Separated cross-sections in pi0 electroproduction at threshold at Q**2 = 0.05-GeV**2/c**2

The A1 collaboration Weis, M. ; Bartsch, P. ; Baumann, D. ; et al.
Eur.Phys.J.A 38 (2008) 27-33, 2008.
Inspire Record 751930 DOI 10.17182/hepdata.51606

The differential cross sections \sigma_0=\sigma_T+\epsilon \sigma_L, \sigma_{LT}, and \sigma_{TT} of \pi^0 electroproduction from the proton were measured from threshold up to an additional center of mass energy of 40 MeV, at a value of the photon four-momentum transfer of Q^2= 0.05 GeV^2/c^2 and a center of mass angle of \theta=90^\circ. By an additional out-of-plane measurement with polarized electrons \sigma_{LT'} was determined. This showed for the first time the cusp effect above the \pi^+ threshold in the imaginary part of the s-wave. The predictions of Heavy Baryon Chiral Perturbation Theory are in disagreement with these data. On the other hand, the data are somewhat better predicted by the MAID phenomenological model and are in good agreement with the dynamical model DMT.

1 data table match query

Beam helicity asymmetry.


Inclusive and differential measurements of the $t\overline{t}$ charge asymmetry in pp collisions at $\sqrt{s} =$ 8 TeV

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
Phys.Lett.B 757 (2016) 154-179, 2016.
Inspire Record 1382590 DOI 10.17182/hepdata.68759

The t t-bar charge asymmetry is measured in proton-proton collisions at a centre-of-mass energy of 8 TeV. The data, collected with the CMS experiment at the LHC, correspond to an integrated luminosity of 19.7 inverse femtobarns. Selected events contain an electron or a muon and four or more jets, where at least one jet is identified as originating from b-quark hadronization. The inclusive charge asymmetry is found to be 0.0010 +/- 0.0068 (stat) +/- 0.0037 (syst). In addition, differential charge asymmetries as a function of rapidity, transverse momentum, and invariant mass of the t t-bar system are studied. For the first time at the LHC, the measurements are also performed in a reduced fiducial phase space of top quark pair production, with an integrated result of -0.0035 +/- 0.0072 (stat) +/- 0.0031 (syst). All measurements are consistent within two standard deviations with zero asymmetry as well as with the predictions of the standard model.

16 data tables match query

Corrected asymmetry as a function of $|y_\mathrm{t\bar{t}}|$ in the fiducial phase space. The value 9999 is used as a placeholder for infinity. The correlation matrix for these values can be found in a separate table.

Correlation matrix for the asymmetries as a function of $|y_\mathrm{t\bar{t}}|$ in the fiducial phase space. Both statistical and systematic effects are considered.

Corrected asymmetry as a function of $p_\text{T}^\mathrm{t\bar{t}}$ in the fiducial phase space. The value 9999 is used as a placeholder for infinity. The correlation matrix for these values can be found in a separate table.

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Measurement of the charge asymmetry in top quark pair production in pp collisions at $\sqrt{s} =$ 8 TeV using a template method

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
Phys.Rev.D 93 (2016) 034014, 2016.
Inspire Record 1388178 DOI 10.17182/hepdata.69208

The charge asymmetry in the production of top quark and antiquark pairs is measured in proton-proton collisions at a center-of-mass energy of 8 TeV. The data, corresponding to an integrated luminosity of 19.6 inverse femtobarns, were collected by the CMS experiment at the LHC. Events with a single isolated electron or muon, and four or more jets, at least one of which is likely to have originated from hadronization of a bottom quark, are selected. A template technique is used to measure the asymmetry in the distribution of differences in the top quark and antiquark absolute rapidities. The measured asymmetry is A[c,y] = [0.33 +/- 0.26 (stat) +/- 0.33 (syst)]%, which is the most precise result to date. The results are compared to calculations based on the standard model and on several beyond-the-standard-model scenarios.

1 data table match query

The measured $t\bar{t}$ production asymmetry $A_c^y$.


