Inverse-moment chiral sum rules

International Nuclear Information System (INIS)

Golowich, E.; Kambor, J.

1996-01-01

A general class of inverse-moment sum rules was previously derived by the authors in a chiral perturbation theory (ChPT) study at two-loop order of the isospin and hypercharge vector-current propagators. Here, we address the evaluation of the inverse-moment sum rules in terms of existing data and theoretical constraints. Two kinds of sum rules are seen to occur: those which contain as-yet undetermined O(q 6 ) counterterms and those free of such quantities. We use the former to obtain phenomenological evaluations of two O(q 6 ) counterterms. Light is shed on the important but difficult issue regarding contributions of higher orders in the ChPT expansion. copyright 1996 The American Physical Society

QCD sum rules for D mesons. In-medium effects, chiral symmetry aspects and higher orders

Energy Technology Data Exchange (ETDEWEB)

Buchheim, Thomas

2017-04-11

Heavy open flavor mesons can serve as probes of hot and dense, strongly interacting matter in heavy-ion collisions suitable to mimic the extreme conditions shortly after the big-bang or in compact stars. Thus, the thorough theoretical investigation of medium modifications of D mesons is of utmost importance for the interpretation of the experimental data. Even at finite thermodynamic parameters, such as temperature and density, the non-perturbative framework of QCD sum rules allows for the determination of hadronic properties which are not accessible in perturbative quantum chromodynamics (QCD). By virtue of the separation of scales, long-range effects of hadrons are related to quark and gluon degrees of freedom, where features of the hadron spectrum are linked to condensates parameterizing the complex QCD ground state. This thesis furnishes the conception and calculus of QCD sum rules with emphasis on in-medium effects which are inevitable when addressing such effects in higher order contributions. In this regard, the notion and implications of medium-specific condensates are elucidated. Motivated by the significant numerical impact of four-quark condensates to the ρ meson sum rule we evaluate, for the first time, the corresponding in-medium mass-dimension 6 terms for D mesons tentatively employing the factorization hypothesis. Four-quark condensates containing heavy-quark operators may be included into the sum rule analysis utilizing the in-medium heavy-quark expansion made available here. Particular quark condensates are potential order parameters of chiral symmetry breaking, which is the mass generating mechanism of QCD giving the essential mass fraction to light hadrons. The interplay of altered spectral properties with changing in-medium QCD condensates, i. e. the chiral order parameters, can be studied with chiral partner sum rules. Although, introduced for light spin-1 mesons we foster their generalization to spin-0 open charm mesons demonstrating their

QCD sum rules for D mesons. In-medium effects, chiral symmetry aspects and higher orders

International Nuclear Information System (INIS)

Buchheim, Thomas

2017-01-01

Heavy open flavor mesons can serve as probes of hot and dense, strongly interacting matter in heavy-ion collisions suitable to mimic the extreme conditions shortly after the big-bang or in compact stars. Thus, the thorough theoretical investigation of medium modifications of D mesons is of utmost importance for the interpretation of the experimental data. Even at finite thermodynamic parameters, such as temperature and density, the non-perturbative framework of QCD sum rules allows for the determination of hadronic properties which are not accessible in perturbative quantum chromodynamics (QCD). By virtue of the separation of scales, long-range effects of hadrons are related to quark and gluon degrees of freedom, where features of the hadron spectrum are linked to condensates parameterizing the complex QCD ground state. This thesis furnishes the conception and calculus of QCD sum rules with emphasis on in-medium effects which are inevitable when addressing such effects in higher order contributions. In this regard, the notion and implications of medium-specific condensates are elucidated. Motivated by the significant numerical impact of four-quark condensates to the ρ meson sum rule we evaluate, for the first time, the corresponding in-medium mass-dimension 6 terms for D mesons tentatively employing the factorization hypothesis. Four-quark condensates containing heavy-quark operators may be included into the sum rule analysis utilizing the in-medium heavy-quark expansion made available here. Particular quark condensates are potential order parameters of chiral symmetry breaking, which is the mass generating mechanism of QCD giving the essential mass fraction to light hadrons. The interplay of altered spectral properties with changing in-medium QCD condensates, i. e. the chiral order parameters, can be studied with chiral partner sum rules. Although, introduced for light spin-1 mesons we foster their generalization to spin-0 open charm mesons demonstrating their

QCD sum-rules for V-A spectral functions

International Nuclear Information System (INIS)

Chakrabarti, J.; Mathur, V.S.

1980-01-01

The Borel transformation technique of Shifman et al is used to obtain QCD sum-rules for V-A spectral functions. In contrast to the situation in the original Weinberg sum-rules and those of Bernard et al, the problem of saturating the sum-rules by low lying resonances is brought under control. Furthermore, the present sum-rules, on saturation, directly determine useful phenomenological parameters

Neutrino mass sum-rule

Science.gov (United States)

Damanik, Asan

2018-03-01

Neutrino mass sum-rele is a very important research subject from theoretical side because neutrino oscillation experiment only gave us two squared-mass differences and three mixing angles. We review neutrino mass sum-rule in literature that have been reported by many authors and discuss its phenomenological implications.

Sum rules in the response function method

International Nuclear Information System (INIS)

Takayanagi, Kazuo

1990-01-01

Sum rules in the response function method are studied in detail. A sum rule can be obtained theoretically by integrating the imaginary part of the response function over the excitation energy with a corresponding energy weight. Generally, the response function is calculated perturbatively in terms of the residual interaction, and the expansion can be described by diagrammatic methods. In this paper, we present a classification of the diagrams so as to clarify which diagram has what contribution to which sum rule. This will allow us to get insight into the contributions to the sum rules of all the processes expressed by Goldstone diagrams. (orig.)

Sum rules for nuclear collective excitations

International Nuclear Information System (INIS)

Bohigas, O.

1978-07-01

Characterizations of the response function and of integral properties of the strength function via a moment expansion are discussed. Sum rule expressions for the moments in the RPA are derived. The validity of these sum rules for both density independent and density dependent interactions is proved. For forces of the Skyrme type, analytic expressions for the plus one and plus three energy weighted sum rules are given for isoscalar monopole and quadrupole operators. From these, a close relationship between the monopole and quadrupole energies is shown and their dependence on incompressibility and effective mass is studied. The inverse energy weighted sum rule is computed numerically for the monopole operator, and an upper bound for the width of the monopole resonance is given. Finally the reliability of moments given by the RPA with effective interactions is discussed using simple soluble models for the hamiltonian, and also by comparison with experimental data

QCD sum rules in a Bayesian approach

International Nuclear Information System (INIS)

Gubler, Philipp; Oka, Makoto

2011-01-01

A novel technique is developed, in which the Maximum Entropy Method is used to analyze QCD sum rules. The main advantage of this approach lies in its ability of directly generating the spectral function of a given operator. This is done without the need of making an assumption about the specific functional form of the spectral function, such as in the 'pole + continuum' ansatz that is frequently used in QCD sum rule studies. Therefore, with this method it should in principle be possible to distinguish narrow pole structures form continuum states. To check whether meaningful results can be extracted within this approach, we have first investigated the vector meson channel, where QCD sum rules are traditionally known to provide a valid description of the spectral function. Our results exhibit a significant peak in the region of the experimentally observed ρ-meson mass, which agrees with earlier QCD sum rules studies and shows that the Maximum Entropy Method is a useful tool for analyzing QCD sum rules.

'Sum rules' for preequilibrium reactions

International Nuclear Information System (INIS)

Hussein, M.S.

1981-03-01

Evidence that suggests a correct relationship between the optical transmission matrix, P, and the several correlation widths, gamma sub(n), found in nsmission matrix, P, and the several correlation widths, n, found in multistep compound (preequilibrium) nuclear reactions, is presented. A second sum rule is also derived within the shell model approach to nuclear reactions. Indications of the potential usefulness of the sum rules in preequilibrium studies are given. (Author) [pt

Transition sum rules in the shell model

Science.gov (United States)

Lu, Yi; Johnson, Calvin W.

2018-03-01

An important characterization of electromagnetic and weak transitions in atomic nuclei are sum rules. We focus on the non-energy-weighted sum rule (NEWSR), or total strength, and the energy-weighted sum rule (EWSR); the ratio of the EWSR to the NEWSR is the centroid or average energy of transition strengths from an nuclear initial state to all allowed final states. These sum rules can be expressed as expectation values of operators, which in the case of the EWSR is a double commutator. While most prior applications of the double commutator have been to special cases, we derive general formulas for matrix elements of both operators in a shell model framework (occupation space), given the input matrix elements for the nuclear Hamiltonian and for the transition operator. With these new formulas, we easily evaluate centroids of transition strength functions, with no need to calculate daughter states. We apply this simple tool to a number of nuclides and demonstrate the sum rules follow smooth secular behavior as a function of initial energy, as well as compare the electric dipole (E 1 ) sum rule against the famous Thomas-Reiche-Kuhn version. We also find surprising systematic behaviors for ground-state electric quadrupole (E 2 ) centroids in the s d shell.

Fixed mass and scaling sum rules

International Nuclear Information System (INIS)

Ward, B.F.L.

1975-01-01

Using the correspondence principle (continuity in dynamics), the approach of Keppell-Jones-Ward-Taha to fixed mass and scaling current algebraic sum rules is extended so as to consider explicitly the contributions of all classes of intermediate states. A natural, generalized formulation of the truncation ideas of Cornwall, Corrigan, and Norton is introduced as a by-product of this extension. The formalism is illustrated in the familiar case of the spin independent Schwinger term sum rule. New sum rules are derived which relate the Regge residue functions of the respective structure functions to their fixed hadronic mass limits for q 2 → infinity. (Auth.)

A Bayesian analysis of QCD sum rules

International Nuclear Information System (INIS)

Gubler, Philipp; Oka, Makoto

2011-01-01

A new technique has recently been developed, in which the Maximum Entropy Method is used to analyze QCD sum rules. This approach has the virtue of being able to directly generate the spectral function of a given operator, without the need of making an assumption about its specific functional form. To investigate whether useful results can be extracted within this method, we have first studied the vector meson channel, where QCD sum rules are traditionally known to provide a valid description of the spectral function. Our results show a significant peak in the region of the experimentally observed ρ-meson mass, which is in agreement with earlier QCD sum rules studies and suggests that the Maximum Entropy Method is a strong tool for analyzing QCD sum rules.

Adler Function, DIS sum rules and Crewther Relations

International Nuclear Information System (INIS)

Baikov, P.A.; Chetyrkin, K.G.; Kuehn, J.H.

2010-01-01

The current status of the Adler function and two closely related Deep Inelastic Scattering (DIS) sum rules, namely, the Bjorken sum rule for polarized DIS and the Gross-Llewellyn Smith sum rule are briefly reviewed. A new result is presented: an analytical calculation of the coefficient function of the latter sum rule in a generic gauge theory in order O(α s 4 ). It is demonstrated that the corresponding Crewther relation allows to fix two of three colour structures in the O(α s 4 ) contribution to the singlet part of the Adler function.

Isospin sum rules for inclusive cross-sections

NARCIS (Netherlands)

Rotelli, P.; Suttorp, L.G.

1972-01-01

A systematic analysis of isospin sum rules is presented for the distribution functions of strong, electromagnetic weak inclusive processes. The general expression for these sum rules is given and some new examples are presented.

A bayesian approach to QCD sum rules

International Nuclear Information System (INIS)

Gubler, Philipp; Oka, Makoto

2010-01-01

QCD sum rules are analyzed with the help of the Maximum Entropy Method. We develop a new technique based on the Bayesion inference theory, which allows us to directly obtain the spectral function of a given correlator from the results of the operator product expansion given in the deep euclidean 4-momentum region. The most important advantage of this approach is that one does not have to make any a priori assumptions about the functional form of the spectral function, such as the 'pole + continuum' ansatz that has been widely used in QCD sum rule studies, but only needs to specify the asymptotic values of the spectral function at high and low energies as an input. As a first test of the applicability of this method, we have analyzed the sum rules of the ρ-meson, a case where the sum rules are known to work well. Our results show a clear peak structure in the region of the experimental mass of the ρ-meson. We thus demonstrate that the Maximum Entropy Method is successfully applied and that it is an efficient tool in the analysis of QCD sum rules. (author)

QCD sum rules and applications to nuclear physics

Energy Technology Data Exchange (ETDEWEB)

Cohen, T D [Maryland Univ., College Park, MD (United States). Dept. of Physics; [Washington Univ., Seattle, WA (United States). Dept. of Physics and Inst. for Nuclear Theory; Furnstahl, R J [Ohio State Univ., Columbus, OH (United States). Dept. of Physics; Griegel, D K [Maryland Univ., College Park, MD (United States). Dept. of Physics; [TRIUMF, Vancouver, BC (Canada); Xuemin, J

1994-12-01

Applications of QCD sum-rule methods to the physics of nuclei are reviewed, with an emphasis on calculations of baryon self-energies in infinite nuclear matter. The sum-rule approach relates spectral properties of hadrons propagating in the finite-density medium, such as optical potentials for quasinucleons, to matrix elements of QCD composite operators (condensates). The vacuum formalism for QCD sum rules is generalized to finite density, and the strategy and implementation of the approach is discussed. Predictions for baryon self-energies are compared to those suggested by relativistic nuclear physics phenomenology. Sum rules for vector mesons in dense nuclear matter are also considered. (author). 153 refs., 8 figs.

QCD sum rules and applications to nuclear physics

International Nuclear Information System (INIS)

Cohen, T.D.; Xuemin, J.

1994-12-01

Applications of QCD sum-rule methods to the physics of nuclei are reviewed, with an emphasis on calculations of baryon self-energies in infinite nuclear matter. The sum-rule approach relates spectral properties of hadrons propagating in the finite-density medium, such as optical potentials for quasinucleons, to matrix elements of QCD composite operators (condensates). The vacuum formalism for QCD sum rules is generalized to finite density, and the strategy and implementation of the approach is discussed. Predictions for baryon self-energies are compared to those suggested by relativistic nuclear physics phenomenology. Sum rules for vector mesons in dense nuclear matter are also considered. (author)

Proof of Kochen–Specker Theorem: Conversion of Product Rule to Sum Rule

International Nuclear Information System (INIS)

Toh, S.P.; Zainuddin, Hishamuddin

2009-01-01

Valuation functions of observables in quantum mechanics are often expected to obey two constraints called the sum rule and product rule. However, the Kochen–Specker (KS) theorem shows that for a Hilbert space of quantum mechanics of dimension d ≤ 3, these constraints contradict individually with the assumption of value definiteness. The two rules are not irrelated and Peres [Found. Phys. 26 (1996) 807] has conceived a method of converting the product rule into a sum rule for the case of two qubits. Here we apply this method to a proof provided by Mermin based on the product rule for a three-qubit system involving nine operators. We provide the conversion of this proof to one based on sum rule involving ten operators. (general)

Gaussian sum rules for optical functions

International Nuclear Information System (INIS)

Kimel, I.

1981-12-01

A new (Gaussian) type of sum rules (GSR) for several optical functions, is presented. The functions considered are: dielectric permeability, refractive index, energy loss function, rotatory power and ellipticity (circular dichroism). While reducing to the usual type of sum rules in a certain limit, the GSR contain in general, a Gaussian factor that serves to improve convergence. GSR might be useful in analysing experimental data. (Author) [pt

The Gross-Llewellyn Smith sum rule

International Nuclear Information System (INIS)

Scott, W.G.

1981-01-01

We present the most recent data on the Gross-Llewellyn Smith sum rule obtained from the combined BEBC Narrow Band Neon and GGM-PS Freon neutrino/antineutrino experiments. The data for the Gross-Llewellyn Smith sum rule as a function of q 2 suggest a smaller value for the QCD coupling constant parameter Λ than is obtained from the analysis of the higher moments. (author)

Lattice QCD evaluation of baryon magnetic moment sum rules

International Nuclear Information System (INIS)

Leinweber, D.B.

1991-05-01

Magnetic moment combinations and sum rules are evaluated using recent results for the magnetic moments of octet baryons determined in a numerical simulation of quenched QCD. The model-independent and parameter-free results of the lattice calculations remove some of the confusion and contradiction surrounding past magnetic moment sum rule analyses. The lattice results reveal the underlying quark dynamics investigated by magnetic moment sum rules and indicate the origin of magnetic moment quenching for the non-strange quarks in Σ. In contrast to previous sum rule analyses, the magnetic moments of nonstrange quarks in Ξ are seen to be enhanced in the lattice results. In most cases, the spin-dependent dynamics and center-of-mass effects giving rise to baryon dependence of the quark moments are seen to be sufficient to violate the sum rules in agreement with experimental measurements. In turn, the sum rules are used to further examine the results of the lattice simulation. The Sachs sum rule suggests that quark loop contributions not included in present lattice calculations may play a key role in removing the discrepancies between lattice and experimental ratios of magnetic moments. This is supported by other sum rules sensitive to quark loop contributions. A measure of the isospin symmetry breaking in the effective quark moments due to quark loop contributions is in agreement with model expectations. (Author) 16 refs., 2 figs., 2 tabs

Singular f-sum rule for superfluid 4He

International Nuclear Information System (INIS)

Wong, V.K.

1979-01-01

The validity and applicability to inelastic neutron scattering of a singular f-sum rule for superfluid helium, proposed by Griffin to explain the rhosub(s) dependence in S(k, ω) as observed by Woods and Svensson, are examined in the light of similar sum rules rigorously derived for anharmonic crystals and Bose liquids. It is concluded that the singular f-sum rules are only of microscopic interest. (Auth,)

Superconvergent sum rules for the normal reflectivity

International Nuclear Information System (INIS)

Furuya, K.; Zimerman, A.H.; Villani, A.

1976-05-01

Families of superconvergent relations for the normal reflectivity function are written. Sum rules connecting the difference of phases of the reflectivities of two materials are also considered. Finally superconvergence relations and sum rules for magneto-reflectivity in the Faraday and Voigt regimes are also studied

Chiral corrections to the Adler-Weisberger sum rule

Science.gov (United States)

Beane, Silas R.; Klco, Natalie

2016-12-01

The Adler-Weisberger sum rule for the nucleon axial-vector charge, gA , offers a unique signature of chiral symmetry and its breaking in QCD. Its derivation relies on both algebraic aspects of chiral symmetry, which guarantee the convergence of the sum rule, and dynamical aspects of chiral symmetry breaking—as exploited using chiral perturbation theory—which allow the rigorous inclusion of explicit chiral symmetry breaking effects due to light-quark masses. The original derivations obtained the sum rule in the chiral limit and, without the benefit of chiral perturbation theory, made various attempts at extrapolating to nonvanishing pion masses. In this paper, the leading, universal, chiral corrections to the chiral-limit sum rule are obtained. Using PDG data, a recent parametrization of the pion-nucleon total cross sections in the resonance region given by the SAID group, as well as recent Roy-Steiner equation determinations of subthreshold amplitudes, threshold parameters, and correlated low-energy constants, the Adler-Weisberger sum rule is confronted with experimental data. With uncertainty estimates associated with the cross-section parametrization, the Goldberger-Treimann discrepancy, and the truncation of the sum rule at O (Mπ4) in the chiral expansion, this work finds gA=1.248 ±0.010 ±0.007 ±0.013 .

Spectral sum rules for the three-body problem

International Nuclear Information System (INIS)

Bolle, D.; Osborn, T.A.

1982-01-01

This paper derives a number of sum rules for nonrelativistic three-body scattering. These rules are valid for any finite region μ in the six-dimensional coordinate space. They relate energy moments of the trace of the onshell time-delay operator to the energy-weighted probability for finding the three-body bound-state wave functions in the region μ. If μ is all of the six-dimensional space, the global form of the sum rules is obtained. In this form the rules constitute higher-order Levinson's theorems for the three-body problem. Finally, the sum rules are extended to allow the energy momtns have complex powers

Sum rules for neutrino oscillations

International Nuclear Information System (INIS)

Kobzarev, I.Yu.; Martemyanov, B.V.; Okun, L.B.; Schepkin, M.G.

1981-01-01

Sum rules for neutrino oscillations are obtained. The derivation of the general form of the s matrix for two stage process lsub(i)sup(-)→ν→lsub(k)sup(+-) (where lsub(i)sup(-)e, μ, tau, ... are initial leptons with flavor i and lsub(k)sup(+-) is final lepton) is presented. The consideration of two stage process lsub(i)sup(-)→ν→lsub(k)sup(+-) gives the possibility to take into account neutrino masses and to obtain the expressions for the oscillating cross sections. In the case of Dirac and left-handed Majorana neutrino is obtained the sum rule for the quantities 1/Vsub(K)σ(lsub(i)sup(-)→lsub(K)sup(+-)), (where Vsub(K) is a velocity of lsub(K)). In the left-handed Majorana neutrino case there is an additional antineutrino admixture leading to lsub(i)sup(-)→lsub(K)sup(+) process. Both components (neutrino and antineutrino) oscillate independently. The sums Σsub(K)1/Vsub(k)σ(lsub(i)sup(-) - lsub(K)sup(+-) then oscillate due to the presence of left-handed antineutrinos and right-handed neutrinos which do not take part in weak interactions. If right-handed currents are added sum rules analogous to considered above may be obtained. All conclusions are valid in the general case when CP is not conserved [ru

Systematics of strength function sum rules

Directory of Open Access Journals (Sweden)

Calvin W. Johnson

2015-11-01

Full Text Available Sum rules provide useful insights into transition strength functions and are often expressed as expectation values of an operator. In this letter I demonstrate that non-energy-weighted transition sum rules have strong secular dependences on the energy of the initial state. Such non-trivial systematics have consequences: the simplification suggested by the generalized Brink–Axel hypothesis, for example, does not hold for most cases, though it weakly holds in at least some cases for electric dipole transitions. Furthermore, I show the systematics can be understood through spectral distribution theory, calculated via traces of operators and of products of operators. Seen through this lens, violation of the generalized Brink–Axel hypothesis is unsurprising: one expects sum rules to evolve with excitation energy. Furthermore, to lowest order the slope of the secular evolution can be traced to a component of the Hamiltonian being positive (repulsive or negative (attractive.

Vacuum structure and QCD sum rules

International Nuclear Information System (INIS)

Shifman, M.A.

1992-01-01

The method of the QCD sum rules was and still is one of the most productive tools in a wide range of problems associated with the hadronic phenomenology. Many heuristic ideas, computational devices, specific formulae which are useful to theorists working not only in hadronic physics, have been accumulated in this method. Some of the results and approaches which have originally been developed in connection with the QCD sum rules can be and are successfully applied in related fields, as supersymmetric gauge theories, nontraditional schemes of quarks and leptons, etc. The amount of literature on these and other more basic problems in hadronic physics has grown enormously in recent years. This volume presents a collection of papers which provide an overview of all basic elements of the sum rule approach and priority has been given to the works which seemed most useful from a pedagogical point of view

Vacuum structure and QCD sum rules

International Nuclear Information System (INIS)

Shifman, M.A.

1992-01-01

The method of the QCD sum rules was and still is one of the most productive tools in a wide range of problems associated with the hadronic phenomenology. Many heuristic ideas, computational devices, specific formulae which are useful to theorists working not only in hadronic physics, have been accumulated in this method. Some of the results and approaches which have been originally developed in connection with the QCD sum rules can be and are successfully applied in related fields, such as supersymmetric gauge theories, nontraditional schemes of quarks and leptons, etc. The amount of literature on these and other more basic problems in hadronic physics has grown enormously in recent years. This collection of papers provides an overview of all basic elements of the sum rule approach. Priority has been given to those works which seemed most useful from a pedagogical point of view

The α3S corrections to the Bjorken sum rule for polarized electro-production and to the Gross-Llewellyn Smith sum rule

International Nuclear Information System (INIS)

Larin, S.A.; Nationaal Inst. voor Kernfysica en Hoge-Energiefysica; Vermaseren, J.A.M.

1990-01-01

The next-next-to-leading order QCD corrections to the Gross-Llewellyn Smith sum rule for deep inelastic neutrino-nucleon scattering and to the Bjorken sum rule for polarized electron-nucleon scattering have been computed. This involved the proper treatment of γ 5 inside the loop integrals with dimensional regularization. It is found that the difference between the two sum rules are entirely due to a class of 6 three loop graphs and is of the order of 1% of the leading QCD term. Hence the Q 2 behavior of both sum rules should be the same if the physics is described adequately by the lower order terms of perturbative QCD. (author). 12 refs.; 2 figs.; 4 tabs

Feynman rules of quantum chromodynamics inside a hadron

International Nuclear Information System (INIS)

Lee, T.D.

1979-01-01

We start from quantum chromodynamics in a finite volume of linear size L and examine its color-dielectric constant kappa/sub L/, especially the limit kappa/sub infinity/ as L → infinity. By choosing as our standard kappa/sub L/ = 1 when L = some hadron size R, we conclude that kappa/sub infinity/ must be -2 α where α is the fine-structure constant of QCD inside the hadron. A permanent quark confinement corresponds to the limit kappa/sub infinity/ = 0. The hadrons are viewed as small domain structures (with color-dielectric constant = 1) immersed in a perfect, or nearly perfect, color-dia-electric medium, which is the vacuum. The Feynman rules of QCD inside the hadron are derived; they are found to depend on the color-dielectric constant kappa/sub infinity/ of the vacuum that lies outside. We show that, when kappa/sub infinity/ → 0, the mass of any color-nonsinglet state becomes infinity, but for color-singlet states their masses and scattering amplitudes remain finite. These new Feynman rules also depend on the hadron size R. Only at high energy and large four-momentum transfer can such R dependence be neglected and, for color-singlet states, these new rules be reduced to the usual ones

Novel nuclear phenomena in quantum chromodynamics

International Nuclear Information System (INIS)

Brodsky, S.J.

1987-08-01

Many of the key issues in understanding quantum chromodynamics involve processes in nuclear targets at intermediate energies. A range of hadronic and nuclear phenomena-exclusive processes, color transparency, hidden color degrees of freedom in nuclei, reduced nuclear amplitudes, jet coalescence, formation zone effects, hadron helicity selection rules, spin correlations, higher twist effects, and nuclear diffraction were discussed as tools for probing hadron structure and the propagation of quark and gluon jets in nuclei. Several areas were also reviewed where there has been significant theoretical progress determining the form of hadron and nuclear wave functions, including QCD sum rules, lattice gauge theory, and discretized light-cone quantization. A possible interpretation was also discussed of the large spin correlation A/sub NN/ in proton-proton scattering, and how relate this effect to an energy and angular dependence of color transparency in nuclei. 76 refs., 24 figs

Cosmic-ray sum rules

International Nuclear Information System (INIS)

Frandsen, Mads T.; Masina, Isabella; Sannino, Francesco

2011-01-01

We introduce new sum rules allowing to determine universal properties of the unknown component of the cosmic rays; we show how they can be used to predict the positron fraction at energies not yet explored by current experiments, and to constrain specific models.

Compton scattering from nuclei and photo-absorption sum rules

International Nuclear Information System (INIS)

Gorchtein, Mikhail; Hobbs, Timothy; Londergan, J. Timothy; Szczepaniak, Adam P.

2011-01-01

We revisit the photo-absorption sum rule for real Compton scattering from the proton and from nuclear targets. In analogy with the Thomas-Reiche-Kuhn sum rule appropriate at low energies, we propose a new 'constituent quark model' sum rule that relates the integrated strength of hadronic resonances to the scattering amplitude on constituent quarks. We study the constituent quark model sum rule for several nuclear targets. In addition, we extract the α=0 pole contribution for both proton and nuclei. Using the modern high-energy proton data, we find that the α=0 pole contribution differs significantly from the Thomson term, in contrast with the original findings by Damashek and Gilman.

On contribution of instantons to nucleon sum rules

International Nuclear Information System (INIS)

Dorokhov, A.E.; Kochelev, N.I.

1989-01-01

The contribution of instantons to nucleon QCD sum rules is obtained. It is shown that this contribution does provide stabilization of the sum rules and leads to formation of a nucleon as a bound state of quarks in the instanton field. 17 refs.; 3 figs

Adler-Weisberger sum rule for WLWL→WLWL scattering

International Nuclear Information System (INIS)

Pham, T.N.

1991-01-01

We analyse the Adler-Weisberger sum rule for W L W L →W L W L scattering. We find that at some energy, the W L W L total cross section must be large to saturate the sum rule. Measurements at future colliders would be needed to check the sum rule and to obtain the decay rates Γ(H→W L W L , Z L Z L ) which would be modified by the existence of a P-wave vector meson resonance in the standard model with strongly interacting Higgs sector or in technicolour models. (orig.)

Parity of Θ+(1540) from QCD sum rules

International Nuclear Information System (INIS)

Lee, Su Houng; Kim, Hungchong; Kwon, Youngshin

2005-01-01

The QCD sum rule for the pentaquark Θ + , first analyzed by Sugiyama, Doi and Oka, is reanalyzed with a phenomenological side that explicitly includes the contribution from the two-particle reducible kaon-nucleon intermediate state. The magnitude for the overlap of the Θ + interpolating current with the kaon-nucleon state is obtained by using soft-kaon theorem and a separate sum rule for the ground state nucleon with the pentaquark nucleon interpolating current. It is found that the K-N intermediate state constitutes only 10% of the sum rule so that the original claim that the parity of Θ + is negative remains valid

Sum rules for the quarkonium systems

International Nuclear Information System (INIS)

Burnel, A.; Caprasse, H.

1980-01-01

In the framework of the radial Schroedinger equation we derive in a very simple way sum rules relating the potential to physical quantities such as the energy eigenvalues and the square of the lth derivative of the eigenfunctions at the origin. These sum rules contain as particular cases well-known results such as the quantum version of the Clausius theorem in classical mechanics as well as Kramers's relations for the Coulomb potential. Several illustrations are given and the possibilities of applying them to the quarkonium systems are considered

Coulomb sum rules in the relativistic Fermi gas model

International Nuclear Information System (INIS)

Do Dang, G.; L'Huillier, M.; Nguyen Giai, Van.

1986-11-01

Coulomb sum rules are studied in the framework of the Fermi gas model. A distinction is made between mathematical and observable sum rules. Differences between non-relativistic and relativistic Fermi gas predictions are stressed. A method to deduce a Coulomb response function from the longitudinal response is proposed and tested numerically. This method is applied to the 40 Ca data to obtain the experimental Coulomb sum rule as a function of momentum transfer

Sum rules for nuclear excitations with the Skyrme-Landau interaction

International Nuclear Information System (INIS)

Liu Kehfei; Luo Hongde; Ma Zhongyu; Feng Man; Shen Qingbiao

1991-01-01

The energy-weighted sum rules for electric, magnetic, Fermi and Gamow-Teller transitions with the Skyrme-Landau interaction are derived from the double commutators and numerically calculated in a HF + RPA formalism. As a numerical check of the Thouless theorem, our self-consistent calculations show that the calculated RPA strengths exhaust more than 85% of the sum rules in most cases. The well known non-energy-weighted sum rules for Fermi and Gamow-Teller transitions are also checked numerically. The sum rules are exhausted by more than 94% in these cases. (orig.)

Light cone sum rules in nonabelian gauge field theory

Energy Technology Data Exchange (ETDEWEB)

Mallik, S [Bern Univ. (Switzerland). Inst. fuer Theoretische Physik

1981-03-24

The author examines, in the context of nonabelian gauge field theory, the derivation of the light cone sum rules which were obtained earlier on the assumption of dominance of canonical singularity in the current commutator on the light cone. The retarded scaling functions appearing in the sum rules are numbers known in terms of the charges of the quarks and the number of quarks and gluons in the theory. Possible applications of the sum rules are suggested.

Light cone sum rules for single-pion electroproduction

International Nuclear Information System (INIS)

Mallik, S.

1978-01-01

Light cone dispersion sum rules (of low energy and superconvergence types) are derived for nucleon matrix elements of the commutator involving electromagnetic and divergence of axial vector currents. The superconvergence type sum rules in the fixed mass limit are rewritten without requiring the knowledge of Regge subtractions. The retarded scaling functions occurring in these sum rules are evaluated within the framework of quark light cone algebra of currents. Besides a general consistency check of the framework underlying the derivation, the author infers, on the basis of crude evaluation of scaling functions, an upper limit of 100 MeV for the bare mass of nonstrange quarks. (Auth.)

Moessbauer sum rules for use with synchrotron sources

International Nuclear Information System (INIS)

Lipkin, Harry J.

1999-01-01

The availability of tunable synchrotron radiation sources with millivolt resolution has opened new prospects for exploring dynamics of complex systems with Moessbauer spectroscopy. Early Moessbauer treatments and moment sum rules are extended to treat inelastic excitations measured in synchrotron experiments, with emphasis on the unique new conditions absent in neutron scattering and arising in resonance scattering: prompt absorption, delayed emission, recoil-free transitions and coherent forward scattering. The first moment sum rule normalizes the inelastic spectrum. New sum rules obtained for higher moments include the third moment proportional to the second derivative of the potential acting on the Moessbauer nucleus and independent of temperature in the the harmonic approximation

Sum Rules, Classical and Quantum - A Pedagogical Approach

Science.gov (United States)

Karstens, William; Smith, David Y.

2014-03-01

Sum rules in the form of integrals over the response of a system to an external probe provide general analytical tools for both experiment and theory. For example, the celebrated f-sum rule gives a system's plasma frequency as an integral over the optical-dipole absorption spectrum regardless of the specific spectral distribution. Moreover, this rule underlies Smakula's equation for the number density of absorbers in a sample in terms of the area under their absorption bands. Commonly such rules are derived from quantum-mechanical commutation relations, but many are fundamentally classical (independent of ℏ) and so can be derived from more transparent mechanical models. We have exploited this to illustrate the fundamental role of inertia in the case of optical sum rules. Similar considerations apply to sum rules in many other branches of physics. Thus, the ``attenuation integral theorems'' of ac circuit theory reflect the ``inertial'' effect of Lenz's Law in inductors or the potential energy ``storage'' in capacitors. These considerations are closely related to the fact that the real and imaginary parts of a response function cannot be specified independently, a result that is encapsulated in the Kramers-Kronig relations. Supported in part by the US Department of Energy, Office of Nuclear Physics under contract DE-AC02-06CH11357.

Introduction to non-perturbative quantum chromodynamics

International Nuclear Information System (INIS)

Pene, O.

1995-01-01

Quantum chromodynamics is considered to be the theory of strong interaction. The main peculiarity of this theory is that its asymptotic states (hadrons) are different from its elementary fields (quarks and gluons). This property plays a great part in any physical process involving small momentum-energy transfers. In such a range perturbative methods are no longer allowed. This work focuses on other tools such as QCD symmetry, the quark model, Green functions and the sum rules. To get hadron characteristics numerically, QCD on lattices is used but only in the case of simple process involving no more than one hadron in the initial and final states because of the complexity of the Green function. Some examples using a Monte-Carlo simulation are given. (A.C.)

QCD sum rules for the gluon component of the U(1)sub(A) pseudoscalar meson

International Nuclear Information System (INIS)

Narison, S.; Centre National de la Recherche Scientifique, 13 - Marseille

1981-01-01

Using sum rules based on the positivity and the analyticity of the U(1)sub(A) spectral functions, and within the framework of QCD (quantum chromodynamics), we derive an upper bound Msub(p) approximately less than (0.6 approximately 0.75) GeV to the gluon component of the U(1)sub(A) meson mass. Such a bound could be identified as the exact value of Msub(p) if one accepts a QCD model for the ''continuum'' contribution to the U(1)sub(A) spectral functions. Comparing our result to the observed mass Msub(eta)' approximately equal to 0.96GeV, one could expect an important gluonic contribution to the eta'-mass. This experimental result could be reproduced, if one adds to our result, the quark contribution known to be Msub(q) approximately equal to root(3)msub(π). (author)

Derivation of sum rules for quark and baryon fields

International Nuclear Information System (INIS)

Bongardt, K.

1978-01-01

In an analogous way to the Weinberg sum rules, two spectral-function sum rules for quark and baryon fields are derived by means of the concept of lightlike charges. The baryon sum rules are valid for the case of SU 3 as well as for SU 4 and the one-particle approximation yields a linear mass relation. This relation is not in disagreement with the normal linear GMO formula for the baryons. The calculated masses of the first resonance states agree very well with the experimental data

New QCD sum rules for nucleon axial-vector coupling constants

International Nuclear Information System (INIS)

Lee, F.X.; Leinweber, D.B.; Jin, X.

1997-01-01

Two new sets of QCD sum rules for the nucleon axial-vector coupling constants are derived using the external-field technique and generalized interpolating fields. An in-depth study of the predicative ability of these sum rules is carried out using a Monte Carlo based uncertainty analysis. The results show that the standard implementation of the QCD sum rule method has only marginal predicative power for the nucleon axial-vector coupling constants, as the relative errors are large. The errors range from approximately 50% to 100% compared to the nucleon mass obtained from the same method, which has only a 10%- 25% error. The origin of the large errors is examined. Previous analyses of these coupling constants are based on sum rules that have poor operator product expansion convergence and large continuum contributions. Preferred sum rules are identified and their predictions are obtained. We also investigate the new sum rules with an alternative treatment of the problematic transitions which are not exponentially suppressed in the standard treatment. The alternative treatment provides exponential suppression of their contributions relative to the ground state. Implications for other nucleon current matrix elements are also discussed. copyright 1997 The American Physical Society

On the Laplace transform of the Weinberg type sum rules

International Nuclear Information System (INIS)

Narison, S.

1981-09-01

We consider the Laplace transform of various sum rules of the Weinberg type including the leading non-perturbative effects. We show from the third type Weinberg sum rules that 7.5 to 8.9 1 coupling to the W boson, while the second sum rule gives an upper bound on the A 1 mass (Msub(A 1 ) < or approx. 1.25 GeV). (author)

Integrals of Lagrange functions and sum rules

Energy Technology Data Exchange (ETDEWEB)

Baye, Daniel, E-mail: dbaye@ulb.ac.be [Physique Quantique, CP 165/82, Universite Libre de Bruxelles, B 1050 Bruxelles (Belgium); Physique Nucleaire Theorique et Physique Mathematique, CP 229, Universite Libre de Bruxelles, B 1050 Bruxelles (Belgium)

2011-09-30

Exact values are derived for some matrix elements of Lagrange functions, i.e. orthonormal cardinal functions, constructed from orthogonal polynomials. They are obtained with exact Gauss quadratures supplemented by corrections. In the particular case of Lagrange-Laguerre and shifted Lagrange-Jacobi functions, sum rules provide exact values for matrix elements of 1/x and 1/x{sup 2} as well as for the kinetic energy. From these expressions, new sum rules involving Laguerre and shifted Jacobi zeros and weights are derived. (paper)

Inclusive sum rules and spectra of neutrons at the ISR

International Nuclear Information System (INIS)

Grigoryan, A.A.

1975-01-01

Neutron spectra in pp collisions at ISR energies are studied in the framework of sum rules for inclusive processes. The contributions of protons, π- and E- mesons to the energy sum rule are calculated at √5 = 53 GeV. It is shown by means of this sum rule that the spectra of neutrons at the ISR are in contradiction with the spectra of other particles also measured at the ISR

Luttinger and Hubbard sum rules: are they compatible?

International Nuclear Information System (INIS)

Matho, K.

1992-01-01

A so-called Hubbard sum rule determines the weight of a satellite in fermionic single-particle excitations with strong local repulsion (U→∞). Together with the Luttinger sum rule, this imposes two different energy scales on the remaining finite excitations. In the Hubbard chain, this has been identified microscopically as being due to a separation of spin and charge. (orig.)

Energy-weighted sum rules for mesons in hot and dense matter

NARCIS (Netherlands)

Cabrera, D.; Polls, A.; Ramos, A.; Tolos Rigueiro, Laura

2009-01-01

We study energy-weighted sum rules of the pion and kaon propagator in nuclear matter at finite temperature. The sum rules are obtained from matching the Dyson form of the meson propagator with its spectral Lehmann representation at low and high energies. We calculate the sum rules for specific

Complex-energy approach to sum rules within nuclear density functional theory

Science.gov (United States)

Hinohara, Nobuo; Kortelainen, Markus; Nazarewicz, Witold; Olsen, Erik

2015-04-01

Background: The linear response of the nucleus to an external field contains unique information about the effective interaction, the correlations governing the behavior of the many-body system, and the properties of its excited states. To characterize the response, it is useful to use its energy-weighted moments, or sum rules. By comparing computed sum rules with experimental values, the information content of the response can be utilized in the optimization process of the nuclear Hamiltonian or the nuclear energy density functional (EDF). But the additional information comes at a price: compared to the ground state, computation of excited states is more demanding. Purpose: To establish an efficient framework to compute energy-weighted sum rules of the response that is adaptable to the optimization of the nuclear EDF and large-scale surveys of collective strength, we have developed a new technique within the complex-energy finite-amplitude method (FAM) based on the quasiparticle random-phase approximation (QRPA). Methods: To compute sum rules, we carry out contour integration of the response function in the complex-energy plane. We benchmark our results against the conventional matrix formulation of the QRPA theory, the Thouless theorem for the energy-weighted sum rule, and the dielectric theorem for the inverse-energy-weighted sum rule. Results: We derive the sum-rule expressions from the contour integration of the complex-energy FAM. We demonstrate that calculated sum-rule values agree with those obtained from the matrix formulation of the QRPA. We also discuss the applicability of both the Thouless theorem about the energy-weighted sum rule and the dielectric theorem for the inverse-energy-weighted sum rule to nuclear density functional theory in cases when the EDF is not based on a Hamiltonian. Conclusions: The proposed sum-rule technique based on the complex-energy FAM is a tool of choice when optimizing effective interactions or energy functionals. The method

Light-cone sum rules: A SCET-based formulation

CERN Document Server

De Fazio, F; Hurth, Tobias; Feldmann, Th.

2007-01-01

We describe the construction of light-cone sum rules (LCSRs) for exclusive $B$-meson decays into light energetic hadrons from correlation functions within soft-collinear effective theory (SCET). As an example, we consider the SCET sum rule for the $B \\to \\pi$ transition form factor at large recoil, including radiative corrections from hard-collinear loop diagrams at first order in the strong coupling constant.

3He electron scattering sum rules

International Nuclear Information System (INIS)

Kim, Y.E.; Tornow, V.

1982-01-01

Electron scattering sum rules for 3 He are derived with a realistic ground-state wave function. The theoretical results are compared with the experimentally measured integrated cross sections. (author)

Counter-ions at single charged wall: Sum rules.

Science.gov (United States)

Samaj, Ladislav

2013-09-01

For inhomogeneous classical Coulomb fluids in thermal equilibrium, like the jellium or the two-component Coulomb gas, there exists a variety of exact sum rules which relate the particle one-body and two-body densities. The necessary condition for these sum rules is that the Coulomb fluid possesses good screening properties, i.e. the particle correlation functions or the averaged charge inhomogeneity, say close to a wall, exhibit a short-range (usually exponential) decay. In this work, we study equilibrium statistical mechanics of an electric double layer with counter-ions only, i.e. a globally neutral system of equally charged point-like particles in the vicinity of a plain hard wall carrying a fixed uniform surface charge density of opposite sign. At large distances from the wall, the one-body and two-body counter-ion densities go to zero slowly according to the inverse-power law. In spite of the absence of screening, all known sum rules are shown to hold for two exactly solvable cases of the present system: in the weak-coupling Poisson-Boltzmann limit (in any spatial dimension larger than one) and at a special free-fermion coupling constant in two dimensions. This fact indicates an extended validity of the sum rules and provides a consistency check for reasonable theoretical approaches.

Moessbauer sum rules for use with synchrotron sources

International Nuclear Information System (INIS)

Lipkin, H.J.

1995-01-01

The availability of tunable synchrotron radiation sources with millivolt resolution has opened prospects for exploring dynamics of complex systems with Moessbauer spectroscopy. Early Moessbauer treatments and moment sum rules are extended to treat inelastic excitations measured in synchrotron experiments, with emphasis on the unique conditions absent in neutron scattering and arising in resonance scattering: prompt absorption, delayed emission, recoilfree transitions, and coherent forward scattering. The first moment sum rule normalizes the inelastic spectrum. Sum rules obtained for higher moments include the third moment proportional to the second derivative of the potential acting on the Moessbauer nucleus and independent of temperature in the harmonic approximation. Interesting information may be obtained on the behavior of the potential acting on this nucleus in samples not easily investigated with neutron scattering, e.g., small samples, thin films, time-dependent structures, and amorphous-metallic high pressure phases

QCD sum rule for nucleon in nuclear matter

International Nuclear Information System (INIS)

Mallik, S.; Sarkar, Sourav

2010-01-01

We consider the two-point function of nucleon current in nuclear matter and write a QCD sum rule to analyse the residue of the nucleon pole as a function of nuclear density. The nucleon self-energy needed for the sum rule is taken as input from calculations using phenomenological N N potential. Our result shows a decrease in the residue with increasing nuclear density, as is known to be the case with similar quantities. (orig.)

GDH sum rule measurement at low Q2

International Nuclear Information System (INIS)

Bianchi, N.

1996-01-01

The Gerasimov-Drell-Hearn (GDH) sum rule is based on a general dispersive relation for the forward Compton scattering. Multipole analysis suggested the possible violation of the sum rule. Some propositions have been made to modify the original GDH expression. An effort is now being made in several laboratories to shred some light on this topic. The purposes of the different planned experiments are briefly presented according to their Q 2 range

Charm photoproduction and quantum chromodynamics

International Nuclear Information System (INIS)

Novikov, V.A.; Shifman, M.A.; Vainshtein, A.I.; Zakharov, V.I.

1977-01-01

It is shown that charm photoproduction can be consistently described within asymptotically free field theory. Quantum chromodynamics is used to derive sum rules for the total cross section sigmasub(c)sup(γ) which includes both production of mesons with hidden charm (J/PIS, PIS' and so on) and of charmed particles (pairs DantiD, FantiF and so on). An estimate of sigmasub(c)sup(γ) as a function of energy is given and fast growth is discovered up to energies approximately 1000 GeV. In this energy range sigmasub(c)sup(γ) turns out to be equal to several microbarns. It is argued that measurements of charm photoproduction would give the most direct information on the gluon distribution within a nucleon. All the results are generalized to production of heavier particles containing new quarks. In particular, a simple rescaling law is derived connecting the cross sections for charm and beauty

Symbolic methods for the evaluation of sum rules of Bessel functions

International Nuclear Information System (INIS)

Babusci, D.; Dattoli, G.; Górska, K.; Penson, K. A.

2013-01-01

The use of the umbral formalism allows a significant simplification of the derivation of sum rules involving products of special functions and polynomials. We rederive in this way known sum rules and addition theorems for Bessel functions. Furthermore, we obtain a set of new closed form sum rules involving various special polynomials and Bessel functions. The examples we consider are relevant for applications ranging from plasma physics to quantum optics

Quantum chromodynamical calculations of meson wave functions in the light-cone formalism by means of QCD sum rules

International Nuclear Information System (INIS)

Guellenstern, S.

1991-09-01

Using the technique of Cherniak and Zhitnitzky we have calculated the wavefunctions of ρ(770) and Φ(1020) within the framework of QCD sum rules. Whereas the standard approach assumes light-like distances of the quarks (z 2 = 0), we also have taken into account higher order terms in z 2 . Thus, we obtained non-vanishing orbital angular momentum contributions. The first few moments of various invariant functions have been calculated with the help of an especially developed REDUCE program package. In zeroth order (z 2 = 0) our results of the reconstructed wavefunctions agree with those in the literature. However, we got first order contributions in z 2 of an amount of almost 10% of the corresponding zeroth order. (orig.)

