Bone turnover markers are correlated with total skeletal uptake of 99mTc-methylene diphosphonate (99mTc-MDP)

ABSTRACT: BACKGROUND: Skeletal uptake of 99mTc labelled methylene diphosphonate (99mTc-MDP) is used for producing images of pathological bone uptake due to its incorporation to the sites of active bone turnover. This study was done to validate bone turnover markers using total skeletal uptake (TSU) of 99mTc-MDP. METHODS: 22 postmenopausal women (52-80 years) volunteered to participate. Scintigraphy was performed by injecting 520 MBq of 99mTc-MDP and taking whole body images after 3 minutes, and 5 hours. TSU was calculated from these two images by taking into account the urinary loss and soft tissue uptake. Bone turnover markers used were bone specific alkaline phosphatase (S-Bone ALP), three different assays for serum osteocalcin (OC), tartrate resistant acid phosphatase 5b (S-TRACP5b), serum C-terminal cross-linked telopeptides of type I collagen (S-CTX-I) and three assays for urinary osteocalcin (U-OC). RESULTS: The median TSU of 99mTc-MDP was 23% of the administered activity. All bone turnover markers were significantly correlated with TSU with r-values from 0.52 (p = 0.013) to 0.90 (p < 0.001). The two resorption markers had numerically higher correlations (S-TRACP5b r = 0.90, S-CTX-I r = 0.80) than the formation markers (S-Total OC r = 0.72, S-Bone ALP r = 0.66), but the difference was not statistically significant. TSU did not correlate with age, weight, body mass index or bone mineral density. CONCLUSION: In conclusion, bone turnover markers are strongly correlated with total skeletal uptake of 99mTc-MDP. There were no significant differences in correlations for bone formation and resorption markers. This should be due to the coupling between formation and resorption

Search for B0→π0π0B^{0}\to \pi^{0}\pi^{0} Decay

We have searched for the charmless hadronic decay of B0 mesons into two neutral pions. Using 9.13fb^-1 taken at the Upsilon(4S) with the CLEO detector, we obtain an improved upper limit for the branching fraction BR(B0-->pi0pi0) < 5.7*10^-6 at the 90% confidence level.Comment: pages postscript, also available through http://w4.lns.cornell.edu/public/CLN

A search for charged massive long-lived particles

We report on a search for charged massive long-lived particles (CMLLPs), based on 5.2 fb$^{-1}$ of integrated luminosity collected with the D0 detector at the Fermilab Tevatron $p\bar{p}$ collider. We search for events in which one or more particles are reconstructed as muons but have speed and ionization energy loss $(dE/dx)$ inconsistent with muons produced in beam collisions. CMLLPs are predicted in several theories of physics beyond the standard model. We exclude pair-produced long-lived gaugino-like charginos below 267 GeV and higgsino-like charginos below 217 GeV at 95% C.L., as well as long-lived scalar top quarks with mass below 285 GeV.Comment: submitted to Phys. Rev. Letter

Search for Zgamma events with large missing transverse energy in ppbar collisions at sqrt(s)=1.96 TeV

We present the first search for supersymmetry (SUSY) in Zgamma final states with large missing transverse energy using data corresponding to an integrated luminosity of 6.2 fb-1 collected with the D0 experiment in ppbar collisions at sqrt(s)=1.96 TeV. This signature is predicted in gauge-mediated SUSY-breaking models, where the lightest neutralino is the next-to-lightest supersymmetric particle (NLSP) and is produced in pairs, possibly through decay from heavier supersymmetric particles. The NLSP can decay either to a Z boson or a photon and an associated gravitino that escapes detection. We exclude this model at the 95% C.L. for SUSY breaking scales of Lambda < 87 TeV, corresponding to neutralino masses of < 151 GeV.Comment: submitted to Phys. Rev. Let

Search for WHWH associated production in ppˉp \bar{p} collisions at s=1.96 TeV\sqrt{s}=1.96\,{\rm TeV}

This report describes a search for associated production of $W$ and Higgs bosons based on data corresponding to an integrated luminosity of $\cal{L}$$\approx 5.3 \rm fb^{-1}$ collected with the D0 detector at the Fermilab Tevatron $p\bar{p}$ Collider. Events containing a $W\rightarrow \ell \nu$ candidate (with $\ell$ corresponding to $e$ or $\mu$) are selected in association with two or three reconstructed jets. One or two of the jets are required to be consistent with having evolved from a $b$ quark. A multivariate discriminant technique is used to improve the separation of signal and backgrounds. Expected and observed upper limits are obtained for the product of the $WH$ production cross section and branching ratios and reported in terms of ratios relative to the prediction of the standard model as a function of the mass of the Higgs boson ($M_{H}$). The observed and expected 95% C.L. upper limits obtained for an assumed $M_{H}=115 \rm GeV$ are, respectively, factors of 4.5 and 4.8 larger than the value predicted by the standard model.Comment: 25 pages, 14 figure

