Model Of Elementary Particle Physics Research Articles

Mass generation via nonlinear massive solution in Higgs potential and particle creations

The nonlinear massive plane wave solution of the classical scalar field in the Higgs potential is revisited to study the mass generation and particle creation. In particular, by assuming that the Higgs system is in the slightly excited state in early universe and it is described by the nonlinear solution, we study the mass generation mechanism for massive vector bosons and a heavy fermion in the quantum field theory around the nonlinear massive classical field. The nonlinear massive classical solution gives the transition from the vacuum to a pair of vector bosons and fermions. We present the new formulae of the probability density of the production process for particles in the standard model of elementary particle physics. The probability densities of the particle productions vanish when the nonlinear massive solution reduces to the constant solution (the classical vacuum expectation value); while the probability densities are expressed as the function of the free parameter in the classical solution in general case. We discuss the behavior of the probability densities for the three oscillating modes in the classical solution.

Study of neutron beta decay with the Nab experiment

The current three sigma tension in the unitarity test of the Cabbibo-Kobayashi-Maskawa (CKM) matrix is a notable problem with the Standard Model of elementary particle physics. A long-standing goal of the study of free neutron beta decay is to better determine the CKM element Vud through measurements of the neutron lifetime and a decay correlation parameter. The Nab collaboration intends to measure a, the neutrino-electron correlation, with accuracy sufficient for a competitive evaluation of Vud based on neutron decay data alone. This paper gives a status report and an outlook.

A portrait of the Higgs boson by the CMS experiment ten years after the discovery

In July 2012, the ATLAS and CMS collaborations at the CERN Large Hadron Collider announced the observation of a Higgs boson at a mass of around 125 gigaelectronvolts. Ten years later, and with the data corresponding to the production of a 30-times larger number of Higgs bosons, we have learnt much more about the properties of the Higgs boson. The CMS experiment has observed the Higgs boson in numerous fermionic and bosonic decay channels, established its spin–parity quantum numbers, determined its mass and measured its production cross-sections in various modes. Here the CMS Collaboration reports the most up-to-date combination of results on the properties of the Higgs boson, including the most stringent limit on the cross-section for the production of a pair of Higgs bosons, on the basis of data from proton–proton collisions at a centre-of-mass energy of 13 teraelectronvolts. Within the uncertainties, all these observations are compatible with the predictions of the standard model of elementary particle physics. Much evidence points to the fact that the standard model is a low-energy approximation of a more comprehensive theory. Several of the standard model issues originate in the sector of Higgs boson physics. An order of magnitude larger number of Higgs bosons, expected to be examined over the next 15 years, will help deepen our understanding of this crucial sector.

Novel constraints on neutrino physics beyond the standard model from the CONUS experiment

The measurements of coherent elastic neutrino-nucleus scattering (CEνNS) experiments have opened up the possibility to constrain neutrino physics beyond the standard model of elementary particle physics. Furthermore, by considering neutrino-electron scattering in the keV-energy region, it is possible to set additional limits on new physics processes. Here, we present constraints that are derived from Conus germanium data on beyond the standard model (BSM) processes like tensor and vector non-standard interactions (NSIs) in the neutrino-quark sector, as well as light vector and scalar mediators. Thanks to the realized low background levels in the Conus experiment at ionization energies below 1 keV, we are able to set the world’s best limits on tensor NSIs from CEνNS and constrain the scale of corresponding new physics to lie above 360 GeV. For vector NSIs, the derived limits strongly depend on the assumed ionization quenching factor within the detector material, since small quenching factors largely suppress potential signals for both, the expected standard model CEνNS process and the vector NSIs. Furthermore, competitive limits on scalar and vector mediators are obtained from the CEνNS channel at reactor-site which allow to probe coupling constants as low as 5 ∙ 10−5 of low mediator masses, assuming the currently favored quenching factor regime. The consideration of neutrino-electron scatterings allows to set even stronger constraints for mediator masses below ∼ 1 MeV and ∼ 10 MeV for scalar and vector mediators, respectively.

The Search for μ+ → e+γ with 10–14 Sensitivity: The Upgrade of the MEG Experiment

The MEG experiment took data at the Paul Scherrer Institute in the years 2009–2013 to test the violation of the lepton flavor conservation law, which originates from an accidental symmetry that the Standard Model of elementary particle physics has, and published the most stringent limit on the charged lepton flavor violating decay μ+→e+γ: BR(μ+→e+γ) <4.2×10−13 at 90% confidence level. The MEG detector has been upgraded in order to reach a sensitivity of 6×10−14. The basic principle of MEG II is to achieve the highest possible sensitivity using the full muon beam intensity at the Paul Scherrer Institute (7×107 muons/s) with an upgraded detector. The main improvements are better rate capability of all sub-detectors and improved resolutions while keeping the same detector concept. In this paper, we present the current status of the preparation, integration and commissioning of the MEG II detector in the recent engineering runs.

