Tue·Sep 29, 2015Tuesday·September 29, 2015

1. 01*

   High-order threshold corrections for top-pair and single-top production

   Nikolaos Kidonakis🇺🇸

   I present results for high-order corrections from threshold resummation to cross sections and differential distributions in top-antitop pair production and in single-top production. I show aN${}^3$LO results for the total $t\bar{t}$ cross section as well as for the top-quark transverse momentum ($p_T$) and rapidity distributions, and the top-quark forward-backward asymmetry in $t\bar{t}$ production. I compare with the most recent Tevatron and LHC data, including at 13 TeV. I also present aNNLO results for cross sections and $p_T$ distributions in $t$-channel, $s$-channel, and $tW$-channel single-top production.

   hep-ph9 citations
2. 02*

   A note on the fate of the Landau-Yang theorem in non-Abelian gauge theories

   Matteo Cacciari🇫🇷 · Luigi Del Debbio🇬🇧 · José R. Espinosa🇪🇸 · Antonio D. Polosa🇮🇹 · Massimo Testa🇮🇹

   Using elementary considerations of Lorentz invariance, Bose symmetry and BRST invariance, we argue why the decay of a massive color-octet vector state into a pair of on-shell massless gluons is possible in a non-Abelian SU(N) Yang-Mills theory, we constrain the form of the amplitude of the process and offer a simple understanding of these results in terms of effective-action operators.

   hep-phhep-thPLB(2016)·31 citations
3. 03*

   Constraints on Majorana Dark Matter from the LHC and IceCube

   Jan Heisig🇩🇪 · Michael Krämer🇩🇪 · Mathieu Pellen🇩🇪 · Christopher Wiebusch🇩🇪

   We consider a simplified model for Majorana fermion dark matter and explore constraints from direct, indirect and LHC collider searches. The dark matter is assumed to couple to the Standard Model through a vector mediator with axial-vector interactions. We provide detailed analyses of LHC mono-jet searches and IceCube limits on dark matter annihilation in the Sun. In particular, we develop a method for calculating limits on simplified WIMP dark matter models from public IceCube data, which are only available for a limited number of Standard Model final states. We demonstrate that LHC and IceCube searches for Majorana dark matter are complementary and derive new limits on the dark matter and mediator masses, including in addition constraints from LHC di-jet searches, direct detection and the dark matter relic density.

   hep-phastro-ph.HEPRD(2016)·26 citations
4. 04*

   Searching for Standard Model Adjoint Scalars with Diboson Resonance Signatures

   Linda M. Carpenter🇺🇸 · Russell Colburn🇺🇸

   We explore the phenomenology of scalar fields in the adjoint representation of SM gauge groups. We write a general set of dimension 5 effective operators in which SM adjoint scalars couple to pairs of standard model bosons. Using these effective operators, we explore new possible decay channels of a scalar color octet into a gluon and a Z boson/ gluon and a photon. We recast several analyses from Run I of the LHC to find constraints on an a scalar octet decaying into these channels, and we project the discovery potential of color octets in our gluon+photon channel for the 14 TeV run of LHC.

   hep-phJHEP(2015)·18 citations
5. 05*

   Light Leptonic New Physics at the Precision Frontier

   Matthias Le Dall🇨🇦

   Precision probes of new physics are often interpreted through their indirect sensitivity to short-distance scales. In this proceedings contribution, we focus on the question of which precision observables, at current sensitivity levels, allow for an interpretation via either short-distance new physics or consistent models of long-distance new physics, weakly coupled to the Standard Model. The electroweak scale is chosen to set the dividing line between these scenarios. In particular, we find that inverse see-saw models of neutrino mass allow for light new physics interpretations of most precision leptonic observables, such as lepton universality, lepton flavor violation, but not for the electron EDM.

   hep-phAIP Conf.Proc.(2016)·0 citations
6. 06*

   Fragmentation contributions to hadroproduction of prompt $J/\psi$, ${\chi }_{cJ}$, and $\psi (2S)$ states

   Geoffrey T. Bodwin🇺🇸 · Kuang-Ta Chao🇨🇳 · Hee Sok Chung🇺🇸 · U-Rae Kim🇰🇷 · Jungil Lee🇰🇷 · Yan-Qing Ma🇨🇳

   We compute fragmentation corrections to hadroproduction of the quarkonium states $J/\psi$, ${\chi }_{cJ}$, and $\psi (2S)$ at leading power in $m_c^2/p_T^2$, where $m_c$ is the charm-quark mass and $p_T$ is the quarkonium transverse momentum. The computation is carried out in the framework of nonrelativistic QCD. We include corrections to the parton-production cross sections through next-to-leading order in the strong coupling ${\alpha }_s$ and corrections to the fragmentation functions through second order in ${\alpha }_s$. We also sum leading logarithms of $p_T^2/m_c^2$ to all orders in perturbation theory. We find that, when we combine these leading-power fragmentation corrections with fixed-order calculations through next-to-leading order in ${\alpha }_s$, we are able to obtain good fits for $p_T\ge 10$ GeV to hadroproduction cross sections that were measured at the Tevatron and the LHC. Using values for the nonperturbative long-distance matrix elements that we extract from the cross-section fits, we make predictions for the polarizations of the quarkonium states. We obtain good agreement with measurements of the polarizations, with the exception of the CDF Run II measurement of the prompt $J/\psi$ polarization, for which the agreement is only fair. In the predictions for the prompt-$J/\psi$ cross sections and polarizations, we take into account feeddown from the ${\chi }_{cJ}$ and $\psi (2S)$ states.

