| 1. |
- Abelev, B., et al.
(författare)
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Performance of the ALICE experiment at the CERN LHC
- 2014
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Ingår i: International Journal of Modern Physics A. - 0217-751X. ; 29:24
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Forskningsöversikt (refereegranskat)abstract
- ALICE is the heavy-ion experiment at the CERN Large Hadron Collider. The experiment continuously took data during the first physics campaign of the machine from fall 2009 until early 2013, using proton and lead-ion beams. In this paper we describe the running environment and the data handling procedures, and discuss the performance of the ALICE detectors and analysis methods for various physics observables.
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| 2. |
- Adlarson, Patrick, et al.
(författare)
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MEASUREMENT OF THE eta -> pi(+)pi(-)pi(0) DECAY WITH WASA-at-COSY DETECTOR
- 2011
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 622-624
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Tidskriftsartikel (refereegranskat)abstract
- One of the objectives of the physics programme of the WASA-at-COSY facility is to study the isospin violating eta hadronic decays into pi(+)pi(-)pi(0) systems driven by the term of QCD Lagrangian which depends on the d and u quark mass difference. These studies can be made in terms of the Dalitz plot parameters describing the density population which is proportional to the square of the amplitude vertical bar A(x,y)vertical bar(2). This contribution describes the current status of the analysis of the eta -> pi(+)pi(-)pi(0) decay in the pd ->(3) He eta and as well in the pp -> pp eta reaction with WASA-at-COSY.
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| 3. |
- Andrés, E., et al.
(författare)
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Recent results from AMANDA
- 2001
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 16:1C, s. 1013-1015
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Tidskriftsartikel (refereegranskat)abstract
- We present results based on data taken in 1997 with the 302-PMT Antarctic Muon and Neutrino Detector Array-B10 ("AMANDA-B10") array. Atmospheric neutrinos created in the northern hemisphere are observed indirectly through their charged current interactions which produce relativistic, Cherenkov-light-emitting upgoing muons in the South Pole ice cap. The reconstructed angular distribution of these events is in good agreement with expectation and demonstrates the viability of this ice-based device as a neutrino telescope.
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| 4. |
- Aydemir, Ufuk, et al.
(författare)
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Pati-Salam unification from noncommutative geometry and the TeV-scale W-R boson
- 2016
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 31:1
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Tidskriftsartikel (refereegranskat)abstract
- We analyze the compatibility of the unified left-right symmetric Pati-Salam models motivated by noncommutative geometry and the TeV-scale right-handed W boson suggested by recent LHC data. We find that the unification/matching conditions place conflicting demands on the symmetry breaking scales and that generating the required W-R mass and coupling is nontrivial.
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| 5. |
- Aydemir, Ufuk
(författare)
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SO(10) grand unification in light of recent LHC searches and colored scalars at the TeV-scale
- 2016
-
Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 31:8
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Tidskriftsartikel (refereegranskat)abstract
- We analyze the compatibility of the recent LHC signals and the TeV-scale left right model(s) in the minimal nonsupersymmetric SO(10) framework. We show that the models in which the Higgs content is selected based on the extended survival hypothesis do not allow the W-R boson to be at the TeV-scale. By relaxing this conjecture, we investigate various scenarios where a number of colored-scalars, originated from various Pati-Salam multiplets, are light and whence they survive down to the low energies. Performing a detailed renormalization group analysis with various low-energy Higgs configurations and symmetry breaking chains, while keeping the high energy Higgs content unmodified; we find that, among a number of possibilities, the models which have a light color-triplet scalar, and its combination with a light color-sextet, particularly stand out. Although these models do allow a TeV-scale W-R boson, generating the required value of the gauge coupling g(R) at this scale is nontrivial.
