The success of particle detection in high energy physics colliders critically depends on the criteria for selecting a small number of interactions from an overwhelming number that occur in the detector. It also depends on the selection of the exact data to be analyzed and the techniques of analysis. The introduction of automation into the detection process has traded the direct involvement of the physicist at each stage of selection and analysis for the efficient handling of vast amounts (...) of data. This tradeoff, in combination with the organizational changes in laboratories of increasing size and complexity, has resulted in automated and semi-automated systems of detection. Various aspects of the semi-automated regime were greatly diminished in more generic automated systems, but turned out to be essential to a number of surprising discoveries of anomalous processes that led to theoretical breakthroughs, notably the establishment of the Standard Model of particle physics. The automated systems are much more efficient in confirming specific hypothesis in narrow energy domains than in performing broad exploratory searches. Thus, in the main, detection processes relying excessively on automation are more likely to miss potential anomalies and impede potential theoretical advances. I suggest that putting substantially more effort into the study of electron–positron colliders and increasing its funding could minimize the likelihood of missing potential anomalies, because detection in such an environment can be handled by the semi-automated regime—unlike detection in hadron colliders. Despite virtually unavoidable excessive reliance on automated detection in hadron colliders, their development has been deemed a priority because they can operate at currently highest energy levels. I suggest, however, that a focus on collisions at the highest achievable energy levels diverts funds from searches for potential anomalies overlooked due to tradeoffs at the previous energy thresholds. I also note that even in the same collision environment, different research strategies will opt for different tradeoffs and thus achieve different experimental outcomes. Finally, I briefly discuss current searches for anomalous process in the context of the previous analysis. (shrink)

In response to Stephen Davis’s criticism of our previous essay, we revisit and defend our arguments that the Resurrection hypothesis is logically incompatible with the Standard Model of particle physics—and thus is maximally implausible—and that it cannot explain the sensory experiences of the Risen Jesus attributed to various witnesses in the New Testament—and thus has low explanatory power. We also review Davis’s reply, noting that he evades our arguments, misstates their conclusions, and distracts the reader with (...) irrelevancies regarding, e.g., what natural laws are, what a miracle is, and how “naturalism” and “supernaturalism” differ as worldviews. Contrary to what Davis claims (even in his abstract), we do not argue that “if the Standard Model of particle physics is true, then the resurrection of Jesus did not occur and physical things can only causally interact with other physical things.” Davis distorts our claims and criticizes straw men of his own creation. (shrink)

This book develops new forms of logic: Operator Logic, Probabilistic Operator Logic and Quantum Operator Logic. It then proceeds to create a new view of metaphysics, Relativistic Quantum Metaphysics, for physical Reality. It then derives the form of The Standard Model of Elementary Particles. In particular it derives the origin of parity violation, the origin of the Strong interactions, and the origin of its peculiar symmetry. Also developed are new formalisms for Logic that are of interest in themselves. (...) While mathematics is essential in the latter stages of the book it is presented with sufficient text discussion to make what it is doing understandable to the non-mathematical reader. Generally the jargon of Philosophy, Logic and Physics is avoided as much as possible. But the second part of this book is very mathematical of necessity. In it the form of The Standard Model is derived in detail from a fundamental set of principles. (shrink)

According to structural realism, in mature science there is structural continuity along theoretical change. A major counterexample to this thesis is the transition from the Eightfold Way to the Standard Model in particle physics. Nevertheless, the notion of structure is significantly important in comprehending the theoretical picture of particle physics, where particles change and undergo transmutations, while the only thing which remains unchanged is the basic structure, i.e. the symmetry group which controls the transmutations. (...) This kind of view agrees with the paradigmatic case where the structure is an internal symmetry and the instantiations are the elementary particles. The metaphysical view which reflects this situation is a version of ontic structuralism. (shrink)

Much debate about scientific realism concerns the issue of whether it is compatible with theory change over time. Certain forms of ‘selective realism’ have been suggested with this in mind. Here I consider a closely related challenge for realism: that of articulating how a theory should be interpreted at any given time. In a crucial respect the challenges posed by diachronic and synchronic interpretation are the same; in both cases, realists face an apparent dilemma. The thinner their interpretations, the easier (...) realism is to defend, but at the cost of more substantial commitment. The more substantial their interpretations, the more difficult they are to defend. I consider this worry in the context of the Standard Model of particle physics. Examining some selective realist attempts at interpretation, I argue that realism is, in fact, compatible with different commitments on the spectrum of thinner to more substantial, thus mitigating the dilemma. (shrink)

This thesis studies collider phenomenology of physics beyond the Standard Model at the Large Hadron Collider (LHC). It also explores in detail advanced topics related to Higgs boson and supersymmetry - one of the most exciting and well-motivated streams in particle physics. In particular, it finds a very large enhancement of multiple Higgs boson production in vector-boson scattering when Higgs couplings to gauge bosons differ from those predicted by the Standard Model. The thesis (...) demonstrates that due to the loss of unitarity, the very large enhancement for triple Higgs boson production takes place. This is a truly novel finding. The thesis also studies the effects of supersymmetric partners of top and bottom quarks on the Higgs production and decay at the LHC, pointing for the first time to non-universal alterations for two main production processes of the Higgs boson at the LHC-vector boson fusion and gluon-gluon fusion. Continuing the exploration of Higgs boson and supersymmetry at the LHC, the thesis extends existing experimental analysis and shows that for a single decay channel the mass of the top quark superpartner below 175 GeV can be completely excluded, which in turn excludes electroweak baryogenesis in the Minimal Supersymmetric Model. This is a major new finding for the HEP community. This thesis is very clearly written and the introduction and conclusions are accessible to a wide spectrum of readers. (shrink)