   hep-phPRD(2016)·114 citations
7. 07*

   Reconciling Muon g-2, 125 GeV Higgs and Dark Matter in Gauge Mediation Models

   Ilia Gogoladze🇺🇸 · Qaisar Shafi🇺🇸 · Cem Salih Un🇹🇷

   We present a class of models in the framework of gauge mediation supersymmetry breaking where the standard model is supplemented by additional U(1) symmetry which acts only on the third generation fermions. The messenger fields carry non-trivial U(1) charge and are vector-like particles under this symmetry. This leads to additional contribution to the soft supersymmetry breaking mass terms for the third generation squarks and sleptons. In this framework we show that the muon g-2 anomaly, the observed 125 GeV Higgs boson mass and the detected relic dark matter abundance (gravitino in our case) can be simultaneously accommodated. The resolution of the muon g-2 anomaly, in particular, yields the result that the first two generation squark masses, as well the gluino mass, should be <~ 2.5 TeV, which will be tested at LHC14.

   hep-phPRD(2015)·21 citations
8. 08*

   Spin one matter fields

   M. Napsuciale🇲🇽 · S. Rodríguez🇲🇽 · Rodolfo Ferro-Hernández🇲🇽 · Selim Gómez-Ávila🇲🇽

   Spin-one matter fields are relevant both for the description of hadronic states and as potential extensions of the Standard Model. In this work we present a formalism for the description of massive spin-one fields transforming in the $(1,0)\oplus (0,1)$ representation of the Lorentz group, based on the covariant projection onto parity eigenspaces and Poincaré orbits. The formalism yields a constrained dynamics. We solve the constraints and perform the canonical quantization accordingly. This formulation uses the recent construction of a parity-based covariant basis for matrix operators acting on the $(j,0)\oplus (0,j)$ representations. The algebraic properties of the covariant basis play an important role in solving the constraints and allowing the canonical quantization of the theory. We study the chiral structure of the theory and conclude that it is not chirally symmetric in the massless limit, hence it is not possible to have chiral gauge interactions. However, spin-one matter fields can have vector gauge interactions. Also, the dimension of the field makes self-interactions naively renormalizable. Using the covariant basis, we classify all possible naively renormalizable self-interaction terms.

   hep-phPRD(2016)·10 citations
9. 09*

   The Drell-Yan process as a testing ground for parton distributions up to LHC

   Eduardo Basso🇸🇪 · Claude Bourrely🇫🇷 · Roman Pasechnik🇸🇪 · Jacques Soffer🇺🇸

   The Drell-Yan massive dilepton production in hadron-hadron collisions provides a unique tool, complementary to Deep Inelastic Scattering, for improving our understanding of hadronic substructure and in particular for testing parton distributions. We will consider measurements of the differential and double-differential Drell-Yan cross sections from FNAL Tevatron up to CERN LHC energies and they will be compared to the predictions of perturbative QCD calculations using most recent sets (CT14 and MMHT14) of parton distribution functions, as well as those provided by the statistical approach.

   hep-phNPA(2016)·20 citations
10. 10*

    Flavored axion-monodromy inflation

    Christopher D. Carone🇺🇸 · Raymundo Ramos🇺🇸 · Zhen Wang🇺🇸

    The hierarchy of fermion masses in the standard model may arise via the breaking of discrete gauge symmetries. The renormalizable interactions of the flavor-symmetry-breaking potential can have accidental global symmetries that are spontaneously broken, leading to pseudo-goldstone bosons that may drive inflation. We consider two-field, axion-monodromy inflation models in which the inflaton is identified with a linear combination of pseudo-goldstone bosons of the flavor sector. We show that the resulting models are nontrivially constrained by current cosmological data as well as the requirements of viable flavor model building.

    hep-phPRD(2015)·1 citation
11. 11*

    One-loop matching for transversity generalized parton distribution

    Xiaonu Xiong🇮🇹 · Jian-Hui Zhang🇩🇪

    Recent developments showed that light cone parton distributions can be studied by investigating the large momentum limit of the so-called quasiparton distributions, which are defined in terms of spacelike correlators, and therefore can be readily computed on the lattice. These two distributions can be connected to each other by a perturbative factorization formula or matching condition that allows one to convert the latter into the former. Here we present the one-loop matching condition for the transversity generalized quark distribution in the nonsinglet case

