Date

Collaboration Reset

Subject_areas

Measurement of inclusive electron cross-section in gamma gamma collisions at TRISTAN

The TOPAZ collaboration Iwasaki, M. ; Enomoto, R. ; Hayashii, H. ; et al.
Phys.Lett. B341 (1994) 99-108, 1994.
Inspire Record 378075 DOI 10.17182/hepdata.43778

We have studied open charm production in $\gamma \gamma$ collisions with the TOPAZ detector at the TRISTAN $e~{+}e~{-}$ collider. In this study, charm quarks were identified by electrons (and positrons) from semi-leptonic decays of charmed hadrons. The data corresponded to an integrated luminosity of 95.3 pb$~{-1}$ at a center-of-mass energy of 58 GeV. The results are presented as the cross sections of inclusive electron production in $\gamma \gamma$ collisions with an anti-tag condition, as well as the subprocess cross sections, which correspond to resolved-photon processes. The latter were measured by using a sub-sample with remnant jets. A comparison with various theoretical predictions based on direct and resolved-photon processes showed that our data prefer that with relatively large gluon contents in a photon at small $x (x \le 0.1)$, with the next-to-leading order correction, and with a charm-quark mass of 1.3 GeV.

2 data tables

The description of events with anti-tag, remnant-jet-tag, and no-tag are presnted in text.


Charge Asymmetry Measurement in $e^+ e^- \to \mu^+ \mu^-$ and $\tau^+ \tau^-$ Reactions at $\sqrt{s}=52$-{GeV}

The TOPAZ collaboration Adachi, I. ; Aihara, H. ; Dijkstra, H.B. ; et al.
Phys.Lett. B208 (1988) 319-323, 1988.
Inspire Record 251920 DOI 10.17182/hepdata.29948
6 data tables
More…

Measurement of the cross-section and forward - backward charge asymmetry for the b and c quark in e+ e- annihilation with inclusive muons at s**(1/2) = 58-GeV

The TOPAZ collaboration Inoue, Y. ; Miyamoto, A. ; Nakano, E. ; et al.
Eur.Phys.J. C18 (2000) 273-282, 2000.
Inspire Record 538542 DOI 10.17182/hepdata.43244

We have studied inclusive muon events using all the data collected by the TOPAZ detector at sqrt(s)=58 GeV with an integrated luminosity of 273pb-1. From 1328 inclusive muon events, we measured the ratio R_qq of the cross section for qq-bar production to the total hadronic cross section and forward-backward asymmetry A^q_FB for b and c quarks. The obtained results are R_bb = 0.13+-0.02(stat)+-0.01(syst), R_cc = 0.36+-0.05(stat)+-0.05(syst), A^b_FB = -0.20+-0.16(stat)+-0.01(syst) and A^c_FB = -0.17+-0.14(stat)+-0.02(syst), in fair agreement with a prediction of the standard model.

3 data tables

Differential cross section with respect to cos(theta).

Cross section deduced from a four-parameter fit.

Forward-backward asymmetry for a four-parameter fit.


Measurement of the jet width in $\gamma \gamma$ collisions and in $e^{+} e^{-}$ annihilation process at TRISTAN

The TOPAZ collaboration Adachi, K. ; Hayashii, H. ; Miyabayashi, K. ; et al.
Phys.Lett. B451 (1999) 256-266, 1999.
Inspire Record 494502 DOI 10.17182/hepdata.43768

The shape of jets produced in (quasi-) real photon-photon collisions as well as in e^+e^- annihilation process has been studied with a cone jet finding algorithm, using the data taken with the TOPAZ detector at the TRISTAN e^+e^- collider at an average center-of-mass energy of 58 GeV. The results are presented in terms of the jet width as a function of the jet transverse energy(E^{jet}_T) as well as a scaled transverse jet energy, x_T(=2E^{jet}_T/root(s)). The jet width narrows as E^{jet}_T increases; however, at the same value of E^{jet}_T the jet width in gamma-gamma collisions at TRISTAN is significantly narrower than that in gamma p collisions at HERA. By comparing our results with the data in other reactions, it has been shown that the jet width in gamma-gamma, gamma p, p\bar{p} collisions as well as the e^+e^- annihilation process has an approximate scaling behavior as a function of x_T.

