Thu·Jun 14, 2018Thursday·June 14, 2018

1. 01*

   Constraining anomalous gluon self-interactions at the LHC: a reappraisal

   V. Hirschi🇨🇭 · F. Maltoni🇧🇪 · I. Tsinikos🇩🇪 · E. Vryonidou🇨🇭

   Anomalous self-interactions of non-abelian gauge fields can be described by higher dimensional operators featuring gauge-invariant combinations of the field strengths. In the case of QCD, the gluon self-interactions start to be modified at dimension six by operators of the type $GGG$, with $G$ the gluon field strength tensor, possibly leading to deviations in all observables and measurements that probe strong interactions at very small distances. In this work we consider the sensitivity to the triple gluon operator of a series of observables at the LHC in di-jet, three- and multi-jet final states and heavy-quark production. We critically re-examine the robustness of long-standing as well as more recent proposals addressing issues such as the validity of the EFT expansion and the impact of higher order QCD corrections. Our results support the conclusion that multi-jet observables can reliably bound these anomalous interactions to the level that their impact on other key observables at the LHC, involving for example top quark and Higgs production, can be safely neglected. We also highlight the potential of using previously suggested angular observables in three-jet events at the LHC to further constrain these interactions.

   hep-phJHEP(2018)·49 citations
2. 02*

   Color randomization of fast gluon-gluon pairs in the quark-gluon plasma

   B.G. Zakharov🇷🇺

   We study the color randomization of two-gluon states produced after splitting of a primary fast gluon in the quark-gluon plasma. We find that for the LHC conditions the color randomization of the $gg$ pairs is rather slow. At jet energies $E=100$ and $500$ GeV, for typical jet path length in the plasma in central Pb+Pb collisions, the $SU(3)$-multiplet averaged color Casimir of the $gg$ pair differs considerably from its value $2N_c$ for a fully randomized $gg$ state. Our calculations of the energy dependence for generation of the nearly collinear decuplet $gg$ states, that can lead to the baryon jet fragmentation, show that the contribution of the anomalous decuplet color states to the baryon production should become small at $p_T\gtrsim 10$ GeV.

   hep-phnucl-thJ.Exp.Theor.Phys.(2019)·13 citations
3. 03*

   Sub-GeV Dark Matter Shining at Future MeV Gamma-Ray Telescopes

   Francesco D'Eramo🇮🇹 · Stefano Profumo🇺🇸

   We propose a novel framework where light (sub-GeV) dark matter (DM) is detectable with future MeV gamma-ray telescopes without conflicting with Cosmic Microwave Background (CMB) data. The stable DM particle $\chi$ has a very low thermal relic abundance due to its large pair-annihilation cross section. The DM number density is stored in a heavier, meta-stable partner $\psi$ with suppressed pair-annihilation rates, that does not perturb the CMB, and whose late-time decays $\psi \to \chi$ fill the universe with $\chi$ DM particles. We provide explicit, model-independent realizations for this framework, and discuss constraints on late-time decays, and thus on parameters of this setup, from CMB, Big Bang Nucleosynthesis, and Large Scale Structure.

   hep-phastro-ph.COPRL(2018)·17 citations
4. 04*

   Hollowness in $pp$ and $p\bar{p}$ scattering in a Regge model

   Wojciech Broniowski🇵🇱 · László Jenkovszky🇺🇦 · Enrique Ruiz Arriola🇪🇸 · István Szanyi🇺🇦

   The proton-proton and proton-antiproton inelasticity profiles in the impact parameter display very interesting and sensitive features which cannot be deduced solely from the current large body of high-energy scattering data. In particular, phenomenological studies exhibit a link between the ratio of the real to imaginary parts of the elastic scattering amplitude at a finite momentum transfer, and the corresponding change of character of the inelastic processes from central to peripheral collisions. We describe how a theoretical model, accommodating the existing data, based on the Regge hypothesis including both the Pomeron and odderon as double poles, and $\omega$ and $f$ mesons as single poles in the complex-$J$ plane, generates a hollow in the inelasticity at low impact parameters. The hollowness effect, which generally may be sensitive to model details, does unequivocally take place both for $pp$ and $p\bar{p}$ collisions within the applied Regge framework, indicating inapplicability of inelasticity-folding geometric approaches.

