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11,161 results on '"Malyshev, A."'

1. High-Statistics Measurement of the Cosmic-Ray Electron Spectrum with H.E.S.S

Author

Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaoui, M., Brose, R., Brown, A., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Collins, T., Cotter, G., Mbarubucyeye, J. Damascene, Devin, J., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Ernenwein, J. -P., Fegan, S., Feijen, K., Fontaine, G., Funk, S., Gabici, S., Gallant, Y. A., Glicenstein, J. F., Glombitza, J., Grolleron, G., Heß, B., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzynski, K., Kerszberg, D., Khatoon, R., Khelifi, B., Kluzniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Luashvili, A., Mackey, J., Malyshev, D., Marandon, V., Marinos, P., Marti-Devesa, G., Marx, R., Meyer, M., Mitchell, A., Moderski, R., Moghadam, M. O., Mohrmann, L., Montanari, A., Moulin, E., de Naurois, M., Niemiec, J., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, D., Pensec, U., Peron, G., Pühlhofer, G., Punch, M., Quirrenbach, A., Ravikularaman, S., Regeard, M., Reimer, A., Reimer, O., Reis, I., Ren, H., Reville, B., Rieger, F., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Sharma, A., Sol, H., Spencer, S., Stawarz, L., Steinmassl, S., Steppa, C., Suzuki, H., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Tsirou, M., van Eldik, C., Vecchi, M., Venter, C., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., and Zywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Owing to their rapid cooling rate and hence loss-limited propagation distance, cosmic-ray electrons and positrons (CRe) at very high energies probe local cosmic-ray accelerators and provide constraints on exotic production mechanisms such as annihilation of dark matter particles. We present a high-statistics measurement of the spectrum of CRe candidate events from 0.3 to 40 TeV with the High Energy Stereoscopic System (H.E.S.S.), covering two orders of magnitude in energy and reaching a proton rejection power of better than $10^{4}$. The measured spectrum is well described by a broken power law, with a break around 1 TeV, where the spectral index increases from $\Gamma_1 = 3.25$ $\pm$ 0.02 (stat) $\pm$ 0.2 (sys) to $\Gamma_2 = 4.49$ $\pm$ 0.04 (stat) $\pm$ 0.2 (sys). Apart from the break, the spectrum is featureless. The absence of distinct signatures at multi-TeV energies imposes constraints on the presence of nearby CRe accelerators and the local CRe propagation mechanisms., Comment: main paper: 8 pages, 4 figures, supplemental material: 12 pages, 14 figures, accepted for publication in Physical Review Letters https://journals.aps.org/prl/

Published
2024

2. Search for the X17 particle in $^{7}\mathrm{Li}(\mathrm{p},\mathrm{e}^+ \mathrm{e}^{-}) ^{8}\mathrm{Be}$ processes with the MEG II detector

Author

The MEG II collaboration, Afanaciev, K., Baldini, A. M., Ban, S., Benmansour, H., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Corvaglia, A., Maso, G. Dal, De Bari, A., De Gerone, M., Barusso, L. Ferrari, Francesconi, M., Galli, L., Gallucci, G., Gatti, F., Gerritzen, L., Grancagnolo, F., Grandoni, E. G., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Ignatov, F., Ikeda, F., Iwamoto, T., Karpov, S., Kettle, P. -R., Khomutov, N., Kolesnikov, A., Kravchuk, N., Krylov, V., Kuchinskiy, N., Leonetti, F., Li, W., Malyshev, V., Matsushita, A., Meucci, M., Mihara, S., Molzon, W., Mori, T., Nicolò, D., Nishiguchi, H., Ochi, A., Ootani, W., Oya, A., Palo, D., Panareo, M., Papa, A., Pettinacci, V., Popov, A., Renga, F., Ritt, S., Rossella, M., Scarpellini, A. Rozhdestvensky. S., Schwendimann, P., Signorelli, G., Takahashi, M., Uchiyama, Y., Venturini, A., Vitali, B., Voena, C., Yamamoto, K., Yokota, R., and Yonemoto, T.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The observation of a resonance structure in the opening angle of the electron-positron pairs in the $^{7}$Li(p,\ee) $^{8}$Be reaction was claimed and interpreted as the production and subsequent decay of a hypothetical particle (X17). Similar excesses, consistent with this particle, were later observed in processes involving $^{4}$He and $^{12}$C nuclei with the same experimental technique. The MEG II apparatus at PSI, designed to search for the $\mu^+ \rightarrow \mathrm{e}^+ \gamma$ decay, can be exploited to investigate the existence of this particle and study its nature. Protons from a Cockroft-Walton accelerator, with an energy up to 1.1 MeV, were delivered on a dedicated Li-based target. The $\gamma$ and the e$^{+}$e$^{-}$ pair emerging from the $^8\mathrm{Be}^*$ transitions were studied with calorimeters and a spectrometer, featuring a broader angular acceptance than previous experiments. We present in this paper the analysis of a four-week data-taking in 2023 with a beam energy of 1080 keV, resulting in the excitation of two different resonances with Q-value \SI{17.6}{\mega\electronvolt} and \SI{18.1}{\mega\electronvolt}. No significant signal was found, and limits at \SI{90}{\percent} C.L. on the branching ratios (relative to the $\gamma$ emission) of the two resonances to X17 were set, $R_{17.6} < 1.8 \times 10^{-6} $ and $R_{18.1} < 1.2 \times 10^{-5} $., Comment: 11 pages, 9 figures, submitted to EPJC

Published
2024

3. Search for Extended GeV Sources in the Inner Galactic Plane

Author

Abdollahi, S., Acero, F., Acharyya, A., Adelfio, A., Ajello, M., Baldini, L., Ballet, J., Bartolini, C., Gonzalez, J. Becerra, Bellazzini, R., Bissaldi, E., Bonino, R., Bruel, P., Cameron, R. A., Caraveo, P. A., Castro, D., Cavazzuti, E., Cheung, C. C., Cibrario, N., Ciprini, S., Cozzolongo, G., Orestano, P. Cristarella, Cuoco, A., Cutini, S., D'Ammando, F., Di Lalla, N., Dinesh, A., Di Venere, L., Domínguez, A., Fiori, A., Funk, S., Fusco, P., Gargano, F., Gasbarra, C., Gasparrini, D., Germani, S., Giacchino, F., Giglietto, N., Giliberti, M., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guillemot, L., Guiriec, S., Gupta, R., Hashizume, M., Hays, E., Hewitt, J. W., Horan, D., Hou, X., Kayanoki, T., Kuss, M., Laviron, A., Lemoine-Goumard, M., Liguori, A., Li, J., Liodakis, I., Loizzo, P., Longo, F., Loparco, F., Lorusso, L., Lovellette, M. N., Lubrano, P., Maldera, S., Malyshev, D., Martí-Devesa, G., Martin, P., Mazziotta, M. N., Mereu, I., Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Monti-Guarnieri, P., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Omodei, N., Orienti, M., Orlando, E., Paneque, D., Panzarini, G., Persic, M., Pesce-Rollins, M., Pillera, R., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Bernal, M. Rocamora, Sánchez-Conde, M., Parkinson, P. M. Saz, Serini, D., Sgrò, C., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Tajima, H., Thayer, J. B., Torres, D. F., Valverde, J., Wadiasingh, Z., Wood, K., and Zaharijas, G.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The recent detection of extended $\gamma$-ray emission around middle-aged pulsars is interpreted as inverse-Compton scattering of ambient photons by electron-positron pairs escaping the pulsar wind nebula, which are confined near the system by unclear mechanisms. This emerging population of $\gamma$-ray sources was first discovered at TeV energies and remains underexplored in the GeV range. To address this, we conducted a systematic search for extended sources along the Galactic plane using 14 years of Fermi-LAT data above 10 GeV, aiming to identify a number of pulsar halo candidates and extend our view to lower energies. The search covered the inner Galactic plane ($\lvert l\rvert\leq$ 100$^{\circ}$, $\lvert b\rvert\leq$ 1$^{\circ}$) and the positions of known TeV sources and bright pulsars, yielding broader astrophysical interest. We found 40 such sources, forming the Second Fermi Galactic Extended Sources Catalog (2FGES), most with 68% containment radii smaller than 1.0$^{\circ}$ and relatively hard spectra with photon indices below 2.5. We assessed detection robustness using field-specific alternative interstellar emission models and by inspecting significance maps. Noting 13 sources previously known as extended in the 4FGL-DR3 catalog and five dubious sources from complex regions, we report 22 newly detected extended sources above 10 GeV. Of these, 13 coincide with H.E.S.S., HAWC, or LHAASO sources; six coincide with bright pulsars (including four also coincident with TeV sources); six are associated with 4FGL point sources only; and one has no association in the scanned catalogs. Notably, six to eight sources may be related to pulsars as classical pulsar wind nebulae or pulsar halos., Comment: 43 pages, 17 figures, 11 tables

Published
2024

4. Multiwavelength coverage of the 2024 periastron passage of PSR B1259-63 / LS 2883

Author

Chernyakova, M., Malyshev, D., van Soelen, B., Galagher, A. Finn, Matchett, N., Russell, T. D., Eijnden, J. van den, Lower, M. E., Johnston, S., Tsygankov, S., Salganik, A., and Shebalkova, Iu.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

PSR B1259-63 is a gamma-ray binary system with a 48 ms radio pulsar orbiting around an O9.5Ve star, LS 2883, in a highly eccentric ~3.4 yr long orbit. Close to the periastron the system is detected from radio up to the TeV energies due to the interaction of LS 2883 and pulsar's outflows. The observations of last 4 periastra passages taken in 2010-2021 demonstrate periastron to periastron variability at all wavelength, probably linked to the state of the decretion disk. In this paper we present the results of our optical, radio and X-ray observational campaigns on PSR B1259-63 performed in 2024 accompanied with the analysis of the publicly available GeV FERMI/LAT data. We show that this periastron passage was characterised by the early flaring of X-rays before the periastron passage and GeV emission after the periastron passage, which can be explained by a larger size of the decretion disk as supported by the optical observations. The structure of the GeV flare is also in agreement with the disruption of the large dense disk. The possible X-ray/radio correlation was observed only during the post-periastron rise of X-ray and radio emission., Comment: submitted to MNRAS

Published
2024

5. QED calculations of intra-$L$-shell singly excited states in Be-like ions

Author

Malyshev, A. V., Kozhedub, Y. S., Shabaev, V. M., and Tupitsyn, I. I.

Subjects
Physics - Atomic Physics
Abstract

The \textit{ab initio} approach is used to evaluate the excitation energies of the $2s2p \, ^{2S+1}P_J$ states from the ground state as well as the $2s2p \, ^3P_1 \rightarrow 2s2p \, ^3P_0$ and $2s2p \, ^3P_2 \rightarrow 2s2p \, ^3P_1$ transition energies for selected Be-like highly-charged ions over a wide range: from ${\rm Ar}^{14+}$ to ${\rm U}^{88+}$. The issue of a strong level mixing due to the proximity of states with the same symmetry is addressed by applying the QED perturbation theory for quasidegenerate levels. The employed approach combines a rigorous perturbative QED treatment up to the second order with electron-electron correlation contributions of the third and higher orders calculated in the Breit approximation. The higher-order QED effects are estimated using the model-QED-operator approach. The nuclear-recoil and nuclear-polarization effects are taken into account as well. The performed calculations are accompanied with a thorough analysis of uncertainties due to uncalculated effects. The most accurate theoretical predictions for the excitation and transition energies in Be-like ions are obtained, which, in general, are in perfect agreement with the available experimental data., Comment: 15 pages, 1 figure, 5 tables

Published
2024

6. Effect of Biaxial Strain on Cation Octahedral Rotations and the Electronic Band Structure of the Antiperovskite Mn$_{3}$GaN

Author

Malyshev, Roman, Svenum, Ingeborg-Helene, Selbach, Sverre M., and Tybell, Thomas

Subjects
Condensed Matter - Materials Science
Abstract

Density functional theory is used to study the effect of compressive and tensile biaxial strain on Mn$_{3}$GaN. Mn$_{3}$GaN is a non-collinear antiferromagnetic antiperovskite with a similar structure to that of an ideal cubic oxide perovskite, but with cations at the octahedral sites while the anion, nitrogen, is found at the B site. The present study explores the response of Mn$_{3}$GaN to (001) strain, considering biaxial strain levels ranging from -5% to 5%. It is found that the electron structure is insensitive to tensile strain. The study supports previous results in that a spin-canted antiferromagnetic order emerges due to tensile strain, inducing net magnetization. Compressive strain collapses the non-collinear antiferromagnetic spin structure and induces a ferrimagnetic order at -2% strain. Notably, in contrast with oxide perovskites, Mn$_{3}$GaN does not respond to strain by octahedral tilt, but rather by intraband redistributions of charge between Mn $d$ states. Despite the similar structure to oxide perovskites, the bonds between the B site anion and octahedral site cations in Mn$_{3}$GaN bonds are less rigid, such that strain is instead accommodated by a change in bond length rather than a change in bond angles., Comment: 9 pages, 9 figures

Published
2024

7. GRB 221009A: the B.O.A.T Burst that Shines in Gamma Rays

Author

Axelsson, M., Ajello, M., Arimoto, M., Baldini, L., Ballet, J., Baring, M. G., Bartolini, C., Bastieri, D., Gonzalez, J. Becerra, Bellazzini, R., Berenji, B., Bissaldi, E., Blandford, R. D., Bonino, R., Bruel, P., Buson, S., Cameron, R. A., Caputo, R., Caraveo, P. A., Cavazzuti, E., Cheung, C. C., Chiaro, G., Cibrario, N., Ciprini, S., Cozzolongo, G., Orestano, P. Cristarella, Crnogorcevic, M., Cuoco, A., Cutini, S., D'Ammando, F., De Gaetano, S., Di Lalla, N., Dinesh, A., Di Tria, R., Di Venere, L., Domínguez, A., Fegan, S. J., Ferrara, E. C., Fiori, A., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Galanti, G., Gargano, F., Gasbarra, C., Germani, S., Giacchino, F., Giglietto, N., Giliberti, M., Gill, R., Giordano, F., Giroletti, M., Granot, J., Green, D., Grenier, I. A., Guiriec, S., Gustafsson, M., Hashizume, M., Hays, E., Hewitt, J. W., Horan, D., Kayanoki, T., Kuss, M., Laviron, A., Li, J., Liodakis, I., Longo, F., Loparco, F., Lorusso, L., Lott, B., Lovellette, M. N., Lubrano, P., Maldera, S., Malyshev, D., Manfreda, A., Martí-Devesa, G., Martinelli, R., Castellanos, I. Martinez, Mazziotta, M. N., McEnery, J. E., Mereu, I., Meyer, M., Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Monti-Guarnieri, P., Monzani, M. E., Morishita, T., Morselli, A., Moskalenko, I. V., Negro, M., Niwa, R., Omodei, N., Orienti, M., Orlando, E., Paneque, D., Panzarini, G., Persic, M., Pesce-Rollins, M., Petrosian, V., Pillera, R., Piron, F., Porter, T. A., Principe, G., Racusin, J. L., Rainò, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ryde, F., Sánchez-Conde, M., Parkinson, P. M. Saz, Serini, D., Sgrò, C., Sharma, V., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Tak, D., Thayer, J. B., Torres, D. F., Valverde, J., Zaharijas, G., Lesage, S., Briggs, M. S., Burns, E., Bala, S., Bhat, P. N., Cleveland, W. H., Dalessi, S., de Barra, C., Gibby, M., Giles, M. M., Hamburg, R., Hristov, B. A., Hui, C. M., Kocevski, D., Mailyan, B., Malacaria, C., McBreen, S., Poolakkil, S., Roberts, O. J., Scotton, L., Veres, P., von Kienlin, A., Wilson-Hodge, C. A., and Wood, J.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present a complete analysis of Fermi Large Area Telescope (LAT) data of GRB 221009A, the brightest Gamma-Ray Burst (GRB) ever detected. The burst emission above 30 MeV detected by the LAT preceded by 1 s the low-energy (< 10 MeV) pulse that triggered the Fermi Gamma-Ray Burst Monitor (GBM), as has been observed in other GRBs. The prompt phase of GRB 221009A lasted a few hundred seconds. It was so bright that we identify a Bad Time Interval (BTI) of 64 seconds caused by the extremely high flux of hard X-rays and soft gamma rays, during which the event reconstruction efficiency was poor and the dead time fraction quite high. The late-time emission decayed as a power law, but the extrapolation of the late-time emission during the first 450 seconds suggests that the afterglow started during the prompt emission. We also found that high-energy events observed by the LAT are incompatible with synchrotron origin, and, during the prompt emission, are more likely related to an extra component identified as synchrotron self-Compton (SSC). A remarkable 400 GeV photon, detected by the LAT 33 ks after the GBM trigger and directionally consistent with the location of GRB 221009A, is hard to explain as a product of SSC or TeV electromagnetic cascades, and the process responsible for its origin is uncertain. Because of its proximity and energetic nature, GRB 221009A is an extremely rare event., Comment: 60 pages, 38 figures, 9 tables

Published
2024

8. Efficient Online Sensitivity Analysis For The Injective Bottleneck Path Problem

Author

Kaymakov, Kirill V. and Malyshev, Dmitry S.