Elementary Particles Result from Space-Time Quantization

We justify and extend the standard model of elementary particle physics by generalizing the theory of relativity and quantum mechanics. The usual assumption that space and time are continuous implies, indeed, that it should be possible to measure arbitrarily small intervals of space and time, but we ignore if that is true or not. It is thus more realistic to consider an extremely small “quantum of length” of yet unknown value a. It is only required to be a universal constant for all inertial frames, like c and h. This yields a logically consistent theory and accounts for elementary particles by means of four new quantum numbers. They define “particle states” in terms of modulations of wave functions at the smallest possible scale in space-time. The resulting classification of elementary particles accounts also for dark matter. Antiparticles are redefined, without needing negative energy states and recently observed “anomalies” can be explained.

О творчестве в физике и перспективах коллективной научной работы

Solving many challenges in dealing with complexity requires a collective effort, including in interdisciplinary projects. Two types of problems arise here, one of which is associated with the development of a special methodology and a general interdisciplinary conceptual and functional language of communication between different disciplines, which is facilitated by the use of the languages of mathematics, the systems approach and synergetics, but not only; the second problem of collective creativity is the development of a unified joint style of generating new information, which is largely associated with the implicit knowledge that is born in scientific schools. In this regard, we consider the scientific schools of theoretical physics and large communities of mega-projects and intelligent mega-machines in high-energy physics, primarily using the example of the “Golden Ageˮ of the history of Russian science in the 80s of the last century in Protvino. Their connection with the social climate, political expectations, the worldview of scientists, the formation of a physicist in the process of education and life in a research team is considered. International trends in collective creativity and nation-al features of the existence of scientific schools are discussed in the context of an international mega-project to create a standard model of elementary particle physics. Three types of theorizing are considered, which date back to the creators of modern science, but are reproduced in each era, in each successive international mega-project. They are based on various forms and combinations of the dominance of formal-logical and empirical thinking. The question about the prospects for theoretical research in the digital era of artificial intelligence is raised.

Between Factualism and Substantialism: Structuralism as a Third Way

ABSTRACTAccording to the substantialist, substances should be regarded as the fundamental ontological category. This has been subjected to criticism, recently and notably by Buonomo and Cumpa, drawing on aspects of modern physics. In this vein, I argue that reflection upon the Standard Model of elementary particle physics also undermines the substantialist position. However this does not necessarily clear the way for the factualist. Focusing on Dasgupta’s ‘generalism’ I suggest that although we are not compelled to adopt this stance, it does open the door to the structuralist position that might be viewed as a ‘third way’ between substantialism and factualism.

Massively parallel computation of atmospheric neutrino oscillations on CUDA-enabled accelerators

The computation of neutrino flavor transition amplitudes through inhomogeneous matter is a time-consuming step and thus could benefit from optimization and parallelization. Next to reliable parameter estimation of intrinsic physical quantities such as neutrino masses and mixing angles, these transition amplitudes are important in hypothesis testing of potential extensions of the standard model of elementary particle physics, such as additional neutrino flavors. Hence, fast yet precise implementations are of high importance to research. In the recent past, massively parallel accelerators such as CUDA-enabled GPUs featuring thousands of compute units have been widely adopted due to their superior memory bandwidth, vast compute capability, and highly competitive compute-to-energy ratio in comparison to traditional multi-core architectures with a few tens of monolithic cores. In this paper, we introduce two scalable multi-GPU extensions of common neutrino oscillation frameworks – namely Prob3++ and νSQuIDS –allowing for the acceleration of oscillation dynamics computation by one to three orders-of-magnitude while preserving numerical accuracy. Our software is licensed under LGPLv3 and can be accessed at https://github.com/fkallen/CUDAProb3 and https://github.com/fkallen/CUDAnuSQuIDS. Program summaryProgram Title: CUDAProb3++ and CUDAνSQuIDSProgram Files doi:http://dx.doi.org/10.17632/j54yymmg5h.1Licensing provisions: LGPLv3Programming language: CUDA, C and C++Nature of problem: Fast computation of neutrino oscillation probabilities in inhomogeneous matter using constant-coefficient or variable-coefficient ODE solvers.Solution method: Solving ordinary differential equations on CUDA-enabled GPUs.

