Raduta, A A
2007-01-01
The Gamow-Teller transition operator is written as a polynomial in the dipole proton-neutron and quadrupole charge conserving QRPA boson operators, using the prescription of the boson expansion technique of Belyaev-Zelevinski type. Then, the $2\
The Gamow-Teller transition operator is written as a polynomial in the dipole proton-neutron and quadrupole charge conserving QRPA boson operators, using the prescription of the boson expansion technique of Belyaev-Zelevinski type. Then, the 2νββ process ending on the first 2+ state in the daughter nucleus is allowed via one, two and three boson states describing the odd-odd intermediate nucleus. The approach uses a single particle basis which is obtained by projecting out the good angular momentum from an orthogonal set of deformed functions. The bases for mother and daughter nuclei have different deformations. The GT transition amplitude as well as the half lives was calculated for eleven transitions. Results are compared with the available data as well as with some predictions obtained with other methods
Loop expansion and the bosonic representation of loop quantum gravity
Bianchi, Eugenio; Hackl, Lucas; Yokomizo, Nelson
2016-01-01
We introduce a new loop expansion that provides a resolution of the identity in the Hilbert space of loop quantum gravity on a fixed graph. We work in the bosonic representation obtained by the canonical quantization of the spinorial formalism. The resolution of the identity gives a tool for implementing the projection of states in the full bosonic representation onto the space of solutions to the Gauss and area matching constraints of loop quantum gravity. This procedure is particularly efficient in the semiclassical regime, leading to explicit expressions for the loop expansions of coherent, heat kernel and squeezed states.
Partial bosonization: The formalism of Cheshire Cat bag models
By bosonizing fermionic theories on only a part of space-time, one obtains idealized bag models where the physics is independent of the bag radius. Such ''Cheshire Cat Models (CCM's)'' were introduced in an earlier paper, where it was suggested that realistic bag models are in fact approximate CCM's. The present paper further explores Abelian CCM's in 1+1 dimensions. First, the boundary action for CCM's is derived in the Lagrangian formalism by demanding invariance under parity and chiral rotations. Next, a quantum reinterpretation of the classical Lagrangian bag boundary conditions is used to obtain the bosonic representation of fermions as soliton operators. Last, these soliton operators are used to construct CCM's in the Hamiltonian framework. The Cheshire Cat criterion - independence of the energy spectrum on the bag radius - is presented as the commuting of the energy and momentum operators for the model. (orig.)
Did the Higgs boson drive the universe's expansion?
2008-01-01
The Higgs boson has been moonlighting. Not content with its day job of giving other particles their mass, it may also have driven the expansion of the early universe, given a little tinkering, according to two separate studies. Soon after the big bang the early universe is believed to have undergone a period of rapid expansion, known as inflation.
1/N expansion in the interacting boson model. II. The neutron-proton degree of freedon
The 1/N expansion method is used to study the neutron-proton degree of freedom in a general boson model. Employing a standard IBM-2 hamiltonian, analytic expressions for energies and electromagnetic transition rates are derived both for the symmetric and mixed-symmetry states. A formalism for F-spin analysis is developed. Effects of the g-boson and F-spin breaking in various quantities are discussed. The method is not restricted to dynamic symmetries and allows for explicit breaking of the F-spin symmetry. Thus, the formulae derived here should be useful for systematic analysis of deformed nuclei in realistic situations. 42 refs., 13 figs
Parameterized type expansion in the feature structure formalism TDL
Schäfer, Ulrich
1995-01-01
Over the last few years, unification-based grammar formalisms have become the predominant paradigm in natural language processing systems because of their monotonicity, declarativeness, and reversibility. From the viewpoint of computer science, typed feature structures can be seen as data structures that allow representation of linguistic knowledge in a uniform fashion. Type expansion is an operation that makes the constraints on a typed feature structure explicit and determines their satisfi...
Formal GNS Construction and WKB Expansion in Deformation Quantization
Bordemann, Martin
1996-01-01
In this contribution we review the formal GNS construction developped in a previous preprint (q-alg/9607019), and formulate the usual WKB-expansion in flat 2n-dimensional phase space in terms of a GNS construction with a positive linear functional with support on a projectable Lagrangean submanifold defined as a graph of an exact one form dS. The main trick is a suitable form of the star-exponential of S.
Heat kernel expansion in the background field formalism
Barvinsky, Andrei
2015-01-01
Heat kernel expansion and background field formalism represent the combination of two calculational methods within the functional approach to quantum field theory. This approach implies construction of generating functionals for matrix elements and expectation values of physical observables. These are functionals of arbitrary external sources or the mean field of a generic configuration -- the background field. Exact calculation of quantum effects on a generic background is impossible. However, a special integral (proper time) representation for the Green's function of the wave operator -- the propagator of the theory -- and its expansion in the ultraviolet and infrared limits of respectively short and late proper time parameter allow one to construct approximations which are valid on generic background fields. Current progress of quantum field theory, its renormalization properties, model building in unification of fundamental physical interactions and QFT applications in high energy physics, gravitation and...
Red'kov, V M
2011-01-01
Tetrad based equation for Dirac-K\\"{a}hler particle is solved in spherical coordinates in the flat Minkocski space-time. Spherical solutions of boson type (J =0,1,2,...) are constructed. After performing a special transformation over spherical boson solutions of the Dirac-K\\"{a}hler equation, 4 \\times 4-matrices U(x) \\Longrightarrow V(x), simple linear expansions of the four rows of new representativeof the Dirac--K\\"{a}hler field V(x) in terms of spherical fermion solutions \\Psi_{i}(x) of the four ordinary Dirac equations have been derived. However, this fact cannot be interpreted as the possibility not to distinguish between the Dirac-K\\"{a}hler field and the system four Dirac fermions. The main formal argument is that the special transformation (I \\otimes S(x)) involved does not belong to the group of tetrad local gauge transformation for Dirac-K\\"{a}hler field, 2-rank bispinor under the Lorentz group. Therefore, the linear expansions between boson and fermion functions are not gauge invariant under the gr...
Contributions to the Study of Thermal States of the Bosonic String in the TFD Formalism
Graça, E L
2007-01-01
We determine the local entropy of the free energy of the quantized open bosonic string in Minkowski spacetime with the most general boundary conditions. We formulate a finite temperature theory of the thermal closed string excitations in anti-de Sitter spacetime within the TFD approach. We write down the thermal states and obtain the entropy and the free energy in the first order expansion of the semiclassical quantization in the center of mass reference frame.
Functional integrals and 1/h expansion in the boson-fermion model
Yan, Jun
2016-06-01
The effective action of boson-fermion model is derived by means of the functional integrals method and Popov-Faddeev canonical transformations. The energy gap equation and excitation spectrum equation are obtained from first order and second order perturbation expansions of functional determinant. In the long wave approximation, some analytical expressions of excitation spectrum are calculated by using the 1/h expansion technique, the results showed that analytical calculation is in good agreement with the numerical calculation. Moreover, the Nambu sum rules of Higgs bosons are analyzed and discussed.
Economic expansion and increase in labout market formality: a poaching approach
Carlos Henrique L. Corseuil
2012-06-01
Full Text Available This paper investigates the relationship between economic expansion and the degree of formalization for the Brazilian labour market in the recent period. We present a theoretical framework that attempts to explain this relationship through the dynamics of firms hiring strategies. The main predictions are: the share of formal employment rises as the unemployment rate falls, and that the formal-informal wage gap increases, at least at the beginning of the economic expansion. In the empirical part, we use longitudinal microdata from a Brazilian household survey to check whether these two predictions are confirmed. To a large extent our results corroborate both predictions.
Free expansion of fermionic dark solitons in a boson-fermion mixture
We use a time-dependent dynamical mean-field-hydrodynamic model to study the formation of fermionic dark solitons in a trapped degenerate Fermi gas mixed with a Bose-Einstein condensate in a harmonic as well as a periodic optical-lattice potential. The dark soliton with a 'notch' in the probability density with a zero at the minimum is simulated numerically as a nonlinear continuation of the first vibrational excitation of the linear mean-field-hydrodynamic equations, as suggested recently for pure bosons. We study the free expansion of these dark solitons as well as the consequent increase in the size of their central notch and discuss the possibility of experimental observation of the notch after free expansion
1994-01-01
Bosonization is a useful technique for studying systems of interacting fermions in low dimensions. It has applications in both particle and condensed matter physics.This book contains reprints of papers on the method as used in these fields. The papers range from the classic work of Tomonaga in the 1950's on one-dimensional electron gases, through the discovery of fermionic solitons in the 1970's, to integrable systems and bosonization on Riemann surfaces. A four-chapter pedagogical introduction by the editor should make the book accessible to graduate students and experienced researchers alik
Massive two-column bosonic fields in the frame-like formalism
Zinoviev, Yu M
2016-01-01
In this paper we develop the frame-like gauge invariant formulation for the massive two-column bosonic fields in (anti) de Sitter space-times. We begin with the partially massless cases in AdS and dS and then we combine these results into the general massive theory. Separate section is devoted to the special case where both columns have equal number of indices.
Simple formalism for efficient derivatives and multi-determinant expansions in quantum Monte Carlo
Filippi, Claudia; Assaraf, Roland; Moroni, Saverio
2016-05-01
We present a simple and general formalism to compute efficiently the derivatives of a multi-determinant Jastrow-Slater wave function, the local energy, the interatomic forces, and similar quantities needed in quantum Monte Carlo. Through a straightforward manipulation of matrices evaluated on the occupied and virtual orbitals, we obtain an efficiency equivalent to algorithmic differentiation in the computation of the interatomic forces and the optimization of the orbital parameters. Furthermore, for a large multi-determinant expansion, the significant computational gain afforded by a recently introduced table method is here extended to the local value of any one-body operator and to its derivatives, in both all-electron and pseudopotential calculations.
Dressed Bosons and Effective Temperature — a Formalism for Helium II
Maćkowiak, Jan; Borycki, Dawid
2012-08-01
The thermodynamics of a free Bose gas with effective temperature scale ˜ {T} and hard-sphere Bose gas with the ˜ {T} scale are studied. ˜ {T} arises as the temperature experienced by a single particle in a quantum gas with 2-body harmonic oscillator interaction Vosc, which at low temperatures is expected to simulate, almost correctly, the attractive part of the interatomic potential VHe between 4He atoms. The repulsive part of VHe is simulated by a hard-sphere (HS) potential. The thermodynamics of this system of HS bosons, with the ˜ {T} temperature scale (HSET), and particle mass and density equal to those of 4He, is investigated, first, by the Bogoliubov-Huang method and next by an improved version of this method, which describes He II in terms of dressed bosons and takes approximate account of those terms of the 2-body repulsion which are linear in the zero-momentum Bose operators a0, a*0 (originally rejected by Bogoliubov). Theoretical heat capacity CV(T) exhibits good agreement, below 1.9 K, with the experimental heat capacity graph observed in 4He at saturated vapour pressure. The phase transition to the He II phase, occurs in the HSET at Tλ = 2.17 K, and is accompanied, in the modified HSET version, by a singularity of CV(T). The fraction of atoms in the momentum condensate at 0 K equals 8.86% and agrees with other theoretical estimates for He II. The fraction of normal fluid falls to 8.37% at 0 K which exceeds the value 0% found in He II.
The $\\{\\beta\\}$-expansion formalism in perturbative QCD and its extension
Kataev, A L
2016-01-01
We discuss the $\\{ \\beta \\}$-expansion for renormalization group invariant quantities tracing this expansion to the different contractions of the corresponding incomplete BPHZ $R$-operation. All of the coupling renormalizations, which follow from these contractions, should be taken into account for the $\\{ \\beta \\}$-expansion. We illustrate this feature considering the nonsinglet Adler function $D^\\text{NS}$ in the third order of perturbation. We propose a generalization of the $\\{ \\beta \\}$-expansion for the renormalization group covariant quantities -- the $\\{ \\beta,\\gamma \\}$-expansion.
Interference of composite bosons
Brougham, Thomas; Barnett, Stephen M.; Jex, Igor
2010-01-01
We investigate multi-boson interference. A Hamiltonian is presented that treats pairs of bosons as a single composite boson. This Hamiltonian allows two pairs of bosons to interact as if they were two single composite bosons. We show that this leads to the composite bosons exhibiting novel interference effects such as Hong-Ou-Mandel interference. We then investigate generalizations of the formalism to the case of interference between two general composite bosons. Finally, we show how one can ...
Bosonization of the generalized SU(3) Nambu-Jona-Lasinio model in the 1/N expansion
The present work consists in a 1/N expansion of extended version of the SU(3) Nambu-Jona-Lasinio model in the context of the Functional Integral. The gap equations, meson propagators, triangle diagram, etc, appear quite naturally as different orders in the expansion. The new features of this approach is the inclusion of high order corrections in the 1/N leading orders, which have never included in the previous one. The method also allows for the construction of a chiral Lagrangian of interacting mesons based on the SU(3) NJL model, here obtained for the first time. (author)
Gauge-Invariant Formalism with Dirac-mode Expansion for Confinement and Chiral Symmetry Breaking
Gongyo, Shinya; Suganuma, Hideo
2012-01-01
We develop a manifestly gauge-covariant expansion of the QCD operator such as the Wilson loop, using the eigen-mode of the QCD Dirac operator $\\Slash D=\\gamma^\\mu D^\\mu$. With this method, we perform a direct analysis of the correlation between confinement and chiral symmetry breaking in lattice QCD Monte Carlo calculation on $6^4$ at $\\beta$=5.6. As a remarkable fact, the confinement force is almost unchanged even after removing the low-lying Dirac modes, which are responsible to chiral symmetry breaking. This indicates that one-to-one correspondence does not hold for between confinement and chiral symmetry breaking in QCD. In this analysis, we carefully amputate only the "essence of chiral symmetry breaking" by cutting off the low-lying Dirac modes, and can artificially realize the "confined but chiral restored situation" in QCD.
Lattice Boltzmann method for bosons and fermions and the fourth order Hermite polynomial expansion
Coelho, Rodrigo C V; Doria, M M; Pereira, R M; Aibe, Valter Yoshihiko
2013-01-01
The Boltzmann equation with the Bhatnagar-Gross-Krook collision operator is considered for the Bose-Einstein and Fermi-Dirac equilibrium distribution functions. We show that the expansion of the microscopic velocity in terms of Hermite polynomials must be carried until the fourth order to correctly describe the energy equation. The viscosity and thermal coefficients, previously obtained by J.Y. Yang et al through the Uehling-Uhlenbeck approach, are also derived here. Thus the construction of a lattice Boltzmann method for the quantum fluid is possible provided that the Bose-Einstein and Fermi-Dirac equilibrium distribution functions are expanded until fourth order in the Hermite polynomials.
Hauschild, Johannes; Pollmann, Frank; Heidrich-Meisner, Fabian
2015-11-01
We numerically investigate the expansion of clouds of hard-core bosons in the two-dimensional square lattice using a matrix-product-state-based method. This nonequilibrium setup is induced by quenching the trapping potential to zero and our work is specifically motivated by a recent experiment with interacting bosons in an optical lattice [Ronzheimer et al., Phys. Rev. Lett. 110, 205301 (2013), 10.1103/PhysRevLett.110.205301]. As the anisotropy of the amplitudes Jx and Jy for hopping in different spatial directions is varied from the one- to the two-dimensional case, we observe a crossover from a fast ballistic expansion in the one-dimensional limit Jx≫Jy to much slower dynamics in the isotropic two-dimensional limit Jx=Jy . We further study the dynamics on multileg ladders and long cylinders. For these geometries we compare the expansion of a cloud to the melting of a domain wall, which helps us to identify several different regimes of the expansion as a function of time. By studying the dependence of expansion velocities on both the anisotropy Jy/Jx and the number of legs, we observe that the expansion on two-leg ladders, while similar to the two-dimensional case, is slower than on wider ladders. We provide a qualitative explanation for this observation based on an analysis of the rung spectrum.
The Higgs boson and the quark top in the formalism of dispersion relations and the standard model
The mechanism of spontaneous symmetry breaking responsible for the generation of masses for both the bosons and the fermions of the Standard Model remains a mystery, especially that the Higgs has still not been discovered. In this thesis I concentrate on the study of the scalar sector of the Standard Model where the Higgs with the other Goldstone Bosons reside. This sector can best be probed through the massive vector bosons and the top quark. The former, for their privileged coupling to the Higgs and because their longitudinal mode represents the Goldstone Bosons, and the top, because of its very strong Yukawa coupling, are very sensitive to the mechanism of symmetry breaking. I first focus on a situation where the Higgs is light and study the processes W-W+ → tt-bar and ZZ → tt-bar. In order to unambiguously reveal a sign of New Physics, the Standard Model needs to be predicted precisely. In a first step I therefore study the electroweak and QCD one loop corrections for these processes. This requires a renormalisation of the electroweak gauge and top sectors and mastering some one-loop techniques. I then concentrate on extracting the purely electroweak contributions to the above processes after setting up an analytical formula for the universal photonic contribution. The New Physics affecting the top and W system is parameterized with the help of effective operators describing symmetry breaking. The effect of these operators is carefully compared to the effect of the one-loop radiative corrections before setting a limit on the parameters of these New Physics operators. To give more realistic results the WW and ZZ cross sections are turned into e+e- and pp cross sections by using a structure function approach. This allows an application to the phenomenology at future colliders (LHC:Large Hadron Collider and ILC: International Linear Collider). A second aspect of the work presented here concerns the situation where the Higgs is heavy. For a heavy Higgs the
Jose, R.; Raju, S. E-mail: sraju@igcar.ernet.in; Divakar, R.; Mohandas, E.; Panneerselvam, G.; Antony, M.P.; Sivasubramanian, K
2003-04-01
The thermal expansion of a titanium modified, swelling resistant austenitic stainless steel designated as D9 is studied by measuring the lattice parameter as a function of temperature in the range 300-1300 K by high-temperature X-ray diffraction technique. The thermal expansion data thus obtained is in reasonable agreement with the typical thermal expansion values reported for similar nuclear grade austenitic stainless steels. However, at temperatures exceeding 900 K, the measured thermal expansivity exhibits a pronounced non-linear increase due partly to the precipitation of complex carbide and intermetallic phases. The high-temperature thermal expansion data obtained in the present study are augmented by modelling the low-temperature thermal expansion behaviour by Grueneisen formalism.
The thermal expansion of a titanium modified, swelling resistant austenitic stainless steel designated as D9 is studied by measuring the lattice parameter as a function of temperature in the range 300-1300 K by high-temperature X-ray diffraction technique. The thermal expansion data thus obtained is in reasonable agreement with the typical thermal expansion values reported for similar nuclear grade austenitic stainless steels. However, at temperatures exceeding 900 K, the measured thermal expansivity exhibits a pronounced non-linear increase due partly to the precipitation of complex carbide and intermetallic phases. The high-temperature thermal expansion data obtained in the present study are augmented by modelling the low-temperature thermal expansion behaviour by Grueneisen formalism
Description of deformed nuclei in the sdg boson model
S. C. Li; Kuyucak, S.
1996-01-01
We present a study of deformed nuclei in the framework of the sdg interacting boson model utilizing both numerical diagonalization and analytical $1/N$ expansion techniques. The focus is on description of high-spin states which have recently become computationally accessible through the use of computer algebra in the $1/N$ expansion formalism. A systematic study is made of high-spin states in rare-earth and actinide nuclei.
Description of deformed nuclei in the sdg boson model
Li, S C
1996-01-01
We present a study of deformed nuclei in the framework of the sdg interacting boson model utilizing both numerical diagonalization and analytical 1/N expansion techniques. The focus is on description of high-spin states which have recently become computationally accessible through the use of computer algebra in the 1/N expansion formalism. A systematic study is made of high-spin states in rare-earth and actinide nuclei.
High-spin states in boson models with applications to actinide nuclei
Kuyucak, S
1995-01-01
We use the 1/N expansion formalism in a systematic study of high-spin states in the sd and sdg boson models with emphasis on spin dependence of moment of inertia and E2 transitions. The results are applied to the high-spin states in the actinide nuclei ^{232}Th, ^{234-238}U, where the need for g bosons is especially acute but until now, no realistic calculation existed. We find that the d-boson energy plays a crucial role in description of the high-spin data.
