Project acronym ALMA
Project Attosecond Control of Light and Matter
Researcher (PI) Anne L'huillier
Host Institution (HI) MAX IV Laboratory, Lund University
Country Sweden
Call Details Advanced Grant (AdG), PE2, ERC-2008-AdG
Summary Attosecond light pulses are generated when an intense laser interacts with a gas target. These pulses are not only short, enabling the study of electronic processes at their natural time scale, but also coherent. The vision of this proposal is to extend temporal coherent control concepts to a completely new regime of time and energy, combining (i) ultrashort pulses (ii) broadband excitation (iii) high photon energy, allowing scientists to reach not only valence but also inner shells in atoms and molecules, and, when needed, (iv) high spatial resolution. We want to explore how elementary electronic processes in atoms, molecules and more complex systems can be controlled by using well designed sequences of attosecond pulses. The research project proposed is organized into four parts: 1. Attosecond control of light leading to controlled sequences of attosecond pulses We will develop techniques to generate sequences of attosecond pulses with a variable number of pulses and controlled carrier-envelope-phase variation between consecutive pulses. 2. Attosecond control of electronic processes in atoms and molecules We will investigate the dynamics and coherence of phenomena induced by attosecond excitation of electron wave packets in various systems and we will explore how they can be controlled by a controlled sequence of ultrashort pulses. 3. Intense attosecond sources to reach the nonlinear regime We will optimize attosecond light sources in a systematic way, including amplification of the radiation by injecting a free electron laser. This will open up the possibility to develop nonlinear measurement and control schemes. 4. Attosecond control in more complex systems, including high spatial resolution We will develop ultrafast microscopy techniques, in order to obtain meaningful temporal information in surface and solid state physics. Two directions will be explored, digital in line microscopic holography and photoemission electron microscopy.
Summary
Attosecond light pulses are generated when an intense laser interacts with a gas target. These pulses are not only short, enabling the study of electronic processes at their natural time scale, but also coherent. The vision of this proposal is to extend temporal coherent control concepts to a completely new regime of time and energy, combining (i) ultrashort pulses (ii) broadband excitation (iii) high photon energy, allowing scientists to reach not only valence but also inner shells in atoms and molecules, and, when needed, (iv) high spatial resolution. We want to explore how elementary electronic processes in atoms, molecules and more complex systems can be controlled by using well designed sequences of attosecond pulses. The research project proposed is organized into four parts: 1. Attosecond control of light leading to controlled sequences of attosecond pulses We will develop techniques to generate sequences of attosecond pulses with a variable number of pulses and controlled carrier-envelope-phase variation between consecutive pulses. 2. Attosecond control of electronic processes in atoms and molecules We will investigate the dynamics and coherence of phenomena induced by attosecond excitation of electron wave packets in various systems and we will explore how they can be controlled by a controlled sequence of ultrashort pulses. 3. Intense attosecond sources to reach the nonlinear regime We will optimize attosecond light sources in a systematic way, including amplification of the radiation by injecting a free electron laser. This will open up the possibility to develop nonlinear measurement and control schemes. 4. Attosecond control in more complex systems, including high spatial resolution We will develop ultrafast microscopy techniques, in order to obtain meaningful temporal information in surface and solid state physics. Two directions will be explored, digital in line microscopic holography and photoemission electron microscopy.
Max ERC Funding
2 250 000 €
Duration
Start date: 2008-12-01, End date: 2013-11-30
Project acronym ANSR
Project Ab initio approach to nuclear structure and reactions (++)
Researcher (PI) Christian Erik Forssen
Host Institution (HI) CHALMERS TEKNISKA HOEGSKOLA AB
Country Sweden
Call Details Starting Grant (StG), PE2, ERC-2009-StG
Summary Today, much interest in several fields of physics is devoted to the study of small, open quantum systems, whose properties are profoundly affected by the environment; i.e., the continuum of decay channels. In nuclear physics, these problems were originally studied in the context of nuclear reactions but their importance has been reestablished with the advent of radioactive-beam physics and the resulting interest in exotic nuclei. In particular, strong theory initiatives in this area of research will be instrumental for the success of the experimental program at the Facility for Antiproton and Ion Research (FAIR) in Germany. In addition, many of the aspects of open quantum systems are also being explored in the rapidly evolving research on ultracold atomic gases, quantum dots, and other nanodevices. A first-principles description of open quantum systems presents a substantial theoretical and computational challenge. However, the current availability of enormous computing power has allowed theorists to make spectacular progress on problems that were previously thought intractable. The importance of computational methods to study quantum many-body systems is stressed in this proposal. Our approach is based on the ab initio no-core shell model (NCSM), which is a well-established theoretical framework aimed originally at an exact description of nuclear structure starting from realistic inter-nucleon forces. A successful completion of this project requires extensions of the NCSM mathematical framework and the development of highly advanced computer codes. The '++' in the project title indicates the interdisciplinary aspects of the present research proposal and the ambition to make a significant impact on connected fields of many-body physics.
