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76 results on '"E. van Beveren"'

1. $Z_0(57)$ and $E(38)$: possible surprises in the Standard Model

Author

George Rupp and E. van Beveren

Subjects
High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), High Energy Physics::Phenomenology, General Physics and Astronomy, Applied mathematics, FOS: Physical sciences, Mathematics, Standard model (cryptography), High Energy Physics - Experiment
Abstract

With the reported observation of the Higgs boson at the LHC, the Standard Model of particle physics seems to be complete now as for its particle content. However, several experimental data at low and intermediate energies indicate that there may be two surprises. First we propose a tentative new boson $Z_0(57)$, with a mass of about 57 GeV, on the basis of small enhancements we observe in several experiments, using recent data obtained at the LHC as well as much older ones from LEP. If confirmed, we interpret this new particle as a pseudoscalar or scalar partner of a composite $Z$ vector boson. Secondly, we advocate the existence of a very light spinless boson $E(38)$, probably a scalar, with a mass of 38 MeV and decaying into two photons. Theoretical arguments and experimental signals supporting such a novel light boson will be presented, including a recent direct experimental confirmation at the Joint Institute for Nuclear Research in Dubna., 6 pages, 5 figures; presented by G. Rupp at "Excited QCD 2020", Krynica-Zdr\'{o}j, Poland, 2-8 February 2020; accepted for publication in Acta Physica Polonica B Proc. Suppl

Published
2020

2. Modern meson spectroscopy: the fundamental role of unitarity

Author

George Rupp and E. van Beveren

Subjects
Physics, Nuclear and High Energy Physics, Meson, Unitarity, 010308 nuclear & particles physics, High Energy Physics::Lattice, Quark model, Nuclear Theory, High Energy Physics::Phenomenology, High Energy Physics - Lattice (hep-lat), FOS: Physical sciences, Particle Data Group, 01 natural sciences, Unitary state, High Energy Physics - Experiment, High Energy Physics - Phenomenology, Theoretical physics, High Energy Physics - Experiment (hep-ex), High Energy Physics - Lattice, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Bound state, High Energy Physics::Experiment, 010306 general physics, Spectroscopy
Abstract

The importance of $S$-matrix unitarity in realistic meson spectroscopy is reviewed, both its historical development and more recent applications. First the effects of imposing $S$-matrix unitarity on meson resonances is demonstrated in both the elastic and the inelastic case. Then, the static quark model is revisited and its theoretical as well as phenomenological shortcomings are highlighted. A detailed account is presented of the mesons in the tables of the Particle Data Group that cannot be explained at all or only poorly in models describing mesons as pure quark-antiquark bound states. Next the earliest unitarised and coupled-channel models are revisited, followed by several examples of puzzling meson resonances and their understanding in a modern unitarised framework. Also, recent and fully unquenched lattice descriptions of such mesons are summarised. Finally, attention is paid to production processes, which require an unconventional yet related unitary approach. Proposals for further improvement are discussed., Comment: Invited review paper, 51 pages, 16 figures, 4 tables; to be published in "Progress in Particle and Nuclear Physics" 2021. v2: several typos corrected, in particular in Eqs. (15), (17), (36), and (37) in Section 2; some accompanying remarks rephrased for clarity; Eq. (41) improved. NOTE: v3 is identical to v2; published version (in print and online) largely corresponds to v1; v3 (=v2) is correct

Published
2020
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3. Dramatic implications of unitarity for meson spectroscopy

Author

E. van Beveren and George Rupp

Subjects
Physics, High Energy Physics - Phenomenology, Particle physics, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), Meson, Unitarity, General Physics and Astronomy, FOS: Physical sciences, Spectroscopy, High Energy Physics - Experiment
Abstract

An unambiguous definition of meson resonance masses requires a description of the associated phase shifts in terms of a manifestly unitary $S$-matrix and its complex poles. However, the commonly used Breit-Wigner (BW) parametrisations can lead to appreciable deviations. We demonstrate this for a simple elastic resonance, viz. $\rho(770)$, whose pole and BW masses turn out to differ by almost 5 MeV. In the case of the very broad $f_0(500)$ and $K_0^\star(700)$ scalar mesons, the discrepancies are shown to become much larger, while also putting question marks at the listed PDG BW masses and widths. Furthermore, some results are reviewed of a manifestly unitary model for meson spectroscopy, which highlight the potentially huge deviations from static model predictions. Finally, a related unitary model for production amplitudes is shown to explain several meson enhancements as non-resonant threshold effects, with profound implications for spectroscopy., Comment: 6 pages, Acta Physica Polonica B style; Talk by G. Rupp at Workshop Excited QCD 2019, Schladming, Austria, Jan. 30 - Feb. 3, 2019. Version 2: some rephrasing on Breit-Wigner parametrisations; version accepted for publication in Acta Phys. Pol. B Proc. Suppl

Published
2019
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4. General unquenching properties of two-meson scattering and production amplitudes

Author

George Rupp and E. van Beveren

Subjects
Physics, High Energy Physics - Experiment (hep-ex), Particle physics, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Amplitude, Meson, Scattering, FOS: Physical sciences, General Physics and Astronomy, Production (economics), High Energy Physics - Experiment
Abstract

Besides the unitarity and symmetry requirements for a multi-resonance scattering amplitude, several other natural conditions can easily exclude unrealistic proposals. In particular, the behaviour of singularities under the variation of model parameters yields important information. We discuss how resonance poles should move in the complex-energy plane when coupling constants and masses are varied, how resonances above threshold can turn into bound states below threshold and how the light-quark spectrum can be turned into the spectrum of heavy quarks, with one and the same analytic expression for the scattering amplitude. Moreover, it is shown that perturbative approximations usually do not satisfy those natural conditions., Presented at Excited QCD 2017, Sintra (Portugal), 8-12 May 2017, 6 pages, plain LaTeX; minor changes to the text, one reference corrected and one reference added

Published
2017

5. The nature of σ, κ, a0(980) and f0(980)

Author

D.V. Bugg, George Rupp, E. van Beveren, and Frieder Kleefeld

Subjects
Coupling constant, Physics, Nuclear and High Energy Physics, Meson, 010308 nuclear & particles physics, Scalar (mathematics), Phase (waves), Radius, 01 natural sciences, Amplitude, Quantum electrodynamics, 0103 physical sciences, Atomic physics, 010306 general physics, Spectroscopy, Harmonic oscillator
Abstract

Masses and widths of the four light scalar mesons σ , κ , a 0 ( 980 ) and f 0 ( 980 ) may be reproduced in a model where mesons scatter via a q q ¯ loop. A transition potential is used to couple mesons to q q ¯ at a radius of ∼ 0.57 fm . Inside this radius, there is an infinite bare spectrum of confined q q ¯ states, for which a harmonic oscillator is chosen here. The coupled-channel system approximately reproduces the features of both light and heavy meson spectroscopy. The generation of σ , κ , a 0 ( 980 ) and f 0 ( 980 ) is a balance between attraction due to the q q ¯ loop and suppression of the amplitudes at the Adler zeros. Phase shifts increase more rapidly as the coupling constant to the mesons increases. This leads to resonant widths which decrease with increasing coupling constant—a characteristically non-perturbative effect.

Published
2006
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6. Continuum bound states K L , D 1(2420), D s1(2536), and their partners K S , D 1(2400), D * sJ (2463)

Author

George Rupp and E. van Beveren

Subjects
Physics, Antiparticle, Particle physics, Physics and Astronomy (miscellaneous), Meson, Unitarity, 010308 nuclear & particles physics, Coupling (probability), Quarkonium, 01 natural sciences, 0103 physical sciences, Content (measure theory), Bound state, Continuum (set theory), 010306 general physics, Engineering (miscellaneous), Mathematical physics
Abstract

The very recently observed D * sJ (2463) meson is described as a $J^{P}\! = \!1^{ + }$ $c\bar{s}$ bound state in a unitarised meson model, owing its existence to the strong OZI-allowed $^{3}\!P_{0}$ coupling to the nearby S-wave $D^{*}\!K$ threshold. By the same non-perturbative mechanism, the narrow axial-vector D s1(2536) resonance shows up as a quasi-bound-state partner embedded in the $D^{*}\!K$ continuum. With the same model and parameters, it is also shown that the preliminary broad 1 + D 1(2400) resonance and the established narrow 1 + D 1(2420) may be similar $c\bar{n}$ partners, as a result of the strong OZI-allowed $^{3}\!P_{0}$ coupling to the nearby S-wave $D^{*}\!\pi$ threshold. The continuum bound states D 1(2420) and D s1(2536) are found to be mixtures of 33% $^{3\!}P_{1}$ and 67% $^{1\!}P_{1}$ , whereas their partners D 1(2400) and D * sJ (2463) have more or less the opposite $^{2S + 1}\!P_1$ -state content, but additionally with some $D^{*}\!\pi$ or $D^{*}\!K$ admixture, respectively. The employed mechanism also reproduces the ratio of the K L -K S mass difference and the K S width, by describing K L as a bound state embedded in the $\pi\pi$ continuum. The model’s results for $J^{P}\! = \!1^{ + }$ states containing one b quark are also discussed.

Published
2004
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7. Comment on 'Understanding the scalar meson $q\bar{q}$ nonet'

Author

George Rupp and E. van Beveren

Subjects
Physics, Coupling constant, Particle physics, Physics and Astronomy (miscellaneous), Meson, High Energy Physics::Lattice, Nuclear Theory, High Energy Physics::Phenomenology, Scalar (mathematics), Quark model, Elementary particle, Quarkonium, High Energy Physics::Experiment, Symmetry breaking, Scalar meson, Engineering (miscellaneous)
Abstract

It is shown that the incomplete scalar meson nonets found by Tornqvist [1] and Tornqvist & Roos [2], employing a new version of the Helsinki unitarised quark model, should in fact be complete, including an as yet unconfirmed light $K_0^*$ below 1 GeV (old $\kappa$ ) and the established $f_0$ (1500). A detailed comparison is presented with the predictions of the Nijmegen unitarised meson model, in which two complete scalar nonets show up below 1.5 GeV [3]. The reason for the flavour-nonet breaking found in [1,2] we argue to originate in the use of coupling constants for the three-meson vertex which are not independent of flavour. Also some statements made in [1] are critically reviewed.

Published
1999
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8. Direct determination of two-pion correlations for pp→ 2π+2π− annihilation at rest

Author

Ioannis Evangelou, O. Wigger, L. Sakeliou, Per Carlson, Panagiotis Kokkas, W. Fetscher, F. Henry-Couannier, Ch Yèche, Sotirios Vlachos, G. Chardin, V.E. Markushin, M.B. Chertok, G. Backenstoss, Danilo Zavrtanik, A. Angelopoulos, H.-J. Gerber, M.P. Locher, K. Jon-And, L. Tauscher, D. Garreta, P. Weber, J. Pinto da Cunha, C. Thibault, P. Sanders, E. Machado, C. Eleftheriadis, Nikolaos Manthos, R. Gamet, A. Go, R. Le Gac, A. Liolios, O. Behnke, A.J.P.L. Policarpo, Mats Danielsson, E. Gabathuler, R. Rickenbach, P. Bargassa, Marcin Wladyslaw Wolter, E. Hubert, A. Benelli, C.W.E. van Eijk, J. Derre, F. Leimgruber, A. Schopper, Igor Mandić, M. Fidecaro, Stef. Charalambous, J. R. Fry, P. Bloch, P.J. Hayman, Jeffrey Boone Miller, A. Haselden, V. Bertin, A. Soares, D. Zimmerman, G. Polivka, Elie Aslanides, T. Ruf, Lukas A. Schaller, Michael C. Carroll, A. Apostolakis, M. Schafer, L. Faravel, C. Touramanis, R.W. Hollander, F. Blanc, Frixos A Triantis, P. Pavlopoulos, Marc Dejardin, B.L. Roberts, I. Papadopoulos, R. Kreuger, T. Schietinger, P.-R. Kettle, B. Pagels, G. Marel, A. Muller, M. Mikuž, T. Nakada, D. Francis, A. Ealet, R. Ferreira-Marques, E. Cawley, A. Cody, Andrej Filipcic, E. van Beveren, F. Touchard, João Carvalho, and F. Montanet

Subjects
Physics, Particle physics, Annihilation, Physics and Astronomy (miscellaneous), Skyrmion, Nuclear Theory, Charge (physics), Radius, Momentum, Nuclear physics, Pion, Symmetrization, Nuclear Experiment, Engineering (miscellaneous), Event (particle physics)
Abstract

We study ππ correlations in the exclusive reaction pp → 2π+2π− at rest measured by the CPLEAR experiment. Avoiding the introduction of an arbitrary reference sample, we analyse differential distributions for equal charge pion pairs removing the phase-space factor event by event. A peak at small relative momenta is most pronounced for large total momentum of the pair. The physical implications of bosonic symmetrization for the properties of the pion source, in particular its radius, are briefly discussed. The two extremes considered are the chaotic Hanbury-Brown-Twiss mechanism and the coherent Skyrmion model.

