Thu·Sep 29, 2022Thursday·September 29, 2022

1. 01*

   Scalar and vector one-loop massive tadpole light-front gauge Feynman integrals

   Alfredo Takashi Suzuki🇺🇸 · Timothy Suzuki🇺🇸

   Light-front gauge is the most popular one to work with fundamental interactions, due to its characteristic maximum kinematical Poincare operators that it allows. However, it is also known to be one of the trickiest gauges one can work with for gauge theories, due to its singular nature. So, in terms of perturbative calculations in the light-front, there are only a few published and tabulated results for the pertinent Feynman integrals, mostly involving massless integrals. And the majority of the results given are only for the divergent parts of them and the complete closed form (or with the finite parts) of these are not known. In this manuscript, we use the technique of negative dimensional integration (NDIM) for the simplest of the one-loop massive integrals as a working bench for massive Feynman integrals in the light-front and show that novel results for the finite parts not known before are obtained.

   hep-phhep-thPRD(2022)·1 citation
2. 02*

   A two-component vector WIMP -- fermion FIMP dark matter model with an extended seesaw mechanism

   Francesco Costa🇩🇪 · Sarif Khan🇩🇪 · Jinsu Kim🇨🇭

   We consider an extension of the Standard Model that explains the neutrino masses and has a rich dark matter phenomenology. The model has two dark matter candidates, a vector WIMP and a fermion FIMP, and the sum of their relic densities matches the total dark matter abundance. We extensively study the dark matter production mechanisms and its connection with the neutrino sector, together with various bounds from present and future experiments. The extra scalar field in the model may induce a first-order phase transition in the early Universe. We study the production of stochastic gravitational waves associated with the first-order phase transition. We show that the phase transition can be strong, and thus the model may satisfy one of the necessary conditions for a successful electroweak baryogenesis. Detectability of the phase transition-associated gravitational waves is also discussed.

   hep-phastro-ph.COJHEP(2022)·27 citations
3. 03*

   Beam polarization effects on Z-boson pair production at electron-positron colliders: a full one-loop analysis

   Mehmet Demirci🇹🇷 · A. Baha Balantekin🇺🇸

   We present high-precision predictions for Z boson-pair production via electron-positron collisions by taking into account a full set of one-loop order scattering amplitudes, i.e., electroweak (EW) corrections together with soft and hard QED radiation. We provide a detailed numerical evaluation, from full EW corrections to pure QED corrections, specifically focusing on the effect of initial beam polarization on production rate. The left-right asymmetry and angular distributions are also presented. The radiative corrections are largely affected by initial beam polarizations. We get an improvement as around three times with completely polarized beams of $e_L^{-}$ and $e_R^{+}$. We find that the radiative corrections can sizably modify the production rate, typically yielding a total relative correction up to a few tens of a percent. This imply that the full EW corrections are required for $e^{-}{e}^{+}\to ZZ$ to match with percent level accuracy.

   hep-phPRD(2022)·6 citations
4. 04*

   A method to explore flavor symmetries of the 3HDM and their implications on lepton masses and mixing

   Bartosz Dziewit🇵🇱 · Marek Zralek🇵🇱 · Joris Vergeest🇵🇱 · Piotr Chaber🇵🇱

   We present a method to identify symmetry groups of the Yukawa sector of the three-Higgs-doublet model and to determine the implication that the symmetry has on the lepton masses and mixing. The method can accommodate different hypotheses about the group representation assignments, and thus support the exploration of candidate symmetry groups. For one particular representation selection scheme we apply the computer-implemented method to scan all discrete groups of order less than 1035. It can be proven that none of these groups defines a flavor symmetry that implies masses and neutrino mixing angles consistent with the experimental lepton data, although several cases are found that are partially or approximately consistent.

   hep-phSymmetry(2022)·1 citation
5. 05*

   One-loop calculations for $H\to f\bar{f}\gamma$ in the $U(1{)}_{B-L}$ extension for Standard Model

   Khiem Hong Phan (DuyTan Univ.)🇳🇱 · Anh Thu Nguyen (HCMUS)🇻🇳 · Dzung Tri Tran (HCMUS)🇻🇳

   In this paper, we present the calculations for $H\to f\bar{f}\gamma$ in the $U(1{)}_{B-L}$ extension for Standard Model. Analytic results for one-loop form factors in the decay process are expressed in terms of the scalar one-loop Passarino$-$Veltman functions in the conventions of {\tt LoopTools}. Therefore, the decay rates can be evaluated numerically by using this package. In phenomenological results, we show the differential decay rates with respect to invariant mass of fermion pair $m_{ff}$, new neutral gauge mass $M_{Z^{\prime }}$ and the coupling $g^{\prime }$ of $U(1{)}_{B-L}$ gauge group. We find that the contributions of the $U(1{)}_{B-L}$ extension for Standard Model are visible effects and they must be taken into account at future colliders.

