Decoding in the absence of a codon by tmRNA and SmpB in the ribosome

In bacteria, ribosomes stalled at the end of truncated messages are rescued by transfer-messenger RNA (tmRNA), a bifunctional molecule that acts as both a transfer RNA (tRNA) and a messenger RNA (mRNA), and SmpB, a small protein that works in concert with tmRNA. Here, we present the crystal structure of a tmRNA fragment, SmpB and elongation factor Tu bound to the ribosome at 3.2 angstroms resolution. The structure shows how SmpB plays the role of both the anticodon loop of tRNA and portions of mRNA to facilitate decoding in the absence of an mRNA codon in the A site of the ribosome and explains why the tmRNA-SmpB system does not interfere with normal translation.

Measurement of ZZ production in leptonic final states at sqrt[s] of 1.96 TeV at CDF

In this Letter, we present a precise measurement of the total ZZ production cross section in pp collisions at sqrt[s]=1.96  TeV, using data collected with the CDF II detector corresponding to an integrated luminosity of approximately 6  fb(-1). The result is obtained by combining separate measurements in the four-charged (ℓℓℓ' ℓ') and two-charged-lepton and two-neutral-lepton (ℓℓνν) decay modes of the Z boson pair. The combined measured cross section for pp → ZZ is 1.64(-0.38)(+0.44)  pb. This is the most precise measurement of the ZZ production cross section in 1.96 TeV pp collisions to date.

Sorafenib, a multikinase inhibitor, is effective in vitro against non-Hodgkin lymphoma and synergizes with the mTOR inhibitor rapamycin

Non-Hodgkin lymphoma (NHL) represents a heterogenous group of neoplasias originating from lymphoid cells. Increased angiogenesis and expression of Vascular Endothelial Growth Factor (VEGF) and its receptors (VEGFR) have been found to be associated with NHL disease progression. Increase in VEGF and other cytokines stimulate signaling cascades, including the Ras/Raf/Mek/Erk pathway, resulting in increased proliferation and decreased apoptosis. Here, we report the in vitro antilymphoma activity of sorafenib, an inhibitor of VEGFR and Raf kinase. Sorafenib induced potent cytotoxicity in NHL cell lines and patient samples. This induction of cytotoxicity was associated with a corresponding increase in apoptotic cell death. Mechanism of action of sorafenib was investigated in follicular (DoHH2) and Burkitt lymphoma (Raji) cell lines. pStat3, pAkt, Mcl1, and Xiap were downregulated in both cell lines, whereas pErk decreased in Raji but not in DoHH2 cells following sorafenib treatment. IL6 was unable to prevent sorafenib induced repression of pStat3, pAkt, Mcl1, and Bcl-Xl. Sorafenib in combination with an mTORC1 inhibitor rapamycin demonstrated synergy in inducing cytotoxicity in NHL cells. Sorafenib/rapamycin combination resulted in downregulation of pAkt, pmTOR, p-p70S6K, p4EBP1, pGSK3β, Mcl1, and Bcl-Xl. On the basis of our results, a clinical trial is underway using sorafenib with everolimus in NHL patients.

Observation of exclusive γγ production in pp¯ collisions at √s=1.96 TeV

We have observed exclusive γγ production in proton-antiproton collisions at √s=1.96 TeV, using data from 1.11±0.07 fb(-1) integrated luminosity taken by the Run II Collider Detector at Fermilab. We selected events with two electromagnetic showers, each with transverse energy E(T)>2.5 GeV and pseudorapidity |η|<1.0, with no other particles detected in -7.4<η<+7.4. The two showers have similar E(T) and azimuthal angle separation Δφ~π; 34 events have two charged particle tracks, consistent with the QED process pp¯→p+e(+)e(-)+p¯ by two-photon exchange, while 43 events have no charged tracks. The number of these events that are exclusive π(0)π(0) is consistent with zero and is <15 at 95% C.L. The cross section for pp¯→p+γγ+p¯ with |η(γ)|<1.0 and E(T)(γ)>2.5 GeV is 2.48(-0.35)(+0.40)(stat)(-0.51)(+0.40)(syst) pb.