Published
1998
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9. Measurement of the CP-violation parameter η00 using tagged and K0

Author

F. Leimgruber, Lukas A. Schaller, A. Schopper, E. Hubert, R. Kreuger, L. Faravel, P.J. Hayman, R. Ferreira-Marques, O. Wigger, Ch Yèche, V. Bertin, G. Marel, Elie Aslanides, P. Pavlopoulos, A. Go, D. Zimmerman, C. Touramanis, Mats Danielsson, Frixos A Triantis, Sotirios Vlachos, Ioannis Evangelou, Andrej Filipcic, T. Ruf, R. Le Gac, W. Fetscher, L. Sakeliou, A. Angelopoulos, J. Pinto da Cunha, A. Muller, C. Thibault, A. Benelli, C.W.E. van Eijk, E. Gabathuler, R. Rickenbach, R. Gamet, Per Carlson, F. Henry-Couannier, A. Haselden, Igor Mandić, C. Eleftheriadis, P. Bloch, Nikolaos Manthos, B. L. Roberts, Panagiotis Kokkas, A. Liolios, A. Ealet, João Carvalho, F. Montanet, F. Blanc, T. Nakada, P.R. Kettle, L. Tauscher, J. R. Fry, A.J.P.L. Policarpo, R.W. Hollander, Michael C. Carroll, B. Pagels, E. Machado, T. Schietinger, Danilo Zavrtanik, M.B. Chertok, Jeffrey Boone Miller, Marc Dejardin, K. Jon-And, M. Mikuž, D. Francis, P. Sanders, M. Fidecaro, P. Weber, M. Schafer, P. Bargassa, G. Chardin, A. Apostolakis, G. Backenstoss, D. Garreta, I. Papadopoulos, Stef. Charalambous, H.-J. Gerber, G. Polivka, E. van Beveren, F. Touchard, Marcin Wladyslaw Wolter, J. Derre, E. Cawley, A. Cody, and O. Behnke

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Complete data, media_common.quotation_subject, CP violation, Asymmetry, media_common
Abstract

The CP-violation parameter \etazero\ is determined through the eigentime-dependent asymmetry in the rates of initially tagged \kzerob\ and \kzero\ decaying to \pizero \pizero. From the analysis of the complete data set we obtain the values $ \absetazero = [2.47 \pm 0.31_{\mbox{stat.}} \pm 0.24_{\mbox{syst.}}] \times 10^{-3} $ and $ \phizero = 42.0^0 \pm 5.6_{\mbox{stat.}}^0 \pm 1.9_{\mbox{syst.}}^0 % \pm 0.3_{\mbox{$\Delta$m}}^0 . $

Published
1998
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10. Measurement of CP,T and CPT violation parameters in the Neutral Kaon system at CPLEAR

Author

Andrej Filipcic, D. Francis, Marko Mikuz, A. Benelli, C.W.E. van Eijk, T. Schietinger, R. Le Gac, M. Fidecaro, C. Touramanis, Claude Guyot, E. Cawley, Ph. Schune, João Carvalho, F. Montanet, Frixos A Triantis, S. Vlachos, R. Ferreira-Marques, A. Ealet, P. Bloch, Ioannis Evangelou, Ch Yèche, B. Eckart, Elie Aslanides, F. Blanc, L. Sakeliou, J. R. Fry, C. Santoni, P. Kokkas, C. Kochowski, Marcin Wladyslaw Wolter, I. Papadopoulos, A. Haselden, E. van Beveren, A. Apostolakis, J. Derre, F. Touchard, T. Ruf, B. Pagels, O. Wigger, F. Leimgruber, Igor Mandić, D. Garreta, W. Fetscher, G. Polivka, R.W. Hollander, A. Go, R. Rickenbach, R. Gamet, A. Cody, T. Alhalel, M. Carroll, H.-J. Gerber, O. Behnke, A. Soares, J. Pinto da Cunha, P.R. Kettle, L. Tauscher, C. Felder, Mats Danielsson, R. Adler, E. Machado, P. Fassnacht, E. Hubert, A.J.P.L. Policarpo, A. Schopper, F. Henry-Couannier, D. Zimmerman, P. Carlson, P.J. Hayman, P. Sanders, Marc Dejardin, M.B. Chertok, Jeffrey Boone Miller, P. Weber, E. Gabathuler, V. Bertin, A. Angelopoulos, K. Jon-And, M. Schafer, P. Bargassa, Christopher Bee, Danilo Zavrtanik, R. Kreuger, G. Marel, Michael C. Carroll, L. Faravel, Lukas A. Schaller, T. Nakada, G. Chardin, P. Paylopoulos, G. Backenstoss, Stef. Charalambous, Nikolaos Manthos, A. Liolios, C. Thibault, B. L. Roberts, and C. Eleftheriadis

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Secondary education, Large Hadron Collider, Planck scale, CPT symmetry, Information storage, symbols.namesake, symbols, High Energy Physics::Experiment, Quantum, Research method, Coherence (physics)
Abstract

The CPLEAR experiment at CERN measures the time dependent decay rate asymmetries of initially pure K0 and K 0 states to study CP,T and CPT symmetries in the neutral kaon system. The latest results on η+−, Δm and x are reported, as well as direct tests of T violation and CPT violation in K0- K 0 oscillations. Our results are consistent with CPT invariance and allow for an improved limit on the K0- K 0 mass difference. Further, a possible loss of quantum coherence of the neutral kaon system has been tested to a level near the Planck scale.

Published
1997
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11. The CPLEAR-Experiment at CERN

Author

Christopher Bee, Marcin Wladyslaw Wolter, G. Chardin, J. Derre, Mats Danielsson, G. Backenstoss, Ch Yèche, R. Adler, A. Go, B. Eckart, T. Schietinger, A.J.P.L. Policarpo, A. Apostolakis, T. Alhalel, M.B. Chertok, Stef. Charalambous, A. Soares, P. Fassnacht, R. Le Gac, H.-J. Gerber, L. Faravel, D. Garreta, C. Felder, J. R. Fry, K. Jon-And, P. Bargassa, G. Polivka, Lukas A. Schaller, E. Hubert, W. Fetscher, P.R. Kettle, L. Tauscher, A. Haselden, E. Machado, Ph. Schune, D. Francis, Jeffrey Boone Miller, F. Henry-Couannier, A. Ealet, T. Ruf, O. Behnke, Claudio Santoni, Andrej Filipcic, R.W. Hollander, Marc Dejardin, Nikolaos Manthos, Danilo Zavrtanik, D. Zimmerman, Claude Guyot, F. Leimgruber, P. Pavlopoulos, A. Liolios, João Carvalho, F. Montanet, A. Schopper, M. Fidecaro, P. Weber, T. Nakada, P.J. Hayman, J. Pinto Dacunha, R. Ferreira-Marques, P. Sanders, M. Mikuz, I. Papadopoulos, R. Kreuger, Panagiotis Kokkas, O. Wigger, F. Blanc, C. Kochowski, R. Gamet, Ioannis Evangelou, G. Marel, B. Pagels, L. Sakeliou, M. Schafer, Per Carlson, Michael C. Carroll, C. Thibault, B. L. Roberts, C. Eleftheriadis, E. van Beveren, Sotirios Vlachos, F. Touchard, A. Angelopoulos, Igor Mandić, A. Cody, E. Gabathuler, R. Rickenbach, V. Bertin, Elie Aslanides, C. Touramanis, Frixos A Triantis, A. Benelli, C.W.E. van Eijk, E. Cawley, and P. Bloch

Subjects
Nuclear physics, Rest (physics), Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Large Hadron Collider, High Energy Physics::Phenomenology, Measure (physics), High Energy Physics::Experiment, Atomic and Molecular Physics, and Optics
Abstract

The CPLEAR experiment uses tagged K0 and K0 produced in pp annihilation at rest to measure CP-, T- and CPT-violation parameters in the neutral kaon system. The results of these measurements and some implications are reported.

Published
1997
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12. An upper limit for the branching ratio of the decay Ks → e+e−

Author

A. Angelopoulos, A. Apostolakis, E. Aslanides, G. Backenstoss, P. Bargassa, O. Behnke, A. Benelli, V. Bertin, F. Blanc, P. Bloch, P. Carlson, M. Carroll, J. Carvalho, E. Cawley, S. Charalambous, G. Chardin, M.B. Chertok, A. Cody, M. Danielsson, M. Dejardin, J. Derre, A. Ealet, C. Eleftheriadis, I. Evangelou, L. Faravel, R. Ferreira-Marques, W. Fetscher, M. Fidecaro, A. Filipčič, D. Francis, J. Fry, E. Gabathuler, R. Gamet, D. Garreta, H.-J. Gerber, A. Go, A. Haselden, P.J. Hayman, F. Henry-Couannier, R.W. Hollander, E. Hubert, K. Jon-And, P.-R. Kettle, P. Kokkas, R. Kreuger, R. Le Gac, F. Leimgruber, A. Liolios, E. Machado, I. Mandić, N. Manthos, G. Marel, M. Mikuž, J. Miller, F. Montanet, A. Muller, T. Nakada, B. Pagels, I. Papadopoulos, P. Pavlopoulos, J. Pinto da Cunha, A. Policarpo, G. Polivka, R. Rickenbach, B.L. Roberts, T. Ruf, L. Sakeliou, P. Sanders, M. Schäfer, L.A. Schaller, T. Schietinger, A. Schopper, A. Soares, L. Tauscher, C. Thibault, F. Touchard, C. Touramanis, F. Triantis, E. Van Beveren, C.W.E. Van Eijk, S. Vlachos, P. Weber, O. Wigger, M. Wolter, C. Yeche, D. Zavrtanik, and D. Zimmerman

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, High signal intensity, Branching fraction, CP violation, Limit (mathematics)
Abstract

A search for the decay KS → e+e− was performed within the framework of the CPLEAR experiment. Full event reconstruction together with e/π separation allowed powerful background rejection and high signal acceptance. The analysis of the complete set of data yields the result: BR(KS → e+e−) < 1.4 × 10−7 (90% CL), an improvement on the current experimental limit by a factor of 20.

Published
1997
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13. Upper limit for the branching ratio of KS → e+e− decay

Author

P. Bargassa, O. Behnke, Christopher Bee, Ch Yèche, B. Eckart, A. Haselden, P. Pavlopoulos, P. Sanders, F. Leimgruber, A. Schopper, Sotirios Vlachos, T. Alhalel, R. Adler, R.W. Hollander, P. Weber, A. Angelopoulos, P.J. Hayman, H.-J. Gerber, A. Go, W. Fetscher, P. Fassnacht, R. Le Gac, Panagiotis Kokkas, R. Ferreira-Marques, C. Eleftheriadis, Mats Danielsson, A. Soares, J. R. Fry, F. Henry-Couannier, C. Touramanis, J. Pinto da Cunha, E. Hubert, Ph. Schune, M. Miku, Michael C. Carroll, D. Garreta, I. Mandié, M.B. Chertok, Lukas A. Schaller, L. Faravel, T. Ruf, A. Ealet, Frixos A Triantis, K. Jon-And, Claudio Santoni, O. Wigger, Marcin Wladyslaw Wolter, J. Derre, Danilo Zavrtanik, P.R. Kettle, L. Tauscher, D. Zimmerman, D. Francis, A.J.P.L. Policarpo, A. Apostolakis, João Carvalho, F. Montanet, E. Machado, Claude Guyot, Jeffrey Boone Miller, A. Benelli, C.W.E. van Eijk, T. Nakada, Ioannis Evangelou, R. Gamet, F. Blanc, L. Sakeliou, C. Kochowski, V. Bertin, M. Schafer, Elie Aslanides, B. Pagels, R. Kreuger, Per Carlson, E. Gabathuler, R. Rickenbach, G. Marel, Marc Dejardin, P. Bloch, Nikolaos Manthos, A. Liolios, I. Papadopoulos, C. Felder, T. Schietinger, A. Filipĉič, G. Chardin, E. Cawley, M. Fidecaro, G. Backenstoss, A. Cody, C. Thibault, B. L. Roberts, E. van Beveren, F. Touchard, Stef. Charalambous, and G. Polivka

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle decay, Meson, Branching fraction, Quantum mechanics, Hadron, Elementary particle, Limit (mathematics), Atomic and Molecular Physics, and Optics, Calorimeter, Boson
Abstract

A measurement of the branching ratio for K s → e + e − decay was performed with the CPLEAR detector at LEAR. Full event reconstruction together with calorimeter e/π separation allowed for powerful background rejection and high signal acceptance. Analysis of data taken up to 1994 yields the result: Br(K s → e + e − ) −7 (90 % CL).

