Tue·Nov 10, 2015Tuesday·November 10, 2015

1. 01*

   Instanton-dyon Ensemble with two Dynamical Quarks: the Chiral Symmetry Breaking

   Rasmus Larsen🇺🇸 · Edward Shuryak🇺🇸

   This is the second paper of the series aimed at understanding the ensemble of instanton-dyons, now with two flavors of light dynamical quarks. The partition function is appended by the fermionic factor, $(detT{)}^{N_f}$ and Dirac eigenvalue spectra at small values are derived from the numerical simulation of 64 and 128 dyons. Those spectra show clear chiral symmetry breaking pattern at high dyon density.

   hep-phhep-latnucl-thPRD(2016)·43 citations
2. 02*

   Understanding diboson anomalies

   Aqil Sajjad🇺🇸

   We conduct a model-independent effective theory analysis of hypercharged fields with various spin structures towards understanding the diboson excess found in LHC run I, as well as possible future anomalies involving $WZ$ and $WH$ modes. Within the assumption of no additional physics beyond the standard model up to the scale of the possible diboson resonance, we show that a hypercharged scalar and a spin 2 particle do not have tree-level $WZ$ and $WH$ decay channels up to dimension 5 operators, and cannot therefore account for the anomaly, whereas a hypercharged vector is a viable candidate provided we also introduce a $Z^{\prime }$ in order to satisfy electroweak precision constraints. We calculate bounds on the $Z^{\prime }$ mass consistent with the Atlas/CMS diboson signals as well as electroweak precision data, taking into account both LHC run I and II data.

   hep-phPRD(2016)·15 citations
3. 03*

   Production of Semi Quark Gluon Monopole Plasma by Glasma Decay

   Aiichi Iwazaki🇯🇵

   Using the standard Lagrangian of gluons and a model of dual superconductor for magnetic monopoles, we calculate the number densities of the gluons and monopoles produced by the decay of background color electric $E$ and magnetic $B$ fields ( glasma ). We find that gluons are dominant decay products when the initial values of the gauge fields are large such that $gE=gB>(0.5\text{mbox}GeV{)}^2$, while they are suppressed and monopoles are dominant decay products when the initial values are small such that $gE=gB<(0.4\text{mbox}GeV{)}^2$. The feature of the gluon dominance at large $gE=gB$ and the monopole dominance at small $gE=gB$ is similar to the one of thermalized quark gluon monopole plasmas proposed recently, if we identify $\sqrt{gE}=\sqrt{gB}$ as temperatures of the plasmas. Although the model of the monopoles is phenomenological, our analysis suggests that the monopoles play important roles in the decay of the glasmas with small saturation momenta, to which classical statistical field theories are not applicable.

   hep-phPRC(2016)·4 citations
4. 04*

   Impact of other scalar fields on oscillons after hilltop inflation

   Stefan Antusch🇨🇭 · Stefano Orani🇨🇭

   Oscillons are spatially localized and relatively stable field fluctuations which can form after inflation under suitable conditions. In order to reheat the universe, the fields which dominate the energy density after inflation have to couple to other degrees of freedom and finally produce the matter particles present in the universe today. In this study, we use lattice simulations in 2+1 dimensions to investigate how such couplings can affect the formation and stability of oscillons. We focus on models of hilltop inflation, where we have recently shown that hill crossing oscillons generically form, and consider the coupling to an additional scalar field which, depending on the value of the coupling parameter, can get resonantly enhanced from the inhomogeneous inflaton field. We find that three cases are realized: without a parametric resonance, the additional scalar field has no effects on the oscillons. For a fast and strong parametric resonance of the other scalar field, oscillons are strongly suppressed. For a delayed parametric resonance, on the other hand, the oscillons get imprinted on the other scalar field and their stability is even enhanced compared to the single-field oscillons.

   hep-phastro-ph.COhep-thJCAP(2016)·32 citations
5. 05*

   Probing the top-quark width through ratios of resonance contributions of $e^{+}{e}^{-}\to W^{+}{W}^{-}b\bar{b}$

   Stefan Liebler🇩🇪 · Gudrid Moortgat-Pick🇩🇪 · Andrew S. Papanastasiou🇬🇧

   We exploit offshell regions in the process $e^{+}{e}^{-}\to W^{+}{W}^{-}b\bar{b}$ to gain access to the top-quark width. Working at next-to-leading order in QCD we show that carefully selected ratios of offshell regions to onshell regions in the reconstructed top and antitop invariant mass spectra are, \emph{independently} of the coupling $g_{tbW}$, sensitive to the top-quark width. We explore this approach for different centre of mass energies and initial-state beam polarisations at $e^{+}{e}^{-}$ colliders and briefly comment on the applicability of this method for a measurement of the top-quark width at the LHC.

