Wed·Nov 4, 2015Wednesday·November 4, 2015

1. 01*

   Model Independent Analysis of the Proton Magnetic Radius

   Joydeep Roy🇺🇸 · Zachary Epstein🇺🇸 · Gil Paz🇺🇸

   The proton is a fundamental constituent of matter. It is an extended object with finite size that can be inferred with some degree of accuracy from several measurements. Using constraints from the analytic behavior of the form factors we present here a model-independent study that extracts the proton magnetic radius from scattering data. From electron-proton scattering data we find $r_M^p=0.91_{-0.06}^{+0.03}\pm 0.02$ fm. When we include electron-neutron scattering data and $\pi \pi$ data, we find $r_M^p=0.87_{-0.05}^{+0.04}\pm 0.01$ fm and $r_M^p=0.87_{-0.02}^{+0.02}$ fm respectively. The neutron magnetic radius is extracted as $r_M^n=0.89_{-0.03}^{+0.03}$ fm combining all three data sets.

   hep-ph0 citations
2. 02*

   Analysis of mechanisms that could contribute to the neutrinoless double-beta decay

   Mihai Horoi🇺🇸 · Andrei Neacsu🇺🇸

   Neutrinoless double-beta decay, if observed, would signal physics beyond the Standard Model that could be discovered at energies significantly lower than those at which the relevant degrees of freedom could be excited. Therefore, it could be challenging to further use the neutrinoless double-beta decay observations to distinguish between many beyond Standard Model mechanisms contributing to this process. Accurate nuclear structure calculations of the nuclear matrix elements necessary to analyze the decay rates could be helpful to narrow down the list of contributing mechanisms, and to better identify the more exotic properties of the neutrinos. We investigate the information one can get from the angular and energy distribution of the emitted electron assuming that the right-handed currents exist. For the analysis of these distributions we calculate the necessary nuclear matrix elements using shell model techniques.

   hep-phnucl-thPRD(2016)·38 citations
3. 03*

   Global Constraints on a Heavy Neutrino

   André de Gouvêa🇺🇸 · Andrew Kobach🇺🇸

   We estimate constraints on the existence of a heavy, mostly sterile neutrino with mass between 10 eV and 1 TeV. We improve upon previous analyses by performing a global combination and expanding the experimental inputs to simultaneously include tests for lepton universality, lepton-flavor-violating processes, electroweak precision data, dipole moments, and neutrinoless double beta decay. Assuming the heavy neutrino and its decay products are invisible to detection, we further include, in a self-consistent manner, constraints from direct kinematic searches, the kinematics of muon decay, cosmology, and neutrino oscillations, in order to estimate constraints on the values of $|U_{e4}{|}^2$, $|U_{\mu 4}{|}^2$, and $|U_{\tau 4}{|}^2$.

   hep-phPRD(2016)·203 citations
4. 04*

   SUSY Higgs Mass and Collider Signals with a Hidden Valley

   Yuichiro Nakai🇺🇸 · Matthew Reece🇺🇸 · Ryosuke Sato🇯🇵

   We propose a framework of supersymmetric extensions of the Standard Model that can ameliorate both the SUSY Higgs mass problem and the missing superpartner problem. New vectorlike matter fields couple to the Higgs and provide new loop contributions to its mass. New Yukawa couplings are sizable and large supersymmetry breaking is not needed to lift the Higgs mass. To avoid a Landau pole for the new Yukawa couplings, these fields are charged under a new gauge group, which confines and leads to a Hidden Valley-like phenomenology. The Hidden Valley sector is almost supersymmetric and ordinary sparticles decay to exotic new states which decay back to Standard Model particles and gravitinos with reduced missing energy. We construct a simplified model to simulate this scenario and find a viable parameter space of specific benchmark models which ameliorates both of the major phenomenological problems with supersymmetry.

