FAST TARGET FRAGMENTS IN INTERACTIONS OF RELATIVISTIC NUCLEI WITH PHOTOEMULSION. (IN RUSSIAN)

Antonchik, V.A. ; Bakaev, V.A. ; Bogdanov, V.G. ; et al.
Yad.Fiz. 46 (1987) 1344-1352, 1987.
Inspire Record 256945 DOI 10.17182/hepdata.2434

None

38 data tables

No description provided.

No description provided.

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Observation and Study of a Narrow State in a $\Sigma^-$ (1385) $K^+$ System

The Berlin-Budapest-Dubna-Moscow-Prague-Sofiya-Tbilisi collaboration Aleev, A.N. ; Arefev, V.A. ; Balandin, V.P. ; et al.
Z.Phys.C 25 (1984) 205, 1984.
Inspire Record 201523 DOI 10.17182/hepdata.39601

New data on the observation and study of a narrow resonance decaying intoΣ−(1,385)K+ have been obtained. The mass of the resonance is (1,956−6+8) MeV/c2, and its width is (27±15) MeV/c2. The resonance is produced in the diffraction dissociation of neutrons on quasi-free nucleons of carbon nuclei. The slope parameter of the differential cross section inPT2 is (9.9±3.0) (GeV/c)−2. The cross section times the branching ratio is (0.22±0.04) μb per nucleon. The resonance has one of the natural spinparities: 5/2+, 7/2− and so on.

5 data tables

YN IS IN ARBITRARY UNITS.

ARBITRARY UNITS FOR YN.

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Model-independent measurement of the W boson helicity in top quark decays at D0

The D0 collaboration Abazov, V.M. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 100 (2008) 062004, 2008.
Inspire Record 767094 DOI 10.17182/hepdata.47072

We present the first model-independent measurement of the helicity of $W$ bosons produced in top quark decays, based on a 1 fb$^{-1}$ sample of candidate $t\bar{t}$ events in the dilepton and lepton plus jets channels collected by the D0 detector at the Fermilab Tevatron $p\bar{p}$ Collider. We reconstruct the angle $\theta^*$ between the momenta of the down-type fermion and the top quark in the $W$ boson rest frame for each top quark decay. A fit of the resulting \costheta distribution finds that the fraction of longitudinal $W$ bosons $f_0 = 0.425 \pm 0.166 \hbox{(stat.)} \pm 0.102 \hbox{(syst.)}$ and the fraction of right-handed $W$ bosons $f_+ = 0.119 \pm 0.090 \hbox{(stat.)} \pm 0.053 \hbox{(syst.)}$, which is consistent at the 30% C.L. with the standard model.

6 data tables

COS(THETA*) distribution for leptonic W decay in lepton+jets events.. Data are read from plots and errors are statistcial (sqrt(N)).

COS(THETA*) distribution for hadronic W decay in lepton+jets events.. Data are read from plots and errors are statistcial (sqrt(N)).

COS(THETA*) distribution for W decay in dilepton events.. Data are read from plots and errors are statistcial (sqrt(N)).

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Measurements of inelastic J/psi and psi' photoproduction at HERA.

The ZEUS collaboration Chekanov, S. ; Krakauer, D. ; Magill, S. ; et al.
Eur.Phys.J.C 27 (2003) 173-188, 2003.
Inspire Record 601166 DOI 10.17182/hepdata.46546

The cross sections for inelastic photoproduction of J/psi and psi' mesons have been measured in ep collisions with the ZEUS detector at HERA, using an integrated luminosity of 38.0 pb-1. The events were required to have 0.1 < z < 0.9 and 50 < W < 180 GeV, where z is the fraction of the incident photon energy carried by the J/psi in the proton rest frame and W is the photon-proton centre-of-mass energy. The psi' to J/psi cross-section ratio was measured in the range 0.55 < z < 0.9. The J/psi data, for various ranges of transverse momentum, are compared to theoretical models incorporating colour-singlet and colour-octet matrix elements. Predictions of a next-to-leading-order colour-singlet model give a good description of the data, although there is a large normalisation uncertainty. The J/psi helicity distribution for z > 0.4 is compared to leading-order QCD predictions.