Subjects
Computer Science - Data Structures and Algorithms, Computer Science - Discrete Mathematics
Abstract

The tolerance of an element of a combinatorial optimization problem with respect to a given optimal solution is the maximum change, i.e., decrease or increase, of its cost, such that this solution remains optimal. The bottleneck path problem, for given an edge-capacitated graph, a source, and a target, is to find the $\max$-$\min$ value of edge capacities on paths between the source and the target. For any given sample of this problem with $n$ vertices and $m$ edges, there is known the Ramaswamy-Orlin-Chakravarty's algorithm to compute an optimal path and all tolerances with respect to it in $O(m+n\log n)$ time. In this paper, for any in advance given $(n,m)$-network with distinct edge capacities and $k$ source-target pairs, we propose an $O\Big(m \alpha(m,n)+\min\big((n+k)\log n,km\big)\Big)$-time preprocessing, where $\alpha(\cdot,\cdot)$ is the inverse Ackermann function, to find in $O(k)$ time all $2k$ tolerances of an arbitrary edge with respect to some $\max\min$ paths between the paired sources and targets. To find both tolerances of all edges with respect to those optimal paths, it asymptotically improves, for some $n,m,k$, the Ramaswamy-Orlin-Chakravarty's complexity $O\big(k(m+n\log n)\big)$ up to $O(m\alpha(n,m)+km)$., Comment: 13 pages, 0 figures

Published
2024

9. Neural Quantum States and Peaked Molecular Wave Functions: Curse or Blessing?

Author

Malyshev, Aleksei, Schmitt, Markus, and Lvovsky, A. I.

Subjects
Quantum Physics, Physics - Chemical Physics, Physics - Computational Physics
Abstract

The field of neural quantum states has recently experienced a tremendous progress, making them a competitive tool of computational quantum many-body physics. However, their largest achievements to date mostly concern interacting spin systems, while their utility for quantum chemistry remains yet to be demonstrated. Two main complications are the peaked structure of the molecular wave functions, which impedes sampling, and large number of terms in second quantised Hamiltonians, which hinders scaling to larger molecule sizes. In this paper we address these issues jointly and argue that the peaked structure might actually be key to drastically more efficient calculations. Specifically, we introduce a novel algorithm for autoregressive sampling without replacement and a procedure to calculate a computationally cheaper surrogate for the local energy. We complement them with a custom modification of the stochastic reconfiguration optimisation technique and a highly optimised GPU implementation. As a result, our calculations require substantially less resources and exhibit more than order of magnitude speedup compared to the previous works. On a single GPU we study molecules comprising up to 118 qubits and outperform the ``golden standard'' CCSD(T) benchmark in Hilbert spaces of $\sim 10^{15}$ Slater determinants, which is orders of magnitude larger than what was previously achieved. We believe that our work underscores the prospect of NQS for challenging quantum chemistry calculations and serves as a favourable ground for the future method development., Comment: Main text: 15 pages, 5 figures; Supplementary Material: 20 pages, 23 figures

Published
2024

10. Guardians of Image Quality: Benchmarking Defenses Against Adversarial Attacks on Image Quality Metrics

Author

Gushchin, Alexander, Abud, Khaled, Bychkov, Georgii, Shumitskaya, Ekaterina, Chistyakova, Anna, Lavrushkin, Sergey, Rasheed, Bader, Malyshev, Kirill, Vatolin, Dmitriy, and Antsiferova, Anastasia

Subjects
Computer Science - Computer Vision and Pattern Recognition, Electrical Engineering and Systems Science - Image and Video Processing
Abstract

In the field of Image Quality Assessment (IQA), the adversarial robustness of the metrics poses a critical concern. This paper presents a comprehensive benchmarking study of various defense mechanisms in response to the rise in adversarial attacks on IQA. We systematically evaluate 25 defense strategies, including adversarial purification, adversarial training, and certified robustness methods. We applied 14 adversarial attack algorithms of various types in both non-adaptive and adaptive settings and tested these defenses against them. We analyze the differences between defenses and their applicability to IQA tasks, considering that they should preserve IQA scores and image quality. The proposed benchmark aims to guide future developments and accepts submissions of new methods, with the latest results available online: https://videoprocessing.ai/benchmarks/iqa-defenses.html.

Published
2024

11. Effect of group-velocity dispersion on the generation of multimode pulsed squeezed light in a synchronously pumped optical parametric oscillator

Author

Averchenko, Valentin, Malyshev, Danil, and Tikhonov, Kirill

Subjects
Quantum Physics
Abstract

Parametric down-conversion in a nonlinear crystal is a widely employed technique for generating quadrature squeezed light with multiple modes, which finds applications in quantum metrology, quantum information and communication. Here we study the generation of temporally multimode pulsed squeezed light in a synchronously pumped optical parametric oscillator (SPOPO) operating below the oscillation threshold, while considering the presence of non-compensated intracavity group-velocity dispersion. Based on the developed timedomain model of the system, we show that the dispersion results in mode-dependent detuning of the broadband supermodes of the pulsed parametric process from the cavity resonance, as well as linear coupling between these supermodes. With the perturbation theory up to the second order in the coupling coefficients between modes, we obtained a solution for the supermode amplitudes given an arbitrary number of modes and pump level. The dispersion affects the quantum state of the supermodes by influencing their squeezing level and the rotation of the squeezing ellipse. It also affects the entanglement among the supermodes, leading to reduced suppression of shot noise level as measured in the balanced homodyne detection scheme. Furthermore, our study highlights the potential of SPOPO with group-velocity dispersion as a testbench for experimental investigations of multimode effects in linearly evanescent coupled parametric oscillators., Comment: 13 pages, 8 figures

Published
2024

12. H.E.S.S. observations of the 2021 periastron passage of PSR B1259-63/LS 2883

Author

Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaoui, M., Brose, R., Brown, A., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Mbarubucyeye, J. Damascene, Devin, J., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Ernenwein, J. -P., Fontaine, G., Funk, S., Gabici, S., Gallant, Y. A., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Haerer, L., Heß, B., Hofmann, W., Holch, T. L., Holler, M., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khangulyan, D., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Mackey, J., Malyshev, D., Martí-Devesa, G., Marx, R., Mehta, A., Meintjes, P. J., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., Ohm, S., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Pensec, U., Peron, G., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reimer, A., Reimer, O., Reis, I., Ren, H., Rieger, F., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Sushch, I., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Thorpe-Morgan, C., Tluczykont, M., Unbehaun, T., van Eldik, C., van Soelen, B., Vecchi, M., Venter, C., Vink, J., Wach, T., Wagner, S. J., Werner, F., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

PSR B1259-63 is a gamma-ray binary system that hosts a pulsar in an eccentric orbit, with a 3.4 year period, around an O9.5Ve star. At orbital phases close to periastron passages, the system radiates bright and variable non-thermal emission. We report on an extensive VHE observation campaign conducted with the High Energy Stereoscopic System, comprised of ~100 hours of data taken from $t_p-24$ days to $t_p+127$ days around the system's 2021 periastron passage. We also present the timing and spectral analyses of the source. The VHE light curve in 2021 is consistent with the stacked light curve of all previous observations. Within the light curve, we report a VHE maximum at times coincident with the third X-ray peak first detected in the 2021 X-ray light curve. In the light curve -- although sparsely sampled in this time period -- we see no VHE enhancement during the second disc crossing. In addition, we see no correspondence to the 2021 GeV flare in the VHE light curve. The VHE spectrum obtained from the analysis of the 2021 dataset is best described by a power law of spectral index $\Gamma = 2.65 \pm 0.04_{\text{stat}}$ $\pm 0.04_{\text{sys}}$, a value consistent with the previous H.E.S.S. observations of the source. We report spectral variability with a difference of $\Delta \Gamma = 0.56 ~\pm~ 0.18_{\text{stat}}$ $~\pm~0.10_{\text{sys}}$ at 95% c.l., between sub-periods of the 2021 dataset. We also find a linear correlation between contemporaneous flux values of X-ray and TeV datasets, detected mainly after $t_p+25$ days, suggesting a change in the available energy for non-thermal radiation processes. We detect no significant correlation between GeV and TeV flux points, within the uncertainties of the measurements, from $\sim t_p-23$ days to $\sim t_p+126$ days. This suggests that the GeV and TeV emission originate from different electron populations., Comment: accepted to A&A

Published
2024

13. Galactic center GeV excess and classification of Fermi-LAT sources with machine learning

Author

Malyshev, Dmitry V.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Excess of gamma rays with a spherical morphology around the Galactic center (GC) observed in the Fermi large area telescope (LAT) data is one of the most intriguing features in the gamma-ray sky. The excess has been interpreted by annihilating dark matter as well as emission from a population of unresolved millisecond pulsars (MSPs). We use a multi-class classification of Fermi-LAT sources with machine learning to study the distribution of MSP-like sources among unassociated Fermi-LAT sources near the GC. We find that the source count distribution of MSP-like sources is comparable with the MSP explanation of the GC excess., Comment: contribution to the 2024 Very High Energy Phenomena in the Universe session of the 58th Rencontres de Moriond, 4 pages, 2 figures

Published
2024

14. Search of extended emission from HESS J1702-420 with eROSITA

Author

Malyshev, Denys, Chernyakova, Maria, Aharonian, Felix, and Santangelo, Andrea

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

HESS J1702-420 is a peculiar TeV complex with a morphology changing from a diffuse (HESS J1702-420B source) at $\lesssim 2$ TeV to point-like (HESS J1702-420A) at $\gtrsim 10$ TeV energies. The morphology and the spectral properties of HESS J1702-420 could be understood in terms of a (diffusive) hadronic or leptonic models in which the observed TeV emission arises correpondingly from proton-proton or IC-radiation of relativistic particles present in the region. In this work we perform searches of the X-ray counterpart of HESS J1702-420B source originated from the synchrotron emission of the primary or secondary relativistic electrons produced within leptonic or hadronic models. Such an emission can be extended and remain beyond the detection capabilities of a narrow-FoV instruments such as XMM-Newton. We utilise the publicly available first 6-months eROSITA dataset (DR1) fully covering selected for the analysis region of $> 5^\circ$-radius around HESS J1702-420. We discuss biases connected to variable plasma temperature/neutral hydrogen column density in the region and present results based on background modelling approach. The performed analysis does not allow us to detect the extended X-ray counterpart of HESS J1702-420 of $0.07^\circ - 3^\circ$-radii sizes. The derived upper limits are significantly higher than the expected hadronic model flux of the X-ray counterpart. For the leptonic model the derived limits indicate the magnetic field in the region $B\lesssim 2\mu$G. We argue, that the further advances in the diffuse X-ray counterpart searches could be achieved either with next generation missions or Msec-long observational campaigns with currently operating instruments., Comment: accepted to A&A

Published
2024
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15. Forward $J/\psi + J/\psi$ and $J/\psi + \psi^\prime$ production with High Energy Factorization

Author

Baranov, S. P., Lipatov, A. V., Malyshev, M. A., Prokhorov, A. A., and Zhang, P. M.

Subjects
High Energy Physics - Phenomenology
Abstract

We calculate the cross sections of associated $J/\psi + \psi^\prime$ and $J/\psi + J/\psi$ production in $pp$ collisions at $\sqrt s = 13$ TeV in the forward kinematic region. The High Energy Factorization ($k_T$-factorization) framework supplemented with the Catani-Ciafaloni-Fiorani-Marchesini evolution of gluon densities in a proton is applied. We demonstrate that latest data on $J/\psi + J/\psi$ production and first experimental data on $J/\psi + \psi^\prime$ events taken very recently by the LHCb Collaboration can be described well by the color singlet terms and contributions from the double parton scattering (DPS) with the standard choice for $\sigma_{\rm eff}$ parameter. The relative production rate $\sigma(J/\psi + \psi^\prime)/\sigma(J/\psi + J/\psi)$ is found to be sensitive to the DPS terms as well as to feeddown contributions.

Published
2024

16. Delta-modular ILP Problems of Bounded Co-dimension, Discrepancy, and Convolution

Author

Gribanov, D., Malyshev, D., and Pardalos, P. M.

Subjects
Computer Science - Computational Complexity, Computer Science - Data Structures and Algorithms, Mathematics - Commutative Algebra, Mathematics - Optimization and Control
Abstract

For $k, n \geq 0$, and $c \in Z^n$, we consider ILP problems \begin{gather*} \max\bigl\{ c^\top x \colon A x = b,\, x \in Z^n_{\geq 0} \bigr\}\text{ with $A \in Z^{k \times n}$, $rank(A) = k$, $b \in Z^{k}$ and} \max\bigl\{ c^\top x \colon A x \leq b,\, x \in Z^n \bigr\} \text{ with $A \in Z^{(n+k) \times n}$, $rank(A) = n$, $b \in Z^{n+k}$.} \end{gather*} The first problem is called an \emph{ILP problem in the standard form of the codimension $k$}, and the second problem is called an \emph{ILP problem in the canonical form with $n+k$ constraints.} We show that, for any sufficiently large $\Delta$, both problems can be solved with $$ 2^{O(k)} \cdot (f_{k,d} \cdot \Delta)^2 / 2^{\Omega\bigl(\sqrt{\log(f_{k,d} \cdot \Delta)}\bigr)} $$ operations, where $ f_{k,d} = \min \Bigl\{ k^{k/2}, \bigl(\log k \cdot \log (d + k)\bigr)^{k/2} \Bigr\} $, $d$ is the dimension of a corresponding polyhedron and $\Delta$ is the maximum absolute value of $rank(A) \times rank(A)$ sub-determinants of $A$. As our second main result, we show that the feasibility variants of both problems can be solved with $$ 2^{O(k)} \cdot f_{k,d} \cdot \Delta \cdot \log^3(f_{k,d} \cdot \Delta) $$ operations. The constant $f_{k,d}$ can be replaced by other constant $g_{k,\Delta} = \bigl(\log k \cdot \log (k \Delta)\bigr)^{k/2}$ that depends only on $k$ and $\Delta$. Additionally, we consider different partial cases with $k=0$ and $k=1$, which have interesting applications. As a result of independent interest, we propose an $n^2/2^{\Omega\bigl(\sqrt{\log n}\bigr)}$-time algorithm for the tropical convolution problem on sequences, indexed by elements of a finite Abelian group of the order $n$. Additionally, we give a complete, self-contained error analysis of the generalized Discrete Fourier Transform for Abelian groups with respect to the Word-RAM computational model.

