Results from a search for a neutral scalar produced in association with a W boson in $p\bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
1996.
Inspire Record 424540 DOI 10.17182/hepdata.43005
1 data table match query

The cross section limits are set using two methods. The first (C=COUNT) is a simple counting experiment, and the second (C=SHAPE) use the shape of the dij et mass spectrum input to a likelihood fit.


Study of the $Z Z \gamma$ and $Z \gamma \gamma$ couplings in $Z (\nu \nu) \gamma$ production

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 78 (1997) 3640-3645, 1997.
Inspire Record 440634 DOI 10.17182/hepdata.42214

We have measured the ZZ-gamma and Z-gamma-gamma couplings by studying p-bar p -> (missing ET) gamma + X events at sqrt(s)=1.8 TeV with the D0 detector at the Fermilab Tevatron Collider. This first study of hadronic Z-gamma production in the neutrino decay channel gives the most stringent limits on anomalous couplings available. A fit to the transverse energy spectrum of the photon in the candidate event sample, based on a data set corresponding to an integrated luminosity of 13.1 pb~(-1), yields 95% CL limits on the anomalous CP-conserving ZZ-gamma couplings of |h~Z_(30)|<0.9, |h~Z_(40)|<0.21, for a form-factor scale Lambda = 500 GeV. Combining these results with our previous measurement using Z -> ee and mu-mu yields the limits:|h~Z_(30)|<0.8, |h~Z_(40)|<0.19 (Lambda = 500 GeV) and |h~Z_(30)|<0.4, |h~Z_(40)|<0.06 (Lambda = 750 GeV).

1 data table match query

CONST(NAME=SCALE) is the model parameter, used in the modification of the couplings as follows: h = hi0/(1 + M(gamma Z)**2/CONT(NAME=SCALE)**2)**n. See article for details.. The data with Z --> lepton+ lepton- is taken from S.Abachi, PRL 75, 1028.


Search for additional neutral gauge bosons

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Lett.B 385 (1996) 471-478, 1996.
Inspire Record 421554 DOI 10.17182/hepdata.42253

We have searched for a heavy neutral gauge boson, Z ′, using the decay channel Z ′ → ee . The data were collected with the DØ detector at the Fermilab Tevatron during the 1992–1993 p p collider run at s =1.8 TeV from an integrated luminosity of 15±1 pb −1 . Limits are set on the cross section times brancing ratio for the process p p → Z′ → ee as a function of the Z ′ mass. We exclude the existence of a Z ′ of mass less than 490 GeV/c 2 , assuming a Z ′ with the same coupling strengths to quarks and leptons as the standard model Z boson.

1 data table match query

No description provided.


The Azimuthal decorrelation of jets widely separated in rapidity

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 77 (1996) 595-600, 1996.
Inspire Record 416886 DOI 10.17182/hepdata.42315

This study reports the first measurement of the azimuthal decorrelation between jets with pseudorapidity separation up to five units. The data were accumulated using the D\O\ detector during the 1992--1993 collider run of the Fermilab Tevatron at $\sqrt{s}=$ 1.8 TeV. These results are compared to next--to--leading order (NLO) QCD predictions and to two leading--log approximations (LLA) where the leading--log terms are resummed to all orders in $\alpha_{\scriptscriptstyle S}$. The final state jets as predicted by NLO QCD show less azimuthal decorrelation than the data. The parton showering LLA Monte Carlo {\small HERWIG} describes the data well; an analytical LLA prediction based on BFKL resummation shows more decorrelation than the data.

3 data tables match query

Distribution of the pseudorapidity interval of the two jets at the extremes of pseudorapidity. Data are read from the graph and the errors are statistical only.

Normalized distributions of the azimuthal angle difference of the two jets at the extremes of pseudorapidity in 3 pseudorapididity difference intervals. Data are read from the graph and the errors are statistical only.

The correlation between the PHI and ETARAP difference distributions as used in the analysis.Data are read from the graph and the errors include the statiucal and un-correlated systematic errors added in quadrature.