B --> K$*\\gamma$ from hybrid sum rule

CERN Document Server

Narison, Stéphan

1994-01-01

Using the {\\it hybrid} moments-Laplace sum rule (HSR), which is well-defined for M_b \\rar \\infty, in contrast with the popular double Borel (Laplace) sum rule (DLSR), which blows up in this limit when applied to the heavy-to-light processes, we show that the form factor of the B \\rar K^* \\ \\gamma radiative transition is dominated by the light-quark condensate for M_b \\rar \\infty and behaves like \\sqrt M_b. The form factor is found to be F^{B\\rar K^*}_1(0) \\simeq (30.8 \\pm 1.3 \\pm 3.6 \\pm 0.6)\\times 10^{-2}, where the errors come respectively from the procedure in the sum rule analysis, the errors in the input and in the SU(3)_f-breaking parameters. This result leads to Br(B\\rar K^* \\ \\gamma) \\simeq (4.45 \\pm 1.12) \\times 10^{-5} in agreement with the recent CLEO data. Parametrization of the M_b-dependence of the form factor including the SU(3)_f-breaking effects is given in (26), which leads to F^{B\\rar K^*}_1(0)/ F^{B\\rar \\rho}_1(0) \\simeq (1.14 \\pm 0.02).

Neutrino mass sum rules and symmetries of the mass matrix

Energy Technology Data Exchange (ETDEWEB)

Gehrlein, Julia [Karlsruhe Institute of Technology, Institut fuer Theoretische Teilchenphysik, Karlsruhe (Germany); Universidad Autonoma de Madrid, Departamento de Fisica Teorica, Madrid (Spain); Instituto de Fisica Teorica UAM/CSIC, Madrid (Spain); Spinrath, Martin [Karlsruhe Institute of Technology, Institut fuer Theoretische Teilchenphysik, Karlsruhe (Germany); National Center for Theoretical Sciences, Physics Division, Hsinchu (China)

2017-05-15

Neutrino mass sum rules have recently gained again more attention as a powerful tool to discriminate and test various flavour models in the near future. A related question which has not yet been discussed fully satisfactorily was the origin of these sum rules and if they are related to any residual or accidental symmetry. We will address this open issue here systematically and find previous statements confirmed. Namely, the sum rules are not related to any enhanced symmetry of the Lagrangian after family symmetry breaking but they are simply the result of a reduction of free parameters due to skillful model building. (orig.)

Sum rules for quasifree scattering of hadrons

Science.gov (United States)

Peterson, R. J.

2018-02-01

The areas d σ /d Ω of fitted quasifree scattering peaks from bound nucleons for continuum hadron-nucleus spectra measuring d2σ /d Ω d ω are converted to sum rules akin to the Coulomb sums familiar from continuum electron scattering spectra from nuclear charge. Hadronic spectra with or without charge exchange of the beam are considered. These sums are compared to the simple expectations of a nonrelativistic Fermi gas, including a Pauli blocking factor. For scattering without charge exchange, the hadronic sums are below this expectation, as also observed with Coulomb sums. For charge exchange spectra, the sums are near or above the simple expectation, with larger uncertainties. The strong role of hadron-nucleon in-medium total cross sections is noted from use of the Glauber model.

Finite-width Gaussian sum rules for 0{sup -+} pseudoscalar glueball based on correction from instanton–gluon interference to correlation function

Energy Technology Data Exchange (ETDEWEB)

Wang, Feng; Chen, Junlong; Liu, Jueping, E-mail: jpliu@whu.edu.cn [Department of Physics, School of Physics Science and Technology, Wuhan University, 430072, Wuhan (China)

2015-09-28

Based on a correction from instanton–gluon interference to the correlation function, the properties of the 0{sup -+} pseudoscalar glueball are investigated in a family of finite-width Gaussian sum rules. In the framework of a semiclassical expansion for quantum chromodynamics in the instanton liquid background, the contribution arising from the interference between instantons and the quantum gluon fields is calculated, and it is included in the correlation function together with a pure-classical contribution from instantons and the perturbative one. The interference contribution turns out to be gauge-invariant, to be free from an infrared divergence, and to have a great role to play in restoring the positivity of the spectra of the full correlation function. The negligible contribution from vacuum condensates is excluded in our correlation function to avoid double counting. Instead of the usual zero-width approximation for the resonances, the usual Breit–Wigner form with a suitable threshold behavior for the spectral function of the finite-width resonances is adopted. Consistency between the subtracted and unsubtracted sum rules is very well justified. The values of the mass, decay width, and coupling constants for the 0{sup -+} resonance in which the glueball fraction is dominant are obtained, and they agree with the phenomenological analysis.

Finite-width Gaussian sum rules for 0{sup -+} pseudoscalar glueball based on correction from instanton-gluon interference to correlation function

Energy Technology Data Exchange (ETDEWEB)

Wang, Feng; Chen, Junlong; Liu, Jueping [Wuhan University, Department of Physics, School of Physics Science and Technology, Wuhan (China)

2015-09-15

Based on a correction from instanton-gluon interference to the correlation function, the properties of the 0{sup -+} pseudoscalar glueball are investigated in a family of finite-width Gaussian sum rules. In the framework of a semiclassical expansion for quantum chromodynamics in the instanton liquid background, the contribution arising from the interference between instantons and the quantum gluon fields is calculated, and it is included in the correlation function together with a pure-classical contribution from instantons and the perturbative one. The interference contribution turns out to be gauge-invariant, to be free from an infrared divergence, and to have a great role to play in restoring the positivity of the spectra of the full correlation function. The negligible contribution from vacuum condensates is excluded in our correlation function to avoid double counting. Instead of the usual zero-width approximation for the resonances, the usual Breit-Wigner form with a suitable threshold behavior for the spectral function of the finite-width resonances is adopted. Consistency between the subtracted and unsubtracted sum rules is very well justified. The values of the mass, decay width, and coupling constants for the 0{sup -+} resonance in which the glueball fraction is dominant are obtained, and they agree with the phenomenological analysis. (orig.)

Spectral sum rule for time delay in R2

International Nuclear Information System (INIS)

Osborn, T.A.; Sinha, K.B.; Bolle, D.; Danneels, C.

1985-01-01

A local spectral sum rule for nonrelativistic scattering in two dimensions is derived for the potential class velement ofL 4 /sup // 3 (R 2 ). The sum rule relates the integral over all scattering energies of the trace of the time-delay operator for a finite region Σis contained inR 2 to the contributions in Σ of the pure point and singularly continuous spectra

A Bayesian analysis of the nucleon QCD sum rules

International Nuclear Information System (INIS)

Ohtani, Keisuke; Gubler, Philipp; Oka, Makoto

2011-01-01

QCD sum rules of the nucleon channel are reanalyzed, using the maximum-entropy method (MEM). This new approach, based on the Bayesian probability theory, does not restrict the spectral function to the usual ''pole + continuum'' form, allowing a more flexible investigation of the nucleon spectral function. Making use of this flexibility, we are able to investigate the spectral functions of various interpolating fields, finding that the nucleon ground state mainly couples to an operator containing a scalar diquark. Moreover, we formulate the Gaussian sum rule for the nucleon channel and find that it is more suitable for the MEM analysis to extract the nucleon pole in the region of its experimental value, while the Borel sum rule does not contain enough information to clearly separate the nucleon pole from the continuum. (orig.)

Forward Compton scattering with weak neutral current: Constraints from sum rules

Directory of Open Access Journals (Sweden)

Mikhail Gorchtein

2015-07-01

Full Text Available We generalize forward real Compton amplitude to the case of the interference of the electromagnetic and weak neutral current, formulate a low-energy theorem, relate the new amplitudes to the interference structure functions and obtain a new set of sum rules. We address a possible new sum rule that relates the product of the axial charge and magnetic moment of the nucleon to the 0th moment of the structure function g5(ν,0. For the dispersive γZ-box correction to the proton's weak charge, the application of the GDH sum rule allows us to reduce the uncertainty due to resonance contributions by a factor of two. The finite energy sum rule helps addressing the uncertainty in that calculation due to possible duality violations.

Polarizability sum rules in QED

International Nuclear Information System (INIS)

Llanta, E.; Tarrach, R.

1978-01-01

The well founded total photoproduction and the, assumed subtraction free, longitudinal photoproduction polarizability sum rules are checked in QED at the lowest non-trivial order. The first one is shown to hold, whereas the second one turns out to need a subtraction, which makes its usefulness for determining the electromagnetic polarizabilities of the nucleons quite doubtful. (Auth.)

Chiral symmetry breaking parameters from QCD sum rules

Energy Technology Data Exchange (ETDEWEB)

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

1982-10-04

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

Quark-spin isospin sum rules and the Adler-Weisberger relation in nuclei

International Nuclear Information System (INIS)

Delorme, J.; Ericson, M.

1982-01-01

We use a quark model to extend the classical Gamow-Teller sum rule for the difference of the β - and β + strengths to excitations of the nucleon (mainly the Δ isobar). A schematic model illustrates the realization of the new sum rule when a particle-hole force is introduced. We discuss the connection of our result with the model-independent Adler-Weisberger sum rule. (orig.)

Pentaquarks in QCD Sum Rule Approach

International Nuclear Information System (INIS)

Rodrigues da Silva, R.; Matheus, R.D.; Navarra, F.S.; Nielsen, M.

2004-01-01

We estimate the mass of recently observed pentaquak staes Ξ- (1862) and Θ+(1540) using two kinds of interpolating fields, containing two highly correlated diquarks, in the QCD sum rule approach. We obtained good agreement with the experimental value, using standard continuum threshold

Comment on QCD sum rules and weak bottom decays

International Nuclear Information System (INIS)

Guberina, B.; Machet, B.

1982-07-01

QCD sum rules derived by Bourrely et al. are applied to B-decays to get a lower and an upper bound for the decay rate. The sum rules are shown to be essentially controlled by the large mass scales involved in the process. These bounds combined with the experimental value of BR (B→eνX) provide an upper bound for the lifetime of the B + meson. A comparison is made with D-meson decays

Lindhard's polarization parameter and atomic sum rules in the local plasma approximation

DEFF Research Database (Denmark)

Cabrera-Trujillo, R.; Apell, P.; Oddershede, J.

2017-01-01

In this work, we analyze the effects of Lindhard polarization parameter, χ, on the sum rule, Sp, within the local plasma approximation (LPA) as well as on the logarithmic sum rule Lp = dSp/dp, in both cases for the system in an initial excited state. We show results for a hydrogenic atom with nuc......In this work, we analyze the effects of Lindhard polarization parameter, χ, on the sum rule, Sp, within the local plasma approximation (LPA) as well as on the logarithmic sum rule Lp = dSp/dp, in both cases for the system in an initial excited state. We show results for a hydrogenic atom...... in terms of a screened charge Z* for the ground state. Our study shows that by increasing χ, the sum rule for p0 it increases, and the value p=0 provides the normalization/closure relation which remains fixed to the number of electrons for the same initial state. When p is fixed...

Faraday effect revisited: sum rules and convergence issues

DEFF Research Database (Denmark)

Cornean, Horia; Nenciu, Gheorghe

2010-01-01

This is the third paper of a series revisiting the Faraday effect. The question of the absolute convergence of the sums over the band indices entering the Verdet constant is considered. In general, sum rules and traces per unit volume play an important role in solid-state physics, and they give...

Magnetic susceptibility and M1 transitions in /sup 208/Pb. [Sum rules

Energy Technology Data Exchange (ETDEWEB)

Traini, M; Lipparini, E; Orlandini, G; Stringari, S [Dipartimento di Matematica e Fisica, Universita di Trento, Italy

1979-04-16

M1 transitions in /sup 208/Pb are studied by evaluating energy-weighted and inverse energy-weighted sum-rules. The role of the nuclear interaction is widely discussed. It is shown that the nuclear potential increases the energy-weighted sum rule and lowers the inverse energy-weighted sum rule, with respect to the prediction of the pure shell model. Values of strengths and excitation energies are compared with experimental results and other theoretical calculations.

Sum rules for the real parts of nonforward current-particle scattering amplitudes

International Nuclear Information System (INIS)

Abdel-Rahman, A.M.M.

1976-01-01

Extending previous work, using Taha's refined infinite-momentum method, new sum rules for the real parts of nonforward current-particle scattering amplitudes are derived. The sum rules are based on covariance, casuality, scaling, equal-time algebra and unsubtracted dispersion relations for the amplitudes. A comparison with the corresponding light-cone approach is made, and it is shown that the light-cone sum rules would also follow from the assumptions underlying the present work

Sum rules for baryonic vertex functions and the proton wave function in QCD

International Nuclear Information System (INIS)

Lavelle, M.J.

1985-01-01

We consider light-cone sum rules for vertex functions involving baryon-meson couplings. These sum rules relate the non-perturbative, and experimentally known, coupling constants to the moments of the wave function of the proton state. Our results for these moments are consistent with those obtained from QCD sum rules for two-point functions. (orig.)

A sum rule description of giant resonances at finite temperature

International Nuclear Information System (INIS)

Meyer, J.; Quentin, P.; Brack, M.

1983-01-01

A generalization of the sum rule approach to collective motion at finite temperature is presented. The m 1 and msub(-1) sum rules for the isovector dipole and the isoscalar monopole electric modes have been evaluated with the modified SkM force for the 208 Pb nucleus. The variation of the resulting giant resonance energies with temperature is discussed. (orig.)

QCD sum rule studies at finite density and temperature

Energy Technology Data Exchange (ETDEWEB)

Kwon, Youngshin

2010-01-21

In-medium modifications of hadronic properties have a strong connection to the restoration of chiral symmetry in hot and/or dense medium. The in-medium spectral functions for vector and axial-vector mesons are of particular interest in this context, considering the experimental dilepton production data which signal the in-medium meson properties. In this thesis, finite energy sum rules are employed to set constraints for the in-medium spectral functions of vector and axial-vector mesons. Finite energy sum rules for the first two moments of the spectral functions are investigated with emphasis on the role of a scale parameter related to the spontaneous chiral symmetry breaking in QCD. It is demonstrated that these lowest moments of vector current spectral functions do permit an accurate sum rule analysis with controlled inputs, such as the QCD condensates of lowest dimensions. In contrast, the higher moments contain uncertainties from the higher dimensional condensates. It turns out that the factorization approximation for the four-quark condensate is not applicable in any of the cases studied in this work. The accurate sum rules for the lowest two moments of the spectral functions are used to clarify and classify the properties of vector meson spectral functions in a nuclear medium. Possible connections with the Brown-Rho scaling hypothesis are also discussed. (orig.)

Sum rules for the spontaneous chiral symmetry breaking parameters of QCD

International Nuclear Information System (INIS)

Craigie, N.S.; Stern, J.

1981-03-01

We discuss in the spirit of the work of Shifman, Vainshtein and Zakharov (SVZ), sum rules involving current-current vacuum correlation functions, whose Wilson expansion starts off with the operators anti qq or (anti qq) 2 , and thus provide information about the chiral symmetry breaking parameters of QCD. We point out that under the type of crude approximations made by SVZ, a value of sub(vac) (250MeV) 3 is obtained from one of these sum rules, in agreement with current expectations. Further we show that a Borel transformed version of the Weinberg sum rule, for VV - AA, current products seem only to make sense for an A 1 mass close to 1.3GeV and it makes little sense with the current algebra mass Msub(A)=anti 2M. We also give an estimate for the chiral symmetry breaking parameters μ 1 6 =2 2 (anti qsub(L) lambda sup(a)γsub(μ)qsub(L))(anti qsub(R) lambdasup(a) γsup(μ)qsub(R)) >sub(vac) entering in the Weinberg sum rules and μ 2 6 =g 2 sub(vac) entering in a new sum rule we propose involving antisymmetric tensor currents J=anti q σsub(μnu) q. (author)

Dispersion relations and sum rules for natural optical activity

International Nuclear Information System (INIS)

Thomaz, M.T.; Nussenzveig, H.M.

1981-06-01

Dispersion relations and sum rules are derived for the complex rotatory power of an arbitrary linear (nonmagnetic) isotropic medium showing natural optical activity. Both previously known dispersion relations and sum rules as well as new ones are obtained. It is shown that the Rosenfeld-Condon dispersion formula is inconsistent with the expected asymptotic behavior at high frequencies. A new dispersion formula based on quantum eletro-dynamics removes this inconsistency; however, it still requires modification in the low-frequency limit. (Author) [pt

Sum rule approach to nuclear vibrations

International Nuclear Information System (INIS)

Suzuki, T.

1983-01-01

Velocity field of various collective states is explored by using sum rules for the nuclear current. It is shown that an irrotational and incompressible flow model is applicable to giant resonance states. Structure of the hydrodynamical states is discussed according to Tomonaga's microscopic theory for collective motions. (author)

Sum Rules of Charm CP Asymmetries beyond the SU(3)_{F} Limit.

Science.gov (United States)

Müller, Sarah; Nierste, Ulrich; Schacht, Stefan

2015-12-18

We find new sum rules between direct CP asymmetries in D meson decays with coefficients that can be determined from a global fit to branching ratio data. Our sum rules eliminate the penguin topologies P and PA, which cannot be determined from branching ratios. In this way, we can make predictions about direct CP asymmetries in the standard model without ad hoc assumptions on the sizes of penguin diagrams. We consistently include first-order SU(3)_{F} breaking in the topological amplitudes extracted from the branching ratios. By confronting our sum rules with future precise data from LHCb and Belle II, one will identify or constrain new-physics contributions to P or PA. The first sum rule correlates the CP asymmetries a_{CP}^{dir} in D^{0}→K^{+}K^{-}, D^{0}→π^{+}π^{-}, and D^{0}→π^{0}π^{0}. We study the region of the a_{CP}^{dir}(D^{0}→π^{+}π^{-})-a_{CP}^{dir}(D^{0}→π^{0}π^{0}) plane allowed by current data and find that our sum rule excludes more than half of the allowed region at 95% C.L. Our second sum rule correlates the direct CP asymmetries in D^{+}→K[over ¯]^{0}K^{+}, D_{s}^{+}→K^{0}π^{+}, and D_{s}^{+}→K^{+}π^{0}.

Renormalization group summation of Laplace QCD sum rules for scalar gluon currents

Directory of Open Access Journals (Sweden)

Farrukh Chishtie

2016-03-01

Full Text Available We employ renormalization group (RG summation techniques to obtain portions of Laplace QCD sum rules for scalar gluon currents beyond the order to which they have been explicitly calculated. The first two of these sum rules are considered in some detail, and it is shown that they have significantly less dependence on the renormalization scale parameter μ2 once the RG summation is used to extend the perturbative results. Using the sum rules, we then compute the bound on the scalar glueball mass and demonstrate that the 3 and 4-Loop perturbative results form lower and upper bounds to their RG summed counterparts. We further demonstrate improved convergence of the RG summed expressions with respect to perturbative results.

Phenomenological applications of perturbative quantum chromodynamics

International Nuclear Information System (INIS)

Zahir, M.S.Z.

1981-01-01

In this thesis, three diffrent topics in high energy particle physics are investigated each of which is a case of theoretical and phenomenological application of perturbative Quantum Chromodynamics. The first topic is addressed to the structure of nucleons as probed in deep-inelastic lepton-nucleon scattering. Since, at present, meaningful calculations in Quantum Chromodynamics (QCD) can be done only for short distances or large momentum transfers, phenomenological applications of QCD to the full hadronic processes many a time require additional model dependent procedures. In this thesis, the structure functions of the nucleon in the framework of the valon model in which a nucleon is assumed to be a bound state of three valence quark clusters (valons) are analyzed. In the second topic the production of massive dimuons at large transverse momentum in Drell-Yan process is analyzed where it is believed that the dimuons acquire large transverse momentum through the emission or absorption of hard gluons. Following a model independent formalism, in this thesis, the lowest order QCD contributions to the structure functions in lepton-pair production are calculated and it is shown that there exist sum rules connecting the four sructure functions to be satisfied at zero rapidity and large transverse momentum of the muon-pair for similar interacting hadrons. In the third topic a discussion is given on how high energy photons can replace hadrons in new lepton-pair production process

Hadronic final states and sum rules in deep inelastic processes

International Nuclear Information System (INIS)

Pal, B.K.

1977-01-01

In order to get maximum information on the hadronic final states and sum rules in deep inelastic processes, Regge phenomenology and quarks parton model have been used. The unified picture for the production of hadrons of type i as a function of Bjorken and Feyman variables with only one adjustable parameter is formulated. The results of neutrino experiments and the production of charm particles are discussed in sum rules. (author)

Derivation of sum rules for quark and baryon fields. [light-like charges

Energy Technology Data Exchange (ETDEWEB)

Bongardt, K [Karlsruhe Univ. (TH) (Germany, F.R.). Inst. fuer Theoretische Kernphysik

1978-08-21

In an analogous way to the Weinberg sum rules, two spectral-function sum rules for quark and baryon fields are derived by means of the concept of lightlike charges. The baryon sum rules are valid for the case of SU/sub 3/ as well as for SU/sub 4/ and the one-particle approximation yields a linear mass relation. This relation is not in disagreement with the normal linear GMO formula for the baryons. The calculated masses of the first resonance states agree very well with the experimental data.

Sum rules for four-spinon dynamic structure factor in XXX model

International Nuclear Information System (INIS)

Si Lakhal, B.; Abada, A.

2005-01-01

In the context of the antiferromagnetic spin 12 Heisenberg quantum spin chain (XXX model), we estimate the contribution of the exact four-spinon dynamic structure factor S 4 by calculating a number of sum rules the total dynamic structure factor S is known to satisfy exactly. These sum rules are: the static susceptibility, the integrated intensity, the total integrated intensity, the first frequency moment and the nearest-neighbor correlation function. We find that the contribution of S 4 is between 1% and 2.5%, depending on the sum rule, whereas the contribution of the exact two-spinon dynamic structure factor S 2 is between 70% and 75%. The calculations are numerical and Monte Carlo based. Good statistics are obtained

Dynamical local field, compressibility, and frequency sum rules for quasiparticles

International Nuclear Information System (INIS)

Morawetz, Klaus

2002-01-01

The finite temperature dynamical response function including the dynamical local field is derived within a quasiparticle picture for interacting one-, two-, and three-dimensional Fermi systems. The correlations are assumed to be given by a density-dependent effective mass, quasiparticle energy shift, and relaxation time. The latter one describes disorder or collisional effects. This parametrization of correlations includes local-density functionals as a special case and is therefore applicable for density-functional theories. With a single static local field, the third-order frequency sum rule can be fulfilled simultaneously with the compressibility sum rule by relating the effective mass and quasiparticle energy shift to the structure function or pair-correlation function. Consequently, solely local-density functionals without taking into account effective masses cannot fulfill both sum rules simultaneously with a static local field. The comparison to the Monte Carlo data seems to support such a quasiparticle picture

QCD and power corrections to sum rules in deep-inelastic lepton-nucleon scattering

International Nuclear Information System (INIS)

Ravindran, V.; Neerven, W.L. van

2001-01-01

In this paper we study QCD and power corrections to sum rules which show up in deep-inelastic lepton-hadron scattering. Furthermore we will make a distinction between fundamental sum rules which can be derived from quantum field theory and those which are of a phenomenological origin. Using current algebra techniques the fundamental sum rules can be expressed into expectation values of (partially) conserved (axial-)vector currents sandwiched between hadronic states. These expectation values yield the quantum numbers of the corresponding hadron which are determined by the underlying flavour group SU(n) F . In this case one can show that there exist an intimate relation between the appearance of power and QCD corrections. The above features do not hold for phenomenological sum rules, hereafter called non-fundamental. They have no foundation in quantum field theory and they mostly depend on certain assumptions made for the structure functions like super-convergence relations or the parton model. Therefore only the fundamental sum rules provide us with a stringent test of QCD

Second-moment sum rules for correlation functions in a classical ionic mixture

NARCIS (Netherlands)

Suttorp, L.G.; Ebeling, W.

1992-01-01

The complete set of second-moment sum rules for the correlation functions of arbitrarily high order describing a classical multi-component ionic mixture in equilibrium is derived from the grand-canonical ensemble. The connection of these sum rules with the large-scale behaviour of fluctuations in an

Introduction to non-perturbative quantum chromodynamics; Introduction a QCD non perturbatif

Energy Technology Data Exchange (ETDEWEB)

Pene, O. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique et Hautes Energies

1995-12-31

Quantum chromodynamics is considered to be the theory of strong interaction. The main peculiarity of this theory is that its asymptotic states (hadrons) are different from its elementary fields (quarks and gluons). This property plays a great part in any physical process involving small momentum-energy transfers. In such a range perturbative methods are no longer allowed. This work focuses on other tools such as QCD symmetry, the quark model, Green functions and the sum rules. To get hadron characteristics numerically, QCD on lattices is used but only in the case of simple process involving no more than one hadron in the initial and final states because of the complexity of the Green function. Some examples using a Monte-Carlo simulation are given. (A.C.) 39 refs.

Sum rule limitations of kinetic particle-production models

International Nuclear Information System (INIS)

Knoll, J.; CEA Centre d'Etudes Nucleaires de Grenoble, 38; Guet, C.

1988-04-01

Photoproduction and absorption sum rules generalized to systems at finite temperature provide a stringent check on the validity of kinetic models for the production of hard photons in intermediate energy nuclear collisions. We inspect such models for the case of nuclear matter at finite temperature employed in a kinetic regime which copes those encountered in energetic nuclear collisions, and find photon production rates which significantly exceed the limits imposed by the sum rule even under favourable concession. This suggests that coherence effects are quite important and the production of photons cannot be considered as an incoherent addition of individual NNγ production processes. The deficiencies of present kinetic models may also apply for the production of probes such as the pion which do not couple perturbatively to the nuclear currents. (orig.)

Continuum contributions to dipole oscillator-strength sum rules for hydrogen in finite basis sets

DEFF Research Database (Denmark)

Oddershede, Jens; Ogilvie, John F.; Sauer, Stephan P. A.

2017-01-01

Calculations of the continuum contributions to dipole oscillator sum rules for hydrogen are performed using both exact and basis-set representations of the stick spectra of the continuum wave function. We show that the same results are obtained for the sum rules in both cases, but that the conver......Calculations of the continuum contributions to dipole oscillator sum rules for hydrogen are performed using both exact and basis-set representations of the stick spectra of the continuum wave function. We show that the same results are obtained for the sum rules in both cases......, but that the convergence towards the final results with increasing excitation energies included in the sum over states is slower in the basis-set cases when we use the best basis. We argue also that this conclusion most likely holds also for larger atoms or molecules....

In-medium QCD sum rules for {omega} meson, nucleon and D meson

Energy Technology Data Exchange (ETDEWEB)

Thomas, Ronny

2008-07-01

The modifications of hadronic properties caused by an ambient nuclear medium are investigated within the scope of QCD sum rules. This is exemplified for the cases of the {omega} meson, the nucleon and the D meson. By virtue of the sum rules, integrated spectral densities of these hadrons are linked to properties of the QCD ground state, quantified in condensates. For the cases of the {omega} meson and the nucleon it is discussed how the sum rules allow a restriction of the parameter range of poorly known four-quark condensates by a comparison of experimental and theoretical knowledge. The catalog of independent four-quark condensates is covered and relations among these condensates are revealed. The behavior of four-quark condensates under the chiral symmetry group and the relation to order parameters of spontaneous chiral symmetry breaking are outlined. In this respect, also the QCD condensates appearing in differences of sum rules of chiral partners are investigated. Finally, the effects of an ambient nuclear medium on the D meson are discussed and relevant condensates are identified. (orig.)

Bulk stress auto-correlation function in simple liquids-sum rules

International Nuclear Information System (INIS)

Tankeshwar, K.; Bhandari, R.; Pathak, K.N.

1990-10-01

Expressions for the zeroth, second and fourth frequency sum rules of the bulk stress auto correlation function have been derived. The exact expressions involve static correlation function up to four particles. Because of the non availability of any information about static quadruplet correlation function we use a low order decoupling approximation for this. In this work, we have obtained, separately, the sum rules for the different mechanism of momentum transfer in the fluids. The results are expected to be useful in the study of bulk viscosity of the fluids. (author). 9 refs

Endpoint behavior of the pion distribution amplitude in QCD sum rules with nonlocal condensates

International Nuclear Information System (INIS)

Mikhailov, S. V.; Pimikov, A. V.; Stefanis, N. G.

2010-01-01

Starting from the QCD sum rules with nonlocal condensates for the pion distribution amplitude, we derive another sum rule for its derivative and its ''integral derivatives''--defined in this work. We use this new sum rule to analyze the fine details of the pion distribution amplitude in the endpoint region x∼0. The results for endpoint-suppressed and flattop (or flatlike) pion distribution amplitudes are compared with those we obtained with differential sum rules by employing two different models for the distribution of vacuum-quark virtualities. We determine the range of values of the derivatives of the pion distribution amplitude and show that endpoint-suppressed distribution amplitudes lie within this range, while those with endpoint enhancement--flat-type or Chernyak-Zhitnitsky like--yield values outside this range.

The Relation between the Electric Conductance of Nanostructure Bridge and Friedel Sum Rule

International Nuclear Information System (INIS)

Kotani, Y; Shima, N; Makoshi, K

2012-01-01

We analyze the electric conductance through nanostructure bridges in terms of phase-shifts, which satisfy the Friedel sum rule. The phase-shifts are given by solving the eigenvalue equation obtained by extending the method applied to a single impurity problem in a metal. The local charge neutrality condition is introduced through the Friedel sum rule. It is analytically shown that the electric conductance can increase as the two electrodes separate with the condition in which the phase-shifts satisfy the Friedel sum rule. The increment of the distance between two electrodes is obtained by gradually separating interatomic distance.

Evaluating chiral symmetry restoration through the use of sum rules

Directory of Open Access Journals (Sweden)

Rapp Ralf

2012-11-01

Full Text Available We pursue the idea of assessing chiral restoration via in-medium modifications of hadronic spectral functions of chiral partners. The usefulness of sum rules in this endeavor is illustrated, focusing on the vector/axial-vector channel. We first present an update on obtaining quantitative results for pertinent vacuum spectral functions. These serve as a basis upon which the in-medium spectral functions can be constructed. A novel feature of our analysis of the vacuum spectral functions is the need to include excited resonances, dictated by satisfying the Weinberg-type sum rules. This includes excited states in both the vector and axial-vector channels.We also analyze the QCD sum rule for the finite temperature vector spectral function, based on a ρ spectral function tested in dilepton data which develops a shoulder at low energies.We find that the ρ′ peak flattens off which may be a sign of chiral restoration, though a study of the finite temperature axial-vector spectral function remains to be carried out.

Calculation of baryon sum rules and SU(4) mass formulae for mesons and baryons

International Nuclear Information System (INIS)

Bongardt, K.

1976-01-01

Light cone coordinates and field-field anticommutators for the free quark model on the light cone are introduced and light cone charges and light cone currents for the free quark model as well as sum rules for the meson and quark states are derived. The derivation of sum rules for the baryons is attempted. It is seen that it is possible formally to derive the same sum rules for the baryons and for the quarks. The baryon sums were derived through the symmetry properties of the baryon fields. Explicit assumptions about the spatial distribution of the three quarks in the baryons were not utilized. The meson-baryon Σ-terms, Zweig's rules in the SU (4) and a number of properties of the M-matrix are discussed. (BJ) [de

Slave-particle quantization and sum rules in the t-J model

International Nuclear Information System (INIS)

Le Guillou, J.C.; Ragoucy, E.

1994-12-01

In the framework of constrained systems, the classical Hamiltonian formulation of slave-particle models and their correct quantization are given. The electron-momentum distribution function in the t-J and Hubbard models is then studied in the framework of slave-particle approaches and within the decoupling scheme. It is shown that criticisms which have been addressed in this context coming from a violation of the sum rule for the physical electron are not valid. Due to the correct quantization rules for the slave-particles, the sum rule for the physical electron is indeed obeyed, both exactly and within the decoupling scheme. (author). 15 refs

Sum rules and moments for lepton-pair production. [Cross sections, Drell--Yan formula

Energy Technology Data Exchange (ETDEWEB)

Hwa, R.C.

1978-01-01

Sum rules on lepton-pair production cross sections are derived on the bases of the Drell--Yan formula and the known sum rules in leptoproduction. Also exact relations are obtained between the average transverse momenta squared of the valence quarks and moments of the dilepton cross sections. 12 references.

Sum Rules in the CFL Phase of QCD at finite density

CERN Document Server

Manuel, C; Manuel, Cristina; Tytgat, Michel H.G.

2001-01-01

We study the asymmetry between the vector current and axial-vector current correlators in the colour-flavour locking (CFL) phase of QCD at finite density. Using Weinberg's sum rules, we compute the decay constant $f_\\pi$ of the Goldstone modes and find agreement with previous derivations. Using Das's sum rule, we also estimate the contribution of electromagnetic interactions to the mass of the charged modes. Finally, we comment on low temperature corrections to the effective field theory describing the Goldstone bosons.

General solution of superconvergent sum rules for scattering of I=1 reggeons on baryons

International Nuclear Information System (INIS)

Grigoryan, A.A.; Khachatryan, G.N.

1986-01-01

Superconvergent sum rules for reggeon-particle scattering are applied to scattering of reggeons α i (i=π, ρ, A 2 ) with isospin I=1 on baryons with strangeness S=-1. The saturation scheme of these sum rules is determined on the basis of experimental data. Two series of baryon resonances with arbitrary isospins I and spins J=I+1/2 and J=I-1/2 are predicted. A general solution for vertices of interaction of these resonances with α i is found. Predictions for coupling vertices B α i B'(B, B'=Λ, Σ, Σ * ) agree well with the experiment. It is shown that the condition of sum rules saturation by minimal number of resonances brings to saturation schemes resulting from experimental data. A general solution of sum rules for scattering of α i reggeons on Ξ and Ω hyperons is analyzed

What can we learn from sum rules for vertex functions in QCD

International Nuclear Information System (INIS)

Craigie, N.S.; Stern, J.

1982-04-01

We demonstrate that the light cone sum rules for vertex functions based on the operator product expansion and QCD perturbation theory lead to interesting relationships between various non-perturbative parameters associated with hadronic bound states (e.g. vertex couplings and decay constants). We also show that such sum rules provide a valuable means of estimating the matrix elements of the higher spin operators in the meson wave function. (author)

Chiral restoration and the extended photoabsorption sum rule in nuclei

International Nuclear Information System (INIS)

Ericson, M.; Rosa-Clot, M.; Kulagin, S.A.

1996-07-01

The Bethe-Levinger sum rule is extended beyond the potential model. The pion degrees of freedom are taken into account and the modifications of the potential theory are analyzed within two different approaches: dipole sum rule and dispersion relation on the Compton amplitude. Our aim is to extract from the photon data experimental information on the expectation value of the square of the pion field, a quantity which enters also in the restoration of chiral symmetry in nuclei and in pion-nucleus scattering. We are led to incorporate in the description the Δ resonance, which is strongly excited by the pion degrees of freedom

Chiral restoration and the extended photoabsorption sum rule in nuclei

Energy Technology Data Exchange (ETDEWEB)

Ericson, M [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; [European Organization for Nuclear Research, Geneva (Switzerland); Rosa-Clot, M [Florence Univ. (Italy). Ist. di Fisica; [Istituto Nazionale di Fisica Nucleare, Florence (Italy); Kulagin, S A [Akademiya Meditsinskikh Nauk SSSR, Moscow (Russian Federation)

1996-07-01

The Bethe-Levinger sum rule is extended beyond the potential model. The pion degrees of freedom are taken into account and the modifications of the potential theory are analyzed within two different approaches: dipole sum rule and dispersion relation on the Compton amplitude. Our aim is to extract from the photon data experimental information on the expectation value of the square of the pion field, a quantity which enters also in the restoration of chiral symmetry in nuclei and in pion-nucleus scattering. We are led to incorporate in the description the {Delta} resonance, which is strongly excited by the pion degrees of freedom. 11 refs.

QCD sum rules for the decay amplitudes of pseudoscalar mesons

International Nuclear Information System (INIS)

Narison, S.

1981-07-01

Bounds on the π and K meson decay amplitudes are obtained to a good accuracy from QCD sum rules of the Laplace transform type. A relation between fsub(π) and the rho meson coupling to the photon is given. Using the heavy quarks q 2 =0 sum rule to two loops we find our best bounds: fsub(D) approximately < (101+-25) MeV and fsub(F) approximately < (147+-41.6) MeV to be compared to fsub(π) approximately 93.3 MeV. We also derive a relation between the D and F meson masses and the charm quark mass. Our results are extended to the beautiful B mesons. (author)

Charmonium spectrum at finite temperature from a Bayesian analysis of QCD sum rules

Directory of Open Access Journals (Sweden)

Morita Kenji

2012-02-01

Full Text Available Making use of a recently developed method of analyzing QCD sum rules, we investigate charmonium spectral functions at finite temperature. This method employs the Maximum Entropy Method, which makes it possible to directly obtain the spectral function from the sum rules, without having to introduce any strong assumption about its functional form. Finite temperature effects are incorporated into the sum rules by the change of the various gluonic condensates that appear in the operator product expansion. These changes depend on the energy density and pressure at finite temperature, which are extracted from lattice QCD. As a result, J/ψ and ηc dissolve into the continuum already at temperatures around 1.0 ~ 1.1 Tc.

Bottom mass from nonrelativistic sum rules at NNLL

Energy Technology Data Exchange (ETDEWEB)

Stahlhofen, Maximilian

2013-01-15

We report on a recent determination of the bottom quark mass from nonrelativistic (large-n) {Upsilon} sum rules with renormalization group improvement (RGI) at next-to-next-to-leading logarithmic (NNLL) order. The comparison to previous fixed-order analyses shows that the RGI computed in the vNRQCD framework leads to a substantial stabilization of the theoretical sum rule moments with respect to scale variations. A single moment fit (n=10) to the available experimental data yields M{sub b}{sup 1S}=4.755{+-}0.057{sub pert}{+-}0.009{sub {alpha}{sub s}}{+-}0.003{sub exp} GeV for the bottom 1S mass and anti m{sub b}(anti m{sub b})=4.235{+-}0.055{sub pert}{+-}0.003{sub exp} GeV for the bottom MS mass. The quoted uncertainties refer to the perturbative error and the uncertainties associated with the strong coupling and the experimental input.

The heat current density correlation function: sum rules and thermal conductivity

International Nuclear Information System (INIS)

Singh, Shaminder; Tankeshwar, K; Pathak, K N; Ranganathan, S

2006-01-01

Expressions for the second and fourth sum rules of the heat current density correlation function have been derived in an appropriate ensemble. The thermal conductivity of Lennard-Jones fluids has been calculated using these sum rules for the heat current density correlation function and the Gaussian form of the memory function. It is found that the results obtained for the thermal conductivity are in good agreement with the molecular dynamics simulation results over a wide range of densities and temperatures. Earlier results obtained using the energy current density correlation function are also discussed

The heat current density correlation function: sum rules and thermal conductivity

Energy Technology Data Exchange (ETDEWEB)

Singh, Shaminder [Department of Physics, Panjab University, Chandigarh-160 014 (India); Tankeshwar, K [Department of Physics, Panjab University, Chandigarh-160 014 (India); Pathak, K N [Department of Physics, Panjab University, Chandigarh-160 014 (India); Ranganathan, S [Department of Physics, Royal Military College, Kingston, ON, K7K 7B4 (Canada)

2006-02-01

Expressions for the second and fourth sum rules of the heat current density correlation function have been derived in an appropriate ensemble. The thermal conductivity of Lennard-Jones fluids has been calculated using these sum rules for the heat current density correlation function and the Gaussian form of the memory function. It is found that the results obtained for the thermal conductivity are in good agreement with the molecular dynamics simulation results over a wide range of densities and temperatures. Earlier results obtained using the energy current density correlation function are also discussed.

The Adler sum rule and quark parton distribution functions in nucleon

International Nuclear Information System (INIS)

Niegawa, Akira; Sasaki, Ken.

1975-01-01

The behaviour of the quark parton distribution functions is discussed through the phenomenological analysis of the deep inelastic e-p and e-n data under constraint of the saturation of the Adler sum rule. It is concluded that in the region 0 0 where the Regge parametrization can be applied, anti u(x) is equal to anti d(x), and both behave as const/x, (x 0 will be 0.04--0.05); for x 0 x 0 is given. The rate of convergence of the Adler sum rule is also discussed. (auth.)

Analysis of QCD sum rule based on the maximum entropy method

International Nuclear Information System (INIS)

Gubler, Philipp

2012-01-01

QCD sum rule was developed about thirty years ago and has been used up to the present to calculate various physical quantities like hadrons. It has been, however, needed to assume 'pole + continuum' for the spectral function in the conventional analyses. Application of this method therefore came across with difficulties when the above assumption is not satisfied. In order to avoid this difficulty, analysis to make use of the maximum entropy method (MEM) has been developed by the present author. It is reported here how far this new method can be successfully applied. In the first section, the general feature of the QCD sum rule is introduced. In section 2, it is discussed why the analysis by the QCD sum rule based on the MEM is so effective. In section 3, the MEM analysis process is described, and in the subsection 3.1 likelihood function and prior probability are considered then in subsection 3.2 numerical analyses are picked up. In section 4, some cases of applications are described starting with ρ mesons, then charmoniums in the finite temperature and finally recent developments. Some figures of the spectral functions are shown. In section 5, summing up of the present analysis method and future view are given. (S. Funahashi)

Beautiful mesons from QCD spectral sum rules

International Nuclear Information System (INIS)

Narison, S.

1991-01-01

We discuss the beautiful meson from the point of view of the QCD spectral sum rules (QSSR). The bottom quark mass and the mixed light quark-gluon condensates are determined quite accurately. The decay constant f B is estimated and we present some arguments supporting this result. The decay constants and the masses of the other members of the beautiful meson family are predicted. (orig.)

Limiting law excess sum rule for polyelectrolytes.

Science.gov (United States)

Landy, Jonathan; Lee, YongJin; Jho, YongSeok

2013-11-01

We revisit the mean-field limiting law screening excess sum rule that holds for rodlike polyelectrolytes. We present an efficient derivation of this law that clarifies its region of applicability: The law holds in the limit of small polymer radius, measured relative to the Debye screening length. From the limiting law, we determine the individual ion excess values for single-salt electrolytes. We also consider the mean-field excess sum away from the limiting region, and we relate this quantity to the osmotic pressure of a dilute polyelectrolyte solution. Finally, we consider numerical simulations of many-body polymer-electrolyte solutions. We conclude that the limiting law often accurately describes the screening of physical charged polymers of interest, such as extended DNA.

Lorentz-Lorenz quenching for the Gamow-Teller sum rule

International Nuclear Information System (INIS)

Delorme, J.; Ericson, M.; Figureau, A.

1984-03-01

We investigate the modification of the Gamow-Teller sum rule brought in by nucleonic excitations. The general trend of the data is well reproduced. The value of the force which mixes nucleonic and nuclear excitations is discussed

Confinement Can Violate Momentum Sum Rule in QCD at High Energy Colliders

OpenAIRE

Nayak, Gouranga C

2018-01-01

Momentum sum rule in QCD is widely used at high energy colliders. Although the exact form of the confinement potential energy is not known but the confinement potential energy at large distance $r$ can not rise slower than ${\\rm ln}(r)$. In this paper we find that if the confinement potential energy at large distance $r$ rises linearly with $r$ (or faster) then the momentum sum rule in QCD is violated at the high energy colliders.

The black hole interior and a curious sum rule

International Nuclear Information System (INIS)

Giveon, Amit; Itzhaki, Nissan; Troost, Jan

2014-01-01

We analyze the Euclidean geometry near non-extremal NS5-branes in string theory, including regions beyond the horizon and beyond the singularity of the black brane. The various regions have an exact description in string theory, in terms of cigar, trumpet and negative level minimal model conformal field theories. We study the worldsheet elliptic genera of these three superconformal theories, and show that their sum vanishes. We speculate on the significance of this curious sum rule for black hole physics

The black hole interior and a curious sum rule

Energy Technology Data Exchange (ETDEWEB)

Giveon, Amit [Racah Institute of Physics, The Hebrew University,Jerusalem, 91904 (Israel); Itzhaki, Nissan [Physics Department, Tel-Aviv University,Ramat-Aviv, 69978 (Israel); Troost, Jan [Laboratoire de Physique Théorique,Unité Mixte du CRNS et de l’École Normale Supérieure,associée à l’Université Pierre et Marie Curie 6,UMR 8549 École Normale Supérieure,24 Rue Lhomond Paris 75005 (France)

2014-03-12

We analyze the Euclidean geometry near non-extremal NS5-branes in string theory, including regions beyond the horizon and beyond the singularity of the black brane. The various regions have an exact description in string theory, in terms of cigar, trumpet and negative level minimal model conformal field theories. We study the worldsheet elliptic genera of these three superconformal theories, and show that their sum vanishes. We speculate on the significance of this curious sum rule for black hole physics.

Sum rules in extended RPA theories

International Nuclear Information System (INIS)

Adachi, S.; Lipparini, E.

1988-01-01

Different moments m k of the excitation strength function are studied in the framework of the second RPA and of the extended RPA in which 2p2h correlations are explicitly introduced into the ground state by using first-order perturbation theory. Formal properties of the equations of motion concerning sum rules are derived and compared with those exhibited by the usual 1p1h RPA. The problem of the separation of the spurious solutions in extended RPA calculations is also discussed. (orig.)

Sum rules for charge transition density

Energy Technology Data Exchange (ETDEWEB)

Gul' karov, I S [Tashkentskij Politekhnicheskij Inst. (USSR)

1979-01-01

The form factors of the quadrupole and octupole oscillations of the /sup 12/C nucleus are compared with the predictions of the sum rules for the charge transition density (CTD). These rules allow one to obtain various CTDs which contain the components k: r/sup lambda + 2k-2/rho(r) and r/sup lambda + 2k-1)(drho(r)/dr) (k = 0, 1, 2...) and can be applied to analyze the inelastic scattering of high energy particles by nuclei. It is shown that the CTD under consideration have different radius dependence and describe the data essentially better (though ambiguously) than the Tassy and Steinwedel-Jensen models do. Recurrence formulas are derived for the ratios of the higher-order transition matrix elements and CTD. These formulas can be used to predict the CTD behavior for highly excited nuclear states.

Singlet axial constant from QCD sum rules

International Nuclear Information System (INIS)

Belitskij, A.V.; Teryaev, O.V.