In this work we discuss issues of ontological commitment towards one of the most important examples of contemporary fundamental science: the standard model of particle physics. We present a new form of selective structural realism, which uses as its basis the distinction between what have been called framework and interaction theories. This allows us to advance the ongoing debate about the ontological status of (quasi-)particles and quantum fields, by emphasising the distinction between quantum field theory serving (...) as a framework, and the standard model itself, which we argue is an interaction theory embedded within this framework. Following a discussion of what ontological commitments corresponds to each of these two classes, we argue that some of the previous proposals in the literature might have been misguided by the blending of quantum field theory and the standard model into an undifferentiated unity, and defend a moderate form of object realism with respect to particle-like entities. (shrink)

The article соnsiders the socio-cultural aspects of the standard model (SM) in elementary particle physics and history of its creation. SM is a quantum field gauge theory of electromagnetic, weak and strong interactions, which is the basis of the modern theory of elementary particles. The process of its elaboration covers a twenty-year period: from 1954 (the concept of gauge fields by C. Yang and R. Mills) to the early 1970s., when the construction of renormalized quantum chromodynamics (...) and electroweak theory wеre completed. The socio-cultural aspects of SM are explored on the basis of a quasi-empirical approach, by studying the texts of its creators and participants in the relevant events. We note also the important role of such an “external” factor as large-scale state projects on the creation of nuclear and thermonuclear weapons, which provided personnel and financial support for fundamental research in the field of nuclear physics and elementary particle physics (the implementation of thermonuclear projects took place just in the 1950s, and most of the theorists associated with the creation of SM were simultaneously the main developers of thermonuclear weapons, especially in the USSR). The formation of SM is considered as a competition between two research programs (paradigms) – gauge-field and phenomenological, associated with the rejection of the field concept. The split of the scientific community of physicists associated with this competition is going on during this period. It’s accompanied by a kind of “negotiations”, which in the early 1970s lead to the triumph of the gauge field program and the restoration of the unity of the scientific community. The norms and rules of the scientific ethos played the regulatory role in this process. The scientific-realistic position of the metaphysical attitudes of the majority of theorists and their negative attitude to the concepts of philosophical relativism and social construction of scientific knowledge are emphasized. Some features of the history of SM creation are also noted, such as the positive role of aesthetic judgments; “scientific-school” form of research (in the USSR), its pros and cons; a connection to historical-scientific “drama of ideas” with “dramas of people” who made a wrong choice and (or) “missed their opportunities”. (shrink)

The operation of fundamental forces in quantum field theory is explicated here as the exchange of particles, consistently with the standard methodology of particle physics. The particles involved are seen to bear little relation to any classical particle but, rather, comprise unified collections of compresent, conserved quantities indicated by propagators. The exchange particles, which supervene upon quantum fields, are neither more fundamental than fields nor replace them as has often previously been assumed in models of exchange (...) forces. It is argued that this explication of quantum field-theoretic exchange forces definitively improves upon its predecessors. (shrink)

Although the Standard Model of particle physics is usually formulated in terms of fields, it can be equivalently formulated in terms of particles and strings. In this picture particles and open strings are always coupled. This offers an intuitive and graphical explanation for the otherwise mysterious gauge symmetry. In addition, the particle–string formulation avoids introducing redundant path integral configurations that are present in the field formulation. For its explanatory power and economy, the particle–string ontology (...) may be preferred over the field ontology for the Standard Model. (shrink)

This thesis provides an introduction to the physics of the Standard Model and beyond, and to the methods used to analyse Large Hadron Collider (LHC) data. The 'hierarchy problem', astrophysical data and experiments on neutrinos indicate that new physics can be expected at the now accessible TeV scale. This work investigates extensions of the Standard Model with gravitons and gravitinos (in the context of supergravity). The production of these particles in association with jets is (...) studied as one of the most promising avenues for researching new physics at the LHC. Advanced simulation techniques and tools, such as algorithms allowing the computation of Feynman graphs and helicity amplitudes are first developed and then employed. (shrink)

