Fri·Feb 22, 2019Friday·February 22, 2019

1. 01*

   Cosmological Magnetic Field and Dark Energy as two sides of the same coin

   Ariel R. Zhitnitsky🇨🇦

   It has been recently argued \cite{Barvinsky:2017lfl} that the de Sitter phase in cosmology might be naturally generated as a result of dynamics of the topologically nontrivial sectors in a strongly coupled QCD-like gauge theory in expanding universe. It is known that the de Sitter phase is realized in the history of our Universe twice: the first occurrence is coined as the inflation, while the second time (which is occurring now) is dubbed as the dark energy (DE). The crucial element of the proposal \cite{Barvinsky:2017lfl} is the presence of a nontrivial gauge holonomy which is the source of the vacuum energy leading to the de Sitter behaviour. It has been also argued that the anomalous coupling of the system with the Standard Model (SM) particles leads to the reheating epoch in case of the {\it inflationary} phase. A similar anomalous coupling of the system with the Maxwell $E\&M$ field during the {\it DE epoch} generates the cosmological magnetic field. The intensity of the field is estimated on the level of $10^{-10}$G while the corresponding correlation length reaches the scale of the visible Universe.

   hep-phastro-ph.COPRD(2019)·4 citations
2. 02*

   LIGO/Virgo Black Holes from a First Order QCD Phase Transition

   Hooman Davoudiasl🇺🇸

   We propose that $O(10M_{\mathrm{Sun}})$ black holes observed by LIGO/Virgo originate from a first order QCD phase transition at a temperature $T_{\ast }\lesssim 100$~MeV. This is realized by keeping the quark masses small compared to confinement scale down to $T\sim T_{\ast }$, making QCD transition first order. We implement this scenario using a light scalar that could potentially be a good dark matter candidate.

   hep-phastro-ph.COPRL(2019)·17 citations
3. 03*

   Single-spin asymmetry in dihadron production in SIDIS off the longitudinally polarized nucleon target

   Wei Yang🇨🇳 · Xiaoyu Wang🇨🇳 · Yongliang Yang🇨🇳 · Zhun Lu🇨🇳

   We study the single longitudinal-spin asymmetry of dihadron production in semi-inclusive deep inelastic scattering process. We consider the collinear picture in which the transverse momentum of the final-state hadron pair is integrated out, such that the $\sin {\varphi }_R$ azimuthal asymmetry arises from the coupling $h_L{H}_1^{\sphericalangle }$ as well as the coupling $g_1{\tilde{G}}^{\sphericalangle }$. We calculate the unknown twist-3 dihadron fragmentation function ${\tilde{G}}^{\sphericalangle }$ using a spectator model which is successful in describing the dihadron production in the unpolarized process. Using the spectator model results for the quark distributions and dihadron fragmentation functions, we estimate the $\sin {\varphi }_R$ asymmetry of dihadron production in SIDIS at the kinematics of COMPASS and compare it with the COMPASS preliminary data. In addition, the prediction on the $\sin {\varphi }_R$ asymmetry at the typical kinematics of the future Electron Ion Collider is also presented. In order to test the reliability of the spectator model estimate, we compare the model result for the distribution $h_L$ with the Wandzura-Wilczek approximation for that distribution, and compare $H_1^{\sphericalangle }$ with the existing parametrization. Although the asymmetry is dominated by the $h_L{H}_1^{\sphericalangle }$ term, we find that the contribution from the $g_1{\tilde{G}}^{\sphericalangle }$ term should also be taken into account in certain kinematical region.

   hep-phhep-exPRD(2019)·12 citations
4. 04*

   Charged neutron stars and observational tests of a dark force weaker than gravity

   Marco Fabbrichesi🇮🇹 · Alfredo Urbano🇮🇹

   We discuss the possibility of exploring an unbroken U(1) gauge interaction in the dark sector by means of gravitational waves. Dark sector states charged under the dark force can give a macroscopic charge to astronomical bodies. Yet the requirement of having gravitationally bounded stars limits this charge to negligible values if the force has a sizeable strength. Gravitational tests are only possible if the dark force is weaker than gravity. By solving the Einstein-Maxwell field equations, we study in detail an explicit model for dark charge generation and separation in a neutron star. Charged states originate from the decay of neutrons inside the star into three dark fermions; we show that in this model the equation of state is consistent with limits on neutron star masses and tidal deformability. We find that while the dark force can be observed in binary mergers (making them an optimal observational test even though with limited precision), it is Debye screened in binary pulsars (for which more precise data exist). The emitted radiation in the inspiral phase of a binary system is modified and the dark force tested at the level of the uncertainty of the experimental detection. The test covers a region where current limits on deviations from Newton inverse-squared law come from geophysical and laser-ranging observations.