1995-01-01

We analyze the singlet axial form factor of the proton for small momentum transferred in the framework of QCD sum rules using the interpolating nucleon current which explicitly accounts for the gluonic degrees of freedom. As the result we come to the quantitative prediction of the singlet axial constant. It is shown that the bilocal power corrections play the most important role in the analysis. 21 refs., 3 figs

A self-consistent semiclassical sum rule approach to the average properties of giant resonances

International Nuclear Information System (INIS)

Li Guoqiang; Xu Gongou

1990-01-01

The average energies of isovector giant resonances and the widths of isoscalar giant resonances are evaluated with the help of a self-consistent semiclassical Sum rule approach. The comparison of the present results with the experimental ones justifies the self-consistent semiclassical sum rule approach to the average properties of giant resonances

O(N) symmetries, sum rules for generalized Hermite polynomials and squeezed states

International Nuclear Information System (INIS)

Daboul, Jamil; Mizrahi, Salomon S

2005-01-01

Quantum optics has been dealing with coherent states, squeezed states and many other non-classical states. The associated mathematical framework makes use of special functions as Hermite polynomials, Laguerre polynomials and others. In this connection we here present some formal results that follow directly from the group O(N) of complex transformations. Motivated by the squeezed states structure, we introduce the generalized Hermite polynomials (GHP), which include as particular cases, the Hermite polynomials as well as the heat polynomials. Using generalized raising operators, we derive new sum rules for the GHP, which are covariant under O(N) transformations. The GHP and the associated sum rules become useful for evaluating Wigner functions in a straightforward manner. As a byproduct, we use one of these sum rules, on the operator level, to obtain raising and lowering operators for the Laguerre polynomials and show that they generate an sl(2, R) ≅ su(1, 1) algebra

Sum rule approach to the nuclear response in the isovector spin channel

International Nuclear Information System (INIS)

Alberico, W.M.; Ericson, M.; Molinari, A.

1982-01-01

We study the global features of the response of infinite nuclear matter in the spin-isospin channel through the energy weighted sum rules S 1 and Ssub(-) 1 . In particular we compare the outcome of the ring approximation with the exact RPA evaluation of the sum rules. We also investigate the influence of the collective character of the response, induced by the particle hole force for a longitudinal and transverse spin couplings. We show that S 1 is insensitive to the collectivity of the response, as long as the Δ degree of freedom is ignored. The inverse energy weighted sum rule on the other hand, which is linked to the paramagnetic susceptibility, always reflects the hardening or softening of the nuclear response, due to the repulsive or attractive character of the p-h force. This quantity is well suited to the comparison with the experiments, which we perform for 12 C and 56 Fe. (orig.)

Spectral representation and QCD sum rules in hot nuclear matter

International Nuclear Information System (INIS)

Mallik, S.; Sarkar, Sourav

2009-01-01

We construct the spectral representation of spinsor two-point functions in medium, that is, at finite temperature and chemical potential. We first deal with the free spinor two-point function. Then we construct the same for interacting fields leading to the Kaellen-Lehmann representation. It is emphasised that although these two point functions have the structure of 2 x 2 matrices in the real time formulation of field theory, any one component actually suffices to describe the dynamics of the system. Our construction is then applied to write the QCD sum rules for two-point function of nucleon currents in medium. We discuss a subtracted version to increase the sensitivity of such a sum rule and point out how it differs from a conventional one. (author)

Parton model (Moessbauer) sum rules for b → c decays

International Nuclear Information System (INIS)

Lipkin, H.J.

1993-01-01

The parton model is a starting point or zero-order approximation in many treatments. The author follows an approach previously used for the Moessbauer effect and shows how parton model sum rules derived for certain moments of the lepton energy spectrum in b → c semileptonic decays remain valid even when binding effects are included. The parton model appears as a open-quote semiclassical close-quote model whose results for certain averages also hold (correspondence principle) in quantum mechanics. Algebraic techniques developed for the Moessbauer effect exploit simple features of the commutator between the weak current operator and the bound state Hamiltonian to find the appropriate sum rules and show the validity of the parton model in the classical limit, ℎ → 0, where all commutators vanish

Sum-rule analysis of long-wavelength excitations in electron liquids

International Nuclear Information System (INIS)

Ichimaru, Setsuo; Totsuji, Hiroo; Tange, Toshio; Pines, D.

1975-01-01

The properties of the plasma oscillations, the single-particle excitations and the collisional excitations in the classical one-component plasma are investigated in the long-wave-length domain with the aid of moment sum rules. The frequency moments of the dynamic form factor are calculated up to that term which involves the ternary correlation function. The dispersion in the plasma-wave frequency and the strengths of the single-particle and collisional excitations are computed over the thermodynamically stable domain of the plasma parameter, epsilon<=10. It is emphasized that inclusion of the collisional excitations plays a vital part in satisfying various moment-sum rules and in securing agreement with known boundary conditions such as the Vlasov description and molecular-dynamics computations. (auth.)

Experimental check of the GDH sum rule at MAMI and ELSA

International Nuclear Information System (INIS)

Krimmer, J.

2002-01-01

The experimental check of the GDH sum rule is being performed at the tagged photon facilities of the electron accelerators MAMI (Mainz) and ELSA (Bonn), using circularly polarized photons impinging on a longitudinally polarized proton target, together with detector systems covering almost the whole solid angle range. Results from the MAMI experiment for the double polarized total photoabsorption cross section in the low energy region (200 MeV < Eγ < 800 MeV) will be shown together with their contribution to the GDH sum rule. Furthermore first results from the ELSA experiment in the higher energy region (680 MeV < Eγ < 1900 MeV) will be presented

Light Cone Sum Rules for gamma*N ->Delta Transition Form Factors

Energy Technology Data Exchange (ETDEWEB)

V.M. Braun; A. Lenz; G. Peters; A. Radyushkin

2006-02-01

A theoretical framework is suggested for the calculation of {gamma}* N {yields} {Delta} transition form factors using the light-cone sum rule approach. Leading-order sum rules are derived and compared with the existing experimental data. We find that the transition form factors in a several GeV region are dominated by the ''soft'' contributions that can be thought of as overlap integrals of the valence components of the hadron wave functions. The ''minus'' components of the quark fields contribute significantly to the result, which can be reinterpreted as large contributions of the quark orbital angular momentum.

Λ-bar from QCD sum rules for heavy quarkonium

International Nuclear Information System (INIS)

Kiselev, V.V.

1994-01-01

Using a specific scheme of the QCD sum rules for heavy quarkonium int he leading approximation over the inverse heavy quark, one gets the estimate of the difference between the masses of the heavy meson and heavy quark Λ=o.59+-0.02 GeV. 10 refs

Detailed quantum-chromodynamic predictions for high-p/sub T/ processes

CERN Document Server

Owens, J F; Reya, E

1978-01-01

High-p/sub T/ single-particle inclusive cross section calculations are presented for the CERN ISR and ISABELLE energy ranges, taking into account all lowest-order hard-scattering subprocesses required by quantum chromodynamics (QCD). The input quark and gluon distribution and fragmentation functions were determined from analyses of deep- inelastic lepton data and were subject to various theoretical constraints such as sum rules and SU(3) symmetry. The authors thoroughly discuss the effects of the individual contributions from fermionic and gluonic subprocesses, as well as those effects stemming from QCD scaling violations in parton distributions and/or fragmentation functions. In particular, the inclusion of the large elastic gluon-gluon and gluon-quark scattering terms has a profound effect on both the normalization and the p/sub T/ dependence of the predictions. The p/sub T/ and theta dependences of single- pi /sup 0/ production are shown to be in good agreement with available data in the region p/sub T/>or...

Uses of dipole oscillator strength sum rules in second order perturbation theory

International Nuclear Information System (INIS)

Struensee, M.C.

1984-01-01

Certain moments of the dipole oscillator strength distribution of atoms and molecules can be calculated from theory (using sum rules) or deduced from experiment. The present work describes the use of these moments to construct effective distributions which lead to bounds and estimates of physical properties of interest. Asymptotic analysis is then used to obtain the high energy behavior of the oscillator strength density and a previously unknown sum rule for atoms and molecules. A new type of effective distribution, which incorporates the information concerning the asymptotic behavior and the new sum rule, is suggested. This new type of distribution is used to calculate the logarithmic mean excitation energies for the ground states of atomic hydrogen, atomic helium and the negative hydrogen ion. The calculations for atomic helium and the negative hydrogen ion require the evaluation of certain ground state expectation values. These have been calculated using high accuracy wavefunctions containing the nonconventional terms shown by Fock to be necessary for a correct analytic expansion when both electrons are near the nucleus

The Bethe Sum Rule and Basis Set Selection in the Calculation of Generalized Oscillator Strengths

DEFF Research Database (Denmark)

Cabrera-Trujillo, Remigio; Sabin, John R.; Oddershede, Jens

1999-01-01

Fulfillment of the Bethe sum rule may be construed as a measure of basis set quality for atomic and molecular properties involving the generalized oscillator strength distribution. It is first shown that, in the case of a complete basis, the Bethe sum rule is fulfilled exactly in the random phase...

Large-Nc quantum chromodynamics and harmonic sums

Indian Academy of Sciences (India)

In the large- limit of QCD, two-point functions of local operators become harmonic sums. I review some properties which follow from this fact and which are relevant for phenomenological applications. This has led us to consider a class of analytic number theory functions as toy models of large- QCD which also is ...

Tracing back resonances to families of Regge trajectories. New finite energy sum rules

International Nuclear Information System (INIS)

Mandelbrojt, Jacques.

1975-04-01

An amplitude is supposed to be expressed for large enough energies as a sum of contributions of Regge poles. Calling family of trajectories the set of trajectories which differ by integers from one of them, a correspondance, such that the energy and width of a given resonance depend on only family of trajectories, is established between resonances of the amplitude and families of trajectories. The contribution to the amplitude of each family of trajectories is shown to satisfy the same finite energy sum rules as does the amplitude itself. In these sum rules the resonance approximation can be made where the only resonances that will appear are those which are in correspondence with the family [fr

Old tensor mesons in QCD sum rules

International Nuclear Information System (INIS)

Aliev, T.M.; Shifman, M.A.

1981-01-01

Tensor mesons f, A 2 and A 3 are analyzed within the framework of QCD sum rules. The effects of gluon and quark condensate is accounted for phenomenologically. Accurate estimates of meson masses and coupling constants of the lowest-lying states are obtained. It is shown that the masses are reproduced within theoretical uncertainty of about 80 MeV. The coupling of f meson to the corresponding quark current is determined. The results are in good aqreement with experimental data [ru

The Gauge-Invariant Angular Momentum Sum-Rule for the Proton

CERN Document Server

Shore, G.M.

2000-01-01

We give a gauge-invariant treatment of the angular momentum sum-rule for the proton in terms of matrix elements of three gauge-invariant, local composite operators. These matrix elements are decomposed into three independent form factors, one of which is the flavour singlet axial charge. We further show that the axial charge cancels out of the sum-rule, so that it is unaffacted by the axial anomaly. The three form factors are then related to the four proton spin components in the parton model, namely quark and gluon intrinsic spin and orbital angular momentum. The renormalisation of the three operators is determined to one loop from which the scale dependence and mixing of the spin components is derived under the constraint that the quark spin be scale-independent. We also show how the three form factors can be measured in experiments.

The Thomas-Reiche-Kuhn sum rule and the toroid moments

International Nuclear Information System (INIS)

Dubovik, V.M.

1975-01-01

By example of the Thomas-Reiche-Kuhn sum rule a procedure is given for calculating the retardation effects in any E-transition strengths via the toroid moments. The investigation has been performed at the Laboratory of Theoretical Physics, JINR

A simple derivation of new sum rules of Bessel functions

International Nuclear Information System (INIS)

Ciocci, F.; Dattoli, G.; Dipace, A.

1985-01-01

In this note it is exploited a recently suggested technique to get simple expressions for a class of sum rules of Bessel functions appearing in plasma physics; their relevance to the numerical evaluation of the Turkin function is also discussed

Q2 evolution of generalized Baldin sum rule for the proton

International Nuclear Information System (INIS)

Liang, Y.; Christy, M. E.; Ent, R.; Keppel, C. E.

2006-01-01

The generalized Baldin sum rule for virtual photon scattering, the unpolarized analogy of the generalized Gerasimov-Drell-Hearn integral provides an important way to investigate the transition between perturbative QCD and hadronic descriptions of nucleon structure. This sum rule requires integration of the nucleon structure function F 1 , which until recently had not been measured at low Q 2 and large x, i.e., in the nucleon resonance region. This work uses new data from inclusive electron-proton scattering in the resonance region obtained at Jefferson Lab, in combination with SLAC deep inelastic scattering data, to present first precision measurements of the generalized Baldin integral for the proton in the Q 2 range of 0.3 to 4.0 GeV 2

On sum rules for charge transition density

International Nuclear Information System (INIS)

Gul'karov, I.S.

1979-01-01

The form factors of the quadrupole and octupole oscillations of the 12 C nucleus are compared with the predictions of the sum rules for the charge transition density (CTD). These rules allow to obtain various CTD which contain the components k: rsup(lambda+2k-2)rho(r) and rsup(lambda+2k-1)(drho(r)/dr) (k=0, 1, 2...) and can be applied to analyze the inelastic scattering of high energy particles by nuclei. It is shown that the CTD under consideration have different radius dependence and describe the data essentially better (though ambiguously) than the Tassy and Steinwedel-Jensen models do. The recurrent formulas are derived for the ratios of the higher order transition matrix elements and CTD. These formulas can be used to predict the CTD behaviour for highly excited nuclear states

Borel sum rules for octet baryons in nuclear medium

International Nuclear Information System (INIS)

Kondo, Y.; Morimatsu, O.

1992-06-01

Borel sum rules are examined for octet baryons in the nuclear medium. First, it is noticed that in the medium the dispersion relation is realized for the retarded correlation Π R (ω, q 2 ) in the energy ω. Then, Π R (ω, q 2 ) is split into even and odd parts of ω in order to apply the Borel transformation. The obtained Borel sum rules differ from those of previous works. The mass shifts of octet baryons are calculated in the leading order of the operator product expansion with linear density approximation for the condensates. It is found that both scalar and vector condensates of the quark field, and + q>, induce attraction to the octet baryons in the medium in contrast to the results of previous works. It is also found that |δM N | > |δM Λ | > |δM Σ | ∼ |δM Ξ |. The absolute values, however, turn out to be one order of magnitude larger than those empirically known if a Borel mass of around 1 GeV is used in the present approximation. (author)

Sum rules for elements of flavor-mixing matrices based on a non-semisimple symmetry

International Nuclear Information System (INIS)

Sogami, Ikuo S.

2006-01-01

Sum rules for elements of flavor-mixing matrices (FMMs) are derived within a new algebraic theory for flavor physics, in which the FMMs are identified with elements of the Lie group isomorphic to SU(2) x U(1). The resulting sum rules originating from the unique elaborate structure of the algebra of the group are so simple and explicit that their validity can be confirmed by analyzing properly processed experimental data. (author)

A new sum rule relating the deep-inelastic polarized structure function to the cross section of photoproduction

International Nuclear Information System (INIS)

Koretune, Susumu

1993-01-01

A sum rule which relates the deep-inelastic polarized structure function g 1 p (x,Q 2 ) to the cross section of photoproduction, (σ 3/2 -σ 1/2 ), is derived. This rule makes it possible to compare the integral of g 1 p (x,Q 2 ) with the Drell-Hearn-Gerasimov sum rule without worrying about contributions from higher twist terms. Further this sum rule shows that there may exist a dynamical mechanism which relates the low energy region to the high energy one. It is conjectured that the spontaneous chiral symmetry breaking of the vacuum is the origin of this mechanism. (author)

Charge symmetry breaking in spin dependent parton distributions and the Bjorken sum rule

International Nuclear Information System (INIS)

Cloet, I.C.; Horsley, R.; Londergan, J.T.

2012-04-01

We present the rst determination of charge symmetry violation (CSV) in the spin-dependent parton distribution functions of the nucleon. This is done by determining the rst two Mellin moments of the spin-dependent parton distribution functions of the octet baryons from N f =2+1 lattice simulations. The results are compared with predictions from quark models of nucleon structure. We discuss the contribution of partonic spin CSV to the Bjorken sum rule, which is important because the CSV contributions represent the only partonic corrections to the Bjorken sum rule.

Charge symmetry breaking in spin dependent parton distributions and the Bjorken sum rule

Energy Technology Data Exchange (ETDEWEB)

Cloet, I.C. [Adelaide Univ, SA (Australia). CSSM, School of Chemistry and Physics; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Londergan, J.T. [Indiana Univ., Bloomington, IN (US). Dept. of Physics and Center for Exploration of Energy and Matter] (and others)

2012-04-15

We present the rst determination of charge symmetry violation (CSV) in the spin-dependent parton distribution functions of the nucleon. This is done by determining the rst two Mellin moments of the spin-dependent parton distribution functions of the octet baryons from N{sub f}=2+1 lattice simulations. The results are compared with predictions from quark models of nucleon structure. We discuss the contribution of partonic spin CSV to the Bjorken sum rule, which is important because the CSV contributions represent the only partonic corrections to the Bjorken sum rule.

QCD Sum Rule External Field Approach and Vacuum Susceptibilities

Institute of Scientific and Technical Information of China (English)

ZONG Hong-Shi; PING Jia-Lun; CHANG Chao-His; WANG Fan; ZHAO En-Guang

2002-01-01

Based on QCD sum rule three-point and two-point external field formulas respectively, the vector vacuumsusceptibilities are calculated at the mean-field level in the framework of the global color symmetry model. It is shownthat the above two approaches of determination of the vector vacuum susceptibility may lead to different results. Thereason of this contradiction is discussed.

Isospin sum rule for nuclear photoabsorption: Effect of retardation

International Nuclear Information System (INIS)

Maize, M.A.; Fallieros, S.

1987-01-01

Motivated by the close similarity between a sum rule originally derived by Cabibbo and Radicati and a simplified version based on nonrelativistic nuclear physics in the long-wavelength limit, we have investigated the effect of retardation corrections. An account of the contributions due to higher multipolarities is presented, together with a physical interpretation of the results

More sum rules for quark and lepton masses

International Nuclear Information System (INIS)

Terazawa, Hidezumi.

1990-04-01

Sum rules for quark and lepton masses are derived from the Ward identity of Chanowitz and Ellis for the vertex function of the trace of the energy-momentum tensor and the two axial-vector currents and the partially conserved axial-vector current hypothesis. They indicate, among other things, that the constituent quark masses of u and d and those of the techniquarks, if any, are about 300 MeV and 300 GeV, respectively. (author)

Infrared renormalons and the relations between the Gross-Llewellyn Smith and the Bjorken polarized and unpolarized sum rules

International Nuclear Information System (INIS)

Kataev, A.L.

2005-01-01

It is demonstrated that the infrared renormalon calculus indicates that the QCD theoretical expressions for the Gross-Llewellyn Smith sum rule and for the Bjorken polarized and unpolarized ones contain an identical negative twist-4 1/Q 2 correction. This observation is supported by the consideration of the results of calculations of the corresponding twist-4 matrix elements. Together with the indication of the similarity of perturbative QCD contributions to these three sum rules, this observation leads to simple new theoretical relations between the Gross-Llewellyn Smith and Bjorken polarized and unpolarized sum rules in the energy region Q 2 ≥ 1 GeV 2 . The validity of this relation is checked using concrete experimental data for the Gross-Llewellyn Smith and Bjorken polarized sum rules [ru

Predictions for the Dirac C P -violating phase from sum rules

Science.gov (United States)

Delgadillo, Luis A.; Everett, Lisa L.; Ramos, Raymundo; Stuart, Alexander J.

2018-05-01

We explore the implications of recent results relating the Dirac C P -violating phase to predicted and measured leptonic mixing angles within a standard set of theoretical scenarios in which charged lepton corrections are responsible for generating a nonzero value of the reactor mixing angle. We employ a full set of leptonic sum rules as required by the unitarity of the lepton mixing matrix, which can be reduced to predictions for the observable mixing angles and the Dirac C P -violating phase in terms of model parameters. These sum rules are investigated within a given set of theoretical scenarios for the neutrino sector diagonalization matrix for several known classes of charged lepton corrections. The results provide explicit maps of the allowed model parameter space within each given scenario and assumed form of charged lepton perturbations.

Quark-number susceptibility, thermodynamic sum rule, and the hard thermal loop approximation

International Nuclear Information System (INIS)

Chakraborty, Purnendu; Mustafa, Munshi G.; Thoma, Markus H.

2003-01-01

The quark number susceptibility, associated with the conserved quark number density, is closely related to the baryon and charge fluctuations in the quark-gluon plasma, which might serve as signature for the quark-gluon plasma formation in ultrarelativistic heavy-ion collisions. In addition to QCD lattice simulations, the quark number susceptibility has been calculated recently using a resummed perturbation theory (hard thermal loop resummation). In the present work we show, based on general arguments, that the computation of this quantity neglecting hard thermal loop vertices contradicts the Ward identity and violates the thermodynamic sum rule following from quark number conservation. We further show that the hard thermal loop perturbation theory is consistent with the thermodynamic sum rule

Experimental check of the Gerasimov-Drell-Hearn sum rule for H1

International Nuclear Information System (INIS)

Dutz, H.; Drachenfels, W. von; Frommberger, F.; Hillert, W.; Klein, F.; Menze, D.; Rohlof, C.; Schoch, B.; Helbing, K.; Speckner, T.; Zeitler, G.; Anton, G.; Bock, A.; Godo, M.; Kiel, B.; Michel, T.; Naumann, J.; Krimmer, J.; Grabmayr, P.; Sauer, M.

2004-01-01

For the first time we checked the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for the proton experimentally in the photon energy range from 0.2-2.9 GeV with the tagged photon facilities at MAMI (Mainz) and ELSA (Bonn). New data of the doubly polarized total cross section difference are presented in the energy range from 1.6 to 2.9 GeV. The contribution to the GDH integral from 0.2-2.9 GeV yields [254±5(stat)±12(syst)] μb with negative contributions in the Regge regime at photon energies above 2.1 GeV. This trend supports the validity of the GDH sum rule

Beauty vector meson decay constants from QCD sum rules

Energy Technology Data Exchange (ETDEWEB)

Lucha, Wolfgang [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna (Austria); Melikhov, Dmitri [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna (Austria); D. V. Skobeltsyn Institute of Nuclear Physics, M. V. Lomonosov Moscow State University, 119991, Moscow (Russian Federation); Simula, Silvano [Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tre, Via della Vasca Navale 84, I-00146, Roma (Italy)

2016-01-22

We present the outcomes of a very recent investigation of the decay constants of nonstrange and strange heavy-light beauty vector mesons, with special emphasis on the ratio of any such decay constant to the decay constant of the corresponding pseudoscalar meson, by means of Borel-transformed QCD sum rules. Our results suggest that both these ratios are below unity.

QCD effects to Bjorken unpolarized sum rule for νN deep-inelastic scattering

International Nuclear Information System (INIS)

Alekhin, S I; Kataev, A L

2003-01-01

The possibility of the first measurement of Bjorken unpolarized sum rule for F 1 structure function of νN deep-inelastic scattering at neutrino factories is commented. The brief summary of various theoretical contributions to this sum rule is given. Using the next-to-leading set of parton distributions functions, we simulate the expected Q 2 -behaviour and emphasize that its measurement can allow us to determine the value of the QCD strong coupling constant α s with reasonable theoretical uncertainty, dominated by the ambiguity in the existing estimates of the twist-4 non-perturbative 1/Q 2 -effect

Electromagnetic form factors of the ρ meson in light cone QCD sum rules

International Nuclear Information System (INIS)

Aliev, T.M.; Savci, M.

2004-01-01

We investigate the electromagnetic form factors of the ρ meson in light cone QCD sum rules. We find that the ratio of the magnetic and charge form factors is larger than 2 at all values of Q 2 (Q 2 ≥0.5 GeV 2 ). The values of the individual form factors at fixed values of Q 2 predicted by the light cone QCD sum rules are quite different compared to the results of other approaches. These results can be checked in the future, when more precise data on ρ meson form factors is available

The polarised photon g1γ sum rule at the linear collider and high luminosity B factories

International Nuclear Information System (INIS)

Shore, G.M.

2005-01-01

The sum rule for the first moment of the polarised (virtual) photon structure function g 1 γ (x,Q 2 ;K 2 ) is revisited in the light of proposals for future e + e - colliders. The sum rule exhibits an array of phenomena characteristic of QCD: for real photons (K 2 =0) electromagnetic gauge invariance constrains the first moment to vanish; the limit for asymptotic photon virtuality (m ρ 2 -bar K 2 -bar Q 2 ) is governed by the electromagnetic U A (1) axial anomaly and the approach to asymptopia by the gluonic anomaly; for intermediate values of K 2 , it reflects the realisation of chiral symmetry and is determined by the off-shell radiative couplings of the pseudoscalar mesons; finally, like many polarisation phenomena in QCD, the first moment of g 1 γ involves the gluon topological susceptibility. In this paper, we review the original sum rule proposed by Narison, Shore and Veneziano and extend the relation with pseudoscalar mesons. The possibility of measuring the sum rule in future polarised e + e - colliders is then considered in detail, focusing on the International Linear Collider (ILC) and high luminosity B factories. We conclude that all the above features of the sum rule should be accessible at a polarised collider with the characteristics of SuperKEKB

Nuclear Symmetry Energy with QCD Sum Rule

International Nuclear Information System (INIS)

Jeong, K.S.; Lee, S.H.

2013-01-01

We calculate the nucleon self-energies in an isospin asymmetric nuclear matter using QCD sum rule. Taking the difference of these for the neutron and proton enables us to express an important part of the nuclear symmetry energy in terms of local operators. Calculating the operator product expansion up to mass dimension six operators, we find that the main contribution to the difference comes from the iso-vector scalar and vector operators, which is reminiscent to the case of relativistic mean field type theories where mesons with aforementioned quantum numbers produce the difference and provide the dominant mechanism for nuclear symmetry energy. (author)

QCD sum rules in medium and the Okamoto-Nolen-Schiffer anomaly

International Nuclear Information System (INIS)

Hatsuda, T.; Hogaasen, H.; Prakash, M.

1991-01-01

The QCD sum-rule approach for a nuclear medium is developed. The medium dependence of the neutron-proton mass difference calculated from this approach gives effects in nuclei which have direct relevance for the resolution of the Okamoto-Nolen-Schiffer anomaly

Calculation of excited vector meson electron widths using QCD sum rules

International Nuclear Information System (INIS)

Geshkenbein, B.V.

1984-01-01

The sum rules are suggested which allow one to calculate the electron widths of excited vector mesons of the PSI, UPSILON, rho meson family assuming the values of their masses to be known. The calculated values of the electron widths agree with experiment

Sum rules, asymptotic behaviour and (multi)baryon states in the Skyrme model

International Nuclear Information System (INIS)

Mignaco, J.A.; Wulck, S.

1990-01-01

We obtain sum roles that should be satisfied by the solutions of the Euler-Lagrange equation for the chiral angle in the Skyrme model in the hedgehog representation. The sum rules allow to determine the existence of solutions with integer baryon number for well determined values of a relevant dimensionless parameter Φ only. For all other values, there are no solutions with integer baryon number, in particular for the pure non-linear sigma model. (author)

Spectral sum rules and search for periodicities in DNA sequences

International Nuclear Information System (INIS)

Chechetkin, V.R.

2011-01-01

Periodic patterns play the important regulatory and structural roles in genomic DNA sequences. Commonly, the underlying periodicities should be understood in a broad statistical sense, since the corresponding periodic patterns have been strongly distorted by the random point mutations and insertions/deletions during molecular evolution. The latent periodicities in DNA sequences can be efficiently displayed by Fourier transform. The criteria of significance for observed periodicities are obtained via the comparison versus the counterpart characteristics of the reference random sequences. We show that the restrictions imposed on the significance criteria by the rigorous spectral sum rules can be rationally described with De Finetti distribution. This distribution provides the convenient intermediate asymptotic form between Rayleigh distribution and exact combinatoric theory. - Highlights: → We study the significance criteria for latent periodicities in DNA sequences. → The constraints imposed by sum rules can be described with De Finetti distribution. → It is intermediate between Rayleigh distribution and exact combinatoric theory. → Theory is applicable to the study of correlations between different periodicities. → The approach can be generalized to the arbitrary discrete Fourier transform.

B→ππ form factors from light-cone sum rules with B-meson distribution amplitudes

Energy Technology Data Exchange (ETDEWEB)

Cheng, Shan; Khodjamirian, Alexander [Theoretische Physik 1, Naturwissenschaftlich-Technische Fakultät,Department Physik, Universität Siegen,Walter-Flex-Strasse 3, 57068 Siegen (Germany); Virto, Javier [Albert Einstein Center for Fundamental Physics,Institute for Theoretical Physics, University of Bern,Sidlerstrasse 5, CH-3012 Bern (Switzerland)

2017-05-30

We study B→ππ form factors using QCD light-cone sum rules with B-meson distribution amplitudes. These form factors describe the semileptonic decay B→ππℓν̄{sub ℓ}, and constitute an essential input in B→ππℓ{sup +}ℓ{sup −} and B→πππ decays. We employ the correlation functions where a dipion isospin-one state is interpolated by the vector light-quark current. We obtain sum rules where convolutions of the P-wave B̄{sup 0}→π{sup +}π{sup 0} form factors with the timelike pion vector form factor are related to universal B-meson distribution amplitudes. These sum rules are valid in the kinematic regime where the dipion state has a large energy and a low invariant mass, and reproduce analytically the known light-cone sum rules for B→ρ form factors in the limit of ρ-dominance and zero width, thus providing a systematics for so far unaccounted corrections to B→ρ transitions. Using data for the pion vector form factor, we estimate finite-width effects and the contribution of excited ρ-resonances to the B→ππ form factors. We find that these contributions amount up to ∼20% in the small dipion mass region where they can be effectively regarded as a nonresonant (P-wave) background to the B→ρ transition.

Finite energy sum rules and instantons in the instanton liquid model

International Nuclear Information System (INIS)

Elias, V.; Fang Shi; Steele, T.G.

1998-01-01

We obtain the imaginary part of the direct single-instanton contribution to the pseudoscalar correlator, as defined by the appropriate dispersion relation, in order to derive an explicit integral representation for the instanton contribution to finite energy sum rules in the instanton liquid model. (author)

Neutron matter within QCD sum rules

Science.gov (United States)

Cai, Bao-Jun; Chen, Lie-Wen

2018-05-01

The equation of state (EOS) of pure neutron matter (PNM) is studied in QCD sum rules (QCDSRs ). It is found that the QCDSR results on the EOS of PNM are in good agreement with predictions by current advanced microscopic many-body theories. Moreover, the higher-order density terms in quark condensates are shown to be important to describe the empirical EOS of PNM in the density region around and above nuclear saturation density although they play a minor role at subsaturation densities. The chiral condensates in PNM are also studied, and our results indicate that the higher-order density terms in quark condensates, which are introduced to reasonably describe the empirical EOS of PNM at suprasaturation densities, tend to hinder the appearance of chiral symmetry restoration in PNM at high densities.

Spin Sum Rules and Polarizabilities: Results from Jefferson Lab

International Nuclear Information System (INIS)

Jian-Ping Chen

2006-01-01

The nucleon spin structure has been an active, exciting and intriguing subject of interest for the last three decades. Recent experimental data on nucleon spin structure at low to intermediate momentum transfers provide new information in the confinement regime and the transition region from the confinement regime to the asymptotic freedom regime. New insight is gained by exploring moments of spin structure functions and their corresponding sum rules (i.e. the generalized Gerasimov-Drell-Hearn, Burkhardt-Cottingham and Bjorken). The Burkhardt-Cottingham sum rule is verified to good accuracy. The spin structure moments data are compared with Chiral Perturbation Theory calculations at low momentum transfers. It is found that chiral perturbation calculations agree reasonably well with the first moment of the spin structure function g 1 at momentum transfer of 0.05 to 0.1 GeV 2 but fail to reproduce the neutron data in the case of the generalized polarizability (delta) LT (the (delta) LT puzzle). New data have been taken on the neutron ( 3 He), the proton and the deuteron at very low Q 2 down to 0.02 GeV 2 . They will provide benchmark tests of Chiral dynamics in the kinematic region where the Chiral Perturbation theory is expected to work

Modified Adler sum rule and violation of charge symmetry

International Nuclear Information System (INIS)

Dominguez, C.A.; Moreno, H.; Zepeda, A.

The consequences of a once subtracted dispersion relation in the derivation of the Adler sum rule are investigated. It is shown that one can expect a breakdown of charge symmetry, of the isotriplet current hypothesis, and of scaling of the structure functions. These breakdowns are related to the possible presence of a non-zero subtraction function at asymptotic energies and arbitrary q 2 . Second class currents and PCAC relations are also discussed

gsub(ωrhoπ) coupling constant from QCD sum rules

International Nuclear Information System (INIS)

Eletsky, V.L.; Ioffe, B.L.; Kogan, Ya.I.

1982-01-01

QCD sum rules for the vertex function of two vector and one axial vector currents are used to calculate the gsub(ωrhoπ) coupling constant (where gsub(ωrhoπ) is a transition coupling constant for ω → rhoπ process). The obtained value, gsub(ωrhoπ) approximately 17 GeV -1 is in a good agreement with experimental data

Calculation of electromagnetic rhoπ formfactor from QCD sum rules

International Nuclear Information System (INIS)

Eletskij, V.L.; Kogan, Ya.I.

1982-01-01

Electromagnetic rhoπγ form factor at intermediate momentum transfer, 0.7 GeV 2 2 2 , is calculated using QCD sum rules for the vertex function of two vector and one axial-vector currents. In this region the results obtained are consistent within 25% accuracy with the vector meson dominance model predictions and can be regarded as its theoretical ustification

SUM-RULES FOR MAGNETIC DICHROISM IN RARE-EARTH 4F-PHOTOEMISSION

NARCIS (Netherlands)

THOLE, BT; VANDERLAAN, G

1993-01-01

We present new sum rules for magnetic dichroism in spin polarized photoemission from partly filled shells which give the expectation values of the orbital and spin magnetic moments and their correlations in the ground state. We apply this to the 4f photoemission of rare earths, where the

I. Photon transition amplitudes predicted by the transformation between current and constituent quarks. II. Saturation of the Drell--Hearn--Gerasimov sum rule

International Nuclear Information System (INIS)

Karliner, I.

1975-01-01

The SU(6)-W group structure appears in both current algebra and in the spectroscopy of hadrons. Recently, a considerable progress has taken place in relating these two SU(6)-W structures. The consequences of the proposed correspondence, as it applies to real photon transitions, are investigated in this work. The general structure of such transitions is shown, and a set of resulting selection rules is presented for the multipole character of the photon amplitudes. Many specific amplitudes for both mesons and baryons are worked out and their signs and magnitudes are compared with available experimental data. The saturation of the Drell-Hearn-Gerasimov sum rule for the forward spin-flip amplitude of nucleon Compton scattering was investigated. The sum rule saturation was studied using recent analyses of single pion photoproduction in the region up to photon laboratory energies of 1.2 GeV. The original sum rule is decomposed into separate sum rules originating from different isospin compnents of the electromagnetic current. All three sum rules receive important nonresonant as well as resonant contributions. The isovector-isovector sum rule, whose contributions are known best, is found to be nearly saturated, lending support to the assumptions underlying the sum rules. The failure of the isovector-isoscalar sumrule to be saturated is then presumably to be blamed on inadequate data for inelastic contributions. (Diss. Abs,r. Int., B)

Radiative transitions in quarkonjum and quantum chromodynamics

International Nuclear Information System (INIS)

Khodjamirian, A.Yu.

1980-01-01

A new approach to the radiative transitions in quarkonium (c, anti c, b anti b, ...) based on the asymptotic freedom of QCD and on the analyticity is proposed. This approach consists in derivation of dispersion sum rules relating the transition amplitudes with triangle quark diagrams. In this way, a possibility emerges to estimate these amplitudes in a model-independent way. The sum rules are obtained in zeroth order of QCD for transitions between C-even levels 0 ++ , 1 ++ , 2 ++ , 0 -+ and vector (1 -- ) levels. The influence of gluon corrections is discussed and the optimum moments of sum rules are chosen for which these corrections are expected to be at the level of O(αsub(s)) approximately 20%. The widths of radiative transitions in charmonium calculated by means of sum rules turn out to be in agreement with available experimental data. The estimates for analogous transitions in b-quarkonium are also presented. The suggested approach is compared with nonrelativistic models of radiative transitions [ru

Finite temperature QCD sum rule and the ρ-meson

International Nuclear Information System (INIS)

Liu Jueping; Jin Yaping

1995-01-01

The contributions from the three-gluon condensates to the finite temperature QCD sum rule for the ρ-meson are calculated, and then the dependence of the properties of the ρ-meson upon temperature is investigated in a string model of condensates. The results show that the parameters characterizing the properties of the ρ-meson change noticeably when the temperature closes to the critical temperature of the condensates, and if the critical temperatures of condensates are the same

QCD determination of the A1-p-π system through vertex light-cone sum rules

International Nuclear Information System (INIS)

Craigie, N.S.; Paver, N.; Riazzudin

1986-01-01

We analyze the rho-A 1 -π system within the context of vertex light-cone sum rules, which are believed to be rigorously satisfied in QCD. It is pointed out that these sum rules provide very strong constraints on the hardronic spectrum and with additional assumptions lead to new predictions, which go significantly beyond those obtained from current algebra in the past. In particular, we report some new results about the rho-A 1 -π couplings and the various transitions form factors in tau-semi-leptonic decays. (orig.)

Searching for hidden-charm baryonium signals in QCD sum rules

Energy Technology Data Exchange (ETDEWEB)

Chen, Hua-Xing; Zhou, Dan [Beihang University, School of Physics, Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beijing (China); Chen, Wei [University of Saskatchewan, Department of Physics and Engineering Physics, Saskatoon, SK (Canada); Liu, Xiang [Lanzhou University, School of Physical Science and Technology, Lanzhou (China); Lanzhou University, Research Center for Hadron and CSR Physics, Institute of Modern Physics of CAS, Lanzhou (China); Zhu, Shi-Lin [Peking University, School of Physics, State Key Laboratory of Nuclear Physics and Technology, Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Peking University, Center of High Energy Physics, Beijing (China)

2016-11-15

We give an explicit QCD sum rule investigation for hidden-charm baryonium states with the quark content u anti ud anti dc anti c, spin J = 0/1/2/3, and of both positive and negative parities. We systematically construct the relevant local hidden-charm baryonium interpolating currents, which can actually couple to various structures, including hidden-charm baryonium states, charmonium states plus two pions, and hidden-charm tetraquark states plus one pion, etc. We do not know which structure these currents couple to at the beginning, but after sum rule analyses we can obtain some information. We find some of them can couple to hidden-charm baryonium states, using which we evaluate the masses of the lowest-lying hidden-charm baryonium states with quantum numbers J{sup P} = 2{sup -}/3{sup -}/0{sup +}/1{sup +}/2{sup +} to be around 5.0 GeV. We suggest to search for hidden-charm baryonium states, especially the one of J = 3{sup -}, in the D-wave J/ψππ and P-wave J/ψρ and J/ψω channels in this energy region. (orig.)

Estimating the small-x exponent of the structure function g1NS from the Bjorken sum rule

International Nuclear Information System (INIS)

Knauf, Anke; Meyer-Hermann, Michael; Soff, Gerhard

2002-01-01

We present a new estimate of the exponent governing the small-x behavior of the nonsinglet structure function g 1 p-n derived under the assumption that the Bjorken sum rule is valid. We use the world wide average of α s and the NNNLO QCD corrections to the Bjorken sum rule. The structure function g 1 NS is found to be clearly divergent for small x

QCD Sum-Rule Calculation of the Kinetic Energy and Chromo-Interaction of Heavy Quarks Inside Mesons

CERN Document Server

Neubert, M

1996-01-01

We present a QCD sum-rule determination of the heavy-quark kinetic energy inside a heavy meson, $-\\lambda_1/2 m_Q$, which is consistent with the field-theory analog of the virial theorem. We obtain $-\\lambda_1\\approx (0.10\\pm 0.05)~\\mbox{GeV}^2$, significantly smaller than a previous sum-rule result, but in good agreement with recent determinations from the analysis of inclusive decays. We also present a new determination of the chromo-magnetic interaction, yielding $\\lambda_2(m_b)=(0.15\\pm 0.03)~\\mbox{GeV}^2$. This implies $m_{B^*}^2-m_B^2=(0.60\\pm 0.12)~\\mbox{GeV}^2$, in good agreement with experiment. As a by-product of our analysis, we derive the QCD sum rules for the three form factors describing the meson matrix element of a velocity-changing current operator containing the gluon field-strength tensor.

Meson spectroscopy, quark mixing and quantum chromodynamics

International Nuclear Information System (INIS)

Filippov, A.T.

1979-01-01

A semiphenomenological theory of mass spectrum for mesons, consisting of a quark-antiquark pair, is presented. Relativistic kinematical effects of the quark mass differences, the SU(3)-symmetry breaking in slopes of the Regge trajectories and in radially excited states are taken into account. The OZI-rule breaking is taken into account by means of the mixing matrix for the quark wave functions, whose form is suggested by the quantum chromodynamics. A simple extrapolation of expression, given by the quantum chromodynamics from the ''asymptotic freedom'' region to the ''infrared slavery'' region is proposed to describe the dependence of the mixing parameters on the meson masses. To calculate masses and mixing angles for pseudoscalar mesons a condition is proposed that the pion mass is minimal. In this situation the eta-meson mass is near the maximal value. The predictions of the theory for masses and mixing angles of the mesons are in good agreement with the experiment

The calculation of the quark distribution amplitudes of decuplet baryons by means of QCD sum rules

International Nuclear Information System (INIS)

Bonekamp, J.

1994-11-01

Using the QCD sum rule technique, we derive the quark distribution amplitudes of the decuplet memebers Δ(1232), Σ * (1385), Ξ * (1530) and Ω(1672). Generalizing the treatment of the Bethe-Salpeter amplitude, we can distinguish spin- and orbital- angular momentum parts of the quark distributions and establish separate sum rules for the contributions. Projecting out the angular momentum 1/2 contributions, we obtain sum rules which are saturated by the lowest resonance in the given iso spin channel, thus resolving deficiencies of the standard approach. We find that for helicity 1/2 the spin part of the quark distributions is asymmetric. Also the orbital angular momentum contributions are extremely asymmetric and tend to decrease the asymmetry of the spin part. As a result of SU(3) symmetry breaking, configuration mixing occurs and the decuplet baryons Σ * and Ξ * receive octet contributions. The antisymmetric part of these octet contributions is calculated. (orig.)

Analysis of the doubly heavy baryons in the nuclear matter with the QCD sum rules

International Nuclear Information System (INIS)

Wang, Zhi-Gang

2012-01-01

In this article, we study the doubly heavy baryon states Ξ cc , Ω cc , Ξ bb and Ω bb in the nuclear matter using the QCD sum rules, and derive three coupled QCD sum rules for the masses, vector self-energies and pole residues. The predictions for the mass-shifts in the nuclear matter ΔM Ξ cc =-1.11simGeV, ΔM Ω cc =-0.33∝GeV, ΔM Ξ bb =-3.37∝GeV and ΔM Ω bb =-1.05∝GeV can be confronted with experimental data in the future. (orig.)

QCD light-cone sum rule estimate of charming penguin contributions in B→ππ

International Nuclear Information System (INIS)

Khodjamirian, A.; Mannel, Th.; Melic, B.

2003-01-01

Employing the QCD light-cone sum rule approach we calculate the B→ππ hadronic matrix element of the current-current operator with c quarks in the penguin topology (''charming penguin''). The dominant contribution to the sum rule is due to the c-quark loop at short distances and is of O(α s ) with respect to the factorizable B→ππ amplitude. The effects of soft gluons are suppressed at least by O(α s m b -2 ). Our result indicates that sizable nonperturbative effects generated by charming penguins at finite m b are absent. The same is valid for the penguin contractions of the current-current operators with light quarks

QCD light-cone sum rule estimate of charming penguin contributions in B→ππ

International Nuclear Information System (INIS)

Khodjamirian, A.; Mannel, Th.; Melic, B.

2003-01-01

Employing the QCD light-cone sum rule approach we calculate the B→ππ hadronic matrix element of the current-current operator with c quarks in the penguin topology ('charming penguin'). The dominant contribution to the sum rule is due to the c-quark loop at short distances and is of O(α s ) with respect to the factorizable B→ππ amplitude. The effects of soft gluons are suppressed at least by O(α s m b -2 ). Our result indicates that sizable nonperturbative effects generated by charming penguins at finite m b are absent. The same is valid for the penguin contractions of the current-current operators with light quarks

The nucleon axial isoscalar coupling constant and the Bjorken sum rule

International Nuclear Information System (INIS)

Belyaev, V.M.; Ioffe, B.L.; Kogan, Ya.I.

1984-01-01

The nucleon coupling constant with the axial isoscalar current entering the Bjorken sum rule for the deep inelastic scattering of polarized electrons on a polarized target is calculated in nonperturbative QCD. The result, gsub(A)sup(s) approximately 0.5, is about a factor of two smaller as compared to that of the SU(6) symmetric quark model

The influence of gluonic operators on QCD sum rules for baryons

International Nuclear Information System (INIS)

Schall, D.

1982-01-01

In this thesis the operator product expansion (OPE) is extended up to operators of dimension d=10. The coefficient functions are calculated only up to order αsub(s). Thereby the performation of the OPE by means of the Schwinger operator formalism is extensively described. In the final section the sum rules for nucleon and delta are discussed. (orig./HSI) [de

Sum rules and other properties involving resonance projection operators. [for optical potential description of electron scattering from atoms and ions

Science.gov (United States)

Berk, A.; Temkin, A.

1985-01-01

A sum rule is derived for the auxiliary eigenvalues of an equation whose eigenspectrum pertains to projection operators which describe electron scattering from multielectron atoms and ions. The sum rule's right-hand side depends on an integral involving the target system eigenfunctions. The sum rule is checked for several approximations of the two-electron target. It is shown that target functions which have a unit eigenvalue in their auxiliary eigenspectrum do not give rise to well-defined projection operators except through a limiting process. For Hylleraas target approximations, the auxiliary equations are shown to contain an infinite spectrum. However, using a Rayleigh-Ritz variational principle, it is shown that a comparatively simple aproximation can exhaust the sum rule to better than five significant figures. The auxiliary Hylleraas equation is greatly simplified by conversion to a square root equation containing the same eigenfunction spectrum and from which the required eigenvalues are trivially recovered by squaring.

Magnetic moment for the negative parity Λ→Σ0 transition in light cone QCD sum rules

Directory of Open Access Journals (Sweden)

T.M. Aliev

2016-07-01

Full Text Available The magnetic moment of the Λ→Σ0 transition between negative parity baryons is calculated in framework of the QCD sum rules approach by using the general form of the interpolating currents. The pollution arising from the positive-to-positive, and positive-to-negative parity baryons is eliminated by constructing the sum rules for different Lorentz structures. A comparison of our result with the predictions of the results of other approaches for the positive parity baryons is presented.

Energy and Regge residues in quantum-mechanical ''QCD'' sum rules

International Nuclear Information System (INIS)

Durand, B.; Durand, L.

1986-01-01

It was shown recently by Fishbane, Kaus, and Gasiorowicz that the residues at the poles of quantum-mechanical two-point functions for arbitrary angular momenta l have an incorrect l dependence when calculated by the sum-rule method used for the analogous problem in QCD. Knowledge of the residues is of interest since they are directly related to particle couplings and decay widths. We develop reliable expressions for the energy and Regge residues using semiclassical methods

Renormalized sum rules for structure functions of heavy meson decays

International Nuclear Information System (INIS)

Grozin, A.G.; Korchemsky, G.P.