   hep-ph1 citation
6. 06*

   Charmonium, $B_c$ and X(3872) Transport at the LHC

   Biaogang Wu🇺🇸 · Zhanduo Tang🇺🇸 · Min He🇨🇳 · Ralf Rapp🇺🇸

   We deploy a kinetic-rate equation to evaluate the transport of $J/\psi$, $\psi (2S)$, $B_c$ and X(3872) in ultra-relativistic heavy-ion collisions and compare their production yields to experimental data from the Large Hadron Collider. The rate equation has two main transport parameters, i.e., the equilibrium limit and reaction rate for each state. The temperature-dependent equilibrium limits include charm- and bottom-quark fugacities based on their initial production. The reaction rates for charmonia, bottomonia and $B_c$ rely on charm- and bottom-quark masses as well as binding energies from a thermodynamic $T$-matrix approach. For the X(3872) particle, its internal structure information is encoded in reaction rates and initial conditions in the hadronic phase via two different scenarios: a loosely bound hadronic molecule vs. a compact diquark-antidiquark tetraquark.

   hep-phnucl-thEPJ Web Conf.(2023)·3 citations
7. 07*

   Shape of the hot topological charge density spectral function

   M. Laine🇨🇭 · L. Niemi🇫🇮 · S. Procacci🇨🇭 · K. Rummukainen🇫🇮

   After motivating an interest in the shape of the topological charge density spectral function in hot Yang-Mills theories, we estimate it with the help of thermally averaged classical real-time simulations, for $N_{\mathrm{c}}=2,3$. After subtracting a perturbative contribution at large frequencies, we observe a non-trivial shape at small frequencies (a dip rather than a peak), interpolating smoothly towards the sphaleron rate at zero frequency. Possible frequency scales making an appearance in this shape are discussed. Implications for warm axion inflation and reheating, and for imaginary-time lattice measurements of the strong sphaleron rate, are recapitulated.

   hep-phhep-latJHEP(2022)·19 citations
8. 08*

   Gravitational waves and primordial black holes from chirality imbalanced QCD first-order phase transition with $\mathcal{P}$ and $\mathcal{C}\mathcal{P}$ violation

   Jingdong Shao🇨🇳 · Mei Huang🇨🇳

   The chirality imbalance in QCD is spontaneously induced by a repulsive axial-vector interaction from the instanton anti-instanton pairing at high temperature above the chiral phase transition, and vanishes at low temperature. The chiral chemical potential ${\mu }_5$ is in the same magnitude as estimated from the sphaleron transition. Phase transition of the chirality imbalance is always a first-order one in the early universe with $\mathcal{P}$ and $\mathcal{C}\mathcal{P}$ violation. The spectra of gravitational waves and the formation of the primordial black holes from this first-order phase transition is investigated in this work, and the effect of a strong magnetic field is also analyzed. The gravitational waves produced by chirality imbalance can be detected by LISA, Taiji and DECIGO, with the peak energy density locating in the range of $10^{-11}$ to $10^{-9}$ and the peak frequencies lying in the range of $10^{-5}$ Hz to $10^{-2}$ Hz. The spectrum with larger axial vector coupling strength and stronger magnetic field has higher peak energy density and lower peak frequency. According to this trend, the gravitational waves spectra might also be able to be detected by SKA, IPTA and EPTA. The Phase transition inverse duration $\beta /H_{\ast }$ calculated from the bounce solution is in the order of $10^4$, which is much higher than typical value $10-100$ from electroweak phase transitions. Based on the mechanism of postponement of the false vacuum decay, it is found that the formation of the primordial black hole is not favored because the phase transition completes in an extreme short time due to the large value of $\beta /H_{\ast }$ and thus the false vacuum energy density decays sharply.

   hep-phastro-ph.HEPRD(2023)·11 citations
9. 09*

   Initial state and approach to equilibrium

   Michał Spaliński🇵🇱

   A possible resolution of the early thermalisation puzzle is provided by the notion of far-from-equilibrium attractors which arise due to the specific kinematics of heavy-ion collisions. Attractors appear in a wide variety of dynamical models, and it is plausible that they also occur in QCD. The physical implications of these observations depend on how robust this effect is when typically made symmetry restrictions are relaxed. I briefly review this line of research and its perspectives.

   hep-phnucl-thActa Phys.Polon.Supp.(2023)·6 citations
10. 10*

    Spectrum of the S-wave fully-heavy tetraquark states

    Jie Zhang🇨🇳 · Jin-Bao Wang🇨🇳 · Gang Li🇨🇳 · Chun-Sheng An🇨🇳 · Cheng-Rong Deng🇨🇳 · Ju-Jun Xie🇨🇳

