A study of the production of strange octet and decuplet baryons in hadronic decays of the Z recorded by the DELPHI detector at LEP is presented. This includes the first measurement of the∑± average multiplicity. The total and differential cross sections, the event topology and the baryon-antibaryon correlations are compared with current hadronization models.
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The production of Jψ mesons in Z0 decays is studied using 3.6 million hadronic events recorded by the OPAL detector at LEP. The inclusive Z0 to Jψ and b-quark to Jψ branching ratios are measured from the total yield of Jψ mesons, identified from their decays into lepton pairs. The Jψ momentum distribution is used to study the fragmentation of b-quarks. The production rate of ψ′ mesons, identified from their decays into a Jψ and a π+π− pair, is measured as well. The following results are obtained: ${Br(Z^{0}⌝ghtarrow {⤪ J}/ i X)=(3.9pm 0.2pm 0.3)cdot 10^{-3} {⤪ and} ↦op Br(Z^0⌝ghtarrow i ^⌕ime X)=(1.6pm 0.3pm 0.2)cdot 10^{-3}, }$ where the first error is statistical and the second systematic. Finally the Jψ sample is used to reconstruct exclusive b-hadron decays and calculate the corresponding b-hadron branching ratios and masses.
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We report on a measurement of the ratio of the differential cross sections for W and Z boson production as a function of transverse momentum in proton-antiproton collisions at sqrt(s) = 1.8 TeV. This measurement uses data recorded by the D0 detector at the Fermilab Tevatron in 1994-1995. It represents the first investigation of a proposal that ratios between W and Z observables can be calculated reliably using perturbative QCD, even when the individual observables are not. Using the ratio of differential cross sections reduces both experimental and theoretical uncertainties, and can therefore provide smaller overall uncertainties in the measured mass and width of the W boson than current methods used at hadron colliders.
The measured W and Z0 cross sections used to compute the ratio.
The measured ratios of W+-/Z0 cross sections, corrected for the branching ratios BR(W-->e-nue)=0.1073+-0.0025 and BR(Z0-->E+E-)=0.033632+-0.000059 (PDG 2000). The error given is the total error, but note that the 4.3pct error in the luminosity cancels completely in the ratio.
A search for long-lived particles decaying into hadrons is presented. The analysis uses 139 fb$^{-1}$ of $pp$ collision data collected at $\sqrt{s} = 13$ TeV by the ATLAS detector at the LHC using events that contain multiple energetic jets and a displaced vertex. The search employs dedicated reconstruction techniques that significantly increase the sensitivity to long-lived particles decaying in the ATLAS inner detector. Background estimates for Standard Model processes and instrumental effects are extracted from data. The observed event yields are compatible with those expected from background processes. The results are used to set limits at 95% confidence level on model-independent cross sections for processes beyond the Standard Model, and on scenarios with pair-production of supersymmetric particles with long-lived electroweakinos that decay via a small $R$-parity-violating coupling. The pair-production of electroweakinos with masses below 1.5 TeV is excluded for mean proper lifetimes in the range from 0.03 ns to 1 ns. When produced in the decay of $m(\tilde{g})=2.4$ TeV gluinos, electroweakinos with $m(\tilde\chi^0_1)=1.5$ TeV are excluded with lifetimes in the range of 0.02 ns to 4 ns.