This new edition of work that has evolved over the past seven years completes the derivation of the form of The Standard Model from quantum theory and the extension of the Theory of Relativity to superluminal transformations. The much derided form of The Standard Model is established from a consideration of Lorentz and superluminal relativistic space-time transformations. So much so that other approaches to elementary particle theory pale in comparison. In previous work color SU(3) was (...) derived from space-time considerations. This book shows that the SU(2) U(1) Weak Interaction sector follows directly from the extension of Lorentz transformations to superluminal (faster-than-light) transformations. In fact, ElectroWeak symmetry is shown to have an SU(2) U(1) U(1) symmetry that naturally includes WIMPs (Weakly Interacting Massive Particles), a candidate for Dark Matter. Thus the form of the Standard Model is dictated by space-time considerations fulfilling a dream of Einstein. Using a new matrix formulation of Logic - Operator Logic - we show that Dirac-like equations can be constructed. This edition also derives broken SU(4) four fermion generations as well as a non-Higgsian (Dimensional Mass Generation) derivation of fermion and ElectroWeak gauge boson masses from GL(4). The program of the book is completed by reprinting the book Quantum Theory of the Third Kind, which describes Two-Tier quantum field theory. This theory yields finite results (No Feynman diagram calculations diverge!) in The Standard Model and Quantum Gravity calculations to all orders in perturbation theory. Lastly, the book also contains a description of Operator Logic, Probabilistic Operator Logic, Quantum Operator Logic (for q-number statements). A comprehensive derivation of the form of The Standard Model from geometric considerations. (shrink)

Experiments in particle physics have hitherto failed to produce any significant evidence for the many explicit models of physics beyond the Standard Model (BSM) that had been proposed over the past decades. As a result, physicists have increasingly turned to model-independent strategies as tools in searching for a wide range of possible BSM effects. In this paper, we describe the Standard Model Effective Field Theory (SM-EFT) and analyse it in the context of (...) the philosophical discussions about models, theories, and (bottom-up) effective field theories. We find that while the SM-EFT is a quantum field theory, assisting experimentalists in searching for deviations from the SM, in its general form it lacks some of the characteristic features of models. Those features only come into play if put in by hand or prompted by empirical evidence for deviations. Employing different philosophical approaches to models, we argue that the case study suggests not to take a view on models that is overly permissive because it blurs the lines between the different stages of the SM-EFT research strategies and glosses over particle physicists' motivations for undertaking this bottom-up approach in the first place. Looking at EFTs from the perspective of modelling does not require taking a stance on some specific brand of realism or taking sides in the debate between reduction and emergence into which EFTs have recently been embedded. (shrink)

The extremely successful _Standard Model of Particle Physics_ allows one to define the so-called _Elementary Particles_. From another point of view, how can we think of them? What kind of a status can be attributed to Elementary Particles and their associated quantised fields? Beyond the unprecedented efficiency and reach of quantum field theories, the current paper attempts at understanding the nature of what these theories describe, the enigmatic reality of the quantum world.

Our paper studies the anatomy of the discovery of the Higgs boson at the Large Hadron Collider and its influence on the broader model landscape of particle physics. We investigate the phases of this discovery, which led to a crucial reconfiguration of the model landscape of elementary particle physics and eventually to a confirmation of the standard model. A keyword search of preprints covering the electroweak symmetry breaking sector of particle (...) class='Hi'>physics, along with an examination of physicists own understanding of the discovery as documented in semiannual conferences, has allowed us an empirical investigation of its model dynamics. From our analyses we draw two main philosophical lessons concerning the nature of scientific reasoning in a complex experimental and theoretical environment. For one, from a confirmation standpoint, some SM alternatives could be considered even more confirmed by the Higgs discovery than the SM. Nevertheless, the SM largely remains the commonly accepted account of EWSB. We present criteria for comparing degrees of confirmation and expose some limits of a purely logical approach to understanding the Higgs discovery as a victory for the SM. Second, we understand the persistence of SM alternatives in the face of disfavourable evidence by borrowing the Lakatosian concept of a research programme, where the core idea behind a group of models survives, while other aspects adapt to incoming data. In order to apply this framework to the model landscape of EWSB, we must introduce a new category of research programme, the model-group, and we test its viability using the example of composite Higgs models. (shrink)

Although many find it hard to believe that every physical thing—no matter how simple or small—involves some form of consciousness, panpsychists offer the reassurance that their claims are perfectly compatible with everything physics has to say about the physical world. This is because although physics has a lot to say about causal and structural properties it has nothing to say about the intrinsic natures of physical things, and if physics is silent in this regard it is perfectly (...) possible that everything physical has an experiential intrinsic nature. Following in Thomas Nagel’s footsteps, panpsychists have also argued that by revealing that everything is composed of the same fundamental ingredients, physics provides grounds for holding that if any physical things (e.g. our neural processes) have an experiential intrinsic nature then all must. My main contention in this paper is that the relationship between physics and panpsychism is considerably more complex than panpsychists have tended to assume. Nagel’s reasoning may be sound in the context of simplistic atomic theories which posit just one kind of fundamental particle. However, it begins to look distinctly dubious in the context of the diverse range of primitive entities that are to be found in the Standard Model of particle physics. Galen Strawson has suggested that mass-energy interconvertibility should be regarded as evidence that everything physical has the same intrinsic nature. I suggest Strawson’s claim relies on a dubious construal of the nature of energy. Special relativity is another of the cornerstones of contemporary physics, and it too makes life difficult for panpsychists, a fact which emerges when we consider what it would like to be a ray of light. However in this case I suggest that there is an interesting—if radical—move open to the panpsychist: they can simply deny that light exists. To conclude I briefly consider whether what QCD has revealed about the nature of mass poses a problem for panpsychism. (shrink)

