| 1. |
- Anchordoqui, Luis A., et al.
(författare)
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The Forward Physics Facility : Sites, experiments, and physics potential
- 2022
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Ingår i: Physics reports. - : Elsevier. - 0370-1573 .- 1873-6270. ; 968, s. 1-50
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Tidskriftsartikel (refereegranskat)abstract
- The Forward Physics Facility (FPF) is a proposal to create a cavern with the space and infrastructure to support a suite of far-forward experiments at the Large Hadron Collider during the High Luminosity era. Located along the beam collision axis and shielded from the interaction point by at least 100 m of concrete and rock, the FPF will house experiments that will detect particles outside the acceptance of the existing large LHC experiments and will observe rare and exotic processes in an extremely low-background environment. In this work, we summarize the current status of plans for the FPF, including recent progress in civil engineering in identifying promising sites for the FPF and the experiments currently envisioned to realize the FPF's physics potential. We then review the many Standard Model and new physics topics that will be advanced by the FPF, including searches for long-lived particles, probes of dark matter and dark sectors, high-statistics studies of TeV neutrinos of all three flavors, aspects of perturbative and non-perturbative QCD, and high-energy astroparticle physics.
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| 2. |
- Babiarz, Izabela, et al.
(författare)
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Central exclusive production of scalar and pseudoscalar charmonia in the light-front kT -factorization approach
- 2020
-
Ingår i: Physical Review D. - 2470-0010. ; 102:11
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Tidskriftsartikel (refereegranskat)abstract
- We study exclusive production of scalar χc0χc(0++) and pseudoscalar ηc charmonia states in proton-proton collisions at the LHC energies. The amplitudes for gg→χc0 as well as for gg→ηc mechanisms are derived in the kT-factorization approach. The pp→ppηc reaction is discussed for the first time. We have calculated rapidity, transverse momentum distributions, and such correlation observables as the distribution in relative azimuthal angle and (t1,t2) distributions. The latter two observables are very different for χc0 and ηc cases. In contrast to the inclusive production of these mesons considered very recently in the literature, in the exclusive case, the cross section for ηc is much lower than that for χc0, which is due to a special interplay of the corresponding vertices and off-diagonal unintegrated gluon distributions used to calculate the cross sections. We present the numerical results for the key observables in the framework of potential models for the light-front quarkonia wave functions. We also discuss how different the absorptive corrections are for both considered cases.
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| 3. |
- Babiarz, Izabela, et al.
(författare)
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Hadroproduction of scalar P -wave quarkonia in the light-front kT -factorization approach
- 2020
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Ingår i: Journal of High Energy Physics. - 1126-6708. ; 2020:6
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we present a thorough analysis of scalar P -wave χQ0, Q = c, b quarkonia electromagnetic form factors for the γ∗γ∗→ χQ0 couplings, as well as their hadroproduction observables in k⊥-factorisation using the light-front (LF) potential approach for the quarkonium wave function. The electromagnetic form factors are presented as functions of photon virtualities. We discuss the role of the Melosh spin-rotation and relativistic corrections estimated by comparing our results with those in the standard nonrelativistic QCD (NRQCD) approach. Theoretical uncertainties of our approach are found by performing the analysis with two different unintegrated gluon densities and with five distinct models of the QQ¯ interaction potentials consistent with the meson spectra. The results for the rapidity and transverse momentum distributions of χQ0 produced in high-energy pp collisions at s = 13 TeV are shown.
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| 4. |
- Babiarz, Izabela, et al.
