Cross-section for forward J / psi production in p anti-p collisions at S = 1.8-TeV

The CDF collaboration Acosta, D. ; Affolder, T. ; Akimoto, H. ; et al.
Phys.Rev.D 66 (2002) 092001, 2002.
Inspire Record 603674 DOI 10.17182/hepdata.22217

The inclusive cross section for J/ψ production times the branching ratio B(J/ψ→μ+μ−) has been measured in the forward pseudorapidity region: B×dσ[p¯+p→J/ψ(pT>10GeV/c,2.1<|η|<2.6)+X]/dη=192±9(stat)±29(syst)pb. The results are based on 74.1±5.2pb−1 of data collected by the CDF Collaboration at the Fermilab Tevatron Collider. The measurements extend earlier measurements of the D0 Collaboration to higher pTJ/ψ. In the kinematic range where the experiments partially overlap, these data are in good agreement with previous measurements.

2 data tables

The integrated cross section for J/PSI --> MU+ MU- decay.

Cross section as a function of PT. Statistical errors only.


Branching ratio measurements of exclusive B+ decays to charmonium with the Collider Detector at Fermilab

The CDF collaboration Acosta, D. ; Affolder, T. ; Akimoto, H. ; et al.
Phys.Rev.D 66 (2002) 052005, 2002.
Inspire Record 588090 DOI 10.17182/hepdata.56734

We report on measurements of the branching ratios of the decays B+→χc10(1P)K+ and B+→J/ψK+π+π−, where χc10(1P)→J/ψγ and J/ψ→μ+μ− in pp¯ collisions at s=1.8TeV. Using a data sample from an integrated luminosity of 110pb−1 collected by the Collider Detector at Fermilab we measure the branching ratios to be BR(B+→χc10(1P)K+)=15.5±5.4(stat)±1.5(syst)±1.3(br)×10−4 and BR(B+→J/ψK+π+π−)=6.9±1.8(stat)±1.1(syst)±0.4(br)×10−4 where (br) is due to the finite precision on BR(B+→J/ψK+), BR(χc10(1P)→J/ψγ) is used to normalize the signal yield, and (syst) encompasses all other systematic uncertainties.

2 data tables

Branching ratio for B+ decay in chi_c1(1P) and K+ Last error is due to finite precision on the branching ratio for chi_c1(1P) --> J/psi photon.

Branching ratio for B+ decay in J/psi K+ pi+ pi- Last error is due to finite precision on the branching ratio for B+ --> J/psi K+.


Comparison of the isolated direct photon cross-sections in p anti-p collisions at s**(1/2) = 1.8-TeV and s**(1/2) = 0.63-TeV

The CDF collaboration Acosta, D. ; Affolder, T. ; Akimoto, H. ; et al.
Phys.Rev.D 65 (2002) 112003, 2002.
Inspire Record 581379 DOI 10.17182/hepdata.42882

We have measured the cross sections $d^2\sigma/dP_T d\eta$ for production of isolated direct photons in \pbarp collisions at two different center-of-mass energies, 1.8 TeV and 0.63 TeV, using the Collider Detector at Fermilab (CDF). The normalization of both data sets agree with the predictions of Quantum Chromodynamics (QCD) for photon transverse momentum ($P_T$) of 25 GeV/c, but the shapes versus photon $P_T$ do not. These shape differences lead to a significant disagreement in the ratio of cross sections in the scaling variable $x_T (\equiv 2P_T/\sqrt{s}$). This disagreement in the $x_T$ ratio is difficult to explain with conventional theoretical uncertainties such as scale dependence and parton distribution parameterizations.

2 data tables

The 1800 GeV isolated photon cross section. The systematic (DSYS) uncertainties include the normalisation uncertainties which are 100 PCT correlated bin tobin.

The 630 GeV isolated photon cross section. The systematic (DSYS) uncertainties include the normalisation uncertainties which are 100 PCT correlated bin to bin.


Upsilon production and polarization in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Acosta, D. ; Affolder, T. ; Akimoto, H. ; et al.
Phys.Rev.Lett. 88 (2002) 161802, 2002.
Inspire Record 569269 DOI 10.17182/hepdata.42894

We report on measurements of the ϒ(1S), ϒ(2S), and ϒ(3S) differential cross sections (d2σ/dpTdy)|y|<0.4, as well as on the ϒ(1S) polarization in pp¯ collisions at s=1.8TeV using a sample of 77±3pb−1 collected by the collider detector at Fermilab. The three resonances were reconstructed through the decay ϒ→μ+μ−. The measured angular distribution of the muons in the ϒ(1S) rest frame is consistent with unpolarized meson production.