   hep-phJHEP(2016)·17 citations
5. 05*

   Condensates in Relativistic Scalar Theories

   Guy D. Moore🇩🇪

   Scalar field theory with large infrared initial occupancy develops very large deep-infrared occupancy, which locally resembles a Bose-Einstein condensate. We study the structure and spatial coherence of this condensate. The O(N) symmetric theory with N>1 is qualitatively different than N=1. We explain the thermodynamical reason why, for N>1, the condensate locally carries nearly maximal conserved charge density. We also show how this property impedes the condensate's decay, and we show that it prevents the condensate from ever becoming fully spatially homogeneous. For N <= 4 the condensate can carry topological defects, but these do not appear to control the large-k tail in its power spectrum, which is the same for N=8 where there are no topological defects.

   hep-phPRD(2016)·34 citations
6. 06*

   A Geometric Formulation of Higgs Effective Field Theory: Measuring the Curvature of Scalar Field Space

   Rodrigo Alonso🇺🇸 · Elizabeth E. Jenkins🇺🇸 · Aneesh V. Manohar🇺🇸

   A geometric formulation of Higgs Effective Field Theory (HEFT) is presented. Experimental observables are given in terms of geometric invariants of the scalar sigma model sector such as the curvature of the scalar field manifold $\mathcal{M}$. We show how the curvature can be measured experimentally via Higgs cross-sections, $W_L$ scattering, and the $S$ parameter. The one-loop action of HEFT is given in terms of geometric invariants of $\mathcal{M}$. The distinction between the Standard Model (SM) and HEFT is whether $\mathcal{M}$ is flat or curved, not whether the scalars transform linearly or non-linearly under the electroweak group.

   hep-phPLB(2016)·187 citations
7. 07*

   Nuclear geometry effect and transport coefficient in semi-inclusive lepton-production of hadrons off nuclei

   Na Liu🇨🇳 · Wen-Dan Miao🇨🇳 · Li-Hua Song🇨🇳 · Chun-Gui Duan🇨🇳

   Hadron production in semi-inclusive deep-inelastic scattering of leptons from nuclei is an ideal tool to determine and constrain the transport coefficient in cold nuclear matter. The leading-order computations for hadron multiplicity ratios are performed by means of the SW quenching weights and the analytic parameterizations of quenching weights based on BDMPS formalism. The theoretical results are compared to the HERMES positively charged pions production data with the quarks hadronization occurring outside the nucleus. With considering the nuclear geometry effect on hadron production, our predictions are in good agreement with the experimental measurements. The extracted transport parameter from the global fit is shown to be $\hat{q}=0.74\pm 0.03Ge{V}^2/fm$ for the SW quenching weight without the finite energy corrections. As for the analytic parameterization of BDMPS quenching weight without the quark energy E dependence, the computed transport coefficient is $\hat{q}=0.20\pm 0.02Ge{V}^2/fm$. It is found that the nuclear geometry effect has a significant impact on the transport coefficient in cold nuclear matter. It is necessary to consider the detailed nuclear geometry in studying the semi-inclusive hadron production in deep inelastic scattering on nuclear targets.

   hep-phPLB(2015)·11 citations
8. 08*

   Jet quenching in high-energy heavy-ion collisions

   Guang-You Qin🇨🇳 · Xin-Nian Wang🇨🇳

   Jet quenching in high-energy heavy-ion collisions can be used to probe properties of hot and dense quark-gluon plasma. We provide a brief introduction to the concept and framework for the study of jet quenching. Different approaches and implementation of multiple scattering and parton energy loss are discussed. Recent progresses in the theoretical and phenomenological studies of jet quenching in heavy-ion collisions at RHIC and LHC are reviewed.

   hep-phnucl-exnucl-thIJMPE(2015)·443 citations
9. 09*

   Non-QCD contributions to top-pair production near threshold

   Martin Beneke🇩🇪 · Andreas Maier🇬🇧 · Jan Piclum🇨🇭 · Thomas Rauh🇩🇪

   The threshold scan of top pair production at a future lepton collider allows to determine several Standard Model parameters with very high precision. The recent completion of the third-order QCD corrections to the inclusive top-pair production cross section demonstrated that strong dynamics are under control. We investigate effects from P-wave production and Higgs contributions at third order and from QED and the nonresonant production of the physical $W^{+}{W}^{-}b\bar{b}$ final state at first order. We discuss the sensitivity of the cross section to the top mass, width and Yukawa coupling as well as to the strong coupling.

