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1. Investigating the influence of bending stiffness and processing parameters on single-leg bending geometries of additively manufactured composites

Author

T. Stiller, R.C. Kerschbaumer, C. Waly, B. Zink, J. Slapnik, and G. Pinter

Subjects
Additive manufacturing, Polymers, Multi-material, Single leg bending, Bonding strength, Technology
Abstract

In less than a decade, additive manufacturing technologies have been developed so successfully that they already produce small and medium-sized lot sizes of prototypes or customised components in the industry. With its new possibilities such as combining materials and technologies, the benefits of different technologies can be merged and broaden future application fields. One way is to print with one technology on a part produced by another. Thus, a thermally bonded part composed of, e.g., selectively sintered and material-extruded components can be created. This combination of technologies was considered in this study to investigate the bonding strength of extrusion-based layers on selectively sintered surfaces and the impact of nozzle temperature, orientation, and thickness of imprinted materials. The extrusion-based layers covered stiff (fibre-reinforced polyamide) and soft (thermoplastic polyurethane) material properties with pre-cracked single-leg bending (SLB) specimens to study their effect on delamination tendencies. This combination of materials and additive manufacturing technologies has not yet been studied for the SLB testing method. The scope of this study is to obtain more information on how relatively hard-hard and hard-soft combinations behave for this special testing method. The results of this testing method were evaluated using two different fracture mechanical approaches to determine the energy release rate. A clear trend towards an improved bonding, thus, higher values, was found for higher nozzle temperatures. Furthermore, a limitation regarding the required bending stiffness of the composites was found. Overall, the single-leg bending testing method enables a relative ranking for material combinations with a certain bending stiffness.

Published
2024
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2. Prediction of polyethylene density from FTIR and Raman spectroscopy using multivariate data analysis

Author

M. Bredács, C. Barretta, L.F. Castillon, A. Frank, G. Oreski, G. Pinter, and S. Gergely

Subjects
Polyethylene, Density prediction, Recycling, FTIR-ATR and Raman spectroscopy, Multivariate data analysis, PCA and PLS models, Polymers and polymer manufacture, TP1080-1185
Abstract

To contribute to the targeted 10 million tons per year of recycled plastic in Europe by 2025 and to improve the mechanical sorting degree of polyethylene (PE) products, density prediction models were developed from Fourier transform infrared-attenuated total reflectance (FTIR-ATR) and Raman spectroscopic data. State-of-the-art sorting in mechanical recycling provides separated polymer classes, however an improved classification with specific chemical and physical features such as density or melt flow rate has not been developed yet.Applying multivariate data analysis (MVDA) on the spectral datasets of 10 different PE materials, one FTIR-ATR and two Raman spectra based partial least square (PLS) density models were developed. However, whereas all three models are applicable to predict PE density accurately, the Raman models have shown some advantages. Firstly, less principle components (PC) are needed and secondly the density can be assessed with higher accuracy, due to the more robust cross-validated PLS model. Moreover, the obtained PC-s indicate that in the FTIR-ATR model the CH3/CH2 ratio, while in the Raman model the CH2, CH and the crystalline C–C bands can be correlated with the PE density. The most accurate PLS model was obtained from the 1500-1000 cm−1 Raman shift region. The developed models could improve the density based mechanical separation of PE and consequently increase the quality of recycled and reprocessed PE products.

Published
2021
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3. Functional mechanical metamaterial with independently tunable stiffness in the three spatial directions

Author

M. Fleisch, A. Thalhamer, G. Meier, I. Raguž, P.F. Fuchs, G. Pinter, S. Schlögl, and M. Berer

Subjects
Neural network, Design, Mechanical testing, Additive manufacturing, Numerical, Materials of engineering and construction. Mechanics of materials, TA401-492
Abstract

Mechanical metamaterials with variable stiffness recently gained a lot of research interest, as they allow for structures with complex boundary and load conditions. Herein, we highlight the design, additive manufacturing, and mechanical testing of a new kind of bending-dominated metamaterial. By advancing from well-established mechanical metamaterials, the proposed geometry allows for varying the stiffness in the three spatial directions independently. Therefore, structures with different orientational properties can be designed, ranging from isotropic to anisotropic structures, including orthotropic structures. The compression modulus can be varied in the range of several orders of magnitude. Gradual transitions from one unit cell to the next can be realized, enabling smooth transitions from soft to hard regions. Specimens have been additively manufactured with acrylic resins and polylactic acid using Digital Light Processing and Fused Filament Fabrication, respectively. Two different numerical models have been employed using ABAQUS to describe the mechanical properties of the structure and verified by the experiments. Compression tests were performed to investigate the linear elastic properties of isotropic structures. Numerical models, based on three-point-bending test data, have been employed to study orthotropic structures. Compression test results for orthotropic and anisotropic structures are shown to highlight the independent variability. The manufacturing of the structures is not limited to the presented techniques and materials but can be expanded to all available additive manufacturing techniques and their respective materials. For a video of the compression tests of a specimen with three different compression moduli along the spatial axes, see the Supplementary Data available online.

Published
2021
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4. Fatigue Fracture Properties and Morphology of Polyoxymethylene (POM) Plates Produced under Moderate Processing Conditions

Author

M. Berer, M. Halb, M. Feuchter, G. Pacher, and G. Pinter

Subjects
Chemical technology, TP1-1185
Abstract

The present study was inspired by different industry projects in which a strong dependence of the fatigue fracture performance of POM on the processing conditions was observed. To examine the relationships under more reproducible conditions, plates of two different POM homopolymer resins (one significantly nucleated) were produced by compression molding and by injection molding under moderate conditions. For the injection molding, three different mold temperatures were used. At specific locations, the plates were analyzed concerning their hierarchical structure on the micro- and nanolevel and concerning their fatigue fracture performance. For the fatigue fracture performance, the dependence on the processing conditions was rather small for the nucleated resin but much more significant for the other resins. This dependence could not be related to morphological effects only, and thus, a combined effect of morphology and residual stresses was assumed.

Published
2018
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8. Functional mechanical metamaterial with independently tunable stiffness in the three spatial directions

Author

G. Meier, G. Pinter, I. Raguž, Sandra Schlögl, A. Thalhamer, M. Berer, P.F. Fuchs, and Mathias Fleisch

Subjects
Numerical, Materials science, Design, Additive manufacturing, Mechanical Engineering, Acoustics, Linear elasticity, Isotropy, Metamaterial, Stiffness, Mechanical testing, Fused filament fabrication, Orthotropic material, Compression (physics), Neural network, medicine, TA401-492, Mechanical metamaterial, General Materials Science, medicine.symptom, Materials of engineering and construction. Mechanics of materials
Abstract

Mechanical metamaterials with variable stiffness recently gained a lot of research interest, as they allow for structures with complex boundary and load conditions. Herein, we highlight the design, additive manufacturing, and mechanical testing of a new kind of bending-dominated metamaterial. By advancing from well-established mechanical metamaterials, the proposed geometry allows for varying the stiffness in the three spatial directions independently. Therefore, structures with different orientational properties can be designed, ranging from isotropic to anisotropic structures, including orthotropic structures. The compression modulus can be varied in the range of several orders of magnitude. Gradual transitions from one unit cell to the next can be realized, enabling smooth transitions from soft to hard regions. Specimens have been additively manufactured with acrylic resins and polylactic acid using Digital Light Processing and Fused Filament Fabrication, respectively. Two different numerical models have been employed using ABAQUS to describe the mechanical properties of the structure and verified by the experiments. Compression tests were performed to investigate the linear elastic properties of isotropic structures. Numerical models, based on three-point-bending test data, have been employed to study orthotropic structures. Compression test results for orthotropic and anisotropic structures are shown to highlight the independent variability. The manufacturing of the structures is not limited to the presented techniques and materials but can be expanded to all available additive manufacturing techniques and their respective materials. For a video of the compression tests of a specimen with three different compression moduli along the spatial axes, see the Supplementary Data available online.

Published
2021

11. Ballroom dancing is more intensive for the female partners due to their unique hold technique

Author

A Cselko, Márk Váczi, Tamas Atlasz, Éva Tékus, G Pinter, Mónika Kaj, Márta Wilhelm, and D Balatincz

Subjects
Adult, Male, medicine.medical_specialty, Adolescent, Physical Exertion, Posture, Ballroom, Biology, Young Adult, 03 medical and health sciences, Oxygen Consumption, 0302 clinical medicine, Heart Rate, Physiology (medical), Heart rate, medicine, Humans, Dancing, Treadmill, Sex Characteristics, 030222 orthopedics, Ballroom dancing, 030229 sport sciences, Athletes, Exercise Test, Physical therapy, Female, Demography
Abstract

In this study, we tested the hypotheses that, relative to the maximum capacities, ballroom dancing is more intensive for females than males, and that the hold technique (female vs. male) regulates dancing intensity. Ten dance couples were tested in a maximal treadmill test, competition simulation, and stationary dance hold position. Peak heart rate and relative oxygen consumption were measured during the tests, except that oxygen consumption was not measured during competition simulation. Regardless of gender, heart rate increased similarly in the treadmill test and in the competition simulation. In the treadmill test, females achieved an oxygen consumption of 78% of the males (p p

Published
2016

12. [Adaptation to intermittent hypoxia-hyperoxia improves cognitive performance and exercise tolerance in elderly]

Author

U, Bayer, O S, Glazachev, R, Likar, M, Burtscher, W, Kofler, G, Pinter, H, Stettner, S, Demschar, B, Trummer, and S, Neuwersch

Subjects
Aged, 80 and over, Cognition, Exercise Tolerance, Oxygen Consumption, Double-Blind Method, Humans, Walk Test, Hyperoxia, Middle Aged, Hypoxia, Aged, Physical Conditioning, Human
Abstract

