Thu·Oct 13, 2016Thursday·October 13, 2016

1. 01*

   High Energy QCD at NLO: from light-cone wave function to JIMWLK evolution

   Michael Lublinsky🇮🇱 · Yair Mulian🇮🇱

   Soft components of the light cone wave-function of a fast moving projectile hadron is computed in perturbation theory to third order in QCD coupling constant. At this order, the Fock space of the soft modes consists of one-gluon, two-gluon, and a quark-antiquark states. The hard component of the wave-function acts as a non-Abelian background field for the soft modes and is represented by a valence charge distribution that accounts for non-linear density effects in the projectile. When scattered off a dense target, the diagonal element of the S-matrix reveals the Hamiltonian of high energy evolution, the JIMWLK Hamiltonian. This way we provide a new direct derivation of the JIMWLK Hamiltonian at the Next-to-Leading Order.

   hep-phhep-thnucl-thJHEP(2017)·82 citations
2. 02*

   Boosted Dark Matter at Neutrino Experiments

   Lina Necib🇺🇸 · Jarrett Moon🇺🇸 · Taritree Wongjirad🇺🇸 · Janet M. Conrad🇺🇸

   Current and future neutrino experiments can be used to discover dark matter, not only in searches for dark matter annihilating to neutrinos, but also in scenarios where dark matter itself scatters off Standard Model particles in the detector. In this work, we study the sensitivity of different neutrino detectors to a class of models called boosted dark matter, in which a subdominant component of a dark sector acquires a large Lorentz boost today through annihilation of a dominant component in a dark matter-dense region, such as the galactic center or dwarf spheroidal galaxies. This analysis focuses on the sensitivity of different neutrino detectors, specifically the Cherenkov-based Super-K and the future argon-based DUNE to boosted dark matter that scatters off electrons. We study the dependence of the expected limits on the experimental features, such as energy threshold, volume and exposure in the limit of constant scattering amplitude. We highlight experiment-specific features that enable current and future neutrino experiments to be a powerful tool in finding signatures of boosted dark matter.

   hep-phhep-exPRD(2017)·57 citations
3. 03*

   The decay $\eta \to 3\pi$: study of the Dalitz plot and extraction of the quark mass ratio $Q$

   Gilberto Colangelo🇨🇭 · Stefan Lanz🇨🇭 · Heinrich Leutwyler🇨🇭 · Emilie Passemar🇺🇸

   The $\eta \to 3\pi$ amplitude is sensitive to the quark mass difference $m_u-m_d$ and offers a unique way to determine the quark mass ratio $Q^2\equiv (m_s^2-m_{ud}^2)/(m_d^2-m_u^2)$ from experiment. We calculate the amplitude dispersively and fit the KLOE data on the charged mode, varying the subtraction constants in the range allowed by chiral perturbation theory. The parameter-free predictions obtained for the neutral Dalitz plot and the neutral-to-charged branching ratio are in excellent agreement with experiment. Our representation of the transition amplitude implies $Q=22.0\pm 0.7$.

   hep-phhep-exhep-latPRL(2017)·77 citations
4. 04*

   Nucleon parton distributions in a light-front quark model

   Thomas Gutsche🇩🇪 · Valery E. Lyubovitskij🇩🇪 · Ivan Schmidt🇨🇱

   Continuing with our analysis of parton distributions in the nucleon, we extend our light-front quark model in order to obtain both the helicity independent and helicity dependent parton distributions, analytically matching the results of global fits at the initial scale $\mu \sim 1$ GeV, and which also contain the correct Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution. We also calculate the transverse parton, Wigner and Husimi distributions from a unified point of view, using our light-front wave functions and expressing them in terms of the parton distributions $q_v(x)$ and $\delta q_v(x)$. Our results are very relevant for the current and future program of the COMPASS experiment at SPS (CERN).

   hep-phEPJC(2017)·40 citations
5. 05*

   Reviving trinification models through an ${\mathrm{E}}_6$-extended supersymmetric GUT

   José E. Camargo-Molina🇸🇪 · António P. Morais🇵🇹 · Astrid Ordell🇸🇪 · Roman Pasechnik🇸🇪 · Marco O. P. Sampaio🇵🇹 · Jonas Wessén🇸🇪

