3,884 research outputs found
Studies of Exclusive e+e- -> hadrons Reactions with Baryons and Strange Particles Using Initial State Radiation at Babar
New Babar results on exclusive e+e- -> hadrons reactions at low c.m. energy
with a baryon-antibaryon or K\bar{K} pair in the final state are presented.
Cross sections are measured using the initial state radiation technique from
the threshold up to 4--5 GeV. From the measured e+e- -> proton\antiproton,
Lambda\Lbar, Sigma0\Sigbar0, Lambda\Sigbar0(Sigma0\Lbar) cross sections we
derive effective baryon form factors and compare them with predictions. We
measure the K\bar{K}\pi(\eta), K+K-\pi\pi, K+K-3\pi, K+K-4\pi, K+K-K+K- final
states and also study their internal structure. A new Y(2175) state is observed
in e+e- -> K+K-f0(980), with f0\to\pi\pi. The total measured e+e- annihilation
cross section into final states including strange baryons or strange mesons is
estimated to be 10% of the full hadronic cross section.Comment: Talk at HADRON07 Conferenve, Frascati, October 8-13, 2007, 8 page
Coulomb effects in the spin-dependent contribution to the intra-beam scattering rate
Coulomb effects in the intra-beam scattering are taken into account in a way
providing correct description of the spin-dependent contribution to the beam
loss rate. It allows one to calculate this rate for polarized beams
at arbitrarily small values of the ratio ,
characterizing relative change of the electron energy in the laboratory system
during scattering event.Comment: 8 pages, 2 figure
Beam energy measurement at linear colliders using spin precession
Linear collider designs foresee some bends of about 5-10 mrad. The spin
precession angle of one TeV electrons on 10 mrad bend is 23.2 rad and it
changes proportional to the energy. Measurement of the spin direction using
Compton scattering of laser light on electrons before and after the bend allows
determining the beam energy with an accuracy about of 10^{-5}. In this paper
the principle of the method, the procedure of the measurement and possible
errors are discussed. Some remarks about importance of plasma focusing effects
in the method of beam energy measurement using Moller scattering are given.Comment: 7 pages, Latex, 4 figures(.eps). In v.3 corresponds to journal
publication. Talk at 26-th Advanced ICFA Beam Dynamic Workshop on
Nanometre-Size Colliding Beams (Nanobeam2002), Lausanne, Switzerland, Sept
2-6, 200
Introducing a spread into the Kyle model
The Kyle (1985) model is extended to take into account market maker competition and the spread. It is shown that with a spread the Kyle model has a Nash equilibrium also with two market makers, not only with three or more, as shown in earlier research. The spread is endogenized, and two testable predictions of the model are generated. The first is that the spread is increasing in the standard deviation of the fundamentals. The second is that it is independent of the standard deviation of noise trades.market microstructure; spread; market maker;
Accurate Calibration Of The Beam Energy In A Storage Ring based On measurement Of Spin Precession Frequency Of Polarized Particles
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