Measurements of the angular distributions in the decays B→K(*)μ(+)μ(-) at CDF

We report an indirect search for nonstandard model physics using the flavor-changing neutral current decays B→K(*)μ(+)μ(-). We reconstruct the decays and measure their angular distributions, as a function of q(2)=M(μμ)(2)c(2), where M(μμ) is the dimuon mass, in pp¯ collisions at √s=1.96 TeV using a data sample corresponding to an integrated luminosity of 6.8 fb(-1). The transverse polarization asymmetry A(T)(2) and the time-reversal-odd charge-and-parity asymmetry A(im) are measured for the first time, together with the K* longitudinal polarization fraction F(L) and the muon forward-backward asymmetry A(FB) for the decays B(0)→K(*0)μ(+)μ(-) and B(+)→K(*+)μ(+)μ(-). The B→K*μ(+)μ(-) forward-backward asymmetry in the most sensitive kinematic regime, 1≤q(2)<6 GeV(2)/c(2), is measured to be A(FB)=0.29(-0.23)(+0.20)(stat)±0.07(syst), the most precise result to date. No deviations from the standard model predictions are observed.

Search for a Higgs boson in the diphoton final state in pp collisions at sqrt[s]=1.96 TeV

A search for a narrow Higgs boson resonance in the diphoton mass spectrum is presented based on data corresponding to 7.0  fb{-1} of integrated luminosity from pp collisions at sqrt[s]=1.96  TeV collected by the CDF experiment. No evidence of such a resonance is observed, and upper limits are set on the cross section times branching ratio of the resonant state as a function of Higgs boson mass. The limits are interpreted in the context of the standard model and one fermiophobic benchmark model where the data exclude fermiophobic Higgs bosons with masses below 114  GeV/c{2} at a 95% Bayesian credibility level.

Measurement of the B(s)0 lifetime in fully and partially reconstructed B(s)0→D(s)(-)(ϕπ(-))X decays in p¯p collisions at √s=1.96 TeV

We present a measurement of the B(s)(0) lifetime in fully and partially reconstructed B(s)(0)→D(s)(-)(ϕπ(-))X decays in 1.3  fb(-1) collected in pp ¯ collisions at √s=1.96 TeV by the CDF II detector at the Fermilab Tevatron. We measure τ(B(s)(0))=1.518±0.041(stat)±0.027(syst)  ps. The ratio of this result and the world average B(0) lifetime yields τ(B(s)(0))/τ(B(0))=0.99±0.03, which is in agreement with recent theoretical predictions.

Measurement of polarization and search for CP violation in B(s)0→φφ decays

We present the first measurement of polarization and CP-violating asymmetries in a B(s)(0) decay into two light vector mesons, B(s)(0)→φφ, and an improved determination of its branching ratio using 295 decays reconstructed in a data sample corresponding to 2.9 fb(-1) of integrated luminosity collected by the CDF experiment at the Fermilab Tevatron collider. The fraction of longitudinal polarization is determined to be f(L)=0.348±0.041(stat)±0.021(syst), and the branching ratio B(B(s)(0)→φφ)=[2.32±0.18(stat)±0.82(syst)]×10(-5). Asymmetries of decay angle distributions sensitive to CP violation are measured to be A(u)=-0.007±0.064(stat)±0.018(syst) and A(v)=-0.120±0.064(stat)±0.016(syst).

Search for a heavy toplike quark in pp collisions at √s=1.96 TeV

We present the results of a search for pair production of a heavy toplike (t') quark decaying to Wq final states using data corresponding to an integrated luminosity of 5.6 fb(-1) collected by the CDF II detector in pp collisions at √s=1.96 TeV. We perform parallel searches for t'→Wb and t'→Wq (where q is a generic down-type quark) in events containing a lepton and four or more jets. By performing a fit to the two-dimensional distribution of total transverse energy versus reconstructed t' quark mass, we set upper limits on the t't' production cross section and exclude a standard model fourth-generation t' quark decaying to Wb (Wq) with mass below 358 (340) GeV/c(2) at 95% C.L.

