Project acronym CGCglasmaQGP
Project The nonlinear high energy regime of Quantum Chromodynamics
Researcher (PI) Tuomas Veli Valtteri Lappi
Host Institution (HI) JYVASKYLAN YLIOPISTO
Country Finland
Call Details Consolidator Grant (CoG), PE2, ERC-2015-CoG
Summary "This proposal concentrates on Quantum Chromodynamics (QCD) in its least well understood "final frontier": the high energy limit. The aim is to treat the formation of quark gluon plasma in relativistic nuclear collisions together with other high energy processes in a consistent QCD framework. This project is topical now in order to fully understand the results from the maturing LHC heavy ion program. The high energy regime is characterized by a high density of gluons, whose nonlinear interactions are beyond the reach of simple perturbative calculations. High energy particles also propagate nearly on the light cone, unaccessible to Euclidean lattice calculations. The nonlinear interactions at high density lead to the phenomenon of gluon saturation. The emergence of the "saturation scale", a semihard typical transverse momentum, enables a weak coupling expansion around a nonperturbatively large color field. This project aims to make progress both in collider phenomenology and in more conceptual aspects of nonabelian gauge field dynamics at high energy density:
1. Significant advances towards higher order accuracy will be made in cross section calculations for processes where a dilute probe collides with the strong color field of a high energy nucleus.
2. The quantum fluctuations around the strong color fields in the initial stages of a relativistic heavy ion collision will be analyzed with a new numerical method based on an explicit linearization of the equations of motion, maintaining a well defined weak coupling limit.
3. Initial conditions for fluid dynamical descriptions of the quark gluon plasma phase in heavy ion collisions will be obtained from a constrained QCD calculation.
We propose to achieve these goals with modern analytical and numerical methods, on which the P.I. is a leading expert. This project would represent a leap in the field towards better quantitative first principles understanding of QCD in a new kinematical domain."
Summary
"This proposal concentrates on Quantum Chromodynamics (QCD) in its least well understood "final frontier": the high energy limit. The aim is to treat the formation of quark gluon plasma in relativistic nuclear collisions together with other high energy processes in a consistent QCD framework. This project is topical now in order to fully understand the results from the maturing LHC heavy ion program. The high energy regime is characterized by a high density of gluons, whose nonlinear interactions are beyond the reach of simple perturbative calculations. High energy particles also propagate nearly on the light cone, unaccessible to Euclidean lattice calculations. The nonlinear interactions at high density lead to the phenomenon of gluon saturation. The emergence of the "saturation scale", a semihard typical transverse momentum, enables a weak coupling expansion around a nonperturbatively large color field. This project aims to make progress both in collider phenomenology and in more conceptual aspects of nonabelian gauge field dynamics at high energy density:
1. Significant advances towards higher order accuracy will be made in cross section calculations for processes where a dilute probe collides with the strong color field of a high energy nucleus.
2. The quantum fluctuations around the strong color fields in the initial stages of a relativistic heavy ion collision will be analyzed with a new numerical method based on an explicit linearization of the equations of motion, maintaining a well defined weak coupling limit.
3. Initial conditions for fluid dynamical descriptions of the quark gluon plasma phase in heavy ion collisions will be obtained from a constrained QCD calculation.
We propose to achieve these goals with modern analytical and numerical methods, on which the P.I. is a leading expert. This project would represent a leap in the field towards better quantitative first principles understanding of QCD in a new kinematical domain."
Max ERC Funding
1 935 000 €
Duration
Start date: 2016-10-01, End date: 2021-09-30
Project acronym CODE
Project Condensation in designed systems
Researcher (PI) Paeivi Elina Toermae
Host Institution (HI) AALTO KORKEAKOULUSAATIO SR
Country Finland
Call Details Advanced Grant (AdG), PE2, ERC-2013-ADG
Summary "Quantum coherent phenomena, especially marcoscopic quantum coherence, are among the most striking predictions of quantum mechanics. They have lead to remarkable applications such as lasers and modern optical technologies, and in the future, breakthroughs such as quantum information processing are envisioned. Macroscopic quantum coherence is manifested in Bose-Einstein condensation (BEC), superfluidity, and superconductivity, which have been observed in a variety of systems and continue to be at the front line of scientific research. Here my objective is to extend the realm of Bose-Einstein condensation into new conceptual and practical directions. I focus on the role of a hybrid character of the object that condenses and on the role of non-equilibrium in the BEC phenomenon. The work is mostly theoretical but has also an experimental part. I study two new types of hybrids, fundamentally different from each other. First, I consider pairing and superfluidity in a mixed geometry. Experimental realization of mixed geometries is becoming feasible in ultracold gases. Second, I explore the possibility of finding novel hybrids of light and matter excitations that may display condensation. By combining insight from these two cases, my goal is to understand how the hybrid and non-equilibrium nature can be exploited to design desirable properties, such as high critical temperatures. In particular, in case of the new light-matter hybrids, the goal is to provide realistic scenarios for, and also experimentally demonstrate, a room temperature BEC."