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| 6. |
- Babaev, Egor
(författare)
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Nonlinear sigma model approach for phase disorder transitions in chiral Gross-Neveu, Nambu-Jona-Lasinio models and strong-coupling superconductors
- 2001
-
Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 16:7, s. 1175-1197
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Forskningsöversikt (refereegranskat)abstract
- We briefly review the nonlinear sigma model approach for the subject of increasing interest: two-step phase transitions in the Gross-Neveu and the modified Nambu-Jona-Lasinio models at low N and condensation from pseudogap phase in strong-coupling superconductors. Recent success in describing of Bose-type superconductors that possess two characteristic temperatures and a pseudogap above T, is the develop ment approximately comparable with the BCS theory. One can expect that it should have influence on high-energy physics, similar to impact of the BCS theory on this subject. Although first generalizations of this concept to particle physics were made recently, these results were not systematized. In this review we summarize this development and discuss similarities and differences of the appearance of the pseudogap phase in superconductors and the Gross-Neveu and Nambu-Jona-Lasinio-like models. We discuss its possible relevance for chiral phase transition in QCD and color superconductors. This paper is organized in three parts. In the first part, we briefly review the separation of temperatures of pair formation and pair condensation in strong-coupling and low carrier density superconductors (i.e. the formation of the pseudogap phase). The second part is a review of nonlinear sigma model approach to an analogous phenomenon in the chiral Gross-Neveu model at small N. In the third part we discuss the modified Nambu-Jona-Lasinio model where the chiral phase transition is accompanied by a formation of a phase analogous to the pseudogap phase.
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| 7. |
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| 8. |
- Badelek, B, et al.
(författare)
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The photon collider at TESLA
- 2004
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Ingår i: International Journal of Modern Physics A. - 0217-751X. ; 19:30, s. 5097-5186
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Forskningsöversikt (refereegranskat)abstract
- High energy photon colliders (gammagamma,gammae) are based on e(-)e(-) linear colliders where high energy photons are produced using Compton scattering of laser light on high energy electrons just before the interaction point. This paper is a part of the Technical Design Report of the linear collider TESLA.(1) Physics program, possible parameters and some technical aspects of the photon collider at TESLA are discussed.
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| 9. |
- Bashkanov, M., et al.
(författare)
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Low-mass pi pi enhancement in baryonic pi pi production : ABC effect revised by exclusive measurements
- 2007
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 22:2-3, s. 625-628
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Tidskriftsartikel (refereegranskat)abstract
- The ABC effect - a puzzling threshold enhancement in the ππ invariant mass spectrum of double-pionic fusion to nuclear bound states - has been investigated since 40 years by inclusive measurements without providing a conclusive interpretation. First exclusive measurements to this topic have now been carried out at CELSIUS-WASA. They confirm a huge ππ threshold enhancement, prove it to be of scalar-isoscalar nature, i.e., a σ-channel phenomenon and reveal the theoretically predicted high-mass enhancement in inclusive spectra to be of πππ rather than of ππ nature - falsifying thus corresponding model predictions for the ABC effect. From the kinematically complete data samples we infer that the interaction between the two Δ particles created in this process is of crucial importance.
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| 10. |
- Bashkanov, M., et al.
(författare)
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WHAT IS THE NATURE OF THE ABC EFFECT?
- 2011
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 627-629
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Tidskriftsartikel (refereegranskat)abstract
- The ABC effect - an intriguing low-mass enhancement in the pi pi invariant mass spectrum - is known from inclusive measurements of two-pion production in nuclear fusion reactions. Exclusive measurements have been carried out at CELSIUS/WASA and WASA-at-COSY for the fusion reactions leading to d, (3)He and (4)He. They all reveal this effect to be of isoscalar nature and associated with a narrow Lorentzian-shaped structure in the total cross section. The latter could point to the formation of an isoscalar resonance, which couples to the pn channel as well as to an intermediate Delta Delta state.
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| 11. |
- Bergqvist, Göran
(författare)
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Causal tensors and simple forms
- 2002
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 17:20, s. 2748-2748
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Tidskriftsartikel (refereegranskat)
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| 12. |
- Berlowski, Marcin, et al.
(författare)
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SEARCH FOR EXOTIC EFFECTS IN eta MESON LEPTONIC DECAYS
- 2011
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 630-631
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Tidskriftsartikel (refereegranskat)abstract
- The search for the decay eta -> e(+)e(-) was carried out using the WASA detector at the COSY storage ring. Data were taken during a two week experimental run in Sept-Nov 2008 in which about 10(7) eta mesons were collected from the reaction of pp -> pp eta at energy of 1.4 GeV. Background studies were performed for several different reactions. The performance of the WASA detector for the measurement of electron-positron pairs based on the single Dalitz decay of the eta meson was studied. We also identified a statistically significant data sample of other more frequent leptonic decays.
