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1. Regionalisation of rainfall depth–duration–frequency curves with different data types in Germany

Author

B. Shehu, W. Willems, H. Stockel, L.-B. Thiele, and U. Haberlandt

Subjects
Technology, Environmental technology. Sanitary engineering, TD1-1066, Geography. Anthropology. Recreation, Environmental sciences, GE1-350
Abstract

Rainfall depth–duration–frequency (DDF) curves are required for the design of several water systems and protection works. For the reliable estimation of such curves, long and dense observation networks are necessary, which in practice is seldom the case. Usually observations with different accuracy, temporal resolution and density are present. In this study, we investigate the integration of different observation datasets under different methods for the local and regional estimation of DDF curves in Germany. For this purpose, two competitive DDF procedures for local estimation (Koutsoyiannis et al., 1998; Fischer and Schumann, 2018) and two for regional estimation (kriging theory vs. index based) are implemented and compared. Available station data from the German Weather Service (DWD) for Germany are employed, which includes 5000 daily stations with more than 10 years available, 1261 high-resolution (1 min) recordings with an observation period between 10 and 20 years, and finally 133 high-resolution (1 min) recordings with 60–70 years of observations. The performance of the selected approaches is evaluated by cross-validation, where the local DDFs from the long sub-hourly time series are considered the true reference. The results reveal that the best approach for the estimation of the DDF curves in Germany is by first deriving the local extreme value statistics based on Koutsoyiannis et al.'s (1998) framework and later using the kriging regionalisation of long sub-hourly time series with the short sub-hourly time series acting as an external drift. The integration of the daily stations proved to be useful only for DDF values of a low return period (T[a] < 10 years) but does not introduce any improvement for higher return periods (T[a] ≥ 10 years).

Published
2023
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2. Branching ratios for p annihilation at rest into two-body final states

Author

F. H. Heinsius, P. Blüm, D.V. Bugg, U. Strohbusch, C. Straßburger, K. Wittmack, R. Ouared, U. Kurilla, D. Walther, D. Jamnik, J.S. Suh, D. Engelhardt, A. Abele, C.J. Batty, M. A. Faessler, C. Völcker, R.P. Haddock, M. Herz, P. Giarritta, Herbert Koch, Claude Amsler, J. Adomeit, I. Uman, Michael Doser, Marcel Kunze, H. Stöck, A. Herbstrith, C. Holtzhaußen, C. A. Meyer, K. Peters, W. Dünnweber, R. McCrady, M. Lakata, C. Regenfus, J. Kisiel, U. Wiedner, M. Suffert, T. Case, H. Matthäy, B. Pick, P. Kammel, K. Braune, M. Heinzelmann, C.A. Baker, S. Wallis-Plachner, L. Montanet, B.M. Barnett, M. Benayoun, Kenneth M. Crowe, B.S. Zou, H. Kalinowsky, J. Meier, S. Spanier, U. Thoma, C. Hodd, S. Bischoff, Eberhard Klempt, Pàl Hidas, T. Degener, W. Roethel, M. Tischhäuser, M. Ratajczak, N.P. Hessey, and R. Landua

Subjects
Physics, Nuclear and High Energy Physics, Annihilation, Hydrogen, chemistry, Branching fraction, Analytical chemistry, chemistry.chemical_element, Atomic physics, Branching (polymer chemistry), Particle Physics - Experiment
Abstract

Measurements of two-body branching ratios for p p annihilations at rest in liquid and gaseous (12 ρ STP ) hydrogen are reported. Channels studied are p p →π 0 π 0 ,π 0 η , K 0 S K 0 L , K + K − . The branching ratio for the π 0 π 0 channel in liquid H 2 is measured to be ( 6.14±0.40)×10 −4 . The results are compared with those from other experiments. The fraction of P-state annihilation for a range of target densities from 0.002 ρ STP to liquid H 2 is determined. Values obtained include 0.11±0.02 in liquid H 2 and 0.48±0.04 in 12 ρ STP H 2 gas.

Published
2001
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3. The ρ-mass, width and line shape in annihilation at rest into π+π−π0

Author

H. Stöck, W. Roethel, P. Blüm, Herbert Koch, F. H. Heinsius, D.V. Bugg, M. Heinzelmann, U. Strohbusch, C. Straßburger, K. Braune, S. Wallis-Plachner, S. Bischoff, A. Ehmanns, C. Holtzhaußen, A. Herbstrith, O. Cramer, D. Walther, A. Berdoz, K. Wittmack, C.J. Batty, R. Ouared, Claude Amsler, Eberhard Klempt, Michael Doser, V. Crede, W. Dünnweber, U. Kurilla, J. Adomeit, K. Peters, T. Case, H. Matthäy, J. Kisiel, U. Wiedner, I. Uman, C. A. Meyer, C.A. Baker, P. Kammel, Stefan M Spanier, M. Lakata, Kenneth M. Crowe, B.M. Barnett, U. Thoma, C. Hodd, B. Pick, M. A. Faessler, R.P. Haddock, D. Jamnik, T. Degener, B.S. Zou, D. Engelhardt, C. Regenfus, M. Herz, H. Kalinowsky, J. Meier, Pàl Hidas, P. Giarritta, R. McCrady, J.S. Suh, R. Landua, M. Suffert, C. Völcker, A. V. Anisovich, Marcel Kunze, M. Ratajczak, M. Tischhäuser, N.P. Hessey, and A. Abele

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Nuclear magnetic resonance, Annihilation, Hadron physics, Pi, Line (formation), Bar (unit)
Abstract

The rho mass, width and line shape in p(over)-bar-p annihilation at rest into pi(+)pi(-)pi(0)

Published
1999
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4. annihilation at rest into π+π−π−pspectator

Author

C.J. Batty, Michael Doser, H. Stöck, I. Uman, K. Peters, D. Walther, U. Strohbusch, C. Holtzhaußen, U. Kurilla, P. Kammel, O. Cramer, T. Case, H. Matthäy, P. Giarritta, Pàl Hidas, U. Wiedner, N. Djaoshvili, R. Landua, K. Wittmack, S. M. Spanier, R. Ouared, S. Bischoff, C. Pietra, R.P. Haddock, A. Herbstrith, B. Pick, M. Ratajczak, P. Schmidt, U. Thoma, C. Hodd, Claude Amsler, M. Suffert, R. Seibert, J.S. Suh, W. Dünnweber, R. McCrady, B.S. Zou, F. H. Heinsius, C. Völcker, M. Tischhäuser, Faessler, Marcel Kunze, H. Kalinowsky, K. Braune, J. Meier, C.A. Baker, M. Lakata, Nigel Hessey, M. Benayoun, Kenneth M. Crowe, J. Kisiel, C. Straßburger, M. Heinzelmann, T. Degener, M. Herz, S. Wallis-Plachner, B. M. Barnett, C. A. Meyer, Herbert Koch, A. Berdoz, Eberhard Klempt, C. N. Pinder, W. Roethel, D. Jamnik, D. Engelhardt, A. Abele, C. Regenfus, J. Adomeit, P. Blüm, and D.V. Bugg

