H. Hakobyan
A5066790249- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Nuclear physics research studies
- Cosmology and Gravitation Theories
- Neutrino Physics Research
- Computational Physics and Python Applications
- Astrophysics and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- Medical Imaging Techniques and Applications
- Black Holes and Theoretical Physics
- Quantum, superfluid, helium dynamics
- Distributed and Parallel Computing Systems
- Advanced NMR Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- advanced mathematical theories
- Muon and positron interactions and applications
- Atomic and Molecular Physics
- Cold Atom Physics and Bose-Einstein Condensates
- Gamma-ray bursts and supernovae
Universidad Técnica Federico Santa María
2024-2025
Federico Santa María Technical University
2015-2024
Thomas Jefferson National Accelerator Facility
2008-2024
Centro Científico Tecnológico de Valparaíso
2017-2024
University of California, Riverside
2024
A. Alikhanyan National Laboratory
2014-2023
Duquesne University
2020-2023
University of York
2020-2023
University of Insubria
2022
The University of Adelaide
2013-2020
This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on structure and interactions gluon-dominated matter, with intent to articulate it broader nuclear community. It was commissioned by managements Brookhaven National Laboratory (BNL) Thomas Jefferson Accelerator Facility (JLab) objective presenting a summary scientific opportunities goals EIC as follow-up 2007 NSAC Long Range plan. document is culmination community-wide effort in following series workshops...
A new general purpose fixed target facility is proposed at the CERN SPS accelerator which aimed exploring domain of hidden particles and make measurements with tau neutrinos. Hidden are predicted by a large number models beyond Standard Model. The high intensity 400~GeV beam allows probing wide variety containing light long-lived exotic masses below ${\cal O}$(10)~GeV/c$^2$, including very weakly interacting low-energy SUSY states. experimental programme capable being extended in future,...
The atomic nucleus is composed of two different kinds fermions, protons and neutrons. If the neutrons did not interact, Pauli exclusion principle would force majority fermions (usually neutrons) to have a higher average momentum. Our high-energy electron scattering measurements using 12C, 27Al, 56Fe 208Pb targets show that, even in heavy neutron-rich nuclei, short-range interactions between form correlated high-momentum neutron-proton pairs. Thus, greater probability than momentum Fermi This...
We report on the measurement of γp→J/ψp cross section from E_{γ}=11.8 GeV down to threshold at 8.2 using a tagged photon beam with GlueX experiment. find that total falls toward less steeply than expected two-gluon exchange models. The differential dσ/dt has an exponential slope 1.67±0.39 GeV^{-2} 10.7 average energy. LHCb pentaquark candidates P_{c}^{+} can be produced in s channel this reaction. see no evidence for them and set model-dependent upper limits their branching fractions...
We present results on the electroexcitation of low mass resonances Delta(1232)P33, N(1440)P11, N(1520)D13, and N(1535)S11 in a wide range Q2. The were obtained comprehensive analysis JLab-CLAS data differential cross sections, longitudinally polarized beam asymmetries, longitudinal target beam-target asymmetries for pion electroproduction off proton. analysed using two conceptually different approaches, fixed-t dispersion relations unitary isobar model, allowing us to draw conclusions model...
This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on structure and interactions gluon-dominated matter, with intent to articulate it broader nuclear community. It was commissioned by managements Brookhaven National Laboratory (BNL) Thomas Jefferson Accelerator Facility (JLab) objective presenting a summary scientific opportunities goals EIC as follow-up 2007 NSAC Long Range plan. document is culmination community-wide effort in following series workshops...
The beam-spin asymmetries in the hard exclusive electroproduction of photons on proton ($\stackrel{\ensuremath{\rightarrow}}{e}p\ensuremath{\rightarrow}ep\ensuremath{\gamma}$) were measured over a wide kinematic range and with high statistical accuracy. These result from interference Bethe-Heitler process deeply virtual Compton scattering. Over whole (${x}_{B}$ 0.11 to 0.58, ${Q}^{2}$ 1 $4.8\text{ }\text{ }{\mathrm{GeV}}^{2}$, $\ensuremath{-}t$ 0.09 $1.8\text{ }{\mathrm{GeV}}^{2}$),...
Interaction cross sections and charged pion spectra in p+C interactions at 31 GeV/c were measured with the large acceptance NA61/SHINE spectrometer CERN SPS. These data are required to improve predictions of neutrino flux for T2K long baseline oscillation experiment Japan. A set collected during first run 2007 an isotropic graphite target a thickness 4% nuclear interaction length was used analysis. The inelastic production 257.2 +- 1.9 8.9 mb 229.3 9.0 mb, respectively. Inclusive negatively...
Spin transfer from circularly polarized real photons to recoiling hyperons has been measured for the reactions $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\gamma}}+p\ensuremath{\rightarrow}{K}^{+}+\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\Lambda}}$ and $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\gamma}}+p\ensuremath{\rightarrow}{K}^{+}+{\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\Sigma}}}^{0}$. The data were obtained using CEBAF Large Acceptance Spectrometer (CLAS)...
The reaction gamma + p -> K+ Sigma pi was used to determine the invariant mass distributions or "line shapes" of Sigma+ pi-, Sigma- pi+ and Sigma0 pi0 final states, from threshold at 1328 MeV/c^2 through range Lambda(1405) Lambda(1520). measurements were made with CLAS system Jefferson Lab using tagged real photons, for center-of-mass energies 1.95 < W 2.85 GeV. three differ strongly in vicinity I=0 \Lambda(1405), indicating presence substantial I=1 strength reaction. Background...