   hep-phnucl-thPRD(2018)·47 citations
5. 05*

   Flavor Changing Neutral Currents in the Asymmetric Left-Right Gauge Model

   Chia-Feng Chang🇺🇸 · Ernest Ma🇺🇸

   In the $SU(3{)}_C\times SU(2{)}_L\times SU(2{)}_R\times U(1{)}_{(B-L)/2}$ extension of the standard model, a minimal (but asymmetric) scalar sector consists of one $SU(2{)}_R\times U(1{)}_{(B-L)/2}$ doublet and one $SU(2{)}_L\times SU(2{)}_R$ bidoublet. Previous and recent studies have shown that this choice is useful for understanding neutrino mass as well as dark matter. The constraints from flavor changing neutral currents mediated by the scalar sector are discussed in the context of the latest experimental data.

   hep-phJHEP(2018)·2 citations
6. 06*

   Two-photon exchange effects in $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ and time-like pion electromagnetic form factor

   Hong-Yu Chen🇨🇳 · Hai-Qing Zhou🇨🇳

   The two-photon-exchange (TPE) effects in the process $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ at large momentum transfer are discussed within the perturbative QCD (pQCD). The contributions from the twist-2 and twist-3 distribution amplitudes (DAs) of pion are considered in the estimation. Different with the results under the one-photon-exchange (OPE) approximation, the TPE effects result in an asymmetry of the differential cross section on the scattering angle. The precise measurement of this asymmetry by the further experiment is an precise test of pQCD at large momentum transfer. The time-like electromagnetic form factor of pion at the leading order of pQCD is re-discussed and the comparison of our results with those in the references are presented.

   hep-phhep-exnucl-thPRD(2018)·7 citations
7. 07*

   Symmetric $ϵ$- and $(ϵ+1/2)$-forms and quadratic constraints in "elliptic" sectors

   Roman N. Lee🇷🇺

   Within the differential equation method for multiloop calculations, we examine the systems irreducible to $ϵ$-form. We argue that for many cases of such systems it is possible to obtain nontrivial quadratic constraints on the coefficients of $ϵ$-expansion of their homogeneous solutions. These constraints are the direct consequence of the existence of symmetric $(ϵ+1/2)$-form of the homogeneous differential system, i.e., the form where the matrix in the right-hand side is symmetric and its $ϵ$-dependence is localized in the overall factor $(ϵ+1/2)$. The existence of such a form can be constructively checked by available methods and seems to be common to many irreducible systems, which we demonstrate on several examples. The obtained constraints provide a nontrivial insight on the structure of general solution in the case of the systems irreducible to $ϵ$-form. For the systems reducible to $ϵ$-form we also observe the existence of symmetric form and derive the corresponding quadratic constraints.

   hep-phJHEP(2018)·29 citations
8. 08*

   Centrality dependent long-range angular correlations of intermediate-pT D-mesons and charged particles in pPb collisions at the LHC energy

   Somnath Kar🇨🇳 · Subikash Choudhury🇨🇳 · Samrangy Sadhu🇮🇳 · Premomoy Ghosh🇮🇳

   The high-multiplicity events of pPb collisions at ${\sqrt{s}}_{NN}$ = 5.02 TeV at the LHC exhibit unforeseen collective behaviour. One of the possible explanations to the collectivity could be the formation of thermalized partonic matter, like the one formed in relativistic nucleus-nucleus collisions and is described by the hydrodynamic models. This article presents a study on the centrality dependent long-range 2 < $|\Delta \eta |$ < 4 two-particle azimuthal correlations of D-mesons and charged particles in pPb collisions at ${\sqrt{s}}_{NN}$ = 5.02 TeV. The study has been conducted on the events, generated with the EPOS3 hydrodynamic code that reproduces most of the features of the pPb data at the LHC energy. There appears a ridge-like structure in the long-range two-particle angular correlations of D-mesons, in the intermediate pT -range, and charged particles in the simulated high-multiplicity pPb events.