Subjects
Rest (physics), Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Partial wave analysis, Pi
Published
1999
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5. Evidence for a πη-P-wave in -annihilations at rest into π0π0η

Author

H. Matthäy, H. Stöck, C. A. Meyer, M. Heinzelmann, U. Kurilla, S. Wallis-Plachner, V. Crede, C. N. Pinder, S. v. Dombrowski, C. Holtzhaußen, K.M. Crowe, J.S. Suh, Michael Doser, B. Kämmle, M. Tischhäuser, Pàl Hidas, A. Herbstrith, F. Ould-Saada, S. Resag, Herbert Koch, R. Ouared, K. Peters, O. Cramer, C. Völcker, K. Hüttmann, R. Landua, K. Wittmack, B. Pick, C.J. Batty, M. Lakata, F.H. Heinsius, K. Beuchert, N.P. Hessey, C. Pietra, W. Roethel, I. Uman, D. Jamnik, D. Engelhardt, M. Herz, A. Abele, Marcel Kunze, K. Braune, A. Berdoz, T. Degener, C. Regenfus, J. Kisiel, P. Kammel, U. Strohbusch, C. Straßburger, U. Wiedner, B.M. Barnett, T. Case, Claude Amsler, P. Giarritta, A. Ehmanns, M. Ratajczak, U. Thoma, M. A. Faessler, R.P. Haddock, S. Bischoff, P. Schmidt, W. Dünnweber, R. McCrady, Eberhard Klempt, P. Blüm, S. Spanier, C. Kolo, N. Djaoshvili, J. Adomeit, D. Walther, C.A. Baker, M. Benayoun, M. Suffert, R. Seibert, H. Kalinowsky, and J. Meier

Subjects
Physics, Nuclear and High Energy Physics, Annihilation, Protonium, Cascade, Partial wave analysis, P wave, Mass spectrum, Resonance, Dalitz plot, Atomic physics
Abstract

A partial wave analysis is presented of two high-statistics data samples of protonium annihilation into π 0 π 0 η in liquid and 12 atm gaseous hydrogen. The contributions from the 1 S 0 , 3 P 1 and 3 P 2 initial atomic fine structure states to the two data sets are different. The change of their fractional contributions when going from liquid to gaseous H 2 as calculated in a cascade model is imposed in fitting the data. Thus the uncertainty in the fraction of S-state and P-state capture is minimized. Both data sets allow a description with a common set of resonances and resonance parameters. The inclusion of a π η P-wave in the fit gives supportive evidence for the ρ (1405) , with parameters compatible with previous findings.

Published
1999
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6. p¯pannihilation at rest intoKLK±π∓

Author

D. Walther, F. H. Heinsius, C. Völcker, M. A. Faessler, R.P. Haddock, U. Strohbusch, C. Pietra, J. Lüdemann, Marcel Kunze, P. Schmidt, K. Braune, W. Dünnweber, R. McCrady, C.J. Batty, H. Stöck, U. Wiedner, Herbert Koch, Č. Zupančič, A. Ehmanns, Claude Amsler, C.A. Baker, R. Landua, M. Ratajczak, U. Kurilla, A. Berdoz, R. Ouared, Michael Doser, M. Benayoun, B. Pick, S. M. Spanier, Pàl Hidas, P. Blüm, Kenneth M. Crowe, U. Thoma, M. Tischhäuser, Farid Ould-Saada, C. A. Meyer, C. Kolo, M. Suffert, R. Seibert, W. Roethel, M. Lakata, K. Beuchert, D. Jamnik, D. Engelhardt, O. Cramer, A. Abele, J. Adomeit, S. Wallis, K. Peters, H. Kalinowsky, J. Meier, S. Bischoff, P. Kammel, K. Wittmack, P. Giarritta, C. Holtzhaußen, J. Kisiel, S. Resag, T. Degener, M. Herz, A. Herbstrith, T. Case, H. Matthäy, C. N. Pinder, S. v. Dombrowski, Eberhard Klempt, L. Montanet, M. Heinzelmann, B. M. Barnett, V. Crede, B. Kämmle, C. Regenfus, Nigel Hessey, C. Strassburger, and N. Djaoshvili

Subjects
Physics, Nuclear and High Energy Physics, Crystallography, Annihilation, Branching fraction, Partial wave analysis, Pi, Dalitz plot, K matrix
Abstract

We present a measurement and partial wave analysis of the final state ${K}_{L}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}$ of $\overline{p}p$ annihilation at rest in liquid hydrogen. This reaction is important for the study of the $\overline{K}K$ decay mode of scalar resonances, in particular, the isovectors ${a}_{0}(980)$ and ${a}_{0}(1450).$ The determination of the ${a}_{0}(1450)$ production also fixes the $\overline{K}K$ coupling of the isoscalar ${f}_{0}(1500)$ which is discussed as a glueball. We find $B(\overline{p}\stackrel{\ensuremath{\rightarrow}}{p}{a}_{0}(1450)\ensuremath{\pi}{;a}_{0}(1450)\ensuremath{\rightarrow}\overline{K}K)=(8.88\ifmmode\pm\else\textpm\fi{}1.68)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and hence $B(\overline{p}\stackrel{\ensuremath{\rightarrow}}{p}{f}_{0}(1500)\ensuremath{\pi}{;f}_{0}(1500)\ensuremath{\rightarrow}\overline{K}K)=(4.52\ifmmode\pm\else\textpm\fi{}0.36)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}.$ The mass and width of ${a}_{0}(1450)$ are $m=1480\ifmmode\pm\else\textpm\fi{}30\mathrm{MeV}{/c}^{2}$ and $\ensuremath{\Gamma}=265\ifmmode\pm\else\textpm\fi{}15\mathrm{MeV}{/c}^{2},$ respectively. For ${a}_{0}(980)$ we determine the relative ratio $B(\overline{p}\stackrel{\ensuremath{\rightarrow}}{p}{a}_{0}\ensuremath{\pi}{;a}_{0}\ensuremath{\rightarrow}\overline{K}K)/B(\overline{p}\stackrel{\ensuremath{\rightarrow}}{p}{a}_{0}\ensuremath{\pi}{;a}_{0}\ensuremath{\rightarrow}\ensuremath{\pi}\ensuremath{\eta})$ =0.23\ifmmode\pm\else\textpm\fi{}0.05 and its relative coupling, $\overline{K}K$ to \ensuremath{\pi}\ensuremath{\eta}, is $1.03\ifmmode\pm\else\textpm\fi{}0.14.$

Published
1998
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7. Exotic ηπ state in annihilation at rest into π−π0η pspectator

Author

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

Subjects
Nuclear physics, Momentum, Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Deuterium, Proton, Antiproton, Resonance, Dalitz plot, Quantum number
Abstract

With antiprotons stopped in liquid deuterium, the p n annihilation channel π−π0η was studied using a final sample of 52 576 events obtained for a spectator proton momentum q q quantum numbers IG=1−, JPC=1−+. The extracted Breit-Wigner resonance parameters are m=(1400±20±20) MeV/c2 and Γ=(310±50+50−30) MeV/c2.