Top-quark mass measurement using events with missing transverse energy and jets at CDF

We present a measurement of the top-quark mass using a sample of t ̄t events in 5.7 fb(-1) of integrated luminosity from p ̄p collisions at the Fermilab Tevatron with √s=1.96 TeV and collected by the CDF II Detector. We select events having large missing transverse energy, and four, five, or six jets with at least one jet tagged as coming from a b quark, and reject events with identified charged leptons. This analysis considers events from the semileptonic t ̄t decay channel, including events that contain tau leptons. The measurement is based on a multidimensional template method. We fit the data to signal templates of varying top-quark masses and background templates, and measure a top-quark mass of M(top)=172.32±2.4(stat)±1.0(syst)  GeV/c(2).

Observation of the baryonic flavor-changing neutral current decay Λb(0)→Λμ+μ-

We report the first observation of the baryonic flavor-changing neutral current decay Λ(b)(0)→Λμ(+)μ(-) with 24 signal events and a statistical significance of 5.8 Gaussian standard deviations. This measurement uses a pp collisions data sample corresponding to 6.8 fb(-1) at √s = 1.96 TeV collected by the CDF II detector at the Tevatron collider. The total and differential branching ratios for Λ(b)(0)→Λμ(+)μ(-) are measured. We find B(Λ(b)(0)→Λμ(+)μ(-))=[1.73 ± 0.42(stat) ± (syst)] × 10(-6). We also report the first measurement of the differential branching ratio of B(s)(0)→ϕμ(+)μ(-), using 49 signal events. In addition, we report branching ratios for B(+)→K(+)μ(+)μ(-), B(0)→K(0)μ(+)μ(-), and B→K(*)(892)μ(+)μ(-) decays.

Search for New T' particles in final states with large jet multiplicities and missing transverse energy in p p collisions at sqrt[s] = 1.96 TeV

We present a search for a new particle T' decaying to a top quark via T' → t + X, where X goes undetected. We use a data sample corresponding to 5.7 fb(-1) of integrated luminosity of p p collisions with sqrt[s] = 1.96 TeV, collected at Fermilab Tevatron by the CDF II detector. Our search for pair production of T' is focused on the hadronic decay channel, pp → T'T' → tt + XX → bqq b qq + XX. We interpret our results in terms of a model where T' is an exotic fourth generation quark and X is a dark matter particle. The data are consistent with standard model expectations. We set a limit on the generic production of T'T' → tt + XX, excluding the fourth generation exotic quarks T' at 95% confidence level up to m(T') = 400 GeV/c(2) for m(X) ≤ 70 GeV/c(2).

Search for B(s)(0) → μ+ μ- and B(0) → μ+ μ- decays with CDF II

A search has been performed for B(s)(0) → μ+ μ- and B(0) → μ+ μ- decays using 7 fb(-1) of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron collider. The observed number of B(0) candidates is consistent with background-only expectations and yields an upper limit on the branching fraction of B(B(0) → μ+ μ-) < 6.0 × 10(-9) at 95% confidence level. We observe an excess of B(s)(0) candidates. The probability that the background processes alone could produce such an excess or larger is 0.27%. The probability that the combination of background and the expected standard model rate of B(s)(0) → μ+ μ- could produce such an excess or larger is 1.9%. These data are used to determine B(B(s)(0)→ μ+ μ-) = (1.8(-0.9) (+1.1)) × 10(-8) and provide an upper limit of B(B(s)(0) → μ+ μ-) < 4.0 × 10(-8) at 95% confidence level.

Search for new physics in high pT like-sign dilepton events at CDF II

We present a search for new physics in events with two high pT leptons of the same electric charge, using data with an integrated luminosity of 6.1 fb(-1). The observed data are consistent with standard model predictions. We set 95% C.L. lower limits on the mass of doubly charged scalars decaying to like-sign dileptons, m(H±±) > 190-245 GeV/c(2), assuming 100% BR to ee, μμ or eμ.

Nanocrystalline hydroxyapatite and zinc-doped hydroxyapatite as carrier material for controlled delivery of ciprofloxacin

In bone disorders infections are common. The concentration of majority of antibiotics is very low in the bone tissue. A high local dose can be obtained from the ciprofloxacin-loaded hydroxyapatite nanoparticles. The present study is aimed at developing the use of hydroxyapatite and zinc-doped hydroxyapatite nanoparticles as a carrier for ciprofloxacin drug delivery system. The ciprofloxacin-loaded hydroxyapatite and zinc-doped hydroxyapatite have a good antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus. Hydroxyapatite and zinc-doped hydroxyapatite were prepared and characterized using X-ray diffraction, Transmission electron microscopy and inductively coupled plasma optical emission spectrometry. They were loaded with ciprofloxacin using optimized drug loading parameters. Drug loading, in vitro drug release and antimicrobial activity were analyzed. The influence of zinc on the controlled release of ciprofloxacin was analyzed. The results show that the presence of zinc increases the drug release percentage and that the drug was released in a controlled manner.