Published
1997
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14. Experimental measurement of the ratio in antiproton annihilations at rest in gaseous hydrogen at 15 and 27 bar

Author

Ioannis Evangelou, C. Thibault, L. Sakeliou, R. Gamet, A. Soares, C. Eleftheriadis, Per Carlson, A. Cody, R. Kreuger, E. van Beveren, F. Touchard, M. Schafer, Jeffrey Boone Miller, E. Cawley, P.-R. Kettle, A. Go, Lukas A. Schaller, T. Alhalel, G. Marel, Ch Yèche, M. Mikuž, A. Muller, B. Eckart, C. Touramanis, D. Francis, Stef. Charalambous, L. Tauscher, Frixos A Triantis, H.-J. Gerber, Mats Danielsson, Ph. Schune, I. Papadopoulos, E. Machado, A. Ealet, M. Fidecaro, R. Ferreira-Marques, F. Blanc, P. Fassnacht, G. Polivka, Rr. Adler, C. Kochowski, Claudio Santoni, P. Pavlopoulos, D. Garreta, Danilo Zavrtanik, E. Hubert, T. Ruf, M.B. Chertok, B. Pagels, L. Faravel, J. Pinto da Cunha, B.L. Roberts, D. Zimmerman, João Carvalho, K. Jon-And, F. Montanet, A. Benelli, C.W.E. van Eijk, Panagiotis Kokkas, Michael C. Carroll, P. Sanders, W. Fetscher, P. Weber, Marc Dejardin, G. Chardin, Marcin Wladyslaw Wolter, J. Derre, A. Haselden, T. Nakada, R. Le Gac, G. Backenstoss, A.J.P.L. Policarpo, C. Felder, V. Bertin, A. Apostolakis, R.W. Hollander, Elie Aslanides, J. R. Fry, Sotirios Vlachos, F. Henry-Couannier, A. Angelopoulos, Andrej Filipcic, Nikolaos Manthos, A. Liolios, Claude Guyot, P. Bargassa, Christopher Bee, Igor Mandić, O. Behnke, F. Leimgruber, A. Schopper, P.J. Hayman, O. Wigger, T. Schietinger, P. Bloch, E. Gabathuler, and R. Rickenbach

Subjects
Physics, Nuclear and High Energy Physics, Annihilation, Antiproton, Gaseous hydrogen, Atomic physics
Abstract

The ratio R between the branching fractions of p p → K S K S and p p → K S K L for antiprotons annihilating at rest in gaseous hydrogen at 27 bar pressure was measured with the CPLEAR detector to be R(27 bar) = 0.037 ± 0.002. The fraction of P-wave annihilation at rest at this target density was deduced to be 0.45 ± 0.06. A value of R was also measured at 15 bar, with less statistics, yielding R(15 bar) = 0.041 ± 0.009.

Published
1997
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15. Results of CPLEAR

Author

Ioannis Evangelou, Ch Yèche, B. Eckart, L. Sakeliou, O. Behnke, Nikolaos Manthos, W. Fetscher, F. Henry-Couannier, F. Blanc, P.R. Kettle, L. Tauscher, F. Leimgruber, R. Kreuger, P. Fassnacht, A. Liolios, E. Machado, R. Gamet, A. Schopper, E. Hubert, C. Kochowski, P. Sanders, P.J. Hayman, P. Weber, Elie Aslanides, Christopher Bee, B. Pagels, G. Marel, R. Ferreira-Marques, T. Schientinger, D. Zimmerman, M. Mikuz, T. Ruf, E. van Beveren, A. Apostolakis, Claudio Santoni, P. Carlson, A.J.P.L. Policarpo, R. Le Gac, F. Touchard, Mats Danielsson, R. Adler, C. Touramanis, V. Bertin, D. Garreta, Marc Dejardin, Michael C. Carroll, Frixos A Triantis, D. Francis, I. Papadopoulos, João Carvalho, M. Schafer, F. Montanet, J. R. Fry, M.B. Chertok, A. Cody, Sotirios Vlachos, A. Go, I. Mandlic, K. Jon-And, A. Angelopoulos, Lukas A. Schaller, P. Pavlopoulos, J. Pinto da Cunha, A. Soares, A. Haselden, Jeffrey Boone Miller, E. Cawley, P. Bargassa, Ph. Schune, R.W. Hollander, Danilo Zavrtanik, A. Ealet, A. Benelli, C.W.E. van Eijk, G. Chardin, M. Fidecaro, Andrej Filipcic, C. Felder, G. Backenstoss, Claude Guyot, Panagiotis Kokkas, T. Nakada, Stef. Charalambous, G. Polivka, C. Thibault, B. L. Roberts, C. Eleftheriadis, E. Gabathuler, R. Rickenbach, L. Faravel, P. Bloch, T. Alhalel, H.-J. Gerber, O. Wigger, Marcin Wladyslaw Wolter, and J. Derre

Subjects
Nuclear physics, Rest (physics), Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Measure (physics), Atomic and Molecular Physics, and Optics
Abstract

The CPLEAR experiment uses tagged K 0 and K 0 produced in pp annihilation at rest to measure CP-, T- and CPT-violation parameters in the neutral kaon system. The results of these measurements and some implications are reported.

Published
1997
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16. Measurement of η+− with the CPLEAR experiment

Author

C. Thibault, Andrej Filipcic, B. L. Roberts, C. Eleftheriadis, Claude Guyot, L. Faravel, M.B. Chertok, T. Ruf, Ch Yèche, B. Eckart, Claudio Santoni, K. Jon-And, J. Pinto da Cunha, Danilo Zavrtanik, P. Sanders, T. Schietinger, R. Le Gac, João Carvalho, F. Montanet, T. Alhalel, P. Bloch, M. Schafer, G. Chardin, A. Haselden, G. Backenstoss, Jeffrey Boone Miller, H.-J. Gerber, J. R. Fry, W. Fetscher, Stef. Charalambous, R.W. Hollander, G. Polivka, P.R. Kettle, L. Tauscher, O. Behnke, A. Go, Sotirios Vlachos, A. Benelli, C.W.E. van Eijk, M. Fidecaro, E. Machado, Marcin Wladyslaw Wolter, J. Derre, F. Blanc, F. Henry-Couannier, A. Soares, A. Angelopoulos, A. Apostolakis, Mats Danielsson, R. Adler, E. Gabathuler, P. Fassnacht, C. Kochowski, D. Francis, D. Garreta, Nikolaos Manthos, R. Rickenbach, F. Leimgruber, A. Schopper, A. Liolios, C. Touramanis, P.J. Hayman, T. Nakada, B. Pagels, Igor Mandić, R. Gamet, E. Hubert, C. Felder, Frixos A Triantis, P. Pavlopoulos, Christopher Bee, A.J.P.L. Policarpo, R. Ferreira-Marques, O. Wigger, M. Miku, P. Weber, D. Zimmerman, V. Bertin, Elie Aslanides, Ioannis Evangelou, Marc Dejardin, Panagiotis Kokkas, L. Sakeliou, Lukas A. Schaller, P. Bargassa, Per Carlson, R. Kreuger, I. Papadopoulos, G. Marel, Michael C. Carroll, Ph. Schune, A. Ealet, E. van Beveren, F. Touchard, A. Cody, and E. Cawley

Subjects
Systematic error, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Computer science, Statistics, Measure (mathematics), Atomic and Molecular Physics, and Optics
Abstract

The CPLEAR experiment at CERN uses time-dependent decay-rate asymmetries between K 0 and K 0 to measure η +− . The analysis and the systematic errors are discussed. The preliminary results from all our data are φ +− = 43.5 0 ± 0.5 0 stat ± 0.5 syst ± 0.4 Δm and | η +−| = (2.316 ± 0.025 stat ± 0.028 syst ± 0.009 τ S ) × 10 −3 . The dominant part in the systematic error of φ +− is due to the regeneration correction. A dedicated experiment was performed to reduce this error considerably.

Published
1997
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17. The CPLEAR detector at CERN

Author

K. Philippoussis, H. Verweij, G. Backenstoss, P. Bloch, G. Kesseler, A. Haselden, Andrej Filipcic, P. Pavlopoulos, F. Louis, D. Damianoglou, E. Rozaki, Panagiotis Kokkas, Dominique Durand, P.-R. Kettle, M. Bonnet, F. Bal, H.U. Johner, Claude Guyot, M. Steinacher, P. Petit, T. Alhalel, R.W. Hollander, Andras Kerek, Ch Yèche, D.A. Troster, L. Faravel, M. Mikuž, D. Francis, O. Behnke, B. Eckart, Sp. Dedoussis, J. Duclos, K. Sarigiannis, C. Engster, J.P. Bard, E. Gabathuler, M. Dedieu, R. Rickenbach, T. Ruf, Mats Danielsson, R. Adler, N. Dudragne, C. Jacobs, C.P. Marin, P. Weber, Ph. Schune, E. Machado, M. Schafer, V. Bertin, P.F. Harrison, H.-J. Gerber, F. Leimgruber, A. Schopper, K. Jansson, H. Martin, Christopher Bee, L. Sacks, Ioannis Evangelou, W.G. Heyes, P. Gumplinger, M. Dodgson, R. Le Gac, A. Ealet, T. Nakada, H. Postma, E. Hazen, L. Sakeliou, R. Daniel, Ch. Bula, E. Aslanides, Nikolaos Manthos, P Harrison, P.J. Hayman, W. Albrecht, F. Nanni, M. Chardalas, Per Carlson, H. Tschopp, M.B. Chertok, A. Liolios, D. Lecouturier, Ch. Rhême, D. Garreta, J.C. Michau, W. Fetscher, C. Witzig, J. R. Fry, M. Fidecaro, P. Fassnacht, A. Benelli, C.W.E. van Eijk, Christer Fuglesang, G. S. Varner, A. Go, E. Hubert, M. Dröge, K. Jon-And, S. Tatsis, Claudio Santoni, Marc Dejardin, B.L. Roberts, Lukas A. Schaller, A. Calzas, F. Blanc, U. Mall, D. King, R. Gamet, C. Touramanis, T. Geralis, D. Guyon, C. Kochowski, N. Karkour, D. Zimmerman, T. Klados, Frixos A Triantis, Danilo Zavrtanik, F. Henry-Couannier, C. Felder, D. Barraca, B. Pagels, A. Soares, D. Linget, João Carvalho, F. Montanet, L. Tauscher, P. Dechelette, P. Tsilimigras, B. Lofstedt, K. Kontek, Marcin Wladyslaw Wolter, P. Sanders, I. Papadopoulos, J. Derre, F. Pelucchi, P. Maley, O. Wigger, B. van Koningsveld, Jeffrey Boone Miller, A.J.P.L. Policarpo, D. Geiss, T. Lawry, H. Wendler, G. Chardin, Jean-Louis Faure, J. Kern, C. Thibault, C. Eleftheriadis, Stef. Charalambous, D. Warner, G. Polivka, Michael C. Carroll, R. Kreuger, A. Apostolakis, G. Marel, I. Tsamouranis, P. Charra, Sotirios Vlachos, A. Angelopoulos, J. Pinto da Cunha, A. Onofre, T. Schietinger, J. Bennet, Igor Mandić, A. Dijksman, J.P. Vanuxem, Y. Gally, R. Ferreira-Marques, E. van Beveren, F. Touchard, J. A. P. Da Silva, A. Cody, B. Dinkespiller, E. Cawley, E. Watson, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), CPLEAR, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Lorgeril, Jocelyne

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Large Hadron Collider, [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Cherenkov detector, Detector, Tracking (particle physics), 7. Clean energy, 01 natural sciences, Particle identification, law.invention, Nuclear physics, Time of flight, law, Antiproton, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, Detectors and Experimental Techniques, 010306 general physics, Instrumentation
Abstract

