We report on a measurement of the fraction of events with a W or Z boson which are produced diffractively in antiproton-proton collisions at a center of mass energy of 1.96 TeV, using data from 0.6 inverse femtobarns of integrated luminosity collected with the CDF-II detector equipped with a Roman-pot spectrometer that detects the antiproton (pbar) from pbar+p --> pbar+[X+W/Z]. We find that (1.00+/- 0.11)% of Ws and (0.88+/-0.22)% of Zs are produced diffractively in a region of antiproton or proton fractional momentum loss (ξ) of 0.03<ξ<0.10 and 4-momentum transferred squared t of -1<t<0 (GeV/c)^2, where we account for the events in which the proton scatters diffractively while the antiproton dissociates, pbar+p --> [X+W/Z]+p, by doubling the measured proton dissociation fraction. We also report on searches for W and Z production in double Pomeron exchange, p+pbar --> p+[X+W/Z]+pbar, and on exclusive Z production, pbar+p --> pbar+Z+p. No signal is seen above background for these processes, and comparisons are made with expectations.
Results from the Fermilab Tevatron pbar-p collider on diffractive and total cross sections are reviewed with emphasis on physics significance and properties pointing to expectations at the LHC.
Recent results on diffractive dijet and vector boson production and exclusive dijet production from the Collider Detector at Fermilab (CDF) experiment are presented.
We report new results from CDF on single-diffractive dijet and W/Z production, and on exclusive dijet, diphoton, and dilepton production in proton-antiproton collisions at sqrt{s}=1.96 TeV at the Fermilab Tevatron. The measured exclusive dijet and diphoton cross sections provide a test of theoretical predictions for exclusive Higgs production at the LHC.
We review hard diffractive results and prospects at the Tevatron with an emphasis on factorization breaking in diffractive processes. Upper limits on the exclusive di-jet and chi_c^0 production cross sections at CDF and the status of the D0 Forward Proton Detectors are discussed.
The Forward Detector upgrade project at CDF is designed to enhance the capabilities for studies of diffractive physics at the Tevatron during Run II. Studies of hard diffraction and very forward physics are some of the topics that can be addressed in the next few years at the Tevatron. The program for diffractive physics, including the detectors and their commissioning, is discussed here. All the detectors have been installed and are presently collecting data.
Results on hard diffraction from CDF are reviewed with emphasis on the determination of the diffractive structure function of the (anti)proton from single diffractive and double Pomeron exchange dijet production. Comparison of the diffractive dijet results with predictions based on diffractive deep inelastic scattering at HERA shows a breakdown of conventional QCD factorization. A similar breakdown is observed within the CDF results in comparing the structure functions obtained from single diffraction and double Pomeron exchange.
Preliminary results on diffractive W and Z production in proton-antiproton collisions at a c.m.s. energy of 1.96 TeV are presented and discussed. Differential cross sections are measured from data collected with the CDF-II detector at the Fermilab Tevatron collider using a Roman pot spectrometer that detects leading antiprotons. The ratio of diffractive to total W production rates (diffractive fraction) agrees with that measured by CDF in Run-I using a rapidity gap diffractive signature. The W and Z diffractive fractions are equal within the measurement uncertainties, which are dominated by a …
The CDF and DØcollaborations continue to search for new physics using more than 100~pb$^{-1}$ of \xxbar{p} collisions at $\sqrt{s}=1.8$ TeV collected at the Fermilab Tevatron. We present recent results from both experiments on R-parity violating Supersymmetry and $Z'$/Technicolor production with $ee$ and \xxbar{t} final states. In addition we introduce Sherlock, a new quasi-model-independent search strategy.
Hard diffraction in events with dijets and rapidity gaps has been studied by DØand CDF for three processes: hard color singlet exchange, hard single diffraction, and hard double pomeron exchange, using Tevatron $\bar pp$ data at $\sqrt{s}$ = 630 GeV and 1.8 TeV. Measurements of rates, $η, E_T$ and $\sqrt{s}$ dependencies are presented and comparisons made with predictions of several models.
