CLASSE: LEPP Journal Club

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CORNELL LABORATORY FOR ACCELERATOR-BASED SCIENCES AND EDUCATION

Seminars take place at Newman 311, 4:00 PM (refreshments at 3:45 PM), unless announced otherwise.
Fall 2005

Abstracts and Transparencies

Previous seminars

DATE SPEAKER INSTITUTION SEMINAR TITLE
Fri Sep 2

Fri Sep 9 ---- NO JOURNAL CLUB -- CLEO Meeting

Fri Sep 16 Erich Mueller Cornell Routes to new physics with rotating cold gases

Fri Sep 23 Jo Dudek Jefferson Lab Charmonium Radiative Transitions on the Lattice

Fri Sep 30 Dan Marlow Princeton CMS Luminosity Measurement

Fri Oct 7 Bruce Behrens CNA CNA, the Navy, and assorted analyses

Wed Oct 12 Shuwei Ye U. of Texas, Dallas Y(4260): a broad strucutre in e+e- -> ISR pi+pi-J/psi

Thu Oct 13 Matthias Liepe Cornell The Cornell ERL: A Heart of Niobium

Fri Oct 14 Dick Loveless U. of Wisconsin CMS Endcap Muon System

Fri Oct 21 ---- NO JOURNAL CLUB -- CLEO Meeting

Fri Oct 28 Pablo Hopman MIT Lincoln Lab High-Rate, Deep-Space Optical Communications: 30 Mbits/second from Mars

Tue Nov 1 Eduard Pozdeyev Jefferson Lab Experimental Results from the Small Isochronous Ring at Michigan State University

Fri Nov 4 Dinko Pocanic U. of Virginia New results on pion rare decays

Wed Nov 9 Richard Hill Fermilab The shape of semileptonic B and D decay form factors: Applications and precision tests

Fri Nov 11 Richard Talman Cornell Conversion of CESR to Bright X-Ray Source

Fri Nov 18 ---- NO JOURNAL CLUB -- PAC Meeting

Fri Nov 25 ---- NO JOURNAL CLUB -- Thanksgiving

Tue Nov 29 Val Prasad Yale University Search for the Electron Electric Dipole Moment

Wed Nov 30 Alexey Garmash Princeton University B meson decays to three-body charmless hadronic final states

Thu Dec 1 Monica Dunford University of Pennsylvania Beyond Fluxes with the Sudbury Neutrino Observatory

Fri Dec 2 ---- NO JOURNAL CLUB -- CLEO Meeting

Fri Dec 9 Gil Paz Cornell An Inclusive Look at Charmless Inclusive B Decays

Fri Dec 16 Peter Fisher MIT The Alpha Magnetic Spectrometer [CANCELLED]

September 16
Erich Mueller, Cornell
Routes to new physics with rotating cold gases
I will talk about recent advances in ultracold atomic gases. I will focus on attempts to use rotating to create exotic states of matter, and some of the experimental hurdles that must be overcome. I will try to emphasize some areas where there are analogies in high energy/ accelerator physics, such as how recent experiments have been using "betatron resonances" to cool atomic clouds. pdf

September 23
Jo Dudek, Jefferson Lab
Charmonium Radiative Transitions on the Lattice
I will discuss work done in the Jefferson Lab Theory Center which simulates radiative transitions between the lightest charmonium states using lattice QCD. This is the first such study in the charmonium sector and preliminary results appear to be consistent with experimental data. Obtaining physically measurable quantities involves a fusion of lattice computation with extrapolations based on successful quark-potential models. Eventually it is hoped that this method can be applied to the light-quark sector and in particular transitions involving the hypothetical hybrid mesons which it is believed will be probed at the forthcoming JLab experiment: GlueX. ppt

September 30
Dan Marlow, Princeton
CMS Luminosity Measurement
Various techniques for monitoring the luminosity at CMS will be described. Simulation results will be presented and the plans for recording and tracking luminosity information will be reviewed. ppt

October 12
Shuwei Ye, U. of Texas, Dallas
Y(4260): a broad strucutre in e+e- -> ISR pi+pi-J/psi
We (BaBar) study initial-state radiation events, $e^+e^-\to\gamma_{ISR}\pi^+\pi^-J/\psi$, with data collected with the BaBar detector. We observe an accumulation of events near 4.26~GeV/$c^2$ in the invariant-mass spectrum of $\pi^+\pi^-J/\psi$. Fits of the mass spectrum indicate that a broad resonance with a mass of about 4.26~GeV/$c^2$ is required to describe the observed structure. The presence of additional narrow resonances cannot be excluded. The fitted width of the broad resonance is 50 to 90~MeV/$c^2$, depending on the fit hypothesis. ppt

October 14
Dick Loveless, U. of Wisconsin
CMS Endcap Muon System
ppt

October 28
Pablo Hopman, MIT Lincoln Lab
High-Rate, Deep-Space Optical Communications: 30 Mbits/second from Mars
NASA anticipates a significant demand for long-haul communications service from deep-space to Earth in the near future. To address this need, a substantial amount of work has gone into developing a free-space laser communications system that can be operated at data rates that are 10-1000 times more capable than current RF systems. In this talk I will overview the challenges of deep-space optical communications and describe the Mars Laser Communications Demonstration program with a focus on the ground receiver architecture. The ground receiver uses photon counting communication techniques made possible by Geiger-Mode Avalanche Photo Diode (GM-APD) detectors. I will describe the GM-APD focal plane array being developed for a distributed photon counting communications ground receiver. pdf

November 1
Eduard Pozdeyev, Jefferson Lab
Experimental Results from the Small Isochronous Ring at Michigan State University

The Small Isochronous Ring (SIR) is a compact, low-energy storage ring designed to experimentally investigate the beam dynamics in high-intensity isochronous cyclotrons and synchrotrons at the transition energy. The ring was developed at Michigan State University and has been operational since December 2003. It stores 20 keV hydrogen beams with a peak current of 20 microamperes for up to 200 turns. The transverse and longitudinal profiles of extracted bunches are measured with an accuracy of approximately 1 mm. The high accuracy of the measurements makes the experimental data extremely attractive for validation of multi-particle space charge codes.