   hep-phJHEP(2016)·25 citations
6. 06*

   Fragmentation in the phi^3 Theory and the LPHD Hypothesis

   Karoly Urmossy🇭🇺 · Jan Rak🇫🇮

   We present analytic solution of the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) equation at leading order (LO) in the phi^3 theory in 6 space-time dimensions. If the phi^3 model was the theory of strong interactions, the obtained solution would describe the distribution of partons in a jet. We point out that the local parton-hadron duality (LPHD) conjecture does not work in this hypothetical situation. That is, treatment of hadronisation of shower partons is essential for the description of hadron distributions in jets stemming from proton-proton (pp) collisions at \sqrt{s} = 7 TeV and from electron-positron (e+e-) annihilations at various collision energies. We use a statistical model for the description of hadronisation.

   hep-phInt.J.Mod.Phys.A(2016)·0 citations
7. 07*

   Closing up a light stop window in natural SUSY at LHC

   Archil Kobakhidze🇦🇺 · Ning Liu🇨🇳 · Lei Wu🇦🇺 · Jin Min Yang🇨🇳 · Mengchao Zhang🇨🇳

   Top squark (stop) plays a key role in the radiative stability of the Higgs boson mass in supersymmetry (SUSY). The LHC searches for stop have made a great progress and tightly constrained the stop mass during Run-1. In this work, we use the LHC Run-1 data to determine the lower mass limit of the right-handed stop in a natural SUSY scenario, where the higgsinos ${\tilde{\chi }}_{1,2}^0$ and ${\tilde{\chi }}_1^{\pm }$ are light and nearly degenerate. We find that the stop mass has been excluded up to 430 GeV for $m_{{\tilde{\chi }}_1^0}\lesssim 250$ GeV and to 540 GeV for $m_{{\tilde{\chi }}_1^0}\simeq 100$ GeV by the Run-1 SUSY searches for $2b+E_T^{miss}$ and $1\ell +jets+E_T^{miss}$, respectively. In a small strip of parameter space with $m_{{\tilde{\chi }}_1^0}\gtrsim 190$ GeV, the stop mass can still be as light as 210 GeV and compatible with the Higgs mass measurement and the monojet bound. The 14 TeV LHC with a luminosity of 20 fb${}^{-1}$ can further cover such a light stop window by monojet and $2b+E_T^{miss}$ searches and push the lower bound of the stop mass to 710 GeV. We also explore the potential to use the Higgs golden ratio, $D_{\gamma \gamma }=\sigma (pp\to h\to \gamma \gamma )/\sigma (pp\to h\to Z{Z}^{\ast }\to 4{\ell }^{\pm })$, as a complementary probe for the light and compressed stop. If this golden ratio can be measured at percent level at the high luminosity LHC (HL-LHC) or future $e^{+}{e}^{-}$ colliders, the light stop can be excluded for most of the currently allowed parameter region.

   hep-phhep-exPLB(2016)·33 citations
8. 08*

   Comprehensive fits to high energy data for $\sigma$, $\rho$, and $B$ and the asymptotic black-disk limit

   Martin M. Block (Northwestern U.)🇺🇸 · Loyal Durand (Wisconsin U., Madison)🇺🇸 · Phuoc Ha (Towson U.)🇺🇸 · Francis Halzen (Wisconsin U., Madison)🇺🇸

   We demonstrate that the entirety of the data on proton--proton and antiproton--proton forward scattering between 6 GeV and 57 TeV center-of-mass energy is sufficient to show that ${\sigma }_{\mathrm{elas}}/{\sigma }_{\mathrm{tot}}\to 1/2$, and that $8\pi B/{\sigma }_{\mathrm{tot}}\to 1$ at very high energies, where $B$ the forward slope parameter for the differential elastic scattering cross sections. The relations demonstrate convincingly that the asymptotic $pp$ and $\bar{p}p$ scattering amplitudes approach those of scattering from a black disk. This result obviously has implications for any new physics that modifies the forward scattering amplitudes.

