larsdal

• Athron, Peter; Balázs, Csaba; Dal, Lars Andreas; Edsjö, Joakim; Farmer, Ben & Gonzalo, Tomas Esteban [Vis alle 13 forfattere av denne artikkelen] (2018). SpecBit, DecayBit and PrecisionBit: GAMBIT modules for computing mass spectra, particle decay rates and precision observables. European Physical Journal C. ISSN 1434-6044. 78(1). doi: 10.1140/epjc/s10052-017-5390-8. Fulltekst i vitenarkiv Vis sammendrag

  We present the GAMBIT modules SpecBit, DecayBit and PrecisionBit. Together they provide a new framework for linking publicly available spectrum generators, decay codes and other precision observable calculations in a physically and statistically consistent manner. This allows users to automatically run various combinations of existing codes as if they are a single package. The modular design allows software packages fulfilling the same role to be exchanged freely at runtime, with the results presented in a common format that can easily be passed to downstream dark matter, collider and flavour codes. These modules constitute an essential part of the broader GAMBIT framework, a major new software package for performing global fits. In this paper we present the observable calculations, data, and likelihood functions implemented in the three modules, as well as the conventions and assumptions used in interfacing them with external codes. We also present 3-BIT-HIT, a command-line utility for computing mass spectra, couplings, decays and precision observables in the MSSM, which shows how the three modules can easily be used independently of GAMBIT.

• Athron, Peter; Balázs, Csaba; Bringmann, Torsten; Buckley, Andy; Chrząszcz, Martin & Conrad, Jan [Vis alle 31 forfattere av denne artikkelen] (2017). GAMBIT: The Global and Modular Beyond-the-Standard-Model Inference Tool. European Physical Journal C. ISSN 1434-6044. 77(11), s. 784–784. doi: 10.1140/epjc/s10052-017-5321-8. Fulltekst i vitenarkiv Vis sammendrag

  We describe the open-source global fitting package GAMBIT: the Global And Modular Beyond-the-Standard-Model Inference Tool. GAMBIT combines extensive calculations of observables and likelihoods in particle and astroparticle physics with a hierarchical model database, advanced tools for automatically building analyses of essentially any model, a flexible and powerful system for interfacing to external codes, a suite of different statistical methods and parameter scanning algorithms, and a host of other utilities designed to make scans faster, safer and more easily-extendible than in the past. Here we give a detailed description of the framework, its design and motivation, and the current models and other specific components presently implemented in GAMBIT. Accompanying papers deal with individual modules and present first GAMBIT results. GAMBIT can be downloaded from gambit.hepforge.org

• Bernlochner, Florian U.; Chrząszcz, Marcin; Dal, Lars Andreas; Farmer, Ben; Jackson, Paul & Kvellestad, Anders [Vis alle 13 forfattere av denne artikkelen] (2017). FlavBit: A GAMBIT module for computing flavour observables and likelihoods. European Physical Journal C. ISSN 1434-6044. 77(11), s. 786–786. doi: 10.1140/epjc/s10052-017-5157-2. Fulltekst i vitenarkiv Vis sammendrag

  Flavour physics observables are excellent probes of new physics up to very high energy scales. Here we present FlavBit, the dedicated flavour physics module of the global-fitting package GAMBIT. FlavBit includes custom implementations of various likelihood routines for a wide range of flavour observables, including detailed uncertainties and correlations associated with LHCb measurements of rare, leptonic and semileptonic decays of B and D mesons, kaons and pions. It provides a generalised interface to external theory codes such as SuperIso, allowing users to calculate flavour observables in and beyond the Standard Model, and then test them in detail against all relevant experimental data. We describe FlavBit and its constituent physics in some detail, then give examples from supersymmetry and effective field theory illustrating how it can be used both as a standalone library for flavour physics, and within GAMBIT.

