A. Marušić
A5086336272- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Superconducting Materials and Applications
- Nuclear physics research studies
- Magnetic confinement fusion research
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Advanced NMR Techniques and Applications
- Medical Imaging Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- Laser-Plasma Interactions and Diagnostics
- Gyrotron and Vacuum Electronics Research
- Neutrino Physics Research
- Advanced Electrical Measurement Techniques
- Computational Physics and Python Applications
- Dark Matter and Cosmic Phenomena
- Marine and environmental studies
- Lubricants and Their Additives
- Advanced Data Storage Technologies
- Radiation Effects in Electronics
- VLSI and FPGA Design Techniques
Brookhaven National Laboratory
2013-2023
Indiana University Bloomington
2013
University of California, Los Angeles
2000-2010
University of Regina
2009
RIKEN BNL Research Center
2007
UCLA Health
2001
Rudjer Boskovic Institute
1992-2000
We present measurements of the differential and total cross sections Λ polarization for reaction K−p→ηΛ from threshold to pK−=770MeV/c, with much better precision than previous measurements. Our cross-section data show a remarkable similarity SU(3) flavor-related π−p→ηn results. The at is dominated by formation intermediate Λ(1670)12− state.Received 31 May 2001DOI:https://doi.org/10.1103/PhysRevC.64.055205©2001 American Physical Society
Reaction K−p→π0π0Σ0 was measured with the Crystal Ball multiphoton spectrometer at eight K− momenta from 514 to 750MeV∕c. Dynamics and energy dependence of reaction are shown by Dalitz plots, invariant mass spectra, production angular distributions, total cross sections. The dipion invariant-mass spectra for show an enhancement in low region; opposite is case K−p→π0π0Λ π−p→π0π0n reactions. There no direct evidence a f0(600)-meson contribution π0π0 production. Everywhere...
Cooling of beams gold ions using electron bunches accelerated with radio-frequency systems was recently experimentally demonstrated in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. Such an approach is new and opens possibility this technique higher energies than possible electrostatic acceleration beams. The challenges include generation suitable for cooling, delivery required quality to cooling sections without degradation beam angular divergence energy spread,...
We report on an investigation of the (pi(-),pi(0)pi(0)) reaction by means measurements pi(0)pi(0) invariant mass distributions from pi(-) interactions H, D, C, Al, and Cu targets at p(pi(-)) = 0.408 GeV/c. The sharp, strong peak in pi(+)pi(-) near 2m(pi) reported CHAOS Collaboration is not seen our data. However, we do observe a change shape spectrum for different targets, indicating that interaction diminishes nuclear medium as represented nuclei Cu, compared to hydrogen.
We have determined the quadratic slope parameter alpha for eta-->3pi(0) to be = -0.031(4) from a 99% pure sample of 10(6)eta-->3pi(0) decays produced in reaction pi(-)p-->n(eta) close eta threshold using Crystal Ball detector at AGS. The result is four times more precise than present world data and disagrees with current chiral perturbation theory calculations by about standard deviations.
Reaction π−p→π0π0n has been measured with high statistics in the beam momentum range 270–750MeV∕c. The data were obtained using Crystal Ball multiphoton spectrometer, which 93% of 4π solid angle coverage. dynamics reaction and dependence on energy are displayed total cross sections, Dalitz plots, invariant-mass spectra, production angular distributions. Special attention is paid to evaluation acceptance that needed for precision determination section σt(π−p→π0π0n). σt(π−p→π0π0n) shows a...
Head-on beam-beam compensation has been implemented in the Relativistic Heavy Ion Collider order to increase luminosity delivered experiments. We discuss principle of combining a lattice for resonance driving term and an electron lens tune spread compensation. describe technology its operational use. To date, scheme approximately doubled peak average luminosities.
The differential cross section for \ensuremath{\eta} production in reaction ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}\ensuremath{\eta}n$ has been measured over the full angular range at seven incident ${\ensuremath{\pi}}^{\ensuremath{-}}$ beam momenta from threshold to ${p}_{{\ensuremath{\pi}}^{\ensuremath{-}}}=747$ MeV/c using Crystal Ball multiphoton spectrometer. distributions are S wave dominated. At 10 above threshold, a small D-wave contribution appears that...
Reaction K−p→π0π0Λ was measured at eight incident K− momenta between 514 and 750MeV/c using the Crystal Ball multiphoton spectrometer. The reaction dynamics are displayed in total cross sections, Dalitz plots, invariant-mass spectra, production angular distributions, Λ polarization. π0π0Λ is dominated by π0Σ0(1385) intermediate state; no trace of other light Σ∗ states observed, role f0(600) meson appears to be insignificant. A striking similarity seen π−p→π0π0n; this can understood as a...
New results on the rare, doubly radiative decay η→π0γγ have been obtained from a revised analysis of Crystal Ball experiment performed at AGS. The yields first information dependence width, Γ(η→π0γγ), two-photon invariant mass squared, m2(γγ). A re-evaluation branching ratio is also made, BR(η→π0γγ)=(2.21±0.24stat±0.47syst)×10−4; it implies that width Γ(η→π0γγ)=0.285±0.031stat±0.061syst eV. These are close to predictions based chiral perturbation theory with vector-meson dominance.1...