The experimental results obtained in the ring show a fast growth of the energy spread induced by the space charge forces. The energy spread growth is accompanied by a longitudinal breakup of the beam bunches into completely separated clusters that are involved in the vortex motion specific to the isochronous regime. The experimental results show a remarkable agreement with simulations performed with the code CYCO.

In this talk, I'll discuss specifics of space charge effects in the isochronous regime, describe the design of the ring, present results of experiments in SIR, and compare the experimental data with results of simulations. I'll also describe possible ring upgrade scenarios.

pdf

November 4
Dinko Pocanic, U. of Virginia
New results on pion rare decays
The PIBETA project, a program of precise study of rare pion and muon decays at PSI, has been active for several years and is now producing results. The collaboration uses a large spherical electromagnetic calorimeter with central tracking and an active target for stopped Pi+ beam. I will discuss results on pion beta decay (Pi+ -> Pi0 e+ Nu), radiative decays Pi+ -> e+ Nu gamma, Mu+ -> e+ Nu Nu-bar gamma, as well as our plans for a new measurement of the decay Pi+ -> e+ Nu. pdf

November 9
Richard Hill, Fermilab
The shape of semileptonic B and D decay form factors: Applications and precision tests
Understanding the energy spectrum in exclusive semileptonic B decays, encoded by the relevant form factors, is important for a precise extraction of |V_ub|. The spectral data also enables quantitative tests of theoretical methods, and the determination of fundamental QCD parameters. In this talk, the general description of heavy-to-light form factors emerging from the heavy-quark and soft-collinear effective field theories is outlined, motivating the introduction and study of particular form factor shape observables. The necessary statistical apparatus to rigorously extract these observables from the data is described, and several new applications of the semileptonic B and D decay data are discussed. pdf

November 29
Val Prasad, Yale University
Search for the Electron Electric Dipole Moment
The Demille Group at Yale is searching for the electron electric dipole moment (EDM) using lead oxide molecules. The expected senseitivity of the experiment is 10^-29 e-cm, two orders of magnitude lower than the current limit of 1.6 x 10^-27 e-cm. Although the Standard Model expected value for the electron EDM is more than 13 orders of magnitude lower than the target sensitivity of the experiment discussed, some extensions to the Standard Model allow for an electron EDM which should be observable by the experiment. Progress towards this high-precision measurement will be described. ppt

November 30
Alexey Garmash, Princeton University
B meson decays to three-body charmless hadronic final states
Decays of B mesons to three-body charmless hadronic final states have attracted considerable attention in recent years as they provide not only a rich laboratory for studying B meson decay dynamics but also new possibilities for CP violation studies. Some of the final states considered so far as two-body (for example B=>rho pi, K* pi, etc.) proceed via quasi-two-body processes involving a wide resonance state that immediately decays in the simplest case to two particles, thereby producing a three-body final state. Multiple resonances occurring nearby in phase space will interfere and a full amplitude analysis is required to extract branching fractions for the intermediate quasi-two-body states. Several three-body final states have been used recently for CP violation searches. Analysis of time-dependent CP violation has been done with three-body K+K-K0 and KsKsKs final states. The first evidence for direct CP violation in B+ => rho(770)0K+ has been found via an amplitude analysis of the three-body B+ => K+pi+pi- decay. Results on studies of three-body charmless B decays to be presented in this talk are based on large data sample collected by Belle detector operating at KEKB asymmetric energy e+e- collider with a center of mass energy at Y(4S) resonance. pdf

December 1
Monica Dunford, University of Pennsylvania
Beyond Fluxes with the Sudbury Neutrino Observatory
In the past few years, the Sudbury Neutrino Observatory has demonstrated that the total active flux of neutrinos observed is consistent with the standard solar model prediction although there is a suppression in the number of electron neutrinos observed from the sun . The Mikheev-Smirnov-Wolfenstein model which is used to describe the observed electron neutrino suppression also predicts a distortion in the neutrino energy spectrum and/or a difference in electron neutrino survival probability day verses night. Neither of these predictions have been observed. Additionally, certain models of non-standard interactions also predict a distortion of the neutrino energy spectrum. This talk discusses the physics potential of a spectral measurement to test these predictions and focuses on the experimental challenge of lowering the analysis energy threshold in SNO in order to be more sensitive to observing spectral distortions. pdf

December 9
Gil Paz, Cornell
An Inclusive Look at Charmless Inclusive B Decays
Over the last two years there has been a considerable theoretical research effort that would lead to a high precision measurement of the CKM matrix element |Vub| from inclusive charmless B decays. Accurate determination of |Vub| would allow us to test the Standard Model and search for possible deviations from its predictions. In a series of papers, written in collaboration with Stefan Bosch, Bjorn Lange and Matthias Neubert, we have explored both the perturbative and non perturbative aspects of the problem. This effort has culminated in our latest "state-of-art" work on the extraction of |Vub|, which the BaBar and Belle experiments have already started to implement. pdf

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