The p+p→π++d reaction is studied at excess energies between 0.275 and 3.86 MeV. Differential and total cross section were measured employing a magnetic spectrometer with nearly 4π acceptance in the center of mass system. The measured anisotropies between 0.008 and 0.29 indicate that the p wave is not negligible even so close to threshold. The data are compared to other data offering no evidence for charge symmetry breaking or time reversal violation. The s-wave and p-wave contributions at threshold are deduced.
The CONST is p-wave contribution to the cross section. The differential cross section is fitted usig the relations 4*pi*D(SIG)/D(OMEGA) = SIG + CONST*P2(COS(THETA)), where P2 denotes the Legendre polynomial.
We present a measurement of the forward-backward charge asymmetry of the process pp¯→Z0/γ+X,Z0/γ→e+e− at Mee>MZ, using 110pb−1 of data at s=1.8TeV collected at the Collider Detector at Fermilab. The measured charge asymmetries are 0.43±0.10 in the invariant mass region Mee>105GeV/c2, and 0.070±0.016 in the region 75<Mee<105GeV/c2. These results are consistent with the standard model values of 0.528±0.009 and 0.052±0.002, respectively.
The forward-backward asymmetry resuts from angular differential cross section : D(SIG)/D(COS(THETA*) = A*(1 + COS(THETA*)**2) + B*COS(THETA*), where THETA * is the emission angle of the E- relative to the quark momentum in the rest frame of the E+ E- pair.