    hep-phPRD(2015)·93 citations
12. 12*

    Peculiar seasonal effects in the neutrino day-night asymmetry

    Oleg G. Kharlanov🇷🇺

    We analyze peculiar effects in the day-night asymmetry of solar neutrinos taking place due to their continuous observation during the night and/or the year. Namely, we show that the day-night effect contains both a trivial, cumulative contribution from the whole observation term and a number of localized terms originating from around the midnights (during the nights) and the two solstices (during the year). We estimate the latter contributions using asymptotical methods and discuss the prospects of their isolation, i.e., magnification, by contraction of the neutrino observation term to small neighborhoods of the localization points. In order to complement our asymptotical predictions derived analytically, we also perform a full numerical analysis of a temporally-weighted observation of the day-night effect, including the energy spectrum of the day-night asymmetry and an estimation of the recoil energy distributions for the elastic-scattering detection channel. According to both analytical and numerical results, it turns out that a weighted observation is able to magnify the amplitude of the peculiar contribution to the day-night asymmetry even to as much as several times the cumulative term, and it looks feasible and appealing to perform such a weighting procedure at next-generation detectors to revive otherwise hidden signatures of the neutrino regeneration effect in the Earth.

    hep-ph3 citations
13. 13*

    Role of the $f_1(1285)$ state in the $J/\psi \to \varphi \bar{K}{K}^{\ast }$ and $J/\psi \to \varphi f_1(1285)$ decays

    Ju-Jun Xie🇨🇳 · E. Oset🇪🇸

    We study the role of the $f_1(1285)$ resonance in the decays of $J/\psi \to \varphi \bar{K}{K}^{\ast }$ and $J/\psi \to \varphi f_1(1285)$. The theoretical approach is based on the results of chiral unitary theory where the $f_1(1285)$ resonance is dynamically generated from the $K^{\ast }\bar{K}-c.c.$ interaction. In order to further test the dynamical nature of the $f_1(1285)$ state, we investigate the $J/\psi \to \varphi \bar{K}{K}^{\ast }$ decay close to the $\bar{K}{K}^{\ast }$ threshold and make predictions for the ratio of the invariant mass distributions of the $J/\psi \to \varphi \bar{K}{K}^{\ast }$ decay and the $J/\psi \to \varphi f_1(1285)$ partial decay width with all the parameters of the mechanism fixed in previous studies. The results can be tested in future experiments and therefore offer new clues on the nature of the $f_1(1285)$ state.

    hep-phhep-exnucl-exnucl-thPLB(2016)·9 citations
14. 14*

    Analysis of Forward-Backward and Lepton Polarization Asymmetries in $B\to K_1{\ell }^{+}{\ell }^{-}$ Decays in the Two-Higgs-doublet Model

    Naveed Ahmed🇵🇰 · Ishtiaq Ahmed🇧🇷 · M. Jamil Aslam🇵🇰

    The exclusive semileptonic $B\to K_1(1270){\ell }^{+}{\ell }^{-}$ ($\ell =\mu ,\tau$) decays are analyzed in variants of two Higgs double models (THDMs). The mass eigenstates $K_1(1270)$ and $K_1(1400)$ are the mixture of two axial-vector SU(3) ${}^1{P}_1$ and ${}^3{P}_1$ states with the mixing angle ${\theta }_K$. Making use of the form factors calculated in the Light Cone QCD approach and by taking the mixing angle ${\theta }_K=-34^{\circ }$, the impact of the parameters of the THDMs on different asymmetries in above mentioned semileptonic $B$ meson decays are studied. In this context the forward-backward asymmetry and different lepton polarization asymmetries have been analyzed. We have found comprehensive effects of the parameters of the THDMs on the above mentioned asymmetries. Therefore, the precise measurements of these asymmetries at the LHC and different $B$ factories, for the above mentioned processes, can serve as a good tool to put some indirect constraints on the parametric space of the different versions of THDM.

    hep-phPTEP(2015)·3 citations
15. 15*

    Low-energy constants from ALEPH hadronic tau decay data

    Diogo Boito🇧🇷 · Anthony Francis🇨🇦 · Maarten Golterman🇺🇸 · Renwick Hudspith🇨🇦 · Randy Lewis🇨🇦 · Kim Maltman🇨🇦 · Santiago Peris🇪🇸

    We determined the NLO chiral low-energy constant $L_{10}$, and various combinations of NNLO chiral low-energy constants employing recently revised ALEPH results for the non-strange vector (V) and axial-vector (A) hadronic tau decay distributions and recently updated RBC/UKQCD lattice data for the non-strange V-A two-point function. In this talk, we explain the ingredients of this determination. Our errors are at or below the level expected for contributions of yet higher order in the chiral expansion, suggesting that our results exhaust the possibilities of what can be meaningfully achieved in an NNLO analysis.

    hep-phhep-latPoS(2016)·0 citations
16. 16*

    Search for Flavor Changing Neutral Currents in $t\to Hc,H\to \tau \tau$ Decay at the LHC

