Date: Thu, 30 Jul 15 00:18:19 GMT Subject: nucl-th daily 3 new + 7 crosses received by eprepget ------------------------------------------------------------------------------ ------------------------------------------------------------------------------ Send any comments regarding submissions directly to submitter. ------------------------------------------------------------------------------ Archives at http://arxiv.org/ To unsubscribe, e-mail To: nucl-th@arXiv.org, Subject: cancel ------------------------------------------------------------------------------ received by eprepget from Tue 28 Jul 15 20:00:00 GMT to Wed 29 Jul 15 20:00:00 GMT ------------------------------------------------------------------------------ \\ arXiv:1507.08035 Date: Wed, 29 Jul 2015 06:57:43 GMT (747kb) Title: Nuclear shape coexistence in Po isotopes: An interacting boson model study Authors: J.E. Garcia-Ramos, K. Heyde Categories: nucl-th Comments: To be published in Physical Review C \\ Background: The lead region, Po, Pb, Hg, and Pt, shows up the presence of coexisting structures having different deformation and corresponding to different particle-hole configurations in the Shell Model language. Purpose: We intend to study the importance of configuration mixing in the understanding of the nuclear structure of even-even Po isotopes, where the shape coexistence phenomena are not clear enough. Method: We study in detail a long chain of polonium isotopes, 190-208Po, using the interacting boson model with configuration mixing (IBM-CM). We fix the parameters of the Hamiltonians through a least-squares fit to the known energies and absolute B(E2) transition rates of states up to 3 MeV. Results: We obtained the IBM-CM Hamiltonians and we calculate excitation energies, B(E2)'s, electric quadrupole moments, nuclear radii and isotopic shifts, quadrupole shape invariants, wave functions, and deformations. Conclusions: We obtain a good agreement with the experimental data for all the studied observables and we conclude that shape coexistence phenomenon is hidden in Po isotopes, very much as in the case of the Pt isotopes. \\ ( http://arxiv.org/abs/1507.08035 , 747kb) ------------------------------------------------------------------------------ \\ arXiv:1507.08128 Date: Wed, 29 Jul 2015 13:06:02 GMT (116kb) Title: Why we need an Electron-Ion Collider Authors: Raju Venugopalan (BNL) Categories: nucl-th hep-ex nucl-ex Comments: 6 pages, contribution to appear in a special issue of Annalen Der Physik titled "Particle Physics after the Higgs", Guest Editors: H. Abramowicz, A. Caldwell, B. Foster \\ We present a brief argument making the science case for an electron-ion collider. \\ ( http://arxiv.org/abs/1507.08128 , 116kb) ------------------------------------------------------------------------------ \\ arXiv:1507.08195 Date: Wed, 29 Jul 2015 15:56:16 GMT (242kb,D) Title: Rapidity dependence in holographic heavy ion collisions Authors: Wilke van der Schee and Bjoern Schenke Categories: nucl-th hep-th Comments: 5 pages, 5 figures \\ We present an attempt to closely mimic the initial stage of heavy ion collisions within holography, assuming a decoupling of longitudinal and transverse dynamics in the very early stage. We subsequently evolve the obtained initial state using state-of-the-art hydrodynamic simulations, and compare results to experimental data. We present results for charged hadron pseudo-rapidity spectra and directed and elliptic flow as functions of pseudo-rapidity for $\sqrt{s_{NN}}=200\,{\rm GeV}$ Au-Au and $2.76\,{\rm TeV}$ Pb-Pb collisions. The directed flow interestingly turns out to be quite sensitive to the viscosity. The results can explain qualitative features of the collisions, but the rapidity spectra in our current model is narrower than the experimental data. \\ ( http://arxiv.org/abs/1507.08195 , 242kb) %-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%- ------------------------------------------------------------------------------ \\ arXiv:1507.07942 (*cross-listing*) Date: Tue, 28 Jul 2015 20:07:34 GMT (622kb) Title: Deep inelastic scattering cross sections from the gauge/string duality Authors: Ezequiel Koile, Nicolas Kovensky, Martin Schvellinger Categories: hep-th hep-lat hep-ph nucl-th Comments: 42 pages, 5 tables, 9 figures \\ Differential cross sections of deep inelastic scattering of charged leptons from hadrons are investigated by using the gauge/string duality. We consider vector mesons derived from different holographic dual models obtaining a general expression. We focus on the strongly coupled regime of dual gauge theories for different values of the Bjorken parameter. We find new predictions which are particularly interesting for differential scattering cross sections of polarized leptons scattered off polarized vector mesons. We also carry out a detailed comparison of the moments of the structure functions with lattice QCD results. \\ ( http://arxiv.org/abs/1507.07942 , 622kb) ------------------------------------------------------------------------------ \\ arXiv:1507.08045 (*cross-listing*) Date: