Single particles and jets in deeply inelastic scattering at low x are measured with the H1 detector in the region away from the current jet and towards the proton remnant, known as the forward region. Hadronic final state measurements in this region are expected to be particularly sensitive to QCD evolution effects. Jet cross-sections are presented as a function of Bjorken-x for forward jets produced with a polar angle to the proton direction, theta, in the range 7 < theta < 20 degrees. Azimuthal correlations are studied between the forward jet and the scattered lepton. Charged and neutral single particle production in the forward region are measured as a function of Bjorken-x, in the range 5 < theta < 25 degrees, for particle transverse momenta larger than 1 GeV. QCD based Monte Carlo predictions and analytical calculations based on BFKL, CCFM and DGLAP evolution are compared to the data. Predictions based on the DGLAP approach fail to describe the data, except for those which allow for a resolved photon contribution.
Forward Jet cross section. Axis error includes +- 7/7 contribution (Dependence of the model used to correct the data).
Forward Di-jet cross section. Axis error includes +- 7/7 contribution (Dependence of the model used to correct the data).
Data from Figure 3a on charged particle production
The STAR collaboration at RHIC reports measurements of the inclusive yield of non-photonic electrons, which arise dominantly from semi-leptonic decays of heavy flavor mesons, over a broad range of transverse momenta ($1.2 < \pt < 10$ \gevc) in \pp, \dAu, and \AuAu collisions at \sqrtsNN = 200 GeV. The non-photonic electron yield exhibits unexpectedly large suppression in central \AuAu collisions at high \pt, suggesting substantial heavy quark energy loss at RHIC. The centrality and \pt dependences of the suppression provide constraints on theoretical models of suppression.
Non photonic electron yield in P+P collisions versus PT To obtain a differential cross-section in mb/(GeV2), multiply listed data by 30 Note that, in addition to the statistical and systematical errors, there is a normalization error on the value, given in the second column.
Non photonic electron yield in P+P collisions versus $p_{T}$. To obtain a differential cross-section in mb/(GeV$^2$), multiply listed data by 30.
Non photonic electron yield in minimum bias D+AU collisions versus PT To obtain a differential cross-section in mb/(GeV2), multiply listed data by 30 Note that, in addition to the statistical and systematical errors, there is a normalization error on the value, given in the second column.
Measurements of the differential cross section for the Drell-Yan process, based on proton-proton collision data at a centre-of-mass energy of 13 TeV, collected by the CMS experiment, are presented. The data correspond to an integrated luminosity of 2.8 (2.3) fb$^{-1}$ in the dimuon (dielectron) channel. The total and fiducial cross section measurements are presented as a function of dilepton invariant mass in the range 15 to 3000 GeV, and compared with the perturbative predictions of the standard model. The measured differential cross sections are in good agreement with the theoretical calculations.
Summary of the systematic uncertainties (%) for the $ d\sigma / d{m}$ (pb/GeV) measurement in the dimuon channel. The column labelled "Total" corresponds to the quadratic sum of all the experimental sources, except for that Acceptance+PDF.
Summary of the systematic uncertainties (%) for the $ d\sigma / d{m}$ (pb/GeV) measurement in the dielectron channel. The column labelled "Total" corresponds to the quadratic sum of all the experimental sources, except for that Acceptance+PDF.
Summary of the measured values of $ d\sigma / d{m}$ (pb/GeV) in the dimuon channel with the statistical ($\delta_{\text{stat}}$), experimental ($\delta_{\text{exp}}$) and theoretical ($\delta_{\text{theo}}$) uncertainties, respectively. Here, $\delta_{\text{tot}}$ is the quadratic sum of the three components.
A measurement of charged-particle distributions sensitive to the properties of the underlying event is presented for an inclusive sample of events containing a Z-boson , decaying to an electron or muon pair. The measurement is based on data collected using the ATLAS detector at the LHC in proton-proton collisions at a centre-of-mass energy of 7 TeV with an integrated luminosity of $4.6$ fb$^{-1}$. Distributions of the charged particle multiplicity and of the charged particle transverse momentum are measured in regions of azimuthal angle defined with respect to the Z-boson direction. The measured distributions are compared to similar distributions measured in jet events, and to the predictions of various Monte Carlo generators implementing different underlying event models.
Towards scalar pT sum density vs Z-boson pT, Born leptons : Statistical and systematic errors are added in quadrature.
Transverse scalar pT sum density vs Z-boson pT, Born leptons : Statistical and systematic errors are added in quadrature.
Away scalar pT sum density vs Z-boson pT, Born leptons : Statistical and systematic errors are added in quadrature.
We present a measurement of the electron charge asymmetry in $p\bar{p}\rightarrow W+X \rightarrow e\nu +X$ events at a center-of-mass energy of 1.96 TeV, using data corresponding to 9.7~fb$^{-1}$ of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. The asymmetry is measured as a function of the electron pseudorapidity and is presented in five kinematic bins based on the electron transverse energy and the missing transverse energy in the event. The measured asymmetry is compared with next-to-leading-order predictions in perturbative quantum chromodynamics and provides accurate information for the determination of parton distribution functions of the proton. This is the most precise lepton charge asymmetry measurement to date.
CP-folded electron charge asymmetry for data with $E_T^{e} > 25$ GeV multiplied by 100. $\langle|\eta^e|\rangle$ is the cross section weighted average of electron pseudorapidity in each bin from RESBOS with PHOTOS.