   We present a supersymmetric (SUSY) model based on trinification $[\mathrm{SU}(3){]}^3$ and family $\mathrm{SU}(3{)}_{\mathrm{F}}$ symmetries embedded into a maximal subgroup of ${\mathrm{E}}_8$, where the sectors of light Higgs bosons and leptons are unified into a single chiral supermultiplet. The common origin of gauge trinification and of the family symmetry from ${\mathrm{E}}_8$ separates the model from other trinification-based GUTs, as it protects, in particular, the Standard Model fermions from gaining mass until the electroweak symmetry is broken. Furthermore, it allows us to break the trinification symmetry via vacuum expectation values in $\mathrm{SU}(3)$-adjoint scalars down to a left-right symmetric theory. Simultaneously, it ensures the unification of the gauge and Yukawa couplings as well as proton stability. Although the low-energy regime (e.g. mass hierarchies in the scalar sector determined by a soft SUSY-breaking mechanism) is yet to be established, these features are one key to revive the once very popular trinification-based GUTs.

   hep-phhep-thPRD(2017)·30 citations
6. 06*

   Probing BFKL dynamics in Mueller-Navelet jet production at the LHC

   B. Ducloué🇫🇮 · L. Szymanowski🇵🇱 · S. Wallon🇫🇷

   We review the results of our studies on the production of two jets with a large interval of rapidity at hadron colliders, which was proposed by Mueller and Navelet as a possible test of the high energy dynamics of QCD, within the next-to-leading logarithm framework. The application of the Brodsky-Lepage-Mackenzie procedure to fix the renormalization scale leads to a very good description of the available CMS data at the LHC for the azimuthal correlations of the jets. We show that the inclusion of next-to-leading order corrections to the jet vertex significantly reduces the importance of energy-momentum non-conservation which is inherent to the BFKL approach, for an asymmetric jet configuration.

   hep-ph1 citation
7. 07*

   Plasmon mass scale in classical nonequilibrium gauge theory

   Tuomas Lappi🇫🇮 · Jarkko Peuron🇫🇮

   Classical lattice Yang-Mills calculations provide a good way to understand different nonequilibrium phenomena in nonperturbatively overoccupied systems. Above the Debye scale the classical theory can be matched smoothly to kinetic theory. The aim of this work is to study the limits of this quasiparticle picture by determining the plasmon mass in classical real time Yang-Mills theory on a lattice in 3 spatial dimensions. We compare three methods to determine the plasmon mass: a hard thermal loop expression in terms of the particle distribution, an effective dispersion relation constructed from fields and their time derivatives, and by measuring oscillations between electric and magnetic field modes after artificially introducing a homogeneous color electric field. We find that a version of the dispersion relation that uses electric fields and their time derivatives agrees with the other methods within 50%.

   hep-phhep-latnucl-thPRD(2017)·16 citations
8. 08*

   Two-loop $gg\to Hg$ amplitude mediated by a nearly massless quark

   Kirill Melnikov🇩🇪 · Lorenzo Tancredi🇩🇪 · Christopher Wever🇩🇪

   We analytically compute the two-loop scattering amplitude $gg\to Hg$ assuming that the mass of the quark, that mediates the ggH interaction, is vanishingly small. Our computation provides an important ingredient required to improve the theoretical description of the top-bottom interference effect in Higgs boson production in gluon fusion, and to elucidate its impact on the Higgs boson transverse momentum distribution.

   hep-phJHEP(2016)·75 citations
9. 09*

   Anticipating Non-Resonant New Physics in Dilepton Angular Spectra at the LHC

   Nirmal Raj🇺🇸

   At the LHC, dileptonic events may turn up new physics interacting with quarks and leptons. The poster child for this scenario is a resonant $Z^{\prime }$, much anticipated in ${\ell }^{+}{\ell }^{-}$ invariant mass spectra. However, angular spectra of dileptons may play an equal or stronger role in discovering a non-resonant species. This paper avails of their LHC measurements to corner the couplings and masses of leptoquarks (LQs), that can mediate $q\bar{q}\to {\ell }^{+}{\ell }^{-}$ in the $t$-channel and dramatically alter Standard Model angular spectra. Also derived are constraints from alterations to $m_{\ell \ell }$ distributions. These dilepton probes, exploiting the high rates and small uncertainties of the Drell-Yan process, rival or outdo dedicated LHC searches for LQs in single and pair production modes. The couplings of LQs with electronic interactions are best bound today by low-energy measurements of atomic parity violation, but can be probed better by ${\ell }^{+}{\ell }^{-}$ measurements in the high luminosity runs of the LHC, with the angular spectra leading the way. This work also advocates the experimental presentation of boost-invariant angular asymmetries that vanish in the SM.

