to the difficulty of how to model the electroweak interactions on the lattice. 9 refs. 1 fig

  2. Fundamental composite electroweak dynamics

    DEFF Research Database (Denmark)

    Arbey, Alexandre; Cacciapaglia, Giacomo; Cai, Haiying

    2017-01-01

    Using the recent joint results from the ATLAS and CMS collaborations on the Higgs boson, we determine the current status of composite electroweak dynamics models based on the expected scalar sector. Our analysis can be used as a minimal template for a wider class of models between the two limitin...... space at the effective Lagrangian level. We show that a wide class of models of fundamental composite electroweak dynamics are still compatible with the present constraints. The results are relevant for the ongoing and future searches at the Large Hadron Collider....

  3. Electroweak Physics

    OpenAIRE

    Erler, Jens; Langacker, Paul

    2008-01-01

    The results of high precision weak neutral current (WNC), Z-pole, and high energy collider electroweak experiments have been the primary prediction and test of electroweak unification. The electroweak program is briefly reviewed from a historical perspective. The current status and the implications for the standard model and beyond are discussed.

  4. Sigma decomposition: the CP-odd Lagrangian

    Energy Technology Data Exchange (ETDEWEB)

    Hierro, I.M. [Dipartimento di Fisica “G. Galilei”, Università di Padova and INFN, Sezione di Padova,Via Marzolo 8, I-35131 Padua (Italy); Merlo, L. [Instituto de Física Teórica, IFT-UAM/CSIC, Universidad Autónoma de Madrid,Cantoblanco, 28049, Madrid (Spain); Rigolin, S. [Dipartimento di Fisica “G. Galilei”, Università di Padova and INFN, Sezione di Padova,Via Marzolo 8, I-35131 Padua (Italy)

    2016-04-04

    In Alonso et al., http://dx.doi.org/10.1007/JHEP12(2014)034, the CP-even sector of the effective chiral Lagrangian for a generic composite Higgs model with a symmetric coset has been constructed, up to four momenta. In this paper, the CP-odd couplings are studied within the same context. If only the Standard Model bosonic sources of custodial symmetry breaking are considered, then at most six independent operators form a basis. One of them is the weak-θ term linked to non-perturbative sources of CP violation, while the others describe CP-odd perturbative couplings between the Standard Model gauge bosons and an Higgs-like scalar belonging to the Goldstone boson sector. The procedure is then applied to three distinct exemplifying frameworks: the original SU(5)/SO(5) Georgi-Kaplan model, the minimal custodial-preserving SO(5)/SO(4) model and the minimal SU(3)/(SU(2)×U(1)) model, which intrinsically breaks custodial symmetry. Moreover, the projection of the high-energy electroweak effective theory to the low-energy chiral effective Lagrangian for a dynamical Higgs is performed, uncovering strong relations between the operator coefficients and pinpointing the differences with the elementary Higgs scenario.

  5. Signals of composite electroweak-neutral Dark Matter: LHC/direct detection interplay

    International Nuclear Information System (INIS)

    Barbieri, Riccardo; Rychkov, Slava; Torre, Riccardo

    2010-01-01

    In a strong-coupling picture of ElectroWeak Symmetry Breaking, a composite electroweak-neutral state in the TeV mass range, carrying a global (quasi-)conserved charge, makes a plausible Dark Matter (DM) candidate, with the ongoing direct DM searches being precisely sensitive to the expected signals. To exploit the crucial interplay between direct DM searches and the LHC, we consider a composite iso-singlet vector V, mixed with the hypercharge gauge field, as the essential mediator of the interaction between the DM particle and the nucleus. Based on a suitable effective chiral Lagrangian, we give the expected properties and production rates of V, showing its possible discovery at the maximal LHC energy with about 100 fb -1 of integrated luminosity.

  6. Critical constraints on chiral hierarchies

    International Nuclear Information System (INIS)

    Chivukula, R.S.; Golden, M.; Simmons, E.H.

    1993-01-01

    Critical dynamics constrains models of dynamical electroweak symmetry breaking in which the scale of high-energy physics is far above 1 TeV. A big hierarchy requires the high-energy theory to have a second-order chiral phase transition, near which the theory is described by a low-energy effective Lagrangian with composite ''Higgs'' scalars. As scalar theories with more than one Φ 4 coupling can have a Coleman-Weinberg instability and a first-order transition, such dynamical EWSB models cannot always support a large hierarchy. If the large-N c Nambu--Jona-Lasinio model is a good approximation to the top-condensate and strong extended technicolor models, they will not produce acceptable EWSB

  7. Current density functional theory in a continuum and lattice Lagrangians: Application to spontaneously broken chiral ground states

    International Nuclear Information System (INIS)

    Rasolt, M.; Vignale, G.

    1992-03-01

    We formulate the current-density functional theory for systems in arbitrarily strong magnetic fields. A set of self-consistent equations comparable to the Kohn-Sham equations for ordinary density functional theory is derived, and proved to be gauge-invariant and to satisfy the continuity equation. These equations of Vignale and Rasolt involve the gauge field corresponding to the external magnetic field as well as a new gauge field generated entirely from the many-body interactions. We next extend this gauge theory (following Rasolt and Vignale) to a lattice Lagrangian believed to be appropriate to a tight-binding Hamiltonian in the presence of an external magnetic field. We finally examine the nature of the ground state of a strongly nonuniform electron gas in the presence of this many-body self-induced gauge field

  8. Siegel's chiral boson and the chiral Schwinger model

    International Nuclear Information System (INIS)

    Berger, T.

    1992-01-01

    In this paper Siegel's proposal for a Lagrangian formulation of a chiral boson is analyzed by applying recent results on 2d chiral quantum gravity. A model is derived whose solution consists of a massive scalar and two massless chiral scalars. Therefore it is a minimally bosonized two-fermion chiral Schwinger model

  9. Electroweak Physics

    OpenAIRE

    Hollik, W.

    2005-01-01

    The status of precision electroweak measurements as of summer 2002 is reviewed. The recent results on the anomalous magnetic moment of the muon and on neutrino-nucleon scattering are discussed. Precision results on the electroweak interaction obtained by the experiments at the SLC, LEP and TEVATRON colliders are presented. The experimental results are compared with the predictions of the minimal Standard Model and are used to constrain its parameters, including the mass of the Higgs boson. Th...

  10. Electroweak baryogenesis

    International Nuclear Information System (INIS)

    Trodden, Mark

    1999-01-01

    Contrary to naive cosmological expectations, all evidence suggests that the universe contains an abundance of matter over antimatter. This article reviews the currently popular scenario in which testable physics, present in the standard model of electroweak interactions and its modest extensions, is responsible for this fundamental cosmological datum. A pedagogical explanation of the motivations and physics behind electroweak baryogenesis is provided, and analytical approaches, numerical studies, up to date developments, and open questions in the field are also discussed. (c) 1999 The American Physical Society

  11. Electroweak corrections

    International Nuclear Information System (INIS)

    Beenakker, W.J.P.

    1989-01-01

    The prospect of high accuracy measurements investigating the weak interactions, which are expected to take place at the electron-positron storage ring LEP at CERN and the linear collider SCL at SLAC, offers the possibility to study also the weak quantum effects. In order to distinguish if the measured weak quantum effects lie within the margins set by the standard model and those bearing traces of new physics one had to go beyond the lowest order and also include electroweak radiative corrections (EWRC) in theoretical calculations. These higher-order corrections also can offer the possibility of getting information about two particles present in the Glashow-Salam-Weinberg model (GSW), but not discovered up till now, the top quark and the Higgs boson. In ch. 2 the GSW standard model of electroweak interactions is described. In ch. 3 some special techniques are described for determination of integrals which are responsible for numerical instabilities caused by large canceling terms encountered in the calculation of EWRC effects, and methods necessary to get hold of the extensive algebra typical for EWRC. In ch. 4 various aspects related to EWRC effects are discussed, in particular the dependence of the unknown model parameters which are the masses of the top quark and the Higgs boson. The processes which are discussed are production of heavy fermions from electron-positron annihilation and those of the fermionic decay of the Z gauge boson. (H.W.). 106 refs.; 30 figs.; 6 tabs.; schemes

  12. Electroweak interactions

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1980-10-01

    A point of view of the electroweak interaction is presented. It begins phenomenologically and moves in stages toward the conventional gauge theory formalism containing elementary scalar Higgs-fields and then beyond. The purpose in so doing is that the success of the standard SU(2) x U(1) theory in accounting for low energy phenomena need not automatically imply success at high energies. It is deemed unlikely by most theorists that the predicted W +- or Z 0 does not exist or does not have the mass and/or couplings anticipated in the standard model. However, the odds that the standard predictions will work are not 100%. Therefore there is some reason to look at the subject as one would were he forced by a wrong experimental outcome - to go back to fundamentals and ascertain what is the minimal amount of theory necessary to account for the data

  13. Electroweak form factors of the Skyrmion

    International Nuclear Information System (INIS)

    Braaten, E.; Sze-Man Tse; Willcox, C.

    1986-01-01

    The electroweak form factors of baryons are studied in the semiclassical approximation to the Skyrme model. General expressions for the form factors are given for arbitrary choices of the Skyrme-model Lagrangian. They are applied to the original two-parameter Skyrme model to compute the electric, magnetic, and axial-vector form factors of the nucleon and the electromagnetic nucleon-Δ transition form factors. The dependence of the form factors on the momentum transfer is compared with phenomenological dipole parametrizations

  14. Oblique S and T constraints on electroweak strongly-coupled models with a light Higgs

    Energy Technology Data Exchange (ETDEWEB)

    Pich, A. [Departament de Física Teòrica, IFIC, Universitat de València - CSIC,Apt. Correus 22085, E-46071 València (Spain); Rosell, I. [Departament de Física Teòrica, IFIC, Universitat de València - CSIC,Apt. Correus 22085, E-46071 València (Spain); Departamento de Ciencias Físicas, Matemáticas y de la Computación,Universidad CEU Cardenal Herrera,c/ Sant Bartomeu 55, E-46115 Alfara del Patriarca, València (Spain); Sanz-Ciller, J.J. [Departamento de Física Teórica, Instituto de Física Teórica,Universidad Autónoma de Madrid - CSIC,c/ Nicolás Cabrera 13-15, E-28049 Cantoblanco, Madrid (Spain)

    2014-01-28

    Using a general effective Lagrangian implementing the chiral symmetry breaking SU(2){sub L}⊗SU(2){sub R}→SU(2){sub L+R}, we present a one-loop calculation of the oblique S and T parameters within electroweak strongly-coupled models with a light scalar. Imposing a proper ultraviolet behaviour, we determine S and T at next-to-leading order in terms of a few resonance parameters. The constraints from the global fit to electroweak precision data force the massive vector and axial-vector states to be heavy, with masses above the TeV scale, and suggest that the W{sup +}W{sup −} and ZZ couplings of the Higgs-like scalar should be close to the Standard Model value. Our findings are generic, since they only rely on soft requirements on the short-distance properties of the underlying strongly-coupled theory, which are widely satisfied in more specific scenarios.

  15. Lattice regularized chiral perturbation theory

    International Nuclear Information System (INIS)

    Borasoy, Bugra; Lewis, Randy; Ouimet, Pierre-Philippe A.

    2004-01-01

    Chiral perturbation theory can be defined and regularized on a spacetime lattice. A few motivations are discussed here, and an explicit lattice Lagrangian is reviewed. A particular aspect of the connection between lattice chiral perturbation theory and lattice QCD is explored through a study of the Wess-Zumino-Witten term

  16. Equivalent Lagrangians

    International Nuclear Information System (INIS)

    Hojman, S.

    1982-01-01

    We present a review of the inverse problem of the Calculus of Variations, emphasizing the ambiguities which appear due to the existence of equivalent Lagrangians for a given classical system. In particular, we analyze the properties of equivalent Lagrangians in the multidimensional case, we study the conditions for the existence of a variational principle for (second as well as first order) equations of motion and their solutions, we consider the inverse problem of the Calculus of Variations for singular systems, we state the ambiguities which emerge in the relationship between symmetries and conserved quantities in the case of equivalent Lagrangians, we discuss the problems which appear in trying to quantize classical systems which have different equivalent Lagrangians, we describe the situation which arises in the study of equivalent Lagrangians in field theory and finally, we present some unsolved problems and discussion topics related to the content of this article. (author)

  17. Pion polarizability in a chiral quark model

    International Nuclear Information System (INIS)

    Volkov, M.K.; Ehbert, D.

    1980-01-01

    The pion polarizability is calculated in a chiral meson-quark model at the one-loop level. The results are in complete agreement with earlier ones obtained within a chiral meson-baryon theory. A critical discussion of a recent paper by Lanta and Tarrach is given. The results of the paper give evidence to the nonlinear chiral Lagrangian favour

  18. Quenched Chiral Perturbation Theory to one loop

    NARCIS (Netherlands)

    Colangelo, G.; Pallante, E.

    The divergences of the generating functional of quenched Chiral Perturbation theory (qCHPT) to one loop are computed in closed form. We show how the quenched chiral logarithms can be reabsorbed in the renormalization of the B0 parameter of the leading order Lagrangian. Finally, we do the chiral

  19. New remarks on chiral bosonization

    International Nuclear Information System (INIS)

    Souza Dutra, A. de

    1992-01-01

    We discuss a certain duality between the constraints appearing in ordinary Lagrangian density and its first order counterpart for the gauged Siegel chiral boson. It is demonstrated the equivalence, at the classical level, of the two versions of the gauged Siegel chiral boson to its corresponding gauged Floreanini-Jackiw chiral bosons. It is also argued that the most general constrained Lagrangian density, that leads to a bosonic field obeying a first order differential equation of motion and preserve simultaneously Lorentz invariance, is just the Floreanini-Jackiw one. (author)

  20. Phenomenological Lagrangians

    International Nuclear Information System (INIS)

    Weinberg, S.

    1979-01-01

    The author presents an argument that phenomenological Lagrangians can be used not only to reproduce the soft pion results of current algebra, but also to justify these results, without any use of operator algebra, and shows how phenomenological Lagrangians can be used to calculate corrections to the leading soft pion results to any desired order in external momenta. The renormalization group is used to elucidate the structure of these corrections. Corrections due to the finite mass of the pion are treated and speculations are made about another possible application of phenomenological Lagrangians. (Auth.)

  1. Electroweak monopoles and the electroweak phase transition

    Energy Technology Data Exchange (ETDEWEB)

    Arunasalam, Suntharan; Kobakhidze, Archil [The University of Sydney, ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, Sydney, NSW (Australia)

    2017-07-15

    We consider an isolated electroweak monopole solution within the Standard Model with a nonlinear Born-Infeld extension of the hypercharge gauge field. Monopole (and dyon) solutions in such an extension are regular and their masses are predicted to be proportional to the Born-Infeld mass parameter. We argue that cosmological production of electroweak monopoles may delay the electroweak phase transition and make it more strongly first order for monopole masses M >or similar 9.3 . 10{sup 3} TeV, while the nucleosynthesis constraints on the abundance of relic monopoles impose the bound M electroweak phase transition. (orig.)

  2. Effective Lagrangians for quantum many-body systems

    Czech Academy of Sciences Publication Activity Database

    Andersen, J. O.; Brauner, Tomáš; Hofmann, C. P.; Vuorinen, A.

    2014-01-01

    Roč. 2014, č. 8 (2014), 088 ISSN 1029-8479 Institutional support: RVO:61389005 Keywords : spontaneous symmetry breaking * chiral lagrangian s * global symmetries Subject RIV: BE - Theoretical Physics Impact factor: 6.111, year: 2014

  3. An electroweak basis for neutrinoless double β decay

    Science.gov (United States)

    Graesser, Michael L.

    2017-08-01

    A discovery of neutrinoless double- β decay would be profound, providing the first direct experimental evidence of Δ L = 2 lepton number violating processes. While a natural explanation is provided by an effective Majorana neutrino mass, other new physics interpretations should be carefully evaluated. At low-energies such new physics could man-ifest itself in the form of color and SU(2) L × U(1) Y invariant higher dimension operators. Here we determine a complete set of electroweak invariant dimension-9 operators, and our analysis supersedes those that only impose U(1) em invariance. Imposing electroweak invariance implies: 1) a significantly reduced set of leading order operators compared to only imposing U(1) em invariance; and 2) other collider signatures. Prior to imposing electroweak invariance we find a minimal basis of 24 dimension-9 operators, which is reduced to 11 electroweak invariant operators at leading order in the expansion in the Higgs vacuum expectation value. We set up a systematic analysis of the hadronic realization of the 4-quark operators using chiral perturbation theory, and apply it to determine which of these operators have long-distance pion enhancements at leading order in the chiral expansion. We also find at dimension-11 and dimension-13 the electroweak invariant operators that after electroweak symmetry breaking produce the remaining Δ L = 2 operators that would appear at dimension-9 if only U(1) em is imposed.

  4. Integrating out resonances in strongly-coupled electroweak scenarios

    Directory of Open Access Journals (Sweden)

    Rosell Ignasi

    2017-01-01

    Full Text Available Accepting that there is a mass gap above the electroweak scale, the Electroweak Effective Theory (EWET is an appropriate tool to describe this situation. Since the EWET couplings contain information on the unknown high-energy dynamics, we consider a generic strongly-coupled scenario of electroweak symmetry breaking, where the known particle fields are coupled to heavier states. Then, and by integrating out these heavy fields, we study the tracks of the lightest resonances into the couplings. The determination of the low-energy couplings (LECs in terms of resonance parameters can be made more precise by considering a proper short-distance behaviour on the Lagrangian with heavy states, since the number of resonance couplings is then reduced. Notice that we adopt a generic non-linear realization of the electroweak symmetry breaking with a singlet Higgs.

  5. Electroweak interactions in nuclei

    International Nuclear Information System (INIS)

    Henley, E.M.

    1984-06-01

    Topics include: introduction to electroweak theory; the Weinberg-Salam theory for leptons; the Weinberg-Salam theory for hadrons-the GIM mechanism; electron scattering as a probe of the electroweak interaction (observation of PV, the weak interaction for nucleons, and parity violation in atoms); and time reversed invariance and electric dipole moments of nucleons, nuclei, and atoms. 52 references

  6. Semilocal and electroweak strings

    NARCIS (Netherlands)

    Achucarro, A; Vachaspati, T

    We review a class of non-topological defects in the standard electroweak model, and their implications. Starting with the semilocal string, which provides a counterexample to many well-known properties of topological vortices, we discuss electroweak strings and their stability with and without

  7. Gravitationally coupled electroweak monopole

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Y.M., E-mail: ymcho7@konkuk.ac.kr [Administration Building 310-4, Konkuk University, Seoul 143-701 (Korea, Republic of); School of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Kimm, Kyoungtae [Faculty of Liberal Education, Seoul National University, Seoul 151-747 (Korea, Republic of); Yoon, J.H. [Department of Physics, College of Natural Sciences, Konkuk University, Seoul 143-701 (Korea, Republic of)

    2016-10-10

    We present a family of gravitationally coupled electroweak monopole solutions in Einstein–Weinberg–Salam theory. Our result confirms the existence of globally regular gravitating electroweak monopole which changes to the magnetically charged black hole as the Higgs vacuum value approaches to the Planck scale. Moreover, our solutions could provide a more accurate description of the monopole stars and magnetically charged black holes.

  8. Electroweak Results from CMS

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    We present recent CMS measurements on electroweak boson production including single, double, and triple boson final states. Electroweak processes span many orders of magnitude in production cross section. Measurements of high-rate processes provide stringent tests of the standard model. In addition, rare triboson proceses and final states produced through vector boson scattering are newly accessible with the large integrated luminosity provided by the LHC. If new physics lies just beyond the reach of the LHC, its effects may manifest as enhancements to the high energy kinematics in mulitboson production. We present limits on new physics signatures using an effective field theory which models these modifications as modifications of electroweak gauge couplings. Since electroweak measurements will continue to benefit from the increasing integrated luminosity provided by the LHC, the future prospects of electroweak physics are discussed.

  9. Study of electroweak gauge boson scattering in the WZ channel with the ATLAS detector at the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Socher, Felix

    2016-07-15

    high centre-of-mass energies and luminosities to study these processes successfully. The Large Hadron Collider (LHC) at CERN is a circular proton-proton collider equipped to supply a suitable environment for such studies with the colliding protons being the sources for the scattering of massive electroweak gauge bosons. The dataset collected in 2012 by the ATLAS detector at the LHC with a total luminosity of 20.3 fb{sup -1} and a centre-of-mass energy of 8 TeV is analysed in this work. The elastic scattering process WZ → WZ is studied due to its clean signal properties. It provides a complementary measurement to W{sup ±}W{sup ±}→W{sup ±}W{sup ±} which reported the first significant evidence for massive electroweak gauge boson scattering. Given the current data, WZ→WZ scattering is not observed with large significantly. A cross section upper limit of 2.5 fb at 95% confidence level is measured, compatible with the cross section of 0.54 fb predicted by the Standard Model. In addition, distributions for several observables sensitive to electroweak gauge boson scattering are unfolded, removing effects caused by the measuring process. Physics beyond the Standard Model is probed in the framework of the electroweak chiral Lagrangian which expresses the size of effects from new physics in terms of strength parameters. The two strength parameters influencing the quartic gauge couplings are constrained to -0.44<α{sub 4}<0.49 and -0.49<α{sub 5}<0.47 thus limiting the possible size of new physics contributions.

  10. Study of electroweak gauge boson scattering in the WZ channel with the ATLAS detector at the Large Hadron Collider

    International Nuclear Information System (INIS)

    Socher, Felix

    2016-01-01

    -of-mass energies and luminosities to study these processes successfully. The Large Hadron Collider (LHC) at CERN is a circular proton-proton collider equipped to supply a suitable environment for such studies with the colliding protons being the sources for the scattering of massive electroweak gauge bosons. The dataset collected in 2012 by the ATLAS detector at the LHC with a total luminosity of 20.3 fb"-"1 and a centre-of-mass energy of 8 TeV is analysed in this work. The elastic scattering process WZ → WZ is studied due to its clean signal properties. It provides a complementary measurement to W"±W"±→W"±W"± which reported the first significant evidence for massive electroweak gauge boson scattering. Given the current data, WZ→WZ scattering is not observed with large significantly. A cross section upper limit of 2.5 fb at 95% confidence level is measured, compatible with the cross section of 0.54 fb predicted by the Standard Model. In addition, distributions for several observables sensitive to electroweak gauge boson scattering are unfolded, removing effects caused by the measuring process. Physics beyond the Standard Model is probed in the framework of the electroweak chiral Lagrangian which expresses the size of effects from new physics in terms of strength parameters. The two strength parameters influencing the quartic gauge couplings are constrained to -0.44<α_4<0.49 and -0.49<α_5<0.47 thus limiting the possible size of new physics contributions.

  11. Precision electroweak measurements

    International Nuclear Information System (INIS)

    Demarteau, M.

    1996-11-01

    Recent electroweak precision measurements fro e + e - and p anti p colliders are presented. Some emphasis is placed on the recent developments in the heavy flavor sector. The measurements are compared to predictions from the Standard Model of electroweak interactions. All results are found to be consistent with the Standard Model. The indirect constraint on the top quark mass from all measurements is in excellent agreement with the direct m t measurements. Using the world's electroweak data in conjunction with the current measurement of the top quark mass, the constraints on the Higgs' mass are discussed

  12. The electroweak theory

    International Nuclear Information System (INIS)

    Chris Quigg

    2001-01-01

    After a short essay on the current state of particle physics, the author reviews the antecedents of the modern picture of the weak and electromagnetic interactions and then undertakes a brief survey of the SU(2) L (circle-times) U(1) Y electroweak theory. The authors reviews the features of electroweak phenomenology at tree level and beyond, presents an introduction to the Higgs boson and the 1-TeV scale, and examines arguments for enlarging the electroweak theory. The author concludes with a brief look at low-scale gravity

  13. Chiral perturbation theory

    International Nuclear Information System (INIS)

    Ecker, G.

    1996-06-01

    After a general introduction to the structure of effective field theories, the main ingredients of chiral perturbation theory are reviewed. Applications include the light quark mass ratios and pion-pion scattering to two-loop accuracy. In the pion-nucleon system, the linear σ model is contrasted with chiral perturbation theory. The heavy-nucleon expansion is used to construct the effective pion-nucleon Lagrangian to third order in the low-energy expansion, with applications to nucleon Compton scattering. (author)

  14. Effective lagrangian for strong interactions

    International Nuclear Information System (INIS)

    Jain, P.

    1988-01-01

    We attempt to construct a realistic phenomenological Lagrangian in order to describe strong interactions. This is in general a very complicated problem and we shall explore its various aspects. We first include the vector mesons by writing down the most general chiral invariant terms proportional to the Levi-Civita symbol ε μναβ . These terms involve three unknown coefficients, which are calculated by using the experimental results of strong interaction processes. We then calculate the static nucleon properties by finding the solitonic excitations of this model. The results turn out to be, as is also the case for most other vector-pseudoscalar Lagrangians, better than the Skyrme model but are still somewhat different from the experiments. Another aspect that we shall study is the incorporation of scale anomaly of QCD into the Skyrme model. We thus introduce a scalar glueball in our Lagrangian. Here we find an interesting result that the effective glue field dynamically forms a bag for the soliton. Depending on the values of the parameters, we get either a deep bag or a shallow bag. However by including the scalar meson, we find that to get realistic scalar sector we must have the shallow bag. Finally we show some intriguing connections between the chiral quark model, in which the nucleon is described as a solitonic excitation, and the ordinary potential binding quark model

  15. Electroweak form factors

    International Nuclear Information System (INIS)

    Singh, S.K.

    2002-01-01

    The present status of electroweak nucleon form factors and the N - Δ transition form factors is reviewed. Particularly the determination of dipole mass M A in the axial vector form factor is discussed

  16. Electroweak evolution equations

    International Nuclear Information System (INIS)

    Ciafaloni, Paolo; Comelli, Denis

    2005-01-01

    Enlarging a previous analysis, where only fermions and transverse gauge bosons were taken into account, we write down infrared-collinear evolution equations for the Standard Model of electroweak interactions computing the full set of splitting functions. Due to the presence of double logs which are characteristic of electroweak interactions (Bloch-Nordsieck violation), new infrared singular splitting functions have to be introduced. We also include corrections related to the third generation Yukawa couplings

  17. Electroweak penguins at LHCb

    CERN Document Server

    AUTHOR|(CDS)2073177

    2016-01-01

    Electroweak penguin decays are flavour-changing neutral current processes, and are highly suppressed in the Stan- dard Model. They can only proceed via loop diagrams. Such decays may receive contributions from New Physics and change their decay behaviours like decay rate and angular distribution. Studying the properties of these decays thus provides a powerful method to probe for New Physics. In this contribution the most recent LHCb results on electroweak penguin decays are reported.

  18. Electroweak penguins at LHCb

    Science.gov (United States)

    He, Jibo; LHCb Collaboration

    2016-04-01

    Electroweak penguin decays are flavour-changing neutral current processes, and are highly suppressed in the Standard Model. They can only proceed via loop diagrams. Such decays may receive contributions from New Physics and change their decay behaviours like decay rate and angular distribution. Studying the properties of these decays thus provides a powerful method to probe for New Physics. In this contribution the most recent LHCb results on electroweak penguin decays are reported.

  19. Massive states in chiral perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    Mallik, S [Saha Inst. of Nuclear Physics, Calcutta (India)

    1995-08-01

    It is shown that the chiral nonanalytic terms generated by {Delta}{sub 33} resonance in the nucleon self-energy is reproduced in chiral perturbation theory by perturbing appropriate local operators contained in the pion-nucleon effective Lagrangian itself. (orig.)

  20. Vector boson scattering and electroweak production of two like-charge W bosons and two jets at the current and future ATLAS detector

    International Nuclear Information System (INIS)

    Schnoor, Ulrike

    2015-01-01

    fiducial W ± W ± jj-EW =1.3±0.4(stat.)±0.2(syst. ) fb in a fiducial phase space region selected to enhance the contribution from WW scattering. The measurement is compatible with the Standard Model prediction of σ fiducial W ± W ± jj-EW =0.95±0.06 fb. Based on this measurement, limits on anomalous quartic gauge couplings are derived. The effect of anomalous quartic gauge couplings is simulated within the framework of an effective chiral Lagrangian unitarized with the K-matrix method. The limits for the anomalous coupling parameters α 4 and α 5 are found to be -0.14<α 4 <0.16 and -0.23<α 5 <0.24 at 95 % confidence level. Furthermore, the prospects for the measurement of the electroweak production of two same-charge W bosons and two jets within the Standard Model and with additional doubly charged resonances after the upgrade of the ATLAS detector and the LHC are investigated. For a high-luminosity LHC with a center-of-mass energy of √(s)=14 TeV, the significance of the measurement with an integrated luminosity of 3000 fb -1 is estimated to be 18.7 standard deviations. It can be improved by 30 % by extending the inner tracking detector of the ATLAS experiment up to an absolute pseudorapidity of vertical stroke η vertical stroke =4.0.

  1. State of electroweak interactions

    International Nuclear Information System (INIS)

    Lane, K.

    1984-01-01

    I assess what we know and what we do not know about the electroweak interactions. In particular, I argue that existing data on the electroweak parameters rho, sin 2 theta/sub w/ and G/sub F/ and on the recently discovered W +- and Z 0 allow us reasonably to conclude that: (1) the W +- and Z 0 truly are the elementary massive gauge bosons of SU(2) x U(1) and not the composite bosons of a new strong interaction, and (2) the electroweak scalar sector consists of weak doublets only. The most important thing we do not know is everything else about the electroweak scalar sector. In the hope of soon shedding light on this issue, a new method of searching for electroweak scalars in existing p-barp colliders is proposed. The basis of this method is that the branching ratio of W +- to decay to a charged plus a neutral scalar (expected in non-minimal SU(2) x U(1) models) can be as large as 1-2%, with detectable rates up to scalar masses of approx.35 GeV

  2. Lagrangian optics

    CERN Document Server

    Lakshminarayanan, Vasudevan; Thyagarajan, K

    2002-01-01

    Ingeometrical optics, light propagation is analyzed in terms of light rays which define the path of propagation of light energy in the limitofthe optical wavelength tending to zero. Many features oflight propagation can be analyzed in terms ofrays,ofcourse, subtle effects near foci, caustics or turning points would need an analysis based on the wave natureoflight. Allofgeometric optics can be derived from Fermat's principle which is an extremum principle. The counterpart in classical mechanics is of course Hamilton's principle. There is a very close analogy between mechanics ofparticles and optics oflight rays. Much insight (and useful results) can be obtained by analyzing these analogies. Asnoted by H. Goldstein in his book Classical Mechanics (Addison Wesley, Cambridge, MA, 1956), classical mechanics is only a geometrical optics approximation to a wave theory! In this book we begin with Fermat's principle and obtain the Lagrangian and Hamiltonian pictures of ray propagation through various media. Given the ...

  3. Finite energy electroweak dyon

    Energy Technology Data Exchange (ETDEWEB)

    Kimm, Kyoungtae [Seoul National University, Faculty of Liberal Education, Seoul (Korea, Republic of); Yoon, J.H. [Konkuk University, Department of Physics, College of Natural Sciences, Seoul (Korea, Republic of); Cho, Y.M. [Konkuk University, Administration Building 310-4, Seoul (Korea, Republic of); Seoul National University, School of Physics and Astronomy, Seoul (Korea, Republic of)

    2015-02-01

    The latest MoEDAL experiment at LHC to detect the electroweak monopole makes the theoretical prediction of the monopole mass an urgent issue. We discuss three different ways to estimate the mass of the electroweak monopole. We first present the dimensional and scaling arguments which indicate the monopole mass to be around 4 to 10 TeV. To justify this we construct finite energy analytic dyon solutions which could be viewed as the regularized Cho-Maison dyon, modifying the coupling strength at short distance. Our result demonstrates that a genuine electroweak monopole whose mass scale is much smaller than the grand unification scale can exist, which can actually be detected at the present LHC. (orig.)

  4. Analytic progress on exact lattice chiral symmetry

    International Nuclear Information System (INIS)

    Kikukawa, Y.

    2002-01-01

    Theoretical issues of exact chiral symmetry on the lattice are discussed and related recent works are reviewed. For chiral theories, the construction with exact gauge invariance is reconsidered from the point of view of domain wall fermion. The issue in the construction of electroweak theory is also discussed. For vector-like theories, we discuss unitarity (positivity), Hamiltonian approach, and several generalizations of the Ginsparg-Wilson relation (algebraic and odd-dimensional)

  5. Electroweak gauge anomaly and the new physics scale

    International Nuclear Information System (INIS)

    Akama, K.; Hattori, T.

    1992-01-01

    It is argued that chiral anomalies in the effective gauge theories are allowed, as far as the new physics scale is not too large. In this paper, the authors estimate the anomaly-induced masses of the weak bosons, when the anomalies exist in the electroweak gauge theory, and compare them with the experimental results to extract the upper bound on the new-physics scale

  6. Electroweak interactions at LEP

    International Nuclear Information System (INIS)

    Borgia, B.

    1991-01-01

    Electroweak interaction at LEP are a subject based on a wealth of data, given the success of the CERN e + e - storage ring. The author will report on the results from the four experiments, ALEPH, DELPHI, L3 and OPAL after the analysis of about 1/2 of the data collected in 1989 and 1990. The review will cover the electroweak aspects of the process e + e - → Z* → f bar f where the fermions can be either quarks or leptons. The analysis of experimental data is based on the determination of the cross section integrated on the solid angle and on the asymmetry of forward-backward leptons in the final state. In this game the knowledge of the center mass energy is fundamental as the determination of the luminosity by which the event rate is normalized to compute the absolute cross section. Therefore a specific attention is given to these subjects

  7. Electroweak penguin B decays

    CERN Document Server

    Nikodem, Thomas

    2016-01-01

    Flavour Changing Neutral Currents (FCNC) are sensitive probes for physics beyond the Standard Model (SM), so-called New Physics. An example of a FCNC is the $b \\to s$ quark transition described by the electroweak penguin Feynman diagram shown in Figure 1. In the SM such FCNC are only allowed with a loop structure (as e:g: shown in the figure) and not by tree level processes. In the loops heavy particles appear virtually and do not need to be on shell. Therefore also not yet discovered heavy particles with up to a mass $\\mathcal{O}$(TeV) could virtually contribute significantly to observables. Several recent measurements of electroweak penguin B decays exhibit interesting tensions with SM predictions, most prominently in the angular observable $P'_5$ 5 of the decay $B^0 \\to K^{*0} \\mu^+ \\mu^1$[1], which triggered a lot of discussion in the theory community [2]-[14].

  8. Strong Electroweak Symmetry Breaking

    CERN Document Server

    Grinstein, Benjamin

    2011-01-01

    Models of spontaneous breaking of electroweak symmetry by a strong interaction do not have fine tuning/hierarchy problem. They are conceptually elegant and use the only mechanism of spontaneous breaking of a gauge symmetry that is known to occur in nature. The simplest model, minimal technicolor with extended technicolor interactions, is appealing because one can calculate by scaling up from QCD. But it is ruled out on many counts: inappropriately low quark and lepton masses (or excessive FCNC), bad electroweak data fits, light scalar and vector states, etc. However, nature may not choose the minimal model and then we are stuck: except possibly through lattice simulations, we are unable to compute and test the models. In the LHC era it therefore makes sense to abandon specific models (of strong EW breaking) and concentrate on generic features that may indicate discovery. The Technicolor Straw Man is not a model but a parametrized search strategy inspired by a remarkable generic feature of walking technicolor,...

  9. Electro-weak theory

    International Nuclear Information System (INIS)

    Deshpande, N.G.

    1980-01-01

    By electro-weak theory is meant the unified field theory that describes both weak and electro-magnetic interactions. The development of a unified electro-weak theory is certainly the most dramatic achievement in theoretical physics to occur in the second half of this century. It puts weak interactions on the same sound theoretical footing as quantum elecrodynamics. Many theorists have contributed to this development, which culminated in the works of Glashow, Weinberg and Salam, who were jointly awarded the 1979 Nobel Prize in physics. Some of the important ideas that contributed to this development are the theory of beta decay formulated by Fermi, Parity violation suggested by Lee and Yang, and incorporated into immensely successful V-A theory of weak interactions by Sudarshan and Marshak. At the same time ideas of gauge invariance were applied to weak interaction by Schwinger, Bludman and Glashow. Weinberg and Salam then went one step further and wrote a theory that is renormalizable, i.e., all higher order corrections are finite, no mean feat for a quantum field theory. The theory had to await the development of the quark model of hadrons for its completion. A description of the electro-weak theory is given

  10. Some Lagrangians for systems without a Lagrangian

    International Nuclear Information System (INIS)

    Nucci, M C; Leach, P G L

    2011-01-01

    We demonstrate how to construct many different Lagrangians for two famous examples that were deemed by Douglas (1941 Trans. Am. Math. Soc. 50 71-128) not to have a Lagrangian. Following Bateman's dictum (1931 Phys. Rev. 38 815-9), we determine different sets of equations that are compatible with those of Douglas and derivable from a variational principle.

  11. Electroweak Baryogenesis in R-symmetric Supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Fok, R.; Kribs, Graham D.; Martin, Adam; Tsai, Yuhsin

    2013-03-01

    We demonstrate that electroweak baryogenesis can occur in a supersymmetric model with an exact R-symmetry. The minimal R-symmetric supersymmetric model contains chiral superfields in the adjoint representation, giving Dirac gaugino masses, and an additional set of "R-partner" Higgs superfields, giving R-symmetric \\mu-terms. New superpotential couplings between the adjoints and the Higgs fields can simultaneously increase the strength of the electroweak phase transition and provide additional tree-level contributions to the lightest Higgs mass. Notably, no light stop is present in this framework, and in fact, we require both stops to be above a few TeV to provide sufficient radiative corrections to the lightest Higgs mass to bring it up to 125 GeV. Large CP-violating phases in the gaugino/higgsino sector allow us to match the baryon asymmetry of the Universe with no constraints from electric dipole moments due to R-symmetry. We briefly discuss some of the more interesting phenomenology, particularly of the of the lightest CP-odd scalar.

  12. Chiral perturbation theory with nucleons

    International Nuclear Information System (INIS)

    Meissner, U.G.

    1991-09-01

    I review the constraints posed on the interactions of pions, nucleons and photons by the spontaneously broken chiral symmetry of QCD. The framework to perform these calculations, chiral perturbation theory, is briefly discussed in the meson sector. The method is a simultaneous expansion of the Greens functions in powers of external moments and quark masses around the massless case, the chiral limit. To perform this expansion, use is made of a phenomenological Lagrangian which encodes the Ward-identities and pertinent symmetries of QCD. The concept of chiral power counting is introduced. The main part of the lectures of consists in describing how to include baryons (nucleons) and how the chiral structure is modified by the fact that the nucleon mass in the chiral limit does not vanish. Particular emphasis is put on working out applications to show the strengths and limitations of the methods. Some processes which are discussed are threshold photopion production, low-energy compton scattering off nucleons, πN scattering and the σ-term. The implications of the broken chiral symmetry on the nuclear forces are briefly described. An alternative approach, in which the baryons are treated as very heavy fields, is touched upon

  13. Quantum chromodynamics, chiral symmetry and bag models

    International Nuclear Information System (INIS)

    Soyeur, M.

    1983-08-01

    This course deals with the following subjects: quarks; quantum chromodynamics (the classical Lagrangian of QCD, quark masses, the classical equations of motion of QCD, general properties, lattices); chiral symmetry (massless free Dirac theory, realizations, the σ-model); the M.I.T. bag model (basic assumptions and equations of motion, spherical cavity approximation, properties of hadrons); the chiral bag models (basic assumptions, the cloudy bag model, the little bag model); non-topological soliton bag models

  14. Extending Chiral Perturbation Theory with an Isosinglet Scalar

    DEFF Research Database (Denmark)

    Hansen, Martin; Langaeble, Kasper; Sannino, Francesco

    2017-01-01

    We augment the chiral Lagrangian by an isosinglet scalar and compute the one-loop radiative corrections to the pion mass and decay constant, as well as the scalar mass. The calculations are carried out for different patterns of chiral symmetry breaking of immediate relevance for phenomenology...

  15. Chiral symmetry breaking from Ginsparg-Wilson fermions

    CERN Document Server

    Hernández, Pilar; Lellouch, L P; Hernandez, Pilar; Jansen, Karl; Lellouch, Laurent

    2000-01-01

    We calculate the large-volume and small-mass dependences of the quark condensate in quenched QCD using Neuberger's operator. We find good agreement with the predictions of quenched chiral perturbation theory, enabling a determination of the chiral lagrangian parameter \\Sigma, up to a multiplicative renormalization.

  16. Electroweak physics with LEP

    International Nuclear Information System (INIS)

    Davier, M.

    1992-03-01

    The present status of electroweak physics at LEP is presented. The LEP machine and the detectors are described. The decays of Z neutral bosons in both leptonic and hadronic channels are studied. Neutral and charged sector are investigated, and a precise test of the Standard Model is given. Higgs boson searches and τ decay measurements are also described as well as quark mixing and B 0 B-bar 0 oscillations. All the seven contributions are individually indexed and abstracted for the INIS database. (K.A.) 100 refs

  17. Electroweak precision tests

    International Nuclear Information System (INIS)

    Monteil, St.

    2009-12-01

    This document aims at summarizing a dozen of years of the author's research in High Energy Physics, in particular dealing with precision tests of the electroweak theory. Parity violating asymmetries measurements at LEP with the ALEPH detector together with global consistency checks of the Kobayashi-Maskawa paradigm within the CKM-fitter group are gathered in the first part of the document. The second part deals with the unpublished instrumental work about the design, tests, productions and commissioning of the elements of the Pre-Shower detector of the LHCb spectrometer at LHC. Physics perspectives with LHCb are eventually discussed as a conclusion. (author)

  18. Electroweak probes with ATLAS

    CERN Document Server

    Milov, Alexander; The ATLAS collaboration

    2018-01-01

    Measuring electroweak bosons in relativistic heavy ion collisions at high energy provide an opportunity to understand temporal evolution of the quark-gluon plasma created in such collisions by constraining the initial state of the interaction. Due to lack of colour charges the bosons and or particles produced in their leptonic decays are unaffected by the quark-gluon plasma and therefore preserve the information about the very early stage of the collision when they were born. This singles EW bosons as a unique and very interesting class of observables in HI collisions. The ATLAS experiment at LHC measures production of electroweak bosons in $pp$, $p$+Pb and Pb+Pb collisions systems. A review of the existing results is given in this proceeding that includes studies made with isolated photons to constraint kinematic properties and flavour composition of associated jets, measurements of $W$ and $Z$ bosons used to estimate nuclear modification of PDF and the production rates of the bosons used to verify geometric...

  19. Staggered chiral random matrix theory

    International Nuclear Information System (INIS)

    Osborn, James C.

    2011-01-01

    We present a random matrix theory for the staggered lattice QCD Dirac operator. The staggered random matrix theory is equivalent to the zero-momentum limit of the staggered chiral Lagrangian and includes all taste breaking terms at their leading order. This is an extension of previous work which only included some of the taste breaking terms. We will also present some results for the taste breaking contributions to the partition function and the Dirac eigenvalues.

  20. The hierarchy problem of the electroweak standard model revisited

    International Nuclear Information System (INIS)

    Jegerlehner, Fred

    2013-05-01

    A careful renormalization group analysis of the electroweak Standard Model reveals that there is no hierarchy problem in the SM. In the broken phase a light Higgs turns out to be natural as it is self-protected and self-tuned by the Higgs mechanism. It means that the scalar Higgs needs not be protected by any extra symmetry, specifically super symmetry, in order not to be much heavier than the other SM particles which are protected by gauge- or chiral-symmetry. Thus the existence of quadratic cutoff effects in the SM cannot motivate the need for a super symmetric extensions of the SM, but in contrast plays an important role in triggering the electroweak phase transition and in shaping the Higgs potential in the early universe to drive inflation as supported by observation.

  1. The hierarchy problem of the electroweak standard model revisited

    Energy Technology Data Exchange (ETDEWEB)

    Jegerlehner, Fred [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2013-05-15

    A careful renormalization group analysis of the electroweak Standard Model reveals that there is no hierarchy problem in the SM. In the broken phase a light Higgs turns out to be natural as it is self-protected and self-tuned by the Higgs mechanism. It means that the scalar Higgs needs not be protected by any extra symmetry, specifically super symmetry, in order not to be much heavier than the other SM particles which are protected by gauge- or chiral-symmetry. Thus the existence of quadratic cutoff effects in the SM cannot motivate the need for a super symmetric extensions of the SM, but in contrast plays an important role in triggering the electroweak phase transition and in shaping the Higgs potential in the early universe to drive inflation as supported by observation.

  2. A nonlocal model of chiral dynamics

    International Nuclear Information System (INIS)

    Holdom, B.; Terning, J.; Verbeek, K.

    1989-01-01

    We consider a nonlocal generalization of the nonlinear σ model. Our chirally symmetric model couples quarks with self-energy Σ(p) to Goldstone bosons (GBs). By integrating out the quarks we obtain a chiral lagrangian, the parameters of which are finite integrals of Σ(p). We find that chiral symmetry is not sufficient to derive the well-known Pagels-Stokar formula for the GB decay constant. We reproduce the Wess-Zumino term and we illustrate the dependence of other four derivative coefficients on Σ(p). (orig.)

  3. Chiral dynamics of baryons in the perturbative chiral quark model

    Energy Technology Data Exchange (ETDEWEB)

    Pumsa-ard, K.

    2006-07-01

    In this work we develop and apply variants of a perturbative chiral quark model (PCQM) to the study of baryonic properties dominantly in the low-energy region. In a first step we consider a noncovariant form of the PCQM, where confinement is modelled by a static, effective potential and chiral corrections are treated to second order, in line with similar chiral quark models. We apply the PCQM to the study of the electromagnetic form factors of the baryon octet. We focus in particular on the low-energy observables such as the magnetic moments, the charge and magnetic radii. In addition, the electromagnetic N-delta transition is also studied in the framework of the PCQM. In the chiral loop calculations we consider a quark propagator, which is restricted to the quark ground state, or in hadronic language to nucleon and delta intermediate states, for simplicity. We furthermore include the low-lying excited states to the quark propagator. In particular, the charge radius of the neutron and the transverse helicity amplitudes of the N-delta transition are considerably improved by this additional effect. In a next step we develop a manifestly Lorentz covariant version of the PCQM, where in addition higher order chiral corrections are included. The full chiral quark Lagrangian is motivated by and in analogy to the one of Chiral Perturbation Theory (ChPT). This Lagrangian contains a set of low energy constants (LECs), which are parameters encoding short distance effects and heavy degrees of freedom. We evaluate the chiral Lagrangian to order O(p{sup 4}) and to one loop to generate the dressing of the bare quark operators by pseudoscalar mesons. In addition we include the vector meson degrees of freedom in our study. Projection of the dressed quark operators on the baryonic level serves to calculate the relevant matrix elements. In a first application of this scheme, we resort to a parameterization of the valence quark form factors in the electromagnetic sector. Constraints

  4. Electroweak phase transitions

    International Nuclear Information System (INIS)

    Anderson, G.W.