Higgs boson gluon-fusion production beyond threshold in N 3 LO QCD
Anastasiou, Charalampos(Institute for Theoretical Physics, ETH Zürich, Zürich, 8093, Switzerland); Duhr, Claude; Dulat, Falko; Furlan, Elisabetta; Gehrmann, Thomas; Herzog, Franz; Mistlberger, Bernhard
2015-01-01
In this article, we compute the gluon fusion Higgs boson cross-section at N 3 LO through the second term in the threshold expansion. This calculation constitutes a major milestone towards the full N 3 LO cross section. Our result has the best formal accuracy in the threshold expansion currently available, and includes contributions from collinear regions besides subleading corrections from soft and hard regions, as well as certain logarithmically enhanced contributions for general kinematics....
Deformation quantization of bosonic strings
Deformation quantization of bosonic strings is considered. We show that the light-cone gauge is the most convenient classical description to perform the quantization of bosonic strings in the deformation quantization formalism. Similar to the field theory case, the oscillator variables greatly facilitates the analysis. The mass spectrum, propagators and the Virasoro algebra are finally described within this deformation quantization scheme. (author)
An introduction to boson-sampling
Gard, Bryan T; Motes, Keith R.; Olson, Jonathan P.; Rohde, Peter P.; Dowling, Jonathan P.
2014-01-01
Boson-sampling is a simplified model for quantum computing that may hold the key to implementing the first ever post-classical quantum computer. Boson-sampling is a non-universal quantum computer that is significantly more straightforward to build than any universal quantum computer proposed so far. We begin this chapter by motivating boson-sampling and discussing the history of linear optics quantum computing. We then summarize the boson-sampling formalism, discuss what a sampling problem is...
Fermion-fermion and boson-boson amplitudes: surprising similarities
Dvoeglazov, Valeri V
2007-01-01
Amplitudes for fermion-fermion, boson-boson and fermion-boson interactions are calculated in the second order of perturbation theory in the Lobachevsky space. An essential ingredient of the model is the Weinberg's 2(2j+1)-component formalism for describing a particle of spin j. The boson-boson amplitude is then compared with the two-fermion amplitude obtained long ago by Skachkov on the basis of the Hamiltonian formulation of quantum field theory on the mass hyperboloid, p_0^2 - p^2=M^2, proposed by Kadyshevsky. The parametrization of the amplitudes by means of the momentum transfer in the Lobachevsky space leads to same spin structures in the expressions of T-matrices for the fermion case and the boson case. However, certain differences are found. Possible physical applications are discussed.
Is geometry bosonic or fermionic?
Hughes, Taylor L
2011-01-01
It is generally assumed that the gravitational field is bosonic. Here we show that a simple propagating torsional theory can give rise to localized geometric structures that can consistently be quantized as fermions under exchange. To demonstrate this, we show that the model can be formally mapped onto the Skyrme model of baryons, and we use well-known results from Skyrme theory. This begs the question: {\\it Is geometry bosonic or fermionic (or both)?}
Resummation of High Order Corrections in Higgs Boson Plus Jet Production at the LHC
Sun, Peng; Yuan, C -P; Yuan, Feng
2016-01-01
We study the effect of multiple parton radiation to Higgs boson plus jet production at the LHC, by applying the transverse momentum dependent (TMD) factorization formalism to resum large logarithmic contributions to all orders in the expansion of the strong interaction coupling. We show that the appropriate resummation scale should be the jet transverse momentum, rather than the partonic center of mass energy which has been normally used in the TMD resummation formalism. Furthermore, the transverse momentum distribution of the Higgs boson, particularly near the lower cut-off applied on the jet transverse momentum, can only be reliably predicted by the resummation calculation which is free of the so-called Sudakov-shoulder singularity problem, present in fixed-order calculations.
Probing anomalous gauge boson couplings at LEP
We bound anomalous gauge boson couplings using LEP data for the Z → bar ∫∫ partial widths. We use an effective field theory formalism to compute the one-loop corrections resulting from non-standard model three and four gauge boson vertices. We find that measurements at LEP constrain the three gauge boson couplings at a level comparable to that obtainable at LEPII
Sahle, Esther
2014-01-01
During the late seventeenth century the Atlantic trade experienced unprecedented growth. The New Institutional Economists attribute this to the emergence of new institutions for property rights enforcement. During this period, Quakers emerged as the region’s most prominent trading community. This paper constitutes the first study of the London Quaker community. In contrast to the literature, claiming that they enjoyed a competitive advantage due to their church’s formal institutions for co...
Boson representation of the asymmetric rotator
The yrast states, as well as the wobbling frequency are analyzed using alternatively the Holstein-Primakoff and Dyson boson expansions. Both the prolate and oblate shapes are treated using Oz as quantization axis. (author)
A general approach to bosonization
Girish S Setulur; V Meera
2007-10-01
We summarize recent developments in the ﬁeld of higher dimensional bosonization made by Setlur and collaborators and propose a general formula for the ﬁeld operator in terms of currents and densities in one dimension using a new ingredient known as a `singular complex number'. Using this formalism, we compute the Green function of the homogeneous electron gas in one spatial dimension with short-range interaction leading to the Luttinger liquid and also with long-range interactions that lead to a Wigner crystal whose momentum distribution computed recently exhibits essential singularities. We generalize the formalism to ﬁnite temperature by combining with the author's hydrodynamic approach. The one-particle Green function of this system with essential singularities cannot be easily computed using the traditional approach to bosonization which involves the introduction of momentum cutoffs, hence the more general approach of the present formalism is proposed as a suitable alternative.
An Introduction to Boson-Sampling
Gard, Bryan T.; Motes, Keith R.; Olson, Jonathan P.; Rohde, Peter P.; Dowling, Jonathan P.
2015-06-01
Boson-sampling is a simplified model for quantum computing that may hold the key to implementing the first ever post-classical quantum computer. Boson-sampling is a non-universal quantum computer that is significantly more straightforward to build than any universal quantum computer proposed so far. We begin this chapter by motivating boson-sampling and discussing the history of linear optics quantum computing. We then summarize the boson-sampling formalism, discuss what a sampling problem is, explain why boson-sampling is easier than linear optics quantum computing, and discuss the Extended Church-Turing thesis. Next, sampling with other classes of quantum optical states is analyzed. Finally, we discuss the feasibility of building a boson-sampling device using existing technology.
Introduction to bosonic string theory
This is an introductory set of five lectures on bosonic string theory. The first one deals with the classical theory of bosonic strings. The second and third lectures cover quantization. Three basic quantization methods are sketched: the old covariant formalism, the light-cone gauge quantization, where the spectrum is derived and the Polyakov path integral formalism and in particular the partition function at one loop. Finally, the last lecture covers interactions, low energy effective action, the general idea of compactification and in particular toroidal compactification. The notes are based on books by Green, Schwarz and Witten, Polchinski, Lust and Theissen and Kaku and review papers by D'Hocker and Phong and O. Alvarez. (author)
Tichy, Malte C.; Bouvrier, P. Alexander; Mølmer, Klaus
2013-01-01
Composite bosons made of two bosonic constituents exhibit deviations from ideal bosonic behavior due to their substructure. This deviation is reflected by the normalization ratio of the quantum state of N composites. We find a set of saturable, efficiently evaluable bounds for this indicator, which...... quantifies the bosonic behavior of composites via the entanglement of their constituents. We predict an abrupt transition between ordinary and exaggerated bosonic behavior in a condensate of two-boson composites....
This is a pedagogical introduction to the general technique of bosonization of one-dimensional systems starting from scratch and assuming very little besides basic quantum mechanics and second quantization. The formalism is developed in a self-contained fashion and applied to the spinless and spin-1/2 Luttinger models, working out both single and two particle correlation functions. The implications of these results for the specific cases of the (anisotropic) Heisenberg and the Hubbard models are discussed. Although everything in these notes can be found in the published literature, detailed and explicit calculations of most of the results are given, which may prove useful to beginning graduate students or researchers in this area. (author)
Bosonization and quantum hydrodynamics
Girish S Setlur
2006-03-01
It is shown that it is possible to bosonize fermions in any number of dimensions using the hydrodynamic variables, namely the velocity potential and density. The slow part of the Fermi field is defined irrespective of dimensionality and the commutators of this field with currents and densities are exponentiated using the velocity potential as conjugate to the density. An action in terms of these canonical bosonic variables is proposed that reproduces the correct current and density correlations. This formalism in one dimension is shown to be equivalent to the Tomonaga-Luttinger approach as it leads to the same propagator and exponents. We compute the one-particle properties of a spinless homogeneous Fermi system in two spatial dimensions with long-range gauge interactions and highlight the metal-insulator transition in the system. A general formula for the generating function of density correlations is derived that is valid beyond the random phase approximation. Finally, we write down a formula for the annihilation operator in momentum space directly in terms of number conserving products of Fermi fields.
Aharonov--Bohm problem for vector bosons
Castro, Luis B
2015-01-01
The Aharonov--Bohm (AB) problem for vector bosons by the Duffin--Kemmer--Petiau (DKP) formalism is analyzed. The relevant eigenvalue equation coming from the DKP formalism reveals an equivalence to the spin--$1/2$ AB problem. By using the self--adjoint extension approach, we examine the bound state scenario. The energy spectra are explicitly computed as well as their dependencies on the magnetic flux parameter and also the conditions for the occurrence of bound states.
Boson condensation in topologically ordered quantum liquids
Neupert, Titus; He, Huan; von Keyserlingk, Curt; Sierra, Germán; Bernevig, B. Andrei
2016-03-01
Boson condensation in topological quantum field theories (TQFT) has been previously investigated through the formalism of Frobenius algebras and the use of vertex lifting coefficients. While general, this formalism is physically opaque and computationally arduous: analyses of TQFT condensation are practically performed on a case by case basis and for very simple theories only, mostly not using the Frobenius algebra formalism. In this paper, we provide a way of treating boson condensation that is computationally efficient. With a minimal set of physical assumptions, such as commutativity of lifting and the definition of confined particles, we can prove a number of theorems linking Boson condensation in TQFT with chiral algebra extensions, and with the factorization of completely positive matrices over Z+. We present numerically efficient ways of obtaining a condensed theory fusion algebra and S matrices; and we then use our formalism to prove several theorems for the S and T matrices of simple current condensation and of theories which upon condensation result in a low number of confined particles. We also show that our formalism easily reproduces results existent in the mathematical literature such as the noncondensability of five and ten layers of the Fibonacci TQFT.
Dave Odden
2013-02-01
Full Text Available Normal 0 false false false EN-US JA X-NONE Two problematic trends have dominated modern phonological theorizing: over-reliance on machinery of Universal Grammar, and reification of functional properties in grammar. The former trend leads to arbitrary postulation of grammatical principles because UG “has no cost”, which leads to a welter of contradictory and unresolvable claims. The latter trend amounts to rejection of phonology and indeed grammatical computation, as a legitimate independent area of scientific investigation. This paper outlines Formal Phonology, which is a metatheoretical approach rooted in an inductive epistemology, committed to seriously engaging the fundamental logic of the discipline, one which demands justification of claims and an integrated consideration of what is known about phonological grammars, eschewing ad libitum conjectures and isolated positing of novel claims without evaluating how the claim interacts with other aspects of phonology. Debate over the proper mechanism for apparent segment-transparency in harmony, or the binary vs. privative nature of features, is ultimately doomed if we do not have a clear awareness of what a “grammar” and a “phonology” are. Misconstruing the nature of a phonology as being a model of observed behavior negatively affects theoretical choices, leads to confusion over what could motivate a claim about the nature of grammar, and in general, a lack of developed epistemological foundation leads to confusion over how to approach theory-construction.
Exactly solvable models of proton and neutron interacting bosons
We describe a class of exactly-solvable models of interacting bosons based on the algebra SO(3, 2). Each copy of the algebra represents a system of neutron and proton bosons in a given bosonic level interacting via a pairing interaction. The model that includes s and d bosons is a specific realization of the IBM2, restricted to the transition regime between vibrational and γ-soft nuclei. By including additional copies of the algebra, we can generate proton-neutron boson models involving other boson degrees of freedom, while still maintaining exact solvability. In each of these models, we can study not only the states of maximal symmetry, but also those of mixed symmetry, albeit still in the vibrational to γ-soft transition regime. Furthermore, in each of these models we can study some features of F-spin symmetry breaking. We report systematic calculations as a function of the pairing strength for models based on s,d, and g bosons and on s,d, and f bosons. The formalism of exactly-solvable models based on the SO(3, 2) algebra is not limited to systems of proton and neutron bosons, however, but can also be applied to other scenarios that involve two species of interacting bosons
Worldline Formalism and Noncommutative Theories
Franchino-Viñas, Sebastián A
2015-01-01
The objective of this Ph.D. thesis is the implementation of the Worldline Formalism in the frame of Noncommutative Quantum Field Theories. The result is a master formula for the 1-loop effective action that is applied to a number of scalar models -- among them the Grosse-Wulkenhaar model. As a byproduct we find an expression for the small propertime expansion of general nonlocal operators' Heat Kernel. As an introduction, basic notions of spectral functions, Quantum Field Theories --path integrals and renormalization by means of spectral functions-- and the Worldline Formalism for commutative theories are given.
Veltman, Martinus J. G.
1986-01-01
Reports recent findings related to the particle Higgs boson and examines its possible contribution to the standard mode of elementary processes. Critically explores the strengths and uncertainties of the Higgs boson and proposed Higgs field. (ML)
Higgs boson : production and decays into bosons
Escalier, Marc; The ATLAS collaboration
2016-01-01
The results on the Higgs boson with decay channels into bosons from the ATLAS and CMS experiments at LHC Run 1 and early Run 2 are reviewed in the context of the Standard Model. : observation of a signal, measurement of mass, width, spin, cross-sections, search for decay channels and production modes, Higgs couplings to various particles.
Scattering problem for four-boson system
The s-wave phase shift of boson-triboson scattering has been obtained by solving the Faddeev-Osborn equation in the exact approach based on rigorous Faddeev theory. The Schmidt expansion theorem is used to express the 3+1- and 2+2-subamplitudes at energies in the continuous spectrum region as an infinite series of separable terms. Employing the pole term decomposition for these subamplitudes expressed in terms of the Schmidt expansion we can define, in conformity with the Faddeev residue prescription, respective four-nucleon amplitudes that describe elastic/rearrangement, partial breakup and full breakup scattering processes. Acquired simultaneous equations of these amplitudes take the form of multichannel two-particle Lippmann-Schwinger type, which we call Faddeev-Osborn equation. Assuming as an s-wave spin-independent, rank one separable potential of the Yamaguchi type for the two-particle interaction, are derived the Faddeev-Osborn equation for the boson-triboson elastic scattering. To treat singularities appeared in our equation, the numerical calculation is performed in the framework of the complex-valued analysis by introducing contour rotation method. The boson-triboson elastic scattering amplitude for L=0 state of a four-boson system is obtained numerically in the incident boson laboratory energy region of 0.01-24.0 Mev, including only 1=0 state for the 3+1-subamplitude. The results of the phase shift obtained from the amplitudes are plotted as dots in Fig. 1. (author)
Microscopic approach to the interacting boson model
A method is outlined for analyzing the interacting boson model microscopically in terms of S- and D-fermion pairs. We derive the number operator approximation (NOA) of Otsuka and Arima by considering functions that generate normalizations and matrix elements of states built of S-pairs. An extension of the formalism leads to a generalization of the NOA including both S and D. This approximation is suggested as a starting point for determining the collective SD subspace in a dynamical way. The simplified fermion problem that results from restriction of the hamiltonian to the SD subspace can be mapped onto a corresponding sd boson problem. Due to the finiteness of the spermion space, and the non-orthogonality of the collective SD basis, the boson hamiltonian obtained is non-hermitian. (orig.)
Two-level interacting boson models beyond the mean field
Arias, J M; García-Ramos, J E; Vidal, J
2007-01-01
The phase diagram of two-level boson Hamiltonians, including the Interacting Boson Model (IBM), is studied beyond the standard mean field approximation using the Holstein-Primakoff mapping. The limitations of the usual intrinsic state (mean field) formalism concerning finite-size effects are pointed out. The analytic results are compared to numerics obtained from exact diagonalizations. Excitation energies and occupation numbers are studied in different model space regions (Casten triangle for IBM) and especially at the critical points.
Resummation of Goldstone boson contributions to the MSSM effective potential
Kumar, Nilanjana; Martin, Stephen P.
2016-07-01
We discuss the resummation of the Goldstone boson contributions to the effective potential of the minimal supersymmetric Standard Model. This eliminates the formal problems of spurious imaginary parts and logarithmic singularities in the minimization conditions when the tree-level Goldstone boson squared masses are negative or approach zero. The numerical impact of the resummation is shown to be almost always very small. We also show how to write the two-loop minimization conditions so that Goldstone boson squared masses do not appear at all, and so that they can be solved without iteration.
Resummation of Goldstone boson contributions to the MSSM effective potential
Kumar, Nilanjana
2016-01-01
We discuss the resummation of the Goldstone boson contributions to the effective potential of the Minimal Supersymmetric Standard Model (MSSM). This eliminates the formal problems of spurious imaginary parts and logarithmic singularities in the minimization conditions when the tree-level Goldstone boson squared masses are negative or approach zero. The numerical impact of the resummation is shown to be almost always very small. We also show how to write the two-loop minimization conditions so that Goldstone boson squared masses do not appear at all, and so that they can be solved without iteration.
Noninertial effects on the quantum dynamics of scalar bosons
The noninertial effect of rotating frames on the quantum dynamics of scalar bosons embedded in the background of a cosmic string is considered. In this work, scalar bosons are described by the Duffin-Kemmer-Petiau (DKP) formalism. Considering the DKP oscillator in this background the combined effects of a rotating frames and cosmic string on the equation of motion, energy spectrum, and DKP spinor are analyzed and discussed in detail. Additionally, the effect of rotating frames on the scalar bosons' localization is studied. (orig.)
Noninertial effects on the quantum dynamics of scalar bosons
Castro, Luis B. [Universidade Federal do Maranhao, Departamento de Fisica, Sao Luis, MA (Brazil)
2016-02-15
The noninertial effect of rotating frames on the quantum dynamics of scalar bosons embedded in the background of a cosmic string is considered. In this work, scalar bosons are described by the Duffin-Kemmer-Petiau (DKP) formalism. Considering the DKP oscillator in this background the combined effects of a rotating frames and cosmic string on the equation of motion, energy spectrum, and DKP spinor are analyzed and discussed in detail. Additionally, the effect of rotating frames on the scalar bosons' localization is studied. (orig.)
The Conformal Window from the Worldline Formalism
Armoni, Adi
2009-01-01
We use the worldline formalism to derive a universal relation for the lower boundary of the conformal window in non-supersymmetric QCD-like theories. The derivation relies on the convergence of the expansion of the fermionic determinant in terms of Wilson loops. The expansion shares a similarity with the lattice strong coupling expansion and the genus expansion in string theory. Our result relates the lower boundary of the conformal window in theories with different representations and different gauge groups. Finally, we use SQCD to estimate the boundary of the conformal window in QCD-like theories and compare it with other approaches.
Boson mappings for elementary excitations in fermion systems
The boson mapping formalism is presented with a dual purpose in mind. It is first demonstrated to constitute a microscopic formalism leading to the introduction of collective variables into the many-fermion problem in an exact and consistent manner. Secondly it is shown to present ideal exploring ground with a view to the reconciliation of phenomenological collective nuclear models and microscopic considerations. Of the various existing possibilities for the construction of a boson mapping, we single out the finite, non-unitary Dyson-Maleev mapping, emphasising the convenience of its finiteness, especially in investigations concerning formal aspects of the boson mapping formalism. A contribution to the theory of Dyson-Maleev mappinigs for fermion operators is made by introducing the construction of a consistent mapping for single fermion operators which is free of limitations previously imposed on such a mapping. In various fermion models studies it is shown how the Dyson-Maleev mapping can be utilized to obtain equivalent boson models which, however, can be restricted to yield information about the collective subspace only. As far as phenomenological models are concerned, some new light from a microscopic viewpiont is shed on the assumption underlying the interacting boson model as well as on the calculational procedures usually adopted in this model. The most important observation concerns the assumed structure of the IBM hamiltonian where a non-hermitian form, rather than the existing hermitian form, is indicated
Bosonic behavior of entangled fermions
C. Tichy, Malte; Alexander Bouvrie, Peter; Mølmer, Klaus
2012-01-01
Two bound, entangled fermions form a composite boson, which can be treated as an elementary boson as long as the Pauli principle does not affect the behavior of many such composite bosons. The departure of ideal bosonic behavior is quantified by the normalization ratio of multi-composite-boson st......Two bound, entangled fermions form a composite boson, which can be treated as an elementary boson as long as the Pauli principle does not affect the behavior of many such composite bosons. The departure of ideal bosonic behavior is quantified by the normalization ratio of multi...
