Fri·Jul 16, 2021Friday·July 16, 2021

1. 01*

   Quantum coherence of photons at cosmological distances

   Arjun Berera🇬🇧 · Suddhasattwa Brahma🇨🇦 · Robert Brandenberger🇨🇦 · Jaime Calderón-Figueroa🇬🇧 · Alan Heavens🇬🇧

   We identify potential sources of decoherence for $U(1)$ gauge bosons from a cosmological standpoint. Besides interactions with different species in the cosmological medium, we also consider effects due to the expansion of the Universe, which can produce particles (especially scalars) than can potentially interact with the photon in a quantum state. We look in particular at the case of axion-like particles and their predicted decay channels in our analysis. These interactions are shown to have a negligible effect as far as decoherence goes. Interaction rates with CMB radiation or through Thomson scattering are small, so that the interstellar medium remains the biggest decoherence factor. Thus, quantum teleportation experiments with photon energies in the range $1$-$10$ keV should be feasible at cosmological distances up to the galaxy formation epoch or beyond ($z\sim 100$).

   hep-phastro-ph.COPRD(2021)·13 citations
2. 02*

   Floquet vacuum engineering: Laser-driven chiral soliton lattice in the QCD vacuum

   Akihiro Yamada🇯🇵 · Naoki Yamamoto🇯🇵

   What happens to the QCD vacuum when a time-periodic circularly polarized laser field with a sufficiently large intensity and frequency is applied? Based on the Floquet formalism for periodically driven systems and the systematic low-energy effective theory of QCD, we show that for a sufficiently large frequency and above a critical intensity, the QCD vacuum is unstable against the chiral soliton lattice of pions; a crystalline structure of topological solitons that spontaneously breaks parity and continuous translational symmetries. Our work would pave the way for novel "Floquet vacuum engineering."

   hep-phcond-mat.str-elhep-thPRD(2021)·15 citations
3. 03*

   Efficient numerical integration of thermal interaction rates

   G. Jackson🇺🇸 · M. Laine🇨🇭

   In many problems in particle cosmology, interaction rates are dominated by $2\leftrightarrow 2$ scatterings, or get a substantial contribution from them, given that $1\leftrightarrow 2$ and $1\leftrightarrow 3$ reactions are phase-space suppressed. We describe an algorithm to represent, regularize, and evaluate a class of thermal $2\leftrightarrow 2$ and $1\leftrightarrow 3$ interaction rates for general momenta, masses, chemical potentials, and helicity projections. A key ingredient is an automated inclusion of virtual corrections to $1\leftrightarrow 2$ scatterings, which eliminate logarithmic and double-logarithmic IR divergences from the real $2\leftrightarrow 2$ and $1\leftrightarrow 3$ processes. We also review thermal and chemical potential induced contributions that require resummation if plasma particles are ultrarelativistic.

   hep-phJHEP(2021)·12 citations
4. 04*

   Using Covariant Polarisation Sums in QCD

   M. Kachelriess🇳🇴 · M.N. Malmquist🇳🇴

   Covariant gauges lead to spurious, non-physical polarisation states of gauge bosons. In QED, the use of the Feynman gauge, ${\sum }_{\lambda }{ϵ}_{\mu }^{(\lambda )}{ϵ}_{\nu }^{(\lambda )\ast }=-{\eta }_{\mu \nu }$, is justified by the Ward identity which ensures that the contributions of non-physical polarisation states cancel in physical observables. In contrast, the same replacement can be applied only to a single external gauge boson in squared amplitudes of non-abelian gauge theories like QCD. In general, the use of this replacement requires to include external Faddeev-Popov ghosts. We present a pedagogical derivation of these ghost contributions applying the optical theorem and the Cutkosky cutting rules. We find that the resulting cross terms $A(c_1,{\bar{c}}_1;\dots )A({\bar{c}}_1,c_1;\dots {)}^{\ast }$ between ghost amplitudes cannot be transformed into $(-1{)}^{n/2}|A(c_1,{\bar{c}}_1;\dots ){|}^2$ in the case of more than two ghosts. Thus the Feynman rule stated in the literature holds only for two external ghosts, while it is in general incorrect.

   hep-phEur.Phys.J.Plus(2022)·3 citations
5. 05*

   Theoretical analysis of the leptonic decays $B\to \ell \ell {\ell }^{\prime }{\bar{\nu }}_{{\ell }^{\prime }}$

