A. Sidorov
A5014253762- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Particle Detector Development and Performance
- Astrophysics and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- Analytic Number Theory Research
- Benford’s Law and Fraud Detection
- Advanced X-ray and CT Imaging
- Stochastic processes and statistical mechanics
- Inorganic Fluorides and Related Compounds
- Radiation Effects and Dosimetry
- Particle Accelerators and Free-Electron Lasers
- Nuclear physics research studies
- European Politics and Security
- Atomic and Molecular Physics
- Medical Imaging Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Muon and positron interactions and applications
- Cosmology and Gravitation Theories
- Security, Politics, and Digital Transformation
Institute for High Energy Physics
2000-2024
Universidade de Santiago de Compostela
2014-2015
Lomonosov Moscow State University
2003-2009
Cyclotron (Netherlands)
2009
Joint Institute for Nuclear Research
1989-2007
University of Bern
2003-2005
Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering
2004
The goal of the DIRAC experiment at CERN (PS212) is to measure $\pi^+\pi^-$ atom lifetime with 10% precision. Such a measurement would yield precision 5% on value $S$-wave $\pi\pi$ scattering lengths combination $|a_0-a_2|$. Based part collected data we present first result lifetime, $\tau=[2.91 ^{+0.49}_{-0.62}]\times 10^{-15}$ s, and discuss major systematic errors. This corresponds $|a_0-a_2|=0.264 ^{+0.033}_{-0.020} m_{\pi}^{-1}$.
The DIRAC experiment at CERN has achieved a sizeable production of $\pi^+\pi^-$ atoms and significantly improved the precision on its lifetime determination. From sample 21227 atomic pairs, 4% measurement S-wave $\pi\pi$ scattering length difference $|a_0-a_2| = (.0.2533^{+0.0080}_{-0.0078}|_\mathrm{stat}.{}^{+0.0078}_{-0.0073}|_\mathrm{syst})M_{\pi^+}^{-1}$ been attained, providing an important test Chiral Perturbation Theory.
The results of a search for hydrogen-like atoms consisting $\pi^{\mp}K^{\pm}$ mesons are presented. Evidence $\pi K$ atom production by 24 GeV/c protons from CERN PS interacting with nickel target has been seen in terms characteristic pairs their breakup the same ($178 \pm 49$) and Coulomb final state interaction ($653 42$). Using these analysis yields first value lifetime $\tau=(2.5_{-1.8}^{+3.0})$ fs model-independent measurement S-wave isospin-odd scattering length...
The observation of hydrogenlike πK atoms, consisting π^{-}K^{+} or π^{+}K^{-} mesons, is presented. atoms are produced by 24 GeV/c protons from the CERN PS accelerator, interacting with platinum nickel foil targets. breakup (ionization) in same targets yields characteristic pairs, called "atomic pairs," small relative momenta Q pair center-of-mass system. upgraded DIRAC experiment observed 349±62 such atomic corresponding to a signal 5.6 standard deviations. This first statistically...
The goal of the DIRAC experiment at CERN is to measure with high precision lifetime π + -atom (A 2π ), which order 3×10 -15 s, and thus determine s-wave ππ-scattering lengths difference |a 0 -a 2 |.A atoms are detected through characteristic features -pairs from atom break-up (ionization) in target.We report on a first statistics atomic data sample obtained p Ni interactions 24 GeV/c proton momentum present methods separate signal background.
We present evidence for the first observation of electromagnetically bound $\pi^\pm K^\mp$-pairs ($\pi K$-atoms) with DIRAC experiment at CERN-PS. The $\pi K$-atoms are produced by 24 GeV/c proton beam in a thin Pt-target and $\pi^\pm$ $K^\mp$-mesons from atom dissociation analyzed two-arm magnetic spectrometer. observed enhancement low relative momentum corresponds to production 173 $\pm$ 54 K$-atoms. mean life is related s-wave K$-scattering lengths, measurement which goal experiment. From...
After observing and investigating the double-exotic (a atom is a bound system, in which both oppositely charged components are unstable particles like μ,π,K,…) π+π− with ground state lifetime τ of about 3×10−15 s, upgraded DIRAC experiment at CERN PS accelerator observes for first time long-lived states same lifetimes 10−11 s more. The number characteristic pion pairs resulting from breakup (ionisation) atoms amounts to 436±61, corresponding signal-to-error ratio better than 7 standard...
The spontaneous breaking of chiral symmetry implies the presence a short-distance scale in QCD vacuum, which phenomenologically may be associated with size constituent quark, $\ensuremath{\rho}\ensuremath{\approx}0.3\text{ }\text{ }\mathrm{fm}$. We discuss role this matrix elements twist-4 and 3 quark-gluon operators determining leading power ($1/{Q}^{2}$)-corrections to moments nucleon spin structure functions. argue that flavor-nonsinglet element, ${f}_{2}^{u\ensuremath{-}d}$, has sizable...
After having announced the statistically significant observation (5.6~$\sigma$) of new exotic $\pi K$ atom, DIRAC experiment at CERN proton synchrotron presents measurement corresponding atom lifetime, based on full data sample: $\tau = (5.5^{+5.0}_{-2.8}) \cdot 10^{-15}s$. By means a precise relation ($<1\%$) between lifetime and scattering length, following value for S-wave isospin-odd length $a_0^{-}~=~\frac{1}{3}(a_{1/2}-a_{3/2})$ has been derived: $\left|a_0^-\right|...
In this work the Coulomb effects (Coulomb correlations) in $\pi^+\pi^-$ pairs produced p + Ni collisions at 24 GeV/$c$, are studied using experimental pair distributions $Q$, relative momentum center of mass system (c.m.s), and its projections $Q_L$ (longitudinal component) $Q_t$ (transverse to direction laboratory (l.s.). The $Q_L$, {\sl pairs} c.m.s. have been simulated assuming they described by phase space modified known point-like correlation function $A_C(Q)$, corrected for small due...
In this work, the Coulomb effects (Coulomb correlations) in <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>π</a:mi><a:mo>+</a:mo></a:msup><a:msup><a:mi>π</a:mi><a:mo>−</a:mo></a:msup></a:math> pairs produced <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mrow><c:mi mathvariant="normal">p</c:mi><c:mo>+</c:mo><c:mi>Ni</c:mi></c:mrow></c:math> collisions at <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"...