Taratuta, Rostislav
2015-01-01
The main purpose of this paper is to introduce the new bosonic mechanism and newtreatment of dark energy. The bosonic mechanism focuses on obtaining masses by gauge bosonswithout assuming the existence of Higgs boson. The hypothesis on dark energy as the energy ofa postulated dark field was made and a combined gravitational-dark field was introduced. This fieldis the key to a specified approach and allows addressing the fundamental starting points of the mechanism.i. Complex scalar field is i...
Liew, T. C. H.; Glazov, M. M.; Kavokin, K. V.; Shelykh, I. A.; Kaliteevski, M A; Kavokin, A.V.
2012-01-01
We propose a concept of a quantum cascade laser based on transitions of bosonic quasiparticles (excitons and exciton-polaritons) in a parabolic potential trap in a semiconductor microcavity. This laser would emit terahertz radiation due to bosonic stimulation of excitonic transitions. Dynamics of a bosonic cascade is strongly different from the dynamics of a conventional fermionic cascade laser. We show that populations of excitonic ladders are parity-dependent and quantized if the laser oper...
Equivalence relations between interacting Kemmer-Duffin and Klein-Gordon spin 0 and 1 boson fields
Two formalisms- the Kemmer-Duffin and Klein-Gordon ones - are considered parallely in the spin 0 and 1 cases. Using the S-matrix approach which bases on interaction Lagrangian the transitions between the formalisms are found. A more detailed study is made for one-boson and two-boson interactions. An equivalence between the formalisms inside certain quite natural preconditions is evident
Path-Integral Bosonization of Massive Gauged Thirring Model
Bufalo, R
2011-01-01
In this work the bosonization of two-dimensional massive gauged Thirring model in the path-integral framework is presented. After completing the bosonization prescription, by the fermionic mass expansion, we perform an analysis of the strong coupling regime of the model through the transition amplitude, regarding the intention of extending the previous result about the isomorphisms, at quantum level, of the massless gauged Thirring model to the massive case.
Application of the coherent state formalism to multiply excited states
A general expression is obtained for the matrix element of an m-body operator between coherent states constructed from multiple orthogonal coherent boson species. This allows the coherent state formalism to be applied to states possessing an arbitrarily large number of intrinsic excitation quanta. For illustration, the formalism is applied to the two-dimensional vibron model (U(3) model), to calculate the energies of all excited states in the large-N limit
Campos, Francisco Antonio Pena
1995-12-31
The present work consists in a 1/N expansion of extended version of the SU(3) Nambu-Jona-Lasinio model in the context of the Functional Integral. The gap equations, meson propagators, triangle diagram, etc, appear quite naturally as different orders in the expansion. The new features of this approach is the inclusion of high order corrections in the 1/N leading orders, which have never included in the previous one. The method also allows for the construction of a chiral Lagrangian of interacting mesons based on the SU(3) NJL model, here obtained for the first time. (author) 32 refs., 11 figs., 5 tabs.
Masses of Formal Philosophy is an outgrowth of Formal Philosophy. That book gathered the responses of some of the most prominent formal philosophers to five relatively open and broad questions initiating a discussion of metaphilosophical themes and problems surrounding the use of formal methods in...... philosophy. Including contributions from a wide range of philosophers, Masses of Formal Philosophy contains important new responses to the original five questions....
A Higgs boson is a particle whose existence is predicted in a class of quantum field theories in which a symmetry under a Lie group of transformations of the fields is spontaneously broken by an asymmetric vacuum state. It is a quantum of certain excitations of the order parameter. Such spontaneous symmetry breaking was first proposed as a feature of theories of elementary particles in 1960, but it has a much longer history in the contest of condensed matter theory: in ferromagnetism as early as 1928, in superfluidity and also in superconductivity. It was Nambu who in 1960 first proposed relativistic models inspired by BCS theory as a means of generating fermion masses in elementary particle physics but the hadronic models he proposed lacked the local gauge invariance of their prototype. The connection between spontaneous symmetry and Goldstone bosons in relativistic theories were formally proved in 1962 but the experimental evidence against the existence of such particles in the real world cast a doubt on the viability of Nambu's ideas. Between 1962 and 1964 a debate developed in the literature about whether the Goldstone theorem could be evaded. The resolution of this difficulty finally came in 1964, when Higgs realized that theories with a local gauge invariance fail to satisfy one of the axioms on which the 1962 proof of the Goldstone theorem depends. By the end of July 1964, Higgs had also written down the simplest field-theoretic model that is now known as the Higgs model. (A.C.)
2008-01-01
Quantum physicists think they know the answer. Probabilistic calculations reveal than the data provided by previous experiments has been miscalculated and that the Higgs boson has in fact been discovered. Weird! The Higgs boson is the only particle predicted by the Standard Model that hasn't been discovered yet.
Pimenta, Jean Jûnio Mendes; Natti, Érica Regina Takano; Natti, Paulo Laerte
2013-01-01
The Higgs boson was predicted in 1964 by British physicist Peter Higgs. The Higgs is the key to explain the origin of the mass of other elementary particles of Nature. However, only with the coming into operation of the LHC, in 2008, there were technological conditions to search for the Higgs boson. Recently, a major international effort conducted at CERN, by means of ATLAS and CMS experiments, has enabled the observation of a new bosonic particle in the region of 125 GeVs. In this paper, by means of known mechanisms of symmetry breaking that occur in the BCS theory of superconductivity and in the theory of nuclear pairing, we discuss the Higgs mechanism in the Standard Model. Finally, we present the current state of research looking for the Higgs boson and the alternative theories and extensions of the Standard Model for the elementary particle physics. Keywords: Higgs boson, BCS theory, nuclear pairing, Higgs mechanism, Standard Model.
Kellerstein, M; Verbaarschot, J J M
2016-01-01
The behavior of quenched Dirac spectra of two-dimensional lattice QCD is consistent with spontaneous chiral symmetry breaking which is forbidden according to the Coleman-Mermin-Wagner theorem. One possible resolution of this paradox is that, because of the bosonic determinant in the partially quenched partition function, the conditions of this theorem are violated allowing for spontaneous symmetry breaking in two dimensions or less. This goes back to work by Niedermaier and Seiler on nonamenable symmetries of the hyperbolic spin chain and earlier work by two of the auhtors on bosonic partition functions at nonzero chemical potential. In this talk we discuss chiral symmetry breaking for the bosonic partition function of QCD at nonzero isospin chemical potential and a bosonic random matrix theory at imaginary chemical potential and compare the results with the fermionic counterpart. In both cases the chiral symmetry group of the bosonic partition function is noncompact.
Moraes, P H R S; Correa, R A C
2016-01-01
In this work we present cosmological solutions from the simplest non-trivial $T$-dependence in $f(R,T)$ theory of gravity, with $R$ and $T$ standing for the Ricci scalar and trace of the energy-momentum tensor, respectively. Although such an approach yields a highly non-linear differential equation for the scale factor, we show that it is possible to obtain analytical solutions for the cosmological parameters. For some values of the free parameters, the model is able to predict a transition from a decelerated to an accelerated expansion of the universe.
Dirac Bracket Quantization of Bosonized chiral QCD2
We systematically derive the bosonized form of the chiral QCD2 Zagrangean exchibiting explicitely the anomalous breaking of gauge invariance and quantize it using Dirac's algorithm for constrained systems. As a side product we also discuss the Hamiltonean formalism for the principal sigma model, and derive the commutation relations of the chiral currents in both models. (author)
Pragmatics for formal semantics
Danvy, Olivier
2011-01-01
This tech talk describes how to write and how to inter-derive formal semantics for sequential programming languages. The progress reported here is (1) concrete guidelines to write each formal semantics to alleviate their proof obligations, and (2) simple calculational tools to obtain a formal sem...
Pimenta, Jean Jûnio Mendes; Belussi, Lucas Francisco Bosso; Natti, Érica Regina Takano; Natti, Paulo Laerte
2013-01-01
The Higgs boson was predicted in 1964 by British physicist Peter Higgs. The Higgs is the key to explain the origin of the mass of other elementary particles of Nature. However, only with the coming into operation of the LHC, in 2008, there were technological conditions to search for the Higgs boson. Recently, a major international effort conducted at CERN, by means of ATLAS and CMS experiments, has enabled the observation of a new bosonic particle in the region of 125 GeVs. In this paper, by ...
Photoproduction of leptophobic bosons
Fanelli, Cristiano
2016-01-01
We propose a search for photoproduction of leptophobic bosons that couple to quarks at the GlueX experiment at Jefferson Lab. We study in detail a new gauge boson that couples to baryon number $B$, and estimate that $\\gamma p \\to p B$ will provide the best sensitivity for $B$ masses above 0.5 GeV. This search will also provide sensitivity to other proposed dark-sector states that couple to quarks. Finally, our results motivate a similar search for $B$ boson electroproduction at the CLAS experiment.
Entropy current formalism for supersymmetric theories
L. Andrianopoli
2015-03-01
Full Text Available The recent developments in fluid/gravity correspondence give a new impulse to the study of fluid dynamics of supersymmetric theories. In that respect, the entropy current formalism requires some modifications in order to be adapted to supersymmetric theories and supergravities. We formulate a new entropy current in superspace with the properties: 1 it is conserved off-shell for non-dissipative fluids, 2 it is invariant under rigid supersymmetry transformations, 3 it is covariantly closed in local supersymmetric theories, 4 it reduces to its bosonic expression on space–time.
Approximate gauge symemtry of composite vector bosons
Suzuki, Mahiko
2010-06-01
It can be shown in a solvable field theory model that the couplings of the composite vector mesons made of a fermion pair approach the gauge couplings in the limit of strong binding. Although this phenomenon may appear accidental and special to the vector bosons made of a fermion pair, we extend it to the case of bosons being constituents and find that the same phenomenon occurs in more an intriguing way. The functional formalism not only facilitates computation but also provides us with a better insight into the generating mechanism of approximate gauge symmetry, in particular, how the strong binding and global current conservation conspire to generate such an approximate symmetry. Remarks are made on its possible relevance or irrelevance to electroweak and higher symmetries.
Arkhipov, Alex
2011-01-01
We motivate and prove a version of the birthday paradox for $k$ identical bosons in $n$ possible modes. If the bosons are in the uniform mixed state, also called the maximally mixed quantum state, then we need $k \\sim \\sqrt{n}$ bosons to expect two in the same state, which is smaller by a factor of $\\sqrt{2}$ than in the case of distinguishable objects (boltzmannons). While the core result is elementary, we generalize the hypothesis and strengthen the conclusion in several ways. One side result is that boltzmannons with a randomly chosen multinomial distribution have the same birthday statistics as bosons. This last result is interesting as a quantum proof of a classical probability theorem; we also give a classical proof.
Barkhofen, Sonja; Bartley, Tim J.; Sansoni, Linda; Kruse, Regina; Hamilton, Craig S.; Jex, Igor; Silberhorn, Christine
2016-01-01
Sampling the distribution of bosons that have undergone a random unitary evolution is strongly believed to be a computationally hard problem. Key to outperforming classical simulations of this task is to increase both the number of input photons and the size of the network. We propose driven boson sampling, in which photons are input within the network itself, as a means to approach this goal. When using heralded single-photon sources based on parametric down-conversion, this approach offers ...
Stefania Pandolfi
2016-01-01
CERN celebrated the fourth anniversary of the historical Higgs boson announcement with special pizzas. 400 pizzas were served on Higgs pizza day in Restaurant 1 at CERN to celebrate the fourth anniversary of the announcement of the discovery of the Higgs Boson (Image: Maximilien Brice/ CERN) What do the Higgs boson and a pizza have in common? Pierluigi Paolucci, INFN and CMS collaboration member, together with INFN president Fernando Ferroni found out the answer one day in Naples: the pizza in front of them looked exactly like a Higgs boson event display. A special recipe was then created in collaboration with the chef of the historic “Ettore” pizzeria in the St. Lucia area of Naples, and two pizzas were designed to resemble two Higgs boson decay channel event displays. The “Higgs Boson Pizza Day” was held on Monday, 4 July 2016, on the fourth anniversary of the announcement of the discovery of the Higgs boso...
Cinzia De Melis
2016-01-01
Four years after the historic announcement of the Higgs boson discovery at CERN, a collaboration between INFN and CERN has declared 4 July 2016 as “Higgs Boson Pizza Day”. The idea was born in Naples, by Pierluigi Paolucci and INFN president Fernando Ferroni, who inspired the chef of the historic “Ettore” pizzeria in St. Lucia to create the Higgs boson pizza in time for the opening of a Art&Science exhibition on 15 September 2015 in Naples. The animation shows the culinary creation of a Higgs boson in form of a vegetarian and ham&salami pizza. Ham&Salami: A two asparagus (proton-proton) collision produces a spicy Higgs boson (chorizo) decaying into two high-energy salami (photon) clusters and a lot of charged (sliced ham) and neutral (olive) particles that are detected in the pizza (detector) entirely covered with mozzarella sensors. A two asparagus (proton-proton) collision produces a juicy Higgs boson (cherry tomato) decaying into four high-energy (charged) peppers producing a tasty sign...
Industrial use of formal methods formal verification
Boulanger, Jean-Louis
2012-01-01
At present the literature gives students and researchers of the very general books on the formal technics. The purpose of this book is to present in a single book, a return of experience on the used of the "formal technics" (such proof and model-checking) on industrial examples for the transportation domain. This book is based on the experience of people which are completely involved in the realization and the evaluation of safety critical system software based. The implication of the industrialists allows to raise the problems of confidentiality which could appear and so allow
Magnetoresistance and localization in bosonic insulators
Müller, Markus
2013-06-01
We study the strong localization of hard-core bosons. Using a locator expansion we find that in the insulator, unlike for typical fermion problems, nearly all low-energy scattering paths come with positive amplitudes and hence interfere constructively. As a consequence, the localization length of bosonic excitations shrinks when the constructive interference is suppressed by a magnetic field, entailing an exponentially large positive magnetoresistance, opposite to and significantly stronger than the analogous effect in fermions. Within the forward-scattering approximation, we find that the lowest-energy excitations are the most delocalized. A similar analysis applied to random field Ising models suggests that the ordering transition is due to a delocalization initiated at zero energy rather than due to the closure of a mobility gap in the paramagnet.
Computing matrix permanent with collective boson operators
Huh, Joonsuk
2016-01-01
Computing permanents of matrices are known to be a classically hard problem that the computational cost grows exponentially with the size of the matrix increases. So far, there exist a few classical algorithms to compute the matrix permanents in deterministic and in randomized ways. By exploiting the series expansion of products of boson operators regarding collective boson operators, a generalized algorithm for computing permanents is developed that the algorithm can handle the arbitrary matrices with repeated columns and rows. In a particular case, the formula is reduced to Glynn's form. Not only the algorithm can be used for a deterministic direct calculation of the matrix permanent but also can be expressed as a sampling problem like Gurvits's randomized algorithm.
Hales, Thomas C.
2014-01-01
This report describes three particular technological advances in formal proofs. The HOL Light proof assistant will be used to illustrate the design of a highly reliable system. Today, proof assistants can verify large bodies of advanced mathematics; and as an example, we turn to the formal proof in Coq of the Feit-Thompson Odd Order theorem in group theory. Finally, we discuss advances in the automation of formal proofs, as implemented in proof assistants such as Mizar, Coq, Isabelle, and HOL...
Bosonic behavior of entangled fermions
Two bound, entangled fermions form a composite boson, which can be treated as an elementary boson as long as the Pauli principle remains irrelevant. The bosonic character of the composite is intimately linked to the entanglement of the fermions: Large entanglement implies good bosonic properties. The deviation from perfect bosonic behavior manifests itself in the statistical properties of the composites and in their collective interference. As a consequence, the counting statistics exhibited by composites allow one to infer the form of the two-fermion wave-function. Bosonic behavior can thus be used as a probe for the underlying structure of composite particles without directly accessing their constituents.
Thermal expansion of fuel pellet is an important property which limits the lifetime of the fuels in reactors, because it affects both the pellet and cladding mechanical interaction and the gap conductivity. By fitting a number of available measured data, recommended equations have been presented and successfully used to estimate thermal expansion coefficient of the nuclear fuel pellet. However, due to large scatter of the measured data, non-consensus data have been omitted in formulating the equations. Also, the equation is strongly governed by the lack of appropriate experimental data. For those reasons, it is important to develop theoretical methodologies to better describe thermal expansion behaviour of nuclear fuel. In particular, first-principles and molecular dynamics simulations have been certainly contributed to predict reliable thermal expansion without fitting the measured data. Furthermore, the two theoretical techniques have improved on understanding the change of fuel dimension by describing the atomic-scale processes associated with lattice expansion in the fuels. (author)
Anyons in the operational formalism
The operational formalism to quantum mechanics seeks to base the theory on a firm foundation of physically well-motivated axioms [1]. It has succeeded in deriving the Feynman rules [2] for general quantum systems. Additional elaborations have applied the same logic to the question of identical particles, confirming the so-called Symmetrization Postulate [3]: that the only two options available are fermions and bosons [4, 5]. However, this seems to run counter to results in two-dimensional systems, which allow for anyons, particles with statistics which interpolate between Fermi-Dirac and Bose-Einstein (see [6] for a review). In this talk we will show that the results in two dimensions can be made compatible with the operational results. That is, we will show that anyonic behavior is a result of the topology of the space in two dimensions [7], and does not depend on the particles being identical; but that nevertheless, if the particles are identical, the resulting system is still anyonic
Operator bosonization on Riemann surfaces: new vertex operators
A new formalism is presented for building an operator theory of generalized ghost systems (bc theories of spin J) on Riemann surfaces (loop diagrams of the closed string theory). Operators of the bc system are expressed through the operators of a bosonic conformal theory on a Riemann surface. As distinct from standard bosonization formulas, which have meaning only locally, the Baker-Akhiezer operator functions are introduced which are globally well defined on a Riemann surface of arbitrary form. The operator algebra of Baker-Akhiezer functions generates explicity the algebraic-geometrical τ function and correlation functions of bc systems on Riemann surfaces
A combinatorial construction of symplectic expansions
Kuno, Yusuke
2010-01-01
The notion of a symplectic expansion directly relates the topology of a surface to formal symplectic geometry. We give a method to construct a symplectic expansion by solving a recurrence formula given in terms of the Baker-Campbell-Hausdorff series.
Software Formal Inspections Guidebook
1993-01-01
The Software Formal Inspections Guidebook is designed to support the inspection process of software developed by and for NASA. This document provides information on how to implement a recommended and proven method for conducting formal inspections of NASA software. This Guidebook is a companion document to NASA Standard 2202-93, Software Formal Inspections Standard, approved April 1993, which provides the rules, procedures, and specific requirements for conducting software formal inspections. Application of the Formal Inspections Standard is optional to NASA program or project management. In cases where program or project management decide to use the formal inspections method, this Guidebook provides additional information on how to establish and implement the process. The goal of the formal inspections process as documented in the above-mentioned Standard and this Guidebook is to provide a framework and model for an inspection process that will enable the detection and elimination of defects as early as possible in the software life cycle. An ancillary aspect of the formal inspection process incorporates the collection and analysis of inspection data to effect continual improvement in the inspection process and the quality of the software subjected to the process.
Hanna, Gila
1989-01-01
The origins of the emphasis on formal proof are discussed as well as more recent views. Factors in acceptance of a proof and the social process of acceptance by mathematicians are included. The impact of formal proof on the curriculum and implications for teaching are given. (DC)
Marino, Eduardo
The electron, discovered by Thomson by the end of the nineteenth century, was the first experimentally observed particle. The Weyl fermion, though theoretically predicted since a long time, was observed in a condensed matter environment in an experiment reported only a few weeks ago. Is there any linking thread connecting the first and the last observed fermion (quasi)particles? The answer is positive. By generalizing the method known as bosonization, the first time in its full complete form, for a spacetime with 3+1 dimensions, we are able to show that both electrons and Weyl fermions can be expressed in terms of the same boson field, namely the Kalb-Ramond anti-symmetric tensor gauge field. The bosonized form of the Weyl chiral currents lead to the angle-dependent magneto-conductance behavior observed in these systems.