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| 13. |
- Bijnens, Johan
(författare)
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Chiral Lagrangians
- 2002
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Ingår i: INTERNATIONAL JOURNAL OF MODERN PHYSICS A. - 0217-751X. ; 17:23, s. 3154-3169
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Konferensbidrag (refereegranskat)abstract
- An overview of the field of Chiral Lagrangians is given. This includes Chiral Perturbation Theory and resummations to extend, it to higher energies, applications to the muon anomalous magnetic moment, epsilon(1)/epsilon and others.
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| 14. |
- Bordag, Ljudmila A.
(författare)
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Symmetry reductions and exact solutions for nonlinear diffusion equations
- 2009
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Ingår i: International Journal of Modern Physics A. - Singapore : World Scientific. - 0217-751X .- 1793-656X. ; 24:8/9, s. 1713-1716
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Tidskriftsartikel (refereegranskat)abstract
- The symmetry properties of nonlinear diffusion equations are studied using a Lie group analysis. Reductions and families of exact solutions are found for some of these equations.© 2009 World Scientific Publishing Company.
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| 15. |
- Bordag, Michael, et al.
(författare)
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Analytic corrections to the electromagnetic casimir interaction between a sphere and a plate at shortdistances
- 2010
-
Ingår i: International Journal of Modern Physics A. - Singapore : World Scientific. - 0217-751X .- 1793-656X. ; 25:11, s. 2171-2176
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Tidskriftsartikel (refereegranskat)abstract
- For the vacuum interaction of asphere in front of a plane,both obeying conductor boundary conditions, we consider the approximation of small separation. We derive the next-to-leading order of the asymptotic expansion in the separation-to-radius ratio epsilon. This correction is of order epsilon. In opposite to the scalar cases it contains also contributions proportional to logarithms in first and second order, epsilon ln epsilon and epsilon(ln epsilon)(2). We compare this result with the available findings of numerical and experimental approaches.
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| 16. |
- Bordag, Michael, et al.
(författare)
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Beyond proximity force approximation in the casimir effect
- 2009
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Ingår i: International Journal of Modern Physics A. - Singapore : World Scientific. - 0217-751X .- 1793-656X. ; 24:8-9, s. 1743-1747
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Tidskriftsartikel (refereegranskat)abstract
- We compare the analytical and numerical results for the Casimir force for the configuration of a plane and a cylinder in front of a plane. While for Dirichlet boundary conditions on both, plane and sphere or cylinder, agreement is found, for Neumann boundary conditions on either the plane or one of the two, cylinder or sphere, disagreement is found. This holds, for a sphere, also for different boundary conditions on the interacting surfaces. From recent, new numerical results for the cylinder, a general appearance of logarithmic contributions beyond PFA can be predicted.
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| 17. |
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| 18. |
- Brink, Lars, 1943
(författare)
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Stanley Mandelstam and me and life on the light-cone
- 2017
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Ingår i: International Journal of Modern Physics A. - 0217-751X. ; 32:1
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Tidskriftsartikel (refereegranskat)abstract
- Stanley Mandelstam has always been one of my heroes in physics. Here I will describe my meetings with Stanley over the years and how our respective work sometimes coincided.
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| 19. |
- Carlson, Per
(författare)
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PAMELA science
- 2005
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 20:29, s. 6731-6734
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Tidskriftsartikel (refereegranskat)abstract
- The PAMELA satellite-borne experimenti, to be launched in 2005, is a powerful spectrometer including a magnetic field tracker and particle identification detectors. PAMELA science is broad and includes studies of interstellar propagation, solar modulation and search for dark matter signals.
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| 20. |
- Di Vecchia, Paolo
(författare)
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My interaction with Stanley
- 2017
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Ingår i: International Journal of Modern Physics A. - : World Scientific. - 0217-751X .- 1793-656X. ; 32:12
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Tidskriftsartikel (refereegranskat)
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| 21. |
- Dunin-Barkowski, Petr, et al.
