Measurement of the pion form factor at BESIII in the rho-peak region relevant for (g — 2)μ
Redmer, C. F.; BESIII Collaboration
2016-11-01
Measurements of hadronic cross sections in e+e- collisions are an important input for the Standard Model calculations of the hadronic contribution to the anomalous magnetic moment of the muon, (g — 2)μ. We present a new measurement of the cross section e+e- → π+π-, the pion form factor, which dominates the hadronic contribution. Using the method of initial state radiation, 2.93 fb-1 of data taken with the BESIII detector at the ψ (3770) peak have been evaluated to determine the cross section in the energy range between 600 and 900 MeV with a systematic uncertainty of 0.9%. The new BESIII data are compared to previous measurements by KLOE and BaBar, and their impact on (g — 2)μ is discussed.
Frederic D. R. Bonnet; Robert G. Edwards; George T. Fleming; Randal Lewis; David Richards
2003-07-22
We have started a program to compute the electromagnetic form factors of mesons. We discuss the techniques used to compute the pion form factor and present preliminary results computed with domain wall valence fermions on MILC asqtad lattices, as well as Wilson fermions on quenched lattices. These methods can easily be extended to rho-to-gamma-pi transition form factors.
Kubis, B; Meißner, Ulf G; Mei{\\ss}ner, Ulf-G.
1999-01-01
We calculate the form factors of the baryon octet in the framework of heavy baryon chiral perturbation theory. The calculated charge radius of the show that kaon loop effects can play a significant role in the neutron electric form factor. Furthermore. we derive generalized Caldi-Pagels relations between various charge radii which are free of chiral loop effects.
Amo Sanchez, del P.; Raven, H.G.; Snoek, H.; BaBar, Collaboration
2011-01-01
eta((')) transition form factors in the momentum-transfer range from 4 to 40 GeV(2). The analysis is based on 469 fb(-1) of integrated luminosity collected at PEP-II with the BABAR detector at e(+)e(-) center-of-mass energies near 10.6 GeV.
Happiness: origins, forms, and technical relevance.
Akhtar, Salman
2010-09-01
By critically reviewing Freud's views on happiness, and also those of Helene Deutsch, Bertram Lewin, Melanie Klein, and Heinz Kohut, the author evolves a complex and multilayered perspective on the phenomenon. He categorizes happiness into four related and occasionally overlapping varieties: pleasure-based happiness (elation), assertion-based happiness (joy), merger-based happiness (ecstasy), and fulfillment-based happiness (contentment). After entering some caveats and drawing from his clinical experience, the author then demonstrates the relevance of these ideas to the conduct of psychotherapy and psychoanalysis.
Nucleon Electromagnetic Form Factors
Kees de Jager
2004-08-01
Although nucleons account for nearly all the visible mass in the universe, they have a complicated structure that is still incompletely understood. The first indication that nucleons have an internal structure, was the measurement of the proton magnetic moment by Frisch and Stern (1933) which revealed a large deviation from the value expected for a point-like Dirac particle. The investigation of the spatial structure of the nucleon, resulting in the first quantitative measurement of the proton charge radius, was initiated by the HEPL (Stanford) experiments in the 1950s, for which Hofstadter was awarded the 1961 Nobel prize. The first indication of a non-zero neutron charge distribution was obtained by scattering thermal neutrons off atomic electrons. The recent revival of its experimental study through the operational implementation of novel instrumentation has instigated a strong theoretical interest. Nucleon electro-magnetic form factors (EMFFs) are optimally studied through the exchange of a virtual photon, in elastic electron-nucleon scattering. The momentum transferred to the nucleon by the virtual photon can be selected to probe different scales of the nucleon, from integral properties such as the charge radius to scaling properties of its internal constituents. Polarization instrumentation, polarized beams and targets, and the measurement of the polarization of the recoiling nucleon have been essential in the accurate separation of the charge and magnetic form factors and in studies of the elusive neutron charge form factor.
Ryong Ji, C.; Pang, A.; Szczepaniak, A. [North Carolina State Univ., Raleigh, NC (United States)
1994-04-01
It is pointed out that the correct criterion to define the legal PQCD contribution to the exclusive processes in the lightcone perturbative expansion should be based on the large off-shellness of the lightcone energy in the intermediate states. In the lightcone perturbative QCD calculation of the pion form factor, the authors find that the legal PQCD contribution defined by the lightcone energy cut saturates in the smaller Q{sup 2} region compared to that defined by the gluon four-momentum square cut. This is due to the contribution by the highly off-energy-shell gluons in the end point regions of the phase space, indicating that the gluon four-momentum-square cut may have cut too much to define the legal PQCD.
Nucleon Electromagnetic Form Factors
Marc Vanderhaeghen; Charles Perdrisat; Vina Punjabi
2007-10-01
There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has greatly improved by performing double polarization experiments, in comparison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at JLab, MAMI, and MIT-Bates. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed, including the recent progress in the determination of the valence quark generalized parton distributions of the nucleon, as well as the steady rate of improvements made in the lattice QCD calculations.
Maas, F. E.; Paschke, K. D.
2017-07-01
A broad program measuring parity-violation in electron-nuclear scattering has now provided a large set of precision data on the weak-neutral-current form-factors of the proton. Under comparison with well-measured electromagnetic nucleon form-factors, these measurements reveal the role of the strange quark sea on the low-energy interactions of the proton through the strange-quark-flavor vector form-factors. This review will describe the experimental program and the implications of the global data for the strange-quark vector form-factors. We present here a new fit to the world data.
Functional dyspepsia: Are psychosocial factors of relevance?
Sandra Barry; Timothy G Dinan
2006-01-01
The pathogenesis of Functional Dyspepsia (FD) remains unclear, appears diverse and is thus inadequately understood. Akin to other functional gastrointestinal disorders, research has demonstrated an association between this common diagnosis and psychosocial factors and psychiatric morbidity. Conceptualising the relevance of these factors within the syndrome of FD requires application of the biopsychosocial model of disease.Using this paradigm, dysregulation of the reciprocal communication between the brain and the gut is central to symptom generation, interpretation and exacerbation.Appreciation and understanding of the neurobiological correlates of various psychological states is also relevant.The view that psychosocial factors exert their influence in FD predominantly through motivation of health care seeking also persists. This appears too one-dimensional an assertion in light of the evidence available supporting a more intrinsic aetiological link. Evolving understanding of pathogenic mechanisms and the heterogeneous nature of the syndrome will facilitate effective management.Co-morbid psychiatric illness warrants treatment with conventional therapies. Acknowledging the relevance of psychosocial variables in FD, the degree of which is subject to variation, has implications for assessment and management. Available evidence suggests psychological therapies may benefit FD patients particularly those with chronic symptoms. The rationale for use of psychotropic medications in FD is apparent but the evidence base to support the use of antidepressant pharmacotherapy is to date limited.
TRASYS form factor matrix normalization
Tsuyuki, Glenn T.
1992-01-01
A method has been developed for adjusting a TRASYS enclosure form factor matrix to unity. This approach is not limited to closed geometries, and in fact, it is primarily intended for use with open geometries. The purpose of this approach is to prevent optimistic form factors to space. In this method, nodal form factor sums are calculated within 0.05 of unity using TRASYS, although deviations as large as 0.10 may be acceptable, and then, a process is employed to distribute the difference amongst the nodes. A specific example has been analyzed with this method, and a comparison was performed with a standard approach for calculating radiation conductors. In this comparison, hot and cold case temperatures were determined. Exterior nodes exhibited temperature differences as large as 7 C and 3 C for the hot and cold cases, respectively when compared with the standard approach, while interior nodes demonstrated temperature differences from 0 C to 5 C. These results indicate that temperature predictions can be artificially biased if the form factor computation error is lumped into the individual form factors to space.
$K_{13}$ transition form factors
Chueng Ryong Ji
2001-01-01
The rainbow truncation of the quark Dyson-Schwinger equation is combined with the ladder Bethe-Salpeter equation for the meson bound state amplitudes and the dressed quark-W vertex in a manifestly covariant calculation of the K/sub l3/ transition form factors and decay width in the impulse approximation. With model gluon parameters previously fixed by the chiral condensate, the pion mass and decay constant, and the kaon mass, our results for the K/sub l3/ form factors and the kaon semileptonic decay width are in good agreement with the experimental data. (37 refs).
Baryon Form Factors at Threshold
Baldini Ferroli, Rinaldo [Museo Storico della Fisica e Centro Studi e Ricerche ' E. Fermi' , Rome (Italy); INFN, Laboratori Nazionali di Frascati, Frascati (Italy); Pacetti, Simone [INFN and Dipartimento di Fisica, Universita di Perugia, Perugia (Italy)
2012-04-15
An extensive study of the e{sup +}e{sup -}{yields}pp{sup Macron }BABAR cross section data is presented. Two unexpected outcomes have been found: the modulus of the proton form factor is normalized to one at threshold, i.e.: |G{sup p}(4M{sub p}{sup 2})|=1, as a pointlike fermion, and the resummation factor in the Sommerfeld formula is not needed. Other e{sup +}e{sup -} {yields} baryon-antibaryon cross sections show a similar behavior near threshold.
Environmental Factors Impacting Bone-Relevant Chemokines
Smith, Justin T.; Schneider, Andrew D.; Katchko, Karina M.; Yun, Chawon; Hsu, Erin L.
2017-01-01
Chemokines play an important role in normal bone physiology and the pathophysiology of many bone diseases. The recent increased focus on the individual roles of this class of proteins in the context of bone has shown that members of the two major chemokine subfamilies—CC and CXC—support or promote the formation of new bone and the remodeling of existing bone in response to a myriad of stimuli. These chemotactic molecules are crucial in orchestrating appropriate cellular homing, osteoblastogenesis, and osteoclastogenesis during normal bone repair. Bone healing is a complex cascade of carefully regulated processes, including inflammation, progenitor cell recruitment, differentiation, and remodeling. The extensive role of chemokines in these processes and the known links between environmental contaminants and chemokine expression/activity leaves ample opportunity for disruption of bone healing by environmental factors. However, despite increased clinical awareness, the potential impact of many of these environmental factors on bone-related chemokines is still ill defined. A great deal of focus has been placed on environmental exposure to various endocrine disruptors (bisphenol A, phthalate esters, etc.), volatile organic compounds, dioxins, and heavy metals, though mainly in other tissues. Awareness of the impact of other less well-studied bone toxicants, such as fluoride, mold and fungal toxins, asbestos, and chlorine, is also reviewed. In many cases, the literature on these toxins in osteogenic models is lacking. However, research focused on their effects in other tissues and cell lines provides clues for where future resources could be best utilized. This review aims to serve as a current and exhaustive resource detailing the known links between several classes of high-interest environmental pollutants and their interaction with the chemokines relevant to bone healing. PMID:28261155
Strange chiral nucleon form factors
Hemmert, T R; Meißner, Ulf G; Hemmert, Thomas R.; Kubis, Bastian; Meissner, Ulf-G.
1999-01-01
We investigate the strange electric and magnetic form factors of the nucleon in the framework of heavy baryon chiral perturbation theory to third order in the chiral expansion. All counterterms can be fixed from data. In particular, the two unknown singlet couplings can be deduced from the parity-violating electron scattering experiments performed by the SAMPLE and the HAPPEX collaborations. Within the given uncertainties, our analysis leads to a small and positive electric strangeness radius, $ = (0.05 \\pm 0.16) fm^2$. We also deduce the consequences for the upcoming MAMI A4 experiment.
Pion and Kaon Electromagnetic Form Factors
Bijnens, J; Bijnens, Johan; Talavera, Pere
2002-01-01
We study the electromagnetic form factor of the pion and kaons at low-energies with the use of Chiral Perturbation Theory. The analysis is performed within the three flavour framework and at next-to-next-to-leading order. We explain carefully all the relevant consistency checks on the expressions, present full analytical results for the pion form factor and describe all the assumptions in the analysis. From the phenomenological point of view we make use of our expression and the available data to obtain the charge radius of the pion obtaining $_V^\\pi=(0.452+-0.013) fm^2$, as well as the low-energy constant $L_9^r(m_\\rho)= (5.93+-0.43)10^{-3}$. We also obtain experimental values for 3 combinations of order $p^6$ constants.
28 CFR 51.57 - Relevant factors.
2010-07-01
... THE VOTING RIGHTS ACT OF 1965, AS AMENDED Determinations by the Attorney General § 51.57 Relevant... afforded members of racial and language minority groups an opportunity to participate in the decision to... language minority groups into account in making the change....
Major congenital defects. Relevant risk factors. Cienfuegos. 2000-2005.
Vivian Vázquez Martínez
2008-04-01
Full Text Available Background: Major congenital defects have an impact on perinatal mortality and morbidity with economic and social consequences. Objective: To determine the relevant risk factors linked to the occurrence of congenital defects in Cienfuegos between 2000 and 2005. Methods: A case-control study was carried out. Women with fetus or newborns with major congenital defects formed the case group (255 while the control group consisted of a similar number of healthy children selected each year by a randomized simple sample. The variables gathered by the Cuban Congenital Defects Records were studied. Chi-Square method was used with 95% of accuracy and a reliance rate of 95%; logistic regression was used with the Wald test. Results: There was a predominance of Central Nervous System defects (28, 6%. The most relevant risk factors were a history of congenital defects, smoking habits, and acute infection during the first three months, as well as belong to the third birth on. Conclusion: The most clinical relevant risks factors were the congenital defect history and the acute infection during the firs three months.
Mycobacterial factors relevant for transmission of tuberculosis
Verhagen, L.M.; Hof, S. van den; Deutekom, H. van; Hermans, P.W.M.; Kremer, K.; Borgdorff, M.W.; Soolingen, D. van
2011-01-01
BACKGROUND: Tuberculosis (TB) transmission is associated with patient-related risk factors. However, DNA fingerprint analysis has provided anecdotal evidence suggesting a role for bacteriological factors. METHODS: To examine the importance of the bacteriological component in TB transmission, we inve
Form factors of charged hadrons and quantum chromodynamics
Saleem, M.; Fazal-e-Aleem; Rashid, H.; Azhar, I.A.; Rafique, M.
1988-07-01
A new parametrization G/sup New//sub p/ of the proton form factor is proposed. It is shown that this and the conventional parametrization G/sup V//sub ..pi../ = (1-t/m/sup 2//sub p/)/sup -1/ of the pion form factor are consistent with the experimental data wherever available, with lattice-QCD-based computations for small -t, and with perturbative QCD calculations for large -t. The hyperon form factors computed by using lattice QCD are also parametrized. The features of these form factors most relevant to the Chou-Yang Model are also discussed.
Definitions of relevent efficiency and stress factors
Wahlgren, U.
1981-03-01
A general efficiency function and related stress factors are defined from energy flow considerations. The efficiency function, or index, is related to maximum energy utilization, and stress is defined as total derivatives of the efficiency function. The efficiency function can be expressed, for an aquatic ecosystem, in terms of incident radiation, total production, total growth and the outflow at the highest trophical level. It is shown that the efficiency in principle can be measured for a lake from oxygen balance and hydrological conciderations. Changes in the efficiency are intimately connected with the activity at the primary level, which contributes most of the biomass and the production in the system. Perturbations on other levels effects the total system more indirectly, and this is the reason for using total rather than partial derivatives in the stress definitions. The behaviour of the efficiency function is demonstrated for a three-level Lotka-Volterra-type model with competition.(author).
Holography, chiral Lagrangian and form factor relations
Zuo, Fen
2013-01-01
We perform a detailed study of mesonic properties in a class of holographic models of QCD, which is described by the Yang-Mills plus Chern-Simons action. By decomposing the 5 dimensional gauge field into resonances and integrating out the massive ones, we reproduce the Chiral Perturbative Theory Lagrangian up to ${\\cal O}(p^6)$ and obtain all the relevant low energy constants (LECs). The numerical predictions of the LECs show minor model dependence, and agree reasonably with the determinations from other approaches. Interestingly, various model-independent relations appear among them. Some of these relations are found to be the large-distance limits of universal relations between form factors of the anomalous and even-parity sectors of QCD.
Factors Affecting the Value Relevance of Accounting Information
Mahmoud Dehghan Nayeri; Ali Faal Ghayoumi; Mohammad Ali Bidari
2012-01-01
The present study examines the factors affecting the value relevance of accounting information for investors in the Tehran Stock Exchange over the period of six years. In this study, the effect of four factors; being profitable or loss generating, company size, earnings stability and company growth on the value relevance of accounting information have been studied. For this purpose Ohlson model and the cumulative regression analysis is used in order to examine the hypotheses and as the basis ...
Soliton form factors from lattice simulations
Rajantie, Arttu
2010-01-01
The form factor provides a convenient way to describe properties of topological solitons in the full quantum theory, when semiclassical concepts are not applicable. It is demonstrated that the form factor can be calculated numerically using lattice Monte Carlo simulations. The approach is very general and can be applied to essentially any type of soliton. The technique is illustrated by calculating the kink form factor near the critical point in 1+1-dimensional scalar field theory. As expected from universality arguments, the result agrees with the exactly calculable scaling form factor of the two-dimensional Ising model.
Octet baryon electromagnetic form factors in nuclear medium
Ramalho, G; Thomas, A W
2012-01-01
We study the octet baryon electromagnetic form factors in nuclear matter using the covariant spectator quark model extended to the nuclear matter regime. The parameters of the model in vacuum are fixed by the study of the octet baryon electromagnetic form factors. In nuclear matter the changes in hadron properties are calculated by including the relevant hadron masses and the modification of the pion-baryon coupling constants calculated in the quark-meson coupling model. In nuclear matter the magnetic form factors of the octet baryons are enhanced in the low $Q^2$ region, while the electric form factors show a more rapid variation with $Q^2$. The results are compared with the modification of the bound proton electromagnetic form factors observed at Jefferson Lab. In addition, the corresponding changes for the bound neutron are predicted.
Charge-symmetry-breaking nucleon form factors
Kubis, Bastian
2009-01-01
A quantitative understanding of charge-symmetry breaking is an increasingly important ingredient for the extraction of the nucleon's strange vector form factors. We review the theoretical understanding of the charge-symmetry-breaking form factors, both for single nucleons and for Helium-4.
Calculation of Nucleon Electromagnetic Form Factors
Renner, D B; Dolgov, D S; Eicker, N; Lippert, T; Negele, J W; Pochinsky, A V; Schilling, K; Lippert, Th.
2002-01-01
The fomalism is developed to express nucleon matrix elements of the electromagnetic current in terms of form factors consistent with the translational, rotational, and parity symmetries of a cubic lattice. We calculate the number of these form factors and show how appropriate linear combinations approach the continuum limit.
Form Factors in radiative pion decay
Mateu, V
2007-01-01
We perform an analysis of the form factors that rule the structure-dependent amplitude in the radiative pion decay. The resonance contributions to pion -> e nu_e gamma decays are computed through the proper construction of the vector and axial-vector form factors by setting the QCD driven asymptotic properties of the three-point Green functions VVP and VAP, and by demanding the smoothing of the form factors at high transfer of momentum. A comparison between theoretical and experimental determinations of the form factors is also carried out. We also consider and evaluate the role played by a non-standard tensor form factor. We conclude that, at present and due to the hadronic incertitudes, the search for New Physics in this process is not feasible.
Separation energy dependence of hole form factors
Van de Wiele, J.; Langevin-Joliot, H. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Vdovin, A. [Joint Inst. for Nuclear Research, Dubna (Russian Federation). Bogoliubov Lab. of Theoretical Physics
1996-04-01
Form factors of fragmented hole states are studied within the quasiparticle-phonon model, using the inhomogeneous equation method. A systematic investigation of form factors is performed for neutron and proton hole states in the valence and first inner shells of {sup 208}Pb. Average characteristics are introduced for groups of levels, namely the mean form factors, summed source terms and correction potentials, and their behaviour is presented. The role of the relative values of the interaction radius parameter and binding well radius is discussed in details. (K.A.). 21 refs.; Submitted to Elsevier Science.
Wall, Nathalie A. [Washington State Univ., Pullman, WA (United States); Neeway, James J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Qafoku, Nikolla P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ryan, Joseph V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2015-09-30
Assessments of waste form and disposal options start with the degradation of the waste forms and consequent mobilization of radionuclides. Long-term static tests, single-pass flow-through tests, and the pressurized unsaturated flow test are often employed to study the durability of potential waste forms and to help create models that predict their durability throughout the lifespan of the disposal site. These tests involve the corrosion of the material in the presence of various leachants, with different experimental designs yielding desired information about the behavior of the material. Though these tests have proved instrumental in elucidating various mechanisms responsible for material corrosion, the chemical environment to which the material is subject is often not representative of a potential radioactive waste repository where factors such as pH and leachant composition will be controlled by the near-field environment. Near-field materials include, but are not limited to, the original engineered barriers, their resulting corrosion products, backfill materials, and the natural host rock. For an accurate performance assessment of a nuclear waste repository, realistic waste corrosion experimental data ought to be modeled to allow for a better understanding of waste form corrosion mechanisms and the effect of immediate geochemical environment on these mechanisms. Additionally, the migration of radionuclides in the resulting chemical environment during and after waste form corrosion must be quantified and mechanisms responsible for migrations understood. The goal of this research was to understand the mechanisms responsible for waste form corrosion in the presence of relevant repository sediments to allow for accurate radionuclide migration quantifications. The rationale for this work is that a better understanding of waste form corrosion in relevant systems will enable increased reliance on waste form performance in repository environments and potentially
Nucleon axial form factors from two-flavour Lattice QCD
Junnarkar, P M; Djukanovic, D; von Hippel, G; Hua, J; Jäger, B; Meyer, H B; Rae, T D; Wittig, H
2014-01-01
We present preliminary results on the axial form factor $G_A(Q^2)$ and the induced pseudoscalar form factor $G_P(Q^2)$ of the nucleon. A systematic analysis of the excited-state contributions to form factors is performed on the CLS ensemble `N6' with $m_\\pi = 340 \\ \\text{MeV}$ and lattice spacing $a \\sim 0.05 \\ \\text{fm}$. The relevant three-point functions were computed with source-sink separations ranging from $t_s \\sim 0.6 \\ \\text{fm}$ to $t_s \\sim \\ 1.4 \\ \\text{fm}$. We observe that the form factors suffer from non-trivial excited-state contributions at the source-sink separations available to us. It is noted that naive plateau fits underestimate the excited-state contributions and that the method of summed operator insertions correctly accounts for these effects.
Pseudoscalar meson form factors and decays
Dorokhov, A E
2011-01-01
In this communication we discuss few topics related with modern experimental data on the physics of light pseudoscalar mesons. It includes the contribution of the pseudoscalar mesons to the muon anomalous magnetic moment (AMM), $g-2$, the rare decays of light pseudoscalar mesons to lepton pair, the transition form factors of pseudoscalar mesons at large momentum transfer, the pion transversity form factor. Measuring the muon anomalous magnetic moment $g-2$ and the rare decays of light pseudoscalar mesons into lepton pair $P\\rightarrow l^{+}l^{-} $ serve as important test of the standard model. To reduce the theoretical uncertainty in the standard model predictions the data on the transition form factors of light pseudoscalar mesons play significant role. Recently new data on behavior of these form factors at large momentum transfer was supplied by the BABAR collaboration. Within the nonlocal chiral quark model it shown how to describe these data and how the meson distribution amplitude evolves as a function o...
Separation energy dependence of hole form factors
Van de Wiele, J. [Institut de Physique Nucleaire, 91 - Orsay (France); Vdovin, A. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Langevin-Joliot, H. [Institut de Physique Nucleaire, 91 - Orsay (France)
1996-08-05
Form factors of fragmented hole states are studied within the quasiparticle-phonon model, using the inhomogeneous equation method. The validity of this method is successfully checked by comparison with coupled equation solutions in schematic vibrational model cases. A systematic investigation of form factors is performed for neutron and proton hole states in the valence and first inner shells of {sup 208}Pb. Large fluctuations of form factor radii are observed for individual levels superimposed on a general increase with separation energy. Average characteristics are introduced for groups of levels, namely the mean form factors, summed source terms and correction potentials, and their behaviour is presented. The role of the relative values of the interaction radius parameter and binding well radius is discussed in detail. (orig.).
Electromagnetic Form Factors of the Nucleon
Bijker, R
1997-01-01
We reanalyze the world data on the electromagnetic form factors of the nucleon. The calculations are performed in the framework of an algebraic model of the nucleon combined with vector meson dominance.
Make Projects Small Form Factor PCs
Wessels, Duane
2006-01-01
Shoebox sized and smaller, small-form-factor PCs can pack as much computing muscle as a full-sized desktop computer. They consumer less power, have few or no moving parts, and are very quiet. Whether you plan to use one as a standalone PC or want to embed it in your next hacking project, a small-form-factor PC can be a lot of fun to build. Make Projects: Small Form Factor PCs is the only book available that shows you how to build small-form-factor PCs -- from kits and from scratch -- that are more interesting and more personalized than what a full-sized PC can give you. Included in the book
An Algebraic Approach to Form Factors
Niedermaier, M. R.
1994-01-01
An associative $*$-algebra is introduced (containing a $TTR$-algebra as a subalgebra) that implements the form factor axioms, and hence indirectly the Wightman axioms, in the following sense: Each $T$-invariant linear functional over the algebra automatically satisfies all the form factor axioms. It is argued that this answers the question (posed in the functional Bethe ansatz) how to select the dynamically correct representations of the $TTR$-algebra. Applied to the case of integrable QFTs w...
Magnetic form factors of the trinucleons
Schiavilla, R; Pandharipande, V R; Riska, Dan-Olof
1989-11-01
The magnetic form factors of ^{3}H and ^{3}He are calculated with the Monte Carlo method from variational ground-state wave functions obtained for the Argonne and Urbana two- and three-nucleon interactions. The electromagnetic current operator contains one- and two-body terms that are constructed so as to satisfy the continuity equation with the two-nucleon potential in the Hamiltonian. The results obtained with the Argonne two-nucleon interaction are in overall agreement with the empirical values. It appears that the remaining theoretical uncertainty, in the calculation of these form factors from a given interaction model, is dominated by that in the electromagnetic form factors of the nucleon. It is found that the isovector magnetic form factors are rather sensitive to the details of the isospin-dependent tensor force, and they are much better reproduced with the Argonne than the Urbana potential. The isoscalar magnetic form factors appear to be sensitive to the spin-orbit interactions, and are better reproduced with the Urbana potential. The Argonne potential has a stronger τ1∙τ2 tensor force, while the Urbana one has a shorter-range spin-orbit interaction.
Asymptotics of Heavy-Meson Form Factors
Grozin, A.G.; Grozin, Andrey G.; Neubert, Matthias
1997-01-01
Using methods developed for hard exclusive QCD processes, we calculate the asymptotic behaviour of heavy-meson form factors at large recoil. It is determined by the leading- and subleading-twist meson wave functions. For $1\\ll |v\\cdot v'|\\ll m_Q/\\Lambda$, the form factors are dominated by the Isgur--Wise function, which is determined by the interference between the wave functions of leading and subleading twist. At $|v\\cdot v'|\\gg m_Q/\\Lambda$, they are dominated by two functions arising at order $1/m_Q$ in the heavy-quark expansion, which are determined by the leading-twist wave function alone. The sum of these contributions describes the form factors in the whole region $|v\\cdot v'|\\gg 1$. As a consequence, there is an exact zero in the form factor for the scattering of longitudinally polarized $B^*$ mesons at some value $v\\cdot v'\\sim m_b/\\Lambda$, and an approximate zero in the form factor of $B$ mesons in the timelike region ($v\\cdot v'\\sim -m_b/\\Lambda$). We obtain the evolution equations and sum rules ...
Nucleon Form Factors - A Jefferson Lab Perspective
John Arrington, Kees de Jager, Charles F. Perdrisat
2011-06-01
The charge and magnetization distributions of the proton and neutron are encoded in their elastic electromagnetic form factors, which can be measured in elastic electron--nucleon scattering. By measuring the form factors, we probe the spatial distribution of the proton charge and magnetization, providing the most direct connection to the spatial distribution of quarks inside the proton. For decades, the form factors were probed through measurements of unpolarized elastic electron scattering, but by the 1980s, progress slowed dramatically due to the intrinsic limitations of the unpolarized measurements. Early measurements at several laboratories demonstrated the feasibility and power of measurements using polarization degrees of freedom to probe the spatial structure of the nucleon. A program of polarization measurements at Jefferson Lab led to a renaissance in the field of study, and significant new insight into the structure of matter.
The Form Factors of the Nucleons
Perdrisat, Charles F. [William and Mary College, JLAB
2013-11-01
There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has been greatly improved by performing double-polarization experiments, in comparison with with pre-vious unpolarized cross section data. Here we will review the experimental data base in view of the new results for the proton and the neutron, obtained at MIT-Bates, JLab and MAMI. The rapid evolution of phenomenological models triggered by these high- precision experiments will be discussed. In particular, the possibility that the proton is non-spherical in its ground state, and that the transverse charge density are model in- dependently defined in the infinite momentum frame. Likewise, flavor decomposition of the nucleon form factors into dressed u and d quark form factors, may give information about the quark-diquark structure of the nucleon. The current proton radius "crisis" will also be discussed.
Form factors for semileptonic D decays
Palmer, Teresa
2013-01-01
We study the form factors for semileptonic decays of $D$-mesons. That is, we consider the matrix element of the weak left-handed quark current for the transitions $D \\rightarrow P$ and $D \\rightarrow V$, where $P$ and $V$ are light pseudoscalar or vector mesons, respectively. Our motivation to perform the present study of these form factors are future calculations of non-leptonic decay amplitudes. We consider the form factors within a class of chiral quark models. Especially, we study how the Large Energy Effective Theory (LEET) limit works for $D$-meson decays. Compared to previous work we also introduce light vector mesons $V = \\rho, K^*,...$ within chiral quark models. In order to determine some of the parameters in our model, we use existing data and results based on some other methods like lattice calculations, light-cone sum rules, and heavy-light chiral perturbation theory. We also obtain some predictions within our framework.
The form factors of the nucleons
Perdrisat, C. F.
2013-11-01
There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has been greatly improved by performing double-polarization experiments, in comparison with with previous unpolarized cross section data. Here we will review the experimental data base in view of the new results for the proton and the neutron, obtained at MIT-Bates, JLab and MAMI. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed. In particular, the possibility that the proton is non-spherical in its ground state, and that the transverse charge density are model independently defined in the infinite momentum frame. Likewise, flavor decomposition of the nucleon form factors into dressed u and d quark form factors, may give information about the quark-diquark structure of the nucleon. The current proton radius "crisis" will also be discussed.
Chiral extrapolation of nucleon magnetic form factors
P. Wang; D. Leinweber; A. W. Thomas; R.Young
2007-04-01
The extrapolation of nucleon magnetic form factors calculated within lattice QCD is investigated within a framework based upon heavy baryon chiral effective-field theory. All one-loop graphs are considered at arbitrary momentum transfer and all octet and decuplet baryons are included in the intermediate states. Finite range regularization is applied to improve the convergence in the quark-mass expansion. At each value of the momentum transfer (Q{sup 2}), a separate extrapolation to the physical pion mass is carried out as a function of m{sub {pi}} alone. Because of the large values of Q{sup 2} involved, the role of the pion form factor in the standard pion-loop integrals is also investigated. The resulting values of the form factors at the physical pion mass are compared with experimental data as a function of Q{sup 2} and demonstrate the utility and accuracy of the chiral extrapolation methods presented herein.
Color-kinematic duality for form factors
Boels, Rutger H.; Kniehl, Bernd A.; Tarasov, Oleg V.; Yang, Gang [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik
2012-12-15
Recently a powerful duality between color and kinematics has been proposed for integrands of scattering amplitudes in quite general gauge theories. In this paper the duality proposal is extended to the more general class of gauge theory observables formed by form factors. After a discussion of the general setup the existence of the duality is verified in two and three loop examples in four dimensional maximally supersymmetric Yang-Mills theory which involve the stress energy tensor multiplet. In these cases the duality reproduces known results in a particularly transparent and uniform way. As a non-trivial application we obtain a very simple form of the integrand of the four-loop two-point (Sudakov) form factor which passes a large set of unitarity cut checks.
Form factors for $B \\to \\pi l\
Riazuddin, M; Gilani, A H S; Gilani, Amjad H S
2000-01-01
The form factors for the $B-->\\pi$ transition are evaluated in the entire momentum transfer range by using the constraints obtained in the framework combining the heavy quark expansion and chiral symmetry for light quarks and the quark model. In particular, we calculate the valence quark contributions and show that it together with the equal time commutator contribution simulate a B-meson pole q^2-dependence of form factors in addition to the usual vector meson B^{*}-pole diagram for $B --> \\pi l\
Electromagnetic proton form factors: perspectives for PANDA
Tomasi-Gustafsson Egle
2014-03-01
Full Text Available The PANDA collaboration studies fundamental aspects of the strong interaction in the transition region between non-perturbative and perturbative QCD, investigating charmonium spectroscopy, hybrids and glueballs, hypernuclei, light and heavy meson production with antiproton beams. In this contribution we focus on leptonic final channels which give access to nucleon electromagnetic form factors. The expected precision on the electric and magnetic form factors of the proton in the time-like region and the radiative corrections to be applied to the data are discussed.
$K_{l3}$ transition form factors
Ji, C R; Ji, Chueng-Ryong; Maris, Pieter
2001-01-01
The rainbow truncation of the quark Dyson-Schwinger equation is combined with the ladder Bethe-Salpeter equation for the meson bound state amplitudes and the dressed quark-W vertex in a manifestly covariant calculation of the K_{l3} transition form factors and decay width in impulse approximation. With model gluon parameters previously fixed by the chiral condensate, the pion mass and decay constant, and the kaon mass, our results for the K_{l3} form factors and the kaon semileptonic decay width are in good agreement with the experimental data.
Wilson Loop Form Factors: A New Duality
Chicherin, Dmitry; Heslop, Paul; Korchemsky, Gregory P.; Sokatchev, Emery
2016-01-01
We find a new duality for form factors of lightlike Wilson loops in planar $\\mathcal N=4$ super-Yang-Mills theory. The duality maps a form factor involving an $n$-sided lightlike polygonal super-Wilson loop together with $m$ external on-shell states, to the same type of object but with the edges of the Wilson loop and the external states swapping roles. This relation can essentially be seen graphically in Lorentz harmonic chiral (LHC) superspace where it is equivalent to planar graph duality....
Hyperfine splitting in hydrogen with form factors
Daza, F Garcia; Nowakowski, M
2010-01-01
Proton structure corrections to the hyperfine splittings in hydrogen are evaluated using the Breit potential with electromagnetic form factors. In contrast to other methods, several new features emerge: the Breit potential with $q^2$-dependent form factors is just an extension of the standard Breit equation which gives the hyperfine Hamiltonian. Order $\\alpha^5$ corrections are obtained from a one-photon exchange amplitude and time-independent perturbation theory. Structure corrections to $D_{21} = 8 E^{2S}_{hfs} - E^{1S}_{hfs}$ start at order $\\alpha^6$. QED corrections are comparable to structure corrections which must be evaluated ab initio.
Nucleon electromagnetic form factors with Wilson fermions
Goeckeler, M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Haegler, P. [Technische Univ. Muenchen, Garching (Germany). Inst. fuer Theoretische Physik; Horsley, R. [Edinburgh Univ. (GB). School of Physics] (and others)
2007-10-15
The nucleon electromagnetic form factors continue to be of major interest for experimentalists and phenomenologists alike. They provide important insights into the structure of nuclear matter. For a range of interesting momenta they can be calculated on the lattice. The limiting factor continues to be the value of the pion mass. We present the latest results of the QCDSF collaboration using gauge configurations with two dynamical, non-perturbatively improved Wilson fermions at pion masses as low as 350 MeV. (orig.)
[Relevance of Personality Factors for Successful Vocational Rehabilitation].
Arling, V; Slavchova, V; Knispel, J; Spijkers, W
2016-02-01
The Main purpose of vocational rehabilitation is occupational reintegration of clients into the job market who have lost their job or whose job is threatened because of a handicap or chronicl illness. With regard to existing evidence for the relevance of personality factors for work performance and job achievement, the present study investigated the influence of participants' personality factors on a successful reintegration after a retraining program in a vocational training center over 2 years. A central research objective was to identify prognostic personality factors for successful vocational integration. In this longitudinal study 15 vocational training centers participated at 3 time points of measurement (T1, T2 and T3). Data gathering was based on rehabilitants' self-reports (standardized questionnaires: SVF, BSW, SPR, CSES) about personality aspects. First data collection started at the beginning (T1) and a second survey was conducted at the end of the training 2 years later (T2). Based on the data at measurement points T1 and T2, 4 prognostic models were computed (binary logistic regression analysis) and evaluated, examining the differenzial influence of several scales and items on direct reintegration after completing the vocational retraining and reintegration status 6 months later (T3). As expected, different variables turned out to be relevant for occupational integration at the end of the training program and 6 months later. Correspondingly other variables appeared to be relevant for occupational reintegration at T1 and at T2. At the end of the vocational training program, approximately 24% of the participants had a job. With respect to direct reintegration, regression analysis revealed that vocational self-efficacy (R(2)=0,175) and self-evaluation were relevant (R(2)=0,383). Approximately 70% of the participants had gotten a job 6 months later. Several stress coping strategies (R(2)=0,170), estimation of the own reintegration prognosis and aspects
Baryon form factors in chiral perturbation theory
Kubis, B; Kubis, Bastian; Meissner, Ulf-G.
2001-01-01
We analyze the electromagnetic form factors of the ground state baryon octet to fourth order in relativistic baryon chiral perturbation theory. Predictions for the \\Sigma^- charge radius and the \\Lambda-\\Sigma^0 transition moment are found to be in excellent agreement with the available experimental information. Furthermore, the convergence behavior of the hyperon charge radii is shown to be more than satisfactory.
Electromagnetic Form Factor of Charged Scalar Meson
LI Heng-Mei; CHEN Ning; WANG Zhi-Gang; WAN Shao-Long
2007-01-01
Wavefunctions and the electromagnetic form factor of charged scalar mesons are studied with the vector-vectortype flat-bottom potential model under the framework of the spinor spinor Bethe Salpeter equation. The obtained results are in agreement with other theories.
Chiral analysis of baryon form factors
Gail, T.A.
2007-11-08
This work presents an extensive theoretical investigation of the structure of the nucleon within the standard model of elementary particle physics. In particular, the long range contributions to a number of various form factors parametrizing the interactions of the nucleon with an electromagnetic probe are calculated. The theoretical framework for those calculations is chiral perturbation theory, the exact low energy limit of Quantum Chromo Dynamics, which describes such long range contributions in terms of a pion-cloud. In this theory, a nonrelativistic leading one loop order calculation of the form factors parametrizing the vector transition of a nucleon to its lowest lying resonance, the {delta}, a covariant calculation of the isovector and isoscalar vector form factors of the nucleon at next to leading one loop order and a covariant calculation of the isoscalar and isovector generalized vector form factors of the nucleon at leading one loop order are performed. In order to perform consistent loop calculations in the covariant formulation of chiral perturbation theory an appropriate renormalization scheme is defined in this work. All theoretical predictions are compared to phenomenology and results from lattice QCD simulations. These comparisons allow for a determination of the low energy constants of the theory. Furthermore, the possibility of chiral extrapolation, i.e. the extrapolation of lattice data from simulations at large pion masses down to the small physical pion mass is studied in detail. Statistical as well as systematic uncertainties are estimated for all results throughout this work. (orig.)
Electromagnetic Transition form Factor of Nucleon Resonances
Sato, Toru
2016-10-01
A dynamical coupled channel model for electron and neutrino induced meson production reactions is developed. The model is an extension of our previous reaction model to describe reactions at finite Q^2. The electromagnetic transition form factors of the first (3/2^+,3/2) and (3/2^-,1/2) resonances extracted from partial wave amplitude are discussed.
From form factors to generalized parton distributions
Diehl, Markus
2013-06-15
I present an extraction of generalized parton distributions from selected data on the electromagnetic nucleon form factors. The extracted distributions can in particular be used to quantify the contribution to the proton spin from the total angular momentum carried by valence quarks, as well as their transverse spatial distribution inside the proton.
Nucleon and Elastic and Transition Form Factors
Segovia, Jorge; Cloët, Ian C.; Roberts, Craig D.; Schmidt, Sebastian M.
2014-12-01
We present a unified study of nucleon and elastic and transition form factors, and compare predictions made using a framework built upon a Faddeev equation kernel and interaction vertices that possess QCD-like momentum dependence with results obtained using a symmetry-preserving treatment of a vector vector contact-interaction. The comparison emphasises that experiments are sensitive to the momentum dependence of the running couplings and masses in the strong interaction sector of the Standard Model and highlights that the key to describing hadron properties is a veracious expression of dynamical chiral symmetry breaking in the bound-state problem. Amongst the results we describe, the following are of particular interest: possesses a zero at Q 2 = 9.5 GeV2; any change in the interaction which shifts a zero in the proton ratio to larger Q 2 relocates a zero in to smaller Q 2; there is likely a value of momentum transfer above which ; and the presence of strong diquark correlations within the nucleon is sufficient to understand empirical extractions of the flavour-separated form factors. Regarding the -baryon, we find that, inter alia: the electric monopole form factor exhibits a zero; the electric quadrupole form factor is negative, large in magnitude, and sensitive to the nature and strength of correlations in the Faddeev amplitude; and the magnetic octupole form factor is negative so long as rest-frame P- and D-wave correlations are included. In connection with the transition, the momentum-dependence of the magnetic transition form factor, , matches that of once the momentum transfer is high enough to pierce the meson-cloud; and the electric quadrupole ratio is a keen measure of diquark and orbital angular momentum correlations, the zero in which is obscured by meson-cloud effects on the domain currently accessible to experiment. Importantly, within each framework, identical propagators and vertices are sufficient to describe all properties discussed herein. Our
Baryon transition form factors at the pole
Tiator, L.; Döring, M.; Workman, R. L.; Hadžimehmedović, M.; Osmanović, H.; Omerović, R.; Stahov, J.; Švarc, A.
2016-12-01
Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. We derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the GM, GE, and GC form factors for the Δ (1232 ) resonance excitation at the Breit-Wigner resonance and pole positions up to Q2=5 GeV2 . We also explore the E /M and S /M ratios as functions of Q2. For pole and residue extraction, we apply the Laurent + Pietarinen method.
Baryon transition form factors at the pole
Tiator, L; Workman, R L; Hadžimehmedović, M; Osmanović, H; Omerović, R; Stahov, J; Švarc, A
2016-01-01
Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. We derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the $G_M$, $G_E$, and $G_C$ form factors for the $\\Delta(1232)$ resonance excitation at the Breit-Wigner resonance and pole positions up to $Q^2=5$ GeV$^2$. We also explore the $E/M$ and $S/M$ ratios as functions of $Q^2$. For pole and residue extraction, we apply the Laurent + Pietarinen method.
Baryon transition form factors at the pole
Tiator, L.; Döring, M.; Workman, R. L.; Hadžimehmedović, M.; Osmanović, H.; Omerović, R.; Stahov, J.; Švarc, A.
2016-12-01
Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. We derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the $G_M$, $G_E$, and $G_C$ form factors for the $\\Delta(1232)$ resonance excitation at the Breit-Wigner resonance and pole positions up to $Q^2=5$ GeV$^2$. We also explore the $E/M$ and $S/M$ ratios as functions of $Q^2$. For pole and residue extraction, we apply the Laurent + Pietarinen method.
CALCULATION OF KAON ELECTROMAGNETIC FORM FACTOR
WANG ZHI-GANG; WAN SHAO-LONG; WANG KE-LIN
2001-01-01
The kaon meson electromagnetic form factor is calculated in the framework of coupled Schwinger-Dyson and Bethe-Salpeter formulation in simplified impulse approximation (dressed vertex) with modified fiat-bottom potential,which is a combination of the flat-bottom potential taking into consideration the infrared and ultraviolet asymptotic behaviours of the effective quark-gluon coupling. All the numerical results give a good fit to experimental values.
Elastic form factors at higher CEBAF energies
Petratos, G.G. [Kent State Univ., OH (United States)
1994-04-01
The prospects for elastic scattering from few body systems with higher beam energies at CEBAF is presented. The deuteron and{sup 3}He elastic structure functions A(Q{sup 2}) can be measured at sufficiently high momentum transfers to study the transition between the conventional meson-nucleon and the constituent quark-gluon descriptions. Possible improvements in the proton magnetic form factor data are also presented.
On form factors and Macdonald polynomials
Lashkevich, Michael
2013-01-01
We are developing the algebraic construction for form factors of local operators in the sinh-Gordon theory proposed in [B.Feigin, M.Lashkeivch, 2008]. We show that the operators corresponding to the null vectors in this construction are given by the degenerate Macdonald polynomials with rectangular partitions and the parameters $t=-q$ on the unit circle. We obtain an integral representation for the null vectors and discuss its simple applications.
Towards a four-loop form factor
Boels, Rutger; Yang, Gang
2016-01-01
The four-loop, two-point form factor contains the first non-planar correction to the lightlike cusp anomalous dimension. This anomalous dimension is a universal function which appears in many applications. Its planar part in N = 4 SYM is known, in principle, exactly from AdS/CFT and integrability while its non-planar part has been conjectured to vanish. The integrand of the form factor of the stress-tensor multiplet in N = 4 SYM including the non-planar part was obtained in previous work. We parametrise the difficulty of integrating this integrand. We have obtained a basis of master integrals for all integrals in the four-loop, two-point class in two ways. First, we computed an IBP reduction of the integrand of the N = 4 form factor using massive computer algebra (Reduze). Second, we computed a list of master integrals based on methods of the Mint package, suitably extended using Macaulay2 / Singular. The master integrals obtained in both ways are consistent with some minor exceptions. The second method indic...
Higgs form factors in Associated Production
Isidori, Gino; CERN
2014-01-01
We further develop a form factor formalism characterizing anomalous interactions of the Higgs-like boson (h) to massive electroweak vector bosons (V) and generic bilinear fermion states (F). Employing this approach, we examine the sensitivity of pp -> F ->Vh associated production to physics beyond the Standard Model, and compare it to the corresponding sensitivity of h -> V F decays. We discuss how determining the Vh invariant-mass distribution in associated production at LHC is a key ingredient for model-independent determinations of h V F interactions. We also provide a general discussion about the power counting of the form factor's momentum dependence in a generic effective field theory approach, analyzing in particular how effective theories based on a linear and non-linear realization of the SU(2)_L x U(1)_Y gauge symmetry map into the form factor formalism. We point out how measurements of the differential spectra characterizing h -> V F decays and pp -> F -> Vh associated production could be the leadi...
Pion Electromagnetic Form Factor in Virtuality Distribution Formalism
Radyushkin, Anatoly V. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Old Dominion Univ., Norfolk, VA (United States)
2016-01-01
We discuss two applications of the {\\it Virtuality Distribution Amplitudes} (VDA) formalism developed in our recent papers. We start with an overview of the main properties of the pion distribution amplitude emphasizing the quantitative measures of its width, and possibility to access them through the pion transition form factor studies. We formulate the basic concepts of the VDA approach and introduce the pion {\\it transverse momentum distribution amplitude} (TMDA) which plays, in a covariant Lagrangian formulation, a role similar to that of the pion wave function in the 3-dimensional Hamiltonian light-front approach. We propose simple factorized models for soft TMDAs, and use them to describe existing data on the pion transition form factor, thus fixing the scale determining the size of the transverse-momentum effects. Finally, we apply the VDA approach to the one-gluon exchange contribution for the pion electromagnetic form factor. We observe a very late $Q^2 \\gtrsim 20$ GeV$^2$ onset of transition to the asymptotic pQCD predictions and show that in the $Q^2 \\lesssim 10$ GeV$^2$ region there is essentially no sensitivity to the shape of the pion distribution amplitude. Furthermore, the magnitude of the one-gluon exchange contribution in this region is estimated to be an order of magnitude below the Jefferson Lab data, thus leaving the Feynman mechanism as the only one relevant to the pion electromagnetic form factor behavior for accessible $Q^2$.
Nesse, Live L; Sekse, Camilla; Berg, Kristin; Johannesen, Karianne C S; Solheim, Heidi; Vestby, Lene K; Urdahl, Anne Margrete
2014-04-01
The biofilm-producing abilities of potentially human-pathogenic serotypes of Escherichia coli from the ovine reservoir were studied at different temperatures and on different surfaces. A possible influence of the hydrophobicity of the bacterial cells, as well as the presence of two virulence factors, the Shiga toxin-encoding (Stx) bacteriophage and the eae gene, was also studied. A total of 99 E. coli isolates of serotypes O26:H11, O103:H2, and O103:H25 isolated from sheep feces were included. The results show that isolates of all three E. coli serotypes investigated can produce biofilm on stainless steel, glass, and polystyrene at 12, 20, and 37°C. There was a good general correlation between the results obtained on the different surfaces. E. coli O103:H2 isolates produced much more biofilm than those of the other two serotypes at all three temperatures. In addition, isolates of serotype O26:H11 produced more biofilm than those of O103:H25 at 37°C. The hydrophobicity of the isolates varied between serotypes and was also influenced by temperature. The results strongly indicated that hydrophobicity influenced the attachment of the bacteria rather than their ability to form biofilm once attached. Isolates with the eae gene produced less biofilm at 37°C than isolates without this gene. The presence of a Stx bacteriophage did not influence biofilm production. In conclusion, our results show that potentially human-pathogenic E. coli from the ovine reservoir can form biofilm on various surfaces and at several temperatures relevant for food production and handling.
Analysis of the Relevant Factors of Retaining Women in Judo
Joško Sindik
2014-09-01
Full Text Available This study aimed to determine the latent dimensions of all relevant factors about engagement of women in judo, to determine the intercorrelations among these latent dimensions, as well as the correlations with three relevant variables. Final goal was to determine the differences in revealed latent dimensions, in relation to several independent variables: educational level, marital status, impulses to engage in judo, then depending are the women athletes (competitors or not, members of the Board or not, trainers or not. A total of 50 female judokas from a larger number of Croatian clubs were examined, by specially composed the survey. The results showed that all seven questionnaires showed medium to high satisfactory reliability, together with good con¬struct validity, in 15 latent dimensions that are revealed. It can be noticed that relatively older women have more obligations and more barriers that oppose to their engagement in judo. Only small number of differences are found among women engaged in judo, mainly among participants who are members of the Board in the club or Croatian Judo Federation, as compared with those who are not. Small number of statistically significant differences (as well as the correlations can be also observed as the fact that all women partially share similar problems, while the media strategies are perceived as the most powerful to increase women’s persistence in judo, in any type of engagement.
Relevant factors of stability of the financial sector
Oleg Lunyakov
2013-05-01
Full Text Available The cause and effect of relevant factors in the development of the financial sector and the level of macroeconomic stability are researched. Key indicators of financial imbalances, the stability of the financial sector, with GDP per capita by application to 29 countries, including Ukraine, are analyzed. It is shown that the declining of per capita GDP in 2009, in the context of the financial crisis, to a large extent has been caused by accumulated imbalances in the financial sector. Moreover, indicators of financial stability for all countries signaled the impending crisis. The models that can use by the monetary authorities (central banks for the forecast impact of the financial sector imbalances on macroeconomic stability are developed
Survey of nucleon electromagnetic form factors
Perdrisat, Charles F. [William and Mary College; Punjabi, Vina A. [Norfolk State U.
2011-09-20
There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has been greatly improved by performing double polarization experiments, in compar- ison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at MIT-Bates, MAMI, and JLab. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed.
Axial Nucleon form factors from lattice QCD
Alexandrou, C; Carbonell, J; Constantinou, M; Harraud, P A; Guichon, P; Jansen, K; Korzec, T; Papinutto, M
2010-01-01
We present results on the nucleon axial form factors within lattice QCD using two flavors of degenerate twisted mass fermions. Volume effects are examined using simulations at two volumes of spatial length $L=2.1$ fm and $L=2.8$ fm. Cut-off effects are investigated using three different values of the lattice spacings, namely $a=0.089$ fm, $a=0.070$ fm and $a=0.056$ fm. The nucleon axial charge is obtained in the continuum limit and chirally extrapolated to the physical pion mass enabling comparison with experiment.
Neutron electric form factor via recoil polarimetry
Madey, Richard; Semenov, Andrei; Taylor, Simon; Aghalaryan, Aram; Crouse, Erick; MacLachlan, Glen; Plaster, Bradley; Tajima, Shigeyuki; Tireman, William; Yan, Chenyu; Ahmidouch, Abdellah; Anderson, Brian; Asaturyan, Razmik; Baker, O; Baldwin, Alan; Breuer, Herbert; Carlini, Roger; Christy, Michael; Churchwell, Steve; Cole, Leon; Danagoulian, Samuel; Day, Donal; Elaasar, Mostafa; Ent, Rolf; Farkhondeh, Manouchehr; Fenker, Howard; Finn, John; Gan, Liping; Garrow, Kenneth; Gueye, Paul; Howell, Calvin; Hu, Bitao; Jones, Mark; Kelly, James; Keppel, Cynthia; Khandaker, Mahbubul; Kim, Wooyoung; Kowalski, Stanley; Lung, Allison; Mack, David; Manley, D; Markowitz, Pete; Mitchell, Joseph; Mkrtchyan, Hamlet; Opper, Allena; Perdrisat, Charles; Punjabi, Vina; Raue, Brian; Reichelt, Tilmann; Reinhold, Joerg; Roche, Julie; Sato, Yoshinori; Seo, Wonick; Simicevic, Neven; Smith, Gregory; Stepanyan, Samuel; Tadevosyan, Vardan; Tang, Liguang; Ulmer, Paul; Vulcan, William; Watson, John; Wells, Steven; Wesselmann, Frank; Wood, Stephen; Yan, Chen; Yang, Seunghoon; Yuan, Lulin; Zhang, Wei-Ming; Zhu, Hong Guo; Zhu, Xiaofeng
2003-05-01
The ratio of the electric to the magnetic form factor of the neutron, G_En/G_Mn, was measured via recoil polarimetry from the quasielastic d({pol-e},e'{pol-n)p reaction at three values of Q^2 [viz., 0.45, 1.15 and 1.47 (GeV/c)^2] in Hall C of the Thomas Jefferson National Accelerator Facility. Preliminary data indicate that G_En follows the Galster parameterization up to Q^2 = 1.15 (GeV/c)^2 and appears to rise above the Galster parameterization at Q^2 = 1.47 (GeV/c)^2.
TCP transcription factors: architectures of plant form.
Manassero, Nora G Uberti; Viola, Ivana L; Welchen, Elina; Gonzalez, Daniel H
2013-04-01
After its initial definition in 1999, the TCP family of transcription factors has become the focus of a multiplicity of studies related with plant development at the cellular, organ, and tissue levels. Evidence has accumulated indicating that TCP transcription factors are the main regulators of plant form and architecture and constitute a tool through which evolution shapes plant diversity. The TCP transcription factors act in a multiplicity of pathways related with cell proliferation and hormone responses. In recent years, the molecular pathways of TCP protein action and biochemical studies on their mode of interaction with DNA have begun to shed light on their mechanism of action. However, the available information is fragmented and a unifying view of TCP protein action is lacking, as well as detailed structural studies of the TCP-DNA complex. Also important, the possible role of TCP proteins as integrators of plant developmental responses to the environment has deserved little attention. In this review, we summarize the current knowledge about the structure and functions of TCP transcription factors and analyze future perspectives for the study of the role of these proteins and their use to modify plant development.
Measurements of hadron form factors at BESIII
Morales, Cristina Morales
2016-05-01
BEPCII is a symmetric e+e--collider located in Beijing running at center-of-mass energies between 2.0 and 4.6 GeV. This energy range allows the BESIII-experiment to measure hadron form factors both from direct e+e--annihilation and from initial state radiation processes. In this paper, results on e+e- → p p ¯ based on data collected by BESIII in 2011 and 2012 are presented. We also present preliminary results on e+e- → Λ Λ ¯ based on the same data samples at 4 center-of-mass energies. BESIII results obtained from e+e- → π+π- using the initial state radiation technique at the center-of-mass energy of 3.773 GeV are also summarized. Finally, expectations on the measurement of baryon electromagnetic form factors from the BESIII high luminosity energy scan in 2015 and from initial state radiation processes at different center-of-mass energies are also explained.
Measurements of Hadron Form Factors at BESIII
Morales, Cristina Morales
2016-01-01
BEPCII is a symmetric $e^+e^-$-collider located in Beijing running at center-of-mass energies between 2.0 and 4.6 GeV. This energy range allows the BESIII-experiment to measure hadron form factors both from direct $e^+e^-$-annihilation and from initial state radiation processes. In this paper, results on $e^+e^-\\rightarrow p\\bar{p}$ based on data collected by BESIII in 2011 and 2012 are presented. We also present preliminary results on $e^+e^-\\rightarrow \\Lambda \\bar{\\Lambda}$ based on the same data samples at 4 center-of-mass energies. BESIII results obtained from $e^+e^-\\rightarrow \\pi^+\\pi^-$ using the initial state radiation technique at the center-of-mass energy of 3.773 GeV are also summarized. Finally, expectations on the measurement of baryon electromagnetic form factors from the BESIII high luminosity energy scan in 2015 and from initial state radiation processes at different center-of-mass energies are also reported.