   hep-phhep-exJ.Phys.G(2018)·4 citations
9. 09*

   Transition magnetic moments of $J^P={\frac{3}{2}}^{+}$ decuplet to $J^P={\frac{1}{2}}^{+}$ octet baryons in the chiral constituent quark model

   Harleen Dahiya🇮🇳

   In light of the developments of the chiral constituent quark model ($\chi$CQM) in studying low energy hadronic matrix elements of the ground-state baryons, we have extended this model to investigate their transition properties. The magnetic moments of transitions from the $J^P={\frac{3}{2}}^{+}$ decuplet to $J^P={\frac{1}{2}}^{+}$ octet baryons have been calculated with explicit valence quark spin, sea quark spin and sea quark orbital angular momentum contributions. Since the experimental data is available for only a few transitions, we have compared our results with the results of other available models. The implications of other complicated effects such as chiral symmetry breaking and SU(3) symmetry breaking arising due to confinement of quarks have also been discussed.

   hep-phnucl-thCPC(2018)·17 citations
10. 10*

    Cosmological Phase Transitions in Warped Space: Gravitational Waves and Collider Signatures

    Eugenio Megias🇪🇸 · Germano Nardini🇨🇭 · Mariano Quiros🇪🇸

    We study the electroweak phase transition within a 5D warped model including a scalar potential with an exponential behavior, and strong back-reaction over the metric, in the infrared. By means of a novel treatment of the superpotential formalism, we explore parameter regions that were previously inaccessible. We find that for large enough values of the t'Hooft parameter (e.g. $N\simeq 25$) the holographic phase transition occurs, and it can force the Higgs to undergo a first order electroweak phase transition, suitable for electroweak baryogenesis. The model exhibits gravitational waves and colliders signatures. It typically predicts a stochastic gravitational wave background observable both at the Laser Interferometer Space Antenna and at the Einstein Telescope. Moreover the radion tends to be heavy enough such that it evades current constraints, but may show up in future LHC runs.

    hep-phgr-qchep-thJHEP(2018)·99 citations
11. 11*

    Simultaneous extractions of $|V_{ub}|$ and $|V_{cb}|$ with only the exclusive ${\Lambda }_b$ decays

    Y.K. Hsiao🇨🇳 · C.Q. Geng🇨🇳

    We perform the simultaneous $|V_{ub}|$ and $|V_{cb}|$ extractions with only the exclusive ${\Lambda }_b$ decays of ${\Lambda }_b\to (p,{\Lambda }_c^{+})\mu {\bar{\nu }}_{\mu }$, ${\Lambda }_b\to p{\pi }^{-}$ and ${\Lambda }_b\to {\Lambda }_c^{+}({\pi }^{-},D^{-})$. We obtain that $|V_{ub}|=(3.7\pm 0.3)\times 10^{-3}$ and $|V_{cb}|=(45.9\pm 2.7)\times 10^{-3}$. Our value of $|V_{ub}|$ is larger than that of $(3.27\pm 0.15\pm 0.16\pm 0.06)\times 10^{-3}$, previously extracted by the LHC Collaboration from the exclusive ${\Lambda }_b$ decays also, but nearly identical to $(3.72\pm 0.19)\times 10^{-3}$ from the exclusive $B$ decays. On the other hand, our extracted result of $|V_{cb}|$ favors the value of $(42.2\pm 0.8)\times 10^{-3}$ from the inclusive $B$ decays.

    hep-phhep-exPLB(2018)·6 citations
12. 12*

    Analytic results for the planar double box integral relevant to top-pair production with a closed top loop

    Luise Adams🇩🇪 · Ekta Chaubey🇩🇪 · Stefan Weinzierl🇩🇪

    In this article we give the details on the analytic calculation of the master integrals for the planar double box integral relevant to top-pair production with a closed top loop. We show that these integrals can be computed systematically to all order in the dimensional regularisation parameter $\epsilon$. This is done by transforming the system of differential equations into a form linear in $\epsilon$, where the ${\epsilon }^0$-part is a strictly lower triangular matrix. Explicit results in terms of iterated integrals are presented for the terms relevant to NNLO calculations.

