Nuclear Physics Consolidated Grant 2020
Lead Research Organisation:
University of Liverpool
Department Name: Physics
Abstract
The majority of visible mass of the universe is made up of atomic nuclei that lie at the centre of atoms. Nuclear physics seeks to answer fundamental questions such as: "How do the laws of physics work when driven to the extremes? What are the fundamental constituents and fabric of the universe and how do they interact? How did the universe begin and how is it evolving? What is the nature of nuclear and hadronic matter?" The aim of our research is to study and measure the properties of atomic nuclei and hot nuclear matter in order to answer these questions.
For exotic nuclear systems lying far from stability we will explore how the nucleus prefers to rearrange its shape, which can be a sphere, rugby ball, etc. and how it stores its energy among the possible degrees of freedom. We will study the properties of the very few cases where nuclei can assume the shape of a pear, that may be key in understanding why the universe has a matter-antimatter imbalance. We will explore in the region of the proton and neutron drip lines, which are the borders between bound and unbound nuclei and are relevant to understanding how atomic nuclei are synthesised in stars. Nuclei beyond the proton drip line have so much electrical charge that they are highly unstable and try to achieve greater stability through the process of proton emission. We will investigate how this process is affected by the nucleus' shape and structure, and make precision measurements of these fundamental properties using lasers. No one yet knows just how many neutrons and protons can be made to bind together. We will study the heaviest nuclei that can be made in the laboratory and determine their properties which will allow better predictions to be made for the "superheavies". We will also investigate how the properties of nuclei develop as we make them spin faster and faster, determining the precise nature of ultra-high spin states in heavy nuclei, just before the nucleus breaks up due to fission.
Nuclear matter can exist in different phases, analogous to the solid, liquid, gas and plasma phases in ordinary substances. By varying the temperature, density or pressure, nuclear matter can undergo a transition from one phase to another. In extreme conditions of density and temperature (about 100 thousand times more than the temperature at the heart of the sun!), a phase transition should occur and quarks and gluons (of which the protons and neutrons are made) should exist in a new state of matter called the Quark-Gluon Plasma. By colliding nuclei together at high energies at the Large Hadron Collider at CERN, we will study properties of this new state of matter. Such information is not only important for nuclear physics but also to understand neutron stars and other compact astrophysical objects.
This programme of research will employ a large variety of experimental methods to probe many aspects of nuclear structure and the phases of strongly interacting matter, mostly using instrumentation that we have constructed at several world-leading accelerator laboratories. The work will require a series of related experiments at a range of facilities in order for us to gain an insight into the answers to the questions posed above. These experiments will help theorists to refine and test their calculations that have attempted to predict the properties of nuclei and nuclear matter, often with widely differing results. The resolution of this problem will help us to describe complex many-body nuclear systems and better understand conditions in our universe a few fractions of a second after the big bang.
For exotic nuclear systems lying far from stability we will explore how the nucleus prefers to rearrange its shape, which can be a sphere, rugby ball, etc. and how it stores its energy among the possible degrees of freedom. We will study the properties of the very few cases where nuclei can assume the shape of a pear, that may be key in understanding why the universe has a matter-antimatter imbalance. We will explore in the region of the proton and neutron drip lines, which are the borders between bound and unbound nuclei and are relevant to understanding how atomic nuclei are synthesised in stars. Nuclei beyond the proton drip line have so much electrical charge that they are highly unstable and try to achieve greater stability through the process of proton emission. We will investigate how this process is affected by the nucleus' shape and structure, and make precision measurements of these fundamental properties using lasers. No one yet knows just how many neutrons and protons can be made to bind together. We will study the heaviest nuclei that can be made in the laboratory and determine their properties which will allow better predictions to be made for the "superheavies". We will also investigate how the properties of nuclei develop as we make them spin faster and faster, determining the precise nature of ultra-high spin states in heavy nuclei, just before the nucleus breaks up due to fission.