2 data tables

The jet width is defined as the full width at the half maximum of the distribution of the transverse energy flow.

The jet width is defined as the full width at the half maximum of the distribution of the transverse energy flow.


Charged particle multiplicities of quark and gluon jets in e+ e- annihilation at TRISTAN

The TOPAZ collaboration Nakabayashi, K. ; Yamauchi, M. ; Abe, K. ; et al.
Phys.Lett. B413 (1997) 447-452, 1997.
Inspire Record 454183 DOI 10.17182/hepdata.28238
4 data tables

No description provided.

Multiplicity measured for events with a Thrust of 2/3. These are three-foldsymmetric events.

Mean charged particle multiplicity as function of -log(1-THRUST).

More…

Measurement of the forward - backward asymmetries for charm and bottom quark pair productions at S**(1/2) = 58-GeV with electron tagging

The TOPAZ collaboration Nakano, E. ; Enomoto, R. ; Iwasaki, M. ; et al.
Phys.Lett. B340 (1994) 135-142, 1994.
Inspire Record 39496 DOI 10.17182/hepdata.28532

We have measured, with electron tagging, the forward-backward asymmetries of charm- and bottom-quark pair productions at $\langle \sqrt{s} \rangle$=58.01GeV, based on 23,783 hadronic events selected from a data sample of 197pb$~{-1}$ taken with the TOPAZ detector at TRISTAN. The measured forward-backward asymmetries are $A_{FB}~c = -0.49 \pm 0.20(stat.) \pm 0.08 (sys.)$ and $A_{FB}~b = -0.64 \pm 0.35(stat.) \pm 0.13 (sys.)$, which are consistent with the standard model predictions.

1 data table

No description provided.


Measurements of alpha-s in e+ e- annihilation at TRISTAN

The TOPAZ collaboration Ohnishi, Y. ; Adachi, I. ; Fujimoto, J. ; et al.
Phys.Lett. B313 (1993) 475-482, 1993.
Inspire Record 361661 DOI 10.17182/hepdata.43784
4 data tables

No description provided.

No description provided.

The exact definition for Y23 see text.

More…

A Study of single photon production in e+ e- collisions at s**(1/2) = 58-GeV with the TOPAZ detector at TRISTAN

The TOPAZ collaboration Abe, T. ; Fujii, K. ; Sugiyama, A. ; et al.
Phys.Lett. B361 (1995) 199-206, 1995.
Inspire Record 406593 DOI 10.17182/hepdata.28440
1 data table

No description provided.


Observation of excess lambda (anti-lambda) production in two photon processes at TRISTAN

The TOPAZ collaboration Enomoto, R. ; Abe, K. ; Abe, T. ; et al.
Phys.Lett. B347 (1995) 179-186, 1995.
Inspire Record 392056 DOI 10.17182/hepdata.38362

We have carried out inclusive measurements of $\Lambda(\overline{\Lambda})$ production in two-photon processes at TRISTAN. The mean $\sqrt{s}$ was 58 GeV and the integrated luminosity was 265 pb$~{-1}$. Inclusive $\Lambda (\overline{\Lambda})$ samples were obtained under such conditions as no-electron, anti-electron, and remnant-jet tags. The data were compared with theoretical calculations. The measured cross sections are two-times larger than the leading-order theoretical predictions, suggesting the necessity of next-to-leading-order Monte-Carlo generator.

9 data tables

No-tag data.

Anti-electron tag data.

Remnant-jet tag with VDM subtraction data.

More…

Measurement of the total hadronic cross-section and determination of gamma - Z interference in e+ e- annihilation

The TOPAZ collaboration Miyabayashi, K. ; Adachi, I. ; Fujii, K. ; et al.
Phys.Lett. B347 (1995) 171-178, 1995.
Inspire Record 381777 DOI 10.17182/hepdata.38368
1 data table

Total hadronic cross section after QED corrections.


