High Energy Physics. Theoretical and Experimental Challenges.
The topics of the workshop:
Predictions, Observations, Challenges:
Relativistic collisions of Hadrons. Dense and Hot matter. Phase transitions.
New physics signatures. Multi-differential production cross-sections.
Hadronization. Mass generation. Current and Near future. Challenges
HEP techniques applications
The workshop will consist of invited and contributed talks.
The invited talks will introduce the proposed contribution of the Ukraine into the European Strategy in Partcle Physics (ESPP).
Contributed talks will provide an opportunity for researchers to present the achieved results as well as an outlook on challenges and ways of their possible solution.
Over the last five decades, many outstanding questions in particle physics have been answered, leading to the Standard Model (SM) and its spectacular confirmation with the discovery of the Higgs boson in 2012, which would supply the heart to this theory. Now the hunt is on for a deeper theory of reality. To answer this question, Europe, Japan, the US and China have proposed plans for building new particle colliders focused on studying the Higgs boson. Higgs’ legacy will be the experimental particle physics programme of the 21st century. The open questions of today are just as profound as they were a century ago. However, there appears to be many more of them. Recent discoveries of the Higgs boson and Gravitational waves required increasingly sophisticated instrumentation and have created an exceptionally positive environment in society. Thus, we have a “virtuous cycle” which must remain strong and un-broken – laws of nature enable novel detector and accelerator concepts, which in turn lead to a greater physics discoveries and better understanding of our Universe.
Particle physics is now entering a new era. As the scale and the cost of the frontier colliders increases, while the timescale for projects is becoming longer, fewer facilities can be realized. Moreover, several high-energy physics (HEP) laboratories becoming multi-purpose ones. The pursuit of ever-higher energies will surely be one of the future directions of particle physics; the course will depend on whether one can continue to contain the cost of future colliders in the current worldwide environment. We must take a holistic view of particle physics - whether we find Beyond Standard Model physics at the LHC or not - and select the path to follow in a prudent manner, while maintaining HEP accelerator laboratories and expertize in all regions. Our culture and management structure must evolve to confront these challenges.
Until 1993, the Kharkiv Institute of Physics and Technology was the largest scientific center in Ukraine where nuclear physics research was conducted using beams of γ-quanta, electrons, protons, and other charged particles. The institute had a number of unique accelerator facilities: the largest linear accelerators in Europe, LU-2000 and LU-300, the H-100 storage facility, and a number of lower energy accelerators. A large team of highly qualified specialists in nuclear and accelerator physics was formed at the institute. After 1993, the production of klystrons for our accelerators was eliminated in Russia, and large accelerator facilities were shut down and it was impossible to resume their operation. Experimental work, which is the basis of nuclear physics research, practically stopped, and researchers were forced to transfer their research to other facilities outside Ukraine or retrain. The absence of “live” work primarily led to the outflow of young specialists from this field of research and the aging of personnel.
Currently, there are only four electron accelerators in Ukraine: the 10 MeV LU-10 technological accelerator, the 30 MeV LU-30 accelerator, the LU-40 accelerator at KIPT, which were restored after damage, and the 25 MeV M-30 microtron at the Institute of Electron Physics, National Academy of Sciences of Ukraine, Uzhhorod.
In connection with this, it became necessary to create a new state program for the development of fundamental and applied nuclear physics research using accelerators and electron storage facilities, as well as a multifunctional accelerator complex for its implementation, which were emphasized in 2022 in [1,2].
In 2023, a monograph was published [3], which outlined the concept of the complex. This conceptual project was based on the ideas for the development of accelerator technologies laid down in the European Strategy for Particle Physics - Accelerator R&D Roadmap [4]. The strategy is a roadmap for the development of accelerators in Europe in the next 5-10 years. These accelerator technologies may be used in the future in the implementation of the FCC(hh) project.