Summary
"Quantum coherent phenomena, especially marcoscopic quantum coherence, are among the most striking predictions of quantum mechanics. They have lead to remarkable applications such as lasers and modern optical technologies, and in the future, breakthroughs such as quantum information processing are envisioned. Macroscopic quantum coherence is manifested in Bose-Einstein condensation (BEC), superfluidity, and superconductivity, which have been observed in a variety of systems and continue to be at the front line of scientific research. Here my objective is to extend the realm of Bose-Einstein condensation into new conceptual and practical directions. I focus on the role of a hybrid character of the object that condenses and on the role of non-equilibrium in the BEC phenomenon. The work is mostly theoretical but has also an experimental part. I study two new types of hybrids, fundamentally different from each other. First, I consider pairing and superfluidity in a mixed geometry. Experimental realization of mixed geometries is becoming feasible in ultracold gases. Second, I explore the possibility of finding novel hybrids of light and matter excitations that may display condensation. By combining insight from these two cases, my goal is to understand how the hybrid and non-equilibrium nature can be exploited to design desirable properties, such as high critical temperatures. In particular, in case of the new light-matter hybrids, the goal is to provide realistic scenarios for, and also experimentally demonstrate, a room temperature BEC."
Max ERC Funding
1 559 608 €
Duration
Start date: 2013-12-01, End date: 2018-11-30
Project acronym DenseMatter
Project High-density QCD matter from first principles
Researcher (PI) Aleksi VUORINEN
Host Institution (HI) HELSINGIN YLIOPISTO
Country Finland
Call Details Consolidator Grant (CoG), PE2, ERC-2016-COG
Summary Predicting the collective properties of strongly interacting matter at the highest densities reached within the present-day Universe is one of the most prominent challenges in modern nuclear theory. It is motivated by the desire to map out the complicated phase diagram of the theory, and perhaps even more importantly by the mystery surrounding the inner structure of neutron stars. The task is, however, severely complicated by the notorious Sign Problem of lattice QCD, due to which no nonperturbative first principles methods are available for tackling it.
The proposal at hand approaches the strong interaction challenge using a first principles toolbox containing most importantly the machinery of modern resummed perturbation theory and effective field theory. Our main technical goal is to determine three new orders in the weak coupling expansion of the Equation of State (EoS) of unpaired zero-temperature quark matter. Alongside this effort, we will investigate the derivation of a new type of effective description for cold and dense QCD, allowing us to include to the EoS contributions from quark pairing more accurately than what is possible at present.
The highlight result of our work will be the derivation of the most accurate neutron star matter EoS to date, which will be obtained by combining insights from our work with those originating from the Chiral Effective Theory of nuclear interactions. We anticipate being able to reduce the current uncertainty in the EoS by nearly a factor of two, which will convert into a precise prediction for the Mass-Radius relation of the stars. This will be a milestone result in nuclear astrophysics, and in combination with emerging observational data on stellar masses and radii will contribute to solving one of the most intriguing puzzles in the field – the nature of the most compact stars in the Universe.
Summary
Predicting the collective properties of strongly interacting matter at the highest densities reached within the present-day Universe is one of the most prominent challenges in modern nuclear theory. It is motivated by the desire to map out the complicated phase diagram of the theory, and perhaps even more importantly by the mystery surrounding the inner structure of neutron stars. The task is, however, severely complicated by the notorious Sign Problem of lattice QCD, due to which no nonperturbative first principles methods are available for tackling it.
The proposal at hand approaches the strong interaction challenge using a first principles toolbox containing most importantly the machinery of modern resummed perturbation theory and effective field theory. Our main technical goal is to determine three new orders in the weak coupling expansion of the Equation of State (EoS) of unpaired zero-temperature quark matter. Alongside this effort, we will investigate the derivation of a new type of effective description for cold and dense QCD, allowing us to include to the EoS contributions from quark pairing more accurately than what is possible at present.
The highlight result of our work will be the derivation of the most accurate neutron star matter EoS to date, which will be obtained by combining insights from our work with those originating from the Chiral Effective Theory of nuclear interactions. We anticipate being able to reduce the current uncertainty in the EoS by nearly a factor of two, which will convert into a precise prediction for the Mass-Radius relation of the stars. This will be a milestone result in nuclear astrophysics, and in combination with emerging observational data on stellar masses and radii will contribute to solving one of the most intriguing puzzles in the field – the nature of the most compact stars in the Universe.