(författare)
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Light-front approach to axial-vector quarkonium γ * γ * form factors
- 2022
-
Ingår i: Journal of High Energy Physics. - 1029-8479. ; 2022:9
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we perform a detailed study of transition form factors for axial- vector meson production via the two-photon fusion process γ*γ* → 1++, with space-like virtual photons in the initial state and a P-wave axial-vector quarkonium in the final state. In this analysis, we employ the formalism of light-front quarkonium wave functions obtained from a solution of the Schrödinger equation for a selection of interquark potentials for QQ¯ interaction. We found the helicity structure and covariant decomposition of the matrix elements that can be generically applied for any qq¯ axial-vector meson γ*γ* → 1++ transition, while our numerical results are given for the phenomenologically relevant charmonium χc1 state. We present the helicity form factors as functions of both photon virtualities. We also obtain, that QFLT(Q2, 0)/FTT(Q2, 0) = const.
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| 5. |
- Babiarz, Izabela, et al.
(författare)
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Probing the structure of χc1 (3872) with photon transition form factors
- 2023
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Ingår i: Physical Review D. - 2470-0010. ; 107:7
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Tidskriftsartikel (refereegranskat)abstract
- We propose studying the structure of the χc1(3872) axial vector meson through its γL∗γ→χc1(3872) transition form factor. We derive a light-front wave function representation of the form factor for the lowest cc¯ Fock state. We found that the reduced width of the state is well within the current experimental bound recently published by the Belle Collaboration. This strongly suggests a crucial role of the cc¯ Fock-state in the photon-induced production. Our results for the Q2 dependence can be tested by future single-tagged e+e- experiments, giving further insight into the short-distance structure of this meson.
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| 6. |
- Babiarz, Izabela, et al.
(författare)
-
Prompt hadroproduction of ηc(1S, 2S) in the kT-factorization approach
- 2020
-
Ingår i: Journal of High Energy Physics. - 1029-8479. ; 2020:2
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we present a thorough analysis of ηc(1S, 2S) quarkonia hadroproduction in k⊥-factorisation in the framework of the light-front potential approach for the quarkonium wave function. The off-shell matrix elements for the g*g*ηc(1S, 2S) vertices are derived. We discuss the importance of taking into account the gluon virtualities. We present the transverse momentum distributions of ηc for several models of the unintegrated gluon distributions. Our calculations are performed for four distinct parameterisations for the cc¯ interaction potential consistent with the meson spectra. We compare our results for ηc(1S) to measurements by the LHCb collaboration and present predictions for ηc(2S) production.
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| 7. |
- Babiarz, Izabela, et al.
(författare)
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The γ∗γ∗→ ηc (1S; 2S) transition form factor from quarkonium wave functions
- 2019
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Ingår i: PHOTON 2019 - International Conference on the Structure and the Interactions of the Photon. - 1122-5157. - 9788886409704 ; 69, s. 95-100
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Konferensbidrag (refereegranskat)abstract
- We discuss γ ∗γ ∗→ ηc(1S) ; ηc (2S) transition form factor for both virtual photons. The general formula is given. We use difierent models for the cc̄ wave function obtained from the solution of the Schrödinger equation for diffierent cc̄ potentials: harmonic oscillator, Cornell, logarithmic, power-law, Coulomb and Buchmüller{Tye. We showed some examples of wave functions in the Light Front representation as well as in the rest frame of cc̄. We compare our results to the BaBar experimental data for ηc(1S), with one real and one virtual photon, and to the values collected by the Particle Data Group for the form factor F(0; 0), decay width τγ γ and decay constant fηc . We also consider the non-relativistic limit for F(0; 0) with the wave function evaluated at the origin R(0).
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| 8. |
- Babiarz, Izabela, et al.
(författare)
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The γ∗γ∗ → ηc(1S,2S) transition form factors for two spacelike photons
- 2019
-
Ingår i: European Physical Society Conference on High Energy Physics (EPS-HEP2019). - Trieste, Italy : Sissa Medialab. - 1824-8039. ; 364
-
Konferensbidrag (refereegranskat)abstract
- We discuss γ∗γ∗ → ηc(1S), ηc(2S) transition form factors for both virtual photons. The general formula is given. We use different models for the cc¯ wave function obtained from the solution of the Schrödinger equation for different cc¯ potentials: harmonic oscillator, Cornell, logarithmic, power-law, Coulomb and Buchmüller-Tye. We showed some examples of wave functions in the Light Front representation as well as in the rest frame of cc¯ pair. We compare our results to the BaBar experimental data for ηc(1S), for one real and one virtual photon, and to the values collected by the Particle Data Group for F(0,0), decay width Γγγ and decay constant fηc. We also considered the non-relativistic limit for F(0,0) form factor with the wave function at the origin R(0).