Measurement of the cross section for prompt isolated diphoton production in pp collisions at square root(s) = 1.96 TeV

This Letter reports a measurement of the cross section of prompt isolated photon pair production in pp collisions at a total energy square root(s)=1.96  TeV using data of 5.36  fb(-1) integrated luminosity collected with the CDF II detector at the Fermilab Tevatron. The measured cross section, differential in basic kinematic variables, is compared with three perturbative QCD predictions, a leading order parton shower calculation and two next-to-leading order calculations. The next-to-leading order calculations reproduce most aspects of the data. By including photon radiation from quarks before and after hard scattering, the parton shower prediction becomes competitive with the next-to-leading order predictions.

Observation of the Ξ(b)(0) baryon

The observation of the bottom, strange baryon Ξ(b)(0) through the decay chain Ξ(b)(0)→Ξ(c)(+)π-, where ΞΞ(c)(+)→Ξ- π+ π+, Ξ-→Λπ-, and Λ→pπ-, is reported by using data corresponding to an integrated luminosity of 4.2  fb(-1) from pp collisions at square root(s)=1.96  TeV recorded with the Collider Detector at Fermilab. A signal of 25.3(-5.4)(+5.6) candidates is observed whose probability of arising from a background fluctuation is 3.6×10(-12), corresponding to 6.8 gaussian standard deviations. The Ξ(b)(0) mass is measured to be 5787.8±5.0(stat)±1.3(syst)  MeV/c2. In addition, the Ξ(b)- baryon is observed through the process Ξ(b)-→Ξ(c)(0)π-, where Ξ(c)(0)→Ξ- π+, Ξ-→Λπ-, and Λ→pπ-.

Variations in expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in nasal mucosa of aspirin-sensitive versus aspirin-tolerant patients with nasal polyposis

BACKGROUND

Matrix metalloproteinases (MMPs) are key enzymes responsible for extracellular matrix degradation contributing to the progressive histological changes seen in lower airway disease, including asthma. MMP-9 and TIMP-1 have also shown some role in the pathogenesis of chronic rhinosinusitis (CRS) and nasal polyposis (NP).

OBJECTIVE

We aim to determine variability in expression of MMP-9 and its inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), in sinus tissue from distinct patient populations presenting with nasal polyposis.

METHODS

The expression of MMP-9 and TIMP-1 was investigated in nasal polyp tissue from 6 aspirin-sensitive (AS) and 6 aspirin-tolerant (AT) patients undergoing endoscopic sinus surgery for chronic rhinosinusitis with nasal polyposis (CRSwNP). Sinus mucosa from 6 patients with chronic rhinosinusitis without nasal polyposis (CRSsNP) was used as control. The MMP-9 and TIMP-1 expression was measured using immunofluorescence technique and graded using manual and computerized methods.

RESULTS

Expression of TIMP-1 was significantly reduced in the AS group when compared with both the AT and CRSsNP (control) groups (P < .001). The MMP-9/TIMP-1 ratio was significantly increased in the AS group when compared with other patient groups (P < .001). The MMP- 9 expression was similar between study and control groups.

CONCLUSION

These results support the importance of MMP-9 and TIMP-1 expression in nasal polyp formation. The decreased expression of TIMP-1 in AS patients may promote the effects of MMP-9 expression and thus contribute to tissue remodeling and inflammatory changes. This finding may lead to further understanding of disease severity and resistance to treatment in this group of patients, as well as the pathogenesis of nasal polyps.