   hep-phPoS(2015)·4 citations
10. 10*

    Detection of supernova neutrinos at spallation neutron sources

    Ming-Yang Huang🇨🇳 · Xin-Heng Guo🇨🇳 · Bing-Lin Young🇺🇸

    After considering the supernova shock effects, the Mikheyev-Smirnov-Wolfenstein effects, the neutrino collective effects, and the Earth matter effects, the detection of supernova neutrinos at China Spallation Neutron Sources is studied and the event numbers of different flavor supernova neutrinos observed through various reaction channels are calculated with the neutrino energy spectra described by the Fermi-Dirac distribution and "beta fit" distribution respectively. Furthermore, the numerical calculation method of supernova neutrino detection on the Earth is applied to some other spallation neutron sources, and the total event numbers of supernova neutrinos observed through different reactions channels are given.

    hep-phCPC(2016)·4 citations
11. 11*

    Calibration of the Top-Quark Monte-Carlo Mass

    Jan Kieseler🇩🇪 · Katerina Lipka🇩🇪 · Sven-Olaf Moch🇩🇪

    We present a method to establish experimentally the relation between the top-quark mass $m_t^{MC}$ as implemented in Monte-Carlo generators and the Lagrangian mass parameter $m_t$ in a theoretically well-defined renormalization scheme. We propose a simultaneous fit of $m_t^{MC}$ and an observable sensitive to $m_t$, which does not rely on any prior assumptions about the relation between $m_t$ and $m_t^{MC}$. The measured observable is independent of $m_t^{MC}$ and can be used subsequently for a determination of $m_t$. The analysis strategy is illustrated with examples for the extraction of $m_t$ from inclusive and differential cross sections for hadro-production of top-quarks.

    hep-phhep-exPRL(2016)·51 citations
12. 12*

    A study of multi-jet production in association with an electroweak vector boson

    Rikkert Frederix🇩🇪 · Stefano Frixione🇮🇹 · Andreas Papaefstathiou🇨🇭 · Stefan Prestel🇺🇸 · Paolo Torrielli🇮🇹

    We consider the production of a single $Z$ or $W$ boson in association with jets at the LHC. We compute the corresponding cross sections by matching NLO QCD predictions with the Herwig++ and Pythia8 parton showers, and by merging all of the underlying matrix elements with up to two light partons at the Born level. We compare our results with several 7-TeV measurements by the ATLAS and CMS collaborations, and overall we find a good agreement between theory and data.

    hep-phJHEP(2016)·28 citations
13. 13*

    Searches of exotic Higgs bosons in general mass spectra of the Georgi-Machacek model at the LHC

    Cheng-Wei Chiang🇹🇼 · An-Li Kuo🇹🇼 · Toshifumi Yamada🇰🇷

    We derive the most general sets of viable mass spectra of the exotic Higgs bosons in the Georgi-Machacek model that are consistent with the theoretical constraints of vacuum stability and perturbative unitarity and the experimental constraints of electroweak precision observables, $Zb\bar{b}$ coupling and Higgs boson signal strengths. Branching ratios of various cascade decay channels of the doubly-charged Higgs boson in the $5$ representation, the singly-charged Higgs boson in $3$, and the singlet Higgs boson are further computed. As one of the most promising channels for discovering the model, we study the prospects for detecting the doubly-charged Higgs boson that is produced via the vector boson fusion process and decays into final states containing a pair of same-sign leptons at the 14-TeV LHC and a 100-TeV future $pp$ collider. For this purpose, we evaluate acceptance times efficiency for signals of the doubly-charged Higgs boson with general viable mass spectra and compare it with the standard model background estimates.

    hep-phJHEP(2016)·61 citations
14. 14*

    Compositeness of Hadrons and Near-Threshold Dynamics

    Tetsuo Hyodo🇯🇵

    We present the recent developments in the studies of the structure of hadron resonances, focusing on the compositeness in terms of the hadronic degrees of freedom. We discuss the model dependence of the compositeness, and show that the structure of the near-threshold bound states and resonances is model-independently determined. The applications to various hadrons are summarized.