$J/\psi$ production in $p \bar{p}$ collisions at $\sqrt{s}$ = 1.8-TeV

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Lett.B 370 (1996) 239-248, 1996.
Inspire Record 415417 DOI 10.17182/hepdata.42319

We have studied J ψ production in p p collisions at s = 1.8 TeV with the DØ detector at Fermilab using μ + μ − data. We have measured the inclusive J ψ production cross section as a function of J ψ transverse momentum, p T . For the kinematic range p T > 8 GeV/ c and |η| < 0.6 we obtain σ(p p → J ψ + X) · Br ( J ψ → μ + μ − ) = 2.08 ± 0.17( stat) ± 0.46(syst) nb. Using the muon impact parameter we have estimated the fraction of J ψ mesons coming from B meson decays to be f b = 0.35 ± 0.09(stat)±0.10(syst) and inferred the inclusive b production cross section. From the information on the event topology the fraction of nonisolated J ψ events has been measured to be f nonisol = 0.64 ± 0.08(stat)±0.06(syst). We have also obtained the fraction of J ψ events resulting from radiative decays of χ c states, f χ = 0.32 ± 0.07(stat)±0.07(syst). We discuss the implications of our measurements for charmonium production processes.

5 data tables match query

No description provided.

No description provided.

Integrated b-quark production cross section.

More…

Search for anomalous $W W$ and $W Z$ production in $p\bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 77 (1996) 3303-3308, 1996.
Inspire Record 419962 DOI 10.17182/hepdata.42290

We present results from a search for anomalous WW and WZ production in ppbar collisions at sqrt(s) = 1.8 TeV. We used ppbar->evjjX events observed during the 1992-1993 run of the Fermilab Tevatron collider, corresponding to an integrated luminosity of 13.7 +- 0.7 pb^-1. A fit to the transverse momentum spectrum of the W boson yields direct limits on the CP-conserving anomalous WWgamma and WWZ coupling parameters of -0.9 &lt; delta kappa &lt; 1.1 (with lambda = 0) and -0.6 &lt; lambda &lt; 0.7 (with delta kappa = 0) at the 95% confidence level, for a form factor scale Lambda = 1.5 TeV, assuming that the WWgamma and WWZ coupling parameters are equal.

1 data table match query

CONST(NAME=SCALE) is the model parameter, used in the modification of the couplings as follows: g = g0/(1 + M(gamma Z)**2/CONT(NAME=SCALE)**2)**n.


Isolated photon cross-section in the central and forward rapidity regions in $p\bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 77 (1996) 5011-5015, 1996.
Inspire Record 417044 DOI 10.17182/hepdata.42312

A measurement of the cross section for production of single, isolated photons is reported for transverse energies in the range of 10-125 GeV, for two regions of pseudorapidity, |\eta|<0.9 and 1.6<|\eta|<2.5. The data represent 12.9 pb-1 of integrated luminosity accumulated in p-pbar collisions at sqrt{s} = 1.8 TeV and recorded with the D0 detector at the Fermilab Tevatron Collider.

2 data tables match query

Numerical values supplied by J. Womersley.

Numerical values supplied by J. Womersley.


Search for scalar leptoquark pairs decaying to electrons and jets in $\bar{p}p$ collisions

The D0 collaboration Abbott, B. ; Abolins, M. ; Acharya, Bannanje Sripath ; et al.
Phys.Rev.Lett. 79 (1997) 4321-4326, 1997.
Inspire Record 446155 DOI 10.17182/hepdata.42172

We have searched for the pair production of first generation scalar leptoquarks in the eejj channel using the full data set (123 pb-1) collected with the D0 detector at the Fermilab Tevatron during 1992--1996. We observe no candidates with an expected background of approximately 0.4 events. Comparing the experimental 95% confidence level upper limit to theoretical calculations of the cross section with the assumption of a 100% branching fraction to eq, we set a lower limit on the mass of a first generation scalar leptoquark of 225 GeV/c^2. The results of this analysis rule out the interpretation of the excess of high Q^2 events at HERA as leptoquarks which decay exclusively to eq.

1 data table match query

No description provided.


