The inclusive production cross section of Λ, Λ¯ in e+e− annihilation at a c.m. energy of 29 GeV has been measured with the time-projection-chamber detector at PEP. The average Λ, Λ¯ multiplicity has been measured to be 0.197 ± 0.012(stat.) ±0.017(syst.). Λ−Λ¯ pairs have been observed in jets for the first time, and the average number of Λ−Λ¯ pairs per event has been measured to be 0.042 ± 0.017 ± 0.014.
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The inclusive production cross sections and transverse momentum distributions of K*0 and KS0 mesons in e+e− annihilation at a center-of-mass energy of 29 GeV have been measured by means of the time projection chamber detector in the PEP-4 experiment. The mean multiplicites are found to be 0.49 ± 0.04(stat.) ± 0.07(syst.) (K*0+K―*0) and 1.22 ± 0.03(stat.) ±0.15(syst.) (K0+K―0) per event.
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Bose-Einstein correlations between like-sign pions have been investigated in e+e− annihilation at √s =29 GeV using the Time Projection Chamber detector at the SLAC e+e− storage ring PEP. The production rate of like-sign pion pairs with small relative momentum is found to be increased by more than 50% over the rate expected for uncorrelated production of pions. From the correlation length, a typical source radius of 0.65 fm is derived. Data are consistent with a spherical shape of the pion source. No dependence of radius or correlation strength on the event multiplicity is observed.
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Evidence for a narrow state decaying into an F meson and a photon has been obtained in e+e− annihilation events at 29-GeV c.m. energy. This state lies 139.5 ± 8.3(stat.) ± 9.7(syst.) MeV above the F-meson mass and is consistent with the expected F* meson. The F mesons are identified by a peak in the K+K−Kπ± mass at 1.948±0.028±0.010 GeV.
DATA REQUESTED FROM AUTHORS.
IN (K+K-PI+) THE AUTHORS INCLUDE OTHER DECAY MODES SUCH AS (AK*0 K+),(PHI PI+),(K+ K- PI+,PI0),(K+ K- MU+ NU) WHICH CANNOT BE RESOLVED.
Production of φ mesons in e+e− annihilation at a center-of-mass energy of 29 GeV has been observed with the time-projection chamber detector at the PEP storage ring. The φ production rate has been measured in the energy range 0.075<x<0.55 (x=2Eφs), giving 0.077±0.012(stat)±0.016(syst) φ's per event. The average value of pt2 relative to the thrust axis is 1.0±0.4 (GeV/c)2.
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EXTRAPOLAATION TO ALL X USES LUND MONTE CARLO PREDICTIONS.
ERRORS ARE BOTH STATISTICAL AND SYSTEMATIC. PT IS MEASURED RELATIVE TO THE EVENT THRUST AXIS, AND IS FOUND TO HAVE A MEAN VALUE OF 1.0 +- 0.4 GEV.
We present a study of jet multiplicities based on 37 000 hadronic Z 0 boson decays. From this data we determine the strong coupling constant α s =0.115±0.005 ( exp .) −0.010 +0.012 (theor.) to second order QCD at √ s =91.22GeV.
Errors are combined statistical and systematic uncertainties.
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Data on inclusive and semi-inclusive production of nonstrange meson resonances from a bubble chamber study of pn interactions at 19 GeV/c are presented. Most of the results concern ρ0 production. The inclusive cross-sectionσ(pn → ρ0+x)=(2.4±0.4) mb agrees well with pp data. The ρ0 cross-sections are equal in the protonlike and neutron-like hemispheres. The differential cross-sections are in general agreement with earlier observation in pp interactions. In the fragmentation region the approximate structure function can be described byEdσ/dx= =a(1−|x|)n withn=3.0±0.8 in agreement with recent predictions from quark counting rules. The production of ω(780) is observed in the reaction pn→pp+ω+X with a cross-section σ=(0.13±0.03) mb. There is indication of f0(1270) and g(1680) production.
Axis error includes +- 0.0/0.0 contribution (?////FITTING ERRORRES-DEF(RES=RHO0,BACK=CORRECTED,DEF=0.5 < M(PI+ PI-) < 1.05 GEV,C=MASS AND WIDTH FROM PDG 1980)//RES-DEF(RES=F,BACK=CORRECTED,DEF=0.9 < M(PI+ PI-) < 1.5 GEV,C=MASS AND WIDTH FROM PDG 1980)//RES-DEF(RES=G(1700)0,BACK=CORRECTED,DEF=1.36 < M(PI+ PI-) < 2.1 GEV,C=MASS AND WIDTH FROM PDG 1980)NO REFLECTIONS ,E.G. FROM DEL++, DEL-, OMEGA HAVE BEEN CONSIDERED).