    1991-01-01

    An analytic treatment of the one Higgs doublet, electroweak phase transition is given. The phase transition is first order, occurs by the nucleation of thin walled bubbles and completes at a temperature where the order parameter, left-angle φ right-angle T is significantly smaller than it is when the origin becomes absolutely unstable. The rate of anomalous baryon number violation is an exponentially function of left-angle φ right-angle T . In very minimal extensions of the standard model it is quite easy to increase left-angle φ right-angle T so that anomalous baryon number violation is suppressed after completion of the phase transition. Hence baryogenesis at the electroweak phase transition is tenable in minimal of the standard model. In some cases additional phase transitions are possible. For a light Higgs boson, when the top quark mass is sufficiently large, the state where the Higgs field has a vacuum expectation value left-angle φ right-angle = 246 GeV is not the true minimum of the Higgs potential. When this is the case, and when the top quark mass exceeds some critical value, thermal fluctuations in the early universe would have rendered the state left-angle φ right-angle = 246 GeV unstable. The requirement that the state left-angle φ right-angle = 246 GeV is sufficiently long lived constrains the masses of the Higgs boson and the top quark. Finally, we consider whether local phase transitions can be induced by heavy particles which act as seeds for deformations in the scalar field

  5. Hamiltonian formulation of anomaly free chiral bosons

    International Nuclear Information System (INIS)

    Abdalla, E.; Abdalla, M.C.B.; Devecchi, F.P.; Zadra, A.

    1988-01-01

    Starting out of an anomaly free Lagrangian formulation for chiral scalars, which a Wess-Zumino Term (to cancel the anomaly), we formulate the corresponding hamiltonian problem. Ther we use the (quantum) Siegel invariance to choose a particular, which turns out coincide with the obtained by Floreanini and Jackiw. (author) [pt

  6. CP-violation in K0(K-bar0) → 3π decays from chiral Lagrangians with fourth-order derivative terms, including isospin-breaking and rescattering effects

    International Nuclear Information System (INIS)

    Bel'kov, A.A.; Lanyov, A.V.; Ebert, D.

    1990-08-01

    In the framework of recently proposed effective Lagrangians for weak nonleptonic meson interactions the amplitudes of the decays K 0 → 3π have been calculated with inclusion of isospin breaking and meson rescattering effects. The imaginary part of the penguin diagram contribution, which determines direct CP-violation in nonleptonic kaon decays, has been fixed with the help of the measured ratio ε'/ε of CP-violation parameters. The modification of the Li-Wolfenstein relation for the direct CP-violation parameter in K 0 (K-bar 0 ) → π + π - π 0 decays is discussed. (author). 27 refs, 3 figs, 1 tab

  7. Effective Lagrangian of QED

    International Nuclear Information System (INIS)

    Kaminski, J.Z.

    1981-01-01

    A renormalization group equation for the effective Lagrangian of QED is obtained. Starting from this equation, perturbation theory for the renormalization group equation (PTRGE) is developed. The results are in full agreement with the standard perturbation theory. Conjecturing that the asymptotic effective coupling constant is finite, the effective Lagrangian for a strong magnetic field is obtained, which is proportional to the Maxwellian Lagrangian. For the asymptotically free theories the situation is diametrically opposed to QED. In these cases the effective Lagrangian of the Yang-Mills system tends to infinity for very strong external Yang-Mills fields. (Auth.)

  8. Extra generations and discrepancies of electroweak precision data

    OpenAIRE

    Novikov, V. A.; Okun, L. B.; Rozanov, A. N.; Vysotsky, M. I.

    2001-01-01

    It is shown that additional chiral generations are not excluded by the latest electroweak precision data if one assumes that there is no mixing with the known three generations. In the case of ``heavy extra generations'', when all four new particles are heavier than $Z$ boson, quality of the fit for the one new generation is as good as for zero new generations (Standard Model). In the case of neutral leptons with masses around 50 GeV (``partially heavy extra generations'') the minimum of $\\ch...

  9. Electroweak Physics at the LHC

    CERN Document Server

    Sommer, Philip; The ATLAS collaboration

    2018-01-01

    With the large integrated luminosities recorded at the LHC and the excellent understanding of the LHC detectors, it is possible to measure electroweak observables to the highest precision. A review of the measurement of the $W$ boson mass by the ATLAS Collaboration as well as a new measurement of the electroweak mixing angle with the CMS detector are presented. Special emphasis is put on a discussion of the modelling uncertainties and the potential of the latest low-$\\mu$ runs, recorded at the end of 2017 by both collaboration. In addition, the latest measurements of multi-boson final states as well as the electroweak production of single gauge bosons at 13 TeV are summarised. The study of these processes can be used to constrain anomalous gauge couplings in an effective field theory approach, allowing to bridge tests of the electroweak sector of the Standard Models also to Higgs boson production.

  10. Electroweak Physics at the LHC

    CERN Document Server

    Sommer, Philip; The ATLAS collaboration

    2018-01-01

    With the high integrated luminosities recorded at the LHC and the very good understanding of the LHC detectors, it is possible to measure electroweak observables to the highest precision. In this talk, we review the measurement of the W boson mass by the ATLAS Collaboration as well as the new measurement of the electroweak mixing angle with the CMS detector. Special focus is drawn on a discussion of the modeling uncertainties and the physics potential of the latest low-mu runs, recorded at the end of 2017 by both collaboration. In addition, we will present the latest measurements of multi-boson final states as well as the electroweak production of single gauge bosons at 13 TeV. The study of these processes can be used to constrain anomalous gauge couplings in an effective field theory approach, allowing to bridge tests of the electroweak sector of the Standard Models also to the Higgs-boson production.

  11. Electroweak physics and electron scattering

    International Nuclear Information System (INIS)

    Henley, E.M.; Hwang, W.Y.P.

    1988-01-01

    The electroweak theory is developed and applied to electron scattering from nucleons and light nuclei. It is shown that these scatterings can be used to test the standard theory and probe structure effects. 33 refs., 5 figs

  12. Lagrangians for generalized Argyres-Douglas theories

    Science.gov (United States)

    Benvenuti, Sergio; Giacomelli, Simone

    2017-10-01

    We continue the study of Lagrangian descriptions of N=2 Argyres-Douglas theories. We use our recent interpretation in terms of sequential confinement to guess the Lagrangians of all the Argyres-Douglas models with Abelian three dimensional mirror. We find classes of four dimensional N=1 quivers that flow in the infrared to generalized Argyres-Douglas theories, such as the ( A k , A kN + N -1) models. We study in detail how the N=1 chiral rings map to the Coulomb and Higgs Branches of the N=2 CFT's. The three dimensional mirror RG flows are shown to land on the N=4 complete graph quivers. We also compactify to three dimensions the gauge theory dual to ( A 1, D 4), and find the expected Abelianization duality with N=4 SQED with 3 flavors.

  13. Electroweak results from the tevatron

    International Nuclear Information System (INIS)

    Wood, D.

    1997-01-01

    Electroweak results are presented from the CDF and DO experiments based on data collected in recent runs of the Fermilab Tevatron Collider. The measurements include the mass and width of the W boson, the production cross sections of the W and Z bosons, and the W charge asymmetry. Additional results come from studies of events with pairs of electroweak gauge bosons and include limits on anomalous couplings

  14. Baryogenesis at the electroweak scale

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, A [Saha Inst. of Nuclear Physics, Calcutta (India); Mallik, S [Saha Inst. of Nuclear Physics, Calcutta (India)

    1995-10-01

    The generation of the baryon asymmetry of the universe is considered in the standard model of the electroweak theory with simple extensions of the Higgs sector. The propagation of quarks of masses up to about 5 GeV are considered, taking into account their markedly different dispersion relations due to propagation through the hot electroweak plasma. It is shown that the contribution of the b quark to the baryon asymmetry can be comparable to that for the t quark considered earlier. (orig.)

  15. Baryogenesis at the electroweak scale

    International Nuclear Information System (INIS)

    Kundu, A.; Mallik, S.

    1995-01-01

    The generation of the baryon asymmetry of the universe is considered in the standard model of the electroweak theory with simple extensions of the Higgs sector. The propagation of quarks of masses up to about 5 GeV are considered, taking into account their markedly different dispersion relations due to propagation through the hot electroweak plasma. It is shown that the contribution of the b quark to the baryon asymmetry can be comparable to that for the t quark considered earlier. (orig.)

  16. Electroweak results from the tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Wood, D. [Fermi National Accelerator Laboratory, Batavia, IL (United States)

    1997-01-01

    Electroweak results are presented from the CDF and DO experiments based on data collected in recent runs of the Fermilab Tevatron Collider. The measurements include the mass and width of the W boson, the production cross sections of the W and Z bosons, and the W charge asymmetry. Additional results come from studies of events with pairs of electroweak gauge bosons and include limits on anomalous couplings.

  17. Quantum transport and electroweak baryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Konstandin, Thomas

    2013-02-15

    We review the mechanism of electroweak baryogenesis. The main focus of the review lies on the development of quantum transport equations from first principles in the Kadanoff-Baym framework. We emphasize the importance of the semi-classical force that leads to reliable predictions in most cases. Besides, we discuss the status of electroweak baryogenesis in the light of recent electric dipole moment probes and collider experiments in a variety of models.

  18. Electroweak boson production at LHCb

    CERN Document Server

    Sestini, Lorenzo

    2018-01-01

    The LHCb experiment offers a complementary phase space to ATLAS and CMS to study electroweak processes, thanks to the forward acceptance and the large bandwidth of the trigger allowing low energy thresholds. For this reason electroweak measurements at LHCb can provide unique constraints to the Parton Distribution Functions. Moreover these measurements can be used to validate reconstruction techniques. In these proceedings the latest measurements on W and Z bosons production performed during the LHC Run I and Run II data taking are presented.

  19. Quantum transport and electroweak baryogenesis

    International Nuclear Information System (INIS)

    Konstandin, Thomas

    2013-02-01

    We review the mechanism of electroweak baryogenesis. The main focus of the review lies on the development of quantum transport equations from first principles in the Kadanoff-Baym framework. We emphasize the importance of the semi-classical force that leads to reliable predictions in most cases. Besides, we discuss the status of electroweak baryogenesis in the light of recent electric dipole moment probes and collider experiments in a variety of models.

  20. Electroweak physics at LEP2

    CERN Document Server

    Hemingway, Richard J

    2002-01-01

    On 2 November 2000 the LEP machine was finally closed after 12 years of glorious running. With the 4 operating detectors, ALEPH, DELPHI, L3, and OPAL, an enormous wealth of new data at the highest centre- of-mass energies has been recorded. These lectures will focus on aspects of electroweak physics within the energy span of LEP2, namely 130-209 GeV. All current data are in very good agreement with the electroweak standard model. (50 refs).

  1. Super-Lagrangians

    International Nuclear Information System (INIS)

    Beyl, L.M.

    1979-01-01

    It is shown that the Einstein, Weyl, supergravity and superconformal theories are special cases of gauge transformations in SU(4vertical-barN). This group is shown to contain SU(2,2) x SU(N) x U(1) for its commuting or Bose part, and to contain 8N supersymmetry generators for its anticommuting or Fermi part. Using the electromagnetic Lagrangian as a model, a super-Lagrangian is constructed for vector potentials. Invariance is automatic in free space, but, in the presence of matter, restrictions on the supersymmetry transformations are necessary. The Weyl action and the Einstein cosmological field equations are obtained in the appropriate limits. Finally, a super-Lagrangian is constructed from nongeometric principles which includes the Dirac Lagrangian and except for a sum over symmetry indices resembles the electron-electromagnetic Lagrangian

  2. Chiral superconductors.

    Science.gov (United States)

    Kallin, Catherine; Berlinsky, John

    2016-05-01

    Chiral superconductivity is a striking quantum phenomenon in which an unconventional superconductor spontaneously develops an angular momentum and lowers its free energy by eliminating nodes in the gap. It is a topologically non-trivial state and, as such, exhibits distinctive topological modes at surfaces and defects. In this paper we discuss the current theory and experimental results on chiral superconductors, focusing on two of the best-studied systems, Sr2RuO4, which is thought to be a chiral triplet p-wave superconductor, and UPt3, which has two low-temperature superconducting phases (in zero magnetic field), the lower of which is believed to be chiral triplet f-wave. Other systems that may exhibit chiral superconductivity are also discussed. Key signatures of chiral superconductivity are surface currents and chiral Majorana modes, Majorana states in vortex cores, and the possibility of half-flux quantum vortices in the case of triplet pairing. Experimental evidence for chiral superconductivity from μSR, NMR, strain, polar Kerr effect and Josephson tunneling experiments are discussed.

  3. Precision electroweak physics at the Tevatron

    International Nuclear Information System (INIS)

    James, Eric B.

    2006-01-01

    An overview of Tevatron electroweak measurements performed by the CDF and Dφ experiments is presented. The current status and future prospects for high precision measurements of electroweak parameters and detailed studies of boson production are highlighted. (author)

  4. TRISTAN electroweak working group report

    International Nuclear Information System (INIS)

    Hagiwara, K.

    1995-01-01

    Model-independent measurements of quantities sensitive to the electroweak physics at TRISTAN energies are proposed for the processes e + e - → e + e - , μ + μ - , τ + τ - , hadrons and heavy-quark (charm- and bottom-quark) jets. Factorization of the scattering amplitudes into the part which is sensitive to short-distance electroweak physics and the rest which is sensitive to long-distance QED and QCD corrections is made, and uncertainties in the latter are studied quantitatively by using existing programs. Electroweak observables are then chosen for each processes such that the uncertainty from the long-distance physics is small and that they can be updated when we reach a better understanding of the QED and QCD corrections. The new scheme will make the data from high luminosity TRISTAN experiments useful for particle physicists of the present as well as those of the future generation. (author)

  5. Isotopic chirality

    Energy Technology Data Exchange (ETDEWEB)

    Floss, H.G. [Univ. of Washington, Seattle, WA (United States)

    1994-12-01

    This paper deals with compounds that are chiral-at least in part, due to isotope substitution-and their use in tracing the steric course of enzyme reaction in vitro and in vivo. There are other applications of isotopically chiral compounds (for example, in analyzing the steric course of nonenzymatic reactions and in probing the conformation of biomolecules) that are important but they will not be discussed in this context.

  6. The chiral anomaly in non-leptonic weak interactions

    International Nuclear Information System (INIS)

    Bijnens, J.; Pich, A.; Ecker, G.

    1992-01-01

    The interplay between the chiral anomaly and the non-leptonic weak hamiltonian is studied. The structure of the corresponding effective lagrangian of odd intrinsic parity is established. It is shown that the factorizable contributions (leading in 1/N C ) to that lagrangian can be calculated without free parameters. As a first application, the decay K + →π + π 0 γ is investigated. (orig.)

  7. Strong coupling electroweak symmetry breaking

    International Nuclear Information System (INIS)

    Barklow, T.L.; Burdman, G.; Chivukula, R.S.

    1997-04-01

    The authors review models of electroweak symmetry breaking due to new strong interactions at the TeV energy scale and discuss the prospects for their experimental tests. They emphasize the direct observation of the new interactions through high-energy scattering of vector bosons. They also discuss indirect probes of the new interactions and exotic particles predicted by specific theoretical models

  8. STANFORD (SLAC): Precision electroweak result

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Precision testing of the electroweak sector of the Standard Model has intensified with the recent publication* of results from the SLD collaboration's 1993 run on the Stanford Linear Collider, SLC. Using a highly polarized electron beam colliding with an unpolarized positron beam, SLD physicists measured the left-right asymmetry at the Z boson resonance with dramatically improved accuracy over 1992

  9. Spin and precision electroweak physics

    Energy Technology Data Exchange (ETDEWEB)

    Marciano, W.J. [Brookhaven National Lab., Upton, NY (United States)

    1994-12-01

    A perspective on fundamental parameters and precision tests of the Standard Model is given. Weak neutral current reactions are discussed with emphasis on those processes involving (polarized) electrons. The role of electroweak radiative corrections in determining the top quark mass and probing for {open_quotes}new physics{close_quotes} is described.

  10. Strong coupling electroweak symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Barklow, T.L. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Burdman, G. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics; Chivukula, R.S. [Boston Univ., MA (United States). Dept. of Physics

    1997-04-01

    The authors review models of electroweak symmetry breaking due to new strong interactions at the TeV energy scale and discuss the prospects for their experimental tests. They emphasize the direct observation of the new interactions through high-energy scattering of vector bosons. They also discuss indirect probes of the new interactions and exotic particles predicted by specific theoretical models.

  11. Spin and precision electroweak physics

    International Nuclear Information System (INIS)

    Marciano, W.J.

    1993-01-01

    A perspective on fundamental parameters and precision tests of the Standard Model is given. Weak neutral current reactions are discussed with emphasis on those processes involving (polarized) electrons. The role of electroweak radiative corrections in determining the top quark mass and probing for ''new physics'' is described

  12. Electroweak results from hadron colliders

    International Nuclear Information System (INIS)

    Demarteau, Marcel

    1997-01-01

    A review of recent electroweak results from hadron colliders is given. Properties of the W ± and Z 0 gauge bosons using final states containing electrons and muons based on large integrated luminosities are presented. The emphasis is placed on the measurement of the mass of the W boson and the measurement of trilinear gauge boson couplings

  13. Electroweak physics from D0

    International Nuclear Information System (INIS)

    Roe, N.A.

    1993-05-01

    The D0 detector was recently commissioned at the Tevatron p bar p collider and is presently taking data. Preliminary results from D0 are presented on properties of the W and Z electroweak gauge bosons, using final states containing electrons and muons

  14. Chiral perturbation theory

    International Nuclear Information System (INIS)

    Harada, Masayasu

    2009-01-01

    Chiral perturbation theory has been used for great number of phenomenological analyses in low energy QCD as well as the lattice QCD analyses since the creation of the theory by Weinberg in 1979 followed by its consolidation by Gasser and Leutwyler in 1984 and 85. The theory is now the highly established one as the approach based on the effective field theory to search for Green function including quantum correlations in the frame of the systematic expansion technique using Lagrangian which includes all of the terms allowed by the symmetry. This review has been intended to describe how systematically physical quantities are calculated in the framework of the chiral symmetry. Consequently many of the various phenomenological analyses are not taken up here for which other reports are to be referred. Further views are foreseen to be developed based on the theory in addition to numbers of results reported up to the present. Finally π-π scattering is taken up to discuss to what energy scale the theory is available. (S. Funahashi)

  15. Chiral quarks and proton decay

    International Nuclear Information System (INIS)

    Chadha, S.; Daniel, M.; Gounaris, G.J.; Murphy, A.J.

    1984-04-01

    The authors calculate the hadronic matrix elements of baryon decay operators using a chiral effective Lagrangian with quarks, gluons and Goldstone boson fields. The cases where the ΔB=1 operators arise from supersymmetric SU(5) GUT as well as the minimal SU(5) GUT model are studied. In each model the results depend on two parameters. In particular there is a range of values for the two parameters, where the dominant decay modes in the minimal SU(5) GUT are: p→etae + and n→π - e + . (author)

  16. Low-energy meson physics (chiral theory)

    International Nuclear Information System (INIS)

    Volkov, M.K.; Pervushin, V.N.

    1976-01-01

    A quantum chiral theory which allows to obtain low-energy expansions of various hadron processes without introducing arbitrary parameters into the theory with the exception of hadron masses and interaction constants is presented. A hypothesis about the dynamic symmetry of strong interactions is suggested. The interaction lagrangian is derived which satisfies conditions of the dynamic symmetry. Examples of the use of the quantum chiral theory for describing low-energy processes of meson interaction are given. It is noted that the results obtained reproduce the actual qualitative pattern of various physical processes and in most cases result in good quantitative agreement with experiments

  17. Vanishing chiral couplings in the large-NC resonance theory

    International Nuclear Information System (INIS)

    Portoles, Jorge; Rosell, Ignasi; Ruiz-Femenia, Pedro

    2007-01-01

    The construction of a resonance theory involving hadrons requires implementing the information from higher scales into the couplings of the effective Lagrangian. We consider the large-N C chiral resonance theory incorporating scalars and pseudoscalars, and we find that, by imposing LO short-distance constraints on form factors of QCD currents constructed within this theory, the chiral low-energy constants satisfy resonance saturation at NLO in the 1/N C expansion

  18. Sigma Terms and Strangeness Contents of Baryon Octet in Modified Chiral Perturbation Theory

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-Ya; L(U) Xiao-Fu

    2006-01-01

    In the frame work of chiral perturbation theory, a modified effective Lagrangian for meson-baryon system is constructed, where the SU(3) breaking effect for meson is considered. The difference between physical and chiral limit decay constants is taken into account. Calculated to one loop at O(p3), the sigma terms and strangeness contents of baryon octet are obtained.

  19. Lagrangian and Hamiltonian dynamics

    CERN Document Server

    Mann, Peter

    2018-01-01

    An introductory textbook exploring the subject of Lagrangian and Hamiltonian dynamics, with a relaxed and self-contained setting. Lagrangian and Hamiltonian dynamics is the continuation of Newton's classical physics into new formalisms, each highlighting novel aspects of mechanics that gradually build in complexity to form the basis for almost all of theoretical physics. Lagrangian and Hamiltonian dynamics also acts as a gateway to more abstract concepts routed in differential geometry and field theories and can be used to introduce these subject areas to newcomers. Journeying in a self-contained manner from the very basics, through the fundamentals and onwards to the cutting edge of the subject, along the way the reader is supported by all the necessary background mathematics, fully worked examples, thoughtful and vibrant illustrations as well as an informal narrative and numerous fresh, modern and inter-disciplinary applications. The book contains some unusual topics for a classical mechanics textbook. Mo...

  20. Magnetic fields and chiral asymmetry in the early hot universe

    International Nuclear Information System (INIS)

    Sydorenko, Maksym; Shtanov, Yuri; Tomalak, Oleksandr

    2016-01-01

    In this paper, we study analytically the process of external generation and subsequent free evolution of the lepton chiral asymmetry and helical magnetic fields in the early hot universe. This process is known to be affected by the Abelian anomaly of the electroweak gauge interactions. As a consequence, chiral asymmetry in the fermion distribution generates magnetic fields of non-zero helicity, and vice versa. We take into account the presence of thermal bath, which serves as a seed for the development of instability in magnetic field in the presence of externally generated lepton chiral asymmetry. The developed helical magnetic field and lepton chiral asymmetry support each other, considerably prolonging their mutual existence, in the process of 'inverse cascade' transferring magnetic-field power from small to large spatial scales. For cosmologically interesting initial conditions, the chiral asymmetry and the energy density of helical magnetic field are shown to evolve by scaling laws, effectively depending on a single combined variable. In this case, the late-time asymptotics of the conformal chiral chemical potential reproduces the universal scaling law previously found in the literature for the system under consideration. This regime is terminated at lower temperatures because of scattering of electrons with chirality change, which exponentially washes out chiral asymmetry. We derive an expression for the termination temperature as a function of the chiral asymmetry and energy density of helical magnetic field.

  1. Magnetic fields and chiral asymmetry in the early hot universe

    Energy Technology Data Exchange (ETDEWEB)

    Sydorenko, Maksym; Shtanov, Yuri [Bogolyubov Institute for Theoretical Physics, 03680 Kiev (Ukraine); Tomalak, Oleksandr, E-mail: maxsydorenko@gmail.com, E-mail: tomalak@uni-mainz.de, E-mail: shtanov@bitp.kiev.ua [Institut für Kernphysik, Johannes Gutenberg Universität, 55128 Mainz (Germany)

    2016-10-01

    In this paper, we study analytically the process of external generation and subsequent free evolution of the lepton chiral asymmetry and helical magnetic fields in the early hot universe. This process is known to be affected by the Abelian anomaly of the electroweak gauge interactions. As a consequence, chiral asymmetry in the fermion distribution generates magnetic fields of non-zero helicity, and vice versa. We take into account the presence of thermal bath, which serves as a seed for the development of instability in magnetic field in the presence of externally generated lepton chiral asymmetry. The developed helical magnetic field and lepton chiral asymmetry support each other, considerably prolonging their mutual existence, in the process of 'inverse cascade' transferring magnetic-field power from small to large spatial scales. For cosmologically interesting initial conditions, the chiral asymmetry and the energy density of helical magnetic field are shown to evolve by scaling laws, effectively depending on a single combined variable. In this case, the late-time asymptotics of the conformal chiral chemical potential reproduces the universal scaling law previously found in the literature for the system under consideration. This regime is terminated at lower temperatures because of scattering of electrons with chirality change, which exponentially washes out chiral asymmetry. We derive an expression for the termination temperature as a function of the chiral asymmetry and energy density of helical magnetic field.

  2. Unanswered Questions in the Electroweak Theory

    Energy Technology Data Exchange (ETDEWEB)

    Quigg, Chris

    2009-11-01

    This article is devoted to the status of the electroweak theory on the eve of experimentation at CERN's Large Hadron Collider. A compact summary of the logic and structure of the electroweak theory precedes an examination of what experimental tests have established so far. The outstanding unconfirmed prediction of the electroweak theory is the existence of the Higgs boson, a weakly interacting spin-zero particle that is the agent of electroweak symmetry breaking, the giver of mass to the weak gauge bosons, the quarks, and the leptons. General arguments imply that the Higgs boson or other new physics is required on the TeV energy scale. Indirect constraints from global analyses of electroweak measurements suggest that the mass of the standard-model Higgs boson is less than 200 GeV. Once its mass is assumed, the properties of the Higgs boson follow from the electroweak theory, and these inform the search for the Higgs boson. Alternative mechanisms for electroweak symmetry breaking are reviewed, and the importance of electroweak symmetry breaking is illuminated by considering a world without a specific mechanism to hide the electroweak symmetry. For all its triumphs, the electroweak theory has many shortcomings.

  3. Unanswered Questions in the Electroweak Theory

    International Nuclear Information System (INIS)

    Quigg, Chris

    2009-01-01

    This article is devoted to the status of the electroweak theory on the eve of experimentation at CERN's Large Hadron Collider. A compact summary of the logic and structure of the electroweak theory precedes an examination of what experimental tests have established so far. The outstanding unconfirmed prediction of the electroweak theory is the existence of the Higgs boson, a weakly interacting spin-zero particle that is the agent of electroweak symmetry breaking, the giver of mass to the weak gauge bosons, the quarks, and the leptons. General arguments imply that the Higgs boson or other new physics is required on the TeV energy scale. Indirect constraints from global analyses of electroweak measurements suggest that the mass of the standard-model Higgs boson is less than 200 GeV. Once its mass is assumed, the properties of the Higgs boson follow from the electroweak theory, and these inform the search for the Higgs boson. Alternative mechanisms for electroweak symmetry breaking are reviewed, and the importance of electroweak symmetry breaking is illuminated by considering a world without a specific mechanism to hide the electroweak symmetry. For all its triumphs, the electroweak theory has many shortcomings.

  4. Precision electroweak physics at LEP

    Energy Technology Data Exchange (ETDEWEB)

    Mannelli, M.

    1994-12-01

    Copious event statistics, a precise understanding of the LEP energy scale, and a favorable experimental situation at the Z{sup 0} resonance have allowed the LEP experiments to provide both dramatic confirmation of the Standard Model of strong and electroweak interactions and to place substantially improved constraints on the parameters of the model. The author concentrates on those measurements relevant to the electroweak sector. It will be seen that the precision of these measurements probes sensitively the structure of the Standard Model at the one-loop level, where the calculation of the observables measured at LEP is affected by the value chosen for the top quark mass. One finds that the LEP measurements are consistent with the Standard Model, but only if the mass of the top quark is measured to be within a restricted range of about 20 GeV.

  5. Electroweak bubble wall speed limit

    Energy Technology Data Exchange (ETDEWEB)

    Bödeker, Dietrich [Fakultät für Physik, Universität Bielefeld, 33501 Bielefeld (Germany); Moore, Guy D., E-mail: bodeker@physik.uni-bielefeld.de, E-mail: guymoore@ikp.physik.tu-darmstadt.de [Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstraße 2, 64289 Darmstadt (Germany)

    2017-05-01

    In extensions of the Standard Model with extra scalars, the electroweak phase transition can be very strong, and the bubble walls can be highly relativistic. We revisit our previous argument that electroweak bubble walls can 'run away,' that is, achieve extreme ultrarelativistic velocities γ ∼ 10{sup 14}. We show that, when particles cross the bubble wall, they can emit transition radiation. Wall-frame soft processes, though suppressed by a power of the coupling α, have a significance enhanced by the γ-factor of the wall, limiting wall velocities to γ ∼ 1/α. Though the bubble walls can move at almost the speed of light, they carry an infinitesimal share of the plasma's energy.

  6. Lepton-mediated electroweak baryogenesis

    International Nuclear Information System (INIS)

    Chung, Daniel J. H.; Garbrecht, Bjorn; Ramsey-Musolf, Michael J.; Tulin, Sean

    2010-01-01

    We investigate the impact of the tau and bottom Yukawa couplings on the transport dynamics for electroweak baryogenesis in supersymmetric extensions of the standard model. Although it has generally been assumed in the literature that all Yukawa interactions except those involving the top quark are negligible, we find that the tau and bottom Yukawa interaction rates are too fast to be neglected. We identify an illustrative 'lepton-mediated electroweak baryogenesis' scenario in which the baryon asymmetry is induced mainly through the presence of a left-handed leptonic charge. We derive analytic formulas for the computation of the baryon asymmetry that, in light of these effects, are qualitatively different from those in the established literature. In this scenario, for fixed CP-violating phases, the baryon asymmetry has opposite sign compared to that calculated using established formulas.

  7. Fit to Electroweak Precision Data

    International Nuclear Information System (INIS)

    Erler, Jens

    2006-01-01

    A brief review of electroweak precision data from LEP, SLC, the Tevatron, and low energies is presented. The global fit to all data including the most recent results on the masses of the top quark and the W boson reinforces the preference for a relatively light Higgs boson. I will also give an outlook on future developments at the Tevatron Run II, CEBAF, the LHC, and the ILC

  8. Precision measurements of electroweak parameters

    CERN Document Server

    Savin, Alexander

    2017-01-01

    A set of selected precise measurements of the SM parameters from the LHC experiments is discussed. Results on W-mass measurement and forward-backward asymmetry in production of the Drell--Yan events in both dielectron and dimuon decay channels are presented together with results on the effective mixing angle measurements. Electroweak production of the vector bosons in association with two jets is discussed.

  9. Models of electroweak symmetry breaking

    CERN Document Server

    Pomarol, Alex

    2015-01-01

    This chapter present models of electroweak symmetry breaking arising from strongly interacting sectors, including both Higgsless models and mechanisms involving a composite Higgs. These scenarios have also been investigated in the framework of five-dimensional warped models that, according to the AdS/CFT correspondence, have a four-dimensional holographic interpretation in terms of strongly coupled field theories. We explore the implications of these models at the LHC.

  10. LHCb: Electroweak studies at LHCb

    CERN Multimedia

    Salustino Guimaraes, V

    2012-01-01

    Results on the measurement of the $W^{\\pm}$ and $Z^{0}$ cross-sections are presented using final state leptons with pseudorapidities between 2 and 4.5. Due to its acceptance, LHCb can probe a regime of low low-x electroweak boson production, where parton distribution functions are not well constrained. We summarize the $W^{\\pm}$ measurements performed in the decay $\\mu^{\\pm}\

  11. An alternative prescription for Gauging Floreanini-Jackiw chiral bosons

    International Nuclear Information System (INIS)

    Dias, S.A.; Souza Dutra, A. de.

    1991-01-01

    We seek new couplings of chiral bosons to U (1) gauge fields. Lorentz covariance of the resulting constrained Lagrangian is checked with the help of a procedure based in the first-order formalism of Faddeev and Jackiw. We find Harada's constraint and another local one not previously considered, besides infinite non-local couplings.We analyze the constraint structure and part of the spectrum of this second solution and show that it is equivalent to an explicitly covariant coupling of Siegel's chiral boson to gauge fields, which preserves chirality under gauge transformations. (author)

  12. Chirality invariance and 'chiral' fields

    International Nuclear Information System (INIS)

    Ziino, G.

    1978-01-01

    The new field model derived in the present paper actually gives a definite answer to three fundamental questions concerning elementary-particle physics: 1) The phenomenological dualism between parity and chirality invariance: it would be only an apparent display of a general 'duality' principle underlying the intrinsic nature itself of (spin 1/2) fermions and expressed by the anticommutativity property between scalar and pseudoscalar charges. 2) The real physical meaning of V - A current structure: it would exclusively be connected to the one (just pointed out) of chiral fields themselves. 3) The unjustified apparent oddness shown by Nature in weak interactions, for the fact of picking out only one of the two (left- and right-handed) fermion 'chiral' projections: the key to such a 'mystery' would just be provided by the consequences of the dual and partial character of the two fermion-antifermion field bases. (Auth.)

  13. CP-violating profile of the electroweak bubble wall

    Energy Technology Data Exchange (ETDEWEB)

    Funakubo, Koichi [Saga Univ. (Japan). Dept. of Physics; Kakuto, Akira; Otsuki, Shoichiro; Takenaga, Kazunori; Toyoda, Fumihiko

    1995-11-01

    In any scenario of the electroweak baryogenesis, the profile of the CP violating bubble wall, created at the first-order phase transition, plays an essential role. We attempt to determine it by solving the equations of motion for the scalars in the two-Higgs-doublet model at the transition temperature. According to the parameters in the potential, we found three solutions. Two of them smoothly connect the CP-violating broken phase and the symmetric phase, while the other connects CP-conserving vacua but violates CP in the intermediate region. We also estimate the chiral charge flux, which will be turned into the baryon density in the symmetric phase by the sphaleron process. (author).

  14. Charge radii of octet and decuplet baryons in chiral constituent ...

    Indian Academy of Sciences (India)

    in electron–baryon scattering experiments [4,5] giving rp = 0.877 ± 0.007 fm ... breaking of the SU(3) symmetry and a non-vanishing neutron charge mean square radius ... QCD Lagrangian is not invariant under the chiral transformation. ... of a constituent quark GBs [34–37], successfully explains the 'proton spin problem'.

  15. The role of resonances in chiral perturbation theory

    International Nuclear Information System (INIS)

    Ecker, G.; Rafael, E. de

    1988-09-01

    The strong interactions of low-lying meson resonances (spin ≤ 1) with the octet of pseudoscalar mesons (π,Κ,η) are considered to lowest order in the derivative expansion of chiral SU(3). The resonance contributions to the coupling constants of the O(p 4 ) effective chiral lagrangian involving pseudoscalar fields only are determined. These low-energy coupling constants are found to be dominated by the resonance contributions. Although we do not treat the vector and axial-vector mesons as gauge bosons of local chiral symmetry, vector meson dominance emerges as a prominent result of our analysis. As a further application of chiral resonance couplings, we calculate the electromagnetic pion mass difference to lowest order in chiral perturbation theory with explicit resonance fields. 29 refs., 2 figs., 5 tabs. (Author)

  16. Chirality, nongauge couplings and compositeness

    International Nuclear Information System (INIS)

    Suzuki, Mahiko

    1985-01-01

    We study from a phenomenological viewpoint what constraints exist on a possible scale of compositeness for W, Z, leptons, and quarks. A few critical arguments are presented about excited fermions and spinless partners of W and Z. It is argued that irrespective of a compositeness scale, the coupling of an excited fermion to a ground state light fermion is likely to be maximally parity violating. Besides chirality breaking interactions of light fermions, gauge noninvariant, dimensionless, unrenormalizable couplings are specially interesting in many classes of composite theories. The deviation of the W magnetic moment from the standard theory (g = 2) is such an example. We relate the ''g-2'' of W to a compositeness scale through an unitarity argument and make a guess on its effect on the muon g-2 for a given compositeness scale. The present experimental data on the W-Z mass ratio is already accurate enough to indicate that if a compositeness scale is larger than 0(1 TeV), gauge noninvariant couplings of W and Z should be negligibly small and a composite theory is hardly distinguishable from an elementary particle theory at the electroweak energy scale (≅ 250 GeV). However, a compositeness scale close to the electroweak scale can not be ruled out for W and Z at present. (author)

  17. Renormalization and effective lagrangians

    International Nuclear Information System (INIS)

    Polchinski, J.

    1984-01-01

    There is a strong intuitive understanding of renormalization, due to Wilson, in terms of the scaling of effective lagrangians. We show that this can be made the basis for a proof of perturbative renormalization. We first study renormalizability in the language of renormalization group flows for a toy renormalization group equation. We then derive an exact renormalization group equation for a four-dimensional lambda PHI 4 theory with a momentum cutoff. We organize the cutoff dependence of the effective lagrangian into relevant and irrelevant parts, and derive a linear equation for the irrelevant part. A lengthy but straightforward argument establishes that the piece identified as irrelevant actually is so in perturbation theory. This implies renormalizability. The method extends immediately to any system in which a momentum-space cutoff can be used, but the principle is more general and should apply for any physical cutoff. Neither Weinberg's theorem nor arguments based on the topology of graphs are needed. (orig.)

  18. Gravity, Time, and Lagrangians

    Science.gov (United States)

    Huggins, Elisha

    2010-01-01

    Feynman mentioned to us that he understood a topic in physics if he could explain it to a college freshman, a high school student, or a dinner guest. Here we will discuss two topics that took us a while to get to that level. One is the relationship between gravity and time. The other is the minus sign that appears in the Lagrangian. (Why would one…

  19. Chiral perturbation theory approach to hadronic weak amplitudes

    International Nuclear Information System (INIS)

    Rafael, E. de

    1989-01-01

    We are concerned with applications to the non-leptonic weak interactions in the sector of light quark flavors: u, d and s. Both strangeness changing ΔS=1 and ΔS=2 non-leptonic transitions can be described as weak perturbations to the strong effective chiral Lagrangian; the chiral structure of the weak effective Lagrangian being dictated by the transformation properties of the weak non-leptonic Hamiltonian of the Standard Model under global SU(3) Left xSU(3) Right rotations of the quark-fields. These lectures are organized as follows. Section 2 gives a review of the basic properties of chiral symmetry. Section 3 explains the effective chiral realization of the non-leptonic weak Hamiltonian of the Standard Model to lowest order in derivatives and masses. Section 4 deals with non-leptonic weak transitions in the presence of electromagnetism. Some recent applications to radiative kaon decays are reviewed and the effect of the so called electromagnetic penguin like diagrams is also discussed. Section 5 explains the basic ideas of the QCD-hadronic duality approach to the evaluation of coupling constants of the non-leptonic chiral weak Lagrangian. (orig./HSI)

  20. Split NMSSM with electroweak baryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Demidov, S.V.; Gorbunov, D.S. [Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary prospect 7a, Moscow 117312 (Russian Federation); Moscow Institute of Physics and Technology,Institutsky per. 9, Dolgoprudny 141700 (Russian Federation); Kirpichnikov, D.V. [Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary prospect 7a, Moscow 117312 (Russian Federation)

    2016-11-24

    In light of the Higgs boson discovery and other results of the LHC we reconsider generation of the baryon asymmetry in the split Supersymmetry model with an additional singlet superfield in the Higgs sector (non-minimal split SUSY). We find that successful baryogenesis during the first order electroweak phase transition is possible within a phenomenologically viable part of the model parameter space. We discuss several phenomenological consequences of this scenario, namely, predictions for the electric dipole moments of electron and neutron and collider signatures of light charginos and neutralinos.

  1. ELECTROWEAK PHYSICS AND PRECISION STUDIES

    International Nuclear Information System (INIS)

    MARCIANO, W.

    2005-01-01

    The utility of precision electroweak measurements for predicting the Standard Model Higgs mass via quantum loop effects is discussed. Current values of m W , sin 2 θ W (m Z ) # ovr MS# and m t imply a relatively light Higgs which is below the direct experimental bound but possibly consistent with Supersymmetry expectations. The existence of Supersymmetry is further suggested by a 2σ discrepancy between experiment and theory for the muon anomalous magnetic moment. Constraints from precision studies on other types of ''New Physics'' are also briefly described

  2. Electroweak processes at Run 2

    CERN Document Server

    Spalla, Margherita; Sestini, Lorenzo

    2016-01-01

    We present a summary of the studies of the electroweak sector of the Standard Model at LHC after the first year of data taking of Run2, focusing on possible results to be achieved with the analysis of full 2015 and 2016 data. We discuss the measurements of W and Z boson production, with particular attention to the precision determination of basic Standard Model parameters, and the study of multi-boson interactions through the analysis of boson-boson final states. This work is the result of the collaboration between scientists from the ATLAS, CMS and LHCb experiments.

  3. Superconductivity in dense electroweak system

    International Nuclear Information System (INIS)

    Ferrer, E.J.; De La Incera, V.; Shabad, A.E.

    1988-01-01

    The spectrum of fermions in the presence of the W-boson-condensed electro-weak liquid is obtained and nonvanishing spatial component of the fermionic polarization operator is calculated for zero 4-momentum. The manifestation of the Meissner effect is studied. The London penetration depthλ/sub L/ is calculated in the limit of small W-condensate amplitude. The possibility of a special phenomenon of partial magnetic screening due to the mixing angle dependence on the leptonic density is discussed in connection with the magnetic mass problem

  4. Electroweak precision measurements in CMS

    CERN Document Server

    Dordevic, Milos

    2017-01-01

    An overview of recent results on electroweak precision measurements from the CMS Collaboration is presented. Studies of the weak boson differential transverse momentum spectra, Z boson angular coefficients, forward-backward asymmetry of Drell-Yan lepton pairs and charge asymmetry of W boson production are made in comparison to the state-of-the-art Monte Carlo generators and theoretical predictions. The results show a good agreement with the Standard Model. As a proof of principle for future W mass measurements, a W-like analysis of the Z boson mass is performed.

  5. History of electroweak symmetry breaking

    International Nuclear Information System (INIS)

    Kibble, T W B

    2015-01-01

    In this talk, I recall the history of the development of the unified electroweak theory, incorporating the symmetry-breaking Higgs mechanism, as I saw it from my standpoint as a member of Abdus Salam's group at Imperial College. I start by describing the state of physics in the years after the Second World War, explain how the goal of a unified gauge theory of weak and electromagnetic interactions emerged, the obstacles encountered, in particular the Goldstone theorem, and how they were overcome, followed by a brief account of more recent history, culminating in the historic discovery of the Higgs boson in 2012. (paper)

  6. Electroweak breaking in supersymmetric models

    CERN Document Server

    Ibáñez, L E

    1992-01-01

    We discuss the mechanism for electroweak symmetry breaking in supersymmetric versions of the standard model. After briefly reviewing the possible sources of supersymmetry breaking, we show how the required pattern of symmetry breaking can automatically result from the structure of quantum corrections in the theory. We demonstrate that this radiative breaking mechanism works well for a heavy top quark and can be combined in unified versions of the theory with excellent predictions for the running couplings of the model. (To be published in ``Perspectives in Higgs Physics'', G. Kane editor.)

  7. Exact Lagrangian caps and non-uniruled Lagrangian submanifolds

    Science.gov (United States)

    Dimitroglou Rizell, Georgios

    2015-04-01

    We make the elementary observation that the Lagrangian submanifolds of C n , n≥3, constructed by Ekholm, Eliashberg, Murphy and Smith are non-uniruled and, moreover, have infinite relative Gromov width. The construction of these submanifolds involve exact Lagrangian caps, which obviously are non-uniruled in themselves. This property is also used to show that if a Legendrian submanifold inside a contactisation admits an exact Lagrangian cap, then its Chekanov-Eliashberg algebra is acyclic.

  8. Precision experiments in electroweak interactions

    International Nuclear Information System (INIS)

    Swartz, M.L.

    1990-03-01

    The electroweak theory of Glashow, Weinberg, and Salam (GWS) has become one of the twin pillars upon which our understanding of all particle physics phenomena rests. It is a brilliant achievement that qualitatively and quantitatively describes all of the vast quantity of experimental data that have been accumulated over some forty years. Note that the word quantitatively must be qualified. The low energy limiting cases of the GWS theory, Quantum Electrodynamics and the V-A Theory of Weak Interactions, have withstood rigorous testing. The high energy synthesis of these ideas, the GWS theory, has not yet been subjected to comparably precise scrutiny. The recent operation of a new generation of proton-antiproton (p bar p) and electron-positron (e + e - ) colliders has made it possible to produce and study large samples of the electroweak gauge bosons W ± and Z 0 . We expect that these facilities will enable very precise tests of the GWS theory to be performed in the near future. In keeping with the theme of this Institute, Physics at the 100 GeV Mass Scale, these lectures will explore the current status and the near-future prospects of these experiments

  9. Electroweak unification and tree unitarity

    International Nuclear Information System (INIS)

    Horejsi, J.

    1993-01-01

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

  10. CMS results in Electroweak Physics

    CERN Multimedia

    CERN. Geneva

    2011-01-01

    We present the results of electroweak studies performed using data collected in 2010 at a center-of-mass energy of 7 TeV by the CMS experiment at the LHC. Besides their intrinsic interest as unique samples to calibrate and understand the CMS detector response to leptons, jets and missing energy, events containing W and Z bosons appear as dominant components in many Higgs seaches and in most of the searches beyond the Standard Model, either as signal or as background. In addition, the excellent level of theoretical and experimental understanding of these processes allows electroweak tests at the LHC at an unprecendented level of precision. CMS uses a wide range of final states to measure cross sections, asymmetries, polarizations and differential distributions in general. The current integrated luminosity is already sufficient to perform not just inclusive measurements using W and Z decays into muons and electrons, but also precise studies of associated jet production and final states containing taus, as well...

  11. Lagrangian multiforms and multidimensional consistency

    Energy Technology Data Exchange (ETDEWEB)

    Lobb, Sarah; Nijhoff, Frank [Department of Applied Mathematics, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2009-10-30

    We show that well-chosen Lagrangians for a class of two-dimensional integrable lattice equations obey a closure relation when embedded in a higher dimensional lattice. On the basis of this property we formulate a Lagrangian description for such systems in terms of Lagrangian multiforms. We discuss the connection of this formalism with the notion of multidimensional consistency, and the role of the lattice from the point of view of the relevant variational principle.

  12. Lagrangian cobordism and tropical curves

    OpenAIRE

    Sheridan, Nick; Smith, Ivan

    2018-01-01

    We study a cylindrical Lagrangian cobordism group for Lagrangian torus fibres in symplectic manifolds which are the total spaces of smooth Lagrangian torus fibrations. We use ideas from family Floer theory and tropical geometry to obtain both obstructions to and constructions of cobordisms; in particular, we give examples of symplectic tori in which the cobordism group has no non-trivial cobordism relations between pairwise distinct fibres, and ones in which the degree zero fibre cobordism gr...

  13. On the origin of mass and the electroweak mass spectrum without Higgs

    International Nuclear Information System (INIS)

    Souza, Manoelito Martins de

    1994-01-01

    Full text: In a Causality Preserving Manifold Formalism, (CPMF), which is based on a model of spacetime with geometric and strict implementation of causality, masses are consequences of the spacetime symmetries. The mass spectrum of a set of non Abelian fields is solely determined from its Lagrangian kinematics term, in a way independent of any kind of interactions and without any extra field (no Higgs, no Yukawa coupling). The origin and meaning of mass in this formalism is discussed and then illustrated with the vector boson sector of the standard SU(2)x U(1) electroweak theory. (author)

  14. On the origin of mass and the electroweak mass spectrum without Higgs

    International Nuclear Information System (INIS)

    Souza, Manoelita Martins

    1995-01-01

    In a Causality Preserving Manifold Formalism (CPMF), which is based on a new model of spacetime, masses are consequences of spacetime structure symmetries. The mass spectrum of a set of non Abelian fields is solely determined from its Lagrangian kinematic term, in a way independent of any kind of interactions and without any extra field (no Higgs, no Yukawa couplings etc). After a brief review about this CPMF, the origin and meaning of mass is discussed and then illustrated with the vector boson sector of the SU(2) x U(1) electroweak theory. (author)

  15. Parameters of the lowest order chiral Lagrangian from fermion eigenvalues

    International Nuclear Information System (INIS)

    DeGrand, T.; Schaefer, S.