Summary
Today, much interest in several fields of physics is devoted to the study of small, open quantum systems, whose properties are profoundly affected by the environment; i.e., the continuum of decay channels. In nuclear physics, these problems were originally studied in the context of nuclear reactions but their importance has been reestablished with the advent of radioactive-beam physics and the resulting interest in exotic nuclei. In particular, strong theory initiatives in this area of research will be instrumental for the success of the experimental program at the Facility for Antiproton and Ion Research (FAIR) in Germany. In addition, many of the aspects of open quantum systems are also being explored in the rapidly evolving research on ultracold atomic gases, quantum dots, and other nanodevices. A first-principles description of open quantum systems presents a substantial theoretical and computational challenge. However, the current availability of enormous computing power has allowed theorists to make spectacular progress on problems that were previously thought intractable. The importance of computational methods to study quantum many-body systems is stressed in this proposal. Our approach is based on the ab initio no-core shell model (NCSM), which is a well-established theoretical framework aimed originally at an exact description of nuclear structure starting from realistic inter-nucleon forces. A successful completion of this project requires extensions of the NCSM mathematical framework and the development of highly advanced computer codes. The '++' in the project title indicates the interdisciplinary aspects of the present research proposal and the ambition to make a significant impact on connected fields of many-body physics.
Max ERC Funding
1 304 800 €
Duration
Start date: 2009-12-01, End date: 2014-11-30
Project acronym AXION
Project Axions: From Heaven to Earth
Researcher (PI) Frank Wilczek
Host Institution (HI) STOCKHOLMS UNIVERSITET
Country Sweden
Call Details Advanced Grant (AdG), PE2, ERC-2016-ADG
Summary Axions are hypothetical particles whose existence would solve two major problems: the strong P, T problem (a major blemish on the standard model); and the dark matter problem. It is a most important goal to either observe or rule out the existence of a cosmic axion background. It appears that decisive observations may be possible, but only after orchestrating insight from specialities ranging from quantum field theory and astrophysical modeling to ultra-low noise quantum measurement theory. Detailed predictions for the magnitude and structure of the cosmic axion background depend on cosmological and astrophysical modeling, which can be constrained by theoretical insight and numerical simulation. In parallel, we must optimize strategies for extracting accessible signals from that very weakly interacting source.
While the existence of axions as fundamental particles remains hypothetical, the equations governing how axions interact with electromagnetic fields also govern (with different parameters) how certain materials interact with electromagnetic fields. Thus those materials embody “emergent” axions. The equations have remarkable properties, which one can test in these materials, and possibly put to practical use.
Closely related to axions, mathematically, are anyons. Anyons are particle-like excitations that elude the familiar classification into bosons and fermions. Theoretical and numerical studies indicate that they are common emergent features of highly entangled states of matter in two dimensions. Recent work suggests the existence of states of matter, both natural and engineered, in which anyon dynamics is both important and experimentally accessible. Since the equations for anyons and axions are remarkably similar, and both have common, deep roots in symmetry and topology, it will be fruitful to consider them together.
Summary
Axions are hypothetical particles whose existence would solve two major problems: the strong P, T problem (a major blemish on the standard model); and the dark matter problem. It is a most important goal to either observe or rule out the existence of a cosmic axion background. It appears that decisive observations may be possible, but only after orchestrating insight from specialities ranging from quantum field theory and astrophysical modeling to ultra-low noise quantum measurement theory. Detailed predictions for the magnitude and structure of the cosmic axion background depend on cosmological and astrophysical modeling, which can be constrained by theoretical insight and numerical simulation. In parallel, we must optimize strategies for extracting accessible signals from that very weakly interacting source.
