This investigation was performed with a 24-liter propane bubble chamber [i] and is a continu- ation of our previous work on the production of strange particles by 7-8-BeV 1r- mesons on hydrogen and carbon. [ 2 - 5 ] The properties of 1r 0 mesons inferred from the y quanta accom- panying A and K 0 production are given, and are compared with the properties of 1r+ and 7r- mesons emitted in A and K 0 production processes. The possibility of a resonance with radi- ative decay is noted.
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We present high precision measurements of elliptic flow near midrapidity ($|y|<1.0$) for multi-strange hadrons and $\phi$ meson as a function of centrality and transverse momentum in Au+Au collisions at center of mass energy $\sqrt{s_{NN}}=$ 200 GeV. We observe that the transverse momentum dependence of $\phi$ and $\Omega$ $v_{2}$ is similar to that of $\pi$ and $p$, respectively, which may indicate that the heavier strange quark flows as strongly as the lighter up and down quarks. This observation constitutes a clear piece of evidence for the development of partonic collectivity in heavy-ion collisions at the top RHIC energy. Number of constituent quark scaling is found to hold within statistical uncertainty for both 0-30$\%$ and 30-80$\%$ collision centrality. There is an indication of the breakdown of previously observed mass ordering between $\phi$ and proton $v_{2}$ at low transverse momentum in the 0-30$\%$ centrality range, possibly indicating late hadronic interactions affecting the proton $v_{2}$.
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We use 772$\times 10^6$ $B \bar{B}$ meson pairs collected at the $\Upsilon(4S)$ resonance with the Belle detector to measure the branching fraction for $\bar{B} \rightarrow X_s \gamma$. Our measurement uses a sum-of-exclusives approach in which 38 of the hadronic final states with strangeness equal to $+1$, denoted by $X_s$, are reconstructed. The inclusive branching fraction for $M_{X_s}<$ 2.8 GeV/$c^2$, which corresponds to a minimum photon energy of 1.9 GeV, is measured to be ${\cal B}(\bar{B} \rightarrow X_s \gamma)=(3.51\pm0.17\pm0.33)\times10^{-4}$, where the first uncertainty is statistical and the second is systematic.
The yields and partial branching fraction in each $M_{X_s}$ mass bin for the decay $\bar{B} \rightarrow X_s \gamma$, where $\bar{B}$ is either $\bar{B}^0$ or $B^-$, $X_s$ denotes all the hadron combinations that carry strangeness of +1, and charge conjugation is implied.
We have measured inclusive data on $K^+$-meson production in $pp$ collisions at COSY J\"ulich close to the hyperon production threshold and determined the hyperon-nucleon invariant mass spectra. The spectra were decomposed into three parts: $\Lambda p$, $\Sigma^0p$ and $\Sigma^+n$. The cross section for the $\Sigma^+n$ channel was found to be much smaller than a previous measurement in that excess energy region. The data together with previous results at higher energies are compatible with a phase space dependence.
Total cross section for P P --> K+ SIGMA+ N. Errors are combined statistics and systematics.
Deduced total cross section for P P --> K+ P LAMBDA.
Deduced total cross section for P P --> K+ SIGMA0 P.
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A measurement of the cross section for the combined two-photon production of charged pion and kaon pairs is performed using 1.2~$\rm fb^{-1}$ of data collected by the CLEO~II detector at the Cornell Electron Storage Ring. The cross section is measured at invariant masses of the two-photon system between 1.5 and 5.0 GeV/$c^2$, and at scattering angles more than $53^\circ$ away from the $\gamma\gamma$ collision axis in the $\gamma\gamma$ center-of-mass frame. The large background of leptonic events is suppressed by utilizing the CsI calorimeter in conjunction with the muon chamber system. The reported cross section is compared with leading order QCD models as well as previous experiments. In particular, although the functional dependence of the measured cross section disagrees with leading order QCD at small values of the two-photon invariant mass, the data show a transition to perturbative behavior at an invariant mass of approximately 2.5 GeV/$c^2$. hardcopies with figures can be obtained by writing to to: Pam Morehouse preprint secretary Newman Lab Cornell University Ithaca, NY 14853 or by sending mail to: preprints@lns62.lns.cornell.edu
There is an additional 10 pct point-to-point systematic error as well as the overall uncertainty given above.
