Spring 2010:
1/21/10 - Ou Zhang (Peking University)
Time/Loc.: PAS 274 (3:30 PM, refreshments at 3:15)
Title: Discussions on Properties of X(3872),f0(980) and f0(600) Resonances
Abstract: The property of $X(3872)$ particle is discussed by carefully studying the experimental data available. We find that two poles near the $D^{*0}\bar D^0$ threshold are required in order to describe the data better. We suggest that the X(3872) particle is a $\bar cc$ state heavily distorted by the $D^{*0}\bar D^0$ threshold. Also, we estimate the diphoton coupling of f0(600), f0(980), and f2(1270) resonances in a coupled channel dispersive approach. Di-photon coupling of f0(600) and f0(980) resonances are extracted and their dynamical properties are discussed. Finally we study the physics meaning of the coupling constant $g^2_{\sigma\pi\pi}$, which maintains a negative real part as determined through dispersive analyses.
1/27/10 - Alexander Melnitchouk (University of Mississippi)
Time/Loc.: PAS 274 (2:30 PM, refreshments at 2:15)
Title: W Mass Measurement at the Tevatron
Abstract: Measurements of the W boson mass at the Tevatron are presented,
with a focus on the recent published results by D0 with integrated luminosity of 1 fb^-1.
Impact of the W boson mass measurement on constraining the Standard Model is discussed. Analysis strategy, experimental techniques, and primary sources of uncertainties are discussed. Analysis aspects related to D0 electromagnetic calorimeter, such as electron energy calibration are presented in detail. Selected topics from the current work in progress on the 5 fb^-1 measurement at D0 are described.
1/28/10 - Chieh Jen Yang (Ohio University)
Time/Loc.: PAS 218 (3:30 PM, refreshments at 3:15)
Title: Subtractive Renormalization of Chiral Effective Theory NN Potentials Up To Next-To-Next-To Leading Order
Abstract: We have developed a subtractive renormalization method with which we can
evaluate NN scattering phase shifts produced by the NN potential obtained at
leading, next-to-leading, and next-to-next-to-leading order (NNLO) in the
chiral effective theory. In this method the low-energy constants
associated with short-distance NN physics are eliminated from the
Lippmann-Schwinger equation (LSE) for the NN t-matrix, in favor of physical
observables. This allows to straightforwardly compute scattering phase
shifts for ultra-violet cutoffs of at least 10 GeV. We then perform detailed
analyses of several renormalization issues and determine the maximum cutoff
at which the use of an effective field NN potential in the LSE makes sense.
2/10/10 - Gianina Alina Negoita (Iowa State University)
Time/Loc.: PAS 218 (3:30 PM, refreshments at 3:15)
Title: Improving Convergence of Ab Initio No Core Nuclear Structure Methods
Abstract: Ab initio no core methods have now become major tools for understanding the properties of light nuclei based on realistic NN
and NNN interactions. Major new progress, including the goal to proceed to heavier nuclei, is limited by convergence issues - how to
obtain the exact solution of the nuclear Hamiltonian in a very large basis space. I have investigated (1) the similarity renormalization
group approach to softening the interaction, and (2) adoption of a realistic basis space using Woods-Saxon single-particle wavefunctions. Both have their advantages and limitations that I will discuss. In addition, I have made an initial investigation of the mass A = 47-49 region with the aim of preparing for nuclear double beta-decay studies. In these heavier systems, phenomenological additions to the realistic NN interaction are needed to fit the data.
Fall 2009:
10/20/09 - Giorgio Torrieri (Frankfurt Inst. of Theoretical Physics)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: Constraints on AdS/CFT Gravity Dual Models of Heavy Ion Collisions
Abstract: I will review the evidence that the matter created at RHIC is a strongly coupled medium with low viscosity, and argue that its properties are probably not describeable by perturbative QCD. I will then review the attempts to use AdS/CFT to describe the RHIC system, and argue that, while many results in this field are very interesting and promising, the statement "AdS/CFT techniques can adequately describe data at RHIC" is not as yet experimentally falsifiable. I conclude by showing how a simultaneus quantitative analysis of RHIC observables could provide a key to such a falsification.