While the existence of axions as fundamental particles remains hypothetical, the equations governing how axions interact with electromagnetic fields also govern (with different parameters) how certain materials interact with electromagnetic fields. Thus those materials embody “emergent” axions. The equations have remarkable properties, which one can test in these materials, and possibly put to practical use.
Closely related to axions, mathematically, are anyons. Anyons are particle-like excitations that elude the familiar classification into bosons and fermions. Theoretical and numerical studies indicate that they are common emergent features of highly entangled states of matter in two dimensions. Recent work suggests the existence of states of matter, both natural and engineered, in which anyon dynamics is both important and experimentally accessible. Since the equations for anyons and axions are remarkably similar, and both have common, deep roots in symmetry and topology, it will be fruitful to consider them together.
Max ERC Funding
2 324 391 €
Duration
Start date: 2017-09-01, End date: 2022-08-31
Project acronym Bug-Flash
Project Coherent Back-Lasing from Atmospheric Insects
Researcher (PI) Mikkel Brydegaard Soerensen
Host Institution (HI) LUNDS UNIVERSITET
Country Sweden
Call Details Starting Grant (StG), PE2, ERC-2019-STG
Summary I received I received the prestigious Inaba award by the lidar community for advancing lidar entomology. Our Scheimpflug lidar can be implemented at 1% of the conventional cost and weight. It allows atmospheric observation with unpreceded sensitivity and spatiotemporal resolution. The kHz sampling rates can exceed the round-trip time of the light and reveal the modulation spectra for classifying free flying insect species over ground. The method has infinite focal depth and efficiently profiles sparse organisms in the airspace with 100000 observations per day. This tool is of key importance for tackling challenges related to pollinator diversity, agricultural pests and pesticides and malaria disease vectors. As in radar entomology, in situ lidar monitoring apparently has inevitable limitations: 1) Detection limit deteriorate with range, and far observations are biased towards larger organisms, 2) It takes several wing-beats, and therefore time, beam-width and energy to retrieve a modulation spectrum for classifying species. I propose to remove range biasing and classify insects by a microsecond flash of light. Back-lasing in air has been a dream of physicists for half a century. I now intend to capture specular reflexes from flat wing membranes. When the surface normal coincides with the lidar transect, collimated back-propagating laser light is accomplished. This flash of light is spectrally fringed and can report on the membrane thickness for target classification purpose. This project has three ambitious milestones of increasing challenge with in situ campaigns:
A) Polarimetric kHz lidar: Verification of specular flashes, investigation of range dependence, properties and likelihood.
B) Remote nanoscopy: Spectral analysis of remotely retrieved flashes for membrane thickness assessment and optimization of back-scatter resonance.
C) Farfetched flatness: I will enhance apparent surface roughness and collimated back-scatter from diffuse specimen by infrared methods
Summary
I received I received the prestigious Inaba award by the lidar community for advancing lidar entomology. Our Scheimpflug lidar can be implemented at 1% of the conventional cost and weight. It allows atmospheric observation with unpreceded sensitivity and spatiotemporal resolution. The kHz sampling rates can exceed the round-trip time of the light and reveal the modulation spectra for classifying free flying insect species over ground. The method has infinite focal depth and efficiently profiles sparse organisms in the airspace with 100000 observations per day. This tool is of key importance for tackling challenges related to pollinator diversity, agricultural pests and pesticides and malaria disease vectors. As in radar entomology, in situ lidar monitoring apparently has inevitable limitations: 1) Detection limit deteriorate with range, and far observations are biased towards larger organisms, 2) It takes several wing-beats, and therefore time, beam-width and energy to retrieve a modulation spectrum for classifying species. I propose to remove range biasing and classify insects by a microsecond flash of light. Back-lasing in air has been a dream of physicists for half a century. I now intend to capture specular reflexes from flat wing membranes. When the surface normal coincides with the lidar transect, collimated back-propagating laser light is accomplished. This flash of light is spectrally fringed and can report on the membrane thickness for target classification purpose. This project has three ambitious milestones of increasing challenge with in situ campaigns:
A) Polarimetric kHz lidar: Verification of specular flashes, investigation of range dependence, properties and likelihood.
B) Remote nanoscopy: Spectral analysis of remotely retrieved flashes for membrane thickness assessment and optimization of back-scatter resonance.