Physicists use different theories to describe the world on different scales. In particular, they use the standard model of particle physics at very high energies, but move to various effective field theories, such as quantum electrodynamics, when modelling lower energy scattering processes. One way to explain this methodological fact is pragmatic in spirit. According to this view, physicists move to an effective field theory at lower energies in order to extract predictions and qualitative understanding which would (...) be difficult or impossible to extract directly from a more fundamental theory. By contrast, another way of accounting for the methodological data is metaphysical in spirit. On this view, the reason that physicists use different theories at different scales is that the world actually exhibits different nomic structure on different scales. These two positions have recently been thrown into sharp relief in a debate between Woodward (2016) and Batterman (2021), with Woodward taking the pragmatist line and Batterman the metaphysical line. One difficulty with the metaphysical answer is that its content is unclear: in what sense exactly could an effective field theory provide a better representation of the nomic structure of the world in its domain of applicability than our world’s fundamental theory? This talk attempts to provide an answer to this question by developing a simple metaphysical model. I start by assuming a set of possible worlds which are nomically possible according to some fundamental theory (I suggest that one is free to adopt either a Humean or Non-Humean view of these fundamental nomic necessities). I then introduce an equivalence relation between possible worlds: two worlds are scale-E equivalent if they assign the same values to physical quantities below energy scale E (up to some finite level of precision P). The key question now is whether this relation induces equivalence classes on the set of nomically possible worlds. I argue that in the case of current quantum field theories this does indeed occur, as evidenced by the possibility of “integrating out” high energy degrees of freedom in the renormalisation group framework. The formation of equivalence classes in the fundamental theory's possibility space indicates that some of its high energy features do not make a difference to its low energy dynamical behaviour. This suggests the following reading of the claim that an effective field theory provides a better representation of the nomic structure of the world in its domain of applicability: the solutions of the effective field theory stand in one-to-one correspondence with equivalence classes induced by the scale-E equivalence relation, whereas the fundamental theory overcounts the physical possibilities which are relevant at scale E. In this sense, the effective field theory provides a more natural representation of low energy physics than the fundamental theory. I conclude by explaining how this metaphysical model offers a reduction compatible understanding of multiple realisability, once again pointing to renormalisation group results in quantum field theory to support this. (shrink)

The theoretical description of particle decay by a single particle theory requires the use of a probability density in time that is not present in conventional theories. The problem of single particle decay is consistently described here within the context of a single particle, relativistic dynamical theory. We derive experimentally testable differences between the standard model and Relativistic Dynamics for a two-state system: the neutral K-meson (K 0) system. We show that the estimate of (...) mass difference between the two states is theory dependent. (shrink)

Studying astroparticle physics sheds new light on scientific explanation and on the ways in which cosmology is empirically underdetermined or not. Astroparticle physics extends the empirical domain of cosmology from purely astronomical data to “multi-messenger astrophysics”, i.e., measurements of all kinds of cosmic rays including very high energetic gamma rays, neutrinos, and charged particles. My paper investigates the ways in which these measurements contribute to cosmology and compares them with philosophical views about scientific explanation, the relation between theory (...) and data, and scientific realism. The “standard models” of cosmology and particle physics lack of unified foundations. Both are “piecemeal physics” in Cartwright's sense, but contrary to her metaphysics of a “dappled world” the work in both fields of research aims at unification. Cosmology proceeds “top-down”, from models to data and from large scale to small-scale structures of the universe. Astroparticle physics proceeds “bottom-up”, from data taking to models and from subatomic particles to large-scale structures of the universe. In order to reconstruct the causal stories of cosmic rays and the nature of their sources, several pragmatic unifying strategies are employed. Standard views about scientific explanation and scientific realism do not cope with these “bottom-up” strategies and the way in which they contribute to cosmology. In addition it has to be noted that the shift to “multi-messenger astrophysics” transforms the relation between cosmological theory and astrophysical data in a mutually holistic way. (shrink)

In a recent book, Anjan Chakravartty builds a case for a particular conception of the relationship of science to metaphysics. The main novel feature in his account of scientific ontology is his construction of a metaphysical distance measure. Some ontological claims are close to the science that informs those claims, and some are further away. The distance is a measure of the epistemic risk one takes in asserting the claim: the further from the empirical base, the greater the risk. But (...) conversely, claims far from the empirical base can serve explanatory and unificatory purposes regarding claims closer in. Since different philosophers have different attitudes towards epistemic risk, Chakravartty endorses a pluralism about scientific ontology. Chakravartty illustrates his arguments concerning scientific ontology by considering what we can infer from the Standard Model of particle physics concerning the ontological status of the structures and entities it describes. I argue that, while this case study initially appears to support Chakravartty’s arguments, on closer inspection it suggests a more deflationary approach to scientific ontology. (shrink)

But the question raised repeatedly in the news media was: What difference does it make? Who cares if the Top mass is 180 GeV or 120 GeV? What possible effect could it have on the "real world" of Medicare and rock stars and ethnic cleansing and Superbowls and insider trading? In this column we will present some ideas from a colloquium given recently at the University of Washington by Dr. Robert N. Cahn of Lawrence Berkeley National Laboratory which address these (...) questions. We'll start by considering the Standard Model of particle physics. (shrink)

