Fri·Aug 7, 2015Friday·August 7, 2015

1. 01*

   Real time correlation functions and the functional renormalisation group

   Jan M. Pawlowski🇩🇪 · Nils Strodthoff🇩🇪

   We put forward a functional renormalisation group approach for the direct computation of real time correlation functions, also applicable at finite temperature and density. We construct a general class of regulators that preserve the space-time symmetries, and allows the computation of correlation functions at complex frequencies. This includes both imaginary time and real time, and allows in particular the use of the plethora of imaginary time results for the computation of real time correlation functions. We also discuss real time computation on the Keldysh contour with general spatial momentum regulators. Both set-ups give access to the general momentum and frequency dependence of correlation functions.

   hep-phhep-thPRD(2015)·116 citations
2. 02*

   On the pentaquark candidates $P_c^{+}(4380)$ and $P_c^{+}(4450)$ within the soliton picture of baryons

   N.N. Scoccola🇦🇷 · D.O. Riska🇺🇸 · Mannque Rho🇫🇷

   Using the bound state version of the topological soliton model for the baryons we show that the existence of a bound (or quasi-bound) $\bar{D}$-soliton state leads to the possibility of having hidden charm pentaquarks with quantum numbers and masses, which are compatible with those of the candidates recently reported by the LHCb experiment. The implications of heavy quark symmetry are elaborated.

   hep-phPRD(2015)·91 citations
3. 03*

   Supersymmetric Dark Matter after LHC Run 1

   E.A. Bagnaschi🇩🇪 · O. Buchmueller🇬🇧 · R. Cavanaugh🇺🇸 · M. Citron🇬🇧 · A. De Roeck🇨🇭 · M.J. Dolan🇺🇸 · J.R. Ellis🇬🇧 · H. Flaecher🇬🇧 · S. Heinemeyer🇪🇸 · G. Isidori🇨🇭 · S. Malik🇬🇧 · D. Martinez Santos🇪🇸 and 4 other authors

   Different mechanisms operate in various regions of the MSSM parameter space to bring the relic density of the lightest neutralino, neutralino_1, assumed here to be the LSP and thus the Dark Matter (DM) particle, into the range allowed by astrophysics and cosmology. These mechanisms include coannihilation with some nearly-degenerate next-to-lightest supersymmetric particle (NLSP) such as the lighter stau (stau_1), stop (stop_1) or chargino (chargino_1), resonant annihilation via direct-channel heavy Higgs bosons H/A, the light Higgs boson h or the Z boson, and enhanced annihilation via a larger Higgsino component of the LSP in the focus-point region. These mechanisms typically select lower-dimensional subspaces in MSSM scenarios such as the CMSSM, NUHM1, NUHM2 and pMSSM10. We analyze how future LHC and direct DM searches can complement each other in the exploration of the different DM mechanisms within these scenarios. We find that the stau_1 coannihilation regions of the CMSSM, NUHM1, NUHM2 can largely be explored at the LHC via searches for missing E_T events and long-lived charged particles, whereas their H/A funnel, focus-point and chargino_1 coannihilation regions can largely be explored by the LZ and Darwin DM direct detection experiments. We find that the dominant DM mechanism in our pMSSM10 analysis is chargino_1 coannihilation: {parts of its parameter space can be explored by the LHC, and a larger portion by future direct DM searches.

   hep-phastro-ph.HEhep-exhep-thEPJC(2015)·143 citations
4. 04*

   Violation of Factorization Theorem in QCD and QED For Non-Light-Like Wilson Line

   Gouranga C. Nayak🇺🇸

   By using path integral formulation of QCD and QED we prove that the factorization theorem is valid for light-like Wilson line but is not valid for non-light-like Wilson line. This conclusion is shown to be consistent with Ward identity and Grammer-Yennie approximation. Hence we find that the factorization theorem is violated in all the previous studies which used the non-light-like Wilson line in the definition of the (transverse momentum dependent) parton distribution function and fragmentation function at high energy colliders.

   hep-phhep-thnucl-th2 citations
5. 05*

   A new radiative neutrino mass generation mechanism with higher dimensional scalar representations and custodial symmetry