Axis error includes +- 0.0/0.0 contribution (?////FITTING ERRORRES-DEF(RES=RHO0,BACK=CORRECTED,DEF=0.5 < M(PI+ PI-) < 1.05 GEV,C=MASS AND WIDTH FROM PDG 1980)//RES-DEF(RES=F,BACK=CORRECTED,DEF=0.9 < M(PI+ PI-) < 1.5 GEV,C=MASS AND WIDTH FROM PDG 1980)//RES-DEF(RES=G(1700)0,BACK=CORRECTED,DEF=1.36 < M(PI+ PI-) < 2.1 GEV,C=MASS AND WIDTH FROM PDG 1980)NO REFLECTIONS ,E.G. FROM DEL++, DEL-, OMEGA HAVE BEEN CONSIDERED).
Axis error includes +- 0.0/0.0 contribution (?////FITTING ERRORRES-DEF(RES=RHO0,BACK=CORRECTED,DEF=0.5 < M(PI+ PI-) < 1.05 GEV,C=MASS AND WIDTH FROM PDG 1980)//RES-DEF(RES=F,BACK=CORRECTED,DEF=0.9 < M(PI+ PI-) < 1.5 GEV,C=MASS AND WIDTH FROM PDG 1980)//RES-DEF(RES=G(1700)0,BACK=CORRECTED,DEF=1.36 < M(PI+ PI-) < 2.1 GEV,C=MASS AND WIDTH FROM PDG 1980)NO REFLECTIONS ,E.G. FROM DEL++, DEL-, OMEGA HAVE BEEN CONSIDERED).
The B^0_s differential production cross section is measured as functions of the transverse momentum and rapidity in pp collisions at sqrt(s) = 7 TeV, using the J/Psi phi decay, and compared with predictions based on perturbative QCD calculations at next-to-leading order. The data sample, collected by the CMS experiment at the LHC, corresponds to an integrated luminosity of 40 inverse picobarns. The B^0_s is reconstructed from the decays J/Psi to an oppositely charged muon pair and phi to K+ K-. The integrated B^0_s cross section times B^0_s to J/Psi phi branching fraction in the range 8 < pt(B) < 50 GeV/c and |y(b)| < 2.4 is measured to be 6.9 +/- 0.6 +/- 0.6 nb, where the first uncertainty is statistical and the second is systematic.
Total integrated B/S cross section times the branching fraction to J/PSI PHI in the given kinematic range.
The measured differential cross section as a function of the transverse momentum of the B/S in the |rapidity| range < 24.
The measured differential cross section as a function of the rapidity of the B/S in the transverse momentum range 8 to 50 GeV.
The production of J/psi mesons is studied in pp collisions at sqrt(s)=7 TeV with the CMS experiment at the LHC. The measurement is based on a dimuon sample corresponding to an integrated luminosity of 314 inverse nanobarns. The J/psi differential cross section is determined, as a function of the J/psi transverse momentum, in three rapidity ranges. A fit to the decay length distribution is used to separate the prompt from the non-prompt (b hadron to J/psi) component. Integrated over J/psi transverse momentum from 6.5 to 30 GeV/c and over rapidity in the range |y| < 2.4, the measured cross sections, times the dimuon decay branching fraction, are 70.9 \pm 2.1 (stat.) \pm 3.0 (syst.) \pm 7.8(luminosity) nb for prompt J/psi mesons assuming unpolarized production and 26.0 \pm 1.4 (stat.) \pm 1.6 (syst.) \pm 2.9 (luminosity) nb for J/psi mesons from b-hadron decays.
Total cross section within the kinematic limits for prompt and non-prompt J/PSI production times branching ratio into MU+ MU-, assuming zero polarizartion. The second systematic error is the luminosity uncertainty.
Differential inclusive cross J/PSI section for the |rapidity| range 0 to 1.2 for each prompt J/PSI polarization scenario considered.
Differential inclusive cross J/PSI section for the |rapidity| range 1.2 to 1.6 for each prompt J/PSI polarization scenario considered.
Measurements of the differential production cross sections in transverse momentum and rapidity for B0 mesons produced in pp collisions at sqrt(s) = 7 TeV are presented. The dataset used was collected by the CMS experiment at the LHC and corresponds to an integrated luminosity of 40 inverse picobarns. The production cross section is measured from B0 meson decays reconstructed in the exclusive final state J/Psi K-short, with the subsequent decays J/Psi to mu^+ mu^- and K-short to pi^+ pi^-. The total cross section for pt(B0) > 5 GeV and y(B0) < 2.2 is measured to be 33.2 +/- 2.5 +/- 3.5 microbarns, where the first uncertainty is statistical and the second is systematic.
Total integrated cross section in the given kinematic range. The (sys) error includes all the systematic uncertainties.
Measured differential cross section as a function of the transverse momentum of the B0 particle.
Measured differential cross section as a function of the rapidity of the B0 particle.
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