| 1. |
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| 2. |
- Akiba, K., et al.
(författare)
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LHC forward physics
- 2016
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Ingår i: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 43:11
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Obers, Niels A., et al.
(författare)
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Quantum gravity phenomenology at the dawn of the multi-messenger era—A review
- 2022
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Ingår i: Progress in Particle and Nuclear Physics. - : Elsevier BV. - 0146-6410 .- 1873-2224. ; 125
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Forskningsöversikt (refereegranskat)abstract
- The exploration of the universe has recently entered a new era thanks to the multi-messenger paradigm, characterized by a continuous increase in the quantity and quality of experimental data that is obtained by the detection of the various cosmic messengers (photons, neutrinos, cosmic rays and gravitational waves) from numerous origins. They give us information about their sources in the universe and the properties of the intergalactic medium. Moreover, multi-messenger astronomy opens up the possibility to search for phenomenological signatures of quantum gravity. On the one hand, the most energetic events allow us to test our physical theories at energy regimes which are not directly accessible in accelerators; on the other hand, tiny effects in the propagation of very high energy particles could be amplified by cosmological distances. After decades of merely theoretical investigations, the possibility of obtaining phenomenological indications of Planck-scale effects is a revolutionary step in the quest for a quantum theory of gravity, but it requires cooperation between different communities of physicists (both theoretical and experimental). This review, prepared within the COST Action CA18108 “Quantum gravity phenomenology in the multi-messenger approach”, is aimed at promoting this cooperation by giving a state-of-the art account of the interdisciplinary expertise that is needed in the effective search of quantum gravity footprints in the production, propagation and detection of cosmic messengers.
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| 4. |
- Szczurek, Antoni, et al.
(författare)
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Diffractive exclusive production of heavy quark pairs at high energy proton-proton collisions
- 2010
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Ingår i: Proceedings of Science.
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Konferensbidrag (refereegranskat)abstract
- We discuss exclusive double diffractive (EDD) production of heavy quark - heavy antiquark pairs at high energies. Differential distributions for cc̄ at √s = 1.96 GeV and for bb̄ at √s = 14 TeV are shown and discussed. Irreducible leading-order bb̄ background to Higgs production is calculated in several kinematical variables. The signal-to-background ratio is shown and several improvements are suggested.
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| 5. |
- Bonilla, Cesar, et al.
(författare)
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Collider signatures of vector-like fermions from a flavor symmetric model
- 2022
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; 2022:1
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Tidskriftsartikel (refereegranskat)abstract
- We propose a model with two Higgs doublets and several SU(2) scalar singlets with a global non-Abelian flavor symmetry Q6× Z2. This discrete group accounts for the observed pattern of fermion masses and mixing angles after spontaneous symmetry breaking. In this scenario only the third generation of fermions get their masses as in the Standard Model (SM). The masses of the remaining fermions are generated through a seesaw-like mechanism. To that end, the matter content of the model is enlarged by introducing electrically charged vector-like fermions (VLFs), right handed Majorana neutrinos and several SM scalar singlets. Here we study the processes involving VLFs that are within the reach of the Large Hadron Collider (LHC). We perform collider studies for vector-like leptons (VLLs) and vector-like quarks (VLQs), focusing on double production channels for both cases, while for VLLs single production topologies are also included. Utilizing genetic algorithms for neural network optimization, we determine the statistical significance for a hypothetical discovery at future LHC runs. In particular, we show that we can not safely exclude VLLs for masses greater than 200 GeV. For VLQ’s in our model, we show that we can probe their masses up to 3.8 TeV, if we take only into account the high-luminosity phase of the LHC. Considering Run-III luminosities, we can also exclude VLQs for masses up to 3.4 TeV. We also show how the model with predicted VLL masses accommodates the muon anomalous magnetic moment.
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| 6. |
- Bonilla, Cesar, et al.
(författare)
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Fermion mass hierarchy in an extended left-right symmetric model
- 2023
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; 2023:12
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Tidskriftsartikel (refereegranskat)abstract
- We present a Left-Right symmetric model that provides an explanation for the mass hierarchy of the charged fermions within the framework of the Standard Model. This explanation is achieved through the utilization of both tree-level and radiative seesaw mechanisms. In this model, the tiny masses of the light active neutrinos are generated via a three-loop radiative inverse seesaw mechanism, with Dirac and Majorana submatrices arising at one-loop level. To the best of our knowledge, this is the first example of the inverse seesaw mechanism being implemented with both submatrices generated at one- loop level. The model contains a global U(1) X symmetry which, after its spontaneous breaking, allows for the stabilization of the Dark Matter (DM) candidates. We show that the electroweak precision observables, the electron and muon anomalous magnetic moments as well as the Charged Lepton Flavor Violating decays, μ → eγ, are consistent with the current experimental limits. In addition, we analyze the implications of the model for the 95 GeV diphoton excess recently reported by the CMS collaboration and demonstrate that such anomaly could be easily accommodated. Finally, we discuss qualitative aspects of DM in the considered model.