    Xin Chen🇨🇳 · Li-Gang Xia🇨🇳

    The prospects of searching for the flavor changing neutral current effect in the decay of $t\to Hc,H\to \tau \tau$ are investigated with the simulated $p-p$ collision data for the ATLAS detector at the LHC, where the Higgs mass is assumed to be 125~GeV. A fit based on the constraints from the Higgs mass and the tau decay kinematics is performed for each event, which improves significantly the Higgs and top mass reconstruction and helps the signal-background separation. Boosted Decision Trees discriminants are developed to achieve an optimal sensitivity of searching for the FCNC signal. An expected upper limit of the branching ratio $\mathcal{B}(t\to Hc)$ at $95\%$ confidence level of 0.25\% is obtained with a data set of 100~fb${}^{-1}$ at $\sqrt{s}=13$ TeV during the LHC Run-2 period.

    hep-phhep-exPRD(2016)·12 citations
17. 17*

    Resumming large higher-order corrections in non-linear QCD evolution

    E. Iancu🇫🇷 · J.D. Madrigal🇫🇷 · A.H. Mueller🇺🇸 · G. Soyez🇫🇷 · D.N. Triantafyllopoulos🇮🇹

    Linear and non-linear QCD evolutions at high energy suffer from severe issues related to convergence, due to higher order corrections enhanced by large double and single transverse logarithms. We resum double logarithms to all orders by taking into account successive soft gluon emissions strongly ordered in lifetime. We further resum single logarithms generated by the first non-singular part of the splitting functions and by the one-loop running of the coupling. The resulting collinearly improved BK equation admits stable solutions, which are used to successfully fit the HERA data at small-x for physically acceptable initial conditions and reasonable values of the fit parameters.

    hep-phNucl.Part.Phys.Proc.(2016)·1 citation
18. 18*

    Model studies of the chiral and deconfinement transitions in QCD

    William R. Naylor🇳🇴

    The Doctoral thesis of William Naylor. Gives the background of the three papers included, specifically introducing both the quark meson model and the NJL model, the basic formalism of thermal field theory, and functional renormalization group (including some details on numerically solving the FRG equation for the QM model).

    hep-ph0 citations
19. 19*

    Holographic entropy and real-time dynamics of quarkonium dissociation in non-Abelian plasma

    Ioannis Iatrakis🇺🇸 · Dmitri E. Kharzeev🇺🇸

    The peak of the heavy quark pair entropy at the deconfinement transition, observed in lattice QCD, suggests that the transition is effectively driven by the increase of the entropy of bound states. The growth of the entropy with the inter-quark distance leads to the emergent entropic force that induces dissociation of quarkonium states. Since the quark-gluon plasma around the transition point is a strongly coupled system, we use the gauge-gravity duality to study the entropy of heavy quarkonium and the real-time dynamics of its dissociation. In particular, we employ the Improved Holographic QCD model as a dual description of large $N_c$ Yang Mills theory. Studying the dynamics of the fundamental string between the quarks placed on the boundary, we find that the entropy peaks at the transition point. We also study the real-time dynamics of the system by considering the holographic string falling in the black hole horizon where it equilibrates. In the vicinity the deconfinement transition, the dissociation time is found to be less than a fermi, suggesting that the entropic destruction is the dominant dissociation mechanism in this temperature region.

    hep-phhep-thnucl-thPRD(2016)·32 citations
20. 20*

    Calculating Three Loop Ladder and V-Topologies for Massive Operator Matrix Elements by Computer Algebra

    J. Ablinger🇦🇹 · A. Behring🇩🇪 · J. Blümlein🇩🇪 · A. De Freitas🇩🇪 · A. von Manteuffel🇩🇪 · C. Schneider🇦🇹

    Three loop ladder and $V$-topology diagrams contributing to the massive operator matrix element $A_{Qg}$ are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable $N$ and the dimensional parameter $\epsilon$. Given these representations, the desired Laurent series expansions in $\epsilon$ can be obtained with the help of our computer algebra toolbox. Here we rely on generalized hypergeometric functions and Mellin-Barnes representations, on difference ring algorithms for symbolic summation, on an optimized version of the multivariate Almkvist-Zeilberger algorithm for symbolic integration, and on new methods to calculate Laurent series solutions of coupled systems of differential equations. The solutions can be computed for general coefficient matrices directly for any basis also performing the expansion in the dimensional parameter in case it is expressible in terms of indefinite nested product-sum expressions. This structural result is based on new results of our difference ring theory. In the cases discussed we deal with iterative sum- and integral-solutions over general alphabets. The final results are expressed in terms of special sums, forming quasi-shuffle algebras, such as nested harmonic sums, generalized harmonic sums, and nested binomially weighted (cyclotomic) sums. Analytic continuations to complex values of $N$ are possible through the recursion relations obeyed by these quantities and their analytic asymptotic expansions. The latter lead to a host of new constants beyond the multiple zeta values, the infinite generalized harmonic and cyclotomic sums in the case of $V$-topologies.

