A Randomized Phase III Trial Investigating 2 Gy TBI Vs. Flu/2 Gy TBI Conditioning for HLA-Matched Related Donor Hematopoietic Cell Transplantation (HCT): Tempo of CD3 and NK Cell Engraftment Determines Relapse and Progression Free Survival in Patients with Hematologic

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Fludarabine/2 Gy TBI is Superior to 2 Gy TBI as Conditioning for HLA-Matched Related HCT: A Phase III Randomized Trial.

AbstractThe risks and benefits of adding fludarabine to a 2-Gy total body irradiation (TBI) nonmyeloablative regimen are unknown. For this reason, we conducted a prospective randomized trial comparing 2-Gy TBI alone, or in combination with 90 mg/m2 fludarabine (FLU/TBI), before transplantation of peripheral blood stem cells from HLA-matched related donors. Eighty-five patients with hematological malignancies were randomized to be conditioned with TBI alone (n = 44) or FLU/TBI (n = 41). All patients had initial engraftment. Two graft rejections were observed, both in the TBI group. Infection rates, nonrelapse mortality, and graft-versus-host disease (GVHD) were similar between groups. Three-year overall survival was lower in the TBI group (54% versus 65%; hazard ratio [HR], .57; P = .09), with higher incidences of relapse/progression (55% versus 40%; HR, .55; P = .06), relapse-related mortality (37% versus 28%; HR, .53; P = .09), and a lower progression-free survival (36% versus 53%; HR, .56; P = .05). Median donor T cell chimerism levels were significantly lower in the TBI group at days 28 (61% versus 90%; P < .0001) and 84 (68% versus 92%; P < .0001), as was NK cell chimerism on day 28 (75% versus 96%; P = .0005). In conclusion, this randomized trial demonstrates the importance of fludarabine in augmenting the graft-versus-tumor effect by ensuring prompt and durable high-level donor engraftment early after transplantation

Measurement of the lepton charge asymmetry in W-boson decays produced in p-pbar collisions

We describe a measurement of the charge asymmetry of leptons from W boson decays in the rapidity range 0 enu, munu events from 110+/-7 pb^{-1}of data collected by the CDF detector during 1992-95. The asymmetry data constrain the ratio of d and u quark momentum distributions in the proton over the x range of 0.006 to 0.34 at Q2 \approx M_W^2. The asymmetry predictions that use parton distribution functions obtained from previously published CDF data in the central rapidity region (0.0<|y_l|<1.1) do not agree with the new data in the large rapidity region (|y_l|>1.1).Comment: 13 pages, 3 tables, 1 figur

Observation of Hadronic W Decays in t-tbar Events with the Collider Detector at Fermilab

We observe hadronic W decays in t-tbar -> W (-> l nu) + >= 4 jet events using a 109 pb-1 data sample of p-pbar collisions at sqrt{s} = 1.8 TeV collected with the Collider Detector at Fermilab (CDF). A peak in the dijet invariant mass distribution is obtained that is consistent with W decay and inconsistent with the background prediction by 3.3 standard deviations. From this peak we measure the W mass to be 77.2 +- 4.6 (stat+syst) GeV/c^2. This result demonstrates the presence of two W bosons in t-tbar candidates in the W (-> l nu) + >= 4 jet channel.Comment: 20 pages, 4 figures, submitted to PR

Search for Narrow Diphoton Resonances and for gamma-gamma+W/Z Signatures in p\bar p Collisions at sqrt(s)=1.8 TeV

We present results of searches for diphoton resonances produced both inclusively and also in association with a vector boson (W or Z) using 100 pb^{-1} of p\bar p collisions using the CDF detector. We set upper limits on the product of cross section times branching ratio for both p\bar p\to\gamma\gamma + X and p\bar p\to\gamma\gamma + W/Z. Comparing the inclusive production to the expectations from heavy sgoldstinos we derive limits on the supersymmetry-breaking scale sqrt{F} in the TeV range, depending on the sgoldstino mass and the choice of other parameters. Also, using a NLO prediction for the associated production of a Higgs boson with a W or Z boson, we set an upper limit on the branching ratio for H\to\gamma\gamma. Finally, we set a lower limit on the mass of a `bosophilic' Higgs boson (e.g. one which couples only to \gamma, W, and Z$ bosons with standard model couplings) of 82 GeV/c^2 at 95% confidence level.Comment: 30 pages, 11 figure

