Mon·Sep 9, 2019Monday·September 9, 2019

1. 01*

   The 28 GeV Dimuon Excess in Lepton Specific 2HDM

   Ali Cici🇹🇷 · Shaaban Khalil🇪🇬 · Busra Nis🇹🇷 · Cem Salih Un🇹🇷

   We explore the Higgs mass spectrum in a class of Two Higgs Doublet Models (THDMs) in which a scalar SU(2)_L doublet interacts only with quarks, while the second one interacts only with leptons. The spectrum includes two CP-even Higgs bosons, either of which can account for the SM-like Higgs boson, and the spectra involving light Higgs bosons receive strong impacts from the LEP results and the current collider analyses. We find that a consistent spectrum can involve a CP-odd Higgs boson as light as about 10 GeV, while the lightest CP-even Higgs boson cannot be lighter than about 55 GeV when m_A ~ 28 GeV. These analyses can rather bound the low tan beta region which can also accommodate an observed excess in dimuon events at m_mumu ~ 28 GeV. A lepton-specific class of THDMs (LS-THDM) can predict such an excess through A -> mu mu decays, while the solutions can be constrained by the A -> tau tau mode. After constraining the solutions with the consistent ranges of sigma(pp -> bbA -> bb tau tau), a largest excess at about 1.5 sigma at 8 TeV center of mass (COM) energy and 2 sigma at 13 TeV COM is observed for tan beta ~ 12 and m_A ~ 28 GeV in the sigma(pp -> bbA -> bb mu mu) events.

   hep-phNPB(2022)·8 citations
2. 02*

   Soft-gluon corrections for single top quark production in association with electroweak bosons

   Matthew Forslund🇺🇸 · Nikolaos Kidonakis🇺🇸

   We present results for higher-order soft-gluon radiative corrections for single top-quark production in association with electroweak bosons, including $t\gamma$ and $tZ$ production via anomalous FCNC couplings. We provide results for the total cross sections and differential distributions at LHC energies. We use $K$-factors to show the significance of the corrections compared to leading order, and we discuss uncertainties and the importance of the results.

   hep-ph3 citations
3. 03*

   Coupled $K^{+}\Lambda$ and $K^0\Lambda$ photoproduction off the nucleon: Consequences from the recent CLAS and MAMI data and the $N(1680)P_{11}$ narrow state

   T. Mart🇮🇩

   The new $\gamma n\to K^0\Lambda$ data obtained from the CLAS and MAMI collaborations are analyzed by employing an effective Lagrangian method. The constructed model can describe all available experimental data in both $\gamma p\to K^{+}\Lambda$ and $\gamma n\to K^0\Lambda$ channels, simultaneously. The background part of the model is built from the appropriate intermediate states involving the nucleon, kaon, and hyperon exchanges, whereas the resonance part is constructed from the consistent interaction Lagrangians and propagators. To check the performance of the model a detailed comparison between the calculated observables and experimental data in both isospin channels is presented, from which a nice agreement can be observed. The discrepancy between the CLAS and MAMI data in the $\gamma n\to K^0\Lambda$ channel is analyzed by utilizing three different models; M1, M2, and M3 that fit the CLAS, MAMI, and both CLAS and MAMI data sets, respectively. The effect of this discrepancy is studied by investigating the significance of individual nucleon resonances and the predicted beam-target helicity asymmetry $E$ that has been measured by the CLAS collaboration recently. It is found that the $N(1720)P_{13}$, $N(1900)P_{13}$, and $N(2060)D_{15}$ resonances are significant for improving the agreement between model calculation and data. This result is relatively stable to the choice of the model. The helicity asymmetry $E$ can be better explained by the models M1 and M3. Finally, the effect of the $N(1680)P_{11}$ narrow resonance on the cross section of both isospin channels is explored. It is found that the effect is more sensitive in the $\gamma n\to K^0\Lambda$ channel. In this case the model M3, that fits both CLAS and MAMI data, yields a more realistic effect.

   hep-phnucl-thPRD(2019)·20 citations
4. 04*

   Neutrino oscillations in gravitational and cosmological backgrounds

   George Koutsoumbas🇬🇷 · Dimitrios Metaxas🇬🇷

   We use the eikonal approximation in order to calculate the additional phase shift between two neutrino mass eigenstates during their propagation in a background of gravitational wave or scalar perturbations in the flat and the FRW spacetime metric. We comment on the dependence of the results on the characteristics of the perturbations, give some order-of-magnitude estimates, and find that, although small, the resulting phase difference persists for large redshifts, up to the validity of our approximations.