Lupus pleuritis: a relevant risk factor for pulmonary tuberculosis.
Pasoto, S G; Borba, E F; Bonfa, E; Shinjo, S K
2010-12-01
The objective of the study was to evaluate risk factors for pulmonary tuberculosis in systemic lupus erythematosus (SLE). Clinical/laboratorial features of 1283 SLE patients (ACR criteria) followed at the Lupus Clinic were obtained from the electronic register database from 2001 to 2009. Pulmonary tuberculosis was diagnosed in 20 patients (1.6%) (TB+ group). As control group (TB-), 40 patients without tuberculosis matched for age, gender, ethnicity, age at SLE diagnosis, and disease duration were arbitrarily selected. All 20 patients of the TB+ group presented confirmed pulmonary tuberculosis from 1 to 23 years after SLE diagnosis (7.6 ± 8.1 years). Frequencies of previous SLE involvements (cutaneous, articular, hematological, renal, pericarditis, pneumonitis, and central nervous system) were alike in TB+ and TB- groups (p > 0.05). In contrast, prior pleuritis was more frequent in the TB+ group (40% vs. 5%, p = 0.001). In fact, pulmonary tuberculosis was diagnosed in 8/10 patients with previous pleuritis. Immunosuppressive and corticosteroid therapies at the moment of tuberculosis diagnosis were also similar in both groups (p > 0.05). We have identified pleuritis as a relevant risk factor for pulmonary tuberculosis, suggesting that previous pleural injury is a critical part of the complex interplay between altered immune system, socio-economic conditions, and increased susceptibility to this mycobacterial infection.
Pathologically Relevant Prelamin A Interactions with Transcription Factors.
Infante, Arantza; Rodríguez, Clara I
2016-01-01
LMNA-linked laminopathies are a group of rare human diseases caused by mutations in LMNA or by disrupted posttranslational processing of its largest encoded isoform, prelamin A. The accumulation of mutated or immature forms of farnesylated prelamin A, named progerin or prelamin A, respectively, dominantly disrupts nuclear lamina structure with toxic effects in cells. One hypothesis is that aberrant lamin filament networks disrupt or "trap" proteins such as transcription factors, thereby interfering with their normal activity. Since laminopathies mainly affect tissues of mesenchymal origin, we tested this hypothesis by generating an experimental model of laminopathy by inducing prelamin A accumulation in human mesenchymal stem cells (hMSCs). We provide detailed protocols for inducing and detecting prelamin A accumulation in hMSCs, and describe the bioinformatic analysis and in vitro assays of transcription factors potentially affected by prelamin A accumulation.
Elastic and Transition Form Factors in DSEs
Segovia, Jorge
2016-01-01
A symmetry preserving framework for the study of continuum Quantum Chromodynamics (QCD) is obtained from a truncated solution of the QCD equations of motion or QCD's Dyson-Schwinger equations (DSEs). A nonperturbative solution of the DSEs enables the study of, e.g., hadrons as composites of dressed-quarks and dressed-gluons, the phenomena of confinement and dynamical chiral symmetry breaking (DCSB), and therefrom an articulation of any connection between them. It is within this context that we present a unified study of Nucleon, Delta and Roper elastic and transition form factors, and compare predictions made using a framework built upon a Faddeev equation kernel and interaction vertices that possess QCD-like momentum dependence with results obtained using a symmetry-preserving treatment of a vector$\\,\\otimes\\,$vector contact-interaction.
Elastic and Transition Form Factors in DSEs
Segovia, Jorge
2016-06-01
A symmetry preserving framework for the study of continuum quantum chromodynamics (QCD) is obtained from a truncated solution of the QCD equations of motion or QCD's Dyson-Schwinger equations (DSEs). A nonperturbative solution of the DSEs enables the study of, e.g., hadrons as composites of dressed-quarks and dressed-gluons, the phenomena of confinement and dynamical chiral symmetry breaking, and therefrom an articulation of any connection between them. It is within this context that we present a unified study of Nucleon, Delta and Roper elastic and transition form factors, and compare predictions made using a framework built upon a Faddeev equation kernel and interaction vertices that possess QCD-like momentum dependence with results obtained using a symmetry-preserving treatment of a vector ⊗ vector contact-interaction.
Form Factors of Few-Body Systems: Point Form Versus Front Form
Gómez-Rocha, Maria; Schweiger, Wolfgang
2011-01-01
We present a relativistic point-form approach for the calculation of electroweak form factors of few-body bound states that leads to results which resemble those obtained within the covariant light-front formalism of Carbonell et al. Our starting points are the physical processes in which such form factors are measured, i.e. electron scattering off the bound state, or the semileptonic weak decay of the bound state. These processes are treated by means of a coupled-channel framework for a Bakamjian-Thomas type mass operator. A current with the correct covariance properties is then derived from the pertinent leading-order electroweak scattering or decay amplitude. As it turns out, the electromagnetic current is affected by unphysical contributions which can be traced back to wrong cluster properties inherent in the Bakamjian-Thomas construction. These spurious contributions, however, can be separated uniquely, as in the covariant light-front approach. In this way we end up with form factors which agree with tho...
[Analyses prognostic factors relevant to sudden sensorineural hearing loss].
Wang, Jun; Xiao, Shuifang; Zeng, Zhengang; Zhen, Zhen; Zhang, Xuexi; Lin, Feng; Dong, Mingmin; Lu, Wei; Qin, Zhaobing; Zuo, Bin; Bai, Xianfeng
2015-06-01
To investigate the prognostic factors relevant to sudden sensorineural hearing loss. The internationally accepted standardized clinical research methods, unified design, and unified program were adopted to conduct the prospective clinical multi-center study. The sudden deafness patients between 18 to 65 years old, with the course of this disorder less than two weeks, and without any medical treatments were collected, and then, divided into four types according to the hearing curve: type A, acute sensorineural hearing loss in low tone frequencies; type B, acute sensorineural hearing loss in high tone frequencies; type C, acute sensorineural hearing loss in all frequencies; and type D, total deafness. The factors, in terms of age, gender, type of initial audiogram, time delay before the first visit, and severity of hearing loss, were included in the analyses. A total of 1 024 cases with single side sudden deafness were collected in the study from 33 hospitals in China from August 2007 to October 2011, inclusive of for 492 males (48.05%) and 532 females (51.95%). The average age was (41.2 ± 12.8) years old. There were 553 cases (54.00%) in left ear, and 471 cases (46.00%) in right ear. The curative effects of different types were shown as follows: the type in low tone frequencies had the highest rate of 90.73%, the type in all frequencies was 82.59%; the type of total deafness was 70.29%; and the type in high tone frequencies had the lowest rate of 65.96%. It had significant difference of the effective rate between different types (χ(2) = 231.58, P = 0.000). Age, time delay before first visit, and severity of initial hearing loss were significantly correlated with hearing improvement. Initial audiogram of SSNHL might predict hearing recovery. The young in age and a short time delay before starting treatment are positive prognostic factors for hearing recovery in SSNHL. The initial severity of hearing loss is negative prognostic factor of hearing recovery.
Classifying transcription factor targets and discovering relevant biological features
DeLisi Charles
2008-05-01
Full Text Available Abstract Background An important goal in post-genomic research is discovering the network of interactions between transcription factors (TFs and the genes they regulate. We have previously reported the development of a supervised-learning approach to TF target identification, and used it to predict targets of 104 transcription factors in yeast. We now include a new sequence conservation measure, expand our predictions to include 59 new TFs, introduce a web-server, and implement an improved ranking method to reveal the biological features contributing to regulation. The classifiers combine 8 genomic datasets covering a broad range of measurements including sequence conservation, sequence overrepresentation, gene expression, and DNA structural properties. Principal Findings (1 Application of the method yields an amplification of information about yeast regulators. The ratio of total targets to previously known targets is greater than 2 for 11 TFs, with several having larger gains: Ash1(4, Ino2(2.6, Yaf1(2.4, and Yap6(2.4. (2 Many predicted targets for TFs match well with the known biology of their regulators. As a case study we discuss the regulator Swi6, presenting evidence that it may be important in the DNA damage response, and that the previously uncharacterized gene YMR279C plays a role in DNA damage response and perhaps in cell-cycle progression. (3 A procedure based on recursive-feature-elimination is able to uncover from the large initial data sets those features that best distinguish targets for any TF, providing clues relevant to its biology. An analysis of Swi6 suggests a possible role in lipid metabolism, and more specifically in metabolism of ceramide, a bioactive lipid currently being investigated for anti-cancer properties. (4 An analysis of global network properties highlights the transcriptional network hubs; the factors which control the most genes and the genes which are bound by the largest set of regulators. Cell-cycle and
Pion transition form factor in k_T factorization
Li, Hsiang-nan
2009-01-01
It has been pointed out that the recent BaBar data on the pi gamma^* -> gamma transition form factor F_{pi gamma}(Q^2) at low (high) momentum transfer squared Q^2 indicate an asymptotic (flat) pion distribution amplitude. These seemingly contradictory observations can be reconciled in the k_T factorization theorem: the increase of the measured Q^2F_{pi gamma}(Q^2) for Q^2 > 10 GeV^2 is explained by convoluting a k_T dependent hard kernel with a flat pion distribution amplitude, k_T being a parton transverse momentum. The low Q^2 data are accommodated by including the resummation of alpha_s ln^2x, x being a parton momentum fraction, which provides a stronger suppression at the endpoints of x. The next-to-leading-order correction to the pion transition form factor is found to be less than 20% in the considered range of Q^2.
Pion transition form factor in k{sub T} factorization
Li, Hsiang-nan [Academica Sinica, Taipei, Taiwan (China). Inst. of Physics; Tsing-Hua Univ., Hsinchu, Taiwan (China). Dept. of Phyiscs; National Cheng-Kung Univ., Tainan, Taiwan (China). Dept. of Physics; National Cheng-Chi Univ, Taipei, Taiwan (China). Inst. of Applied Physics; Mishima, Satoshi [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2009-07-15
It has been pointed out that the recent BaBar data on the {pi}{gamma}{sup *} {yields} {gamma} transition form factor F{sub {pi}}{sub {gamma}}(Q{sup 2}) at low (high) momentum transfer squared Q{sup 2} indicate an asymptotic (flat) pion distribution amplitude. These seemingly contradictory observations can be reconciled in the k{sub T} factorization theorem: the increase of the measured Q{sup 2}FF{sub {pi}}{sub {gamma}}(Q{sup 2}) for Q{sup 2} > 10 GeV{sup 2} is explained by convoluting a k{sub T} dependent hard kernel with a flat pion distribution amplitude, k{sub T} being a parton transverse momentum. The low Q{sup 2} data are accommodated by including the resummation of {alpha}{sub s} ln{sup 2}x, x being a parton momentum fraction, which provides a stronger suppression at the endpoints of x. The next-to-leading-order correction to the pion transition form factor is found to be less than 20% in the considered range of Q{sup 2}. (orig.)
Gravitational form factors and nucleon spin structure
Teryaev, O. V.
2016-10-01
Nucleon scattering by the classical gravitational field is described by the gravitational (energy-momentum tensor) form factors (GFFs), which also control the partition of nucleon spin between the total angular momenta of quarks and gluons. The equivalence principle (EP) for spin dynamics results in the identically zero anomalous gravitomagnetic moment, which is the straightforward analog of its electromagnetic counterpart. The extended EP (ExEP) describes its (approximate) validity separately for quarks and gluons and, in turn, results in equal partition of the momentum and total angular momentum. It is violated in quantum electrodynamics and perturbative quantum chromodynamics (QCD), but may be restored in nonperturbative QCD because of confinement and spontaneous chiral symmetry breaking, which is supported by models and lattice QCD calculations. It may, in principle, be checked by extracting the generalized parton distributions from hard exclusive processes. The EP for spin-1 hadrons is also manifested in inclusive processes (deep inelastic scattering and the Drell-Yan process) in sum rules for tensor structure functions and parton distributions. The ExEP may originate in either gravity-proof confinement or in the closeness of the GFF to its asymptotic values in relation to the mediocrity principle. The GFFs in time-like regions reveal some similarity between inflation and annihilation.
Proton Form Factor Measurements at Jefferson Lab
Charles Perdrisat; Vina Punjabi
2004-09-27
In two experiments at Jefferson Lab in Hall A, the first one in 1998 and the second in 2000, the ratio of the electromagnetic form factors of the proton was obtained by measuring P{sub t} and P{sub ell}, the transverse and longitudinal recoil proton polarization components, respectively, in {rvec e}p {yields} e{rvec p}; the ratio G{sub E{sub p}}/G{sub M{sub p}} is proportional to P{sub t}/P{sub {ell}}. Simultaneous measurement of P{sub t} and P{sub {ell}} provides good control of the systematic uncertainty. The first measurement of G{sub E{sub p}}/G{sub M{sub p}} ratio was made to Q{sup 2} = 3.5 GeV{sup 2} and the second measurement to Q{sup 2} = 5.6 GeV{sup 2}. The results from these two experiments indicate that the ratio scales like 1/Q{sup 2}, in stark contrast with cross section data analyzed by the Rosenbluth separation method which gives a constant value for this ratio. The incompatibility of the recoil polarization results with most of the Rosenbluth separation results appears now well established above Q{sup 2} of about 3 GeV{sup 2}. The consensus at the present time is that the interference of the two-photon exchange with the Born term, which had been deemed negligible until recently, might explain the discrepancy between the results of the two techniques; the possibility that the discrepancy is due to incomplete radiative correction has also been recently discussed.
Effects of an electromagnetic quark form factor on meson properties
Silvestre-Brac, B. E-mail: silvestre@isn.in2p3.fr
2002-12-30
A form factor is introduced in the quark electromagnetic current. Its effect is analyzed on charge mean square radii and form factors in the mesonic sector. The decay of a vector meson into lepton-antilepton pair is also affected. Two different expressions for the form factors, and two different types of quark potential are tested and some relativistic kinematical corrections are proposed. In any case the introduction of a quark form factor greatly improves the agreement with experimental data.
The pion form factor from analyticity and unitarity
B Ananthanarayan; Irinel Caprini; I Sentitemsu Imsong
2012-11-01
Analyticity and unitarity techniques are employed to estimate Taylor coefficients of the pion electromagnetic form factor at = 0 by exploiting the recently evaluated two-pion contribution to the muon ( − 2) and the phase of the pion electromagnetic form factor in the elastic region, known from scattering by Fermi–Watson theorem and the values of the form factor at several points in the space-like region. Regions in the complex -plane are isolated where the form factor cannot have zeros.
MesonNet Workshop on Meson Transition Form Factors
Eidelman, S; Hanhart, C; Kubis, B; Kupsc, A; Leupold, S; Moskal, P; Schadmand, S
2012-01-01
The mini-proceedings of the Workshop on Meson Transition Form Factors held in Cracow from May 29th to 30th, 2012 introduce the meson transition form factor project with special emphasis on the interrelations between the various form factors (on-shell, single off-shell, double off-shell). Short summaries of the talks presented at the workshop follow.
Xiang, Xiaohong; Deng, Wanyan; Liu, Minqiang; Xie, Jianping
2014-01-01
Many bacteria can develop biofilm (BF), a multicellular structure largely combining bacteria and their extracellular polymeric substances (EPS). The formation of biofilm results in an alternative existence in which microbes ensure their survival in adverse environments. Biofilm-relevant infections are more persistent, resistant to most antibiotics, and more recalcitrant to host immunity. Mycobacterium tuberculosis, the causative agent of tuberculosis, can develop biofilm, though whether M. tuberculosis can form biofilm within tuberculosis patients has yet to be determined. Here, we summarize the factors involved in the development and dispersal of mycobacterial biofilms, as well as underlying regulatory factors and inhibitors against biofilm to deepen our understanding of their development and to elucidate potential novel modes of action for future antibiotics. Key factors in biofilm formation identified as drug targets represent a novel and promising avenue for developing better antibiotics.
C. Jackisch
2017-07-01
Full Text Available The study deals with the identification and characterization of rapid subsurface flow structures through pedo- and geo-physical measurements and irrigation experiments at the point, plot and hillslope scale. Our investigation of flow-relevant structures and hydrological responses refers to the general interplay of form and function, respectively. To obtain a holistic picture of the subsurface, a large set of different laboratory, exploratory and experimental methods was used at the different scales. For exploration these methods included drilled soil core profiles, in situ measurements of infiltration capacity and saturated hydraulic conductivity, and laboratory analyses of soil water retention and saturated hydraulic conductivity. The irrigation experiments at the plot scale were monitored through a combination of dye tracer, salt tracer, soil moisture dynamics, and 3-D time-lapse ground penetrating radar (GPR methods. At the hillslope scale the subsurface was explored by a 3-D GPR survey. A natural storm event and an irrigation experiment were monitored by a dense network of soil moisture observations and a cascade of 2-D time-lapse GPR trenches. We show that the shift between activated and non-activated state of the flow paths is needed to distinguish structures from overall heterogeneity. Pedo-physical analyses of point-scale samples are the basis for sub-scale structure inference. At the plot and hillslope scale 3-D and 2-D time-lapse GPR applications are successfully employed as non-invasive means to image subsurface response patterns and to identify flow-relevant paths. Tracer recovery and soil water responses from irrigation experiments deliver a consistent estimate of response velocities. The combined observation of form and function under active conditions provides the means to localize and characterize the structures (this study and the hydrological processes (companion study Angermann et al., 2017, this issue.
Jackisch, Conrad; Angermann, Lisa; Allroggen, Niklas; Sprenger, Matthias; Blume, Theresa; Tronicke, Jens; Zehe, Erwin
2017-07-01
The study deals with the identification and characterization of rapid subsurface flow structures through pedo- and geo-physical measurements and irrigation experiments at the point, plot and hillslope scale. Our investigation of flow-relevant structures and hydrological responses refers to the general interplay of form and function, respectively. To obtain a holistic picture of the subsurface, a large set of different laboratory, exploratory and experimental methods was used at the different scales. For exploration these methods included drilled soil core profiles, in situ measurements of infiltration capacity and saturated hydraulic conductivity, and laboratory analyses of soil water retention and saturated hydraulic conductivity. The irrigation experiments at the plot scale were monitored through a combination of dye tracer, salt tracer, soil moisture dynamics, and 3-D time-lapse ground penetrating radar (GPR) methods. At the hillslope scale the subsurface was explored by a 3-D GPR survey. A natural storm event and an irrigation experiment were monitored by a dense network of soil moisture observations and a cascade of 2-D time-lapse GPR trenches. We show that the shift between activated and non-activated state of the flow paths is needed to distinguish structures from overall heterogeneity. Pedo-physical analyses of point-scale samples are the basis for sub-scale structure inference. At the plot and hillslope scale 3-D and 2-D time-lapse GPR applications are successfully employed as non-invasive means to image subsurface response patterns and to identify flow-relevant paths. Tracer recovery and soil water responses from irrigation experiments deliver a consistent estimate of response velocities. The combined observation of form and function under active conditions provides the means to localize and characterize the structures (this study) and the hydrological processes (companion study Angermann et al., 2017, this issue).
Nucleon Form Factors in the Space- and Timelike Regions
Hammer, H W
2001-01-01
Dispersion relations provide a powerful tool to describe the electromagnetic form factors of the nucleon both in the spacelike and timelike regions with constraints from unitarity and perturbative QCD. We give a brief introduction into dispersion theory for nucleon form factors and present results from a recent form factor analysis. Particular emphasis is given to the form factors in the timelike region. Furthermore, some recent results for the spacelike form factors at low momentum transfer from a ChPT calculation by Kubis and Meissner are discussed.
Chou-Yang model and PHI form factor
Fazal-e-Aleem; Saleem, M.; Rafique, M.
1988-03-01
By using the deduced differential cross-section data for PHIp elastic scattering at 175 GeV/c in the Chou-Yang model, the PHI form factor has been computed and parametrized. Then in conjunction with the proton form factor this form factor is used in the pristine Chou-Yang model to obtain differential cross-section data at Fermilab energies. The theoretical results agree with the experimental measurements, endorsing the conjecture that the hadronic form factor of neutral particle is proportional to its magnetic form factor.
Key factors relevant to In-service teacher training
汪晖
2016-01-01
Successful continuing professional development (CPD) is beneficial not only to teachers' professional growth, but also to the development of their school and children. This essay will explain some key factors, regarding needs analysis, approach, goals and objectives, training methodology, assessment, in my essay.
Relevant Factors for Establishing Inter-firm Cooperation Networks in Rio Grande do Sul
Jorge Renato Verschoore
2008-10-01
Full Text Available The cooperation among firms in a network form has been stressed as an alternative organizational configuration in response to recent economic transformation. The increased number of initiatives and the empirical research scarcity on the network formation in Brazil motivated the present study. The main objective of this paper is to comprehend the factors which effect the establishment of network cooperation in the Southern Brazilian context. In order to achieve this objective a quantitative research was carried out with 443 enterprise representatives, associated to 120 cooperation networks. The empirical data were collected by the researchers in 2005 and statistically processed through a conjoint analysis. The results confirmed the theoretical propositions built by the researchers,appointing the relevance of factors, such as learning and innovation, increased scale and market power, and access to solutions.
Relevant Affect Factors of Smartphone Mobile Data Traffic
Siniša Husnjak
2016-08-01
Full Text Available Smartphones are used to access a wide range of different information and communication services and perform functions based on data transfer. A number of subscription contracts for smartphones is rapidly increasing, and the development of mobile communications network provides higher speed of data transfer. The continuous increase in the average amount of data traffic per one subscriber contract leads to an increase in the total Mobile Data Traffic (MDT, globally. This research represents a summary of factors that affect the amount of smartphone MDT. Previous literature shows only a few of the factors individually that affect the realization of smartphone MDT. The results of the research clarify the ways which influence the amount of MDT generated by a smartphone. This paper increases the awareness of the users of the methods of generating smartphone MDT. The research also allows users to specify parameters that affect the prediction of generated MDT of a smartphone.
Lecomte, Tania; Corbière, Marc; Laisné, François
2006-06-30
Studies investigating self-esteem in individuals with severe mental illness, either as a treatment goal, outcome or correlate to other variables, have increased over the past few years. One of the main difficulties in assessing self-esteem is the assessment itself, often measuring global and stable self-esteem as in the Rosenberg Self-Esteem Scale, or requiring extensive training and long interviews. The present article aims at demonstrating the relevance of the French and English versions of the Self-Esteem Rating Scale-Short Form with individuals with severe mental illness. The instrument's reliability and validity were investigated in a sample of 250 French Canadian college students, 247 British college students and three samples of English- or French-speaking individuals with severe mental illness (N=254, N=150 and N=171). Confirmatory factor analysis revealed that a shorter version of the instrument (20 items), with a positive and a negative self-esteem factor, had a great validity for all the samples studied. The Self-Esteem Rating Scale-Short Form, with its positive and negative self-esteem subscales, appears to be a valid and reliable self-esteem measure for individuals with mental health problems. Limitations of this study and future directions are discussed.
Higginson, D. P.; Revet, G.; Khiar, B.; Béard, J.; Blecher, M.; Borghesi, M.; Burdonov, K.; Chen, S. N.; Filippov, E.; Khaghani, D.; Naughton, K.; Pépin, H.; Pikuz, S.; Portugall, O.; Riconda, C.; Riquier, R.; Ryazantsev, S. N.; Skobelev, I. Yu.; Soloviev, A.; Starodubtsev, M.; Vinci, T.; Willi, O.; Ciardi, A.; Fuchs, J.
2017-06-01
The collimation of astrophysically-relevant plasma ejecta in the form of narrow jets via a poloidal magnetic field is studied experimentally by irradiating a target situated in a 20 T axial magnetic field with a 40 J, 0.6 ns, 0.7 mm diameter, high-power laser. The dynamics of the plasma shaping by the magnetic field are studied over 70 ns and up to 20 mm from the source by diagnosing the electron density, temperature and optical self-emission. These show that the initial expansion of the plasma is highly magnetized, which leads to the formation of a cavity structure when the kinetic plasma pressure compresses the magnetic field, resulting in an oblique shock [A. Ciardi et al., Phys. Rev. Lett. 110, 025002 (2013)]. The resulting poloidal magnetic nozzle collimates the plasma into a narrow jet [B. Albertazzi et al., Science 346, 325 (2014)]. At distances far from the target, the jet is only marginally magnetized and maintains a high aspect ratio due to its high Mach-number (M ∼ 20) and not due to external magnetic pressure. The formation of the jet is evaluated over a range of laser intensities (1012-1013 W/cm2), target materials and orientations of the magnetic field. Plasma cavity formation is observed in all cases and the viability of long-range jet formation is found to be dependent on the orientation of the magnetic field.
Dust from AGBs: relevant factors and modelling uncertainties
Ventura, P; Schneider, R; Di Criscienzo, M; Rossi, C; La Franca, F; Gallerani, S; Valiante, R
2014-01-01
The dust formation process in the winds of Asymptotic Giant Branch stars is discussed, based on full evolutionary models of stars with mass in the range $1$M$_{\\odot} \\leq$M$\\leq 8$M$_{\\odot}$, and metallicities $0.001 < Z <0.008$. Dust grains are assumed to form in an isotropically expanding wind, by growth of pre--existing seed nuclei. Convection, for what concerns the treatment of convective borders and the efficiency of the schematization adopted, turns out to be the physical ingredient used to calculate the evolutionary sequences with the highest impact on the results obtained. Low--mass stars with M$\\leq 3$M$_{\\odot}$ produce carbon type dust with also traces of silicon carbide. The mass of solid carbon formed, fairly independently of metallicity, ranges from a few $10^{-4}$M$_{\\odot}$, for stars of initial mass $1-1.5$M$_{\\odot}$, to $\\sim 10^{-2}$M$_{\\odot}$ for M$\\sim 2-2.5$M$_{\\odot}$; the size of dust particles is in the range $0.1 \\mu$m$\\leq a_C \\leq 0.2\\mu$m. On the contrary, the production...
Identification of Immune-Relevant Factors Conferring Sarcoidosis Genetic Risk
Fischer, Annegret; Ellinghaus, David; Nutsua, Marcel; Hofmann, Sylvia; Montgomery, Courtney G.; Iannuzzi, Michael C.; Rybicki, Benjamin A.; Petrek, Martin; Mrazek, Frantisek; Pabst, Stefan; Grohé, Christian; Grunewald, Johan; Ronninger, Marcus; Eklund, Anders; Padyukov, Leonid; Mihailovic-Vucinic, Violeta; Jovanovic, Dragana; Sterclova, Martina; Homolka, Jiri; Nöthen, Markus M.; Herms, Stefan; Gieger, Christian; Strauch, Konstantin; Winkelmann, Juliane; Boehm, Bernhard O.; Brand, Stephan; Büning, Carsten; Schürmann, Manfred; Ellinghaus, Eva; Baurecht, Hansjörg; Lieb, Wolfgang; Nebel, Almut; Müller-Quernheim, Joachim; Franke, Andre
2015-01-01
Rationale: Genetic variation plays a significant role in the etiology of sarcoidosis. However, only a small fraction of its heritability has been explained so far. Objectives: To define further genetic risk loci for sarcoidosis, we used the Immunochip for a candidate gene association study of immune-associated loci. Methods: Altogether the study population comprised over 19,000 individuals. In a two-stage design, 1,726 German sarcoidosis cases and 5,482 control subjects were genotyped for 128,705 single-nucleotide polymorphisms using the Illumina Immunochip for the screening step. The remaining 3,955 cases, 7,514 control subjects, and 684 parents of affected offspring were used for validation and replication of 44 candidate and two established risk single-nucleotide polymorphisms. Measurements and Main Results: Four novel susceptibility loci were identified with genome-wide significance in the European case-control populations, located on chromosomes 12q24.12 (rs653178; ATXN2/SH2B3), 5q33.3 (rs4921492; IL12B), 4q24 (rs223498; MANBA/NFKB1), and 2q33.2 (rs6748088; FAM117B). We further defined three independent association signals in the HLA region with genome-wide significance, peaking in the BTNL2 promoter region (rs5007259), at HLA-B (rs4143332/HLA-B*0801) and at HLA-DPB1 (rs9277542), and found another novel independent signal near IL23R (rs12069782) on chromosome 1p31.3. Conclusions: Functional predictions and protein network analyses suggest a prominent role of the drug-targetable IL23/Th17 signaling pathway in the genetic etiology of sarcoidosis. Our findings reveal a substantial genetic overlap of sarcoidosis with diverse immune-mediated inflammatory disorders, which could be of relevance for the clinical application of modern therapeutics PMID:26051272
THE FACTORS FORMING QUALITY OF GRANULATED SUGAR
N. G. Kulneva
2015-01-01
Full Text Available Sugar, with good taste and high caloric, is one of the most popular human food. Consumers sugar must be sure that the sugar under normal conditions of use is of high quality and is not harmful to the health of the product. One reason for the decline in the quality of sugar is bacterial contamination. This is because the sugar industry products are good targets for the development of different groups of microorganisms, e.g., Bacillus subtilis, Clostridium perfringes, Leuconostoc dextranicum, Torula alba, Pseudomonas fluorescens, Sarcina lutea and others. These organisms are affected with beets, and then with sugar beet chips and diffusion juice fall into the processing line of sugar production. Their number in the diffusion juice varies and depends on many facto rs such as the quality of raw materials, the quality of cleaning beet root colonization of transporter-washing and the supply of water to the diffusion process, the temperature of the diffusion and others. In the diffusion unit has the most favorable conditions for the development of micro-organisms. Some of them, especially resistant bacteria and thermophilic bacteria or their spores, forming a capsule which protects against external influences occur in the final product sugar. When injected into the fresh crop of product (juice, syrup, they begin to multiply rapidly, causing difficulties in the process. The higher seeding beet microorganisms, the more they decompose and emit sucrose metabolism byproducts. To reduce the negative impact of microbiological and reduce losses from decomposition of sucrose conducted research on the possibility of using chlorine-containing substances in the sugar industry. It was established experimentally that the investigated chlorinated drug has bacteriostatic action and can be recommended for use in sugar beet production.
Progress in the Calculation of Nucleon Transition form Factors
Eichmann, Gernot
2016-10-01
We give a brief account of the Dyson-Schwinger and Faddeev-equation approach and its application to nucleon resonances and their transition form factors. We compare the three-body with the quark-diquark approach and present a quark-diquark calculation for the low-lying nucleon resonances including scalar, axialvector, pseudoscalar and vector diquarks. We also discuss the timelike structure of transition form factors and highlight the advantages of form factors over helicity amplitudes.
Progress in the calculation of nucleon transition form factors
Eichmann, Gernot
2016-01-01
We give a brief account of the Dyson-Schwinger and Faddeev-equation approach and its application to nucleon resonances and their transition form factors. We compare the three-body with the quark-diquark approach and present a quark-diquark calculation for the low-lying nucleon resonances including scalar, axialvector, pseudoscalar and vector diquarks. We also discuss the timelike structure of transition form factors and highlight the advantages of form factors over helicity amplitudes.
Relevant principal factors affecting the reproducibility of insect primary culture.
Ogata, Norichika; Iwabuchi, Kikuo
2017-06-01
The primary culture of insect cells often suffers from problems with poor reproducibility in the quality of the final cell preparations. The cellular composition of the explants (cell number and cell types), surgical methods (surgical duration and surgical isolation), and physiological and genetic differences between donors may be critical factors affecting the reproducibility of culture. However, little is known about where biological variation (interindividual differences between donors) ends and technical variation (variance in replication of culture conditions) begins. In this study, we cultured larval fat bodies from the Japanese rhinoceros beetle, Allomyrina dichotoma, and evaluated, using linear mixed models, the effect of interindividual variation between donors on the reproducibility of the culture. We also performed transcriptome analysis of the hemocyte-like cells mainly seen in the cultures using RNA sequencing and ultrastructural analyses of hemocytes using a transmission electron microscope, revealing that the cultured cells have many characteristics of insect hemocytes.
Nucleon form factors in the canonically quantized Skyrme model
Acus, A.; Norvaisas, E. [Lithuanian Academy of Sciences, Vilnius (Lithuania). Inst. of Theoretical Physics and Astronomy; Riska, D.O. [Helsinki Univ. (Finland). Dept. of Physics; Helsinki Univ. (Finland). Helsinki Inst. of Physics
2001-08-01
The explicit expressions for the electric, magnetic, axial and induced pseudoscalar form factors of the nucleons are derived in the ab initio quantized Skyrme model. The canonical quantization procedure ensures the existence of stable soliton solutions with good quantum numbers. The form factors are derived for representations of arbitrary dimension of the SU(2) group. After fixing the two parameters of the model, f{sub {pi}} and e, by the empirical mass and electric mean square radius of the proton, the calculated electric and magnetic form factors are fairly close to the empirical ones, whereas the the axial and induced pseudoscalar form factors fall off too slowly with momentum transfer. (orig.)
Nucleon form factors in the canonically quantized Skyrme model
Acus, A; Riska, D O
2001-01-01
The explicit expressions for the electric, magnetic, axial and induced pseudoscalar form factors of the nucleons are derived in the {\\it ab initio} quantized Skyrme model. The canonical quantization procedure ensures the existence of stable soliton solutions with good quantum numbers. The form factors are derived for representations of arbitrary dimension of the SU(2) group. After fixing the two parameters of the model, $f_\\pi$ and $e$, by the empirical mass and electric mean square radius of the proton, the calculated electric and magnetic form factors are fairly close to the empirical ones, whereas the the axial and induced pseudoscalar form factors fall off too slowly with momentum transfer.
Dispersion Relation for the Nucleon Electromagnetic Form Factors
Furuichi, Susumu; Watanbe, Keiji
2010-01-01
Elastic electromagnetic form factors of nucleons are investigated both for the time-like and the space-like momentums by using the unsubtracted dispersion relation with QCD constraints. It is shown that the calculated form factors reproduce the experimental data reasonably well; they agree with recent experimental data for the neutron magnetic form factors for the space-like data obtained by the CLAS collaboration and are compatible with the ratio of the electric and magnetic form factors for the time-like momentum obtained by the BABAR collaboration.
Analytical evaluation of atomic form factors: application to Rayleigh scattering
Safari, L; Amaro, P; Jänkälä, K; Fratini, F
2014-01-01
Atomic form factors are widely used for the characterization of targets and specimens, from crystallography to biology. By using recent mathematical results, here we derive an analytical expression for the atomic form factor within the independent particle model constructed from nonrelativistic screened hydrogenic wavefunctions. The range of validity of this analytical expression is checked by comparing the analytically obtained form factors with the ones obtained within the Hartee-Fock method. As an example, we apply our analytical expression for the atomic form factor to evaluate the differential cross section for Rayleigh scattering off neutral atoms.
Generalized vector form factors of the pion in a chiral quark model
Broniowski, Wojciech
2008-01-01
Generalized vector form factors of the pion, related to the moments of the generalized parton distribution functions, are evaluated in the Nambu--Jona-Lasinio model with the Pauli-Villars regularization. The lowest moments (the electromagnetic and the gravitational form factors) are compared to recent lattice data, with fair agreement. Predictions for higher-order moments are also made. Relevant features of the generalized form factors in the chiral quark models are highlighted and the role of the QCD evolution for the higher-order GFFs is stressed.
Complement Factor B Mutations in Atypical Hemolytic Uremic Syndrome—Disease-Relevant or Benign?
Marinozzi, Maria Chiara; Vergoz, Laura; Rybkine, Tania; Ngo, Stephanie; Bettoni, Serena; Pashov, Anastas; Cayla, Mathieu; Tabarin, Fanny; Jablonski, Mathieu; Hue, Christophe; Smith, Richard J.; Noris, Marina; Halbwachs-Mecarelli, Lise; Donadelli, Roberta; Fremeaux-Bacchi, Veronique
2014-01-01
Atypical hemolytic uremic syndrome (aHUS) is a genetic ultrarare renal disease associated with overactivation of the alternative pathway of complement. Four gain-of-function mutations that form a hyperactive or deregulated C3 convertase have been identified in Factor B (FB) ligand binding sites. Here, we studied the functional consequences of 10 FB genetic changes recently identified from different aHUS cohorts. Using several tests for alternative C3 and C5 convertase formation and regulation, we identified two gain-of-function and potentially disease-relevant mutations that formed either an overactive convertase (M433I) or a convertase resistant to decay by FH (K298Q). One mutation (R178Q) produced a partially cleaved protein with no ligand binding or functional activity. Seven genetic changes led to near-normal or only slightly reduced ligand binding and functional activity compared with the most common polymorphism at position 7, R7. Notably, none of the algorithms used to predict the disease relevance of FB mutations agreed completely with the experimental data, suggesting that in silico approaches should be undertaken with caution. These data, combined with previously published results, suggest that 9 of 15 FB genetic changes identified in patients with aHUS are unrelated to disease pathogenesis. This study highlights that functional assessment of identified nucleotide changes in FB is mandatory to confirm disease association. PMID:24652797
Relevance of Educational Factors in the Treatment of Pancreatic Cancer
Dan Silviu VERZEA
2012-04-01
Full Text Available Introduction: radical pancreatic resections are the only chance to cure a pancreatic cancer, if the tumor is in an early stage of development. The results of the surgical teams have constantly improved in time, in terms of survival and a good quality of life. Unfortunately, only a small part of the patients benefit from surgical interventions. The causes of this phenomenon are complex, educational factors playing an important role. Material and Methods: 44 patients with pancreatoduodenectomy, operated between 2005 and 2008 were divided in 2 groups. Several parameters were recorded, including age, sex, level of education and place of origin, associated diabetes mellitus, these being studied in relation with the postoperative morbidity and mortality. Results: the morbidity after operation was 65,90%, and the mortality – 6,81%. The level of education, age, socioeconomic status, the presence of diabetes mellitus did not significantly influence the morbidity and the mortality after pancreatoduodenectomy. Conclusions: the postoperative morbidity and mortality are more incidental in small medical centers, but their values are acceptable, if compared with the data from the literature. Excluding the potential patients candidates for radical surgery because they are old or they have poor economic status is not a justified attitude. Education of the patients, medical stuff and surgeons is very important and it can raise the number of healed cases and could change the perception on pancreatic cancer.
Complementary feeding: clinically relevant factors affecting timing and composition.
Krebs, Nancy F; Hambidge, K Michael
2007-02-01
Exclusive breastfeeding for the first 6 mo of life followed by optimal complementary feeding are critical public health measures for reducing and preventing morbidity and mortality in young children. Clinical factors, such as birth weight, prematurity, and illness, that affect the iron and zinc requirements of younger infants are discussed. Maternal diet and nutritional status do not have a strong effect on the mineral content of human milk, but physiologic changes in milk and the infants' status determine the dependence of the infant on complementary foods in addition to human milk to meet iron and zinc requirements after 6 mo. The nature of zinc absorption, which is suitably characterized by saturation response modeling, dictates that plant-based diets, which are low in zinc, are associated with low absolute daily absorbed zinc, which is inadequate to meet requirements. Foods with a higher zinc content, such as meats, are much more likely to be sufficient to meet dietary requirements. Current plant-based complementary feeding patterns for older fully breastfed infants in both developed and developing countries pose a risk of zinc deficiency. The strong rationale for the potential benefits of providing meat as an early complementary food, and the examples of successful intervention programs, provide potent incentives to pursue broader implementation programs, with concurrent rigorous evaluation of both efficacy and effectiveness.
Identifying the Relevant Factors in Newspaper Advertising Effectiveness
Cristóbal Benavides
2014-01-01
Full Text Available Este estudio explora varios factores con el fin de establecer cuáles son losmás importantes en motivar a los lectores de periódicos locales a comprar,visitar tiendas y buscar información adicional acerca de los productos oservicios promovidos en los anuncios. El comportamiento durante el pro-ceso de compra es consecuencia de una compleja interacción de dimen-siones culturales, sociales, personales y psicológicas. Este proceso –el cualse produce antes de la acción– tiene implicaciones relevantes y los depar-tamentos de mercadeo deben prestar atención a ello. Una serie de hipóte-sis basadas en la forma como la publicidad atrae a los consumidores y encómo afecta la toma de decisiones al momento de la compra fueron puestasa prueba usando una encuesta que fue administrada a una muestra de 1.333personas encuestadas en Chile. También se realizó un análisis discriminan-te para averiguar por qué algunos lectores de periódicos se ven motivadosa comprar bienes o servicios, visitar una tienda o buscar más información.Los resultados muestran que el atractivo de la oferta anunciada es el factormás importante para explicar el comportamiento posterior del consumidor.
Farrand, W. H.; Lane, M. D.
2002-01-01
The reflectance and emissivity spectra of palagonite tuffs formed in sub-glacial environments are compared with those formed in liquid water environments. The relevance to palagonites produced by water-magma interactions on Mars is discussed. Additional information is contained in the original extended abstract.
Clinical relevance of "withdrawal therapy" as a form of hormonal manipulation for breast cancer
Robertson John FR
2011-09-01
Full Text Available Abstract Background It has been shown in in-vitro experiments that "withdrawal" of tamoxifen inhibits growth of tumor cells. However, evidence is scarce when this is extrapolated into clinical context. We report our experience to verify the clinical relevance of "withdrawal therapy". Methods Breast cancer patients since 1998 who fulfilled the following criteria were selected from the departmental database and the case-notes were retrospectively reviewed: (1 estrogen receptor positive, operable primary breast cancer in elderly (age > 70 years, locally advanced or metastatic breast cancer; (2 disease deemed suitable for treatment by hormonal manipulation; (3 disease assessable by UICC criteria; (4 received "withdrawal" from a prior endocrine agent as a form of therapy; (5 on "withdrawal therapy" for ≥ 6 months unless they progressed prior. Results Seventeen patients with median age of 84.3 (53.7-92.5 had "withdrawal therapy" as second to tenth line of treatment following prior endocrine therapy using tamoxifen (n = 10, an aromatase inhibitor (n = 5, megestrol acetate (n = 1 or fulvestrant (n = 1. Ten patients (58.8% had clinical benefit (CB (complete response/partial response/stable disease ≥ 6 months with a median duration of Clinical Benefit (DoCB of 10+ (7-27 months. Two patients remain on "withdrawal therapy" at the time of analysis. Conclusion "Withdrawal therapy" appears to produce sustained CB in a significant proportion of patients. This applies not only to "withdrawal" from tamoxifen, but also from other categories of endocrine agents. "Withdrawal" from endocrine therapy is, therefore, a viable intercalating option between endocrine agents to minimise resistance and provide additional line of therapy. It should be considered as part of the sequencing of endocrine therapy.
Relevant Factors of Estrogen Changes of Myopia in Adolescent Females
Juan-Fen Gong; Hong-Li Xie; Xin-Jie Mao; Xue-Bo Zhu; Zuo-Kai Xie; Hai-Hong Yang; Yang Gao
2015-01-01
Background:Gender is one of the risk factors accounting for the high prevalence of adolescent myopia.Considerable research results have shown that myopia incidence of female is higher than that of male.This study aimed to analyze the correlation between ocular parameters and serum estrogen level and to investigate the vision changes along with estrogen change in menstrual cycle of adolescent females.Methods:A total of 120 young females aged between 15 and 16 years,diagnosed with myopia were recruited.Spherical lens,cylindrical lens,axis,interpupillary distance (IPD),and vision in each tested eye of the same subject were measured by automatic optometry and comprehensive optometry,with repetition of all measurements in the menstrual cycle of the 2nd or 3rd days,14th days,and 282 days,respectively.Serum estradiol (E2) levels were assayed by chemiluminescence immunoassay at the same three times points of the menstrual cycle mentioned above.Results:In young females with myopia,the spherical lens showed a statistically significant difference among all different time in menstrual cycle (all P ＜ 0.0001).The cylindrical lens,axis,and IPD were changed significantly during the menstrual cycle (P ＜ 0.05).The vision of the three different time points in menstrual cycle had a significant difference (x2 =6.35,P =0.042).The vision during the 14th and 28th day was higher compared to that on the 2nd or 3rd days (P =0.021).Serum E2 levels were significantly different at different time points in menstrual cycle (P ＜ 0.05).E2 levels reached its maximum value on the 142 day and the minimum value on the 2nd or 3rd day.Conclusions:In adolescent females,the spherical lens and other related ocular parameters vary sensitively with different levels of E2 in menstrual cycle.Vision in late menstrual stage is significantly higher than that in premenstrual stage.
Form factors in an algebraic model of the nucleon
Bijker, R
1995-01-01
We study the electromagnetic form factors of the nucleon in a collective model of baryons. In an algebraic approach to hadron structure, we derive closed expressions for both elastic and transition form factors, and consequently for the helicity amplitudes that can be measured in electro- and photoproduction.
Relativistic quark model for the Omega- electromagnetic form factors
G. Ramalho, K. Tsushima, Franz Gross
2009-08-01
We compute the Omega- electromagnetic form factors and the decuplet baryon magnetic moments using a quark model application of the Covariant Spectator Theory. Our predictions for the Omega- electromagnetic form factors can be tested in the future by lattice QCD simulations at the physical strange quark mass.
A relativistic quark model for the Omega- electromagnetic form factors
Ramalho, G; Gross, Franz
2009-01-01
We compute the Omega- electromagnetic form factors and the decuplet baryon magnetic moments using a quark model application of the Covariant Spectator Theory. Our predictions for the Omega- electromagnetic form factors can be tested in the future by lattice QCD simulations at the physical strange quark mass.
Molecular form factors in X-ray crystallography
Groenewegen, P.P.M.; Feil, D.
1969-01-01
The calculation of molecular form factors from ab initio molecular electronic wavefunctions is discussed, and a scheme for application to X-ray diffraction structure analysis is given. The method is used to calculate the form factor of the NH+4 molecular ion from three accurate molecular wavefunctio
The charge form factor of pseudoscalar mesons in a relativistic constituent quark model
Cardarelli, F.; Pace, E. [Univ. of Rome, Roma (Italy); Grach, I.L. [Inst. of Theoretical and Experimental Physics, Moscow (Russian Federation)] [and others
1994-04-01
The charge form factor of pseudoscalar mesons has been investigated in the light-cone formalism, up to Q{sup 2} relevant to CEBAF energies. The consequences of adopting the meson wave functions generated through the Godfrey-Isgur q{bar q} potential, which reproduces the mass spectra, are discussed.
Nonperturbative study of the 't Hooft-Polyakov monopole form factors
Rajantie, Arttu
2011-01-01
The mass and interactions of a quantum 't Hooft-Polyakov monopole are measured nonperturbatively using correlation functions in lattice Monte Carlo simulations. A method of measuring the form factors for interactions between the monopole and fundamental particles, such as the photon, is demonstrated. These quantities are potentially of experimental relevance in searches for magnetic monopoles.
Nonperturbative study of the 't Hooft-Polyakov monopole form factors
Rajantie, Arttu; Weir, David J.
2012-01-01
The mass and interactions of a quantum ’t Hooft-Polyakov monopole are measured nonperturbatively using correlation functions in lattice Monte Carlo simulations. A method of measuring the form factors for interactions between the monopole and fundamental particles, such as the photon, is demonstrated. These quantities are potentially of experimental relevance in searches for magnetic monopoles.
Flavor decomposition of the nucleon electromagnetic form factors
Qattan, I A
2012-01-01
Background: The spatial distribution of charge and magnetization in the proton and neutron are encoded in the nucleon electromagnetic form factors. The form factors are all approximated by a simple dipole function, normalized to the charge or magnetic moment of the nucleon. The differences between the proton and neutron form factors and the deviation of GEn from zero are sensitive to the difference between up- and down-quark contributions to the form factors. Methods: We combine recent measurements of the neutron form factors with updated extractions of the proton form factors, accounting for two-photon exchange corrections and including an estimate of the uncertainties for all of the form factors to obtain a complete set of measurements up to Q^2 approximately 4 (GeV/c)^2. We use this to extract the up- and down-quark contributions which we compare to recent fits and calculations. Results: We find a large differences between the up- and down-quark contributions to G_E and G_M, implying significant flavor dep...
Extraction of the isovector magnetic form factor of the nucleon at zero momentum
Alexandrou, Constantia; Koutsou, Giannis; Ottnad, Konstantin; Petschlies, Marcus
2014-01-01
The extraction of the magnetic form factor of the nucleon at zero momentum transfer is usually performed by adopting a parametrization for its momentum dependence and fitting the results obtained at finite momenta. We present position space methods that rely on taking the derivative of relevant correlators to extract directly the magnetic form factor at zero momentum without the need to assume a functional form for its momentum dependence. These methods are explored on one ensemble using $N_f=2+1+1$ Wilson twisted mass fermions.
Isospin violation in the vector form factors of the nucleon
Kubis, B; Kubis, Bastian; Lewis, Randy
2006-01-01
A quantitative understanding of isospin violation is an increasingly important ingredient for the extraction of the nucleon's strange vector form factors from experimental data. We calculate the isospin violating electric and magnetic form factors in chiral perturbation theory to leading and next-to-leading order respectively, and we extract the low-energy constants from resonance saturation. Uncertainties are dominated largely by limitations in the current knowledge of some vector meson couplings. The resulting bounds on isospin violation are sufficiently precise to be of value to on-going experimental studies of the strange form factors.
A note on connected formula for form factors
He, Song
2016-01-01
In this note we study the connected prescription, originally derived from Witten's twistor string theory, for tree-level form factors in ${\\cal N}=4$ super-Yang-Mills theory. The construction is based on the recently proposed four-dimensional scattering equations with $n$ massless on-shell states and one off-shell state, which we expect to work for form factors of general operators. To illustrate the universality of the prescription, we propose compact formulas for super form factors with chiral stress-tensor multiplet operator, and bosonic ones with scalar operators ${\\rm Tr}(\\phi^m)$ for arbitrary $m$.
The structure of the nucleon: Elastic electromagnetic form factors
Punjabi, V. [Norfolk State University, Norfolk, VA (United States); Perdrisat, C.F.; Carlson, C.E. [The College of William and Mary, Williamsburg, VA (United States); Jones, M.K. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Brash, E.J. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Christopher Newport University, Newport News, VA (United States)
2015-07-15
Precise proton and neutron form factor measurements at Jefferson Lab, using spin observables, have recently made a significant contribution to the unraveling of the internal structure of the nucleon. Accurate experimental measurements of the nucleon form factors are a test-bed for understanding how the nucleon's static properties and dynamical behavior emerge from QCD, the theory of the strong interactions between quarks. There has been enormous theoretical progress, since the publication of the Jefferson Lab proton form factor ratio data, aiming at reevaluating the picture of the nucleon. We will review the experimental and theoretical developments in this field and discuss the outlook for the future. (orig.)
Longitudinal vector form factors in weak decays of nuclei
Simkovic, F; Krivoruchenko, M I
2015-01-01
The longitudinal form factors of the weak vector current of particles with spin $ J = 1/2 $ and isospin $ I = 1/2 $ are determined by the mass difference and the charge radii of members of the isotopic doublets. The most promising reactions to measure these form factors are the reactions with large momentum transfers involving the spin-1/2 isotopic doublets with a maximum mass splitting. Numerical estimates of longitudinal form factors are given for nucleons and eight nuclear spin-1/2 isotopic doublets.
Light-cone sum rule approach for Baryon form factors
Offen, Nils
2016-01-01
We present the state-of-the-art of the light-cone sum rule approach to Baryon form factors. The essence of this approach is that soft Feynman contributions are calculated in terms of small transverse distance quantities using dispersion relations and duality. The form factors are thus expressed in terms of nucleon wave functions at small transverse separations, called distribution amplitudes, without any additional parameters. The distribution amplitudes, therefore, can be extracted from the comparison with the experimental data on form factors and compared to the results of lattice QCD simulations.
A note on connected formula for form factors
He, Song; Liu, Zhengwen
2016-12-01
In this note we study the connected prescription, originally derived from Witten's twistor string theory, for tree-level form factors in N = 4 super-Yang-Mills theory. The construction is based on the recently proposed four-dimensional scattering equations with n massless on-shell states and one off-shell state, which we expect to work for form factors of general operators. To illustrate the universality of the prescription, we propose compact formulas for super form factors with chiral stress-tensor multiplet operator, and bosonic ones with scalar operators Tr( ϕ m ) for arbitrary m.
Light-Cone Sum Rule Approach for Baryon Form Factors
Offen, Nils
2016-10-01
We present the state-of-the-art of the light-cone sum rule approach to Baryon form factors. The essence of this approach is that soft Feynman contributions are calculated in terms of small transverse distance quantities using dispersion relations and duality. The form factors are thus expressed in terms of nucleon wave functions at small transverse separations, called distribution amplitudes, without any additional parameters. The distribution amplitudes, therefore, can be extracted from the comparison with the experimental data on form factors and compared to the results of lattice QCD simulations.
Roaming form factors for the tricritical to critical Ising flow
Horvath, D X; Takacs, G
2016-01-01
We study the massless flows described by the staircase model introduced by Al.B. Zamolodchikov through the analytic continuation of the sinh-Gordon S-matrix, focusing on the renormalisation group flow from the tricritical to the critical Ising model. We show that the properly defined roaming limits of certain sinh-Gordon form factors are identical to the form factors of the order and disorder operators for the massless flow. As a by-product, we also construct form factors for a semi-local field in the sinh-Gordon model, which can be associated with the twist field in the ultraviolet limiting free massless bosonic theory.
Pion Electromagnetic Form Factor at Lower and Higher Momentum Transfer
de Melo, J P B C; Tsushima, Kazuo
2016-01-01
The pion electromagnetic form factor is calculated at lower and higher momentum transfer in order to explore constituent quark models and the differences among those models. In particular, the light-front constituent quark model is utilized here to calculate the pion electromagnetic form factor at lower and higher energies. The matrix elements of the electromagnetic current, are calculated with both "plus" and "minus" components of the electromagnetic current in the light-front. Further, the electromagnetic form factor is compared with other models in the literature and experimental data.
Normalization Of Thermal-Radiation Form-Factor Matrix
Tsuyuki, Glenn T.
1994-01-01
Report describes algorithm that adjusts form-factor matrix in TRASYS computer program, which calculates intraspacecraft radiative interchange among various surfaces and environmental heat loading from sources such as sun.
nf2 contributions to fermionic four-loop form factors
Lee, Roman N.; Smirnov, Alexander V.; Smirnov, Vladimir A.; Steinhauser, Matthias
2017-07-01
We compute the four-loop contributions to the photon quark and Higgs quark form factors involving two closed fermion loops. We present analytical results for all nonplanar master integrals of the two nonplanar integral families which enter our calculation.
Proton Form Factors Measurements in the Time-Like Region
Anulli, F.; /Frascati
2007-10-22
I present an overview of the measurement of the proton form factors in the time-like region. BABAR has recently measured with great accuracy the e{sup +}e{sup -} {yields} p{bar p} reaction from production threshold up to an energy of {approx} 4.5 GeV, finding evidence for a ratio of the electric to magnetic form factor greater than unity, contrary to expectation. In agreement with previous measurements, BABAR confirmed the steep rise of the magnetic form factor close to the p{bar p} mass threshold, suggesting the possible presence of an under-threshold N{bar N} vector state. These and other open questions related to the nucleon form factors both in the time-like and space-like region, wait for more data with different experimental techniques to be possibly solved.
Electromagnetic form factors of baryons in an algebraic approach
Bijker, R. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510 Mexico D.F. (Mexico); Leviatan, A. [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)
1999-07-01
We present a simultaneous analysis of elastic and transition form factors of the nucleon. The calculations are performed in the framework of an algebraic model of baryons. Effects of meson cloud couplings are considered. (Author)
Electromagnetic form factors of baryons in an algebraic approach
Bijker, R
1999-01-01
We present a simultaneous analysis of elastic and transition form factors of the nucleon. The calculations are performed in the framework of an algebraic model of baryons. Effects of meson cloud couplings are considered.
The connected prescription for form factors in twistor space
Brandhuber, Andreas; Panerai, Rodolfo; Spence, Bill; Travaglini, Gabriele
2016-01-01
We propose a connected prescription formula in twistor space for all tree-level form factors of the stress tensor multiplet operator in $\\mathcal{N}=4$ super Yang-Mills, which is a generalisation of the expression of Roiban, Spradlin and Volovich for superamplitudes. By introducing link variables, we show that our formula is identical to the recently proposed four-dimensional scattering equations for form factors. Similarly to the case of amplitudes, the link representation of form factors is shown to be directly related to BCFW recursion relations, and is considerably more tractable than the scattering equations. We also discuss how our results are related to a recent Grassmannian formulation of form factors, and comment on a possible derivation of our formula from ambitwistor strings.
Hadronic Form Factors in Asymptotically Free Field Theories
Gross, D. J.; Treiman, S. B.
1974-01-01
The breakdown of Bjorken scaling in asymptotically free gauge theories of the strong interactions is explored for its implications on the large q{sup 2} behavior of nucleon form factors. Duality arguments of Bloom and Gilman suggest a connection between the form factors and the threshold properties of the deep inelastic structure functions. The latter are addressed directly in an analysis of asymptotically free theories; and through the duality connection we are then led to statements about the form factors. For very large q{sup 2} the form factors are predicted to fall faster than any inverse power of q{sup 2}. For the more modest range of q{sup 2} reached in existing experiments the agreement with data is fairly good, though this may well be fortuitous. Extrapolations beyond this range are presented.
