A. Magiera

New method for a continuous determination of the spin tune in storage rings and implications for precision experiments

A new method to determine the spin tune is described and tested. In an ideal planar magnetic ring, the spin tune-defined as the number of spin precessions per turn-is given by ν(s)=γG (γ is the Lorentz factor, G the gyromagnetic anomaly). At 970u2009u2009MeV/c, the deuteron spins coherently precess at a frequency of ≈120u2009u2009kHz in the Cooler Synchrotron COSY. The spin tune is deduced from the up-down asymmetry of deuteron-carbon scattering. In a time interval of 2.6 s, the spin tune was determined with a precision of the order 10^{-8}, and to 1×10^{-10} for a continuous 100 s accelerator cycle. This renders the presented method a new precision tool for accelerator physics; controlling the spin motion of particles to high precision is mandatory, in particular, for the measurement of electric dipole moments of charged particles in a storage ring.

Simultaneous measurements of the p+d→(A=3)+π reactions

A stack of annular detectors made of high purity germanium was used to measure simultaneously

Near threshold η meson production in the dd→4Heη reaction

pdto {^3H} pi^+

Search for η-mesic He4 in the dd→He3nπ0 and dd→He3pπ− reactions with the WASA-at-COSY facility

and

Measurements of branching ratios for

pdto {^3He} pi^0

\eta

differential cross sections at beam momenta of 750 MeV/c, 800 MeV/c, and 850 MeV/c over a large angular range. The extracted total cross sections for the

decays into charged particles

pdto {^3He} pi^0

Measurement of the (n)over-right-arrowp -g d pi(0) pi(0) reaction with polarized beam in the region of the d(*)(2380) resonance

reactions bridge a gap between near threshold data and those in the resonance region. The ratio of the cross sections for the two reaction channels taken at the same

Measurement of the

eta={p^{cm}_pi}/m_pi

\overrightarrow{n} p\rightarrow d\pi^{0}\pi^{0}

yields