A general view of the recirculator, which is the basis of the accelerator complex, is shown in Figure 1. The beam with a maximum energy of 560 MeV can be used for nuclear physics research and studies of interaction with crystal structures. This beam can also be injected into a storage ring, a source of synchrotron radiation, and used in a free-electron laser. The beam output channels with energy of 380 and 210 MeV make it possible to conduct nuclear physics research and create a pulsed neutron source. Applied research using the interaction of electrons and positrons can be performed on beam output channels with a maximum energy of 29 MeV. In subsequent publications [5-8], the main characteristics of electron, positron, and neutron beams on the output channels to physical facilities were considered.
Taking into account that almost all accelerator specialists in Ukraine are currently concentrated at KIPT, there is hope that, with the necessary funding, the complex can be created in a short time on the basis of the latest accelerator technologies with a phased launch of the facility. The work of the Faculty of Physics and Technology at the KIPT will allow to involve teachers, graduate students and students of the Faculty in the creation of the facility.
Representatives of KIPT participated in the development of positron beam injection systems in the CLIC, ILC, and FCC projects [9,10], but it is impossible to predict the participation of our scientists in the development of these accelerators in the future without the revival of the technical base of nuclear physics research in Ukraine and, on its basis, the school of specialists in high-energy physics, nuclear physics, and accelerators.
Figure 1
In the framework of physics beyond the Standard Model, an experiment is presented to search for a chiral graviton mode. These particles were found in a special type of liquid that behaves in a special way under the influence of a magnetic field. Studying the properties of graviton modes will provide an opportunity to understand quantum gravity.
To study gravitational modes, inelastic scattering of photons is considered, modeled using microscopic theory with Hamiltonians at different filling factors [1]. A common feature of fractional quantum Hall (FQH) fluids is multiple graviton modes (GMs) in different subspaces in one Landau level (LL). The number of observed GMs is dynamical and meaningful for specific interaction Hamiltonians. Each GM can be interpreted as the null spaces of model Hamiltonians within one LL.
Our goal is to present the geometric origin of GM and the hierarchical structure of conformal Hilbert spaces as null spaces of model Hamiltonians. We then introduce K-group theory to identify each set of GM excitations, which leads to a topological explanation of the emergence of multiple GM.
We’ll use the following Hamiltonian
$$\hat{H}=\sum_1^N\frac{1}{2m}\bar{g}^{ab}{\hat{\pi}}_{ia}{\hat{\pi}}_{ib}+\hat{V}_{int},$$
where
$${\hat{\pi}}_{ia}={\hat{p}}_{ia}+e{\hat{A}}_{ia}$$ the dynamical momentum operator of the i-th electron, $A_i$ is the external vector potential, connected with magnetic field by formula $B=\epsilon^{ab}\partial_a A_{ib}$. $V_{int}$ describes the dynamics only within a single LL, the magnetic length is $l_B=\sqrt{\frac{1}{e}B}$. The Hilbert space of a single LL, referred to as the lowest LL (LLL), is parametrized by the metric $\bar{g}_{ab}$, which leads to density modes in higher LLs, known as “cyclotron gravitons".
The Hilbert spaces like LLL are called conformal Hilbert spaces (CHSs) as they are generated by the conformal operators like the Virasoro algebra, known as the Virasoro constraint in string theory, applied only on the physical states. Such CHSs are built up with quasiparticles.
We can use the apparatus of the K-group for calculation of Hilbert space states of charged particles for explanation of the FQHE, which are topological phases of LLLs. Since we are dealing with four types of interaction, it is appropriate to use the apparatus of vector bundles to describe a complex formation of D-brane type. B-field interacting with D-branes can be taken into account through the Dixmier-Douady invariant, which characterizes the bundles and describes the strength of the Neveu-Schwarz B-field interacting with D-branes. D-branes are topological solitons whose charges are described by Grothendieck K-groups. Reduction of twisted K-groups to an exact sequence of the form
$$0\rightarrow Z\rightarrow Z\rightarrow Z_n\rightarrow 0$$
leads to the result
$$K_0(S^3, n[H])=Z_n .$$
This group value determines the topological charges of the D6-brane in the presence of the Neveu-Schwarz -field [2].