    hep-phnucl-thJPS Conf.Proc.(2016)·1 citation
15. 15*

    Observability of s-channel Heavy Charged Higgs at LHC Using Top Tagging Technique

    Majid Hashemi🇮🇷 · Gholamhossein Haghighat🇮🇷

    In this paper, the question of observability of a heavy charged Higgs in the mass range 400 GeV < mH < 1000 GeV, is addressed. The production process is set to pp -> H+ -> tb at 14 TeV LHC. The analysis benefits from top tagging technique which is based on finding a fat jet as a result of the boosted top quark decay in signal events. A detailed hadron level analysis is performed and selection efficiencies are presented with different charged Higgs mass hypotheses. Finally running toy experiments and using pseudo-data, a fit over signal plus background distributions is performed to assess possibility of reconstructing the charged Higgs peak and its invariant mass measurement. It is shown that the charged Higgs mass can well be reconstructed in the mass range 500 GeV to 1 TeV, with a signal significance which depends on tanbeta. Eventually 5sigma discovery and 95% C.L. exclusion contours are also provided.

    hep-phJHEP(2016)·3 citations
16. 16*

    Neutrino processes $\nu \bar{\nu }\to e^{-}{e}^{+}$ and $\nu \to \nu e^{-}{e}^{+}$ in a strong magnetic field

    A.V. Kuznetsov🇷🇺 · D.A. Rumyantsev (Yaroslavl State P.G. Demidov University, Russia)🇷🇺 · V.N. Savin (Yaroslavl Higher Military School of Air Defence, Russia)🇷🇺

    The processes of neutrino production of electron-positron pairs, $\nu \bar{\nu }\to e^{-}{e}^{+}$ and $\nu \to \nu e^{-}{e}^{+}$, in a magnetic field of arbitrary strength, where electrons and positrons can be created in the states corresponding to excited Landau levels, are analysed. The results can be applied for calculating the efficiency of the electron-positron plasma production by neutrinos in the conditions of the Kerr black hole accretion disc considered by experts as the most possible source of a short cosmological gamma burst.

    hep-phJ.Phys.Conf.Ser.(2016)·2 citations
17. 17*

    Di-boson Production beyond NLO QCD and Anomalous Couplings

    F. Campanario🇩🇪 · M. Rauch🇩🇪 · R. Roth🇩🇪 · S. Sapeta🇨🇭 · D. Zeppenfeld🇩🇪

    In these proceedings, we review results for several di-boson production processes beyond NLO QCD at high transverse momenta using the VBFNLO Monte-Carlo program together with the LOOPSIM method. Additionally, we show for the WZ production process how higher order QCD corrections can resemble anomalous coupling effects.

    hep-phhep-exActa Phys.Polon.B(2015)·0 citations
18. 18*

    Wigner Distributions and Orbital Angular Momentum of Quarks and Gluons

    Asmita Mukherjee

    We present a recent calculation of the Wigner distributions of quarks and gluons in a perturbative model. We also present the results for the orbital angular momentum and the spin-orbit correlations.

    hep-phPoS(2015)·2 citations
19. 19*

    Asymmetries and observables for ${\Lambda }_b\to \Lambda {\ell }^{+}{\ell }^{-}$

    Girish Kumar🇮🇳 · Namit Mahajan🇮🇳

    The semi-leptonic baryonic $b\to s$ decay, ${\Lambda }_b\to \Lambda {\ell }^{+}{\ell }^{-}$, has been studied and new angular observables and asymmetries have been proposed which can test the presence of new physics beyond the standard model.

    hep-phhep-ex12 citations
20. 20*

    The use of low temperature detectors for direct measurements of the mass of the electron neutrino

    Angelo Nucciotti🇮🇹

    Recent years have witnessed many exciting breakthroughs in neutrino physics. The detection of neutrino oscillations has proved that neutrinos are massive particles but the assessment of their absolute mass scale is still an outstanding challenge in today particle physics and cosmology. Since low temperature detectors were first proposed for neutrino physics experiments in 1984, there have been tremendous technical progresses: today this technique offers the high energy resolution and scalability required to perform competitive experiments challenging the lowest electron neutrino masses. This paper reviews the thirty-year effort aimed at realizing a calorimetric measurements with sub-eV neutrino mass sensitivity using low temperature detectors.

    hep-phphysics.ins-detAdv.High Energy Phys.(2016)·42 citations
21. 21*

    Large BR(h->tau mu) in the MSSM?

