Fri·Feb 26, 2016Friday·February 26, 2016

1. 01*

   New physics in the kinematic distributions of $\bar{B}\to D^{(\ast )}{\tau }^{-}(\to {\ell }^{-}{\bar{\nu }}_{\ell }{\nu }_{\tau }){\bar{\nu }}_{\tau }$

   Rodrigo Alonso🇺🇸 · Andrew Kobach🇺🇸 · Jorge Martin Camalich🇩🇪

   We investigate the experimentally-accessible kinematic distributions of the $\bar{B}\to D^{(\ast )}{\tau }^{-}(\to {\ell }^{-}{\bar{\nu }}_{\ell }{\nu }_{\tau }){\bar{\nu }}_{\tau }$ decays. Specifically, we study the decay rates as functions of the $B\to D^{(\ast )}$ transferred squared momentum, the energy of the final charged lepton and the angle of its 3-momentum relative to the 3-momentum of the recoiling $D^{(\ast )}$. The angular distribution allows to introduce new observables, like a forward-backward asymmetry, which are complementary to the total rates. We present analytic formulas for the observable 3-fold 5-body differential decay rates, study the predictions in the Standard Model and investigate the effects in different new-physics scenarios that we characterize using an effective field theory framework.

   hep-phhep-exPRD(2016)·93 citations
2. 02*

   The NMSSM lives: with the 750 GeV diphoton excess

   F. Domingo🇪🇸 · S. Heinemeyer🇪🇸 · J.S. Kim🇪🇸 · K. Rolbiecki🇪🇸

   We propose an NMSSM scenario that can explain the excess in the diphoton spectrum at 750 GeV recently observed by ATLAS and CMS. We show that in a certain limit with a very light pseudoscalar one can reproduce the experimental results without invoking exotic matter. The 750 GeV excess is produced by two resonant heavy Higgs bosons with masses ~750 GeV, that subsequently decay to two light pseudoscalars. Each of these decays to collimated photon pairs that appear as a single photon in the electromagnetic calorimeter. A mass gap between heavy Higgses mimics a large width of the 750 GeV peak. The production mechanism, containing a strong component via initial b quarks, ameliorates a possible tension with 8 TeV data compared to other production modes. We also discuss other constraints, in particular from low energy experiments. Finally, we discuss possible methods that could distinguish our proposal from other physics models describing the diphoton excess in the Run-II of the LHC.

   hep-phEPJC(2016)·41 citations
3. 03*

   The Higgs mass and natural supersymmetric spectrum from the landscape

   Howard Baer🇺🇸 · Vernon Barger🇺🇸 · Michael Savoy🇺🇸 · Hasan Serce🇺🇸

   In supersymmetric models where the superpotential mu term is generated with mu<< m_{soft} (e.g. from radiative Peccei-Quinn symmetry breaking or compactified string models with sequestration and stabilized moduli), and where the string landscape 1. favors soft supersymmetry (SUSY) breaking terms as large as possible and 2. where the anthropic condition that electroweak symmetry is properly broken with a weak scale m_{W,Z,h}~100 GeV ({\it i.e.} not too weak of weak interactions), then these combined landscape/anthropic requirements act as an attractor pulling the soft SUSY breaking terms towards values required by models with radiatively-driven naturalness: near the line of criticality where electroweak symmetry is barely broken and the Higgs mass is ~125 GeV. The pull on the soft terms serves to ameliorate the SUSY flavor and CP problems. The resulting sparticle mass spectrum may barely be accessible at high-luminosity LHC while the required light higgsinos should be visible at a linear e^+e^- collider with \sqrt{s}>2m(higgsino).

   hep-phPLB(2016)·40 citations
4. 04*

   SU(2) x SU(2) x U(1) Interpretation on the 750 GeV Diphoton Excess

   Jing Ren🇨🇦 · Jiang-Hao Yu🇺🇸

   We propose that the SU(2) x SU(2) x U(1) (aka G221) models could provide us a 750 GeV scalar resonance that may account for the diphoton excess observed at the LHC while satisfying present collider constraints. The neutral component of the $SU(2{)}_R$ scalar multiplet can be identified as the 750 GeV scalar. In the lepto-phobic and fermio-phobic G221 models the new charged gauge boson W' could be light, and we find that the diphoton decay width could be dominated by the loop contribution from the $W^{\prime }$. To initiate gluon fusion production, it is necessary to extend the G221 symmetry to the Pati-Salam and SO(10) symmetry. We investigate the possibilities that the light colored scalars or vectorlike fermions survive in the SO(10) theory and provide large gluon fusion rate for the diphoton signature. It is possible to test the G221 interpretation by direct searches of W' using the multi-gauge boson production channel at the Run 2 LHC.

