Wed·Oct 21, 2015Wednesday·October 21, 2015

1. 01*

   Pseudoscalar-exchange contribution to $(g-2{)}_{\mu }$ from rational approximants

   Pablo Sanchez-Puertas🇩🇪 · Pere Masjuan🇩🇪

   We present our recent results on the hadronic light-by-light pseudoscalar-exchange contribution to the anomalous magnetic moment of the muon using rational approximants. Our work provides a generalization of Padé approximants to the bivariate case to describe the most general doubly-virtual transition form factor, which is required in the calculation. This method provides a powerful tool to systematically implement the known experimental data on transition form factors in the space-like region and low energies in a model-independent way. Given the lack of experimental data on the doubly-virtual transition form factor, we make use of the pseduoscalar decays into lepton pairs. We find an interesting and puzzling situation which calls for new experimental measurements to clarify the present state.

   hep-phhep-ex5 citations
2. 02*

   Theoretical Uncertainties in Proton Lifetime Estimates

   Helena Kolešová🇨🇿 · Michal Malinský🇨🇿 · Timon Mede🇨🇿

   We recapitulate the primary sources of theoretical uncertainties in proton lifetime estimates in renormalizable, four-dimensional and non-supersymmetric grand unifications that represent the most conservative framework in which this question may be addressed at the perturbative level. We point out that many of these uncertainties are so severe that there are only very few scenarios in which an NLO approach, as crucial as it is for a real testability of any specific model, is actually sensible. Among these, the most promising seems to be the minimal renormalizable SO(10) GUT whose high-energy gauge symmetry is spontaneously broken by the adjoint and the five-index antisymmetric irreducible representations.

   hep-phAIP Conf.Proc.(2016)·3 citations
3. 03*

   Reply to "Comment on `Axion induced oscillating electric dipole moments' " [1]

   Christopher T. Hill🇺🇸

   We respond to a paper of Flambaum, et.al. [Phys. Rev. D95, no. 5, 058701 (2017)], claiming there is no effective induced oscillating electric dipole moment, e.g., for the electron, arising from interaction with an oscillating cosmic axion background via the anomaly. The relevant Feynman amplitude, Fig.(1), as computed by Flambaum et.al., becomes a total divergence, and vanishes. Contrary to this result, we obtained a nonvanishing amplitude, that yields physical electric dipole radiation for an electron (or any magnetic dipole moment) immersed in a cosmic axion field. We argue that the Flambaum et.al. counter-claim is incorrect, and is based upon a misunderstanding of a physics choice vs. gauge choice, and an assumption that electric dipoles be defined only by coupling to static (constant in time) electric fields.

   hep-phhep-exhep-thPRD(2017)·8 citations
4. 04*

   Sterile neutrino Dark Matter production from scalar decay in a thermal bath

   Marco Drewes🇩🇪 · Jin U Kang🇨🇳

   We calculate the production rate of singlet fermions from the decay of neutral or charged scalar fields in a hot plasma. We find that there are considerable thermal corrections when the temperature of the plasma exceeds the mass of the decaying scalar. We give analytic expressions for the temperature-corrected production rates in the regime where the decay products are relativistic. We also study the regime of non-relativistic decay products numerically. Our results can be used to determine the abundance and momentum distribution of Dark Matter particles produced in scalar decays. The inclusion of thermal corrections helps to improve predictions for the free streaming of the Dark Matter particles, which is crucial to test the compatibility of a given model with cosmic structure formation. With some modifications, our results may be generalised to the production of other Dark Matter candidates in scalar decays.

   hep-phastro-ph.COJHEP(2016)·68 citations
5. 05*

   Model-independent determination of the axial mass parameter in quasielastic antineutrino-nucleon scattering

   Bhubanjyoti Bhattacharya🇨🇦 · Gil Paz🇺🇸 · Anthony J. Tropiano🇺🇸

   Understanding the charged current quasielestic (CCQE) neutrino-nucleus interaction is important for precision studies of neutrino oscillations. The theoretical description of the interaction depends on the combination of a nuclear model with the knowledge of form factors. While the former has received considerable attention, the latter, in particular the axial form factor, is implemented using the historical dipole model. Instead, we use a model-independent approach, presented in a previous study, to analyze the muon antineutrino CCQE mineral oil data published by the MiniBooNE collaboration. We combine the cross section for scattering of antineutrinos off protons in carbon and hydrogen, using the same axial form factor for both. The extracted value of the axial mass parameter $m_A=0.84_{-0.04}^{+0.12}\pm 0.11\mathrm{GeV}$ is in very good agreement with the model-independent value extracted from MiniBooNE's neutrino data. Going beyond a one-parameter description of the axial form factor, we extract values of the axial form factor in the range of $Q^2=\mathrm{0.1...1.0}$ GeV${}^2$, finding a very good agreement with the analogous extraction from the neutrino data. We discuss the implications of these results.

