118384504
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.
54545936
Multirefringence phenomena in nonlinear electrodynamics
Universite´ de Nice Sophia Antipolis, 06103 Nice Cedex 2, Franceand Dipartimento di Fisica and ICRA, Sapienza Universita` di Roma, I-00185 Rome, Italy(Received 19 April 2013; published 13 September 2013)Wave propagation in nonlinear theories of the electromagnetism described by Lagrangian densitiesdependent upon its two local invariants LðF;GÞ is revisited. On the light of the recent ﬁndings inmetamaterials, it is here shown that trirefringence is also a possible phenomenon to occur in the realm ofsuch nonlinear theories. A speciﬁc model exhibiting this effect is investigated in terms of both phase andgroup velocities. It is claimed that wave propagation in some well known nonlinear models for spin-oneﬁelds, like QED and QCD in certain regimes, may exhibit trirefringence.
119531071
Comments on CLEO new measurements for $\upsilon_{1S}$ decays to charmonium final states and investigations on associate strange particle enhancement in $\upsilon$ to J/Psi + $X$
The recent measurements by CLEO Collaboration for the inclusive J/Psi and Psi(2S) production in Upsilon(1S) decay and our previous calculation are analyzed. The J/Psi momentum spectrum and the production ratio of Psi(2S) versus J/Psi favour Upsilon to J/Psi(Psi(2S)) + ccbar g as the dominant contribution. We point out that the differences between the experimental data and our previous results are mainly originated from the setting of the parameter charm quark mass. We further suggest the associate strange particle enhancement as a probe for the open charm particles in Upsilon to J/Psi (Psi(2S)) + ccbar g.
189809274
Dirac structure of quark-hadron vertex in Bethe-Salpeter wave function under the framework covariant instantaneous ansatz
In the framework of covariant instantaneous ansatz, the general form of the quark-hadron vertex of certain kind of mesons is provided; how to arrange the Dirac covariants of the complete set by the power counting rule is discussed. Employing the leading order Dirac covariants for vector and pseudoscalar mesons, their decay constants are calculated. This proceeding paper is complementary to our other two previous papers, emphasizing on some conceptual discussions. The strong interaction is special for its basic degree of freedoms are confined in hadrons, preventing the measurement of the “really-free” quanta, i.e., quarks and gluons in quantum chromodynamics (QCD). Hence, a description for the asymptotic states, the hadrons, in the strong interactions/collisions, with the language of the basic quanta/fields, quarks, and gluons, is a necessary but challenging task. In the framework of relativistic quantum field theory, at least one “standard” way to describe bound states, i.e., the Bethe-Salpeter wave function (BSW), which is the solution of the Bethe-Salpeter integral equation (BSE), seems available. Through an extensive employment of various techniques in the quantum field theory, such as the DysonSchwinger Equations, one may expect to know the movement of the quarks and gluons in hadrons, and to calculate various kinds of interactions/collisions in various energy scales with such knowledge. This is one of the most important purposes of studying the hadron structure. However, a full understanding of the physical picture of the BSW and a satisfactory way to solve the BES in QCD are still beyond approach. Even, one is not able to give the “rigorous” form of the kernel of the BSE without practical non-perturbative techniques in QCD. More specifically, one has a very powerful picture/tool in high energy hadronic interactions, i.e., the perturbative QCD inspired parton model, but how to approach this parton picture starting from low energy BSW of hadron is an open question. At the same time, the standard factorization scheme is often facing danger in various special processes [1, 2]. So it is very much justified to put more labour on the study of BSW/BSE, especially their
118901774
Gluon Shadowing and Hadron Production at RHIC
Nuclear Science Division, Mailstop 70-319, Lawrence Berkeley Laboratory, Berkeley, California 94720.(October 3,2001)Hadron multiplicity in the central rapidity region of high-energy heavy-ion collisions is investi-gated within a two-component mini-jet model which consists of soft and semi-hard particle produc-tion. The hard contribution from mini-jets is reevaluated using the latest parameterization of partondistributions and nuclear shadowing. The energy dependence of the experimental data from RHICrequires a strong nuclear shadowing of the gluon distribution in this model. The centrality depen-dence of the hadron multiplicity at√s = 130 GeV is reproduced well with the impact-parameterdependent parton shadowing. However, energy variation of the centrality dependence is needed todistinguish diﬀerent particle production mechanisms such as the parton saturation model.25.75.-q,12.38.Bx,12.38.Mh,24.85.+p
115465221
OPERA Collaboration have observed phase speed of neutrino wave function, while advanced time displacement is mainly due to finite life time of pion
First we call the attention that velocity defined by ratio between some intervals of space and time respectively is sometimes ambiguous, in the framework of quantum theory. Velocity in general is not possible to be well defined as some generator of certain space-time symmetry operation. Then in section 3 by analyzing the OPERA experiment we show that the OPERA Collaboration may have measured the phase speed of the neutrino wave function. Employing a very (maybe too) simple model which is just a reproduction from Brillouin's classical book, we demonstrate the phase velocity and group velocity. These are just a qualitative illustration rather than aiming to quantitively explain the OPERA data. However, how to rigorously define the phase containing the particle production ordering information as a space-time distribution observable in QFT needs more investigations. Due to the finite life time of the pions (w.r.t. its flying time in the 1 km long tunnel) which decay to the muon neutrinos, the wave form for neutrinos recorded by OPERA is deformed from that of the proton. Such an effect is estimated to lead to an advanced time displacement of the order of 100ns, which coincides with the measured. Such an effect can only be significant when measuring phase speed and the recorded neutrino events per extraction of proton smaller than one, as the OPERA case.