Published
1998
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8. Study of at rest

Author

T. Case, H. Matthäy, A. Berdoz, S. Wallis, B. S. Zou, M. Suffert, R. Seibert, P. Kammel, M. Ratajczak, I. Scott, B.M. Barnett, A. Ehmanns, R. Ouared, C. Holtzhaußen, Nigel Hessey, C. Kolo, F. H. Heinsius, R. Landua, B. Pick, Pàl Hidas, H. Stöck, J. Kisiel, C. Völcker, P. Blüm, N. Djaoshvili, Eberhard Klempt, Marcel Kunze, D.V. Bugg, S. Bischoff, K. Wittmack, V. Crede, T. Degener, S. Resag, A. Herbstrith, O. Cramer, M. A. Faessler, M. Herz, U. Kurilla, C.A. Baker, U. Thoma, C. Hodd, J. Adomeit, P. Schmidt, Herbert Koch, C. Regenfus, M. Lakata, W. Dünnweber, A.N. Sarantsev, R. McCrady, M. Benayoun, K. Braune, C. A. Meyer, Kenneth M. Crowe, C. N. Pinder, W. Röthel, H. Kalinowsky, J. Meier, U. Wiedner, M. Tischhäuser, K. Beuchert, D. Jamnik, D. Engelhardt, A. Abele, R. P. Haddock, D. Walther, U. Strohbusch, C. Straßburger, Michael Doser, D. Ryabchikov, L. Montanet, B. Kämmle, C.J. Batty, and K. Peters

Subjects
Physics, Nuclear and High Energy Physics, Annihilation, Amplitude, Meson, Hydrogen, chemistry, Branching fraction, Mass spectrum, Resonance, chemistry.chemical_element, Atomic physics, Bar (unit)
Abstract

Crystal Barrel data are presented on p−p → ηπ0π0π0 at rest in liquid hydrogen and also in gaseous hydrogen at 12 bar. Annihilation from the initial 3P0 state relative to 3P2 is stronger in liquid than in gas by a factor 2.46 ± 0.15, in fair agreement with a prediction by Batty. There is a definite peak due to η(1440). Liquid data determine its mass as M = 1413 MeV, Γ = 49 ± 8 MeV. The mass is, however, lower in gas than in liquid by 12 ± 3 MeV; we attribute this mass shift to interference with broad background amplitudes. The η (1440) decays dominantly to ησ: BR [a0(980)π,a0 → ηπ]/BR[ησ] = 0.4 ± 0.2. However, there is strong destructive interference between these two decay modes. There is also a strong, broad ηππ component with JPC = 0−+, consistent with an earlier analysis proposing a very wide η(1800) resonance; it contributes 31% of the ηπ0π0π0 branching ratio in liquid. At the highest ηππ masses, there are definite 2−+ and l++ signals, but we cannot establish precise resonance masses or widths. There is also evidence for the production of f2 (1565), decaying to a2 (1320)π.

Published
1998
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9. Momentum dependence of the decay η→π+π−π0

Author

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

Subjects
Crystal, Nuclear physics, Momentum, Physics, Nuclear and High Energy Physics, Chiral perturbation theory, Physics::Instrumentation and Detectors, Detector, Barrel (horology), Dalitz plot
Abstract

The π 0 momentum dependence of the decay η → π + π − π 0 has been measured with the Crystal Barrel detector. The analysis is based on 3230 events. The results of this independent measurement are compared to new chiral perturbation theory calculations and previous measurements.

Published
1998
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10. Intimate partner violence and HIV treatment adherence in urban South Africa: Mediating role of perinatal common mental disorders

Author

A.M. Hatcher, J.M. Turan, H. Stöckl, N. Woollett, C. Garcia-Moreno, and N.J. Christofides

Subjects
Intimate partner violence, HIV, Antiretroviral adherence, Perinatal common mental disorders, Structural equation modeling, Mental healing, RZ400-408, Public aspects of medicine, RA1-1270
Abstract

Background: Antiretroviral therapy (ART) has potential to eliminate perinatal HIV infections, but adherence to ART in late pregnancy and postpartum is often suboptimal. Intimate partner violence (IPV) may influence non-adherence among perinatal women living with HIV (WWH), but few quantitative studies have examined this over time or explored mechanisms for this association. Methods: We used secondary data from a parent trial in Johannesburg comprising WWH from the control arm (n=63) and WWH ineligible for the trial (n=133). Trained nurse researchers administered questionnaires at first antenatal visit on past-year psychological, physical, and/or sexual IPV (WHO instrument), socio-demographics (age, food security, education), and perinatal common mental symptoms of depression (Hospital Anxiety and Depression Screener-d); anxiety (HADS-a); post-traumatic stress disorder (PTSD; Harvard Trauma Questionnaire). At endline visit 2-4 months postpartum, nurse researchers assessed self-reported ART adherence using a visual analog scale (with ≥95% considered “good”). We fitted structural equation models (SEM) in MPlus to explore direct and indirect effects of IPV on ART adherence. Results: Of 196 perinatal WWH, 53.1% reported IPV exposure at baseline. The majority of participants (85.7%) had good perinatal ART adherence. In adjusted models, IPV at baseline was associated with halved odds of good adherence (aOR=0.51, 95%CI=0.20-0.96). IPV was associated with higher adjusted odds of probable depression (aOR=4.64), anxiety (aOR=2.85), and PTSD (aOR=3.42). In SEM, IPV had a direct (standardized coef=-0.22) and indirect effect (coef=-0.05) on ART via common mental disorders. The total effect of IPV on perinatal adherence was of moderate size (coef= -0.27) and the model had good fit (CFI=0.972; TLI=0.969; RMSEA=0.045; SRMR=0.076). Conclusion: IPV was longitudinally associated with perinatal ART non-adherence in part due to its relationship with mental health symptomology. Addressing IPV within clinical care has potential to improve perinatal mental health, maternal HIV outcomes, and HIV-free infant survival.

Published
2022
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11. Antiproton-proton annihilation at rest into KK±π∓π - manifestations of isospin interference

Author

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

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Amplitude, Antiproton, Isospin, Strangeness
Abstract

The decay p p ( at rest ) → K L o K ± π ∓ π o , studied on a sample of more than 14000 events, is found to proceed dominantly via two-body channels containing resonances with open strangeness. Contributions from K 1 (1270) K and K 1 (1400) K , branching into the successive K1-decay modes, and from K ∗ K ∗ , K ∗ ( K π) s and (Kπ) s ( K π) s are extracted by means of a partial-wave analysis which accounts well for the data and also allows a search for weak contributions from other (Kππ) and from ( K K π ) resonances. Striking asymmetries between the charged and the neutral kaonic resonances give evidence for interfering isospin 0 and 1 annihilation amplitudes.