    In present work, spectrum of the $S$-wave fully-heavy tetraquark states $QQ\bar{Q}\bar{Q}$ ($Q=c,b$), i.e., $cc\bar{c}\bar{c}$, $bb\bar{b}\bar{b}$, $cc\bar{b}\bar{b}$/$bb\bar{c}\bar{c}$, $bc\bar{c}\bar{c}$/ $cc\bar{b}\bar{c}$, $bb\bar{c}\bar{b}$/$cb\bar{b}\bar{b}$, and $bc\bar{b}\bar{c}$ are systematically investigated within an nonrelativistic constituent quark model, in which the Instanton-induced and one-gluon-exchange interactions are taken into account as the residual spin-dependent hyperfine interaction. Our results show that the states with $cc\bar{c}\bar{c}$ and $bb\bar{b}\bar{b}$ components could be located around $6500$ MeV and $19200$ MeV, respectively. Based on our calculations, the new $X(6900)$ state observed by LHCb may be not a ground $cc\bar{c}\bar{c}$ tetraquark state, while it could be an orbitally or radially excited state of $cc\bar{c}\bar{c}$ system. On the other hand, the recently reported $X(6600)$ state by CMS and ATLAS can be explained as a ground $cc\bar{c}\bar{c}$ tetraquark state with spin-parity $J^{PC}=0^{++}$.

    hep-phEPJC(2022)·40 citations
11. 11*

    Exploring maverick top partner decays at the LHC

    Shivam Verma🇮🇳 · Sanjoy Biswas🇮🇳 · Anirban Chatterjee🇮🇳 · Joy Ganguly🇮🇳

    In this work, we have considered an extension of the standard model (SM) with a $SU(2{)}_L$ singlet vectorlike quark (VLQ) with electric charge $Q=+2/3$. The model also contains an additional local $U(1{)}_d$ symmetry group and the corresponding gauge boson is the dark photon. The VLQ is charged while all the SM particles are neutral under the new $U(1{)}_d$ gauge group. Even though in this model the VLQ possesses many properties qualitatively similar to that of the traditional top partner ($T_p$), there are some compelling differences as well. In particular, its branching ratio to the traditional modes ($T_p\to bW,tZ,th$) are suppressed which in turn helps to evade many of the existing bound, mainly coming from the LHC experiments. In an earlier work, such a VLQ is referred to as ``maverick top partner". It has been shown that the top partner in this model predominantly decays to a top quark and a dark photon/dark higgs pair ($T_p\to t{\gamma }_d,t{h}_d$) over a large region of the parameter space. The dark photon can be made invisible and consequently, it gives rise to the missing transverse energy ($/E_T$) signature at the LHC detector. We have mainly focused on the LHC signatures and future prospects of such top partners. In particular, we have studied the $t\bar{t}+/E_T$ and $t+/E_T$ signatures in the context of the LHC via pair and single productions of the top partner, respectively at 13 and 14 TeV LHC center of mass energies assuming that the dark photon either decays into an invisible mode or it is invisible at the length scale of the detector. We have shown that one can exclude $\sin {\theta }_L\sim 0.025$ (0.05) for $m_{{}_{T_p}}\le$ 2.0 (2.6) TeV at $\sqrt{s}=14$ TeV with an integrated luminosity of 3 ab${}^{-1}$ using the single top partner production channel.

    hep-phhep-exPRD(2023)·24 citations
12. 12*

    Boson-jet and jet-jet azimuthal correlations at high transverse momenta

    A.M. van Kampen🇧🇪 · A. Bermudez Martinez🇩🇪 · L.I. Estevez Banos🇩🇪 · F. Hautmann🇨🇭 · H. Jung🇩🇪 · M. Mendizabal🇩🇪 · K. Moral Figueroa🇬🇧 · S. Prestel🇸🇪 · S. Taheri Monfared🇩🇪 · Q. Wang🇩🇪 · K. Wichmann🇩🇪 · H. Yang🇩🇪

    We discuss our recent results on azimuthal distributions in vector boson + jets and multi-jet production at the LHC, obtained from the matching of next-to-leading order (NLO) perturbative matrix elements with transverse momentum dependent (TMD) parton branching. We present a comparative analysis of boson-jet and jet-jet correlations in the back to-back region, and a study of the theoretical systematic uncertainties associated with the matching scale in the cases of TMD and collinear parton showers.

    hep-phPoS(2022)·2 citations
13. 13*

    Comment on "Spin correlations in elastic $e^{+}{e}^{-}$ scattering in QED"

