Photon plus jet production has been studied by the D0 and CDF experiments in Run II of the Fermilab Tevatron Collider at a center of mass energy of sqrt{s}=1.96 TeV. Measurements of the inclusive photon plus jet, di-photon and photon plus b jet cross section are presented. They are based on integrated luminosities between 0.2 fb^-1 and 1.1 fb^-1. The results are compared to perturbative QCD calculations in various approximations.
We present preliminary measurements of $Z/γ^*$+jets, $W+c$ and $Z+b+X$ at the Tevatron, and review recent measurements of vector boson plus inclusive and heavy-flavor jets production. All measurements are in agreement with next-to-leading-order QCD calculations within the experimental and theoretical uncertainties. We also point to comparisons of the production rate and kinematics of the data with several Monte Carlo simulation programs of vector boson + jets processes.
The associated production of jets and vector bosons is an important process at hadron colliders. An overview over recent Tevatron vector boson+jets measurements is given with an emphasis on comparisons between data and the predictions of various theory models.
An overview of Run I jet physics at the ppbar Fermilab Tevatron Collider with a particular emphasis on inclusive jet cross section measurements is given. The impact of these studies on PDFs constrain from global fits is underlined. Preliminary results on inclusive jet and di-jet mass cross section measurements in Run II are then summarized.
Study of Jet Properties at the Tevatron (Proceedings of the XIX Rencontres de Physique de La Vallee d'Aoste) In this contribution, a number of new QCD results on jet production from the CDF and D0 experiments in Run II are discussed in detail.
Recent QCD jet production measurements in p-pbar collisions at sqrt(s)=1.96 TeV at the Tevatron Collider at Fermilab are presented. Preliminary: inclusive jet, dijet, isolated photon + jet and Z + jets measurements are compared to available perturbative QCD models.
Results are presented from analyses of jet data produced in pbarp collisions at $\sqrt{s}$ = 1960 GeV collected with the DZero and CDF detectors during 2002--03 at the Fermilab Tevatron Collider. Preliminary measurements of the inclusive jet cross section, the dijet mass spectrum, and jet structure are presented.
In this contribution, a comprehensive review of the main aspects of high pt jet physics in Run II at the Tevatron is presented. Recent measurements on inclusive jet and dijet production are discussed using different jet algorithms and covering a wide region of jet transverse momentum and jet rapidity. Several measurements, sensitive to a proper description of soft gluon radiation and the underlying event in hadron collisions, are also shown.
A brief overview of the latest status of jet physics studies at the Tevatron in proton-antiproton collisions at $\sqrt{s}=1.96$~TeV is presented. In particular, measurements of the inclusive jet production cross-section, dijet production and searches for new physics, the ratio of the 3-jet to 2-jet production cross-sections, and the three-jet mass are discussed.
Selected quantum chromodynamics measurements performed at the Fermilab Run II Tevatron ppbar collider running at sqrt{s}=1.96 TeV by D0 and CDF Collaborations are presented. Events with W/Z+jets productions are used to measure many kinematic distributions allowing extensive tests and tunes of predictions from perturbative QCD at next-to-leading order and Monte-Carlo event generators.
Studies of the production of W/Z + jets are important for a variety of reasons. W/Z + inclusive jets is a valuable high statistics sample that allows one to probe the validity of predictions from perturbative Quantum Chromodynamics (pQCD) at both leading and next-to-leading order. W/Z + heavy flavor jets (those originating from b or c production) is a significant background to top and Higgs at the Tevatron and will play an important role at the LHC as well. Herein the latest Tevatron results on these production mechanisms are reviewed with an emphasis on comparison of data results to the lates…
The systematic uncertainties of the measurements of the Inclusive Jet Cross Section at the Tevatron and their effect on the chi^2 comparisons between data and theoretical predictions are discussed.
A comprehensive overview of the latest aspects of jet physics in proton-antiproton collisions at $\sqrt{s}=$1.96 TeV is presented. In particular, measurements of the inclusive jet production, dijet and multi-jet production, and jet substructure studies are discussed.