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| 9. |
- Babiarz, Izabela, et al.
(författare)
-
γ∗γ∗ →ηc (1S,2S) transition form factors for spacelike photons
- 2019
-
Ingår i: Physical Review D. - 2470-0010. ; 100:5
-
Tidskriftsartikel (refereegranskat)abstract
- We derive the light-front wave function (LFWF) representation of the γ∗γ∗→ηc(1S),ηc(2S) transition form factor F(Q12,Q22) for two virtual photons in the initial state. For the LFWF, we use different models obtained from the solution of the Schrödinger equation for a variety of cc̄ potentials. We compare our results to the BABAR experimental data for the ηc(1S) transition form factor, for one real and one virtual photon. We observe that the onset of the asymptotic behavior is strongly delayed and discuss applicability of the collinear and/or massless limit. We present some examples of two-dimensional distributions for F(Q12,Q22). A factorization breaking measure is proposed and factorization breaking effects are quantified and shown to be almost model independent. Factorization is shown to be strongly broken, and a scaling of the form factor as a function of Q̄2=(Q12+Q22)/2 is obtained.
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| 10. |
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| 11. |
- Goncalves, Victor P., et al.
(författare)
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Investigating the dominant regions of the phase space associated with cc production relevant for the prompt atmospheric neutrino flux
- 2018
-
Ingår i: Investigating the dominant regions of the phase space associated with cc production relevant for the prompt atmospheric neutrino flux. - 1824-8039. ; 316
-
Konferensbidrag (refereegranskat)abstract
- A detailed mapping of the dominant kinematical domains contributing to the prompt atmospheric neutrino flux at high neutrino energies is presented by studying their sensitivity to the cuts on several kinematical variables crucial for charm production in cosmic ray scattering in the atmosphere. This includes the maximal center-of-mass energy for proton-proton scattering, the longitudinal momentum fractions of partons in the projectile (cosmic ray) and target (nucleus of the atmosphere), and the Feynman xF variable. We find that the production of neutrinos with energies larger than Eν > 107 GeV is particularly sensitive to the cm. energies larger than the ones at the LHC and to the longitudinal momentum fractions in the projectile 108 < × < 105. Our results indicate that the precision data on the prompt atmospheric neutrino flux can efficiently constrain the mechanism of heavy quark production and underlying QCD dynamics in kinematical ranges beyond the reach of the current collider measurements.
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| 12. |
- Goncalves, Victor P., et al.
(författare)
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Mapping the dominant regions of the phase space associated with c c - production relevant for the prompt atmospheric neutrino flux
- 2017
-
Ingår i: Physical Review D. - 2470-0010. ; 96:9
-
Tidskriftsartikel (refereegranskat)abstract
- We present a detailed mapping of the dominant kinematical domains contributing to the prompt atmospheric neutrino flux at high neutrino energies by studying their sensitivity to the cuts on several kinematical variables crucial for charm production in cosmic ray scattering in the atmosphere. This includes the maximal center-of-mass energy for proton-proton scattering, the longitudinal momentum fractions of partons in the projectile (cosmic ray) and target (nucleus of the atmosphere), the Feynman xF variable, and the transverse momentum of charm quark/antiquark. We find that the production of neutrinos with energies larger than Eν>107 GeV is particularly sensitive to the c.m. energies larger than the ones at the LHC and to the longitudinal momentum fractions in the projectile 10-8
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| 13. |
- Lebiedowicz, Piotr, et al.