   Mikhail A. Ivanov🇷🇺 · Dmitri Melikhov🇷🇺

   We discuss the amplitude of the $B\to l^{+}{l}^{-}{l}^{\prime }{\nu }^{\prime }$ decays and the differential decay rate $d^2\Gamma /d{q}^{2}d{q}^{\prime 2}$, $q$ the momentum of the $l^{+}{l}^{-}$ pair emitted from the electromagnetic vertex and $q^{\prime }$ the momentum of the $l^{\prime }{\nu }^{\prime }$ pair emitted from the weak vertex. For the relevant form factors, we construct dispersion representations in $q^2$ which consistently take into account the Ward identity constraints at $q^2=0$ and the contributions of light vector resonances. This allows a reliable description of the form factors in the range $0<q^2\le 1$ GeV${}^2$ that saturates around 99% of the decay rate. The differential decay rate behaves at small $q^2$ as $d\Gamma (B\to l^{+}{l}^{-}{l}^{\prime }{\nu }^{\prime })/d{q}^2\propto 1/q^2$ in the limit $m_l^{\prime }=0$, but contains also more singlular contribution of order $m_l^{\prime 2}/q^4$, which we take into account. For the case $m_l^{\prime }\le m_l$, the latter may be neglected and one obtains a mild logarithmic dependence of $\Gamma (B\to l^{+}{l}^{-}{l}^{\prime }{\nu }^{\prime })$ on $m_l$. For the case $m_l\ll m_l^{\prime }$, however, the $m_l^{\prime 2}/q^4$ terms dominate the decay rate leading to $\Gamma (B\to l^{+}{l}^{-}{l}^{\prime }{\nu }^{\prime })\sim m_l^{\prime 2}/m_l^2$. We find the following features of the four-lepton $B$-decays: (i) The decay rates $\Gamma \left(B\to {\mu }^{+}{\mu }^{-}(\mu {\nu }_{\mu },e{\nu }_e)\right)$ are fully dominated by the region of light vector resonances $q^2\simeq M_{\rho }^2,M_{\omega }^2$; (ii) The decay rate $\Gamma (B\to e^{+}{e}^{-}e{\nu }_e)$ receives comparable contributions from the region near $q^2\sim 4m_e^2$ and from the resonance region; (iii) One finds a strong enhancement of the decay rate $\Gamma (B\to e^{+}{e}^{-}\mu {\nu }_{\mu })\sim m_{\mu }^2/m_e^2$ which is dominated by the region $q^2\sim 4m_e^2$ due to the terms $O(m_{\mu }^2/q^4)$ in the differential distribution.

   hep-phPRD(2022)·16 citations
6. 06*

   London model of dual color superconductor

   Jiri Hosek🇨🇿

   Following closely the logic of the London phenomenological macroscopic theory of the Meissner effect in superconductors we describe the origin of the short-range behavior of the chromo-electric field, the necessary ingredient for color confinement in QCD. The genuinely non-Abelian model is specified by the strong-coupling colored-gluon current. Its first term, as the superconductivity current, is proportional to the gauge potential. The new term is simply related to the chromo-magnetic pseudo-vector current of the non-Abelian Bianchi identity. We suggest that this London dual color superconductivity current is responsible for the observed almost perfect fluidity in droplets of the strongly interacting quark-gluon plasma. Its chromo-magnetic component should have a specific experimental manifestation.

   hep-phhep-thEPJ Web Conf.(2022)·0 citations
7. 07*

   Lepton and quark mixing patterns with generalized CP transformations

   Joy Ganguly🇮🇳 · Raghavendra Srikanth Hundi🇮🇳

   In this work, we have modified a scenario, originally proposed by Grimus and Lavoura, in order to obtain maximal values for atmospheric mixing angle and CP violating Dirac phase of the lepton sector. To achieve this, we have employed CP and some discrete symmetries in a type II seesaw model. In order to make predictions about neutrino mass ordering and the smallness of the reactor angle, we have obtained some conditions on the elements of the neutrino mass matrix of our model. Finally, within the framework of our model, we have studied quark masses and mixing pattern.

   hep-phCPC(2022)·6 citations
8. 08*

   $c\to u\nu \bar{\nu }$ transitions of $B_c$ mesons: 331 model facing Standard Model null tests

