A network of clocks for measuring the stability of fundamental constants
Lead Research Organisation:
University of Sussex
Department Name: Sch of Mathematical & Physical Sciences
Abstract
We propose to create a world-leading programme to search for spatial and temporal variations of fundamental constants of nature, using a network of quantum clocks. Our consortium will build a community that will achieve unprecedented sensitivity in testing variations of the fine structure constant, alpha, and the proton-to-electron mass ratio, mu. This in turn will provide more stringent constraints on a wide range of fundamental and phenomenological theories beyond the Standard Model and on dark matter models. The ambition of the QSNET consortium will be enabled by a unique experimental platform that connects a number of complementary quantum sensors across the UK, namely state-of-the-art atomic clocks, molecular clocks, and a highly-charged ion clock. Key to the proposal is the networked approach in which clocks, with different sensitivities to changes of the fundamental constants, will be linked using optical fibres. The network involves a range of different quantum sensing devices and devices with different technology readiness levels: from the more established microwave atomic clocks on the one end to the highly-charged ion clock on the other. QSNET will be able to deliver important results in the first years, and at the same time develop advanced quantum sensors to provide increasingly impactful results as the project continues and the most sophisticated sensors come on line.
Planned Impact
QSNET will use quantum technologies to investigate fundamental physics, contributing to an area of research that is growing considerably in both relevance and scope. The search for physics beyond the Standard Model is an expanding field with huge potential for new discoveries. Our consortium will deliver results that are relevant in the fields of cold atoms and molecules, light matter interaction, optical communications, plasma and lasers, quantum device components and systems, quantum optics and information, particle physics, particle astrophysics, astrobiology, theoretical and phenomenological physics and will have a substantial impact on the expanding national and international academic community working on the whole range of these topics.
The dissemination of our results to the academic community will be mainly through high-impact scientific publications, seminars, talks and the organisation of a workshop. The academic community, as well as the general public, will also be informed about our progress by means of social media and a project-dedicated website. Additionally, we will showcase our ideas in public events.
The proposed project will contribute to developing the next generation of quantum technology, thus moving forward the frontiers for future applications. In this respect, the combination of technological solutions originating in quantum physics, gravitational wave detection, metrology and particle physics represents a unique opportunity for delivering impactful innovation. For this reason, we will exploit our connection with the QT Hubs and the national industries interested in quantum technology towards the concrete application of our ideas and methods and the securing of industrial patents.
By tackling new questions at the crossroad of many thematic areas, QSNET will contribute to the growth of the early stage researchers who will work on it. The recruited PDRAs will enlarge their technical toolboxes and sharpen the tools within while the PhD students will develop a large set of skills. They will work on unexplored problems that hold the promise of delivering long lasting breakthroughs. QSNET will thus help them develop experimental, analytical and numerical expertise that will be applicable in many professional contexts (from academia to finance and industry), thus propelling them to the next phase of their careers.
The dissemination of our results to the academic community will be mainly through high-impact scientific publications, seminars, talks and the organisation of a workshop. The academic community, as well as the general public, will also be informed about our progress by means of social media and a project-dedicated website. Additionally, we will showcase our ideas in public events.
The proposed project will contribute to developing the next generation of quantum technology, thus moving forward the frontiers for future applications. In this respect, the combination of technological solutions originating in quantum physics, gravitational wave detection, metrology and particle physics represents a unique opportunity for delivering impactful innovation. For this reason, we will exploit our connection with the QT Hubs and the national industries interested in quantum technology towards the concrete application of our ideas and methods and the securing of industrial patents.
By tackling new questions at the crossroad of many thematic areas, QSNET will contribute to the growth of the early stage researchers who will work on it. The recruited PDRAs will enlarge their technical toolboxes and sharpen the tools within while the PhD students will develop a large set of skills. They will work on unexplored problems that hold the promise of delivering long lasting breakthroughs. QSNET will thus help them develop experimental, analytical and numerical expertise that will be applicable in many professional contexts (from academia to finance and industry), thus propelling them to the next phase of their careers.
Organisations
Publications
Abt I
(2023)
Search for effective Lorentz and C P T violation using ZEUS data
in Physical Review D
Abt I
(2023)
Measurement of jet production in deep inelastic scattering and NNLO determination of the strong coupling at ZEUS
in The European Physical Journal C
Antonelli T
(2025)
The weak gravity conjecture in the Vilkovisky-DeWitt effective action of quantum gravity
in Physics Letters B
Barontini G
(2022)
Measuring the stability of fundamental constants with a network of clocks
Barontini G
(2021)
Measuring the stability of fundamental constants with a network of clocks
Barontini G
(2022)
Measuring the stability of fundamental constants with a network of clocks
in EPJ Quantum Technology
Belyaev A
(2024)
Probing CPT Invariance with Top Quarks at the LHC.
in Physical review letters
Calmet X
(2024)
Quo Vadis Particula Physica?