The CPLEAR collaboration has constructed a detector at CERN for an extensive programme of CP-, T- and CPT-symmetry studies using ${\rm K}^0$ and $\bar{\rm K}^0$ produced by the annihilation of $\bar{\rm p}$'s in a hydrogen gas target. The ${\rm K}^0$ and $\bar{\rm K}^0$ are identified by their companion products of the annihilation ${\rm K}^{\pm} \pi^{\mp}$ which are tracked with multiwire proportional chambers, drift chambers and streamer tubes. Particle identification is carried out with a liquid Cherenkov detector for fast separation of pions and kaons and with scintillators which allow the measurement of time of flight and energy loss. Photons are measured with a lead/gas sampling electromagnetic calorimeter. The required antiproton annihilation modes are selected by fast online processors using the tracking chamber and particle identification information. All the detectors are mounted in a 0.44 T uniform field of an axial solenoid of diameter 2 m and length 3.6 m to form a magnetic spectrometer capable of full on-line reconstruction and selection of events. The design, operating parameters and performance of the sub-detectors are described.}

Published
1996
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18. Measurement ofCP violation parameters and test ofCPT invariance with$$\overline {K^0 } $$ and K0 at LEARand K0 at LEAR

Author

Lukas A. Schaller, Danilo Zavrtanik, R. Le Gac, L. Tauscher, E. Machado, Nikolaos Manthos, A. Liolios, L. Faravel, P. R. Kettle, F. Blanc, Marc Dejardin, P. Sanders, A. Go, Sp. Dedoussis, A.J.P.L. Policarpo, C. Kochowski, J. R. Fry, W. Fetscher, A. Cody, Ph. Schune, G. S. Varner, A. Ealet, M. Schafer, J. Duclos, B. Pagels, E. Rozaki, R. Kreuger, A. Haselden, C. Thibault, I. Papadopoulos, G. Marel, T. Nakada, P. Pavlopoulos, B. L. Roberts, V. Bertin, C. Felder, Claudio Santoni, Andrej Filipcic, Elie Aslanides, C. Eleftheriadis, R.W. Hollander, Michael C. Carroll, João Carvalho, F. Montanet, Mats Danielsson, R. Adler, P. Weber, F. Henry-Couannier, Claude Guyot, A. Apostolakis, O. Wigger, O. Behnke, D. Garreta, F. Leimgruber, Ch Yèche, E. van Beveren, B. Eckart, F. Touchard, Frixos A Triantis, P.J. Hayman, E. Cawley, R. Gamet, Stef. Charalambous, T. Ruf, Marko Mikuz, Marcin Wladyslaw Wolter, J. Derre, G. Polivka, A. Benelli, C.W.E. van Eijk, R. Ferreira-Marques, Ioannis Evangelou, Ch. Bula, L. Sakeliou, J. Pinto da Cunha, M. Fidecaro, Per Carlson, G. Chardin, Jean-Louis Faure, G. Backenstoss, K. Sarigiannis, P. Fassnacht, Panagiotis Kokkas, A. Onofre, Igor Mandić, Christopher Bee, D. Francis, E. Hubert, T. Alhalel, A. Schopper, E. Gabathuler, R. Rickenbach, H.-J. Gerber, Sotirios Vlachos, D. Zimmerman, A. Angelopoulos, M. Chardalas, M.B. Chertok, K. Jon-And, A. Soares, C. Touramanis, Jeffrey Boone Miller, and P. Bloch

Subjects
Physics, Nuclear physics, Particle physics, Large Hadron Collider, Overline, Homogeneous space, Parity (physics), General Agricultural and Biological Sciences
Abstract

The CPLEAR experiment at CERN studies theCP, T andCPT symmetries in the neutral-kaon system by measuring the rate asymmetries between the decays of initially pure K0 and $$\overline {K^0 } $$ states. Using data taken between 1990 and mid 1994, precise measurements of |η+-|,φ +- and Δm are reported. The comparison of φ+- the superweak phase gives one of the most sensitive tests ofCPT invariance and leads to a new limit on the $$K^0 - \overline {K^0 } $$ mass difference.

Published
1996
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19. Observation of the CP-conserving Ks → π+π−π0 decay amplitude

Author

L. Faravel, P. Carlson, W. Fetscher, H. Postma, F. Henry-Couannier, O. Behnke, D. Garreta, M. Mikuž, L. Sacks, F. Leimgruber, Ioannis Evangelou, A. Schopper, D. Francis, C. Witzig, J. Duclos, R. Ferreira-Marques, Mats Danielsson, R. Adler, P.J. Hayman, P.F. Harrison, Andrej Filipcic, J. Derre, P.-R. Kettle, H.U. Johner, E. Gabathuler, R. Rickenbach, P. Gumplinger, Ch Yèche, Stef. Charalambous, B. Eckart, O. Wigger, L. Tauscher, L. Sakeliou, C. Touramanis, R. Le Gac, Claude Guyot, F. Blanc, T. Ruf, E. Machado, J. K. Bienlein, Frixos A Triantis, R. Gamet, Philippe Bloch, P. Pavlopoulos, Ph. Schune, G. Polivka, C. Kochowski, E. Aslanides, L.A. Schaller, Panagiotis Kokkas, K. Jansson, A. Ealet, T. Geralis, B.L. Roberts, M. Chardalas, M.B. Chertok, B. Pagels, Sotirios Vlachos, Danilo Zavrtanik, K. Jon-And, A. Angelopoulos, Claudio Santoni, G. Backenstoss, P. Fassnacht, R. Kreuger, A. Haselden, J. R. Fry, J. Pinto da Cunha, E. Rozaki, E. Hubert, A. Benelli, C.W.E. van Eijk, D.A. Troster, Sp. Dedoussis, Marcin Wladyslaw Wolter, F. Pelucchi, João Carvalho, F. Montanet, D. Zimmerman, Jeffrey Boone Miller, G. S. Varner, R.W. Hollander, C. Fuglesang, A. Onofre, M. Schafer, T. Lawry, Nikolaos Manthos, C. Felder, T. Alhalel, V. Bertin, T. Schietinger, Ch. Bula, M. Dodgson, A. Go, H.-J. Gerber, W.G. Heyes, A. Soares, A. Liolios, G. Chardin, Jean-Louis Faure, M. Fidecaro, A. Apostolakis, J. Bennet, I. Papadopoulos, C. Thibault, P. Maley, G. Marel, T. Nakada, P. Sanders, C. Eleftheriadis, Igor Mandić, A.J.P.L. Policarpo, P. Weber, Marc Dejardin, Michael C. Carroll, Christopher Bee, A. Cody, K. Sarigiannis, E. Cawley, E. van Beveren, and F. Touchard

Subjects
Physics, Nuclear and High Energy Physics, Amplitude, Branching fraction, Quantum mechanics, Phase space, Zero (complex analysis), Atomic physics, Interference (wave propagation)
Abstract

The interference between CP-conserving Ks and K L → π + π − π 0 decay amplitudes was observed by studying the decay rate asymmetries between initial K 0 and K 0 separately for the phase space regions E CM ( π + ) > E CM ( π − ) and E CM ( π + ) E CM ( π − ). For the parameter λ we found Re(λ) = 0.036 ± 0.010(stat.) −0.003 +0.002 (syst.) and Im(λ) consistent with zero, leading to a branching ratio B = [4.1 −1.9 +2.5 (stat.) −0.6 +0.5 (syst.)] × 10 −7 for the CP-conserving K S → π + π − π 0 decay.

Published
1996
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20. Evaluation of the phase of the CP violation parameter η+− and the KL - KS mass difference from a correlation analysis of different experiments

Author

Ch Yèche, B. Eckart, M. Mikuž, D. Francis, Igor Mandić, J. Derre, P. Fassnacht, C. Touramanis, E. van Beveren, F. Touchard, Frixos A Triantis, R. Gamet, L.A. Schaller, A. Haselden, O. Wigger, R. Ferreira-Marques, Christopher Bee, J. Pinto da Cunha, P. Carlson, W. Fetscher, E. Hubert, A. Cody, T. Schietinger, R.W. Hollander, L. Tauscher, C. Felder, F. Henry-Couannier, V. Bertin, Andrej Filipcic, D. Garreta, E. Machado, D. Zimmerman, Claudio Santoni, Ph. Schune, Jeffrey Boone Miller, Mats Danielsson, R. Adler, T. Nakada, Claude Guyot, A. Ealet, Michael C. Carroll, T. Ruf, L. Faravel, João Carvalho, A. Benelli, C.W.E. van Eijk, M.B. Chertok, E. Cawley, F. Montanet, K. Jon-And, P. Pavlopoulos, Marcin Wladyslaw Wolter, Danilo Zavrtanik, G. Backenstoss, G. Chardin, F. Blanc, O. Behnke, E. Gabathuler, R. Rickenbach, P.-R. Kettle, C. Kochowski, Panagiotis Kokkas, Ioannis Evangelou, F. Leimgruber, A. Schopper, B. Pagels, A. Go, R. Kreuger, L. Sakeliou, Marc Dejardin, P.J. Hayman, Nikolaos Manthos, A. Soares, A. Apostolakis, G. Marel, Sotirios Vlachos, A. Liolios, C. Thibault, B.L. Roberts, P. Sanders, A. Angelopoulos, M. Fidecaro, C. Eleftheriadis, A.J.P.L. Policarpo, H.-J. Gerber, I. Papadopoulos, Stef. Charalambous, G. Polivka, M. Schafer, P. Weber, R. Le Gac, E. Aslanides, J. R. Fry, G. S. Varner, and Philippe Bloch

Subjects
Physics, Nuclear and High Energy Physics, Quantum mechanics, Phase (matter), Correlation analysis, Analytical chemistry, CP violation
Abstract

The best estimation of ϕ +− (the phase of the CP violation parameter η +− ) and of Δm (the K L - K S mass difference) is obtained by averaging the results of different experiments, taking into account the different correlation, existing for most of the experiments, between the measurement of ϕ +− and Δm . Including the recent measurements, we obtain the average values 〈Δm〉 = (530.7 ± 1.3) × 10 7 ħ/s and 〈 ϕ +− 〉 = 43.82° ± 0.63°. This value of ϕ +− is in good agreement with the superweak phase ϕ SW = 43.49° ± 0.08°.

Published
1996
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21. Measurement of the CP violation parameter η+− using tagged K0 and 0

Author

M. Chardalas, M.B. Chertok, K. Jon-And, T. Alhalel, R. Le Gac, M. Schafer, A. Haselden, C. Thibault, J. Bennet, Andrej Filipcic, R.W. Hollander, Claudio Santoni, C. Felder, P. Carlson, Mats Danielsson, R. Adler, W. Fetscher, T. Nakada, Igor Mandić, R. Ferreira-Marques, E. Cawley, C. Eleftheriadis, E. Aslanides, J. R. Fry, João Carvalho, F. Montanet, H.U. Johner, Claude Guyot, P.F. Harrison, H.-J. Gerber, F. Henry-Couannier, W.G. Heyes, G. S. Varner, P.-R. Kettle, V. Bertin, L. Tauscher, Ch Yèche, B. Eckart, O. Wigger, L. Faravel, P. Sanders, E. Machado, J. Derre, Panagiotis Kokkas, D. Garreta, G. Policarpo, D. Gamet, Stef. Charalambous, C. Touramanis, J. K. Bienlein, Nikolaos Manthos, B.L. Roberts, Ch. Bula, Frixos A Triantis, O. Behnke, A. Liolios, A. Cody, L. Sacks, Philippe Bloch, M. Dodgson, Marc Dejardin, F. Leimgruber, Sp. Dedoussis, G. Polivka, Sotirios Vlachos, A. Schopper, M. Fidecaro, T. Schietinger, H. Postma, T. Geralis, A. Benelli, C.W.E. van Eijk, P.J. Hayman, Danilo Zavrtanik, A. Go, A. Angelopoulos, Ph. Schune, G. Backenstoss, Marcin Wladyslaw Wolter, J. Pinto da Cunha, I. Papadopoulos, P. Weber, A. Ealet, F. Pelucchi, T. Lawry, J. Duclos, E. van Beveren, F. Touchard, P. Maley, A. Soares, M. Mikuž, D. Francis, P. Pavlopoulos, A. Onofre, T. Ruf, R. Gamet, K. Jansson, G. Chardin, Jean-Louis Faure, L.A. Schaller, E. Rozaki, C. Witzig, K. Sarigiannis, F. Blanc, C. Kochowski, Christopher Bee, B. Pagels, Jeffrey Boone Miller, C. Fuglesang, Ioannis Evangelou, R. Kreuger, E. Gabathuler, R. Rickenbach, P. Gumplinger, A. Apostolakis, G. Marel, L. Sakeliou, Michael C. Carroll, P. Fassnacht, E. Hubert, D. Zimmerman, and D.A. Troster

Subjects
Nuclear physics, Physics, Semileptonic decay, Nuclear and High Energy Physics, media_common.quotation_subject, CP violation, Asymmetry, media_common
Abstract

The CP violation parameter η+− is determined through the eigentime-dependent asymmetry in the rates of initially tagged K0 and K 0 decaying to π+π−. The obtained values are |η+−| = (2.312 ± 0.043stat. ± 0.030syst. ± 0.011τs) × 10−3 and Φ+− = 42.7° ± 0.9stat.° ± 0.6syst.° ± 0.9Δm° with Δ = (527.4 ± 2.9) × 10 7 h gs −1 measured in the same experiment using the semileptonic decay channel.