   hep-phPRD(2015)·25 citations
9. 09*

   Proximity of $f_0(1500)$ and $f_0(1710)$ to the scalar glueball

   Amir H. Fariborz🇺🇸 · Azizollah Azizi🇮🇷 · Abdorreza Asrar🇮🇷

   Within a nonlinear chiral Lagrangian framework, the underlying mixings among quark-antiquark, four-quark and glue components of $f_0(1500)$ and $f_0(1710)$ are studied in a global picture that includes all isosinglet scalar mesons below 2 GeV. The quark components are introduced in the Lagrangian in terms of two separate nonets (a quark-antiquark nonet and a four-quark nonet) which can mix with each other and with a scalar glueball. The free parameters of the Lagrangian are studied by a simultaneous fit to more than 20 experimental data and constraints on the mass spectrum, decay widths, and decay ratios of the isosinglet scalars below 2 GeV. Moreover, constraints on the mass spectrum and decay widths of isodoublet and isovector scalars below 2 GeV as well as pion-pion scattering amplitude are also taken into account. The insights gained in this global picture, due to the complexities of the mixings as well as the experimental uncertainties, are mainly qualitative but are relatively robust, and reveal that the lowest scalar glueball hides between $f_0(1500)$ and $f_0(1710)$, resulting in a considerable mixing with various quark components of these two states. The overall current experimental and theoretical uncertainties do not allow to pin down the exact glue components of isosinglet states, nevertheless it is shown that the $f_0(1500)$ and $f_0(1710)$ have the highest glue component. While this global study does not allow precision predictions for each individual state, it provides useful "family" correlations among the isosinglet states that are found insightful in probing the substructure of all scalars, in general, and the isosinglets, in particular. The overall estimate of the scalar glueball mass is found to be $1.58\pm 0.18$ GeV.

   hep-phhep-exhep-latnucl-thPRD(2015)·15 citations
10. 10*

    Octant Degeneracy, Quadrant of CPV phase at Long Baseline $\nu$ Experiments and Baryogenesis

    Kalpana Bora🇮🇳 · Gayatri Ghosh🇮🇳 · Debajyoti Dutta🇮🇳

    In a recent work by two of us, we have studied, how CP violation discovery potential can be improved at long baseline neutrino experiments (LBNE/DUNE), by combining with its ND (near detector) and reactor experiments. In this work, we discuss how this study can be further analyzed to resolve entanglement of the quadrant of leptonic CPV phase and Octant of atmospheric mixing angle ${\theta }_{23}$, at LBNEs. The study is done for both NH (Normal hierarchy) and IH (Inverted hierarchy), HO (Higher Octant) and LO (Lower Octant). We show how leptogenesis can enhance the effect of resolving this entanglement, and how possible values of the leptonic CPV phase can be predicted in this context. Carrying out numerical analysis based on the recent updated experimental results for neutrino mixing angles, we predict the values of the leptonic CPV phase for 152 possible cases. We also confront our predictions of the leptonic CPV phase with the updated global fit and find that five values of ${\delta }_{CP}$ are favoured by BAU constraints. One of the five values matches with the recent global fit value of ${\delta }_{CP}$ (leptonic CPV phase) close to 1.41 $\pi$ in our model independent scenario. A detailed analytic and numerical study of baryogenesis through leptogenesis is performed in this framework in a model independent way.

    hep-ph2 citations
11. 11*

    Hadronic deuteron polarizability contribution to the Lamb shift in muonic deuterium

    A.V. Eskin🇷🇺 · R.N. Faustov🇷🇺 · A.P. Martynenko🇷🇺 · F.A. Martynenko🇷🇺

    Hadronic deuteron polarizability correction to the Lamb shift of muonic deuterium is calculated on the basis of unitary isobar model and modern experimental data on the structure functions of deep inelastic lepton-deuteron scattering and their parameterizations in the resonance and nonresonance regions.

    hep-phquant-phMod.Phys.Lett.A(2016)·4 citations
12. 12*

    Form factors in $B\to \pi \pi \ell {\bar{\nu }}_{\ell }$ from QCD light-cone sum rules

    Christian Hambrock🇩🇪 · Alexander Khodjamirian🇩🇪

    The form factors of the semileptonic $B\to \pi \pi \ell \bar{\nu }$ decay are calculated from QCD light-cone sum rules with the distribution amplitudes of dipion states. This method is valid in the kinematical region, where the hadronic dipion state has a small invariant mass and simultaneously a large recoil. The derivation of the sum rules is complicated by the presence of an additional variable related to the angle between the two pions. In particular, we realize that not all invariant amplitudes in the underlying correlation function can be used, some of them generating kinematical singularities in the dispersion relation. The two sum rules that are free from these ambiguities are obtained in the leading twist-2 approximation, predicting the ${\bar{B}}^0\to {\pi }^{+}{\pi }^0$ form factors $F_{\perp }$ and $F_{\parallel }$ of the vector and axial $b\to u$ current, respectively. We calculate these form factors at the momentum transfers $0<q^2\lesssim 12$ GeV${}^2$ and at the dipion mass close to the threshold $4m_{\pi }^2$. The sum rule results indicate that the contributions of the higher partial waves to the form factors are suppressed with respect to the lowest $P$-wave contribution and that the latter is not completely saturated by the $\rho$-meson term.

    hep-phNPB(2016)·50 citations
13. 13*

    Dark Matter from the vector of SO(10)