• Balázs, Csaba; Buckley, Andy; Dal, Lars Andreas; Farmer, Ben; Jackson, Paul & Krislock, Abram Michael Beauregard [Vis alle 15 forfattere av denne artikkelen] (2017). ColliderBit: a GAMBIT module for the calculation of high-energy collider observables and likelihoods. European Physical Journal C. ISSN 1434-6044. 77(11), s. 795–795. doi: 10.1140/epjc/s10052-017-5285-8. Fulltekst i vitenarkiv Vis sammendrag

  We describe ColliderBit, a new code for the calculation of high energy collider observables in theories of physics beyond the Standard Model (BSM). ColliderBit features a generic interface to BSM models, a unique parallelised Monte Carlo event generation scheme suitable for large-scale supercomputer applications, and a number of LHC analyses, covering a reasonable range of the BSM signatures currently sought by ATLAS and CMS. ColliderBit also calculates likelihoods for Higgs sector observables, and LEP searches for BSM particles. These features are provided by a combination of new code unique to ColliderBit, and interfaces to existing state-of-the-art public codes. ColliderBit is both an important part of the GAMBIT framework for BSM inference, and a standalone tool for efficiently applying collider constraints to theories of new physics.

• Athron, Peter; Balázs, Csaba; Bringmann, Torsten; Buckley, Andy; Chrząszcz, Marcin & Conrad, Jan [Vis alle 26 forfattere av denne artikkelen] (2017). Status of the scalar singlet dark matter model. European Physical Journal C. ISSN 1434-6044. 77(8), s. 568–568. doi: 10.1140/epjc/s10052-017-5113-1. Fulltekst i vitenarkiv Vis sammendrag

  One of the simplest viable models for dark matter is an additional neutral scalar, stabilised by a Z2 symmetry. Using the GAMBIT package and combining results from four independent samplers, we present Bayesian and frequentist global fits of this model. We vary the singlet mass and coupling along with 13 nuisance parameters, including nuclear uncertainties relevant for direct detection, the local dark matter density, and selected quark masses and couplings. We include the dark matter relic density measured by Planck, direct searches with LUX, PandaX, SuperCDMS and XENON100, limits on invisible Higgs decays from the Large Hadron Collider, searches for high-energy neutrinos from dark matter annihilation in the Sun with IceCube, and searches for gamma rays from annihilation in dwarf galaxies with the Fermi-LAT. Viable solutions remain at couplings of order unity, for singlet masses between the Higgs mass and about 300 GeV, and at masses above ∼ 1 TeV. Only in the latter case can the scalar singlet constitute all of dark matter. Frequentist analysis shows that the low-mass resonance region, where the singlet is about half the mass of the Higgs, can also account for all of dark matter, and remains viable. However, Bayesian considerations show this region to be rather fine-tuned.

• Athron, Peter; Balázs, Csaba; Bringmann, Torsten; Buckley, Andy; Chrząszcz, Marcin & Conrad, Jan [Vis alle 24 forfattere av denne artikkelen] (2017). A global fit of the MSSM with GAMBIT. European Physical Journal C. ISSN 1434-6044. 77(12), s. 879–879. doi: 10.1140/epjc/s10052-017-5196-8. Fulltekst i vitenarkiv Vis sammendrag

  We study the seven-dimensional Minimal Supersymmetric Standard Model (MSSM7) with the new GAMBIT software framework, with all parameters defined at the weak scale. Our analysis significantly extends previous weak-scale, phenomenological MSSM fits, by adding more and newer experimental analyses, improving the accuracy and detail of theoretical predictions, including dominant uncertainties from the Standard Model, the Galactic dark matter halo and the quark content of the nucleon, and employing novel and highly-efficient statistical sampling methods to scan the parameter space. We find regions of the MSSM7 that exhibit co-annihilation of neutralinos with charginos, stops and sbottoms, as well as models that undergo resonant annihilation via both light and heavy Higgs funnels. We find high-likelihood models with light charginos, stops and sbottoms that have the potential to be within the future reach of the LHC. Large parts of our preferred parameter regions will also be accessible to the next generation of direct and indirect dark matter searches, making prospects for discovery in the near future rather good.

