September 10, 2008

Speaker: Prof. Andrea Lommen, Franklin and Marshall College

Title: "Gravitational Wave Burst Detection Using Pulsars"

Abstract:

At the time of this talk, pulsar timing for gravitational wave detection will be in the midst of becoming an internationally coordinated effort. I will review the idea of using pulsars to detect a very low-frequency stochastic background of gravitational waves, and discuss current limits that pulsar timing places on the energy density of gravitational waves and what those limits correspond to in terms of cosmological models, most notably the merger rate of super-massive black holes in the early universe. I have become interested in the possibility of taking these ideas farther and using pulsar timing to detect bursts of gravitational radiation from a number of different possible sources, which I will describe.

September 24, 2008

Speaker: Prof. David Saltzberg, UCLA


Title: "The ANITA telescope: A one million square kilometer objective lens for high energy neutrinos"

 


Abstract:

The Antarctic Impulsive Transient Antenna (ANITA) is a long-duration balloon payload built to detect >3 EeV cosmic neutrinos. Such neutrinos may reveal the true nature of the most powerful astrophysical accelerators, and would allow us to probe the weak interaction at 150 TeV, an order of magnitude higher C.M. energy than at terrestrial machines.
A near-certain source of these neutrinos is provided by the GZK effect, in which the highest energy cosmic rays produce pions by scattering on the 3K cosmic microwave background. The ANITA instrument uses the Askaryan effect to detect neutrinos interacting in the Antarctic ice, which produce radio-cherenkov radiation. Data from our first full flight on a NASA long-duration balloon at 120,000 feet will be shown. I will also describe the improved instrument we built to fly this upcoming December. Ideas for achieving the next order of magnitude in senstivity will be discussed.

October 15, 2008

Speaker: Brendan Casey, FNAL

Title: "Quark flavor physics highlights of 2008"

 

 

Abstract:

I will give an overview of some interesting results that have recently come out of the B-factory and Tevatron programs. I will briefly cover spectroscopy where Belle, BaBar, and DØ have all claimed discovery of new states in summer 2008. Next, I will discuss searches for new sources of CP violation needed to explain the matter dominance of our universe. Here, I will focus on anomalous direct CP violation seen in charmless two-body B decay at B-factories and anomalous indirect CP violation seen in Bs mixing at the Tevatron. Finally, I will discuss searches for new charged current interactions that violate lepton universality such as a charged Higgs where information is now available from top, bottom, charm, and strange quark decay.

October 22, 2008

Speakers: Bence Kocsis, Princeton University and Ryan O'Leary, CFA - Harvard University

Title: "Gravitational waves from scattering of stellar-mass black holes in galactic nuclei"

 

Abstract:

We will discuss a new and interesting source of gravitational waves for ground-based observatories such as LIGO. In the nuclei of most galaxies, stellar mass black holes segregate from the stars and form a steep density cusp around the supermassive black hole in the center.

During two-body encounters between the BHs, occasionally enough gravitational waves are emitted to form a binary, which rapidly coalesces in less than one year. The BH-BH mergers are predominately eccentric during their merger in the LIGO band. This distinguishes them from other binary inspiral events, which circularize before becoming detectable, and allows us to use future ground-based detectors to actually probe the astrophysics inside of galacticnuclei. We also show that eccentric mergers extend the observable range of LIGO to larger masses than thought possible before, even up to 700 M_sun.

October 29, 2008

Speaker: David Khatidze, Columbia University

Title:"Measurement of the electron charge asymmetry in ppbar -> W+X -> enu + X events"

 


Abstract:

We present a measurement of the electron charge asymmetry in p¯p ? W + X ? e + X events at a center of mass energy of 1.96 TeV using 0.75 fb?1 of data collected with the D0 detector at the Fermilab Tevatron Collider. The asymmetry is measured as a function of the electron transverse momentum and pseudorapidity in the interval (?3.2, 3.2) and is compared with expectations from next-to-leading order calculations in perturbative quantum chromodynamics. These measurements will allow more accurate determinations of the proton parton distribution functions.

November 12, 2008

Speaker: Prof. Omar Benhar, INFN and Department of Physics "Sapienza" Universita' di Roma, Italy


Title: "Modeling nuclear effects in neutrino scattering"

 


Abstract:

I will outline the theoretical description of nuclei based on nonrelativistic many-body theory and realistic hamiltonians, and discuss its application to the study of electron- and neutrino-nucleus scattering observables.

November 19, 2008

Speaker: Lidija Zikovic, Columbia University


Title: "Closing in on the Higgs Boson"

 


Abstract:

The Standard Model describes the unification of electromagnetic and weak interactions. It was thoroughly tested over past thirty years, and represents one of the major successes of modern physics. This theory predicted the existence and the masses of the weak bosons. The last remaining piece of the puzzle is the Higgs boson whose existence is crucial for our understanding of the origin of particle masses.

Direct searches at LEP put a lower limit on the Higgs boson mass, and together with precision measurement constrained it to ~<200 GeV. The D0 and CDF experiments at the Tevatron recently excluded a new interval in the Higgs mass. In this time when we are entering LHC era, we are coming closer to the discovery or exclusion of the SM Higgs boson.\\ I will discuss current searches for the SM Higgs boson with the D0 experiment at Tevatron, highlighting the most important techniques. I will also draw a parallel with future searches at LHC, showing what we can learn from Tevatron experience.

December 3, 2008

Speaker: Prof. Karol Lang, University of Texas

 

Title: "A search for neutrinoless double beta decay with NEMO-3 and SuperNEMO detectors"


Abstract:

The observation of neutrino oscillations has proved that neutrinos have mass.This discovery has renewed and strengthened the interest in neutrinoless double beta decay experiments which provide the only practical way to determine whether neutrinos are Majorana or Dirac particles.NEMO-3, located in the Modane Underground Laboratory in the Frejus Tunnel under the French-Italian Alps, is an ongoing experiment looking for neutrinoless double beta decays using a powerful technique for detecting a two-electron final state by employing an apparatus combining tracking, calorimetry, and the time-of-flight measurements. We will present results from NEMO-3 and will discuss the status of SuperNEMO, the next generation experiment that will exploit the same experimental technique to extend the sensitivity of the current search.