   hep-phgr-qcJCAP(2020)·18 citations
5. 05*

   Violation of Wiedemann-Franz Law for Hot Hadronic Matter created at NICA, FAIR and RHIC Energies using Non-extensive Statistics

   Rutuparna Rath🇮🇳 · Sushanta Tripathy🇮🇳 · Bhaswar Chatterjee🇮🇳 · Raghunath Sahoo🇮🇳 · Swatantra K. Tiwari🇮🇳 · Abhishek Nath🇮🇳

   We present here the computation of electrical and thermal conductivity by solving the Boltzmann transport equation in relaxation time approximation. We use the $q$-generalized Boltzmann distribution function to incorporate the effects of non-extensivity. The behaviour of these quantities with changing temperature and baryochemical potential has been studied as the system slowly moves towards thermodynamic equilibrium. We have estimated the Lorenz number at NICA, FAIR and the top RHIC energies and studied as a function of temperature, baryochemical potential and the non-extensive parameter, $q$. We have observed that Wiedemann-Franz law is violated for a non-extensive hadronic phase as well as for an equilibrated hadron gas at high temperatures.

   hep-phnucl-thEPJA(2019)·13 citations
6. 06*

   Thermal radiation and inclusive production in the CGC/saturation approach at high energies

   E. Gotsman (Tel Aviv U.)🇮🇱 · E. Levin (Tel Aviv U./UTFSM)🇮🇱

   In this paper, we discuss the inclusive production of hadrons in the framework of CGC/saturation approach. We argue, that the gluon jet inclusive production stems from the vicinity of the saturation momentum, even for small values of the transverse momenta $p_T$. Since in this region, theoretically, we know the scattering amplitude, we claim that we can provide reliable estimates for this process. We demonstrate, that in a widely accepted model for confinement, to describe the experimental data, we require a thermal radiation term. In this model the parton (quark or gluon) with the transverse momenta of the order of $Q_s$ decays into hadrons with the given fragmentation functions. However, we show that other approaches for the confinement could describe the data, without a need for the thermal emission

   hep-phEPJC(2019)·13 citations
7. 07*

   Low $x$ physics as an infinite twist (G)TMD framework: unravelling the origins of saturation

   Tolga Altinoluk🇵🇱 · Renaud Boussarie🇺🇸

   We show how the formulations of low $x$ physics involving Wilson line operators can be fully rewritten into an infinite twist TMD or GTMD framework, respectively for inclusive and exclusive observables. This leads to a perfect match between low $x$ physics and moderate $x$ formulations of QCD in terms of GTMDs, TMDs, GPDs or PDFs. We derive the BFKL limit as a kinematic limit and argue that beyond the Wandzura-Wilczek approximation, 3-body and 4-body unintegrated PDFs should be taken into account even in this regime. Finally, we analyze how saturation should be understood as three distinct effects: saturation through non-linearities in the evolution equations at small $x$, saturation through multiple interactions with slow gluons as TMD gauge links, and saturation as the enhancement of genuine twist corrections.

   hep-phJHEP(2019)·72 citations
8. 08*

   Two-loop splitting in double parton distributions

   Markus Diehl🇩🇪 · Jonathan R. Gaunt🇨🇭 · Peter Ploessl🇩🇪 · Andreas Schafer🇩🇪

   Double parton distributions (DPDs) receive a short-distance contribution from a single parton splitting to yield the two observed partons. We investigate this mechanism at next-to-leading order (NLO) in perturbation theory. Technically, we compute the two-loop matching of both the position and momentum space DPDs onto ordinary PDFs. This also yields the 1 -> 2 splitting functions appearing in the evolution of momentum-space DPDs at NLO. We give results for the unpolarised, colour-singlet DPDs in all partonic channels. These quantities are required for calculations of double parton scattering at full NLO. We discuss various kinematic limits of our results, and we verify that the 1 -> 2 splitting functions are consistent with the number and momentum sum rules for DPDs.

   hep-phSciPost Phys.(2019)·29 citations
9. 09*

   Clifford-based spectral action and renormalization group analysis of the gauge couplings

