Oberhauser, B. B., Bisio, P., Celentano, A., Depero, E., Dusaev, R. R., Kirpichnikov, D. V., et al. (2024). Development of the fully Geant4 compatible package for the simulation of Dark Matter in fixed target experiments. Comput. Phys. Commun., 300, 109199–11pp.
Abstract: The search for new comparably light (well below the electroweak scale) feebly interacting particles is an exciting possibility to explain some mysterious phenomena in physics, among them the origin of Dark Matter. The sensitivity study through detailed simulation of projected experiments is a key point in estimating their potential for discovery. Several years ago we created the DMG4 package for the simulation of DM (Dark Matter) particles in fixed target experiments. The natural approach is to integrate this simulation into the same program that performs the full simulation of particles in the experiment setup. The Geant4 toolkit framework was chosen as the most popular and versatile solution nowadays. The simulation of DM particles production by this package accommodates several possible scenarios, employing electron, muon or photon beams and involving various mediators, such as vector, axial vector, scalar, pseudoscalar, or spin 2 particles. The bremsstrahlung, annihilation or Primakoff processes can be simulated. The package DMG4 contains a subpackage DarkMatter with cross section methods weakly connected to Geant4. It can be used in different frameworks. In this paper, we present the latest developments of the package, such as extending the list of possible mediator particle types, refining formulas for the simulation and extending the mediator mass range. The user interface is also made more flexible and convenient. In this work, we also demonstrate the usage of the package, the improvements in the simulation accuracy and some cross check validations. Program summary Program title: DMG4 CPC Library link to program files: https://doi .org /10 .17632 /cmr4bcrj6j .1 Licensing provisions: GNU General Public License 3 Programming language: c++ Journal reference of previous version: Comput. Phys. Commun. 269 (2021) 108129 Does the new version supersede the previous version?: Yes Reasons for the new version: Numerous developments, addition of new features Summary of revisions: WW approximation cross sections for the muon beam are implemented and cross-checked, models with semivisible A ' (inelastic Dark Matter) and spin 2 mediators are added. The range of possible mediator masses is extended. Several important improvements for the annihilation processes are made, the number of possible annihilation processes is extended. User interface is improved. Several bugs are fixed. Nature of problem: For the simulation of Dark Matter production processes in fixed target experiments a code that can be easily integrated in programs for the full simulation of experimental setup is needed. Solution method: A fully Geant4 compatible DM simulation package DMG4 was presented in 2020. We present numerous further developments of this package.
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Catumba, G., Ramos, A., & Zaldivar, B. (2025). Stochastic automatic differentiation for Monte Carlo processes. Comput. Phys. Commun., 307, 109396–13pp.
Abstract: Monte Carlo methods represent a cornerstone of computer science. They allow sampling high dimensional distribution functions in an efficient way. In this paper we consider the extension of Automatic Differentiation (AD) techniques to Monte Carlo processes, addressing the problem of obtaining derivatives (and in general, the Taylor series) of expectation values. Borrowing ideas from the lattice field theory community, we examine two approaches. One is based on reweighting while the other represents an extension of the Hamiltonian approach typically used by the Hybrid Monte Carlo (HMC) and similar algorithms. We show that the Hamiltonian approach can be understood as a change of variables of the reweighting approach, resulting in much reduced variances of the coefficients of the Taylor series. This work opens the door to finding other variance reduction techniques for derivatives of expectation values.
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Bandos, I. A., de Azcarraga, J. A., & Meliveo, C. (2012). Conformal higher spin theory in extended tensorial superspace. Fortschritte Phys.-Prog. Phys., 60(7-8), 861–867.
Abstract: We discuss the formulation of free conformal higher spin theories with extended N = 2, 4, 8 supersymmetry in N-extended tensorial superspaces. The superfield higher spin equations can be obtained by quantizing a superparticle model in N-extended tensorial superspace. The N-extended higher spin supermultiplets just contain scalar and spinor fields in tensorial space so that, in contrast with the standard (super)space approach, no nontrivial generalizations of the Maxwell or Einstein equations to tensorial space appear when N > 2. For N = 4, 8, the higher spin-tensorial components of the extended tensorial superfields are expressed through additional scalar and spinor fields in tensorial space which obey the same free higher spin equations, but that are axion-like in the sense that they possess Peccei-Quinn-like symmetries.
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Cervantes, D., Fioresi, R., Lledo, M. A., & Nadal, F. A. (2012). Quadratic deformation of Minkowski space. Fortschritte Phys.-Prog. Phys., 60(9-10), 970–976.
Abstract: We present a deformation of the Minkowski space as embedded into the conformal space (in the formalism of twistors) based in the quantum versions of the corresponding kinematic groups. We compute explicitly the star product, whose Poisson bracket is quadratic. We show that the star product although defined on the polynomials can be extended differentiably. Finally we compute the Eucliden and Minkowskian real forms of the deformation.
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Galli, P., Ortin, T., Perz, J., & Shahbazi, C. S. (2012). From supersymmetric to non-supersymmetric black holes. Fortschritte Phys.-Prog. Phys., 60(9-10), 1026–1029.
Abstract: Methods similar to those used for obtaining supersymmetric black hole solutions can be employed to find also non-supersymmetric solutions. We briefly review some of them, with the emphasis on the non-extremal deformation ansatz of [1].
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