anomalous magnetic dipole moment

The authors study several distinguished geometrical properties of the time-dependent Lagrangians governing the 2D-motions of a particle of a monolayer. They apply several ideas of R. Miron and M. Anastasiei concerning Lagrangian geometry on the tangent bundle [The geometry of Lagrange spaces: theory and applications. Fundamental Theories of Physics. 59. Dordrecht: Kluwer Academic Publishers. (1994; Zbl 0831.53001)]. The considered curvature of the investigated slices is a Finsler flag curvature. The metric induced by a 2D monolayer Lagrangian is of Berwald-Lagrange curvature. It is proved that this is a scalar curvature, and its sign governs the geodesic deviation in the monolayer. They determine the components of the canonical semispray of the energy functional associated to the 2D monolayer Lagrangian, and the components of the Berwald N-linear connection. Also the physical meaning is explained.Reviewer: Lajos Tamássy (Debrecen)

We compute the one loop, O(θ) correction to the vertex in the noncommutative Chern-Simons theory with scalar fields in the fundamental representation. Emphasis is placed on the parity odd part of the vertex, since the same leads to the magnetic moment structure. We find that, apart from the commutative term, a θ-dependent magnetic moment type structure is induced. In addition to the usual commutative graph, cubic photon vertices also give a finite θ dependent contribution. Furthermore, the two two-photon vertex diagrams, that give zero in the commutative case yield finite θ dependent terms to the vertex function.

We compute the one loop, O(θ) correction to the vertex in the noncommutative Chern-Simons theory with scalar fields in the fundamental representation. Emphasis is placed on the parity odd part of the vertex, since the same leads to the magnetic moment structure. We find that, apart from the commutative term, a θ-dependent magnetic moment type structure is induced. In addition to the usual commutative graph, cubic photon vertices also give a finite θ dependent contribution. Furthermore, the two two-photon vertex diagrams, that give zero in the commutative case yield finite θ dependent terms to the vertex function.

A compact relation between the fine-structure constant, the Bohr magneton, and the electron magnetic moment is reformulated within the Mo framework as α/(1-µ B /µ e) = 2π(g e-1). From this, a quadratic expression for the electron g-factor arises, whose solution is shown to agree with the latest CODATA value. The presence of 2π highlights a potential geometric underpinning of the electron magnetic moment.

The behavior of finite temperature planar electrodynamics is investigated. We calculate the static as well as dynamic characteristic functions using real time formalism. The temperature and density dependence of dielectric and permeability functions, plasmon frequencies and their relation to the screening length is determined. The radiative correction to the fermion mass is also calculated. We also calculate the temperature dependence of the electron (anyon) magnetic moment. Our results for the gyromagnetic ratio go smoothly to the known result at zero temperature, g = 2, in accordance with the general expectation.

We analyze, in a rather general model where anomalous triple gauge couplings are present, the visible effects in R b (measured at LEP1), in W pair production (to be measured at LEP2) and in the muon anomalous magnetic moment (to be measured at BNL). From the combination of the three experiments a remarkable improvement on the pure LEP2 constraints is obtained.

In a Dark left-right gauge model, the neutral component of right-handed lepton doublet is odd under generalized R-parity and thus the lightest one serves as the dark matter (DM) candidate. The coannihilation of the dark matter with the singly charged Higgs triplet produces the correct relic abundance. We explain AMS-02 positron excess by the annihilation of 800 GeV dark matter into µ + µ -γ, through a t-channel exchange of the additional charged triplet Higgs boson. The DM is leptophilic which is useful for explaining the non-observation of any antiproton excess which would generically be expected from DM annihilation. The large cross-section needed to explain AMS-02 also requires an astrophysical boost. In addition, we show that the muon (g -2) receives required contribution from singly and doubly charged triplet Higgs in the loops.

Neutrino non-standard interactions (NSI) with the first generation of standard model fermions can span a parameter space of large dimension and exhibit degeneracies that cannot be broken by a single class of experiment. Oscillation experiments, together with neutrino scattering experiments, can merge their observations into a highly informational dataset to combat this problem. We consider combining neutrino-electron and neutrino-nucleus scattering data from the Borexino and COHERENT experiments, including a projection for the upcoming coherent neutrino scattering measurement at the CENNS-10 liquid argon detector. We extend the reach of these data sets over the NSI parameter space with projections for neutrino scattering at a future multi-ton scale dark matter detector and future oscillation measurements from atmospheric neutrinos at the Deep Underground Neutrino Experiment (DUNE). In order to perform this global analysis, we adopt a novel approach using the copula method, utilized to combine posterior information from different experiments with a large, generalized set of NSI parameters. We find that the contributions from DUNE and a dark matter detector to the Borexino and COHERENT fits can improve constraints on the electron and quark NSI parameters by up to a factor of 2 to 3, even when relatively many NSI parameters are left free to vary in the analysis.

