Massimo, J.T.
Max results
Sort by Reverse order

Showing 10 of 2586 results

Date

Determination of alpha-s from the scaling violation in the fragmentation functions in e+ e- annihilation

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 311 (1993) 408-424, 1993.
Inspire Record 355937 DOI 10.17182/hepdata.48411

A determination of the hadronic fragmentation functions of the Z 0 boson is presented from a study of the inclusive hadron production with the DELPHI detector at LEP. These fragmentation functions were compared with the ones at lower energies, thus covering data in a large kinematic range: 196 ⩽ Q 2 ⩽ 8312 GeV 2 and x (= P h E beam ) > 0.08 . A large scaling violation was observed, which was used to extract the strong coupling constant in second order QCD: α s ( M Z ) = 0.118 ± 0.005. The corresponding QCD scale for five quark flavours is: Λ (5) MS = 230 ± 60 MeV .

2 data tables
Table 1

No description provided.

Table 2

Extraction of strong coupling constant ALP_S and the LAMQCD)MSBAR values.


Inclusive chi(c) and b quark production in anti-p p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, Michael G. ; Amidei, Dante E. ; et al.
Phys.Rev.Lett. 71 (1993) 2537-2541, 1993.
Inspire Record 357240 DOI 10.17182/hepdata.19721

We report the full reconstruction of χc mesons through the decay chain χc→J/ψ γ, J/ψ→μ+μ−, using data obtained at the Collider Detector at Fermilab in 2.6±0.2 pb−1 of p¯p collisions at √s =1.8 TeV. This exclusive χc sample is used to measure the χc-meson production cross section times branching fractions. We obtain σ×B=3.2±0.4(stat)−1.1+1.2(syst) nb for χc mesons decaying to J/ψ with pT>6.0 GeV/c and pseudorapidity ‖η‖<0.5. From this and the inclusive J/ψ cross section we calculate the inclusive b-quark cross section to be 12.0±4.5 μb for pTb>8.5 GeV/c and ‖yb‖<1.

2 data tables
Table 1

No description provided.

Table 2

This determination of the b-quark cross section uses an earlier CDF measurement of the pbar p --> J/PSI X cross section of 6.88 +- 1.11 nb. See Abe et al. PRL 69, 3704.


Measurement of bottom quark production in 1.8-TeV p anti-p collisions using semileptonic decay muons

The CDF collaboration Abe, F. ; Albrow, Michael G. ; Amidei, Dante E. ; et al.
Phys.Rev.Lett. 71 (1993) 2396-2400, 1993.
Inspire Record 356237 DOI 10.17182/hepdata.19723

We present a measurement of the b-quark cross section in 1.8 TeV p-p¯ collisions recorded with the Collider Detector at Fermilab using muonic b-quark decays. In the central rapidity region (‖yb‖<1.0), the cross section is 295±21±75 nb (59±14±15 nb) for pTb>21 GeV/c (29 GeV/c). Comparisons are made to previous measurements and next-to-leading order QCD calculations.

1 data table
Table 1

No description provided.


Measurement of Drell-Yan electron and muon pair differential cross-sections in anti-p p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, Michael G. ; Amidei, Dante E. ; et al.
Phys.Rev.D 49 (1994) R1-R6, 1994.
Inspire Record 355927 DOI 10.17182/hepdata.42543

We measure the Drell-Yan differential cross section d2σdMdy||y|<1 over the mass range 11

3 data tables
Table 1

Dielectron differential cross section.

Table 2

Dimuon differential cross section.

Table 3

Drell-Yan differential cross section for combined dielectron and dimuon data. Error includes both statistics and systematics.


A Measurement of alpha-s from jet rates at the Z0 resonance

The SLD collaboration Abe, K. ; Abt, I. ; Acton, P.D. ; et al.
Phys.Rev.Lett. 71 (1993) 2528-2532, 1993.
Inspire Record 356912 DOI 10.17182/hepdata.19724

We have determined the strong coupling αs from measurements of jet rates in hadronic decays of Z0 bosons collected by the SLD experiment at SLAC. Using six collinear and infrared safe jet algorithms we compared our data with the predictions of QCD calculated up to second order in perturbation theory, and also with resummed calculations. We find αs(MZ2)=0.118±0.002(stat)±0.003(syst)±0.010(theory), where the dominant uncertainty is from uncalculated higher order contributions.