    Daniel Aloni🇮🇱 · Yosef Nir🇮🇱 · Emmanuel Stamou🇮🇱

    We study how large the rate of the lepton-flavor violating Higgs decay h->tau mu can be in the (R-parity conserving) MSSM. We make no assumptions, such as universality or alignment, about the flavor structure of the MSSM. We only assume that all couplings and, in particular, the trilinear scalar ones, are perturbative. We take into account lower bounds on the bino and slepton masses from tau->mu gamma and h->gamma gamma as well as upper bounds on the trilinear scalar couplings from the requirement that the global minimum is not charge breaking. We find that in highly fine-tuned regions of parameter space, the ratio BR(h->tau mu)/BR(h->tau tau) can be enhanced by about three orders of magnitude above the estimate from naive dimensional analysis, but still about two orders of magnitude below the present bound. Thus, if h->tau mu is experimentally established to be close to present bounds, the MSSM will be excluded.

    hep-phJHEP(2016)·50 citations
22. 22*

    Fitting Higgs Data with Nonlinear Effective Theory

    G. Buchalla🇩🇪 · O. Cata🇩🇪 · A. Celis🇩🇪 · C. Krause🇩🇪

    In a recent paper we showed that the electroweak chiral Lagrangian at leading order is equivalent to the conventional $\kappa$ formalism used by ATLAS and CMS to test Higgs anomalous couplings. Here we apply this fact to fit the latest Higgs data. The new aspect of our analysis is a systematic interpretation of the fit parameters within an EFT. Concentrating on the processes of Higgs production and decay that have been measured so far, six parameters turn out to be relevant: $c_V$, $c_t$, $c_b$, $c_{\tau }$, $c_{\gamma \gamma }$, $c_{gg}$. A global Bayesian fit is then performed with the result: $c_V=0.98\pm 0.09$, $c_t=1.34\pm 0.19$, $c_b=0.78\pm 0.18$, $c_{\tau }=0.92\pm 0.14$, $c_{\gamma \gamma }=-0.24\pm 0.37$, $c_{gg}=-0.30\pm 0.17$. Additionally, we show how this leading-order parametrization can be generalized to next-to-leading order, thus improving the $\kappa$ formalism systematically. The differences with a linear EFT analysis including operators of dimension six are also discussed. One of the main conclusions of our analysis is that since the conventional $\kappa$ formalism can be properly justified within a QFT framework, it should continue to play a central role in analyzing and interpreting Higgs data.

    hep-phEPJC(2016)·85 citations
23. 23*

    Higgs boson production and decay in 5D warped models

    Mariana Frank🇨🇦 · Nima Pourtolami🇨🇦 · Manuel Toharia🇨🇦

    We calculate the production and decay rates of the Higgs boson at the LHC in the context of general 5 dimensional (5D) warped scenarios with a spacetime background modified from the usual $Ad{S}_5$, with SM fields propagating in the bulk. We extend previous work by considering the full flavor structure of the SM, and thus including all possible flavor effects coming from mixings with heavy fermions. We proceed in three different ways, first by only including two complete Kaluza-Klein (KK) levels ($15\times 15$ fermion mass matrices), then including three complete KK levels ($21\times 21$ fermion mass matrices) and finally we compare with the effect of including the infinite (full) KK towers. We present numerical results for the Higgs production cross section via gluon fusion and Higgs decay branching fractions in both the modified metric scenario and in the usual Randall-Sundrum metric scenario.