K0 (anti-K0) production in two photon processes at TRISTAN

The TOPAZ collaboration Enomoto, R. ; Abe, K. ; Abe, T. ; et al.
Phys.Lett. B341 (1994) 238-244, 1994.
Inspire Record 377805 DOI 10.17182/hepdata.38385

We have carried out an inclusive measurement of $K~0(\overline{K~0})$ production in two-photon processes at TRISTAN. The mean $\sqrt{s}$ was 58 GeV and the integrated luminosity was 199 pb$~{-1}$. High-statistics $K_s$ samples were obtained under such conditions as no-, anti-electron, and remnant-jet tags. The remnant-jet tag, in particular, allowed us, for the first time, to measure the cross sections separately for the resolved-photon and direct processes.

6 data tables

No tag data.

Anti-electron tag data.

Remnant-jet tag with VDM subtraction data.

More…

Measurement of the D*+- cross-section using a soft pion analysis in two photon processes

The TOPAZ collaboration Enomoto, R. ; Abe, K. ; Abe, T. ; et al.
Phys.Lett. B328 (1994) 535-546, 1994.
Inspire Record 372139 DOI 10.17182/hepdata.38387

The differential cross section of $d\sigma(e~+e~-\rightarrow e~+e~-D~{*\pm}X)/dP_T$ was measured using a soft-pion analysis of $D~{*\pm}\rightarrow \pi_s~\pm D~0(\overline{D~0})$ at TRISTAN. The average $\sqrt{s}$ was 58.1 GeV and the integrated luminosity used in this analysis was 198 pb$~{-1}$, respectively.

4 data tables

Soft pion cross section.

D*+- cross section from the soft-pion analysis.

Previous `full reconstruction' measurement from Enomoto et al. (to be published).

More…

Measurement of the photon structure function F2(gamma) and jet production at TRISTAN

The TOPAZ collaboration Muramatsu, K. ; Hayashii, H. ; Noguchi, S. ; et al.
Phys.Lett. B332 (1994) 477-487, 1994.
Inspire Record 373856 DOI 10.17182/hepdata.38377
7 data tables

No description provided.

No description provided.

No description provided.

More…

Measurement of the D*+- cross-section in a two photon process

The TOPAZ collaboration Enomoto, R. ; Iwasaki, M. ; Muramatsu, K. ; et al.
Phys.Rev. D50 (1994) 1879-1883, 1994.
Inspire Record 357776 DOI 10.17182/hepdata.38389

We have measured the inclusive $D~{*\pm}$ production cross section in a two-photon collision at the TRISTAN $e~+e~-$ collider. The mean $\sqrt{s}$ of the collider was 57.16 GeV and the integrated luminosity was 150 $pb~{-1}$. The differential cross section ($d\sigma(D~{*\pm})/dP_T$) was obtained in the $P_T$ range between 1.6 and 6.6 GeV and compared with theoretical predictions, such as those involving direct and resolved photon processes.

2 data tables

Numerical values supplied by R. Enomoto.

No description provided.


Measurement of the inclusive cross-section of jets in $\gamma \gamma$ interactions at TRISTAN

The TOPAZ collaboration Hayashii, H. ; Miyamoto, A. ; Iwasaki, M. ; et al.
Phys.Lett. B314 (1993) 149-158, 1993.
Inspire Record 355918 DOI 10.17182/hepdata.28845
3 data tables

No description provided.

No description provided.

No description provided.


Measurement of the forward - backward asymmetry of e+ e- ---> c anti-c at s**(1/2) = 57.95-GeV

The TOPAZ collaboration Nakano, E. ; Enomoto, R. ; Abe, K. ; et al.
Phys.Lett. B314 (1993) 471-476, 1993.
Inspire Record 361662 DOI 10.17182/hepdata.28846
1 data table

No description provided.


Search for a narrow resonance in e+ e- collisions between E(cm) = 58-GeV and 60-GeV

The TOPAZ collaboration Abe, K. ; Adachi, I. ; Awa, S. ; et al.
Phys.Lett. B304 (1993) 373-380, 1993.
Inspire Record 353845 DOI 10.17182/hepdata.28918
4 data tables

No description provided.

No description provided.