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| 7. |
- Bonilla, Cesar, et al.
(författare)
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Gravitational waves from a scotogenic two-loop neutrino mass model
- 2024
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Ingår i: Physical Review D. - 2470-0010. ; 109:9
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Tidskriftsartikel (refereegranskat)abstract
- We propose a framework to account for neutrino masses at the two-loop level. This mechanism introduces new scalars and Majorana fermions to the Standard Model. It assumes the existence of a global U(1)×Z2 symmetry which after partial breaking provides the stability of the dark matter candidates of the theory. The rich structure of the potential allows for the possibility of first-order phase transitions (FOPTs) in the early Universe which can lead to the generation of primordial gravitational waves. Taking into account relevant constraints from lepton flavor violation, neutrino physics, as well as the trilinear Higgs couplings at next-to-leading order accuracy, we have found a wide range of possible FOPTs which are strong enough to be probed at the proposed gravitational-wave interferometer experiments such as LISA.
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| 8. |
- Bull, Philip, et al.
(författare)
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Beyond ΛCDM : Problems, solutions, and the road ahead
- 2016
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Ingår i: Physics of the Dark Universe. - : Elsevier BV. - 2212-6864. ; 12, s. 56-99
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Tidskriftsartikel (refereegranskat)abstract
- Despite its continued observational successes, there is a persistent (and growing) interest in extending cosmology beyond the standard model, Lambda CDM. This is motivated by a range of apparently serious theoretical issues, involving such questions as the cosmological constant problem, the particle nature of dark matter, the validity of general relativity on large scales, the existence of anomalies in the CMB and on small scales, and the predictivity and testability of the inflationary paradigm. In this paper, we summarize the current status of Lambda CDM as a physical theory, and review investigations into possible alternatives along a number of different lines, with a particular focus on highlighting the most promising directions. While the fundamental problems are proving reluctant to yield, the study of alternative cosmologies has led to considerable progress, with much more to come if hopes about forthcoming high-precision observations and new theoretical ideas are fulfilled.
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| 9. |
- Csörgő, T., et al.
(författare)
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Convergence properties of Lévy expansions : Implications for odderon and proton structure
- 2018
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Konferensbidrag (refereegranskat)abstract
- We detail here the convergence properties of a new model-independent imaging method, the Lévy expansion, that seems to play an important role in the analysis of the differential cross section of elastic hadron-hadron scattering. We demonstrate, how our earlier results concerning the Odderon effects in the differential cross-section of elastic proton-proton and proton-antiproton scattering as well as those related to apparent sub-structures inside the protons were obtained in a convergent and stable manner.
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| 10. |
- Csörgő, Tamás, et al.
(författare)
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Convergence properties of Lévy expansions: implications for Odderon and proton structure
- 2019
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X. ; 206, s. 06007-06007
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Tidskriftsartikel (refereegranskat)abstract
- We detail here the convergence properties of a new model-independent imaging method, the Lévy expansion, that seems to play an important role in the analysis of the differential cross section of elastic hadron-hadron scattering.We demonstrate, how our earlier results concerning the Odderon effects in the differential cross-section of elastic proton-proton and proton-antiproton scattering as well as those related to apparent sub-structures inside the protons were obtained in a convergent and stable manner.
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| 11. |
- Csörgő, T., et al.
(författare)
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Evidence of Odderon-exchange from scaling properties of elastic scattering at TeV energies
- 2021
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 81:2
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Tidskriftsartikel (refereegranskat)abstract
- We study the scaling properties of the differential cross section of elastic proton–proton (pp) and proton–antiproton (pp¯) collisions at high energies. We introduce a new scaling function, that scales – within the experimental errors – all the ISR data on elastic pp scattering from s=23.5–62.5 GeV to the same universal curve. We explore the scaling properties of the differential cross-sections of the elastic pp and pp¯ collisions in a limited TeV energy range. Rescaling the TOTEM pp data from s=7 TeV to 2.76 and 1.96 TeV, and comparing it to D0 pp¯ data at 1.96 TeV, our results provide an evidence for a t-channel Odderon exchange at TeV energies, with a significance of at least 6.26σ. We complete this work with a model-dependent evaluation of the domain of validity of the new scaling and its violations. We find that the H(x) scaling is valid, model dependently, within 200GeV≤s≤8 TeV, with a - t range gradually narrowing with decreasing colliding energies.