10 data tables

Measurment of the total cross section, with various PT thresholds, in the high Z > 0.9 region.

Ratio of cross section for PSI(2S) to J/PSI production. as a function of PT. Statistical errors only.

Ratio of cross section for PSI(2S) to J/PSI production. as a function of W. Statistical errors only.

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A study of parton fragmentation in hadronic Z0 decays using Lambda Antilambda correlations.

The OPAL collaboration Abbiendi, G. ; Ackerstaff, K. ; Alexander, G. ; et al.
Eur.Phys.J.C 13 (2000) 185-195, 2000.
Inspire Record 474010 DOI 10.17182/hepdata.49312

The correlated production of Lambda and Lambdabar baryons has been studied using 4.3 million multihadronic Zo decays recorded with the OPAL detector at LEP. Di-lambda pairs were investigated in the full data sample and for the first time also in 2-jet and 3-jet events selected with the k_t algorithm. The distributions of rapidity differences from correlated Lambda-Lambdabar pairs exhibit short-range, local correlations and prove to be a sensitive tool to test models, particularly for 2-jet events. The JETSET model describes the data best but some extra parameter tuning is needed to improve agreement with the experimental results in the rates and the rapidity spectra simultaneously. The recently developed modification of JETSET, the MOdified Popcorn Scenarium (MOPS), and also HERWIG do not give satisfactory results. This study of di-lambda production in 2- and 3-jet events supports the short-range compensation of quantum numbers.

5 data tables

Average multipicity of LAMBDA pairs in hadronic events.

Average multipicity of LAMBDA pairs in 2-Jet events.

Average multipicity of LAMBDA pairs in 3-Jet events.

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Event shape analysis of deep inelastic scattering events with a large rapidity gap at HERA.

The ZEUS collaboration Breitweg, J. ; Derrick, M. ; Krakauer, D. ; et al.
Phys.Lett.B 421 (1998) 368-384, 1998.
Inspire Record 450130 DOI 10.17182/hepdata.44419

A global event shape analysis of the multihadronic final states observed in neutral current deep inelastic scattering events with a large rapidity gap with respect to the proton direction is presented. The analysis is performed in the range $5 \leq Q^2 \leq 185\gev^2$ and $160 \leq W \leq 250\gev$, where $Q^2$ is the virtuality of the photon and $W$ is the virtual-photon proton centre of mass energy. Particular emphasis is placed on the dependence of the shape variables, measured in the $\gamma^*-$pomeron rest frame, on the mass of the hadronic final state, $M_X$. With increasing $M_X$ the multihadronic final state becomes more collimated and planar. The experimental results are compared with several models which attempt to describe diffractive events. The broadening effects exhibited by the data require in these models a significant gluon component of the pomeron.

21 data tables

Measured (uncorrected) polar distribution of the sphericity axis w.r.t. thevirtual photon direction in the (gamma*-pomeron)rest frame Data are in bins of the mass of the final state hadronic system.

Measured (uncorrected) polar distribution of the sphericity axis w.r.t. thevirtual photon direction in the (gamma*-pomeron)rest frame Data are in bins of the mass of the final state hadronic system.

Measured (uncorrected) polar distribution of the sphericity axis w.r.t. thevirtual photon direction in the (gamma*-pomeron)rest frame Data are in bins of the mass of the final state hadronic system.

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Rescattering probed by the emission of slow target associated particles in high-energy heavy ion interactions

The EMU01 collaboration Adamovich, M.I ; Aggarwal, M.M ; Alexandrov, Y.A ; et al.
Phys.Lett.B 363 (1995) 230-236, 1995.
Inspire Record 406952 DOI 10.17182/hepdata.28438

In this letter the distribution of slow target associated particles emitted in Au + Emulsion interactions at 11.6 A GeV/ c is studied. The three models RQMD, FRITIOF and VENUS are used for comparisons and especially their treatment of rescattering is investigated.