   Ufuk Aydemir🇨🇳

   The Spectral Action Principle in noncommutative geometry derives the actions of the Standard Model and General Relativity (along with several other gravitational terms) by reconciling them in a geometric setting, and hence offers an explanation for their common origin. However, one of the requirements in the minimal formalism, unification of the gauge coupling constants, is not satisfied, since the basic construction does not introduce anything new that can change the renormalization group (RG) running of the Standard Model. On the other hand, it has been recently argued that incorporating structure of the Clifford algebra into the finite part of the spectral triple, the main object that encodes the complete information of a noncommutative space, gives rise to five additional scalar fields in the basic framework. We investigate whether these scalars can help to achieve unification. We perform a RG analysis at the one-loop level, allowing possible mass values of these scalars to float from the electroweak scale to the putative unification scale. We show that out of twenty configurations of mass hierarchy in total, there does not exist even a single case that can lead to unification. In consequence, we confirm that the spectral action formalism requires a model-construction scheme beyond the (modified) minimal framework.

   hep-phhep-thmath-phmath.MPEPJC(2019)·4 citations
10. 10*

    Boosted Top quark polarization

    Rohini Godbole🇮🇳 · Monoranjan Guchait🇮🇳 · Charanjit K. Khosa🇬🇧 · Jayita Lahiri🇮🇳 · Seema Sharma🇮🇳 · Aravind H. Vijay🇮🇳

    In top quark production, the polarization of top quarks, decided by the chiral structure of couplings, is likely to be modified in the presence of any new physics contribution to the production. Hence the same is a good discriminator for those new physics models wherein the couplings have a chiral structure different than that in the Standard Model (SM). In this note we construct probes of the polarization of a top quark decaying hadronically, using easily accessible kinematic variables such as the energy fraction or angular correlations of the decay products. Tagging the boosted top quark using the usual jet sub structure technique we study robustness of these observables for a benchmark process, $W^{\prime }\to tb$. We demonstrate that the energy fraction of b-jet in the laboratory frame and a new angular variable, constructed by us in the top rest frame, are both very powerful tools to discriminate between the left and right polarized top quarks. Based on the polarization sensitive angular variables, we construct asymmetries which reflect the polarization. We study the efficiency of these variables for two new physics processes where which give rise to boosted top quarks: (i) decay of the top squark in the context of supersymmetry searches, and (ii) decays of the Kaluza-Klein(KK) graviton and KK gluon, in Randall Sundrum(RS) model. Remarkably, it is found that the asymmetry can vary over a wide range about +20\% to -20\%. The dependence of asymmetry on top quark couplings of the new particles present in these models beyond the SM (BSM) is also investigated in detail.

    hep-phhep-exPRD(2019)·16 citations
11. 11*

    Addressing the ${\mathbf{R}}_{D^{(\ast )}}$ anomalies with an ${\mathbf{S}}_1$ leptoquark from $\mathbf{SO}(10)$ grand unification

    Ufuk Aydemir🇨🇳 · Tanumoy Mandal🇸🇪 · Subhadip Mitra🇮🇳

    Motivated by the $R_{D^{(\ast )}}$ anomalies, we investigate an $\mathrm{SO}(10)$ grand unification scenario where a charge $-1/3$ scalar leptoquark ($S_1$) remains as the only new physics candidate at the TeV scale. This leptoquark along with the Standard Model (SM) Higgs doublet originates from the same 10-dimensional real scalar multiplet in the $\mathrm{SO}(10)$ grand unification framework taking its mass close to the electroweak scale. We explicitly show how the gauge coupling unification is achieved with only one intermediate symmetry-breaking scale at which the Pati-Salam gauge group is broken into the SM group. We investigate the phenomenological implications of our scenario and show that an $S_1$ with a specific Yukawa texture can explain the $R_{D^{(\ast )}}$ anomalies. We perform a multiparameter scan considering the relevant flavour constraints on $R_{D^{(\ast )}}$, $F_L(D^{\ast })$, $P_{\tau }(D^{\ast })$ and $R_{K^{(\ast )}}^{\nu \nu }$ as well as the constraint coming from the $Z\to \tau \tau$ decay and the latest $\tau \tau$ resonance search data at the LHC. Our analysis shows that a single leptoquark solution to the observed $R_{D^{(\ast )}}$ anomalies with $S_1$ is still a viable solution.

    hep-phPRD(2020)·79 citations
12. 12*

    Exclusive vector meson production in heavy ion collisions

    V.A.Khoze🇬🇧 · A.D.Martin🇬🇧 · M.G.Ryskin🇬🇧

    We discuss the salient features of exclusive vector meson production in heavy ion collisions at LHC energies. Special attention is paid to the space-time picture of the process. We account for both coherent and incoherent contributions. The explicit quantitative predictions are given for the $\rho$-meson differential cross section in lead-lead collisions in different kinematical configurations relevant for the LHCb and ALICE experiments.

