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Nuclear Theory·nucl-th

Tuesday·April 4, 2017

15 papers—8 primary·7 cross-listed

All15Primary8Cross-lists7
  1. 09

    Numerical calculation of the decay widths, the decay constants, and the decay energy spectra of the resonances of the delta-shell potential

    Rafael de la Madrid🇺🇸

    We express the resonant energies of the delta-shell potential in terms of the Lambert function, and we calculate their decay widths and decay constants. The ensuing numerical results strengthen the interpretation of such decay widths and constants as a way to quantify the coupling between a resonance and the continuum. We calculate explicitly the decay energy spectrum of the resonances of the delta-shell potential, and we show numerically that the lineshape of such spectrum is not the same as, and can be very different from, the Breit-Wigner (Lorentzian) distribution. We argue that the standard Golden Rule cannot describe the interference of two resonances, and we show how to describe such interference by way of the decay energy spectrum of two resonant states.

    ↳ quant-phhep-phnucl-thNPA(2017)·16 citations
  2. 10

    Peeking into the Origins of IceCube Neutrinos: I. Buried Transient TeV Miniburst Rates

    Matthew D. Kistler (KIPAC, Stanford, SLAC)🇺🇸 · Hasan Yuksel (Mimar Sinan)🇹🇷

    Any interpretation of the astrophysical neutrinos discovered by IceCube must accommodate a variety of multimessenger constraints. We address implications of these neutrinos being produced in transient sources, principally if buried within supernovae so that gamma rays are absorbed by the star. This would alleviate tension with the isotropic Fermi GeV background that >10 TeV neutrinos rival in detected energy flux. We find that IceCube data constrain transient properties, implying buried GeV-TeV electromagnetic emission near or exceeding canonical SN explosion energies of ~10^51 erg, indicative of an origin within superluminous SNe. TeV neutrino bursts with dozens of IceCube events -- which would be of great use for understanding r-process nucleosynthesis and more -- may be just around the corner if they are a primary component of the flux.

    ↳ astro-ph.HEastro-ph.COastro-ph.GAhep-ph+12 citations
  3. 11

    Experimental constraint on quark electric dipole moments

    Tianbo Liu🇺🇸 · Zhiwen Zhao🇺🇸 · Haiyan Gao🇺🇸

    The electric dipole moments (EDMs) of nucleons are sensitive probes of additional violation sources beyond the standard model to account for the baryon number asymmetry of the universe. As a fundamental quantity of the nucleon structure, tensor charge is also a bridge that relates nucleon EDMs to quark EDMs. With a combination of nucleon EDM measurements and tensor charge extractions, we investigate the experimental constraint on quark EDMs, and its sensitivity to violation sources from new physics beyond the electroweak scale. We obtain the current limits on quark EDMs as for the up quark and for the down quark at the scale of . We also study the impact of future nucleon EDM and tensor charge measurements, and show that upcoming new experiments will improve the constraint on quark EDMs by about three orders of magnitude leading to a much more sensitive probe of new physics models.

    ↳ hep-phhep-exnucl-exnucl-thPRD(2018)·42 citations
  4. 12

    Excited states of the Wick-Cutkosky model with the Nakanishi representation in the Light-Front framework

    R. Pimentel🇧🇷 · W. de Paula🇧🇷

    The Wick-Cutkosky model is investigated using the framework of the Nakanishi Perturbative Integral Representation projected in the Light-Front hyperplane for an s-wave amplitude. We developed a new technique based on sucessive integration by parts of the Nakanishi Representation which enabled us to transform one of the integrations into a sum. With a set of boundary conditions it was possible to guess the format of the solution, which was in fact a distribution. The eigenequations obtained were the same as the originals of Cutkosky \cite{CutPR54}. Finally, a numerical check confirmed that the final equation reproduce the same eigenvalues as the initial Bethe-Salpeter equation.

    ↳ hep-phmath-phmath.MPnucl-thFew Body Syst.(2016)·7 citations
  5. 13

    Quantum Numbers of Recently Discovered Baryons from Lattice QCD

    M. Padmanath🇩🇪 · Nilmani Mathur🇮🇳

    We present the ground and excited state spectra of baryons with spin up to 7/2 from lattice quantum chromodynamics with dynamical quark fields. Based on our lattice results, we predict the quantum numbers of five baryons, which have recently been observed by the LHCb Collaboration. Our results strongly indicate that the observed states and have spin-parity , the states and have , whereas is possibly a state.

    ↳ hep-phhep-exhep-latnucl-thPRL(2017)·115 citations
  6. 14

    Effect of strong magnetic fields on the crust-core transition and inner crust of neutron stars

    Jianjun Fang · Helena Pais · Sagar Pratapsi · Sidney Avancini · Jing Li · Constança Providência

    The Vlasov equation is used to determine the dispersion relation for the eigenmodes of magnetized nuclear and neutral stellar matter, taking into account the anomalous magnetic moment of nucleons. The formalism is applied to the determination of the dynamical spinodal section, a quantity that gives a good estimation of the crust-core transition in neutron stars. We study the effect of strong magnetic fields, of the order of G, on the extension of the crust of magnetized neutron stars. The dynamical instability region of neutron-proton-electron () matter at subsaturation densities is determined within a relativistic mean field model. It is shown that a strong magnetic field has a large effect on the instability region, defining the crust-core transition as a succession of stable and unstable regions due to the opening of new Landau levels. The effect of the anomalous magnetic moment is non-negligible for fields larger than 10 G. The complexity of the crust at the transition to the core and the increase of the crust thickness may have direct impact on the properties of neutrons stars related with the crust.

    ↳ astro-ph.HEnucl-thPRC(2017)·31 citations
  7. 15

    Proton Cumulants and Correlation Functions in Au + Au Collisions at =7.7-200 GeV from UrQMD Model

    Shu He🇨🇳 · Xiaofeng Luo🇨🇳

    We studied the acceptance dependence of proton cumulants (up to fourth order) and correlation functions in 0--5\% most central Au+Au collisions at =7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV from UrQMD model. We found that high order proton cumulants show suppressions at large acceptance. By decomposing the proton cumulants into linear combination of multi-proton correlation functions, we observed the two-proton correlation functions always show negative values due to the effects of baryon number conservations. The three and four-proton correlation functions are close to zero and show negligible acceptance dependence. We further observed that the proton cumulants and correlation functions follow similar trends and show a scaling behavior when plotting the results versus mean number of protons. The comparisons between experimental data and the UrQMD calculations show that the non-monotonic energy dependence of proton correlation functions measured by STAR experiment cannot be described by the UrQMD model. The UrQMD calculations can provide us baselines for the experimental studies of the proton cumulants and correlation functions. Finally, we propose to measure the rapidity dependence of the reduced proton correlation functions to search for the QCD critical point in heavy-ion collisions.

    ↳ nucl-exhep-exhep-phnucl-thPLB(2017)·38 citations

Affiliations

first authorsco-authorsvia INSPIRE