120721773
PRELIMINARY COMMISSIONING OF SUPERCONDUCTING MAGNETS AND CRYOGENIC SYSTEM OF BEPC II
A helium cryogenic system with cooling capacity of 1 kW at 4.5 K was set up at Institute of High Energy Physics, Chinese Academy of Sciences, Beijing. This helium refrigerating system is dedicated for the cooling of two superconducting radio frequency (SRF) cavities, two interaction region superconducting collision quadrupole (SCQ) magnets, a detector superconducting solenoid magnet (SSM), which are the key items of the upgrade project of Beijing Electron-Positron Collider (BEPC II). Commissioning with the detector and SCQ magnets was carried out, which will be introduced in this paper. The cryogenic system shows very robust as SSM quench. This paper presents the overall status and some test results of superconducting and cryogenic system.
14118127
The Bifurcation of the Topological Structure in the Sunspot's Electric Topological Current with Locally Gauge-invariant Maxwell-Chern-Simons Term
The topological structure of the electric topological current of the locally gauge invariant Maxwell-Chern-Simons Model and its bifurcation is studied. The electric topological charge is quantized in term of winding number. The Hopf indices and Brouwer degree labeled the local topological structure of the electric topological current. Using Φ-mapping method and implicit function theory, the electric topological current is found generating or annihilating at the limit points and splitting or merging at the bifurcate points. The total electric charge holds invariant during the evolution.
15957415
The topological structure of the space–time disclination
The space–time disclination is studied by making use of the decomposition theory of gauge potential in terms of the antisymmetric tensor field and φ-mapping method. It is shown that the self-dual and anti-self-dual parts of the curvature compose the space–time disclinations which are classified in terms of topological invariants—winding number. The projection of space–time disclination density along an antisymmetric tensor field is quantized topologically and characterized by Brouwer degree and Hopf index.
16179887
First calculation of cosmic-ray muon spallation backgrounds for MeV astrophysical neutrino signals in Super-Kamiokande
signals is much larger than the signal rates for kinetic energies of about 6 { 18 MeV. Surprisingly, there is no published calculation of the production and properties of these backgrounds in water, though there are such studies for scintillator. Using the simulation code FLUKA and theoretical insights, we detail how muons lose energy in water, produce secondary particles, how and where these secondaries produce isotopes, and the properties of the backgrounds from their decays. We reproduce Super-Kamiokande measurements of the total background to within a factor of 2, which is good given that the isotope yields vary by orders of magnitude and that some details of the experiment are unknown to us at this level. Our results break aggregate data into component isotopes, reveal their separate production mechanisms, and preserve correlations between them. We outline how to implement more eective background rejection techniques using this information. Reducing backgrounds in solar and DSNB studies by even a factor of a few could help lead to important new discoveries.
118068874
Topological Defects in 3-d Euclidean Gravity
By making use of the complete decomposition of SO(3) spin connection, the topological defect in 3-dimensional Euclidean gravity is studied in detail. The topological structure of disclination is given as the combination of a monopole structure and a vortex structure. Furthermore, the Kac-Moody algebra generated by the monopole and vortex is discussed in three dimensional Chern-Simons theory.