Nuclear matter can exist in different phases, analogous to the solid, liquid, gas and plasma phases in ordinary substances. By varying the temperature, density or pressure, nuclear matter can undergo a transition from one phase to another. In extreme conditions of density and temperature (about 100 thousand times more than the temperature at the heart of the sun!), a phase transition should occur and quarks and gluons (of which the protons and neutrons are made) should exist in a new state of matter called the Quark-Gluon Plasma. By colliding nuclei together at high energies at the Large Hadron Collider at CERN, we will study properties of this new state of matter. Such information is not only important for nuclear physics but also to understand neutron stars and other compact astrophysical objects.
This programme of research will employ a large variety of experimental methods to probe many aspects of nuclear structure and the phases of strongly interacting matter, mostly using instrumentation that we have constructed at several world-leading accelerator laboratories. The work will require a series of related experiments at a range of facilities in order for us to gain an insight into the answers to the questions posed above. These experiments will help theorists to refine and test their calculations that have attempted to predict the properties of nuclei and nuclear matter, often with widely differing results. The resolution of this problem will help us to describe complex many-body nuclear systems and better understand conditions in our universe a few fractions of a second after the big bang.
Planned Impact
Nuclear physics research and technology development has had a huge beneficial influence in our Society. Through low-carbon energy production, radiation detection for national security or environmental monitoring and cancer diagnosis and treatment in modern healthcare, the applications emerging from nuclear physics are numerous.
Recent high-profile scientific discoveries include:
- An electronic transition was located in nobelium, making Z=102 the heaviest element for which optical spectroscopy has been performed. This observation was published in Nature and we subsequently measured the ionisation potential with high precision and have begun to extract moments and radii of different isotopes (leading to 2 PRLs).
- Following the publication in Nature of its discovery that 224Ra is pear-shaped, the Liverpool group has now established that the radon isotopes 224Rn and 226Rn do not possess static pear shapes in their ground states, so they are not promising candidates to have measurable atomic electric dipole moments. This work was publicised in Nature Communications, CERN Courier, Phys.org, Science Daily and Scienmag.
- The presence of two different topologies in light Hg isotopes that coexist and mix at low excitation energy has been firmly established for the first time through our programme of complementary experiments. The laser spectroscopy results published in Nature Physics were compared with the largest Monte-Carlo shell model calculations ever performed, providing insights into the microscopic origins of shape coexistence.
- In a paper published in Nature Physics, the ALICE collaboration reported novel phenomena observed in proton collisions at the LHC. Until then enhanced strangeness production had been observed only in collisions of heavy nuclei, and was considered as a manifestation of the primordial state of matter called the quark-gluon plasma. ALICE's new and unexpected measurements indicate that this phenomenon may now have been observed in smaller and simpler systems as well. This discovery opens up an entirely new dimension for the investigation of the strongly-interacting matter from which our universe emerged.
The University of Liverpool has significant industrial engagement programmes that support knowledge exchange and the development of future REF returnable impact cases with a focus on nuclear measurement techniques and instrumentation. Industrial collaborators include AWE, Mirion, Kromek, Ametek, John Caunt Scientific, Metropolitan Police, MoD, National Nuclear Laboratory, Rapiscan, Sellafield Ltd. and a large number of NHS Trusts.
The University Department of Physics is one of only three national training providers for the Modernising Scientific Careers Clinical Science (Medical Physics) MSc, funded by the NHS. This provides a unique opportunity to build collaborative research and Continuing Professional Development partnerships within the Healthcare sector.
Beyond satisfying human curiosity around the workings of nature, pure research in nuclear physics has also tremendous societal impact. The University of Liverpool has an excellent track record in public engagement and outreach in a subject that has a natural fascination for the public. Indeed, it fulfils the important role of educating the public in nuclear radiation and its wider aspects, both positive and negative and is important to drive interest in the study of STEM subjects. Nuclear Physicists are frequently invited to share their knowledge and talk about their research at schools, science festivals and community groups.
The University of Liverpool hosts the state-of-the-art Central Teaching Laboratory (CTL) facility. The CTL has a dedicated laboratory for Nuclear Physics and radiation measurements. The CTL holds schools and outreach activities on a regular basis with University support, such as the Science Jamborees for 300 Cubs, Beavers and Brownies.