Published
1995
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22. Inclusive measurement of $$\bar p$$ annihilation at rest in gaseous hydrogen to final states containingρ andf 2

Author

R. Le Gac, E. Aslanides, J. R. Fry, P. Bloch, G. S. Varner, P. Sanders, J.C. Dousse, T. Alhalel, Christopher Bee, Mats Danielsson, R. Adler, A. Haselden, Ioannis Evangelou, O. Wigger, R.W. Hollander, M. Chardalas, M.B. Chertok, K. Jon-And, P. Gumplinger, L. Sakeliou, A.J.P.L. Policarpo, L. Faravel, H.-J. Gerber, Jeffrey Boone Miller, Stef. Charalambous, Per Carlson, T. Nakada, W. Fetscher, J. K. Bienlein, K. Sarigiannis, E. Gabathuler, L. Sacks, R. Richkenbach, D.A. Troster, W.G. Heyes, C.W.E. van Eijk, G. Polivka, A. Go, H. Postma, Christer Fuglesang, R. Gamet, Nikolaos Manthos, P. Fassnacht, Sp. Dedoussis, Ch. Bula, M. Schafer, A. Liolios, Lukas A. Schaller, P. Pavlopoulos, F. Henry-Couannier, A. Soares, C. Touramanis, Marcin Wladyslaw Wolter, C. Witzig, P. Weber, J. Bennet, J. Derre, M. Fidecaro, P. F. Harrisch, F. Pelucchi, Frixos A Triantis, B. Eckart, A. Angelopoulos, J. Pinto da Cunha, D. Zimmerman, C. Thibault, O. Behnke, C. Kochowski, T. Lawry, M. Mikuž, D. Francis, T. Geralis, B. L. Roberts, Danilo Zavrtanik, B. Pagels, C. Eleftheriadis, A. Schopper, R. Ferreira-Marques, P. Maley, Andras Kerek, P.J. Hayman, Igor Mandić, Francois Touchard, A. Onofre, Panagiotis Kokkas, C. Felder, C. Yeche, V. Bertin, P.R. Kettle, L. Tauscher, G. Chardin, Jean-Louis Faure, E. Machado, D. Garreta, J. Kern, G. Backenstoss, R. Kreuger, A. Apostolakis, Andrej Filipcic, H.U. Johner, Claude Guyot, A. Cody, S. Vlachos, G. Marel, E. Cawley, J. Duclos, T. Ruf, K. Jansson, E. van Beveren, Marc Dejardin, E. Rozaki, M. Dodgson, Claudio Santoni, João Carvalho, F. Montanet, Ph. Schune, and A. Ealet

Subjects
Physics, Annihilation, Physics and Astronomy (miscellaneous), Hydrogen, Meson, Gaseous hydrogen, chemistry.chemical_element, Elementary particle, Nuclear physics, chemistry, Antiproton, Quantum field theory, Atomic physics, Engineering (miscellaneous)
Abstract

Antiproton annihilation at rest in gaseous hydrogen (16 bar pressure) to the final states ρ(770)X andf2(1270)X, whereX stands for one or more neutral mesons, has been studied at LEAR using the CPLEAR detector. Relative branching ratios are given forX =π0,2π0, 3π0 ω in the ρ case, and forX =π0, η in thef2 case. The annihilation channel\(\bar pp \to \rho 3\pi ^0 \) has not been measured before. The fraction of P-wave annihilation is deduced from the ratiof2π0/ρπ0 to be 0.38±0.07, in good agreement with the result previously obtained by CPLEAR from the ratioK+K-/π+π-.

Published
1995
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24. Bose-Einstein correlations in $$\bar p$$ p annihilations at rest

Author

P. Fassnacht, P. Sanders, A.J.P.L. Policarpo, Claudio Santoni, O. Behnke, K. Jon-And, A. Schopper, A. Haselden, P.J. Hayman, Jeffrey Boone Miller, M. Mikuž, D. Francis, L. Faravel, K. Sarigiannis, João Carvalho, F. Montanet, D. Zimmerman, C. Touramanis, E. van Beveren, R.W. Hollander, E. Rozaki, Christopher Bee, P. Weber, R. Gamet, B. Eckart, Frixos A Triantis, L. Tauscher, R. Le Gac, F. Touchard, Andras Kerek, E. Machado, L.A. Schaller, E. Aslanides, T. Nakada, L. Sacks, H. Postma, C. Fuglesang, T. Geralis, A. Apostolakis, J. Bennet, R. Kreuger, J. Duclos, T. Ruf, Igor Mandić, M. Dodgson, J. R. Fry, G. S. Varner, Danilo Zavrtanik, K. Jansson, A. Cody, Philippe Bloch, Ioannis Evangelou, P. Carlson, W. Fetscher, P. Gumplinger, L. Sakeliou, P. Maley, Sp. Dedoussis, S. Vlachos, C. Felder, D.A. Troster, C. Witzig, C. Yeche, M. Chardalas, G. Marel, F. Henry-Couannier, M.B. Chertok, M. Schafer, E. Cawley, C.W.E. van Eijk, P. Pavlopoulos, Marc Dejardin, V. Bertin, R. Ferreira-Marques, Mats Danielsson, R. Adler, P.F. Harrison, Ph. Schune, A. Ealet, C. Kochowski, B. Pagels, A. Go, Andrej Filipcic, H.U. Johner, Claude Guyot, A. Soares, C. Thibault, C. Eleftheriadis, G. Chardin, Jean-Louis Faure, D. Garreta, J. Kern, G. Backenstoss, Ch. Bula, M. Fidecaro, Panagiotis Kokkas, Stef. Charalambous, G. Polivka, P.-R. Kettle, Nikolaos Manthos, A. Liolios, Marcin Wladyslaw Wolter, J. Derre, F. Pelucchi, A. Angelopoulos, T. Lawry, E. Gabathuler, R. Rickenbach, J.C. Dousse, T. Alhalel, J. Pinto da Cunha, H.-J. Gerber, A. Onofre, W.G. Heyes, O. Wigger, J. K. Bienlein, and B.L. Roberts

Subjects
Physics, Nuclear physics, Correlation function (statistical mechanics), Particle physics, Pion, Physics and Astronomy (miscellaneous), Antiproton, Symmetrization, Elementary particle, Bose–Einstein correlations, Wave function, Engineering (miscellaneous), Exponential function
Abstract

Two-charged-pion correlations were studied in\(\bar p\)p(→2π*2π−nπ0,n≥0) annihilations at rest with the CPLEAR detector at the Low-Energy Antiproton Ring (LEAR). A strong enhancement was found in the production of pairs of like-sign pions with a small value of the relative fourmomentumQ, with respect to pairs of unlike-sign pions. The observed enhancement was interpreted as a consequence of the Bose-Einstein symmetrization of the two-pion wave function. The data are well represented by a correlation function parametrized as a double-Gaussian; an exponential parametrization is also statistically acceptable. The value of the correlation strength is found to be >1. The high-quality large data samples together with the ability for K± identification and final-state separation allowed the study of systematic effects impacting on theQ dependence of the correlation function and on the extracted space parameters of the pion sources.

Published
1994
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25. Two pion Bose-Einstein correlations in p annihilations at rest

Author

G. Chardin, Jean-Louis Faure, D. Garreta, J. Kern, G. Backenstoss, C. Thibault, C. Eleftheriadis, Ch Yèche, Francois Touchard, B. Eckart, Stef. Charalambous, Christer Fuglesang, G. Polivka, J. Pinto da Cunha, H. Postma, K. Sarigiannis, Sp. Dedoussis, R. Le Gac, J. R. Fry, P. Gumplinger, Andras Kerek, J. Duclos, M. Dejardin, A. Go, Ph. Schune, M. Schafer, T. Ruf, M. Chardalas, A. Onofre, A. Soares, R. Kreuger, A. Ealet, Kerstin Jon-And, Christopher Bee, K. Jansson, Nikolaos Manthos, P. Pavlopoulos, Ioannis Evangelou, G. S. Varner, A. Liolios, A. Schopper, B.L. Roberts, P.J. Hayman, J.P. Miller, E. van Beveren, T. Nakada, R. Garnet, Ch. Bula, P.R. Kettle, L. Tauscher, C. Witzig, V. Bertin, W. Fetscher, E. Machado, O. Wigger, Elie Aslanides, J. K. Bienlein, M. Fidecaro, M. Van den Putte, A. Alhalel, J.C. Dousse, P. Fassnacht, S. Vlachos, O. Wolter, G. Marel, J. Bennet, E. Cawley, Marko Mikuz, A. Apostolakis, Mats Danielsson, D.A. Troester, H.-J. Gerber, R. Adler, Igor Mandić, Danilo Zavrtanik, E. Gabathuler, R. Rickenbach, D. Zimmerman, E. Rozaki, W.G. Heyes, C. Kochowski, P. Carlson, R. Ferreira-Marques, B. Pagels, David Francis, C.W.E. van Eijk, P. Sanders, S. Szilagyi, Theodoros Geralis, A. Angelopoulos, P.F. Harrison, A.J.P.L. Policarpo, P. Bloch, J. Derre, Panagiotis Kokkas, F. Pelucchi, P. Weber, C. Touramanis, R.W. Hollander, Frixos A Triantis, T. Lawry, L.A. Schaller, Claudio Santoni, Andrej Filipcic, H.U. Johner, João Carvalho, F. Montanet, Claude Guyot, C. Felder, M. Dodgson, P. Maley, L. Sakeliou, L. Faravel, and L. Sacks

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Pion, Large Hadron Collider, Nuclear Theory, Detector, High Energy Physics::Experiment, Bose–Einstein correlations, Multiplicity (chemistry), Nuclear Experiment
Abstract

Bose-Einstein (BE) correlations between like-sign charged pions were studied in pp annihilations at rest into four-prong events, using data taken with the CPLEAR detector at LEAR (CERN). A strong enhancement was found in the production of pairs of like-sign pions of similar momenta, with respect to the pairs of unlike-sign pions. The observed BE- enhancement was used to extract the values for the strength λ of the effect and the radius r of the pion emitting source. The extracted value of λ >l is of relevant importance and clearly does not depend on the assumed parametrization of the correlation function. The influence of the normalization and fitting procedure, the detector resolution, the resonances production and decay and the neutral-pion multiplicity cuts, on the size of the pion source and the strength of the effect was investigated.

Published
1993
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26. First determination of CP violation parameters from K0−0 decay asymmetry

Author

S. Charalambous, D. Francis, T. Alhalel, P. Fassnacht, M. Dodgson, J. Bennet, R. Rickenbach, Claudio Santoni, K. Sarigiannis, João Carvalho, M. Van den Putte, F. Montanet, B. Eckart, C. Thibault, E. Gabathuler, E. Aslanides, A. Filipcic, T. Nakada, Marko Mikuz, Kerstin Jon-And, P Harrison, A. Schopper, F. Touchard, C. Touramanis, R. Ferreira-Marques, H. Cobbaert, H.-J. Gerber, P.-R. Kettle, E. van Beveren, P. Kokkas, J. R. Fry, S. Szilagyi, P.J. Hayman, Ch. Bula, G. Polivka, Ph. Schune, J. Duclos, W.G. Heyes, E. Rozaki, T. Geralis, W. Fetscher, A. Apostolakis, A. Ealet, A. Go, M. Fidecaro, P. Maley, L. Faravel, J.K. Bielein, T. Lawry, G. Varner, T. Ruf, P. Carlson, A. Onofre, J. Pinto Dacunha, P. Pavlopoulos, Christopher Bee, D. Zimmerman, K. Jansson, P. Sanders, S. Vlachos, Christer Fuglesang, C.W.E. Van Eijk, R. Adler, M. Chardalas, Andras Kerek, Marc Dejardin, G. Marel, L. Sacks, L.A. Schaller, F. Triantis, R. Le Gac, Claude Guyot, G. Burgun, A.J.P.L. Policarpo, E. Machado, J. Derre, P. Weber, F. Pelucchi, A. Angelopoulos, R. Kreuger, S. Dedoussis, D.A. Troster, P. Gumplinger, L. Sakeliou, C. Felder, J. Miller, N. Manthos, G. Chardin, Jean-Louis Faure, C. Yeche, D. Garreta, G. Backenstoss, M. Schafer, C. Witzig, R. Gamet, C. Kochowski, H.U. Johner, B. Pagels, L. Tauscher, J.-C. Dousse, H. Postma, D. Zavrtanik, J. Kern, P. Bloch, E. Cawley, R.W. Hollander, and U. Seljak

Subjects
Physics, Systematic error, Nuclear and High Energy Physics, Particle physics, media_common.quotation_subject, Value (computer science), Asymmetry, Nuclear physics, Pion, CP violation, High Energy Physics::Experiment, Direct proof, Nuclear Experiment, Bar (unit), media_common
Abstract

We report the first determination of CP violation parameters from parameter from particle—antiparticle asymmetry in the decay of neutral kaons into two charged pions. Observation of such an asymmetry is direct proof of CP violation. A fit to the asymmetry enabled a determination of the parameter η+− to be made, yielding the result |η+−|=[2.32±0.14 (stat.)±0.03 (syst.)]×10−3 and σ+−=42.3°±4.4° (stat.)±0.4° (syst.), with an additional uncertainty of ±1.0° due to the error on the present published value of Δm, the KL0-KS0 mass difference. The magnitudes of both statistical and systematic errors will be significantly reduced in the future.

