Search for Second-Generation Scalar Leptoquarks in ppˉ\bm{p \bar{p}} Collisions at s\sqrt{s}=1.96 TeV

Results on a search for pair production of second generation scalar leptoquark in $p \bar{p}$ collisions at $\sqrt{s}$=1.96 TeV are reported. The data analyzed were collected by the CDF detector during the 2002-2003 Tevatron Run II and correspond to an integrated luminosity of 198 pb$^{-1}$. Leptoquarks (LQ) are sought through their decay into (charged) leptons and quarks, with final state signatures represented by two muons and jets and one muon, large transverse missing energy and jets. We observe no evidence for $LQ$ production and derive 95% C.L. upper limits on the $LQ$ production cross sections as well as lower limits on their mass as a function of $\beta$, where $\beta$ is the branching fraction for $LQ \to \mu q$.Comment: 9 pages (3 author list) 5 figure

Measurement of the Dipion Mass Spectrum in X(3872) -> J/Psi Pi+ Pi- Decays

We measure the dipion mass spectrum in X(3872)--> J/Psi Pi+ Pi- decays using 360 pb-1 of pbar-p collisions at 1.96 TeV collected with the CDF II detector. The spectrum is fit with predictions for odd C-parity (3S1, 1P1, and 3DJ) charmonia decaying to J/Psi Pi+ Pi-, as well as even C-parity states in which the pions are from Rho0 decay. The latter case also encompasses exotic interpretations, such as a D0-D*0Bar molecule. Only the 3S1 and J/Psi Rho hypotheses are compatible with our data. Since 3S1 is untenable on other grounds, decay via J/Psi Rho is favored, which implies C=+1 for the X(3872). Models for different J/Psi-Rho angular momenta L are considered. Flexibility in the models, especially the introduction of Rho-Omega interference, enable good descriptions of our data for both L=0 and 1.Comment: 7 pages, 4 figures -- Submitted to Phys. Rev. Let

Search for New Physics in Lepton + Photon + X Events with L=305 pb-1 of ppbar Collisions at roots=1.96 TeV

We present results of a search for anomalous production of events containing a charged lepton (either electron or muon) and a photon, both with high transverse momentum, accompanied by additional signatures, X, including missing transverse energy (MET) and additional leptons and photons. We use the same kinematic selection criteria as in a previous CDF search, but with a substantially larger data set, 305 pb-1, a ppbar collision energy of 1.96 TeV, and the upgraded CDF II detector. We find 42 Lepton+Photon+MET events versus a standard model expectation of 37.3 +- 5.4 events. The level of excess observed in Run I, 16 events with an expectation of 7.6 +- 0.7 events (corresponding to a 2.7 sigma effect), is not supported by the new data. In the signature of Multi-Lepton+Photon+X we observe 31 events versus an expectation of 23.0 +- 2.7 events. In this sample we find no events with an extra photon or MET and so find no events like the one ee+gg+MET event observed in Run I.Comment: 7 pages, 3 figures, 1 table. Accepted to PR

Search for ZZ and ZW Production in ppbar Collisions at sqrt(s) = 1.96 TeV

We present a search for ZZ and ZW vector boson pair production in ppbar collisions at sqrt(s) = 1.96 TeV using the leptonic decay channels ZZ --> ll nu nu, ZZ --> l l l' l' and ZW --> l l l' nu. In a data sample corresponding to an integrated luminosity of 194 pb-1 collected with the Collider Detector at Fermilab, 3 candidate events are found with an expected background of 1.0 +/- 0.2 events. We set a 95% confidence level upper limit of 15.2 pb on the cross section for ZZ plus ZW production, compared to the standard model prediction of 5.0 +/- 0.4 pb.Comment: 7 pages, 2 figures. This version is accepted for publication by Phys. Rev. D Rapid Communication

Cognitive reserve, presynaptic proteins and dementia in the elderly

Differences in cognitive reserve may contribute to the wide range of likelihood of dementia in people with similar amounts of age-related neuropathology. The amounts and interactions of presynaptic proteins could be molecular components of cognitive reserve, contributing resistance to the expression of pathology as cognitive impairment. We carried out a prospective study with yearly assessments of N=253 participants without dementia at study entry. Six distinct presynaptic proteins, and the protein–protein interaction between synaptosomal-associated protein 25 (SNAP-25) and syntaxin, were measured in post-mortem brains. We assessed the contributions of Alzheimer's disease (AD) pathology, cerebral infarcts and presynaptic proteins to odds of dementia, level of cognitive function and cortical atrophy. Clinical dementia was present in N=97 (38.3%), a pathologic diagnosis of AD in N=142 (56.1%) and cerebral infarcts in N=77 (30.4%). After accounting for AD pathology and infarcts, greater amounts of vesicle-associated membrane protein, complexins I and II and the SNAP-25/syntaxin interaction were associated with lower odds of dementia (odds ratio=0.36–0.68, P<0.001 to P=0.03) and better cognitive function (P<0.001 to P=0.03). Greater cortical atrophy, a putative dementia biomarker, was not associated with AD pathology, but was associated with lower complexin-II (P=0.01) and lower SNAP-25/syntaxin interaction (P<0.001). In conclusion, greater amounts of specific presynaptic proteins and distinct protein–protein interactions may be structural or functional components of cognitive reserve that reduce the risk of dementia with aging