   Alfredo Aranda🇲🇽 · Eduardo Peinado🇲🇽

   A new realization for radiative neutrino mass generation is presented. Based on the requirement of tree-level custodial symmetry and the introduction of higher (greater than two) dimensional representations for scalar fields, a specific scenario with a scalar septet is presented that generates neutrino Majorana masses radiatively. This is accomplished through an eleven dimensional operator that requires the addition of several scalar fields and a SU(2) 5-plet of new fermions, together with a Z2 that guarantees the preservation of custodial symmetry. The phenomenology of the setup is rather rich and includes a dark matter candidate

   hep-phPLB(2016)·19 citations
6. 06*

   Putting a Stop to di-Higgs Modifications

   Brian Batell🇨🇭 · Matthew McCullough🇨🇭 · Daniel Stolarski🇨🇭 · Christopher B. Verhaaren🇺🇸

   Pair production of Higgs bosons at hadron colliders is an enticing channel to search for new physics. New colored particles that couple strongly to the Higgs, such as those most often called upon to address the hierarchy problem, provide well motivated examples in which large enhancements of the di-Higgs rate are possible, at least in principle. However, in such scenarios the di-Higgs production rate is tightly correlated with the single Higgs production rate and, since the latter is observed to be SM-like, one generally expects that only modest enhancements in di-Higgs production are allowed by the LHC Run 1 data. We examine the contribution of top squarks (stops) in a simplified supersymmetry model to di-Higgs production and find that this general expectation is indeed borne out. In particular, the allowed deviations are typically small, but there are tuned regions of parameter space where expectations based on EFT arguments break down in which order 100% enhancements to the di-Higgs production rate are possible and are simultaneously consistent with the observed single Higgs production rates. These effects are potentially observable with the high luminosity run of the LHC or at a future hadron collider.

   hep-phhep-exJHEP(2015)·39 citations
7. 07*

   Astrophysical Constraints on Inflationary Dark Matter in the Luminogenesis Model

   Pham Q. Hung🇺🇸 · Kevin J. Ludwick🇺🇸

   The assumption of collisionless cold dark matter on its own cannot reconcile several astrophysical discrepancies (cusp-vs-core problem, missing satellite problem, too-big-to-fail problem). Self-interacting dark matter provides a promising framework for solving all these problems, and self-interaction cross sections are duly constrained in the literature. Following the work of Tulin, Yu, and Zurek [1], we can constrain the dark matter mass and the mass of a light mediator assuming a generic scalar Yukawa-type interaction. In particular, we constrain the strongly coupled inflationary dark matter of the luminogenesis model, a unification model with the gauge group $SU(3{)}_C\times SU(6)\times U(1{)}_Y$, which breaks to the Standard Model with an extra gauge group for dark matter when the inflaton rolls into its true vacuum. The luminogenesis model is additionally subject to constraints on inflation, and we find an upper bound on the scale of symmetry breaking of the inflaton and the decoupling scale $M_1$ of certain representations of the gauge group. We emphasize that the luminogenesis model enables a unique connection between astrophysical constraints, the nature of dark matter, and inflation.

   hep-phastro-ph.CO0 citations
8. 08*

   Decoupling theorem in top productions/decays revisited -- To what extent can we understand it visually?

   Zenro Hioki🇯🇵

   I revisit here the decoupling theorem in top-quark productions/decays, which states that the angular distribution of any final-particle produced in those processes does not depend on any possible nonstandard top-quark decay interactions at their leading order when certain conditions are satisfied. Towards a simple, intuitive and visual understanding of this theorem, I will study to what extent we could explain why such a theorem holds without relying on any specific/detailed calculations.

   hep-phhep-exInt.J.Mod.Phys.A(2016)·2 citations
9. 09*

   Cold Nuclear Matter Effects on Open and Hidden Heavy Flavor Production at the LHC