Compared to other neutrino sources, the huge anti-neutrino fluxes at nuclear reactor based experiments empower us to derive stronger bounds on non-standard interactions of neutrinos with electrons mediated by light scalar/vector mediators. At neutrino energy around 200 keV reactor anti-neutrino flux is at least an order of magnitude larger compared to the solar flux. The atomic and crystal form factors of the detector materials related to the details of the atomic structure becomes relevant at this energy scale as the momentum transfers would be small. Nonstandard neutrino-electron interaction mediated by light scalar/vector mediator arises naturally in many low-scale models. We also propose one such new model with a light scalar mediator. Here, we investigate the parameter space of such low-scale models in reactor based neutrino experiments with low threshold Ge and Si detectors, and find the prospect of probing/ruling out the relevant parameter space by finding the projected sensitivity at 90% confidence level by performing a χ 2analysis. We find that a detector capable of discriminating between electron recoil and nuclear recoil signal down to a very low threshold such as 5 eV placed in reactor based experiment would be able to probe a larger region in parameter space compared to the previously explored region. A Ge (Si) detector with 10 kg-yr exposure and 1 MW reactor anti-neutrino flux would be able to probe the scalar and vector mediators with masses below 1 keV for coupling products √ g ν g e ∼ 1 × 10 -6 (9.5 × 10 -7 ) and 1 × 10 -7 (8 × 10 -8 ), respectively.

We present benchmarks for the Inert Doublet Model, a Two Higgs Doublet Model with a dark matter candidate. They are consistent with current constraints on direct detection, including the most recent bounds from the XENON1T experiment and relic density of dark matter, as well as with known collider and low-energy limits. We focus on parameter choices that promise detectable signals at lepton colliders via pair-production of H + H -and HA. For these we choose a large variety of benchmark points with different kinematic features, leading to distinctly different final states in order to cover the large variety of collider signatures that can result from the model.

We present a derivation from first principles of two fundamental physical constants: the anomalous magnetic moment of the muon (a µ ≈ 2.5089 × 10-9) and the fine-structure constant (α-1 ≈ 137.035999), within the Unified Theory of Neutral Granular Wave Medium (TUOMGN). This theory postulates a preexistent, isotropic medium composed of massless neutral granular units through which guide waves propagate, coupling with massive particles. Both a µ and α emerge from helicoidal resonances in a toroidal geometry, without empirical adjustments. Our predictions match experimental values within 0.0027σ (muon) and 0.146σ (alpha), resolving the 4.2σ discrepancy in a µ of the Standard Model (1), and establishing TUOMGN as a promising framework for unifying fundamental interactions.

The explicit form of operators of kinetic momenta and spin projection for a neutral particle with an anomalous magnetic moment in constant homogeneous electromagnetic field is found. The possible applications of the obtained results in neutrino physics are considered.

Recognizing the potential of effective field theories to posit multiple BSM scenarios in similar footing, with a possibility to compare them, we inspect the effects of 11 single scalar-multiplet extensions of the SM on the combined set of electroweak precision observables and Higgs signal strength data, by systematically integrating out the heavy multiplets and computing the resulting SMEFT operators and Wilson coefficients (WCs) up to one-loop level. Noting that multiple BSM models give rise to a degenerate set of WCs, we then perform Bayesian statistical inference both directly on the BSM parameters and on the associated set of independent WCs. Using the posteriors of the BSM parameters, we infer the respective (correlated) WC-distributions and compare both the model independent and dependent analyses by overlaying the 2-D marginal WC-posteriors from both processes, thus laying the ground for a data-driven attempt to compare diverse BSM theories of different origins, and hopefully...