(författare)
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Evolution for Khovanov polynomials for figure-eight-like family of knots
- 2022
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Ingår i: International Journal of Modern Physics A. - : World Scientific Pub Co Pte Ltd. - 0217-751X .- 1793-656X. ; 37:36
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Tidskriftsartikel (refereegranskat)abstract
- We look at how evolution method deforms, when one considers Khovanov polynomials instead of Jones polynomials. We do this for the figure-eight-like knots (also known as 'double braid' knots, see arXiv:1306.3197) -- a two-parametric family of knots which "grows" from the figure-eight knot and contains both two-strand torus knots and twist knots. We prove that parameter space splits into four chambers, each with its own evolution, and two isolated points. Remarkably, the evolution in the Khovanov case features an extra eigenvalue, which drops out in the Jones (t -> -1) limit.
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| 22. |
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| 23. |
- Euler, Marianna, et al.
(författare)
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Explicitly space- and time-dependent d'Alembert equations with symmetries
- 1999
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 14:26, s. 4189-4200
-
Tidskriftsartikel (refereegranskat)abstract
- The general d'Alembert equation $\square u+ f(x_0, x_1,u)= 0$ is considered, where $\square$ is the two-dimensional d'Alembert operator. We classify the equation for functions $f$ by which it admits several Lie symmetry algebras, which include the Lorentz symmetry generator. The corresponding symmetry reductions are listed.
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| 24. |
- Fransson, Kjell
(författare)
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Status of wasa at cosy
- 2007
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 22:2-3, s. 570-573
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Tidskriftsartikel (refereegranskat)abstract
- The WASA detector built and operated at the storage ring CELSIUS in Uppsala, was during 2005 moved to the COoler SYnchrotron COSY in Julich where it is now being reassembled. The main physics concerns decays of eta and eta' mesons and isospin violation in deuteron-deuteron interactions. Several modifications and upgrades are planned to adapt the WASA detector to the COSY environment and beam energy. The first commissioning run is scheduled to start August 2006. Here we report on the status of the installation work and upgrades planned for the WASA detector at COSY.
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| 25. |
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| 26. |
- Grosse, Harald, et al.
(författare)
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The geometric phase and the Schwinger term in some models
- 1992
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Ingår i: International Journal of Modern Physics A. - : World Scientific. - 0217-751X .- 1793-656X. ; 7:21, s. 5045-5083
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Forskningsöversikt (refereegranskat)abstract
- We discuss the quantization of fermions interacting with external fields and observe the occurrence of equivalent as well as inequivalent representations of the canonical anticommutation relations. Implementability of gauge and axial gauge transformations leads to generators which fulfil an algebra of current with a Schwinger term. This term can be written as a cocycle and leads to the boson-fermion correspondence.Transport of a quantum-mechanical system along a closed loop of parameter space may yield a geometric phase. We discuss models for which nonintegrable phase factors are obtained from the adiabatic parallel transport. After second quantization, one obtains, in addition, a Schwinger term. Depending on the type of transformation, a subtle relationship between these two obstructions can occur. We indicate finally how we may transport density matrices along closed loops in parameter space.
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| 27. |
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| 28. |
- Hejny, Volker, et al.
(författare)
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CHARGE SYMMETRY BREAKING IN dd -> (4)He pi(0) WITH WASA-at-COSY
- 2011
-
Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 595-597
-
Tidskriftsartikel (refereegranskat)abstract
- Charge symmetry breaking effects can be used as an experimental tool to study quark mass effects. Using recent high precision data from TRIUMF and IUCF an international theory collaboration is working on a consistent description within the framework of chiral pertubation theory. The WASA-at-COSY collaboration has started an experimental program extending the studies on the reaction dd -> (4)He pi(0) towards higher excess energies in order to provide necessary information on the contribution of p-waves. First preliminary results on the total cross section at Q = 60 MeV are presented.
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| 29. |
- Hodana, Malcorzata, et al.
(författare)
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STUDY OF THE eta -> gamma e(+)e(-) DECAY WITH THE WASA-at-COSY
- 2011
-
Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 650-651
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Tidskriftsartikel (refereegranskat)abstract
- In October 2008, the WASA-at-COSY collected more than 10(7) events for the pd -> (3)He eta reaction. The aim is the determination of the invariant mass of the lepton pairs created in the Dalitz decay eta -> gamma e(+)e(-). The e(+)e(-) invariant mass spectrum is directly related to the distribution of the four-momentum squared of the virtual photon from the eta -> gamma gamma* process and hence it allows for the study of the transition form factor which in turn reflects the structure of the decaying meson.
