arXiv subjects

R. Pasechnik

Publications and source records attributed to R. Pasechnik.

22 records · Page 2Linked to original sources

arXiv2019

Convergence properties of Lévy expansions: implications for Odderon and proton structure

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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arXiv2019

Lévy imaging of elastic hadron-hadron scattering: Odderon and inner structure of the proton

A novel model-independent Lévy imaging method is employed for reconstruction of the elastic $pp$ and $p\bar p$ 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 LHC energies. We found qualitative differences in properties of $B(t)$ and $ϕ(t)$ between $pp$ and for $p\bar p$ 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 of a dressed diquark at the LHC energies, respectively.

hep-ph↗

arXiv2019

Diffractive dijet production: breakdown of factorization

We analyse the origin of dramatic breakdown of diffractive factorisation, observed in single-diffractive (SD) dijet production in hadronic collisions. One of the sources is the application of the results of measurements of the diagonal diffractive DIS to the off-diagonal hadronic diffractive process. The suppression caused by a possibility of inelastic interaction with the spectator partons is calculated at the amplitude level, differently from the usual probabilistic description. It turns out, however, that interaction with the spectator partons not only suppresses the SD cross section, but also gives rise to the main mechanism of SD dijet production, which is another important source of factorization failure. Our parameter-free calculations of SD-to-inclusive cross section ratio, performed in the dipole representation, agrees with the corresponding CDF Tevatron (Run II) data at $\sqrt{s}=1.96$ TeV in the relevant kinematic regions. The energy and hard scale dependences demonstrate a trend, opposite to the factorisation-based expectations, similarly to the effect observed earlier in diffractive Abelian radiation.

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arXiv2011

Enhancement of associated H^\pm W^\mp production in the NMSSM

We study the associated production of a charged Higgs and a W boson in high-energy pp collisions at the Large Hadron Collider. This is an interesting process for charged Higgs discovery, or exclusion, since the production cross section could depend strongly on the model, offering potential discriminating power between supersymmetric extensions of the Standard Model with minimal or extended Higgs sectors. We compute the cross section for this process in the next-to-minimal supersymmetric Standard Model (NMSSM), at the tree level for quark-quark scattering and at one-loop level for gluon-gluon scattering. The most important corrections beyond leading order are taken into account using an improved Born approximation. We find that the pp \to H^\pm W^\mp cross section can be resonantly enhanced by up to an order of magnitude over its MSSM value (both for \sqrt{s}=7 TeV and 14 TeV) through the contributions of heavy, neutral, singlet-dominated Higgs bosons appearing in the s-channel. Since such Higgs mass configurations are normally not possible in the MSSM, the observation of associated H^\pm W^\mp production at the LHC could provide a striking, although indirect, signature of a more complicated Higgs sector.

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