Published
2024

17. Two models for the orbital modulation of $\gamma$-rays in Cyg X-3

Author

Dmytriiev, Anton, Zdziarski, Andrzej A., Malyshev, Denys, Bosch-Ramon, Valenti, and Chernyakova, Maria

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We model the currently available $\gamma$-ray data from the Fermi Large Area Telescope on Cyg X-3. Thanks to its very strong $\gamma$-ray activity during 2018--2021, the data quality has significantly improved. We study the strong orbital modulation of the $\gamma$-rays observed during at high $\gamma$-ray fluxes. The modulation, as found earlier, is well modeled by anisotropic Compton scattering of the donor blackbody emission by relativistic electrons in a jet strongly misaligned with respect to the orbital axis. We confirm that this model fits well both the average $\gamma$-ray modulation light curve and the spectrum. However, we find that if the jet is aligned with the spin axis of a rotating black hole, it would undergo geodetic precession with the period of $\sim$50 years. However, its presence is ruled out by both the $\gamma$-ray and radio data. Therefore, we consider an alternative model in which the average jet direction jet is aligned, but it is bent to outside the orbit owing to the thrust of the donor stellar wind, and thus precesses at the orbital period. The $\gamma$-ray modulation appears then owing to the variable Doppler boosting of synchrotron self-Compton jet emission. The model also fits well the data. However, the fitted bending angle is much larger than the theoretical one based on the binary and wind parameters as currently known. Thus, both models disagree with important aspects of our current theoretical understanding of the system. We discuss possible ways to find the correct model., Comment: ApJ, in press

Published
2024

18. End-to-End Autoencoder for Drill String Acoustic Communications

Author

Lezhenin, Iurii, Sidnev, Aleksandr, Tsygan, Vladimir, and Malyshev, Igor

Subjects
Computer Science - Machine Learning, Electrical Engineering and Systems Science - Signal Processing
Abstract

Drill string communications are important for drilling efficiency and safety. The design of a low latency drill string communication system with high throughput and reliability remains an open challenge. In this paper a deep learning autoencoder (AE) based end-to-end communication system, where transmitter and receiver implemented as feed forward neural networks, is proposed for acousticdrill string communications. Simulation shows that the AE system is able to outperform a baseline non-contiguous OFDM system in terms of BER and PAPR, operating with lower latency.

Published
2024

19. Isotope-shift factors with quantum electrodynamics effects for many-electron systems: A study of the nuclear charge radius of $^{26m}$Al

Author

Skripnikov, Leonid V., Prosnyak, Sergey D., Malyshev, Aleksei V., Athanasakis-Kaklamanakis, Michail, Brinson, Alex Jose, Minamisono, Kei, Cruz, Fabian C. Pastrana, Reilly, Jordan Ray, Rickey, Brooke J., and Ruiz, Ronald. F. Garcia

Subjects
Physics - Atomic Physics, Nuclear Theory, Physics - Chemical Physics
Abstract

A method for calculating the field shift contribution to isotope shifts in many-electron atoms, incorporating quantum electrodynamics (QED) effects, is introduced. We also implement the model QED approach to incorporate QED contribution to the nuclear recoil effect at the high-order correlation effects treatment level. The proposed computational scheme is used to revise the value of the root-mean-square (rms) nuclear charge radius of the isomer of aluminium-26, $^{26m}$Al. This radius is important for the global analysis of the $V_{ud}$ element of the Cabibbo-Kobayashi-Maskawa matrix. The difference in mean-square nuclear charge radii of $^{27}$Al and $^{26m}$Al, obtained by combining the calculated atomic factors with recently measured isotope shift (IS) of the $3s^23p~^2P_{3/2} \to 3s^24s~^2S_{1/2}$ transition in Al, is $0.443(44)(19)~{\rm fm}^2$, where the first and second uncertainties are experimental and theoretical ones, respectively. The latter is reduced by a factor of 4 with respect to the previous study. Using this value and the known value of the rms charge radius of $^{27}$Al, the resultant value $R_c(^{26m}$Al) = 3.132(10)~fm is obtained. With the improved accuracy of the calculated IS factors the error in $R_c(^{26m}$Al) is now dominated by the experimental uncertainty. Similar revision of rms charge radii is made for the $^{28}$Al, $^{29}$Al, $^{30}$Al, $^{31}$Al and $^{32}$Al isotopes using existing IS measurements. Additionally, atomic factors are computed for the $3s^23p~^2P_{3/2} \to 3s^24s~^2S_{1/2}$, $3s^23p~^2P_{1/2} \to 3s^25s~^2S_{1/2}$ and $3s^23p~^2P_{3/2} \to 3s^25s~^2S_{1/2}$ transitions in Al, which can be used in future experimental studies.

Published
2024
Full Text
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20. Refined TMD gluon density in a proton from the HERA and LHC data

Author

Lipatov, A. V., Lykasov, G. I., and Malyshev, M. A.

Subjects
High Energy Physics - Phenomenology
Abstract

We update the phenomenological parameters of the Transverse Momentum Dependent (TMD, or unintegrated) gluon density in a proton proposed in our previous studies. This analysis is based on the analytical expression for starting gluon distribution which provides a self-consistent simultaneous description of HERA data on proton structure function $F_2(x,Q^2)$, reduced cross section for the electron-proton deep inelastic scattering at low $Q^2$ and soft hadron production in $pp$ collisions at the LHC conditions. We extend it to the whole kinematical region using the Catani-Ciafaloni-Fiorani-Marchesini (CCFM) evolution equation. Exploiting our previous results on a number of semihard QCD processes, we performed a combined fit to an extended set of LHC and HERA data, comprising a total of $509$ points from $16$ data sets. We illustrate our fit by applying the derived TMD gluon density in a proton to inclusive prompt photon photoproduction at HERA., Comment: 9 pages, 2 figures, 1 table

Published
2024

21. Technical Design Report of the Spin Physics Detector at NICA

Author

The SPD Collaboration, Abazov, V., Abramov, V., Afanasyev, L., Akhunzyanov, R., Akindinov, A., Alekseev, I., Aleshko, A., Alexakhin, V., Alexeev, G., Alimov, L., Allakhverdieva, A., Amoroso, A., Andreev, V., Andronov, E., Anikin, Yu., Anischenko, S., Anisenkov, A., Anosov, V., Antokhin, E., Antonov, A., Antsupov, S., Anufriev, A., Asadova, K., Ashraf, S., Astakhov, V., Aynikeev, A., Azarkin, M., Azorskiy, N., Bagulya, A., Baigarashev, D., Baldin, A., Baldina, E., Barbashina, N., Barnyakov, A., Barsov, S., Bartkevich, A., Baryshevsky, V., Basharina, K., Baskakov, A., Baskov, V., Batista, M., Baturitsky, M., Bautin, V., Bedareva, T., Belokurova, S., Belova, A., Belyaeva, E., Berdnikov, A., Berdnikov, Ya., Berezhnoy, A., Berngardt, A., Bespalov, Yu., Bleko, V., Bliznyuk, L., Bogoslovskii, D., Boiko, A., Boikov, A., Bolsunovskya, M., Boos, E., Borisov, V., Borsch, V., Budkouski, D., Bulanova, S., Bulekov, O., Bunichev, V., Burtebayev, N., Bychanok, D., Casanova, A., Cesar, G., Chemezov, D., Chepurnov, A., Chen, L., Chmill, V., Chukanov, A., Chuzo, A., Danilyuk, A., Datta, A., Dedovich, D., Demichev, M., Deng, G., Denisenko, I., Denisov, O., Derbysheva, T., Derkach, D., Didorenko, A., Dima, M. -O., Doinikov, A., Doronin, S., Dronik, V., Dubinin, F., Dunin, V., Durum, A., Egorov, A., El-Kholy, R., Enik, T., Ermak, D., Erofeev, D., Erokhin, A., Ezhov, D., Fedin, O., Fedotova, Ju., Feofilov, G., Filatov, Yu., Filimonov, S., Frolov, V., Galaktionov, K., Galoyan, A., Garkun, A., Gavrishchuk, O., Gerasimov, S., Gerassimov, S., Gilts, M., Gladilin, L., Golovanov, G., Golovnya, S., Golovtsov, V., Golubev, A., Golubykh, S., Goncharov, P., Gongadze, A., Greben, N., Gregoryev, A., Gribkov, D., Gridin, A., Gritsay, K., Gubachev, D., Guo, J., Gurchin, Yu., Gurinovich, A., Gurov, Yu., Guskov, A., Gutierrez, D., Guzman, F., Hakobyan, A., Han, D., Harkusha, S., Hu, Sh., Igolkin, S., Isupov, A., Ivanov, A., Ivanov, N., Ivantchenko, V., Jin, Sh., Kakurin, S., Kalinichenko, N., Kambar, Y., Kantsyrev, A., Kapitonov, I., Karjavine, V., Karpishkov, A., Katcin, A., Kekelidze, G., Kereibay, D., Khabarov, S., Kharyuzov, P., Khodzhibagiyan, H., Kidanov, E., Kidanova, E., Kim, V., Kiryanov, A., Kishchin, I., Kokoulina, E., Kolbasin, A., Komarov, V., Konak, A., Kopylov, Yu., Korjik, M., Korotkov, M., Korovkin, D., Korzenev, A., Kostenko, B., Kotova, A., Kotzinian, A., Kovalenko, V., Kovyazina, N., Kozhin, M., Kraeva, A., Kramarenko, V., Kremnev, A., Kruchonak, U., Kubankin, A., Kuchinskaia, O., Kulchitsky, Yu., Kuleshov, S., Kulikov, A., Kulikov, V., Kurbatov, V., Kurmanaliev, Zh., Kurochkin, Yu., Kutuzov, S., Kuznetsova, E., Kuyanov, I., Ladygin, E., Ladygin, V., Larionova, D., Lebedev, V., Levchuk, M., Li, P., Li, X., Li, Y., Livanov, A., Lednicki, R., Lobanov, A., Lobko, A., Loshmanova, K., Lukashevich, S., Luschevskaya, E., Lyashko, A. L'vov I., Lysan, V., Lyubovitskij, V., Madigozhin, D., Makarenko, V., Makarov, N., Makhmanazarov, R., Maleev, V., Maletic, D., Malinin, A., Maltsev, A., Maltsev, N., Malkhasyan, A., Malyshev, M., Mamoutova, O., Manakonov, A., Marova, A., Merkin, M., Meshkov, I., Metchinsky, V., Minko, O., Mitrankov, Yu., Mitrankova, M., Mkrtchyan, A., Mkrtchyan, H., Mohamed, R., Morozova, S., Morozikhin, A., Mosolova, E., Mossolov, V., Movchan, S., Mukhamejanov, Y., Mukhamejanova, A., Muzyaev, E., Myktybekov, D., Nagorniy, S., Nassurlla, M., Nechaeva, P., Negodaev, M., Nesterov, V., Nevmerzhitsky, M., Nigmatkulov, G., Nikiforov, D., Nikitin, V., Nikolaev, A., Oleynik, D., Onuchin, V., Orlov, I., Orlova, A., Ososkov, G., Panzieri, D., Parsamyan, B., Pavzderin, P., Pavlov, V., Pedraza, M., Perelygin, V., Peshkov, D., Petrosyan, A., Petrov, M., Petrov, V., Petrukhin, K., Piskun, A., Pivovarov, S., Polishchuk, I., Polozov, P., Polyanskii, V., Ponomarev, A., Popov, V., Popovich, S., Prokhorova, D., Prokofiev, N., Prokoshin, F., Puchkov, A., Pudin, I., Pyata, E., Ratnikov, F., Rasin, V., Red'kov, V., Reshetin, A., Reznikov, S., Rogacheva, N., Romakhov, S., Rouba, A., Rudnev, V., Rusinov, V., Rusov, D., Ryltsov, V., Saduyev, N., Safonov, A., Sakhiyev, S., Salamatin, K., Saleev, V., Samartsev, A., Samigullin, E., Samoylov, O., Saprunov, E., Savenkov, A., Seleznev, A., Semak, A., Senkov, D., Sergeev, A., Seryogin, L., Seryubin, S., Shabanov, A., Shahinyan, A., Shavrin, A., Shein, I., Sheremeteva, A., Shevchenko, V., Shilyaev, K., Shimansky, S., Shinbulatov, S., Shipilov, F., Shipilova, A., Shkarovskiy, S., Shoukovy, D., Shpakov, K., Shreyber, I., Shtejer, K., Shulyakovsky, R., Shunko, A., Sinelshchikova, S., Skachkova, A., Skalnenkov, A., Smirnov, A., Smirnov, S., Snesarev, A., Solin, A., Solin jr., A., Soldatov, E., Solovtsov, V., Song, J., Sosnov, D., Stavinskiy, A., Stekacheva, D., Streletskaya, E., Strikhanov, M., Suarez, O., Sukhikh, A., Sukhovarov, S., Sulin, V., Sultanov, R., Sun, P., Svirida, D., Syresin, E., Tadevosyan, V., Tarasov, O., Tarkovsky, E., Tchekhovsky, V., Tcherniaev, E., Terekhin, A., Terkulov, A., Tereshchenko, V., Teryaev, O., Teterin, P., Tishevsky, A., Tokmenin, V., Topilin, N., Tsiareshka, P., Tumasyan, A., Tyumenkov, G., Usenko, E., Uvarov, L., Uzhinsky, V., Uzikov, Yu., Valiev, F., Vasilieva, E., Vasyukov, A., Vechernin, V., Verkheev, A., Vertogradov, L., Vertogradova, Yu., Vidal, R., Voitishin, N., Volkov, I., Volkov, P., Vorobyov, A., Voskanyan, H., Wang, H., Wang, Y., Xu, T., Yanovich, A., Yeletskikh, I., Yerezhep, N., Yurchenko, S., Zakharov, A., Zamiatin, N., Zamora-Saá, J., Zarochentsev, A., Zelenov, A., Zemlyanichkina, E., Zhabitsky, M., Zhang, J., Zhang, Zh., Zhemchugov, A., Zherebchevsky, V., Zhevlakov, A., Zhigareva, N., Zhou, J., Zhuang, X., Zhukov, I., Zhuravlev, N., Zinin, A., Zmeev, S., Zolotykh, D., Zubarev, E., and Zvyagina, A.

Subjects
High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

The Spin Physics Detector collaboration proposes to install a universal detector in the second interaction point of the NICA collider under construction (JINR, Dubna) to study the spin structure of the proton and deuteron and other spin-related phenomena using a unique possibility to operate with polarized proton and deuteron beams at a collision energy up to 27 GeV and a luminosity up to $10^{32}$ cm$^{-2}$ s$^{-1}$. As the main goal, the experiment aims to provide access to the gluon TMD PDFs in the proton and deuteron, as well as the gluon transversity distribution and tensor PDFs in the deuteron, via the measurement of specific single and double spin asymmetries using different complementary probes such as charmonia, open charm, and prompt photon production processes. Other polarized and unpolarized physics is possible, especially at the first stage of NICA operation with reduced luminosity and collision energy of the proton and ion beams. This document is dedicated exclusively to technical issues of the SPD setup construction.

