Fri·May 26, 2017Friday·May 26, 2017

1. 01*

   Analytic continuation and numerical evaluation of the kite integral and the equal mass sunrise integral

   Christian Bogner🇩🇪 · Armin Schweitzer🇩🇪 · Stefan Weinzierl🇩🇪

   We study the analytic continuation of Feynman integrals from the kite family, expressed in terms of elliptic generalisations of (multiple) polylogarithms. Expressed in this way, the Feynman integrals are functions of two periods of an elliptic curve. We show that all what is required is just the analytic continuation of these two periods. We present an explicit formula for the two periods for all values of $t\in \mathbb{R}$. Furthermore, the nome $q$ of the elliptic curve satisfies over the complete range in $t$ the inequality $|q|\le 1$, where $|q|=1$ is attained only at the singular points $t\in \{m^2,9m^2,\infty \}$. This ensures the convergence of the $q$-series expansion of the $\mathrm{ELi}$-functions and provides a fast and efficient evaluation of these Feynman integrals.

   hep-phhep-thmath-phmath.MPNPB(2017)·98 citations
2. 02*

   Tree-level vacuum stability of two-Higgs-doublet models and new constraints on the scalar potential

   Xun-Jie Xu🇩🇪

   The scalar potential of the two-Higgs-doublet model (2HDM) may have more than one local minimum and the usually considered vacuum could be located at one of them that could decay to another. This paper studies the condition that the usually considered vacuum is the global minimum which, combined with the bounded-from-below condition, will stabilize the vacuum at tree-level. We further apply these conditions to a specific 2HDM and obtain new constraints which could be important in phenomenological studies.

   hep-phPRD(2017)·22 citations
3. 03*

   A QFT-induced phase in neutrino flavour oscillations

   Dharam Vir Ahluwalia🇮🇳 · Cheng-Yang Lee🇮🇳

   In the extended Standard Model of particle physics, each neutrino mass eigenstate is predicted to have a tiny but non vanishing magnetic moment induced by quantum field theoretic corrections. These QFT-induced magnetic momenta depend linearly on masses of the underlying mass eigenstates with a proportionality constant $3e{G}_F/(8\sqrt{2}{\pi }^2)$. As a consequence when neutrinos are embedded in an environment containing magnetic fields the flavour oscillations get a contribution from the induced relative phases.

   hep-phnucl-thEPL(2017)·3 citations
4. 04*

   Locating the QCD critical endpoint through finite-size scaling

   N.G.Antoniou🇬🇷 · F.K.Diakonos🇬🇷 · X.N.Maintas🇬🇷 · C.E.Tsagkarakis🇬🇷

   Considering the 3d Ising universality class of the QCD critical endpoint we use a universal effective action for the description of the baryon-number density fluctuations around the critical region. Calculating the baryon-number multiplicity moments and determining their scaling with system's size we show that the critical region is very narrow in the direction of the baryon chemical potential $\mu$ and wide in the temperature direction $T$ for $T>T_c$. In this context, published experimental results on local proton density-fluctuation measurements obtained by intermittency analysis in transverse momentum space in NA49 central A+A collisions at $\sqrt{s_{NN}}=17.2$ GeV (A=C,Si,Pb), restrict significantly the location $({\mu }_c,T_c)$ of the QCD critical endpoint. The main constraint is provided by the freeze-out chemical potential of the Si+Si system, which shows non-conventional baryon density fluctuations, restricting $({\mu }_c,T_c)$ within a narrow domain, $119\text{MeV}\le T_c\le 162\text{MeV}$, $252\text{MeV}\le {\mu }_c\le 258\text{MeV}$, of the phase diagram.

   hep-phPRD(2018)·42 citations
5. 05*

   The hard Pomeron impact on the high-energy elastic scattering of nucleons

   A.A. Godizov🇷🇺

   The role of the hard Pomeron (HP) exchanges in the high-energy diffractive interaction of nucleons is explored. It is demonstrated that the HP subdominance at available energies and low transferred momenta is due to the extremely low slope of its Regge trajectory.