    hep-phhep-thJHEP(2018)·107 citations
13. 13*

    QCD and High Energy Interactions: Moriond 2018 Theory Summary

    Gudrun Heinrich🇩🇪

    The highlights of the theory developments presented at the Rencontres de Moriond 2018 on QCD and High Energy Interactions are summarised and put into perspective.

    hep-ph1 citation
14. 14*

    JUNO Sensitivity to Resonant Absorption of Galactic Supernova Neutrinos by Dark Matter

    Tarso Franarin🇬🇧 · Malcolm Fairbairn🇬🇧 · Jonathan H. Davis🇬🇧

    Resonant interactions between neutrinos from a Galactic supernova and dark matter particles can lead to a sharp dip in the neutrino energy spectrum. Due to its excellent energy resolution, measurement of this effect with the JUNO experiment can provide evidence for such couplings. We discuss how JUNO may confirm or further constrain a model where scalar dark matter couples to active neutrinos and another fermion.

    hep-ph13 citations
15. 15*

    Prospects of indirect searches for dark matter annihilations in the earth with ICAL@INO

    Deepak Tiwari🇮🇳 · Sandhya Choubey🇮🇳 · Anushree Ghosh🇨🇱

    We study the prospects of detecting muon events at the upcoming Iron CALorimeter (ICAL) detector to be built at the proposed India-based Neutrino Observatory (INO) facility due to neutrinos arising out of annihilation of Weakly Interactive Massive Particles (WIMP) in the centre of the earth. The atmospheric neutrinos coming from the direction of earth core presents an irreducible background. We consider 50kt $\times$ 10 years of ICAL running and WIMP masses between 10-100 GeV and present 90 \% C.L. exclusion sensitivity limits on ${\sigma }_{SI}$ which is the WIMP-nucleon Spin Independent (SI) interaction cross-section. The expected sensitivity limits calculated for ICAL for the WIMP annihilation in the earth are more stringent than the limits obtained by any other indirect detection experiment. For a WIMP mass of ~$52.14\text{ GeV}$, where the signal fluxes are enhanced due to resonance capture of WIMP in earth due to Fe nuclei, the sensitivity limits, assuming 100\% branching ratio for each channel, are : ${\sigma }_{SI}=1.02\times 10^{-44}c{m}^2$ for the ${\tau }^{+}{\tau }^{-}$ channel and ${\sigma }_{SI}=5.36\times 10^{-44}c{m}^2$ for the $b\bar{b}$ channel.

    hep-phhep-exJHEP(2019)·8 citations
16. 16*

    Exploring new physics contributions to $CP$ violation in ${\tau }^{-}\to K^{-}{\pi }^0{\nu }_{\tau }$

    David Delepine🇲🇽 · Gaber Faisel🇹🇷 · Carlos A. Ramirez🇨🇴

    A general analysis of possible violation of CP in processes like $\tau \to K\pi \nu$, for unpolarized $\tau$ is presented. In this paper, we derive the new contributions to the effective Hamiltonian governs $|\Delta S|=1$ semileptonic tau decays in the framework of two Higgs doublet model with generic Yukawa structure and Leptoquarks models. Within these models, we list all operators, in the effective Hamiltonian and provide analytical expression for their corresponding Wilson coefficients. Moreover, we analyze the role of the different contributions, originating from the scalar, vecor and tensor hadronic currents, in generating direct CP asymmetry in the decay rate of ${\tau }^{-}\to K^{-}{\pi }^0{\nu }_{\tau }$. We show that non vanishing direct CP asymmetry in the decay rate of ${\tau }^{-}\to K^{-}{\pi }^0{\nu }_{\tau }$ can be generated due to the presence of both, the weak phase in the Wilson coefficient corresponding to the tensor operator and the strong phase difference resulting from the interference between the form factors expressing the matrix elements of the vector and tensor hadronic currents. After taking into account all relevant constraints, we find that the generated direct CP asymmetry is of order $10^{-8}$ which is several orders of magnitude larger than the standard model prediction. We show also that, in two Higgs doublet model with generic Yukawa structure , direct local or non integrated CP violation can be as large as $0.3$ % not far from experimental possibilities. This kind of asymmetry can be generated due to the interference between vector and scalar contributions with different weak phases which is not the case in the SM.