Recent results on diffractive dijet and vector boson production and exclusive dijet production from the Collider Detector at Fermilab (CDF) experiment are presented.
Collider signatures containing bosons and jets are particularly interesting. Recent theoretical effort has been devoted to determining predictions of W/Z + multiple parton production; the high statistics sample of W/Z + jets events collected at the Tevatron is a valuable testbed for probing the validity of these calculations. The final state containing a Z or W boson and one or more b-jets is a promising Higgs search channel at the Tevatron and could be a window to new physics at the LHC. These searches benefit from a deep understanding of the production of W/Z + heavy flavor jets which consti…
Results from studies on exclusive production of electron-position pair, di-photon, and di-jet production at CDF in proton-antiproton collisions at the Fermilab Tevatron are presented. The first observation and cross section measurements of exclusive e+e- and di-jet production in hadron-hadron collisions are emphasized.
Jets have been used to verify the theory of quantum chromodynamics (QCD), measure the structure of the proton and to search for the physics beyond the Standard Model. In this article, we review the current status of jet physics at the Tevatron, a sqrt(s) = 1.96 TeV p-pbar collider at the Fermi National Accelerator Laboratory. We report on recent measurements of the inclusive jet production cross section and the results of searches for physics beyond the Standard Model using jets. Dijet production measurements are also reported.
Recent analyses by the CDF and D0 Collaborations of jet data produced in proton-antiproton collisions at the Fermilab Tevatron Collider are presented. These include new studies of the inclusive jet production cross section, a measurement of the strong coupling constant, the first measurement of subjet multiplicity of quark and gluon jets, examination of ratios of multijet cross sections and their implications for choice of renormalization scale, and a study of charged jet evolution and energy flow in the underlying event. The results are compared to theoretical predictions.
Recent measurements of high E_T jet production at the Tevatron are presented. These data provide stringent tests of perturbative QCD as well as constraints on parton distribution functions, the strong coupling constant and models implemented in event generators. Measurements of inclusive jet and multijet production as well as the associated production of jets with the electroweak bosons obtained by both the D0 and CDF collaborations are reviewed.
Measurements of the inclusive jet cross section and the dijet angular distribution using data from the Tevatron are presented. Comparisons to NLO QCD show good agreement below 250 GeV, but CDF data show an excess at higher ET; qualitative agreement is seen between the CDF and DO cross sections. Analysis of the dijet angular distributions exclude quark compositeness below 2.1 TeV.
Results are presented for the inclusive jet cross section versus jet transverse energy in proton-antiproton collisions at center of mass energy 1.8 TeV as measured by the CDF and D0 detectors at Fermilab's Tevatron collider. The data are compared to next-to-leading order QCD predictions using different input parton distribution functions. The ratio of inclusive jet cross sections at center of mass energy 0.63 TeV and center of mass energy 1.8 TeV, versus jet x_T, is also presented and compared to QCD predictions.
We report on recent Z (+jets) measurements from the Fermilab Tevatron proton anti-proton collider. A new D0 measurement of the transverse momentum of Z bosons yields the best measurement to date of the non-perturbative form factor, g2. The production of Z+jets is an major background to many rare signals, and is a vital testing ground for theoretical predictions. Measurements from CDF and D0 of differential cross sections in Z+jet production test NLO pQCD, and in the case of D0, the latest tree-level matrix element with matched parton shower calculations. Improving modelling of this signal will…
We present the most recent W and Z production, asymmetries, and V+jets results from the Tevatron collider at sqrt(s) = 1.96 TeV, analyzing data collected by CDF and DZero detectors between 2002-2011. The results include the measurements of the W and Z bosons properties, include boson p_T and asymmetries measurements, and also the W and Z boson plus jets productions. Those measurements provide the precision tests on the electroweak in Standard Model (SM), and high order theoretical predictions.
Early Run II QCD jet results from D0 and CDF are presented. Inclusive and dijet cross sections have been measured and underlying events have been studied by two different means. While the results to date are consistent with the standard model both experiments are working hard to spot any deviations that may emerge.