   Pietro Colangelo🇮🇹 · Fulvia De Fazio🇮🇹 · Francesco Loparco🇮🇹

   The Glashow-Iliopoulos-Maiani mechanism is extremely efficient to suppress the flavour-changing neutral current decays of charmed hadrons induced by the $c\to u$ transitions, making such processes particularly sensitive to phenomena beyond the Standard Model. In particular, $c\to u$ decays with a neutrino pair in the final state are theoretically appealing due to the small long-distance contributions. Moreover, in the framework of the Standard Model Effective Field Theory (SMEFT), the $SU(2{)}_L$ invariance allows to relate the Wilson coefficients in the effective Hamiltonian governing the $c\to u\nu \bar{\nu }$ decays to the coefficients in the $c\to u{\ell }^{+}{\ell }^{-}$ Hamiltonian. We analyze the $B_c\to B^{(\ast )+}\nu \bar{\nu }$ decays, for which branching fractions of at most $\mathcal{O}(10^{-16})$ are predicted in the Standard Model including short- and long-distance contributions, so small that they can be considered as null tests. Using SMEFT and the relation to the $c\to u{\ell }^{+}{\ell }^{-}$ processes we study the largest enhancement achievable in generic new physics scenarios. Then we focus on a particular extension of the Standard Model, the 331 model. SMEFT relations and the connection with $c\to u{\ell }^{+}{\ell }^{-}$ imply that $\mathcal{B}(B_c\to B^{(\ast )+}\nu \bar{\nu })$ could even reach $\mathcal{O}(10^{-6})$, an extremely large enhancement. A less pronounced effect is found in the 331 model, with $\mathcal{O}(10^{-11})$ predicted branching fractions. Within the 331 model correlations exist among the $B_c\to B^{(\ast )+}\nu \bar{\nu }$ and $K\to \pi \nu \bar{\nu }$, $B\to (X_s,K,K^{\ast })\nu \bar{\nu }$ channels.

   hep-phhep-exhep-latPRD(2021)·22 citations
9. 09*

   Next-to-leading power two-loop soft functions for the Drell-Yan process at threshold

   Alessandro Broggio🇮🇹 · Sebastian Jaskiewicz🇬🇧 · Leonardo Vernazza🇮🇹

   We calculate the generalized soft functions at $\mathcal{O}({\alpha }_s^2)$ at next-to-leading power accuracy for the Drell-Yan process at threshold. The operator definitions of these objects contain explicit insertions of soft gauge and matter fields, giving rise to a dependence on additional convolution variables with respect to the leading power result. These soft functions constitute the last missing ingredient for the validation of the bare factorization theorem to NNLO accuracy. We carry out the calculations by reducing the soft squared amplitudes into a set of canonical master integrals and we employ the method of differential equations to evaluate them. We retain the exact $d$-dimensional dependence of the convolution variables at the integration boundaries in order to regulate the fixed-order convolution integrals. After combining our soft functions with the relevant collinear functions, we perform checks of the results at the cross-section level against the literature and expansion-by-regions calculations, at NNLO and partly at N${}^3$LO, finding agreement.

   hep-phJHEP(2021)·24 citations
10. 10*

    Photoproduction of diffractive dijets in Pythia 8

    Ilkka Helenius🇫🇮

    The new framework for the simulations of hard diffractive events in photoproduction within Pythia 8 is presented. The model, originally introduced for proton-proton collisions, applies the dynamical rapidity gap survival probability based on the multiparton interaction model in Pythia. These additional interactions provide a natural explanation for the observed factorization-breaking effects in hard diffraction by filling up the rapidity gaps used to classify the events of diffractive origin. The generated cross sections are well in line with the existing data from HERA experiments and predictions for the future electron-ion collider are presented. In addition, also predictions for ultra-peripheral collisions at the LHC have been calculated where the factorization-breaking effects are found to be more pronounced.