<b>Tables of Yields:</b> <a href="?table=validation_regions_yields_highpt_SR">Validation Regions Summary Yields, High-pT jet selections</a> <a href="?table=validation_regions_yields_trackless_SR">Validiation Regions Summary Yields, Trackless jet selections</a> <a href="?table=yields_highpt_SR_observed">Signal region (and sidebands) observed yields, High-pT jet selections</a> <a href="?table=yields_highpt_SR_expected">Signal region (and sidebands) expected yields, High-pT jet selections</a> <a href="?table=yields_trackless_SR_observed">Signal region (and sidebands) observed yields, Trackless jet selections</a> <a href="?table=yields_trackless_SR_expected">Signal region (and sidebands) expected yields, Trackless jet selections</a> <b>Exclusion Contours:</b> <a href="?table=excl_ewk_exp_nominal">EWK RPV signal; expected, nominal</a> <a href="?table=excl_ewk_exp_up">EWK RPV signal; expected, $+1\sigma$</a> <a href="?table=excl_ewk_exp_down">EWK RPV signal; expected, $-1\sigma$</a> <a href="?table=excl_ewk_obs_nominal">EWK RPV signal; observed, nominal</a> <a href="?table=excl_ewk_obs_up">EWK RPV signal; observed, $+1\sigma$</a> <a href="?table=excl_ewk_obs_down">EWK RPV signal; observed, $-1\sigma$</a> <a href="?table=excl_strong_mgluino_2400_GeV_exp_nominal">Strong RPV signal, m($\tilde{g}$)=2.4 TeV; expected, nominal</a> <a href="?table=excl_strong_mgluino_2400_GeV_exp_up">Strong RPV signal, m($\tilde{g}$)=2.4 TeV; expected, $+1\sigma$</a> <a href="?table=excl_strong_mgluino_2400_GeV_exp_down">Strong RPV signal, m($\tilde{g}$)=2.4 TeV; expected, $-1\sigma$</a> <a href="?table=excl_strong_mgluino_2400_GeV_obs_nominal">Strong RPV signal, m($\tilde{g}$)=2.4 TeV; observed, nominal</a> <a href="?table=excl_strong_mgluino_2400_GeV_obs_up">Strong RPV signal, m($\tilde{g}$)=2.4 TeV; observed, $+1\sigma$</a> <a href="?table=excl_strong_mgluino_2400_GeV_obs_down">Strong RPV signal, m($\tilde{g}$)=2.4 TeV; observed, $-1\sigma$</a> <a href="?table=excl_xsec_ewk">EWK RPV signal; cross-section limits for fixed lifetime values.</a> <a href="?table=excl_xsec_strong_mgluino_2400">Strong RPV signal, m($\tilde{g}$)=2.4 TeV; cross-section limits for fixed lifetime values.</a> <a href="?table=excl_strong_mgluino_2000_GeV_exp_nominal">Strong RPV signal, m($\tilde{g}$)=2.0 TeV; expected, nominal</a> <a href="?table=excl_strong_mgluino_2000_GeV_exp_up">Strong RPV signal, m($\tilde{g}$)=2.0 TeV; expected, $+1\sigma$</a> <a href="?table=excl_strong_mgluino_2000_GeV_exp_down">Strong RPV signal, m($\tilde{g}$)=2.0 TeV; expected, $-1\sigma$</a> <a href="?table=excl_strong_mgluino_2000_GeV_obs_nominal">Strong RPV signal, m($\tilde{g}$)=2.0 TeV; observed, nominal</a> <a href="?table=excl_strong_mgluino_2000_GeV_obs_up">Strong RPV signal, m($\tilde{g}$)=2.0 TeV; observed, $+1\sigma$</a> <a href="?table=excl_strong_mgluino_2000_GeV_obs_down">Strong RPV signal, m($\tilde{g}$)=2.0 TeV; observed, $-1\sigma$</a> <a href="?table=excl_strong_mgluino_2200_GeV_exp_nominal">Strong RPV signal, m($\tilde{g}$)=2.2 TeV; expected, nominal</a> <a href="?table=excl_strong_mgluino_2200_GeV_exp_up">Strong