   hep-phhep-ex20 citations
5. 05*

   Boosting low-mass hadronic resonances

   Chase Shimmin🇺🇸 · Daniel Whiteson🇺🇸

   Searches for new hadronic resonances typically focus on high-mass spectra, due to overwhelming QCD backgrounds and detector trigger rates. We present a study of searches for relatively low-mass hadronic resonances at the LHC in the case that the resonance is boosted by recoiling against a well-measured high-$p_{\text{T}}$ probe such as a muon, photon or jet. The hadronic decay of the resonance is then reconstructed either as a single large-radius jet or as a resolved pair of standard narrow-radius jets, balanced in transverse momentum to the probe. We show that the existing 2015 LHC dataset of $pp$ collisions with $\int \mathcal{L}dt=4{\mathrm{fb}}^{-1}$ should already have powerful sensitivity to a generic $Z^{\prime }$ model which couples only to quarks, for $Z^{\prime }$ masses ranging from 20-500 GeV/c${}^2$.

   hep-phhep-exPRD(2016)·20 citations
6. 06*

   DSiD: a Delphes Detector for ILC Physics Studies

   C.T. Potter🇺🇸

   We describe DSiD, a fast simulation Delphes detector for the International Linear Collider (ILC) based on the full simulation performance of the SiD detector. SiD is one of two detectors described in the ILC Technical Design Report (TDR). The tracking efficiency, tracking momentum resolution, electromagnetic and hadronic calorimeter energy resolution, particle identification and flavor tagging efficiencies are taken from the Detailed Baseline Design (DBD) study as described in ILC TDR Volume 4: Detectors. In a cross-check study with $4\times 10^6$ $e^{+}{e}^{-}\to b\bar{b}$ events generated at $\sqrt{s}=500$ GeV and simulated by Delphes with the DSiD detector card, these performance characteristics are measured and found to be commensurate with the DBD results. For a new physics use case example, we describe a study of Next-to-Minimal Supersymmetric $e^{+}{e}^{-}\to 2{\chi }_3\to 2{\chi }_{1}2h_1$ with $h_1\to 2a_1$ or $h_1\to b\bar{b}$ at the $\sqrt{s}=500$ GeV ILC. The card is available on HepForge.

   hep-phhep-ex33 citations
7. 07*

   Elements of QED-NRQED Effective Field Theory: I. NLO scattering at leading power

   Steven P. Dye🇺🇸 · Matthew Gonderinger🇺🇸 · Gil Paz🇺🇸

   The proton radius puzzle, i.e. the large discrepancy in the extraction of the proton charge radius between regular and muonic hydrogen, challenges our understanding of the structure of the proton. It can also be an indication of a new force that couples to muons, but not to electrons. An effective field theory analysis using Non Relativistic Quantum Electrodynamics (NRQED) indicates that the muonic hydrogen result can be interpreted as a large, compared to some model estimates, muon-proton spin-independent contact interaction. The muonic hydrogen result can be tested by a muon-proton scattering experiment, MUSE, that is planned at the Paul Scherrer Institute in Switzerland. The typical momenta of the muons in this experiment are of the order of the muon mass. In this energy regime the muons are relativistic but the protons are still non-relativistic. The interaction between the muons and protons can be described by a hybrid QED-NRQED effective field theory. We present some elements of this effective field theory. In particular we consider $\mathcal{O}(Z\alpha )$ scattering up to power $m^2/M^2$, where $m$ ($M$) is the muon (proton) mass and $Z=1$ for a proton, and $\mathcal{O}(Z^2{\alpha }^2)$ scattering at leading power. We show how the former reproduces Rosenbluth scattering up to power $m^2/M^2$ and the latter the relativistic scattering off a static potential. Proton structure corrections at $\mathcal{O}(Z^2{\alpha }^2)$ will be considered in a subsequent paper.