Published
1997
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12. Antiproton-proton annihilation at rest into KKπ0π0

Author

A. Abele, J. Adomeit, C. Amsler, C.A. Baker, B.M. Barnett, C.J. Batty, M. Benayoun, A. Berdoz, K. Beuchert, S. Bischoff, P. Blüm, K. Braune, D.V. Bugg, T. Case, O. Cramer, V. Credé, K.M. Crowe, T. Degener, N. Djaoshvili, S.v. Dombrowski, M. Doser, W. Dünnweber, A. Ehmanns, D. Engelhardt, M.A. Faessler, C. Felix, P. Giarritta, R.P. Haddock, F.H. Heinsius, M. Heinzelmann, M. Herz, N.P. Hessey, P. Hidas, C. Hodd, C. Holtzhaußen, D. Jamnik, H. Kalinowsky, B. Kämmle, P. Kammel, J. Kisiel, E. Klempt, H. Koch, C. Kolo, M. Kunze, U. Kurilla, M. Lakata, R. Landua, H. Matthäy, R. McCrady, J. Meier, C.A. Meyer, L. Montanet, R. Ouared, F. Ould-Saada, K. Peters, B. Pick, C. Pietra, C.N. Pinder, M. Ratajcak, C. Regenfus, J. Reißmann, S. Resag, W. Roethel, P. Schmidt, I. Scott, R. Seibert, S. Spanier, H. Stöck, C. Straßburger, U. Strohbusch, M. Suffert, U. Thoma, M. Tischhäuser, C. Völcker, S. Wallis, D. Walther, U. Wiedner, B.S. Zou, and Č. Zupančič

Subjects
Physics, Nuclear and High Energy Physics, Annihilation, Proton, 010308 nuclear & particles physics, Branching fraction, Partial wave analysis, Dalitz plot, 01 natural sciences, Crystal, Nuclear physics, Angular distribution, Antiproton, 0103 physical sciences, Atomic physics, 010306 general physics
Abstract

The annihilation channel p p →K + K − π 0 in liquid hydrogen at rest has been studied with the Crystal Barrel detector at LEAR. The measured branching ratio is: BR ( p p → K + K − π 0 )=(2.37±0.15)×10 −3 . A partial wave analysis shows that this reaction is dominated by the π (K K ) S , K K ∗ (892) and π φ (1020) intermediate states. Weak signals are observed for π a 2 (1320), π f 2 (1270), π f 2 ′(1525) and K(Kπ) S . A satisfactory description of the Dalitz plot requires the introduction of π (K K ) P intermediate states with at least one pole.

Published
1997
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13. Measurement of the ω → ηγ decay branching ratio

Author

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

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Meson, Branching fraction, Radiative decay, Mixing (physics)
Abstract

We have measured the branching ratio for the radiative decay ω → ηγ with ω mesons produced in antiproton-proton annihilation at rest into π0ω and ηω. Taking into account ϱ - ω mixing we find a branching ratio B(ω → ηγ) = (6.6 ± 1.7) × 10−4, in accord with the constructive interference solution in other experiments. The upper-limit for the direct radiative decay ω → 3γ is 1.9 × 10−4 at 95% confidence level.

Published
1997
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14. ϱ-ω interference in p-annihilation at rest into π+π−η

Author

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

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Amplitude, Annihilation, Meson, Invariant mass, Atomic physics, Coherence (physics)
Abstract

The π + π − invariant mass distribution produced in p p annihilation at rest and recoiling against η mesons exhibits large interference between the amplitudes for ϱη and ωη production. The interference can be quantitatively described within the framework of ϱ-ω interference. We find full coherence between the ϱω-ωη production amplitudes and a vanishing relative production phase. The implications of this result for p p annihilation dynamics are discussed.

Published
1997
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15. Study of the ππη′ final state in p̄p annihilation at rest

Author

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

Subjects
Nuclear physics, Physics, Rest (physics), Nuclear and High Energy Physics, Particle physics, Annihilation, Branching fraction, Partial wave analysis, State (functional analysis)
Abstract

A partial wave analysis of pp → π0π0η′ has been performed using the η′ → π0π0η and η′ → γγ decay modes. The data are dominated by an η′ recoiling against the (ππ) S-wave. In addition, α2 (1320) → η′π0 is needed. There is evidence for contributions from α0(1450) → η′π0. The branching ratio of α0(1450) → η′π0 with respect to ηπ0 is consistent with the prediction of SU(3).

Published
1997
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16. 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
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17. 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
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18. 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
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19. 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
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20. 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
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21. 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
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22. 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
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23. First observation of the production of nucleon resonances in antiproton annihilation in liquid deuterium

Author

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

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Deuterium, Antiproton, Nucleon, Particle Physics - Experiment
Published
1995
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24. 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
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25. 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
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26. 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
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27. New analysis of the radiative decayω→ηγin proton-antiproton annihilation at rest

Author

C. Kolo, C.A. Baker, Kenneth M. Crowe, J.S. Suh, B.S. Zou, H. Kalinowsky, J. Meier, W. Roethel, F. H. Heinsius, K. Peters, C. Völcker, S. Bischoff, U. Wiedner, C. Straßburger, D. Jamnik, M. Ratajczak, D. Engelhardt, R. Landua, Marcel Kunze, R. Ouared, U. Kurilla, A. Abele, S. Wallis-Plachner, C.J. Batty, B. M. Barnett, B. Pick, M. Suffert, R. Seibert, M. Lakata, I. Uman, M. A. Faessler, T. Degener, R.P. Haddock, P. Kammel, A. Herbstrith, Pàl Hidas, M. Herz, D. Walther, T. Case, H. Matthäy, K. Wittmack, J. Kisiel, U. Thoma, C. Hodd, H. Stöck, C. Holtzhaußen, K. Braune, U. Strohbusch, W. Dünnweber, R. McCrady, J. Adomeit, Michael Doser, Nigel Hessey, M. Tischhäuser, P. Blüm, D.V. Bugg, Herbert Koch, Eberhard Klempt, A. Berdoz, and C. A. Meyer

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, Proton, Antiproton, Branching fraction, High Energy Physics::Phenomenology, Radiative transfer, Radiative decay, Degree of coherence, Omega
Abstract

We report on a measurement of the branching ratio of the rare decay $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\omega}}\ensuremath{\eta}\ensuremath{\gamma}$ relative to the well known decay $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\omega}}{\ensuremath{\pi}}^{0}\ensuremath{\gamma}.$ The \ensuremath{\omega}'s are produced in $p\overline{p}\ensuremath{\rightarrow}\ensuremath{\eta}\ensuremath{\omega}$ and $p\overline{p}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}\ensuremath{\omega}.$ Eigenstate mixing and interference effects of the \ensuremath{\omega} and ${\ensuremath{\rho}}^{0}$ are taken into account, as well as coherent interference with the background. We find evidence for the non-resonant annihilation channel $B(p\overline{p}\ensuremath{\rightarrow}\ensuremath{\eta}\ensuremath{\eta}\ensuremath{\gamma})=(3.5\ifmmode\pm\else\textpm\fi{}1.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ and limit the value of $B(\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\omega}}\ensuremath{\eta}\ensuremath{\gamma})$ to the range of $(0.7\mathrm{to}5.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ depending on the degree of coherence with the background.