   hep-phastro-ph.COgr-qcGen.Rel.Grav.(2020)·27 citations
5. 05*

   Second-order QCD corrections to event shape distributions in deep inelastic scattering

   T. Gehrmann🇨🇭 · A. Huss🇨🇭 · J. Mo🇨🇭 · J. Niehues🇬🇧

   We compute the next-to-next-to-leading order (NNLO) QCD corrections to event shape distributions and their mean values in deep inelastic lepton-nucleon scattering. The magnitude and shape of the corrections varies considerably between different variables. The corrections reduce the renormalization and factorization scale uncertainty of the predictions. Using a dispersive model to describe non-perturbative power corrections, we compare the NNLO QCD predictions with data from the H1 and ZEUS experiments. The newly derived corrections improve the theory description of the distributions and of their mean values.

   hep-phEPJC(2019)·21 citations
6. 06*

   Study of QCD dynamics using small systems

   Suman Deb🇮🇳 · Golam Sarwar🇮🇳 · Raghunath Sahoo🇮🇳 · Jan-e Alam🇮🇳

   The multiplicity, finite system size and collision energy dependencies of heat capacity ($C_V$), conformal symmetry breaking measure (CSBM) and speed of sound ($c_s$) have been investigated using ALICE data for $p+p$ collisions at $\sqrt{s}$ = 7 TeV. The aim of this study is to ascertain the possibility of formation of a thermalized medium in such collisions. We find that there is a threshold in charged particle multiplicity beyond which $C_V$, CSBM and $c_s$ attain plateau. The presence of such threshold in multiplicity is further reflected in the variation of these quantities with center-of-mass energy ($\sqrt{s_{NN}}$). In order to have a grasp on experimentally obtained results, variation of $⟨p_T⟩$ with multiplicity has also been studied. The experimental results have been contrasted with PYTHIA8 and it is found that PYTHIA8 is inadequate to explain the features reflected in these quantities, thereby indicating the possibility of thermalization in such small system. It is also observed that the finite size effects alone cannot explain the non-extensive nature of particle spectra in $p+p$ collisions.

   hep-phnucl-exnucl-thEPJA(2021)·16 citations
7. 07*

   A global fit to $b\to c\tau \bar{\nu }$ anomalies after Moriond 2019

   Suman Kumbhakar🇮🇳 · Ashutosh Kumar Alok🇮🇳 · Dinesh Kumar🇵🇱 · S. Uma Sankar🇮🇳

   At Moriond 2019, Belle collaboration announced their new measurements on $R_D$ and $R_{D^{\ast }}$ which are in agreement with their Standard Model (SM) predictions within $1.2\sigma$. After inclusion of these measurements, the discrepancy between the world averages and the SM predictions of $R_D$-$R_{D^{\ast }}$ comes down from $4.1\sigma$ to $3.1\sigma$. Here we do a global fit by taking all measurements in $b\to c\tau \bar{\nu }$ transition. We find that there are seven allowed new physics solutions, each with different Lorentz structure. Further we show that it is possible to distinguish between them by means of the five observables: the $\tau$ polarization fraction in the decay $B\to D\tau \bar{\nu }$, the precision measurement of $R_D$, the forward-backward asymmetries in the decays $B\to (D,D^{\ast })\tau \bar{\nu }$ and the branching ratio of $B_c\to \tau \bar{\nu }$.

   hep-phPoS(2020)·24 citations
8. 08*

   A $U(1{)}_X$ extension to the MSSM with three families

   J.S. Alvarado🇨🇴 · Carlos E. Diaz🇨🇴 · R. Martinez🇨🇴

   We propose a supersymmetric extension of the anomaly-free and three families nonuniversal $U(1)$ model, with the inclusion of four Higgs doublets and four Higgs singlets. The quark sector is extended by adding three exotic quark singlets, while the lepton sector includes two exotic charged lepton singlets, three right-handed neutrinos and three sterile Majorana neutrinos to obtain the fermionic mass spectrum. By implementing an additional ${\mathbb{Z}}_2$ symmetry, the Yukawa coupling terms are suited in such a way that the fermion mass hierarchy is obtained without fine-tuning. The effective mass matrix for SM neutrinos is fitted to current neutrino oscillation data to check the consistency of the model with experimental evidence, obtaining that the normal-ordering scheme is preferred over the inverse ones. The electron and up, down and strange quarks are massless at tree level, but they get masses through radiative correction at one loop level coming from the sleptons and Higgsinos contributions. We show that the model predicts a like-Higgs SM mass at electroweak scale by using the VEV according to the symmetry breaking and fermion masses.