11/23/09 - Michael Ramsey-Musolf (University of Wisconsin)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: Electroweak Baryogenesis: Theoretical Progress and Experimental Tests
Abstract: Explaining the origin of the visible matter of the universe is one of the outstanding problems at the interface of particle and nuclear physics with cosmology. It is possible that new physics at the electroweak scale my provide the necessary ingredients for successful baryogenesis. In this talk, I discuss recent theoretical developments in electroweak baryogenesis and their implications for experimental tests using both "table top" searches for permanent electric dipole moments and collider searches for new particles.
Spring 2009:
1/15/09 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
1/22/09 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
1/29/09 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
2/5/09 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
2/12/09 - Lisa Everett (Wisconsin U.)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: Two Stories About about Neutrino Masses and Lepton Flavor Mixing
Abstract: With the discovery of neutrino oscillations and the resulting measurement of lepton flavor mixing, new and exciting facets of the flavor puzzle of the Standard Model have been revealed. In this talk, two stories will be told about the possible origins of ultralight neutrino masses and large lepton flavor mixing angles. The first is about the possibility of naturally suppressed Dirac neutrino masses in models with additional low energy gauge symmetries. The second focuses on using icosahedral (A5) flavor symmetry to implement the intriguing idea that the solar neutrino mixing angle is related to the famed "golden ratio."
2/24/09 - Gouranga Nayak (Arizona U.)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: Parton to Hadron Fragmentation Function in Non-Equilibrium QCD Using Closed-Time Path Integral Formalism
Abstract: Since two nuclei at RHIC and LHC collide almost at speed of light, the quark-gluon plasma formed at RHIC and LHC may be in non-equilibrium. In this talk I will show how to implement Schwinger-Keldysh closed-time path integral formalism in non-equilibrium QCD to Collins-Soper fragmentation function, to study hadron formation from non-equilibrium quark-gluon plasma at RHIC and LHC. For a high p_T parton at initial time at RHIC and LHC I will formulate parton to hadron fragmentation function in non-equilibrium QCD using light-cone quantization formalism.
2/26/09 - Zhenyu Han (U.C. Davis)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: Measuring the Dark Force at the LHC
Abstract: A long-range "dark force" has been proposed to explain the PAMELA and ATIC anomalies in the positron/electron spectra. In this scenario, if dark matter particles are copiously produced at the Large Hadron Collider, the light dark force mediator will also be produced through radiation. I will discuss how to determine the dark matter mass, the light mediator mass, and the coupling constant of the dark force at the LHC.
3/5/09 - Radovan Dermisek (Indiana U.)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: Many light Higgs bosons in MSSM-like models
Abstract: We discuss a simple scenario in which all the Higgs bosons resulting from two Higgs doublets (MSSM-like): the light and heavy CP even Higgses, the CP odd Higgs and the charged Higgs could have been produced already at LEP or the Tevatron but would have escaped detection because they decay in modes that have not been searched for or the experiments are not sensitive to. This scenario can be realized in many models. We discuss specific predictions of this scenario in the next-to-minimal supersymmetric model.
3/12/09 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
3/19/09 - Spring Recess (No Talk Scheduled)
3/26/09 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
4/2/09 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
4/9/09 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
4/16/09 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
4/23/09 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
4/30/09 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
5/7/09 - Bingwei Long (ECT*)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: Pion-nucleon scattering in the Delta(1232) region in an EFT
Abstract: The Delta(1232) resonance is important in low-energy strong-interaction physics due to its small excitation above the nucleon. Pion-nucleon scattering provides a stage to investigate the role of the delta. We develop a generalized version of heavy-baryon chiral perturbation theory to describe pion-nucleon scattering in a kinematic domain that extends continuously from threshold to the delta-isobar peak. The P-wave phase shifts are used to illustrate this framework. We also compare our approach with those in the literature that concern the delta resonance.
