CLASSE: LEPP Journal Club

Skip to content

We’ve built a new site! You can make your way there by clicking here.
If you are having trouble finding what you need, please email


Fall 2003
Fri Sep 5 Duboscq, Heltsley Cornell University Highlights from the Lepton Photon Conference

Fri Sep 12 Rob Nelson Princeton University Nuclear Bunker Buster, Mini-Nukes and the Future of the U.S. Nuclear Stockpile

Fri Sep 19 Jon Rosner U Chicago, LEPP The quark model in spectroscopy POSTPONED to 10/31/03

Fri Sep 26 Dan Ralph Cornell University - LASSP What's New in Nano-physics?

Fri Oct 3 Boris Kayser Fermilab The Neutrino World: Present and Future

Thu Oct 9 Giorgio Gratta Stanford University How much does a neutrino weigh?

Fri Oct 17 Bill Louis LANL Searching for neutrino oscillations: early results from miniBoone

Fri Oct 24 Georg Hoffstaetter Cornell University The Cornell Energy Recovery Linac Project

Fri Oct 31 Jon Rosner U Chicago, LEPP The Quark Model in Spectroscopy

Fri Nov 7 Seth Digel Stanford U GLAST: Astronomy with Silicon Strips in Space

Fri Nov 14 Raimond Snellings NIKHEF Amsterdam Heavy Ion Physics at RHIC

Thu Nov 20 Michael Woods SLAC The Weak Mixing Angle from SLAC E-158

Fri Nov 21 Yibin Pan U Wisconsin Measurement of CP Violation At BaBar and Belle

Fri Nov 28 -- No seminar - Thanksgiving

WATCH FOR NEW DATE Alain Bellerive Carleton University New Results from SNO

Fri Dec 12 Ian Shipsey Purdue University Bringing Hearing to the Deaf -- a Technical and Personal Account

Fri Dec 19 --- No seminar

Fri Dec 26 --- No seminar

January - August 2004

Thu Jan 22 Robyn Madrak Fermilab Measurement of the Lambda_b Lifetime in the Decay Mode Lambda_b -> J/Psi Lambda

Fri Jan 23 --- No Journal Club - CLEO Meeting

Fri Jan 30 Tim Meyer National Research Council Science Policy: Connecting Bucks with the Cosmos

Fri Feb 6 Gabriela Gonzalez Louisiana State University Searching for Gravitational Waves with LIGO: a progress report

Fri Feb 13 Urs Langenegger University of Heidelberg Inclusive Determination of |V_ub|

Fri Feb 20 James Beatty Penn State Particle Astrophysics and the Extreme Universe

Thu Feb 26 Phil Rubin George Mason / U of Edinburgh Recent Results from NA48

Fri Feb 27 --- No Journal Club - CLEO Meeting

Fri Mar 5 David Tedeschi U of South Carolina Columbia Experimental Evidence for Pentaquark States

Fri Mar 12 Harry Nelson UCSB The Cryogenic Dark Matter Search

Fri Mar 19 Björn Lange Cornell Proposal for a precision measurement of |Vub| from inclusive B decay

Fri Mar 26 --- No Journal Club - Cornell Spring Break

Fri Apr 2 --- No Journal CLub - CLEO Meeting

Fri Apr 9 David Jaffe BNL KOPIO: An Experiment to Measure

Fri Apr 16 Kurt Gottfried Cornell Scientific Knowledge and the Bush Administration

Fri Apr 23 Fred Goldhaber Stony Brook Looking for Mr. Glueball

Fri Apr 30 John Cumalat U of Colorado Boulder Recent Charm Meson Results from the FOCUS Collaboration

Thu May 6 Klaus Peters Ruhr-Universität Bochum Dalitz Plot Analysis Techniques

Fri May 7 Mikhail Voloshin U of Minnesota D mesons and charmonium near the open charm threshold

Fri May 14 Konstantin Matchev U of Florida / Cornell Dark Matter and Physics Beyond the Standard Model at Colliders

Fri May 21 Jim Thomas LBNL On the Trail of a Strongly Interacting Plasma at RHIC

Fri June 11 Alan Schwartz U of Cincinnati New Results from the Belle Experiment:
Observation of Large CP Violation
in B->pi+pi- Decays

Fri June 25 Leslie Rosenberg LLNL The Axion Dark Matter Experiment

Fri July 2 --- no Journal Club

Fri July 9 Andy Hocker U of Rochester Top Physics Results From TeVatron Run II

Fri July 16 E. Blucher U Chicago A New Determination of |Vus| from KTeV

Thu Aug 5 Stephen Olsen U Hawaii The X(3872); charmonium or a new type of meson?