Liebling, Steven L
2012-01-01
The idea of stable, localized bundles of energy has strong appeal as a model for particles. In the 1950s John Wheeler envisioned such bundles as smooth configurations of electromagnetic energy that he called {\\em geons}, but none were found. Instead, particle-like solutions were found in the late 1960s with the addition of a scalar field, and these were given the name {\\em boson stars}. Since then, boson stars find use in a wide variety of models as sources of dark matter, as black hole mimickers, in simple models of binary systems, and as a tool in finding black holes in higher dimensions with only a single killing vector. We discuss important varieties of boson stars, their dynamic properties, and some of their uses, concentrating on recent efforts.
Steven L. Liebling
2012-05-01
Full Text Available The idea of stable, localized bundles of energy has strong appeal as a model for particles. In the 1950s, John Wheeler envisioned such bundles as smooth configurations of electromagnetic energy that he called geons, but none were found. Instead, particle-like solutions were found in the late 1960s with the addition of a scalar field, and these were given the name boson stars. Since then, boson stars find use in a wide variety of models as sources of dark matter, as black hole mimickers, in simple models of binary systems, and as a tool in finding black holes in higher dimensions with only a single Killing vector. We discuss important varieties of boson stars, their dynamic properties, and some of their uses, concentrating on recent efforts.
Tsekov, R
2016-01-01
Thermodynamically, bosons and fermions differ by their statistics only. A general entropy functional is proposed by superposition of entropic terms, typical for different quantum gases. The statistical properties of the corresponding Janus particles are derived by variation of the weight of the boson/fermion fraction. It is shown that di-bosons and anti-fermions separate in gas and liquid phases, while three-phase equilibrium appears for poly-boson/fermion Janus particles.
We study the phenomenology of Higgs bosons close to 126 GeV within the scale invariant unconstrained Next-to-Minimal Supersymmetric Standard Model (NMSSM), focusing on the regions of parameter space favoured by low fine-tuning considerations, namely stop masses of order 400 GeV to 1 TeV and an effective μ parameter between 100–200 GeV, with large (but perturbative) λ and low tanβ=2–4. We perform scans over the above parameter space, focusing on the observable Higgs cross sections into γγ, WW, ZZ, bb, ττ final states, and study the correlations between these observables. We show that the γγ signal strength may be enhanced up to a factor of about two not only due to the effect of singlet–doublet mixing, which occurs more often when the 126 GeV Higgs boson is the next-to-lightest CP-even one, but also due to light stops (and to a lesser extent light chargino and charged Higgs loops). There may be also smaller enhancements in the Higgs decay channels into WW, ZZ, correlated with the γγ enhancement. However there is no such correlation observed involving the Higgs decay channels into bb, ττ. The requirement of having perturbative couplings up to the GUT scale favours the interpretation of the 126 GeV Higgs boson as being the second lightest NMSSM CP-even state, which can decay into pairs of lighter neutralinos, CP-even or CP-odd Higgs bosons, leading to characteristic signatures of the NMSSM. In a non-negligible part of the parameter range the increase in the γγ rate is due to the superposition of rates from nearly degenerate Higgs bosons. Resolving these Higgs bosons would rule out the Standard Model, and provide evidence for the NMSSM
Anomalous gauge boson interactions
We discuss the direct measurement of the trilinear vector boson couplings in present and future collider experiments. The major goals of such experiments will be the confirmation of the Standard Model (SM) predictions and the search for signals of new physics. We review our current theoretical understanding of anomalous trilinear gauge-boson self interactions. If the energy scale of the new physics is ∼ 1 TeV, these low energy anomalous couplings are expected to be no larger than Ο(10-2). Constraints from high precision measurements at LEP and low energy charged and neutral current processes are critically reviewed
This is the summary report of the Higgs Boson Working Group. We discuss a variety of search techniques for a Higgs boson which is lighter than the Z. The processes K → πH, η prime → ηH,Υ → Hγ and e+e- → ZH are examined with particular attention paid to theoretical uncertainties in the calculations. We also briefly examine new features of Higgs phenomenology in a model which contains Higgs triplets as well as the usual doublet of scalar fields. 33 refs., 6 figs., 1 tab
Nonexotic Neutral Gauge Bosons
Appelquist, Thomas; Dobrescu, Bogdan A.; Hopper, Adam R.
2002-01-01
We study theoretical and experimental constraints on electroweak theories including a new color-singlet and electrically-neutral gauge boson. We first note that the electric charges of the observed fermions imply that any such Z' boson may be described by a gauge theory in which the Abelian gauge groups are the usual hypercharge along with another U(1) component in a kinetic-diagonal basis. Assuming that the observed quarks and leptons have generation-independent U(1) charges, and that no new...
This paper is the summary report of the Higgs Boson Working Group. The authors discuss a variety of search techniques for a Higgs boson which is lighter than the Z. The processes K → πH, η' → ηH, Υ → Hγ and e+e- → ZH are examined with particular attention paid to theoretical uncertainties in the calculations. The authors also briefly examine new features of Higgs phenomenology in a model which contains Higgs triplets as well as the usual doublet of scalar fields
Bosonic variables in nuclear matters
It is shown that the boson theoretical interpretation of nuclear forces nessecitates the introduction of bosonic variables within the state function of nuclear matter. In this framework the 2-boson exchange plays a decisive role and calls for the introduction of special selfenergy diagrams. This generalized scheme is discussed with the help of a solvable field theoretical model. (orig.)
A computer package for IBM-2 in the F-spin formalism
A computer package for the neutron-proton interacting boson model is presented. It used the F-spin symmetric U(5) limit wavefunction as its basis states. Hamiltonian and other operators are written in terms of F-spin tonsorial form. In the input, in addition to the Hamiltonian forms in terms of neutron and proton bosons indices, F-spin tensorial formalism is also provided. B(M1) and B(E2) can also be calculated in the package
Intermediate mass Higgs boson(s)
Finding and understanding the spectrum of scalar bosons is the central problem of particle physics today. Considerable work has been done to learn how to study Standard Model heavy and obese Higgs bosons; simulations including the problems induced by standard model backgrounds are underway, and some results are reported elsewhere in these proceedings. The mass region MH Z/2 will be covered at SLC and LEP. LEPII will be able to extend this range to about 85 GeV. Above MH > 2MZ the search is easy for a Standard Model H degree at the SSC, though not so simple for the neutral scalars of a supersymmetric theory. The intermediate region, MZ/2 ≤ MH ≤ 2MZ is one of the most difficult mass regions to study, and it is the subject of this report. The authors concentrate on a neutral Standard Model scalar to be specific. The lightest scalar of a supersymmetric theory behaves very much like a Standard Model scalar for most ranges of parameters, so the results generally apply to that case as well, and for any form the scalar spectrum might take our results indicate how the analysis might go. Ultimately, to fully understand spontaneous symmetry breaking and the origin of mass, it will be necessary to find any intermediate mass scalar and to know in what mass ranges no scalars exist. Their analysis is only in progress, and their results reported here must be regarded as tentative
Nonequilibrium functional bosonization of quantum wire networks
Ngo Dinh, Stephane, E-mail: stephane.ngodinh@kit.edu [Institut fuer Theorie der Kondensierten Materie, Karlsruhe Institute of Technology, 76128 Karlsruhe (Germany); DFG Center for Functional Nanostructures, Karlsruhe Institute of Technology, 76128 Karlsruhe (Germany); Bagrets, Dmitry A. [Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany); Mirlin, Alexander D. [Institut fuer Theorie der Kondensierten Materie, Karlsruhe Institute of Technology, 76128 Karlsruhe (Germany); Institut fuer Nanotechnologie, Karlsruhe Institute of Technology, 76021 Karlsruhe (Germany); DFG Center for Functional Nanostructures, Karlsruhe Institute of Technology, 76128 Karlsruhe (Germany); Petersburg Nuclear Physics Institute, 188300 St. Petersburg (Russian Federation)
2012-11-15
We develop a general approach to nonequilibrium nanostructures formed by one-dimensional channels coupled by tunnel junctions and/or by impurity scattering. The formalism is based on nonequilibrium version of functional bosonization. A central role in this approach is played by the Keldysh action that has a form reminiscent of the theory of full counting statistics. To proceed with evaluation of physical observables, we assume the weak-tunneling regime and develop a real-time instanton method. A detailed exposition of the formalism is supplemented by two important applications: (i) tunneling into a biased Luttinger liquid with an impurity, and (ii) quantum Hall Fabry-Perot interferometry. - Highlights: Black-Right-Pointing-Pointer A nonequilibrium functional bosonization framework for quantum wire networks is developed Black-Right-Pointing-Pointer For the study of observables in the weak tunneling regime a real-time instanton method is elaborated. Black-Right-Pointing-Pointer We consider tunneling into a biased Luttinger liquid with an impurity. Black-Right-Pointing-Pointer We analyze electronic Fabry-Perot interferometers in the integer quantum Hall regime.
Renyi entropies of free bosons on the torus and holography
Datta, Shouvik
2014-01-01
We analytically evaluate the Renyi entropies for the two dimensional free boson CFT. The CFT is considered to be compactified on a circle and at finite temperature. The Renyi entropies S_n are evaluated for a single interval using the two point function of bosonic twist fields on a torus. For the case of the compact boson, the sum over the classical saddle points results in the Riemann-Siegel theta function associated with the A_{n-1} lattice. We then study the Renyi entropies in the decompactification regime. We show that in the limit when the size of the interval becomes the size of the spatial circle, the entanglement entropy reduces to the thermal entropy of free bosons on a circle. We then set up a systematic high temperature expansion of the Renyi entropies and evaluate the finite size corrections for free bosons. Finally we compare these finite size corrections both for the free boson CFT and the free fermion CFT with the one-loop corrections obtained from bulk three dimensional handlebody spacetimes w...
We investigate the phase diagram of correlated lattice bosons using the bosonic dynamical mean field theory (BDMFT). The BDMFT, formulated by Byczuk and Vollhardt (Phys. Rev. B 77, 235106 (2008)), is a comprehensive and thermodynamically consistent approximation in which the normal and condensed bosons are treated on equal footing. Within BDMFT the lattice bosonic problem is replaced by a single impurity coupled to two bosonic baths (corresponding to normal and condensed bosons, respectively). The resulting set of equations, the so-called ''impurity problem'', has to be solved self-consistently. Our approach is the strong coupling expansion within which the phase transition between the Mott-insulating superfluid phases can be described. Different thermodynamical quantities (particle density, compressibility, order parameter) as well as the bosonic density of states are investigated across the transition line.
Rand, John; Torm, Nina Elisabeth
2012-01-01
Based on unique panel data consisting of both formal and informal firms, this paper uses a matched double difference approach to examine the relationship between legal status and firm level outcomes in micro, small and medium manufacturing enterprises (SMEs) in Vietnam. Controlling for determining...... factors and observable time-variant factors that may simultaneously influence the decision to formalize and subsequent firm performance, we find evidence that becoming officially registered leads to an increase in profits and investments, and a decrease in the use of casual labor (improved contract...... conditions for workers). Thus, we conclude that formalizing is beneficial both to firms and the workers in these firms....
Towards the Fradkin-Vasiliev formalism in three dimensions
Zinoviev, Yu M
2016-01-01
In this paper we show that using frame-like gauge invariant formulation for the massive bosonic and fermionic fields in three dimensions the free Lagrangians for these fields can be rewritten in the explicitly gauge invariant form in terms of the appropriately chosen set of gauge invariant objects. This in turn opens the possibility to apply the Fradkin-Vasiliev formalism to the investigation of possible interactions of such fields.
Jora, Renata
2009-01-01
We propose an electroweak model based on the identification of the Higgs with the dilaton. We show that it is possible in this context to have a massless Higgs boson at tree and one loop levels without contradicting the main experimental and theoretical constraints.
AUTHOR|(CDS)2077480; Müller, Katharina; Anderson, Jonathan
In this thesis several measurements of the $Z$ boson production cross section in the LHCb detector are presented. After an introduction with the description of the underlying theory; the detector and the properties of the collisions the machine provided to us in LHC run I in Chapter 1, in Chapter 2 the details of the $Z$ reconstruction in the $Z\\rightarrow\\mu^+\\mu^-$ final state is discussed. In Chapter 3 jets are added to the $Z$ bosons. Several aspects of jet reconstruction are presented and a cross section measurement for the associated production of $Z$ bosons with jets at $\\sqrt{s}=7$ TeV is presented for two transverse momentum thresholds of the jets. In Chapter 4 the capability of the LHCb detector to reconstruct charmed mesons is used to establish a $ZD^{0}$ and a $ZD^{+}$ signal and to measure the total cross section. In Chapter 5 the cross section of inclusive $Z$ boson production is measured at a low statistics sample of $3.3~\\text{pb}^{-1}$ at $\\sqrt{s}=2.76$ TeV.
Formal languages and compilation
Reghizzi, Stefano Crespi
2009-01-01
Covers the fundamental concepts of formal languages and compilation, which are central to computer science and based on well-consolidated principles. Based on definitions and algorithms, this book focuses on the importance of combining theoretical concepts with practical applications.
Anisotropic expansion of a thermal dipolar Bose gas
Tang, Yijun; Burdick, Nathaniel Q; DiSciacca, Jack M; Petrov, Dmitry S; Lev, Benjamin L
2016-01-01
We report on the anisotropic expansion of ultracold bosonic dysprosium gases at temperatures above quantum degeneracy and develop a quantitative theory to describe this behavior. The theory expresses the post-expansion aspect ratio in terms of temperature and microscopic collisional properties by incorporating Hartree-Fock mean-field interactions, hydrodynamic effects, and Bose-enhancement factors. Our results extend the utility of expansion imaging by providing accurate thermometry for dipolar thermal Bose gases, reducing error in expansion thermometry from tens of percent to only a few percent. Furthermore, we present a simple method to determine scattering lengths in dipolar gases, including near a Feshbach resonance, through observation of thermal gas expansion.
Long Range Correlation in Higgs Boson Plus Two Jets Production at the LHC
Sun, Peng; Yuan, Feng
2016-01-01
We study Higgs boson plus two high energy jets production at the LHC in the kinematics where the two jets are well separated in rapidity. The partonic processes are dominated by the t-channel weak boson fusion (WBF) and gluon fusion (GF) contributions. We derive the associated QCD resummation formalism for the correlation analysis where the total transverse momentum q_\\perp of the Higgs boson and two jets is small. Because of different color structures, the resummation results lead to distinguished behaviors: the WBF contribution peaks at relative low q_\\perp while all GF channel contributions are strongly de-correlated and spread to a much wider q_\\perp range. By applying a kinematic cut on q_\\perp, one can effectively increase the WBF signal to the GF background by a significant factor. This greatly strengthens the ability to investigate the WBF channel in Higgs boson production and study the couplings of Higgs to electroweak bosons.
Scattering of stringy states in compactified closed bosonic string
Maharana, Jnanadeva
2015-07-01
We present scattering of stringy states of closed bosonic string compactified on torus Td. We focus our attention on scattering of moduli and gauge bosons. These states appear when massless excitations such as graviton and antisymmetric tensor field of the uncompactified theory are dimensionally reduced to lower dimension. The toroidally compactified theory is endowed with the T-duality symmetry, O (d, d). Therefore, it is expected that the amplitude for scattering of such states will be T-duality invariant. The formalism of Kawai-Lewellen-Tye is adopted and appropriately tailored to construct the vertex operators of moduli and gauge bosons. It is shown, in our approach, that N-point amplitude is T-duality invariant. We present illustrative examples for the four point amplitude to explicitly demonstrate the economy of our formalism when three spatial dimensions are compactified on T3. It is also shown that if we construct an amplitude with a set of 'initial' backgrounds, the T-duality operation transforms it to an amplitude associated with another set backgrounds. We propose a modified version of KLT approach to construct vertex operators for nonabelian massless gauge bosons which appear in certain compactification schemes.
Scattering of stringy states in compactified closed bosonic string
Jnanadeva Maharana
2015-07-01
Full Text Available We present scattering of stringy states of closed bosonic string compactified on torus Td. We focus our attention on scattering of moduli and gauge bosons. These states appear when massless excitations such as graviton and antisymmetric tensor field of the uncompactified theory are dimensionally reduced to lower dimension. The toroidally compactified theory is endowed with the T-duality symmetry, O(d,d. Therefore, it is expected that the amplitude for scattering of such states will be T-duality invariant. The formalism of Kawai–Lewellen–Tye is adopted and appropriately tailored to construct the vertex operators of moduli and gauge bosons. It is shown, in our approach, that N-point amplitude is T-duality invariant. We present illustrative examples for the four point amplitude to explicitly demonstrate the economy of our formalism when three spatial dimensions are compactified on T3. It is also shown that if we construct an amplitude with a set of ‘initial’ backgrounds, the T-duality operation transforms it to an amplitude associated with another set backgrounds. We propose a modified version of KLT approach to construct vertex operators for nonabelian massless gauge bosons which appear in certain compactification schemes.
The Parametrized Post-Newtonian-Vainshteinian Formalism
Avilez-Lopez, Ana; Saffin, Paul M; Skordis, Constantinos
2015-01-01
Light degrees of freedom that modify gravity on cosmological scales must be "screened" on solar system scales in order to be compatible with data. The Vainshtein mechanism achieves this through a breakdown of classical perturbation theory, as large interactions involving new degrees of freedom become important below the so-called Vainshtein radius. We begin to develop an extension of the Parameterized Post-Newtonian (PPN) formalism that is able to handle Vainshteinian corrections. We argue that theories with a unique Vainshtein scale must be expanded using two small parameters. In this Parameterized Post-Newtonian-Vainshteinian (PPNV) expansion, the primary expansion parameter that controls the PPN order is, as usual, the velocity $v$. The secondary expansion parameter, $\\alpha$, controls the strength of the Vainshteinian correction and is a theory-specific combination of the Schwarzschild radius and the Vainshtein radius of the source that is independent of its mass. We present the general framework and appl...
Spring, Justin B; Humphreys, Peter C; Kolthammer, W Steven; Jin, Xian-Min; Barbieri, Marco; Datta, Animesh; Thomas-Peter, Nicholas; Langford, Nathan K; Kundys, Dmytro; Gates, James C; Smith, Brian J; Smith, Peter G R; Walmsley, Ian A
2013-01-01
While universal quantum computers ideally solve problems such as factoring integers exponentially more efficiently than classical machines, the formidable challenges in building such devices motivate the demonstration of simpler, problem-specific algorithms that still promise a quantum speedup. We construct a quantum boson sampling machine (QBSM) to sample the output distribution resulting from the nonclassical interference of photons in an integrated photonic circuit, a problem thought to be exponentially hard to solve classically. Unlike universal quantum computation, boson sampling merely requires indistinguishable photons, linear state evolution, and detectors. We benchmark our QBSM with three and four photons and analyze sources of sampling inaccuracy. Our studies pave the way to larger devices that could offer the first definitive quantum-enhanced computation.
Interacting boson approximation
Lectures notes on the Interacting Boson Approximation are given. Topics include: angular momentum tensors; properties of T/sub i//sup (n)/ matrices; T/sub i//sup (n)/ matrices as Clebsch-Gordan coefficients; construction of higher rank tensors; normalization: trace of products of two s-rank tensors; completeness relation; algebra of U(N); eigenvalue of the quadratic Casimir operator for U(3); general result for U(N); angular momentum content of U(3) representation; p-Boson model; Hamiltonian; quadrupole transitions; S,P Boson model; expectation value of dipole operator; S-D model: U(6); quadratic Casimir operator; an O(5) subgroup; an O(6) subgroup; properties of O(5) representations; quadratic Casimir operator; quadratic Casimir operator for U(6); decomposition via SU(5) chain; a special O(3) decomposition of SU(3); useful identities; a useful property of D/sub αβγ/(α,β,γ = 4-8) as coupling coefficients; explicit construction of T/sub x//sup (2)/ and d/sub αβγ/; D-coefficients; eigenstates of T3; and summary of T = 2 states
du Gay, Paul; Lopdrup-Hjorth, Thomas
could either be done under the headline ‘Gov 2.0’ that re-envisions the function of government as a platform around which creative citizens collaborate (O’Reilly, 2009), or by adopting a whole new mindset where a organo-centric view of the world is replaced by a more democratic, co-creative, ecosystem...... manifestation in relation to recent and ongoing reforms of organizational life and state administration. At the same time, we seek to indicate the continuing constitutive significance of formality and formalization for both the securing of organizational purposes and the individual freedom, and for ‘stateness...
Dobrev, Dimiter
2012-01-01
A definition of Artificial Intelligence was proposed in [1] but this definition was not absolutely formal at least because the word "Human" was used. In this paper we will formalize the definition from [1]. The biggest problem in this definition was that the level of intelligence of AI is compared to the intelligence of a human being. In order to change this we will introduce some parameters to which AI will depend. One of this parameters will be the level of intelligence and we will define o...