Following a new measurement of the anomalous magnetic moment (AMM) a_μ of the positive muon at Fermi National Accelerator Laboratory and a revised prediction of the standard model (SM) value of a_μ by the Muon g-2 Theory Initiative, we provide an update of a new physics (NP) model recently proposed to explain the discrepancies observed between the measured values and the SM predictions of the AMMs of the charged leptons, a_l = (g-2)/2. In the NP model, an extra contribution to the AMMs arises in the presence of a scalar Inflaton triplet field, whose neutral component has a non-zero vacuum expectation value and is coupled to the gravitational background of de Sitter (dS) spacetime. In electroweak quantum corrections to (g-2) induced by the exchange of virtual W bosons and neutrinos, the latter are supposed to acquire a small Majorana mass by their interaction with the neutral component of the Inflaton field. Owing to the indirect coupling of the charged leptons to curvature, the oscillatory motion of their spin vectors precessing in a magnetic field perturbs the spherical symmetry of dS space at the Inflaton scale, inducing a tiny change in the repulsive gravitational potential associated with the metric. This perturbation, in connection with a leptonic mass variability, ultimately affects the AMMs of the charged leptons.

Despite their foundations in classical mechanics, hydrodynamic models have experienced a resurgence in modern physics, particularly in the context of electron-phonon interactions. These "tantalizing parallels 1 " between modern physics and hydrodynamics have not, however, seen a similar resurgence in the context of atomic theory. Here, a hydrodynamic dual space is investigated as a model for electron-photon interactions across orbital transitions. A diffusive equation is derived from dimensional analysis of a solid body of arbitrary shape displacing an unspecified, fluid-like matrix. The frictional energy dissipated across the solid-fluid interface is then treated as an equivalent to electromagnetic energy (i.e., photons). This relationship is shown to correspond to the Planck-Einstein relation and suggests a hidden diffusive variable within the Planck constant with units of m 2 /s. An experimental value of this apparent constant is determined and the resulting value is used to predict a theoretical value of the muon magnetic moment anomaly. The accuracy of the resulting prediction is within 0.04 sigma of the most recent experimental value and is an improvement over the 5.2 sigma predicted via the standard model of particle physics.

We perform a likelihood analysis of the minimal anomaly-mediated supersymmetry-breaking (mAMSB) model using constraints from cosmology and accelerator experiments. We find that either a wino-like or a Higgsinolike neutralino LSP, χ 0 1 , may provide the cold dark matter (DM), both with similar likelihoods. The upper limit on the DM density from Planck and other experiments enforces m χ 0 1 3 TeV after the inclusion of Sommerfeld enhancement in its annihilations. If most of the cold DM density is provided by the χ 0 1 , the measured value of the Higgs mass favours a limited range of tan β ∼ 5 (and also for tan β ∼ 45 if μ > 0) but the scalar mass m 0 is poorly constrained. In the wino-LSP case, m 3/2 is constrained to about 900 TeV and m χ 0 1 to 2.9 ± 0.1 TeV, whereas in the Higgsino-LSP case m 3/2 has just a lower limit 650 TeV ( 480 TeV) and m χ 0 1 is constrained to 1.12 (1.13) ± 0.02 TeV in the μ > 0 (μ < 0) scenario. In neither case can the anomalous magnetic moment of the muon, (g -2) μ , be improved significantly relative to its Standard Model

To find an expression for magnetic field at an arbitrary point {P} in the 3-D space, due an circularly current carrying loop.
We will take help of the use of spherical polar coordinates, and vectors.
Using the Biot-Savart law equation for magnetic field due to constant stable current carrying conductor.

A system of two fermions with different masses and interacting by the Coulomb potential is presented in a completely covariant framework. The spin-spin interaction, including the anomalous magnetic moments of the two fermions, is added by means of a Breit term. We solve the resulting fourth order differential system by evaluating the spectrum and the eigenfunctions. The interaction vertex with an external electromagnetic field is then determined. The relativistic eigenfunctions are used to study the photon emission from a hyperfine transition and are checked for the calculation of the Lamb shift due to the electron vacuum polarization in the muonic Hydrogen.

In this paper, we calculate the effective action for neutral particles with anomalous magnetic moment in an external magnetic and electric field. We show that we can take advantage from the Foldy–Wouthuysen transformation (FWT) for such systems, determined in our previous works: indeed, by this transformation we have explicitly evaluated the diagonalized Hamiltonian, allowing to present a closed form for the corresponding effective action and for the partition function at finite temperature from which the thermodynamical potentials can be calculated.