    hep-phSciPost Phys.Proc.(2022)·2 citations
11. 11*

    Axion-photon conversion in strongly magnetised plasmas

    Alexander J. Millar🇸🇪 · Sebastian Baum🇺🇸 · Matthew Lawson🇸🇪 · M.C. David Marsh🇸🇪

    Axion dark matter can resonantly convert to photons in the magnetosphere of neutron stars, possibly giving rise to radio signals observable on Earth. This method for the indirect detection of axion dark matter has recently received significant attention in the literature. The calculation of the radio signal is complicated by a number of effects; most importantly, the gravitational infall of the axions onto the neutron star accelerates them to semi-relativistic speed, and the neutron star magnetosphere is highly anisotropic. Both of these factors complicate the calculation of the conversion of axions to photons. In this work, we present the first fully three-dimensional calculation of the axion-photon conversion in highly magnetised anisotropic media. Depending on the axion trajectory, this calculation leads to orders-of-magnitude differences in the conversion compared to the simplified one-dimensional calculation used so far in the literature, altering the directionality of the produced photons. Our results will have important implications for the radio signal one would observe in a telescope.

    hep-phastro-ph.COJCAP(2021)·72 citations
12. 12*

    Vector-like quarks decaying into singly and doubly charged bosons at LHC

    Gennaro Corcella🇮🇹 · Antonio Costantini🇧🇪 · Margherita Ghezzi🇩🇪 · Luca Panizzi🇸🇪 · Giovanni Marco Pruna🇮🇪 · Jakub Šalko🇸🇪

    We investigate the production of vector-like quarks with charge $5/3$ at the LHC and their subsequent decays into new singly or doubly charged bosons plus a heavy quark (top or bottom). In particular, we explore final states with same-sign di-leptons (electron or muon pairs), with the leptons coming from the decay of the new bosons and, in the case of production of singly charged bosons, from top quarks as well. These processes are predicted by classes of models based on extensions of the gauge group of the Standard Model, such as the 331 Model, where the electroweak symmetry is described by $SU(3{)}_L\times U(1{)}_X$, $X$ being a new abelian charge. For this purpose, a CMS search for vector-like partners with charge 5/3 decaying into $Wt$ is recast to obtain model-independent bounds and projected reaches at future luminosity stages of the LHC. The results are then interpreted as mass bounds for the new particles predicted in the 331 Model and as a constrain on the scale of its spontaneous symmetry breaking. The complete set of model-independent results are provided as recast efficiencies, to allow for reinterpretation in different scenarios.

    hep-phhep-exJHEP(2021)·30 citations
13. 13*

    The $\pi f_0(500)$ decay of the $a_1(1260)$

    R. Molina🇪🇸 · M. Doering🇺🇸 · W. H. Liang🇨🇳 · E. Oset🇪🇸

    We evaluate the $a_1(1260)\to \pi \sigma (f_0(500))$ decay width from the perspective that the $a_1(1260)$ resonance is dynamically generated from the pseudoscalar-vector interaction and the $\sigma$ arises from the pseudoscalar-pseudoscalar interaction. A triangle mechanism with $a_1(1260)\to \rho \pi$ followed by $\rho \to \pi \pi$ and a fusion of two pions within the loop to produce the $\sigma$ provides the mechanism for this decay under these assumptions for the nature of the two resonances. We obtain widths of the order of $13-22$ MeV. Present experimental results differ substantially from each other, suggesting that extra efforts should be devoted to the precise extraction of this important partial decay width, which should provide valuable information on the nature of the axial vector and scalar meson resonances and help clarify the role of the $\pi \sigma$ channel in recent lattice QCD calculations of the $a_1$.

    hep-phnucl-thEPJC(2021)·11 citations
14. 14*

    Probing the profile of bulk matter in p+Pb collisions via directed flow of heavy quarks

    Md Rihan Haque🇵🇱 · Subhash Singha🇨🇳 · Bedangadas Mohanty🇮🇳

    The asymmetric initial geometry in p+Pb collisions provide an opportunity to probe the initial matter distribution in these collisions. Using A Multi-Phase Transport (AMPT) model, we have studied the production of light and heavy quark particles in p+Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV. The pseudo-rapidity density (dN/d$\eta$) and elliptic flow ($v_2$) of light-quark particles from AMPT reasonably agrees with the measurements by ALICE. We predicted the directed flow of light and heavy quarks in p+Pb collisions. The $v_1$ of both light and heavy-quark mesons show a non-trivial $p_T$ dependence in p- and Pb-going directions. When integrated over the transverse momentum range 0 $<p_T<$5 GeV/c, the magnitude of heavy quark directed flow ($v_1$) is found to be 15 times larger than the light quark species in the Pb-going direction while the same in the p-going direction are comparable. The light and heavy quarks $v_1$ may offer the possibility to probe the initial matter density as well as the collective dynamics in p+Pb collisions

    hep-phPRC(2021)·3 citations
15. 15*

    Consistent higher order $\sigma (\mathcal{G}\mathcal{G}\to h)$, $\Gamma (h\to \mathcal{G}\mathcal{G})$ and $\Gamma (h\to \gamma \gamma )$ in geoSMEFT