Measurement of sigma B-chi c2(chi(c2)-> J/psi gamma)/sigma B-chi c1(chi(c1)-> J/psi gamma) in p(p)over-bar collisions at root s=1.96 TeV

We measure the ratio of cross section times branching fraction, R(p)=sigma(chi c2)B(chi(c2)-> J/psi gamma)/sigma(chi c1)B(chi(c1)-> J/psi gamma), in 1.1 fb(-1) of p (p) over bar collisions at root s=1.96 TeV. This measurement covers the kinematic range p(T)(J/psi)> 4.0 GeV/c, |eta(J/psi) 1.0 GeV/c. For events due to prompt processes, we find R(p)=0.395 +/- 0.016(stat)+/- 0.015(syst). This result represents a significant improvement in precision over previous measurements of prompt chi(c1,2) hadro production

Search for Excited and Exotic Muons in the mu+gamma Decay Channel in p-pbar Collisions at sqrt{s} = 1.96 TeV

We present a search for excited and exotic muon states mu*, conducted using an integrated luminosity of 371 pb^{-1} of data collected in p-pbar collisions at sqrt{s} = 1.96 TeV at the Tevatron with the CDF II detector. We search for associated production of mu+mu* followed by the decay mu* -> mu+gamma, resulting in the mu+mu+gamma final state. We compare the data to model predictions as a function of the mass of the excited muon M(mu*), the compositeness energy scale Lambda, and the gauge coupling factor f. No signal above the standard model expectation is observed in the mu+gamma mass spectrum. In the contact interaction model, we exclude 107 < M(mu*) < 853 GeV/c^2 for Lambda = M(mu*); in the gauge-mediated model, we exclude 100 < M(mu) < 410 GeV/c^2 for f/Lambda = 0.01/GeV. These 95% confidence level exclusions extend previous limits and are the first hadron collider results on mu* production in the gauge-mediated model.Comment: Submitted to Phys. Rev. Lett., 7 pages, 4 Figure

Measurement of the B+ production cross section in pp(-) collisions at root s=1960 GeV

We present a new measurement of the B+ meson differential cross section d sigma/dp(T) at root s=1960 GeV. The data correspond to an integrated luminosity of 739 pb(-1) collected with the upgraded CDF detector (CDF II) at the Fermilab Tevatron collider. B+ candidates are reconstructed through the decay B+-\u3e J/psi K+, with J/psi -\u3emu(+)mu(-). The integrated cross section for producing B+ mesons with p(T)\u3e= 6 GeV/c and vertical bar y vertical bar \u3c= 1 is measured to be 2.78 +/- 0.24 mu b

Search for W \u27 boson decaying to electron-neutrino pairs in p(p)over-bar collisions at root s=1.96 TeV

We present the results of a search for W-\u27 boson decaying to electron-neutrino pairs in p (p) over bar collisions at a center-of-mass energy of 1.96 TeV, using a data sample corresponding to 205 pb(-1) of integrated luminosity collected by the CDF II detector at Fermilab. We observe no evidence for this decay mode and set limits on the production cross section times branching fraction, assuming the neutrinos from W-\u27 boson decays to be light. If we assume the manifest left-right symmetric model, we exclude a W-\u27 boson with mass less than 788 GeV/c(2) at the 95% confidence level

Measurement of the B+ production cross section in p-pbar collisions at sqrt(s) = 1960 GeV

We present a new measurement of the $B^+$ meson differential cross section $d\sigma/d p_T$ at $\sqrt{s}=1960$ GeV. The data correspond to an integrated luminosity of 739pb$^{-1}$ collected with the upgraded CDF detector (CDF II) at the Fermilab Tevatron collider. $B^+$ candidates are reconstructed through the decay $B^+ \to J/\psi K^+$, with $J/\psi \to \mu^+ \mu^-$. The integrated cross section for producing $B^+$ mesons with $p_T \geq 6$ GeV/c and $|y| \leq 1$ is measured to be $2.78 \pm 0.24 \mu$bComment: 28 pages, 3 tables, 10 figures Submitted to Phys. Rev.