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

   Momentum-space resummation for transverse observables and the Higgs $p_{\perp }$ at N${}^3$LL+NNLO

   Wojciech Bizon🇬🇧 · Pier Francesco Monni🇨🇭 · Emanuele Re🇨🇭 · Luca Rottoli🇬🇧 · Paolo Torrielli🇮🇹

   We present an approach to the momentum-space resummation of global, recursive infrared and collinear safe observables featuring kinematic zeros away from the Sudakov limit. In the hadro-production of a generic colour singlet, we consider the family of inclusive observables which do not depend on the rapidity of the radiation, prime examples being the transverse momentum of the singlet, and ${\varphi }^{\ast }$ in Drell-Yan pair production. We derive a resummation formula valid up to next-to-next-to-next-to-leading-logaritmic accuracy for the considered observables. This formula reduces exactly to the customary resummation performed in impact-parameter space in the known cases, and it also predicts the correct power-behaved scaling of the cross section in the limit of small value of the observable. We show how this formalism is efficiently implemented by means of Monte Carlo techniques in a fully exclusive generator that allows one to apply arbitrary cuts on the Born variables for any colour singlet, as well as to automatically match the resummed results to fixed-order calculations. As a phenomenological application, we present state-of-the-art predictions for the Higgs-boson transverse-momentum spectrum at the LHC at next-to-next-to-next-to-leading-logarithmic accuracy matched to fixed next-to-next-to-leading order.

   hep-phhep-exJHEP(2018)·165 citations
7. 07*

   Atmospheric neutrinos and new physics

   Nuria Rius🇪🇸

   We discuss recent searches for new physics using high-energy atmospheric neutrino data from IceCube, namely sterile neutrinos with masses in the range $\Delta m^2=0.01$ eV${}^2$ - 10 eV${}^2$, and non-standard interactions (NSI) in the ${\nu }_{\mu }-{\nu }_{\tau }$ sector. We also present a brief review of the current status of NSI theory and phenomenology.

   hep-ph0 citations
8. 08*

   Status and prospects of light bino-higgsino dark matter in natural SUSY

   Murat Abdughani🇨🇳 · Lei Wu🇨🇳 · Jin Min Yang🇨🇳

   Given the recent progress in dark matter direction detection experiments, we examine a light bino-higgsino dark matter (DM) scenario ($M_1<100$ GeV and $\mu <300$ GeV) in natural supersymmetry with the electroweak fine tuning measure ${\Delta }_{EW}<30$. By imposing various constraints, we note that: (i) For $sign(\mu /M_1)=+1$, the parameter space allowed by the DM relic density and collider bounds can almost be excluded by the very recent spin-independent (SI) scattering cross section limits from the XENON1T (2017) experiment. (ii) For $sign(\mu /M_1)=-1$, the SI limits can be evaded due to the cancelation effects in the $h{\tilde{\chi }}_1^0{\tilde{\chi }}_1^0$ coupling, while rather stringent constraints come from the PandaX-II (2016) spin-dependent (SD) scattering cross section limits, which can exclude the higgsino mass $|\mu |$ and the LSP mass $m_{{\tilde{\chi }}_1^0}$ up to about 230 GeV and 37 GeV, respectively. Furthermore, the surviving parameter space will be fully covered by the projected XENON1T experiment or the future trilepton searches at the HL-LHC.

   hep-phEPJC(2018)·64 citations
9. 09*

   One More Hard Three-Loop Correction to Parapositronium Energy Levels

   Michael I. Eides🇺🇸 · Valery A. Shelyuto🇷🇺

   A hard three-loop correction to parapositronium energy levels of order $m{\alpha }^7$ is calculated. This nonlogarithmic contribution is due to the insertions of one-loop photon propagator in the fermion lines in the diagrams with virtual two-photon annihilation. We obtained $\Delta E=0.03297(2)(m{\alpha }^7/{\pi }^3)$ for this energy shift.

   hep-phphysics.atom-phPRD(2017)·17 citations
10. 10*

    The Higgs Vacuum Uplifted: Revisiting the Electroweak Phase Transition with a Second Higgs Doublet