Max ERC Funding
1 342 133 €
Duration
Start date: 2017-07-01, End date: 2022-06-30
Project acronym MAIDEN
Project Masses, isomers and decay studies for elemental nucleosynthesis
Researcher (PI) Anu KANKAINEN
Host Institution (HI) JYVASKYLAN YLIOPISTO
Country Finland
Call Details Consolidator Grant (CoG), PE2, ERC-2017-COG
Summary About half of the elements heavier than iron have been produced via the rapid neutron capture process, the r process. Its astrophysical site has been one of the biggest outstanding questions in physics. Neutrino-driven winds from proto-neutron stars created in core-collapse supernovae were long considered as the most favourable site for the r process. Recently, neutron-star mergers have become the most promising candidates, and new exciting observations from these compact objects, such as gravitational waves, are expected in the coming years. In order to constrain the astrophysical site for the r process, nuclear binding energies (i.e. masses) of exotic neutron-rich nuclei are needed because they determine the path for the process and therefore have a direct effect on the final isotopic abundances. In this project, high-precision mass measurements will be performed in three regions relevant for the r process, employing novel production and measurement techniques at the IGISOL facility in JYFL-ACCLAB. Long-living isomeric states, which also play a role in the r process, will be resolved from the ground states to obtain accurate mass values. Post-trap decay spectroscopy will be performed to confirm which state has been measured in order to avoid systematic uncertainties in the mass values. The new data will be compared with theoretical mass models and included in r-process calculations performed for various astrophysical sites. MAIDEN will advance our knowledge of nuclear structure far from stability and reduce nuclear data uncertainties in the r-process calculations, which can potentially constrain the astrophysical site for the r process and lead to a scientific breakthrough in our understanding of the origin of elements heavier than iron in the universe.
Summary
About half of the elements heavier than iron have been produced via the rapid neutron capture process, the r process. Its astrophysical site has been one of the biggest outstanding questions in physics. Neutrino-driven winds from proto-neutron stars created in core-collapse supernovae were long considered as the most favourable site for the r process. Recently, neutron-star mergers have become the most promising candidates, and new exciting observations from these compact objects, such as gravitational waves, are expected in the coming years. In order to constrain the astrophysical site for the r process, nuclear binding energies (i.e. masses) of exotic neutron-rich nuclei are needed because they determine the path for the process and therefore have a direct effect on the final isotopic abundances. In this project, high-precision mass measurements will be performed in three regions relevant for the r process, employing novel production and measurement techniques at the IGISOL facility in JYFL-ACCLAB. Long-living isomeric states, which also play a role in the r process, will be resolved from the ground states to obtain accurate mass values. Post-trap decay spectroscopy will be performed to confirm which state has been measured in order to avoid systematic uncertainties in the mass values. The new data will be compared with theoretical mass models and included in r-process calculations performed for various astrophysical sites. MAIDEN will advance our knowledge of nuclear structure far from stability and reduce nuclear data uncertainties in the r-process calculations, which can potentially constrain the astrophysical site for the r process and lead to a scientific breakthrough in our understanding of the origin of elements heavier than iron in the universe.
Max ERC Funding
1 999 575 €
Duration
Start date: 2018-06-01, End date: 2023-05-31
Project acronym SHESTRUCT
Project Understanding the structure and stability of heavy and superheavy elements
Researcher (PI) Paul Thomas Greenlees
Host Institution (HI) JYVASKYLAN YLIOPISTO
Country Finland
Call Details Starting Grant (StG), PE2, ERC-2007-StG
Summary "The aim of the project is to further our understanding of the structure and stability of atomic nuclei at the extreme upper end of the chart of the nuclides. One of the major goals of contemporary Nuclear Physics experiments is to locate and chart the fabled superheavy element ""Island of Stability"". Experiments which aim to directly produce the heaviest elements may provide only a limited number of observables, such as decay modes or half-lives. Detailed Nuclear Structure investigations provide extensive data which can be used as a stringent test of modern self-consistent theories. Such theories require input from the study of nuclei with extreme proton-to-neutron ratios. The upper part of the chart of the nuclides is one region in which this data is much sought after. The project will employ state-of-the-art spectrometers at the Accelerator Laboratory of the University of Jyväskylä, Finland (JYFL) to acquire such data. The spectrometers are part of a multi-national collaboration of European institutes. Results obtained in the course of the project will have a direct impact on current nuclear structure theories. The unique nature of the facilities at JYFL means that it will be impossible to obtain data of comparable quality elsewhere in the world. The project should yield a large number of publications and result in the training of several Ph.D students. The students will benefit from the fact that the Accelerator Laboratory is part of a large and well-respected University."
Summary
"The aim of the project is to further our understanding of the structure and stability of atomic nuclei at the extreme upper end of the chart of the nuclides. One of the major goals of contemporary Nuclear Physics experiments is to locate and chart the fabled superheavy element ""Island of Stability"". Experiments which aim to directly produce the heaviest elements may provide only a limited number of observables, such as decay modes or half-lives. Detailed Nuclear Structure investigations provide extensive data which can be used as a stringent test of modern self-consistent theories. Such theories require input from the study of nuclei with extreme proton-to-neutron ratios. The upper part of the chart of the nuclides is one region in which this data is much sought after. The project will employ state-of-the-art spectrometers at the Accelerator Laboratory of the University of Jyväskylä, Finland (JYFL) to acquire such data. The spectrometers are part of a multi-national collaboration of European institutes. Results obtained in the course of the project will have a direct impact on current nuclear structure theories. The unique nature of the facilities at JYFL means that it will be impossible to obtain data of comparable quality elsewhere in the world. The project should yield a large number of publications and result in the training of several Ph.D students. The students will benefit from the fact that the Accelerator Laboratory is part of a large and well-respected University."
Max ERC Funding
1 249 608 €
Duration
Start date: 2008-09-01, End date: 2014-02-28