1996-01-01

We consider the properties of the structure functions of inclusive heavy meson decays B→X c and treat the c quark mass as a free parameter. We show that in two extreme cases of heavy and light c quarks the structure functions of heavy-heavy and heavy-light transitions are given by a Fourier transform of the matrix elements of Wilson lines containing a timelike and a lightlike segment, correspondingly. Using the renormalization properties of Wilson lines we find the dependence of the structure functions on the factorization scale, the structure function of the heavy-heavy transition is renormalized multiplicatively, while that of the heavy-light transition obeys the GLAP-type evolution equation. We propose a generalization of the sum rules for the moments of the structure functions (Bjorken, Voloshin, and the open-quote open-quote third close-quote close-quote sum rules) with a soft exponential factorization cutoff, which correctly incorporates both perturbative and nonperturbative effects. We analyze nonperturbative corrections by first considering infrared renormalon contributions to the Wilson lines. Uncertainties induced by the leading renormalon pole at u=1/2 are exactly canceled by a similar uncertainty in the heavy quark pole mass. The leading nonperturbative corrections associated with the next renormalon at u=1 are parametrized by the matrix element μ π 2 which is proportional to the heavy quark kinetic energy. copyright 1996 The American Physical Society

Sum rule approach to the study of statistical decay properties of nuclear giant resonances

International Nuclear Information System (INIS)

Adhikari, S.K.; Hussein, M.S.

1987-03-01

Corrections to the well-known statistical sum rule that relates the summed transmission coefficients on the one hand and 2πΓ C.N. .ρ C.N. On the other, in the context of the statistical decay properties of nuclear giant resonances, are discussed. These corrections arise both from pre-equilibrium processes as well as from the giant resonance itself. It is shown that the compound nucleus average width is reduced as a result of these corrections. (Author) [pt

Perturbative corrections to Λ_b→Λ form factors from QCD light-cone sum rules

International Nuclear Information System (INIS)

Wang, Yu-Ming; Shen, Yue-Long

2016-01-01

We compute radiative corrections to Λ_b→Λ from factors, at next-to-leading logarithmic accuracy, from QCD light-cone sum rules with Λ_b-baryon distribution amplitudes. Employing the diagrammatic approach factorization of the vacuum-to-Λ_b-baryon correlation function is justified at leading power in Λ/m_b, with the aid of the method of regions. Hard functions entering the factorization formulae are identical to the corresponding matching coefficients of heavy-to-light currents from QCD onto soft-collinear effective theory. The universal jet function from integrating out the hard-collinear fluctuations exhibits richer structures compared with the one involved in the factorization expressions of the vacuum-to-B-meson correlation function. Based upon the QCD resummation improved sum rules we observe that the perturbative corrections at O(α_s) shift the Λ_b→Λ from factors at large recoil significantly and the dominant contribution originates from the next-to-leading order jet function instead of the hard coefficient functions. Having at hand the sum rule predictions for the Λ_b→Λ from factors we further investigate several decay observables in the electro-weak penguin Λ_b→Λ ℓ"+ℓ"− transitions in the factorization limit (i.e., ignoring the “non-factorizable' hadronic effects which cannot be expressed in terms of the Λ_b→Λ from factors), including the invariant mass distribution of the lepton pair, the forward-backward asymmetry in the dilepton system and the longitudinal polarization fraction of the leptonic sector.

What do QCD sum rules tell us about dense matter?

International Nuclear Information System (INIS)

Cohen, T.D.; Washington Univ., Seattle, WA

1995-01-01

The QCD sum rule approach to the properties of hadrons in both the vacuum and in nuclear matter is discussed. The primary limitation for the nuclear matter case is the absence of reliable phenomenological information about the form of the spectral function and about the value of certain four quark condensates. The approach gives moderate evidence in support of the Dirac phenomenology picture of strong attractive Lorentz scalar and repulsive Lorentz vector optical potentials. The approach gives weak evidence for decreasing vector meson masses in medium. (orig.)

Isovector giant monopole resonances: A sum-rule approach

International Nuclear Information System (INIS)

Goeke, K.; Bonn Univ.; Castel, B.

1980-01-01

Several useful sum rules associated with isovector giant monopole resonances are calculated for doubly closed shell nuclei. The calculation is based on techniques known from constrained and adiabatic time-dependent Hartree-Fock theories and assume various Skyrme interactions. The results obtained form, together with the compiled literature, the basis for a quantitative description of the RPA strength distribution in terms of energy-weighted moments. These, together with strength distribution properties, are determined by a hierarchy of determinantal relations between moments. The isovector giant monopole resonance turns out to be a rather broad resonance centered at E = 46 Asup(-1/10) MeV with an extended width of more than 16 MeV. The consequences regarding isospin impurities in the nuclear ground state are discussed. (orig.)

Origin of the violation of the Gottfried sum rule

International Nuclear Information System (INIS)

Hwang, W.P.; Speth, J.

1992-01-01

Using generalized Sullivan processes to generate sea-quark distributions of a nucleon at Q 2 =4 GeV 2 , we find that the recent finding by the New Muon Collaboration on the violation of the Gottfried sum rule can be understood quantitatively, including the shape of F 2 p (x)-F 2 n (x) as a function of x. The agreement may be seen as a clear evidence toward the validity of a recent suggestion of Hwang, Speth, and Brown that the sea distributions of a hadron, at low and moderate Q 2 (at least up to a few GeV 2 ), may be attributed primarily to generalized Sullivan processes

xF 3( x,Q 2) Structure Function and Gross-Llewellyn Smith Sum Rule with Nuclear Effect and Higher Twist Correction

International Nuclear Information System (INIS)

Nath, N.M.; Mukharjee, A.; Das, M.K.; Sarma, J.K.

2016-01-01

We present an analysis of the xF 3 (x,Q 2 ) structure function and Gross-Llewellyn Smith(GLS) sum rule taking into account the nuclear effects and higher twist correction. This analysis is based on the results presented in [N.M. Nath, et al, Indian J. Phys. 90 (2016) 117]. The corrections due to nuclear effects predicted in several earlier analysis are incorporated to our results of xF 3 (x,Q 2 ) structure function and GLS sum rule for free nucleon, corrected upto next-next-to-leading order (NNLO) perturbative order and calculate the nuclear structure function as well as sum rule for nuclei. In addition, by means of a simple model we have extracted the higher twist contributions to the non-singlet structure function xF 3 (x,Q 2 ) and GLS sum rule in NNLO perturbative orders and then incorporated them to our results. Our NNLO results along with nuclear effect and higher twist corrections are observed to be compatible with corresponding experimental data and other phenomenological analysis. (paper)

Measurement of the neutron (³He) spin structure functions at low Q²: A connection between the Bjorken and gerasimov-drell-hearn sum rule

Energy Technology Data Exchange (ETDEWEB)

Djawotho, Pibero [College of William and Mary, Williamsburg, VA (United States)

2002-12-01

This dissertation presents results of experiment E94-010 performed at Jefferson Laboratory (simply known as JLab) in Hall A. The experiment aimed to measure the low Q² evolution of the Gerasimov-Drell-Hearn (GDH) integral from Q² = 0.1 to 0.9 GeV². The GDH sum rule at the real photon point provides an important test of Quantum Chromodynamics (QCD). The low Q² evolution of the GDH integral contests various resonance models, Chiral Perturbation Theory ({chi} PT) and lattice QCD calculations, but more importantly, it helps us understand the transition between partonic and hadronic degrees of freedom. At high Q², beyond 1 GeV², the difference of the GDH integrals for the proton and the neutron is related to the Bjorken sum rule, another fundamental test of QCD. In addition, results of the measurements for the spin structure functions g₁ and g₂, cross sections, and asymmetries are presented. E94-010 was the first experiment of its kind at JLab. It used a high-pressure, polarized ³He target with a gas pressure of 10 atm and average target polarization of 35%. For the first time, the polarized electron source delivered an average beam polarization of 70% with a beam current of 15 micro A. The limit on the beam current was only imposed by the target. The experiment required six different beam energies from 0.86 to 5.1 GeV. This was the first time the accelerator ever reached 5.1 GeV. Both High-Resolution Spectrometers of Hall A, used in singles mode, were positioned at 15.5 ° each.

Quantum chromodynamics and the dynamics of hadrons

International Nuclear Information System (INIS)

Brodsky, S.J.

1979-03-01

The application of perturbative quantum chromodynamics to the dynamics of hadrons at short distance is reviewed, with particular emphasis on the role of the hadronic bound state. A number of new applications are discussed, including the modification to QCD scaling violations in structure functions due to hadronic binding; a discussion of coherence and binding corrections to the gluon and sea-quark distributions; QCD radiative corrections to dimensional counting rules for exclusive processes and hadronic form factors at large momentum transfer; generalized counting rules for inclusive processes; the special role of photon-induced reactions in QCD, especially applications to jet production in photon-photon collisions, and photon production at large transverse momentum. Also presented is a short review of the central problems in large P/sub T/ hadronic reactions and the distinguishing characteristics of gluon and quark jets. 163 references

Dependence of Coulomb Sum Rule on the Short Range Correlation by Using Av18 Potential

Science.gov (United States)

Modarres, M.; Moeini, H.; Moshfegh, H. R.

The Coulomb sum rule (CSR) and structure factor are calculated for inelastic electron scattering from nuclear matter at zero and finite temperature in the nonrelativistic limit. The effect of short-range correlation (SRC) is presented by using lowest order constrained variational (LOCV) method and the Argonne Av18 and Δ-Reid soft-core potentials. The effects of different potentials as well as temperature are investigated. It is found that the nonrelativistic version of Bjorken scaling approximately sets in at the momentum transfer of about 1.1 to 1.2 GeV/c and the increase of temperature makes it to decrease. While different potentials do not significantly change CSR, the SRC improves the Coulomb sum rule and we get reasonably close results to both experimental data and others theoretical predictions.

Leptonic decay constants of heavy quarkonia in effective QCD sum rules

International Nuclear Information System (INIS)

Kiselev, V.V.

1992-01-01

The QCD sum rule scheme, which allows one effectively to take into account the heavy quarkonium peculiarities such as nonrelativistic motion and large mass values of the quarks is considered. The phenomenological scaling law is derived for the leptonic constants with the use of the heavy quarkonium mass spectra. The law describes the data on the values of f φ , f ψ and fγ rather good and predicts f B C . 12 refs.; 2 tabs

Subtractions in the Adler sum rule and violation of charge symmetry

International Nuclear Information System (INIS)

Dominguez, C.A.; Moreno, H.; Zepeda, A.

1976-01-01

The consequences of a once-subtracted dispersion relation in the derivation of the Adler sum rule are investigated. It is shown that one can expect a breakdown of charge symmetry, of the isotriplet-current hypothesis, and of scaling of the structure functions. These breakdowns are related to the possible presence of a nonzero subtraction function at asymptotic energies and arbitrary q 2 . We also comment about second-class currents and PCAC (partial conservation of axial-vector current) relations

The off shell ρ endash ω mixing in the QCD sum rules

International Nuclear Information System (INIS)

Hatsuda, T.

1993-01-01

The q 2 dependence of the ρ - ω mixing amplitude is analyzed with the use of the QCD sum rules and the dispersion relation. In going off shell the mixing decreases, changes sign at q 2 ≅ 0.4 m ρ 2 > 0, and is negative in the space-like region. Implications of this result to the isospin breaking part of the nuclear force are discussed

Analysis of the scalar doubly charmed hexaquark state with QCD sum rules

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhi-Gang [North China Electric Power University, Department of Physics, Baoding (China)

2017-09-15

In this article, we study the scalar-diquark-scalar-diquark-scalar-diquark type hexaquark state with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension 16. We obtain a lowest hexaquark mass of 6.60{sup +0.12}{sub -0.09} GeV, which can be confronted with the experimental data in the future. (orig.)

Iso-vector form factors of the delta and nucleon in QCD sum rules

International Nuclear Information System (INIS)

Ozpineci, A.

2012-01-01

Form factors are important non-perturbative properties of hadrons. They give information about the internal structure of the hadrons. In this work, iso-vector axial-vector and iso-vector tensor form factors of the nucleon and the iso-vector axial-vector Δ→N transition form factor calculations in QCD Sum Rules are presented.

The DHG sum rule measured with medium energy photons

International Nuclear Information System (INIS)

Hicks, K.; Ardashev, K.; Babusci, D.

1997-01-01

The structure of the nucleon has many important features that are yet to be uncovered. Of current interest is the nucleon spin-structure which can be measured by doing double-polarization experiments with photon beams of medium energies (0.1 to 2 GeV). One such experiment uses dispersion relations, applied to the Compton scattering amplitude, to relate measurement of the total reaction cross section integrated over the incident photon energy to the nucleon anomalous magnetic moment. At present, no single facility spans the entire range of photon energies necessary to test this sum rule. The Laser-Electron Gamma Source (LEGS) facility will measure the double-polarization observables at photon energies between 0.15--0.47 MeV. Either the SPring8 facility, the GRAAL facility (France), or Jefferson Laboratory could make similar measurements at higher photon energies. A high-precision measurement of the spin-polarizability and the Drell-Hearn-Gerasimov sum rule is now possible with the advent of high-polarization solid HD targets at medium energy polarized photon facilities such as LEGS, GRAAL and SPring8. Other facilities with lower polarization in either the photon beam or target (or both) are also pursuing these measurements because of the high priority associated with this physics. The Spin-asymmetry (SASY) detector that will be used at LEGS has been briefly outlined in this paper. The detector efficiencies have been explored with simulations studies using the GEANT software, with the result that both charged and uncharged pions can be detected with a reasonable efficiency (> 30%) over a large solid angle. Tracking with a TPC, which will be built at LEGS over the next few years, will improve the capabilities of these measurements

The Fubini-Furlan-Rosetti sum rule and related aspects in light of covariant baryon chiral perturbation theory

International Nuclear Information System (INIS)

Bernard, V.; Kubis, B.; Meissner, U.G.

2005-01-01

We analyze the Fubini-Furlan-Rosetti sum rule in the framework of covariant baryon chiral perturbation theory to leading one-loop accuracy and including next-to-leading-order polynomial contributions. We discuss the relation between the subtraction constants in the invariant amplitudes and certain low-energy constants employed in earlier chiral perturbation theory studies of threshold neutral pion photoproduction off nucleons. In particular, we consider the corrections to the sum rule due to the finite pion mass and show that below the threshold they agree well with determinations based on fixed-t dispersion relations. We also discuss the energy dependence of the electric dipole amplitude E 0+ . (orig.)

The Fubini-Furlan-Rosetti sum rule and related aspects in light of covariant baryon chiral perturbation theory

Energy Technology Data Exchange (ETDEWEB)

Bernard, V. [Universite Louis Pasteur, Laboratoire de Physique Theorique, Strasbourg Cedex 2 (France); Kubis, B. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie), Bonn (Germany); Meissner, U.G. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie), Bonn (Germany); Forschungszentrum Juelich, Institut fuer Kernphysik (Theorie), Juelich (Germany)

2005-09-01

We analyze the Fubini-Furlan-Rosetti sum rule in the framework of covariant baryon chiral perturbation theory to leading one-loop accuracy and including next-to-leading-order polynomial contributions. We discuss the relation between the subtraction constants in the invariant amplitudes and certain low-energy constants employed in earlier chiral perturbation theory studies of threshold neutral pion photoproduction off nucleons. In particular, we consider the corrections to the sum rule due to the finite pion mass and show that below the threshold they agree well with determinations based on fixed-t dispersion relations. We also discuss the energy dependence of the electric dipole amplitude E{sub 0+}. (orig.)

Scalar Hidden-Charm Tetraquark States with QCD Sum Rules

Science.gov (United States)

Di, Zun-Yan; Wang, Zhi-Gang; Zhang, Jun-Xia; Yu, Guo-Liang

2018-02-01

In this article, we study the masses and pole residues of the pseudoscalar-diquark-pseudoscalar-antidiquark type and vector-diquark-vector-antidiquark type scalar hidden-charm cu\\bar{c}\\bar{d} (cu\\bar{c}\\bar{s}) tetraquark states with QCD sum rules by taking into account the contributions of the vacuum condensates up to dimension-10 in the operator product expansion. The predicted masses can be confronted with the experimental data in the future. Possible decays of those tetraquark states are also discussed. Supported by the National Natural Science Foundation of China under Grant No. 11375063, the Fundamental Research Funds for the Central Universities under Grant Nos. 2016MS155 and 2016MS133

Frustrated Kinetic Energy, the Optical Sum Rule, and the Mechanism of Superconductivity

International Nuclear Information System (INIS)

Chakravarty, S.; Kee, H.; Abrahams, E.

1999-01-01

The basis of the interlayer tunneling theory of high-temperature superconductivity is that the electronic kinetic energy in a direction perpendicular to the copper-oxygen planes is a substantial fraction of the condensation energy. This issue is critically examined, and it is argued from a rigorous conductivity sum rule that the consequences of this theory are consistent with recent optical and penetration depth measurements. copyright 1999 The American Physical Society

Analytic and algorithmic aspects of generalized harmonic sums and polylogarithms

International Nuclear Information System (INIS)

Ablinger, Jakob; Schneider, Carsten

2013-01-01

In recent three-loop calculations of massive Feynman integrals within Quantum Chromodynamics (QCD) and, e.g., in recent combinatorial problems the so-called generalized harmonic sums (in short S-sums) arise. They are characterized by rational (or real) numerator weights also different from ±1. In this article we explore the algorithmic and analytic properties of these sums systematically. We work out the Mellin and inverse Mellin transform which connects the sums under consideration with the associated Poincare iterated integrals, also called generalized harmonic polylogarithms. In this regard, we obtain explicit analytic continuations by means of asymptotic expansions of the S-sums which started to occur frequently in current QCD calculations. In addition, we derive algebraic and structural relations, like differentiation w.r.t. the external summation index and different multi-argument relations, for the compactification of S-sum expressions. Finally, we calculate algebraic relations for infinite S-sums, or equivalently for generalized harmonic polylogarithms evaluated at special values. The corresponding algorithms and relations are encoded in the computer algebra package HarmonicSums.

Analytic and algorithmic aspects of generalized harmonic sums and polylogarithms

Energy Technology Data Exchange (ETDEWEB)

Ablinger, Jakob; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Bluemlein, Johannes [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2013-01-15

In recent three-loop calculations of massive Feynman integrals within Quantum Chromodynamics (QCD) and, e.g., in recent combinatorial problems the so-called generalized harmonic sums (in short S-sums) arise. They are characterized by rational (or real) numerator weights also different from {+-}1. In this article we explore the algorithmic and analytic properties of these sums systematically. We work out the Mellin and inverse Mellin transform which connects the sums under consideration with the associated Poincare iterated integrals, also called generalized harmonic polylogarithms. In this regard, we obtain explicit analytic continuations by means of asymptotic expansions of the S-sums which started to occur frequently in current QCD calculations. In addition, we derive algebraic and structural relations, like differentiation w.r.t. the external summation index and different multi-argument relations, for the compactification of S-sum expressions. Finally, we calculate algebraic relations for infinite S-sums, or equivalently for generalized harmonic polylogarithms evaluated at special values. The corresponding algorithms and relations are encoded in the computer algebra package HarmonicSums.

Analytic and algorithmic aspects of generalized harmonic sums and polylogarithms

Energy Technology Data Exchange (ETDEWEB)

Ablinger, Jakob; Schneider, Carsten [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040, Linz (Austria); Blümlein, Johannes [Deutsches Elektronen–Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany)

2013-08-15

In recent three-loop calculations of massive Feynman integrals within Quantum Chromodynamics (QCD) and, e.g., in recent combinatorial problems the so-called generalized harmonic sums (in short S-sums) arise. They are characterized by rational (or real) numerator weights also different from ±1. In this article we explore the algorithmic and analytic properties of these sums systematically. We work out the Mellin and inverse Mellin transform which connects the sums under consideration with the associated Poincaré iterated integrals, also called generalized harmonic polylogarithms. In this regard, we obtain explicit analytic continuations by means of asymptotic expansions of the S-sums which started to occur frequently in current QCD calculations. In addition, we derive algebraic and structural relations, like differentiation with respect to the external summation index and different multi-argument relations, for the compactification of S-sum expressions. Finally, we calculate algebraic relations for infinite S-sums, or equivalently for generalized harmonic polylogarithms evaluated at special values. The corresponding algorithms and relations are encoded in the computer algebra package HarmonicSums.

Sum rules and constraints on passive systems

International Nuclear Information System (INIS)

Bernland, A; Gustafsson, M; Luger, A

2011-01-01

A passive system is one that cannot produce energy, a property that naturally poses constraints on the system. A system in convolution form is fully described by its transfer function, and the class of Herglotz functions, holomorphic functions mapping the open upper half-plane to the closed upper half-plane, is closely related to the transfer functions of passive systems. Following a well-known representation theorem, Herglotz functions can be represented by means of positive measures on the real line. This fact is exploited in this paper in order to rigorously prove a set of integral identities for Herglotz functions that relate weighted integrals of the function to its asymptotic expansions at the origin and infinity. The integral identities are the core of a general approach introduced here to derive sum rules and physical limitations on various passive physical systems. Although similar approaches have previously been applied to a wide range of specific applications, this paper is the first to deliver a general procedure together with the necessary proofs. This procedure is described thoroughly and exemplified with examples from electromagnetic theory.

Sum rules and systematics for baryon magnetic moments

International Nuclear Information System (INIS)

Lipkin, H.J.

1983-11-01

The new experimental values of hyperon magnetic moments are compared with sum rules predicted from general quark models. Three difficulties encountered are not easily explained by simple models. The isovector contributions of nonstrange quarks to hyperon moments are smaller than the corresponding contribution to nucleon moments, indicating either appreciable configuration mixing in hyperon wave functions and absent in nucleons or an additional isovector contribution beyond that of valence quarks; e.g. from a pion cloud. The large magnitude of the THETA - moment may indicate that the strange quark contribution to the THETA moments is considerably larger than the value μ(Λ) predicted by simple models which have otherwise been very successful. The set of controversial values from different experiments of the Σ - moment include a value very close to -(1/2)μ(Σ + ) which would indicate that strange quarks do not contribute at all to the Σ moments. (author)

Sum rules and systematics for baryon magnetic moments

International Nuclear Information System (INIS)

Lipkin, H.J.

1984-01-01

The new experimental values of hyperon magnetic moments are compared with sum rules predicted from general quark models. Three difficulties encountered are not easily explained by simple models. The isovector contributions of nonstrange quarks to hyperon moments are smaller than the corresponding contribution to nucleon moments, indicating either appreciable configuration mixing in hyperon wave functions and absent in nucleons or an additional isovector contribution beyond that of valence quarks, e.g. from a pion cloud. The large magnitude of the Ψ - moment may indicate that the strange quark contribution to the Ψ moments is considerably larger than the value μ(Λ) predicted by simple models which have otherwise been very successful. The set of controversial values from different experiments of the Σ - moment include a value very close to -1/2μ(Σ + ) which would indicate that strange quarks do not contribute at all to the Σ moments. (orig.)

Composite Finite Sums

KAUST Repository

Alabdulmohsin, Ibrahim M.

2018-03-07

In this chapter, we extend the previous results of Chap. 2 to the more general case of composite finite sums. We describe what composite finite sums are and how their analysis can be reduced to the analysis of simple finite sums using the chain rule. We apply these techniques, next, on numerical integration and on some identities of Ramanujan.

Composite Finite Sums

KAUST Repository

Alabdulmohsin, Ibrahim M.

2018-01-01

In this chapter, we extend the previous results of Chap. 2 to the more general case of composite finite sums. We describe what composite finite sums are and how their analysis can be reduced to the analysis of simple finite sums using the chain rule. We apply these techniques, next, on numerical integration and on some identities of Ramanujan.

Lectures on quantum chromodynamics

CERN Document Server

Smilga, Andrei

2001-01-01

Quantum chromodynamics is the fundamental theory of strong interactions. It is a physical theory describing Nature. Lectures on Quantum Chromodynamics concentrates, however, not on the phenomenological aspect of QCD; books with comprehensive coverage of phenomenological issues have been written. What the reader will find in this book is a profound discussion on the theoretical foundations of QCD with emphasis on the nonperturbative formulation of the theory: What is gauge symmetry on the classical and on the quantum level? What is the path integral in field theory? How to define the path integ

Measurement of the Neutron (³He) Spin Structure at Low Q² and the Extended Gerasimov-Drell-Hearn Sum Rule

Energy Technology Data Exchange (ETDEWEB)

Kominis, Ioannis [Princeton Univ., NJ (United States)

2001-01-01

This thesis presents the results of E-94010, an experiment at Thomas Jefferson National Accelerator Facility (TJNAF) designed to study the spin structure of the neutron at low momentum transfer, and to test the “extended” Gerasimov-Drell-Hearn (GDH) sum rule. The first experiment of its kind, it was performed in experimental Hall-A of TJNAF using a new polarized ³He facility. It has recently been shown that the GDH sum rule and the Bjorken sum rule are both special examples of a more general sum rule that applies to polarized electron scattering off nucleons. This generalized sum rule, due to Ji and Osborne, reduces to the GDH sum rule at Q² = 0 and to the Bjorken sum rule at Q² >> 1 GeV². By studying the Q² evolution of the extended GDH sum, one learns about the transition from quark-like behavior to hadronic-like behavior. We measured inclusive polarized cross sections by scattering high energy polarized electrons off the new TJNAF polarized ³He target with both longitudinal and transverse target orientations. The high density ³He target, based on optical pumping and spin exchange, was used as an effective neutron target. The target maintained a polarization of about 35% at beam currents as high as 151tA. We describe the precision ³He polarimetry leading to a systematic uncertainty of the target polarization of 4% (relative). A strained GaAs photocathode was utilized in the polarized electron gun, which provided an electron beam with a polarization of about 70%, known to 3% (relative). By using six different beam energies (between 0.86 and 5.06 GeV) and a fixed scattering angle of 15.5°, a wide kinematic coverage was achieved, with 0.02 GeV²< Q² <1 GcV² and 0.5 GeV< W < 2.5 GeV for the squared momentum transfer and invariant mass, respectively. From the measured cross sections we extract the ³He spin structure functions g$3 He

Subtracted Dispersion Relations for In-medium Meson Correlators in QCD Sum Rules

Energy Technology Data Exchange (ETDEWEB)

Florkowski, W; Broniowski, W [The H. Niewodniczanski Institute of Nuclear Physics, Cracow (Poland)

1999-01-01

We analyze subtracted dispersion relations for meson correlators at finite baryon density and temperature. Such relations are needed for QCD sum rules. We point out that importance of scattering terms, as well as finite, well-defined subtraction constants. Both are necessary for consistency, in particular for the equality of the longitudinal and transverse correlators in the limit of the vanishing three-momentum of mesons relative to the medium. We present detailed calculations in various mesonic channels of the Fermi gas of nucleons. (author)

On the twist-2 contributions to polarized structure functions and new sum rules

International Nuclear Information System (INIS)

Bluemlein, J.; Kochelev, N.

1996-03-01

The twist-2 contributions to the polarized structure functions in deep inelastic lepton-hadron scattering are calculated including the exchange of weak bosons and using both the operator product expansion and the covariant parton model. A new relation between two structure functions leading to a sequence of new sum rules is found. The light quark mass corrections to the structure functions are derived in lowest order QCD. (orig.)

A sum rule approach to the violation of Dashen's theorem

International Nuclear Information System (INIS)

Moussallam, B.

1999-01-01

A classic sum rule by Das et al. is extended to seven of the low-energy constant K i , introduced by Urech, which parameterizes electromagnetic corrections at chiral order O(e 2 p 2 ). Using the spurion formalism, a simple convolution representation is shown to hold and the structure in terms of the chiral renormalization scale, QCD renormalization scale and the QED gauge parameter is displayed. The role of the resonances is studied as providing rational interpolants to relevant QCD n-point functions in the Euclidean domain. A variety of asymptotic constraints must be implemented which have phenomenological consequences. A current assumption concerning the dominance of the lowest-lying resonances is shown clearly to fail in some cases. (author)

Strong interactions and quantum chromodynamics at the leading logarithm approximation

International Nuclear Information System (INIS)

Mantrach, A.

1982-11-01

This thesis is a contribution to the study of Quantum Chromodynamics (QCD) at the leading logarithm approximation (LLA). We have used the interpretation of the LLA in terms of the generalized parton model to propose tests of elementary processes of QCD in large transverse momentum photoproduction reactions. We have used the LLA to sum gluon radiation effects induced in high energy hadronic reactions. We have obtained this way a rise of the nucleon-nucleon total cross section of 15 mb from 60 GeV to 540 GeV. We have exploited the existence of a preconfinement transition in the LLA to study scaling violations in the framework of the dual parton model [fr

Experimental tests of quantum chromodynamics

International Nuclear Information System (INIS)

Dorfan, J.

1987-04-01

Experimental tests of quantum chromodynamics are discussed in the e + e - continuum, in pp and anti p p collisions, in measurements of α/sub s/ from Υ decays, in deep inelastic lepton scattering, and in the measurement of the photon structure function. A large body of data relating to the testing of quantum chromodynamics is reviewed, showing qualitative agreement between the data from a wide range of processes and QCD. 66 refs., 79 figs

Renormalization group analysis of B →π form factors with B -meson light-cone sum rules

Science.gov (United States)

Shen, Yue-Long; Wei, Yan-Bing; Lü, Cai-Dian

2018-03-01

Within the framework of the B -meson light-cone sum rules, we review the calculation of radiative corrections to the three B →π transition form factors at leading power in Λ /mb. To resum large logarithmic terms, we perform the complete renormalization group evolution of the correlation function. We employ the integral transformation which diagonalizes evolution equations of the jet function and the B -meson light-cone distribution amplitude to solve these evolution equations and obtain renormalization group improved sum rules for the B →π form factors. Results of the form factors are extrapolated to the whole physical q2 region and are compared with that of other approaches. The effect of B -meson three-particle light-cone distribution amplitudes, which will contribute to the form factors at next-to-leading power in Λ /mb at tree level, is not considered in this paper.

Isospin-breaking nuclear forces in QCD sum rules and Nolen-Schiffer anomaly

International Nuclear Information System (INIS)

Drukarev, E.G.; Ryskin, M.G.

1994-01-01

We use QCD sum rules to investigate isospin-breaking effects in nuclear matter. The isospin-breaking condensate left angle NM vertical stroke uu-dd vertical stroke NM right angle is shown to play an important role. In a reasonable model the neutron becomes (0.9±0.6) MeV more bound than the proton, providing a possible solution for the Nolen-Schiffer anomaly. The various contributions to the value are analysed. The possible consequences for nucleon-nucleon isospin-breaking forces are discussed. ((orig.))

Determination of baryon and baryonic resonance masses from QCD sum rules. Strange baryons

International Nuclear Information System (INIS)

Belyaev, V.M.; Ioffe, B.L.

1982-01-01

The mass differences in baryonic octet Jsup(P)=1/2sup(+), decuplet Jsup(P)=3/2sup(+) and in octet Jsup(P)=3/2sup(-) are calculated basing on the QCD sum rules. The mass differences are expressed through two QCD parameters: the strange current qUark mass and the value of the quark condensate. At the properly chosen values of these parameters all of the mass differences are in a good agreement with experiment

Sum rule measurements of the spin-dependent compton amplitude (nucleon spin structure at Q2 = 0)

International Nuclear Information System (INIS)

Babusci, D.; Giordano, G.; Baghaei, H.; Cichocki, A.; Blecher, M.; Breuer, M.; Commeaux, C.; Didelez, J.P.; Caracappa, A.; Fan, Q.

1995-01-01

Energy weighted integrals of the difference in helicity-dependent photo-production cross sections (σ 1/2 - σ 3/2 ) provide information on the nucleon's Spin-dependent Polarizability (γ), and on the spin-dependent part of the asymptotic forward Compton amplitude through the Drell-Hearn-Gerasimov (DHG) sum rule. (The latter forms the Q 2 =0 limit of recent spin-asymmetry experiments in deep-inelastic lepton-scattering.) There are no direct measurements of σ 1/2 or σ 3/2 , for either the proton or the neutron. Estimates from current π-photo-production multipole analyses, particularly for the proton-neutron difference, are in good agreement with relativistic-l-loop Chiral calculations (χPT) for γ but predict large deviations from the DHG sum rule. Either (a) both the 2-loop corrections to the Spin-Polarizability are large and the existing multipoles are wrong, or (b) modifications to the Drell-Hearn-Gerasimov sum rule are required to fully describe the isospin structure of the nucleon. The helicity-dependent photo-reaction amplitudes, for both the proton and the neutron, will be measured at LEGS from pion-threshold to 470 MeV. In these double-polarization experiments, circularly polarized photons from LEGS will be used with SPHICE, a new frozen-spin target consisting of rvec H · rvec D in the solid phase. Reaction channels will be identified in SASY, a large detector array covering about 80% of 4π. A high degree of symmetry in both target and detector will be used to minimize systematic uncertainties

Quasi-particles and quantum condensate in the Quantum Chromodynamics

International Nuclear Information System (INIS)

Herrmann, J.

1987-01-01

The non-perturbative structure of Quantum Chromodynamics is investigated with the help of a generalisation of the formalism of Green's functions according to Gorkow and Nambu's studies in the theory of superconductivity methods. Taking into account the existence of the gluon condensation, the self-energy of the gluon-quasi-particles in the form of integral-equations is calculated with the help of modified rules for Feynman diagrams. The form of these equations implies the existence of particular solutions with an energy gap in the spectrum of the quasi-particles and a phase transition at a critical momentum. (author)

On the conductance sum rule for the hierarchical edge states of the fractional quantum hall effect

International Nuclear Information System (INIS)

Ma Zhongshui; Chen Yixin; Su Zhaobin.

1993-09-01

The conductance sum rule for the hierarchical edge channel currents of a Fractional Quantum Hall Effect state is derived analytically within the Haldane-Halperin hierarchy scheme. We provide also an intuitive interpretation for the hierarchical drift velocities of the edge excitations. (author). 12 refs

Spectral sum rules and magneto-roton as emergent graviton in fractional quantum Hall effect

Energy Technology Data Exchange (ETDEWEB)

Golkar, Siavash; Nguyen, Dung X.; Son, Dam T. [Enrico Fermi Institute, James Franck Institute and Department of Physics,University of Chicago, Chicago, Illinois 60637 (United States)

2016-01-05

We consider gapped fractional quantum Hall states on the lowest Landau level when the Coulomb energy is much smaller than the cyclotron energy. We introduce two spectral densities, ρ{sub T}(ω) and ρ̄{sub T}(ω), which are proportional to the probabilities of absorption of circularly polarized gravitons by the quantum Hall system. We prove three sum rules relating these spectral densities with the shift S, the q{sup 4} coefficient of the static structure factor S{sub 4}, and the high-frequency shear modulus of the ground state μ{sub ∞}, which is precisely defined. We confirm an inequality, first suggested by Haldane, that S{sub 4} is bounded from below by |S−1|/8. The Laughlin wavefunction saturates this bound, which we argue to imply that systems with ground state wavefunctions close to Laughlin’s absorb gravitons of predominantly one circular polarization. We consider a nonlinear model where the sum rules are saturated by a single magneto-roton mode. In this model, the magneto-roton arises from the mixing between oscillations of an internal metric and the hydrodynamic motion. Implications for experiments are briefly discussed.

Quasielastic 3Hp and 3Hep scattering at intermediate energies and Glauber sum rules

International Nuclear Information System (INIS)

Blinov, A.V.; Vanyushin, I.A.; Grechko, V.E.

1984-01-01

Differential cross sections and average energy losses of fast protons in reactions p +3 H→psub(F)+X and p+ 3 He → psub(F)+X are studied making use of the ITEP liquid hydrogen bubble chamber of 80-cm diameter exposed to 2.5-GeV/c tritium nuclei (the kinetic energy of the incident protons in the nucleus rest frame Tsub(p)=0.318 GeV) and to 5-GeV/c 3 He nuclei (Tsub(p)=0.978 GeV). The experimental results are compared to predictions based on the sum rules for differential cross sections and average energy losses in the Glauber-Sitenko multiple scattering theory using the completeness condition for the wave functions of the nuclear excited states and the locality of the nuclear potential. The theory and the data are in good agreement at momentum of 2.5 GeV/c. Inconsistence between the Glauber sum rule predictions and the 5 GeV/c data is attributed to the Δ-isobar production in the intermediate state. It is found that possible six-quark bag admixture in the 3 H and 3 He nuclei does not exceed 5%

A probabilistic approach of sum rules for heat polynomials

International Nuclear Information System (INIS)

Vignat, C; Lévêque, O

2012-01-01

In this paper, we show that the sum rules for generalized Hermite polynomials derived by Daboul and Mizrahi (2005 J. Phys. A: Math. Gen. http://dx.doi.org/10.1088/0305-4470/38/2/010) and by Graczyk and Nowak (2004 C. R. Acad. Sci., Ser. 1 338 849) can be interpreted and easily recovered using a probabilistic moment representation of these polynomials. The covariance property of the raising operator of the harmonic oscillator, which is at the origin of the identities proved in Daboul and Mizrahi and the dimension reduction effect expressed in the main result of Graczyk and Nowak are both interpreted in terms of the rotational invariance of the Gaussian distributions. As an application of these results, we uncover a probabilistic moment interpretation of two classical integrals of the Wigner function that involve the associated Laguerre polynomials. (paper)

gDsDK*0 and gBsDK*0 coupling constants in QCD sum rules

International Nuclear Information System (INIS)

Şahin, S; Sundu, H; Azizi, K

2012-01-01

In the present study, we calculate the strong coupling constants g D s DK* 0 (800) and g B s DK* 0 (800) within the three-point QCD sum rules approach. We evaluate the correlation function of the considered vertices taking into account both D[B] and K* 0 (800) mesons as off-shell states.

Scaling properties of S-wave level density for heavy quarkonium from QCD sum rules

International Nuclear Information System (INIS)

Kiselev, V.V.

1994-01-01

In the framework of a specific scheme of the QCD sum rules for S-wave of the heavy quarkonium one derives an expression, relating the energetic density of quarkonium states and universal characteristics in the heavy quarkonium physics, such as the difference between the masses of a heavy quark Q and meson and the number of heavy quarkonium levels below the threshold decay. 20 refs

Status of the B0(S)-bar {B}0(S) Mixing from QCD Spectral Sum Rules

Science.gov (United States)

Narison, Stephan

2002-07-01

In this talk, I summarize new results 1 obtained from QCD spectral sum rules (QSSR), on the bag constant parameters entering in the analysis of the B0(s)-bar {B}0(s) mass-differences. Taking the average of the results from the Laplace and moment sum rules, one obtains to order α s: fB√ {hat {B}_B} ˜= (229 ± 55) GeV, fB{s}√ {BB_{s}}/f_B√ {BB} ˜= 1.18 ± 0.03, in units where fπ = 130.7 MeV. Combined with the experimental data on the mass-differences ΔMd,s, one obtains the constraint on the CKM weak mixing angle: |Vts/Vtd|2 ≥ 20.2(1.3). Alternatively, using the weak mixing angle from the analysis of the unitarity triangle and the data on ΔMd, one predicts ΔMs = 18.3(2.1) ps-1 in agreement with the present experimental lower bound and within the reach of Tevatron 2.

Thermal Properties of Light Tensor Mesons via QCD Sum Rules

Directory of Open Access Journals (Sweden)

K. Azizi

2015-01-01

Full Text Available The thermal properties of f2(1270, a2(1320, and K2*(1430 light tensor mesons are investigated in the framework of QCD sum rules at finite temperature. In particular, the masses and decay constants of the light tensor mesons are calculated taking into account the new operators appearing at finite temperature. The numerical results show that, at the point at which the temperature-dependent continuum threshold vanishes, the decay constants decrease with amount of (70–85% compared to their vacuum values, while the masses diminish about (60–72% depending on the kinds of the mesons under consideration. The results obtained at zero temperature are in good consistency with the experimental data as well as the existing theoretical predictions.

Impact of Duality Violations on Spectral Sum Rule analyses

International Nuclear Information System (INIS)

Cata, Oscar

2007-01-01

Recent sum rule analyses on the two-point correlator have led to significant discrepancies in the values found for the OPE condensates, most dramatically in the dimension eight condensate and to a lesser extent in the dimension six one [R. Barate et al., ALEPH Collaboration, Eur. Phys. J. C 4 (1998) 409; K. Ackerstaff et al., OPAL Collaboration, Eur. Phys. J. C 7 (1999) 571, (arXiv:hep-ex/9808019); S. Peris, B. Phily and E. de Rafael, Phys. Rev. Lett. 86 (2001) 14, (arXiv:hep-ph/0007338); S. Friot, D. Greynat and E. de Rafael, JHEP 0410 (2004) 043, (arXiv:hep-ph/0408281); M. Davier, L. Girlanda, A. Hocker and J. Stern, Phys. Rev. D 58 (1998) 096014, (arXiv:hep-ph/9802447); B.L. Ioffe and K.N. Zyablyuk, Nucl. Phys. A 687 (2001) 437, (arXiv:hep-ph/0010089). K.N. Zyablyuk, Eur. Phys. J. C 38 (2004) 215, (arXiv:hep-ph/0404230); J. Bijnens, E. Gamiz and J. Prades, JHEP 0110 (2001) 009, (arXiv:hep-ph/0108240); C.A. Dominguez and K. Schilcher, Phys. Lett. B 581 (2004) 193, (arXiv:hep-ph/0309285); J. Rojo and J. I. Latorre, JHEP 0401 (2004) 055, (arXiv:hep-ph/0401047); V. Cirigliano, E. Golowich and K. Maltman, Phys. Rev. D 68 (2003) 054013, (arXiv:hep-ph/0305118); S. Ciulli, C. Sebu, K. Schilcher and H. Spiesberger, Phys. Lett. B 595 (2004) 359, (arXiv:hep-ph/0312212). S. Narison, (arXiv:hep-ph/0412152)]. Precise knowledge of these condensates is of relevance in kaon decays [M. Knecht, S. Peris and E. de Rafael, Phys. Lett. B 457 (1999) 227, (arXiv:hep-ph/9812471); J.F. Donoghue and E. Golowich, Phys. Lett. B 478 (2000) 172, (arXiv:hep-ph/9911309); M. Knecht, S. Peris and E. de Rafael, Phys. Lett. B 508 (2001) 117, (arXiv:hep-ph/0102017)] and therefore it seems mandatory to assess the actual impact of what is commonly neglected in spectral sum rules, most prominently the issue of duality violations. We will explicitly compute them in a toy model and show that they are a priori non-negligible

Perturbative corrections to Λ{sub b}→Λ form factors from QCD light-cone sum rules

Energy Technology Data Exchange (ETDEWEB)

Wang, Yu-Ming [Fakultät für Physik, Universität Wien,Boltzmanngasse 5, 1090 Vienna (Austria); Physik Department T31, Technische Universität München,James-Franck-Straße 1, D-85748 Garching (Germany); Shen, Yue-Long [College of Information Science and Engineering, Ocean University of China,Songling Road 238, Qingdao, Shandong 266100 (China)

2016-02-29

We compute radiative corrections to Λ{sub b}→Λ from factors, at next-to-leading logarithmic accuracy, from QCD light-cone sum rules with Λ{sub b}-baryon distribution amplitudes. Employing the diagrammatic approach factorization of the vacuum-to-Λ{sub b}-baryon correlation function is justified at leading power in Λ/m{sub b}, with the aid of the method of regions. Hard functions entering the factorization formulae are identical to the corresponding matching coefficients of heavy-to-light currents from QCD onto soft-collinear effective theory. The universal jet function from integrating out the hard-collinear fluctuations exhibits richer structures compared with the one involved in the factorization expressions of the vacuum-to-B-meson correlation function. Based upon the QCD resummation improved sum rules we observe that the perturbative corrections at O(α{sub s}) shift the Λ{sub b}→Λ from factors at large recoil significantly and the dominant contribution originates from the next-to-leading order jet function instead of the hard coefficient functions. Having at hand the sum rule predictions for the Λ{sub b}→Λ from factors we further investigate several decay observables in the electro-weak penguin Λ{sub b}→Λ ℓ{sup +}ℓ{sup −} transitions in the factorization limit (i.e., ignoring the “non-factorizable' hadronic effects which cannot be expressed in terms of the Λ{sub b}→Λ from factors), including the invariant mass distribution of the lepton pair, the forward-backward asymmetry in the dilepton system and the longitudinal polarization fraction of the leptonic sector.

Inhomogeneous spectral moment sum rules for the retarded Green function and self-energy of strongly correlated electrons or ultracold fermionic atoms in optical lattices

International Nuclear Information System (INIS)

Freericks, J. K.; Turkowski, V.

2009-01-01

Spectral moment sum rules are presented for the inhomogeneous many-body problem described by the fermionic Falicov-Kimball or Hubbard models. These local sum rules allow for arbitrary hoppings, site energies, and interactions. They can be employed to quantify the accuracy of numerical solutions to the inhomogeneous many-body problem such as strongly correlated multilayered devices, ultracold atoms in an optical lattice with a trap potential, strongly correlated systems that are disordered, or systems with nontrivial spatial ordering such as a charge-density wave or a spin-density wave. We also show how the spectral moment sum rules determine the asymptotic behavior of the Green function, self-energy, and dynamical mean field when applied to the dynamical mean-field theory solution of the many-body problem. In particular, we illustrate in detail how one can dramatically reduce the number of Matsubara frequencies needed to solve the Falicov-Kimball model while still retaining high precision, and we sketch how one can incorporate these results into Hirsch-Fye quantum Monte Carlo solvers for the Hubbard (or more complicated) models. Since the solution of inhomogeneous problems is significantly more time consuming than periodic systems, efficient use of these sum rules can provide a dramatic speed up in the computational time required to solve the many-body problem. We also discuss how these sum rules behave in nonequilibrium situations as well, where the Hamiltonian has explicit time dependence due to a driving field or due to the time-dependent change in a parameter such as the interaction strength or the origin of the trap potential.

Dispersion theory and sum rules for the non-minimum phase problem in optical spectroscopy

International Nuclear Information System (INIS)

Peiponen, Kai-Erik

2009-01-01

Dispersion relations and sum rules for integer powers of an optical response function are given in the case of the non-minimum phase problem. These relations were obtained using the concept of the Hilbert transform and Blaschke product. The theory presented in this paper is useful both in basic and applied studies of non-minimum phase functions in optics, and also other fields of physics such as high energy physics.

Gottfried sum rule and mesonic exchanges in deuteron

International Nuclear Information System (INIS)

Kaptari, L.P.

1991-01-01

Recent NMC data on the experimental value of the Gottfried Sum are discussed. It is shown that the Gottfried Sum is sensitive to the nuclear structure corrections, viz. themesonic exchanges and binding effects. A new estimation of the Gottfried Sum is given. The obtained result is close to the quark-parton prediction of 1/3. 11 refs.; 2 figs

Hermitian relativity, chromodynamics and confinement

International Nuclear Information System (INIS)

Treder, H.J.

