Fri·Jan 6, 2017Friday·January 6, 2017

1. 01*

   Fuzzy Dark Matter from Infrared Confining Dynamics

   Hooman Davoudiasl🇺🇸 · Christopher W. Murphy🇺🇸

   A very light boson of mass $\mathcal{O}(10^{-22})$ eV may potentially be a viable dark matter (DM) candidate which can avoid phenomenological problems associated with cold DM. Such "fuzzy DM (FDM)" may naturally be an axion with a decay constant $f_a\sim 10^{16}÷10^{18}$ GeV, and a mass $m_a\sim {\mu }^2/f_a$ with $\mu \sim 10^2$ eV. Here we propose a concrete model where $\mu$ arises as a dynamical scale from infrared confining dynamics, analogous to QCD. Our model is an alternative to the usual approach of generating $\mu$ through string theoretic instanton effects. We outline the features of this scenario that result from various cosmological constraints. We find that those constraints are suggestive of a period of mild of inflation, perhaps from a strong first order phase transition, that reheats the Standard Model (SM) sector only. A typical prediction of our scenario, broadly speaking, is a larger effective number of neutrinos compared to the SM value $N_{\text{eff}}\approx 3$, as inferred from precision measurements of the cosmic microwave background. Some of the new degrees of freedom may be identified as "sterile neutrinos," which may be required to explain certain neutrino oscillation anomalies. Hence, aspects of our scenario could be testable in terrestrial experiments, which is a novelty of our FDM model.

   hep-phastro-ph.COPRL(2017)·35 citations
2. 02*

   Parton saturation scaling function for exclusive production of vector mesons and Deeply Virtual Compton Scattering

   F.G. Ben🇧🇷 · M.V.T. Machado🇧🇷 · W.K. Sauter🇧🇷

   We provide a universal expression of cross sections for the exclusive vector meson production and Deeply Virtual Compton Scattering (DVCS) in photon-proton and photon-nucleus interactions based on the geometric scaling phenomenon. The theoretical parameterization based on the scaling property depends only on the single variable ${\tau }_A=Q^2/Q_{\mathrm{sat}}^2$, where the saturation scale, $Q_{\mathrm{sat}}$, drives the energy dependence and the corresponding nuclear effects. This phenomenological result describes all available data from DESY-HERA for $\rho ,\varphi ,J/\psi$ production and DVCS measurements. A discussion on the size of nuclear shadowing corrections on photon-nucleus interaction is also done.

   hep-phhep-exnucl-exPRD(2017)·18 citations
3. 03*

   Transverse single-spin asymmetries in $\ell p^{\uparrow }\to hX$ within a TMD approach: Role of quasireal photon exchange

   Umberto D'Alesio🇮🇹 · Carlo Flore🇮🇹 · Francesco Murgia🇮🇹

   We present an updated study of transverse single-spin asymmetries for the inclusive large-$P_T$ processes $\ell p^{\uparrow }\to hX$ and $\ell p^{\uparrow }\to \mathrm{jet}X$, within a transverse momentum-dependent approach, including the contribution of quasireal (Weizsäcker-Williams) photons. In the spirit of a unified transverse momentum-dependent scheme, predictions are obtained adopting the Sivers and transversity distributions and the Collins fragmentation functions as extracted from fits to the azimuthal asymmetries measured in semi-inclusive deep inelastic scattering and $e^{+}{e}^{-}$ annihilation processes. The description of the available data is extremely good, showing a clear general improvement with respect to the previous leading-order analysis. Predictions for unpolarized cross sections and single-spin asymmetries for ongoing and future experiments are also given.

