Fri·Mar 31, 2017Friday·March 31, 2017

1. 01*

   Emerging Internal Symmetries from Effective Spacetimes

   Manfred Lindner🇩🇪 · Sebastian Ohmer🇩🇪

   Can global internal and spacetime symmetries be connected without supersymmetry? To answer this question, we investigate Minkowski spacetimes with d space-like extra dimensions and point out under which general conditions external symmetries induce internal symmetries in the effective 4-dimensional theories. We further discuss in this context how internal degrees of freedom and spacetime symmetries can mix without supersymmetry in agreement with the Coleman-Mandula theorem. We present some specific examples which rely on a direct product structure of spacetime such that orthogonal extra dimensions can have symmetries which mix with global internal symmetries. This mechanism opens up new opportunities to understand global symmetries in particle physics.

   hep-phhep-thPLB(2017)·2 citations
2. 02*

   Composite Higgs models after Run2

   Veronica Sanz🇬🇧 · Jack Setford🇬🇧

   We assess the status of models in which the Higgs is a composite pseudo-Nambu Goldstone boson, in the light of the latest 13 TeV Run 2 Higgs data. Drawing from the extensive Composite Higgs literature, we collect together predictions for the modified couplings of the Higgs, in particular examining the different predictions for ${\kappa }_V$ and ${\kappa }_F$. Despite the variety and increasing complexity of models on the market, we point out that many independent models make identical predictions for these couplings. We then look into further corrections induced by tree-level effects such as mass-mixing and singlet VEVs. We then investigate the compatibility of different models with the data, combining the Run 1 and recent Run 2 LHC data. We obtain a robust limit on the scale $f$ of 600 GeV, with stronger limits for different choices of fermion embeddings. We also discuss how a deficit in a Higgs channel could pinpoint the type of Composite Higgs model responsible for it.

   hep-phAdv.High Energy Phys.(2018)·49 citations
3. 03*

   Indirect searches of Galactic diffuse dark matter in INO-MagICAL detector

   Amina Khatun🇮🇳 · Ranjan Laha🇺🇸 · Sanjib Kumar Agarwalla🇮🇳

   The signatures for the existence of dark matter are revealed only through its gravitational interaction. Theoretical arguments support that the Weakly Interacting Massive Particle (WIMP) can be a class of dark matter and it can annihilate and/or decay to Standard Model particles, among which neutrino is a favorable candidate. We show that the proposed 50 kt Magnetized Iron CALorimeter (MagICAL) detector under the India-based Neutrino Observatory (INO) project can play an important role in the indirect searches of Galactic diffuse dark matter in the neutrino and antineutrino mode separately. We present the sensitivity of 500 kt$\cdot$yr MagICAL detector to set limits on the velocity-averaged self-annihilation cross-section ($⟨\sigma v⟩$) and decay lifetime ($\tau$) of dark matter having mass in the range of 2 GeV $\le m_{\chi }\le$ 90 GeV and 4 GeV $\le m_{\chi }\le$ 180 GeV respectively, assuming no excess over the conventional atmospheric neutrino and antineutrino fluxes at the INO site. Our limits for low mass dark matter constrain the parameter space which has not been explored before. We show that MagICAL will be able to set competitive constraints, $⟨\sigma v⟩\le 1.87\times 10^{-24}$ cm${}^3$ s${}^{-1}$ for $\chi \chi \to \nu \bar{\nu }$ and $\tau \ge 4.8\times 10^{24}$ s for $\chi \to \nu \bar{\nu }$ at 90$\%$ C.L. (1 d.o.f.) for $m_{\chi }$ = 10 GeV assuming the NFW as dark matter density profile.