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| 30. |
- Jany, Anna, et al.
(författare)
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STUDIES OF MESON PRODUCTION AND DECAYS IN pd -> (3)He X WITH WASA-at-COSY
- 2011
-
Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 652-653
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Tidskriftsartikel (refereegranskat)abstract
- Studies of meson production in the pd -> (3)He X reaction, where X = eta, eta' and omega, and their decays are investigated with the WASA-at-COSY facility. The angular distribution of the eta in the center of mass of the (3)He-eta system, have been measured at an excess energy of Q = 61 MeV over the full angular range. The anisotropy expected at the relatively large Q is observed.
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| 31. |
- Jany, Benedykt R., et al.
(författare)
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LEADING MODES OF 3 pi(0) PRODUCTION IN PROTON-PROTON COLLISIONS AT INCIDENT PROTON MOMENTUM 3.35 GeV/c
- 2011
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 654-655
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Tidskriftsartikel (refereegranskat)abstract
- For the first time pp -> pp3 pi(0) has been measured at an incident proton momentum of P(b)=3.35GeV/c. The total cross section has been determined. The reaction mechanism is studied by a Dalitz plot analyses, which indicate that the leading production and decay mechanism is closely related to the simultaneous excitation of Delta(1232) and N*(1440) baryon resonances.
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| 32. |
- Khakimova, O., et al.
(författare)
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Observation of the abc effect in the first exclusive measurements of pn -> d pi(0)pi(0)
- 2007
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 22:2-3, s. 617-620
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Tidskriftsartikel (refereegranskat)abstract
- The reaction pn → dπ0π0 constitutes the most fundamental system for the study of the ABC effect - a puzzling threshold enhancement in the ππ invariant mass spectrum of the ππ system in double-pionic fusion to nuclear bound states. The first exclusive measurements of this reaction have now been carried out at CELSIUS-WASA. They exhibit a striking low-mass enhancement in the ππ invariant mass spectrum, prove it to be a σ-channel phenomenon and falsify conventional theoretical models, which predict an associated high-mass enhancement not present in the new exclusive data. In the kinematically complete data sample we observe a ΔΔ excitation, where the interaction between the two Δ obviously plays a crucial role for the generation of the ππ low-mass enhancement.
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| 33. |
- KHARCHEV, S, et al.
(författare)
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GENERALIZED KAZAKOV-MIGDAL-KONTSEVICH MODEL - GROUP-THEORY ASPECTS
- 1995
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Ingår i: INTERNATIONAL JOURNAL OF MODERN PHYSICS A. - : WORLD SCIENTIFIC PUBL CO PTE LTD. - 0217-751X. ; 10:14, s. 2015-2051
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The Kazakov-Migdal model, if considered as a functional of external fields, can always be represented as an expansion over characters of the GL group. The integration over ''matter fields'' can be interpreted as going over the model (the space of all high
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| 34. |
- Khrennikov, Andrei
(författare)
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Towards a wave resolution of the wave-particle duality
- 2014
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 29:31, s. 1450185-
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Tidskriftsartikel (refereegranskat)abstract
- We developed a purely field model of microphenomena-prequantum classical statistical field theory (PCSFT). This model reproduces important probabilistic predictions of QM including correlations for entangled systems. Hence, the wave-particle duality can be resolved in favor of a purely wave model. In PCSFT "particles" are just clicks of detectors.
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| 35. |
- Kren, F., et al.
(författare)
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THE pp -> d pi(+)pi(0) REACTION - A CASE OF Delta Delta EXCITATION WITHOUT ABC-EFFECT
- 2009
-
Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 24:2-3, s. 561-563
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Tidskriftsartikel (refereegranskat)abstract
- The ABC effect, a low-mass enhancement in the invariant pp mass, is observed in double-pionic fusion reactions leading to a bound nuclear system in the final state. From previous measurements there have been indications that this phenomenon is resctricted to the sigma channel of the pp system. With exclusive measurements of the pp -> d pi(+)pi(0) reaction at T-p = 1.1 GeV we demonstrate that, indeed, the ABC effect does not occur in the vector-isovector Delta Delta channel (rho channel) despite the fact that the Delta Delta excitation is oberved to be the dominant reaction process. We also show that this reaction is well described by a t-channel Delta Delta excitation with the subsequent decay into the vector-isovector Delta Delta channel given by the rho channel operator.