    Kort Beck🇺🇸 · Gabriel Jacobo🇺🇸

    In the previous work, "Spin correlations in elastic $e^{+}{e}^{-}$ scattering in QED" (Yongram, 2018), spin correlations for entangled electrons and positrons as emergent particles of electron-positron scattering (also known as Bhabha scattering) were calculated at tree level in QED. When trying to reproduce the author's work, we have found different results. In this work, we show the calculation for fully (initial and final polarized states) and partially (just final polarized states) polarized probability amplitudes for electron-positron scattering at all energies. While Yongram claims that violation of Clauser-Horne inequality (CHI) occurs at all energies for both mentioned cases, for fully polarized scattering we found violation of the CHI for speeds $\beta \gtrsim 0.696$, including the high energy limit, supporting the agreement between QED and foundations of quantum mechanics. However, for initially unpolarized particles we found no violation of the CHI.

    hep-phquant-phEur.Phys.J.D(2023)·7 citations
14. 14*

    Laboratory-frame tests of quantum entanglement in $H\to WW$

    J. A. Aguilar-Saavedra🇪🇸

    Quantum entanglement between the two $W$ bosons resulting from the decay of a Higgs boson may be investigated in the dilepton channel $H\to WW\to \ell \nu \ell \nu$ using laboratory-frame observables that only involve the charged leptons $\ell =e,\mu$. The dilepton invariant mass distribution, already measured by the ATLAS and CMS Collaborations at the LHC, can be used to observe the quantum entanglement of the $WW$ pair with a statistical sensitivity of $7\sigma$ with Run 2 data, and of $6\sigma$ when including theoretical systematics. As a by-product, the relation between $W$ rest frame (four-dimensional) angular distributions, $H\to WW$ decay amplitudes, and spin correlation coefficients, is written down.

    hep-phhep-exquant-phPRD(2023)·87 citations
15. 15*

    Strong-$CP$ with and without gravity

    Gia Dvali🇩🇪

    Conventionally, the strong-$CP$ problem is assumed to be a naturalness puzzle, with the axion solution sometimes viewed as an ad hoc fix. Gravity is either ignored or taken as a threat for the global Peccei-Quinn symmetry. We explain that the situation is fundamentally different. In gravity, axion is a matter of consistency imposed by the $S$-matrix: Each gauge sector must include axion with exact relaxation of the corresponding $\bar{\theta }$. We show that this favors an alternative and remarkably simple formulation of the axion, fully fixed by the gauge redundancy of QCD, without involvement of a global symmetry. The axion mechanism is a Higgs effect for the QCD $3$-form, ensuring that physics is independent of $\bar{\theta }$ to all orders in operator expansion. A near-future experimental detection of the neutron EDM will be an unambiguous signal of $CP$-violating physics beyond the Standard Model. The axion coupling is tied to the scale of gravity.

    hep-phgr-qchep-th54 citations
16. 16*

    The Type II Dirac Seesaw Portal to the mirror sector: Connecting neutrino masses and a solution to the strong CP problem

    Maximilian Berbig🇩🇪

    We present a version of the Type II Seesaw mechanism for parametrically small Dirac neutrino masses. Our model starts from an $\text{SU}(2{)}_{\text{L}}\otimes \text{SU}(2{)}^{\prime }\otimes \text{U}(1{)}_{\text{X}}$ gauge extension of the Standard Model involving a sector of mirror fermions. A bidoublet scalar with a very small vacuum expectation value connects the SM leptons with their mirror counterparts and we can identify the mirror neutrino with the right-handed neutrino. Similar to the conventional Type II Seesaw, our particle spectrum features singly- and doubly-charged scalars. The strong CP problem is solved by a discrete exchange symmetry between the two sectors that forces the contributions of quarks and mirror quarks to the strong CP phase to cancel each other. We discuss the low-energy phenomenology, comment on the cosmological implications of this scenario and indicate how to realize successful Dirac leptogenesis.

    hep-phPRD(2022)·13 citations
17. 17*

    Heavy-quark pair production at lepton colliders at NNNLO in QCD

    Xiang Chen🇨🇳 · Xin Guan🇨🇳 · Chuan-Qi He🇨🇳 · Xiao Liu🇬🇧 · Yan-Qing Ma🇨🇳

    We compute the total cross-section and invariant mass distribution for heavy-quark pair production in $e^{+}{e}^{-}$ annihilation at the next-to-next-to-next-to-leading order in QCD. The obtained results are expressed as piecewise functions defined by several deeply expanded power series, facilitating a rapid numerical evaluation. Utilizing top-pair production at a collision energy of 500 GeV as a benchmark, we observe a correction of approximately $0.1\%$ for the total cross-section and around $10\%$ for the majority of the invariant mass distribution range. These results play a crucial role in significantly reducing theoretical uncertainty: the scale dependence has been diminished to $0.06\%$ for the total cross-section and to $5\%$ for the invariant mass distribution. This reduction of uncertainty meets the stringent requirements of future lepton colliders.