Rare $B$ decays using lattice QCD form factors
Horgan, R R; Meinel, S; Wingate, M
2015-01-01
In this write-up we review and update our recent lattice QCD calculation of $B \\to K^*$, $B_s \\to \\phi$, and $B_s \\to K^*$ form factors [arXiv:1310.3722]. These unquenched calculations, performed in the low-recoil kinematic regime, provide a significant improvement over the use of extrapolated light cone sum rule results. The fits presented here include further kinematic constraints and estimates of additional correlations between the different form factor shape parameters. We use these form factors along with Standard Model determinations of Wilson coefficients to give Standard Model predictions for several observables [arXiv:1310.3887]. The modest improvements to the form factor fits lead to improved determinations of $F_L$, the fraction of longitudinally polarized vector mesons, but have little effect on most other observables.
The connected prescription for form factors in twistor space
Brandhuber, A.; Hughes, E.; Panerai, R.; Spence, B.; Travaglini, G.
2016-11-01
We propose a connected prescription formula in twistor space for all tree-level form factors of the stress tensor multiplet operator in {N} = 4 super Yang-Mills, which is a generalisation of the expression of Roiban, Spradlin and Volovich for superamplitudes. By introducing link variables, we show that our formula is identical to the recently proposed four-dimensional scattering equations for form factors. Similarly to the case of amplitudes, the link representation of form factors is shown to be directly related to BCFW recursion relations, and is considerably more tractable than the scattering equations. We also discuss how our results are related to a recent Grassmannian formulation of form factors, and comment on a possible derivation of our formula from ambitwistor strings.
Elastic and transition form factors of the \\Delta(1232)
Segovia, Jorge; Cloët, Ian C; Roberts, Craig D; Schmidt, Sebastian M; Wan, Shaolong
2013-01-01
Predictions obtained with a confining, symmetry-preserving treatment of a vector-vector contact interaction at leading-order in a widely used truncation of QCD's Dyson-Schwinger equations are presented for \\Delta and \\Omega baryon elastic form factors and the \\gamma N -> \\Delta transition form factors. This simple framework produces results that are practically indistinguishable from the best otherwise available, an outcome which highlights that the key to describing many features of baryons and unifying them with the properties of mesons is a veracious expression of dynamical chiral symmetry breaking in the hadron bound-state problem. The following specific results are of particular interest. The \\Delta elastic form factors are very sensitive to m_\\Delta. Hence, given that the parameters which define extant simulations of lattice-regularised QCD produce \\Delta-resonance masses that are very large, the form factors obtained therewith are a poor guide to properties of the \\Delta(1232). Considering the \\Delta-b...
Low energy analysis of the nucleon electromagnetic form factors
Kubis, B; Kubis, Bastian; Meissner, Ulf-G.
2001-01-01
We analyze the electromagnetic form factors of the nucleon to fourth order in relativistic baryon chiral perturbation theory. We employ the recently proposed infrared regularization scheme and show that the convergence of the chiral expansion is improved as compared to the heavy fermion approach. We also discuss the inclusion of vector mesons and obtain an accurate description of all four nucleon form factors for momentum transfer squared up to Q^2 \\simeq 0.4 GeV^2.
Hyperon decay form factors in chiral perturbation theory
Lacour, Andre; Meißner, Ulf-G
2007-01-01
We present a complete calculation of the SU(3)-breaking corrections to the hyperon vector form factors up to O(p^4) in covariant baryon chiral perturbation theory. Partial higher-order contributions are obtained, and we discuss chiral extrapolations of the vector form factor at zero momentum transfer. In addition we derive low-energy theorems for the subleading moments in hyperon decays, the weak Dirac radii and the weak anomalous magnetic moments, up to O(p^4).
Future Perspectives on Baryon Form Factor Measurements with BES III
Schönning, Karin; Li, Cui
2017-03-01
The electromagnetic structure of hadrons, parameterised in terms of electromagnetic form factors, EMFF's, provide a key to the strong interaction. Nucleon EMFF's have been studied rigorously for more than 60 years but the new techniques and larger data samples available at modern facilities have given rise to a renewed interest for the field. Recently, the access to hyperon structure by hyperon time-like EMFF provides an additional dimension. The BEijing Spectrometer (BES III) at the Beijing Electron Positron Collider (BEPC-II) in China is the only running experiment where time-like baryon EMFF's can be studied in the e+e- → BB̅ reaction. The BES III detector is an excellent tool for baryon form factor measurements thanks to its near 4π coverage, precise tracking, PID and calorimetry. All hyperons in the SU(3) spin 1/2 octet and spin 3/2 decuplet are energetically accessible within the BEPC-II energy range. Recent data on proton and Λ hyperon form factors will be presented. Furthermore, a world-leading data sample was collected in 2014-2015 for precision measurements of baryon form factors. In particular, the data will enable a measurement of the relative phase between the electric and the magnetic form factors for Λ and Λc+ and hyperons. The modulus of the phase can be extracted from the hyperon polarisation, which in turn is experimentally accessible via the weak, parity violating decay. Furthermore, from the spin correlation between the outgoing hyperon and antihyperon, the sign of the phase can be extracted. This means that the time-like form factors can be completely determined for the first time. The methods will be outlined and the prospects of the BES III form factor measurements will be given. We will also present a planned upgrade of the BES III detector which is expected to improve future form factor measurements.
Electromagnetic form factors in a collective model of the nucleon
Bijker, R; Leviatan, A
1995-01-01
We study the electromagnetic form factors of the nucleon in a collective model of baryons. Using the algebraic approach to hadron structure, we derive closed expressions for both elastic and transition form factors, and consequently for the helicity amplitudes that can be measured in electro- and photoproduction. Effects of spin-flavor symmetry breaking and of swelling of hadrons with increasing excitation energy are considered.
Electromagnetic form factors in a collective model of the nucleon
Bijker, R.; Iachello, F.; Leviatan, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510 (Mexico)]|[Distrito Federale (Mexico)]|[Center for Theoretical Physics, Sloane Laboratory, Yale University, New Haven, Connecticut 06520-8120 (United States)]|[Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)
1996-10-01
We study the electromagnetic form factors of the nucleon in a collective model of baryons. Using the algebraic approach to hadron structure, we derive closed expressions for both elastic and transition form factors, and consequently for the helicity amplitudes that can be measured in electro- and photoproduction. Effects of spin-flavor symmetry breaking and of swelling of hadrons with increasing excitation energy are considered. {copyright} {ital 1996 The American Physical Society.}
Form Factors for Exclusive Semileptonic $B$--Decays
Kim, C S; Kim, Y G; Lee, K Y; Kim, Jae Kwan; Kim, Yeong Gyun; Lee, Kang Young
1996-01-01
We investigate the form factors for exclusive semileptonic decays of $B$-meson to $D,~D^*$, based on the parton picture and helped by the results of the HQET. We obtain the numerical results for the slope of the Isgur-Wise function, which is consistent with the experimental results, and we extracte the dependences of hadronic form factors on $q^2$ by varying input heavy quark fragmentation function without the nearest pole dominance ansätze.
Form factors and other measures of strangeness in the nucleon
Diehl, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Feldmann, T. [Siegen Univ. (Germany). Theoretische Physik I; Kroll, P. [Bergische Univ., Wuppertal (Germany). Fachbereich Physik
2007-11-15
We discuss the phenomenology of strange-quark dynamics in the nucleon, based on experimental and theoretical results for electroweak form factors and for parton densities. In particular, we construct a model for the generalized parton distribution that relates the asymmetry s(x)- anti s(x) between the longitudinal momentum distributions of strange quarks and antiquarks with the form factor F{sup s}{sub 1}(t), which describes the distribution of strangeness in transverse position space. (orig.)
Electromagnetic form factors of the nucleon. Experiments at MAMI
Ostrick, M. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany)
2006-05-15
Elastic form factors are of fundamental importance for the understanding of microscopic spatial structures. In case of the proton and the neutron, charge and magnetic form factors can be studied in elastic electron scattering. Techniques to accelerate polarised continuous electron beams, the availability of polarised targets as well as modern concepts and instrumentation for coincidence experiments and recoil polarimetry had an enormous impact on these measurements. The developments and experiments at the Mainz Microtron MAMI will be discussed in a general context. (orig.)
Online Soil Science Lesson 3: Soil Forming Factors
This lesson explores the five major factors of soil formation, namely: 1) climate; 2) organisms; 3) time; 4) topography; and 5) parent material and their influence in forming soil. The distinction between active and passive factors, moisture and temperature regimes, organism and topographic influen...
On a four-loop form factor in N=4
Boels, Rutger H; Yang, Gang
2016-01-01
We report on progress toward computing a four-loop supersymmetric form factor in maximally supersymmetric Yang-Mills theory. A representative example particle content from the involved supermultiplets is a stress-tensor operator with two on-shell gluons. In previous work, the integrand for this form factor was obtained using color-kinematic duality in a particularly simple form. Here the result of applying integration-by-parts identities is discussed and cross-checks of the result is performed. Rational IBP relations and their reduction are introduced as a potentially useful aide.
Factors Relevant to Recruitment/Retention of Minorities in Science Professions.
Rowe, Mary Budd
This paper discusses some of the factors that may be relevant to recruitment/retention of minorities into professions. It is based on two assumptions: (1) the job potential in science professions is especially good for minorities; and (2) parity with respect to minorities in science professions is an acceptable goal. Certain factors influencing…
Dispersion-theoretical analysis of the nucleon electromagnetic form factors
Belushkin, M.
2007-09-29
The structure of the proton and the neutron is of fundamental importance for the study of the strong interaction dynamics over a wide range of momentum transfers. The nucleon form factors encode information on the internal structure of the nucleon as probed by the electromagnetic interaction, and, to a certain extent, reflect the charge and magnetisation distributions within the proton and the neutron. In this thesis we report on our investigation of the electromagnetic form factors of the proton and the neutron with dispersion relation techniques, including known experimental input on the {pi}{pi}, K anti K and the {rho}{pi} continua and perturbative QCD constraints. We include new experimental data on the pion form factor and the nucleon form factors in our simultaneous analysis of all four form factors in both the space- and the timelike regions for all momentum transfers, and perform Monte- Carlo sampling in order to obtain theoretical uncertainty bands. Finally, we discuss the implications of our results on the pion cloud of the nucleon, the nucleon radii and the Okubo-Zweig-Iizuka rule, and present our results of a model-independent approach to estimating two-photon effects in elastic electron-proton scattering. (orig.)
Possible diquark signatures in the elastic nucleon form factors
Cates, Gordon
2013-10-01
There has been considerable interest in the elastic nucleon form factors ever since the discovery that the proton form-factor ratio, GEp /GMp , decreases nearly linearly above roughly Q2 = 1 GeV2 . More recent measurements of the neutron form-factor ratio, GEn /GMn , up to 3 . 4 GeV2 have made it possible to constrain calculations using both proton and neutron data in the Q2 regime where the interesting behavior of the proton was first observed. Calculations based on QCD's Dyson-Schwinger equations, as well as certain relativistic constituent quark models, suggest that the observed behavior is related to the importance of diquark degrees of freedom. To understand this connection, it is particularly useful to consider the flavor-separated form factors, which can be extracted by combining proton and neutron data, and assuming charge symmetry. Distinctly different behavior is seen for the u - and d - quarks. The behaviors of the different quark flavors and the connection to diquarks can also be understood using naive scaling arguments, although this approach has yet to be made more rigorous. This talk will discuss how measurements of the nucleon form factors at high Q2 provides a rich opportunity to better understand the structure of the nucleon.
Dispersion-theoretical analysis of the nucleon electromagnetic form factors
Belushkin, M.
2007-09-29
The structure of the proton and the neutron is of fundamental importance for the study of the strong interaction dynamics over a wide range of momentum transfers. The nucleon form factors encode information on the internal structure of the nucleon as probed by the electromagnetic interaction, and, to a certain extent, reflect the charge and magnetisation distributions within the proton and the neutron. In this thesis we report on our investigation of the electromagnetic form factors of the proton and the neutron with dispersion relation techniques, including known experimental input on the {pi}{pi}, K anti K and the {rho}{pi} continua and perturbative QCD constraints. We include new experimental data on the pion form factor and the nucleon form factors in our simultaneous analysis of all four form factors in both the space- and the timelike regions for all momentum transfers, and perform Monte- Carlo sampling in order to obtain theoretical uncertainty bands. Finally, we discuss the implications of our results on the pion cloud of the nucleon, the nucleon radii and the Okubo-Zweig-Iizuka rule, and present our results of a model-independent approach to estimating two-photon effects in elastic electron-proton scattering. (orig.)
Information content of the weak-charge form factor
Reinhard, P -G; Nazarewicz, W; Agrawal, B K; Paar, N; Rocca-Maza, X
2013-01-01
Parity-violating electron scattering provides a model-independent determination of the nuclear weak-charge form factor that has widespread implications across such diverse areas as fundamental symmetries, nuclear structure, heavy-ion collisions, and neutron-star structure. We assess the impact of precise measurements of the weak-charge form factor of ${}^{48}$Ca and ${}^{208}$Pb on a variety of nuclear observables, such as the neutron skin and the electric-dipole polarizability. We use the nuclear Density Functional Theory with several accurately calibrated non-relativistic and relativistic energy density functionals. To assess the degree of correlation between nuclear observables and to explore systematic and statistical uncertainties on theoretical predictions, we employ the chi-square statistical covariance technique. We find a strong correlation between the weak-charge form factor and the neutron radius, that allows for an accurate determination of the neutron skin of neutron-rich nuclei. We determine the...
Nucleon electromagnetic form factors from the covariant Faddeev equation
Eichmann, G.
2011-07-01
We compute the electromagnetic form factors of the nucleon in the Poincaré-covariant Faddeev framework based on the Dyson-Schwinger equations of QCD. The general expression for a baryon’s electromagnetic current in terms of three interacting dressed quarks is derived. Upon employing a rainbow-ladder gluon-exchange kernel for the quark-quark interaction, the nucleon’s Faddeev amplitude and electromagnetic form factors are computed without any further truncations or model assumptions. The form-factor results show clear evidence of missing pion-cloud effects below a photon momentum transfer of ˜2GeV2 and in the chiral region, whereas they agree well with experimental data at higher photon momenta. Thus, the approach reflects the properties of the nucleon’s quark core.
Form factor ratio from unpolarized elastic electron-proton scattering
Pacetti, Simone; Tomasi-Gustafsson, Egle
2016-11-01
A reanalysis of unpolarized electron-proton elastic scattering data is done in terms of the electric to magnetic form factor squared ratio. This observable is in principle more robust against experimental correlations and global normalizations. The present analysis shows indeed that it is a useful quantity that contains reliable and coherent information. The comparison with the ratio extracted from the measurement of the longitudinal to transverse polarization of the recoil proton in polarized electron-proton scattering shows that the results are compatible within the experimental errors. Limits are set on the kinematics where the physical information on the form factors can be safely extracted. The results presented in this work bring a decisive piece of information to the controversy on the deviation of the proton form factors from the dipole dependence.
Zero modes method and form factors in quantum integrable models
S. Pakuliak
2015-04-01
Full Text Available We study integrable models solvable by the nested algebraic Bethe ansatz and possessing GL(3-invariant R-matrix. Assuming that the monodromy matrix of the model can be expanded into series with respect to the inverse spectral parameter, we define zero modes of the monodromy matrix entries as the first nontrivial coefficients of this series. Using these zero modes we establish new relations between form factors of the elements of the monodromy matrix. We prove that all of them can be obtained from the form factor of a diagonal matrix element in special limits of Bethe parameters. As a result we obtain determinant representations for form factors of all the entries of the monodromy matrix.
Kaon semileptonic decay form factors with HISQ valence quarks
Gamiz, E; Bazavov, A; Bernard, C; Bouchard, C; DeTar, C; Du, D; El-Khadra, A X; Foley, J; Freeland, E D; Gottlieb, Steven; Heller, U M; Kim, J; Kronfeld, A S; Laiho, J; Levkova, L; Mackenzie, P B; Neil, E T; Oktay, M B; Qiu, Si-Wei; Simone, J N; Sugar, R; Toussaint, D; Van de Water, R S; Zhou, R
2012-01-01
We report on the status of our kaon semileptonic form factor calculations using the highly-improved staggered quark (HISQ) formulation to simulate the valence fermions. We present results for the form factor f_+^{K \\pi}(0) on the asqtad N_f=2+1 MILC configurations, discuss the chiral-continuum extrapolation, and give a preliminary estimate of the total error. We also present a more preliminary set of results for the same form factor but with the sea quarks also simulated with the HISQ action; these results include data at the physical light quark masses. The improvements that we expect to achieve with the use of the HISQ configurations and simulations at the physical quark masses are briefly discussed.
Two-Loop SL(2) Form Factors and Maximal Transcendentality
Loebbert, Florian; Wilhelm, Matthias; Yang, Gang
2016-01-01
Form factors of composite operators in the SL(2) sector of N=4 SYM theory are studied up to two loops via the on-shell unitarity method. The non-compactness of this subsector implies the novel feature and technical challenge of an unlimited number of loop momenta in the integrand's numerator. At one loop, we derive the full minimal form factor to all orders in the dimensional regularisation parameter. At two loops, we construct the complete integrand for composite operators with an arbitrary number of covariant derivatives, and we obtain the remainder functions as well as the dilatation operator for composite operators with up to three covariant derivatives. The remainder functions reveal curious patterns suggesting a hidden maximal uniform transcendentality for the full form factor. Finally, we speculate about an extension of these patterns to QCD.
Form factor and width of a quantum string
Rajantie, Arttu; Weir, David J
2012-01-01
In the Yang-Mills theory, the apparent thickness of the confining string is known to grow logarithmically when its length increases. The same logarithmic broadening also happens to strings in other quantum field theories and domain walls in statistical physics models. Even in quantum field theories, the observables used to measure and characterise this phenomenon are largely borrowed from statistical physics. In this paper, we describe it using the string form factor, which is a meaningful quantum observable, and show how the form factor can be obtained from field correlation functions calculated in lattice Monte Carlo simulations. We apply this method to 2+1-dimensional scalar theory in the strong coupling limit, where it is equivalent to the 3D Ising model, and through duality also to 2+1-dimensional $\\mathbb{Z}_2$ gauge theory. We measure the string form factor by simulating the Ising model, and demonstrate that it displays the same logarithmic broadening as statistical physics observables.
The Proton Form Factor Ratio Measurements at Jefferson Lab
Punjabi, Vina A. [Norfolk State University, Norfolk, VA (United States); Perdrisat, Charles F. [William and Mary College, Williamsburg, VA (United States)
2014-03-01
The ratio of the proton form factors, G{sub Ep}/G{sub Mp}, has been measured from Q{sup 2} of 0.5 GeV{sup 2} to 8.5 GeV{sup 2}, at the Jefferson Laboratory, using the polarization transfer method. This ratio is extracted directly from the measured ratio of the transverse and longitudinal polarization components of the recoiling proton in elastic electron-proton scattering. The discovery that the proton form factor ratio measured in these experiments decreases approximately linearly with four-momentum transfer, Q{sup 2}, for values above ~1 GeV{sup 2}, is one of the most significant results to come out of JLab. These results have had a large impact on progress in hadronic physics; and have required a significant rethinking of nucleon structure. The increasingly common use of the double-polarization technique to measure the nucleon form factors, in the last 15 years, has resulted in a dramatic improvement of the quality of all four nucleon electromagnetic form factors, G{sub Ep}, G{sub Mp}, G{sub En} and G{sub Mn}. There is an approved experiment at JLab, GEP(V), to continue the ratio measurements to 12 GeV{sup 2}. A dedicated experimental setup, the Super Bigbite Spectrometer (SBS), will be built for this purpose. It will be equipped with a focal plane polarimeter to measure the polarization of the recoil protons. The scattered electrons will be detected in an electromagnetic calorimeter. In this presentation, I will review the status of the proton elastic electromagnetic form factors and discuss a number of theoretical approaches to describe nucleon form factors.
Master integrals for the four-loop Sudakov form factor
Rutger H. Boels
2016-01-01
Full Text Available The light-like cusp anomalous dimension is a universal function in the analysis of infrared divergences. In maximally (N=4 supersymmetric Yang–Mills theory (SYM in the planar limit, it is known, in principle, to all loop orders. The non-planar corrections are not known in any theory, with the first appearing at the four-loop order. The simplest quantity which contains this correction is the four-loop two-point form factor of the stress tensor multiplet. This form factor was largely obtained in integrand form in a previous work for N=4 SYM, up to a free parameter. In this work, a reduction of the appearing integrals obtained by solving integration-by-parts (IBP identities using a modified version of Reduze is reported. The form factor is shown to be independent of the remaining parameter at integrand level due to an intricate pattern of cancellations after IBP reduction. Moreover, two of the integral topologies vanish after reduction. The appearing master integrals are cross-checked using independent algebraic-geometry techniques explored in the Mint package. The latter results provide the basis of master integrals applicable to generic form factors, including those in Quantum Chromodynamics. Discrepancies between explicitly solving the IBP relations and the MINT approach are highlighted. Remaining bottlenecks to completing the computation of the four-loop non-planar cusp anomalous dimension in N=4 SYM and beyond are identified.
Nucleon form factors and O(a) Improvement
Capitani, S; Horsley, R; Klaus, B; Oelrich, H; Perlt, H; Petters, D; Pleiter, D; Rakow, P E L; Schierholz, G; Schiller, A; Stephenson, P W
1999-01-01
Nucleon form factors have been extensively studied both experimentally and theoretically for many years. We report here on new results of a high statistics quenched lattice QCD calculation of vector and axial-vector nucleon form factors at low momentum transfer within the Symanzik improvement programme. The simulations are performed at three kappa and three beta values allowing first an extrapolation to the chiral limit and then an extrapolation in the lattice spacing to the continuum limit. The computations are all fully non-perturbative. A comparison with experimental results is made.
Exploring strange nucleon form factors on the lattice
Babich, Ronald; Clark, Michael A; Fleming, George T; Osborn, James C; Rebbi, Claudio; Schaich, David
2010-01-01
We discuss techniques for evaluating sea quark contributions to hadronic form factors on the lattice and apply these to an exploratory calculation of the strange electromagnetic, axial, and scalar form factors of the nucleon. We employ the Wilson gauge and fermion actions on an anisotropic 24^3 x 64 lattice, probing a range of momentum transfer with Q^2 _0. We discuss the unique systematic uncertainties affecting the latter quantity relative to the continuum, as well as prospects for improving future determinations with Wilson-like fermions.
Vector and Axial Form Factors Applied to Neutrino Quasielastic Scattering
Budd, H; Arrington, J
2005-01-01
We calculate the quasielastic cross sections for neutrino scattering on nucleons using up to date fits to the nucleon elastic electromagnetic form factors GEp, GEn, GMp, GMn, and weak form factors. We show the extraction of Fa for neutrino experiments. We show how well \\minerva, a new approved experiment at FNAL, can measure Fa. We show the that Fa has a different contribution to the anti-neutrino cross section, and how the anti-neutrino data can be used to check Fa extracted from neutrino scattering.
Reanalysis of Rosenbluth measurements of the proton form factors
Gramolin, Alexander; Nikolenko, Dmitry
2017-01-01
We have reanalyzed the elastic electron-proton scattering data from SLAC experiments E140 and NE11. This work was motivated by recent progress in calculating the corresponding radiative corrections and by the apparent discrepancy between the Rosenbluth and polarization transfer measurements of the proton electromagnetic form factors. New, corrected values for the scattering cross sections are presented, as well as a new form factor fit in the Q2 range from 1 to 8 . 83GeV2 . Our reanalysis brings the combined results of the SLAC experiments into better agreement with the polarization transfer data, but a significant discrepancy remains for Q2 > 3GeV2 .
Pion transition form factor through Dyson-Schwinger equations
Raya, Khépani
2016-01-01
In the framework of Dyson-Schwinger equations (DSE), we compute the $\\gamma^*\\gamma\\to\\pi^0$ transition form factor, $G(Q^2)$. For the first time, in a continuum approach to quantun chromodynamics (QCD), it was possible to compute $G(Q^2)$ on the whole domain of space-like momenta. Our result agrees with CELLO, CLEO and Belle collaborations and, with the well-known asymptotic QCD limit, $2f_\\pi$. Our analysis unifies this prediction with that of the pion's valence-quark parton distribution amplitude (PDA) and elastic electromagnetic form factor.
Pion transition form factor through Dyson-Schwinger equations
Raya, Khépani
2016-10-01
In the framework of Dyson-Schwinger equations (DSE), we compute the γ*γ→π0 transition form factor, G(Q2). For the first time, in a continuum approach to quantun chromodynamics (QCD), it was possible to compute G(Q2) on the whole domain of space-like momenta. Our result agrees with CELLO, CLEO and Belle collaborations and, with the well- known asymptotic QCD limit, 2ƒπ. Our analysis unifies this prediction with that of the pion's valence-quark parton distribution amplitude (PDA) and elastic electromagnetic form factor.
Electromagnetic form factors of the Δ with D-waves
Ramalho, Gilberto T.F. [CFTP, Institute Superior Tecnico, Lisbon (Portugal); Pena, Maria Teresa [CFTP, Institute Superior Tecnico, Lisbon (Portugal); Gross, Franz L. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2010-06-01
The electromagnetic form factors of the Δ baryon are evaluated within the framework of a covariant spectator quark model, where S and D-states are included in the Δ wave function. We predict all the four Δ multipole form factors: the electric charge G_{E0}, the magnetic dipole G_{M1}, the electric quadrupole G_{E2} and the magnetic octupole G_{M3}. We compare our predictions with other theoretical calculations. Our results are compatible with the available experimental data and recent lattice QCD data.
Electromagnetic form factors of the Delta with D-waves
Ramalho, G; Gross, Franz
2010-01-01
The electromagnetic form factors of the Delta baryon are evaluated within the framework of a covariant spectator quark model, where S and D-states are included in the $\\Delta$ wave function. We predict all the four Delta multipole form factors: the electric charge GE0, the magnetic dipole GM1, the electric quadrupole GE2 and the magnetic octupole GM3. We compare our predictions with other theoretical calculations. Our results are compatible with the available experimental data and recent lattice QCD data.
Excited state systematics in extracting nucleon electromagnetic form factors
Capitani, Stefano; von Hippel, Georg; Jäger, Benjamin; Knippschild, Bastian; Meyer, Harvey B; Rae, Thomas D; Wittig, Hartmut
2012-01-01
We present updated preliminary results for the nucleon electromagnetic form factors for non-perturbatively $\\mathcal{O}(a)$ improved Wilson fermions in $N_f=2$ QCD measured on the CLS ensembles. The use of the summed operator insertion method allows us to suppress the influence of excited states in our measurements. A study of the effect that excited state contaminations have on the $Q^2$ dependence of the extracted nucleon form factors may then be made through comparisons of the summation method to standard plateau fits, as well as to excited state fits.
Tensor form factors of the octet hyperons in QCD
kucukarslan, A; Ozpineci, A
2016-01-01
Light-cone QCD sum rules to leading order in QCD are used to investigate the tensor form factors of the $\\Sigma-\\Sigma$, $\\Xi-\\Xi$ and $ \\Sigma-\\Lambda$ transitions in the range $1 GeV^2 \\leq Q^2 \\leq 10 GeV^2$. The DAs of $\\Sigma$, $\\Xi$ and $\\Lambda$ baryon have been calculated without higher order terms. Then, study including higher order corrections have been done for $\\Sigma$ and $\\Lambda$ baryon. The result of form factors are obtained using these two DAs. We make a comparison with the predictions of the chiral quark soliton model.
Deuteron form factor measurements at low momentum transfers
Schlimme B. S.
2016-01-01
Full Text Available A precise measurement of the elastic electron-deuteron scattering cross section at four-momentum transfers of 0.24 fm−1 ≤ Q ≤ 2.7 fm−1 has been performed at the Mainz Microtron. In this paper we describe the utilized experimental setup and the necessary analysis procedure to precisely determine the deuteron charge form factor from these data. Finally, the deuteron charge radius rd can be extracted from an extrapolation of that form factor to Q2 = 0.
The $B\\to K^*$ form factors on the lattice
Agadjanov, Andria; Meißner, Ulf-G; Rusetsky, Akaki
2016-01-01
The extraction of the $B\\to K^*$ transition form factors from lattice data is studied, applying non-relativistic effective field theory in a finite volume. The possible mixing of $\\pi K$ and $\\eta K$ states is taken into account. The two-channel analogue of the Lellouch-L\\"uscher formula is reproduced. Due to the resonance nature of the $K^*$, an equation is derived, which allows to determine the form factors at the pole position in a process-independent manner. The infinitely-narrow width approximation of the results is discussed.
Pion Form Factor in the Light-Front
Pacheco-Bicudo-Cabral de Melo, J
2004-01-01
The pion electromagnetic form factor is calculated with a light-front quark model. The "plus" and "minus" component of the electromagnetic current are used to calculate the electromagnetic form factor in the Breit frame with two models for the q\\bar{q} vertex. The light front constituent quark models describes very well hadronic wave function for pseudo-scalar and vector particles. Symmetry problems arinsing in the light-front approach are solved by the pole dislocation method. The results are compared with new experimental data and with other quark models.
Sudakov effects in B -> pi l nu form factors
Descotes, S
2002-01-01
In order to obtain information about the Standard Model from exclusive hadronic two-body B-decays, we have to quantify non-perturbative QCD effects. Approaches based on the factorization of mass singularities into hadronic distribution amplitudes and form factors provide a rigorous theoretical framework for the evaluation of these effects in the heavy quark limit. But it is not possible to calculate power corrections in a model-independent way, because of non-factorizing long-distance contributions. It has been argued that Sudakov effects suppress these contributions and render the corresponding corrections perturbatively calculable. In this paper we examine this claim for the related example of semileptonic B -> pi decays and conclude that it is not justified. The uncertainties in our knowledge of the mesons' distribution amplitudes imply that the calculations of the form factors are not sufficiently precise to be useful phenomenologically. Moreover, a significant contribution comes from the non-perturbative...
Pseudo-scalar form factors at three loops in QCD
Ahmed, Taushif [The Institute of Mathematical Sciences, IV Cross Road,CIT Campus, Chennai 600 113, Tamil Nadu (India); Gehrmann, Thomas [Department of Physics, University of Zürich,Winterthurerstrasse 190, CH-8057 Zürich (Switzerland); Mathews, Prakash [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar,Kolkata 700 064, West Bengal (India); Rana, Narayan; Ravindran, V. [The Institute of Mathematical Sciences, IV Cross Road,CIT Campus, Chennai 600 113, Tamil Nadu (India)
2015-11-24
The coupling of a pseudo-scalar Higgs boson to gluons is mediated through a heavy quark loop. In the limit of large quark mass, it is described by an effective Lagrangian that only admits light degrees of freedom. In this effective theory, we compute the three-loop massless QCD corrections to the form factor that describes the coupling of a pseudo-scalar Higgs boson to gluons. Due to the axial anomaly, the pseudo-scalar operator for the gluonic field strength mixes with the divergence of the axial vector current. Working in dimensional regularization and using the ’t Hooft-Veltman prescription for the axial vector current, we compute the three-loop pseudo-scalar form factors for massless quarks and gluons. Using the universal infrared factorization properties, we independently derive the three-loop operator mixing and finite operator renormalisation from the renormalisation group equation for the form factors, thereby confirming recent results in the operator product expansion. The finite part of the three-loop form factor is an important ingredient to the precise prediction of the pseudo-scalar Higgs boson production cross section at hadron colliders. We discuss potential applications and derive the hard matching coefficient in soft-collinear effective theory.
Above-Threshold Poles in Model-Independent Form Factor Parametrizations
Grinstein, Benjamin
2015-01-01
The model-independent parametrization for exclusive hadronic form factors commonly used for semileptonic decays is generalized to allow for the inclusion of above-threshold resonant poles of known mass and width. We discuss the interpretation of such poles, particularly with respect to the analytic structure of the relevant two-point Green's function in which they reside. Their presence has a remarkably small effect on the parametrization, as we show explicitly for the case of $D \\to \\pi e^+ \
Analytic results for planar three-loop integrals for massive form factors
Henn, Johannes M.; Smirnov, Alexander V.; Smirnov, Vladimir A.
2016-12-01
We use the method of differential equations to analytically evaluate all planar three-loop Feynman integrals relevant for form factor calculations involving massive particles. Our results for ninety master integrals at general q 2 are expressed in terms of multiple polylogarithms, and results for fiftyone master integrals at the threshold q 2 = 4 m 2 are expressed in terms of multiple polylogarithms of argument one, with indices equal to zero or to a sixth root of unity.
Analytic results for planar three-loop integrals for massive form factors
Henn, Johannes M; Smirnov, Vladimir A
2016-01-01
We use the method of differential equations to analytically evaluate all planar three-loop Feynman integrals relevant for form factor calculations involving massive particles. Our results for ninety master integrals at general $q^2$ are expressed in terms of multiple polylogarithms, and results for fiftyone master integrals at the threshold $q^2=4m^2$ are expressed in terms of multiple polylogarithms of argument one, with indices equal to zero or to a sixth root of unity.
Factorization, resummation and sum rules for heavy-to-light form factors
Wang, Yu-Ming
2016-01-01
Precision calculations of heavy-to-light form factors are essential to sharpen our understanding towards the strong interaction dynamics of the heavy-quark system and to shed light on a coherent solution of flavor anomalies. We briefly review factorization properties of heavy-to-light form factors in the framework of QCD factorization in the heavy quark limit and discuss the recent progress on the QCD calculation of $B \\to \\pi$ form factors from the light-cone sum rules with the $B$-meson distribution amplitudes. Demonstration of QCD factorization for the vacuum-to-$B$-meson correlation function used in the sum-rule construction and resummation of large logarithms in the short-distance functions entering the factorization theorem are presented in detail. Phenomenological implications of the newly derived sum rules for $B \\to \\pi$ form factors are further addressed with a particular attention to the extraction of the CKM matrix element $|V_{ub}|$.
Spin-2 Form Factors at Three Loop in QCD
Ahmed, Taushif; Mathews, Prakash; Rana, Narayan; Ravindran, V
2015-01-01
Spin-2 fields are often candidates in physics beyond the Standard Model namely the models with extra-dimensions where spin-2 Kaluza-Klein gravitons couple to the fields of the SM. Also, in the context of Higgs searches, spin-2 fields have been studied as an alternative to the scalar Higgs boson. In this article, we present the complete three loop QCD radiative corrections to the spin-2 quark-antiquark and spin-2 gluon-gluon form factors in SU(N) gauge theory with $n_f$ light flavors. These form factors contribute to both quark-antiquark and gluon-gluon initiated processes involving spin-2 particle in the hadronic reactions at the LHC. We have studied the structure of infrared singularities in these form factors up to three loop level using Sudakov integro-differential equation and found that the anomalous dimensions originating from soft and collinear regions of the loop integrals coincide with those of the electroweak vector boson and Higgs form factors confirming the universality of the infrared singulariti...
Dispersive analysis of the pion transition form factor
Hoferichter, Martin; Leupold, Stefan; Niecknig, Franz; Schneider, Sebastian P
2014-01-01
We analyze the pion transition form factor using dispersion theory. We calculate the singly-virtual form factor in the time-like region based on data for the $e^+e^-\\to 3\\pi$ cross section, generalizing previous studies on $\\omega,\\phi\\to3\\pi$ decays and $\\gamma\\pi\\to\\pi\\pi$ scattering, and verify our result by comparing to $e^+e^-\\to\\pi^0\\gamma$ data. We perform the analytic continuation to the space-like region, predicting the poorly-constrained space-like transition form factor below 1 GeV, and extract the slope of the form factor at vanishing momentum transfer $a_\\pi=(30.7\\pm0.6)\\times 10^{-3}$. We derive the dispersive formalism necessary for the extension of these results to the doubly-virtual case, as required for the pion-pole contribution to hadronic light-by-light scattering in the anomalous magnetic moment of the muon.
Radiative corrections in nucleon time-like form factors measurements
Van de Wiele, Jacques [Universite de Paris-Sud, Institut de Physique Nucleaire, Orsay Cedex (France); Ong, Saro [Universite de Paris-Sud, Institut de Physique Nucleaire, Orsay Cedex (France); Universite de Picardie Jules Verne, Amiens (France)
2013-02-15
The completely general radiative corrections to lowest order, including the final- and initial-state radiations, are studied in proton-antiproton annihilation into an electron-positron pair. Numerical estimates have been made in a realistic configuration of the PANDA detector at FAIR for the proton time-like form factors measurements. (orig.)
The Proton Form Factor Ratio Measurements at Jefferson Lab
Punjabi, Vina
2014-01-01
The ratio of the proton form factors, GEp/GMp, has been measured from Q2 of 0.5 GeV2 to 8.5 GeV2, at the Jefferson Laboratory, using the polarization transfer method. This ratio is extracted directly from the measured ratio of the transverse and longitudinal polarization components of the recoiling proton in elastic electron-proton scattering. The discovery that the proton form factor ratio measured in these experiments decreases approximately linearly with four-momentum transfer, Q2, for values above ? 1 GeV2, is one of the most significant results to come out of JLab. These results have had a large impact on progress in hadronic physics; and have required a significant rethinking of nucleon structure. The increasingly common use of the double-polarization technique to measure the nucleon form factors, in the last 15 years, has resulted in a dramatic improvement of the quality of all four nucleon electromagnetic form factors, GEp, GMp, GEn and GMn. There is an approved experiment at JLab, GEP(V), to continue...
Analytic two-loop form factors in N=4 SYM
Brandhuber, Andreas; Yang, Gang
2012-01-01
We derive a compact expression for the three-point MHV form factors of half-BPS operators in N=4super Yang-Mills at two loops. The main tools of our calculation are generalised unitarity applied at the form factor level, and the compact expressions for supersymmetric tree-level form factors and amplitudes entering the cuts. We confirm that infrared divergences exponentiate as expected, and that collinear factorisation is entirely captured by an ABDK/BDS ansatz. Next, we construct the two-loop remainder function obtained by subtracting this ansatz from the full two-loop form factor and compute it numerically. Using symbology, combined with various physical constraints and symmetries, we find a unique solution for its symbol. With this input we construct a remarkably compact analytic expression for the remainder function, which contains only classical polylogarithms, and compare it to our numerical results. Furthermore, we make the surprising observation that our remainder is equal to the maximally transcendent...
Spin-2 form factors at three loop in QCD
Ahmed, Taushif; Das, Goutam; Mathews, Prakash; Rana, Narayan; Ravindran, V.
2015-12-01
Spin-2 fields are often candidates in physics beyond the Standard Model namely the models with extra-dimensions where spin-2 Kaluza-Klein gravitons couple to the fields of the Standard Model. Also, in the context of Higgs searches, spin-2 fields have been studied as an alternative to the scalar Higgs boson. In this article, we present the complete three loop QCD radiative corrections to the spin-2 quark-antiquark and spin-2 gluon-gluon form factors in SU(N) gauge theory with n f light flavors. These form factors contribute to both quark-antiquark and gluon-gluon initiated processes involving spin-2 particle in the hadronic reactions at the LHC. We have studied the structure of infrared singularities in these form factors up to three loop level using Sudakov integro-differential equation and found that the anomalous dimensions originating from soft and collinear regions of the loop integrals coincide with those of the electroweak vector boson and Higgs form factors confirming the universality of the infrared singularities in QCD amplitudes.
P and T Violating Form Factors of the Deuteron
de Vries, J.; Mereghetti, E.; Timmermans, R. G. E.; van Kolck, U.
2011-01-01
We calculate the electric-dipole and magnetic-quadrupole form factors of the deuteron that arise as a low-energy manifestation of parity and time-reversal violation in quark-gluon interactions. We consider the QCD vacuum angle and the dimension-six operators that originate from physics beyond the st
Measurement of the pion form factor at higher energies
Mack, D.J. [CEBAF, Newport News, VA (United States)
1994-04-01
One of the strongest arguments for increasing the nominal CEBAF beam energy to equal or exceed 6 GeV is that one would be able to make quality high Q{sup 2} measurements of the charged pion form factor.
On Form Factors and Correlation Functions in Twistor Space
Koster, Laura; Staudacher, Matthias; Wilhelm, Matthias
2016-01-01
In this paper, we continue our study of form factors and correlation functions of gauge-invariant local composite operators in the twistor-space formulation of N=4 super Yang-Mills theory. Using the vertices for these operators obtained in our recent papers arXiv:1603.04471 and arXiv:1604.00012, we show how to calculate the twistor-space diagrams for general N^kMHV form factors via the inverse soft limit, in analogy to the amplitude case. For general operators without $\\dot\\alpha$ indices, we then reexpress the NMHV form factors from the position-twistor calculation in terms of momentum twistors, deriving and expanding on a relation between the two twistor formalisms previously observed in the case of amplitudes. Furthermore, we discuss the calculation of generalized form factors and correlation functions as well as the extension to loop level, in particular providing an argument promised in arXiv:1410.6310.
Ward Identities, B-> \\rho Form Factors and |V_ub|
Gilani, A H S; Riazuddin, M; Gilani, Amjad Hussain Shah
2003-01-01
The exclusive FCNC beauty semileptonic decay B-> \\rho is studied using Ward identities in a general vector meson dominance framework, predicting vector meson couplings involved. The long distance contributions are discussed which results to obtain form factors and |V_ub|. A detailed comparison is given with other approaches.
Determination of Transverse Charge Density from Kaon Form Factor Data
Mejia-Ott, Johann; Horn, Tanja; Pegg, Ian; Mecholski, Nicholas; Carmignotto, Marco; Ali, Salina
2016-09-01
At the level of nucleons making up atomic nuclei, among subatomic particles made up of quarks, K-mesons or kaons represent the most simple hadronic system including the heavier strange quark, having a relatively elementary bound state of a quark and an anti-quark as its valence structure. Its electromagnetic structure is then parametrized by a single, dimensionless quantity known as the form factor, the two-dimensional Fourier transform of which yields the quantity of transverse charge density. Transverse charge density, in turn, provides a needed framework for the interpretation of form factors in terms of physical charge and magnetization, both with respect to the propagation of a fast-moving nucleon. To this is added the value of strange quarks in ultimately presenting a universal, process-independent description of nucleons, further augmenting the importance of studying the kaon's internal structure. The pressing character of such research questions directs the present paper, describing the first extraction of transverse charge density from electromagnetic kaon form factor data. The extraction is notably extended to form factor data at recently acquired higher energy levels, whose evaluation could permit more complete phenomenological models for kaon behavior to be proposed. This work was supported in part by NSF Grant PHY-1306227.
Nucleon form factors program with SBS at JLAB
Wojtsekhowski, Bogdan B. [JLAB
2014-12-01
The physics of the nucleon form factors is the basic part of the Jefferson Laboratory program. We review the achievements of the 6-GeV era and the program with the 12- GeV beam with the SBS spectrometer in Hall A, with a focus on the nucleon ground state properties.
Proton and kaon timelike form factors from BABAR
Serednyakov, S I
2015-01-01
The latest BABAR results on the proton and kaon timelike form factors (FF) are presented. The special emphasize is made on comparison of the spacelike and timelike FFs and the rise of the proton FF near threshold. The behavior of the cross section of e+e- annihilation into hadrons near the nucleon-antinucleon threshold is discussed.
Nucleon form factors with dynamical twisted mass fermions
Alexandrou, C; Brinet, M; Carbonell, J; Drach, V; Harraud, P A; Korzec, T; Koutsou, G
2008-01-01
The electromagnetic and axial form factors of the nucleon are evaluated in twisted mass QCD with two degenerate flavors of light, dynamical quarks. The axial charge g_A, magnetic moment and the Dirac and Pauli radii are determined for pion masses in the range 300 MeV to 500 MeV.
Further comment on pion electroproduction and the axial form factor
Bernard, V; Meißner, Ulf G; Mei{\\ss}ner, Ulf-G.
2001-01-01
We show that a recent claim (H.Haberzettl, Phys. Rev. Lett. 85 (2000) 3576) that one cannot extract the nucleon weak axial form factor G_A (t) from charged pion threshold electroproduction is incorrect. Thus previous calculations remain valid and threshold charged pion electroproduction experiments can indeed be used to determine G_A (t), and they should certainly be pursued.
Spin-2 form factors at three loop in QCD
Ahmed, Taushif [The Institute of Mathematical Sciences,IV Cross Road, CIT Campus, Chennai 600 113 (India); Das, Goutam; Mathews, Prakash [Saha Institute of Nuclear Physics,1/AF Bidhan Nagar, Kolkata 700 064 (India); Rana, Narayan; Ravindran, V. [The Institute of Mathematical Sciences,IV Cross Road, CIT Campus, Chennai 600 113 (India)
2015-12-15
Spin-2 fields are often candidates in physics beyond the Standard Model namely the models with extra-dimensions where spin-2 Kaluza-Klein gravitons couple to the fields of the Standard Model. Also, in the context of Higgs searches, spin-2 fields have been studied as an alternative to the scalar Higgs boson. In this article, we present the complete three loop QCD radiative corrections to the spin-2 quark-antiquark and spin-2 gluon-gluon form factors in SU(N) gauge theory with n{sub f} light flavors. These form factors contribute to both quark-antiquark and gluon-gluon initiated processes involving spin-2 particle in the hadronic reactions at the LHC. We have studied the structure of infrared singularities in these form factors up to three loop level using Sudakov integro-differential equation and found that the anomalous dimensions originating from soft and collinear regions of the loop integrals coincide with those of the electroweak vector boson and Higgs form factors confirming the universality of the infrared singularities in QCD amplitudes.
Electromagnetic form factors of heavy flavored vector mesons
Priyadarsini, M.; Dash, P. C.; Kar, Susmita; Patra, Sweta P.; Barik, N.
2016-12-01
We study the electromagnetic form factors of heavy flavored vector mesons such as (D*,Ds*,J /Ψ ) , (B*,Bs*,ϒ ) via one photon radiative decays (V →P γ ) in the relativistic independent quark (RIQ) model based on a flavor independent average interaction potential in the scalar vector harmonic form. The momentum dependent spacelike (q2<0 ) form factors calculated in this model are analytically continued to the physical timelike region 0 ≤q2≤(MV-MP)2 . The predicted coupling constant gV P γ=FV P(q2=0 ) for real photon case in the limit q2→0 and decay widths Γ (V →P γ ) are found in reasonable agreement with experimental data and other model predictions.
Nucleon form factors, generalized parton distributions and quark angular momentum
Diehl, Markus [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kroll, Peter [Bergische Univ., Wuppertal (Germany). Fachbereich Physik; Regensburg Univ. (Germany). Institut fuer Theoretische Physik
2013-02-15
We extract the individual contributions from u and d quarks to the Dirac and Pauli form factors of the proton, after a critical examination of the available measurements of electromagnetic nucleon form factors. From this data we determine generalized parton distributions for valence quarks, assuming a particular form for their functional dependence. The result allows us to study various aspects of nucleon structure in the valence region. In particular, we evaluate Ji's sum rule and estimate the total angular momentum carried by valence quarks at the scale {mu}=2 GeV to be J{sup u}{sub v}=0.230{sup +0.009}{sub -0.024} and J{sup d}{sub v}=-0.004{sup +0.010}{sub -0.016}.
张春华
2014-01-01
Objective To explore aspirin resistance(AR)and its relevant influencing factors in patients on maintenance hemodialysis(MHD).Methods Patients on MHD who visited Beijing Chaoyang Hospital from June 1 to 30,2011 were enrolled in this study.A total of 150 age and gender matched individuals with normal renal function were taken as control group.Anthropometric data,bio-
A review of potential factors relevant to coping in patients with advanced cancer
Thomsen, Thora Grothe; Hansen, Susan Rydahl; Wagner, Lis
2010-01-01
The aim was to identify characteristics that are considered to describe coping in patients with advanced cancer, as seen from a patient perspective. Based on the identified characteristics, the second aim was to identify potential factors that are relevant to coping in patients with advanced cancer....
Gomez-Rocha, Maria
2014-01-01
The point-form version of the Bakamjian-Thomas construction is applied to the description of several semileptonic decays of mesons. Weak form factors are extracted without ambiguity for pseudoscalar-to-pseudoscalar as well as for pseudoscalar-to-vector transitions of mesons from the most general covariant decomposition of the weak current. No manifestation of cluster-separability violation appears in the form of non-physical contributions to the structure of such a current, in contrast to what happens in the electromagnetic case. Moreover, no frame dependence is observed when we extract the form factors from the most general covariant decomposition of the current, which contrasts with analogous front-form calculations that involve vector mesons in the transition. We present our results for heavy-light meson decays, i.e. $B\\to D$, as well as for $B$ and $D$ mesons decaying into $\\pi$, $\\rho$ and $K^{(*)}$ and perform a numerical comparison with the analogous front-form approach. Differences between point and f...
Form factors of the finite quantum XY-chain
Iorgov, Nikolai, E-mail: iorgov@bitp.kiev.ua [Bogolyubov Institute for Theoretical Physics, Kiev 03680 (Ukraine)
2011-08-19
Explicit factorized formulas for the matrix elements (form factors) of the spin operators {sigma}{sup x} and {sigma}{sup y} between the eigenvectors of the Hamiltonian of the finite quantum periodic XY-chain in a transverse field were derived. The derivation is based on the relations between three models: the model of quantum XY-chain, Ising model on 2D lattice and N = 2 Baxter-Bazhanov-Stroganov {tau}{sup (2)}-model. Due to these relations we transfer the formulas for the form factors of the latter model recently obtained by the use of separation of variables method to the model of quantum XY-chain. Hopefully, the formulas for the form factors will help in analysis of multipoint dynamic correlation functions at a finite temperature. As an example, we re-derive the asymptotics of the two-point correlation function in the disordered phase without the use of the Toeplitz determinants and the Wiener-Hopf factorization method.
Factors Affecting the Form of Substitute Family Care
Monika Chrenková
2015-11-01
Full Text Available Recently, the system of care for endangered children has changed from the institutional as well as legislative point of view. In one of the partial areas of ongoing changes, research activities realised within the Students’ Grant Competition called The Factors Affecting the Form of Substitute Family Care are being focused. We deal with this topic because various forms of substitute family care are distinguished in the Czech Republic, where children are placed for various reasons, but we do not know the correct context of such placements. The main aim of the realised research was to find out the frequency of choosing a given form of placing children in substitute family care according to followed variables. The research sample of the quantitative research was consisted of children placed in one of the forms of substitute family care in the Moravian-Silesian region.
Master integrals for the four-loop Sudakov form factor
Boels, Rutger; Yang, Gang
2016-01-01
The light-like cusp anomalous dimension is a universal function in the analysis of infrared divergences. In maximally ($\\mathcal{N}=4$) supersymmetric Yang-Mills theory (SYM) in the planar limit, it is known, in principle, to all loop orders. The non-planar corrections are not known in any theory, with the first appearing at the four-loop order. Probably the simplest quantity which contains this correction is the four-loop two-point form factor of the stress tensor multiplet. This form factor was obtained in integrand form in a previous work for $\\mathcal{N}=4$ SYM, up to a single parameter. In this work, a reduction of the appearing integrals obtained by solving integration-by-parts (IBP) identities using (a tweaked version of) Reduze is reported. The form factor is shown to be independent of the remaining parameter at integrand level due to an intricate pattern of cancellations after IBP reduction. The appearing master integrals are cross-checked using algebraic techniques explored in the Mint package. The ...
Pseudo-scalar Form Factors at Three Loops in QCD
Ahmed, Taushif; Mathews, Prakash; Rana, Narayan; Ravindran, V
2015-01-01
The coupling of a pseudo-scalar Higgs boson to gluons is mediated through a heavy quark loop. In the limit of large quark mass, it is described by an effective Lagrangian that only admits light degrees of freedom. In this effective theory, we compute the three-loop massless QCD corrections to the form factor that describes the coupling of a pseudo-scalar Higgs boson to gluons. Due to the axial anomaly, the pseudo-scalar operator for the gluonic field strength mixes with the divergence of the axial vector current. Working in dimensional regularization and using the 't~Hooft-Veltman prescription for the axial vector current, we compute the three-loop pseudo-scalar form factors for massless quarks and gluons. Using the universal infrared factorization properties, we independently derive the three-loop operator mixing and finite operator renormalisation from the renormalisation group equation for the form factors, thereby confirming recent results in the operator product expansion. The finite part of the three-lo...
Pion Electromagnetic Form Factor in Virtuality Distribution Formalism
Radyushkin, A V
2015-01-01
We discuss two applications of the {\\it Virtuality Distribution Amplitudes} (VDA) formalism developed in our recent papers. We start with an overview of the main properties of the pion distribution amplitude emphasizing the quantitative measures of its width, and possibility to access them through the pion transition form factor studies. We formulate the basic concepts of the VDA approach and introduce the pion transverse momentum distribution amplitude (TMDA) which plays, in a covariant Lagrangian formulation, a role similar to that of the pion wave function in the 3-dimensional Hamiltonian light-front approach. We propose simple factorized models for soft TMDAs, and use them to describe existing data on the pion transition form factor, thus fixing the scale determining the size of the transverse-momentum effects. Finally, we apply the VDA approach to the one-gluon exchange contribution for the pion electromagnetic form factor. We observe a very late $Q^2 \\gtrsim 20$ GeV$^2$ onset of transition to the asympt...
Form factors for B --> $\\pi$l$\\overline{\
Burford, D R; Flynn, J M; Gough, B J; Hazel, N M; Nieves, J; Shanahan, H P; Burford, D R; Duong, H D; Flynn, J M; Gough, B J; Hazel, N M; Nieves, J; Shanahan, H P
1995-01-01
We present a unified method for analysing form factors in B -> pi l nu-bar_l and B -> K* gamma decays. The analysis provides consistency checks on the q^2 and 1/M extrapolations necessary to obtain the physical decay rates. For the first time the q^2 dependence of the form factors is obtained at the B scale. In the B -> pi l nu-bar_l case, we show that pole fits to f^+ may not be consistent with the q^2 behaviour of f^0, leading to a possible factor of two uncertainty in the decay rate and hence in the value of |V_{ub}|^2 deduced from it. For B -> K* gamma, from the combined analysis of form factors T_1 and T_2, we find the hadronisation ratio R_{K^*} of the exclusive B -> K* gamma to the inclusive b -> s gamma rates is of order 35% or 15% for constant and pole-type behaviour of T_2 respectively.
Nucleon form factors on the lattice with light dynamical fermions
Goeckeler, M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Haegler, P. [Technische Univ. Muenchen, Garching (Germany). Inst. fuer Theoretische Physik T39; Horsley, R. [Edinburgh Univ. (GB). School of Physics] (and others)
2007-09-15
The electromagnetic form factors provide important insight into the internal structure of the nucleon and continue to be of major interest for experiment and phenomenology. For an intermediate range of momenta the form factors can be calculated on the lattice. However, the reliability of the results is limited by systematic errors mostly due to the required extrapolation to physical quark masses. Chiral effective field theories predict a rather strong quark mass dependence in a range which was yet inaccessible for lattice simulations. We give an update on recent results from the QCDSF collaboration using gauge configurations with dynamical N{sub f}=2, non-perturbatively O(a)-improved Wilson fermions at pion masses as low as 350 MeV. (orig.)
η' transition form factor from space- and timelike experimental data
Escribano, R.; Gonzàlez-Solís, S.; Masjuan, P.; Sanchez-Puertas, P.
2016-09-01
The η' transition form factor is reanalyzed in view of the recent first observation by BESIII of the Dalitz decay η'→γ e+e- in both space- and timelike regions at low and intermediate energies using the Padé approximants method. The present analysis provides a suitable parametrization for reproducing the measured form factor in the whole energy region and allows one to extract the corresponding low-energy parameters together with a prediction of their values at the origin, related to Γη'→γ γ , and the asymptotic limit. The η - η' mixing is reassessed within a mixing scheme compatible with the large-Nc chiral perturbation theory at next-to-leading order, with particular attention to the Okubo-Zweig-Iizuka-rule-violating parameters. The J /ψ , Z →η(')γ decays are also considered and predictions are reported.
On Form Factors in N=4 SYM Theory and Polytopes
Bork, L V
2014-01-01
In this paper we discuss different recursion relations (BCFW and all-line shift) for the form factors of the operators from the $\\mathcal{N}=4$ SYM stress-tensor current supermultiplet $T^{AB}$ in momentum twistor space. We show that cancelations of spurious poles and equivalence between different types of recursion relations can be naturally understood using geometrical interpretation of the form factors as special limit of the volumes of polytopes in $\\mathbb{C}\\mathbb{P}^4$ in close analogy with the amplitude case. We also show how different relations for the IR pole coefficients can be easily derived using momentum twistor representation. This opens an intriguing question - which of powerful on-shell methods and ideas can survive off-shell ?
Measurement of the gamma gamma* -> pi0 transition form factor
Aubert, B.
2009-06-02
We study the reaction e{sup +}e{sup -} {yields} e{sup +}e{sup -}{pi}{sup 0} in the single tag mode and measure the differential cross section d{sigma}/dQ{sup 2} and the {gamma}{gamma}* {yields} {pi}{sup 0} transition form factor in the mometum transfer range from 4 to 40 GeV{sup 2}. At Q{sup 2} > 10 GeV{sup 2} the measured form factor exceeds the asymptotic limit predicted by perturbative QCD. The analysis is based on 442 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.
