224 research outputs found
Nuclear and partonic dynamics in the EMC effect
It has been recently confirmed that the magnitude of the EMC effect measured
in electron deep inelastic scattering is linearly related to the Short Range
Correlation scaling factor obtained from electron inclusive scattering. By
using a -rescaling approach we are able to understand the interplay between
the quark-gluon and hadronic degrees of freedom in the discussion of the EMC
effect.Comment: 5 pages, 6 figures, 2 table. We have incorporated SLAC data and
redone the calculation with the newest ROOT 5.3
Medium Effects in DIS from Polarized Nuclear Targets
The behavior of the nucleon structure functions in lepton nuclei deep
inelastic scattering, both polarized and unpolarized, due to nuclear structure
effects is reanalyzed. The study is performed in two schemes: an x-rescaling
approach, and one in which there is an increase of sea quark components in the
in medium nucleon, related to the low energy N-N interaction. In view of a
recent interesting experimental proposal to study the behavior of the proton
spin structure functions in nuclei we proceed to compare these approaches in an
effort to enlighten the possible phenomenological interest of such difficult
experiment.Comment: 11 pages and 5 figure
LHC updated hadronic interaction packages analyzed up to cosmic-ray energies
The results of high energy simulated experiments where a given hadronic particle impacts on a given target are statistically analyzed. The energy range of the projectiles goes from below the LHC scale up to the highest cosmic ray energies. This study was carried out by using the pre- and post-LHC versions of the hadronic interaction models QGSJET, EPOS and SIBYLL. Our analysis indicates that the post-LHC models present smaller differences in various quantities that characterize the secondary particles produced after the hadronic collisions, in comparison with the corresponding differences that are found comparing the respective old (pre-LHC) versions of the hadronic models. However, it is also found that there exist some discrepancies among models that persist even at the LHC energy scale, that call for further theoretical investigation. An additional analysis of the impact that different modeling of hadronic collisions has on air shower development is also included. It consists of a detailed study of the impact of the different pre- and post-LHC versions of the hadronic models considered, for relevant observables like the muon production depth distribution.Fil: Calcagni, Laura Randa. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de FĂsica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂŠcnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de FĂsica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂsica La Plata; ArgentinaFil: GarcĂa Canal, Carlos Alberto. Consejo Nacional de Investigaciones CientĂficas y TĂŠcnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de FĂsica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂsica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de FĂsica; ArgentinaFil: Sciutto, Sergio Juan. Consejo Nacional de Investigaciones CientĂficas y TĂŠcnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de FĂsica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂsica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de FĂsica; ArgentinaFil: Tarutina, Tatiana. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de FĂsica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂŠcnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de FĂsica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂsica La Plata; Argentin
Multipole decomposition of the cross section of the neutrino-lead scattering process 208Pb(g.s.)(ν,ν)208Pbâ
We calculate neutral-current contributions to the process ν+208Pb(g.s)â νâ˛+208Pbâ, for incoming neutrino energies up to 150 MeV. The spectrum of 208Pb is calculated by performing a diagonalization of the δ-force interaction in the space of particle-hole pairs, both for neutrons and protons. We study the dependence of the cross section on the energy of the neutrino and present its multipole decomposition for normal and abnormal parity states. We compare our results to the estimate of neutral-current contributions by other authors, and to our previous results for the charged-current channel.Instituto de FĂsica La Plat
Interference effects in the Coulomb dissociation of 15,17,19C
In this work the semiclassical model of pure Coulomb excitation was applied
to the breakup of 15,17,19C. The ground state wave functions were calculated in
the particle-rotor model including core excitation. The importance of
interference terms in the dipole strength arising after including core degrees
of freedom is analyzed for each isotope. It is shown that Coulomb interference
effects are important for the case of 17C.Comment: 17 pages, 5 figures accepted to Physical Review
Nuclear response to dark matter signals in Ge and Xe odd-mass targets
Abstract: The interaction of dark matter particles (WIMPs) with the odd-mass
Ge and Xe target nuclei ,{ {that is the recoil rates
corresponding to the elastic scattering of WIMPs by these nuclei}}, is analysed
in the context of the minimal extensions of the SUSY model. The BCS+QRPA
technique plus the quasiparticle-phonon coupling scheme is used to describe the
nuclear structure part of the calculations. The resulting values for the
nuclear spin content of both nuclei are compared to values previously reported
in the literature
Scaler mode of the Auger Observatory and sunspots
Recent data from the Auger Observatory on low-energy secondary cosmic ray particles are analyzed to study temporal correlations together with data on the daily sunspot numbers and neutron monitor data. Standard spectral analysis demonstrates that the available data show 1/f β fluctuations with β â 1 in the low-frequency range. All data behave like Brownian fluctuations in the high-frequency range. The existence of long-range correlations in the data was confirmed by detrended fluctuation analysis. The real data confirmed the correlation between the scaling exponent of the detrended analysis and the exponent of the spectral analysis.Instituto de FĂsica La Plat
Disentangling the Seesaw in the Left-Right Model -- An Algorithm for the General Case
Senjanovic and Tello have analyzed how one could determine the neutrino Dirac
mass matrix in the minimal left-right model, assuming that the mass matrices
for the light and heavy neutrinos could be taken as inputs. They have provided
an analytical solution for the Dirac mass matrix in the case that the
left-right symmetry is implemented via a generalized parity symmetry and that
this symmetry remains unbroken in the Dirac Yukawa sector. We extend the work
of Senjanovic and Tello to the case in which the generalized parity symmetry is
broken in the Dirac Yukawa sector. In this case the elegant method outlined by
Senjanovic and Tello breaks down and we need to adopt a numerical approach.
Several iterative approaches are described; these are found to work in some
cases but to be highly unstable in others. A stable, prescriptive numerical
algorithm is described that works in all but a vanishingly small number of
cases. We apply this algorithm to numerical data sets that are consistent with
current experimental constraints on neutrino masses and mixings. We also
provide some additional context and supporting explanations for the case in
which the parity symmetry is unbroken.Comment: 34 pages, 4 figures; published versio
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