The IceCube Neutrino Observatory is a 1 km^3 detector currently under construction at the South Pole. Searching for high energy neutrinos from unresolved astrophysical sources is one of the main analysis strategies used in the search for astrophysical neutrinos with the IceCube Neutrino Observatory. A hard energy spectrum of neutrinos from isotropically distributed astrophysical sources could contribute to form a detectable signal above the atmospheric neutrino background. A reliable method of estimating the energy of the neutrino-induced lepton is crucial for identifying astrophysical neutrinos. An analysis is underway using data from the 40 string configuration taken during its 2008-2009 science run.
The DEAP/CLEAN collaboration has proposed to use liquid argon and neon as targets for dark matter and solar neutrinos. I will discuss measurements of scintillation of these liquids performed at Yale, in particular focusing on the use of pulse shape discrimination to reject electronic recoil backgrounds in liquid argon. I will also discuss studies of alpha and nuclear recoil backgrounds in a prototype detector currently operating at the underground facility at SNOLAB. If time permits, I will mention simulations of a large neon detector and their implications for detecting /pp/ solar neutrinos.
Recent helioseismology results have pointed to the possible detection of high-frequency (periods of minutes to days) gravity-mode oscillation signals in the Sun. Periodic fluctuations in density, pressure and temperature (as would be caused by g-modes at the solar core) could potentially modulate the outgoing flux of solar neutrinos, through the close relationship between temperature and neutrino production. Density fluctuations could also affect the propagation of neutrinos through the sun, through the MSW effect, because periodically-shifting matter densities could temporally vary the probability for neutrino oscillations to occur. The Sudbury Neutrino Observatory was an optimal laboratory for studying time dependence in the solar neutrino flux, due to excellent background elimination and real-time signal detection. I will discuss the searches that we performed with SNO neutrino data to identify any high-frequency periodic signal in the sun, both on broad time scales, as well as those specifically relevant to recent g-mode detection claims.
I discuss a new class of event shapes for hadron colliders which are inclusive observables whose purpose is to enforce a certain number of (central) jets in the final state. The simplest case is beam thrust in Drell-Yan, pp -> X l+l-. Requiring tau_B << 1 provides an inclusive veto for central jets while allowing forward radiation. Beam thrust is one of the simplest hadronic observables measurable at a hadron collider and can provide crucial tests of our understanding of initial state radiation. I comment on the theoretical calculation of the cross section at small tau_B and present explicit results at NNLL, which represents the first NNLL resummation for a hadron collider event shape. I also discuss the generalization of beam thrust to processes with one or more jets. For a certain desired number of jets, the generalized event shape allows one to constrain additional radiation in the event and veto undesired jets.
I will discuss the physics objectives, design, commissioning, and first data from the LHCb experiment. I will also present our plans for an Upgrade.
The prospects for the future are dominated by the next generation CERN Large Hadron Collider, located near Geneva in Switzerland, which will reach collision energies up to seven times higher than the Fermilab Tevatron. In preparation for the first year-long run of the Large Hadron Collider beginning in November 2009, I will also describe the commissioning of the Transition Radiation Tracker, an important part of the giant ATLAS experiment. The Transition Radiation Tracker is essentially a camera with 350,000 channels that takes 75 nano-second long snap-shots of the trajectories of electrically charged particles. The radius-of-curvature of a charged particle's trajectory in a strong magnetic field allows determination of the particle's momentum, while the 100 times brighter signal from transition radiation allows partial discrimination of the least massive charged particle, the electron, from other more massive charged particles.
Electroweak physics at Fermilab is entering an era of new precision. With
benchmark analyses completed, we are investigating new approaches to get the
most out of our expanding data samples. I will present a new method for
measuring the ratio of W and Z production at the Tevatron's center-of-mass
energy of 1.96 TeV. This measurement can be used to extract the indirect width
of the W boson and, therefore, the CKM matrix elements. For this analysis, a
combined sample of W and Z boson candidates is selected by requiring at least
one charged lepton and low net hadronic activity. The Missing Transverse Energy spectrum of the events is used to infer the relative rate of W and Z bosons. I
will show a preliminary measurement of this ratio using data collected with the CDF detector, and discuss future prospects.
The accelerating field inside photoinjectors is required to be stable in phase
to less than one degree. Field-symmetry considerations as well as difficulties
in routing channels for cooling water put the mounting of a field probe into
question. An alternative is to deduce the field from the incident and reflected
wave from the resonator, which demands for a precise calibration of the
channels. In this presentation, basic resonator theory is illuminated in order
to deduce a method for an automated determination of these parameters, which
also provides detailed information about the coupling (beta) and nonlinear
properties of the sensors. The procedure, based on the investigation of resonant
circles has been successfully tested at the electron guns at FLASH and PITZ. It
is currently being implemented into FPGA-based controller of the FLASH electron
gun.
The latest results on the measurement of the Bs-Bsbar oscillation frequency using 1 fb-1 of data from ppbar collisions with the CDF II detector at the Fermilab Tevatron are reported. The probability as a function of proper decay time that the Bs decays with the same, or opposite, flavor as its flavor at production, which is determined using opposite-side and same-side flavour identification methods, is measured. A signal consistent with Bs-Bsbar oscillations is found.