    hep-phhep-exPRL(2024)·32 citations
18. 18*

    Asymptotically safe dark matter with gauged baryon number

    Jens Boos🇺🇸 · Christopher D. Carone🇺🇸 · Noah L. Donald🇺🇸 · Mikkie R. Musser🇺🇸

    We consider the inclusion of TeV-scale, fermionic dark matter in an asymptotically safe model of gauged baryon number that has been recently proposed [Phys. Rev. D 106, no. 3, 035015 (2022)]. The new gauge boson serves as a portal between the dark and the visible sectors. The range of the baryon number gauge coupling and the kinetic mixing between baryon number and hypercharge are constrained by the requirement that nontrivial ultraviolet fixed points are reached. We show that this asymptotically safe dark matter model can achieve the correct dark matter relic density while remaining consistent with direct detection bounds.

    hep-phPRD(2023)·21 citations
19. 19*

    Polarized gluon distribution in the proton from holographic light-front QCD

    Bheemsehan Gurjar🇮🇳 · Chandan Mondal🇨🇳 · Dipankar Chakrabarti🇮🇳

    We obtain the gluon parton distribution functions (PDFs) in the proton within the extended light-front holographic QCD framework, where the proton couples with the spin-two Pomeron in Anti-de Sitter space, together with constraints imposed by the Veneziano model. The gluon helicity asymmetry, after satisfying the perturbative QCD constraints at small and large longitudinal momentum regions, agrees with existing experimental measurements. The polarized gluon distribution is consistent with global analyses. We predict the gluon helicity contribution to the proton spin, $\Delta G=0.221_{-0.044}^{+0.056}$, close to the recent analysis with updated data sets and PHENIX measurement and the lattice QCD simulations. We subsequently present the unpolarized and polarized gluon generalized parton distributions in the proton.

    hep-phhep-thnucl-thPRD(2023)·12 citations
20. 20*

    Relic Challenges for Vector-Like Fermions as Connectors to a Dark Sector

    Alexandre Carvunis🇫🇷 · Navin McGinnis🇨🇦 · David E. Morrissey🇨🇦

    New dark sectors consisting of exotic fields that couple only very feebly to the Standard Model (SM) have strong theoretical motivation and may be relevant to explaining the abundance of dark matter (DM). An important question for such sectors is how they connect to the SM. For a dark sector with a new gauge interaction, a natural connection arises from heavy vector-like fermions charged under both the visible and dark gauge groups. The gauge charges of such fermions imply that one or more of them is stable in the absence of additional sources of dark symmetry breaking. A generic challenge for such connectors is that they can produce too much dark matter or interact too strongly with nuclei if they were ever thermalized in the early universe. In this paper we study this challenge in a simple connector theory consisting of new vector-like electroweak doublet and singlet fermions that also transform under the fundamental representation of a new (Abelian) gauge force, and we show that these connectors in their minimal form are almost always ruled out by existing direct DM searches. To address this challenge, we investigate two solutions. First, we study mitigating scattering on nuclei by introducing a Majorana mass term for the singlet. And second, we investigate a mixing with SM leptons that allows the connectors to decay while remaining consistent with cosmological tests and searches for charged lepton flavor violation. Both solutions rely on the presence of a dark Higgs field with a specific charge.

    hep-phJHEP(2023)·13 citations
21. 21*

    Symmetry energy in holographic QCD

    Lorenzo Bartolini🇨🇳 · Sven Bjarke Gudnason🇨🇳

    We study the symmetry energy (SE), an important quantity in nuclear physics, in the Witten-Sakai-Sugimoto model and in a much simpler hard-wall model of holographic QCD. The SE is the energy contribution to the nucleus due to having an unequal number of neutrons and protons. Using a homogeneous Ansatz representing smeared instantons and quantizing their isospin, we extract the SE and the proton fraction assuming charge neutrality and beta-equilibrium, using quantization of the isospin zeromode. We also show the equivalence between our method adapted from solitons and the usual way of the isospin controlled by a chemical potential at the holographic boundary. We find that the SE can be well described in the WSS model if we allow for a larger 't Hooft coupling and lower Kaluza-Klein scale than is normally used in phenomenological fits.

    hep-phhep-thnucl-thSciPost Phys.(2024)·19 citations
22. 22*

    One $\mu$ to rule them all: CMB spectral distortions can probe domain walls, cosmic strings and low scale phase transitions

    Nicklas Ramberg🇩🇪 · Wolfram Ratzinger🇩🇪 · Pedro Schwaller🇩🇪

    We present a new probe of purely gravitationally coupled sectors with large anisotropies. These anisotropies are damped via gravitational interactions with the baryon-photon fluid, which is heated up in the process. The injected heat causes measurable distortions of the cosmic microwave background spectrum. We give analytic estimates for the size of the distortions and outline how to calculate them from first principles. These methods are applied to anisotropies in the form of a domain wall/cosmic string network or caused by a first order phase transition or scalar field dynamics. We find that this method can potentially probe large regions of previously unconstrained parameter space and is very much complementary to up-coming searches of gravitational waves caused by such dark sectors.