   hep-phPRD(2017)·66 citations
10. 10*

    Nuclear axial current operators to fourth order in chiral effective field theory

    H. Krebs🇩🇪 · E. Epelbaum🇩🇪 · U.-G. Meißner🇩🇪

    We present the complete derivation of the nuclear axial charge and current operators as well as the pseudoscalar operators to fourth order in the chiral expansion relative to the dominant one-body contribution using the method of unitary transformation. We demonstrate that the unitary ambiguity in the resulting operators can be eliminated by the requirement of renormalizability and by matching of the pion-pole contributions to the nuclear forces. We give expressions for the renormalized single-, two- and three-nucleon contributions to the charge and current operators and pseudoscalar operators including the relevant relativistic corrections. We also verify explicitly the validity of the continuity equation.

    ↳ nucl-thhep-phAnnals Phys.(2017)·109 citations
11. 11*

    The Effect of Quantum Fluctuations in the High-Energy Cold Nuclear Equation of State and in Compact Star Observables

    Péter Pósfay🇭🇺 · Gergely Gábor Barnaföldi🇭🇺 · Antal Jakovác🇭🇺

    We present a novel technique to obtain exact equation of state (EoS) by the Functional Renormalization Group (FRG) method, using the expansion of the effective potential in a base of harmonic functions at finite chemical potential. Within this theoretical framework we determined the equation of state and the phase diagram of a simple model of massless fermions coupled to scalars through Yukawa-coupling at the zero-temperature limit. We compared our results to the 1-loop and the mean field approximation of the same model and other high-density nuclear matter equation of states. We found a $10-20\%$ difference between these approximations. As an application, we used our exact, FRG-based equation of states to test the effect of the quantum fluctuations in superdense nuclear matter of a compact astrophysical object for the first time. We calculated the mass-radius relation for a compact star using the Tolmann-Oppenheimer-Volkov equation and observed a $\sim 5\%$ effect in compact star observables due to quantum fluctuations.

    ↳ nucl-thhep-phPRC(2018)·8 citations
12. 12*

    Updated Lattice Results for Parton Distributions

    Constantia Alexandrou🇨🇾 · Krzysztof Cichy🇩🇪 · Martha Constantinou🇺🇸 · Kyriakos Hadjiyiannakou🇨🇾 · Karl Jansen🇩🇪 · Fernanda Steffens🇩🇪 · Christian Wiese🇩🇪

    We provide an analysis of the x-dependence of the bare unpolarized, helicity and transversity iso-vector parton distribution functions (PDFs) from lattice calculations employing (maximally) twisted mass fermions. The x-dependence of the calculated PDFs resembles the one of the phenomenological parameterizations, a feature that makes this approach very promising. Furthermore, we apply momentum smearing for the relevant matrix elements to compute the lattice PDFs and find a large improvement factor when compared to conventional Gaussian smearing. This allows us to extend the lattice computation of the distributions to higher values of the nucleon momentum, which is essential for the prospects of a reliable extraction of the PDFs in the future.

    ↳ hep-lathep-phPRD(2017)·183 citations
13. 13*

    Gravitational waves at interferometer scales and primordial black holes in axion inflation

    Juan Garcia-Bellido🇪🇸 · Marco Peloso🇺🇸 · Caner Unal🇺🇸

    We study the prospects of detection at terrestrial and space interferometers, as well as at pulsar timing array experiments, of a stochastic gravitational wave background which can be produced in models of axion inflation. This potential signal, and the development of these experiments, open a new window on inflation on scales much smaller than those currently probed with Cosmic Microwave Background and Large Scale Structure measurements. The sourced signal generated in axion inflation is an ideal candidate for such searches, since it naturally grows at small scales, and it has specific properties (chirality and non-gaussianity) that can distinguish it from an astrophysical background. We study under which conditions such a signal can be produced at an observable level, without the simultaneous overproduction of scalar perturbations in excess of what is allowed by the primordial black hole limits. We also explore the possibility that scalar perturbations generated in a modified version of this model may provide a distribution of primordial black holes compatible with the current bounds, that can act as a seeds of the present black holes in the universe.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2016)·300 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.