For improvements in exercise tolerance and cognitive function in geriatric patients Multimodal training programs (MTP) are used as combination of physiotherapy, occupational therapy and cardiovascular training. Intermittent Hypoxic-Hyperoxic Training (IHHT), a modified type of intermittent hypoxic training (IHT) is proposed to be included in MTP to elicit more pronounced beneficial effects in exercise tolerance and cognitive functions of geriatric patients likely by an additional pathway than a single MTP. Thirty four patients of the Geriatric Day Clinic aged between 64 and 92 years participated in the placebo controlled clinical trial. They were randomly assigned to receive MTP plus IHHT (experimental group - EG) or MTP plus placebo-breathing through a machine face mask (control group - CG) in a double blind fashion. Before and after the interventions course cognitive performance was assessed by the Dementia-Detection-Test (DemTect) and the Clock-Drawing-Test (CDT), and functional exercise capacity - by the total distance of 6-Minute-Walk-Test (6MWT). After IHHT combined with MTP cognitive performance (DemTect) increased significantly when compared to NG (+16,7 % vs. +0,39 %, p0,001). The CDT indicated similar results with a significant increase in the EG while the score of the CG even decreased (+10,7 % vs. -8%, p=0,031). Concerning the functional exercise capacity, both groups improved the total distance in the 6MWT but with a significantly larger increase in the EG compared to the CG (+24,1 % vs. +10,8 %, p=0,021). In addition, there was a significant relationship between the changes of the 6MWT and the DemTect Scores and the CDT. IHHT contributed significantly to improvements in cognitive performance and exercise capacity in elderly performing MTP. IHHT sessions are considered to be easily applicable to and well tolerated by geriatric patients up to 92 years.Для поддержания физической работоспособности и когнитивных функций у пожилых пациентов применяются мультимодальные реабилитационные программы (МРП) на основе физических тренировок, физиотерапевтических процедур, психологического тренинга и пр. Для повышения эффективности МРП у пожилых предложено применять новый вариант адаптации к интервальной нормобарической гипоксии — метод интервальных гипоксически-гипероксических тренировок (ИГГТ). В плацебо-контролируемом клиническом исследовании приняли участие 34 пациента 64-92 лет дневного гериатрического стационара Клиники Клагенфурта (Каринтия, Австрия), рандомизированных на две группы: опытная (ОГ) — получившие МРП и курс ИГГТ; контрольная (КГ) — прошедшие курс МРП при имитации процедур ИГГТ. До и после курса реабилитации когнитивные функции и нагрузочная выносливость пациентов были оценены с применением тестов определения деменции (DemTect), рисования часов (Clock-drawing Test), а также проведением 6-минутного теста ходьбы (6MWT). При проведении курса ИГГТ когнитивные возможности пациентов ОГ значимо улучшились по сравнению с пациентами КГ: прирост значений в тесте деменции составил +16,7 % (в КГ +0,39 %, p0,001), в тесте рисования часов +10,7 % (в КГ −8 %, p=0,031). Дистанция, пройденная в 6-минутном тесте, увеличилась в обеих группах, однако достоверно больше в ОГ — +24,1 % (в КГ +10,8 %, p=0,021). Выявлены прямые значимые корреляции между приростом в нагрузочной толерантности и когнитивных тестах. Таким образом, включение процедур адаптации к интервальной гипоксии-гипероксии в МРП у пожилых приводит к значимому повышению их эффективности, что проявляется в улучшении когнитивных функций и физической выносливости. Процедуры ИГГТ хорошо переносятся, не вызывают побочных эффектов.

Published
2017

13. [Palliative care in nursing homes : Results of a survey about knowledge and self-efficacy of nursing staff]

Author

O, Kada, H, Janig, G, Pinter, K, Cernic, and R, Likar

Subjects
Adult, Aged, 80 and over, Male, Middle Aged, Self Efficacy, Nursing Homes, Geriatric Nursing, Austria, Surveys and Questionnaires, Homes for the Aged, Humans, Female, Nursing Staff, Clinical Competence, Education, Nursing, Diploma Programs, Nurse-Patient Relations, Aged
Abstract

Nursing homes are confronted more and more with palliative care patients, which present a challenge for nursing and medical personnel. Deficits in the palliative care of geriatric patients have been repeatedly demonstrated and many nursing home residents, especially those suffering from dementia, are undersupplied regarding pain management.The present study was carried out to measure the knowledge and self-efficacy of nursing staff in the province of Carinthia (Austria) regarding palliative care of nursing home residents.A total of 330 nursing personnel were surveyed using the Bonn test for knowledge in palliative care (BPW), which measures knowledge and self-efficacy in nursing home personnel. In addition to descriptive analyses, the effects of the professional group (registered nurses vs. nursing assistants) and working experience were tested.On average a little more than half of the knowledge items were answered correctly. Nurses' self-efficacy was high. Registered nurses exhibited more knowledge and higher self-efficacy compared to nursing assistants. Effects of working experience could only be demonstrated regarding self-efficacy.The results are to a large extent in line with results from Germany and indicate the necessity of interventions for improving nurses' knowledge as a major basis for adequate palliative care in nursing home residents.

Published
2017

14. Thermoforming of Polymer Laminate Films: Thermo-Viscoelastic Characterization

Author

G. Pilz, E. Truszkiewicz, G. Pinter, and D. Tscharnuter

Subjects
chemistry.chemical_classification, Digital image correlation, Materials science, chemistry, Strain (chemistry), Polymer, Composite material, Anisotropy, Thermoforming, Viscoelasticity, Thermal expansion, Characterization (materials science)
Abstract

The thermo-viscoelastic behavior of a polymer laminate film was characterized by mechanical measurements to obtain data for material modeling. The strain was measured using digital image correlation. The film is anisotropic and sustains uniaxial strains up to 60%. Additionally, the thermal expansion was measured for both materials that form the laminate.Copyright © 2015 by ASME

Published
2015

15. [Pain measurement in cognitively impaired patients with the Doloshort scale]

Author

R, Likar, W, Pipam, S, Neuwersch, M, Köstenberger, G, Pinter, C, Gatternig, and J, Marksteiner

Subjects
Aged, 80 and over, Male, Observer Variation, Psychometrics, Reproducibility of Results, Documentation, Translating, Nursing Homes, Germany, Homes for the Aged, Humans, Cognitive Dysfunction, Dementia, Female, Chronic Pain, Mental Status Schedule, Aged, Pain Measurement
Abstract

Until recently the measurement of pain in cognitively impaired patients represented a neglected field in the diagnostics and treatment of pain. Investigations indicate a prevalence of pain in nursing home residents of between 45 % and 80 %.This study investigated the reliability of the German translation of the Doloshort scale and compared it with the visual analog scale (VS). The aim of this study was to determine the practical applicability of this scale in the clinical routine and to calculate the intrarater reliability (retest) and interrater reliability.The interrater and intrarater reliability of the Doloshort scale was between 0.949 and 0.970. There was a highly significant correlation between the values of the Doloshort scale and the VAS.The Doloshort scale is a well suited measurement instrument for the evaluation of pain in cognitively impaired patients. Because of the short form only simple instructions are necessary and it has a high acceptance with users.

Published
2015

19. Palliative Competence in emergency medicine

Author

R. Likar, G. Pinter, M. Kostenberger, and S. Nuewersch

Subjects
Competence (law), medicine.medical_specialty, business.industry, Family medicine, Emergency medicine, medicine, Medical emergency, business, medicine.disease
Published
2015

20. Finite renormalizations in the Epstein Glaser framework and renormalization of theS-matrix ofΦ4-theory

Author

G. Pinter

Subjects
Renormalization, Physics, Formalism (philosophy of mathematics), General Physics and Astronomy, Adiabatic process, S-matrix, Mathematical physics
Abstract

A formula describing finite renormalizations is derived in the Epstein-Glaser formalism and an explicit calculation of finite counterterms in $\Phi ^4$-theory is performed. The Zimmermann identities and the action principle for changes of parameters in the interaction are presented independent of the adiabatic limit.

Published
2001

21. [Untitled]

Author

G. Pinter

Subjects
Pure mathematics, Quantum affine algebra, Quantum group, Mathematics::Rings and Algebras, Statistical and Nonlinear Physics, Representation theory of Hopf algebras, Hopf algebra, Quasitriangular Hopf algebra, Filtered algebra, Mathematics::Quantum Algebra, Division algebra, Mathematics::Mathematical Physics, Cellular algebra, Computer Science::Databases, Mathematical Physics, Mathematics
Abstract

We show how the Hopf algebra structure of renormalization discovered by Kreimer can be found in the Epstein–Glaser framework without using an analogue of the forest formula of Zimmermann.

Published
2000

23. Measurement of the decay distribution of η′ → π+π−γ and evidence for the box anomaly

Author

S. Spanier, C. Kolo, H. Matthäy, R. Hackmann, D. Walther, C.A. Baker, F. Walter, M. Benayoun, C. Regenfus, U. Strohbusch, C. Straßburger, K. Peters, A. Cooper, L. Montanet, B.S. Zou, H. Kalinowsky, B. Kalteyer, J. Meier, J. Lüdemann, K. Beuchert, M. A. Faessler, I. Scott, M. Lakata, S. Resag, R.P. Haddock, Eberhard Klempt, C.J. Batty, D. Jamnik, D. Engelhardt, T. Kiel, C. Pietra, U. Thoma, C. Hodd, P. Schmidt, C. Holtzhaußen, A. Abele, K.M. Crowe, Herbert Koch, J. Adomeit, W. Dünnweber, R. McCrady, Claude Amsler, Michael Doser, M. Heinzelmann, A. Berdoz, J. Brose, J. Kisiel, S. Bischoff, O. Cramer, Pàl Hidas, G. Pinter, P. Blüm, J. Reißmann, C. N. Pinder, S. v. Dombrowski, H. Stöck, T. Case, R. Ouared, D.V. Bugg, M. Herz, C. A. Meyer, C. Völcker, K. Braune, Marcel Kunze, W. Roethel, F. Ould-Saada, M. Tischhäuser, T. Degener, N.P. Hessey, B. Kämmle, N. Djaoshvili, U. Wiedner, D. Urner, R. Landua, F.H. Heinsius, P. Kammel, B.M. Barnett, M. Suffert, R. Seibert, and P. Giarritta

Subjects
Pseudoscalar, Physics, Nuclear physics, Quantum chromodynamics, Crystal, Nuclear and High Energy Physics, Distribution (mathematics), Anomaly (physics), Atomic physics, Constant (mathematics)
Abstract

The distribution of m ( π + π − ) in the decay η ′ → π + π − γ has been measured with the Crystal Barrel detector. The results are based on a total of 7392 observed η′ decays. The box anomaly constant is extracted from this and its value is found to agree well with theoretical expectations. The pseudoscalar nonet parameters ( f 1 , f 8 and θ PS ) are determined. Finally, we find that there is a problem of consistency between QCD and the standard VDM assumption.