Bressler, Paul; Gorokhovsky, Alexander; Nest, Ryszard;
2015-01-01
The main result of the present paper is an analogue of Kontsevich formality theorem in the context of the deformation theory of gerbes. We construct an L∞L∞ deformation of the Schouten algebra of multi-vectors which controls the deformation theory of a gerbe.......The main result of the present paper is an analogue of Kontsevich formality theorem in the context of the deformation theory of gerbes. We construct an L∞L∞ deformation of the Schouten algebra of multi-vectors which controls the deformation theory of a gerbe....
Boson stars with nonminimal coupling
Marunovic, Anja
2015-01-01
Boson stars coupled to Einstein's general relativity possess some features similar to gravastars, such as the anisotropy in principal pressures and relatively large compactness ($\\mu_{max} = 0.32$). However, no matter how large the self-interaction is, the ordinary boson star cannot obtain arbitrarily large compression and as such does not represent a good black hole mimicker. When the boson star is nonminimally coupled to gravity, the resulting configurations resemble more the dark energy stars then the ordinary boson stars, with compactness significantly larger then that in ordinary boson stars (if matter is not constrained with the energy conditions). The gravitationally bound system of a boson star and a global monopole represents a good black hole mimicker.
The Lorentz anomaly via operator product expansion
The emergence of a critical dimension is one of the most striking features of string theory. One way to obtain it is by demanding closure of the Lorentz algebra in the light-cone gauge quantisation, as discovered for bosonic strings more than forty years ago. We give a detailed derivation of this classical result based on the operator product expansion on the Lorentzian world-sheet
The Lorentz anomaly via operator product expansion
Fredenhagen, Stefan, E-mail: stefan.fredenhagen@aei.mpg.de [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut Am Mühlenberg 1, 14476 Golm (Germany); Hoppe, Jens, E-mail: hoppe@kth.se; Hynek, Mariusz, E-mail: mkhynek@kth.se [Department of Mathematics, Royal Institute of Technology, KTH 100 44 Stockholm (Sweden)
2015-10-15
The emergence of a critical dimension is one of the most striking features of string theory. One way to obtain it is by demanding closure of the Lorentz algebra in the light-cone gauge quantisation, as discovered for bosonic strings more than forty years ago. We give a detailed derivation of this classical result based on the operator product expansion on the Lorentzian world-sheet.
Cosme, Jayson G.; Weiss, Christoph; Brand, Joachim
2015-01-01
We test variational quantum dynamics with the multiconfigurational time-dependent Hartree method for bosons (MCTDHB) against exact solutions for the dynamics of two attractive bosons following trap release. MCTDHB produces unphysical and qualitatively incorrect results of breathing dynamics where ballistic expansion should occur, although an analysis of participating mode functions indicates that the numerical result should be converged. Further analysis reveals that the calculations are inde...
Boson star at finite temperature
Latifah, S; Mart, T
2014-01-01
By using a simple thermodynamical method we confirm the finding of Chavanis and Harko that stable Bose-Einstein condensate stars can form. However, by using a thermodynamically consistent boson equation of state, we obtain a less massive Bose-Einstein condensate star compared to the one predicted by Chavanis and Harko. We also obtain that the maximum mass of a boson star is insensitive to the change of matter temperature. However, the mass of boson star with relatively large radius depends significantly on the temperature of the boson matter.
Bosonization and Lie Group Structure
Ha, Yuan K
2015-01-01
We introduce a concise quantum operator formula for bosonization in which the Lie group structure appears in a natural way. The connection between fermions and bosons is found to be exactly the connection between Lie group elements and the group parameters. Bosonization is an extraordinary way of expressing the equation of motion of a complex fermion field in terms of a real scalar boson in two dimensions. All the properties of the fermion field theory are known to be preserved under this remarkable transformation with substantial simplification and elucidation of the original theory, much like Lie groups can be studied by their Lie algebras.
Garsten, Christina; Nyqvist, Anette
suits’ (Nyqvist 2013), and of doing ‘ethnography by failure’ (Garsten 2013). In this paper, we explore the layers of informality and formality in our fieldwork experiences among financial investors and policy experts, and discuss how to ethnographically represent embodied fieldwork practices. How do we...
Formalization of Medical Guidelines
Peleška, Jan; Anger, Z.; Buchtela, David; Šebesta, K.; Tomečková, Marie; Veselý, Arnošt; Zvára, K.; Zvárová, Jana
2005-01-01
Roč. 1, - (2005), s. 133-141. ISSN 1801-5603 R&D Projects: GA AV ČR 1ET200300413 Institutional research plan: CEZ:AV0Z10300504 Keywords : GLIF model * formalization of guidelines * prevention of cardiovascular diseases Subject RIV: IN - Informatics, Computer Science
du Gay, Paul; Lopdrup-Hjorth, Thomas
2016-01-01
term this ‘fear of the formal’, outlining key elements of its genealogy and exploring its contemporary manifestation in relation to recent and ongoing reforms of organisational life in a range of contexts. At the same time, we seek to indicate the continuing constitutive significance of formality...
Links between the quantum Hall effect, chiral boson theories and string theory
Chiral boson theory is introduced and its relevance to the quantum Hall effect is explained. It is shown that the chiral boson theory admits mode expansions which are essentially those which appear and are made use of in bosonic string theories. This immediately leads to a way of quantizing the theory. Restrictions on various parameters appearing in the model can be imposed in a natural way. Finally, it is suggested that some of these ideas have important applications to other geometries which could give rise to new types of physical behavior. (author)
Approximate but accurate quantum dynamics from the Mori formalism: I. Nonequilibrium dynamics
Montoya-Castillo, Andrés; Reichman, David R.
2016-05-01
We present a formalism that explicitly unifies the commonly used Nakajima-Zwanzig approach for reduced density matrix dynamics with the more versatile Mori theory in the context of nonequilibrium dynamics. Employing a Dyson-type expansion to circumvent the difficulty of projected dynamics, we obtain a self-consistent equation for the memory kernel which requires only knowledge of normally evolved auxiliary kernels. To illustrate the properties of the current approach, we focus on the spin-boson model and limit our attention to the use of a simple and inexpensive quasi-classical dynamics, given by the Ehrenfest method, for the calculation of the auxiliary kernels. For the first time, we provide a detailed analysis of the dependence of the properties of the memory kernels obtained via different projection operators, namely, the thermal (Redfield-type) and population based (NIBA-type) projection operators. We further elucidate the conditions that lead to short-lived memory kernels and the regions of parameter space to which this program is best suited. Via a thorough analysis of the different closures available for the auxiliary kernels and the convergence properties of the self-consistently extracted memory kernel, we identify the mechanisms whereby the current approach leads to a significant improvement over the direct usage of standard semi- and quasi-classical dynamics.
Approximate but Accurate Quantum Dynamics from the Mori Formalism: I. Nonequilibrium Dynamics
Montoya-Castillo, Andrés
2016-01-01
We present a formalism that explicitly unifies the commonly used Nakajima-Zwanzig approach for reduced density matrix dynamics with the more versatile Mori theory in the context of nonequilibrium dynamics. Employing a Dyson-type expansion to circumvent the difficulty of projected dynamics, we obtain a self-consistent equation for the memory kernel which requires only knowledge of normally evolved auxiliary kernels. To illustrate the properties of the current approach, we focus on the spin-boson model and limit our attention to the use of a simple and inexpensive quasi-classical dynamics, given by the Ehrenfest method, for the calculation of the auxiliary kernels. For the first time, we provide a detailed analysis of the dependence of the properties of the memory kernels obtained via different projection operators, namely the thermal (Redfield-type) and population based (NIBA-type) projection operators. We further elucidate the conditions that lead to short-lived memory kernels and the regions of parameter spa...
Approximate but accurate quantum dynamics from the Mori formalism: I. Nonequilibrium dynamics.
Montoya-Castillo, Andrés; Reichman, David R
2016-05-14
We present a formalism that explicitly unifies the commonly used Nakajima-Zwanzig approach for reduced density matrix dynamics with the more versatile Mori theory in the context of nonequilibrium dynamics. Employing a Dyson-type expansion to circumvent the difficulty of projected dynamics, we obtain a self-consistent equation for the memory kernel which requires only knowledge of normally evolved auxiliary kernels. To illustrate the properties of the current approach, we focus on the spin-boson model and limit our attention to the use of a simple and inexpensive quasi-classical dynamics, given by the Ehrenfest method, for the calculation of the auxiliary kernels. For the first time, we provide a detailed analysis of the dependence of the properties of the memory kernels obtained via different projection operators, namely, the thermal (Redfield-type) and population based (NIBA-type) projection operators. We further elucidate the conditions that lead to short-lived memory kernels and the regions of parameter space to which this program is best suited. Via a thorough analysis of the different closures available for the auxiliary kernels and the convergence properties of the self-consistently extracted memory kernel, we identify the mechanisms whereby the current approach leads to a significant improvement over the direct usage of standard semi- and quasi-classical dynamics. PMID:27179468
Higher Spin Particles with Bosonic Counterpart of Supersymmetry
Fedoruk, S; Fedoruk, Sergey; Lukierski, Jerzy
2005-01-01
We propose the relativistic point particle models invariant under the bosonic counterpart of SUSY. The particles move along the world lines in four dimensional Minkowski space extended by $N$ commuting Weyl spinors. The models provide after first quantization the non--Grassmann counterpart of chiral superfields, satisfying Klein--Gordon equation. Free higher spin fields obtained by expansions of such chiral superfields satisfy the N=2 Bargman--Wigner equations in massive case and Fierz--Pauli equations in massless case.
Moss, Ian G
2015-01-01
The discovery of the Standard Model Higgs boson opens up a range of speculative cosmological scenarios, from the formation of structure in the early universe immediately after the big bang, to relics from the electroweak phase transition one nanosecond after the big bang, on to the end of the present-day universe through vacuum decay. Higgs physics is wide-ranging, and gives an impetus to go beyond the Standard Models of particle physics and cosmology to explore the physics of ultra-high energies and quantum gravity.
Hartmann, Betti [School of Engineering and Science, Jacobs University, Postfach 750 561, D-28725 Bremen (Germany); Kleihaus, Burkhard; Kunz, Jutta [Institut fuer Physik, Universitaet Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Schaffer, Isabell, E-mail: i.schaffer@jacobs-university.de [School of Engineering and Science, Jacobs University, Postfach 750 561, D-28725 Bremen (Germany)
2012-07-24
We consider compact boson stars that arise for a V-shaped scalar field potential. They represent a one parameter family of solutions of the scaled Einstein-Gordon equations. We analyze the physical properties of these solutions and determine their domain of existence. Along their physically relevant branch emerging from the compact Q-ball solution, their mass increases with increasing radius. Employing arguments from catastrophe theory we argue that this branch is stable, until the maximal value of the mass is reached. There the mass and size are on the order of magnitude of the Schwarzschild limit, and thus the spiraling respectively oscillating behaviour, well known for compact stars, sets in.
Lykken, Joseph D.
1996-01-01
A broad class of supersymmetric extensions of the standard model predict a Z' vector boson whose mass is naturally in the range 250 GeV < M_Z' < 2 TeV. To avoid unacceptably large mixing with the Z, one requires either a discrete tuning of the U(1)' charges or a leptophobic Z'. Both cases are likely to arise as the low energy limits of heterotic string compactifications, but a survey of existing realistic string models provides no acceptable examples. A broken U(1)' leads to additional D-term...
Robust determination of the scalar boson couplings
Corbett, Tyler; Gonzalez-Fraile, J; Gonzalez-Garcia, M C
2013-01-01
We study the indirect effects of new physics on the phenomenology of the "Higgs-like" particle. Assuming that the recently observed state belongs to a light electroweak doublet scalar and that the SU(2)_L x U(1)_Y symmetry is linearly realized, we parametrize these effects in terms of an effective Lagrangian at the electroweak scale. We choose the dimension--six operator basis which allows us to make better use of all the available data to constrain the coefficients of the dimension-six operators. We perform a global 6--parameter fit which allows simultaneous determination of the standard model scalar couplings to gluons, electroweak gauge bosons, bottom quarks, and tau leptons. The results are based on the data released at Moriond 2013. Moreover, our formalism leads to strong constraints on the electroweak triple gauge boson couplings. Note added: The analysis has been updated with a NEW GLOBAL 6-PARAMETER FIT with all the public data available after Moriond 2013. Updates of this analysis are provided at the...
Composite gauge-bosons made of fermions
Suzuki, Mahiko
2016-07-01
We construct a class of Abelian and non-Abelian local gauge theories that consist only of matter fields of fermions. The Lagrangian is local and does not contain an auxiliary vector field nor a subsidiary condition on the matter fields. It does not involve an extra dimension nor supersymmetry. This Lagrangian can be extended to non-Abelian gauge symmetry only in the case of SU(2) doublet matter fields. We carry out an explicit diagrammatic computation in the leading 1 /N order to show that massless spin-one bound states appear with the correct gauge coupling. Our diagram calculation exposes the dynamical features that cannot be seen in the formal auxiliary vector-field method. For instance, it shows that the s -wave fermion-antifermion interaction in the 3S1 channel (ψ ¯ γμψ ) alone cannot form the bound gauge bosons; the fermion-antifermion pairs must couple to the d -wave state too. One feature common to our class of Lagrangian is that the Noether current does not exist. Therefore it evades possible conflict with the no-go theorem of Weinberg and Witten on the formation of the non-Abelian gauge bosons.
Chemical graph-theoretic cluster expansions
A general computationally amenable chemico-graph-theoretic cluster expansion method is suggested as a paradigm for incorporation of chemical structure concepts in a systematic manner. The cluster expansion approach is presented in a formalism general enough to cover a variety of empirical, semiempirical, and even ab initio applications. Formally such approaches for the utilization of chemical structure-related concepts may be viewed as discrete analogues of Taylor series expansions. The efficacy of the chemical structure concepts then is simply bound up in the rate of convergence of the cluster expansions. In many empirical applications, e.g., boiling points, chromatographic separation coefficients, and biological activities, this rate of convergence has been observed to be quite rapid. More note will be made here of quantum chemical applications. Relations to questions concerning size extensivity of energies and size consistency of wave functions are addressed
Formalizations of Commonsense Psychology
Gordon, Andrew S.; Hobbs, Jerry R.
2004-01-01
The central challenge in commonsense knowledge representation research is to develop content theories that achieve a high degree of both competency and coverage. We describe a new methodology for constructing formal theories in commonsense knowledge domains that complements traditional knowledge representation approaches by first addressing issues of coverage. We show how a close examination of a very general task (strategic planning) leads to a catalog of the concepts and facts that must be ...
Sugiyama, Naonori S.; Komatsu, Eiichiro; Futamase, Toshifumi
2012-01-01
Precise understanding of nonlinear evolution of cosmological perturbations during inflation is necessary for the correct interpretation of measurements of non-Gaussian correlations in the cosmic microwave background and the large-scale structure of the universe. The "{\\delta}N formalism" is a popular and powerful technique for computing non-linear evolution of cosmological perturbations on large scales. In particular, it enables us to compute the curvature perturbation, {\\zeta}, on large scal...
The formalism necessary for the description, analysis and interpretation of experiments with oriented nuclei is considered in detail. The formalism is conveniently expressed as a sum of products where the number of terms appearing in the summation is determined by the spins of the nuclear levels and by the properties of the observed radiation. Each term of the product is identified with one particular aspect of the process which leads from the initial oriented state to the observed radiation. The orientation parameters and statistical tensors, used to describe the initial state, are discussed. The effective orientation is determined by the initial orientation modified by the deorientation coefficients. Further modifications, due to direct interactions of the electromagnetic moments of that state with the nuclear environment, are described by perturbation coefficients. The observed radiation is described by the angular distribution coefficients which depend on the multipole character of the observed radiation. Applications for various types of radiations are considered. Examples are given of angular correlation measurements, in which two radiations, e.g in a cascade, are measured in coincidence. Modifications of the standard angular distribution formalism, brought about by the finite size of the sources and detectors, are discussed. (Auth.)
Hierarchy in Sampling Gaussian-correlated Bosons
Huh, Joonsuk
2016-01-01
Boson Sampling represents a class of physical processes potentially intractable for classical devices to simulate. The Gaussian extension of Boson Sampling remains a computationally hard problem, where the input state is a product of uncorrelated Gaussian modes. Besides, motivated by molecular spectroscopy, Vibronic Boson Sampling involves operations that can generate Gaussian correlation among different Boson modes. Therefore, Gaussian Boson Sampling is a special case of Vibronic Boson Sampling. However, this does not necessarily mean that Vibronic Boson Sampling is more complex than Gaussian Boson Sampling. Here we develop a hierarchical structure to show how the initial correlation in Vibronic Boson Sampling can be absorbed in Gaussian Boson Sampling with ancillary modes and in a scattershot fashion. Since every Gaussian state is associated with a thermal state, our result implies that every sampling problem in molecular vibronic transitions, at any temperature, can be simulated by Gaussian Boson Sampling ...
A Minimally Symmetric Higgs Boson
Low, Ian
2014-01-01
Models addressing the naturalness of a light Higgs boson typically employ symmetries, either bosonic or fermionic, to stabilize the Higgs mass. We consider a setup with the minimal amount of symmetries: four shift symmetries acting on the four components of the Higgs doublet, subject to the constraints of linearly realized SU(2)xU(1) electroweak symmetry. Up to terms that explicitly violate the shift symmetries, the effective lagrangian can be derived, irrespective of the spontaneously broken group G in the ultraviolet, and is universal in all models where the Higgs arises as a pseudo-Nambu-Goldstone boson (PNGB). Very high energy scatterings of vector bosons could provide smoking gun signals of a minimally symmetric Higgs boson.
Hard-core lattice bosons: new insights from algebraic graph theory
Squires, Randall W.; Feder, David L.
2014-03-01
Determining the characteristics of hard-core lattice bosons is a problem of long-standing interest in condensed matter physics. While in one-dimensional systems the ground state can be formally obtained via a mapping to free fermions, various properties (such as correlation functions) are often difficult to calculate. In this work we discuss the application of techniques from algebraic graph theory to hard-core lattice bosons in one dimension. Graphs are natural representations of many-body Hamiltonians, with vertices representing Fock basis states and edges representing matrix elements. We prove that the graphs for hard-core bosons and non-interacting bosons have identical connectivity; the only difference is the existence of edge weights. A formal mapping between the two is therefore possible by manipulating the graph incidence matrices. We explore the implications of these insights, in particular the intriguing possibility that ground-state properties of hard-core bosons can be calculated directly from those of non-interacting bosons.
$\\delta N$ formalism from superpotential and holography
Garriga, Jaume; Vernizzi, Filippo
2016-01-01
We consider the superpotential formalism to describe the evolution of scalar fields during inflation, generalizing it to include the case with non-canonical kinetic terms. We provide a characterization of the attractor behaviour of the background evolution in terms of first and second slow-roll parameters (which need not be small). We find that the superpotential is useful in justifying the separate universe approximation from the gradient expansion, and also in computing the spectra of primordial perturbations around attractor solutions in the $\\delta N$ formalism. As an application, we consider a class of models where the background trajectories for the inflaton fields are derived from a product separable superpotential. In the perspective of the holographic inflation scenario, such models are dual to a deformed CFT boundary theory, with $D$ mutually uncorrelated deformation operators. We compute the bulk power spectra of primordial adiabatic and entropy cosmological perturbations, and show that the results...
Scattering of Stringy States in Compactified Closed Bosonic String
Maharana, Jnanaveda
2014-01-01
We present scattering of stringy states of closed bosonic string compactified on d-dimensional torus. We focus our attention on scattering of moduli and gauge bosons. These states appear when massless excitations such as graviton and antisymmetric tensor field of the uncompactified theory are dimensionally reduced to lower dimension. The toroidally compactified theory is endowed with the T-duality symmetry, O(d,d). Therefore, it is expected that the amplitude for scattering of such states will be $T$-duality invariant. The formalism of Kawai-Llewelen-Tye is adopted and appropriately tailored to construct the vertex operators of moduli and gauge bosons. It is shown, in our approach, that N-point amplitude is T-duality invariant. We present illustrative examples for the four point amplitude to explicitly demonstrate the economy of our formalism when three spatial dimensions are compactified on three dimensional torus. It is also shown that if we construct an amplitude with a set of 'initial' backgrounds, the T-...