C) Farfetched flatness: I will enhance apparent surface roughness and collimated back-scatter from diffuse specimen by infrared methods
Max ERC Funding
1 499 487 €
Duration
Start date: 2020-02-01, End date: 2025-01-31
Project acronym collectiveQCD
Project Collectivity in small, srongly interacting systems
Researcher (PI) Korinna ZAPP
Host Institution (HI) LUNDS UNIVERSITET
Country Sweden
Call Details Starting Grant (StG), PE2, ERC-2018-STG
Summary In collisions of heavy nuclei at collider energies, for instance at the Large Hadron Collider (LHC) at CERN, the energy density is so high that an equilibrated Quark-Gluon Plasma (QGP), an exotic state of matter consisting of deconfined quarks and gluons, is formed. In proton-proton (p+p) collisions, on the other hand, the density of produced particles is low. The traditional view on such reactions is that final state particles are free and do not rescatter. This picture is challenged by recent LHC data, which found features in p+p collisions that are indicative of collective behaviour and/or the formation of a hot and dense system. These findings have been taken as signs of QGP formation in p+p reactions. Such an interpretation is complicated by the fact that jets, which are the manifestation of very energetic quarks and gluons, are quenched in heavy ion collisions, but appear to be unmodified in p+p reactions. This is puzzling because collectivity and jet quenching are caused by the same processes. So far there is no consensus about the interpretation of these results, which is also due to a lack of suitable tools.
It is the objective of this proposal to address the question whether there are collective effects in p+p collisions. To this end two models capable of describing all relevant aspects of p+p and heavy ion collisions will be developed. They will be obtained by extending a successful description of p+p to heavy ion reactions and vice versa.
The answer to these questions will either clarify the long-standing problem how collectivity emerges from fundamental interactions, or it will necessitate qualitative changes to our interpretation of collective phenomena in p+p and/or heavy ion collisions.
The PI is in a unique position to accomplish this goal, as she has spent her entire career working on different aspects of p+p and heavy ion collisions. The group in Lund is the ideal host, as it is very active in developing alternative interpretations of the data.
Summary
In collisions of heavy nuclei at collider energies, for instance at the Large Hadron Collider (LHC) at CERN, the energy density is so high that an equilibrated Quark-Gluon Plasma (QGP), an exotic state of matter consisting of deconfined quarks and gluons, is formed. In proton-proton (p+p) collisions, on the other hand, the density of produced particles is low. The traditional view on such reactions is that final state particles are free and do not rescatter. This picture is challenged by recent LHC data, which found features in p+p collisions that are indicative of collective behaviour and/or the formation of a hot and dense system. These findings have been taken as signs of QGP formation in p+p reactions. Such an interpretation is complicated by the fact that jets, which are the manifestation of very energetic quarks and gluons, are quenched in heavy ion collisions, but appear to be unmodified in p+p reactions. This is puzzling because collectivity and jet quenching are caused by the same processes. So far there is no consensus about the interpretation of these results, which is also due to a lack of suitable tools.
It is the objective of this proposal to address the question whether there are collective effects in p+p collisions. To this end two models capable of describing all relevant aspects of p+p and heavy ion collisions will be developed. They will be obtained by extending a successful description of p+p to heavy ion reactions and vice versa.
The answer to these questions will either clarify the long-standing problem how collectivity emerges from fundamental interactions, or it will necessitate qualitative changes to our interpretation of collective phenomena in p+p and/or heavy ion collisions.
The PI is in a unique position to accomplish this goal, as she has spent her entire career working on different aspects of p+p and heavy ion collisions. The group in Lund is the ideal host, as it is very active in developing alternative interpretations of the data.
Max ERC Funding
1 500 000 €
Duration
Start date: 2019-02-01, End date: 2024-01-31
Project acronym CurvedSusy
Project Dynamics of Supersymmetry in Curved Space
Researcher (PI) Guido Festuccia
Host Institution (HI) UPPSALA UNIVERSITET
Country Sweden
Call Details Starting Grant (StG), PE2, ERC-2014-STG
Summary Quantum field theory provides a theoretical framework to explain quantitatively natural phenomena as diverse as the fluctuations in the cosmic microwave background, superconductivity, and elementary particle interactions in colliders. Even if we use quantum field theories in different settings, their structure and dynamics are still largely mysterious. Weakly coupled systems can be studied perturbatively, however many natural phenomena are characterized by strong self-interactions (e.g. high T superconductors, nuclear forces) and their analysis requires going beyond perturbation theory. Supersymmetric field theories are very interesting in this respect because they can be studied exactly even at strong coupling and their dynamics displays phenomena like confinement or the breaking of chiral symmetries that occur in nature and are very difficult to study analytically.