The transition helicity amplitudes from the proton ground state to $P_{11}(1440)$ and $D_{13}(1520)$ excited states ($\gamma_{v}pN^*$ electrocouplings) were determined analysis of nine independent one-fold differential $\pi^{+} \pi^{-} p$ electroproduction cross sections off a target, taken with CLAS at photon virtualities 0.25\enskip {\rm GeV$^{2}$} $<$ $Q^{2}$ 0.60 \enskip GeV$^{2}$}. phenomenological reaction model was employed for separation resonant non-resonant contributions final...
We measured the triple coincidence A(e,e'np) and A(e,e'pp) reactions on carbon, aluminum, iron, lead targets at Q2 > 1.5 (GeV/c)2, xB 1.1 missing momentum 400 MeV/c. This was first direct measurement of both proton-proton (pp) neutron-proton (np) short-range correlated (SRC) pair knockout from heavy asymmetric nuclei. For all nuclei, average to reduced cross-section ratio is about 6%, in agreement with previous indirect measurements. Correcting for Single-Charge Exchange effects decreased...
Unpolarized and beam-polarized fourfold cross sections (d^{4}σ/dQ^{2}dx_{B}dtdϕ) for the ep→e^{'}p^{'}γ reaction were measured using CLAS detector 5.75-GeV polarized electron beam of Jefferson Lab accelerator, 110 (Q^{2},x_{B},t) bins over widest phase space ever explored in valence-quark region. Several models generalized parton distributions (GPDs) describe data well at most our kinematics. This increases confidence that we understand GPD H, expected to be dominant contributor these...
We report the total and differential cross sections for $J/\psi$ photoproduction with large acceptance GlueX spectrometer photon beam energies from threshold at 8.2~GeV up to 11.44~GeV over full kinematic range of momentum transfer squared, $t$. Such coverage facilitates extrapolation forward ($t = 0$) point beyond physical region. The section is used by many theoretical models plays an important role in understanding its relation $J/\psi-$proton interaction. These measurements near are also...
We report test beam studies of 11% the production ATLAS Tile Calorimeter modules. The modules were equipped with front-end electronics and all calibration systems planned for final detector. used muon, electron hadron beams ranging in energy from 3 to 350 GeV. Two independent showed that light yield calorimeter was ∼70pe/GeV, exceeding design goal by 40%. Electron provided a at electromagnetic scale. Over 200 cells variation response 2.4%. linearity also measured. Muon an intercalibration...
Differential cross sections for the reaction $\gamma p \to n \pi^+$ have been measured with CEBAF Large Acceptance Spectrometer (CLAS) and a tagged photon beam energies from 0.725 to 2.875 GeV. Where available, results obtained here compare well previously published reaction. Agreement SAID MAID analyses is found below 1 The present set of has incorporated into database, exploratory fits made up 2.7 Resonance couplings extracted compared previous determinations. With addition these world...
High-statistics differential cross sections for the reactions $\ensuremath{\gamma}p\ensuremath{\rightarrow}p\ensuremath{\eta}$ and $\ensuremath{\gamma}p\ensuremath{\rightarrow}p{\ensuremath{\eta}}^{'}$ have been measured using CEBAF large acceptance spectrometer (CLAS) at Jefferson Lab center-of-mass energies from near threshold up to 2.84 GeV. The ${\ensuremath{\eta}}^{'}$ results are most precise date provide largest energy angular coverage. $\ensuremath{\eta}$ measurements extend range of...
Spectra of positively charged kaons in p+C interactions at 31 GeV/c were measured with the NA61/SHINE spectrometer CERN SPS. The analysis is based on full set data collected 2007 a graphite target thickness 4% nuclear interaction length. Interaction cross sections and pion spectra already using same data. These new measurements combination published ones are required to improve predictions neutrino flux for T2K long baseline oscillation experiment Japan. In particular, knowledge kaon...
We report the first measurement of transverse momentum dependence double-spin asymmetries in semi-inclusive production pions deep-inelastic scattering off longitudinally polarized proton. Data have been obtained using a electron beam 5.7 GeV with CLAS detector at Jefferson Lab (JLab). Modulations single spin over azimuthal angle between lepton and hadron planes ϕ measured wide kinematic range Bjorken x virtual photon squared four-momentum Q2. A significant nonzero sin2ϕ asymmetry was...
We report the exclusive photoproduction cross sections for Sigma(1385), Lambda(1405), and Lambda(1520) in reactions gamma + p -> K+ Y* using CLAS detector energies from near respective production thresholds up to a center-of-mass energy W of 2.85 GeV. The differential are integrated give total each hyperon. Comparisons made current theoretical models based on effective Lagrangian approach fitted previous data. accuracy these is seen vary widely. Lambda(1405) region strikingly different...
Much less is known about neutron structure than that of the proton due to absence free targets. Neutron information usually extracted from data on nuclear targets such as deuterium, requiring corrections for binding and nucleon off-shell effects. These are model dependent have significant uncertainties, especially large values Bjorken scaling variable x. The Barely Off-shell Nucleon Structure (BONuS) experiment at Jefferson Lab measured inelastic electron deuteron scattering cross section,...