An analysis is presented of the possible existence of the second anomalous dipole moment of Dirac’s particle next to the one associated with the angular momentum. It includes a discussion why, in spite of his own derivation, Dirac has doubted about its relevancy. It is shown why since then it has been overlooked and why it has vanished from leading textbooks. A critical survey is given on the reasons of its reject, including the failure of attempts to measure and (...) the perceived violations of time reversal symmetry and charge–parity symmetry. It is emphasized that the anomalous electric dipole moment of the pointlike electron is fundamentally different from the quantum field type electric dipole moment of an electron as defined in the standard model of particle physics. The analysis has resulted into the identification of a third type Dirac particle, next to the electron type and the Majorana particle. It is shown that, unlike as in the case of the electron type, its second anomalous dipole moment is real valued and is therefore subject to polarization in a scalar potential field. Examples are given that it may have a possible impact in the nuclear domain and in the gravitational domain. (shrink)

The Higgs particle has been detected a few years ago, that is what newspapers tell us. For many physicists, the Standard Model of particle physics has accomplished all the jobs. Or to put it simply: The game is over. Is it true? Then some physicists began to ask: can go beyond the Standard Model? Because the supersymmetric extension of the Standard Model has failed. If you feel that theoretical physics is (...) becoming boring, you are not alone. Fortunately, there is good news: a new generation of physicists are doing table-top experiments in their basements. Can we expect new results later? If so, what will the future of physics look like? This article discusses this question, starting with a blunt look at the relationship between mathematics and physical reality, written from the perspectives of a mathematician and a cosmologist. (shrink)

This book is the first to offer a systematic account of the role of language in the development and interpretation of physics. An historical-conceptual analysis of the co-evolution of physics and mathematics leads to the classical/quantum interface. Bohr's interpretation is analyzed and extended to the interpretation of the standard model of particle physics.

This paper criticizes the traditional philosophical account of the quantization of gauge theories and offers an alternative. On the received view, gauge theories resist quantization because they feature distinct mathematical representatives of the same physical state of affairs. This resistance is overcome by a sequence of ad hoc modifications, justified in part by reference to semiclassical electrodynamics. Among other things, these modifications introduce "ghosts": particles with unphysical properties which do not appear in asymptotic states and which are said to be (...) purely a notational convenience. I argue that this sequence of modifications is unjustified and inadequate, making it a poor basis for the interpretation of ghosts. I then argue that gauge theories can be quantized by the same method as any other theory. On this account, ghosts are not purely notation: they are coordinates on the classical configuration space of the theory—specifically, on its gauge structure. This interpretation does not fall prey to the standard philosophical arguments against the significance of ghosts, due to Weingard. Weingard’s argumentative strategy, properly applied, in fact tells in favor of ghosts’ physical significance. (shrink)

A lot of attention has been devoted to the study of discoveries in high energy physics, but less on measurements aiming at improving an existing theory like the standard model of particle physics, getting more precise values for the parameters of the theory or establishing relationships between them. This paper provides a detailed and critical study of how measurements are performed in recent HEP experiments, taking examples from differential cross section measurements with the ATLAS detector (...) at the LHC. This study will be used to provide an elucidation of the concept of event used in HEP, in order to determine what constitutes an observation and what does not. It will highlight the essential place taken by theory-ladenness in order to produce observational facts, and will show how uncertainty and sensitivity estimates constitute an operational approach to robustness, inside the practice of science, avoiding potential circularity problem traditionally implied by theory-ladenness. This is in contrast to robustness analyses typically considered in the literature. A careful analysis of systematic uncertainty estimates and of statistical tests used to set empirical conclusions from the observations will however demonstrate that quantitative statements obtained from these statistical tests cannot be more than simple guiding arguments for the production of knowledge, but do not determine it. This indicates that the frontier between theory and observation is blurry and that the dichotomy theory-experiment should be revised. (shrink)

This second volume is a continuation of the first volume’s 20th century conceptual foundations of quantum physics extending its view to the principles and research fields of the 21st century. A summary of the standard concepts, from modern advanced experimental tests of 'quantum ontology’ to the interpretations of quantum mechanics, the standard model of particle physics, and the mainstream quantum gravity theories. A state-of-the-art treatise that reports on the recent developments in quantum computing, classical (...) and quantum information theory, the black holes information paradox and the holographic principle to quantum cosmology, with some attention on contemporary themes such as the Bose-Einstein condensates as also to the more speculative areas of quantum biology and quantum consciousness. A final chapter on the connections between the quantum realm and philosophical idealism concludes this volume. Considering how the media (sometimes also physicists) present quantum theory, which focuses only on highly dubious ideas and speculations backed by no evidence or, worse, promote pseudo-scientific hypes that fall regularly in and out of fashion, this is a ‘vademecum’ for those who look for a serious introduction and deeper understanding of the 21st century quantum theory. All topics are explained with a concise but rigorous intermediate level style which may, at times, require some effort. However, you will finally acquire an unparalleled background in the conceptual foundations of quantum physics, enabling you to distinguish between the real science backed by experimental facts and mere speculative interpretations. (shrink)