Wed, 29 Jul 2015 08:04:40 GMT (145kb) Title: Unraveling the pattern of the $XYZ$ mesons Authors: J. Vijande, A. Valcarce Categories: hep-ph nucl-th Comments: 8 pages, 2 figures Journal-ref: Phys. Lett. B736 (2014) 325-328 DOI: 10.1016/j.physletb.2014.07.048 \\ We present a plausible mechanism for the origin of the $XYZ$ mesons in the heavy meson spectra within a standard quark-model picture. We discuss the conditions required for the existence of four--quark bound states or resonances contributing to the heavy meson spectra, being either compact or molecular. We concentrate on charmonium and bottomonium spectra, where several new states, difficult to understand as simple quark-antiquark pairs, have been reported by different experimental collaborations. The pivotal role played by entangled meson-meson thresholds is emphasized. \\ ( http://arxiv.org/abs/1507.08045 , 145kb) ------------------------------------------------------------------------------ \\ arXiv:1507.08046 (*cross-listing*) Date: Wed, 29 Jul 2015 08:13:18 GMT (1738kb) Title: Multiquark contributions to charm baryon spectroscopy Authors: T.F. Carames, A. Valcarce Categories: hep-ph nucl-th Comments: 15 pages, 7 figures. arXiv admin note: substantial text overlap with arXiv:1204.5502 Journal-ref: Phys. Rev. D90, 014042 (2014) DOI: 10.1103/PhysRevD.90.014042 \\ We study possible multiquark contributions to the charm baryon spectrum by considering higher order Fock space components. For this purpose we perform two different calculations. In a first approach we do a coupled-channel calculation of the $ND$ system looking for molecular states. In a second step we allow for the coupling to a heavy baryon--light meson two-hadron system looking for compact exotic five--quark structures. Both calculations have been done within the framework of a chiral constituent quark model. The model, tuned in the description of the baryon and meson spectra as well as the $NN$ interaction, provides parameter-free predictions for charm $+1$ molecular or compact two-hadron systems. Unlike the $N \bar D$ system, no sharp quark-Pauli effects are found. However, the existence of different two-hadron thresholds for the five-quark system will make the coupled-channel dynamics relevant. Only a few channels are candidates to lodge molecular or compact hadrons with a five-quark structure, being specially relevant the $(T)J^P=(0)1/2^-$ and $(T)J^P=(2)5/2^-$ channels. The identification of molecular states and/or compact hadrons with multiquark components either with or without exotic quantum numbers is a challenge of different collaborations like $\bar {\rm P}$ANDA, LHCb, ExHIC or J-PARC. \\ ( http://arxiv.org/abs/1507.08046 , 1738kb) ------------------------------------------------------------------------------ \\ arXiv:1507.08061 (*cross-listing*) Date: Wed, 29 Jul 2015 08:44:24 GMT (5kb) Title: Nonexistence of a $\Lambda nn$ bound state Authors: H. Garcilazo, A. Valcarce Categories: hep-ph nucl-th Comments: 5 pages Journal-ref: Phys.Rev. C89, 057001 (2014) DOI: 10.1103/PhysRevC.89.057001 \\ It has been recently suggested the existence of a neutral bound state of two neutrons and a $\Lambda$ hyperon, $^3_\Lambda n$. We point out that using either simple separable potentials or a full-fledged calculation with realistic baryon-baryon interactions derived from the constituent quark cluster model there is no possibility for the existence of such a $\Lambda nn$ bound state. For this purpose, we performed a full Faddeev calculation of the $\Lambda nn$ system in the $(I,J^P)=(1,1/2^+)$ channel using the interactions derived from the constituent quark cluster model which describe well the two-body $NN$ and $NY$ data and the $\Lambda np$ hypertriton. \\ ( http://arxiv.org/abs/1507.08061 , 5kb) ------------------------------------------------------------------------------ \\ arXiv:1507.08143 (*cross-listing*) Date: Wed, 29 Jul 2015 13:43:21 GMT (155kb) Title: Spontaneous mass generation and the small dimensions of the Standard Model gauge groups U(1), SU(2) and SU(3) Authors: Guillermo Garcia Fernandez, Jesus Guerrero Rojas and Felipe J. Llanes-Estrada (U. Complutense Madrid) Categories: hep-ph hep-th nucl-th Comments: 12 pages, 17 plots \\ The gauge symmetry of the Standard Model is U(1) x SU(2)_L x SU(3) for unknown reasons. One aspect that can be addressed is the low dimensionality of all its subgroups. Why not much larger groups like SU(7) or for that matter, SP(38) or E7? We observe that fermions charged under large groups acquire much bigger dynamical masses, all things being equal at a high e.g. GUT scale, than ordinary quarks. Should such multicharged fermions exist, they are too heavy to be observed today and have either decayed early on (if they couple to the rest of the Standard Model) or become reliquial dark matter (if they don't). The result follows from strong antiscreening of the running coupling for the larger group together with scaling properties of the Dyson-Schwinger equation for the fermion mass. \\ ( http://arxiv.org/abs/1507.08143 , 