Latest jet results from the Tevatron are presented in this conference note. These are namely: new results on central inclusive jet production using both cone and $k_T$ algorithms, measurement of decorrelation in azimuthal angle between the two jets with the highest transverse momenta, and study of jet shapes. Results are based on data collected in $\mathrm{p}\bar{\mathrm{p}}$ collisions at $\sqrt{s}=1.96 \mathrm{TeV}$ in the years 2001-2004. Depending on the analysis, integrated luminosity of the sample was up to $378 \mathrm{pb}^{-1}$.
This document reviews several recent measurements at the Fermilab Tevatron, including the cross sections of inclusive jet, dijet production, the cross sections of electroweak boson (W or Z) production in association with inclusive or heavy-flavor (b or c) jets, and b-jet shapes. In addition, searches for new physics using the dijet angular distributions are discussed. These analyses are based on integrated luminosities of 0.3--2.5/fb of p-pbar collisions at \sqrt{s}=1.96 TeV, collected with the CDF and D0 detectors. The results directly test the leading order and next-to leading order calculat…
The CDF and D0 collaborations performed a comprehensive study of the production of vector bosons, W and Z, in association with energetic jets. Understanding the W/Z + jets and W/Z + c, b-jets processes is of paramount importance for the top quark physics, for the Higgs boson measurements, and for many new physics searches. In this contribution the most recent measurements of the associated production of jets and vector bosons in Run II at the Tevatron are presented. The measurements are compared to different perturbative QCD predictions and to several Monte Carlo generators.
We present results on measurements of jet shapes and jet azimuthal decorrelation from $\overline{p}p$ collisions at $\sqrt{s}=1.8$ TeV using data collected during the 1992--1993 run of the Fermilab Tevatron. Jets are seen to narrow both with increasing $E_T$ and increasing rapidity. While HERWIG, a parton shower Monte Carlo, predicts slightly narrower jets, it describes the trend of the data well; NLO QCD describes qualitative features of the data but is sensitive to both renormalization scale and jet definitions. Jet azimuthal decorrelation has been measured out to five units of pseudorapidit…
We present the results of searches for non-standard model phenomena in photon and jet final states. These searches use data from integrated luminosities of 0.7--2.7/fb of p-pbar collisions at sqrt(s)=1.96 TeV, collected with the CDF and D0 detectors at the Fermilab Tevatron. No significant excess in data has been observed. We report limits on the parameters of several models, including: large extra dimension, compositeness, leptoquarks, and supersymmetry.
Vector boson plus jet production is interesting for Higgs search, beyond the Standard Model physics and provides standard candles for calibration. This is complementary to inclusive jet production measurements which provide precision tests of perturbative QCD. A multitude of W/Z plus heavy and light flavour jet measurements in ppbar collisions at a centre of mass energy of sqrt{s}=1.96TeV is discussed. Next-to-Leading order perturbative QCD predictions and various models are compared to the measurements.
The DØ and CDF experiments have each collected more than 8 fb-in Run II of Fermilab's Tevatron, and have many recent search results which use up to 5.2 fb-1 . Here I summarize the results of a variety of searches for physics beyond the Standard Model with an emphasis on searches for very exotic phenomena. I will present the status of model-inspired searches for several signatures of supersymmetry, as well as several other searches for several "hidden- valley" inspired models, all of which contain photons and jets in the final state.
This contribution reports preliminary jet results in ppbar collisions at sqrt(s)=1.96 TeV from the CDF and D0 experiments. The jet inclusive cross section, measured using both the Midpoint and the K_T jet clustering algorithm, is compared to next-to-leading order QCD prediction in different rapidity regions. The b-jet inclusive cross section measured exploiting the long lifetime and large mass of B hadrons is presented and compared to QCD prediction. A complementary measurement, using the large branching fraction of B hadrons into muons, is also described. The measurement of two-particle momen…
At the Fermilab Tevatron energies, ($\sqrt{s}$=1800 GeV and $\sqrt{s}$=630 GeV), jet production is the dominant process. During the period 1992-1996, the D0 and CDF experiments accumulated almost 100 pb**-1 of data and performed the most accurate jet production measurements up to this date. These measurements and the NLO-QCD theoretical predictions calculated during the last decade, have improved our understanding of QCD, our knowledge of the proton structure, and pushed the limit to the scale associated with quark compositeness to 2.4-2.7 TeV. In this paper, we present the most recent publish…
Recent measurements on the vector boson plus heavy-flavor jets production by the CDF and D0 experiments are presented in comparisons with recent theoretical predictions. Good understanding of such processes is important to improve our understanding of QCD and also to enhance the potential to search for yet-to-be-discovered new physics phenomena which lead to similar final states.
