HEPData Search

Showing 10 of 25 results

Delbrueck scattering at energies 140-MeV to 450-MeV.

Akhmadalev, S.Z. ; Kezerashvili, G.Ya. ; Klimenko, S.G. ; et al.

BUDKER-INP-1998-51, 1998.

Inspire Record 472470 DOI 10.17182/hepdata.50144

The differential cross section of Delbr\"{u}ck scattering is measured on a bismuth germanate $Bi_4Ge_3O_{12}$ target at photon energies $140 - 450 MeV$ and scattering angles $2.6 - 16.6 mrad$. A good agreement with the theoretical results, obtained exactly in a Coulomb field, is found.

1 data table

Table 1

Axis error includes +- 1.5/1.5 contribution (Error of measurement of the initial photons intensity).

E+ E- PAIR PRODUCTION BY A SYNCHROTRON RADIATION PHOTON ON A COUNTER BEAM ELECTRON. (IN RUSSIAN)

Blinov, A.E. ; Bondar, A.F. ; Bukin, A.D. ; et al.

Yad.Fiz. 45 (1987) 1008-1014, 1987.

Inspire Record 256613 DOI 10.17182/hepdata.17424

None

3 data tables

Table 1

Axis error includes +- 2/2 contribution (Error in counter efficiency determination).

Table 2

Electron momentum distribution.

Table 3

Electron-positron pairs mass distribution.

High Precision Measurement of the $\Upsilon$ Meson Mass

Artamonov, A.S. ; Baru, S.E. ; Blinov, A.E. ; et al.

Phys.Lett.B 118 (1982) 225, 1982.

Inspire Record 178785 DOI 10.17182/hepdata.37137

A high precision measurement of the υ-meson mass has been performed at the storage ring VEPP-4 using the MD-1 detector. The resonance depolarization method has been used for the absolute calibration of the beam energy that allowed to improve the accuracy of υ-mass measurement by a factor of ten. The following mass value has been obtained: M = 9459.7 ± 0.6 MeV.

1 data table

Table 1

No description provided.

Total cross-section of two photon production of hadrons

Baru, S.E. ; Beilin, M.V. ; Blinov, A.E. ; et al.

Z.Phys.C 53 (1992) 219-224, 1992.

Inspire Record 33675 DOI 10.17182/hepdata.14767

The total cross section for γγ→hadrons was measured as a function of the invariant massW of the system (1.25 to 4.25 GeV) at thee+e−-collider VEPP-4 with the detector MD-1. For the first time the data were obtained by detecting both scattered leptons with almost zero emission angles. The mean squared four momentum transfer 〈q2〉 is −0.005 GeV2, the rmsW resolution is 100–250 MeV. The data on the mean charged multiplicity 〈nC〉 are well described by the function 〈nC〉=(1.62 ±0.37)+(1.83±0.45)·ln(W(GeV)). TheW dependence of the total cross section is consistent with the theoretical prediction σ(nb)=240+270/W(GeV).

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Pion pair production in photon-photon collisions

Blinov, A.E. ; Blinov, V.E. ; Bondar, A.E. ; et al.

Z.Phys.C 53 (1992) 33-39, 1992.

Inspire Record 335707 DOI 10.17182/hepdata.14772

The process γγ→π+π− was measured using the detector MD-1 at VEPP-4. The two-photon reactionse+e−, μ+ μ− and π+ π− pair production were separated using scintillation counters, Cherenkov counters and shower-range chambers. A radiation widthГγγ(f2(1270))=3.1±0.35±0.35 keV was obtained.

1 data table

Table 1

Data read from graph.

The search for narrow resonances in the reaction e+ e- ---> hadrons at center-of-mass energy range between 7.23-GeV and 10.34-GeV

Blinov, A.E. ; Blinov, V.E. ; Beilin, M.V. ; et al.

Z.Phys.C 49 (1991) 239-243, 1991.