Published
1992
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27. Radiative transitions in a unitarized meson model

Author

C. Dullemond, A. G. M. Verschuren, and E. van Beveren

Subjects
Physics, Particle physics, Meson, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Hadron, Radiative transfer, High Energy Physics::Experiment, Elementary particle, Perturbation theory (quantum mechanics), Quarkonium, Quantum number, Boson
Abstract

Radiative transitions in charmonium and bottomonium are calculated in a unitarized meson model, and an analysis of the results and the validity of common approximations is given. The results for charmonium indicate the need for relativistic corrections in our model; those for bottomonium agree very well with experiment (as far as they are available).

Published
1991
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28. Determination of the relative branching ratios for

Author

Philippe Bloch, Andrej Filipcic, Ch. Bula, Stef. Charalambous, D. Warner, J. Derre, A. Go, C. Felder, H.U. Johner, Claude Guyot, L. Sakeliou, T. Geralis, D.A. Troester, G. Backenstoss, H. Postma, E. van Beveren, T. Lawry, C.W.E. van Eijk, J.C. Dousse, David Francis, L. Tauscher, P. Fassnacht, L. Faravel, M. Fidecaro, E. Aslanides, J. Duclos, H.-J. Gerber, R. Kreuger, João Carvalho, G. Marel, C. Touramanis, Christer Fuglesang, W.G. Heyes, E. Kossionides, A. Apostolakis, L. Sacks, T. Paradelis, Frixos A Triantis, R. Le Gac, G. S. Varner, E. Machado, P. Weber, K. Jansson, K. Sarigiannis, L.A. Schaller, A. Onofre, J. R. Fry, J. Bennet, B.L. Roberts, T. Nakada, P. Marotte, Sp. Dedoussis, F. Montanet, A. Schopper, Christopher Bee, P.J. Hayman, P. Pavlopoulos, R. Gamet, Jean-Louis Faure, R. Ferreira-Marques, M. Dodgson, Panagiotis Kokkas, S. Szilagyi, P.F. Harrison, S. Vlachos, D. Garreta, J. Kern, T. Ruf, C. Burgun, M. Van den Putte, W. Fetscher, C. Thibault, E. Gabathuler, R. Rickenbach, Francois Touchard, M. Mikuž, P. Maley, A. Ealet, Danilo Zavrtanik, R.W. Hollander, Ch Yèche, B. Eckart, R. Adler, P. Sanders, M. Chardalas, C. Santoni, A.J.P.L. Policarpo, F. Pelucchi, C. Witzig, C. Kochowski, B. Pagels, Jeffrey Boone Miller, D. Zimmerman, J. Pinto da Cunha, P. Gumplinger, Per Carlson, Marc Dejardin, Andras Kerek, E. Rozaki, P.-R. Kettle, H. Cobbaert, A. Angelopoulos, Kerstin Jon-And, Nikolaos Manthos, Ph. Schune, and U. Seljak

Subjects
Physics, Nuclear and High Energy Physics, Pair production, Annihilation, Pion, Meson, Branching fraction, Antiproton, Protonium, Hadron, Analytical chemistry, Atomic physics
Abstract

The ratio of the branching fractions for p p →K+K− and p p →π+π− was determined with the CPLEAR detector, by stopping antiprotons in a gaseous hydrogen target at 15 bar pressure. It was found to be BR(K+K−)/BR(π+π−)=0.205± 0.016. The fraction of P-wave annihilation at rest at this target density was deduced to be (38±9)%.

Published
1991
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29. Scalar mesons as systems with meson-meson admixtures

Author

E. van Beveren

Subjects
Quark, Physics, Nuclear and High Energy Physics, Particle physics, Meson, High Energy Physics::Lattice, Nuclear Theory, High Energy Physics::Phenomenology, Hadron, Eta meson, Quark model, Elementary particle, Atomic and Molecular Physics, and Optics, Nuclear physics, Pion, Hadron spectroscopy, High Energy Physics::Experiment, Nuclear Experiment
Abstract

The resonances in meson meson scattering and the bound states of quarks andantiquarks are described within the same formalism. Comparison with experiment shows that this strategy is very promising for a detailed study of strong interactions and confinement.

Published
1991
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30. A low-lying scalar meson nonet in a unitarized meson model

Author

C. Dullemond, Th. A. Rijken, E. van Beveren, K. Metzger, George Rupp, and J. E. F. T. Ribeiro

Subjects
Physics, Particle physics, Physics and Astronomy (miscellaneous), Meson, Scattering, High Energy Physics::Lattice, Scalar (mathematics), High Energy Physics::Phenomenology, Nuclear Theory, Phase (waves), FOS: Physical sciences, Model parameters, Pseudoscalar, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Bound state, High Energy Physics::Experiment, Scalar meson, Nuclear Experiment, Engineering (miscellaneous)
Abstract

A unitarized nonrelativistic meson model which is successful for the description of the heavy and light vector and pseudoscalar mesons yields, in its extension to the scalar mesons but for the same model parameters, a complete nonet below 1 GeV. In the unitarization scheme, real and virtual meson-meson decay channels are coupled to the quark-antiquark confinement channels. The flavor-dependent harmonic-oscillator confining potential itself has bound states epsilon(1.3 GeV), S(1.5 GeV), delta(1.3 GeV), kappa(1.4 GeV), similar to the results of other bound-state qqbar models. However, the full coupled-channel equations show poles at epsilon(0.5 GeV), S(0.99 GeV), delta(0.97 GeV), kappa(0.73 GeV). Not only can these pole positions be calculated in our model, but also cross sections and phase shifts in the meson-scattering channels, which are in reasonable agreement with the available data for pion-pion, eta-pion and Kaon-pion in S-wave scattering., Comment: A slightly revised version of Zeitschrift fuer Physik C30, 615 (1986)

Published
2007
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33. $X(3872)$ Electromagnetic Decay in a Coupled-channel Model

Author

Marco Cardoso, E. van Beveren, and George Rupp

Subjects
Physics, High Energy Physics::Lattice, High Energy Physics::Phenomenology, FOS: Physical sciences, General Physics and Astronomy, Channel models, High Energy Physics - Experiment, Schrödinger equation, High Energy Physics - Phenomenology, High Energy Physics - Experiment (hep-ex), symbols.namesake, High Energy Physics - Phenomenology (hep-ph), Quantum electrodynamics, symbols, High Energy Physics::Experiment, Wave function, X(3872)
Abstract

A multichannel Schr\"odinger equation with both quark-antiquark and meson-meson components, using a harmonic-oscillator potential for $q\bar{q}$ confinement and a delta-shell string-breaking potential for decay, is applied to the axial-vecor $X(3872)$ and lowest vector charmonia. The model parameters are fitted to the experimental values of the masses of the $X(3872)$, $J/\psi$ and $\psi(2S)$. The wave functions of these states are computed and then used to calculate the electromagnetic decay widths of the $X(3872)$ into $J/\psi\gamma$ and $\psi(2S)\gamma$., Comment: 6 pages, 2 figures (3 plots), 3 tables, appolb style, Talk given by M. Cardoso at the "EEF70" Workshop on Unquenched Hadron Spectroscopy: Non-Perturbative Models and Methods of QCD, Coimbra, 1-5 Sept. 2014, Conference no. C14-09-01.4

Published
2015
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34. Problems with Meson Spectroscopy Involving Perturbative Loop Corrections

Author

K. P. Khemchandani, George Rupp, and E. van Beveren

Subjects
Physics, Particle physics, Nuclear Theory, Meson, High Energy Physics::Lattice, High Energy Physics::Phenomenology, FOS: Physical sciences, General Physics and Astronomy, Nuclear Theory (nucl-th), Loop (topology), High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), High Energy Physics::Experiment, Nuclear Experiment, Spectroscopy, Nuclear theory
Abstract

In this talk we review the limitations of including meson loops as perturbative corrections in a solvable quark model. We first discuss meson-meson scattering within a formalism which treats confined quark pairs and mesons on an equal footing. The interaction between the mesons proceeds through $s$-channel meson-exchange diagrams. Next, we develop a perturbative expansion of the model, and show that the resonance poles found in such a treatment, even by accounting for contributions up to fourth order, do not coincide with those obtained with the full model. We conclude that the resonance predictions based on perturbative approximations in quark models are not reliable, especially in those cases where the coupling to the scattering channels is large., Conference proceedings for EEF70, Workshop on Unquenched Hadron Spectroscopy:Non-Perturbative Models and Methods of QCD vs. Experiment

Published
2015
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35. The light scalar mesons within quark models

Author

E. van Beveren, George Rupp, Nicholas Petropoulos, and Frieder Kleefeld

Subjects
Physics, Quark, Particle physics, Meson, Basis (linear algebra), 010308 nuclear & particles physics, Scattering, High Energy Physics::Lattice, Nuclear Theory, High Energy Physics::Phenomenology, Scalar (mathematics), FOS: Physical sciences, 01 natural sciences, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Bibliography, High Energy Physics::Experiment, Gravitational singularity, Color confinement, 010306 general physics
Abstract

Low-energy meson-meson scattering data are a powerful testing ground for quark models. Here, we describe the behaviour at threshold of S-wave scattering-matrix singularities. The majority of the full scattering-matrix mesonic poles stem from an underlying confinement spectrum. However, the light scalar mesons K0*(830), a0(980), f0(400-1200), and f0(980) do not, but instead originate in 3P0-barrier semi-bound states. We show that the behaviour of the corresponding poles is identical at threshold. In passing, the light-meson sector is given a firm basis., Comment: Plain LaTeX, 16 pages Contribution to the Second International Workshop on Hadron Physics, Effective Theories of Low Energy QCD, 25-29 September, 2002 (Coimbra, Portugal)

Published
2003
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36. Meson Form Factors in the Quark-Level LσM

Author

Michael D. Scadron, E. van Beveren, Frieder Kleefeld, and George Rupp

Subjects
Physics, Quark, Particle physics, Meson, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Nuclear Theory, Observable, Charge (physics), Nuclear physics, symbols.namesake, Pion, symbols, Radiative transfer, Feynman diagram, High Energy Physics::Experiment, Nuclear Experiment
Abstract

We study meson (π,Κ) form factors in general, and specialize at a later stage to a specific scheme, namely the quark‐level linear σ model (LσM). We compute a variety of electromagnetic and weak observables of light mesons, including pion and kaon form factors and charge radii, charged‐pion polarizabilities, semileptonic weak Κl3 decay, semileptonic weak radiative pion and kaon form factors, radiative decays of vector mesons, and nonleptonic weak Κ2π decay. We find good to very good agreement with experiment of all these predicted observables.