   hep-phnucl-thPRD(2016)·16 citations
8. 08*

   Coherent Pion Production in Neutrino Nucleus Scattering

   Kapil Saraswat🇮🇳 · Prashant Shukla🇮🇳 · Vineet Kumar🇮🇳 · Venktesh Singh🇮🇳

   In this article, we study the coherent pion production in neutrino-nucleus interaction in the resonance region using the formalism based on partially conserved axial current (PCAC) theorem which relates the neutrino-nucleus cross section to the pion-nucleus elastic cross section. The pion nucleus elastic cross section is calculated using the Glauber model in terms of pion-nucleon cross sections obtained by parameterizing the experimental data. We calculate the differential and integrated cross sections for charged current coherent pion production in neutrino carbon scattering. The results of integrated cross section calculations are compared with the measured data. Predictions for the differential and integrated cross sections for coherent pion productions in neutrino iron scattering using above formalism are also made.

   hep-phnucl-thPRC(2016)·10 citations
9. 09*

   Radially excited axial mesons and the enigmatic $Z_c$ and $Z_b$ in a coupled-channel model

   Susana Coito🇨🇳

   The enigmatic charged states $Z_c(3900)$, $Z_c(4020)$, $Z_c(4050)$, $Z_b(10610)$, and $Z_b(10650)$ are studied within a coupled-channel Schrödinger model, where radially excited quark-antiquark pairs, with the same angular momenta and isospin as the $a_1(1260)$ and $b_1(1235)$, are strongly coupled to their Okubo-Zweig-Iizuka - allowed decay channels $D{\bar{D}}^{\ast }+\bar{D}{D}^{\ast }$ and $D^{\ast }{\bar{D}}^{\ast }$, or $B{\bar{B}}^{\ast }+\bar{B}{B}^{\ast }$ and $B^{\ast }{\bar{B}}^{\ast }$, in $S$ and $D$-wave. Poles, matching the experimental mass and width of all the above states, are found by varying only two free parameters. From the wave-function analysis of each resonance, the probability of each of the components contributing to the coupled system is estimated, and predictions can be made for the relative decay fractions among the coupled open-charm or open-bottom decay channels.

   hep-phPRD(2016)·13 citations
10. 10*

    A CP-violating phase in a two Higgs triplet scenario : some phenomenological implications

    Avinanda Chaudhuri🇮🇳 · Biswarup Mukhopadhyaya🇮🇳

    We consider a scenario where, along with the usual Higgs doublet, two scalar triplets are present. The extension of the triplet sector is required for the Type~II mechanism for the generation of neutrino masses, if this mechanism has to generate a neutrino mass matrix with two-zero texture. One CP-violating phase has been retained in the scalar potential of the model, and all parameters have been chosen consistently with the observed neutrino mass and mixing patterns. We find that a large phase ($\gtrsim 60^{\circ }$) splits the two doubly-charged scalar mass eigenstates wider apart, so that the decay $H_1^{++}\to H_2^{++}h$ is dominant (with h being the $125$ GeV scalar). We identify a set of benchmark points where this decay dominates. This is complementary to the situation, reported in our earlier work, where the heavier doubly-charged scalar decays as $H_1^{++}\to H_2^{+}{W}^{+}$. We point out the rather spectacular signal, ensuing from $H_1^{++}\to H_2^{++}h$, in the form of Higgs plus same-sign dilepton peak, which can be observed at the Large Hadron Collider.

    hep-phPRD(2016)·8 citations
11. 11*

    Decay $B_s\to \varphi {\ell }^{+}{\ell }^{-}$ in covariant quark model

    Stanislav Dubnička🇸🇰 · Anna Z. Dubničková🇸🇰 · Aidos Issadykov🇷🇺 · Mikhail A. Ivanov🇷🇺 · Andrej Liptaj🇸🇰 · Sayabek K. Sakhiyev🇰🇿