   hep-phhep-exnucl-exnucl-thPRD(2015)·39 citations
6. 06*

   Non-Global Correlations in Collider Physics

   Andrew J. Larkoski🇺🇸 · Ian Moult🇺🇸

   Despite their importance for precision QCD calculations, correlations between in- and out-of-jet regions of phase space have never directly been observed. These so-called non-global effects are present generically whenever a collider physics measurement is not explicitly dependent on radiation throughout the entire phase space. In this paper, we introduce a novel procedure based on mutual information, which allows us to isolate these non-global correlations between measurements made in different regions of phase space. We study this procedure both analytically and in Monte Carlo simulations in the context of observables measured on hadronic final states produced in $e^{+}{e}^{-}$ collisions, though it is more widely applicable. The procedure exploits the sensitivity of soft radiation at large angles to non-global correlations, and we calculate these correlations through next-to-leading logarithmic accuracy. The bulk of these non-global correlations are found to be described in Monte Carlo simulation. They increase by the inclusion of non-perturbative effects, which we show can be incorporated in our calculation through the use of a model shape function. This procedure illuminates the source of non-global correlations and has connections more broadly to fundamental quantities in quantum field theory.

   hep-phhep-exPRD(2016)·9 citations
7. 07*

   Thermal History of the Universe After Inflation

   Scott Watson🇺🇸

   When did the universe thermalize? In this talk I review the status of this issue and its importance in establishing the expected properties of dark matter, the growth of large-scale structure, and the viability of inflation models when confronted with CMB observations. I also present a novel approach to tackling the theoretical challenges surrounding inflationary (p)reheating, which seeks to extend past work on the Effective Field Theory of Inflation to the time of reheating.

   hep-phastro-ph.COhep-thAIP Conf.Proc.(2016)·0 citations
8. 08*

   Radiative plateau inflation

   Guillermo Ballesteros🇫🇷 · Carlos Tamarit🇬🇧

   We describe how monomial chaotic inflation becomes compatible with the latest CMB data thanks to radiative corrections producing a plateau. The interactions of the inflation with other fields, required for reheating, can flatten the potential and moderate the production of primordial gravitational waves, keeping these below the current upper bound. We show that the appearance of a plateau requires that the inflaton couples to fermions and to another scalar or a gauge group. We give concrete examples of minimal particle physics models leading to plateaus for quadratic and quartic chaotic inflation. We also provide a three-parameter model-independent description of radiatively corrected inflation that is amenable to CMB analyses.

   hep-phastro-ph.COgr-qchep-thJHEP(2016)·40 citations
9. 09*

   Mirage Models Confront the LHC: III. Deflected Mirage Mediation

   Lisa L. Everett🇺🇸 · Todd Garon🇺🇸 · Bryan L. Kaufman🇺🇸 · Brent D. Nelson🇺🇸

   We complete the study of a class of string-motivated effective supergravity theories in which modulus-induced soft supersymmetry breaking is sufficiently suppressed in the observable sector so as to be competitive with anomaly-mediated supersymmetry breaking. Here we consider deflected mirage mediation (DMM), where contributions from gauge mediation are added to those arising from gravity mediation and anomaly mediation. We update previous work that surveyed the rich parameter space of such theories, in light of data from the CERN Large Hadron Collider (LHC) and recent dark matter detection experiments. Constraints arising from LHC superpartner searches at $\sqrt{s}=8\mathrm{TeV}$ are considered, and discovery prospects at $\sqrt{s}=14\mathrm{TeV}$ are evaluated. We find that deflected mirage mediation generally allows for SU(3)-charged superpartners of significantly lower mass (given current knowledge of the Higgs mass and neutralino relic density) than was found for the `pure' mirage mediation models of Kachru et al. Consequently, discovery prospects are enhanced for many combinations of matter multiplet modular weights. We examine the experimental challenges that will arise due to the prospect of highly compressed spectra in DMM, and the correlation between accessibility at the LHC and discovery prospects at large-scale liquid xenon dark matter detectors.

   hep-phPRD(2016)·7 citations
10. 10*

    Higgs dark matter from a warped extra dimension

    Aqeel Ahmed🇵🇱 · Bohdan Grzadkowski🇵🇱 · John F. Gunion🇺🇸 · Yun Jiang🇩🇰

    We present a 5D ${\mathbb{Z}}_2$-symmetric IR-UV-IR model with a {\it warped KK-parity} under which the bulk fields have towers of either even or odd KK-modes. We show that this ${\mathbb{Z}}_2$-symmetric geometry is equivalent to two times the UV-IR geometry (Randall-Sundrum model) provided each bulk field is subject to Neumann (or mixed) and Dirichlet boundary conditions at the UV-brane for even and odd fields, respectively. The 5D Standard Model (SM) bosonic sector is considered, such that in the 4D low-energy effective theory the ${\mathbb{Z}}_2$-even zero-modes correspond to the SM degrees of freedom, whereas the ${\mathbb{Z}}_2$-odd zero modes serve as a dark sector. In the zero-mode scalar sector, the even scalar mimics the SM Higgs boson, while the odd scalar (dark-Higgs) is stable and serves as a dark matter candidate. Implications for this dark matter are discussed; it is found that the dark-Higgs can provide only a small fraction of the observed dark matter abundance.

