Impact parameter dependence of parton densities at low x

We consider impact parameter dependence of the polarized and unpolarized parton densities. Unitarity does not allow factorization of these structure functions over the Bjorken x and the impact parameter b variables. On the basis of the particular geometrical model approach we conclude that spin of constituent quark may have a significant orbital angular momentum component which can manifest itself through the peripherality of the spin dependent structure functions.Comment: 4 pages, to appear in the Proceedings of the Workshop Diffraction 2000, Cetraro, Italy, 2-7 September 200

The role of double helicity-flip amplitudes in small-angle elastic pp-scattering

We asses a role of the double helicity-flip amplitudes in small-angle elastic pp-scattering and obtain a new unitary bound for the double helicity-flip amplitude F_2 in elastic pp-scattering at small values of t on the basis of the U-matrix method of the s-channel unitarization.Comment: 8 pages, minor correction

Strangeness in constituent quarks and one-spin asymmetry in inclusive φ\varphi-meson production

On the basis of the mechanism proposed earlier for one-spin asymmetries in inclusive hadron production we consider OZI--suppressed process of $\varphi$-meson production $pp\rightarrow \varphi X$ and asymmetry $A_N(\varphi)$ in this process. The main role in generation of this asymmetry belongs to the orbital angular momentum of strange quark-antiquark cloud in internal structure of constituent quarks.Comment: 8 pages, plain LaTeX, no figure

Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale

Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV

Searches for supersymmetry (SUSY) are presented based on the electroweak pair production of neutralinos and charginos, leading to decay channels with Higgs, Z, and W bosons and undetected lightest SUSY particles (LSPs). The data sample corresponds to an integrated luminosity of about 19.5 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV collected in 2012 with the CMS detector at the LHC. The main emphasis is neutralino pair production in which each neutralino decays either to a Higgs boson (h) and an LSP or to a Z boson and an LSP, leading to hh, hZ, and ZZ states with missing transverse energy (E-T(miss)). A second aspect is chargino-neutralino pair production, leading to hW states with E-T(miss). The decays of a Higgs boson to a bottom-quark pair, to a photon pair, and to final states with leptons are considered in conjunction with hadronic and leptonic decay modes of the Z and W bosons. No evidence is found for supersymmetric particles, and 95% confidence level upper limits are evaluated for the respective pair production cross sections and for neutralino and chargino mass values

SPIN EFFECTS IN HADRON SCATTERING AT LARGE ANGLES AND QUARK INTERACTION DYNAMICS

Le comportement des paramètres Ann (S, 90) et P(s, θ) pour la diffusion pp et ΠN dans le domaine des grands angles est considéré d'après la conception basée sur la résolution de l'équation dynamique pour l'amplitude de la diffusion dans la théorie quantique des champs. Les paramètres Ann et Aℓℓ peuvent osciller avec le changement de s. Leur valeurs asymptotiques sont de 1/3 et de -1/3 respectivement. Ce comportement permet d'expliquer les valeurs expérimentales obtenues au ZGS. La polarisation P(s, θ) dans le domaine des grands angles de la diffusion peut avoir une valeur considérable et ne pas diminuer avec l'augmentation de s. Les relations entre s-dépendance de P(s, θ), Ann (s, 90°) et la section différentielle sont discutées.)Spin correlation parameter Ann (s, 90°) and polarization parameter P(s, θ) behaviour in the large angle pp- and ΠN-scattering is considered in the approach, based on the three-dimensional equation for the scattering amplitude in QFT. Parameters Ann and Aℓℓ may have oscillating behaviour with s, and their asymptotic values are 1/3 and -1/3, respectively. This allows one to explain ZGS spin effects. Polarisation P(s, θ) in large angle scattering may get a considerable value and does not decrease with s. Relations between s-dependencies of P(s, θ), Ann (s, 90o) and dσ/dt (s, 90°) are discussed

Beyond the black disk limit

We consider consequences of violation of the black disk limit possibly revealed by the new CDF measurements of the total, elastic and diffractive cross--sections.Comment: Latex, 5 pages, no figures, IHEP 93-5