    Our article is devoted to the study of the rare $B_s\to \varphi {\ell }^{+}{\ell }^{-}$ decay where $\ell =\mu ,\tau$. We compute the relevant form factors in the framework of the covariant quark model with infrared confinement in the full kinematical momentum transfer region. The calculated form factors are used to evaluate branching fractions and polarization observables in the cascade decay $B\to \varphi (\to K^{+}{K}^{-}){\ell }^{+}{\ell }^{-}$. We compare the obtained results with available experimental data and the results from other theoretical approaches.

    hep-phnucl-thPRD(2016)·27 citations
12. 12*

    Diphoton resonances in a U(1)_{B-L} extension of the minimal supesymmetric standard model

    G. Lazarides🇬🇷 · Q. Shafi🇺🇸

    Inspired by the 750 GeV diphoton state recently reported by ATLAS and CMS, we propose a U(1)_{B-L} extension of the MSSM which predicts the existence of four spin zero resonance states that are degenerate in mass in the supersymmetric limit. Vector-like fields, a gauge singlet field, as well as the MSSM Higgsinos are prevented from acquiring arbitrary large masses by a U(1) R-symmetry. Indeed, these masses can be considerably lighter than the Z' gauge boson mass. Depending on kinematics the resonance states could decay into right handed neutrinos and sneutrinos, and/or MSSM Higgs fields and Higgsinos with total decay widths in the multi-GeV range.

    hep-phPRD(2016)·21 citations
13. 13*

    750 GeV diphoton resonance in a visible heavy QCD axion model

    Cheng-Wei Chiang🇹🇼 · Hajime Fukuda🇯🇵 · Masahiro Ibe🇯🇵 · Tsutomu T. Yanagida🇯🇵

    In this paper, we revisit a visible heavy QCD axion model in light of the recent reports on the $750$ GeV diphoton resonance by the ATLAS and CMS experiments. In this model, the axion is made heavy with the help of the mirror copied sector of the Standard Model while the successful Peccei-Quinn mechanism is kept intact. We identify the $750$ GeV resonance as the scalar boson associated with spontaneous breaking of the Peccei-Quinn symmetry which mainly decays into a pair of the axions. We find that the mixings between the axion and $\eta$ and ${\eta }^{\prime }$ play important roles in its decays and the resultant branching ratio into two photons. The axion decay length can be suitable for explaining the diphoton excess by the di-axion production when its decay constant $f_a\simeq 1$ TeV. We also find that our model allows multiple sets of the extra fermions without causing the domain wall problem, which is advantageous to explain the diphoton signal.

    hep-phhep-exPRD(2016)·65 citations
14. 14*

    Average transverse momenta of baryon production at p-p collider experiments and their crucial implications for the high energy hadroproduction physics

    Olga I. Piskounova🇷🇺

    The phenomenological approach in the framework of Quark-Gluon String Model (QGSM) has been applied to the description of transverse momentum spectra for the baryon production at colliders. The analysis of data on hyperon transverse momentum distributions,dN/dp_t, demonstrates a difference in the dynamics of multiparticle production in proton-proton vs. antiproton-proton collisions in the region of low p_t . The most important contribution in antip-p reaction goes from fragmentation of antidiquark-diquark side of pomeron diagram. The complete study of the energy dependence of average transverse momenta for the energies from sqrt(s)= 0.2 to 7. TeV shows the slight growing of <p_t> with energy. No dramatic changes were seen on the range from Tevatron to LHC, which may be responsible for "knee" in the cosmic ray proton spectra. The average transverse momentum analysis through the different mass of hadrons reveals some regularity in the mass gaps between the hadron generations. This observation suggests that more hadrons with the following masses 13.7, 37.3, 101.5, 276, 750 ... GeV are expected by geometrical progression with the mass factor of order $\delta lnM$=1 . These states may possess new quantum numbers beyond the Standard Model. The possibility of QGSM to construct the spectra of baryons in the whole range of x_F gives obvious advantages in the description of production asymmetries: the baryon-over-antibaryon access in the central region of proton-proton collisions, the baryon-to-meson abnormal ratios in nucleus-nucleus reactions, the growing ratios of secondary particles in cosmic ray spectra as well as the recently observed negative asymmetry for charmed baryon/antibaryon spectra at the far rapidity point Y=2 in LHCb experiment. This study, based on the routine analysis of collider data, has many crucial implications for the entire field of hadroproduction physics.

    hep-phPublished in PoS ICHEP2016 (2017) 711·2 citations
15. 15*

    What if the Masses of the First Two Quark Families are not Generated by the Standard Higgs?