    G. C. Dorsch🇩🇪 · S. J. Huber🇬🇧 · K. Mimasu🇧🇪 · J. M. No🇬🇧

    The existence of a second Higgs doublet in Nature could lead to a cosmological first order electroweak phase transition and explain the origin of the matter-antimatter asymmetry in the Universe. We explore the parameter space of such a two-Higgs-doublet-model and show that a first order electroweak phase transition strongly correlates with a significant uplifting of the Higgs vacuum w.r.t. its Standard Model value. We then obtain the spectrum and properties of the new scalars $H_0$, $A_0$ and $H^{\pm }$ that signal such a phase transition, showing that the decay $A_0\to H_{0}Z$ at the LHC and a sizable deviation in the Higgs self-coupling ${\lambda }_{hhh}$ from its SM value are sensitive indicators of a strongly first order electroweak phase transition in the 2HDM.

    hep-phJHEP(2017)·105 citations
11. 11*

    Scrutinizing $R$-parity violating interactions in light of $R_{K^{(\ast )}}$ data

    Diganta Das🇮🇳 · Chandan Hati🇮🇳 · Girish Kumar🇮🇳 · Namit Mahajan🇮🇳

    The LHCb has measured the ratios of $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$ to $B\to K^{\ast }{e}^{+}{e}^{-}$ branching fractions in two dilepton invariant mass squared bins, which deviate from the Standard Model predictions by approximately $2.5\sigma$. These new measurements strengthen the hint of lepton flavor universality breaking which was observed earlier in $B\to K{\ell }^{+}{\ell }^{-}$ decays. In this work we explore the possibility of explaining these anomalies within the framework of $R$-parity violating interactions. In this framework, $b\to s{\ell }^{+}{\ell }^{-}$ transitions are generated through tree and one loop diagrams involving exchange of down-type right-handed squarks, up-type left-handed squarks and left-handed sneutrinos. We find that the tree level contributions are not enough to explain the anomalies, but at one loop, simultaneous explanation of the deviations in $B\to K^{\ast }{\ell }^{+}{\ell }^{-}$ and $B\to K{\ell }^{+}{\ell }^{-}$ is feasible for a parameter space of the Yukawa couplings that is consistent with the bounds coming from $B\to K^{(\ast )}\nu \bar{\nu }$ and $D^0\to {\mu }^{+}{\mu }^{-}$ decays and $B_s-{\bar{B}}_s$ mixing.

    hep-phPRD(2017)·63 citations
12. 12*

    Light Sterile Neutrinos at $\nu$STORM: Decoherence and CP violation

    Peter Ballett🇬🇧 · Matheus Hostert🇬🇧 · Silvia Pascoli🇬🇧

    Light sterile neutrino oscillations can be partially or completely washed out at short-baseline experiments due to the breaking of neutrino production coherence. In this work we address this issue in sterile searches at $\nu$STORM, an experimental proposal for a beam of neutrinos from the decay of stored muons. We work with 3+1 and 3+2 models, the latter introducing CP violation at short-baselines. We find that decoherence effects are only relevant for sterile masses above $\Delta m^2\gtrsim 10$ eV${}^2$, and that, even in that regime, we are able to place strong appearance bounds in such clean environments. In addition, the novel signatures of CP violation in the parameter space of interest can be identified with a significance of up to $\gtrsim 3\sigma$.

    hep-ph1 citation
13. 13*

    Study of the $DKK$ and $DK\bar{K}$ systems

    V. R. Debastiani🇪🇸 · J. M. Dias🇪🇸 · E. Oset🇪🇸

    Using the Fixed Center Approximation to Faddeev equations we have investigated the $DKK$ and $DK\bar{K}$ three-body systems, considering that the $DK$ dynamically generates, through its $I=0$ component, the $D_{s0}^{\ast }(2317)$ molecule. According to our findings, for $DK\bar{K}$ interaction we have found an evidence of a state $I(J^P)=1/2(0^{-})$ just above the $D_{s0}^{\ast }(2317)\bar{K}$ threshold and around the $D{f}_0(980)$ thresholds, with mass about $2833-2858$ MeV, made mostly of $D{f}_0(980)$. On the other hand, no evidence related to a state from the $DKK$ interaction is found. The state found could be seen in the $\pi \pi D$ invariant mass.

