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Full-Text Articles in Physical Sciences and Mathematics
Generalized Polarizabilities And The Chiral Structure Of The Nucleon, Thomas R. Hemmert, Barry R. Holstein, Germar Knöchlein, Stefan Scherer
Generalized Polarizabilities And The Chiral Structure Of The Nucleon, Thomas R. Hemmert, Barry R. Holstein, Germar Knöchlein, Stefan Scherer
Physics Department Faculty Publication Series
No abstract provided.
Dynamics Of Diblock Copolymers In Dilute Solutions, Radu P. Mondescu, M. Muthukumar
Dynamics Of Diblock Copolymers In Dilute Solutions, Radu P. Mondescu, M. Muthukumar
Physics Department Faculty Publication Series
No abstract provided.
Product Einstein Manifolds, Zeta-Function Regularization And The Multiplicative Anomaly, Andrei A. Bytsenko, Floyd L. Williams
Product Einstein Manifolds, Zeta-Function Regularization And The Multiplicative Anomaly, Andrei A. Bytsenko, Floyd L. Williams
Physics Department Faculty Publication Series
The global additive and multiplicative properties of Laplace type operators acting on irreducible rank 1 symmetric spaces are considered. The explicit form of the zeta function on product spaces and of the multiplicative anomaly is derived.
Combining Exclusive Semi-Leptonic And Hadronic B Decays To Measure |V Ub|., João M. Soares
Combining Exclusive Semi-Leptonic And Hadronic B Decays To Measure |V Ub|., João M. Soares
Physics Department Faculty Publication Series
No abstract provided.
Charm Physics 1996 - A Retrospective, E Golowich
Charm Physics 1996 - A Retrospective, E Golowich
Physics Department Faculty Publication Series
A pedagogically oriented review is given of progress made over the past year in our understanding of physics related to the charm quark. Included are discussions of the Rc deficit, the ψ′ anomaly, charm spectroscopy, D nonleptonic decays, searches for flavor-changing neutral currents, new limits on mixing and prospects for future experimental studies of the charm sector.
Chiral Perturbation Theory And Nucleon Polarizabilities, Br Holstein
Chiral Perturbation Theory And Nucleon Polarizabilities, Br Holstein
Physics Department Faculty Publication Series
Compton scattering offers in principle an intriguing new window on nucleon structure. Existing experiments and future programs are discussed and the state of theoretical understanding of such measurements is explored.
Some Possibilities For Charm Studies At B-Factories, Eugene Golowich
Some Possibilities For Charm Studies At B-Factories, Eugene Golowich
Physics Department Faculty Publication Series
To provide focus to my review of charm theory at the B-Physics and CP-Violation conference, I consider theoretical issues related to possible charm studies at B-factories. A few topics of interest to the author are stressed -- rare decays, CP-violating asymmetries and ${\bar D}^0 - D^0$ mixing.
Final State Rescattering As A Contribution To B->Rho Gamma, Jf Donoghue, Eugene Golowich, Aa Petrov
Final State Rescattering As A Contribution To B->Rho Gamma, Jf Donoghue, Eugene Golowich, Aa Petrov
Physics Department Faculty Publication Series
We provide a new estimate of the long-distance component to the radiative transition $B \to \rho \gamma$. Our mechanism involves the soft-scattering of on-shell hadronic products of nonleptonic $B$ decay, as in the chain $B \to \rho\rho \to \rho\gamma$. We employ a phenomenological fit to scattering data to estimate the effect. The specific intermediate states considered here modify the $B \to \rho \gamma$ decay rate at roughly the $5 \to 8%$ level, although the underlying effect has the potential to be larger. Contrary to other mechanisms of long distance physics which have been discussed in the literature, this yields a …
Isospin Mixing And Model Dependence, Es Na, Br Holstein
Isospin Mixing And Model Dependence, Es Na, Br Holstein
Physics Department Faculty Publication Series
We show that recent calculations of ΔI=3/2 effects in nonleptonic hyperon decay induced by md-mu≠0 are subject to significant model dependence. [S0556-2821(97)04819-4]
Delta(1232) And The Polarizabilities Of The Nucleon, Tr Hemmert, Br Holstein, J Kambor
Delta(1232) And The Polarizabilities Of The Nucleon, Tr Hemmert, Br Holstein, J Kambor
Physics Department Faculty Publication Series
Previous calculations of the polarizabilities of the nucleon within the framework of heavy baryon chiral perturbation theory have included the contribution of the Δ(1232) only in its effects on various contact terms or have been performed in chiral SU(3) where systematic errors are difficult to control. Herein, we perform a corresponding calculation in chiral SU(2) wherein Δ(1232) is treated as an explicit degree of freedom and the expansion is taken to third order in soft momenta, the pion mass, and the quantity MΔ-MN, collectively denoted ε. We present the results of a systematic O(ε3) calculation of forward Compton scattering off …
Chiral Sum Rules To Second Order In Quark Mass, E Golowich, J Kambor
Chiral Sum Rules To Second Order In Quark Mass, E Golowich, J Kambor
Physics Department Faculty Publication Series
A new calculation of the isospin and hypercharge axial-vector current propagators [ ΔA33μν(q2) and ΔA88μν(q2)] to two loops in SU(3)×SU(3) chiral perturbation theory is used to derive chiral spectral function sum rules valid to second order in the light quark masses. Explicit forms are given for the three-pion isospin axial-vector spectral functions at low energy, and application of the sum rules to the determination of counterterms of the chiral Lagrangian is discussed.