155kb) ------------------------------------------------------------------------------ \\ arXiv:1507.08197 (*cross-listing*) Date: Wed, 29 Jul 2015 16:06:11 GMT (200kb) Title: Dark Compact Planets Authors: Laura Tolos and Juergen Schaffner-Bielich Categories: astro-ph.HE hep-ph nucl-th Comments: 4 pages, 3 figures \\ We investigate compact objects formed by dark matter admixed with ordinary matter made of neutron star matter and white dwarf material. We consider non-self annihilating dark matter with an equation-of-state given by an interacting Fermi gas. We find new stable solutions, dark compact planets, with Earth-like masses and radii from few Km to few hundred Km for weakly interacting dark matter. For the strongly interacting dark matter case, we obtain dark compact planets with Jupiter-like masses and radii of few hundred Km. These objects could be formed primordially and accrete white dwarf material subsequently. They could be detected by observing exoplanets with unusually small radii. Moreover, we find that the recently observed 2 ${\rm M}_{\odot}$ pulsars set limits on the amount of dark matter inside neutron stars which is, at most, $10^{-6}{\rm M}_\odot$. \\ ( http://arxiv.org/abs/1507.08197 , 200kb) ------------------------------------------------------------------------------ \\ arXiv:1507.08230 (*cross-listing*) Date: Wed, 29 Jul 2015 17:17:56 GMT (209kb,D) Title: Numerical study of the unitary Fermi gas across the superfluid transition Authors: Olga Goulko, Matthew Wingate Categories: cond-mat.quant-gas hep-lat nucl-th Report-no: DAMTP-2015-38 \\ We present results from Monte Carlo calculations investigating the properties of the homogeneous, spin-balanced unitary Fermi gas in three dimensions. The temperature is varied across the superfluid transition allowing us to determine the temperature dependence of the chemical potential, the energy per particle and the contact density. Numerical artifacts due to finite volume and discretization are systematically studied and removed. \\ ( http://arxiv.org/abs/1507.08230 , 209kb) %%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%% ------------------------------------------------------------------------------ \\ arXiv:1504.03245 replaced with revised version Tue, 28 Jul 2015 20:49:58 GMT (2124kb) Title: Properties of nuclei in the nobelium region studied within the covariant, Skyrme, and Gogny energy density functionals Authors: J. Dobaczewski, A.V. Afanasjev, M. Bender, L.M. Robledo, Yue Shi Categories: nucl-th Comments: 43 LaTeX pages, 14 figures, accepted in Nuclear Physics A, Special Issue on Superheavy Elements \\ ( http://arxiv.org/abs/1504.03245 , 2124kb) ------------------------------------------------------------------------------ \\ arXiv:1505.00848 (*cross-listing*) replaced with revised version Wed, 29 Jul 2015 04:37:01 GMT (250kb,D) Title: Phonons, pions and quasi-long-range order in spatially modulated chiral condensates Authors: Yoshimasa Hidaka, Kazuhiko Kamikado, Takuya Kanazawa, Toshifumi Noumi Categories: hep-ph hep-th nucl-th Comments: 17 pages, 9 figures. v2: minor changes, published version Report-no: RIKEN-QHP-185, RIKEN-STAMP-4 \\ ( http://arxiv.org/abs/1505.00848 , 250kb) ------------------------------------------------------------------------------ \\ arXiv:1505.01106 (*cross-listing*) replaced with revised version Wed, 29 Jul 2015 02:10:00 GMT (144kb,D) Title: Hagedorn spectrum and thermodynamics of SU(2) and SU(3) Yang-Mills theories Authors: Michele Caselle, Alessandro Nada and Marco Panero Categories: hep-lat hep-th nucl-th Comments: 1+19 pages, 4 pdf figures; v2: 1+22 pages, 4 pdf figures, improved discussion in sections 3 and 4, added references, corrected misprints: matches the journal version Journal-ref: JHEP 07 (2015) 143 DOI: 10.1007/JHEP07(2015)143 \\ ( http://arxiv.org/abs/1505.01106 , 144kb) ------------------------------------------------------------------------------ \\ arXiv:1505.02849 (*cross-listing*) replaced with revised version Wed, 29 Jul 2015 13:15:48 GMT (120kb) Title: $\Xi (1690)$ as a $\bar{K} \Sigma$ molecular state Authors: Takayasu Sekihara (RCNP, Osaka U.) Categories: hep-ph hep-ex hep-lat nucl-ex nucl-th Comments: 10 pages, 3 eps files, discussions improved throughout the manuscript and references added \\ ( http://arxiv.org/abs/1505.02849 , 120kb) ------------------------------------------------------------------------------ \\ arXiv:1505.07379 (*cross-listing*) replaced with revised version Wed, 29 Jul 2015 11:25:21 GMT (37kb,D) Title: Chiral drag force Authors: Krishna Rajagopal, Andrey V. Sadofyev Categories: hep-th hep-ph nucl-th Comments: 28 pages, small improvement to the discussion of gravitational anomaly, references added Report-no: MIT-CTP-4676 \\ ( http://arxiv.org/abs/1505.07379 , 37kb) %%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%--- For subscribe options to combined physics archives, e-mail To: physics@arxiv.org, Subject: subscribe ----------------------------------------------------------------------------- For help on viewing and making submissions, see http://arxiv.org/help/