Measurement of dijet angular distributions and search for quark compositeness

The D0 collaboration Abbott, B. ; Abolins, M. ; Acharya, Bannanje Sripath ; et al.
Phys.Rev.Lett. 80 (1998) 666-671, 1998.
Inspire Record 445265 DOI 10.17182/hepdata.42185

We have measured the dijet angular distribution in $\sqrt{s}$=1.8 TeV $p\bar{p}$ collisions using the D0 detector. Order $\alpha^{3}_{s}$ QCD predictions are in good agreement with the data. At 95% confidence the data exclude models of quark compositeness in which the contact interaction scale is below 2 TeV.

1 data table match query

No description provided.


Limits on $W W Z$ and $W W \gamma$ couplings from $p\bar{p} \to e \nu j j X$ events at $\sqrt{s} = 1.8$ TeV

The D0 collaboration Abbott, B. ; Abolins, M. ; Acharya, Bannanje Sripath ; et al.
Phys.Rev.Lett. 79 (1997) 1441-1446, 1997.
Inspire Record 443148 DOI 10.17182/hepdata.42199

We present limits on anomalous WWZ and WW-gamma couplings from a search for WW and WZ production in p-bar p collisions at sqrt(s)=1.8 TeV. We use p-bar p -> e-nu jjX events recorded with the D0 detector at the Fermilab Tevatron Collider during the 1992-1995 run. The data sample corresponds to an integrated luminosity of 96.0+-5.1 pb~(-1). Assuming identical WWZ and WW-gamma coupling parameters, the 95% CL limits on the CP-conserving couplings are -0.33<lambda<0.36 (Delta-kappa=0) and -0.43<Delta-kappa<0.59 (lambda=0), for a form factor scale Lambda = 2.0 TeV. Limits based on other assumptions are also presented.

1 data table match query

CONST(NAME=SCALE) is the model parameter, used in the modification of the couplings as follows: g = g0/(1 + M(gamma Z)**2/CONT(NAME=SCALE)**2)**n.


Studies of Topological Distributions of the Three- and Four-Jet Events in $\bar{p}p$ Collisions at $\sqrt{s}=1800$ GeV with the D0 Detector

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.D 53 (1996) 6000-6016, 1996.
Inspire Record 399364 DOI 10.17182/hepdata.11124

The global topologies of inclusive three-- and four--jet events produced in $\pp$ interactions are described. The three-- and four--jet events are selected from data recorded by the D\O\ detector at the Tevatron Collider operating at a center--of--mass energy of $\sqrt{s} = 1800$ GeV. The measured, normalized distributions of various topological variables are compared with parton--level predictions of tree--level QCD calculations. The parton--level QCD calculations are found to be in good agreement with the data. The studies also show that the topological distributions of the different subprocesses involving different numbers of quarks are very similar and reproduce the measured distributions well. The parton shower Monte Carlo generators provide a less satisfactory description of the topologies of the three-- and four--jet events.

29 data tables match query

The estimated systematic uncertainty is 6 PCT.

The estimated systematic uncertainty is 6 PCT.

The estimated systematic uncertainty is 6 PCT.

More…

Jet Production via Strongly-Interacting Color-Singlet Exchange in $p\bar{p}$ Collisions

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 76 (1996) 734-739, 1996.
Inspire Record 400107 DOI 10.17182/hepdata.42348

A study of the particle multiplicity between jets with large rapidity separation has been performed using the D\O\ detector at the Fermilab Tevatron $p\bar{p}$ Collider operating at $\sqrt{s}=1.8$\,TeV. A significant excess of low-multiplicity events is observed above the expectation for color-exchange processes. The measured fractional excess is $1.07 \pm 0.10({\rm stat})~{ + 0.25}_{- 0.13}({\rm syst})\%$, which is consistent with a strongly-interacting color-singlet (colorless) exchange process and cannot be explained by electroweak exchange alone. A lower limit of $0.80\%$ (95\% C.L.) is obtained on the fraction of dijet events with color-singlet exchange, independent of the rapidity gap survival probability.

1 data table match query

'Opposite-side' jets with a large pseudorapidity separation. A cone algorithm with radius R = sqrt(d(etarap)**2+d(phi)**2)=0.7 is used for jet funding. Double negative binomial distribution (NBD) is used to parametrize the color-exchange component of the opposite-side multiplicity distribution betweeb jets. A result of extrapolation to the zero multiplicity point. Quoted systematic error is a result of combining in quadrature of the systematic errors described above.