    hep-phEPJC(2021)·10 citations
17. 17*

    The Energy-Dependent Black-Disk Fraction in Proton-Proton Scattering

    Dieter Schildknecht🇩🇪

    Recent work by Block et al on the energy-invariant edge in proton-proton scattering is interpreted by quantitatively introducing a energy-dependent black-disk fraction of the proton-proton interaction.

    hep-phPRD(2018)·2 citations
18. 18*

    The $X(4140)$ and $X(4160)$ resonances in the $e^{+}{e}^{-}\to \gamma J/\psi \varphi$ reaction

    En Wang🇨🇳 · Ju-Jun Xie🇨🇳 · Li-Sheng Geng🇨🇳 · Eulogio Oset🇪🇸

    We investigate the $J/\psi \varphi$ invariant mass distribution of the $e^{+}{e}^{-}\to \gamma J/\psi \varphi$ reaction at a center of mass energy of $\sqrt{s}=4.6$~GeV measured by the BESIII collaboration, who concludes that no significant signals are observed for $e^{+}{e}^{-}\to \gamma X(4140)$ because of the low statistics. We show, however, that the three bump structures in the $J/\psi \varphi$ invariant mass distribution, though given only by three data points, are compatible with the existence of the $X(4140)$ state, appearing as a peak, and a strong cusp structure at the $D_s^{\ast }{\bar{D}}_s^{\ast }$ threshold, resulting from the molecular nature of the $X(4160)$ state, which also provides a substantial contribution to the reaction. This is consistent with our previous analysis on the $B^{+}\to J/\psi \varphi K^{+}$ decay measured by the LHCb collaboration. We strongly call for the measurement of this process with more statistics to further pin down the nature of the $X(4140)$ and $X(4160)$ resonances.

    hep-phhep-exCPC(2019)·15 citations
19. 19*

    Higgs boson pair production in non-linear Effective Field Theory with full $m_t$-dependence at NLO QCD

    G.Buchalla🇩🇪 · M.Capozi🇩🇪 · A.Celis🇩🇪 · G.Heinrich🇩🇪 · L.Scyboz🇩🇪

    We present a calculation of the NLO QCD corrections to Higgs boson pair production within the framework of a non-linearly realised Effective Field Theory in the Higgs sector, described by the electroweak chiral Lagrangian. We analyse how the NLO corrections affect distributions in the Higgs boson pair invariant mass and the transverse momentum of one of the Higgs bosons. We find that these corrections lead to significant and non-homogeneous K-factors in certain regions of the parameter space. We also provide an analytical parametrisation for the total cross-section and the $m_{hh}$ distribution as a function of the anomalous Higgs couplings that includes NLO corrections. Such a parametrisation can be useful for phenomenological studies.

    hep-phJHEP(2018)·132 citations
20. 20*

    Extending the Universal One-Loop Effective Action by Regularization Scheme Translating Operators

    Benjamin Summ🇩🇪 · Alexander Voigt🇩🇪

    We extend the universal one-loop effective action (UOLEA) by operators which translate between dimensional reduction (DRED) and dimensional regularization (DREG). These regularization scheme translating operators allow for an application of the UOLEA to supersymmetric high-scale models matched to non-supersymmetric effective theories. The operators are presented in a generic, model independent form, suitable for implementation into generic spectrum generators.

    hep-phJHEP(2018)·21 citations
21. 21*

    Signatures of Pseudo-Dirac Dark Matter at High-Intensity Neutrino Experiments

    Johnathon R. Jordan🇺🇸 · Yonatan Kahn🇺🇸 · Gordan Krnjaic🇺🇸 · Matthew Moschella🇺🇸 · Joshua Spitz🇺🇸

