Session F1: Welcome Reception and Poster Session I (5:30-6:45 p.m.)

Status report of the ANTARES Neutrino Telescope

The ANTARES collaboration is building a high energy neutrino telescope in the Mediterranean sea, 40 km off La Seyne sur mer in France. The goal of the experiment is to detect high-energy cosmic neutrinos using a 3D array of 900 photomultipliers held by 12 strings. The detection principle relies on the observation, using photomultipliers, of the Cherenkov light emitted by charged leptons induced by neutrino interactions in the surrounding detector medium. Since December 2007, the ANTARES detector comprises 10 strings, a total of 750 optical detectors, connected to the shore via an undersea cable from the site at a depth of 2475m. First studies of the detector performance are detailed and preliminary results for the reconstruction of downward going cosmic ray muons as well as the observation upward going neutrino candidates are presented.   

$\nu_e$ Appearance Results from MiniBooNE

The MiniBooNE experiment at Fermi National Accelerator Laboratory recently published initial results for a search for $\nu_{e}$ appearance in a predominantly $\nu_\mu$ beam. No evidence for $\nu_e$ appearance was found at higher reconstructed neutrino energies, however, an excess was observed at low energies. An update on the $\nu_e$ appearance analysis will be given.   

Flux and Inclusive Cross Section measurement in the MINOS Near Detector.

The MINOS experiment has been recording beam neutrino interactions in the near and the far detector since March 2005 using the high-intensity NUMI beam. The near detector data sample has millions of events in the 1-50 GeV range. The shape of the inclusive cross-section as a function of energy can be extracted from the total charged current sample. We collect muon antineutrino data as well which is about 6\% of the NUMI beam. This enables us to also extract the shape of the antineutrino inclusive cross-section. Understanding the neutrino cross section in the given energy range will be important both for MINOS and for the next generation neutrino oscillation experiments (T2K, NOvA).   

Electron Neutrino Background Analysis for the MINOS Near Detector

The MINOS experiment has the potential to observe electron neutrino appearance for a set of oscillation parameters that has not been excluded by the CHOOZ experiment. However, the observation of this hypothetical signal relies on an accurate understanding of the backgrounds. In order to understand these backgrounds, an analysis of the MINOS near detector energy spectrum, which contains no oscillated signal, is utilized. The results of this analysis can then be extrapolated to the far detector to yield the background estimate. The details and results of this near detector analysis are discussed.   

Cross Section Measurement in MIPP

The Main Injector Particle Production (MIPP) Experiment (FNAL-E907) is a fixed target experiment at Fermilab. The purpose of the experiment is to measure hadronic particle production using primary 120 GeV/c protons and secondary $\pi \pm $, K$\pm $, p$\pm $ beams and target nuclei spanning the periodic table from hydrogen to uranium. Particle identification uses a Time Projection Chamber (TPC), Time of Flight (TOF), Threshold Cherenkov (Ckov), and Ring Imaging Cherenkov (RICH) detectors in a wide range of particle momenta from 5 GeV/c up to 120 GeV/c. We present the status of data analysis to determine cross sections of 58 GeV/c $\pi $/K/p beams on a thin carbon target.   

Three flavor oscillation analysis of atmospheric neutrinos in Super-Kamiokande

Recently the flavor composition of the neutrino mass states has been measured with increasing precision. However, the $\nu_{e}$ component of the third state, controlled by the mixing angle $\theta_{13}$, together with the ordering of the neutrino masses remain unknown issues. Under the normal (inverted) hierarchy there is known resonant enhancement (suppression) of the $\nu_{\mu} \rightarrow \nu_{e}$ three-flavor oscillation probability in matter for several GeV neutrinos with long baselines when $\theta_{13} >0$. Conversely, anti-neutrinos experience suppression (enhancement). Expanding the standard oscillation analysis to incorporate all active neutrino flavors, Super-Kamiokande (SK) can exploit this asymmetry to address these open questions. The SK-I and II atmospheric neutrino data has been combined and fit under a three-flavor oscillation model for both hierarchies. The results are consistent with previous analyses and zero $\theta_{13}$.   

