Jakubowski, Z.
Max results
Sort by Reverse order

Showing 10 of 1868 results

Date

rivet Analysis
Measurement of the decay of the Upsilon (1S) and Upsilon (2S) resonances to muon pairs

The Crystal Ball collaboration Kobel, M. ; Antreasyan, D. ; Bartels, H.W. ; et al.
Z.Phys.C 53 (1992) 193-206, 1992.
Inspire Record 306832 DOI 10.17182/hepdata.14771

Using the Crystal Ball detector at thee+e− storage ring DORIS II, we have measured the branching fraction to muon pairsBμμ of the Υ(

2 data tables match query
Table 1

Corrected cross section. Statistical and point to point systematic errors combined. Additional systematic error given above. The storage ring SQRT(S) has a 7.9 +- 0.2 MeV energy spread around the values given.

Table 2

Corrected cross section. Statistical and point to point systematic errors combined. Additional systematic error given above.The storage ring SQRT(S) has a 8.2 +- 0.3 MeV energy spread around the values given.


Measurement of the proton structure function F2 in e p scattering at HERA

The ZEUS collaboration Derrick, M. ; Krakauer, D. ; Magill, S. ; et al.
Phys.Lett.B 316 (1993) 412-426, 1993.
Inspire Record 357414 DOI 10.17182/hepdata.28804

This paper presents our first measurement of the F 2 structure function in neutral-current, deep inelastic scattering using the ZEUS detector at HERA, the ep colliding beam facility at DESY. The data correspond to an integrated luminosity of 24.7 nb −1 . Results are presented for data in range of Q 2 from 10 GeV 2 to 4700 GeV 2 and Bjorken x down to 3.0 × 10 −4 . The F 2 structure function increases rapidly as x decreases.

7 data tables match query
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

rivet Analysis
Determination of $\gamma (e e$) of the $\Upsilon$ (1s) and $\Upsilon$ (2s) Resonances and Measurement of R at $W=9$.39-{GeV}

The Crystal Ball collaboration Jakubowski, Z. ; Antreasyan, D. ; Bartels, H.W. ; et al.
Z.Phys.C 40 (1988) 49, 1988.
Inspire Record 261078 DOI 10.17182/hepdata.15560

Using the Crystal Ball detector operating at the DORIS II storage ring we have measured the leptonic partial widthsГeeof the Υ(1S) and Υ(2S) reson

1 data table match query
Table 1

No description provided.


First observation of the reaction gamma gamma ---> pi (2) ---> pi0 pi0 pi0

The Crystal Ball collaboration Antreasyan, D. ; Bartels, H.W. ; Besset, D. ; et al.
Z.Phys.C 48 (1990) 561-568, 1990.
Inspire Record 296523 DOI 10.17182/hepdata.15136

The Crystal Ball detector has been used at the DORIS II storage ring at DESY to study the reactionγγ→π0π0π0 in theπ0π0π0 invariant mass range from 850 MeV/c2 to 2600 MeV/c2. An enhancement around 1750 MeV/c2 is attributed to theπ2(1670) resonance. The observedπ0π0 invariant mass distribution and theπ0 angular distributions are consistent with those expected for the decay chainπ2→π0f2(1270)→π0π0π0. From our measurements we find the following resonance parameters: two photon partial width\(\Gamma _{\pi _2 }^{\gamma \gamma }= (1.41 \pm 0.23 \pm 0.28)keV\), massM(π2)=(1742±31±49)MeV/c2. and total width\(\Gamma _{\pi _2 }^{tot}= (236 \pm 49 \pm 36)MeV\).

2 data tables match query
Table 1

Data read from graph.

Table 2

Cross section times branching ratio to 3pi0 assuming the decay chain pi2 --> pi0f2 --> 3pi0.


rivet Analysis
Measurement of R in $e^+ e^-$ Annihilation for $\sqrt{s}$ Between 7.4-{GeV} and 9.4-{GeV}

The LENA collaboration Niczyporuk, B. ; Jakubowski, Z. ; Nowak, G. ; et al.
Z.Phys.C 15 (1982) 299, 1982.
Inspire Record 179431 DOI 10.17182/hepdata.16412

The rationR=σ(e+e−→hadrons)/σ(e+e−→ µ+ µ−) was measured with the LENA detector at DORIS in a scan between 7.40 and 7.48 GeV and between 8.67 and 9.43 GeV center of mass energies. Corrected for QED radiative effects,R is found to be constant with an average value ofR=3.37 ±0.06stat±0.23syst. No narrow resonances withΓee(Γhad/Γtot)⊗0.30 keV (95% C.L.) and no steps have been observed. Based on this value ofR, revised values for υ(1S) resonance parameters are presented.