    hep-phJ.Phys.G(2019)·11 citations
13. 13*

    Effective-field theory analysis of the ${\tau }^{-}\to (K\pi {)}^{-}{\nu }_{\tau }$ decays

    Javier Rendón🇲🇽 · Pablo Roig🇲🇽 · Genaro Toledo🇲🇽

    We analyze the ${\tau }^{-}\to (K\pi {)}^{-}{\nu }_{\tau }$ decays within an effective field theory description of heavy new physics (NP) modifying the SM left-handed weak charged current and include refined SM input for the participant meson form factors exploiting chiral symmetry, dispersion relations and (lattice) data. We include the leading dimension six operators and work at linear order in the effective couplings. Within this setting we: i) follow the derivation in Phys. Rev. Lett. 120 (2018) no.14, 141803 where it was proved unambiguously that it is impossible to understand the BaBar anomaly in the CP asymmetry measurement within this framework. We allow for reasonable variations of the hadronic input involved and study the associated uncertainty; ii) first show that the anomalous bump present in the published Belle data for the $K_S{\pi }^{-}$ invariant mass distribution close to threshold cannot be due to heavy NP; iii) first bind the heavy NP effective couplings using ${\tau }^{-}\to (K\pi {)}^{-}{\nu }_{\tau }$ decays and show that they are competitive with those found in hyperon semileptonic decays (but clearly not with those obtained in Kaon (semi)leptonic decays for NP scalar currents). We put forward that the comparison of the considered tau decays with (semi)leptonic kaon and hyperon decays provide with meaningful tests of lepton universality for (NP) tensor interactions. We also compare the SM predictions with the possible deviations caused by NP in a couple of Dalitz plot distributions, in the forward-backward asymmetry and in the di-meson invariant mass distribution and discuss the most interesting measurements to be performed at Belle-II using these decays data.

    hep-phhep-exPRD(2019)·55 citations
14. 14*

    The strong running coupling from the gauge sector of Domain Wall lattice QCD with physical quark masses

    S. Zafeiropoulos🇩🇪 · Ph. Boucaud🇫🇷 · F. De Soto🇪🇸 · J. Rodríguez-Quintero🇪🇸 · J. Segovia🇪🇸

    We report on the first computation of the strong running coupling at the physical point (physical pion mass) from the ghost-gluon vertex, computed from lattice simulations with three flavors of Domain Wall fermions. We find ${\alpha }_{\overline{\mathrm{MS}}}(m_Z^2)=0.1172(11)$, in remarkably good agreement with the world-wide average. Our computational bridge to this value is the Taylor-scheme strong coupling, which has been revealed of great interest by itself because it can be directly related to the quark-gluon interaction kernel in continuum approaches to the QCD bound-state problem.

    hep-phhep-latnucl-thPRL(2019)·86 citations
15. 15*

    BFKL Pomeron and the survival factor

    V.A.Khoze🇬🇧 · A.D.Martin🇬🇧 · M.G.Ryskin🇬🇧

    We consider the absorptive corrections and the rapidity gap survival factor which are necessary to provide the unitarization of the BFKL Pomeron. In particular we discuss the role of the enhanced screening diagrams.

    hep-ph0 citations
16. 16*

    High precision determination of ${\alpha }_s$ from a global fit of jet rates

    Andrii Verbytskyi🇩🇪 · Andrea Banfi🇬🇧 · Adam Kardos🇭🇺 · Pier Francesco Monni🇨🇭 · Stefan Kluth🇩🇪 · Gábor Somogyi🇭🇺 · Zoltán Szőr🇩🇪 · Zoltán Trócsányi🇭🇺 · Zoltán Tulipánt🇭🇺 · Giulia Zanderighi🇩🇪

    We present state-of-the-art extractions of the strong coupling based on N${}^3$LO+NNLL accurate predictions for the two-jet rate in the Durham clustering algorithm at $e^{+}{e}^{-}$ collisions, as well as a simultaneous fit of the two- and three-jet rates taking into account correlations between the two observables. The fits are performed on a large range of data sets collected at LEP and PETRA colliders, with energies spanning from $35$ GeV to $207$ GeV. Owing to the high accuracy of the predictions used, the perturbative uncertainty is considerably smaller than that due to hadronization. Our best determination at the $Z$ mass is ${\alpha }_s(M_Z)=0.11881\pm 0.00063(exp.)\pm 0.00101(hadr.)\pm 0.00045(ren.)\pm 0.00034(res.)$, which is in agreement with the latest world average and has a comparable total uncertainty.