Octet baryon electromagnetic form factors in a relativistic quark model
Ramalho, G
2011-01-01
We study the octet baryon electromagnetic properties by applying the covariant spectator quark model, and provide covariant parametrization that can be used to study baryon electromagnetic reactions. While we use the lattice QCD data in the large pion mass regime (small pion cloud effects) to determine the parameters of the model in the valence quark sector, we use the nucleon physical and octet baryon magnetic moment data to parameterize the pion cloud contributions. The valence quark contributions for the octet baryon electromagnetic form factors are estimated by extrapolating the lattice parametrization in the large pion mass regime to the physical regime. As for the pion cloud contributions, we parameterize them in a covariant, phenomenological manner, combined with SU(3) symmetry. We also discuss the impact of the pion cloud effects on the octet baryon electromagnetic form factors and their radii.
Flavor Analysis of Nucleon, Δ , and Hyperon Electromagnetic Form Factors
Rohrmoser, Martin; Choi, Ki-Seok; Plessas, Willibald
2017-03-01
By the analysis of the world data base of elastic electron scattering on the proton and the neutron (for the latter, in fact, on ^2H and ^3He) important experimental insights have recently been gained into the flavor compositions of nucleon electromagnetic form factors. We report on testing the Graz Goldstone-boson-exchange relativistic constituent-quark model in comparison to the flavor contents in low-energy nucleons, as revealed from electron-scattering phenomenology. It is found that a satisfactory agreement is achieved between theory and experiment for momentum transfers up to Q^2˜ 4 GeV^2, relying on three-quark configurations only. Analogous studies have been extended to the Δ and the hyperon electromagnetic form factors. For them we here show only some sample results in comparison to data from lattice quantum chromodynamics.
Octet Baryon Electromagnetic Form Factors in a Relativistic Quark Model
Gilberto Ramalho, Kazuo Tsushima
2011-09-01
We study the octet baryon electromagnetic properties by applying the covariant spectator quark model, and provide covariant parametrization that can be used to study baryon electromagnetic reactions. While we use the lattice QCD data in the large pion mass regime (small pion cloud effects) to determine the parameters of the model in the valence quark sector, we use the nucleon physical and octet baryon magnetic moment data to parameterize the pion cloud contributions. The valence quark contributions for the octet baryon electromagnetic form factors are estimated by extrapolating the lattice parametrization in the large pion mass regime to the physical regime. As for the pion cloud contributions, we parameterize them in a covariant, phenomenological manner, combined with SU(3) symmetry. We also discuss the impact of the pion cloud effects on the octet baryon electromagnetic form factors and their radii.
A reanalysis of Rosenbluth measurements of the proton form factors
Gramolin, A V
2016-01-01
We present a reanalysis of the data from SLAC experiments E140 [R. C. Walker et al., Phys. Rev. D 49, 5671 (1994)] and NE11 [L. Andivahis et al., Phys. Rev. D 50, 5491 (1994)] on elastic electron-proton scattering. This work is motivated by recent progress in calculating the corresponding radiative corrections and by the apparent discrepancy between the Rosenbluth and polarization transfer measurements of the proton electromagnetic form factors. New, corrected values for the scattering cross sections are presented, as well as a new form factor fit in the $Q^2$ range from 1 to 8.83 $\\text{GeV}^2$. We also provide a complete set of revised formulas to account for radiative corrections in single-arm measurements of unpolarized elastic electron-proton scattering.
Reanalysis of Rosenbluth measurements of the proton form factors
Gramolin, A. V.; Nikolenko, D. M.
2016-05-01
We present a reanalysis of the data from Stanford Linear Accelerator Center (SLAC) experiments E140 [R. C. Walker et al., Phys. Rev. D 49, 5671 (1994), 10.1103/PhysRevD.49.5671] and NE11 [L. Andivahis et al., Phys. Rev. D 50, 5491 (1994), 10.1103/PhysRevD.50.5491] on elastic electron-proton scattering. This work is motivated by recent progress in calculating the corresponding radiative corrections and by the apparent discrepancy between the Rosenbluth and polarization transfer measurements of the proton electromagnetic form factors. New, corrected values for the scattering cross sections are presented, as well as a new form factor fit in the Q2 range from 1 to 8.83 GeV2. We also provide a complete set of revised formulas to account for radiative corrections in single-arm measurements of unpolarized elastic electron-proton scattering.
Nucleon electromagnetic form factors in two-flavour QCD
Capitani, S; Djukanovic, D; von Hippel, G; Hua, J; Knippschild, B Jäger B; Meyer, H B; Rae, T D; Wittig, H
2015-01-01
We present results for the nucleon electromagnetic form factors, including the momentum transfer dependence and derived quantities (charge radii and magnetic moment). The analysis is performed using O(a) improved Wilson fermions in Nf=2 QCD measured on the CLS ensembles. Particular focus is placed on a systematic evaluation of the influence of excited states in three-point correlation functions, which lead to a biased evaluation, if not accounted for correctly. We argue that the use of summed operator insertions and fit ans\\"atze including excited states allow us to suppress and control this effect. We employ a novel method to perform joint chiral and continuum extrapolations, by fitting the form factors directly to the expressions of covariant baryonic chiral effective field theory. The final results for the charge radii and magnetic moment from our lattice calculations include, for the first time, a full error budget. We find that our estimates are compatible with experimental results within their overall u...
Triton Electric Form Factor at Low-Energies
Sadeghi, H
2009-01-01
Making use of the Effective Field Theory(EFT) expansion recently developed by the authors, we compute the charge form factor of triton up to next-to-next-to-leading order (N$^2$LO). The three-nucleon forces(3NF) is required for renormalization of the three-nucleon system and it effects are predicted for process and is qualitatively supported by available experimental data. We also show that, by including higher order corrections, the calculated charge form factor and charge radius of $^3$H are in satisfactory agreement with the experimental data and the realistic Argonne $v_{18}$ two-nucleon and Urbana IX potential models calculations. This method makes possible a high precision few-body calculations in nuclear physics. Our result converges order by order in low energy expansion and also cut-off independent.
Form factors for semi-leptonic B decays
Zhou, Ran; Bailey, Jon A; Du, Daping; El-Khadra, Aida X; Jain, R D; Kronfeld, Andreas S; Van de Water, Ruth S; Liu, Yuzhi; Meurice, Yannick
2012-01-01
We report on form factors for the B->K l^+ l^- semi-leptonic decay process. We use several lattice spacings from a=0.12 fm down to 0.06 fm and a variety of dynamical quark masses with 2+1 flavors of asqtad quarks provided by the MILC Collaboration. These ensembles allow good control of the chiral and continuum extrapolations. The b-quark is treated as a clover quark with the Fermilab interpretation. We update our results for f_\\parallel and f_\\perp, or, equivalently, f_+ and f_0. In addition, we present new results for the tensor form factor f_T. Model independent results are obtained based upon the z-expansion.
Two-photon transition form factor of c ¯ quarkonia
Chen, Jing; Ding, Minghui; Chang, Lei; Liu, Yu-xin
2017-01-01
The two-photon transition of c ¯c quarkonia are studied within a covariant approach based on the consistent truncation scheme of the quantum chromodynamics Dyson-Schwinger equation for the quark propagator and the Bethe-Salpeter equation for the mesons. We find the decay widths of ηc→γ γ and χc 0 ,2→γ γ in good agreement with experimental data. The obtained transition form factor of ηc→γ γ* for a wide range of spacelike photon-momentum-transfer squared is also in agreement with the experimental findings of the BABAR experiment. As a by-product, the decay widths of ηb,χb 0 ,2→γ γ and the transition form factor of ηb,χc 0 ,b 0→γ γ* are predicted, which await experimental testing.
Dirac and Pauli form factors from lattice QCD
Collins, S.; Goeckeler, M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Haegler, P. [Mainz Univ. (Germany). Inst. fuer Kernphysik; Regensburg Univ. (DE). Inst. fuer Theoretische Physik] (and others)
2011-06-15
We present a comprehensive analysis of the electromagnetic form factors of the nucleon from a lattice simulation with two flavors of dynamical O(a)-improved Wilson fermions. A key feature of our calculation is that we make use of an extensive ensemble of lattice gauge field configurations with four different lattice spacings, multiple volumes, and pion masses down to m{sub {pi}}{proportional_to}180 MeV. We find that by employing Kelly-inspired parametrizations for the Q{sup 2}-dependence of the form factors, we are able to obtain stable fits over our complete ensemble. Dirac and Pauli radii and the anomalous magnetic moments of the nucleon are extracted and results at light quark masses provide evidence for chiral non-analytic behavior in these fundamental observables. (orig.)
Massive three-loop form factor in the planar limit
Henn, Johannes; Smirnov, Vladimir A; Steinhauser, Matthias
2016-01-01
We compute the three-loop QCD corrections to the massive quark-anti-quark-photon form factors $F_1$ and $F_2$ in the large-$N_c$ limit. The analytic results are expressed in terms of Goncharov polylogarithms. This allows for a straightforward numerical evaluation. We also derive series expansions, including power suppressed terms, for three kinematic regions corresponding to small and large invariant masses of the photon momentum, and small velocities of the heavy quarks.
FACTORS AFFECTING FORMING PRECISION IN PATTERNLESS CASTING MANUFACTURING
无
2003-01-01
The patternless casting manufacturing(PCM) technique adopts a new method of double scanning which combines the principle of discreteness and deposition with the resin-bonded sand technique.Two main factors, the liquid penetration regularities in the space between particles and the shape and dimension of the agglomeration unit body, are studied qualitatively and quantitatively.This provides the theoretical basis for selecting the forming technical parameters.The experiments verify the analysis.
Calculation of the π Meson Electromagnetic Form Factor
王志刚; 汪克林; 完绍龙
2001-01-01
The modified flat-bottom potential (MFBP) is given by the combination of the flat-bottom potential with considerations for the infrared and ultraviolet asymptotic behaviour of the effective quark-gluon coupling. The πmeson electromagnetic form factor is calculated in the framework of the coupled Schwinger-Dyson equation andthe Bethe-Salpeter equation in the simplified impulse approximation (dressed vertex) with the MFBP. All ournumerical results give a good fit to experimental values.
Low Energy Constants from Kl4 Form-Factors
Amorós, G; Talavera, P
2000-01-01
We have calculated the form-factors F and G in K ---> pi pi e nu decays (Kl4) to two-loop order in Chiral Perturbation Theory (ChPT). Combining this together with earlier two-loop calculations an updated set of values for the L's, the ChPT constants at p^4, is obtained. We discuss the uncertainties in the determination and the changes compared to previous estimates.
Axial form factor of the nucleon at large momentum transfers
Anikin, I V; Offen, N
2016-01-01
Motivated by the emerging possibilities to study threshold pion electroproduction at large momentum transfers at Jefferson Laboratory following the 12 GeV upgrade, we provide a short theory summary and an estimate of the nucleon axial form factor for large virtualities in the $Q^2 = 1-10~\\text{GeV}^2$ range using next-to-leading order light-cone sum rules.
Modern Youth Sub-Cultures: Characteristic Features, Forming Factors
D A Koltunov
2011-09-01
Full Text Available The growing complexity of today's world, faster social and technological innovations and the resulting impossibility to explain the universe in terms of the classical, traditional systems lead to the emergence of new social and cultural patterns, behavioral standards and particular thinking which make up new sub-cultural paradigms. In this article the author attempts to identify the basic factors forming youth sub-cultures and define their peculiar features in contemporary Russian society.
Flavour decomposition of electromagnetic transition form factors of nucleon resonances
Segovia, Jorge
2016-01-01
In Poincar\\'e-covariant continuum treatments of the three valence-quark bound-state problem, the force behind dynamical chiral symmetry breaking also generates nonpointlike, interacting diquark correlations in the nucleon and its resonances. We detail the impact of these correlations on the nucleon's elastic and nucleon-to-Roper transition electromagnetic form factors, providing flavour-separation versions that can be tested at modern facilities.
Strong CP violation and the neutron electric dipole form factor
Kuckei, J; Faessler, A; Gutsche, T; Kovalenko, S; Lyubovitskij, V E; Pumsa-ard, K; Dib, Claudio; Faessler, Amand; Gutsche, Th.; Kovalenko, Sergey
2005-01-01
We calculate the neutron electric dipole form factor induced by the CP violating theta-term of QCD, within a perturbative chiral quark model which includes pion and kaon clouds. On this basis we derive the neutron electric dipole moment and the electron-neutron Schiff moment. From the existing experimental upper limits on the neutron electric dipole moment we extract constraints on the theta-parameter and compare our results with other approaches.
Pion transverse charge density from timelike form factor data
Gerald Miller, Mark Strikman, Christian Weiss
2011-01-01
The transverse charge density in the pion can be represented as a dispersion integral of the imaginary part of the pion form factor in the timelike region. This formulation incorporates information from e+e- annihilation experiments and allows one to reconstruct the transverse density much more accurately than from the spacelike pion form factor data alone. We calculate the transverse density using an empirical parametrization of the timelike pion form factor and estimate that it is determined to an accuracy of ~10% at a distance b ~ 0.1 fm, and significantly better at larger distances. The density is found to be close to that obtained from a zero-width rho meson pole over a wide range and shows a pronounced rise at small distances. The resulting two-dimensional image of the fast-moving pion can be interpreted in terms of its partonic structure in QCD. We argue that the singular behavior of the charge density at the center requires a substantial presence of pointlike configurations in the pion's partonic wave function, which can be probed in other high-momentum transfer processes.
Finite volume form factors and correlation functions at finite temperature
Pozsgay, Balázs
2009-01-01
In this thesis we investigate finite size effects in 1+1 dimensional integrable QFT. In particular we consider matrix elements of local operators (finite volume form factors) and vacuum expectation values and correlation functions at finite temperature. In the first part of the thesis we give a complete description of the finite volume form factors in terms of the infinite volume form factors (solutions of the bootstrap program) and the S-matrix of the theory. The calculations are correct to all orders in the inverse of the volume, only exponentially decaying (residual) finite size effects are neglected. We also consider matrix elements with disconnected pieces and determine the general rule for evaluating such contributions in a finite volume. The analytic results are tested against numerical data obtained by the truncated conformal space approach in the Lee-Yang model and the Ising model in a magnetic field. In a separate section we also evaluate the leading exponential correction (the $\\mu$-term) associate...
Convergent and discriminant validity of the Five Factor Form.
Rojas, Stephanie L; Widiger, Thomas A
2014-04-01
The current study tests the convergent and discriminant validity of a modified version of the Five Factor Model Rating Form (FFMRF), a one-page, brief measure of the five-factor model. The Five Factor Form (FFF) explicitly identifies maladaptive variants for both poles of each of the 30 facets of the FFMRF. The purpose of the current study was to test empirically whether this modified version still provides a valid assessment of the FFM, as well as to compare its validity as a measure of the FFM to other brief FFM measures. Two independent samples of 510 and 330 community adults were sampled, one third of whom had a history of some form of mental health treatment. The FFF was compared with three abbreviated and/or brief measures of the FFM (i.e., the FFMRF, the Ten Item Personality Inventory, and the Big Five Inventory), a more extended measure (i.e., International Personality Item Pool-NEO), an alternative measure of general personality (i.e., the HEXACO-Personality Inventory-Revised), and a measure of maladaptive personality functioning (i.e., the Personality Inventory for Diagnostic and Statistical Manual of Mental Disorders, 5th edition). The results of the current study demonstrated convergent and discriminant validity, even at the single-item facet level. © The Author(s) 2013.
Measurement of $K_{e3}^{0}$ form factors
Lai, A; Bevan, A; Dosanjh, R S; Gershon, T J; Hay, B; Kalmus, George Ernest; Lazzeroni, C; Munday, D J; Olaiya, E; Parker, M A; White, T O; Wotton, S A; Barr, G; Bocquet, G; Ceccucci, A; Çuhadar-Dönszelmann, T; Cundy, Donald C; D'Agostini, G; Doble, Niels T; Falaleev, V; Gatignon, L; Gonidec, A; Gorini, B; Govi, G; Grafström, P; Kubischta, Werner; Lacourt, A; Norton, A; Palestini, S; Panzer-Steindel, B; Taureg, H; Velasco, M; Wahl, H; Cheshkov, C; Khristov, P Z; Kekelidze, Vladimir D; Litov, L; Madigozhin, D T; Molokanova, N A; Potrebenikov, Yu K; Stoynev, S; Zinchenko, A I; Knowles, I; Martin, V; Sacco, R; Walker, A; Contalbrigo, M; Dalpiaz, Pietro; Duclos, J; Frabetti, P L; Gianoli, A; Martini, M; Petrucci, F; Savrié, M; Bizzeti, A; Calvetti, M; Collazuol, G; Graziani, G; Iacopini, E; Lenti, M; Martelli, F; Veltri, M; Becker, H G; Eppard, K; Eppard, M; Fox, H; Kalter, A; Kleinknecht, K; Koch, U; Köpke, L; Lopes da Silva, P; Marouelli, P; Pellmann, I A; Peters, A; Renk, B; Schmidt, S A; Schönharting, V; Schué, Yu; Wanke, R; Winhart, A; Wittgen, M; Chollet, J C; Fayard, L; Iconomidou-Fayard, L; Ocariz, J; Unal, G; Wingerter-Seez, I; Anzivino, Giuseppina; Cenci, P; Imbergamo, E; Lubrano, P; Mestvirishvili, A; Nappi, A; Pepé, M; Piccini, M; Bertanza, L; Carosi, R; Casali, R; Cerri, C; Cirilli, M; Costantini, F; Fantechi, R; Giudici, Sergio; Mannelli, I; Pierazzini, G M; Sozzi, M; Chèze, J B; Cogan, J; De Beer, M; Debu, P; Formica, A; Granier de Cassagnac, R; Mazzucato, E; Peyaud, B; Turlay, René; Vallage, B; Holder, M; Maier, A; Ziolkowski, M; Arcidiacono, R; Biino, C; Cartiglia, N; Marchetto, F; Menichetti, E; Pastrone, N; Nassalski, J P; Rondio, Ewa; Szleper, M; Wislicki, W; Wronka, S; Dibon, Heinz; Fischer, G; Jeitler, Manfred; Markytan, Manfred; Mikulec, I; Neuhofer, G; Pernicka, M; Taurok, A; Widhalm, L
2004-01-01
The semileptonic decay of the neutral K meson KL -> pi+-e-+v (Ke3), was used to study the strangeness-changing weak interaction of hadrons. A sample of 5.6 million reconstructed events recorded by the NA48 experiment was used to measure the Dalitz plot density. Admitting all possible Lorentz-covariant couplings, the form factors for vector (f+(q^2)), scalar (fs) and tensor (fT) interactions were measured. The linear slope of the vector form factor lambda+=0.0284+-0.0007+-0.0013 and values for the ratios fs/f+(0)=0.015+0.007-0.010 +-0.012 and fT/f+(0)=0.05+0.03-0.04 +-0.03 were obtained. The values for fS and for fT are consistent with zero. Assuming only Vector-Axial vector couplings, lambda+ = 0.02888 +- 0.0004 +- 0.0011 and a good fit consistent with pure V-A couplings were obtained. Alternatively a fit to a dipole form factor yields a pole mass of M = 859 +- 18 MeV, consistent with the K*(892) mass.
Helicity non-conserving form factor of the proton
Voutier, E.; Furget, C.; Knox, S. [Universite Joseph Fourier, Grenoble (France)] [and others
1994-04-01
The study of the hadron structure in the high Q{sup 2} range contributes to the understanding of the mechanisms responsible for the confinement of quarks and gluons. Among the numerous experimental candidates sensitive to these mechanisms, the helicity non-conserving form factor of the proton is a privileged observable since it is controlled by non-perturbative effects. The authors investigate here the feasibility of high Q{sup 2} measurements of this form factor by means of the recoil polarization method in the context of the CEBAF 8 GeV facility. For that purpose, they discuss the development of a high energy proton polarimeter, based on the H({rvec p},pp) elastic scattering, to be placed at the focal plane of a new hadron spectrometer. It is shown that this experimental method significantly improves the knowledge of the helicity non-conserving form factor of the proton up to 10 GeV{sup 2}/c{sup 2}.
$\\pi_{e3}$ form factor $f_{-}$ near mass shell
Krivoruchenko, M I
2014-01-01
Generalized Ward-Takahashi identity (gWTI) in the pion sector for broken isotopic symmetry is derived and used for the model-independent calculation of the longitudinal form factor $f_{-}$ of the $\\pi_{e3}$ vector vertex. The on-shell $f_{-}$ is found to be proportional to the mass difference of pions and the difference between vector isospin $ T = 1 $ and scalar isospin $ T = 2 $ pion radii. A numerical estimate of the form factor gives a value two times higher than the earlier estimate in the quark model. Off-shell form factors are known to be ambiguous because of the gauge dependence and the freedom in parameterization of the fields. The near-mass-shell $f_{-}$ appears to be an exception, allowing the experimental verification of the gWTI consequences. We calculate the near-mass-shell $f_{-}$ using the gWTI and dispersion techniques. The results are discussed in the context of the conservation of vector current (CVC) condition.
Meson Transition Form Factors in Light-Front Holographic QCD
Brodsky, Stanley J.; /SLAC; Cao, Fu-Guang; /Massey U.; de Teramond, Guy F.; /Costa Rica U.
2011-06-22
We study the photon-to-meson transition form factors (TFFs) F{sub M{gamma}}(Q{sup 2}) for {gamma}{gamma}* {yields} M using light-front holographic methods. The Chern-Simons action, which is a natural form in 5-dimensional anti-de Sitter (AdS) space, leads directly to an expression for the photon-to-pion TFF for a class of confining models. Remarkably, the predicted pion TFF is identical to the leading order QCD result where the distribution amplitude has asymptotic form. The Chern-Simons form is local in AdS space and is thus somewhat limited in its predictability. It only retains the q{bar q} component of the pion wavefunction, and further, it projects out only the asymptotic form of the meson distribution amplitude. It is found that in order to describe simultaneously the decay process {pi}{sup 0} {yields} {gamma}{gamma} and the pion TFF at the asymptotic limit, a probability for the q{bar q} component of the pion wavefunction P{sub q{bar q}} = 0.5 is required; thus giving indication that the contributions from higher Fock states in the pion light-front wavefunction need to be included in the analysis. The probability for the Fock state containing four quarks (anti-quarks) which follows from analyzing the hadron matrix elements, P{sub q{bar q}q{bar q}} {approx} 10%, agrees with the analysis of the pion elastic form factor using light-front holography including higher Fock components in the pion wavefunction. The results for the TFFs for the {eta} and {eta}{prime} mesons are also presented. The rapid growth of the pion TFF exhibited by the BABAR data at high Q{sup 2} is not compatible with the models discussed in this article, whereas the theoretical calculations are in agreement with the experimental data for the {eta} and {eta}{prime} TFFs.
Meson Transition Form Factors in Light-Front Holographic QCD
Brodsky, Stanley J.; /SLAC; Cao, Fu-Guang; /Massey U.; de Teramond, Guy F.; /Costa Rica U.
2011-06-22
We study the photon-to-meson transition form factors (TFFs) F{sub M{gamma}}(Q{sup 2}) for {gamma}{gamma}* {yields} M using light-front holographic methods. The Chern-Simons action, which is a natural form in 5-dimensional anti-de Sitter (AdS) space, leads directly to an expression for the photon-to-pion TFF for a class of confining models. Remarkably, the predicted pion TFF is identical to the leading order QCD result where the distribution amplitude has asymptotic form. The Chern-Simons form is local in AdS space and is thus somewhat limited in its predictability. It only retains the q{bar q} component of the pion wavefunction, and further, it projects out only the asymptotic form of the meson distribution amplitude. It is found that in order to describe simultaneously the decay process {pi}{sup 0} {yields} {gamma}{gamma} and the pion TFF at the asymptotic limit, a probability for the q{bar q} component of the pion wavefunction P{sub q{bar q}} = 0.5 is required; thus giving indication that the contributions from higher Fock states in the pion light-front wavefunction need to be included in the analysis. The probability for the Fock state containing four quarks (anti-quarks) which follows from analyzing the hadron matrix elements, P{sub q{bar q}q{bar q}} {approx} 10%, agrees with the analysis of the pion elastic form factor using light-front holography including higher Fock components in the pion wavefunction. The results for the TFFs for the {eta} and {eta}{prime} mesons are also presented. The rapid growth of the pion TFF exhibited by the BABAR data at high Q{sup 2} is not compatible with the models discussed in this article, whereas the theoretical calculations are in agreement with the experimental data for the {eta} and {eta}{prime} TFFs.
Marcel Ginotti Pires
2017-01-01
Full Text Available This article discusses the factors present in post-merger integration of Systems and Information Technology (SIT that lead to positive and negative results in mergers and acquisitions (M & A. The research comprised three of the largest acquiring banks in Brazil. We adopted two methods of research, qualitative, to operationalize the theoretical concepts and quantitative, to test the hypotheses. We interviewed six executives of banks that held relevant experience in M & A processes. Subsequently, we applied questionnaires to IT professionals who were involved in the SIT integration processes. The results showed that the quality and expertise of the integration teams and managing the integration were the most relevant factors in the processes, with positive results for increased efficiency and the increased capacity of SIT. Negative results were due to failures in exploiting learning opportunities, the loss of employees and the inexpressive record of integration procedures.
Some relevant risk factors and causal mechanisms to understand crime in Romania
Alassane Diaw; Oana-Ramona Lobont; Nicoleta Claudia Moldovan
2014-01-01
The objective of this paper is to provide some empirical evidence of relevant risk factors and causal mechanisms to understand criminal behavior in Romania. In order to achieve this goal, some socio-economic variables are considered: long-term unemployment rate and people at risk of poverty or social exclusion and, as crime variables we use four different types of crimes: domestic burglary, homicide, motor vehicle theft and robbery. At the regional level, the results of our panel data analysi...
Clinical Relevant Fatigue in Women with Breast Cancer: Prevalence and Associated Factors
Lamino, Daniela de Araujo; Sra Cibele, Cibele Andruciolli de Mattos Pimenta; Sra Patricia, Patricia Emilia Braga; Sra Dalete, Dalete Delalibera Corrêa de Faria Mota
2014-01-01
Introduction: Fatigue is a common symptom in patients with cancer. Objective: Toexamine the prevalence and independent predictors of fatigue in women with breastcancer. Material and Method: A cross-sectional study with a nonrandom sample of163 patients in outpatient follow-up. Fatigue was assessed by the Piper Fatigue Scale.Results: Clinical relevant fatigue (score ≥ 4) was present in 31.9% of the sample andthe average intensity was 6 (SD = 1.3).Pain and depression were factors independentlya...
Wataru Gonoi
Full Text Available BACKGROUND: Meandering main pancreatic duct (MMPD, which comprises loop type and reverse-Z type main pancreatic duct (MPD, has long been discussed its relation to pancreatitis. However, no previous study has investigated its clinical significance. We aimed to determine the non-biased prevalence and the effect of MMPD on idiopathic pancreatitis using non-invasive magnetic resonance (MR technique. METHODS AND FINDINGS: A cross-sectional study performed in a tertiary referral center. The study enrolled 504 subjects from the community and 30 patients with idiopathic pancreatitis (7 acute, 13 chronic, and 10 recurrent acute. All subjects underwent MR scanning and medical examination. MMPD was diagnosed when the MPD in the head of pancreas formed two or more extrema in the horizontal direction on coronal images of MR cholangiopancreatography, making a loop or a reverse-Z shaped hairpin curves and not accompanied by other pancreatic ductal anomaly. Statistical comparison was made among groups on the rate of MMPD including loop and reverse-Z subtypes, MR findings, and clinical features. The rate of MMPD was significantly higher for all idiopathic pancreatitis/idiopathic recurrent acute pancreatitis (RAP (20%/40%; P<0.001/0.0001; odds ratio (OR, 11.1/29.0 than in the community (2.2% but was not higher for acute/chronic pancreatitis (14%/8%; P = 0.154/0.266. Multiple logistic regression analysis revealed MMPD to be a significant factor that induces pancreatitis/RAP (P<0.0001/0.0001; OR, 4.01/26.2. Loop/reverse-Z subtypes were found more frequently in idiopathic RAP subgroup (20%/20%; P = 0.009/0.007; OR, 20.2/24.2 than in the community (1.2%/1.0%. The other clinical and radiographic features were shown not associated with the onset of pancreatitis. CONCLUSIONS: MMPD is a common anatomical variant and might be a relevant factor to the onset of idiopathic RAP.
Effectiveness and relevant factors of 2% rebamipide ophthalmic suspension treatment in dry eye.
Ueda, Kaori; Matsumiya, Wataru; Otsuka, Keiko; Maeda, Yoshifumi; Nagai, Takayuki; Nakamura, Makoto
2015-06-06
Rebamipide with mucin secretagogue activity was recently approved for the treatment of dry eye. The efficacy and safety in the treatment of rebamipide were shown in two pivotal clinical trials. It was the aim of this study to evaluate the effect of 2% rebamipide ophthalmic suspension in patients with dry eye and analyze relevant factors for favorable effects of rebamipide in clinical practice. This was a retrospective cohort study of 48 eyes from 24 patients with dry eye treated with 2% rebamipide ophthalmic suspension. Dry eye-related symptom score, tear film break-up time (TBUT), fluorescein ocular surface staining score (FOS) and the Schirmer test were used to collect the data from patients at baseline, and at 2, 4, 8, and 12 week visits. To determine the relevant factors, multiple regression analyses were then performed. Mean dry eye-related symptom score showed a significant improvement from the baseline (14.5 points) at 2, 4, 8 and 12 weeks (9.80, 7.04, 7.04 and 7.83 points, corrected P value rebamipide ophthalmic suspension was an effective therapy for dry eye patients. Moreover the fluorescein conjunctiva staining score and dry eye-related symptom score might be good relevant factors for favorable effects of rebamipide.
Electromagnetic rho-meson form factors in point-form relativistic quantum mechanics
Biernat, Elmar P
2014-01-01
The relativistic point-form formalism which we proposed for the study of the electroweak structure of few-body bound states is applied to calculate the elastic form factors of spin-1 mesons, such as the rho, within constituent-quark models. We treat electron-meson scattering as a Poincare-invariant coupled-channel problem for a Bakamjian-Thomas mass operator and extract the meson current from the resulting invariant 1-photon-exchange amplitude. Wrong cluster properties inherent in the Bakamjian-Thomas framework are seen to cause spurious contributions in the current. These contributions, however, can be separated unambiguously from the physical ones and we end up with a meson current with all required properties. Numerical results for the rho-meson form factors are presented assuming a simple harmonic-oscillator bound-state wave function. The comparison with other approaches reveals a remarkable agreement of our results with those obtained within the covariant light-front scheme proposed by Carbonell et al.
Forms and factors of peer violence and victimisation
Dinić Bojana
2014-01-01
Full Text Available The main aim of this study was to explore the latent structure of violence and victimisation based on the factor analysis of the Peer Violence and Victimisation Questionnaire (PVVQ, as well as to examine the correlates of violence and victimisation. The sample included 649 secondary school students (61.8% male from the urban area. Besides the PVVQ, the Aggressiveness questionnaire AVDH was administered. Based on parallel analysis, three factors were extracted in the violence domain, as well as in the victimisation domain of the PVVQ. The factors were interpreted as a physical, verbal and relational form of violence and victimisation, which is in line with common classifications. The correlations of those forms with the aggressiveness dimensions were positive. The relationships with gender, school grade and school achievement referred to the importance of interaction effects between the mentioned characteristics of students and the tendency towards violence or being exposed to it. The main result is that boys from lower school grades and students with lower school achievement in general, are more prone to manifesting physical violence and more often are the target of physical violence. These groups of students are the target groups for preventive programs. The resulting effects indicated the complexity of the violence phenomenon and pointed to the need to consider the wider context of student’s characteristics in the determination of violence. [Projekat Ministarstva nauke Republike Srbije, br. 179037 i br. 179053
Identification of relevant factors and diversified portfolio selection in brazilian stock market
Alysson Ramos Artuso
2012-11-01
Full Text Available Starting from fundamental variables, this research aims to construct unobservable factors to explain the most part of the accounting data’s variability of listed companies on Bovespa. So, it was applied the multivariate statistical technique factor analysis by means principal components, in which eight factors were relevant. Based on the scores of these factors, the assets were ranked and annual portfolios with twelve actions were selected. This strategy had positive abnormal returns at 5% of significance level in the period 1999 to 2009, bringing evidence of inefficiencies in the Brazilian stock market. Thus, the techniques provide an option for understanding the stock market and the portfolios’ selection through the analysis of multiple variables.
Silva, A; Urbano, D; Göke, K; Silva, Antonio; Kim, Hyun-CHul; Urbano, Diana; Goeke, Klaus
2005-01-01
We investigate three different axial-vector form factors of the nucleon, $G_A^{0}$, $G_A^3$, $G_A^8$, within the framework of the SU(3) chiral quark-soliton model, emphasizing their strangeness content. We take into account the rotational $1/N_c$ and linear strange quark ($m_s$) contributions using the symmetry-conserving SU(3) quantization and assuming isospin symmetry. The strange axial-vector form factor is also obtained and they all are discussed in the context of the parity-violating scattering of polarized electrons off the nucleon and its relevance to the strange vector form factors.
Clostridial pore-forming toxins: powerful virulence factors.
Popoff, Michel R
2014-12-01
Pore formation is a common mechanism of action for many bacterial toxins. More than one third of clostridial toxins are pore-forming toxins (PFTs) belonging to the β-PFT class. They are secreted as soluble monomers rich in β-strands, which recognize a specific receptor on target cells and assemble in oligomers. Then, they undergo a conformational change leading to the formation of a β-barrel, which inserts into the lipid bilayer forming functional pore. According to their structure, clostridial β-PFTs are divided into several families. Clostridial cholesterol-dependent cytolysins form large pores, which disrupt the plasma membrane integrity. They are potent virulence factors mainly involved in myonecrosis. Clostridial heptameric β-PFTs (aerolysin family and staphylococcal α-hemolysin family) induce small pores which trigger signaling cascades leading to different cell responses according to the cell types and toxins. They are mainly responsible for intestinal diseases, like necrotic enteritis, or systemic diseases/toxic shock from intestinal origin. Clostridial intracellularly active toxins exploit pore formation through the endosomal membrane to translocate the enzymatic component or domain into the cytosol. Single chain protein toxins, like botulinum and tetanus neurotoxins, use hydrophobic α-helices to form pores, whereas clostridial binary toxins encompass binding components, which are structurally and functionally related to β-PFTs, but which have acquired the specific activity to internalize their corresponding enzymatic components. Structural analysis suggests that β-PFTs and binding components share a common evolutionary origin.
Dispersive analysis of the scalar form factor of the nucleon
Hoferichter, M; Kubis, B; Meißner, U -G
2012-01-01
Based on the recently proposed Roy-Steiner equations for pion-nucleon scattering, we derive a system of coupled integral equations for the pi pi --> N-bar N and K-bar K --> N-bar N S-waves. These equations take the form of a two-channel Muskhelishvili-Omnes problem, whose solution in the presence of a finite matching point is discussed. We use these results to update the dispersive analysis of the scalar form factor of the nucleon fully including K-bar K intermediate states. In particular, we determine the correction Delta_sigma=sigma(2M_pi^2)-sigma_{pi N}, which is needed for the extraction of the pion-nucleon sigma term from pi N scattering, as a function of pion-nucleon subthreshold parameters and the pi N coupling constant.
Electric and magnetic form factors of the proton
Bernauer, J C; Friedrich, J.; Walcher, Th.; Achenbach, P.; Gayoso, C. Ayerbe; Böhm, R.; Bosnar, D.; Debenjak, L.; Doria, L.; Esser, A.; Fonvieille, H.; Gomez Rodriguez de la Paz, M.; Friedrich, J.M.; Makek, M.; Merkel, H.; Middleton, D.G.; Müller, U.; Nungesser, L.; Pochodzalla, J.; Potokar, M.; Sanchez Majos, S.; Schlimme, B.S.; Sirca, S.; Weinriefer, M.
2014-01-01
The paper describes a precise measurement of electron scattering off the proton at momentum transfers of $0.003 \\lesssim Q^2 \\lesssim 1$\\ GeV$^2$. The average point-to-point error of the cross sections in this experiment is $\\sim$ 0.37%. These data are used for a coherent new analysis together with all world data of unpolarized and polarized electron scattering from the very smallest to the highest momentum transfers so far measured. The extracted electric and magnetic form factors provide new insight into their exact shape, deviating from the classical dipole form, and of structure on top of this gross shape. The data reaching very low $Q^2$ values are used for a new determination of the electric and magnetic radii. An empirical determination of the Two-Photon-Exchange (TPE) correction is presented. The implications of this correction on the radii and the question of a directly visible signal of the pion cloud are addressed.
Bonner Prize: The Elastic Form Factors of the Nucleon
Perdrisat, Charles F.
2017-01-01
A series of experiments initiated in 1998 at the then new Continuous Electron Beam Accelerator, or CEBAF in Newport News Virginia, resulted in unexpected results, changing significantly our understanding of the structure of the proton. These experiments used a relatively new technique to obtain the ratio of the two form factors of the proton, namely polarization. An intense beam of highly polarized electrons with energy up to 6 GeV was made to interact elastically with un-polarized protons in a hydrogen target. The polarization of the recoiling protons, with energies up to 5 GeV, was measured from a second interaction in a polarimeter consisting of blocs of graphite or CH2 and tracking wire chambers. The scattered electrons were detected in an electromagnetic lead-glass calorimeter, to select elastically scattered events. After a short introduction describing the path which brought me from the University of Geneva to the College of William and Mary in 1966, I will introduce the subject of elastic electron scattering, describe some of the apparatus required for such experiments, and show the results which were unexpected at the time. These results demonstrated unequivocally that the two form factors required to describe elastic ep scattering, electric GE and magnetic GM in the Born approximation, had a drastically different dependence upon the four-momentum squared q2 = q2 -ω2 with q the momentum, and ω the energy transferred in the reaction. The finding, in flagrant disagreement with the data available at the time, which had been obtained dominantly from cross section measurements of the type first used by Nobel Prize R. Hofstadter 60 years ago, have led to a reexamination of the information provided by form factors on the structure of the nucleon, in particular its quark-gluon content. The conclusion will then be a brief outline of several theoretical considerations to put the results in a proper perspective.
Scattering form factors for self-assembled network junctions
Foster, T.; Safran, S. A.; Sottmann, T.; Strey, R.
2007-11-01
The equilibrium microstructures in microemulsions and other self-assembled systems show complex, connected shapes such as symmetric bicontinuous spongelike structures and asymmetric bicontinuous networks formed by cylinders interconnected at junctions. In microemulsions, these cylinder network microstructures may mediate the structural transition from a spherical or globular phase to the bicontinuous microstructure. To understand the structural and statistical properties of such cylinder network microstructures as measured by scattering experiments, models are needed to extract the real-space structure from the scattering data. In this paper, we calculate the scattering functions appropriate for cylinder network microstructures. We focus on such networks that contain a high density of network junctions that connect the cylindrical elements. In this limit, the network microstructure can be regarded as an assembly of randomly oriented, closed packed network junctions (i.e., the cylinder scattering contributions are neglected). Accordingly, the scattering spectrum of the network microstructure can be calculated as the product of the junction number density, the junction form factor, which describes the scattering from the surface of a single junction, and a structure factor, which describes the local correlations of different junctions due to junction interactions (including their excluded volume). This approach is applied to analyze the scattering data from a bicontinuous microemulsion with equal volumes of water and oil. In a second approach, we included the cylinder scattering contribution in the junction form factor by calculating the scattering intensity of Y junctions to which three rods with spherical cross section are attached. The respective theoretical predictions are compared with results of neutron scattering measurements on a water-in-oil microemulsion with a connected microstructure.
THE ROLE OF INSTITUTIONAL FACTORS IN THE CREATION OF NEW FORMS OF ENTREPRENEURSHIP
M. A. Yakhjyaev
2016-01-01
Full Text Available Supporting entrepreneurship in diff erent countries of the world it is realized through the participation of financial and non-financial institutions, which together form the infrastructure for the development of small and medium-sized businesses. In this context, one can not underestimate the infl uence of institutional factors that have a stimulating eff ect on the modeling and the creation of new forms of entrepreneurship.Objectives. The aim of the article is to research and analysis of modern concepts and identifying common trends in the creation of new forms of entrepreneurship.Methodology. Theoretical and methodological basis of research are general scientific principles and laws of economics, analysis and synthesis, review of scientific concepts, leading Russian and foreign specialists in the sphere of small and medium-sized businesses.Results. The role of institutional factors in the creation of new forms of entrepreneurship. The features of the creation of new forms and areas of business through the use of eff ective tools of XXI century, identifies key factors and trends in the development of this market.Conclusions / relevance. The relevance of the article due to the fact that in modern conditions, when the national economy is in the stage of turbulence, it is necessary to find new solutions that will ensure the sustainability of national social and economic development in line with global trends. The theme of the article is selected aspect of sustainable economic development in Russia in view of increase of innovative activity of business that will be achieved, including through the creation of new forms of entrepreneurship.
Measurement of the π0 electromagnetic transition form factor slope
C. Lazzeroni
2017-05-01
Full Text Available The NA62 experiment collected a large sample of charged kaon decays in 2007 with a highly efficient trigger for decays into electrons. A measurement of the π0 electromagnetic transition form factor slope parameter from 1.11×106 fully reconstructed K±→π±πD0, πD0→e+e−γ events is reported. The measured value a=(3.68±0.57×10−2 is in good agreement with theoretical expectations and previous measurements, and represents the most precise experimental determination of the slope in the time-like momentum transfer region.
Baryon octet electromagnetic form factors in a confining NJL model
Manuel E. Carrillo-Serrano
2016-08-01
Full Text Available Electromagnetic form factors of the baryon octet are studied using a Nambu–Jona-Lasinio model which utilizes the proper-time regularization scheme to simulate aspects of colour confinement. In addition, the model also incorporates corrections to the dressed quarks from vector meson correlations in the t-channel and the pion cloud. Comparison with recent chiral extrapolations of lattice QCD results shows a remarkable level of consistency. For the charge radii we find the surprising result that rEp
Kaon Eletromagnetic Form Factor in the Light-Front Formalism
Pereira, F P; Frederico, T; Tomio, L; Pereira, Fabiano P.; Tomio, Lauro
2005-01-01
Numerical calculations are performed and compared to the experimental data for the electromagnetic form factor of the kaon, which is extracted from both components of the electromagnetic current, $J^{+}$ and $J^{-}$, with a pseudo-scalar coupling of the quarks to the kaon. In the case of $J^{+}$ there is no pair term contribution in the Drell-Yan frame ($q^{+}=0$). However, for $J^{-}$, the pair term contribution is different from zero and necessary in order to preserve the rotational symmetry of the current. The free parameters are the quark masses and the regulator mass.
The JLab polarization transfer measurements of proton elastic form factor
C F Perdrisat; V Punjabi
2003-11-01
The ratio of the electric and magnetic proton form factors, /, has been obtained in two Hall A experiments, from measurements of the longitudinal and transverse polarizations of the recoil proton, ℓ and , in the elastic scattering of polarized electrons, $\\overrightarrow{e}p→ e\\overrightarrow{p}$. Together these experiments cover the 2 range of 0.5 to 5.6 GeV2. A new experiment is currently being prepared, to extend the 2 range to 9 GeV2 in Hall C.
CEBAF at higher energies and the kaon electromagnetic form factor
Baker, O.K.
1994-04-01
The electromagnetic production of strangeness, the physics of exciting systems having strangeness degrees of freedom (production of hadrons with one or more strange constituent quarks) using electromagnetic probes (real or virtual photons), is one of the frontier areas of research which will be investigated at the Continuous Electron Beam Accelerator Facility (CEBAF) when it becomes operational. CEBAF is expected to have an important impact upon this field of research using its specialized set of detection instruments and high quality electron beam. This paper focusses upon one aspect of the associated production of strangeness - the determination of the kaon electromagnetic form factor at high squared momentum transfers.
Nucleon electromagnetic form factors in twisted mass lattice QCD
Alexandrou, C; Carbonell, J; Constantinou, M; Harraud, P A; Guichon, P; Jansen, K; Korzec, T; Papinutto, M
2011-01-01
We present results on the nucleon electromagnetic form factors within lattice QCD using two flavors of degenerate twisted mass fermions. Volume effects are examined using simulations at two volumes of spatial length L=2.1 fm and L=2.8 fm. Cut-off effects are investigated using three different values of the lattice spacings, namely a=0.089 fm, a=0.070 and a=0.056 fm. The nucleon magnetic moment, Dirac and Pauli radii are obtained in the continuum limit and chirally extrapolated to the physical pion mass allowing for a comparison with experiment.
Nucleon form factors with Nf=2 dynamical twisted mass fermions
Alexandrou, C; Koutsou, G; Baron, R; Guichon, P; Brinet, M; Carbonell, J; Harraud, P -A; Jansen, K
2009-01-01
We present results on the electromagnetic and axial nucleon form factors using two degenerate flavors of twisted mass fermions on lattices of spatial size 2.1 fm and 2.7 fm and a lattice spacing of about 0.09 fm. We consider pion masses in the range of 260-470 MeV. We chirally extrapolate results on the nucleon axial ch arge, the isovector Dirac and Pauli root mean squared radii and magnetic moment to the physical point and co mpare to experiment.
Minimal form factor digital-image sensor for endoscopic applications
Wäny, Martin; Voltz, Stephan; Gaspar, Fabio; Chen, Lei
2009-02-01
This paper presents a digital image sensor SOC featuring a total chip area (including dicing tolerances) of 0.34mm2 for endoscopic applications. Due to this extremely small form factor the sensor enables integration in endoscopes, guide wires and locater devices of less than 1mm outer diameter. The sensor embeds a pixel matrix of 10'000 pixels with a pitch of 3um x 3um covered with RGB filters in Bayer pattern. The sensor operates fully autonomous, controlled by an on chip ring oscillator and readout state machine, which controls integration AD conversion and data transmission, thus the sensor only requires 4 pin's for power supply and data communication. The sensor provides a frame rate of 40Frames per second over a LVDS serial data link. The endoscopic application requires that the sensor must work without any local power decoupling capacitances at the end of up to 2m cabling and be able to sustain data communication over the same wire length without deteriorating image quality. This has been achieved by implementation of a current mode successive approximation ADC and current steering LVDS data transmission. An band gap circuit with -40dB PSRR at the data frequency was implemented as on chip reference to improve robustness against power supply ringing due to the high series inductance of the long cables. The B&W versions of the sensor provides a conversion gain of 30DN/nJ/cm2 at 550nm with a read noise in dark of 1.2DN when operated at 2m cable. Using the photon transfer method according to EMVA1288 standard the full well capacity was determined to be 18ke-. According to our knowledge the presented work is the currently world smallest fully digital image sensor. The chip was designed along with a aspheric single surface lens to assemble on the chip without increasing the form factor. The extremely small form factor of the resulting camera permit's to provide visualization with much higher than state of the art spatial resolution in sub 1mm endoscopic
Tests of Higgs boson compositeness through the HHH form factor
Gounaris, G J
2015-01-01
We show how the $q^2$-dependence of the triple Higgs boson HHH form factor can reveal the presence of various types of new physics contributions, like new particles coupled to the Higgs boson or Higgs boson constituents, without directly observing them. We compare the effect of such new contributions to the one of higher order SM corrections to the point-like HHH coupling, due to triangle, 4-leg and s.e. diagrams. We establish simple analytic expressions describing accurately at high energy these SM corrections, as well as the examples of new physics contributions.
Neutral pion form factor measurement at NA62
Goudzovski, Evgueni
2016-01-01
The NA62 experiment at CERN collected a large sample of charged kaon decays with a highly efficient trigger for decays into electrons in 2007. The kaon beam represents a source of tagged neutral pion decays in vacuum. A measurement of the electromagnetic transition form factor slope of the neutral pion in the time-like region from $1.05\\times10^6$ fully reconstructed $\\pi^0$ Dalitz decay is presented. The limits on dark photon production in $\\pi^0$ decays from the earlier kaon experiment at CERN, NA48/2, are also reported.
Introducing soil forming factors with mini campus field trips
Quinton, John; Haygarth, Phil
2013-04-01
Students like field work, yet the proportion of time spent in the field during many soil science courses is small. Here we describe an introductory lecture on the soil forming factors based around a mini field trip in which we spend 45 minutes exploring these factors on the Lancaster University campus. In the 'trip' we visit some woodland to consider the effects of organic matter , vegetation and time on soil development and then take in a football pitch to examine the effects of landscape position, parent material and climate. Student responses are overwhelmingly positive and we suggest that more use can be made of our often mundane surroundings to explore soil formation. Soil functions and soil processes.
Naser, Iftekhar Bin; Hoque, M Mozammel; Abdullah, Ahmed; Bari, S M Nayeemul; Ghosh, Amar N; Faruque, Shah M
2017-01-01
Phages isolated from environmental waters in Bangladesh were tested for their host specificity towards V. cholerae O1 and O139, and the ability to disperse V. cholerae biofilms formed in the laboratory. Representative phages were further characterized by electron microscopy and whole genome sequencing. Selected phages were then introduced in various combinations to biofilms of toxigenic V. cholerae added to samples of river water, and the dispersion of biofilms as well as the growth kinetics of V. cholerae and the phages were monitored. A phage cocktail composed of three different phages isolated from surface waters in Bangladesh and designated as JSF7, JSF4, and JSF3 could significantly influence the distribution and concentration of the active planktonic form and biofilm associated form of toxigenic V. cholerae in water. While JSF7 showed a biofilm degrading activity and dispersed cells from both V. cholerae O1 and O139 derived biofilms thus increasing the concentration of planktonic V. cholerae in water, JSF4 and JSF3 showed strong bactericidal activity against V. cholerae O1 and O139 respectively. A mixture of all three phages could effectively reduce both biofilm-associated and planktonic V. cholerae in river water microcosms. Besides potential applicability in phage-mediated control of cholera, our results have relevance in appreciating possible intricate role of diverse environmental phages in the epidemiology of the disease, since both biofilms and phages influence the prevalence and infectivity of V. cholerae in a variety of ways.
Measurement of the Neutral Weak Form Factors of the Proton
Deur, Alexandre; Fleck, Andre; Saha, Arunava; Gasparian, Ashot; Frois, Bernard; Wojtsekhowski, Bogdan; Vlahovic, Branislav; Perdrisat, Charles; Cavata, Christian; Jutier, Christophe; De Jager, Cornelis; Neyret, Damien; Dale, Daniel; Armstrong, David; Lhuillier, David; Prout, David; Margaziotis, Demetrius; Kim, Donghee; Burtin, Etienne; Chudakov, Eugene; Hersman, F.; Garibaldi, Franco; Marie, Frederic; Miller, Greg; Rutledge, Gary; Gerstner, George; Petratos, Gerassimos; Quemener, Gilles; Cates, Gordon; Thompson, J.; Martino, Jacques; Gomez, Javier; Jorda, Jean-Paul; Hansen, Jens-Ole; Chen, Jian-Ping; Jardillier, Johann; Calarco, John; LeRose, John; Price, John; Gao, Juncai; McIntyre, Justin; McCormick, Kathy; Fissum, Kevin; Kramer, Kevin; Aniol, Konrad; Kumar, Krishna; Wijesooriya, Krishni; Ewell, Lars; Todor, Luminita; Spradlin, Marcus; Jones, Mark; Leuschner, Mark; Epstein, Martin; Baylac, Maud; Holtrop, Maurik; Finn, Michael; Kuss, Michael; Kim, Min; Falletto, Nicolas; Liyanage, Nilanga; Glamazdin, Oleksandr; Rutt, Paul; Souder, Paul; Ulmer, Paul; Mastromarino, Peter; Djawotho, Pibero; Wilson, Richard; Suleiman, Riad; Holmes, Richard; Madey, Richard; Lourie, Robert; Michaels, Robert; Pomatsalyuk, Roman; Gilman, Ronald; Incerti, Sebastien; Escoffier, Stephanie; Pussieux, Thierry; Humensky, Thomas; Gorbenko, Viktor; Punjabi, Vina; Kahl, William; Meziani, Zein-Eddine
1999-02-01
We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The kinematic point [(Theta_{lab}) = 12.3r and (Q^{2}) = 0.48 (GeV/c)^{2}] is chosen to provide sensitivity, at a level that is of theoretical interest, to the strange electric form factor G^{s}_{E}. The result, A = - 14.5 + or - 2.2 ppm, is consistent with the electroweak standard model and no additional contributions from strange quarks. In particular, the measurement implies G^{s}_{E} + 0.39G^{s}_{M} = 0.023 + or - 0.034(stat) + or - 0.022(syst) + or - 0.026(delta-G^{n}_{E}), where the last uncertainty arises from the estimated uncertainty in the neutron electric form factor.
Vector meson dominance and the pi^0 transition form factor
Lichard, Peter
2010-01-01
It is shown that the pi^0 transition form factor F(Q_1^2,Q_2^2) differs substantially from its one-real-photon limit F(Q_1^2,0) even for rather small values of Q_2^2 (approx 0.1 GeV^2), which cannot be excluded in experiments with one "untagged" electron. It indicates that the comparison of data with theoretical calculations, which usually assume Q_2^2=0, may be untrustworthy. Our phenomenological model of the pi^0 transition form factor is based on the vector-meson-dominance (VMD) hypothesis and all its parameters are fixed by using the experimental data on the decays of vector mesons. The model soundness is checked in the two-real-photon limit, where it provides a good parameter-free description of the pi^0 -> 2 gamma decay rate, and in the pi^0 Dalitz decay. The dependence of F(Q_1^2,Q_2^2) on Q_1^2 at several fixed values of Q_2^2 is presented and the comparison with existing data performed.