Recently it was realized that many interesting insights on the dynamics of supersymmetric field theories can be obtained by placing these theories in curved space preserving supersymmetry. These advances have opened new research avenues but also left many important questions unanswered. The aim of our research programme will be to clarify the dynamics of supersymmetric field theories in curved space and use this knowledge to establish new exact results for strongly coupled supersymmetric gauge theories. The novelty of our approach resides in the systematic use of the interplay between the physical properties of a supersymmetric theory and the geometrical properties of the space-time it lives in. The analytical results we will obtain, while derived for very symmetric theories, can be used as a guide in understanding the dynamics of many physical systems. Besides providing new tools to address the dynamics of quantum field theory at strong coupling this line of investigation could lead to new connections between Physics and Mathematics.
Summary
Quantum field theory provides a theoretical framework to explain quantitatively natural phenomena as diverse as the fluctuations in the cosmic microwave background, superconductivity, and elementary particle interactions in colliders. Even if we use quantum field theories in different settings, their structure and dynamics are still largely mysterious. Weakly coupled systems can be studied perturbatively, however many natural phenomena are characterized by strong self-interactions (e.g. high T superconductors, nuclear forces) and their analysis requires going beyond perturbation theory. Supersymmetric field theories are very interesting in this respect because they can be studied exactly even at strong coupling and their dynamics displays phenomena like confinement or the breaking of chiral symmetries that occur in nature and are very difficult to study analytically.
Recently it was realized that many interesting insights on the dynamics of supersymmetric field theories can be obtained by placing these theories in curved space preserving supersymmetry. These advances have opened new research avenues but also left many important questions unanswered. The aim of our research programme will be to clarify the dynamics of supersymmetric field theories in curved space and use this knowledge to establish new exact results for strongly coupled supersymmetric gauge theories. The novelty of our approach resides in the systematic use of the interplay between the physical properties of a supersymmetric theory and the geometrical properties of the space-time it lives in. The analytical results we will obtain, while derived for very symmetric theories, can be used as a guide in understanding the dynamics of many physical systems. Besides providing new tools to address the dynamics of quantum field theory at strong coupling this line of investigation could lead to new connections between Physics and Mathematics.
Max ERC Funding
1 145 879 €
Duration
Start date: 2015-09-01, End date: 2020-08-31
Project acronym DARKJETS
Project Discovery strategies for Dark Matter and new phenomena in hadronic signatures with the ATLAS detector at the Large Hadron Collider
Researcher (PI) Caterina Doglioni
Host Institution (HI) LUNDS UNIVERSITET
Country Sweden
Call Details Starting Grant (StG), PE2, ERC-2015-STG
Summary The Standard Model of Particle Physics describes the fundamental components of ordinary matter and their interactions. Despite its success in predicting many experimental results, the Standard Model fails to account for a number of interesting phenomena. One phenomenon of particular interest is the large excess of unobservable (Dark) matter in the Universe. This excess cannot be explained by Standard Model particles. A compelling hypothesis is that Dark Matter is comprised of particles that can be produced in the proton-proton collisions from the Large Hadron Collider (LHC) at CERN.
Within this project, I will build a team of researchers at Lund University dedicated to searches for signals of the presence of Dark Matter particles. The discovery strategies employed seek the decays of particles that either mediate the interactions between Dark and Standard Model particles or are produced in association with Dark Matter. These new particles manifest in detectors as two, three, or four collimated jets of particles (hadronic jets).
The LHC will resume delivery of proton-proton collisions to the ATLAS detector in 2015. Searches for new, rare, low mass particles such as Dark Matter mediators have so far been hindered by constraints on the rates of data that can be stored. These constraints will be overcome through the implementation of a novel real-time data analysis technique and a new search signature, both introduced to ATLAS by this project. The coincidence of this project with the upcoming LHC runs and the software and hardware improvements within the ATLAS detector is a unique opportunity to increase the sensitivity to hadronically decaying new particles by a large margin with respect to any previous searches. The results of these searches will be interpreted within a comprehensive and coherent set of theoretical benchmarks, highlighting the strengths of collider experiments in the global quest for Dark Matter.