    F. J. Botella🇪🇸 · G. C. Branco🇵🇹 · M. N. Rebelo🇵🇹 · J. I. Silva-Marcos🇵🇹

    We point out that, in the context of the SM, $|V_{13}^2|+|V_{23}^2|$ is expected to be large, of order one. The fact that $|V_{13}^2|+|V_{23}^2|\approx 1.6\times 10^{-3}$ motivates the introduction of a symmetry S which leads to $V_{CKM}=1\mathrm{I}$, with only the third generation of quarks acquiring mass. We consider two scenarios for generating the mass of the first two quark generations and full quark mixing. One consists of the introduction of a second Higgs doublet which is neutral under S. The second scenario consists of assuming New Physics at a high energy scale , contributing to the masses of light quark generations, in an effective field theory approach. This last scenario leads to couplings of the Higgs particle to $s\overline{s}$ and $c\overline{c}$ which are significantly enhanced with respect to those of the SM. In both schemes, one has scalar-mediated flavour- changing neutral currents which are naturally suppressed. Flavour violating top decays are predicted in the second scenario at the level $\text{mbox}Br(t\to hc)\ge 5\times 10^{-5}$.

    hep-phPRD(2016)·67 citations
16. 16*

    Challenges to Self-Acceleration in Modified Gravity from Gravitational Waves and Large-Scale Structure

    Lucas Lombriser🇬🇧 · Nelson A. Lima🇬🇧

    With the advent of gravitational-wave astronomy marked by the aLIGO GW150914 and GW151226 observations, a measurement of the cosmological speed of gravity will likely soon be realized. We show that a confirmation of equality to the speed of light as indicated by indirect Galactic observations will have important consequences for a very large class of alternative explanations of the late-time accelerated expansion of our Universe. It will break the dark degeneracy of self-accelerated Horndeski scalar-tensor theories in the large-scale structure that currently limits a rigorous discrimination between acceleration from modified gravity and from a cosmological constant or dark energy. Signatures of a self-acceleration must then manifest in the linear, unscreened cosmological structure. We describe the minimal modification required for self-acceleration with standard gravitational-wave speed and show that its maximum likelihood yields a 3-sigma poorer fit to cosmological observations compared to a cosmological constant. Hence, equality between the speeds challenges the concept of cosmic acceleration from a genuine scalar-tensor modification of gravity.

    ↳ astro-ph.COgr-qchep-phhep-thPLB(2017)·288 citations
17. 17*

    Why Firewalls Need Not Exist

    Yasunori Nomura🇺🇸 · Nico Salzetta🇺🇸

    The firewall paradox for black holes is often viewed as indicating a conflict between unitarity and the equivalence principle. We elucidate how the paradox manifests as a limitation of semiclassical theory, rather than presents a conflict between fundamental principles. Two principal features of the fundamental and semiclassical theories address two versions of the paradox: the entanglement and typicality arguments. First, the physical Hilbert space describing excitations on a fixed black hole background in the semiclassical theory is exponentially smaller than the number of physical states in the fundamental theory of quantum gravity. Second, in addition to the Hilbert space for physical excitations, the semiclassical theory possesses an unphysically large Fock space built by creation and annihilation operators on the fixed black hole background. Understanding these features not only eliminates the necessity of firewalls but also leads to a new picture of Hawking emission contrasting pair creation at the horizon.

    ↳ hep-thgr-qchep-phPLB(2016)·16 citations
18. 18*

    Remarks on the pion-nucleon sigma-term

    Martin Hoferichter🇺🇸 · Jacobo Ruiz de Elvira🇩🇪 · Bastian Kubis🇩🇪 · Ulf-G. Meißner🇩🇪

    The pion-nucleon $\sigma$-term can be stringently constrained by the combination of analyticity, unitarity, and crossing symmetry with phenomenological information on the pion-nucleon scattering lengths. Recently, lattice calculations at the physical point have been reported that find lower values by about $3\sigma$ with respect to the phenomenological determination. We point out that a lattice measurement of the pion-nucleon scattering lengths could help resolve the situation by testing the values extracted from spectroscopy measurements in pionic atoms.