   hep-ph1 citation
9. 09*

   Collinear Factorization in Wide-Angle Hadron Pair Production in $e^{+}{e}^{-}$ Annihilation

   E. Moffat🇺🇸 · T. C. Rogers🇺🇸 · N. Sato🇺🇸 · A. Signori🇺🇸

   We compute the inclusive unpolarized dihadron production cross section in the far from back-to-back region of $e^{+}{e}^{-}$ annihilation in leading order pQCD using existing fragmentation function fits and standard collinear factorization, focusing on the large transverse momentum region where transverse momentum is comparable to the hard scale (the center-of-mass energy). We compare with standard transverse-momentum-dependent (TMD) fragmentation function-based predictions intended for the small transverse momentum region with the aim of testing the expectation that the two types of calculation roughly coincide at intermediate transverse momentum. We find significant tension, within the intermediate transverse momentum region, between calculations done with existing non-perturbative TMD fragmentation functions and collinear factorization calculations if the center-of-mass energy is not extremely large. We argue that $e^{+}{e}^{-}$ measurements are ideal for resolving this tension and exploring the large-to-small transverse momentum transition, given the typically larger hard scales ($\gtrsim 10$ GeV) of the process as compared with similar scenarios that arise in semi-inclusive deep inelastic scattering and fixed-target Drell-Yan measurements.

   hep-phnucl-thPRD(2019)·16 citations
10. 10*

    Gravitational wave and collider signals in complex two-Higgs doublet model with dynamical CP-violation at finite temperature

    Xiao Wang🇨🇳 · Fa Peng Huang🇺🇸 · Xinmin Zhang🇨🇳

    Extra CP-violating source for electroweak baryogenesis can dynamically appear at finite temperature in the complex two-Higgs doublet model, which might help to alleviate the strong constraints from the electric dipole moment experiments. In this scenario, we study the detailed phase transition dynamics and the corresponding gravitational wave signals in synergy with the collider signals at future lepton colliders. For some parameter spaces, various phase transition patterns can occur, such as the multi-step phase transition and supercooling. Gravitational waves complementary to collider signals can help to pin down the underlying phase transition dynamics or different phase transition patterns.

    hep-phastro-ph.COPRD(2020)·66 citations
11. 11*

    The QCD phase structure at finite temperature and density

    Wei-jie Fu🇨🇳 · Jan M. Pawlowski🇩🇪 · Fabian Rennecke🇺🇸

    We discuss the phase structure of QCD for $N_f=2$ and $N_f=2+1$ dynamical quark flavours at finite temperature and baryon chemical potential. It emerges dynamically from the underlying fundamental interactions between quarks and gluons in our work. To this end, starting from the perturbative high-energy regime, we systematically integrate-out quantum fluctuations towards low energies by using the functional renormalisation group. By dynamically hadronising the dominant interaction channels responsible for the formation of light mesons and quark condensates, we are able to extract the phase diagram for ${\mu }_B/T\lesssim 6$. We find a critical endpoint at $(T_{\text{CEP}},{{\mu }_B}_{\text{CEP}})=(107,635)\text{MeV}$. The curvature of the phase boundary at small chemical potential is $\kappa =0.0142(2)$, computed from the renormalised light chiral condensate ${\Delta }_{l,R}$. Furthermore, we find indications for an inhomogeneous regime in the vicinity and above the chiral transition for ${\mu }_B\gtrsim 417$ MeV. Where applicable, our results are in very good agreement with the most recent lattice results. We also compare to results from other functional methods and phenomenological freeze-out data. This indicates that a consistent picture of the phase structure at finite baryon chemical potential is beginning to emerge. The systematic uncertainty of our results grows large in the density regime around the critical endpoint and we discuss necessary improvements of our current approximation towards a quantitatively precise determination of QCD phase diagram.

    hep-phPRD(2020)·491 citations
12. 12*

    Nakanishi integral representation for the quark-photon vertex

    Vladimir Sauli🇨🇿

    Using a nonperturbative framework of Dyson-Schwinger equations a class of Nakanishi's like integral representations for the transverse part of the quark-photon vertex is derived. For this but also for its own purpose the two and single variable integral representations for untruncated quark-antiquark-photon vertex is proposed as well. To exhibit the adequacy of proposed representation, the Dyson-Schwinger equation for the vertex is transformed into the equivalent set of coupled integro-differential equations for Nakanishi weight functions: functions that appear linearly in the numerator of given integral representation. Their knowledge then provide self-consistent nonperturbative solution for the vertex in the entire Minkowski space.