   hep-phPRD(2017)·14 citations
4. 04*

   Heavy quarks within the electroweak multiplet

   J. Besprosvany🇲🇽 · R. Romero🇲🇽

   Standard-model fields and their associated electroweak Lagrangian are equivalently expressed in a shared spin basis. The scalar-vector terms are written with scalar-operator components acting on quark-doublet elements, and shown to be parametrization-invariant. Such terms, and the t- and b-quark Yukawa terms are linked by the identification of the common mass-generating Higgs operating upon the other fields, after acquiring a vacuum expectation value $v$. Thus, the customary vector masses are related to the fermions', fixing the t-quark mass $m_t$ with the relation $m_t^2+m_b^2=v^2/2$ either for maximal hierarchy, or given the b-quark mass $m_b$, implying $m_t\simeq 173.9$ GeV, for $v=246$ GeV. A sum rule is derived for all quark masses that generalizes this restriction. An interpretation follows that electroweak bosons and heavy quarks belong in a multiplet.

   hep-phPRD(2019)·2 citations
5. 05*

   Constraining dark photon model with dark matter from CMB spectral distortions

   Ki-Young Choi🇰🇷 · Kenji Kadota🇰🇷 · Inwoo Park🇰🇷

   Many extensions of Standard Model (SM) include a dark sector which can interact with the SM sector via a light mediator. We explore the possibilities to probe such a dark sector by studying the distortion of the CMB spectrum from the blackbody shape due to the elastic scatterings between the dark matter and baryons through a hidden light mediator. We in particular focus on the model where the dark sector gauge boson kinetically mixes with the SM and present the future experimental prospect for a PIXIE-like experiment along with its comparison to the existing bounds from complementary terrestrial experiments.

   hep-phastro-ph.COPLB(2017)·9 citations
6. 06*

   Preheating in an inflationary model with disformal coupling

   Khamphee Karwan (Naresuan U.)🇹🇭 · Phongpichit Channuie (Walailak U.)🇹🇭

   In this work, we investigate the preheating mechanism in a disformally-coupled inflationary model where the scalar field $\varphi$ (which is the inflaton field) naturally coupled to another matter field $\chi$ induced by the disformal transformation. In the present scenario, novel derivative interactions mixing the kinetic terms of the two fields emerge inherently. We start by deriving the evolution of the background system when the back reaction on the background field is neglected. We examine the particle production due to parametric resonances in the models and find in Minkowski space that the stage of parametric resonances can be described by the Mathieu equation. Interestingly, we discover that broad resonances in our models can be typically achieved. Finally, we compare our results with previously studied model with derivative couplings.

   hep-phgr-qchep-thPRD(2017)·5 citations
7. 07*

   Fine structure of the diffraction cone: manifestation of t channel unitarity

   László Jenkovszky🇺🇦 · István Szanyi🇺🇦

   We show that the deviation from exponential behavior of the diffraction cone observed near t=-0.1 GeV^2 both at ISR and the LHC (so-called break) follows from a two-pion loop in the t channel, imposed by unitarity. By using a simple Regge-pole model, we extrapolate the "break" from the ISR energy region to that of the LHC.

   hep-phhep-exPhys.Part.Nucl.Lett.(2017)·9 citations
8. 08*

   Charmless $B_{(s)}\to VV$ Decays in Factorization-Assisted Topological-Amplitude Approach

   Chao Wang🇨🇳 · Qi-An Zhang🇨🇳 · Ying Li🇨🇳 · Cai-Dian Lu🇨🇳

   Within the factorization-assisted topological-amplitude approach, we studied the 33 charmless $B_{(s)}\to VV$ decays, where $V$ stands for a light vector meson. According to the flavor flows, the amplitude of each process can be decomposed into 8 different topologies. In contrast to the conventional flavor diagrammatic approach, we further factorize each topological amplitude into decay constant, form factors and unknown universal parameters. By ${\chi }^2$ fitting 46 experimental observables, we extracted 10 theoretical parameters with ${\chi }^2$ per degree of freedom around 2. Using the fitted parameters, we calculated the branching fractions, polarization fractions, CP asymmetries and relative phases between polarization amplitudes of each decay mode. The decay channels dominated by tree diagram have large branching fractions and large longitudinal polarization fraction. The branching fractions and longitudinal polarization fractions of color-suppressed decays become smaller. Current experimental data of large transverse polarization fractions in the penguin dominant decay channels can be explained by only one transverse amplitude of penguin annihilation diagram. Our predictions of those not yet measured channels can be tested in the ongoing LHCb experiment and the Belle-II experiment in future.

