90 research outputs found
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Test of QED to fourth order by study of four-lepton final states in e+e- interactions at 29 GeV with the Mark II detector.
We have tested QED to fourth order in the coupling constant in the large-Q2 region by studying four-lepton final states in e+e- interactions with the Mark II detector at the SLAC storage ring PEP (s=29 GeV). All four final-state particles were detected at large angles with respect to the beam axis. For an integrated luminosity of 205 pb-1, we observed ten e+e-e+e-, ten e+e-+-, and one events with opposite-charge pair masses greater than 1 GeV/c2. These events show good agreement with the complete 4 QED calculation. © 1990 The American Physical Society
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Test of QED to fourth order by study of four-lepton final states in e+e- interactions at 29 GeV with the Mark II detector.
We have tested QED to fourth order in the coupling constant in the large-Q2 region by studying four-lepton final states in e+e- interactions with the Mark II detector at the SLAC storage ring PEP (s=29 GeV). All four final-state particles were detected at large angles with respect to the beam axis. For an integrated luminosity of 205 pb-1, we observed ten e+e-e+e-, ten e+e-+-, and one events with opposite-charge pair masses greater than 1 GeV/c2. These events show good agreement with the complete 4 QED calculation. © 1990 The American Physical Society
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Inclusive charged hadron and K0 production in two-photon interactions
The inclusive transverse momentum distributions of charged hadrons and K0's produced in tagged photon-photon collisions, are measured and compared to model calculations up to a pT of 5 GeV/c. The relative abundance of K0's favor the inclusion of charm. © 1993
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eta and eta ' production in e+e- annihilation at 29 GeV. Evidence for the Dx+/- decays into eta pi +/- and eta ' pi +/-
The Production has been investigated by the Mark II collaboration at the SLAC e+e- storage ring PEP. particles are reconstructed by their decay mode. The fragmentation function has been measured and found to be in good agreement with the Lund-model prediction. production has been measured for the first time in high-energy e+e- annihilation. There is evidence at the 3 level for Ds± decay into ± and ±. © 1988 The American Physical Society
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Refined measurement of the B-hadron lifetime.
We report a new measurement of the average lifetime of hadrons containing bottom quarks. The B-hadron decays are tagged by identifying leptons at high transverse momentum. From a fit to the lepton impact-parameter distribution, the average B-hadron lifetime is found to be (0.98 0.12 0.13)×10-12 sec. © 1989 The American Physical Society
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Measurement of single and double radiative low-Q2 Bhabha scattering at Ec.m.
The process e+e-e+e-(), where one electron scatters at a small angle, is studied with data from the Mark II detector at the SLAC storage ring PEP. The data are in excellent agreement with a Monte Carlo calculation and include a large contribution from order 4. The ratio of measured to calculated cross sections is R=0.9930.0170.015, where the first error is statistical and the second systematic. This is a sensitive test of the calculation of the dominant background for neutrino-counting experiments. © 1989 The American Physical Society
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Upper limit on the mass
We have set an upper limit on the mass from a study of the four-pion invariant-mass distribution in the decay 3 0. We obtain the limit m <164 MeV/c2 at 95% confidence level. © 1984 The American Physical Society
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eta and eta ' production in e+e- annihilation at 29 GeV. Evidence for the Dx+/- decays into eta pi +/- and eta ' pi +/-
The Production has been investigated by the Mark II collaboration at the SLAC e+e- storage ring PEP. particles are reconstructed by their decay mode. The fragmentation function has been measured and found to be in good agreement with the Lund-model prediction. production has been measured for the first time in high-energy e+e- annihilation. There is evidence at the 3 level for Ds± decay into ± and ±. © 1988 The American Physical Society
Recommended from our members
Inclusive charged hadron and K0 production in two-photon interactions
The inclusive transverse momentum distributions of charged hadrons and K 's produced in tagged photon-photon collisions, are measured and compared to model calculations up to a p of 5 GeV/c. The relative abundance of K 's favor the inclusion of charm. © 1993. 0 0
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