Published
2003
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37. SU(3) Mass Splittings for $\bar{q}q$ Mesons and $qqq$ Baryons

Author

Michael D. Scadron, E. van Beveren, George Rupp, and Frieder Kleefeld

Subjects
Physics, Particle physics, Meson, Octet, Bar (music), High Energy Physics::Lattice, Scalar (mathematics), Nuclear Theory, High Energy Physics::Phenomenology, FOS: Physical sciences, 020206 networking & telecommunications, 02 engineering and technology, Baryon, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, High Energy Physics::Experiment, Degeneracy (mathematics)
Abstract

By comparing SU(3)-breaking scales of linear mass formulae, it is shown that the lowest vector, axial-vector, and scalar mesons all have a $\bar{q}q$ configuration, while the ground-state octet and decuplet baryons are $qqq$. Also, the quark-level linear $\sigma$ model is employed to predict similar $\bar{q}q$ and $qqq$ states. Finally, the approximate mass degeneracy of the scalar $a_0$(980) and $f_0$(980) mesons is demonstrated to be accidental., Comment: 8 Pages, AIP Proc. Style; Contribution to the High-Energy Physics Workshop "Scalar Mesons: an Interesting Puzzle for QCD", May 16-18, 2003, SUNY Institute of Technology, Utica (NY)

Published
2003
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38. Measurement of the $K_{L}-K_{S}$ mass difference using semileptonic decays of tagged neutral kaons

Author

D. Garreta, M. Mikuž, F. Touchard, L. Tauscher, Marc Dejardin, L. Faravel, J. Derre, F. Pelucchi, A. Benelli, E. Machado, T. Schietinger, M. Chardalas, M.B. Chertok, R. Le Gac, Jeffrey Boone Miller, C. Felder, P. Weber, E. Aslanides, C. Touramanis, Christer Fuglesang, T. Lawry, Frixos A Triantis, K. Sarigiannis, Christopher Bee, H. Postma, A. Cody, Sp. Dedoussis, J. R. Fry, T. Geralis, P. Fassnacht, R. Ferreira-Marques, Panagiotis Kokkas, Claudio Santoni, G. S. Varner, Ch Yèche, F. Henry-Couannier, B. Eckart, C. Witzig, B.L. Roberts, I. Mandić, T. Nakada, G. Backenstoss, L. Sacks, I. Papadopoulos, E. Hubert, A. Filipčič, F. Blanc, A. Haselden, João Carvalho, K. Jon-And, D.A. Troster, O. Wigger, C. Kochowski, J. Duclos, Ch. Bula, T. Alhalel, B. Pagels, C.W.E. van Eijk, M. Dodgson, V. Bertin, M. Schafer, A. Go, D. Zimmerman, E. van Beveren, J. K. Bienlein, R.W. Hollander, W. Fetscher, T. Ruf, F. Montanet, R. Gamet, E. Rozaki, Ph. Schune, A. Soares, K. Jansson, O. Behnke, H.-J. Gerber, M. Fidecaro, W.G. Heyes, Mats Danielsson, R. Adler, F. Leimgruber, A. Schopper, S. Vlachos, P. Sanders, C. Thibault, P Harrison, M. Wolter, P.J. Hayman, P. Maley, A. Liolios, L.A. Schaller, J. Bennet, E. Cawley, Ioannis Evangelou, D. Francis, P. Gumplinger, L. Sakeliou, A.J.P.L. Policarpo, N. Manthos, E. Gabathuler, R. Rickenbach, P. Pavlopoulos, R. Kreuger, A. Apostolakis, G. Marel, A. Ealet, Michael C. Carroll, D. Zavrtanik, P. Bloch, H.U. Johner, Claude Guyot, P.-R. Kettle, C. Eleftheriadis, A. Angelopoulos, J. Pinto da Cunha, A. Onofre, P. Carlson, G. Chardin, Jean-Louis Faure, Stef. Charalambous, and G. Polivka

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Full data, Particle Physics - Experiment
Abstract

We report on a new measurement of the K L –K S mass difference Δm using the CPLEAR full data sample of neutral-kaon decays to e πν . The result is Δm =(0.5295±0.0020 stat ±0.0003 syst )×10 10 ℏ/s. It includes earlier data reported in R. Adler et al., CPLEAR Collaboration, Phys. Lett. B 363 (1995) 237. A measurement of the ΔS = ΔQ violating parameter Re( x ) is also obtained.

Published
1998

39. Upper limit for the branching ratio of K[sub S]→e[sup +]e[sup −] decay

Author

J. Pinto da Cunha, C. Eleftheriadis, Mats Danielsson, W. Fetscher, F. Montanet, E. Machado, E. Hubert, A.J.P.L. Policarpo, A. Apostolakis, A. Benelli, C.W.E. van Eijk, P.R. Kettle, L. Tauscher, F. Henry-Couannier, D. Zimmerman, A. Muller, O. Behnke, J. S. Miller, P. Weber, P. Carlson, M. Mikuž, M.B. Chertok, R. Le Gac, C. Thibault, F. Leimgruber, João Carvalho, A. Schopper, B. L. Roberts, P. Pavlopoulos, Marc Dejardin, Elie Aslanides, P.J. Hayman, Andrej Filipcic, E. van Beveren, T. Nakada, F. Blanc, A. Go, Sotirios Vlachos, Marcin Wladyslaw Wolter, J. Derre, O. Wigger, B. Pagels, A. Soares, T. Ruf, C. Touramanis, A. Angelopoulos, J. R. Fry, A. Haselden, Michael C. Carroll, Francois Touchard, R. Gamet, Frixos A Triantis, Kerstin Jon-And, C. Yeche, A. Ealet, R. Kreuger, G. Chardin, Nikolaos Manthos, P. Bargassa, A. Liolios, R.W. Hollander, H.-J. Gerber, D. Garreta, G. Backenstoss, P. Bloch, Lukas A. Schaller, Ioannis Evangelou, David Francis, L. Sakeliou, Igor Mandić, G. Marel, E. Cawley, A. Cody, L. Faravel, Panagiotis Kokkas, T. Schietinger, R. Ferreira-Marques, Ioannis Papadopoulos, M. Fidecaro, Stef. Charalambous, G. Polivka, P. Sanders, Danilo Zavrtanik, V. Bertin, M. Schafer, E. Gabathuler, and R. Rickenbach

Subjects
Nuclear physics, Physics, Particle physics, Positron, Branching fraction, Detector, Electron, Limit (mathematics), Particle identification, Calorimeter, Event reconstruction
Abstract

A measurement of the branching ratio for KS→e+e− decay was performed with the CPLEAR detector at LEAR. Full event reconstruction together with calorimeter e/π separation allowed for powerful background rejection and high signal acceptance. The analysis on the complete set of data yields the result: BR(KS→e+e−)

Published
1998
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40. CPLEAR results on the CP parameters of neutral kaons decaying to $\pi^+ \pi^- \pi^0$

Author

R. Le Gac, E. Aslanides, C. Touramanis, J. R. Fry, L. Tauscher, Frixos A Triantis, E. Machado, I. Papadopoulos, O. Behnke, L. Faravel, G. Backenstoss, Stef. Charalambous, G. Polivka, F. Leimgruber, A. Schopper, P.J. Hayman, M. Schafer, J. Pinto da Cunha, Igor Mandić, A. Benelli, C.W.E. van Eijk, E. Cawley, P. Weber, Nikolaos Manthos, Sotirios Vlachos, A. Go, Andrej Filipcic, A. Liolios, A. Angelopoulos, G. Chardin, P. Pavlopoulos, Claude Guyot, D. Garreta, P. Fassnacht, E. Hubert, P. Sanders, C. Felder, Mats Danielsson, R. Adler, Panagiotis Kokkas, A.J.P.L. Policarpo, V. Bertin, W. Fetscher, Marc Dejardin, T. Ruf, C. Thibault, H.-J. Gerber, O. Wigger, C. Eleftheriadis, Christopher Bee, Michael C. Carroll, M. Fidecaro, M. Mikuž, M.B. Chertok, Danilo Zavrtanik, D. Zimmerman, A. Cody, D. Francis, R. Kreuger, K. Jon-And, Marcin Wladyslaw Wolter, J. Derre, A. Apostolakis, F. Henry-Couannier, G. Marel, Claudio Santoni, T. Schietinger, Ioannis Evangelou, P. Bargassa, R. Gamet, Ch Yèche, B.L. Roberts, B. Eckart, L. Sakeliou, A. Haselden, P.-R. Kettle, João Carvalho, F. Montanet, R.W. Hollander, A. Muller, E. van Beveren, Ph. Schune, Per Carlson, A. Ealet, F. Touchard, R. Ferreira-Marques, T. Nakada, Lukas A. Schaller, A. Soares, F. Blanc, C. Kochowski, B. Pagels, Jeffrey Boone Miller, P. Bloch, E. Gabathuler, R. Rickenbach, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CPLEAR, Lorgeril, Jocelyne, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Complete data, [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], 010308 nuclear & particles physics, Branching fraction, Order (ring theory), 01 natural sciences, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], CP violation, 010306 general physics, Particle Physics - Experiment
Abstract

The CPLEAR experiment measured time-dependent decay-rate asymmetries of \PKz\ and \PaKz\ decaying to \pipmz\ in order to study the interference between the decay amplitudes of \PKzS\ --- either CP-violating or CP-conserving --- and the CP-conserving \PKzL\ decay amplitude. From the analysis of the complete data set we find for the CP-violating parameter \etapmz , % % $ \reeta = \left( -2 \pm 7 \mbox{\rm \ stat.\ } ^{+4}_{-1} \mbox{\rm \ syst.} \right) \times 10^{-3} , $ $ \imeta = \left( -2 \pm 9 \mbox{\rm \ stat.\ } ^{+2}_{-1} \mbox{\rm \ syst.} \right) \times 10^{-3} $ % % and for the CP-conserving parameter \lampmz , % % $ \relam = \left(+28 \pm 7 \mbox{\rm \ stat.\ } \pm 3 \mbox{\rm \ syst.} \right) \times 10^{-3} , $ $ \imlam = \left( -10 \pm 8 \mbox{\rm \ stat.\ } \pm 2 \mbox{\rm \ syst.} \right) \times 10^{-3}. $ % % From the latter, the branching ratio of the CP-conserving $\PKzS \rightarrow \pipmz $ decay is deduced to be % % $ \mathrm{B} = \left( 2.5 ^{+1.3}_{-1.0} \mathrm{\ stat.\ } ^{+0.5}_{-0.6} \mathrm{\ syst.\ } \right) \times 10^{-7}.

Published
1997

41. CPLEAR experiment at CERN: Measurement of CP, T and CPT in the neutral kaon system

Author

B. Eckart, C. Touramanis, J. R. Fry, Jeffrey Boone Miller, F. Blanc, Mats Danielsson, Sotirios Vlachos, T. Ruf, R. Adler, Frixos A Triantis, C. Kochowski, B. Pagels, L. Faravel, A. Angelopoulos, M. Mikuž, Marc Dejardin, E. Gabathuler, R. Rickenbach, O. Wigger, J. Pinto da Cunha, A. Haselden, P. Bloch, A. Benelli, C.W.E. van Eijk, A.J.P.L. Policarpo, A. Ealet, W. Fetscher, R.W. Hollander, G. Chardin, A. Muller, P. Weber, M.B. Chertok, D. Garreta, Ph. Schune, G. Backenstoss, Patrick Fassnacht, Lukas A. Schaller, F. Henry-Couannier, Stef. Charalambous, Ioannis Evangelou, Ioannis Papadopoulos, O. Behnke, M. Fidecaro, G. Polivka, R. Gamet, F. Leimgruber, Michael C. Carroll, A. Schopper, P.J. Hayman, Igor Mandić, P. Pavlopoulos, David Francis, R. Kreuger, Elie Aslanides, Claudio Santoni, C. Thibault, T. Nakada, L. Sakeliou, B. L. Roberts, C. Eleftheriadis, T. Schietinger, C. Felder, João Carvalho, Francois Touchard, C. Yeche, R. Ferreira-Marques, Panagiotis Kokkas, P.R. Kettle, L. Tauscher, Andrej Filipcic, Claude Guyot, E. Hubert, Kerstin Jon-And, Nikolaos Manthos, D. Zimmerman, A. Liolios, P. Carlson, F. Montanet, Christopher Bee, A. Go, A. Soares, P. Sanders, E. Machado, P. Bargassa, Danilo Zavrtanik, V. Bertin, M. Schafer, A. Apostolakis, R. Le Gac, Marcin Wladyslaw Wolter, E. van Beveren, J. Derre, A. Cody, H.-J. Gerber, G. Marel, E. Cawley, Lorgeril, Jocelyne, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CPLEAR, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Physics, Semileptonic decay, Particle physics, [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], CPT symmetry, Branching fraction, media_common.quotation_subject, Nuclear Theory, High Energy Physics::Phenomenology, Strangeness, 7. Clean energy, Asymmetry, Nuclear physics, Pion, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, Invariant mass, Nuclear Experiment, media_common, Lepton
Abstract

Using strangeness tagging at production time, CPLEAR measures K0/K0 time-dependent asymmetries in pionic and semileptonic kaon decays. From those, a set of parameters describing CP, T and CPT violation in neutral kaon mixing and decay can be determined. Strangeness tagging at decay time with the lepton charge allows for time-reversal violation to be directly observed with a significance of more than three standard deviations. The precision on each of the CPT violation parameters is discussed. The mass equality of the K0 and K0 is tested within 4.×10−19 GeV.