    hep-phhep-thPRD(2016)·3 citations
24. 24*

    Analytical study of Yang-Mills theory in the infrared from first principles

    Fabio Siringo🇮🇹

    Pure Yang-Mills SU(N) theory is studied in the Landau gauge and four dimensional space. While leaving the original Lagrangian unmodified, a double perturbative expansion is devised, based on a massive free-particle propagator. In dimensional regularization, all diverging mass terms cancel exactly in the double expansion, without the need to include mass counterterms that would spoil the symmetry of the Lagrangian. No free parameters are included that were not in the original theory, yielding a fully analytical approach from first principles. The expansion is safe in the infrared and is equivalent to the standard perturbation theory in the UV. At one-loop, explicit analytical expressions are given for the propagators and the running coupling and are found in excellent agreement with the data of lattice simulations. A universal scaling property is predicted for the inverse propagators and shown to be satisfied by the lattice data. Higher loops are found to be negligible in the infrared below 300 MeV where the coupling becomes small and the one-loop approximation is under full control.

    hep-phhep-lathep-thNPB(2016)·82 citations
25. 25*

    Nonthermal dark matter models and signals

    Hiroshi Okada🇹🇼 · Yuta Orikasa🇰🇷 · Takashi Toma🇫🇷

    Many experiments exploring weakly interacting massive particles (WIMPs) such as direct, indirect and collider searches have been carried out until now. However, a clear signal of a WIMP has not been found yet and it makes us to suspect that WIMPs are questionable as a dark matter candidate. Taking into account this situation, we propose two models in which dark matter relic density is produced by decay of a metastable particle. In the first model, the metastable particle is a feebly interacting massive particle, which is the so-called FIMP produced by freeze-in mechanism in the early universe. In the second model, the decaying particle is thermally produced the same as the usual WIMP. However decay of the particle into dark matter is led by a higher dimensional operator. As a phenomenologically interesting feature of nonthermal dark matter discussed in this paper, a strong sharp gamma-ray emission as an indirect detection signal occurs due to internal bremsstrahlung, although some parameter space has already been ruled out by this process. Moreover combining other experimental and theoretical constraints such as dark matter relic density, big bang nucleosynthesis, collider, gamma-rays and perturbativity of couplings, we discuss the two nonthermal DM models.

    hep-phPRD(2016)·21 citations
26. 26*

    Bound-free pair production in heavy-ion collisions at high energies

    R. Schicker (Phys. Inst., Heidelberg)🇩🇪

    The electromagnetic process of bound-free electron pair production in heavy-ion collisions at high energies is reviewed. The importance of this process for producing secondary beams is outlined. Single free electron pair production is presented, and the bound-free pair production process is introduced. Double pair production is discussed, and an estimate of the bound-free pair constrained photon-photon luminosity is given.

    hep-ph3 citations
27. 27*

    Bounds on very low reheating scenarios after Planck

    P.F. de Salas🇪🇸 · M. Lattanzi🇮🇹 · G. Mangano🇮🇹 · G. Miele🇮🇹 · S. Pastor🇪🇸 · O. Pisanti🇮🇹

    We consider the case of very low reheating scenarios ($T_{\mathrm{RH}}\sim \mathcal{O}(\mathrm{MeV})$) with a better calculation of the production of the relic neutrino background (with three-flavor oscillations). At 95% confidence level, a lower bound on the reheating temperature $T_{\mathrm{RH}}>4.1$ MeV is obtained from Big Bang Nucleosynthesis, while $T_{\mathrm{RH}}>4.3$ MeV from Planck data for very light ($\sum m_i=0.06$ eV) neutrinos. If neutrino masses are allowed to vary, Planck data yield $T_{\mathrm{RH}}>4.7$ MeV, the most stringent bound on the reheating temperature to date. Neutrino masses as large as 1 eV are possible for very low reheating temperatures.

    ↳ astro-ph.COhep-phPRD(2015)·401 citations
28. 28*

    Gamma Rays, Electrons, Hard X-Rays, and the Central Parsec of the Milky Way

    Matthew D. Kistler (KIPAC, Stanford, SLAC)🇺🇸

    The complex interplay of processes at the Galactic Center is at the heart of numerous past, present, and (likely) future mysteries. We aim at a more complete understanding of how spectra extending to >10 TeV result. We first construct a simplified model to account for the peculiar energy and angular dependence of the intense central parsec photon field. This allows for calculating anisotropic inverse Compton scattering and mapping gamma-ray extinction due to gamma gamma -> e^+ e^- attenuation. Coupling these with a method for evolving electron spectra, we examine several clear and present excesses, including the diffuse hard X-rays seen by NuSTAR and GeV gamma rays by Fermi. We address further applications to cosmic rays, dark matter, neutrinos, and gamma rays from the Center and beyond.

