Bekrenev, V.S
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Search for first-generation scalar and vector leptoquarks

The D0 collaboration Abazov, V.M. ; Abbott, B. ; Abdesselam, A. ; et al.
Phys.Rev.D 64 (2001) 092004, 2001.
Inspire Record 557085 DOI 10.17182/hepdata.42922

We describe a search for the pair production of first-generation scalar and vector leptoquarks in the eejj and enujj channels by the D0 Collaboration. The data are from the 1992--1996 ppbar run at sqrt{s} = 1.8 TeV at the Fermilab Tevatron collider. We find no evidence for leptoquark production; in addition, no kinematically interesting events are observed using relaxed selection criteria. The results from the eejj and enujj channels are combined with those from a previous D0 analysis of the nunujj channel to obtain 95% confidence level (C.L.) upper limits on the leptoquark pair-production cross section as a function of mass and of beta, the branching fraction to a charged lepton. These limits are compared to next-to-leading-order theory to set 95% C.L. lower limits on the mass of a first-generation scalar leptoquark of 225, 204, and 79 GeV/c^2 for beta=1, 1/2, and 0, respectively. For vector leptoquarks with gauge (Yang-Mills) couplings, 95% C.L. lower limits of 345, 337, and 206 GeV/c^2 are set on the mass for beta=1, 1/2, and 0, respectively. Mass limits for vector leptoquarks are also set for anomalous vector couplings.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


Search for second generation leptoquark pairs in anti-p p collisions at S**(1/2) = 1.8-TeV

The D0 collaboration Abbott, B. ; Abolins, M. ; Abramov, V. ; et al.
Phys.Rev.Lett. 84 (2000) 2088-2093, 2000.
Inspire Record 508772 DOI 10.17182/hepdata.42087

We have searched for second generation leptoquark (LQ) pairs in the \mu\mu+jets channel using 94+-5 pb^{-1} of pbar-p collider data collected by the D0 experiment at the Fermilab Tevatron during 1993-1996. No evidence for a signal is observed. These results are combined with those from the \mu\nu+jets and \nu\nu+jets channels to obtain 95% confidence level (C.L.) upper limits on the LQ pair production cross section as a function of mass and $beta, the branching fraction of a LQ decay into a charged lepton and a quark. Lower limits of 200(180) GeV/c^2 for \beta=1(1/2) are set at the 95% C.L. on the mass of scalar LQ. Mass limits are also set on vector leptoquarks as a function of \beta.

1 data table
Table 1

No description provided.


Small angle muon and bottom quark production in p anti-p collisions at S**(1/2) = 1.8-TeV

The D0 collaboration Abbott, B. ; Abolins, M. ; Abramov, V. ; et al.
Phys.Rev.Lett. 84 (2000) 5478-5483, 2000.
Inspire Record 503949 DOI 10.17182/hepdata.42072

This Letter describes a measurement of the muon cross section originating from b quark decay in the forward rapidity range 2.4 < y(mu) < 3.2 in pbarp collisions at sqrt(s) = 1.8 TeV. The data used in this analysis were collected by the D0 experiment at the Fermilab Tevatron. We find that NLO QCD calculations underestimate b quark production by a factor of four in the forward rapidity region. A cross section measurement using muon+jet data has been included in this version of the paper.

3 data tables
Table 1

The forward muon cross section (per unit rapidity).

Table 2

The cross section for muons originating from b-quark decay.

Table 3

Integrated cross sections for muons originating from b-quark decay. The statistical and systematic errors are added in quadrature.


rivet Analysis
The b anti-b production cross-section and angular correlations in p anti-p collisions at S**(1/2) = 1.8-TeV

The D0 collaboration Abbott, B. ; Abolins, M. ; Abramov, V. ; et al.
Phys.Lett.B 487 (2000) 264-272, 2000.
Inspire Record 499943 DOI 10.17182/hepdata.42088

We present measurements of the b-bbar production cross section and angular correlations using the D0 detector at the Fermilab Tevatron p-pbar Collider operating at sqrt(s) = 1.8 TeV. The b quark production cross section for |y(b)|<1.0 and p_T(b)>6 GeV/c is extracted from single muon and dimuon data samples. The results agree in shape with the next-to-leading order QCD calculation of heavy flavor production but are greater than the central values of these predictions. The angular correlations between b and bbar quarks, measured from the azimuthal opening angle between their decay muons, also agree in shape with the next-to-leading order QCD prediction.

3 data tables
Table 1

No description provided.

Table 2

The errors are combinations of statistical and systematic uncertainties.

Table 3

The distribution of MU+ MU- azimuthal angle difference.