    2007-08-01

    Recent advances in Random Matrix Theory enable one to determine the pseudoscalar decay constant from the response of eigenmodes of quenched fermions to an imaginary isospin chemical potential. We perform a pilot test of this idea, from simulations with two flavors of dynamical overlap fermions. (orig.)

  16. Baryon and lepton number violation in the electroweak theory at TeV energies

    International Nuclear Information System (INIS)

    Mottola, E.

    1990-01-01

    In the standard Weinberg-Salam electroweak theory baryon and lepton number (B and L) are NOT exactly conserved. The nonconservation of B and L can be traced to the existence of parity violation in the electroweak theory, together with the chiral current anomaly. This subtle effect gives negligibly small amplitudes for B and L violation at energies and temperatures significantly smaller than M w sin 2 θ w /α ∼ 10 TeV. However, recent theoretical work shows that the rate for B and L nonconservation is unsuppressed at higher energies. The consequences of this for cosmology and the baryon asymmetry of the universe, as well as the prospects for direct verification at the SSC are discussed. 13 refs., 3 figs

  17. Lagrangian vector field and Lagrangian formulation of partial differential equations

    Directory of Open Access Journals (Sweden)

    M.Chen

    2005-01-01

    Full Text Available In this paper we consider the Lagrangian formulation of a system of second order quasilinear partial differential equations. Specifically we construct a Lagrangian vector field such that the flows of the vector field satisfy the original system of partial differential equations.

  18. Top down electroweak dipole operators

    Science.gov (United States)

    Fuyuto, Kaori; Ramsey-Musolf, Michael

    2018-06-01

    We derive present constraints on, and prospective sensitivity to, the electric dipole moment (EDM) of the top quark (dt) implied by searches for the EDMs of the electron and nucleons. Above the electroweak scale v, the dt arises from two gauge invariant operators generated at a scale Λ ≫ v that also mix with the light fermion EDMs under renormalization group evolution at two-loop order. Bounds on the EDMs of first generation fermion systems thus imply bounds on |dt |. Working in the leading log-squared approximation, we find that the present upper bound on |dt | is 10-19 e cm for Λ = 1 TeV, except in regions of finely tuned cancellations that allow for |dt | to be up to fifty times larger. Future de and dn probes may yield an order of magnitude increase in dt sensitivity, while inclusion of a prospective proton EDM search may lead to an additional increase in reach.

  19. Baryogenesis at the electroweak scale

    International Nuclear Information System (INIS)

    Dine, M.; Huet, P.; Singleton, R. Jr.

    1992-01-01

    We explore some issues involved in generating the baryon asymmetry at the electroweak scale. A simple two-dimensional model is analyzed which illustrates the role of the effective action in computing the asymmetry. We stress the fact that baryon production ceases at a very small value of the Higgs field; as a result, certain two-Higgs models which have been studied recently cannot produce sufficient asymmetry, while quite generally models with only doublets can barely produce the observed baryon density; models with gauge singlets are more promising. We also review limits on Higgs masses coming from the requirement that the baryon asymmetry not be wiped out after the phase transition. We note that there are a variety of uncertainties in these calculations, and that even in models with a single Higgs doublet one cannot rule out a Higgs mass below 55 GeV. (orig.)

  20. SU(3) chiral symmetry for baryons

    International Nuclear Information System (INIS)

    Dmitrasinovic, V.

    2011-01-01

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

  1. Non-linear effective Lagrangian treatment of 'Penguin' interaction

    International Nuclear Information System (INIS)

    Pham, T.N.

    1984-01-01

    Using the non-linear effective lagrangian technique, we show explicitly that only derivative coupling is allowed for the K - π, K -> 2 π and K -> 3 π transitions induced by the ΔS = 1 Penguin operator of SVZ in agreement with chiral symmetry requirements. From a derivative coupling (3, anti 3) mass term and the SU(3) breaking effect for fsub(K)/fsub(π), we estimate the strength of the Penguin interactions and find it too small to account for the ΔI = 1/2 amplitude. (orig.)

  2. Chiral symmetry and chiral-symmetry breaking

    International Nuclear Information System (INIS)

    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

  3. A three-flavor chiral effective model with four baryonic multiplets within the mirror assignment

    Energy Technology Data Exchange (ETDEWEB)

    Olbrich, Lisa; Zetenyi, Miklos; Giacosa, Francesco; Rischke, Dirk H. [Institute for Theoretical Physics, Goethe University Frankfurt am Main (Germany)

    2016-07-01

    Chiral symmetry requires the existence of chiral partners in the hadronic mass spectrum. In this talk, we address the question which is the chiral partner of the nucleon. We employ a chirally symmetric linear sigma model, where hadrons and their chiral partners are treated on the same footing. We construct four spin-1/2 baryon multiplets from left- and right-handed quarks as well as left- and right-handed diquarks. Two of these multiplets transform in a ''mirror'' way, which allows for chirally invariant mass terms. We then embed these baryonic multiplets into the Lagrangian of the extended Linear Sigma Model, which features (pseudo)scalar and (axial-)vector mesons, as well as glueballs. Reducing the Lagrangian to the two-flavor case, we obtain four doublets of nucleonic states. These mix to produce the positive-parity nucleon N(939) and the Roper resonance N(1440), as well as the negative-parity resonances N(1535) and N(1650). We determine the parameters of the nucleonic part of the Lagrangian from a fit to masses and decay properties of these states. Studying the limit of vanishing quark condensate, we conclude that N(939) and N(1535), as well as N(1440) and N(1650) form pairs of chiral partners.

  4. Leading order relativistic chiral nucleon-nucleon interaction

    Science.gov (United States)

    Ren, Xiu-Lei; Li, Kai-Wen; Geng, Li-Sheng; Long, Bingwei; Ring, Peter; Meng, Jie

    2018-01-01

    Motivated by the successes of relativistic theories in studies of atomic/molecular and nuclear systems and the need for a relativistic chiral force in relativistic nuclear structure studies, we explore a new relativistic scheme to construct the nucleon-nucleon interaction in the framework of covariant chiral effective field theory. The chiral interaction is formulated up to leading order with covariant power counting and a Lorentz invariant chiral Lagrangian. We find that the relativistic scheme induces all six spin operators needed to describe the nuclear force. A detailed investigation of the partial wave potentials shows a better description of the {}1S0 and {}3P0 phase shifts than the leading order Weinberg approach, and similar to that of the next-to-leading order Weinberg approach. For the other partial waves with angular momenta J≥slant 1, the relativistic results are almost the same as their leading order non-relativistic counterparts. )

  5. Dynamics of chiral oscillations: a comparative analysis with spin flipping

    International Nuclear Information System (INIS)

    Bernardini, A E

    2006-01-01

    Chiral oscillation as well as spin flipping effects correspond to quantum phenomena of fundamental importance in the context of particle physics and, in particular, of neutrino physics. From the point of view of first quantized theories, we are specifically interested in pointing out the differences between chirality and helicity by obtaining their dynamic equations for a fermionic Dirac-type particle (neutrino). We also identify both effects when the non-minimal coupling with an external (electro)magnetic field in the neutrino interacting Lagrangian is taken into account. We demonstrate that, however, there is no constraint between chiral oscillations, when it takes place in vacuum, and the process of spin flipping related to the helicity quantum number, which does not take place in vacuum. To conclude, we show that the origin of chiral oscillations (in vacuum) can be interpreted as projections of very rapid oscillations of position onto the longitudinal direction of momentum

  6. Nucleon and delta masses in twisted mass chiral perturbation theory

    International Nuclear Information System (INIS)

    Walker-Loud, Andre; Wu, Jackson M.S.

    2005-01-01

    We calculate the masses of the nucleons and deltas in twisted mass heavy baryon chiral perturbation theory. We work to quadratic order in a power counting scheme in which we treat the lattice spacing, a, and the quark masses, m q , to be of the same order. We give expressions for the mass and the mass splitting of the nucleons and deltas both in and away from the isospin limit. We give an argument using the chiral Lagrangian treatment that, in the strong isospin limit, the nucleons remain degenerate and the delta multiplet breaks into two degenerate pairs to all orders in chiral perturbation theory. We show that the mass splitting between the degenerate pairs of the deltas first appears at quadratic order in the lattice spacing. We discuss the subtleties in the effective chiral theory that arise from the inclusion of isospin breaking

  7. New strong interactions above the electroweak scale

    International Nuclear Information System (INIS)

    White, A.R.

    1994-01-01

    Theoretical arguments for a new higher-color quark sector, based on Pomeron physics in QCD, are briefly described. The electroweak symmetry-breaking, Strong CP conservation, and electroweak scale CP violation, that is naturally produced by this sector is also outlined. A further consequence is that above the electroweak scale there will be a radical change in the strong interaction. Electroweak states, in particular multiple W's and Z's, and new, semi-stable, very massive, baryons, will be commonly produced. The possible correlation of expected phenomena with a wide range of observed Cosmic Ray effects at and above the primary spectrum knee is described. Related phenomena that might be seen in the highest energy hard scattering events at the Fermilab Tevatron, some of which could be confused with top production, are also briefly discussed

  8. Introduction to gauge theories of electroweak interactions

    International Nuclear Information System (INIS)

    Ecker, G.

    1982-01-01

    The author presents an introduction to electroweak gauge theories. Emphasis is placed on the properties of a general gauge theory. The standard model is discussed as the simplest example to illustrate these properties. (G.T.H.)

  9. Electroweak baryogenesis and low energy supersymmetry

    CERN Document Server

    Carena, M S; Riotto, Antonio; Vilja, I; Wagner, C E M

    1997-01-01

    Electroweak baryogenesis is an interesting theoretical scenario, which demands physics beyond the Standard Model at energy scales of the order of the weak boson masses. It has been recently emphasized that, in the presence of light stops, the electroweak phase transition can be strongly first order, opening the window for electroweak baryogenesis in the MSSM. For the realization of this scenario, the Higgs boson must be light, at the reach of the LEP2 collider. In this article, we compute the baryon asymmetry assuming the presence of non-trivial CP violating phases in the parameters associated with the left-right stop mixing term and the Higgsino mass $\\mu$. We conclude that a phase $|\\sin \\phi_{\\mu}| > 0.01$ and Higgsino and gaugino mass parameters $|\\mu| \\simeq M_2$, and of the order of the electroweak scale, are necessary in order to generate the observed baryon asymmetry.

  10. An electroweak enigma: Hyperon radiative decays

    Energy Technology Data Exchange (ETDEWEB)

    Vorobyov, A., (spokesperson); /St. Petersburg, INP; Jastrzembski, E.; Lach, J.; Marriner, J.; /Fermilab; Golovtsov, V.; Krivshich, A.; Schegelsky, V.; Smirnov, N.; Terentiev, N.K.; Uvarov, L.; /St. Petersburg, INP; McCliment, E.; Newsom, C.; Norbeck, E.; /Iowa U.; Cooper, P.S.; /Yale U.

    1985-04-03

    The main thrust of this experiment will be to measure the asymmetry parameter for the electroweak decay {Sigma}{sup +} {yields} p{gamma} and verify its branching ratio. As a secondary goal they will measure, or set new upper limits for, the branching ratio of the electroweak decay {Xi}{sup -} {yields} {Sigma}{sup -}{gamma}. Since the {Xi}{sup -} are expected to be polarized, information on the asymmetry parameter may also be available.

  11. Non-negligible electroweak penguin effects

    International Nuclear Information System (INIS)

    Guo Libo; Li Xingyi

    1999-01-01

    Starting from the leading logarithmic low energy effective Hamiltonian and the Bauer-Stech-Wirbe (BSW) model, the authors calculate the electroweak penguin effects in the two-body hadronic pure penguin processes of B-meson. In the case of B→PP and PV decay, the authors find that the processes involving external penguin diagrams receive large contribution from electroweak penguin effects which can even play dominant role

  12. Electroweak boson production with jets at CMS

    CERN Document Server

    Hortiangtham, Apichart

    2017-01-01

    The production of electroweak bosons (W, Z or gamma) in association with jets is a stringent test of perturbative QCD and is a background process in searches for new physics. Total and differential cross-section measurements of electroweak bosons produced in association with jets (and heavy flavour quarks) in proton-proton collisions are presented. The data have been recorded with the CMS detector at the LHC and are compared to the predictions of event generators and theoretical calculations.

  13. Algebra of strong and electroweak interactions

    International Nuclear Information System (INIS)

    Bolokhov, S.V.; Vladimirov, Yu.S.

    2004-01-01

    The algebraic approach to describing the electroweak and strong interactions is considered within the frames of the binary geometrophysics, based on the principles of the Fokker-Feynman direct interparticle interaction theories of the Kaluza-Klein multidimensional geometrical models and the physical structures theory. It is shown that in this approach the electroweak and strong elementary particles interaction through the intermediate vector bosons, are characterized by the subtypes of the algebraic classification of the complex 3 x 3-matrices [ru

  14. A practical introduction to electroweak radiative corrections

    International Nuclear Information System (INIS)

    Drees, M.

    1991-05-01

    This is a brief introduction into electroweak radiative corrections within the Standard Model, with the emphasis on performing actual calculations. To this end, a complete set of expressions is given that allows the computation of the ρ parameter, the W mass, and Z→fanti f decays for massless fermions, where the anti Manti S scheme has been used. I conclude with an assessment of what we have learned so far from electroweak precision experiments, and a brief outlook. (orig.)

  15. Electroweak measurements with the ATLAS detector

    CERN Document Server

    Krasnopevtsev, Dimitriy; The ATLAS collaboration

    2015-01-01

    Electroweak measurements with the ATLAS detector -First Run 2 measurements of electroweak processes -Run 1 measurements of SM parameters, i.e. W mass and weak mixing angle -Recent Run 1 measurements of di- and multi-boson production cross-sections as well as vector boson fusion and scattering processes at 8 TeV -Recent Run 1 measurements of exclusive di-lepton and WW production

  16. Chiral mirrors

    International Nuclear Information System (INIS)

    Plum, Eric; Zheludev, Nikolay I.

    2015-01-01

    Mirrors are used in telescopes, microscopes, photo cameras, lasers, satellite dishes, and everywhere else, where redirection of electromagnetic radiation is required making them arguably the most important optical component. While conventional isotropic mirrors will reflect linear polarizations without change, the handedness of circularly polarized waves is reversed upon reflection. Here, we demonstrate a type of mirror reflecting one circular polarization without changing its handedness, while absorbing the other. The polarization-preserving mirror consists of a planar metasurface with a subwavelength pattern that cannot be superimposed with its mirror image without being lifted out of its plane, and a conventional mirror spaced by a fraction of the wavelength from the metasurface. Such mirrors enable circularly polarized lasers and Fabry-Pérot cavities with enhanced tunability, gyroscopic applications, polarization-sensitive detectors of electromagnetic waves, and can be used to enhance spectroscopies of chiral media

  17. Distinguishing standard model extensions using monotop chirality at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Allahverdi, Rouzbeh [Department of Physics and Astronomy, University of New Mexico,Albuquerque, NM 87131 (United States); Dalchenko, Mykhailo; Dutta, Bhaskar [Department of Physics and Astronomy,Mitchell Institute for Fundamental Physics and Astronomy, Texas A& M University,College Station, TX 77843-4242 (United States); Flórez, Andrés [Departamento de Física, Universidad de los Andes,Bogotá, Carrera 1 18A-10, Bloque IP (Colombia); Gao, Yu [Department of Physics and Astronomy,Mitchell Institute for Fundamental Physics and Astronomy, Texas A& M University,College Station, TX 77843-4242 (United States); Kamon, Teruki [Department of Physics and Astronomy,Mitchell Institute for Fundamental Physics and Astronomy, Texas A& M University,College Station, TX 77843-4242 (United States); Department of Physics, Kyungpook National University,Daegu 702-701 (Korea, Republic of); Kolev, Nikolay [Department of Physics, University of Regina,SK, S4S 0A2 (Canada); Mueller, Ryan [Department of Physics and Astronomy,Mitchell Institute for Fundamental Physics and Astronomy, Texas A& M University,College Station, TX 77843-4242 (United States); Segura, Manuel [Departamento de Física, Universidad de los Andes,Bogotá, Carrera 1 18A-10, Bloque IP (Colombia)

    2016-12-13

    We present two minimal extensions of the standard model, each giving rise to baryogenesis. They include heavy color-triplet scalars interacting with a light Majorana fermion that can be the dark matter (DM) candidate. The electroweak charges of the new scalars govern their couplings to quarks of different chirality, which leads to different collider signals. These models predict monotop events at the LHC and the energy spectrum of decay products of highly polarized top quarks can be used to establish the chiral nature of the interactions involving the heavy scalars and the DM. Detailed simulation of signal and standard model background events is performed, showing that top quark chirality can be distinguished in hadronic and leptonic decays of the top quarks.

  18. Neutrinoless double beta decay in chiral effective field theory: lepton number violation at dimension seven

    Science.gov (United States)

    Cirigliano, V.; Dekens, W.; de Vries, J.; Graesser, M. L.; Mereghetti, E.

    2017-12-01

    We analyze neutrinoless double beta decay (0 νββ) within the framework of the Standard Model Effective Field Theory. Apart from the dimension-five Weinberg operator, the first contributions appear at dimension seven. We classify the operators and evolve them to the electroweak scale, where we match them to effective dimension-six, -seven, and -nine operators. In the next step, after renormalization group evolution to the QCD scale, we construct the chiral Lagrangian arising from these operators. We develop a power-counting scheme and derive the two-nucleon 0 νββ currents up to leading order in the power counting for each lepton-number-violating operator. We argue that the leading-order contribution to the decay rate depends on a relatively small number of nuclear matrix elements. We test our power counting by comparing nuclear matrix elements obtained by various methods and by different groups. We find that the power counting works well for nuclear matrix elements calculated from a specific method, while, as in the case of light Majorana neutrino exchange, the overall magnitude of the matrix elements can differ by factors of two to three between methods. We calculate the constraints that can be set on dimension-seven lepton-number-violating operators from 0 νββ experiments and study the interplay between dimension-five and -seven operators, discussing how dimension-seven contributions affect the interpretation of 0 νββ in terms of the effective Majorana mass m ββ .

  19. Lagrangian averaging with geodesic mean.

    Science.gov (United States)

    Oliver, Marcel

    2017-11-01

    This paper revisits the derivation of the Lagrangian averaged Euler (LAE), or Euler- α equations in the light of an intrinsic definition of the averaged flow map as the geodesic mean on the volume-preserving diffeomorphism group. Under the additional assumption that first-order fluctuations are statistically isotropic and transported by the mean flow as a vector field, averaging of the kinetic energy Lagrangian of an ideal fluid yields the LAE Lagrangian. The derivation presented here assumes a Euclidean spatial domain without boundaries.

  20. The serendipity of electroweak baryogenesis

    Science.gov (United States)

    Servant, Géraldine

    2018-01-01

    The origin of the matter-antimatter asymmetry of the universe remains unexplained in the Standard Model (SM) of particle physics. The origin of the flavour structure is another major puzzle of the theory. In this article, we report on recent work attempting to link the two themes through the appealing framework of electroweak (EW) baryogenesis. We show that Yukawa couplings of SM fermions can be the source of CP violation for EW baryogenesis if they vary at the same time as the Higgs is acquiring its vacuum expectation value, offering new avenues for EW baryogenesis. The advantage of this approach is that it circumvents the usual severe bounds from electric dipole moments. These ideas apply if the mechanism explaining the flavour structure of the SM is connected to EW symmetry breaking, as motivated for instance in Randall-Sundrum or Composite Higgs models. We compute the resulting baryon asymmetry for different configurations of the Yukawa coupling variation across the bubble wall and show that it can naturally be of the right order. This article is part of the Theo Murphy meeting issue `Higgs cosmology'.

  1. BREM5 electroweak Monte Carlo

    International Nuclear Information System (INIS)

    Kennedy, D.C. II.

    1987-01-01

    This is an update on the progress of the BREMMUS Monte Carlo simulator, particularly in its current incarnation, BREM5. The present report is intended only as a follow-up to the Mark II/Granlibakken proceedings, and those proceedings should be consulted for a complete description of the capabilities and goals of the BREMMUS program. The new BREM5 program improves on the previous version of BREMMUS, BREM2, in a number of important ways. In BREM2, the internal loop (oblique) corrections were not treated in consistent fashion, a deficiency that led to renormalization scheme-dependence; i.e., physical results, such as cross sections, were dependent on the method used to eliminate infinities from the theory. Of course, this problem cannot be tolerated in a Monte Carlo designed for experimental use. BREM5 incorporates a new way of treating the oblique corrections, as explained in the Granlibakken proceedings, that guarantees renormalization scheme-independence and dramatically simplifies the organization and calculation of radiative corrections. This technique is to be presented in full detail in a forthcoming paper. BREM5 is, at this point, the only Monte Carlo to contain the entire set of one-loop corrections to electroweak four-fermion processes and renormalization scheme-independence. 3 figures

  2. Fermions on the electroweak string

    CERN Document Server

    Moreno, J M; Quirós, Mariano; Moreno, J M; Oaknin, D H; Quiros, M

    1995-01-01

    We construct a simple class of exact solutions of the electroweak theory including the naked Z--string and fermion fields. It consists in the Z--string configuration (\\phi,Z_\\theta), the {\\it time} and z components of the neutral gauge bosons (Z_{0,3},A_{0,3}) and a fermion condensate (lepton or quark) zero mode. The Z--string is not altered (no feed back from the rest of fields on the Z--string) while fermion condensates are zero modes of the Dirac equation in the presence of the Z--string background (no feed back from the {\\it time} and z components of the neutral gauge bosons on the fermion fields). For the case of the n--vortex Z--string the number of zero modes found for charged leptons and quarks is (according to previous results by Jackiw and Rossi) equal to |n|, while for (massless) neutrinos is |n|-1. The presence of fermion fields in its core make the obtained configuration a superconducting string, but their presence (as well as that of Z_{0,3},A_{0,3}) does not enhance the stability of the Z--stri...

  3. The serendipity of electroweak baryogenesis.

    Science.gov (United States)

    Servant, Géraldine

    2018-03-06

    The origin of the matter-antimatter asymmetry of the universe remains unexplained in the Standard Model (SM) of particle physics. The origin of the flavour structure is another major puzzle of the theory. In this article, we report on recent work attempting to link the two themes through the appealing framework of electroweak (EW) baryogenesis. We show that Yukawa couplings of SM fermions can be the source of CP violation for EW baryogenesis if they vary at the same time as the Higgs is acquiring its vacuum expectation value, offering new avenues for EW baryogenesis. The advantage of this approach is that it circumvents the usual severe bounds from electric dipole moments. These ideas apply if the mechanism explaining the flavour structure of the SM is connected to EW symmetry breaking, as motivated for instance in Randall-Sundrum or Composite Higgs models. We compute the resulting baryon asymmetry for different configurations of the Yukawa coupling variation across the bubble wall and show that it can naturally be of the right order.This article is part of the Theo Murphy meeting issue 'Higgs cosmology'. © 2018 The Author(s).

  4. Need for spontaneous breakdown of chiral symmetry

    International Nuclear Information System (INIS)

    Salomone, A.; Schechter, J.; Tudron, T.

    1981-01-01

    The question of whether the chiral symmetry of the theory of strong interactions (with massless quarks) is required to be spontaneously broken is examined in the framework of a previously discussed effective Lagrangian for quantum chromodynamics. The assumption that physical masses of the theory be finite leads in a very direct way to the necessity of spontaneous breakdown. This result holds for all N/sub F/> or =2, where N/sub F/ is the number of different flavors of light quarks. The atypical cases N/sub F/ = 1,2 are discussed separately

  5. On meson resonances and chiral symmetry

    International Nuclear Information System (INIS)

    Lutz, M.F.M.

    2003-07-01

    We study meson resonances with quantum numbers J P = 1 + in terms of the chiral SU(3) Lagrangian. At leading order a parameter-free prediction is obtained for the scattering of Goldstone bosons off vector mesons with J P = 1 - once we insist on approximate crossing symmetry of the unitarized scattering amplitude. A resonance spectrum arises that is remarkably close to the empirical pattern. In particular, we find that the strangeness-zero resonances h 1 (1380), f 1 (1285) and b 1 (1235) are formed due to strong K anti K μ and K K μ channels. This leads to large coupling constants of those resonances to the latter states. (orig.)

  6. A chiral model for excited pions

    International Nuclear Information System (INIS)

    Volkov, M.K.; Weiss, C.

    1996-01-01

    We study radially excited mesons (π', σ') in a simple extension of the Nambu-Jona-Lasinio model with a polynomial meson-quark form factor. The form factor is introduced so that the usual form of the NJL gap equation remains unchanged. We derive the effective Lagrangian for π- and π'-mesons which describes the decoupling of the Goldstone pion in the chiral limit in agreement with current algebra. For π' masses in the range of 750 MeV and 1300 MeV f π' /f π is found to be of an order of one per cent. 12 refs

  7. A primer for Chiral Perturbative Theory

    International Nuclear Information System (INIS)

    Scherer, Stefan; Schindler, Matthias R.; George Washington Univ., Washington, DC

    2012-01-01

    Chiral Perturbation Theory, as effective field theory, is a commonly accepted and well established working tool, approximating quantum chromodynamics at energies well below typical hadron masses. This volume, based on a number of lectures and supplemented with additional material, provides a pedagogical introduction for graduate students and newcomers entering the field from related areas of nuclear and particle physics. Starting with the the Lagrangian of the strong interactions and general symmetry principles, the basic concepts of Chiral Perturbation Theory in the mesonic and baryonic sectors are developed. The application of these concepts is then illustrated with a number of examples. A large number of exercises (81, with complete solutions) are included to familiarize the reader with helpful calculational techniques. (orig.)

  8. A primer for chiral perturbation theory

    CERN Document Server

    Scherer, Stefan

    2012-01-01

    Chiral Perturbation Theory, as effective field theory, is a commonly accepted and well established working tool, approximating quantum chromodynamics at energies well below typical hadron masses. This volume, based on a number of lectures and supplemented with additional material, provides a pedagogical introduction for graduate students and newcomers entering the field from related areas of nuclear and particle physics. Starting with the the Lagrangian of the strong interactions and general symmetry principles, the basic concepts of Chiral Perturbation Theory in the mesonic and baryonic sectors are developed. The application of these concepts is then illustrated with a number of examples. A large number of exercises (81, with complete solutions) are included to familiarize the reader with helpful calculational techniques.

  9. Scattering of decuplet baryons in chiral effective field theory

    Energy Technology Data Exchange (ETDEWEB)

    Haidenbauer, J. [Institut fuer Kernphysik, Institute for Advanced Simulation and Juelich Center for Hadron Physics, Juelich (Germany); Petschauer, S.; Kaiser, N.; Weise, W. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Meissner, Ulf G. [Institut fuer Kernphysik, Institute for Advanced Simulation and Juelich Center for Hadron Physics, Juelich (Germany); Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany)

    2017-11-15

    A formalism for treating the scattering of decuplet baryons in chiral effective field theory is developed. The minimal Lagrangian and potentials in leading-order SU(3) chiral effective field theory for the interactions of octet baryons (B) and decuplet baryons (D) for the transitions BB → BB, BB <-> DB, DB → DB, BB <-> DD, DB <-> DD, and DD → DD are provided. As an application of the formalism we compare with results from lattice QCD simulations for ΩΩ and NΩ scattering. Implications of our results pertinent to the quest for dibaryons are discussed. (orig.)

  10. Weyl's Lagrangian in teleparallel form

    International Nuclear Information System (INIS)

    Burnett, James; Vassiliev, Dmitri

    2009-01-01

    The Weyl Lagrangian is the massless Dirac Lagrangian. The dynamical variable in the Weyl Lagrangian is a spinor field. We provide a mathematically equivalent representation in terms of a different dynamical variable - the coframe (an orthonormal tetrad of covector fields). We show that when written in terms of this dynamical variable, the Weyl Lagrangian becomes remarkably simple: it is the wedge product of axial torsion of the teleparallel connection with a teleparallel lightlike element of the coframe. We also examine the issues of U(1)-invariance and conformal invariance. Examination of the latter motivates us to introduce a positive scalar field (equivalent to a density) as an additional dynamical variable; this makes conformal invariance self-evident.

  11. Lagrangian postprocessing of computational hemodynamics.

    Science.gov (United States)

    Shadden, Shawn C; Arzani, Amirhossein

    2015-01-01

    Recent advances in imaging, modeling, and computing have rapidly expanded our capabilities to model hemodynamics in the large vessels (heart, arteries, and veins). This data encodes a wealth of information that is often under-utilized. Modeling (and measuring) blood flow in the large vessels typically amounts to solving for the time-varying velocity field in a region of interest. Flow in the heart and larger arteries is often complex, and velocity field data provides a starting point for investigating the hemodynamics. This data can be used to perform Lagrangian particle tracking, and other Lagrangian-based postprocessing. As described herein, Lagrangian methods are necessary to understand inherently transient hemodynamic conditions from the fluid mechanics perspective, and to properly understand the biomechanical factors that lead to acute and gradual changes of vascular function and health. The goal of the present paper is to review Lagrangian methods that have been used in post-processing velocity data of cardiovascular flows.

  12. Quadratic Lagrangians and Legendre transformation

    International Nuclear Information System (INIS)

    Magnano, G.

    1988-01-01

    In recent years interest is grown about the so-called non-linear Lagrangians for gravitation. In particular, the quadratic lagrangians are currently believed to play a fundamental role both for quantum gravity and for the super-gravity approach. The higher order and high degree of non-linearity of these theories make very difficult to extract physical information out of them. The author discusses how the Legendre transformation can be applied to a wide class of non-linear theories: it corresponds to a conformal transformation whenever the Lagrangian depends only on the scalar curvature, while it has a more general form if the Lagrangian depends on the full Ricci tensor

  13. Chiral Magnetic Spirals

    International Nuclear Information System (INIS)

    Basar, Goekce; Dunne, Gerald V.; Kharzeev, Dmitri E.

    2010-01-01

    We argue that the presence of a very strong magnetic field in the chirally broken phase induces inhomogeneous expectation values, of a spiral nature along the magnetic field axis, for the currents of charge and chirality, when there is finite baryon density or an imbalance between left and right chiralities. This 'chiral magnetic spiral' is a gapless excitation transporting the currents of (i) charge (at finite chirality), and (ii) chirality (at finite baryon density) along the direction of the magnetic field. In both cases it also induces in the transverse directions oscillating currents of charge and chirality. In heavy ion collisions, the chiral magnetic spiral possibly provides contributions both to the out-of-plane and the in-plane dynamical charge fluctuations recently observed at BNL RHIC.

  14. Low temperature electroweak phase transition in the Standard Model with hidden scale invariance

    Directory of Open Access Journals (Sweden)

    Suntharan Arunasalam

    2018-01-01

    Full Text Available We discuss a cosmological phase transition within the Standard Model which incorporates spontaneously broken scale invariance as a low-energy theory. In addition to the Standard Model fields, the minimal model involves a light dilaton, which acquires a large vacuum expectation value (VEV through the mechanism of dimensional transmutation. Under the assumption of the cancellation of the vacuum energy, the dilaton develops a very small mass at 2-loop order. As a result, a flat direction is present in the classical dilaton-Higgs potential at zero temperature while the quantum potential admits two (almost degenerate local minima with unbroken and broken electroweak symmetry. We found that the cosmological electroweak phase transition in this model can only be triggered by a QCD chiral symmetry breaking phase transition at low temperatures, T≲132 MeV. Furthermore, unlike the standard case, the universe settles into the chiral symmetry breaking vacuum via a first-order phase transition which gives rise to a stochastic gravitational background with a peak frequency ∼10−8 Hz as well as triggers the production of approximately solar mass primordial black holes. The observation of these signatures of cosmological phase transitions together with the detection of a light dilaton would provide a strong hint of the fundamental role of scale invariance in particle physics.

  15. Breaking of electroweak symmetry: origin and effects

    International Nuclear Information System (INIS)

    Delaunay, C.

    2008-10-01

    The Higgs boson appears as the corner stone of high energy physics, it might be the cause of the excess of matter that led to the formation of the structures of the universe and it seems that it drives the breaking of the electroweak symmetry. Moreover, when the stability at low energies of the Higgs boson is assured by an extra space dimension, it appears that this extra dimension can explain most issues in the flavor physics that are not understood by the standard model. The first chapter presents the main tools of effective field theories, the role of experimental data in the construction of theories valid beyond the standard model is discussed. The second chapter focuses on the electroweak baryogenesis that allows the testing of new physics via the electroweak phase transition. We detail the calculation of a Higgs potential at finite temperature. We follow the dynamics of the phase transition including nucleation an supercooling. Finally we investigate the prospects of gravity wave detection to see the effects of a strong electroweak phase transition. The 2 last chapters are dedicated to the physics of extra-dimension. The properties of the dynamics of scalar, vector fields with a 1/2 spin plunged in a 5 d. Anti de Sitter geometry are reviewed. We present a model of lepton masses and mixings based on the A 4 non-Abelian discrete symmetry. It is shown that this model does not contradict the tests of electroweak precision. (A.C.)

  16. Introduction to Chiral Symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Volker [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-05-09

    These lectures are an attempt to a pedagogical introduction into the elementary concepts of chiral symmetry in nuclear physics. We will also discuss some effective chiral models such as the linear and nonlinear sigma model as well as the essential ideas of chiral perturbation theory. We will present some applications to the physics of ultrarelativistic heavy ion collisionsd.

  17. Introduction to chiral symmetry

    International Nuclear Information System (INIS)

    Koch, V.

    1996-01-01

    These lectures are an attempt to a pedagogical introduction into the elementary concepts of chiral symmetry in nuclear physics. Effective chiral models such as the linear and nonlinear sigma model will be discussed as well as the essential ideas of chiral perturbation theory. Some applications to the physics of ultrarelativistic heavy ion collisions will be presented

  18. Relaxation of the chiral imbalance and the generation of magnetic fields in magnetars

    Energy Technology Data Exchange (ETDEWEB)

    Dvornikov, M. S., E-mail: maxdvo@izmiran.ru [Ionosphere and Radiowave Propagation (IZMIRAN), Pushkov Institute of Terrestrial Magnetism (Russian Federation)

    2016-12-15

    The model for the generation of magnetic fields in a neutron star, based on the magnetic field instability caused by the electroweak interaction between electrons and nucleons, is developed. Using the methods of the quantum field theory, the helicity flip rate of electrons in their scattering off protons in dense matter of a neutron star is calculated. The influence of the electroweak interaction between electrons and background nucleons on the process of the helicity flip is studied. The kinetic equation for the evolution of the chiral imbalance is derived. The obtained results are applied for the description of the magnetic fields evolution in magnetars.

  19. Chiral discotics; expression and amplification of chirality

    NARCIS (Netherlands)

    Brunsveld, L.; Meijer, E.W.; Rowan, A.E.; Nolte, R.J.M.; Denmark, S.E.; Nolte, R.J.M.; Meijer, E.W.

    2003-01-01

    In this contribution, chirality and discotic liquid crystals are discussed as a tool for studying the self-assembly of these molecules, both in solution and in the solid state. Therefore, the objective of this chapter is to summarize and elucidate how molecular chirality can be expressed in discotic

  20. Chiral symmetry and many-body forces in nuclei

    International Nuclear Information System (INIS)

    Nyman, E.M.; Rho, M.

    1976-01-01

    It is demonstrated that when quantum corrections are added, chiral Lagrangians need not generate strong many-body forces as they do in tree approximation. It is suggested that a physically reasonable procedure is to adjust the sigma-model parameters so as not to conflict with the current status of nuclear theory. As a consequence, the equilibrium density of abnormal states could be pushed up further, and the binding energy be considerably reduced. (Auth.)

  1. Emergent chirality in the electric polarization texture of titanate superlattices.

    Science.gov (United States)

    Shafer, Padraic; García-Fernández, Pablo; Aguado-Puente, Pablo; Damodaran, Anoop R; Yadav, Ajay K; Nelson, Christopher T; Hsu, Shang-Lin; Wojdeł, Jacek C; Íñiguez, Jorge; Martin, Lane W; Arenholz, Elke; Junquera, Javier; Ramesh, Ramamoorthy

    2018-01-30

    Chirality is a geometrical property by which an object is not superimposable onto its mirror image, thereby imparting a handedness. Chirality determines many important properties in nature-from the strength of the weak interactions according to the electroweak theory in particle physics to the binding of enzymes with naturally occurring amino acids or sugars, reactions that are fundamental for life. In condensed matter physics, the prediction of topologically protected magnetic skyrmions and related spin textures in chiral magnets has stimulated significant research. If the magnetic dipoles were replaced by their electrical counterparts, then electrically controllable chiral devices could be designed. Complex oxide BaTiO 3 /SrTiO 3 nanocomposites and PbTiO 3 /SrTiO 3 superlattices are perfect candidates, since "polar vortices," in which a continuous rotation of ferroelectric polarization spontaneously forms, have been recently discovered. Using resonant soft X-ray diffraction, we report the observation of a strong circular dichroism from the interaction between circularly polarized light and the chiral electric polarization texture that emerges in PbTiO 3 /SrTiO 3 superlattices. This hallmark of chirality is explained by a helical rotation of electric polarization that second-principles simulations predict to reside within complex 3D polarization textures comprising ordered topological line defects. The handedness of the texture can be topologically characterized by the sign of the helicity number of the chiral line defects. This coupling between the optical and novel polar properties could be exploited to encode chiral signatures into photon or electron beams for information processing.

  2. Opening the window for electroweak baryogenesis

    CERN Document Server

    Carena, M S; Wagner, C E M

    1996-01-01

    We perform an analysis of the behaviour of the electroweak phase transition in the Minimal Supersymmetric Standard Model, in the presence of light stops. We show that, in previously unexplored regions of parameter space, the order parameter v(T_c)/T_c can become significantly larger than one, for values of the Higgs and supersymmetric particle masses consistent with the present experimental bounds. This implies that baryon number can be efficiently generated at the electroweak phase transition. As a by-product of this study, we present an analysis of the problem of colour breaking minima at zero and finite temperature, and we use it to investigate the region of parameter space preferred by the best fit to the present precision electroweak measurement data, in which the left-handed stops are much heavier than the right-handed ones.

  3. The electroweak polarization asymmetry: A guided tour

    International Nuclear Information System (INIS)

    Kennedy, D.C.

    1988-10-01

    A comprehensive review is provided of the electroweak polarization asymmetry at the Z 0 , a highly accurate measure of the Z 0 coupling to fermions. Its significance as a precision test of the Standard Model is explored in detail. Emphasized are the role of electroweak symmetry-breaking and radiative corrections; the non-decoupling of new physics beyond the Z 0 ; and the testing of extensions of the Standard Model, such as supersymmetry, technicolor, new generations of fermions, grand unification, and new gauge forces. Also discussed are the relationship of the polarization asymmetry to other electroweak observables and its superiority to other Z 0 asymmetries. Experimental issues are briefly presented, stressing the importance of polarization at the SLC and LEP e + e - colliders. 42 refs., 13 figs., 2 tabs

  4. Workshop on electroweak symmetry breaking: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hinchliffe, I. (ed.)

    1984-10-01

    A theoretical workshop on electroweak symmetry breaking at the Superconducting Supercollider was held at Lawrence Berkeley Laboratory, June 4-22, 1984. The purpose of the workshop was to focus theoretical attention on the ways in which experimentation at the SSC could reveal manifestations of the phenomenon responsible for electroweak symmetry breaking. This issue represents, at present, the most compelling scientific argument for the need to explore the energy region to be made accessible by the SSC, and a major aim of the workshop was to involve a broad cross section of particle theorists in the ongoing process of sharpening the requirements for both accelerator and detector design that will ensure detection and identification of meaningful signals, whatever form the electroweak symmetry breaking phenomenon should actually take. Separate entries were prepared for the data base for the papers presented.

  5. Workshop on electroweak symmetry breaking: proceedings

    International Nuclear Information System (INIS)

    Hinchliffe, I.

    1984-10-01

    A theoretical workshop on electroweak symmetry breaking at the Superconducting Supercollider was held at Lawrence Berkeley Laboratory, June 4-22, 1984. The purpose of the workshop was to focus theoretical attention on the ways in which experimentation at the SSC could reveal manifestations of the phenomenon responsible for electroweak symmetry breaking. This issue represents, at present, the most compelling scientific argument for the need to explore the energy region to be made accessible by the SSC, and a major aim of the workshop was to involve a broad cross section of particle theorists in the ongoing process of sharpening the requirements for both accelerator and detector design that will ensure detection and identification of meaningful signals, whatever form the electroweak symmetry breaking phenomenon should actually take. Separate entries were prepared for the data base for the papers presented

  6. O(5) x U(1) electroweak theory

    International Nuclear Information System (INIS)

    Mukku, C.; Sayed, W.A.

    1980-12-01

    An anomaly free O(5) x U(1) theory of electroweak interactions is described which provides a unified description of electroweak phenomena for two families of standard leptons and quarks. No ''new'' non-sequential type fermions of the standard model are introduced as has been the case for all past studies based on this group. The present scheme requires the introduction of two further charged and three more neutral gauge fields over and above the Wsup(+-), Z and photon fields of SU(2) x U(1) giving rise to new neutral and charged currents. In this note we outline our reasons for proposing the present electroweak scheme, give the basic structure of the model, discuss the symmetry breaking pattern which ensures that SU(2)sub(L) x U(1) is the low energy symmetry, point out the new interactions present in the extended framework and obtain limits on the masses of all the gauge fields. (author)

  7. Low-energy Electro-weak Reactions

    International Nuclear Information System (INIS)

    Gazit, Doron

    2012-01-01

    Chiral effective field theory (EFT) provides a systematic and controlled approach to low-energy nuclear physics. Here, we use chiral EFT to calculate low-energy weak Gamow-Teller transitions. We put special emphasis on the role of two-body (2b) weak currents within the nucleus and discuss their applications in predicting physical observables.

  8. What's new with the electroweak phase transition?

    CERN Document Server

    Laine, M.

    1999-01-01

    We review the status of non-perturbative lattice studies of the electroweak phase transition. In the Standard Model, the complete phase diagram has been reliably determined, and the conclusion is that there is no phase transition at all for the experimentally allowed Higgs masses. In the Minimal Supersymmetric Standard Model (MSSM), in contrast, there can be a strong first order transition allowing for baryogenesis. Finally, we point out possibilities for future simulations, such as the problem of CP-violation at the MSSM electroweak phase boundary.

  9. Recent results on Electroweak measurements from ATLAS

    Directory of Open Access Journals (Sweden)

    Benekos Nektarios Chr.

    2015-01-01

    Full Text Available ATLAS measurements of multiboson production processes involving combinations of W,Z and isolated photons are summarized. Measurements using data at 7 TeV and at 8 TeV are presented. The measurements are performed using leptonic decay modes, including the invisible decay Z → v v̅, as well as semileptonic channels. Measurements of single and diboson production in association with two forward jets is sensitive to electroweak vector boson fusion and scattering processes. An observation of the electroweak production of the Z boson and an evidence of same sign WW production are reported.

  10. O(5) x U(1) electroweak theory

    International Nuclear Information System (INIS)

    Mukku, C.; Sayed, W.A.

    1981-01-01

    An anomaly-free O(5) x U(1) theory of electroweak interactions is described which provides a unified description of electroweak phenomena for two families of standard leptons and quarks. No ''new'' nonsequential-type fermions are introduced, unlike the case for all past studies based on this group. The present scheme requires the introduction of two further charged and three more neutral gauge fields over and above those of SU(2) x U(1) giving rise to new neutral and charged currents

  11. Comments on the electroweak phase transition

    International Nuclear Information System (INIS)

    Dine, M.; Leigh, R.G.; Huet, P.; Linde, A.; Linde, D.

    1992-01-01

    We report on an investigation of various problems related to the theory of the electroweak phase transition. This includes a determination of the nature of the phase transition, a discussion of the possible role of higher order radiative corrections and the theory of the formation and evolution of the bubbles of the new phase. We find in particular that no dangerous linear terms appear in the effective potential. However, the strength of the first-order phase transition is 2/3 times less than what follows from the one-loop approximation. This rules out baryogenesis in the minimal version of the electroweak theory with light Higgs bosons. (orig.)

  12. Top and Electroweak Measurements at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Bartos, P. [Comenius U.

    2016-01-01

    In this report, we summarize the latest results of the top-quark mass and electroweak measurements from the Tevatron. Since the world combination of top-quark mass measurements was done, CDF and D0 experiments improved the precision of several results. Some of them reach the relative precition below 1% for a single measurement. From the electroweak results, we report on the WW and WZ production cross section, measurements of the weak mixing angle and indirect measurements of W boson mass. The Tevatron results of the weak mixing angle are still the most precise ones of hadron colliders.

  13. Covariant meson-baryon scattering with chiral and large Nc constraints

    International Nuclear Information System (INIS)

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

    2001-05-01

    We give a review of recent progress on the application of the relativistic chiral SU(3) Lagrangian to meson-baryon scattering. It is shown that a combined chiral and 1/N c expansion of the Bethe-Salpeter interaction kernel leads to a good description of the kaon-nucleon, antikaon-nucleon and pion-nucleon scattering data typically up to laboratory momenta of p lab ≅ 500 MeV. We solve the covariant coupled channel Bethe-Salpeter equation with the interaction kernel truncated to chiral order Q 3 where we include only those terms which are leading in the large N c limit of QCD. (orig.)

  14. On chiral and non chiral 1D supermultiplets

    Energy Technology Data Exchange (ETDEWEB)

    Toppan, Francesco, E-mail: toppan@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (TEO/CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Fisica Teorica

    2011-07-01

    In this talk I discuss and clarify some issues concerning chiral and non chiral properties of the one-dimensional supermultiplets of the N-extended supersymmetry. Quaternionic chirality can be defined for N = 4, 5, 6, 7, 8. Octonionic chirality for N = 8 and beyond. Inequivalent chiralities only arise when considering several copies of N = 4 or N = 8 supermultiplets. (author)

  15. On chiral and non chiral 1D supermultiplets

    International Nuclear Information System (INIS)

    Toppan, Francesco

    2011-01-01

    In this talk I discuss and clarify some issues concerning chiral and non chiral properties of the one-dimensional supermultiplets of the N-extended supersymmetry. Quaternionic chirality can be defined for N = 4, 5, 6, 7, 8. Octonionic chirality for N = 8 and beyond. Inequivalent chiralities only arise when considering several copies of N = 4 or N = 8 supermultiplets. (author)

  16. Lagrangian of superfluid 3He

    International Nuclear Information System (INIS)

    Theodorakis, S.

    1988-01-01

    This paper presents a phenomenological Lagrangian that fully describes the dynamics of any homogeneous phase of superfluid 3 He, unitary or not, omitting relaxation. This Lagrangian is built by using the concept of a local SO(3) x SO(3) x U(1) symmetry. The spin and angular momentum play the role of gauge fields. We derive the Leggett equations for spin and orbital dynamics from the equations of motion, for both the A and the B phase. This Lagrangian not only enables us to describe both the spin and orbital dynamics of superfluid 3 He in a unified fashion, but can also be used for finding the dynamics in any experimental situation. Furthermore, it can describe the dynamics of the magnitude, as well as of the orientation of the order parameter, and thus it can be used to describe the dynamics of the A-B phase transition

  17. Chiral asymmetry in nuclear beta decay

    International Nuclear Information System (INIS)

    van Klinken, J.