    Tyler Corbett🇩🇰 · Adam Martin🇺🇸 · Michael Trott🇩🇰

    We report consistent results for $\Gamma (h\to \gamma \gamma )$, $\sigma (\mathcal{G}\mathcal{G}\to h)$ and $\Gamma (h\to \mathcal{G}\mathcal{G})$ in the Standard Model Effective Field Theory (SMEFT) perturbing the SM by corrections $\mathcal{O}({\bar{v}}_T^2/16{\pi }^2{\Lambda }^2)$ in the Background Field Method (BFM) approach to gauge fixing, and to $\mathcal{O}({\bar{v}}_T^4/{\Lambda }^4)$ using the geometric formulation of the SMEFT. We combine and modify recent results in the literature into a complete set of consistent results, uniforming conventions, and simultaneously complete the one loop results for these processes in the BFM. We emphasise calculational scheme dependence present across these processes, and how the operator and loop expansions are not independent beyond leading order. We illustrate several cross checks of consistency in the results.

    hep-phJHEP(2021)·46 citations
16. 16*

    On the Realization of WIMPflation

    Marcos A. G. Garcia🇪🇸 · Yann Mambrini🇫🇷 · Keith A. Olive🇺🇸 · Sarunas Verner🇺🇸

    We consider models for inflation with a stable inflaton. Reheating is achieved through scattering processes such as $\varphi \varphi \to hh$, where $h$ is the Standard Model Higgs boson. We consider the reheating process in detail and show that for a relatively large coupling (needed for the late annihilations of the inflaton during freeze-out), reheating is almost instantaneous leading to a relatively high reheating temperature. The process $\varphi \varphi \leftrightarrow hh$ brings the inflaton back into equilibrium, leading to a well studied scalar singlet dark matter candidate and Higgs portal model. We argue that such models can be derived from no-scale supergravity.

    hep-phJCAP(2021)·18 citations
17. 17*

    Electron Beam Dump Constraints on Light Bosons with Lepton Flavor Violating Couplings

    Takeshi Araki🇯🇵 · Kento Asai🇯🇵 · Takashi Shimomura🇯🇵

    We study constraints on light and feebly interacting bosons with lepton flavor violation from electron beam dump experiments. Scalar, vector, and dipole interactions of the bosons are analyzed, respectively, and excluded regions from the searches for decays into electron-positron pairs are derived. It is found that parameter regions unconstrained by flavor violating decays of muon can be excluded using the results of the E137 experiment. We also discuss the impact of the search for flavor violating decays of the light bosons in electron beam dump experiments.

    hep-phJHEP(2021)·10 citations
18. 18*

    Warming up cold inflation

    William DeRocco🇺🇸 · Peter W. Graham🇺🇸 · Saarik Kalia🇺🇸

    The axion is a well-motivated candidate for the inflaton, as the radiative corrections that spoil many single-field models are avoided by virtue of its shift symmetry. However, axions generically couple to gauge sectors. As the axion slow-rolls during inflation, this coupling can cause the production of a non-diluting thermal bath, a situation known as "warm inflation." This thermal bath can dramatically alter inflationary dynamics and observable predictions. In this paper, we demonstrate that a thermal bath can form for a wide variety of initial conditions. Furthermore, we find that axion inflation becomes warm over a large range of couplings, and explicitly map the parameter space for two axion inflation potentials. We show that in large regions of parameter space, axion inflation models once assumed to be safely "cold" are in fact warm, and must be reevaluated in this context.

    hep-phastro-ph.COhep-thJCAP(2021)·40 citations
19. 19*

    Muonic Force Behind Flavor Anomalies

    Admir Greljo🇨🇭 · Yotam Soreq🇮🇱 · Peter Stangl🇨🇭 · Anders Eller Thomsen🇨🇭 · Jure Zupan🇺🇸