K-L->Pi(0)Gamma E(+)E(-) And Its Relation To Cp And Chiral Tests, Jf Donoghue, F Gabbiani
K-L->Pi(0)Gamma E(+)E(-) And Its Relation To Cp And Chiral Tests, Jf Donoghue, F Gabbiani
Physics Department Faculty Publication Series
The decay KL→π0γe+e- occurs at a higher rate than the nonradiative process KL→π0e+e-, and hence can be a background to CP violation studies using the latter reaction. It also has interest in its own right in the context of chiral perturbation theory, through its relation to the decay KL→π0γγ. The leading order chiral loop contribution to KL→π0γe+e-, including the (qe++qe-)2/mπ2 dependence, is completely calculable. We present this result and also include the higher order modifications which are required in the analysis of KL→π0γγ.
Virtual Compton Scattering Off The Nucleon In Chiral Perturbation Theory, Tr Hemmert, Br Holstein, G Knochlein, S Scherer
Virtual Compton Scattering Off The Nucleon In Chiral Perturbation Theory, Tr Hemmert, Br Holstein, G Knochlein, S Scherer
Physics Department Faculty Publication Series
We investigate the spin-independent part of the virtual Compton scattering (VCS) amplitude off the nucleon within the framework of chiral perturbation theory. We perform a consistent calculation to third order in external momenta according to Weinberg’s power counting. With this calculation we can determine the second- and fourth-order structure-dependent coefficients of the general low-energy expansion of the spin-averaged VCS amplitude based on gauge invariance, crossing symmetry, and the discrete symmetries. We discuss the kinematical regime to which our calculation can be applied and compare our expansion with the multipole expansion by Guichon, Liu, and Thomas. We establish the connection of …
Electromagnetic Mass Differences Of Pions And Kaons, Jf Donoghue, Af Perez
Electromagnetic Mass Differences Of Pions And Kaons, Jf Donoghue, Af Perez
Physics Department Faculty Publication Series
We use the Cottingham method to calculate the pion and kaon electromagnetic mass differences with as few model-dependent inputs as possible. The constraints of chiral symmetry at low energy, QCD at high energy, and experimental data in between are used in the dispersion relation. We find excellent agreement with experiment for the pion mass difference. The kaon mass difference exhibits a strong violation of the lowest order prediction of Dashen’s theorem, in qualitative agreement with several other recent calculations.
Asymptotic Limits And The Structure Of The Pion Form Factor, Jf Donoghue, Es Na
Asymptotic Limits And The Structure Of The Pion Form Factor, Jf Donoghue, Es Na
Physics Department Faculty Publication Series
We use dispersive techniques to address the behavior of the pion form factor as Q2 → ∞ and Q2 → 0. We perform the matching with the constraints of perturbative QCD and chiral perturbation theory in the high energy and low energy limits, leading to four sum rules. We present a version of the dispersive input which is consistent with the data and with all theoretical constraints. The results indicate that the asymptotic perturbative QCD limit is approached relatively slowly, and give a model independent determination of low energy chiral parameters.
Factorization In Non-Leptonic Decays Of Heavy Mesons, Jf Donoghue, Aa Petrov
Factorization In Non-Leptonic Decays Of Heavy Mesons, Jf Donoghue, Aa Petrov
Physics Department Faculty Publication Series
We propose a QCD-based model for calculation of the non-perturbative corrections to the factorization approximation in the decays of heavy mesons. In the framework of the model, factorization in pseudoscalar transitions holds exactly at the leading order leaving the opportunity to calculate non-leading corrections consistently.
Effective Hamiltonian In The Problem Of A "Central Spin" Coupled To A Spin Environment, I Tupitsyn, Nikolai Prokof'ev, P Stamp
Effective Hamiltonian In The Problem Of A "Central Spin" Coupled To A Spin Environment, I Tupitsyn, Nikolai Prokof'ev, P Stamp
Physics Department Faculty Publication Series
We consider here the problem of a "giant spin", with spin quantum number S≫1, interacting with a set of microscopic spins. Interactions between the microscopic spins are ignored. This model describes the low-energy properties of magnetic grains or magnetic macromolecules (ferromagnetically or antiferromagnetically ordered) interacting with a surrounding spin environment, such as nuclear spins. Our aim is to give a general method for truncating the model to another one, valid at low energies, in which a two-level system interacts with the environmental spins, and higher energy terms are absorbed into a new set of couplings. This is done using an …
Bose-Einstein Condensation In A Harmonic Potential, Wj Mullin
Bose-Einstein Condensation In A Harmonic Potential, Wj Mullin
Physics Department Faculty Publication Series
We examine several features of Bose-Einstein condensation (BEC) in an external harmonic potential well. In the thermodynamic limit, there is a phase transition to a spatial Bose-Einstein condensed state for dimensionD≥2. The thermodynamic limit requires maintaining constant average density by weakening the potential while increasing the particle numberN to infinity, while of course in real experiments the potential is fixed andN stays finite. For such finite ideal harmonic systems we show that a BEC still occurs, although without a true phase transition, below a certain “pseudo-critical” temperature, even forD=1. We study the momentum-space condensate fraction and find that it vanishes …