    hep-phhep-thPoS(2015)·2 citations
11. 11*

    QGP formation time and the large photon v2 puzzle in heavy ion collisions

    Fu-Ming Liu🇨🇳

    We investigate the large photon v2 puzzle and the two time scales of thermal and chemical equilibrium in heavy ion collisions. The two-time-scale picture has a weak effect on the transverse moemntum spectrum of direct photons, but a strong effect on the elliptic flow of direct photons. Thus both the spectrum and the elliptic flow of direct photons may be explained with hydro evolution constrained with hadron data. In such a picture, a gluon dominant matter appears in heavy ion collisions. This new matter may impact strongly to other fields such as astrophysics and cosmology.

    hep-phnucl-exNucl.Part.Phys.Proc.(2016)·0 citations
12. 12*

    Three-gluon correlator contribution to Sivers asymmetry in SIDIS

    Ling-Yun Dai🇺🇸

    We study the Sivers asymmetry in semi-inclusive deep inelastic scattering: the three-gluon correlation function contribution. At the cross section level, we establish the matching between the twist-3 collinear factorization approach and the transverse momentum dependent factorization formalism at the moderate transverse momentum region. The so-called coefficient functions when one expands the quark Sivers function in terms of three-gluon correlation functions are derived, which are essential components in the usual transverse momentum dependent evolution formalism. Finally we calculate the transverse-momentum-weighted spin-dependent differential cross section at the next-to-leading order, from which we identify the off-diagonal/three-gluon correlation contribution to the QCD collinear evolution of the twist-3 Qiu-Sterman function.

    hep-phnucl-thPoS(2015)·0 citations
13. 13*

    Hadronic light-by-light contribution to $a_{\mu }$: extended Nambu-Jona-Lasinio, chiral quark models and chiral Lagrangians

    Johan Bijnens (Lund)🇸🇪

    This talk discusses our old work on the hadronic light-by-light contribution to the muon anomalous magnetic moment and some more recent contributions. I discuss the various contributions starting with pseudo-scalar meson exchange, the quark- and pion-loop, as well as scalar and $a_1$-exchange. For the ${\pi }^0$-exchange I point out a possible large enhancement when only connected contributions are included. For the quark-loop I include some comments about the more recent estimates of this contribution. The pion-loop is discussed in more detail, in particular I discuss our unpublished work on including effects from $a_1$ and the polarizability.

    hep-phEPJ Web Conf.(2016)·18 citations
14. 14*

    CHARM-2015 Theory Summary

    Luca Silvestrini🇮🇹

    I present a brief theory overview of the CHARM-2015 conference.

    hep-ph5 citations
15. 15*

    Fragmentation Functions at Next-to-Next-to-Leading Order Accuracy

    Daniele P. Anderle🇩🇪 · Felix Ringer🇺🇸 · Marco Stratmann🇩🇪

    We present a first analysis of parton-to-pion fragmentation functions at next-to-next-to-leading order accuracy in QCD based on single-inclusive pion production in electron-positron annihilation. Special emphasis is put on the technical details necessary to perform the QCD scale evolution and cross section calculation in Mellin moment space. We demonstrate how the description of the data and the theoretical uncertainties are improved when next-to-next-to-leading order QCD corrections are included.

    hep-phPRD(2015)·78 citations
16. 16*

    Operator Structure of TMDs

    P.J. Mulders🇳🇱

    The focus of this talk is on the transverse components of parton momenta. Like for collinear parton distribution functions (PDFs), we are also in the case of transverse momentum dependent (TMD) PDFs, talking about forward matrix elements. While the collinear PDFs describe only spin-spin correlations, the TMD PDFs (or in short TMDs) include spin-momentum correlations, including also time-reversal-odd (T-odd) correlations. The latter are important in the description of single spin asymmetries. In this way TMDs open up new ways of studying the spin structure of hadrons or they can be used as tools that incorporate hadronic structure also in non-collinear situations. The operator structure of TMDs within QCD, in particular the structure of Wilson lines, is more complex than that for collinear functions leading to various ways of breaking of universality. This breaking of universality, however, can be handled within QCD.

    hep-phPoS(2015)·1 citation
17. 17*

    Centrality dependence of K*(892)0 and {\phi}(1020) production at LHC

    Inam-ul Bashir🇮🇳 · Saeed Uddin🇮🇳

    We study the centrality dependence of the mid-rapidity (|y|<0.5) yield (dN/dy) and transverse momentum distributions of K*(892)0 and {\phi}(1020) resonances produced in Pb+Pb collisions at root(sNN) = 2.76 TeV. The mid-rapidity density (dN/dy) and the shape of the transverse momentum spectra are well reproduced by our earlier proposed Unified Statistical Thermal Freeze-out Model (USTFM) which incorporates the effects of both longitudinal as well as transverse hydrodynamic flow. The freeze-out properties in terms of kinetic freeze-out temperature and transverse flow velocity parameter are extracted from the model fits to the ALICE data. The extracted kinetic freeze-out temperature is found to increase with decrease in centrality while as the transverse flow velocity parameter shows a mild decrease towards peripheral collisions. Moreover the centrality dependence of the mid-rapidity system size at freeze-out has also been studied in terms of transverse radius parameter.