RPV signal, m($\tilde{g}$)=2.2 TeV; expected, $+1\sigma$</a> <a href="?table=excl_strong_mgluino_2200_GeV_exp_down">Strong RPV signal, m($\tilde{g}$)=2.2 TeV; expected, $-1\sigma$</a> <a href="?table=excl_strong_mgluino_2200_GeV_obs_nominal">Strong RPV signal, m($\tilde{g}$)=2.2 TeV; observed, nominal</a> <a href="?table=excl_strong_mgluino_2200_GeV_obs_up">Strong RPV signal, m($\tilde{g}$)=2.2 TeV; observed, $+1\sigma$</a> <a href="?table=excl_strong_mgluino_2200_GeV_obs_down">Strong RPV signal, m($\tilde{g}$)=2.2 TeV; observed, $-1\sigma$</a> <a href="?table=excl_strong_mchi0_50_GeV_exp_nominal">Strong RPV signal, m($\tilde{\chi}^{0}$)=0.1 TeV; expected, nominal</a> <a href="?table=excl_strong_mchi0_50_GeV_exp_up">Strong RPV signal, m($\tilde{\chi}^{0}$)=0.1 TeV; expected, $+1\sigma$</a> <a href="?table=excl_strong_mchi0_50_GeV_exp_down">Strong RPV signal, m($\tilde{\chi}^{0}$)=0.1 TeV; expected, $-1\sigma$</a> <a href="?table=excl_strong_mchi0_50_GeV_obs_nominal">Strong RPV signal, m($\tilde{\chi}^{0}$)=0.1 TeV; observed, nominal</a> <a href="?table=excl_strong_mchi0_50_GeV_obs_up">Strong RPV signal, m($\tilde{\chi}^{0}$)=0.1 TeV; observed, $+1\sigma$</a> <a href="?table=excl_strong_mchi0_50_GeV_obs_down">Strong RPV signal, m($\tilde{\chi}^{0}$)=0.1 TeV; observed, $-1\sigma$</a> <a href="?table=excl_strong_mchi0_450_GeV_exp_nominal">Strong RPV signal, m($\tilde{\chi}^{0}$)=0.5 TeV; expected, nominal</a> <a href="?table=excl_strong_mchi0_450_GeV_exp_up">Strong RPV signal, m($\tilde{\chi}^{0}$)=0.5 TeV; expected, $+1\sigma$</a> <a href="?table=excl_strong_mchi0_450_GeV_exp_down">Strong RPV signal, m($\tilde{\chi}^{0}$)=0.5 TeV; expected, $-1\sigma$</a> <a href="?table=excl_strong_mchi0_450_GeV_obs_nominal">Strong RPV signal, m($\tilde{\chi}^{0}$)=0.5 TeV; observed, nominal</a> <a href="?table=excl_strong_mchi0_450_GeV_obs_up">Strong RPV signal, m($\tilde{\chi}^{0}$)=0.5 TeV; observed, $+1\sigma$</a> <a href="?table=excl_strong_mchi0_450_GeV_obs_down">Strong RPV signal, m($\tilde{\chi}^{0}$)=0.5 TeV; observed, $-1\sigma$</a> <a href="?table=excl_strong_tau_0p01_ns_exp_nominal">Strong RPV signal, $\tau$=0.01 ns; expected, nominal</a> <a href="?table=excl_strong_tau_0p01_ns_exp_up">Strong RPV signal, $\tau$=0.01 ns; expected, $+1\sigma$</a> <a href="?table=excl_strong_tau_0p01_ns_exp_down">Strong RPV signal, $\tau$=0.01 ns; expected, $-1\sigma$</a> <a href="?table=excl_strong_tau_0p01_ns_obs_nominal">Strong RPV signal, $\tau$=0.01 ns; observed, nominal</a> <a href="?table=excl_strong_tau_0p01_ns_obs_up">Strong RPV signal, $\tau$=0.01 ns; observed, $+1\sigma$</a> <a href="?table=excl_strong_tau_0p01_ns_obs_down">Strong RPV signal, $\tau$=0.01 ns; observed, $-1\sigma$</a> <a href="?table=excl_strong_tau_0p1_ns_exp_nominal">Strong RPV signal, $\tau$=0.10 ns; expected, nominal</a> <a href="?table=excl_strong_tau_0p1_ns_exp_up">Strong RPV signal, $\tau$=0.10 ns; expected, $+1\sigma$</a> <a href="?table=excl_strong_tau_0p1_ns_exp_down">Strong RPV signal, $\tau$=0.10 ns; expected, $-1\sigma$</a> <a