Published
1997

24. High-mass ϱ-meson states from p̄d-annihilation at rest into π−π0π0pspectator

Author

M. Suffert, J. Kisiel, M. A. Faessler, J. Adomeit, R. Seibert, R.P. Haddock, Herbert Koch, P. Kammel, P. Birien, N. Djaoshvili, P. Schmidt, U. Wiedner, B.M. Barnett, R. Landua, C. A. Meyer, W. Dünnweber, R. McCrady, F.H. Heinsius, C.J. Batty, N.P. Hessey, J. Brose, G. Pinter, K.M. Crowe, K. Beuchert, A. Noble, I. Scott, J. Reißmann, C. Regenfus, C. Holtzhaußen, C. N. Pinder, A. Berdoz, S. v. Dombrowski, D. S. Armstrong, C. Völcker, W. Roethel, A. Cooper, P. Blüm, P. Giarritta, D. Jamnik, H. Matthäy, D. Engelhardt, M. Tischhäuser, S. Bischoff, L. Montanet, D.V. Bugg, Marcel Kunze, Michael Doser, A. Abele, B. Kämmle, K. Peters, M. Lakata, S. Resag, F. Ould-Saada, M. Herz, Eberhard Klempt, D. Walther, T. Case, T. Kiel, H. P. Dietz, U. Strohbusch, C. Straßburger, U. Thoma, T. Degener, K. Braune, J. Lüdemann, D. Urner, Claude Amsler, R. Ouared, H. Stöck, O. Cramer, Pàl Hidas, S. Spanier, C. Kolo, R. Hackmann, C.A. Baker, F. Walter, M. Benayoun, B.S. Zou, H. Kalinowsky, B. Kalteyer, and J. Meier

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Annihilation, Meson, Deuterium, Partial wave analysis, High mass, Neutron, Atomic physics
Abstract

A study of p -annihilation in liquid deuterium into π − π 0 π 0 and a spectator-proton is presented. A cut on the proton-momentum of ≤ 100 MeV/ c ensures that annihilation takes place on a quasi-free neutron. A partial wave analysis shows contributions from three vector mesons, with masses and widths of (763.7 ± 3.2; 152.8 ± 4.3), (1411 ± 14; 343 ± 20); (1780 −29 +37 ; 275 ± 45) MeV/ c 2 , respectively.

Published
1997

25. Further analysis of , ηηπ0 and ηπ0π0 at rest

Author

M. Suffert, R. Seibert, C.A. Baker, T. Kiel, C. Strassburger, O. Cramer, M. Benayoun, G. Pinter, Kenneth M. Crowe, C. N. Pinder, D. S. Armstrong, Herbert Koch, P. Schmidt, J. Adomeit, L. Montanet, W. Dünnweber, C.J. Batty, C. Kolo, R. McCrady, Nigel Hessey, A. Berdoz, Ingrid U. Scott, N. Djaoshvili, B. Kaemmle, T. Case, D. Walther, B.S. Zou, C. Holtzhaussen, P. Blüm, Pàl Hidas, U. Strohbusch, M. A. Faessler, R.P. Haddock, A. V. Sarantsev, H. Matthaey, D.V. Bugg, J. Meier, C. Voelcker, J. Reissmann, H. P. Dietz, A. Cooper, K. Braune, M. Tischhaeuser, M. Lakata, P. Kammel, C. A. Meyer, F. H. Heinsius, P. Illinger, C. Regenfus, U. Thoma, S. Bischoff, M. Herz, M. Englert, W. Roethel, K. Beuchert, D. Jamnik, D. Engelhardt, and A. Abele

Subjects
Rest (physics), Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Dalitz plot
Published
1996

26. A study of f0(1500) decays into 4π0 in at rest

Author

S. v. Dombrowski, D. S. Armstrong, Herbert Koch, Pàl Hidas, U. Thoma, S. Spanier, C.J. Batty, C. Kolo, T. Case, F. Ould-Saada, G. Pinter, H. Matthäy, U. Wiedner, M. Tischhäuser, Michael Doser, R. Hackmann, R. Ouared, A. Cooper, M. A. Faessler, R.P. Haddock, P. Schmidt, I. Scott, K. Peters, D. Walther, F. H. Heinsius, T. Degener, U. Strohbusch, C. Straßburger, O. Cramer, L. Montanet, N.P. Hessey, C. A. Meyer, J. Lüdemann, W. Dünnweber, S. Bischoff, R. McCrady, J. Adomeit, D. Urner, Eberhard Klempt, S. Resag, J. Zoll, M. Lakata, T. Kiel, H. P. Dietz, P. Blüm, M. Suffert, R. Seibert, H. Stöck, B.S. Zou, Č. Zupančič, K. Braune, W. Röthel, D.V. Bugg, A. Noble, H. Kalinowsky, B. Kalteyer, J. Meier, C.A. Baker, N. Djaoshvili, F. Walter, Claude Amsler, M. Benayoun, A. Berdoz, C. Regenfus, Kenneth M. Crowe, J. Brose, J. Reißmann, P. Kammel, B.M. Barnett, M. Englert, B. Kämmle, P. Giarritta, K. Beuchert, D. Jamnik, C. Holtzhaußen, D. Engelhardt, R. Landua, J. Kisiel, A. Abele, M. Herz, C. Völcker, Marcel Kunze, and C. N. Pinder

Subjects
Crystal, Physics, Rest (physics), Nuclear and High Energy Physics, Angular distribution, Amplitude, Phase space, Mass spectrum, Atomic physics
Abstract

Crystal Barrel data on p p → 5π 0 at rest are presented. Mass spectra for 2π0 combinations, 3π0 and 4π0 and decay angular distributions all differ significantly from phase space. We present several ways of fitting the data. All agree on the definite presence of the f0(1500), observed in its 4π0 decay mode. It can decay into ππ(1300) and into σσ where σ stands for the full ππ S-wave amplitude.

Published
1996

27. Evidence for two isospin zeroJ PC=2−+ mesons at 1645 and 1875 MeV

Author

M. Englert, N.P. Hessey, F. Ould-Saada, Pàl Hidas, M. Suffert, R. Seibert, T. Degener, A. Cooper, K. Beuchert, N. Djaoshvili, D. Urner, U. Wiedner, L. Montanet, D. Jamnik, D. Engelhardt, C. Regenfus, M. Herz, W. Roethel, I. Scott, R. Landua, F. H. Heinsius, K. Peters, C. Holtzhaußen, Herbert Koch, D. Walther, P. Giaritta, K. Braune, J. Brose, J. Kisiel, J. Reißmann, M. Tischhäuser, U. Thoma, C. A. Meyer, B. Kämmle, Eberhard Klempt, A. Noble, Michael Doser, R. Ouared, T. Kiel, H. P. Dietz, C. Völcker, T. Case, S. Bischoff, O. Cramer, H. Matthäy, U. Strohbusch, G. Pinter, C. N. Pinder, D. S. Armstrong, C. Straßburger, Marcel Kunze, Č. Zupančič, J. Lüdemann, Claude Amsler, S. Resag, C.J. Batty, E. Schäfer, H. Stöck, S. Ravndal, P. Kammel, B.M. Barnett, J. Adomeit, P. Blüm, D.V. Bugg, J. P. Merlo, S. von Dombrowski, M. Lakata, A. Berdoz, P. Illinger, B.S. Zou, H. Kalinowsky, B. Kalteyer, J. Meier, S. Spanier, C. Kolo, R. Hackmann, M. A. Faessler, R.P. Haddock, C.A. Baker, F. Walter, M. Benayoun, Kenneth M. Crowe, P. Schmidt, W. Dünnweber, and R. McCrady

Subjects
Nuclear physics, Physics, Physics and Astronomy (miscellaneous), Meson, Isospin, Zero (complex analysis), High mass, Dalitz plot, Resonance, Atomic physics, Rest frame, Bar (unit)
Abstract

Data on\(\bar pp \to \eta \pi ^0 \pi ^0 \pi ^0 \) taken at beam momenta of 1.2 and 1.94 GeV/c reveal evidence for twoI=0JPC=2−+ resonances inηππ. The first, at 1645±14(stat.)±15(syst.) MeV with width 180−21+40±25 MeV, decays toα2(1320)π withL=0. It may be interpreted as the\(q\bar q^1 \)D2 partner ofπ2(1670). A strong signal is also observed just above threshold inf2(1270)η withL=0. It is 11–22 times stronger than is expected for the high mass tail of the 1645 MeV resonance. It can be fitted as a second 2−+ resonance at 1875±20±35 MeV with width 200±25±45 MeV. A third resonance havingJPC=2++ is observed at 2135±20±45 MeV withΛ=250±25±45 MeV, decaying to botha2(1320)π andf2(1270)η withL=1. There is no evidence for resonances with decays toa0(980)π, ση orf0(980)η.