(författare)
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Can the diphoton enhancement at 750 GeV be due to a neutral technipion?
- 2016
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Ingår i: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-7998. ; 94:1
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Tidskriftsartikel (refereegranskat)abstract
- We discuss a scenario in which the diphoton enhancement at Mγγ=750 GeV, observed by the ATLAS and CMS collaborations, is a neutral technipion π0. We consider two distinct minimal models for the dynamical electroweak symmetry breaking. In a first one, two-flavor vectorlike technicolor (VTC) model, we assume that the two-photon fusion is a dominant production mechanism. We include γγ→π0 and production of technipion associated with one or two jets. All the considered mechanisms give similar contributions. With the strong Yukawa (technipion-techniquark) coupling gTC≃20 we roughly obtain the measured cross section of the "signal" with a small difficulty of simultaneous description of the s=13 TeV and s=8 TeV data. With such values of gTC we get a relatively small Γtot. In a second approach, one-family walking technicolor (WTC) model, the isoscalar technipion is produced dominantly via the gluon-gluon fusion. We also discuss the size of the signal at lower energies (LHC, Tevatron) for γγ (VTC) and jet-jet (WTC) final states and check consistency with the existing experimental data. We predict a measurable cross section for πO production associated with one or two soft jets. The technipion signal in both models is compared with the SM background diphoton contributions. We observe the dominance of the inelastic-inelastic mechanism for γγ induced processes. In the VTC scenario, we predict the signal cross section for purely exclusive pp→ppγγ processes at s=13 TeV to be about 0.2 fb. Such a cross section would be, however, difficult to measure with the planned integrated luminosity. In all considered cases the signal is below the background or/and below the threshold set by statistics.
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| 14. |
- Lebiedowicz, Piotr, et al.
(författare)
-
Diffractive pQCD mechanism of exclusive production of W+W - pairs in proton-proton collisions
- 2012
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Ingår i: Proceedings of Science.
-
Konferensbidrag (refereegranskat)abstract
- We present a study of central exclusive production of W+W - pairs in proton-proton collisions at the LHC. We compare the contribution of the γγ → W+W- mechanism with a new mechanism of exclusive diffractive production through the gg → W+W- subprocess with intermediate virtual Higgs boson and quark box diagrams. The amplitude for the latter process is expressed in terms of the off-diagonal unintegrated gluon distribution functions. Several observables related to this process are calculated. The phase space integrated diffractive contribution when separated is only a small fraction of fb compared to 115.4 fb of the γγ-contribution without absorption. This opens a possibility of efficient searches for anomalous boson γW+W - and γγW+W- couplings due to new physics beyond Standard Model.
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| 15. |
- Lebiedowicz, Piotr, et al.
(författare)
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Interpreting the 750 GeV diphoton signal as technipion
- 2016
-
Ingår i: Proceedings of Science. - 1824-8039. ; 11-15-April-2016
-
Tidskriftsartikel (refereegranskat)abstract
- We discuss whether the enhancement in the diphoton final state at Mgg = 750 GeV, observed recently by the ATLAS and CMS Collaborations could be a neutral pseudoscalar technipion π∼0. We considered two distinct minimal models for the dynamical electroweak symmetry breaking. Here we concentrate only on two-flavor vector-like technicolor model and we assume that the two-photon fusion is a dominant production mechanism. We include contributions of 2 → 1, 2→2 and 2→3 partonic processes. All the mechanisms give similar contributions to the cross section. With the strong Yukawa (technipion-techniquark) coupling gTC ≃ 20 we roughly obtain the measured cross section of the "signal". With such value of gTC we get a relatively small total decay width Gtot. We discuss also the size of the signal at lower energies (LHC, Tevatron) for γ γ final states, where the enhancement was not observed. We predict a measurable cross section for neutral technipion production associated with one or two soft jets. The technipion signal is compared with the Standard Model diphoton background contributions. We observe the dominance of inelastic-inelastic γ γ processes. We predict the signal cross section for purely exclusive pp→ ppγ γ procesess at √s = 13 TeV to be about 0.2 fb. Such a cross section would be, however, difficult to measure with the planned integrated luminosity. We conclude that in all considered cases the signal is below the background or/and statistics is not sufficient to observe it.