    Sofiane M. Boucenna🇮🇹 · Martin B. Krauss🇮🇹 · Enrico Nardi🇮🇹

    SO(10) grand unified theories can ensure the stability of new particles in terms of the gauge group structure itself, and in this respect are well suited to accommodate dark matter (DM) candidates in the form of new stable massive particles. We introduce new fermions in two vector 10 representations. When SO(10) is broken to the standard model by a minimal 45 + 126 + 10 scalar sector with $SU(3{)}_C\otimes SU(2{)}_L\otimes SU(2{)}_R\otimes U(1{)}_{B-L}$ as intermediate symmetry group, the resulting lightest new states are two Dirac fermions corresponding to combinations of the neutral members of the $SU(2{)}_L$ doublets in the 10's, which get splitted in mass by loop corrections involving $W_R$. The resulting lighter mass eigenstate is stable, and has only non-diagonal $Z_{L,R}$ neutral current couplings to the heavier neutral state. Direct detection searches are evaded if the mass splitting is sufficiently large to suppress kinematically inelastic light-to-heavy scatterings. By requiring that this condition is satisfied, we obtain the upper limit $M_{W_R}\lesssim 25$ TeV.

    hep-phPLB(2016)·37 citations
14. 14*

    Asymptotic Safety in the Conformal Hidden Sector?

    Zhi-Wei Wang🇨🇦 · Frederick S. Sage🇨🇦 · T.G. Steele🇨🇦 · R.B. Mann🇨🇦

    We combine the notion of asymptotic safety (AS) with conformal invariance in a hidden sector beyond the Standard Model. We use the renormalization group (RG) equations as a bridge to connect UV boundary conditions and EW/TeV scale physics and furnish a detailed example in the context of a leptophobic $U(1{)}^{\prime }$ model. A broad selection of UV boundary conditions are formulated corresponding to differing AS scenarios, and we find an AS scenario with very strong predictive power, allowing unique determination of most of the parameters in the model. We obtain the interrelationships among the couplings, the transition scale of the fixed point $M_{UV}$ and the generations of quarks coupled to the $Z^{\prime }$, and especially the correlation between $M_{UV}$ and the top quark Yukawa coupling $Y_t$. Several phenomenological implications of our results are presented for selected $Z^{\prime }$ masses.

    hep-phJ.Phys.G(2018)·37 citations
15. 15*

    The cool potential of gluons

    Andre Peshier🇿🇦 · Dino Giovannoni🇿🇦

    We put forward the idea that the quark-gluon plasma might exist way below the usual confinement temperature $T_c$. Our argument rests on the possibility that the plasma produced in heavy-ion collisions could reach a transient quasi-equilibrium with `over-occupied' gluon density, as advocated by Blaizot et al. Taking further into account that gluons acquire an effective mass by interaction effects, they can have a positive chemical potential and therefore behave similarly to non-relativistic bosons. Relevant properties of this dense state of interacting gluons, which we dub serried glue, can then be inferred on rather general grounds from Maxwell's relation.

    hep-phJ.Phys.Conf.Ser.(2016)·5 citations
16. 16*

    Debye mass of massless \phi^4-theory to order g^6 at weak coupling

    Rashid Khan

    We calculate the Debye mass of massless \phi^4-theory to order g^6 at weak coupling. The contributions to the Debye mass arise from the hard momentum scale of order T and the soft momentum scale of order gT. Effective field theory methods and dimensional reduction are used to separate the contributions from the two momentum scales. The hard contribution can be calculated as a power series in g^2 using naive perturbation theory with bare propagators. The soft contribution is calculated using an effective theory in three dimensions, whose coefficients are power series in g^2. This contribution is a power series in g starting at order g^3. The calculation of the hard part to order g^6. The calculation of the soft part requires calculating the mass parameter in the effective theory to order g^6 and the evaluation of four-loop self-energy diagrams in three dimensions. This gives the Debye mass correct up to order g^6. We discuss the convergence of the perturbative series as well as the loop expansion in three dimensions which implies a selective resummation of higher-order terms.

    hep-phhep-thInt.J.Theor.Phys.(2020)·0 citations
17. 17*

    Neutrino-Nucleon Cross section in Ultra High Energy Regime

    Kalpana Bora🇮🇳 · Neelakshi Sarma🇮🇳

    Neutrino Physics is now entering precision era and neutrino-nucleon cross sections are an im- portant ingredient in all neutrino oscillation experiments. Specially, precise knowledge of neutrino- nucleon cross sections in Ultra High Energy (UHE) regime (TeV-PeV) is becoming more important now, as several experiments worldwide are going to observe processes involving such UHE neutrinos. In this work, we present new results on neutrino-nucleon cross-sections in this UHE regime, using QCD.