Recent high-profile scientific discoveries include:
- An electronic transition was located in nobelium, making Z=102 the heaviest element for which optical spectroscopy has been performed. This observation was published in Nature and we subsequently measured the ionisation potential with high precision and have begun to extract moments and radii of different isotopes (leading to 2 PRLs).
- Following the publication in Nature of its discovery that 224Ra is pear-shaped, the Liverpool group has now established that the radon isotopes 224Rn and 226Rn do not possess static pear shapes in their ground states, so they are not promising candidates to have measurable atomic electric dipole moments. This work was publicised in Nature Communications, CERN Courier, Phys.org, Science Daily and Scienmag.
- The presence of two different topologies in light Hg isotopes that coexist and mix at low excitation energy has been firmly established for the first time through our programme of complementary experiments. The laser spectroscopy results published in Nature Physics were compared with the largest Monte-Carlo shell model calculations ever performed, providing insights into the microscopic origins of shape coexistence.
- In a paper published in Nature Physics, the ALICE collaboration reported novel phenomena observed in proton collisions at the LHC. Until then enhanced strangeness production had been observed only in collisions of heavy nuclei, and was considered as a manifestation of the primordial state of matter called the quark-gluon plasma. ALICE's new and unexpected measurements indicate that this phenomenon may now have been observed in smaller and simpler systems as well. This discovery opens up an entirely new dimension for the investigation of the strongly-interacting matter from which our universe emerged.
The University of Liverpool has significant industrial engagement programmes that support knowledge exchange and the development of future REF returnable impact cases with a focus on nuclear measurement techniques and instrumentation. Industrial collaborators include AWE, Mirion, Kromek, Ametek, John Caunt Scientific, Metropolitan Police, MoD, National Nuclear Laboratory, Rapiscan, Sellafield Ltd. and a large number of NHS Trusts.
The University Department of Physics is one of only three national training providers for the Modernising Scientific Careers Clinical Science (Medical Physics) MSc, funded by the NHS. This provides a unique opportunity to build collaborative research and Continuing Professional Development partnerships within the Healthcare sector.
Beyond satisfying human curiosity around the workings of nature, pure research in nuclear physics has also tremendous societal impact. The University of Liverpool has an excellent track record in public engagement and outreach in a subject that has a natural fascination for the public. Indeed, it fulfils the important role of educating the public in nuclear radiation and its wider aspects, both positive and negative and is important to drive interest in the study of STEM subjects. Nuclear Physicists are frequently invited to share their knowledge and talk about their research at schools, science festivals and community groups.
The University of Liverpool hosts the state-of-the-art Central Teaching Laboratory (CTL) facility. The CTL has a dedicated laboratory for Nuclear Physics and radiation measurements. The CTL holds schools and outreach activities on a regular basis with University support, such as the Science Jamborees for 300 Cubs, Beavers and Brownies.
Organisations
Publications
Heery J
(2021)
Lifetime measurements of yrast states in $$^{\mathbf {178}}$$Pt using the charge plunger method with a recoil separator
in The European Physical Journal A
Acharya S
(2021)
? c + production in p p and in p -Pb collisions at s N N = 5.02 TeV
in Physical Review C
Acharya S
(2021)
Inclusive heavy-flavour production at central and forward rapidity in Xe-Xe collisions at s NN = 5.44 TeV
in Physics Letters B
Singh B.
(2021)
Extending the ALICE strong-interaction studies to nuclei: measurement of proton-deuteron correlations in pp collisions at vs = 13 TeV
in Proceedings of Science
Acharya S
(2021)
Jet-associated deuteron production in pp collisions at s = 13 TeV
in Physics Letters B
Acharya S
(2021)
Soft-Dielectron Excess in Proton-Proton Collisions at sqrt[s]=13 TeV.