Schüler, M.; Berakdar, J.; Pavlyukh, Y.
2016-02-01
Recent experiments access the time-resolved photoelectron signal originating from plasmon satellites in correlated materials and address their buildup and decay in real time. Motivated by these developments, we present the Kadanoff-Baym formalism for the nonequilibrium time evolution of interacting fermions and bosons. In contrast to the fermionic case, the bosons are described by second-order differential equations. Solution of the bosonic Kadanoff-Baym equations—which is the central ingredient of this work—requires substantial modification of the usual two-times electronic propagation scheme. The solution is quite general and can be applied to a number of problems, such as the interaction of electrons with quantized photons, phonons, and other bosonic excitations. Here the formalism is applied to the photoemission from a deep core hole accompanied by plasmon excitation. We compute the time-resolved photoelectron spectra and discuss the effects of intrinsic and extrinsic electron energy losses and their interference.
Constraints and period relations in bosonic strings at genus-g
Oh, C H
1994-01-01
We examine some of the implications of implementing the usual boundary conditions on the closed bosonic string in the hamiltonian framework. Using the KN formalism, it is shown that at the quantum level, the resulting constraints lead to relations among the periods of the basis 1-forms. These are compared with those of Riemanns' which arise from a different consideration.
New Results on Charged Compact Boson Stars
Kumar, Sanjeev; Kulshreshtha, Daya Shankar
2016-01-01
In this work we present some new results which we have obtained in a study of the phase diagram of charged compact boson stars in the theory involving massive complex scalar fields coupled to the U(1) gauge field and gravity in a conical potential in the presence of a cosmological constant $\\Lambda$ which we treat as a free parameter taking positive and negative values and thereby allowing us to study the theory in the de Sitter and Anti de Sitter spaces respectively. In our studies, we obtain four bifurcation points (possibility of more bifurcation points being not ruled out) in the de Sitter region. We present a detailed discussion of the various regions in our phase diagram with respect to four bifurcation points. Our theory is seen to have rich physics in a particular domain for positive values of $\\Lambda$ which is consistent with the accelerated expansion of the universe.
New results on charged compact boson stars
Kumar, Sanjeev; Kulshreshtha, Usha; Kulshreshtha, Daya Shankar
2016-05-01
In this work we present some new results that we have obtained in a study of the phase diagram of charged compact boson stars in the theory involving massive complex scalar fields coupled to the U(1) gauge field and gravity in a conical potential in the presence of a cosmological constant Λ , which we treat as a free parameter taking positive and negative values and thereby allowing us to study the theory in de Sitter and anti de Sitter spaces, respectively. We obtain four bifurcation points (the possibility of more bifurcation points not being ruled out) in the de Sitter region. We present a detailed discussion of the various regions in our phase diagram with respect to four bifurcation points. Our theory is seen to have rich physics in a particular domain for positive values of Λ , which is consistent with the accelerated expansion of the Universe.
Formalizing the concept of sound.
Kaper, H. G.; Tipei, S.
1999-08-03
The notion of formalized music implies that a musical composition can be described in mathematical terms. In this article we explore some formal aspects of music and propose a framework for an abstract approach.
Alexei Serna A.
2012-12-01
Full Text Available The application of formal methods in industry has progressed extensively over the past decade and the results are promising. But despite these achievements and it have been documented in numerous studies, it is still very common the skepticism about its usefulness and applicability. The goal of this paper is to show that its evolution over the past decade exceeds all previous processes and each time they do a better job to satisfy industrial needs. This is achieved by the description of some experiments and the result of various applications in industry and through an analyzing of the needs of companies that must be satisfy the research community in this field.
Drechsler, Rolf
2007-01-01
Preface. Contributing Authors. Introduction; R. Drechsler. 1. Formal Verification. 2. Challenges. 3. Contributions to this Book. 1: What SAT-Solvers Can and Cannot Do; E. Goldberg. 1. Introduction. 2. Hard Equivalence Checking CNF Formulas. 3. Stable Sets of Points. 2: Advancements in Mixed BDD and SAT Techniques; G. Cabodi, S. Quer. 1. Introduction. 2. Background. 3. Comparing SAT and BDD Approaches: Are they Different? 4. Decision Diagrams as a Slave Engine in General SAT: Clause Compression by Means of ZBDDs. 5. Decision Diagram Preprocessing and Circuit-Based SAT. 6. Using SAT in Symbolic
Covariant map between Ramond-Neveu-Schwarz and pure spinor formalisms for the superstring
A covariant map between the Ramond-Neveu-Schwarz (RNS) and pure spinor formalisms for the superstring is found which transforms the RNS and pure spinor BRST operators into each other. The key ingredient is a dynamical twisting of the ten spin-half RNS fermions into five spin-one and five spin-zero fermions using bosonic pure spinors that parameterize an SO(10)/U(5) coset. The map relates massless vertex operators in the two formalisms, and gives a new description of Ramond states which does not require spin fields. An argument is proposed for relating the amplitude prescriptions in the two formalisms
Formal methods in knowledge engineering.
Harmelen, van, F.; Fensel, D.
2007-01-01
This paper presents a general discussion of the role of formal methods in Knowledge Engineering. We give an historical account of the development of the field of Knowledge Engineering towards the use of formal methods. Subsequently, we discuss the pro's and cons of formal methods. We do this by summarising the proclaimed advantages, and by arguing against some of the commonly heard objections against formal methods. We briefly summarise the current state of the art and discuss the most import...
Brunet, S
2014-01-01
ATLAS Higgs poster targeted to general public, explaining the Brout-Englert-Higgs mechanism and why it is important. It also explains the role of the Higgs Boson, how we look for it, the journey of the discovery and what comes after the discovery. Also available in French (http://cds.cern.ch/record/1697501). Don’t hesitate to use it in your institute’s corridors and in your outreach events! The poster is in A0 format. You can click on the image to download the high-quality .pdf version and print it at your favorite printshop. For any questions or comments you can contact atlas-outreach-coordination@cern.ch.
The discovery of the Z boson 7 years ago verified a key prediction of the unified theory of electromagnetic and weak forces. Today an experimental program is beginning at two electron-positron colliders to study the properties of the Z particle in great detail. The data accumulated will subject the unified theory to more rigorous tests and will probe with great sensitivity for new physics not encompassed by the existing standard model of the elementary particles and forces. Questions under study include the number of quark and lepton families, the mass of the still undiscovered top quark, and the search for the still unknown fifth force of nature required by the theory to generate the masses of the elementary particles. 48 refs., 3 figs., 1 tab
He, Hong-Jian
1998-08-01
We review the recent progress in studying the anomalous electroweak quartic gauge boson couplings (QGBCs) at the LHC and the next generation high energy e±e- linear colliders (LCs). The main focus is put onto the strong electroweak symmetry breaking scenario in which the non-decoupling guarantees sizable new physics effects for the QGBCs. After commenting upon the current low energy indirect bounds and summarizing the theoretical patterns of QGBCs predicted by the typical resonance/non-resonance models, we review our systematic model-independent analysis on bounding them via WW-fusion and WWZ/ZZZ-production. The interplay of the two production mechanisms and the important role of the beam-polarization at the LCs are emphasized. The same physics may be similarly and better studied at a multi-TeV muon collider with high luminosity.
Peter J. Scott
2008-01-01
Full Text Available En este documento presentamos parte de un estudio en el que se ha analizado un proceso de aprendizaje desarrollado por estudiantes en interacción directa a través de un entorno de videoconferencia. El estudio cubre un periodo de 6 meses de interacción de un grupo de estudiantes de animación gráfica en diferentes países, quienes han llevado a cabo un total de 99 reuniones. Cada una de estas reuniones ha sido organizada y manejada por la propia comunidad de estudiantes. Al final, los integrantes de la comunidad aparecen como sus propios mentores naturales, y el grupo muestra una enorme capacidad de apoyo mutuo y de asunción de roles de facilitación mutua en el contexto de dicho intercambio. En este estudio podemos ver cómo los estudiantes pueden apoyarse mutuamente de manera eficiente en un contexto de colaboración no formal y además podemos observar cómo sistemas de videoconferencia en red pueden ayudar a facilitar y transformar una comunidad de aprendizaje, incluso sin la intervención formal de aulas o profesores.
Topological quantization of the free massive bosonic field
Arciniega, Gustavo; Patiño, Leonardo; Quevedo, Hernando
2012-01-01
We present the results of studding free massive bosonic fields under the formalism of topological quantization. First, we identify certain harmonic map as a geometric representation of this physical system. We take as a concrete example the case of free massive bosonic fields in two dimensions represented by the minimal embedding of a two dimensional surface into a pp-wave spacetime. We use this geometric representation to construct the fiber bundle corresponding to some specific field configurations and then find their topological spectra, defined as the integral of the Euler characteristic class. The integral of the Euler invariant turns out to be dependent on the order in which the variables are integrated. We discuss the results for some particular configurations and their consequences for the energy of the system.
Unintegrated parton distributions and electroweak boson production at hadron colliders
Watt, G; Ryskin, M G
2004-01-01
We describe the use of doubly-unintegrated parton distributions in hadron-hadron collisions, using the (z,k_t)-factorisation prescription where the transverse momentum of the incoming parton is generated in the last evolution step. We apply this formalism to calculate the transverse momentum (P_T) distributions of produced W and Z bosons and compare the predictions to Tevatron Run 1 data. We find that the observed P_T distributions can be generated almost entirely by the leading order q_1 q_2 -> W,Z subprocesses, using known and universal doubly-unintegrated quark distributions. We also calculate the P_T distribution of the Standard Model Higgs boson at the LHC, where the dominant production mechanism is by gluon-gluon fusion.
Radial expansion for spinning conformal blocks
Costa, Miguel$uPorto U.; Penedones, João; Trevisani, Emilio
2016-01-01
This paper develops a method to compute any bosonic conformal block as a series expansion in the optimal radial coordinate introduced by Hogervorst and Rychkov. The method reduces to the known result when the external operators are all the same scalar operator, but it allows to compute conformal blocks for external operators with spin. Moreover, we explain how to write closed form recursion relations for the coefficients of the expansions. We study three examples of four point functions in detail: one vector and three scalars; two vectors and two scalars; two spin 2 tensors and two scalars. Finally, for the case of two external vectors, we also provide a more efficient way to generate the series expansion using the analytic structure of the blocks as a function of the scaling dimension of the exchanged operator.
Sudakov Resummation in Small-x Saturation Formalism
Mueller, A. H.; Xiao, Bo-Wen; Yuan, Feng
2012-01-01
Through an explicit calculation of massive scalar particle (e.g., Higgs boson) production in high energy pA collisions up to one-loop order, we demonstrate that the Sudakov-type logarithms in hard processes in small-x saturation formalism can be systematically separated from the typical small-x logarithms. The generic feature of the Sudakov logarithms and all order resummation is derived. We further comment on the phenomenological implications and extension to other hard processes in the smal...
It was 20 years ago this month that particle physicists caught their first glimpse of the W boson. Now they have measured its mass so precisely that the Standard Model is facing an unprecedented challenge. (U.K.)
Spectroscopy of family gauge bosons
Spectroscopy of family gauge bosons is investigated based on a U(3) family gauge boson model proposed by Sumino. In his model, the family gauge bosons are in mass eigenstates in a diagonal basis of the charged lepton mass matrix. Therefore, the family numbers are defined by (e1,e2,e3)=(e,μ,τ), while the assignment for quark sector are free. For possible family-number assignments (q1,q2,q3), under a constraint from K0–K¯0 mixing, we investigate possibilities of new physics, e.g. production of the lightest family gauge boson at the LHC, μ−N→e−N, rare K and B decays, and so on.
From Bosonic Strings to Fermions
Sidharth, B. G.
2006-01-01
Early string theory described Bosonic particles at the real life Compton scale. Later developments to include Fermions initiated by Ramond and others have lead through Quantum Super Strings to M-theory operating at the as yet experimentally unattainable Planck scale. We describe an alternative route from Bosonic Strings to Fermions, by directly invoking a non commutative geometry, an approach which is closer to experiment.
Hidden order in bosonic gases confined in one-dimensional optical lattices
We analyze the effective Hamiltonian arising from a suitable power series expansion of the overlap integrals of Wannier functions for confined bosonic atoms in a one-dimensional (1D) optical lattice. For certain constraints between the coupling constants, we construct an explicit relationship between such an effective bosonic Hamiltonian and the integrable spin-S anisotropic Heisenberg model. The former results are therefore integrable by construction. The field theory is governed by an anisotropic nonlinear σ-model with singlet and triplet massive excitations; this result holds also in the generic non-integrable cases. The criticality of the bosonic system is investigated. The schematic phase diagram is drawn. Our study sheds light on the hidden symmetry of the Haldane type for 1D bosons.
Some tree-level string amplitudes in the NSR formalism
Becker, Katrin; Melnikov, Ilarion V; Robbins, Daniel; Royston, Andrew B
2015-01-01
We calculate tree level scattering amplitudes for open strings using the NSR formalism. We present a streamlined symmetry-based and pedagogical approach to the computations, which we first develop by checking two-, three-, and four-point functions involving bosons and fermions. We calculate the five-point amplitude for massless gluons and find agreement with an earlier result by Brandt, Machado and Medina. We then compute the five-point amplitudes involving two and four fermions respectively, the general form of which has not been previously obtained in the NSR formalism. The results nicely confirm expectations from the supersymmetric $F^4$ effective action. Finally we use the prescription of Kawai, Lewellen and Tye (KLT) to compute the amplitudes for the closed string sector.
Some tree-level string amplitudes in the NSR formalism
Becker, Katrin; Becker, Melanie; Melnikov, Ilarion V.; Robbins, Daniel; Royston, Andrew B.
2015-12-01
We calculate tree level scattering amplitudes for open strings using the NSR formalism. We present a streamlined symmetry-based and pedagogical approach to the computations, which we first develop by checking two-, three-, and four-point functions involving bosons and fermions. We calculate the five-point amplitude for massless gluons and find agreement with an earlier result by Brandt, Machado and Medina. We then compute the five-point amplitudes involving two and four fermions respectively, the general form of which has not been previously obtained in the NSR formalism. The results nicely confirm expectations from the supersymmetric F 4 effective action. Finally we use the prescription of Kawai, Lewellen and Tye (KLT) to compute the amplitudes for the closed string sector.
Formalization of Database Systems -- and a Formal Definition of {IMS}
Bjørner, Dines; Løvengreen, Hans Henrik
1982-01-01
Drawing upon an analogy between Programming Language Systems and Database Systems we outline the requirements that architectural specifications of database systems must futfitl, and argue that only formal, mathematical definitions may 6atisfy these. Then we illustrate home aspects and touch upon...... come ueee of formal definitions of data models and databaee management systems. A formal model of INS will carry this discussion. Finally we survey some of the exkting literature on formal definitions of database systems. The emphasis will be on constructive definitions in the denotationul semantics...
Spinor formalism and complex-vector formalism of general relativity
In this paper, using E. Cartan's exterior calculus, we give the spinor form of the structure equations, which leads naturally to the Newman--Penrose equations. Furthermore, starting from the spinor spaces and the el (2C) algebra, we construct the general complex-vector formalism of general relativity. We find that both the Cahen--Debever--Defrise complex-vector formalism and that of Brans are its special cases. Thus, the spinor formalism and the complex-vector formalism of general relativity are unified on the basis of the uni-modular group SL(2C) and its Lie algebra
Boson-exchange nucleon-nucleon potential and nuclear structure
A fully momentum-dependent one-boson-exchange potential is derived which takes into account the mesons, π, eta, sigma, rho, ω and phi. Scattering bound states and nuclear matter properties are studied in momentum space. The use of such potential is shown to be as easy as the use of more simple phenomenological interactions. In nuclear matter the formalism of Bethe-Goldstone is chosen to compute the binding energy versus density in the approximation of two-body and three-body correlations. The three-body correlated wave function obtained is then used
Analytic boosted boson discrimination
Larkoski, Andrew J.; Moult, Ian; Neill, Duff
2016-05-01
Observables which discriminate boosted topologies from massive QCD jets are of great importance for the success of the jet substructure program at the Large Hadron Collider. Such observables, while both widely and successfully used, have been studied almost exclusively with Monte Carlo simulations. In this paper we present the first all-orders factorization theorem for a two-prong discriminant based on a jet shape variable, D 2, valid for both signal and background jets. Our factorization theorem simultaneously describes the production of both collinear and soft subjets, and we introduce a novel zero-bin procedure to correctly describe the transition region between these limits. By proving an all orders factorization theorem, we enable a systematically improvable description, and allow for precision comparisons between data, Monte Carlo, and first principles QCD calculations for jet substructure observables. Using our factorization theorem, we present numerical results for the discrimination of a boosted Z boson from massive QCD background jets. We compare our results with Monte Carlo predictions which allows for a detailed understanding of the extent to which these generators accurately describe the formation of two-prong QCD jets, and informs their usage in substructure analyses. Our calculation also provides considerable insight into the discrimination power and calculability of jet substructure observables in general.
Twisted vertex algebras, bicharacter construction and boson-fermion correspondences
The boson-fermion correspondences are an important phenomena on the intersection of several areas in mathematical physics: representation theory, vertex algebras and conformal field theory, integrable systems, number theory, cohomology. Two such correspondences are well known: the types A and B (and their super extensions). As a main result of this paper we present a new boson-fermion correspondence of type D-A. Further, we define a new concept of twisted vertex algebra of order N, which generalizes super vertex algebra. We develop the bicharacter construction which we use for constructing classes of examples of twisted vertex algebras, as well as for deriving formulas for the operator product expansions, analytic continuations, and normal ordered products. By using the underlying Hopf algebra structure we prove general bicharacter formulas for the vacuum expectation values for two important groups of examples. We show that the correspondences of types B, C, and D-A are isomorphisms of twisted vertex algebras
Penrose limits versus string expansions
Blau, Matthias; Weiss, Sebastian [Institut de Physique, Universite de Neuchatel, Rue Breguet 1, CH-2000 Neuchatel (Switzerland)
2008-06-21
We analyze the relation between two a priori quite different expansions of the string equations of motion and constraints in a general curved background, namely one based on the covariant Penrose-Fermi expansion of the metric G{sub {mu}}{sub {nu}} around a Penrose limit plane wave associated with a null geodesic {gamma} and the other on the Riemann coordinate expansion in the exact metric G{sub {mu}}{sub {nu}} of the string embedding variables around the null geodesic {gamma}. Starting with the observation that there is a formal analogy between the exact string equations in a plane wave and the first-order string equations in a general background, we show that this analogy becomes exact provided that one chooses the background string configuration to be the null geodesic {gamma} itself. We then explore the higher-order correspondence between these two expansions and find that for a general curved background they agree to all orders provided that one works in Fermi coordinates and in the lightcone gauge. Requiring moreover the conformal gauge restricts one to the usual class of (Brinkmann) backgrounds admitting simultaneously the lightcone and the conformal gauge, without further restrictions.
Excited Weak Bosons and Dark Matter
Fritzsch, Harald
2016-01-01
The weak bosons are bound states of new constituents, the haplons. The p-wave excitations are studied. The state with the lowest mass is identified with the boson, which has been discovered at the LHC. Specific properties of the excited bosons are discussed, in particular their decays into weak bosons and photons. Recently a two photon signal has been observed, which might come from the decay of a neutral heavy boson with a mass of about 0.75 TeV. This particle could be the excited weak tensor boson. The stable fermion, consisting of three haplons, provides the dark matter in our universe.
Bjørner, Dines; Havelund, Klaus
2014-01-01
In this "40 years of formal methods" essay we shall first delineate, Sect. 1, what we mean by method, formal method, computer science, computing science, software engineering, and model-oriented and algebraic methods. Based on this, we shall characterize a spectrum from specification......-oriented methods to analysis-oriented methods. Then, Sect. 2, we shall provide a "survey": which are the 'prerequisite works' that have enabled formal methods, Sect. 2.1, and which are, to us, the, by now, classical 'formal methods', Sect. 2.2. We then ask ourselves the question: have formal methods for software...... development, in the sense of this paper been successful? Our answer is, regretfully, no! We motivate this answer, in Sect. 3.2, by discussing eight obstacles or hindrances to the proper integration of formal methods in university research and education as well as in industry practice. This "looking back" is...