A study is made of the rescattering phenomenon in deuterons by means of an analysis of ν/xxx;-d interactions in the WA25 (BEBC) experiment at CERN. Experimental data are presented on the rescattering fraction, its energy and multiplicity dependence, on the rapidity spectra of specific particles, on the multiplicity properties of rescatter interactions, and on strange-particle production. Rescattering offers an opportunity to study the behaviour of the produced particlein statu nascendi. The experimental phenomena are discussed in the framework of the formation time formalism. The proper time of hadronization τf is evaluated to be ∼0.5fm/c. A possible reduction of formation time in low-multiplicity events is discussed. Some differences between neutrino and hadron-induced rescattering in deuterons are attributed to the constituent quark structure of pions and nucleons. The experimental results are relevant for the issue of quark-gluon plasma formation in heavy-ion collisions.
ODD NUMBER OF HADRONS.
ODD NUMBER OF HADRONS.
ODD NUMBER OF HADRONS.
The production of neutral strange particles (K0, Λ) inp Ar,pXe and\(\bar p\)Xe collisions at 200 GeV is investigated in the NA5 experiment using a streamer chamber at the CERN SPS. Results are presented on inclusive cross sections, average multiplicities, and on rapidity and transverse momentum distributions of neutral strange particles.
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We present the results of an experiment to search for associated charm production near threshold in 13-GeV/c π−p interactions. A large aperture PWC spectrometer was sensitive to the decay fragments of the forward-produced D*−’s expected from the two-body reactions π−+p→D*−+Λc+,Σc +,. . . . The missing baryon mass was determined from the vector momenta of the incident pion and the candidate D*−. No evidence for these reactions was found, which resulted in a 7-nb upper limit (95% confidence level) for each of the cross sections σ(π−p→D*−Λc+) and σ(π−p→D*−Σc+).
Axis error includes +- 0.0/0.0 contribution (?////NOT GIVENDECAY-BR(BRN=D*(2010)- --> AD0 PI-,BR=64 IN PCT)//DECAY-BR(BRN=AD0 --> K+ PI-, BR=3 IN PCT)).
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We report measurements from the CLEO detector of the rate of Ξ and Λ production in e+e− interactions in the upsilon region. Hyperon production from the decay of the ϒ(1s) is compared with continuum e+e− data. The ratio of the production rates of Λ (and Λ―) to K0 (and K―0) on the ϒ(1s) is 0.21 ± 0.03, much larger than in the continuum, 0.07 ± 0.01. The ratios of the production rates of the Ξ and Λ are comparable, 0.10±0.02 [ϒ(1S)] and 0.07 ± 0.02 (continuum). We discuss some implications of the data for gluon and quark fragmentation models.
CONTINUUM IS ECM 10.38 TO 10.64 GEV.
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CS FOR GIVEN REACTIONS BASED ON THE SAME STATISTICS FROM THE SAME EXPERIMENT ARE ALSO PRESENTED IN THE PAPER A.GIVERNAUD ET AL.,NP B160, 445, 1979, BUT NUMBERS ARE DIFFERENT DUE TO DIFFERENT CORRECTIONS FOR SLOW PROTONS.
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The energy dependence of the transverse momentum invariant distribution of pions and neutral kaons is studied in K − p interactions between 14.3 and 70 GeV/ c . The large P T part of the distributions violates the Feynman scaling and, above P T ≃ 1.5 GeV/ c , appears to be reasonably described by hard scattering models. The variation of the average transverse momentum is also studied as a function of the c.m. reduced longitudinal momentum, and its behaviour is compared to the data obtained via the hadronic shower produced in lepton-hadron interactions.