    ↳ hep-lathep-phnucl-thPLB(2016)·77 citations
19. 19*

    From Bethe-Salpeter Wave Functions to Generalised Parton Distributions

    C. Mezrag🇺🇸 · H. Moutarde🇫🇷 · J. Rodriguez-Quintero🇪🇸

    We review recent works on the modelling of Generalised Parton Distributions within the Dyson-Schwinger formalism. We highlight how covariant computations, using the impulse approximation, allows one to fulfil most of the theoretical constraints of the GPDs. Specific attention is brought to chiral properties and especially the so-called soft pion theorem, and its link with the Axial-Vector Ward-Takahashi identity. The limitation of the impulse approximation are also explained. Beyond impulse approximation computations are reviewed in the forward case. Finally, we stress the advantages of the overlap of lightcone wave functions, and possible ways to construct covariant GPD models within this framework, in a two-body approximation.

    ↳ nucl-thhep-phFew Body Syst.(2016)·68 citations
20. 20*

    ${\Lambda }_c-N$ interaction from lattice QCD

    Takaya Miyamoto · for HAL QCD Collaboration

    We investigate the s-wave ${\Lambda }_c-N$ interaction for spin singlet systems(${}^1{S}_0$) using the HAL QCD method. In our lattice QCD simulations, we employ gauge configurations generated by the PACS-CS Collaboration at $a=0.0907(13)$ fm on a $32^3\times 64$ lattice ($La=2.902(42)$ fm). We employ two ensembles, one at $m_{\pi }=700(1)$ MeV and the other at $m_{\pi }=570(1)$ MeV to study the quark mass dependence of the ${\Lambda }_c-N$ interactions. We calculate a ${}^1{S}_0$ central potential not only for the ${\Lambda }_c-N$ system but also for $\Lambda -N$ system to understand the role of heavy charm quarks in ${\Lambda }_c-N$ system. We find repulsion at short distance and attraction at mid-range for both the ${\Lambda }_c-N$ and the $\Lambda -N$ potentials. The short range repulsion of the ${\Lambda }_c-N$ potential is smaller than that of the $\Lambda -N$ potential, and the attraction of the ${\Lambda }_c-N$ potential is small compared with the $\Lambda -N$ potential. The phase shift and scattering length calculated with these potentials show that there exist no bound state for both the ${\Lambda }_c-N$ and $\Lambda -N$ systems for $m_{\pi }>570$ MeV.

    ↳ hep-lathep-phnucl-thPoS(2016)·15 citations
21. 21*

    Coupling the Inflationary Sector to Matter

    Renata Kallosh🇺🇸 · Andrei Linde🇺🇸 · Timm Wrase🇦🇹

    We describe the coupling of matter fields to an inflationary sector of supergravity, the inflaton $\Phi$ and a stabilizer $S$, in models where the Kahler potential has a flat inflaton direction. Such models include, in particular, advanced versions of the hyperbolic $\alpha$-attractor models with a flat inflaton direction Kahler potential, providing a good fit to the observational data. If the superpotential is at least quadratic in the matter fields $U^i$, with restricted couplings to the inflaton sector, we prove that under certain conditions: i) The presence of the matter fields does not affect a successful inflationary evolution. ii) There are no tachyons in the matter sector during and after inflation. iii) The matter masses squared are higher than $3H^2$ during inflation. The simplest class of theories satisfying all required conditions is provided by models with a flat direction Kahler potential, and with the inflaton $\Phi$ and a stabilizer $S$ belonging to a hidden sector, so that matter fields have no direct coupling to the inflationary sector in the Kahler potential and in the superpotential.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2016)·19 citations
22. 22*

    Large-scale shell-model analysis of the neutrinoless $\beta \beta$ decay of ${}^{48}$Ca

    Y. Iwata🇯🇵 · N. Shimizu🇯🇵 · T. Otsuka🇯🇵 · Y. Utsuno🇯🇵 · J. Menendez🇯🇵 · M. Honma🇯🇵 · T. Abe🇯🇵

    We present the nuclear matrix element for the neutrinoless double-beta decay of ${}^{48}$Ca based on large-scale shell-model calculations including two harmonic oscillator shells ($sd$ and $pf$ shells). The excitation spectra of ${}^{48}$Ca and ${}^{48}$Ti, and the two-neutrino double-beta decay of ${}^{48}$Ca are reproduced in good agreement to experiment. We find that the neutrinoless double-beta decay nuclear matrix element is enhanced by about 30\% compared to $pf$-shell calculations. This reduces the decay lifetime by almost a factor of two. The matrix-element increase is mostly due to pairing correlations associated with cross-shell $sd$-$pf$ excitations. We also investigate possible implications for heavier neutrinoless double-beta decay candidates.

