UCL HEP Seminars 2006
: Dr Bostjan Golob (Ljubljana)
Topics in charm hadron studies at Belle
The Belle detector at the KEK-B e^+e^- B-factory proves to be an excellent experimental environment for a wide variety of measurements. Besides the study of the CP violation in the system of B mesons, various measurements of the properties of charmed hadrons are performed. A short overview of D^0 meson mixing searches, measurements of charmonium-like resonances and properties of the recently observed charm baryons will be given.
: Dr Steve Fitzgerald (Culham)
Fusion energy and nanoscale materials science
I will give a brief overview of the nuclear fusion research at UKAEA Culham, and then discuss some recent work on the modelling of materials for use in the ferocious environment of a fusion reactor.
: David and Tegid Fest
Speakers include Albrecht Wagner, George Kalmus and David Wark. Refreshments will be provided.
: Dr Cinzia DaVia (Brunel)
3D silicon sensors
The LHC upgrades will demand the innermost layers of the tracking detectors to withstand fluences of about 10^16 n/cm^2 with improved spatial and time resolutions. Forward physics trackers will also require to reduce as much as possible the insensitive area at the detector'e edge. Active edge 3D sensors, where the p and n type electrodes penetrate through the entire silicon bulk thickness, have proven to match these requirements. Results will be reported of their response to charged particles using radioactive sources and particle beams with LHC-compatible readout electronics. The 3D fast time response studied using 0.13 um readout electronics and their signal efficiency after an exposure to reactor neutrons equivalent to ~1.4x10^16 high energy protons per sq. cm. will be discussed.
: Dr Muge Unel (Oxford)
Highlights of PhyStat
The PHYSTAT05 conference held last year in Oxford concentrated on current statistical issues in analyzing data in particle physics, astrophysics and cosmology, as a continuation of the popular PHYSTAT series at CERN (2000), Fermilab (2000), Durham (2002) and Stanford (2003). In-depth discussions on topical issues were presented by leading statisticians and researchers in their relevant fields and the latest, state-of-the-art techniques and facilities were introduced and discussed. I will summarize the conference with an attempt to highlight most of the popular and important topics which are becoming more relevant as the start-up of the LHC experiments approaches.
: Dr Zornitza Daraktchieva (UCL)
Results from the MUNU experiment on neutrino-electron scattering
The MUNU detector was designed to study electron antineutrino - electron elastic scattering at low energy. The central tracking detector is a Time Projection Chamber filled with CF4 gas, surrounded by an anti-Compton detector. In this talk I will present the final analysis of the data recorded at 3 bar and 1 bar pressure. From the 3-bar data a new upper limit on the neutrino magnetic moment of 9x10^-11 at 90 % C.L. is derived. At 1-bar a Cs-137 photopeak is reconstructed by measuring both the energy and direction of the Compton electrons in the TPC.
: IoP HEPP meeting at UCL
LHC - The first year
The programme and registration details can be found here
: Are Raklev (CERN, Bergen) — E7
Search for Charged Metastable SUSY Particles at the LHC
: Dr Mark Lancaster (UCL)
Hot results from the summer conferences
: Joey Huston (MSU)
Lessons from the Tevatron and Standard Model Benchmarks for the LHC
I will discuss results and tools from the Fermilab Tevatron and theapplication of these tools towards the understanding of the Standard Model at the LHC during the early running.
: Prof. Jonathan Butterworth (UCL) — Harry Massey amphitheatre
High energy collisions and fundamental physics; or why the proton is like the tardis
: Patricia Vahle (UCL)
Preliminary Results Of An Accelerator Based Search For Muon-Neutrino Disappearance By The MINOS Experiment
: Rick Jesik (Imperial)
Beautifully Strange Physics at DZero
The Tevatron collider experiments have a proven track record for making significant B physics measurements. The hadronic environment provides for the production of B species not readily accessible to the B-factories. One of these states, the Bs meson, is of particular interest. I will report on studies of this meson by the DZero experiment using 1 fb-1 of data. Measurements of the Bs lifetime and lifetime difference, and the first direct upper and lower bounds on the Bs mixing frequency (Delta ms) will be presented. Our measurement of the CP violation parameter in B0 mixing and decay will also be shown.