4 data tables

The differential cross section times the branching ratio into mu+ mu- for UPSILON(1S) production.

The differential cross section times the branching ratio into mu+ mu- for UPSILON(2S) production. The first DSYS error is the systematic error due to the polarization of the UPSILON which is shown seperately from the other systematic errors.

The differential cross section times the branching ratio into mu+ mu- for UPSILON(3S) production. The first DSYS error is the systematic error due to the polarization of the UPSILON which is shown seperately from the other systematic errors.

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Measurement of the B+ total cross-section and B+ differential cross-section d sigma / dp(T) in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Acosta, D. ; Affolder, T. ; Akimoto, H. ; et al.
Phys.Rev.D 65 (2002) 052005, 2002.
Inspire Record 567345 DOI 10.17182/hepdata.42889

We present measurements of the B+ meson total cross section and differential cross section $d\sigma/ dp_T$. The measurements use a $98\pm 4$ pb^{-1} sample of $p \bar p$ collisions at $\sqrt{s}=1.8$ TeV collected by the CDF detector. Charged $B$ meson candidates are reconstructed through the decay $B^{\pm} \to J/\psi K^{\pm}$ with $J/\psi\to \mu^+ \mu^-$. The total cross section, measured in the central rapidity region $|y|&lt;1.0$ for $p_T(B)>6.0$ GeV/$c$, is $3.6 \pm 0.6 ({\rm stat} \oplus {\rm syst)} \mu$b. The measured differential cross section is substantially larger than typical QCD predictions calculated to next-to-leading order.

2 data tables

Measured differential cross section for B+ production. The first (DSYS) error is the PT dependent systematic error and the second is the full correlated systematic error.

The total integrated B+ meson cross section. The first error is the combined statistical and PT dependent systematic error. The DSYS error is the fully correlated systematic error.


Soft and hard interactions in p anti-p collisions at s**(1/2) = 1800-GeV and 630-GeV

The CDF collaboration Acosta, D. ; Affolder, T. ; Akimoto, H. ; et al.
Phys.Rev.D 65 (2002) 072005, 2002.
Inspire Record 567774 DOI 10.17182/hepdata.68015

We present a study of pp¯ collisions at s=1800 and 630 GeV collected using a minimum bias trigger by the CDF experiment in which the data set is divided into two classes corresponding to “soft” and “hard” interactions. For each subsample, the analysis includes measurements of the multiplicity, transverse momentum (pT) spectrum, and the average pT and event-by-event pT dispersion as a function of multiplicity. A comparison of results shows distinct differences in the behavior of the two samples as a function of the center of mass (c.m.) energy. We find evidence that the properties of the soft sample are invariant as a function of c.m. energy.

4 data tables

Charged multiplicity at $\sqrt{s} = 630~\text{GeV}$, $|\eta| < 1$, $p_T > 0.4~\text{GeV}$.

Charged multiplicity at $\sqrt{s} = 1800~\text{GeV}$, $|\eta| < 1$, $p_T > 0.4~\text{GeV}$.

$\langle p_\perp \rangle$ vs. multiplicity at $\sqrt{s} = 630~\text{GeV}$, $|\eta| < 1$, $p_T > 0.4~\text{GeV}$.

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Search for new heavy particles in the W Z0 final state in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 88 (2002) 071806, 2002.
Inspire Record 560924 DOI 10.17182/hepdata.42895

We present a search for new heavy particles, $X$, which decay via $X \to WZ \to e\nu +jj$ in $p{\bar p}$ collisions at $\sqrt{s}$ = 1.8 TeV. No evidence is found for production of $X$ in 110 pb$^{-1}$ of data collected by the Collider Detector at Fermilab. Limits are set at the 95% C.L. on the mass and the production of new heavy charged vector bosons which decay via $W'\to WZ$ in extended gauge models as a function of the width, $\Gamma (W')$, and mixing factor between the $W'$ and the Standard Model $W$ bosons.