    hep-phPRD(2017)·29 citations
14. 14*

    Revisiting Minimal Lepton Flavour Violation in the Light of Leptonic CP Violation

    D.N. Dinh🇻🇳 · L. Merlo🇪🇸 · S.T. Petcov🇮🇹 · R. Vega-Alvarez🇪🇸

    The Minimal Lepton Flavour Violation (MLFV) framework is discussed after the recent indication for CP violation in the leptonic sector. Among the three distinct versions of MLFV, the one with degenerate right-handed neutrinos will be disfavoured, if this indication is confirmed. The predictions for leptonic radiative rare decays and muon conversion in nuclei are analysed, identifying strategies to disentangle the different MLFV scenarios. The claim that the present anomalies in the semi-leptonic $B$-meson decays can be explained within the MLFV context is critically re-examined concluding that such an explanation is not compatible with the present bounds from purely leptonic processes.

    hep-phJHEP(2017)·41 citations
15. 15*

    Coannihilation without chemical equilibrium

    Mathias Garny🇩🇪 · Jan Heisig🇩🇪 · Benedikt Lülf🇩🇪 · Stefan Vogl🇩🇪

    Chemical equilibrium is a commonly made assumption in the freeze-out calculation of coannihilating dark matter. We explore the possible failure of this assumption and find a new conversion-driven freeze-out mechanism. Considering a representative simplified model inspired by supersymmetry with a neutralino- and sbottom-like particle we find regions in parameter space with very small couplings accommodating the measured relic density. In this region freeze-out takes place out of chemical equilibrium and dark matter self-annihilation is thoroughly inefficient. The relic density is governed primarily by the size of the conversion terms in the Boltzmann equations. Due to the small dark matter coupling the parameter region is immune to direct detection but predicts an interesting signature of disappearing tracks or displaced vertices at the LHC. Unlike freeze-in or superWIMP scenarios, conversion-driven freeze-out is not sensitive to the initial conditions at the end of reheating.

    hep-phastro-ph.COPRD(2017)·137 citations
16. 16*

    Unitarity Constraints on Dimension-six Operators II: Including Fermionic Operators

    Tyler Corbett🇦🇺 · O. J. P. Éboli🇧🇷 · M. C. Gonzalez-Garcia🇪🇸

    We analyze the scattering of fermions, Higgs and electroweak gauge bosons in order to obtain the partial-wave unitarity bounds on dimension-six effective operators, including those involving fermions. We also quantify whether, at the LHC energies, the dimension-six operators lead to unitarity violation after taking into account the presently available constraints on their Wilson coefficients. Our results show that for most dimension-six operators relevant for the LHC physics there is no unitarity violation at the LHC energies, and consequently, there is no need for the introduction of form factors in the experimental and phenomenological analyses, making them model independent. We also identify two operators for which unitarity violation is still an issue at the LHC Run-II.

    hep-phPRD(2017)·66 citations
17. 17*

    Light-quarks Yukawa couplings and new physics in exclusive high-$p_T$ Higgs + jet and Higgs + $b$-jet events

    Jonathan Cohen🇮🇱 · Shaouly Bar-Shalom🇮🇱 · Gad Eilam🇮🇱 · Amarjit Soni🇺🇸

    We suggest that the exclusive Higgs + light (or b)-jet production at the LHC, $pp\to h+j(j_b)$, is a rather sensitive probe of the light-quarks Yukawa couplings and of other forms of new physics (NP) in the Higgs-gluon $hgg$ and quark-gluon $qqg$ interactions. We study the Higgs $p_T$-distribution in $pp\to h+j(j_b)\to \gamma \gamma +j(j_b)$, i.e., in $h+j(j_b)$ production followed by the Higgs decay $h\to \gamma \gamma$, employing the ($p_T$-dependent) signal strength formalism to probe various types of NP which are relevant to these processes and which we parameterize either as scaled Standard Model (SM) couplings (the kappa-framework) and/or through new higher dimensional effective operators (the SMEFT framework). We find that the exclusive $h+j(j_b)$ production at the 13 TeV LHC is sensitive to various NP scenarios, with typical scales ranging from a few TeV to $\mathcal{O}(10)$ TeV, depending on the flavor, chirality and Lorentz structure of the underlying physics.