Inspire Record 316888 DOI 10.17182/hepdata.15083

The results of a search for narrow resonances ine+e− annihilation at centre-of-mass energies between 7.23 and 10.34 GeV are presented. The experiment was performed using the MD-1 detector at the VEPP-4 storage ring. The total luminosity integral of 16 pb−1 was taken. There is no evidence that new states exist. The upper limits on the leptonic widthΓee of possible resonances are less, by a factor of 10–80, than theΓee for the ϒ(1S) meson.

1 data table

Table 1

Average R value (excluding upsilon region).

rivet Analysis
Measurement of inclusive Lambda production in electron - positron interactions at the upsilon energies

Blinov, A.E. ; Blinov, V.E. ; Bondar, A.E. ; et al.

Z.Phys.C 62 (1994) 367-370, 1994.

Inspire Record 362599 DOI 10.17182/hepdata.14205

Using the MD-1 detector at the VEPP-4e+e− strorage ring we have measured the inclusive Λ and370-1 production rates in direct Γ(1S) decays

4 data tables

Table 1

Lambda x spectrum in direct upsilon(1S) decay.

Table 2

Lambda multiplicity in direct upsilon(1S) decays.

Table 3

Lambda multiplicity in surrounding continuum.

More…

rivet Analysis
The Measurement of R in e+ e- annihilation at center-of-mass energies between 7.2-GeV and 10.34-GeV

Blinov, A.E. ; Blinov, V.E. ; Bondar, A.E. ; et al.

Z.Phys.C 70 (1996) 31-38, 1996.

Inspire Record 364141 DOI 10.17182/hepdata.14321

The total cross section of the processe+e− →hadrons has been measured in the center-of-mass energy range between 7.25 and 10.34 GeV using the MD-1 detector at the VEPP-4 collider. The ratioR=σ(e+e− →hadrons)/σ(e+e− →μ+μ−) was found to be constant in this energy range with the average value of 3.58±0.02±0.14.

2 data tables

Table 1

Statistical errors only.

Table 2

Mean value of R in the range 7.25 to 10.34 GeV.

A measurement of the energy loss spectrum of 150-GeV muons in iron.

The RD34 collaboration Berger, Edmond L. ; Blair, R. ; Dawson, J. ; et al.

Z.Phys.C 73 (1997) 455-463, 1997.

Inspire Record 425292 DOI 10.17182/hepdata.47726

The energy loss spectrum of 150 GeV muons has been measured with a prototype of the ATLAS hadron calorimeter in the H8 beam of the CERN SPS. The differential probability dP/dv per radiation length of a fractional energy loss v = ΔEμ/Eμ has been measured in the range v = 0.01 ÷ 0.95; it is compared with the theoretical predictions for energy losses due to bremsstrahlung and production of electron—positron pairs or of energetic knock-on electrons. The integrated probability $\int_{0.01}^{0.95}({\rm d}P/{\rm d}v){\rm d}v$ is (1.610 ± 0.015stat ± 0.105syst) · 10−3 in agreement with the theoretical predictions 1.556 · 10−3 and 1.619 · 10−3. Agreement with theory is also found in two intervals of v where production of electron-positron pairs and knock-on electrons dominates. In the region of bremsstrahlung dominance (v = 0.12 ÷ 0.95) the measured integrated probability (1.160 ± 0.040stat ± 0.075syst) · 10−4 is in agreement with the theoretical value of 1.185 · 10−4, obtained using the Petrukhin and Shestakov description of the bremsstrahlung process. The same result is about 3.6 standard deviations (defined as the quadratic sum of statistical and systematic errors) lower than the theoretical prediction of 1.472 · 10−4, obtained using Tsai’s description of bremsstrahlung.

2 data tables

Table 1

Measured differential probability values DPROB/DNU for fractional energy loss. Only statistical errors are given.

Table 2

Integrated probability (DELTA(PROB)) per radiation length.