High energy jet distributions measured since 1992 at the Fermilab Tevatron proton--antiproton collider are presented and compared to theoretical predictions. The statistical uncertainties on these measurements are significantly reduced relative to previous results. The systematic uncertainties are comparable in size to the uncertainty in the theoretical predictions. Although some discrepancies between theory and measurements are noted, the inclusive jet and dijet cross sections can be described by quantum chromodynamics. Prospects for reducing the uncertainty in the theoretical predictions by …
We study the effect of application of new set of cuts, proposed in our previous works, on the improvement of accuracy of the jet energy calibration with p p->photon+Jet+X process at Tevatron. Monte Carlo events produced by the PYTHIA 5.7 generator are used for this aim. The selection criteria for photon+Jet event samples that would provide a good balance of photon and jet transverse momenta and would allow to reduce the background are described. The distributions of these events over photon transverse momenta and jet pseudorapidity are presented. The features of photon+Jet events in the centra…
The number of photon+jet and Z+jet events suitable for a determination of gluon distribution function in a proton at Tevatron Run II and during the low luminosity runs at future LHC experiments are estimated for various intervals of x and Q^2. These numbers allow to extract gluon distribution in new kinematic regions of 2 * 10^{-3} < x < 1.0 with 1.6*10^3 < Q^2 < 2*10^4 \~(GeV/c)^2 at Tevatron and of 2* 10^{-4} < x < 1.0$ with 1.6*10^3 < Q^2 < 2*10^5 ~(GeV/c)^2 at LHC. The contributions of background events in different Q^2 intervals are also given.
We report a new measurement of the pseudorapidity (eta) and transverse- energy (Et) dependence of the inclusive jet production cross section in pbar p collisions at sqrt(s)=1.8 TeV using 95 pb**-1 of data collected with the D0 detector at the Fermilab Tevatron. The differential cross section d^2sigma/(dEt deta) is presented up to |eta|=3, significantly extending previous measurements. The results are in good overall agreement with next-to-leading order predictions from QCD, indicate a preference for certain parton distribution functions, and provide the world's best constraint on the gluon dis…
We present a more detailed account of our study (hep-ph/9903238) for the supersymmetry reach of the Tevatron in channels with isolated leptons and identified tau jets. We review the theoretical motivations for expecting such signatures, and describe the relevant parameter space in the minimal supergravity and the minimal gauge-mediated models. With explicit Monte Carlo simulations we then show that for certain parameter ranges, channels with two leptons and one tau jet offer a better reach in Run II than the clean trilepton signal. We emphasize than improving on tau ID is an important prerequi…
Recent searches performed by the CDF and D0 collaborations at the Tevatron for diboson production in final states containing heavy-flavor jets are reported. The searches for WZ and ZZ can be regarded as the ultimate benchmark for the corresponding searches for a low-mass Higgs boson in the WH and ZH final states. Using the exact same techniques as for those Higgs boson searches, the D0 collaboration measured a cross section for WZ/ZZ production of 1.13 +/- 0.36 times its expectation in the standard model, with a diboson signal significance of 3.3 standard deviations (2.9 expected).
