V. L. Kashevarov
A5085361168- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- Nuclear physics research studies
- High-Energy Particle Collisions Research
- Atomic and Subatomic Physics Research
- Advanced NMR Techniques and Applications
- Superconducting Materials and Applications
- Nuclear Physics and Applications
- Quantum, superfluid, helium dynamics
- Radiation Detection and Scintillator Technologies
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Atomic and Molecular Physics
- Quantum chaos and dynamical systems
- Medical Imaging Techniques and Applications
- Crystallography and Radiation Phenomena
- Physics of Superconductivity and Magnetism
- Advanced Chemical Physics Studies
- Computational Physics and Python Applications
- Scientific Research and Discoveries
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Advanced Semiconductor Detectors and Materials
- Machine Learning and Data Classification
- Radiation Therapy and Dosimetry
Johannes Gutenberg University Mainz
2015-2024
Joint Institute for Nuclear Research
2018-2024
Max Planck Institute for Nuclear Physics
2024
P.N. Lebedev Physical Institute of the Russian Academy of Sciences
2011-2023
Universidad de Salamanca
2018
Russian Academy of Sciences
2013-2015
Crystal Research (United States)
2011
Information on the size and shape of neutron skin (208)Pb is extracted from coherent pion photoproduction cross sections measured using Crystal Ball detector together with Glasgow tagger at MAMI electron beam facility. On exploitation an interpolated fit a theoretical model to sections, half-height radius diffuseness distribution are found be c(n)=6.70±0.03(stat.) fm a(n)=0.55±0.01(stat.)(-0.03)(+0.02)(sys.) fm, respectively, corresponding thickness...
The photoproduction of η-mesic 3He has been investigated using the TAPS calorimeter at Mainz Microtron accelerator facility MAMI. total inclusive cross section for reaction γ3He→ηX measured photon energies from threshold to 820 MeV. and angular differential coherent η sections have extracted up 745 A resonancelike structure just above production with an isotropic distribution suggests existence a resonant quasibound state. This is supported by studies competing decay channel such nucleus...
The gp-->etap reaction has been measured with the Crystal Ball and TAPS multiphoton spectrometers in energy range from production threshold of 707 MeV to 1.4 GeV (1.49 =< W >= 1.87 GeV). Bremsstrahlung photons produced by 1.5-GeV electron beam Mainz Microtron MAMI-C momentum analyzed Glasgow Tagging Spectrometer were used for eta-meson production. Our accumulation 3.8 x 10^6 gp-->etap-->3pi0p-->6gp events allows a detailed study dynamics. differential cross sections determined 120 bins full...
The dynamics of the $\eta\to 3\pi^0$ decay have been studied with Crystal Ball multiphoton spectrometer and TAPS calorimeter. Bremsstrahlung photons produced by 1.5-GeV electron beam Mainz microtron MAMI-C tagged Glasgow photon were used for $\eta$-meson production. analysis $3 \times 10^6$ $\gamma p \to \eta 3\pi^0 6\gamma p$ events yields value $\alpha=-0.032\pm0.003$ slope parameter, which agrees majority recent experimental results has smallest uncertainty. $\pi^0\pi^0$ invariant-mass...
Measurements of $γp \rightarrow K^{+} Λ$ and Σ^0$ cross-sections have been obtained with the photon tagging facility Crystal Ball calorimeter at MAMI-C. The measurement uses a novel $K^+$ meson identification technique in which weak decay products are characterized using energy timing characteristics deposit calorimeter, method that has potential to be applied many other facilities. fine center-of-mass ($W$) resolution statistical accuracy new data results significant impact on partial wave...
Differential and total cross sections for the quasifree reactions $\gamma p\rightarrow\eta p$ n\rightarrow\eta n$ have been determined at MAMI-C electron accelerator using a liquid deuterium target. Photons were produced via bremsstrahlung from 1.5 GeV incident beam energy-tagged with Glasgow photon tagger. Decay photons of neutral decay modes $\eta\rightarrow 2\gamma$ 3\pi^0 \rightarrow 6\gamma$ coincident recoil nucleons detected in combined setup Crystal Ball TAPS calorimeters. The...
An experimental study of $\omega$ photoproduction on the proton was conducted by using Crystal Ball and TAPS multiphoton spectrometers together with photon tagging facility at Mainz Microtron MAMI. The $\gamma p\to\omega p$ differential cross sections are measured from threshold to incident-photon energy $E_\gamma=1.40$ GeV ($W=1.87$ for center-of-mass energy) 15-MeV binning in $E_\gamma$ full production-angle coverage. quality present data near gives access a variety interesting physics...