In the asymptotic safety paradigm, a quantum field theory reaches a regime with quantum scale invariance in the ultraviolet, which is described by an interacting fixed point of the Renormalization Group. Compelling hints for the viability of asymptotic safety in quantum gravity exist, mainly obtained from applications of the functional Renormalization Group. The impact of asymptotically safe quantum fluctuations of gravity at and beyond the Planck scale could at the same time induce an ultraviolet completion for the Standard (...) class='Hi'>Model of particle physics with high predictive power. (shrink)

Science is at a cross-roads. For several decades, the Standard Model of particle physics has managed to fit vast amounts of particle scattering data remarkably well, but many questions remain. During those decades, some sophisticated theoretical hypotheses such as string theory, quantum gravity, and quantum cosmology have been proposed and studied intensively, in an effort to break the log-jam of the Standard Model. None of those hypotheses have succeeded to date. Of greater concern (...) is the increasing tendency by some practitioners in those fields to downplay the empirical principles of science. In response, this book is a restatement of those principles, covering numerous aspects of observation. A particular focus is on contextuality versus realism, the two fundamentally contrasting ideologies that underpin modern physics. (shrink)

I provide an account of precision testing in particle physics that makes a virtue of theory-ladenness in experiments. Combining recent work on the philosophy of experimentation with a broader view of the scientific process allows one to understand that the most precise and secure knowledge produced in a mature science cannot be achieved in a theory-independent fashion. I discuss precision tests of the muon’s magnetic moment and effective field theory as a means to repurpose precision tests for exploratory (...) purposes. (shrink)

A model for the quantum measurement of the electronic current in a Josephson junction is presented and analyzed. The model is similar to a Stern-Gerlach apparatus, relying on the deflection of a spin-polarized particle beam by the magnetic field created by the Josephson current. The aim is (1) to explore, with the help of a simple model, some general ideas about the nature of the information which can be obtained by measurements upon a quantum system and (...) (2) to find new approaches for obtaining information about the nature of the states of a macroscopic quantum system. In the case of sufficiently strong coupling between the system and the apparatus, we find that the model provides in principle a standard ideal measurement of the value of the instantaneous Josephson current. In the case of weak coupling, where the measurement is not ideal, we show that the scattering of neutrons from a junction can in principle be used to measure the average value of the Josephson current, thereby allowing an experimental distinction to be made between an eigenstate of relative phase and one of relative Cooper pair number. The possibility of the latter type of measurement suggests an experimental approach to answer a question of fundamental interest, namely whether two isolated superconductors (or superfluids) possess a definite relative phase or a definite relative number of superconducting (or super/lowing) particles. (shrink)

The paper discusses major implications of high energy physics for the scientific realism debate. The first part analyses the ways in which aspects of the empirically well-confirmed standard model of particle physics are relevant for a reassessment of entity realism, ontological realism and structural realism. The second part looks at the implications of more far-reaching concepts like string theory. While those theories have not found empirical confirmation, if they turned out viable, their implications for the (...) realism debate would be more substantial than those of the standard model. (shrink)

So far this has been a lonely and unrewarding quest. New experiments occasionally come along which point to a breakdown of the Standard Model, but up to now they have invariably been proved wrong by more careful analysis or subsequent experiments with better data. A case in point is the energetic jet data from the CDF experiment at FermiLab which suggested possible substructure of the quark. (See my AV column "Inside the Quark" in the September-1996 issue of Analog.) (...) The CDF group found an unexpected excess of "jets" (clumps of energetic particles moving in the same direction) with energies above 200 GeV in their data. They found that they could not explain this excess of high energy jets using the Standard Model, as interpreted by standard theoretical procedures, and they pointed out that the data might represent new physics, possibly an indication that the quark is a composite object made of even more fundamental particles. (shrink)

Conventional particle theories such as the Standard Model have a number of freely adjustable coupling constants and mass parameters, depending on the symmetry algebra of the local gauge group and the representations chosen for the spinor and scalar fields. There seems to be no physical principle to determine these parameters as long as they stay within certain domains dictated by the renormalization group. Here however, reasons are given to demand that, when gravity is coupled to the system, (...) local conformal invariance should be a spontaneously broken exact symmetry. The argument has to do with the requirement that black holes obey a complementarity principle relating ingoing observers to outside observers, or equivalently, initial states to final states. This condition fixes all parameters, including masses and the cosmological constant. We suspect that only examples can be found where these are all of order one in Planck units, but the values depend on the algebra chosen. This paper combines findings reported in two previous preprints (G. ’t Hooft in arXiv:1009.0669 [gr-qc], 2010; arXiv:1011.0061 [gr-qc], 2010) and puts these in a clearer perspective by shifting the emphasis towards the implications for particle models. (shrink)

In this paper I detail three major mathematical developments that led to the emergence of Yang–Mills theories as the foundation for the standard model of particle physics. In less than 10 years, work on renormalizability, the renormalization group, and lattice quantum field theory highlighted the utility of Yang–Mills type models of quantum field theory by connecting poorly understood candidate dynamical models to emerging experimental results. I use this historical case study to provide lessons for theory construction (...) in physics, and touch on issues related to renormalization group realism from a more historical perspective. In particular, I highlight the fact that much of the hard work in theory construction comes when trying to understand the consequences and representational capacities of a theoretical framework. (shrink)