Published
2024

22. Convergence-acceleration approach to partial-wave expansion of two-electron self-energy contributions to the Lamb shift

Author

Malyshev, A. V., Prokhorchuk, E. A., and Shabaev, V. M.

Subjects
Physics - Atomic Physics
Abstract

Methods of bound-state QED that treat the self-energy contributions to the Lamb shift within the partial-wave expansion usually face the problem of slow convergence of the latter. Inspired by an approach formulated in [J. Sapirstein and K. T. Cheng, Phys. Rev. A 108, 042804 (2023)], we propose a modification of the standard procedure for calculating the contributions of two-electron self-energy diagrams. The performance of the method is studied by evaluating the corresponding corrections to the binding energies of He-like ions and by comparing the obtained results with the state-of-the-art values available in the literature: our calculations involving a much smaller number of partial waves show an improvement in accuracy., Comment: 17 pages, 9 figures, 6 tables

Published
2024

23. Unveiling extended gamma-ray emission around HESS J1813-178

Author

Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Baktash, A., Martins, V. Barbosa, Barnard, J., Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaoui, M., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chambery, P., Chand, T., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Dmytriiev, A., Doroshenko, V., Einecke, S., Ernenwein, J. -P., Feijen, K., Filipovic, M., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitt, G., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Grondin, M. -H., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Katarzyński, K., Khatoon, R., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Mackey, J., Malyshev, D., Marandon, V., Marinos, P., Martí-Devesa, G., Marx, R., Mehta, A., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., Noel, A. Priyana, O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reichherzer, P., Reimer, A., Reimer, O., Ren, H., Renaud, M., Reville, B., Rieger, F., Roellinghoff, G., Rudak, B., Sahakian, V., Salzmann, H., Sasaki, M., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Specovius, A., Spencer, S., Steenkamp, R., Steinmassl, S., Steppa, C., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Tluczykont, M., Tsuji, N., Unbehaun, T., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zouari, S., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

HESS J1813$-$178 is a very-high-energy $\gamma$-ray source spatially coincident with the young and energetic pulsar PSR J1813$-$1749 and thought to be associated with its pulsar wind nebula (PWN). Recently, evidence for extended high-energy emission in the vicinity of the pulsar has been revealed in the Fermi Large Area Telescope (LAT) data. This motivates revisiting the HESS J1813$-$178 region, taking advantage of improved analysis methods and an extended data set. Using data taken by the High Energy Stereoscopic System (H.E.S.S.) experiment and the Fermi-LAT, we aim to describe the $\gamma$-ray emission in the region with a consistent model, to provide insights into its origin. We performed a likelihood-based analysis on 32 hours of H.E.S.S. data and 12 years of Fermi-LAT data and fit a spectro-morphological model to the combined datasets. These results allowed us to develop a physical model for the origin of the observed $\gamma$-ray emission in the region. In addition to the compact very-high-energy $\gamma$-ray emission centered on the pulsar, we find a significant yet previously undetected component along the Galactic plane. With Fermi-LAT data, we confirm extended high-energy emission consistent with the position and elongation of the extended emission observed with H.E.S.S. These results establish a consistent description of the emission in the region from GeV energies to several tens of TeV. This study suggests that HESS J1813$-$178 is associated with a $\gamma$-ray PWN powered by PSR J1813$-$1749. A possible origin of the extended emission component is inverse Compton emission from electrons and positrons that have escaped the confines of the pulsar and form a halo around the PWN., Comment: 13+5 pages, 13+11 figures. Accepted for publication in A&A. Corresponding authors: T.Wach, A.Mitchell, V.Joshi, P.Chamb\'ery

Published
2024
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24. Spectrum and extension of the inverse-Compton emission of the Crab Nebula from a combined Fermi-LAT and H.E.S.S. analysis

Author

Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Baktash, A., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bradascio, F., Breuhaus, M., Brose, R., Brown, A., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chambery, P., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Cristofari, P., Devin, J., Djannati-Ataï, A., Djuvsland, J., Dmytriiev, A., Einecke, S., Ernenwein, J. -P., Fegan, S., Feijen, K., Filipović, M., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Giavitto, G., Glawion, D., Glicenstein, J. F., Glombitza, J., Goswami, P., Grolleron, G., Grondin, M. -H., Haerer, L., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Jamrozy, M., Jankowsky, F., Joshi, V., Kasai, E., Katarzyński, K., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Luashvili, A., Mackey, J., Malyshev, D., Marandon, V., Marinos, P., Martí-Devesa, G., Marx, R., Mehta, A., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reichherzer, P., Reimer, A., Reimer, O., Ren, H., Renaud, M., Reville, B., Rieger, F., Roellinghoff, G., Rudak, B., Sahakian, V., Salzmann, H., Sasaki, M., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Specovius, A., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Tluczykont, M., Tsuji, N., Unbehaun, T., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., Żywucka, N., and Harding, A.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The Crab Nebula is a unique laboratory for studying the acceleration of electrons and positrons through their non-thermal radiation. Observations of very-high-energy $\gamma$ rays from the Crab Nebula have provided important constraints for modelling its broadband emission. We present the first fully self-consistent analysis of the Crab Nebula's $\gamma$-ray emission between 1 GeV and $\sim$100 TeV, that is, over five orders of magnitude in energy. Using the open-source software package Gammapy, we combined 11.4 yr of data from the Fermi Large Area Telescope and 80 h of High Energy Stereoscopic System (H.E.S.S.) data at the event level and provide a measurement of the spatial extension of the nebula and its energy spectrum. We find evidence for a shrinking of the nebula with increasing $\gamma$-ray energy. Furthermore, we fitted several phenomenological models to the measured data, finding that none of them can fully describe the spatial extension and the spectral energy distribution at the same time. Especially the extension measured at TeV energies appears too large when compared to the X-ray emission. Our measurements probe the structure of the magnetic field between the pulsar wind termination shock and the dust torus, and we conclude that the magnetic field strength decreases with increasing distance from the pulsar. We complement our study with a careful assessment of systematic uncertainties., Comment: 18+6 pages, 15+2 figures. Accepted for publication in A&A. Corresponding authors: M. Meyer, L. Mohrmann, T. Unbehaun. v2: after A&A language editing

Published
2024
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25. Dark Matter Line Searches with the Cherenkov Telescope Array

Author

Abe, S., Abhir, J., Abhishek, A., Acero, F., Acharyya, A., Adam, R., Aguasca-Cabot, A., Agudo, I., Aguirre-Santaella, A., Alfaro, J., Alfaro, R., Alvarez-Crespo, N., Batista, R. Alves, Amans, J. -P., Amato, E., Ambrosi, G., Angel, L., Aramo, C., Arcaro, C., Arnesen, T. T. H., Arrabito, L., Asano, K., Ascasibar, Y., Aschersleben, J., Ashkar, H., Backes, M., Baktash, A., Balazs, C., Balbo, M., Larriva, A. Baquero, Martins, V. Barbosa, de Almeida, U. Barres, Barrio, J. A., Batković, I., Batzofin, R., Baxter, J., González, J. Becerra, Beck, G., Benbow, W., Berge, D., Bernardini, E., Bernete, J., Bernlöhr, K., Berti, A., Bertucci, B., Bhattacharjee, P., Bhattacharyya, S., Bigongiari, C., Biland, A., Bissaldi, E., Biteau, J., Blanch, O., Blazek, J., Bocchino, F., Boisson, C., Bolmont, J., Bonnoli, G., Bonollo, A., Bordas, P., Bosnjak, Z., Bottacini, E., Böttcher, M., Bringmann, T., Bronzini, E., Brose, R., Brown, A. M., Brunelli, G., Bulgarelli, A., Bulik, T., Burelli, I., Burmistrov, L., Burton, M., Buscemi, M., Bylund, T., Cailleux, J., Campoy-Ordaz, A., Cantlay, B. K., Capasso, G., Caproni, A., Capuzzo-Dolcetta, R., Caraveo, P., Caroff, S., Carosi, A., Carosi, R., Carquin, E., Carrasco, M. -S., Cassol, F., Castaldini, L., Castrejon, N., Castro-Tirado, A. J., Cerasole, D., Cerruti, M., Chadwick, P. M., Chaty, S., Chen, A. W., Chernyakova, M., Chiavassa, A., Chudoba, J., Chytka, L., Cicciari, G. M., Cifuentes, A., Araujo, C. H. Coimbra, Colapietro, M., Conforti, V., Conte, F., Contreras, J. L., Costa, A., Costantini, H., Cotter, G., Cristofari, P., Cuevas, O., Curtis-Ginsberg, Z., D'Amico, G., D'Ammando, F., Dai, S., Dalchenko, M., Dazzi, F., De Angelis, A., de Lavergne, M. de Bony, De Caprio, V., Pino, E. M. de Gouveia Dal, De Lotto, B., De Lucia, M., de Menezes, R., de Naurois, M., de Souza, V., del Peral, L., del Valle, M. V., Giler, A. G. Delgado, Mengual, J. Delgado, Delgado, C., Dell'aiera, M., della Volpe, D., Depaoli, D., Di Girolamo, T., Di Piano, A., Di Pierro, F., Di Tria, R., Di Venere, L., Díaz, C., Diebold, S., Dinesh, A., Djuvsland, J., Dominik, R. M., Prester, D. Dominis, Donini, A., Dorner, D., Dörner, J., Doro, M., Dournaux, J. -L., Duangchan, C., Dubos, C., Ducci, L., Dwarkadas, V. V., Ebr, J., Eckner, C., Egberts, K., Einecke, S., Elsässer, D., Emery, G., Errando, M., Escanuela, C., Escarate, P., Godoy, M. Escobar, Escudero, J., Esposito, P., Ettori, S., Falceta-Goncalves, D., Fedorova, E., Fegan, S., Feng, Q., Ferrand, G., Ferrarotto, F., Fiandrini, E., Fiasson, A., Filipovic, M., Fioretti, V., Fiori, M., Foffano, L., Guiteras, L. Font, Fontaine, G., Fröse, S., Fukazawa, Y., Fukui, Y., Furniss, A., Galanti, G., Galaz, G., Galelli, C., Gallozzi, S., Gammaldi, V., Garczarczyk, M., Gasbarra, C., Gasparrini, D., Ghalumyan, A., Gianotti, F., Giarrusso, M., Paiva, J. G. Giesbrecht Formiga, Giglietto, N., Giordano, F., Giuffrida, R., Glicenstein, J. -F., Glombitza, J., Goldoni, P., González, J. M., González, M. M., Coelho, J. Goulart, Gradetzke, T., Granot, J., Grasso, D., Grau, R., Gréaux, L., Green, D., Green, J. G., Grolleron, G., Guedes, L. M. V., Gueta, O., Hackfeld, J., Hadasch, D., Hamal, P., Hanlon, W., Hara, S., Harvey, V. M., Hassan, T., Hayashi, K., Heß, B., Heckmann, L., Heller, M., Cadena, S. Hernández, Hervet, O., Hinton, J., Hiroshima, N., Hnatyk, B., Hnatyk, R., Hofmann, W., Holder, J., Horan, D., Horvath, P., Hovatta, T., Hrabovsky, M., Hrupec, D., Iarlori, M., Inada, T., Incardona, F., Inoue, S., Inoue, Y., Iocco, F., Iori, M., Ishio, K., Jamrozy, M., Janecek, P., Jankowsky, F., Jean, P., Quiles, J. Jimenez, Jin, W., Juramy-Gilles, C., Jurysek, J., Kagaya, M., Kalekin, O., Karas, V., Katagiri, H., Kataoka, J., Kaufmann, S., Kazanas, D., Kerszberg, D., Kieda, D. B., Kleiner, T., Kluge, G., Kobayashi, Y., Kohri, K., Komin, N., Kornecki, P., Kosack, K., Kowal, G., Kubo, H., Kushida, J., La Barbera, A., La Palombara, N., Láinez, M., Lamastra, A., Lapington, J., Laporte, P., Lazarević, S., Lazendic-Galloway, J., Lemoine-Goumard, M., Lenain, J. -P., Leone, F., Leonora, E., Leto, G., Lindfors, E., Linhoff, M., Liodakis, I., Lipniacka, A., Lombardi, S., Longo, F., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Bahilo, J. Lozano, Luque-Escamilla, P. L., Macias, O., Majumdar, P., Mallamaci, M., Malyshev, D., Mandat, D., Manicò, G., Mariotti, M., Márquez, I., Marquez, P., Marsella, G., Martí, J., Martínez, G. A., Martínez, M., Martinez, O., Marty, C., Mas-Aguilar, A., Mastropietro, M., Mazin, D., Menchiari, S., Mestre, E., Meunier, J. -L., Meyer, D. M. -A., Meyer, M., Miceli, D., Miceli, M., Michailidis, M., Michałowski, J., Miener, T., Miranda, J. M., Mitchell, A., Mizote, M., Mizuno, T., Moderski, R., Molero, M., Molfese, C., Molina, E., Montaruli, T., Moralejo, A., Morcuende, D., Morselli, A., Moulin, E., Zamanillo, V. Moya, Munari, K., Murach, T., Muraczewski, A., Muraishi, H., Nakamori, T., Nayak, A., Nemmen, R., Neto, J. P., Nickel, L., Niemiec, J., Nieto, D., Rosillo, M. Nievas, Nikołajuk, M., Nikolić, L., Nishijima, K., Noda, K., Nosek, D., Novotny, V., Nozaki, S., Ohishi, M., Ohtani, Y., Okumura, A., Olive, J. -F., Ong, R. A., Orienti, M., Orito, R., Orlandini, M., Orlando, E., Orlando, S., Ostrowski, M., Otero-Santos, J., Oya, I., Pagano, I., Pagliaro, A., Palatiello, M., Panebianco, G., Paneque, D., Pantaleo, F. R., Paredes, J. M., Parmiggiani, N., Patricelli, B., Pe'er, A., Pech, M., Pecimotika, M., Pensec, U., Peresano, M., Pérez-Romero, J., Persic, M., Peters, K. P., Petruk, O., Piano, G., Pierre, E., Pietropaolo, E., Pihet, M., Pinchbeck, L., Pirola, G., Pittori, C., Plard, C., Podobnik, F., Pohl, M., Pollet, V., Ponti, G., Prandini, E., Principe, G., Priyadarshi, C., Produit, N., Prouza, M., Pueschel, E., Pühlhofer, G., Pumo, M. L., Queiroz, F., Quirrenbach, A., Rainò, S., Rando, R., Razzaque, S., Regeard, M., Reimer, A., Reimer, O., Reisenegger, A., Rhode, W., Ribeiro, D., Ribó, M., Ricci, C., Richtler, T., Rico, J., Rieger, F., Riitano, L., Rizi, V., Roache, E., Fernandez, G. Rodriguez, Frías, M. D. Rodríguez, Rodríguez-Vázquez, J. J., Romano, P., Romeo, G., Rosado, J., de Leon, A. Rosales, Rowell, G., Rudak, B., Ruiter, A. J., Rulten, C. B., Sadeh, I., Saha, L., Saito, T., Salzmann, H., Sánchez-Conde, M., Sandaker, H., Sangiorgi, P., Sano, H., Santander, M., Santos-Lima, R., Sapienza, V., Šarić, T., Sarkar, A., Sarkar, S., Saturni, F. G., Savarese, S., Scherer, A., Schiavone, F., Schipani, P., Schleicher, B., Schovanek, P., Schubert, J. L., Schwanke, U., Arroyo, M. Seglar, Seitenzahl, I. R., Sergijenko, O., Servillat, M., Siegert, T., Siejkowski, H., Siqueira, C., Sliusar, V., Slowikowska, A., Sol, H., Spencer, S. T., Spiga, D., Stamerra, A., Stanič, S., Starecki, T., Starling, R., Stawarz, Ł., Steppa, C., Hatlen, E. Sæther, Stolarczyk, T., Strišković, J., Suda, Y., Świerk, P., Tajima, H., Tak, D., Takahashi, M., Takeishi, R., Tavernier, T., Tejedor, L. A., Terauchi, K., Teshima, M., Testa, V., Tian, W. W., Tibaldo, L., Tibolla, O., Peixoto, C. J. Todero, Torradeflot, F., Torres, D. F., Tosti, G., Tothill, N., Toussenel, F., Tramacere, A., Travnicek, P., Tripodo, G., Trois, A., Truzzi, S., Tutone, A., Vaclavek, L., Vacula, M., Vallania, P., Vallés, R., van Eldik, C., van Scherpenberg, J., Vandenbroucke, J., Vassiliev, V., Acosta, M. Vázquez, Vecchi, M., Ventura, S., Vercellone, S., Verna, G., Viana, A., Viaux, N., Vigliano, A., Vignatti, J., Vigorito, C. F., Villanueva, J., Visentin, E., Vitale, V., Vodeb, V., Voisin, V., Voitsekhovskyi, V., Vorobiov, S., Voutsinas, G., Vovk, I., Vuillaume, T., Wagner, S. J., Walter, R., White, M., White, R., Wierzcholska, A., Will, M., Williams, D. A., Wohlleben, F., Wolter, A., Yamamoto, T., Yang, L., Yoshida, T., Yoshikoshi, T., Zaharijas, G., Zampieri, L., Sanchez, R. Zanmar, Zavrtanik, D., Zavrtanik, M., Zdziarski, A. A., Zech, A., Zhang, W., Zhdanov, V. I., Ziętara, K., Živec, M., and Zuriaga-Puig, J.