Search for new dielectron resonances and Randall-Sundrum gravitons at the collider detector at Fermilab

A search for new dielectron-mass resonances using data recorded by the CDF II detector and corresponding to an integrated luminosity of 5.7  fb(-1) is presented. No significant excess over the expected standard model prediction is observed. In this data set, an event with the highest dielectron mass ever observed (960  GeV/c(2)) was recorded. The results are interpreted in the Randall-Sundrum (RS) model. Combined with the 5.4  fb(-1) diphoton analysis, the RS-graviton lower-mass limit for the coupling k/M¯(Pl)=0.1 is 1058  GeV/c(2), making it the strongest limit to date.

Limits on anomalous trilinear gauge couplings in Zγ events from pp¯ collisions at √s=1.96 TeV

Using Zγ candidate events collected by the CDF detector at the Tevatron Collider, we search for potential anomalous (non-standard-model) couplings between the Z boson and the photon. Zγ couplings vanish at tree level and are heavily suppressed at higher orders; hence any evidence of couplings indicates new physics. Measurements are performed using data corresponding to an integrated luminosity of 4.9  fb(-1) in the Z→νν¯ decay channel and 5.1  fb(-1) in the Z→l(+)l(-) (l=μ, e) decay channels. The combination of these measurements provides the most stringent limits to date on Zγ trilinear gauge couplings. Using an energy scale of Λ=1.5  TeV to allow for a direct comparison with previous measurements, we find limits on the CP-conserving parameters that describe Zγ couplings to be |h(3)(γ,Z)|<0.022 and |h(4)(γ,Z)|<0.0009. These results are consistent with standard model predictions.

Investigations of interference between electromagnetic transponders and wireless MOSFET dosimeters: a phantom study

PURPOSE

To evaluate both the Calypso Systems' (Calypso Medical Technologies, Inc., Seattle, WA) localization accuracy in the presence of wireless metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters of dose verification system (DVS, Sicel Technologies, Inc., Morrisville, NC) and the dosimeters' reading accuracy in the presence of wireless electromagnetic transponders inside a phantom.

METHODS

A custom-made, solid-water phantom was fabricated with space for transponders and dosimeters. Two inserts were machined with positioning grooves precisely matching the dimensions of the transponders and dosimeters and were arranged in orthogonal and parallel orientations, respectively. To test the transponder localization accuracy with/without presence of dosimeters (hypothesis 1), multivariate analyses were performed on transponder-derived localization data with and without dosimeters at each preset distance to detect statistically significant localization differences between the control and test sets. To test dosimeter dose-reading accuracy with/without presence of transponders (hypothesis 2), an approach of alternating the transponder presence in seven identical fraction dose (100 cGy) deliveries and measurements was implemented. Two-way analysis of variance was performed to examine statistically significant dose-reading differences between the two groups and the different fractions. A relative-dose analysis method was also used to evaluate transponder impact on dose-reading accuracy after dose-fading effect was removed by a second-order polynomial fit.

RESULTS

Multivariate analysis indicated that hypothesis 1 was false; there was a statistically significant difference between the localization data from the control and test sets. However, the upper and lower bounds of the 95% confidence intervals of the localized positional differences between the control and test sets were less than 0.1 mm, which was significantly smaller than the minimum clinical localization resolution of 0.5 mm. For hypothesis 2, analysis of variance indicated that there was no statistically significant difference between the dosimeter readings with and without the presence of transponders. Both orthogonal and parallel configurations had difference of polynomial-fit dose to measured dose values within 1.75%.

CONCLUSIONS

The phantom study indicated that the Calypso System's localization accuracy was not affected clinically due to the presence of DVS wireless MOSFET dosimeters and the dosimeter-measured doses were not affected by the presence of transponders. Thus, the same patients could be implanted with both transponders and dosimeters to benefit from improved accuracy of radiotherapy treatments offered by conjunctional use of the two systems.

First search for multijet resonances in sqrt(s) = 1.96 TeV pp collisions

We present the first model independent search for three-jet hadronic resonances within multijet events in sqrt(s) = 1.96  TeV pp collisions at the Fermilab Tevatron using the CDF II detector. Pair production of supersymmetric gluinos and squarks with hadronic R-parity violating decays is employed as an example of a new physics benchmark for this signature. Selection criteria based on the kinematic properties of an ensemble of jet combinations within each event help to extract signal from copious QCD background. No significant excess outside the top quark mass window is observed in data with an integrated luminosity of 3.2  fb(-1). We place 95% confidence level limits on the production cross section σ(pp → XX')×BR(gg → 3  jet + 3  jet) where X, X' = g, q, or q, with q, q → g + jet, as a function of gluino mass, in the range of 77  GeV/c2 to 240  GeV/c2.

