| 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. |
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| 3. |
- 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
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Ingår i: Investigating the dominant regions of the phase space associated with cc production relevant for the prompt atmospheric neutrino flux. - 1824-8039. ; 316
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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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| 4. |
- 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
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Ingår i: Physical Review D. - 2470-0010. ; 96:9
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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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| 5. |
- 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
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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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| 6. |
- 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
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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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| 7. |
- 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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| 8. |
- 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
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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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