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| 16. |
- Lebiedowicz, Piotr, et al.
(författare)
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QCD diffractive mechanism of exclusive W+W- pair production at high energies
- 2013
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Ingår i: Nuclear Physics, Section B. - : Elsevier BV. - 0550-3213. ; 867:1, s. 61-81
-
Tidskriftsartikel (refereegranskat)abstract
- We discuss new diffractive mechanism of central exclusive production of W+W- pairs in proton-proton collisions at the LHC. We include diagrams with intermediate virtual Higgs boson as well as quark box diagrams. Several observables related to this process are calculated. Predictions for the total cross section and differential distributions in W-boson rapidity and transverse momentum as well as WW invariant mass are presented. We also show results for different polarization states of the final W-+/- bosons. We compare the contribution of the gamma gamma -> W+W- mechanism considered in the literature with the contribution of the diffractive mechanism through the gg -> W(+)W(-)subprocess for the different observables. The phase space integrated diffractive contribution when separated is only a small fraction of fb compared to 115.4 fb of the gamma gamma-contribution without absorption. The latter contribution dominates at small four-momentum transfers squared in the proton lines and in a broad range of W+W- invariant masses. This offers a possibility of efficient searches for anomalous triple-boson (gamma WW) and quartic-boson (gamma gamma WW) couplings and testing models beyond the Standard Model. We discuss shortly also the pp -> pp gamma gamma process, where the box contribution is very similar to that for W+W- and compare our results with recent CDF data. Nice agreement has been achieved without additional free parameters. (C) 2012 Elsevier B.V. All rights reserved.
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| 17. |
- Lebiedowicz, Piotr, et al.
(författare)
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Search for technipions in exclusive production of diphotons with large invariant masses at the LHC
- 2014
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Ingår i: Nuclear Physics, Section B. - : Elsevier BV. - 0550-3213. ; 881, s. 288-308
-
Tidskriftsartikel (refereegranskat)abstract
- We focus on exclusive production of neutral technipion (pi) over tilde (0) in pp collisions at the LHC, i.e. on pp -> pp (pi) over tilde (0) reaction. The dependence of the cross section on parameters of recently proposed vector-like Technicolor model is studied. Characteristic features of the differential distributions are discussed. For not too large technipion masses the diphoton decay channel has the dominant branching fraction. This is also the main reason for an enhanced production of neutral technipions in gamma gamma-fusion reaction. We discuss potential backgrounds of the QCD and QED origin to the pp -> pp ((pi) over tilde (0) -> gamma gamma) process at large invariant gamma gamma masses. We conclude that compared to inclusive case the signal-to-background ratio in the considered exclusive reaction is very favorable which thereby could serve as a good probe for Technicolor dynamics searches at the LHC. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/).
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| 18. |
- Linek, Barbara, et al.
(författare)
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Probing proton structure with c c ¯ correlations in ultraperipheral pA collisions
- 2023
-
Ingår i: Journal of High Energy Physics. - 1029-8479. ; 2023:10
-
Tidskriftsartikel (refereegranskat)abstract
- We study the exclusive diffractive cc¯ photoproduction in ultraperipheral pA collisions. The formalism makes use of off-diagonal generalizations of the unintegrated gluon distribution, the so-called generalized transverse momentum dependent distributions (GTMDs). We present two different formulations. The first one is based directly on gluon GTMD parametrizations in momentum space. Another option is the calculation of the GTMD as a Fourier transform of the dipole-nucleon scattering amplitude N(Y, r→ ⊥, b→ ⊥). The latter approach requires some extra regularization discussed in the paper. Different dipole amplitudes from the literature are used. Compared to previous calculations in the literature, we integrate over the full phase space and therefore cross sections for realistic conditions are obtained. We present distributions in rapidity of c or c¯ , transverse momentum of the cc¯ pair, four-momentum transfer squared as well as the azimuthal correlation between a sum and a difference of the c and c¯ transverse momenta. The azimuthal correlations are partially due to the so-called elliptic gluon Wigner distribution. Different models lead to different modulations in the azimuthal angle. The modulations are generally smaller than 5%. They depend on the range of transverse momentum selected for the calculation.