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| 12. |
- Csörgő, T., et al.
(författare)
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Lévy imaging of elastic hadron–hadron scattering : Odderon and inner structure of the proton∗
- 2019
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - 1899-2358. ; 12:4, s. 779-785
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Tidskriftsartikel (refereegranskat)abstract
- A novel model-independent Lévy imaging method is employed for reconstruction of the elastic pp and pp¯ scattering amplitudes at low and high energies. The four-momentum transfer t-dependent elastic slope B(t), the nuclear phase φ(t) as well as the excitation function of the shadow profile P(b) have been extracted from data at ISR, Tevatron and the LHC energies. We found qualitative differences in properties of B(t) and φ(t) between pp and for pp¯ collisions that indicate an odderon effect. A proton substructure has also been identified and found to have two different sizes, comparable to that of a dressed quark at the ISR and a dressed diquark at the LHC energies, respectively.
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| 13. |
- Csörgo, T., et al.
(författare)
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Lévy imaging of elastic scattering and proton hollowness at 13 TeV
- 2019
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Ingår i: European Physical Society Conference on High Energy Physics (EPS-HEP2019). - Trieste, Italy : Sissa Medialab. - 1824-8039. ; 364
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Konferensbidrag (refereegranskat)abstract
- The shape of elastic differential cross section within and beyond the diffractive cone at 13 TeV pp collision energy has been shown to be precisely described by the Lévy series expansion in whole available range of momentum transfers. This way, the crucial information about the real and imaginary parts of the elastic amplitude has been obtained resulting in precision reconstruction of the proton inelasticity profile. We have found that the profile function P(b) undergoes a qualitative change at √s ≈ 7 TeV collision energy. At small values of the impact parameter b a P(b) ≈ 1 plateaux develops, which becomes depressed at larger energies, such that a shallow minimum is formed near b = 0. We have evaluated the corresponding error bar and found such a hotly debated proton hollowness (or “black-ring”) effect with beyond 5σ significance.
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| 14. |
- Csörgő, T., et al.
(författare)
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Model-Independent Femtoscopic Lévy Imaging for Elastic Proton-Proton Scattering
- 2020
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Ingår i: Physics of Particles and Nuclei. - 1063-7796. ; 51:3, s. 227-231
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Tidskriftsartikel (refereegranskat)abstract
- A model independent Lévy expansion method is introduced to describe nearly Lévy shaped squared moduli of Fourier transforms. We apply this method to precisely characterize the most recent elastic scattering data of proton-proton collisions at $$\sqrt s = 13$$ TeV. The results reveal a substructure of protons, which is found to be significantly larger and darker in high energy proton-proton collisions at the TeV scale, as compared to a rather faint and apparently overlooked substructure, that we also identify in elastic proton-proton scattering at the ISR energy range of $$\sqrt s = 23{\kern 1pt} - {\kern 1pt} 62$$ GeV.
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| 15. |
- Csörgő, T., et al.
(författare)
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Odderon and proton substructure from a model-independent Lévy imaging of elastic pp and pp¯ collisions
- 2019
-
Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 79:1
-
Tidskriftsartikel (refereegranskat)abstract
- We describe a new and model-independent Lévy imaging method of quality fits to the published datasets and reconstruct the amplitude of high-energy pp and pp¯ elastic scattering processes. This method allows us to determine the excitation function of the shadow profile P(b), the elastic slope B(t) and the nuclear phase ϕ(t) functions of pp and pp¯ collisions directly from the data. Surprisingly, notable qualitative differences in B(t) for pp and for pp¯ collisions point towards an Odderon effect. As a by-product, we clearly identify the proton substructure with two different sizes at the ISR and LHC energies, that has striking similarity to a dressed quark (at the ISR) and a dressed diquark (at the LHC). We present model-independent results for the corresponding sizes and cross-sections for such a substructure for the existing data at different energies.
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| 16. |
- Csörgő, T., et al.
