HEPData Search

The reaction e + e − → τ + τ − has been measured using the high resolution spectrometer at PEP. The angular distribution shows a forward-backward asymmetry of −(6.1±2.3±0.5)%, corresponding to an axial-vector coupling if g a τ g a e = 0.28 ±0.11± 0.03, in good agreement with the standard model of electroweak interactions. The measured cross section yields ifR ττ = 1.10± 0.03±0.04, consistent with QED and giving QED cutoff parameters of Λ + >92 GeV and Λ − >246 GeV at 95% C.L.

4 data tables

Table 1

Comparison of total tau pair cross section with O(alpha**3) QED prediction.

Table 2

Corrected for acceptance backgraound, and O(alpha**3) radiative effects.

Table 3

Forward-backward asymmetry based on fit to angular distributions.

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Studies of $\bar{p} p \to \bar{n} n$ and $\bar{n} p$ Annihilation at Incident Momenta of 700-{MeV}/$c$ and 760-{MeV}/$c$

The Bombay-Chandigarh-Jammu-Tokyo collaboration Banerjee, S. ; Ganguli, S.N. ; Gurtu, A. ; et al.

Z.Phys.C 28 (1985) 163, 1985.

Inspire Record 217418 DOI 10.17182/hepdata.1974

Results are presented on the charge exchange reaction$\bar pp \to \bar nn$ and$\bar np$ annihilations from bubble chamber exposures to antiproton beam of momenta 700 and 760 MeV/c. The differential cross section of$\bar pp \to \bar nn$ shows a forward spike followed by a clear dip bump structure. Total annihilation cross section of$\bar np$ for average$\bar n$ momentum of 700 MeV/c has been evaluated to be 55.4±2.2 mb. The multiplicity, Feynmanx andpT2 distributions for inclusive charged pions in$\bar pp$ and$\bar np$ annihilations are found to be similar. The emission of charged pions from$\bar np$ annihilations are found to be consistent with thermodynamic models with temperature ∼110 MeV.

11 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Results of the experiments from the neutral detector at the VEPP-2M storage ring in the energy region 2E$_{0}$ = 1.05 - 1.40 GeV

Dolinski, S.I. ; Druzhinin, V P ; Dubrovin, M S ; et al.

IYAF-85-98, 1985.

Inspire Record 1393709 DOI 10.17182/hepdata.982

None

4 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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INCLUSIVE K0(S), LAMBDA AND anti-LAMBDA PRODUCTION IN 360-GeV/c p p INTERACTIONS USING THE EUROPEAN HYBRID SPECTROMETER

The EHS-RCBC collaboration Asai, M. ; Bugg, W.M. ; Bailly, J.L. ; et al.

IFVE-85-65, 1985.

Inspire Record 214009 DOI 10.17182/hepdata.10425

None

17 data tables

Table 1

Axis error includes +- 0.0/0.0 contribution (?////).

Table 2

Axis error includes +- 0.0/0.0 contribution (?////).

Table 3

Axis error includes +- 0.0/0.0 contribution (?////).

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LEADING PROTON AND ANTI-PROTON DISTRIBUTIONS IN PROTON NUCLEUS AND ANTI-PROTON NUCLEUS INTERACTIONS

Bailey, R. ; Blanar, G. ; Bosman, M. ; et al.

Z.Phys.C 29 (1985) 1-8, 1985.

Inspire Record 221966 DOI 10.17182/hepdata.15989

We present a study of leading protons and antiprotons inp-nucleus and$\bar p$-nucleus on Be, Cu, Ag, W, and U targets. The experiment was performed at the CERN-SPS at a beam energy of 120 GeV. For all targets a suppression of secondary antiprotons with respect to protons is observed. The difference between the$\bar p$ andp spectra increases with decreasing χ-values and the effect is stronger for heavier nuclei. The features of the data are qualitatively consistent with multiple-collisions modesls. The data are analysed in terms of a dual parton model which gives a satisfactory description of leadingp and$\bar p$ spectra.

1 data table

Table 1

No description provided.

DIFFERENCES BETWEEN PROTON AND PI- INDUCED PRODUCTION OF THE CHARMONIUM CHI STATES

Bauer, Daniel A. ; Graff, T.L. ; Lukens, P.T. ; et al.

Phys.Rev.Lett. 54 (1985) 753-756, 1985.

Inspire Record 216287 DOI 10.17182/hepdata.20333

The charmonium χ states are observed in both π− and p Be interactions near 200 GeV/c via their radiative decay into J/ψ. The χ(3510) and χ(3555) are produced with roughly equal cross sections in π− collisions while the χ(3555) dominates in p collisions. Simple gluon fusion can account for χ production with incident protons but additional mechanisms are needed for incident π−.