   hep-phhep-exEPJC(2017)·47 citations
9. 09*

   Extended soft wall model with background related to features of QCD thermodynamics

   Rico Zöllner🇩🇪 · Burkhard Kampfer🇩🇪

   The soft wall model is extended to accommodate at the same time (i) approximately linear $\rho$ meson Regge trajectories at zero temperature $T$, (ii) various options for the thermodynamics with reference to QCD (cross over or second-order transition or first-order transition at $T_c$), and (iii) the appearance of vector meson states at $T\le T_c$. While the vector meson masses display some modest model dependence very near to $T_c$, they stay below $T_c$ to good accuracy independent of the temperature, that is nearly as at $T=0$, thus being very consistent with the thermo-statistical models widely employed in analyses of the hadron yields in relativistic heavy-ion collisions in a region where baryon densitiy effects can be neglected and the vacuum hadron masses are used.

   hep-phhep-thEPJA(2017)·9 citations
10. 10*

    A model of neutrino mass and dark matter with large neutrinoless double beta decay

    Julien Alcaide🇪🇸 · Dipankar Das🇪🇸 · Arcadi Santamaria🇪🇸

    We propose a model where neutrino masses are generated at three loop order but neutrinoless double beta decay occurs at one loop. Thus we can have large neutrinoless double beta decay observable in the future experiments even when the neutrino masses are very small. The model receives strong constraints from the neutrino data and lepton flavor violating decays, which substantially reduces the number of free parameters. Our model also opens up the possibility of having several new scalars below the TeV regime, which can be explored at the collider experiments. Additionally, our model also has an unbroken $Z_2$ symmetry which allows us to identify a viable Dark Matter candidate.

    hep-phJHEP(2017)·17 citations
11. 11*

    The five-loop beta function of Yang-Mills theory with fermions

    F. Herzog🇳🇱 · B. Ruijl🇳🇱 · T. Ueda🇳🇱 · J.A.M. Vermaseren (NIKHEF, Amsterdam)🇳🇱 · A. Vogt (Liverpool U., Dept. Math.)🇬🇧

    We have computed the five-loop corrections to the scale dependence of the renormalized coupling constant for Quantum Chromodynamics (QCD), its generalization to non-Abelian gauge theories with a simple compact Lie group, and for Quantum Electrodynamics (QED). Our analytical result, obtained using the background field method, infrared rearrangement via a new diagram-by-diagram implementation of the R* operation and the Forcer program for massless four-loop propagators, confirms the QCD and QED results obtained by only one group before. The numerical size of the five-loop corrections is briefly discussed in the standard MSbar scheme for QCD with n_f flavours and for pure SU(N) Yang-Mills theory. Their effect in QCD is much smaller than the four-loop contributions, even at rather low scales.

