9 research outputs found

    Partially methylated domains are hypervariable in breast cancer and fuel widespread CpG island hypermethylation

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    Global loss of DNA methylation and CpG island (CGI) hypermethylation are key epigenomic aberrations in cancer. Global loss manifests itself in partially methylated domains (PMDs) which extend up to megabases. However, the distribution of PMDs within and between tumor types, and their effects on key functional genomic elements including CGIs are poorly defined. We comprehensively show that loss of methylation in PMDs occurs in a large fraction of the genome and represents the prime source of DNA methylation variation. PMDs are hypervariable in methylation level, size and distribution, and display elevated mutation rates. They impose intermediate DNA methylation levels incognizant of functional genomic elements including CGIs, underpinning a CGI methylator phenotype (CIMP). Repression effects on tumor suppressor genes are negligible as they are generally excluded from PMDs. The genomic distribution of PMDs reports tissue-of-origin and may represent tissue-specific silent regions which tolerate instability at the epigenetic, transcriptomic and genetic level

    Observation of exclusive charmonium production and gamma+gamma to mu+mu- in p+pbar collisions at sqrt{s} = 1.96 TeV

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    7 pages, 3 figures, 1 tableWe have observed the reactions p+pbar --> p+X+pbar, with X being a centrally produced J/psi, psi(2S) or chi_c0, and gamma+gamma --> mu+mu-, in proton- antiproton collisions at sqrt{s} = 1.96 TeV using the Run II Collider Detector at Fermilab. The event signature requires two oppositely charged muons, each with pseudorapidity |eta| mu+mu-. Events with a J/psi and an associated photon candidate are consistent with exclusive chi_c0 production through double pomeron exchange. The exclusive vector meson production is as expected for elastic photo- production, gamma+p --> J/psi(psi(2S)) + p, which is observed here for the first time in hadron-hadron collisions. The cross sections ds/dy(y=0) for p + pbar --> p + X + pbar with X = J/psi, psi(2S) orchi_c0 are 3.92+/-0.62 nb, 0.53+/-0.14 nb, and 75+/-14 nb respectively. The cross section for the continuum, with |eta(mu+/-)| < 0.6, M(mumu) in [3.0,4.0] GeV/c2, is [Integral ds/(dM.deta1.deta2)] = 2.7+/-0.5 pb, consistent with QED predictions. We put an upper limit on the cross section for odderon exchange in J/psi production: ds/dy(y=0) (J/psi_O/IP) < 2.3 nb at 95% C.L

    Search for new particles decaying into dijets in proton-antiproton collisions at sqrt(s) = 1.96 TeV

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    10 pages, 4 figuresWe present a search for new particles whose decays produce two jets (dijets) using proton-antiproton collision data corresponding to an integrated luminosity of 1.13 fb-1 collected with the CDF II detector. The measured dijet mass spectrum is found to be consistent with next-to-leading-order perturbative QCD predictions, and no significant evidence of new particles is found. We set upper limits at the 95% confidence level on cross sections times the branching fraction for the production of new particles decaying into dijets with both jets having a rapidity magnitude |y| < 1. These limits are used to determine the mass exclusions for the excited quark, axigluon, flavor-universal coloron, E6 diquark, color-octet technirho, W', and Z'

    Measurement of the top quark mass at CDF using the "neutrino ϕ\phi weighting" template method on a lepton plus isolated track sample

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    Submitted to Phys. Rev. DWe present a measurement of the top quark mass with t-tbar dilepton events produced in p-pbar collisions at the Fermilab Tevatron (s\sqrt{s}=1.96 TeV) and collected by the CDF II detector. A sample of 328 events with a charged electron or muon and an isolated track, corresponding to an integrated luminosity of 2.9 fb1^{-1}, are selected as t-tbar candidates. To account for the unconstrained event kinematics, we scan over the phase space for the azimuthal angles (ϕν1,ϕν2\phi_{\nu_1},\phi_{\nu_2}) of neutrinos and reconstruct the top quark mass by minimizing a χ2\chi^2 function in the t-tbar dilepton hypothesis. We assign χ2\chi^2-dependent weights to the solutions in order to build a preferred mass for each event. Preferred mass distributions (templates) are built from simulated t-tbar and background events, and parameterized in order to provide continuous probability density functions. A likelihood fit of the preferred mass distribution in data to a weighted sum of signal and background probability density functions gives a top quark mass of 165.53.3+3.4165.5^{+{3.4}}_{-{3.3}}(stat.)±3.1\pm 3.1(syst.) GeV/c2c^2

    Search for the Decays B(s)0e+μ{B^0_{(s)}\to e^+\mu^-} and B(s)0e+e{B^0_{(s)}\to e^+e^-} in CDF Run II