Fall 2008:
8/28/08 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
9/4/08 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
9/11/08 - Dan Hooper (FNAL)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
9/18/08 - Shalom Shlomo (TAMU)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: Modern Energy Density Functional For Properties Of Nuclei and Nuclear Matter
Abstract: The development of a modern and more realistic nuclear energy density functional (EDF) for accurate predictions of properties of nuclei is the subject of enhanced activity, since it is very important for the study of properties of rare nuclei with unusual neutron-to-proton ratios that are difficult to produce experimentally and likely to exhibit interesting new phenomena associated with isospin, clusterization and the continuum. Adopting the standard parametrization of the Skyrme type interactions, we have recently determined within the Hartree-Fock (HF) approximation a new and more realistic Skyrme interaction by carrying out a fit to an extensive set of experimental data on; (i) binding energies, (ii) "bare single-particle energies, (iii) charge root-mean-square (rms) radii, (iv) rms radii of valence neutron orbits, and the energies of isoscalar giant monopole resonances (ISGMR). We have also imposed additional constraints; (i) Landau stability constraints on nuclear matter (NM), and (ii) non-negativity of the slope of the symmetry energy density at high density of NM (up to three times the saturation density of NM), which is of importance in the study of properties of neutron star. We will present results of our calculations of properties of nuclei and NM by employing our newly obtained EDF and address the issues: (i) The isospin dependence of the spin-orbit (SO) interactions and the SO splitting of neutron and proton orbits in neutron- and proton-rich nuclei. (ii) The effects of long-range correlations, beyond the mean-field, on ground-state properties of nuclei. We point out that for consistency, one must require that the comparison with experimental data be made after the inclusion of the effects of correlations. (iii) The equation of state (EOS) of symmetric and asymmetric NM. The EOS of NM is an important ingredient in the study of various properties of
nuclei, heavy ion collisions, supernovae and neutron stars. Accurate values of the NM incompressibility coefficient ,K, and the symmetry energy, J, are needed in order to extend our knowledge of the EOS in the vicinity of the saturation point of the symmetric NM and for asymmetric NM
9/25/08 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
10/2/08 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
10/9/08 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
10/14/08 - Peter Loch (Arizona)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30) Note the special day (Tuesday) and time!
Title: Everything You Wanted to Know About Jets but Were Afraid to Ask
Abstract: Jet reconstruction is an important part of the general event analysis in all hadron collider experiments. In particular, the presently commissioned Large Hadron Collider (LHC) at the CERN laboratory in Geneva, Switzerland, will soon produce hadronic final states in its proton-proton collisions at a center-of-mass energy of 14 TeV which are dominated by particle jets, rather than individual and isolated particles. In this talk an overview on the detection and reconstruction of these jets in ATLAS, one of the two big multi-purpose detectors at LHC, is given together with some general overview of this complex task. The signal formation in the detectors of choice for jet reconstruction, the ATLAS calorimeters, is presented briefly, and effects disturbing the measurement are discussed with examples for the corresponding correction and signal unfolding strategies. In addition, the expected effect of the particular physics collision environment at LHC are shown. Also included are a brief discussion on the why and how of triggering and a brief view on strategies for the experimental determination of the origin of particle jets. The talk focuses on experimental aspects and is generally at an introductory level.
10/16/08 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
10/21/08 - Ionel Stetcu (LANL)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30) Note the special day (Tuesday) and time!
Title:Recent Applications Of the No-Core Shell Model To Few-Body Problems
Abstract: I will discuss different applications of the no-core shell model (NCSM) to few-body systems. In particular, I will concentrate on the details of the recent calculation of the nuclear electric dipole and Schiff moments of 3He, as well as electric polarizabilities of three- and four-body systems. Finally, I will discuss current efforts to link R-matrix theory to the underlying NN and NNN interactions by means of NCSM.