    hep-phhep-exPRD(2018)·19 citations
18. 18*

    Role of Tensor operators in $R_K$ and $R_{K^{\ast }}$

    Debjyoti Bardhan🇮🇳 · Pritibhajan Byakti🇮🇳 · Diptimoy Ghosh🇮🇱

    The recent LHCb measurement of $R_{K^{\ast }}$ in two $q^2$ bins, when combined with the earlier measurement of $R_K$, strongly suggests lepton flavour non-universal new physics in semi-leptonic $B$ meson decays. Motivated by these intriguing hints of new physics, several authors have considered vector, axial vector, scalar and pseudo scalar operators as possible explanations of these measurements. However, tensor operators have widely been neglected in this context. In this paper, we consider the effect of tensor operators in $R_K$ and $R_{K^{\ast }}$. We find that, unlike other local operators, tensor operators can comfortably produce both of $R_{K^{\ast }}^{\mathrm{low}}$ and $R_{K^{\ast }}^{\mathrm{central}}$ close to their experimental central values. However, a simultaneous explanation of $R_K$ is not possible with only Tensor operators, and other vector or axial vector operators are needed. In fact, we find that combination of vector and tensor operators can provide simultaneous explanations of all the anomalies comfortably at the $1\sigma$ level, a scenario which is hard to achieve with only vector or axial vector operators. We also comment on the compatibility of the various new physics solutions with the measurements of the inclusive decay $B_d\to X_s{\ell }^{+}{\ell }^{-}$.

    hep-phhep-exPLB(2017)·66 citations
19. 19*

    A simple extension of SM that can explain the $(g-2{)}_{\mu }$ anomaly, small neutrino mass and a dark-matter

    Lobsang Dhargyal🇮🇳

    In this work we propose a simple extension of standard-model (SM) by adding eleven new particles to it. Three heavy leptons ($f_e,f_{\mu },f_{\tau }$) singlet under the $SU(3{)}_c\times SU(2{)}_L$ carrying respective Lepton-Numbers, charged under the $U(1{)}_Y$ with $Y=-2$ and transforming under a discrete symmetry as $f_i\to -f_i$. One scalar (${\varphi }_2$), singlet under all the SM gauge groups and transforming under the discrete symmetry as ${\varphi }_2\to -{\varphi }_2$ which does not develops a non zero vacuum-expectation-value (VEV). One more scalar (${\varphi }_3$), singlet under all the SM gauge groups and invariant under the discrete symmetry which develops a non zero VEV ($v_3$) and gives masses to $f_i$s, ${\varphi }_2$ and neutrinos. Three right-handed neutrinos (${\nu }_{iR}$) and three left-handed Majorana neutrinos ($s_{iL}$). With these new additional particles added to SM we have been able to give explanations to the long standing muon (g -2) anomaly as well as the smallness of neutrino masses by the inverse see-saw mechanism. And also in this model we have a very suitable scalar dark-matter (DM) candidate in ${\varphi }_2$ with allowed mass as high as 53 GeV, although due to large Yukawa coupling required to explain the muon (g-2), its contribution to the DM relic density turn out to be too small and so it can account only a small fraction of the DM relic density of the universe.