SDG fermion-pair algebraic SO(12) and Sp(10) models and their boson realizations
Navrátil, P; Dobes, J; Dobaczewski, J
1994-01-01
It is shown how the boson mapping formalism may be applied as a useful many-body tool to solve a fermion problem. This is done in the context of generalized Ginocchio models for which we introduce S-, D-, and G-pairs of fermions and subsequently construct the sdg-boson realizations of the generalized Dyson type. The constructed SO(12) and Sp(10) fermion models are solved beyond the explicit symmetry limits. Phase transitions to rotational structures are obtained, also in situations where there is no underlying SU(3) symmetry.
SDG fermion-pair algebraic SO(12) and Sp(10) models and their boson realizations
Navratil, P.; Geyer, H. B.; Dobes, J.; Dobaczewski, J.
1994-01-01
It is shown how the boson mapping formalism may be applied as a useful many-body tool to solve a fermion problem. This is done in the context of generalized Ginocchio models for which we introduce S-, D-, and G-pairs of fermions and subsequently construct the sdg-boson realizations of the generalized Dyson type. The constructed SO(12) and Sp(10) fermion models are solved beyond the explicit symmetry limits. Phase transitions to rotational structures are obtained, also in situations where ther...
Zhu, S
2006-01-01
The $O$(MeV) spin-1 U-boson has been proposed to mediate the interaction among electron-positron and $O$(MeV) dark matter, in order to account for the 511 keV $\\gamma$-ray observation by SPI/INTEGRAL. In this paper the observability of such kind of U-boson at BESIII is investigated through the processes $e^+e^- \\to U \\gamma$ and $e^+e^- \\to J/\\Psi \\to e^+e^- U$. We find that BESIII and high luminosity B-factories have the comparable capacity to detect such U-boson. If U-boson decays mainly into dark matter, i.e. invisibly, BESIII can measure the coupling among U-boson and electron-positron $g_{eR}$ (see text) down to $O(10^{-5})$, and cover large parameter space which can account for 511 keV $\\gamma$-ray observation. On the other hand, provided that U decays mainly into electron-positron, BESIII can detect $g_{eR}$ down to $O(10^{-3})$, and it is hard to explore 511 keV $\\gamma$-ray measurement allowed parameter space due to the irreducible QED backgrounds.
Spin models and boson sampling
Garcia Ripoll, Juan Jose; Peropadre, Borja; Aspuru-Guzik, Alan
Aaronson & Arkhipov showed that predicting the measurement statistics of random linear optics circuits (i.e. boson sampling) is a classically hard problem for highly non-classical input states. A typical boson-sampling circuit requires N single photon emitters and M photodetectors, and it is a natural idea to rely on few-level systems for both tasks. Indeed, we show that 2M two-level emitters at the input and output ports of a general M-port interferometer interact via an XY-model with collective dissipation and a large number of dark states that could be used for quantum information storage. More important is the fact that, when we neglect dissipation, the resulting long-range XY spin-spin interaction is equivalent to boson sampling under the same conditions that make boson sampling efficient. This allows efficient implementations of boson sampling using quantum simulators & quantum computers. We acknowledge support from Spanish Mineco Project FIS2012-33022, CAM Research Network QUITEMAD+ and EU FP7 FET-Open Project PROMISCE.
A Z' Boson and the Higgs Boson Mass
Chanowitz, Michael S.
2008-01-01
The Standard Model fit prefers values of the Higgs boson mass that are below the 114 GeV direct lower limit from LEP II. The discrepancy is acute if the 3.2 sigma disagreement for the effective weak interaction mixing angle from the two most precise measurements is attributed to underestimated systematic error. In that case the data suggests new physics to raise the predicted value of the Higgs mass. One of the simplest possibilities is a Z' boson, which would generically increase the predict...
We consider a dilute homogeneous mixture of bosons and spin-polarized fermions at zero temperature. We first construct the formal scheme for carrying out systematic perturbation theory in terms of single particle Green's functions. We especially focus on the description of the boson-fermion interaction. To do so we need to introduce the renormalized boson-fermion T matrix, which we determine to second order in the boson-fermion s-wave scattering length. We also discuss how to incorporate the usual boson-boson T matrix in mean field approximation to obtain the total ground-state properties of the system. The next-order term beyond mean field stems from the boson-fermion interaction and is proportional to aBFkF. The total ground-state energy density to this order is the sum of the kinetic energy of the free fermions, the boson-boson mean-field interaction, the usual mean-field contribution to the boson-fermion interaction energy, and the first boson-fermion correction beyond mean field. We also compute the bosonic and the fermionic chemical potentials, the compressibilities, and the modification to the induced fermion-fermion interaction. We discuss the behavior of the total ground-state energy and the importance of the correction beyond mean field for various parameter regimes, in particular considering mixtures of 6Li and 7Li and of 3He and 4He. Moreover, we determine the modification of the induced fermion-fermion interaction due to the effects beyond mean field. We show that there is no effect on the depletion of the Bose condensate to first order in the boson-fermion scattering length aBF
Inclusion of g boson in the microscopic sdgIBM and the g boson effect
The inclusion of g boson in the microscopic sdgIBM is presented. The collectivity of g boson, the relationship between g boson properties and the strengths of the effective nucleon-nucleon interaction, and the influence of g boson on the sdIBM are discussed in detail
Medium-induced gluon radiation in hard forward parton scattering in the saturation formalism
Munier, Stéphane; Petreska, Elena
2016-01-01
We derive the medium-induced, coherent gluon radiation spectrum associated with the hard forward scattering of an energetic parton off a nucleus, in the saturation formalism and within the Gaussian approximation for the relevant correlators of Wilson lines. The calculation reproduces the simple expression for the spectrum previously obtained in the opacity expansion formalism, and rigorously specifies its validity range. The connection between the calculations in the opacity expansion and saturation formalisms is made apparent. This study may serve as a first step in order to implement consistently induced coherent energy loss and gluon shadowing in `saturation-based models' of hadron nuclear suppression in proton-nucleus collisions.
Light Front Boson Model Propagation
Jorge Henrique Sales; Alfredo Takashi Suzuki
2011-01-01
stract The scope and aim of this work is to describe the two-body interaction mediated by a particle (either the scalar or the gauge boson) within the light-front formulation. To do this, first of all we point out the importance of propagators and Green functions in Quantum Mechanics. Then we project the covariant quantum propagator onto the light front time to get the propagator for scalar particles in these coordinates. This operator propagates the wave function from x+ = 0 to x+ ＞ O. It corresponds to the definition of the time ordering operation in the light front time x+. We calculate the light-front Green's function for 2 interacting bosons propagating forward in x+. We also show how to write down the light front Green's function from the Feynman propagator and finally make a generalization to N bosons.
Hartmann, Betti, E-mail: b.hartmann@jacobs-university.de [School of Engineering and Science, Jacobs University Bremen, 28759 Bremen (Germany); Riedel, Jürgen, E-mail: j.riedel@jacobs-university.de [School of Engineering and Science, Jacobs University Bremen, 28759 Bremen (Germany); Faculty of Physics, University Oldenburg, 26111 Oldenburg (Germany); Suciu, Raluca, E-mail: r.suciu@jacobs-university.de [School of Engineering and Science, Jacobs University Bremen, 28759 Bremen (Germany)
2013-11-04
We construct boson stars in (4+1)-dimensional Gauss–Bonnet gravity. We study the properties of the solutions in dependence on the coupling constants and investigate in detail their properties. While the “thick wall” limit is independent of the value of the Gauss–Bonnet coupling, we find that the spiraling behaviour characteristic for boson stars in standard Einstein gravity disappears for large enough values of the Gauss–Bonnet coupling. Our results show that in this case the scalar field can not have arbitrarily high values of the scalar field at the center of the boson star and that it is hence impossible to reach the “thin wall” limit. Moreover, for large enough Gauss–Bonnet coupling we find a unique relation between the mass and the radius (qualitatively similar to those of neutron stars) which is not present in the Einstein gravity limit.
A Formalization of Linkage Analysis
Ingolfsdottir, Anna; Christensen, A.I.; Hansen, Jens A.;
In this report a formalization of genetic linkage analysis is introduced. Linkage analysis is a computationally hard biomathematical method, which purpose is to locate genes on the human genome. It is rooted in the new area of bioinformatics and no formalization of the method has previously been ...
Formal Verification of UML Profil
Bhutto, Arifa; Hussain, Dil Muhammad Akbar
2011-01-01
and object diagrams and behavioral view model by the activity, use case, state, and sequence diagram. However, UML does not provide the formal syntax, therefore its semantics is not formally definable, so for assure of correctness, we need to incorporate semantic reasoning through verification...
Higgs boson production at the LHC
Peters, Krisztian; The ATLAS collaboration
2015-01-01
After the discovery at the LHC, the main goal of the Higgs boson measurements at ATLAS and CMS is to fully elucidate the nature of this new particle. In this contribution we will discuss the Higgs boson production and decay properties at the LHC and the main analyses which build the fundation for the current Higgs boson property measurements. Inclusive rates as well as differential measurements in the main bosonic and fermionic channels, and searches for rarer decay modes will be presented.
Bosonic Coherent Motions in the Universe
Kim, Jihn E; Tsujikawa, Shinji
2014-01-01
We mini-review the role of fundamental spin-0 bosons as bosonic coherent motion (BCM) in the Universe. The fundamental spin-0 bosons have the potential to account for the baryon number generation, cold dark matter (CDM) via BCM, dark energy, and inflation. Among these, here we focus on the CDM possibility because it can be experimentally tested with the current experimental techniques. We also comment briefly on the panoply of the other roles of spin-0 bosons.
New procedure for departure formalities
HR & GS Departments
2011-01-01
As part of the process of simplifying procedures and rationalising administrative processes, the HR and GS Departments have introduced new personalised departure formalities on EDH. These new formalities have applied to students leaving CERN since last year and from 17 October 2011 this procedure will be extended to the following categories of CERN personnel: Staff members, Fellows and Associates. It is planned to extend this electronic procedure to the users in due course. What purpose do departure formalities serve? The departure formalities are designed to ensure that members of the personnel contact all the relevant services in order to return any necessary items (equipment, cards, keys, dosimeter, electronic equipment, books, etc.) and are aware of all the benefits to which they are entitled on termination of their contract. The new departure formalities on EDH have the advantage of tailoring the list of services that each member of the personnel must visit to suit his individual contractual and p...
Formal connections in deformation quantization
Masulli, Paolo
manifold. Gammelgaard gave an explicit formula for a class of star products in this setting. We review his construction, which is combinatorial and based on a certain family of graphs and extend it, to provide the graph formalism with the notions of composition and differentiation. We shall focus our...... attention on symplectic manifolds equipped with a family of star products, indexed by a parameter space. In this situation we can define a connection in the trivial bundle over the parameter space with fibres the formal smooth functions on the manifold, which relates the star products in the family and is...... called a formal connection. We study the question of classifying such formal connections. To each star product we can associate a certain cohomology class called the characteristic class. It turns out that a formal connection exists if and only if all the star products in the family have the same...
Vectorial versus axial goldstone bosons
The Yukawa interactions of fermions with Goldstone bosons are given in closed form for an arbitrary renormalizable field theory to all orders of perturbation theory or for a general effective Lagrangian. Although the diagonal couplings are always pseudoscalar there is an important difference between spontaneously broken vector and axial-vector global symmetries. Compared to the axial case, the diagonal douplings of 'vectorial' Goldstone bosons to charged fermions are suppressed by mixing angles or appear only via radiative corrections involving gauge fields. This general result may be relevant for the problem of flavour symmetry breaking in composite models. (Author)
Boson stars in the centre of galaxies?
Schunck, Franz E
2008-01-01
We investigate the possible gravitational redshift values for boson stars with a self-interaction, studying a wide range of possible masses. We find a limiting value of z_lim \\simeq 0.687 for stable boson star configurations. We can exclude the direct observation of boson stars. X-ray spectroscopy is perhaps the most interesting possibility.
A generalization of boson normal ordering
In this Letter we define generalizations of boson normal ordering. These are based on the number of contractions whose vertices are next to each other in the linear representation of the boson operator function. Our main motivation is to shed further light onto the combinatorics arising from algebraic and Fock space properties of boson operators
Introduction to the physics of Higgs bosons
Dawson, S.
1994-11-01
A basic introduction to the physics of the Standard Model Higgs boson is given. We discuss Higgs boson production in e{sup +}e{sup {minus}} and hadronic collisions and survey search techniques at future accelerators. The Higgs bosons of the minimal SUSY model are briefly considered. Indirect limits from triviality arguments, vacuum stability and precision measurements at LEP are also presented.
Charged Higgs Bosons in the LHCHXSWG
Heinemeyer, S
2014-01-01
Searches for charged Higgs bosons are an integral part of current and future investigations at the LHC. The LHC Higgs Cross Section Working Group (LHCHXSWG) was created to provide cross sections, branching ratios, analysis strategies etc. for Higgs boson searches at the LHC. We briefly review progress and results for charged Higgs bosons in and for the LHCHXSWG.
Introduction to the physics of Higgs bosons
A basic introduction to the physics of the Standard Model Higgs boson is given. We discuss Higgs boson production in e+e- and hadronic collisions and survey search techniques at future accelerators. The Higgs bosons of the minimal SUSY model are briefly considered. Indirect limits from triviality arguments, vacuum stability and precision measurements at LEP are also presented
Twisted bosonization in two dimensional noncommutative spacetime
Haque, Asrarul
2012-01-01
We study the twisted bosonization of massive Thirring model to relate to sine-Gordon model in Moyal spacetime using twisted commutation relations. We obtain the relevant twisted bosonization rules. We show that there exists dual rela- tionship between twisted bosonic and fermionic operators. The strong-weak duality is also observed to be preserved as its commutative counterpart.
Exploring the spectrum of regularized bosonic string theory
We implement a UV regularization of the bosonic string by truncating its mode expansion and keeping the regularized theory “as diffeomorphism invariant as possible.” We compute the regularized determinant of the 2d Laplacian for the closed string winding around a compact dimension, obtaining the effective action in this way. The minimization of the effective action reliably determines the energy of the string ground state for a long string and/or for a large number of space-time dimensions. We discuss the possibility of a scaling limit when the cutoff is taken to infinity
Three-boson bound states in finite volume with EFT
The universal properties of a three-boson system with large scattering length are well understood within the framework of Effective Field Theory. They include a geometric spectrum of shallow three-body bound states called Efimov states and log-periodic dependence of scattering observables on the scattering length. We investigate the modification of this spectrum in a finite cubic box using a partial wave expansion. The dependence of the binding energies on the box size is calculated and the renormalization of the Effective Field Theory in finite volume is verified explicitly.
Evidence of Higgs Boson Production through Vector Boson Fusion
AUTHOR|(INSPIRE)INSPIRE-00333580
The discovery of the Higgs boson in 2012 provided confirmation of the proposed mechanism for preserving the electroweak $SU(2) \\times U(1)$ gauge symmetry of the Standard Model of particle physics. It also heralded in a new era of precision Higgs physics. This thesis presents a measurement of the rate at which the Higgs boson is produced by vector boson fusion in the \\wwlnln decay channel. With gauge boson couplings in both the production and decay vertices, a VBF measurement in this channel is a powerful probe of the $VVH$ vertex strength. Using $4.5$~fb$^{-1}$ and $20.3$~fb$^{-1}$ of $pp$ collision data collected at respective center-of-mass energies of 7 and $8 \\tev$ in the ATLAS detector, measurements of the statistical significance and the signal strength are carried out in the Higgs mass range $100 \\leq m_H \\leq 200 \\gev$. These measurements are enhanced with a boosted decision tree that exploits the correlations between eight kinematic inputs in order to separate signal and background processes. At the...
Diffeomorphisms as symplectomorphisms in history phase space: Bosonic string model
The structure of the history phase space G of a covariant field system and its history group (in the sense of Isham and Linden) is analyzed on an example of a bosonic string. The history space G includes the time map T from the spacetime manifold (the two-sheet) Y to a one-dimensional time manifold T as one of its configuration variables. A canonical history action is posited on G such that its restriction to the configuration history space yields the familiar Polyakov action. The standard Dirac-ADM action is shown to be identical with the canonical history action, the only difference being that the underlying action is expressed in two different coordinate charts on G. The canonical history action encompasses all individual Dirac-ADM actions corresponding to different choices T of foliating Y. The history Poisson brackets of spacetime fields on G induce the ordinary Poisson brackets of spatial fields in the instantaneous phase space G0 of the Dirac-ADM formalism. The canonical history action is manifestly invariant both under spacetime diffeomorphisms Diff Y and temporal diffeomorphisms Diff T. Both of these diffeomorphisms are explicitly represented by symplectomorphisms on the history phase space G. The resulting classical history phase space formalism is offered as a starting point for projection operator quantization and consistent histories interpretation of the bosonic string model
Matrix models as CFT: Genus expansion
We show how the formulation of the matrix models as conformal field theories on a Riemann surfaces can be used to compute the genus expansion of the observables. Here we consider the simplest example of the Hermitian matrix model, where the classical solution is described by a hyperelliptic Riemann surface. To each branch point of the Riemann surface we associate an operator which represents a twist field dressed by the modes of the twisted boson. The partition function of the matrix model is computed as a correlation function of such dressed twist fields. The perturbative construction of the dressing operators yields a set of Feynman rules for the genus expansion, which involve vertices, propagators and tadpoles. The vertices are universal, the propagators and the tadpoles depend on the Riemann surface. As a demonstration we evaluate the genus-two free energy using the Feynman rules.
Formal verification - Robust and efficient code: Introduction to Formal Verification
CERN. Geneva
2016-01-01
In general, FV means "proving that certain properties hold for a given system using formal mathematics". This definition can certainly feel daunting, however, as we will learn, we can reap benefits from the paradigm without digging too deep into ...
Composite gauge-bosons made of fermions
Suzuki, Mahiko
2016-01-01
We construct a class of Abelian and non-Abelian local gauge theories that consist only of matter fields of fermions. The Lagrangian is compact and local without containing an auxiliary vector field nor a subsidiary condition on the matter fields. Because of the special structure, this Lagrangian can be extended to non-Abelian gauge symmetry only in the case of SU(2) doublet matter fields. We carry out explicit dynamical computation in the leading 1/N order to show that massless spin-one bound states appear with the correct gauge coupling. Our diagram calculation exposes the dynamical features that cannot be explored in the formal auxiliary vector-field trick. For instance, it shows that the s-wave fermion-antifermion interaction alone cannot form the bound gauge-bosons; the fermion-antifermion pairs must couple to the d-wave state too. Since our models are unrenormalizable in the world of (3+1) dimension, they can be phenomenologically relevant, if at all, only when momentum cutoff is introduced.
Scalable Techniques for Formal Verification
Ray, Sandip
2010-01-01
This book presents state-of-the-art approaches to formal verification techniques to seamlessly integrate different formal verification methods within a single logical foundation. It should benefit researchers and practitioners looking to get a broad overview of the spectrum of formal verification techniques, as well as approaches to combining such techniques within a single framework. Coverage includes a range of case studies showing how such combination is fruitful in developing a scalable verification methodology for industrial designs. This book outlines both theoretical and practical issue
Formal Component-Based Semantics
Madlener, Ken; van Eekelen, Marko; 10.4204/EPTCS.62.2
2011-01-01
One of the proposed solutions for improving the scalability of semantics of programming languages is Component-Based Semantics, introduced by Peter D. Mosses. It is expected that this framework can also be used effectively for modular meta theoretic reasoning. This paper presents a formalization of Component-Based Semantics in the theorem prover Coq. It is based on Modular SOS, a variant of SOS, and makes essential use of dependent types, while profiting from type classes. This formalization constitutes a contribution towards modular meta theoretic formalizations in theorem provers. As a small example, a modular proof of determinism of a mini-language is developed.
Formal Methods: Practice and Experience
Woodcock, Jim; Larsen, Peter Gorm; Bicarregui, Juan;
2009-01-01
Formal methods use mathematical models for analysis and verification at any part of the program life-cycle. We describe the state of the art in the industrial use of formal methods, concentrating on their increasing use at the earlier stages of specification and design. We do this by reporting on a....... Based on this, we discuss the issues surrounding the industrial adoption of formal methods. Finally, we look to the future and describe the development of a Verified Software Repository, part of the worldwide Verified Software Initiative. We introduce the initial projects being used to populate the...
Bosonic interactions with a domain wall
Morris, J R
2016-01-01
We consider here the interaction of scalar bosons with a topological domain wall. Not only is there a continuum of scattering states, but there is also an interesting "quasi-discretuum" of positive energy bosonic bound states, describing bosons entrapped within the wall's core. The full spectrum of the scattering and bound state energies and eigenstates is obtainable from a Schr\\"odinger-type of equation with a P\\"oschl-Teller potential. We also consider the presence of a boson gas within the wall and high energy boson emission.