10/30/08 - Gary Shiu (Wisconsin)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: Warped String Models: Cosmology and Particle Physics
Abstract: T.B.A.
11/6/08 - Ruprecht Machleidt (University of Idaho)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title:Chiral Three-Nucleon Forces Beyond Next-To-Next-To-Leading Order
Abstract: In recent years, there has been substantial progress in the derivation of nuclear forces from chiral effective field theory. Accurate two-nucleon forces (2NF) have been constructed up to next-to-next-to-next-to-leading order (N3LO) and applied with a good amount of success. However, chiral three-nucleon forces (3NF) have been used only at N2LO, improving some microscopic predictions, but leaving also several issues, like the "Ay puzzle", unresolved. Thus, the 3NF at N3LO is needed for essentially two reasons: for consistency with the 2NF and to (hopefully) improve some critical predictions. However, there are indications that the 3NF at N3LO is rather weak and may not solve any of the outstanding nuclear structure problems. If this suspicion is confirmed, we have to go beyond N3LO, which will open a Pandora's Box. Strategies for how to deal with this nightmare will be discussed.
11/10/08 - Herb Fried (Brown University)
Time/Loc.: PAS 218 (4:00 PM, refreshments at 3:45) Note the special day (Monday) and time!
Title: Virtual Gluon Ghosts in QCD
Abstract: A unique method of producing manifest gauge invariance in the functional sum over all virtual gluons exchanged (including cubic and quartic gluon interactions) between a pair of quarks and/or antiquarks in a quenched, eikonal model forces the gluons to act as "ghost particles", and results in a very simple, "almost local" set of ordinary integrals, susceptible to numerical integration, whose qualitative properties - effective, coherent exchanges at large impact parameters, but color fluctuations which destroy that coherence at small impact parameters -provide a justification of the MIT Bag Model and asymptotic freedom. The gauge invariance and ghost properties hold for all possible corrections to the quenched and eikonal models, which merely increase the complexity of the final integrals. Our "ghost" results are compatible with previous field-strength analyses, while the application to scattering problems is new.
11/13/08 - J. Ruben Morones Ibarra (Autonoma de Nuevo Leon, Arizona)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: Mass Shift Of the Sigma Meson In Nuclear Medium
Abstract: The mass modification in medium of the sigma meson is studied in the Walecka Model, considering that the sigma couples to a pair of nucleon-antinucleon states and to particle-hole states, including the in medium effect of sigma-omega mixing. It was found that the sigma meson mass decreases respect to its value in vacuum, and that the contribution of the sigma omega mixing effect is very small.
11/20/08 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.
11/27/08 - Thanksgiving (No Talk Scheduled)
12/2/08 - Jimmy Rotureau (Arizona)
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: Shell Model Approach to Many-Body Open Quantum Systems
Abstract: A lot of progress have recently been made in the development of radioactive beam and remote parts of the nuclear chart which were previously out of of reach experimentally can now be explored. The nuclei located in these regions ie in the vicinity or beyond the neutron (proton) drip-line have very different properties from the well-bound nuclei in the valley of stability. The presence of weakly-bound states, halo structures and strong coupling to the continuum, to mention a few, are typical features of these exotic nuclei and require new models and theories to describe them. During my talk, I will present two models based on the shell model formalism in which the coupling with the continuum is taken into account to describe nuclei in these remote regions. These models are the Shell Model Embedded with the Continuum (SMEC) and the Gamow Shell Model (GSM). I will present the main ideas of the two models and I will show their application for the two-proton radioactivity with the SMEC formalism and the description of light nuclei with the Gamow Shell model.
12/11/08 - T.B.A.
Time/Loc.: PAS 218 (3:45 PM, refreshments at 3:30)
Title: T.B.A.
Abstract: T.B.A.