    hep-phJ.Phys.G(2018)·2 citations
20. 20*

    Mutual Interactions of Phonons, Rotons, and Gravity

    Alberto Nicolis🇺🇸 · Riccardo Penco🇺🇸

    We introduce an effective point-particle action for generic particles living in a zero-temperature superfluid. This action describes the motion of the particles in the medium at equilibrium as well as their couplings to sound waves and generic fluid flows. While we place the emphasis on elementary excitations such as phonons and rotons, our formalism applies also to macroscopic objects such as vortex rings and rigid bodies interacting with long-wavelength fluid modes. Within our approach, we reproduce phonon decay and phonon-phonon scattering as predicted using a purely field-theoretic description of phonons. We also correct classic results by Landau and Khalatnikov on roton-phonon scattering. Finally, we discuss how phonons and rotons couple to gravity, and show that the former tend to float while the latter tend to sink but with rather peculiar trajectories. Our formalism can be easily extended to include (general) relativistic effects and couplings to additional matter fields. As such, it can be relevant in contexts as diverse as neutron star physics and light dark matter detection.

    ↳ hep-thcond-mat.othercond-mat.quant-gasgr-qc+1PRB(2018)·41 citations
21. 21*

    An Etude on Global Vacuum Energy Sequester

    Guido D'Amico🇨🇭 · Nemanja Kaloper🇺🇸 · Antonio Padilla🇬🇧 · David Stefanyszyn🇳🇱 · Alexander Westphal🇩🇪 · George Zahariade🇺🇸

    Recently two of the authors proposed a mechanism of vacuum energy sequester as a means of protecting the observable cosmological constant from quantum radiative corrections. The original proposal was based on using global Lagrange multipliers, but later a local formulation was provided. Subsequently other interesting claims of a different non-local approach to the cosmological constant problem were made, based again on global Lagrange multipliers. We examine some of these proposals and find their mutual relationship. We explain that the proposals which do not treat the cosmological constant counterterm as a dynamical variable require fine tunings to have acceptable solutions. Furthermore, the counterterm often needs to be retuned at every order in the loop expansion to cancel the radiative corrections to the cosmological constant, just like in standard GR. These observations are an important reminder of just how the proposal of vacuum energy sequester avoids such problems.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2017)·29 citations
22. 22*

    Prediction of ultra-narrow Higgs resonance in magnon Bose-condensates

    H. D. Scammell🇦🇺 · O. P. Sushkov🇦🇺

    Higgs resonance modes in condensed matter systems are generally broad; meaning large decay widths or short relaxation times. This common feature has obscured and limited their observation to a select few systems. Contrary to this, the present work predicts that Higgs resonances in magnetic field induced, three-dimensional magnon Bose-condensates have vanishingly small decay widths. Specifically for parameters relating to TlCuCl${}_3$, we find an energy (${\Delta }_H$) to width (${\Gamma }_H$) ratio ${\Delta }_H/{\Gamma }_H\sim 500$, making this the narrowest predicted Higgs mode in a condensed matter system, some two orders of magnitude `narrower' than the sharpest condensed matter Higgs observed so far.

    ↳ cond-mat.str-elhep-ph1 citation
23. 23*

    Barnacles and Gravity

    James H. C. Scargill🇺🇸

    Theories with more than one vacuum allow quantum transitions between them, which may proceed via bubble nucleation; theories with more than two vacua posses additional decay modes in which the wall of a bubble may further decay. The instantons which mediate such a process have $O(3)$ symmetry (in four dimensions, rather than the usual $O(4)$ symmetry of homogeneous vacuum decay), and have been called `barnacles'; previously they have been studied in flat space, in the thin wall limit, and this paper extends the analysis to include gravity. It is found that there are regions of parameter space in which, given an initial bubble, barnacles are the favoured subsequent decay process, and that the inclusion of gravity can enlarge this region. The relation to other heterogeneous vacuum decay scenarios, as well as some of the phenomenological implications of barnacles are briefly discussed.

