Indiana University High Energy Physics
and Astrophysics Seminars
2002-2003 Academic Year
| Mondays, 4pm | Refreshments 3:30 pm |
| Swain West 238 | HEP Coffee Room (SW262) |
Organizers: Mike Berger and Mark Messier
Spring Semester 2003
| Jan. 13: | Results from KAMLAND |
| Steven Dazeley | |
| LSU
The Kamioka Large Anti-Neutrino Detector (KamLAND)
is the first terrestrial experiment to reach the
same sensitivity for neutrino mass and lepton flavor
violation as solar neutrino detectors. Instead of the
sun, distant Japanese nuclear reactors are used as a
neutrino source for a 1,000 ton detector located in
the Japanese Alps. The neutrino flux and energy
spectrum from the first 145 days of operation are presented.
These results significantly impact our understanding of
neutrino properties.
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| Jan. 20: | NO SEMINAR THIS WEEK |
| Martin Luther King Jr Day | |
| Jan. 27: | |
| Feb. 3: | Elementary remarks on CPT and Lorentz invariance and their breaking, and related issues |
| O. W. Greenberg | |
| U. Maryland
I will discuss the cluster of concepts associated with quantum field theory that include locality (with different meanings), clustering, the
symmetrization postulate, the spin-statistics connection, the spin-locality connection, crossing symmetry, CPT symmetry and Lorentz invariance and their breaking.
Prof. Greenberg is the author of the recent "anti-CPT theorem" (see Phys Rev Lett 89, 231602 (2002)), which has implications for theories of CPT violation in neutrino oscillations.
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| Feb. 10: | The NuTeV "Anomaly", Neutrino Mixing, and a Heavy Higgs |
| Tatsu Takeuchi | |
| Virginia Tech U.
The result of the NuTeV experiment at Fermilab disagrees with the Standard Model (SM) by 3 sigma. This is sometimes referred to as the NuTeV "anomaly" since all the other data, in particular the data from
LEP/SLD
(with the exception of the Z invisible width) agrees perfectly with the
SM.
However, the SM that the LEP/SLD data agrees with is that with a light
Higgs (~80 GeV)
which is already ruled out! I will argue that the LEP/SLD data
(including the invisible width)
and the NuTeV result can be reconciled if 1) the neutrinos mixed with a
largish mixing angle
with heavy gauge singlet states, and 2) the Higgs were actually very
heavy.
Estimations of the masses of the new heavy states and that of the Higgs
will be presented.
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| Feb. 17: | Grand Unification in Higher Dimensions |
| Yasunori Nomura | |
| Fermilab
The standard model of particle physics is an extremely successful
theory, describing almost all experimental data up to the scale of TeV. It has, however, some undesired features: we do not understand the
complicated pattern of quark and lepton quantum numbers, nor why the
light Higgs boson, which is required to break the electroweak symmetry,
is protected from potentially huge radiative corrections. There are
several ideas addressing these questions such as supersymmetry, grand
unification and extra dimensions. In this talk I will ask whether
we can construct realistic theories beyond the standard model using
these ideas, and what are experimental signatures of such theories.
I will show that we can construct two completely different classes of
theories, which are both completely realistic and free from problems
of conventional supersymmetric grand unified theories. In one theory
we obtain a precise prediction for low energy gauge couplings, which
fits data with extraordinary accuracy, and various implications on
rare processes such as proton decay and lepton flavor violation. The other theory predicts a plethora of new particles at the TeV scale,
including superpartners, GUT particles and their Kaluza-Klein towers,
which may be produced at future colliders. Both theories are formulated
in higher dimensions and related by the size of energy densities
carried by the higher dimensional spacetime.
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| Feb. 24: | Searching for Exotic Mesons in the E852 Data |
| Adam Szczepaniak | |
| Indiana U.
Using the results obtained by the BNL E852 collaboration claims have been made on the discovery of exotic meson candidates in the mass range 1.4 - 1.6 GeV. I will discuss the shortcomings of the original analysis and present new results.
|
| Mar. 3: | Supernova Neutrinos and SNEWS |
| Kate Scholberg | |
| MIT
When the core of a massive star collapses, nearly all of the binding energy of the resulting neutron star is released in the form of neutrinos of all flavors. Such an event in our galaxy would provide a tremendous amount of information about neutrinos and about the physics of stellar collapse. In addition, because the neutrinos emerge promptly from the stellar core, the observation of a burst of neutrinos can provide an early warning for astronomers of a supernova's occurrence. This talk will discuss the nature of the neutrino signal and what can be learned from it, current and future detection capabilities, and SNEWS (SuperNova Early Warning System), an international network of observatories with the goal of providing a prompt supernova alert for astronomers.
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| Mar. 10: | Review of Higgs searches within and beyond SM and MSSM models at LEP |
| Pauline Gagnon | |
| Indiana U.