    hep-phnucl-thCommun.Theor.Phys.(2017)·11 citations
18. 18*

    Energy Dependence of Particle Ratios in High Energy Nucleus-Nucleus Collisions: A USTFM Approach

    Inam-ul Bashir · Saeed Uddin

    We study the identified particle ratios produced at mid-rapidity in heavy ion collisions, along with their correlations with the collision energy. We employ our earlier proposed Unified Statistical Thermal Freeze-out Model (USTFM), which incorporates the effects of both longitudinal as well as transverse hydrodynamic flow in the hot hadronic system. A fair agreement seen between the experimental data and our model results confirms that the particle production in these collisions is of statistical nature. The variation of the chemical freeze-out temperature and the baryon chemical potential with respect to collision energies is studied. The chemical freeze-out temperature is found to be almost constant beyond the RHIC energy and is found to be close to the QCD predicted phase transition temperature suggesting that the chemical freeze-out occurs soon after the hadronization takes place. The vanishing value of chemical potential at LHC indicates very high degree of nuclear transparency in the collision.

    hep-phnucl-thAdv.High Energy Phys.(2018)·6 citations
19. 19*

    Complementarity of Forward-Backward Asymmetry for discovery of Z' bosons at the Large Hadron Collider

    Elena Accomando🇬🇧 · Alexander Belyaev🇬🇧 · Juri Fiaschi🇬🇧 · Ken Mimasu🇬🇧 · Stefano Moretti🇬🇧 · Claire Shepherd-Themistocleous🇬🇧

    The Forward-Backward Asymmetry (AFB) in Z' physics is commonly only thought of as an observable which possibly allows one to profiling a Z' signal by distinguishing different models embedding such (heavy) spin-1 bosons. In this brief review, we examine the potential of AFB in setting bounds on or even discovering a Z' at the Large Hadron Collider (LHC) and proof that it might be a powerful tool for this purpose. We analyse two different scenarios: Z's with a narrow and wide width, respectively. We find that, in both cases, AFB can complement the conventional searches in accessing Z' signals traditionally based on cross section measurements only.

    hep-phPoS(2015)·4 citations
20. 20*

    Particle multiplicity distributions in p-p Collisions at root(sNN) = 0.9 TeV

    Inam-ul Bashir🇮🇳 · Riyaz Ahmed Bhat🇮🇳 · Saeed Uddin🇮🇳

    The mid-rapidity transverse momentum spectra of hadrons (p, p-bar, K+, K-, K0-short, phi, {\Lambda}, {\Lambda}-bar, {\Xi},{\Xi}-bar, ({\Xi} + {\Xi}-bar), {\Omega}, and {\Omega}-bar) and the available rapidity distributions of the strange hadrons K0-short, ({\Lambda} + {\Lambda}-bar), ({\Xi} + {\Xi}-bar) produced in p-p collisions at LHC energy root(sNN) = 0.9 TeV have been studied using a Unified Statistical Thermal Freeze-out Model (USTFM). The calculated results are found to be in good agreement with the experimental data. The theoretical fits of the transverse momentum spectra using the model calculations provide the thermal freeze-out conditions in terms of the temperature and collective flow parameters for different hadronic species. The study reveal the presence of significant collective flow and a well defined temperature in the system thus indicating the formation of a thermally equilibrated hydrodynamic system in p-p collisions at LHC. Moreover, the fits to the available experimental rapidity distributions data of strange hadrons show the effect of almost complete transparency in p-p collisions at LHC. The model incorporates longitudinal as well as a transverse hydrodynamic flow. The contributions from heavier decay resonances have also been taken into account. We have also imposed the criteria of exact strangeness conservation in the system.

    hep-phnucl-th2 citations
21. 21*

    Long-range properties of $1S$ bottomonium states

    Nora Brambilla🇩🇪 · Gastão Krein🇧🇷 · Jaume Tarrús Castellà🇩🇪 · Antonio Vairo🇩🇪

    In the framework of weakly-coupled pNRQCD, we derive, first, an analytical expression for the chromo-polarizability of $1S$-bottomonium states in agreement with previous determinations. Then we use the QCD trace anomaly to obtain the two-pion production amplitude for the chromo-polarizability operator and match the result to a chiral effective field theory with $1S$-bottomonium states and pions as degrees-of-freedom. In this chiral effective field theory we compute some long-range properties of the $1S$ bottomonium generated by the pion coupling such as the leading chiral logarithm to the $1S$-bottomonium mass and the van der Waals potential between two $1S$-bottomonium states. Both results improve on previously known expressions.

    hep-phnucl-thPRD(2016)·77 citations
22. 22*

    Monte Carlo event generation of photon-photon collisions at colliders

    Ilkka Helenius🇸🇪

    In addition to being interesting in itself, the photon-photon interactions will be an inevitable background for the future electron-positron colliders. Thus to be able to quantify the potential of future electron-positron colliders it is important to have an accurate description of these collisions. Here we present our ongoing work to implement the photon-photon collisions in the Pythia 8 event generator. First we introduce photon PDFs in general and then discuss in more detail one particular set we have used in our studies. Then we will discuss how the parton-shower algorithm in Pythia 8 is modified in case of photon beams and how the beam remnants are constructed. Finally a brief outlook on future developments is given.