First 5 Tower CDMS Analysis Results

The Cryogenic Dark Matter Search (CDMS) is searching for Weakly Interacting Massive Particles (WIMPs) with low-temperature detectors that have the ability to discriminate between candidate (nuclear recoil) and background (electron recoil) events with extremely high accuracy. The CDMS II experiment has completed analysis of the first data run with all 30 semiconductor detectors at the Soudan Underground Laboratory. This talk will present an overview of the experiment along with the analysis results, with a focus on the data quality studies that remove outlier events.   

The XENON100 Dark Matter Experiment: Initial Performance and Projected Sensitivity

The XENON Dark Matter Project aims at the direct detection of WIMPs (Weakly Interacting Massive Particles) with dual phase (liquid/gas) xenon time projection chambers (LXeTPCs). Following the successful performance of the XENON10 detector, which has shown in 2007 the best sensitivity to spin-independent coupling of WIMPs to matter, we have designed and completed the construction of a new TPC with an active LXe shield, containing a total of 150 kg of xenon. The detector, mounted in the same passive shield used for XENON10 at the Gran Sasso Underground Laboratory, is currently undergoing gamma calibration. Based on a similar design as XENON10, XENON100 features an increase in fiducial target mass of a factor of 10, with an overall background rate about 100 times lower. We report on the status of this development and discuss the projected sensitivity reach for dark matter detection.   

Indirect Dark Matter Searches with VERITAS

If dark matter (DM) is composed of massive, weakly-interacting particles such as the neutralino predicted by supersymmetry, pair annihilation to gamma rays or secondary particles ultimately producing a continuum spectrum of gamma rays may take place in gravitationally clustered DM. Due to their large mass-to-light ratios and the absence of conventional gamma-ray sources in their vicinity, dwarf spheroidal galaxies of the Local Group are obvious targets to search for such annihilation. We report here on gamma-ray observations taken with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) during the 2007/8 season of the dwarf galaxies Ursa Minor, Draco, and Willman I and the local group galaxy M33. We discuss the implications of these measurements for models of DM clustering and DM particle properties.   

The MICE Experiment

The International Muon Ionization Cooling Experiment (MICE) was designed to demonstrate the ionization cooling of muons for the first time, a process in which the emittance of a muon beam is reduced in a very limited time frame, compatible with the short lifetime of muons. Ionization cooling represents a fundamental step in the construction of high intensity muon accelerators, e.g. for a Neutrino Factory of Muon Collider. MICE will reduce 6D emittance of muon beams over a range of beam momenta from 140 to 240 MeV/c over a 5.5 m long cooling channel with various magnetic field configurations and measure that reduction. The muon beam will be extracted from pions produced at a dedicated beamline at the ISIS source at Rutherford Appleton Laboratory in the UK. The MICE beamline is presently in the final stages of commissioning. Measurements will begin in early 2008 with first results becoming available later during the year.   

Antiproton Experiments for Fermilab's Future

The world's most intense antiproton source is at Fermilab, and all of the antiprotons it produces are used by the Tevatron Collider. Anticipating the 2009 shutdown of the Tevatron (when the LHC is expected to surpass the Tevatron physics reach), we are preparing a proposal for a new experiment at the Fermilab antiproton source. The proposed program includes precision measurements of charmonium and the recently discovered charmonium-related states, sensitive searches for symmetry violations in the hyperon sector, and charm mixing and possible CP violation. Some supersymmetric models predict large deviations from Standard Model expectations in hyperons or charm; these can be tested in such a program.   

Prospects for a High-Sensitivity Lepton Flavor-Violating Search at Fermilab

The mu2e collaboration proposes to search for coherent, neutrinoless conversion of muons into electrons in the field of a nucleus with a sensitivity improvement of a factor of 10,000 over existing limits. Such a lepton flavor-violating reaction probes new physics at a scale unavailable by direct searches at either present or planned high energy colliders. The physics motivation for mu2e will be presented, as well as the design of the muon beamline and spectrometer. A scheme by which the experiment can be mounted in the present Fermilab accelerator complex will be described. Prospects for increased sensitivity using the Project X linac that is being proposed by Fermilab will be discussed.   