    We develop an economical theoretical framework for combined explanations of the flavor physics anomalies involving muons: $(g-2{)}_{\mu }$, $R_{K^{(\ast )}}$, and $b\to s{\mu }^{+}{\mu }^{-}$ angular distributions and branching ratios, that was first initiated by some of us in Ref. [1]. The Standard Model (SM) is supplemented with a lepton-flavored $\mathrm{U}(1{)}_X$ gauge group. The $\mathrm{U}(1{)}_X$ gauge boson with the mass of $\mathcal{O}(0.1)$ GeV resolves the $(g-2{)}_{\mu }$ tension. A TeV-scale leptoquark, charged under the $\mathrm{U}(1{)}_X$, carries a muon number and mediates $B$-decays without prompting charged lepton flavor violation or inducing proton decay. We explore the theory space of the chiral, anomaly-free $\mathrm{U}(1{)}_X$ gauge extensions featuring the above scenario, and identify many suitable charge assignments for the SM$+3{\nu }_R$ fermion content with the integer charges in the range $X_{F_i}\in [-10,10]$. We then carry out a comprehensive phenomenological study of the muonic force in representative benchmark models. Interestingly, we found models which can resolve the tension without conflicting the complementary constraints, and all of the viable parameter space will be tested in future muonic resonance searches. Finally, the catalog of the anomaly-free lepton-non-universal charge assignments motivated us to explore different directions in model building. We present a model in which the muon mass and the $(g-2{)}_{\mu }$ are generated radiatively from a common short-distance dynamics after the $\mathrm{U}(1{)}_X$ breaking. We also show how to charge a vector leptoquark under $\mathrm{U}(1{)}_{\mu -\tau }$ in a complete gauge model.

    hep-phhep-exJHEP(2022)·76 citations
20. 20*

    Sterile neutrino dark matter catalyzed by a very light dark photon

    Gonzalo Alonso-Álvarez🇨🇦 · James M. Cline🇨🇦

    Sterile neutrinos (${\nu }_s$) that mix with active neutrinos (${\nu }_a$) are interesting dark matter candidates with a rich cosmological and astrophysical phenomenology. In their simplest incarnation, their production is severely constrained by a combination of structure formation observations and X-ray searches. We show that if active neutrinos couple to an oscillating condensate of a very light $L_{\mu }-L_{\tau }$ gauge field, resonant ${\nu }_a$-${\nu }_s$ oscillations can occur in the early universe, consistent with ${\nu }_s$ constituting all of the dark matter, while respecting X-ray constraints on ${\nu }_s\to {\nu }_a\gamma$ decays. Interesting deviations from standard solar and atmospheric neutrino oscillations can persist to the present.

    hep-phastro-ph.COJCAP(2021)·30 citations
21. 21*

    Infrared behavior of Weyl Gravity

    Lesław Rachwał🇧🇷 · Stefano Giaccari🇮🇱

    In this paper, we introduce and motivate the studies of Quantum Weyl Gravity (also known as Conformal Gravity). We discuss some appealing features of this theory both on classical and quantum level. The construction of the quantum theory is described in detail to the one-loop level. To facilitate computations we use only physical degrees of freedom, which are singled out through the York decomposition. At the one-loop level we compute the partition function around a general Einstein space. Next, the functional renormalization group of couplings in Quantum Weyl Gravity is investigated. We reproduce completely previous results obtained on maximally symmetric and Ricci-flat backgrounds. Finally, we comment on further directions and on the issue of conformal anomaly.

    ↳ hep-thgr-qchep-phJ.Phys.Conf.Ser.(2021)·2 citations
22. 22*

    Negative Infrared Divergent Corrections to the Global String Tension

    Daniel Davies🇺🇸

    We show that at large distances from an infinitely long global U(1) string, low energy Goldstone Bosons contribute a spatially dependent term to the energy density which is non-integrable. Specifically, this term diverges with the same form as the classical field theory contribution to the string tension, except with negative sign. This suggests that a careful analysis of the infrared degrees of freedom around the global string ought to yield an effective theory of the solitary string whose tension is finite. There are implications for axion cosmology.

    ↳ hep-thhep-ph2 citations
23. 23*

    Probing horizon scale quantum effects with Love

    Sayak Datta🇮🇳

    Future gravitational wave detectors have been projected to be able to probe the nature of compact objects in great detail. In this work, we study the potential observability of the small length scale physics near black hole horizon with the tidal deformability of the compact objects in an inspiraling binary. We find that it is possible to probe them with extreme mass ratio inspirals. We discuss how the quantum effects can affect the gravitational wave observables. This as a consequence is bound to shape our understanding of the quantum scale near the horizon.