    1987-01-01

    Nuclear β decay can be instrumental to electroweak unification studies by observation of the degree of longitudinal polarization of β rays from allowed Fermi and from allowed Gamow-Teller decays. Possible deviations from maximality of this polarization bear on a fundamental question: is there a manifest left-right symmetry, indicated by right-handed currents and V+A admixture to a dominant V-A interaction? Discussed are absolute β - and relative β + measurements. The β - measurements are of long-standing age; the β + measurements are recent and not yet fully analyzed. A striking consequence of the polarization may be an intimate relation with the origin of life: can it be that the chirality of biomolecules is determined by the longitudinal polarization of β rays? 20 references, 9 figures

  18. Chiral Models in Noncommutative N=1/2 Four Dimensional Superspace

    DEFF Research Database (Denmark)

    Ryttov, Thomas; Sannino, Francesco

    2005-01-01

    We derive the component Lagrangian for a generic N=1/2 supersymmetric chiral model with an arbitrary number of fields in four space-time dimensions. We then investigate a toy model in which the deformation parameter modifies the undeformed potential near the origin of the field space in a way which...

  19. Analysis of K → 3π decays in chiral perturbation theory

    International Nuclear Information System (INIS)

    Cheng Haiyang; Cheung, C.Y.; Yeung Waibong

    1989-01-01

    Using the recently proposed higher-order chiral Lagrangians determined from the integration of nontopological chiral anomalies, we calculate corrections to the current-algebra analysis of K→3π decay amplitudes expanded in powers of the Dalitz variables. Effects of quartic-derivative weak chiral Lagrangians are determined through the use of short-distance effective weak Hamiltonian and the factorization method. We find that (1) the constant and linear terms in the amplitude for ΔI=1/2 K→3π are in excellent agreement with experiment; the previous discrepancy of (20-35)% between current algebra and data is thus accounted for by the higher-order effective Lagrangians, (2) the penguin interaction does not play an essential role in the ΔI=1/2 rule, for otherwise it will lead to a large disagreement for the constant and linear terms, (3) one of the two quadratic terms in the ΔI=1/2 process, which arise from the quartic chiral Lagrangians, is in accord with data within experimental errors, while the other is off by four standard deviations, (4) the linear term in the ΔI=3/2 transitions is in good agreement with experiment and contributions from quadratic terms are sizable. (orig.)

  20. Electroweak properties of particle physics. Volume 2

    International Nuclear Information System (INIS)

    Aleksan, R.; Ellis, N.; Falvard, A.; Fayard, L.; Frere, J.M.; Kuehn, J.H.; Le Yaouanc, A.; Roudeau, P.; Wormser, G.

    1991-01-01

    The 23th GIf school was held at Ecole Polytechnique, Palaiseau, France from 16 to 20 September 1991. The subject was large: Electroweak properties of heavy quarks. The second part has been devoted to B physics at hadron machines, search for Top, Charm particle physics and Quarkonium physics

  1. Prospects on electroweak physics from the LHC

    International Nuclear Information System (INIS)

    Vikas, Pratibha

    2001-01-01

    The abundant production of gauge bosons, gauge boson pairs and top quarks at the LHC will offer the opportunity for comprehensive and challenging tests of theoretical predictions in the electroweak sector. Some issues which influence these measurements followed by prospects on some possible measurements by the ATLAS and CMS experiments at the Large Hadron Collider (LHC), at CERN are discussed. (author)

  2. Electroweak Physics in the Forward Region

    CERN Multimedia

    Sirendi, Marek

    2015-01-01

    LHCb has an active electroweak physics programme with measurements of inclusive processes such as Z and W production in leptonic final states already published. The EW working group is also branching into jet physics with completed Z+jet and Z+b-jet analyses. Recent results in this field are presented.

  3. Towards a natural theory of electroweak interactions

    Science.gov (United States)

    Dobrescu, Bogdan A.

    1998-01-01

    I study theories of electroweak symmetry breaking that may describe naturally the electromagnetic and weak interactions of the elementary particles observed so far (quarks, leptons and gauge bosons). These theories should explain why the energy scale at which the electroweak symmetry is spontaneously broken (246 GeV), called the 'electroweak scale', is seventeen orders of magnitude smaller than the 'Planck scale', which is associated with the quantum origin of gravity. I discuss first theories where the electroweak symmetry is broken by the dynamics of new strong interactions, naturally producing the hierarchy between the Planck scale and the electroweak scale. I show that in a realistic class of models of this type, the new gauge bosons needed for generating the mass of the heaviest quark have couplings which require a careful adjustment in order to be compatible with experimental data. In the case where the strong dynamics produces a composite spinless particle ('Higgs boson') whose interactions break the electroweak symmetry, I derive an upper bound of 460 GeV on the Higgs boson mass from experimental constraints on processes sensitive to new physics. I also discuss a different type of theory that explains the hierarchy of energy scales, based on a special symmetry, called supersymmetry, which requires the existence of new particles ('superpartners'). No superpartners have been seen in experiments. Therefore, if they exist, they must have masses larger than the particles known so far, implying that supersymmetry is not exact. In the simplest models, supersymmetry breaking is transmitted to the superpartners by standard gauge interactions. I show that all known models of this type are likely to be unacceptable because they do not admit a stable and phenomenologically viable ground state of the universe ('vacuum'). I then construct modified versions of these models that permit viable stable vacua. Also, I present a new model in which supersymmetry breaking is

  4. Gelation induced supramolecular chirality: chirality transfer, amplification and application.

    Science.gov (United States)

    Duan, Pengfei; Cao, Hai; Zhang, Li; Liu, Minghua

    2014-08-14

    Supramolecular chirality defines chirality at the supramolecular level, and is generated from the spatial arrangement of component molecules assembling through non-covalent interactions such as hydrogen bonding, van der Waals interactions, π-π stacking, hydrophobic interactions and so on. During the formation of low molecular weight gels (LMWGs), one kind of fascinating soft material, one frequently encounters the phenomenon of chirality as well as chiral nanostructures, either from chiral gelators or even achiral gelators. A view of gelation-induced supramolecular chirality will be very helpful to understand the self-assembly process of the gelator molecules as well as the chiral structures, the regulation of the chirality in the gels and the development of the "smart" chiral materials such as chiroptical devices, catalysts and chiral sensors. It necessitates fundamental understanding of chirality transfer and amplification in these supramolecular systems. In this review, recent progress in gelation-induced supramolecular chirality is discussed.

  5. Mechanical separation of chiral dipoles by chiral light

    International Nuclear Information System (INIS)

    Canaguier-Durand, Antoine; Hutchison, James A; Genet, Cyriaque; Ebbesen, Thomas W

    2013-01-01

    We calculate optical forces and torques exerted on a chiral dipole by chiral light fields and reveal genuine chiral forces in combining the chiral contents of both light field and dipolar matter. Here, the optical chirality is characterized in a general way through the definition of optical chirality density and chirality flow. We show, in particular, that both terms have mechanical effects associated, respectively, with reactive and dissipative components of the chiral forces. Remarkably, these chiral force components are directly related to standard observables: optical rotation for the reactive component and circular dichroism for the dissipative one. As a consequence, the resulting forces and torques are dependent on the enantiomeric form of the chiral dipole. This suggests promising strategies for using chiral light forces to mechanically separate chiral objects according to their enantiomeric form. (paper)

  6. Remarks on gauge variables and singular Lagrangians

    International Nuclear Information System (INIS)

    Chela-Flores, J.; Janica-de-la-Torre, R.; Kalnay, A.J.; Rodriguez-Gomez, J.; Rodriguez-Nunez, J.; Tascon, R.

    1977-01-01

    The relevance is discussed of gauge theory, based on a singular Lagrangian density, to the foundations of field theory. The idea that gauge transformations could change the physics of systems where the Lagrangian is singular is examined. (author)

  7. Active chiral fluids.

    Science.gov (United States)

    Fürthauer, S; Strempel, M; Grill, S W; Jülicher, F

    2012-09-01

    Active processes in biological systems often exhibit chiral asymmetries. Examples are the chirality of cytoskeletal filaments which interact with motor proteins, the chirality of the beat of cilia and flagella as well as the helical trajectories of many biological microswimmers. Here, we derive constitutive material equations for active fluids which account for the effects of active chiral processes. We identify active contributions to the antisymmetric part of the stress as well as active angular momentum fluxes. We discuss four types of elementary chiral motors and their effects on a surrounding fluid. We show that large-scale chiral flows can result from the collective behavior of such motors even in cases where isolated motors do not create a hydrodynamic far field.

  8. Lagrangian multi-particle statistics

    DEFF Research Database (Denmark)

    Lüthi, Beat; Berg, Jacob; Ott, Søren

    2007-01-01

    Combined measurements of the Lagrangian evolution of particle constellations and the coarse-grained velocity derivative tensor. partial derivative(u) over tilde (i) /partial derivative x(j) are presented. The data are obtained from three-dimensional particle tracking measurements in a quasi isotr...

  9. Higgs mass bounds from a chirally invariant lattice Higgs-Yukawa model with overlap fermions

    International Nuclear Information System (INIS)

    Gerhold, Philipp; Kallarackal, Jim

    2008-10-01

    We study the parameter dependence of the Higgs mass in a chirally invariant lattice Higgs-Yukawa model emulating the same Higgs-fermion coupling structure as in the Higgs sector of the electroweak Standard Model. Eventually, the aim is to establish upper and lower Higgs mass bounds. Here we present our preliminary results on the lower Higgs mass bound at several selected values for the cutoff and give a brief outlook towards the upper Higgs mass bound. (orig.)

  10. Relaxation of the chiral imbalance in dense matter of a neutron star

    Directory of Open Access Journals (Sweden)

    Dvornikov Maxim

    2016-01-01

    Full Text Available Using the quantum field theory methods, we calculate the helicity flip of an electron scattering off protons in dense matter of a neutron star. The influence of the electroweak interaction between electrons and background nucleons on the helicity flip is examined. We also derive the kinetic equation for the chiral imbalance. The derived kinetic equation is compared with the results obtained by other authors.

  11. Electroweak radiative corrections to Higgs production via vector boson fusion using soft-collinear effective theory

    International Nuclear Information System (INIS)

    Fuhrer, Andreas; Manohar, Aneesh V.; Waalewijn, Wouter J.

    2011-01-01

    Soft-collinear effective theory (SCET) is applied to compute electroweak radiative corrections to Higgs production via gauge boson fusion, qq→qqH. There are several novel features which make this process an interesting application of SCET: The amplitude is proportional to the Higgs vacuum expectation value, and so is not a gauge singlet amplitude. Standard resummation methods require a gauge singlet operator and do not apply here. The SCET analysis requires operators with both collinear and soft external fields, with the Higgs vacuum expectation value being described by an external soft φ field. There is a scalar soft-collinear transition operator in the SCET Lagrangian which contributes to the scattering amplitude, and is derived here.

  12. Electroweak baryogenesis with primordial hypermagnetic fields

    International Nuclear Information System (INIS)

    Ayala, Alejandro; Pallares, Gabriel; Besprosvany, Jaime; Piccinelli, Gabriella

    2002-01-01

    Primordial magnetic fields, independently of their origin, could have had a significant influence over several physical processes that took place during the evolution of the early universe, in particular baryogenesis. Recall that for temperatures above the electroweak phase transition (T > 100 GeV), the symmetry of the standard model corresponded to the U(1)y hypercharge group, instead of the U(1)em electromagnetic group and are therefore properly called hypermagnetic fields. In this work, we show that during a first order electroweak phase transition, the presence of hypermagnetic fields produces an axial charge segregation in the reflection and transmission of fermions off the true vacuum bubbles. We also comment on the possible consequences that these processes have for the generation of baryon number during the phase transition

  13. A (critical) overview of electroweak symmetry breaking

    International Nuclear Information System (INIS)

    Csaki, Csaba

    2010-01-01

    This presentation discusses the following points: The standard Higgs, big vs. little hierarchy; Electroweak Symmetry Breaking in supersymmetry and little hierarchy of Minimal Supersymmetric Standard Model (MSSM): Buried Higgs, Bigger quartic (D-terms, Next-to-Minimal Supersymmetric Standard Model (NMSSM), fat Higgs,..); Strong dynamics and related models: Technicolor, Monopole condensate, Warped extra dimensions, Realistic RS, Higgs-less, Composite Higgs, Little Higgs. In summary, we do not understand how Higgs is light and still no trace of new physics. In Supersymmetry (SUSY) it calls for extension of MSSM. In strong dynamics models: electroweak penguin (EWP) usually issue (Warped extra dimension - composite Higgs, Higgs-less, Little Higgs, Technicolor, monopole condensation,..). None of them is fully convincing but LHC should settle these

  14. Introduction to gauge theories of electroweak interactions

    International Nuclear Information System (INIS)

    Ecker, G.

    1982-01-01

    Intended as a lecture for physicists who are not familiar with the sophisticated theoretical models in particle physics. Starting with the standard gauge model of electromagnetic, weak and strong interactions the recent developments of a unified gauge theory of electroweak interactions are shown. Shortcomings in the unitarity problem of the V-A fermi theory of charged intermediate vector bosons. Presented are the spontaneous symmetry breaking in quantum mechanics, the abelian higgs model as an example of a spontaneously broken gauge field theory, the minimal gauge group of electroweak interactions, the fermion mass generation. Further on the anomalies in quantum field theory are discussed and the radiative corrections to the vector boson masses are considered. (H.B.)

  15. A determination of electroweak parameters at HERA

    Science.gov (United States)

    H1 Collaboration; Aktas, A.; Andreev, V.; Anthonis, T.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Babaev, A.; Backovic, S.; Bähr, J.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Baumgartner, S.; Becker, J.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, Ch.; Berger, N.; Bizot, J. C.; Boenig, M.-O.; Boudry, V.; Bracinik, J.; Brandt, G.; Brisson, V.; Brown, D. P.; Bruncko, D.; Büsser, F. W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A. J.; Caron, S.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Contreras, J. G.; Coughlan, J. A.; Cox, B. E.; Cozzika, G.; Cvach, J.; Dainton, J. B.; Dau, W. D.; Daum, K.; de Boer, Y.; Delcourt, B.; de Roeck, A.; Desch, K.; de Wolf, E. A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Ellerbrock, M.; Erdmann, W.; Essenov, S.; Falkewicz, A.; Faulkner, P. J. W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Finke, L.; Fleischer, M.; Fleischmann, P.; Fleming, Y. H.; Flucke, G.; Fomenko, A.; Foresti, I.; Franke, G.; Frisson, T.; Gabathuler, E.; Garutti, E.; Gayler, J.; Gerlich, C.; Ghazaryan, S.; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Goyon, C.; Grab, C.; Greenshaw, T.; Gregori, M.; Grell, B. R.; Grindhammer, G.; Gwilliam, C.; Haidt, D.; Hajduk, L.; Hansson, M.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Henshaw, O.; Herrera, G.; Hildebrandt, M.; Hiller, K. H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Hussain, S.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jönsson, L.; Johnson, D. P.; Jung, A. W.; Jung, H.; Kapichine, M.; Katzy, J.; Keller, N.; Kenyon, I. R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Korbel, V.; Kostka, P.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Krüger, K.; Kückens, J.; Landon, M. P. J.; Lange, W.; Laštovička, T.; Laštovička-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lueders, H.; Lüke, D.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Mangano, S.; Marage, P.; Marshall, R.; Martisikova, M.; Martyn, H.-U.; Maxfield, S. J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A. B.; Meyer, H.; Meyer, J.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mladenov, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J. V.; Mozer, M. U.; Müller, K.; Murín, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, P. R.; Niebuhr, C.; Nikiforov, A.; Nikitin, D.; Nowak, G.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J. E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Papadopoulou, T.; Pascaud, C.; Patel, G. D.; Peez, M.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Plačakytė, R.; Portheault, B.; Povh, B.; Prideaux, P.; Raicevic, N.; Reimer, P.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D. P. C.; Sauvan, E.; Schätzel, S.; Schilling, F.-P.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.-C.; Sedlák, K.; Sefkow, F.; Shaw-West, R. N.; Sheviakov, I.; Shtarkov, L. N.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, A.; Stella, B.; Stiewe, J.; Strauch, I.; Straumann, U.; Tchoulakov, V.; Thompson, G.; Thompson, P. D.; Tomasz, F.; Traynor, D.; Truöl, P.; Tsakov, I.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, M.; Usik, A.; Utkin, D.; Valkár, S.; Valkárová, A.; Vallée, C.; van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vest, A.; Vinokurova, S.; Volchinski, V.; Vujicic, B.; Wacker, K.; Wagner, J.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Werner, N.; Wessels, M.; Wessling, B.; Wigmore, C.; Wissing, Ch.; Wolf, R.; Wünsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Žáček, J.; Zálešák, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y. C.; Zimmermann, J.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

    2006-01-01

    Using the deep inelastic ep and ep charged and neutral current scattering cross sections previously published, a combined electroweak and QCD analysis is performed to determine electroweak parameters accounting for their correlation with parton distributions. The data used have been collected by the H1 experiment in 1994 2000 and correspond to an integrated luminosity of 117.2 pb. A measurement is obtained of the W propagator mass in charged current ep scattering. The weak mixing angle sinθ is determined in the on-mass-shell renormalisation scheme. A first measurement at HERA is made of the light quark weak couplings to the Z boson and a possible contribution of right-handed isospin components to the weak couplings is investigated.

  16. A Determination of Electroweak Parameters at HERA

    CERN Document Server

    Aktas, A.; Anthonis, T.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Babaev, A.; Backovic, S.; Bahr, J.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Baumgartner, S.; Becker, J.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, Ch.; Berger, N.; Bizot, J.C.; Boenig, M.-O.; Boudry, V.; Bracinik, J.; Brandt, G.; Brisson, V.; Brown, D.P.; Bruncko, D.; Busser, F.W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Caron, S.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Contreras, J.G.; Coughlan, J.A.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; de Boer, Y.; Delcourt, B.; De Roeck, A.; Desch, K.; De Wolf, E.A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, Guenter; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Ellerbrock, M.; Erdmann, W.; Essenov, S.; Falkewicz, A.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Finke, L.; Fleischer, M.; Fleischmann, P.; Fleming, Y.H.; Flucke, G.; Fomenko, A.; Foresti, I.; Franke, G.; Frisson, T.; Gabathuler, E.; Garutti, E.; Gayler, J.; Gerlich, C.; Ghazaryan, Samvel; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Goyon, C.; Grab, C.; Greenshaw, T.; Gregori, M.; Grell, B.R.; Grindhammer, Guenter; Gwilliam, C.; Haidt, D.; Hajduk, L.; Hansson, M.; Heinzelmann, G.; Henderson, R.C.W.; Henschel, H.; Henshaw, O.; Herrera, G.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Hussain, S.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jung, Andreas Werner; Jung, H.; Kapichine, M.; Katzy, J.; Keller, N.; Kenyon, I.R.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Korbel, V.; Kostka, P.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Kuckens, J.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Lastovicka-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lueders, H.; Luke, D.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Mangano, S.; Marage, P.; Marshall, R.; Martisikova, M.; Martyn, H.-U.; Maxeld, S.J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mladenov, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, Matthias Ulrich; Muller, K.; Murin, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, Paul R.; Niebuhr, C.; Nikiforov, A.; Nikitin, D.; Nowak, G.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J.E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Papadopoulou, T.; Pascaud, C.; Patel, G.D.; Peez, M.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Placakyte, R.; Portheault, B.; Povh, B.; Prideaux, P.; Raicevic, N.; Reimer, P.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D.P.C.; Sauvan, E.; Schatzel, S.; Schilling, F.-P.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schoning, A.; Schultz-Coulon, H.-C.; Sedlak, K.; Sefkow, F.; Shaw-West, R.N.; Sheviakov, I.; Shtarkov, L.N.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Stella, B.; Stiewe, J.; Strauch, I.; Straumann, U.; Tchoulakov, V.; Thompson, Graham; Thompson, P.D.; Tomasz, F.; Traynor, D.; Truoel, Peter; Tsakov, I.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, Marcel; Usik, A.; Utkin, D.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vest, A.; Vinokurova, S.; Volchinski, V.; Vujicic, B.; Wacker, K.; Wagner, J.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Werner, N.; Wessels, M.; Wessling, B.; Wigmore, C.; Wissing, Ch.; Wolf, R.; Wunsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y.C.; Zimmermann, J.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

    2006-01-01

    Using the deep inelastic e^+p and e^-p charged and neutral current scattering cross sections previously published, a combined electroweak and QCD analysis is performed to determine electroweak parameters accounting for their correlation with parton distributions. The data used have been collected by the H1 experiment in 1994-2000 and correspond to an integrated luminosity of 117.2 pb^{-1}. A measurement is obtained of the W propagator mass in charged current ep scattering. The weak mixing angle sin^2 theta_W is determined in the on-mass-shell renormalisation scheme. A first measurement at HERA is made of the light quark weak couplings to the Z^0 boson and a possible contribution of right-handed isospin components to the weak couplings is investigated.

  17. Competitive chiral induction in a 2D molecular assembly: Intrinsic chirality versus coadsorber-induced chirality.

    Science.gov (United States)

    Chen, Ting; Li, Shu-Ying; Wang, Dong; Wan, Li-Jun

    2017-11-01

    Noncovalently introducing stereogenic information is a promising approach to embed chirality in achiral molecular systems. However, the interplay of the noncovalently introduced chirality with the intrinsic chirality of molecules or molecular aggregations has rarely been addressed. We report a competitive chiral expression of the noncovalent interaction-mediated chirality induction and the intrinsic stereogenic center-controlled chirality induction in a two-dimensional (2D) molecular assembly at the liquid/solid interface. Two enantiomorphous honeycomb networks are formed by the coassembly of an achiral 5-(benzyloxy)isophthalic acid (BIC) derivative and 1-octanol at the liquid/solid interface. The preferential formation of the globally homochiral assembly can be achieved either by using the chiral analog of 1-octanol, ( S )-6-methyl-1-octanol, as a chiral coadsorber to induce chirality to the BIC assembly via noncovalent hydrogen bonding or by covalently linking a chiral center in the side chain of BIC. Both the chiral coadsorber and the intrinsically chiral BIC derivative can act as a chiral seeds to induce a preferred handedness in the assembly of the achiral BIC derivatives. Furthermore, the noncovalent interaction-mediated chirality induction can restrain or even overrule the manifestation of the intrinsic chirality of the BIC molecule and dominate the handedness of the 2D molecular coassembly. This study provides insight into the interplay of intrinsically chiral centers and external chiral coadsorbers in the chiral induction, transfer, and amplification processes of 2D molecular assembly.

  18. Structure functions of electroweak boson and leptons

    International Nuclear Information System (INIS)

    Slominski, W.; Szwed, J.

    1996-01-01

    The QCD structure of the electroweak bosons is reviewed and the lepton structure function is defined and calculated. The leading order splitting functions of electron into quarks are extracted, showing an important contribution from γ-Z interference. Leading logarithmic QCD evolution equations are constructed and solved in the asymptotic region where log 2 behavior of the Parton densities is observed. Possible applications with clear manifestation of ''resolved'' photon and weak bosons are discussed. 8 refs., 3 figs

  19. PRECISION ELECTROWEAK MEASUREMENTS AND THE HIGGS MASS

    International Nuclear Information System (INIS)

    MARCIANO, W.J.

    2004-01-01

    The utility of precision electroweak measurements for predicting the Standard Model Higgs mass via quantum loop effects is discussed. Current constraints from m w and sin 2 θ w (m z ) ovr MS imply a relatively light Higgs ∼< 154 GeV which is consistent with Supersymmetry expectations. The existence of Supersymmetry is further suggested by a discrepancy between experiment and theory for the muon anomalous magnetic moment. Constraints from precision studies on other types of ''New Physics'' are also briefly described

  20. Electroweak Precision Measurements with the ATLAS Detector

    CERN Document Server

    Linck, Rebecca Anne; The ATLAS collaboration

    2018-01-01

    As part of its ongoing exploration into the nature of the particles produced in high energy proton-proton collisions, the ATLAS detector has been used to perform a number of new precision electroweak measurements. In this talk the recent measurements of the W-boson mass, the Drell-Yan triple-differential cross-section and the polarisation of tau leptons in Z/γ* → ττ decays will be discussed.

  1. Electroweak theory and the Standard Model

    CERN Multimedia

    CERN. Geneva; Giudice, Gian Francesco

    2004-01-01

    There is a natural splitting in four sectors of the theory of the ElectroWeak (EW) Interactions, at pretty different levels of development/test. Accordingly, the 5 lectures are organized as follows, with an eye to the future: Lecture 1: The basic structure of the theory; Lecture 2: The gauge sector; Lecture 3: The flavor sector; Lecture 4: The neutrino sector; Lecture 5: The EW symmetry breaking sector.

  2. Optimal tests for electroweak loop effects

    International Nuclear Information System (INIS)

    Aoki, Kenichi; Aoyama, Hideaki; Harvard Univ., Cambridge, MA

    1986-01-01

    A statistical analysis is given for the experimental precision necessary for establishing loop effects in the electroweak theory. Cases with three observables, gauge boson masses and the Weinberg angle, is analyzed by an optimised test. An information on the Weinberg angle with even 5% error (+-.01 in sin 2 thetasub(W)) is shown to reduce the requirement for the measurements of gauge boson masses significantly. (orig.)

  3. Electroweak measurements with the ATLAS detector

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    The seminar presents an overview of the ATLAS electroweak physics programme. Recent measurements of di-boson and multi-boson production processes involving combinations of W, Z and isolated photons, associated with up to two jets, at 8 TeV proton-proton collisions are discussed. Inclusive, fiducial and differential production cross sections are presented, including vector-boson fusion and vector-boson scattering processes. These measurements allow to derive constraints on anomalous triple and quartic gauge couplings.

  4. On stability of electroweak vacuum during inflation

    Energy Technology Data Exchange (ETDEWEB)

    Shkerin, A., E-mail: andrey.shkerin@epfl.ch [Institut de Théorie des Phénomènes Physiques, EPFL, CH-1015 Lausanne (Switzerland); Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, 117312 Moscow (Russian Federation); Sibiryakov, S. [Institut de Théorie des Phénomènes Physiques, EPFL, CH-1015 Lausanne (Switzerland); Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, 117312 Moscow (Russian Federation); CERN Theory Division, CH-1211 Geneva 23 (Switzerland)

    2015-06-30

    We study Coleman–De Luccia tunneling of the Standard Model Higgs field during inflation in the case when the electroweak vacuum is metastable. We verify that the tunneling rate is exponentially suppressed. The main contribution to the suppression is the same as in flat space–time. We analytically estimate the corrections due to the expansion of the universe and an effective mass term in the Higgs potential that can be present at inflation.

  5. On stability of electroweak vacuum during inflation

    International Nuclear Information System (INIS)

    Shkerin, A.; Sibiryakov, S.

    2015-01-01

    We study Coleman–De Luccia tunneling of the Standard Model Higgs field during inflation in the case when the electroweak vacuum is metastable. We verify that the tunneling rate is exponentially suppressed. The main contribution to the suppression is the same as in flat space–time. We analytically estimate the corrections due to the expansion of the universe and an effective mass term in the Higgs potential that can be present at inflation

  6. On stability of electroweak vacuum during inflation

    CERN Document Server

    Shkerin, Andrey

    2015-01-01

    We study Coleman-De Luccia tunneling of the Standard Model Higgs field during inflation in the case when the electroweak vacuum is metastable. We verify that the tunneling rate is exponentially suppressed. The main contribution to the suppression is the same as in flat space-time. We analytically estimate the corrections due to the expansion of the universe and an effective mass term in the Higgs potential that can be present at inflation.

  7. Electroweak Calibration of the Higgs Characterization Model

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    I will present the preliminary results of histogram fits using the Higgs Combine histogram fitting package. These fits can be used to estimate the effects of electroweak contributions to the p p -> H mu+ mu- Higgs production channel and calibrate Beyond Standard Model (BSM) simulations which ignore these effects. I will emphasize my findings' significance in the context of other research here at CERN and in the broader world of high energy physics.

  8. Flavor universal dynamical electroweak symmetry breaking

    International Nuclear Information System (INIS)

    Burdman, G.; Evans, N.

    1999-01-01

    The top condensate seesaw mechanism of Dobrescu and Hill allows electroweak symmetry to be broken while deferring the problem of flavor to an electroweak singlet, massive sector. We provide an extended version of the singlet sector that naturally accommodates realistic masses for all the standard model fermions, which play an equal role in breaking electroweak symmetry. The models result in a relatively light composite Higgs sector with masses typically in the range of (400 - 700) GeV. In more complete models the dynamics will presumably be driven by a broken gauged family or flavor symmetry group. As an example of the higher scale dynamics a fully dynamical model of the quark sector with a GIM mechanism is presented, based on an earlier top condensation model of King using broken family gauge symmetry interactions (that model was itself based on a technicolor model of Georgi). The crucial extra ingredient is a reinterpretation of the condensates that form when several gauge groups become strong close to the same scale. A related technicolor model of Randall which naturally includes the leptons too may also be adapted to this scenario. We discuss the low energy constraints on the massive gauge bosons and scalars of these models as well as their phenomenology at the TeV scale. copyright 1999 The American Physical Society

  9. Hyperscaling violation and electroweak symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Elander, Daniel, E-mail: pelander@purdue.edu [Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907-2036 (United States); Lawrance, Robert; Piai, Maurizio [Department of Physics, College of Science, Swansea University, Singleton Park, Swansea, Wales (United Kingdom)

    2015-08-15

    We consider a class of simplified models of dynamical electroweak symmetry breaking built in terms of their five-dimensional weakly-coupled gravity duals, in the spirit of bottom-up holography. The sigma-model consists of two abelian gauge bosons and one real, non-charged scalar field coupled to gravity in five dimensions. The scalar potential is a simple exponential function of the scalar field. The background metric resulting from solving the classical equations of motion exhibits hyperscaling violation, at least at asymptotically large values of the radial direction. We study the spectrum of scalar composite states of the putative dual field theory by fluctuating the sigma-model scalars and gravity, and discuss in which cases we find a parametrically light scalar state in the spectrum. We model the spontaneous breaking of the (weakly coupled) gauge symmetry to the diagonal subgroup by the choice of IR boundary conditions. We compute the mass spectrum of spin-1 states, and the precision electroweak parameter S as a function of the hyperscaling coefficient. We find a general bound on the mass of the lightest spin-1 resonance, by requiring that the indirect bounds on the precision parameters be satisfied, that implies that precision electroweak physics excludes the possibility of a techni-rho meson with mass lighter than several TeV.

  10. Electroweak boson production in Pb+Pb

    CERN Document Server

    Balestri, T; The ATLAS collaboration

    2013-01-01

    Lead-lead collisions at the LHC are capable of producing a system of deconfined quarks and gluons at unprecedented energy density and temperature. Partonic-level interactions and energy-loss mechanisms in the medium can be studied with the aid of electroweak bosons which carry important information about the properties of the medium. Electroweak bosons form a class of unique high-$p_{T}$ probes because their decay products do not interact with the strongly-coupled medium, providing a benchmark for a variety of other phenomena measured with strongly interacting particles. The ATLAS experiment measures isolated high-$p_{T}$ photons, W and Z bosons via different decay channels. New analyses of experimental data obtained at the LHC with lead-lead beams at $\\sqrt{s_{NN}}$ = 2.76 TeV. This talk will present a comprehensive study of the scaling properties of electroweak bosons showing linear proportionality of production rates to the nuclear thickness function; rapidity distributions W-decays directly sensitivity to...

  11. Fundamental Physics with Electroweak Probes of Nuclei

    Science.gov (United States)

    Pastore, Saori

    2018-02-01

    The past decade has witnessed tremendous progress in the theoretical and computational tools that produce our understanding of nuclei. A number of microscopic calculations of nuclear electroweak structure and reactions have successfully explained the available experimental data, yielding a complex picture of the way nuclei interact with electroweak probes. This achievement is of great interest from the pure nuclear-physics point of view. But it is of much broader interest too, because the level of accuracy and confidence reached by these calculations opens up the concrete possibility of using nuclei to address open questions in other sub-fields of physics, such as, understanding the fundamental properties of neutrinos, or the particle nature of dark matter. In this talk, I will review recent progress in microscopic calculations of electroweak properties of light nuclei, including electromagnetic moments, form factors and transitions in between lowlying nuclear states along with preliminary studies for single- and double-beta decay rates. I will illustrate the key dynamical features required to explain the available experimental data, and, if time permits, present a novel framework to calculate neutrino-nucleus cross sections for A > 12 nuclei.

  12. Some aspects of chirality: Fermion masses and chiral p-forms

    Energy Technology Data Exchange (ETDEWEB)

    Kleppe, A

    1997-05-01

    The properties of fermion mass matrices are investigated from different points of view, both within the minimal Standard Model and in extensions of the model. It is shown how mass matrix invariants are used to define the measurables of the quark mixing matrix as invariant functions of the mass matrices. One model is presented where the family pattern is suggested to originate from a kind of mass scaling. A Lagrangian density is defined for an entire charge sector, such that the existence of a Dirac field with mass m{sub 0} implies the existence of other Dirac fields where the corresponding quanta have masses Rm{sub 0}, R{sup 2}m{sub 0}, .. which are obtained by a discrete scale transformation. This suggests a certain type of democratic fermion mass matrices. Also extensions of the minimal Standard Model are investigated, obtained by including right-handed neutrinos in the model. The Standard Model extended by two right-handed neutrinos gives rise to a mass spectrum with two massive and three massless neutrinos. The phenomenological consequences of this model are discussed. The neutrino mass matrix in such a scheme has what is defined as a democratic texture. They are studied for the cases with two and three right-handed neutrinos, resp. The chiral fields that we find in the Standard Model have certain similarities with self-dual fields. Among other things, both chiral and self-dual fields suffer species doubling on the lattice. Chiral p-forms are self-dual fields that appear in twice odd dimensions. Chiral p-forms violate manifest covariance, in the same sense as manifest covariance is violated by non-covariant gauges in electrodynamics. It is shown that a covariant action can nevertheless be formulated for chiral p-forms, by introducing an infinite set of gauge fields in a carefully controlled way.

  13. Some aspects of chirality: Fermion masses and chiral p-forms

    International Nuclear Information System (INIS)

    Kleppe, A.

    1997-05-01

    The properties of fermion mass matrices are investigated from different points of view, both within the minimal Standard Model and in extensions of the model. It is shown how mass matrix invariants are used to define the measurables of the quark mixing matrix as invariant functions of the mass matrices. One model is presented where the family pattern is suggested to originate from a kind of mass scaling. A Lagrangian density is defined for an entire charge sector, such that the existence of a Dirac field with mass m 0 implies the existence of other Dirac fields where the corresponding quanta have masses Rm 0 , R 2 m 0 , .. which are obtained by a discrete scale transformation. This suggests a certain type of democratic fermion mass matrices. Also extensions of the minimal Standard Model are investigated, obtained by including right-handed neutrinos in the model. The Standard Model extended by two right-handed neutrinos gives rise to a mass spectrum with two massive and three massless neutrinos. The phenomenological consequences of this model are discussed. The neutrino mass matrix in such a scheme has what is defined as a democratic texture. They are studied for the cases with two and three right-handed neutrinos, resp. The chiral fields that we find in the Standard Model have certain similarities with self-dual fields. Among other things, both chiral and self-dual fields suffer species doubling on the lattice. Chiral p-forms are self-dual fields that appear in twice odd dimensions. Chiral p-forms violate manifest covariance, in the same sense as manifest covariance is violated by non-covariant gauges in electrodynamics. It is shown that a covariant action can nevertheless be formulated for chiral p-forms, by introducing an infinite set of gauge fields in a carefully controlled way

  14. Observation of chiral phonons

    KAUST Repository

    Zhu, Hanyu; Yi, Jun; Li, Ming-yang; Xiao, Jun; Zhang, Lifa; Yang, Chih-Wen; Kaindl, Robert A.; Li, Lain-Jong; Wang, Yuan; Zhang, Xiang

    2018-01-01

    Chirality reveals symmetry breaking of the fundamental interaction of elementary particles. In condensed matter, for example, the chirality of electrons governs many unconventional transport phenomena such as the quantum Hall effect. Here we show that phonons can exhibit intrinsic chirality in monolayer tungsten diselenide. The broken inversion symmetry of the lattice lifts the degeneracy of clockwise and counterclockwise phonon modes at the corners of the Brillouin zone. We identified the phonons by the intervalley transfer of holes through hole-phonon interactions during the indirect infrared absorption, and we confirmed their chirality by the infrared circular dichroism arising from pseudoangular momentum conservation. The chiral phonons are important for electron-phonon coupling in solids, phonon-driven topological states, and energy-efficient information processing.

  15. Observation of chiral phonons

    KAUST Repository

    Zhu, Hanyu

    2018-02-01

    Chirality reveals symmetry breaking of the fundamental interaction of elementary particles. In condensed matter, for example, the chirality of electrons governs many unconventional transport phenomena such as the quantum Hall effect. Here we show that phonons can exhibit intrinsic chirality in monolayer tungsten diselenide. The broken inversion symmetry of the lattice lifts the degeneracy of clockwise and counterclockwise phonon modes at the corners of the Brillouin zone. We identified the phonons by the intervalley transfer of holes through hole-phonon interactions during the indirect infrared absorption, and we confirmed their chirality by the infrared circular dichroism arising from pseudoangular momentum conservation. The chiral phonons are important for electron-phonon coupling in solids, phonon-driven topological states, and energy-efficient information processing.

  16. Lagrangian Studies of Lateral Mixing

    Science.gov (United States)

    2017-09-19

    Final Technical 3. DATES COVERED (From - To) 01/01/2009 – 12/31/2015 4. TITLE AND SUBTITLE Lagrangian Studies of Lateral Mixing 5a. CONTRACT NUMBER...public release; distribution is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT The Lateral Mixing Experiment (LATMIX) focused on mixing and...anomalies. LATMIX2 targeted the wintertime Gulf Stream, where deep mixed layers, strong lateral density gradients (Gulf Stream north wall) and the

  17. Emergent Electroweak Symmetry Breaking with Composite W, Z Bosons

    CERN Document Server

    Cui, Yanou; Wells, James D

    2009-01-01

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

  18. Progress toward the effective Quantum Chromodynamic Lagrangian from symmetry considerations

    International Nuclear Information System (INIS)

    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

  19. Lagrangian descriptors in dissipative systems.

    Science.gov (United States)

    Junginger, Andrej; Hernandez, Rigoberto

    2016-11-09

    The reaction dynamics of time-dependent systems can be resolved through a recrossing-free dividing surface associated with the transition state trajectory-that is, the unique trajectory which is bound to the barrier region for all time in response to a given time-dependent potential. A general procedure based on the minimization of Lagrangian descriptors has recently been developed by Craven and Hernandez [Phys. Rev. Lett., 2015, 115, 148301] to construct this particular trajectory without requiring perturbative expansions relative to the naive transition state point at the top of the barrier. The extension of the method to account for dissipation in the equations of motion requires additional considerations established in this paper because the calculation of the Lagrangian descriptor involves the integration of trajectories in forward and backward time. The two contributions are in general very different because the friction term can act as a source (in backward time) or sink (in forward time) of energy, leading to the possibility that information about the phase space structure may be lost due to the dominance of only one of the terms. To compensate for this effect, we introduce a weighting scheme within the Lagrangian descriptor and demonstrate that for thermal Langevin dynamics it preserves the essential phase space structures, while they are lost in the nonweighted case.

  20. Theoretical aspects of electroweak and other interactions in medium energy nuclear physics. Interim progress report

    International Nuclear Information System (INIS)

    Mukhopadhyay, N.C.

    1994-01-01

    Significant progress has been made in the current project year in the development of chiral soliton model and its applications to the electroweak structure of the nucleon and the Delta (1232) resonance. Further progress also has been made in the application of the perturbative QCD (pQCD) and the study of physics beyond the standard model. The postdoctoral associate and the graduate student working towards his Ph.D. degree have both made good progress. The review panel of the DOE has rated this program as a ''strong, high priority'' one. A total of fifteen research communications -- eight journal papers and, conference reports and seven other communications -- have been made during the project year so far. The principal investigator is a member of the Physics Advisory Committee of two nuclear accelerator facilities

  1. A demonstration that electroweak theory can violate parity automatically (leptonic case)

    Science.gov (United States)

    Furey, C.

    2018-02-01

    We bring to light an electroweak model which has been reappearing in the literature under various guises.1-5 In this model, weak isospin is shown to act automatically on states of only a single chirality (left). This is achieved by building the model exclusively from the raising and lowering operators of the Clifford algebra ℂl(4). That is, states constructed from these ladder operators mimic the behaviour of left- and right-handed electrons and neutrinos under unitary ladder operator symmetry. This ladder operator symmetry is found to be generated uniquely by su(2)L and u(1)Y. Crucially, the model demonstrates how parity can be maximally violated, without the usual step of introducing extra gauge and extra Higgs bosons, or ad hoc projectors.

  2. Chiral Spirals from Discontinuous Chiral Symmetry

    Science.gov (United States)

    Kojo, Toru

    2014-09-01

    Recently phases of the inhomongeneous chiral condensates (IChC) attract renewed attentions in quark matter context. A number of theoretical studies have suggested that in some domain of moderate quark density the IChC phases are energetically more favored than the normal, chiral symmetric phase. In particular, the NJL-type model studies indicate that the phase of IChCs may mask the usual 1st order chiral phase transition line and its critical end point, and might change the conventional wisdom. In this talk, I will discuss characteristic features of the IChC phases and their potential impacts on the compact star physics. In particular, some of the IChC phases open gaps near the quark Fermi surface, suppressing back-reaction from the quark to gluon sectors. This mechanism delays the chiral restoration in the strange quark sector, forbids the emergence of the large bag constant, and as a consequence, makes the quark matter EOS very stiff. Recently phases of the inhomongeneous chiral condensates (IChC) attract renewed attentions in quark matter context. A number of theoretical studies have suggested that in some domain of moderate quark density the IChC phases are energetically more favored than the normal, chiral symmetric phase. In particular, the NJL-type model studies indicate that the phase of IChCs may mask the usual 1st order chiral phase transition line and its critical end point, and might change the conventional wisdom. In this talk, I will discuss characteristic features of the IChC phases and their potential impacts on the compact star physics. In particular, some of the IChC phases open gaps near the quark Fermi surface, suppressing back-reaction from the quark to gluon sectors. This mechanism delays the chiral restoration in the strange quark sector, forbids the emergence of the large bag constant, and as a consequence, makes the quark matter EOS very stiff. NSF Grants PHY09-69790, PHY13-05891.

  3. Geometrical approach to central molecular chirality: a chirality selection rule

    OpenAIRE

    Capozziello, S.; Lattanzi, A.

    2004-01-01

    Chirality is of primary importance in many areas of chemistry and has been extensively investigated since its discovery. We introduce here the description of central chirality for tetrahedral molecules using a geometrical approach based on complex numbers. According to this representation, for a molecule having n chiral centres, it is possible to define an index of chirality. Consequently a chirality selection rule has been derived which allows the characterization of a molecule as achiral, e...

  4. Finite density two color chiral perturbation theory revisited

    Science.gov (United States)

    Adhikari, Prabal; Beleznay, Soma B.; Mannarelli, Massimo

    2018-06-01

    We revisit two-color, two-flavor chiral perturbation theory at finite isospin and baryon density. We investigate the phase diagram obtained varying the isospin and the baryon chemical potentials, focusing on the phase transition occurring when the two chemical potentials are equal and exceed the pion mass (which is degenerate with the diquark mass). In this case, there is a change in the order parameter of the theory that does not lend itself to the standard picture of first order transitions. We explore this phase transition both within a Ginzburg-Landau framework valid in a limited parameter space and then by inspecting the full chiral Lagrangian in all the accessible parameter space. Across the phase transition between the two broken phases the order parameter becomes an SU(2) doublet, with the ground state fixing the expectation value of the sum of the magnitude squared of the pion and the diquark fields. Furthermore, we find that the Lagrangian at equal chemical potentials is invariant under global SU(2) transformations and construct the effective Lagrangian of the three Goldstone degrees of freedom by integrating out the radial fluctuations.

  5. Applications of chiral symmetry

    International Nuclear Information System (INIS)

    Pisarski, R.D.

    1995-03-01

    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 T χ implies that the ρ and a 1 vector mesons are degenerate in mass. In a gauged linear sigma model the ρ mass increases with temperature, m ρ (T χ ) > m ρ (0). The author conjectures that at T χ the thermal ρ - a 1 , 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 T χ . 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

  6. Chiral bag model

    International Nuclear Information System (INIS)

    Musakhanov, M.M.

    1980-01-01

    The chiral bag model is considered. It is suggested that pions interact only with the surface of a quark ''bag'' and do not penetrate inside. In the case of a large bag the pion field is rather weak and goes to the linearized chiral bag model. Within that model the baryon mass spectrum, β decay axial constant, magnetic moments of baryons, pion-baryon coupling constants and their form factors are calculated. It is shown that pion corrections to the calculations according to the chiral bag model is essential. The obtained results are found to be in a reasonable agreement with the experimental data

  7. The covariant chiral ring

    Energy Technology Data Exchange (ETDEWEB)

    Bourget, Antoine; Troost, Jan [Laboratoire de Physique Théorique, École Normale Supérieure, 24 rue Lhomond, 75005 Paris (France)

    2016-03-23

    We construct a covariant generating function for the spectrum of chiral primaries of symmetric orbifold conformal field theories with N=(4,4) supersymmetry in two dimensions. For seed target spaces K3 and T{sup 4}, the generating functions capture the SO(21) and SO(5) representation theoretic content of the chiral ring respectively. Via string dualities, we relate the transformation properties of the chiral ring under these isometries of the moduli space to the Lorentz covariance of perturbative string partition functions in flat space.

  8. Spectral signatures of chirality

    DEFF Research Database (Denmark)

    Pedersen, Jesper Goor; Mortensen, Asger

    2009-01-01

    We present a new way of measuring chirality, via the spectral shift of photonic band gaps in one-dimensional structures. We derive an explicit mapping of the problem of oblique incidence of circularly polarized light on a chiral one-dimensional photonic crystal with negligible index contrast...... to the formally equivalent problem of linearly polarized light incident on-axis on a non-chiral structure with index contrast. We derive analytical expressions for the first-order shifts of the band gaps for negligible index contrast. These are modified to give good approximations to the band gap shifts also...

  9. Chiral symmetry breaking and nonperturbative scale anomaly in gauge field theories

    International Nuclear Information System (INIS)

    Miranskij, V.A.; Gusynin, V.P.

    1987-01-01

    The nonperturbative dynamics of chiral and scale symmetry breaking in asymtotically free and non-asymptotically free (with an ultraviolet stable fixed point) vector-like gauge theories is investigated. In the two-loop approximation analytical expressions for the chiral and gluon condensates are obtained. The hypothesis about a soft behaviour at small distances of composite operators in non-asymptotically free gauge theories with a fixed point is put forward and substantiated. It is shown that in these theories the form of the scale anomaly depends on the type of the phase in coupling constant to which it relates. A new dilaton effective lagrangian for glueball and chiral fields is suggested. The mass relation for the single scalar fermion-antifermion bound state is obtained. The important ingredient of this approach is a large (d≅ 2) dynamical dimension of composite chiral fields. The application of this approach to QCD and technicolour models is discussed

  10. S-equivalents lagrangians in generalized mechanics

    International Nuclear Information System (INIS)

    Negri, L.J.; Silva, Edna G. da.