    hep-phastro-ph.COJCAP(2023)·47 citations
23. 23*

    Analytic approach to axion-like-particle emission in core-collapse supernovae

    Ana Luisa Foguel🇧🇷 · Eduardo S. Fraga🇧🇷

    We investigate the impact of a presumed axion-like-particle (ALP) emission in a core-collapse supernova explosion on neutrino luminosities and mean energies employing a relatively simple analytic description. We compute the nuclear Bremsstrahlung and Primakoff axion luminosities as functions of the protoneutron star (PNS) parameters and discuss how the ALP luminosities compete with the neutrino emission, modifying the total PNS thermal energy dissipation. Our results are publicly available in the python package ARtiSANS, which can be used to compute the neutrino and axion observables for different choices of parameters.

    hep-phastro-ph.HEAstropart.Phys.(2023)·6 citations
24. 24*

    Inspiral gravitational waveforms from compact binary systems in Horndeski gravity

    Yurika Higashino🇯🇵 · Shinji Tsujikawa🇯🇵

    In a subclass of Horndeski theories with the speed of gravity equivalent to that of light, we study gravitational radiation emitted during the inspiral phase of compact binary systems. We compute the waveform of scalar perturbations under a post-Newtonian expansion of energy-momentum tensors of point-like particles that depend on a scalar field. This scalar mode not only gives rise to breathing and longitudinal polarizations of gravitational waves, but it is also responsible for scalar gravitational radiation in addition to energy loss associated with transverse and traceless tensor polarizations. We calculate the Fourier-transformed gravitational waveform of two tensor polarizations under a stationary phase approximation and show that the resulting waveform reduces to the one in a parametrized post-Einsteinian (ppE) formalism. The ppE parameters are directly related to a scalar charge in the Einstein frame, whose existence is crucial to allow the deviation from General Relativity (GR). We apply our general framework to several concrete theories and show that a new theory of spontaneous scalarization with a higher-order scalar kinetic term leaves interesting deviations from GR that can be probed by the observations of gravitational waves emitted from neutron star-black hole binaries. If the scalar mass exceeds the order of typical orbital frequencies $\omega \simeq 10^{-13}$~eV, which is the case for a recently proposed scalarized neutron star with a self-interacting potential, the gravitational waveform practically reduces to that in GR.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2023)·30 citations
25. 25*

    New Window on Matter-Antimatter Differences

    Xiaorong Zhou🇨🇳 · Stephen Lars Olsen🇨🇳

    Recent measurements of $CP$-related comparisons of the weak-interaction parameters that describe the decays of the ${\Xi }^{-}$ and the ${\bar{\Xi }}^{+}$ doubly strange hyperon and antihyperon are reviewed and their significance is discussed.

    ↳ hep-exhep-phInt.J.Mod.Phys.A(2022)·0 citations
26. 26*

    Light-Front Holography Model of the EMC Effect

    Dmitriy N. Kim🇺🇸 · Gerald A. Miller🇺🇸

    A new two-component model of the EMC effect based on Light-Front Holographic QCD (LFHQCD) is presented. The model suggests the EMC effect is the result of the nuclear potential breaking SU(6) symmetry. The model separates the $F_2^A$ nuclear structure function into two parts: a free contribution, involving the addition of proton and neutron structure functions weighted by the number of protons and neutrons respectively, and a nuclear/medium modified contribution that involves a universal function for all nuceli. Further, the model displays a connection with the correlation between the size of the EMC effect and the SRC pair density, $a_2$ - extracted from kinematic plateaus at around $x$ > 1 in inclusive quasi-elastic (QE) scattering.

    ↳ nucl-thhep-phnucl-exPRC(2022)·14 citations
27. 27*

    Scaling properties of background- and chiral-magnetically-driven charge separation: evidence for detection of the chiral magnetic effect in heavy ion collisions

    Roy A. Lacey (Depts. of Chemistry & Physics, Stony Brook University, NY, USA)🇺🇸

    The scaling properties of the $R_{{\Psi }_2}(\Delta S)$ correlator and the $\Delta \gamma$ correlator are used to investigate a possible chiral-magnetically-driven (CME) charge separation in $p$+Au, $d$+Au, Ru+Ru, Zr+Zr, and Au+Au collisions at ${\sqrt{s}}_{\mathrm{NN}}=200$~GeV, and in $p$+Pb (${\sqrt{s}}_{\mathrm{NN}}=5.02$~TeV) and Pb+Pb collisions at ${\sqrt{s}}_{\mathrm{NN}}=5.02$ and $2.76$~TeV. The results for $p$+Au, $d$+Au, $p$+Pb, and Pb+Pb collisions, show the $1/{\mathrm{N}}_{\mathrm{ch}}$ scaling for background-driven charge separation. However, the results for Au+Au, Ru+Ru, and Zr+Zr collisions show scaling violations which indicate a CME contribution in the presence of a large background. In mid-central collisions, the CME accounts for approximately 27\% of the signal + background in Au+Au and roughly a factor of two smaller for Ru+Ru and Zr+Zr, which show similar magnitudes.