In this paper we evaluate the expression for the Green function of a pseudo-classical spinning particle interacting with constant electromagnetic external fields by taking into account the anomalous magnetic and electric moments of the particle. The spin degrees of freedom are described in terms of Grassmann variables and the evolution operator is obtained through the Fock-Schwinger proper time method.

The recent results of the LHC search for electroweak production of supersymmetric (SUSY) particles at √ s = 13 TeV have shown improved lower limits for their masses. In addition, the projected experiment E989 will be able to measure the muon anomalous magnetic moment precisely so that the experimental uncertainty can be reduced by a factor of four. It was pointed out that if the center value of the muon g -2 remains unchanged the deviation between the standard model (SM) prediction and the experimental value will be as large as 7.0σ. Such a large deviation will be solid evidence for new physics beyond the SM. Motivated by these results, we investigate the minimal SUSY extension of the SM with universal gaugino masses at the grand unified scale in the light of the muon g -2 and the updated LHC constraints. The squarks are assumed to be heavy and decoupled from physics at low energy scales to resemble the SM-like Higgs boson mass of 125 GeV and other bounds for squark masses at the LHC. We have pinned down allowed windows for the lightest neutralino and the smuon masses as well as other input parameters relevant to the light SUSY sector. The expected results of the E989 experiment play a crucial role in narrowing these windows. The viability of the model for small mass regions can be tested at the LHC Run 3 and the High Luminosity LHC in the near future.

The Born scattering amplitude of a non-relativistic spin one-half particle in an Aharonov-Bohm potential is calculated up to second order. It is demonstrated that perturbation theory works well for this model, in contrast with the case of scalar particles, thanks to the spin-magnetic moment interaction term. The first order amplitude is shown to coincide with the exact amplitude when expanded to the same order; the second order amplitude is finite and null. The polarized scattering cross section is found to be different from the unpolarized one only if the incident particle has a spin component perpendicular to the flux tube.

The detection of ultralight dark matter through interactions with nucleons, electrons, and photons has been explored in depth. In this work we propose to use precision muon experiments, specifically muon g-2 and electric dipole moment measurements, to detect ultralight dark matter that couples predominantly to muons. We set direct, terrestrial limits on DM-muon interactions using existing g-2 data, and show that a time-resolved reanalysis of ongoing and upcoming precession experiments will be sensitive to dark matter signals. Intriguingly, we also find that the current muon g-2 anomaly can be explained by a spin torque applied to muons from a pseudoscalar dark matter background that induces an oscillating electric dipole moment for the muon. This explanation may be verified by a time-resolved reanalysis.

Quantum Electrodynamics (QED) is considered the most accurate theory in the history of science. However, this precision is limited to a single experimental value: the anomalous magnetic moment of the electron (g-factor). The calculation of the electron g-factor was carried out in 1950 by Karplus and Kroll. Seven years later, Petermann detected and corrected a serious error in the calculation of a Feynman diagram; however, neither the original calculation nor the subsequent correction was ever published. Therefore, the entire prestige of the QED depends on the calculation of a single Feynman diagram (IIc) that has never been published and cannot be independently verified.

Quantum Electrodynamics (QED) is considered the most accurate theory in the history of science. However, this precision is limited to a single experimental value: the anomalous magnetic moment of the electron (g-factor). The calculation of the electron g-factor was carried out in 1950 by Karplus and Kroll. Seven years later, Petermann detected and corrected a serious error in the calculation of a Feynman diagram; however, neither the original calculation nor the subsequent correction was ever published. Therefore, the entire prestige of the QED depends on the calculation of a single Feynman diagram (IIc) that has never been published and cannot be independently verified.

Quantum electrodynamics (QED) is considered the most accurate theory in the history of science. However, this precision is based on a single experimental value: the anomalous magnetic moment of the electron (g-factor). An examination of the history of QED reveals that this value was obtained in a very suspicious way. These suspicions include the case of Karplus & Kroll, who admitted to having lied in their presentation of the most relevant calculation in the history of QED. As we will demonstrate in this paper, the Karplus & Kroll affair was not an isolated case, but one in a long series of errors, suspicious coincidences, mathematical inconsistencies and renormalized infinities swept under the rug.

We find self-dual vortex solutions in a Maxwell–Chern–Simons model with anomalous magnetic moment. From a recently developed N=2 supersymmetric extension, we obtain the proper Bogomol&#39;nyi equations together with a Higgs potential allowing both topological and nontopological phases in the theory.