    1985-01-01

    The problem of s-equivalent lagrangians is considered in the realm of generalized mechanics. Some results corresponding to the ordinary (non-generalized) mechanics are extended to the generalized case. A theorem for the reduction of the higher order lagrangian description to the usual order is found to be useful for the analysis of generalized mechanical systems and leads to a new class of equivalence between lagrangian functions. Some new perspectives are pointed out. (Author) [pt

  11. Chiral near-fields around chiral dolmen nanostructure

    International Nuclear Information System (INIS)

    Fu, Tong; Wang, Tiankun; Chen, Yuyan; Wang, Yongkai; Qu, Yu; Zhang, Zhongyue

    2017-01-01

    Discriminating the handedness of the chiral molecule is of great importance in the field of pharmacology and biomedicine. Enhancing the chiral near-field is one way to increase the chiral signal of chiral molecules. In this paper, the chiral dolmen nanostructure (CDN) is proposed to enhance the chiral near-field. Numerical results show that the CDN can increase the optical chirality of the near-field by almost two orders of magnitude compared to that of a circularly polarized incident wave. In addition, the optical chirality of the near-field of the bonding mode is enhanced more than that of the antibonding mode. These results provide an effective method for tailoring the chiral near-field for biophotonics sensors. (paper)

  12. Chiral Gold Nanoclusters: Atomic Level Origins of Chirality.

    Science.gov (United States)

    Zeng, Chenjie; Jin, Rongchao

    2017-08-04

    Chiral nanomaterials have received wide interest in many areas, but the exact origin of chirality at the atomic level remains elusive in many cases. With recent significant progress in atomically precise gold nanoclusters (e.g., thiolate-protected Au n (SR) m ), several origins of chirality have been unveiled based upon atomic structures determined by using single-crystal X-ray crystallography. The reported chiral Au n (SR) m structures explicitly reveal a predominant origin of chirality that arises from the Au-S chiral patterns at the metal-ligand interface, as opposed to the chiral arrangement of metal atoms in the inner core (i.e. kernel). In addition, chirality can also be introduced by a chiral ligand, manifested in the circular dichroism response from metal-based electronic transitions other than the ligand's own transition(s). Lastly, the chiral arrangement of carbon tails of the ligands has also been discovered in a very recent work on chiral Au 133 (SR) 52 and Au 246 (SR) 80 nanoclusters. Overall, the origins of chirality discovered in Au n (SR) m nanoclusters may provide models for the understanding of chirality origins in other types of nanomaterials and also constitute the basis for the development of various applications of chiral nanoparticles. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Looking hard at the electroweak force

    International Nuclear Information System (INIS)

    Baur, Ulrich; Errede, Steven; Mueller, Thomas

    1995-01-01

    While recent experiments have beautifully confirmed many of the predictions of the electroweak unification of electromagnetism and the weak nuclear force, some direct consequences of the electroweak symmetry involve special properties of the three force carriers - the electrically charged W and neutral Z carrying the weak force and the photon of electromagnetism. These special properties have yet to be measured accurately. In the electroweak picture these force carriers (vector bosons) can interact with each other. These properties are 'non-abelian' - they are dependent on the order in which they are applied. [Most operations can be applied in any order, for example simple arithmetic: 6x(3+2) = (6x3)+(6x2). These are 'abelian'. An example of a non-abelian operator is the logarithm: log(x+y) does not equal log(x) + log(y).] Summarizing the current theoretical and experimental understanding of these self-interactions, and discussing the prospects of measuring them in future experiments, was the purpose of the ''International Symposium on Vector Boson Self-Interactions'' held earlier this year at UCLA, the first meeting entirely devoted to this topic. Progress in measuring the selfcouplings of vector bosons has been fueled recently by the CDF and DO Collaborations at Fermilab's protonantiproton collider. Using data from vector boson pair production, these studies are extracting information on the WW-photon, WWZ and ZZphoton interactions, as well as the magnetic and electric quadrupole moments of the W boson. At UCLA, Hiro Aihara (Berkeley) and Theresa Fuess (Argonne) summarized the CDF and DO results from the 1992-93 run. Information on potential ZZ-gamma interactions can also be gained from single photon production at CERN's LEP electronpositron collider, as detailed by Peter Maettig (Bonn), and from rare B meson decays, reviewed by Steve Playfer (Syracuse)

  14. Alternative kinetic energy metrics for Lagrangian systems

    Science.gov (United States)

    Sarlet, W.; Prince, G.

    2010-11-01

    We examine Lagrangian systems on \\ {R}^n with standard kinetic energy terms for the possibility of additional, alternative Lagrangians with kinetic energy metrics different to the Euclidean one. Using the techniques of the inverse problem in the calculus of variations we find necessary and sufficient conditions for the existence of such Lagrangians. We illustrate the problem in two and three dimensions with quadratic and cubic potentials. As an aside we show that the well-known anomalous Lagrangians for the Coulomb problem can be removed by switching on a magnetic field, providing an appealing resolution of the ambiguous quantizations of the hydrogen atom.

  15. Structure of pheomenological lagrangians for broken supersymmetry

    International Nuclear Information System (INIS)

    Uematsu, T.; Zachos, C.K.

    1982-01-01

    We consider the explicit connection between linear representations of supersymetry and the non-linear realizations associated with the generic effective lagrangians of the Volkov-Akulov type. We specify and illustrate a systematic approach for deriving the appropriate phenomenological lagrangian by transforming a pedagogical linear model, in which supersymmetry is broken at the tree level, into its corresponding non-linear lagrangian, in close analogy to the linear sigma model of pion dynamics. We discuss the significance and some properties of such phenomenological lagrangians. (orig.)

  16. Nonunitary Lagrangians and Unitary Non-Lagrangian Conformal Field Theories

    Science.gov (United States)

    Buican, Matthew; Laczko, Zoltan

    2018-02-01

    In various dimensions, we can sometimes compute observables of interacting conformal field theories (CFTs) that are connected to free theories via the renormalization group (RG) flow by computing protected quantities in the free theories. On the other hand, in two dimensions, it is often possible to algebraically construct observables of interacting CFTs using free fields without the need to explicitly construct an underlying RG flow. In this Letter, we begin to extend this idea to higher dimensions by showing that one can compute certain observables of an infinite set of unitary strongly interacting four-dimensional N =2 superconformal field theories (SCFTs) by performing simple calculations involving sets of nonunitary free four-dimensional hypermultiplets. These free fields are distant cousins of the Majorana fermion underlying the two-dimensional Ising model and are not obviously connected to our interacting theories via an RG flow. Rather surprisingly, this construction gives us Lagrangians for particular observables in certain subsectors of many "non-Lagrangian" SCFTs by sacrificing unitarity while preserving the full N =2 superconformal algebra. As a by-product, we find relations between characters in unitary and nonunitary affine Kac-Moody algebras. We conclude by commenting on possible generalizations of our construction.

  17. Nonunitary Lagrangians and Unitary Non-Lagrangian Conformal Field Theories.

    Science.gov (United States)

    Buican, Matthew; Laczko, Zoltan

    2018-02-23

    In various dimensions, we can sometimes compute observables of interacting conformal field theories (CFTs) that are connected to free theories via the renormalization group (RG) flow by computing protected quantities in the free theories. On the other hand, in two dimensions, it is often possible to algebraically construct observables of interacting CFTs using free fields without the need to explicitly construct an underlying RG flow. In this Letter, we begin to extend this idea to higher dimensions by showing that one can compute certain observables of an infinite set of unitary strongly interacting four-dimensional N=2 superconformal field theories (SCFTs) by performing simple calculations involving sets of nonunitary free four-dimensional hypermultiplets. These free fields are distant cousins of the Majorana fermion underlying the two-dimensional Ising model and are not obviously connected to our interacting theories via an RG flow. Rather surprisingly, this construction gives us Lagrangians for particular observables in certain subsectors of many "non-Lagrangian" SCFTs by sacrificing unitarity while preserving the full N=2 superconformal algebra. As a by-product, we find relations between characters in unitary and nonunitary affine Kac-Moody algebras. We conclude by commenting on possible generalizations of our construction.

  18. Electroweak Symmetry Breaking (3/3)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The focus of the lectures will be on the role of the Higgs boson in the mechanism of electroweak symmetry breaking, both in the Standard Model and in models of New Physics. In particular, I will discuss how a determination of its couplings to matter and gauge fields can give important information on the nature and origin of the Higgs boson. I will thus review the picture on Higgs couplings implied by the current experimental data and examine further interesting processes that can be measured in the future.

  19. Electroweak Symmetry Breaking (2/3)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The focus of the lectures will be on the role of the Higgs boson in the mechanism of electroweak symmetry breaking, both in the Standard Model and in models of New Physics. In particular, I will discuss how a determination of its couplings to matter and gauge fields can give important information on the nature and origin of the Higgs boson. I will thus review the picture on Higgs couplings implied by the current experimental data and examine further interesting processes that can be measured in the future.

  20. Electroweak Symmetry Breaking (1/3)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The focus of the lectures will be on the role of the Higgs boson in the mechanism of electroweak symmetry breaking, both in the Standard Model and in models of New Physics. In particular, I will discuss how a determination of its couplings to matter and gauge fields can give important information on the nature and origin of the Higgs boson. I will thus review the picture on Higgs couplings implied by the current experimental data and examine further interesting processes that can be measured in the future.

  1. Electroweak physics at the Tevatron collider

    International Nuclear Information System (INIS)

    Aihara, H.

    1993-08-01

    Preliminary results on electroweak physics from the 1992--1993 run with the CDF and D0 detectors at the Tevatron collider are presented. New measurements of the ratio of the W and Z production cross sections times the branching fractions for subsequent decay into leptons are shown. The W width, Γ(W), and a limit on the top-quark mass independent of decay mode are extracted. The status of a measurement of the charge asymmetry of electrons from W decay is given. Also shown are a study of diboson (Wγ, Zγ and WZ) production and a search for a new neutral gauge boson (Z')

  2. Electroweak baryogenesis and the standard model

    International Nuclear Information System (INIS)

    Huet, P.

    1994-01-01

    Electroweak baryogenesis is addressed within the context of the standard model of particle physics. Although the minimal standard model has the means of fulfilling the three Sakharov's conditions, it falls short to explaining the making of the baryon asymmetry of the universe. In particular, it is demonstrated that the phase of the CKM mixing matrix is an, insufficient source of CP violation. The shortcomings of the standard model could be bypassed by enlarging the symmetry breaking sector and adding a new source of CP violation

  3. The renormalization of the electroweak standard model

    International Nuclear Information System (INIS)

    Boehm, M.; Spiesberger, H.; Hollik, W.

    1984-03-01

    A renormalization scheme for the electroweak standard model is presented in which the electric charge and the masses of the gauge bosons, Higgs particle and fermions are used as physical parameters. The photon is treated such that quantum electrodynamics is contained in the usual form. Field renormalization respecting the gauge symmetry gives finite Green functions. The Ward identities between the Green functions of the unphysical sector allow a renormalization that maintains the simple pole structure of the propagators. Explicit results for the renormalization self energies and vertex functions are given. They can be directly used as building blocks for the evaluation of l-loop radiative corrections. (orig.)

  4. Electroweak symmetry breaking beyond the Standard Model

    International Nuclear Information System (INIS)

    Bhattacharyya, Gautam

    2012-01-01

    In this paper, two key issues related to electroweak symmetry breaking are addressed. First, how fine-tuned different models are that trigger this phenomenon? Second, even if a light Higgs boson exists, does it have to be necessarily elementary? After a brief introduction, the fine-tuning aspects of the MSSM, NMSSM, generalized NMSSM and GMSB scenarios shall be reviewed, then the little Higgs, composite Higgs and the Higgsless models shall be compared. Finally, a broad overview will be given on where we stand at the end of 2011. (author)

  5. Constraining Lorentz Violation in Electroweak Physics

    Science.gov (United States)

    Lehnert, Ralf

    2018-01-01

    For practical reasons, the majority of past Lorentz tests has involved stable or quasistable particles, such as photons, neutrinos, electrons, protons, and neutrons. Similar efforts in the electroweak sector have only recently taken shape. Within this context, Lorentz-violation searches in the Standard-Model Extension’s Z-Boson sector will be discussed. It is argued that existing precision data on polarized electron-electron scattering can be employed to extract the first conservative two-sided limits on Lorentz breakdown in this sector at the level of 10-7.

  6. arXiv Chiral Effective Theory of Dark Matter Direct Detection

    CERN Document Server

    Bishara, Fady

    2017-02-03

    We present the effective field theory for dark matter interactions with the visible sector that is valid at scales of O(1 GeV). Starting with an effective theory describing the interactions of fermionic and scalar dark matter with quarks, gluons and photons via higher dimension operators that would arise from dimension-five and dimension-six operators above electroweak scale, we perform a nonperturbative matching onto a heavy baryon chiral perturbation theory that describes dark matter interactions with light mesons and nucleons. This is then used to obtain the coefficients of the nuclear response functions using a chiral effective theory description of nuclear forces. Our results consistently keep the leading contributions in chiral counting for each of the initial Wilson coefficients.

  7. Pure chiral optical fibres.

    Science.gov (United States)

    Poladian, L; Straton, M; Docherty, A; Argyros, A

    2011-01-17

    We investigate the properties of optical fibres made from chiral materials, in which a contrast in optical activity forms the waveguide, rather than a contrast in the refractive index; we refer to such structures as pure chiral fibres. We present a mathematical formulation for solving the modes of circularly symmetric examples of such fibres and examine the guidance and polarisation properties of pure chiral step-index, Bragg and photonic crystal fibre designs. Their behaviour is shown to differ for left- and right-hand circular polarisation, allowing circular polarisations to be isolated and/or guided by different mechanisms, as well as differing from equivalent non-chiral fibres. The strength of optical activity required in each case is quantified.

  8. Relativistic Chiral Kinetic Theory

    International Nuclear Information System (INIS)

    Stephanov, Mikhail

    2016-01-01

    This very brief review of the recent progress in chiral kinetic theory is based on the results of Refs. [J.-Y. Chen, D. T. Son, M. A. Stephanov, H.-U. Yee, Y. Yin, Lorentz Invariance in Chiral Kinetic Theory, Phys. Rev. Lett. 113 (18) (2014) 182302. doi: (10.1103/PhysRevLett.113.182302); J.-Y. Chen, D. T. Son, M. A. Stephanov, Collisions in Chiral Kinetic Theory, Phys. Rev. Lett. 115 (2) (2015) 021601. doi: (10.1103/PhysRevLett.115.021601); M. A. Stephanov, H.-U. Yee, The no-drag frame for anomalous chiral fluid, Phys. Rev. Lett. 116 (12) (2016) 122302. doi: (10.1103/PhysRevLett.116.122302)].

  9. Relativistic Chiral Kinetic Theory

    Energy Technology Data Exchange (ETDEWEB)

    Stephanov, Mikhail

    2016-12-15

    This very brief review of the recent progress in chiral kinetic theory is based on the results of Refs. [J.-Y. Chen, D. T. Son, M. A. Stephanov, H.-U. Yee, Y. Yin, Lorentz Invariance in Chiral Kinetic Theory, Phys. Rev. Lett. 113 (18) (2014) 182302. doi: (10.1103/PhysRevLett.113.182302); J.-Y. Chen, D. T. Son, M. A. Stephanov, Collisions in Chiral Kinetic Theory, Phys. Rev. Lett. 115 (2) (2015) 021601. doi: (10.1103/PhysRevLett.115.021601); M. A. Stephanov, H.-U. Yee, The no-drag frame for anomalous chiral fluid, Phys. Rev. Lett. 116 (12) (2016) 122302. doi: (10.1103/PhysRevLett.116.122302)].

  10. Baryon Chiral Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Becher,

    2002-08-08

    After contrasting the low energy effective theory for the baryon sector with one for the Goldstone sector, I use the example of pion nucleon scattering to discuss some of the progress and open issues in baryon chiral perturbation theory.

  11. ((ε')/(ε)) and the electroweak penguin contribution

    International Nuclear Information System (INIS)

    Cirigliano, V.; Donoghue, J.F.; Golowich, E.; Maltman, K.

    2003-01-01

    Our dispersive sum rule calculation of the electroweak penguin contribution to ((ε')/(ε)) is reviewed. A more recent analysis based on the finite-energy sum rule approach is described. Finally, a new determination of the electroweak penguin contribution to ((ε')/(ε)) is presented

  12. Searches for Electroweak SUSY by ATLAS and CMS

    CERN Document Server

    Khoo, Teng Jian; The ATLAS collaboration

    2018-01-01

    While strongly-produced SUSY and third-generation squark searches have already breached the TeV mass range, direct production of electroweak gauginos is less tightly constrained. New searches are presented, showcasing novel strategies for filling in the gaps in sensitivity to electroweak SUSY at ATLAS and CMS.

  13. Generalized chiral perturbation theory

    International Nuclear Information System (INIS)

    Knecht, M.; Stern, J.

    1994-01-01

    The Generalized Chiral Perturbation Theory enlarges the framework of the standard χPT (Chiral Perturbation Theory), relaxing certain assumptions which do not necessarily follow from QCD or from experiment, and which are crucial for the usual formulation of the low energy expansion. In this way, experimental tests of the foundations of the standard χPT become possible. Emphasis is put on physical aspects rather than on formal developments of GχPT. (author). 31 refs

  14. Generalized chiral membrane dynamics

    International Nuclear Information System (INIS)

    Cordero, R.; Rojas, E.

    2003-01-01

    We develop the dynamics of the chiral superconducting membranes (with null current) in an alternative geometrical approach. Besides of this, we show the equivalence of the resulting description with the one known Dirac-Nambu-Goto (DNG) case. Integrability for chiral string model is obtained using a proposed light-cone gauge. In a similar way, domain walls are integrated by means of a simple Ansatz. (Author)

  15. Quenched chiral logarithms

    International Nuclear Information System (INIS)

    Sharpe, S.R.

    1992-04-01

    I develop a diagrammatic method for calculating chiral logarithms in the quenched approximation. While not rigorous, the method is based on physically reasonable assumptions, which can be tested by numerical simulations. The main results are that, at leading order in the chiral expansion, (a) there are no chiral logarithms in quenched f π m u = m d ; (b) the chiral logarithms in B K and related kaon B-parameters are, for m d = m s the same in the quenched approximation as in the full theory (c) for m π and the condensate, there are extra chiral logarithms due to loops containing the η', which lead to a peculiar non-analytic dependence of these quantities on the bare quark mass. Following the work of Gasser and Leutwyler, I discuss how there is a predictable finite volume dependence associated with each chiral logarithm. I compare the resulting predictions with numerical results: for most quantities the expected volume dependence is smaller than the errors. but for B V and B A there is an observed dependence which is consistent with the predictions

  16. Full component Lagrangian in the linear multiplet formulation of string-inspired effective supergravity

    International Nuclear Information System (INIS)

    Giedt, Joel

    2003-01-01

    We compute the component field four-dimensional N = 1 supergravity Lagrangian that is obtained from a superfield Lagrangian in the U(1) K formalism with a linear dilaton multiplet. All fermionic terms are presented. In a variety of important ways, our results generalize those that have been reported previously, and are flexible enough to accommodate many situations of phenomenological interest in string-inspired effective supergravity, especially models based on orbifold compactifications of the weakly coupled heterotic string. We provide for an effective theory of hidden gaugino and matter condensation. We include supersymmetric Green-Schwarz counterterms associated with the cancellation of U(1) and modular duality anomalies; the modular duality counterterm is of a rather general form. Our assumed form for the dilaton Kaehler potential is quite general and can accommodate Kaehler stabilization methods. We note possible applications of our results. We also discuss the usefulness of the linear dilaton formulation as a complement to the chiral dilaton approach

  17. Toy model for two chiral nonets

    International Nuclear Information System (INIS)

    Fariborz, Amir H.; Jora, Renata; Schechter, Joseph

    2005-01-01

    Motivated by the possibility that nonets of scalar mesons might be described as mixtures of 'two quark' and 'four quark' components, we further study a toy model in which corresponding chiral nonets (containing also the pseudoscalar partners) interact with each other. Although the 'two quark' and 'four quark' chiral fields transform identically under SU(3) L xSU(3) R transformations, they transform differently under the U(1) A transformation which essentially counts total (quark+antiquark) content of the mesons. To implement this, we formulate an effective Lagrangian which mocks up the U(1) A behavior of the underlying QCD. We derive generating equations which yield Ward identity type relations based only on the assumed symmetry structure. This is applied to the mass spectrum of the low lying pseudoscalars and scalars, as well as their 'excitations'. Assuming isotopic spin invariance, it is possible to disentangle the amount of 'two quark' vs 'four quark' content in the pseudoscalar π,K,η-type states and in the scalar κ-type states. It is found that a small 'four quark' content in the lightest pseudoscalars is consistent with a large 'four quark' content in the lightest of the scalar κ mesons. The present toy model also allows one to easily estimate the strength of a 'four quark' vacuum condensate. There seems to be a rich and interesting structure

  18. Supersymmetric contribution to the electroweak ρ parameter

    International Nuclear Information System (INIS)

    Drees, M.; Hagiwara, K.

    1990-01-01

    Contributions to the electroweak ρ parameter, the ratio of the neutral- and charged-current strengths at zero-momentum transfer, are studied in the minimal extension of the standard model (SM) with softly broken supersymmetry. The effects of the extended Higgs sector, the gaugino-Higgsino sector, the light-squark--slepton sector and that of the stop-sbottom sector are studied separately, and the role of the custodial SU(2) V symmetry in each sector is clarified. The stop-sbottom sector is found to give potentially a most significant contribution to δρ which can double the standard-model contribution from the top-bottom sector, whereas all the remaining sectors contribute to δρ at the level of at most a few x10 -3 . In the supergravity model with radiative electroweak gauge symmetry breaking there are no extra sources of the SU(2) V breaking at the grand unification scale other than those present already in the SM, and the resulting δρ is found to be significantly smaller than in the general case. Constraints on the allowed range of δρ in the supergravity models are given by taking account of existing and prospective experimental mass limits of additional particles at CERN LEP and Sp bar pS and Fermilab Tevatron

  19. Precision electroweak measurements on the $Z$ resonance

    CERN Document Server

    Schael, S; Brunelière, R; Buskulic, Damir; De Bonis, I; Décamp, D; Ghez, P; Goy, C; Jézéquel, S; Lees, J P; Lucotte, A; Martin, F; Merle, E; Minard, M N; Nief, J Y; Odier, P; Pietrzyk, B; Trocmé, B; Bravo, S; Casado, M P; Chmeissani, M; Comas, P; Crespo, J M; Fernández, E; Fernández-Bosman, M; Garrido, L; Graugès-Pous, E; Juste, A; Martínez, M; Merino, G; Miquel, R; Mir, L M; Orteu, S; Pacheco, A; Park, I C; Perlas, J; Riu, I; Ruiz, H; Sánchez, F; Colaleo, A; Creanza, D; De Filippis, N; De Palma, M; Iaselli, G; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Bazarko, A; Becker, U; Boix, G; Bird, F; Blucher, E; Bonvicini, B; Bright-Thomas, P; Barklow, T; Cattaneo, M; Cerutti, F; Clerbaux, B; Drevermann, H; Forty, R W; Frank, M; Greening, T C; Hagelberg, R; Halley, A W; Gianotti, F; Girone, M; Hansen, J B; Harvey, J; Jacobsen, R; Hutchcroft, D E; Janot, P; Jost, B; Knobloch, J; Kado, M; Lehraus, Ivan; Lazeyras, Pierre; Maley, P; Mato, P; May, J; Moutoussi, A; Pepé-Altarelli, M; Ranjard, F; Rolandi, Luigi; Schlatter, W D; Schmitt, B; Schneider, O; Tejessy, W; Teubert, F; Tomalin, I R; Tournefier, E; Veenhof, R; Valassi, A; Wiedenmann, W; Wright, A E; Ajaltouni, Ziad J; Badaud, F; Chazelle, G; Deschamps, O; Dessagne, S; Falvard, A; Ferdi, C; Fayolle, D; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Pascolo, J M; Perret, P; Podlyski, F; Bertelsen, H; Fernley, T; Hansen, J D; Hansen, J R; Hansen, P H; Kraan, A C; Lindahl, A; Møllerud, R; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, E; Siotis, I; Vayaki, A; Blondel, A; Bonneaud, G; Brient, J C; Machefert, F; Rougé, A; Rumpf, M; Swynghedauw, M; Tanaka, R; Verderi, M; Videau, H L; Ciulli, V; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C H; Antonelli, A; Antonelli, M; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, G P; Passalacqua, L; Picchi, P; Colrain, P; ten Have, I; Hughes, I S; Kennedy, J; Knowles, I G; Lynch, J G; Morton, W T; Negus, P; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Thompson, A S; Turnbull, R M; Wasserbaech, S R; Buchmüller, O L; Cavanaugh, R J; Dhamotharan, S; Geweniger, C; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Tittel, K; Werner, W; Wunsch, M; Beuselinck, R; Binnie, D M; Cameron, W; Davies, G; Dornan, P J; Goodsir, S M; Marinelli, N; Martin, E; Nash, J; Nowell, J; Rutherford, S A; Sedgbeer, J K; Thompson, J C; White, R; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bouhova-Thacker, E; Bowdery, C K; Buck, P G; Clarke, D P; Ellis, G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Keemer, N R; Pearson, M R; Robertson, N A; Sloan, T; Smizanska, M; Snow, S W; Williams, M I; van der Aa, O; Delaere, C; Leibenguth, G; Lemaître, V; Bauerdick, L A T; Blumenschein, U; Van Gemmeren, P; Giehl, I; Hölldorfer, F; Jakobs, K; Kasemann, M; Kayser, F; Kleinknecht, K; Müller, A S; Quast, G; Renk, B; Rohne, E; Sander, H G; Schmeling, S; Wachsmuth, H W; Wanke, R; Zeitnitz, C; Ziegler, T; Aubert, Jean-Jacques; Benchouk, C; Bonissent, A; Carr, J; Coyle, P; Curtil, C; Ealet, A; Etienne, F; Fouchez, D; Motsch, F; Payre, P; Rousseau, D; Talby, M; Thulasidas, M; Aleppo, M; Ragusa, F; Büscher, V; David, A; Dietl, H; Ganis, G; Hüttmann, K; Lütjens, G; Mannert, C; Männer, W; Moser, H G; Settles, R; Seywerd, H; Stenzel, H; Villegas, M; Wolf, G; Boucrot, J; Callot, O; Chen, S; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacholkowska, A; Le Diberder, F R; Lefrançois, J; Mutz, A M; Schune, M H; Serin, L; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Bettarini, S; Boccali, T; Bozzi, C; Calderini, G; Dell'Orso, R; Fantechi, R; Ferrante, I; Fidecaro, F; Foà, L; Giammanco, A; Giassi, A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, F; Rizzo, G; Sanguinetti, G; Sciabà, A; Sguazzoni, G; Spagnolo, P; Steinberger, J; Tenchini, R; Vannini, C; Venturi, A; Verdini, P G; Awunor, O; Blair, G A; Cowan, G; García-Bellido, A; Green, M G; Medcalf, T; Strong, J A; Teixeira-Dias, P; Botterill, David R; Clifft, R W; Edgecock, T R; Edwards, M; Haywood, S J; Norton, P R; Ward, J J; Bloch-Devaux, B; Boumediene, D E; Colas, P; Emery, S; Fabbro, B; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Tuchming, B; Vallage, B; Black, S N; Dann, J H; Kim, H Y; Konstantinidis, N P; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Cartwright, S; Combley, F; Hodgson, P N; Lehto, M H; Thompson, L F; Affholderbach, K; Barberio, E; Böhrer, A; Brandt, S; Burkhardt, H; Feigl, E; Grupen, C; Hess, J; Lutters, G; Meinhard, H; Minguet-Rodríguez, J A; Mirabito, L; Misiejuk, A; Neugebauer, E; Ngac, A; Prange, G; Rivera, F; Saraiva, P; Schäfer, U; Sieler, U; Smolik, L; Stephan, F; Trier, H; Apollonio, M; Borean, C; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Pitis, L; He, H; Kim, H; Pütz, J; Rothberg, J E; Armstrong, S R; Bellantoni, L; Berkelman, K; Cinabro, D; Conway, J S; Cranmer, K; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y; González, S; Grahl, J; Harton, J L; Hayes, O J; Hu, H; Jin, S; Johnson, R P; Kile, J; McNamara, P A; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Sharma, V; Walsh, A M; Walsh, J; Wear, J; Von Wimmersperg-Töller, J H; Wu, J; Wu, S L; Wu, X; Yamartino, J M; Zobernig, G; Dissertori, G; Abdallah, J; Abreu, P; Adam, W; Adye, T; Adzic, P; Ajinenko, I; Albrecht, T; Alderweireld, T; Alekseev, G D; Alemany-Fernandez, R; Allmendinger, T; Allport, P P; Almehed, S; Amaldi, Ugo; Amapane, N; Amato, S; Anashkin, E; Anassontzis, E G; Andersson, P; Andreazza, A; Andringa, S; Anjos, N; Antilogus, P; Apel, W D; Arnoud, Y; Ask, S; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Ballestrero, A; Bambade, P; Barão, F; Barbiellini, G; Barbier, R; Bardin, D; Barker, G; Baroncelli, A; Battaglia, M; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Beillière, P; Belokopytov, Yu A; Belous, K S; Ben-Haim, E; Benekos, N; Benvenuti, A C; Bérat, C; Berggren, M; Berntzon, L; Bertini, D; Bertrand, D; Besançon, M; Besson, N; Bianchi, F; Bigi, M; Bilenky, S M; Bizouard, M A; Bloch, D; Blom, M; Bluj, M; Bonesini, M; Bonivento, W; Boonekamp, M; Booth, P S L; Borgland, A W; Borisov, G; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Boyko, I; Bozovic, I; Bozzo, M; Bracko, M; Branchini, P; Brenke, T; Brenner, R; Brodet, E; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschbeck, Brigitte; Buschmann, P; Cabrera, S; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Carena, F; Carroll, L; Caso, C; Castillo-Gimenez, M V; Castro, N; Cattai, A; Cavallo, F; 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Behnke, T; Bell, A N; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bentvelsen, Stanislaus Cornelius Maria; Berlich, P; Bethke, Siegfried; Biebel, O; Binder, U; Blobel, Volker; Bloodworth, Ian J; Bloomer, J E; Bock, P; Boden, B; Böhme, J; Boeriu, O; Bonacorsi, D; Bosch, H M; Bougerolle, S; Boutemeur, M; Bouwens, B T; Brabson, B B; Braibant, S; Breuker, H; Brigliadori, L; Brown, R M; Brun, R; Bürgin, R; Büsser, K; Burckhart, H J; Burgard, C; Cammin, J; Campana, S; Capiluppi, P; Carnegie, R K; Caron, B; Carter, A A; Carter, J R; Chang, C Y; Charlesworth, C; Charlton, D G; Chrin, J T M; Chrisman, D; Chu, S L; Ciocca, C; Clarke, P E L; Clay, E; Clayton, J C; Cohen, I; Collins, W J; Conboy, J E; Cooke, O C; Cooper, M; Couch, M; Couchman, J; Coupland, M; do Couto e Silva, E; Coxe, R L; Cuffiani, M; Dado, S; Dallapiccola, C; Dallavalle, G M; Dallison, S; Darling, C; De Jong, S; de Roeck, A; De Wolf, E A; Debu, P; Deng, H; Deninno, M M; Dervan, P; Desch, Klaus; Dieckmann, A; Dienes, B; 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Hawkes, C M; Hawkings, R; Heflin, E; Hemingway, R J; Hensel, C; Herten, G; Heuer, R D; Hill, J C; Hillier, S J; Hilse, T; Hinshaw, D A; Ho, C; Hoare, J; Hobbs, J D; Hobson, P R; Hochman, D; Höcker, Andreas; Hoffman, K; Holl, B; Homer, R J; Honma, A K; Horváth, D; Hossain, K R; Howard, R; Howarth, C P; Hüntemeyer, P; Hughes-Jones, R E; Humbert, R; Igo-Kemenes, P; Ihssen, H; Imrie, D C; Ingram, M R; Ishii, K; Jacob, F R; Janissen, A C; Jawahery, A; Jeffreys, P W; Jeremie, H; Jimack, M; Jobes, M; Joly, A; Jones, C R; Jones, G; Jones, M; Jost, U; Jovanovic, P; Jui, C; Kanaya, N; Kanzaki, J; Karapetian, G V; Karlen, D; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Keeler, R K; Kellogg, R G; Kennedy, B W; Kim, D H; King, B J; Kirk, J; Klein, K; Kleinwort, C; Klem, D E; Klier, A; Kluth, S; Kobayashi, T; Kobel, M; Köpke, L; Koetke, D S; Kokott, T P; Komamiya, S; Kormos, L; Kowalewski, R V; Kramer, T; Kral, J F; Kress, T; Kreutzmann, H; Krieger, P; Von Krogh, J; Kroll, J; Krop, D; Krüger, K; Kühl, T; Kupper, M; Kuwano, M; Kyberd, P; Lafferty, G D; Lafoux, H; Lahmann, R; Lai, W P; Lamarche, F; Landsman, H; Lanske, D; Larson, W J; Lauber, J; Lautenschlager, S R; Lawson, I; Layter, J G; Lazic, D; Le Dû, P; Leblanc, P; Lee, A M; Lefebvre, E; Leins, A; Lellouch, D; Lennert, P; Leroy, C; Lessard, L; Letts, J; Levegrün, S; Levinson, L; Lewis, C; Liebisch, R; Lillich, J; Littlewood, C; Lloyd, A W; Lloyd, S L; Loebinger, F K; Long, G D; Lorah, J M; Lorazo, B; Losty, Michael J; Lou, X C; Lü, J; Ludwig, A; Ludwig, J; Luig, A; Macchiolo, A; MacPherson, A; Mader, W; Mättig, P; Malik, A; Mannelli, M; Marcellini, S; Marchant, T E; Maringer, G; Markus, C; Martin, A J; Martínez, G; Masetti, G; Mashimo, T; Matthews, W; Maur, U; McDonald, W J; McGowan, R F; McKenna, J; McKigney, E A; McMahon, T J; McNab, A I; McNutt, J R; McPherson, A C; McPherson, R A; Meijers, F; Méndez-Lorenzo, P; Menges, W; Menke, S; Menszner, D; Merritt, F S; Mes, H; Meyer, J; Meyer, N; Michelini, A; Middleton, R P; Mihara, S; Mikenberg, G; Mildenberger, J; Miller, D J; Milstene, C; Mir, R; Moed, S; Mohr, W; Moisan, C; Montanari, A; Mori, T; Moss, M W; Mouthuy, T; Murphy, P G; Mutter, A; Nagai, K; Nakamura, I; Nanjo, H; Neal, H A; Nellen, B; Nguyen, H H; Nijjhar, B; Nisius, R; Nozaki, M; Oakham, F G; Odorici, F; Ogg, M; Ögren, H O; Oh, A; Oh, H; Okpara, A; Oldershaw, N J; Omori, T; O'Neale, S W; O'Neill, B P; Oram, C J; Oreglia, M J; Orito, S; Pahl, C; Pálinkás, J; Palmonari, F; Pansart, J P; Panzer-Steindel, B; Paschievici, P; Pásztor, G; Pater, J R; Patrick, G N; Pawley, S J; Paz-Jaoshvili, N; Pearce, M J; Petzold, S; Pfeifenschneider, P; Pfister, P; Pilcher, J E; Pinfold, J L; Pitman, D; Plane, D E; Poffenberger, P R; Poli, B; Polok, J; Pooth, O; Posthaus, A; Pouladdej, A; del Pozo, L A; Prebys, E; Pritchard, T W; Przybycien, M B; Przysiezniak, H; Quadt, A; Rabbertz, K; Raith, B; Redmond, M W; Rees, D L; Rembser, C; Renkel, P; Richards, G E; Rick, H; Rigby, D; Robins, S A; Robinson, D; Rodning, N; Rollnik, A; Roney, J M; Rooke, A M; Ros, E; Rosati, S; Roscoe, K; Rossberg, S; Rossi, A M; Rosvick, M; Routenburg, P; Rozen, Y; Runge, K; Runólfsson, O; Ruppel, U; Rust, D R; Rylko, R; Sachs, K; Saeki, T; Sahr, O; Sanghera, S; Sarkisyan-Grinbaum, E; Sasaki, M; Sbarra, C; Schaile, A D; Schaile, O; Schappert, W; Scharf, F; Scharff-Hansen, P; Schenk, P; Schieck, J; von der Schmitt, H; Schmitt, S; Schörner-Sadenius, T; Schreiber, S; Schröder, M; Schütz, P; Schultz-Coulon, H C; Schulz, M; Schumacher, M; Schwarz, J; Schwick, C; Scott, W G; Settles, M; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Shypit, R; Simon, A; Singh, P; Siroli, G P; Sittler, A; Skillman, A; Skuja, A; Smith, A M; Smith, T J; Snow, G A; Sobie, R J; Söldner-Rembold, S; Spagnolo, S; Spanó, F; Springer, R W; Sproston, M; Starks, M; Steiert, M; Stephens, K; Steuerer, J; Stier, H E; Stockhausen, B; Stoll, K; Ströhmer, R; Strom, D; Strumia, F; Stumpf, L; Surrow, B; Szymanski, P; Tafirout, R; Takeda, H; Takeshita, T; Talbot, S D; Tanaka, S; Taras, P; Tarem, S; Tasevsky, M; Taylor, R J; Tecchio, M; Tesch, N; Teuscher, R; Thackray, N J; Thiergen, M; Thomson, M A; Von Törne, E; Towers, S; Toya, D; Trócsányi, Z L; Tran, P; Trefzger, T; Tresilian, N J; Trigger, I; Tscheulin, M; Tsukamoto, T; Tsur, E; Turcot, A S; Turner-Watson, M F; Tysarczyk-Niemeyer, G; Ueda, I; Ujvári, B; Utzat, P; Vachon, B; Van den Plas, D; Van Kooten, R; VanDalen, G J; Vannerem, P; Vasseur, G; Vertesi, R; Verzocchi, M; Vikas, P; Vincter, M G; Virtue, C J; Vokurka, E H; Vollmer, C F; Voss, H; Vossebeld, Joost Herman; Wäckerle, F; Wagner, A; Wagner, D L; Wahl, C; Walker, J P; Waller, D; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Weber, P; Weisz, S; Wells, P S; Wengler, T; Wermes, N; Wetterling, D; Weymann, M; Whalley, M A; White, J S; Wilkens, B; Wilson, J A; Wilson, G W; Wingerter, Isabelle; Winterer, V H; Wood, N C; Wotton, S; Wyatt, T R; Yaari, R; Yamashita, S; Yang, Y; Yeaman, A; Yekutieli, G; Yurko, M; Zacek, V; Zacharov, I E; Zer-Zion, D; Zeuner, W; Zivkovic, L; Zorn, G T; Abe, Kenji; Abe, Koya; Abe, T; Abt, I; Acton, P D; Adam, I; Agnew, G; Akagi, T; Akimoto, H; Allen, N J; Ash, W W; Aston, D; Bacchetta, N; Baird, K G; Baltay, C; Band, H R; Barakat, M B; Baranko, G J; Bardon, O; Barklow, T L; Bashindzhagian, G L; Bauer, J M; Bazarko, A O; Bean, A; Bellodi, G; Ben-David, R; Berger, R; Bienz, T; Bilei, G M; Bisello, D; Blaylock, G; Bogart, J R; Bolen, B; Bolton, T; Bower, G R; Brau, J E; Breidenbach, M; Bugg, W M; Burke, D; Burnett, T H; Burrows, P N; Busza, W; Calcaterra, A; Caldwell, D O; Camanzi, B; Carpinelli, M; Cassell, R; Castaldi, R; Castro, A; Cavalli-Sforza, M; Chadwick, George B; Chou, A; Church, E; Claus, R; Cohn, H O; Coller, J A; Convery, M R; Cook, V; Cotton, R; Cowan, R F; Coyne, D G; Crawford, G; de Oliveira, A; Damerell, C J S; Daoudi, M; Dasu, S; De Groot, N; De Sangro, R; De Simone, P; De Simone, S; Dervan, P J; Dima, M; Dong, D N; Doser, Michael; Du, P Y C; Dubois, R; Duboscq, J E; Eisenstein, B I; Elia, R; Erdos, E; Erofeeva, I; Eschenburg, V; Etzion, E; Fahey, S; Falciai, D; Fan, C; Fernández, J P; Fero, M J; Flood, K; Frey, R; Friedman, Jerome Isaac; Furuno, K; Garwin, E L; Gillman, T; Gladding, G; Hallewell, G D; Hart, E L; Hasegawa, Y; Hasuko, K; Hedges, S; Hertzbach, S S; Hildreth, M D; Hitlin, D G; Honma, A; Huber, J S; Huffer, M E; Hughes, E W; Huynh, X; Hwang, H; Iwasaki, M; Iwasaki, Y; Izen, J M; Jackson, D J; Jacques, P; Jaros, J A; Jiang, Z Y; Johnson, A S; Johnson, J R; Johnson, R A; Junk, T R; Kajikawa, R; Kalelkar, M; Kamyshkov, Yu A; Kang, H J; Karliner, I; Kawahara, H; Kelsey, M H; Kendall, H W; Kim, Y D; King, M; King, R; Kofler, R R; Krishna, N M; Kwon, Y; Labs, J F; Kroeger, R S; Langston, M; Lath, A; Lauber, J A; Leith, D W G S; Lia, V; Lin, C; Liu, M X; Loreti, M; Lu, A; Lynch, H L; Ma, J; Mancinelli, G; Manly, S; Mantovani, G C; Markiewicz, T W; Maruyama, T; Masuda, H; Mazzucato, E; McGowan, J F; McKemey, A K; Meadows, B T; Messner, R; Mockett, P M; Moffeit, K C; Moore, T B; Morii, M; Mours, B; Müller, D; Müller, G; Murzin, V; Nagamine, T; Narita, S; Nauenberg, U; Neal, H; Nesom, G; Nussbaum, M; Ohnishi, Y; Oishi, N; Onoprienko, D; Osborne, L S; Panvini, R S; Park, C H; Park, H; Pavel, T J; Peruzzi, I; Pescara, L; Piccolo, M; Piemontese, L; Pieroni, E; Pitts, K T; Plano, R J; Prepost, R; Prescott, C Y; Punkar, G; Quigley, J; Ratcliff, B N; Reeves, K; Reeves, T W; Reidy, J; Reinertsen, P L; Rensing, P E; Rochester, L S; Rowson, P C; Russell, J J; Saxton, O H; Schalk, T; Schindler, R H; Schneekloth, U; Schumm, B A; Schwiening, J; Seiden, A; Sen, S; Serbo, V V; Shaevitz, M H; Shank, J T; Shapiro, G; Sherden, D J; Shmakov, K D; Simopoulos, C; Sinev, N B; Smith, S R; Smy, M B; Snyder, J A; Sokoloff, M D; Stängle, H; Stahl, A; Stamer, P; Steiner, H; Steiner, R; Strauss, M G; Su, D; Suekane, F; Sugiyama, A; Suzuki, A; Suzuki, S; Swartz, M; Szumilo, A; Takahashi, T; Taylor, F E; Thaler, J J; Thom, J; Torrence, E; Trandafir, A I; Turk, J D; Usher, T; Vavra, J; Vella, E; Venuti, J P; Verdier, R; Wagner, S R; Waite, A P; Walston, S; Wang, J; Watts, S J; Weidemann, A W; Weiss, E R; Whitaker, J S; White, S L; Wickens, F J; Williams, D A; Williams, D C; Williams, S H; Willocq, S; Wilson, R J; Wisniewski, W J; Wittlin, J L; Woods, M; Word, G B; Wright, T R; Wyss, J; Yamamoto, R K; Yang, X Q; Yashima, J; Yellin, S J; Young, C C; Yuta, H; Zapalac, G; Zdarko, R W; Zeitlin, C; Zhou, J

    2006-01-01

    We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLD experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, $MZ$ and $GZ$, and its couplings to fermions, for example the $ ho$ parameter and the effective electroweak mixing angle for leptons, are precisely measured: egin{eqnarray*} MZ & = & 91.1875 pm 0.0021~GeV \\ GZ & = & 2.4952 pm 0.0023~GeV \\ ho_ell & = & 1.0050 pm 0.0010 \\ swsqeffl & =& 0.23153 pm 0.00016 ,. end{eqnarray*} The number of light neutrino species is determined to be $2.9840pm0.0082$, in agreement with the three observed generations of fundamental fermions. The results are compared to the pr...

  20. Electroweak processes in external active media

    CERN Document Server

    Kuznetsov, Alexander

    2013-01-01

    Expanding on the concept of the authors’ previous book “Electroweak Processes in External Electromagnetic Fields,” this new book systematically describes the investigation methods for the effects of external active media, both strong electromagnetic fields and hot dense plasma, in quantum processes. Solving the solar neutrino puzzle in a unique experiment conducted with the help of the heavy-water detector at the Sudbery Neutrino Observatory, along with another neutrino experiments, brings to the fore electroweak physics in an active external medium. It is effectively demonstrated that processes of neutrino interactions with active media of astrophysical objects may lead, under some physical conditions, to such interesting effects as neutrino-driven shockwave revival in a supernova explosion, a “cherry stone shooting” mechanism for pulsar natal kick, and a neutrino pulsar. It is also shown how poor estimates of particle dispersion in external active media sometimes lead to confusion. The book...

  1. Enabling electroweak baryogenesis through dark matter

    International Nuclear Information System (INIS)

    Lewicki, Marek; Rindler-Daller, Tanja; Wells, James D.

    2016-01-01

    We study the impact on electroweak baryogenesis from a swifter cosmological expansion induced by dark matter. We detail the experimental bounds that one can place on models that realize it, and we investigate the modifications of these bounds that result from a non-standard cosmological history. The modifications can be sizeable if the expansion rate of the Universe increases by several orders of magnitude. We illustrate the impact through the example of scalar field dark matter, which can alter the cosmological history enough to enable a strong-enough first-order phase transition in the Standard Model when it is supplemented by a dimension six operator directly modifying the Higgs boson potential. We show that due to the modified cosmological history, electroweak baryogenesis can be realized, while keeping deviations of the triple Higgs coupling below HL-LHC sensitivies. The required scale of new physics to effectuate a strong-enough first order phase transition can change by as much as twenty percent as the expansion rate increases by six orders of magnitude.

  2. Electroweak symmetry breaking: Higgs/whatever

    International Nuclear Information System (INIS)

    Chanowitz, M.S.

    1990-01-01

    In these two lectures the author discusses electroweak symmetry breaking from a general perspective, stressing properties that are model independent and follow just from the assumption that the electroweak interactions are described by a spontaneously broken gauge theory. This means he assumes the Higgs mechanism though not necessarily the existence of Higgs bosons. The first lecture presents the general framework of a spontaneously broken gauge theory: (1) the Higgs mechanism sui generis, with or without Higgs boson(s) and (2) the implications of symmetry and unitarity for the mass scale and interaction strength of the new physics that the Higgs mechanism requires. In addition he reviews a softer theoretical argument based on the naturalness problem which leads to a prejudice against Higgs bosons unless they are supersymmetric. This is a prejudice, not a theorem, and it could be overturned in the future by a clever new idea. In the second lecture he illustrates the general framework by reviewing some specific models: (1) the Weinberg-Salam model of the Higgs sector; (2) the minimal supersymmetric extension of the Weinberg-Salam model; and (3) technicolor as an example of the Higgs mechanism without Higgs bosons. He concludes the second lecture with a discussion of strong WW scattering that must occur if L SB lives above 1 TeV. In particular he describes some of the experimental signals and backgrounds at the SSC. 57 refs., 12 figs

  3. Resonance saturation of the chiral couplings at next-to-leading order in 1/NC

    International Nuclear Information System (INIS)

    Rosell, Ignasi; Ruiz-Femenia, Pedro; Sanz-Cillero, Juan Jose

    2009-01-01

    The precision obtainable in phenomenological applications of chiral perturbation theory is currently limited by our lack of knowledge on the low-energy constants (LECs). The assumption that the most important contributions to the LECs come from the dynamics of the low-lying resonances, often referred to as the resonance saturation hypothesis, has stimulated the use of large-N C resonance Lagrangians in order to obtain explicit values for the LECs. We study the validity of the resonance saturation assumption at the next-to-leading order in the 1/N C expansion within the framework of resonance chiral theory. We find that, by imposing QCD short-distance constraints, the chiral couplings can be written in terms of the resonance masses and couplings and do not depend explicitly on the coefficients of the chiral operators in the Goldstone boson sector of resonance chiral theory. As we argue, this is the counterpart formulation of the resonance saturation statement in the context of the resonance Lagrangian. Going beyond leading order in the 1/N C counting allows us to keep full control of the renormalization scale dependence of the LEC estimates.