    hep-ph0 citations
23. 23*

    $B_c{B}_{c}J/\psi$ Vertex Form Factor at Finite Temperature in the Framework of QCD Sum Rules Approach

    E. Yazici🇹🇷 · H. Sundu🇹🇷 · E. Veli Veliev🇹🇷

    The strong form factor of the $B_c{B}_{c}J/\Psi$ vertex is calculated in the framework of the QCD sum rules method at finite temperature. Taking into account additional operators appearing at finite temperature, thermal Wilson expansion is obtained and QCD sum rules are derived. While increasing temperature, the strong form factor remains unchanged up to $T\simeq 100MeV$ but slightly increases after this point. After $T\simeq 160MeV$, the form factor suddenly decreases up to $T\simeq 170MeV$. The obtained result of the coupling constant by fitting the form factor at $Q^2=-m_{offshell}^2$ at $T=0$ is in a very good agreement with the QCD sum rules calculations at vacuum. Our prediction can be checked in the future experiments.

    hep-phEPJC(2016)·4 citations
24. 24*

    Resolving the $B\to K\pi$ puzzle by Glauber-gluon effects

    Xin Liu🇨🇳 · Hsiang-nan Li🇹🇼 · Zhen-Jun Xiao🇨🇳

    We extend the perturbative QCD formalism including the Glauber gluons, which has been shown to accommodate the measured $B\to \pi \pi$ and $B^0\to {\rho }^0{\rho }^0$ branching ratios simultaneously, to the analysis of the $B\to K\pi$ and $K\bar{K}$ decays. It is observed that the convolution of the universal Glauber phase factors with the transverse-momentum-dependent kaon wave function reveals weaker (stronger) Glauber effects than in the pion ($\rho$ meson) case as expected. Our predictions for the branching ratios and the direct CP asymmetries of the $B\to K\pi$ and $K\bar{K}$ modes at next-to-leading-order accuracy agree well with data. In particular, the predicted difference of the $B^{\pm }\to K^{\pm }{\pi }^0$ and $B^0\to K^{\pm }{\pi }^{\mp }$ direct CP asymmetries, $\Delta A_{K\pi }\equiv A_{\mathrm{CP}}^{\mathrm{dir}}(K^{\pm }{\pi }^0)[0.021\pm 0.016]-A_{\mathrm{CP}}^{\mathrm{dir}}(K^{\pm }{\pi }^{\mp })[-0.081\pm 0.017]=0.102\pm 0.023$, is consistent with the measured $\Delta A_{K\pi }=0.119\pm 0.022$ within uncertainties, and the known $B\to K\pi$ puzzle is resolved. The above $B\to \pi \pi$, $K\pi$ and $K\bar{K}$ studies confirm that the Glauber gluons associated with pseudo-Nambu-Goldstone bosons enhance the color-suppressed tree amplitude significantly, but have a small impact on other topological amplitudes.

    hep-phhep-exPRD(2016)·25 citations
25. 25*

    Linearly polarized gluon effects in unpolarized collisions

    Daniël Boer🇳🇱

    Linear polarization of gluons inside unpolarized hadrons affects the transverse momentum distribution of produced spin-0 particles, such as of the Higgs or (pseudo-)scalar quarkonium states at LHC. Despite the currently unknown amount of linear gluon polarization, a range of predictions can be obtained, using TMD evolution, which indicates that their effect is on the few percent level in Higgs production, but can be much larger in quarkonium production. Together with asymmetries in open charm or bottom production in electro-production at an Electron-Ion Collider, the size and sign of the linear gluon polarization could be extracted experimentally. These processes also allow to test the behavior expected at small $x$ in and outside the saturation region.

    hep-phPoS(2015)·22 citations
26. 26*

    Transverse-momentum resummation for photon pair production at NNLL+NLO

    Leandro Cieri🇮🇹

    We are interested in the transverse-momentum ($q_T$) distribution of a diphoton pair produced in hadron collisions. We resum the logarithmically-enhanced perturbative QCD contributions at small values of $q_T$ up to next-to-next-to-leading logarithmic accuracy. We consistently combine resummation with the known next-to-leading order perturbative result at intermediate and large values of $q_T$ . We include all perturbative terms up to order ${\alpha }_S^2$ in our computation which, after integration over $q_T$ , reproduces the known next-to-next-to-leading order result for the diphoton pair production total cross section. A comparison with LHC data is presented. We estimate the perturbative accuracy of the theoretical calculation by performing the corresponding variation of scales. We anticipate that the effect of the transverse momentum resummation is not only to recover the predictivity of the calculation at small $q_T$ , but also to improve substantially the agreement with the experimental data.

    hep-phhep-ex0 citations
27. 27*

    Simple estimates of the masses of pentaquarks with hidden beauty or strangeness

    Vladimir Kopeliovich (Moscow, INR & Moscow, MIPT)🇷🇺 · Irina Potashnikova (Santa Maria U., Valparaiso)🇨🇱