    hep-phnucl-th2 citations
13. 13*

    Improved Bethe-Heitler formula

    Wei Zhu🇨🇳

    The Bethe-Heitler formula describes bremsstrahlung and it's a typical and important example in quantum electromagnetic dynamics (QED). This formula is widely applied in many branches of physics and astrophysics. We find that the integrated bremsstrahlung cross section at the static approximation and high energy limit has an unexpected big increment, which is missed by previous bremsstrahlung theory. This anomalous effect also exists in electron-positron pair creation. We derive the relating formulas and point out that electromagnetic cascades at the top of atmosphere can test this effect.

    hep-phastro-ph.HENPB(2020)·6 citations
14. 14*

    Revisiting CP violation in $D\to PP$ and $VP$ decays

    Hai-Yang Cheng🇹🇼 · Cheng-Wei Chiang🇹🇼

    Direct CP violation in the hadronic charm decays provides a good testing ground for the Kobayashi-Maskawa mechanism in the Standard Model. Any significant deviations from the expectation would be indirect evidence of physics beyond the Standard Model. In view of improved measurements from LHCb and BESIII experiments, we re-analyze the Cabibbo-favored $D\to PP$ and $VP$ decays in the topological diagram approach. By assuming certain SU(3)-breaking effects in the tree-type amplitudes, we make predictions for both branching fractions and CP asymmetries of the singly Cabibbo-suppressed decay modes. While the color-allowed and -suppressed amplitudes are preferred to scale by the factor dictated by factorization in the $PP$ modes, no such scaling is required in the $VP$ modes. The $W$-exchange amplitudes are found to change by 10\% to 50\% and depend on whether $d\overline{d}$ or $s\overline{s}$ pair directly emerges from $W$-exchange. The predictions of branching fractions are generally improved after these SU(3) symmetry breaking effects are taken into account. We show in detail how the tree-type, QCD-penguin, and weak penguin-annihilation diagrams contribute and modify CP asymmetry predictions. Future measurements of sufficiently many direct CP asymmetries will be very useful in removing a discrete ambiguity in the strong phases as well as discriminating among different theory approaches. In particular, we predict $a_{CP}(K^{+}{K}^{-})-a_{CP}({\pi }^{+}{\pi }^{-})=(-1.14\pm 0.26)\times 10^{-3}$ or $(-1.25\pm 0.25)\times 10^{-3}$, consistent with the latest data, and $a_{CP}(K^{+}{K}^{\ast -})-a_{CP}({\pi }^{+}{\rho }^{-})=(-1.52\pm 0.43)\times 10^{-3}$, an attractive and measurable observable in the near future. Moreover, we observe that such CP asymmetry differences are dominated by long-distance penguin-exchange through final-state rescattering.

    hep-phhep-exPRD(2019)·135 citations
15. 15*

    High-energy resummation in heavy-quark pair hadroproduction

    Andrèe Dafne Bolognino🇮🇹 · Francesco Giovanni Celiberto🇮🇹 · Michael Fucilla🇮🇹 · Dmitry Yu. Ivanov🇷🇺 · Alessandro Papa🇮🇹

    The inclusive hadroproduction of two heavy quarks, featuring a large separation in rapidity, is proposed as a novel probe channel of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) approach. In a theoretical setup which includes full resummation of leading logarithms in the center-of-mass energy and partial resummation of the next-to-leading ones, predictions for the cross section and azimuthal coefficients are presented for kinematic configurations typical of current and possible future experimental analyses at the LHC.

