Date

MEASUREMENT OF n p ELASTIC SCATTERING AT HIGH-ENERGIES AND VERY SMALL MOMENTUM TRANSFERS

The Freiburg-Moscow collaboration Arefev, A. ; Babaev, A. ; Bamberger, A. ; et al.
Nucl.Phys.B 232 (1984) 365, 1984.
Inspire Record 190837 DOI 10.17182/hepdata.33883

The np elastic differential cross section has been measured for incident neutron momenta 100–400 GeV/ c in the | t | range 6 · 10 −6 − 5 · 10 −1 (GeV/ c ) 2 . The np data of this experiment provide a first direct measurement of the hadronic amplitude for | t | < 10 −2 (GeV/ c ) 2 , which is consistent with the extrapolations from higher | t | values. Our data for | t | < 10 −4 (GeV/ c ) 2 are consistent with a rise which can be attributed to Schwinger scattering, caused by the interaction of the neutron magnetic moment with the proton.

10 data tables

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INCLUSIVE K0(S) LAMBDA AND anti-LAMBDA PRODUCTION IN anti-p p INTERACTIONS AT 22.4-GeV/c

The Alma Ata-Dubna-Helsinki-Moscow-Prague-Tbilisi collaboration Batyunya, B.V. ; Boguslavsky, I.V. ; Gramenitsky, I.M. ; et al.
Z.Phys.C 25 (1984) 213, 1984.
Inspire Record 194651 DOI 10.17182/hepdata.2004

InclusiveKs0, Λ and\(\bar \Lambda\)-production has been investigated in\(\bar p\)p-interactions at 22.4 GeV/c. Total and topological cross sections and multiplicity characteristics of neutral strange particles have been determined. DifferentialKs0 and Λ-cross sections and also characteristics of annihilation processes with neutral kaon production have been studied. It is shown that the difference of the shapes of the invariantx-distributions forK-mesons in the fragmentation region for annihilation and non-annihilation processes can be described in the framework of the “dual” valon model, but not by considering the current (undressed) quark recombination mechanisms only. The polarization of Λ and\(\bar \Lambda\)-hyperons has been measured.

4 data tables

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EXISTENCE OF XI RESONANCES ABOVE 2-GEV

Jenkins, Charles M. ; Albright, John R. ; Diamond, R.N. ; et al.
Phys.Rev.Lett. 51 (1983) 951-954, 1983.
Inspire Record 195471 DOI 10.17182/hepdata.20475

Ξ*− production was studied in the reaction K−+p→K+slow+X− at 5 GeV/c. The slow K+ was electronically detected, while the X− was observed as a missing mass, thus allowing for observation of all Ξ* independent of decay mode. The observed Ξ states were Ξ(1320), Ξ(1530), Ξ(1820), Ξ(2030), Ξ(2250), Ξ(2370), and Ξ(2500). These data establish and confirm the existence of Ξ(2250) and indicate a peculiar production-cross-section behavior for the Ξ*(2370).

1 data table

UPPER LIMITS ARE 95 PCT CL.


A Measurement of the Branching Fraction of the Decay $\Upsilon$ (1s) $\to \tau^+ \tau^-$

The CLEO collaboration Giles, R. ; Hassard, J. ; Hempstead, M. ; et al.
Phys.Rev.Lett. 50 (1983) 877, 1983.
Inspire Record 188803 DOI 10.17182/hepdata.20525

The branching fraction for the decay of the ϒ(1S) into τ paris has been measured to be (3.4±0.4±0.4)%. This result agrees with the previously measured branching ratio of the decay into muon pairs.

2 data tables

VISIBLE CROSS SECTIONS IN THE PEAK.

No description provided.


ENERGY VARIATION OF THE ANALYZING POWER IN THE REACTION P (polarized) P ---> D PI+

Saha, A. ; Seth, K.K. ; Kielczewska, D. ; et al.
Phys.Rev.Lett. 51 (1983) 759-762, 1983.
Inspire Record 196398 DOI 10.17182/hepdata.20478

Precision measurements of the analyzing powers for the reaction ppol+p→d+π+ have been made at ≃ 550, 600, 650, 700, and 800 MeV. The data have been analyzed in terms of Legendre polynomials. It is found that excitation functions for both even and odd Legendre coefficients exhibit very similar resonant behaviors. It is concluded that the triplet amplitudes are as strongly dominated by the Δ(1232) as the well-known singlet amplitude, D21, and that the data do not exhibit any anomalous behavior suggestive of dibaryon resonances.