   hep-phastro-ph.GAastro-ph.HEhep-ex+1JHEP(2017)·12 citations
4. 04*

   Exploring the resonances $X(4140)$ and $X(4274)$ through their decay channels

   S. S. Agaev🇦🇿 · K. Azizi🇹🇷 · H. Sundu🇹🇷

   Investigation of the resonances $X(4140)$ and $X(4274)$, which were recently confirmed by the LHCb Collaboration [1], is carried out by treating them as the color triplet and sextet $[cs][\bar{c}\bar{s}]$ diquark-antidiquark states with the spin-parity $J^P=1^{+}$, respectively. We calculate the masses and meson-current couplings of these tetraquarks in the context of QCD two-point sum rule method by taking into account the quark, gluon and mixed vacuum condensates up to eight dimensions. We also study the vertices $X(4140)J/\psi \varphi$ and $X(4274)J/\psi \varphi$, and evaluate corresponding strong couplings $g_{X(4140)J/\psi \varphi }$ and $g_{X(4274)J/\psi \varphi }$ by means of QCD light-cone sum rule method, and a technique of the soft-meson approximation. In turn, these couplings contain a required information to determine the width of the $X(4140)\to J/\psi \varphi$ and $X(4274)\to J/\psi \varphi$ decay channels. We compare our results for the masses and decay widths of the $X(4140)$ and $X(4274)$ resonances with the LHCb data, and alternative theoretical predictions.

   hep-phhep-exhep-latPRD(2017)·38 citations
5. 05*

   Renormalization of the Abelian-Higgs Model in the R-xi and Unitary gauges and the physicality of its scalar potential

   Nikos Irges🇬🇷 · Fotis Koutroulis🇬🇷

   We perform an old school, one-loop renormalization of the Abelian-Higgs model in the Unitary and $R_{\xi }$ gauges, focused on the scalar potential and the gauge boson mass. Our goal is to demonstrate in this simple context the validity of the Unitary gauge at the quantum level, which could open the way for an until now (mostly) avoided framework for loop computations. We indeed find that the Unitary gauge is consistent and equivalent to the $R_{\xi }$ gauge at the level of $\beta$-functions. Then we compare the renormalized, finite, one-loop Higgs potential in the two gauges and we again find equivalence. This equivalence needs not only a complete cancellation of the gauge fixing parameter $\xi$ from the $R_{\xi }$ gauge potential but also requires its $\xi$-independent part to be equal to the Unitary gauge result. We follow the quantum behaviour of the system by plotting Renormalization Group trajectories and Lines of Constant Physics, with the former the well known curves and with the latter, determined by the finite parts of the counter-terms, particularly well suited for a comparison with non-perturbative studies.

   hep-phNPB(2017)·23 citations
6. 06*

   Study of dark matter physics in non-universal gaugino mass scenario

   Junichiro Kawamura🇯🇵 · Yuji Omura🇯🇵

   We study dark matter physics in the Minimal Supersymmetric Standard Model with non-universal gaugino masses at the unification scale. In this scenario, the specific ratio of wino and gluino masses realizes the electro-weak scale naturally and achieves 125 GeV Higgs boson mass. Then, relatively light higgsino is predicted and the lightest neutral particle, that is dominantly given by the neutral component of higgsino, is a good dark matter candidate. The direct detection of the dark matter is sensitive to not only a higgsino mass but also gaugino masses significantly. The upcoming XENON1T experiment excludes the parameter region where bino or gluino is lighter than about 2.5 TeV if the higgsino and the gaugino mass parameters have same signs. We see that the direct detection of dark matter gives stronger bound than the direct search at the LHC experiment when higgsino sizably contributes to the dark matter abundance

   hep-phastro-ph.HEhep-exJHEP(2017)·15 citations
7. 07*

   Radiative decays ${\chi }_{cJ}\to V\gamma$ within the QCD factorisation framework

   N. Kivel🇩🇪 · M. Vanderhaeghen🇩🇪

   We present a discussion of radiative decays ${\chi }_{cJ}\to \gamma \rho (\omega ,\varphi )$. The decay amplitudes are computed within the QCD factorisation framework. NRQCD has been used in the heavy meson sector as well as a collinear expansion in order to describe the overlap with light mesons in the final state. The colour-singlet contributions to all helicity amplitudes have been computed using the light-cone distribution amplitudes of twist-2 and twist-3. All obtained expressions are well defined at least in the leading-order approximation. The colour-octet contributions have also been studied in the Coulomb limit in order to exhibit their scaling behaviour. In order to understand the relevance of the different contributions we perform numerical estimates using the colour-singlet contributions. For the ${\chi }_{c1}\to \gamma V_{\perp }$ decays, to vector mesons with transverse polarisation, we find that the colour-singlet contribution potentially allows for a reliable description. On the other hand, for the ${\chi }_{c1}\to \gamma V_{\Vert }$ decays, to vector mesons with longitudinal polarisation, our finding indicate that the colour-octet mechanism may be important for a good description. We expect that more accurate measurements of the decay ${\chi }_{c2}\to \gamma V_{\perp ,\Vert }$ can help to better understand the mechanism of radiative decays.