Subjects
High Energy Physics - Phenomenology, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract

Monochromatic gamma-ray signals constitute a potential smoking gun signature for annihilating or decaying dark matter particles that could relatively easily be distinguished from astrophysical or instrumental backgrounds. We provide an updated assessment of the sensitivity of the Cherenkov Telescope Array (CTA) to such signals, based on observations of the Galactic centre region as well as of selected dwarf spheroidal galaxies. We find that current limits and detection prospects for dark matter masses above 300 GeV will be significantly improved, by up to an order of magnitude in the multi-TeV range. This demonstrates that CTA will set a new standard for gamma-ray astronomy also in this respect, as the world's largest and most sensitive high-energy gamma-ray observatory, in particular due to its exquisite energy resolution at TeV energies and the adopted observational strategy focussing on regions with large dark matter densities. Throughout our analysis, we use up-to-date instrument response functions, and we thoroughly model the effect of instrumental systematic uncertainties in our statistical treatment. We further present results for other potential signatures with sharp spectral features, e.g.~box-shaped spectra, that would likewise very clearly point to a particle dark matter origin., Comment: 44 pages JCAP style (excluding author list and references), 19 figures; minor changes to match published version

Published
2024
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27. Chasing Gravitational Waves with the Cherenkov Telescope Array

Author

Green, Jarred Gershon, Carosi, Alessandro, Nava, Lara, Patricelli, Barbara, Schüssler, Fabian, Seglar-Arroyo, Monica, Consortium, Cta, Abe, Kazuki, Abe, Shotaro, Acharyya, Atreya, Adam, Remi, Aguasca-Cabot, Arnau, Agudo, Ivan, Alfaro, Jorge, Alvarez-Crespo, Nuria, Batista, Rafael Alves, Amans, Jean-Philippe, Amato, Elena, Ambrosino, Filippo, Angüner, Ekrem Oguzhan, Antonelli, Lucio Angelo, Aramo, Carla, Arcaro, Cornelia, Arrabito, Luisa, Asano, Katsuaki, Aschersleben, Jann, Ashkar, Halim, Stuani, Luiz Augusto, Baack, Dominik, Backes, Michael, Balazs, Csaba, Balbo, Matteo, Larriva, Andres Baquero, Martins, Victor Barbosa, de Almeida, Ulisses Barres, Barrio, Juan Abel, Bastieri, Denis, Batista, Pedro Ivo, Batković, Ivana, Batzofin, Rowan William, Baxter, Joshua Ryo, Beck, Geoffrey, Tjus, Julia Becker, Beiske, Lukas, Belardinelli, Daniele, Benbow, Wystan, Bernardini, Elisa, Medrano, Juan Bernete, Bernlöhr, Konrad, Berti, Alessio, Beshley, Vasyl, Bhattacharjee, Pooja, Bhattacharyya, Saptashwa, Bi, Baiyang, Biederbeck, Noah, Biland, Adrian, Bissaldi, Elisabetta, Blanch, Oscar, Blazek, Jiri, Boisson, Catherine, Bolmont, Julien, Bonnoli, Giacomo, Bordas, Pol, Bošnjak, Željka, Bradascio, Federica, Braiding, Catherine, Bronzini, Ettore, Brose, Robert, Brown, Anthony M., Brun, Francois, Brunelli, Giulia, Bulgarelli, Andrea, Burelli, Irene, Burmistrov, Leonid, Burton, Michael, Bylund, Tomas, Calisse, Paolo Gherardo, Campoy-Ordaz, Anna, Cantlay, Brandon Khan, Capalbi, Milvia, Caproni, Anderson, Capuzzo-Dolcetta, Roberto, Carlile, Colin, Caroff, Sami, Carosi, Roberto, Carrasco, Marie-Sophie, Cascone, Enrico, Cassol, Franca, Castrejon, Noelia, Catalani, Fernando, Cerasole, Davide, Cerruti, Matteo, Chaty, Sylvain, Chen, Andrew W, Chernyakova, Maria, Chiavassa, Andrea, Chudoba, Jiří, Araujo, Carlos Henrique Coimbra, Conforti, Vito, Conte, Francesco, Contreras, Jose Luis, Cossou, Christophe, Costa, Alessandro, Costantini, Heide, Cristofari, Pierre, Cuevas, Omar, Curtis-Ginsberg, Zachary, D'Amico, Giacomo, D'Ammando, Filippo, Dadina, Mauro, Dalchenko, Mykhailo, David, Ludovic, Davids, Isak Delberth, Dazzi, Francesco, De Angelis, Alessandro, de Lavergne, Mathieu de Bony, De Caprio, Vincenzo, De Cesare, Giovanni, Pino, Elisabete M. de Gouveia Dal, De Lotto, Barbara, de Lucia, Mario, de Menezes, Raniere, de Naurois, Mathieu, Wilhelmi, Emma de Oña, De Simone, Nicola, de Souza, Vitor, Del Peral, Luis, del Valle, Maria Victoria, Delagnes, Eric, Giler, Andres Gabriel Delgado, Delgado, Carlos, Dell'aiera, Michael, Della Ceca, Roberto, Della Valle, Massimo, Della Volpe, Domenico, Depaoli, Davide, Dettlaff, Antonios, Di Girolamo, Tristano, Di Piano, Ambra, Di Pierro, Federico, Di Tria, Riccardo, Di Venere, Leonardo, Díaz-Bahamondes, Christian, Dib, Claudio, Diebold, Sebastian, Dima, Razvan, Dinesh, Adithiya, Djannati-Ataï, Arache, Djuvsland, Julia Isabel, Dominguez, Alberto, Dominik, Rune Michael, Donini, Alice, Dorner, Daniela, Dörner, Julien, Doro, Michele, Anjos, Rita de Cassia dos, Dournaux, Jean-Laurent, Dravins, Dainis, Duangchan, Chaimongkol, Dubos, Coline, Ducci, Lozenzo, Dwarkadas, Vikram V., Ebr, Jan, Eckner, Christopher, Egberts, Kathrin, Einecke, Sabrina, Elsässer, Dominik, Emery, Gabriel, Godoy, Miguel Escobar, Escudero, Juan, Esposito, Paolo, Falceta-Gonçalves, Diego, Ramazani, Vandad Fallah, Faure, Alice, Fedorova, Elena, Fegan, Stephen, Feijen, Kirsty, Feng, Qi, Ferrand, Gilles, Ferrarotto, Fabio, Fiandrini, Emanuele, Fiasson, Armand, Fioretti, Valentina, Foffano, Luca, Guiteras, Lluis Font, Fontaine, Gerard, Fröse, Stefan, Fukami, Satoshi, Fukui, Yasuo, Funk, Stefan, Gaggero, Daniele, Galanti, Giorgio, Galaz, Gaspar, Gallant, Yves A., Gallozzi, Stefano, Gammaldi, Viviana, Gasbarra, Claudio, Gaug, Markus, Ghalumyan, Arsen, Gianotti, Fulvio, Giarrusso, Marina, Giglietto, Nicola, Giordano, Francesco, Giuliani, Andrea, Glicenstein, Jean-Francois, Glombitza, Jonas, Goldoni, Paolo, González, José Mauricio, González, Maria Magdalena, Coelho, Jaziel Goulart, Granot, Jonathan, Grasso, Dario, Haro, Roger Grau, Green, David, Greenshaw, Tim, Grolleron, Guillaume, Grube, Jeff, Gueta, Orel, Gunji, Shuichi, Hadasch, Daniela, Hamal, Petr, Hanlon, William, Hara, Satoshi, Harvey, Violet M., Hashiyama, Kazuaki, Hassan, Tarek, Heller, Matthieu, Cadena, Sergio Hernández, Hie, Jonathan, Hiroshima, Nagisa, Hnatyk, Bohdan, Hnatyk, Roman, Hoffmann, Dirk, Hofmann, Werner, Holler, Markus, Horan, Deirdre, Horvath, Pavel, Hovatta, Talvikki, Hrupec, Dario, Hussain, Saqib, Iarlori, Marco, Inada, Tomohiro, Incardona, Federico, Inome, Yusuke, Inoue, Susumu, Iocco, Fabio, Ishio, Kazuma, Jamrozy, Marek, Janecek, Petr, Jankowsky, Felix, Jarnot, Christian, Jean, Pierre, Martínez, Irene Jiménez, Jin, Weidong, Jocou, Laurent, Juramy-Gilles, Claire, Jurysek, Jakub, KALEKIN, Oleg, Kantzas, Dimitrios, Karas, Vladimir, Kaufmann, Sarah, Kerszberg, Daniel, Khelifi, Bruno, Kieda, David B, Kleiner, Tobias Kai, Kluźniak, Włodzimierz, Kobayashi, Yukiho, Kohri, Kazunori, Komin, Nukri, Kornecki, Paula, Kosack, Karl, Kubo, Hidetoshi, Kushida, Junko, La Barbera, Antonino, La Palombara, Nicola, Lainez, Maria, Lamastra, Alessandra, Lapington, Jon S, Lazarevic, Sanja, Lazendic-Galloway, Jasmina, Leach, Steven, Lemoine-Goumard, Marianne, Lenain, Jean-Philippe, Leto, Giuseppe, Leuschner, Fabian, Lindfors, Elina, Linhoff, Maximilian, Liodakis, Ioannis, Loïc, Lozach, Lombardi, Saverio, Longo, Francesco, López-Coto, Rubén, López-Moya, Marcos, López-Oramas, Alicia, Loporchio, Serena, Bahilo, Julio Lozano, Luque-Escamilla, Pedro L., Macias, Oscar, Maier, Gernot, Majumdar, Pratik, Malyshev, Denys, Malyshev, Dmitry, Mandat, Dusan, Manicò, Giulio, Marinos, Peter David, Markoff, Sera, Márquez, Isabel, Marquez, Patricia, Marsella, Giovanni, Martí, Josep, Martin, Pierrick, Martínez, Gustavo Augusto, Martínez, Manel, Martinez, Oibar, Marty, Christophe, Mas-Aguilar, Alvaro, Mastropietro, Michele, Maurin, Gilles, Max-Moerbeck, Walter, Mazin, Daniel, Melkumyan, David, Menchiari, Stefano, Mestre, Enrique, Meunier, Jean-Luc, Meyer, Dominique M. -A., Miceli, Davide, Michailidis, Miltiadis, Michałowski, Jerzy, Miener, Tjark, Miranda, Jose Miguel, Mitchell, Alison, Mizote, Masaya, Mizuno, Tsunefumi, Moderski, Rafal, Mohrmann, Lars, Molero, Miguel, Molfese, Cesare, Molina, Edgar, Montaruli, Teresa, Moralejo, Abelardo, Morcuende, Daniel, Morik, Katharina, Morselli, Aldo, Moulin, Emmanuel, Zamanillo, Victor Moya, Mukherjee, Reshmi, Munari, Kevin, Muraczewski, Adam, Muraishi, Hiroshi, Nakamori, Takeshi, Nayak, Amrit, Nemmen, Rodrigo, Nickel, Lukas, Niemiec, Jacek, Nieto, Daniel, Rosillo, Mireia Nievas, Nikołajuk, Marek, Nishijima, Kyoshi, Noda, Koji, Nosek, Dalibor, Novosyadlyj, Bohdan, Novotný, Vladimír, Nozaki, Seiya, O'Brien, Paul, Ohishi, Michiko, Ohtani, Yoshiki, Okumura, Akira, Olive, Jean-François, Olmi, Barbara, Ong, Rene A., Orienti, Monica, Orito, Reiko, Orlandini, Mauro, Orlando, Elena, Ostrowski, Michal, Otte, Nepomuk, Oya, Igor, Pagano, Isabella, Pagliaro, Antonio, Palatiello, Michele, Panebianco, Gabriele, Paredes, Josep M., Parmiggiani, Nicolò, Patel, Sonal Ramesh, Pavlović, Dijana, Pe'er, Asaf, Pech, Miroslav, Pecimotika, Mario, Peresano, Michele, Pérez-Romero, Judit, Peron, Giada, Persic, Massimo, Petrucci, Pierre-Olivier, Petruk, Oleh, Pfeifle, Felix, Pintore, Fabio, Pirola, Giorgio, Pittori, Carlotta, Plard, Cyann, Podobnik, Franjo, Pohl, Martin, Pons, Estelle, Prandini, Elisa, Prast, Julie, Principe, Giacomo, Priyadarshi, Chaitanya, Produit, Nicolas, Prokhorov, Dmitry, Pueschel, Elisa, Pühlhofer, Gerd, Pumo, Maria Letizia, Punch, Michael, Quirrenbach, Andreas, Raino, Silvia, Randazzo, Nunzio, Rando, Riccardo, Ravel, Thierry, Razzaque, Soebur, Regeard, Maxime, Reichherzer, Patrick, Reimer, Anita, Reimer, Olaf, Reisenegger, Andreas, Reposeur, Thierry, Reville, Brian, Rhode, Wolfgang, Ribó, Marc, Richtler, Tom, Rieger, Frank, Roache, Emmet, Fernandez, Gonzalo Rodriguez, Frías, Maria Dolores Rodríguez, Rodríguez-Vázquez, Juan José, Romano, Patrizia, Romeo, Giuseppe, Rosado, Jaime, Rowell, Gavin P, Rudak, Bronislaw, Ruiter, Ashley J., Rulten, Cameron Boyd, Russo, Federico, Sadeh, Iftach, Saha, Lab, Saito, Takayuki, Sakurai, Shunsuke, Salzmann, Heiko, Sanchez, David, Sanchez-Conde, Miguel, Sangiorgi, Pierluca, Sano, Hidetoshi, Santander, Marcos, Santangelo, Andrea, Santos-Lima, Reinaldo, Sanuy, Andreu, Šarić, Toni, Sarkar, Arkadipta, Sarkar, Subir, Saturni, Francesco Gabriele, Savchenko, Volodymyr, Scherer, Andres, Schipani, Pietro, Schleicher, Bernd, Schovanek, Petr, Schubert, Jan Lukas, Schwanke, Ullrich, Schwefer, Georg, Scuderi, Salvatore, Arroyo, Monica Seglar, Seitenzahl, Ivo, Sergijenko, Olga, Sguera, Vito, Shang, Ruo-Yu, Sharma, Pooja, Sidibe, Guereguin Der Sylvestre, Sidoli, Lara, Siejkowski, Hubert, Siqueira, Clarissa, Sizun, Patrick, Sliusar, Vitalii, Slowikowska, Agnieszka, Sol, Helene, Specovius, Andreas, Spencer, Samuel Timothy, Spiga, Daniele, Stamerra, Antonio, Stanič, Samo, Starecki, Tomasz, Starling, Rhaana, Steppa, Constantin, Stolarczyk, Thierry, Strišković, Jelena, Strzys, Marcel C., Suda, Yusuke, Suomijarvi, Tiina, Tak, Donggeun, Takahashi, Mitsunari, Takeishi, Ryuji, Tam, Pak-Hin Thomas, Tanaka, Shuta J, Tanaka, Takaaki, Terauchi, Kenta, Testa, Vincenzo, Tibaldo, Luigi, Tibolla, Omar, Torradeflot, Francesc, Torres, Diego F., Torresi, Eleonora, Tothill, Nick, Toussenel, Francois, Touzard, Victoria, Tramacere, Andrea, Travnicek, Petr, Tripodo, Giovanni, Truzzi, Stefano, Tsiahina, Adellain, Tutone, Antonio, Vacula, Martin, Vallage, Bertrand, Vallania, Piero, Vallés, Ramon, van Eldik, Christopher, van Scherpenberg, Juliane, Vandenbroucke, Justin, Vassiliev, Vladimir, Venault, Philippe, Ventura, Sofia, Vercellone, Stefano, Verna, Gaia, Viana, Aion, Viaux, Nicolás, Vigliano, Alessandro, Vignatti, Jonatan, Vigorito, Carlo francesco, Vitale, Vincenzo, Vodeb, Veronika, Voisin, Vincent, Vorobiov, Serguei, Voutsinas, Georgios Gerasimos, Vovk, Ievgen, Waegebaert, Vincent, Wagner, Stefan Joachim, Walter, Roland, Ward, Martin, Wechakama, Maneenate, White, Richard, Wierzcholska, Alicja, Will, Martin, Williams, David A., Wohlleben, Frederik, Wolter, Anna, Yamamoto, Tokonatsu, Yamazaki, Ryo, Yang, Lili, Yoshida, Tatsuo, Yoshikoshi, Takanori, Zacharias, Michael, Sanchez, Ricardo Zanmar, Zavrtanik, Danilo, Zavrtanik, Marko, Zdziarski, Andrzej A., Zech, Andreas, Zhdanov, Valery I., Ziȩtara, Krzysztof, Živec, Miha, and Zuriaga-Puig, Jaume