A light CP-even Higgs boson with a mass of around 10 GeV could explain the recent BNL measurement of the muon anomalous magnetic moment. This observation is based on a general CP-conserving two Higgs doublet extension of the Standard Model with no tree-level flavor changing neutral current couplings. The Higgs mass is constrained by experiments at CESR and LEP to be less than twice the lightest B-meson mass and greater than (roughly) the Upsilon mass. It may be possible to exclude or discover such a Higgs boson by fully analyzing the existing LEP data.

Section based in Refs. . 2 The structure constants f abc are defined from [t a , t b ] = if abc t c . 1.3. Low energy QCD: χPT 3 i.e. for n f < 11 2 N c < 17, deserving a Nobel prize in 2004 to D. J. Gross, H. D. Politzer and F. Wilczek 3 . This sign implies the decreasing of the strong coupling constant at high energies -asymptotic freedom-and allows for an easy and standard perturbative expansion in terms of quarks and gluons degrees of freedom. This property will be used in Section 1.6.1 to derive the high energy behavior for the pseudoscalar transition form factors (TFFs). In contrast, at low energies α s increases, leading to a non-perturbative behavior and a strong-coupling regime, which is thought to be responsible for confinement, this is, the fact that free quarks and gluons are not observed in nature; instead, they bind together to form color-singlet states known as hadrons -the pions and proton among them. It must be emphasized at this point that confinement cannot be strictly explained on the basis of Eq. (1.4), which is based on a perturbative calculation. Indeed, describing confinement represents a still unsolved major theoretical challenge in mathematical physics as formulated for instance by the Clay Math institute . Describing QCD at low-energies therefore represents a formidable task. So far, a first principles calculation based on Eq. (1.1) has only been achieved through Lattice QCD [30], an expensive computational numerical method based on the ideas from K. Wilson [31] consisting in a four dimensional euclidean space-time discretization of the QCD action. Additional, Dyson-Schwinger equations provides for a continuum non-perturbative approach to quantum field theories, which have been solved within some further approximation schemes. However, even if lattice calculations have shown a tremendous progress in the recent years, not all type of observables are at present accessible in lattice QCD. Furthermore, they are extremely costly and require some guidance when performing the required extrapolations. A viable and successful analytic approach comes by the hand of χPT, the low-energy effective field theory of QCD. At the Lagrangian level, Eq. (1.1) is invariant by construction under Lorentz and local SU (3) c transformations. Eq. (1.1) is invariant too under the discrete charge conjugation (C), parity (P ), and time reversal (T ) transformations. In addition, there exists on top an almost-exact accidental symmetry which is not obvious or explicit in the construction, this is, the chiral symmetry; using the left-handed P L = 1-γ 5 2 and right-handed P R = 1+γ 5 2

The radiative corrections to double-Dalitz $({P\rightarrow\overline ll\overline l&#39;l&#39;})$ decays are revisited and completed up to next-to-leading order in QED, finding mild differences with respect to previous studies. These might be relevant for extracting information about the mesons transition form factors, which play an important role in determining the hadronic light-by-light contribution to the anomalous magnetic moment of the muon.

We present our recent results on the hadronic light-by-light pseudoscalar-exchange contribution to the anomalous magnetic moment of the muon using rational approximants. Our work provides a generalization of Padé approximants to the bivariate case to describe the most general doubly-virtual transition form factor, which is required in the calculation. This method provides a powerful tool to systematically implement the known experimental data on transition form factors in the space-like region and low energies in a model-independent way. Given the lack of experimental data on the doubly-virtual transition form factor, we make use of the pseduoscalar decays into lepton pairs. We find an interesting and puzzling situation which calls for new experimental measurements to clarify the present state.

We discuss the prospects for improving the precision on the hadronic corrections to the anomalous magnetic moment of the muon, and the plans of the Muon g -2 Theory Initiative to update the Standard Model prediction. Prospects for precise predictions of a µ in the SM Contribution Value ×10 11 References Experiment (E821 + E989) 116 592 061(41) Refs.