The reactions γp→ηp and γp→η^{'}p are measured from their thresholds up to the center-of-mass energy W=1.96 GeV with tagged-photon facilities at Mainz Microtron, MAMI. Differential cross sections obtained unprecedented statistical accuracy, providing fine binning full production-angle coverage. A strong cusp is observed in total section for η photoproduction energies vicinity of η^{'} threshold, W=1896 MeV (E_{γ}=1447 MeV). Within framework a revised ηMAID isobar model, cusp, connection...
The photoproduction of η mesons off nucleons bound in 2H and 3He has been measured coincidence with recoil protons neutrons for incident photon energies from threshold up to 1.4 GeV. experiments were performed at the Mainz MAMI accelerator, using Glasgow tagged facility. Decay photons η→2γ η→3π0 decays detected an almost 4π electromagnetic calorimeter combining Crystal Ball TAPS detectors. data both targets are excellent statistical quality show a narrow structure excitation function γn→nη....
The Dalitz decay $\ensuremath{\eta}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}\ensuremath{\gamma}$ has been measured in the $\ensuremath{\gamma}p\ensuremath{\rightarrow}\ensuremath{\eta}p$ reaction with Crystal Ball and TAPS multiphoton spectrometers, together photon-tagging facility at Mainz Microtron MAMI. experimental statistic used this work is one order of magnitude greater than any previous measurement...
The Dalitz decays eta -> e^+e^-g and omega pi^0 e^+e^- have been measured in the g p reactions, respectively, with A2 tagged-photon facility at Mainz Microtron, MAMI. value obtained for slope parameter of electromagnetic transition form factor eta, Lambda^{-2}_eta=(1.97+/-0.11_tot) GeV^{-2}, is good agreement previous measurements mu^+mu^-g decays. uncertainty Lambda^{-2}_eta lower than results based on decay. parameter, Lambda^{-2}_omega_pi^0 = (1.99+/-0.21_tot) somewhat mu^+mu^-, but are...
The spin polarizabilities of the nucleon describe how responds to an incident polarized photon. most model-independent way extract is through Compton scattering. Double-polarized scattering asymmetries on proton were measured in $\mathrm{\ensuremath{\Delta}}(1232)$ region using circularly photons and a transversely target at Mainz Microtron. Fits asymmetry data performed dispersion model calculation baryon chiral perturbation theory calculation, separation all four multipole basis was...
Differential cross sections for the gamma p -> pi^0 reaction have been measured with A2 tagged-photon facilities at Mainz Microtron, MAMI C, up to center-of-mass energy W=1.9 GeV. The new results, obtained a fine and angular binning, increase existing quantity of photoproduction data by ~47%. Owing unprecedented statistical accuracy full coverage, results are sensitive high partial-wave amplitudes. This is demonstrated decomposition differential in terms Legendre polynomials further...
We present new data for the transverse target asymmetry T and very first beam-target F in →γ→p→ηp reaction up to a center-of-mass energy of W=1.9 GeV. The were obtained with Crystal-Ball/TAPS detector setup at Glasgow tagged photon facility Mainz Microtron MAMI. All existing model predictions fail reproduce indicating significant impact on our understanding underlying dynamics η meson photoproduction. peculiar nodal structure observed close threshold is not confirmed.Received 12 June...
The gamma p --> pi0 reaction has been measured from threshold to 1.4 GeV using the Crystal Ball and TAPS photon spectrometers together with tagging facility at Mainz Microtron. experimental results include total differential cross sections as well specific angular distributions, which were used extract partial-wave amplitudes. In particular, energy region below D13(1520) resonance was studied.
A precision measurement of the differential cross sections dσ/dΩ and linearly polarized photon asymmetry Σ≡(dσ⊥-dσ∥)/(dσ⊥+dσ∥) for γp→π0p reaction in near-threshold region has been performed with a tagged beam almost 4π detector at Mainz Microtron. The Glasgow-Mainz tagging facility along Crystal Ball/TAPS multiphoton system cryogenic liquid hydrogen target were used. These data allowed precise determination energy dependence real parts S- all three P-wave amplitudes first time provide most...
Beam-helicity asymmetries have been measured at the MAMI accelerator in Mainz three isospin channels γ→p→π+π0n, γ→p→π0π0p, and γ→p→π+π−p. The circularly polarized photons, produced from bremsstrahlung of longitudinally electrons, were tagged with Glasgow magnetic spectrometer. Charged pions decay photons π0 mesons detected a 4π electromagnetic calorimeter which combined Crystal Ball detector TAPS detector. precisely are very sensitive to details production processes thus key observables...