    ↳ astro-ph.HEastro-ph.GAhep-ph10 citations
29. 29*

    The origin of IceCube's neutrinos: Cosmic ray accelerators embedded in star forming calorimeters

    E. Waxman🇮🇱

    The IceCube collaboration reports a detection of extra-terrestrial neutrinos. The isotropy and flavor content of the signal, and the coincidence, within current uncertainties, of the 50 TeV to 2 PeV flux and the spectrum with the Waxman-Bahcall bound, suggest a cosmological origin of the neutrinos, related to the sources of ultra-high energy, $>10^{10}$ GeV, cosmic-rays (UHECR). The most natural explanation of the UHECR and neutrino signals is that both are produced by the same population of cosmological sources, producing CRs (likely protons) at a similar rate, $E^{2}d\dot{n}/dE\propto E^0$, over the [$1$ PeV,$10^{11}$ GeV] energy range, and residing in "calorimetric" environments, like galaxies with high star formation rate, in which $E/Z<100$ PeV CRs lose much of their energy to pion production. A tenfold increase in the effective mass of the detector at $\gtrsim 100$ TeV is required in order to significantly improve the accuracy of current measurements, to enable the detection of a few bright nearby starburst "calorimeters", and to open the possibility of identifying the CR sources embedded within the calorimeters, by associating neutrinos with photons accompanying transient events responsible for their generation. Source identification and a large neutrino sample may enable one to use astrophysical neutrinos to constrain new physics models.

    ↳ astro-ph.HEhep-ph29 citations
30. 30*

    Maximal abelian and Curci-Ferrari gauges in momentum subtraction at three loops

    J.M. Bell🇬🇧 · J.A. Gracey🇬🇧

    The vertex structure of QCD fixed in the maximal abelian gauge (MAG) and Curci-Ferrari gauge is analysed at two loops at the fully symmetric point for the 3-point functions corresponding to the three momentum subtraction (MOM) renormalization schemes. Consequently the three loop renormalization group functions are determined for each of these three schemes in each gauge using properties of the renormalization group equation.

    ↳ hep-thhep-phPRD(2015)·11 citations
31. 31*

    The Veneziano ghost, glost and gauge copies in QCD

    D. Dudal🇧🇪 · M. S. Guimaraes🇧🇷

    In this short note, we come back to the recent proposal put forward by Kharzeev and Levin [PRL 114 (2015) 24, 242001], in which they phenomenologically couple the non-perturbative Veneziano ghost to the perturbative gluon, leading to a modified gluon propagator (the "glost") of the Gribov type, with complex poles. As such, a possible link was made between the QCD topological \theta-vacuum (Veneziano ghost) and color confinement (no physically observable gluons). We discuss some subtleties concerning gauge (BRST) invariance of this proposal, related to the choice of Feynman gauge. We furthermore provide an example in the Landau gauge of a similar phenomenological vertex that also describes the necessary Veneziano ghost but does not affect the Landau gauge gluon propagator.

    ↳ hep-thhep-phPRD(2016)·5 citations
32. 32*

    Chiral transport of neutrinos in supernovae: Neutrino-induced fluid helicity and helical plasma instability

    Naoki Yamamoto🇯🇵

    Chirality of neutrinos modifies the conventional kinetic theory and hydrodynamics, leading to unusual chiral transport related to quantum anomalies in field theory. We argue that these corrections have new phenomenological consequences for hot and dense neutrino gases, especially in core-collapse supernovae. We find that the neutrino density can be converted to the fluid helicity through the chiral vortical effect. This fluid helicity effectively acts as a chiral chemical potential for electrons via the momentum exchange with neutrinos and induces a "helical plasma instability" that generates a strong helical magnetic field. This provides a new mechanism for converting the gravitational energy released by the core collapse to the electromagnetic energy and potentially explains the origin of magnetars. The other possible applications of the neutrino chiral transport theory are also discussed.