    hep-phJHEP(2019)·45 citations
17. 17*

    Neutrino eigenstates and flavour, spin and spin-flavour oscillations in a constant magnetic field

    Artem Popov🇷🇺 · Alexander Studenikin🇷🇺

    We further develop a recently proposed new approach to the description of the relativistic neutrino flavour ${\nu }_e^L\leftrightarrow {\nu }_{\mu }^L$, spin ${\nu }_e^L\leftrightarrow {\nu }_e^R$ and spin-flavour ${\nu }_e^L\leftrightarrow {\nu }_{\mu }^R$ oscillations in a constant magnetic field that is based on the use of the exact neutrino stationary states in the magnetic field. The neutrino flavour, spin and spin-flavour oscillations probabilities are calculated accounting for the whole set of possible conversions between four neutrino states. In general, the obtained expressions for the neutrino oscillations probabilities exhibit new inherent features in the oscillation patterns. It is shown, in particular, that: 1) in the presence of the transversal magnetic field for a given choice of parameters (the energy and magnetic moments of neutrinos and the strength of the magnetic field) the amplitude of the flavour oscillations ${\nu }_e^L\leftrightarrow {\nu }_{\mu }^L$ at the vacuum frequency is modulated by the magnetic field frequency, 2) the neutrino spin oscillation probability (without change of the neutrino flavour) exhibits the dependence on the mass square difference $\Delta m^2$. It is shown that the discussed interplay of neutrino oscillations in magnetic fields on different frequencies can have important consequences in astrophysical environments, in particular in those peculiar for magnetars.

    hep-phEPJC(2019)·46 citations
18. 18*

    Quark and gluon form factors in four loop QCD: the $N_f^2$ and $N_{q\gamma }{N}_f$ contributions

    Andreas von Manteuffel🇺🇸 · Robert M. Schabinger🇺🇸

    We calculate the four-loop massless QCD corrections with two closed quark lines to quark and gluon form factors. The results for the gluon form factor and the singlet part of the quark form factor are given for the first time. From our analytic expressions for the form factors, we determine the corresponding cusp anomalous dimensions. The relevant Feynman integrals are obtained with novel integral reduction techniques and direct integration methods.

    hep-phhep-thPRD(2019)·47 citations
19. 19*

    Composite Twin Dark Matter

    John Terning🇺🇸 · Christopher B. Verhaaren🇺🇸 · Kyle Zora🇺🇸

    We consider Fraternal Twin Higgs models where the twin bottom quark, $b^{\prime }$, is much heavier than the twin confinement scale. In this limit aspects of quark bound states, like the mass and binding energy, can be accurately calculated. We show that in this regime, dark matter can be primarily made of twin baryons containing $b^{\prime }{b}^{\prime }{b}^{\prime }$ or, when twin hypercharge is gauged, twin atoms, composed of a baryon bound to a twin ${\tau }^{\prime }$ lepton. We find that there are significant regions of parameter space which are allowed by current constraints but within the realm of detection in the near future. The case with twin atoms can alleviate the tension between dark matter properties inferred from dwarf galaxies and clusters.

    hep-phPRD(2019)·48 citations
20. 20*

    Relaxion Stars and their detection via Atomic Physics

    Abhishek Banerjee🇮🇱 · Dmitry Budker🇩🇪 · Joshua Eby🇮🇱 · Hyungjin Kim🇮🇱 · Gilad Perez🇮🇱

    The cosmological relaxion can address the hierarchy problem, while its coherent oscillations can constitute dark matter in the present universe. We consider the possibility that the relaxion forms gravitationally bound objects that we denote as relaxion stars. The density of these stars would be higher than that of the local dark matter density, resulting in enhanced signals in table-top detectors, among others. Furthermore, we raise the possibility that these objects may be trapped by an external gravitational potential, such as that of the Earth or the Sun. This leads to formation of relaxion halos of even greater density. We discuss several interesting implications of relaxion halos, as well as detection strategies to probe them.

    hep-phastro-ph.COphysics.atom-phCommun.Phys.(2020)·237 citations
21. 21*

    Probe of the Randall-Sundrum-like model with the small curvature via light-by-light scattering at the LHC