    hep-phEPJC(2019)·80 citations
16. 16*

    PASSAT: Particle Accelerator helioScopes for Slim Axion-like-particle deTection

    Walter M. Bonivento🇮🇹 · Doojin Kim🇺🇸 · Kuver Sinha🇺🇸

    We propose a novel method to search for axion-like particles (ALPs) at particle accelerator experiments (exps). ALPs produced at the target via the Primakoff effect subsequently enter a region with a magnetic field, where they are converted to photons that are then detected. Dubbed Particle Accelerator helioScopes for Slim Axion-like-particle deTection (PASSAT), our proposal uses the principle of the axion helioscope but replaces ALPs produced in Sun with those produced in a target material. Since we rely on ALP-photon conversions, our proposal probes light (slim) ALPs that are otherwise inaccessible to lab-based exps which rely on ALP decay, and complements astrophysical probes that are more model-dependent. We first reinterpret existing data from the NOMAD exp in light of PASSAT, and constrain the parameter space for ALPs lighter than ~100 eV and ALP-photon coupling larger than ~$10^{-4}$ GeV${}^{-1}$. As benchmarks of feasible low-cost exps improving over the NOMAD limits, we study the possibility of reusing the magnets of the CAST and the proposed BabyIAXO exps and placing them at the proposed BDF facility at CERN, along with some new detectors. We find that these realizations of PASSAT allow for a direct probe of the parameter space for ALPs lighter than ~100 eV and ALP-photon coupling larger than ~4 x $10^{-6}$ GeV${}^{-1}$, which are regions that have not been probed yet by exps with lab-produced ALPs. In contrast to other proposals aiming at detecting 1 or 2-photon only events in hadronic beam dump environments, that rely heavily on Monte Carlo simulations, the background (BG) in our proposal can be directly measured in-situ, its suppression optimized, and the irreducible BG statistically subtracted. Sensitivity studies with other beams will be the subject of future work. The measurements suggested here represent an additional physics case for the BDF beyond those already proposed.

    hep-phhep-exEPJC(2020)·18 citations
17. 17*

    Production of $X(3872)$ and a Photon in $e^{+}{e}^{-}$ Annihilation

    Eric Braaten🇺🇸 · Li-Ping He🇺🇸 · Kevin Ingles🇺🇸

    If the $X(3872)$ is a weakly bound charm-meson molecule, it can be produced in $e^{+}{e}^{-}$ annihilation by the creation of $D^{\ast 0}{\bar{D}}^{\ast 0}$ from a virtual photon followed by the rescattering of the P-wave charm-meson pair into the $X$ and a photon. A triangle singularity produces a narrow peak in the cross section for $e^{+}{e}^{-}\to X\gamma$ 2.2 MeV above the $D^{\ast 0}{\bar{D}}^{\ast 0}$ threshold. We predict the normalized cross section in the region of the peak. We show that the absorptive contribution to the cross section for $e^{+}{e}^{-}\to D^{\ast 0}{\bar{D}}^{\ast 0}\to X\gamma$, which was calculated previously by Dubynskiy and Voloshin, does not give a good approximation to the peak from the triangle singularity.

    hep-phPRD(2020)·17 citations
18. 18*

    Slavnov-Taylor Identities in Spontaneously Broken Non-Abelian Effective Gauge Theories

    Andrea Quadri🇮🇹

    We study the solution to the Slavnov-Taylor (ST) identities in spontaneously broken effective gauge theories for a non-Abelian gauge group. The procedure to extract the $\beta$-functions of the theory in the presence of (generalized) non-polynomial field redefinitions is elucidated.

    ↳ hep-thhep-phProc.Steklov Inst.Math.(2020)·1 citation
19. 19*

    Fate of scalar dark matter solitons around supermassive galactic black holes

    Philippe Brax🇫🇷 · Jose A. R. Cembranos🇪🇸 · Patrick Valageas🇫🇷

    In scalar-field dark matter scenarios, a scalar-field soliton could form at the center of galactic halos, around the supermassive black holes that sit at the center of galaxies. Focusing on the large scalar-mass limit, where the soliton is formed by the balance between self-gravity and a repulsive self-interaction, we study the infall of the scalar field onto the central Schwarzschild black hole. We derive the scalar-field profile, from the Schwarzschild radius to the large radii dominated by the scalar cloud. We show that the steady state solution selects the maximum allowed flux, with a critical profile that is similar to the transonic solution obtained for the hydrodynamic case. This finite flux, which scales as the inverse of the self-interaction coupling, is small enough to allow the dark matter soliton to survive for many Hubble times.

    ↳ astro-ph.COhep-phPRD(2020)·50 citations
20. 20*

    Vacuum energy in the effective field theory of general relativity II: Inclusion of fermions and a comment on the QCD contribution

    J. Gegelia🇩🇪 · Ulf-G. Meißner🇩🇪

    Recently in the framework of a two-loop order calculation for an effective field theory of scalar and vector fields interacting with the metric field we have shown that for the cosmological constant term which is fixed by the condition of vanishing vacuum energy the graviton remains massless and there exists a self-consistent effective field theory of general relativity defined on a flat Minkowski background. In the current paper we extend the two-loop analysis for an effective field theory of fermions interacting with the gravitational field and obtain an analogous result. We also address the issues of fine tuning of the strong interaction contribution to the vacuum energy and the compatibility of chiral symmetry in the light quark sector with the consistency of the effective field theory of general relativity in a flat Minkowski background.