Search for a very light CP-odd Higgs boson in top quark decays from pp collisions at sqrt(s)]=1.96 TeV

We present the results of a search for a very light CP-odd Higgs boson a(1)(0) originating from top quark decays t → H(±)b → W(±(*)) a(1)(0)b, and subsequently decaying into τ+ τ-. Using a data sample corresponding to an integrated luminosity of 2.7  fb(-1) collected by the CDF II detector in pp collisions at 1.96 TeV, we perform a search for events containing a lepton, three or more jets, and an additional isolated track with transverse momentum in the range 3 to 20  GeV/c. Observed events are consistent with background sources, and 95% C.L. limits are set on the branching ratio of t → H(±)b for various masses of H(±) and a(1)(0).

First measurement of the angular coefficients of Drell-Yan e(+)e(-) pairs in the Z mass region from pp¯ collisions at √s=1.96 TeV

We report on the first measurement of the angular distributions of final state electrons in pp¯ → γ*/Z → e(+)e(-) + X events produced in the Z boson mass region at √s1.96 TeV. The data sample collected by the CDF II detector for this result corresponds to 2.1  fb(-1) of integrated luminosity. The angular distributions are studied as a function of the transverse momentum of the electron-positron pair and show good agreement with the Lam-Tung relation, consistent with a spin-1 description of the gluon, and demonstrate that, at high values of the transverse momentum, Z bosons are produced via quark-antiquark annihilation and quark-gluon Compton processes.

Search for production of heavy particles decaying to top quarks and invisible particles in pp collisions at √s = 1.96 TeV

We present a search for a new particle T' decaying to top quark via T' → t + X, where X is an invisible particle. In a data sample with 4.8  fb(-1) of integrated luminosity collected by the CDF II detector at Fermilab in pp collisions with √s = 1.96  TeV, we search for pair production of T' in the lepton + jets channel, pp → tt + X + X → ℓνbqq'b + X + X. We interpret our results primarily in terms of a model where T' are exotic fourth generation quarks and X are dark matter particles. Current direct and indirect bounds on such exotic quarks restrict their masses to be between 300 and 600  GeV/c2, the dark matter particle mass being anywhere below m(T'). The data are consistent with standard model expectations, and we set 95% confidence level limits on the generic production of T'T' → tt + X + X. For the dark matter model we exclude T' at 95% confidence level up to m(T') = 360  GeV/c2 for m(X) ≤ 100  GeV/c2.

Measurements of direct CP violating asymmetries in charmless decays of strange bottom mesons and bottom baryons

We report measurements of direct CP-violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb(-1) of integrated luminosity, we obtain the first measurements of direct CP violation in bottom strange mesons, A(CP)(B(s)(0)→K(-)π(+))=+0.39±0.15(stat)±0.08(syst), and bottom baryons, A(CP)(Λ(b)(0)→pπ(-))=+0.03±0.17(stat)±0.05(syst) and A(CP)(Λ(b)(0)→pK(-))=+0.37±0.17(stat)±0.03(syst). In addition, we measure CP violation in B(0)→K(+)π(-) decays with 3.5σ significance, A(CP)(B(0)→K(+)π(-))=-0.086±0.023(stat)±0.009(syst), in agreement with the current world average. Measurements of branching fractions of B(s)(0)→K(+)K(-) and B(0)→π(+)π(-) decays are also updated.

Invariant mass distribution of jet pairs produced in association with a W boson in pp collisions at sqrt[s]=1.96 TeV

We report a study of the invariant mass distribution of jet pairs produced in association with a W boson using data collected with the CDF detector which correspond to an integrated luminosity of 4.3  fb(-1). The observed distribution has an excess in the 120-160  GeV/c(2) mass range which is not described by current theoretical predictions within the statistical and systematic uncertainties. In this Letter, we report studies of the properties of this excess.