   R. Vogt🇺🇸

   We discuss a number of cold nuclear matter effects that can modify open heavy flavor and quarkonium production in proton-nucleus collisions and could thus also affect their production in nucleus-nucleus collisions, in addition to hot quark-gluon plasma production. We show some results for $p+$Pb collisions at sqrt s = 5 TeV at the LHC.

   hep-phnucl-th10 citations
10. 10*

    Deflected Anomaly Mediated SUSY Breaking Scenario With General Messenger-Matter Interactions

    Fei Wang🇨🇳

    We propose to introduce general messenger-matter interactions in the deflected anomaly mediated SUSY breaking scenario. The most general form for the resulting soft parameters are derived. New interference terms between the GMSB type and AMSB type contributions are the unique feature of this scenario. Messenger-matter interactions involving sleptons can be used to solve the tachyonic slepton problem and naturally lead to positive slepton masses regardless of the sign of deflection parameter. Besides, due to the new contributions, large $|A_t|$ that will not trigger color-breaking stop VEV are also possible in this scenario, thus can easily give the 125 GeV higgs which was discovered by LHC. This type of deflected AMSB scenario need very few messenger species, thus can avoid possible non-perturbative gauge couplings below the GUT scale ( or Landau pole below the Planck scale ).

    hep-phhep-thPLB(2015)·15 citations
11. 11*

    Neutrino mass hierarchy and precision physics with medium-baseline reactors: Impact of energy-scale and flux-shape uncertainties

    F. Capozzi🇮🇹 · E. Lisi🇮🇹 · A. Marrone (U. of Bari and INFN, Bari)🇮🇹

    Nuclear reactors provide intense sources of electron antineutrinos, characterized by few-MeV energy E and unoscillated spectral shape Phi(E). High-statistics observations of reactor neutrino oscillations over medium-baseline distances L ~ O(50) km would provide unprecedented opportunities to probe both the long-wavelength mass-mixing parameters (delta m^2 and theta_12) and the short-wavelength ones (Delta m^2 and theta_13), together with the subtle interference effects associated with the neutrino mass hierarchy (either normal or inverted). In a given experimental setting - here taken as in the JUNO project for definiteness - the achievable hierarchy sensitivity and parameter accuracy depend not only on the accumulated statistics but also on systematic uncertainties, which include (but are not limited to) the mass-mixing priors and the normalizations of signals and backgrounds. We examine, in addition, the effect of introducing smooth deformations of the detector energy scale, E -> E'(E), and of the reactor flux shape, Phi(E) -> Phi'(E), within reasonable error bands inspired by state-of-the-art estimates. It turns out that energy-scale and flux-shape systematics can noticeably affect the performance of a JUNO-like experiment, both on the hierarchy discrimination and on precision oscillation physics. It is shown that a significant reduction of the assumed energy-scale and flux-shape uncertainties (by, say, a factor of 2) would be highly beneficial to the physics program of medium-baseline reactor projects. Our results also shed some light on the role of the inverse-beta decay threshold, of geoneutrino backgrounds, and of matter effects in the analysis of future reactor oscillation data.

    hep-phPRD(2015)·34 citations
12. 12*

    The angular momentum of two massless fields revisited

    V. Pleitez🇧🇷

    We consider the angular momentum of two massless fields using the Landau's arguments. In particular, we point out the explicit and implicit assumptions made by Landau to obtain the proof that a spin one system cannot decay into two photons. We show also under what conditions the result can be avoided.

    hep-phhep-exhep-th10 citations
13. 13*

    Gamma Lines from Majorana Dark Matter

    Michael Duerr🇩🇪 · Pavel Fileviez Perez🇩🇪 · Juri Smirnov🇩🇪

    We discuss simple models which predict the existence of significant gamma-ray fluxes from dark matter annihilation. In this context the dark matter candidate is a Majorana fermion with velocity-suppressed tree-level annihilation into Standard Model fermions but unsuppressed annihilation into photons. These gamma lines can easily be distinguished from the continuum and provide a possibility to test these models.