    ↳ gr-qcastro-ph.COhep-phhep-thJHEP(2017)·2 citations
24. 24*

    Effective Temperatures and Radiation Spectra for a Higher-Dimensional Schwarzschild-de-Sitter Black-Hole

    Panagiota Kanti🇬🇷 · Thomas Pappas🇬🇷

    The absence of a true thermodynamical equilibrium for an observer located in the causal area of a Schwarzschild-de Sitter spacetime has repeatedly raised the question of the correct definition of its temperature. In this work, we consider five different temperatures for a higher-dimensional Schwarzschild-de Sitter black hole: the bare $T_0$, the normalised $T_{BH}$ and three effective ones given in terms of both the black hole and cosmological horizon temperatures. We find that these five temperatures exhibit similarities but also significant differences in their behaviour as the number of extra dimensions and the value of the cosmological constant are varied. We then investigate their effect on the energy emission spectra of Hawking radiation. We demonstrate that the radiation spectra for the normalised temperature $T_{BH}$ -- proposed by Bousso and Hawking over twenty years ago -- leads to the dominant emission curve while the other temperatures either support a significant emission rate only at a specific $\Lambda$ regime or they have their emission rates globally suppressed. Finally, we compute the bulk-over-brane emissivity ratio and show that the use of different temperatures may lead to different conclusions regarding the brane or bulk dominance.

    ↳ hep-thastro-ph.COgr-qchep-phPRD(2017)·47 citations
25. 25*

    $\overline{D3}$ Induced Geometric Inflation

    Renata Kallosh🇺🇸 · Andrei Linde🇺🇸 · Diederik Roest🇳🇱 · Yusuke Yamada🇺🇸

    Effective supergravity inflationary models induced by anti-D3 brane interaction with the moduli fields in the bulk geometry have a geometric description. The Kähler function carries the complete geometric information on the theory. The non-vanishing bisectional curvature plays an important role in the construction. The new geometric formalism, with the nilpotent superfield representing the anti-D3 brane, allows a powerful generalization of the existing inflationary models based on supergravity. They can easily incorporate arbitrary values of the Hubble parameter, cosmological constant and gravitino mass. We illustrate it by providing generalized versions of polynomial chaotic inflation, T- and E-models of $\alpha$-attractor type, disk merger. We also describe a multi-stage cosmological attractor regime, which we call cascade inflation.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2017)·80 citations
26. 26*

    Classical gluon and graviton radiation from the bi-adjoint scalar double copy

    Walter D. Goldberger🇺🇸 · Siddharth G. Prabhu🇺🇸 · Jedidiah O. Thompson🇺🇸

    We find double copy relations between classical radiating solutions in Yang-Mills theory coupled to dynamical color charges and their counterparts in a cubic bi-adjoint scalar field theory which interacts linearly with particles carrying bi-adjoint charge. The particular color-to-kinematics replacements we employ are motivated by the BCJ double copy correspondence for on-shell amplitudes in gauge and gravity theories. They are identical to those recently used to establish relations between classical radiating solutions in gauge theory and in dilaton gravity. Our explicit bi-adjoint solutions are constructed to second order in a perturbative expansion, and map under the double copy onto gauge theory solutions which involve at most cubic gluon self-interactions. If the correspondence is found to persist to higher orders in perturbation theory, our results suggest the possibility of calculating gravitational radiation from colliding compact objects, directly from a scalar field with vastly simpler (purely cubic) Feynman vertices.

    ↳ hep-thgr-qchep-phPRD(2017)·172 citations
27. 27*

    TeV Gamma Rays From Galactic Center Pulsars

    Dan Hooper🇺🇸 · Ilias Cholis🇺🇸 · Tim Linden🇺🇸

    Measurements of the nearby pulsars Geminga and B0656+14 by the HAWC and Milagro telescopes have revealed the presence of bright TeV-emitting halos surrounding these objects. If young and middle-aged pulsars near the Galactic Center transfer a similar fraction of their energy into TeV photons, then these sources could plausibly dominate the emission that is observed by HESS and other ground-based telescopes from the innermost $\sim$$10^2$ parsecs of the Milky Way. In particular, both the spectral shape and the angular extent of this emission is consistent with TeV halos produced by a population of pulsars, although the reported correlation of this emission with the distribution of molecular gas suggests that diffuse hadronic processes also must contribute. The overall flux of this emission requires a birth rate of ~100-1000 neutron stars per Myr near the Galactic Center, in good agreement with recent estimates.

    ↳ astro-ph.HEastro-ph.GAhep-phPhys.Dark Univ.(2018)·25 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.