Published
1996

28. E decays to ηππ in annihilation at rest

Author

R. Bossingham, N. Djaoshvili, K. Beuchert, J. Brose, N. Winter, P. Blüm, D. Jamnik, N.P. Hessey, D. Engelhardt, S. Spanier, C. Kolo, R. Hackmann, M. A. Faessler, D.V. Bugg, R. Ouared, R.P. Haddock, R. Landua, I. Scott, P. Schmidt, Č. Zupančič, F. H. Heinsius, P. Giarritta, Pàl Hidas, C. Völcker, O. Cramer, J. Kisiel, W. Dünnweber, R. McCrady, C. A. Meyer, U. Wiedner, P. Birien, Michael Doser, C. Holzhaußen, M. Schütrumpf, B.S. Zou, E. Schäfer, F. Ould-Saada, Marcel Kunze, K. Braune, C. Regenfus, H. Kalinowsky, K. Peters, T. Case, H. Matthäy, H. Stöck, B. Kalteyer, C.A. Baker, Claude Amsler, M. Englert, A. Cooper, M. Tischhäuser, F. Walter, T. Degener, A. Noble, J. Zoll, M. Herz, M. Benayoun, U. Thoma, Kenneth M. Crowe, D. Urner, Herbert Koch, G. Pinter, B. M. Barnett, D. Walther, J. P. Merlo, U. Strohbusch, C. Straßburger, L. Montanet, J. Lüdemann, C.J. Batty, S. Ravndal, Eberhard Klempt, T. Kiel, H. P. Dietz, C. N. Pinder, S. v. Dombrowski, D. S. Armstrong, M. Lakata, B. Kämmle, P. Illinger, M. Suffert, and R. Seibert

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Angular distribution, Annihilation, Meson, Branching fraction, Isoscalar, Mass spectrum
Abstract

We have observed the ηπ + π − and ηπ 0 π 0 decay modes of the E meson in p p annihilation at rest into π + π − π 0 π 0 η . The mass and width of the E meson are 1409 ± 3 and 86 ± 10 MeV. The production and decay branching ratio is B( p p → Eππ)B(E → ηππ) = (3.3 ± 1.0) × 10 −3 . With a spin-parity analysis we determine that J P = 0 − . The observation of the ηπ 0 π 0 decay mode establishes that E is isoscalar ( C = +1). We find that E decays to η ( ππ ) s (where ( ππ ) s is an S-wave dipion) and πa 0 (980)(→ πη ) with a relative branching ratio of (78 ± 16) %. Using the K K π production and decay branching ratio measured earlier we determine that B[E → K K π] B[E → ηππ] = 0.61 ± 0.19 . A comparison with observations in radiative J Ψ decays suggests that E and ι η (1416) are identical.

Published
1995

29. Multicenter study of lipoprotein(a) and apolipoprotein(a) phenotypes in patients with end-stage renal disease treated by hemodialysis or continuous ambulatory peritoneal dialysis

Author

Gerd Utermann, U Lang, Paul König, Hans Dieplinger, Ulrich Neyer, Andreas Pribasnig, Florian Kronenberg, J Reitinger, G Pinter, and Martin Auinger

Subjects
Adult, Male, medicine.medical_specialty, Apolipoprotein B, Arteriosclerosis, medicine.medical_treatment, Apoprotein(a), Gastroenterology, Peritoneal dialysis, End stage renal disease, Peritoneal Dialysis, Continuous Ambulatory, Renal Dialysis, Risk Factors, Internal medicine, medicine, Humans, Aged, biology, business.industry, Continuous ambulatory peritoneal dialysis, Case-control study, General Medicine, Lipoprotein(a), Middle Aged, Surgery, Apolipoproteins, Phenotype, Nephrology, Case-Control Studies, biology.protein, Kidney Failure, Chronic, Female, Hemodialysis, business, Lipoprotein
Abstract

Numerous studies have investigated lipoprotein(a) (Lp(a)) plasma concentrations in patients with ESRD, a patient group with an enormous risk for atherosclerosis. The reported differences in Lp(a) between controls and patients vary from a decrease of 49% to an increase of more than 1,000%. However, data are not consistent, mostly because of problems with statistical analysis, and only limited data are available for patients treated by continuous ambulatory peritoneal dialysis (CAPD). To estimate the significance of Lp(a) in ESRD and to demonstrate the statistical pitfalls concerning Lp(a) in case-control studies, a large multicenter study including 702 patients treated by either hemodialysis (HD) (N = 534) or CAPD (N = 168) was conducted, and results were compared with results from 256 healthy controls. Both patient groups showed significantly elevated Lp(a) levels in comparison with controls: 23.4 +/- 25.0 mg/dL (P < 0.005; HD) and 34.6 +/- 38.4 mg/dL (P < 0.0001; CAPD) versus 18.4 +/- 22.8 mg/dL (controls). CAPD patients showed significantly higher Lp(a) values than did patients treated by HD (P < 0.001). The difference between the two treatment groups possibly reflects an overproduction of Lp(a) to compensate for protein losses in CAPD patients. Both treatment groups included significantly more patients with Lp(a) values greater than the 75th percentile (25.6 mg/dL) of the control group (33.9 and 41.7% for HD and CAPD, respectively; P < 0.005). The higher Lp(a) values in patients were not explained by differences in isoform frequencies and the increase in Lp(a) was apolipoprotein(a) type specific: only patients with high-molecular-weight apolipoprotein(a) isoforms showed a significant elevation in Lp(a) levels. The increased plasma concentrations of Lp(a) may contribute to the high risk for atherosclerosis in ESRD, especially in patients treated by CAPD. Finally, it is believed that small sample sizes are responsible for the diverging results in Lp(a) literature.

Published
1995

30. Coupled channel analysis of p annihilation into π0π0π0, π0ηη and π0π0η

Author

R. Ouared, H. Stöck, H. Kalinowsky, Herbert Koch, U. Thoma, Pàl Hidas, P. Giarritta, T. Case, B. Kalteyer, H. Matthäy, B. S. Zou, R. P. Haddock, L. Montanet, B. Kämmle, D. Urner, M. Lakata, N. Djaoshvili, Michael Kobel, K. Braune, S. U. Chung, S. Spanier, C. Kolo, R. Hackmann, P. Blüm, F. H. Heinsius, A. Cooper, C. Felix, J. Brose, D.V. Bugg, C. Holzhaussen, P. Illinger, R. Landua, Claude Amsler, O. Cramer, J. Kisiel, M. Suffert, R. Seibert, E. Schäfer, C.A. Baker, C. Völcker, S. v. Dombroski, C. A. Meyer, P. Schmidt, M. Schütrumpf, Marcel Kunze, W. Dünnweber, M. Herz, F. Walter, F. Ould-Saada, M. Benayoun, R. McCrady, Kenneth M. Crowe, A. Noble, Č. Zupančič, C. Regenfus, P. Birien, T. Degener, D. Walther, J. P. Merlo, U. Strohbusch, C. Straßburger, J. Lüdemann, K. Peters, C.J. Batty, S. Ravndal, U. Wiedner, Michael Doser, M. Tischhäuser, J. Zoll, R. Bossingham, N.P. Hessey, M. A. Faessler, G. Pinter, B. M. Barnett, Eberhard Klempt, T. Kiel, H. P. Dietz, C. N. Pinder, D. S. Armstrong, M. Englert, K. Beuchert, N. Winter, D. Jamnik, and D. Engelhardt

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Annihilation, Dalitz plot, Channel analysis
Abstract

We confirm the existence of the two IG(JPC) = 0+(0++) resonances f0(1370) and f0(1500) reported by us in earlier analyses. The analysis presented here couples the final states π0π0π0, π0π0η and π0ηη of pp annihilation at rest. It is based on a 3 × 3 K-matrix. We find masses and widths of M = (1390±30) MeV, Γ = (380±80) MeV; and M = (1500±10) MeV, Γ = (154 ± 30) MeV, respectively. The product branching ratios for the production and decay into π0π0 and ηη of the f0(1500) are (1.27 ± 0.33) · 10−3 and (0.60 ± 0.17) · 10−3, respectively.

Published
1995

31. High statistics study of ƒ0(1500)s decay into ηη

Author

J. Kisiel, H. Stöck, C. A. Meyer, P. Schmidt, D. Walther, A. Noble, D. Urner, P. Illinger, K.M. Crowe, G. Pinter, C.A. Baker, W. Dünnweber, R. McCrady, H. Kalinowsky, Eberhard Klempt, T. Kiel, H. P. Dietz, O. Cramer, M. Herz, C. N. Pinder, F. Walter, S. v. Dombrowski, D. S. Armstrong, E. Schäfer, C.J. Batty, N. Djaoshvili, U. Strohbusch, J. Lüdemann, C. Straßburger, L. Montanet, M. Merkel, Mark J. Burchell, M. Suffert, R. Seibert, R. Bossingham, C. Felix, Michael Kobel, R. Landua, F. Ould-Saada, M. A. Faessler, R.P. Haddock, B.M. Barnett, K. Peters, P. Giarritta, H. Matthaey, C. Regenfus, M. Lakata, Herbert Koch, Pàl Hidas, B. Kämmle, J. Brose, P. Birien, A. Cooper, T. Degener, Č. Zuppančič, M. Tischäuser, U. Wiedner, Michael Doser, J. Zoll, S. Ravndal, B. S. Zou, T. Case, Nigel Hessey, U. Thoma, C. Holzhaussen, C. Völcker, Marcel Kunze, K. Beuchert, D. Jamnik, D. Engelhardt, M. Englert, F.H. Heinsius, B. Kalteyer, S. Spanier, C. Kolo, R. Hackmann, K. Braune, S. U. Chung, S. Resag, J. P. Merlo, R. Ouared, K. Königsmann, Claude Amsler, P. Blüm, and D.V. Bugg

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Quality (physics), Partial wave analysis, Scalar (mathematics), Statistics, Dalitz plot, Resonance
Abstract

A partial wave analysis of the reaction p p →π o ηη has been performed, using a high quality, high statistics data set of 198,000 events. In addition to the ƒ 0 (1370), a second scalar resonance decaying into ηη, the ƒ 0 (1500), with mass m = (1505 ± 15) MeV and width Γ = (120 ± 30) MeV has to be introduced to describe the data.