Celebrating the 70th Anniversary of the CERN KINR Team enjoys the “PAST, PRESENT and FUTURE” horizons of its eclusive data, p scientific life participating at CERN, taking and analyzing construction and upgrade activities of the experimental setups with a clear roadmap to the end of this century!
In this report, we present KINR activity at CERN with emphasis on LHCb Collaboration.
LHCb (KINR since 1995 – 21 researchers)
Unconventional baryonic and mesonic states represent a topical issue in contemporary hadron physics. New results from the charm-quark sector indicate the existence of multi-quark objects beyond the quark-antiquark and 3-quark configurations (mesons and baryons) known from particle physics textbooks, which reveal themselves through unexpectedly narrow structures in energy. They are interpreted as configurations of minimal four or five (anti-) quarks, hence termed tetra- and pentaquarks. It’s an open question whether such structures are bound through gluon exchange, i.e. color interaction in the sense of the Standard Model of Particle Physics, or merely represent molecule-like bindings of meson-meson or meson-baryon similar to the binding of nucleons in atomic nuclei. To date investigations were mostly focused on the sector of c and b quarks, but in order to understand whether the newly discovered structures represent a general feature of structure formation from the basic building blocks of matter, quarks and gluons, also the light uds-quark sector is now attracting increasing attention.
The BGOOD photoproduction experiment [1] accesses forward meson angles and low momentum exchange kinematics in the uds sector, which may be sensitive to molecular-like hadron structure.
γn→K0Σ0 differential cross section measured at BGOOD is shown in Fig. 1. The data are in reasonable agreement with the previous data from the A2 collaboration [2] and in the more forward interval shown, are consistent with the predicted peak from the model of Ramos and Oset. This model suggested a dynamically generated N∗(2030) is the origin of a cusp measured in the K0Σ+ channel [3, 4]. The model also predicted constructive interference in K0Σ0 photoproduction resulting in a peak. Observing this experimentally would therefore be direct evidence of a molecular state in the uds sector [5].
Fig. 1. γn→K0Σ0 differential cross section for 0.2 < cosθKCM< 0.5 and two different fitting methods (red triangles and black circles). The blue squares are data from the A2 Collaboration [2]. The predicted total cross section from Ramos and Oset [4] is included at an arbitrary scale. Figure adapted from Ref. [6].
1. S. Alef, et al. (BGOOD Collaboration), Eur. Phys. J. A 57 80 (2021)
2. C. S. Akondi et al. (A2 Collaboration), Eur. Phys. J. A 55 202 (2019)
3. R. Ewald et al. (Crystal-Barrel@ELSA Collaboration), Phys. Lett. B 713 180 (2012)
4. A. Ramos and E. Oset, Phys. Lett. B 727 287 (2013)
5. T.Jude, et al. (BGOOD Collaboration), EPJ Web of Conferences 303, 01015 (2024)
6. K. Kohl, T. C. Jude, et al. (BGOOD Collaboration), Eur. Phys. J. A 59 254 (2023)
In this report, we present KINR proposal to “European Strategy for Particle Physics” (ESPP. 3d Update). https://europeanstrategy.cern/ The preliminary version was submitted after discussion held on-line on the 28th October 2024 Meeting of the Ukrainian Researchers“ devoted to Contribution to the European Strategy for Particle Physics”.
The modernized LHCb detector [1] provides a data set for luminosities in proton-proton collisions up to 2 × 1033 cm-2s-1 and at energies up to 13.6 TeV. Monitoring of the luminosity, beam and background control is necessary to ensure the safe operation of the experiment. To meet these needs, the Institute for Nuclear Research of the National Academy of Sciences of Ukraine created the RMS-R3 radiation monitoring system based on metal foil detectors [2] (an original development of the NAS) and the phenomenon of secondary electron emission.