    hep-phSpringer Proc.Phys.(2016)·3 citations
18. 18*

    SO(10) models with flavour symmetries: Classification and examples

    I. P. Ivanov🇵🇹 · L. Lavoura🇵🇹

    We establish the full list of flavour symmetry groups which may be enforced, without producing any further accidental symmetry, on the Yukawa-coupling matrices of an SO(10) Grand Unified Theory with arbitrary numbers of scalar multiplets in the 10, $\overline{126}$, and 120 representations of SO(10). For each of the possible discrete non-Abelian symmetry groups, we present examples of minimal models which do not run into obvious contradiction with the phenomenological fermion masses and mixings.

    hep-phJ.Phys.G(2016)·12 citations
19. 19*

    Realization of chiral symmetry breaking and restoration in holographic QCD

    Kaddour Chelabi🇨🇳 · Zhen Fang🇨🇳 · Mei Huang🇨🇳 · Danning Li🇨🇳 · Yue-Liang Wu🇨🇳

    With proper profiles of the scalar potential and the dilaton field, for the first time, the spontaneous chiral symmetry breaking in the vacuum and its restoration at finite temperature are correctly realized in the holographic QCD framework. In the chiral limit, a nonzero chiral condensate develops in the vacuum and decreases with temperature, and the phase transition is of 2nd order for two-flavor case and of 1st order for three-flavor case. In the case of explicit chiral symmetry breaking, in two-flavor case, the 2nd order phase transition turns to crossover with any nonzero current quark mass, and in three-flavor case, the 1st order phase transition turns to crossover at a finite current quark mass. The correct description of chiral symmetry breaking and restoration makes the holographic QCD models more powerful in dealing with non-perturbative QCD phenomena. This framework can be regarded as a general set up in application of AdS/CFT to describe conventional Ginzburg-Landau-Wilson type phase transitions, e.g. in condensed matter and cosmology systems.

    hep-phhep-lathep-thPRD(2016)·74 citations
20. 20*

    Discovering New Physics with Voronoi Tessellations

    Dipsikha Debnath🇺🇸 · James S. Gainer🇺🇸 · Doojin Kim🇺🇸 · Konstantin T. Matchev🇺🇸

    High energy experimental data can be viewed as a sampling of the relevant phase space. We point out that one can apply Voronoi tessellations in order to understand the underlying probability distributions in this phase space. Interesting features in the data can then be discovered by studying the properties of the ensemble of Voronoi cells. For illustration, we demonstrate the detection of kinematic "edges" in two dimensions, which may signal physics beyond the standard model. We motivate the algorithm with some analytical results derived for perfect lattices, and show that the method is further improved with the addition of a few Voronoi relaxation steps via Lloyd's method.

    hep-phhep-ex5 citations
21. 21*

    Group-theoretic restrictions on generation of CP-violation in multi-Higgs-doublet models

    G. C. Branco🇵🇹 · I. P. Ivanov🇵🇹

    It has been known since decades that imposing a symmetry group G on the scalar sector of multi-Higgs-doublet models has consequences for CP-violation. In all examples of two- and three-Higgs-doublet models equipped with symmetries, one observes the following intriguing property: if G prevents explicit CP-violation (CPV), at least in the neutral Higgs sector, then it also prevents spontaneous CPV, and if G allows explicit CPV, then it allows for spontaneous CPV. One is led to conjecture that this is a general phenomenon. In this paper, we prove this conjecture for any rephasing symmetry group G and any number of doublets.

    hep-phJHEP(2016)·15 citations
22. 22*

    Diffractive production of jets at high-energy in the QCD shock-wave approach

    R. Boussarie🇫🇷 · A. V. Grabovsky🇷🇺 · L. Szymanowski🇵🇱 · S. Wallon🇫🇷

    In view of future phenomenological applications, we study the impact factor for the photon to quark, antiquark and gluon transition within Balitsky's shock-wave formalism. The aim of the present program is to extend existing results beyond approximations discussed in the literature. We present our results of the real contribution, and report on recent progress in calculating the virtual contributions for the photon to quark, antiquark transition.

    hep-ph3 citations
23. 23*

    Alternative search strategies for a BSM resonance fitting ATLAS diboson excess

    Biplob Bhattacherjee🇮🇳 · Pritibhajan Byakti🇮🇳 · Charanjit K. Khosa🇮🇳 · Jayita Lahiri🇮🇳 · Gaurav Mendiratta🇮🇳

    We study an s-channel resonance $R$ as a viable candidate to fit the diboson excess reported by ATLAS. We compute the contribution of the $\sim 2$ TeV resonance $R$ to semileptonic and leptonic final states at 13 TeV LHC. To explain the absence of an excess in semileptonic channel, we explore the possibility where the particle $R$ decays to additional light scalars $X,X$ or $X,Y$. Modified analysis strategy has been proposed to study three particle final state of the resonance decay and to identify decay channels of $X$. Associated production of $R$ with gauge bosons has been studied in detail to identify the production mechanism of $R$. We construct comprehensive categories for vector and scalar BSM particles which may play the role of particles $R$, $X$, $Y$ and find alternate channels to fix the new couplings and search for these particles.