(författare)
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Proton structure and hollowness from Lévy imaging of pp elastic scattering
- 2020
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 80:2
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Tidskriftsartikel (refereegranskat)abstract
- The recently developed Lévy imaging method enables to extract an important physics information on hadron structure at high energies and ultra-low momentum transfers directly from elastic scattering data. In this work, we employ such a model-independent method to probe the internal structure of the proton and quantify its inelasticity profile in the impact parameter space emerging in proton-proton collisions at the highest available energy of s=13 TeV. The inelasticity profile function and its error band for the proton and its substructure have been reconstructed at different energies and the proton hollowness (or “black-ring”) effect with beyond 5σ significance has been found at 13 TeV.
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| 17. |
- Csörgő, T., et al.
(författare)
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Scaling of high-energy elastic scattering and the observation of odderon
- 2021
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Ingår i: Gribov-90 Memorial Volume : Field Theory, Symmetry, And Related Topics - Proceedings Of The Memorial Workshop Devoted To The 90th Birthday Of V N Gribov - Field Theory, Symmetry, And Related Topics - Proceedings Of The Memorial Workshop Devoted To The 90th Birthday Of V N Gribov. - : WORLD SCIENTIFIC. - 9789811238406 ; , s. 69-80
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Bokkapitel (refereegranskat)abstract
- We provide a statistically significant observation of the elusive Odderon exchange, based on novel and model-independent analysis of the scaling properties of the differential cross sections of elastic pp and pp scattering in the TeV energy range. We report the statistical significance of the observed Odderon signal at the level of 6.26 σ.
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| 18. |
- Freitas, Felipe F., et al.
(författare)
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Ultralight bosons for strong gravity applications from simple Standard Model extensions
- 2021
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; 2021:12
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Tidskriftsartikel (refereegranskat)abstract
- We construct families, and concrete examples, of simple extensions of the Standard Model that can yield ultralight real or complex vectors or scalars with potential astrophysical relevance. Specifically, the mass range for these putative fundamental bosons (∼ 10-10-10-20 eV) would lead dynamically to both new non-black hole compact objects (bosonic stars) and new non-Kerr black holes, with masses of ∼ Mo˙ to ∼ 1010 Mo˙, corresponding to the mass range of astrophysical black hole candidates (from stellar mass to supermassive). For each model, we study the properties of the mass spectrum and interactions after spontaneous symmetry breaking, discuss its theoretical viability and caveats, as well as some of its potential and most relevant phenomenological implications linking them to the physics of compact objects.
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| 19. |
- Krelina, M., et al.
(författare)
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Nuclear effects in Drell-Yan production at the LHC
- 2016
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X. ; 120
-
Konferensbidrag (refereegranskat)abstract
- Using the color dipole formalism we study production of Drell-Yan (DY) pairs in proton-nucleus interactions in the kinematic region corresponding to LHC experiments. Lepton pairs produced in a hard scattering are not accompanied with any final state interactions leading to either energy loss or absorption. Consequently, dileptons may serve as more efficient and cleaner probes for the onset of nuclear effects than nclusive hadron production. We perform a systematic analysis of these effects in production of Drell-Yan pairs in pPb interaction at the LHC. We present predictions for the nuclear suppression as a function of the dilepton transverse momentum, rapidity and invariant mass which can be verified by the LHC measurements. We found that a strong nuclear suppression can be interpreted as an effective energy loss proportional to the initial energy universally induced by multiple initial state interactions. In addition, we study a contribution of coherent effects associated with the gluon shadowing affecting the observables predominantly at small and medium-high transverse momenta.
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| 20. |
- Krelina, M., et al.
(författare)
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Systematic study of real photon and Drell-Yan pair production in p+A (d+A) interactions
- 2016
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X. ; 120
-
Konferensbidrag (refereegranskat)abstract
- We study nuclear effects in production of Drell-Yan pairs and direct photons in proton-nucleus collisions. For the first time, these effects are studied within the color dipole approach using the Green function formalism which naturally incorporates the color transparency and quantum coherence effects. The corresponding numerical results for the nuclear modification factor are compared with available data. Besides, we present a variety of predictions for the nuclear suppression as a function of transverse momentum pT, Feynman variable xF and invariant mass M of the lepton pair which can be verified by experiments at RHIC and LHC. We found that the nuclear suppression is caused predominantly by effects of quantum coherence (shadowing corrections) and by the effective energy loss induced by multiple initial state interactions. Whereas the former dominate at small Bjorken x2 in the target, the latter turns out to be significant at large x1 in the projectile beam and is universal at different energies and transverse momenta.