href="?table=excl_strong_tau_0p1_ns_obs_nominal">Strong RPV signal, $\tau$=0.10 ns; observed, nominal</a> <a href="?table=excl_strong_tau_0p1_ns_obs_up">Strong RPV signal, $\tau$=0.10 ns; observed, $+1\sigma$</a> <a href="?table=excl_strong_tau_0p1_ns_obs_down">Strong RPV signal, $\tau$=0.10 ns; observed, $-1\sigma$</a> <a href="?table=excl_strong_tau_1_ns_exp_nominal">Strong RPV signal, $\tau$=1.00 ns; expected, nominal</a> <a href="?table=excl_strong_tau_1_ns_exp_up">Strong RPV signal, $\tau$=1.00 ns; expected, $+1\sigma$</a> <a href="?table=excl_strong_tau_1_ns_exp_down">Strong RPV signal, $\tau$=1.00 ns; expected, $-1\sigma$</a> <a href="?table=excl_strong_tau_1_ns_obs_nominal">Strong RPV signal, $\tau$=1.00 ns; observed, nominal</a> <a href="?table=excl_strong_tau_1_ns_obs_up">Strong RPV signal, $\tau$=1.00 ns; observed, $+1\sigma$</a> <a href="?table=excl_strong_tau_1_ns_obs_down">Strong RPV signal, $\tau$=1.00 ns; observed, $-1\sigma$</a> <a href="?table=excl_strong_tau_10_ns_exp_nominal">Strong RPV signal, $\tau$=10.00 ns; expected, nominal</a> <a href="?table=excl_strong_tau_10_ns_exp_up">Strong RPV signal, $\tau$=10.00 ns; expected, $+1\sigma$</a> <a href="?table=excl_strong_tau_10_ns_exp_down">Strong RPV signal, $\tau$=10.00 ns; expected, $-1\sigma$</a> <a href="?table=excl_strong_tau_10_ns_obs_nominal">Strong RPV signal, $\tau$=10.00 ns; observed, nominal</a> <a href="?table=excl_strong_tau_10_ns_obs_up">Strong RPV signal, $\tau$=10.00 ns; observed, $+1\sigma$</a> <a href="?table=excl_strong_tau_10_ns_obs_down">Strong RPV signal, $\tau$=10.00 ns; observed, $-1\sigma$</a> <a href="?table=excl_xsec_strong_chi0_1250">Strong RPV signal, m($\tilde{\chi}^0_1$)=1.25 TeV; cross-section limits for fixed lifetime values.</a> <br/><b>Reinterpretation Material:</b> See the attached resource (purple button on the left) or directly <a href="https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2016-08/hepdata_info.pdf">this link</a> for information about acceptance definition and about how to use the efficiency histograms below. SLHA files are also available in the reource page of this HEPData record. <a href="?table=acceptance_highpt_strong"> Acceptance cutflow, High-pT SR, Strong production.</a> <a href="?table=acceptance_trackless_ewk"> Acceptance cutflow, Trackless SR, EWK production.</a> <a href="?table=acceptance_trackless_ewk_hf"> Acceptance cutflow, Trackless SR, EWK production with heavy-flavor.</a> <a href="?table=acceptance_highpt_ewk_hf"> Acceptance cutflow, Trackless SR, EWK production with heavy-flavor.</a> <a href="?table=event_efficiency_HighPt_R_1150_mm">Reinterpretation Material: Event-level Efficiency for HighPt SR selections, R < 1150 mm</a> <a href="?table=event_efficiency_HighPt_R_1150_3870_mm">Reinterpretation Material: Event-level Efficiency for HighPt SR selections, R [1150, 3870] mm</a> <a href="?table=event_efficiency_HighPt_R_3870_mm">Reinterpretation Material: Event-level Efficiency for HighPt SR selections, R > 3870 mm</a> <a href="?table=event_efficiency_Trackless_R_1150_mm">Reinterpretation Material: Event-level Efficiency for Trackless SR selections, R < 1150 mm</a> <a href="?table=event_efficiency_Trackless_R_1150_3870_mm">Reinterpretation Material: Event-level Efficiency for Trackless SR selections, R [1150, 3870] mm</a> <a href="?table=event_efficiency_Trackless_R_3870_mm">Reinterpretation Material: Event-level Efficiency for Trackless SR selections, R > 3870 mm</a> <a href="?table=vertex_efficiency_R_22_mm">Reinterpretation Material: Vertex-level Efficiency for R < 22 mm</a> <a href="?table=vertex_efficiency_R_22_25_mm">Reinterpretation Material: Vertex-level Efficiency for R [22, 25] mm</a> <a href="?table=vertex_efficiency_R_25_29_mm">Reinterpretation Material: Vertex-level Efficiency for R [25, 29] mm</a> <a href="?table=vertex_efficiency_R_29_38_mm">Reinterpretation Material: Vertex-level Efficiency for R [29, 38] mm</a> <a href="?table=vertex_efficiency_R_38_46_mm">Reinterpretation Material: Vertex-level Efficiency for R [38, 46] mm</a> <a href="?table=vertex_efficiency_R_46_73_mm">Reinterpretation Material: Vertex-level Efficiency for R [46, 73] mm</a> <a href="?table=vertex_efficiency_R_73_84_mm">Reinterpretation Material: Vertex-level Efficiency for R [73, 84] mm</a> <a href="?table=vertex_efficiency_R_84_111_mm">Reinterpretation Material: Vertex-level Efficiency for R [84, 111] mm</a> <a href="?table=vertex_efficiency_R_111_120_mm">Reinterpretation Material: Vertex-level Efficiency for R [111, 120] mm</a> <a href="?table=vertex_efficiency_R_120_145_mm">Reinterpretation Material: Vertex-level Efficiency for R [120, 145] mm</a> <a href="?table=vertex_efficiency_R_145_180_mm">Reinterpretation Material: Vertex-level Efficiency for R [145, 180] mm</a> <a href="?table=vertex_efficiency_R_180_300_mm">Reinterpretation Material: Vertex-level Efficiency for R [180, 300] mm</a> <br/><b>Cutflow Tables:</b> <a href="?table=cutflow_highpt_strong"> Cutflow (Acceptance x Efficiency), High-pT SR, Strong production.</a> <a href="?table=cutflow_trackless_ewk"> Cutflow (Acceptance x Efficiency), Trackless SR, EWK production.</a> <a href="?table=cutflow_trackless_ewk_hf"> Cutflow (Acceptance x Efficiency), Trackless SR, EWK production with heavy-flavor quarks.</a> <a href="?table=cutflow_highpt_ewk_hf"> Cutflow (Acceptance x Efficiency), High-pT SR, EWK production with heavy-flavor quarks.</a>
Validation of background estimate in validation regions for the High-pT jet selections
Validation of background estimate in validation regions for the Trackless jet selections
We present the first measurements of transverse momentum spectra of $\pi^{\pm}$, $K^{\pm}$, $p(\bar{p})$ at midrapidity ($|y| < 0.1$) in U+U collisions at $\sqrt{s_{NN}}$ = 193 GeV with the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The centrality dependence of particle yields, average transverse momenta, particle ratios and kinetic freeze-out parameters are discussed. The results are compared with the published results from Au+Au collisions at $\sqrt{s_{NN}} =$ 200 GeV in STAR. The results are also compared to those from A Multi Phase Transport (AMPT) model.