    hep-phhep-exPRD(2016)·9 citations
24. 24*

    Proposal to Search for Magnetically Charged Particles with Magnetic Charge 1e

    Michael K. Sullivan🇺🇸 · David Fryberger🇺🇸

    A model for composite elementary Standard Model (SM) particles based upon magnetically bound vorton pairs, briefly introduced here, predicts the existence of a complete family of magnetically charged particles, as well as their neutral isotopic partners (all counterparts to the SM elementary particles), in which the lowest mass (charged) particle would be an electrically neutral stable lepton, but which carries a magnetic charge equivalent to 1e. This new particle, which we call a magneticon (a counterpart to the electron) would be pair produced at all e+e- colliders at an Ecm above twice its mass. In addition, PP and PPbar colliders should also be able to produce these new particles through the Drell-Yan process. To our knowledge, no monopole search experiment has been sensitive to such a low-charged magnetic monopole above a particle mass of about 5 GeV/c2. Hence, we propose that a search for such a stable particle of magnetic charge 1e should be undertaken. We have taken the ATLAS detector at the LHC as an example in which this search might be done. To this end, we have modeled the magnetic fields and muon trigger chambers of this detector. We show results from a simple Monte Carlo simulation program to indicate how these particles might look in the detector and describe how one might search for these new particles in the ATLAS data stream.

    ↳ hep-exhep-ph2 citations
25. 25*

    Operator analysis of effective spin-flavor interactions for L=1 excited baryons

    Cintia Willemyns🇦🇷 · Carlos Schat🇦🇷

    We match the non-relativistic quark model, with both flavor dependent and flavor independent effective quark-quark interactions, to the spin-flavor operator basis of the 1/Nc expansion for the L=1 non-strange baryons. We obtain analytic expressions for the coefficients of the 1/Nc operators in terms of radial integrals that depend on the shape and relative strength of the spin-spin, spin-orbit and tensor interactions of the model, which are left unspecified. We obtain several new, parameter-free relations between the seven masses and the two mixing angles that can discriminate between different spin-flavor structures of the effective quark-quark interaction. We discuss in detail how a general parametrization of the mass matrix depends on the mixing angles and is constrained by the assumptions on the effective quark-quark interaction. We find that, within the present experimental uncertainties, consistency with the best values of the mixing angles as determined by a recent global fit to masses and decays does not exclude any of the two most extreme possibilities of flavor dependent (independent) quark-quark interactions, as generated by meson (gluon) exchange interactions.

    ↳ nucl-thhep-phPRD(2016)·6 citations
26. 26*

    Nuclear Parity Violation from Lattice QCD

    Thorsten Kurth · Evan Berkowitz · Enrico Rinaldi · Pavlos Vranas · Amy Nicholson · Mark Strother · Andre Walker-Loud

    The electroweak interaction at the level of quarks and gluons are well understood from precision measurements in high energy collider experiments. Relating these fundamental parameters to Hadronic Parity Violation in nuclei however remains an outstanding theoretical challenge. One of the most interesting observables in this respect is the parity violating hadronic neutral current: it is hard to measure in collider experiments and is thus the least constrained observable of the Standard Model. Precision measurements of parity violating transitions in nuclei can help to improve these constraints. In these systems however, the weak interaction is masked by effects of the seven orders of magnitude stronger non-perturbative strong interaction. Therefore, in order to relate experimental measurements of the parity violating pion-nucleon couplings to the fundamental Lagrangian of the SM, these non-perturbative effects have to be well understood. In this paper, we are going to present a Lattice QCD approach for computing the $\Delta I=2$ parity violating matrix element in proton proton scattering. This process does not involve disconnected diagrams in the isospin symmetric limit and is thus a perfect testbed for studying the feasibility of the more involved calculation of the parity violating pion-nucleon coupling.

    ↳ hep-lathep-phnucl-thPoS(2016)·14 citations
27. 27*

    Baikal-GVD: first cluster Dubna

    A.D. Avrorin🇷🇺 · A.V. Avrorin🇷🇺 · V.M. Aynutdinov🇷🇺 · R. Bannash · I.A. Belolaptikov🇷🇺 · D.Yu. Bogorodsky🇷🇺 · V.B. Brudanin🇷🇺 · N.M. Budnev🇷🇺 · I.A. Danilchenko🇷🇺 · S.V. Demidov🇷🇺 · G.V. Domogatsky🇷🇺 · A.A. Doroshenko🇷🇺 and 38 other authors

    In April 2015 the demonstration cluster "Dubna" was deployed and started to take data in Lake Baikal. This array is the first cluster of the cubic kilometer scale Gigaton Volume Detector (Baikal-GVD), which is constructed in Lake Baikal. In this contribution we will review the design and status of the array.