Published
1995

32. η-decays into three pions

Author

J. Kisiel, W. Dünnweber, R. McCrady, C. Felix, Pàl Hidas, J. P. Merlo, P. Birien, K. Königsmann, K. Braune, Bernhard Schmid, K. Beuchert, N. Winter, D. Jamnik, D. Engelhardt, M. Suffert, R. Seibert, D. Urner, A. Cooper, J. Salk, H. Stöck, C.J. Batty, B. Kämmle, U. Thoma, Mark J. Burchell, F. H. Heinsius, C. Völcker, U. Wiedner, F. Ould-Saada, Claude Amsler, Michael Doser, P. Blüm, Herbert Koch, I. Augustin, M. A. Faessler, S. Ravndal, D.V. Bugg, R.P. Haddock, K. Peters, Marcel Kunze, D. Walther, C. Regenfus, R. Hackmann, T. Degener, M. Herz, G. Folger, Michael Kobel, U. Strohbusch, C. Straßburger, M. Lakata, C. A. Meyer, M. Englert, Č. Zupančič, J. Zoll, B. M. Barnett, J. Lüdemann, H. Kalinowsky, A. Noble, P. Illinger, O. Cramer, R. Landua, S. Spanier, E. Schäfer, T. Case, H. Matthäy, B.S. Zou, M. Tischhäuser, R. Bossingham, C.A. Baker, F. Walter, G. Pinter, Kenneth M. Crowe, J. Brose, L. Montanet, C. N. Pinder, S. v. Dombrowski, C. Kolo, D. S. Armstrong, M. Merkel, Eberhard Klempt, T. Kiel, H. P. Dietz, R. Glantz, Nigel Hessey, and P. Schmidt

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Crystallography, Chiral perturbation theory, Pion, Partial width, Mass spectrum, Dalitz plot
Abstract

The branching ratios Γ(η → 3π 0 ) Γ(η → π + π − π 0 ) = 1.44 ± 0.09 ± 0.10 and Γ(η → γγ) Γ(η → π + π − π 0 ) = 1.78 ± 0.10 ± 0.13 have been determined using the Crystal Barrel detector at LEAR. The latter ratio yields a partial width of Γ ( η → π + π − π 0 ) = 0.26 ± 0.03 keV using the known value for Γ ( η → γγ ). The η → π + π − π 0 ) Dalitz plot is compared to the predictions of chiral perturbation theory.

Published
1995

33. Production region of identical pions at 38 GeV/c pi--nuclei interactions with high-Ptparticles

Author

G. Pinter, S. Krasznovsky, T. Gemesy, A I Chklovskaia, L. L. Gabunia, Avto Kharchilava, V. N. Penev, L. S. Vertogradov, and L. Jenik

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Particle physics, Meson, High Energy Physics::Lattice, Nuclear Theory, Hadron, Elementary particle, Nuclear physics, Pair production, Pion, Pi, High Energy Physics::Experiment, Nuclear Experiment, Boson
Abstract

The correlation functions of pairs of identical pions, extracted from pi +or- meson production in pi -A (A=p,d,C,Cu,Pb) collisions at 38 GeV/c by high-Pt trigger, show an enhancement at small values of the pions' relative momenta. The radii R of the pion source were calculated using different parametrizations in pion interferometry. The values of R vary from 0.8 to 2 fm in different interactions with Pt>1 GeV/c. Significant changes of the pion source parameters for different Pt momenta cuts have not been observed.

Published
1995

34. Observation of radiative annihilation into a Φ meson

Author

C.A. Baker, C. Felix, F. Walter, C. A. Meyer, U. Thoma, A. Cooper, H. Stöck, F. H. Heinsius, Kenneth M. Crowe, M. Englert, A. Noble, J. Brose, M. A. Faessler, K. Beuchert, R.P. Haddock, B. Kämmle, K. Braune, C. Kolo, T. Case, H. Matthäy, N. Winter, D. Jamnik, D. Engelhardt, G. Pinter, R. Landua, B. M. Barnett, P. Schmidt, H. Kalinowsky, Mark J. Burchell, S. Spanier, L. Montanet, M. Suffert, R. Seibert, W. Dünnweber, O. Cramer, Claude Amsler, R. McCrady, R. Bossingham, F. Ould-Saada, Herbert Koch, E. Schäfer, C. Regenfus, Č. Zupančič, P. Birien, C. Völcker, Pàl Hidas, Marcel Kunze, M. Tischhäuser, T. Degener, M. Herz, J. P. Merlo, B. S. Zou, P. Illinger, J. Kisiel, K. Königsmann, P. Blüm, D. Urner, D.V. Bugg, R. Hackmann, M. Lakata, J. Zoll, Michael Kobel, Eberhard Klempt, T. Kiel, H. P. Dietz, I. Augustin, C. N. Pinder, K. Peters, S. v. Dombrowski, D. S. Armstrong, M. Merkel, U. Wiedner, Michael Doser, C.J. Batty, S. Ravndal, D. Walther, U. Strohbusch, C. Straßburger, J. Lüdemann, and Nigel Hessey

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Annihilation, Meson, Antiproton, Branching fraction, Radiative transfer, Analytical chemistry
Abstract

The annihilation p p → Φγ has been investigated with the Crystal Barrel detector at LEAR for antiprotons stopped in liquid hydrogen. The observed branching ratio BR ( p p → Φγ = (1.7 ± 0.4) · 10 −5 is almost two orders of magnitude higher than expected from the OZI-rule. As a by-product, the branching ratios BR ( p p → K L K S ) = (9.0 ± 0.6) · 10 −4 and BR ( p p → Φπ 0 ) = (5.5 ± 0.7) · 10 −4 have been measured.

Published
1995

35. High-statistics study of f0(1500) decay into π0π0

Author

C. Völcker, H. Kalinowsky, L. Montanet, B. Kämmle, Marcel Kunze, C. Kolo, Nigel Hessey, J. Kisiel, O. Cramer, C.A. Baker, R. Hackmann, C. A. Meyer, P. Blüm, Claude Amsler, M. Lakata, F. Walter, E. Schäfer, M. Suffert, R. Seibert, U. Wiedner, F. H. Heinsius, T. Case, H. Matthäy, Kenneth M. Crowe, R. Landua, Michael Doser, K. Beuchert, F. Ould-Saada, J. P. Merlo, P. Schmidt, J. Zoll, S. Spanier, K. Königsmann, A. Noble, H. Stöck, M. A. Faessler, W. Dünnweber, Herbert Koch, N. Winter, G. Pinter, T. Degener, M. Herz, B.M. Barnett, U. Thoma, K. Braune, S. U. Chung, D. Jamnik, R. Bossingham, Č. Zupančič, F. Loser, Mark J. Burchell, D. Engelhardt, D. Urner, C. Regenfus, C. Felix, K. Peters, Michael Kobel, P. Birien, Pàl Hidas, R. P. Haddock, M. Englert, C. N. Pinder, S. v. Dombrowski, D. S. Armstrong, M. Merkel, D. Walther, U. Strohbusch, C. Straßburger, J. Lüdemann, J. Brose, C.J. Batty, I. Augustin, S. Ravndal, Eberhard Klempt, T. Kiel, H. P. Dietz, J. Salk, and P. Illinger

Subjects
Data set, Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Angular distribution, Partial wave analysis, Scalar (mathematics), Dalitz plot, Resonance (particle physics)
Abstract

A partial-wave analysis of the reaction p p →π 0 π 0 π 0 has been performed using a high-quality high-statistics data set of 712 000 events. In addition to the f0(975) and f0(1300), the scalar resonance with mass m = (1500 ± 15) MeV and width Γ = (120 ± 25) MeV is necessary to describe the data.

Published
1995

36. ηη′ threshold enhancement in p̄p annihilations into π0ηη′ at rest

Author

R. Bossingham, M. Suffert, R. Seibert, C. N. Pinder, S. v. Dombrowski, D. S. Armstrong, F. Loser, Claude Amsler, U. Wiedner, M. Merkel, C.A. Baker, Michael Doser, F. H. Heinsius, I. Augustin, P. Schmidt, W. Dünnweber, J. P. Merlo, K. Peters, K. Königsmann, R. Hackmann, A. Cooper, C.J. Batty, F. Walter, Herbert Koch, Michael Kobel, P. Blüm, D.V. Bugg, M. Lakata, H. Kalinowsky, R. P. Haddock, Kenneth M. Crowe, B. M. Barnett, B. S. Zou, O. Cramer, M. A. Faessler, E. Schäfer, Eberhard Klempt, S. Ravndal, Mark J. Burchell, M. Englert, T. Kiel, H. P. Dietz, D. Walther, R. Landua, C. A. Meyer, C. Kolo, U. Strohbusch, Pàl Hidas, L. Montanet, B. Kämmle, Nigel Hessey, K. Beuchert, A. Noble, J. Lüdemann, N. Winter, P. Illinger, D. Jamnik, D. Engelhardt, J. Salk, J. Brose, K. Braune, S. U. Chung, T. Case, H. Matthäy, P. Birien, S. Spanier, C. Straβburger, G. Pinter, C. Völcker, Marcel Kunze, Č. Zupančič, D. Urner, C. Felix, J. Kisiel, F. Ould-Saada, T. Degener, M. Herz, and J. Zoll

Subjects
Physics, Rest (physics), Nuclear and High Energy Physics, Particle physics, Dalitz plot
Abstract

We report on the observation of an ηη′ threshold enhancement produced in pp annihilations at rest into π0ηη′, which we identify with the recently discovered ƒ 0 (1500) .