1983-01-01

The extension of the Riemann metrics of General Relativity to the complex domain (substitution of the symmetry conditions for the fundamental tensor, the affinity and the Ricci curvature by the conditions of hermicity) leads to a 'Generalized Theory of Gravity' (Einstein) describing the Newton-Einstein gravodynamics combined with the chromodynamics of quarks. The interaction of gravodynamics and chromodynamics implied by the Einstein-Schroedinger field equations of the hermitian relativity theory enforces the 'confinement'. The 'confinement' prevents the gravitational potential from divergence which would result in the lack of a Riemann space-time metric

Splitting of electrons and violation of the Luttinger sum rule

Science.gov (United States)

Quinn, Eoin

2018-03-01

We obtain a controlled description of a strongly correlated regime of electronic behavior. We begin by arguing that there are two ways to characterize the electronic degree of freedom, either by the canonical fermion algebra or the graded Lie algebra su (2 |2 ) . The first underlies the Fermi liquid description of correlated matter, and we identify a regime governed by the latter. We exploit an exceptional central extension of su (2 |2 ) to employ a perturbative scheme recently developed by Shastry and obtain a series of successive approximations for the electronic Green's function. We then focus on the leading approximation, which reveals a splitting in two of the electronic dispersion. The Luttinger sum rule is violated, and a Mott metal-insulator transition is exhibited. We offer a perspective.

Adler Function, Bjorken Sum Rule, and the Crewther Relation to Order αs4 in a General Gauge Theory

International Nuclear Information System (INIS)

Baikov, P. A.; Chetyrkin, K. G.; Kuehn, J. H.

2010-01-01

We compute, for the first time, the order α s 4 contributions to the Bjorken sum rule for polarized electron-nucleon scattering and to the (nonsinglet) Adler function for the case of a generic color gauge group. We confirm at the same order a (generalized) Crewther relation which provides a strong test of the correctness of our previously obtained results: the QCD Adler function and the five-loop β function in quenched QED. In particular, the appearance of an irrational contribution proportional to ζ 3 in the latter quantity is confirmed. We obtain the commensurate scale equation relating the effective strong coupling constants as inferred from the Bjorken sum rule and from the Adler function at order α s 4 .

Adler-type sum rule, charge symmetry and neutral current in general multi-triplet model

International Nuclear Information System (INIS)

Katuya, Mituaki; Baba, Yoshimitsu; Fujii, Kanji

1975-01-01

We derive Adler-type sum rule extended to general multi-triplet model. Paying attention to roles of the colour degree of freedom, we discuss the charge symmetry property of the weak charged current and the structure functions for ν(ν - )+N→l(l - )+X, and also the structure of the neutral current. A comment is given on implications in our theory of Koike and Konuma's result on the neutral hadronic current. (auth.)

Parton distributions, the Gottfried sum rule and the W charge asymmetry

International Nuclear Information System (INIS)

Martin, A.D.; Stirling, W.J.; Roberts, R.G.

1990-09-01

Preliminary data from the New Muon Collaboration (NMC) allow a precise evaluation of I p-n (x) from a given integral formula for values of x down to 0.004. As x → 0, this integral should converge to a value I p-n (0) = 1/3 (Gottfried sum rule) if the light sea-quark distributions are equal. The NMC value I p-n (0.004) = 0.23 ± 0.03, though appearing to be well short of 1/3, is quite consistent with modern estimates for parton distributions extracted from a wide range of data. These parton distributions are also found to reproduce the W ± rapidity asymmetry recently measured by a European collaboration. (author)

Strong interaction at finite temperature

Indian Academy of Sciences (India)

Quantum chromodynamics; finite temperature; chiral perturbation theory; QCD sum rules. PACS Nos 11.10. ..... at finite temperature. The self-energy diagrams of figure 2 modify it to ..... method of determination at present. Acknowledgement.

Density-dependent Hartree-Fock response functions in quasi-elastic electron scattering on 12C and related sum rules

International Nuclear Information System (INIS)

Kohno, M.

1983-01-01

We report fully consistent calculations of the longitudinal and transverse response functions of the inclusive quasi-elastic electron scattering on 12 C in the Hartree-Fock approximation. The distorted wave for the outgoing nucleon is constructed from the same non-local Hartree-Fock field as in the ground-state description. Thus the orthogonality and Pauli principle requirements are naturally satisfied. The theoretical prediction, based on the standard density-dependent effective interaction (GO force), shows a good correspondence to the experimental data. Since the calculated response functions automatically satisfy the relevant sum rule, this work illuminates the well-known puzzle concerning the longitudinal part, which remains to be solved. We study the energy-weighted sum rules and discuss effects beyond the mean-field approximation. Meson-exchange-current contributions to the transverse response function are also estimated and found to be small due to cancellations among them. (orig.)

Medium modifications of mesons. Chiral symmetry restoration, in-medium QCD sum rules for D and ρ mesons, and Bethe-Salpeter equations

Energy Technology Data Exchange (ETDEWEB)

Hilger, Thomas Uwe

2012-04-11

The interplay of hadron properties and their modification in an ambient nuclear medium on the one hand and spontaneous chiral symmetry breaking and its restoration on the other hand is investigated. QCD sum rules for D and B mesons embedded in cold nuclear matter are evaluated. We quantify the mass splitting of D- anti D and B- anti B mesons as a function of the nuclear matter density and investigate the impact of various condensates in linear density approximation. The analysis also includes D{sub s} and D{sup *}{sub 0} mesons. QCD sum rules for chiral partners in the open-charm meson sector are presented at nonzero baryon net density or temperature. We focus on the differences between pseudo-scalar and scalar as well as vector and axial-vector D mesons and derive the corresponding Weinberg type sum rules. Based on QCD sum rules we explore the consequences of a scenario for the ρ meson, where the chiral symmetry breaking condensates are set to zero whereas the chirally symmetric condensates remain at their vacuum values. The complementarity of mass shift and broadening is discussed. An alternative approach which utilizes coupled Dyson-Schwinger and Bethe-Salpeter equations for quark-antiquark bound states is investigated. For this purpose we analyze the analytic structure of the quark propagators in the complex plane numerically and test the possibility to widen the applicability of the method to the sector of heavy-light mesons in the scalar and pseudo-scalar channels, such as the D mesons, by varying the momentum partitioning parameter. The solutions of the Dyson-Schwinger equation in the Wigner-Weyl phase of chiral symmetry at nonzero bare quark masses are used to investigate a scenario with explicit but without dynamical chiral symmetry breaking.

Effect of Coulomb interaction on the X-ray magnetic circular dichroism spin sum rule in rare earths

NARCIS (Netherlands)

Teramura, Y; Tanaka, A; Thole, BT; Jo, T

A deviation from the spin sum rule, which relates the integrated intensity of the X-ray magnetic circular dichroism (MCD) signal to the expectation value of the spin operator S-z ((S-z)), is numerically calculated in the case of the 3d --> 4f absorption for rare earths from the trivalent Ce to Tm.

Applications of quantum chromodynamics

International Nuclear Information System (INIS)

Field, R.D.

1979-01-01

Perturbative application of the theory of Quantum Chromodynamics (QCQ) are examined and compared with experimental data. Particular emphasis is placed on understanding the similarities and differences between the QCD results and the expectations of the naive parton model

Surface thickness effects and splitting of multipole excitations in deformed nuclei. [Sum rule, hydrodynamic model

Energy Technology Data Exchange (ETDEWEB)

Christillin, P [Scuola Normale Superiore, Pisa (Italy); Lipparini, E; Stringari, S [Dipartimento Matematica e Fisica, Trento, Italy

1978-09-25

A sum-rule approach is used to study the influence of surface thickness upon the splitting of dipole and isoscalar quadrupole energies in deformed nuclei. It is shown that hydrodynamic model results are recovered in the case of a deformed skin thickness. A constant skin thickness leads in the dipole case to slightly different predictions which seem in better agreement with experiments. The splitting of the isoscalar quadrupole mode is not sensitive to the surface thickness shape.

Normalization sum rule and spontaneous breaking of U(N) invariance in random matrix ensembles

International Nuclear Information System (INIS)

Canali, C.M.; Kravtsov, V.E.

1995-03-01

It is shown that the two-level correlation function R(s,s') in the invariant random matrix ensembles (RME) with soft confinement exhibits a ''ghost peak'' at s approx. -s'. This lifts the sum rule prohibition for the level number variance to have a Poisson-like term var(n) = ηn that is typical of RME with broken U(N) symmetry. Thus we conclude that the U(N) invariance is broken spontaneously in the RME with soft confinement, η playing the role of an order-parameter. (author). 16 refs, 1 fig

Analyzing Bs - anti Bs mixing. Non-perturbative contributions to bag parameters from sum rules

International Nuclear Information System (INIS)

Mannel, T.; Pivovarov, A.A.; Russian Academy of Sciecnes, Moscow

2007-03-01

We use QCD sum rules to compute matrix elements of the ΔB=2 operators appearing in the heavy-quark expansion of the width difference of the B s mass eigenstates. Our analysis includes the leading-order operators Q and Q S , as well as the subleading operators R 2 and R 3 , which appear at next-to-leading order in the 1/m b expansion. We conclude that the violation of the factorization approximation for these matrix elements due to non-perturbative vacuum condensates is as low as 1-2%. (orig.)

Dispersive approach to the axial anomaly. The t'Hooft's principle and QCD sum rules

International Nuclear Information System (INIS)

Horejsi, J.; Teryaev, O.; Veretin, O.; )

1997-01-01

The dispersive approach to the axial anomaly is revisited. Considering the familiar VVA triangle graph, the anomalous Ward identity is proved in the case of the arbitrary external momenta. It is also commented on a recent claim that the anomaly pole in QCD fails to reproduce the pion pole. In this connection it is emphasized that there is no need to introduce a massless axial meson in the chiral limit. In the framework of QCD sum rules method a constraint for the Borel transform of relevant form factors imposed by the anomaly is considered [ru

Sum rule and hydrodynamic analyses of the velocity autocorrelation function in strongly coupled plasmas

International Nuclear Information System (INIS)

Nagano, Seido; Ichimaru, Setsuo

1980-01-01

The memory function for the velocity autocorrelation function in a strongly coupled, one-component plasma is analyzed in the short time and long time domains, respectively, with the aid of the frequency-moment sum rules and the hydrodynamic consideration evoking the idea of the generalized Stokes friction. A series of interpolation schemes with successively improved accuracies are then introduced. Numerical investigations of those interpolation schemes clarify the physical origin of the three different types of the velocity autocorrelation function observed in the molecular dynamics simulation at different regimes of the coupling constant. (author)

Determination of {alpha}{sub s} from Gross-Llewellyn Smith sum rule by accounting for infrared renormalon

Energy Technology Data Exchange (ETDEWEB)

Contreras, C [Department of Physics, Universidad Tecn. Federico Santa Maria, Valparaiso (Chile); Cvetic, G [Department of Physics, Universidad Tecn. Federico Santa Maria, Valparaiso (Chile); Jeong, K S [Department of Physics, Korea Advanced Institute of Science and Technology, Daejon (Korea, Republic of); Lee, Taekoon [Department of Physics, Korea Advanced Institute of Science and Technology, Daejon (Korea, Republic of)

2003-08-01

We recapitulate the method which resums the truncated perturbation series of a physical observable in a way which takes into account the structure of the leading infrared renormalon. We apply the method to the Gross-Llewellyn Smith (GLS) sum rule. By confronting the obtained result with the experimentally extracted GLS value, we determine the value of the QCD coupling parameter, which turns out to agree with the present world average.

How Precisely can we Determine the $\\piNN$ Coupling Constant from the Isovector GMO Sum Rule?

CERN Document Server

Loiseau, B; Thomas, A W

1999-01-01

The isovector GMO sum rule for zero energy forward pion-nucleon scattering iscritically studied to obtain the charged pion-nucleon coupling constant usingthe precise negatively charged pion-proton and pion-deuteron scattering lengthsdeduced recently from pionic atom experiments. This direct determination leadsto a pseudoscalar charged pion-nucleon coupling constant of 14.23 +- 0.09(statistic) +- 0.17 (systematic). We obtain also accurate values for thepion-nucleon scattering lengths.

Fixed poles in electromagnetic processes and modification of Adler's neutrino sum rule due to quark anomalous magnetic moment

International Nuclear Information System (INIS)

Khare, A.

1975-01-01

We show that Adler's sum rule for neutrino scattering and Bjorken's inequality for electron-proton scattering are modified if quark has finite anomalous magnetic moment ksub(q). We also show that if ksub(q) is nonzero, there exist fixed poles in spin-flip Compton scattering as well as in charged pion photoproduction. (auth.)

Charmonium and quantum chromodynamics

CERN Document Server

Vainshtein, A I; Zakharov, V I; Novikov, V A; Okun, Lev Borisovich; Shifman, M A

1977-01-01

The properties of levels of charmonium-the bound system consisting of the charmed quark c and antiquark c-are considered. A brief review is given of the experimental data on the different levels of charmonium, and the classification of the states and their decays are discussed. Of the latter, radiative transitions between levels and the annihilation of levels of charmonium to give photons (or lepton pairs) and also light hadrons ( pi , eta and K mesons), are paid the most attention. Such decays have fundamental significance, inasmuch as they are connected in the most direct manner with the properties of quarks and their interactions. The theoretical foundation of the review is quantum chromodynamics-the theory of the interaction of colored quarks and gluons. The review contains the results of calculations performed in the framework of quantum chromodynamics and pertaining to the annihilation decays of charmonium levels and also to other phenomena: photoproduction of charmed particles, leptonic decays of charm...

Quantum chromodynamics with advanced computing

International Nuclear Information System (INIS)

Kronfeld, A S

2008-01-01

We survey results in lattice quantum chromodynamics from groups in the USQCD Collaboration. The main focus is on physics, but many aspects of the discussion are aimed at an audience of computational physicists

The Q2-Dependence of the Gross-Llewellyn Smith Sum Rule and of the Parton Distributions

International Nuclear Information System (INIS)

Kataev, A.L.; AN SSSR, Moscow; Sidorov, A.V.

1994-01-01

We describe the results of our recent work on the determination of the value of the parameter Λ and of the Q 2 -dependence of the Gross-Llewellyn Smith (GLS) sum rule from the experimental data of the CCFR collaboration on neutrino-nucleon deep inelastic scattering, using the Jacobi polynomials QCD analysis. The new information on the Q 2 -dependence of the parton distributions is presented. 37 refs., 3 figs., 3 tabs

Perturbative tests of quantum chromodynamics

International Nuclear Information System (INIS)

Michael, C.

1978-01-01

A review is given of perturbation theory results for quantum chromodynamics and of tests in deep inelastic lepton scattering, electron-positron annihilation, hadronic production of massive dileptons and hadronic large-momentum-transfer processes. (author)

Analysis of diffractive pd to Xd and pp to Xp interactions and test of the finite-mass sum rule

CERN Document Server

Akimov, Y; Golovanov, L B; Goulianos, K; Gross, D; Malamud, E; Melissinos, A C; Mukhin, S; Nitz, D; Olsen, S; Sticker, H; Tsarev, V A; Yamada, R; Zimmerman, P

1976-01-01

The first moment finite mass sum rule is tested by utilising cross- sections for pp to Xp extracted from recent Fermilab data on pd to Xd and also comparing with CERN ISR data. The dependences on M/sub x//sup 2/, t and s are also discussed. (11 refs).

Introduction to quantum chromodynamics

International Nuclear Information System (INIS)

Shellard, R.C.

1983-06-01

A pedagogical over view of Quantum Chromodynamics, emphasying its pertubative as well as its non pertubative aspects is given. The renormalization group; aplications of QCD to parton models, gauge theories in a lattice, instantons and the theta angle and problems associated to chiral symmetry breaking are studied. (Author) [pt

Matrix elements of four-quark operators relevant to life time difference ΔΓBs from QCD sum rules

International Nuclear Information System (INIS)

Huang, C.S.; Zhang Ailin; Zhu, S.L.

2001-01-01

We extract the matrix elements of four-quark operators O L,S relevant to the B s and anti B s life time difference from QCD sum rules. We find that the vacuum saturation approximation works reasonably well, i.e., within 10%. We discuss the implications of our results and compare them with a recent lattice QCD determination. (orig.)

Analysis of the scalar, axialvector, vector, tensor doubly charmed tetraquark states with QCD sum rules

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhi-Gang; Yan, Ze-Hui [North China Electric Power University, Department of Physics, Baoding (China)

2018-01-15

In this article, we construct the axialvector-diquark-axialvector-antidiquark type currents to interpolate the scalar, axialvector, vector, tensor doubly charmed tetraquark states, and study them with QCD sum rules systematically by carrying out the operator product expansion up to the vacuum condensates of dimension 10 in a consistent way, the predicted masses can be confronted with the experimental data in the future. We can search for those doubly charmed tetraquark states in the Okubo-Zweig-Iizuka super-allowed strong decays to the charmed-meson pairs. (orig.)

Sum rules for the ed - NN scattering reactions and microscopic potential field-theoretical approach

International Nuclear Information System (INIS)

Machivariani, A.I.

1996-01-01

The connections between the equal-time commutators of nucleon and photon field-operators and relativistic potential approach of ed - NN scattering equations is established. Namely, it is demonstrated that: 1) equal-time commutator between nucleon field operators generated completeness condition for NN interaction functions, 2) the off-mass shell contributions in γd - NN exchange currents or in microscopic NN potential are determined by equal time commutator between nucleon field operator and photon or nucleon source operators, and 3) equal-time commutators between source operators produce sum rules for same vertex functions and effective potentials [ru

Sum rules application to reflectometry of X-ray resonant radiation for magnetic multilayer investigation

International Nuclear Information System (INIS)

Smekhova, A.G.; Andreeva, M.A.

2005-01-01

One elaborated the general formalism on the basis of which one derived the clear expressions for reflection factors of X-ray radiation with a circular polarization from medium magnetized both within surface plane and within reflection plane both for grazing angles and for high grazing angles. The asymmetry of reflection spectra for right- and left-polarized radiation is shown to depend both on nondiagonal components of a susceptibility tensor and on other components in contrast to absorption spectra, so the sum rule to determine the orbital and the spin magnetic moments can not be applied directly to the experimental spectra of reflection [ru

Quantum chromodynamics

CERN Document Server

Neubert, Matthias

1996-01-01

Quantum chromodynamics (QCD) is the fundamental theory of the strong interactions. It is local, non-abelian gauge theory descripting the interactions between quarks and gluons, the constituents of hadrons. In these lectures, the basic concepts and ph will be introduced in a pedagogical way. Topics will include : asymptotically free partons, colour and confinement ; non-abelian gauge invariance and quantization ; the running coupling constant ; deep-inelastic scattering and scaling violations ; th chiral and heavy-quark symmetries. Some elementary knowledge of field theory, abelian gauge invariance and Feynman diagrams will be helpful in following the course.

Correlation of zero-point energy with molecular structure and molecular forces. 3. Approximation for H/D isotope shifts and linear frequency sum rule

International Nuclear Information System (INIS)

Oi, T.; Ishida, T.

1984-01-01

The approximation methods for the zero-point energy (ZPE) previously developed using the Lanczo's tau method have been applied to the shifts in ZPE due to hydrogen isotope substitutions. Six types of approximation methods have been compared and analyzed on the basis of a weighing function Ω(lambda) varies as lambda/sup k/ and the actual eigenvalue shift spectra. The method generated by the most general optimzation treatment yields a predictable and generally satisfactory precision of the order of 1% or better. A linear frequency sum rule has been derived, which approximately holds for the sets of isotopic molecules which satisfy the second-order frequency sum rule. 19 references, 3 figures, 3 tables

L-edge sum rule analysis on 3d transition metal sites: from d10 to d0 and towards application to extremely dilute metallo-enzymes.

Science.gov (United States)

Wang, Hongxin; Friedrich, Stephan; Li, Lei; Mao, Ziliang; Ge, Pinghua; Balasubramanian, Mahalingam; Patil, Daulat S

2018-03-28

According to L-edge sum rules, the number of 3d vacancies at a transition metal site is directly proportional to the integrated intensity of the L-edge X-ray absorption spectrum (XAS) for the corresponding metal complex. In this study, the numbers of 3d holes are characterized quantitatively or semi-quantitatively for a series of manganese (Mn) and nickel (Ni) complexes, including the electron configurations 3d 10 → 3d 0 . In addition, extremely dilute (edge jump region; and (2) by adding an inert tracer to the sample that provides a prominent spectral feature to replace the weak edge jump for intensity normalization. In this publication, we present for the first time: (1) L-edge sum rule analysis for a series of Mn and Ni complexes that include electron configurations from an open shell 3d 0 to a closed shell 3d 10 ; (2) a systematic analysis on the uncertainties, especially on that from the edge jump, which was missing in all previous reports; (3) a clearly-resolved edge jump between pre-L 3 and post-L 2 regions from an extremely dilute sample; (4) an evaluation of an alternative normalization standard for L-edge sum rule analysis. XAS from two copper (Cu) proteins measured using a conventional semiconductor X-ray detector are also repeated as bridges between Ni complexes and dilute Ni enzymes. The differences between measuring 1% Cu enzymes and measuring edge sum rule analysis to virtually any 3d metal complex and any dilute biological samples that contain 3d metals.

Two-photon collisions and short-distance tests of quantum chromodynamics

International Nuclear Information System (INIS)

Brodsky, S.J.

1978-12-01

The physics of two-photon collisions in e +- storage rings is reviewed with emphasis on the predictions of perturbative quantum chromodynamics for high transverse momentum reactions. It is noted that because of the remarkable scaling properties predicted by the theory, two-photon collisions may be proved one of the cleanest tests of the quantum chromodynamics picture of short distance hadron dynamics. In order to contrast these predictions for photon-induced reactions with those for incident hadrons, predictions from quantum chromodynamics for hadron structure functions and form factors at large momentum transfer are also discussed. 55 references

QCD sum rule approach to the s→dγ contribution to the Ω-→Ξ-γ radiative decay

International Nuclear Information System (INIS)

Nielsen, M.; Barreiro, L.A.; Escobar, C.O.; Rosenfeld, R.

1996-01-01

QCD sum rules are used to calculate the contribution of the short-distance single-quark transition s→dγ to the amplitudes of the hyperon radiative decay Ω - →Ξ - γ. We reevaluate the Wilson coefficient of the effective operator responsible for this transition. We obtain a branching ratio which is comparable to the unitarity limit. copyright 1996 The American Physical Society

The Adler-Weisberger and Goldberger-Miyazawa-Oehme sum rules as probes of constraints from analyticity and chiral symmetry in dynamical models for pion-nucleon scattering

International Nuclear Information System (INIS)

Kondratyuk, S.; Kubodera, K.; Myhrer, F.; Scholten, O.

2004-01-01

The Adler-Weisberger and Goldberger-Miyazawa-Oehme sum rules are calculated within a relativistic, unitary and crossing symmetric dynamical model for pion-nucleon scattering using two different methods: (1) by evaluating the scattering amplitude at the corresponding low-energy kinematics and (2) by evaluating the sum-rule integrals with the calculated total cross section. The discrepancy between the results of the two methods provides a measure of the breaking of analyticity and chiral symmetry in the model. The contribution of the Δ resonance, including its dressing with meson loops, is discussed in some detail and found to be small

The spin-dependent structure function of the proton g(1)(p) and a test of the Bjorken sum rule

Czech Academy of Sciences Publication Activity Database

Alekseev, M.; Alexakhin, V. Yu.; Alexandrov, Yu.; Alexeev, G. D.; Amoroso, A.; Austregisilio, A.; Badelek, B.; Balestra, F.; Ball, J.; Barth, J.; Baum, G.; Bedfer, Y.; Bernhard, J.; Bertini, R.; Bettinelli, M.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bravar, A.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M.; Chaberny, D.; Chiosso, M.; Chung, S.U.; Cicuttin, A.; Colantoni, M.; Cotic, D.; Crespo, M.; Dalla Torre, S.; Das, S.; Dasgupta, S. S.; Denisov, O.; Dhara, L.; Diaz, V.; Donskov, S.; Doshita, N.; Duic, V.; Dünnweber, W.; Efremov, A.V.; El Alaoui, A.; Eversheim, P.; Eyrich, W.; Faessler, M.; Ferrero, A.; Filin, A.; Finger, M.; Finger jr., M.; Fischer, H.; Franco, C.; Friedrich, J.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.; Gazda, R.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gnesi, I.; Gobbo, B.; Goertz, S.; Grabmüller, S.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Haas, F.; von Harrach, D.; Hasegawa, T.; Heinsius, F.; Hermann, R.; Herrmann, F.; Hess, C.; Hinterberger, F.; Horikawa, N.; Höppner, Ch.; d'Hose, N.; Ilgner, C.; Ishimoto, S.; Ivanov, O.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jasinski, P.; Jegou, G.; Joosten, R.; Kabuss, E.; Käfer, W.; Kang, D.; Ketzer, B.; Khaustov, G.; Khokhlov, Y.; Kisselev, Y.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J.; Kolosov, V.; Kondo, K.; Königsmann, K.; Konopka, R.; Konorov, I.; Konstantinov, V.; Korzenev, A.; Kotzinian, A.; Kouznetsov, O.; Kowalik, K.; Krämer, M.; Kral, A.; Kroumchtein, Z.; Kuhn, R.; Kunne, F.; Kurek, K.; Lauser, L.; Le Goff, J.; Lednev, A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Liska, T.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G.; Mann, A.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Massmann, F.; Matsuda, T.; Meyer, W.; Michigami, T.; Mikhailov, Y.; Moinester, M.; Mutter, A.; Nagaytsev, A.; Nagel, T.; Nassalski, J.; Negrini, S.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.; Nunes, A.S.; Olshevsky, A.; Ostrick, M.; Padee, A.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pawlukiewicz-Kaminska, B.; Perevalova, E.; Pesaro, G.; Peshekhonov, D.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V.; Pontecorvo, G.; Pretz, J.; Quintans, C.; Rajotte, J.; Ramos, S.; Rapatsky, V.; Reicherz, G.; Richter, A.; Robinet, F.; Rocco, E.; Rondio, E.; Ryabchikov, D.; Samoylenko, V.; Sandacz, A.; Santos, H.; Sapozhnikov, M.; Sarkar, S.; Savin, I.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schlütter, T.; Schmitt, L.; Schopferer, S.; Schröder, W.; Shevchenko, O.; Siebert, H.; Silva, L.; Sinha, L.; Sissakian, A.; Slunecka, M.; Smirnov, G.; Sosio, S.; Sozzi, F.; Srnka, Aleš; Stolarski, M.; Sulc, M.; Sulej, R.; Takekawa, S.; Tessaro, S.; Tessarotto, F.; Teufel, A.; Tkatchev, L.; Uhl, S.; Uman, I.; Virius, M.; Vlassov, N.; Vossen, A.; Weitzel, Q.; Windmolders, R.; Wislicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zhao, J.; Zhuravlev, N.; Zvyagin, A.

2010-01-01

Roč. 690, č. 5 (2010), s. 466-472 ISSN 0370-2693 R&D Projects: GA MŠk ME 492 Institutional research plan: CEZ:AV0Z20650511 Keywords : deep inelastic scattering * structure function * QCD analysis * Bjorken sum rule Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 5.255, year: 2010

QCD sum rule study of hidden-charm pentaquarks

Energy Technology Data Exchange (ETDEWEB)

Chen, Hua-Xing; Cui, Er-Liang [Beihang University, School of Physics and Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beijing (China); Chen, Wei; Steele, T.G. [University of Saskatchewan, Department of Physics and Engineering Physics, Saskatoon, Saskatchewan (Canada); Liu, Xiang [Lanzhou University, School of Physical Science and Technology, Lanzhou (China); Lanzhou University and Institute of Modern Physics of CAS, Research Center for Hadron and CSR Physics, Lanzhou (China); Zhu, Shi-Lin [Peking University, School of Physics and State Key Laboratory of Nuclear Physics and Technology, Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Peking University, Center of High Energy Physics, Beijing (China)

2016-10-15

We study the mass spectra of hidden-charm pentaquarks having spin J = (1)/(2)/(3)/(2)/(5)/(2) and quark contents uudc anti c. We systematically construct all the relevant local hidden-charm pentaquark currents, and we select some of them to perform QCD sum rule analyses. We find that the P{sub c}(4380) and P{sub c}(4450) can be identified as hidden-charm pentaquark states composed of an anti-charmed meson and a charmed baryon. Besides them, we also find (a) the lowest-lying hidden-charm pentaquark state of J{sup P} = 1/2{sup -} has the mass 4.33{sup +0.17}{sub -0.13} GeV, while the one of J{sup P} = 1/2{sup +} is significantly higher, that is, around 4.7-4.9 GeV; (b) the lowest-lying hidden-charm pentaquark state of J{sup P} = 3/2{sup -} has the mass 4.37{sup +0.18}{sub -0.13} GeV, consistent with the P{sub c}(4380) of J{sup P} = 3/2{sup -}, while the one of J{sup P} = 3/2{sup +} is also significantly higher, that is, above 4.6 GeV; (c) the hidden-charm pentaquark state of J{sup P} = 5/2{sup -} has a mass around 4.5-4.6 GeV, slightly larger than the P{sub c}(4450) of J{sup P} = 5/2{sup +}. (orig.)

The Adler-Weisberger sum rule and the sigma-Commutator for the Kaon-Neutron system

International Nuclear Information System (INIS)

Rodriguez-Vargas, A.M.; Violini, G.

1980-01-01

The axial coupling constant is determined from Kp and Kn Adler-Weisberger sum rule, in correspondence with different anti K N unphysical region parameterizations. Moreover a new calculation of the sigma-term is presented. It is shown that by using Kn data it is possible to reduce considerably the error on sigma sup(KK)sub(NN) with respect to the analogous calculation for Kp, but that an accurate determination requires a good value for the psub(3/2) anti K N scattering length. By preferring the solutions which lead to a positive sigma-term, one obtains sigma sup(KK)sub(NN) = 638 +- 438 MeV. (orig.) 891 HSI/orig. 892 HIS

Measurement of αs(Q2) from the Gross endash Llewellyn Smith Sum Rule

International Nuclear Information System (INIS)

Johnson, R.A.; Vakili, M.; Kim, J.H.; Arroyo, C.G.; Bazarko, A.O.; Conrad, J.; King, B.J.; Lefmann, W.C.; McNulty, C.; Mishra, S.R.; Quintas, P.Z.; Romosan, A.; Schellman, H.; Sciulli, F.J.; Seligman, W.G.; Shaevitz, M.H.; Spentzouris, P.; Stern, E.G.; Bernstein, R.H.; Lamm, M.J.; Marsh, W.; McFarland, K.S.; Yu, J.; Bolton, T.; Naples, D.; Barbaro, L. de; Harris, D.A.; Barbaro, P. de; Bodek, A.; Budd, H.; Sakumoto, W.K.; Yang, U.K.; Kinnel, T.; Smith, W.H.

1998-01-01

We extract a set of values for the Gross endash Llewellyn Smith sum rule at different values of 4-momentum transfer squared (Q 2 ), by combining revised CCFR neutrino data with data from other neutrino deep-inelastic scattering experiments for 1 2 2 /c 2 . A comparison with the order α 3 s theoretical predictions yields a determination of α s at the scale of the Z -boson mass of 0.114± 0.009 0.012 . This measurement provides a new and useful test of perturbative QCD at low Q 2 , because of the low uncertainties in the higher order calculations. copyright 1998 The American Physical Society

On the anomalous skin effect in metals. II. Some aspects of superconductors, sum-rule applications and limits of this technique

Energy Technology Data Exchange (ETDEWEB)

Drangeid, K E; Sommerhalder, R [IBM Research Lab., Zurich (Switzerland)

1976-03-02

Based on previous work applying to normal conducting metals, an analog network model for superconducting metals is developed. The reciprocal surface impendance associated with this model is used as a response function in connection with the Kramers-Kronig relations and the sum rule to compute electrodynamic properties of superconductors.

Near-threshold deuteron photodisintegration: An indirect determination of the Gerasimov-Drell-Hearn sum rule and forward spin polarizability (γ0) for the deuteron at low energies

International Nuclear Information System (INIS)

Ahmed, M. W.; Blackston, M. A.; Perdue, B. A.; Tornow, W.; Weller, H. R.; Norum, B.; Sawatzky, B.; Prior, R. M.; Spraker, M. C.

2008-01-01

It is shown that a measurement of the analyzing power obtained with linearly polarized γ-rays and an unpolarized target can provide an indirect determination of two physical quantities. These are the Gerasimov-Drell-Hearn (GDH) sum rule integrand for the deuteron and the sum rule integrand for the forward spin polarizability (γ 0 ) near photodisintegration threshold. An analysis of data for the d(γ-vector,n)p reaction and other experiments is presented. A fit to the world data analyzed in this manner gives a GDH integral value of -603±43μb between the photodisintegration threshold and 6 MeV. This result is the first confirmation of the large contribution of the 1 S 0 (M1) transition predicted for the deuteron near photodisintegration threshold. In addition, a sum rule value of 3.75±0.18 fm 4 for γ 0 is obtained between photodisintegration threshold and 6 MeV. This is a first indirect confirmation of the leading-order effective field theory prediction for the forward spin-polarizability of the deuteron

Measurement of the lepton τ spectral functions and applications to quantum chromodynamic

International Nuclear Information System (INIS)

Hoecker, A.

1997-01-01

This thesis presents measurements of the τ vector (V) and axial-vector (A) hadronic spectral functions and phenomenological studies in the framework of quantum chromodynamics (QCD). Using the hypothesis of conserved vector currents (CVC), the dominant two- and four-pion vector spectral functions are compared to the corresponding cross sections from e + e - annihilation. A combined fit of the pion form factor from τ decays and e + e - data is performed using different parametrizations. The mass and the width of the ρ ± (770) and the ρ 0 (770) are separately determined in order to extract possible isospin violating effects. The mass and width differences are measured to be M ρ ± (770) - M ρ 0 (770) =(0.0±1.0) MeV/c 2 and Γ ρ ± (770) - Γ ρ 0 (770) =(0.1 ± 1.9) MeV/c 2 . Several QCD chiral sum rules involving the difference (V - A) of the spectral functions are compared to their measurements. The Borel-transformed Das-Mathur-Okubo sum rule is used to measure the pion polarizability to be α E =(2.68±0.91) x 10 -4 fm 3 . The τ vector and axial-vector hadronic widths and certain spectral moments are exploited to measure α s and non-perturbative contributions at the τ mass scale. The best, and experimentally and theoretically most robust, determination of α s (M τ ) is obtained from the inclusive (V + A) fit that yields α s (M τ )= 0.348±0.017 giving α s (M Z )=0.1211 ± 0.0021 after the evolution to the mass of the Z boson. The approach of the Operator Product Expansion (OPE) is tested experimentally by means of an evolution of the τ hadronic width to masses smaller that the τ mass. Using the difference (V - A) of the spectral functions allows one to directly measure the dominant non-perturbative OPE dimension to be D=6.9±0.5. The vector spectral functions are used to improve the precision of the experimental determination of the hadronic contribution to the anomalous magnetic moment of the muon a μ =(g - 2)/2 and to the running of the QED

Sum rules and spectral density flow in QCD and in superconformal theories

Directory of Open Access Journals (Sweden)

Costantini Antonio

2014-01-01

Full Text Available We discuss the signature of the anomalous breaking of the superconformal symmetry in N${\\cal N}$ = 1 super Yang Mills theory and its manifestation in the form of anomaly poles. Moreover, we describe the massive deformations of the N${\\cal N}$ = 1 theory and the spectral densities of the corresponding anomaly form factors. These are characterized by spectral densities which flow with the mass deformation and turn the continuum contributions from the two-particle cuts of the intermediate states into poles, with a single sum rule satisfied by each component. The poles can be interpreted as signaling the exchange of a composite axion/dilaton/dilatino (ADD multiplet in the effective Lagrangian. We conclude that global anomalous currents characterized by a single flow in the perturbative picture always predict the existence of composite interpolating fields.

Correlation Matrix Renormalization Theory: Improving Accuracy with Two-Electron Density-Matrix Sum Rules.

Science.gov (United States)

Liu, C; Liu, J; Yao, Y X; Wu, P; Wang, C Z; Ho, K M

2016-10-11

We recently proposed the correlation matrix renormalization (CMR) theory to treat the electronic correlation effects [Phys. Rev. B 2014, 89, 045131 and Sci. Rep. 2015, 5, 13478] in ground state total energy calculations of molecular systems using the Gutzwiller variational wave function (GWF). By adopting a number of approximations, the computational effort of the CMR can be reduced to a level similar to Hartree-Fock calculations. This paper reports our recent progress in minimizing the error originating from some of these approximations. We introduce a novel sum-rule correction to obtain a more accurate description of the intersite electron correlation effects in total energy calculations. Benchmark calculations are performed on a set of molecules to show the reasonable accuracy of the method.

Third family corrections to tri-bimaximal lepton mixing and a new sum rule

International Nuclear Information System (INIS)

Antusch, Stefan; King, Stephen F.; Malinsky, Michal

2009-01-01

We investigate the theoretical stability of the predictions of tri-bimaximal neutrino mixing with respect to third family wave-function corrections. Such third family wave-function corrections can arise from either the canonical normalisation of the kinetic terms or renormalisation group running effects. At leading order both sorts of corrections can be subsumed into a single universal parameter. For hierarchical neutrinos, this leads to a new testable lepton mixing sum rule s=rcosδ+2/3 a (where s,r,a describe the deviations of solar, reactor and atmospheric mixing angles from their tri-bimaximal values, and δ is the observable Dirac CP phase) which is stable under all leading order third family wave-function corrections, as well as Cabibbo-like charged lepton mixing effects

Classical algebraic chromodynamics

International Nuclear Information System (INIS)

Adler, S.L.

1978-01-01

I develop an extension of the usual equations of SU(n) chromodynamics which permits the consistent introduction of classical, noncommuting quark source charges. The extension involves adding a singlet gluon, giving a U(n) -based theory with outer product P/sup a/(u,v) = (1/2)(d/sup a/bc + if/sup a/bc)(u/sup b/v/sup c/ - v/sup b/u/sup c/) which obeys the Jacobi identity, inner product S (u,v) = (1/2)(u/sup a/v/sup a/ + v/sup a/u/sup a/), and with the n 2 gluon fields elevated to algebraic fields over the quark color charge C* algebra. I show that provided the color charge algebra satisfies the condition S (P (u,v),w) = S (u,P (v,w)) for all elements u,v,w of the algebra, all the standard derivations of Lagrangian chromodynamics continue to hold in the algebraic chromodynamics case. I analyze in detail the color charge algebra in the two-particle (qq, qq-bar, q-barq-bar) case and show that the above consistency condition is satisfied for the following unique (and, interestingly, asymmetric) choice of quark and antiquark charges: Q/sup a//sub q/ = xi/sup a/, Q/sup a//sub q/ = xi-bar/sup a/ + delta/sup a/0(n/2)/sup 3/2/1, with xi/sup a/xi/sup b/ = (1/2)(d/sup a/bc + if/sup a/bc) xi/sup c/, xi-bar/sup a/xi-bar/sup b/ = -(1/2)(d/sup a/bc - if/sup a/bc) xi-bar/sup c/. The algebraic structure of the two-particle U(n) force problem, when expressed on an appropriately diagonalized basis, leads for all n to a classical dynamics problem involving an ordinary SU(2) Yang-Mills field with uniquely specified classical source charges which are nonparallel in the color-singlet state. An explicit calculation shows that local algebraic U(n) gauge transformations lead only to a rigid global rotation of axes in the overlying classical SU(2) problem, which implies that the relative orientations of the classical source charges have physical significance

The relation between the photonuclear E1 sum rule and the effective orbital g-factor

Energy Technology Data Exchange (ETDEWEB)

Bentz, Wolfgang E-mail: bentz@keyaki.cc.u-tokai.ac.jp; Arima, Akito

2004-05-17

The connection between the enhancement factor (1+{kappa}) of the photonuclear E1 sum rule and the orbital angular momentum g-factor (g{sub l}) of a bound nucleon is investigated in the framework of the Landau-Migdal theory for isospin asymmetric nuclear matter. Special emphasis is put on the role of gauge invariance to establish the {kappa}-g{sub l} relation. By identifying the physical processes which are taken into account in {kappa} and g{sub l}, the validity and limitations of this relation will be discussed. The connections to the collective excitations and to nuclear Compton scattering are also shown.

Gold-plated mode of CP-violation in decays of B{sub c} meson from QCD sum rules

Energy Technology Data Exchange (ETDEWEB)

Kiselev, V V [Russian State Research Center, ' Institute for High Energy Physics' , Protvino, Moscow Region, 142281 (Russian Federation)

2004-10-01

A model-independent method based on the triangle ideology is implemented to extract the CKM-matrix angle {gamma} in the decays of the doubly heavy long-lived meson B{sub c}. We analyse a colour structure of diagrams and conditions to reconstruct two reference triangles by tagging the flavour and CP eigenstates of D{sup 0} - D{sup 0}bar mesons in the fixed exclusive channels. The characteristic branching ratios are evaluated in the framework of QCD sum rules.

Vacuum expectation values of high-dimensional operators and their contributions to the Bjorken and Ellis-Jaffe sum rules

International Nuclear Information System (INIS)

Oganesian, A.G.

1998-01-01

A method is proposed for estimating unknown vacuum expectation values of high-dimensional operators. The method is based on the idea that the factorization hypothesis is self-consistent. Results are obtained for all vacuum expectation values of dimension-7 operators, and some estimates for dimension-10 operators are presented as well. The resulting values are used to compute corrections of higher dimensions to the Bjorken and Ellis-Jaffe sum rules

Perturbative quantum chromodynamics

International Nuclear Information System (INIS)

Reya, E.

1979-12-01

The author gives an introductory lecture into quantum chromodynamics. After a general introduction into the concept of color and a presentation of the QCD Lagrangian the renormalization group and the effective coupling constant are introduced. Then the calculation of deep inelastic lepton-nucleon scattering, scaling violations, factorization at parton distribution, hadronic production of massive lepton pairs and heavy quark flavours, semi-inclusive processes, high-psub(T) reactions, the total hadronic e + e - cross sections, and jets in e + e - annihilation is described. (HSI)

Analysis of the mass and width of the X*(3860) with QCD sum rules

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhi-Gang [North China Electric Power University, Department of Physics, Baoding (China)

2017-10-15

In this article, we tentatively assign the X*(3860) to be the Cγ{sub 5} x γ{sub 5}C-type scalar tetraquark state and study its mass and width with the QCD sum rules; special attention is paid to calculating the hadronic coupling constants G{sub Xη{sub cπ}} and G{sub XDD} concerning the tetraquark state. We obtain the values M{sub X} = 3.86 ± 0.09 GeV and Γ{sub X} = 202 ± 146 MeV, which are consistent with the experimental data. The numerical result supports assigning the X*(3860) to be the Cγ{sub 5} x γ{sub 5}C-type scalar tetraquark state. (orig.)

Sum rule for bremsstrahlung cross section for 6Li in the resonating-group method

International Nuclear Information System (INIS)

Lodhi, M.A.K.; Wood, K.E.

1982-01-01

In the method of resonating-group structure, the wave function of 6 Li is assumed to have a single channel of alpha and deuteron substructures in the ground state. It is shown that the intercluster exchange of nucleons is an important effect which causes significant change in the root mean square radius and the dipole transition cross section. Due to lack of symmetry in space coordinates of 6 Li, the dipole operator is not identical to the mean square operator for this sum rule calculation and is expected to display like behavior in similar systems. It is also shown that the deuteron substructure in this nucleus is substantially larger than the alpha substructure. (orig.)

Behaviour at x = 0,1, sum rules and parametrizations for structure functions beyond the leading order

International Nuclear Information System (INIS)

Lopez, C.

1981-01-01

We write the simplest possible parametrizations of deep inelastic structure functions which satisfy the following requirements: (i) exact compatibility with QCD at the endpoints x = 0,1, to second order; (ii) fulfilment of sum rules to second order; (iii) leading and subleading Regge behaviour. In all we find that, including the QCD scale Λ, such parametrizations describe in a simple manner the three standard functions W 1 , W 2 , W 3 for all x, Q 2 in terms of four to six parameters only (two more if allowing for higher twists). (orig.)

Classical chromodynamics

International Nuclear Information System (INIS)

Carson, L.J.

1980-01-01

Quantum chromodynamics (QCD) is currently our only candidate for a theory of strong-interaction dynamics. But the evidence for it is very scanty. Indeed, QCD has only been experimentally verified in its predictions of scaling violation in deep inelastic neutrino scattering. Yet, research continues on QCD because it is based on a beautiful idea, namely the incorporation of observed particle symmetries via local gauge invariance. Nevertheless QCD, a quantum field theory in 3 + 1 dimensions is still without solution. The sheer difficulty in solving the full quantum problem has led some to various approximations, in the hopes of shedding light on the structure of the theory. (orig./FKS)

Light front quantum chromodynamics: Towards phenomenology

Indian Academy of Sciences (India)

Light front dynamics; quantum chromodynamics; deep inelastic scattering. PACS Nos 11.10. ... What makes light front dynamics appealing from high energy phenomenology point of view? .... given in terms of Poincarй generators by. MВ = W P ...

Beyond standard quantum chromodynamics

International Nuclear Information System (INIS)

Brodsky, S.J.

1995-09-01

Despite the many empirical successes of QCD, there are a number of intriguing experimental anomalies that have been observed in heavy flavor hadroproduction, in measurements of azimuthal correlations in deep inelastic processes, and in measurements of spin correlations in hadronic reactions. Such phenomena point to color coherence and multiparton correlations in the hadron wavefunctions and physics beyond standard leading twist factorization. Two new high precision tests of QCD and the Standard Model are discussed: classical polarized photoabsorption sum rules, which are sensitive to anomalous couplings and composite structure, and commensurate scale relations, which relate physical observables to each other without scale or scheme ambiguity. The relationship of anomalous couplings to composite structure is also discussed

Masses of open-flavour heavy-light hybrids from QCD sum-rules

Energy Technology Data Exchange (ETDEWEB)

Ho, J. [Department of Physics and Engineering Physics, University of Saskatchewan,Saskatoon, SK, S7N 5E2 (Canada); Harnett, D. [Department of Physics, University of the Fraser Valley,Abbotsford, BC, V2S 7M8 (Canada); Steele, T.G. [Department of Physics and Engineering Physics, University of Saskatchewan,Saskatoon, SK, S7N 5E2 (Canada)

2017-05-29

We use QCD Laplace sum-rules to predict masses of open-flavour heavy-light hybrids where one of the hybrid’s constituent quarks is a charm or bottom and the other is an up, down, or strange. We compute leading-order, diagonal correlation functions of several hybrid interpolating currents, taking into account QCD condensates up to dimension-six, and extract hybrid mass predictions for all J{sup P}∈{0"±, 1"±}, as well as explore possible mixing effects with conventional quark-antiquark mesons. Within theoretical uncertainties, our results are consistent with a degeneracy between the heavy-nonstrange and heavy-strange hybrids in all J{sup P} channels. We find a similar mass hierarchy of 1{sup +}, 1{sup −}, and 0{sup +} states (a 1{sup +} state lighter than essentially degenerate 1{sup −} and 0{sup +} states) in both the charm and bottom sectors, and discuss an interpretation for the 0{sup −} states. If conventional meson mixing is present the effect is an increase in the hybrid mass prediction, and we estimate an upper bound on this effect.

Pion form factor in QCD sum rules, local duality approach, and O(A2) fractional analytic perturbation theory

International Nuclear Information System (INIS)

Bakulev, Alexander P.

2010-01-01

Using the results on the electromagnetic pion Form Factor (FF) obtained in the O(α s ) QCD sum rules with non-local condensates [A.P. Bakulev, A.V. Pimikov, and N.G. Stefanis, Phys. Rev. D79 (2009) 093010] we determine the effective continuum threshold for the local duality approach. Then we apply it to construct the O(α s 2 ) estimation of the pion FF in the framework of the fractional analytic perturbation theory.