1 data table

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Inclusive $D$ and $D^*$ Production in $e^+ e^-$ Annihilation at 29-{GeV}

The HRS collaboration Ahlen, S.P. ; Akerlof, C. ; Baranko, G. ; et al.
Phys.Rev.Lett. 51 (1983) 1147, 1983.
Inspire Record 191536 DOI 10.17182/hepdata.20523

Inclusive production of (D0, D¯0) and D± mesons have been observed in e+e− annihilation at 29 GeV. The signals correspond to R values of R(D0+D¯0)=3.25±1.2 and R(D++D−)=1.35±0.6. D*± production is also observed via the process D*+→D0π+ and its charge conjugate. The D and D* production rates are compared.

7 data tables

EXTRAPOLATION TO ALL Z.

EXTRAPOLATION TO ALL Z.

EXTRAPOLATION TO ALL Z.

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A Measurement of the Leptonic Branching Ratios of the $\Upsilon$ (1s), $\Upsilon$ (2s), and $\Upsilon$ (3s)

The CLEO collaboration Andrews, D. ; Avery, P. ; Berkelman, Karl ; et al.
Phys.Rev.Lett. 50 (1983) 807, 1983.
Inspire Record 188805 DOI 10.17182/hepdata.20536

Using the CLEO detector at the Cornell Electron Storage Ring, the authors have measured the leptonic branching fractions, Bμμ, of the ϒ(1S), ϒ(2S), and ϒ(3S) to be 2.7±0.3±0.3%, 1.9±1.3±0.5%, and 3.3±1.3±0.7%, respectively. Combining these values of Bμμ with previous measurements of the leptonic widths of these resonances, the authors find the total widths of the ϒ(1S), ϒ(2S), and ϒ(3S) to be 48±4±4, 27±17±6, and 13±4±3 keV.

1 data table

No description provided.


Electroweak Effects in $e^+ e^- \to \mu^+ \mu^-$ at 29-{GeV}

Fernandez, E. ; Ford, William T. ; Read, Alexander L. ; et al.
Phys.Rev.Lett. 50 (1983) 1238, 1983.
Inspire Record 188749 DOI 10.17182/hepdata.20560

A measurement of the cross section for production of collinear muon pairs based upon a sample of about 3000 events observed in the MAC detector at the storage ring PEP is presented. From the angular asymmetry Aμμ=0.076±0.018 the axial-vector weak neutral coupling is found to be given by gAegAμ=0.31±0.08.

2 data tables

Data on non-collinearity and angular distribution.

Asymmetry measurement based on extrapolation of number of events to 4 PI acceptance.


CONFIRMATION OF DIP BUMP STRUCTURE IN BACKWARD PI- D ELASTIC SCATTERING: POSSIBLE EVIDENCE FOR DIBARYON RESONANCES

Akemoto, M. ; Baba, K. ; Endo, I. ; et al.
Phys.Rev.Lett. 50 (1983) 400-403, 1983.
Inspire Record 190884 DOI 10.17182/hepdata.20545

The backward differential cross section for π−−d elastic scattering has been measured at incident momenta between 420 and 1160 MeV/c. The data show two bumps at around 670 and 1100 MeV/c, two dips near 630 and 980 MeV/c, and a break at 550 MeV/c. The result of a phenonomenological fit is consistent with the existence of three dibaryon resonances in this energy region. A theoretical calculation of Kanai et al. agrees well with the data below 800 MeV/c, but the agreement becomes worse above 800 MeV/c.

2 data tables

STATISTICAL ERRORS ONLY.

SMALLER ANGLE DATA NOT GIVEN IN THE PAPER.


The Reactions $pp \to pp$ $\pi^+ \pi^-, K^+ p \to K^+ p$ $\pi^+ \pi^-$, $\pi^+ p \to \pi^+ p$ $\pi^+ \pi^-$ and $\pi^- p \to \pi^+ \pi^-$ at 147 GeV/c

Brick, D.H. ; Rudnicka, H. ; Shapiro, A.M. ; et al.
Z.Phys.C 19 (1983) 1-9, 1983.
Inspire Record 194363 DOI 10.17182/hepdata.16321

We have studied the reactionspp→ppπ+π-,K+p→K+pπ+π−π, π+p→ π+,pπ+π− and π−p →π+π− at 147 GeV/c using the 30-inch Fermilab hybrid system. All four reactions were detected with the same apparatus and analyzed in the same way. The energy dependence of the channel cross section was found to beAp−0.6+B for thepp reaction andAp−1+B for the other three. About 90% of the cross section at 147 GeV/c can be accounted for by either beam or target diffraction. Some of the remaining cross section may come from double Pomeron exchange reactions which we tried to isolate. We have tested the hypothesis of a factorizable Pomeron and our data indicates a violation of this hypothesis. We show that the 3π mass enhancement in the mass region 1.2–1.4 GeV is diffractively produced in the π± beam reactions. Fourprong, four-constraint and six-prong, four-constraint cross sections are reported.

6 data tables

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CROSS SECTIONS FOR DIFFRACTION DISSOCIATION OF BEAM. FEYNMAN X OF OUTGOING PROTON <-0.96.

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