Several sources, both experimental and theoretical, subject inclusive jet cross section measurements to large uncertainties. On the experimental side, the energy scale contributes between 10% and 30% uncertainties. On the theoretical side, choice of parton distribution function introduces a 20% variation in the prediction; freedom in renormalization scale provides another uncertainty of up to 30%. The ratio of inclusive jet cross sections reduces the uncertainty from these major sources, permitting a very precise test of next-to-leading order QCD. The preliminary results from DØand CDF differ …
The consequences of application of new set of criteria, proposed in our previous works, for the improvement of a jet energy calibration accuracy with the process "p~p->photon+jet+X" at Tevatron and for a reduction of background events contribution are studied. The efficiencies of the used selection criteria are estimated. The distributions of these events over photon Pt and jet pseudorapidity are presented. The features of "photon+jet" events in the central calorimeter region of the D0 detector (|η|<0.7) are investigated. It is also shown that the samples of "photon+jet" events, selected with …
This article summarizes several analyses I discussed at Moriond and I attempt to maintain my speaking voice throughout. I extract several broad themes in the recent development of QCD,and emphasize how the latest results on jet physics reinforce these themes: that QCD is in a transitional stage from providing qualitative descriptions to providing true quantitative descriptions of the results. Certain figures presented in the talk are not reproduced here in the interest of space, but can be found directly in the transparencies available online, or in the references to the refereed journals.
An overview of latest top quark pair production cross-sections measured at the Tevatron is given. These measurements have been carried out in the dilepton, lepton+jets and all-jets channels with an integrated luminosity of about 1fb-1. The measurements are consistent with NNLO calculations.
Recent measurements of selected QCD processes at the Tevatron are reviewed and confronted with theoretical calculations. Results on inclusive jet production at large transverse momentum are compared to predictions from next-to-leading order perturbative QCD. Kinematic distributions of jets with light and heavy flavor produced in association with electroweak bosons are compared to expectations from leading-order QCD calculations supplemented with parton-shower models. Properties of QCD radiation in hard-scatter events are investigated using azimuthal correlations between two leading jets in mul…
The latest top quark mass measurements by the CDF and DØ~ experiments are presented here. The mass has been determined in the dilepton ($\ttbar \to eμ,ee,μμ$ + jets +$\met$) and lepton plus jets ($\ttbar \to e$ or $μ$ + jets +$\met$) final states. The most accurate single result from lepton plus jets channel is 173.5$^{+3.7}_{-3.6}$(stat. + Jet Energy Scale Systematic)$\pm1.3$(syst.) ~GeV/c$^{2}$, which is better than the combined CDF and DØ~ Run~I average. A preliminary and unofficial average of the best experimental Run~II results gives $M_{top}$ = $172.7\pm3.5$ GeV/c${^2}$.
The latest results on the measurements of electroweak top-quark production at the Tevatron are presented with the full RunII dataset. The CDF and D0 Collaborations have performed measurements of the s, t, and s+t channels in both l+jets and MET+jets final states. Evidence for the production of the s channel is presented for the first time.
Since a lot of theoretical predictions on the production of new particles (Higgs, SUSY) at the Tevatron are based on model estimations of the proton gluon density behavior at low $x$ and high values of a transfered momentum Q^2, the study of a possibility of a measurement of the gluon density in this kinematic region directly in Tevatron experiments is obviously of a big interest [1]. Basing on the selection criteria proposed ealier in [1,2], the background events suppression factors and corresponding signal events selection efficiencies are determined here. The estimation of the number of pho…
We study the impact of Tevatron jet data on a global fit of parton distribution functions and on the determination of the value of the strong coupling constant. The consequences are illustrated for cross sections of Higgs boson production at Tevatron and the LHC.
We present three recent photon analyses from data collected at the Fermilab Tevatron: measurements of the direct photon pair production cross section at CDF and D0, measurements of azimuthal decorrelations and multiple parton interactions in gamma + 2 jet and gamma + 3 jet events at D0, and an observation of exclusive diphoton production at CDF.
