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A2 Collaboration at MAMI. High statistics angular distributions and total cross sections for the photoproduction of $\pi^0$ mesons off the deuteron with coincident detection of recoil nucleons have been measured for the first time. The experiment was performed at the tagged photon beam of the Mainz Microtron (MAMI) for photon energies between 0.45 and 1.4 GeV, using an almost 4$\pi$ electromagnetic calorimeter composed of the Crystal Ball and TAPS detectors. A complete kinematic reconstruction of the final state removed the effects of Fermi motion. Significant effects from final-state interactions (FSI) were observed for participant protons in comparison to free proton targets (between 30% and almost 40%). The data in coincidence with recoil neutrons were corrected for such effects under the assumption that they are identical for participant protons and neutrons. The total overall systematic uncertainty was estimated at 7%. Excitation function at cos(Theta_pi0)cm = -0.25

A2 Collaboration at MAMI. Precise helicity-dependent cross sections and the double-polarization observable E were measured for $\eta$ photoproduction from quasifree protons and neutrons bound in the deuteron. The $2\gamma$ and $3\pi^0$ decay modes were used to optimize the statistical quality of the data and to estimate systematic uncertainties. The measurement used the A2 detector setup at the tagged photon beam of the electron accelerator MAMI in Mainz. A longitudinally polarized deuterated butanol target was used in combination with a circularly polarized photon beam from bremsstrahlung of a longitudinally polarized electron beam. The reaction products were detected with the electromagnetic calorimeters Crystal Ball and TAPS, which covered 98% of the full solid angle. The main systematic uncertainty of the E asymmetry is related to the measurement of the beam and target polarizations. The uncertainty of the photon polarization degree was determined to be ±2.7%. The uncertainty of the target polarization was estimated as ±10%. Diff. cross section for helicity-1/2 at W= 1.772 GeV

A2 Collaboration at MAMI. High statistics angular distributions and total cross sections for the photoproduction of $\pi^0$ mesons off the deuteron with coincident detection of recoil nucleons have been measured for the first time. The experiment was performed at the tagged photon beam of the Mainz Microtron (MAMI) for photon energies between 0.45 and 1.4 GeV, using an almost 4$\pi$ electromagnetic calorimeter composed of the Crystal Ball and TAPS detectors. A complete kinematic reconstruction of the final state removed the effects of Fermi motion. Significant effects from final-state interactions (FSI) were observed for participant protons in comparison to free proton targets (between 30% and almost 40%). The data in coincidence with recoil neutrons were corrected for such effects under the assumption that they are identical for participant protons and neutrons. The total overall systematic uncertainty was estimated at 7%. Excitation function at cos(Theta_pi0)cm = 0.85

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures. Related Article: Andreas Heilmann, Matthew M. D. Roy, Agamemnon E. Crumpton, Liam P. Griffin, Jamie Hicks, Jose M. Goicoechea, Simon Aldridge|2022|J.Am.Chem.Soc.|144|12942|doi:10.1021/jacs.2c05228

A2 Collaboration at MAMI. Precise helicity-dependent cross sections and the double-polarization observable E were measured for $\eta$ photoproduction from quasifree protons and neutrons bound in the deuteron. The $2\gamma$ and $3\pi^0$ decay modes were used to optimize the statistical quality of the data and to estimate systematic uncertainties. The measurement used the A2 detector setup at the tagged photon beam of the electron accelerator MAMI in Mainz. A longitudinally polarized deuterated butanol target was used in combination with a circularly polarized photon beam from bremsstrahlung of a longitudinally polarized electron beam. The reaction products were detected with the electromagnetic calorimeters Crystal Ball and TAPS, which covered 98% of the full solid angle. The main systematic uncertainty of the E asymmetry is related to the measurement of the beam and target polarizations. The uncertainty of the photon polarization degree was determined to be ±2.7%. The uncertainty of the target polarization was estimated as ±10%. Beam-target asymmetry E at W= 1.535 GeV

It is well known that reverberation mapping of active galactic nuclei (AGNs) reveals a relationship between AGN luminosity and the size of the broad-line region, and that use of this relationship, combined with the Doppler width of the broad emission line, enables an estimate of the mass of the black hole at the center of the active nucleus based on a single spectrum. An unresolved key issue is the choice of parameter used to characterize the line width, either FWHM or line dispersion {sigma}_line_ (the square root of the second moment of the line profile). We argue here that use of FWHM introduces a bias, stretching the mass scale such that high masses are overestimated and low masses are underestimated. Here we investigate estimation of black hole masses in AGNs based on individual or "single-epoch" observations, with a particular emphasis in comparing mass estimates based on line dispersion and FWHM. We confirm the recent findings that, in addition to luminosity and line width, a third parameter is required to obtain accurate masses, and that parameter seems to be Eddington ratio. We present simplified empirical formulae for estimating black hole masses from the H{beta} {lambda}4861 and C_IV_ {lambda}1549 emission lines. While the AGN continuum luminosity at 5100{AA} is usually used to predict the H{beta} reverberation lag, we show that the luminosity of the H{beta} broad component can be used instead without any loss of precision, thus eliminating the difficulty of accurately accounting for the host-galaxy contribution to the observed luminosity. Cone search capability for table J/ApJ/903/112/tablea3 (Reverberation-mapped AGNs (SDSS H{beta}))

A2 Collaboration at MAMI. High statistics angular distributions and total cross sections for the photoproduction of $\pi^0$ mesons off the deuteron with coincident detection of recoil nucleons have been measured for the first time. The experiment was performed at the tagged photon beam of the Mainz Microtron (MAMI) for photon energies between 0.45 and 1.4 GeV, using an almost 4$\pi$ electromagnetic calorimeter composed of the Crystal Ball and TAPS detectors. A complete kinematic reconstruction of the final state removed the effects of Fermi motion. Significant effects from final-state interactions (FSI) were observed for participant protons in comparison to free proton targets (between 30% and almost 40%). The data in coincidence with recoil neutrons were corrected for such effects under the assumption that they are identical for participant protons and neutrons. The total overall systematic uncertainty was estimated at 7%. Excitation function at cos(Theta_pi0)cm = -0.95

A2 Collaboration at MAMI. Precise helicity-dependent cross sections and the double-polarization observable E were measured for $\eta$ photoproduction from quasifree protons and neutrons bound in the deuteron. The $2\gamma$ and $3\pi^0$ decay modes were used to optimize the statistical quality of the data and to estimate systematic uncertainties. The measurement used the A2 detector setup at the tagged photon beam of the electron accelerator MAMI in Mainz. A longitudinally polarized deuterated butanol target was used in combination with a circularly polarized photon beam from bremsstrahlung of a longitudinally polarized electron beam. The reaction products were detected with the electromagnetic calorimeters Crystal Ball and TAPS, which covered 98% of the full solid angle. The main systematic uncertainty of the E asymmetry is related to the measurement of the beam and target polarizations. The uncertainty of the photon polarization degree was determined to be ±2.7%. The uncertainty of the target polarization was estimated as ±10%. Beam-target asymmetry E at W= 1.637 GeV