Abstracts and Transparencies

Jan 22
Robyn Madrak, Fermilab
Measurement of the Lambda_b Lifetime in the Decay Mode Lambda_b -> J/Psi Lambda

I describe a measurement of the Lambda_b lifetime in the exclusive decay mode Lambda_b -> J/Psi Lambda, with J/Psi -> mu^+ mu^- and Lambda -> p^+ pi^-. This is the first measurement of the Lambda_b lifetime in a mode where the Lambda_b is fully reconstructed, done at the CDF-II experiment at Fermilab, with 65 pb^(-1) of p pbar collision data. As a control sample, we use B^0 -> J/Psi K_s^0 with J/Psi -> mu^+ mu^- and K_s^0 -> pi^+ pi^-. The lifetime of the B^0 is well measured, and the decay mode J/Psi K_s^0 is kinematically similar to Lambda_b -> J/Psi Lambda. ppt

Jan 30
Tim Meyer, National Research Council
Connecting Bucks with the Cosmos: An Overview of Science Policy and the National Academies
The National Academy of Sciences was chartered by Congress in 1863 under President Abraham Lincoln to, "whenever called upon by any department of the government, investigate, examine, experiment, and report upon any subject of science or art." With the addition of the National Research Council by Woodrow Wilson, the Academies have become a unique advice-giving institution, providing science for policy and policy for science. In this presentation, I will describe my perspective on science policy and the federal budget process. I will also describe several exemplar projects that cover physics, astronomy, fusion, and large facility research projects. pdf

Feb 6
Gabriela Gonzalez, Louisiana State University
Searching for Gravitational Waves with LIGO: a progress report
The LIGO detectors at the Hanford and Livingston Observatories, and the GEO detector in Hannover, Germany, have been improving their performance and are getting close to achieve their designed sensitivity. The LIGO Science Collaboration has taken data with the LIGO and GEO gravitational wave detectors, and is developing the data analysis methods to look for the elusive gravitational waves. I will present some of the details of such an exciting quest, the results setting up upper limits on strength of gravitational waves using the data taken in the LIGO First Science Run in 2002, and report on the progress in the Second and Third Science Runs in 2003. Look here: pdf A picture.

Feb 13
Urs Langenegger, Universit&aumlt Heidelberg
Inclusive Determination of |V_ub|
I present two measurements of inclusive charmless semileptonic B decays obtained with the BABAR detector. The first is based on the lepton endpoint spectrum and the second on the hadronic invariant mass. I elaborate on the systematic errors in these measurements and discuss yet another world average of |Vub| from inclusive measurements.


Feb 20
James Beatty, Penn State
Particle Astrophysics and the Extreme Universe
Particle acceleration is ubiquitous in astrophysical contexts. The large scale of cosmic accelerators allows them to reach energies above 10^19 electron-volts, where interactions with the cosmic microwave background become significant. Experiments are now being constructed to probe this energy frontier, with possible impact on our thinking about both astrophysics and particle physisics at these energies. I will discuss the current status of work in this area, with emphasis on the cosmic ray spectrum above the Greisen-Zatsepin-Kuzmin cutoff and prospects for the detection of ultrahigh energy neutrinos resulting from the interaction of these cosmic rays with the microwave background.

Feb 27
Phil Rubin, George Mason / U of Edinburgh
Recent Results from NA48
A survey of recent activities by the NA48 Collaboration at CERN, including work which relates to CP-violation, rare and forbidden processes, chiral perturbation theory, and fundamental electroweak physics. pdf

March 5
Dave Tedeschi, U of South Carolina Columbia
Experimental Evidence for Pentaquark States
Recent experimental results suggesting exotic 5 quark baryons (pentaquarks) have been presented at international conferences and published in refereed scientific journals. These data are claimed to herald a new chapter in hadron spectroscopy. Taken collectively, the data paint a compelling picture; however, valid criticism regarding the analysis methods and the statistical significance of individual experiments can not be ignored. In this presentation I will briefly review the theoretical interpretations of these states and then present the world's data regarding pentaquarks. pdf

March 12
Harry Nelson, UCSB
The Cryogenic Dark Matter Search
Over the past decade, the case for dark matter in the Universe has continuously strengthened. One of the most intriguing features of the dark matter abundance is that it can be produced, during the Big Bang, by a weak interaction cross section of the dark matter with our matter. Supersymmetry restored near the weak scale provides an attractive candidate for such a dark matter particle: the lightest superpartner, which is usually the neutralino. The Cryogenic Dark Matter Search is devoted to detection of neutralino-type particles which might consitute the dark matter. The experiment uses Germanium crystals cooled to cryogenic temperature and instrumented to record both the sound and ionization caused by a nucleus that recoils due to interaction with a dark matter particle. The latest revision of the CDMS experiment has recently commenced data taking in the Soudan mine in Northern Minnesota, and I will describe its status, recent results, and future prospects. pdf