    ↳ nucl-exhep-exhep-phnucl-thEPJ Web Conf.(2023)·0 citations
28. 28*

    A Detailed Analysis of the Special Points on $M-R$ Solutions of Hybrid (Twin) Stars

    Debashree Sen🇮🇳 · Naosad Alam🇮🇳 · Gargi Chaudhuri🇮🇳

    Hadron-quark phase transition in neutron star cores is achieved in the present work with the help of Maxwell construction. For the purpose we employ six different and well-known hadronic models for the pure hadronic phase. The quark phase is described with the MIT Bag model in which the density dependence of the bag pressure $B(\rho )$ is invoked for different asymptotic values ($B_{as}$) of $B(\rho )$. The resulting hybrid star (HS) configurations exhibit twin star characteristics and distinct special points (SPs) on the mass-radius diagram of the HSs irrespective of the transition densities and the value of $B_{as}$. We find that for any particular value of $B_{as}$, the mass corresponding to SP ($M_{SP}$) and the maximum mass ($M_{max}$) of the HSs, obtained with different hadronic models, follow a nearly linear (fitted) relationship where the slope is independent of the value of $B_{as}$. The $M_{SP}-M_{max}$ dependence of the HSs is found to be consistent with any hadronic equation of state (EoS) chosen to obtain the hybrid EoS and thus such relations can be considered as universal relations in the context of formation of SPs. A change in the value of $B_{as}$ shifts the position of the fitted line in the $M_{SP}-M_{max}$ plane, with the linearity, however, retained.

    ↳ nucl-thhep-phPRD(2022)·20 citations
29. 29*

    Primordial black holes and gravitational waves induced by exponential-tailed perturbations

    Katsuya T. Abe🇯🇵 · Ryoto Inui🇯🇵 · Yuichiro Tada🇯🇵 · Shuichiro Yokoyama🇯🇵

    Primordial black holes (PBHs) whose masses are in $\sim [10^{-15}{M}_{\odot },10^{-11}{M}_{\odot }]$ have been extensively studied as a candidate of whole dark matter (DM). One of the probes to test such a PBH-DM scenario is scalar-induced stochastic gravitational waves (GWs) accompanied with the enhanced primordial fluctuations to form the PBHs with frequency peaked in the mHz band being targeted by the LISA mission. In order to utilize the stochastic GWs for checking the PBH-DM scenario, it needs to exactly relate the PBH abundance and the amplitude of the GWs spectrum. Recently in Kitajima et al., the impact of the non-Gaussianity of the enhanced primordial curvature perturbations on the PBH abundance has been investigated based on the peak theory, and they found that a specific non-Gaussian feature called the exponential tail significantly increases the PBH abundance compared with the Gaussian case. In this work, we investigate the spectrum of the induced stochastic GWs associated with PBH DM in the exponential-tail case. In order to take into account the non-Gaussianity properly, we employ the diagrammatic approach for the calculation of the spectrum. We find that the amplitude of the stochastic GW spectrum is slightly lower than the one for the Gaussian case, but it can still be detectable with the LISA sensitivity. We also find that the non-Gaussian contribution can appear on the high-frequency side through their complicated momentum configurations. Although this feature emerges under the LISA sensitivity, it might be possible to obtain information about the non-Gaussianity from GW observation with a deeper sensitivity such as the DECIGO mission.

    ↳ astro-ph.COgr-qchep-phJCAP(2023)·62 citations
30. 30*

    Quantum state tomography, entanglement detection and Bell violation prospects in weak decays of massive particles

    Rachel Ashby-Pickering🇬🇧 · Alan J. Barr🇬🇧 · Agnieszka Wierzchucka🇬🇧

    A rather general method for determining the spin density matrix of a multi-particle system from angular decay data is presented. The method is based on a Bloch parameterisation of the $d$-dimensional generalised Gell-Mann representation of $\rho$ and exploits the associated Wigner- and Weyl-transforms on the sphere. Each parameter of a (possibly multipartite) spin density matrix can be measured from a simple average over an appropriate set of experimental angular decay distributions. The general procedures for both projective and non-projective decays are described, and the Wigner $P$ and $Q$ symbols calculated for the cases of spin-half, spin-one, and spin-3/2 systems. The methods are used to examine Monte Carlo simulations of $pp$ collisions for bipartite systems: $pp\to W^{+}{W}^{-}$, $pp\to ZZ$, $pp\to Z{W}^{+}$, $pp\to W^{+}\bar{t}$, $t\bar{t}$, and those from the Higgs boson decays $H\to W{W}^{\ast }$ and $H\to Z{Z}^{\ast }$. Measurements are proposed for entanglement detection and Bell inequality violation in bipartite systems.