Forward–backward asymmetry of Drell–Yan lepton pairs in pp collisions at $\sqrt{s} = 8$ $\,\mathrm{TeV}$

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
Eur.Phys.J.C 76 (2016) 325, 2016.
Inspire Record 1415949 DOI 10.17182/hepdata.73121

A measurement of the forward-backward asymmetry A[FB] of oppositely charged lepton pairs (mu mu and e e) produced via Z/gamma* boson exchange in pp collisions at sqrt(s) = 8 TeV is presented. The data sample corresponds to an integrated luminosity of 19.7 inverse femtobarns collected with the CMS detector at the LHC. The measurement of A[FB] is performed for dilepton masses between 40 GeV and 2 TeV and for dilepton rapidity up to 5. The A[FB] measurements as a function of dilepton mass and rapidity are compared with the standard model predictions.

40 data tables match query

Unfolded combined measurements of AFB in each M-|y| bin (mu+mu- and e+e- combined).

Unfolded measurement of AFB for the forward rapidity region (e+e-).

Unfolded measurements of AFB in each M-|y| bin (mu+mu-).

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Measurement of the forward-backward asymmetry in $Z/\gamma^{\ast} \rightarrow \mu^{+}\mu^{-}$ decays and determination of the effective weak mixing angle

The LHCb collaboration Aaij, Roel ; Adeva, Bernardo ; Adinolfi, Marco ; et al.
JHEP 11 (2015) 190, 2015.
Inspire Record 1394859 DOI 10.17182/hepdata.76490

The forward-backward charge asymmetry for the process $q\bar{q} \rightarrow Z/\gamma^{\ast} \rightarrow \mu^{+}\mu^{-}$ is measured as a function of the invariant mass of the dimuon system. Measurements are performed using proton proton collision data collected with the LHCb detector at $\sqrt{s} = 7$ and 8\tev, corresponding to integrated luminosities of $1$fb$^{-1}$ and $2$fb$^{-1}$ respectively. Within the Standard Model the results constrain the effective electroweak mixing angle to be $$sin^{2}\theta_{W}^{eff} = 0.23142 \pm 0.00073 \pm 0.00052 \pm 0.00056 $$ where the first uncertainty is statistical, the second systematic and the third theoretical. This result is in agreement with the current world average, and is one of the most precise determinations at hadron colliders to date.

2 data tables match query

Values for $A_{\rm{FB}}$ with the statistical and positive and negative systematic uncertainties for $\sqrt{s}$ = 7 TeV data. The theoretical uncertainties presented in this table, corresponding to the PDF, scale and FSR uncertainties described in Sec. 5, affect only the predictions of $A_{\rm{FB}}$ and the sin$^2\theta^{\rm{eff}}_{\rm W}$ determination, and do not apply to the uncertainties on the measured $A_{\rm{FB}}$.

Values for $A_{\rm{FB}}$ with the statistical and positive and negative systematic uncertainties for $\sqrt{s}$ = 8 TeV data. The theoretical uncertainties presented in this table, corresponding to the PDF, scale and FSR uncertainties described in Sec. 5, affect only the predictions of $A_{\rm{FB}}$ and the sin$^2\theta^{\rm{eff}}_{\rm W}$ determination, and do not apply to the uncertainties on the measured $A_{\rm{FB}}$.


Forward-Backward Asymmetry of Drell-Yan Lepton Pairs in $pp$ Collisions at $\sqrt{s} = 7$ TeV

The CMS collaboration Chatrchyan, Serguei ; Khachatryan, Vardan ; Sirunyan, Albert M ; et al.
Phys.Lett.B 718 (2013) 752-772, 2013.
Inspire Record 1122847 DOI 10.17182/hepdata.65322

A measurement of the forward-backward asymmetry (A[FB]) of Drell-Yan lepton pairs in pp collisions at sqrt(s) = 7 TeV is presented. The data sample, collected with the CMS detector, corresponds to an integrated luminosity of 5 inverse femtobarns. The asymmetry is measured as a function of dilepton mass and rapidity in the dielectron and dimuon channels. Combined results from the two channels are also presented. The A[FB] measurement in the dimuon channel and the combination of the two channels are the first such results obtained at a hadron collider. The measured asymmetries are consistent with the standard model predictions.

