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We present a new measurement of parity nonconservation in cesium. In this experiment, a laser excited the 6S→7S transition in an atomic beam in a region of static electric and magnetic fields. The quantity measured was the component of the transition rate arising from the interference between the parity nonconserving amplitude, scrEPNC, and the Stark amplitude, βE. Our results are ImscrEPNC/β=−1.65±0.13 mV/cm and C2p=-2±2, where C2p is the proton-axial-vector–electron-vector neutral-current coupling constant. These results are in agreement with previous less precise measurements in cesium and with the predictions of the electroweak standard model. We give a detailed discussion of the experiment with particular emphasis on the treatment and elimination of systematic errors. This experimental technique will allow future measurements of significantly higher precision.
Axis error includes +- 0.0/0.0 contribution (?////THE UNCERTAINTY IS DOMINATED BY THE PURELY STATISTICAL CONTRIBUTION).
Axis error includes +- 0.0/0.0 contribution (?////THE UNCERTAINTY IS DOMINATED BY THE PURELY STATISTICAL CONTRIBUTION).
Axis error includes +- 0.0/0.0 contribution (?////THE UNCERTAINTY IS DOMINATED BY THE PURELY STATISTICAL CONTRIBUTION).
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MULTIPLICITIES OF PI0 WAS OBTANED FROM MULTIPLICITIES OF GAMMAS: MULT(PI0)=MULT(GAMMA)/2.
PI- NUCLEON= (PI- P + PI- N)/2.
PI- NUCLEON= (PI- P + PI- N)/2.
The reactione+e−→e+e− A2 (1320) has been observed by detecting the decayA2→π+,π-π0. The two-photon width of theA2 has been measured to be Г(A2→γγ)=(0.09±0.27 (stat)±0.16 (syst)) keV. The cross section σ(γγ→π+,π-π0 has been determined outside theA2 resonance region.
Data read off a graph.
Total and differential cross sections for exclusive production of proton-antiproton pairs in photon-photon collisions have been measured using the JADE detector at PETRA. The total cross section in the CM angular |cos θ ∗ | < 0.6 reaches a maximum value of 3.8 nb for a γγ invariant mass of W γγ = 2.25 GeV, and decreases rapidly for higher values of W γγ . In the range 2.0 GeV < W γγ < 2.6 GeV the angular distribution is not isotopic. The nucleons are preferentially emitted at large angles to the collision axis.
Data read off graph.
Data read off graph.
We present a measurement of the hadronic structure function F 2 γ ( x , Q 2 ) of the photon in the Q 2 range from 10 to 100 GeV 2 . Data were taken with the PLUTO detector at the e + e - storage ring PETRA. This measurement and previous PLUTO measurements in the Q 2 range of 1.5 to 16 GeV 2 are compared with higher order QCD calculations. The structure function is consistent with the predicted log Q 2 behaviour when charm contributions are subtracted. The x dependence can be well described for 0.1 < x < 0.9 by the regularization scheme of Antoniadis and Grunberg. Within their scheme the data yield a value of Λ MS = 183 + 65/ −40( stat. ) + 46/ −36( sys. ) MeV for the QCD scale parameter.
Data read from graph.
Data read from graph.
Data read from graph.
The cross section for the processe+e−→π0+ anything has been measured at an average center of mass energy of 34.6 GeV for π0 energies between 0.7 and 17 GeV. The angular distribution for π0 energies larger than 2 GeV is of the formdσ/dΩ∼1+Acos2θ, withA=1.2±0.5. The ratio of π0 to π± production in the measured energy range is 2σ(π0)/(σ(π+)+σ(π−))=1.13±0.18
Systematic errors included.
Systematic errors included.
No description provided.
The inclusive production of D ∗± mesons in single tagged photon-photon collisions is investigated using the JADE detector at PETRA. D ∗± mesons are reconstructed through their decay into D 0 +π ± where the D 0 decays via D 0 →Kππ 0 . The event rate and topology are compared to the expectations of c quark production in the quark-parton model: γγ→c c .
No description provided.