Measurement of the $\\Lambda_{b}^{0}$ Decay Form Factor
Abdallah, J; Adam, W; Adzic, P; Albrecht, T; Alderweireld, T; Alemany-Fernandez, R; Allmendinger, T; Allport, P P; Amaldi, Ugo; Amapane, N; Amato, S; Anashkin, E; Andreazza, A; Andringa, S; Anjos, N; Antilogus, P; Apel, W D; Arnoud, Y; Ask, S; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Ballestrero, A; Bambade, P; Barbier, R; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Ben-Haim, E; Benekos, N C; Benvenuti, Alberto C; Bérat, C; Berggren, M; Berntzon, L; Bertrand, D; Besançon, M; Besson, N; Bloch, D; Blom, M; Bluj, M; Bonesini, M; Boonekamp, M; Booth, P S L; Borisov, G; Botner, O; Bouquet, B; Bowcock, T J V; Boyko, I; Bracko, M; Brenner, R; Brodet, E; Brückman, P; Brunet, J M; Bugge, L; Buschmann, P; Calvi, M; Camporesi, T; Canale, V; Carena, F; Castro, N; Cavallo, F R; Chapkin, M M; Charpentier, P; Checchia, P; Chierici, R; Shlyapnikov, P; Chudoba, J; Chung, S U; Cieslik, K; Collins, P; Contri, R; Cosme, G; Cossutti, F; Costa, M J; Crawley, B; Crennell, D J; Cuevas-Maestro, J; D'Hondt, J; Dalmau, J; Da Silva, T; Da Silva, W; Della Ricca, G; De Angelis, A; de Boer, Wim; De Clercq, C; De Lotto, B; De Maria, N; De Min, A; De Paula, L S; Di Ciaccio, Lucia; Di Simone, A; Doroba, K; Drees, J; Dris, M; Eigen, G; Ekelöf, T J C; Ellert, M; Elsing, M; Espirito-Santo, M C; Fanourakis, G K; Fassouliotis, D; Feindt, M; Fernández, J; Ferrer, A; Ferro, F; Flagmeyer, U; Föth, H; Fokitis, E; Fulda-Quenzer, F; Fuster, J A; Gandelman, M; García, C; Gavillet, P; Gazis, E N; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; Graziani, E; Grosdidier, G; Grzelak, K; Guy, J; Haag, C; Hallgren, A; Hamacher, K; Hamilton, K; Haug, S; Hauler, F; Hedberg, V; Hennecke, M; Herr, H; Hoffman, J; Holmgren, S O; Holt, P J; Houlden, M A; Hultqvist, K; Jackson, J N; Jarlskog, G; Jarry, P; Jeans, D; Johansson, E K; Johansson, P D; Jonsson, P; Joram, C; Jungermann, L; Kapusta, F; Katsanevas, S; Katsoufis, E C; Kernel, G; Kersevan, Borut P; Kerzel, U; Kiiskinen, A P; King, B T; Kjaer, N J; Kluit, P; Kokkinias, P; Kourkoumelis, C; Kuznetsov, O; Krumshtein, Z; Kucharczyk, M; Lamsa, J; Leder, G; Ledroit, F; Leinonen, L; Leitner, R; Lemonne, J; Lepeltier, V; Lesiak, T; Liebig, W; Liko, D; Lipniacka, A; Lopes, J H; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J; Malek, A; Maltezos, S; Mandl, F; Marco, J; Marco, R; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Masik, J; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Mazzucato, F; Mazzucato, M; McNulty, R; Meroni, C; Meyer, W T; Myagkov, A; Migliore, E; Mitaroff, W A; Mjörnmark, U; Moa, T; Moch, M; Mönig, K; Monge, R; Montenegro, J; Moraes, D; Moreno, S; Morettini, P; Müller, U; Münich, K; Mulders, M; Mundim, L M; Murray, W; Muryn, B; Myatt, Gerald; Myklebust, T; Nassiakou, M; Navarria, Francesco Luigi; Nawrocki, K; Nicolaidou, R; Nikolenko, M; Oblakowska-Mucha, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Österberg, K; Ouraou, A; Oyanguren, A; Paganoni, M; Paiano, S; Palacios, J P; Palka, H; Papadopoulou, T D; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Peralta, L; Perepelitsa, V F; Perrotta, A; Petrolini, A; Piedra, J; Pieri, L; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Poireau, V; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Pukhaeva, N; Pullia, Antonio; Rames, J; Ramler, L; Read, A; Rebecchi, P; Rehn, J; Reid, D; Reinhardt, R; Renton, P B; Richard, F; Rídky, J; Rivero, M; Rodríguez, D; Romero, A; Ronchese, P; Rosenberg, E I; Roudeau, Patrick; Rovelli, T; Ruhlmann-Kleider, V; Ryabtchikov, D; Sadovskii, A; Salmi, L; Salt, J; Savoy-Navarro, A; Schwickerath, U; Segar, A; Sekulin, R L; Siebel, M; Sissakian, A N; Smadja, G; Smirnova, O G; Sokolov, A; Sopczak, A; Sosnowski, R; Spassoff, Tz; Stanitzki, M; Stocchi, A; Strauss, J; Stugu, B; Szczekowski, M; Szeptycka, M; Szumlak, T; Tabarelli de Fatis, T; Taffard, A C; Tegenfeldt, F; Timmermans, J; Tkatchev, L G; Tobin, M; Todorovova, S; Tomé, B; Tonazzo, A; Tortosa, P; Travnicek, P; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Turluer, M L; Tyapkin, I A; Tyapkin, P; Tzamarias, S; Uvarov, V; Valenti, G; van Dam, P; Van Eldik, J; Van Lysebetten, A; Van Remortel, N; Van Vulpen, I B; Vegni, G; Veloso, F; Venus, W A; Verdier, P; Verzi, V; Vilanova, D; Vitale, L; Vrba, V; Wahlen, H; Washbrook, A J; Weiser, C; Wicke, D; Wickens, J H; Wilkinson, G; Winter, M; Witek, M; Yushchenko, O P; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zhuravlov, V; Zimin, N I; Zinchenko, A I; Zupan, M
2004-01-01
The form factor of Lambda_b^0 baryons is estimated using 3.46 10^6 hadronic Z decays collected by the DELPHI experiment between 1992 and 1995. Charmed Lambda_c^+ baryons fully reconstructed in the pK-pi+, pK0_S, and Lambda pi+pi+pi- modes, are associated to a lepton with opposite charge in order to select Lambda_b^0 -> Lambda_c^+ l^- anti-nu_l decays. From a combined likelihood and event rate fit to the distribution of the Isgur-Wise variable w, and using the Heavy Quark Effective Theory (HQET), the slope of the b-baryon form factor is measured to be: rho-hat^2 = 2.03 +/- 0.46 (stat) ^{+0.72}_{-1.00} (syst). The exclusive semileptonic branching fraction Br(Lambda_b^0 -> Lambda_c^+ l^- anti-nu_l) can be derived from rho-hat^2 and is found to be (5.0^{+1.1}_{-0.8} (stat) ^{+1.6}_{-1.2} (syst))%. Limits on other branching fractions are also obtained.
Gaugain, Murielle; Gautier, Sophie; Bourcier, Sophie; Jacques, Anne-Marie; Laurentie, Michel; Abjean, Jean-Pierre; Hurtaud-Pessel, Dominique; Verdon, Eric
2015-01-01
Chlortetracycline (CTC) is a broad-spectrum antibiotic used in veterinary medicine for pulmonary or digestive infections and having a regulatory maximum residue limit (MRL) necessitating an official analytical control method. The purpose of this study was to clarify the identification of different forms of CTC observed in standard solution, in spiked muscle samples and in naturally incurred muscle samples of pigs analysed by LC-MS/MS and to demonstrate the in vivo formation of 6-iso-chlortetracycline and 4-epi-6-iso-CTC as a metabolite of CTC and 4-epi-CTC in muscle. The six following forms were identified, all being isobaric with a protonated molecule at m/z 479 (precursor ion): the keto-enol forms of CTC and the keto-enol forms of 4-epi-chlortetracycline (4-epi-CTC), 6-iso-chlortetracycline (6-iso-CTC) and 4-epi-6-iso-chlortetracycline (4-epi-6-iso-CTC). The 6-iso-CTC and 4-epi-6-iso-CTC were observed only in incurred pig samples so were identified for the first time as metabolites of CTC and 4-epi-CTC. Identification of the different forms was obtained by comparing incurred muscle samples with standard solutions and with spiked samples. Then the differences between the features of the chromatograms obtained by LC-TQ-MS and the fragmentation study of the different forms of CTC obtained by LC-Q-TOF-MS helped us to support this identification. The extraction steps and the LC-MS/MS conditions developed to analyse muscle tissue samples are described. This clarification concerning the rigorous identification of chromatographic peaks allowed us to evaluate the relevance of our monitoring method with regard to the regulations in place in the European Union and could be of help to laboratories involved in official control of antibiotic residues in food of animal origin. Additional results are also presented highlighting the transformation of the CTC when prepared in a mixture with other antibiotics.
Exploratory Factor Analysis of SCL90-R Symptoms Relevant to Psychosis
Javad Amini
2011-10-01
Full Text Available "nObjective: Inconsistent results have been reported regarding the symptom dimensions relevant to psychosis in symptoms check list revised (SCL90-R, i.e., "psychoticism" and "paranoid ideation". Therefore, some studies have suggested different factor structures for questions of these two dimensions, and proposed two newly defined dimensions of "schizotypal signs" and "schizophrenia nuclear symptoms". We conducted an exploratory factor analysis on the items of these two dimensions in a general population sample in Iran. "nMethod: A total of 2158 subjects residing in Southern Tehran (capital of Iran were interviewed using the psychoticism and paranoid ideation questions in SCL90-R to assess severity of these symptom dimensions. Factor analysis was done through SAS 9.1.3 PROC FACTOR using Promax rotation (power=3 on the matrix of "polychoric correlations among variables" as the input data. "nResults: Two factors were retained by the proportion criterion. Considering loadings >= 0.5 as minimum criteria for factor loadings, 7 out of 10 questions from psychoticism ,and 3 out of 6 questions from paranoid ideation were retained, and others were eliminated. The factor labels proposed by the questionnaire suited the extracted factors and were retained. Internal consistency for each of the dimensions was acceptable (Cronbach's alpha 0.7 and 0.74 for paranoid ideation and psychoticism respectively. Composite scores showed a half-normal distribution for both dimensions which is predictable for instruments that detect psychotic symptoms. "nConclusion: Results were in contrast with similar studies, and questioned them by suggesting a different factor structure obtained from a statistically large population. The population in a developing nation (Iran in this study and the socio-cultural differences in developed settings are the potential sources for discrepancies between this analysis and previous reports.
Upper GI endoscopy in elderly patients: predictive factors of relevant endoscopic findings.
Buri, Luigi; Zullo, Angelo; Hassan, Cesare; Bersani, Gianluca; Anti, Marcello; Bianco, Maria A; Cipolletta, Livio; Giulio, Emilio Di; Matteo, Giovanni Di; Familiari, Luigi; Ficano, Leonardo; Loriga, Piero; Morini, Sergio; Pietropaolo, Vincenzo; Zambelli, Alessandro; Grossi, Enzo; Tessari, Francesco; Intraligi, Marco; Buscema, Massimo
2013-03-01
Elderly patients are at increased risk for peptic ulcer and cancer. Predictive factors of relevant endoscopic findings at upper endoscopy in the elderly are unknown. This was a post hoc analysis of a nationwide, endoscopic study. A total of 3,147 elderly patients were selected. Demographic, clinical, and endoscopic data were systematically collected. Relevant findings and new diagnoses of peptic ulcer and malignancy were computed. Both univariate and multivariate analyses were performed. A total of 1,559 (49.5%), 213 (6.8%), 93 (3%) relevant findings, peptic ulcers, and malignancies were detected. Peptic ulcers and malignancies were more frequent in >85-year-old patients (OR 3.1, 95% CI = 2.0-4.7, p = 0.001). The presence of dysphagia (OR = 5.15), weight loss (OR = 4.77), persistent vomiting (OR = 3.68), anaemia (OR = 1.83), and male gender (OR = 1.9) were significantly associated with a malignancy, whilst overt bleeding (OR = 6.66), NSAIDs use (OR = 2.23), and epigastric pain (OR = 1.90) were associated with the presence of peptic ulcer. Peptic ulcer or malignancies were detected in 10% of elderly patients, supporting the use of endoscopy in this age group. Very elderly patients appear to be at higher risk of such lesions.
Pion Form Factor in QCD at Intermediate Momentum Transfers
Braun, V M; Maul, M
1999-01-01
We present a quantitative analysis of the electromagnetic pion form factor in the light-cone sum rule approach, including radiative corrections and higher-twist effects. The comparison to the existing data favors the asymptotic profile of the pion distribution amplitude and allows to estimate the deviation: $(\\int du/u \\phi_\\pi(u))/ (\\int du/u \\phi^{\\rm as}_\\pi(u))=$ 1.1$\\pm$ 0.1 at the scale 1 GeV. Special attention is payed to the precise definition and interplay of soft and hard contributions at intermediate momentum transfer, and to matching of the sum rule to the perturbative QCD prediction. We observe a strong numerical cancellation between the soft (end point) contribution and power suppressed hard contributions of higher twist, so that the total nonperturbative correction to the usual pQCD result turns out to be of order 30% for $Q^2\\sim 1$ GeV$^2$.
Study of the phi-pi0 transition form factor
Pacetti, Simone
2009-01-01
Recently the BaBar Collaboration published new data on the cross section for the annihilation e+e- -> phi pi0, obtained using the initial state radiation technique at a center of mass energy of 10.6 GeV. Such a process represents an interesting test bed for the quark model. Indeed, since the phi-pi0 production via e+e- annihilation proceeds through a mechanism which violates the Okubo-Zweig-Iizuka rule, the corresponding cross section could be characterized by contributions from non-qqbar bound states, like hybrids or tetraquarks. The phi-pi0 cross section is analyzed in connection with other data coming from different processes, that involve the same mesons, using a method which implements the analyticity in the phi-pi0 transition form factor by means of a dispersion relation procedure.
Geometrical form factor calculation using Monte Carlo integration for lidar
Mao, Feiyue; Gong, Wei; Li, Jun
2012-06-01
We proposed a geometrical form factor (GFF) calculation using Monte Carlo integration (GFF-MC) for lidar that is practical and can be applied to any laser intensity distribution. Theoretical results have been calculated with our method based on the functions of measured, uniform and Gaussian laser intensity distribution. Two experimental GFF traces on clear days are obtained to verify the validity of the theoretical results. The results indicated that the measured distribution function outperformed the Gaussian and uniform functions. That means that the deviation of the measured laser intensity distribution from an ideal one can be too large to neglect. In addition, the theoretical GFF of the uniform distribution had a larger error than that of the Gaussian distribution. Furthermore, the effects of the inclination angle of the laser beam and the central obstruction of the support structure of the second mirror of the telescope are discussed in this study.
Thin and small form factor cells : simulated behavior.
Clews, Peggy Jane; Pluym, Tammy; Grubbs, Robert K.; Cruz-Campa, Jose Luis; Zubia, David (University of Texas at El Paso, El Paso, TX); Young, Ralph Watson; Okandan, Murat; Gupta, Vipin P.; Nielson, Gregory N.; Resnick, Paul James
2010-07-01
Thin and small form factor cells have been researched lately by several research groups around the world due to possible lower assembly costs and reduced material consumption with higher efficiencies. Given the popularity of these devices, it is important to have detailed information about the behavior of these devices. Simulation of fabrication processes and device performance reveals some of the advantages and behavior of solar cells that are thin and small. Three main effects were studied: the effect of surface recombination on the optimum thickness, efficiency, and current density, the effect of contact distance on the efficiency for thin cells, and lastly the effect of surface recombination on the grams per Watt-peak. Results show that high efficiency can be obtained in thin devices if they are well-passivated and the distance between contacts is short. Furthermore, the ratio of grams per Watt-peak is greatly reduced as the device is thinned.
Meson Form Factors and Deep Exclusive Meson Production Experiments
Horn, Tanja [The Catholic Univ. of America, Washington, DC (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2017-05-01
Pion and kaon electroproduction data play a unique role in Nature and our understanding of them is essential for explaining hadron structure. Precision longitudinaltransverse separated pion and kaon cross sections are of particular interest. They allow for the extraction of meson form factors and validation of understanding of hard exclusive and semi-inclusive reactions (π+, K+, π0, γ) towards 3D hadron imaging and potential future flavor decomposition. We review recent data and present prospects for deep exclusive pion and kaon electroproduction at the 12 GeV Jefferson Lab including the prospects to use projected charged- and neutral pion data to further determine the spin, charge-parity and flavor of GPDs, including the helicity-flip GPDs.
The neutral pion form factor at NA62
Cenci, Patrizia
2016-11-01
In 2007 the NA62 experiment at CERN collected a large sample of charged kaon decays with a highly efficient trigger selecting events with electrons in the final state. The kaon beam represents a rich source of tagged neutral pion decays in vacuum. The electromagnetic transition form factor slope of the π0 in the time-like region has been measured from about 106 fully reconstructed π0 Dalitz decays collected in 2007. The preliminary result a = (3.68 ± 0.51stat ± 0.25syst) × 10-2 is the most precise to date. This value is compatible with theoretical expectations and consistent with the previous measurements.
K -> pi l nu form factors with staggered quarks
Gamiz, E; El-Khadra, A X; Kronfeld, A S; Mackenzie, P B; Simone, J
2011-01-01
We report on the status of the Fermilab-MILC calculation of the form factor f_+^{K pi}(0), needed to extract the CKM matrix element |V_{us}| from experimental data on K semileptonic decays. The HISQ formulation is used in the simulations for the valence quarks, while the sea quarks are simulated with the asqtad action (MILC N_f=2+1 configurations). We discuss the general methodology of the calculation, including the use of twisted boundary conditions to get values of the momentum transfer close to zero and the different techniques applied for the correlators fits. We present initial results for lattice spacings a=0.12fm and a=0.09fm, and several choices of the light quark masses.
Form factors and related quantities in clothed-particle representation
Shebeko Alexander
2017-01-01
Full Text Available We show new applications of the notion of clothed particles in quantum field theory. Its realization by means of the clothing procedure put forward by Greenberg and Schweber allows one to express the total Hamiltonian H and other generators of the Poincaré group for a given system of interacting fields through the creation (annihilation operators for the so-called clothed particles with physical (observed properties. Here such a clothed particle representation is used to calculate the matrix elements (shortly, form factors of the corresponding Nöther current operators sandwiched between the H eigenstates. Our calculations are performed with help of an iterative technique suggested by us earlier when constructing the NN → πNN transition operators. As an illustration, we outline some application of our approach in the spinor quantum electrodynamics.
Current correlators and form factors in the resonance region
Rosell, I. [Departamento de Ciencias Fisicas, Matematicas y de la Computacion, Universidad CEU Cardenal Herrera, c/Sant Bartomeu 55, E-46115 Alfara del Patriarca, Valencia (Spain); IFIC, Universitat de Valencia - CSIC, Apt. Correus 22085, E-46071 Valencia (Spain)
2009-01-15
Within Resonance Chiral Theory and in the context of QCD current correlators at next-to-leading order in 1/N{sub C}, we have analyzed the two-body form factors which include resonances as a final state. The short-distance constraints have been studied. One of the main motivations is the estimation of the chiral low-energy constants at subleading order, that is, keeping full control of the renormalization scale dependence. As an application we show the resonance estimation of some coupling, L{sub 10}{sup r}({mu}{sub 0})=(-4.4{+-}0.9).10{sup -3} and C{sub 87}{sup r}({mu}{sub 0})=(3.1{+-}1.1).10{sup -5}.
Exposing strangeness: Projections for kaon electromagnetic form factors
Gao, Fei; Chang, Lei; Liu, Yu-Xin; Roberts, Craig D.; Tandy, Peter C.
2017-08-01
A continuum approach to the kaon and pion bound-state problems is used to reveal their electromagnetic structure. For both systems, when used with parton distribution amplitudes appropriate to the scale of the experiment, Standard Model hard-scattering formulas are accurate to within 25% at momentum transfers Q2≈8 GeV2. There are measurable differences between the distribution of strange and normal matter within the kaons, e.g. the ratio of their separate contributions reaches a peak value of 1.5 at Q2≈6 GeV2. Its subsequent Q2 evolution is accurately described by the hard scattering formulas. Projections for the ratio of kaon and pion form factors at timelike momenta beyond the resonance region are also presented. These results and projections should prove useful in planning next-generation experiments.
Lattice calculation of composite dark matter form factors
Appelquist, T; Buchoff, M I; Cheng, M; Cohen, S D; Fleming, G T; Kiskis, J; Lin, M F; Neil, E T; Osborn, J C; Rebbi, C; Schaich, D; Schroeder, C; Syritsyn, S N; Voronov, G; Vranas, P; Wasem, J
2013-01-01
Composite dark matter candidates, which can arise from new strongly-coupled sectors, are well-motivated and phenomenologically interesting, particularly in the context of asymmetric generation of the relic density. In this work, we employ lattice calculations to study the electromagnetic form factors of electroweak-neutral dark-matter baryons for a three-color, QCD-like theory with Nf = 2 and 6 degenerate fermions in the fundamental representation. We calculate the (connected) charge radius and anomalous magnetic moment, both of which can play a significant role for direct detection of composite dark matter. We find minimal Nf dependence in these quantities. We generate mass-dependent cross-sections for dark matter-nucleon interactions and use them in conjunction with experimental results from XENON100, excluding dark matter candidates of this type with masses below 10 TeV.
Form factors and related quantities in clothed-particle representation
Shebeko, Alexander; Arslanaliev, Adam
2017-03-01
We show new applications of the notion of clothed particles in quantum field theory. Its realization by means of the clothing procedure put forward by Greenberg and Schweber allows one to express the total Hamiltonian H and other generators of the Poincaré group for a given system of interacting fields through the creation (annihilation) operators for the so-called clothed particles with physical (observed) properties. Here such a clothed particle representation is used to calculate the matrix elements (shortly, form factors) of the corresponding Nöther current operators sandwiched between the H eigenstates. Our calculations are performed with help of an iterative technique suggested by us earlier when constructing the NN → πNN transition operators. As an illustration, we outline some application of our approach in the spinor quantum electrodynamics.
Measurement of Baryon Electromagnetic Form Factors at BESIII
Morales, Cristina Morales
2016-01-01
The Beijing $e^+e^-$-collider (BEPCII) is a double-ring symmetric collider running at center-of-mass energies between 2.0 and 4.6 GeV. This energy range allows the BESIII-experiment to measure baryon electromagnetic form factors in direct $e^+e^-$-annihilation and in initial state radiation processes. In this paper, results on $e^+e^-\\rightarrow p\\bar{p}$ and $e^+e^-\\rightarrow \\Lambda \\bar{\\Lambda}$ based on data collected by BESIII in 2011 and 2012 are presented. Expectations from the BESIII high luminosity energy scan from 2015 and from radiative return at different center-of-mass energies are also reported.
Conformal anomaly of generalized form factors and finite loop integrals
Chicherin, Dmitry
2017-01-01
We reveal a new mechanism of conformal symmetry breaking at Born level. It occurs in generalized form factors with several local operators and an on-shell state of massless particles. The effect is due to hidden singularities on collinear configurations of the momenta. This conformal anomaly is different from the holomorphic anomaly of amplitudes. We present a number of examples in four and six dimensions. We find an application of the new conformal anomaly to finite loop momentum integrals with one or more massless legs. The collinear region around a massless leg creates a contact anomaly, made visible by the loop integration. The anomalous conformal Ward identity for an $\\ell-$loop integral is a 2nd-order differential equation whose right-hand side is an $(\\ell-1)-$loop integral. We show several examples, in particular the four-dimensional scalar double box.
Form Factor $g$ In Longitudinal Space Charge Impedance
Baartman, R
2015-01-01
In carrying out calculations of the effect of longitudinal space charge on longitudinal motion, the transverse beam size appears in a form factor which is usually written as $g=1+2\\ln (b/a)$. In fact, this expression applies to particles with vanishing betatron amplitude in a beam with uniform transverse distribution. It is argued that an average over the transverse distribution should be used instead of the value on axis. It is shown that for the realistic `binomial' family of distributions the 1 in the above expression for $g$ should be replaced by a value near 0.5 if $a$ is interpreted as twice the rms width of the beam.
Algebraic approach to form factors in the complex sinh-Gordon theory
Lashkevich, Michael
2016-01-01
We study form factors of the quantum complex sinh-Gordon theory in the algebraic approach. In the case of exponential fields the form factors can be obtained from the known form factors of the $Z_N$-symmetric Ising model. The algebraic construction also provides an Ansatz for form factors of descendant operators. We obtain generating functions of such form factors and establish their main properties: the cluster factorization and reflection equations.
Algebraic approach to form factors in the complex sinh-Gordon theory
Lashkevich, Michael; Pugai, Yaroslav
2017-01-01
We study form factors of the quantum complex sinh-Gordon theory in the algebraic approach. In the case of exponential fields the form factors can be obtained from the known form factors of the ZN-symmetric Ising model. The algebraic construction also provides an Ansatz for form factors of descendant operators. We obtain generating functions of such form factors and establish their main properties: the cluster factorization and reflection equations.
THE USE OF RELEVANT FACTORS FOR CONSUMERS IN DESIGNING A COMMUNICATIONAL MESSAGE
Olimpia OANCEA
2014-06-01
Full Text Available Today, organizations must adapt to the new realities of the environment in which they operate, and their efforts must be increasingly more oriented towards identifying the factors that influence consumer behavior, in particular economic, social and psychological aspects. When consumers are acting on incomplete information base, they assume automatically a risk for each purchasing decision. The size of the risk decreases depending on the quantity and relevance of information transmitted through communicational messages. Therefore, the aim of this paper is to highlight the factors that should be taken into account when designing a communicational message, so that this has to have the ability to change consumer attitudes and to keep constant interest to the products and / or services of a company.
Pediculosis capitis and relevant factors in secondary school students of Hamadan, west of Iran.
Omidi, Afsar; Khodaveisi, Masoud; Moghimbeigi, Abas; Mohammadi, Nahid; Amini, Roya
2013-09-17
Pediculosis capitis is a problem in children and has worldwide distribution. The aim of the present study was to determine the prevalence of pediculosis degree and its relevant factors in the secondary schools in Hamadan west of Iran. The study was carried out in two phases. A cross-sectional procedure was used to determine the prevalence of pediculosis, and the case study was done to identify the relevant factors to the infestation. Totally, 10841 secondary students were chosen and classified in accordance with the clustering sample. The prevalence of pediculosis was 1.05%. It was 1.27% among the urban student; whereas 0.05% among the rural students. About 2.3% belonged to female students, and 0.11% was pertained to the male students. The greatest amount of infestation prevalence was reported from the schools of urban areas particularly in the public schools of suburbia. Furthermore, the prevalence of infestation was more where some individuals had pediculosis previous history and suffered from head inching. It turned out to be a significant relationship between pediculosis, head itching (Ppediculosis (Ppediculosis in Hamadan is low, but is more in the areas which are deprived of the access to health facilities. Therefore, there is a need for educational campaigns about danger of infection and regular mass screening at school.
Ault, Kelvin; Childs, Brad; Wainright, Charles F; Young, Marilyn
2011-01-01
The purpose of this article is to explore the factors that affect the negotiations for an acquisition of a nonprofit system by an investor-owned entity. The recent economic downturn, accompanying credit crisis, and healthcare reform legislation will likely encourage and accelerate the pace of merger and acquisition (M&A) transactions between investor-owned entities and nonprofit hospitals. As many nonprofits are smaller, more financially vulnerable, and more limited in their access to capital than their investor-owned counterparts, nonprofits could be prime targets for investor-owned acquirers during the healthcare reform implementation period. In M&A transactions of this type, the investor-owned acquirer typically is motivated to pursue an acquisition when the deal promises an acceptable return on investment and decreased operating costs from economies of scale. Alternatively, the nonprofit target is typically seeking funding for upgrades to facilities and information technology systems as well as a continued commitment to charity care and managed-care contracting leverage. A successful acquisition of a nonprofit hospital by an investor-owned company requires a careful analysis of relevant tax, economic, and strategic factors prior to closing the deal. This article lists the most significant factors to consider in these deals and explains how these factors should influence the purchase price and postacquisition cash flow.
Junichi Hasegawa
Full Text Available The aim of this study was to identify the relevant obstetric factors for cerebral palsy (CP after 33 weeks' gestation in Japan.This retrospective case cohort study (1:100 cases and controls used a Japanese national CP registry. Obstetric characteristics and clinical course were compared between CP cases in the Japan Obstetric Compensation System for Cerebral Palsy database and controls in the perinatal database of the Japan Society of Obstetrics and Gynecology born as live singleton infants between 2009 and 2011 with a birth weight ≥ 2,000 g and gestation ≥ 33 weeks.One hundred and seventy-five CP cases and 17,475 controls were assessed. Major relevant single factors for CP were placental abnormalities (31%, umbilical cord abnormalities (15%, maternal complications (10%, and neonatal complications (1%. A multivariate regression model demonstrated that obstetric variables associated with CP were acute delivery due to non-reassuring fetal status (relative risk [RR]: 37.182, 95% confidence interval [CI]: 20.028-69.032, uterine rupture (RR: 24.770, 95% CI: 6.006-102.160, placental abruption (RR: 20.891, 95% CI: 11.817-36.934, and preterm labor (RR: 3.153, 95% CI: 2.024-4.911, whereas protective factors were head presentation (RR: 0.199, 95% CI: 0.088-0.450 and elective cesarean section (RR: 0.236, 95% CI: 0.067-0.828.CP after 33 weeks' gestation in the recently reported cases in Japan was strongly associated with acute delivery due to non-reassuring fetal status, uterine rupture, and placental abruption.
Therapy-relevant factors in adult ADHD from a cognitive behavioural perspective.
Newark, Patricia Elizabeth; Stieglitz, Rolf-Dieter
2010-06-01
Adult individuals with attention-deficit hyperactivity disorder (ADHD) have been suffering from this neurobiological and highly heritable disorder chronically since childhood. Resulting from their longstanding neuropsychological impairments, such as attentional problems, emotional instability, and disinhibition, they are familiar to a multiplicity of negative life outcomes and underachievement. Furthermore, a large part of this population suffers from psychiatric comorbidity. This accumulation of negative experiences has an impact on therapy-relevant factors such as the individual's self-esteem, self-efficacy, development of core beliefs/schemas, and coping strategies. Based on negative beliefs about the self, individuals confronted with difficult situations develop maladaptive coping strategies, for instance avoidance and procrastination. These strategies lead to maintenance and reinforcement of maladaptive beliefs, and as such they acquit themselves as schema-confirming. Captured in this vicious cycle, the individual sees her negative view of the self confirmed. The purpose of this paper is to illuminate these interactive factors that influence the aforementioned cycle in order to emphasize the cognitive behavioural interventions tailored to those factors on the basis of latest research. Furthermore, the authors want to attract notice to the resources people with ADHD are said to have, namely creativity and resilience. These postulated resources could be therapy-relevant by creating positive beliefs about the self, hence improving coping skills and breaking the vicious circle of negative appraisal. Taking into account personal resources and their fostering may be an important fundament for the treatment plan of adult ADHD. Information on the current state of research and theoretical approaches concerning the below-mentioned key words was gathered through MEDLINE, PsycINFO, PSYNDEXplus, and PubMed databases.
Hasegawa, Junichi; Toyokawa, Satoshi; Ikenoue, Tsuyomu; Asano, Yuri; Satoh, Shoji; Ikeda, Tomoaki; Ichizuka, Kiyotake; Tamiya, Nanako; Nakai, Akihito; Fujimori, Keiya; Maeda, Tsugio; Masuzaki, Hideaki; Suzuki, Hideaki; Ueda, Shigeru
2016-01-01
Objective The aim of this study was to identify the relevant obstetric factors for cerebral palsy (CP) after 33 weeks’ gestation in Japan. Study design This retrospective case cohort study (1:100 cases and controls) used a Japanese national CP registry. Obstetric characteristics and clinical course were compared between CP cases in the Japan Obstetric Compensation System for Cerebral Palsy database and controls in the perinatal database of the Japan Society of Obstetrics and Gynecology born as live singleton infants between 2009 and 2011 with a birth weight ≥ 2,000 g and gestation ≥ 33 weeks. Results One hundred and seventy-five CP cases and 17,475 controls were assessed. Major relevant single factors for CP were placental abnormalities (31%), umbilical cord abnormalities (15%), maternal complications (10%), and neonatal complications (1%). A multivariate regression model demonstrated that obstetric variables associated with CP were acute delivery due to non-reassuring fetal status (relative risk [RR]: 37.182, 95% confidence interval [CI]: 20.028–69.032), uterine rupture (RR: 24.770, 95% CI: 6.006–102.160), placental abruption (RR: 20.891, 95% CI: 11.817–36.934), and preterm labor (RR: 3.153, 95% CI: 2.024–4.911), whereas protective factors were head presentation (RR: 0.199, 95% CI: 0.088–0.450) and elective cesarean section (RR: 0.236, 95% CI: 0.067–0.828). Conclusion CP after 33 weeks’ gestation in the recently reported cases in Japan was strongly associated with acute delivery due to non-reassuring fetal status, uterine rupture, and placental abruption. PMID:26821386
Light meson electromagnetic form factors from three-flavor lattice QCD with exact chiral symmetry
Aoki, S; Feng, X; Hashimoto, S; Kaneko, T; Noaki, J; Onogi, T
2015-01-01
We study the chiral behavior of the electromagnetic (EM) form factors of pion and kaon in three-flavor lattice QCD. In order to make a direct comparison of the lattice data with chiral perturbation theory (ChPT), we employ the overlap quark action that has exact chiral symmetry. Gauge ensembles are generated at a lattice spacing of 0.11 fm with four pion masses ranging between M_pi \\simeq 290 MeV and 540 MeV and with a strange quark mass m_s close to its physical value. We utilize the all-to-all quark propagator technique to calculate the EM form factors with high precision. Their dependence on m_s and on the momentum transfer is studied by using the reweighting technique and the twisted boundary conditions for the quark fields, respectively. A detailed comparison with SU(2) and SU(3) ChPT reveals that the next-to-next-to-leading order terms in the chiral expansion are important to describe the chiral behavior of the form factors in the pion mass range studied in this work. We estimate the relevant low-energy...
Light meson electromagnetic form factors from three-flavor lattice QCD with exact chiral symmetry
Aoki, S.; Cossu, G.; Feng, X.; Hashimoto, S.; Kaneko, T.; Noaki, J.; Onogi, T.
2016-02-01
We study the chiral behavior of the electromagnetic (EM) form factors of pions and kaons in three-flavor lattice QCD. In order to make a direct comparison of the lattice data with chiral perturbation theory (ChPT), we employ the overlap quark action that has exact chiral symmetry. Gauge ensembles are generated at a lattice spacing of 0.11 fm with four pion masses ranging between Mπ≃290 MeV and 540 MeV and with a strange quark mass ms close to its physical value. We utilize the all-to-all quark propagator technique to calculate the EM form factors with high precision. Their dependence on ms and on the momentum transfer is studied by using the reweighting technique and the twisted boundary conditions for the quark fields, respectively. A detailed comparison with SU(2) and SU(3) ChPT reveals that the next-to-next-to-leading order terms in the chiral expansion are important to describe the chiral behavior of the form factors in the pion mass range studied in this work. We estimate the relevant low-energy constants and the charge radii, and find reasonable agreement with phenomenological and experimental results.
Analysis of the Relevant Factors for the Engaging Women in Various Sports in Croatia
Joško Sindik
2016-03-01
Full Text Available Goals of this research were to determine the correlations among the dimensions of relevant factors about engagement of women in sports, as well as to determine the differences in the dimensions of relevant factors about engagement of women in sports, according to several independent variables: type of sport, educational level, marital status and place of living. A total of 342 female athletes and other sport practitioners are examined, with the average age of 31.53±13.92 years (M±SD from several Croatian sport federations: judo, badminton, gymnastics, bowling, acrobatic rock’n roll, handball, sport fishing, Association of the deaf athletes, archery, chess and basketball. The results revealed that according to the type of sport, the differences are statistically significant for: negative environment, relaxation/fun and ambition/self-esteem motives; environmental, obligation and financial/traffic/rules barriers; indirect strategies and already present initiatives for including women in sports. According to the education level, the differences are statistically significant for: positive personal, negative environmental motives and ambition/self-esteem motives; obligations as the barriers; organization out-of-sport commitments and specific strategies for media. The differences in the marital status of participants are statistically significant for the variables: positive personal, negative environmental and ambition/self-esteem motives; environmental and obligation barriers; organization of out-of-sport commitments. At last, only two statistically significant differences are found according to the place of living: for indirect strategies for including women in sports and for the programs created only for women. The results provide the platform for developing programs and strategies for retaining and engaging women in particular sports in Croatia.
Nucleon Structure and Hyperon Form Factors from Lattice QCD.
Lin,H.W.
2007-06-11
In this work, I report the latest lattice QCD calculations of nucleon and hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All calculations are done with a chirally symmetric fermion action, domain-wall fermions, for valence quarks. I begin with the latest lattice results on the nucleon structure, focusing on results from RBC/UKQCD using 2+1-flavor chiral fermion actions. We find the chiral-extrapolated axial coupling constant at physical pion mass point. to be 1.23(5), consistent with experimental value. The renormalization constants for the structure functions are obtained from RI/MOM-scheme non-perturbative renormalization. We find first moments of the polarized and unpolarized nucleon structure functions at zero transfer momentum to be 0.133(13) and 0.203(23) respectively, using continuum chiral extrapolation. These are consistent with the experimental values, unlike previous calculations which have been 50% larger. We also have a prediction for the transversity, which we find to be 0.56(4). The twist-3 matrix element is consistent with zero which agrees with the prediction of the Wandzura-Wilczek relation. In the second half of this work, I report an indirect dynamical estimation of the strangeness proton magnetic moments using mixed actions. With the analysis of hyperon form factors and using charge symmetry, the strangeness of proton is found to be -0.066(2G), consistent with the Adelaide-JLab Collaboration's result. The hyperon {Sigma} and {Xi} axial coupling constants are also performed for the first time in a lattice calculation, g{sub {Sigma}{Sigma}} = 0.441(14) and g{sub {Xi}{Xi}} = -0.277(11).
Nucleon Structure and hyperon form factors from lattice QCD
Lin, Huey-Wen
2007-06-11
In this work, I report the latest lattice QCD calculations of nucleon and hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All calculations are done with a chirally symmetric fermion action, domain-wall fermions, for valence quarks. I begin with the latest lattice results on the nucleon structure, focusing on results from RBC/UKQCD using 2+1-flavor chiral fermion actions. We find the chiral-extrapolated axial coupling constant at physical pion mass point to be 1.23(5), consistant with experimental value. The renormalization constants for the structure functions are obtained from RI/MOM-scheme non-perturbative renormalization. We find first moments of the polarized and unpolarized nucleon structure functions at zero transfer momentum to be 0.133(13) and 0.203(23) respectively, using continuum chiral extrapolation. These are consistent with the experimental values, unlike previous calculations which have been 50% larger. We also have a prediction for the transversity, which we find to be 0.56(4). The twist-3 matrix element is consistent with zero which agrees with the prediction of the Wandzura-Wilczek relation. In the second half of this work, I report an indirect dynamical estimation of the strangeness proton magnetic moments using mixed actions. With the analysis of hyperon form factors and using charge symmetry, the strangeness of proton is found to be -0.066(26), consistent with the Adelaide-JLab Collaboration's result. The hyperon Sigma and Xi axial coupling constants are also performed for the first time in a lattice calculation, g_SigmaSigma = 0.441(14) and g_XiXi = -0.277(11).
Shen, Shen; Sun, Qianmei
2015-01-01
Background Pulmonary hypertension (PH) is common in patients with maintenance hemodialysis (MHD) and is associated with high mortality. This study analyzed clinically relevant factors for pulmonary hypertension in MHD patients and the effect of serum pentraxin3 (PTX3) in the pathogenesis of PH to provide the basis for early diagnosis and treatment of MHD patients with PH. Material/Methods This study included 60 MHD patients (group A) and 30 healthy controls (group B). Group A was further divided into PH and non-PH groups. Clinical characteristics, auxiliary examination results and serum PTX3 level of the PH and non-PH groups were compared. Binary logistic regression was used to assess the risk factors for PH in MHD patients. ROC curve was applied to evaluate the diagnostic value of PTX3 in PH. Results The incidence rate of PH in MHD patients was 50%, and most presented as mild to moderate. Compared with the non-PH group, patients in PH group presented significantly longer atrial diameter, right ventricular diameter and main pulmonary artery diameter (PMHD patients. AUC of PTX3 was 0.721 (95%CI: 0.590–0.851, P=0.003). Conclusions The prevalence of PH was higher in MHD patients and mostly presented as mild to moderate. Such patients often developed heart structural changes and cardiac ultrasound was highly recommended. Serum PTX3 level was significantly elevated and could be used as a marker of PH in MHD patients. PMID:26706606
Relationships Among Factors Relevant to Abdominal Fat and Age-Related Hearing Loss.
Lee, Young; Park, Mina
2017-05-11
Metabolic syndrome is related with abdominal fat and with age-related hearing loss (ARHL). In this study, we evaluated the association between a variety of factors relevant to abdominal fat (FRAs) and hearing thresholds. We reviewed retrospectively the medical records of 2,602 subjects aged over 40 years with symmetrical sensorineural hearing loss who underwent abdominal fat computed tomography (CT) scans. Univariate and multivariate linear regression analyses were used to demonstrate the association between each FRA and hearing thresholds at low and high frequencies. Four of 5 FRAs were associated with hearing thresholds at high frequencies in males. All FRAs examined showed a relationship with hearing thresholds at low frequencies in females. Diabetes mellitus (DM) among clinical factors and visceral adipose tissue (VAT) among the 5 FRAs were the most reflective of hearing thresholds in both males and females. We found that FRAs were associated with hearing loss with frequency specific characteristics according to sex and reinforced that DM and VAT is particularly an important role for hearing.
How pharmacist-patient communication determines pharmacy loyalty? Modeling relevant factors.
Patrícia Antunes, Liliana; Gomes, João José; Cavaco, Afonso Miguel
2015-01-01
Portuguese community pharmacies provide pharmaceutical services, such as therapeutic outcomes follow-up, supplemented by relevant point-of-care testing that require continuity of provision to be effective. To identify factors of technical and communication nature that during a patient interview contribute to patients' loyalty. A cross-sectional descriptive study, with a purposive sample of community pharmacies providing pharmaceutical care, was conducted. Patient interviews were taped and transcribed verbatim. Duration, segments and utterances were identified and time stamped, using a previously validated coding scheme. To identify predictors of loyalty, logistic regression analyses were performed. From 59 interviews, participants' average age was 65.7 years and 42 (71.2%) were female; 45 (76.3%) interviews were classified as outcomes measurements and 14 (23.7%) as pharmaceutical consultations, with 33.2% of the patients booking a following appointment. The significant items to explain loyalty were associated with lifestyle and psychosocial exchange, age of the patient, and the presence of all interview segments (i.e. a complete consultation). Contrary to common professional beliefs and practice orientation it would appear that pharmacists' technical skills are not the essential factors that promote patients' loyalty needed for continuity of care, at least in the same extent as the social and lifestyle-related content of the exchange. Pharmaceutical care education should focus on relational skills as much as on medication-related competencies. Copyright © 2015 Elsevier Inc. All rights reserved.
Expression, regulation and clinical relevance of the ATPase inhibitory factor 1 in human cancers
Sánchez-Aragó, M; Formentini, L; Martínez-Reyes, I; García-Bermudez, J; Santacatterina, F; Sánchez-Cenizo, L; Willers, I M; Aldea, M; Nájera, L; Juarránz, Á; López, E C; Clofent, J; Navarro, C; Espinosa, E; Cuezva, J M
2013-01-01
Recent findings in colon cancer cells indicate that inhibition of the mitochondrial H+-adenosine triphosphate (ATP) synthase by the ATPase inhibitory factor 1 (IF1) promotes aerobic glycolysis and a reactive oxygen species (ROS)-mediated signal that enhances proliferation and cell survival. Herein, we have studied the expression, biological relevance, mechanism of regulation and potential clinical impact of IF1 in some prevalent human carcinomas. We show that IF1 is highly overexpressed in most (>90%) of the colon (n=64), lung (n=30), breast (n=129) and ovarian (n=10) carcinomas studied as assessed by different approaches in independent cohorts of cancer patients. The expression of IF1 in the corresponding normal tissues is negligible. By contrast, the endometrium, stomach and kidney show high expression of IF1 in the normal tissue revealing subtle differences by carcinogenesis. The overexpression of IF1 also promotes the activation of aerobic glycolysis and a concurrent ROS signal in mitochondria of the lung, breast and ovarian cancer cells mimicking the activity of oligomycin. IF1-mediated ROS signaling activates cell-type specific adaptive responses aimed at preventing death in these cell lines. Remarkably, regulation of IF1 expression in the colon, lung, breast and ovarian carcinomas is exerted at post-transcriptional levels. We demonstrate that IF1 is a short-lived protein (t1/2 ∼100 min) strongly implicating translation and/or protein stabilization as main drivers of metabolic reprogramming and cell survival in these human cancers. Analysis of tumor expression of IF1 in cohorts of breast and colon cancer patients revealed its relevance as a predictive marker for clinical outcome, emphasizing the high potential of IF1 as therapeutic target. PMID:23608753
Jin Hyoung Cho
2016-11-01
Full Text Available Meat quality is a complex trait influenced by many factors, including genetics, nutrition, feeding environment, animal handling, and their interactions. To elucidate relevant factors affecting pork quality associated with oxidative stress and muscle development, we analyzed protein expression in high quality longissimus dorsi muscles (HQLD and low quality longissimus dorsi muscles (LQLD from Duroc pigs by liquid chromatographytandem mass spectrometry (LC-MS/MS–based proteomic analysis. Between HQLD (n = 20 and LQLD (n = 20 Duroc pigs, 24 differentially expressed proteins were identified by LC-MS/MS. A total of 10 and 14 proteins were highly expressed in HQLD and LQLD, respectively. The 24 proteins have putative functions in the following seven categories: catalytic activity (31%, ATPase activity (19%, oxidoreductase activity (13%, cytoskeletal protein binding (13%, actin binding (12%, calcium ion binding (6%, and structural constituent of muscle (6%. Silver-stained image analysis revealed significant differential expression of lactate dehydrogenase A (LDHA between HQLD and LQLD Duroc pigs. LDHA was subjected to in vitro study of myogenesis under oxidative stress conditions and LDH activity assay to verification its role in oxidative stress. No significant difference of mRNA expression level of LDHA was found between normal and oxidative stress condition. However, LDH activity was significantly higher under oxidative stress condition than at normal condition using in vitro model of myogenesis. The highly expressed LDHA was positively correlated with LQLD. Moreover, LDHA activity increased by oxidative stress was reduced by antioxidant resveratrol. This paper emphasizes the importance of differential expression patterns of proteins and their interaction for the development of meat quality traits. Our proteome data provides valuable information on important factors which might aid in the regulation of muscle development and the improvement of
Heiko Rüger
2012-01-01
In this regard, the present article aims at achieving three essential objectives. First, we will introduce a common indicator for circular job mobility patterns found in the two surveys. On the basis of this common indicator, we will comparatively analyse the prevalence of different mobility forms and their composition according to key socio-demographic characteristics. In addition, we will use multivariate analyses to illustrate the relevance of job mobility for partnership and family development. Results suggest mobility patterns to be an important individual context factor when explaining processes relevant to partnerships and family. In particular, women who exhibit some degree of job mobility are less often married and rarely have children.
Echeverria, Sandra E; Mustafa, Mehnaz; Pentakota, Sir Ram; Kim, Soyeon; Hastings, Katherine; Amadi, Chioma; Palaniappan, Latha
2017-02-17
Little evidence exists examining cardiovascular risk factors among Asian Americans and how social determinants such as nativity status and education pattern risk in the United States (U.S.) context. We used the 2011-2014 National Health and Nutrition Examination Survey, which purposely oversampled Asian Americans from 2011 to 2014, and examined prevalence of Type II diabetes, smoking and obesity for Asian Americans (n=1363) and non-Latino Whites (n=4121). We classified Asian Americans as U.S. or foreign-born and by years in the U.S. Obesity status was based on standard body mass index (BMI) cut points of ≥30kg/m(2) and Asian-specific cut points (BMI≥25kg/m(2)) that may be more clinically relevant for this population. We fit separate logistic regression models for each outcome using complex survey design methods and tested for the joint effect of race, nativity and education on each outcome.Diabetes and obesity prevalence (applying Asian-specific BMI cut points) were higher among Asian Americans when compared to non-Latino Whites but smoking prevalence was lower. These patterns remained in fully adjusted models and showed small increases with longer duration in the U.S. Joint effects models showed higher odds of prevalent Type II diabetes and obesity (Asian-specific) for foreign-born Asians, regardless of years in the U.S. and education, when compared to non-Latino Whites with high education. Smoking models showed significant interaction effects between race and education for non-Latino Whites only. Our study supports the premise that social as well as clinical factors should be considered when developing health initiatives for Asian Americans.
Local Quark-Hadron Duality and Magnetic Form Factors of Bound Proton
WANG Hong-Min; ZHANG Ben-Ai
2005-01-01
We discuss the consequence of local duality for elastic scattering, and derive a model-independent equation between structure functions at x ～ 1 and elastic electromagnetic form factors. Then the electromagnetic form factors of proton are discussed using the quark-hadron duality theory. We also debate the form factor of proton in a bound state.It may be an effective approach to study the form factor of proton in media.
FTO is a relevant factor for the development of the metabolic syndrome in mice.
Kathrin Ikels
Full Text Available The metabolic syndrome is a worldwide problem mainly caused by obesity. FTO was found to be a obesity-risk gene in humans and FTO deficiency in mice led to reduction in adipose tissue. Thus, FTO is an important factor for the development of obesity. Leptin-deficient mice are a well characterized model for analysing the metabolic syndrome. To determine the relevance of FTO for the development of the metabolic syndrome we analysed different parameters in combined homozygous deficient mice (Lep(ob/ob;Fto(-/-. Lep(ob/ob;Fto(-/- mice showed an improvement in analysed hallmarks of the metabolic syndrome in comparison to leptin-deficient mice wild type or heterozygous for Fto. Lep(ob/ob;Fto(-/- mice did not develop hyperglycaemia and showed an improved glucose tolerance. Furthermore, extension of beta-cell mass was prevented in Lep(ob/ob;Fto(-/-mice and accumulation of ectopic fat in the liver was reduced. In conclusion this study demonstrates that FTO deficiency has a protective effect not only on the development of obesity but also on the metabolic syndrome. Thus, FTO plays an important role in the development of metabolic disorders and is an interesting target for therapeutic agents.
The relevance of coagulation factor X protection of adenoviruses in human sera.
Duffy, M R; Doszpoly, A; Turner, G; Nicklin, S A; Baker, A H
2016-07-01
Intravenous delivery of adenoviruses is the optimal route for many gene therapy applications. Once in the blood, coagulation factor X (FX) binds to the adenovirus capsid and protects the virion from natural antibody and classical complement-mediated neutralisation in mice. However, to date, no studies have examined the relevance of this FX/viral immune protective mechanism in human samples. In this study, we assessed the effects of blocking FX on adenovirus type 5 (Ad5) activity in the presence of human serum. FX prevented human IgM binding directly to the virus. In individual human sera samples (n=25), approximately half of those screened inhibited adenovirus transduction only when the Ad5-FX interaction was blocked, demonstrating that FX protected the virus from neutralising components in a large proportion of human sera. In contrast, the remainder of sera tested had no inhibitory effects on Ad5 transduction and FX armament was not required for effective gene transfer. In human sera in which FX had a protective role, Ad5 induced lower levels of complement activation in the presence of FX. We therefore demonstrate for the first time the importance of Ad-FX protection in human samples and highlight subject variability and species-specific differences as key considerations for adenoviral gene therapy.
Jun Nishihira
2012-07-01
Full Text Available The cytokine “macrophage migration inhibitory factor (MIF” is generally recognized as a proinflammatory cytokine, and MIF is involved in broad range of acute and chronic inflammatory states. With regard to glucose metabolism and insulin secretion, MIF is produced by pancreatic β cells and acts as a positive regulator of insulin secretion. In contrast, it is evident that MIF expressed in adipose tissues causes insulin resistance. Concerning MIF gene analysis, we found four alleles: 5-, 6-, 7-and 8-CATT at position −794 of MIF gene in a Japanese population. Genotypes without the 5-CATT allele were more common in the obese subjects than in the lean or overweight groups. It is conceivable that promoter polymorphism in the MIF gene is profoundly linked with obesity relevant to lifestyle diseases, such as diabetes. Obesity has become a serious social issue due to the inappropriate nutritional balance, and the consumption of functional foods (including functional foods to reduce fat mass is expected to overcome this issue. In this context, MIF would be a reliable quantitative biomarker to evaluate the effects of functional foods on adiposity.
Three loop form factors of a massive spin-2 with non-universal coupling
Ahmed, Taushif; Dhani, Prasanna K; Mathews, Prakash; Rana, Narayan; Ravindran, V
2016-01-01
We investigate the interaction of spin-2 fields with those of Standard Model in a model independent framework. We have considered interactions where the spin-2 fields couple to two sets of gauge invariant tensorial operators that are not conserved unlike the energy momentum tensor with different coupling strengths. Such interactions not only change the ultraviolet behaviour of the couplings but also expand the scope of the searches of spin-2 particles at the colliders. We present all the relevant renormalisation constants up to three loop level in QCD and also the form factors that contribute to potential observables. This sets the ground to investigate the phenomenological consequences of these interactions with spin-2 fields through more than one tensorial operator.
Characterization of water-forming NADH oxidases for co-factor regeneration
Rehn, Gustav; Pedersen, Asbjørn Toftgaard; J. Charnock, Simon
an environmentaland economic perspective [1]. Alcohol dehydrogenases (ADH) offer one such alternative. However, the reaction requires the oxidized nicotinamide co-factor (NAD+) that must be recycled due to its high cost contribution. One regeneration method that offers certain advantages is the oxidation of NADH...... using water forming NADH oxidases (NOX-2). The implementation of the ADH/NOX system for alcohol oxidation, however, requires consideration of several different issues. Enzyme activity and stability at relevant pH and temperature conditions, but also the tolerance to the substrates and products present......Traditional chemical methods for alcohol oxidation are often associated with issues such as high consumption of expensive oxidizing agents, generation of metal waste and the use of environmentally undesirable organic solvents. Developing green, selective catalysts is therefore important from...
Bs → f0(980) Transition Form Factors Within the kT Factorization Approach
ZENG Dai-Min; FANG Zhen-Yun
2013-01-01
In the paper,we apply the kT factorization approach to deal with the Bs → f0(980) transition form factors in the large recoil regions,i.e.the small q2 regions.For the purpose,we adopt the B-meson wave-functions ΨB,ψ B and δ that include the three-Fock states contributions to do our discussion.Although the scalar meson f0(980) is widely perceived as the 4-quark bound state (scenario 2),but the distribution amplitudes of 4-quark states are still unknown to us,so we adopt 2-quark model (scenario 1) for scalar meson f0(980) in our discussion.By varying the B-meson wave-function parameters within their reasonable regions,we obtain F0(0) =F+(0) =0.20 ± 0.02,FT(0) =0.24 ± 0.02.Our present results for these form factors are consistent with the light-cone sum rule results obtained in the literature.
$D \\rightarrow a_1, f_1$ transition form factors and semileptonic decays via 3-point QCD sum rules
Zuo, Yabing; He, Linlin; Yang, Wei; Chen, Yan; Hao, Yannan
2016-01-01
By using the 3-point QCD sum rules, we calculate the transition form factors of $D$ decays into the spin triplet axial vector mesons $a_1(1260)$, $f_1(1285) $, $f_1(1420)$. In the calculations, we consider the quark contents of each meson in detail. In view of the fact that the isospin of $a_1(1260)$ is one, we calculate the $D^+ \\rightarrow a_1^0 (1260)$ and $D^0 \\rightarrow a_1^- (1260)$ transition form factors separately. In the case of $ f_1(1285), f_1(1420)$, the mixing between light flavor $SU(3)$ singlet and octet is taken into account. Based on the form factors obtained here, we give predictions for the branching ratios of relevant semileptonic decays, which can be tested in the future experiments.
Chemical Forms of Mercury in Soils and Their Influencing Factors
QINGCHANGLE; MOUSHUSEN; 等
1998-01-01
Experiments were carried out study the transformation of mercury in soils,Results showed that Hg2+ was immediatel converted into other forms once it entered into soils,Bentonite,humus or CaCO3 accelerated the transformaiton of Hg2+ by various mechanisms.Bentonite could convert Hg2+ into residual form eventually,and application of CaCO3 enhanced the formation of inorganic Hg,Humus competed strongly with clay minerals for binding Hg2+,thus increase of soil hums content led to increased formation of organically bound Hg.
Lattice QCD calculation of form factors for $\\Lambda_b \\to \\Lambda(1520) \\ell^+ \\ell^-$ decays
Meinel, Stefan
2016-01-01
Experimental results for mesonic $b \\to s \\mu^+ \\mu^-$ decays show a pattern of deviations from Standard-Model predictions, which could be due to new fundamental physics or due to an insufficient understanding of hadronic effects. Additional information on the $b \\to s \\mu^+ \\mu^-$ transition can be obtained from $\\Lambda_b$ decays. This was recently done using the process $\\Lambda_b \\to \\Lambda \\mu^+ \\mu^-$, where the $\\Lambda$ is the lightest strange baryon. A further interesting channel is $\\Lambda_b \\to p^+ K^- \\mu^+ \\mu^-$, where the $p^+ K^-$ final state receives contributions from multiple higher-mass $\\Lambda$ resonances. The narrowest and most prominent of these is the $\\Lambda(1520)$, which has $J^P=\\frac32^-$. Here we present an ongoing lattice QCD calculation of the relevant $\\Lambda_b \\to \\Lambda(1520)$ form factors. We discuss the choice of interpolating field for the $\\Lambda(1520)$, and explain our method for extracting the fourteen $\\Lambda_b \\to \\Lambda(1520)$ helicity form factors from corr...
The Neutron Electric Form Factor To The Four-momentum Factor Squared = 1.45 (gev/c) 2
Plaster, B R
2004-01-01
The nucleon elastic electromagnetic form factors are fundamental quantities needed for an understanding of nucleon and nuclear electromagnetic structure. The evolution of the Sachs electric and magnetic form factors with Q2, the square of the four-momentum transfer, is related to the distribution of charge and magnetization within the nucleon. High precision measurements of the nucleon form factors are essential for stringent tests of our current theoretical understanding of confinement within the nucleon. Measurements of the neutron form factors, in particular, those of the neutron electric form factor, have been notoriously difficult due to the lack of a free neutron target and the vanishing integral charge of the neutron. Indeed, a precise measurement of the neutron electric form factor has eluded experimentalists for decades; however, with the advent of high duty-factor polarized electron beam facilities, experiments employing polarization degrees of freedom have finally yielded the first precise measure...
Investigation on influence factors of dual laterologs curve form
Xiaomin FAN; Lei LU
2008-01-01
In order to investigate the influences of caliper, formation thickness and invaded zone on the form of dual laterologs, forward modeling technique were applied to calculate the dual laterologs for different cases. The result shows that the resistivity logs become smoother and lower as the borehole diameter increases, the increase of the contrast between mud resistivity and formation resistivity induce the logs to be more pointed. When the formation thickness is less than 1m, the two-peak on the logs for resistive invasion vanished, and for thickness between 1 m and 4 m, the form of logs does not vary significantly. If the formation thickness is greater than 4 m, a platform appears on the logs at the middle of the formation. The thinner the invaded zone is, the more obvious the invasion feature on the laterologs is. For thick invaded zone the form of logs tend to be that of an uninvaded resistive formation. The form and amplitude of logs depend on the resistivity contrast between invaded zone, uninvaded formation and adjacentlayers.