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The detection of gravitational waves from a binary neutron star merger by Advanced LIGO and Advanced Virgo (GW170817), along with the discovery of the electromagnetic counterparts of this gravitational wave event, ushered in a new era of multimessenger astronomy, providing the first direct evidence that BNS mergers are progenitors of short gamma-ray bursts (GRBs). Such events may also produce very-high-energy (VHE, > 100GeV) photons which have yet to be detected in coincidence with a gravitational wave signal. The Cherenkov Telescope Array (CTA) is a next-generation VHE observatory which aims to be indispensable in this search, with an unparalleled sensitivity and ability to slew anywhere on the sky within a few tens of seconds. New observing modes and follow-up strategies are being developed for CTA to rapidly cover localization areas of gravitational wave events that are typically larger than the CTA field of view. This work will evaluate and provide estimations on the expected number of of gravitational wave events that will be observable with CTA, considering both on- and off-axis emission. In addition, we will present and discuss the prospects of potential follow-up strategies with CTA., Comment: Presented at the 38th International Cosmic Ray Conference (ICRC 2023), 2023 (arXiv:2309.08219)

Published
2023

28. Curvature in the very-high energy gamma-ray spectrum of M87

Author

Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Bradascio, F., Brose, R., Brun, F., Bruno, B., Burger-Scheidlin, T. Bulik C., Bylund, T., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Collins, T., Cotter, G., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Fegan, S., Fontaine, G., Funk, S., Gabici, S., Glicenstein, J. F., Glombitza, J., Grolleron, G., Haerer, L., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Lypova, I., Luashvili, A., Mackey, J., Malyshev, D., Martí-Devesa, G., Marx, R., Mehta, A., Meyer, M., Mitchell, A., Moderski, R., Moghadam, M. O., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Panny, S., Panter, M., Parsons, R. D., Pensec, U., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reimer, A., Reimer, O., Ren, H., Reville, B., Rieger, F., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Sol, H., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Tsirou, M., van Eldik, C., Venter, C., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., Zilberman, P., and Zywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The radio galaxy M87 is a variable very-high energy (VHE) gamma-ray source, exhibiting three major flares reported in 2005, 2008, and 2010. Despite extensive studies, the origin of the VHE gamma-ray emission is yet to be understood. In this study, we investigate the VHE gamma-ray spectrum of M87 during states of high gamma-ray activity, utilizing 20.2$\,$ hours the H.E.S.S. observations. Our findings indicate a preference for a curved spectrum, characterized by a log-parabola model with extra-galactic background light (EBL) model above 0.3$\,$TeV at the 4$\sigma$ level, compared to a power-law spectrum with EBL. We investigate the degeneracy between the absorption feature and the EBL normalization and derive upper limits on EBL models mainly sensitive in the wavelength range 12.4$\,$$\mu$m - 40$\,$$\mu$m., Comment: 10 pages, 7 figures. Accepted for publication in A&A. Corresponding authors: Victor Barbosa Martins, Rahul Cecil, Iryna Lypova, Manuel Meyer, Perri Zilberman. Supplementary material: https://zenodo.org/records/10781524

Published
2024
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29. Orbital collapse and dual states of the $5g$ electrons in superheavy elements

Author

Tupitsyn, I. I., Savelyev, I. M., Kozhedub, Y. S., Telnov, D. A., Dulaev, N. K., Malyshev, A. V., Prokhorchuk, E. A., and Shabaev, V. M.

Subjects
Physics - Atomic Physics
Abstract

The problem of orbital collapse of the $5g$ and $6f$ electrons in atoms of superheavy elements (SHE) is considered. Previously, the presence of the orbital collapse was established for the $4f$ and $5f$ elements of the periodic table. Because of the large centrifugal term for the $f$ and $g$ electrons, the effective radial potential has two wells, one narrow and deep and the other wide but shallow. Depending on the external parameters, the electron can be either localized in the outer well with low binding energy and large average radius or in the inner one with higher energy and smaller radius. In this work, we demonstrate the existence of the orbital collapse for the $5g$ electrons when changing the total angular momentum $J$ of the atom. We also found that for some SHE elements, two different solutions of the same Dirac-Fock equations may coexist, with the $5g$ electron localized either in the inner or outer well. In both cases, the radial wave functions are nodeless. The problem of the dual-state coexistence is studied by the configuration-interaction method in the Dirac-Fock-Sturm orbital basis as well., Comment: 8 pages, 2 figures

Published
2024

30. Acceleration and transport of relativistic electrons in the jets of the microquasar SS 433

Author

Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaou, M., Breuhau, M., Brose, R., Brown, A. M., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Dai, S., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Dmytriiev, A., Doroshenko, V., Egberts, K., Einecke, S., Ernenwein, J. -P., Filipovic, M., Fontaine, G., Funk, S., Gabici, S., Ghafourizadeh, S., Giavitto, G., Glawion, D., Glicenstein, J. F., Grolleron, G., Haerer, L., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Jamrozy, M., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khatoon, R., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lenain, J. -P., Leuschner, F., Lohse, T., Luashvili, A., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Martí-Devesa, G., Marx, R., Mehta, A., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., Nakashima, K., de Naurois, M., Niemiec, J., Noel, A. Priyana, Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Ren, H., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Salzman, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Tsirou, M., Tsuji, N., Unbehaun, T., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

SS 433 is a microquasar, a stellar binary system with collimated relativistic jets. We observed SS 433 in gamma rays using the High Energy Stereoscopic System (H.E.S.S.), finding an energy-dependent shift in the apparent position of the gamma-ray emission of the parsec-scale jets. These observations trace the energetic electron population and indicate the gamma rays are produced by inverse-Compton scattering. Modelling of the energy-dependent gamma-ray morphology constrains the location of particle acceleration and requires an abrupt deceleration of the jet flow. We infer the presence of shocks on either side of the binary system at distances of 25 to 30 parsecs and conclude that self-collimation of the precessing jets forms the shocks, which then efficiently accelerate electrons., Comment: Submitted 20th Apr. 2023, published 25th January 2024 (accepted version)

Published
2024
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31. Resolving Galactic center GeV excess with MSP-like sources

Author

Malyshev, Dmitry V.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Excess of gamma rays around the Galactic center (GC) observed in the Fermi Large Area Telescope (LAT) data is one of the most intriguing features in the gamma-ray sky. The spherical morphology and the spectral energy distribution with a peak around a few GeV are consistent with emission from annihilation of dark matter particles. Other possible explanations include a distribution of millisecond pulsars (MSPs). One of the caveats of the MSP hypothesis is the relatively small number of associated MSPs near the GC. In this paper we perform a multi-class classification of Fermi-LAT sources using machine learning and determine the contribution from unassociated MSP-like sources near the GC. The spectral energy distribution, spatial morphology, and the source count distribution are consistent with expectations for a population of MSPs that can explain the gamma-ray excess. Possible caveats of the contribution from the unassociated MSP-like sources are discussed., Comment: 11 pages, 11 figures, 4 tables, probabilistic classification of sources is available online at https://zenodo.org/doi/10.5281/zenodo.10458464, v2: references and discussions added

Published
2024

32. TMD gluon density in nuclei versus experimental data on heavy flavor production at LHC

Author

Lipatov, A. V., Malyshev, M. A., Kotikov, A. V., and Chen, X.

Subjects
High Energy Physics - Phenomenology
Abstract

Analytical expressions for the Transverse Momentum Dependent (TMD, or unintegrated) gluon and sea quark densities in nuclei are derived at leading order of QCD running coupling. The calculations are performed in the framework of the rescaling model and Kimber-Martin-Ryskin (KMR) prescription, where the Bessel-inspired behavior of parton densities at small Bjorken $x$ values, obtained in the case of flat initial conditions in the double scaling QCD approximation, is applied. The derived expressions are used to evaluate the inclusive heavy flavor production in proton-lead collisions at the LHC. We find a good agreement of our results with latest experimental data collected by the CMS and ALICE Collaborations at $\sqrt s = 5.02$ GeV., Comment: 13 pages, 3 figures, 1 table

Published
2023

36. The study of x-ray spectrum of the Coma cluster

Author

Zadorozhna, L., Tugay, A., Prikhodko, O., Malyshev, D., Sahai, Y., Savchenko, D., and Pulatova, N.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

The X-ray spectrum of the Coma galaxy cluster was studied using the data from the XMM-Newton observatory. We combined 7 observations performed with the MOS camera of XMM-Newton in the 40'x 40' region centered at the Coma cluster. The analyzed observations were performed in 2000-2005 and have a total duration of 196 ksec. We focus on the analysis of the MOS camera spectra due to their lower affection by strong instrumental line-like background. The obtained spectrum was fitted with a model including contributions from the Solar system/Milky Way hot plasma and a power law X-ray background. The contribution of the instrumental background was modeled as a power law (not convolved with the effective area) and a number of Gaussian lines. The contribution from the Coma cluster was modeled with a single-temperature hot plasma emission. In addition, we searched for possible non-thermal radiation present in the vicinity of the center of the Coma cluster, originating e.g. from synchrotron emission of relativistic electrons on a turbulent magnetic field. We compared the results with previous works by other authors and spectra obtained from other instruments that operate in the similar energy range of 1-10 keV. Careful and detailed spectrum analysis shall be a necessary contribution to our future work - searching for axion-like particles' manifestations in the Coma cluster., Comment: 6 pages, 2 figures, 2 tables

Published
2023

37. Limits on the Primordial Black Holes Dark Matter with current and future missions

Author

Malyshev, Denys, Moulin, Emmanuel, and Santangelo, Andrea

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

In this proceeding we consider primordial black holes (PBHs) as a dark matter candidate. We discuss the existing limits on the fraction $f_{pbh}$ of the dark matter constituting of PBHs as a function of PBHs mass. The discussed limits cover almost all possible mass range with the currently only open window in $3\cdot 10^{16}-10^{18}$ g in which the PBHs can make up to 100% of the dark matter content of the universe. We present the estimates of the capabilities of the near-future instruments (Einstein Probe/WXT, SVOM/MXT) and discuss the potential of next-generation missions(Athena, THESEUS, eXTP) to probe this mass range. We discuss the targets most suitable for the PBH dark matter searches with these missions and the potential limiting factor of the systematics on the derived results., Comment: to appear in PoS (MULTIF2023)

Published
2023

38. Double parton scattering versus jet quenching

Author

Baranov, S. P., Lipatov, A. V., Malyshev, M. A., and Snigirev, A. M.

Subjects
Nuclear Theory, High Energy Physics - Phenomenology
Abstract

A novel observable, the double nuclear modification factor, is proposed to probe simultaneously the initial and final state effects in nucleus-nucleus collisions. An interesting competition between the combinatorial enhancement in the double parton scattering and the suppression due to parton energy loss can be observed in the production rate of two hard particles. In particular, the production of $J/\psi$ mesons in association with a $W$ boson is not suppressed but is enhanced in the region of moderate transverse momenta, unlike the case of unassociated (inclusive) $J/\psi$ production. At the same time, in the region of high enough transverse momenta the nuclear modification factor for associated $J/\psi+W$ production converges to that of unassociated $J/\psi$., Comment: 4 pages, 1 figure; Sec.II has been rewritten in a more clear manner; results are unchanged; matches journal version

Published
2023
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39. A New and Faster Representation for Counting Integer Points in Parametric Polyhedra

Author

Gribanov, D., Malyshev, D., Pardalos, P., and Zolotykh, N.

Subjects
Computer Science - Data Structures and Algorithms, Computer Science - Computational Geometry, Computer Science - Discrete Mathematics, Mathematics - Combinatorics
Abstract

In this paper, we consider the counting function $E_P(y) = |P_{y} \cap Z^{n_x}|$ for a parametric polyhedron $P_{y} = \{x \in R^{n_x} \colon A x \leq b + B y\}$, where $y \in R^{n_y}$. We give a new representation of $E_P(y)$, called a \emph{piece-wise step-polynomial with periodic coefficients}, which is a generalization of piece-wise step-polynomials and integer/rational Ehrhart's quasi-polynomials. It gives the fastest way to calculate $E_P(y)$ in certain scenarios. The most important cases are the following: 1) We show that, for the parametric polyhedron $P_y$ defined by a standard-form system $A x = y,\, x \geq 0$ with a fixed number of equalities, the function $E_P(y)$ can be represented by a polynomial-time computable function. In turn, such a representation of $E_P(y)$ can be constructed by an $poly\bigl(n, \|A\|_{\infty}\bigr)$-time algorithm; 2) Assuming again that the number of equalities is fixed, we show that integer/rational Ehrhart's quasi-polynomials of a polytope can be computed by FPT-algorithms, parameterized by sub-determinants of $A$ or its elements; 3) Our representation of $E_P$ is more efficient than other known approaches, if $A$ has bounded elements, especially if it is sparse in addition. Additionally, we provide a discussion about possible applications in the area of compiler optimization. In some "natural" assumptions on a program code, our approach has the fastest complexity bounds.

