Haddock, R.P.
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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.


Observation of gamma gamma ---> phi rho0 and gamma gamma ---> phi omega

The ARGUS collaboration Albrecht, H. ; Ehrlichmann, H. ; Hamacher, T. ; et al.
Phys.Lett.B 332 (1994) 451-457, 1994.
Inspire Record 372451 DOI 10.17182/hepdata.45102

Two-photon production of the hadronic final states K + K − π + π − and K + K − π + π 0 π − has been studied using the ARGUS detector at the e + e − storage ring DORIS II at DESY. The cross sections of the reactions γγ → øϱ 0 and γγ → øω have been measured for the first time. In addition, angular distrubutions have been determined for the reaction γγ → øϱ 0 → K + K − π + π − .

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Measurement of Resonance Productions in the Reactions $\gamma \gamma \to \pi^0 \pi^0$ and $\gamma \gamma \to \pi^0 \eta$

The JADE collaboration Oest, T. ; Olsson, J. ; Allison, J. ; et al.
Z.Phys.C 47 (1990) 343-352, 1990.
Inspire Record 295180 DOI 10.17182/hepdata.15242

Resonance production in the γγ reactionse+e−→e+e+e−π0π0 ande+e−π0η has been studied with the JADE detector at PETRA. The decay widths into γγ of thef2(1270),a0(980) anda2(1320) were measured to be\(\Gamma _{\gamma \gamma } (f_2 (1270)) = 3.19 \pm 0.09_{ - 0.38}^{ + 0.22} \) Kev,Γλλ(a0(980))=0.28±0.04±0.10 KeV/BR(a0(980)→π0η) andΓλλ(a2(1320))=1.01±0.14±0.22KeV. For thef0(975) andf4(2050) upper limits of the widths were obtained,Γλλ(f0(975))<0.6 KeV, andΓλλ(f4(2050))<1.1 KeV, both at the 95% C.L. Assuming that the spin 0 background under thef2(1270) is small, thef2(1270) was found to be produced exclusively in a helicity 2 state. The helicity 0 contribution is <15% at the 95% C.L. The cross section forλλ→π0π0 in the mass range 2.0–3.5 GeV/c2 was measured for the first time. Since the cross section forλλ→π+π− is a factor ∼2 larger, ππ production in this range can be interpreted as taking place via isospin 0 production.

6 data tables
Table 1

Cross section for ABS(COS(THETA*)) < 0.3.

Table 2

Cross section under assumptions of spin 2, helicity 2 production.

Table 3

Cross section under assumption of spin 0 production.

More…

Exclusive Production of Proton Anti-proton Pairs in Photon-photon Collisions

The JADE collaboration Bartel, W. ; Becker, L. ; Cords, D. ; et al.
Phys.Lett.B 174 (1986) 350-356, 1986.
Inspire Record 231554 DOI 10.17182/hepdata.30246

Total and differential cross sections for exclusive production of proton-antiproton pairs in photon-photon collisions have been measured using the JADE detector at PETRA. The total cross section in the CM angular |cos θ ∗ | < 0.6 reaches a maximum value of 3.8 nb for a γγ invariant mass of W γγ = 2.25 GeV, and decreases rapidly for higher values of W γγ . In the range 2.0 GeV < W γγ < 2.6 GeV the angular distribution is not isotopic. The nucleons are preferentially emitted at large angles to the collision axis.

2 data tables
Table 1

Data read off graph.

Table 2

Data read off graph.


SEARCH FOR THE S MESON

Hamilton, R.P. ; Pun, T.P. ; Tripp, R.D. ; et al.
Phys.Rev.Lett. 44 (1980) 1182-1185, 1980.
Inspire Record 157724 DOI 10.17182/hepdata.20738

Total and annihilation cross sections for p¯p and p¯d have been measured over the momentum range 355-1066 MeV/c at closely spaced momenta and with good energy resolution. No evidence is seen for the narrow structure reported by other experiments in the vicinity of 500 MeV/c. The present measurements indicate a broader enhancement in this region, which, if interpreted as a resonance, would have a height of ∼ 3 mb and a width of ∼ 20 MeV. This structure appears only in the p¯p data.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


MEASUREMENT OF THE ANTI-P P CHARGE EXCHANGE CROSS-SECTION FROM 0.119-GEV/C TO 1.046-GEV/C

Hamilton, R.P. ; Pun, T.P. ; Tripp, R.D. ; et al.
Phys.Rev.Lett. 44 (1980) 1179-1181, 1980.
Inspire Record 157723 DOI 10.17182/hepdata.20730

Charge-exchange cross section for antiprotons on protons has been measured in closely spaced momentum intervals from 0.119 to 1.046 GeV/c. The regions of the reported resonances at 1936 and 2020 MeV were scanned in 10-MeV/c steps with a typical statistical error of ≈ 1% and an rms mass resolution of ± 1.5 MeV. No enhancements were observed.

1 data table
Table 1

ERROR ON INCIDENT MOMENTUM IS RMS RESOLUTION. LARGE UNCERTAINTIES EXIST IN THE MEAN INTERACTION MOMENTUM FOR THE TWO LOWEST MOMENTUM POINTS.