We review the present status of the Standard Model calculation of the anomalous magnetic moment of the muon. This is performed in a perturbative expansion in the fine-structure constant α and is broken down into pure QED, electroweak, and hadronic contributions. The pure QED contribution is by far the largest and has been evaluated up to and including O(α 5 ) with negligible numerical uncertainty. The electroweak contribution is suppressed by (m µ /M W ) 2 and only shows up at the level of the seventh significant digit. It has been evaluated up to two loops and is known to better than one percent. Hadronic contributions are the most difficult to calculate and are responsible for almost all of the theoretical uncertainty. The leading hadronic contribution appears at O(α 2 ) and is due to hadronic vacuum polarization, whereas at O(α 3 ) the hadronic light-by-light scattering contribution appears. Given the low characteristic scale of this observable, these contributions have to be calculated with nonperturbative methods, in particular, dispersion relations and the lattice approach to QCD. The largest part of this review is dedicated to a detailed account of recent efforts to improve the calculation of these two contributions with either a data-driven, dispersive approach, or a first-principle, lattice-QCD approach. The final result reads a SM µ = 116 591 810(43) × 10 -11 and is smaller than the Brookhaven measurement by 3.7σ. The experimental uncertainty will soon be reduced by up to a factor four by the new experiment currently running at Fermilab, and also by the future J-PARC experiment. This and the prospects to further reduce the theoretical uncertainty in the near future-which are also discussed here-make this quantity one of the most promising places to look for evidence of new physics.

We employ a mathematical framework based on rational approximants in order to calculate meson form factors. The method profits from unitary, is systematic and data based, and is able to ascribe a systematic uncertainty which provides for the desired model independence. Two examples are discussed: the transition form factor entering the pseudoscalar-pole piece of the hadronic lightby-light contribution to the anomalous magnetic moment of the muon, and the B → π form factor participating the B → π ν differential branching ratios which allows to determine the |V ub | CKM parameter.

We present our model-independent and data-driven method to describe pseudoscalar meson transition form factors in the space-and (low-energy) time-like regions. The method is general and conforms a toolkit applicable to any other form factor, of one and two variables, with the potential to include both high-and low-energy QCD constraints altogether. The method makes use of analyticity and unitary properties of form factors, it is simple, systematic and can be improved upon by including new data. In the present discussion, the method is used to show the impact of experimental data for precision calculations in the low-energy sector of the Standard Model. In particular, due to its relevance for New Physics searches, we have considered the hadronic light-by-light scattering contribution to the anomalous magnetic moment of the muon (the pseudoscalar exchange contribution), the pseudoscalar decays into lepton pairs, and the determination of the mixing parameters of the η and η system. For all of them we provide the most updated results in a data-driven manner. * Invited talk at the FCCP2015 -Workshop on "Flavour changing and conserving processes," 10-12 September 2015,

The recent results of the LHC search for electroweak production of supersymmetric (SUSY) particles at √ s = 13 TeV have shown improved lower limits for their masses. In addition, the projected experiment E989 will be able to measure the muon anomalous magnetic moment precisely so that the experimental uncertainty can be reduced by a factor of four. It was pointed out that if the center value of the muon g -2 remains unchanged the deviation between the standard model (SM) prediction and the experimental value will be as large as 7.0σ. Such a large deviation will be solid evidence for new physics beyond the SM. Motivated by these results, we investigate the minimal SUSY extension of the SM with universal gaugino masses at the grand unified scale in the light of the muon g -2 and the updated LHC constraints. The squarks are assumed to be heavy and decoupled from physics at low energy scales to resemble the SM-like Higgs boson mass of 125 GeV and other bounds for squark masses at the LHC. We have pinned down allowed windows for the lightest neutralino and the smuon masses as well as other input parameters relevant to the light SUSY sector. The expected results of the E989 experiment play a crucial role in narrowing these windows. The viability of the model for small mass regions can be tested at the LHC Run 3 and the High Luminosity LHC in the near future.