    We (re)consider the sensitivity of past (LSND) and future (JSNS^2) beam dump neutrino experiments to two models of MeV-scale pseudo-Dirac dark matter. Both LSND and JSNS^2 are close (24-30 m) to intense sources of light neutral mesons which may decay to dark matter via interactions involving a light mediator or dipole operators. The dark matter can then scatter or decay inside of the nearby detector. We show that the higher beam energy of JSNS^2 and resulting $\eta$ production can improve on the reach of LSND for light-mediator models with dark matter masses greater than $m_{\pi }/2$. Further, we find that both existing LSND and future JSNS^2 measurements can severely constrain the viable parameter space for a recently-proposed model of dipole dark matter which could explain the 3.5 keV excess reported in observations of stacked galaxy clusters and the Galactic Center.

    hep-phhep-exPRD(2018)·62 citations
22. 22*

    Displaced vertices as probes of sterile neutrino mixing at the LHC

    Giovanna Cottin🇹🇼 · Juan Carlos Helo🇨🇱 · Martin Hirsch🇪🇸

    We investigate the reach at the LHC to probe light sterile neutrinos with displaced vertices. We focus on sterile neutrinos $N$ with masses $m_N\sim$ (5-30) GeV, that are produced in rare decays of the Standard Model gauge bosons and decay inside the inner trackers of the LHC detectors. With a strategy that triggers on the prompt lepton accompanying the $N$ displaced vertex and considers charged tracks associated to it, we show that the 13 TeV LHC with $3000$/fb is able to probe active-sterile neutrino mixings down to $|V_{lN}{|}^2\approx 10^{-9}$, with $l=e,\mu$, which is an improvement of up to four orders of magnitude when comparing with current experimental limits from trileptons and proposed lepton-jets searches. In the case when $\tau$ mixing is present, mixing angles as low as $|V_{\tau N}{|}^2\approx 10^{-8}$ can be accessed.

    hep-phhep-exPRD(2018)·95 citations
23. 23*

    De Sitter Quantum Loops as the origin of Primordial Non-Gaussianities

    Haipeng An🇨🇳 · Mark B. Wise🇺🇸 · Zipei Zhang🇨🇳

    It was pointed out recently that in some inflationary models quantum loops containing a scalar of mass $m$ that couples to the inflaton can be the dominant source of primordial non-Gaussianities. We explore this phenomenon in the simplest such model focusing on the behavior of the primordial curvature fluctuations for small $m/H$. Explicit calculations are done for the three and four point curvature fluctuation correlations. Constraints on the parameters of the model from the CMB limits on primordial non-Gaussianity are discussed. The bi-spectrum in the squeezed limit and the tri-spectrum in the compressed limit are examined. The form of the $n$-point correlations as any partial sum of wave vectors get small is determined.

    hep-phastro-ph.COhep-thPRD(2019)·13 citations
24. 24*

    The charm/bottom quark mass from heavy quarkonium at N${}^3$LO

    Clara Peset🇩🇪 · Antonio Pineda🇪🇸 · Jorge Segovia🇪🇸

    We determine the charm and bottom quark masses using the N${}^3$LO perturbative expression of the ground state (pseudoscalar) energy of the bottomonium, charmonium and $B_c$ systems: the ${\eta }_b$, ${\eta }_c$ and $B_c$ masses. We work in the renormalon subtracted scheme, which allows us to control the divergence of the perturbation series due to the pole mass renormalon. Our result for the $\overline{\mathrm{MS}}$ masses reads ${\overline{m}}_c({\overline{m}}_c)=1223(33)$ MeV and ${\overline{m}}_b({\overline{m}}_b)=4186(37)$ MeV. We also extract a value of ${\alpha }_s$ from a renormalon-free combination of the ${\eta }_b$, ${\eta }_c$ and $B_c$ masses: ${\alpha }_s(M_z)=0.1195(53)$. We explore the applicability of the weak coupling approximation to bottomonium $n=2$ states. Finally, we consider an alternative computational scheme that treats the static potential exactly and study its convergence properties.

    hep-phJHEP(2018)·68 citations
25. 25*

    Monodromy inflation and an emergent mechanism for stabilising the cosmological constant