We report the first observation of diffractive $J/ψ(\to μ^+μ^-)$ production in $\bar pp$ collisions at $\sqrt{s}$=1.8 TeV. Diffractive events are identified by their rapidity gap signature. In a sample of events with two muons of transverse momentum $p_T^μ>2$ GeV/$c$ within the pseudorapidity region $|η|<$1.0, the ratio of diffractive to total $J/ψ$ production rates is found to be $R_{J/ψ}= [1.45\pm 0.25]%$. The ratio $R_{J/ψ}(x)$ is presented as a function of $x$-Bjorken. By combining it with our previously measured corresponding ratio $R_{jj}(x)$ for diffractive dijet production, we extract …
This paper reviews recent measurements by the D0 and CDF collaborations in pbarp collisions at the Fermilab Tevatron at sqrt{s} = 1.96 TeV of W and Z boson production cross sections and asymmetries. Results from both experiments for the search of the Higgs boson predicted by the standard model in four different decay channels are also presented.
This talk at the XVIII International Conference on Physics in Collision, Frascati, Italy, June 17-19, 1998, presents CDF and D0 results on W and Z Boson Production Cross Sections, the W Boson Width, Rare W Boson Decays, Trilinear Gauge Boson Couplings, and the W Boson Mass.
This article contains a summary of the recent results in diffractive physics at the Tevatron. Results from the CDF diffraction program include the single diffractive to non-diffractive ratio in dijet events, observation of exclusive $e^+e^-$ production via two-photon exchange, hints of exclusive $γγ$ production via Double Pomeron Exchange (DPE), and the observation of exclusive dijet production via DPE. A summary of the current plans for the DØ diffractive physics program is also presented.
The \d0 (DZERO) Detector at Fermilab is currently collecting data since March 1, 2001, called Run 2. The detector has undergone an extensive upgrade to participate in the Run 2 data taking. The design of the detector meets the requirements of the high luminosity environment provided by the accelerator. This paper describes the upgraded detector subsystems and gives an outline of the physics potentials associated with the upgrade.
Searching for and potential discovery of Higgs boson(s) both within and beyond the standard model is perhaps the most visible physics goal of the current Fermilab Tevatron program. In this proceeding, recent results from both the CDF and DØexperiments based on analyses of datasets with integrated luminosities between 1.7 and 3.0 fb$^{-1}$ are summarized. The combined Tevatron cross section upper limits on the production of a standard model Higgs boson are fast approaching the expected standard model values for a wide mass range. Particularly, the Tevatron has now excluded a standard model Higg…
We present results from a measurement of double diffraction dissociation in $\bar pp$ collisions at the Fermilab Tevatron collider. The production cross section for events with a central pseudorapidity gap of width $Δη^0>3$ (overlapping $η=0$) is found to be $4.43\pm 0.02{(stat)}{\pm 1.18}{(syst) mb}$ [$3.42\pm 0.01{(stat)}{\pm 1.09}{(syst) mb}$] at $\sqrt{s}=1800$ [630] GeV. Our results are compared with previous measurements and with predictions based on Regge theory and factorization.
This writeup is an introduction to some of the experimental issues involved in performing electroweak and B physics measurements at the Fermilab Tevatron. In the electroweak sector, we discuss W and Z boson cross section measurements as well as the measurement of the mass of the W boson. For B physics, we discuss measurements of B^0/\bar{B^0} mixing and CP violation. This paper is geared towards nonexperts who are interested in understanding some of the issues and motivations for these measurements and how the measurements are carried out.