    hep-phcs.SChep-thmath-ph+1Comput.Phys.Commun.(2016)·130 citations
21. 21*

    $\Psi (2S)$ decay to $J/\Psi (1S)$ +2$\pi$ or $J/\Psi (1S)$ + $\sigma$ + 2$\pi$

    Leonard S. Kisslinger🇺🇸 · Li-juan Zhou🇨🇳 · Wei-xing Ma🇨🇳

    The BES Collaboration has measured $\Psi (2S)$ decay to $J/\Psi {\pi }^{+}{\pi }^{-}$. Using the mixed hybrid theory for the $\Psi (2S)$ we estimate the decay to $J/\Psi (1S)$ + $\sigma$. Using the known $\sigma \to 2\pi$ coupling constant, we estimate the $\Psi (2S)$ to $J/\Psi (1S)$ + $2\pi$ decay rate and angular distribution. This is an extension of our previous research on $\Psi (2S)$ Decay to $J/\Psi (1S)$ +$\sigma$ + 2${\pi }^o$, without the production of 2${\pi }^o$, and with an estimate of the $\sigma \to {\pi }^{+}+{\pi }^{-}$ transition.

    hep-ph0 citations
22. 22*

    Gravitational waves as a probe of extended scalar sectors with the first order electroweak phase transition

    Mitsuru Kakizaki🇯🇵 · Shinya Kanemura🇯🇵 · Toshinori Matsui🇯🇵

    We discuss spectra of gravitational waves which are originated by the strongly first order phase transition at the electroweak symmetry breaking, which is required for a successful scenario of electroweak baryogenesis. Such spectra are numerically evaluated without high temperature expansion in a set of extended scalar sectors with additional N isospin-singlet fields as a concrete example of renormalizable theories. We find that the produced gravitational waves can be significant, so that they are detectable at future gravitational wave interferometers such as DECIGO and BBO. Furthermore, since the spectra strongly depend on N and the mass of the singlet fields, our results indicate that future detailed observation of gravitational waves can be in general a useful probe of extended scalar sectors with the first order phase transition.

    hep-phPRD(2015)·159 citations
23. 23*

    Constraints on deviations from $\Lambda$CDM within Horndeski gravity

    Emilio Bellini🇪🇸 · Antonio J. Cuesta🇪🇸 · Raul Jimenez🇪🇸 · Licia Verde🇪🇸

    Recent anomalies found in cosmological datasets such as the low multipoles of the Cosmic Microwave Background or the low redshift amplitude and growth of clustering measured by e.g., abundance of galaxy clusters and redshift space distortions in galaxy surveys, have motivated explorations of models beyond standard $\Lambda$CDM. Of particular interest are models where general relativity (GR) is modified on large cosmological scales. Here we consider deviations from $\Lambda$CDM+GR within the context of Horndeski gravity, which is the most general theory of gravity with second derivatives in the equations of motion. We adopt a parametrization in which the four additional Horndeski functions of time ${\alpha }_i(t)$ are proportional to the cosmological density of dark energy ${\Omega }_{DE}(t)$. Constraints on this extended parameter space using a suite of state-of-the art cosmological observations are presented for the first time. Although the theory is able to accommodate the low multipoles of the Cosmic Microwave Background and the low amplitude of fluctuations from redshift space distortions, we find no significant tension with $\Lambda$CDM+GR when performing a global fit to recent cosmological data and thus there is no evidence against $\Lambda$CDM+GR from an analysis of the value of the Bayesian evidence ratio of the modified gravity models with respect to $\Lambda$CDM, despite introducing extra parameters. The posterior distribution of these extra parameters that we derive return strong constraints on any possible deviations from $\Lambda$CDM+GR in the context of Horndeski gravity. We illustrate how our results can be applied to a more general frameworks of modified gravity models.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2016)·163 citations
24. 24*

    Constraining the effective action by a method of external sources

    Bjorn Garbrecht🇩🇪 · Peter Millington🇩🇪

    We propose a novel method of evaluating the effective action, wherein the physical one- and two-point functions are obtained in the limit of non-vanishing external sources. We illustrate the self-consistency of this method by recovering the usual 2PI effective action due to Cornwall, Jackiw and Tomboulis, differing only by the fact that the saddle-point evaluation of the path integral is performed along the extremal quantum, rather than classical, path. As such, this approach is of particular relevance to situations where the dominant quantum and classical paths are non-perturbatively far away from one-another. A pertinent example is the decay of false vacua in radiatively-generated potentials, as may occur for the electroweak vacuum of the Standard Model. In addition, we describe how the external sources may instead be chosen so as to yield the two-particle-point-irreducible (2PPI) effective action of Coppens and Verschelde. Finally, in the spirit of the symmetry-improved effective action of Pilaftsis and Teresi, we give an example of how the external sources can be used to preserve global symmetries in truncations of the 2PI effective action. Specifically, in the context of an O(2) model with spontaneous symmetry breaking, we show that this approach allows the Hartree-Fock approximation to be re-organized, such that the Goldstone boson remains massless algebraically in the symmetry-broken phase and we obtain the correct second-order thermal phase transition.