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| 19. |
- Maciula, Rafal, et al.
(författare)
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Central exclusive quark-antiquark dijet and standard model Higgs boson production in proton-(anti)proton collisions
- 2011
-
Ingår i: Physical Review D. Particles and fields. - 0556-2821 .- 1089-4918. ; 83:11
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Tidskriftsartikel (refereegranskat)abstract
- We consider the central exclusive production of q (q) over bar pairs and Higgs boson in proton-proton collisions at LHC. The amplitude for the process is derived within the k(perpendicular to)-factorization approach and considered in different kinematical asymptotics, in particular, in the important high quark transverse momenta and massless quark limits. Quark helicity and spin-projection amplitudes in two different frames are shown in extenso. Rapidity distributions, quark jet p(perpendicular to) distributions, invariant q (q) over bar mass distributions, angular azimuthal correlations between outgoing protons and jets are presented. Irreducible b (b) over bar background to the central exclusive Higgs boson production is analyzed in detail, in particular, how to impose cuts to maximize signal-to-background ratio.
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| 20. |
- Maciula, Rafal, et al.
(författare)
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Exclusive b(b)over-bar pair production and irreducible background to the exclusive Higgs boson production
- 2010
-
Ingår i: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998. ; 82:11, s. 114011-
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Tidskriftsartikel (refereegranskat)abstract
- We calculated the cross section for the exclusive double-diffractive b (b) over bar production in pp -> p(b (b) over bar )p reaction at LHC. Large cross sections are obtained (3-10 nb). This process constitutes the irreducible background to the exclusive Higgs production and is of particular importance in the upcoming Higgs boson searches. The distribution in invariant mass of the b (b) over bar pair is calculated and compared with the corresponding contribution from the Higgs decay. The contribution from the exclusive production of Z(0) and its decay as well as the contribution from the gamma gamma -> b (b) over bar subprocess are also presented for the first time. The influence of cuts on the signal-to-background ratio is discussed.
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| 21. |
- Maciula, Rafal, et al.
(författare)
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New contributions to central exclusive production of dijets in proton-(anti)proton collisions
- 2011
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Ingår i: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 84:11
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Tidskriftsartikel (refereegranskat)abstract
- We consider central exclusive production of gg dijets in proton-proton (proton-antiproton) collisions at LHC and Tevatron for different intermediate and final gluon polarizations. The amplitude for the process is derived within the k(perpendicular to)-factorization approach (with both the standard QCD and the Lipatov's effective three-gluon vertices) and is considered in various kinematical asymptotia, in particular, in the important limit of high-p(perpendicular to) jets. Compared to earlier works we include emissions of gluons from different gluonic t-channel lines as well as emission of quark-antiquark dijets. Rapidity distributions, gluon jet p(perpendicular to) distributions and invariant dijet mass distributions are presented. We explore the competition of the standard diagram with both jets emitted from a single t-channel gluon and the one with the emission from both t-channel gluons. The second mechanism requires a special treatment. We propose two different approaches. Including special kinematics and using properties of off-diagonal gluons at small x and xi, we arrive to correlations in two-dimensional distributions in rapidity of one and second jet. We find that the second contribution is much smaller than that known from the literature. The digluon production constitutes an important background to exclusive Higgs production.
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| 22. |
- Maciuła, Rafał, et al.