    The masses of cryptoexotic pentaquarks with hidden beauty are estimated phenomenologically using the results by the LHCb collaboration which discovered recently the cryptoexotic pentaquarks with hidden charm. The expected masses of the hidden beauty pentaquarks are about $10.8$ GeV and $10.7$ GeV in the limit of some kind of heavy quark symmetry. The states with hidden strangeness considered in similar way have masses about $2.37$ Gev and $2.30$ GeV, by several hundreds of MeV higher than states discussed previously in connection with the relatively light positive strangeness pentaquark ${\theta }^{+}$. Empirical data on spectra of pentaquarks can be used to get information about quarkonia interaction with nucleons. The results obtained for the case of heavy flavors are in fair agreement with model of isospin (pion) exchange between flavored baryons and anti-flavored vector mesons, proposed by Karliner and Rosner, and in qualitative agreement with the bound state version of the chiral soliton model.

    hep-phPRD(2016)·17 citations
28. 28*

    Fitting the two-loop renormalized Two-Higgs-Doublet model

    Otto Eberhardt🇮🇹

    We present global fits to the Two-Higgs-Doublet model, assuming a softly broken $Z_2$ symmetry of the types I and II and CP conservation in the scalar potential. We show how much the parameter space is constrained by the combination of the relevant theoretical and experimental inputs, including the LHC data after the first run and interpreting the 125 GeV boson as the light CP even Higgs. Using the next-to-leading order renormalization group equations, we address the questions of vacuum stability and the hierarchy problem in the context of the mentioned Two-Higgs-Doublet models.

    hep-phhep-exPoS(2015)·3 citations
29. 29*

    Two-loop Integrand Decomposition into Master Integrals and Surface Terms

    Harald Ita🇩🇪

    Loop amplitudes are conveniently expressed in terms of master integrals whose coefficients carry the process dependent information. Similarly before integration, the loop integrands may be expressed as a linear combination of propagator products with universal numerator-tensors. Such a decomposition is an important input for the numerical unitarity approach, which constructs integrand coefficients from on-shell tree amplitudes. We present a new method to organise multi-loop integrands into a direct sum of terms that integrate to zero (surface terms) and remaining master integrands. This decomposition facilitates a general, numerical unitarity approach for multi-loop amplitudes circumventing analytic integral reduction. Vanishing integrals are well known as integration-by-parts identities. Our construction can be viewed as an explicit construction of a complete set of integration-by-parts identities excluding doubled propagators. Interestingly, a class of 'horizontal' identities is singled out which hold as well for altered propagator powers.

    ↳ hep-thhep-phPRD(2016)·255 citations
30. 30*

    Model-Independent Dark Energy Equation of State from Unanchored Baryon Acoustic Oscillations

    Jarah Evslin🇨🇳

    Ratios of line of sight baryon acoustic oscillation (BAO) peaks at two redshifts only depend upon the average dark energy equation of states between those redshifts, as the dependence on anchors such as the BAO scale or the Hubble constant is canceled in a ratio. As a result, BAO ratios provide a probe of dark energy which is independent of both the cosmic distance ladder and the early evolution of universe. In this note, we use ratios to demonstrate that the known tension between the Lyman alpha forest BAO measurement and other probes arises entirely from recent (0.57<z<2.34) cosmological expansion. Using ratios of the line of sight Lyman alpha forest and BOSS CMASS BAO scales, we show that there is already more than 3 sigma tension with the standard LambdaCDM cosmological model which implies that either (i) The BOSS Lyman alpha forest measurement of the Hubble parameter was too low as a result of a statistical fluctuation or systematic error or else (ii) the dark energy equation of state falls steeply at high redshift.

    ↳ astro-ph.COhep-phPhys.Dark Univ.(2016)·6 citations
31. 31*

    500 GeV ILC Operating Scenarios

    James E. Brau🇺🇸 · representing ILC Parameters Joint Working Group: T. Barklow (SLAC)🇺🇸 · J. Brau (Oregon) · K. Fujii (KEK)🇯🇵 · J. Gao (IHEP)🇨🇳 · J. List (DESY)🇩🇪 · N.Walker (DESY)🇩🇪 · K. Yokoya (KEK)🇯🇵

    The ILC Technical Design Report documents the design of a 500 GeV linear collider, but does not specify the center-of-mass energy steps of operation for the collider. The ILC Parameters Joint Working Group has studied possible running scenarios, including a realistic estimate of the real time accumulation of integrated luminosity based on ramp-up and upgrade processes, and considered the evolution of the physics outcomes. These physics goals include Higgs precision measurements, top quark measurements and searches for new physics. We present an "optimized" operating scenario and the anticipated evolution of the precision of the ILC measurements.