Measurement of the forward-backward asymmetry in the B→K*μ(+)μ(-) decay and first observation of the B(s)0→ϕμ(+)μ(-) decay

We reconstruct the rare decays B(+)→K(+)μ(+0μ(-0, B90)→K*(892)(0)μ(+)μ(-), and B(s)(0)→ϕ(1020)μ(+)μ(-) in a data sample corresponding to 4.4  fb(-1) collected in pp collisions at √[s]=1.96  TeV by the CDF II detector at the Tevatron Collider. Using 121±16 B(+)→K(+)μ(+)μ(-) and 101±12 B(0)→K(*0)μ(+)μ(-) decays we report the branching ratios. In addition, we report the differential branching ratio and the muon forward-backward asymmetry in the B(+) and B(0) decay modes, and the K(*0) longitudinal polarization fraction in the B(0) decay mode with respect to the squared dimuon mass. These are consistent with the predictions, and most recent determinations from other experiments and of comparable accuracy. We also report the first observation of the B(s)(0)→ϕμ(+)μ(-) decay and measure its branching ratio BR(B(s)(0)→ϕμ(+)μ(-))=[1.44±0.33±0.46]×10(-6) using 27±6 signal events. This is currently the most rare B(s)(0) decay observed.

Measurement of the mass difference between t and t quarks

We present a direct measurement of the mass difference between t and t quarks using tt candidate events in the lepton+jets channel, collected with the CDF II detector at Fermilab's 1.96 TeV Tevatron pp Collider. We make an event by event estimate of the mass difference to construct templates for top quark pair signal events and background events. The resulting mass difference distribution of data is compared to templates of signals and background using a maximum likelihood fit. From a sample corresponding to an integrated luminosity of 5.6  fb(-1), we measure a mass difference, ΔM(top) = M(t) - M(t) = -3.3 ± 1.4(stat) ± 1.0(syst)  GeV/c2, approximately 2 standard deviations away from the CPT hypothesis of zero mass difference.

Search for heavy bottomlike quarks decaying to an electron or muon and jets in pp collisions at √s = 1.96 TeV

We report the most sensitive direct search for pair production of fourth-generation bottomlike chiral quarks (b') each decaying promptly to tW. We search for an excess of events with an electron or muon, at least five jets (one identified as due to a b or c quark), and an imbalance of transverse momentum by using data from pp collisions collected by the CDF II detector at Fermilab with an integrated luminosity of 4.8  fb(-1). We observe events consistent with background expectation, calculate upper limits on the b' pair-production cross section (σ(bb')) ≲30  fb for m(b') > 375  GeV/c2), and exclude m(b') < 372  GeV/c2 at 95% confidence level assuming a 100% branching ratio of b' to tW.

Measurement of b hadron lifetimes in exclusive decays containing a J/ψ in pp collisions at √s=1.96 TeV

We report on a measurement of b-hadron lifetimes in the fully reconstructed decay modes B(+)→J/ψK(+), B⁰→J/ψK*(892)⁰, B⁰→J/ψK(s)⁰, and Λ(b)⁰→J/ψΛ⁰ using data corresponding to an integrated luminosity of 4.3 fb⁻¹, collected by the CDF II detector at the Fermilab Tevatron. The measured lifetimes are τ(B(+))=[1.639±0.009(stat)±0.009(syst)] ps, τ(B⁰)=[1.507±0.010(stat)±0.008(syst)] ps, and τ(Λ(b)⁰)=[1.537±0.045(stat)±0.014(syst)] ps. The lifetime ratios are τ(B(+))/τ(B⁰)=[1.088±0.009(stat)±0.004(syst)] and τ(Λ(b)⁰)/τ(B⁰)=[1.020±0.030(stat)±0.008(syst)]. These are the most precise determinations of these quantities from a single experiment.

Search for high mass resonances decaying to muon pairs in √s=1.96 TeV pp collisions

We present a search for a new narrow, spin-1, high mass resonance decaying to μ(+)μ⁻+X, using a matrix-element-based likelihood and a simultaneous measurement of the resonance mass and production rate. In data with 4.6 fb⁻¹ of integrated luminosity collected by the CDF detector in pp collisions at √s=1960 GeV, the most likely signal cross section is consistent with zero at 16% confidence level. We therefore do not observe evidence for a high mass resonance and place limits on models predicting spin-1 resonances, including M>1071 GeV/c² at 95% confidence level for a Z' boson with the same couplings to fermions as the Z boson.