Published
1997
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42. Measurement of K$_{L}$-K$_{S}$ mass difference using semileptonic decays of tagged neutral kaons

Author

R. Adler, T. Alhalel, A. Angelopoulos, A. Apostolakis, E. Aslanides, G. Backenstoss, C.P. Bee, O. Behnke, A. Benelli, J. Bennet, V. Bertin, J.K. Bienlein, F. Blanc, P. Bloch, C. Bula, P. Carlson, M. Carroll, J. Carvalho, E. Cawley, S. Charalambous, M. Chardalas, G. Chardin, M.B. Chertok, A. Cody, M. Danielsson, S. Dedoussis, M. Dejardin, J. Derre, M. Dodgson, J. Duclos, A. Ealet, B. Eckart, C. Eleftheriadis, I. Evangelou, L. Faravel, P. Fassnacht, J.L. Faure, C. Felder, R. Ferreira-Marques, W. Fetscher, M. Fidecaro, A. Filipčič, D. Francis, J. Fry, C. Fuglesang, E. Gabathuler, R. Gamet, D. Garreta, T. Geralis, H.-J. Gerber, A. Go, P. Gumplinger, C. Guyot, P.F. Harrison, A. Haselden, P.J. Hayman, F. Henry-Couannier, W.G. Heyes, R.W. Hollander, E. Hubert, K. Jansson, H.U. Johner, K. Jon-And, P.-R. Kettle, C. Kochowski, P. Kokkas, R. Kreuger, T. Lawry, R. Le Gac, F. Leimgruber, A. Liolios, E. Machado, P. Maley, I. Mandić, N. Manthos, G. Marel, M. Mikuž, J. Miller, F. Montanet, T. Nakada, A. Onofre, B. Pagels, I. Papadopoulos, P. Pavlopoulos, F. Pelucchi, J. Pinto da Cunha, A. Policarpo, G. Polivka, H. Postma, R. Rickenbach, B.L. Roberts, E. Rozaki, T. Ruf, L. Sacks, L. Sakeliou, P. Sanders, C. Santoni, K. Sarigiannis, M. Schäfer, L.A. Schaller, T. Schietinger, A. Schopper, P. Schune, A. Soares, L. Tauscher, C. Thibault, F. Touchard, C. Touramanis, F. Triantis, D.A. Tröster, E. Van Beveren, C.W.E. Van Eijk, G. Varner, S. Vlachos, P. Weber, O. Wigger, C. Witzig, M. Wolter, C. Yeche, D. Zavrtanik, and D. Zimmerman

Subjects
Nuclear and High Energy Physics, Particle Physics - Experiment
Published
1995

43. CP, T, and CPT tests in neutral Kaon decays using tagged K0, K0at LEAR

Author

L. Faravel, C.W.E. van Eijk, E. Hubert, K. Sarigiannis, T. Alhalel, O. Behnke, H.-J. Gerber, Danilo Zavrtanik, G. Marel, Sp. Dedoussis, Marcin Wladyslaw Wolter, J. Derre, F. Montanet, Christopher Bee, G. Chardin, Jean-Louis Faure, D. Zimmerman, T. Lawry, E. Cawley, V. Bertin, D.A. Troster, F. Leimgruber, R. Le Gac, P. Carlson, A. Schopper, E. van Beveren, F. Blanc, C. Kochowski, M. Mikuž, L. Sacks, D. Garreta, G. Backenstoss, M. Schafer, J. S. Miller, Ioannis Evangelou, B. Pagels, P.J. Hayman, Panagiotis Kokkas, P. Gumplinger, L. Sakeliou, E. Machado, Michael C. Carroll, Marc Dejardin, Stef. Charalambous, B. Eckart, J. R. Fry, H. Postma, Elie Aslanides, F. Pelucchi, J. Duclos, P.R. Kettle, L. Tauscher, G. Polivka, Patrick Fassnacht, Ch. Bula, C. Witzig, Ph. Schune, A. Onofre, Sotirios Vlachos, C. Touramanis, T. Ruf, R. Kreuger, Andrej Filipcic, P. Sanders, M. Fidecaro, A. Angelopoulos, W. Fetscher, Frixos A Triantis, T. Nakada, A. Go, K. Jansson, J. Pinto da Cunha, Kerstin Jon-And, Nikolaos Manthos, C. Thibault, A. Soares, B. L. Roberts, C. Eleftheriadis, C. Felder, A. Liolios, R. Gamet, H.U. Johner, Claudio Santoni, Claude Guyot, C. Yeche, T. Geralis, F. Henry-Couannier, Lukas A. Schaller, E. Rozaki, O. Wigger, Francois Touchard, J. Bennet, A.J.P.L. Policarpo, R. Ferreira-Marques, P. Weber, João Carvalho, David Francis, Igor Mandić, A. Cody, M. Dodgson, E. Gabathuler, R. Rickenbach, P. Maley, P. Pavlopoulos, A. Apostolakis, P. Bloch, A. Haselden, A. Ealet, R.W. Hollander, M. Chardalas, M.B. Chertok, Mats Danielsson, and R. Adler

Subjects
Nuclear physics, Physics, Particle physics, Large Hadron Collider, media_common.quotation_subject, Strangeness, Asymmetry, media_common
Abstract

The CPLEAR experiment at CERN measures particle‐antiparticle asymmetries of strangeness‐tagged K0, K0 decays to two‐pion, three‐pion, and semileptonic final states. The technique of CPLEAR is an alternative approach to previous CP‐violation studies. It provides complementary information with different systematics and gives access to novel measurements. The precision of the CP‐violation parameters η+− for π+π−, η+−0 for π+π−π0 and of the T‐violation parameter eT for π±e∓ν will be discussed for the data taken between 1990–1992.

Published
1995
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44. [Untitled]

Author

George Rupp, E. van Beveren, and Susana Coito

Subjects
Quantum chromodynamics, Physics, Meson, High Energy Physics::Phenomenology, C++ string handling, General Physics and Astronomy, Resonance, High Energy Physics::Experiment, Atomic physics, Type (model theory), Wave function, X(3872), Bar (unit)
Abstract

Because of the controversial X(3872) meson's very close proximity to the $D^0\bar{D}^{*0}$ threshold, this charmonium-like resonance is often considered a meson-meson molecule. However, a molecular wave function must be essentially of a meson-meson type, viz. $D^0\bar{D}^{*0}$ in this case, with no other significant components. We address this issue by employing a simple two-channel Schrodinger model, in which the $J^{PC}=1^{++}$ $c\bar{c}$ and $D^0\bar{D}^{*0}$ channels can communicate via the $^3P_0$ mechanism, mimicked by string breaking at a sharp distance $a$. Thus, wave functions and their probabilities are computed, for different bound-state pole positions approaching the $D^0\bar{D}^{*0}$ threshold from below. We conclude that at the PDG X(3872) mass and for reasonable values of $a$, viz. 2.0 to 3.0 GeV$^{-1}$, the $c\bar{c}$ component remains quite substantial and certainly not negligible, despite accounting for only about 6 to 10% of the total wave-function probability, owing to the naturally long tail of the $D^0\bar{D}^{*0}$ component.

Published
2012
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45. A study of T violation via the semileptonic decays of neutral kaons in CPLEAR

Author

E. Gabathuler, Stef. Charalambous, R. Rickenbach, L. Tauscher, M. Mikuž, G. Polivka, P. Sanders, E. Machado, A.J.P.L. Policarpo, I. Evangelou, R. Ferreira-Marques, Panagiotis Kokkas, B. Eckart, S. Szilagyi, P.F. Harrison, E. Rozaki, Ph. Schune, P. Fassnacht, J. Bennet, C. Witzig, A. Ealet, A. Schopper, K. Sarigiannis, H. J. Johner, H. Postma, M. Van den Putte, Sp. Dedoussis, Andrej Filipcic, C. Thibault, A. Go, P. Bloch, T. Geralis, Danilo Zavrtanik, R. Gamet, C. Eleftheriadis, Elie Aslanides, A. Apostolakis, P.J. Hayman, Igor Mandić, R. Kreuger, L.A. Schaller, J. Duclos, B.L. Roberts, D. Zimmerman, Christopher Bee, P.-R. Kettle, Jeffrey Boone Miller, P. Carlson, Claude Guyot, Francois Touchard, V. Bertin, D.A. Troster, C. Felder, A. Soares, Mats Danielsson, R. Adler, Ch. Bula, T. Ruf, O. Wigger, C.W.E. van Eijk, Andras Kerek, M. Schafer, C. Yeche, J. Pinto da Cunha, G. Chardin, Jean-Louis Faure, W. Fetscher, K. Jansson, D. Garreta, J. Kern, C. Kochowski, J. K. Bienlein, G. Backenstoss, M. Fidecaro, J.C. Dousse, T. Alhalel, B. Pagels, C. Touramanis, M. Dejardin, Christer Fuglesang, Frixos A Triantis, E. van Beveren, R.W. Hollander, Kerstin Jon-And, P. Gumplinger, M. Chardalas, Nikolaos Manthos, R. Le Gac, H.-J. Gerber, A. Onofre, P. Pavlopoulos, A. Liolios, P. Maley, W.G. Heyes, A. Angelopoulos, Marcin Wladyslaw Wolter, J. Derre, F. Pelucchi, T. Lawry, S. Vlachos, G. Marel, E. Cawley, J. R. Fry, G. S. Varner, L. Sakeliou, L. Faravel, L. Sacks, P. Weber, Claudio Santoni, João Carvalho, F. Montanet, M. Dodgson, T. Nakada, David Francis, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CPLEAR, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], CP violation, 010306 general physics, 01 natural sciences
Abstract

The method for studying semileptonic neutral kaon decays at CPLEAR is presented together with a preliminary data analysis. For the first time a direct determination of T violation is shown to be possible and low statistics results are given. From the same data the K(L)-K(S) mass difference, DELTAm, the CP violation parameter of K(S), epsilon(S), and the parameter x testing the DELTAS = DELTAQ rule are also obtained. Nuclear Physics A

Published
1992

46. Possible ψ(5S), ψ(4D), ψ(6S), and ψ(5D) signals in \mth{\Lambda_{\rm c}\bar{\Lambda}_{\rm c}}

Author

E. van Beveren, George Rupp, Xiang Liu, and Rita Coimbra

Subjects
Physics, 010308 nuclear & particles physics, 0103 physical sciences, General Physics and Astronomy, High Energy Physics::Experiment, State (functional analysis), 010306 general physics, Lambda, 01 natural sciences, Mathematical physics, Bar (unit)
Abstract

It is shown that the Λc+Λc- signal recently reported by the Belle Collaboration (Phys. Rev. Lett., 101 (2008) 172001) contains clear signs of the ψ(5S) and the ψ(4D) c--> vector states, and also some indication for the masses and widths of the ψ(6S) and ψ(5D). Moreover, it is argued that the threshold behaviour of the Λc+Λc- cross-section suggests the presence of the hitherto undetected ψ(3D) state not far below the Λc+Λc- threshold.

Published
2009
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49. Canonical formalism for the relativistic harmonic oscillator

Author

C. Dullemond and E. van Beveren

Subjects
Physics, symbols.namesake, Theory of relativity, Classical mechanics, Geodesic, Differential equation, Electromagnetism, symbols, Elementary particle, Hamiltonian (quantum mechanics), Harmonic oscillator, Mathematical Operators
Abstract

A Hamiltonian and its associated Lagrangian are presented for classical relativistic point particles which carry out harmonic oscillations inside a spherical cavity of well-defined radius. It is shown that the particles follow geodesics in an alternative metric. The relevance of the model for the description of hadrons is discussed. Electromagnetism can be introduced in the usual way.

Published
1983
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50. Quark-gluon model with conformal symmetry

Author

Th. A. Rijken, E. van Beveren, and C. Dullemond

Subjects
Quark, Quantum chromodynamics, Physics, Theoretical physics, Particle physics, Conformal symmetry, Spontaneous symmetry breaking, High Energy Physics::Phenomenology, Hadron, Quark–gluon plasma, High Energy Physics::Experiment, Color confinement, Gluon
Abstract

ASO4,2 conformally symmetric model is presented for strong interactions at low energies. In order to obtain a realistic description of interacting gluons and quarks, two Higgs fields are introduced which break theSO4,2 symmetry spontaneously intoSO3,2 andSO3⊗SO2 symmetry, respectively. We obtain an alternative flat metric, invariant under rotations and translations which leave a preferred time-like geodesic invariant. In terms of this metric quarks and gluons carry out harmonic oscillations with universal frequency ν=(2πR)−1 within a spherical cavity of radiusR. This leads to a hadron spectrum with universal level spacinghν, which is in agreement with our earlier observations.

Published
1984
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