    ↳ hep-exhep-ph13 citations
32. 32*

    Physics perspectives of heavy-ion collisions at very high energy

    Ning-bo Chang (CCNU)🇨🇳 · Shanshan Cao (LBNL)🇺🇸 · Bao-yi Chen (Tsinghua U)🇨🇳 · Shi-yong Chen (CCNU)🇨🇳 · Zhen-yu Chen (Tsinghua U)🇨🇳 · Heng-Tong Ding (CCNU)🇨🇳 · Min He (NUSTC)🇨🇳 · Zhi-quan Liu (CCNU)🇨🇳 · Long-gang Pang (CCNU)🇨🇳 · Guang-you Qin (CCNU)🇨🇳 · Ralf Rapp (TAMU)🇺🇸 · Björn Schenke (BNL)🇺🇸 and 9 other authors

    Heavy-ion collisions at very high colliding energies are expected to produce a quark-gluon plasma (QGP) at the highest temperature obtainable in a laboratory setting. Experimental studies of these reactions can provide an unprecedented range of information on properties of the QGP at high temperatures. We report theoretical investigations of the physics perspectives of heavy-ion collisions at a future high-energy collider. These include initial parton production, collective expansion of the dense medium, jet quenching, heavy-quark transport, dissociation and regeneration of quarkonia, photon and dilepton production. We illustrate the potential of future experimental studies of the initial particle production and formation of QGP at the highest temperature to provide constraints on properties of strongly interaction matter.

    ↳ nucl-thhep-phSCPMA(2016)·24 citations
33. 33*

    The Yang-Mills gradient flow and SU(3) gauge theory with 12 massless fundamental fermions in a colour-twisted box

    C.-J. David Lin🇹🇼 · Kenji Ogawa🇹🇼 · Alberto Ramos🇨🇭

    We perform the step-scaling investigation of the running coupling constant, using the gradient-flow scheme, in SU(3) gauge theory with twelve massless fermions in the fundamental representation. The Wilson plaquette gauge action and massless unimproved staggered fermions are used in the simulations. Our lattice data are prepared at high accuracy, such that the statistical error for the renormalised coupling, g_GF, is at the subpercentage level. To investigate the reliability of the continuum extrapolation, we employ two different lattice discretisations to obtain g_GF. For our simulation setting, the corresponding gauge-field averaging radius in the gradient flow has to be almost half of the lattice size, in order to have this extrapolation under control. We can determine the renormalisation group evolution of the coupling up to g^2_GF ~ 6, before the onset of the bulk phase structure. In this infrared regime, the running of the coupling is significantly slower than the two-loop perturbative prediction, although we cannot draw definite conclusion regarding possible infrared conformality of this theory. Furthermore, we comment on the issue regarding the continuum extrapolation near an infrared fixed point. In addition to adopting the fit ansatz a'la Symanzik for performing this task, we discuss a possible alternative procedure inspired by properties derived from low-energy scale invariance at strong coupling. Based on this procedure, we propose a finite-size scaling method for the renormalised coupling as a means to search for infrared fixed point. Using this method, it can be shown that the behaviour of the theory around g^2_GF ~ 6 is still not governed by possible infrared conformality.

    ↳ hep-lathep-phJHEP(2015)·39 citations
34. 34*

    Cross-correlation measurement techniques for cavity-based axion and weakly interacting slim particle searches

    Ben T. McAllister🇦🇺 · Stephen R. Parker🇦🇺 · Eugene N. Ivanov🇦🇺 · Michael E. Tobar🇦🇺

    The search for dark matter is of fundamental importance to our understanding of the universe. Weakly-Interacting Slim Particles (WISPs) such as axions and hidden sector photons (HSPs) are well motivated candidates for the dark matter. Some of the most sensitive and mature experiments to detect WISPs rely on microwave cavities, and the detection of weak photon signals. It is often suggested to power combine multiple cavities, which creates a host of technical concerns. We outline a scheme based on cross-correlation for effectively power combining cavities and increasing the signal-to-noise ratio of a candidate WISP signal.

    ↳ physics.ins-dethep-exhep-phIEEE Trans.Ultrason.Ferroelectr.Freq.Control(2019)·18 citations
35. 35*

    Renormalisation Group determination of scalar mass bounds in a simple Yukawa-model

    A. Jakovac🇭🇺 · I. Kaposvari🇭🇺 · A. Patkos🇭🇺

    The scalar mass is determined in the simplest scalar-fermion Yukawa-model in the whole range of stability of the scalar potential. Two versions of the Functional Renormalisation Group (FRG) equations are solved, where also composite fermionic background is taken into account. The close agreement of the results with previous studies taking into account exclusively the effect of the scalar condensate, supports a rather small systematic truncation error of FRG due to the omission of higher dimensional operators.

    ↳ hep-thhep-phInt.J.Mod.Phys.A(2016)·11 citations
36. 36*

    Neutron electric dipole moment using $N_f=2+1+1$ twisted mass fermions

    C. Alexandrou (Univ. of Cyprus and Cyprus Inst.)🇨🇾 · A. Athenodorou (Univ. of Cyprus and Cyprus Inst.)🇨🇾 · M. Constantinou (Univ. of Cyprus and Cyprus Inst.)🇨🇾 · K. Hadjiyiannakou (Univ. of Cyprus and Cyprus Inst.)🇨🇾 · K. Jansen (NIC, DESY-Zeuthen)🇩🇪 · G. Koutsou (Cyprus Inst.)🇨🇾 · K. Ottnad (Univ. of Cyprus and Bonn Univ.)🇨🇾 · M. Petschlies (Cyprus Inst. and Bonn Univ.)🇨🇾