Recent Operational Experience and Future Plans for the Cornell Electron Storage Ring

Operation of the Cornell Electron Storage Ring CESR for the production of charm quark bound states from 2002 to 2008 has resulted in world-record data sets of decays of $\psi$(2s), $\psi$(3770) and D$_{\rm s}^*$ mesons. The CESR-c project required the resolution of a unique array of accelerator physics problems associated with the dynamics of counter-circulating e$^+$/e$^-$ beams in a single beam pipe and with the damping-dominated optics which were a necessary consequence of employing twelve wiggler magnets to reduce the damping time from 500~ms to 50~ms. We discuss performance limits and operational experience obtained during the six years of operation of CESR as a charm factory. Future plans for CESR, including its continued operation as a synchrotron light source, its near-term conversion to an ILC damping ring R\&D testbed, and its use as an essential component for a proposed Energy Recovery Linac will be presented as well.   

CMS Tracker Detector Performance Studies

The Compact Muon Solenoid (CMS) is scheduled to start taking data in 2008 at the CERN Large Hadron Collider (LHC), in Geneva, Switzerland. The inner tracker system of CMS is designed to provide a precise and efficient measurement of the trajectories of charged particles emerging from the LHC collisions, as well as a precise reconstruction of secondary vertices, which is crucial in the identification of a jet as arising from a b-quark. This ability makes many physics studies, from the search of the low-mass Higgs boson to studies of the top quark and physics beyond the standard model, to be very promising. The CMS Silicon Strip Tracker is by far the largest semiconductor silicon detector ever constructed. All of the systems were fully commissioned in 2007 during which five million cosmic ray tracks were recorded. We developed a tool to analyze the data taken during this time to identify noisy and dead channels based on the information provided by the Data Quality Monitoring system (DQM). The excellent performance of the tracker is seen from the small fractions of bad channels and the stability of the system when operating at different temperatures.   

Overview of recent $D^0$ mixing results from the Babar experiment

During 2007 both BaBar and Belle surprised the physics community with unexpected results in charm-mixing. Since this time there has been several confirmations of this phenomena. We will present an overview of recent results from the BaBar experiment for the $D^0$ meson oscillating into its own anti-particle, (or vice versa).   

Measurements of Partial Branching Fractions for $\bar B \to X_u \ell \bar \nu$ and Determination of $|V_{ub}|$ at BaBar

We present partial branching fractions for inclusive charmless semileptonic $B$ decays $\bar B \to X_u \ell \bar \nu$, and the determination of the CKM matrix element $|V_{ub}|$. The analysis is based on a sample of 383 million Y(4S) decays into $B \bar B$ pairs collected with the BaBar detector at the PEP-II $e^+ e^-$ storage rings. $\Upsilon(4S) \to B\bar B$ events are tagged by the full reconstruction of a hadronic decay of one of the $B$ mesons. Signal $\bar B \to X_u \ell \bar \nu$ is then identified looking at several kinematic variables. The corresponding value of $|V_{ub}|$ is extracted.   

Study of $B$ decays to two-body final states with $\eta$, $\eta'$, $\omega$, and $\pi^0$ mesons

We present preliminary measurements of the branching fractions of $B$ meson decays to charmless two-body final states with $\eta$, $\eta'$, $\omega$, and $\pi^0$ mesons. Knowledge of these decay rates constrains some of the strong-interaction corrections to CP asymmetries in decays such as $B^0 \to \eta' K^0$. The data were collected with the BABAR detector at the PEP II asymmetric collider at SLAC.   

Measurements of the Mass and Width of the $D_1(2420)$ and the $D_2^*(2460)$

The copious inclusive production of charm mesons in the BaBar detector at the PEP-II $B$-factory enables detailed investigation of the spectroscopy of charm meson states decaying to a $D^*$ and at least one pion. We will present preliminary high precision measurements of the mass and width values of the $D_1(2420)$ and the $D_2^*(2460)$, observed in the decay to $D^*\pi$.   