We report the first observation of diffractively produced W bosons. In a sample of W -> e nu events produced in p-barp collisions at sqrt{s}=1.8 TeV, we find an excess of events with a forward rapidity gap, which is attributed to diffraction. The probability that this excess is consistent with non-diffractive production is 1.1 10^{-4} (3.8 sigma). The relatively low fraction of W+Jet events observed within this excess implies that mainly quarks from the pomeron, which mediates diffraction, participate in W production. The diffractive to non-diffractive W production ratio is found to be R_W=(1.…
This paper presents a review of the study of Exclusive Central Production at a Center of Mass energy of $\sqrt{s}=40$ GeV at the Fermilab Fixed Target program. In all reactions reviewed in this paper, protons with an energy of 800 GeV were extracted from the Tevatron accelerator at Fermilab and directed to a Liquid Hydrogen target. The states reviewed include $π^+π^-$, $K^0_s K^0_s$, $ K^0_sK^\pmπ^\mp$, $ϕϕ$ and $D^{*\pm}$. Partial Wave Analysis results will be presented on the light states but only the cross section will be reviewed in the diffractive production of $D^{*\pm}$
The standard model is a successful but limited theory. There is significant theoretical motivation to believe that new physics may appear at the energy scale of a few TeV, the lower end of which is currently probed by the Fermilab Tevatron Collider. The methods used to search for physics beyond the standard model in a model independent way and the results of these searches based on 1.0 fb-1 of data collected with the D0 detector and 2.0 fb^-1 at the CDF detector are presented.
We address known discrepancies between the heavy flavor properties of jets produced at the Tevatron collider and the prediction of conventional-QCD simulations. In this study, we entertain the possibility that these effects are real and due to new physics. We show that all anomalies can be simultaneously fitted by postulating the additional pair production of light bottom squarks with a 100% semileptonic branching fraction.
We present an idea for a future D0-D0bar mixing and CP violation experiment to run at the Fermilab Tevatron. We estimate that in three years of running, such an experiment could reconstruct an order of magnitude more flavor-tagged D0->K+pi- decays than will be reconstructed by the B-factory experiments with their full data sets. The resulting sensitivity to CP-violating parameters |q/p| and Arg(q/p) is calculated from a global fit to CP-violating observables, and it is found to be much greater than current world sensitivity.
We report results of a search for particles with anomalously high ionization in events with a high transverse energy jet and large missing transverse energy in $2.4$ fb$^{-1}$ of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron $p\bar{p}$ collider. Production of such particles (quirks) is expected in scenarios with extra QCD-like {\it SU(N)} sectors, and this study is the first dedicated search for such signatures. We find no evidence of a signal and set a lower mass limit of 107 ~GeV for the mass of a charged quirk with strong dynamics scale $Λ$ in the range from …
The top quark, discovered at the Tevatron in 1995, is a very interesting particle. Precise measurement of the top properties using large data samples will allow stringent tests of the Standard Model and offer a unique window on new physics. In this report will be reviewed the status of the current knowledge of the top quark as provided by the Run I results of the CDF and D0 experiment. A first look at various preliminary measurements obtained with data collected during Run II will be also presented.
We report a measurement of the diffractive structure function $F_{jj}^D$ of the antiproton obtained from a study of dijet events produced in association with a leading antiproton in $\bar pp$ collisions at $\sqrt s=630$ GeV at the Fermilab Tevatron. The ratio of $F_{jj}^D$ at $\sqrt s=630$ GeV to $F_{jj}^D$ obtained from a similar measurement at $\sqrt s=1800$ GeV is compared with expectations from QCD factorization and with theoretical predictions. We also report a measurement of the $ξ$ ($x$-Pomeron) and $β$ ($x$ of parton in Pomeron) dependence of $F_{jj}^D$ at $\sqrt s=1800$ GeV. In the re…
Preliminary results from the D0 experiment on jet production with rapidity gaps in $p\bar{p}$ collisions are presented. A class of dijet events with a forward rapidity gap is observed at center-of-mass energies $\sqrt{s}$ = 1800 GeV and 630 GeV. The number of events with rapidity gaps at both center-of-mass energies is significantly greater than the expectation from multiplicity fluctuations and is consistent with a hard single diffractive process. A class of events with two forward gaps and central dijets are also observed at 1800 GeV. This topology is consistent with hard double pomeron exch…
This paper summarizes the main current upgrade for Diffractive Physics at Tevatron. We describe both CDF and D0 new devices that are being installed around the CDF and D0 area that will allow to produce new results in Diffractive Physics.
