0000000000998471
AUTHOR
R. Novotny
New determination of theηtransition form factor in the Dalitz decayη→e+e−γwith the Crystal Ball/TAPS detectors at the Mainz Microtron
The Dalitz decay eta -> e(+) e(-) gamma has been measured in the gamma p -> eta p reaction with the Crystal Ball and TAPS multiphoton spectrometers, together with the photon-tagging facility at the Mainz Microtron MAMI. The experimental statistic used in this work is one order of magnitude greater than in any previous measurement of eta -> e(+) e(-) gamma. The value obtained for the slope parameter Lambda(-2) of the eta transition form factor, Lambda(-2) = (1.95 +/- 0.15(stat) +/- 0.10(syst)) GeV-2, is in good agreement with recent measurements conducted in eta -> e(+) e(-) gamma and eta -> mu(+) mu(-) gamma decays, as well as with recent form-factor calculations. The uncertainty obtained i…
Photoproduction of π0-pairs off protons and off neutrons
Total cross sections, angular distributions, and invariant-mass distributions have been measured for the photoproduction of π0π0 pairs off free protons and off nucleons bound in the deuteron. The experiments were performed at the MAMI accelerator facility in Mainz using the Glasgow photon tagging spectrometer and the Crystal Ball/TAPS detector. The accelerator delivered electron beams of 1508 and 1557MeV, which produced bremsstrahlung in thin radiator foils. The tagged photon beam covered energies up to 1400MeV. The data from the free proton target are in good agreement with previous measurements and were only used to test the analysis procedures. The results for differential cross sections…
Measurement of the $^{1}H$($\vec{\gamma}$, $\vec{p}$)$\pi^{0}$ reaction using a novel nucleon spin polarimeter
We report the first large-acceptance measurement of polarization transfer from a polarized photon beam to a recoiling nucleon, pioneering a novel polarimetry technique with wide application to future nuclear and hadronic physics experiments. The commissioning measurement of polarization transfer in the $^{1}H$($\vec{\gamma}$,$\vec{p}$)$\pi^{0}$ reaction in the range $0.4<E_{\gamma}<1.4$ GeV is highly selective regarding the basic parameterizations used in partial wave analyses to extract the nucleon excitation spectrum. The new data strongly favor the recently proposed Chew-Mandelstam formalism.
Performance of the upgraded PreProcessor of the ATLAS Level-1 Calorimeter Trigger
The PreProcessor of the ATLAS Level-1 Calorimeter Trigger prepares the analogue trigger signals sent from the ATLAS calorimeters by digitising, synchronising, and calibrating them to reconstruct transverse energy deposits, which are then used in further processing to identify event features. During the first long shutdown of the LHC from 2013 to 2014, the central components of the PreProcessor, the Multichip Modules, were replaced by upgraded versions that feature modern ADC and FPGA technology to ensure optimal performance in the high pile-up environment of LHC Run 2. This paper describes the features of the newMultichip Modules along with the improvements to the signal processing achieved.
Study of doubly strange systems using stored antiprotons
Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the PANDA experiment at FAIR. For the first time, high resolution gamma-spectroscopy of doubly strange Lambda Lambda-hypernuclei will be performed, thus complementing measurements of ground state decays of Lambda Lambda-hypernuclei at J-PARC or possible …
Observation and Measurement of Forward Proton Scattering in Association with Lepton Pairs Produced via the Photon Fusion Mechanism at ATLAS
The observation of forward proton scattering in association with lepton pairs (eþe− þ p or μþμ− þ p) produced via photon fusion is presented. The scattered proton is detected by the ATLAS Forward Proton spectrometer, while the leptons are reconstructed by the central ATLAS detector. Proton-proton collision data recorded in 2017 at a center-of-mass energy of ffiffiffi s p ¼ 13 TeV are analyzed, corresponding to an integrated luminosity of 14.6 fb−1. A total of 57 (123) candidates in the ee þ p (μμ þ p) final state are selected, allowing the background-only hypothesis to be rejected with a significance exceeding 5 standard deviations in each channel. Proton-tagging techniques are introduced f…
Measurement of photon?jet transverse momentum correlations in 5.02 TeV Pb + Pb and pp collisions with ATLAS
Jets created in association with a photon can be used as a calibrated probe to study energy loss in the medium created in nuclear collisions. Measurements of the transverse momentum balance between isolated photons and inclusive jets are presented using integrated luminosities of 0.49 nb−1 of Pb + Pb collision data at TeV and 25 pb−1 of pp collision data at TeV recorded with the ATLAS detector at the LHC. Photons with transverse momentum GeV and are paired with all jets in the event that have GeV and pseudorapidity . The transverse momentum balance given by the jet-to-photon ratio, , is measured for pairs with azimuthal opening angle . Distributions of the per-photon jet yield as a function…
"Table 6" of "In-medium modifications of the pi pi interaction in photon-induced reactions."
Differential cross section for PI0PI+/- production with a Lead target. Errors are statistical only.
"dcs09" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.7891 GeV
"dcs02" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.7319 GeV
"Table 2" of "In-medium modifications of the pi pi interaction in photon-induced reactions."
Differential cross section for PI0PI0 production with a Carbon target. Errors are statistical only.
"Table 1" of "In-medium modifications of the pi pi interaction in photon-induced reactions."
Differential cross section for PI0PI0 production with a proton target. Errors are statistical only. Note that the data given in this table are sightly different (newer) than the data points presented in the paper.
"dcs13" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.8192 GeV
"Table 4" of "In-medium modifications of the pi pi interaction in photon-induced reactions."
Differential cross section for PI0PI+ production with a proton target. Errors are statistical only. Note that the data given in this table are sightly different (newer) than the data points presented in the paper.
"dcs04" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.7490 GeV
"dcs05" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.7568 GeV
"dcs19" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.8657 GeV
"Table 3" of "In-medium modifications of the pi pi interaction in photon-induced reactions."
Differential cross section for PI0PI0 production with a Lead target. Errors are statistical only.
"Table 1" of "Compton scattering from the free and bound proton at backward angles above pi threshold."
No description provided.
"dcs06" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.7645 GeV
"Table 1" of "Double pi0 photoproduction off the proton at threshold."
Total cross section measurement. Statistical errors only.
"dcs11" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.8045 GeV
"dcs12" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.8119 GeV
"Table 5" of "In-medium modifications of the pi pi interaction in photon-induced reactions."
Differential cross section for PI0PI+/- production with a Carbon target. Errors are statistical only.
"tcs" of "Photoproduction of the omega meson off the proton near threshold"
Total cross section as a function of c.m. energy W.
"dcs17" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.8504 GeV
"dcs01" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.7245 GeV
"dcs20" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.8720 GeV
"dcs18" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.8581 GeV
"dcs16" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.8424 GeV
"dcs07" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.7729 GeV
"dcs03" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.7401 GeV
"dcs14" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.8269 GeV
"dcs10" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.7968 GeV
"dcs08" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.7811 GeV
"dcs15" of "Photoproduction of the omega meson off the proton near threshold"
Differential cross section at W= 1.8348 GeV