Published
2000
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28. Antiproton-proton annihilation at rest into $K^{+}K^{-}\pi^{0}$

Author

A. Abele, J. Adomeit, C. Amsler, C.A. Baker, B.M. Barnett, C.J. Batty, M. Benayoun, A. Berdoz, S. Bischoff, P. Blüm, K. Braune, D.V. Bugg, T. Case, O. Cramer, K.M. Crowe, T. Degener, M. Doser, W. Dünnweber, D. Engelhardt, M.A. Faessler, P. Giarritta, R.P. Haddock, F.H. Heinsius, M. Heinzelmann, A. Herbstrith, M. Herz, N.P. Hessey, P. Hidas, C. Hodd, C. Holtzhaußen, D. Jamnik, H. Kalinowsky, P. Kammel, J. Kisiel, E. Klempt, H. Koch, M. Kunze, U. Kurilla, M. Lakata, R. Landua, H. Matthäy, R. McCrady, J. Meier, C.A. Meyer, R. Ouared, K. Peters, B. Pick, M. Ratajczak, C. Regenfus, W. Roethel, R. Seibert, S. Spanier, H. Stöck, C. Straßburger, U. Strohbusch, M. Suffert, J.S. Suh, U. Thoma, M. Tischhäuser, I. Uman, C. Völcker, S. Wallis-Plachner, D. Walther, U. Wiedner, K. Wittmack, and B.S. Zou

Subjects
Rest (physics), Physics, Nuclear physics, Nuclear and High Energy Physics, Annihilation, Proton, Antiproton, Hadron physics, Particle Physics - Experiment
Abstract

The annihilation channel pp to K/sup +/K/sup -/ pi /sup 0/ in liquid hydrogen at rest has been studied with the Crystal Barrel detector at LEAR. The measured branching ratio is: BR(pp to K/sup +/K/sup -/ pi /sup 0/)=(2.37+or-0.15)*10/sup -3/. A partial wave analysis shows that this reaction is dominated by the pi (KK)/sub S/, KK*(892) and pi phi (1020) intermediate states. Weak signals are observed for pi a /sub 2/(1320), pi f/sub 2/(1270), pi f/sub 2/'(1525) and K(K pi )/sub S/. A satisfactory description of the Dalitz plot requires the introduction of pi (KK)/sub P/ intermediate states with at least one pole. (25 refs).

Published
1999

29. Observation of f0(1500) decay into K(L) K(L)

Author

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

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Amplitude, Annihilation, OZI rule, Particle Physics - Experiment, Production rate
Abstract

The f 0 (1500) is observed in its K K decay mode in an amplitude analysis of high statistics data in p p annihilation at rest into π 0 K L K L . The mass and width is found to be ( m , Γ ) = (1515 ± 20, 105 ± 15) MeV. A comparison of the decay rate into 2 π 0 shows that this state cannot be dominantly s s . The f ′ 2 (1525) has been observed for the first time in p p annihilation and its production rate is consistent with the expectation from the OZI rule.

Published
1996

32. Corrigendum to 'Isoscalar single-pion production in the region of Roper and d⁎(2380) resonances' [Phys. Lett. B 774 (2017) 599]

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, H. Bhatt, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, E. Czerwiński, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, C.-O. Gullström, L. Heijkenskjöld, V. Hejny, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, O. Khreptak, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, H.-P. Morsch, P. Moskal, H. Ohm, W. Parol, E. Perez del Rio, N.M. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schätti-Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, K. Sitterberg, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Trzciński, R. Varma, M. Wolke, A. Wrońska, P. Wüstner, A. Yamamoto, J. Zabierowski, M.J. Zieliński, J. Złomańczuk, P. Żuprański, and M. Żurek

Subjects
Physics, QC1-999
Published
2020
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33. Search for η mesic 3He with the WASA-at-COSY facility in the pd→3He2γ and pd→3He6γ reactions

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, S.D. Bass, M. Berłowski, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, E. Czerwiński, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, L. Heijkenskjöld, V. Hejny, S. Hirenzaki, L. Jarczyk, T. Johansson, B. Kamys, N.G. Kelkar, G. Kemmerling, A. Khreptak, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, H.-P. Morsch, P. Moskal, H. Ohm, W. Parol, E. Perez del Rio, N.M. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, J. Ritman, A. Roy, O. Rundel, S. Sawant, S. Schadmand, I. Schätti–Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Trzciński, M. Wolke, A. Wrońska, P. Wüstner, A. Yamamoto, J. Zabierowski, M.J. Zieliński, J. Złomańczuk, P. Żuprański, and M. Żurek

Subjects
Physics, QC1-999
Abstract

We report on the experimental search for the bound state of an η meson and He3 nucleus performed using the WASA-at-COSY detector setup. In order to search for the η-mesic nucleus decay, the pd→3He2γ and pd→3He6γ channels have been analysed. These reactions manifest the direct decay of the η meson bound in a He3 nucleus. This non-mesonic decay channel has been considered for the first time. When taking into account only statistical errors, the obtained excitation functions reveal a slight indication for a possible bound state signal corresponding to a 3He-η nucleus width Γ above 20 MeV and binding energy Bs between 0 and 15 MeV. However, the determined cross sections are consistent with zero in the range of the systematic uncertainty. Therefore, as final result we estimate only the upper limit for the cross section of the η-mesic He3 nucleus formation followed by the η meson decay which varies between 2 nb and 15 nb depending on possible bound state parameters. Keywords: η-mesic nuclei, η meson

Published
2020
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34. Search for C violation in the decay η → π0e+e− with WASA-at-COSY

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, E. Czerwiński, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, C.-O. Gullström, L. Heijkenskjöld, V. Hejny, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, A. Khreptak, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, H.-P. Morsch, P. Moskal, H. Ohm, W. Parol, E. Perez del Rio, N.M. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schätti-Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, K. Sitterberg, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Trzciński, M. Wolke, A. Wrońska, P. Wüstner, A. Yamamoto, J. Zabierowski, M.J. Zieliński, J. Złomańczuk, P. Żuprański, M. Żurek, and A. Wirzba

Subjects
Physics, QC1-999
Abstract

We report on the search for the rare decay η→π0e+e− which is of interest to study C violation in the electromagnetic interaction which would indicate contributions from physics beyond the Standard Model, since the allowed decay via a two-photon intermediate state is strongly suppressed. The experiment has been performed using the WASA-at-COSY installation, located at the COSY accelerator of the Forschungszentrum Jülich, Germany. In total 3×107 events of the reaction pd→3Heη have been recorded at an excess energy of Q=59.8MeV. Based on this data set the C parity violating decay η→π0γ⁎→π0e+e− via a single-photon intermediate state has been searched for, resulting in new upper limits of Γ(η→π0e+e−)/Γ(η→π+π−π0)

Published
2018
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35. Total and differential cross sections of η-production in proton–deuteron fusion for excess energies between Qη = 13 MeV and Qη = 81 MeV