First evidence for single top quark production has recently been found by both the D0 and CDF experiments. By combining three analyses, D0 measured a cross section of 4.7 +- 1.3 pb, with a significance of 3.6 standard deviations, and CDF's matrix elements analysis measured a cross section of 3.0 +1.2 -1.1 pb, with a significance of 3.1 standard deviations. These analyses also provided the first direct measurements of the CKM matrix element, |Vtb|, without assuming unitarity. This talk briefly describes the latest single top production results from the two experiments.
Fermilab operates the world's most intense source of antiprotons. Recently various experiments have been proposed that can use those antiprotons either parasitically during Tevatron Collider running or after the Tevatron Collider finishes in about 2010. We discuss the physics goals and prospects of the proposed experiments.
We present results from MiniMax (Fermilab T-864), a small test/experiment at the Tevatron designed to search for the production of disoriented chiral condensate (DCC) in $p - \bar p$ collisions at $\sqrt{s} = 1.8$ TeV in the forward direction, $\sim 3.4 < η< \sim 4.2$. Data, consisting of $1.3 \times 10^6$ events, are analyzed using the robust observables developed in an earlier paper. The results are consistent with generic, binomial-distribution partition of pions into charged and neutral species. Limits on DCC production in various models are presented.
Recent advances in superconductor properties and superconducting magnet technology have made it possible to build cost-effective, high-performance dipoles with a field of 12 Tesla - 3 times the field strength of the Tevatron. Such magnets could be used to upgrade Fermilab's collider in its existing tunnel to a collision energy $\sqrt s$= 6 TeV and luminosity {$\cal L$}$>$ 10$^{33}$ cm$^{-2}$s$^{-1}$. We have calculated the parton luminosities for quark-antiquark and gluon-gluon scattering for the Tevatron, the Tripler, and LHC. In most models of the Higgs field and supersymmetry, the Tripler w…
We consider the hadroproduction of chi_{c1} and chi_{c2} mesons and their subsequent radiative decays to J/psi mesons and photons in the factorization formalism of nonrelativistic quantum chromodynamics, and study the decay angular distributions, by means of helicity density matrices, in view of their sensitivity to color-octet processes. We present numerical results appropriate for the Fermilab Tevatron.
At the Tevatron, the total p_bar-p cross-section has been measured by CDF at 546 GeV and 1.8 TeV, and by E710/E811 at 1.8 TeV. The two results at 1.8 TeV disagree by 2.6 standard deviations, introducing big uncertainties into extrapolations to higher energies. At the LHC, the TOTEM collaboration is preparing to resolve the ambiguity by measuring the total p-p cross-section with a precision of about 1 %. Like at the Tevatron experiments, the luminosity-independent method based on the Optical Theorem will be used. The Tevatron experiments have also performed a vast range of studies about soft an…
Results from a phenomenological analysis of dijet and W hard diffractive hadroproduction at Fermilab Tevatron energies are reported. The theoretical framework employed here is a modified version of the Ingelman-Schlein approach which includes DGLAP-evolved structure functions. Different from what has been achieved by the DESY ep HERA reactions, a reasonable overall description of such diffractive hadron processes is obtained only when a complex, quark-rich Pomeron structure function is employed in the calculation.
