Radiation reaction of classical hyperbolic oscillator: experimental signatures

When accelerated by a constant force in the lab frame, a classical charge experiences no self force. In this case, the particle radiates without dissipating its kinetic and potential energy. But what happens when the particle enters another region with equal and opposite acceleration? Does the oscillating charge lose its mechanical energy similar to a radiating dipole, even though it seems to lose no mechanical energy within each region of constant acceleration? In this paper, I will show how mechanical energy is transferred to radiation energy via the Schott energy when the particle crosses the boundary between the two regions. In particular, I will show how preacceleration, which is usually regarded as an unphysical effect of the Lorentz-Abraham-Dirac self force, is essential for the energy transfer. Moreover, I will show that the commonly adopted Landau-Lifshitz approximation, which removes preacceleration, introduces second-order secular energy error. On a more fundamental level, the validity of classical electrodynamics is in fact questionable because quantum effects are likely important. The classical prediction can be tested experimentally by observing frequency chirping of radiation, whereby micro physics leaves signatures on macroscopic scales. The required experimental accuracy is estimated. Trap experiment of this type is complementary to collider experiments that endeavor to observe radiation reaction for elementary particles.Comment: 42 pages, 8 figures. LLNL-JRNL-76463

Unitarity of exclusive quark combination model: Exotic hadron production, entropy change and charmonium production for colour-singlet many-quark system

Confinement indicates an asymptotic quark state not observable except its energy is zero. Unitarity indicates that the total probability of a definite state of quark system to transit to any final state is exactly one. This talk reviews some important conclusions/predictions from the basic properties like unitarity of the combination model, as addressed by the title. We also in the Postscript section address the bottom quark energy loss. In the discussions around the dinner table in the Rencontre, the author combined the large transverse momentum J/Psi suppression and the contribution to J/Psi by B decay in large transverse momentum, made the expectation that bottom quark energy loss could be quite similar as light quark for b quark transverse momentum enough larger than b quark mass. This refers to the physical picture of the jet-medium interaction introduced in la Rencontre de l'annee derniere.Comment: Prepared for the Proceedings of la 46th Rencontre de Moriond, QCD Sessio

Combination of Heavy Quark with Partons from Quark-Gluon Matter: a Scaling Probe

In relativistic heavy ion collisions, the cross section of heavy hadron production via the combination of a heavy quark with a light one from the quark-gluon matter can be factorized. It is the convolution of twist-4 combination matrix elements, the parameters corresponding to the parton distributions of the quark-gluon matter, as well as the hard partonic cross section of heavy quark production calculable in PQCD. These parton distributions and combination matrix elements are functions of a scaling variable which is the momentum fraction of the heavy quark w.r.t. the heavy hadron. In the same factorization framework, the combination matrix elements appear in other `simpler' processes and can be extracted. Taking them as inputs, comparing with data from RHIC and (future) LHC, we can get the parton distributions of the quark-gluon matter just as the similar way we get those of nucleon, pion, or photon, etc..Comment: 17 pages in A4 preprint form and 12pt, 2 figure

Pionization and Energy Loss

This is a version submitted to proceedings of sqm09. The space time of hard interaction induced radiation (collinear, double log) and jet-QGM-interaction-induced radiation (bremsstrahlung + pionization) is more clarified. A hand-drawing picture is attached for interested reader. To measure y=1.2 to 2.2 more suppressed (than y=0) open charm pT spectrum is predicted and suggested as a good test.Comment: revtex4 (V5

Exponential Decay of the lengths of Spectral Gaps for Extended Harper's Model with Liouvillean Frequency

In this paper, we study the non-self dual extended Harper's model with Liouvillean frequency. By establishing quantitative reducibility results together with the averaging method, we prove that the lengths of spectral gaps decay exponentially.Comment: A revised version with 1 figur

A Dynamic Programming Implemented 2x2 non-cooperative Game Theory Model for ESS Analysis