    ↳ physics.ins-dethep-exhep-phPoS(2015)·7 citations
28. 28*

    Evaluation of conformal integrals

    Adam Bzowski🇧🇪 · Paul McFadden🇬🇧 · Kostas Skenderis🇬🇧

    We present a comprehensive method for the evaluation of a vast class of integrals representing 3-point functions of conformal field theories in momentum space. The method leads to analytic, closed-form expressions for all scalar and tensorial 3-point functions of operators with integer dimensions in any spacetime dimension. In particular, this encompasses all 3-point functions of the stress tensor, conserved currents and marginal scalar operators.

    ↳ hep-thhep-phmath-phmath.MPJHEP(2016)·80 citations
29. 29*

    Search for nucleon-nucleon correlations in neutrino-argon scattering

    Kajetan Niewczas🇵🇱 · Jan T. Sobczyk🇵🇱

    A sample of two proton and no pion events selected in the ArgoNeuT neutrino scattering experiment on liquid argon target [Phys. Rev. D90 (2014) 012008] is analyzed with NuWro Monte Carlo event generator. An attempt is made to estimate how likely it is to obtain observed numbers of laboratory frame and reconstructed back-to-back nucleon pairs. For laboratory frame back-to-back events a clear data/MC discrepancy is seen. For the reconstructed nucleon pairs a good agreement is reported. We provide a simple kinematical argument why this accordance is expected.

    ↳ hep-exhep-phPRC(2016)·16 citations
30. 30*

    Observables and initial conditions for rotating and expanding fireballs with spheroidal symmetry

    T. Csorgo🇭🇺 · M.I. Nagy🇭🇺 · I. F. Barna🇭🇺

    Utilizing a recently found class of exact, analytic rotating solutions of non-relativistic fireball hydrodynamics, we calculate analytically the single-particle spectra, the elliptic flows and two-particle Bose-Einstein correlation functions for rotating and expanding fireballs with spheroidal symmetry. We demonstrate, that rotation generates final state momentum anisotropies even for a spatially symmetric, spherical initial geometry of the fireball. The mass dependence of the effective temperatures, as well as the HBT radius parameters and the elliptic flow are shown to be sensitive not only to radial flow effects but also to the magnitude of the initial angular momentum.

    ↳ nucl-thhep-exhep-phnucl-exPRC(2016)·12 citations
31. 31*

    Galactic dark matter search via phenomenological astrophysics modeling

    Xiaoyuan Huang🇩🇪 · Torsten Enßlin🇩🇪 · Marco Selig🇩🇪

    Previous searches for the $\gamma$-ray signatures of annihilating galactic dark matter used predefined spatial templates to describe the background of $\gamma$-ray emission from astrophysical processes like cosmic ray interactions. In this work, we aim to establish an alternative approach, in which the astrophysical components are identified solely by their spectral and morphological properties. To this end, we adopt the recent reconstruction of the diffuse $\gamma$-ray sky from Fermi data by the D${}^3$PO algorithm and the fact that more than 90\% of its flux can be represented by only two spectral components, resulting form the dense and dilute interstellar medium. Under these presumptions, we confirm the reported DM annihilation-like signal in the inner Galaxy and derive upper limits for dark matter annihilation cross sections. We investigate whether the DM signal could be a residual of the simplified modeling of astrophysical emission by inspecting the morphology of the regions, which favor a dark matter component. The central galactic region favors strongest for such a component with the expected spherically symmetric and radially declining profile. However, astrophysical structures, in particular sky regions which seem to host most of the dilute interstellar medium, obviously would benefit from a DM annihilation-like component as well. Although these regions do not drive the fit, they warn that a more detailed understanding of astrophysical $\gamma$-ray emitting processes in the galactic center region are necessary before definite claims about a DM annihilation signal can be made. The regions off the Galactic plane actually disfavor the best fit DM annihilation cross section from the inner Galactic region unless the radial decline of the Galactic DM density profile in the outer regions is significantly steeper than that usually assumed.