    ↳ hep-thhep-phNPB(2016)·47 citations
25. 25*

    Novel Collective Phenomena in High-Energy Proton-Proton and Proton-Nucleus Collisions

    Kevin Dusling🇺🇸 · Wei Li🇺🇸 · Bjoern Schenke🇺🇸

    The observation of long-range collective correlations for particles emitted in high-multiplicity pp and pPb collisions has opened up new opportunities of investigating novel high-density QCD phenomena in small colliding systems. We review experimental results related to the studies of collective phenomena in small systems from RHIC and the LHC over the past several years. Latest development in theoretical interpretations motivated by different frameworks are also reviewed, and confronted with the experimental data. Perspectives on possible future directions are discussed, with the aim of further exploring the rich emergent QCD phenomena.

    ↳ nucl-exhep-exhep-phnucl-thIJMPE(2016)·301 citations
26. 26*

    Physical observables from boundary artifacts: scalar glueball in Yang-Mills theory

    Abhishek Chowdhury🇮🇳 · A. Harindranath🇮🇳 · Jyotirmoy Maiti🇮🇳

    By relating the functional averages of a generic scalar operator in simulations with Open (O) and Periodic (P) boundary conditions (BCs) respectively for $SU(3)$ lattice gauge theory, we show that the scalar glueball mass and the glueball to vacuum matrix element can be extracted very efficiently from the former. Numerical results are compared with those extracted from the two point function of the time slice energy density (both PBC and OBC). The scaling properties of the mass and the matrix element are studied with the help of Wilson (gradient) flow.

    ↳ hep-lathep-exhep-phJHEP(2016)·6 citations
27. 27*

    Cosmic Microwave Background Spectral Distortions from Cosmic String Loops

    Madeleine Anthonisen🇨🇦 · Robert Brandenberger🇨🇦 · Alex Laguë🇨🇦 · Ian A. Morrison🇨🇦 · Daixi Xia🇨🇦

    Cosmic string loops contain cusps which decay by emitting bursts of particles. A significant fraction of the released energy is in the form of photons. These photons are injected non-thermally and can hence cause spectral distortions of the Cosmic Microwave Background (CMB). Under the assumption that cusps are robust against gravitational back-reaction, we compute the fractional energy density released as photons in the redshift interval where such non-thermal photon injection causes CMB spectral distortions. Whereas current constraints on such spectral distortions are not strong enough to constrain the string tension, future missions such as the PIXIE experiment will be able to provide limits which rule out a range of string tensions between $G\mu \sim 10^{-15}$ and $G\mu \sim 10^{-12}$, thus ruling out particle physics models yielding these kind of intermediate-scale cosmic strings.

    ↳ astro-ph.COhep-phJCAP(2016)·10 citations
28. 28*

    First measurement of radioactive isotope production through cosmic-ray muon spallation in Super-Kamiokande IV

    Super-Kamiokande Collaboration (Y. Zhang (Tsinghua U.) et al.)

    Cosmic-ray-muon spallation-induced radioactive isotopes with $\beta$ decays are one of the major backgrounds for solar, reactor, and supernova relic neutrino experiments. Unlike in scintillator, production yields for cosmogenic backgrounds in water have not been exclusively measured before, yet they are becoming more and more important in next generation neutrino experiments designed to search for rare signals. We have analyzed the low-energy trigger data collected at Super-Kamiokande-IV in order to determine the production rates of ${}^{12}$B, ${}^{12}$N, ${}^{16}$N, ${}^{11}$Be, ${}^9$Li, ${}^8$He, ${}^9$C, ${}^8$Li, ${}^8$B and ${}^{15}$C. These rates were extracted from fits to time differences between parent muons and subsequent daughter $\beta$'s by fixing the known isotope lifetimes. Since ${}^9$Li can fake an inverse-beta-decay reaction chain via a $\beta +n$ cascade decay, producing an irreducible background with detected energy up to a dozen MeV, a dedicated study is needed for evaluating its impact on future measurements; the application of a neutron tagging technique using correlated triggers was found to improve this ${}^9$Li measurement. The measured yields were generally found to be comparable with theoretical calculations, except the cases of the isotopes ${}^8$Li/${}^8$B and ${}^9$Li.

    ↳ hep-exastro-ph.HEhep-phphysics.ins-detPRD(2016)·97 citations
29. 29*

    Electroweak results from the ATLAS and CMS experiments

    Junjie Zhu🇺🇸

    I summarize an extensive ATLAS and CMS electroweak physics program that involves a variety of single boson, diboson, triboson, and vector boson scattering measurements. The relevance of these studies to our understanding of the electroweak sector and electroweak symmetry breaking is emphasized. I describe the recent results and prospects for future measurements.

    ↳ hep-exhep-ph0 citations
30. 30*

    Perfect fluids with $\omega =\mathrm{const}$ as sources of scalar cosmological perturbations

    Maxim Eingorn🇺🇸 · Ruslan Brilenkov🇺🇦

    We make a generalization of a self-consistent first-order perturbation scheme, being suitable for all (sub-horizon and super-horizon) scales, which has been recently constructed for the concordance cosmological model and discrete presentation of matter sources, to the case of extended models with extra perfect fluids and continuous presentation. Namely, we derive a single equation determining the scalar perturbation and covering the whole space as well as define the corresponding universal Yukawa interaction range. We also demonstrate explicitly that the structure growth is suppressed at distances exceeding this fundamental range.