6 data tables

No description provided.

PROJECTILE ASSOCIATED HE-FRAGMENTS.

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A Study of the fragmentation of quarks in e- p collisions at HERA

The H1 collaboration Aid, S. ; Andreev, V. ; Andrieu, B. ; et al.
Nucl.Phys.B 445 (1995) 3-21, 1995.
Inspire Record 394793 DOI 10.17182/hepdata.44978

Deep inelastic scattering (DIS) events, selected from 1993 data taken by the H1 experiment at HERA, are studied in the Breit frame of reference. The fragmentation function of the quark is compared with those of \ee data. It is shown that certain aspects of the quarks emerging from within the proton in \ep interactions are essentially the same as those of quarks pair-created from the vacuum in \ee annihilation. The measured area, peak position and widthof the fragmentation function show that the kinematic evolution variable, equivalent to the \ee squared centre of mass energy, is in the Breit frame the invariant square of the four-momentum transfer. We comment on the extent to which we have evidence for coherence effects in parton showers.

6 data tables

Distribution of the cosine of the Breit frame polar angle for data with the Breit frame energy flow selection. Statistical errors only.

Distribution of the cosine of the Breit frame polar angle for data before the Breit frame energy flow selection. Statistical errors only.

The fragmentation function for the current hemisphere of the Breit frame. Data are Breit frame energy flow selected only. Statistical errors only.

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W boson + jet angular distribution in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, M.G. ; Amidei, D. ; et al.
Phys.Rev.Lett. 73 (1994) 2296-2300, 1994.
Inspire Record 374152 DOI 10.17182/hepdata.42492

The W+jet angular distribution is measured using W→eν events recorded with the Collider Detector at Fermilab (CDF) during the 1988-89 and 1992-93 Tevatron runs. The data agree well with both a leading order and a next-to-leading order theoretical prediction. The shape of the angular distribution is similar to that observed in photon + jet data and significantly different from that observed in dijet data.

2 data tables

Data normalized to 1 in the cos(theta) range -0.6 to 0.6.

Data normalized to 1 in the abs(cos(theta)) range <0.3.


Production and Decay of Charmed Mesons in $e^+ e^-$ Annihilation at $\sqrt{s}$ > 28-{GeV}

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Z.Phys.C 44 (1989) 365, 1989.
Inspire Record 278856 DOI 10.17182/hepdata.15361

We report on a study of inclusive production ofD*± mesons ine+e− annihilation at c.m. energies between 28 and 46.8 GeV using the TASSO detector at the PETRA storage ring. A hardD*± energy spectrum is measured with a maximum nearED*±≃0.6Ebeam. The measured cross section ratio\((\sigma _{D^{* + } }+ \sigma _{D^{* - } } )/\sigma _{\mu \mu }= 1.28 \pm 0.09 \pm 0.18\) indicates thatD* production accounts for a large fraction of the observed charm production. Two complementary methods have been used to determine the forward-backward asymmetry of charm pair production due to electroweak interference. Combining both measurements the product of the axial vector couplings of the electron and the charm quark to the weak neutral current was determined to begAegAc=−(0.276±0.073), in agreement with the standard model prediction of −0.25. Using a sample of reconstructedD*± mesons, the relative strength of the strong interaction coupling of thec quark compared to that of an average of all flavours is measured as αs(c)/αs(all)=0.91±0.38±0.15, consistent with the coupling constant being flavour independent. An update of ourD0 lifetime measurement is presented, based on a considerable increase in statistics, the final result being\(\tau _{D^0= } (4.8 \pm _{0.9 - 0.7}^{1.0 + 0.5} )10^{ - 13} s\).

5 data tables

Cross sections using D0 --> K- PI+ channel.

Cross sections using D0 --> K- PI+ PI- PI+ channel.

No description provided.

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