2,642 research outputs found
Hadron Production via e+e- Collisions with Initial State Radiation
A novel method of studying e+e- annihilation into hadrons using initial state
radiation at e+e- colliders is described. After brief history of the method,
its theoretical foundations are considered. Numerous experiments in which
exclusive cross sections of e+e- annihilation into hadrons below the
center-of-mass energy of 5 GeV have been measured are presented. Some
applications of the results obtained to fundamental tests of the Standard Model
are listed.Comment: 50 pages, 88 figures, accepted for publication in Rev. Mod. Phy
Dynamics of a small neutrally buoyant sphere in a fluid and targeting in Hamiltonian systems
We show that, even in the most favorable case, the motion of a small
spherical tracer suspended in a fluid of the same density may differ from the
corresponding motion of an ideal passive particle. We demonstrate furthermore
how its dynamics may be applied to target trajectories in Hamiltonian systems.Comment: See home page http://lec.ugr.es/~julya
Measurement of hadron cross sections with the SND detector
New results on exclusive hadron production in annihilation obtained
in experiments with the SND detector at the VEPP-2M and VEPP-2000
colliders are presented.Comment: 4 pages, 4 figures, presented at the 14th International Workshop on
Meson Production, Properties and Interaction (MESON 2016), Cracow, Poland,
2nd - 7th June 201
Study of the process e+e-\to \mu+\mu- in the energy region \sqrt{s}=980, 1040 -- 1380 MeV
The cross section of the process e+e-\to\mu+\mu- was measured in the SND
experiment at the VEPP-2M e+e- collider in the energy region \sqrt{s}=980, 1040
-- 1380 MeV. The event numbers of the process e+e-\to\mu+\mu- were normalized
to the integrated luminosity measured using e+e-\to e+e- and
e+e-\to\gamma\gamma processes. The ratio of the measured cross section to the
theoretically predicted value is 1.006\pm 0.007 \pm 0.016 and 1.005 \pm 0.007
\pm 0.018 in the first and second case respectively. Using results of the
measurements, the electromagnetic running coupling constant \alpha in the
energy region \sqrt{s}=1040 -- 1380 MeV was obtained = 134.1\pm 0.5
\pm 1.2 and this is in agreement with theoretical expectation.Comment: 29 pages, 23 figure
Strangeness production in proton-proton and proton-nucleus collisions
In these lectures we discuss the investigation of the strange meson
production in proton-proton () and in proton-nucleus () reactions
within an effective Lagrangian model. The kaon production proceeds mainly via
the excitations of (1650), (1710), and (1720) resonant
intermediate nucleonic states, in the collision of two initial state nucleons.
Therefore, the strangeness production is expected to provide information about
the resonances lying at higher excitation energies. For beam energies very
close to the kaon production threshold the hyperon-proton final state
interaction effects are quite important. Thus, these studies provide a check on
the models of hyperon-nucleon interactions. The in-medium production of kaons
show strong sensitivity to the self energies of the intermediate mesons.Comment: 16 pages, 9 figures, Talk presented in the workshop on Hadron
Physics, Puri, India, March 7-17,200
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