Measurement of the production and lepton charge asymmetry of $\textit{W}$ bosons in Pb+Pb collisions at $\sqrt{s_{\mathrm{\mathbf{NN}}}}=$ 2.76 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Eur.Phys.J.C 75 (2015) 23, 2015.
Inspire Record 1311623 DOI 10.17182/hepdata.66358

A measurement of $\textit{W}$ boson production in lead-lead collisions at $\sqrt{s_{\mathrm{NN}}}=$2.76 TeV is presented. It is based on the analysis of data collected with the ATLAS detector at the LHC in 2011 corresponding to an integrated luminosity of 0.14 $\mathrm{nb}^{-1}$ and 0.15 $\mathrm{nb}^{-1}$ in the muon and electron decay channels, respectively. The differential production yields and lepton charge asymmetry are each measured as a function of the average number of participating nucleons $< N_{\mathrm{part}} >$ and absolute pseudorapidity of the charged lepton. The results are compared to predictions based on next-to-leading-order QCD calculations. These measurements are, in principle, sensitive to possible nuclear modifications to the parton distribution functions and also provide information on scaling of $\textit{W}$ boson production in multi-nucleon systems.

5 data tables

Ratio of W+ and W- candidates in $W\rightarrow \ell \nu_{\ell}$ as a function of the mean number of participants $N_{part}$.

$W^\pm$ boson production yield per binary collision as a function of the mean number of participants $N_{part}$.

Differential production yield per binary collision for $W^{+}$ bosons as a function of $|\eta_\ell|$.

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Observation of a Centrality-Dependent Dijet Asymmetry in Lead-Lead Collisions at sqrt(S(NN) ) = 2.76 TeV with the ATLAS Detector at the LHC

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Rev.Lett. 105 (2010) 252303, 2010.
Inspire Record 878733 DOI 10.17182/hepdata.63790

Using the ATLAS detector, observations have been made of a centrality-dependent dijet asymmetry in the collisions of lead ions at the Large Hadron Collider. In a sample of lead-lead events with a per-nucleon center of mass energy of 2.76 TeV, selected with a minimum bias trigger, jets are reconstructed in fine-grained, longitudinally-segmented electromagnetic and hadronic calorimeters. The underlying event is measured and subtracted event-by-event, giving estimates of jet transverse energy above the ambient background. The transverse energies of dijets in opposite hemispheres is observed to become systematically more unbalanced with increasing event centrality leading to a large number of events which contain highly asymmetric dijets. This is the first observation of an enhancement of events with such large dijet asymmetries, not observed in proton-proton collisions, and which may point to an interpretation in terms of strong jet energy loss in a hot, dense medium.

4 data tables

Asymmetry in the different centrality regions for 2.76 TeV/Nucleon PB-PB collisions.

Asymmetry in 7 TeV P-P collisions.

DeltaPhi distribution in the different centrality regions for 2.76 TeV/Nucleon PB-PB collisions.

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Study of D+ and D- Feynman's x distributions in pi- nucleus interactions at the SPS

The WA82 collaboration Adamovich, M. ; Alexandrov, Y. ; Antinori, F. ; et al.
Phys.Lett.B 305 (1993) 402-406, 1993.
Inspire Record 354903 DOI 10.17182/hepdata.48370

Experiment WA82 studied charm production by a π − beam of 340 GeV/ c at the CERN Ω′ spectrometer, using a silicon microstrip vertex detector and an impact parameter trigger. Results on the x F distributions of D + and D − mesons are presented and discussed. A clear excess of D − over D + , increasing at high x F , is observed.

2 data tables

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A Determination of electroweak parameters from Z0 ---> mu+ mu- (gamma)

The L3 collaboration Adeva, B. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 247 (1990) 473-480, 1990.
Inspire Record 297172 DOI 10.17182/hepdata.29622

We have measured the partial width and forward-backward charge asymmetry for the reaction e + e - →Z 0 →μ + μ - (γ). We obtain a partial width Γ μμ of 83.3±1.3(stat)±0.9(sys) MeV and the following values for the vector and axial vector couplings: g v =−0.062 −0.015 +0.020 and g A =−0.497 −0.005 +0.005 . From our measurement of the partial width and the mass of the Z 0 boson we determine the effective electroweak mixing angle, sin 2 θ w =0.232±0.005, and the neutral current coupling strength parameter, ϱ =0.998±0.016.

4 data tables

No description provided.

Forward backward charge asymmetry.