We present the first NLO QCD analysis of single-diffractive dijet production in proton-antiproton collisions. By comparing the ratio of single- and non-diffractive cross sections to data from the Tevatron, the rapidity-gap survival probability is determined as a function of the momentum fraction of the parton in the antiproton. Assuming Regge factorization, this probability can be interpreted as a suppression factor for the diffractive structure function measured in deep-inelastic scattering at HERA. In contrast to the observations for photoproduction, the suppression factor in proton-antiprot…
We perform a NLO QCD analysis of single-diffractive dijet production in proton-antiproton collisions. By comparing the ratio of single- and non-diffractive cross sections to data from the Tevatron, the rapidity-gap survival probability is determined as a function of the momentum fraction of the parton in the antiproton. Assuming Regge factorization, this probability can be interpreted as a suppression factor for the diffractive structure function measured in deep-inelastic scattering at HERA. In contrast to the observations for photoproduction, the suppression factor in proton-antiproton colli…
We have searched in $p \bar{p}$ collisions at $\sqrt{s}$ = 1.8 TeV for events with three charged leptons and missing transverse energy. In the Minimal Supersymmetric Standard Model, we expect trilepton events from chargino-neutralino ($\chione \chitwo$) pair production, with subsequent decay into leptons. We observe no candidate $e^+e^-e^\pm$, $e^+e^-μ^\pm$, $e^\pmμ^+μ^-$ or $μ^+μ^-μ^\pm$ events in 106 pb$^{-1}$ integrated luminosity. We present limits on the sum of the branching ratios times cross section for the four channels: $σ_{\chione\chitwo}\cdot $BR$(\chione\chitwo\to 3\ell+X) < 0.34$~…
We present a search for associated production of Higgs and $W$ bosons in $p\bar{p}$ collisions at a center of mass energy of $\sqrt{s}=1.96$ TeV in 5.3 fb$^{-1}$ of integrated luminosity recorded by the D0 experiment. Multivariate analysis techniques are applied to events containing one lepton, an imbalance in transverse energy, and one or two $b$-tagged jets to discriminate a potential $WH$ signal from standard model backgrounds. We observe good agreement between data and background, and set an upper limit of 4.5(at 95% confidence level and for $m_H=115$ GeV) on the ratio of the $WH$ cross se…
We estimate the Tevatron Run II potential for top and bottom squark searches. We find an impressive reach in several of the possible discovery channels. We also study some new channels which may arise in non-conventional supersymmetry models. In each case we rely on a detailed Monte Carlo simulation of the collider events and the CDF detector performance in Run I.
We present the most recent results of searches for physics beyond the Standard Model using the CDF and the D$\not$O detector at the Fermilab Tevatron Collider. All results shown correspond to analysis performed using the past 1992-1996 Fermilab Tevatron run I data (roughly 110 $pb^{-1}$ per each experiment). In particular we report on searches for scalar top and scalar bottom particles together with other {\it classic} Supersymmetry analysis. Results from non Standard Model Higgs searches are also summarized.
We report a measurement of the fraction of events with a large pseudorapidity gap $Δη$ within the pseudorapidity region available to the proton dissociation products $X$ in $\bar p+p\to \bar p+X$. For a final state $\bar p$ of fractional momentum loss $ξ_{\bar p}$ and 4-momentum transfer squared $t_{\bar p}$ within $0.06<ξ_{\bar p}<0.09$ and $|t_{\bar p}|<1.0$ [0.2] GeV$^2$ at $\sqrt s=1800$ [630] GeV, the fraction of events with $Δη>3$is found to be $0.246\pm 0.001 {\rm (stat)}\pm 0.042 {\rm (syst)}$ [$0.184\pm 0.001 {\rm (stat)}\pm 0.043 {\rm (syst)}$]. Our results are compared with gap frac…
We present evidence for the diffractive processes nu_mu Fe -> mu^- D_s^+ (D_s^*+) Fe and nubar_mu Fe -> mu^+ D_s^- (D_s^*-) Fe using the Fermilab SSQT neutrino beam and the Lab E neutrino detector. We observe the neutrino trident reactions nu_mu Fe -> nu_mu mu^- mu^+ Fe and nubar_mu Fe -> nubar_mu mu^+ mu^- Fe at rates consistent with Standard Model expectations. We see no evidence for neutral-current production of J/psi via either diffractive or deep inelastic scattering mechanisms.