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| 36. |
- Kuksa, V. I., et al.
(författare)
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Mass shell smearing effects in top pair production
- 2012
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Ingår i: International Journal of Modern Physics A. - 0217-751X. ; 27:13
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Tidskriftsartikel (refereegranskat)abstract
- The top quark pair production and decay are considered in the framework of the smeared-mass unstable particles model. The results for total and differential cross-sections in vicinity of t (t) over bar threshold are in good agreement with the previous ones in the literature. The strategy of calculations of the higher order corrections in the framework of the model is discussed. Suggested approach significantly simplifies calculations compared to the standard perturbative one and can serve as a convenient tool for fast and precise preliminary analysis of processes involving intermediate timelike top quark exchanges in the near-threshold region.
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| 37. |
- Kupsc, Andrzej
(författare)
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Recent results from the WASA-at-COSY experiment : Light meson decays
- 2011
-
Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 474-479
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Forskningsöversikt (refereegranskat)abstract
- Studies of light meson decays are the key experiments for the WASA detector at COSY-Julich. One of the world largest data samples of the eta meson decays have been recently collected in the pd -> He-3 eta and in the pp -> pp eta reactions. The status of the analysis of various decay channels and the further plans for the light meson decay program are presented.
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| 38. |
- Liu, Xue-Wen, et al.
(författare)
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Texture zeros for dirac neutrinos and current experimental tests
- 2013
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 28:12, s. 1350040-
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Tidskriftsartikel (refereegranskat)abstract
- The Daya Bay and RENO reactor neutrino experiments have revealed that the smallest neutrino mixing angle is in fact relatively large, i.e. theta(13) approximate to 9 degrees. Motivated by this exciting progress, we perform a systematic study of the neutrino mass matrix M-nu with one or two texture zeros, in the assumption that neutrinos are Dirac particles. Among 15 possible patterns with two texture zeros, only three turn out to be favored by current neutrino oscillation data at the 3 sigma level. Although all the six patterns with one texture zero are compatible with the experimental data at the 3 sigma level, the parameter space of each pattern is strictly constrained. Phenomenological implications of M-nu on the leptonic CP violation and neutrino mass spectrum are explored, and the stability of texture zeros against the radiative corrections is also discussed.
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| 39. |
- Ma, Chen-Te, et al.
(författare)
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Integrability and spectral form factor in Chern-Simons formulation
- 2020
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Ingår i: International Journal of Modern Physics A. - : World Scientific Pub Co Pte Lt. - 0217-751X .- 1793-656X. ; 35:24
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Tidskriftsartikel (refereegranskat)abstract
- We study the integrability from the spectral form factor in the Chern-Simons formulation. The effective action in the higher spin sector was not derived so far. Therefore, we begin from the SL(3) Chern-Simons higher spin theory. Then the dimensional reduction in this Chern-Simons theory gives the SL(3) reparametrization invariant Schwarzian theory, which is the boundary theory of an interacting theory between the spin-2 and spin-3 fields at the infrared or massless limit. We show that the Lorentzian SL(3) Schwarzian theory is dual to the integrable model, SL(3) open Toda chain theory. Finally, we demonstrate the application of open Toda chain theory from the SL(2) case. The numerical result shows that the spectral form factor loses the dip-ramp-plateau behavior, consistent with integrability. The spectrum is not a Gaussian random matrix spectrum. We also give an exact solution of the spectral form factor for the SL(3) theory. This solution provides a similar form to the SL(2) case for beta not equal 0. Hence the SL(3) theory should also do not have a Gaussian random matrix spectrum.