    ↳ gr-qcastro-ph.HEhep-phhep-thClass.Quant.Grav.(2022)·26 citations
24. 24*

    Kondo effect with Wilson fermions

    Tsutomu Ishikawa🇯🇵 · Katsumasa Nakayama🇩🇪 · Kei Suzuki🇯🇵

    We investigate the Kondo effect with Wilson fermions. This is based on a mean-field approach for the chiral Gross-Neveu model including four-point interactions between a light Wilson fermion and a heavy fermion. For massless Wilson fermions, we demonstrate the appearance of the Kondo effect. We point out that there is a coexistence phase with both the light-fermion scalar condensate and Kondo condensate, and the critical chemical potentials of the scalar condensate are shifted by the Kondo effect. For negative-mass Wilson fermions, we find that the Kondo effect is favored near the parameter region realizing the Aoki phase. Our findings will be useful for understanding the roles of heavy impurities in Dirac semimetals, topological insulators, and lattice simulations.

    ↳ hep-latcond-mat.mes-hallcond-mat.str-elhep-phPRD(2021)·8 citations
25. 25*

    Extracting the Signal of Cosmic String Wakes from 21-cm Observations

    David Maibach🇨🇭 · Robert Brandenberger🇨🇦 · Devin Crichton🇨🇭 · Alexandre Refregier🇨🇭

    A cosmic string wake produces a distinct non-Gaussian signal in 21-cm intensity maps at redshifts above that of reionization. While the string signal is (locally) larger in amplitude than the signal of the Gaussian fluctuations of the $\Lambda$CDM model, they are overwhelmed (even locally in position space) by astrophysical and instrumental foregrounds. Here, we study to what extent the signal can be extracted from noisy interferometric data. The narrowness of the string-induced feature in redshift direction allows for a subtraction of astrophysical and instrumental foregrounds. Based on the specific geometry of the string signal we identify a particular three-point statistic which is promising in order to extract the signal, and we find that, having in mind a telescope of specifications similar to that of the MWA instrument, the string signal can be successfully extracted for a value of the string tension of $G\mu =3\times 10^{-7}$. Prospects for further improvements of the analysis are discussed.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2021)·18 citations
26. 26*

    The primordial black hole from running curvaton

    Lei-Hua Liu🇨🇳

    In light of our previous work \cite{Liu:2019xhn}, we investigate the possibility of the formation of a primordial black hole in the second inflationary process induced by the oscillation of curvaton. By adopting the instability of the Mathieu equation, one could utilize the $\delta$ function to fully describe the power spectrum. Due to the running of curvaton mass, we can simulate the value of abundance of primordial black holes nearly covering all of the mass ranges, in which we have given three special cases. One case could account for the dark matter in some sense since the abundance of a primordial black hole is about $75\%$. At late times, the relic of exponential potential could be approximated to a constant of the order of cosmological constant dubbed as a role of dark energy. Thus, our model could unify dark energy and dark matter from the perspective of phenomenology. Finally, it sheds new light on exploring Higgs physics.

    ↳ astro-ph.COgr-qchep-phCPC(2023)·28 citations
27. 27*

    Slow diffusion is necessary to explain the gamma-ray pulsar halos

    Li-Zhuo Bao · Kun Fang🇨🇳 · Xiao-Jun Bi🇨🇳 · Sheng-Hao Wang🇨🇳

    It was suggested that the $\gamma$-ray halo around Geminga might not be interpreted by slow-diffusion. If the ballistic regime of electron/positron propagation is considered, the Geminga halo may be explained even with a large diffusion coefficient. In this work, we examine this effect by taking the generalized Jüttner propagator as the approximate relativistic Green's function for diffusion and find that the morphology of the Geminga halo can be marginally fitted in the fast-diffusion scenario. However, the recently discovered $\gamma$-ray halo around PSR J0622$+$3749 at LHAASO cannot be explained by the same effect and slow diffusion is the only solution. Furthermore, both the two pulsar halos require a conversion efficiency from the pulsar spin-down energy to the high energy electrons/positrons much larger than 100\%, if they are interpreted by this ballistic transport effect. Therefore, we conclude that slow diffusion is necessary to account for the $\gamma$-ray halos around pulsars.

    ↳ astro-ph.HEastro-ph.GAhep-phApJ(2022)·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.