Summary
The Standard Model of Particle Physics describes the fundamental components of ordinary matter and their interactions. Despite its success in predicting many experimental results, the Standard Model fails to account for a number of interesting phenomena. One phenomenon of particular interest is the large excess of unobservable (Dark) matter in the Universe. This excess cannot be explained by Standard Model particles. A compelling hypothesis is that Dark Matter is comprised of particles that can be produced in the proton-proton collisions from the Large Hadron Collider (LHC) at CERN.
Within this project, I will build a team of researchers at Lund University dedicated to searches for signals of the presence of Dark Matter particles. The discovery strategies employed seek the decays of particles that either mediate the interactions between Dark and Standard Model particles or are produced in association with Dark Matter. These new particles manifest in detectors as two, three, or four collimated jets of particles (hadronic jets).
The LHC will resume delivery of proton-proton collisions to the ATLAS detector in 2015. Searches for new, rare, low mass particles such as Dark Matter mediators have so far been hindered by constraints on the rates of data that can be stored. These constraints will be overcome through the implementation of a novel real-time data analysis technique and a new search signature, both introduced to ATLAS by this project. The coincidence of this project with the upcoming LHC runs and the software and hardware improvements within the ATLAS detector is a unique opportunity to increase the sensitivity to hadronically decaying new particles by a large margin with respect to any previous searches. The results of these searches will be interpreted within a comprehensive and coherent set of theoretical benchmarks, highlighting the strengths of collider experiments in the global quest for Dark Matter.
Max ERC Funding
1 268 076 €
Duration
Start date: 2016-02-01, End date: 2021-07-31
Project acronym INTEGRAL
Project Integrable Systems in Gauge and String Theory
Researcher (PI) Konstantin Zarembo
Host Institution (HI) STOCKHOLMS UNIVERSITET
Country Sweden
Call Details Advanced Grant (AdG), PE2, ERC-2013-ADG
Summary The project is aimed at uncovering new links between integrable systems, string theory and quantum field theory. The goal is to study non-perturbative phenomena in strongly-coupled field theories, and to understand relationship between gauge fields and strings at a deeper level.
Summary
The project is aimed at uncovering new links between integrable systems, string theory and quantum field theory. The goal is to study non-perturbative phenomena in strongly-coupled field theories, and to understand relationship between gauge fields and strings at a deeper level.
Max ERC Funding
1 693 692 €
Duration
Start date: 2014-03-01, End date: 2019-02-28
Project acronym MEMO
Project The Memory of Solitons
Researcher (PI) MICHELE DEL ZOTTO
Host Institution (HI) UPPSALA UNIVERSITET
Country Sweden
Call Details Starting Grant (StG), PE2, ERC-2019-STG
Summary Quantum field theory (QFT) is undoubtedly one of the most important achievements of modern theoretical physics, with broad applications ranging from condensed matter systems to elementary particle physics. Despite its successes, the current formulation of QFT is incomplete and we lack tools to address from first principles a wide variety of interesting physical systems, including the dynamics of quarks within protons, phase transitions, and high temperature superconductors. The present project aims at addressing this issue by establishing a novel, powerful and unconventional paradigm for QFT without relying upon the existence of a perturbative expansion. The cornerstone for such a paradigm is the following remark: in a wide variety of simple examples it is possible to compute exactly the values of several observables relying solely upon the knowledge of the spectrum of solitons of the given QFT. I call this effect the memory of solitons. My goal is to establish a research group that will develop and exploit the memory of solitons to study non-perturbative aspects of QFTs. The proposed strategy to approach this problem is twofold. On the one hand I focus on the simplest QFTs to develop my intuition on concrete and explicit examples: my laboratory consists of theories having supersymmetry and/or conformal symmetry where a plethora of exact results are available in the literature. On the other I exploit geometric engineering techniques in string theory, which gives access to the non-perturbative spectrum of QFTs from a completely different angle that allows exact computations to be performed, providing new insights into the mathematical structure of the theories involved. The combination of these techniques is so powerful that I have already obtained a wide variety of results that could not be derived by any other known method.