    Antonio Padilla🇬🇧

    We show that a pair of field theory monodromies in which the shift symmetry is broken by small, well motivated deformations, naturally incorporates a mechanism for cancelling off radiative corrections to the cosmological constant. The lighter monodromy sector plays the role of inflation as well as providing a rigid degree of freedom that acts as a dynamical counterterm for the cosmological constant. The heavier monodromy sector includes a rigid dilaton that forces a global constraint on the system and the cancellation of vacuum energy loops occurs at low energies via the sequestering mechanism. This suggests that monodromy constructions in string theory could be adapted to incorporate mechanisms to stabilise the cosmological constant in their low energy descriptions.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2019)·13 citations
26. 26*

    First observation with global network of optical atomic clocks aimed for a dark matter detection

    P. Wcisło🇵🇱 · P. Ablewski🇵🇱 · K. Beloy🇺🇸 · S. Bilicki🇵🇱 · M. Bober🇵🇱 · R. Brown🇺🇸 · R. Fasano🇺🇸 · R. Ciuryło🇵🇱 · H. Hachisu🇯🇵 · T. Ido🇯🇵 · J. Lodewyck🇫🇷 · A. Ludlow🇺🇸 and 10 other authors

    We report on the first earth-scale quantum sensor network based on optical atomic clocks aimed at dark matter (DM) detection. Exploiting differences in the susceptibilities to the fine-structure constant of essential parts of an optical atomic clock, i.e. the cold atoms and the optical reference cavity, we can perform sensitive searches for dark matter signatures without the need of real-time comparisons of the clocks. We report a two orders of magnitude improvement in constraints on transient variations of the fine-structure constant, which considerably improves the detection limit for the standard model (SM) - DM coupling. We use Yb and Sr optical atomic clocks at four laboratories on three continents to search for both topological defect (TD) and massive scalar field candidates. No signal consistent with a dark-matter coupling is identified, leading to significantly improved constraints on the DM-SM couplings.

    ↳ physics.atom-phastro-ph.HEgr-qchep-phSci.Adv.(2018)·86 citations
27. 27*

    General Relativity from Scattering Amplitudes

    N. E. J. Bjerrum-Bohr🇩🇰 · Poul H. Damgaard🇩🇰 · Guido Festuccia🇸🇪 · Ludovic Planté🇫🇷 · Pierre Vanhove🇫🇷

    We outline the program to apply modern quantum field theory methods to calculate observables in classical general relativity through a truncation to classical terms of the multi-graviton two-body on-shell scattering amplitudes between massive fields. Since only long-distance interactions corresponding to non-analytic pieces need to be included, unitarity cuts provide substantial simplifications for both post-Newtonian and post-Minkowskian expansions. We illustrate this quantum field theoretic approach to classical general relativity by computing the interaction potentials to second order in the post-Newtonian expansion, as well as the scattering functions for two massive objects to second order in the post-Minkowskian expansion. We also derive an all-order exact result for gravitational light-by-light scattering.

    ↳ hep-thgr-qchep-phPRL(2018)·371 citations
28. 28*

    Critical behavior of Dirac fermions from perturbative renormalization

    Bernhard Ihrig🇩🇪 · Luminita N. Mihaila🇩🇪 · Michael M. Scherer🇩🇪

    Gapless Dirac fermions appear as quasiparticle excitations in various condensed-matter systems. They feature quantum critical points with critical behavior in the 2+1 dimensional Gross-Neveu universality class. The precise determination of their critical exponents defines a prime benchmark for complementary theoretical approaches, such as lattice simulations, the renormalization group and the conformal bootstrap. Despite promising recent developments in each of these methods, however, no satisfactory consensus on the fermionic critical exponents has been achieved, so far. Here, we perform a comprehensive analysis of the Ising Gross-Neveu universality classes based on the recently achieved four-loop perturbative calculations. We combine the perturbative series in $4-ϵ$ spacetime dimensions with the one for the purely fermionic Gross-Neveu model in $2+ϵ$ dimensions by employing polynomial interpolation as well as two-sided Padé approximants. Further, we provide predictions for the critical exponents exploring various resummation techniques following the strategies developed for the three-dimensional scalar $O(n)$ universality classes. We give an exhaustive appraisal of the current situation of Gross-Neveu universality by comparison to other methods. For large enough number of spinor components $N\ge 8$ as well as for the case of emergent supersymmetry $N=1$, we find our renormalization group estimates to be in excellent agreement with the conformal bootstrap, building a strong case for the validity of these values. For intermediate $N$ as well as in comparison with recent Monte Carlo results, deviations are found and critically discussed.