15 data tables match query

The unfolded mu+mu- measurement of AFB at the Born level in four rapidity bins. The errors on data are statistical only.

The unfolded e+e- measurement of AFB at the Born level in four rapidity bins. The errors on data are statistical only.

Unfolded combined measurements of AFB in each M-|y| bin (mu+mu- and e+e- combined).

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Measurement of the Electron Charge Asymmetry in Inclusive $W$ Production in $pp$ Collisions at $\sqrt{s}=7$ TeV

The CMS collaboration Chatrchyan, Serguei ; Khachatryan, Vardan ; Sirunyan, Albert M ; et al.
Phys.Rev.Lett. 109 (2012) 111806, 2012.
Inspire Record 1118047 DOI 10.17182/hepdata.66333

A measurement of the electron charge asymmetry in inclusive pp to W + X to e nu + X production at sqrt(s) = 7 TeV is presented based on data recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 840 inverse picobarns. The electron charge asymmetry reflects the unequal production of positive and negative W bosons in pp collisions. The electron charge asymmetry is measured in bins of absolute value of electron pseudorapidity in the range of abs(eta) < 2.4. The asymmetry rises from about 0.1 to 0.2 as a function of the pseudorapidity and is measured with a relative precision better than 7%. This measurement provides new stringent constraints for parton distribution functions.

2 data tables match query

Summary of the measured charge asymmetry results. The first uncertainty is statistical and the second is systematic. The theoretical predictions are obtained using MCFM interfaced with four different PDF models. The PDF uncertainties are estimated using the PDF reweighting technique. All values are in units of $10^{-3}$.

Covariance matrix for the systematic uncertainties on the asymmetry. All values are given in units of $10^{-6}$.


Measurement of the Muon Charge Asymmetry in Inclusive $pp \to W+X$ Production at $\sqrt s =$ 7 TeV and an Improved Determination of Light Parton Distribution Functions

The CMS collaboration Chatrchyan, Serguei ; Khachatryan, Vardan ; Sirunyan, Albert M ; et al.
Phys.Rev.D 90 (2014) 032004, 2014.
Inspire Record 1273570 DOI 10.17182/hepdata.65456

Measurements of the muon charge asymmetry in inclusive pp to WX production at sqrt(s) = 7 TeV are presented. The data sample corresponds to an integrated luminosity of 4.7 inverse femtobarns recorded with the CMS detector at the LHC. With a sample of more than twenty million W to mu nu events, the statistical precision is greatly improved in comparison to previous measurements. These new results provide additional constraints on the parton distribution functions of the proton in the range of the Bjorken scaling variable x from 10E-3 to 10E-1. These measurements and the recent CMS measurement of associated W + charm production are used together with the cross sections for inclusive deep inelastic ep scattering at HERA in a next-to-leading-order QCD analysis. The determination of the valence quark distributions is improved, and the strange-quark distribution is probed directly through the leading-order process g + s to W + c in proton-proton collisions at the LHC.

4 data tables match query

Summary of the final results for muon charge asymmetry $\mathcal{A}$ with the muon $p_{T}>25$ GeV. The first uncertainty is statistical and the second is systematic. The theoretical predictions are obtained using the FEWZ 3.1 MC tool interfaced with the NLO CT10, NNPDF2.3, HERAPDF1.5, and MSTW2008CPdeut PDF sets. The PDF uncertainty is at 68% C.L. The values are expressed as percentages.