    ↳ nucl-thhep-exhep-phnucl-exPRL(2016)·108 citations
23. 23*

    Constraints on the Photon Mass with Fast Radio Bursts

    Xue-Feng Wu🇨🇳 · Song-Bo Zhang🇨🇳 · He Gao🇨🇳 · Jun-Jie Wei🇨🇳 · Yuan-Chuan Zou🇨🇳 · Wei-Hua Lei🇨🇳 · Bing Zhang🇺🇸 · Zi-Gao Dai🇨🇳 · Peter Mészáros🇺🇸

    Fast radio bursts (FRBs) are radio bursts characterized by millisecond durations, high Galactic latitude positions, and high dispersion measures. Very recently, the cosmological origin of FRB 150418 has been confirmed by \cite{kea16}, and FRBs are now strong competitors as cosmological probes. The simple sharp feature of the FRB signal is ideal for them to probe some of the fundamental laws of physics. Here we show that by analyzing the delay time between different frequencies, the FRB data can place stringent upper limits on the rest mass of the photon. For FRB 150418 at $z=0.492$, one can potentially reach $m_{\gamma }\le 5.2\times 10^{-47}$ g, which is $10^{20}$ times smaller than the rest mass of electron, and is about $10^3$ times smaller than that obtained using other astrophysical sources with the same method.

    ↳ astro-ph.HEgr-qchep-phApJL(2016)·95 citations
24. 24*

    Generalized Pole Inflation: Hilltop, Natural, and Chaotic Inflationary Attractors

    Takahiro Terada🇰🇷

    A reformulation of inflationary model analyses appeared recently, in which inflationary observables are determined by the structure of a pole in the inflaton kinetic term rather than the shape of the inflaton potential. We comprehensively study this framework with an arbitrary order of the pole taking into account possible additional poles in the kinetic term or in the potential. Depending on the setup, the canonical potential becomes the form of hilltop or plateau models, variants of natural inflation, power-law inflation, or monomial/polynomial chaotic inflation. We demonstrate attractor behaviors of these models and compute corrections from the additional poles to the inflationary observables.

    ↳ hep-thastro-ph.COgr-qchep-phPLB(2016)·71 citations
25. 25*

    General Spin Precession and Betatron Oscillation in Storage Ring

    Takeshi Fukuyama🇯🇵

    We give the geralized expression of spin precession of extended bunch particles having both anomalous magnetic and electric dipole moments in storage ring. The transversal betatron oscillation formula of the bunch is also given. The latter is the generalization of the Farley's pitch correction \cite{Farley}, including radial oscillation as well as vertical one. Some useful formulae for muon storage ring are discussed in appendix.

    ↳ physics.acc-phhep-exhep-phMod.Phys.Lett.A(2016)·8 citations
26. 26*

    Turning on gravity with the Higgs mechanism

    Stephon Alexander🇺🇸 · John D. Barrow🇬🇧 · Joao Magueijo🇬🇧

    We investigate how a Higgs mechanism could be responsible for the emergence of gravity in extensions of Einstein theory. In this scenario, at high energies, symmetry restoration could "turn off" gravity, with dramatic implications for cosmology and quantum gravity. The sense in which gravity is muted depends on the details of the implementation. In the most extreme case gravity's dynamical degrees of freedom would only be unleashed after the Higgs field acquires a non-trivial vacuum expectation value, with gravity reduced to a topological field theory in the symmetric phase. We might also identify the Higgs and the Brans-Dicke fields in such a way that in the unbroken phase Newton's constant vanishes, decoupling matter and gravity. We discuss the broad implications of these scenarios.

    ↳ gr-qcastro-ph.COhep-phhep-thClass.Quant.Grav.(2016)·11 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.