    ↳ astro-ph.HEastro-ph.COhep-phJCAP(2016)·50 citations
32. 32*

    Impacts of dark energy on weighing neutrinos after Planck 2015

    Xin Zhang🇺🇸

    We investigate how dark energy properties impact the cosmological limits on the total mass of active neutrinos. We consider two typical, simple dark energy models (that have only one more additional parameter than $\Lambda$CDM), i.e., the $w$CDM model and the holographic dark energy (HDE) model, as examples, to make an analysis. In the cosmological fits, we use the Planck 2015 temperature and polarization data, in combination with other low-redshift observations, including the baryon acoustic oscillations, type Ia supernovae, and Hubble constant measurement, as well as the Planck lensing measurements. We find that, once dynamical dark energy is considered, the degeneracy between $\sum m_{\nu }$ and $H_0$ will be changed, i.e., in the $\Lambda$CDM model, $\sum m_{\nu }$ is anti-correlated with $H_0$, but in the $w$CDM and HDE models, $\sum m_{\nu }$ becomes positively correlated with $H_0$. Compared to $\Lambda$CDM, in the $w$CDM model the limit on $\sum m_{\nu }$ becomes much looser, but in the HDE model the limit becomes much tighter. In the HDE model, we obtain $\sum m_{\nu }<0.113$ eV ($95\%$ CL) with the combined data sets, which is perhaps the most stringent upper limit by far on neutrino mass. Thus, our result in the HDE model is nearly ready to diagnose the neutrino mass hierarchy with the current cosmological observations.

    ↳ astro-ph.COgr-qchep-phPRD(2016)·80 citations
33. 33*

    Identification of the ~3.55 keV emission line candidate objects across the sky

    Denys Savchenko🇺🇦 · Dmytro Iakubovskyi🇺🇦

    Emission line at the energy ~3.55 keV detected in different galaxies and galaxy clusters has caused a lot of discussion in high-energy astrophysics and particle physics communities. To reveal the origin of the line, we analyzed publicly available observations of MOS cameras from XMM-Newton cosmic observatory - the instrument with the largest sensitivity for narrow faint X-ray lines - previously combined in X-ray sky maps. Because of extremely large timescale needed for detailed analysis, we used the wavelet method instead. Extensive simulations of the central part of Andromeda galaxy are used to check the validity of this method. The resulting list of wavelet detections now contains 235 sky regions. This list will be used in future works for more detailed spectral analysis.

    ↳ astro-ph.HEastro-ph.COastro-ph.IMhep-ph1 citation
34. 34*

    Stringy N = 1 super no-scale models

    Costas Kounnas🇫🇷 · Herve Partouche🇫🇷

    N=1 no-scale models describe at tree level the spontaneous breaking of supersymmetry at an arbitrary scale m_{3/2}, with vanishing vacuum energy. We define N=1 super no-scale models in string theory as being those, which maintain these properties at 1-loop. In other words, in super no-scale models, m_{3/2} is a flat direction of a positive semi-definite 1-loop effective potential. We find explicit examples in heterotic Z_2 x Z_2 orbifold models, where N=1 is spontaneously broken by a stringy Scherk-Schwarz mechanism, and where the "decompactification problem" does not arise.

    ↳ hep-thgr-qchep-phPoS(2015)·22 citations
35. 35*

    From topological to non-topological solitons: kinks, domain walls and Q-balls in a scalar field model with non-trivial vacuum manifold

    Yves Brihaye🇧🇪 · Adolfo Cisterna🇨🇱 · Betti Hartmann🇧🇷 · Gabriel Luchini🇧🇷

    We consider a scalar field model with a self-interaction potential that possesses a discrete vacuum manifold. We point out that this model allows for both topological as well as non-topological solitons. In (1+1) dimensions both type of solutions have finite energy, while in (3+1) dimensions, the topological solitons have finite energy per unit area only and correspond to domain walls. Non-topological solitons with finite energy do exist in (3+1) dimensions due to a non-trivial phase of the scalar field and an associated U(1) symmetry of the model, though. We construct these so-called Q-ball solutions numerically, point out the differences to previous studies with different scalar field potentials and also discuss the influence of a minimal coupling to both gravity as well as a U(1) gauge field. In this latter case, the conserved Noether charge Q can be interpreted as the electric charge of the solution.

    ↳ hep-thgr-qchep-phPRD(2015)·27 citations
36. 36*

    Conditions on the violation of the cluster decomposition property in QCD

    Peter Lowdon🇨🇭

    The behaviour of correlators at large distances plays an important role in the dynamics of quantum field theories. In many instances, correlators satisfy the so-called \textit{cluster decomposition property} (CDP), which means that they tend to zero for space-like asymptotic distances. However, under certain conditions it is possible for correlators to violate this property. In the context of quantum chromodynamics (QCD), a violation of the CDP for correlators of clusters involving coloured fields implies that the strength of the correlations between the coloured degrees of freedom in these clusters increases at large distances, which is a sufficient condition for confinement. In this paper we establish a criterion for when the CDP is violated. By applying this criterion to QCD, it turns out that certain lattice results involving the quark and gluon propagators can be interpreted as evidence that quarks and gluons are confined due to a violation of the CDP.

    ↳ hep-thhep-lathep-phJ.Math.Phys.(2016)·24 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.