HEPData Search

Showing 10 of 18 results

Event-by-event fluctuations of average transverse momentum in central Pb + Pb collisions at 158-GeV per nucleon.

The NA49 collaboration Appelshäuser, H. ; Bächler, J. ; Bailey, S.J. ; et al.

Phys.Lett.B 459 (1999) 679-686, 1999.

Inspire Record 498247 DOI 10.17182/hepdata.41648

We present first data on event-by-event fluctuations in the average transverse momentum of charged particles produced in Pb+Pb collisions at the CERN SPS. This measurement provides previously unavailable information allowing sensitive tests of microscopic and thermodynamic collision models and to search for fluctuations expected to occur in the vicinity of the predicted QCD phase transition. We find that the observed variance of the event-by-event average transverse momentum is consistent with independent particle production modified by the known two-particle correlations due to quantum statistics and final state interactions and folded with the resolution of the NA49 apparatus. For two specific models of non-statistical fluctuations in transverse momentum limits are derived in terms of fluctuation amplitude. We show that a significant part of the parameter space for a model of isospin fluctuations predicted as a consequence of chiral symmetry restoration in a non-equilibrium scenario is excluded by our measurement.

1 data table

Table 1

Studied YRAP (for PI's) is in a region of 4 TO 5.5.

Final Results on $\mu e$ Pair Production in Neutrino Interactions With Chamber Skat Filled With Freon

Ammosov, V.V. ; Ermolaev, V.I. ; Ivanilov, A.A. ; et al.

Z.Phys.C 40 (1988) 493, 1988.

Inspire Record 263220 DOI 10.17182/hepdata.15559

We present the final results from the search for μe pairs produced in neutrino interactions using the freon filled bubble chamber SKAT. The rate of μ−e+ pairs to charged current events above the charm threshold is$R_{\mu ^ -e^ +}= (4.8 \pm 1.1)10^{ - 3} $. Assuming charm particle production to be the origin of the positron we calculate$R_{\Lambda _c^ +}= (6.2 \pm 3.1)10^{ - 2} $ andRD=(2.8±0.9)10−2. We observe no considerable μ−e− pair production above the background. In the regionEv>3 GeV,pμ,e>1.0 GeV/c andpμ>pe we find with a 90% confidence level the limit$R_{\mu ^ -e^ -}< 1.7 10^{ - 4} $.

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

OBSERVATION OF PARTICLE COLLECTIVE FLUX IN THE COLLISIONS OF 4.1-A-GeV/c Ne-22 WITH Ag, Br EMULSION NUCLEI

The Alma Ata-Bucharest-Leningrad-Dubna-Dushanbe-Yerevan-Kosice-Cracow- Leningrad-Moscow-Rez-Tashkent-Tbilisi-Ulan Bator collaboration Bannik, B.P. ; Krasnov, S.A. ; Tolstov, K.D. ; et al.

Z.Phys.A 329 (1988) 341-347, 1988.

Inspire Record 253534 DOI 10.17182/hepdata.16604

None

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Observation of $\mu^- e^-$ Events in Neutrino Interactions at 3-{GeV} to 30-{GeV}

Ammosov, V.V. ; Ermolaev, V.I. ; Ivanilov, A.A. ; et al.

Phys.Lett.B 189 (1987) 245-248, 1987.

Inspire Record 240344 DOI 10.17182/hepdata.40796

The production of μ − e − pairs is studied in interactions of neutrinos with nuclei of heavy freon in the SKAT bubble chamber experiment. A rate of μ − e − pairs to charged current interactions of R μ − e − =(2.5± 1.4 4.3 )×10 −4 is found at an average neutrino energy of 10 GeV. The ratio μ − e − / μ − e + comes out to be μ − e − / μ − e + = 0.12± 0.08 0.22 .

1 data table

Table 1

No description provided.

Production of $\mu^- e^+$ Pairs in Neutrino interactions in the SKAT Bubble Chamber Experiment

Ammosov, V.V. ; Ivanilov, A.A. ; Ivanov, P.V. ; et al.

Z.Phys.C 35 (1987) 329, 1987.

Inspire Record 238675 DOI 10.17182/hepdata.40896

The production of μe-pairs is studied in interactions of neutrinos with nuclei of heavy freon in the SKAT bubble chamber experiment. A rate of μ−e+ to charged current interactions above the charm threshold of$R^{\mu ^ -e^ +}= (4.6 \pm 1.2) \cdot 10^{ - 3} $ is found. The properties of the observed μ−e+ events can be well described by assuming them to originate from the semileptonic decay of quasielastic produced charmed baryonsΛc and inclusive charmedD-meson production. The rates for these reactions are found to be (6.7±3.5)×10−2 and (2.5±0.9)×10−2, respectively. A total charmed particle production rate of (9.2±3.6)×10−2 is calculated.

2 data tables

Table 1

No description provided.

Table 2

No description provided.