1 data table

CONST(NAME=XI) is the mixing factor between WPRIME and W-boson.


Charged jet evolution and the underlying event in proton - anti-proton collisions at 1.8-TeV

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.D 65 (2002) 092002, 2002.
Inspire Record 564673 DOI 10.17182/hepdata.42044

The growth and development of “charged particle jets” produced in proton-antiproton collisions at 1.8 TeV  are studied over a transverse momentum range from 0.5 GeV/c to 50 GeV/c. A variety of leading (highest transverse momentum) charged jet observables are compared with the QCD Monte Carlo models HERWIG, ISAJET, and PYTHIA. The models describe fairly well the multiplicity distribution of charged particles within the leading charged jet, the size of the leading charged jet, the radial distribution of charged particles and transverse momentum around the leading charged jet direction, and the momentum distribution of charged particles within the leading charged jet. The direction of the leading “charged particle jet” in each event is used to define three regions of η−φ space. The “toward” region contains the leading “charged particle jet,” while the “away” region, on the average, contains the away-side jet. The “transverse” region is perpendicular to the plane of the hard 2-to-2 scattering and is very sensitive to the “underlying event” component of the QCD Monte Carlo models. HERWIG, ISAJET, and PYTHIA with their default parameters do not describe correctly all the properties of the “transverse” region.

7 data tables

Average number of charged particles as a function of the relative azimuthal angle between the individual charged particle and the overall leading jet angle.

Average scalar PT sum of charged particles as a function of the relative azimuthal angle between the individual charged particle for 3 different lower limits of the leading jet PT. and the overall jet angle.

The average number of toward(DPHI < 60 DEG), transverse (DPHI 60 TO 120 DEG) and away (DPHI > 120 DEG) charged particles as a function of the PT of the leading charged jet. The data in this table are from the Min-Bias events.

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Charged particle multiplicity in jets in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 87 (2001) 211804, 2001.
Inspire Record 560273 DOI 10.17182/hepdata.42931

We report on a measurement of the mean charged-particle multiplicity of jets in dijet events with dijet masses in the range 80–630GeV/c2, produced at the Tevatron in pp¯ collisions with s=1.8TeV and recorded by the Collider Detector at Fermilab. The data are fit to perturbative-QCD calculations carried out in the framework of the modified leading log approximation and the hypothesis of local parton-hadron duality. The fit yields values for two parameters in that framework: the ratio of parton multiplicities in gluon and quark jets, $r≡N_{partons}^{g−jet} / N_{partons}^{q−jet} = 1.7 \pm 0.3$, and the ratio of the number of charged hadrons to the number of partons in a jet, $K_{LPHD}^{charged} ≡ N_{hadrons}^{charged} / N_{partons} = 0.57 \pm 0.11$.

1 data table

Measured values of inclusive charged particle multiplicity per jet for jets falling in restricted cones with opening angles 0.17, 0.28 and 0.47 radians. Note that the systematic errors are strongly correlated.


Observation of diffractive J / psi production at the Fermilab Tevatron

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 87 (2001) 241802, 2001.
Inspire Record 560628 DOI 10.17182/hepdata.55764

We report the first observation of diffractive $J/\psi(\to \mu^+\mu^-)$ production in $\bar pp$ collisions at $\sqrt{s}$=1.8 TeV. Diffractive events are identified by their rapidity gap signature. In a sample of events with two muons of transverse momentum $p_T^{\mu}>2$ GeV/$c$ within the pseudorapidity region $|\eta|<$1.0, the ratio of diffractive to total $J/\psi$ production rates is found to be $R_{J/\psi}= [1.45\pm 0.25]%$. The ratio $R_{J/\psi}(x)$ is presented as a function of $x$-Bjorken. By combining it with our previously measured corresponding ratio $R_{jj}(x)$ for diffractive dijet production, we extract a value of $0.59\pm 0.15$ for the gluon fraction of the diffractive structure function of the proton.

3 data tables

Diffractive to total J/psi production ratio.

Ratio of diffractive to total J/psi rate, per unit of the fractional momentum loss of the leading (anti)proton, and as a function of x-Bjorken of the struck parton of the (anti)proton adjacent to the rapidity gap and participating in the J/psi production.

Gluon fraction of the diffractive structure function of the (anti)proton.