(författare)
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Production of forward heavy-flavor dijets at the LHCb within the kT -factorization approach
- 2022
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Ingår i: Physical Review D. - 2470-0010. ; 106:5
-
Tidskriftsartikel (refereegranskat)abstract
- We calculate differential cross sections for cc¯- and bb¯-dijet production in pp scattering at s=13 TeV in the kT-factorization and hybrid approaches with different unintegrated parton distribution functions (uPDFs). We present distributions in the transverse momentum and pseudorapidity of the leading jet, the rapidity difference between the jets and the dijet invariant mass. Our results are compared to recent LHCb data on forward production of heavy-flavor dijets, measured recently for the first time individually for both charm and bottom flavors. We find that an agreement between the predictions and the data within the full kT factorization is strongly related to the modeling of the large-x behavior of the gluon uPDFs, which is usually not well constrained. The problem may be avoided following the hybrid-factorization approach. Then, we obtain a good description of the measured distributions with the parton-branching, Kimber-Martin-Ryskin, Kutak-Sapeta, and Jung setA0 models for the gluon uPDF. We also calculate differential distributions for the ratio of the cc¯ and bb¯ cross sections. In all cases we obtain a ratio close to 1, which is caused by the condition on the minimal jet transverse momentum (pTjet>20 GeV) introduced in the experiment, that makes the role of the heavy-quark mass almost negligible. The LHCb experimental ratio seems a bit larger than the theoretical predictions. We discuss potentially important for the ratio effect of c- or b-quark gluon radiative corrections related to emission outside of the jet cone. The found effect seems rather small. A more refined calculation requires full simulation of c and b jets, which goes beyond of the scope of this paper.
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| 23. |
- Pasechnik, Roman, et al.
(författare)
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Central exclusive production of polarised charmonia
- 2011
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Ingår i: Nuclear physics B, Proceedings supplements. - : Elsevier BV. - 0920-5632 .- 1873-3832. ; 214:1, s. 110-113
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Tidskriftsartikel (refereegranskat)abstract
- We consider exclusive double diffractive production of polarised axial-vector chi(c)(1(+)) and tensor chi(c)(2(+)) charmonia in proton-(anti)proton collisions at Tevatron energy. The corresponding amplitudes for these processes are derived within the k(t)-factorisation approach. Contributions from different polarisation states of axial-vector and tensor charmonia are quantified. Corresponding experimental consequences are discussed.
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| 24. |
- Pasechnik, Roman, et al.
(författare)
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Polarization effects in the central exclusive chi(c) production and the J/psi angular distributions
- 2011
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Ingår i: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998. ; 83:7, s. 074017-
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Tidskriftsartikel (refereegranskat)abstract
- We discuss exclusive elastic double diffractive axial-vector chi(c)(1(+)) and tensor chi(c)(2(+)) mesons production for different meson polarizations in proton-(anti)proton collisions at the Tevatron energy. The amplitude for the process is derived within the k(t)-factorization approach using unintegrated gluon distributions. Differential cross sections for different chi(c) polarizations are calculated. Angular distributions of J/psi meson from the radiative chi(c)(1(+),2(+)) decays are derived. Prospects for experimental selection of different spin states of chi(c) mesons are discussed.
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| 25. |
- Pasechnik, Roman, et al.
(författare)
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Spin effects in diffractive charmonia production
- 2011
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Ingår i: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 583-585
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Tidskriftsartikel (refereegranskat)abstract
- We consider exclusive double diffractive production of polarised axial-vector chi(c)(1(+)) and tensor chi(c)(2(+)) charmonia in proton-(anti)proton collisions at Tevatron energy. The corresponding amplitudes for these processes are derived within the k(t)-factorisation approach. Contributions from different polarisation states of axial-vector and tensor charmonia are quantified. Corresponding experimental consequences are discussed.
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| 26. |
- Szczurek, Antoni, et al.
(författare)
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Diffractive exclusive production of heavy quark pairs at high energy proton-proton collisions
- 2010
-
Ingår i: Proceedings of Science.
-
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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