Summary of the final results for muon charge asymmetry $\mathcal{A}$ with the muon $p_{T}>35$ GeV. The first uncertainty is statistical and the second is systematic. The theoretical predictions are obtained using the FEWZ 3.1 MC tool interfaced with the NLO CT10, NNPDF2.3, HERAPDF1.5, and MSTW2008CPdeut PDF sets. The PDF uncertainty is at 68% C.L. The values are expressed as percentages.

Covariance matrix (statistical and systematic uncertainties combined) with the muon $p_{T}>25$ GeV. The units are in $10^{-4}$.

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Measurements of the $t\bar{t}$ charge asymmetry using the dilepton decay channel in pp collisions at $\sqrt{s} =$ 7 TeV

The CMS collaboration Chatrchyan, Serguei ; Khachatryan, Vardan ; Sirunyan, Albert M ; et al.
JHEP 04 (2014) 191, 2014.
Inspire Record 1281538 DOI 10.17182/hepdata.64729

The t t-bar charge asymmetry in proton-proton collisions at sqrt(s) = 7 TeV is measured using the dilepton decay channel (ee, e mu, or mu mu). The data correspond to a total integrated luminosity of 5.0 inverse femtobarns, collected by the CMS experiment at the LHC. The t t-bar and lepton charge asymmetries, defined as the differences in absolute values of the rapidities between the reconstructed top quarks and antiquarks and of the pseudorapidities between the positive and negative leptons, respectively, are measured to be Ac = -0.010 +/- 0.017 (stat.) +/- 0.008 (syst.) and Ac[lep] = 0.009 +/- 0.010 (stat.) +/- 0.006 (syst). The lepton charge asymmetry is also measured as a function of the invariant mass, rapidity, and transverse momentum of the t t-bar system. All measurements are consistent with the expectations of the standard model.

4 data tables match query

The unfolded ASYMC and ASYMC(LEPTON) measurements.

Measurements of the unfolded ASYMC(LEPTON) values in bins of M(TOP TOPBAR).

Measurements of the unfolded ASYMC(LEPTON) values in bins of ABS(YRAP(TOP TOPBAR)).

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Measurement of the forward backward asymmetry of c and b quarks at the Z pole using reconstructed D mesons

The DELPHI collaboration Abreu, P. ; Adye, T. ; Adzic, P. ; et al.
Eur.Phys.J.C 10 (1999) 219-237, 1999.
Inspire Record 495464 DOI 10.17182/hepdata.49295

A measurement of the forward--backward asymmetry of $e^{+}e^{-} \to c\bar{c}$ and $e^{+}e^{-} \to b\bar{b}$ on the $Z$ resonance is performed using about 3.5 million hadronic $Z$ decays collected by the DELPHI detector at LEP in the years 1992 to 1995. The heavy quark is tagged by the exclusive reconstruction of several $D$ meson decay modes. The forward--backward asymmetries for $c$ and $b$ quarks at the $Z$ resonance are determined to be: \[ \renewcommand{\arraystretch}{1.6} \begin{array}{rcr@{}l} \Afbc(\sqrt{s} = 91.235 {\rm GeV}) &=& &0.0659 \pm 0.0094 (stat) \pm 0.0035 (syst) \Afbb (\sqrt{s} = 91.235 {\rm GeV}) &=& &0.0762 \pm 0.0194 (stat) \pm 0.0085 (syst) \Afbc(\sqrt{s} = 89.434 {\rm GeV}) &=&-&0.0496 \pm 0.0368 (stat) \pm 0.0053 (syst) \Afbb(\sqrt{s} = 89.434 {\rm GeV}) &=& &0.0567 \pm 0.0756 (stat) \pm 0.0117 (syst) \Afbc(\sqrt{s} = 92.990 {\rm GeV}) &=& &0.1180 \pm 0.0318 (stat) \pm 0.0062 (syst) \Afbb(\sqrt{s} = 92.990 {\rm GeV}) &=& &0.0882 \pm 0.0633 (stat) \pm 0.0122 (syst) \end{array} \] The combination of these results leads to an effective electroweak mixing angle of: SINEFF = 0.2332 \pm 0.0016

1 data table match query

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