Search for first generation scalar leptoquark pairs in p anti-p collisions at S**(1/2) = 1.8-TeV

The D0 collaboration Abbott, B. ; Abolins, M. ; Acharya, Bannanje Sripath ; et al.
Phys.Rev.Lett. 80 (1998) 2051-2056, 1998.
Inspire Record 450538 DOI 10.17182/hepdata.42159

We have searched for first generation scalar leptoquark (LQ) pairs in the enu+jets channel using ppbar collider data (integrated luminosity= 115 pb^-1) collected by the DZero experiment at the Fermilab Tevatron during 1992-96. The analysis yields no candidate events. We combine the results with those from the ee+jets and nunu+jets channels to obtain 95% confidence level (CL) upper limits on the LQ pair production cross section as a function of mass and of beta, the branching fraction to a charged lepton. Comparing with the next-to-leading order theory, we set 95% CL lower limits on the LQ mass of 225, 204, and 79 GeV/c^2 for beta=1, 1/2, and 0, respectively.

1 data table
Table 1

The cross section values are extracted with the assumption that BR(LQ --> EQUARK) = 1/2.


Study of quasiexclusive neutral meson production in p N interactions at E(p) = 70-GeV in the deep fragmentation region.

The SPHINX collaboration Golovkin, S.V. ; Kozhevnikov, A.P. ; Kubarovsky, V.P. ; et al.
Z.Phys.A 359 (1997) 327-335, 1997.
Inspire Record 445405 DOI 10.17182/hepdata.40690

Quasiexclusive neutral meson production in pN-interactions is studied in experiments with the SPHINX facility operating in a proton beam from the IHEP accelerator (Ep=70 GeV). The cross sections and the parameters of the differential distributions for πo, ω, η and Ko production in the deep fragmentation region (xF > 0.79 ÷ 0.86) are presented. The results show that such proton quasiexclusive reactions with baryon exchange may be promising in searches for exotic mesons.

8 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

Data on the graph only.

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Investigation of the OZI selection rule for connected quark diagrams in hadronic processes. III: Diffractive Phi and omega production in p N collisions at 70-GeV.

The SPHINX collaboration Vavilov, D.V. ; Viktorov, V.A. ; Golovkin, S.V. ; et al.
Phys.Atom.Nucl. 59 (1996) 1186-1190, 1996.
Inspire Record 406501 DOI 10.17182/hepdata.40526

None

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

This ratio is corrected for the different phase space of the (P PHI) and (P OMEGA) system.


Further study of the quasi-exclusive reactions of the neutral mesons production by 70-GeV protons in p N interactions in the deep fragmentation region. (Revised version, in Russian)

The SPHINX collaboration Vavilov, D.V. ; Viktorov, V.A. ; Golovkin, S.V. ; et al.
IFVE-95-138, 1995.
Inspire Record 406502 DOI 10.17182/hepdata.40645

None

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Study of D*+ and search for D**0 production by neutrinos in BEBC

The Big Bubble Chamber Neutrino collaboration Asratvan, A.E. ; Aderholz, M. ; Ammosov, V.V. ; et al.
Z.Phys.C 68 (1995) 43-46, 1995.
Inspire Record 395454 DOI 10.17182/hepdata.47928

Data from BEBC experiments are combined to provide large statistics for neutrino interactions. ChargedD* mesons are produced in (1.22±0.25)% of neutrino and (1.01±0.31)% of antineutrino charged current interactions. The mean fraction of the hadronic laboratory energy taken by theD*+ in these events is 0.59±0.03±0.08. Less than 18% of all chargedD* mesons from (anti)neutrino interactions are found to be daughters ofD**0 (at the 90% confidence level).

4 data tables
Table 1

Mean fractional hadronic energy carried by the D*+- in the laboratory system.

Table 2

Mean value of the Bjorken scaling variable X.

Table 3

Rate of charged D* meson production per charged current neutrino interaction.

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The Search for heavy pentaquark exotic baryons with hidden strangeness in the p + N ---> (p Phi) + N and p + N ---> (Lambda (1520) K+) + N reactions at E(p) = 70-GeV

The SPHINX collaboration Dorofeev, V.A. ; Golovkin, S.V. ; Kozhevnikov, A.P. ; et al.
Phys.Atom.Nucl. 57 (1994) 227-237, 1994.
Inspire Record 385732 DOI 10.17182/hepdata.40688

None

2 data tables
Table 1

No description provided.

Table 2

The upper limits for production of EXOTIC-NUCLEON with narrow width (<50 MeV). Linear A-dependence of the cross section is assumed.