    hep-phJHEP(2017)·498 citations
12. 12*

    Neutrinoless double beta decay and chiral $SU(3)$

    V. Cirigliano🇺🇸 · W. Dekens🇺🇸 · M. Graesser🇺🇸 · E. Mereghetti🇺🇸

    TeV-scale lepton number violation can affect neutrinoless double beta decay through dimension-9 $\Delta L=\Delta I=2$ operators involving two electrons and four quarks. Since the dominant effects within a nucleus are expected to arise from pion exchange, the ${\pi }^{-}\to {\pi }^{+}ee$ matrix elements of the dimension-9 operators are a key hadronic input. In this letter we provide estimates for the ${\pi }^{-}\to {\pi }^{+}$ matrix elements of all Lorentz scalar $\Delta I=2$ four-quark operators relevant to the study of TeV-scale lepton number violation. The analysis is based on chiral $SU(3)$ symmetry, which relates the ${\pi }^{-}\to {\pi }^{+}$ matrix elements of the $\Delta I=2$ operators to the $K^0\to {\bar{K}}^0$ and $K\to \pi \pi$ matrix elements of their $\Delta S=2$ and $\Delta S=1$ chiral partners, for which lattice QCD input is available. The inclusion of next-to-leading order chiral loop corrections to all symmetry relations used in the analysis makes our results robust at the $30\%$ level or better, depending on the operator.

    hep-phhep-latnucl-thPLB(2017)·54 citations
13. 13*

    A renormalization method for three-boson system with a triboson field

    Shung-Ichi Ando🇰🇷

    A renormalization method that introduces an auxiliary field to represent a three-body bound state is studied in a three-boson system with a triboson field. A cutoff dependence in the three-boson system emerges as a limit cycle, and the cyclic singularity is renormalized by employing two methods: a standard method and the auxiliary field method. For each method, different sets of diagrams are involved for renormalization, and thus we numerically study three quantities: counter term for renormalization, scattering length of $s$-wave boson-diboson scattering, and normalized wavefunction. We confirm that the two methods would lead to the same result.

    ↳ nucl-thhep-phJ.Korean Phys.Soc.(2017)·1 citation
14. 14*

    Medium modification of averaged jet charge in heavy-ion collisions

    Shi-Yong Chen🇨🇳 · Ben-Wei Zhang🇨🇳 · En-Ke Wang🇨🇳

    Jet charge characterizes the electric charge distribution inside a jet. In this talk we make the first theoretical study of jet charge in high-energy nuclear collisions and calculate numerically the medium alternations of jet charge due to parton energy loss in the quark-gluon plasma. The parton multiple scattering in hot/dense QCD medium is simulated by a modified version of PYQUEN Monte Carlo model with 3+1D ideal hydrodynamical evolution of the fireball. Our preliminary results show that the averaged jet charge is significant modified in A+A collisions relative to that in p+p. The different features of quark jet charge and gluon jet charge in heavy-ion collisions, and the sensitivity of jet charge modifications to flavour dependence of energy loss are observed, which could then be used to discriminate quark and gluon jet as well as their energy loss patterns in heavy-ion collisions.

    ↳ nucl-thhep-phNucl.Part.Phys.Proc.(2017)·2 citations
15. 15*

    Vorticity in heavy-ion collisions at the JINR Nuclotron-based Ion Collider fAcility

    Yu. B. Ivanov🇷🇺 · A. A. Soldatov🇷🇺

    Vorticity of matter generated in noncentral heavy-ion collisions at energies of the Nuclotron-based Ion Collider fAcility (NICA) at the Joint Institute for Nuclear Research (JINR) in Dubna is studied. Simulations are performed within the model of the three-fluid dynamics (3FD) which reproduces the major part of bulk observables at these energies. Comparison with earlier calculations is done. Qualitative pattern of the vorticity evolution is analyzed. It is demonstrated that the vorticity is mainly located at the border between participants and spectators. In particular, this implies that the relative $\Lambda$-hyperon polarization should be stronger at rapidities of the fragmentation regions than that in the midrapidity region.