: Bino Maiheu (UCL)
Hadronization at HERMES
In the HERMES experiment, situated at the HERA storage ring in Hamburg, 27.5 GeV positrons or electrons are scattered off a fixed gaseous, polarised proton target. Data taking started in 1995 and since then HERMES has produced quite some interesting results about the nucleon's internal spin structure. To disentangle the individual contributions from the different quark flavours to the total spin 1/2 of the proton, the understanding of the production of hadrons through fragmentation is very important. Hadrons in HERMES are identified using a Ring Imaging Cherenkov (RICH) detector which is capable to disentangle with high efficiency the different hadron kinds over a momentum range of 2 to 15 GeV/c. By extracting multiplicity distributions we can study the production of hadrons more closely and moreover compare to previously published results at higher energy. Quite some effort was put into obtaining model independent results using an unfolding method to correct for experimental and QED radiative smearing as well as geometrical detector acceptance and efficiency. This talk will highlight some topics of the HERMES physics program with emphasis on the extraction of multiplicity distributions.
: Erkcan Ozcan (UCL)
Radiative Penguin Decays at B Factories
For two decades, radiative penguin decays have played a central role in the search for the "new physics" of the day: top-quark mass, extended TC, anomalous trilinear gauge couplings, fouth generation of quarks and so on. Today, at the brink of the LHC experiments, many phenomenology articles on beyond-the-SM physics, and essentially almost all of the SUSY related ones, again refer to constraints from the radiative penguin decays. In the last few years, the excellent luminosity provided by the B Factories have enabled high-precision measurements of these rare decays. This talk aims to give an overview of the experimental techniques used and current limits obtained, focusing particularly on the inclusive decay b->s\gamma, the most commonly encountered member of the radiative-penguin family in the SUSY literature.
: Carlos Frenk (University of Durham)
Cosmology confronts some of the most fundamental questions in the whole of science. How and when did our universe begin? What is it made of? How did it acquire its current appearance? There has been enormous progress in the past few years towards answering these questions. For example, recent observations have established that our universe contains an unexpected mix of components that include not only ordinary atoms, but also exotic dark matter and a new form of energy called dark energy. Gigantic surveys of galaxies like one recently completed using the Anglo-Australian Telescope in Siding Spring, New South Wales, tell us how the universe is structured. Large supercomputer simulations recreate the evolution of the universe and provide the means to relate processes occuring near the beginning of the Universe with the structures seen today. A coherent picture of cosmic evolution, going back to about a micro-second after the Big Bang, is beginning to emerge. However, fundamental issues, like the nature of the dark energy, remain unresolved. These will require understanding of what went on at even earlier times.
: Ilija Bizjak (UCL)
Measurement of |Vub| at Belle
The measurement of the Cabibbo-Kobayashi-Maskawa matrix element |Vub| is an important counterpart to the measurement of the CP violation parameter sin(2 phi1) in testing the Kobayashi-Maskawa mechanism of CP violation. Recent measurements managed to obtain |Vub| with a precision that is better than 10% and have shown that the theoretical and experimental methods employed can be used to further improve the measurement. I will present the current status of inclusive and exclusive measurements of |Vub| at Belle.
: Maury Goodman (Argonne National Laboratory) — in A19
Reactor experiments for neutrino studies
In their simplest form, neutrino oscillations are described by three mixing angles and two differences of mass squared. From solar and atmospheric neutrino experiments, four of the five numbers are approximately known. The fifth value, known as theta-13, is only constrained by an upper limit on its value, which was set by the reactor neutrino experiment CHOOZ. Ideas to measure or further limit this parameter are being pursused by "off-axis" accelerator neutrino experiments, and also by improving reactor neutrino disappearance experiments. Six such reactor experiments are being pursued: Double Chooz, Braidwood, Daya Bay, KASKA, RENO and Angra. The Double Chooz experiment, in a region of France along the Belgian border, will probably be the first one in operation. The prospects and status of this experiment will be described.