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, E. Czerwiński, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, C.-O. Gullström, L. Heijkenskjöld, V. Hejny, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, A. Khreptak, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, H.-P. Morsch, P. Moskal, H. Ohm, W. Parol, E. Perez del Rio, N.M. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schätti-Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, K. Sitterberg, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Trzciński, M. Wolke, A. Wrońska, P. Wüstner, A. Yamamoto, J. Zabierowski, M.J. Zieliński, J. Złomańczuk, P. Żuprański, M. Żurek, and C. Wilkin

Subjects
Physics, QC1-999
Abstract

New data on both total and differential cross sections of the production of η mesons in proton–deuteron fusion to He3η in the excess energy region 13.6MeV≤Qη≤80.9MeV are presented. These data have been obtained with the WASA-at-COSY detector setup located at the Forschungszentrum Jülich, using a proton beam at 15 different beam momenta between pp=1.60GeV/c and pp=1.74GeV/c. While significant structure of the total cross section is observed in the energy region 20MeV≲Qη≲60MeV, a previously reported sharp variation around Qη≈50MeV cannot be confirmed. Angular distributions show the typical forward-peaking that was noted earlier. For the first time, it is possible to study the development of these angular distributions with rising excess energy over a wide interval. Keywords: Meson production, Proton–deuteron interactions, η meson

Published
2018
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36. Importance of d-wave contributions in the charge symmetry breaking reaction dd→4Heπ0

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, E. Czerwiński, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, C.-O. Gullström, C. Hanhart, L. Heijkenskjöld, V. Hejny, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, O. Khreptak, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, H.-P. Morsch, P. Moskal, H. Ohm, W. Parol, E. Perez del Rio, N.M. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schätti-Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, K. Sitterberg, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Trzciński, M. Wolke, A. Wrońska, P. Wüstner, A. Yamamoto, J. Zabierowski, M.J. Zieliński, J. Złomańczuk, P. Żuprański, and M. Żurek

Subjects
Physics, QC1-999
Abstract

This letter reports a first quantitative analysis of the contribution of higher partial waves in the charge symmetry breaking reaction dd→4Heπ0 using the WASA-at-COSY detector setup at an excess energy of Q=60MeV. The determined differential cross section can be parametrized as dσ/dΩ=a+bcos2⁡θ⁎, where θ⁎ is the production angle of the pion in the center-of-mass coordinate system, and the results for the parameters are a=(1.55±0.46(stat)+0.32−0.8(syst))pb/sr and b=(13.1±2.1(stat)−2.7+1.0(syst))pb/sr. The data are compatible with vanishing p-waves and a sizable d-wave contribution. This finding should strongly constrain the contribution of the Δ isobar to the dd→4Heπ0 reaction and is, therefore, crucial for a quantitative understanding of quark mass effects in nuclear production reactions. Keywords: Charge symmetry breaking, Deuteron–deuteron interactions, Pion production

Published
2018
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37. Conserved charge fluctuations are not conserved during the hadronic phase

Author

J. Steinheimer, V. Vovchenko, J. Aichelin, M. Bleicher, and H. Stöcker

Subjects
Physics, QC1-999
Abstract

We study the correlation between the distributions of the net-charge, net-kaon, net-baryon and net-proton number at hadronization and after the final hadronic decoupling by simulating ultra relativistic heavy ion collisions with the hybrid version of the ultrarelativistic quantum molecular dynamics (UrQMD) model. We find that due to the hadronic rescattering these distributions are not strongly correlated. The calculated change of the correlation, during the hadronic expansion stage, does not support the recent paradigm, namely that the measured final moments of the experimentally observed distributions do give directly the values of those distributions at earlier times, when the system had been closer to the QCD crossover.

Published
2018
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38. Isoscalar single-pion production in the region of Roper and d⁎(2380) resonances

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, H. Bhatt, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, E. Czerwiński, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, C.-O. Gullström, L. Heijkenskjöld, V. Hejny, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, O. Khreptak, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, H.-P. Morsch, P. Moskal, H. Ohm, W. Parol, E. Perez del Rio, N.M. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schätti-Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, K. Sitterberg, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Trzciński, R. Varma, M. Wolke, A. Wrońska, P. Wüstner, A. Yamamoto, J. Zabierowski, M.J. Zieliński, J. Złomańczuk, P. Żuprański, and M. Żurek

Subjects
Single-pion production, Isoscalar part, Roper resonance, Dibaryon resonance, Physics, QC1-999
Abstract

Exclusive measurements of the quasi-free pn→ppπ− and pp→ppπ0 reactions have been performed by means of pd collisions at Tp=1.2 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region Tp=0.95–1.3 GeV (s=2.3–2.46 GeV), which includes the regions of Δ(1232), N⁎(1440) and d⁎(2380) resonance excitations. From these measurements the isoscalar single-pion production has been extracted, for which data existed so far only below Tp=1 GeV. We observe a substantial increase of this cross section around 1 GeV, which can be related to the Roper resonance N⁎(1440), the strength of which shows up isolated from the Δ resonance in the isoscalar (Nπ)I=0 invariant-mass spectrum. No evidence for a decay of the dibaryon resonance d⁎(2380) into the isoscalar (NNπ)I=0 channel is found. An upper limit of 180 μb (90% C.L.) corresponding to a branching ratio of 9% has been deduced.

Published
2017
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39. Measurement of the ω→π+π−π0 Dalitz plot distribution

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, H. Bhatt, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, E. Czerwiński, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, C.-O. Gullström, L. Heijkenskjöld, V. Hejny, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, F.A. Khan, G. Khatri, A. Khoukaz, O. Khreptak, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, H.-P. Morsch, P. Moskal, H. Ohm, E. Perez del Rio, N.M. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schätti-Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, K. Sitterberg, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Trzciński, R. Varma, M. Wolke, A. Wrońska, P. Wüstner, A. Yamamoto, J. Zabierowski, M.J. Zieliński, J. Złomańczuk, P. Żuprański, and M. Żurek

Subjects
Decays of other mesons, Meson–meson interactions, Light mesons, Physics, QC1-999
Abstract

Using the production reactions pd→He3ω and pp→ppω, the Dalitz plot distribution for the ω→π+π−π0 decay is studied with the WASA detector at COSY, based on a combined data sample of (4.408±0.042)×104 events. The Dalitz plot density is parametrised by a product of the P-wave phase space and a polynomial expansion in the normalised polar Dalitz plot variables Z and ϕ. For the first time, a deviation from pure P-wave phase space is observed with a significance of 4.1σ. The deviation is parametrised by a linear term 1+2αZ, with α determined to be +0.147±0.036, consistent with the expectations of ρ-meson-type final-state interactions of the P-wave pion pairs.