Second generation leptoquark search in $p\bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 75 (1995) 3618-3623, 1995.
Inspire Record 397099 DOI 10.17182/hepdata.42373

We report on a search for second generation leptoquarks with the D\O\ detector at the Fermilab Tevatron $p\overline{p}$ collider at $\sqrt{s}$ = 1.8 TeV. This search is based on 12.7 pb$~{-1}$ of data. Second generation leptoquarks are assumed to be produced in pairs and to decay into a muon and quark with branching ratio $\beta$ or to neutrino and quark with branching ratio $(1-\beta)$. We obtain cross section times branching ratio limits as a function of leptoquark mass and set a lower limit on the leptoquark mass of 111 GeV/c$~{2}$ for $\beta = 1 $ and 89 GeV/c$~{2}$ for $\beta = 0.5 $ at the 95\%\ confidence level.

1 data table match query

The cross section times branching ratios.


Measurement of the $Z Z \gamma$ and $Z \gamma \gamma$ couplings in $p\bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 75 (1995) 1028, 1995.
Inspire Record 394245 DOI 10.17182/hepdata.42374

We have directly measured the ZZ-gamma and Z-gamma-gamma couplings by studying p pbar --> l+ l- gamma + X, (l = e, mu) events at the CM energy of 1.8$TeV with the D0 detector at the Fermilab Tevatron Collider. A fit to the transverse energy spectrum of the photon in the signal events, based on the data set corresponding to an integrated luminosity of 13.9 pb~-1 ($13.3 pb~-1) for the electron (muon) channel, yields the following 95% confidence level limits on the anomalous CP-conserving ZZ-gamma couplings: -1.9 < h~Z_30 < 1.8 (h~Z_40 = 0), and -0.5 < h~Z_40 < 0.5 (h~Z_30 = 0), for a form-factor scale Lambda = 500 GeV. Limits for the Z-gamma-gamma$ couplings and CP-violating couplings are also discussed.

1 data table match query

The anomalous CP-conserving Z Z GAMMA. CONST(NAME=SCALE) is the model parameter, used in the modification of the couplings as follows: h = hi0/(1 + M(gamma Z)**2/CONT(NAME=SCALE)**2)**n. See article for details.


Transverse energy distributions within jets in $p\bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Lett.B 357 (1995) 500-508, 1995.
Inspire Record 398175 DOI 10.17182/hepdata.42372

The distribution of the transverse energy in jets has been measured in p p collisions at s =1.8 TeV TeV using the DØ detector at Fermilab. This measurement of the jet shape is made as a function of jet transverse energy in both the central and forward rapidity regions. Jets are shown to narrow both with increasing transverse energy and with increasing rapidity. Next-to-leading order partonic QCD calculations are compared to the data. Although the calculations qualitatively describe the data, they are shown to be very dependent on renormalization scale, parton clustering algorithm, and jet direction definition and they fail to describe the data in all regions consistently.

6 data tables match query

No description provided.

No description provided.

No description provided.

More…

$W$ and $Z$ boson production in $p \bar{p}$ collisions at $\sqrt{s}$ = 1.8-TeV

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 75 (1995) 1456-1461, 1995.
Inspire Record 395459 DOI 10.17182/hepdata.42368

The inclusive cross sections times leptonic branching ratios for W and Z boson production in PbarP collisions at Sqrt(s)=1.8 TeV were measured using the D0 detector at the Fermilab Tevatron collider: Sigma_W*B(W->e, nu) = 2.36 +/- 0.07 +/- 0.13 nb, Sigma_W*B(W->mu,nu) = 2.09 +/- 0.23 +/- 0.11 nb, Sigma_Z*B(Z-> e, e) = 0.218 +/- 0.011 +/- 0.012 nb, Sigma_Z*B(Z->mu,mu) = 0.178 +/- 0.030 +/- 0.009 nb. The first error is the combined statistical and systematic uncertainty, and the second reflects the uncertainty in the luminosity. For the combined electron and muon analyses we find: [Sigma_W*B(W->l,nu)]/[Sigma_Z*B(Z->l,l)] = 10.90 +/- 0.49. Assuming Standard Model couplings, this result is used to determine the width of the W boson: Gamma(W) = 2.044 +/- 0.093 GeV.