    ↳ astro-ph.HEhep-phhep-thnucl-thPRD(2016)·124 citations
33. 33*

    Determination of ${\epsilon }_K$ using lattice QCD inputs

    Jon A. Bailey🇰🇷 · Yong-Chull Jang🇰🇷 · Weonjong Lee🇰🇷 · Sungwoo Park🇰🇷

    We present results for the indirect CP violation parameter ${\epsilon }_K$ determined directly from the standard model using lattice QCD to fix the inputs ${\hat{B}}_K$, ${\xi }_0$, $|V_{us}|$, and $|V_{cb}|$. We use the FLAG and SWME results for ${\hat{B}}_K$. We use the RBC-UKQCD result for ${\xi }_0$ determined using the experimental value of ${\epsilon }^{\prime }/\epsilon$ and the lattice result of $\mathrm{Im}{A}_2$. To set the Wolfenstein parameter $\lambda$, we use $|V_{us}|$, which is determined from $K_{\ell 3}$ and $K_{\mu 2}$ decays combined with lattice evaluations of the $K\to \pi \ell \nu$ vector form factor and $f_K$. To set the Wolfenstein parameter $A$, we use the FNAL/MILC results for $|V_{cb}|$, which are determined from the exclusive decay $\bar{B}\to D^{\ast }\ell \bar{\nu }$ and the axial form factor at zero recoil. We also use the inclusive $|V_{cb}|$ obtained using the heavy quark expansion based on QCD sum rules and the OPE. We compare the results with those for exclusive $|V_{cb}|$. We find that the standard model prediction of ${\epsilon }_K$ with exclusive $|V_{cb}|$ (lattice QCD results) is lower than the experimental value by 3.4$\sigma$. However, we observe no tension in ${\epsilon }_K$ determined from inclusive $|V_{cb}|$.

    ↳ hep-lathep-phPoS(2015)·16 citations
34. 34*

    Cosmological limits on neutrino unknowns versus low redshift priors

    Eleonora Di Valentino🇫🇷 · Elena Giusarma🇮🇹 · Olga Mena🇪🇸 · Alessandro Melchiorri🇮🇹 · Joseph Silk🇫🇷

    Recent Cosmic Microwave Background (CMB) temperature and polarization anisotropy measurements from the Planck mission have significantly improved previous constraints on the neutrino masses as well as the bounds on extended models with massless or massive sterile neutrino states. However, due to parameter degeneracies, additional low redshift priors are mandatory in order to sharpen the CMB neutrino bounds. We explore here the role of different priors on low redshift quantities, such as the Hubble constant, the cluster mass bias, and the reionization optical depth $\tau$. Concerning current priors on the Hubble constant and the cluster mass bias, the bounds on the neutrino parameters may differ appreciably depending on the choices adopted in the analyses. With regard to future improvements in the priors on the reionization optical depth, a value of $\tau =0.05\pm 0.01$, motivated by astrophysical estimates of the reionization redshift, would lead to $\sum m_{\nu }<0.0926$~eV at $90\%$~CL, when combining the full \textit{Planck} measurements, Baryon Acoustic Oscillation and Planck clusters data, thereby opening the window to unravel the neutrino mass hierarchy with existing cosmological probes.

    ↳ astro-ph.COhep-phPRD(2016)·90 citations
35. 35*

    Luminosity of ultrahigh energy cosmic rays and bounds on magnetic luminosity of radio-loud active galactic nuclei

    C. H. Coimbra-Araújo🇧🇷 · R. C. Anjos🇧🇷

    We investigate the production of magnetic flux from rotating black holes in active galactic nuclei (AGNs) and compare it with the upper limit of ultrahigh energy cosmic ray (UHECR) luminosities, calculated from observed integral flux of GeV-TeV gamma rays for nine UHECR AGN sources. We find that, for the expected range of black hole rotations (0.44<a<0.80), the corresponding bounds of theoretical magnetic luminosities from AGNs coincides with the calculated UHECR luminosity. We argue that such result possibly can contribute to constrain AGN magnetic and dynamic properties as phenomenological tools to explain the requisite conditions to proper accelerate the highest energy cosmic rays.

    ↳ astro-ph.HEhep-phhep-thPRD(2015)·5 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.