Summary
Quantum field theory (QFT) is undoubtedly one of the most important achievements of modern theoretical physics, with broad applications ranging from condensed matter systems to elementary particle physics. Despite its successes, the current formulation of QFT is incomplete and we lack tools to address from first principles a wide variety of interesting physical systems, including the dynamics of quarks within protons, phase transitions, and high temperature superconductors. The present project aims at addressing this issue by establishing a novel, powerful and unconventional paradigm for QFT without relying upon the existence of a perturbative expansion. The cornerstone for such a paradigm is the following remark: in a wide variety of simple examples it is possible to compute exactly the values of several observables relying solely upon the knowledge of the spectrum of solitons of the given QFT. I call this effect the memory of solitons. My goal is to establish a research group that will develop and exploit the memory of solitons to study non-perturbative aspects of QFTs. The proposed strategy to approach this problem is twofold. On the one hand I focus on the simplest QFTs to develop my intuition on concrete and explicit examples: my laboratory consists of theories having supersymmetry and/or conformal symmetry where a plethora of exact results are available in the literature. On the other I exploit geometric engineering techniques in string theory, which gives access to the non-perturbative spectrum of QFTs from a completely different angle that allows exact computations to be performed, providing new insights into the mathematical structure of the theories involved. The combination of these techniques is so powerful that I have already obtained a wide variety of results that could not be derived by any other known method.
Max ERC Funding
1 491 275 €
Duration
Start date: 2020-02-01, End date: 2025-01-31
Project acronym MorePheno
Project Collider Phenomenology and Event Generators
Researcher (PI) Haakan Torbjoern Sjoestrand
Host Institution (HI) LUNDS UNIVERSITET
Country Sweden
Call Details Advanced Grant (AdG), PE2, ERC-2014-ADG
Summary Collider physics is about exploring the smallest constituents of matter, and unravelling the basic laws of the Universe. Unfortunately there can be a huge gap between a one-line formula of a fundamental theory and the experimental reality it implies. Phenomenology is intended to fill that gap, e.g. to explore the consequences of a theory such that it can be directly compared with data.
Nowhere is the gap more striking than for QCD, the theory of strong interactions, which dominates in most high-energy collisions, like at the LHC (Large Hadron Collider) at CERN. And yet, when such collisions produce hundreds of outgoing particles, calculational complexity is insurmountable. Instead ingenious but approximate QCD-inspired models have to be invented.
Such models are especially powerful if they can be cast in the form of computer code, and combined to provide a complete description of the collision process. An event generator is such a code, where random numbers are used to emulate the quantum mechanical uncertainty that leads to no two collision events being quite identical.
The Principal Investigator is the main author of PYTHIA, the most widely used event generator of the last 30 years and vital for physics studies at the LHC. It is in a state of continuous extension: new concepts are invented, new models developed, new code written, to provide an increasingly accurate understanding of collider physics. But precise LHC data has put a demand on far more precise descriptions, and have also shown that some models need to be rethought from the ground up.
This project, at its core, is about conducting more frontline research with direct implications for event generators, embedded in a broader phenomenology context. In addition to the PI, the members of the theoretical high energy physics group in Lund and of the PYTHIA collaboration will participate in this project, as well as graduate students and postdocs.
Summary
Collider physics is about exploring the smallest constituents of matter, and unravelling the basic laws of the Universe. Unfortunately there can be a huge gap between a one-line formula of a fundamental theory and the experimental reality it implies. Phenomenology is intended to fill that gap, e.g. to explore the consequences of a theory such that it can be directly compared with data.
Nowhere is the gap more striking than for QCD, the theory of strong interactions, which dominates in most high-energy collisions, like at the LHC (Large Hadron Collider) at CERN. And yet, when such collisions produce hundreds of outgoing particles, calculational complexity is insurmountable. Instead ingenious but approximate QCD-inspired models have to be invented.
Such models are especially powerful if they can be cast in the form of computer code, and combined to provide a complete description of the collision process. An event generator is such a code, where random numbers are used to emulate the quantum mechanical uncertainty that leads to no two collision events being quite identical.
The Principal Investigator is the main author of PYTHIA, the most widely used event generator of the last 30 years and vital for physics studies at the LHC. It is in a state of continuous extension: new concepts are invented, new models developed, new code written, to provide an increasingly accurate understanding of collider physics. But precise LHC data has put a demand on far more precise descriptions, and have also shown that some models need to be rethought from the ground up.
This project, at its core, is about conducting more frontline research with direct implications for event generators, embedded in a broader phenomenology context. In addition to the PI, the members of the theoretical high energy physics group in Lund and of the PYTHIA collaboration will participate in this project, as well as graduate students and postdocs.
Max ERC Funding
1 990 895 €
Duration
Start date: 2015-11-01, End date: 2020-10-31