Excited Weak Bosons and Dark Matter
Fritzsch, Harald
2016-01-01
The weak bosons are bound states of new constituents, the haplons. The p-wave excitations are studied. The state with the lowest mass is identified with the boson, which has been discovered at the LHC. Specific properties of the excited bosons are discussed, in particular their decays into weak bosons and photons. Recently a two photon signal has been observed, which might come from the decay of a neutral heavy boson with a mass of about 0.75 TeV. This particle could be the excited weak tenso...
A geometrical representation of the interacting-boson model of nuclei
The representation of the interacting-boson-model Hamiltonian as a second-order differential operator in geometrical variables is studied in detail. It is shown that, with appropriate boundary conditions and biorthogonal weight functions, it reproduces exactly both the spectrum and matrix elements of operators of the algebraic boson model. It can be written in self-adjoint form and expanded in a symmetrized moment expansion, allowing the identification of collective mass parameters and energy surfaces, but differs in detail from conventional geometrical collective model. (author)
Completeness of spin-3 field in two-boson free-field-realized conformal field theory
We consider the higher- (integer-)spin fields which can be realized with the derivatives of two-boson free fields in two-dimensional conformal quantum field theory. We show that the operator-product expansion (OPE) between higher-spin fields themselves cannot be closed when the spins are larger than 3. Thus, with the requirement of the closure of the OPE, the spin-3 field given by Fateev and Zamolodchikov is uniquely possible---that is, it is ''complete.'' The same analyses on N- (≥3-) boson free-field-realized conformal field theories are discussed
Gravitational Stability of Boson Stars
Kusmartsev, Fjodor V; Schunck, Franz E
1991-01-01
We investigate the stability of general-relativistic boson stars by classifying singularities of differential mappings and compare it with the results of perturbation theory. Depending on the particle number, the star has the following regimes of behavior: stable, metastable, pulsation, and collapse.
How to Detect `Decoupled' Heavy Supersymmetric Higgs Bosons
Bisset, Mike; Li, Jun
2007-01-01
Heretofore neglected decay modes of heavy MSSM Higgs bosons into a variety of neutralino pairs may push the LHC discovery reach for these crucial elements of an extended Higgs sector to nearly the TeV-scale -- if sparticle-sector MSSM input parameters are favorable. This is well into the so-called decoupling region, including moderate to low tan(beta) values, where no known signals exist for said heavy Higgs bosons via decays involving solely SM daughter particles, and the lighter h^0 mimics the lone SM Higgs boson. While the expanse of the Higgs to sparticle discovery region is sensitive to a number of MSSM parameters, including in particular those for the sleptons, its presence is primarily linked to the gaugino inputs -- in fact, to just one parameter, M_2, if gaugino unification is invoked. Thus consideration of high vs. low M_2 realms in the MSSM should be placed on a par with the extensive consideration already given to high vs. low tan(beta) regimes.
Formal and informal contract farming in poultry in Bangladesh
Jabbar, Mohammad A.; Rahman, Md. Habibur; Talukder, R. K.; Raha, S.K.
2008-01-01
Since the early 1990s, contract farming as a market institution in the poultry industry in Bangladesh has evolved along with the expansion of commercial poultry farming. Apart from classical contract farming within vertically integrated enterprises, there are also formal and informal contract arrangements in input marketing and output marketing. In this paper, characteristics of these forms of contract arrangements and their implications for the poultry industry in Bangladesh are discussed. A...
Locally-smeared operator product expansions
Monahan, Christopher
2014-01-01
We propose a "locally-smeared Operator Product Expansion" (sOPE) to decompose non-local operators in terms of a basis of locally-smeared operators. The sOPE formally connects nonperturbative matrix elements of smeared degrees of freedom, determined numerically using the gradient flow, to non-local operators in the continuum. The nonperturbative matrix elements do not suffer from power-divergent mixing on the lattice, provided the smearing scale is kept fixed in the continuum limit. The presence of this smearing scale prevents a simple connection to the standard operator product expansion and therefore requires the construction of a two-scale formalism. We demonstrate the feasibility of our approach using the example of real scalar field theory.
Szczurek, Antoni(Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, PL-31-342, Kraków, Poland); Luszczak, Marta; Maciula, Rafal
2014-01-01
We calculate differential cross sections for Higgs boson and/or two-photon production from intermediate (virtual) Higgs boson within the formalism of $k_t$-factorization. The off-shell $g^* g^* \\to H$ matrix elements are used. We compare results obtained with infinite top fermion (quark) mass and with finite mass taken into account. The latter effect is rather small. We compare results with different unintegrated gluon distributions from the literature. Two methods are used. In the first meth...
El Salvador - Formal Technical Education
Millenium Challenge Corporation — With a budget of nearly $20 million, the Formal Technical Education Sub-Activity was designed to strengthen technical and vocational educational institutions in the...
The sensitivity of the Higgs boson branching ratios to the W boson width
Murray, William
2016-07-01
The Higgs boson branching ratio into vector bosons is sensitive to the decay widths of those vector bosons because they are produced with at least one boson significantly off-shell. Γ (H → VV) is approximately proportional to the product of the Higgs boson coupling and the vector boson width. ΓZ is well measured, but ΓW gives an uncertainty on Γ (H → WW) which is not negligible. The ratio of branching ratios, BR (H → WW) / BR (H → ZZ) measured by a combination of ATLAS and CMS at LHC is used herein to extract a width for the W boson of ΓW =1.8-0.3+0.4 GeV by assuming Standard Model couplings of the Higgs bosons. This dependence of the branching ratio on ΓW is not discussed in most Higgs boson coupling analyses.
The sensitivity of the Higgs boson branching ratios to the W boson width
Murray, William
2016-01-01
The Higgs boson branching ratio into vector bosons is sensitive to the decay widths of those vector bosons because they are produced with at least one boson significantly off-shell. Gamma(H to V V ) is approximately proportional to the product of the Higgs boson coupling and the vector boson width. Gamma Z is well known, but Gamma W gives an uncertainty on Gamma(H to W W ) which is not negligible. The ratio of branching ratios, BR(H to W W )/BR(H to ZZ) measured by a combination of ATLAS and CMS at LHC is used herein to extract a width for the W boson of Gamma W = 1.8+0.4-0.3 GeV by assuming Standard Model couplings of the Higgs bosons. This dependence of the branching ratio on Gamma W is not discussed in most Higgs boson coupling analyses.
Helicity formalism and spin effects
The helicity formalism and the technique to compute amplitudes for interaction processes involving leptons, quarks, photons and gluons are reviewed. Explicit calculations and examples of exploitation of symmetry properties are shown. The formalism is then applied to the discussion of several hadronic processes and spin effects: the experimental data, when related to the properties of the elementary constituent interactions, show many not understood features. Also the nucleon spin problem is briefly reviewed. (author)
Complex cobordism and formal groups
Buchstaber, Viktor M.
2012-10-01
This paper surveys the current state of the theory of cobordism, focusing on geometric and universal properties of complex cobordism, the Landweber-Novikov algebra, and the formal group law of geometric cobordisms. The relationships with K-theory, algebraic cycles, formal group laws, compact Lie group actions on manifolds, toric topology, infinite-dimensional Lie algebras, and nilmanifolds are described. The survey contains key results and open problems. Bibliography: 124 titles.
Beam expansion with specified final distributions
The formation of nearly uniformly distributed beams has been accomplished by the use of multipole magnets. Multipole fields, however, are an inappropriate basis for creating precise distributions, particularly since substantial departures from uniformity are produced with a finite number of multipole elements. A more appropriate formalism that allows precise formation of a desired distribution is presented. Design of nonlinear magnets for uniform-beam production and the optics of an accompanying expansion system are presented
Topological Properties of Rough Soft Formal Context
Li Fu
2014-01-01
In this paper, the topological structure is discussed in the rough soft formal context. The rough soft formal context is defined on the rough formal context with some soft operators, the topology and the topological space are given in the rough soft formal context. And some topological properties are discussed over the rough soft formal context.
In the paper it is noted, that it is necessary to develop dynamical symmetries as U(6) direct X U(4) which take into account a quadrupole nuclear collectivization, a dipole quasi-molecular clusterization as well as an interaction of quadrupole and dipole degrees of freedom. The group chains U(6) direct X U(4) contains SUd(3) direct X Up(3) contains 0(3); U(6) direct X U(4) contains SUd(3) direct X SUp(3) contains 0(3) are investigated. In te both chains the quadrupole collective motion of nucleons generates in an energetic spectrum band of rotational character, classified by representations of (λ, μ), following from the expansion: U(6) contains SU(3). In the lowest order there are (2N, 0), (2N-4.2), k=0+,2+, etc. From group reduction for U(4), taking into account the cluster from of the motion by the model of dipole clusterization of atomic nucleus nucleons, two variant of a theory were developed: a vibration limit of U(4) contains U(3) O(3) and a rotational limit of U(4) contains SU(3) contains O(3). In spite of an apparent identity of groups of U(3) and SU(3) variants of the model generate different spectra of cluster states of atomic nuclei. For the vibration limit the theory predicts an alteration of cluster states of even and odd parities 0+, 1-, 2+, 3-, for the rotational limit there is taken place some electrogenic shift between bands of levels of even and odd parities. The first type of excitations is observed for such nuclei as 28Si, :32S, 36Ar, 44Ti te second type of excitation is observed for light nuclei, such as 16O and 20Ne. An interaction of collective quadrupole and cluster degrees of freedom is taken into account by approximate methods
Prospects for the search for Higgs bosons with vector boson fusion processes at the LHC
Rottlaender, Iris
2007-01-01
The search for the Higgs boson is one of the main physics goals of the Large Hadron Collider (LHC) and its two multi-purpose experiments, ATLAS and CMS. Vector boson fusion is the second largest production process for a standard model Higgs boson at the LHC and offers excellent means for background suppression. This paper gives an overview of the prospects of Higgs boson searches using vector boson fusion at the LHC. For a standard model Higgs boson, the decay channels H->tautau, H->WW and H-...
Supersymmetry and compositeness; dynamical weak gauge bosons
We show at the leading order of 1/N expansion that composite gauge fields in a supersymmetric U(4n + 2)/U(4n) x SU(2) non-linear sigma model become dynamical in some range of parameters. Since the hidden local symmetry in this sigma model is identifiable with a weak SU(2) of the standard electroweak model, we suggest that the observed weak bosons W+- and Z0 are indeed the dynamical gauge fields in the non-linear sigma model. Some phenomenological difficulies in identifing such composite fields with W+- and Z0 are discussed. We also give a brief review on a supersymmetric preon model which generates our non-linear sigma model as a low-energy effective theory. I. Introduction. In spite of the excellent success of the standard electroweak gauge theory [1], it is still unclear to us what the origin of the spontaneous breakdown of the SU(2) x U(1) symmetry is. In the standard scheme, an elementary Higgs scalar phi is assumed to have a vacuum-expectation value not equal 0 which induces the breaking of the electroweak symmetry. The Fermi scale G sub(F)sup(-1/2) is thus related basically to the undetermined, free parameter, . (author)
Bianchini, L; Conway, J; Fowlie, A; Marzola, L; Veelken, C
2016-01-01
We present an algorithm for the reconstruction of the Higgs mass in events with Higgs bosons decaying into a pair of tau leptons. The algorithm is based on matrix element (ME) techniques and achieves a relative resolution on the Higgs boson mass of typically 15-20%. A previous version of the algorithm has been used in analyses of Higgs boson production performed by the CMS collaboration during LHC Run 1. The algorithm is described in detail and its performance on simulated events is assessed. The development of techniques to handle tau decays in the ME formalism represents an important result of this paper.
Unified Equations of Boson and Fermion at High Energy and Some Unifications in Particle Physics
Chang, Yi-Fang
2009-01-01
We suggest some possible approaches of the unified equations of boson and fermion, which correspond to the unified statistics at high energy. A. The spin terms of equations can be neglected. B. The mass terms of equations can be neglected. C. The known equations of formal unification change to the same. They can be combined each other. We derive the chaos solution of the nonlinear equation, in which the chaos point should be a unified scale. Moreover, various unifications in particle physics ...
A short introduction to the quantum formalism[s
David, Francois
2012-01-01
These notes are an elaboration on: (i) a short course that I gave at the IPhT-Saclay in May-June 2012; (ii) a previous letter on reversibility in quantum mechanics. They present an introductory, but hopefully coherent, view of the main formalizations of quantum mechanics, of their interrelations and of their common physical underpinnings: causality, reversibility and locality/separability. The approaches covered are mainly: (ii) the canonical formalism; (ii) the algebraic formalism; (iii) the quantum logic formulation. Other subjects: quantum information approaches, quantum correlations, contextuality and non-locality issues, quantum measurements, interpretations and alternate theories, quantum gravity, are only very briefly and superficially discussed. Most of the material is not new, but is presented in an original, homogeneous and hopefully not technical or abstract way. I try to define simply all the mathematical concepts used and to justify them physically. These notes should be accessible to young physi...
Scattering length of composite bosons in the three-dimensional BCS-BEC crossover
Salasnich, L.; Bighin, G.
2015-03-01
We study the zero-temperature grand potential of a three-dimensional superfluid made of ultracold fermionic alkali-metal atoms in the BCS-BEC crossover. In particular, we analyze the zero-point energy of both fermionic single-particle excitations and bosonic collective excitations. The bosonic elementary excitations, which are crucial to obtain a reliable equation of state in the Bose-Einstein condensate regime, are obtained with a low-momentum expansion up to the forth order of the quadratic (Gaussian) action of the fluctuating pairing field. By performing a cutoff regularization and renormalization of Gaussian fluctuations, we find that the scattering length aB of composite bosons, bound states of fermionic pairs, is given by aB=(2 /3 ) aF , where aF is the scattering length of fermions.
Barbieri, Riccardo; Kannike, Kristjan; Sala, Filippo; Tesi, Andrea
2013-01-01
Now that one has been found, the search for signs of more scalars is a primary task of current and future experiments. In the motivated hypothesis that the extra Higgs bosons of the next-to-minimal supersymmetric Standard Model (NMSSM) be the lightest new particles around, we outline a possible overall strategy to search for signs of the CP-even states. This work complements Ref. arXiv:1304.3670.
The 4 of July 2012, the CERN physicists announced the discovery of the Higgs boson, a particle which existence is essential to the understanding of our world. The paper relates this day which will remain in the history of the physics of particles, and gives some details of the results of the CMS and Atlas experiments on the CERN Large Hadron Collider (LHC). Results from the Fermilab's Tevatron accelerator are also mentioned
Bosonic colored group field theory
Ben Geloun, Joseph [Universite Paris XI, Laboratoire de Physique Theorique, Orsay Cedex (France); University of Abomey-Calavi, Cotonou (BJ). International Chair in Mathematical Physics and Applications (ICMPA-UNESCO Chair); Universite Cheikh Anta Diop, Departement de Mathematiques et Informatique, Faculte des Sciences et Techniques, Dakar (Senegal); Magnen, Jacques [Ecole Polytechnique, Centre de Physique Theorique, Palaiseau Cedex (France); Rivasseau, Vincent [Universite Paris XI, Laboratoire de Physique Theorique, Orsay Cedex (France)
2010-12-15
Bosonic colored group field theory is considered. Focusing first on dimension four, namely the colored Ooguri group field model, the main properties of Feynman graphs are studied. This leads to a theorem on optimal perturbative bounds of Feynman amplitudes in the ''ultraspin'' (large spin) limit. The results are generalized in any dimension. Finally, integrating out two colors we write a new representation, which could be useful for the constructive analysis of this type of models. (orig.)
Electroweak boson production at LHCb
Wallace Ronan
2013-11-01
Full Text Available Measurements of W and Z boson production provide important tests of the Standard Model as well as being inputs for determining the parton density functions of the proton. W and Z production cross-sections, and their ratios, have been measured using the LHCb detector and are reported here. Datasets of up to 1 fb−1 at √s = 7 TeV are used.
Domains of bosonic functional integrals
We propose a mathematical framework for bosonic Euclidean quantum field functional integrals based on the theory of integration on the dual algebraic vector space of classical field sources. We present a generalization of the Minlos-Dao Xing theorem and apply it to determine exactly the domain of integration associated to the functional integral representation of the two-dimensional quantum electrodynamics Schwinger generating functional. (author)
Collider Signatures of Goldstone Bosons
Cheung, Kingman; Yuan, Tzu-Chiang
2014-01-01
Recently Weinberg suggested that Goldstone bosons arising from the spontaneous breakdown of some global hidden symmetries can interact weakly in the early Universe and account for a fraction of the effective number of neutrino species N_{eff}, which has been reported persistently 2\\sigma away from its expected value of three. In this work, we study in some details a number of experimental constraints on this interesting idea based on the simplest possibility of a global U(1), as studied by Weinberg. We work out the decay branching ratios of the associated light scalar field \\sigma and suggest a possible collider signature at the Large Hadron Collider (LHC). In some corners of the parameter space, the scalar field \\sigma can decay into a pair of pions with a branching ratio of order 10% while the rest is mostly a pair of Goldstone bosons. The collider signature would be gluon fusion into the standard model Higgs boson gg -> H followed by H -> \\sigma \\sigma -> (\\pi\\pi) (\\alpha\\alpha) where \\alpha is the Goldsto...
Query Expansion Based on Clustered Results
Liu, Ziyang; Chen, Yi
2011-01-01
Query expansion is a functionality of search engines that suggests a set of related queries for a user-issued keyword query. Typical corpus-driven keyword query expansion approaches return popular words in the results as expanded queries. Using these approaches, the expanded queries may correspond to a subset of possible query semantics, and thus miss relevant results. To handle ambiguous queries and exploratory queries, whose result relevance is difficult to judge, we propose a new framework for keyword query expansion: we start with clustering the results according to user specified granularity, and then generate expanded queries, such that one expanded query is generated for each cluster whose result set should ideally be the corresponding cluster. We formalize this problem and show its APX-hardness. Then we propose two efficient algorithms named iterative single-keyword refinement and partial elimination based convergence, respectively, which effectively generate a set of expanded queries from clustered r...
Distinguishing a SM-like MSSM Higgs boson from SM Higgs boson at muon collider
Jai Kumar Singhal; Sardar Singh; Ashok K Nagawat
2007-06-01
We explore the possibility of distinguishing the SM-like MSSM Higgs boson from the SM Higgs boson via Higgs boson pair production at future muon collider. We study the behavior of the production cross-section in SM and MSSM with Higgs boson mass for various MSSM parameters tan and A. We observe that at fixed CM energy, in the SM, the total cross-section increases with the increase in Higgs boson mass whereas this trend is reversed for the MSSM. The changes that occur for the MSSM in comparison to the SM predictions are quantified in terms of the relative percentage deviation in cross-section. The observed deviations in cross-section for different choices of Higgs boson masses suggest that the measurements of the cross-section could possibly distinguish the SM-like MSSM Higgs boson from the SM Higgs boson.
CMS standard model Higgs boson results
Garcia-Abia Pablo
2013-11-01
Full Text Available In July 2012 CMS announced the discovery of a new boson with properties resembling those of the long-sought Higgs boson. The analysis of the proton-proton collision data recorded by the CMS detector at the LHC, corresponding to integrated luminosities of 5.1 fb−1 at √s = 7 TeV and 19.6 fb−1 at √s = 8 TeV, confirm the Higgs-like nature of the new boson, with a signal strength associated with vector bosons and fermions consistent with the expectations for a standard model (SM Higgs boson, and spin-parity clearly favouring the scalar nature of the new boson. In this note I review the updated results of the CMS experiment.
Bjørner, Dines; George, Chris W.; Haxthausen, Anne Elisabeth;
2004-01-01
This invited paper presents a number of correlated specifications of example railway system problems. They use a variety of partially or fully integrated formal specification. The paper thus represents a mere repository of what we consider interesting case studies. The existence of the Unified...... these different UML views are unified, integrated, correlated or merely co-located is for others to dispute. We also seek to support multiple views, but are also in no doubt that there must be sound, well defined relations between such views. We thus report on ways and means of integrating formal...... techniques such as RAISE (RSL) [58,59], Petri Nets [56,62,37,61,411, Message and Live Sequence Charts [42,43,44,64,13], Statecharts [23,24,26,27], RAISE with Timing (TRSL) [18,45,461, and TRSL with Duration Calculus (79,30]. In this way one achieves a firm foundation for combined uses of these formal...