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| 40. |
- Nasir, SM
(författare)
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Bogomol'nyi vortices from Seiberg-Witten monopoles
- 1999
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Ingår i: INTERNATIONAL JOURNAL OF MODERN PHYSICS A. - : WORLD SCIENTIFIC PUBL CO PTE LTD. - 0217-751X. ; 14:24, s. 3905-3920
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The Seiberg-Witten monopole equations are studied on manifolds of type X = Sigma x S-2, where Sigma is a Riemann surface of genus g > 1. Imposing spherical symmetry on the monopole equations, Bogomol'nyi vortices on Sigma are obtained. The dimensions of t
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| 41. |
- Pasechnik, Roman, et al.
(författare)
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Composite scalar dark matter from vector-like SU (2) confinement
- 2016
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Ingår i: International Journal of Modern Physics A. - 0217-751X. ; 31:8
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Tidskriftsartikel (refereegranskat)abstract
- A toy-model with SU(2)TC dynamics confined at high scales ΛTC > 100GeV enables to construct Dirac UV completion from the original chiral multiplets predicting a vector-like nature of their weak interactions consistent with electroweak precision tests. In this work, we investigate a potential of the lightest scalar baryon-like (T-baryon) state B0 = UD with mass mB ≥ 1TeV predicted by the simplest two-flavor vector-like confinement model as a dark matter (DM) candidate. We show that two different scenarios with the T-baryon relic abundance formation before and after the electroweak (EW) phase transition epoch lead to symmetric (or mixed) and asymmetric DM, respectively. Such a DM candidate evades existing direct DM detection constraints since its vector coupling to Z boson absents at tree level, while one-loop gauge boson mediated contribution is shown to be vanishingly small close to the threshold. The dominating spin-independent (SI) T-baryon-nucleon scattering goes via tree-level Higgs boson exchange in the t-channel. The corresponding bound on the effective T-baryon-Higgs coupling has been extracted from the recent LUX data and turns out to be consistent with naive expectations from the light technipion case mπ <ΛTC. The latter provides the most stringent phenomenological constraint on strongly-coupled SU(2)TC dynamics so far. Future prospects for direct and indirect scalar T-baryon DM searches in astrophysics as well as in collider measurements have been discussed.
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| 42. |
- Pasechnik, Roman, et al.
(författare)
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Spin effects in diffractive charmonia production
- 2011
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 583-585
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Tidskriftsartikel (refereegranskat)abstract
- We consider exclusive double diffractive production of polarised axial-vector chi(c)(1(+)) and tensor chi(c)(2(+)) charmonia in proton-(anti)proton collisions at Tevatron energy. The corresponding amplitudes for these processes are derived within the k(t)-factorisation approach. Contributions from different polarisation states of axial-vector and tensor charmonia are quantified. Corresponding experimental consequences are discussed.
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| 43. |
- Petrén, Henrik
(författare)
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eta MESON PRODUCTION IN PROTON-PROTON COLLISIONS AT 40 AND 72 MeV EXCESS ENERGY
- 2011
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 681-682
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Tidskriftsartikel (refereegranskat)abstract
- Differential cross sections for eta production in proton-proton collisions at 40 and 72 MeV above threshold show that higher partial waves are necessary to describe the reaction. A simple model assuming constant production amplitudes and including most partial waves up to two units of angular momentum reproduces the data rather well, and also describes the invariant mass distributions found at 15.5 MeV excess energy.
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| 44. |
- Pettersson, Henrik, et al.
(författare)
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eta PRODUCTION IN PROTON-PROTON COLLISIONS AT 72 MeV EXCESS ENERGY
- 2009
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 24:2-3, s. 446-449
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Tidskriftsartikel (refereegranskat)abstract
- The production of eta mesons at an excess energy of 72 MeV has been studied in the reaction pp -> pp(eta)gamma gamma. It is shown that a simple model with Pp. final states included reproduces observed differential distributions better than the same model restricted to Ss, Sd and Ds final states. The strong influence of the Pp states could be taken as an indication of rho dominance within an one boson exchange model for the excitation of N*(1535).
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| 45. |
- Podkopal, Pawel, et al.