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Production and Decay of Charmed Mesons in $e^+ e^-$ Annihilation at $\sqrt{s}$ > 28-{GeV}

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Z.Phys.C 44 (1989) 365, 1989.
Inspire Record 278856 DOI 10.17182/hepdata.15361

We report on a study of inclusive production ofD*± mesons ine+e− annihilation at c.m. energies between 28 and 46.8 GeV using the TASSO detector at the PETRA storage ring. A hardD*± energy spectrum is measured with a maximum nearED*±≃0.6Ebeam. The measured cross section ratio\((\sigma _{D^{* + } }+ \sigma _{D^{* - } } )/\sigma _{\mu \mu }= 1.28 \pm 0.09 \pm 0.18\) indicates thatD* production accounts for a large fraction of the observed charm production. Two complementary methods have been used to determine the forward-backward asymmetry of charm pair production due to electroweak interference. Combining both measurements the product of the axial vector couplings of the electron and the charm quark to the weak neutral current was determined to begAegAc=−(0.276±0.073), in agreement with the standard model prediction of −0.25. Using a sample of reconstructedD*± mesons, the relative strength of the strong interaction coupling of thec quark compared to that of an average of all flavours is measured as αs(c)/αs(all)=0.91±0.38±0.15, consistent with the coupling constant being flavour independent. An update of ourD0 lifetime measurement is presented, based on a considerable increase in statistics, the final result being\(\tau _{D^0= } (4.8 \pm _{0.9 - 0.7}^{1.0 + 0.5} )10^{ - 13} s\).

5 data tables

Cross sections using D0 --> K- PI+ channel.

Cross sections using D0 --> K- PI+ PI- PI+ channel.

No description provided.

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Measurement of $e^+ e^- \to \mu^+ \mu^-$: A Test of Electroweak Theories

The Mark-J collaboration Adeva, B. ; Becker, U. ; Becker-Szendy, R. ; et al.
Phys.Rev.Lett. 55 (1985) 665, 1985.
Inspire Record 214607 DOI 10.17182/hepdata.3237

We use the reaction e+e−→μ+μ−, in the Mark J detector at the DESY high-energy e+e− collider PETRA, to test the standard electroweak theory and find good agreement. We also set limits on the parameters of several extended gauge theories.

6 data tables

CROSS SECTION MEASUREMENT RELATIVE TO PREDICTED QED CROSS SECTION.

FORWARD-BACKWARD ASYMMETRY. THE SYSTEMATIC ERROR IN THE ASYMMETRY IS <0.5 PCT.

ANGULAR DISTRIBUTIONS NOT GIVEN IN PAPER. SUPPLIED BY E.DEFFUR.

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Measurement of $e^+ e^- \to \mu^+ \mu^-$ Charge Asymmetry

Adeva, B. ; Barber, D.P. ; Becker, U. ; et al.
Phys.Rev.Lett. 48 (1982) 1701, 1982.
Inspire Record 177308 DOI 10.17182/hepdata.3116

The measurement of the nonelectromagnetic forward-backward charge asymmetry in the reaction e+e−→μ+μ− at s∼34.6 GeV and in the angular region 0<|cosθ|<0.8 is reported. With a systematic error less than 1%, we observe an asymmetry of (-8.1±2.1)%. This is in agreement with the standard electroweak theory prediction of (-7.6±0.6)%. The weak-current coupling constants are also reported.

4 data tables

SEE PRL 55, 665 FOR DISTRIBUTIONS AT 34.6 GEV AND ABOVE.

SEE PRL 55, 665 FOR CROSS SECTION VALUES AND FORWARD BACKWARD ASYMMETRY.

No description provided.

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Production Cross-section and Electroweak Asymmetry of $D^*$ and $D$ Mesons Produced in $e^+ e^-$ Annihilations at 29-{GeV}

Baringer, Philip S. ; Bylsma, B.G. ; DeBonte, R. ; et al.
Phys.Lett.B 206 (1988) 551-556, 1988.
Inspire Record 23360 DOI 10.17182/hepdata.6192

The production of D * and D mesons has been studied in e + e − annihilations at √s = 29GeV. The data, corresponding to an integrated luminosity of 300 pb −1 , were obtained using the HRS detector at PEP. The cross section is measured to be R (D 0 + D + ) = 2.40±0.35 and we determine the electroweak asymmetry to be −9.9 ± 2.7%, which corresponds to an axial vector coupling constant product g e g c = 0.26 ± 0.07.

11 data tables

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ANGULAR AND ENERGY CHARACTERISTICS OF SECONDARY CHARGED PARTICLES FROM ANTI-PROTON PROTON INTERACTIONS AT 22.4-GEV/C MOMENTUM

Boos, E.G. ; Ermilova, D.I. ; Samoilov, V.V. ; et al.
Alma Ata Inst. High Energy Phys. Acad. Sci. - 85-04 (rec.Jul.86) 19 p, 1984.
Inspire Record 210833 DOI 10.17182/hepdata.13427

None

58 data tables

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CHARGE PROPERTIES OF ANNIHILATION EXCLUSIVE REACTIONS IN anti-p p INTERACTIONS AT 32-GeV/c

Bogolyubsky, M.Yu. ; Kiryunin, A.E. ; Kotova, A.I. ; et al.
Yad.Fiz. 45 (1987) 1667, 1987.
Inspire Record 234595 DOI 10.17182/hepdata.10409

None

24 data tables

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