  4. On integration over Fermi fields in chiral and supersymmetric theories

    International Nuclear Information System (INIS)

    Vainshtein, A.I.; Zakharov, V.I.

    1982-01-01

    Chiral and supersymmetric theories are considered which cannot be formulated directly in Euclidean space or regularized by means of massive fields in a manifestly gauge invariant fashion. In case of so called real representations a simple recipe is proposed which allows for unambiguous evaluation of the fermionic determinant circumventing the difficulties mentioned. As application of the general technique the effective fermionic interactions induced by instantons of small size within simplest chiral and supesymmetric theories are calculated (SU(2) as the gauge group and one doublet of Weyl spinors or a triplet of Majorana spinors, respectively). In the latter case the effective Lagrangian violates explicitly invariance under supersymmetric transformations on the fermionic and vector fields defined in standard way [ru

  5. A gauge-invariant chiral unitary framework for kaon photo- and electroproduction on the proton

    International Nuclear Information System (INIS)

    Borasoy, B.; Bruns, P.C.; Nissler, R.; Meissner, U.G.

    2007-01-01

    We present a gauge-invariant approach to photoproduction of mesons on nucleons within a chiral unitary framework. The interaction kernel for meson-baryon scattering is derived from the chiral effective Lagrangian and iterated in a Bethe-Salpeter equation. Within the leading-order approximation to the interaction kernel, data on kaon photoproduction from SAPHIR, CLAS and CBELSA/TAPS are analyzed in the threshold region. The importance of gauge invariance and the precision of various approximations in the interaction kernel utilized in earlier works are discussed. (orig.)

  6. Heavy baryon chiral perturbation theory and the spin 3/2 delta resonances

    Energy Technology Data Exchange (ETDEWEB)

    Kambor, J.

    1996-12-31

    Heavy baryon chiral perturbation theory is briefly reviewed, paying particular attention to the role of the spin 3/2 delta resonances. The concept of resonance saturation for the baryonic sector is critically discussed. Starting from a relativistic formulation of the pion-nucleon-delta system, the heavy baryon chiral Lagrangian including spin 3/2 resonances is constructed by means of a 1/m-expansion. The effective theory obtained admits a systematic expansion in terms of soft momenta, the pion mass M{sub {pi}} and the delta-nucleon mass difference {Delta}. (author). 22 refs.

  7. Chiral model predictions for electromagnetic polarizabilities of the nucleon: A 'consumer report'

    International Nuclear Information System (INIS)

    Broniowski, W.

    1992-01-01

    This contribution has two parts: (1) The author critically discusses predictions for the electromagnetic polarizabilities of the nucleon obtained in two different approaches: (a) hedgehog models (HM), such as Skyrmions, chiral quark models, hybrid bags, NJL etc., and (b) chiral perturbation theory (χPT). (2) The author shows new results obtained in HM: N c -counting of polarizabilities, splitting of the neutron and proton polarizabilities (he argues that α n > α p in models with pionic clouds), relevance of dispersive terms in the magnetic polarizability β, important role of the Δ resonance in pionic loops, and the effects of non-minimal substitution terms in the effective lagrangian. 3 refs

  8. Cohomology for Lagrangian systems and Noetherian symmetries

    International Nuclear Information System (INIS)

    Popp, O.T.

    1989-06-01

    Using the theory of sheaves we find some exact sequences describing the locally Lagrangian systems. Using cohomology theory of groups with coefficients in sheaves we obtain some exact sequences describing the Noetherian symmetries. It is shown how the results can be used to find all locally Lagrangian dynamics Noetherian invariant with respect to a given group of kinematical symmetries.(author)

  9. Lagrangian ocean analysis : Fundamentals and practices

    NARCIS (Netherlands)

    van Sebille, Erik; Deleersnijder, E.L.C.; Heemink, A.W.; Griffies, Stepehn M.; Abernathey, Ryan; Adams, Thomas P.; Berloff, Pavel; Biastoch, Arne; Blanke, Bruno; Chassignet, Eric P.; Authors, More

    2018-01-01

    Lagrangian analysis is a powerful way to analyse the output of ocean circulation models and other ocean velocity data such as from altimetry. In the Lagrangian approach, large sets of virtual particles are integrated within the three-dimensional, time-evolving velocity fields. Over several

  10. Effective lagrangian description on discrete gauge symmetries

    International Nuclear Information System (INIS)

    Banks, T.

    1989-01-01

    We exhibit a simple low-energy lagrangian which describes a system with a discrete remnant of a spontaneously broken continuous gauge symmetry. The lagrangian gives a simple description of the effects ascribed to such systems by Krauss and Wilczek: black holes carry discrete hair and interact with cosmic strings, and wormholes cannot lead to violation of discrete gauge symmetries. (orig.)

  11. Lagrangian submanifolds and dynamics on Lie algebroids

    International Nuclear Information System (INIS)

    Leon, Manuel de; Marrero, Juan C; MartInez, Eduardo

    2005-01-01

    In some previous papers, a geometric description of Lagrangian mechanics on Lie algebroids has been developed. In this topical review, we give a Hamiltonian description of mechanics on Lie algebroids. In addition, we introduce the notion of a Lagrangian submanifold of a symplectic Lie algebroid and we prove that the Lagrangian (Hamiltonian) dynamics on Lie algebroids may be described in terms of Lagrangian submanifolds of symplectic Lie algebroids. The Lagrangian (Hamiltonian) formalism on Lie algebroids permits us to deal with Lagrangian (Hamiltonian) functions not defined necessarily on tangent (cotangent) bundles. Thus, we may apply our results to the projection of Lagrangian (Hamiltonian) functions which are invariant under the action of a symmetry Lie group. As a consequence, we obtain that Lagrange-Poincare (Hamilton-Poincare) equations are the Euler-Lagrange (Hamilton) equations associated with the corresponding Atiyah algebroid. Moreover, we prove that Lagrange-Poincare (Hamilton-Poincare) equations are the local equations defining certain Lagrangian submanifolds of symplectic Atiyah algebroids. (topical review)

  12. Lagrangian ocean analysis : Fundamentals and practices

    NARCIS (Netherlands)

    van Sebille, Erik; Griffies, Stephen M.; Abernathey, Ryan; Adams, Thomas P.; Berloff, Pavel; Biastoch, Arne; Blanke, Bruno; Chassignet, Eric P.; Cheng, Yu; Cotter, Colin J.; Deleersnijder, Eric; Döös, Kristofer; Drake, Henri F.; Drijfhout, Sybren; Gary, Stefan F.; Heemink, Arnold W.; Kjellsson, Joakim; Koszalka, Inga Monika; Lange, Michael; Lique, Camille; MacGilchrist, Graeme A.; Marsh, Robert; Mayorga Adame, C. Gabriela; McAdam, Ronan; Nencioli, Francesco; Paris, Claire B.; Piggott, Matthew D.; Polton, Jeff A.; Rühs, Siren; Shah, Syed H.A.M.; Thomas, Matthew D.; Wang, Jinbo; Wolfram, Phillip J.; Zanna, Laure; Zika, Jan D.

    2018-01-01

    Lagrangian analysis is a powerful way to analyse the output of ocean circulation models and other ocean velocity data such as from altimetry. In the Lagrangian approach, large sets of virtual particles are integrated within the three-dimensional, time-evolving velocity fields. Over several decades,

  13. Form of the manifestly covariant Lagrangian

    Science.gov (United States)

    Johns, Oliver Davis

    1985-10-01

    The preferred form for the manifestly covariant Lagrangian function of a single, charged particle in a given electromagnetic field is the subject of some disagreement in the textbooks. Some authors use a ``homogeneous'' Lagrangian and others use a ``modified'' form in which the covariant Hamiltonian function is made to be nonzero. We argue in favor of the ``homogeneous'' form. We show that the covariant Lagrangian theories can be understood only if one is careful to distinguish quantities evaluated on the varied (in the sense of the calculus of variations) world lines from quantities evaluated on the unvaried world lines. By making this distinction, we are able to derive the Hamilton-Jacobi and Klein-Gordon equations from the ``homogeneous'' Lagrangian, even though the covariant Hamiltonian function is identically zero on all world lines. The derivation of the Klein-Gordon equation in particular gives Lagrangian theoretical support to the derivations found in standard quantum texts, and is also shown to be consistent with the Feynman path-integral method. We conclude that the ``homogeneous'' Lagrangian is a completely adequate basis for covariant Lagrangian theory both in classical and quantum mechanics. The article also explores the analogy with the Fermat theorem of optics, and illustrates a simple invariant notation for the Lagrangian and other four-vector equations.

  14. A Lagrangian-dependent metric space

    International Nuclear Information System (INIS)

    El-Tahir, A.

    1989-08-01

    A generalized Lagrangian-dependent metric of the static isotropic spacetime is derived. Its behaviour should be governed by imposing physical constraints allowing to avert the pathological features of gravity at the strong field domain. This would restrict the choice of the Lagrangian form. (author). 10 refs

  15. Lagrangian velocity correlations in homogeneous isotropic turbulence

    International Nuclear Information System (INIS)

    Gotoh, T.; Rogallo, R.S.; Herring, J.R.; Kraichnan, R.H.

    1993-01-01

    The Lagrangian velocity autocorrelation and the time correlations for individual wave-number bands are computed by direct numerical simulation (DNS) using the passive vector method (PVM), and the accuracy of the method is studied. It is found that the PVM is accurate when K max /k d ≥2 where K max is the maximum wave number carried in the simulation and k d is the Kolmogorov wave number. The Eulerian and Lagrangian time correlations for various wave-number bands are compared. At moderate to high wave number the Eulerian time correlation decays faster than the Lagrangian, and the effect of sweep on the former is observed. The time scale of the Eulerian correlation is found to be (kU 0 ) -1 while that of the Lagrangian is [∫ 0 k p 2 E(p)dp] -1/2 . The Lagrangian velocity autocorrelation in a frozen turbulent field is computed using the DIA, ALHDIA, and LRA theories and is compared with DNS measurements. The Markovianized Lagrangian renormalized approximation (MLRA) is compared with the DNS, and good agreement is found for one-time quantities in decaying turbulence at low Reynolds numbers and for the Lagrangian velocity autocorrelation in stationary turbulence at moderate Reynolds number. The effect of non-Gaussianity on the Lagrangian correlation predicted by the theories is also discussed

  16. On the canonical treatment of Lagrangian constraints

    International Nuclear Information System (INIS)

    Barbashov, B.M.

    2001-01-01

    The canonical treatment of dynamic systems with manifest Lagrangian constraints proposed by Berezin is applied to concrete examples: a special Lagrangian linear in velocities, relativistic particles in proper time gauge, a relativistic string in orthonormal gauge, and the Maxwell field in the Lorentz gauge

  17. Lagrangian properties of particles in turbulence

    NARCIS (Netherlands)

    Toschi, F.; Bodenschatz, E.

    2009-01-01

    The Lagrangian description of turbulence is characterized by a unique conceptual simplicity and by an immediate connection with the physics of dispersion and mixing. In this article, we report some motivations behind the Lagrangian description of turbulence and focus on the statistical properties of

  18. On the canonical treatment of Lagrangian constraints

    International Nuclear Information System (INIS)

    Barbashov, B.M.

    2001-01-01

    The canonical treatment of dynamic systems with manifest Lagrangian constraints proposed by Berezin is applied to concrete examples: a specific Lagrangian linear in velocities, relativistic particles in proper time gauge, a relativistic string in orthonormal gauge, and the Maxwell field in the Lorentz gauge

  19. Chiral symmetry and low energy pion-nucleon scattering

    International Nuclear Information System (INIS)

    Coon, S.A.

    1999-01-01

    In these lectures, I examine the effect of the meson factory πN data on the current algebra/PCAC program which describes chiral symmetry breaking in this system. After historical remarks on the current algebra/PCAC versus chiral Lagrangians approaches to chiral symmetry, and description of the need for πN amplitudes with virtual (off-mass-shell) pions in nuclear force models and other nuclear physics problems, I begin with kinematics and isospin aspects of the invariant amplitudes. A detailed introduction to the hadronic vector and axial-vector currents and the hypothesis of partially conserved axial-vector currents (PCAC) follows. I review and test against contemporary data the PCAC predictions of the Goldberger-Treiman relation, and the Adler consistency condition for a πN amplitude. Then comes a detailed description of the current algebra Ward-Takahashi identities in the chiral limit and a brief account of the on-shell current algebra Ward-Takahashi identities. The latter identities form the basis of so-called current algebra models of πN scattering. I then test these models against the contemporary empirical πN amplitudes extrapolated into the subthreshold region via dispersion relations. The scale and the t dependence of the 'sigma term' is determined by the recent data. (author)

  20. The shallow water equations in Lagrangian coordinates

    International Nuclear Information System (INIS)

    Mead, J.L.

    2004-01-01

    Recent advances in the collection of Lagrangian data from the ocean and results about the well-posedness of the primitive equations have led to a renewed interest in solving flow equations in Lagrangian coordinates. We do not take the view that solving in Lagrangian coordinates equates to solving on a moving grid that can become twisted or distorted. Rather, the grid in Lagrangian coordinates represents the initial position of particles, and it does not change with time. We apply numerical methods traditionally used to solve differential equations in Eulerian coordinates, to solve the shallow water equations in Lagrangian coordinates. The difficulty with solving in Lagrangian coordinates is that the transformation from Eulerian coordinates results in solving a highly nonlinear partial differential equation. The non-linearity is mainly due to the Jacobian of the coordinate transformation, which is a precise record of how the particles are rotated and stretched. The inverse Jacobian must be calculated, thus Lagrangian coordinates cannot be used in instances where the Jacobian vanishes. For linear (spatial) flows we give an explicit formula for the Jacobian and describe the two situations where the Lagrangian shallow water equations cannot be used because either the Jacobian vanishes or the shallow water assumption is violated. We also prove that linear (in space) steady state solutions of the Lagrangian shallow water equations have Jacobian equal to one. In the situations where the shallow water equations can be solved in Lagrangian coordinates, accurate numerical solutions are found with finite differences, the Chebyshev pseudospectral method, and the fourth order Runge-Kutta method. The numerical results shown here emphasize the need for high order temporal approximations for long time integrations

  1. Autoamplification of molecular chirality through the induction of supramolecular chirality

    NARCIS (Netherlands)

    van Dijken, Derk Jan; Beierle, John M.; Stuart, Marc C. A.; Szymanski, Wiktor; Browne, Wesley R.; Feringa, Ben L.

    2014-01-01

    The novel concept for the autoamplification of molecular chirality, wherein the amplification proceeds through the induction of supramolecular chirality, is presented. A solution of prochiral, ring-open diarylethenes is doped with a small amount of their chiral, ring-closed counterpart. The

  2. Algebraic study of chiral anomalies

    Indian Academy of Sciences (India)

    Chiral anomalies; gauge theories; bundles; connections; quantum field ... The algebraic structure of chiral anomalies is made globally valid on non-trivial bundles by the introduction of a fixed background connection. ... Current Issue : Vol.

  3. Silver Films with Hierarchical Chirality.

    Science.gov (United States)

    Ma, Liguo; Cao, Yuanyuan; Duan, Yingying; Han, Lu; Che, Shunai

    2017-07-17

    Physical fabrication of chiral metallic films usually results in singular or large-sized chirality, restricting the optical asymmetric responses to long electromagnetic wavelengths. The chiral molecule-induced formation of silver films prepared chemically on a copper substrate through a redox reaction is presented. Three levels of chirality were identified: primary twisted nanoflakes with atomic crystal lattices, secondary helical stacking of these nanoflakes to form nanoplates, and tertiary micrometer-sized circinates consisting of chiral arranged nanoplates. The chiral Ag films exhibited multiple plasmonic absorption- and scattering-based optical activities at UV/Vis wavelengths based on their hierarchical chirality. The Ag films showed chiral selectivity for amino acids in catalytic electrochemical reactions, which originated from their primary atomic crystal lattices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Chiral anomalies and differential geometry

    International Nuclear Information System (INIS)

    Zumino, B.

    1983-10-01

    Some properties of chiral anomalies are described from a geometric point of view. Topics include chiral anomalies and differential forms, transformation properties of the anomalies, identification and use of the anomalies, and normalization of the anomalies. 22 references

  5. Thermal equilibrium during the electroweak phase transition

    International Nuclear Information System (INIS)

    Tetradis, N.

    1991-12-01

    The effective potential for the standard model develops a barrier, at temperatures around the electroweak scale, which separates the minimum at zero field and a deeper non-zero minimum. This could create out of equilibrium conditions by inducing the localization of the Higgs field in a metastable state around zero. In this picture vacuum decay would occur through bubble nucleation. I show that there is an upper bound on the Higgs mass for the above scenario to be realized. The barrier must be high enough to prevent thermal fluctuations of the Higgs expectation value from establishing thermal equilibrium between the two minima. The upper bound is estimated to be lower than the experimental lower limit. This is also imposes constraints on extensions of the standard model constructed in order to generate a strongly first order phase transition. (orig.)

  6. Electroweak scale physics & exotic searches at LHCb

    CERN Document Server

    Lupton, Olli

    2018-01-01

    The LHCb detector is a single-arm forward spectrometer covering the pseudorapidity range 2–5 that is principally designed for the study of b- and c-hadrons, but which is well-suited to a wide variety of electroweak scale measurements and exotic searches that are highly complementary to other experiments at the LHC and elsewhere. Several features of the detector that are crucial for the core flavour physics programme, such as excellent vertex and momentum resolution, and a powerful trigger system, contribute to excellent jet tagging performance and sensitivity to low mass exotic states. LHCb operates at a substantially lower instantaneous luminosity than the general purpose detectors at the LHC, ATLAS and CMS, which results in a clean, low pile-up environment in which to search for physics beyond the Standard Model (SM).

  7. Electroweak Precision Measurements with the ATLAS Detector

    CERN Document Server

    Zhang, Zhiqing; The ATLAS collaboration

    2018-01-01

    With the high integrated luminosities recorded at the LHC and the very good understanding of the ATLAS detector, it is possible to measure electroweak observables to the highest precision. In this talk, we present the tau polarisation, measured in $Z\\to \\tau\\tau$ using 20.3 fb$^{-1}$ of proton proton collision data collected at a centre of mass energy of 8 TeV. The talk also reviews the measurement of forward-background asymmetry based on the triple differential Drell-Yan cross-section obtained with the same data sample, which can be used to extract the weak mixing angle. We conclude with a presentation of the measurement of the $W$-boson mass using 4.6 fb$^{-1}$ data, collected at 7 TeV.

  8. Electroweak effective couplings for future precision experiments

    International Nuclear Information System (INIS)

    Jegerlehner, F.

    2011-01-01

    The leading hadronic effects in electroweak theory derive from vacuum polarization which are non-perturbative hadronic contributions to the running of the gauge couplings, the electromagnetic α em (s)and the SU(2) L coupling α 2 (s). I will report on my recent package alphaQED, which besides the effective fine structure constant α em (s) also allows for a fairly precise calculation of the SU(2) L gauge coupling α 2 (s). I will briefly review the role, future requirements and possibilities. Applied together with the R had package by Harlander and Steinhauser, the package allows to calculate all SM running couplings as well as running sin 2 Θ versions with state-of-the-art accuracy.

  9. Electroweak effective couplings for future precision experiments

    International Nuclear Information System (INIS)

    Jegerlehner, F.; Humboldt-Universitaet, Berlin

    2011-07-01

    The leading hadronic effects in electroweak theory derive from vacuum polarization which are non-perturbative hadronic contributions to the running of the gauge couplings, the electromagnetic α em (s) and the SU(2) L coupling α 2 (s). I report on my recent package alphaQED [1], which besides the effective fine structure constant α em (s) also allows for a fairly precise calculation of the SU(2) L gauge coupling α 2 (s). I will briefly review the role, future requirements and possibilities. Applied together with the Rhad package by Harlander and Steinhauser [2], the package allows to calculate all SM running couplings as well as running sin 2 Θ versions with state-of-the-art accuracy. (orig.)

  10. Fixed target electroweak and hard scattering physics

    International Nuclear Information System (INIS)

    Brock, R.; Brown, C.N.; Montgomery, H.E.; Corcoran, M.D.

    1990-02-01

    The possibilities for future physics and experiments involving weak and electromagnetic interactions, neutrino oscillations, general hard scattering and experiments involving nuclear targets were explored. The studies were limited to the physics accessible using fixed target experimentation. While some of the avenues explored turn out to be relatively unrewarding in the light of competition elsewhere in the world, there are a number of positive conclusions reached about experimentation in the energy range available to the Main Injector and Tevatron. Some of the experiments would benefit from the increased intensity available from the Tevatron utilizing the Main Injector, while some require this increase. Finally, some of the experiments would use the Main Injector low energy, high intensity extracted beams directly. A program of electroweak and hard scattering experiments at fixed target energies retains the potential for important contributions to physics. The key to major parts of this program would appear to be the existence of the Main Injector. 115 refs, 17 figs

  11. Electroweak baryogenesis, large Yukawas and dark matter

    International Nuclear Information System (INIS)

    Provenza, Alessio; Quiros, Mariano; Ullio, Piero

    2005-01-01

    It has recently been shown that the electroweak baryogenesis mechanism is feasible in Standard Model extensions containing extra fermions with large Yukawa couplings. We show here that the lightest of these fermionic fields can naturally be a good candidate for cold dark matter. We find regions in the parameter space where the thermal relic abundance of this particle is compatible with the dark matter density of the Universe as determined by the WMAP experiment. We study direct and indirect dark matter detection for this model and compare with current experimental limits and prospects for upcoming experiments. We find, contrary to the standard lore, that indirect detection searches are more promising than direct ones, and they already exclude part of the parameter space

  12. Metastable electroweak vacuum. Implications for inflation

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, Oleg; Westphal, Alexander [DESY Theory Group, Hamburg (Germany)

    2012-10-15

    Within the Standard Model, the current Higgs and top quark data favor metastability of the electroweak vacuum, although the uncertainties are still significant. The true vacuum is many orders of magnitude deeper than ours and the barrier separating the two is tiny compared to the depth of the well. This raises a cosmological question: how did the Higgs field get trapped in the shallow minimum and why did it stay there during inflation? The Higgs initial conditions before inflation must be fine-tuned to about one part in 10{sup 8} in order for the Higgs field to end up in the right vacuum. In this note, we show that these problems can be resolved if there is a small positive coupling between the Higgs and the inflaton.

  13. Electroweak Precision Measurements with the ATLAS Detector

    CERN Document Server

    Zhang, Zhiqing; The ATLAS collaboration

    2018-01-01

    With the high integrated luminosities recorded at the LHC and the very good understanding of the ATLAS detector, it is possible to measure electroweak observables to the highest precision. In this talk, we review the measurement of the W boson mass using data, collected at 7 TeV. Special focus is drawn on a discussion of the modeling uncertainties and the physics potential of the latest low-mu runs, recorded at a center of mass energy of 5 and 13 TeV at the end of 2017. The talk will also review the measurement of the triple differential Drell-Yan cross-section at 8 TeV, which can be used to extract the weak mixing angle. We conclude with a presentation of the tau polarization, measured in Z->tautau using 20.3/fb of proton proton collision data collected at a center of mass energy of 8 TeV.

  14. Electroweak interactions in a relativistic Fermi gas

    International Nuclear Information System (INIS)

    Vantournhout, K.; Jachowicz, N.; Ryckebusch, J.

    2006-01-01

    We present a relativistic model for computing the neutrino mean free path in neutron matter. In this model, neutron matter is described as a noninteracting Fermi gas in β equilibrium. We present results for the neutrino mean free path for temperatures of 0 to 50 MeV and a broad range of neutrino energies. We show that relativistic effects cause a considerable enhancement of neutrino-scattering cross sections in neutron matter. The influence of the Q 2 dependence in the electroweak form factors and the inclusion of a weak-magnetic term in the hadron current is discussed. The weak-magnetic term in the hadron current is at the origin of some selective spin dependence for the nucleons that are subject to neutrino interactions

  15. Tests of the electroweak theory at LEP

    International Nuclear Information System (INIS)

    Schaile, D.

    1994-01-01

    LEP offers a rich choice of tests of the electroweak theory such as the measurement of hadronic and leptonic cross sections, leptonic forward-backward asymmetries, τ polarization asymmetries, partial widths and forward-backward asymmetries of heavy quark flavours, of the inclusive q anti q charge asymmetry and of final state radiation in hadronic events. We discuss experimental aspects of these measurements and their theoretical parametrization and summarize the results available so far. We present several analyses which reveal specific aspects of the results, such as their constraints on Standard Model parameters and on new particles, the sensitivity to deviations from the Standard Model multiplet structure and an analysis in a framework which provides a model independent search for new physics. (orig.)

  16. Electroweak symmetry breaking: Higgs/whatever

    International Nuclear Information System (INIS)

    Chanowitz, M.S.

    1989-01-01

    In the first of these two lectures the Higgs mechanism is reviewed in its most general form, which does not necessarily require the existence of Higgs bosons. The general consequences of the hypothesis that electroweak symmetry breaking is due to the Higgs mechanism are deduced just from gauge invariance and unitarity. In the second lecture the general properties are illustrated with three specific models: the Weinberg-Salam model, its minimal supersymmetric extension, and technicolor. The second lecture concludes with a discussion of the experiment signals for strong WW scattering, whose presence or absence will allow us to determine whether the symmetry breaking sector lies above or below 1 TeV. 57 refs

  17. Metastable electroweak vacuum. Implications for inflation

    International Nuclear Information System (INIS)

    Lebedev, Oleg; Westphal, Alexander

    2012-10-01

    Within the Standard Model, the current Higgs and top quark data favor metastability of the electroweak vacuum, although the uncertainties are still significant. The true vacuum is many orders of magnitude deeper than ours and the barrier separating the two is tiny compared to the depth of the well. This raises a cosmological question: how did the Higgs field get trapped in the shallow minimum and why did it stay there during inflation? The Higgs initial conditions before inflation must be fine-tuned to about one part in 10 8 in order for the Higgs field to end up in the right vacuum. In this note, we show that these problems can be resolved if there is a small positive coupling between the Higgs and the inflaton.

  18. Chiral Synthons in Pesticide Syntheses

    NARCIS (Netherlands)

    Feringa, Bernard

    1988-01-01

    The use of chiral synthons in the preparation of enantiomerically pure pesticides is described in this chapter. Several routes to chiral synthons based on asymmetric synthesis or on natural products are illustrated. Important sources of chiral building blocks are reviewed. Furthermore the

  19. Electroweak splitting functions and high energy showering

    Science.gov (United States)

    Chen, Junmou; Han, Tao; Tweedie, Brock

    2017-11-01

    We derive the electroweak (EW) collinear splitting functions for the Standard Model, including the massive fermions, gauge bosons and the Higgs boson. We first present the splitting functions in the limit of unbroken SU(2) L × U(1) Y and discuss their general features in the collinear and soft-collinear regimes. These are the leading contributions at a splitting scale ( k T ) far above the EW scale ( v). We then systematically incorporate EW symmetry breaking (EWSB), which leads to the emergence of additional "ultra-collinear" splitting phenomena and naive violations of the Goldstone-boson Equivalence Theorem. We suggest a particularly convenient choice of non-covariant gauge (dubbed "Goldstone Equivalence Gauge") that disentangles the effects of Goldstone bosons and gauge fields in the presence of EWSB, and allows trivial book-keeping of leading power corrections in v/ k T . We implement a comprehensive, practical EW showering scheme based on these splitting functions using a Sudakov evolution formalism. Novel features in the implementation include a complete accounting of ultra-collinear effects, matching between shower and decay, kinematic back-reaction corrections in multi-stage showers, and mixed-state evolution of neutral bosons ( γ/ Z/ h) using density-matrices. We employ the EW showering formalism to study a number of important physical processes at O (1-10 TeV) energies. They include (a) electroweak partons in the initial state as the basis for vector-boson-fusion; (b) the emergence of "weak jets" such as those initiated by transverse gauge bosons, with individual splitting probabilities as large as O (35%); (c) EW showers initiated by top quarks, including Higgs bosons in the final state; (d) the occurrence of O (1) interference effects within EW showers involving the neutral bosons; and (e) EW corrections to new physics processes, as illustrated by production of a heavy vector boson ( W ') and the subsequent showering of its decay products.

  20. Phenomenology of induced electroweak symmetry breaking

    International Nuclear Information System (INIS)

    Chang, Spencer; Galloway, Jamison; Luty, Markus A.; Salvioni, Ennio; Tsai, Yuhsin

    2015-01-01

    We study the phenomenology of models of electroweak symmetry breaking where the Higgs potential is destabilized by a tadpole arising from the coupling to an “auxiliary” Higgs sector. The auxiliary Higgs sector can be either perturbative or strongly coupled, similar to technicolor models. Since electroweak symmetry breaking is driven by a tadpole, the cubic and quartic Higgs couplings can naturally be significantly smaller than their values in the standard model. The theoretical motivation for these models is that they can explain the 125 GeV Higgs mass in supersymmetry without fine-tuning. The auxiliary Higgs sector contains additional Higgs states that cannot decouple from standard model particles, so these models predict a rich phenomenology of Higgs physics beyond the standard model. In this paper we analyze a large number of direct and indirect constraints on these models. We present the current constraints after the 8 TeV run of the LHC, and give projections for the sensitivity of the upcoming 14 TeV run. We find that the strongest constraints come from the direct searches A 0 →Zh, A 0 →tt-bar, with weaker constraints from Higgs coupling fits. For strongly-coupled models, additional constraints come from ρ + →WZ where ρ + is a vector resonance. Our overall conclusion is that a significant parameter space for such models is currently open, allowing values of the Higgs cubic coupling down to 0.4 times the standard model value for weakly coupled models and vanishing cubic coupling for strongly coupled models. The upcoming 14 TeV run of the LHC will stringently test this scenario and we identify several new searches with discovery potential for this class of models.

  1. Lower bound on the electroweak wall velocity from hydrodynamic instability

    Energy Technology Data Exchange (ETDEWEB)

    Mégevand, Ariel; Membiela, Federico Agustín; Sánchez, Alejandro D., E-mail: megevand@mdp.edu.ar, E-mail: membiela@mdp.edu.ar, E-mail: sanchez@mdp.edu.ar [IFIMAR (CONICET-UNMdP), Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Deán Funes (7600) 3350 Mar del Plata (Argentina)

    2015-03-01

    The subsonic expansion of bubbles in a strongly first-order electroweak phase transition is a convenient scenario for electroweak baryogenesis. For most extensions of the Standard Model, stationary subsonic solutions (i.e., deflagrations) exist for the propagation of phase transition fronts. However, deflagrations are known to be hydrodynamically unstable for wall velocities below a certain critical value. We calculate this critical velocity for several extensions of the Standard Model and compare with an estimation of the wall velocity. In general, we find a region in parameter space which gives stable deflagrations as well as favorable conditions for electroweak baryogenesis.

  2. Lower bound on the electroweak wall velocity from hydrodynamic instability

    International Nuclear Information System (INIS)

    Mégevand, Ariel; Membiela, Federico Agustín; Sánchez, Alejandro D.

    2015-01-01

    The subsonic expansion of bubbles in a strongly first-order electroweak phase transition is a convenient scenario for electroweak baryogenesis. For most extensions of the Standard Model, stationary subsonic solutions (i.e., deflagrations) exist for the propagation of phase transition fronts. However, deflagrations are known to be hydrodynamically unstable for wall velocities below a certain critical value. We calculate this critical velocity for several extensions of the Standard Model and compare with an estimation of the wall velocity. In general, we find a region in parameter space which gives stable deflagrations as well as favorable conditions for electroweak baryogenesis

  3. Lower bound on the electroweak wall velocity from hydrodynamic instability

    Energy Technology Data Exchange (ETDEWEB)

    Mégevand, Ariel; Membiela, Federico Agustín; Sánchez, Alejandro D. [IFIMAR (CONICET-UNMdP), Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Deán Funes (7600) 3350 Mar del Plata (Argentina)

    2015-03-27

    The subsonic expansion of bubbles in a strongly first-order electroweak phase transition is a convenient scenario for electroweak baryogenesis. For most extensions of the Standard Model, stationary subsonic solutions (i.e., deflagrations) exist for the propagation of phase transition fronts. However, deflagrations are known to be hydrodynamically unstable for wall velocities below a certain critical value. We calculate this critical velocity for several extensions of the Standard Model and compare with an estimation of the wall velocity. In general, we find a region in parameter space which gives stable deflagrations as well as favorable conditions for electroweak baryogenesis.

  4. Energy helps accuracy: electroweak precision tests at hadron colliders

    CERN Document Server

    Farina, Marco

    2017-09-10

    We show that high energy measurements of Drell-Yan at the LHC can serve as electroweak precision tests. Dimension-6 operators, from the Standard Model Effective Field Theory, modify the high energy behavior of electroweak gauge boson propagators. Existing measurements of the dilepton invariant mass spectrum, from neutral current Drell-Yan at 8 TeV, have comparable sensitivity to LEP. We propose measuring the transverse mass spectrum of charged current Drell-Yan, which can surpass LEP already with 8 TeV data. The 13 TeV LHC will elevate electroweak tests to a new precision frontier.

  5. Energy helps accuracy: Electroweak precision tests at hadron colliders

    Directory of Open Access Journals (Sweden)

    Marco Farina

    2017-09-01

    Full Text Available We show that high energy measurements of Drell–Yan at the LHC can serve as electroweak precision tests. Dimension-6 operators, from the Standard Model Effective Field Theory, modify the high energy behavior of electroweak gauge boson propagators. Existing measurements of the dilepton invariant mass spectrum, from neutral current Drell–Yan at 8 TeV, have comparable sensitivity to LEP. We propose measuring the transverse mass spectrum of charged current Drell–Yan, which can surpass LEP already with 8 TeV data. The 13 TeV LHC will elevate electroweak tests to a new precision frontier.

  6. Holographic Chiral Magnetic Spiral

    International Nuclear Information System (INIS)

    Kim, Keun-Young; Sahoo, Bindusar; Yee, Ho-Ung

    2010-06-01

    We study the ground state of baryonic/axial matter at zero temperature chiral-symmetry broken phase under a large magnetic field, in the framework of holographic QCD by Sakai-Sugimoto. Our study is motivated by a recent proposal of chiral magnetic spiral phase that has been argued to be favored against previously studied phase of homogeneous distribution of axial/baryonic currents in terms of meson super-currents dictated by triangle anomalies in QCD. Our results provide an existence proof of chiral magnetic spiral in strong coupling regime via holography, at least for large axial chemical potentials, whereas we don't find the phenomenon in the case of purely baryonic chemical potential. (author)

  7. One-loop Renormalization of Resonance Chiral Theory with Scalar and Pseudoscalar Resonances

    International Nuclear Information System (INIS)

    Rosell, I.

    2007-01-01

    The divergent part of the generating functional of the Resonance Chiral Theory is evaluated up to one loop when one multiplet of scalar and pseudoscalar resonances are included and interaction terms which couple up to two resonances are considered. Hence we obtain the renormalization of the couplings of the initial Lagrangian and, moreover, the complete list of operators that make this theory finite, at this order

  8. Weak ωNN coupling in the non-linear chiral model

    International Nuclear Information System (INIS)

    Shmatikov, M.

    1988-01-01

    In the non-linear chiral model with the soliton solution stabilized by the ω-meson field the weak ωNN coupling constants are calculated. Applying the vector dominance model for the isoscalar current the constant of the isoscalar P-odd ωNN interaction h ω (0) =0 is obtained while the constant of the isovector (of the Lagrangian of the ωNN interaction proves to be h ω (1) ≅ 1.0x10 -7

  9. Asymmetric chiral colour

    International Nuclear Information System (INIS)

    Cuypers, F.

    1990-01-01

    Chiral colour is considered in a general framework where the coupling constants associated with each SU(3) component are allowed to be different. To reproduce QCD at low energy, gluons and axigluons cannot then be maximally mixed. Present data form e + e - colliders contrains the axigluon mass to values between 50 GeV and 375 GeV whilst the mixing angle is bounded by 13deg and 45deg. The lower limit of the axigluon mass is a definite bound at 90% C.L., whereas the upper limit only applies if chiral colour is to explain the anomalously high rates of hadron production at TRISTAN. (orig.)

  10. Coherent Lagrangian swirls among submesoscale motions.

    Science.gov (United States)

    Beron-Vera, F J; Hadjighasem, A; Xia, Q; Olascoaga, M J; Haller, G

    2018-03-05

    The emergence of coherent Lagrangian swirls (CLSs) among submesoscale motions in the ocean is illustrated. This is done by applying recent nonlinear dynamics tools for Lagrangian coherence detection on a surface flow realization produced by a data-assimilative submesoscale-permitting ocean general circulation model simulation of the Gulf of Mexico. Both mesoscale and submesoscale CLSs are extracted. These extractions prove the relevance of coherent Lagrangian eddies detected in satellite-altimetry-based geostrophic flow data for the arguably more realistic ageostrophic multiscale flow.

  11. A functional LMO invariant for Lagrangian cobordisms

    DEFF Research Database (Denmark)

    Cheptea, Dorin; Habiro, Kazuo; Massuyeau, Gwénaël

    2008-01-01

    Lagrangian cobordisms are three-dimensional compact oriented cobordisms between once-punctured surfaces, subject to some homological conditions. We extend the Le–Murakami–Ohtsuki invariant of homology three-spheres to a functor from the category of Lagrangian cobordisms to a certain category...... of Jacobi diagrams. We prove some properties of this functorial LMO invariant, including its universality among rational finite-type invariants of Lagrangian cobordisms. Finally, we apply the LMO functor to the study of homology cylinders from the point of view of their finite-type invariants....

  12. Chirality: from QCD to condensed matter

    International Nuclear Information System (INIS)

    Kharzeev, D.

    2015-01-01

    This lecture is about chirality and consists of 4 parts. In the first part a general introduction of chirality is given and its implementation in nuclear and particle physics, in particular the chiral magnetic effect, as well as Chirality in quantum materials (CME, optoelectronics, photonics) are discussed. The 2nd lecture is about the chiral magnetic effect. The 3rd lecture deals with the chiral magnetic effect and hydrodynamics and the last part with chirality and light. (nowak)

  13. Chiral algebras for trinion theories

    International Nuclear Information System (INIS)

    Lemos, Madalena; Peelaers, Wolfger

    2015-01-01

    It was recently understood that one can identify a chiral algebra in any four-dimensional N=2 superconformal theory. In this note, we conjecture the full set of generators of the chiral algebras associated with the T n theories. The conjecture is motivated by making manifest the critical affine module structure in the graded partition function of the chiral algebras, which is computed by the Schur limit of the superconformal index for T n theories. We also explicitly construct the chiral algebra arising from the T 4 theory. Its null relations give rise to new T 4 Higgs branch chiral ring relations.

  14. The global electroweak Standard Model fit after the Higgs discovery

    CERN Document Server

    Baak, Max

    2013-01-01

    We present an update of the global Standard Model (SM) fit to electroweak precision data under the assumption that the new particle discovered at the LHC is the SM Higgs boson. In this scenario all parameters entering the calculations of electroweak precision observalbes are known, allowing, for the first time, to over-constrain the SM at the electroweak scale and assert its validity. Within the SM the W boson mass and the effective weak mixing angle can be accurately predicted from the global fit. The results are compatible with, and exceed in precision, the direct measurements. An updated determination of the S, T and U parameters, which parametrize the oblique vacuum corrections, is given. The obtained values show good consistency with the SM expectation and no direct signs of new physics are seen. We conclude with an outlook to the global electroweak fit for a future e+e- collider.

  15. Chiral forces and molecular dissymmetry

    International Nuclear Information System (INIS)

    Mohan, R.

    1992-01-01

    Chiral molecules leading to helical macromolecules seem to preserve information and extend it better. In the biological world RNA is the very paradigm for self-replication, elongation and autocatalytic editing. The nucleic acid itself is not chiral. It acquires its chirality by association with D-sugars. Although the chiral information or selectivity put in by the unit monomer is no longer of much interest to the biologists - they tend to leave it to the Darwinian selection principle to take care of it as illustrated by Frank's model - it is vital to understand the origin of chirality. There are three different approaches for the chiral origin of life: (1) Phenomenological, (2) Electromagnetic molecular and Coriolis forces and (3) Atomic or nuclear force, the neutral weak current. The phenomenological approach involves spontaneous symmetry breaking fluctuations in far for equilibrium systems or nucleation and crystallization. Chance plays a major role in the chiral molecule selected

  16. Chirality in molecular collision dynamics

    Science.gov (United States)

    Lombardi, Andrea; Palazzetti, Federico

    2018-02-01

    Chirality is a phenomenon that permeates the natural world, with implications for atomic and molecular physics, for fundamental forces and for the mechanisms at the origin of the early evolution of life and biomolecular homochirality. The manifestations of chirality in chemistry and biochemistry are numerous, the striking ones being chiral recognition and asymmetric synthesis with important applications in molecular sciences and in industrial and pharmaceutical chemistry. Chiral discrimination phenomena, due to the existence of two enantiomeric forms, very well known in the case of interaction with light, but still nearly disregarded in molecular collision studies. Here we review some ideas and recent advances about the role of chirality in molecular collisions, designing and illustrating molecular beam experiments for the demonstration of chiral effects and suggesting a scenario for a stereo-directional origin of chiral selection.

  17. The Higgs boson resonance width from a chiral Higgs-Yukawa model on the lattice

    International Nuclear Information System (INIS)

    Gerhold, Philipp; Kallarackal, Jim; Humboldt-Universitaet, Berlin; Jansen, Karl

    2011-11-01

    The Higgs boson is a central part of the electroweak theory and is crucial to generate masses for quarks, leptons and the weak gauge bosons. We use a 4-dimensional Euclidean lattice formulation of the Higgs-Yukawa sector of the electroweak model to compute physical quantities in the path integral approach which is evaluated by means of Monte Carlo simulations thus allowing for fully non perturbative calculations. The chiral symmetry of the model is incorporated by using the Neuberger overlap Dirac operator. The here considered Higgs-Yukawa model does not involve the weak gauge bosons and furthermore, only a degenerate doublet of top- and bottom quarks are incorporated. The goal of this work is to study the resonance properties of the Higgs boson and its sensitivity to the strength of the quartic self coupling. (orig.)

  18. Communication: A simplified coupled-cluster Lagrangian for polarizable embedding.

    Science.gov (United States)

    Krause, Katharina; Klopper, Wim

    2016-01-28

    A simplified coupled-cluster Lagrangian, which is linear in the Lagrangian multipliers, is proposed for the coupled-cluster treatment of a quantum mechanical system in a polarizable environment. In the simplified approach, the amplitude equations are decoupled from the Lagrangian multipliers and the energy obtained from the projected coupled-cluster equation corresponds to a stationary point of the Lagrangian.

  19. Communication: A simplified coupled-cluster Lagrangian for polarizable embedding

    International Nuclear Information System (INIS)

    Krause, Katharina; Klopper, Wim

    2016-01-01

    A simplified coupled-cluster Lagrangian, which is linear in the Lagrangian multipliers, is proposed for the coupled-cluster treatment of a quantum mechanical system in a polarizable environment. In the simplified approach, the amplitude equations are decoupled from the Lagrangian multipliers and the energy obtained from the projected coupled-cluster equation corresponds to a stationary point of the Lagrangian

  20. Deformations of Lagrangian subvarieties of holomorphic symplectic manifolds

    OpenAIRE

    Lehn, Christian

    2011-01-01

    We generalize Voisin's theorem on deformations of pairs of a symplectic manifold and a Lagrangian submanifold to the case of Lagrangian normal crossing subvarieties. Partial results are obtained for arbitrary Lagrangian subvarieties. We apply our results to the study of singular fibers of Lagrangian fibrations.

  1. Holographic theories of electroweak symmetry breaking without a Higgs Boson

    International Nuclear Information System (INIS)

    Burdman, Gustavo; Nomura, Yasunori

    2003-01-01

    Recently, realistic theories of electroweak symmetry breaking have been constructed in which the electroweak symmetry is broken by boundary conditions imposed at a boundary of higher dimensional spacetime. These theories have equivalent 4D dual descriptions, in which the electroweak symmetry is dynamically broken by non-trivial infrared dynamics of some gauge interaction, whose gauge coupling (tilde g) and size N satisfy (tilde g) 2 N ∼> 16π 2 . Such theories allow one to calculate electroweak radiative corrections, including the oblique parameters S, T and U, as long as (tilde g) 2 N/16π 2 and N are sufficiently larger than unity. We study how the duality between the 4D and 5D theories manifests itself in the computation of various physical quantities. In particular, we calculate the electroweak oblique parameters in a warped 5D theory where the electroweak symmetry is broken by boundary conditions at the infrared brane. We show that the value of S obtained in the minimal theory exceeds the experimental bound if the theory is in a weakly coupled regime. This requires either an extension of the minimal model or departure from weak coupling. A particularly interesting scenario is obtained if the gauge couplings in the 5D theory take the largest possible values--the value suggested by naive dimensional analysis. We argue that such a theory can provide a potentially consistent picture for dynamical electroweak symmetry breaking: corrections to the electroweak observables are sufficiently small while realistic fermion masses are obtained without conflicting with bounds from flavor violation. The theory contains only the standard model quarks, leptons and gauge bosons below ≅2 TeV, except for a possible light scalar associated with the radius of the extra dimension. At ≅2 TeV increasingly broad string resonances appear. An analysis of top-quark phenomenology and flavor violation is also presented, which is applicable to both the weakly-coupled and strongly

  2. New searches for supersymmetry in electroweak production with CMS

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    The large set of proton-proton collision data recorded in 2016 at a centre-of-mass energy of 13 TeV is the basis for first results on electroweak production of supersymmetric particles in LHC Run 2. CMS results on the production of chargino / neutralino pairs are presented based on the analysis of final states with one or more leptons and interpreted under several assumptions for the decay modes of the electroweak gauginos.

  3. 3-3-1 models at electroweak scale

    International Nuclear Information System (INIS)

    Dias, Alex G.; Montero, J.C.; Pleitez, V.

    2006-01-01

    We show that in 3-3-1 models there exist a natural relation among the SU(3) L coupling constant g, the electroweak mixing angle θ W , the mass of the W, and one of the vacuum expectation values, which implies that those models can be realized at low energy scales and, in particular, even at the electroweak scale. So that, being that symmetries realized in Nature, new physics may be really just around the corner

  4. Concepts of electroweak symmetry breaking and Higgs physics

    International Nuclear Information System (INIS)

    Gomez-Bock, M.; Zerwas, P.M.; RWTH Aachen; Univ. Paris- Sud, Orsay

    2007-12-01

    We present an introduction to the basic concepts of electroweak symmetry breaking and Higgs physics within the Standard Model and its supersymmetric extensions. A brief overview will also be given on alternative mechanisms of electroweak symmetry breaking. In addition to the theoretical basis, the present experimental status of Higgs physics and prospects at the Tevatron, the LHC and e + e - linear colliders are discussed. (orig.)