COMET, an Experiment to Search for mu-e Conversion in a Nuclear Field

Charged lepton flavor violating (CLFV) process is predicted to be out of experimental reach by the Standard Model of elementary particle physics (SM). However, many models of the new physics beyond the SM predicts that it is just below the current experimental limit. COMET searches for one of the CLFV process, mu-e conversion in a nuclear field, improving the sensitivity by a factor of approximately [Formula: see text] for Phase-I and [Formula: see text] for Phase-II experiment from a past experiment.

Sobre a radiação cósmica de fundo de micro-onda

Neste artigo, procuraremos dar uma pálida ideia para o leitor do que poderia ser a Radiação Cósmica de Fundo de Micro-onda (RCFM) que, segundo o tradicional modelo do “Big Bang”, foi gerada por uma explosão primordial. Com esse objetivo, achamos muito importante apresentarmos um breve resumo histórico de como o Microcosmo, baseado no Modelo Padrão da Física das Partículas Elementares (MPPE), e o Macrocosmo, baseado no Modelo Padrão do Big Bang (MPBB), evoluíram no tempo. Além disso, na parte final do artigo analisaremos os dois processos físicos apresentados na literatura que procuram explicar a RCFM: Bariogênese e Plasma Quark-Glúon.

A White Paper on keV sterile neutrino Dark Matter

We present a comprehensive review of keV-scale sterile neutrino Dark Matter, collecting views and insights from all disciplines involved—cosmology, astrophysics, nuclear, and particle physics—in each case viewed from both theoretical and experimental/observational perspectives. After reviewing the role of active neutrinos in particle physics, astrophysics, and cosmology, we focus on sterile neutrinos in the context of the Dark Matter puzzle. Here, we first review the physics motivation for sterile neutrino Dark Matter, based on challenges and tensions in purely cold Dark Matter scenarios. We then round out the discussion by critically summarizing all known constraints on sterile neutrino Dark Matter arising from astrophysical observations, laboratory experiments, and theoretical considerations. In this context, we provide a balanced discourse on the possibly positive signal from X-ray observations. Another focus of the paper concerns the construction of particle physics models, aiming to explain how sterile neutrinos of keV-scale masses could arise in concrete settings beyond the Standard Model of elementary particle physics. The paper ends with an extensive review of current and future astrophysical and laboratory searches, highlighting new ideas and their experimental challenges, as well as future perspectives for the discovery of sterile neutrinos.

From Space-Time Quantization to Dark Matter

We generalize relativistic quantum mechanics and the Standard Model of elementary particle physics by considering a finite limit for the smallest measurable length. The resulting theory of Space-Time Quantization is logically consistent and accounts for all possible particle states by means of four new quantum numbers. They specify possible variations of wave functions at the smallest possible scale in space and time, while states of motion are defined by their large-scale variations. This theory also provides insight into the nature and properties of dark matter particles. It can facilitate their detection and identification because of a very strict conservation law.

Search for long-lived neutral particles decaying into lepton-jets in 20.3 fb−1proton-proton collisions at √s = 8 TeV with the ATLAS detector

Several models of elementary particle physics beyond the Standard Model, predict the existence of neutral particles that can decay in jets of leptons and light hadrons (lepton-jets). The present contribution collects the results about the lepton-jet search with the ATLAS experiment at the proton-proton LHC collider at √ s = 8 TeV during the entire 2012 data taking (20 fb −1 ). No excess of events have been observed over the expected background and the exclusion limits for two different models, that predict the Higgs boson to decay in lepton-jets, have been computed. A new lepton-jet search is underway for the new LHC era at (√ s = 13 TeV).

Fermion unification model based on the intrinsic SU(8) symmetry of a generalized Dirac equation

A natural generalization of the original Dirac spinor into a multi-component spinor is achieved, which corresponds to the single lepton and the three quarks of the first family of the standard model of elementary particle physics. Different fermions result from similarity transformations of the Dirac equation, but apparently there can be no more fermions according to the maximal multiplicity revealed in this study. Rotations in the fermion state space are achieved by the unitary generators of the U(1) and the SU(3) groups, corresponding to quantum electrodynamics (QED based on electric charge) and chromodynamics (QCD based on colour charge). In addition to hypercharge the dual degree of freedom of hyperspin emerges, which occurs due to the duplicity implied by the two related (Weyl and Dirac) representations of the Dirac equation. This yields the SU(2) symmetry of the weak interaction, which can be married to U(1) to generate the unified electroweak interaction as in the standard model. Therefore, the symmetry group encompassing all the three groups mentioned above is SU(8), which can accommodate and unify the observed eight basic stable fermions.