in Physical review letters
Acharya S
(2021)
First measurement of the |t|-dependence of coherent J/? photonuclear production
in Physics Letters B
Harding R
(2021)
Laser-assisted nuclear decay spectroscopy of Au 176 , 177 , 179
in Physical Review C
Acharya S
(2021)
First measurement of coherent ?0 photoproduction in ultra-peripheral Xe-Xe collisions at s NN = 5.44 TeV
in Physics Letters B
Caffrey A
(2021)
Gamma-ray imaging performance of the GRI+ Compton camera
in Journal of Instrumentation
Zheng K
(2021)
Rich band structure and multiple long-lived isomers in the odd-odd Cs 118 nucleus
in Physical Review C
Yakushev A
(2021)
First Study on Nihonium (Nh, Element 113) Chemistry at TASCA.
in Frontiers in chemistry
Andel B
(2021)
New ß -decaying state in Bi 214
in Physical Review C
Acharya S
(2021)
? K femtoscopy in Pb-Pb collisions at s N N = 2.76 TeV
in Physical Review C
Reponen M
(2021)
Evidence of a sudden increase in the nuclear size of proton-rich silver-96.
in Nature communications
Malbrunot-Ettenauer S
(2021)
Nuclear Charge Radii of the Nickel Isotopes $^{58-68,70}$Ni
Zhang W
(2021)
Identification of excited states in Te 55 52 107
in Physical Review C
Acharya S
(2021)
Pion-kaon femtoscopy and the lifetime of the hadronic phase in Pb-Pb collisions at s NN = 2.76 TeV
in Physics Letters B
Acharya S
(2021)
Charged-particle multiplicity fluctuations in Pb-Pb collisions at $$\sqrt{s_{\mathrm {NN}}}$$ = 2.76 TeV
in The European Physical Journal C
Zheng K
(2021)
Evidence of oblate-prolate shape coexistence in the strongly-deformed nucleus 119Cs
in Physics Letters B
Acharya S
(2021)
Centrality dependence of J/? and ?(2S) production and nuclear modification in p-Pb collisions at $$ \sqrt{s_{\mathrm{NN}}} $$ = 8.16 TeV
in Journal of High Energy Physics
Acharya S
(2021)
$$\mathrm {K_S}^{0}$$- and (anti-)$$\Lambda $$-hadron correlations in pp collisions at $${\sqrt{s}} = 13$$ TeV
in The European Physical Journal C
Acharya S
(2021)
? production and nuclear modification at forward rapidity in Pb-Pb collisions at s NN = 5.02 TeV
in Physics Letters B
Acharya S
(2021)
?_{c}^{+} Production and Baryon-to-Meson Ratios in pp and p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV at the LHC.
in Physical review letters
Zheng K
(2021)
Complete set of proton excitations in Cs 119
in Physical Review C
Liu X
(2021)
Evidence for enhanced neutron-proton correlations from the level structure of the N = Z + 1 nucleus Tc 44 43 87
in Physical Review C
Brunet M
(2021)
Competition between allowed and first-forbidden ß decays of At 208 and expansion of the Po 208 level scheme
in Physical Review C
Acharya S
(2021)
Production of light-flavor hadrons in pp collisions at $$\sqrt{s}~=~7\text { and }\sqrt{s} = 13 \, \text { TeV} $$
in The European Physical Journal C
Acharya S
(2021)
Elliptic Flow of Electrons from Beauty-Hadron Decays in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV.
in Physical review letters
Barzakh A
(2021)
Large Shape Staggering in Neutron-Deficient Bi Isotopes.
in Physical review letters
Heylen H
(2021)
High-resolution laser spectroscopy of Al 27 - 32
in Physical Review C
Acharya S
(2021)
Kaon-proton strong interaction at low relative momentum via femtoscopy in Pb-Pb collisions at the LHC
in Physics Letters B
Acharya S
(2021)
Transverse-momentum and event-shape dependence of D-meson flow harmonics in Pb-Pb collisions at s NN = 5.02 TeV
in Physics Letters B
Fernández A
(2021)
Reinterpretation of excited states in Po 212 : Shell-model multiplets rather than a -cluster states
in Physical Review C
Stolze S
(2021)
Single-particle and collective excitations in the transitional nucleus 166 Os
in Journal of Physics G: Nuclear and Particle Physics
Acharya S
(2021)
Energy dependence of $$\phi $$ meson production at forward rapidity in pp collisions at the LHC
in The European Physical Journal C
ALICE Collaboration
(2021)
Publisher Correction: Unveiling the strong interaction among hadrons at the LHC.
in Nature
Bhattacharyya A
(2021)
Neutron capture cross sections of light neutron-rich nuclei relevant for r -process nucleosynthesis
in Physical Review C
Hall O
(2021)
ß-delayed neutron emission of r-process nuclei at the N = 82 shell closure
in Physics Letters B
Schneider A.