    ↳ hep-thgr-qchep-phnucl-thPRD(2019)·3 citations
21. 21*

    $I=3$ three-pion scattering amplitude from lattice QCD

    Tyler D. Blanton🇺🇸 · Fernando Romero-López🇪🇸 · Stephen R. Sharpe🇺🇸

    We analyze the spectrum of two- and three-pion states of maximal isospin obtained recently for isosymmetric QCD with pion mass $M\approx 200$MeV in Ref. [1]. Using the relativistic three-particle quantization condition, we find $\sim 2\sigma$ evidence for a nonzero value for the contact part of the three-${\pi }^{+}$ ($I=3$) scattering amplitude. We also compare our results to leading-order chiral perturbation theory. We find good agreement at threshold, and some tension in the energy dependent part of the three-${\pi }^{+}$scattering amplitude. We also find that the two-${\pi }^{+}$ ($I=2$) spectrum is fit well by an $s$-wave phase shift that incorporates the expected Adler zero.

    ↳ hep-lathep-exhep-phnucl-thPRL(2020)·126 citations
22. 22*

    Quantum corrections for D-brane models with broken supersymmetry

    Wilfried Buchmuller🇩🇪 · Emilian Dudas🇫🇷 · Yoshiyuki Tatsuta🇩🇪

    Intersecting D-brane models and their T-dual magnetic compactifications yield attractive models of particle physics where magnetic flux plays a twofold role, being the source of fermion chirality as well as supersymmetry breaking. A potential problem of these models is the appearance of tachyons which can only be avoided in certain regions of moduli space and in the presence of Wilson lines. We study the effective four-dimensional field theory for an orientifold compactification of type IIA string theory and the corresponding toroidal compactification of type I string theory. After determining the Kaluza-Klein and Landau-level towers of massive states in different sectors of the model, we evaluate their contributions to the one-loop effective potential, summing over all massive states, and we relate the result to the corresponding string partition functions. We find that the Wilson-line effective potential has only saddle points, and the theory is therefore driven to the tachyonic regime. There tachyon condensation takes place and chiral fermions acquire a mass of the order of the compactification scale. We also find evidence for a tachyonic behaviour of the volume moduli. More work on tachyon condensation is needed to clarify the connection between supersymmetry breaking, a chiral fermion spectrum and vacuum stability.

    ↳ hep-thhep-phJHEP(2019)·8 citations
23. 23*

    Catalytic Creation of Baby Bubble Universe with Small Positive Cosmological Constant

    Issei Koga🇯🇵 · Yutaka Ookouchi🇯🇵

    We investigate the decay of metastable de Sitter, Minkowski and anti-de Sitter vacua catalyzed by a black hole and a cloud of strings. We apply the method to the creation of the four dimensional bubble universe in the five dimensional anti-de Sitter spacetime recently proposed by Banerjee, Danielsson, Dibitetto, Giri and Schillo. We study the bounce action for the creation and find that the bubble with very small cosmological constant, of order ${\Lambda }^{(4)}/M_4^2\sim 10^{-120}$, is favored by the catalysis by assuming appropriate mass scales of the black hole and the cloud of strings to reproduce the present energy densities of matter and radiation in the bubble universe.

    ↳ hep-thgr-qchep-phJHEP(2019)·13 citations
24. 24*

    Waveform of gravitational waves in the ghost-free parity-violating gravities

    Jin Qiao🇨🇳 · Tao Zhu🇨🇳 · Wen Zhao🇨🇳 · Anzhong Wang🇺🇸

    Gravitational waves (GWs) provide an excellent opportunity to test the gravity in the strong gravitational fields. In this article, we calculate the waveform of GWs, produced by the coalescence of compact binaries, in an extension of the Chern-Simons gravity by including higher derivatives of the coupling scalar field. By comparing the two circular polarization modes, we find the effects of amplitude birefringence and velocity birefringence of GWs in their propagation caused by the parity violation in gravity, which are explicitly presented in the GW waveforms by the amplitude and phase modifications respectively. Combining the two modes, we obtain the GW waveforms in the Fourier domain, and find that the deviations from those in General Relativity are dominated by effects of velocity birefringence of GWs. In addition, we also map the effects of the parity violation on the waveform onto the parameterized post-Einsteinian (PPE) framework and identify explicitly the PPE parameters.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2019)·63 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.