Search for Chargino-Neutralino Associated Production at the Fermilab Tevatron Collider

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 $e^+e^-e^\pm$, $e^+e^-\mu^\pm$, $e^\pm\mu^+\mu^-$ or $\mu^+\mu^-\mu^\pm$ events in 106 pb$^{-1}$ integrated luminosity. We present limits on the sum of the branching ratios times cross section for the four channels: \sigma_{\chione\chitwo}\cdot BR(\chione\chitwo\to 3\ell+X) 81.5 \mgev\sp and M_\chitwo > 82.2 \mgev\sp for $\tan\beta=2$, $\mu =-600$~\mgev\sp and M_\squark= M_\gluino.Comment: 9 pages and 3 figure

Measurement of Rapidity Distribution for High Mass Drell-Yan ee Pairs at CDF

We report on the first measurement of the rapidity distribution dsigma/dy over nearly the entire kinematic region of rapidity for e^+e^- pairs in the Z-boson region of 66116 GeV/c^2. The data sample consists of 108 pb^{-1} of ppbar collisions at \sqrt{s}=1.8 TeV taken by the Collider Detector at Fermilab during 1992--1995. The total cross section in the $Z$-boson region is measured to be 252 +- 11 pb. The measured total cross section and d\sigma/dy are compared with quantum chromodynamics calculations in leading and higher orders.Comment: 7 pages, 3 figures. Submitted to Physical Review Letter

Measurement of the Decay Amplitudes of B0 --> J/psi K* and B0s --> J/psi phi Decays

A full angular analysis has been performed for the pseudo-scalar to vector-vector decays, B0 --> J/psi K* and B_s --> J/psi phi, to determine the amplitudes for decays with parity-even longitudinal and transverse polarization and parity-odd transverse polarization. The measurements are based on 190 B0 candidates and 40 B_s candidates collected from a data set corresponding to 89 inverse pb of pbarp collisions at root(s) = 1.8 TeV at the Fermilab Tevatron. In both decays the decay amplitude for longitudinal polarization dominates and the parity-odd amplitude is found to be small.Comment: 7 pages, 3 figures, 1 tabl

Measurement of the Strong Coupling Constant from Inclusive Jet Production at the Tevatron pˉp\bar pp Collider

We report a measurement of the strong coupling constant, $\alpha_s(M_Z)$, extracted from inclusive jet production in $p\bar{p}$ collisions at $\sqrt{s}=$1800 GeV. The QCD prediction for the evolution of $\alpha_s$ 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 $\alpha_s$ at the mass of the $Z^0$ boson averaged over the range 40<$E_T$<250 GeV is found to be $\alpha_s(M_{Z})= 0.1178 \pm 0.0001{(\rm stat)}^{+0.0081}_{-0.0095}{\rm (exp. syst)}$. The associated theoretical uncertainties are mainly due to the choice of renormalization scale (^{+6%}_{-4%}) and input parton distribution functions (5%).Comment: 7 pages, 3 figures, using RevTeX. Submitted to Physical Review Letter

Production of Y(1S) Mesons from chib Decays in pp(bar) Collisions at sqrt(s)=1.8 TeV

We have reconstructed the radiative decays $\chi_{b}(1P) \to \Upsilon(1S) \gamma$ and $\chi_{b}(2P) \to \Upsilon(1S) \gamma$ in $p \bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV, and measured the fraction of $\Upsilon(1S)$ mesons that originate from these decays. For $\Upsilon(1S)$ mesons with $p^{\Upsilon}_{T}>8.0$ GeV/$c$, the fractions that come from $\chi_{b}(1P)$ and $\chi_{b}(2P)$ decays are $(27.1\pm6.9(stat)\pm4.4(sys))$ and $(10.5\pm4.4(stat)\pm1.4(sys))$, respectively. We have derived the fraction of directly produced $\Upsilon(1S)$ mesons to be $(50.9\pm8.2(stat)\pm9.0(sys))$.Comment: 13 Pages, 2 figure