    ↳ cond-mat.str-elhep-phPRB(2018)·87 citations
29. 29*

    Status of rare exclusive $B$ meson decays in 2018

    Johannes Albrecht🇩🇪 · Stefanie Reichert🇩🇪 · Danny van Dyk🇩🇪

    This review discusses the present experimental and theoretical status of rare flavour-changing neutral current $b$-quark decays at the begin of 2018. It includes a discussion of the experimental situation and details of the currently observed anomalies in measurements of flavour observables, including lepton flavour universality. Progress on the theory side, within and beyond the Standard Model theory is also discussed, together with potential New Physics interpretations of the present measurements.

    ↳ hep-exhep-phInt.J.Mod.Phys.A(2018)·15 citations
30. 30*

    The SL(K+3,C) Symmetry of the Bosonic String Scattering Amplitudes

    Sheng-Hong Lai🇹🇼 · Jen-Chi Lee🇹🇼 · Yi Yang🇹🇼

    We discover that the exact string scattering amplitudes (SSA) of three tachyons and one arbitrary string state, or the Lauricella SSA (LSSA), in the 26D open bosonic string theory can be expressed in terms of the basis functions in the infinite dimensional representation space of the SL(K+3,C) group. In addition, we find that the K+2 recurrence relations among the LSSA discovered by the present authors previously can be used to reproduce the Cartan subalgebra and simple root system of the SL(K+3,C) group with rank K+2. As a result, the SL(K+3,C) group can be used to solve all the LSSA and express them in terms of one amplitude. As an application in the hard scattering limit, the SL(K+3,C) group can be used to directly prove Gross conjecture [1-3], which was previously corrected and proved by the method of decoupling of zero norm states [4-10].

    ↳ hep-thhep-phNPB(2019)·10 citations
31. 31*

    First results from a hidden photon dark matter search in the meV sector using a plane-parabolic mirror system

    Stefan Knirck🇩🇪 · Takayuki Yamazaki🇯🇵 · Yoshiki Okesaku🇯🇵 · Shoji Asai🇯🇵 · Toshitaka Idehara🇯🇵 · Toshiaki Inada🇯🇵

    We report on the first results from a new dish antenna search for hidden photon dark matter (HPDM) in the meV mass region. A double mirror system composed of a plane and a parabolic mirror is designed to convert HPDMs into photons focused on a receiver. In this phase 1 experiment we obtain an upper limit on the photon-HP kinetic mixing $\chi \lesssim 10^{-8}$ for the mass range of $0.67-0.92\mathrm{meV}$ using conventional mm-wave technology with a room-temperature receiver and a small-sized mirror system.

    ↳ hep-exhep-phphysics.ins-detJCAP(2018)·43 citations
32. 32*

    Laplacian spectrum on a nilmanifold, truncations and effective theories

    David Andriot🇨🇭 · Dimitrios Tsimpis🇫🇷

    Motivated by low energy effective theories arising from compactification on curved manifolds, we determine the complete spectrum of the Laplacian operator on the three-dimensional Heisenberg nilmanifold. We first use the result to construct a finite set of forms leading to an N=2 gauged supergravity, upon reduction on manifolds with SU(3) structure. Secondly, we show that in a certain geometrical limit the spectrum is truncated to the light modes, which turn out to be left-invariant forms of the nilmanifold. We also study the behavior of the towers of modes at different points in field space, in connection with the refined swampland distance conjecture.

    ↳ hep-thhep-phmath.SPJHEP(2018)·41 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.