Differential cross sections and hyperon polarizations have been measured for ${\overline{K}}^{0}n$, ${\ensuremath{\pi}}^{0}\ensuremath{\Lambda}$, ${\ensuremath{\pi}}^{0}{\ensuremath{\Sigma}}^{0}$ production in ${K}^{\ensuremath{-}}p$ interactions at eight ${K}^{\ensuremath{-}}$ momenta between 514 750 MeV/$c$. The experiment detected the multiphoton final states with Crystal Ball spectrometer using a beam from BNL Alternating Gradient Synchrotron. results provide significantly greater...
Correction of beta-beat is great importance for performance improvement high energy accelerators, like the Relativistic Hadron Ion Collider (RHIC). At RHIC, using independent component analysis method, linear optical functions are extracted from turn by beam position data ac dipole driven betatron oscillation. Despite constraint a limited number available quadrupole correctors at global correction scheme response matrix method was developed and experimentally demonstrated. In both rings,...
In polarized proton collision experiments, it is highly advantageous to flip the spin of each bunch protons during stores reduce systematic errors. Experiments done at energies less than 2 GeV have demonstrated a spin-flip efficiency over 99%. At high energy colliders with Siberian snakes, single magnet flipper does not work because large tune spread and generation multiple, overlapping resonances. A more sophisticated flipper, constructed nine-dipole magnets, was used in BNL Relativistic...
A hollow electron beam has been proposed as an active control tool to remove the halo from high-energy, high-current hadron or ion machines (such High-Luminosity Large Hadron Collider). To study removal rate and assess effect on core, one of two lenses in Relativistic Heavy Ion Collider was changed a Gaussian profile profile. We describe design verification parameters well methods minimize distortions, which can result emittance increase. The alignment with by using backscattered detector...
We report a measurement of charge symmetry breaking in the NNη system. have measured ratio differential cross sections charge-symmetric reactions π+d→ppη and π−d→nnη energy region η threshold. Our result is R≡dσ(π+d→ppη)/dσ(π−d→nnη)=0.938±0.009 after phase-space correction made for difference threshold energies two reactions. The deviation R from unity an indication breaking, which mostly due to π0−η mixing. A theoretical model production includes mixing was used fit data yields angle...
Differential cross sections for the process π−p→γn have been measured at Brookhaven National Laboratory's Alternating Gradient Synchrotron with Crystal Ball multiphoton spectrometer. Measurements were made 18 pion momenta from 238 to 748MeV∕c, corresponding Eγ inverse reaction 285 769MeV. The data used evaluate γn multipoles in vicinity of N(1440) resonance. We compare our and previous determinations.1 MoreReceived 6 May 2004DOI:https://doi.org/10.1103/PhysRevC.70.035204©2004 American...
Measured values of the differential cross section for pion-nucleon charge exchange, ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}n$, are presented at ${\ensuremath{\pi}}^{\ensuremath{-}}$ momenta 148, 174, 188, 212, 238, 271, 298, and $323\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}∕c$, a region dominated by $\ensuremath{\Delta}(1232)$ resonance. Complete angular distributions were obtained using Crystal Ball detector Alternating Gradient Synchrotron (AGS)...
Two electron lenses ($e$-lenses) have been in operation during the 2015 RHIC physics run as part of a head-on beam-beam compensation scheme. While lattice was chosen to reduce beam-beam-induced resonance-driving terms, reduced tune spread. This has demonstrated for first time. The scheme allows higher parameters and therefore intensities luminosity. In this paper, we detail design considerations verification beam $e$-lenses. Longitudinal transverse alignments with ion beams transfer function...
Deuteron and gold beams have been accelerated to a collision energy of /spl radic/s = 200 GeV/u in the Relativistic Heavy Ion Collider (RHIC), providing first asymmetric-species collisions this complex. Necessary changes for mode operation include new ramping software asymmetric crossing angle geometries. This paper reviews machine performance, problems encountered their solutions, accomplishments during 16 weeks ramp-up operations.
During the RHIC 2000 run a prototype PLL tune measurement system was implemented using commercial off-the-shelf hardware. To meet requirements for feedback during 2001/2002, this migrated into BPM modules, whose flexible DSP/FPGA architecture permitted specialized processing needed tracking and acceleration, existing firewire interface provided communication with Control System. For 2003 has yet again, to state-of-the-art DSPs in VME. We report here on various improvements, extending from...
The branching ratio (BR) for the rare decay $\ensuremath{\eta}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}\ensuremath{\gamma}\ensuremath{\gamma}$ was measured with Crystal Ball multiphoton spectrometer. result, BR$(\ensuremath{\eta}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}\ensuremath{\gamma}\ensuremath{\gamma})=(3.5\ifmmode\pm\else\textpm\fi{}0.{7}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}0.{6}_{\mathrm{syst}})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$, is in...
Preliminary phase-locked loop betatron tune measurement results were obtained during RHIC 2000 with a resonant Beam Position Monitor. These suggested the possibility of incorporating PLL into feedback system for 2001. Tune is useful in superconducting accelerator, where machine cycle time long and inefficient acceleration due to resonance crossing not comfortably tolerated. This particularly true higher beam intensities planned We present descriptions implemented DSP/FPGA environment BPM...
Simultaneous tune and coupling feedback were successfully implemented during RHIC run 6. In this paper we describe the measurement control hardware software used to accomplish this, present some of results, discuss areas that require further investigation, finally offer a few comments on possible implications these results for LHC commissioning.