    hep-phastro-ph.COhep-exhep-thPRD(2016)·30 citations
14. 14*

    Factorization for radiative heavy quarkonium decays into scalar Glueball

    Ruilin Zhu🇨🇳

    We establish the factorization formula for scalar Glueball production through radiative decays of vector states of heavy quarkonia, e.g. $J/\psi$, $\psi (2S)$ and ${\rm Y}(nS)$, where the Glueball mass is much less than the parent heavy quarkonium mass. The factorization is demonstrated explicitly at one-loop level through the next-to-leading order (NLO) corrections to the hard kernel, the non-relativistic QCD (NRQCD) long-distance matrix element (LDMEs) of the heavy quarkonium, and the light-cone distribution amplitude (LCDA) of scalar Glueball. The factorization provides a comprehensive theoretical approach to investigate Glueball production in the radiative decays of vector states of heavy quarkonia and to determine the physic nature of Glueball. We discuss the scale evolution equation of LCDA for scalar Glueball. In the end, we extract the value of the decay constant of Scalar Glueball from Lattice QCD calculation and analyze the mixing effect among $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$.

    hep-phhep-exJHEP(2015)·14 citations
15. 15*

    The O(\alpha_s^3) Heavy Flavor Contributions to the Charged Current Structure Function xF_3(x,Q^2) at Large Momentum Transfer

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

    We calculate the massive Wilson coefficients for the heavy flavor contributions to the non-singlet charged current deep-inelastic scattering structure function $x{F}_3^{W^{+}}(x,Q^2)+x{F}_3^{W^{-}}(x,Q^2)$ in the asymptotic region $Q^2\gg m^2$ to 3-loop order in Quantum Chromodynamics (QCD) at general values of the Mellin variable $N$ and the momentum fraction $x$. Besides the heavy quark pair production also the single heavy flavor excitation $s\to c$ contributes. Numerical results are presented for the charm quark contributions and consequences on the Gross-Llewellyn Smith sum rule are discussed.

    hep-phhep-exPRD(2015)·49 citations
16. 16*

    Knotty inflation and the dimensionality of spacetime

    Arjun Berera🇬🇧 · Roman V. Buniy🇺🇸 · Thomas W. Kephart🇺🇸 · Heinrich Päs🇩🇪 · João G. Rosa🇵🇹

    We suggest a structure for the vacuum comprised of a network of tightly knotted/linked flux tubes formed in a QCD-like cosmological phase transition and show that such a network can drive cosmological inflation. As the network can be topologically stable only in three space dimensions, this scenario provides a dynamical explanation for the existence of exactly three large spatial dimensions in our Universe.

    hep-phastro-ph.COgr-qchep-thEPJC(2017)·3 citations
17. 17*

    The Importance of Proper Renormalization Scale-Setting for Testing QCD at Colliders

    Xing-Gang Wu🇨🇳 · Sheng-Quan Wang🇨🇳 · Stanley J. Brodsky🇺🇸

    A primary problem for perturbative QCD analyses is how to set the renormalization scale of the QCD running coupling in order to achieve maximally precise fixed-order predictions for physical observables. The Principle of Maximum Conformality (PMC) eliminates the ambiguities associated with the conventional renormalization scale-setting procedure, giving predictions which are independent of the choice of renormalization scheme. The scales of the QCD couplings and the effective number of quark flavors are set order by order in the pQCD series. The PMC has a solid theoretical foundation, satisfying the standard renormalization group invariance and all of the the self-consistency conditions derived from the renormalization group......In this brief report, we summarize the results of our recent PMC applications for a number of collider processes, emphasizing their generality and applicability....... These results demonstrate that the application of the PMC systematically eliminates a major theoretical uncertainty for pQCD predictions, thus increasing the sensitivity of the colliders to possible new physics beyond the Standard Model.

    hep-phhep-exFront.Phys.(Beijing)(2016)·20 citations
18. 18*

    Detector resolution correction for width of intermediate states in three particle decays

    Igor Denisenko🇷🇺 · Igor Boyko🇷🇺

    We propose a method that allows to take into account detector resolution in the partial wave analysis event-by-event fit as a special case. Implementation of the method is discussed and the applicability of the method is studied for the $J/\psi \to K^{\ast \pm }{K}^{\mp }\to K^{+}{K}^{-}{\pi }^0$ and $J/\psi \to K_2(1430{)}^{\pm }{K}^{\mp }\to K^{+}{K}^{-}{\pi }^0$ decays.

