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Chang C.-H.,Chongqing University | Chang C.-H.,CCAST World Laboratory | Chang C.-H.,CAS Institute of Theoretical Physics | Wang J.-X.,CAS Institute of High Energy Physics | Wu X.-G.,Chongqing University
Computer Physics Communications | Year: 2010

An upgraded (second) version of the package GENXICC (A Generator for Hadronic Production of the Double Heavy Baryons Ξc c, Ξb c and Ξb b by C.H. Chang, J.X. Wang and X.G. Wu [its first version in: Comput. Phys. Comm. 177 (2007) 467]) is presented. Users, with this version being implemented in PYTHIA and a GNU C compiler, may simulate full events of these processes in various experimental environments conveniently. In comparison with the previous version, in order to implement it in PYTHIA properly, a subprogram for the fragmentation of the produced double heavy diquark to the relevant baryon is supplied and the interface of the generator to PYTHIA is changed accordingly. In the subprogram, with explanation, certain necessary assumptions (approximations) are made in order to conserve the momenta and the QCD 'color' flow for the fragmentation. Program summary: Program title: GENXICC2.0. Catalogue identifier: ADZJ_v2_0. Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADZJ_v2_0.html. Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland. Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html. No. of lines in distributed program, including test data, etc.: 102 482. No. of bytes in distributed program, including test data, etc.: 1 469 519. Distribution format: tar.gz. Programming language: Fortran 77/90. Computer: Any LINUX based on PC with FORTRAN 77 or FORTRAN 90 and GNU C compiler as well. Operating system: Linux. RAM: About 2.0 MByte. Classification: 11.2. Catalogue identifier of previous version: ADZJ_v1_0. Journal reference of previous version: Comput. Phys. Comm. 177 (2007) 467. Does the new version supersede the previous version?: No. Nature of problem: Hadronic production of double heavy baryons Ξc c, Ξb c and Ξb b. Solution method: The code is based on NRQCD framework. With proper options, it can generate weighted and un-weighted events of hadronic double heavy baryon production. When the hadronizations of the produced jets and double heavy diquark are taken into account in the production, the upgraded version with proper interface to PYTHIA can generate full events. Reasons for new version: Responding to the feedback from users, we improve the generator mainly by carefully completing the 'final non-perturbative process', i.e. the formulation of the double heavy baryon from relevant intermediate diquark. In the present version, the information for fragmentation about momentum-flow and the color-flow, that is necessary for PYTHIA to generate full events, is retained although reasonable approximations are made. In comparison with the original version, the upgraded one can implement it in PYTHIA properly to do the full event simulation of the double heavy baryon production. Summary of revisions: 1.We try to explain the treatment of the momentum distribution of the process more clearly than the original version, and show how the final baryon is generated through the typical intermediate diquark precisely.2.We present color flow of the involved processes precisely and the corresponding changes for the program are made.3.The corresponding changes of the program are explained in the paper. Restrictions: The color flow, particularly, in the piece of code programming of the fragmentation from the produced colorful double heavy diquark into a relevant double heavy baryon, is treated carefully so as to implement it in PYTHIA properly. Running time: It depends on which option is chosen to configure PYTHIA when generating full events and also on which mechanism is chosen to generate the events. Typically, for the most complicated case with gluon-gluon fusion mechanism to generate the mixed events via the intermediate diquark in (c c) [3S1]3 and (c c) [1S0]6 states, under the option, IDWTUP = 1, to generate 1000 events, takes about 20 hours on a 1.8 GHz Intel P4-processor machine, whereas under the option, IDWTUP = 3, even to generate 106 events takes about 40 minutes on the same machine. © 2010 Elsevier B.V. All rights reserved. Source

Hu B.-L.,Huaiyin Normal University | Zhan Y.-B.,Huaiyin Normal University | Zhan Y.-B.,CCAST World Laboratory
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

We propose a scheme of generating four-qubit hyperentangled states between a pair of remote noninteracting atomic ions with a Λ configuration that are confined in Paul traps. These hyperentangled states, different from the normal entangled states that are entangled in a single degree of freedom, are entangled in both spin and motion degrees of freedom. In our proposal, the entanglement is first generated in spin degrees of freedom using linear optics and then transferred to the motion degree of freedom using a sequence of laser pluses, including the stimulated Raman carrier transitions and sideband transitions. The proposal is completed with regenerating entanglement in spin degrees of freedom using linear optics. © 2010 The American Physical Society. Source

Zheng X.-C.,CAS Institute of Theoretical Physics | Chang C.-H.,CAS Institute of Theoretical Physics | Chang C.-H.,CCAST World Laboratory | Pan Z.,CAS Institute of Theoretical Physics
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2016

Production of the doubly heavy-flavored hadrons (Bc meson, doubly heavy baryons Ξcc, Ξbc, Ξbb, their excited states, and antiparticles of them as well) at e+e- colliders is investigated under two different approaches: LO (leading-order QCD complete calculation) and LL (leading-logarithm fragmentation calculation). The results for the production obtained by the LO and LL approaches, including the angle distributions of the produced hadrons with unpolarized and polarized incoming beams, the behaviors on the energy fraction of the produced doubly heavy-flavored hadron, and comparisons of results between the two approaches, are presented in tables and figures. Thus, characteristics of the production and uncertainties of the approaches are shown precisely, and it is concluded that only if the colliders run at the energies around the Z pole (which may be called the Z factories) and the luminosity of the colliders is as high as possible is the study of the doubly heavy-flavored hadrons completely accessible. © 2016 American Physical Society. Source

Zhou B.-H.,Beijing University of Technology | Huang Y.-C.,Beijing University of Technology | Huang Y.-C.,CAS Institute of Theoretical Physics | Huang Y.-C.,CCAST World Laboratory
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011

We discover an inner structure of QED while the gauge potential is decomposed into two orthogonal components. Based on this, the Lagrangian of the electron-photon system is expanded to a new form and by the general method of field theory, the gauge invariant spin and orbital angular momentum operators of the electron and photon are naturally obtained from Noether's theorem. Our method, which can be generalized to the non-Abelian systems to investigate the inner structure of QCD, provides a new perspective to look on the nucleon spin crisis and opens a window into a strict and systematic resolution of this long-standing problem. © 2011 American Physical Society. Source

Wasay Abdul M.,Beijing University of Technology | Huang Y.-C.,Beijing University of Technology | Huang Y.-C.,CCAST World Laboratory | Zeng D.-F.,Beijing University of Technology | Zeng D.-F.,CAS Institute of Theoretical Physics
Nuclear Physics B | Year: 2015

We give the quantization and spectrum of an RNS supersymmetric open 2-brane described by a Polyakov-like action, the model is world-volume supersymmetric. We present the Hamiltonian of the system in terms of raising and lowering operators. We get a supersymmetric spectrum of excited states in a discrete form after a GSO-like projection, which may be useful for further exploration related to the continuous spectrum of supermembranes. © 2015 The Authors. Source

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