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| 21. |
- Krelina, M., et al.
(författare)
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The onset of spin rotation effects in electroproduction of heavy quarkonia
- 2019
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Ingår i: European Physical Society Conference on High Energy Physics (EPS-HEP2019). - Trieste, Italy : Sissa Medialab. - 1824-8039. ; 364
-
Konferensbidrag (refereegranskat)abstract
- We discuss the Melosh spin rotation effects in diffractive photo- and electroproduction of heavy quarkonia off a nucleon target in the dipole picture. The quarkonium light-front wave functions are obtained in the Schroedinger equation based formalism using the realistic interquark interaction potentials. A strong onset of spin rotation effects predicted in the case of J/ψ(1S) photoproduction enables us to reach a reasonable agreement with the available data. In the case of radially excited 2S and 3S states these effects are even stronger as a direct manifestation of the nodal structure of their wave functions. In particular, the spin effects enhance the Ψ0(2S) cross section by a factor of 2 − 3 and therefore cause a substantial increase of the Ψ0(2S)-to-J/Ψ(1S) ratio improving the description of experimental data.
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| 22. |
- Kuksa, V., et al.
(författare)
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Factorization effect and near-threshold boson production at linear colliders
- 2010
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Ingår i: Proceedings of Science.
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Konferensbidrag (refereegranskat)abstract
- We calculate cross-section of the near-threshold three-boson production at the ILC with an account of their instability and a principal part of NLO corrections. The calculations are fulfilled within the framework of the model of unstable particles with smeared mass. We show that the contribution of finite width (instability) is large in the resonance Higgs-mass range and should be taken into account. Suggested approach significantly simplifies calculations with respect to traditional one.
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| 23. |
- Lebiedowicz, P., et al.
(författare)
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Measurement of exclusive production of scalar chi(c0) meson in proton-(anti)proton collisions via chi(c0) -> pi(+)pi(-) decay
- 2011
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 701:4, s. 434-444
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Tidskriftsartikel (refereegranskat)abstract
- We consider a measurement of exclusive production of scalar chi(c)(0(++)) meson in the proton-proton collisions at LHC and RHIC and in the proton-antiproton collisions at the Tevatron via chi(c0) -> pi(+)pi(-) decay. The corresponding amplitude for exclusive double-diffractive chi(c0) meson production was obtained within the k(t)-factorization approach including virtualities of active gluons and the corresponding cross section is calculated with unintegrated gluon distribution functions (UGDFs) known from the literature. The four-body pp -> pp pi(+)pi(-) reaction constitutes an irreducible background to the exclusive chi(c0) meson production. We include absorption effects due to proton-proton interaction and pion-pion rescattering. We calculate several differential distributions for pp((p) over bar) -> pp((p) over bar)chi(c0) process including the absorptive corrections. The influence of kinematical cuts on the signal-to-background ratio is investigated. Corresponding experimental consequences are discussed.
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| 24. |
- Maciula, R., et al.
(författare)
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Exclusive double-diffractive production of open charm in proton-proton and proton-antiproton collisions
- 2010
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 685:2-3, s. 165-169
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Tidskriftsartikel (refereegranskat)abstract
- We calculate differential cross sections for exclusive double diffractive (EDD) production of open charm in proton-proton and proton-antiproton collisions. Sizeable cross sections are found. The EDD contribution Constitutes about 1% of the total inclusive cross section for open charm production. A few differential distributions are shown and discussed. The EDD contribution falls faster both with transverse momentum of the c quark/antiquark and the c (c) over bar invariant mass than in the inclusive case.
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| 25. |
- Prokhorov, L. G., et al.
(författare)
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Wave fluctuations in the system with some Yang-Mills condensates
- 2016
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Ingår i: Physics of Atomic Nuclei. - 1063-7788. ; 79:11-12, s. 1502-1504
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Tidskriftsartikel (refereegranskat)abstract
- Self-consistent dynamics of non-homogeneous fluctuations and homogeneous and isotropic condensate of Yang–Mills fields was investigated in zero, linear and quasilinear approximations over the wave modes in the framework of N = 4 supersymmetric model in Hamilton gauge in quasiclassical theory. The models with SU(2), SU(3) and SU(4) gauge groups were considered. Particle production effect and effect of generation of longitudinal oscillations were obtained.
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