in Entropy
| Title | "Additional table 1" of "Measurement of jet production in deep inelastic scattering and NNLO determination of the strong coupling at ZEUS" |
| Description | Double-differential inclusive-jet cross sections using the alternative treatment of QED radiation, as explained in the accompanying thesis (section 9.5.3 and table C.7) and arXiv:2405.18136. The alternative treatment affects the central value of the cross sections, $\sigma$, the QED correction factors $c_\text{QED}$ and their uncertainty and the sum of all uncorrelated uncertainties $\delta_\text{uncor}$. All other uncertainties and corrections are identical to Tables 1 and 2 and should be taken from there. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| URL | https://www.hepdata.net/record/153725 |
| Title | "Figure 10" of "Measurement of jet production in deep inelastic scattering and NNLO determination of the strong coupling at ZEUS" |
| Description | Value of the strong coupling $\alpha_s(\mu^2)$ as a function of the scale $\mu$. The data points indicate determinations from measurements that were performed close to the indicated scale. The uncertainties represent the full uncertainty of each determination. All depicted results were obtained at least at NNLO. They are based on data from $e^+e^-$, $ep$ and $pp$ collisions, as well as from $\tau$ lepton decays and quarkonium states. The solid blue line shows the PDG world average. Also shown are the $\alpha_s(M_Z^2)$ values corresponding to each data point. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| URL | https://www.hepdata.net/record/153724 |
| Title | "Figure 7" of "Measurement of jet production in deep inelastic scattering and NNLO determination of the strong coupling at ZEUS" |
| Description | Summary of different determinations of $\alpha_s(M_Z^2)$ at NNLO or higher order, adapted from PDG, see references therein. The red points are included in the PDG world average. The averages from each sub-field are shown as yellow bands and the world average as a blue band. A recent measurement from CMS using jet cross sections and the latest determination from HERAPDF, which are not yet included in the world average, are shown in green. The current determination, assuming half-correlated and half-uncorrelated scale uncertainties, is shown in black. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| URL | https://www.hepdata.net/record/146650 |
| Title | "Table 1" of "Measurement of jet production in deep inelastic scattering and NNLO determination of the strong coupling at ZEUS" |
| Description | Note: in the paper, uncertainties are given in percent. The HEPData table contains absolute numbers. The original data file, containing relative uncertainties as in the paper, is available via the 'Resources' button above. Double-differential inclusive-jet cross sections, $\sigma$. Also listed are the unfolding uncertainty $\delta_\text{unf}$, the sum of the uncorrelated systematic uncertainties $\delta_\text{uncor}$ and the correlated systematic uncertainties associated with the jet-energy scale $\delta_\text{JES}$, the MC model $\delta_\text{model}$, the relative normalisation of the background from unmatched detector-level jets $\delta_\text{fake}$, the relative normalisation of the background from low-$Q^2$ DIS events $\delta_\text{Low-$Q^2$}$, the $(E-p_\text{Z})$-cut boundaries $\delta_{E-p_\text{Z}}$, the track-matching-efficiency correction $\delta_\text{TME}$. Uncertainties for which a single number is listed should be taken as symmetric in the other direction. Not listed explicitly is the luminosity uncertainty of $1.9\%$, which is fully correlated across all points. The last four columns show the QED Born-level correction $c_\text{QED}$ that has been applied to the data as well as the $Z$, $c_Z$, and hadronisation correction $c_\text{Had}$ and associated uncertainty that need to be applied to the theory predictions. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| URL | https://www.hepdata.net/record/153719 |
| Title | "Table 2" of "Measurement of jet production in deep inelastic scattering and NNLO determination of the strong coupling at ZEUS" |
| Description | Note: in the paper, uncertainties are given in percent. The HEPData table contains absolute numbers. The original data file, containing relative uncertainties as in the paper, is available via the 'Resources' button above. Breakdown of the uncorrelated uncertainty $\delta_\text{uncor}$ from Table 1. Shown are the uncertainties associated with the reweighting of the MC models ($\delta_\text{rew.}$), the electron-energy scale ($\delta_\text{EES}$), the electron-finding algorithm ($\delta_\text{EM}$), the electron calibration ($\delta_\text{EL}$), the variation of the $p_{T,\text{lab}}$ cut of the jets ($\delta_{p_T}$), the variation of the electron-track momentum-cut boundaries ($\delta_\text{trk.}$), the variation of the $p_T/\sqrt{E_T}$-cut boundaries ($\delta_\text{bal.}$), the variation of the $Z_\text{vertex}$-cut boundaries ($\delta_\text{vtx.}$), the variation of the $R_\text{RCAL}$-cut boundaries ($\delta_\text{rad.}$), the variation of the electron-track distance-cut boundaries ($\delta_\text{DCA}$), the relative normalisation of the background from photoproduction events ($\delta_\text{PHP}$), the polarisation correction ($\delta_\text{pol.}$), the FLT track-veto-efficiency correction ($\delta_\text{FLT}$) and the correction to QED Born-level ($\delta_\text{QED}$). For the asymmetric uncertainties, the upper number corresponds to the upward variation of the corresponding parameter and the lower number corresponds to the downward variation. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| URL | https://www.hepdata.net/record/146647 |
| Title | "Table 3a" of "Measurement of jet production in deep inelastic scattering and NNLO determination of the strong coupling at ZEUS" |
| Description | Correlation matrix of the unfolding uncertainty within the inclusive-jet cross-section measurement. Correlations are given in percent. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| URL | https://www.hepdata.net/record/146648 |