Game Theory has been frequently applied in biological research since 1970s. While the key idea of Game Theory is Nash Equilibrium, it is critical to understand and figure out the payoff matrix in order to calculate Nash Equilibrium. In this paper we present a dynamic programming implemented method to compute 2x2 non-cooperative finite resource allocation game's payoff matrix. We assume in one population there exists two types of individuals, aggressive and non-aggressive and each individual has equal and finite resource. The strength of individual could be described by a function of resource consumption in discrete development stages. Each individual undergoes logistic growth hence we divide the development into three stages: initialization, quasilinear growth and termination. We first discuss the theoretical frame of how to dynamic programming to calculate payoff matrix then give three numerical examples representing three different types of aggressive individuals and calculate the payoff matrix for each of them respectively. Based on the numerical payoff matrix we further investigate the evolutionary stable strategies (ESS) of the games.Comment: 9 pages 3 sub models to illustrate how dynamic programming is implemented to construct payoff matrix of 2x2 symmetric gam

Information-Theoretical Learning of Discriminative Clusters for Unsupervised Domain Adaptation

We study the problem of unsupervised domain adaptation, which aims to adapt classifiers trained on a labeled source domain to an unlabeled target domain. Many existing approaches first learn domain-invariant features and then construct classifiers with them. We propose a novel approach that jointly learn the both. Specifically, while the method identifies a feature space where data in the source and the target domains are similarly distributed, it also learns the feature space discriminatively, optimizing an information-theoretic metric as an proxy to the expected misclassification error on the target domain. We show how this optimization can be effectively carried out with simple gradient-based methods and how hyperparameters can be cross-validated without demanding any labeled data from the target domain. Empirical studies on benchmark tasks of object recognition and sentiment analysis validated our modeling assumptions and demonstrated significant improvement of our method over competing ones in classification accuracies.Comment: Appears in Proceedings of the 29th International Conference on Machine Learning (ICML 2012

Controlling azimuthal spoke modes in cylindrical Hall thruster using a segmented anode

Azimuthal spoke-like modes commonly occur in ExB discharges. The natural occurrence of the spoke mode is correlated with changes of plasma parameters. Here, instead of allowing these changes to occur naturally, we report a technique for actively controlling the spoke by adjusting the boundary condition at the anode. The technique is demonstrated using a cylindrical Hall thruster equipped with a segmented anode. By varying the voltage and the relative phases of the anode segments, properties of the azimuthal mode can be altered substantially, as shown by fast camera images and probe diagnostics. This technique may be extended to other Hall discharges in order to either induce or suppress azimuthal activities, and thereby controlling the operation and the performance of the devices

Large production rate of new Bs0π±B^0_s \pi^{\pm} and Ds±π±D^{\pm}_s \pi^{\pm} states in high energy multi-production process

The production rate of the X(5568) observed by D0 collabotation is quite large and can not be understood by various general hadronization mechanism. We propose an inclusive resonance production formulation to calculate the cross section and extract the value of the effective wave function at origin. Based on these results we suspect X($D_s \pi^{\pm}$) can be copiously produced and observable at high enenrgy scatterings (the relative production ratio to D_s is larger than 10 %). In the updated version the discussions on cluster model and FI are added. Both cases can not give large rate. Then we show that pion in X(5568) decay can only gain a very small momentum. In the pseudo-rapidity region [2,5], large part of the signal pions will be dismissed by the detector since the transverse mometum is too small and/or total momentum too small. If further requirement on pion tranverse mometum larger than 1GeV/c added, almost all signal pions are rejected. But for the charm partner, this problem does not exist since the charm partner can give a larger boost factor. A 3D distribution of signal pions are addedComment: 10 pages, 2 figure

Decay Constants of Pseudoscalar Mesons in Bethe-Salpeter Framework with Generalized Structure of Hadron-Quark Vertex

We employ the framework of Bethe-Salpeter equation under Covariant Instantaneous Ansatz to study the leptonic decays of pseudoscalar mesons. The Dirac structure of hadron-quark vertex function $\Gamma$ is generalized to include various Dirac covariants besides $\gamma_5$ from their complete set. The covariants are incorporated in accordance with a power counting rule, order by order in powers of the inverse of the meson mass. The decay constants are calculated with the incorporation of leading order covariants. Most of the results are dramatically improved.Comment: new version of the pape