Published
1994

37. Hidden and open $$\bar ss$$ production in $$\bar pp$$ annihilation at restannihilation at rest

Author

A. H. Sanjari, D. Walther, K. Beuchert, R. Hackmann, J. Zoll, N. Winter, U. Strohbusch, P. Blüm, D. Jamnik, D. Engelhardt, C.A. Baker, F. Walter, Kenneth M. Crowe, Pàl Hidas, C. Kolo, J. Lüdemann, C. A. Meyer, D.V. Bugg, P. Birien, I. Augustin, S. Spanier, K. Peters, B. Schmid, G. Pinter, T. Case, B. Kämmle, James A. Bistirlich, T. Kiel, J. Salk, J. P. Merlo, K. Braune, B. M. Barnett, R. P. Haddock, C.J. Batty, L. Montanet, R. Bossingham, K. Königsmann, M. Englert, A. Noble, M. Suffert, F. H. Heinsius, U. Wiedner, R. Landua, C. Völcker, P. Schmidt, A. Cooper, Michael Doser, S. Ravndal, Mark J. Burchell, Marcel Kunze, W. Dünnweber, Claude Amsler, M. A. Faessler, Herbert Koch, H. Matthaey, Nigel Hessey, J. Brose, S. v. Dombrowski, D. S. Armstrong, M. Merkel, Eberhard Klempt, H. P. Dietz, Z. Jávorfi, F. Ould-Saada, C. Straßburger, G. Folger, C. Felix, Michael Kobel, D. Urner, J. Kisiel, H. Bossy, H. Kalinowsky, O. Cramer, E. Schäfer, Č. Zupančič, and P. Illinger

Subjects
Nuclear physics, Physics, Particle physics, Annihilation, OZI rule, High Energy Physics::Phenomenology, Dalitz plot, High Energy Physics::Experiment
Abstract

New branching ratios for\(\bar pp\) annihilation at rest into final states with a\(K\bar K\) pair or φ-meson are being measured with the Crystal Barrel detector at LEAR. The yield of φγ, relative to ωγ, appears to violate the OZI rule as strongly as φπ relative to ωπ.

Published
1994

38. High-statistics analysis of $$\bar pp \to \pi ^0 \pi ^0 \pi ^0 $$ at restat rest

Author

L. Montanet, U. Meyer-Berkhout, Mark J. Burchell, C.J. Batty, B. Schmid, G. Pinter, T. Case, R. Bossingham, A. H. Sanjari, K. Braune, J. Zoll, C. Kolo, M. Suffert, S. Ravndal, K. Beuchert, Claude Amsler, C.A. Baker, R. Hackmann, F. Walter, D. Walther, N. Winter, P. Birien, I. Augustin, Kenneth M. Crowe, M. A. Faessler, D. Jamnik, U. Strohbusch, F. H. Heinsius, C. Völcker, K. Peters, D. Engelhardt, Pàl Hidas, H. Matthaey, H. Kalinowsky, C. A. Meyer, James A. Bistirlich, P. Schmidt, O. Cramer, J. Lüdemann, R. P. Haddock, W. Dünnweber, A. Noble, E. Schäfer, J. Salk, Marcel Kunze, U. Wiedner, R. Landua, Herbert Koch, Michael Doser, S. Spanier, B. Kämmle, P. Illinger, A. Cooper, M. Englert, B. M. Barnett, Nigel Hessey, J. P. Merlo, K. Königsmann, P. Blüm, D.V. Bugg, T. Kiel, G. Folger, Michael Kobel, Č. Zupančič, J. Kisiel, C. Felix, H. Bossy, Z. Jávorfi, C. Straßburger, J. Brose, Eberhard Klempt, H. P. Dietz, D. Urner, S. v. Dombrowski, and M. Merkel

Subjects
Nuclear physics, Rest (physics), Physics, Particle physics, Annihilation, Amplitude, Pi, Dalitz plot, Invariant (mathematics), Nuclear Experiment, Resonance (particle physics), Bar (unit)
Abstract

Antiproton-proton annihilation at rest into 3π0 is analysed based on a data sample of about 500 000 high-quality 3π0 events. In this high-statistics Dalitz plot two structures in the region of π0π0 invariant masses of about 1500 MeV show up, a small band and a blob at higher masses. In a first attempt to describe the data two different models are used to parametrize the dynamical amplitudes leading to the same conclusion: the data require a 0+ + and also a 2+ + resonance in the 1500 MeV region.

Published
1994

39. Test of chiral perturbation theory in η decays

Author

R. Bossingham, C. A. Meyer, J. Lüdemann, R. P. Haddock, A. Noble, A. Cooper, M. A. Faessler, A. H. Sanjari, T. Case, B. Schmid, H. Matthäy, G. Pinter, K. Braune, J. Zoll, C. Felix, B. M. Barnett, P. Schmidt, D. Walther, Eberhard Klempt, G. Folger, L. Montanet, W. Dünnweber, James A. Bistirlich, H. P. Dietz, Michael Kobel, Pàl Hidas, C.A. Baker, D. Umer, Claude Amsler, M. Suffert, I. Augustin, F. Walter, R. Hackmann, S. v. Dombrowski, D. S. Armstrong, P. Birien, Kenneth M. Crowe, M. Merkel, H. Kalinowski, Č. Zupančič, Z. Jávorfi, B. Kämmle, K. Beuchert, C. Kolo, F. Ould-Saada, C. Straßburger, D. Jamnik, P. Illinger, N. P. Hessey, D. Engelhardt, J. Brose, F. H. Heinsius, C. Völcker, U. Wiedner, Michael Doser, Mark J. Burchell, J. P. Merlo, M. Englert, Marcel Kunze, K. Königsmann, T. Kiel, J. Kisiel, H. Bossy, S. Ravndal, P. Blüm, D.V. Bugg, J. Salk, S. Waßmer, C.J. Batty, H. Koch, U. Strohbusch, R. Landua, E. Schäfer, and Krisztian Peters

Subjects
Quantum chromodynamics, Crystal, Nuclear physics, Physics, Particle physics, Chiral perturbation theory, Pion, Partial width, Order (group theory), Charged particle
Abstract

The decay of the η-meson into three pions plays an important role as a test of low-energy QCD calculations in the framework of chiral perturbation theory. Previous experiments show results that are inconclusive or even contradictory. The Crystal Barrel experiment at LEAR has determined the braching ratiosΓ(η→3π0)/Γ(η→π+π−π0)=1.47±0.09±0.15 andΓ(η→γγ)/Γ(η→π+π−π0)=1.88±0.10±0.17 using its unique features to detect charged particles as well as neutral particles. The value for the first ratio agrees nicely with the theoretical predictions and solves previous experimental uncertainties. The second value, which yields a partial width ofΓ(η→π+π−π0)=(0.24±0.03) keV, shows that the same next-to-leading order chiral perturbation theory calculations still have some problems.

Published
1994

40. $$\bar pp$$ Annihilation at rest into K L 0 K S 0 π0π0Annihilation at rest into K L 0 K S 0 π0π0

Author

Faessler, D. Walther, G. Folger, Michael Kobel, E. Schaefer, R. Hackmann, U. Strohbusch, P. Schmidt, W. Dünnweber, J. P. Merlo, K. Braune, P. Birien, H. Kalinowsky, Eberhard Klempt, Mark J. Burchell, Michael Doser, H. P. Dietz, J. Brose, I. Augustin, Farid Ould-Saada, R. Bossingham, B. Schmid, C.J. Batty, C. Kolo, G. Pinter, U. Wiedner, M. Suffert, K. Peters, F. H. Heinsius, C. N. Pinder, R. Landua, S. Spanier, S. von Dombrowski, D. S. Armstrong, B. M. Barnett, P. Blüm, Pàl Hidas, M. Englert, M. Merkel, O. Cramer, S. Ravndal, Claude Amsler, C.A. Baker, D.V. Bugg, Herbert Koch, L. Montanet, B. Kaemmle, A. H. Sanjari, J. Zoll, F. Walter, C. A. Meyer, K. Beuchert, T. Case, Kenneth M. Crowe, Marcel Kunze, A. Noble, N. Winter, D. Jamnik, D. Engelhardt, P. Illinger, A. Cooper, Kay Konigsmann, R.P. Haddock, H. Matthaey, C. Voelcker, J. Salk, Nigel Hessey, J. Luedemann, T. Kiel, C. Strassburger, Z. Jávorfi, J. Kisiel, Č. Zupančič, H. Bossy, D. Urner, and C. Felix

Subjects
Physics, Rest (physics), Nuclear physics, Particle physics, Annihilation, Hadron spectroscopy, Partial wave analysis
Published
1994

41. Antiproton annihilation at rest in liquid deuterium into π−π0π0pS

Author

Pàl Hidas, M. Suffert, C. Kolo, Nigel Hessey, J. Brose, T. Kiel, B. Schmid, M. A. Faessler, R. Bossingham, G. Pinter, U. Meyer-Berkhout, R. Hackmann, U. Wiedner, H. Matthaey, Eberhard Klempt, Michael Doser, R. Landua, C.J. Batty, P. Schmidt, P. Illinger, A. H. Sanjari, J. Zoll, H. P. Dietz, C.A. Baker, L. Montanet, J. P. Merlo, S. v. Dombrowski, F. Walter, K. Königsmann, W. Dünnweber, S. Ravndal, J. Kisiel, C. A. Meyer, D. Walther, Kenneth M. Crowe, M. Merkel, I. Augustin, A. Cooper, H. Bossy, U. Strohbusch, K. Peters, B. Kämmle, Mark J. Burchell, R. P. Haddock, K. Braune, S. Spanier, A. Noble, J. Lüdemann, H. Kalinowsky, Herbert Koch, P. Birien, D. Urner, F. H. Heinsius, C. Völcker, E. Schäfer, Z. Jávorfi, C. Straßburger, Marcel Kunze, Claude Amsler, James A. Bistirlich, T. Case, G. Folger, Michael Kobel, P. Blüm, C. Felix, D.V. Bugg, Č. Zupančič, M. Englert, B. M. Barnett, K. Beuchert, N. Winter, D. Jamnik, and D. Engelhardt

Subjects
Nuclear physics, Physics, Crystal, Annihilation, Deuterium, Antiproton, Partial wave analysis, Resonance, Dalitz plot, Atomic physics, Parametrization
Abstract

With the Crystal Barrel detector, the final state π−π0π0pS at rest in liquid deuterium was measured for the first time. A preliminary partial-wave analysis was performed, which required two interesting features: besides the ρ(770), a second pole was needed in the ππP-wave and a narrow resonance in the ππS-wave, slightly above 1500 MeV/c2. With the same parametrization a high-statistics π+π−π0 data set could also be well described.