  5. Concepts of electroweak symmetry breaking and Higgs physics

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Bock, M. [Benemerita Univ., Puebla (Mexico). Inst. de Fisica; Mondragon, M. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Fisica; Muehlleitner, M. [Laboratoire d' Annecy-Le-Vieux de Physique Theorique, 74 (France)]|[CERN - European Organization for Nuclear Research, Geneva (Switzerland). Theory Div.; Spira, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Zerwas, P.M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[RWTH Aachen (Germany). Inst. Theor. Physik E]|[Univ. Paris- Sud, Orsay (France). Laboratoire de Physique Theorique

    2007-12-15

    We present an introduction to the basic concepts of electroweak symmetry breaking and Higgs physics within the Standard Model and its supersymmetric extensions. A brief overview will also be given on alternative mechanisms of electroweak symmetry breaking. In addition to the theoretical basis, the present experimental status of Higgs physics and prospects at the Tevatron, the LHC and e{sup +}e{sup -} linear colliders are discussed. (orig.)

  6. Theory Overview of Electroweak Physics at Hadron Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, John M. [Fermilab

    2016-09-03

    This contribution summarizes some of the important theoretical progress that has been made in the arena of electroweak physics at hadron colliders. The focus is on developments that have sharpened theoretical predictions for final states produced through electroweak processes. Special attention is paid to new results that have been presented in the last year, since LHCP2015, as well as on key issues for future measurements at the LHC.

  7. Insight into the chiral induction in supramolecular stacks through preferential chiral salvation

    NARCIS (Netherlands)

    George, S.J.; Tomovic, Z.; Schenning, A.P.H.J.; Meijer, E.W.

    2011-01-01

    Preferred handedness in the supramolecular chirality of self-assembled achiral oligo(p-phenylenevinylene) (OPV) derivatives is induced by chiral solvents and spectroscopic probing provides insight into the mechanistic aspects of this chiral induction through chiral solvation

  8. Option volatility and the acceleration Lagrangian

    Science.gov (United States)

    Baaquie, Belal E.; Cao, Yang

    2014-01-01

    This paper develops a volatility formula for option on an asset from an acceleration Lagrangian model and the formula is calibrated with market data. The Black-Scholes model is a simpler case that has a velocity dependent Lagrangian. The acceleration Lagrangian is defined, and the classical solution of the system in Euclidean time is solved by choosing proper boundary conditions. The conditional probability distribution of final position given the initial position is obtained from the transition amplitude. The volatility is the standard deviation of the conditional probability distribution. Using the conditional probability and the path integral method, the martingale condition is applied, and one of the parameters in the Lagrangian is fixed. The call option price is obtained using the conditional probability and the path integral method.

  9. Lagrangian-similarity diffusion-deposition model

    International Nuclear Information System (INIS)

    Horst, T.W.

    1979-01-01

    A Lagrangian-similarity diffusion model has been incorporated into the surface-depletion deposition model. This model predicts vertical concentration profiles far downwind of the source that agree with those of a one-dimensional gradient-transfer model

  10. A new proposal for Lagrangian correlation coefficient

    International Nuclear Information System (INIS)

    Altinsoy, N.; Tugrul, A.B.

    2002-01-01

    The statistical description of dispersion in turbulent flow was first considered by Taylor (Proc. London Math. Soc. 20 (1921) 196) and the statistical properties of the field were determined by Lagrangian correlation coefficient R L (τ). Frenkiel (Adv. Appl. Mech. 3 (1953) 61) has proposed several simple forms for R L (τ). Some workers have investigated for a proper form of the Lagrangian correlation coefficient. In this work, a new proposal for the Lagrangian correlation coefficient is proposed and discussed. It can be written in general form with the one of the Frenkiel's (Adv. Appl. Mech. 3 (1953) 61) Lagrangian correlation coefficient. There is very satisfactory agreement between the new correlation and the experiment

  11. Lagrangian Differentiation, Integration and Eigenvalues Problems

    International Nuclear Information System (INIS)

    Durand, L.

    1983-01-01

    Calogero recently proposed a new and very powerful method for the solution of Sturm-Liouville eigenvalue problems based on Lagrangian differentiation. In this paper, some results of a numerical investigation of Calogero's method for physical interesting problems are presented. It is then shown that one can 'invert' his differentiation technique to obtain a flexible, factorially convergent Lagrangian integration scheme which should be useful in a variety of problems, e.g. solution of integral equations

  12. The universal lagrangian and the cosmic evolution

    International Nuclear Information System (INIS)

    El Tahir, A.

    1984-08-01

    By geometrizing Mach's Universe, we derive the most rational form of a Lagrangian which we, hence, call Universal. It contains both linear and nonlinear terms of the scalar curvature R, with constant coefficients which underlie a certain physical meaning. The metric derivable from this Lagrangian is believed to be far advanced from those derived from general relativity. A wave equation describing the overall evolution of the Universe is obtained and discussed. (author)

  13. Problems of vector Lagrangians in field theories

    International Nuclear Information System (INIS)

    Krivsky, I.Yu.; Simulik, V.M.

    1997-01-01

    A vector Lagrange approach to the Dirac spinor field and the relationship between the vector Lagrangians for the spinor and electromagnetic fields are considered. A vector Lagrange approach for the system of interacting electromagnetic B=(B μ υ)=(E-bar,H-bar) and spinor Ψ fields is constructed. New Lagrangians (scalar and vector) for electromagnetic field in terms of field strengths are found. The foundations of two new QED models are formulated

  14. Detecting the chirality for coupled quantum dots

    International Nuclear Information System (INIS)

    Cao Huijuan; Hu Lian

    2008-01-01

    We propose a scheme to detect the chirality for a system consisting of three coupled quantum dots. The chirality is found to be determined by the frequency of the transition between chiral states under the chiral symmetry broken perturbation. The results are important to construct quantum gates and to demonstrate chiral entangle states in the triangle spin dots

  15. Numerical tests of the electroweak phase transition and thermodynamics of the electroweak plasma

    CERN Document Server

    Csikor, Ferenc; Hein, J; Jaster, A; Montvay, István

    1996-01-01

    The finite temperature phase transition in the SU(2) Higgs model at a Higgs boson mass M_H \\simeq 34 GeV is studied in numerical simulations on four-dimensional lattices with time-like extensions up to L_t=5. The effects of the finite volume and finite lattice spacing on masses and couplings are studied in detail. The errors due to uncertainties in the critical hopping parameter are estimated. The thermodynamics of the electroweak plasma near the phase transition is investigated by determining the relation between energy density and pressure.

  16. Electroweak contributions to squark-pair production processes at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Germer, Jan

    2011-04-28

    We study the electroweak (EW) contributions to squark-squark and sbottom-anti-sbottom production processes at the LHC within the framework of the Minimal Supersymmetric Standard Model (MSSM). Aiming at precise theoretical predictions, the EW contributions are considered up to next-to leading order (NLO) which are of O({alpha}{sup 2}{sub s}{alpha}). Since the EW interaction distinguishes flavor and chirality of the initial- and final-state quarks and squarks, respectively, the contributing processes are manifold and their interplay is non-trivial. All technical details needed in order to calculate the NLO EW contributions to the hadronic cross section for the abovementioned processes are given within this dissertation. This includes appropriate regularization and renormalization prescriptions and a proper treatment of mass singularities in order to get ultraviolet finite and infrared and collinear safe observables. Squark-squark production consists of 36 processes and the same amount for anti-squark- anti-squark production. The tree-level EW contributions of O({alpha}{sub s}{alpha}+{alpha}{sup 2}) and the NLO EW contributions are calculated for all processes. Depending on the flavor and chirality of the produced squarks, many interferences between EW-mediated and QCD-mediated diagrams give non-zero contributions at tree-level and NLO EW. While the tree-level EW contributions to the integrated cross section can reach the 20% level, the NLO EW corrections typically lower the LO prediction by a few percent. Sbottom-anti-sbottom pair production exhibits specific features like left-right mixing and the renormalization of the sbottom sector which has to be chosen with care in order to get reliable predictions. In addition, Yukawa couplings get enhanced for large values of tan {beta} with the related need of resummation. This renders the computation of the electroweak contributions substantially different from the corresponding computations for squark-anti- squark and stop

  17. Electroweak contributions to squark-pair production processes at the LHC

    International Nuclear Information System (INIS)

    Germer, Jan

    2011-01-01

    We study the electroweak (EW) contributions to squark-squark and sbottom-anti-sbottom production processes at the LHC within the framework of the Minimal Supersymmetric Standard Model (MSSM). Aiming at precise theoretical predictions, the EW contributions are considered up to next-to leading order (NLO) which are of O(α 2 s α). Since the EW interaction distinguishes flavor and chirality of the initial- and final-state quarks and squarks, respectively, the contributing processes are manifold and their interplay is non-trivial. All technical details needed in order to calculate the NLO EW contributions to the hadronic cross section for the abovementioned processes are given within this dissertation. This includes appropriate regularization and renormalization prescriptions and a proper treatment of mass singularities in order to get ultraviolet finite and infrared and collinear safe observables. Squark-squark production consists of 36 processes and the same amount for anti-squark- anti-squark production. The tree-level EW contributions of O(α s α+α 2 ) and the NLO EW contributions are calculated for all processes. Depending on the flavor and chirality of the produced squarks, many interferences between EW-mediated and QCD-mediated diagrams give non-zero contributions at tree-level and NLO EW. While the tree-level EW contributions to the integrated cross section can reach the 20% level, the NLO EW corrections typically lower the LO prediction by a few percent. Sbottom-anti-sbottom pair production exhibits specific features like left-right mixing and the renormalization of the sbottom sector which has to be chosen with care in order to get reliable predictions. In addition, Yukawa couplings get enhanced for large values of tan β with the related need of resummation. This renders the computation of the electroweak contributions substantially different from the corresponding computations for squark-anti- squark and stop-anti-stop production. The tree-level EW

  18. Neutrino helicity flips via electroweak interactions

    International Nuclear Information System (INIS)

    Gaemers, K.J.F.; Gandhi, R.; Lattimer, J.M.; Department of Earth and Space Sciences, State University of New York, Stony Brook, New York 11794)

    1989-01-01

    Electroweak mechanisms via which neutrinos may flip helicity are examined in detail. Exact and approximate expressions for a variety of flip processes relevant in astrophysics and cosmology, mediated by W, Z, and γ exchange, including their interference, are derived for both Dirac and Majorana neutrinos (with emphasis on the former). It is shown that in general flip and nonflip cross sections differ by more than just a multiplicative factor of m/sub ν/ 2 /4E/sub ν/ 2 contrary to what might be expected and that this additional dependence on helicities can be significant. It is also shown that within the context of the standard model with massive neutrinos, for νe yields νe scattering, σ/sub Z//sup flip//σ/sub γ//sup flip/ ∼ 10 4 , independent of particle masses and energies to a good approximation. As an application, using some general considerations and the fact that the observed bar nu/sub e/ burst from SN 1987A lasted several seconds, these weak-interaction flip cross sections are used to rule out μ and tau neutrino masses above 30 keV. Finally, some other consequences for astrophysics in general and supernovae in particular are briefly discussed

  19. Nonperturbative QCD corrections to electroweak observables

    Energy Technology Data Exchange (ETDEWEB)

    Dru B Renner, Xu Feng, Karl Jansen, Marcus Petschlies

    2011-12-01

    Nonperturbative QCD corrections are important to many low-energy electroweak observables, for example the muon magnetic moment. However, hadronic corrections also play a significant role at much higher energies due to their impact on the running of standard model parameters, such as the electromagnetic coupling. Currently, these hadronic contributions are accounted for by a combination of experimental measurements and phenomenological modeling but ideally should be calculated from first principles. Recent developments indicate that many of the most important hadronic corrections may be feasibly calculated using lattice QCD methods. To illustrate this, we will examine the lattice computation of the leading-order QCD corrections to the muon magnetic moment, paying particular attention to a recently developed method but also reviewing the results from other calculations. We will then continue with several examples that demonstrate the potential impact of the new approach: the leading-order corrections to the electron and tau magnetic moments, the running of the electromagnetic coupling, and a class of the next-to-leading-order corrections for the muon magnetic moment. Along the way, we will mention applications to the Adler function, the determination of the strong coupling constant and QCD corrections to muonic-hydrogen.

  20. Nonperturbative QCD corrections to electroweak observables

    Energy Technology Data Exchange (ETDEWEB)

    Renner, Dru B. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Feng, Xu [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki (Japan); Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Petschlies, Marcus [The Cyprus Institute, Nicosia (Cyprus)

    2012-06-15

    Nonperturbative QCD corrections are important to many low-energy electroweak observables, for example the muon magnetic moment. However, hadronic corrections also play a significant role at much higher energies due to their impact on the running of standard model parameters, such as the electromagnetic coupling. Currently, these hadronic contributions are accounted for by a combination of experimental measurements, effective field theory techniques and phenomenological modeling but ideally should be calculated from first principles. Recent developments indicate that many of the most important hadronic corrections may be feasibly calculated using lattice QCD methods. To illustrate this, we examine the lattice computation of the leading-order QCD corrections to the muon magnetic moment, paying particular attention to a recently developed method but also reviewing the results from other calculations. We then continue with several examples that demonstrate the potential impact of the new approach: the leading-order corrections to the electron and tau magnetic moments, the running of the electromagnetic coupling, and a class of the next-to-leading-order corrections for the muon magnetic moment. Along the way, we mention applications to the Adler function, which can be used to determine the strong coupling constant, and QCD corrections to muonic-hydrogen.

  1. Gravitational waves from the electroweak phase transition

    International Nuclear Information System (INIS)

    Leitao, Leonardo; Mégevand, Ariel; Sánchez, Alejandro D.

    2012-01-01

    We study the generation of gravitational waves in the electroweak phase transition. We consider a few extensions of the Standard Model, namely, the addition of scalar singlets, the minimal supersymmetric extension, and the addition of TeV fermions. For each model we consider the complete dynamics of the phase transition. In particular, we estimate the friction force acting on bubble walls, and we take into account the fact that they can propagate either as detonations or as deflagrations preceded by shock fronts, or they can run away. We compute the peak frequency and peak intensity of the gravitational radiation generated by bubble collisions and turbulence. We discuss the detectability by proposed spaceborne detectors. For the models we considered, runaway walls require significant fine tuning of the parameters, and the gravitational wave signal from bubble collisions is generally much weaker than that from turbulence. Although the predicted signal is in most cases rather low for the sensitivity of LISA, models with strongly coupled extra scalars reach this sensitivity for frequencies f ∼ 10 −4 Hz, and give intensities as high as h 2 Ω GW ∼ 10 −8

  2. Golden Probe of Electroweak Symmetry Breaking

    CERN Document Server

    Chen, Yi; Spiropulu, Maria; Stolarski, Daniel; Vega-Morales, Roberto

    2016-12-09

    The ratio of the Higgs couplings to $WW$ and $ZZ$ pairs, $\\lambda_{WZ}$, is a fundamental parameter in electroweak symmetry breaking as well as a measure of the (approximate) custodial symmetry possessed by the gauge boson mass matrix. We show that Higgs decays to four leptons are sensitive, via tree level/1-loop interference effects, to both the magnitude and, in particular, overall sign of $\\lambda_{WZ}$. Determining this sign requires interference effects, as it is nearly impossible to measure with rate information. Furthermore, simply determining the sign effectively establishes the custodial representation of the Higgs boson. We find that $h\\to4\\ell$ ($4\\ell \\equiv 2e2\\mu, 4e, 4\\mu$) decays have excellent prospects of directly establishing the overall sign at a high luminosity 13 TeV LHC. We also examine the ultimate LHC sensitivity in $h\\to4\\ell$ to the magnitude of $\\lambda_{WZ}$. Our results are independent of other measurements of the Higgs boson couplings and, in particular, largely free of assumpti...

  3. Non-uniform chiral phase in effective chiral quark models

    International Nuclear Information System (INIS)

    Sadzikowski, M.; Broniowski, W.

    2000-01-01

    We analyze the phase diagram in effective chiral quark models (the Nambu-Jona-Lasinio model, the σ-model with quarks) and show that at the mean-field level a phase with a periodically-modulated chiral fields separates the usual phases with broken and restored chiral symmetry. A possible signal of such a phase is the production of multipion jets travelling in opposite directions, with individual pions having momenta of the order of several hundred MeV. This signal can be interpreted in terms of disoriented chiral condensates. (author)

  4. Chiral magnetic effect of light

    Science.gov (United States)

    Hayata, Tomoya

    2018-05-01

    We study a photonic analog of the chiral magnetic (vortical) effect. We discuss that the vector component of magnetoelectric tensors plays a role of "vector potential," and its rotation is understood as "magnetic field" of a light. Using the geometrical optics approximation, we show that "magnetic fields" cause an anomalous shift of a wave packet of a light through an interplay with the Berry curvature of photons. The mechanism is the same as that of the chiral magnetic (vortical) effect of a chiral fermion, so that we term the anomalous shift "chiral magnetic effect of a light." We further study the chiral magnetic effect of a light beyond geometric optics by directly solving the transmission problem of a wave packet at a surface of a magnetoelectric material. We show that the experimental signal of the chiral magnetic effect of a light is the nonvanishing of transverse displacements for the beam normally incident to a magnetoelectric material.

  5. Chiral Responsive Liquid Quantum Dots.

    Science.gov (United States)

    Zhang, Jin; Ma, Junkai; Shi, Fangdan; Tian, Demei; Li, Haibing

    2017-08-01

    How to convert the weak chiral-interaction into the macroscopic properties of materials remains a huge challenge. Here, this study develops highly fluorescent, selectively chiral-responsive liquid quantum dots (liquid QDs) based on the hydrophobic interaction between the chiral chains and the oleic acid-stabilized QDs, which have been designated as (S)-1810-QDs. The fluorescence spectrum and liquidity of thermal control demonstrate the fluorescence properties and the fluidic behavior of (S)-1810-QDs in the solvent-free state. Especially, (S)-1810-QDs exhibit a highly chiral-selective response toward (1R, 2S)-2-amino-1,2-diphenyl ethanol. It is anticipated that this study will facilitate the construction of smart chiral fluidic sensors. More importantly, (S)-1810-QDs can become an attractive material for chiral separation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Approximating chiral quark models with linear σ-models

    International Nuclear Information System (INIS)

    Broniowski, Wojciech; Golli, Bojan

    2003-01-01

    We study the approximation of chiral quark models with simpler models, obtained via gradient expansion. The resulting Lagrangian of the type of the linear σ-model contains, at the lowest level of the gradient-expanded meson action, an additional term of the form ((1)/(2))A(σ∂ μ σ+π∂ μ π) 2 . We investigate the dynamical consequences of this term and its relevance to the phenomenology of the soliton models of the nucleon. It is found that the inclusion of the new term allows for a more efficient approximation of the underlying quark theory, especially in those cases where dynamics allows for a large deviation of the chiral fields from the chiral circle, such as in quark models with non-local regulators. This is of practical importance, since the σ-models with valence quarks only are technically much easier to treat and simpler to solve than the quark models with the full-fledged Dirac sea

  7. Lattice chiral symmetry and the Wess-Zumino model

    International Nuclear Information System (INIS)

    Fujikawa, Kazuo; Ishibashi, Masato

    2002-01-01

    A lattice regularization of the supersymmetric Wess-Zumino model is studied by using Ginsparg-Wilson operators. We recognize a certain conflict between the lattice chiral symmetry and the Majorana condition for Yukawa couplings, or in Weyl representation a conflict between the lattice chiral symmetry and Yukawa couplings. This conflict is also related, though not directly, to the fact that the kinetic (Kaehler) term and the superpotential term are clearly distinguished in the continuum Wess-Zumino model, whereas these two terms are mixed in the Ginsparg-Wilson operators. We illustrate a case where lattice chiral symmetry together with naive Bose-Fermi symmetry is imposed by preserving a SUSY-like symmetry in the free part of the Lagrangian; one-loop level non-renormalization of the superpotential is then maintained for finite lattice spacing, though the finite parts of wave function renormalization deviate from the supersymmetric value. All these properties hold for the general Ginsparg-Wilson algebra independently of the detailed construction of lattice Dirac operators

  8. Chiral colour and axigluons

    International Nuclear Information System (INIS)

    Cuypers, F.

    1989-01-01

    The authors studies the phenomenological implications of the Chiral Colour model which allow him to derive experimental bounds on the axigluon mass or to predict deviations from the Standard Model. After a short introduction to the theory, the author examines the way it modifies the standard decay of quarkonium. Comparison with the observed lifetime of the upsilon allows him to exclude the existence of axigluons lighter than 9 GeV. (Others have since extended the work and were able to increase this limit to 25 GeV.) He then studies the Chiral Colour contribution to the hadronic cross-section in the electron-positron scattering and derive a conservative lower bound of 50 GeV for the axigluon mass. Finally, he predicts observable enhancements of the lifetime and rare decay channels of the Z O in the presence of light axigluons

  9. Chiral Biomarkers in Meteorites

    Science.gov (United States)

    Hoover, Richard B.

    2010-01-01

    The chirality of organic molecules with the asymmetric location of group radicals was discovered in 1848 by Louis Pasteur during his investigations of the rotation of the plane of polarization of light by crystals of sodium ammonium paratartrate. It is well established that the amino acids in proteins are exclusively Levorotary (L-aminos) and the sugars in DNA and RNA are Dextrorotary (D-sugars). This phenomenon of homochirality of biological polymers is a fundamental property of all life known on Earth. Furthermore, abiotic production mechanisms typically yield recemic mixtures (i.e. equal amounts of the two enantiomers). When amino acids were first detected in carbonaceous meteorites, it was concluded that they were racemates. This conclusion was taken as evidence that they were extraterrestrial and produced by abiologically. Subsequent studies by numerous researchers have revealed that many of the amino acids in carbonaceous meteorites exhibit a significant L-excess. The observed chirality is much greater than that produced by any currently known abiotic processes (e.g. Linearly polarized light from neutron stars; Circularly polarized ultraviolet light from faint stars; optically active quartz powders; inclusion polymerization in clay minerals; Vester-Ulbricht hypothesis of parity violations, etc.). This paper compares the measured chirality detected in the amino acids of carbonaceous meteorites with the effect of these diverse abiotic processes. IT is concluded that the levels observed are inconsistent with post-arrival biological contamination or with any of the currently known abiotic production mechanisms. However, they are consistent with ancient biological processes on the meteorite parent body. This paper will consider these chiral biomarkers in view of the detection of possible microfossils found in the Orgueil and Murchison carbonaceous meteorites. Energy dispersive x-ray spectroscopy (EDS) data obtained on these morphological biomarkers will be

  10. On chiral bosonization

    International Nuclear Information System (INIS)

    Bastianelli, F.

    1991-01-01

    We examine the bosonization of chiral fermions in a gravitational background, using a path integral approach. The bosonic model is given by an action proposed some time ago by Floreanini and Jackiw, suitably coupled to gravity. We use a regulator for the path integral measure obtained from the general construction of Diaz, Hatsuda, Troost, van Nieuwenhuizen and Van Proeyen. We show that the effective actions are identical. (orig.)

  11. Dynamical chiral bag model

    International Nuclear Information System (INIS)

    Colanero, K.; Chu, M.-C.

    2002-01-01

    We study a dynamical chiral bag model, in which massless fermions are confined within an impenetrable but movable bag coupled to meson fields. The self-consistent motion of the bag is obtained by solving the equations of motion exactly assuming spherical symmetry. When the bag interacts with an external meson wave we find three different kinds of resonances: fermionic, geometric, and σ resonances. We discuss the phenomenological implications of our results

  12. Chiral Dynamics 2006

    Science.gov (United States)

    Ahmed, Mohammad W.; Gao, Haiyan; Weller, Henry R.; Holstein, Barry

    2007-10-01

    pt. A. Plenary session. Opening remarks: experimental tests of chiral symmetry breaking / A. M. Bernstein. [Double pie symbols] scattering / H. Leutwyler. Chiral effective field theory in a [Triangle]-resonance region / V. Pascalutsa. Some recent developments in chiral perturbation theory / Ulf-G. Mei ner. Chiral extrapolation and nucleon structure from the lattice / R.D. Young. Recent results from HAPPEX / R. Michaels. Chiral symmetries and low energy searches for new physics / M.J. Ramsey-Musolf. Kaon physics: recent experimental progress / M. Moulson. Status of the Cabibbo angle / V. Cirigliano. Lattice QCD and nucleon spin structure / J.W. Negele. Spin sum rules and polarizabilities: results from Jefferson lab / J-P Chen. Compton scattering and nucleon polarisabilities / Judith A. McGovern. Virtual compton scattering at MIT-bates / R. Miskimen. Physics results from the BLAST detector at the BATES accelerator / R.P. Redwine. The [Pie sympbol]NN system, recent progress / C. Hanhart. Application of chiral nuclear forces to light nuclei / A. Nogga. New results on few-body experiments at low energy / Y. Nagai. Few-body lattice calculations / M.J. Savage. Research opportunities at the upgraded HI?S facility / H.R. Weller -- pt. B. Goldstone boson dynamics. Working group summary: Goldstone Boson dynamics / G. Colangelo and S. Giovannella. Recent results on radiative Kaon decays from NA48 and NA48/2 / S.G. López. Cusps in K-->3 [Pie symbol] decays / B. Kubis. Recent KTeV results on radiative Kaon decays / M.C. Ronquest. The [Double pie symbols] scattering amplitude / J.R. Peláez. Determination of the Regge parameters in the [Double pie symbols] scattering amplitude / I. Caprini. e+e- Hadronic cross section measurement at DA[symbol]NE with the KLOE detector / P. Beltrame. Measurement of the form factors of e+e- -->2([Pie symbol]+[Pie symbol]-), pp and the resonant parameters of the heavy charmonia at BES / H. Hu. Measurement of e+e- multihadronic cross section below 4

  13. A composite model of electroweak interactions and its manifestation at current collider energies

    International Nuclear Information System (INIS)

    Craigie, N.S.

    1984-05-01

    We present a preon model based on an ASF confining gauge theory, which has as a low energy effective Lagrangian, an electroweak gauge theory very close to the standard model. However, it is predicted that there are some specific and necessary deviations from the Glashow-Salam-Weinberg model. In this preon model, we assume a spontaneous breakdown (or an induced breakdown) of the left-right symmetry, which prevents spin-one composites made up of right-handed fermions propagating well below the composite scale of order 1 TeV. A consequence of this assumption is shown to be the existence of a pion-like scalar, in addition to the Higgs particle of the standard model. Such a particle - it is further claimed - can give rise to single photon events, through a large branching ratio into the channel π → Z γ or if lighter than the Z through Z → π(→νν-bar) + γ. The model also predicts a signal very similar to the associated gluino production one of supersymmetric grand unified theories. (author)

  14. Measurement of the electroweak coupling of neutrinos and antineutrinos on electrons

    International Nuclear Information System (INIS)

    Jonker, M.

    1983-01-01

    This thesis describes the analysis of the events induced by elastic scattering of neutrinos and antineutrinos on electrons and interprets the results in terms of the coupling strength of (anti)neutrino on electrons. The data for this analysis were obtained with the electronic calorimeter of the CHARM (Amsterdam, Cern, Hamburg, Moscow, Rome) collaboration during the wide band neutrino beam exposures of 1979, 1980 and 1981 in the neutrino facility of the SPS (Super Proton Synchrotron) at CERN (Conseil Europeen pour la Recherche Nucleaire, Geneva, Switzerland). In chapter 1 a historical overview of the early neutrino physics and a description of the phenomenological Lagrangian is given, followed by an introduction to the electroweak unification model. The neutrino detector of the CHARM collaboration is described in chapter 2. Chapter 3 deals with the on-line monitoring system of this detector which has been under the responsibility of the author. The wide band neutrino facility of the CERN SPS is described in chapter 4, followed by a discussion of the experimental method to measure the neutrino energy spectra of the neutrino beams. The electromagnetic shower development process is reviewed in chapter 5 and is followed by a description of the technique that was used to separate showers of electromagnetic and hadronic origin. Chapter 6 discusses the observed signal of the (anti)neutrinos scattering on electrons and interprets these events in terms of the parameters related to the strength of the coupling of neutrinos to electrons. (Auth.)

  15. Identifying chiral bands in real nuclei

    International Nuclear Information System (INIS)

    Shirinda, O.; Lawrie, E.A.

    2012-01-01

    The application of the presently used fingerprints of chiral bands (originally derived for strongly broken chirality) is investigated for real chiral systems. In particular the chiral fingerprints concerning the B(M1) staggering patterns and the energy staggering are studied. It is found that both fingerprints show considerable changes for real chiral systems, a behaviour that creates a significant risk for misinterpretation of the experimental data and can lead to a failure to identify real chiral systems. (orig.)

  16. Chiral algebras of class S

    CERN Document Server

    Beem, Christopher; Rastelli, Leonardo; van Rees, Balt C.

    2015-01-01

    Four-dimensional N=2 superconformal field theories have families of protected correlation functions that possess the structure of two-dimensional chiral algebras. In this paper, we explore the chiral algebras that arise in this manner in the context of theories of class S. The class S duality web implies nontrivial associativity properties for the corresponding chiral algebras, the structure of which is best summarized in the language of generalized topological quantum field theory. We make a number of conjectures regarding the chiral algebras associated to various strongly coupled fixed points.

  17. Scalar mesons and glueballs in a chiral U(3)xU(3) quark model with 't Hooft interaction

    International Nuclear Information System (INIS)

    Nagy, M.; Volkov, M.K.; Yudichev, V.L.

    2000-01-01

    In a U(3)xU(3) quark chiral model of the Nambu-Jona-Lasino (NJL) type with the 't Hooft interaction, the ground scalar isoscalar mesons and a scalar glueball are described. The glueball (dilaton) is introduced into the effective meson Lagrangian written in a chirally symmetric form on the basis of scale invariance. The singlet-octet mixing of scalar isoscalar mesons and their mixing with the glueball are taken into account. Mass spectra of the scalar mesons and glueball and their strong decays are described

  18. Meaning of the BRS Lagrangian theory

    International Nuclear Information System (INIS)

    Cheng, H.; Tsai, E.

    1989-01-01

    A simplified treatment of the Becchi-Rouet-Stora (BRS) Lagrangian theory is presented. With this treatment we show that the BRS Lagrangian theory in general, and the Feynman-gauge field theory in particular, are effective theories, not the physical theory, and the Feynman gauge is not, strictly speaking, a gauge. The relationship between the quantum states in the BRS Lagrangian theory and those in the physical theory is explicitly given. We also show that one may obtain matrix elements of gauge-invariant operators in the physical theory by calculating corresponding ones in the BRS Lagrangian theory. The formulas which equate such matrix elements are called correspondence formulas. The correspondence formula for the S matrix enables us to equate the scattering amplitudes in the physical theory with those in the BRS Lagrangian theory, thus a proof of the unitary of the Feynman-gauge (as well as other covariant gauges) Feynman rules is rendered unnecessary. This treatment can be applied to various gauge field theories and the examples of the pure Yang-Mills theory and a gauge field theory with a Higgs field is explicitly worked out

  19. A Clifford algebra approach to chiral symmetry breaking and fermion mass hierarchies

    Science.gov (United States)

    Lu, Wei

    2017-09-01

    We propose a Clifford algebra approach to chiral symmetry breaking and fermion mass hierarchies in the context of composite Higgs bosons. Standard model fermions are represented by algebraic spinors of six-dimensional binary Clifford algebra, while ternary Clifford algebra-related flavor projection operators control allowable flavor-mixing interactions. There are three composite electroweak Higgs bosons resulted from top quark, tau neutrino, and tau lepton condensations. Each of the three condensations gives rise to masses of four different fermions. The fermion mass hierarchies within these three groups are determined by four-fermion condensations, which break two global chiral symmetries. The four-fermion condensations induce axion-like pseudo-Nambu-Goldstone bosons and can be dark matter candidates. In addition to the 125 GeV Higgs boson observed at the Large Hadron Collider, we anticipate detection of tau neutrino composite Higgs boson via the charm quark decay channel.

  20. Lagrangian Curves on Spectral Curves of Monopoles

    International Nuclear Information System (INIS)

    Guilfoyle, Brendan; Khalid, Madeeha; Ramon Mari, Jose J.

    2010-01-01

    We study Lagrangian points on smooth holomorphic curves in TP 1 equipped with a natural neutral Kaehler structure, and prove that they must form real curves. By virtue of the identification of TP 1 with the space LE 3 of oriented affine lines in Euclidean 3-space, these Lagrangian curves give rise to ruled surfaces in E 3 , which we prove have zero Gauss curvature. Each ruled surface is shown to be the tangent lines to a curve in E 3 , called the edge of regression of the ruled surface. We give an alternative characterization of these curves as the points in E 3 where the number of oriented lines in the complex curve Σ that pass through the point is less than the degree of Σ. We then apply these results to the spectral curves of certain monopoles and construct the ruled surfaces and edges of regression generated by the Lagrangian curves.

  1. Lagrangian solution of supersonic real gas flows

    International Nuclear Information System (INIS)

    Loh, Chingyuen; Liou, Mengsing

    1993-01-01

    This paper details the procedure of the real gas Riemann solution in the Lagrangian approach originally proposed by Loh and Hui for perfect gases. The extension to real gases is nontrivial and requires substantial development of an exact real-gas Riemann solver for the Lagrangian form of conservation laws. The first-order Gudonov scheme is enhanced for accuracy by adding limited anti-diffusive terms according to Sweby. Extensive calculations were made to test the accuracy and robustness of the present real gas Lagrangian approach, including complex wave interactions of different types. The accuracy for capturing 2D oblique waves and slip line is clearly demonstrated. In addition, we also show the real gas effect in a generic engine nozzle

  2. Simplified chiral superfield propagators for chiral constant mass superfields

    International Nuclear Information System (INIS)

    Srivastava, P.P.

    1983-01-01

    Unconstrained superfield potentials are introduced to derive Feynman rules for chiral superfields following conventional procedure which is easy and instructive. Propagators for the case when the mass parameters are constant chiral superfields are derived. The propagators reported here are very simple compared to those available in literature and allow a manageable calculation of higher loops. (Author) [pt

  3. Learn the Lagrangian: A Vector-Valued RKHS Approach to Identifying Lagrangian Systems.

    Science.gov (United States)

    Cheng, Ching-An; Huang, Han-Pang

    2016-12-01

    We study the modeling of Lagrangian systems with multiple degrees of freedom. Based on system dynamics, canonical parametric models require ad hoc derivations and sometimes simplification for a computable solution; on the other hand, due to the lack of prior knowledge in the system's structure, modern nonparametric models in machine learning face the curse of dimensionality, especially in learning large systems. In this paper, we bridge this gap by unifying the theories of Lagrangian systems and vector-valued reproducing kernel Hilbert space. We reformulate Lagrangian systems with kernels that embed the governing Euler-Lagrange equation-the Lagrangian kernels-and show that these kernels span a subspace capturing the Lagrangian's projection as inverse dynamics. By such property, our model uses only inputs and outputs as in machine learning and inherits the structured form as in system dynamics, thereby removing the need for the mundane derivations for new systems as well as the generalization problem in learning from scratches. In effect, it learns the system's Lagrangian, a simpler task than directly learning the dynamics. To demonstrate, we applied the proposed kernel to identify the robot inverse dynamics in simulations and experiments. Our results present a competitive novel approach to identifying Lagrangian systems, despite using only inputs and outputs.

  4. Chiral nanophotonics chiral optical properties of plasmonic systems

    CERN Document Server

    Schäferling, Martin

    2017-01-01

    This book describes the physics behind the optical properties of plasmonic nanostructures focusing on chiral aspects. It explains in detail how the geometry determines chiral near-fields and how to tailor their shape and strength. Electromagnetic fields with strong optical chirality interact strongly with chiral molecules and, therefore, can be used for enhancing the sensitivity of chiroptical spectroscopy techniques. Besides a short review of the latest results in the field of plasmonically enhanced enantiomer discrimination, this book introduces the concept of chiral plasmonic near-field sources for enhanced chiroptical spectroscopy. The discussion of the fundamental properties of these light sources provides the theoretical basis for further optimizations and is of interest for researchers at the intersection of nano-optics, plasmonics and stereochemistry. .

  5. Electroweak Physics at the Tevatron and LHC: Theoretical Status and Perspectives

    OpenAIRE

    Baur, U.

    2005-01-01

    I review the status of theoretical calculations relevant for electroweak physics at the Tevatron and LHC and discuss future directions. I also give a brief overview of current electroweak data and discuss future expectations.

  6. Combined QCD and electroweak analysis of HERA data

    Energy Technology Data Exchange (ETDEWEB)

    Abramowicz, H. [Tel Aviv Univ. (Israel). School of Physics; Max-Planck-Institute for Physics, Munich (Germany); Abt, I. [Max-Planck-Institute for Physics, Munich (Germany); Adamczyk, L. [AGH-Univ. of Science and Technology, Krakow (Poland). Faculty of Physics and Applied Computer Science; Collaboration: ZEUS Collaboration; and others

    2016-03-15

    A simultaneous fit of parton distribution functions (PDFs) and electroweak parameters to HERA data on deep inelastic scattering is presented. The input data are the neutral current and charged current inclusive cross sections which were previously used in the QCD analysis leading to the HERAPDF2.0 PDFs. In addition, the polarisation of the electron beam was taken into account for the ZEUS data recorded between 2004 and 2007. Results on the vector and axial-vector couplings of the Z boson to u- and d-type quarks, on the value of the electroweak mixing angle and the mass of the W boson are presented. The values obtained for the electroweak parameters are in agreement with Standard Model predictions.

  7. Studying the Electroweak Sector with the ATLAS Detector

    CERN Document Server

    Bittrich, Carsten; The ATLAS collaboration

    2018-01-01

    The large integrated luminosities that are available at the LHC, allow to test the gauge structure of the electroweak sector of the Standard Model to highest precision. In this talk, we review the latest results of the ATLAS collaboration involving di-boson and multiboson final states as well as the corresponding limits on anomalous gauge couplings. Moreover, we discuss the electroweak production of vector boson at 13 TeV. Another approach to test the consistency of the electroweak sector is via precision measurements. ATLAS has recently published a measurement of the tau-polarization in Z events as well as a three dimensional cross-section measurement of the Drell-Yan process. The latter allows for the extraction of the forward-backward asymmetry that can be interpreted as a measurement of the weak mixing angle. Both results will be presented and discussed.

  8. Electroweak penguin diagrams and two-body B decays

    International Nuclear Information System (INIS)

    Gronau, M.; Hernandez, O.F.; London, D.; Rosner, J.L.

    1995-01-01

    We discuss the role of electroweak penguin diagrams in B decays to two light pseudoscalar mesons. We confirm that the extraction of the weak phase α through the isospin analysis involving B→ππ decays is largely unaffected by such operators. However, the methods proposed to obtain weak and strong phases by relating B→ππ, B→πK, and B→K bar K decays through flavor SU(3) will be invalidated if eletroweak penguin diagrams are large. We show that, although the introduction of electroweak penguin contributions introduces no new amplitudes of flavor SU(3), there are a number of ways to experimentally measure the size of such effects. Finally, using SU(3) amplitude relations we present a new way of measuring the weak angle γ which holds even in the presence of electroweak penguin diagrams

  9. Supersymmetric electro-weak effects on gsub(μ)-2

    International Nuclear Information System (INIS)

    Yuan, T.C.; Arnowitt, R.; Chamseddine, A.H.; Nath, P.

    1984-01-01

    A model independent analysis of the supersymmetric electroweak contribution to gsub(μ)-2 is discussed within the framework of N=1 Supergravity unified theory. A detailed comparison with existing experiment of two models (R.G. and T.B.) is carried out. The supersymmetric electro-weak contributions are found to be characteristically different and generally larger than the electro-weak contributions of the standard theory, and in many cases significantly larger. Effects of the hidden sector and the photino mass dependence of gsub(μ)-2 are also investigated. Present data already eliminates some choices of parameters. Reduction of existing experimental errors by a factor of 3 will make contact with most R.G. models and by a factor of 10 with most T.B. models. (orig.)

  10. The electroweak phase transition in minimal supergravity models

    CERN Document Server

    Nanopoulos, Dimitri V

    1994-01-01

    We have explored the electroweak phase transition in minimal supergravity models by extending previous analysis of the one-loop Higgs potential to include finite temperature effects. Minimal supergravity is characterized by two higgs doublets at the electroweak scale, gauge coupling unification, and universal soft-SUSY breaking at the unification scale. We have searched for the allowed parameter space that avoids washout of baryon number via unsuppressed anomalous Electroweak sphaleron processes after the phase transition. This requirement imposes strong constraints on the Higgs sector. With respect to weak scale baryogenesis, we find that the generic MSSM is {\\it not} phenomenologically acceptable, and show that the additional experimental and consistency constraints of minimal supergravity restricts the mass of the lightest CP-even Higgs even further to $m_h\\lsim 32\\GeV$ (at one loop), also in conflict with experiment. Thus, if supergravity is to allow for baryogenesis via any other mechanism above the weak...

  11. Combined QCD and electroweak analysis of HERA data

    International Nuclear Information System (INIS)

    Abramowicz, H.; Abt, I.; Adamczyk, L.

    2016-03-01

    A simultaneous fit of parton distribution functions (PDFs) and electroweak parameters to HERA data on deep inelastic scattering is presented. The input data are the neutral current and charged current inclusive cross sections which were previously used in the QCD analysis leading to the HERAPDF2.0 PDFs. In addition, the polarisation of the electron beam was taken into account for the ZEUS data recorded between 2004 and 2007. Results on the vector and axial-vector couplings of the Z boson to u- and d-type quarks, on the value of the electroweak mixing angle and the mass of the W boson are presented. The values obtained for the electroweak parameters are in agreement with Standard Model predictions.

  12. Combined QCD and electroweak analysis of HERA data

    CERN Document Server

    Abramowicz, H; Adamczyk, L; Adamus, M; Antonelli, S; Aushev, V; Behnke, O; Behrens, U; Bertolin, A; Bloch, I; Boos, EG; Brock, I; Brook, NH; Brugnera, R; Bruni, A; Bussey, PJ; Caldwell, A; Capua, M; Catterall, CD; Chwastowski, J; Ciborowski, J; Ciesielski, R; Cooper-Sarkar, AM; Corradi, M; Dementiev, RK; Devenish, RCE; Dusini, S; Foster, B; Gach, G; Gallo, E; Garfagnini, A; Geiser, A; Gizhko, A; Gladilin, LK; Golubkov, Yu A; Grzelak, G; Guzik, M; Hain, W; Hochman, D; Hori, R; Ibrahim, ZA; Iga, Y; Ishitsuka, M; Januschek, F; Jomhari, NZ; Kadenko, I; Kananov, S; Karshon, U; Kaur, P; Kisielewska, D; Klanner, R; Klein, U; Korzhavina, IA; Kotański, A; Kötz, U; Kovalchuk, N; Kowalski, H; Krupa, B; Kuprash, O; Kuze, M; Levchenko, BB; Levy, A; Limentani, S; Lisovyi, M; Lobodzinska, E; Löhr, B; Lohrmann, E; Longhin, A; Lontkovskyi, D; Lukina, OYu; Makarenko, I; Malka, J; Mohamad Idris, F; Mohammad Nasir, N; Myronenko, V; Nagano, K; Nobe, T; Nowak, RJ; Onishchuk, Yu; Paul, E; Perlański, W; Pokrovskiy, NS; Przybycien, M; Roloff, P; Ruspa, M; Saxon, DH; Schioppa, M; Schneekloth, U; Schörner-Sadenius, T; Shcheglova, LM; Shevchenko, R; Shkola, O; Shyrma, Yu; Singh, I; Skillicorn, IO; Słomiński, W; Solano, A; Stanco, L; Stefaniuk, N; Stern, A; Stopa, P; Sztuk-Dambietz, J; Tassi, E; Tokushuku, K; Tomaszewska, J; Tsurugai, T; Turcato, M; Turkot, O; Tymieniecka, T; Verbytskyi, A; Wan Abdullah, WAT; Wichmann, K; Wing, M; Yamada, S; Yamazaki, Y; Zakharchuk, N; Żarnecki, AF; Zawiejski, L; Zenaiev, O; Zhautykov, BO; Zotkin, DS; Bhadra, S; Gwenlan, C; Hlushchenko, O; Polini, A; Mastroberardino, A

    2016-05-03

    A simultaneous fit of parton distribution functions (PDFs) and electroweak parameters to HERA data on deep inelastic scattering is presented. The input data are the neutral current and charged current inclusive cross sections which were previously used in the QCD analysis leading to the HERAPDF2.0 PDFs. In addition, the polarisation of the electron beam was taken into account for the ZEUS data recorded between 2004 and 2007. Results on the vector and axial-vector couplings of the Z boson to u- and d-type quarks, on the value of the electroweak mixing angle and the mass of the W boson are presented. The values obtained for the electroweak parameters are in agreement with Standard Model predictions.

  13. Strong Electroweak Symmetry Breaking and Spin-0 Resonances

    International Nuclear Information System (INIS)

    Evans, Jared; Luty, Markus A.

    2009-01-01

    We argue that theories of the strong electroweak symmetry breaking sector necessarily contain new spin 0 states at the TeV scale in the tt and tb/bt channels, even if the third generation quarks are not composite at the TeV scale. These states couple sufficiently strongly to third generation quarks to have significant production at LHC via gg→φ 0 or gb→tφ - . The existence of narrow resonances in QCD suggests that the strong electroweak breaking sector contains narrow resonances that decay to tt or tb/bt, with potentially significant branching fractions to 3 or more longitudinal W and Z bosons. These may give new 'smoking gun' signals of strong electroweak symmetry breaking.

  14. The Mather problem for lower semicontinuous Lagrangians

    KAUST Repository

    Gomes, Diogo A.; Terrone, Gabriele

    2013-01-01

    In this paper we develop the Aubry-Mather theory for Lagrangians in which the potential energy can be discontinuous. Namely we assume that the Lagrangian is lower semicontinuous in the state variable, piecewise smooth with a (smooth) discontinuity surface, as well as coercive and convex in the velocity. We establish existence of Mather measures, various approximation results, partial regularity of viscosity solutions away from the singularity, invariance by the Euler-Lagrange flow away from the singular set, and further jump conditions that correspond to conservation of energy and tangential momentum across the discontinuity. © 2013 Springer Basel.

  15. The Mather problem for lower semicontinuous Lagrangians

    KAUST Repository

    Gomes, Diogo A.

    2013-08-01

    In this paper we develop the Aubry-Mather theory for Lagrangians in which the potential energy can be discontinuous. Namely we assume that the Lagrangian is lower semicontinuous in the state variable, piecewise smooth with a (smooth) discontinuity surface, as well as coercive and convex in the velocity. We establish existence of Mather measures, various approximation results, partial regularity of viscosity solutions away from the singularity, invariance by the Euler-Lagrange flow away from the singular set, and further jump conditions that correspond to conservation of energy and tangential momentum across the discontinuity. © 2013 Springer Basel.

  16. Lagrangian solution of supersonic real gas flows

    Science.gov (United States)

    Loh, Ching-Yuen; Liou, Meng-Sing

    1993-01-01

    The present extention of a Lagrangian approach of the Riemann solution procedure, which was originally proposed for perfect gases, to real gases, is nontrivial and requires the development of an exact real-gas Riemann solver for the Lagrangian form of the conservation laws. Calculations including complex wave interactions of various types were conducted to test the accuracy and robustness of the approach. Attention is given to the case of 2D oblique waves' capture, where a slip line is clearly in evidence; the real gas effect is demonstrated in the case of a generic engine nozzle.

  17. A chiral quark model of the nucleon

    International Nuclear Information System (INIS)

    Wakamatsu, M.; Yoshiki, H.