This thesis is a work of experimental physics, a search for new physics with the ATLAS experiment. I post this thesis on the PhilArchive because it includes a pedagogical summary of quantum mechanics and the standard model of particle physics in the combination of chapters 1-2 and appendix A. This was my attempt at the end of my PhD of giving a bird's eye view of the standard model, with a thorough bibliography (...) of the publication trail that lead to its development. I find myself pointing to it at philosophy conferences. // -/- This thesis presents a review of work on the performance of the reconstruction and identification of hadronic tau decays and studies of events reconstructed with a ditau final state with the ATLAS detector at the Large Hadron Collider. The first cut-based tau identification used with ATLAS data and the first observations of W→τν and Z→ττ at ATLAS are described, as well as many of the issues concerning the calibration and systematic uncertainties of reconstructed taus. The first measurement of the Z→ττ cross section at ATLAS with 2010 dataset is reviewed. Last, results are presented from the first search for high-mass resonances decaying to ττ at ATLAS with the 2011 dataset. (shrink)

According to the Standard Model of particle physics, some gauge transformations are physical symmetries. That is, they are mathematical transformations that relate representatives of distinct physical states of affairs. This is at odds with the standard philosophical position according to which gauge transformations are an eliminable redundancy in a gauge theory's representational framework. In this paper I defend the Standard Model's treatment of gauge from an objection due to Richard Healey. If we follow (...) the Standard Model in taking some gauge transformations to be physical symmetries then we face the “strong CP problem”, but if we adopt the standard philosophical position on gauge then the strong CP problem dissolves. Healey offers this as a reason in favor of the standard philosophical view. However, as I argue here, following Healey's recommendation gives a theory that makes bad empirical predictions. (shrink)

The electron is considered as a massless point-particle which moves in a spacetime with (3+3) dimensions subjected to a field that attracts it towards the (3+1) standard spacetime. This field is assumed to be described by the radial time component of the e.m. 6-potential and to be due to the vacuum polarization arising when the charge of the electron is removed from the (3+1) spacetime. The pertinent Klein-Gordon equitation in 6 dimensions is solved and the right values for (...) the electron magnetic moment and spin are derived. The rest mass of the electron, as it appears in the standard (3+1) spacetime, is obtained as an integration constant from the motion in the two extra time dimensions. The very simple form assumed as a first approximation for the attractive potential does not give quantized rest masses. (shrink)

This paper analyses the practice of model-building “beyond the Standard Model” in contemporary high-energy physics and argues that its epistemic function can be grasped by regarding models as mediating between the phenomenology of the Standard Model and a number of “theoretical cores” of hybrid character, in which mathematical structures are combined with verbal narratives and analogies referring back to empirical results in other fields . Borrowing a metaphor from a physics research paper, (...) class='Hi'>model-building is likened to the search for a Rosetta stone, whose significance does not lie in its immediate content, but rather in the chance it offers to glimpse at and manipulate the components of hybrid theoretical constructs. I shall argue that the rise of hybrid theoretical constructs was prompted by the increasing use of nonrigorous mathematical heuristics in high-energy physics. Support for my theses will be offered in form of a historical–philosophical analysis of the emergence and development of the theoretical core centring on the notion that the Higgs boson is a composite particle. I will follow the heterogeneous elements which would eventually come to form this core from their individual emergence in the 1960s and 1970s, through their collective life as a theoretical core from 1979 until the present day. (shrink)

Supersymmetry (SUSY) has long been considered an exceptionally promising theory. A central role for the promise has been played by naturalness arguments. Yet, given the absence of experimental findings it is questionable whether the promise will ever be fulfilled. Here, I provide an analysis of the promises associated with SUSY, employing a concept of pursuitworthiness. A research program like SUSY is pursuitworthy if (1) it has the plausible potential to provide high epistemic gain and (2) that gain can be achieved (...) with manageable research efforts. Naturalness arguments have been employed to support both conditions (1) and (2). First, SUSY has been motivated by way of analogy: the proposed symmetry between fermions and bosons is supposed to 'protect' the small Higgs mass from large quantum corrections just as the electron mass is protected through the chiral symmetry. Thus, SUSY held the promise of solving a major problem of the Standard Model of particle physics. Second, naturalness arguments have been employed to indicate that such gain is achievable at relatively low cost: SUSY discoveries seemed to be well in reach of upcoming high-energy experiments. While the first part of the naturalness argument may have the right form to facilitate considerations of pursuitworthiness, the second part of the argument has been problematically overstated. (shrink)

In the paper we show that modern cosmology has a status of effective theory of the Universe similarly to the standard models in particle physics. We illustrate that the source of such a point of view is the fact that the complete theory of the Universe (TOE) should be complicated enough to derive observables. The role of epistemological emergence in the context of cosmological models (Cold Dark Matter vs. Lambda Cold Dark Matter) is also investigated. We demonstrate (...) that while the effective theories of the Universe are not conceptually simple and elegant, their strength lies in the predictive accuracy and data fitting required for the model testing. (shrink)