    ↳ gr-qcastro-ph.COhep-phhep-thPhys.Dark Univ.(2017)·20 citations
31. 31*

    Low-$\ell$ CMB from String-Scale SUSY Breaking?

    A. Sagnotti🇮🇹

    Models of inflation are instructive playgrounds for supersymmetry breaking in Supergravity and String Theory. In particular, combinations of branes and orientifolds that are not mutually BPS can lead to \emph{brane supersymmetry breaking}, a phenomenon where non--linear realizations are accompanied, in tachyon--free vacua, by the emergence of steep exponential potentials. When combined with milder terms, these exponentials can lead to slow--roll after a fast ascent and a turning point. This leaves behind distinctive patterns of scalar perturbations, where pre--inflationary peaks can lie well apart from an almost scale invariant profile. I review recent attempts to connect these power spectra to the low--$\ell$ CMB, and a corresponding one--parameter extension of $\Lambda$CDM with a low--frequency cut $\Delta$. A detailed likelihood analysis led to $\Delta =(0.351\pm 0.114)\times 10^{-3}\text{mbox}{Mpc}^{-1}$, at $99.4\%$ confidence level, in an extended Galactic mask with $f_{sky}=39\%$, to be compared with a nearby value at $88.5\%$ in the standard Planck 2015 mask with $f_{sky}=94\%$. In these scenarios one would be confronted, in the CMB, with relics of an epoch of deceleration that preceded the onset of slow--roll.

    ↳ astro-ph.COgr-qchep-phhep-thMod.Phys.Lett.A(2016)·9 citations
32. 32*

    Solar WIMPs Unraveled: Experiments, astrophysical uncertainties, and interactive Tools

    Matthias Danninger🇨🇦 · Carsten Rott🇰🇷

    The absence of a neutrino flux from self-annihilating dark matter captured in the Sun has tightly constrained some leading particle dark matter scenarios. The impact of astrophysical uncertainties on the capture process of dark matter in the Sun and hence also the derived constraints by neutrino telescopes need to be taken into account. In this review we have explored relevant uncertainties in solar WIMP searches, summarized results from leading experiments, and provided an outlook into upcoming searches and future experiments. We have created an interactive plotting tool that allows the user to view current limits and projected sensitivities of major experiments under changing astrophysical conditions.

    ↳ astro-ph.HEhep-phPhys.Dark Univ.(2014)·38 citations
33. 33*

    Heavy Vector and Axial-Vector Mesons in Hot and Dense Asymmetric Strange Hadronic Matter

    Arvind Kumar · Rahul Chhabra

    We calculate the effects of finite density and temperature of isospin asymmetric strange hadronic matter, for different strangeness fractions, on the in-medium properties of vector $\left(D^{\ast },D_s^{\ast },B^{\ast },B_s^{\ast }\right)$ and axial-vector $\left(D_1,D_{1s},B_1,B_{1s}\right)$ mesons, using chiral hadronic SU(3) model and QCD sum rules. We focus on the evaluation of in-medium mass-shift and shift in decay constant of above vector and axial-vector mesons. In QCD sum rule approach, the properties, e.g., the masses and decay constants of vector and axial-vector mesons are written in terms of quark and gluon condensates. These quark and gluon condensates are evaluated in the present work within chiral SU(3) model, through the medium modification of, scalar-isoscalar fields $\sigma$ and $\zeta$, the scalar-isovector field $\delta$ and scalar dilaton field $\chi$, in the strange hadronic medium which includes both nucleons as well as hyperons. As we shall see in detail, the masses and decay constants of heavy vector and axial-vector mesons are affected significantly due to isospin asymmetry and strangeness fraction of the medium and these modifications may influence the experimental observables produced in heavy ion collision experiments. The results of present investigations of in-medium properties of vector and axial-vector mesons at finite density and temperature of strange hadronic medium may be helpful for understanding the experimental data from heavy-ion collision experiments in-particular for the Compressed Baryonic Matter (CBM) experiment of FAIR facility at GSI, Germany.

    ↳ nucl-thhep-phPhysical Review C 92, 035208 (2015)
34. 34*

    Reheating signature in the gravitational wave spectrum from self-ordering scalar fields

    Sachiko Kuroyanagi🇯🇵 · Takashi Hiramatsu🇯🇵 · Jun'ichi Yokoyama🇯🇵

    We investigate the imprint of reheating on the gravitational wave spectrum produced by self-ordering of multi-component scalar fields after a global phase transition. The equation of state of the Universe during reheating, which usually has different behaviour from that of a radiation-dominated Universe, affects the evolution of gravitational waves through the Hubble expansion term in the equations of motion. This gives rise to a different power-law behavior of frequency in the gravitational wave spectrum. The reheating history is therefore imprinted in the shape of the spectrum. We perform $512^3$ lattice simulations to investigate how the ordering scalar field reacts to the change of the Hubble expansion and how the reheating effect arises in the spectrum. We also compare the result with inflation-produced gravitational waves, which has a similar spectral shape, and discuss whether it is possible to distinguish the origin between inflation and global phase transition by detecting the shape with future direct detection gravitational wave experiments such as DECIGO.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2016)·10 citations
35. 35*

    Clustering in nuclei from ab initio nuclear lattice simulations

    Ulf-G. Meißner🇩🇪

    Nuclear Lattice Effective Field Theory is a new many-body approach that is firmly rooted in the symmetries of QCD. In particular, it allows for truly ab initio calculations of nuclear structure and reactions. In this talk, I focus on the emergence of alpha-clustering in nuclei based on this approach. I also discuss various recent achievements, the deficiencies of the chiral forces used at present and the prospects to improve upon these and the calculations of nuclear properties and dynamics.