1 data table

Table 1

No description provided.

MASSES, WIDTHS, AND LEPTONIC WIDTHS OF THE HIGHER UPSILON RESONANCES

Lovelock, D.M.J. ; Horstkotte, J.E. ; Klopfenstein, C. ; et al.

Phys.Rev.Lett. 54 (1985) 377-380, 1985.

Inspire Record 215716 DOI 10.17182/hepdata.20355

The masses, total widths, and leptonic widths of three triplet s-wave bb¯ states ϒ(4S), ϒ(5S), and ϒ(6S) are determined from measurements of the e+e− annihilation cross section into hadrons for 10.55<W<11.25 GeV. The resonances are identified from potential model results and their properties are obtained with the help of a simplified coupled-channels calculation. We find M(4S)=10.577 GeV, Γ(4S)=25 MeV, Γee(4S)=0.28 keV; M(5S)=10.845 GeV, Γ(5S)=110 MeV, Γee(5S)=0.37 keV; M(6S)=11.02 GeV, Γ(6S)=90 MeV, Γee(6S)=0.16 keV.

1 data table

Table 1

VISIBLE CROSS SECTION INTO HADRONS.

INCLUSIVE PRODUCTION OF OMEGA- AND ANTI-OMEGA+ BY K0(L) CARBON INTERACTIONS IN THE ENERGY RANGE 80-GEV/C - 280-GEV/C

Hartouni, Edward P. ; Atiya, M.S. ; Holmes, Stephen D. ; et al.

Phys.Rev.Lett. 54 (1985) 628-630, 1985.

Inspire Record 216075 DOI 10.17182/hepdata.20341

We have measured the total cross sections of Ω− and Ω¯+ forward (xF>~0) inclusive production in KL0-carbon interactions in the range EK0=80 to 280 GeV to be 3.5±1.4 and 2.4±1.0 μb, respectively. We observe that the xF distributions for both of these states are increasing from xF=0 to xF≈0.6. The p⊥2 distributions are described as an exponential function in p⊥ with an average p⊥2 of 0.540 GeV2/c2.

1 data table

Table 1

No description provided.

EXCLUSIVE PRODUCTION OF K+ K- pi+ pi- IN PHOTON-PHOTON COLLISIONS

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Armitage, J.C. ; et al.

Phys.Rev.Lett. 54 (1985) 2564, 1985.

Inspire Record 213402 DOI 10.17182/hepdata.20345

We report a measurement of the reaction γγ→K+K−π+π− in both tagged and untagged events at PEP. The cross section rises with invariant γγ mass to about 15 nb at 2 GeV and falls slowly at higher masses. We find clear evidence for the processes γγ→φπ+π− and γγ→K*0(892)Kπ. Upper limits (95% C.L.) of 1.5 and 5.7 nb in the mass range from 1.7 to 3.7 GeV are obtained for φρ0 and K*0K¯*0 production, respectively.

8 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

Untagged sample, (non-resonant).

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ANALYSIS OF THE REACTION PI- P ---> PI0 ETA N AT 40-GEV/C BEAM MOMENTUM.

Measurement of the Reaction $e^+ e^- \to \tau^+ \tau^-$ at $\sqrt{s}=29$-{GeV}

Studies of $\bar{p} p \to \bar{n} n$ and $\bar{n} p$ Annihilation at Incident Momenta of 700-{MeV}/$c$ and 760-{MeV}/$c$

Results of the experiments from the neutral detector at the VEPP-2M storage ring in the energy region 2E$_{0}$ = 1.05 - 1.40 GeV

INCLUSIVE K0(S), LAMBDA AND anti-LAMBDA PRODUCTION IN 360-GeV/c p p INTERACTIONS USING THE EUROPEAN HYBRID SPECTROMETER

LEADING PROTON AND ANTI-PROTON DISTRIBUTIONS IN PROTON NUCLEUS AND ANTI-PROTON NUCLEUS INTERACTIONS

DIFFERENCES BETWEEN PROTON AND PI- INDUCED PRODUCTION OF THE CHARMONIUM CHI STATES

MASSES, WIDTHS, AND LEPTONIC WIDTHS OF THE HIGHER UPSILON RESONANCES

INCLUSIVE PRODUCTION OF OMEGA- AND ANTI-OMEGA+ BY K0(L) CARBON INTERACTIONS IN THE ENERGY RANGE 80-GEV/C - 280-GEV/C

EXCLUSIVE PRODUCTION OF K+ K- pi+ pi- IN PHOTON-PHOTON COLLISIONS