The production of antideuterons has been observed in electron-positron annihilations at center-of-mass energies around 10 GeV. Antideuterons have been identified unambiguously by their energy loss in the drift chamber, their time-of-flight and the pattern of their energy deposition in the shower counters of the ARGUS detector. The production rate in the momentum range (0.6−1.8) GeV/ c is (1.6 −0.7 +1.0 ) × 10 −5 per hadronic event.
Results from 6 antideuterons detected (3 from UPSI(2S), 2 from (IS) and 1 from (4S)).
No description provided.
We have measured the production of direct photons, π 0 's, and η's in p p and pp collisions at √ s =53 GeV in the range 2≈ p T ≈6 GeV/ c for the central rapidity region | y | 0.4. No statistically significant difference between pp̄ and pp interactions is observed.
No description provided.
No description provided.
No description provided.
Multiplicity distributions of charged particles for inelastic, non single-diffractive events in proton-antiproton collisions at a centre of mass energy of 540 GeV are presented for various pseudorapidity (Δη) intervals. The widths of the multiplicity distributions, scaled to their means, increase as Δη is made smaller, and the deviation from a Poisson distribution becomes progressively more pronounced. It is found that the data are remarkably well described by a negative binomial distribution. The parameters of the distributions vary smoothly with the size of the acceptance interval.
Data for full phase space.
No description provided.
No description provided.
Data from the high-resolution spectrometer at PEP have been used to study the inclusive production of φ mesons and F± mesons decaying into φπ±. Fragmentation functions and cross sections are presented and compared to existing data. The total φ cross section at 29 GeV is 40±6 pb. The observed F signal in the region z>0.4, given the assumption that R(F)[R(F)+R(D)]=0.15, corresponds to an F→φπ branching ratio of (3.3±1.1)%. The measured F mass is 1963±3±3 MeV/c2.
No description provided.
No description provided.
WITH THE FOLLOWING ANGLE CUTS ON THE DECAY REGIONS. PHI DECAY - ABS(COS(THETA)) >0.5.
A search has been made for particles with charge Q = 1 3 , Q = 2 3 and Q = 4 3 produced in e + e − annihilation using the ARGUS detector at the e + e − storage ring DORIS, operating at a centre of mass energy around 10 GeV. No candidate events were found in 84.5 pb −1 of collected data. Upper limits are established for the cross section for the production of fractionally charged particles with masses up to 4 GeV c 2 , improving on previously obtained limits.
Two different models (I and II) are considered (see text).
We present high statistics measurements of the energy-energy correlation (EEC) and its related asymmetry (AEEC) ine+e− annihilation at a c.m. energy of 34.6 GeV. We find that the energy dependence as well as the large angle behaviour of the latter are well described by perturbative QCD calculations toOα(s2). Non-perturbative effects are estimated with the help of fragmentation models in which different jet topologies are separated using (ɛ, δ) cuts, and found to be small. The extracted values of\(\Lambda _{\overline {MS} }\) lie between 100 and 300 MeV.
Corrected energy-energy correlation data.
CORRECTED FORWARD-BACKWARD ASYMMETRY.
None
No description provided.
SIG(Q=L)/SIG(Q=T) ASSUMED TO BE 0.
SIG(Q=L)/SIG(Q=T) ASSUMED TO BE 0.
None
Axis error includes +- 0.0/0.0 contribution (?////TOTAL SYSTEMATICS).
Axis error includes +- 0.0/0.0 contribution (?////TOTAL SYSTEMATICS).
Axis error includes +- 0.0/0.0 contribution (?////TOTAL SYSTEMATICS).
None
No description provided.
No description provided.
No description provided.
None
Pt of the leptons is determined relative to the thrust axis. B-DECAY, C-DECAY, C-SECONDARY and BKG are corresponded to fractions of leptons originationg from primary BQ deacy, primary CQ decay, secondary decay, and from background.
Forum