Published
2023

40. A search for $\mu^+\to e^+\gamma$ with the first dataset of the MEG II experiment

Author

MEG II collaboration, Afanaciev, K., Baldini, A. M., Ban, S., Baranov, V., Benmansour, H., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Chiarello, G., Corvaglia, A., Cuna, F., Maso, G. Dal, De Bari, A., De Gerone, M., Barusso, L. Ferrari, Francesconi, M., Galli, L., Gallucci, G., Gatti, F., Gerritzen, L., Grancagnolo, F., Grandoni, E. G., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Ieki, K., Ignatov, F., Ikeda, F., Iwamoto, T., Karpov, S., Kettle, P. -R., Khomutov, N., Kobayashi, S., Kolesnikov, A., Kravchuk, N., Krylov, V., Kuchinskiy, N., Kyle, W., Libeiro, T., Malyshev, V., Matsushita, A., Meucci, M., Mihara, S., Molzon, W., Mori, Toshinori, Nakao, M., Nicolò, D., Nishiguchi, H., Ochi, A., Ogawa, S., Onda, R., Ootani, W., Oya, A., Palo, D., Panareo, M., Papa, A., Pettinacci, V., Popov, A., Renga, F., Ritt, S., Rossella, M., Rozhdestvensky, A., Schwendimann, P., Shimada, K., Signorelli, G., Takahashi, M., Tassielli, G. F., Toyoda, K., Uchiyama, Y., Usami, M., Venturini, A., Vitali, B., Voena, C., Yamamoto, K., Yanai, K., Yonemoto, T., Yoshida, K., and Yudin, Yu. V.

Subjects
High Energy Physics - Experiment
Abstract

The MEG II experiment, based at the Paul Scherrer Institut in Switzerland, reports the result of a search for the decay $\mu^+\to e^+\gamma$ from data taken in the first physics run in 2021. No excess of events over the expected background is observed, yielding an upper limit on the branching ratio of B($\mu^+\to e^+\gamma$) < $7.5 \times 10^{-13}$ (90% C.L.). The combination of this result and the limit obtained by MEG gives B($\mu^+\to e^+\gamma$) < $3.1 \times 10^{-13}$ (90% C.L.), which is the most stringent limit to date. A ten-fold larger sample of data is being collected during the years 2022-2023, and data-taking will continue in the coming years., Comment: 10 pages, 6 figures. To be published in EPJC

Published
2023

41. Operation and performance of MEG II detector

Author

MEG II Collaboration, Afanaciev, K., Baldini, A. M., Ban, S., Baranov, V., Benmansour, H., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Chiarello, G., Corvaglia, A., Cuna, F., Maso, G. Dal, De Bari, A., De Gerone, M., Barusso, L. Ferrari, Francesconi, M., Galli, L., Gallucci, G., Gatti, F., Gerritzen, L., Grancagnolo, F., Grandoni, E. G., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Ieki, K., Ignatov, F., Ikeda, F., Iwamoto, T., Karpov, S., Kettle, P. -R., Khomutov, N., Kobayashi, S., Kolesnikov, A., Kravchuk, N., Krylov, V., Kuchinskiy, N., Kyle, W., Libeiro, T., Malyshev, V., Matsushita, A., Meucci, M., Mihara, S., Molzon, W., Mori, Toshinori, Morsani, F., Nakao, M., Nicolò, D., Nishiguchi, H., Ochi, A., Ogawa, S., Onda, R., Ootani, W., Oya, A., Palo, D., Panareo, M., Papa, A., Pettinacci, V., Popov, A., Raffaelli, F., Renga, F., Ritt, S., Rossella, M., Rozhdestvensky, A., Schwendimann, P., Shimada, K., Signorelli, G., Stoykov, A., Takahashi, M., Tassielli, G. F., Toyoda, K., Uchiyama, Y., Usami, M., Venturini, A., Vitali, B., Voena, C., Yamamoto, K., Yanai, K., Yonemoto, T., Yoshida, K., and Yudin, Yu. V.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The MEG II experiment, located at the Paul Scherrer Institut (PSI) in Switzerland, is the successor to the MEG experiment, which completed data taking in 2013. MEG II started fully operational data taking in 2021, with the goal of improving the sensitivity of the mu+ -> e+ gamma decay down to 6e-14 almost an order of magnitude better than the current limit. In this paper, we describe the operation and performance of the experiment and give a new estimate of its sensitivity versus data acquisition time., Comment: 42 pages, 55 figures. Submitted to EPJC

Published
2023

42. Discovery of a Radiation Component from the Vela Pulsar Reaching 20 Teraelectronvolts

Author

Collaboration, The H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Cangemi, F., Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, O., Cotter, G., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Dmytriiev, A., Egberts, K., Ernenwein, J. -P., Feijen, K., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Grondin, M. -H., Haerer, L., Haupt, M., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Stum, S. Le, Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Marinos, P., Martí-Devesa, G., Marx, R., Maurin, G., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Murach, T., Nakashima, K., de Naurois, M., Niemiec, J., Noel, A. Priyana, OBrien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Pita, S., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Schüssler, F., Schwanke, U., Shapopi, J. N. S., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, L., Steenkamp, R., Steinmassl, S., Steppa, C., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Tavernier, T., Terrier, R., Thorpe-Morgan, C., Tluczykont, M., Tsirou, M., Tsuji, N., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wagner, S. J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yassin, H., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zouari, S., Żywucka, N., Zanin, R., Kerr, M., Johnston, S., Shannon, R. M., and Smith, D. A.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Gamma-ray observations have established energetic isolated pulsars as outstanding particle accelerators and antimatter factories in the Galaxy. There is, however, no consensus regarding the acceleration mechanisms and the radiative processes at play, nor the locations where these take place. The spectra of all observed gamma-ray pulsars to date show strong cutoffs or a break above energies of a few gigaelectronvolt (GeV). Using the H.E.S.S. array of Cherenkov telescopes, we discovered a novel radiation component emerging beyond this generic GeV cutoff in the Vela pulsar's broadband spectrum. The extension of gamma-ray pulsation energies up to at least 20 teraelectronvolts (TeV) shows that Vela pulsar can accelerate particles to Lorentz factors higher than $4\times10^7$. This is an order of magnitude larger than in the case of the Crab pulsar, the only other pulsar detected in the TeV energy range. Our results challenge the state-of-the-art models for high-energy emission of pulsars while providing a new probe, i.e. the energetic multi-TeV component, for constraining the acceleration and emission processes in their extreme energy limit., Comment: 38 pages, 6 figures. This preprint has not undergone peer review or any post-submission improvements or corrections. The Version of Record of this article is published in Nature Astronomy, Nat Astron (2023), and is available online at https://doi.org/10.1038/s41550-023-02052-3

Published
2023
Full Text
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43. Autoregressive Neural Quantum States with Quantum Number Symmetries

Author

Malyshev, Aleksei, Arrazola, Juan Miguel, and Lvovsky, A. I.

Subjects
Quantum Physics, Condensed Matter - Disordered Systems and Neural Networks, Physics - Chemical Physics, Physics - Computational Physics
Abstract

Neural quantum states have established themselves as a powerful and versatile family of ansatzes for variational Monte Carlo simulations of quantum many-body systems. Of particular prominence are autoregressive neural quantum states (ANQS), which enjoy the expressibility of deep neural networks, and are equipped with a procedure for fast and unbiased sampling. Yet, the non-selective nature of autoregressive sampling makes incorporating quantum number symmetries challenging. In this work, we develop a general framework to make the autoregressive sampling compliant with an arbitrary number of quantum number symmetries. We showcase its advantages by running electronic structure calculations for a range of molecules with multiple symmetries of this kind. We reach the level of accuracy reported in previous works with more than an order of magnitude speedup and achieve chemical accuracy for all studied molecules, which is a milestone unreported so far. Combined with the existing effort to incorporate space symmetries, our approach expands the symmetry toolbox essential for any variational ansatz and brings the ANQS closer to being a competitive choice for studying challenging quantum many-body systems., Comment: 11 pages, 5 figures, 1 table

Published
2023

44. Role of Spatial Coherence in Diffractive Optical Neural Networks

Author

Filipovich, Matthew J., Malyshev, Aleksei, and Lvovsky, A. I.

Subjects
Physics - Optics, Electrical Engineering and Systems Science - Image and Video Processing
Abstract

Diffractive optical neural networks (DONNs) have emerged as a promising optical hardware platform for ultra-fast and energy-efficient signal processing for machine learning tasks, particularly in computer vision. Previous experimental demonstrations of DONNs have only been performed using coherent light. However, many real-world DONN applications require consideration of the spatial coherence properties of the optical signals. Here, we study the role of spatial coherence in DONN operation and performance. We propose a numerical approach to efficiently simulate DONNs under incoherent and partially coherent input illumination and discuss the corresponding computational complexity. As a demonstration, we train and evaluate simulated DONNs on the MNIST dataset of handwritten digits to process light with varying spatial coherence., Comment: 9 pages, 3 figures

Published
2023

45. Self-consistent description of HERA data at low $Q^2$ and soft hadron production at LHC

Author

Lipatov, A. V., Lykasov, G. I., and Malyshev, M. A.

Subjects
High Energy Physics - Phenomenology
Abstract

Using the analytical expression for transverse momentum dependent (TMD) gluon density in a proton, a self-consistent simultaneous description of low $Q^2$ data on proton structure function $F_2(x,Q^2)$, reduced cross section for the electron-proton deep inelastic scattering at HERA and soft hadron production in $pp$ collisions at the LHC is achieved in the framework of color dipole approach and modified quark-gluon string model., Comment: 12 pages, 6 figures

Published
2023

46. The radio to GeV picture of PSR B1259-63 during the 2021 periastron passage

Author

Chernyakova, M., Malyshev, D., van Soelen, B., Keague, S. Mc, O'Sullivan, S. P., and Buckley, D.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

PSR B1259-63 is a gamma-ray binary system with a radio pulsar orbiting an O9.5Ve star, LS 2883, with a period of ~3.4 yr. Close to the periastron the system is detected at all wavelengths, from radio to the TeV energies. The emission in this time period is believed to originate from the interaction of LS 2883 and pulsar's outflows. The observations of 4 periastra passages taken in 2010-2021 show strong correlation of the radio and X-ray lightcurves with two peaks just before and after the periastron. The observations of the latest 2021 periastron passage reveal the presence of the 3rd X-ray peak and subsequent disappearance of radio/X-ray flux correlation. In this paper we present the results of our optical, radio and X-ray observational campaigns on PSR B1259-63 performed in 2021 accompanied with the analysis of the publicly available GeV FERMI/LAT data. We compare the properties of different periastron passages, discuss the obtained results and show that they can be explained in terms of the 2-zone emission cone model proposed by us previously., Comment: accepted to MNRAS

Published
2023

47. Accelerated Proximal Iterative re-Weighted $\ell_1$ Alternating Minimization for Image Deblurring

Author

Adam, Tarmizi, Malyshev, Alexander, Hassan, Mohd Fikree, Mohamed, Nur Syarafina, and Salam, Md Sah Hj

Subjects
Mathematics - Optimization and Control
Abstract

The quadratic penalty alternating minimization (AM) method is widely used for solving the convex $\ell_1$ total variation (TV) image deblurring problem. However, quadratic penalty AM for solving the nonconvex nonsmooth $\ell_p$, $0 < p < 1$ TV image deblurring problems is less studied. In this paper, we propose two algorithms, namely proximal iterative re-weighted $\ell_1$ AM (PIRL1-AM) and its accelerated version, accelerated proximal iterative re-weighted $\ell_1$ AM (APIRL1-AM) for solving the nonconvex nonsmooth $\ell_p$ TV image deblurring problem. The proposed algorithms are derived from the proximal iterative re-weighted $\ell_1$ (IRL1) algorithm and the proximal gradient algorithm. Numerical results show that PIRL1-AM is effective in retaining sharp edges in image deblurring while APIRL1-AM can further provide convergence speed up in terms of the number of algorithm iterations and computational time.