Improved measurement of the branching fraction, polarization, and $CP$ asymmetry in $B^+\to\rho^0\rho^+$ decays

Based on data collected at the $\Upsilon(4S)$ resonance by the Babar detector at the PEP-II asymmetric-energy $e^+ e^-$ storage rings at SLAC, we present an improved measurement of the $B^+\to\rho^0\rho^+$ branching fraction, polarization, and direct $CP$ asymmetry. These results can be used to improve the determination of the CKM unitarity angle $\alpha$.   

Measurement of the differential top cross section ($d\sigma$/$dM_{t\bar t}$) at CDF

We present a measurement of the $t\overline{t}$ differential cross section, $d\sigma/dM_{t\overline{t}}$, at $\sqrt{s}= 1.96$~TeV using approximately $1.9~fb^{-1}$ of data collected with the CDF II Detector at the Fermilab Tevatron. We select events in the $W+\geq4$~jets sample with displaced secondary vertices from jets with heavy-flavor decays. We use a regularized unfolding technique to correct the reconstructed invariant mass distribution back to the true distribution. We see no evidence of inconsistency with the standard model, with an observed p-value of 0.45.   

Search for Chargino-Neutralino Production with Trilepton Data at CDF

Chargino-neutralino production is one of the most promising SUSY signals that could be observed at the Tevatron. Cross sections of the order of 0.1 pb have not been excluded yet, under the mSUGRA scenario, and the characteristic trilepton signature is not contaminated by significant standard model backgrounds. We present a search for associated production of the lightest chargino and the next-to-lightest neutralino in multi-lepton final states using ~2.3 fb$^{-1}$ of 1.96 TeV $p-\bar{p}$ data collected by the CDF-II detector at the Fermilab Tevatron.   

Measurement of the W Boson Helicity in Top Quark Decay at D0

We report on a model-independent measurement of the helicity of W bosons produced in top quark decays based on a 1 fb$^{-1}$ sample of ttbar events in the dilepton and lepton+jets channels. In the standard model, the fraction of longitudinal (right-handed) W bosons is predicted to be 0.7 (0). The deviation from these values would be a clear sign of new physics. The measurement is based upon the angle between the momenta of the down-type fermion and the top quark in the W boson rest frame.   

Search for Flavor Changing Neutral Currents in Top Decays at CDF

We present a direct upper limit on the branching ratio of the flavor-changing top quark decay $t \to Zc$ using 1.5 pb$^{-1}$ of $p\bar{p}$ collision data. We parametrize the upper limit as a function of the Z boson's helicity to cover the full range of possible decay structures. The analysis is based on the comparison of two processes: $p\bar{p} \to t\bar{t} \to WbWb \to l \not\!\!{E_{T}} bbjj$ and $p\bar{p} \to t\bar{t} \to ZcWb \to l^+l^- cbjj$. The use of these two decay modes together allows cancellation of dominant systematic uncertainties on acceptance, efficiency, and luminosity. We validate the MC modeling of acceptance and efficiency for lepton identification over the multi-year dataset with a measurement of the ratio of the inclusive production of $W$ and $Z$ bosons. The upper limit on the $Br(t \to Zc)$ is estimated from a simultaneous fit to the $l^+l^-cbjj$ mass distribution and the number of lepton + $\not\!\!{E_{T}}$ + 4 jets events.   

Combined Upper Limit on Standard Model Higgs Boson Production at D0

A combination of several searches for Standard Model Higgs boson production at D0 is presented. The contributing processes include associated production ($WH\to l\nu bb$, $ZH\to\nu\nu bb$, $ZH\to ll bb$, and $WH\to WWW^{(*)}$) and gluon fusion ($gg\to H\to WW^ {(*)}$). Analyses are performed on data corresponding to integrated luminosities from 1~fb$^{-1}$ to 2~fb$^{-1}$.   