No description provided.

More…

Measurement of inclusive particle spectra and test of MLLA prediction in e+ e- annihilation at s**(1/2) = 58-GeV

The TOPAZ collaboration Itoh, R. ; Yamauchi, M. ; Yamaguchi, A. ; et al.
Phys.Lett. B345 (1995) 335-342, 1995.
Inspire Record 381900 DOI 10.17182/hepdata.38345

Inclusive momentum spectra are measured for all charged particles and for each of $\pi~{\pm}$, $K~{\pm}$, $K~0/\overline{K~0}$, and $p/\overline{p}$ in hadronic events produced via $e~+e~-$ annihilation at $\sqrt{s}$=58GeV . The measured spectra are compared with QCD predictions based on the modified leading log approximation(MLLA). The MLLA model reproduces the measured spectra well. The energy dependence of the peak positions of the spectra is studied by comparing the measurements with those at other energies. The energy dependence is also well described by the MLLA model.

3 data tables

Errors include both statistical and systematic errors.

Errors include both statistical and systematic errors.

Statistical errors only.


An experimental study of muon pair production in tagged two photon interactions

The TOPAZ collaboration Hayashii, H. ; Nishioka, H. ; Abe, T. ; et al.
Phys.Lett. B279 (1992) 422-428, 1992.
Inspire Record 332576 DOI 10.17182/hepdata.29228
1 data table

No description provided.


Experimental study of b quark jets in e+ e- annihilation at TRISTAN

The TOPAZ collaboration Nagai, K. ; Enomoto, R. ; Abe, T. ; et al.
Phys.Lett. B278 (1992) 506-510, 1992.
Inspire Record 333342 DOI 10.17182/hepdata.29230
4 data tables

No description provided.

No description provided.

Mean values of jet properties for b-jet sample.

More…

Cross-sections and charge asymmetries for e+ e- ---> mu+ mu- and e+ e- ---> tau+ tau- reactions at s**(1/2) = 52-GeV - 61.4-GeV

The TOPAZ collaboration Howell, B. ; Koltick, D.S. ; Tauchi, T. ; et al.
Phys.Lett. B291 (1992) 206-212, 1992.
Inspire Record 336076 DOI 10.17182/hepdata.29061
6 data tables

No description provided.

Additional 4.6 pct systematic uncertainty.

Additional 4.4 pct systematic uncertainty.

More…

Studies of e+ e- ---> gamma gamma and gamma-gamma-gamma reactions

The TOPAZ collaboration Shimozawa, K. ; Fujimoto, J. ; Abe, T. ; et al.
Phys.Lett. B284 (1992) 144-150, 1992.
Inspire Record 339575 DOI 10.17182/hepdata.29177
11 data tables

No description provided.

No description provided.

No description provided.

More…

Measurements of b quark forward - backward charge asymmetry and axial vector coupling using inclusive muons in e+ e- annihilation at s**(1/2) = 52-GeV - 61.4-Gev

The TOPAZ collaboration Shimonaka, A. ; Fujii, K. ; Miyamoto, A. ; et al.
Phys.Lett. B268 (1991) 457-464, 1991.
Inspire Record 319034 DOI 10.17182/hepdata.29343
4 data tables

Observed differential cross section.

No description provided.

No description provided.

More…

Charge asymmetry of hadronic events in $e^{+} e^{-}$ annihilation at $\sqrt{s}$ = 57.9-GeV

The TOPAZ collaboration Adachi, I. ; Anazawa, M. ; Doser, M. ; et al.
Phys.Lett. B255 (1991) 613-622, 1991.
Inspire Record 314203 DOI 10.17182/hepdata.29492
2 data tables

No description provided.

No description provided.


Measurement of the Total Hadronic Cross-sections in e$^{+} $e$^{-}$ Annihilation and Determination of the Standard Model Parameters

The TOPAZ collaboration Adachi, I. ; Doser, M. ; Enomoto, R. ; et al.
Phys.Lett. B234 (1990) 525-533, 1990.
Inspire Record 283003 DOI 10.17182/hepdata.29733
2 data tables

No description provided.

No description provided.