    ↳ nucl-thhep-lathep-phnucl-ex1 citation
36. 36*

    On the Future High Energy Colliders

    Vladimir Shiltsev🇺🇸

    High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of the next generation collider facilities have been proposed and are currently under consideration for the medium and far-future of accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance potential and cost range.

    ↳ physics.acc-phhep-exhep-phphysics.ins-det4 citations
37. 37*

    Reformulation of the Georgi-Glashow model and some constraints on its classical fields

    Ahmad Mohamadnejad🇮🇷

    We study the SU(2) Georgi-Glashow model and suggest a decomposition for its fields and obtain a Lagrangian based on new variables. We use Cho's restricted decomposition as a result of a vacuum condition of the Georgi-Glashow model. This model with no external sources leads us to the Cho extended decomposition. We interpret the puzzling field, $\text{n}$, in Cho's decomposition as the color direction of the scalar field in the Georgi-Glashow model. We also study another constraint, condensate phase, and generalize Cho's extended decomposition. Finally, we argue about a decomposition form that Faddeev and Niemi proposed in this constrained Georgi-Glashow model.

    ↳ hep-thhep-phPRD(2015)·2 citations
38. 38*

    Dark matter direct-detection experiments

    Teresa Marrodan Undagoitia🇩🇪 · Ludwig Rauch🇩🇪

    In the past decades, several detector technologies have been developed with the quest to directly detect dark matter interactions and to test one of the most important unsolved questions in modern physics. The sensitivity of these experiments has improved with a tremendous speed due to a constant development of the detectors and analysis methods, proving uniquely suited devices to solve the dark matter puzzle, as all other discovery strategies can only indirectly infer its existence. Despite the overwhelming evidence for dark matter from cosmological indications at small and large scales, a clear evidence for a particle explaining these observations remains absent. This review summarises the status of direct dark matter searches, focussing on the detector technologies used to directly detect a dark matter particle producing recoil energies in the keV energy scale. The phenomenological signal expectations, main background sources, statistical treatment of data and calibration strategies are discussed.

    ↳ physics.ins-detastro-ph.IMhep-phJ.Phys.G(2016)·551 citations
39. 39*

    Bounce Inflation Cosmology with Standard Model Higgs Boson

    Youping Wan🇨🇳 · Taotao Qiu🇨🇳 · Fa Peng Huang🇨🇳 · Yi-Fu Cai🇨🇳 · Hong Li🇨🇳 · Xinmin Zhang🇨🇳

    It is of great interest to connect cosmology in the early universe to the Standard Model of particle physics. In this paper, we try to construct a bounce inflation model with the standard model Higgs boson, where the one loop correction is taken into account in the effective potential of Higgs field. In this model, a Galileon term has been introduced to eliminate the ghost mode when bounce happens. Moreover, due to the fact that the Fermion loop correction can make part of the Higgs potential negative, one naturally obtains a large equation of state(EoS) parameter in the contracting phase, which can eliminate the anisotropy problem. After the bounce, the model can drive the universe into the standard higgs inflation phase, which can generate nearly scale-invariant power spectrum.

    ↳ gr-qcastro-ph.COhep-phhep-thJCAP(2015)·44 citations
40. 40*

    Cosmological perturbations in coherent oscillating scalar field models

    J. A. R. Cembranos🇪🇸 · A. L. Maroto🇪🇸 · S. J. Núñez Jareño🇪🇸

    The fact that fast oscillating homogeneous scalar fields behave as perfect fluids in average and their intrinsic isotropy have made these models very fruitful in cosmology. In this work we will analyse the perturbations dynamics in these theories assuming general power law potentials $V(\varphi )=\lambda |\varphi {|}^n/n$. At leading order in the wavenumber expansion, a simple expression for the effective sound speed of perturbations is obtained $c_{\text{eff}}^2=\omega =(n-2)/(n+2)$ with $\omega$ the effective equation of state. We also obtain the first order correction in $k^2/{\omega }_{\text{eff}}^2$, when the wavenumber $k$ of the perturbations is much smaller than the background oscillation frequency, ${\omega }_{\text{eff}}$. For the standard massive case we have also analysed general anharmonic contributions to the effective sound speed. These results are reached through a perturbed version of the generalized virial theorem and also studying the exact system both in the super-Hubble limit, deriving the natural ansatz for $\delta \varphi$; and for sub-Hubble modes, exploiting Floquet's theorem.

    ↳ astro-ph.COgr-qchep-phJHEP(2016)·73 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.