Akopian, A
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ASYMMETRY OF THE REACTION CROSS-SECTION FOR PI+ MESON PHOTOPRODUCTION ON HYDROGEN INDUCED BY POLARIZED PHOTONS IN THE RESONANCE ENERGY REGION. (IN RUSSIAN)

Abramian, L.O. ; Aganyants, Aleksandr O. ; Adamian, F.V. ; et al.
Yad.Fiz. 32 (1980) 128-132, 1980.
Inspire Record 159785 DOI 10.17182/hepdata.18977

None

2 data tables
Table 1

Axis error includes +- 10/10 contribution (DUE TO BEAM POLARIZATION UNCERTAINTY).

Table 2

Axis error includes +- 10/10 contribution (DUE TO BEAM POLARIZATION UNCERTAINTY).


PHOTOPRODUCTION OF PI- MESONS ON NEUTRONS INDUCED BY POLARIZED PHOTONS IN THE ENERGY INTERVAL 0.9-GEV - 1.65-GEV. (IN RUSSIAN)

Abramian, L.O. ; Aganyants, Aleksandr O. ; Adamian, F.V. ; et al.
Yad.Fiz. 32 (1980) 133-140, 1980.
Inspire Record 159786 DOI 10.17182/hepdata.18933

None

6 data tables
Table 1

Axis error includes +- 10./10. contribution (DUE TO BEAM POLARIZATION UNCERTAINTY).

Table 2

D(SIG)/D(OMEGA)=(D(SIG(O))/D(OMEGA)+D(SIG(C))/D(OMEGA))/2, WHERE (O) AND (C) DENOTES GAMMA POLARIZATION ORTHOGONAL AND COPLANAR TO THE REACTION PLANE.

Table 3

Axis error includes +- 10./10. contribution (DUE TO BEAM POLARIZATION UNCERTAINTY).

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ASYMMETRY OF THE REACTION gamma d ---> p n CROSS-SECTION WITH POLARIZED PHOTONS IN THE ENERGY REGION E (gamma) = 0.4-GeV - 0.7-GeV

Adamian, F.V. ; Arustamian, G.V. ; Galumian, P.I. ; et al.
EFI-505-48-81-YEREVAN, 1981.
Inspire Record 171117 DOI 10.17182/hepdata.18464

None

1 data table
Table 1

Axis error includes +- 10/10 contribution (ERROR IN VALUE OF PHOTON'S POLARIZATION).


CROSS-SECTION ASYMMETRY OF THE gamma n ---> pi- p REACTION BY POLARIZED PHOTONS IN THE THIRD AND FOURTH RESONANCE REGIONS

Adamian, F.V. ; Akopian, G.G. ; Galumian, P.I. ; et al.
EFI-722-37-84-YEREVAN, 1984.
Inspire Record 206944 DOI 10.17182/hepdata.18433

None

5 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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ASYMMETRY OF THE CROSS-SECTION FOR THE REACTION GAMMA D ---> PI0 D WITH LINEARLY POLARIZED GAMMA RAYS AT 500-MEV - 700-MEV AND AT A C.M. ANGLE THETA* (PI0) = 130-DEGREES

Adamian, F.V. ; Akopian, G.G. ; Vartapetian, G.A. ; et al.
JETP Lett. 39 (1984) 710-713, 1984.
Inspire Record 187231 DOI 10.17182/hepdata.16896

None

1 data table
Table 1

No description provided.


Limits on quark - lepton compositeness scales from dileptons produced in 1.8-TeV p anti-p collisions

The CDF collaboration Abe, F. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 79 (1997) 2198-2203, 1997.
Inspire Record 443871 DOI 10.17182/hepdata.42186

The dilepton mass spectrum in pp¯→l+l−+X interactions is studied using dielectrons (ee) and dimuons (μμ) in 110pb−1 of data collected with the Collider Detector at Fermilab. The data are consistent with standard model predictions. The mass spectrum, being a probe for new physics, is examined for new interactions of quarks and leptons from a common composite structure. Assuming a contact interaction with the conventional coupling g02/4π=1, limits on chiral quark-electron and quark-muon compositeness scales in the range of 2.5 to 4.2 TeV are obtained.

2 data tables
Table 1

Di-electron data and Standard Model event predicitions.

Table 2

Di-muon data and Standard Model event predicitions.


Double parton scattering in anti-p p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.D 56 (1997) 3811-3832, 1997.
Inspire Record 442259 DOI 10.17182/hepdata.42212

A strong signal for double parton (DP) scattering is observed in a 16pb−1 sample of p¯p→γ/π0+3jets+X data from the CDF experiment at the Fermilab Tevatron. In DP events, two separate hard scatterings take place in a single p¯p collision. We isolate a large sample of data (∼14000events) of which 53% are found to be DP. The process-independent parameter of double parton scattering, σeff, is obtained without reference to theoretical calculations by comparing observed DP events to events with hard scatterings in separate p¯p collisions. The result σeff=(14.5±1.7−2.3+1.7)mb represents a significant improvement over previous measurements, and is used to constrain simple models of parton spatial density. The Feynman x dependence of σeff is investigated and none is apparent. Further, no evidence is found for kinematic correlations between the two scatterings in DP events.

1 data table
Table 1

The cross section for Double Parton scattering comprised of scatterings A and B is written: SIG(DP) = SIG(A)*SIG(B)/CONST(NAME=SIG-EFF). The value of the constant SIG-EFF is measured here.


Search for new gauge bosons decaying into dileptons in anti-p p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 79 (1997) 2192-2197, 1997.
Inspire Record 442760 DOI 10.17182/hepdata.42195

We have searched for heavy neutral gauge bosons (Z′) in dielectron and dimuon decay modes using 110pb−1 of p¯p collisions at s=1.8TeV collected with the Collider Detector at Fermilab. We present a limit on the production cross section times branching ratio of a Z′ boson decaying into dileptons as a function of Z′ mass. For mass MZ′>600GeV/c2, the upper limit is 40 fb at 95% confidence level. We set the lower mass limits of 690, 590, 620, 595, 565, 630, and 600GeV/c2 for ZSM′, Zψ, Zη, Zχ, ZI, ZLR, and ZALRM, respectively.

1 data table
Table 1

M is the mass of ZPRIME boson. Sigma times branching ratio.


The mu tau and e tau decays of top quark pairs produced in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 79 (1997) 3585-3590, 1997.
Inspire Record 442202 DOI 10.17182/hepdata.42200

We present evidence for dilepton events from t tbar production with one electron or muon and one hadronically decaying tau lepton from the decay t tbar -> (l nu_l) (tau nu_tau) b bbar, (l=e, mu), using the Collider Detector at Fermilab (CDF). In a 109 pb~-1 data sample of p pbar collisions at sqrt(s) = 1.8 TeV we expect 1 signal event and a total background of 2 events; we observe 4 candidate events (2 e tau and 2 mu tau). Three of these events have jets identified as b candidates, compared to an estimated background of 0.28+-0.02 events.

1 data table
Table 1

Two complementary techniques for identifying TAU's are used (see text), one'track-based' (C=TRCK) and other 'calorimeter-based' (C=CALO).