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    submitted to PRLWe report results from a search for the lepton flavor violating decays B(s)0e+μB^0_{(s)}\to e^+\mu^-, and the flavor-changing neutral-current decays B(s)0e+eB^0_{(s)} \to e^+ e^-. The analysis uses data corresponding to 2fb1{\rm 2 fb^{-1}} of integrated luminosity of ppˉp \bar{p} collisions at s=1.96TeV\sqrt{s}=1.96 {\rm TeV} collected with the upgraded Collider Detector (CDF II) at the Fermilab Tevatron. The observed number of B(s)0B^0_{(s)} candidates is consistent with background expectations. The resulting Bayesian upper limits on the branching ratios at 90% credibility level are B(Bs0e+μ)47.8TeV/c2\mathcal{B}(B^0_s \to e^{+}\mu^{-}) 47.8 {\rm TeV/c^2}, and MLQ(B0e+μ)>59.3TeV/c2{M_{LQ}}(B^0\to e^+ \mu^-) > 59.3 {\rm TeV/c^2}, at 90% credibility level

    Direct Measurement of the WW Production Charge Asymmetry in \ppbar Collisions at s=1.96\sqrt{s} = 1.96 TeV

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    submitted to Phys. Rev. LettWe present the first direct measurement of the WW production charge asymmetry as a function of the WW boson rapidity \yW in \ppbar collisions at s=1.96\sqrt{s} = 1.96 \TeV. We use a sample of \wenu events in data from 1 \ifb of integrated luminosity collected using the CDF II detector. In the region |\yW| < 3.0, this measurement is capable of constraining the ratio of up and down quark momentum distributions in the proton more directly than in previous measurements of the asymmetry that are a function of the charged-lepton pseudorapidity

    Measurement of Z gamma Production in pbar{p} Collisions at sqrt{s} = 1.96 TeV

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    8 pages, 3 figures, Submitted to PRDThe production rate and kinematics of photons produced in association with Z bosons are studied using 2/fb of p\bar{p} collision data collected at the Collider Detector at Fermilab. The cross section for p\bar{p} -> l^+ l^- gamma + X (where the leptons l are either muons or electrons with dilepton mass M_{ll} > 40 GeV/c^2, and where the photon has transverse energy Et_{gamma} > 7 GeV and is well separated from the leptons) is 4.6 +/- 0.2 (stat) +/- 0.3 (syst) +/- 0.3 (lum) pb, which is consistent with standard model expectations. We use the photon Et distribution from Z-gamma events where the Z has decayed to mu^+ mu^-, e^+ e^-, or nu\bar{nu} to set limits on anomalous (non-standard-model) trilinear couplings between photons and Z bosons

    Search for Anomalous Production of Events with Two Photons and Additional Energetic Objects at CDF

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    submitted to Phys. Rev. DInternational audienceWe present results of a search for anomalous production of two photons together with an electron, muon, τ\tau lepton, missing transverse energy, or jets using ppˉp\bar{p} collision data from 1.1-2.0 fb1^{-1} of integrated luminosity collected by the Collider Detector at Fermilab (CDF). The event yields and kinematic distributions are examined for signs of new physics without favoring a specific model of new physics. The results are consistent with the standard model expectations. The search employs several new analysis techniques that significantly reduce instrumental backgrounds in channels with an electron and missing transverse energy

    Search for Technicolor Particles Produced in Association with a W Boson at CDF

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    submitted to Phys. Rev. LettInternational audienceWe present a search for the technicolor particles ρT\rho_{T} and πT\pi_{T} in the process ppˉρTWπTp\bar{p} \to \rho_{T} \to W\pi_{T} at a center of mass energy of s=1.96TeV\sqrt{s}=1.96 \mathrm{TeV}. The search uses a data sample corresponding to approximately 1.9fb11.9 \mathrm{fb}^{-1} of integrated luminosity accumulated by the CDF II detector at the Fermilab Tevatron. The event signature we consider is WνW\to \ell\nu and πTbbˉ,bcˉ\pi_{T} \to b\bar{b}, b\bar{c} or buˉb\bar{u} depending on the πT\pi_{T} charge. We select events with a single high-pTp_T electron or muon, large missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with multiple bb-tagging algorithms. The observed number of events and the invariant mass distributions are consistent with the standard model background expectations, and we exclude a region at 95% confidence level in the ρT\rho_T-πT\pi_T mass plane. As a result, a large fraction of the region m(ρT)=180m(\rho_T) = 180 - 250GeV/c2250 \mathrm{GeV}/c^2 and m(πT)=95m(\pi_T) = 95 - 145GeV/c2145 \mathrm{GeV}/c^2 is excluded
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