Published
1994

42. Observation of a new IG(JPC)=1−(0++) resonance at 1450 MeV

Author

P. Schmidt, W. Dünnweber, C. Felix, U. Wiedner, Michael Doser, B. S. Zou, Eberhard Klempt, D. Urner, C. Kolo, L. Montanet, B. Kämmle, F. Loser, I. Augustin, T. Kiel, H. P. Dietz, C.J. Batty, Pàl Hidas, K. Peters, J. P. Merlo, R. Hackmann, J. Kisiel, C.A. Baker, A. V. Sarantsev, F. H. Heinsius, S. Ravndal, Herbert Koch, V. V. Anisovich, M. Suffert, D. Walther, J. Zoll, F. Walter, U. Strohbusch, G. Pinter, K. Königsman, Mark J. Burchell, Kenneth M. Crowe, Michael Kobel, J. Lüdemann, A. Cooper, J. Brose, S. von Dombrowski, B. M. Barnett, F. Ould-Saada, C. A. Meyer, Č. Zupančič, S. Spanier, P. Blüm, H. Kalinowsky, C. N. Pinder, A. Noble, R. Landua, D. S. Armstrong, T. Degener, M. Herz, D.V. Bugg, M. Merkel, P. Illinger, E. Schäfer, J. Salk, Nigel Hessey, C. Völcker, Marcel Kunze, C. Straβburger, R. Bossingham, Claude Amsler, K. Braune, S. U. Chung, M. A. Faessler, T. Case, H. Matthäy, M. Englert, P. Birien, R. P. Haddock, K. Beuchert, N. Winter, D. Jamnik, and D. Engelhardt

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Annihilation, Partial wave analysis, Resonance, Dalitz plot, Elementary particle, Quantum number
Abstract

A new IG=1− JPC=0++πη resonance is observed in pp annihilation at rest into π0π0η. It has a mass M=(1450±40)MeV and a width Γ=(270±40)MeV.

Published
1994

43. Search for a new light gauge boson in decays of π0 and η

Author

F. H. Heinsius, A. Cooper, G. Pinter, Č. Zupančič, B. S. Zou, L. Montanet, S. von Dombrowski, D. Urner, C. Felix, M. Suffert, Pàl Hidas, T. Case, B. Kämmle, H. Matthäy, Z. Jávorfi, P. Blüm, F. Ould-Saada, Claude Amsler, D.V. Bugg, J. Salk, R. Hackmann, T. Degener, C. A. Mever, D. Walther, R. Bossingham, J. Kisiel, Mark J. Burchell, N. Winter, U. Strohbusch, P. Birien, C. Kolo, J. Lüdemann, Michael Kobel, K. Beuchert, C.J. Batty, D. Jamnik, D. Engelhardt, B. M. Barnett, S. Ravndal, C.A. Baker, K. Braune, H. Kalinowsky, F. Walter, J. P. Merlo, M. Englert, K. Königsmann, R. Landua, Kenneth M. Crowe, E. Schäfer, J. Brose, Eberhard Klempt, T. Kiel, H. P. Dietz, C. N. Pinder, D. S. Armstrong, A. Noble, M. Merkel, J. Zoll, Herbert Koch, P. Illinger, I. Augustin, P. Schmidt, K. Peters, W. Dünnweber, A. H. Sanjari, M. A. Faessler, R.P. Haddock, Bernhard Schmid, F. Loser, U. Wiedner, Michael Doser, C. Völcker, Marcel Kunze, C. Straβburger, S. Spanier, N. P. Hessey, Heyd, Yvette, Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), and CRYSTAL BARREL

Subjects
Physics, Nuclear and High Energy Physics, Range (particle radiation), Gauge boson, Particle physics, Photon, [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], 010308 nuclear & particles physics, Branching fraction, Elementary particle, 01 natural sciences, Upper and lower bounds, Nuclear physics, Particle decay, Photon emission, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], 010306 general physics, Particle Physics - Experiment
Abstract

We have searched for new light gauge bosons produced in π 0 and η decays by studying the kinematically well-constrained reactions p p→π 0 π 0 π 0 and p p→π 0 π 0 η , where one π 0 or the η decays through the emission of a single photon recoiling against a missing state X (where X is a long-lived weakly interacting particle or X →ν ν ). No signal has been observed and branching ratio upper limits of 6 × 10 −5 at 90% C.L. have been obtained for masses of the gauge boson lying between ∼65 MeV and 125 MeV ( π 0 decay), and 6 × 10 −5 at 90% C.L. for X masses between ∼200 MeV and 525 MeV (η decay). The π 0 -decay limit represents a factor of 4 to 8 improvement when compared to the existing limit, whereas the η decay limit has been measured for the first time, thereby extending the m x range from 130 MeV up to 525 MeV.

Published
1994

44. Observation of two JPC=0++ isoscalar resonances at 1365 and 1520 MeV

Author

Nigel Hessey, P. Blüm, C.A. Baker, A. V. Sarantsev, G. Folger, D.V. Bugg, R. Landua, K.M. Crowe, Michael Kobel, B. S. Zou, Eberhard Klempt, H. P. Dietz, G. Pinter, Pàl Hidas, P. Schmidt, F. Walter, J. Lüdemann, H. Koch, W. Dünnweber, J. P. Merlo, K. Königsmann, Krisztian Peters, B. M. Barnett, P. Illinger, M. Suffert, H. Kalinowsky, H. Matthäy, R. Bossingham, U. Wiedner, S. Spanier, U. Strohbusch, A. Noble, A. Cooper, J. Brose, J. Kisiel, Mark J. Burchell, E. Schäfer, Michael Doser, V. V. Anisovich, C. Kolo, L. Montanet, B. Kämmle, C. N. Pinder, T. Kiel, I. Augustin, K. Braune, D. Walther, D. S. Armstrong, Z. Jávorfi, C.J. Batty, C. Felix, C. Straßburger, M. Merkel, B. Schmid, M. A. Faessler, S. Ravndal, T. Degener, J. Salk, F. H. Heinsius, C. Völcker, A. H. Sanjari, J. Zoll, Marcel Kunze, T. Case, R. Hackmann, P. Birien, K. Beuchert, C. A. Meyer, N. Winter, D. Jamnik, D. Engelhardt, M. Englert, and R. P. Haddock

Subjects
Nuclear physics, Elastic scattering, Physics, Nuclear and High Energy Physics, Amplitude, Isoscalar, Resonance, Dalitz plot, Particle Data Group
Abstract

From a simultaneous analysis of data on pp → π0π0π0 and pp → ηηπ0 at rest, two I = 0, JPC = 0++ resonances are identified above 1 GeV. The first has mass M = 1365−55+20 MeV and width г = 268 ± 70 MeV, close to the ƒ0(1400) of the Particle Data Group. The second has M = 1520 ± 25 MeV, г = 148−25+20 MeV.

Published
1994

45. Protonium annihilation into KL0KL0π0 and KL0KS0η

Author

F. H. Heinsius, C. Völcker, Nigel Hessey, J. P. Merlo, R. Bossingham, C. N. Pinder, K. Königsmann, Pàl Hidas, Marcel Kunze, M. Suffert, P. Illinger, K. Braune, R. Hackmann, K. Beuchert, D. S. Armstrong, L. Montanet, N. Winter, T. Kiel, B. Kämmle, D. Jamnik, D. Engelhardt, C. Felix, D. Urner, H. Kalinowsky, M. Merkel, D. Walther, A. Cooper, S. von Dombrowski, P. Birien, C.A. Baker, M. Englert, E. Schäfer, S. Spanier, Eberhard Klempt, H. P. Dietz, F. Walter, P. Blüm, R. Glantz, Kenneth M. Crowe, Č. Zupančič, D.V. Bugg, Claude Amsler, J. Kisiel, U. Strohbusch, T. Case, H. Matthäy, G. Folger, Herbert Koch, Michael Kobel, C. Kolo, J. Brose, Z. Jávorfi, J. Lüdemann, F. Ould-Saada, C. Straßburger, A. H. Sanjari, J. Zoll, B. M. Barnett, T. Degener, G. Pinter, R. Landua, I. Augustin, K. Peters, C.J. Batty, C. A. Meyer, S. Ravndal, A. Noble, U. Wiedner, J. Salk, Michael Doser, Mark J. Burchell, B. S. Zou, M. A. Faessler, R.P. Haddock, P. Schmidt, W. Dünnweber, and Bernhard Schmid

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Annihilation, Amplitude, 010308 nuclear & particles physics, Protonium, 0103 physical sciences, Resonance, Elementary particle, 010306 general physics, 01 natural sciences
Abstract

The annihilation of pp at rest into KL0KS0π0 and KL0KS0η was investigated with the Crystal Barrel detector at LEAR. These final states with negative C-parity are dominated by φ and K0∗ resonances. The ratios of the branching ratios are B(pp→φπ0)B(pp→φη)=8.3±2.1 and B(pp→K0K0∗+K0K0∗→KL0KS0π0)B(pp→φπ0→KL0KS0π0)= 2.04±0.21.