(2021)
Thin SI Sensors on Flexible Printed Circuits - Study of Two Bond Methods
in 2021 23rd European Microelectronics and Packaging Conference and Exhibition, EMPC 2021
Acharya S
(2021)
Experimental Evidence for an Attractive p-? Interaction.
in Physical review letters
Zheng K
(2021)
Neutron excitations in Ba 119
in Physical Review C
Acharya S
(2021)
Inclusive $$\text {J}/\psi $$ production at midrapidity in pp collisions at $$\sqrt{s} = 13$$ TeV
in The European Physical Journal C
Acharya S
(2021)
ALICE Collaboration
in Nuclear Physics A
Piersa-Silkowska M
(2021)
First ß -decay spectroscopy of In 135 and new ß -decay branches of In 134
in Physical Review C
Koszorús Á
(2021)
Proton-neutron pairing correlations in the self-conjugate nucleus 42Sc
in Physics Letters B
Goigoux T
(2021)
First observation of high-K isomeric states in $$^{249}$$Md and $$^{251}$$Md
in The European Physical Journal A
Acharya S
(2021)
Production of muons from heavy-flavour hadron decays at high transverse momentum in Pb-Pb collisions at s NN = 5.02 and 2.76 TeV
in Physics Letters B
Acharya S
(2021)
Multiharmonic Correlations of Different Flow Amplitudes in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV.
in Physical review letters
Title | ISOLDE Solenoidal Spectrometer Sort Code |
Description | A code to read and process the raw data from the ISOLDE Solenoidal Spectrometer experiment at CERN. It builds physics events and performs correlations, producing a range of histograms for the user. |
Type Of Material | Data analysis technique |
Year Produced | 2021 |
Provided To Others? | Yes |
Impact | First experiments of ISOLDE Solenoidal Spectrometer use this code for the online data viewing and offline analysis. |
URL | https://github.com/ISOLDESolenoidalSpectrometer/ISSSort |
Title | Miniball Sort Code for new FEBEX DAQ |
Description | A code to process the raw data from the new Miniball FEBEX DAQ and build time correlated events. In the end it also produces a range of physics histograms for the user to do the analysis. |
Type Of Material | Data analysis technique |
Year Produced | 2022 |
Provided To Others? | Yes |
Impact | First test data of the new Miniball DAQ is being processed and visualised with this code. |
URL | https://github.com/Miniball/MiniballSort |
Description | Binding Blocks Summer Masterclass Webinar |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Schools |
Results and Impact | A webinar about experimental nuclear physics and studying exotic isotopes at the summer masterclass with the Binding Blocks team |
Year(s) Of Engagement Activity | 2022 |
URL | https://sites.google.com/york.ac.uk/bindingblocks/pre-16/ |
Description | Binding Blocks Winter Masterclass Webinar |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Schools |
Results and Impact | A webinar about experimental nuclear physics and studying exotic isotopes at the winter masterclass with the Binding Blocks team |
Year(s) Of Engagement Activity | 2022 |
URL | https://sites.google.com/york.ac.uk/bindingblocks/post-16/webinars-winter-202223 |
Description | I'm a Scientist, Get Me Out Of Here (CERN Zone) |
Form Of Engagement Activity | Engagement focused website, blog or social media channel |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Schools |
Results and Impact | I am leader of the ISOLDE Team in the CERN Zone of I'm A Scientist Get Me Out Of Here, which directly engages Y10-13 students in online chats, Q&A forums, laboratory updates/tours, etc. |
Year(s) Of Engagement Activity | 2022,2023 |
URL | https://cern22.imascientist.org.uk/team/isolde |