Explicit expressions for masses and bindings of multibaryons in two dimensional quantum chromodynamics

International Nuclear Information System (INIS)

Frishman, Y.; Zakrewski, W.J.

1989-07-01

We derive explicit expressions for the masses and the binding energies of k-baryons states in two dimensional (one space and one time) Quantum Chromodynamics (QCD(2)). The expressions are given using the parameters n 1 ,n 2 ,...,nN f -1 which characterize the representation of SU(N f ), where N f is the number of flavours, in terms of its Young tableau description. We find that the difference between the mass of the k-baryon state and the sum of masses of any combination of its constituents, is independent of the value N f (ie the number of flavors). These results hold within a certain bosonized form of QCD(2) and within the strong coupling limit of (G/m) → ∞, where G is the gauge coupling constant and m the quark mass. (authors)

Construction of two-dimensional quantum chromodynamics

Energy Technology Data Exchange (ETDEWEB)

Klimek, S.; Kondracki, W.

1987-12-01

We present a sketch of the construction of the functional measure for the SU(2) quantum chromodynamics with one generation of fermions in two-dimensional space-time. The method is based on a detailed analysis of Wilson loops.

Masses and decay constants of bound states containing fourth family quarks from QCD sum rules

International Nuclear Information System (INIS)

Bashiry, V.; Azizi, K.; Sultansoy, S.

2011-01-01

The heavy fourth generation of quarks that have sufficiently small mixing with the three known standard model families form hadrons. In the present work, we calculate the masses and decay constants of mesons containing either both quarks from the fourth generation or one from the fourth family and the other from known third family standard model quarks in the framework of the QCD sum rules. In the calculations, we take into account two-gluon condensate diagrams as nonperturbative contributions. The obtained results reduce to the known masses and decay constants of the bb and cc quarkonia when the fourth family quark is replaced by the bottom or charm quark.

ρ, ω, and φ meson-nucleon scattering lengths from QCD sum rules

International Nuclear Information System (INIS)

Koike, Y.

1995-01-01

The QCD sum rule method is applied to derive a formula for the ρ, ω, and φ meson-nucleon spin-isospin--averaged scattering lengths a ρ,ω,φ . We found that the crucial matrix elements are left-angle bar qγ μ D ν q right-angle N (q=ud) (twist-2 nucleon matrix element) for a ρ,ω and m s left-angle bar ss right-angle N for a φ , and obtained a ρ =0.14±0.07 fm, a ω =0.11±0.06 fm, and a φ =0.035±0.020 fm. These small numbers originate from a common factor 1/(m N +m ρ,ω,φ ). Our result suggests a slight increase (<60 MeV for ρ and ω, and <15 MeV for φ) of the effective mass of these vector mesons in nuclear matter (in the dilute nucleon-gas approximation). The origin of the discrepancy with Hatsuda-Lee was clarified

The magnetic moment of the Z_c(3900) as an axialvector tetraquark state with QCD sum rules

Science.gov (United States)

Wang, Zhi-Gang

2018-04-01

In this article, we assign the Z_c^± (3900) to be the diquark-antidiquark type axialvector tetraquark state, study its magnetic moment with the QCD sum rules in the external weak electromagnetic field by carrying out the operator product expansion up to the vacuum condensates of dimension 8. We pay special attention to matching the hadron side with the QCD side of the correlation function to obtain solid duality, the routine can be applied to study other electromagnetic properties of the exotic particles.

NNLO QCD analysis of CCFR data on xF3 structure function and Gross-Llewellyn-Smith sum rule with higher twist and nuclear corrections

International Nuclear Information System (INIS)

Sidorov, A.V.; Tokarev, M.V.

1997-01-01

A detailed NNLO QCD analysis of new CCFR data on xF 3 structure function including the target mass, higher twist and nuclear corrections was performed and parametrizations of the perturbative and power terms of the structure function were constructed. The results of QDC analysis of the structure function were used to study the Q 2 -dependence of the Gross-Llewellyn-Smith sum rule. The α s /π-expansion of S GLS (Q 2 ) was studied and parameters of the expansion were found to be s 1 =2.74±0.01, s 2 =-2.22±0.23, s 3 =-7.86±1.74 which are in good agreement with the perturbative QCD predictions for the Gross-Llewellyn-Smith sum rule in the next-to-leading and next-to-next-leading order

NNLO QCD analysis of CCFR data on xF3 structure function and Gross-Llewellyn Smith sum rule with higher twist and nuclear corrections

International Nuclear Information System (INIS)

Sidorov, A.V.; Tokarev, M.V.

1997-01-01

A detailed NNLO QCD analysis of new CCFR data on xF 3 structure function including the target mass, higher twist and nuclear corrections was performed and parametrizations of the perturbative and power terms of the structure function were constructed. The results of QCD analysis of the structure function were used to study the Q 2 -dependence of the Gross-Llewellyn Smith sum rule. The α S /π-expansion of S GLS (Q 2 ) was studied and parameters of the expansion were found to be s 1 =2.74±0.01, s 2 =-2.22±0.23, s 3 =-7.86±1.74 which are in good agreement with the perturbative QCD predictions for the Gross-Llewellyn Smith sum rule in the next-to-leading and next-to-next-to-leading order

Relativistic nuclear physics and quantum chromodynamics. Abstracts

International Nuclear Information System (INIS)

1994-01-01

The data of investigations on problems of high energy physics are given. Special attention pays to quantum chromodynamics at large distances, cumulative processes, multiquark states and relativistic nuclear collisions

Representation properties, Racah sum rule, and Biedenharn - Elliott identity for Uq(osp(1|2))

International Nuclear Information System (INIS)

Minnaert, P.; Mozrzymas, M.

1998-01-01

It is shown that the universal R matrix in the tensor product of two irreducible representation spaces of the quantum superalgebra U q (osp(1|2)) can be expressed by Clebsch - Gordan coefficients. The Racah sum rule satisfied by U q (osp(1|2)) Racah coefficients and 6-j symbols is derived from the properties of the universal R matrix in the tensor product of three representation spaces. Considering the tensor product of four irreducible representations, it is shown that Biedenharn - Elliott identity holds for U q (osp(1|2)) Racah coefficients and 6-j symbols. A recursion relation for U q (osp(1|2)) 6-j symbols is derived from the Biedenharn endash Elliott identity. copyright 1998 American Institute of Physics

The spin structure function g1p of the proton and a test of the Bjorken sum rule

Directory of Open Access Journals (Sweden)

C. Adolph

2016-02-01

Full Text Available New results for the double spin asymmetry A1p and the proton longitudinal spin structure function g1p are presented. They were obtained by the COMPASS Collaboration using polarised 200 GeV muons scattered off a longitudinally polarised NH3 target. The data were collected in 2011 and complement those recorded in 2007 at 160 GeV, in particular at lower values of x. They improve the statistical precision of g1p(x by about a factor of two in the region x≲0.02. A next-to-leading order QCD fit to the g1 world data is performed. It leads to a new determination of the quark spin contribution to the nucleon spin, ΔΣ, ranging from 0.26 to 0.36, and to a re-evaluation of the first moment of g1p. The uncertainty of ΔΣ is mostly due to the large uncertainty in the present determinations of the gluon helicity distribution. A new evaluation of the Bjorken sum rule based on the COMPASS results for the non-singlet structure function g1NS(x,Q2 yields as ratio of the axial and vector coupling constants |gA/gV|=1.22±0.05 (stat.±0.10 (syst., which validates the sum rule to an accuracy of about 9%.

Transition form factors of π0,η and η′ mesons: What can be learned from anomaly sum rule?

International Nuclear Information System (INIS)

Klopot, Yaroslav; Oganesian, Armen; Teryaev, Oleg

2013-01-01

We studied the applications of the anomaly sum rule (ASR) to the transition form factors of light pseudoscalar mesons: π 0 ,η and η ′ . This nonperturbative QCD approach can be used even if the QCD factorization is broken. The status of possible small non-OPE corrections to continuum in comparison to BaBar and Belle data is explored. The accuracy of the applied method and the role of the quark mass contributions are discussed

Perturbative quantum chromodynamics

CERN Document Server

1989-01-01

This book will be of great interest to advanced students and researchers in the area of high energy theoretical physics. Being the most complete and updated review volume on Perturbative QCD, it serves as an extremely useful textbook or reference book. Some of the reviews in this volume are the best that have been written on the subject anywhere. Contents: Factorization of Hard Processes in QCD (J C Collins, D E Soper & G Sterman); Exclusive Processes in Quantum Chromodynamics (S J Brodsky & G P Lepage); Coherence and Physics of QCD Jets (Yu L Dokshitzer, V A Khoze & S I Troyan); Pomeron in Qu

Baryons with chromodynamics

International Nuclear Information System (INIS)

Isgur, N.

1981-01-01

Many of the phenomenological difficulties of the non-relativistic quark model for baryons are overcome when some current prejudices from chromodynamics about quark forces are imposed. The effects of flavour independent confinement, symmetry breaking through quark masses, and colour hyperfine interactions are most prominent, leading to a satisfactory understanding of both the spectroscopy of low-lying baryons and of the signs and magnitudes of baryon couplings. The previously worrisome absence in partial wave analyses of a large number of the states expected in the nonrelativistic quark model is explained in terms of decouplings of the resonances from their elastic channels

Experimental status QCD

International Nuclear Information System (INIS)

Radyushkin, A.V.; Slepchenko, L.A.

1983-01-01

Analysis of experimental status of quantum chromodynamics (QCD) has been carried out. A short introduction into QCD is given. QCD sum rules are considered. Jets in e + e - annihilation and inclusive processes of lepton-hadron and hadron-hadron scattering are considered. Effect of QCD corrections to perturbation theory on quark count is analyzed

1S and $\\overline{MS}$ Bottom Quark Masses from $\\Upsilon$ Sum Rules

CERN Document Server

Hoang, A.H.

2000-01-01

The bottom quark $1S$ mass, $M_b^{1S}$, is determined using sum rules which relate the masses and the electronic decay widths of the $\\Upsilon$ mesons to moments of the vacuum polarization function. The $1S$ mass is defined as half the perturbative mass of a fictitious ${}^3S_1$ bottom-antibottom quark bound state, and is free of the ambiguity of order $\\Lambda_{QCD}$ which plagues the pole mass definition. Compared to an earlier analysis by the same author, which had been carried out in the pole mass scheme, the $1S$ mass scheme leads to a much better behaved perturbative series of the moments, smaller uncertainties in the mass extraction and to a reduced correlation of the mass and the strong coupling. We arrive at $M_b^{1S}=4.71\\pm 0.03$ GeV taking m_b(\\bar m_b)$ can be reduced if the three-loop corrections to the relation of pole and $\\bar{MS}$ mass are known and if the error in the strong coupling is decreased.

QCD sum-rules analysis of vector (1-) heavy quarkonium meson-hybrid mixing

Science.gov (United States)

Palameta, A.; Ho, J.; Harnett, D.; Steele, T. G.

2018-02-01

We use QCD Laplace sum rules to study meson-hybrid mixing in vector (1-) heavy quarkonium. We compute the QCD cross-correlator between a heavy meson current and a heavy hybrid current within the operator product expansion. In addition to leading-order perturbation theory, we include four- and six-dimensional gluon condensate contributions as well as a six-dimensional quark condensate contribution. We construct several single and multiresonance models that take known hadron masses as inputs. We investigate which resonances couple to both currents and so exhibit meson-hybrid mixing. Compared to single resonance models that include only the ground state, we find that models that also include excited states lead to significantly improved agreement between QCD and experiment. In the charmonium sector, we find that meson-hybrid mixing is consistent with a two-resonance model consisting of the J /ψ and a 4.3 GeV resonance. In the bottomonium sector, we find evidence for meson-hybrid mixing in the ϒ (1 S ) , ϒ (2 S ), ϒ (3 S ), and ϒ (4 S ).

The extended sum-rule model view of light and intermediate mass fragment emission in nuclear reactions at intermediate energies

International Nuclear Information System (INIS)

Brancus, I.M.; Rebel, H.; Wentz, J.; Corcalciuc, V.

1989-11-01

The original sum-rule model worked out by Wilczynski et al. and successfully used for a global description of complete and incomplete fusion reactions has been extended by a term accounting for dissipative processes of the dinuclear system on its way to fusion. When applying to light and heavy ion collisions with various targets at energies in the transitional region, the new term proves to be rather essential for reproducing the element distributions of the fragments emitted from rather asymmetric systems. (orig.) [de

New perspectives in quantum chromodynamics

International Nuclear Information System (INIS)

Brodsky, S.J.

1993-07-01

In these lectures I will discuss three central topics in quantum chromodynamics: (1) the use of light cone quantization and Fock space methods to determine the long and short-distance structure of quark and gluon distributions within hadrons; (2) the role of spin, heavy quarks, and nuclei in unraveling fundamental phenomenological features of QCD; and (3) a new approach to understanding the scale and scheme dependence of perturbative QCD predictions

Chiral-symmetry breakdown in large-N chromodynamics

International Nuclear Information System (INIS)

Coleman, S.; Witten, E.

1980-01-01

Chromodynamics with n flavors of massless quarks is invariant under chiral U(n) x U(n). It is shown that in the limit of a large number of colors, under reasonable assumptions, this symmetry group must spontaneously break down to diagonal U

Collective excitations of strongly coupled bilayer charged Bose liquids in the third-frequency-moment sum rule

International Nuclear Information System (INIS)

Tas, Murat; Tanatar, B.

2008-01-01

We calculate the collective excitation modes of strongly coupled bilayer charged Bose systems. We employ the dielectric matrix formulation to study the correlation effects within the random-phase approximation (RPA), the self consistent field approximation Singwi, Tosi, Land, and Sjoelander (STLS), and the quasilocalized charge approximation (QLCA), which satisfies the third-frequency-moment ( 3 >) sum rule. We find that the QLCA predicts a long-wavelength correlation-induced energy gap in the out-of-phase plasmon mode, similar to the situation in electronic bilayer systems. The energy gap and the plasmon density of states are studied as a function of interlayer separation and coupling parameter r s . The results should be helpful for experimental investigations

Research program in elementary particle theory: Progress report, January 1, 1987-December 1987

International Nuclear Information System (INIS)

Sudarshan, E.C.G.; Dicus, D.A.

1987-08-01

Progress is reported in the areas of: strings and gauge theories, mathematical physics and quantum optics, high energy physics phenomenology, quantum chromodynamic sum rules, and application of particle physics to astrophysics. Titles of DOE reports resulting from this research are listed, and the research histories of the scientific staff of the Center for Particle Theory are given

Higher-twist effects in the B → π transition form factor from QCD light-cone sum rules

Energy Technology Data Exchange (ETDEWEB)

Khodjamirian, Alexander; Rusov, Aleksey [Universitaet Siegen (Germany). Fakultaet IV, Department Physik, Theoretische Physik 1 Walter-Flex-Strasse 3 57068 Siegen

2016-07-01

I report on the progress in calculating new higher-twist corrections to the QCD light-cone sum rule for the B → π transition form factor. First, the expansion of the massive heavy-quark propagator in the external gluonic field near the light-cone was extended to include new terms containing the gluon-field strength derivatives. The resulting analytical expressions for the twist-5 and twist-6 contributions to the correlation function were obtained in a factorized approximation, expressed via the product of the quark-condensate density and the lower-twist pion distribution amplitudes. The numerical analysis of new higher-twist effects is in progress.

B-decay form factors from QCD sum rules

International Nuclear Information System (INIS)

Offen, Nils

2008-01-01

In the Standard Model of particle physics there is only one source of CP-violation. Namely, a single complex phase in the unitary 3 x 3 CKM-Matrix governing flavor transitions in the weak interaction. The unitarity is usually visualized by a triangle in the complex ρ - η-plane. Therefore testing this framework comes down to measuring weak decays, relating observables to sides and angles of this so called Unitarity Triangle(UT). Particular interest in this respect is payed to decays of mesons containing a heavy b-quark, giving the opportunity to alone determine all parameters of the UT. Doing this is far from easy. Besides tedious experimental measurements the theoretical calculations are plagued by hadronic quantities which cannot be determined by perturbation theory. In this work several of these quantities so called form factors are computed using the well known method of light cone sum rules(LCSR). Two different setups have been used. One, established in this work, utilizing a correlation function with an on-shell B-Meson and one following the traditional calculation by taking the light meson on-shell. Both using light cone expansion in the respective on-shell mesons distribution amplitudes. While the first approach allows to calculate a whole bunch of phenomenologically interesting quantities by just changing Dirac-structures of the relevant currents it has the drawback that it does not have access to the well developed twist expansion of the latter. To incorporate higher Fock-state contributions the first models for three-particle distribution amplitudes of the B-Meson have been derived. α s -corrections remain out of the scope of this work. Nevertheless does a comparison with more sophisticated methods show an encouraging numerical agreement. In the second setup all known corrections especially the never verified α s -corrections to Twist three terms have been recalculated and a competitive result for the CKM-matrixelement vertical stroke V ub vertical

Analyzing B{sub s} - anti B{sub s} mixing. Non-perturbative contributions to bag parameters from sum rules

Energy Technology Data Exchange (ETDEWEB)

Mannel, T. [Siegen Univ. (Germany). FB 7, Theoretische Physik; Pecjak, B.D. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Pivovarov, A.A. [Siegen Univ. (Germany). FB 7, Theoretische Physik]|[Russian Academy of Sciecnes, Moscow (Russian Federation). Inst. for Nuclear Research

2007-03-15

We use QCD sum rules to compute matrix elements of the {delta}B=2 operators appearing in the heavy-quark expansion of the width difference of the B{sub s} mass eigenstates. Our analysis includes the leading-order operators Q and Q{sub S}, as well as the subleading operators R{sub 2} and R{sub 3}, which appear at next-to-leading order in the 1/m{sub b} expansion. We conclude that the violation of the factorization approximation for these matrix elements due to non-perturbative vacuum condensates is as low as 1-2%. (orig.)

Analysis of J/psi → etasub(c)γ decay by the method of QCD sum rules

International Nuclear Information System (INIS)

Bejlin, V.A.; Radyushkin, A.V.

1984-01-01

The radiative M1 transitions in charmonium are analyzed by the method of QCD sum rules taking into account nonperturbative corrections O( ). The dependence of the result on the choice of the parameter is investigated. The account of the lower nonperturbative corrections to the amplitude, describing radiation M1-transitions in charmonium, changes slightly the result for the decay widths GITA(J/psi → etasub(c)γ). The calculations show that the values of parameter phi, somewhat larger than the standard, one, result in shifting the theoretical values for GITA(J/psi → etasub(c)γ) in the direction of the experimental one, however no unambiguous conclusion on phi deviation of the standard value can be drawn without account for the contribution from higher dimensions

Analysis of the strong decays Ds3*(2860) → DK, D*K with QCD sum rules

International Nuclear Information System (INIS)

Wang, Zhi-Gang

2016-01-01

In this article, we assign the D s3 * (2860) to be a D-wave c anti s meson, study the hadronic coupling constants G D s3 * (2860)DK and G D s3 * (2860)D * K with the three-point QCD sum rules, and calculate the partial decay widths Γ(D s3 * (2860) → D * K) and Γ(D s3 * (2860) → DK). The predicted ratio R = Γ(D s3 * (2860) → D * K)/Γ(D s3 * (2860) → DK) = 0.57±0.38 cannot reproduce the experimental value R = Br(D sJ * (2860) → D * K)/Br(D sJ * (2860) → DK) = 1.10±0.15±0.19. (orig.)

Quantum chromodynamics and deep inelastic e - N scattering at TRISTAN

International Nuclear Information System (INIS)

Muta, Taizo

1979-04-01

An introductory survey is given on the formulation of QCD in deep inelastic lepton-hadron scatterings. Typical predictions of QCD are presented in the kinematical region of TRISTAN, including detailed descriptions of the scaling violation, QCD correction to the current algebra sum rules, problem of quark masses and higher order effects. Some suggestions for experiments at TRISTAN are made. (author)

Heavy-to-light form factors: Sum rules on the light cone and beyond

International Nuclear Information System (INIS)

Lucha, Wolfgang; Melikhov, Dmitri; Simula, Silvano

2007-01-01

We report the first systematic analysis of the off-light-cone effects in sum rules for heavy-to-light form factors. These effects are investigated in a model based on scalar constituents, which allows a technically rather simple analysis but has the essential features of the analogous QCD calculation. The correlator relevant for the extraction of the heavy-to-light form factor is calculated in two different ways: first, by adopting the full Bethe-Salpeter amplitude of the light meson and, second, by performing the expansion of this amplitude near the light cone x 2 =0. We demonstrate that the contributions to the correlator from the light-cone term x 2 =0 and the off-light-cone terms x 2 ≠0 have the same order in the 1/m Q expansion. The light-cone correlator, corresponding to x 2 =0, is shown to systematically overestimate the full correlator, the difference being ∼Λ QCD /δ, with δ the continuum subtraction parameter of order 1 GeV. Numerically, this difference is found to be 10 divide 20%

Quantum chromodynamic quark model study of hadron and few hadron systems

International Nuclear Information System (INIS)

Ji, Chueng-Ryong.

1990-10-01

This report details research progress and results obtained during the five month period July 1, 1990 to November 30, 1990. The research project, entitled ''Quantum Chromodynamic Quark Model Study of Hadron and Few Hadron Systems,'' is supported by grant FG05-90ER40589 between North Carolina State University and the United States Department of Energy. This is a research program addressing theoretical investigations of hadron structure and reactions using quantum chromodynamic quark models. The new, significant research results are briefly summarized in the following sections

Revisit assignments of the new excited Ω{sub c} states with QCD sum rules

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhi-Gang; Wei, Xing-Ning; Yan, Ze-Hui [North China Electric Power University, Department of Physics, Baoding (China)

2017-12-15

In this article, we distinguish the contributions of the positive parity and negative parity Ω{sub c} states, study the masses and pole residues of the 1S, 1P, 2S and 2P Ω{sub c} states with the spin J = (1)/(2) and (3)/(2) using the QCD sum rules in a consistent way, and we revisit the assignments of the new narrow excited Ω{sub c}{sup 0} states. The predictions support assigning Ω{sub c}(3000) to the 1P Ω{sub c} state with J{sup P} = (1)/(2){sup -}, assigning Ω{sub c}(3090) to the 1P Ω{sub c} state with J{sup P} = (3)/(2){sup -} or the 2S Ω{sub c} state with J{sup P} = (1)/(2){sup +}, and assigning Ω{sub c}(3119) to the 2S Ω{sub c} state with J{sup P} = (3)/(2){sup +}. (orig.)

Analysis of the QQ anti Q anti Q tetraquark states with QCD sum rules

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhi-Gang [North China Electric Power University, Department of Physics, Baoding (China)

2017-07-15

In this article, we study the J{sup PC} = 0{sup ++} and 2{sup ++} QQ anti Q anti Q tetraquark states with the QCD sum rules, and we obtain the predictions M{sub X(cc} {sub anti} {sub c} {sub anti} {sub c,0}{sup {sub +}{sub +)}} =5.99 ± 0.08 GeV, M{sub X(cc} {sub anti} {sub c} {sub anti} {sub c,2}{sup {sub +}{sub +)}} = 6.09 ± 0.08 GeV, M{sub X(bb} {sub anti} {sub b} {sub anti} {sub b,0}{sup {sub +}{sub +)}} = 18.84 ± 0.09 GeV and M{sub X(bb} {sub anti} {sub b} {sub anti} {sub b,2}{sup {sub +}{sub +)}} = 18.85 ± 0.09 GeV, which can be confronted to the experimental data in the future. Furthermore, we illustrate that the diquark-antidiquark type tetraquark state can be taken as a special superposition of a series of meson-meson pairs and that it embodies the net effects. (orig.)

Rapporteur talks at Singapore (deep inelastic scattering) and at Hadron 90 (conference summary)

International Nuclear Information System (INIS)

Close, F.E.

1990-11-01

This talk begins by reviewing the early years of deep inelastic scattering with particular reference to some theoretical work. Current highlights include an agreed uniform set of structure functions, polarised structure functions, possible violations of the Gottfried sum rule, deep inelastic scattering off nuclei and anticipated breakdown of naive perturbative quantum chromodynamics QCD as x → 0 at HERA. (author)

Color-charge algebras in Adler's chromodynamics

International Nuclear Information System (INIS)

Cvitanovic, P.; Gonsalves, R.J.; Neville, D.E.

1978-01-01

We show that the color-charge algebra in the three-quark sector generated by the matrices of the fundamental representation of U(n) does not have the trace properties required in Adler's extension of chromodynamics. We also discuss a diagrammatic representation of algebras generated by quark and antiquark charges in general, and an embedding of the N-quark algebra in the symmetric group S/sub N/+1

Quantum chromodynamics and hadron jets

International Nuclear Information System (INIS)

Dokshitser, Y.L.; Dyakonov, D.I.

1979-07-01

These lectures are devoted to the description of the various properties of hard scattering processes with the participation of hadrons in the framework of Quantum Chromodynamics. We discuss in detail the validity and region of applicability of perturbation theory applied to hadron processes. Particular attention is paid to the question of the structure of quark and gluon jets produced in hard processes (as an example, e + e - annihilation into hadrons). In addition to giving a pedagogical review, we also present new results. (orig.)

Quantum Chromodynamic at finite temperature

International Nuclear Information System (INIS)

Magalhaes, N.S.

1987-01-01

A formal expression to the Gibbs free energy of topological defects of quantum chromodynamics (QCD)by using the semiclassical approach in the context of field theory at finite temperature and in the high temperature limit is determined. This expression is used to calculate the free energy of magnetic monopoles. Applying the obtained results to a method in which the free energy of topological defects of a theory may indicate its different phases, its searched for informations about phases of QCD. (author) [pt

The form factors of the process γ*γ*→π0 for small virtuality of one of the photons and QCD sum rules (1): the structure of the infrared singularities

International Nuclear Information System (INIS)

Radyushkin, A.V.; Ruskov, R.

1992-01-01

We extend the QCD sum rule analysis of the form factor F γ* γ *→π 0 (q 1 2 ,q 2 2 ) into the region of small virtuality of one of the photons, where one should perform more precisely an OPE to factorize large and small distance contributions. As a first step the form factor is investigated in the region of moderate virtualities and the full corrections in the sum rule are obtained. It is shown that the infrared mass singularities are subtracted in the corresponding OPE for essentially nonsymmetric kinematics due to the operators of lowest two twists. On a simple scalar example the most important steps of the further calculations are demonstrated. 26 refs.; 8 figs

Higher order corrections in perturbative quantum chromodynamics

Indian Academy of Sciences (India)

Since the discovery of asymptotic freedom in non-abelian gauge field theories, like quan- tum chromodynamics (QCD), many perturbative calculations have been performed to ..... The integral above appears in the partial integration with respect to the momentum. &½ of the expression below (see figure 2). ¼. Т&½. ґѕπµТ.

Underlying theory based on quaternions for Alder's algebraic chromodynamics

International Nuclear Information System (INIS)

Horwitz, L.P.; Biedenharn, L.C.

1981-01-01

It is shown that the complex-linear tensor product for quantum quaternionic Hilbert (module) spaces provides an algebraic structure for the non-local gauge field in Adler's algebraic chromodynamics for U

Transition form factors of π{sup 0},η and η{sup ′} mesons: What can be learned from anomaly sum rule?

Energy Technology Data Exchange (ETDEWEB)

Klopot, Yaroslav, E-mail: klopot@theor.jinr.ru [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Oganesian, Armen, E-mail: armen@itep.ru [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Institute of Theoretical and Experimental Physics, 117218 Moscow (Russian Federation); Teryaev, Oleg, E-mail: teryaev@theor.jinr.ru [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)

2013-12-15

We studied the applications of the anomaly sum rule (ASR) to the transition form factors of light pseudoscalar mesons: π{sup 0},η and η{sup ′}. This nonperturbative QCD approach can be used even if the QCD factorization is broken. The status of possible small non-OPE corrections to continuum in comparison to BaBar and Belle data is explored. The accuracy of the applied method and the role of the quark mass contributions are discussed.

Adler function, sum rules and Crewther relation of order O(αs4): The singlet case

International Nuclear Information System (INIS)

Baikov, P.A.; Chetyrkin, K.G.; Kühn, J.H.; Rittinger, J.

2012-01-01

The analytic result for the singlet part of the Adler function of the vector current in a general gauge theory is presented in five-loop approximation. Comparing this result with the corresponding singlet part of the Gross-Llewellyn Smith sum rule (Baikov et al., 2010 ), we successfully demonstrate the validity of the generalized Crewther relation for the singlet part. This provides a non-trivial test of both our calculations and the generalized Crewther relation. Combining the result with the already available non-singlet part of the Adler function (Baikov et al., 2008 , Baikov et al., 2010 ) we arrive at the complete O(α s 4 ) expression for the Adler function and, as a direct consequence, at the complete O(α s 4 ) correction to the e + e - annihilation into hadrons in a general gauge theory.

Analysis of the strong decays Ds3 *(2860) → DK, D*K with QCD sum rules

Science.gov (United States)

Wang, Zhi-Gang

2016-10-01

In this article, we assign the D_{s3}^{ast}(2860) to be a D-wave c bar{s} meson, study the hadronic coupling constants G_{D_{s3}^{ast}(2860)DK} and G_{D_{s3}^{ast} (2860)D^{ast}K} with the three-point QCD sum rules, and calculate the partial decay widths Γ (D_{s3}^{ast} (2860) → D^{ast}K) and Γ (D_{s3}^{ast}(2860) → DK) . The predicted ratio R = Γ (D_{s3}^{ast} (2860)→ D^{ast}K)/Γ (D_{s3}^{ast} (2860)→ DK) = 0.57± 0.38 cannot reproduce the experimental value R = Br(D_{sJ}^{ast} (2860)→ D^{ast}K)/Br (D_{sJ}^{ast} (2860)→ DK) = 1.10 ± 0.15 ± 0.19.

Renormalization group improved bottom mass from {Upsilon} sum rules at NNLL order

Energy Technology Data Exchange (ETDEWEB)

Hoang, Andre H.; Stahlhofen, Maximilian [Wien Univ. (Austria). Fakultaet fuer Physik; Ruiz-Femenia, Pedro [Wien Univ. (Austria). Fakultaet fuer Physik; Valencia Univ. - CSIC (Spain). IFIC

2012-09-15

We determine the bottom quark mass from non-relativistic large-n {Upsilon} sum rules with renormalization group improvement at next-to-next-to-leading logarithmic order. We compute the theoretical moments within the vNRQCD formalism and account for the summation of powers of the Coulomb singularities as well as of logarithmic terms proportional to powers of {alpha}{sub s} ln(n). The renormalization group improvement leads to a substantial stabilization of the theoretical moments compared to previous fixed-order analyses, which did not account for the systematic treatment of the logarithmic {alpha}{sub s} ln(n) terms, and allows for reliable single moment fits. For the current world average of the strong coupling ({alpha}{sub s}(M{sub Z})=0.1183{+-}0.0010) we obtain M{sub b}{sup 1S}=4.755{+-}0.057{sub pert} {+-}0.009{sub {alpha}{sub s}}{+-}0.003{sub exp} GeV for the bottom 1S mass and anti m{sub b}(anti m{sub b})=4.235{+-}0.055{sub pert}{+-}0.003{sub exp} GeV for the bottom MS mass, where we have quoted the perturbative error and the uncertainties from the strong coupling and the experimental data.

EM Transition Sum Rules Within the Framework of sdg Proton-Neutron Interacting Boson Model, Nuclear Pair Shell Model and Fermion Dynamical Symmetry Model

Science.gov (United States)

Zhao, Yumin

1997-07-01

By the techniques of the Wick theorem for coupled clusters, the no-energy-weighted electromagnetic sum-rule calculations are presented in the sdg neutron-proton interacting boson model, the nuclear pair shell model and the fermion-dynamical symmetry model. The project supported by Development Project Foundation of China, National Natural Science Foundation of China, Doctoral Education Fund of National Education Committee, Fundamental Research Fund of Southeast University

Hadron masses in quantum chromodynamics on the transverse lattice

International Nuclear Information System (INIS)

Bardeen, W.A.; Pearson, R.B.; Rabinovici, E.

1979-09-01

Calculational methods are formulated for the transverse lattice version of quantum chromodynamics. These methods are used to study the low lying spectrum of gluon bound states in the pure Yang-Mills theory. 15 references

Quantum chromodynamics effects in electroweak and Higgs physics

Indian Academy of Sciences (India)

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

Masses of light quarks in quantum chromodynamics

Energy Technology Data Exchange (ETDEWEB)

Hubschmid, W; Mallik, S [Bern Univ. (Switzerland). Inst. fuer Theoretische Physik

1982-12-28

We try to determine light quark masses by considering sum rules for the vacuum expectation value of the time-ordered correlation function of two divergences of the axial vector current. The evaluation is carried out at momenta high enough for the non-perturbative contributions to be negligible. We find that the average mass of the up and down quark at a momentum of 1 GeV lies between 3.3 and 7.9 MeV while that for the strange quark lies between 84 and 212 MeV. The ranges of values reflect predominantly the uncertainty in the absorptive part in the low energy region (approx. <= 1.7 GeV).

QCD sum rules study of the JPC=1-- charmonium Y mesons

International Nuclear Information System (INIS)

Albuquerque, R.M.; Nielsen, M.

2009-01-01

We use QCD sum rules to test the nature of the recently observed mesons Y(4260), Y(4350) and Y(4660), assumed to be exotic four-quark (cc-bar qq-bar) or (cc-bar ss-bar) states with J PC =1 -- . We work at leading order in α s , consider the contributions of higher dimension condensates and keep terms which are linear in the strange quark mass m s . We find for the (cc-bar ss-bar) state a mass m Y =(4.65±0.10) GeV which is compatible with the experimental candidate Y(4660), while for the (cc-bar qq-bar) state we find a mass m Y =(4.49±0.11) GeV, which is still consistent with the mass of the experimental candidate Y(4350). With the tetraquark structure we are working we cannot explain the Y(4260) as a tetraquark state. We also consider molecular D s0 D-bar s * and D 0 D-bar * states. For the D s0 D-bar s * molecular state we get m D s0 D -bar s* =(4.42±0.10) GeV which is consistent, considering the errors, with the mass of the meson Y(4350) and for the D 0 D-bar* molecular state we get m D 0 D -bar*=(4.27±0.10) GeV in excellent agreement with the mass of the meson Y(4260)

Developments in lattice quantum chromodynamics for matter at high ...

Indian Academy of Sciences (India)

2015-05-06

May 6, 2015 ... Lattice quantum chromodynamics; finite density; sign problem. PACS Nos 11.15. ... Lattice QCD relies on importance sampling assigning a real ..... conjectured that a single saddle point (e.g. the perturbative one) suffices [53].

Progress toward the effective Quantum Chromodynamic Lagrangian from symmetry considerations

International Nuclear Information System (INIS)

Salomone, A.N.

1982-01-01

The properties of an effective Lagrangian which satisfies both the axial and trace anomaly equations of Quantum Chromodynamics are investigated both from the theoretical and phenomenological points of view. The model Lagrangian requires that chiral symmetry be broken spontaneously. The non-linear approximation of the model illuminates eta-glue duality or mixing. The phase transition behavior of the model of Quantum Chromodynamics can be studied as the numbers of flavors and the vacuum angle are varied by analyzing a simple mechanical analog. The analog of the model is similar to the massive Schwinger model. The possibility of a physical scalar glue state is discussed and it is shown that it is characterized by a pronounced eta to two glue decay width. A nonperturbative Quantum Chromodynamic vacuum is seen to follow directly from satisfying the trace anomaly. The quark matter meson, eta, is at least as prominent as the glueball, iota, in the gluon dominated reaction psi to gamma plus anything. An associated large breaking of flavor SU(3) is shown to be ameliorated as the model is made more realistic by lowering scalar meson masses from infinity. The pi delta decay of the iota (1440) can be reasonably well estimated without the need of introducing any new parameters

Lattice quantum chromodynamics equation of state: A better ...

Indian Academy of Sciences (India)

Lattice gauge theory; quantum chromodynamics; finite temperature field theory. ... to a previously underappreciated feature of the plasma phase – that it is far from being a ... setting P = 0 just below Tc and the numerical integration errors. ...... for different temperatures, both above and below Tc. We draw attention to the.

U matrix construction for Quantum Chromodynamics through Dirac brackets

International Nuclear Information System (INIS)

Santos, M.A. dos.

1987-09-01

A procedure for obtaining the U matrix using Dirac brackets, recently developed by Kiefer and Rothe, is applied for Quantum Chromodynamics. The correspondent interaction Lagrangian is the same obtained by Schwinger, Christ and Lee, using independent methods. (L.C.J.A.)

Synthesis of quantum chromodynamics and nuclear physics

International Nuclear Information System (INIS)

Brodsky, S.J.; Lepage, G.P.

1980-08-01

The asymptotic freedom behavior of quantum chromodynamics allows the rigorous calculation of hadronic and nuclear amplitudes at short distances by perturbative methods. The implications of QCD for large-momentum-transfer nuclear form factors and scattering processes, as well as for the structure of nuclear wave functions and nuclear interactions at short distances, are discussed. The necessity for color-polarized internal nuclear states is also discussed. 6 figures

QCD sum rules of the Laplace transform type for the gluon component of the U(1)sub(A) meson mass

International Nuclear Information System (INIS)

Narison, S.

1981-07-01

We get upper bound of the gluon component of the U(1)sub(A) meson mass using QCD sum rules of the Laplace transform type to the two-point functions associated to the divergence of the U(1)sub(A) current in the chiral limit. For Λ is approximately equal to 70 is approximately 210 MeV and fsub(eta') is approximately equal to (0.5 is approximately 0.7) sqrt 3 fsub(π), we obtain Msub(G) is approximately smaller to (0.6 is approximately 0.85) GeV, which indicates an important gluon contribution to the eta' mass. (author)

Multi-Higgs doublet models: physical parametrization, sum rules and unitarity bounds

Science.gov (United States)

Bento, Miguel P.; Haber, Howard E.; Romão, J. C.; Silva, João P.

2017-11-01

If the scalar sector of the Standard Model is non-minimal, one might expect multiple generations of the hypercharge-1/2 scalar doublet analogous to the generational structure of the fermions. In this work, we examine the structure of a Higgs sector consisting of N Higgs doublets (where N ≥ 2). It is particularly convenient to work in the so-called charged Higgs basis, in which the neutral Higgs vacuum expectation value resides entirely in the first Higgs doublet, and the charged components of remaining N - 1 Higgs doublets are mass-eigenstate fields. We elucidate the interactions of the gauge bosons with the physical Higgs scalars and the Goldstone bosons and show that they are determined by an N × 2 N matrix. This matrix depends on ( N - 1)(2 N - 1) real parameters that are associated with the mixing of the neutral Higgs fields in the charged Higgs basis. Among these parameters, N - 1 are unphysical (and can be removed by rephasing the physical charged Higgs fields), and the remaining 2( N - 1)2 parameters are physical. We also demonstrate a particularly simple form for the cubic interaction and some of the quartic interactions of the Goldstone bosons with the physical Higgs scalars. These results are applied in the derivation of Higgs coupling sum rules and tree-level unitarity bounds that restrict the size of the quartic scalar couplings. In particular, new applications to three Higgs doublet models with an order-4 CP symmetry and with a Z_3 symmetry, respectively, are presented.

Predictions of quantum chromodynamics of the second order

International Nuclear Information System (INIS)

Kounnas, M.C.

1981-12-01

The model of partons is generalized. Proof of factorization in the region of the large moments of transfer, higher-order corrections in a scalar theory, in non-abelian gauge theories, for single transitions, higher-order effects for structure and fragmentation functions in quantum chromodynamics, analytical solution in the space of the X's are presented [fr

Photon pairs: Quantum chromodynamics continuum and the Higgs ...

Indian Academy of Sciences (India)

is the largest. Results are compared with data from the Fermilab Tevatron and predictions are made for the large hadron collider. The QCD continuum is shown to have a softer spectrum than the Higgs boson signal at the LHC. Keywords. Higgs; photon pairs; quantum chromodynamics. PACS Nos 12.15.Ji; 12.38.Cy; 13.85.

Adler function and Bjorken polarized sum rule: Perturbation expansions in powers of the S U (Nc) conformal anomaly and studies of the conformal symmetry limit

Science.gov (United States)

Cvetič, Gorazd; Kataev, A. L.

2016-07-01

We consider a new form of analytical perturbation theory expansion in the massless S U (Nc) theory, for the nonsinglet part of the e+e--annihilation to hadrons Adler function Dn s and of the Bjorken sum rule of the polarized lepton-hadron deep-inelastic scattering Cns B j p, and demonstrate its validity at the O (αs4)-level at least. It is a two-fold series in powers of the conformal anomaly and of S U (Nc) coupling αs. Explicit expressions are obtained for the {β }-expanded perturbation coefficients at O (αs4) level in MS ¯ scheme, for both considered physical quantities. Comparisons of the terms in the {β }-expanded coefficients are made with the corresponding terms obtained by using extra gluino degrees of freedom, or skeleton-motivated expansion, or Rδ-scheme motivated expansion in the Principle of Maximal Conformality. Relations between terms of the {β }-expansion for the Dn s- and Cns B j p-functions, which follow from the conformal symmetry limit and its violation, are presented. The relevance to the possible new analyses of the experimental data for the Adler function and Bjorken sum rule is discussed.

Quantum Chromodynamics and Nuclear Physics at Extreme Energy Density

Energy Technology Data Exchange (ETDEWEB)

Mueller, B.; Bass, S.A.; Chandrasekharan, S.; Mehen, T.; Springer, R.P.

2005-11-07

The report describes research in theoretical quantum chromodynamics, including effective field theories of hadronic interactions, properties of strongly interacting matter at extreme energy density, phenomenology of relativistic heavy ion collisions, and algorithms and numerical simulations of lattice gauge theory and other many-body systems.

Quantum Chromodynamics and Nuclear Physics at Extreme Energy Density

International Nuclear Information System (INIS)

Mueller, B.; Bass, S.A.; Chandrasekharan, S.; Mehen, T.; Springer, R.P.

2005-01-01

The report describes research in theoretical quantum chromodynamics, including effective field theories of hadronic interactions, properties of strongly interacting matter at extreme energy density, phenomenology of relativistic heavy ion collisions, and algorithms and numerical simulations of lattice gauge theory and other many-body systems.

Form factors and charge radii in a quantum chromodynamics ...

Indian Academy of Sciences (India)

tic form factors and charge radii of D, Ds,B,Bs and Bc mesons in a quantum chromodynamics. (QCD)-inspired ... as pointed out in [12,13], one can expect a similar success here too. .... 0 were large and the formalism failed to account for large ...

The reorientation precession technique, REPREC, and the quadrupole moments of /sup 108/ /sup 110/Pd. [Sum rules

Energy Technology Data Exchange (ETDEWEB)

Hasselgren, L; Fahlander, C; Edvardson, L O; Thun, J E; Falk, F; Ghumman, B S

1975-04-01

The orientation precession technique, REPREC, for measurements of quadrupole moments is described. The application of REPREC to the measurement of the static electric quadrupole moments of the first excited 2/sup +/-states in /sup 108/ /sup 110/Pd is presented. The possibility to measure the matrix product P/sub 4/ = M/sub 02/M/sub 22/,M/sub 02/M/sub 22/ is also discussed. Such measurements are presented for /sup 108/ /sup 110/Pd. The results of these measurements are P/sub 4/O for both /sup 108/Pd and /sup 110/Pd. For /sup 108/Pd the quadrupole moment of the first excited 2/sup +/-state was found to be -.66 +- .18 eb and for /sup 110/Pd -.72 +- .14 eb. Intrinsic nuclear properties for /sup 106 -110/Pd are derived using the sum rules suggested by Kumar.

0+ tetraquark states from improved QCD sum rules: delving into X(5568)

Science.gov (United States)

Zhang, Jian-Rong; Zou, Jing-Lan; Wu, Jin-Yun

2018-04-01

In order to investigate the possibility of the recently observed X(5568) being a 0+ tetraquark state, we make an improvement to the study of the related various configuration states in the framework of the QCD sum rules. Particularly, to ensure the quality of the analysis, condensates up to dimension 12 are included to inspect the convergence of operator product expansion (OPE) and improve the final results of the studied states. We note that some condensate contributions could play an important role on the OPE side. By releasing the rigid OPE convergence criterion, we arrive at the numerical value {5.57}-0.23+0.35 {{GeV}} for the scalar-scalar diquark-antidiquark 0+ state, which agrees with the experimental data for the X(5568) and could support its interpretation in terms of a 0+ tetraquark state with the scalar-scalar configuration. The corresponding result for the axial-axial current is calculated to be {5.77}-0.33+0.44 {{GeV}}, which is still consistent with the mass of X(5568) in view of the uncertainty. The feasibility of X(5568) being a tetraquark state with the axial-axial configuration therefore cannot be definitely excluded. For the pseudoscalar-pseudoscalar and the vector-vector cases, their unsatisfactory OPE convergence make it difficult to find reasonable work windows to extract the hadronic information. Supported by National Natural Science Foundation of China (11475258, 11105223, 11675263) and the Project in NUDT for Excellent Youth Talents

Testing quantum chromodynamics in anti-proton reactions

International Nuclear Information System (INIS)

Brodsky, S.J.

1987-10-01

An experimental program with anti-protons at intermediate energy can serve as an important testing ground for QCD. Detailed predictions for exclusive cross sections at large momentum transfer based on perturbative QCD and the QCD sum rule form of the proton distribution amplitude are available for anti p p → γγ for both real and virtual photons. Meson-pair and lepton-pair final states also give sensitive tests of the theory. The production of charmed hadrons in exclusive anti p p channels may have a non-negligible cross section. Anti-proton interactions in a nucleus, particularly J/psi production, can play an important role in clarifying fundamental QCD issues, such as color transparency, critical length phenomena, and the validity of the reduced nuclear amplitude phenomenology

Quantum chromodynamics, chiral symmetry and bag models

International Nuclear Information System (INIS)

Soyeur, M.

1983-08-01

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

On one approximation in quantum chromodynamics

International Nuclear Information System (INIS)

Alekseev, A.I.; Bajkov, V.A.; Boos, Eh.Eh.

1982-01-01

Form of a complete fermion propagator near the mass shell is investigated. Considered is a nodel of quantum chromodynamics (MQC) where in the fermion section the Block-Nordsic approximation has been made, i. e. u-numbers are substituted for ν matrices. The model was investigated by means of the Schwinger-Dyson equation for a quark propagator in the infrared region. The Schwinger-Dyson equation was managed to reduce to a differential equation which is easily solved. At that, the Green function is suitable to represent as integral transformation

Jet invariant mass in quantum chromodynamics

International Nuclear Information System (INIS)

Clavelli, L.

1979-03-01

We give heuristic argument that a new class of observable related to the invariant mass of jets in e + e - annihilation is infrared finite to all orders of perturbation theory in Quantum Chromodynamics. We calculate the lowest order QCD predictions for the mass distribution as well as for the double differential cross section to produce back to back jets of invariant mass M 1 and M 2 . The resulting cross sections are quite different from that expected in simple hadronic fireball models and should provide experimentally accessible tests of QCD. (orig.) [de

Quantum chromodynamics as dynamics of loops

International Nuclear Information System (INIS)

Makeenko, Yu.; Migdal, A.A.