Status and prospects of the Belle II experiment

Measurements using the Belle detector at the KEKB collider in Japan have achieved important progress in the flavor structure of the Standard Model of elementary particle physics. Both the collider and the detector are being upgraded to the SuperKEKB collider and the Belle II detector to collect about 40 times higher luminosity of the Belle experiment with several improvements in the detector performance. Using the higher statistics, several measurements with precision comparisons to the predictions in the Standard Model will be performed to search for new physics beyond the Standard Model from a wide range of flavor physics channels. This paper describes the physics prospects and collider/detector construction status of the Belle II experiments.

The Higgs Boson, The God Particle, and the Correlation Between Scientific and Religious Narratives

AbstractThe Higgs mechanism – as part of the Standard Model of Elementary Particle Physics – is mostly considered to be a real physical process that brings about the mass of every elementary particle. Recent discussions show that there are alternative interpretations of it, differing from the common one in the spectrum and the features of some specific physical objects. This, in turn, shows that the problem of reference remains unsolved for physical theories: It is not obvious what kind of objects theoretical terms exactly refer to. Given the fact that the reference to the object level is ambiguous even in the natural sciences, what correlations can be established between scientific terms and religious expressions at all? Do ontic ambiguities make the dialogue between science and religion easier or more complicated? This article reflects on these questions by examining the possible significations (and interrelations) of scientific and religious signs in general as well as from the perspective of the individual. I suggest that religious storytelling and ritual practices can establish specific associations between scientific and religious worldviews under certain conditions – without confusing the different world-views conceptually.

Geometric aspects of the holographic duality

We briefly survey results related to applying the AdS/CFT correspondence to N=1 supersymmetric models. These models, on one hand, are closest to realistic models of elementary particle physics and, on the other hand, are amenable to quantitative analysis using the AdS/CFT correspondence. Furthermore, they are related to such remarkable geometric objects as Sasakian manifolds and Ricci-flat cones, on which we particularly focus.

Higgs Models and Other Stories about Mass Generation

The paper studies the topography of the model landscape of the physics in the Higgs sector both within the Standard Model of Elementary Particle Physics (SM) and beyond (BSM) in the months before the discovery of a SM Higgs boson. At first glance, this landscape appears fragmented into a large number of different models and research communities. But it also clusters around certain guiding ideas, among them supersymmetry or dynamical symmetry breaking, in which representative and narrative features of the models are combined. These models do not stand for themselves, waiting to be experimentally confirmed and elevated to the status of theory. Rather do they, quite in the sense advocated by Morgan and Morrison, enjoy a far-reaching autonomy. Typically models in the Higgs sector entertain three types of mediating relationships. First, they mediate between the SM and the data in those instances where the SM contains some uncertainty in the values of its basic parameters. Second, they mediate between BSM physics and the data by instantiating the core ideas behind these often speculative generalizations of the SM as stories—in Hartmann’s sense—that motivate or justify the respective model. Third, the fact that Higgs models within BSM physics reproduce the SM predictions in the low-energy limit functions as a consistency constraint that does not involve any additional autonomy. Due to the second type of mediating relationship, the representative features of Higgs models BSM are complex.

The Jeffreys–Lindley paradox and discovery criteria in high energy physics

The Jeffreys-Lindley paradox displays how the use of a p-value (or number of standard deviations z) in a frequentist hypothesis test can lead to an inference that is radically different from that of a Bayesian hypothesis test in the form advocated by Harold Jeffreys in the 1930s and common today. The setting is the test of a well-specified null hypothesis (such as the Standard Model of elementary particle physics, possibly with "nuisance parameters") versus a composite alternative (such as the Standard Model plus a new force of nature of unknown strength). The p-value, as well as the ratio of the likelihood under the null hypothesis to the maximized likelihood under the alternative, can strongly disfavor the null hypothesis, while the Bayesian posterior probability for the null hypothesis can be arbitrarily large. The academic statistics literature contains many impassioned comments on this paradox, yet there is no consensus either on its relevance to scientific communication or on its correct resolution. The paradox is quite relevant to frontier research in high energy physics. This paper is an attempt to explain the situation to both physicists and statisticians, in the hope that further progress can be made.