Published
2017
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40. Search for an isospin I=3 dibaryon

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, H. Bhatt, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, E. Czerwiński, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, C.-O. Gullström, L. Heijkenskjöld, V. Hejny, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, F.A. Khan, G. Khatri, A. Khoukaz, O. Khreptak, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, H.-P. Morsch, P. Moskal, H. Ohm, E. Perez del Rio, N.M. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schätti-Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, K. Sitterberg, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Trzciński, R. Varma, M. Wolke, A. Wrońska, P. Wüstner, A. Yamamoto, J. Zabierowski, M.J. Zieliński, A. Zink, J. Złomańczuk, P. Żuprański, and M. Żurek

Subjects
Physics, QC1-999
Abstract

Various theoretical calculations based on QCD or hadronic interactions predict that in addition to the recently observed dibaryon resonance d⁎(2380) with I(JP)=0(3+) there should also exist a dibaryon resonance with mirrored quantum numbers I(JP)=3(0+). We report here on a search for such a NN-decoupled state in data on the pp→ppπ+π+π−π− reaction. Since no clear-cut evidence has been found, we give upper limits for the production cross section of such a resonance in the mass range 2280–2500 MeV. Keywords: Dibaryons, Four-pion production

Published
2016
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41. Measurement of the absolute differential cross section of proton–proton elastic scattering at small angles

Author

D. Mchedlishvili, D. Chiladze, S. Dymov, Z. Bagdasarian, S. Barsov, R. Gebel, B. Gou, M. Hartmann, A. Kacharava, I. Keshelashvili, A. Khoukaz, P. Kulessa, A. Kulikov, A. Lehrach, N. Lomidze, B. Lorentz, R. Maier, G. Macharashvili, S. Merzliakov, S. Mikirtychyants, M. Nioradze, H. Ohm, D. Prasuhn, F. Rathmann, V. Serdyuk, D. Schroer, V. Shmakova, R. Stassen, H.J. Stein, H. Stockhorst, I.I. Strakovsky, H. Ströher, M. Tabidze, A. Täschner, S. Trusov, D. Tsirkov, Yu. Uzikov, Yu. Valdau, C. Wilkin, R.L. Workman, and P. Wüstner

Subjects
Physics, QC1-999
Abstract

The differential cross section for proton–proton elastic scattering has been measured at a beam kinetic energy of 1.0 GeV and in 200 MeV steps from 1.6 to 2.8 GeV for centre-of-mass angles in the range from 12°–16° to 25°–30°, depending on the energy. A precision in the overall normalisation of typically 3% was achieved by studying the energy losses of the circulating beam of the COSY storage ring as it passed repeatedly through the windowless hydrogen target of the ANKE magnetic spectrometer. It is shown that the data have a significant impact upon the results of a partial wave analysis. After extrapolating the differential cross sections to the forward direction, the results are broadly compatible with the predictions of forward dispersion relations. Keywords: Proton–proton elastic scattering, Differential cross section

Published
2016
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42. Effect of alkaline elements on the reactivity, strength and structural properties of blast furnace cokes

Author

A. Bhattacharyya, J. Schenk, G. Rantitsch, C. Thaler, and H. Stocker

Subjects
blast furnace cokes, alkali elements, boudouard reaction, CRI and CSR, coke characterization, Mining engineering. Metallurgy, TN1-997
Abstract

The present study concerns itself on the adverse effects of alkaline elements like sodium and potassium on blast furnace cokes. To achieve a deeper insight on the effects of alkaline elements on coke reactivity and strength, industrial coke samples impregnated with different alkaline species in various amounts have been tested under standard conditions to find out their Coke Reactivity Index (CRI) and Coke Strength after Reaction (CSR) values. Scanning electron microscopy, petrographic and Raman Spectrometric investigations demonstrate the change of structural properties. The mechanism of catalysis has been postulated.

Published
2015

43. Measurement of the np→npπ0π0 reaction in search for the recently observed d⁎(2380) resonance

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, H. Bhatt, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, D. Coderre, E. Czerwiński, K. Demmich, E. Doroshkevich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, P. Goslawski, A. Goswami, K. Grigoryev, C.-O. Gullström, F. Hauenstein, L. Heijkenskjöld, V. Hejny, B. Höistad, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, F.A. Khan, A. Khoukaz, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, M. Mikirtychiants, H.-P. Morsch, P. Moskal, H. Ohm, I. Ozerianska, E. Perez del Rio, N.M. Piskunov, P. Podkopał, D. Prasuhn, A. Pricking, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, S. Sawant, S. Schadmand, T. Sefzick, V. Serdyuk, B. Shwartz, R. Siudak, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Täschner, A. Trzciński, R. Varma, G.J. Wagner, M. Wolke, A. Wrońska, P. Wüstner, P. Wurm, A. Yamamoto, J. Zabierowski, M.J. Zieliński, A. Zink, J. Złomańczuk, P. Żuprański, and M. Żurek

Subjects
Physics, QC1-999
Abstract

Exclusive measurements of the quasi-free np→npπ0π0 reaction have been performed by means of dp collisions at Td=2.27 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region s=(2.35–2.46) GeV, which includes the region of the ABC effect and its associated d⁎(2380) resonance. Adding the d⁎ resonance amplitude to that for the conventional processes leads to a reasonable description of the data. The observed resonance effect in the total cross section is in agreement with the predictions of Fäldt and Wilkin as well with those of Albadajedo and Oset. The ABC effect, i.e. the low-mass enhancement in the π0π0-invariant mass spectrum, is found to be very modest – if present at all, which might pose a problem to some of its interpretations. Keywords: Two-pion production, ABC effect and resonance structure, Dibaryon resonance

Published
2015
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44. Measurement of the analysing power in proton–proton elastic scattering at small angles

Author

Z. Bagdasarian, D. Chiladze, S. Dymov, A. Kacharava, G. Macharashvili, S. Barsov, R. Gebel, B. Gou, M. Hartmann, I. Keshelashvili, A. Khoukaz, P. Kulessa, A. Kulikov, A. Lehrach, N. Lomidze, B. Lorentz, R. Maier, D. Mchedlishvili, S. Merzliakov, S. Mikirtychyants, M. Nioradze, H. Ohm, M. Papenbrock, D. Prasuhn, F. Rathmann, V. Serdyuk, V. Shmakova, R. Stassen, H. Stockhorst, I.I. Strakovsky, H. Ströher, M. Tabidze, A. Täschner, S. Trusov, D. Tsirkov, Yu. Uzikov, Yu. Valdau, C. Wilkin, and R.L. Workman

Subjects
Physics, QC1-999
Abstract

The proton analysing power in p→p elastic scattering has been measured at small angles at COSY-ANKE at 796 MeV and five other beam energies between 1.6 and 2.4 GeV using a polarised proton beam. The asymmetries obtained by detecting the fast proton in the ANKE forward detector or the slow recoil proton in a silicon tracking telescope are completely consistent. Although the analysing power results agree well with the many published data at 796 MeV, and also with the most recent partial wave solution at this energy, the ANKE data at the higher energies lie well above the predictions of this solution at small angles. An updated phase shift analysis that uses the ANKE results together with the World data leads to a much better description of these new measurements. Keywords: Proton–proton elastic scattering, Analysing power, Phase shift analysis

Published
2014
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45. Charge symmetry breaking in dd→He4π0 with WASA-at-COSY