The Radiation Monitoring System for Run3 (RMS-R3) has been operating as the part of the LHCb detector (CERN) since the end of 2021 [3]. The main tasks of RMS-R3 are to control the luminosity region and background, as well as conditions of the experiment. Intelligent design and geometric arrangement of the RMS-R3 modules in the LHCb experiment enable the precise measurement of proton beams collision region or fixed target nucleus positions with impact of the background. At present, only the monitoring of the relative luminosity at the experiment is carried out online by RMS-R3.
In the control structure of the experiment, the RMS-R3 system measures the frequency of collider beam interactions in a completely independent manner and displays this data on the monitoring screen in the LHCb control center. Using absolute calibration with the PLUME system [4], the RMS-R3 provides duplication of the online luminosity measurement, which is critical for continuous luminosity balancing within acceptable limits (±5%), which is implemented at LHCb by a feedback scheme with the LHC control center.
This work discusses the main results of RMS_R3 in the LHCb experiment: from luminosity measurements to the use of the asymmetry method, as well as comparisons with other beam and background systems (PLUME, VELO, etc.).
The work on the development of software for the RMS-R3 system in ECS, the WinCC-based LHCb control system, and in MONET, the LHCb web-based data quality monitoring system, is aimed at providing online monitoring of instantaneous luminosity, changing the position of the interaction region with precision accuracy and distinguishing between experimental conditions, etc. The advantage of these software solutions is the creation of new tools for LHCb operators and the full integration of the RMS-R3 system into the structure of monitoring the experimental conditions.
Acknowledgements
This work has received funding through the EURIZON project, which is funded by the European Union under grant agrement No.871072. Grant #3014.
[1] The LHCb Upgrades for Run3 and Run4. F. Alessio, CERN on behalf of the LHCb Collaboration. ICHEP. – 2020. – Prague. 28 July 2020 to 06 August 2020. Mode of access: URL: https://indico.cern.ch/event/868940/contributions/3813743/attachments/2081057/3495477/200725_ICHEP_LHCbUpgrades_v3.pdf
[2] V. Pugatch et al., Metal Foil Detectors and their applications. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. Volume 535, Issues 1–2, 11 December 2004, Pages 566-569
[3] LHCb collaboration. The LHCb upgrade I. – 2023.
[4] E. Graverini. Luminosity at LHCb in Run 3. In: PoS(ICHEP2022). Proc. of the 41st Int. Conf. on High Energy Physics – ICHEP2022. Bologna, Italy, July 6-13, 2022 (Bologna, 2022). p.679.
One of the important problems of accelerator physics is the problem of deflecting the direction of motion of high-energy charged particles. One of the options for solving this problem is to use thin bent crystals, passing through which the particles change their direction of motion. This occurs when the particles enter the crystal at a small angle to one of the main crystallographic axes or planes. In this case, the impact parameter of the particle interaction with neighboring crystal atoms changes slowly and coherent effects appear in the scattering of the particle by these atoms. Due to this coherence, it is possible to achieve deflection of the particle in a given direction through interactions with atomic strings or planes. The bending of the crystal in certain cases significantly increases the deflection angles of particles. In particular, if a particle moves in a bent crystal in the planar channeling mode [1,2], it can be deflected by an angle significantly exceeding the critical angle of planar channeling [3]. In addition to planar channeling, there are two other mechanisms for deflecting charged particles in a bent crystal: volume reflection of particles [4], when particles perform above-barrier motion relative to atomic planes in a bent crystal, and the Greenenko-Shul’ga mechanism [5], in which particles enter the crystal at a small angle to one of the crystal axes and move in above-barrier mode in the field of the crystal atomic strings.
All three mentioned mechanisms for deflecting high-energy charged particles using bent crystals have been successfully confirmed experimentally, including at CERN. In particular, the deflection of protons with energies around 7 TeV using planar channeling in a bent crystal was successfully demonstrated in experiments at the Large Hadron Collider [6,7]. This report analyzes the feasibility of using bent crystals for collimating charged particle beams in accelerators and for extracting part of the beam into separate channels.