Search for Higgs Bosons Produced in association with W bosons at CDF

We present a search for the Higgs boson decaying to bb pairs and produced in association with a W boson in pp collisions at sqrt(s) = 1.96 TeV. We searched a dataset corresponding to an integrated luminosity of 1.9 fb-1. Our candidate events have one high-pT muon or election, missing ET, and two jets. We increased the purity of our sample by using advanced techniques to identify several categories of jets with b-quarks. We further improved our discrimination of Higgs signal from W+jet backgrounds through the use of an artificial neural network. We combined our searches in the separate tag categories and set a 95\% Confidence Level upper limit on the production cross section times branching ratio.   

Single Top Quark Production at D0 in the Muon Decay Channel using Boosted Decision Trees

Protons and antiprotons are collided at the Fermilab Tevatron at a center of mass energy of 1.96~TeV. We have performed a search for single top quark production in these collisions using a dataset of 2.2 fb$^{-1}$ collected with the D\O\ detector in the muon+jets channel. This analysis utilizes secondary-vertex tagging to identify jets originating from $b$~quarks. It probes the muon+jets decay mode, where the $W$~boson from the top quark decays into a muon and a neutrino. We present results from the application of boosted decision trees to separate the expected signals from backgrounds.   

Search for single top quark production at CDF using a multivariate likelihood method

The electroweak production of single top quarks has been sought after since the discovery of the top quark more than 10 years ago. The measurement of the cross section for single top quarks provides sensitivity to the CKM element $V_{tb}$ and is sensitive to various models of physics beyond the standard model. We present new results from the search for single top quark production using 2 fb$^{-1}$ of data accumulated with the CDF detector. We select events with one charged lepton, large missing transverse energy, and two jets, where one jet is identified as a $b$-quark jet using displaced secondary-vertex information from the CDF silicon detector at the Fermilab Tevatron. Results are given using a multivariate likelihood function, used to search for s-channel and t-channel single-top production as well as the combined process.   

Measurement of the Top Quark Mass at D0 Using the Matrix Weighting Method on Dilepton Events

We present a measurement of the top quark mass in the dilepton channel based on approximately 1 fb~$^{-1}$ of data collected by the D0 experiment during Run II of the Fermilab Tevatron collider. The kinematics of these events are not sufficiently constrained by the observed final state to reconstruct the top quark mass. We therefore compute a likelihood for the observed events to occur for a range of assumed top quark masses. For each event we choose the hypothesized top quark mass at which this likelihood is maximized as the estimator for the top quark mass. We compare the distribution of this estimator for all events to Monte Carlo predictions for different input top quark masses in a maximum likelihood fit to extract the top quark mass.   

Measurement of the top quark mass in the lepton+jets channel using quantities that are independent of the jet energy scale at CDF

We will present two techniques for measuring the top quark mass in the lepton plus jets channel using quantities independent of the jet energy scale. One technique exploits the correlation of the transverse decay length of $b$-tagged jets with the top quark mass, and the other exploits the correlation of the transverse momentum of the lepton in the same events with the top quark mass. While these results are still statistically limited, their precision will improve with added data at the Tevatron and the LHC. Further, since their correlation to more conventional top quark mass measurement techniques is small, they will help to reduce the overall uncertainty on the top mass in combination with other results.   

Measurement of the Charge Asymmetry in Top Production in Proton-Antiproton Collisions at D0

We report on the first measurement of the forward-backward asymmetry in top quark production in proton-antiproton collisions based on 0.9 fb$^{-1}$ of data. If the component of the top quark momentum along the proton direction is larger than that of antitop the asymmetry is defined as positive and negative otherwise. Top and and antitop momenta are reconstructed in lepton+jets sample using b-tagging information and kinematic constraints.   

Measurement of the top quark mass using the matrix element analysis technique in the lepton + jets channel with in situ W calibration at CDF

We present a top quark mass measurement from $p\bar p$ collisions at CDF. We use events from $p\bar p$ to $t\bar t$ in the lepton+jets channel requiring one charged lepton, high missing transverse energy and at least 4 jets, at least one of which must be identified as a $b$-jet. The top quark mass is extracted with a 2D unbinned likelihood fit using per-event probabilities calculated using leading-order signal ($t\bar t$) and background ($W$+jets) matrix elements. The probabilities are a function of both the top quark mass and the energy scale of the calorimeter jets (JES) which is measured in-situ by constraining the invariant mass of two hadronic jets to the $W$ boson mass.   