   hep-phPRD(2017)·3 citations
8. 08*

   Properties of Low-Lying Charmonium States in a Phenomenological Approach

   Praveen P D'Souza · Antony Prakash Monteiro · K. B. Vijaya Kumar

   We investigate the spectrum and decay rates of low lying charmonium states within the framework of the non relativistic quark model by employing a Coulomb like potential from the perturbative one gluon exchange and the linear confining potential along with the potential derived from instanton vacuum to account for the hyperfine mass splitting of charmonium states in variational approach. We predict radiative E1, M1, two-photon, leptonic and two-gluon decay rates of low lying charmonium states. An overall agreement is obtained with the experimental masses and decay widths.

   hep-ph5 citations
9. 09*

   Heavy Quark Potential in a static and strong homogeneous magnetic field

   Mujeeb Hasan🇮🇳 · Bhaswar Chatterjee🇮🇳 · Binoy Krishna Patra🇮🇳

   We have investigated the properties of quarkonia in a thermal QCD medium in the background of strong magnetic field. For that purpose, we employ the Schwinger proper-time quark propagator in the lowest Landau level to calculate the one-loop gluon self-energy, which in the sequel gives the the effective gluon propagator. As an artifact of strong magnetic field approximation ($eB>>T^2$ and $eB>>m^2$), the Debye mass for massless flavors is found to depend only on the magnetic field which is the dominant scale in comparison to the scales prevalent in the thermal medium. However, for physical quark masses, it depends on both magnetic field and temperature in a low temperature and high magnetic field but the temperature dependence is very meagre and becomes independent of temperature beyond a certain temperature and magnetic field. With the above mentioned ingredients, the potential between heavy quark ($Q$) and anti-quark ($\bar{Q}$) is obtained in a hot QCD medium in the presence of strong magnetic field by correcting both short and long range components of the potential in real-time formalism. It is found that the long range part of the quarkonium potential is affected much more by magnetic field as compared to the short range part. This observation facilitates us to estimate the magnetic field beyond which the potential will be too weak to bind $Q\bar{Q}$ together. For example, the $J/\psi$ is dissociated at $eB\sim$ 10 $m_{\pi }^2$ and ${\rm Y}$ is dissociated at $eB\sim$ 100 $m_{\pi }^2$ whereas its excited states, ${\psi }^{\prime }$ and ${{\rm Y}}^{\prime }$ are dissociated at smaller magnetic field $eB=m_{\pi }^2$, $13m_{\pi }^2$, respectively.

   hep-phnucl-thEPJC(2017)·67 citations
10. 10*

    Probing the anomalous $\gamma \gamma \gamma Z$ coupling at the LHC with proton tagging

    Cristian Baldenegro🇺🇸 · Sylvain Fichet🇧🇷 · Gero von Gersdorff🇧🇷 · Christophe Royon🇺🇸

    The sensitivities to the anomalous quartic gauge boson coupling $\gamma \gamma \gamma Z$ are estimated via $\gamma Z$ production with intact protons in the forward region at the LHC. Proton tagging proves to be a powerful tool to suppress the background, which allows consideration of the hadronic decays of the $Z$ boson in addition to the leptonic ones. We discuss the discovery potential for an integrated luminosity of $300{\mathrm{fb}}^{-1}$ and $3000{\mathrm{fb}}^{-1}$. The sensitivity we obtain at $300{\mathrm{fb}}^{-1}$ goes beyond the one expected from LHC bounds on the $Z\to \gamma \gamma \gamma$ decay by about three orders of magnitude. The $\gamma Z$ channel provides important discriminatory information with respect to the exclusive $\gamma \gamma$ channel, as many particles beyond the Standard Model (such as a radion or Kaluza Klein gravitons) predict a signal in the latter but not the former.