March 19
Björn Lange, Cornell
Proposal for a precision measurement of |Vub| from inclusive B decays
Recently a calculational framework for inclusive B->Xu e nu decays has been presented which combines perturbative and non-perturbative quantities in a systematic fashion. In this talk I will focus on the phenomenology of these new results and discuss a few methods for the determination of |Vub|. Hadronic uncertainties are reduced due to our improved knowledge about the shape function, which will be discussed in some detail. It will be argued that cutting on a kinematic variable called "P+" is favored by the theoretical framework and provides us with an opportunity to improve the current accuracy for a |Vub| measurement. pdf

April 9
David Jaffe, BNL
K => pi,nu,nubar Results and Prospects
K => pi,nu,nubar decays have the potential to provide unambiguous and precise information on the CKM matrix. The latest results from BNL experiment E949 on K+ => pi+,nu,nubar will be presented. Prospects for the measurement of the K0L => pi0,nu,nubar branching fraction with KOPIO experiment at BNL will also be presented. pdf

April 16
Kurt Gottfried, Cornell
Scientific Knowledge and the Bush Administration
A number of prominent scientists have charged the Bush administration with distorting the input from science into its policy formation process and in its public advocacy. This controversy and the historical background will be discussed. pdf video

April 23
Fred Goldhaber, Stony Brook
Looking for Mr. Glueball
A simplified form of quantum chromodynamics holding significant conceptual interest is pure-glue QCD, in which no quarks appear, only gluon degrees of freedom. In such a theory the unique class of stable, isolable excitations would be glueballs, objects with zero net color charge made out of combinations of gluons. A glueball would be unstable only if it could decay to two or more glueballs with lower total mass. By contrast, in realistic QCD with light quarks, any object with the quantum numbers of a glueball (meaning eigenstate of CPT with integer spin and no flavor charges) could be mimicked by a suitable combination of quarks and antiquarks -- and so would be unstable against decay to combinations of conventional light hadrons. Clearly then, any convincing experimental detection of glueballs would have to overcome this intrinsic ambiguity. For some time, study of objects appearing in systems with heavy-quark pairs produced in electron-positron collisions has been a recognized route towards identifying glueballs. The discussion in this talk will be focused on final states of the form J/psi or Upsilon plus glueball.

Already there is some experimental evidence for the presence of the lowest-mass glueball in such channels. From the theoretical side, heuristic semiclassical reasoning and also perturbative QCD estimates give qualitative, but not yet quantitatively precise, indications of the effects to be expected.

April 30
John Cumalat, U of Colorado Boulder
Recent Charm Meson Results from the FOCUS Collaboration
I will briefly describe the FOCUS experiment and will comment on some of our ongoing analysis efforts and analysis techniques. I will discuss our recent results on the excited D** state and I will report on D0 and D+ decays into four, five , and six body final states including the measurement of a new Cabibbo favored D0 decay. I will also describe our recent form factor results for D+(s) -> phi l nu. Finally, I will also mention a FOCUS search for the charm pentaquark. pdf

May 6
Klaus Peters, Bochum
Dalitz Plot Analysis Techniques
The discovery and investigation of broad resonances is a very complicated and sometimes error-prone procedure. In the past many meson and baryon resonances have been identified as analysis artefacts due the limitations in the analysis process. Due to small statistics and the absence of S-wave dominated channels it was not possible to overcome this situation easily.

The investigation of high statistics data sets being available from Crystal Barrel at LEAR and other experiments have changed our knowledge of the methods, formalisms and their application in partial wave analysis dramatically and many new techniques have been developed since then.

