HEPData Search

Showing 10 of 16 results

Hyperon Production in $e^+ e^-$ Interactions in the $\Upsilon$ Region

The CLEO collaboration Alam, M.S. ; Csorna, S.E. ; Garren, L. ; et al.

Phys.Rev.Lett. 53 (1984) 24, 1984.

Inspire Record 200712 DOI 10.17182/hepdata.20410

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.

2 data tables

Table 1

CONTINUUM IS ECM 10.38 TO 10.64 GEV.

Table 2

No description provided.

rivet Analysis
Two-Photon Production of Charged Pion and Kaon Pairs

The CLEO collaboration Dominick, J. ; Lambrecht, M. ; Sanghera, S. ; et al.

Phys.Rev.D 50 (1994) 3027-3037, 1994.

Inspire Record 372230 DOI 10.17182/hepdata.47104

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

1 data table

Table 1

There is an additional 10 pct point-to-point systematic error as well as the overall uncertainty given above.

Direct observation of the dead-cone effect in QCD

The ALICE collaboration Acharya, S. ; Acharya, S. ; Adamova, D. ; et al.

Nature 605 (2022) 440-446, 2022.

Inspire Record 1867966 DOI 10.17182/hepdata.130725

In particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD). These partons subsequently emit further partons in a process that can be described as a parton shower which culminates in the formation of detectable hadrons. Studying the pattern of the parton shower is one of the key experimental tools for testing QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a heavy quark of mass $m_{\rm{Q}}$ and energy $E$, within a cone of angular size $m_{\rm{Q}}$/$E$ around the emitter. Previously, a direct observation of the dead-cone effect in QCD had not been possible, owing to the challenge of reconstructing the cascading quarks and gluons from the experimentally accessible hadrons. We report the direct observation of the QCD dead cone by using new iterative declustering techniques to reconstruct the parton shower of charm quarks. This result confirms a fundamental feature of QCD. Furthermore, the measurement of a dead-cone angle constitutes a direct experimental observation of the non-zero mass of the charm quark, which is a fundamental constant in the standard model of particle physics.

1 data table

$R(\theta)$

The $R(\theta)$ variable for charm/inclusive emissions in three bins of $E_{Rad}$: 5-10, 10-20 and 20-35 GeV.

CROSS-SECTIONS OF CHANNELS WITH ONE NEUTRAL PARTICLE IN 32-GeV K- p INTERACTIONS

Levitsky, M.S. ; Moiseev, A.M. ; Silinskaya, S.G. ; et al.

IFVE-80-22, 1979.

Inspire Record 147181 DOI 10.17182/hepdata.41627

None

1 data table

Table 1

MISPRINT CORRECTED DATA PRESENTED BY D.I.PATALAKHA.

MECHANISM OF RESONANCE PRODUCTION IN FOUR PARTICLE EXCLUSIVE CHANNELS IN K- p INTERACTIONS AT 32-GeV/c

Bogolyubsky, M.Yu. ; Kotova, A.I. ; Levitsky, M.S. ; et al.

Yad.Fiz. 34 (1981) 1251, 1981.

Inspire Record 165498 DOI 10.17182/hepdata.41299

None

14 data tables

Table 1

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.

Table 2

No description provided.

Table 3

No description provided.