Many discussions in the metaphysics and philosophy of physics literature aim to use physics as a guide to elucidate what the world really, fundamentally is like. However, we don’t yet have a confirmed fundamental theory of physics—what’s the next best thing we can possibly say about the fundamental that is properly informed by our best theories of physics? This paper offers a starting point to address this question. It focuses on the literature on the ontology of (...) quantum mechanics, where the problem is especially salient: Many proposals aim at drawing the fundamental ontology of the world from quantum mechanics, even though they often focus on a non-fundamental theory such as nonrelativistic quantum particle mechanics. I argue that quantum mechanics can plausibly be informative about the fundamental if it is taken as a general framework theory, which covers a range of specific concrete theories, including nonrelativistic quantum particle mechanics, the Standard Model of particle physics, and string theory. I use Wavefunction Realism as an example to demonstrate what kind of ontological lessons about the world at the fundamental level the quantum framework may teach us. (shrink)

This article probes the question of what interpretations of quantum mechanics actually accomplish. In other domains, which are briefly considered, interpretations serve to make alien systematizations intelligible to us. This often involves clarifying the status of their implicit ontology. A survey of interpretations of non-relativistic quantum mechanics supports the evaluation that these interpretations make a contribution to philosophy, but not to physics. Interpretations of quantum field theory are polarized by the divergence between the Lagrangian field theory that led to (...) the Standard Model of Particle physics and the Algebraic quantum field theory, that discounts an ontology of particles. Ruetsche's interpretation, it is argued, offers a potential for loosening the sharp polarization that presently obtains. A brief evaluation focuses on the functional ontology of quantum field theory considered as an effective theory. (shrink)

Spacetime measurements and gravitational experiments are made by using objects, matter fields or particles and their mutual relationships. As a consequence, any operationally meaningful assertion about spacetime is in fact an assertion about the degrees of freedom of the matter (i.e. non gravitational) fields; those, say for definiteness, of the Standard Model of particle physics. As for any quantum theory, the dynamics of the matter fields can be described in terms of a unitary evolution of a (...) state vector in a Hilbert space. By writing the Hilbert space as a generic tensor product of “subsystems” we analyse the evolution of a state vector on an information theoretical basis and attempt to recover the usual spacetime relations from the information exchanges between these subsystems. We consider generic interacting second quantized models with a finite number of fermionic degrees of freedom and characterize on physical grounds the tensor product structure associated with the class of “localized systems” and therefore with “position”. We find that in the case of free theories no spacetime relation is operationally definable. On the contrary, by applying the same procedure to the simple interacting model of a one-dimensional Heisenberg spin chain we recover the tensor product structure usually associated with “position”. Finally, we discuss the possible role of gravity in this framework. (shrink)

The \CDM cosmological model is remarkable: with just six parameters it describes the evolution of the Universe from a very early time when all structures were quantum fluctuations on subatomic scales to the present, and it is consistent with a wealth of high-precision data, both laboratory measurements and astronomical observations. However, the foundation of \CDM involves physics beyond the standard model of particle physics: particle dark matter, dark energy and cosmic inflation. Until this (...) ‘new physics’ is clarified, \CDM is at best incomplete and at worst a phenomenological construct that accommodates the data. I discuss the path forward, which involves both discovery and disruption, some grand challenges and finally the limits of scientific cosmology. (shrink)

The Higgs mechanism is an essential but elusive component of the Standard Model of particle physics. Without it Yang‐Mills gauge theories would have been little more than a warm‐up exercise in the attempt to quantize gravity rather than serving as the basis for the Standard Model. This article focuses on two problems related to the Higgs mechanism clearly posed in Earman’s recent papers (Earman 2003, 2004a, 2004b): what is the gauge‐invariant content of the Higgs (...) mechanism, and what does it mean to break a local gauge symmetry? (shrink)

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 and beyond 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. (shrink)

This book offers fresh perspective on the role of phenomenology in the philosophy of physics which opens new avenues for discussion among physicists, "standard" philosophers of physics and philosophers with phenomenological leanings. Much has been written on the interrelations between philosophy and physics in the late 19th and early 20th century, and on the emergence of philosophy of science as an autonomous philosophical sub-discipline. This book is about the under-explored role of phenomenology in the development and (...) the philosophical interpretation of 20th century physics. Part 1 examines questions about the origins and value of phenomenological approaches to physics. Does the work of classical phenomenologists such as Husserl, Merleau-Ponty or Heidegger contain elements of systematic value to both the practice and our philosophical understanding of physics? How did classical phenomenology influence “standard” philosophy of science in the Anglo-American and other traditions? Part 2 probes questions on the role of phenomenology in the philosophies of physics and science: - Can phenomenology help to solve “Wigner’s puzzle”, the problem of the "unreasonable effectiveness" of mathematics in describing, explaining and predicting empirical phenomena? - Does phenomenology allow better understanding of the principle of gauge invariance at the core of the standard model of contemporary particle physics? - Does the phenomenological notion of “Lifeworld” stand in opposition to the “scientific metaphysics” movement, or is there potential for dialogue? Part 3 examines the measurement problem. Is the solution outlined by Fritz London and Edmond Bauer merely a re-statement of von Neumann’s view, or should it be regarded as a distinctively phenomenological take on the measurement problem? Is phenomenology a serious contender in continuing discussions of foundational questions of quantum mechanics? Can other interpretational frameworks such as quantum Bayesianism benefit from implementing phenomenological notions such as constitution or horizonal intentionality? (shrink)