We present the first observation and cross section measurement of exclusive dijet production in pbar-p interactions, pbar + p --> pbar + dijet + p. Using a data sample of 310 pb-1 collected by the Run II Collider Detector at Fermilab at sqrt{s}=1.96 TeV, exclusive cross sections for events with two jets of transverse energy ET >= 10 GeV have been measured as a function of minimum ET(jet). The exclusive signal is extracted from fits to data distributions based on Monte Carlo simulations of expected dijet signal and background shapes. The simulated background distribution shapes are checked in a…
We study the neutral Higgs boson production via the gluon fusion process with the $\tautau$ final state at the upgraded Fermilab Tevatron, including a complete simulation of signal channels and leading background processes. For the SM Higgs boson, this $h\to \tautau$ channel may provide important addition for the Higgs boson discovery in the mass range 120-140 GeV. In minimal supersymmetric models, natural enhancement for the signal rate over the SM expectation makes the $h,H,A\to \tautau$ signal observable for large $\tanβ$ and low $M_A$, which may lead to full coverage for SUSY Higgs paramet…
Fermilab operates the world's most intense antiproton source. Newly proposed experiments can use those antiprotons either parasitically during Tevatron Collider running or after the Tevatron Collider finishes in about 2010. In particular, the annihilation of 8 GeV antiprotons might make the world's most intense source of tagged $D^0$ mesons, and thus the best near-term opportunity to study charm mixing and, via CP violation, to search for new physics; a Penning trap and atom interferometer could be used to measure for the first time the gravitational force on antimatter.
We report a study of $\bar p+p\to \bar p+X+Y$ at $\sqrt s=1800$ GeV, where $Y$ is a proton or system of mass-squared $M_Y^2\lesssim 8$ GeV$^2$. In a sample of events with a leading $\bar p$ of fractional momentum loss $0.035<ξ_{\bar p}<0.095$ and 4-momentum transfer squared $|t_{\bar p}|<1.0$ GeV$^2$, the proton fractional momentum loss $ξ_p^X$ to the system $X$ was evaluated from the momenta of the particles comprising $X$. In the region $ξ_p^X<0.02$, the $ξ_p^X$ distribution behaves as $\sim 1/(ξ_p^X)^{1.1}$, as expected for double Pomeron exchange. The fraction of events with $ξ_p^X<0.02$ i…
Hadronic processes in which hard diffractive production takes place have been observed and analyzed in collider experiments for several years. The experimental rates of diffractive W's and dijets measured at the Tevatron and the cross sections of diffractively produced dijets recently obtained at the HERA experiment are the object of this analysis. We use the Pomeron structure function obtained from the HERA data by two different approaches to calculate the rates and cross sections for these processes. The comparison of theoretical predictions with the measured values reveals some discrepancie…
The Fermilab Tevatron collider's data-taking run ended in September 2011, yielding a dataset with rich scientific potential. The CDF and D0 experiments each have approximately 9 PB of collider and simulated data stored on tape. A large computing infrastructure consisting of tape storage, disk cache, and distributed grid computing for physics analysis with the Tevatron data is present at Fermilab. The Fermilab Run II data preservation project intends to keep this analysis capability sustained through the year 2020 and beyond. To achieve this goal, we have implemented a system that utilizes virt…
Results on diffractive scattering observed at HERA and at the TEVATRON are reviewed. This includes the extraction of diffractive parton density functions and determination of the rapidity gap survival probability at HERA and the observation of central exclusive production of final states at the TEVATRON. Finally, preparations to observe diffractive signals at the LHC are discussed.