(författare)
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INVESTIGATION OF THE CHARGE SYMMETRY CONSERVING REACTION dd -> (3)He n pi(0) WITH WASA-at-COSY
- 2011
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 598-600
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Tidskriftsartikel (refereegranskat)abstract
- One of the key experiments of the physics program of WASA-at-COSY is the determination of the p- wave contributions to the Charge Symmetry breaking amplitude in the reaction dd -> (4)He pi(0) at 1.2 GeV/c beam momentum. As a first step towards realisation of this goal the Charge Symmetry conserving reaction dd -> (3)Hen pi(0) was measured. For an overall theoretical analysis of CSB reactions in terms of Chiral Perturbation Theory this reaction channel will be used to gain information on the deuteron-deuteron initial state interaction for s- and p- wave pion production.
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| 46. |
- Pricking, A., et al.
(författare)
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The ABC Effect and its Energy Dependence in the Double-Pionic Fusion to 4He
- 2011
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 699-701
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Tidskriftsartikel (refereegranskat)abstract
- The double-pionic fusion reactions dd → 4Heπ0π0 and dd → 4Heπ+π- were measured exclusively and kinematically complete with the WASA detector at COSY. The measurements were performed in the energy range Tp = 0.8 - 1.4 GeV covering thus the full energy region, where the so-called ABC effect – a peculiar low-mass enhancement in the ππ-invariant mass spectrum – was observed previously in inclusive measurements. Our findings for the double-pionic fusion to 4He are in accordance with the observations for the basic pn → dπ0π0 reaction pointing to the same fundamental mechanism. In both cases we observe that the ABC effect is associated with a peak in the energy dependence of the total cross section. In the 4He case the peak structure in the total cross section is broadened in comparison to the deuteron case. This is consistent with both Fermi motion of the basic pn system within 4He and with collision broadening as it is known, e.g., from excitations of the Δ resonance in nuclei.
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| 47. |
- Przerwa, J., et al.
(författare)
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ISOSPIN DEPENDENCE OF THE eta ' MESON PRODUCTION IN NUCLEON-NUCLEON COLLISIONS
- 2009
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 24:2-3, s. 458-461
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Tidskriftsartikel (refereegranskat)abstract
- A comparison of the close-to-threshold total cross section for the eta' production in pp -> pp eta' and pn -> pn eta' reactions constitutes a tool to investigate the eta' meson structure and the reaction mechanism in the channels of isospin I = 0 and I = 1 and may provide insight into the flavour-singlet (perhaps also into gluonium) content of the eta' meson. In this contribution we present preliminary results of measurement of the quasifree production of the eta' meson in the proton-neutron collisions conducted using the COSY-11 facility.
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| 48. |
- Redmer, Christoph F.
(författare)
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ANALYSIS OF eta -> pi(+)pi(-)gamma MEASURED WITH THE WASA FACILITY AT COSY
- 2011
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 715-717
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Tidskriftsartikel (refereegranskat)abstract
- The decay eta -> pi(+)pi(-)gamma has been measured with the WASA facility at COSY. The largest data set taken so far in an exclusive measurement was acquired, with 13740 +/- 140 events after background subtraction. Efficiency corrected Dalitz plot distributions have been extracted, which show the importance of final state interactions for the understanding of the decay.
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| 49. |
- Sernelius, Bo E
(författare)
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GRAVITATION AS A CASIMIR EFFECT
- 2009
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Ingår i: INTERNATIONAL JOURNAL OF MODERN PHYSICS A. - 0217-751X. ; 24:8-9, s. 1804-1812
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Tidskriftsartikel (refereegranskat)abstract
- We describe how dispersion forces between two atoms in ordinary electromagnetism come about and how they may be derived. Then we introduce hypothetical particles interacting with a harmonic oscillator interaction potential. We demonstrate that in a system with this type of interacting particles the retarded dispersion interaction between composite particles varies as 1/r, i.e. just like the gravitational potential does. This demonstrates that gravitation can be a Casimir effect.
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| 50. |
- Sernelius, Bo E
(författare)
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THE THERMAL CASIMIR EFFECT: SATURATION
- 2010
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Ingår i: INTERNATIONAL JOURNAL OF MODERN PHYSICS A. - : World Scientific Publishing Co Pte Ltd. - 0217-751X. ; 25:11, s. 2319-2327
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Tidskriftsartikel (refereegranskat)abstract
- This article addresses the discrepancies between theoretical and experimental results obtained for the thermal Casimir effect. Here we test the possibility that saturation effects may be the root of the problems. We present graphs that describe the numerical derivations in great detail.
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