Measurements of single top quark production cross sections and |Vtb| in ppbar collisions at sqrt{s}=1.96 TeV

We present measurements of production cross sections of single top quarks in \ppbar collisions at $\sqrt{s}=1.96\;\rm TeV$ in a data sample corresponding to an integrated luminosity of $5.4\;\rm fb^{-1}$ collected by the D0 detector at the Fermilab Tevatron Collider. We select events with an isolated electron or muon, an imbalance in transverse energy, and two, three, or four jets, with one or two of them containing a bottom hadron. We obtain an inclusive cross section of \sigma({\ppbar}{\rargap}tb+X, tqb+X) = 3.43\pm^{0.73}_{0.74}\;\rm pb and use it to extract the CKM matrix element $0.79 < |V_{tb}| \leq 1$ at the 95% C.L. We also measure \sigma({\ppbar}{\rargap}tb+X) = 0.68\pm^{0.38}_{0.35}\;\rm pb and \sigma({\ppbar}{\rargap}tqb+X) = 2.86\pm^{0.69}_{0.63}\;\rm pb when assuming, respectively, $tqb$ and $tb$ production rates as predicted by the standard model.Comment: 11 pages, 8 figures, submitted to Phys. Rev.

Search for a Narrow ttbar Resonance in ppbar Collisions at sqrt{s}=1.96 TeV

We report a search for a narrow ttbar resonance that decays into a lepton+jets final state based on an integrated luminosity of 5.3/fb of proton-antiproton collisions at sqrt{s}=1.96 TeV collected by the D0 Collaboration at the Fermilab Tevatron Collider. We set upper limits on the production cross section of such a resonance multiplied by its branching fraction to ttbar which we compare to predictions for a leptophobic topcolor Z' boson. We exclude such a resonance at the 95% confidence level for masses below 835 GeV.Comment: 7 pages, 3 figures, submitted to Physical Review Letter

Zgamma production and limits on anomalous ZZgamma and Zgammagamma couplings in ppbar collisions at sqrt(s)=1.96 TeV

We present a measurement of ppbar->Zgamma->ll+gamma (l = e, mu) production with a data sample corresponding to an integrated luminosity of 6.2 fb^{-1} collected by the D0 detector at the Fermilab Tevatron ppbar Collider. The results of the electron and muon channels are combined, and we measure the total production cross section and the differential cross section dsigma/dp_T^gamma, where p_T^gamma is the momentum of the photon in the plane transverse to the beamline. The results obtained are consistent with the standard model predictions from next-to-leading order calculations. We use the transverse momentum spectrum of the photon to place limits on anomalous ZZgamma and Zgammagamma couplings

Precise measurement of the top quark mass in the dilepton channel at D0

We measure the top quark mass (mt) in ppbar collisions at a center of mass energy of 1.96 TeV using dilepton ttbar->W+bW-bbar->l+nubl-nubarbbar events, where l denotes an electron, a muon, or a tau that decays leptonically. The data correspond to an integrated luminosity of 5.4 fb-1 collected with the D0 detector at the Fermilab Tevatron Collider. We obtain mt = 174.0 +- 1.8(stat) +- 2.4(syst) GeV, which is in agreement with the current world average mt = 173.3 +- 1.1 GeV. This is currently the most precise measurement of mt in the dilepton channel.Comment: 7 pages, 4 figure

Search for first generation leptoquark pair production in the electron + missing energy + jets final state

We present a search for the pair production of first generation scalar leptoquarks (LQ) in data corresponding to an integrated luminosity of 5.4 fb$^{-1}$ collected with the D0 detector at the Fermilab Tevatron Collider in ppbar collisions at $\sqrt{s}=1.96$ TeV. In the channel $LQ \bar{LQ} \rightarrow e\nu_e qq'$, where q, q' are u or d quarks, no significant excess of data over background is observed, and we set a 95% C.L. lower limit of 326 GeV on the leptoquark mass, assuming equal probabilities of leptoquark decays to eq and $\nu_e q'$.Comment: 7 pages, 6 figures, submitted to PRD-R