FACTORS FORMING RELATIONSHIPS AND EVERYDAY RUSSIAN AND BELARUSIANS
Emir Nodarievich Tuzhba
2016-11-01
Full Text Available Purpose. It consists in the analysis of the factors influencing the process of interaction, the nature of relationships and everyday life of the Russian and Belarusian communities. Methodology. Use the ideas of the system, interactionist, phenomenological and socio-psychological approaches. The empirical base totaled questionnaire data of the Russian population of the Krasnodar Territory; secondary analysis of sociological data of Russian and Belarusian research teams on studies. Results. Identified and analyzed factors of relationships and the culture of everyday life, especially their impact on the processes of interaction between Russian and Belarusian ethnic communities. Practical implications. Knowledge of the factors and content of the mutual influence of ethnic and cultural practices of the ethnic communities of Belarus and Russia will help to predict the interaction processes contribute to their consolidation and integration.
Bound Nucleon Form Factors, Quark-Hadron Duality, and Nuclear EMC Effect
Tsushima, K; Melnitchouk, W; Saitô, K; Thomas, A W
2003-01-01
We discuss the electromagnetic form factors, axial form factors, and structure functions of a bound nucleon in the quark-meson coupling (QMC) model. Free space nucleon form factors are calculated using the improved cloudy bag model (ICBM). After describing finite nuclei and nuclear matter in the quark-based QMC model, we compute the in-medium modification of the bound nucleon form factors in the same framework. Finally, limits on the medium modification of the bound nucleon $F_2$ structure function are obtained using the calculated in-medium electromagnetic form factors and local quark-hadron duality.
Michael Roth
2011-01-01
Full Text Available Epithelial cells, fibroblasts and smooth muscle cells together form and give structure to the airway wall. These three tissue forming cell types are structure giving elements and participate in the immune response to inhaled particles including allergens and dust. All three cell types actively contribute to the pathogenesis of chronic inflammatory lung diseases such as asthma and chronic obstructive pulmonary disease (COPD. Tissue forming cells respond directly to allergens through activated immunoglobulins which then bind to their corresponding cell surface receptors. It was only recently reported that allergens and particles traffic through epithelial cells without modification and bind to the immunoglobulin receptors on the surface of sub-epithelial mesenchymal cells. In consequence, these cells secrete pro-inflammatory cytokines, thereby extending the local inflammation. Furthermore, activation of the immunoglobulin receptors can induce proliferation and tissue remodeling of the tissue forming cells. New studies using anti-IgE antibody therapy indicate that the inhibition of immunoglobulins reduces the response of tissue forming cells. The unmeasured questions are: (i why do tissue forming cells express immunoglobulin receptors and (ii do tissue forming cells process immunoglobulin receptor bound particles? The focus of this review is to provide an overview of the expression and function of various immunoglobulin receptors.
The role of seasonal factor in congenital abnormality forming
O. V. Antonov
2012-01-01
Full Text Available The results of prevalence, structure and timerisk study in children birth with malformations inOmskin the period of 1998—2008 are presented. Birth of children with congenital abnormality weight average index accounted for (47.72 ± 0.66%. Musculoskeletal and cardiovascular malformations prevailed in birth abnormality total number structure. According to ICD-10 the congenital malformations were united in groups and seasonal variation indices nave been determined for them. Study results indicated the predominance of children conception cases with high risk malformations forming in August, November and December.
Axial form factors of the octet baryons in a covariant quark model
Ramalho, G
2015-01-01
We study the weak interaction axial form factors of the octet baryons, within the covariant spectator quark model, focusing on the dependence of four-momentum transfer squared, Q^2. In our model the axial form factors G_A(Q^2) (axial-vector form factor) and G_P(Q^2) (induced pseudoscalar form factor), are calculated based on the constituent quark axial form factors and the octet baryon wave functions. The quark axial current is parametrized by the two constituent quark form factors, the axial-vector form factor g_A^q(Q^2), and the induced pseudoscalar form factor g_P^q(Q^2). The baryon wave functions are composed of a dominant S-state and a P-state mixture for the relative angular momentum of the quarks. First, we study in detail the nucleon case. We assume that the quark axial-vector form factor g_A^q(Q^2) has the same function form as that of the quark electromagnetic isovector form factor. The remaining parameters of the model, the P-state mixture and the Q^2-dependence of g_P^q(Q^2), are determined by a f...
Farrand, W. H.; Lane, M. D.
1999-03-01
The reflectance and emittance properties of minerals associated with spring formed ferricretes and acid mine drainage materials is described. It is suggested that they may be appropriate analog materials for certain regions on Mars.
Lane, Belize; Pasternack, Gregory; Sandoval-Solis, Samuel
2017-04-01
Rivers are highly complex, dynamic systems that support numerous ecosystem functions including transporting sediment, modulating biogeochemical processes, and regulating habitat availability for native species. The extent and timing of these functions is largely controlled by the interplay of hydrologic dynamics (i.e., flow) and the shape and structure of the river channel (i.e., form). In spite of this, the majority of river restoration studies are limited to the influence of flow on ecosystem function without regard for the role of channel form in modulating eco-hydraulic response. The few studies that have effectively examined the flow-form interface highlight the scientific and management value of such analyses, but are highly resource intensive. This study represents a first attempt to apply synthetic channel design to the evaluation of river flow-form-function linkages, with the aim of improving basic understanding of how the interplay between flow and form affects ecosystem functions across a range of regionally-significant flows and forms with minimal resource requirements. Archetypal Mediterranean-montane channel types were used to guide the design of 3D synthetic morphologies. These morphologies were then used to quantify 2D eco-hydraulic response to different channel configurations under select hydrologic scenarios (distinguished by alteration and water year type). The eco-hydraulic performance of alternative flow-form settings, based on spatiotemporal patterns of depth and velocity, was evaluated with respect to a suite of river ecosystem functions related to geomorphic diversity, aquatic habitat, and riparian habitat. The methods described herein provide a potential design and inventory tool for quantifying river ecosystem functions and management trade-offs of alternative flow-form combinations with minimal resource and data requirements. While addressing specific scientific questions of interest for Mediterranean-montane rivers, the general framework
Scheerans, Christian; Heinig, Roland; Mueck, Wolfgang
2015-03-01
Recently, the European Medicines Agency (EMA) published the new draft guideline on the pharmacokinetic and clinical evaluation of modified release (MR) formulations. The draft guideline contains the new requirement of performing multiple dose (MD) bioequivalence studies, in the case when the MR formulation is expected to show 'relevant' drug accumulation at steady state (SS). This new requirement reveals three fundamental issues, which are discussed in the current work: first, measurement for the extent of drug accumulation (MEDA) predicted from single dose (SD) study data; second, its relationship with the percentage residual area under the plasma concentration-time curve (AUC) outside the dosing interval (τ) after SD administration, %AUC(τ-∞)SD ; and third, the rationale for a threshold of %AUC(τ-∞)SD that predicts 'relevant' drug accumulation at SS. This work revealed that the accumulation ratio RA,AUC , derived from the ratio of the time-averaged plasma concentrations during τ at SS and after SD administration, respectively, is the 'preferred' MEDA for MR formulations. A causal relationship was derived between %AUC(τ-∞)SD and RA,AUC , which is valid for any drug (product) that shows (dose- and time-) linear pharmacokinetics regardless of the shape of the plasma concentration-time curve. Considering AUC thresholds from other guidelines together with the causal relationship between %AUC(τ-∞)SD and RA,AUC indicates that values of %AUC(τ-∞)SD ≤ 20%, resulting in RA,AUC ≤ 1.25, can be considered as leading to non-relevant drug accumulation. Hence, the authors suggest that 20% for %AUC(τ-∞)SD is a reasonable threshold and selection criterion between SD or MD study designs for bioequivalence studies of new MR formulations.
Gladis Barberis Pérez
2008-04-01
Full Text Available
Background: Major congenital defects have an impact on perinatal mortality and morbidity with economic and social consequences. Objective: To determine the relevant risk factors linked to the occurrence of congenital defects in Cienfuegos between 2000 and 2005. Methods: A case-control study was carried out. Women with fetus or newborns with major congenital defects formed the case group (255 while the control group consisted of a similar number of healthy children selected each year by a randomized simple sample. The variables gathered by the Cuban Congenital Defects Records were studied. Chi-Square method was used with 95% of accuracy and a reliance rate of 95%; logistic regression was used with the Wald test. Results: There was a predominance of Central Nervous System defects (28, 6%. The most relevant risk factors were a history of congenital defects, smoking habits, and acute infection during the first three months, as well as belong to the third birth on. Conclusion: The most clinical relevant risks factors were the congenital defect history and the acute infection during the firs three months.
Fundamento: Las malformaciones congénitas mayores influyen en la morbimortalidad perinatal, lo que tiene implicaciones sociales y económicas. Objetivo: Determinar los factores de riesgo relevantes, asociados a la aparición de malformaciones congénitas mayores, en la provincia Cienfuegos en el período 2000-2005. Métodos: Se realizó un estudio de casos y controles no pareados. Las mujeres registradas con fetos o recién nacidos con malformaciones congénitas mayores, constituyeron el grupo de casos (255, mientras que el grupo control estuvo conformado por un número similar de niños sanos, seleccionados en cada año, por un muestreo aleatorio simple. Se estudiaron las variables recogidas en el modelo
Kocken, P.L.; Dorst, A.G. van; Schaalma, H.
2006-01-01
A study into the relevance of cultural factors in predicting condom-use intentions among Antillean migrants in the Netherlands is described in this article. The association between the intention to use condoms with a new sexual partner and a perceived taboo on discussing sex, beliefs about sex educa
Kocken, P. L.; van Dorst, A. G.; Schaalma, H.
2006-01-01
A study into the relevance of cultural factors in predicting condom-use intentions among Antillean migrants in the Netherlands is described in this article. The association between the intention to use condoms with a new sexual partner and a perceived taboo on discussing sex, beliefs about sex education and machismo beliefs on gender and power…
Kocken, P.L.; Dorst, A.G. van; Schaalma, H.
2006-01-01
A study into the relevance of cultural factors in predicting condom-use intentions among Antillean migrants in the Netherlands is described in this article. The association between the intention to use condoms with a new sexual partner and a perceived taboo on discussing sex, beliefs about sex
Heusinkveld, M.; Mughini-Gras, L.; Pijnacker, R.; Vennema, H.; Scholts, R.; van Huisstede-Vlaanderen, K. W.; Kortbeek, T.; Kooistra-Smid, M.; van Pelt, W.
2016-01-01
Acute gastroenteritis (AGE) morbidity remains high amongst preschool children, posing a significant societal burden. Empirical data on AGE-causing agents is needed to gauge their clinical relevance and identify agent-specific targets for control. We assessed the prevalence, risk factors and associat
Escobar-Rodríguez, Tomás; Carvajal-Trujillo, Elena; Monge-Lozano, Pedro
2014-01-01
Social media technologies are becoming a fundamental component of education. This study extends the Unified Theory of Acceptance and Use of Technology (UTAUT) to identify factors that influence the perceived advantages and relevance of Facebook as a learning tool. The proposed model is based on previous models of UTAUT. Constructs from previous…
Heusinkveld, M.; Mughini-Gras, L.; Pijnacker, R.; Vennema, H.; Scholts, R.; van Huisstede-Vlaanderen, K. W.; Kortbeek, T.; Kooistra-Smid, M.; van Pelt, W.
2016-01-01
Acute gastroenteritis (AGE) morbidity remains high amongst preschool children, posing a significant societal burden. Empirical data on AGE-causing agents is needed to gauge their clinical relevance and identify agent-specific targets for control. We assessed the prevalence, risk factors and
Heusinkveld, M.; Mughini-Gras, L.; Pijnacker, R.; Vennema, H.; Scholts, R.; van Huisstede-Vlaanderen, K. W.; Kortbeek, T.; Kooistra-Smid, M.; van Pelt, W.
2016-01-01
Acute gastroenteritis (AGE) morbidity remains high amongst preschool children, posing a significant societal burden. Empirical data on AGE-causing agents is needed to gauge their clinical relevance and identify agent-specific targets for control. We assessed the prevalence, risk factors and associat
Kocken, P.L.; Dorst, A.G. van; Schaalma, H.
2006-01-01
A study into the relevance of cultural factors in predicting condom-use intentions among Antillean migrants in the Netherlands is described in this article. The association between the intention to use condoms with a new sexual partner and a perceived taboo on discussing sex, beliefs about sex educa
Kocken, P. L.; van Dorst, A. G.; Schaalma, H.
2006-01-01
A study into the relevance of cultural factors in predicting condom-use intentions among Antillean migrants in the Netherlands is described in this article. The association between the intention to use condoms with a new sexual partner and a perceived taboo on discussing sex, beliefs about sex education and machismo beliefs on gender and power…
2014-06-01
currently in play ( Samuelson and Zeckhauser, 1988). A related notion is regret avoidance: since people experience greater regret for action than for...for Basic Research on Social and Organizational Factors Relevant to Small Units 56 THE CONTEXT OF MILITARY ENVIRONMENTS Samuelson , W., and R. Zeckhauser
Resource Form Factor and Installation of GFA Controllers
DeSteese, John G.; Hammerstrom, Donald J.
2009-11-15
The focus of this task is to optimize the form and placement of a controller comprising the Grid Friendly™ appliance (GFA) controller, power supply and power relay (and/or a solid-state power electronic switch) that would command a domestic water heater to shed its load in response to stress on the electric power grid. The GFA controller would disconnect the water heater from its supply circuit whenever it senses a low voltage signal or other indicators of system stress communicated via the electric power distribution system. Power would be reconnected to the appliance when the GFA controller senses the absence of these signals. This project has also considered more frequent cycling of this controller’s relay switch to perform demand-side frequency regulation. The principal criteria considered in this optimization are reliability, cost and life expectancy of the GFA components. The alternative embodiments of the GFA equipment under consideration are: Option 1- installation inside the insulation space of the water heater between the tank and jacket Option 2 containment in a separate nearby electrical enclosure Option 3 - as a modification or adjunct to the distribution panel housing and/or the breaker that protects the water heater supply circuit.
Pseudoscalar meson electromagnetic form factor at high Q2 from full lattice QCD
Koponen, J.; Zimermmane-Santos, A. C.; Davies, C. T. H.; Lepage, G. P.; Lytle, A. T.; Hpqcd Collaboration
2017-09-01
We give an accurate determination of the vector (electromagnetic) form factor, F (Q2) , for a light pseudoscalar meson up to squared momentum transfer Q2 values of 6 GeV2 for the first time from full lattice QCD, including u , d , s and c quarks in the sea at multiple values of the lattice spacing. Our results show good control of lattice discretization and sea quark mass effects. We study a pseudoscalar meson made of valence s quarks but the qualitative picture obtained applies also to the π meson, relevant to upcoming experiments at Jefferson Lab. We find that Q2F (Q2) becomes flat in the region between Q2 of 2 GeV2 and 6 GeV2, with a value well above that of the asymptotic perturbative QCD expectation, but well below that of the vector-meson dominance pole form appropriate to low Q2 values. Our calculations show that we can reach higher Q2 values in future to shed further light on where the perturbative QCD result emerges.
Highly Efficient Small Form Factor LED Retrofit Lamp
Steven Allen; Fred Palmer; Ming Li
2011-09-11
This report summarizes work to develop a high efficiency LED-based MR16 lamp downlight at OSRAM SYLVANIA under US Department of Energy contract DE-EE0000611. A new multichip LED package, electronic driver, and reflector optic were developed for these lamps. At steady-state, the lamp luminous flux was 409 lumens (lm), luminous efficacy of 87 lumens per watt (LPW), CRI (Ra) of 87, and R9 of 85 at a correlated color temperature (CCT) of 3285K. The LED alone achieved 120 lumens per watt efficacy and 600 lumen flux output at 25 C. The driver had 90% electrical conversion efficiency while maintaining excellent power quality with power factor >0.90 at a power of only 5 watts. Compared to similar existing MR16 lamps using LED sources, these lamps had much higher efficacy and color quality. The objective of this work was to demonstrate a LED-based MR16 retrofit lamp for replacement of 35W halogen MR16 lamps having (1) luminous flux of 500 lumens, (2) luminous efficacy of 100 lumens per watt, (3) beam angle less than 40{sup o} and center beam candlepower of at least 1000 candelas, and (4) excellent color quality.
Nucleon Charges, Form-factors and Neutron EDM
Gupta, Rajan; Cirigliano, Vincenzo; Lin, Huey-Wen; Yoon, Boram
2016-01-01
We present an update of our analysis of statistical and systematic errors in the calculation of iso-vector scalar, axial and tensor charges of the nucleon. The calculations are done using $N_f=2+1+1$ flavor HISQ ensembles generated by the MILC Collaboration at three values of the lattice spacing ($a=0.12,\\ 0.09,$ and $0.06$ fm) and three values of the quark mass ($M_\\pi \\approx 310,\\ 220$ and $130$ MeV); and clover fermions for calculating the correlation functions, i.e., we use a clover-on-HISQ lattice formulation. The all-mode-averaging method allows us to increase the statistics by a factor of eight for the same computational cost leading to a better understanding of and control over excited state contamination. Our current results, after extrapolation to the continuum limit and physical pion mass are $g_A^{u-d} = 1.21(3)$, $g_T^{u-d} = 1.005(59)$ and $g_S^{u-d} = 0.95(12) $. Further checks of control over all systematic errors, especially in $g_A^{u-d}$, are still being performed. Using results for the fl...
Form factors of the monodromy matrix entries in gl(2|1)-invariant integrable models
Hutsalyuk, A; Pakuliak, S Z; Ragoucy, E; Slavnov, N A
2016-01-01
We study integrable models solvable by the nested algebraic Bethe ansatz and described by $\\mathfrak{gl}(2|1)$ or $\\mathfrak{gl}(1|2)$ superalgebras. We obtain explicit determinant representations for form factors of the monodromy matrix entries. We show that all form factors are related to each other at special limits of the Bethe parameters. Our results allow one to obtain determinant formulas for form factors of local operators in the supersymmetric t-J model.
Electromagnetic form factor via Minkowski and Euclidean Bethe-Salpeter amplitudes
Karmanov, V A; Mangin-Brinet, M
2007-01-01
The electromagnetic form factors calculated through Euclidean Bethe-Salpeter amplitude and through the light-front wave function are compared with the one found using the Bethe-Salpeter amplitude in Minkowski space. The form factor expressed through the Euclidean Bethe-Salpeter amplitude (both within and without static approximation) considerably differs from the Minkowski one, whereas form factor found in the light-front approach is almost indistinguishable from it.
Electromagnetic form factors of the baryon octet in the perturbative chiral quark model
Cheedket, S; Gutsche, T; Faessler, A; Pumsa-ard, K; Yan, Y; Gutsche, Th.; Faessler, Amand
2002-01-01
We apply the perturbative chiral quark model at one loop to analyze the electromagnetic form factors of the baryon octet. The analytic expressions for baryon form factors, which are given in terms of fundamental parameters of low-energy pion-nucleon physics(weak pion decay constant, axial nucleon coupling, strong pion-nucleon form factor), and the numerical results for baryon magnetic moments, charge and magnetic radii are presented. Our results are in good agreement with experimental data.
Form factors of the monodromy matrix entries in gl (2 | 1)-invariant integrable models
Hutsalyuk, A.; Liashyk, A.; Pakuliak, S. Z.; Ragoucy, E.; Slavnov, N. A.
2016-10-01
We study integrable models solvable by the nested algebraic Bethe ansatz and described by gl (2 | 1) or gl (1 | 2) superalgebras. We obtain explicit determinant representations for form factors of the monodromy matrix entries. We show that all form factors are related to each other at special limits of the Bethe parameters. Our results allow one to obtain determinant formulas for form factors of local operators in the supersymmetric t- J model.
Calculation of the Nucleon Axial Form Factor Using Staggered Lattice QCD
Meyer, Aaron S; Kronfeld, Andreas S; Li, Ruizi; Simone, James N
2016-01-01
The nucleon axial form factor is a dominant contribution to errors in neutrino oscillation studies. Lattice QCD calculations can help control theory errors by providing first-principles information on nucleon form factors. In these proceedings, we present preliminary results on a blinded calculation of $g_A$ and the axial form factor using HISQ staggered baryons with 2+1+1 flavors of sea quarks. Calculations are done using physical light quark masses and are absolutely normalized. We discuss fitting form factor data with the model-independent $z$ expansion parametrization.
Toledo, Joao; George, Leyanna; Martinez, Eric; Lazaro, Adhara; Han, Wai Wai; Coelho, Giovanini E; Runge Ranzinger, Silvia; Horstick, Olaf
2016-01-01
Patients with dengue fever and comorbidities seem to be at higher risk of developing complications and/or severe dengue compared to healthier individuals. This study systematically reviews the evidence related to comorbidities and dengue. A systematic literature review was performed in five databases (EMBASE, PUBMED, Global Health, SciELO, Cochrane) and grey literature for full-text articles since its inceptions until October 10, 2015. A total of 230 articles were retrieved. Sixteen studies were analysed after applying all inclusion and exclusion criteria. Seven case control studies and nine retrospective cohort studies showed that comorbidities may contribute to severe dengue, especially 1) cardiovascular disease, 2) stroke, 3) diabetes, 4) respiratory disease and 5) renal disease, as well as old age. However, due to heterogeneity in studies, the real estimate effect of comorbidities as modifiers of dengue severity could not be established. Further research in regions with high prevalence of dengue infection would contribute to a better understanding of the relevance of comorbidities in severe dengue, especially with a standardised protocol, for outcomes, specific comorbidities, study design-best using prospective designs-and sample sizes.
Toledo, Joao; George, Leyanna; Martinez, Eric; Lazaro, Adhara; Han, Wai Wai; Coelho, Giovanini E.; Runge Ranzinger, Silvia; Horstick, Olaf
2016-01-01
Patients with dengue fever and comorbidities seem to be at higher risk of developing complications and/or severe dengue compared to healthier individuals. This study systematically reviews the evidence related to comorbidities and dengue. A systematic literature review was performed in five databases (EMBASE, PUBMED, Global Health, SciELO, Cochrane) and grey literature for full-text articles since its inceptions until October 10, 2015. A total of 230 articles were retrieved. Sixteen studies were analysed after applying all inclusion and exclusion criteria. Seven case control studies and nine retrospective cohort studies showed that comorbidities may contribute to severe dengue, especially 1) cardiovascular disease, 2) stroke, 3) diabetes, 4) respiratory disease and 5) renal disease, as well as old age. However, due to heterogeneity in studies, the real estimate effect of comorbidities as modifiers of dengue severity could not be established. Further research in regions with high prevalence of dengue infection would contribute to a better understanding of the relevance of comorbidities in severe dengue, especially with a standardised protocol, for outcomes, specific comorbidities, study design—best using prospective designs—and sample sizes. PMID:26727113
Transition Form Factors: A Unique Opportunity to Connect Non-Perturbative Strong Interactions to QCD
Gothe, Ralf W. [University of South Carolina, Columbia, SC (United States)
2014-01-01
Meson-photoproduction measurements and their reaction-amplitude analyses can establish more sensitively, and in some cases in an almost model-independent way, nucleon excitations and non-resonant reaction amplitudes. However, to investigate the strong interaction from explored — where meson-cloud degrees of freedom contribute substantially to the baryon structure — to still unexplored distance scales — where quark degrees of freedom dominate and the transition from dressed to current quarks occurs — we depend on experiments that allow us to measure observables that are probing this evolving non-perturbative QCD regime over its full range. Elastic and transition form factors are uniquely suited to trace this evolution by measuring elastic electron scattering and exclusive single-meson and double-pion electroproduction cross sections off the nucleon. These exclusive measurements will be extended to higher momentum transfers with the energy-upgraded CEBAF beam at JLab to study the quark degrees of freedom, where their strong interaction is responsible for the ground and excited nucleon state formations. After establishing unprecedented high-precision data, the imminent next challenge is a high-quality analysis to extract these relevant electrocoupling parameters for various resonances that then can be compared to state-of-the-art models and QCD-based calculations. Recent results will demonstrate the status of the analysis and of their theoretical descriptions, and an experimental and theoretical outlook will highlight what shall and may be achieved in the new era of the 12-GeV upgraded transition form factor program.
Tatjana M H Niers
Full Text Available BACKGROUND: Levels of circulating vascular endothelial growth factor (VEGF have widely been used as biomarker for angiogenic activity in cancer. For this purpose, non-standardized measurements in plasma and serum were used, without correction for artificial VEGF release by platelets activated ex vivo. We hypothesize that "true" circulating (cVEGF levels in most cancer patients are low and unrelated to cancer load or tumour angiogenesis. METHODOLOGY: We determined VEGF levels in PECT, a medium that contains platelet activation inhibitors, in citrate plasma, and in isolated platelets in 16 healthy subjects, 18 patients with metastatic non-renal cancer (non-RCC and 12 patients with renal cell carcinoma (RCC. In non-RCC patients, circulating plasma VEGF levels were low and similar to VEGF levels in controls if platelet activation was minimized during the harvest procedure by PECT medium. In citrate plasma, VEGF levels were elevated in non-RCC patients, but this could be explained by a combination of increased platelet activation during blood harvesting, and by a two-fold increase in VEGF content of individual platelets (controls: 3.4 IU/10(6, non-RCC: 6.2 IU/10(6 platelets, p = 0.001. In contrast, cVEGF levels in RCC patients were elevated (PECT plasma: 64 pg/ml vs. 21 pg/ml, RCC vs. non-RCC, p<0.0001, and not related to platelet VEGF concentration. CONCLUSIONS: Our findings suggest that "true" freely cVEGF levels are not elevated in the majority of cancer patients. Previously reported elevated plasma VEGF levels in cancer appear to be due to artificial release from activated platelets, which in cancer have an increased VEGF content, during the blood harvest procedure. Only in patients with RCC, which is characterized by excessive VEGF production due to a specific genetic defect, were cVEGF levels elevated. This observation may be related to limited and selective success of anti-VEGF agents, such as bevacizumab and sorafenib, as monotherapy in
Proton form-factor dependence of the finite-size correction to the Lamb shift in muonic hydrogen
Carroll, J D; Rafelski, J; Miller, G A
2011-01-01
The measurement of the 2P^{F=2}_{3/2} to 2S^{F=1}_{1/2} transition in muonic hydrogen by Pohl et al. and subsequent analysis has led to the conclusion that the rms radius of the proton differs from the accepted (CODATA) value by approximately 4%, corresponding to a 4.9 sigma discrepancy. We investigate the finite-size effects - in particular the dependence on the shape of the proton electric form-factor - relevant to this transition using bound-state QED with nonperturbative, relativistic Dirac wave-functions for a wide range of idealised charge-distributions and a parameterization of experimental data in order to comment on the extent to which the perturbation-theory analysis which leads to the above conclusion can be confirmed. We find no statistically significant dependence of this correction on the shape of the proton form-factor.
Relevance of risk factors of breast cancer in women: An Eastern Indian scenario
Ranen Kanti Aich
2016-01-01
Conclusion: Risk factors for breast cancer do not differ significantly between developed and developing countries. Hence appropriate time has come for developing countries to incorporate breast cancer risk factors in health education and to consider pharmacological interventions in high risk women.
Connection between the elastic GEp/GMp and P to Delta form factors
Stoler, P
2003-01-01
It is suggested that the falloff in Qsq of the P to Delta magnetic form factor GM* is related to the recently observed falloff of the elastic electric form factor GEp/GMp. Calculation is carried out in the framework of a two-body GPD mechanism.
η′-g*-g transition form factor with gluon content contribution tested
Muta, Taizo; Yang, Mao-Zhi
2000-01-01
We study the η′-g*-g transition form factor by using the η′ wave function constrained by the experimental data on the η′-γ*-γ transition form factor provided by CLEO and L3. We also take into account the contribution of the possible gluonic content of the η′ meson.
$\\eta'-g^*-g$ Transition Form Factor with Gluon Content Contribution Tested
Muta, Taizo; Yang, Mao-Zhi
1999-01-01
We study the $\\eta'-g^*-g$ transition form factor by using the $\\eta'$ wave function constrained by the experimental data on the $\\eta'-\\gamma^*-\\gamma$ transition form factor provided by CLEO and L3 . We also take into account the contribution of the possible gluonic content of the $\\eta'$ meson.
$\\eta'-g*-g$ Transition Form Factor with Gluon Content Contribution Tested
Muta, T; Muta, Taizo; Yang, Mao-Zhi
2000-01-01
We study the $\\eta'-g^*-g$ transition form factor by using the $\\eta'$ wave function constrained by the experimental data on the $\\eta'-\\gamma^*-\\gamma$ transition form factor provided by CLEO and L3 . We also take into account the contribution of the possible gluonic content of the $\\eta'$ meson.
Eisele, R; Maier, E; Kinzl, L; Gude, U
2004-04-01
The presented thromboprophylactic concept includes weight bearing and ankle motion as well as breathing therapy and drug prophylaxis (antiphlogistics, analgesic drugs, heparin). Routinely performed ultrasound screening of the deep veins (legs and pelvis) before release showed a low DVT incidence of 2.5% in a prospective clinical observation of 841 inpatients. Obesity, venous insufficiency, and a history of previous thromboembolic events were associated with a significantly increased risk of thrombosis (relative risk 4.1, 4,9, and 5.8, respectively) The duration of immobilization also had a relevant influence indicating that early postoperative physiotherapy in traumatology and orthopedic surgery has a widely underestimated thromboprophylactic effect.
关联理论对称谓语的认知解读%Cognitive Interpretation of Address Forms in Perspective of Relevance Theory
熊永红; 杨央
2011-01-01
关联理论认为在交际中,对交际意图的识别就是对言语意义的理解。交际中称谓语的使用过程就是称谓者（说话人）与被称谓者（受众或读者）通过关联图式的打破或激活方式来相互认知的过程。这就是关联理论框架下称谓语的认知解读机制。%Relevance theory holds that the identification of communicative intentions is the comprehension of verbal meanings in communication.The appliance of address forms in verbal communication is a cognitive process performed between an addresser（speaker） and an addressee（hearer） by way of the breaking and activation of relevance schema.This is a cognitive interpretation of address forms in perspective of relevance theory.
On super form factors of half-BPS operators in N=4 super Yang-Mills
Penante, Brenda; Travaglini, Gabriele; Wen, Congkao
2014-01-01
We compute form factors of half-BPS operators in N=4 super Yang-Mills dual to massive Kaluza-Klein modes in supergravity. These are appropriate supersymmetrisations T_k of the scalar operators Tr(\\phi^k) for any k, which for k=2 give the chiral part of the stress-tensor multiplet operator. Using harmonic superspace, we derive simple Ward identities for these form factors, which we then compute perturbatively at tree level and one loop. We propose a novel on-shell recursion relation which links form factors with different numbers of fields. Using this, we conjecture a general formula for the n-point MHV form factors of T_k for arbitrary k and n. Finally, we use supersymmetric generalised unitarity to derive compact expressions for all one-loop MHV form factors of T_k in terms of one-loop triangles and finite two-mass easy box functions.
Skyrme-Model $\\pi NN$ Form Factor and Nucleon-Nucleon Interaction
Holzwarth, G
1997-01-01
We apply the strong $\\pi NN$ form factor, which emerges from the Skyrme model, in the two-nucleon system using a one-boson-exchange (OBE) model for the nucleon-nucleon (NN) interaction. Deuteron properties and phase parameters of NN scattering are reproduced well. In contrast to the form factor of monopole shape that is traditionally used in OBE models, the Skyrme form factor leaves low momentum transfers essentially unaffected while it suppresses the high-momentum region strongly. It turns out that this behavior is very appropriate for models of the NN interaction and makes possible to use a soft pion form factor in the NN system. As a consequence, the $\\pi N$ and the $NN$ systems can be described using the same soft $\\pi NN$ form factor, which is impossible with the monopole.
On-shell Diagrams, Gra{\\ss}mannians and Integrability for Form Factors
Frassek, Rouven; Nandan, Dhritiman; Wilhelm, Matthias
2015-01-01
We apply on-shell and integrability methods that have been developed in the context of scattering amplitudes in N=4 SYM theory to tree-level form factors of this theory. Focussing on the colour-ordered super form factors of the chiral part of the stress-energy multiplet as an example, we show how to systematically construct on-shell diagrams for these form factors with the minimal form factor as an additional building block. Moreover, we obtain analytic representations in terms of Gra{\\ss}mannian integrals in spinor helicity, twistor and momentum twistor variables. While Yangian invariance is broken by the operator insertion, we find that form factors are eigenstates of the integrable transfer matrix. As a consequence, we can construct them via the method of R operators, which also allows to introduce deformations that preserve the integrable structure.
Effect of the bound nucleon form factors on charged-current neutrino-nucleus scattering
Tsushima, K; Saitô, K; Kim, Hungchong
2003-01-01
We study the effect of bound nucleon form factors on charged-current neutrino-nucleus scattering. The bound nucleon form factors associated with the vector and axial-vector currents are calculated in the quark-meson coupling model. We compute the inclusive $^{12}$C($nu_mu,mu^-$)$X$ differential and total cross sections, which have been measured by the LSND collaboration at Los Alamos, using a relativistic Fermi gas model with the calculated bound nucleon form factors. It is shown that the bound nucleon form factors reduce the total cross section by about 8% relative to that calculated with the free nucleon form factors, where most of the conventional calculations overestimate the total cross section data by about 30% to 100%.
Pseudo-scalar meson form factors with maximally twisted Wilson fermions at Nf = 2
Simula, S
2007-01-01
We present preliminary results for various electroweak form factors of pseudo-scalar mesons using the tree-level improved Symanzik gauge action and the maximally twisted mass fermionic action with Nf = 2 dynamical flavors. Our results, obtained for both light and heavy quark masses at a single lattice spacing (a ~ 0.09 fm) and at a single lattice volume (V * T = 24**3 * 48), exhibit a quite remarkable statistical precision thanks to the use of all-to-all quark propagators computed with a stochastic method. Moreover very low values of the four-momentum transfer are achieved by making use of twisted boundary conditions on the valence quark fields. The mass dependence of the pion charge radius is analyzed using Chiral Perturbation Theory, obtaining clear evidence of relevant two-loop contributions. The universal Isgur-Wise function is computed from heavy-to-heavy electromagnetic transitions and its slope in the case of $u(d)$ spectator quarks is found to be rho(IW)**2 = 0.77 +/- 0.28, where the error is statisti...
Proton electromagnetic form factors: Basic notions, present achievements and future perspectives
Pacetti, Simone, E-mail: simone.pacetti@pg.infn.it [Dipartimento di Fisica e Geologia dell’Universitá degli Studi di Perugia and INFN Sezione di Perugia, 06123 Perugia (Italy); Baldini Ferroli, Rinaldo [INFN, Laboratori Nazionali di Frascati, 00044 Frascati (Italy); Tomasi-Gustafsson, Egle [CEA, IRFU, SPhN, Saclay, 91191 Gif-sur-Yvette Cedex (France); CNRS/IN2P3, Institut de Physique Nucléaire, UMR 8608, 91406 Orsay (France)
2015-01-20
The aim of this report is to give basic notions on electromagnetic hadron form factors (FFs), as they are understood at the present time, to summarize and analyze the present experimental results and available theoretical models and to open a view on future perspectives. FFs are fundamental quantities, which describe the internal, dynamical structure of hadrons. Although the theoretical formalism was settled in the middle of last century, as well as the first experiments in electron–proton elastic scattering for which R. Hofstadter got the Nobel prize in 1961, a renewed activity is due to recent, surprising results and to the opening of new experimental possibilities. An elegant formalism was built on the assumption of a hadron electromagnetic interaction based on the exchange of a virtual photon of four-momentum q{sup 2}. In this case FFs are analytic functions of only one variable, q{sup 2}, and the electromagnetic vertex γ{sup ∗}hh (h is any hadron) is defined by two structure functions, which, in turn, are expressed in terms of (2S+1) FFs, S being the hadron spin, assuming parity and time-invariance. Our aim is to anticipate the potentiality contained in the future data, combined with the present knowledge, to point out the relevant observables and the most significative measurements, and to give predictions to be compared to the data when they will be available.
48 CFR 247.372 - DD Form 1654, Evaluation of Transportation Cost Factors.
2010-10-01
... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false DD Form 1654, Evaluation... Transportation in Supply Contracts 247.372 DD Form 1654, Evaluation of Transportation Cost Factors. Contracting personnel may use the DD Form 1654 to furnish information to the transportation office for development...
E E Shults
2017-12-01
Full Text Available The article considers reasons for radical mass forms of social protest in the context of the ‘Malthusian trap’ and structural-demographic theory of Jack Goldstone, which have become popular in the last two decades. The author critically evaluates these two conceptions and comes to the conclusion that the principles they underline are just concomitant factors, i.e. additional risk factors for political systems and regimes, rather than causes of radical mass forms of social protest. The author suggests a method of analysis that consists of studying the circumstances, i.e. the wide historical context, in which mass forms of social protest usually emerge, and provides a large number of illustrative examples. The scientific approach to the identification of social-historical determinants of radical forms of social protest implies that if something is a reason/cause of an event, then this reason/cause must be present whenever there is such an event both alone or within a complex of concomitant factors. The ‘Malthusian trap’ and demographic factors cannot be traced in all manifestations of radical mass forms of social protest in modern and contemporary history. Moreover, the ‘Malthusian trap’ and demographic pressure on the economy and social system do not always lead to mass forms of social protest. The wave of radical forms of social protest in the last decade, i.e. the so-called ‘color revolutions’, ‘Arab spring’, protest actions in France, England and the USA, once again confirms the relevance of the author’s approach and the importance of critical study of the traditional conceptions.
Sufian, Raza Sabbir; de Téramond, Guy F.; Brodsky, Stanley J.; Deur, Alexandre; Dosch, Hans Günter
2017-01-01
We present a comprehensive analysis of the spacelike nucleon electromagnetic form factors and their flavor decomposition within the framework of light-front (LF) holographic QCD (LFHQCD) We show that the inclusion of the higher Fock components |q q q q q ¯ ⟩ has a significant effect on the spin-flip elastic Pauli form factor and almost zero effect on the spin-conserving Dirac form factor. We present light-front holographic QCD results for the proton and neutron form factors at any momentum transfer range, including asymptotic predictions, and show that our results agree with the available experimental data with high accuracy. In order to correctly describe the Pauli form factor we need an admixture of a five quark state of about 30% in the proton and about 40% in the neutron. We also extract the nucleon charge and magnetic radii and perform a flavor decomposition of the nucleon electromagnetic form factors. The free parameters needed to describe the experimental nucleon form factors are very few: two parameters for the probabilities of higher Fock states for the spin-flip form factor and a phenomenological parameter r , required to account for possible SU(6) spin-flavor symmetry breaking effects in the neutron, whereas the Pauli form factors are normalized to the experimental values of the anomalous magnetic moments. The covariant spin structure for the Dirac and Pauli nucleon form factors prescribed by AdS5 semiclassical gravity incorporates the correct twist scaling behavior from hard scattering and also leads to vector dominance at low energy.
Grotkamp, S; Cibis, W; Bahemann, A; Baldus, A; Behrens, J; Nyffeler, I D; Echterhoff, W; Fialka-Moser, V; Fries, W; Fuchs, H; Gmünder, H P; Gutenbrunner, C; Keller, K; Nüchtern, E; Pöthig, D; Queri, S; Rentsch, H P; Rink, M; Schian, H-M; Schian, M; Schmitt, K; Schwarze, M; Ulrich, P; von Mittelstaedt, G; Seger, W
2014-03-01
Personal contextual factors play an essential part in the model of the International Classification of Functioning, Disability and Health (ICF). The WHO has not yet classified personal factors for global use although they impact on the functioning of persons positively or negatively. In 2010, the ICF working group of the German Society of Social Medicine and Prevention (DGSMP) presented a proposal for the classification of personal factors into 72 categories previously arranged in 6 chapters. Now a positioning paper has been added in order to stimulate a discussion about the fourth component of the ICF, to contribute towards a broader and common understanding about the nature of personal factors and to incite a dialogue among all those involved in health care as well as those people with or with-out health problems in order to gain a comprehensive perspective about a person's condition.
[Occurrence and diagnostic relevance of virulence-associated factors in Streptococcus suis].
Baums, C G; Da Silva, L M; Goethe, R; Valentin-Weigand, P
2003-09-01
Streptococcus suis (Sc. suis) can cause very different clinical entities. In contrast to Sc. suis-associated pneumonia, the induction of meningitis, septicemia, and polyarthritis by certain Sc. suis strains requires the expression of virulence factors that contribute to the invasiveness of the pathogen. In the presented study, we examined the occurrence of known virulence-associated factors in Sc. suis isolates from samples sent to the Institute of Microbiology, School of Veterinary Medicine Hannover, in order to evaluate their significance as potential virulence factors in different disease complexes in Northern Germany. The results show that (i) MRP + EF + serotype 2 and MRP* EF-serotype 9 strains are statistically significant associated with the disease complex meningitis/septicemia/arthritis and, thus, have to be considered invasive strains, (ii) serotyping alone is not sufficient for identification of virulent strains, (iii) there is a remarkable heterogeneity among pneumonia-associated Sc. suis strains and (iv) activity of haemolysin or suilysin appears to be not appropriate as virulence marker. Finally, it has to be noted that at present only half of the Sc. suis isolates from pigs with meningitis/septicemia/poyarthritis can be characterised by the detection of virulence-associated factors. Thus, the identification and characterisation of additional, serotype independent virulence factors of Sc. suis is a very important issue in future studies.
The neutron electric form factor to Q² = 1.45 (GeV/c)²
Bradley Plaster
2004-02-01
The nucleon elastic electromagnetic form factors are fundamental quantities needed for an understanding of nucleon and nuclear electromagnetic structure. The evolution of the Sachs electric and magnetic form factors with Q2, the square of the four-momentum transfer, is related to the distribution of charge and magnetization within the nucleon. High precision measurements of the nucleon form factors are essential for stringent tests of our current theoretical understanding of confinement within the nucleon. Measurements of the neutron form factors, in particular, those of the neutron electric form factor, have been notoriously difficult due to the lack of a free neutron target and the vanishing integral charge of the neutron. Indeed, a precise measurement of the neutron electric form factor has eluded experimentalists for decades; however, with the advent of high duty-factor polarized electron beam facilities, experiments employing polarization degrees of freedom have finally yielded the first precise measurements of this fundamental quantity. Following a general overview of the experimental and theoretical status of the nucleon form factors, a detailed description of an experiment designed to extract the neutron electric form factor from measurements of the neutron's recoil polarization in quasielastic 2H(e, e')1H scattering is presented. The experiment described here employed the Thomas Jefferson National Accelerator Facility's longitudinally polarized electron beam, a magnetic spectrometer for detection of the scattered electron, and a neutron polarimeter designed specifically for this experiment. Measurements were conducted at three Q2 values of 0.45, 1.13, and 1.45 (GeV/c)2, and the final results extracted from an analysis of the data acquired in this experiment are reported and compared with recent theoretical predictions for the nucleon form factors.
The neutron electric form factor to Q² = 1.45 (GeV/c)²
Plaster, Bradley [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
2004-02-01
The nucleon elastic electromagnetic form factors are fundamental quantities needed for an understanding of nucleon and nuclear electromagnetic structure. The evolution of the Sachs electric and magnetic form factors with Q^{2}, the square of the four-momentum transfer, is related to the distribution of charge and magnetization within the nucleon. High precision measurements of the nucleon form factors are essential for stringent tests of our current theoretical understanding of confinement within the nucleon. Measurements of the neutron form factors, in particular, those of the neutron electric form factor, have been notoriously difficult due to the lack of a free neutron target and the vanishing integral charge of the neutron. Indeed, a precise measurement of the neutron electric form factor has eluded experimentalists for decades; however, with the advent of high duty-factor polarized electron beam facilities, experiments employing polarization degrees of freedom have finally yielded the first precise measurements of this fundamental quantity. Following a general overview of the experimental and theoretical status of the nucleon form factors, a detailed description of an experiment designed to extract the neutron electric form factor from measurements of the neutron's recoil polarization in quasielastic 2H(e, e')1H scattering is presented. The experiment described here employed the Thomas Jefferson National Accelerator Facility's longitudinally polarized electron beam, a magnetic spectrometer for detection of the scattered electron, and a neutron polarimeter designed specifically for this experiment. Measurements were conducted at three Q^{2} values of 0.45, 1.13, and 1.45 (GeV/c)^{2}, and the final results extracted from an analysis of the data acquired in this experiment are reported and compared with recent theoretical predictions for the nucleon form factors.
Melquicedec Lozano-Posso
2016-12-01
Full Text Available This research works toward the identification of the factors that comprise the process of socialization, involvement and initial belonging of descendants in family businesses and the key relationships between them. By means of a qualitative detailed study of four cases, complemented by a quantitative survey of 274 Colombian family businesses, the authors generate a new model that takes into account both factors explored in previous research as well as others identified in this study. Findings confirm the specific dependency of each stage on the subsequent ones; socialization influences involvement, which in turn influences the belonging of the descendants to the family business, with a strong presence of factors such as knowledge, leadership, mode, timing, and motivation. Those responsible for the orientation of potential successors may examine these findings in order to optimize their preparation efforts and support of family human resources for the continuity of the business.
On the relevance of assumptions associated with classical factor analytic approaches.
Kasper, Daniel; Unlü, Ali
2013-01-01
A personal trait, for example a person's cognitive ability, represents a theoretical concept postulated to explain behavior. Interesting constructs are latent, that is, they cannot be observed. Latent variable modeling constitutes a methodology to deal with hypothetical constructs. Constructs are modeled as random variables and become components of a statistical model. As random variables, they possess a probability distribution in the population of reference. In applications, this distribution is typically assumed to be the normal distribution. The normality assumption may be reasonable in many cases, but there are situations where it cannot be justified. For example, this is true for criterion-referenced tests or for background characteristics of students in large scale assessment studies. Nevertheless, the normal procedures in combination with the classical factor analytic methods are frequently pursued, despite the effects of violating this "implicit" assumption are not clear in general. In a simulation study, we investigate whether classical factor analytic approaches can be instrumental in estimating the factorial structure and properties of the population distribution of a latent personal trait from educational test data, when violations of classical assumptions as the aforementioned are present. The results indicate that having a latent non-normal distribution clearly affects the estimation of the distribution of the factor scores and properties thereof. Thus, when the population distribution of a personal trait is assumed to be non-symmetric, we recommend avoiding those factor analytic approaches for estimation of a person's factor score, even though the number of extracted factors and the estimated loading matrix may not be strongly affected. An application to the Progress in International Reading Literacy Study (PIRLS) is given. Comments on possible implications for the Programme for International Student Assessment (PISA) complete the presentation.
Nucleon electromagnetic form factors using lattice simulations at the physical point
Alexandrou, C.; Constantinou, M.; Hadjiyiannakou, K.; Jansen, K.; Kallidonis, Ch.; Koutsou, G.; Vaquero Aviles-Casco, A.
2017-08-01
We present results for the nucleon electromagnetic form factors using an ensemble of maximally twisted mass clover-improved fermions with pion mass of about 130 MeV. We use multiple sink-source separations and three analysis methods to probe ground-state dominance. We evaluate both the connected and disconnected contributions to the nucleon matrix elements. We find that the disconnected quark loop contributions to the isoscalar matrix elements are small, giving an upper bound of up to 2% of the connected and smaller than its statistical error. We present results for the isovector and isoscalar electric and magnetic Sachs form factors and the corresponding proton and neutron form factors. By fitting the momentum dependence of the form factors to a dipole form or to the z expansion, we extract the nucleon electric and magnetic radii, as well as the magnetic moment. We compare our results to experiment as well as to other recent lattice QCD calculations.
On-shell diagrams, Graßmannians and integrability for form factors
Frassek, Rouven [Department of Mathematical Sciences, Durham University,South Road, Durham DH1 3LE (United Kingdom); Meidinger, David; Nandan, Dhritiman; Wilhelm, Matthias [Institut für Mathematik und Institut für Physik, Humboldt-Universität zu Berlin,IRIS Gebäude, Zum Großen Windkanal 6, 12489 Berlin (Germany)
2016-01-29
We apply on-shell and integrability methods that have been developed in the context of scattering amplitudes in N=4 SYM theory to tree-level form factors of this theory. Focussing on the colour-ordered super form factors of the chiral part of the stress-tensor multiplet as an example, we show how to systematically construct on-shell diagrams for these form factors with the minimal form factor as further building block in addition to the three-point amplitudes. Moreover, we obtain analytic representations in terms of Graßmannian integrals in spinor helicity, twistor and momentum twistor variables. While Yangian invariance is broken by the operator insertion, we find that the form factors are eigenstates of the integrable spin-chain transfer matrix built from the monodromy matrix that yields the Yangian generators. Constructing them via the method of R operators allows to introduce deformations that preserve the integrable structure. We finally show that the integrable properties extend to minimal tree-level form factors of generic composite operators as well as certain leading singularities of their n-point loop-level form factors.
田歌
2013-01-01
Objective To explore the relative factors which caused the extubation failure in neurological intensive care unit(NICU). Methods It was a retrospective study. 40 cases of patients who met the criteria,were brought into statistical analysis. They were admitted in NICU in
Physical interactions among plant MADS-box transcription factors and their biological relevance
Nougalli Tonaco, I.A.
2008-01-01
The biological interpretation of the genome starts from transcription, and many different signaling pathways are integrated at this level. Transcription factors play a central role in the transcription process, because they select the down-stream genes and determine their spatial and temporal
Physical interactions among plant MADS-box transcription factors and their biological relevance
Nougalli Tonaco, I.A.
2008-01-01
The biological interpretation of the genome starts from transcription, and many different signaling pathways are integrated at this level. Transcription factors play a central role in the transcription process, because they select the down-stream genes and determine their spatial and temporal expres
Kung, Pei-Tseng; Tsai, Wen-Chen; Chiou, Shang-Jyh
2012-01-01
Research that identifies the determinants of low mammography use among disabled people is scant. This study examines the determining factors related to the low usage of mammography among women with disabilities. To identify the barriers that prevent women with disabilities from participating in mammography screening can help authorities conceive…
META-ANALYSIS OF THE LIFE STYLE FACTORS RELEVANT TO ENVIRONMENTAL HAZARDS FOR THE AGING POPULATION
The goal of this U.S. Environmental Protection Agency (EPA) study is to characterize activity patterns, physiological changes, and environmental exposures for the aging population. Meta analysis was performed on more than 2000 reviewed articles to evaluate the lifestyle factors ...
Relevant Etiological Factors Involved in Human Trafficking in order to Practice Prostitution
Alexandru Boroi
2010-01-01
Human trafficking (especially women and young girls, though men count equally among the victims) are recently developed worldwide. The situation in certain regions of Central and Eastern Europe (with the opening of borders, increasing unemployment and poverty, dislocations and reducing state control structures) tend to favour the development of all forms of trafficking, especially of human trafficking forsexual exploitation. To adopt appropriate measures to prevent and combat we have to know ...
The Charge Form Factors of the Three- and Four-Body Nuclei
R. Schiavilla; V.R. Pandharipande; D.O. Riska
1990-01-01
The charge form factors of 3H, 3He, and 4He are calculated using the Monte Carlo method and variational ground-state wave functions obtained for the Argonne two-nucleon and Urbana-VII three-nucleon interactions. The model for the charge density operator contains the two-body exchange contributions of longest range. With some spread due to the uncertainty in the electromagnetic form factors of the nucleon the calculated charge form factors are in good agreement with the empirical values over the whole experimentally covered range of momentum transfer.
The omega --> pi0 gamma* and phi --> pi0 gamma* transition form factors in dispersion theory
Schneider, Sebastian P; Niecknig, Franz
2012-01-01
We calculate the omega --> pi0 gamma* and phi --> pi0 gamma* electromagnetic transition form factors based on dispersion theory, relying solely on a previous dispersive analysis of the corresponding three-pion decays and the pion vector form factor. We compare our findings to recent measurements of the omega --> pi0 mu+ mu- decay spectrum by the NA60 collaboration, and strongly encourage experimental investigation of the Okubo-Zweig-Iizuka-forbidden phi --> pi0 l+ l- decays in order to understand the strong deviations from vector-meson dominance found in these transition form factors.
On form factors of the conjugated field in the non-linear Schroedinger model
Kozlowski, K.K.
2011-05-15
Izergin-Korepin's lattice discretization of the non-linear Schroedinger model along with Oota's inverse problem provides one with determinant representations for the form factors of the lattice discretized conjugated field operator. We prove that these form factors converge, in the zero lattice spacing limit, to those of the conjugated field operator in the continuous model. We also compute the large-volume asymptotic behavior of such form factors in the continuous model. These are in particular characterized by Fredholm determinants of operators acting on closed contours. We provide a way of defining these Fredholm determinants in the case of generic paramaters. (orig.)
Grassmannians and form factors with $q^2=0$ in N=4 sym theory
Bork, L V
2016-01-01
We consider tree level form factors of operators from stress tensor operator supermultiplet with light-like operator momentum $q^2=0$. We present a conjecture for the Grassmannian integral representation both for these tree level form factors as well as for leading singularities of their loop counterparts. The presented conjecture was successfully checked by reproducing several known answers in $\\mbox{MHV}$ and $\\mbox{N}^{k-2}\\mbox{MHV}$, $k\\geq3$ sectors together with appropriate soft limits. We also discuss the cancellation of spurious poles and relations between different BCFW representations for such form factors on simple examples.
Delta and Omega electromagnetic form factors in a Dyson-Schwinger/Bethe-Salpeter approach
Diana Nicmorus, Gernot Eichmann, Reinhard Alkofer
2010-12-01
We investigate the electromagnetic form factors of the Delta and the Omega baryons within the Poincare-covariant framework of Dyson-Schwinger and Bethe-Salpeter equations. The three-quark core contributions of the form factors are evaluated by employing a quark-diquark approximation. We use a consistent setup for the quark-gluon dressing, the quark-quark bound-state kernel and the quark-photon interaction. Our predictions for the multipole form factors are compatible with available experimental data and quark-model estimates. The current-quark mass evolution of the static electromagnetic properties agrees with results provided by lattice calculations.
Pion Form Factor in Chiral Limit of Hard-Wall AdS/QCD Model
Anatoly Radyushkin; Hovhannes Grigoryan
2007-12-01
We develop a formalism to calculate form factor and charge density distribution of pion in the chiral limit using the holographic dual model of QCD with hard-wall cutoff. We introduce two conjugate pion wave functions and present analytic expressions for these functions and for the pion form factor. They allow to relate such observables as the pion decay constant and the pion charge electric radius to the values of chiral condensate and hard-wall cutoff scale. The evolution of the pion form factor to large values of the momentum transfer is discussed, and results are compared to existing experimental data.
Electromagnetic form factor via Bethe-Salpeter amplitude in Minkowski space
Carbonell, J; Mangin-Brinet, M
2008-01-01
For a relativistic system of two scalar particles, we find the Bethe-Salpeter amplitude in Minkowski space and use it to compute the electromagnetic form factor. The comparison with Euclidean space calculation shows that the Wick rotation in the form factor integral induces errors which increase with the momentum transfer Q^2. At JLab domain (Q^2=10 GeV^2/c^2), they are about 30%. Static approximation results in an additional and more significant error. On the contrary, the form factor calculated in light-front dynamics is almost indistinguishable from the Minkowski space one.
On form factors of the conjugated field in the non-linear Schroedinger model
Kozlowski, K.K.
2011-05-15
Izergin-Korepin's lattice discretization of the non-linear Schroedinger model along with Oota's inverse problem provides one with determinant representations for the form factors of the lattice discretized conjugated field operator. We prove that these form factors converge, in the zero lattice spacing limit, to those of the conjugated field operator in the continuous model. We also compute the large-volume asymptotic behavior of such form factors in the continuous model. These are in particular characterized by Fredholm determinants of operators acting on closed contours. We provide a way of defining these Fredholm determinants in the case of generic paramaters. (orig.)
Axial form factor of the nucleon in the perturbative chiral quark model
Khosonthongkee, K; Faessler, Amand; Gutsche, T; Lyubovitskij, V E; Pumsa-ard, K; Yan, Y
2004-01-01
We apply the perturbative chiral quark model (PCQM) at one loop to analyze the axial form factor of the nucleon. This chiral quark model is based on an effective Lagrangian, where baryons are described by relativistic valence quarks and a perturbative cloud of Goldstone bosons as dictated by chiral symmetry. We apply the formalism to obtain analytical expressions for the axial form factor of the nucleon, which is given in terms of fundamental parameters of low-energy pion-nucleon physics (weak pion decay constant, strong pion-nucleon form factor) and of only one model parameter (radius of the nucleonic three-quark core).
The rare decay B -> K ll form factors from lattice QCD
Bouchard, Chris; Monahan, Christopher; Na, Heechang; Shigemitsu, Junko
2013-01-01
We calculate, for the first time using unquenched lattice QCD, form factors for the rare decay B -> K ll in and beyond the Standard Model. Our lattice QCD calculation utilizes NRQCD b and HISQ light valence quarks on the MILC 2+1 asqtad ensembles. The form factor results, based on the z expansion, are valid over the full kinematic range of q^2. We construct the ratios f_0/f_+ and f_T/f_+, which are useful in constraining new physics and verifying effective theory form factor symmetry relations. We also discuss the calculation of Standard Model observables.
Samuel, Douglas B.; Mullins-Sweatt, Stephanie N.; Widiger, Thomas A.