1 data table match query

The second DSYS error is due to luminosity.


Top quark search with the D0 1992 - 1993 data sample

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.D 52 (1995) 4877-4919, 1995.
Inspire Record 398425 DOI 10.17182/hepdata.42468

We present results on the search for the top quark in pp¯ collisions at √s =1.8 TeV with an integrated luminosity of 13.5±1.6 pb−1. We have considered tt¯ production in the standard model using electron and muon dilepton decay channels (tt¯→eμ+jets, ee+jets, and μμ+jets) and single-lepton decay channels (tt¯→e+jets and μ+jets) with and without tagging of b quark jets. An analysis of these data optimized for top quark masses below 140 GeV/c2 gives a lower top quark mass limit of 128 GeV/c2. An analysis optimized for higher top quark masses yields 9 events with an expected background of 3.8±0.9. If we assume that the excess is due to tt¯ production, and assuming a top quark mass of 180 GeV/c2, we obtain a cross section of 8.2±5.1 pb.

1 data table match query

No description provided.


Observation of the top quark

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 74 (1995) 2632-2637, 1995.
Inspire Record 393099 DOI 10.17182/hepdata.42452

The DO collaboration reports on a search for the Standard Model top quark in pbar-p collisions at Sqrt(s)=1.8TeV at the Fermilab Tevatron, with an integrated luminosity of approximately 50pb-1. We have searched for t-tbar production in the dilepton and single-lepton decay channels, with and without tagging of b-quark jets. We observed 17 events with an expected background of 3.8+/-0.6 events. The probability for an upward fluctuation of the background to produce the observed signal is 2.0E-6 (equivalent to 4.6 standard deviations). The kinematic properties of the excess events are consistent with top quark decay. We conclude that we have observed the top quark and measure its mass to be 199~+19_21 (stat.)+/- 22 (syst.)GeV/c**2 and its production cross section to be 6.4 +/- 2.2 pb.

1 data table match query

Cross section refers to top quark mass equal 199. (+19, -21, +- 22) GeV.


A Study of the strong coupling constant using $W + {\rm jets}$ processes

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 75 (1995) 3226-3231, 1995.
Inspire Record 394610 DOI 10.17182/hepdata.42454

The ratio of the number of W+1 jet to W+0 jet events is measured with the D0 detector using data from the 1992–93 Tevatron Collider run. For the W→eν channel with a minimum jet ET cutoff of 25 GeV, the experimental ratio is 0.065±0.003stat±0.007syst. Next-to-leading order QCD predictions for various parton distributions agree well with each other and are all over 1 standard deviation below the measurement. Varying the strong coupling constant αs in both the parton distributions and the partonic cross sections simultaneously does not remove this discrepancy.

1 data table match query

Two values of ALPHA_S corresponds the two different parton distribution functions (pdf) used in extraction of ALPHA_S from the ratio. The dominant systematic error is from the jet energy scale uncertainty.


Inclusive muon and $B$ quark production cross-sections in $p \bar{p}$ collisions at $\sqrt{s}$ = 1.8-TeV

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
(1995), 1995.
Inspire Record 398709 DOI 10.17182/hepdata.43027

We have calculated the double and triple differential cross sections for electron ejection with energy of 14.6 eV in single ionization of H2 by 75 keV proton impact. A molecular version of the continuum distorted wave-eikonal initial state approach is applied, where the interaction between the projectile and the residual molecular ion is considered more properly than in previous applications of the method. For triple differential cross sections, the present results are in better agreement with the experimental data than those of other descriptions when large momentum transfer values are considered. For double differential cross sections the experimental data are reproduced quite well for both coherent and incoherent proton beams.

2 data tables match query

No description provided.

No description provided.


Measurement of the upsilon cross-section at D0 using dimuons

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
1995.
Inspire Record 397850 DOI 10.17182/hepdata.43051
1 data table match query

Cross section times the branching ratio for decay into dimuons.