CP-folded electron charge asymmetry for data with $25 < E_T^{e} < 35$ GeV multiplied by 100. $\langle|\eta^e|\rangle$ is the cross section weighted average of electron pseudorapidity in each bin from RESBOS with PHOTOS.
CP-folded electron charge asymmetry for data with $E_T^{e} > 35$ GeV multiplied by 100. $\langle|\eta^e|\rangle$ is the cross section weighted average of electron pseudorapidity in each bin from RESBOS with PHOTOS.
The ALICE Collaboration has measured inclusive J/psi production in pp collisions at a center of mass energy sqrt(s)=2.76 TeV at the LHC. The results presented in this Letter refer to the rapidity ranges |y|<0.9 and 2.5<y<4 and have been obtained by measuring the electron and muon pair decay channels, respectively. The integrated luminosities for the two channels are L^e_int=1.1 nb^-1 and L^mu_int=19.9 nb^-1, and the corresponding signal statistics are N_J/psi^e+e-=59 +/- 14 and N_J/psi^mu+mu-=1364 +/- 53. We present dsigma_J/psi/dy for the two rapidity regions under study and, for the forward-y range, d^2sigma_J/psi/dydp_t in the transverse momentum domain 0<p_t<8 GeV/c. The results are compared with previously published results at sqrt(s)=7 TeV and with theoretical calculations.
Double differential J/$\psi$ production cross section at $\sqrt{s}=2.76$ TeV. The first uncertainty is statistical, the second one is $p_{\rm T}$-coorelated, the third one is uncorrelated. Polarization-related uncertainties are not included.
The $\sqrt{s}$-dependence of $\langle p_{\rm T}\rangle$ for inclusive J/$\psi$ production (forward rapidity).
the $\sqrt{s}$-dependence of $\langle p_{\rm T}\rangle$ for inclusive J/$\psi$ production (forward rapidity).
A precise measurement of the anomalous g value, a_mu=(g-2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron. The result a_mu^+=11 659 202(14)(6) X 10^{-10} (1.3 ppm) is in good agreement with previous measurements and has an error one third that of the combined previous data. The current theoretical value from the standard model is a_mu(SM)=11 659 159.6(6.7) X 10^{-10} (0.57 ppm) and a_mu(exp)-a_mu(SM)=43(16) X 10^{-10} in which a_mu(exp) is the world average experimental value.
The anomalous G value is related to the gyromagnetic ratio by MOM(N=A_MU) =(G-2)/2.
A new measurement of the positive muon's anomalous magnetic moment has been made at the Brookhaven Alternating Gradient Synchrotron using the direct injection of polarized muons into the superferric storage ring. The angular frequency difference omega_{a} between the angular spin precession frequency omega_{s} and the angular orbital frequency omega_{c} is measured as well as the free proton NMR frequency omega_{p}. These determine R = omega_{a} / omega_{p} = 3.707~201(19) times 10^{-3}. With mu_{mu} / mu_{p} = 3.183~345~39(10) this gives a_{mu^+} = 11~659~191(59) times 10^{-10} (pm 5 ppm), in good agreement with the previous CERN and BNL measurements for mu^+ and mu^-, and with the standard model prediction.
The anomalous g value is related to the gyromagnetic ratio by MOM(NAME=ANOMALOUS MAGNETIC) = (G-2)/2. The beam momentum spread is about 1 PCT.
The muon anomalous magnetic moment has been measured in a new experiment at Brookhaven. Polarized muons were stored in a superferric ring, and the angular frequency difference, ωa, between the spin precession and orbital frequencies was determined by measuring the time distribution of high-energy decay positrons. The ratio R of ωa to the Larmor precession frequency of free protons, ωp, in the storage-ring magnetic field was measured. We find R=3.707220(48)×10−3. With μμ/μp=3.18334547(47) this gives aμ+=1165925(15)×10−9 ( ±13ppm), in good agreement with the previous CERN measurements for μ+ and μ− and of approximately the same precision.
The anomalous g value is related to the gyromagnetic ratio by MOM(NAME=ANOMALOUS MAGNETIC) = (G-2)/2. The beam momentum spread is about 1 PCT.
First measurements of the W -> lnu and Z/gamma* -> ll (l = e, mu) production cross sections in proton-proton collisions at sqrt(s) = 7 TeV are presented using data recorded by the ATLAS experiment at the LHC. The results are based on 2250 W -> lnu and 179 Z/gamma* -> ll candidate events selected from a data set corresponding to an integrated luminosity of approximately 320 nb-1. The measured total W and Z/gamma*-boson production cross sections times the respective leptonic branching ratios for the combined electron and muon channels are $\stotW$ * BR(W -> lnu) = 9.96 +- 0.23(stat) +- 0.50(syst) +- 1.10(lumi) nb and $\stotZg$ * BR(Z/gamma* -> ll) = 0.82 +- 0.06(stat) +- 0.05(syst) +- 0.09(lumi) nb (within the invariant mass window 66 < m_ll < 116 GeV). The W/Z cross-section ratio is measured to be 11.7 +- 0.9(stat) +- 0.4(syst). In addition, measurements of the W+ and W- production cross sections and of the lepton charge asymmetry are reported. Theoretical predictions based on NNLO QCD calculations are found to agree with the measurements.
Measured fiducial cross section times leptonic branching ratio for W+ production in the W+ -> e+ nu final state.
Measured fiducial cross section times leptonic branching ratio for W- production in the W- -> e- nubar final state.
Measured fiducial cross section times leptonic branching ratio for W+/- production in the combined W+ -> e+ nu and W- -> e- nubar final state.
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