A. Adelmann, 2 M. Backhaus, C. Chavez Barajas, N. Berger, T. Bowcock, C. Calzolaio, G. Cavoto, 6 R. Chislett, A. Crivellin, 8, 9 M. Daum, M. Fertl, M. Giovannozzi, G. Hesketh, M. Hildebrandt, I. Keshelashvili, A. Keshavarzi, K.S. Khaw, 14 K. Kirch, 2 A. Kozlinskiy, A. Knecht, M. Lancaster, B. Märkisch, F. Meier Aeschbacher, F. Méot, A. Nass, A. Papa, 17 J. Pretz, 18 J. Price, F. Rathmann, F. Renga, M. Sakurai, P. Schmidt-Wellenburg, ∗ A. Schöning, M. Schott, C. Voena, J. Vossebeld, F. Wauters, and P. Winter ETH Zürich, 8093 Zürich, Switzerland Paul Scherrer Institut, 5232 Villigen PSI, Switzerland University of Liverpool, Liverpool, UK PRISMA Cluster of Excellence and Institute of Nuclear Physics,

Contribution from new gauge bosons in the 3 -3 -1 models to the anomalous magnetic moment of the muon, mass difference of the kaon system and rare kaon decay are calculated and numerically estimated. Bounds on masses of new gauge bosons: bileptons and Z ′ are derived.

The functional integration method is used for studying the scattering of a scalar pion on nucleon with the anomalous magnetic moment in the framework of nonrenomalizable quantum field theory. In the asymptotic region s → ∞, |t| ≪ s the representation of eikonal type for the amplitude of pion-nucleon scattering is obtained. The anomalous magnetic moment leads to additional terms in the amplitude which describe the spin flips in the scattering process. It is shown that the renormalization problem does not arise in the asymptotic s → ∞ since the unrenomalized divergences disappear in this approximation. Coulomb interference is considered as an application.

Study of the efficacy and tolerance of Otilonium Bromide instilled locally during colonoscopy aESUME L'examen endoscopique du colon doit 6tre rdalis6 sous hypotonie pour assurer le meilleur confort au malade et une visualisation optimale ~ l'endoscopiste. Les effets syst6miques inddsirables frdquemment observ4s lors de Fadministration d'un spasmolytique intra-veineux, peuvent etre 6vit4s lorsqu'il est fait usage d'un agent local. Dans cette optique, l'instillation locale perendoscopique du bromure d'Otilonium peut constituer une alternative int6ressante. Son efficacit6 et son inocuit6 sont d6montrdes dans cette 4tude randomis6e double-aveugle versus placebo. The colonic endoscopic examination must be performed under hypotonic condition in order to assure the most confortable patient's status and the optimal visualisation for the endoscopist. In this view, local instillation of Otilonium bromide may constitute an eventual interesting alternative procedure. The efficacy and the inocuity of this drug are demonstrated in this randomised double-blind versus placebo study. INTROD UCTION-GENE, RA LITES BUTS DE L'ETUDE Dans une 6tude randomisde croisde de type double-aveugle versus placebo -et aprds accord du Comit6 d'Ethique de notre Institution -nous avons Tirds h part: D r M. DE REUCK, HOpital Universitaire Brugmann (D6partement de Gastro-Entdrologie) ULB-VUB -4, place Van-Gehuchten -B 1020 Bruxelles (Belgique).

We present results for the QED contributions to the anomalous magnetic moment of the muon containing closed electron loops. The main focus is on perturbative corrections at four-loop order where the external photon couples to the external muon. Furthermore, all four-loop contributions involving simultaneously a closed electron and tau loop are computed. In combination with our recent results on the light-by-light-type corrections (see Ref. [1]) the complete four-loop electron-loop contribution to the anomalous magnetic moment of the muon has been obtained with an independent calculation. Our calculation is based on an asymptotic expansion in the ratio of the electron and the muon mass and shows the importance of higher order terms in this ratio. We perform a detailed comparison with results available in the literature and find good numerical agreement. As a by-product we present analytic results for the on-shell muon mass and wave function renormalization constants at three-loop order including massive closed electron and tau loops, which we also calculated using the method of asymptotic expansion.

We elaborate on a recently proposed extension of the Gerasimov-Drell-Hearn (GDH) sum rule which is achieved by taking derivatives with respect to the anomalous magnetic moment. The new sum rule features a linear relation between the anomalous magnetic moment and the dispersion integral over a cross-section quantity. We find some analogy of the linearized form of the GDH sum rule with the 'sideways dispersion relations'. As an example, we apply the linear sum rule to reproduce the famous Schwinger's correction to the magnetic moment in QED from a tree-level cross-section calculation and outline the procedure for computing the two-loop correction from a one-loop cross-section calculation. The polarizabilities of the electron in QED are considered as well by using the other forward-Compton-scattering sum rules. We also employ the sum rules to study the magnetic moment and polarizabilities of the nucleon in a relativistic chiral EFT framework. In particular we investigate the chiral extrapolation of these quantities.