P. Aguar-Bartolome

Publications (6)0 Total impact

• Article: Accurate Test of Chiral Dynamics in the \boldmath$\vec{\gamma} p \rightarrow \pi^0p$ Reaction

  D. Hornidge, P. Aguar Bartolome, J. R. M. Annand, H. J. Arends, R. Beck, V. Bekrenev, H. Berghaeuser, A. M. Bernstein, A. Braghieri, W. J. Briscoe, [......], M. H. Sikora, A. Starostin, I. Supek, M. Thiel, A. Thomas, L. Tiator, M. Unverzagt, D. P. Watts, D. Werthmueller, L. Witthauer
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  ABSTRACT: A precision measurement of the differential cross sections $d\sigma/d\Omega$ and the linearly polarized photon asymmetry $\Sigma \equiv \left(d\sigma_\perp - d\sigma_\parallel \right) \slash \left(d\sigma_\perp + d\sigma_\parallel \right)$ for the $\vec{\gamma} p \rightarrow \pi^0p$ reaction in the near-threshold region has been performed with a tagged photon beam and almost $4\pi$ detector at the Mainz Microtron. The Glasgow-Mainz photon tagging facility along with the Crystal Ball/TAPS multi-photon detector system and a cryogenic liquid hydrogen target were used. These data allowed for a precise determination of the energy dependence of the real parts of the $S$- and all three $P$-wave amplitudes for the first time and provide the most stringent test to date of the predictions of Chiral Perturbation Theory and its energy region of agreement with experiment.
  11/2012;
• Source

  Available from: W. J. Briscoe

  Article: Photoproduction of pi^0 eta on protons and the Delta(1700)D_{33} resonance

  V. L. Kashevarov, A. Fix, P. Aguar-Bartolome, L. K. Akasoy, J. R. M. Annand, H.J. Arends, K. Bantawa, R. Beck, V. Bekrenev, H. Berghauser, [......], A. Starostin, I. M. Suarez, I. Supek, C. M. Tarbert, M. Thiel, A Thomas, M. Unverzagt, D. P. Watts, I. Zamboni, F. Zehr
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  ABSTRACT: Total and differential cross sections for the reaction gamma p -> pi^o eta p have been measured with the Crystal Ball/TAPS detector using the tagged photon facility at the MAMI C accelerator in Mainz. In the energy range E_gamma=0.95-1.4 GeV the reaction is dominated by the excitation and sequential decay of the Delta(1700)D33 resonance. Angular distributions measured with high statistics allow us to determine the ratio of hadronic decay widths \Gamma_{\eta \Delta}/\Gamma_{\pi S11} and the ratio of the helicity amplitudes A_{3/2}/A_{1/2} for this resonance. Comment: 9 pages, 11 figures
  01/2009;
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  Available from: W. J. Briscoe

  Article: Determination of the Dalitz plot parameter alpha for the decay eta->3pi^0 with the Crystal Ball at MAMI-B

  M. Unverzagt, P. Aguar-Bartolome, J. Ahrens, J. R. M. Annand, H.J. Arends, R. Beck, V. Bekrenev, B Boillat, A. Braghieri, D Branford, [......], T. Rostomyan, S. Schumann, D. Sober, A. Starostin, I. Supek, C. M. Tarbert, A Thomas, Th. Walcher, D. P. Watts, F. Zehr
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  ABSTRACT: A precise measurement of the Dalitz plot parameter, alpha, for the eta->3pi^0 decay is presented. The experiment was performed with the Crystal Ball and TAPS large acceptance photon detectors at the tagged photon beam facility of the MAMI-B electron accelerator in Mainz. High statistics of 1.8*10^6 eta->3pi^0 events were obtained, giving the result alpha = -0.032 +/- 0.002(stat) +/- 0.002(syst). Comment: 9 pages, 6 figures, published in the online-first section of EPJ A, included changes referees asked for, added DOI
  12/2008;
• Source

  Available from: W. J. Briscoe

  Article: Measurement of the Slope Parameter $\alpha$ for the $\eta\to 3\pi^0$ decay with the Crystal Ball detector at the Mainz Microtron (MAMI-C)

  S. Prakhov, B. M. K. Nefkens, P. Aguar-Bartolome, L. K. Akasoy, J. R. M. Annand, H.J. Arends, K. Bantawa, R. Beck, V. Bekrenev, H. Berghauser, [......], A. Starostin, I. M. Suarez, I. Supek, C. M. Tarbert, M. Thiel, A Thomas, M. Unverzagt, D. P. Watts, I. Zamboni, F. Zehr
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  ABSTRACT: The dynamics of the $\eta\to 3\pi^0$ decay have been studied with the Crystal Ball multiphoton spectrometer and the TAPS calorimeter. Bremsstrahlung photons produced by the 1.5-GeV electron beam of the Mainz microtron MAMI-C and tagged by the Glasgow photon spectrometer were used for $\eta$-meson production. The analysis of $3 \times 10^6$ $\gamma p \to \eta p \to 3\pi^0 p \to 6\gamma p$ events yields the value $\alpha=-0.032\pm0.003$ for the $\eta\to 3\pi^0$ slope parameter, which agrees with the majority of recent experimental results and has the smallest uncertainty. The $\pi^0\pi^0$ invariant-mass spectrum was investigated for the occurrence of a cusplike structure in the vicinity of the $\pi^+\pi^-$ threshold. The observed effect is small and does not affect our measured value for the slope parameter.
  12/2008;
• Article: Determination of the Dalitz plot parameter alpha for the decay eta -> 3 pi(0) with the Crystal Ball at MAMI-B

  M. Unverzagt, P. Aguar-Bartolome, J. Ahrens, JRM Annand, HJ Arends, R. Beck, V. Bekrenev, B Boillat, A. Braghieri, D Branford, [......], T. Rostomyan, S. Schumann, D. Sober, A. Starostin, I. Supek, CM Tarbert, A Thomas, T Walcher, DP Watts, F. Zehr
• Article: Photoproduction of pi(0)eta on protons and the Delta(1700)D-33-resonance

  VL Kashevarov, A. Fix, P. Aguar-Bartolome, LK Akasoy, JRM Annand, HJ Arends, K. Bantawa, R. Beck, V. Bekrenev, H. Berghauser, [......], A. Starostin, IM Suarez, I. Supek, CM Tarbert, M. Thiel, A Thomas, M. Unverzagt, DP Watts, I. Zamboni, F. Zehr