    hep-phJHEP(2017)·69 citations
11. 11*

    Probing vector-like quark models with Higgs-boson pair production

    Giacomo Cacciapaglia🇫🇷 · Haiying Cai🇫🇷 · Alexandra Carvalho🇮🇹 · Aldo Deandrea🇫🇷 · Thomas Flacke🇰🇷 · Benjamin Fuks🇫🇷 · Devdatta Majumder🇺🇸 · Hua-Sheng Shao🇫🇷

    We investigate Higgs-boson pair production at the LHC when the final state system arises from decays of vector-like quarks coupling to the Higgs boson and the Standard Model quarks. Our phenomenological study includes next-to-leading-order QCD corrections, which are important to guarantee accurate predictions, and focuses on a detailed analysis of a di-Higgs signal in the four $b$-jet channel. Whereas existing Run II CMS and ATLAS analyses are not specifically designed for probing non-resonant, vector-like-quark induced, di-Higgs production, we show that they nevertheless offer some potential for these modes. We then investigate the possibility of distinguishing between the various di-Higgs production mechanisms by exploiting the kinematic properties of the signal.

    hep-phJHEP(2017)·28 citations
12. 12*

    Measurement of the Higgs Boson Couplings and CP Structure Using Tau Leptons at the LHC

    Daniele Zanzi🇦🇺

    Results on the $H\to \tau \tau$ measurements performed by the ATLAS and CMS collaborations with the pp collision data collected at the LHC at $\sqrt{s}=$7 and 8 TeV are presented. These include a test of CP invariance in the VBF Higgs boson production. Experimental challenges for the test of the CP invariance in the $H\to \tau \tau$ decays are also reviewed.

    ↳ hep-exhep-phNucl.Part.Phys.Proc.(2017)·3 citations
13. 13*

    Solar Atmospheric Neutrinos: A New Neutrino Floor for Dark Matter Searches

    Kenny C. Y. Ng🇮🇱 · John F. Beacom🇺🇸 · Annika H. G. Peter🇺🇸 · Carsten Rott🇰🇷

    As is well known, dark matter direct detection experiments will ultimately be limited by a "neutrino floor," due to the scattering of nuclei by MeV neutrinos from, e.g., nuclear fusion in the Sun. Here we point out the existence of a new "neutrino floor" that will similarly limit indirect detection with the Sun, due to high-energy neutrinos from cosmic-ray interactions with the solar atmosphere. We have two key findings. First, solar atmospheric neutrinos $\lesssim 1$ TeV cause a sensitivity floor for standard WIMP scenarios, for which higher-energy neutrinos are absorbed in the Sun. This floor will be reached once the present sensitivity is improved by just one order of magnitude. Second, for neutrinos $\gtrsim 1$ TeV, which can be isolated by muon energy loss rate, solar atmospheric neutrinos should soon be detectable in IceCube. Discovery will help probe the complicated effects of solar magnetic fields on cosmic rays. These events will be backgrounds to WIMP scenarios with long-lived mediators, for which higher-energy neutrinos can escape from the Sun.

    ↳ astro-ph.HEhep-exhep-phPRD(2017)·99 citations
14. 14*

    Second-order Cosmological Perturbations Engendered by Point-like Masses

    Ruslan Brilenkov🇦🇹 · Maxim Eingorn🇺🇸

    In the $\Lambda$CDM framework, presenting nonrelativistic matter inhomogeneities as discrete massive particles, we develop the second-order cosmological perturbation theory. Our approach relies on the weak gravitational field limit. The derived equations for the second-order scalar, vector and tensor metric corrections are suitable at arbitrary distances including regions with nonlinear contrasts of the matter density. We thoroughly verify fulfilment of all Einstein equations as well as self-consistency of order assignments. In addition, we achieve logical positive results in the Minkowski background limit. Feasible investigations of the cosmological backreaction manifestations by means of relativistic simulations are also outlined.