    ↳ physics.data-anhep-phnucl-thJINST(2015)·2 citations
19. 19*

    Dark Matter annihilations in halos and high-redshift sources of reionization of the universe

    Vivian Poulin🇫🇷 · Pasquale D. Serpico🇫🇷 · Julien Lesgourgues🇩🇪

    It is well known that annihilations in the homogeneous fluid of dark matter (DM) can leave imprints in the cosmic microwave background (CMB) anisotropy power spectrum. However, the relevance of DM annihilations in halos for cosmological observables is still subject to debate, with previous works reaching different conclusions on this point. Also, all previous studies used a single type of parameterization for the astrophysical reionization, and included no astrophysical source for the heating of the intergalactic medium. In this work, we revisit these problems. When standard approaches are adopted, we find that the ionization fraction does exhibit a very particular (and potentially constraining) pattern, but the currently measurable optical depth to reionization is left almost unchanged: In agreement with the most of the previous literature, for plausible halo models we find that the modification of the signal with respect to the one coming from annihilations in the smooth background is tiny, below cosmic variance within currently allowed parameter space. However, if different and probably more realistic treatments of the astrophysical sources of reionization and heating are adopted, a more pronounced effect of the DM annihilation in halos is possible. We thus conclude that within currently adopted baseline models the impact of the virialised DM structures cannot be uncovered by CMB power spectra measurements, but a larger impact is possible if peculiar models are invoked for the redshift evolution of the DM annihilation signal or different assumptions are made for the astrophysical contributions. A better understanding (both theoretical and observational) of the reionization and temperature history of the universe, notably via the 21 cm signal, seems the most promising way for using halo formation as a tool in DM searches, improving over the sensitivity of current cosmological probes.

    ↳ astro-ph.COastro-ph.HEhep-phJCAP(2015)·52 citations
20. 20*

    Emergence of a new $SU(4)$ symmetry in the baryon spectrum

    M. Denissenya🇦🇹 · L. Ya. Glozman🇦🇹 · M. Pak🇦🇹

    Recently a large degeneracy of $J=1$ mesons, that is larger than the $SU(2{)}_L\times SU(2{)}_R\times U(1{)}_A$ symmetry of the QCD Lagrangian, has been discovered upon truncation of the near-zero modes from the valence quark propagators. It has been found that this degeneracy represents the $SU(4)$ group that includes the chiral rotations as well as the mixing of left- and right-handed quarks. This symmetry group turns out to be a symmetry of confinement in QCD. Consequently, one expects that the same symmetry should persist upon the near-zero mode removal in other hadron sectors as well. It has been shown that indeed the $J=2$ mesons follow the same symmetry pattern upon the low-lying mode elimination. Here we demonstrate the $SU(4)$ symmetry of baryons once the near-zero modes are removed from the quark propagators. We also show a degeneracy of states belonging to different irreducible representations of $SU(4)$. This implies a larger symmetry, that includes $SU(4)$ as a subgroup.

    ↳ hep-lathep-phnucl-thPRD(2015)·40 citations
21. 21*

    Proof of the fundamental BCJ relations for QCD amplitudes

    Leonardo de la Cruz🇩🇪 · Alexander Kniss🇩🇪 · Stefan Weinzierl🇩🇪

    The fundamental BCJ-relation is a linear relation between primitive tree amplitudes with different cyclic orderings. The cyclic orderings differ by the insertion place of one gluon. The coefficients of the fundamental BCJ-relation are linear in the Lorentz invariants $2p_i{p}_j$. The BCJ-relations are well established for pure gluonic amplitudes as well as for amplitudes in $\mathcal{N}=4$ super-Yang-Mills theory. Recently, it has been conjectured that the BCJ-relations hold also for QCD amplitudes. In this paper we give a proof of this conjecture. The proof is valid for massless and massive quarks.

    ↳ hep-thhep-phJHEP(2015)·52 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.