1980-01-01

The problem of a possibility of reformulating quantum chromodynamics (QCD) in terms of colourless composite fields instead of coloured quarks and gluons is considered. The role of such fields is played by the gauge invariant loop functionals. The Shwinger equations of motion is derived in the loop space which completely describe dynamics of the loop fields. New manifestly gauge invariant diagram technique in the loop space is developed. These diagrams reproduce asymptotic freedom in the ultraviolet range and are consistent with the confinement law in the infrared range

Some views about chromodynamics

International Nuclear Information System (INIS)

Pilon, E.

1995-01-01

The first lesson recalls some basis of quantum chromodynamics (QCD). Particularly the Lagrangian density and the Feynman laws are described. The second lesson presents the problem of renormalization and the notion of efficient coupling. The important property of asymptotic freedom of QCD is detailed. The third lesson gives a schematic classification of processes involved in hadronic physics with high energy-momentum transfer. Scale invariance and its breakdown by using leading log method is presented and leads to the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi equations. The fourth and last lesson paves the way to use the factorization method beyond the leading logs in the case of hadron-hadron collision within the frame of leading twist. Some ideas about comparisons between semi-analytical calculations and Monte-Carlo simulations are given. (A.C.)

The asymptotic 3-loop heavy flavor corrections to the charged current structure functions F{sup W{sup +-W{sup -}{sub L}}}(x,Q{sup 2}) and F{sup W{sup +-W{sup -}{sub 2}}}(x,Q{sup 2})

Energy Technology Data Exchange (ETDEWEB)

Behring, A.; Bluemlein, J.; Falcioni, G.; Freitas, A. de [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Manteuffel, A. von [Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy; Mainz Univ. (Germany). PRISMA Cluster of Excellence; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation

2016-09-15

We calculate the massive Wilson coefficients for the heavy flavor contributions to the non-singlet charged current deep-inelastic scattering structure functions F{sup W{sup +}{sub L}}(x,Q{sup 2})-F{sup W{sup -}{sub L}}(x,Q{sup 2}) and F{sup W{sup +}{sub 2}}(x,Q{sup 2}) - F{sup W{sup -}{sub 2}}(x,Q{sup 2}) in the asymptotic region Q{sup 2}>>m{sup 2} to 3-loop order in Quantum Chromodynamics (QCD) at general values of the Mellin variable N and the momentum fraction x. Besides the heavy quark pair production, also the single heavy flavor excitation s→c contributes. Numerical results are presented for the charm quark contributions and consequences on the unpolarized Bjorken sum rule and Adler sum rule are discussed.

Analysis of the strong coupling form factors of ΣbNB and ΣcND in QCD sum rules

Science.gov (United States)

Yu, Guo-Liang; Wang, Zhi-Gang; Li, Zhen-Yu

2017-08-01

In this article, we study the strong interaction of the vertices Σ b NB and Σ c ND using the three-point QCD sum rules under two different Dirac structures. Considering the contributions of the vacuum condensates up to dimension 5 in the operation product expansion, the form factors of these vertices are calculated. Then, we fit the form factors into analytical functions and extrapolate them into time-like regions, which gives the coupling constants. Our analysis indicates that the coupling constants for these two vertices are G ΣbNB = 0.43±0.01 GeV-1 and G ΣcND = 3.76±0.05 GeV-1. Supported by Fundamental Research Funds for the Central Universities (2016MS133)

Analysis of the strong decay X(5568) → B{sub s}{sup 0}π{sup +} with QCD sum rules

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhi-Gang [North China Electric Power University, Department of Physics, Baoding (China)

2016-05-15

In this article, we take the X(5568) to be the scalar diquark-antidiquark type tetraquark state, study the hadronic coupling constant g{sub XB{sub sπ}} with the three-point QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension-6 and including both the connected and the disconnected Feynman diagrams; then we calculate the partial decay width of the strong decay X(5568) → B{sub s}{sup 0}π{sup +} and obtain the value Γ{sub X} = (20.5 ± 8.1) MeV, which is consistent with the experimental data Γ{sub X} = (21.9 ± 6.4{sup +5.0}{sub -2.5}) MeV from the D0 collaboration. (orig.)

Oscillating Finite Sums

KAUST Repository

Alabdulmohsin, Ibrahim M.

2018-01-01

In this chapter, we use the theory of summability of divergent series, presented earlier in Chap. 4, to derive the analogs of the Euler-Maclaurin summation formula for oscillating sums. These formulas will, in turn, be used to perform many remarkable deeds with ease. For instance, they can be used to derive analytic expressions for summable divergent series, obtain asymptotic expressions of oscillating series, and even accelerate the convergence of series by several orders of magnitude. Moreover, we will prove the notable fact that, as far as the foundational rules of summability calculus are concerned, summable divergent series behave exactly as if they were convergent.

Oscillating Finite Sums

KAUST Repository

Alabdulmohsin, Ibrahim M.

2018-03-07

In this chapter, we use the theory of summability of divergent series, presented earlier in Chap. 4, to derive the analogs of the Euler-Maclaurin summation formula for oscillating sums. These formulas will, in turn, be used to perform many remarkable deeds with ease. For instance, they can be used to derive analytic expressions for summable divergent series, obtain asymptotic expressions of oscillating series, and even accelerate the convergence of series by several orders of magnitude. Moreover, we will prove the notable fact that, as far as the foundational rules of summability calculus are concerned, summable divergent series behave exactly as if they were convergent.

Some observations on quantum chromodynamics

International Nuclear Information System (INIS)

t Hooft, G.

1977-01-01

In this treatment of quantum chromodynamics it is argued that the formal series in the coupling constant g diverges badly for all values of g. Due to the renormalization group the series has a direct physical interpretation as an asymptotic expansion for very large (Euclidean) momenta. Although the expansion diverges, the question is whether in combination with physical requirements such as unitarity and causality it does nontheless define a theory uniquely and whether in principle the divergent series can be replaced by a convergent one, no matter how complicated. After a definition of the theory, the complex coupling constant plane for the massless theory and the Borel summation are considered. 14 references

Novel features of nuclear chromodynamics

Energy Technology Data Exchange (ETDEWEB)

Brodsky, Stanley J. [Stanford University, SLAC National Accelerator Laboratory, Stanford, CA (United States)

2017-03-15

I review a number of QCD topics where the nuclear environment provides new insights into fundamental aspects of the strong interactions. The topics include novel perspectives for nuclear physics, such as the hidden color of nuclear form factors, the relation of the nuclear force at short distances to quark interchange interactions, the effects of ''color transparency'' on the baryon-to-meson anomaly in hard heavy-ion collisions, flavor-dependent antishadowing, novel exotic multiquark states, the anomalous nuclear dependence of quarkonium hadroproduction, flavor-dependent antishadowing, and the breakdown of sum rules for nuclear structure functions. I also briefly discuss the insights into hadron physics and color confinement that one obtains from light-front holography, including supersymmetric features of the hadron spectrum. I also note that the virtual Compton amplitude on a proton (or nucleus) can be measured for two spacelike photons q{sup 2}{sub 1}, q{sup 2}{sub 2} < 0 using positronium-proton scattering [e{sup +}e{sup -}]p → e{sup +}e{sup -}p{sup '}. (orig.)

Murray Gell-Mann, the Eightfold Way, Quarks, and Quantum Chromodynamics

Science.gov (United States)

. Professor Gell-Mann's "eightfold way" theory brought order to the chaos created by the discovery , Professor Gell-Mann received the Nobel Prize in physics for his work on the theory of elementary particles later constructed the quantum field theory of quarks and gluons, called "quantum chromodynamics

Determination of the Bjorken Sum and Strong Coupling from Polarized Structure Functions

CERN Document Server

Altarelli, Guido; Forte, Stefano; Ridolfi, G; Altarelli, Guido; Ball, Richard D.; Forte, Stefano; Ridolfi, Giovanni

1997-01-01

We present a NLO perturbative analysis of all available data on the polarized structure function g_1(x,Q^2) with the aim of making a quantitative test of the validity of the Bjorken sum rule, of measuring \\alpha_s, and of deriving helicity fractions. We take particular care over the small x extrapolation, since it is now known that Regge behaviour is unreliable at perturbative scales. For fixed \\alpha_s we find that if all the most recent data are included g_A=1.18\\pm0.09, confirming the Bjorken sum rule at the 8% level. We further show that the value of \\alpha_s is now reasonably well constrained by scaling violations in the structure function data, despite the fact that it cannot yet be reliably fixed by the value of the Bjorken sum: our final result is \\alpha_s(m_Z) = 0.120+0.010-0.008. We also confirm earlier indications of a sizeable positive gluon polarization in the nucleon.

Self-consistence equations for extended Feynman rules in quantum chromodynamics

International Nuclear Information System (INIS)

Wielenberg, A.

2005-01-01

In this thesis improved solutions for Green's functions are obtained. First the for this thesis essential techniques and concepts of QCD as euclidean field theory are presented. After a discussion of the foundations of the extended approach for the Feynman rules of QCD with a systematic approach for the 4-gluon vertex a modified renormalization scheme for the extended approach is developed. Thereafter the resummation of the Dyson-Schwinger equations (DSE) by the appropriately modified Bethe-Salpeter equation is discussed. Then the leading divergences for the 1-loop graphs of the resummed DSE are determined. Thereafter the equation-of-motion condensate is defined as result of an operator-product expansion. Then the self-consistency equations for the extended approaches are defined and numerically solved. (HSI)

Sum rules across the unpolarized Compton processes involving generalized polarizabilities and moments of nucleon structure functions

Science.gov (United States)

Lensky, Vadim; Hagelstein, Franziska; Pascalutsa, Vladimir; Vanderhaeghen, Marc

2018-04-01

We derive two new sum rules for the unpolarized doubly virtual Compton scattering process on a nucleon, which establish novel low-Q2 relations involving the nucleon's generalized polarizabilities and moments of the nucleon's unpolarized structure functions F1(x ,Q2) and F2(x ,Q2). These relations facilitate the determination of some structure constants which can only be accessed in off-forward doubly virtual Compton scattering, not experimentally accessible at present. We perform an empirical determination for the proton and compare our results with a next-to-leading-order chiral perturbation theory prediction. We also show how these relations may be useful for a model-independent determination of the low-Q2 subtraction function in the Compton amplitude, which enters the two-photon-exchange contribution to the Lamb shift of (muonic) hydrogen. An explicit calculation of the Δ (1232 )-resonance contribution to the muonic-hydrogen 2 P -2 S Lamb shift yields -1 ±1 μ eV , confirming the previously conjectured smallness of this effect.

Precision calculation of threshold πd scattering, πN scattering lengths, and the GMO sum rule

Science.gov (United States)

Baru, V.; Hanhart, C.; Hoferichter, M.; Kubis, B.; Nogga, A.; Phillips, D. R.

2011-12-01

We use chiral perturbation theory (ChPT) to calculate the πd scattering length with an accuracy of a few percent, including isospin-violating corrections in both the two- and three-body sectors. In particular, we provide the technical details of a recent letter (Baru et al., 2011) [1], where we used data on pionic deuterium and pionic hydrogen atoms to extract the isoscalar and isovector pion-nucleon scattering lengths a and a. We study isospin-breaking contributions to the three-body part of a due to mass differences, isospin violation in the πN scattering lengths, and virtual photons. This last class of effects is ostensibly infrared enhanced due to the smallness of the deuteron binding energy. However, we show that the leading virtual-photon effects that might undergo such enhancement cancel, and hence the standard ChPT counting provides a reliable estimate of isospin violation in a due to virtual photons. Finally, we discuss the validity of the Goldberger-Miyazawa-Oehme sum rule in the presence of isospin violation, and use it to determine the charged-pion-nucleon coupling constant.

Measurement of xF3, F2 structure functions and Gross-Llewellyn Smith sum rule with IHEP-JINR neutrino detector

International Nuclear Information System (INIS)

Barabash, L.S.; Baranov, S.A.; Batusov, Yu.A.

1996-01-01

The isoscalar structure functions xF 3 and F 2 are measured as functions of x averaged over all Q 2 permissible for the range 6 to 28 GeV of incident (anti)neutrino energy. With the measured values of xF 3 , the value of the Gross-Llewellyn Smith sum rule is found to be ∫ 0 1 F 3 dx=2.13±0.38 (stat)±0.26 (syst). The QCD analysis of xF 3 provides Λ b ar M b ar S bar =358±59 MeV. The obtained value of the strong interaction constant α S (M Z )=0.120 -4 +3 is larger than most of the deep inelastic scattering results. 37 refs., 1 figs., 3 tabs

Nested (inverse) binomial sums and new iterated integrals for massive Feynman diagrams

International Nuclear Information System (INIS)

Ablinger, Jakob; Schneider, Carsten; Bluemlein, Johannes; Raab, Clemens G.

2014-07-01

Nested sums containing binomial coefficients occur in the computation of massive operatormatrix elements. Their associated iterated integrals lead to alphabets including radicals, for which we determined a suitable basis. We discuss algorithms for converting between sum and integral representations, mainly relying on the Mellin transform. To aid the conversion we worked out dedicated rewrite rules, based on which also some general patterns emerging in the process can be obtained.

Nested (inverse) binomial sums and new iterated integrals for massive Feynman diagrams

Energy Technology Data Exchange (ETDEWEB)

Ablinger, Jakob; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Bluemlein, Johannes; Raab, Clemens G. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2014-07-15

Nested sums containing binomial coefficients occur in the computation of massive operatormatrix elements. Their associated iterated integrals lead to alphabets including radicals, for which we determined a suitable basis. We discuss algorithms for converting between sum and integral representations, mainly relying on the Mellin transform. To aid the conversion we worked out dedicated rewrite rules, based on which also some general patterns emerging in the process can be obtained.

Elements of quantum chromodynamics

International Nuclear Information System (INIS)

Bjorken, J.D.

1979-01-01

The subject of quantum chromodynamics is discussed at length. The introduction motivates the exposition and points out the analogies between QCD and QED. Then, after some assumptions about the nature of QCD, a description is given of what the solution of the theory should look like for three stages of complexity: pure QCD with no fermions or other sources, introduction of superheavy quarks, introduction of the light quarks (u, d, s) with vacuum polarization and pair creation. Next, canonical quantization of QCD by use of a Hamiltonian formulation (in A 0 = 0 gauge) is considered; gauge ambiguities, theta vacua, instantons, etc., are encountered. Then the properties of the three stages noted above are discussed in much greater detail. These follow descriptions of the confinement problem and various approaches to it, as well as of more radical alternatives to QCD, such as the string model or the Pati-Salam program. Included in the summary is an assessment of the current situation. 101 references, 23 figures, 2 tables

Exclusive processes and the exclusive-inclusive connection in quantum chromodynamics

International Nuclear Information System (INIS)

Brodsky, S.J.; Lepage, G.P.

1979-03-01

An outline of a new analysis of exclusive processes and quantum chromodynamics is presented. The main elements of this work involve a consistent Fock space decomposition of the hadronic wave function, plus evolution equations for wave functions which allow an exact evaluation of hadronic matrix elements in the asymptotic short distance limit. 77 references

Large-Nc quantum chromodynamics and harmonic sums

Indian Academy of Sciences (India)

2012-06-08

Jun 8, 2012 ... This has led us to consider a class of analytic number theory .... The self-energy function LR(Q2) in the chiral limit vanishes order by order in QCD ... the 1/Nc expansion, the Goldstone loop corrections are subleading and, ...

Clothed Particles in Quantum Electrodynamics and Quantum Chromodynamics

Directory of Open Access Journals (Sweden)

Shebeko Alexander

2016-01-01

Full Text Available The notion of clothing in quantum field theory (QFT, put forward by Greenberg and Schweber and developed by M. Shirokov, is applied in quantum electrodynamics (QED and quantum chromodynamics (QCD. Along the guideline we have derived a novel analytic expression for the QED Hamiltonian in the clothed particle representation (CPR. In addition, we are trying to realize this notion in QCD (to be definite for the gauge group SU(3 when drawing parallels between QCD and QED.

Summing logs: the saga continues...

International Nuclear Information System (INIS)

Ellis, S.D.

1982-01-01

The structure of perturbative Quantum Chromodynamics in kinematic regimes characterized by two large but very different mass scales is discussed. The status of the sequence of approximations employed to theoretically study these regimes is reviewed along with some discussion of the present phenomenology. Various important outstanding questions are noted. 22 references

Local gauge symmetry and confinement in quantum chromodynamics

International Nuclear Information System (INIS)

Bardeen, W.A.; Pearson, R.B.

1977-01-01

The nonabelian color gauge theory of quarks and gluons has been proposed as the basis for fundamental theory of hadrons. The features of this theory (quantum chromodynamics) are considered which lead to confinement. A transverse lattice formulation of the theory is also discussed, which is used as a basis for calculation of properties of the hadron bound states. The theory is quantized by eliminating the longitudinal degrees of freedom in favour of coulomb potential. Hadrons are formed as bound states of quarks and the symmetric phase gluons

Which Basic Rules Underlie Social Judgments? Agency Follows a Zero-Sum Principle and Communion Follows a Non-Zero-Sum Principle.

Science.gov (United States)

Dufner, Michael; Leising, Daniel; Gebauer, Jochen E

2016-05-01

How are people who generally see others positively evaluated themselves? We propose that the answer to this question crucially hinges on the content domain: We hypothesize that Agency follows a "zero-sum principle" and therefore people who see others ashighin Agency are perceived aslowin Agency themselves. In contrast, we hypothesize that Communion follows a "non-zero-sum principle" and therefore people who see others ashighin Communion are perceived ashighin Communion themselves. We tested these hypotheses in a round-robin and a half-block study. Perceiving others as agentic was indeed linked to being perceived as low in Agency. To the contrary, perceiving others as communal was linked to being perceived as high in Communion, but only when people directly interacted with each other. These results help to clarify the nature of Agency and Communion and offer explanations for divergent findings in the literature. © 2016 by the Society for Personality and Social Psychology, Inc.

Quantum electrical and chromodynamics treated through Thompson's approach

International Nuclear Information System (INIS)

Nassif, Claudio; Silva, P.R.

2006-09-01

In this work we apply Thompson's method (of the dimensions and scales) to study some features of the Quantum Electro and Chromodynamics. This heuristic method can be considered as a simple and alternative way to the Renormalisation Group (R.G.) approach and when applied to QED-Lagrangian is able to obtain in a first approximation both the running coupling constant behavior of α(μ) and the mass m(μ). The calculations are evaluated just at d c = 4, where d c is the upper critical dimension of the problem, so that we obtain the logarithmic behavior both for the coupling α and the excess of mass Δm on the energy scale μ. Although our results are well-known in the vast literature of field theories, the advantage of Thompson's method, beyond its simplicity is that it is able to extract directly from QED-Lagrangian the physical (finite) behavior of α(μ) and m(μ), bypassing hard problems of divergences which normally appear in the conventional renormalisation schemes applied to field theories like QED. Quantum Chromodynamics (QCD) is also treated by the present method in order to obtain the quark condensate value. Besides this, the method is also able to evaluate the vacuum pressure at the boundary of the nucleon. This is done by assuming a step function behavior for the running coupling constant of the QCD, which fits nicely to some quantities related to the strong interaction evaluated through the MIT-bag model. (author)

Quantum chromodynamic quark model study of hadron and few hadron systems

International Nuclear Information System (INIS)

Ji, Chueng-Ryong.

1991-05-01

This report details research progress and results obtained during the one year period December 1, 1990 to November 30, 1991. The research project, entitled ''Quantum Chromodynamic Quark Model Study of Hadron and Few Hadron Systems,'' is supported by grant FG05-90ER40589 between North Carolina State University and the United States Department of Energy. In compliance with grant requirements the principal investigator, Professor Chueng-Ryong Ji, has conducted a research program addressing theoretical investigations of hadron structure and reactions using quantum chromodynamic quark models. This principal investigator has devoted 50% of his time during the academic year and 100% of his time in the summer. This percent effort will continue for the remaining period of the grant. The new, significant research results are briefly summarized in the following sections. Recent progress has been reported in the renewal/continuation grant proposal just submitted to the Department of Energy. Finally, full, detailed descriptions of completed work can be found in the project publications which are listed at the end of this progress report

Nuclear chromodynamics: applications of QCD to relativistic multiquark systems

International Nuclear Information System (INIS)

Brodsky, S.J.; Ji, C.R.

1984-07-01

We review the applications of quantum chromodynamics to nuclear multiquark systems. In particular, predictions are given for the deuteron reduced form factor in the high momentum transfer region, hidden color components in nuclear wavefunctions, and the short distance effective force between nucleons. A new antisymmetrization technique is presented which allows a basis for relativistic multiquark wavefunctions and solutions to their evolution to short distances. Areas in which conventional nuclear theory conflicts with QCD are also briefly reviewed. 48 references

Nuclear chromodynamics is not the colorization of nuclear physics

International Nuclear Information System (INIS)

Sivers, D.

1988-01-01

The successful description of nuclei in terms of nucleons, deltas and mesons provides an enormous challenge to QCD. It compels us to pursue our theoretical understanding of chromodynamics into the realm of multiple color singlets in order to examine the concept of color saturation. To pursue this theme, we examine the idea of nuclear transparency in the light of models for confinement and describe the formulation of lattice simulations sensitive to exchange forces. 22 refs., 7 figs

The Spin-dependent Structure Function of the Proton $g_{1}^p$ and a Test of the Bjorken Sum Rule

CERN Document Server

Alekseev, M.G.; Alexandrov, Yu.; Alexeev, G.D.; Amoroso, A.; Austregesilo, A.; Badelek, B.; Balestra, F.; Ball, J.; Barth, J.; Baum, G.; Bedfer, Y.; Bernhard, J.; Bertini, R.; Bettinelli, M.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bravar, A.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M.P.; Chaberny, D.; Cotic, D.; Chiosso, M.; Chung, S.U.; Cicuttin, A.; Colantoni, M.; Crespo, M.L.; Dalla Torre, S.; Das, S.; Dasgupta, S.S.; Denisov, O.Yu.; Dhara, L.; Diaz, V.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Efremov, A.; El Alaoui, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Filin, A.; Finger, M.; Finger, M., Jr.; Fischer, H.; Franco, C.; Friedrich, J.M.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.P.; Gazda, R.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gnesi, I.; Gobbo, B.; Goertz, S.; Grabmuller, S.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Haas, F.; von Harrach, D.; Hasegawa, T.; Heinsius, F.H.; Hermann, R.; Herrmann, F.; Hess, C.; Hinterberger, F.; Horikawa, N.; Hoppner, Ch.; d'Hose, N.; Ilgner, C.; Ishimoto, S.; Ivanov, O.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jasinski, P.; Jegou, G.; Joosten, R.; Kabuss, E.; Kafer, W.; Kang, D.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu.A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konopka, R.; Konorov, I.; Konstantinov, V.F.; Korzenev, A.; Kotzinian, A.M.; Kouznetsov, O.; Kowalik, K.; Kramer, M.; Kral, A.; Kroumchtein, Z.V.; Kuhn, R.; Kunne, F.; Kurek, K.; Lauser, L.; Le Goff, J.M.; Lednev, A.A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Liska, T.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G.K.; Mann, A.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Massmann, F.; Matsuda, T.; Maximov, A.N.; Meyer, W.; Michigami, T.; Mikhailov, Yu.V.; Moinester, M.A.; Mutter, A.; Nagaytsev, A.; Nagel, T.; Nassalski, J.; Negrini, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.I.; Nunes, A.S.; Olshevsky, A.G.; Ostrick, M.; Padee, A.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pawlukiewicz-Kaminska, B.; Perevalova, E.; Pesaro, G.; Peshekhonov, D.V.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V.A.; Pontecorvo, G.; Pretz, J.; Quintans, C.; Rajotte, J.F.; Ramos, S.; Rapatsky, V.; Reicherz, G.; Richter, A.; Robinet, F.; Rocco, E.; Rondio, E.; Ryabchikov, D.I.; Samoylenko, V.D.; Sandacz, A.; Santos, H.; Sapozhnikov, M.G.; Sarkar, S.; Savin, I.A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schmitt, L.; Schluter, T.; Schopferer, S.; Schroder, W.; Shevchenko, O.Yu.; Siebert, H.W.; Silva, L.; Sinha, L.; Sissakian, A.N.; Slunecka, M.; Smirnov, G.I.; Sosio, S.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Sulej, R.; Takekawa, S.; Tessaro, S.; Tessarotto, F.; Teufel, A.; Tkatchev, L.G.; Uhl, S.; Uman, I.; Virius, M.; Vlassov, N.V.; Vossen, A.; Weitzel, Q.; Windmolders, R.; Wislicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zhao, J.; Zhuravlev, N.; Zvyagin, A.

2010-01-01

The inclusive double-spin asymmetry, $A_{1}^{p}$, has been measured at COMPASS in deepinelastic polarised muon scattering off a large polarised NH3 target. The data, collected in the year 2007, cover the range Q2 > 1 (GeV/c)^2, 0.004 < x < 0.7 and improve the statistical precision of g_{1}^{p}(x) by a factor of two in the region x < 0.02. The new proton asymmetries are combined with those previously published for the deuteron to extract the non-singlet spin-dependent structure function g_1^NS(x,Q2). The isovector quark density, Delta_q_3(x,Q2), is evaluated from a NLO QCD fit of g_1^NS. The first moment of Delta_q3 is in good agreement with the value predicted by the Bjorken sum rule and corresponds to a ratio of the axial and vector coupling constants g_A/g_V = 1.28+-0.07(stat)+-0.10(syst).

Commensurate scale relations: Precise tests of quantum chromodynamics without scale or scheme ambiguity

International Nuclear Information System (INIS)

Brodsky, S.J.; Lu, H.J.

1994-10-01

We derive commensurate scale relations which relate perturbatively calculable QCD observables to each other, including the annihilation ratio R e+ e - , the heavy quark potential, τ decay, and radiative corrections to structure function sum rules. For each such observable one can define an effective charge, such as α R (√s)/π ≡ R e+ e - (√s)/(3Σe q 2 )-1. The commensurate scale relation connecting the effective charges for observables A and B has the form α A (Q A ) α B (Q B )(1 + r A/Bπ / αB + hor-ellipsis), where the coefficient r A/B is independent of the number of flavors ∫ contributing to coupling renormalization, as in BLM scale-fixing. The ratio of scales Q A /Q B is unique at leading order and guarantees that the observables A and B pass through new quark thresholds at the same physical scale. In higher orders a different renormalization scale Q n* is assigned for each order n in the perturbative series such that the coefficients of the series are identical to that of a invariant theory. The commensurate scale relations and scales satisfy the renormalization group transitivity rule which ensures that predictions in PQCD are independent of the choice of an intermediate renormalization scheme C. In particular, scale-fixed predictions can be made without reference to theoretically constructed singular renormalization schemes such as MS. QCD can thus be tested in a new and precise way by checking that the effective charges of observables track both in their relative normalization and in their commensurate scale dependence. The commensurate scale relations which relate the radiative corrections to the annihilation ratio R e + e - to the radiative corrections for the Bjorken and Gross-Llewellyn Smith sum rules are particularly elegant and interesting

The Zb(10610) and Zb(10650) as axial-vector tetraquark states in the QCD sum rules

International Nuclear Information System (INIS)

Wang, Zhi-Gang; Huang, Tao

2014-01-01

In this article, we study the axial-vector mesons Z b (10610) and Z b (10650) with the Cγ μ –Cγ 5 type and Cγ μ –Cγ ν type interpolating currents, respectively, by carrying out the operator product expansion to the vacuum condensates up to dimension 10. In calculations, we explore the energy scale dependence of the QCD spectral densities of the hidden bottom tetraquark states in detail for the first time, and suggest a formula μ=√(M X/Y/Z 2 −(2M b ) 2 ) with the effective mass M b =5.13 GeV to determine the energy scales. The numerical results favor assigning the Z b (10610) and Z b (10650) as the Cγ μ –Cγ 5 type and Cγ μ –Cγ ν type hidden bottom tetraquark states, respectively. We obtain the mass of the J PC =1 ++ hidden bottom tetraquark state as a byproduct, which can be compared to the experimental data in the futures. Furthermore, we study the strong decays Z b ± (10610)→ϒπ ± ,η b ρ ± with the three-point QCD sum rules, the decay widths also support assigning the Z b (10610) as the Cγ μ –Cγ 5 type hidden bottom tetraquark state

Precision calculation of threshold {pi}{sup -}d scattering, {pi}N scattering lengths, and the GMO sum rule

Energy Technology Data Exchange (ETDEWEB)

Baru, V. [Institut fuer Theoretische Physik II, Ruhr-Universitaet Bochum, D-44870 Bochum (Germany); Institut fuer Kernphysik and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Institute for Theoretical and Experimental Physics, B. Cheremushinskaya 25, 117218 Moscow (Russian Federation); Hanhart, C. [Institut fuer Kernphysik and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Institute for Advanced Simulation, Forschungszentrum Juelich, D-52425 Juelich (Germany); Hoferichter, M., E-mail: hoferichter@hiskp.uni-bonn.de [Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany); Institute of Nuclear and Particle Physics and Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States); Kubis, B. [Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany); Nogga, A. [Institut fuer Kernphysik and Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Institute for Advanced Simulation, Forschungszentrum Juelich, D-52425 Juelich (Germany)

2011-12-15

We use chiral perturbation theory (ChPT) to calculate the {pi}{sup -}d scattering length with an accuracy of a few percent, including isospin-violating corrections in both the two- and three-body sectors. In particular, we provide the technical details of a recent letter (Baru et al., 2011) , where we used data on pionic deuterium and pionic hydrogen atoms to extract the isoscalar and isovector pion-nucleon scattering lengths a{sup +} and a{sup -}. We study isospin-breaking contributions to the three-body part of a{sub {pi}}{sup -}{sub d} due to mass differences, isospin violation in the {pi}N scattering lengths, and virtual photons. This last class of effects is ostensibly infrared enhanced due to the smallness of the deuteron binding energy. However, we show that the leading virtual-photon effects that might undergo such enhancement cancel, and hence the standard ChPT counting provides a reliable estimate of isospin violation in a{sub {pi}}{sup -}{sub d} due to virtual photons. Finally, we discuss the validity of the Goldberger-Miyazawa-Oehme sum rule in the presence of isospin violation, and use it to determine the charged-pion-nucleon coupling constant.

Introduction to quantum chromodynamics (QCD) and the physics of jets

International Nuclear Information System (INIS)

Billoire, Alain; Napoly, Olivier.

1980-12-01

These lecture notes constitute an introduction to Quantum Chromodynamics (QCD), theory of strong interactions. After an elementary presentation of the essential theoretical tools (Lagrangian, renormalization group) and of their consequences for QCD (asymptotic freedom, scaling invariance), we use these to study jets in e + e - annihilation. We thus deal with the problem of infrared divergences and, finally, with the one of the indirect experimental detection of the gluon [fr

Signatures of chromodynamics in hadron collisions

International Nuclear Information System (INIS)

Halzen, F.

1979-01-01

The quantum chromodynamics (QCD) describes the interaction of the parton constituents of hadrons (quarks and gluons) via eight colored photons (gluons) interacting with the quarks, and unlike the photons, with each other. The simple picture of Drell-Yan model has made surprising success. The marriage of the old fashion Drell-Yan parton model with QCD has not only made its phenomenological success in the study of lepton pair production, but has allowed to study quantitatively the gluon correction to the model. Information from beam dump and emulsion experiments on charm production is compared with the typical QCD diagram. The results indicate some possible non-perturbative contribution to the photon- and hadron-production of heavy quarks. The definite features of dilepton as well as large transverse momentum data are direct signature of gluons. (Kato, T.)

Is quantum chromodynamics effectively perturbative everywhere

International Nuclear Information System (INIS)

Misra, S.P.; Pati, J.C.

1980-07-01

We have examined the possibility that QCD processes may be well represented effectively by the Born terms even in the infra-red regime. This appears to be possible if we take not only the running coupling constant but also the running quark and gluon masses in the liberated version of quantum chromodynamics. These running masses appear to suppress the higher order loop corrections compared to the Born diagram even when the running coupling constant increases in the infra-red regime. An explicit interpolating form of the running coupling constant from the ultraviolet to the infra-red regime proposed recently is examined in the context of renormalization group equation. The corresponding β function has an essential singularity at g=0, which suggests the non-perturbative nature of the solutions. (author)

Scalar quantum chromodynamics in two dimensions and parton model

International Nuclear Information System (INIS)

Shei, S.S.; Tsao, H.S.

1977-05-01

The SU(N) scalar quantum chromodynamics in two space-time dimensions in the large N limit are studied. This is the model of color gauge fields interacting with scalar quarks. It is found that the consensual properties of the four dimensional QCD, i.e., the infrared slavery, quark confinement, the charmonium picture etc. are all realized. Moreover, the current in this model mimics nicely the behaviors of current in the four dimensional QCD, in contrast to the original model of 't Hooft

Lattice gauge theory approach to quantum chromodynamics

International Nuclear Information System (INIS)

Kogut, J.B.

1983-01-01

The author reviews in a pedagogical fashion some of the recent developments in lattice quantum chromodynamics. This review emphasizes explicit examples and illustrations rather than general proofs and analyses. It begins with a discussion of the heavy-quark potential in continuum quantum chromodynamics. Asymptotic freedom and renormalization-group improved perturbation theory are discussed. A simple dielectric model of confinement is considered as an intuitive guide to the vacuum of non-Abelian gauge theories. Next, the Euclidean form of lattice gauge theory is introduced, and an assortment of calculational methods are reviewed. These include high-temperature expansions, duality, Monte Carlo computer simulations, and weak coupling expansions. A #betta#-parameter calculation for asymptotically free-spin models is presented. The Hamiltonian formulation of lattice gauge theory is presented and is illustrated in the context of flux tube dynamics. Roughening transitions, Casimir forces, and the restoration of rotational symmetry are discussed. Mechanisms of confinement in lattice theories are illustrated in the two-dimensional electrodynamics of the planar model and the U(1) gauge theory in four dimensions. Generalized actions for SU(2) gauge theories and the relevance of monopoles and strings to crossover phenomena are considered. A brief discussion of the continuity of fields and topologial charge in asymptotically free lattice models is presented. The final major topic of this review concerns lattice fermions. The species doubling problem and its relation to chiral symmetry are illustrated. Staggered Euclidean fermion methods are discussed in detail, with an emphasis on species counting, remnants of chiral symmetry, Block spin variables, and the axial anomaly. Numerical methods for including fermions in computer simulations are considered. Jacobi and Gauss-Siedel inversion methods to obtain the fermion propagator in a background gauge field are reviewed

Multi-Hadron Observables from Lattice Quantum Chromodynamics

Energy Technology Data Exchange (ETDEWEB)

Hansen, Maxwell [Univ. of Washington, Seattle, WA (United States)

2014-01-01

We describe formal work that relates the nite-volume spectrum in a quantum eld theory to scattering and decay amplitudes. This is of particular relevance to numerical calculations performed using Lattice Quantum Chromodynamics (LQCD). Correlators calculated using LQCD can only be determined on the Euclidean time axis. For this reason the standard method of determining scattering amplitudes via the Lehmann-Symanzik-Zimmermann reduction formula cannot be employed. By contrast, the nite-volume spectrum is directly accessible in LQCD calculations. Formalism for relating the spectrum to physical scattering observables is thus highly desirable. In this thesis we develop tools for extracting physical information from LQCD for four types of observables. First we analyze systems with multiple, strongly-coupled two-scalar channels. Here we accommodate both identical and nonidentical scalars, and in the latter case allow for degenerate as well as nondegenerate particle masses. Using relativistic eld theory, and summing to all orders in perturbation theory, we derive a result relating the nite-volume spectrum to the two-to-two scattering amplitudes of the coupled-channel theory. This generalizes the formalism of Martin L uscher for the case of single-channel scattering. Second we consider the weak decay of a single particle into multiple, coupled two-scalar channels. We show how the nite-volume matrix element extracted in LQCD is related to matrix elements of asymptotic two-particle states, and thus to decay amplitudes. This generalizes work by Laurent Lellouch and Martin L uscher. Third we extend the method for extracting matrix elements by considering currents which insert energy, momentum and angular momentum. This allows one to extract transition matrix elements and form factors from LQCD. Finally we look beyond two-particle systems to those with three-particles in asymptotic states. Working again to all orders in relativistic eld theory, we derive a relation between the

Lepton-hadron scattering from scaling violation to HERA

International Nuclear Information System (INIS)

Sciulli, F.

1992-01-01

The author starts his lecture with a personal remembrance of the appearance of scaling, and its experimental verification with data from Gargamelle and SLAC. Feynmann's parton model was developing, and the discovery and acceptance of quarks fit into this model. He covers areas of the parton model related to u, d, and strange quark densities, and effects of nuclear environment on the parton densities. Deep inelastic scattering results provided significant data and many results for theoretical interpretation. The development and application of quantum chromodynamics (QCD) is reviewed and applied to deep inelastic scattering results. He reviews major sum rules, and takes a phenomenological perspective to describe how the sum rules follow simply from the quark model, and how experiments compare to the predictions. Finally he touches on the many new processes found and sought through the use of the deep inelastic process. The 'new' field of deep inelastic scattering is still going strong

Remarks on broken chiral SU(5) x SU(5) symmetry and B mesons

International Nuclear Information System (INIS)

Kim, D.Y.; Sinha, S.N.

1985-01-01

In a recent paper, Hatzis has estimated the masses and weak decay constants of b-flavored pseudoscalar mesons in a broken chiral SU(5) x SU(5) symmetry method. The estimated weak decay constant of B meson, f sub(B) f sub(K)(f sub(B)/f sub(K) approximately equal to 1.4) evaluated by Mathur et al. with the quantum chromodynamics (QCD) sum-rule model. We re-examined the problem applying the broken chiral SU(5) x SU(5) symmetry approach using a set of mass formulae. With this method we estimate the symmetry-breaking parameters and decay constants of pseudoscalar mesons. We found a consistent result for the decay constant: f sub(K) < or approximately equal to f sub(D) < or approximately equal to f sub(B). The explicit numerical value of these constants, however, are lower than that of the QCD sum rule. This may be due to the limited validity of the broken chiral symmetry approach for heavy mesons

Quantum chromodynamics at large distances

International Nuclear Information System (INIS)

Arbuzov, B.A.

1987-01-01

Properties of QCD at large distances are considered in the framework of traditional quantum field theory. An investigation of asymptotic behaviour of lower Green functions in QCD is the starting point of the approach. The recent works are reviewed which confirm the singular infrared behaviour of gluon propagator M 2 /(k 2 ) 2 at least under some gauge conditions. A special covariant gauge comes out to be the most suitable for description of infrared region due to absence of ghost contributions to infrared asymptotics of Green functions. Solutions of Schwinger-Dyson equation for quark propagator are obtained in this special gauge and are shown to possess desirable properties: spontaneous breaking of chiral invariance and nonperturbative character. The infrared asymptotics of lower Green functions are used for calculation of vacuum expectation values of gluon and quark fields. These vacuum expectation values are obtained in a good agreement with the corresponding phenomenological values which are needed in the method of sum rules in QCD, that confirms adequacy of the infrared region description. The consideration of a behaviour of QCD at large distances leads to the conclusion that at contemporary stage of theory development one may consider two possibilities. The first one is the well-known confinement hypothesis and the second one is called incomplete confinement and stipulates for open color to be observable. Possible manifestations of incomplete confinement are discussed

Quarkonia

CERN Document Server

1992-01-01

The discovery of the two families of heavy-quark-antiquark bound states, the &Ugr; and &PSgr; quarkonium spectroscopies, has played a crucial role in unravelling the nature of strong interactions. The articles collected together in this volume are concerned with the connection between quarkonia and quantum chromodynamics. They deal with potential models, spin-dependent forces, next-to-leading order QCD corrections for decay widths and energy level differences, hadronic transitions and the quark-antiquark interaction in QCD, based on perturbation theory, lattice gauge theory and QCD sum rules

The 3-loop non-singlet heavy flavor contributions to the structure function g1(x,Q2 at large momentum transfer

Directory of Open Access Journals (Sweden)

A. Behring

2015-08-01

Full Text Available We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the polarized structure function g1(x,Q2 in the asymptotic region Q2≫m2 to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N and the momentum fraction x, and derive heavy flavor corrections to the Bjorken sum-rule. Numerical results are presented for the charm quark contribution. Results on the structure function g2(x,Q2 in the twist-2 approximation are also given.

Appropriate definition of the scale parameter Λ in quantum chromodynamics

International Nuclear Information System (INIS)

Monsay, E.; Rosenzweig, C.

1981-01-01

Even after we have chosen a specific definition of the quantum-chromodynamic coupling constant (e.g., modified minimal subtraction or momentum-space subtraction) we are free to choose a definition of Λ when we expand the coupling constant in powers of (lnQ 2 /Λ 2 ) -1 . We discuss in detail a particular definition suggested by Abbott and argue that this definition does seem to provide an attractive means of fixing Λ

Workshop on nuclear chromodynamics: Quarks and gluons in particles and nuclei

International Nuclear Information System (INIS)

Brodsky, S.; Moniz, E.

1985-01-01

The assertion that quantum chromodynamics (QCD) is the correct theory describing strong interaction phenomena has, largely by repetition, become rather non-controversial. It is likely even true. However, whether or not it is correct in detail, the experimentally supported realization that colored quarks and gluons are the elementary degrees of freedom, that asymptotic freedom makes short distance phenomena rather ''simple'' to understand, and that color is confined on the hadronic length scale of -- 1 fm has led to a profound change in the character of our attempts to understand the structure and interactions of both hadrons and nuclei. Many of the most important issued in particle physics and in nuclear physics are now seen to be intimately connected. An understanding of the validity and limits of effective theories based upon hadron degrees of freedom, so phenomenologically successful in describing a host of low energy phenomena, is coming into focus. The existence of new forms of matter grounded in the hidden color degree of freedom is predicted. These considerations form the subject of nuclear chromodynamics (NCD). The subject is far from mature and is developing rapidly

Estimates of md-mu and left-angle bar dd right-angle -left-angle bar uu right-angle from QCD sum rules for D and D* isospin mass differences

International Nuclear Information System (INIS)

Eletsky, V.L.; Ioffe, B.L.

1993-01-01

The recent experimental data on D +- D0 and D *+- D*0 mass differences are used as inputs in the QCD sum rules to obtain new estimates on the mass difference of light quarks and on the difference of their condensates: m d -m u =3±1 MeV, left-angle bar dd right-angle -left-angle bar uu right-angle=-(2.5±1)x10 -3 left-angle bar uu right-angle (at a standard normalization point, μ=0.5 GeV)

Foundations of quantum chromodynamics: Perturbative methods in gauge theories

International Nuclear Information System (INIS)

Muta, T.

1986-01-01

This volume develops the techniques of perturbative QCD in great detail starting with field theory. Aside from extensive treatments of the renormalization group technique, the operator product expansion formalism and their applications to short-distance reactions, this book provides a comprehensive introduction to gauge field theories. Examples and exercises are provided to amplify the discussions on important topics. Contents: Introduction; Elements of Quantum Chromodynamics; The Renormalization Group Method; Asymptotic Freedom; Operator Product Expansion Formalism; Applications; Renormalization Scheme Dependence; Factorization Theorem; Further Applications; Power Corrections; Infrared Problem. Power Correlations; Infrared Problem

Quantum chromodynamics: A theory of the nuclear force

International Nuclear Information System (INIS)

Craigie, N.S.

1980-06-01

A brief outline is given of a possible theory of the nuclear force and the strong interactions between elementary particles, which is supposed responsible for nuclear matter. The theory is known as quantum chromodynamics because of its association with a new kind of nuclear charge called colour and its resemblance to quantum electrodynamics. Early ideas on the nuclear force and the emergence of the quark model and the QCD Lagrangian are described first. Then properties of this theory and the problem of quark confinement, the perturbative phase of QCD, and the non-perturbative or confinement phase of QCD and the description of hadrons and their interactions are discussed

Scalar quantum chromodynamics in two dimensions and the parton model

International Nuclear Information System (INIS)

Shei, S.S.; Tsao, H.-S.

1978-01-01

SU(N) scalar quantum chromodynamics is studied in two space-time dimensions in the large-N limit. This is the model of color gauge fields interacting with scalar quarks. It is found that the consensual properties of four-dimensional QCD, i.e. infrared slavery, quark confinement, the charmonium picture. etc, are all realized. Moreover, the current in this model mimics nicely the behaviour of the current in four-dimensional QCD, in contrast to the original model of 't Hooft. (Auth.)

Measurement of the lepton {tau} spectral functions and applications to quantum chromodynamic; Mesure des fonctions spectrales du lepton {tau} et applications a la chromodynamique quantique

Energy Technology Data Exchange (ETDEWEB)

Hoecker, A [Paris-11 Univ., 91 - Orsay (France). Lab. de l' Accelerateur Lineaire; [Universite de Paris Sud, 91 - Orsay (France)

1997-04-18

This thesis presents measurements of the {tau} vector (V) and axial-vector (A) hadronic spectral functions and phenomenological studies in the framework of quantum chromodynamics (QCD). Using the hypothesis of conserved vector currents (CVC), the dominant two- and four-pion vector spectral functions are compared to the corresponding cross sections from e{sup +}e{sup -} annihilation. A combined fit of the pion form factor from {tau} decays and e{sup +}e{sup -} data is performed using different parametrizations. The mass and the width of the {rho}{sup {+-}}(770) and the {rho}{sup 0}(770) are separately determined in order to extract possible isospin violating effects. The mass and width differences are measured to be M{sub {rho}{sup {+-}}{sub (770)} - M{sub {rho}{sup 0}}{sub (770)}=(0.0{+-}1.0) MeV/c{sup 2} and {gamma}{sub {rho}{sup {+-}}{sub (770)} - {gamma}{sub {rho}{sup 0}}{sub (770)}=(0.1 {+-} 1.9) MeV/c{sup 2}. Several QCD chiral sum rules involving the difference (V - A) of the spectral functions are compared to their measurements. The Borel-transformed Das-Mathur-Okubo sum rule is used to measure the pion polarizability to be {alpha}{sub E}=(2.68{+-}0.91) x 10{sup -4} fm{sup 3}. The {tau} vector and axial-vector hadronic widths and certain spectral moments are exploited to measure {alpha}{sub s} and non-perturbative contributions at the {tau} mass scale. The best, and experimentally and theoretically most robust, determination of {alpha}{sub s}(M{sub {tau}}) is obtained from the inclusive (V + A) fit that yields {alpha}{sub s}(M{sub {tau}})= 0.348{+-}0.017 giving {alpha}{sub s}(M{sub Z})=0.1211 {+-} 0.0021 after the evolution to the mass of the Z boson. The approach of the Operator Product Expansion (OPE) is tested experimentally by means of an evolution of the {tau} hadronic width to masses smaller that the {tau} mass. Using the difference (V - A) of the spectral functions allows one to directly measure the dominant non-perturbative OPE dimension to be D=6

Measurement sum theory and application - Application to low level measurements

International Nuclear Information System (INIS)

Puydarrieux, S.; Bruel, V.; Rivier, C.; Crozet, M.; Vivier, A.; Manificat, G.; Thaurel, B.; Mokili, M.; Philippot, B.; Bohaud, E.