• Bringmann, Torsten; Conrad, Jan; Cornell, Jonathan M.; Dal, Lars Andreas; Edsjö, Joakim & Farmer, Ben [Vis alle 14 forfattere av denne artikkelen] (2017). DarkBit: A GAMBIT module for computing dark matter observables and likelihoods. European Physical Journal C. ISSN 1434-6044. 77(12), s. 831–831. doi: 10.1140/epjc/s10052-017-5155-4. Fulltekst i vitenarkiv Vis sammendrag

  We introduce DarkBit, an advanced software code for computing dark matter constraints on various extensions to the Standard Model of particle physics, comprising both new native code and interfaces to external packages. This release includes a dedicated signal yield calculator for gamma-ray observations, which significantly extends current tools by implementing a cascade-decay Monte Carlo, as well as a dedicated likelihood calculator for current and future experiments (gamLike). This provides a general solution for studying complex particle physics models that predict dark matter annihilation to a multitude of final states. We also supply a direct detection package that models a large range of direct detection experiments (DDCalc), and that provides the corresponding likelihoods for arbitrary combinations of spin-independent and spin-dependent scattering processes. Finally, we provide custom relic density routines along with interfaces to DarkSUSY, micrOMEGAs, and the neutrino telescope likelihood package nulike. DarkBit is written in the framework of the Global And Modular Beyond the Standard Model Inference Tool (GAMBIT), providing seamless integration into a comprehensive statistical fitting framework that allows users to explore new models with both particle and astrophysics constraints, and a consistent treatment of systematic uncertainties. In this paper we describe its main functionality, provide a guide to getting started quickly, and show illustrative examples for results obtained with DarkBit (both as a stand-alone tool and as a GAMBIT module). This includes a quantitative comparison between two of the main dark matter codes (DarkSUSY and micrOMEGAs), and application of DarkBit ’s advanced direct and indirect detection routines to a simple effective dark matter model.

• Athron, Peter; Balázs, Csaba; Bringmann, Torsten; Buckley, Andy; Chrząszcz, Marcin & Conrad, Jan [Vis alle 25 forfattere av denne artikkelen] (2017). Global fits of GUT-scale SUSY models with GAMBIT. European Physical Journal C. ISSN 1434-6044. 77(12), s. 824–824. doi: 10.1140/epjc/s10052-017-5167-0. Fulltekst i vitenarkiv Vis sammendrag

  We present the most comprehensive global fits to date of three supersymmetric models motivated by grand unification: the constrained minimal supersymmetric standard model (CMSSM), and its Non-Universal Higgs Mass generalisations NUHM1 and NUHM2. We include likelihoods from a number of direct and indirect dark matter searches, a large collection of electroweak precision and flavour observables, direct searches for supersymmetry at LEP and Runs I and II of the LHC, and constraints from Higgs observables. Our analysis improves on existing results not only in terms of the number of included observables, but also in the level of detail with which we treat them, our sampling techniques for scanning the parameter space, and our treatment of nuisance parameters. We show that stau co-annihilation is now ruled out in the CMSSM at more than 95% confidence. Stop co-annihilation turns out to be one of the most promising mechanisms for achieving an appropriate relic density of dark matter in all three models, whilst avoiding all other constraints. We find high-likelihood regions of parameter space featuring light stops and charginos, making them potentially detectable in the near future at the LHC. We also show that tonne-scale direct detection will play a largely complementary role, probing large parts of the remaining viable parameter space, including essentially all models with multi-TeV neutralinos.

• Aramaki, T; Boggs, S; Bufalino, S; Dal, Lars Andreas; Doetinchem, Peter von & Donato, Flavio [Vis alle 27 forfattere av denne artikkelen] (2016). Review of the theoretical and experimental status of dark matter identification with cosmic-ray antideuterons. Physics reports. ISSN 0370-1573. 618, s. 1–37. doi: 10.1016/j.physrep.2016.01.002. Fulltekst i vitenarkiv
• Doetinchem, Peter von; Aramaki, T; Boggs, S; Bufalino, S; Dal, Lars Andreas & Donato, F [Vis alle 27 forfattere av denne artikkelen] (2015). Status of cosmic-ray antideuteron searches. Proceedings of Science (PoS). Fulltekst i vitenarkiv
• Dal, Lars Andreas & Raklev, Are (2015). Alternative formation model for antideuterons from dark matter. Physical Review D. ISSN 1550-7998. 91(12). doi: 10.1103/PhysRevD.91.123536. Fulltekst i vitenarkiv Vis sammendrag