HERE K0 MEANS K0 OR AK0 I.E. K(NEUTRAL).
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FOR REACTION K+ P --> K0 ANYTHING K0S ARE PROMPT.
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We have studied inclusive KS0, Λ, and Λ¯ production in π+d interactions at 24 GeV/c. The observed cross sections are 2.5±0.13 mb for KS0, 1.62±0.09 mb for Λ, and 0.12±0.02 mb for Λ¯. Longitudinal- and transverse-momentum distributions of the produced particles are presented. The average charged multiplicities of the system associated with a KS0 or with a Λ are presented and discussed. A nonzero average Λ polarization (-0.10±0.03) is observed. The x distribution of the backward (forward) KS0 and Λ produced in the reaction are in agreement with the x distribution of valence quarks in nucleons in nuclear target (pion beam), as predicted by the quark-recombination model of particle production applied to nuclear targets.
Axis error includes +- 0.0/0.0 contribution (?////THE QUOTED IN THE TABLES ERROR INCLUDE ESTIMATES OF UNCERTAINTY IN EACH OF THE CORRECTIONS MADE IN ADDITION TO THE STATISTICAL ERRORCORRECTIONS HAVE BEEN MADE FOR DETECTION, MEASURING, AND FITTING LOSSES AS WELL AS FOR NEUTRAL DECAY MODES OF THE STRANGE PARTICLESNO CORRECTION WAS MADE FOR CONTAMINATION FROM KL'S NOR FOR UNAVOIDABLE INCLUSION OF SIGMA0 EVENTS).
Axis error includes +- 0.0/0.0 contribution (?////THE QUOTED IN THE TABLES ERROR INCLUDE ESTIMATES OF UNCERTAINTY IN EACH OF THE CORRECTIONS MADE IN ADDITION TO THE STATISTICAL ERRORCORRECTIONS HAVE BEEN MADE FOR DETECTION, MEASURING, AND FITTING LOSSES AS WELL AS FOR NEUTRAL DECAY MODES OF THE STRANGE PARTICLESNO CORRECTION WAS MADE FOR CONTAMINATION FROM KL'S NOR FOR UNAVOIDABLE INCLUSION OF SIGMA0 EVENTS).
Axis error includes +- 0.0/0.0 contribution (?////THE QUOTED IN THE TABLES ERROR INCLUDE ESTIMATES OF UNCERTAINTY IN EACH OF THE CORRECTIONS MADE IN ADDITION TO THE STATISTICAL ERRORCORRECTIONS HAVE BEEN MADE FOR DETECTION, MEASURING, AND FITTING LOSSES AS WELL AS FOR NEUTRAL DECAY MODES OF THE STRANGE PARTICLESNO CORRECTION WAS MADE FOR CONTAMINATION FROM KL'S NOR FOR UNAVOIDABLE INCLUSION OF SIGMA0 EVENTS).
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MISPRINT CORRECTED DATA PRESENTED BY D.I.PATALAKHA.
The differential cross section of K − p and K + p elastic scattering has been measured at 4.2, 7 and 10 GeV/ c in the very forward region of scattering angles. The measurements have been made at the CERN PS by means of multiwire proportional chambers and counters. The region of momentum transfers t is 0.001 ⩽ | t | ⩽ 0.10 GeV 2 at the highest momentum and 0.001 ⩽ | t | ⩽ 0.03 GeV 2 at the lowest. Over these regions the Coulomb and the nuclear amplitudes reach their maximum interference. We have used a parametrisation of the above amplitudes to determine the value of the real part of the nuclear forward scattering amplitude. A dispersion relation fit has then been performed using these and earlier measurements; the asymptotic behaviour of the K ± p real parts has been examined in the light of this fit.
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