Published
2023

48. Prospects for $\gamma$-ray observations of the Perseus galaxy cluster with the Cherenkov Telescope Array

Author

Consortium, The Cherenkov Telescope Array, Abe, K., Abe, S., Acero, F., Acharyya, A., Adam, R., Aguasca-Cabot, A., Agudo, I., Aguirre-Santaella, A., Alfaro, J., Alfaro, R., Alvarez-Crespo, N., Batista, R. Alves, Amans, J. -P., Amato, E., Angüner, E. O., Antonelli, L. A., Aramo, C., Araya, M., Arcaro, C., Arrabito, L., Asano, K., Ascasíbar, Y., Aschersleben, J., Ashkar, H., Stuani, L. Augusto, Baack, D., Backes, M., Baktash, A., Balazs, C., Balbo, M., Ballester, O., Larriva, A. Baquero, Martins, V. Barbosa, de Almeida, U. Barres, Barrio, J. A., Batista, P. I., Batkovic, I., Batzofin, R., Baxter, J., González, J. Becerra, Beck, G., Tjus, J. Becker, Benbow, W., Medrano, J. Bernete, Bernlöhr, K., Berti, A., Bertucci, B., Beshley, V., Bhattacharjee, P., Bhattacharyya, S., Bi, B., Biederbeck, N., Biland, A., Bissaldi, E., Biteau, J., Blanch, O., Blazek, J., Boisson, C., Bolmont, J., Bordas, P., Bosnjak, Z., Bottacini, E., Bradascio, F., Braiding, C., Bronzini, E., Brose, R., Brown, A. M., Brun, F., Brunetti, G., Bucciantini, N., Bulgarelli, A., Burelli, I., Burmistrov, L., Burton, M., Bylund, T., Calisse, P. G., Campoy-Ordaz, A., Cantlay, B. K., Capalbi, M., Caproni, A., Capuzzo-Dolcetta, R., Caraveo, P., Caroff, S., Carosi, R., Carquin, E., Carrasco, M. -S., Cascone, E., Cassol, F., Castro-Tirado, A. J., Cerasole, D., Cerruti, M., Chadwick, P., Chaty, S., Chen, A. W., Chernyakova, M., Chiavassa, A., Chudoba, J., Chytka, L., Cifuentes, A., Araujo, C. H. Coimbra, Conforti, V., Conte, F., Contreras, J. L., Cortina, J., Costa, A., Costantini, H., Cotter, G., Cristofari, P., Cuevas, O., Curtis-Ginsberg, Z., D'Amico, G., D'Ammando, F., Dalchenko, M., Dazzi, F., de Lavergne, M. de Bony, De Caprio, V., Laadim, F. De Frondat, Pino, E. M. de Gouveia Dal, De Lotto, B., De Lucia, M., De Martino, D., de Menezes, R., de Naurois, M., De Simone, N., de Souza, V., del Valle, M. V., Delagnes, E., Giler, A. G. Delgado, Delgado, C., Dell'aiera, M., della Volpe, D., Depaoli, D., Di Girolamo, T., Di Piano, A., Di Pierro, F., Di Tria, R., Di Venere, L., Diebold, S., Djannati-Ataï, A., Djuvsland, J., Dominik, R. M., Donini, A., Dorner, D., Dörner, J., Doro, M., Anjos, R. D. C. dos, Dournaux, J. -L., Duangchan, C., Dubos, C., Dumora, D., Dwarkadas, V. V., Ebr, J., Eckner, C., Egberts, K., Einecke, S., Elsässer, D., Emery, G., Godoy, M. Escobar, Escudero, J., Esposito, P., Ettori, S., Evoli, C., Falceta-Goncalves, D., Ramazani, V. Fallah, Fattorini, A., Faure, A., Fedorova, E., Fegan, S., Feijen, K., Feng, Q., Ferrand, G., Ferrarotto, F., Fiandrini, E., Fiasson, A., Filipovic, M., Fioretti, V., Foffano, L., Guiteras, L. Font, Fontaine, G., Fröse, S., Fukazawa, Y., Fukui, Y., Gaggero, D., Galanti, G., Gallozzi, S., Gammaldi, V., Garczarczyk, M., Gasbarra, C., Gasparrini, D., Gaug, M., Ghalumyan, A., Gianotti, F., Giarrusso, M., Giesbrecht, J., Giglietto, N., Giordano, F., Glicenstein, J. -F., Göksu, H., Goldoni, P., González, J. M., González, M. M., Coelho, J. Goulart, Granot, J., Grau, R., Gréaux, L., Green, D., Green, J. G., Grenier, I., Grolleron, G., Grube, J., Gueta, O., Hackfeld, J., Hadasch, D., Hamal, P., Hanlon, W., Hara, S., Harvey, V. M., Hassan, T., Heckmann, L., Heller, M., Cadena, S. Hernández, Hervet, O., Hie, J., Hiroshima, N., Hnatyk, B., Hnatyk, R., Hoang, J., Hoffmann, D., Hofmann, W., Holder, J., Horan, D., Horvath, P., Hrupec122, D., Hütten, M., Iarlori, M., Inada, T., Incardona, F., Inoue, S., Iocco, F., Iori, M., Jamrozy, M., Janecek, P., Jankowsky, F., Jarnot, C., Jean, P., Martínez, I. Jiménez, Jin, W., Juramy-Gilles, C., Jurysek, J., Kagaya, M., Kantzas, D., Karas, V., Katagiri, H., Kataoka, J., Kaufmann, S., Kerszberg, D., Khélifi, B., Kissmann, R., Kleiner, T., Kluge, G., Kluźniak, W., Knödlseder, J., Kobayashi, Y., Kohri, K., Komin, N., Kornecki, P., Kosack, K., Kowal, G., Kubo, H., Kushida, J., La Barbera, A., La Palombara, N., Láinez, M., Lamastra, A., Lapington, J., Laporte, P., Lazarević, S., Leitgeb, F., Lemoine-Goumard, M., Lenain, J. -P., Leone, F., Leto, G., Leuschner, F., Lindfors, E., Linhoff, M., Liodakis, I., Lombardi, S., Longo, F., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Luque-Escamilla, P. L., Macias, O., Mackey, J., Majumdar, P., Malyshev, D., Mandat, D., Manganaro, M., Manicò, G., Mariotti, M., Markoff, S., Márquez, I., Marquez, P., Marsella, G., Martínez, G. A., Martínez, M., Martinez, O., Marty, C., Mas-Aguilar, A., Mastropietro, M., Maurin, G., Mazin, D., Melkumyan, D., Mello, A. J. T. S., Meunier, J. -L., Meyer, D. M. -A., Meyer, M., Miceli, D., Michailidis, M., Michałowski, J., Miener, T., Miranda, J. M., Mitchell, A., Mizote, M., Mizuno, T., Moderski, R., Molero, M., Molfese, C., Molina, E., Montaruli, T., Morcuende, D., Morik, K., Morlino, G., Morselli, A., Moulin, E., Zamanillo, V. Moya, Munari, K., Murach, T., Muraczewski, A., Muraishi, H., Nagataki, S., Nakamori, T., Nemmen, R., Neyroud, N., Nickel, L., Niemiec, J., Nieto, D., Rosillo, M. Nievas, Nikołajuk, M., Nishijima, K., Noda, K., Nosek, D., Novotny, V., Nozaki, S., O'Brien, P., Ohishi, M., Ohtani, Y., Okumura, A., Olive, J. -F., Olmi, B., Ong, R. A., Orienti, M., Orito, R., Orlandini, M., Orlando, E., Ostrowski, M., Oya, I., Pagliaro, A., Palatiello, M., Panebianco, G., Paneque, D., Pantaleo, F. R., Paoletti, R., Paredes, J. M., Parmiggiani, N., Patel, S. R., Patricelli, B., Pavlović, D., Pech, M., Pecimotika, M., Pensec, U., Peresano, M., Pérez-Romero, J., Peron, G., Persic, M., Petrucci, P. -O., Petruk, O., Piano, G., Pierre, E., Pietropaolo, E., Pintore, F., Pirola, G., Pita, S., Plard, C., Podobnik, F., Pohl, M., Polo, M., Pons, E., Ponti, G., Prandini, E., Prast, J., Principe, G., Priyadarshi, C., Produit, N., Pueschel, E., Pühlhofer, G., Pumo, M. L., Punch, M., Queiroz, F., Quirrenbach, A., Rainò, S., Rando, R., Razzaque, S., Recchia, S., Regeard, M., Reichherzer, P., Reimer, A., Reimer, O., Reisenegger, A., Rhode, W., Ribeiro, D., Ribó, M., Richtler, T., Rico, J., Rieger, F., Righi, C., Riitano, L., Rizi, V., Roache, E., Fernandez, G. Rodriguez, Rodríguez-Vázquez, J. J., Romano, P., Romeo, G., Rosado, J., de Leon, A. Rosales, Rowell, G., Rudak, B., Rulten, C. B., Russo, F., Sadeh, I., Saha, L., Saito, T., Salzmann, H., Sanchez, D., Sánchez-Conde, M., Sangiorgi, P., Sano, H., Santander, M., Santangelo, A., Santos-Lima, R., Sanuy, A., Šarić, T., Sarkar, A., Sarkar, S., Satalecka, K., Saturni, F. G., Savchenko, V., Scherer, A., Schipani, P., Schleicher, B., Schubert, J. L., Schussler, F., Schwanke, U., Schwefer, G., Arroyo, M. Seglar, Seiji, S., Semikoz, D., Sergijenko, O., Servillat, M., Sguera, V., Shang, R. Y., Sharma, P., Siejkowski, H., Sinha, A., Siqueira, C., Sliusar, V., Slowikowska, A., Sol, H., Specovius, A., Spencer, S. T., Spiga, D., Stamerra, A., Stanič, S., Starecki, T., Starling, R., Stawarz, Ł., Steppa, C., Stolarczyk, T., Strišković, J., Suda, Y., Suomijärvi, T., Tajima, H., Tak, D., Takahashi, M., Takeishi, R., Tanaka, S. J., Tavernier, T., Tejedor, L. A., Terauchi, K., Terrier, R., Teshima, M., Tian, W. W., Tibaldo, L., Tibolla, O., Torradeflot, F., Torres, D. F., Torresi, E., Tosti, G., Tosti, L., Tothill, N., Toussenel, F., Touzard, V., Tramacere, A., Travnicek, P., Tripodo, G., Truzzi, S., Tsiahina, A., Tutone, A., Vacula, M., Vallage, B., Vallania, P., van Eldik, C., van Scherpenberg, J., Vandenbroucke, J., Vassiliev, V., Acosta, M. Vázquez, Vecchi, M., Ventura, S., Vercellone, S., Verna, G., Viana, A., Viaux, N., Vigliano, A., Vigorito, C. F., Vitale, V., Vodeb, V., Voisin, V., Vorobiov, S., Voutsinas, G., Vovk, I., Vuillaume, T., Wagner, S. J., Walter, R., Wechakama, M., White, R., Wierzcholska, A., Will, M., Williams, D. A., Wohlleben, F., Wolter, A., Yamamoto, T., Yamazaki, R., Yoshida, T., Yoshikoshi, T., Zacharias, M., Zaharijas, G., Zavrtanik, D., Zavrtanik, M., Zdziarski, A. A., Zech, A., Zhdanov, V. I., Živec, M., Zuriaga-Puig, J., and Luque, P. De la Torre

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Phenomenology
Abstract

Galaxy clusters are expected to be dark matter (DM) reservoirs and storage rooms for the cosmic-ray protons (CRp) that accumulate along the cluster's formation history. Accordingly, they are excellent targets to search for signals of DM annihilation and decay at gamma-ray energies and are predicted to be sources of large-scale gamma-ray emission due to hadronic interactions in the intracluster medium. We estimate the sensitivity of the Cherenkov Telescope Array (CTA) to detect diffuse gamma-ray emission from the Perseus galaxy cluster. We perform a detailed spatial and spectral modelling of the expected signal for the DM and the CRp components. For each, we compute the expected CTA sensitivity. The observing strategy of Perseus is also discussed. In the absence of a diffuse signal (non-detection), CTA should constrain the CRp to thermal energy ratio within the radius $R_{500}$ down to about $X_{500}<3\times 10^{-3}$, for a spatial CRp distribution that follows the thermal gas and a CRp spectral index $\alpha_{\rm CRp}=2.3$. Under the optimistic assumption of a pure hadronic origin of the Perseus radio mini-halo and depending on the assumed magnetic field profile, CTA should measure $\alpha_{\rm CRp}$ down to about $\Delta\alpha_{\rm CRp}\simeq 0.1$ and the CRp spatial distribution with 10% precision. Regarding DM, CTA should improve the current ground-based gamma-ray DM limits from clusters observations on the velocity-averaged annihilation cross-section by a factor of up to $\sim 5$, depending on the modelling of DM halo substructure. In the case of decay of DM particles, CTA will explore a new region of the parameter space, reaching models with $\tau_{\chi}>10^{27}$s for DM masses above 1 TeV. These constraints will provide unprecedented sensitivity to the physics of both CRp acceleration and transport at cluster scale and to TeV DM particle models, especially in the decay scenario., Comment: 93 pages (including author list, appendix and references), 143 figures. Submitted to JCAP

Published
2023
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49. Analysis Methods for Gamma-ray Astronomy

Author

Malyshev, Denys and Mohrmann, Lars

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

The launch of the Fermi satellite in 2008, with its Large Area Telescope (LAT) on board, has opened a new era for the study of gamma-ray sources at GeV ($10^9$ eV) energies. Similarly, the commissioning of the third generation of imaging atmospheric Cherenkov telescopes (IACTs) - H.E.S.S., MAGIC, and VERITAS - in the mid-2000's has firmly established the field of TeV ($10^{12}$ eV) gamma-ray astronomy. Together, these instruments have revolutionised our understanding of the high-energy gamma-ray sky, and they continue to provide access to it over more than six decades in energy. In recent years, the ground-level particle detector arrays HAWC, Tibet, and LHAASO have opened a new window to gamma rays of the highest energies, beyond 100 TeV. Soon, next-generation facilities such as CTA and SWGO will provide even better sensitivity, thus promising a bright future for the field. In this chapter, we provide a brief overview of methods commonly employed for the analysis of gamma-ray data, focusing on those used for Fermi-LAT and IACT observations. We describe the standard data formats, explain event reconstruction and selection algorithms, and cover in detail high-level analysis approaches for imaging and extraction of spectra, including aperture photometry as well as advanced likelihood techniques., Comment: 56 pages, 12 figures. Invited chapter for "Handbook of X-ray and Gamma-ray Astrophysics" (Eds. C. Bambi and A. Santangelo, Springer Singapore, expected in 2023)

Published
2023
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50. Extreme drought impacts have been underestimated in grasslands and shrublands globally.

Author

Maestre, Fernando, Power, Sally, Yu, Qiang, Felton, Andrew, Munson, Seth, Luo, Yiqi, Abdoli, Hamed, Abedi, Mehdi, Alados, Concepción, Alberti, Juan, Alon, Moshe, An, Hui, Anacker, Brian, Anderson, Maggie, Auge, Harald, Bachle, Seton, Bahalkeh, Khadijeh, Bahn, Michael, Batbaatar, Amgaa, Bauerle, Taryn, Beard, Karen, Behn, Kai, Beil, Ilka, Biancari, Lucio, Blindow, Irmgard, Bondaruk, Viviana, Borer, Elizabeth, Bork, Edward, Bruschetti, Carlos, Byrne, Kerry, Cahill, James, Calvo, Dianela, Carbognani, Michele, Cardoni, Augusto, Carlyle, Cameron, Castillo-Garcia, Miguel, Chang, Scott, Chieppa, Jeff, Cianciaruso, Marcus, Cohen, Ofer, Cordeiro, Amanda, Cusack, Daniela, Dahlke, Sven, Daleo, Pedro, Dietterich, Lee, S Doherty, Tim, Dubbert, Maren, Ebeling, Anne, Eisenhauer, Nico, Fischer, Felícia, Forte, Tai, Gebauer, Tobias, Gozalo, Beatriz, Greenville, Aaron, Guidoni-Martins, Karlo, Hannusch, Heather, Vatsø Haugum, Siri, Hautier, Yann, Hefting, Mariet, Henry, Hugh, Hoss, Daniela, Ingrisch, Johannes, Iribarne, Oscar, Isbell, Forest, Johnson, Yari, Jordan, Samuel, Kelly, Eugene, Kimmel, Kaitlin, Kreyling, Juergen, Kröel-Dulay, György, Kröpfl, Alicia, Kübert, Angelika, Kulmatiski, Andrew, Lamb, Eric, Larsen, Klaus, Larson, Julie, Lawson, Jason, Leder, Cintia, Linstädter, Anja, Liu, Jielin, Liu, Shirong, Lodge, Alexandra, Longo, Grisel, Loydi, Alejandro, Luan, Junwei, Curtis Lubbe, Frederick, Macfarlane, Craig, Mackie-Haas, Kathleen, Malyshev, Andrey, Maturano-Ruiz, Adrián, Merchant, Thomas, Metcalfe, Daniel, Mori, Akira, Mudongo, Edwin, Newman, Gregory, Nielsen, Uffe, Nimmo, Dale, Niu, Yujie, Nobre, Paola, and OConnor, Rory

Subjects
Drought-Net, International Drought Experiment, climate extreme, productivity, Droughts, Ecosystem, Grassland, Carbon Cycle, Climate Change, Receptor Protein-Tyrosine Kinases
Abstract

Climate change is increasing the frequency and severity of short-term (~1 y) drought events-the most common duration of drought-globally. Yet the impact of this intensification of drought on ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in the severity and duration of drought studied, and differences among ecosystems in vegetation, edaphic and climatic attributes that can mediate drought impacts. To overcome these problems and better identify the factors that modulate drought responses, we used a coordinated distributed experiment to quantify the impact of short-term drought on grassland and shrubland ecosystems. With a standardized approach, we imposed ~a single year of drought at 100 sites on six continents. Here we show that loss of a foundational ecosystem function-aboveground net primary production (ANPP)-was 60% greater at sites that experienced statistically extreme drought (1-in-100-y event) vs. those sites where drought was nominal (historically more common) in magnitude (35% vs. 21%, respectively). This reduction in a key carbon cycle process with a single year of extreme drought greatly exceeds previously reported losses for grasslands and shrublands. Our global experiment also revealed high variability in drought response but that relative reductions in ANPP were greater in drier ecosystems and those with fewer plant species. Overall, our results demonstrate with unprecedented rigor that the global impacts of projected increases in drought severity have been significantly underestimated and that drier and less diverse sites are likely to be most vulnerable to extreme drought.

Published
2024

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