3 data tables match query
Table 1

No description provided.

Table 2

No description provided.

Table 3

NUMERICAL VALUES GIVEN IN APPENDIX IN PREPRINT. STATISTICAL ERRORS ONLY.


rivet Analysis
Measurement of pi0 and eta meson production in e+ e- annihilation at s**(1/2) near 10-GeV

The Crystal Ball collaboration Bieler, Ch. ; Antreasyan, D. ; Bartels, H.W. ; et al.
Z.Phys.C 49 (1991) 225-234, 1991.
Inspire Record 297905 DOI 10.17182/hepdata.15082

We present a study of inclusive π0 and ŋ production ine+e− annihilation at

6 data tables match query
Table 1

Particle multiplicities in the continuum.

Table 2

Particle multiplicities in the UPSILON (1S).

Table 3

Inclusive pi0 spectra in the continuum.

More…

rivet Analysis
Formation of Delta (980) and A2 (1320) in Photon-photon Collisions

The Crystal Ball collaboration Antreasyan, D. ; Aschman, D. ; Besset, D. ; et al.
Phys.Rev.D 33 (1986) 1847, 1986.
Inspire Record 217547 DOI 10.17182/hepdata.23518

The reaction γγ→π0η has been investigated with the Crystal Ball detector at the DESY storage ring DORIS II. Formation of δ(980) and A2(1320) has been observed with γγ partial widths Γγγ(A2)=1.14±0.20±0.2 6 keV and Γγγ(δ)B(δ→πη)=0.19±0.07 −0.07+0.10 keV.

2 data tables match query
Table 1

No description provided.

Table 2

No description provided.


rivet Analysis
A Measurement of $\pi^0 \pi^0$ Production in Two Photon Collisions

The Crystal Ball collaboration Marsiske, H. ; Antreasyan, D. ; Bartels, H.W. ; et al.
Phys.Rev.D 41 (1990) 3324, 1990.
Inspire Record 294492 DOI 10.17182/hepdata.22923

The reaction e+e−→e+e−π0π0 has been analyzed using 97 pb−1 of data taken with the Crystal Ball detector at the DESY e−e+ storage ring DORIS II at beam energies around 5.3 GeV. For the first time we have measured the cross section for γγ→π0π0 for π0π0 mvariant masses ranging from threshold to about 2 GeV. We measure an approximately flat cross section of about 10 nb for W=mπ0π0<0.8 GeV, which is below 0.6 GeV, in good agreement with a theoretical prediction based on an unitarized Born-term model. At higher invariant masses we observe formation of the f2(1270) resonance and a hint of the f0(975). We deduce the following two-photon widths: Γγγ(f2(1270))=3.19±0.16±0.280.29 keV and Γγγ(f0(975))<0.53 keV at 90% C.L. The decay-angular distributions show the π0π0 system to be dominantly spin 0 for W<0.7 GeV and spin 2, helicity 2 in the f2(1270) region, with helicity 0 contributing at most 22% (90% C.L.).

2 data tables match query
Table 1

Statistical errors only.

Table 2

Statistical errors only.


Search for excited electrons using the ZEUS detector

The ZEUS collaboration Derrick, M. ; Krakauer, D. ; Magill, S. ; et al.
Phys.Lett.B 316 (1993) 207-218, 1993.
Inspire Record 355574 DOI 10.17182/hepdata.45106

This paper reports a search for excited electrons at the HERA electron-proton collider. In a sample corresponding to an integrated luminosity of 26 nb − , no evidence was found for any resonant state decaying into e − γ , ν W − or e − Z 0 . Limits on the coupling strength of an excited electron have been determined for masses between 45 and 225 GeV. This study also reports the observation of the wide-angle e γ Compton scattering process.

1 data table match query
Table 1

No description provided.


A Measurement of sigma(tot) (gamma p) at s**(1/2) = 210-GeV

The ZEUS collaboration Derrick, M. ; Krakauer, D. ; Magill, S. ; et al.
Phys.Lett.B 293 (1992) 465-477, 1992.
Inspire Record 339275 DOI 10.17182/hepdata.45171

The total photoproduction cross section is determined from a measurement of electroproduction with the ZEUS detector at HERA. The Q 2 values of the virtual photons are in the range 10 −7 < Q 2 <2×10 −2 GeV 2 . The γp total cross section in the γp centre of mass energy range 186–233 GeV is 154 ± 16 (stat.) ± 32 (syst.) μ b.

1 data table match query
Table 1

Scattered electron in range 10 to 16 GeV.