Ever since the center-of-mass energy was increased in 1995 above the Z0 resonance, the four LEP experiments have renewed their effort to search for the Higgs boson. Data taking ended in the year 2000 with about 130 pb-1 of data collected per experiment above 206 GeV in e+e- collisions but the data analysis is still very active. Most recently, the wealth of theoretical models and predictions has stimulated new analyses and model interpretations which go beyond the Standard Model and Minimal Supersymmetric Standard Model. These include the searches for charged Higgs bosons, models with two Higgs field doublets (2HDM), searches for "fermiophobic" Higgs decay into two photons, invisible Higgs boson decays, decay-mode independent searches, limits on topological cross-sections, Yukawa couplings and limits on anomalous Higgs couplings. I will give a review all Higgs boson searches within and beyond SM and MSSM done by the four LEP experiments and present the LEP combined results where they exist.
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| Mar. 17: | NO SEMINAR THIS WEEK |
| Spring Break | |
| Mar. 24: | Results from RHIC |
| Fuqiang Wang | |
| Purdue U.
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| Mar. 31: | Results from CLEO: past, present and future |
| Jon Urheim | |
| U. of Minnesota
CLEO is the name for the series of detectors that have been located in at the south interaction region of the Cornell Electron Storage Ring (CESR) e+ e- collider over the past twenty years. In addition to being well known for its studies of B meson physics, CLEO has made major contributions to the physics of charmed hadrons and tau leptons during this time. In this talk I will describe some recent and ongoing work in these areas. I will also report on CLEO's prospects for the near future, as CESR is now in the process of being reconfigured to run at lower energies, mainly in the charm threshold region.
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| Apr. 7: | The WMAP Experiment |
| Greg Tucker | |
| Brown |
| Apr. 14: | Getting Ready for GlueX |
| Dan Krop | |
| Indiana U.
Work is underway at Indiana to get ready for the GlueX experiment at Jefferson Lab. GlueX will search for mesons with exotic quantum numbers which cannot be explained by a simple quark-antiquark model. The experiment is in a unique position to discover such states, due to the advantages of photoproduction for causing gluonic excitations. Hardware preparations at I.U. will be discussed, mainly covering the Barrel Calorimeter and the Hybrid Photodiodes necessary to run the Barrel Calorimeter in the high-field environment it will be in. Analysis preparations will also be discussed, with preliminary results from a partial wave analysis performed on an earlier JLab photoproduction experiment being shown.
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| Apr. 21: | |
| Apr. 24: | The Wild, Wild West Confronts Big Science: NLC and TESLA at American Universities |
| George Gollin | |
| U. of Illinois
The participation of North American university groups in research and development projects related to the design of a Linear Collider has increased by 50% in the last twelve months. Autonomous university groups joining the effort are faced with a complicated mix of technical, sociological, and governmental challenges. Some of the non-technical problems are peculiarly American in nature. I will describe recent developments in the American program and comment on subjects ranging from the R&D projects at universities to the sociology that influences the rapid transformations in the North American research landscape.
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| Apr. 28: | A Ring Around the Galaxy: Recent news from the Sloan Digital Sky Survey |
| Brian Yanny | |
| Fermilab |
| May 12: | Flavor Violation and SUSY constrained by Unification |
| Tomas Blazek | |
| Southampton We go beyond what is called Minimal Flavour Violation in the Minimal Supersymmetric Standard Model (MSSM) and study flavor changing neutral current effects in the quark sector (Bs to mu+mu-, b to s gamma) and lepton flavor violation. The analysis is based on the best fits for the MSSM constrained by a unified Pati-Salam model (hep-ph/0303192). At tan\beta fixed to 50 there are solutions which predict that the decays Bs to mu+mu- and tau to mu gamma are close to the current experimental limit. |
| May 19:
Special time: 2PM |
Testing Physics with Cryogenic Microwave Oscillators |
| Michael Tobar | |
| University of Western Australia
The conventional understanding of the Universe admits four
fundamental interactions or forces - Gravitational, Electromagnetic,
and the Strong and Weak Nuclear Forces. It is widely believed that
these four forces are really manifestations of a single underlying
and unifying interaction that can be revealed if one examines nature
with sufficiently precise measurement. Naturally it is not clear what
type of precise measurement will reveal deviations from the present
understanding. Particle accelerators directly probe nature on
short-distance and high-energy; an alternative approach is to search
for exquisitely small deviations from known physics that can be seen
on conventional energy and distance scales. Examples of such
measurements include new versions of the famous Michelson-Morley and
Kennedy-Thorndike experiments, as well as laboratory measurements of
the time independence of the Fine Structure Constant. We are
developing a new range of oscillators and clocks, when combined with
the best from across the world, offer the prospect of measurements
that may reveal this next layer of understanding. To achieve these
types of measurements, frequency standards (or oscillators) with
frequency stability in the sub-10^-15 range are necessary. This type
of performance can be achieved with state-of-the art cryogenic
microwave oscillators. New experiments are currently underway in the
laboratory, and in the future more precise measurements are proposed
in space. These experiments will be outlined along with our
participation in the Atomic Clock Ensemble in Space (ACES) mission,
due to be launched in 2006.
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