    S.C. Inan🇹🇷 · A.V. Kisselev🇷🇺

    The LHC possibilities to constrain the parameters of the Randall-Sundrum-like model with one warped extra dimension and small curvature through the diphoton production in the photon-induced process pp -> p gamma gamma p -> p' gamma gamma p' are investigated. Two acceptances of the forward detectors, 0.015 < xi < 0.15 and 0.015 < xi < 0.5, where xi is the fractional proton momentum loss of the incident protons, are considered. The sensitivity bounds on the 5-dimensional gravity scale are obtained as a function of the LHC integrated luminosity.

    hep-phhep-exPRD(2019)·17 citations
22. 22*

    Origin of Yukawa couplings for Higgs and leptoquarks

    Ivo de Medeiros Varzielas🇵🇹 · Stephen F. King🇬🇧

    We propose a model in which the Yukawa couplings of Higgs doublets are related to the couplings of the chiral fermions to a scalar leptoquark triplet. This is due to their common origin via mixing with a vector-like family distinguished by a discrete $Z_5$ symmetry, under which only the three chiral families are neutral. The model predicts lepton non-universality in $B$ to $K$ decays, depending on the leptoquark mass, $V_{ts}$ and $m_{\mu }/m_{\tau }$. The model can only consistently explain the anomalies in $R_{K^{(\ast )}}$ for a leptoquark mass close to the collider lower bound of about $1\text{TeV}$. Constraints from $B_s-{\bar{B}}_s$ mixing and eventually $\tau \to \mu \gamma$ become relevant for low leptoquark masses and large couplings, while $\mu \to e\gamma$ remains automatically under control due to the absence of leptoquark couplings to the electron in this model.

    hep-phPRD(2019)·21 citations
23. 23*

    Superasymptotic and hyperasymptotic approximation to the operator product expansion

    Cesar Ayala🇨🇱 · Xabier Lobregat🇪🇸 · Antonio Pineda🇪🇸

    Given an observable and its operator product expansion (OPE), we present expressions that carefully disentangle truncated sums of the perturbative series in powers of $\alpha$ from the non-perturbative (NP) corrections. This splitting is done with NP power accuracy. Analytic control of the splitting is achieved and the organization of the different terms is done along an super/hyper-asymptotic expansion. As a test we apply the methods to the static potential in the large ${\beta }_0$ approximation. We see the superasymptotic and hyperasymptotic structure of the observable in full glory.

    ↳ hep-thhep-lathep-phmath-ph+1PRD(2019)·40 citations
24. 24*

    Development of an analysis to probe the neutrino mass ordering with atmospheric neutrinos using three years of IceCube DeepCore data

    M. G. Aartsen · M. Ackermann · J. Adams · J. A. Aguilar · M. Ahlers · M. Ahrens · C. Alispach · K. Andeen · T. Anderson · I. Ansseau · G. Anton · C. Argüelles and 324 other authors

    The Neutrino Mass Ordering (NMO) remains one of the outstanding questions in the field of neutrino physics. One strategy to measure the NMO is to observe matter effects in the oscillation pattern of atmospheric neutrinos above $\sim 1\mathrm{GeV}$, as proposed for several next-generation neutrino experiments. Moreover, the existing IceCube DeepCore detector can already explore this type of measurement. We present rthe development and application of two independent analyses to search for the signature of the NMO with three years of DeepCore data. These analyses include a full treatment of systematic uncertainties and a statistically-rigorous method to determine the significance for the NMO from a fit to the data. Both analyses show that the dataset is fully compatible with both mass orderings. For the more sensitive analysis, we observe a preference for Normal Ordering with a $p$-value of $p_{\mathrm{IO}}=15.3\%$ and ${\mathrm{CL}}_{\mathrm{s}}=53.3\%$ for the Inverted Ordering hypothesis, while the experimental results from both analyses are consistent within their uncertainties. Since the result is independent of the value of ${\delta }_{\mathrm{CP}}$ and obtained from energies $E_{\nu }\gtrsim 5\mathrm{GeV}$, it is complementary to recent results from long-baseline experiments. These analyses set the groundwork for the future of this measurement with more capable detectors, such as the IceCube Upgrade and the proposed PINGU detector.