2013-01-01
The Five-Factor Model Rating Form (FFMRF) is a one-page measure designed to provide an efficient assessment of the higher order domains of the Five Factor Model (FFM) as well as the more specific, lower order facets proposed by McCrae and Costa. Although previous research has suggested that the FFMRF's assessment of the lower order facets converge…
Burte, Emilie; Nadif, Rachel; Jacquemin, Bénédicte
2016-03-01
In this review, we identified 15 studies in children and 10 studies in adults that assessed the association between long-term exposure to air pollution and incident asthma and that conducted stratified analyses to explore potential susceptibility factors. Overall, adult never-/former smokers seem to be at higher risk of incident asthma due to air pollution. Children without atopy and children from low socioeconomic status families also seem to be at higher risk of incident asthma due to air pollution. While interaction between air pollution and genes involved in the response to oxidative stress pathways have been explored, results are somewhat inconsistent and in need of replication. To evaluate interactions, large sample sizes are necessary, and much more research, including data pooling from existing studies, is needed to further explore susceptibility factors for asthma incidence due to long-term air pollution exposure.
Mechanistic basis and clinical relevance of the role of transforming growth factor-βin cancer
Run-Long Lin; Lu-Jun Zhao
2015-01-01
Transforming growth factor-β(TGF-β) is a key factor in cancer development and progression. TGF-βcan suppress tumorigenesis by inhibiting cell cycle progression and stimulating apoptosis in early stages of cancer progression. However, TGF-βcan modulate cancer-related processes, such as cell invasion, distant metastasis, and microenvironment modiifcation that may be used by cancer cells to their advantage in late stages. Corresponding mechanisms include angiogenesis promotion, anti-tumor immunity suppression, and epithelial-to-mesenchymal transition (EMT) induction. hTe correlation between TGF-βexpression and cancer prognosis has also been extensively investigated. Results suggest that TGF-βpathway can be targeted to treat cancer;as such, the feasibility of this treatment is investigated in clinical trials.
Anthony G. Fane; Bing Wu
2012-01-01
Microorganisms in membrane bioreactors (MBRs) play important roles on degradation of organic/inorganic substances in wastewaters, while microbial deposition/growth and microbial product accumulation on membranes potentially induce membrane fouling. Generally, there is a need to characterize membrane foulants and to determine their relations to the evolution of membrane fouling in order to identify a suitable fouling control approach in MBRs. This review summarized the factors in MBRs that inf...
Peters Ansgar J
2009-05-01
Full Text Available Abstract Objective The influence hemostatitc parameters on the morphological extent and severity of coronary artery disease were studied in patients with and without DM type 2. Background It is known that patients with diabetes (DM have abnormal metabolic and hemostatic parameters Methods Of 150 consecutive patients with angiographically proven coronary artery disease 29 presented with DM. Additionally to parameters of lipid-metabolism fibrinogen, tissue-plasminogenactivator (t-PA, plasminogen-activator-inhibitor (PAI, plasmin-a-antiplasmin (PAP, prothrombin-fragment 1+2 (F1+2, thrombin-antithrombin (TAT, von-willebrand-factor (vWF, platelet factor 4 (PF4, glykomembranproteine 140 (GMP140 and the rheologic parameters plasma viscosity and red blood cell aggregation were evaluated. The extent and severity of CAD was evaluated according to the criteria of the American Heart Association. Results Patients with DM presented with a higher number of conventional risk factors as compared to non-diabetic patients. Additionally there were significant differences for F1+2, red blood cell aggregation and PAI. Diabetic patients showed a more severe extent of coronary arteriosclerosis, which also could be found more distally. A significant relationship between blood-glucose, thrombocyte-activation (vWF, endogenous fibrinolysis (PAI and the severity of CAD and a more distal location of stenoses could be found (r = 0.6, p Conclusion Patients with coronary artery disease and DM type 2 showed marked alterations of metabolic, hemostatic, fibrinolytic and rheologic parameters, which can produce a prothrombogenic state. A direct association of thrombogenic factors on coronary morphology could be shown. This can be the pathophysiologic mechanism of more severe and distal pronounced coronary atherosclerosis in these patients.
A teacher-centered exploration of the relevance of social factors to theory of mind development.
Wright, Barlow C; Mahfoud, Janina
2014-02-01
Many accounts of children's Theory of Mind (ToM) development favor a cognitive explanation, for example, in terms of mental representational improvements at or before 4 years. Here, we investigated whether social factors as rated by a child's teacher, are related to ToM development. We tested 82 children of 3-6 years on each of four ToM tasks, and their class teacher completed a social questionnaire about each child's playing behavior, sharing, talkativeness, confidence, aggressiveness and outgoingness. A measure of task memory and the child's gender were also recorded. Here, children generally passed ToM tasks after 5 years-old, but no one gender performed reliably better than the other. Teacher-rated confidence and playing behavior were correlated to ToM. But in a regression analysis, these were replaced by teacher-rated talkativeness; with age and memory given primacy in both sets of analyses. It is concluded that maturation and cognitive factors may well have primacy but social factors, facilitated during early primary education, must also be given a role in ToM development.
Clinical Relevance of Environmental Factors in the Pathogenesis of Autoimmune Thyroid Disease
Wilmar M. Wiersinga
2016-06-01
Full Text Available Genetic factors contribute for about 70% to 80% and environmental factors for about 20% to 30% to the pathogenesis of autoimmune thyroid disease (AITD. Relatives of AITD patients carry a risk to contract AITD themselves. The 5-year risk can be quantified by the so-called Thyroid Events Amsterdam-score, based on serum thyroid-stimulating hormone, thyroid peroxidase (TPO-antibodies and family history. Subjects at risk may ask what they can do to prevent development of AITD. This review summarizes what is known about modulation of exposure to environmental factors in terms of AITD prevention. To stop smoking decreases the risk on Graves disease but increases the risk on Hashimoto disease. Moderate alcohol intake provides some protection against both Graves and Hashimoto disease. Low selenium intake is associated with a higher prevalence of thyroid autoimmunity, but evidence that selenium supplementation may lower TPO antibodies and prevent subclinical hypothyroidism remains inconclusive. Low serum vitamin D levels are associated with a higher prevalence of TPO antibodies, but intervention studies with extra vitamin D have not been done yet. Stress may provoke Graves hyperthyroidism but not Hashimoto thyroiditis. Estrogen use have been linked to a lower prevalence of Graves disease. The postpartum period is associated with an increased risk of AITD. Taking together, preventive interventions to diminish the risk of AITD are few, not always feasible, and probably of limited efficacy.
Relevant Etiological Factors Involved in Human Trafficking in order to Practice Prostitution
Alexandru Boroi
2010-06-01
Full Text Available Human trafficking (especially women and young girls, though men count equally among the victims are recently developed worldwide. The situation in certain regions of Central and Eastern Europe (with the opening of borders, increasing unemployment and poverty, dislocations and reducing state control structures tend to favour the development of all forms of trafficking, especially of human trafficking forsexual exploitation. To adopt appropriate measures to prevent and combat we have to know first the causes and conditions that generate human beings trafficking. Analysis of case studies and police statistics allowed the structuring of categories of causes and conditions that generate and sustain the phenomenon of traffickingin order to practice prostitution.
Sharma, Anil K; Pallesen, Leif J; Spang, Robert J; Walden, William E
2010-08-27
FeS cluster biogenesis is an essential process in virtually all forms of life. Complex protein machineries that are conserved from bacteria through higher eukaryotes facilitate assembly of the FeS cofactor in proteins. In the last several years, significant strides have been made in our understanding of FeS cluster assembly and the functional overlap of this process with cellular iron homeostasis. This minireview summarizes the present understanding of the cytosolic iron-sulfur cluster assembly (CIA) system in eukaryotes, with a focus on information gained from studies in budding yeast and mammalian systems.
无
2001-01-01
Aims: To explore the transcription factors and related signal transduction pathways activated in the alkylating agents N-methyl-N'-nitro-N-nitrosoguanindine (MNNG) exposed cells which may involved in the mechanism of MNNG induced changes of gene expression, especially the elevation of DNA polymerase β expression and also the consequence of JNK kinase activation which were reported previously in this lab. Methods: Clontech Mercury pathway profiling system containing 8 different vectors in which a specific response element is located upstream from the SEAP-reporter gene were employed to detect the transcription factor activation in Vero cells treated with 0.2 μmol/L MNNG for 2 hours. Thoroughly, CREB phosphorylation, protein kinase A (PKA) and the cellular cAMP content were also assayed with PhosphoPlus CREB (ser-133) antibody kit, protein kinase assay kit and cAMP RIA kit respectively. Results: Among 8 different response elements, the expression of the reporter gene governed by the transcription factors CREB (cAMP response element binding protein), AP1 (activator protein 1), NF-κB (nuclear factor κ B) were elevated by 1.3, 1.4 and 1.3 times higber than control respectively. The level of activated CREB by Ser-133 phosphorylation was 2.08 times higher than control in cells treated with MNNG for 60 min, as measured by immunoblotting. The activity of CREB upstream kinase protein kinase A (PKA), which can phosphorylate CREB on ser-133 was also activated, and the activation peaked at 60 min (11.03±2.80 arbitrary units vs 0.86±0.43 of control). Also, cAMP levels were significantly raised after 60-minute-treatment, 1.52 times higher vs those in solvent control. Conclusion: In addition of previously reported JNK activation, we show here that low concentration alkylating agent MNNG can also activate the cAMP-PKA and NF-κB pathway. These in consequence induce the activation of transcription factors APl, CREB and NF-κB, which may related to the MNNG induced changes in
Ghazi, Lama; Oparil, Suzanne; Calhoun, David A; Lin, Chee Paul; Dudenbostel, Tanja
2017-05-01
Resistant hypertension, defined as blood pressure >140/90 mm Hg despite using ≥3 antihypertensive medications, is a well-recognized clinical entity. Patients with resistant hypertension are at an increased risk of cardiovascular disease compared with those with more easily controlled hypertension. Coronary heart disease mortality rates of younger adults are stagnating or on the rise. The purpose of our study was to characterize the phenotype and risk factors of younger patients with resistant hypertension, given the dearth of data on cardiovascular risk profile in this cohort. We conducted a cross-sectional analysis with predefined age groups of a large, ethnically diverse cohort of 2170 patients referred to the Hypertension Clinic at the University of Alabama at Birmingham. Patients (n=2068) met the inclusion criteria and were classified by age groups, that is, ≤40 years (12.7% of total cohort), 41 to 55 years (32.1%), 56 to 70 years (36.1%), and ≥71 years (19.1%). Patients aged ≤40 years compared with those aged ≥71 years had significantly earlier onset of hypertension (24.7±7.4 versus 55.0±14.1 years; Phypertension, younger individuals have a distinct phenotype characterized by overlapping risk factors and comorbidities, including obesity, high aldosterone, and high dietary sodium intake compared with elderly. © 2017 American Heart Association, Inc.
Some relevant factors in the consumption and non consumption of nicotine in adolescence
Alfonso Palmer
2011-01-01
Full Text Available Tobacco is the second most consumed substance among Spanish adolescents and its effects on health are well known. The aim of this study is to analyze the predictor value of different personal, family and environmental factors on tobacco consumption in the adolescent population using appropriate modelling techniques and strategies included in Data Mining. The total sample is made up of 9,300 students aged between 14 and 18 years. The adolescents anonymously answered a questionnaire which asked about the frequency of use of addictive substances as well as a series of psychosocial variables. Tobacco consumption by friends, frequency of nights out, age, production of prohibited, impulsive behaviour and the control exerted by parents bear a statistically significant influence on the number of cigarettes consumed per week and constitute risk factors for initiating consumption. Future studies should analyze, using the techniques proposed in this work and longitudinal studies, whether the tougher anti-smoking laws have been transformed into a decrease in tobacco consumption in adolescents.
Héctor Armando Durán Peralta
2010-07-01
Full Text Available The form factor must be calculated when designing ovens and mechanisms heating or cooling systems by radiation, leading to determining heat transfer by radiation between surfaces which are at different temperatures. Heat transfer texts generally deduce and show the equation for obtaining the form factor between two surfaces which exchange heat by radiation for very simple configurations, but do not show how slightly more complex geometries and configurations are calculated. Many students who have studied heat transfer have the impression that form factors are calculated without any difficulty. Other students ask why the texts do not show how to calculate the form factor for slightly more complex configurations or for those which are more real. This document tries to answer these disquietudes as well as presenting a calculation strategy for purely pedagogical ends which can be applied to more complex configurations.
Virtual photons in the pion form factors and the energy-momentum tensor
Kubis, B; Kubis, Bastian; Mei{\\ss}ner, Ulf-G.
2000-01-01
We evaluate the vector and scalar form factor of the pion in the presence of virtual photons at next-to-leading order in two-flavor chiral perturbation theory. We also consider the scalar and tensor pion form factors of the energy-momentum tensor. We find that the intrinsic electromagnetic corrections are very small for the vector and charged pion scalar form factor. The scalar radius of the neutral pion is reduced by two percent. We perform infrared regularization by considering electron-positron annihilation into pions and the decay of a light Higgs boson into a pion pair. We discuss the detector resolution dependent contributions to the various form factors and pion radii.
Constraints on the $\\omega\\pi$ form factor from analyticity and unitarity
Ananthanarayan, B; Kubis, B
2014-01-01
Motivated by the discrepancies noted recently between the theoretical calculations of the electromagnetic $\\omega\\pi$ form factor and certain experimental data, we investigate this form factor using analyticity and unitarity in a framework known as the method of unitarity bounds. We use a QCD correlator computed on the spacelike axis by operator product expansion and perturbative QCD as input, and exploit the unitarity of its spectral function, including the two-pion contribution that can be reliably calculated using high-precision data on the pion form factor, as well as narrow isoscalar vector meson states. From this information, we derive upper and lower bounds on the modulus of the form factor in the elastic region. The results provide a significant check on those obtained with standard dispersion relations, confirming the existence of a disagreement with experimental data in the region around 0.6 GeV.
Progress on charm semileptonic form factors from 2+1 flavor lattice QCD
Bailey, Jon A; Bernard, C; Bouchard, C; DeTar, C; El-Khadra, A X; Freeland, E D; Freeman, W; Gamiz, E; Gottlieb, Steven; Heller, U M; Hetrick, J E; Kronfeld, A S; Laiho, J; Levkova, L; Mackenzie, P B; Oktay, M B; Di Pierro, M; Simone, J N; Sugar, R; Toussaint, D; Van de Water, R S
2009-01-01
Lattice calculations of the form factors for the charm semileptonic decays D to K l nu and D to pi l nu provide inputs to direct determinations of the CKM matrix elements |V(cs)| and |V(cd)| and can be designed to validate calculations of the form factors for the bottom semileptonic decays B to pi l nu and B to K l l-bar. We are using Fermilab charm (bottom) quarks and asqtad staggered light quarks on the 2+1 flavor asqtad MILC ensembles to calculate the charm (bottom) form factors. We outline improvements to the previous calculation of the charm form factors and detail our progress. We expect our current round of data production to allow us to reduce the theoretical uncertainties in |V(cs)| and |V(cd)| from 10.5% and 11%, respectively, to about 7%.
Form factors for semi-leptonic and radiative decays of heavy mesons to light mesons
Stech, B
1996-01-01
To know and understand form factors of hadronic currents is of decisive importance for analysing exclusive weak decays. The ratios of different form factors of a given process depend on the relativistic spin structure of initial and final particles. It is shown --- assuming simple properties of the spectator particle --- that these ratios can entirely be expresssed in terms of particle and quark mass parameters. For quark masses large compared to the spectator mass the Isgur-Wise relations follow. The corresponding amplitudes for heavy-to-light transitions show a very similar structure. In particular, the F_0 and A_1 form factors behave again differently from the F_1, A_2, V and T_1 form factors.
Transition electromagnetic form factor in the Minkowski space Bethe-Salpeter approach
Carbonell, J
2013-01-01
Using the solutions of the Bethe-Salpeter equation in Minkowski space for bound and scattering states found in previous works, we calculate the transition electromagnetic form factor describing the electro-disintegration of a bound system.
Scalar and vector form factors of the in-medium nucleon
Saitô, K
2003-01-01
Using the quark-meson coupling model, we calculate the form factors at sigma- and omega-nucleon strong-interaction vertices in nuclear matter. The Peierls-Yoccoz projection technique is used to take account of center of mass and recoil corrections. We also apply the Lorentz contraction to the internal quark wave function. The form factors are reduced by the nuclear medium relative to those in vacuum. At normal nuclear matter density and Q^2 = 1 GeV^2, the reduction rate in the scalar form factor is about 15%, which is almost identical to that in the vector one. We parameterize the ratios of the form factors in symmetric nuclear matter to those in vacuum as a function of nuclear density and momentum transfer.
New Precision Limit on the Strange Vector Form Factors of the Proton
Ahmed, Z; Aniol, K A; Armstrong, D S; Arrington, J; Baturin, P; Bellini, V; Benesch, J; Beminiwattha, R; Benmokhtar, F; Canan, M; Camsonne, A; Cates, G D; Chen, J -P; Chudakov, E; Cisbani, E; Dalton, M M; de Jager, C W; De Leo, R; Deconinck, W; Decowski, P; Deng, X; Deur, A; Dutta, C; Franklin, G B; Friend, M; Frullani, S; Garibaldi, F; Giusa, A; Glamazdin, A; Golge, S; Grimm, K; Hansen, O; Higinbotham, D W; Holmes, R; Holmstrom, T; Huang, J; Huang, M; Hyde, C E; Jen, C M; Jin, G; Jones, D; Kang, H; King, P; Kowalski, S; Kumar, K S; Lee, J H; LeRose, J J; Liyanage, N; Long, E; McNulty, D; Margaziotis, D; Meddi, F; Meekins, D G; Mercado, L; Meziani, Z -E; Michaels, R; Munoz-Camacho, C; Mihovilovic, M; Muangma, N; Myers, K E; Nanda, S; Narayan, A; Nelyubin, V; Nuruzzaman,; Oh, Y; Pan, K; Parno, D; Paschke, K D; Phillips, S K; Qian, X; Qiang, Y; Quinn, B; Rakhman, A; Reimer, P E; Rider, K; Riordan, S; Roche, J; Rubin, J; Russo, G; Saenboonruang, K; Saha, A; Sawatzky, B; Silwal, R; Sirca, S; Souder, P A; Sperduto, M; Subedi, R; Suleiman, R; Sulkosky, V; Sutera, C M; Tobias, W A; Urciuoli, G M; Waidyawansa, B; Wang, D; Wexler, J; Wilson, R; Wojtsekhowski, B; Zhan, X; Yan, X; Yao, H; Ye, L; Zhao, B; Zheng, X
2011-01-01
The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624 GeV and beam energy E =3.48 GeV to be A_PV = -23.80 +/- 0.78 (stat) +/- 0.36 (syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors G_E^s + 0.517 G_M^s = 0.003 +/- 0.010 (stat) +/- 0.004 (syst) +/- 0.009 (ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.
$\\pi^0\\to\\gamma^*\\gamma$ transition form factor within Light Front Quark Model
Lih, Chong-Chung
2012-01-01
We study the transition form factor of $\\pi^0\\to\\gamma^* \\gamma$ as a function of the momentum transfer $Q^2$ within the light-front quark model (LFQM). We compare our result with the experimental data by BaBar as well as other calculations based on the LFQM in the literature. We show that our predicted form factor fits well with the experimental data, particularly those at the large $Q^2$ region.
Study of pesudoscalar transition form factors within light front quark model
Geng, Chao-Qiang
2012-01-01
We study the transition form factors of the pesudoscalar mesons ($\\pi,\\eta$ and $\\eta^{\\prime}$) as functions of the momentum transfer $Q^2$ within the light-front quark model. We compare our results with the recent experimental data by CELLO, CLEO, BaBar and Belle. By considering the possible uncertainties from the quark masses, we illustrate that our predicted form factors can fit with all the data, including those at the large $Q^2$ regions.
Nucleon-to-Delta axial transition form factors in relativistic baryon chiral perturbation theory
Geng, L S; Alvarez-Ruso, L; Vacas, M J Vicente
2008-01-01
We report a theoretical study of the axial Nucleon to Delta(1232) ($N\\to\\Delta$) transition form factors up to one-loop order in relativistic baryon chiral perturbation theory. We adopt a formalism in which the $\\Delta$ couplings obey the spin-3/2 gauge symmetry and, therefore, decouple the unphysical spin-1/2 fields. We compare the results with phenomenological form factors obtained from neutrino bubble chamber data and in quark models.
A Form Factor Model for Exclusive B- and D-Decays
Stech, B
1996-01-01
An explicit model is presented which gives the momentum transfer-dependent ratios of form factors of hadronic currents. For the unknown Isgur-Wise function and its generalization for transitions to light particles a simple phenomenological Ansatz is added. The model allows a calculation of all form factors in terms of mass parameters only. It is tested by comparison with experimental data, QCD sum rules and lattice calculations.
von Hippel, G M; Djukanovic, D; Hua, J; Jäger, B; Junnarkar, P; Meyer, H B; Rae, T D; Wittig, H
2014-01-01
We study the ability of a variety of fitting techniques to extract the ground state matrix elements of the vector current from ratios of nucleon three- and two-point functions that contain contaminations from excited states. Extending our high-statistics study of nucleon form factors, we are able to demonstrate that the treatment of excited-state contributions in conjunction with approaching the physical pion mass has a significant impact on the $Q^2$-dependence of the form factors.
Constraints on the $K_{l_{3}}$ form factors from analyticity and unitarity
Gauhar Abbas; B Ananthanarayan; Irinel Caprini; I Sentitemsu Imsong
2012-10-01
The $K $ form factors are investigated at low energies by the method of unitarity bounds adapted so as to include information on the phase and modulus along the elastic region of the unitarity cut. Using as input the values of the form factors at = 0, and at the Callan–Treiman point in the scalar case, stringent constraints are obtained on the slope and curvature parameters of the Taylor expansion at the origin.
Li, Hao-Song; Chen, Xiao-Lin; Deng, Wei-Zhen; Zhu, Shi-Lin
2016-01-01
We have systematically investigated the magnetic moments and magnetic form factors of the decuplet baryons to the next-to-next-leading order in the framework of the heavy baryon chiral perturbation theory. Our calculation includes the contributions from both the intermediate decuplet and octet baryon states in the loops. We also calculate the charge and magnetic dipole form factors of the decuplet baryons. Our results may be useful to the chiral extrapolation of the lattice simulations of the decuplet electromagnetic properties.
[Analysis of the relevant factors for recurrent sudden sensorineural hearing loss].
Liang, H; Zhong, S X
2016-09-07
Objective: To investigate the possible factors related to recurrence and prognosis of sudden sensorineural hearing loss(SSNHL). Methods: Four hundred and ninety-five patients with unilateral sudden sensorineural hearing loss between January 2013 to April 2014 were analyzed retrospectively(34 patients lost to follow-up with a dropout rate of 6.87%). Twenty of the 495 patients were diagnosed as recurrent SSNHL and treated again in the same hospital. The data of the patients were summarized to analyze the related factors which might influence the recurrence and prognosis of SSNHL. Results: In the 20 patients with recurrent SSNHL, 19 had the second attack in same ear as the first attack, and the other one had in both ears. There were seven male patients, and thirteen female patients. Patients ranged in age from 24 to 77years, with a median age of 39.5 years. Types of hearing loss: low frequency in eight patients, high frequency in two patients, flat frequency in eight patients, total deafness in two patients, the types of the second attack in 17 patients were same as the first attack, only one patient was changed from total deafness to flat frequency, one case was changed from flat frequency to high frequency, one case changed from flat frequency to total deafness. The intervals between of the first attack time and the second attack time were 1-36 months with the median time of 3.5 months. After systemic oral and (or) transtympanic steroid treatment, recovered in three cases, effective in three cases and 14 cases invalid, the cure rate was 15%, and the total effective rate was 30%. There were statistically significant differences in the recovery rate(χ(2)=8.640, Phearing loss except low frequency type, the treatment effect was invalid. The patients with hearing loss at low frequency had the best outcomes. The total effective rates were significant different between patients younger and old than 34 years old(P0.05). The recurrence rates of patients with various types
Larrainzar-Coghen, T; Rodriguez-Pardo, D; Puig-Asensio, M; Rodríguez, V; Ferrer, C; Bartolomé, R; Pigrau, C; Fernández-Hidalgo, N; Pumarola, T; Almirante, B
2016-03-01
Therapy for recurrent Clostridium difficile-associated diarrhea (CDAD) is challenging. We evaluated the frequency, associated risk factors, and prognosis of first CDAD recurrences. Prospective cohort study of all consecutive cases of primary CDAD diagnosed in a university hospital from January 2006 to June 2013. Recurrent infection was defined as reappearance of symptoms within 8 weeks of the primary diagnosis, provided that CDAD symptoms had previously resolved and a new toxin test was positive. Predictors of a first episode of recurrent CDAD were determined by logistic regression analysis. In total, 502 patients (51.6 % men) with a mean age of 62.3 years (SD 18.5) had CDAD; 379 (76 %) were cured, 61 (12 %) had a first recurrence, 52 (10 %) died within 30 days of the CDAD diagnosis, nine (2 %) required colectomy, and one was lost to follow-up. Among the 61 patients with a first recurrence, 36 (59.3 %) were cured, 15 (23.7 %) had a second recurrence, nine (15.3 %) died, and one (1.7 %) required colectomy. On multivariate analysis, age older than 65 years (OR 2.04; 95 % CI, 1.14-3.68; P predictors of a first recurrence. A risk score was developed for first CDAD recurrence using the predictive factors and selected biological variables. In our CDAD cohort, 12 % of patients had a first recurrence of this disease, in which the prognosis was less favorable than that of the primary episode, as it heralded a higher risk of additional recurrences. Patient age and enteral nutrition were predictors of a first recurrence.
Proton electromagnetic form factors: present status and future perspectives at PANDA
Tomasi-Gustafsson E.
2015-01-01
Full Text Available Data and models on electromagnetic proton form factors are reviewed, highlighting the contribution foreseen by the PANDA collaboration. Electromagnetic hadron form factors contain essential information on the internal structure of hadrons. Precise and surprising data have been obtained at electron accelerators, applying the polarization method in electron-proton elastic scattering. At electron-positron colliders, using initial state radiation, BABAR measured proton time-like form factors in a wide time-like kinematical region and the BESIII collaboration will measure very precisely proton and neutron form factors in the threshold region. In the next future an antiproton beam with momentum up to 15 GeV/c will be available at FAIR (Darmstadt. Measurements of the reaction p̅ + p → e+ + e− by the PANDA collaboration will contribute to the individual determination of electric and magnetic form factors in the time-like region of momentum transfer squared, as well as to their first determination in the unphysical region (below the kinematical threshold, through the reaction p̅ + p → e+ + e− + π0. From the discussion on feasibility studies at PANDA, we focus on the consequences of such measurements in view of an unified description of form factors in the full kinematical region. We present models which have the necessary analytical requirements and apply to the data in the whole kinematical region.
Proton electromagnetic form factors: present status and future perspectives at PANDA
Tomasi-Gustafsson, E.
2015-05-01
Data and models on electromagnetic proton form factors are reviewed, highlighting the contribution foreseen by the PANDA collaboration. Electromagnetic hadron form factors contain essential information on the internal structure of hadrons. Precise and surprising data have been obtained at electron accelerators, applying the polarization method in electron-proton elastic scattering. At electron-positron colliders, using initial state radiation, BABAR measured proton time-like form factors in a wide time-like kinematical region and the BESIII collaboration will measure very precisely proton and neutron form factors in the threshold region. In the next future an antiproton beam with momentum up to 15 GeV/c will be available at FAIR (Darmstadt). Measurements of the reaction p̅ + p → e+ + e- by the PANDA collaboration will contribute to the individual determination of electric and magnetic form factors in the time-like region of momentum transfer squared, as well as to their first determination in the unphysical region (below the kinematical threshold), through the reaction p̅ + p → e+ + e- + π0. From the discussion on feasibility studies at PANDA, we focus on the consequences of such measurements in view of an unified description of form factors in the full kinematical region. We present models which have the necessary analytical requirements and apply to the data in the whole kinematical region.
Mixed-state form factors of U(1) twist fields in the Dirac theory
Chen, Yixiong
2016-08-01
Using the ‘Liouville space’ (the space of operators) of the massive Dirac theory, we define mixed-state form factors of U(1) twist fields. We consider mixed states with density matrices diagonal in the asymptotic particle basis. This includes the thermal Gibbs state as well as all generalized Gibbs ensembles of the Dirac theory. When the mixed state is specialized to a thermal Gibbs state, using a Riemann-Hilbert problem and low-temperature expansion, we obtain finite-temperature form factors of U(1) twist fields. We then propose the expression for form factors of U(1) twist fields in general diagonal mixed states. We verify that these form factors satisfy a system of nonlinear functional differential equations, which is derived from the trace definition of mixed-state form factors. At last, under weak analytic conditions on the eigenvalues of the density matrix, we write down the large distance form factor expansions of two-point correlation functions of these twist fields. Using the relation between the Dirac and Ising models, this provides the large-distance expansion of the Rényi entropy (for integer Rényi parameter) in the Ising model in diagonal mixed states.
Huber, Garth; Blok, Henk; Horn, Tanja; Beise, Elizabeth; Gaskell, David; Mack, David; Tadevosyan, Vardan; Volmer, Jochen; Abbott, David; Aniol, Konrad; Anklin, Heinz; Armstrong, Christopher; Arrington, John; Assamagan, Ketevi; Avery, Steven; Baker, O.; Barrett, Robert; Bochna, Christopher; Boeglin, Werner; Brash, Edward; Breuer, Herbert; Chang, C.; Chang, C.C.; Chant, Nicholas; Christy, Michael; Dunne, James; Eden, Thomas; Ent, Rolf; Fenker, Benjamin; Gibson, Edward; Gilman, Ronald; Gustafsson, Kenneth; Hinton, Wendy; Holt, Roy; Jackson, Harold; uk Jin, Seong; Jones, Mark; Keppel, Cynthia; Kim, pyunghun; Kim, Wooyoung; King, Paul; Klein, Andreas; Koltenuk, Douglas; Kovaltchouk, Vitali; Liang, Meihua; Liu, Jinghua; Lolos, George; Lung, Allison; Margaziotis, Demetrius; Markowitz, Pete; Matsumura, Akihiko; McKee, David; Meekins, David; Mitchell, Joseph; Miyoshi, Toshinobu; Mkrtchyan, Hamlet; Mueller, Robert; Niculescu, Gabriel; Niculescu, Maria-Ioana; Okayasu, Yuichi; Pentchev, Lubomir; Perdrisat, Charles; Pitz, David; Potterveld, David; Punjabi, Vina; Qin, Liming; Reimer, Paul; Reinhold, Joerg; Roche, Julie; Roos, Philip; Sarty, Adam; Shin, Ilkyoung; Smith, Gregory; Stepanyan, Stepan; Tang, Liguang; Tvaskis, Vladas; van der Meer, Rob; Vansyoc, Kelley; Van Westrum, Derek; Vidakovic, Sandra; Vulcan, William; Warren, Glen; Wood, Stephen; Xu, Chen; Yan, Chen; Zhao, Wenxia; Zheng, Xiaochao; Zihlmann, Benedikt
2008-10-01
DOI: http://dx.doi.org/10.1103/PhysRevC.78.045203
The charged pion form factor, Fpi(Q2), is an important quantity that can be used to advance our knowledge of hadronic structure. However, the extraction of Fpi from data requires a model of the 1H(e,e'pi+)n reaction and thus is inherently model dependent. Therefore, a detailed description of the extraction of the charged pion form factor from electroproduction data obtained recently at Jefferson Lab is presented, with particular focus given to the dominant uncertainties in this procedure. Results for Fpi are presented for Q2=0.60-2.45 GeV2. Above Q2=1.5 GeV2, the Fpi values are systematically below the monopole parametrization that describes the low Q2 data used to determine the pion charge radius. The pion form factor can be calculated in a wide variety of theoretical approaches, and the experimental results are compared to a number of calculations. This comparison is helpful in understanding the role of soft versus hard c
Huber, G M; Horn, T; Beise, E J; Gaskell, D; Mack, D J; Tadevosyan, V; Volmer, J; Abbott, D; Aniol, K; Anklin, H; Armstrong, C; Arrington, J; Assamagan, K; Avery, S; Baker, O K; Barrett, B; Bochna, C; Boeglin, W; Brash, E J; Breuer, H; Chang, C C; Chant, N; Christy, M E; Dunne, J; Eden, T; Ent, R; Gibson, E; Gilman, R; Gustafsson, K; Hinton, W; Holt, R J; Jackson, H; Jin, S; Jones, M K; Keppel, C E; Kim, P H; Kim, W; King, P M; Klein, A; Koltenuk, D; Kovaltchouk, V; Kiang, M; Liu, J; Lolos, G J; Lung, A; Margaziotis, D J; Markowitz, P; Matsumura, A; McKee, D; Meekins, D; Mitchell, J; Miyoshi, T; Mkrtchyan, H; Müller, B; Niculescu, G; Niculescu, I; Okayasu, Y; Pentchev, L; Perdrisat, C; Pitz, D; Potterveld, D; Punjabi, V; Qin, L M; Reimer, P; Reinhold, J; Roche, J; Roos, P G; Sarty, A; Shin, I K; Smith, G R; Stepanyan, S; Tang, L G; Tvaskis, V; Van der Meer, R L J; Vansyoc, K; Van Westrum, D; Vidakovic, S; Vulcan, W; Warren, G; Wood, S A; Xu, C; Yan, C; Zhao, W -X; Zheng, X; Zihlmann, B
2008-01-01
The charged pion form factor, Fpi(Q^2), is an important quantity which can be used to advance our knowledge of hadronic structure. However, the extraction of Fpi from data requires a model of the 1H(e,e'pi+)n reaction, and thus is inherently model dependent. Therefore, a detailed description of the extraction of the charged pion form factor from electroproduction data obtained recently at Jefferson Lab is presented, with particular focus given to the dominant uncertainties in this procedure. Results for Fpi are presented for Q^2=0.60-2.45 GeV^2. Above Q^2=1.5 GeV^2, the Fpi values are systematically below the monopole parameterization that describes the low Q^2 data used to determine the pion charge radius. The pion form factor can be calculated in a wide variety of theoretical approaches, and the experimental results are compared to a number of calculations. This comparison is helpful in understanding the role of soft versus hard contributions to hadronic structure in the intermediate Q^2 regime.
Theys, T E; Geeraerd, A H; Devlieghere, F; Van Impe, J F
2010-04-01
Several studies have shown that food structure causes slower growth rates and narrower growth boundaries of bacteria compared to laboratory media. In predictive microbiology, both a(w) or corresponding solute concentration (mainly NaCl) have been used as a growth influencing factor for kinetic models or growth/no growth interface models. The majority of these models have been based on data generated in liquid broth media with NaCl as the predominant a(w) influencing solute. However, in complex food systems, other a(w) influencing components might be present, next to NaCl. In this study, the growth rate of Salmonella typhimurium was studied in the growth region and the growth/no growth response was tested in Tryptic Soy Broth at 20 degrees C at varying gelatin concentration (0, 10, 50 g L(-1) gelatin), pH (3.25-5.5) and water activity (a(w)) (0.929-0.996). From the viewpoint of water activity, the results suggest that NaCl is the main a(w) affecting compound. However, gelatin seemed to have an effect on medium a(w) too. Moreover, there is also an interaction effect between NaCl and gelatin. From the microbial viewpoint, the results confirmed that the a(w) decreasing effect of gelatin is less harmful to cells than the effect of Na(+) ions. The unexpected shift of the growth/no growth interface to more severe conditions when going from a liquid medium to a medium with 10 g L(-1) gelatin is more pronounced when formulating the models in terms of a(w) than in terms of NaCl concentrations. At 50 g L(-1) gelatin, the model factored with NaCl concentration shifts to milder conditions (concordant to literature results) while the model with a(w) indicates a further shift to more severe conditions, which is due to the water activity lowering effect of gelatin and the interaction between gelatin and NaCl. The results suggest that solute concentration should be used instead of a(w), both for kinetic models in the growth region and for growth/no growth interface models, if the
Suri, D; Vaidya, V A
2013-06-01
Glucocorticoids serve as key stress response hormones that facilitate stress coping. However, sustained glucocorticoid exposure is associated with adverse consequences on the brain, in particular within the hippocampus. Chronic glucocorticoid exposure evokes neuronal cell damage and dendritic atrophy, reduces hippocampal neurogenesis and impairs synaptic plasticity. Glucocorticoids also alter expression and signaling of the neurotrophin, brain-derived neurotrophic factor (BDNF). Since BDNF is known to promote neuroplasticity, enhance cell survival, increase hippocampal neurogenesis and cellular excitability, it has been hypothesized that specific adverse effects of glucocorticoids may be mediated by attenuating BDNF expression and signaling. The purpose of this review is to summarize the current state of literature examining the influence of glucocorticoids on BDNF, and to address whether specific effects of glucocorticoids arise through perturbation of BDNF signaling. We integrate evidence of glucocorticoid regulation of BDNF at multiple levels, spanning from the well-documented glucocorticoid-induced changes in BDNF mRNA to studies examining alterations in BDNF receptor-mediated signaling. Further, we delineate potential lines of future investigation to address hitherto unexplored aspects of the influence of glucocorticoids on BDNF. Finally, we discuss the current understanding of the contribution of BDNF to the modulation of structural and functional plasticity by glucocorticoids, in particular in the context of the hippocampus. Understanding the mechanistic crosstalk between glucocorticoids and BDNF holds promise for the identification of potential therapeutic targets for disorders associated with the dysfunction of stress hormone pathways.
Giorgio Falaschi
2013-09-01
Full Text Available Ultrasound guided foam sclerotherapy (UGFS constitutes a valid ablative treatment for superficial vein diseases for the great saphenous vein (GSV, but no standardized protocol for its execution has yet been defined. Different variable factors involved in this procedure influence the final outcome and clinical results. The aim of our study was to analyze the respective influence on efficacy and side effects of three variable factors (foam volume, foam concentration, and contact time between the foam and the endothelium for UGFS procedures for GSV insufficiency in order to select the best protocol for treatment. A retrospective analysis was made of UGFS procedures (190 patients, 201 legs performed for GSV insufficiency in our institute from January 2007 to January 2010. All great saphenous veins included in our study exhibited a trans-ostial reflux and caliber range was 7-11 mm. In all cases, foam was prepared according to the Tessari method, using polidocanol (POL and a gas mixture of CO2 (70% and filtered room air (30%, in a proportion of 1:4. A single injection procedure in the GSV was performed under Doppler ultrasound guidance at mid to lower third of the thigh. Legs were randomly assigned to one of three different treatment protocols: - Group A (71 legs: POL 3%, mean foam volume 4.5 cc, intermittent groin pressure 5 min, supine bed rest 10 min; - Group B (61 legs: POL 2%, mean foam volume 9 cc, intermittent groin pressure 5 min, supine bed rest 10 min; - Group C (69 legs: POL 2%, mean foam volume 9 cc, continuous groin pressure 5 min followed by intermittent groin pressure 5 min, continuous leg compression 5 min, supine bed rest 10 min. Efficacy of treatment and occurrence of side effects were evaluated in each group at two weeks and again at two years after the procedure and the cumulative results compared. Analysis of outcomes did not show any significant difference between the complete obliteration rate (P=0.825 or occurrence of local
Single-Spin Polarization Effects and the Determination of Timelike Proton Form Factors
Brodsky, S
2003-10-24
We show that measurements of the proton's polarization in e{sup +}e{sup -} {yields} p{bar p} strongly discriminate between analytic forms of models which fit the proton form factors in the spacelike region. In particular, the single-spin asymmetry normal to the scattering plane measures the relative phase difference between the timelike G{sub E} and G{sub M} form factors. The expected proton polarization in the timelike region is large, of order of several tens of percent.
Pion charge form factor and constraints from space-time translations
Desplanques, Bertrand
2010-01-01
The role of Poincar\\'e covariant space-time translations is investigated in the case of a relativistic quantum mechanics approach to the pion charge form factor. It is shown that the related constraints are generally inconsistent with the assumption of a single-particle current, which is most often referred to. The only exception is the front-form approach with $q^+=0$. How accounting for the related constraints, as well as restoring the equivalence of different RQM approaches in estimating form factors, is discussed. Some extensions of this work and, in particular, the relationship with a dispersion-relation approach, are presented. Conclusions relative to the underlying dynamics are given.
The Potential Risk Factors Relevant to Lateral Epicondylitis by Wrist Coupling Posture.
Su-Ya Lee
Full Text Available The use of awkward wrist postures and unskilled techniques might induce lateral epicondylitis. This study thus investigated the effects of wrist deviation combined with extension and movement velocity on the dynamic performances of the wrist muscles during the coupling posture via a custom-made bi-planar isokinetic dynamometer. Thirty subjects were recruited to perform the isokinetic testing. We measured the muscle strengths and activities for the wrist extensors and flexors during concentric and eccentric contractions at three movement velocities, 30°s-1, 90°s-1, and 180°s-1, combined with three wrist postures, neutral position (NP, radial deviation (RD, and ulnar deviation (UD. The root mean square (RMS of the electromyographic signal in the extensor digitorum communis (EDC, normalized peak torque of extensors, and ratio of normalized peak torque between wrist extensors and flexors, were all greater in the NP than RD and UD in both contractions. The ratio of RMS between EDC and flexor digitorum superficialis (FDS had a significantly greater value in RD than UD during the concentric contraction. The EDC showed significantly higher activity at the fast velocity in both contractions. Nevertheless, a significantly higher RMS of the electromyographic signal between EDC and FDS and the ratio of strength between wrist extensors and flexors were found at slow velocity in both contractions. The wrist deviation combined with extension and movement velocity of the wrist joint should thus be considered as influential factors which might alter the dynamic performances, and may result in further injury of the elbow joint.
The Potential Risk Factors Relevant to Lateral Epicondylitis by Wrist Coupling Posture
Lee, Su-Ya; Chieh, Hsiao-Feng; Lin, Chien-Ju; Jou, I-Ming; Kuo, Li-Chieh; Su, Fong-Chin
2016-01-01
The use of awkward wrist postures and unskilled techniques might induce lateral epicondylitis. This study thus investigated the effects of wrist deviation combined with extension and movement velocity on the dynamic performances of the wrist muscles during the coupling posture via a custom-made bi-planar isokinetic dynamometer. Thirty subjects were recruited to perform the isokinetic testing. We measured the muscle strengths and activities for the wrist extensors and flexors during concentric and eccentric contractions at three movement velocities, 30°s-1, 90°s-1, and 180°s-1, combined with three wrist postures, neutral position (NP), radial deviation (RD), and ulnar deviation (UD). The root mean square (RMS) of the electromyographic signal in the extensor digitorum communis (EDC), normalized peak torque of extensors, and ratio of normalized peak torque between wrist extensors and flexors, were all greater in the NP than RD and UD in both contractions. The ratio of RMS between EDC and flexor digitorum superficialis (FDS) had a significantly greater value in RD than UD during the concentric contraction. The EDC showed significantly higher activity at the fast velocity in both contractions. Nevertheless, a significantly higher RMS of the electromyographic signal between EDC and FDS and the ratio of strength between wrist extensors and flexors were found at slow velocity in both contractions. The wrist deviation combined with extension and movement velocity of the wrist joint should thus be considered as influential factors which might alter the dynamic performances, and may result in further injury of the elbow joint. PMID:27171198
The MnSOD Ala16Val SNP: relevance to human diseases and interaction with environmental factors.
Bresciani, G; Cruz, I B M; de Paz, J A; Cuevas, M J; González-Gallego, J
2013-10-01
The relevance of reactive oxygen species (ROS) production relies on the dual role shown by these molecules in aerobes. ROS are known to modulate several physiological phenomena, such as immune response and cell growth and differentiation; on the other hand, uncontrolled ROS production may cause important tissue and cell damage, such as deoxyribonucleic acid oxidation, lipid peroxidation, and protein carbonylation. The manganese superoxide dismutase (MnSOD) antioxidant enzyme affords the major defense against ROS within the mitochondria, which is considered the main ROS production locus in aerobes. Structural and/or functional single nucleotide polymorphisms (SNP) within the MnSOD encoding gene may be relevant for ROS detoxification. Specifically, the MnSOD Ala16Val SNP has been shown to alter the enzyme localization and mitochondrial transportation, affecting the redox status balance. Oxidative stress may contribute to the development of type 2 diabetes, cardiovascular diseases, various inflammatory conditions, or cancer. The Ala16Val MnSOD SNP has been associated with these and other chronic diseases; however, inconsistent findings between studies have made difficult drawing definitive conclusions. Environmental factors, such as dietary antioxidant intake and exercise have been shown to affect ROS metabolism through antioxidant enzyme regulation and may contribute to explain inconsistencies in the literature. Nevertheless, whether environmental factors may be associated to the Ala16Val genotypes in human diseases still needs to be clarified.
Massen, S E; Grypeos, M E
1995-01-01
We investigate the effects of fluctuations of the nuclear surface on the harmonic oscillator elastic charge form factor of light nuclei, while simultaneously approximating the short-range correlations through a Jastrow correlation ~factor. Inclusion of surface-fluctuation effects within this description, by truncating the cluster expansion at the two-body part, is found to improve somewhat the fit to the elastic charge form-factor of ^{16}O and ^{40}Ca. However, the convergence of the cluster expansion is expected to deteriorate. An additional finding is that the surface-fluctuation correlations produce a drastic change in the asymptotic behavior of the point-proton form factor, which now falls off quite slowly (i.e. as const. \\cdot q^{-4}) at large values of the momentum transfer q.
Boobis, Alan; Flari, Villie; Gosling, John Paul; Hart, Andy; Craig, Peter; Rushton, Lesley; Idahosa-Taylor, Ehi
2013-07-01
The general approach to risk assessment of genotoxic carcinogens has been to advise reduction of exposure to "as low as reasonably achievable/practicable" (ALARA/P). However, whilst this remains the preferred risk management option, it does not provide guidance on the urgency or extent of risk management actions necessary. To address this, the "Margin of Exposure" (MOE) approach has been proposed. The MOE is the ratio between the point of departure for carcinogenesis and estimated human exposure. However, interpretation of the MOE requires implicit or explicit consideration of the shape of the dose-response curve at human relevant exposures. In a structured elicitation exercise, we captured expert opinion on available scientific evidence for low dose-response relationships for genotoxic carcinogens. This allowed assessment of: available evidence for the nature of dose-response relationships at human relevant exposures; the generality of judgments about such dose-response relationships; uncertainties affecting judgments on the nature of such dose-response relationships; and whether this last should differ for different classes of genotoxic carcinogens. Elicitation results reflected the variability in experts' views on the form of the dose-response curve for low dose exposure and major sources of uncertainty affecting the assumption of a linear relationship.
Seyedeh Azam Sajadi
2017-07-01
Full Text Available Background: Family caregivers are considered as hidden patients experiencing physical and mental disorders. This affects the quality of not only their lives but also the health care provided to patients.This study aimed to investigate the quality of life (QOL and its related factors among the caregivers of patients undergoing hemodialysis. Methods: This systematic review was conducted based on the eight-step guidelines presented by the York University. The databases relevant to the medical field including Nursing and Allied Health, Web of Science, Scopus, Pubmed, Embase, PsycINFO and Psychology Library were used. Finally, 12 articles observing the inclusion criteria and with regard to the research questions were found. The data obtained from these articles were summarized, classified, and analyzed. Results: QOL among Family Caregivers of Patients on Hemodialysis is low, compared to the general population; however, their QOL is higher than the patients under their care. Factors relevant to the QOL for caregivers including age, gender, perceived social support, perceived burden of care, affliction with other diseases (lupus, hypertension, hypothyroidism and depression, intellectual understanding of the limitations of the patient’s disease in their daily life, employment of adaptation strategies, better marital relationships, accepting self and family relationship with the patient (mother and wife. Furthermore, the factors associated with care takers affecting the quality of caregivers’ lives were age, QOL and the type of treatment. Conclusions: Caregivers of patients undergoing hemodialysis enjoyed low QOL. Since there is a direct relationship between family caregivers’ quality and patients’ QOL, health care system and health policy makers should pay more attention to family caregivers.
A combined study of the pion's static properties and form factors
El-Bennich, B; Frederico, T
2012-01-01
We study consistently the pion's static observables and the elastic and \\gamma*\\gamma -> \\pi^0 transition form factors within a light-front model. Consistency requires that all calculations are performed within a given model with the same and single adjusted length or mass-scale parameter of the associated pion bound-state wave function. Our results agree well with all extent data including recent Belle data on the \\gamma*\\gamma -> \\pi^0 form factor at large q^2, yet the BaBar data on this transition form factor resists a sensible comparison. We relax the initial constraint on the bound-state wave function and show the BaBar data can partially be accommodated. This, however, comes at the cost of a hard elastic form factor not in agreement with experiment. Moreover, the pion charge radius is about 40% smaller than its experimentally determined value. It is argued that a decreasing charge radius produces an ever harder form factor with a bound-state amplitude difficultly reconcilable with soft QCD. We also disc...
Feasibility studies of time-like proton electromagnetic form factors at PANDA-FAIR
Dbeyssi, Alaa; Capozza, Luigi; Deiseroth, Malte; Froehlich, Bertold; Khaneft, Dmitry; Mora Espi, Maria Carmen; Noll, Oliver; Rodriguez Pineiro, David; Valente, Roserio; Zambrana, Manuel; Zimmermann, Iris [Helmholtz-Institut Mainz, Mainz (Germany); Maas, Frank [Helmholtz-Institut Mainz, Mainz (Germany); Institute of Nuclear Physics, Mainz (Germany); PRISMA Cluster of Excellence, Mainz (Germany); Marchand, Dominique; Tomasi-Gustafsson, Egle; Wang, Ying [Institut de Physique Nucleaire, Orsay (France); Collaboration: PANDA-Collaboration
2015-07-01
Electromagnetic form factors are fundamental quantities which describe the intrinsic electric and magnetic distributions of hadrons. Time-like proton form factors are experimentally accessible through the annihilation processes anti p+p <-> e{sup +}+e{sup -}. Their measurement in the time-like region had been limited by the low statistics achieved by the experiments. This contribution reports on the results of Monte Carlo simulations for future measurements of electromagnetic proton form factors at PANDA (antiProton ANnihilation at DArmstadt). In frame of the PANDARoot software, the statistical precision at which the proton form factors will be determined is estimated. The signal (anti p+p → e{sup +}+e{sup -}) identification and the suppression of the main background process (anti p+p → π{sup +}+π{sup -}) are studied. Different methods have been used and/or developed to generate and analyse the processes of interest. The results show that time-like proton form factors will be measured at PANDA with unprecedented statistical accuracy.
Duda, G; Kemper, A; Duda, Gintaras; Gondolo, Paolo; Kemper, Ann
2006-01-01
Theoretical calculations of neutralino cross sections with various nuclei are of great interest to direct dark matter searches such as CDMS, EDELWEISS, ZEPLIN, and other experiments. These cross sections and direct detection rates are generally computed with standard, one or two parameter model-dependent nuclear form factors, which may not exactly mirror the actual form factor for the particular nucleus in question. As is well known, elastic electron scattering can allow for very precise determinations of nuclear form factors and hence nuclear charge densities for spherical or near-spherical nuclei. We use charge densities derived from elastic electron scattering data to calculate model independent form factors for various target nuclei important in dark matter searches, such as Si, Ge, S, Ca and others. We have found that for nuclear recoils in the range of 1-100 keV significant differences in cross sections and rates exist when the model independent form factors are used. DarkSUSY, a publicly-available adva...
$D$ semileptonic form factors and $|V_{cs(d)}|$ from 2+1 flavor lattice QCD
Bailey, Jon A.; Bazavov, A.; El-Khadra, A.X.; Gottlieb, Steven; Jain, R.D.; Kronfeld, A.S.; Van de Water, R.S.; Zhou, R.
2011-11-01
The measured partial widths of the semileptonic decays D {yields} K{ell}{nu} and D {yields} {pi}{ell}{nu} can be combined with the form factors calculated on the lattice to extract the CKM matrix elements |V{sub cs}| and |V{sub cd}|. The lattice calculations can be checked by comparing the form factor shapes from the lattice and experiment. We have generated a sizable data set by using heavy clover quarks with the Fermilab interpretation for charm and asqtad staggered light quarks on 2+1 flavor MILC ensembles with lattice spacings of approximately 0.12, 0.09, 0.06, and 0.045 fm. Preliminary fits to staggered chiral perturbation theory suggest that we can reduce the uncertainties in the form factors at q{sup 2} = 0 to below 5%.
Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
Singh, B. [Aligarth Muslim Univ., Aligarth (India). Physics Dept.; Erni, W.; Krusche, B. [Basel Univ. (Switzerland); Collaboration: The PANDA Collaboration; and others
2016-10-15
Simulation results for future measurements of electromagnetic proton form factors at PANDA(FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel anti pp → e{sup +}e{sup -} is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e. anti pp → π{sup +}π{sup -}, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance. (orig.)
Excited state systematics in extracting nucleon electromagnetic form factors from the lattice
Rae, Thomas; Hippel, Georg von; Knippschild, Bastian [PRISMA Cluster of Excellence and Institut fuer Kernphysik, University of Mainz (Germany); Capitani, Stefano; Wittig, Hartmut; Jaeger, Benjamin; Meyer, Harvey; Della Morte, Michele [PRISMA Cluster of Excellence and Institut fuer Kernphysik, University of Mainz (Germany); Helmholtz Institute Mainz, University of Mainz (Germany)
2013-07-01
We present recent results for the nucleon electromagnetic form factors using lattice QCD. This includes the determination of the charge radii. The standard approach is to extract the form factors via a plateau fit to the lattice data using a 'large-enough' time separation between the operators at the source and sink. To check that this removes excited state contaminations to an acceptable level, we employ two further extraction methods: a fit that explicitly accounts for the contamination; and the use of a summed operator insertion, which suppresses the contamination. A comparison of the methods allows for the study of systematic effects related to excited state contributions entering in the q{sup 2} dependence of the form factors. We employ the CLS ensembles using non-perturbatively O(a) improved Wilson fermions in N{sub f}=2 QCD.
Effects of nuclear deformation on the form factor for direct dark matter detection
CHEN Ya-Zheng; CHEN Jun-Mou; LUO Yan-An; SHEN Hong; LI Xue-Qian
2012-01-01
For the detection of direct dark matter,in order to extract useful information about the fundamental interactions from the data,it is crucial to properly determine the nuclear form factor.The form factor for the spin-independent cross section of collisions between dark matter particles and the nucleus has been thoroughly studied by many authors.When the analysis was carried out,the nuclei were always supposed to be spherically symmetric.In this work,we investigate the effects of the deformation of nuclei from a spherical shape to an elliptical one on the form factor.Our results indicate that as long as the ellipticity is not too large,such deformation will not cause any substantial effects.In particular,when the nuclei are randomly orientated in room-temperature circumstances,one can completely neglect them.
Electromagnetic form factors of the Delta in a S-wave approach
Ramalho, G
2008-01-01
Without any further adjusting of parameters, a relativistic constituent quark model, successful in the description of the data for the nucleon elastic form factors and the dominant contribution to the nucleon to $\\Delta$ electromagnetic transition, is used here to predict the dominant electromagnetic form factors of the $\\Delta$ baryon. The model considered is based on a simple $\\Delta$ wave function corresponding to a quark-diquark system in an S-state. The results for E0 and M1 are consistent both with experimental results and lattice calculations. The remaining form factors M1 and E2 are negligible for small $Q^2$, as expected, given the symmetric structure considered for the $\\Delta$.
D semileptonic form factors and |V_cs(d)| from 2+1 flavor lattice QCD
Bailey, Jon A; El-Khadra, A X; Gottlieb, Steven; Jain, R D; Kronfeld, A S; Van de Water, R S; Zhou, R
2011-01-01
The measured partial widths of the semileptonic decays D to K l nu and D to pi l nu can be combined with the form factors calculated on the lattice to extract the CKM matrix elements |V_cs| and |V_cd|. The lattice calculations can be checked by comparing the form factor shapes from the lattice and experiment. We have generated a sizable data set by using heavy clover quarks with the Fermilab interpretation for charm and asqtad staggered light quarks on 2+1 flavor MILC ensembles with lattice spacings of approximately 0.12, 0.09, 0.06, and 0.045 fm. Preliminary fits to staggered chiral perturbation theory suggest that we can reduce the uncertainties in the form factors at zero invariant mass to below 5%.
B{yields}D{sup (*)} form factors from QCD light-cone sum rules
Faller, S. [Universitaet Siegen, Theoretische Physik 1, Fachbereich Physik, Siegen (Germany); CERN, Theory Division, Department of Physics, Geneva 23 (Switzerland); Khodjamirian, A.; Klein, C.; Mannel, T. [Universitaet Siegen, Theoretische Physik 1, Fachbereich Physik, Siegen (Germany)
2009-04-15
We derive new QCD sum rules for B{yields}D and B{yields}D{sup *} form factors. The underlying correlation functions are expanded near the light-cone in terms of B-meson distribution amplitudes defined in HQET, whereas the c-quark mass is kept finite. The leading-order contributions of two- and three-particle distribution amplitudes are taken into account. From the resulting light-cone sum rules we calculate all B{yields}D{sup (*)} form factors in the region of small momentum transfer (maximal recoil). In the infinite heavy-quark mass limit the sum rules reduce to a single expression for the Isgur-Wise function. We compare our predictions with the form factors extracted from experimental B{yields}D{sup (*)}l{nu} {sub l} decay rates fitted to dispersive parameterizations. (orig.)
