V. Polychronakos
A5036466409- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Radiation Detection and Scintillator Technologies
- Neutrino Physics Research
- Cosmology and Gravitation Theories
- Nuclear physics research studies
- Muon and positron interactions and applications
- Medical Imaging Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Astrophysics and Cosmic Phenomena
- Distributed and Parallel Computing Systems
- Nuclear reactor physics and engineering
- Atomic and Subatomic Physics Research
- CCD and CMOS Imaging Sensors
- Superconducting Materials and Applications
- Nuclear Physics and Applications
- Advanced NMR Techniques and Applications
- Atomic and Molecular Physics
- Advanced Data Storage Technologies
- advanced mathematical theories
- Particle accelerators and beam dynamics
Brookhaven National Laboratory
2015-2024
Brandeis University
2023-2024
A. Alikhanyan National Laboratory
2024
The University of Adelaide
2022-2023
University of Birmingham
2020
Azerbaijan National Academy of Sciences
2011
Associated Universities, Inc.
2002
Los Alamos National Laboratory
1994-2001
Mitchell Institute
1992-1999
Lund University
1999
Transverse mass spectra of pions, kaons, and protons from the symmetric heavy-ion collisions 200 $A$ GeV $\mathrm{S}+\mathrm{S}$ 158 $\mathrm{Pb}+\mathrm{Pb}$, measured in NA44 focusing spectrometer at CERN, are presented. The dependence slope parameters provides evidence collective transverse flow expansion system induced central collisions.
Data are presented on the inclusive production of ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, ${K}^{\ifmmode\pm\else\textpm\fi{}}$, $p$, and $\overline{p}$ for ${\ensuremath{\pi}}^{+}$, ${K}^{+}$, protons incident nuclear targets at 100 GeV. The results cover kinematic range $30\ensuremath{\le}P\ensuremath{\le}88$ GeV/c ${P}_{t}=0.3 \mathrm{and} 0.5$ GeV/c. observed $A$ dependence invariant cross sections exhibits remarkable simplicity, which does not naturally follow from current...
An experiment using the Fermilab Single Arm Spectrometer (SAS) facility and an associated nonmagnetic vertex detector studied reactions a+p→c+X, where a c were π±, K±, p, or p¯. Extensive measurements made at 100 175 GeV/c beam momenta with outgoing hadrons detected in SAS covering kinematic range 0.12<x<1.0 pT<1.25 GeV/c. Additional data more restricted x also gathered 70 incident momentum. In this high-statistics experiment, identification of both incoming charged total eight Čerenkov...
We have carried out an amplitude analysis of the ${K}_{S}^{0}{K}_{S}^{0}$ system produced in reaction ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{K}_{S}^{0}{K}_{S}^{0}n$ at 23 GeV/c, based on about 15 000 events low-$t$ region ($|t\ensuremath{-}{t}_{min}|<0.1$ Ge${\mathrm{V}}^{2}$). Below 1.6 GeV/${\mathit{c}}^{2}$, our favored solution is very similar to those from previous analyses. For higher masses, we observe decay $h(2040)$ meson. In addition, $l=0$ partial wave...
We present VMM1, the first prototype of a family front-end ASICs designed for ATLAS muon upgrade. The ASIC will operate with MICROMEGAS and TGC detectors, providing charge timing measurements along other features including sub-hysteresis discrimination, address event in real time, digital output per channel Time-over-Threshold measurements. shaper, via concept Delayed Dissipative Feedback (DDF), supports analog dynamic ranges excess 10 \thinspace000. With capacitance 200 pF nominal peaking...
The authors have detected 1203 events of the reaction ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}\ensuremath{\phi}\ensuremath{\phi}n$ at 22 GeV/c, and performed a partial-wave analysis $\ensuremath{\phi}\ensuremath{\phi}$ system. results are well represented by two resonances, both with quantum numbers ${I}^{G}={0}^{+}$, ${J}^{\mathrm{PC}}={2}^{++}$. breakdown Okubo-Zweig-Iizuka suppression observed in this is naturally explained context QCD if these states considered to be...
We have performed a high-sensitivity search for massive long-lived particles produced at 2.5 mrad by 400-GeV/c protons on beryllium target using time-of-flight, Cherenkov, and calorimetric techniques. A total of ${10}^{11}$ light (${\ensuremath{\pi}}^{\ensuremath{-}},{K}^{\ensuremath{-}},\overline{p}$) was sampled 70 GeV/c. This experiment places limit 1.1\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}37}$ ${\mathrm{cm}}^{2}$/${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$...