  Antideuterons are a potential messenger for dark matter annihilation or decay in our own Galaxy, with very low backgrounds expected from astrophysical processes. The standard coalescence model of antideuteron formation, while simple to implement, is shown to be under considerable strain by recent data from the LHC. We suggest a new empirically based model, with only one free parameter, which is better able to cope with these data, and we explore the consequences of the model for dark matter searches. © 2015 American Physical Society

• Dal, Lars Andreas & Raklev, Are (2014). Antideuteron limits on decaying dark matter with a tuned formation model. Physical Review D. ISSN 1550-7998. 89(10). doi: 10.1103/PhysRevD.89.103504. Fulltekst i vitenarkiv Vis sammendrag

  We investigate the production of antideuterons from decaying dark matter, using gravitinos in supersymmetric models with trilinear R-parity-violating (RPV) operators as an example. The model used for antideuteron formation is shown to induce large uncertainties in the predicted flux, comparable to uncertainties from cosmic-ray propagation models. We improve on the formation model by tuning hadronization and coalescence parameters in Monte Carlo simulations to better reproduce the hadron spectra relevant for antideuteron production. In light of current bounds on fluxes and future prospects from the AMS-02 and GAPS experiments we set limits on RPV couplings as a function of the gravitino mass. © 2014 American Physical Society

• Dal, Lars Andreas & Kachelriess, Michael (2012). Antideuterons from dark matter annihilations and hadronization model dependence. Physical Review D. Particles and fields. ISSN 0556-2821. 86(10). doi: 10.1103/PhysRevD.86.103536. Fulltekst i vitenarkiv Vis sammendrag

  We calculate the antideuteron yield in dark matter annihilations on an event-by-event basis using the herwig++ Monte Carlo generator. We present the resulting antideuteron fluxes for quark and gauge boson final states. As deuteron production in the coalescence model depends on momentum differences between nucleons that are small compared to ΛQCD, it is potentially very sensitive to the hadronization model employed. We therefore compare our antideuteron yields to earlier results based on pythia, thereby estimating their uncertainties. We also briefly discuss the importance of n>2 final states for annihilations of heavy dark matter particles. © 2012 American Physical Society

Se alle arbeider i NVA

• Dal, Lars Andreas (2015). Cosmic Ray Antideuterons from Particle Dark Matter. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  Antideuteron cosmic rays constitute a promising channel for indirect detection of dark matter, and experimental data sensitive to prospective dark matter signals can be expected in the near future. The antideuteron channel has a substantial uncertainty component originating from the theoretical description of antideuteron formation. We here investigate the uncertainty contributions from Monte Carlo hadronization modeling, and explore the prospects of tuning Monte Carlo event generators specifically for antideuteron formation. We further calculate the antideuteron spectra from gravitino decays in supersymmetric models with trilinear R-parity violation (RPV), and estimate the limits on the RPV couplings that can be set by near future experimental data. As an alternative to the established coalescence model of antideuteron formation, we introduce an alternative model based on experimentally measured antideuteron formation cross sections. We find this model to give a more consistent description of experimental antideuteron data, giving a significantly better description of recent data from the ALICE experiment, which the coalescence model fails to reproduce. Many well motivated dark matter models originate from models of new physics with large numbers of free parameters, whose phenomenology can vary drastically across their parameter spaces. In order to identify the model that is in best agreement with current experiments, global fits, taking all relevant data into account, are necessary. A significant part of the work behind this thesis has been contributions to the development of the GAMBIT fitting code; the most significant contribution being the development of a Monte Carlo cascade decay code that will allow cosmic ray data to be included in the fits.

Se alle arbeider i NVA