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, H. Bhatt, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, D. Coderre, E. Czerwiński, K. Demmich, E. Doroshkevich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, P. Goslawski, A. Goswami, K. Grigoryev, C.-O. Gullström, C. Hanhart, F. Hauenstein, L. Heijkenskjöld, V. Hejny, B. Höistad, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, F.A. Khan, A. Khoukaz, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, M. Mikirtychiants, H.-P. Morsch, P. Moskal, H. Ohm, I. Ozerianska, E. Perez del Rio, N.M. Piskunov, P. Podkopał, D. Prasuhn, A. Pricking, D. Pszczel, K. Pysz, A. Pyszniak, C.F. Redmer, J. Ritman, A. Roy, Z. Rudy, S. Sawant, S. Schadmand, T. Sefzick, V. Serdyuk, B. Shwartz, R. Siudak, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Täschner, A. Trzciński, R. Varma, M. Wolke, A. Wrońska, P. Wüstner, P. Wurm, A. Yamamoto, L. Yurev, J. Zabierowski, M.J. Zieliński, A. Zink, J. Złomańczuk, P. Żuprański, and M. Żurek

Subjects
Physics, QC1-999
Abstract

Charge symmetry breaking (CSB) observables are a suitable experimental tool to examine effects induced by quark masses on the nuclear level. Previous high precision data from TRIUMF and IUCF are currently used to develop a consistent description of CSB within the framework of chiral perturbation theory. In this work the experimental studies on the reaction dd→He4π0 have been extended towards higher excess energies in order to provide information on the contribution of p-waves in the final state. For this, an exclusive measurement has been carried out at a beam momentum of pd=1.2 GeV/c using the WASA-at-COSY facility. The total cross section amounts to σtot=(118±18stat±13sys±8ext) pb and first data on the differential cross section are consistent with s-wave pion production. Keywords: Charge symmetry breaking, Deuteron–deuteron interactions, Pion production

Published
2014
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46. Phase measurement for driven spin oscillations in a storage ring

Author

N. Hempelmann, V. Hejny, J. Pretz, H. Soltner, W. Augustyniak, Z. Bagdasarian, M. Bai, L. Barion, M. Berz, S. Chekmenev, G. Ciullo, S. Dymov, D. Eversmann, M. Gaisser, R. Gebel, K. Grigoryev, D. Grzonka, G. Guidoboni, D. Heberling, J. Hetzel, F. Hinder, A. Kacharava, V. Kamerdzhiev, I. Keshelashvili, I. Koop, A. Kulikov, A. Lehrach, P. Lenisa, N. Lomidze, B. Lorentz, P. Maanen, G. Macharashvili, A. Magiera, D. Mchedlishvili, S. Mey, F. Müller, A. Nass, N. N. Nikolaev, M. Nioradze, A. Pesce, D. Prasuhn, F. Rathmann, M. Rosenthal, A. Saleev, V. Schmidt, Y. Semertzidis, Y. Senichev, V. Shmakova, A. Silenko, J. Slim, A. Stahl, R. Stassen, E. Stephenson, H. Stockhorst, H. Ströher, M. Tabidze, G. Tagliente, R. Talman, P. Thörngren Engblom, F. Trinkel, Yu. Uzikov, Yu. Valdau, E. Valetov, A. Vassiliev, C. Weidemann, A. Wrońska, P. Wüstner, P. Zuprański, and M. Żurek

Subjects
Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

This paper reports the first simultaneous measurement of the horizontal and vertical components of the polarization vector in a storage ring under the influence of a radio frequency (rf) solenoid. The experiments were performed at the Cooler Synchrotron COSY in Jülich using a vector polarized, bunched 0.97 GeV/c deuteron beam. Using the new spin feedback system, we set the initial phase difference between the solenoid field and the precession of the polarization vector to a predefined value. The feedback system was then switched off, allowing the phase difference to change over time, and the solenoid was switched on to rotate the polarization vector. We observed an oscillation of the vertical polarization component and the phase difference. The oscillations can be described using an analytical model. The results of this experiment also apply to other rf devices with horizontal magnetic fields, such as Wien filters. The precise manipulation of particle spins in storage rings is a prerequisite for measuring the electric dipole moment (EDM) of charged particles.

Published
2018
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47. Connection between zero chromaticity and long in-plane polarization lifetime in a magnetic storage ring

Author

G. Guidoboni, E. J. Stephenson, A. Wrońska, Z. Bagdasarian, J. Bsaisou, S. Chekmenev, G. Ciullo, S. Dymov, D. Eversmann, M. Gaisser, R. Gebel, V. Hejny, N. Hempelmann, F. Hinder, A. Kacharava, I. Keshelashvili, P. Kulessa, P. Lenisa, A. Lehrach, B. Lorentz, P. Maanen, R. Maier, D. Mchedlishvili, S. Mey, A. Nass, A. Pesce, Y. Orlov, J. Pretz, D. Prasuhn, F. Rathmann, M. Rosenthal, A. Saleev, Y. K. Semertzidis, Y. Senichev, V. Shmakova, H. Stockhorst, H. Ströher, R. Talman, P. Thörngren Engblom, F. Trinkel, Yu. Valdau, C. Weidemann, P. Wüstner, M. Żurek, and D. Zyuzin

Subjects
Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

In this paper, we demonstrate the connection between a magnetic storage ring with additional sextupole fields set so that the x and y chromaticities vanish and the maximizing of the lifetime of in-plane polarization (IPP) for a 0.97-GeV/c deuteron beam. The IPP magnitude was measured by continuously monitoring the down-up scattering asymmetry (sensitive to sideways polarization) in an in-beam, carbon-target polarimeter and unfolding the precession of the IPP due to the magnetic anomaly of the deuteron. The optimum operating conditions for a long IPP lifetime were made by scanning the field of the storage ring sextupole magnet families while observing the rate of IPP loss during storage of the beam. The beam was bunched and electron cooled. The IPP losses appear to arise from the change of the orbit circumference, and consequently the particle speed and spin tune, due to the transverse betatron oscillations of individual particles in the beam. The effects of these changes are canceled by an appropriate sextupole field setting.

Published
2018
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50. [Operational evaluation studies in psychopharmacological research (presented with an example of a comparison between clomipramine and tisocromide)]

Author

G E, Kühne, J U, Grünes, and H, Stöck

Subjects
Oxathiins, Psychometrics, Computers, Heterocyclic Compounds, Mental Disorders, Research, Clomipramine, Humans
Abstract

Departing from false interpretations of results obtained in psychopharmacological studies, the mathematical-statistical methods of the trend test after WILCOXON, of the WILCOXON comparative test for processes and of the HOTELLING-PABST test are presented and discussed on the basis of a computer programme. Using the example of the psychotropics clomipramine and tisocromide, differential-typological aspects have been recognised. These permit to draw conclusions for the optimisation of pharmacotherapy as well as reactions on the psychopharmacological development research. In the appraisal of the effectiveness of psychotropic substances a greater fundamental importance should be attached to operational procedures.

Published
1980

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