Search for the Exotic Meson X(5568) with the Collider Detector at Fermilab

A search for the exotic meson X(5568) decaying into the B[subscript s][superscript 0]π[superscript ±] final state is performed using data corresponding to 9.6  fb[superscript -1] from pp[over ¯] collisions at sqrt[s]=1960  GeV recorded by the Collider Detector at Fermilab. No evidence for this state is found and an upper limit of 6.7% at the 95% confidence level is set on the fraction of B[subscript s][superscript 0] produced through the X(5568)→B[subscript s][superscript 0]π[superscript ±} process

Search for standard-model Z and Higgs bosons decaying into a bottom-antibottom quark pair in proton-antiproton collisions at 1.96 TeV

The Collider Detector at Fermilab collected a unique sample of jets originating from bottom-quark fragmentation (b-jets) by selecting online proton-antiproton (pp̄) collisions with a vertex displaced from the pp̄ interaction point, consistent with the decay of a bottom-quark hadron. This data set, collected at a center-of-mass energy of 1.96 TeV, and corresponding to an integrated luminosity of 5.4 fb-1, is used to measure the Z-boson production cross section times branching ratio into bb̄. The number of Z→bb̄ events is determined by fitting the dijet-mass distribution, while constraining the dominant b-jet background, originating from QCD multijet events, with data. The result, σ(pp̄→Z)×B(Z→bb̄)=1.11±0.08(stat)±0.14(syst) nb, is the most precise measurement of this process, and is consistent with the standard-model prediction. The data set is also used to search for Higgs-boson production. No significant signal is expected in our data and the first upper limit on the cross section for the inclusive pp̄→H→bb̄ process at s=1.96 TeV is set, corresponding to 33 times the expected standard-model cross section, or σ=40.6 pb, at the 95% confidence level

Search for standard-model Z and Higgs bosons decaying into a bottom-antibottom quark pair in proton-antiproton collisions at 1.96 TeV

The Collider Detector at Fermilab collected a unique sample of jets originating from bottom-quark fragmentation (b-jets) by selecting online proton-antiproton (p[¯ over p]) collisions with a vertex displaced from the p[¯ over p] interaction point, consistent with the decay of a bottom-quark hadron. This data set, collected at a center-of-mass energy of 1.96 TeV, and corresponding to an integrated luminosity of 5.4  fb[superscript -1], is used to measure the Z-boson production cross section times branching ratio into b[¯ over b]. The number of Z→b[¯ over b] events is determined by fitting the dijet-mass distribution, while constraining the dominant b-jet background, originating from QCD multijet events, with data. The result, σ(p[¯ over p]→Z)×B(Z→b[¯ over b])=1.11 ± 0.08(stat) ± 0.14(syst)  nb, is the most precise measurement of this process, and is consistent with the standard-model prediction. The data set is also used to search for Higgs-boson production. No significant signal is expected in our data and the first upper limit on the cross section for the inclusive p[¯ over p]→H→b[¯ over b] process at √s=1.96  TeV is set, corresponding to 33 times the expected standard-model cross section, or σ=40.6  pb, at the 95% confidence level.National Science Foundation (U.S.)United States. Department of EnergyAlfred P. Sloan Foundatio

Search for the Exotic Meson X(5568) with the Collider Detector at Fermilab

A search for the exotic meson X(5568) decaying into the Bs0π± final state is performed using data corresponding to 9.6 fb-1 from pp̄ collisions at s=1960 GeV recorded by the Collider Detector at Fermilab. No evidence for this state is found and an upper limit of 6.7% at the 95% confidence level is set on the fraction of Bs0 produced through the X(5568)→Bs0π± process

Tevatron Run II combination of the effective leptonic electroweak mixing angle

Drell-Yan lepton pairs produced in the process pp→â.,"+â.,"-+X through an intermediate γ∗/Z boson have an asymmetry in their angular distribution related to the spontaneous symmetry breaking of the electroweak force and the associated mixing of its neutral gauge bosons. The CDF and D0 experiments have measured the effective-leptonic electroweak mixing parameter sin2θefflept using electron and muon pairs selected from the full Tevatron proton-antiproton data sets collected in 2001-2011, corresponding to 9-10 fb-1 of integrated luminosity. The combination of these measurements yields the most precise result from hadron colliders, sin2θefflept=0.23148±0.00033. This result is consistent with, and approaches in precision, the best measurements from electron-positron colliders. The standard model inference of the on-shell electroweak mixing parameter sin2θW, or equivalently the W-boson mass MW, using the zfitter software package yields sin2θW=0.22324±0.00033 or equivalently, MW=80.367±0.017 GeV/c2

Search for B-s(0) -> mu(+) mu(-) and B-0 -> mu(+) mu(-) decays with the full CDF Run II data set (vol 87, 072003, 2013)

Erratum: Search for Bs0 →μ+μ- and B0 →μ+μ- decays with the full CDF Run II data set (Physical Review D (2013) 87 (072003

Beam Request Spin-Filtering Studies at COSY

Summary of experiment: We report on the progress of the PAX experimental program since the last PAC meeting. During two blocks of each three weeks beam development intercepted by two weeks of maintenance, systematic machine studies have been carried out. An effective procedure for setting up the machine with the low-β section and a target cell at the new PAX-IP in order to achieve high beam lifetimes has been developed. The effect of flow-limiters and one NEG-pump on the beam lifetime has been studied, as well as the effect of different beam emittances and beam intensities on the beam lifetime. Even though by increasing the beam emittance a reproducible maximum for the beam lifetime was achievable, no effect of the beam intensity was seen and therefore no clear observation of the so-called Touschek-effect was possible. Nevertheless, we learned how to gain a sufficient beam lifetime for spin-filtering studies at COSY and apply for 3 weeks of beam development followed by 4 weeks of beam time

Status Report and Beam-Time Request for COSY experiment #199 Spin–Filtering Studies at COSY

We report on the progress of the PAX experimental programme since the last PAC meeting. During summer shutdown 2009 four new quadrupole magnets and a modified vacuum system have been installed into the COSY ring to form a section with low β functions. With the successful commissioning of this low-β insertion in January 2010 it has also been discovered that intra-beam scattering effects are likely limiting the beam lifetime. In order to get these effects under control and to improve the lifetime, to commission a new detection system, and to finally perform a first series of spin–filtering measurements with transverse polarisation, we request ten weeks of beam time. Content