First results of the ${m}_{T}$ dependence ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}$ and ${K}^{+}{K}^{+}$ correlations from $\mathrm{S}+\mathrm{Pb}$ collisions at 200 GeV $/c$ per nucleon measured by focusing spectrometer NA44 experiment CERN are presented. Multidimensional fits characterize pion kaon emission volume. The radius parameter decreases with increasing ${p}_{T}$. Furthermore, radii show a common $1/\sqrt{{m}_{T}}$ dependence. This behavior can be interpreted as result strong...
Collisions of $^{28}\mathrm{Si}$+Al, Cu, Pb at ${\mathit{E}}_{\mathrm{lab}}$/A=14.6 GeV were studied in a calorimetry-based experiment the BNL Alternating Gradient Synchrotron. Transverse-energy production was measured for pseudorapidities -0.50.8. Correlations with spectra and multiplicity neutrons protons emitted into forward 0.8\ifmmode^\circ\else\textdegree\fi{} cone demonstrate quantitatively large amount nuclear stopping observed these reactions. Calculations hadronic-fireball or...
The VMM3a is a custom low-noise application-specific integrated circuit. It intended to be used in the front-end readout electronics of both Micromegas and sTGC detectors ATLAS New Small Wheels upgrade project at CERN. fabricated 130-nm GlobalFoundries 8RF-DM process. 64 channels with highly configurable parameters, although designed for specific project, can meet processing needs signals from various detector types several other applications. In this note, VMM3a, which production version...
Two-pion correlations from Pb+Pb collisions at 158 GeV/c per nucleon are measured by the NA44 experiment CERN. Multidimensional fits characterize emission volume, which is found to be larger than in S-induced collisions. Comparison RQMD model used relate fit parameters actual volume.Received 5 May 1998DOI:https://doi.org/10.1103/PhysRevC.58.1656©1998 American Physical Society
We present evidence for the existence of two new $I=0$ scalar mesons [${g}_{s}(1240)$ and ${S}^{*\ensuremath{'}}(1730)$] from an amplitude analysis reaction ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{K}_{S}^{0}{K}_{S}^{0}n$ at 23 GeV/c. An examination mass splittings shows that neither these states can be easily assigned to a (near) ideally mixed ${J}^{\mathrm{PC}}={0}^{++}$ nonet. These results are in qualitative agreement with recent theoretical predictions glucon-glucon...
We have observed the production of a new scalar meson mass 1255 \ifmmode\pm\else\textpm\fi{} 5 MeV and width 79 10 MeV. The is primarily through interference $S$-wave $D$-wave ${{K}_{s}}^{0}{{K}_{s}}^{0}$ amplitudes in reaction ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}n{{K}_{s}}^{0}{{K}_{s}}^{0}$ at 6 7 GeV/c. amplitude phase are both to Breit-Wigner behavior. quantum numbers ${J}^{P}={0}^{+}$ $C=+1$ with ${I}^{G}={1}^{\ensuremath{-}}$ preferred.
The NA44 experiment has measured single-particle inclusive spectra for charged pions, kaons, and protons as a function of transverse mass near midrapidity in 158AGeV/c Pb+Pb collisions. From the particle dependence observed mT distributions, we are able to deduce value about 120 MeV temperature at thermal freeze-out. ratios rapidity densities, find values chemical potentials light strange quarks freeze-out approximately 140 MeV.Received 20 February...
We have searched for the decay process ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{A}^{0}$, where ${A}^{0}$ is any particle of mass less than 100 MeV/${\mathit{c}}^{2}$ decaying into ${e}^{+}{e}^{\ensuremath{-}}$. Upper limits branching ratio are given as a function and lifetime ${A}^{0}$. For lifetimes shorter ${10}^{\ensuremath{-}13}$ sec, limit 4.5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}7}$ at 90% confidence level obtained.
Proton distributions at mid-rapidity (2 ≤ y 3) have been measured for 158A·GeV Pb+Pb collisions in the focusing spectrometer experiment NA44 CERN. From baryon number conservation and by comparing experimentally dNdy distribution with transport model RQMD, we conclude that a rather high degree of nuclear stopping has reached truly heavy-ion these energies. Transverse mass exhibit characteristically thermal shapes slope parameters increase colliding system.