'Identified transverse momentum spectra of $\pi^{+}$ at midrapidity (|y| < 0.1) in U+U collisions at $\sqrt{s_{\rm NN}}$ = 193 GeV'
'Identified transverse momentum spectra of $K^{+}$ at midrapidity (|y| < 0.1) in U+U collisions at $\sqrt{s_{\rm NN}}$ = 193 GeV'
'Identified transverse momentum spectra of p at midrapidity (|y| < 0.1) in U+U collisions at $\sqrt{s_{\rm NN}}$ = 193 GeV'
Measurements of the suppression and correlations of dijets is performed using 3 $\mu$b$^{-1}$ of Xe+Xe data at $\sqrt{s_{\mathrm{NN}}} = 5.44$ TeV collected with the ATLAS detector at the LHC. Dijets with jets reconstructed using the $R=0.4$ anti-$k_t$ algorithm are measured differentially in jet $p_{\text{T}}$ over the range of 32 GeV to 398 GeV and the centrality of the collisions. Significant dijet momentum imbalance is found in the most central Xe+Xe collisions, which decreases in more peripheral collisions. Results from the measurement of per-pair normalized and absolutely normalized dijet $p_{\text{T}}$ balance are compared with previous Pb+Pb measurements at $\sqrt{s_{\mathrm{NN}}} =5.02$ TeV. The differences between the dijet suppression in Xe+Xe and Pb+Pb are further quantified by the ratio of pair nuclear-modification factors. The results are found to be consistent with those measured in Pb+Pb data when compared in classes of the same event activity and when taking into account the difference between the center-of-mass energies of the initial parton scattering process in Xe+Xe and Pb+Pb collisions. These results should provide input for a better understanding of the role of energy density, system size, path length, and fluctuations in the parton energy loss.
The centrality intervals in Xe+Xe collisions and their corresponding TAA with absolute uncertainties.
The centrality intervals in Xe+Xe and Pb+Pb collisions for matching SUM ET FCAL intervals and respective TAA values for Xe+Xe collisions.
The performance of the jet energy scale (JES) for jets with $|y| < 2.1$ evaluated as a function of pT_truth in different centrality bins. Simulated hard scatter events were overlaid onto events from a dedicated sample of minimum-bias Xe+Xe data.
Studies of the correlations of the two highest transverse momentum (leading) jets in individual Pb+Pb collision events can provide information about the mechanism of jet quenching by the hot and dense matter created in such collisions. In Pb+Pb and pp collisions at $\sqrt{s_{_\text{NN}}}$ = 5.02 TeV, measurements of the leading dijet transverse momentum ($p_{\mathrm{T}}$) correlations are presented. Additionally, measurements in Pb+Pb collisions of the dijet pair nuclear modification factors projected along leading and subleading jet $p_{\mathrm{T}}$ are made. The measurements are performed using the ATLAS detector at the LHC with 260 pb$^{-1}$ of pp data collected in 2017 and 2.2 nb$^{-1}$ of Pb+Pb data collected in 2015 and 2018. An unfolding procedure is applied to the two-dimensional leading and subleading jet $p_{\mathrm{T}}$ distributions to account for experimental effects in the measurement of both jets. Results are provided for dijets with leading jet $p_{\mathrm{T}}$ greater than 100 GeV. Measurements of the dijet-yield-normalized $x_{\mathrm{J}}$ distributions in Pb+Pb collisions show an increased fraction of imbalanced jets compared to pp collisions; these measurements are in agreement with previous measurements of the same quantity at 2.76 TeV in the overlapping kinematic range. Measurements of the absolutely-normalized dijet rate in Pb+Pb and pp collisions are also presented, and show that balanced dijets are significantly more suppressed than imbalanced dijets in Pb+Pb collisions. It is observed in the measurements of the pair nuclear modification factors that the subleading jets are significantly suppressed relative to leading jets with $p_{\mathrm{T}}$ between 100 and 316 GeV for all centralities in Pb+Pb collisions.
absolutely normalized dijet cross sections from pp collisions
absolutely normalized dijet yields scaled by 1/<TAA> in 0-10% central PbPb collisions
absolutely normalized dijet yields scaled by 1/<TAA> in 10-20% central PbPb collisions
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