2015-09-01

In laboratories, most of the Total Sum methods implemented today use substitution or censure methods for nonsignificant or negative values, and thus create biases which can sometimes be quite large. They are usually positive, and generate, for example, becquerel (Bq) counting or 'administrative' quantities of materials (= 'virtual'), thus artificially falsifying the records kept by the laboratories under regulatory requirements (environment release records, waste records, etc.). This document suggests a methodology which will enable the user to avoid such biases. It is based on the following two fundamental rules: - The Total Sum of measurement values must be established based on all the individual measurement values, even those considered non-significant including the negative values. Any modification of these values, under the pretext that they are not significant, will inevitably lead to biases in the accumulated result and falsify the evaluation of its uncertainty. - In Total Sum operations, the decision thresholds are arrived at in a similar way to the approach used for uncertainties. The document deals with four essential aspects of the notion of 'measurement Total Sums': - The expression of results and associated uncertainties close to Decision Thresholds, and Detection or Quantification Limits, - The Total Sum of these measurements: sum or mean, - The calculation of the uncertainties associated with the Total Sums, - Result presentation (particularly when preparing balance sheets or reports, etc.) Several case studies arising from different situations are used to illustrate the methodology: environmental monitoring reports, release reports, and chemical impurity Total Sums for the qualification of a finished product. The special case of material balances, in which the measurements are usually all significant and correlated (the covariance term cannot then be ignored) will be the subject of a future second document. This

Reanalysis of the Y(3940), Y(4140), Zc(4020), Zc(4025), and Zb(10650) as molecular states with QCD sum rules

International Nuclear Information System (INIS)

Wang, Zhi-Gang

2014-01-01

In this article, we calculate the contributions of the vacuum condensates up to dimension 10 in the operator product expansion, and study the J PC = 0 ++ , 1 +- , 2 ++ D * anti D * , D s * anti D s * , B * anti B * , B s * anti B s * molecular states with the QCD sum rules. In the calculations, we use the formula μ = √(M 2 X/Y/Z -(2M Q ) 2 ) to determine the energy scales of the QCD spectral densities. The numerical results favor assigning the Z c (4020) and Z c (4025) to the J PC = 0 ++ , 1 +- or 2 ++ D * anti D * molecular states, the Y(4140) to the J PC = 0 ++ D s * anti D s * molecular state, the Z b (10650) to the J PC = 1 +- B * anti B * molecular state, and they disfavor assigning the Y(3940) to the (J PC = 0 ++ ) molecular state. The present predictions can be confronted with the experimental data in the future. (orig.)

Process-independent strong running coupling

International Nuclear Information System (INIS)

Binosi, Daniele; Mezrag, Cedric; Papavassiliou, Joannis; Roberts, Craig D.; Rodriguez-Quintero, Jose

2017-01-01

Here, we unify two widely different approaches to understanding the infrared behavior of quantum chromodynamics (QCD), one essentially phenomenological, based on data, and the other computational, realized via quantum field equations in the continuum theory. Using the latter, we explain and calculate a process-independent running-coupling for QCD, a new type of effective charge that is an analogue of the Gell-Mann–Low effective coupling in quantum electrodynamics. The result is almost identical to the process-dependent effective charge defined via the Bjorken sum rule, which provides one of the most basic constraints on our knowledge of nucleon spin structure. As a result, this reveals the Bjorken sum to be a near direct means by which to gain empirical insight into QCD's Gell-Mann–Low effective charge.

Quantum chromodynamics in few-nucleon systems

International Nuclear Information System (INIS)

Brodsky, S.J.

1983-10-01

One of the most important implications of quantum chromodynamics (QCD) is that nuclear systems and forces can be described at a fundamental level. The theory provides natural explanations for the basic features of hadronic physics: the meson and baryon spectra, quark statistics, the structure of the weak and electromagnetic currents of hadrons, the scale-invariance of hadronic interactions at short distances, and evidently, color (i.e., quark and gluon) confinement at large distances. Many different and diverse tests have confirmed the basic predictions of QCD; however, since tests of quark and gluon interactions must be done within the confines of hadrons there have been few truly quantitative checks. Nevertheless, it appears likely that QCD is the fundamental theory of hadronic and nuclear interactions in the same sense that QED gives a precise description of electrodynamic interctions. Topics discussed include exclusive processes in QCD, the deuteron in QCD, reduced nuclear amplitudes, and limitations of traditional nuclear physics. 32 references

Nuclear Theory Group, University of Washington recent and planned research

International Nuclear Information System (INIS)

1993-01-01

The work of the five staff members is presented individually in turn. (1) Nonperturbative aspects of quantum chromodynamics and its implication for phenomena involving nucleon structure, nuclear structure, and relativistic heavy-ion collisions. (2) Symmetries and the connection of the quark-gluon description of nucleons and nuclei with the nucleon-meson degrees of freedom-parity nonconservation, time reversal invariance, chiral symmetry and charge symmetry, QCD sum rules. (3) The relation between nuclear physics and quantum chromodynamics-physics of color transparency, fundamental symmetries, physics of confinement and hadronic form factors, EMC effect. (4) Chirally invariant chromo-dielectric soliton model, many-nucleon system in models of QCD, flux tube dynamics, anti p-p to anti Λ-Λ and anti Λ-Σ collisions, isotopic effects in atomic parity nonconservation, quantum molecular dynamics. (5) Numerical work related to lattice QCD simulations, and analytical work related to model studies of hadronic phenomenology and the development and understanding of new methods

Parton densities in quantum chromodynamics gauge invariance, path-dependence and Wilson lines

CERN Document Server

Cherednikov, Igor O

2016-01-01

The purpose of this book is to give a systematic pedagogical exposition of the quantitative analysis of Wilson lines and loops in quantum chromodynamics. Using techniques from the previous volume (Wilson Lines in Quantum Field Theory, 2014), ab initio techniques are developed and practical tools for their implementation presented. An emphasis is put on their renormalization and on implications on processes observable at experimental facilities.

Quantum chromodynamics and the derivation of a microscopic theory of the nucleus

International Nuclear Information System (INIS)

Sliv, L.A.; Strikman, M.I.; Frankfurt, L.L.

1985-01-01

The progress which has already been made in the construction of a microscopic theory of the nucleus on the basis of quantum chromodynamics, the problems remaining, and the outlook for future progress are analyzed. The problem of nuclear forces, the role played by a high-momentum component in the nuclear wave function, and the role played by relativistic effects in various hard nuclear processes are discussed

The degree of 5f electron localization in URu2Si2: electron energy-loss spectroscopy and spin-orbit sum rule analysis

Energy Technology Data Exchange (ETDEWEB)

Jeffries, J R; Moore, K T; Butch, N P; Maple, M B

2010-05-19

We examine the degree of 5f electron localization in URu{sub 2}Si{sub 2} using spin-orbit sum rule analysis of the U N{sub 4,5} (4d {yields} 5f) edge. When compared to {alpha}-U metal, US, USe, and UTe, which have increasing localization of the 5f states, we find that the 5f states of URu{sub 2}Si{sub 2} are more localized, although not entirely. Spin-orbit analysis shows that intermediate coupling is the correct angular momentum coupling mechanism for URu{sub 2}Si{sub 2} when the 5f electron count is between 2.6 and 2.8. These results have direct ramifications for theoretical assessment of the hidden order state of URu{sub 2}Si{sub 2}, where the degree of localization of the 5f electrons and their contribution to the Fermi surface are critical.

The O(α3s) Heavy Flavor Contributions to the Charged Current Structure Function xF3(x,Q2) at Large Momentum Transfer

International Nuclear Information System (INIS)

Behring, A.; Bluemlein, J.; Freitas, A. de; Johannes Kepler Univ., Linz; Hasselhuhn, A.; Manteuffel, A. von; Schneider, C.

2015-08-01

We calculate the massive Wilson coefficients for the heavy flavor contributions to the non-singlet charged current deep-inelastic scattering structure function xF W+ 3 (x,Q 2 )+xF W- 3 (x,Q 2 ) in the asymptotic region Q 2 >>m 2 to 3-loop order in Quantum Chromodynamics (QCD) at general values of the Mellin variable N and the momentum fraction x. Besides the heavy quark pair production also the single heavy flavor excitation s→c contributes. Numerical results are presented for the charm quark contributions and consequences on the Gross-Llewellyn Smith sum rule are discussed.

Quark virtuality and QCD vacuum condensates

International Nuclear Information System (INIS)

Zhou Lijuan; Ma Weixing

2004-01-01

Based on the Dyson-Schwinger equations (DSEs) in the 'rainbow' approximation, the authors investigate the quark virtuality in the vacuum state and quantum-chromodynamics (QCD) vacuum condensates. In particular, authors calculate the local quark vacuum condensate and quark-gluon mixed condensates, and then the virtuality of quark. The calculated quark virtualities are λ u,d 2 =0.7 GeV 2 for u, d quarks, and λ s 2 =1.6 GeV 2 for s quark. The theoretical predictions are consistent with empirical values used in QCD sum rules, and also fit to lattice QCD predictions

Singular charge density at the center of the pion?

International Nuclear Information System (INIS)

Miller, Gerald A.

2009-01-01

We relate the three-dimensional infinite momentum frame spatial charge density of the pion to its electromagnetic form factor F π (Q 2 ). Diverse treatments of the measured form factor data including phenomenological fits, nonrelativistic quark models, the application of perturbative quantum chromodynamics (QCD), QCD sum rules, holographic QCD, and the Nambu-Jona-Lasinio (NJL) model all lead to the result that the charge density at the center of the pion has a logarithmic divergence. Relativistic constituent quark models do not display this singularity. Future measurements planned for larger values of Q 2 may determine whether or not a singularity actually occurs.

The Spin Structure Function $g_1^{\\rm p}$ of the Proton and a Test of the Bjorken Sum Rule

CERN Document Server

Adolph, C.; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Azevedo, C.; Badelek, B.; Balestra, F.; Barth, J.; Baum, G.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buchele, M.; Burtin, E.; Capozza, L.; Chang, W.C.; Chiosso, M.; Choi, I.; Chung, S.U.; Cicuttin, A.; Crespo, M.L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Dhara, L.; Donskov, S.V.; Doshita, N.; Duic, V.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Ferrero, A.; Finger, M.; M. Finger jr; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmuller, S.; Grasso, A.; Grosse-Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F.H.; Herrmann, F.; Hinterberger, F.; Horikawa, N.; d'Hose, N.; Hsieh, C.Yu; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jorg, P.; Joosten, R.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.; Kramer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z.V.; Kuchinski, N.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Longo, R.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.K.; Marchand, C.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nunes, A.S.; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.C.; Pereira, F.; Pesek, M.; Peshekhonov, D.V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Rocco, E.; Rossiyskaya, N.S.; Ryabchikov, D.I.; Rychter, A.; Samoylenko, V.D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I.A.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schonning, K.; Schopferer, S.; Selyunin, A.; Shevchenko, O.Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Wolbeek, J. ter; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tosello, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Weisrock, T.; Wilfert, M.; Windmolders, R.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

2016-02-10

New results for the double spin asymmetry $A_1^{\\rm p}$ and the proton longitudinal spin structure function $g_1^{\\rm p}$ are presented. They were obtained by the COMPASS collaboration using polarised 200 GeV muons scattered off a longitudinally polarised NH$_3$ target. The data were collected in 2011 and complement those recorded in 2007 at 160\\,GeV, in particular at lower values of $x$. They improve the statistical precision of $g_1^{\\rm p}(x)$ by about a factor of two in the region $x\\lesssim 0.02$. A next-to-leading order QCD fit to the $g_1$ world data is performed. It leads to a new determination of the quark spin contribution to the nucleon spin, $\\Delta \\Sigma$ ranging from 0.26 to 0.36, and to a re-evaluation of the first moment of $g_1^{\\rm p}$. The uncertainty of $\\Delta \\Sigma$ is mostly due to the large uncertainty in the present determinations of the gluon helicity distribution. A new evaluation of the Bjorken sum rule based on the COMPASS results for the non-singlet structure function $g_1^{\\rm...

Polarization phenomena in quantum chromodynamics

Energy Technology Data Exchange (ETDEWEB)

Brodsky, S.J. [Stanford Univ., CA (United States)

1994-12-01

The author discusses a number of interrelated hadronic spin effects which test fundamental features of perturbative and nonperturbative QCD. For example, the anomalous magnetic moment of the proton and the axial coupling g{sub A} on the nucleon are shown to be related to each other for fixed proton radius, independent of the form of the underlying three-quark relativistic quark wavefunction. The renormalization scale and scheme ambiguities for the radiative corrections to the Bjorken sum rule for the polarized structure functions can be eliminated by using commensurate scale relations with other observables. Other examples include (a) new constraints on the shape and normalization of the polarized quark and gluon structure functions of the proton at large and small x{sub bj}; (b) consequences of the principle of hadron retention in high x{sub F} inclusive reactions; (c) applications of hadron helicity conservation to high momentum transfer exclusive reactions; and (d) the dependence of nuclear structure functions and shadowing on virtual photon polarization. The author also discusses the implications of a number of measurements which are in striking conflict with leading-twist perturbative QCD predictions, such as the extraordinarily large spin correlation A{sub NN} observed in large angle proton-proton scattering, the anomalously large {rho}{pi} branching ratio of the J/{psi}, and the rapidly changing polarization dependence of both J/{psi} and continuum lepton pair hadroproduction observed at large x{sub F}. The azimuthal angular dependence of the Drell-Yan process is shown to be highly sensitive to the projectile distribution amplitude, the fundamental valence light-cone wavefunction of the hadron.

Polarization phenomena in quantum chromodynamics

International Nuclear Information System (INIS)

Brodsky, S.J.

1994-03-01

The author discusses a number of interrelated hadronic spin effects which test fundamental features of perturbative and non-perturbative QCD. For example, the anomalous magnetic moment of the proton and the axial coupling g A on the nucleon are shown to be related to each other for fixed proton radius, independent of the form of the underlying three-quark relativistic quark wavefunction. The renormalization scale and scheme ambiguities for the radiative corrections to the Bjorken sum rule for the polarized structure functions can be eliminated by using commensurate scale relations with other observables. Other examples include (a) new constraints on the shape and normalization of the polarized quark and gluon structure functions of the proton at large and small x bj ; (b) consequences of the principle of hadron helicity retention in high x F inclusive reactions; (c) applications of hadron helicity conservation to high momentum transfer exclusive reactions; and (d) the dependence of nuclear structure functions and shadowing on virtual photon polarization. He also discusses the implications of a number of measurements which are in striking conflict with leading-twist perturbative QCD predictions, such as the extraordinarily large spin correlation A NN observed in large angle proton-proton scattering, the anomalously large ρπ branching ratio of the J/ψ, and the rapidly changing polarization dependence of both J/ψ and continuum lepton pair hadroproduction observed at large x F . The azimuthal angular dependence of the Drell-Yan process is shown to be highly sensitive to the projectile distribution amplitude, the fundamental valence light-cone wavefunction of the hadron

Quarks and gluons in the phase diagram of quantum chromodynamics

Energy Technology Data Exchange (ETDEWEB)

Welzbacher, Christian Andreas

2016-07-14

In this dissertation we study the phase diagram of strongly interacting matter by approaching the theory of quantum chromodynamics in the functional approach of Dyson-Schwinger equations. With these quantum (field) equations of motions we calculate the non-perturbative quark propagator within the Matsubara formalism. We built up on previous works and extend the so-called truncation scheme, which is necessary to render the infinite tower of Dyson-Schwinger equations finite and study phase transitions of chiral symmetry and the confinement/deconfinement transition. In the first part of this thesis we discuss general aspects of quantum chromodynamics and introduce the Dyson-Schwinger equations in general and present the quark Dyson-Schwinger equation together with its counterpart for the gluon. The Bethe-Salpeter equation is introduced which is necessary to perform two-body bound state calculations. A view on the phase diagram of quantum chromodynamics is given, including the discussion of order parameter for chiral symmetry and confinement. Here we also discuss the dependence of the phase structure on the masses of the quarks. In the following we present the truncation and our results for an unquenched N{sub f} = 2+1 calculation and compare it to previous studies. We highlight some complementary details for the quark and gluon propagator and discus the resulting phase diagram, which is in agreement with previous work. Results for an equivalent of the Columbia plot and the critical surface are discussed. A systematically improved truncation, where the charm quark as a dynamical quark flavour is added, will be presented in Ch. 4. An important aspect in this investigation is the proper adjustment of the scales. This is done by matching vacuum properties of the relevant pseudoscalar mesons separately for N{sub f} = 2+1 and N f = 2+1+1 via a solution of the Bethe-Salpeter equation. A comparison of the resulting N{sub f} = 2+1 and N{sub f} = 2+1+1 phase diagram indicates

Machine learning action parameters in lattice quantum chromodynamics

Science.gov (United States)

Shanahan, Phiala E.; Trewartha, Daniel; Detmold, William

2018-05-01

Numerical lattice quantum chromodynamics studies of the strong interaction are important in many aspects of particle and nuclear physics. Such studies require significant computing resources to undertake. A number of proposed methods promise improved efficiency of lattice calculations, and access to regions of parameter space that are currently computationally intractable, via multi-scale action-matching approaches that necessitate parametric regression of generated lattice datasets. The applicability of machine learning to this regression task is investigated, with deep neural networks found to provide an efficient solution even in cases where approaches such as principal component analysis fail. The high information content and complex symmetries inherent in lattice QCD datasets require custom neural network layers to be introduced and present opportunities for further development.

Cavity quantum chromodynamics in the presence of a classical background field

International Nuclear Information System (INIS)

Gavin, E.J.O.; Viollier, R.D.

1988-01-01

The QCD (quantum chromodynamics) Lagrange density is constructed in which the gluon field has a classical part, using the background field gauge. The conserved currents deriving from the symmetries of this theory are given and used to define boundary conditions on the field operators on the surface of a spherical, static cavity. The field operators are expanded in terms of a complete set of cavity modes that satisfy the boundary conditions and the field equations in the Dirac picture. 13 refs

The spin dependent structure function g1 of the deuteron and the proton

International Nuclear Information System (INIS)

Klostermann, L.

1995-01-01

This thesis presents a study on the spin structure of the nucleon, via deep inelastic scattering (DIS) of polarised nuons on polarised proton and deuterium targets. The work was done in the Spin Muon Collaboration (SMC) at CERN in Geneva. From the asymmetry in the scattering cross section for nucleon and lepton spins parallel and anti-parallel, one con determine the spin dependent structure function g 1 , which contains information on the quark and gluon spin distribution functions. The interpretation in the frame work of the quark parton model (QPM) of earlier results on g 1 p by the European Muon Collaboration (EMC), gave an indication that only a small fraction of the proton spin, compatible with zero, is carried by the spins of the constituent quarks. The SMC was set up to check this unexpected result with improved accuracy, and to combine measurements of g 1 p and g 1 d to test a fundamental sum rule in quantum chromodynamics (QCD), the Bjorken sum rule. (orig./WL)

Quantum electrical and chromodynamics treated through Thompson's approach

Energy Technology Data Exchange (ETDEWEB)

Nassif, Claudio [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mails: cnassifCBPF@yahoo.com.br; Silva, P.R. [Minas Gerais Univ. (UFMG), Belo Horizonte, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Fisica]. E-mail: prsilva@fisica.ufmg.br

2006-09-15

In this work we apply Thompson's method (of the dimensions and scales) to study some features of the Quantum Electro and Chromodynamics. This heuristic method can be considered as a simple and alternative way to the Renormalisation Group (R.G.) approach and when applied to QED-Lagrangian is able to obtain in a first approximation both the running coupling constant behavior of {alpha}({mu}) and the mass m({mu}). The calculations are evaluated just at d{sub c} = 4, where d{sub c} is the upper critical dimension of the problem, so that we obtain the logarithmic behavior both for the coupling {alpha} and the excess of mass {delta}m on the energy scale {mu}. Although our results are well-known in the vast literature of field theories, the advantage of Thompson's method, beyond its simplicity is that it is able to extract directly from QED-Lagrangian the physical (finite) behavior of {alpha}({mu}) and m({mu}), bypassing hard problems of divergences which normally appear in the conventional renormalisation schemes applied to field theories like QED. Quantum Chromodynamics (QCD) is also treated by the present method in order to obtain the quark condensate value. Besides this, the method is also able to evaluate the vacuum pressure at the boundary of the nucleon. This is done by assuming a step function behavior for the running coupling constant of the QCD, which fits nicely to some quantities related to the strong interaction evaluated through the MIT-bag model. (author)

Sum rules for multi-photon spectroscopy of ions in finite symmetry

International Nuclear Information System (INIS)

Kibler, M.; Daoud, M.

1993-05-01

Models describing one- and two-photon transitions for ions in crystalline environments are unified and extended to the case of parity-allowed and parity-forbidden p-photon transitions. The number of independent parameters for characterizing the polarization dependence is shown to depend on an ensemble of properties and rules which combine symmetry considerations and physical models. (author) 26 refs

Some views about chromodynamics; Quelques elements de chromodynamique

Energy Technology Data Exchange (ETDEWEB)

Pilon, E. [Ecole Nationale Superieure Agronomique, 31 - Toulouse (France)]|[Ecole Nationale Superieure, LAPP, 74 - Annecy-le-Vieux (France)

1995-12-31

The first lesson recalls some basis of quantum chromodynamics (QCD). Particularly the Lagrangian density and the Feynman laws are described. The second lesson presents the problem of renormalization and the notion of efficient coupling. The important property of asymptotic freedom of QCD is detailed. The third lesson gives a schematic classification of processes involved in hadronic physics with high energy-momentum transfer. Scale invariance and its breakdown by using leading log method is presented and leads to the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi equations. The fourth and last lesson paves the way to use the factorization method beyond the leading logs in the case of hadron-hadron collision within the frame of leading twist. Some ideas about comparisons between semi-analytical calculations and Monte-Carlo simulations are given. (A.C.) 55 refs.

Current-Current Interactions, Dynamical Symmetry - and Quantum Chromodynamics.

Science.gov (United States)

Neuenschwander, Dwight Edward, Jr.

Quantum Chromodynamics with massive gluons (gluon mass (TBOND) xm(,p)) in a contact-interaction limit called CQCD (strong coupling g (--->) (INFIN); x (--->) (INFIN)), despite its non-renormalizability and lack of hope of confinement, is nevertheless interesting for at least two reasons. (1) Some authors have suggested a relation between 4-Fermi and Yang-Mills theories. If g/x('2) slavery, perturbative evaluation of QCD in the infrared is a dubious practice. However, if g('2)/x('2) << 1 in CQCD, then the simplest 4-Fermi interaction is dominant, and CQCD admits perturbative treatment, but only in the infrared. With the dominant interaction, a dynamical Nambu-Goldstone realization of chiral symmetry -breaking (XSB) is found. Although in QCD the relation between confinement and XSB is controversial, XSB occurs in CQCD provided confinement is sacrificed.

Simple Finite Sums

KAUST Repository

Alabdulmohsin, Ibrahim M.

2018-01-01

We will begin our treatment of summability calculus by analyzing what will be referred to, throughout this book, as simple finite sums. Even though the results of this chapter are particular cases of the more general results presented in later chapters, they are important to start with for a few reasons. First, this chapter serves as an excellent introduction to what summability calculus can markedly accomplish. Second, simple finite sums are encountered more often and, hence, they deserve special treatment. Third, the results presented in this chapter for simple finite sums will, themselves, be used as building blocks for deriving the most general results in subsequent chapters. Among others, we establish that fractional finite sums are well-defined mathematical objects and show how various identities related to the Euler constant as well as the Riemann zeta function can actually be derived in an elementary manner using fractional finite sums.

Simple Finite Sums

KAUST Repository

Alabdulmohsin, Ibrahim M.

2018-03-07

We will begin our treatment of summability calculus by analyzing what will be referred to, throughout this book, as simple finite sums. Even though the results of this chapter are particular cases of the more general results presented in later chapters, they are important to start with for a few reasons. First, this chapter serves as an excellent introduction to what summability calculus can markedly accomplish. Second, simple finite sums are encountered more often and, hence, they deserve special treatment. Third, the results presented in this chapter for simple finite sums will, themselves, be used as building blocks for deriving the most general results in subsequent chapters. Among others, we establish that fractional finite sums are well-defined mathematical objects and show how various identities related to the Euler constant as well as the Riemann zeta function can actually be derived in an elementary manner using fractional finite sums.

Simulations of non-relativistic quantum chromodynamics at strong and weak coupling

Science.gov (United States)

Shakespeare, Norman Harold

In this thesis heavy quarks are investigated using lattice nonrelativistic quantum chromodynamics (NRQCD). Two major research works are presented. In the first major work, simulations are done for the three quarkonium systems cc¯, bc¯, and bb¯. The hyperfine splittings are computed at both leading and next-to-leading order in the relativistic expansion, using a large number of lattice spacings. A detailed comparison between mean-link and average plaquette tadpole renormalization schemes is undertaken with a number of features favouring the use of mean-links. These include much better scaling behavior of the hyperfine splittings and smaller relativistic corrections to the spin splittings. Signs of a breakdown in the NRQCD expansion are seen when the bare quark mass, in lattice units, falls below about one. In the second work, coefficients for the perturbative expansion of the static quark self energy are extracted from Monte Carlo simulations in the perturbative region of lattice quantum chromodynamics (QCD). A very large systematic study resulted in a major extension of existing methods. Twisted boundary conditions are used to eliminate the effects of zero modes and to suppress tunneling between the degenerate Z3 vacua. The Monte Carlo results are in excellent agreement with analytic perturbation theory, which is known through second order. New results for the third order coefficient are reported. Preliminary work is reported on quark propagators which will be used to measure second order mass renormalizations for NRQCD fermions.

Quarks, QCD [quantum chromodynamics] and the real world of experimental data

International Nuclear Information System (INIS)

Lipkin, H.J.

1987-07-01

The experimental evidence that supports quantum chromodynamics as the theory that describes how the quarks interact is briefly discussed. The indications of the existence of quarks are reviewed, and calculation of hadron masses is discussed. Additional evidence of hadron substructure as seen in the antiproton is reviewed. Arguments for the existence of color as the ''charge'' carried by quarks by which they interact are given. Hadron masses and the hyperfine interaction are presented, followed by more exotic quark systems and a study of multiquark systems. Weak interactions in the quark model are discussed

Phase transitions and flux distributions of SU(2) lattice gauge theory

International Nuclear Information System (INIS)

Peng, Yingcai.

1993-01-01

The strong interactions between quarks are believed to be described by Quantum Chromodynamics (QCD), which is a non-abelian SU(3) gauge theory. It is known that QCD undergoes a deconfining phase transition at very high temperatures, that is, at low temperatures QCD is in confined phase, at sufficient high temperatures it is in an unconfined phase. Also, quark confinement is believed to be due to string formation. In this dissertation the authors studied SU(2) gauge theory using numerical methods of LGT, which will provide some insights about the properties of QCD because SU(2) is similar to SU(3). They measured the flux distributions of a q bar q pair at various temperatures in different volumes. They find that in the limit of infinite volumes the flux distribution is different in the two phases. In the confined phase strong evidence is found for the string formation, however, in the unconfined phase there is no string formation. On the other hand, in the limit of zero temperature and finite volumes they find a clear signal for string formation in the large volume region, however, the string tension measured in intermediate volumes is due to finite volume effects, there is no intrinsic string formation. The color flux energies (action) of the q bar q pair are described by Michael sum rules. The original Michael sum rules deal with a static q bar q pair at zero temperature in infinite volumes. To check these sum rules with flux data at finite temperatures, they present a complete derivation for the sum rules, thus generalizing them to account for finite temperature effects. They find that the flux data are consistent with the prediction of generalized sum rules. The study elucidates the rich structures of QCD, and provides evidence for quark confinement and string formation. This supports the belief that QCD is a correct theory for strong interactions, and quark confinement can be explained by QCD

Expansion around half-integer values, binomial sums, and inverse binomial sums

International Nuclear Information System (INIS)

Weinzierl, Stefan

2004-01-01

I consider the expansion of transcendental functions in a small parameter around rational numbers. This includes in particular the expansion around half-integer values. I present algorithms which are suitable for an implementation within a symbolic computer algebra system. The method is an extension of the technique of nested sums. The algorithms allow in addition the evaluation of binomial sums, inverse binomial sums and generalizations thereof

A New Sum Analogous to Gauss Sums and Its Fourth Power Mean

Directory of Open Access Journals (Sweden)

Shaofeng Ru

2014-01-01

Full Text Available The main purpose of this paper is to use the analytic methods and the properties of Gauss sums to study the computational problem of one kind of new sum analogous to Gauss sums and give an interesting fourth power mean and a sharp upper bound estimate for it.

Solving quantum chromodynamics by discretized light-cone quantization

International Nuclear Information System (INIS)

Pauli, H.C.

1996-01-01

An effective theory for quantum chromodynamics (QCD) is derived analytically and nonperturbatively from the canonical Lagrangian for QCD in three space and one time dimension. The full light-cone QCD-Hamiltonian is mapped identically onto an effective Hamiltonian which acts only in the q anti q-space. A vertex coupling function is resumed to all orders and after renormalization should become the running coupling constant. The final equations are of surprizing simplicity, and are numerically solvable on a small computer. The prescription is given how to derive from these solutions the probability amplitudes for arbitrary gluon and quark-anti-quark composition by quadratures. The method is based on discretized light-cone quantization and the new method of iterated resolvents. The procedure is applicable also to other many-body theories, but the present work specializes to the general aspects of QCD. (orig.)

First observation of the splittings of the E1 p-wave amplitudes in low energy deuteron photodisintegration and its implications for the Gerasimov-Drell-Hearn Sum Rule integrand

International Nuclear Information System (INIS)

Blackston, M. A.; Ahmed, M. A.; Perdue, B. A.; Weller, H. R.; Bewer, B.; Pywell, R. E.; Wurtz, W. A.; Igarashi, R.; Kucuker, S.; Norum, B.; Wang, K.; Li, J.; Mikhailov, S. F.; Popov, V. G.; Wu, Y. K.; Sawatzky, B. D.

2008-01-01

Angular distributions of the cross section and linear analyzing powers have been measured for the d(γ-vector,n)p reaction at the High Intensity γ-ray Source with linearly polarized beams of 14 and 16 MeV. The outgoing neutrons were detected using the Blowfish detector array, consisting of 88 liquid scintillator detectors with large solid angle coverage. The amplitudes of the reduced transition matrix elements were extracted by means of fits to the data and good agreement was found with a recent potential model calculation of the splittings of the triplet p-wave amplitudes. The extracted amplitudes are used to reconstruct the Gerasimov-Drell-Hearn sum rule integrand for the deuteron and are compared to theory

Measuring the scale parameter of quantum chromodynamics at CHEER

International Nuclear Information System (INIS)

Krauss, L.M.

1981-01-01

The possibility of measuring the scale parameter of quantum chromodynamics, Λsub(s), at CHEER is discussed. Rationale for the measurement of this quantity are given, along with a discussion of the theoretical difficulties involved. The meaurement of the Q 2 dependence of structure functions and their moments, and methods of measuring αsub(s) and its Q 2 evolution, are discussed, and arguments are given for the advantages and disadvantages of going to high Q 2 values at CHEER. It is concluded that while sensitivity to Λ is lowered at high Q 2 , CHEER will, in principle, be able to provide the first clean measurements of Λ, free from almost all the theoretical confusion involved in interpretations of present data

Hadronic distributions and correlations at 'small x' in quantum chromodynamics

International Nuclear Information System (INIS)

Perez Ramos, R.

2006-09-01

We exactly calculate the double and simple inclusive transverse momentum (kt) distributions and the 2-particle momentum correlations inside high energy hadronic jets at the Modified Leading Logarithmic Approximation (MLLA) of Quantum Chromodynamics. We first obtain the exact solution of the evolution equations at 'small x', which we calculate at the so called 'limiting spectrum'. We then generalize this approximation by performing the steepest descent evaluation. Our predictions are in good agreement with data from Tevatron and improve those which have been obtained in the past. The comparison with forthcoming data (Tevatron, LHC) will further test the hypothesis of Local Hadron Parton Duality, and the eventual need to incorporate next-MLLA corrections. (authors)

Strong coupling 1/Nsub(c) expansion in the gluonic sector of lattice quantum chromodynamics

International Nuclear Information System (INIS)

Engels, J.; Montvay, I.

1980-01-01

The vacuum state of gluonic quantum chromodynamics on the lattice is determined up to fifth order in a 1/Nsub(c) expansion (Nsub(c) = number of colours). The vacuum expectation value of the gluon field squared Fsub(aμv)Fsub(a)sup(μv) is deduced. The quark-antiquark and gluon-gluon potential is calculated in the same limit up to the 1/N 3 sub(c) order. (orig.)

Decoupling of heavy quarks in quantum chromodynamics

International Nuclear Information System (INIS)

Bernreuther, W.

1983-01-01

Decoupling of heavy quarks in quantum chromodynamics (QCD) defined by mass-independent renormalization is investigated. The structure of the relations between the parameters of f flavour QCD below a heavy-quark threshold is discussed to all orders in the loop expansion, and the relations are computed to two-loop approximation for the minimal subtraction schemes (MS) and to one-loop approximation for some Weinberg schemes. These matching relations can be used to systematically determine the renormalization group (RG)-invariant parameters of the effective theory in terms of the RG-invariant parameters of the theory which includes the heavy quark, or vice versa. For MS scheme the connection between Λ/sub f/-1 and Λ/sub f/ to two and three loops is given as well as the two-loop connection between the RG-invariant mass parameters of the f-1 and f flavour theory. The effect of heavy quarks on the evolution of the QCQ coupling is of significance for present QCD phenomenology based on next-to-leading-order perturbation theory. This is illustrated with a few examples within the MS scheme

78 FR 48522 - Self-Regulatory Organizations; New York Stock Exchange LLC; Notice of Filing of Proposed Rule...

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2013-08-08

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Self-consistency and sum-rule tests in the Kramers-Kronig analysis of optical data: Applications to aluminum

International Nuclear Information System (INIS)

Shiles, E.; Sasaki, T.; Inokuti, M.; Smith, D.Y.

1980-01-01

An iterative, self-consistent procedure for the Kramers-Kronig analysis of data from reflectance, ellipsometric, transmission, and electron-energy-loss measurements is presented. This procedure has been developed for practical dispersion analysis since experimentally no single optical function can be readily measured over the entire range of frequencies as required by the Kramers-Kronig relations. The present technique is applied to metallic aluminum as an example. The results are then examined for internal consistency and for systematic errors by various optical sum rules. The present procedure affords a systematic means of preparing a self-consistent set of optical functions provided some optical or energy-loss data are available in all important spectral regions. The analysis of aluminum discloses that currently available data exhibit an excess oscillator strength, apparently in the vicinity of the L edge. A possible explanation is a systematic experimental error in the absorption-coefficient measurements resulting from surface layers: possibly oxides: present in thin-film transmission samples. A revised set of optical functions has been prepared by an ad hoc reduction of the reported absorption coefficient above the L edge by 14%. These revised data lead to a total oscillator strength consistent with the known electron density and are in agreement with dc-conductivity and stopping-power measurements as well as with absorption coefficients inferred from the cross sections of neighboring elements in the periodic table. The optical functions resulting from this study show evidence for both the redistribution of oscillator strength between energy levels and the effects on real transitions of the shielding of conduction electrons by virtual processes in the core states

Small parameters in infrared quantum chromodynamics

Science.gov (United States)

Peláez, Marcela; Reinosa, Urko; Serreau, Julien; Tissier, Matthieu; Wschebor, Nicolás

2017-12-01

We study the long-distance properties of quantum chromodynamics in the Landau gauge in an expansion in powers of the three-gluon, four-gluon, and ghost-gluon couplings, but without expanding in the quark-gluon coupling. This is motivated by two observations. First, the gauge sector is well described by perturbation theory in the context of a phenomenological model with a massive gluon. Second, the quark-gluon coupling is significantly larger than those in the gauge sector at large distances. In order to resum the contributions of the remaining infinite set of QED-like diagrams, we further expand the theory in 1 /Nc, where Nc is the number of colors. At leading order, this double expansion leads to the well-known rainbow approximation for the quark propagator. We take advantage of the systematic expansion to get a renormalization-group improvement of the rainbow resummation. A simple numerical solution of the resulting coupled set of equations reproduces the phenomenology of the spontaneous chiral symmetry breaking: for sufficiently large quark-gluon coupling constant, the constituent quark mass saturates when its valence mass approaches zero. We find very good agreement with lattice data for the scalar part of the propagator and explain why the vectorial part is poorly reproduced.

Selecting Sums in Arrays

DEFF Research Database (Denmark)

Brodal, Gerth Stølting; Jørgensen, Allan Grønlund

2008-01-01

In an array of n numbers each of the \\binomn2+nUnknown control sequence '\\binom' contiguous subarrays define a sum. In this paper we focus on algorithms for selecting and reporting maximal sums from an array of numbers. First, we consider the problem of reporting k subarrays inducing the k largest...... sums among all subarrays of length at least l and at most u. For this problem we design an optimal O(n + k) time algorithm. Secondly, we consider the problem of selecting a subarray storing the k’th largest sum. For this problem we prove a time bound of Θ(n · max {1,log(k/n)}) by describing...... an algorithm with this running time and by proving a matching lower bound. Finally, we combine the ideas and obtain an O(n· max {1,log(k/n)}) time algorithm that selects a subarray storing the k’th largest sum among all subarrays of length at least l and at most u....

Zero-Sum Flows in Designs

International Nuclear Information System (INIS)

Akbari, S.; Khosrovshahi, G.B.; Mofidi, A.

2010-07-01

Let D be a t-(v, k, λ) design and let N i (D), for 1 ≤ i ≤ t, be the higher incidence matrix of D, a (0, 1)-matrix of size (v/i) x b, where b is the number of blocks of D. A zero-sum flow of D is a nowhere-zero real vector in the null space of N 1 (D). A zero-sum k-flow of D is a zero-sum flow with values in {±,...,±(k-1)}. In this paper we show that every non-symmetric design admits an integral zero-sum flow, and consequently we conjecture that every non-symmetric design admits a zero-sum 5-flow. Similarly, the definition of zero-sum flow can be extended to N i (D), 1 ≤ i ≤ t. Let D = t-(v,k, (v-t/k-t)) be the complete design. We conjecture that N t (D) admits a zero-sum 3-flow and prove this conjecture for t = 2. (author)

Small sum privacy and large sum utility in data publishing.

Science.gov (United States)

Fu, Ada Wai-Chee; Wang, Ke; Wong, Raymond Chi-Wing; Wang, Jia; Jiang, Minhao

2014-08-01

While the study of privacy preserving data publishing has drawn a lot of interest, some recent work has shown that existing mechanisms do not limit all inferences about individuals. This paper is a positive note in response to this finding. We point out that not all inference attacks should be countered, in contrast to all existing works known to us, and based on this we propose a model called SPLU. This model protects sensitive information, by which we refer to answers for aggregate queries with small sums, while queries with large sums are answered with higher accuracy. Using SPLU, we introduce a sanitization algorithm to protect data while maintaining high data utility for queries with large sums. Empirical results show that our method behaves as desired. Copyright © 2014 Elsevier Inc. All rights reserved.

The Spin Structure of ³He and the Neutron at Low Q²: A Measurement of the Generalized GDH Integrand

Energy Technology Data Exchange (ETDEWEB)

Sulkosky, Vincent [College of William and Mary, Williamsburg, VA (United States)

2007-08-01

Since the 1980's, the study of nucleon (proton or neutron) spin structure has been an active field both experimentally and theoretically. One of the primary goals of this work is to test our understanding of Quantum Chromodynamics (QCD), the fundamental theory of the strong interaction. In the high energy region of asymptotically free quarks, QCD has been verified. However, verifiable predictions in the low energy region are harder to obtain due to the complex interactions between the nucleon's constituents: quarks and gluons. In the non-pertubative regime, low-energy effective field theories such as chiral perturbation theory provide predictions for the spin structure functions in the form of sum rules. Spin-dependent sum rules such as the Gerasimov-Drell-Hearn (GDH) sum rule are important tools available to study nucleon spin structure. Originally derived for real photon absorption, the Gerasimov-Drell-Hearn (GDH) sum rule was first extended for virtual photon absorption in 1989. The extension of the sum rule provides a unique relation, valid at any momentum transfer ($Q^{2}$), that can be used to study the nucleon spin structure and make comparisons between theoretical predictions and experimental data. Experiment E97-110 was performed at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) to examine the spin structure of the neutron and $^{3}$He. The Jefferson Lab longitudinally-polarized electron beam with incident energies between 1.1 and 4.4 GeV was scattered from a longitudinally or transversely polarized $^{3}$He gas target in the Hall A end station. Asymmetries and polarized cross-section differences were measured in the quasielastic and resonance regions to extract the spin structure functions $g_{1}(x,Q^{2})$ and $g_{2}(x,Q^{2})$ at low momentum transfers (0.02 $< Q^{2} <$ 0.3 GeV$^{2}$). The goal of the experiment was to perform a precise measurement of the $Q^{2}$ dependence of the extended GDH integral and of the moments of

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Parton densities in quantum chromodynamics. Gauge invariance, path-dependence, and Wilson lines

International Nuclear Information System (INIS)

Cherednikov, Igor O.

2017-01-01

The purpose of this book is to give a systematic pedagogical exposition of the quantitative analysis of Wilson lines and gauge-invariant correlation functions in quantum chromodynamics. Using techniques from the previous volume (Wilson Lines in Quantum Field Theory, 2014), an ab initio methodology is developed and practical tools for its implementation are presented. Emphasis is put on the implications of gauge invariance and path-dependence properties of transverse-momentum dependent parton density functions. The latter are associated with the QCD factorization approach to semi-inclusive hadronic processes, studied at currently operating and planned experimental facilities.

Parton densities in quantum chromodynamics. Gauge invariance, path-dependence, and Wilson lines

Energy Technology Data Exchange (ETDEWEB)

Cherednikov, Igor O. [Antwerpen Univ. (Belgium). Dept. Fysica; Veken, Frederik F. van der [CERN, Geneva (Switzerland)

2017-05-01

The purpose of this book is to give a systematic pedagogical exposition of the quantitative analysis of Wilson lines and gauge-invariant correlation functions in quantum chromodynamics. Using techniques from the previous volume (Wilson Lines in Quantum Field Theory, 2014), an ab initio methodology is developed and practical tools for its implementation are presented. Emphasis is put on the implications of gauge invariance and path-dependence properties of transverse-momentum dependent parton density functions. The latter are associated with the QCD factorization approach to semi-inclusive hadronic processes, studied at currently operating and planned experimental facilities.

Mutation rules and the evolution of sparseness and modularity in biological systems.

Directory of Open Access Journals (Sweden)

Tamar Friedlander

Full Text Available Biological systems exhibit two structural features on many levels of organization: sparseness, in which only a small fraction of possible interactions between components actually occur; and modularity--the near decomposability of the system into modules with distinct functionality. Recent work suggests that modularity can evolve in a variety of circumstances, including goals that vary in time such that they share the same subgoals (modularly varying goals, or when connections are costly. Here, we studied the origin of modularity and sparseness focusing on the nature of the mutation process, rather than on connection cost or variations in the goal. We use simulations of evolution with different mutation rules. We found that commonly used sum-rule mutations, in which interactions are mutated by adding random numbers, do not lead to modularity or sparseness except for in special situations. In contrast, product-rule mutations in which interactions are mutated by multiplying by random numbers--a better model for the effects of biological mutations--led to sparseness naturally. When the goals of evolution are modular, in the sense that specific groups of inputs affect specific groups of outputs, product-rule mutations also lead to modular structure; sum-rule mutations do not. Product-rule mutations generate sparseness and modularity because they tend to reduce interactions, and to keep small interaction terms small.

Local-duality QCD sum rules for strong isospin breaking in the decay constants of heavy-light mesons

Energy Technology Data Exchange (ETDEWEB)

Lucha, Wolfgang [Austrian Academy of Sciences, Institute for High Energy Physics, Vienna (Austria); Melikhov, Dmitri [Austrian Academy of Sciences, Institute for High Energy Physics, Vienna (Austria); M.V. Lomonosov Moscow State University, D.V. Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); University of Vienna, Faculty of Physics, Vienna (Austria); Simula, Silvano [Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tre, Rome (Italy)

2018-02-15

We discuss the leptonic decay constants of heavy-light mesons by means of Borel QCD sum rules in the local-duality (LD) limit of infinitely large Borel mass parameter. In this limit, for an appropriate choice of the invariant structures in the QCD correlation functions, all vacuum-condensate contributions vanish and all nonperturbative effects are contained in only one quantity, the effective threshold. We study properties of the LD effective thresholds in the limits of large heavy-quark mass m{sub Q} and small light-quark mass m{sub q}. In the heavy-quark limit, we clarify the role played by the radiative corrections in the effective threshold for reproducing the pQCD expansion of the decay constants of pseudoscalar and vector mesons. We show that the dependence of the meson decay constants on m{sub q} arises predominantly (at the level of 70-80%) from the calculable m{sub q}-dependence of the perturbative spectral densities. Making use of the lattice QCD results for the decay constants of nonstrange and strange pseudoscalar and vector heavy mesons, we obtain solid predictions for the decay constants of heavy-light mesons as functions of m{sub q} in the range from a few to 100 MeV and evaluate the corresponding strong isospin-breaking effects: f{sub D{sup +}} - f{sub D{sup 0}} = (0.96 ± 0.09) MeV, f{sub D}{sup {sub *}{sub +}} - f{sub D}{sup {sub *}{sub 0}} = (1.18 ± 0.35) MeV, f{sub B{sup 0}} - f{sub B{sup +}} = (1.01 ± 0.10) MeV, f{sub B}{sup {sub *}{sub 0}} - f{sub B}{sup {sub *}{sub +}} = (0.89 ± 0.30) MeV. (orig.)

Born’s rule as signature of a superclassical current algebra

International Nuclear Information System (INIS)

Fussy, S.; Mesa Pascasio, J.; Schwabl, H.; Grössing, G.

2014-01-01

We present a new tool for calculating the interference patterns and particle trajectories of a double-, three- and N-slit system on the basis of an emergent sub-quantum theory developed by our group throughout the last years. The quantum itself is considered as an emergent system representing an off-equilibrium steady state oscillation maintained by a constant throughput of energy provided by a classical zero-point energy field. We introduce the concept of a “relational causality” which allows for evaluating structural interdependences of different systems levels, i.e. in our case of the relations between partial and total probability density currents, respectively. Combined with the application of 21st century classical physics like, e.g., modern nonequilibrium thermodynamics, we thus arrive at a “superclassical” theory. Within this framework, the proposed current algebra directly leads to a new formulation of the guiding equation which is equivalent to the original one of the de Broglie–Bohm theory. By proving the absence of third order interferences in three-path systems it is shown that Born’s rule is a natural consequence of our theory. Considering the series of one-, double-, or, generally, of N-slit systems, with the first appearance of an interference term in the double slit case, we can explain the violation of Sorkin’s first order sum rule, just as the validity of all higher order sum rules. Moreover, the Talbot patterns and Talbot distance for an arbitrary N-slit device can be reproduced exactly by our model without any quantum physics tool. -- Highlights: •Calculating the interference patterns and particle trajectories of a double-, three- and N-slit system. •Deriving a new formulation of the guiding equation equivalent to the de Broglie–Bohm one. •Proving the absence of third order interferences and thus explaining Born’s rule. •Explaining the violation of Sorkin’s order sum rules. •Classical simulation of Talbot patterns