The Dalitzplot analysis as one typical example of modern partial wave decomposition will be discussed in great detail emphasizing modern trends as well as technical and theoretical problems which still have to be solved.
ppt pdf

May 7
Mikhail Voloshin, UMinn
Charmonium at the open charm treshold
I discuss few topics that can be studied in e^+e^- annihilation in the region of the psi(3770) resonance. The relative yield of pairs of neutral and charged D meson pairs presents and interesting problem related to strong dynamics of heavy mesons. I argue that this relative yield should display an interesting variation across the resonance. A study of transitions from psi(3770) to charmonium levels may help understand the internal structure of this resonance. I discuss possible hadronic transitions of this type. The dynamics of heavy meson pairs near the threshold is likely to involve so-called "molecular" states. Some properties of such states near the open charm threshold are discussed. ps

May 14
Konstantin Matchev, U Florida/Cornell
Dark Matter and Physics Beyond the Standard Model at Colliders
In this talk I will consider the implications of dark matter for collider searches for new physics beyond the Standard Model. I will first derive a model-independent prediction for the production rates of dark matter particles at colliders (in association with soft photons or jets). I will then introduce several new physics scenarios with particle dark matter candidates and discuss the potential of the high energy collider experiments at the Tevatron, LHC and NLC to distinguish among them, and to perform precision measurements of the dark matter properties. I will also speculate on the precision with which the LHC and the NLC can test the thermal relic hypothesis.

May 21
Jim Thomas, LBNL
On the Trail of a Strongly Interacting Plasma at RHIC
The Relativistic Heavy Ion Collider was built for the purpose of discovering the Quark Gluon Plasma. We may have achieved that goal. I will describe the facilities at RHIC and discuss a few key pieces of data that have lead our theoretical colleagues to declare success. I will also discuss why the experimental community is more cautious about drawing this conclusion.
My talk will be given from the detector builders point of view and I will focus on those things we know for sure.

"A theory is something nobody believes, except the person who made it. An experiment is something everybody believes, except the person who made it." (Attributed to Albert Einstein.) ppt

June 11
Alan Schwartz, Cincinnati
New Results from the Belle Experiment: Observation of Large CP Violation in B->pi+pi- Decays
The Belle experiment began running in 1999 and to-date has recorded over 260 fb^-1 of data. Using 140 fb^-1 of data, we have observed large CP Violation in B->pi+pi- decays, and first evidence for direct CP violation in B decays. From this measurement we set a model-independent constraint on the CKM phase angle phi_2 (alpha) and also on the ratio of penguin to tree amplitudes. The analysis has undergone numerous checks; details of the analysis will be reviewed. pdf

June 25
Leslie Rosenberg, LLNL
The Axion Dark Matter Experiment
Recent measurements solidified what was already a strong case for abundant cold dark matter in the universe. These same measurements elevated the axion, a hypothetical elementary particle, to a premier cold dark matter candidate. Dark matter axions have almost no interactions with normal matter and radiation, but in a RF cavity threaded by a large static magnetic field, a handful per second would convert into microwave photons. These photons can be detected by an exquisitely sensitive microwave receiver. This detector is fully operational and continues to search for axions in our Milky Way halo. We are starting a high-sensitivity upgrade that exploits advances in SQUID microwave amplifier technology. The final stage of this upgraded experiment will be definitive, sensitive to the entire range of plausible dark matter axion masses and couplings. pdf

July 9
Andy Hocker, Rochester
Top Physics Results From TeVatron Run II
Since its discovery in 1995, the top quark has been the subject of an intense experimental program at Fermilab's TeVatron collider. The higher luminosities at Run II of the TeVatron allow us to more fully characterize the properties of this heaviest quark. I will provide an overview of the Run II top program and review recent results from the CDF and D0 experiments in this area, covering measurements of the production cross section, mass, branching ratios, and other properties of top. pdf

July 16
Ed Blucher, Chicago
A New Determination of |V_us| from KTeV
I will present a determination of the CKM parameter |Vus| based on new measurements of the six largest KL branching fractions and semileptonic form factors by the KTeV experiment at Fermilab. Several of the results are not in good agreement with averages of previous measurements. Our new determination of |Vus| is consistent with unitarity of the CKM matrix. pdf

August 5
Steve Olsen, Hawaii
The X(3872); charmonium or a new type of meson?
The X(3872) is a narrow charmonium-like state seen by Belle in the pi+pi- J/psi system in exclusive B-->K pi+pi-J/psi decays. Assignment to any of the as yet unseen charmonium states that are expected to be narrow has proven to be problematic. Its mass is higher and its gamma chi_c1 decay width smaller than expectations for the 3D2 state and the 1D2 decay to pipi J/psi violates isospin and is expected to be highly suppressed. The helicity angle distribution of the J/psi rules out the 2(1P1) assignment. The close proximity of its mass with M(D0)+M(D0*) suggests that the X(3872) may be a "molecule-like" D-D*bar bound state. If this is the case, this would imply a new spectroscopy in the 4 GeV mass region.

In this talk I will summarize recent searches for the X(3872) in other decay channels and the implications on possible interpretations of this particle. In addition I will present some unpublished results from E_cm=4.03~GeV BES data that may (or may not) be related and might have relevance to CLEO-c. pdf