Search results for "inelastic"
showing 10 items of 700 documents
Stimulated Raman-Spectroscopy of the Q-Branch of Nitrogen at High Pressure - Collisional Narrowing and Shifting in the 150-6800 Bar Range at Room Tem…
1992
0026-8976; The Raman Q branch of N2 has been recorded at room temperature in the pressure range 150-6800 bar, which corresponds to densities from 135 to 800 amagat. In this domain, the Raman Q branch profile is mainly determined by the well-known collisional narrowing. The experimental data have been obtained by means of a high resolution stimulated Raman spectrometer. The linewidth and line shift of the band have been accurately measured as functions of the density, and their density dependences have been fitted by polynomials. The minimum of the linewidth and the maximum of the red shift have been clearly observed at respectively 735.8 and 532.3 amagat. The lineshape was found to be Loren…
A glimpse of gluons through deeply virtual compton scattering on the proton
2017
The internal structure of nucleons (protons and neutrons) remains one of the greatest outstanding problems in modern nuclear physics. By scattering high-energy electrons off a proton we are able to resolve its fundamental constituents and probe their momenta and positions. Here we investigate the dynamics of quarks and gluons inside nucleons using deeply virtual Compton scattering (DVCS)—a highly virtual photon scatters off the proton, which subsequently radiates a photon. DVCS interferes with the Bethe-Heitler (BH) process, where the photon is emitted by the electron rather than the proton. We report herein the full determination of the BH-DVCS interference by exploiting the distinct energ…
Contribution of exclusive diffractive processes to the measured azimuthal asymmetries in SIDIS
2019
Hadron leptoproduction in Semi-Inclusive measurements of Deep-Inelastic Scattering (SIDIS) on unpolarised nucleons allows one to get information on the intrinsic transverse momentum of quarks in a nucleon and on the Boer-Mulders function through the measurement of azimuthal modulations in the cross section. These modulations were recently measured by the HERMES experiment at DESY on proton and deuteron targets, and by the COMPASS experiment using the CERN SPS muon beam and a $^6$LiD target. In both cases, the amplitudes of the $\cos\phi_h$ and $\cos 2\phi_h$ modulations show strong kinematic dependences for both positive and negative hadrons. It has been known since some time that the measu…
K− over K+ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy
2018
The K$^{-}$ over K$^{+}$ multiplicity ratio is measured in deep-inelastic scattering, for the first time for kaons carrying a large fraction $z$ of the virtual-photon energy. The data were obtained by the COMPASS collaboration using a 160 GeV muon beam and an isoscalar $^6$LiD target. The regime of deep-inelastic scattering is ensured by requiring $Q^2>1$ (GeV/$c)^2$ for the photon virtuality and $W>5$ GeV/$c^2$ for the invariant mass of the produced hadronic system. Kaons are identified in the momentum range from 12 GeV/$c$ to 40 GeV/$c$, thereby restricting the range in Bjorken-$x$ to $0.010.75$. For very large values of $z$, $i.e.$ $z>0.8$, we observe the kaon multiplicity ratio to fall …
Neutrino Structure Functions from GeV to EeV Energies
2023
The interpretation of present and future neutrino experiments requires accurate theoretical predictions for neutrino-nucleus scattering rates. Neutrino structure functions can be reliably evaluated in the deep-inelastic scattering regime within the perturbative QCD (pQCD) framework. At low momentum transfers ($Q^2 \le {\rm few}$ GeV$^2$), inelastic structure functions are however affected by large uncertainties which distort event rate predictions for neutrino energies $E_\nu$ up to the TeV scale. Here we present a determination of neutrino inelastic structure functions valid for the complete range of energies relevant for phenomenology, from the GeV region entering oscillation analyses to …
Gamma rays from cosmic-ray proton scattering in AGN jets: the intra-cluster gas vastly outshines dark matter
2013
Active Galactic Nuclei (AGN) host powerful jets containing high-energy electrons and protons. The astrophysical environment where AGNs and their jets are found is characterized by large concentrations of both dark matter (DM) and intra-cluster medium (ICM) gas. As the high-energy jet particles transverse the DM and the ICM, elastic and inelastic scattering processes generically lead to the production of final-state photons. As first envisioned by Bloom and Wells (1998), and as more recently pointed out by us and others, the scattering of electrons off of DM could lead to a potentially detectable gamma-ray signal, with the parton-level contribution from protons offering dimmer perspectives. …
QCD and Strongly Coupled Gauge Theories: Challenges and Perspectives
2014
We dedicate this document to the memory of Mikhail Polikarpov, who passed away in July 2013. Misha worked with us for decades as a convener of the “Confinement” section of the Quark Confinement and Hadron Spectrum Series. He guided and expanded the scientific discussion of that topic, inspiring and under taking new research avenues. From its initial conception, he supported the enterprise of this document and organized Sect. 8, writing the part on confinement himself. He attracted the XIth Conference on Quark Confinement and the Hadron Spectrum to St. Petersburg (September 8-12, 2014; see http://phys.spbu.ru/confxi.html). His warm and kind personality, his high sense of humor, his ideas in …
An update on nuclear PDFs at the LHeC
2017
The prospects for a measurement of nuclear parton distribution functions (PDFs) at the Large Hadron--Electron Collider are discussed in the light of recent progress made in the front of global analysis of nuclear PDFs.
Oblate Collectivity in the Yrast Structure of 194Pt
2005
A deep inelastic reaction using a 460 MeV 82Se beam incident upon a thick 192Os target was performed at the Legnaro National Laboratory, Italy. The resulting γ-decays were measured using the GASP array. Results for 194Pt extend the known level scheme of the yrast structure from spin I = (12 ħ) to (20 ħ). The irregularities in the sequence of the new transition energies and total Routhian surface calculations show a breakdown in collectivity with an yrast oblate shape remaining to high spin. Rubio Barroso, Berta, Berta.Rubio@ific.uv.es
"Table 3" of "Spin asymmetries A(1) and structure functions g1 of the proton and the deuteron from polarized high energy muon scattering."
1998
The virtual photon proton asymmetries in smaller X and Q**2 bins. bins. Errors are statistical only.