    ↳ hep-exhep-phEPJC(2020)·56 citations
25. 25*

    Palatini formulation of pure $R^2$ gravity yields Einstein gravity with no massless scalar

    Ariel Edery🇨🇦 · Yu Nakayama🇯🇵

    Pure $R^2$ gravity has been shown to be equivalent to Einstein gravity with non-zero cosmological constant and a massless scalar field. We show that the Palatini formulation of pure $R^2$ gravity is equivalent to Einstein gravity with non-zero cosmological constant as before but with no massless scalar field. This is an important new development because the massless scalar field is not readily identifiable with any known particle in nature or unknown particles like cold dark matter which are expected to be massive. We then include a non-minimally coupled Higgs field as well as fermions to discuss how the rest of the standard model fields fit into this paradigm. With Higgs field, Weyl invariance is maintained by using a hybrid formalism that includes both the Palatini curvature scalar $\mathcal{R}$ and the usual Ricci scalar $R$

    ↳ hep-thgr-qchep-phPRD(2019)·65 citations
26. 26*

    On Future High-Energy Colliders

    Gian Francesco Giudice🇨🇭

    An outline of the physics reasons to pursue a future programme in high-energy colliders is presented.

    ↳ physics.hist-phhep-exhep-phhep-th5 citations
27. 27*

    Scattering amplitudes versus potentials in nuclear effective field theory: search for a potential compromise

    Manuel Pavon Valderrama🇨🇳

    In effective field theory physical quantities, in particular observables, are expressed as a power series in terms of a small expansion parameter. For non-perturbative systems, for instance nuclear physics, this requires the non-perturbative treatment of at least part of the interaction (or the potential, if one is dealing with a non-relativistic system), while the rest of the interaction is included as perturbations. This is not entirely trivial and as a consequence different interpretations on how to treat these systems have appeared. A practical approach is to expand the effective potential, where this potential is later fully iterated in the Schroedinger equation for obtaining amplitudes and observables. The expectation is that this will lead to observables that will have an implicit power counting expansion. Here I explicitly check whether the amplitudes (when expanded according to the counting) are actually following the same power counting as the potential. It happens that reality does not necessarily conform to expectations and the amplitudes will sometimes violate the power counting with which the potential has been expanded. A more formal approach is to formulate the expansion directly in terms of amplitudes and observables, which is the original aim of the effective field theory idea. Yet this second approach is technically complicated. I explore here the possibility of constructing potentials that when fully iterated will make sure that amplitudes are indeed expansible in terms of a small expansion parameter.

    ↳ nucl-thhep-phPRC(2025)·22 citations
28. 28*

    Instability of exotic compact objects and its implications for gravitational-wave echoes

    Baoyi Chen🇺🇸 · Yanbei Chen🇺🇸 · Yiqiu Ma🇺🇸 · Ka-Lok R. Lo🇺🇸 · Ling Sun🇺🇸

    Exotic compact objects (ECOs) have recently become an exciting research subject, since they are speculated to have a special response to the incident gravitational waves (GWs) that leads to GW echoes. We show that energy carried by GWs can easily cause the event horizon to form out of a static ECO --- leaving no echo signals towards spatial infinity. To show this, we use the ingoing Vaidya spacetime and take into account the back reaction due to incoming GWs. Demanding that an ECO does not collapse into a black hole puts an upper bound on the compactness of the ECO, at the cost of less distinct echo signals for smaller compactness. The trade-off between echoes' detectability and distinguishability leads to a fine tuning of ECO parameters for LIGO to find distinct echoes. We also show that an extremely compact ECO that can survive the gravitational collapse and give rise to GW echoes might have to expand its surface in a non-causal way.

    ↳ gr-qcastro-ph.HEhep-ph28 citations
29. 29*

    When Primordial Black Holes from Sound Speed Resonance Meet a Stochastic Background of Gravitational Waves

    Yi-Fu Cai🇨🇳 · Chao Chen🇨🇳 · Xi Tong🇨🇳 · Dong-Gang Wang🇳🇱 · Sheng-Feng Yan🇨🇳

    As potential candidates of dark matter, primordial black holes (PBHs) are within the core scopes of various astronomical observations. In light of the explosive development of gravitational wave (GW) and radio astronomy, we thoroughly analyze a stochastic background of cosmological GWs, induced by over large primordial density perturbations, with several spikes that was inspired by the sound speed resonance effect and can predict a particular pattern on the mass spectrum of PBHs. With a specific mechanicsm for PBHs formation, we for the first time perform the study of such induced GWs that originate from both the inflationary era and the radiation-dominated phase. We report that, besides the traditional process of generating GWs during the radiation-dominated phase, the contribution of the induced GWs in the sub-Hubble regime during inflation can become significant at critical frequency band because of a narrow resonance effect. All contributions sum together to yield a specific profile of the energy spectrum of GWs that can be of observable interest in forthcoming astronomical experiments. Our study shed light on the possible joint probe of PBHs via various observational windows of multi-messenger astronomy, including the search for electromagnetic effects with astronomical telescopes and the stochastic background of relic GWs with GW instruments.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2019)·135 citations
30. 30*