    ↳ gr-qcastro-ph.COhep-phhep-thApJ(2017)·23 citations
15. 15*

    Small parameters in infrared quantum chromodynamics

    Marcela Peláez🇺🇾 · Urko Reinosa🇫🇷 · Julien Serreau🇫🇷 · Matthieu Tissier🇫🇷 · Nicolás Wschebor🇺🇾

    We study the long-distance properties of quantum chromodynamics in an expansion in powers of the three-gluon, four-gluon, and ghost-gluon couplings, but without expanding in the quark-gluon coupling. This is motivated by two observations. First, the gauge sector is well-described by perturbation theory in the context of a phenomenological model with a massive gluon. Second, the quark-gluon coupling is significantly larger than those in the gauge sector at large distances. In order to resum the contributions of the remaining infinite set of QED-like diagrams, we further expand the theory in $1/N_c$, where $N_c$ is the number of colors. At leading order, this double expansion leads to the well-known rainbow approximation for the quark propagator. We take advantage of the systematic expansion to get a renormalization-group improvement of the rainbow resummation. A simple numerical solution of the resulting coupled set of equations reproduces the phenomenology of the spontaneous chiral symmetry breaking: for sufficiently large quark-gluon coupling constant, the constituent quark mass saturates when its valence mass approaches zero. We find very good agreement with lattice data for the scalar part of the propagator and explain why the vectorial part is poorly reproduced.

    ↳ hep-thhep-lathep-phPRD(2017)·53 citations
16. 16*

    Resonant parameters of the $Y(4220)$

    X. Y. Gao🇨🇳 · C. P. Shen🇨🇳 · C. Z. Yuan🇨🇳

    The vector charmoniumlike state $Y(4220)$ was reported recently in the cross sections of $e^{+}{e}^{-}\to \omega {\chi }_{c0}$, ${\pi }^{+}{\pi }^{-}{h}_c$, ${\pi }^{+}{\pi }^{-}J/\psi$, and $D^0{D}^{\ast -}{\pi }^{+}+c.c.$ measured by the BESIII experiment. A combined fit is performed to the cross sections of these four final states to extract the resonant parameters of the $Y(4220)$. We determine a mass $M=(4219.6\pm 3.3\pm 5.1)$~MeV/$c^2$ and a total width $\Gamma =(56.0\pm 3.6\pm 6.9)$~MeV for the $Y(4220)$, where the first uncertainties are statistical and the second ones systematic. Assuming the $Y(4220)$ decays dominantly to the above four modes and their isospin symmetric modes, we also estimate its leptonic decay width and decay branching fractions. These information is essential for the understanding of the nature of this state.

    ↳ hep-exhep-phPRD(2017)·37 citations
17. 17*

    Wilson lines and UV sensitivity in magnetic compactifications

    D. M. Ghilencea🇷🇴 · Hyun Min Lee🇰🇷

    We investigate the ultraviolet (UV) behaviour of 6D N=1 supersymmetric effective (Abelian) gauge theories compactified on a two-torus ($T_2$) with magnetic flux. To this purpose we compute offshell the one-loop correction to the Wilson line state self-energy. The offshell calculation is actually necessary to capture the usual effective field theory expansion in powers of $(\partial /\Lambda )$. Particular care is paid to the regularization of the (divergent) momentum integrals, which is relevant for identifying the corresponding counterterm(s). We find a counterterm which is a new higher dimensional effective operator of dimension d=6, that is enhanced for a larger compactification area (where the effective theory applies) and is consistent with the symmetries of the theory. Its consequences are briefly discussed and comparison is made with orbifold compactifications without flux.

    ↳ hep-thhep-phJHEP(2017)·25 citations
18. 18*

    ATLAS results on diffraction and exclusive production

    Marek Tasevsky🇨🇿

    Various aspects of forward physics have been studied by the ATLAS collaboration using data from Run I at the LHC. In this text, main results of three published analyses are summarized, based on data from proton-proton collisions at $\sqrt{s}=7$ or 8 TeV collected between 2010 and 2012. One analysis deals with diffractive signature with at least two jets in the final state, the other two study exclusive production of a pair of leptons or W bosons.