LRO, LEND and the Search for Water on the Moon

This presentation is an overview of the Lunar Emitted Neutron Detector (LEND) mission aboard the Lunar Reconnaissance Orbiter (LRO), scheduled for launch by NASA in October 2008. Instruments aboard LRO will map the lunar surface in unprecedented detail. LEND is a collimated epithermal and thermal neutron detector developed in Russia under the direction of Igor Mitrofanov and will measure the lunar neutron albedo. A decrease in epithermal neutron count rates is associated with the presence of surface and subsurface hydrogen. It is postulated that at least some of the hydrogen present in permanently shadowed regions is in the form of water ice. The Moon's spin axis is inclined at 1.5 degrees to the ecliptic plane which can result in unusual lighting conditions at the lunar poles. Data from Lunar Prospector and Clementine indicate the presence of water ice in permanently shadowed areas at low elevations of impact craters near the poles. These regions provide an environment suitable for the storage of water ice due to their relatively low constant surface and subsurface temperatures. Estimates of permanent shadow areas range from 5300 km$^{2}$ to7500 km$^{2}$ for the north pole and 3300 km$^{2}$ to 6500 km$^{2}$ for the south pole.   

Improving the Higgs Mass Resolution by Using a Neural Network to Make Jet Corrections in the ZH --$>$ l+l-bb Channel

The search for the Higgs boson is of great interest, with a variety of searches ongoing at the CDF and D0 experiments at the Tevatron at Fermilab, as well as planned searches in theupcoming LHC detectors ATLAS and CMS. At Fermilab, one primary mode for a low mass Higgs is via ZH production. In this channel, the Z boson (Z) decays into a lepton pair, and the Higgs boson (H) decays into a bottom quark and an anti-bottom quark pair. The leptons can be accurately detected and measured, whereas the quarks decay into jets, which are more difficult to measure accurately. This analysis investigates the use of the precise measurements of the leptons to improve the measurement of the individual jets, and thus the determination of the resulting Higgs mass. The method we investigate involves the use of Artificial Neural Networks. We present expected improvements in Higgs mass resolution at CDF.   

Development of Neutron Diagnostics for 1 MA Z-Pinch

The causal relationship between properties of a solid Z-pinch target is acknowledged theoretically but has been difficult to verify experimentally. We are using a unique target system, palladium metal with internally stored hydrogen or deuterium as a variably-modified target with significant diagnostic emission advantages over pure elements or near-equal mass component alloys. The neutrons from d-d interactions in the deuterium loaded samples provide a new window into the effects of instabilities and the properties of two-component plasmas. The main experimental components of this work include the construction of a unique target processing system and the development of a new Z-pinch plasma neutron diagnostic capability. The development and calibration of these neutron detectors will be presented along with preliminary data from Z-pinch experiments.   

Calibration and Installation of the UConn O-TPC at TUNL.

An Optical Readout Time Projection Chamber (O-TPC) will be used in an experiment at the HIgS facility at TUNL for studying oxygen formation during stellar helium burning. The calibration of the O-TPC was carried out at the LNS at Avery Point and subsequently the detector was transferred to the TUNL lab at Duke in August 2007. A variety of pre-amplifers and high voltage power supplies were tested and under stable conditions an energy resolution as good as 3.0{\%} was found in the charge signal. Charge and light gain curves were obtained using a 148Gd source and a 75 mm diameter PMT placed at approximately 85 cm. These determined the optimal conditions for operating the O-TPC. Under the optimized conditions a CCD camera was used to capture images of single and double tracks of alpha particles from a 148Gd source. The 3.18 MeV alpha particles yielded tracks containing only 40-50 photo electrons due to the small lens currently in use. The calibration results obtained at UConn were reproduced at the TUNL lab after the detector was installed at TUNL and it is being prepared for accepting beams from the HIgS facility.