Studies of gauge boson pair production and trilinear couplings

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.D 56 (1997) 6742-6778, 1997.
Inspire Record 441947 DOI 10.17182/hepdata.42213

The gauge boson pair production processes Wg, WW, WZ, and Zg were studied using pbarp collisions corresponding to an integrated luminosity of ~14 pb-1 at a center-of-mass energy of sqrt(s) = 1.8 TeV. Analysis of Wg prod with subsequent W boson decay to lv (l=e,mu) is reported, including a fit to the pT spectrum of the photons which leads to limits on anomalous WWg couplings. A search for WW prod with subsequent decay to l-lbar-v-vbar (l=e,mu) is presented leading to an upper limit on the WW prod cross section and limits on anomalous WWg and WWZ couplings. A search for high pT W bosons in WW and WZ prod is described, where one W boson decays to an ev and the second W boson or the Z boson decays to two jets. A maximum likelihood fit to the pT spectrum of W bosons resulted in limits on anomalous WWg and WWZ couplings. A combined fit to the three data sets which provided the tightest limits on anomalous WWg and WWZ couplings is also described. Limits on anomalous ZZg and Zgg couplings are presented from an analysis of the photon ET spectrum in Zg events in the decay channels (ee, mu-mu, and v-vbar) of the Z boson.

1 data table match query

CONST(NAME=SCALE) is the model parameter, used in the modification of the couplings as follows: h = hi0/(1 + M(gamma Z)**2/CONT(NAME=SCALE)**2)**n. See article for details.


Search for diphoton events with large missing transverse energy in $p\bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 78 (1997) 2070-2074, 1997.
Inspire Record 427309 DOI 10.17182/hepdata.42245

A search for signals of new physics has been carried out in the channel p pbar -> gamma gamma + ETmiss. This signature is expected in various recently proposed supersymmetric (SUSY) models. We observe 842 events with two photons having transverse momentum ET(g) > 12 GeV and pseudorapidity |eta(g)| < 1.1. Of these, none have missing transverse energy (ETmiss) in excess of 25 GeV. The distribution of ETmiss is consistent with that of the expected background. We therefore set limits on production cross sections for selectron, sneutrino and neutralino pairs, decaying into photons. The limits range from about 400 fb to 1 pb depending on the sparticle masses. A general limit of 185 fb (95% C.L.) is set on sigma.B(pbar p -> gamma gamma ETmiss + X) where ET(g) > 12 GeV, |eta(g)| < 1.1, and ETmiss > 25 GeV.

1 data table match query

$INVISIBLE means ET(missing).


Search for a fourth generation charge -1/3 quark via flavor changing neutral current decay

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 78 (1997) 3818-3823, 1997.
Inspire Record 426498 DOI 10.17182/hepdata.42251

We report on a search for pair production of a fourth generation charge -1/3 quark (b') in pbar p collisions at sqrt(s) = 1.8 TeV at the Fermilab Tevatron using an integrated luminosity of 93 pb^-1. Both quarks are assumed to decay via flavor changing neutral currents (FCNC). The search uses the signatures gamma + 3 jets + mu-tag and 2 gamma + 2 jets. We see no significant excess of events over the expected background. We place an upper limit on the production cross section times branching fraction that is well below theoretical expectations for a b' quark decaying exclusively via FCNC for b' quark masses up to m(Z) + m(b).

3 data tables match query

Cross section times branching fraction for the gamma+3jets channel.

Cross section times branching fraction for the 2gamma+2jets channel.

No description provided.


Search for top squark pair production in the dielectron channel

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.D 57 (1998) 589-593, 1998.
Inspire Record 427311 DOI 10.17182/hepdata.41662

This report describes the first search for top squark pair production in the channel stop_1 stopbar_1 -> b bbar chargino_1 chargino_1 -> ee+jets+MEt using 74.9 +- 8.9 pb~-1 of data collected using the D0 detector. A 95% confidence level upper limit on sigma*B is presented. The limit is above the theoretical expectation for sigma*B for this process, but does show the sensitivity of the current D0 data set to a particular topology for new physics.

1 data table match query

Data are extracted from the figure. Sigma*Br.