Published
1993

46. Antiproton-proton annihilation at rest into ωπ0π0

Author

L. Montanet, Herbert Koch, R. Hackmann, P. Schmidt, I. Augustin, F. H. Heinsius, D. Walther, C. Völcker, Mark J. Burchell, K. Peters, C. A. Meyer, U. Strohbusch, S. v. Dombrowski, D. S. Armstrong, James A. Bistirlich, Marcel Kunze, W. Dünnweber, A. Cooper, M. Merkel, Z. Jávorfi, J. Lüdemann, M. Suffert, A. Noble, C. Felix, C. Straßburger, J. Brose, T. Kiel, B. Schmid, Eberhard Klempt, G. Folger, P. Illinger, G. Pinter, H. P. Dietz, Michael Kobel, Michael Doser, A. H. Sanjari, B. Kämmle, J. Zoll, B. M. Barnett, Pàl Hidas, S. M. Spanier, J. Salk, E. Schäfer, C.J. Batty, Farid Ould-Saada, J. Kisiel, H. Bossy, M. A. Faessler, K. Beuchert, S. Ravndal, R.P. Haddock, N. Winter, D. Urner, D. Jamnik, H. Matthaey, D. Engelhardt, M. Englert, Nigel Hessey, Č. Zupančič, R. Bossingham, U. Wiedner, K. Braune, R. Landua, S. U. Chung, T. Case, H. Kalinowsky, C.A. Baker, J. P. Merlo, K. Königsmann, F. Walter, Kenneth M. Crowe, P. Blüm, Claude Amsler, D.V. Bugg, C. Kolo, and P. Birien

Subjects
Rest (physics), Nuclear physics, Physics, Nuclear and High Energy Physics, Annihilation, Proton, Antiproton
Published
1993

47. Radiative protonium annihilation into γγ, γπ0, γη, γω and γη′

Author

B. M. Barnett, R. Landua, L. Montanet, A. Cooper, M. Suffert, H. Kalinowsky, T. Case, J. Kisiel, J. Brose, H. Bossy, E. Schäfer, P. Blüm, Nigel Hessey, B. Kämmle, C. Kolo, S. v. Dombrowski, D. S. Armstrong, Z. Jávorfi, G. Pinter, M. Merkel, D.V. Bugg, F. Ould-Saada, C. Straßburger, P. Birien, C.A. Baker, Eberhard Klempt, H. P. Dietz, Claude Amsler, J. P. Merlo, S. Spanier, K. Königsmann, F. Walter, D. Urner, T. Kiel, P. Illinger, D. Walther, Kenneth M. Crowe, R. Bossingham, F. H. Heinsius, U. Strohbusch, C. Völcker, Herbert Koch, G. Folger, Marcel Kunze, Michael Kobel, Č. Zupančič, C. Felix, J. Lüdemann, K. Braune, S. U. Chung, C. A. Meyer, S. Waßmer, A. Noble, U. Wiedner, Michael Doser, I. Augustin, K. Peters, C.J. Batty, S. Ravndal, A. H. Sanjari, J. Zoll, James A. Bistirlich, P. Schmidt, W. Dünnweber, M. A. Faessler, R.P. Haddock, H. Matthaey, Bernhard Schmid, M. Englert, J. Salk, K. Beuchert, R. Hackmann, N. Winter, D. Jamnik, D. Engelhardt, Pàl Hidas, and Mark J. Burchell

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Annihilation, 010308 nuclear & particles physics, Antiproton, Branching fraction, 0103 physical sciences, Radiative transfer, 010306 general physics, 01 natural sciences
Abstract

Radiative p p annihilation at rest into γγ , γπ 0 , γη , γω and γη′ has been measured with the Crystal Barrel detector at LEAR for antiprotons stopped in liquid hydrogen. The branching ratios are B γπ 0 =(44±4)×10 −6 , B γη =(9.3±1.4)×10 −6 and B γω =(68±18)×10 −6 , respectively. For B γγ and B γη ′ we find new upper limits of 0.63×10 −6 and 12×10 −6 (95% CL), respectively.

Published
1993

48. New states as observed by the Crystal Barrel experiment

Author

I. Augustin, C. Amsler, C.A. Baker, B.M. Barnett, C.J. Batty, K. Beuchert, P. Birien, J. Bistirlich, P. Blüm, R. Bossingham, H. Bossy, K. Braune, J. Brose, D.V. Bugg, M. Burchell, T. Case, S.V. Chung, A. Cooper, K.M. Crowe, H.P. Dietz, S.V. Dombrowski, M. Doser, W. Dünnweber, D. Engelhardt, M. Englert, M.A. Faessler, C. Felix, G. Folger, R. Hackmann, R.P. Haddock, F.H. Heinsius, N.P. Hessey, P. Hidas, P. Illinger, D. Jamnik, Z. Jávorfi, H. Kalinowsky, B. Kämmle, T. Kiel, J. Kisiel, E. Klempt, M. Kobel, H. Koch, C. Kolo, K. Königsmann, M. Kunze, R. Landua, J. Lüdemann, H. Matthaey, M. Merkel, J.P. Merlo, C.A. Meyer, U. Meyer-Berkhout, L. Montanet, A. Noble, K. Peters, G. Pinter, S. Ravndal, A.H. Sanjari, E. Schäfer, B. Schmid, P. Schmidt, S. Spanier, C. Straßburger, U. Strohbusch, M. Suffert, D. Urner, C. Völcker, F. Walter, D. Walther, U. Wiedner, N. Winter, J. Zoll, and Č. Zupančič

Subjects
Nuclear physics, Crystal, Physics, Nuclear and High Energy Physics, Barrel, Annihilation, Protonium, Branching fraction, Isoscalar, Resonance, State (functional analysis), Atomic physics
Abstract

The Crystal Barrel Detector has been in operation since October 1989. Results on the analysis of the annihilation of protonium at rest into three pseudoscalars is presented. The π 0 π 0 π 0 final state confirms the existence of ƒ 2 (1520)→π 0 π 0 . In the ηη system of the π 0 ηη final state an isoscalar J PC = 0 ++ resonance with a mass of 1560 MeV/c 2 and a width of 245 MeV/c 2 is observed. The identification with ƒ 0 (1590) is doubtful since the ηη' decay is not observed with the corresponding strength. Our analysis yields an upper limit for the relative branching ratio BR(ƒ 0 (1560)→ηη') BR(ƒ 0 (1560)→ηη) .

Published
1993

49. Final states with strangeness from Crystal Barrel and Asterix

Author

K. Braune, C. Amsler, I. Augustin, C.A. Bakery, B.M. Barnett, C.J. Batty, K. Beuchert, P. Binen, J. Bistirlich, P. Blüm, R. Bossingham, H. Bossy, J. Brose, D.V. Bugg, M. Burchell, T. Case, S.U. Chung, A. Cooper, K.M. Crowe, H.P. Dietz, S.v. Dombrowski, M. Doser, W. Dünnweber, D. Engelhardt, M. Englert, M.A. Faessler, C. Felix, G. Folger, R. Hackmann, R.P. Haddock, F.H. Heinsius, N.P. Hessey, P. Hidas, P. Illinger, D. Jamnik, Z. Jávorfi, H. Kalinowsky, B. Kämmle, T. Kiel, J. Kisiel, E. Klempt, M. Kobel, H. Koch, C. Kolo, K. Königsmann, M. Kunze, R. Landua, J. Lüdemann, H. Matthaey, M. Merkel, J.P. Merlo, C.A. Meyer, U. Meyer-Berkhout, L. Montanet, A. Noble, K. Peters, G. Pinter, S. Ravndal, A.H. Sanjari, E. Schäfer, B. Schmid, P. Schmidt, S. Spanier, C. Straßburger, U. Strohbusch, M. Suffert, D. Urner, C. Völcker, F. Walter, D. Walther, U. Wiedner, N. Winter, J. Zoll, and Č. Zupančič

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Mass spectrum, Dalitz plot, ASTERIX, Strangeness
Abstract

We discuss φ production in p p annihilation at rest from the Asterix and Crystal Barrel experiments and compare the branching ratios to similar final states without strangeness. The ωπ 0 φπ 0 production ratio is unexpectedly low. In the search for new states, the φπ0 mass spectrum shows no evidence for a resonance in the 1450 MeV/c2 mass range but the K☆K0π0 Dalitz plot shows interesting structure.

Published
1993

50. Antiproton-proton annihilation at rest into two mesons

Author

C. A. Meyer, A. Noble, U. Meyer-Berkhout, B. Schmid, R. P. Haddock, T. Case, P. Schmidt, A. H. Sanjari, G. Pinter, D. Walther, K. Beuchert, J. Zoll, N. Winter, D. Jamnik, D. Engelhardt, W. Dünnweber, Claude Amsler, J. Brose, B. M. Barnett, M. Englert, C.A. Baker, U. Strohbusch, D. Urner, R. Hackmann, M. Suffert, J. Lüdemann, A. Cooper, F. Walter, Herbert Koch, P. Blüm, H. Kalinowsky, K. Peters, C.J. Batty, J. Kisiel, Mark J. Burchell, R. Landua, M. A. Faessler, D.V. Bugg, H. Bossy, E. Schäfer, James A. Bistirlich, Pàl Hidas, U. Wiedner, Kenneth M. Crowe, Michael Doser, S. v. Dombrowski, G. Folger, I. Augustin, Michael Kobel, K. Braune, S. U. Chung, M. Merkel, S. Ravndal, J. P. Merlo, L. Montanet, S. Spanier, B. Kämmle, K. Königsmann, Nigel Hessey, P. Illinger, C. Kolo, P. Birien, F. H. Heinsius, Eberhard Klempt, C. Völcker, H. P. Dietz, Marcel Kunze, T. Kiel, H. Matthaey, R. Bossingham, Z. Jávorfi, C. Straßburger, Č. Zupančič, and C. Felix

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Meson, Antiproton, Radiative transfer, High Energy Physics::Experiment, Nuclear Experiment, Liquid hydrogen
Abstract

Branching ratios for antiproton-proton annihilations at rest into two mesons are given. The data were obtained at LEAR by stopping antiprotons in a liquid hydrogen target. Both charged and neutral annihilation products were detected in the Crystal Barrel detector. Representative data are presented, and their bearing on the general picture of annihilation dynamics is discussed. In addition, preliminary branching ratios for two-body radiative annihilations are given.

Published
1993

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