B→ D (*) form factors from QCD light-cone sum rules
Faller, S.; Khodjamirian, A.; Klein, Ch.; Mannel, Th.
2009-04-01
We derive new QCD sum rules for B→ D and B→ D * form factors. The underlying correlation functions are expanded near the light-cone in terms of B-meson distribution amplitudes defined in HQET, whereas the c-quark mass is kept finite. The leading-order contributions of two- and three-particle distribution amplitudes are taken into account. From the resulting light-cone sum rules we calculate all B→ D (*) form factors in the region of small momentum transfer (maximal recoil). In the infinite heavy-quark mass limit the sum rules reduce to a single expression for the Isgur-Wise function. We compare our predictions with the form factors extracted from experimental B→(*) l ν l decay rates fitted to dispersive parameterizations.
$B \\to D^{(*)}$ Form Factors from QCD Light-Cone Sum Rules
Faller, S; Klein, Ch; Mannel, T
2009-01-01
We derive new QCD sum rules for $B\\to D$ and $B\\to D^*$ form factors. The underlying correlation functions are expanded near the light-cone in terms of $B$-meson distribution amplitudes defined in HQET, whereas the $c$-quark mass is kept finite. The leading-order contributions of two- and three-particle distribution amplitudes are taken into account. From the resulting light-cone sum rules we calculate all $B\\to \\Dst $ form factors in the region of small momentum transfer (maximal recoil). In the infinite heavy-quark mass limit the sum rules reduce to a single expression for the Isgur-Wise function. We compare our predictions with the form factors extracted from experimental $B\\to \\Dst l \
Feasibility studies of time-like proton electromagnetic form factors at overlinePANDA at FAIR
Singh, B.; Erni, W.; Krusche, B.; Steinacher, M.; Walford, N.; Liu, B.; Liu, H.; Liu, Z.; Shen, X.; Wang, C.; Zhao, J.; Albrecht, M.; Erlen, T.; Fink, M.; Heinsius, F.; Held, T.; Holtmann, T.; Jasper, S.; Keshk, I.; Koch, H.; Kopf, B.; Kuhlmann, M.; Kümmel, M.; Leiber, S.; Mikirtychyants, M.; Musiol, P.; Mustafa, A.; Pelizäus, M.; Pychy, J.; Richter, M.; Schnier, C.; Schröder, T.; Sowa, C.; Steinke, M.; Triffterer, T.; Wiedner, U.; Ball, M.; Beck, R.; Hammann, C.; Ketzer, B.; Kube, M.; Mahlberg, P.; Rossbach, M.; Schmidt, C.; Schmitz, R.; Thoma, U.; Urban, M.; Walther, D.; Wendel, C.; Wilson, A.; Bianconi, A.; Bragadireanu, M.; Caprini, M.; Pantea, D.; Patel, B.; Czyzycki, W.; Domagala, M.; Filo, G.; Jaworowski, J.; Krawczyk, M.; Lisowski, F.; Lisowski, E.; Michałek, M.; Poznański, P.; Płażek, J.; Korcyl, K.; Kozela, A.; Kulessa, P.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Szczurek, A.; Fiutowski, T.; Idzik, M.; Mindur, B.; Przyborowski, D.; Swientek, K.; Biernat, J.; Kamys, B.; Kistryn, S.; Korcyl, G.; Krzemien, W.; Magiera, A.; Moskal, P.; Pyszniak, A.; Rudy, Z.; Salabura, P.; Smyrski, J.; Strzempek, P.; Wronska, A.; Augustin, I.; Böhm, R.; Lehmann, I.; Nicmorus Marinescu, D.; Schmitt, L.; Varentsov, V.; Al-Turany, M.; Belias, A.; Deppe, H.; Dzhygadlo, R.; Ehret, A.; Flemming, H.; Gerhardt, A.; Götzen, K.; Gromliuk, A.; Gruber, L.; Karabowicz, R.; Kliemt, R.; Krebs, M.; Kurilla, U.; Lehmann, D.; Löchner, S.; Lühning, J.; Lynen, U.; Orth, H.; Patsyuk, M.; Peters, K.; Saito, T.; Schepers, G.; Schmidt, C. J.; Schwarz, C.; Schwiening, J.; Täschner, A.; Traxler, M.; Ugur, C.; Voss, B.; Wieczorek, P.; Wilms, A.; Zühlsdorf, M.; Abazov, V.; Alexeev, G.; Arefiev, V. A.; Astakhov, V.; Barabanov, M. Yu.; Batyunya, B. V.; Davydov, Y.; Dodokhov, V. Kh.; Efremov, A.; Fechtchenko, A.; Fedunov, A. G.; Galoyan, A.; Grigoryan, S.; Koshurnikov, E. K.; Lobanov, Y. Yu.; Lobanov, V. I.; Makarov, A. F.; Malinina, L. V.; Malyshev, V.; Olshevskiy, A. G.; Perevalova, E.; Piskun, A. A.; Pocheptsov, T.; Pontecorvo, G.; Rodionov, V.; Rogov, Y.; Salmin, R.; Samartsev, A.; Sapozhnikov, M. G.; Shabratova, G.; Skachkov, N. B.; Skachkova, A. N.; Strokovsky, E. A.; Suleimanov, M.; Teshev, R.; Tokmenin, V.; Uzhinsky, V.; Vodopianov, A.; Zaporozhets, S. A.; Zhuravlev, N. I.; Zorin, A. G.; Branford, D.; Glazier, D.; Watts, D.; Böhm, M.; Britting, A.; Eyrich, W.; Lehmann, A.; Pfaffinger, M.; Uhlig, F.; Dobbs, S.; Seth, K.; Tomaradze, A.; Xiao, T.; Bettoni, D.; Carassiti, V.; Cotta Ramusino, A.; Dalpiaz, P.; Drago, A.; Fioravanti, E.; Garzia, I.; Savrie, M.; Akishina, V.; Kisel, I.; Kozlov, G.; Pugach, M.; Zyzak, M.; Gianotti, P.; Guaraldo, C.; Lucherini, V.; Bersani, A.; Bracco, G.; Macri, M.; Parodi, R. F.; Biguenko, K.; Brinkmann, K.; Di Pietro, V.; Diehl, S.; Dormenev, V.; Drexler, P.; Düren, M.; Etzelmüller, E.; Galuska, M.; Gutz, E.; Hahn, C.; Hayrapetyan, A.; Kesselkaul, M.; Kühn, W.; Kuske, T.; Lange, J. S.; Liang, Y.; Metag, V.; Nanova, M.; Nazarenko, S.; Novotny, R.; Quagli, T.; Reiter, S.; Rieke, J.; Rosenbaum, C.; Schmidt, M.; Schnell, R.; Stenzel, H.; Thöring, U.; Ullrich, M.; Wagner, M. N.; Wasem, T.; Wohlfahrt, B.; Zaunick, H.; Ireland, D.; Rosner, G.; Seitz, B.; Deepak, P. N.; Kulkarni, A.; Apostolou, A.; Babai, M.; Kavatsyuk, M.; Lemmens, P. J.; Lindemulder, M.; Loehner, H.; Messchendorp, J.; Schakel, P.; Smit, H.; Tiemens, M.; van der Weele, J. C.; Veenstra, R.; Vejdani, S.; Dutta, K.; Kalita, K.; Kumar, A.; Roy, A.; Sohlbach, H.; Bai, M.; Bianchi, L.; Büscher, M.; Cao, L.; Cebulla, A.; Dosdall, R.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Herten, A.; Hu, Q.; Kemmerling, G.; Kleines, H.; Lehrach, A.; Nellen, R.; Ohm, H.; Orfanitski, S.; Prasuhn, D.; Prencipe, E.; Pütz, J.; Ritman, J.; Schadmand, S.; Sefzick, T.; Serdyuk, V.; Sterzenbach, G.; Stockmanns, T.; Wintz, P.; Wüstner, P.; Xu, H.; Zambanini, A.; Li, S.; Li, Z.; Sun, Z.; Xu, H.; Rigato, V.; Isaksson, L.; Achenbach, P.; Corell, O.; Denig, A.; Distler, M.; Hoek, M.; Karavdina, A.; Lauth, W.; Liu, Z.; Merkel, H.; Müller, U.; Pochodzalla, J.; Sanchez, S.; Schlimme, S.; Sfienti, C.; Thiel, M.; Ahmadi, H.; Ahmed, S.; Bleser, S.; Capozza, L.; Cardinali, M.; Dbeyssi, A.; Deiseroth, M.; Feldbauer, F.; Fritsch, M.; Fröhlich, B.; Jasinski, P.; Kang, D.; Khaneft, D.; Klasen, R.; Leithoff, H. H.; Lin, D.; Maas, F.; Maldaner, S.; Martínez, M.; Michel, M.; Mora Espí, M. C.; Morales Morales, C.; Motzko, C.; Nerling, F.; Noll, O.; Pflüger, S.; Pitka, A.; Rodríguez Piñeiro, D.; Sanchez-Lorente, A.; Steinen, M.; Valente, R.; Weber, T.; Zambrana, M.; Zimmermann, I.; Fedorov, A.; Korjik, M.; Missevitch, O.; Boukharov, A.; Malyshev, O.; Marishev, I.; Balanutsa, V.; Balanutsa, P.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Goryachev, V.; Chandratre, V.; Datar, V.; Dutta, D.; Jha, V.; Kumawat, H.; Mohanty, A. K.; Parmar, A.; Roy, B.; Sonika, G.; Fritzsch, C.; Grieser, S.; Hergemöller, A.; Hetz, B.; Hüsken, N.; Khoukaz, A.; Wessels, J. P.; Khosonthongkee, K.; Kobdaj, C.; Limphirat, A.; Srisawad, P.; Yan, Y.; Barnyakov, M.; Barnyakov, A. Yu.; Beloborodov, K.; Blinov, A. E.; Blinov, V. E.; Bobrovnikov, V. S.; Kononov, S.; Kravchenko, E. A.; Kuyanov, I. A.; Martin, K.; Onuchin, A. P.; Serednyakov, S.; Sokolov, A.; Tikhonov, Y.; Atomssa, E.; Kunne, R.; Marchand, D.; Ramstein, B.; van de Wiele, J.; Wang, Y.; Boca, G.; Costanza, S.; Genova, P.; Montagna, P.; Rotondi, A.; Abramov, V.; Belikov, N.; Bukreeva, S.; Davidenko, A.; Derevschikov, A.; Goncharenko, Y.; Grishin, V.; Kachanov, V.; Kormilitsin, V.; Levin, A.; Melnik, Y.; Minaev, N.; Mochalov, V.; Morozov, D.; Nogach, L.; Poslavskiy, S.; Ryazantsev, A.; Ryzhikov, S.; Semenov, P.; Shein, I.; Uzunian, A.; Vasiliev, A.; Yakutin, A.; Tomasi-Gustafsson, E.; Roy, U.; Yabsley, B.; Belostotski, S.; Gavrilov, G.; Izotov, A.; Manaenkov, S.; Miklukho, O.; Veretennikov, D.; Zhdanov, A.; Makonyi, K.; Preston, M.; Tegner, P.; Wölbing, D.; Bäck, T.; Cederwall, B.; Rai, A. K.; Godre, S.; Calvo, D.; Coli, S.; De Remigis, P.; Filippi, A.; Giraudo, G.; Lusso, S.; Mazza, G.; Mignone, M.; Rivetti, A.; Wheadon, R.; Balestra, F.; Iazzi, F.; Introzzi, R.; Lavagno, A.; Olave, J.; Amoroso, A.; Bussa, M. P.; Busso, L.; De Mori, F.; Destefanis, M.; Fava, L.; Ferrero, L.; Greco, M.; Hu, J.; Lavezzi, L.; Maggiora, M.; Maniscalco, G.; Marcello, S.; Sosio, S.; Spataro, S.; Birsa, R.; Bradamante, F.; Bressan, A.; Martin, A.; Calen, H.; Ikegami Andersson, W.; Johansson, T.; Kupsc, A.; Marciniewski, P.; Papenbrock, M.; Pettersson, J.; Schönning, K.; Wolke, M.; Galnander, B.; Diaz, J.; Pothodi Chackara, V.; Chlopik, A.; Kesik, G.; Melnychuk, D.; Slowinski, B.; Trzcinski, A.; Wojciechowski, M.; Wronka, S.; Zwieglinski, B.; Bühler, P.; Marton, J.; Steinschaden, D.; Suzuki, K.; Widmann, E.; Zmeskal, J.
2016-10-01
Simulation results for future measurements of electromagnetic proton form factors at overlinePANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel bar{p}p→ e+e- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e. bar{p}p→ π+π-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
New large-$N_c$ relations for the electromagnetic nucleon-to-$\\Delta$ form factors
Vladimir Pascalutsa; Marc Vanderhaeghen
2007-12-01
We establish relations which express the three $N\\to \\Delta$ transition form factors in terms of the nucleon form factors. These relations are based on the known large-$N_c$ relation between the $N\\to \\De$ electric quadrupole moment and the neutron charge radius, and a newly derived large-$N_c$ relation between the electric quadrupole ($E2$) and Coulomb quadrupole ($C2$) transitions. Namely, in the large-$N_c$ limit we find $C2=E2$. We show that these relations provide predictions for the $N\\to\\Delta$ electromagnetic form factors which are found to be in very good agreement with experiment for moderate momentum transfers. They also provide constraints for the $N \\to \\Delta$ GPDs.
Form Factors and Wave Functions of Vector Mesons in Holographic QCD
Hovhannes R. Grigoryan; Anatoly V. Radyushkin
2007-07-01
Within the framework of a holographic dual model of QCD, we develop a formalism for calculating form factors of vector mesons. We show that the holographic bound states can be described not only in terms of eigenfunctions of the equation of motion, but also in terms of conjugate wave functions that are close analogues of quantum-mechanical bound state wave functions. We derive a generalized VMD representation for form factors, and find a very specific VMD pattern, in which form factors are essentially given by contributions due to the first two bound states in the Q^2-channel. We calculate electric radius of the \\rho-meson, finding the value < r_\\rho^2>_C = 0.53 fm^2.
Lattice calculation of the pion transition form factor $\\pi^0 \\to \\gamma^* \\gamma^*$
Antoine, Gérardin; Nyffeler, Andreas
2016-01-01
We calculate the pion transition form factor ${\\cal F}_{\\pi^0\\gamma^*\\gamma^*}(q_1^2,q_2^2)$, which describe the interaction of an on-shell pion with two off-shell photons, using lattice QCD simulations with two degenerate flavors of dynamical quarks. This form factor is the main ingredient in the calculation of the pion-pole contribution to hadronic light-by-light scattering in the muon $g-2$, $a_\\mu^{\\mathrm{HLbL}; \\pi^0}$. We focus our study on the spacelike region with photon virtualities up to $1.5~\\mathrm{GeV}^2$, not yet measured experimentally. Several lattice spacings and pion masses are used to extrapolate the results to the physical point and a comparison with different phenomenological models is performed. Finally, we use our extrapolated form factor to provide a lattice determinaiton of $a_\\mu^{\\mathrm{HLbL}; \\pi^0}$.
Form factors of descendant operators: $A^{(1)}_{L-1}$ affine Toda theory
Alekseev, Oleg
2009-01-01
In the framework of the free field representation we obtain exact form factors of local operators in the two-dimensional affine Toda theories of the $A^{(1)}_{L-1}$ series. The construction generalizes Lukyanov's well-known construction to the case of descendant operators. Besides, we propose a free field representation with a countable number of generators for the `stripped' form factors, which generalizes the recent proposal for the sine/sinh-Gordon model. As a check of the construction we compare numbers of the operators defined by these form factors in level subspaces of the chiral sectors with the corresponding numbers in the Lagrangian formalism. We argue that the construction provides a correct counting for operators with both chiralities. At last we study the properties of the operators with respect to the Weyl group. We show that for generic values of parameters there exist Weyl invariant analytic families of the bases in the level subspaces.
JLab Measurements of the 3He Form Factors at Large Momentum Transfers
Camsonne, A; Olson, M; Acha, A; Allada, K; Anderson, B D; Arrington, J; Baldwin, A; Chen, J -P; Choi, S; Chudakov, E; Cisbani, E; Craver, B; Decowski, P; Dutta, C; Folts, E; Frullani, S; Garibaldi, F; Gilman, R; Gomez, J; Hahn, B; Hansen, J -O; Higinbotham, D W; Holmstrom, T; Huang, J; Iodice, M; Jiang, X; Kelleher, A; Khrosinkova, E; Kievsky, A; Kuchina, E; Kumbartzki, G; Lee, B; LeRose, J J; Lindgren, R A; Lott, G; Lu, H; Marcucci, L E; Margaziotis, D J; Markowitz, P; Marrone, S; Meekins, D; Meziani, Z -E; Michaels, R; Moffit, B; Norum, B; Petratos, G G; Puckett, A; Qian, X; Rondon, O; Saha, A; Sawatzky, B; Segal, J; Shabestari, M; Shahinyan, A; Solvignon, P; Sparveris, N; Subedi, R R; Suleiman, R; Sulkosky, V; Urciuoli, G M; Viviani, M; Wang, Y; Wojtsekhowski, B B; Yan, X; Yao, H; Zhang, W -M; Zheng, X; Zhu, L
2016-01-01
The charge and magnetic form factors, FC and FM, of 3He have been extracted in the kinematic range 25 fm-2 < Q2 < 61 fm-2 from elastic electron scattering by detecting 3He recoil nuclei and electrons in coincidence with the High Resolution Spectrometers of the Hall A Facility at Jefferson Lab. The measurements are indicative of a second diffraction minimum for the magnetic form factor, which was predicted in the Q2 range of this experiment, and of a continuing diffractive structure for the charge form factor. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the three-body nuclear problem.
Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
Singh, B.; Krusche, B.; Steinacher, M.; Walford, N.; Liu, B.; Liu, H.; Liu, Z.; Shen, X.; Wang, C.; Zhao, J.; Albrecht, M.; Erlen, T.; Fink, M.; Heinsius, F.; Held, T.; Holtmann, T.; Jasper, S.; Keshk, I.; Koch, H.; Kopf, B.; Kuhlmann, M.; Kümmel, M.; Leiber, S.; Mikirtychyants, M.; Musiol, P.; Mustafa, A.; Pelizäus, M.; Pychy, J.; Richter, M.; Schnier, C.; Schröder, T.; Sowa, C.; Steinke, M.; Triffterer, T.; Wiedner, U.; Ball, M.; Beck, R.; Hammann, C.; Ketzer, B.; Kube, M.; Mahlberg, P.; Rossbach, M.; Schmidt, C.; Schmitz, R.; Thoma, U.; Urban, M.; Walther, D.; Wendel, C.; Wilson, A.; Bianconi, A.; Bragadireanu, M.; Caprini, M.; Pantea, D.; Patel, B.; Czyzycki, W.; Domagala, M.; Filo, G.; Jaworowski, J.; Krawczyk, M.; Lisowski, F.; Lisowski, E.; Michałek, M.; Poznański, P.; Płażek, J.; Korcyl, K.; Kozela, A.; Kulessa, P.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Szczurek, A.; Fiutowski, T.; Idzik, M.; Mindur, B.; Przyborowski, D.; Swientek, K.; Biernat, J.; Kamys, B.; Kistryn, S.; Korcyl, G.; Krzemien, W.; Magiera, A.; Moskal, P.; Pyszniak, A.; Rudy, Z.; Salabura, P.; Smyrski, J.; Strzempek, P.; Wronska, A.; Augustin, I.; Böhm, R.; Lehmann, I.; Marinescu, D. Nicmorus; Schmitt, L.; Varentsov, V.; Al-Turany, M.; Belias, A.; Deppe, H.; Dzhygadlo, R.; Ehret, A.; Flemming, H.; Gerhardt, A.; Götzen, K.; Gromliuk, A.; Gruber, L.; Karabowicz, R.; Kliemt, R.; Krebs, M.; Kurilla, U.; Lehmann, D.; Löchner, S.; Lühning, J.; Lynen, U.; Orth, H.; Patsyuk, M.; Peters, K.; Saito, T.; Schepers, G.; Schmidt, C.J.; Schwarz, C.; Schwiening, J.; Täschner, A.; Traxler, M.; Ugur, C.; Voss, B.; Wieczorek, P.; Wilms, A.; Zühlsdorf, M.; Abazov, V.; Alexeev, G.; Arefiev, V.A.; Astakhov, V.; Barabanov, M. Yu.; Batyunya, B.V.; Davydov, Y.; Dodokhov, V. Kh.; Efremov, A.; Fechtchenko, A.; Fedunov, A.G.; Galoyan, A.; Grigoryan, S.; Koshurnikov, E.K.; Lobanov, Y. Yu.; Lobanov, V.I.; Makarov, A.F.; Malinina, L.V.; Malyshev, V.; Olshevskiy, A.G.; Perevalova, E.; Piskun, A.A.; Pocheptsov, T.; Pontecorvo, G.; Rodionov, V.; Rogov, Y.; Salmin, R.; Samartsev, A.; Sapozhnikov, M.G.; Shabratova, G.; Skachkov, N.B.; Skachkova, A.N.; Strokovsky, E.A.; Suleimanov, M.; Teshev, R.; Tokmenin, V.; Uzhinsky, V.; Vodopianov, A.; Zaporozhets, S.A.; Zhuravlev, N.I.; Zorin, A.G.; Branford, D.; Glazier, D.; Watts, D.; Böhm, M.; Britting, A.; Eyrich, W.; Lehmann, A.; Pfaffinger, M.; Uhlig, F.; Dobbs, S.; Seth, K.; Tomaradze, A.; Xiao, T.; Bettoni, D.; Carassiti, V.; Cotta Ramusino, A.; Dalpiaz, P.; Drago, A.; Fioravanti, E.; Garzia, I.; Savrie, M.; Akishina, V.; Kisel, I.; Kozlov, G.; Pugach, M.; Zyzak, M.; Gianotti, P.; Guaraldo, C.; Lucherini, V.; Bersani, A.; Bracco, G.; Macri, M.; Parodi, R.F.; Biguenko, K.; Brinkmann, K.; Di Pietro, V.; Diehl, S.; Dormenev, V.; Drexler, P.; Düren, M.; Etzelmüller, E.; Galuska, M.; Gutz, E.; Hahn, C.; Hayrapetyan, A.; Kesselkaul, M.; Kühn, W.; Kuske, T.; Lange, J.S.; Liang, Y.; Metag, V.; Nanova, M.; Nazarenko, S.; Novotny, R.; Quagli, T.; Reiter, S.; Rieke, J.; Rosenbaum, C.; Schmidt, M.; Schnell, R.; Stenzel, H.; Thöring, U.; Ullrich, M.; Wagner, M.N.; Wasem, T.; Wohlfahrt, B.; Zaunick, H.; Ireland, D.; Rosner, G.; Seitz, B.; Deepak, P.N.; Kulkarni, A.; Apostolou, A.; Babai, M.; Kavatsyuk, M.; Lemmens, P.J.; Lindemulder, M.; Loehner, H.; Messchendorp, J.; Schakel, P.; Smit, H.; Tiemens, M.; van der Weele, J.C.; Veenstra, R.; Vejdani, S.; Dutta, K.; Kalita, K.; Kumar, A.; Roy, A.; Sohlbach, H.; Bai, M.; Bianchi, L.; Büscher, M.; Cao, L.; Cebulla, A.; Dosdall, R.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Herten, A.; Hu, Q.; Kemmerling, G.; Kleines, H.; Lehrach, A.; Nellen, R.; Ohm, H.; Orfanitski, S.; Prasuhn, D.; Prencipe, E.; Pütz, J.; Ritman, J.; Schadmand, S.; Sefzick, T.; Serdyuk, V.; Sterzenbach, G.; Stockmanns, T.; Wintz, P.; Wüstner, P.; Xu, H.; Zambanini, A.; Li, S.; Li, Z.; Sun, Z.; Rigato, V.; Isaksson, L.; Achenbach, P.; Corell, O.; Denig, A.; Distler, M.; Hoek, M.; Karavdina, A.; Lauth, W.; Merkel, H.; Müller, U.; Pochodzalla, J.; Sanchez, S.; Schlimme, S.; Sfienti, C.; Thiel, M.; Ahmadi, H.; Ahmed, S.; Bleser, S.; Capozza, L.; Cardinali, M.; Dbeyssi, A.; Deiseroth, M.; Feldbauer, F.; Fritsch, M.; Fröhlich, B.; Jasinski, P.; Kang, D.; Khaneft, D.; Klasen, R.; Leithoff, H.H.; Lin, D.; Maas, F.; Maldaner, S.; Marta, M.; Michel, M.; Espí, M. C. Mora; Morales Morales, C.; Motzko, C.; Nerling, F.; Noll, O.; Pflüger, S.; Pitka, A.; Piñeiro, D. Rodríguez; Sanchez-Lorente, A.; Steinen, M.; Valente, R.; Weber, T.; Zambrana, M.; Zimmermann, I.; Fedorov, A.; Korjik, M.; Missevitch, O.; Boukharov, A.; Malyshev, O.; Marishev, I.; Balanutsa, V.; Balanutsa, P.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Goryachev, V.; Chandratre, V.; Datar, V.; Dutta, D.; Jha, V.; Kumawat, H.
2016-01-01
The results of simulations for future measurements of electromagnetic form factors at \\PANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision at which the proton form factors can be determined is estimated. The signal channel $\\bar p p \\to e^+ e^-$ is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e. the $\\bar p p \\to \\pi^+ \\pi^-$, is studied. Furthermore, the background versus signal efficiency, statistic and systematic uncertainties on the extracted proton form factors are evaluated using to the two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam condition and detector performances.
Research on Design Method of the Full Form Ship with Minimum Thrust Deduction Factor
张宝吉; 缪爱琴; 张竹心
2015-01-01
In the preliminary design stage of the full form ships, in order to obtain a hull form with low resistance and maximum propulsion efficiency, an optimization design program for a full form ship with the minimum thrust deduction factor has been developed, which combined the potential flow theory and boundary layer theory with the optimization technique. In the optimization process, the Sequential Unconstrained Minimization Technique (SUMT) interior point method of Nonlinear Programming (NLP) was proposed with the minimum thrust deduction factor as the objective function. An appropriate displacement is a basic constraint condition, and the boundary layer separation is an additional one. The parameters of the hull form modification function are used as design variables. At last, the numerical optimization example for lines of after-body of 50000 DWT product oil tanker was provided, which indicated that the propulsion efficiency was improved distinctly by this optimal design method.
Constraints on the ωπ form factor from analyticity and unitarity
Ananthanarayan, B.; Caprini, Irinel; Kubis, Bastian
2016-05-01
Form factors are important low-energy quantities and an accurate knowledge of these sheds light on the strong interactions. A variety of methods based on general principles have been developed to use information known in different energy regimes to constrain them in regions where experimental information needs to be tested precisely. Here we review our recent work on the electromagnetic ωπ form factor in a model-independent framework known as the method of unitarity bounds, partly motivated by the discrepancies noted recently between the theoretical calculations of the form factor based on dispersion relations and certain experimental data measured from the decay ω → π0γ∗. We have applied a modified dispersive formalism, which uses as input the discontinuity of the ωπ form factor calculated by unitarity below the ωπ threshold and an integral constraint on the square of its modulus above this threshold. The latter constraint was obtained by exploiting unitarity and the positivity of the spectral function of a QCD correlator, computed on the spacelike axis by operator product expansion and perturbative QCD. An alternative constraint is obtained by using data available at higher energies for evaluating an integral of the modulus squared with a suitable weight function. From these conditions we derived upper and lower bounds on the modulus of the ωπ form factor in the region below the ωπ threshold. The results confirm the existence of a disagreement between dispersion theory and experimental data on the ωπ form factor around 0.6 GeV, including those from NA60 published in 2016.
Kocken, Pl; van Dorst, Ag; Schaalma, H
2006-04-01
A study into the relevance of cultural factors in predicting condom-use intentions among Antillean migrants in the Netherlands is described in this article. The association between the intention to use condoms with a new sexual partner and a perceived taboo on discussing sex, beliefs about sex education and machismo beliefs on gender and power relationships is addressed. The study was conducted among 346 Dutch Antilleans from a random sample of an Antillean population aged 15-50 years. The response rate was 37.8%. The results showed that condom-use intentions were primarily determined by perceived subjective norms, the perceived taboo on discussing sex, machismo attitudes, gender, age and educational background. Moreover, the respondent's opinion regarding machismo was an effect modificator for the association between condom-use intentions and subjective social norm. It is concluded that, in predicting condom-use intentions, factors specific to the culture of a population contribute significantly to the determinants drawn from the general social-cognition models. It is recommended that future research should use measurement instruments that are adapted to culture-specific beliefs, and should explore the influence of cultural factors on actual condom use. Moreover, interventions promoting condom use among migrant populations should target the cultural correlates of condom use.
Kamphuisen, P.W.; Lee, A.Y.Y.; Meyer, Guy; Bauersachs, R.; Janas, M.S.; Jarner, M.F.; Khorana, A.A.
2015-01-01
Background: Cancer patients with acute venous thromboembolism (VTE) receiving anticoagulant treatment have a substantial risk of bleeding complications. Aims: To assess the rate, site and risk factors of clinically relevant bleeding (CRB; major or clinically relevant non-major bleeding) in cancer pa
De Sanctis, M; Santopinto, E; Vassallo, A
2015-01-01
We briefly describe our relativistic quark-diquark model, developed within the framework of point form dynamics, which is the relativistic extension of the interacting quark-diquark model. In order to do that we have to show the main properties and quantum numbers of the effective degree of freedom of constituent diquark. Our results for the nonstrange baryon spectrum and for the nucleon electromagnetic form factors are discussed.
Bianconi, Andrea; Tomasi-Gustafsson, Egle
2017-01-01
As is well known, spacelike proton form factors expressed in the Breit frame may be interpreted as the Fourier transform of static space distributions of electric charge and current. In particular, the electric form factor is simply the Fourier transform of the charge distribution F (q ) =∫ei q ⃗.r ⃗ρ (r ) d3r . We do not have an intuitive interpretation of the same level of simplicity for the proton timelike form factor appearing in the reactions e+e-↔p ¯p . However, one may suggest that, in the center-of-mass frame, where qμxμ=q t , a timelike electric form factor is the Fourier transform F (q ) =∫ei q tR (t ) d t of a function R (t ) expressing how the electric properties of the forming (or annihilating) proton-antiproton pair evolve in time. Here we analyze in depth this idea and show that the functions ρ (r ) and R (t ) can be formally written as the time and space integrals of a unique correlation function depending on both time and space coordinates.
Bianconi, Andrea
2016-01-01
As well known, spacelike proton form factors expressed in the Breit frame may be interpreted as the Fourier transform of static space distributions of electric charge and current. In particular, the electric form factor is simply the Fourier transform of the charge distribution $F(q)=\\int e^{i\\vec q \\cdot \\vec r} \\rho(r)d^3r$. We don't have an intuitive interpretation of the same level of simplicity for the proton timelike form factor appearing in the reactions $e^+e^-\\leftrightarrow \\bar{p}p$. However, one may suggest that in the center of mass (CM) frame, where $q_\\mu x^\\mu =qt$, a timelike electric form factor is the Fourier transform $F(q) =\\int e^{iqt} R(t)dt$ of a function $R(t)$ expressing how the electric properties of the forming (or annihilating) proton-antiproton pair evolve in time. Here we analyze in depth this idea, show that the functions $\\rho(r)$ and $R(t)$ can be formally written as the time and space integrals of a unique correlation function depending on both time and space coordinates.
Analysis of the J/psi --> pi^0 gamma^* transition form factor
Kubis, Bastian
2014-01-01
In view of the first measurement of the branching fraction for J/psi --> pi^0 e^+ e^- by the BESIII collaboration, we analyze what can be learnt on the corresponding transition form factor using dispersion theory. We show that light-quark degrees of freedom dominate the spectral function, in particular two-pion intermediate states. Estimating the effects of multi-pion states as well as charmonium, we arrive at a prediction for the complete form factor that should be scrutinized experimentally in the future.
On the pi pi continuum in the nucleon form factors and the proton radius puzzle
Hoferichter, M; de Elvira, J Ruiz; Hammer, H -W; Meißner, U -G
2016-01-01
We present an improved determination of the $\\pi\\pi$ continuum contribution to the isovector spectral functions of the nucleon electromagnetic form factors. Our analysis includes the most up-to-date results for the $\\pi\\pi\\to\\bar N N$ partial waves extracted from Roy-Steiner equations, consistent input for the pion vector form factor, and a thorough discussion of isospin-violating effects and uncertainty estimates. As an application, we consider the $\\pi\\pi$ contribution to the isovector electric and magnetic radii by means of sum rules, which, in combination with the accurately known neutron electric radius, are found to slightly prefer a small proton charge radius.
Light Cone Sum Rules for gamma*N ->Delta Transition Form Factors
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.
Measurement of the γγ*→π0 transition form factor
Aubert, B.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Osipenkov, I. L.; Tackmann, K.; Tanabe, T.; Hawkes, C. M.; Soni, N.; Watson, A. T.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Fulsom, B. G.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Barrett, M.; Khan, A.; Randle-Conde, A.; Blinov, V. E.; Bukin, A. D.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Bondioli, M.; Curry, S.; Eschrich, I.; Kirkby, D.; Lankford, A. J.; Lund, P.; Mandelkern, M.; Martin, E. C.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Yasin, Z.; Zhang, L.; Sharma, V.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Mazur, M. A.; Richman, J. D.; Beck, T. W.; Eisner, A. M.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Wang, L.; Winstrom, L. O.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Fang, F.; Hitlin, D. G.; Narsky, I.; Piatenko, T.; Porter, F. C.; Andreassen, R.; Mancinelli, G.; Meadows, B. T.; Mishra, K.; Sokoloff, M. D.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Hirschauer, J. F.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Wilson, R. J.; Feltresi, E.; Hauke, A.; Jasper, H.; Karbach, T. M.; Merkel, J.; Petzold, A.; Spaan, B.; Wacker, K.; Kobel, M. J.; Nogowski, R.; Schubert, K. R.; Schwierz, R.; Volk, A.; Bernard, D.; Latour, E.; Verderi, M.; Clark, P. J.; Playfer, S.; Watson, J. E.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cecchi, A.; Cibinetto, G.; Fioravanti, E.; Franchini, P.; Luppi, E.; Munerato, M.; Negrini, M.; Petrella, A.; Piemontese, L.; Santoro, V.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Tosi, S.; Chaisanguanthum, K. S.; Morii, M.; Adametz, A.; Marks, J.; Schenk, S.; Uwer, U.; Bernlochner, F. U.; Klose, V.; Lacker, H. M.; Bard, D. J.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Charles, M. J.; Mallik, U.; Cochran, J.; Crawley, H. B.; Dong, L.; Eyges, V.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gao, Y. Y.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Béquilleux, J.; D'Orazio, A.; Davier, M.; Derkach, D.; Firmino da Costa, J.; Grosdidier, G.; Le Diberder, F.; Lepeltier, V.; Lutz, A. M.; Malaescu, B.; Pruvot, S.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Burke, J. P.; Chavez, C. A.; Fry, J. R.; Gabathuler, E.; Gamet, R.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Clarke, C. K.; di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Paramesvaran, S.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; West, T. J.; Yi, J. I.; Anderson, J.; Chen, C.; Jawahery, A.; Roberts, D. A.; Simi, G.; Tuggle, J. M.; Dallapiccola, C.; Salvati, E.; Saremi, S.; Cowan, R.; Dujmic, D.; Fisher, P. H.; Henderson, S. W.; Sciolla, G.; Spitznagel, M.; Yamamoto, R. K.; Zhao, M.; Patel, P. M.; Robertson, S. H.; Schram, M.; Lazzaro, A.; Lombardo, V.; Palombo, F.; Stracka, S.; Bauer, J. M.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Zhao, H. W.; Simard, M.; Taras, P.; Nicholson, H.; de Nardo, G.; Lista, L.; Monorchio, D.; Onorato, G.; Sciacca, C.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; Losecco, J. M.; Wang, W. F.; Corwin, L. A.; Honscheid, K.; Kagan, H.; Kass, R.; Morris, J. P.; Rahimi, A. M.; Regensburger, J. J.; Sekula, S. J.; Wong, Q. K.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Kolb, J. A.; Lu, M.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Castelli, G.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Voci, C.; Del Amo Sanchez, P.; Ben-Haim, E.; Bonneaud, G. R.; Briand, H.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Perez, A.; Prendki, J.; Sitt, S.; Gladney, L.; Biasini, M.; Manoni, E.; Angelini, C.; Batignani, G.; Bettarini, S.; Calderini, G.; Carpinelli, M.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Morganti, M.; Neri, N.; Paoloni, E.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Baracchini, E.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Jackson, P. D.; Li Gioi, L.
2009-09-01
We study the reaction e+e-→e+e-π0 in the single tag mode and measure the differential cross section dσ/dQ2 and the γγ*→π0 transition form factor in the momentum transfer range from 4 to 40GeV2. At Q2>10GeV2 the measured form factor exceeds the asymptotic limit predicted by perturbative QCD. The analysis is based on 442fb-1 of integrated luminosity collected at PEP-II with the BABAR detector at e+e- center-of-mass energies near 10.6 GeV.
Lattice study of D and D{sub s} meson form factors with twisted boundary conditions
Li, Ning; Wu, Ya-Jie [Xi' an Technological University, School of Science, Xi' an (China)
2017-03-15
We present results on the D and D{sub s} meson electromagnetic form factors using N{sub f} = 2 twisted mass Lattice Quantum Chromodynamics (LQCD) gauge configurations. In this simulation, to access spatial components of momenta that are different from the integer multiples of 2π/L, we apply twisted boundary conditions to compute corresponding correlation functions. Electromagnetic form factors with more small four-momentum transfer are determined, and further we fit the electromagnetic charge radius for D and D{sub s} mesons, respectively. (orig.)
Analysis of the J /ψ →π0γ* transition form factor
Kubis, Bastian; Niecknig, Franz
2015-02-01
In view of the first measurement of the branching fraction for J /ψ →π0e+e- by the BESIII collaboration, we analyze what can be learned on the corresponding transition form factor using dispersion theory. We show that light-quark degrees of freedom dominate the spectral function, in particular two-pion intermediate states. Estimating the effects of multipion states as well as charmonium, we arrive at a prediction for the complete form factor that should be scrutinized experimentally in the future.
Electromagnetic form factors for spin-1 particles with the light-front
Mello, Clayton S. [Laboratório de Física Teórica e Computacional (LFTC), Universidade Cruzeiro do Sul, 01506-000, São Paulo (Brazil); Departamento de Física, Instituto Tecnológico de Aeronáutica, 12.228-900 São José dos Campos, São Paulo (Brazil); Nunes da Silva, Anacé; Melo, J.P.B.C. de [Laboratório de Física Teórica e Computacional (LFTC), Universidade Cruzeiro do Sul, 01506-000, São Paulo (Brazil); Frederico, T. [Departamento de Física, Instituto Tecnológico de Aeronáutica, 12.228-900 São José dos Campos, São Paulo (Brazil)
2014-06-15
This work is dedicate to investigate the spin-1 electromagnetic form factors with the light-front quantum field theory approach. All prescriptions with the light-front approach are contamined by the zero-modes contribuitions to the electromagnetic matrix elements of the electromagnetic current with the plus component of the current; however, the Inna Grach prescriptions it is immune for the zero modes contribuitions. We show numerically the contribution of zero-modes for the electromagnetic current in the case of the vector particles in the light-front quantum field theory. Also the electromagnetic observables, like electromagnetic form factors, radius and the decay constant are presented.
Nucleon shape and electromagnetic form factors in the chiral constituent quark model
Dahiya, Harleen
2010-01-01
The electromagnetic form factors are the most fundamental quantities to describe the internal structure of the nucleon and the shape of a spatially extended particle is determined by its intrinsic quadrupole moment which can be related to the charge radii. We have calculated the electromagnetic form factors, nucleon charge radii and the intrinsic quadrupole moment of the nucleon in the framework of chiral constituent quark model. The results obtained are comparable to the latest experimental studies and also show improvement over some theoretical interpretations.
Hyperon elastic electromagnetic form factors in the space-like momentum region
Sanchis-Alepuz, Helios [Justus-Liebig-Universitaet Giessen, Institut fuer Theoretische Physik, Giessen (Germany); Karl-Franzens-Universitaet Graz, Institut fuer Physik, Graz (Austria); Fischer, Christian S. [Justus-Liebig-Universitaet Giessen, Institut fuer Theoretische Physik, Giessen (Germany)
2016-02-15
We present a calculation of the electric and magnetic form factors of ground-state octet and decuplet baryons including strange quarks. We work with a combination of Dyson-Schwinger equations for the quark propagator and covariant Bethe-Salpeter equations describing baryons as bound states of three (non-perturbative) quarks. Our form factors for the octet baryons are in good agreement with corresponding lattice data at finite Q{sup 2}; deviations in some isospin channels for the magnetic moments can be explained by missing meson cloud effects. At larger Q{sup 2} our quark core calculation has predictive power for both, the octet and decuplet baryons. (orig.)
Form Factors and Generalized Parton Distributions in Basis Light-Front Quantization
Adhikari, Lekha; Zhao, Xingbo; Maris, Pieter; Vary, James P; El-Hady, Alaa Abd
2016-01-01
We calculate the elastic form factors and the Generalized Parton Distributions (GPDs) for four low-lying bound states of a demonstration fermion-antifermion system, strong coupling positronium ($e \\bar{e}$), using Basis Light-Front Quantization (BLFQ). Using this approach, we also calculate the impact-parameter dependent GPDs $q(x, {\\vec b_\\perp})$ to visualize the fermion density in the transverse plane (${\\vec b_\\perp}$). We compare selected results with corresponding quantities in the non-relativistic limit to reveal relativistic effects. Our results establish the foundation within BLFQ for investigating the form factors and the GPDs for hadronic systems.
Computation of form factors in massless QCD with finite master integrals
von Manteuffel, Andreas; Panzer, Erik; Schabinger, Robert M.
2016-06-01
We present the bare one-, two-, and three-loop form factors in massless quantum chromodynamics as linear combinations of finite master integrals. Using symbolic integration, we compute their ɛ expansions and thereby reproduce all known results with an independent method. Remarkably, in our finite basis, only integrals with a less-than-maximal number of propagators contribute to the cusp anomalous dimensions. We report on indications of this phenomenon at four loops, including the result for a finite, irreducible, twelve-propagator form factor integral. Together with this article, we provide our automated software setup for the computation of finite master integrals.
On the Computation of Form Factors in Massless QCD with Finite Master Integrals
von Manteuffel, Andreas; Schabinger, Robert M
2015-01-01
We present the bare one-, two-, and three-loop form factors in massless Quantum Chromodynamics as linear combinations of finite master integrals. Using symbolic integration, we compute their $\\epsilon$ expansions and thereby reproduce all known results with an independent method. Remarkably, in our finite basis, only integrals with a less-than-maximal number of propagators contribute to the cusp anomalous dimensions. We report on indications of this phenomenon at four loops, including the result for a finite, irreducible, twelve-propagator form factor integral. Together with this article, we provide our automated software setup for the computation of finite master integrals.
Constructing Nucleon Operators on a Lattice for Form Factors with High Momentum Transfer
Syritsyn, Sergey [Stony Brook Univ., NY (United States); Gambhir, Arjun S. [College of William and Mary, Williamsburg, VA (United States); Musch, Bernhard U. [Univ. of Regensburg (Germany); Orginos, Konstantinos [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2017-05-01
We present preliminary results of computing nucleon form factor at high momentum transfer using the 'boosted' or 'momentum' smearing. We use gauge configurations generated with N f = 2 + 1dynamical Wilson-clover fermions and study the connected as well as disconnected contributions to the nucleon form factors. Our initial results indicate that boosted smearing helps to improve the signal for nucleon correlators at high momentum. However, we also find evidence for large excited state contributions, which will likely require variational analysis to isolate the boosted nucleon ground state.
Nucleon and gamma N -> Delta lattice form factors in a constituent quark model
Ramalho, G
2008-01-01
A covariant quark model, based both on the spectator formalism and on Vector Meson Dominance, and previously calibrated by the physical data, is here extended to the unphysical region of the lattice data by means of one single extra adjustable parameter - the constituent quark mass in the chiral limit. We calculated the Nucleon (N) and the Gamma N -> Delta form factors in the universe of values for that parameter described by quenched lattice QCD. A qualitative description of the Nucleon and Gamma N -> Delta form factors lattice data is achieved for light pion masses.
Axial vector form factors in Ds to phi semileptonic decays from lattice QCD
Donald, Gordon; Koponen, Jonna
2011-01-01
We calculate axial vector and vector form factors for the semileptonic decay Ds to phi using HISQ valence quarks on MILC ensembles with 2+1 flavours of asqtad sea quarks. Using twisted boundary conditions to tune the quarks' momenta, we compute form factors at q^2 = 0 on coarse lattices. We find V(0)=0.903(67), A_1(0)= 0.603(20), A_2(0)=0.401(80) and A_0(0)=0.686(17), which we compare to experimental data and previous quenched lattice QCD calculations.
Light-Front Model of Transition Form-Factors in Heavy Meson Decay
de Melo, J P B C
2010-01-01
Electroweak transition form factors of heavy meson decays are important ingredients in the extraction of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements from experimental data. In this work, within a light-front framework, we calculate electroweak transition form factor for the semileptonic decay of $D$ mesons into a pion or a kaon. The model results underestimate in both cases the new data of CLEO for the larger momentum transfers accessible in the experiment. We discuss possible reasons for that in order to improve the model.
On the ππ continuum in the nucleon form factors and the proton radius puzzle
Hoferichter, M.; Kubis, B.; Ruiz de Elvira, J.; Hammer, H.-W.; Meißner, U.-G.
2016-11-01
We present an improved determination of the ππ continuum contribution to the isovector spectral functions of the nucleon electromagnetic form factors. Our analysis includes the most up-to-date results for the ππ→bar{N} N partial waves extracted from Roy-Steiner equations, consistent input for the pion vector form factor, and a thorough discussion of isospin-violating effects and uncertainty estimates. As an application, we consider the ππ contribution to the isovector electric and magnetic radii by means of sum rules, which, in combination with the accurately known neutron electric radius, are found to slightly prefer a small proton charge radius.
Test of the triple Higgs boson form factor in $\\mu^-\\mu^+\\to HH$
Gounaris, G J
2016-01-01
We study the sensitivity of the process $\\mu^-\\mu^+\\to HH$ to the $q^2$-dependence of the $HHH$ form factor, which can reflect the Higgs boson structure, especially in the case of compositeness. We compute the Born and 1 loop SM contribution to this process. We then show how the $\\mu^-\\mu^+\\to HH$ polarized and unpolarized cross sections are modified by the presence of various types of anomalous contributions to the $HHH$ form factor, in particular Higgs constituents in the case of compositeness.
Kaon photoproduction with form factors in a gauge-invariant approach
Haberzettl, H; Mart, T; Feuster, T
1998-01-01
The general gauge-invariant photoproduction formalism given by Haberzettl is applied to kaon photoproduction off the nucleon at the tree level, with form factors describing composite nucleons. We demonstrate that, in contrast to Ohta's gauge-invariance prescription, this formalism allows electric current contributions to be multiplied by a form factor, i.e., they do not need to be treated like bare currents. Numerical results show that Haberzettl's gauge procedure, when compared to Ohta's, leads to much improved $\\chi^2$ values. Moreover, predictions for the new Bonn SAPHIR data for $p(\\gamma,K^+)\\Lambda$ are given.
Phenomenological analysis of near threshold periodic modulations of the proton timelike form factor
Bianconi, A
2015-01-01
We have recently highlighted the presence of a periodically oscillating 10 \\% modulation in the BABAR data on the proton timelike form factors, in the reaction $e^++e^-$ $\\rightarrow$ $\\bar{p}+p$. Here we deepen our previous data analysis, and confirm that in the case of several standard parametrizations it is possible to write the form factor in the form $F_0$ $+$ $F_{osc}$, where $F_0$ is a parametrization expressing the long-range trend of the form factor (for $q^2$ ranging from the $\\bar{p}p$ threshold to 36 GeV$^2$), and $F_{osc}$ is a function of the form $\\exp(-Bp)\\cos(Cp)$, where $p$ is the relative momentum of the final $\\bar{p}p$ pair. Error bars allow for a clean identification of the main features of this modulation for $q^2$ $<$ 10 GeV$^2$. Assuming this oscillatory modulation to be an effect of final state interactions between the forming proton and the antiproton, we propose a phenomenological model based on a double-layer imaginary optical potential. This potential is flux-absorbing when th...
Model-independent constraints on hadronic form factors with above-threshold poles
Caprini, Irinel; Grinstein, Benjamín; Lebed, Richard F.
2017-08-01
Model-independent constraints on hadronic form factors, in particular those describing exclusive semileptonic decays, can be derived from the knowledge of field correlators calculated in perturbative QCD, using analyticity and unitarity. The location of poles corresponding to below-threshold resonances, i.e., stable states that cannot decay into a pair of hadrons from the crossed channel of the form factor, must be known a priori, and their effect, accounted for through the use of Blaschke factors, is to reduce the strength of the constraints in the semileptonic region. By contrast, above-threshold resonances appear as poles on unphysical Riemann sheets, and their presence does not affect the original model-independent constraints. We discuss the possibility that the above-threshold poles can provide indirect information on the form factors on the first Riemann sheet, either through information from their residues or by constraining the discontinuity function. The bounds on form factors can be improved by imposing, in an exact way, the additional information in the extremal problem. The semileptonic K →π ℓν and D →π ℓν decays are considered as illustrations.
Eletroweak Form Factors in the Light-Front for Spin-1 Particles
de Melo, J P B C; 10.1007/s00601-011-0295-9
2012-01-01
The contribution of the light-front valence wave function to the electromagnetic current of spin-1 composite particles is not enough to warranty the proper transformation of the current under rotations. The naive derivation of the plus component of the current in the Drell-Yan-West frame within an analytical and covariant model of the vertex leads to the violation of the rotational symmetry. Computing the form-factors in a quasi Drell-Yan-West frame $q^+\\rightarrow 0$, we were able to separate out in an analytical form the contributions from Z-diagrams or zero modes using the instant-form cartesian polarization basis.
Kegel, Karen; DeBlaere, Cirleen
2014-07-01
Despite apparent relevance to Asian international students, universal-diverse orientation (UDO) has not been psychometrically validated with this population. The current study investigated the most researched UDO measure, the Miville-Guzman Universality-Diversity Scale, Short Form (M-GUDS-S; Fuertes, Miville, Mohr, Sedlacek, & Gretchen, 2000), with 333 Asian international college students. The M-GUDS-S evidenced good reliability and convergent validity, and analyses confirmed a three-factor structure, supporting expanded use of the scale.
Measurement of the proton form factor by studying e(+)e(-) -> p(p)over-tilde
Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Ferroli, R. Baldini; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Cibinetto, G.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; De Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Fava, L.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, X. Y.; Gao, Y.; Gao, Z.; Garzia, I.; Geng, C.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y.; Guo, Y. P.; Haddadi, Z.; Hafner, A.; Han, S.; Han, Y. L.; Hao, X. Q.; Harris, F. A.; He, K. L.; He, Z. Y.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. M.; Huang, G. S.; Huang, H. P.; Huang, J. S.; Huang, X. T.; Huang, Y.; Hussain, T.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. L.; Jiang, L. W.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Kliemt, R.; Kloss, B.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kuehn, W.; Kupsc, A.; Lai, W.; Lange, J. S.; Lara, M.; Larin, P.; Leng, C.; Li, C. H.; Li, Cheng; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, Lei; Li, P. R.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. M.; Li, X. N.; Li, X. Q.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B. J.; Liu, C. X.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, R. Q.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lv, M.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X. N.; Ma, X. Y.; Maas, F. E.; Maggiora, M.; Malik, Q. A.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Morales, C. Morales; Moriya, K.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Pettersson, J.; Ping, J. L.; Ping, R. G.; Poling, R.; Pu, Y. N.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Y.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ren, H. L.; Ripka, M.; Rong, G.; Ruan, X. D.; Santoro, V.; Sarantsev, A.; Savrie, M.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Tiemens, M.; Toth, D.; Ullrich, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q. J.; Wang, S. G.; Wang, W.; Wang, X. F.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Wei, J. B.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, Z.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. X.; Yang, L.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, H. W.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, S. H.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. T.; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, Li; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zotti, L.; Zou, B. S.; Zou, J. H.
2015-01-01
Using data samples collected with the BESIII detector at the BEPCII collider, we measure the Born cross section of e(+)e(-) -> p (p) over tilde at 12 center-of-mass energies from 2232.4 to 3671.0 MeV. The corresponding effective electromagnetic form factor of the proton is deduced under the assumpti
On the slope of the scalar K$_{l3}$ decay form factor
Renner, B
1973-01-01
Discusses a mechanism, based on exact threshold theorems in the limit of SU(2)*SU(2) symmetry, which can be used to estimate a certain suppression of the scalar K/sub l3/ decay form factor at low momentum transfers, while maintaining the validity of the Callan-Treiman relation. (6 refs).
Nucleon momentum distributions and elastic electron scattering form factors for some 1p-shell nuclei
A K Hamoudi; M A Hasan; A R Ridha
2012-05-01
The nucleon momentum distributions (NMD) and elastic electron scattering form factors of the ground state for 1p-shell nuclei with = (such as 6Li, 10B, 12C and 14N nuclei) have been calculated in the framework of the coherent density ﬂuctuation model (CDFM) and expressed in terms of the weight function $|f(x)|^2$. The weight function has been expressed in terms of nucleon density distribution (NDD) of the nuclei and determined from the theory and the experiment. The feature of the long-tail behaviour at high-momentum region of the NMDs has been obtained by both the theoretical and experimental weight functions. The experimental form factors $F(q)$ of all the considered nuclei are very well reproduced by the present calculations for all values of momentum transfer . It is found that the contributions of the quadrupole form factors $F_{C2}(q)$ in 10B and 14N nuclei, which are described by the undeformed p-shell model, are essential for obtaining a remarkable agreement between the theoretical and experimental form factors.
A Diquark-Quark Model with Its Use in Nucleon Form Factors
WANG Hong-Min; ZHANG Ben-Ai
2005-01-01
The nucleon electromagnetic form factors are investigated within a simple diquark-quark model using the light-front formalism. In this model, baryon is described as a bound state of one quark and one clustering diquark.The calculational results are compared with the experimental ones. We also regard the quarks in a baryon as pointlike constituent quarks.
Urban form and psychosocial factors : Do they interact for leisure-time walking?
Beenackers, Mariëlle A.; Kamphuis, Carlijn B M; Prins, Richard G.; Mackenbach, Johan P.; Burdorf, Alex; Van Lenthe, Frank J.
2014-01-01
INTRODUCTION: This cross-sectional study uses an adaptation of a social-ecological model on the hierarchy of walking needs to explore direct associations and interactions of urban-form characteristics and individual psychosocial factors for leisure-time walking. METHODS: Questionnaire data (n = 736)
Factor Structure and Short Form of the Miville-Guzman Universality-Diversity Scale.
Fuertes, Jairo N.; Miville, Marie L.; Mohr, Jonathan J.; Sedlacek, William E.; Gretchen, Denise
2000-01-01
Examines the factor structure of the Miville-Guzman Universality-Diversity Scale (M-GUDS) and presents a short form of the scale (M-GUDS-S). Findings suggest that the M-GUDS-S measures Universal-Diverse Orientation as a multidimensional construct with three distinct domains: behavioral, emotional, and cognitive. (Contains 21 references and 3…
Ma, K.; Yang, F.; Both, Sanne Karijn; Prins, H.J.; Helder, M.N.; Pan, J.; Cui, F.Z.; Jansen, J.A.; van den Beucken, J.J.
2015-01-01
The aim of this study was to compare the effect of implantation site (i.e., subcutaneous, SQ vs. intramuscular, IM) on bone forming capacity of cell-based and growth factor-based scaffolds in athymic nude rats after an implantation period of 8 weeks. Cell-based scaffolds consisted of porous
Nucleon electromagnetic form factors in a relativistic quark model with chiral symmetry
Barik, N.; Das, M.
1987-05-01
The nucleon electromagnetic form factors are computed in an independent quark model based on the Dirac equation. Corrections for centre-of-mass motion and pion-cloud effects are incorporated. Results for static quantities are in reasonable agreement with the experimental data.
Axial Nucleon to Delta transition form factors on 2+1 flavor hybrid lattices
Alexandrou, C; Leontiou, Th; Negele, J W; Tsapalis, A; 10.1103/PhysRevD.80.099901
2009-01-01
We correct the values of the dominant nucleon to Delta axial transition form factors CA_5 and CA_6 published in C. Alexandrou et.al., Phys. Rev. D 76,094511 (2007). The analysis error affects only the values obtained when using the hybrid action in the low Q^2 regime bringing them into agreement with those obtained with Wilson fermions.