We present a summary of recent measurements of $W$ and $Z$ properties and $W/Z$ production in association with jets in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV with the CDF and DØ detectors. Latest measurements of $Z/γ^*$ transverse momentum and are presented along with new measurements of the angular distributions of final state electrons from Drell Yan events as a way to probe $Z$ boson production mechanisms. The mass dependence of the forward-backward asymmetry in $p\bar{p} \rightarrow Z/γ^{*} \rightarrow e^+e^-$ interactions is measured, the effective weak mixing angle extracted, and t…
We present a summary of the most recent measurements relevant to Quantum Chromodynamics (QCD) delivered by the D0 and CDF Tevatron experiments by May 2008. CDF and D0 are moving toward precision measurements of QCD based on data samples in excess of 1 fb-1. The inclusive jet cross sections have been extended to forward rapidity regions and measured with unprecedented precision following improvements in the jet energy calibration. Results on dijet mass distributions, bbbar dijet production using tracker based triggers, underlying event in dijet and Drell-Yan samples, inclusive photon and diphot…
We present measurements of the top-antitop production cross section in b-tagged lepton + jets events from proton-antiproton collisions at 1.96 TeV using the CDF detector at Fermilab. B-jets are tagged with either a secondary vertex algorithm, or a soft lepton tagger that identifies muons from B hadron semileptonic decays. With Tevatron Run II data, we estimate the top-antitop signal fraction in two different ways: by estimating the various background contributions, and by fitting directly the leading jet transverse energy spectrum for the signal and background contributions. A subset of the sa…
Tevatron diboson measurements are reviewed, and new or recent results reported for Wgamma, Zgamma, and ZZ production in the leptonic decay modes, and for WW/WZ production in the lepton plus jets decay mode. The most stringent limits on anomalous triple gauge couplings are reported for each final state.
We present a measurement of the inclusive jet cross section in p-pbar collisions at sqrt{s}=1.96 TeV based on data collected by the CDF II detector with an integrated luminosity of 1.13 fb^-1. The measurement was made using the cone-based Midpoint jet clustering algorithm in the rapidity region of |y|<2.1. The results are consistent with next-to-leading-order perturbative QCD predictions based on recent parton distribution functions (PDFs), and are expected to provide increased precision in PDFs at high parton momentum fraction x. The results are also compared to the recent inclusive jet cross…
We show that the W p_T distribution measured by D0 at the Tevatron agrees well with the NLO QCD theoretical prediction for this quantity, whilst the W + 1 jet/ W + 0 jet ratio, R^10, measured by D0 lies significantly above the NLO QCD theoretical prediction. We derive an approximate relationship between these two quantities, and show that this rules out the majority of theoretical explanations for the D0 excess in R^10. We discuss possible physics that could give rise to the R^10 excess, which have little effect on the W p_T.
We report a measurement of the strong coupling constant, $α_s(M_Z)$, extracted from inclusive jet production in $p\bar{p}$ collisions at $\sqrt{s}=$1800 GeV. The QCD prediction for the evolution of $α_s$ with jet transverse energy $E_T$ is tested over the range 40<$E_T$<450 GeV using $E_T$ for the renormalization scale. The data show good agreement with QCD in the region below 250 GeV. In the text we discuss the data-theory comparison in the region from 250 to 450 GeV. The value of $α_s$ at the mass of the $Z^0$ boson averaged over the range 40<$E_T$<250 GeV is found to be $α_s(M_{Z})= 0.1178 …
Results on recent QCD measurements performed at the Tevatron ppbar Collider at sqrt{s} = 1.96 TeV are here reported. The inclusive jet and dijet mass cross sections are compared to NLO pQCD calculations and to Run I results. The production rates and kinematic properties of W + jets production processes are compared to ``enhanced'' LO theoretical predictions. Non-perturbative ``soft'' interactions leading to the underlying event are studied and compared to QCD Monte Carlo phenomenological models.
Recent QCD related results from the CDF and the D0 experiments are presented based on proton anti-proton collision data at sqrt(s)=1.96 TeV, taken in Run II of the Fermilab Tevatron Collider. Measured observables include inclusive photon and diphoton production, vector boson plus jets production, event shape variables, and inclusive multijet production. The measurement results are compared to QCD theory calculations in different approximations. A determination of the strong coupling constant from jet data is presented.