    We evaluate the neutron electric dipole moment $|{\vec{d}}_N|$ using lattice QCD techniques. The gauge configurations analyzed are produced by the European Twisted Mass Collaboration using $N_f=2+1+1$ twisted mass fermions at one value of the lattice spacing of $a\simeq 0.082\mathrm{fm}$ and a light quark mass corresponding to $m_{\pi }\simeq 373\mathrm{MeV}$. Our approach to extract the neutron electric dipole moment is based on the calculation of the $CP$-odd electromagnetic form factor $F_3(Q^2)$ for small values of the vacuum angle $\theta$ in the limit of zero Euclidean momentum transfer $Q^2$. The limit $Q^2\to 0$ is realized either by adopting a parameterization of the momentum dependence of $F_3(Q^2)$ and performing a fit, or by employing new position space methods, which involve the elimination of the kinematical momentum factor in front of $F_3(Q^2)$. The computation in the presence of a $CP$-violating term requires the evaluation of the topological charge $\mathcal{Q}$. This is computed by applying the cooling technique and the gradient flow with three different actions, namely the Wilson, the Symanzik tree-level improved and the Iwasaki action. We demonstrate that cooling and gradient flow give equivalent results for the neutron electric dipole moment. Our analysis yields a value of $|{\vec{d}}_N|=0.045(6)(1)\bar{\theta }e\cdot \mathrm{fm}$ for the ensemble with $m_{\pi }=373$ MeV considered.

    ↳ hep-lathep-exhep-phnucl-thPRD(2016)·52 citations
37. 37*

    The FUNK search for Hidden Photon Dark Matter in the eV range

    Babette Döbrich🇨🇭 · Kai Daumiller🇩🇪 · Ralph Engel🇩🇪 · Joerg Jaeckel🇩🇪 · Marek Kowalski🇩🇪 · Axel Lindner🇩🇪 · Hermann-Josef Mathes🇩🇪 · Javier Redondo🇪🇸 · Markus Roth🇩🇪 · Christoph Schäfer🇩🇪 · Ralf Ulrich🇩🇪 · Darko Veberic🇩🇪

    We give a brief update on the search for Hidden Photon Dark Matter with FUNK. The experiment uses a large spherical mirror, which, if Hidden Photon Dark Matter exists in the accessible mass and coupling parameter range, would yield an optical signal in the mirror's center in an otherwise dark environment. After a test run with a CCD, preparations for a run with a low-noise PMT are under way and described in this proceedings.

    ↳ physics.ins-dethep-exhep-ph13 citations
38. 38*

    Chiral Gravitomagnetic Effect in Topological Superconductors and Superfluids

    Akihiko Sekine🇯🇵

    We theoretically search for dynamical cross-correlated responses of three-dimensional topological superconductors and superfluids. It has been suggested that a gravitational topological term, which is analogous to the theta term in topological insulators, can be derived in three-dimensional time-reversal invariant topological superconductors and superfluids, and that the dynamical gravitational axion field can be realized by the fluctuation of the relative phase, i.e., by the Leggett mode between topological $p$-wave pairing and conventional $s$-wave pairing. In the presence of the dynamical gravitational axion field, we propose the emergence of the "chiral gravitomagnetic effect", a thermal current generation by gravitomagnetic fields, i.e., by mechanical rotations. This effect can be regarded as a thermal counterpart of the chiral magnetic effect which has been studied mainly in Weyl semimetals. We also show the occurrence of the anomalous thermal Hall effect in the bulk. We discuss a possible application of our study to the thermal responses of Weyl superconductors.

    ↳ cond-mat.mes-hallcond-mat.str-elcond-mat.supr-conhep-lat+1PRB(2016)·7 citations
39. 39*

    Can we have another light (~ 145 GeV) Higgs boson?

    S. Khalil🇪🇬 · S. Moretti🇬🇧

    A second light Higgs boson, with mass of approximately 145 GeV, is predicted by non-minimal Supersymmetric models. This new particle can account for an apparent \sim 3 \sigma excess recorded by the CMS experiment at the Large Hadron Collider (LHC) during Run 1. We show how this can be explained in a particular realisation of these scenarios, the (B-L) Supersymmetric Model (BLSSM), which also has other captivating features, like offering an explanation for neutrino masses and relieving the small hierarchy problem of the Minimal Supersymmetric Standard Model (MSSM).

    ↳ hep-exhep-ph3 citations
40. 40*

    Dark Radiation and Inflationary Freedom

    Stefano Gariazzo🇮🇹

    A relaxed primordial power spectrum (PPS) of scalar perturbations arising from inflation can impact the dark radiation constraints obtained from Cosmic Microwave Background and other cosmological measurements. If inflation produces a non-standard PPS for the initial fluctuations, a fully thermalized light sterile neutrino can be favoured by CMB observations, instead of being strongly disfavoured. In the case of a thermal axion, the constraints on the axion mass are relaxed when the PPS is different from the standard power law.

    ↳ astro-ph.COhep-phJ.Phys.Conf.Ser.(2016)·0 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.