    ↳ nucl-thhep-phPRC(2017)·47 citations
16. 16*

    Fundamental physics with the Hubble Frontier Fields: constraining Dark Matter models with the abundance of extremely faint and distant galaxies

    Nicola Menci🇮🇹 · Alexander Merle🇩🇪 · Maximilian Totzauer🇩🇪 · Aurel Schneider🇨🇭 · Andrea Grazian🇮🇹 · Marco Castellano🇮🇹 · Norma G. Sanchez🇫🇷

    We show that the measured abundance of ultra-faint lensed galaxies at $z\approx 6$ in the Hubble Frontier Fields (HFF) provides stringent constraints on the parameter space of i) Dark Matter models based on keV sterile neutrinos; ii) the "fuzzy" wavelike Dark Matter models, based on Bose-Einstein condensate of ultra-light particles. For the case of the sterile neutrinos, we consider two production mechanisms: resonant production through the mixing with active neutrinos and the decay of scalar particles. For the former model, we derive constraints for the combination of sterile neutrino mass $m_{\nu }$ and mixing parameter ${\sin }^2(2\theta )$ which provide the tightest lower bounds on the mixing angle (and hence on the lepton asymmetry) derived so far by methods independent of baryonic physics. For the latter we compute the allowed combinations of the scalar mass, its coupling to the Higgs field, and the Yukawa coupling of the scalar to the sterile neutrinos. We compare our results to independent, existing astrophysical bounds on sterile neutrinos in the same mass range. For the case of "fuzzy" Dark Matter, we show that the observed number density $\approx 1/{\mathrm{Mpc}}^3$ of high-redshift galaxies in the HFF sets a lower limit $m_{\psi }\ge 8\cdot 10^{-22}$ eV (at 3-$\sigma$ confidence level) on the particle mass, a result that strongly disfavors wavelike bosonic Dark Matter as a viable model for structure formation. We discuss the impact on our results of uncertainties due to systematics in the selection of highly magnified, faint galaxies at high redshifts.

    ↳ astro-ph.COastro-ph.GAhep-phhep-thApJ(2017)·80 citations
17. 17*

    KM3NeT-ORCA: Oscillation Research with Cosmics in the Abyss

    Paschal Coyle🇫🇷

    KM3NeT, currently under construction in the abysses of the Mediterranean Sea, is a distributed research infrastructure that will host a km3-scale neutrino telescope (ARCA) for high-energy neutrino astronomy, and a megaton scale detector (ORCA) for neutrino oscillation studies of atmospheric neutrinos. ORCA is optimised for a measurement of the mass hierarchy, providing a sensitivity of 3{\sigma} after 3-4 years. It will also measure the atmospheric mixing parameters $\Delta m_{32}^2$ and ${\theta }_{23}$ with a precision comparable to the NOvA and T2K experiments using both the muon neutrino disappearance and tau neutrino appearance channels. It will provide a measurement of the tau neutrino appearance rate with better than 10% precision, a crucial ingredient for tests of unitarity. It will probe the octant of the mixing angle ${\theta }_{23}$ via matter resonance effects on neutrinos and antineutrinos crossing the core and mantle, which are largely independent on the CP phase. The observation of neutrino oscillations over a wide range of baselines and energies will provide broad sensitivity to new physics such as non-standard neutrino interactions (NSI) and sterile neutrinos.

    ↳ physics.ins-detastro-ph.HEhep-exhep-phJ.Phys.Conf.Ser.(2017)·8 citations
18. 18*

    Up- and down-quark contributions to the nucleon electromagnetic form factors at low $Q^2$

    I. A. Qattan🇦🇪 · J. Arrington🇺🇸

    The spatial distribution of charge and magnetization within the nucleon (proton and neutron) is encoded in the elastic electromagnetic form factors $G_E^{(p,n)}$ and $G_M^{(p,n)}$. These form factors have been precisely measured utilizing elastic electron scattering, and the combination of proton and neutron form factors allows for the separation of the up- and down-quark contributions to the nucleon form factors. We expand on our original analyses and extract the up- and down-quark contributions to the nucleon electromagnetic form factors from worldwide data with an emphasis on precise new data covering the low-momentum region, which is sensitive to the large-scale structure of the nucleon. From these, we construct the flavor-separated Dirac and Pauli form factors and their ratios, and compare the results to recent extractions and theoretical calculations and models.

    ↳ nucl-thhep-phJ.Phys.Conf.Ser.(2017)·17 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.