1 data table
Table 1

The second systematic error comes from the theoretical uncertainties.


Measurement of small angle anti-proton - proton elastic scattering at S**(1/2) = 546-GeV and 1800-GeV

The CDF collaboration Abe, F. ; Albrow, Michael G. ; Amidei, Dante E. ; et al.
Phys.Rev.D 50 (1994) 5518-5534, 1994.
Inspire Record 359411 DOI 10.17182/hepdata.22369

Antiproton-proton elastic scattering was measured at c.m.s. energies √s =546 and 1800 GeV in the range of four-momentum transfer squared 0.025<-t<0.29 GeV2. The data are well described by the exponential form ebt with a slope b=15.28±0.58 (16.98±0.25) GeV−2 at √s =546 (1800) GeV. The elastic scattering cross sections are, respectively, σel=12.87±0.30 and 19.70±0.85 mb.

4 data tables
Table 1

Final results (systematic errors included).

Table 2

Final results (systematic errors included).

Table 3

Statistical errors only. Data supplied by S. Belforte.

More…

Measurement of anti-p p single diffraction dissociation at s**(1/2) = 546-GeV and 1800-GeV

The CDF collaboration Abe, F. ; Albrow, Michael G. ; Amidei, Dante E. ; et al.
Phys.Rev.D 50 (1994) 5535-5549, 1994.
Inspire Record 359393 DOI 10.17182/hepdata.42542

We report a measurement of the diffraction dissociation differential cross section d2σSD/dM2dt for p¯p→p¯X at √s =546 and 1800 GeV, M2/s<0.2 and 0≤-t≤0.4 GeV2. Our results are compared to theoretical predictions and to extrapolations from experimental results at lower energies.

1 data table
Table 1

Single diffraction dissociation cross section.


Measurement of the anti-proton proton total cross-section at s**(1/2) = 546-GeV and 1800-GeV

The CDF collaboration Abe, F. ; Albrow, Michael G. ; Amidei, Dante E. ; et al.
Phys.Rev.D 50 (1994) 5550-5561, 1994.
Inspire Record 359412 DOI 10.17182/hepdata.42528

We report a measurement of the proton-antiproton total cross section σT at c.m.s. energies √s =546 and 1800 GeV. Using the luminosity-independent method, we find σT=61.26±0.93 mb at √s =546 GeV and 80.03±2.24 mb at √s =1800 GeV. In this energy range, the ratio σel/σT increases from 0.210±0.002 to 0.246±0.004.

2 data tables
Table 1

No description provided.

Table 2

Assuming RHO = 0.15.


rivet Analysis
Production of Lambda and Lambda anti-Lambda correlations in the hadronic decays of the Z0

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 318 (1993) 249-262, 1993.
Inspire Record 360638 DOI 10.17182/hepdata.48369

An analysis of the production of the Λ baryon in the hadronic decays of the Z 0 is presented, based on about 993K multihadronic events collected by the DELPHI detector at LEP during 1991 and 1992. The differencial cross section of the Λ and the correlations between Λ and Λ produced in the same event are compared to current models, based both on string fragmentation and on cluster decay. The predictions of the string fragmentation model are found to give satisfactory agreements with the data, clearly better than those of the cluster model.

6 data tables
Table 1

No description provided.

Table 2

Combined LAMBDA and LAMBDABAR multiplicity.

Table 3

Errors contain systematic uncertainties.

More…

Search for diffractive charm production in 800-GeV/c proton - silicon interactions

The Fermilab E653 collaboration Kodama, K. ; Ushida, N. ; Mokhtarani, A. ; et al.
Phys.Lett.B 316 (1993) 188-196, 1993.
Inspire Record 35969 DOI 10.17182/hepdata.28848

A search for charm production in the coherent diffractive dissociation reaction pSi→XSi was carried out for the modes D 0 → K − π + , D 0 → K − π + π + π − , and D + → K − π + π + . No charm signals were observed, and the 90% confidence level upper limit for coherent charm pair production was determined to be 26 μ b per silicon nucleus. The results are interpreted as an upper limit of 0.2% on the amount of intrinsic charm in the proton.

1 data table
Table 1

90 pct CL upper limits.