Top quark pair production at proton-antiproton colliders is known to exhibit a forward-backward asymmetry due to higher-order QCD effects. We explore how this asymmetry might be studied at the Fermilab Tevatron, including how the asymmetry depends on the kinematics of extra hard partons. We consider results for top quark pair events with one and two additional hard jets. We further note that a similar asymmetry, correlated with the presence of jets, arises in specific models for parton showers in Monte Carlo simulations. We conclude that the measurement of this asymmetry at the Tevatron will b…
This paper discusses supersymmetry discovery potential of the upgraded DØexperiment at the Tevatron $p\bar{p}$ collider. Six final states with large transverse energy (momentum) leptons or photons (with or without large transverse momentum imbalances) are studied. These final states are expected to have small backgrounds and are thereby ideal for new physics searches. Implications of the analyses of these final states on Gauge Mediated Supersymmetry Breaking models are discussed for integrated luminosities of 2 and 30 1/fb. This study demonstrates that a large class of supersymmetry models can…
We study the observability for a Standard Model-like Higgs boson at an upgraded Tevatron via the modes $p \bar p \to gg \to h \to \ww \to \ljj$ and $\ll$. We find that with c. m. energy of 2 TeV and an integrated luminosity of 30 fb$^{-1}$ the signal may be observable for the mass range of $135 {\gev} \lsim \mh \lsim 180$ GeV at a $3-5σ$ statistical level. We conclude that the upgraded Tevatron may have the potential to detect a SM-like Higgs boson in the mass range from the LEP2 reach to 180 GeV.
We study the inclusive hadrodroduction of D^0, D^+, D^{*+}, and D_s^+ mesons at next-to-leading order in the parton model of quantum chromodynamics endowed with universal non-perturbative fragmentation functions (FFs) fitted to e^+e^- annihilation data from CERN LEP1. Working in the general-mass variable-flavor-number scheme, we resum the large logarithms through the evolution of the FFs and, at the same time, retain the full dependence on the charm-quark mass without additional theoretical assumptions. In this way, the cross section distributions in transverse momentum recently measured by th…
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…
In this paper, we study the observability of an invisible Higgs boson at Fermilab Tevatron and CERN LHC through the production channel $ q \bar{q} \to Z H \to \ell^+\ell^-+ \ptmiss $, where $\ptmiss$ is reconstructed from the $\ell^+\ell^-$ with $\ell=e$ or $μ$. A new strategy is proposed to eliminate the largest irreducible background, namely $ q \bar{q} \to Z(\to \ell^+\ell^-) Z(\to ν\barν)$. This strategy utilizes the precise measurements of $ q \bar{q} \to Z(\to \ell^+\ell^-) Z(\to \ell^+\ell^-)$. For $m_H=120$ GeV and with luminosity $30 fb^{-1}$ at Tevatron, a $5σ$ observation of the inv…
This article presents recent results of searches for physics beyond the Standard Model using the CDF and the D$\not$O detector at the Fermilab Tevatron Collider. All results shown correspond to analysis performed using the past 1992-1996 Fermilab Tevatron run I data (roughly $100$ $pb^{-1}$ per each experiment). In particular we describe recent Tevatron searches for scalar top in the $b+\ell+$missing-$E_{T}$ channel, for squark and gluinos using like-sign dileptons (LS), for large extra space-time dimensions and the search for leptoquarks and technicolor in the missing-$E_{T}$+heavy flavour je…
Selected recent quantum chromodynamics (QCD) measurements are reviewed for Fermilab Run II Tevatron proton-antiproton collisions studied by the Collider Detector at Fermilab (CDF) and DZero Collaborations at a centre-of-mass energy of sqrt{s}=1.96 TeV. Tantamount to Rutherford scattering studies at the TeV scale, inclusive jet and dijet production cross-section measurements are used to seek and constrain new particle physics phenomena, test perturbative QCD calculations, inform parton distribution function (PDF) determinations, and extract a precise value of the strong coupling constant, alpha…
The reach of the Fermilab Tevatron for supersymmetric matter has been calculated in the framework of the minimal supergravity model in the clean trilepton channel. Previous analyses of this channel were restricted to scalar masses m_0<= 1 TeV. We extend the analysis to large values of scalar masses m_0\sim 3.5 TeV. This includes the compelling hyperbolic branch/focus point (HB/FP) region, where the superpotential μparameter becomes small. In this region, assuming a 5σ(3σ) signal with 10 (25) fb^{-1} of integrated luminosity, the Tevatron reach in the trilepton channel extends up to m_{1/2}\sim…
We present results on hard diffraction obtained by the CDF Collaboration in Run II proton-antiproton collisions at the Fermilab Tevatron. Run I CDF results on hard diffraction are also reviewed.