    ↳ hep-exhep-ph2 citations
19. 19*

    Tensor to scalar ratio from single field magnetogenesis

    Massimo Giovannini🇨🇭

    The tensor to scalar ratio is affected by the evolution of the large-scale gauge fields potentially amplified during an inflationary stage of expansion. After deriving the exact evolution equations for the scalar and tensor modes of the geometry in the presence of dynamical gauge fields, it is shown that the tensor to scalar ratio is bounded from below by the dominance of the adiabatic contribution and it cannot be smaller than one thousands whenever the magnetogenesis is driven by a single inflaton field.

    ↳ astro-ph.COgr-qchep-phhep-thPLB(2017)·3 citations
20. 20*

    Shedding light on the small-scale crisis with CMB spectral distortions

    Tomohiro Nakama🇺🇸 · Jens Chluba🇬🇧 · Marc Kamionkowski🇺🇸

    The small-scale crisis, discrepancies between observations and N-body simulations, may imply suppressed matter fluctuations on subgalactic distance scales. Such a suppression could be caused by some early-universe mechanism (e.g., broken scale invariance during inflation), leading to a modification of the primordial power spectrum at the onset of the radiation-domination era. Alternatively, it may be due to nontrivial dark-matter properties (e.g., new dark-matter interactions or warm dark matter) that affect the matter power spectrum at late times, during radiation domination, after the perturbations re-enter the horizon. We show that early- and late-time suppression mechanisms can be distinguished by measurement of the $\mu$ distortion to the frequency spectrum of the cosmic microwave background. This is because the $\mu$ distortion is suppressed, if the power suppression is primordial, relative to the value expected from the dissipation of standard nearly scale-invariant fluctuations. We emphasize that the standard prediction of the $\mu$ distortion remains unchanged in late-time scenarios even if the dark-matter effects occur before or during the era (redshifts $5\times 10^4\lesssim z\lesssim 2\times 10^6$) at which $\mu$ distortions are generated.

    ↳ astro-ph.COgr-qchep-phPRD(2017)·62 citations
21. 21*

    Mass generation by a Lorentz-invariant gas of spacetime defects

    F.R. Klinkhamer🇩🇪 · J.M. Queiruga🇩🇪

    We present a simple model of defects embedded in flat spacetime, where the model is designed to maintain Lorentz invariance over large length scales. Even without remnant Lorentz violation, there are still effects from these spacetime defects on the propagation of physical fields, notably mass generation for scalars and Dirac fermions.

    ↳ hep-thhep-phPRD(2017)·5 citations
22. 22*

    Probing Planckian corrections at the horizon scale with LISA binaries

    Andrea Maselli🇩🇪 · Paolo Pani🇮🇹 · Vitor Cardoso🇵🇹 · Tiziano Abdelsalhin🇮🇹 · Leonardo Gualtieri🇮🇹 · Valeria Ferrari🇮🇹

    Several quantum-gravity models of compact objects predict microscopic or even Planckian corrections at the horizon scale. We explore the possibility of measuring two model-independent, smoking-gun effects of these corrections in the gravitational waveform of a compact binary, namely the absence of tidal heating and the presence of tidal deformability. For events detectable by the future space-based interferometer LISA, we show that the effect of tidal heating dominates and allows one to constrain putative corrections down to the Planck scale. The measurement of the tidal Love numbers with LISA is more challenging but, in optimistic scenarios, it allows to constrain the compactness of a supermassive exotic compact object down to the Planck scale. Our analysis suggests that highly-spinning, supermassive binaries at 1-20 Gpc provide unparalleled tests of quantum-gravity effects at the horizon scale.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRL(2018)·174 citations
23. 23*

    Probing Noncommutativities of Phase Space by Using Persistent Charged Current and Its Asymmetry

    Kai Ma · Ya-Jie Ren · Ya-Hui Wang

    We study the physical properties of the persistent charged current in a metal ring on a noncommutative phase space, and temperature dependence of the noncommutative corrections are also analyzed. We find that the coordinate noncommutativity only affects the total magnitude of the current, and it is difficult to observe it. In contrast, the momentum noncommutativity can violate symmetry property of the current, and this violation of symmetry holds at a finite temperature. Based on this violation effect, we introduce an asymmetry observable to measure the momentum noncommutativity.

    ↳ hep-thgr-qchep-phquant-phPRD(2018)·18 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.