    FLAG Review 2019

    S. Aoki🇯🇵 · Y. Aoki🇯🇵 · D. Becirevic🇫🇷 · T. Blum🇺🇸 · G. Colangelo🇨🇭 · S. Collins🇩🇪 · M. Della Morte🇩🇰 · P. Dimopoulos🇮🇹 · S. Dürr🇩🇪 · H. Fukaya🇯🇵 · M. Golterman🇺🇸 · Steven Gottlieb🇺🇸 and 23 other authors

    We review lattice results related to pion, kaon, $D$-meson, $B$-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More specifically, we report on the determination of the light-quark masses, the form factor $f_{+}(0)$ arising in the semileptonic $K\to \pi$ transition at zero momentum transfer, as well as the decay constant ratio $f_K/f_{\pi }$ and its consequences for the CKM matrix elements $V_{us}$ and $V_{ud}$. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of $SU(2{)}_L\times SU(2{)}_R$ and $SU(3{)}_L\times SU(3{)}_R$ Chiral Perturbation Theory. We review the determination of the $B_K$ parameter of neutral kaon mixing as well as the additional four $B$ parameters that arise in theories of physics beyond the Standard Model. For the heavy-quark sector, we provide results for $m_c$ and $m_b$ as well as those for $D$- and $B$-meson decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. We review the status of lattice determinations of the strong coupling constant ${\alpha }_s$. Finally, in this review we have added a new section reviewing results for nucleon matrix elements of the axial, scalar and tensor bilinears, both isovector and flavor diagonal.

    ↳ hep-lathep-phEPJC(2020)·940 citations
31. 31*

    TeV Halos are Everywhere: Prospects for New Discoveries

    Takahiro Sudoh🇯🇵 · Tim Linden🇺🇸 · John F. Beacom🇺🇸

    Milagro and HAWC have detected extended TeV gamma-ray emission around nearby pulsar wind nebulae (PWNe). Building on these discoveries, Linden et al. [1] identified a new source class -- TeV halos -- powered by the interactions of high-energy electrons and positrons that have escaped from the PWN, but which remain trapped in a larger region where diffusion is inhibited compared to the interstellar medium. Many theoretical properties of TeV halos remain mysterious, but empirical arguments suggest that they are ubiquitous. The key to progress is finding more halos. We outline prospects for new discoveries and calculate their expectations and uncertainties. We predict, using models normalized to current data, that future HAWC and CTA observations will detect in total $\sim$50--240 TeV halos, though we note that multiple systematic uncertainties still exist. Further, the existing HESS source catalog could contain $\sim$10--50 TeV halos that are presently classified as unidentified sources or PWN candidates. We quantify the importance of these detections for new probes of the evolution of TeV halos, pulsar properties, and the sources of high-energy gamma rays and cosmic rays.

    ↳ astro-ph.HEastro-ph.GAhep-phPRD(2019)·104 citations
32. 32*

    Observational Signatures of Quantum Gravity in Interferometers

    Erik P. Verlinde🇳🇱 · Kathryn M. Zurek🇺🇸

    We consider the uncertainty in the arm length of an interferometer due to metric fluctuations from the quantum nature of gravity, proposing a concrete microscopic model of energy fluctuations in holographic degrees of freedom on the surface bounding a causally connected region of spacetime. In our model, fluctuations longitudinal to the beam direction accumulate in the infrared and feature strong long distance correlation in the transverse direction. This leads to a signal that could be observed in a gravitational wave interferometer. We connect the positional uncertainty principle arising from our calculations to the 't Hooft gravitational S-matrix.

    ↳ gr-qchep-phhep-thPLB(2021)·107 citations
33. 33*

    Dressed Power-law Inflation with Cuscuton

    Asuka Ito🇯🇵 · Aya Iyonaga🇯🇵 · Suro Kim🇯🇵 · Jiro Soda🇯🇵

    We study dressed inflation with a cuscuton and find a novel exact power-law solution. It is well known that the conventional power-law inflation is inconsistent with the Planck data. In contrast to this standard lore, we find that power-law inflation with a cuscuton can be reconciled with the Planck data. Moreover, we argue that the cuscuton generally ameliorates inflation models so that predictions are consistent with observations.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2019)·19 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.