    1991-01-01

    The baryon-number-one extended solution of a chiral quark lagrangian is obtained in the stationary-phase approximation with full inclusion of the sea-quark degrees of freedom. The collective quantization method is then applied to this static solution to obtain the nucleon (and Δ) state with the definite spin and isospin. A fundamental quantity appearing in this quantization procedure is the moment of inertia of the soliton system. We evaluate this quantity without recourse to the derivative expansion, by performing the necessary double sum over all the positive- and negative-energy quark orbitals in the mean field potential. Closed formulas are-derived for the nucleon (and Δ) matrix elements of arbitrary quark bilinear operators. These formulas are then used for calculating various nucleon observables in a nonperturbative manner with inclusion of the sea-quark effects. An especially interesting observable is the spin expectation value of the proton related to the recent EMC experiment. We derive the proton spin sum rule, and then explicitly evaluate the detailed contents of this sum rule. The proton spin analysis is shown to be particularly useful for clarifying the underlying dynamical content of the Skyrme model at quark level, thereby providing us with valuable information about its utility and limitation. (orig.)

  18. Chiral Cliffs: Investigating the Influence of Chirality on Binding Affinity.

    Science.gov (United States)

    Schneider, Nadine; Lewis, Richard A; Fechner, Nikolas; Ertl, Peter

    2018-05-11

    Chirality is understood by many as a binary concept: a molecule is either chiral or it is not. In terms of the action of a structure on polarized light, this is indeed true. When examined through the prism of molecular recognition, the answer becomes more nuanced. In this work, we investigated chiral behavior on protein-ligand binding: when does chirality make a difference in binding activity? Chirality is a property of the 3D structure, so recognition also requires an appreciation of the conformation. In many situations, the bioactive conformation is undefined. We set out to address this by defining and using several novel 2D descriptors to capture general characteristic features of the chiral center. Using machine-learning methods, we built different predictive models to estimate if a chiral pair (a set of two enantiomers) might exhibit a chiral cliff in a binding assay. A set of about 3800 chiral pairs extracted from the ChEMBL23 database was used to train and test our models. By achieving an accuracy of up to 75 %, our models provide good performance in discriminating chiral cliffs from non-cliffs. More importantly, we were able to derive some simple guidelines for when one can reasonably use a racemate and when an enantiopure compound is needed in an assay. We critically discuss our results and show detailed examples of using our guidelines. Along with this publication we provide our dataset, our novel descriptors, and the Python code to rebuild the predictive models. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Towards a nonequilibrium quantum field theory approach to electroweak baryogenesis

    International Nuclear Information System (INIS)

    Riotto, A.

    1996-01-01

    We propose a general method to compute CP violating observables from extensions of the standard model in the context of electroweak baryogenesis. It is an alternative to the one recently developed by Huet and Nelson and relies on a nonequilibrium quantum field theory approach. The method is valid for all shapes and sizes of the bubble wall expanding in the thermal bath during a first-order electroweak phase transition. The quantum physics of CP violation and its suppression coming from the incoherent nature of thermal processes are also made explicit. copyright 1996 The American Physical Society

  20. On stability of the electroweak vacuum and the Higgs portal

    International Nuclear Information System (INIS)

    Lebedev, Oleg

    2012-03-01

    In the Standard Model (SM), the Higgs mass around 125 GeV implies that the electroweak vacuum is metastable since the quartic Higgs coupling turns negative at high energies. I point out that an arbitrarily small mixing of the Higgs with a heavy singlet can make the electroweak vacuum completely stable. This is due to a tree level correction to the Higgs mass, which survives in the zero--mixing/heavy--singlet limit. Such a situation is experimentally indistinguishable from the SM, unless the Higgs self--coupling can be measured. As a result, Higgs inflation and its variants can still be viable.

  1. Production of electroweak bosons at hadron colliders: theoretical aspects

    CERN Document Server

    Mangano, Michelangelo L.

    2016-01-01

    Since the W and Z discovery, hadron colliders have provided a fertile ground, in which continuously improving measurements and theoretical predictions allow to precisely determine the gauge boson properties, and to probe the dynamics of electroweak and strong interactions. This article will review, from a theoretical perspective, the role played by the study, at hadron colliders, of electroweak boson production properties, from the better understanding of the proton structure, to the discovery and studies of the top quark and of the Higgs, to the searches for new phenomena beyond the Standard Model.

  2. On stability of the electroweak vacuum and the Higgs portal

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, Oleg

    2012-03-15

    In the Standard Model (SM), the Higgs mass around 125 GeV implies that the electroweak vacuum is metastable since the quartic Higgs coupling turns negative at high energies. I point out that an arbitrarily small mixing of the Higgs with a heavy singlet can make the electroweak vacuum completely stable. This is due to a tree level correction to the Higgs mass, which survives in the zero--mixing/heavy--singlet limit. Such a situation is experimentally indistinguishable from the SM, unless the Higgs self--coupling can be measured. As a result, Higgs inflation and its variants can still be viable.

  3. Towards Reviving Electroweak Baryogenesis with a Fourth Generation

    Directory of Open Access Journals (Sweden)

    Wei-Shu Hou

    2013-01-01

    universe. However, it does not work within the standard model due to two reasons: (1 the strength of CP violation from the Kobayashi-Maskawa mechanism with three generations is too small; (2 the electroweak phase transition is not first order for the experimentally allowed Higgs boson mass. We discuss possibilities to solve these problems by introducing a fourth generation of fermions and how electroweak baryogenesis might be revived. We also discuss briefly the recent observation of a Higgs-like boson with mass around 125 GeV, which puts the fourth generation in a difficult situation, and the possible way out.

  4. Hadronic electroweak processes in a finite volume

    International Nuclear Information System (INIS)

    Agadjanov, Andria

    2017-01-01

    In the present thesis, we study a number of hadronic electroweak processes in a finite volume. Our work is motivated by the ongoing and future lattice simulations of the strong interaction theory called quantum chromodynamics. According to the available computational resources, the numerical calculations are necessarily performed on lattices with a finite spatial extension. The first part of the thesis is based on the finite volume formalism which is a standard method to investigate the processes with the final state interactions, and in particular, the elastic hadron resonances, on the lattice. Throughout the work, we systematically apply the non-relativistic effective field theory. The great merit of this approach is that it encodes the low-energy dynamics directly in terms of the effective range expansion parameters. After a brief introduction into the subject, we formulate a framework for the extraction of the ΔNγ * as well as the B→K * transition form factors from lattice data. Both processes are of substantial phenomenological interest, including the search for physics beyond the Standard Model. Moreover, we provide a proper field-theoretical definition of the resonance matrix elements, and advocate it in comparison to the one based on the infinitely narrow width approximation. In the second part we consider certain aspects of the doubly virtual nucleon Compton scattering. The main objective of the work is to answer the question whether there is, in the Regge language, a so-called fixed pole in the process. To answer this question, the unknown subtraction function, which enters one of the dispersion relations for the invariant amplitudes, has to be determined. The external field method provides a feasible approach to tackle this problem on the lattice. Considering the nucleon in a periodic magnetic field, we derive a simple relation for the ground state energy shift up to a second order in the field strength. The obtained result encodes the value of the

  5. Hadronic electroweak processes in a finite volume

    Energy Technology Data Exchange (ETDEWEB)

    Agadjanov, Andria

    2017-11-07

    In the present thesis, we study a number of hadronic electroweak processes in a finite volume. Our work is motivated by the ongoing and future lattice simulations of the strong interaction theory called quantum chromodynamics. According to the available computational resources, the numerical calculations are necessarily performed on lattices with a finite spatial extension. The first part of the thesis is based on the finite volume formalism which is a standard method to investigate the processes with the final state interactions, and in particular, the elastic hadron resonances, on the lattice. Throughout the work, we systematically apply the non-relativistic effective field theory. The great merit of this approach is that it encodes the low-energy dynamics directly in terms of the effective range expansion parameters. After a brief introduction into the subject, we formulate a framework for the extraction of the ΔNγ{sup *} as well as the B→K{sup *} transition form factors from lattice data. Both processes are of substantial phenomenological interest, including the search for physics beyond the Standard Model. Moreover, we provide a proper field-theoretical definition of the resonance matrix elements, and advocate it in comparison to the one based on the infinitely narrow width approximation. In the second part we consider certain aspects of the doubly virtual nucleon Compton scattering. The main objective of the work is to answer the question whether there is, in the Regge language, a so-called fixed pole in the process. To answer this question, the unknown subtraction function, which enters one of the dispersion relations for the invariant amplitudes, has to be determined. The external field method provides a feasible approach to tackle this problem on the lattice. Considering the nucleon in a periodic magnetic field, we derive a simple relation for the ground state energy shift up to a second order in the field strength. The obtained result encodes the

  6. Two-chiral component microemulsion EKC - chiral surfactant and chiral oil. Part 2: diethyl tartrate.

    Science.gov (United States)

    Kahle, Kimberly A; Foley, Joe P

    2007-08-01

    In this second study on dual-chirality microemulsions containing a chiral surfactant and a chiral oil, a less hydrophobic and lower interfacial tension chiral oil, diethyl tartrate, is employed (Part 1, Foley, J. P. et al.., Electrophoresis, DOI: 10.1002/elps.200600551). Six stereochemical combinations of dodecoxycarbonylvaline (DDCV: R, S, or racemic, 2.00% w/v), racemic 2-hexanol (1.65% v/v), and diethyl tartrate (D, L, or racemic, 0.88% v/v) were examined as pseudostationary phases (PSPs) for the enantioseparation of six chiral pharmaceutical compounds: pseudoephedrine, ephedrine, N-methyl ephedrine, metoprolol, synephrine, and atenolol. Average efficiencies increased with the addition of a chiral oil to R-DDCV PSP formulations. Modest improvements in resolution and enantioselectivity (alpha(enant)) were achieved with two-chiral-component systems over the one-chiral-component microemulsion. Slight enantioselective synergies were confirmed using a thermodynamic model. Results obtained in this study are compared to those obtained in Part 1 as well as those obtained with chiral MEEKC using an achiral, low-interfacial-tension oil (ethyl acetate). Dual-chirality microemulsions with the more hydrophobic oil dibutyl tartrate yielded, relative to diethyl tartrate, higher efficiencies (100,000-134,000 vs. 80,800-94,300), but lower resolution (1.64-1.91 vs. 2.08-2.21) due to lower enantioselectivities (1.060-1.067 vs. 1.078-1.081). Atenolol enantiomers could not be separated with the dibutyl tartrate-based microemulsions but were partially resolved using diethyl tartrate microemulsions. A comparable single-chirality microemulsion based on the achiral oil ethyl acetate yielded, relative to diethyl tartrate, lower efficiency (78 300 vs. 91 600), higher resolution (1.99 vs. 1.83), and similar enantioselectivities.

  7. Experimental investigation of Lagrangian structure functions in turbulence

    DEFF Research Database (Denmark)

    Berg, Jacob; Ott, Søren; Mann, Jakob

    2009-01-01

    Lagrangian properties obtained from a particle tracking velocimetry experiment in a turbulent flow at intermediate Reynolds number are presented. Accurate sampling of particle trajectories is essential in order to obtain the Lagrangian structure functions and to measure intermittency at small...

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

    International Nuclear Information System (INIS)

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

    2001-05-01

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

  9. Flatspace chiral supergravity

    Science.gov (United States)

    Bagchi, Arjun; Basu, Rudranil; Detournary, Stéphane; Parekh, Pulastya

    2018-05-01

    We propose a holographic duality between a 2 dimensional (2d) chiral superconformal field theory and a certain theory of supergravity in 3d with flatspace boundary conditions that is obtained as a double scaling limit of a parity breaking theory of supergravity. We show how the asymptotic symmetries of the bulk theory reduce from the "despotic" super Bondi-Metzner-Sachs algebra (or equivalently the inhomogeneous super Galilean conformal algebra) to a single copy of the super-Virasoro algebra in this limit and also reproduce the same reduction from a study of null vectors in the putative 2d dual field theory.

  10. Chiral Nuclear Dynamics II

    CERN Document Server

    Rho, Mannque

    2008-01-01

    This is the sequel to the first volume to treat in one effective field theory framework the physics of strongly interacting matter under extreme conditions. This is vital for understanding the high temperature phenomena taking place in relativistic heavy ion collisions and in the early Universe, as well as the high-density matter predicted to be present in compact stars. The underlying thesis is that what governs hadronic properties in a heat bath and/or a dense medium is hidden local symmetry which emerges from chiral dynamics of light quark systems and from the duality between QCD in 4D and

  11. Target Lagrangian kinematic simulation for particle-laden flows.

    Science.gov (United States)

    Murray, S; Lightstone, M F; Tullis, S

    2016-09-01

    The target Lagrangian kinematic simulation method was motivated as a stochastic Lagrangian particle model that better synthesizes turbulence structure, relative to stochastic separated flow models. By this method, the trajectories of particles are constructed according to synthetic turbulent-like fields, which conform to a target Lagrangian integral timescale. In addition to recovering the expected Lagrangian properties of fluid tracers, this method is shown to reproduce the crossing trajectories and continuity effects, in agreement with an experimental benchmark.

  12. Three-dimensional free Lagrangian hydrodynamics

    International Nuclear Information System (INIS)

    Trease, H.E.

    1985-01-01

    The purpose of the discussion is to describe the development of a 3-D free Lagrangian hyrodynamics algorithm. The 3-D algorithm is an outgrowth of an earlier 2-D free Lagrange model. Only the more pertinent issues of the free Lagrange algorithm are presented. A complete production code is being developed to support the free Lagrange algorithm described. 4 refs

  13. Effective Lagrangian density in gauge supersymmetry

    International Nuclear Information System (INIS)

    Chang, S.S.

    1976-01-01

    In the framework of gauge supersymmetry proposed by Arnowitt and Nath, an effective Lagrangian density is formally rewritten in terms of a spontaneously broken vacuum metric and the remaining perturbative part in the gauge metric tensor. Tensor notations in the superspace are revised so that all sign factors of Grassmann parities appear more systematically

  14. Lagrangian approach in spin-oscillations problem

    Directory of Open Access Journals (Sweden)

    P.V. Pyshkin

    2014-12-01

    Full Text Available Lagrangian of electronic liquid in magneto-inhomogeneous micro-conductor has been constructed. A corresponding Euler-Lagrange equation has been solved. It was shown that the described system has eigenmodes of spin polarization and total electric current oscillations. The suggested approach permits to study the spin dynamics in an open-circuit which contains capacitance and/or inductivity.

  15. Lagrangian ocean analysis: Fundamentals and practices

    Science.gov (United States)

    van Sebille, Erik; Griffies, Stephen M.; Abernathey, Ryan; Adams, Thomas P.; Berloff, Pavel; Biastoch, Arne; Blanke, Bruno; Chassignet, Eric P.; Cheng, Yu; Cotter, Colin J.; Deleersnijder, Eric; Döös, Kristofer; Drake, Henri F.; Drijfhout, Sybren; Gary, Stefan F.; Heemink, Arnold W.; Kjellsson, Joakim; Koszalka, Inga Monika; Lange, Michael; Lique, Camille; MacGilchrist, Graeme A.; Marsh, Robert; Mayorga Adame, C. Gabriela; McAdam, Ronan; Nencioli, Francesco; Paris, Claire B.; Piggott, Matthew D.; Polton, Jeff A.; Rühs, Siren; Shah, Syed H. A. M.; Thomas, Matthew D.; Wang, Jinbo; Wolfram, Phillip J.; Zanna, Laure; Zika, Jan D.

    2018-01-01

    Lagrangian analysis is a powerful way to analyse the output of ocean circulation models and other ocean velocity data such as from altimetry. In the Lagrangian approach, large sets of virtual particles are integrated within the three-dimensional, time-evolving velocity fields. Over several decades, a variety of tools and methods for this purpose have emerged. Here, we review the state of the art in the field of Lagrangian analysis of ocean velocity data, starting from a fundamental kinematic framework and with a focus on large-scale open ocean applications. Beyond the use of explicit velocity fields, we consider the influence of unresolved physics and dynamics on particle trajectories. We comprehensively list and discuss the tools currently available for tracking virtual particles. We then showcase some of the innovative applications of trajectory data, and conclude with some open questions and an outlook. The overall goal of this review paper is to reconcile some of the different techniques and methods in Lagrangian ocean analysis, while recognising the rich diversity of codes that have and continue to emerge, and the challenges of the coming age of petascale computing.

  16. Equivalence of Lagrangian and Hamiltonian BRST quantizations

    International Nuclear Information System (INIS)

    Grigoryan, G.V.; Grigoryan, R.P.; Tyutin, I.V.

    1992-01-01

    Two approaches to the quantization of gauge theories using BRST symmetry are widely used nowadays: the Lagrangian quantization, developed in (BV-quantization) and Hamiltonian quantization, formulated in (BFV-quantization). For all known examples of field theory (Yang-Mills theory, gravitation etc.) both schemes give equivalent results. However the equivalence of these approaches in general wasn't proved. The main obstacle in comparing of these formulations consists in the fact, that in Hamiltonian approach the number of ghost fields is equal to the number of all first-class constraints, while in the Lagrangian approach the number of ghosts is equal to the number of independent gauge symmetries, which is equal to the number of primary first-class constraints only. This paper is devoted to the proof of the equivalence of Lagrangian and Hamiltonian quantizations for the systems with first-class constraints only. This is achieved by a choice of special gauge in the Hamiltonian approach. It's shown, that after integration over redundant variables on the functional integral we come to effective action which is constructed according to rules for construction of the effective action in Lagrangian quantization scheme

  17. QUANTIZATION OF NON-LAGRANGIAN SYSTEMS

    Czech Academy of Sciences Publication Activity Database

    Kochan, Denis

    2009-01-01

    Roč. 24, 28-29 (2009), s. 5319-5340 ISSN 0217-751X R&D Projects: GA MŠk(CZ) LC06002 Institutional research plan: CEZ:AV0Z10480505 Keywords : dissipative quantization * non-Lagrangian system * umbilical string Subject RIV: BE - Theoretical Physics Impact factor: 0.941, year: 2009

  18. Lagrangian statistics in compressible isotropic homogeneous turbulence

    Science.gov (United States)

    Yang, Yantao; Wang, Jianchun; Shi, Yipeng; Chen, Shiyi

    2011-11-01

    In this work we conducted the Direct Numerical Simulation (DNS) of a forced compressible isotropic homogeneous turbulence and investigated the flow statistics from the Lagrangian point of view, namely the statistics is computed following the passive tracers trajectories. The numerical method combined the Eulerian field solver which was developed by Wang et al. (2010, J. Comp. Phys., 229, 5257-5279), and a Lagrangian module for tracking the tracers and recording the data. The Lagrangian probability density functions (p.d.f.'s) have then been calculated for both kinetic and thermodynamic quantities. In order to isolate the shearing part from the compressing part of the flow, we employed the Helmholtz decomposition to decompose the flow field (mainly the velocity field) into the solenoidal and compressive parts. The solenoidal part was compared with the incompressible case, while the compressibility effect showed up in the compressive part. The Lagrangian structure functions and cross-correlation between various quantities will also be discussed. This work was supported in part by the China's Turbulence Program under Grant No.2009CB724101.

  19. Gravitational theory with the local quadratic Lagrangian

    International Nuclear Information System (INIS)

    Tentyukov, M.N.

    1992-01-01

    It is suggested that the vacuum gravitational equations should be derived from the local Lagrangian containing only first-order derivatives. As an example we demonstrate the properties of the derived equations by studying of the exact spherically-symmetric solutions. 23 refs

  20. Effective lagrangian from bosonic string field theory

    International Nuclear Information System (INIS)

    Nakazawa, Naohito

    1987-01-01

    We investigate the low-energy effective action from the string field theoretical view point. The low-energy effective lagrangian for the massless mode of bosonic string is determined to the order of α'. We find a term which can not be determined from the S-matrix approach. (author)

  1. Chaotic Lagrangian models for turbulent relative dispersion.

    Science.gov (United States)

    Lacorata, Guglielmo; Vulpiani, Angelo

    2017-04-01

    A deterministic multiscale dynamical system is introduced and discussed as a prototype model for relative dispersion in stationary, homogeneous, and isotropic turbulence. Unlike stochastic diffusion models, here trajectory transport and mixing properties are entirely controlled by Lagrangian chaos. The anomalous "sweeping effect," a known drawback common to kinematic simulations, is removed through the use of quasi-Lagrangian coordinates. Lagrangian dispersion statistics of the model are accurately analyzed by computing the finite-scale Lyapunov exponent (FSLE), which is the optimal measure of the scaling properties of dispersion. FSLE scaling exponents provide a severe test to decide whether model simulations are in agreement with theoretical expectations and/or observation. The results of our numerical experiments cover a wide range of "Reynolds numbers" and show that chaotic deterministic flows can be very efficient, and numerically low-cost, models of turbulent trajectories in stationary, homogeneous, and isotropic conditions. The mathematics of the model is relatively simple, and, in a geophysical context, potential applications may regard small-scale parametrization issues in general circulation models, mixed layer, and/or boundary layer turbulence models as well as Lagrangian predictability studies.

  2. Relating Lagrangian and Hamiltonian Formalisms of LC Circuits

    NARCIS (Netherlands)

    Clemente-Gallardo, Jesús; Scherpen, Jacquelien M.A.

    2003-01-01

    The Lagrangian formalism earlier defined for (switching) electrical circuits, is adapted to the Lagrangian formalism defined on Lie algebroids. This allows us to define regular Lagrangians and consequently, well-defined Hamiltonian descriptions of arbitrary LC networks. The relation with other

  3. "Lagrangian" for a Non-Lagrangian Field Theory with N=2 Supersymmetry.

    Science.gov (United States)

    Gadde, Abhijit; Razamat, Shlomo S; Willett, Brian

    2015-10-23

    We suggest that at least some of the strongly coupled N=2 quantum field theories in 4D can have a nonconformal N=1 Lagrangian description flowing to them at low energies. In particular, we construct such a description for the N=2 rank one superconformal field theory with E(6) flavor symmetry, for which a Lagrangian description was previously unavailable. We utilize this description to compute several supersymmetric partition functions.

  4. Nanoscale chirality in metal and semiconductor nanoparticles.

    Science.gov (United States)

    Kumar, Jatish; Thomas, K George; Liz-Marzán, Luis M

    2016-10-18

    The field of chirality has recently seen a rejuvenation due to the observation of chirality in inorganic nanomaterials. The advancements in understanding the origin of nanoscale chirality and the potential applications of chiroptical nanomaterials in the areas of optics, catalysis and biosensing, among others, have opened up new avenues toward new concepts and design of novel materials. In this article, we review the concept of nanoscale chirality in metal nanoclusters and semiconductor quantum dots, then focus on recent experimental and theoretical advances in chiral metal nanoparticles and plasmonic chirality. Selected examples of potential applications and an outlook on the research on chiral nanomaterials are additionally provided.

  5. Chiral quantum optics.

    Science.gov (United States)

    Lodahl, Peter; Mahmoodian, Sahand; Stobbe, Søren; Rauschenbeutel, Arno; Schneeweiss, Philipp; Volz, Jürgen; Pichler, Hannes; Zoller, Peter

    2017-01-25

    Advanced photonic nanostructures are currently revolutionizing the optics and photonics that underpin applications ranging from light technology to quantum-information processing. The strong light confinement in these structures can lock the local polarization of the light to its propagation direction, leading to propagation-direction-dependent emission, scattering and absorption of photons by quantum emitters. The possibility of such a propagation-direction-dependent, or chiral, light-matter interaction is not accounted for in standard quantum optics and its recent discovery brought about the research field of chiral quantum optics. The latter offers fundamentally new functionalities and applications: it enables the assembly of non-reciprocal single-photon devices that can be operated in a quantum superposition of two or more of their operational states and the realization of deterministic spin-photon interfaces. Moreover, engineered directional photonic reservoirs could lead to the development of complex quantum networks that, for example, could simulate novel classes of quantum many-body systems.

  6. Natural cold baryogenesis from strongly interacting electroweak symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Konstandin, Thomas; Servant, Géraldine, E-mail: tkonstan@cern.ch, E-mail: geraldine.servant@cern.ch [CERN Physics Department, Theory Division, CH-1211 Geneva 23 (Switzerland)

    2011-07-01

    The mechanism of ''cold electroweak baryogenesis'' has been so far unpopular because its proposal has relied on the ad-hoc assumption of a period of hybrid inflation at the electroweak scale with the Higgs acting as the waterfall field. We argue here that cold baryogenesis can be naturally realized without the need to introduce any slow-roll potential. Our point is that composite Higgs models where electroweak symmetry breaking arises via a strongly first-order phase transition provide a well-motivated framework for cold baryogenesis. In this case, reheating proceeds by bubble collisions and we argue that this can induce changes in Chern-Simons number, which in the presence of new sources of CP violation commonly lead to baryogenesis. We illustrate this mechanism using as a source of CP violation an effective dimension-six operator which is free from EDM constraints, another advantage of cold baryogenesis compared to the standard theory of electroweak baryogenesis. Our results are general as they do not rely on any particular UV completion but only on a stage of supercooling ended by a first-order phase transition in the evolution of the universe, which can be natural if there is nearly conformal dynamics at the TeV scale. Besides, baryon-number violation originates from the Standard Model only.

  7. Natural Cold Baryogenesis from Strongly Interacting Electroweak Symmetry Breaking

    CERN Document Server

    Konstandin, Thomas

    2011-01-01

    The mechanism of "cold electroweak baryogenesis" has been so far unpopular because its proposal has relied on the ad-hoc assumption of a period of hybrid inflation at the electroweak scale with the Higgs acting as the waterfall field. We argue here that cold baryogenesis can be naturally realized without the need to introduce any slow-roll potential. Our point is that composite Higgs models where electroweak symmetry breaking arises via a strongly first-order phase transition provide a well-motivated framework for cold baryogenesis. In this case, reheating proceeds by bubble collisions and we argue that this can induce changes in Chern-Simons number, which in the presence of new sources of CP violation commonly lead to baryogenesis. We illustrate this mechanism using as a source of CP violation an effective dimension-six operator which is free from EDM constraints, another advantage of cold baryogenesis compared to the standard theory of electroweak baryogenesis. Our results are general as they do not rely on...

  8. Natural cold baryogenesis from strongly interacting electroweak symmetry breaking

    International Nuclear Information System (INIS)

    Konstandin, Thomas; Servant, Géraldine

    2011-01-01

    The mechanism of ''cold electroweak baryogenesis'' has been so far unpopular because its proposal has relied on the ad-hoc assumption of a period of hybrid inflation at the electroweak scale with the Higgs acting as the waterfall field. We argue here that cold baryogenesis can be naturally realized without the need to introduce any slow-roll potential. Our point is that composite Higgs models where electroweak symmetry breaking arises via a strongly first-order phase transition provide a well-motivated framework for cold baryogenesis. In this case, reheating proceeds by bubble collisions and we argue that this can induce changes in Chern-Simons number, which in the presence of new sources of CP violation commonly lead to baryogenesis. We illustrate this mechanism using as a source of CP violation an effective dimension-six operator which is free from EDM constraints, another advantage of cold baryogenesis compared to the standard theory of electroweak baryogenesis. Our results are general as they do not rely on any particular UV completion but only on a stage of supercooling ended by a first-order phase transition in the evolution of the universe, which can be natural if there is nearly conformal dynamics at the TeV scale. Besides, baryon-number violation originates from the Standard Model only

  9. Significant Enhancement of Neutralino Dark Matter Annihilation from Electroweak Bremsstrahlung

    NARCIS (Netherlands)

    Bringmann, T.; Calore, F.

    2014-01-01

    ndirect searches for the cosmological dark matter have become ever more competitive during the past years. Here, we report the first full calculation of leading electroweak corrections to the annihilation rate of supersymmetric neutralino dark matter. We find that these corrections can be huge,

  10. Precision electroweak heavy flavor results from LEP and SLC

    International Nuclear Information System (INIS)

    Brown, D.

    1993-11-01

    The traditional Electroweak measurements made at Z factories using undifferentiated hadronic and leptonic Z decays will soon be reaching their asymptotic limits in precision. Consequently, much attention has recently been focused on extracting electroweak parameters from hadronic decays differentiated through heavy flavor tagging. This paper gives an overview of the various techniques used at LEP and SLC to tag heavy flavors. The measurements of the forward backward asymmetries and the partial widths for Z→b anti b and Z→c anti c decays are briefly described. The most recent results for these are presented, and are interpreted within the framework of the Standard Model. The precision of the electroweak parameters extracted from these measurements is shown to be comparable to that from other techniques. Assembling all the LEP electroweak data, constraints on the top and Higgs masses are found. The heavy flavor results, and in particular the new, very accurate Z→b anti b partial width measurements, are shown to play a key role in these limits. (orig.)

  11. Measurements of Z0 Electroweak Couplings at SLD

    International Nuclear Information System (INIS)

    Mancinelli, Giampero

    1999-01-01

    In this paper we report a summary of the results of several electroweak measurements performed by the SLD experiment at the Stanford Linear Collider (SLC). Most of these results are preliminary and are based, unless otherwise indicated, on the full 1993-1998 dataset of 560,000 hadronic Z 0 decays, produced with an average electron beam polarization of 73%

  12. Electroweak Higgs plus three jet production at NLO QCD

    International Nuclear Information System (INIS)

    Campanario, Francisco; Figy, Terrance M.; Plaetzer, Simon; Sjoedahl, Malin

    2013-11-01

    We calculate next-to-leading order (NLO) QCD corrections to electroweak Higgs plus three jet production. Both vector boson fusion (VBF) and Higgs-strahlung type contributions are included along with all interferences. The calculation is implemented within the Matchbox NLO framework of the Herwig++ event generator.

  13. Electroweak symmetry breaking in supersymmetric gauge-Higgs unification models

    International Nuclear Information System (INIS)

    Choi, Kiwoon; Jeong, Kwang-Sik; Okumura, Ken-ichi; Haba, Naoyuki; Shimizu, Yasuhiro; Yamaguchi, Masahiro

    2004-01-01

    We examine the Higgs mass parameters and electroweak symmetry breaking in supersymmetric orbifold field theories in which the 4-dimensional Higgs fields originate from higher-dimensional gauge supermultiplets. It is noted that such gauge-Higgs unification leads to a specific boundary condition on the Higgs mass parameters at the compactification scale, which is independent of the details of supersymmetry breaking mechanism. With this boundary condition, phenomenologically viable parameter space of the model is severely constrained by the condition of electroweak symmetry breaking for supersymmetry breaking scenarios which can be realized naturally in orbifold field theories. For instance, if it is assumed that the 4-dimensional effective theory is the minimal supersymmetric standard model with supersymmetry breaking parameters induced by the Scherk-Schwarz mechanism, a correct electroweak symmetry breaking can not be achieved for reasonable range of parameters of the model, even when one includes additional contributions to the Higgs mass parameters from the auxiliary component of 4-dimensional conformal compensator. However if there exists a supersymmetry breaking mediated by brane superfields, sizable portion of the parameter space can give a correct electroweak symmetry breaking. (author)

  14. Quantum chromodynamics effects in electroweak and Higgs physics

    Indian Academy of Sciences (India)

    Several examples of the often intricate effects of higher-order quantum chromodynamics (QCD) corrections on predictions for hadron-collider observables, are discussed, using the production of electroweak gauge boson and the Standard Model Higgs boson as examples. Particular attention is given to the interplay of QCD ...

  15. Measurement of Electroweak Top Quark Production at {D\\O}

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Yun-Tse [Univ. of Rochester, NY (United States)

    2013-01-01

    We present a new model-independent measurement of the electroweak single top-quark production cross section in proton-antiproton (p- $\\bar{p}$) collisions at √s = 1.96 TeV in 9.7 fb-1 of integrated luminosity collected with the DØ detector.

  16. Anomalous U(1)A and electroweak symmetry breaking

    International Nuclear Information System (INIS)

    Gogoladze, I.; Tsulaya, M.

    2000-01-01

    A new mechanism for electroweak symmetry breaking in the supersymmetric Standard Model is suggested. Our suggestion is based on the presence of an anomalous U(1) A gauge symmetry, which naturally arises in the four-dimensional superstring theory, and heavily relies on the corresponding Fayet-Illiopoulos ξ-term

  17. Anomalous U(1)A and electroweak symmetry breaking

    International Nuclear Information System (INIS)

    Gogoladze, Ilia

    2000-10-01

    We suggest a mechanism for electroweak symmetry breaking in the Supersymmetric Standard Model. Our suggestion is based on the presence of an anomalous U(1) A gauge symmetry, which naturally arises in the four dimensional superstring theory, and heavily relies on the value of the corresponding Fayet-Illiopoulos ξ-term. (author)

  18. Electroweak and Higgs boson production at the LHC

    Directory of Open Access Journals (Sweden)

    Lazopoulos Achilleas

    2013-05-01

    Full Text Available I summarize very briefly the status of theory predictions for the production of electroweak and Higgs bosons at the LHC, highlighting recent developments and issues that have attracted the interest of the theory community. The focus is on inclusive and fixed order differential computations and related developments in parton showers are not discussed at all in this contribution.

  19. Higgsless theory of electroweak symmetry breaking from warped space

    International Nuclear Information System (INIS)

    Nomura, Yasunori

    2003-01-01

    We study a theory of electroweak symmetry breaking without a Higgs boson, recently suggested by Csaki et al. The theory is formulated in 5D warped space with the gauge bosons and matter fields propagating in the bulk. In the 4D dual picture, the theory appears as the standard model without a Higgs field, but with an extra gauge group G which becomes strong at the TeV scale. The strong dynamics of G breaks the electroweak symmetry, giving the masses for the W and Z bosons and the quarks and leptons. We study corrections in 5D which are logarithmically enhanced by the large mass ratio between the Planck and weak scales, and show that they do not destroy the structure of the electroweak gauge sector at the leading order. We introduce a new parameter, the ratio between the two bulk gauge couplings, into the theory and find that it allows us to control the scale of new physics. We also present a potentially realistic theory accommodating quarks and leptons and discuss its implications, including the violation of universality in the W and Z boson couplings to matter and the spectrum of the Kaluza-Klein excitations of the gauge bosons. The theory reproduces many successful features of the standard model, although some cancellations may still be needed to satisfy constraints from the precision electroweak data. (author)

  20. Systematics of quark mass matrices in the standard electroweak model

    International Nuclear Information System (INIS)

    Frampton, P.H.; Jarlskog, C.; Stockholm Univ.

    1985-01-01

    It is shown that the quark mass matrices in the standard electroweak model satisfy the empirical relation M = M' + O(lambda 2 ), where M(M') refers to the mass matrix of the charge 2/3 (-1/3) quarks normalized to the largest eigenvalue, msub(t) (msub(b)), and lambda = Vsub(us) approx.= 0.22. (orig.)

  1. Electroweak symmetry breaking: Unitarity, dynamics, and experimental prospects

    International Nuclear Information System (INIS)

    Chanowitz, M.S.

    1988-01-01

    A review of what is known about the unexplained mechanism that breaks the electroweak symmetry and thereby gives mass to the W and Z gauge bosons while leaving the photon massless is given. Symmetry, unitarity, technicolor, supersymmetry, higgs sector dynamics, and experimental status and prospects are discussed

  2. Martinus Veltman, the Electroweak Theory, and Elementary Particle Physics

    Science.gov (United States)

    Particle Physics Resources with Additional Information Martinus Veltman Courtesy University of Michigan Martinus J.G. Veltman, the John D. MacArthur Professor Emeritus of Physics at the University of Michigan , was awarded the 1999 Nobel Prize in physics "for elucidating the quantum structure of electroweak

  3. EXECUTIVE SUMMARY OF THE SNOWMASS 2001 WORKING GROUP : ELECTROWEAK SYMMETRY BREAKING

    International Nuclear Information System (INIS)

    CARENA, M.; GERDES, D.W.; HABER, H.E.; TURCOT, A.S.; ZERWAS, P.M.

    2001-01-01

    In this summary report of the 2001 Snowmass Electroweak Symmetry Breaking Working Group, the main candidates for theories of electroweak symmetry breaking are surveyed, and the criteria for distinguishing among the different approaches are discussed. The potential for observing electroweak symmetry breaking phenomena at the upgraded Tevatron and the LHC is described. We emphasize the importance of a high-luminosity e + e - linear collider for precision measurements to clarify the underlying electroweak symmetry breaking dynamics. Finally, we note the possible roles of the μ + μ - collider and VLHC for further elucidating the physics of electroweak symmetry breaking

  4. Chiral recognition in separation science: an overview.

    Science.gov (United States)

    Scriba, Gerhard K E

    2013-01-01

    Chiral recognition phenomena play an important role in nature as well as analytical separation sciences. In separation sciences such as chromatography and capillary electrophoresis, enantiospecific interactions between the enantiomers of an analyte and the chiral selector are required in order to observe enantioseparations. Due to the large structural variety of chiral selectors applied, different mechanisms and structural features contribute to the chiral recognition process. This chapter briefly illustrates the current models of the enantiospecific recognition on the structural basics of various chiral selectors.

  5. Vector mesons and chiral symmetry

    International Nuclear Information System (INIS)

    Ecker, G.

    1989-01-01

    The ambiguities in the off-shell behaviour of spin-1 exchange can be resolved to O(p 4 ) in the chiral low-energy expansion if the asymptotic behaviour of QCD is properly incorporated. As a consequence, the chiral version of vector (and axial-vector) meson dominance is model independent. Additional high-energy constraints motivated by QCD determine the V,A resonance couplings uniquely. In particular, QCD in its effective chiral realization sucessfully predicts Γ(ρ→2π). 10 refs. (Author)

  6. Nonlinear spectroscopic studies of chiral media

    International Nuclear Information System (INIS)

    Belkin, Mikhail Alexandrovich

    2004-01-01

    Molecular chirality plays an important role in chemistry, biology, and medicine. Traditional optical techniques for probing chirality, such as circular dichroism and Raman optical activity rely on electric-dipole forbidden transitions. As a result, their intrinsic low sensitivity limits their use to probe bulk chirality rather than chiral surfaces, monolayers or thin films often important for chemical or biological systems. Contrary to the traditional chirality probes, chiral signal in sum-frequency generation (SFG) is electric-dipole allowed both on chiral surface and in chiral bulk making it a much more promising tool for probing molecular chirality. SFG from a chiral medium was first proposed in 1965, but had never been experimentally confirmed until this thesis work was performed. This thesis describes a set of experiments successfully demonstrating that chiral SFG responses from chiral monolayers and liquids are observable. It shows that, with tunable inputs, SFG can be used as a sensitive spectroscopic tool to probe chirality in both electronic and vibrational resonances of chiral molecules. The monolayer sensitivity is feasible in both cases. It also discusses the relevant theoretical models explaining the origin and the strength of the chiral signal in vibrational and electronic SFG spectroscopies

  7. Bino-driven electroweak baryogenesis with highly suppressed electric dipole moments

    Energy Technology Data Exchange (ETDEWEB)

    Li Yingchuan [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)], E-mail: yli@physics.wisc.edu; Profumo, Stefano [Department of Physics and Santa Cruz Institute for Particle Physics, University of California, 1156 High St., Santa Cruz, CA 95064 (United States)], E-mail: profumo@scipp.ucsc.edu; Ramsey-Musolf, Michael [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)], E-mail: mjrm@physics.wisc.edu

    2009-03-09

    It is conventional wisdom that successful electroweak baryogenesis in the Minimal Supersymmetric extension of the Standard Model (MSSM) is in tension with the non-observation of electric dipole moments (EDMs), since the level of CP-violation responsible for electroweak baryogenesis is believed to generate unavoidably large EDMs. We show that CP-violation in the bino-Higgsino sector of the MSSM can account for successful electroweak baryogenesis without inducing large EDMs. This observation weakens the correlation between electroweak baryogenesis and EDMs, and makes the bino-driven electroweak baryogenesis scenario the least constrained by EDM limits. Taking this observation together with the requirement of a strongly first-order electroweak phase transition, we argue that a bino-driven scenario with a light stop is the most phenomenologically viable MSSM electroweak baryogenesis scenario.

  8. Bino-driven electroweak baryogenesis with highly suppressed electric dipole moments

    International Nuclear Information System (INIS)

    Li Yingchuan; Profumo, Stefano; Ramsey-Musolf, Michael

    2009-01-01

    It is conventional wisdom that successful electroweak baryogenesis in the Minimal Supersymmetric extension of the Standard Model (MSSM) is in tension with the non-observation of electric dipole moments (EDMs), since the level of CP-violation responsible for electroweak baryogenesis is believed to generate unavoidably large EDMs. We show that CP-violation in the bino-Higgsino sector of the MSSM can account for successful electroweak baryogenesis without inducing large EDMs. This observation weakens the correlation between electroweak baryogenesis and EDMs, and makes the bino-driven electroweak baryogenesis scenario the least constrained by EDM limits. Taking this observation together with the requirement of a strongly first-order electroweak phase transition, we argue that a bino-driven scenario with a light stop is the most phenomenologically viable MSSM electroweak baryogenesis scenario

  9. Studies on phenomenological hadron models with chiral symmetry

    International Nuclear Information System (INIS)

    Rathske, E.

    1991-12-01

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

  10. Deformed chiral nucleons

    Energy Technology Data Exchange (ETDEWEB)

    Price, C E; Shepard, J R [Colorado Univ., Boulder (USA). Dept. of Physics

    1991-04-18

    We compute properties of the nucleon in a hybrid chiral model based on the linear {sigma}-model with quark degrees of freedom treated explicity. In contrast to previous calculations, we do not use the hedgehog ansatz. Instead we solve self-consistently for a state with well defined spin and isospin projections. We allow this state to be deformed and find that, although d- and g-state admixtures in the predominantly s-state single quark wave functions are not large, they have profound effects on many nucleon properties including magnetic moments and g{sub A}. Our best fit parameters provide excellent agreement with experiment but are much different from those determined in hedgehog calculations. (orig.).

  11. Amino Acids and Chirality

    Science.gov (United States)

    Cook, Jamie E.

    2012-01-01

    Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

  12. Description of hot compressed hadronic matter based on an effective chiral Lagrangian

    Energy Technology Data Exchange (ETDEWEB)

    Florkowski, W. [Institute of Nuclear Physics, Cracow (Poland)

    1996-11-01

    In this report we give the review of the recent results obtained in the Nambu-Jona-Lasinio (NJL) model, describing the properties of hot compressed matter. The first large class problems concerns the behaviour of static meson correlation functions. In particular, this includes the investigation of the screening of meson fields at finite temperature or density. Another wide range of problems presented in our report concerns the formulation of the transport theory for the NJL model and its applications to the description of high energy nuclear collision. 86 refs, 35 figs.

  13. Description of hot compressed hadronic matter based on an effective chiral Lagrangian

    International Nuclear Information System (INIS)

    Florkowski, W.

    1996-11-01

    In this report we give the review of the recent results obtained in the Nambu-Jona-Lasinio (NJL) model, describing the properties of hot compressed matter. The first large class problems concerns the behaviour of static meson correlation functions. In particular, this includes the investigation of the screening of meson fields at finite temperature or density. Another wide range of problems presented in our report concerns the formulation of the transport theory for the NJL model and its applications to the description of high energy nuclear collision. 86 refs, 35 figs

  14. Chiral fermions on the lattice

    International Nuclear Information System (INIS)

    Randjbar Daemi, S.; Strathdee, J.

    1995-01-01

    The overlap approach to chiral gauge theories on arbitrary D-dimensional lattices is studied. The doubling problem and its relation to chiral anomalies for D = 2 and 4 is examined. In each case it is shown that the doublers can be eliminated and the well known perturbative results for chiral anomalies can be recovered. We also consider the multi-flavour case and give the general criteria for the construction of anomaly free chiral gauge theories on arbitrary lattices. We calculate the second order terms in a continuum approximation to the overlap formula in D dimensions and show that they coincide with the bilinear part of the effective action of D-dimensional Weyl fermions coupled to a background gauge field. Finally, using the same formalism we reproduce the correct Lorentz, diffeomorphism and gauge anomalies in the coupling of a Weyl fermion to 2-dimensional gravitation and Maxwell fields. (author). 15 refs

  15. Switching of chirality by light

    NARCIS (Netherlands)

    Feringa, B.L.; Schoevaars, A.M; Jager, W.F.; de Lange, B.; Huck, N.P.M.

    1996-01-01

    Optically active photoresponsive molecules are described by which control of chirality is achieved by light. These chiroptical molecular switches are based on inherently dissymmetric overcrowded alkenes and the synthesis, resolution and dynamic stereochemical properties are discussed. Introduction

  16. Chiral dynamics with (nonstrange quarks

    Directory of Open Access Journals (Sweden)

    Kubis Bastian

    2017-01-01

    Full Text Available We review the results and achievements of the project B.3. Topics addressed include pion photoproduction off the proton and off deuterium, three-flavor chiral perturbation theory studies, chiral symmetry tests in Goldstone boson decays, the development of unitarized chiral perturbation theory to next-to-leading order, the two-pole structure of the Λ(1405, the dynamical generation of the lowest S11 resonances, the theory of hadronic atoms and its application to various systems, precision studies in light-meson decays based on dispersion theory, the Roy–Steiner analysis of pion–nucleon scattering, a high-precision extraction of the elusive pion–nucleon σ-term, and aspects of chiral dynamics in few-nucleon systems.

  17. Chiral topological insulator of magnons

    Science.gov (United States)

    Li, Bo; Kovalev, Alexey A.

    2018-05-01

    We propose a magnon realization of 3D topological insulator in the AIII (chiral symmetry) topological class. The topological magnon gap opens due to the presence of Dzyaloshinskii-Moriya interactions. The existence of the topological invariant is established by calculating the bulk winding number of the system. Within our model, the surface magnon Dirac cone is protected by the sublattice chiral symmetry. By analyzing the magnon surface modes, we confirm that the backscattering is prohibited. By weakly breaking the chiral symmetry, we observe the magnon Hall response on the surface due to opening of the gap. Finally, we show that by changing certain parameters, the system can be tuned between the chiral topological insulator, three-dimensional magnon anomalous Hall, and Weyl magnon phases.

  18. Review of chiral perturbation theory

    Indian Academy of Sciences (India)

    Abstract. A review of chiral perturbation theory and recent developments on the comparison of its predictions with experiment is presented. Some interesting topics with scope for further elaboration are touched upon.

  19. Functional integral for non-Lagrangian systems

    CERN Document Server

    Kochan, Denis

    2010-01-01

    A novel functional integral formulation of quantum mechanics for non-Lagrangian systems is presented. The new approach, which we call "stringy quantization," is based solely on classical equations of motion and is free of any ambiguity arising from Lagrangian and/or Hamiltonian formulation of the theory. The functionality of the proposed method is demonstrated on several examples. Special attention is paid to the stringy quantization of systems with a general A-power friction force $-\\kappa[\\dot{q}]^A$. Results for $A = 1$ are compared with those obtained in the approaches by Caldirola-Kanai, Bateman and Kostin. Relations to the Caldeira-Leggett model and to the Feynman-Vernon approach are discussed as well.

  20. An ambitwistor Yang-Mills Lagrangian

    International Nuclear Information System (INIS)

    Mason, L.J.; Skinner, D.

    2006-01-01

    We introduce a Chern-Simons Lagrangian for Yang-Mills theory as formulated on ambitwistor space via the Ward, Isenberg, Yasskin, Green, Witten construction. The Lagrangian requires the selection of a codimension-2 Cauchy-Riemann submanifold which is naturally picked out by the choice of space-time reality structure and we focus on the choice of Euclidean signature. The action is shown to give rise to a space-time action that is equivalent to the standard one, but has just cubic vertices. We identify the ambitwistor propagators and vertices and work out their corresponding expressions on space-time and momentum space. It is proposed that this formulation of Yang-Mills theory underlies the recursion relations of Britto, Cachazo, Feng and Witten and provides the generating principle for twistor diagrams for gauge theory