    ↳ quant-phhep-exhep-phhep-thJHEP(2023)·127 citations
31. 31*

    Bounds from multi-messenger astronomy on the Super Heavy Dark Matter

    M. Deliyergiyev🇨🇭 · A. Del Popolo🇮🇹 · Morgan Le Delliou🇨🇳

    The purely gravitational evidence supporting the need for dark matter (DM) particles is compelling and based on Galactic to cosmological scale observations. Thus far, the promising weakly interacting massive particles scenarios have eluded detection, motivating alternative models for DM. We consider the scenarios involving the superheavy dark matter (SHDM) that potentially can be emitted by primordial black holes (PBHs) and can decay or annihilate into ultrahigh-energy (UHE) neutrinos and photons. The observation of a population of photons with energies $E\ge 10^{11}$ GeV would imply the existence of completely new physical phenomena, or shed some light on DM models. Only the ultra-high energy cosmic ray observatories have the capabilities to detect such UHE decay products via the measurements of UHE photon induced extensive air showers. Using the upper bound on the flux of UHE cosmic rays beyond $10^{11.3}$ GeV implying $J(>10^{11.3}\mathrm{GeV})<3.6\times 10^{-5}$ km${}^{-2}$sr${}^{-1}$y${}^{-1}$, at the $90\%$ C.L. reported by the Pierre Auger Observatory, we obtain global limits on the lifetime of the DM particles with masses $10^{15}\le M_X\le 10^{17}$ GeV. The constraints derived here are new and cover a region of the parameter space not yet explored. We compare our results with the projected constraints from future POEMMA and JEM-EUSO experiments, in order to quantify the improvement that will be obtained by these missions. Moreover, assuming that an epoch of early PBHs domination introduces a unique spectral break, $f_{\ast }$, in the gravitational wave spectrum, the frequency of which is related to the SHDM mass, we map potential probes and limits of the DM particles masses on the $f_{\ast }-M_X$ parameter space.

    ↳ astro-ph.HEastro-ph.COhep-phPRD(2022)·4 citations
32. 32*

    On fits to correlated and auto-correlated data

    Mattia Bruno🇮🇹 · Rainer Sommer🇩🇪

    Observables in particle physics and specifically in lattice QCD calculations are often extracted from fits. Standard ${\chi }^2$ tests require a reliable determination of the covariance matrix and its inverse from correlated and auto-correlated data, a challenging task often leading to close-to-singular estimates. These motivate modifications of the definition of ${\chi }^2$ such as uncorrelated fits. We show how the goodness-of-fit measured by their p-value can still be estimated robustly for a broad class of such fits.

    ↳ hep-latcond-mat.stat-mechhep-exhep-ph+1Comput.Phys.Commun.(2023)·43 citations
33. 33*

    Determination of ${\alpha }_s(m_Z)$ by the non-perturbative decoupling method

    Mattia Dalla Brida🇨🇭 · Roman Höllwieser🇩🇪 · Francesco Knechtli🇩🇪 · Tomasz Korzec🇩🇪 · Alessandro Nada🇮🇹 · Alberto Ramos🇪🇸 · Stefan Sint🇮🇪 · Rainer Sommer🇩🇪

    We present the details and first results of a new strategy for the determination of ${\alpha }_s(m_Z)$. By simultaneously decoupling 3 fictitious heavy quarks we establish a relation between the $\Lambda$-parameters of three-flavor QCD and pure gauge theory. Very precise recent results in the pure gauge theory can thus be leveraged to obtain the three-flavour $\Lambda$-parameter in units of a common decoupling scale. Connecting this scale to hadronic physics in 3-flavour QCD leads to our result in physical units, ${\Lambda }_{\overline{\mathrm{MS}}}^{(3)}=336(12)\mathrm{MeV}$, which translates to ${\alpha }_s(m_Z)=0.11823(84)$. This is compatible with both the FLAG average and the previous ALPHA result, with a comparable, yet still statistics dominated, error. This constitutes a highly non-trivial check, as the decoupling strategy is conceptually very different from the 3-flavour QCD step-scaling method, and so are their systematic errors. These include the uncertainties of the combined decoupling and continuum limits, which we discuss in some detail. We also quantify the correlation between both results, due to some common elements, such as the scale determination in physical units and the definition of the energy scale where we apply decoupling.

    ↳ hep-lathep-phEPJC(2022)·30 citations
34. 34*

    Optical circular polarization induced by axionlike particles in blazars

    Run-Min Yao🇨🇳 · Xiao-Jun Bi🇨🇳 · Jin-Wei Wang🇮🇹 · Peng-Fei Yin🇨🇳

    We propose that the interaction between the axionlike particles (ALPs) and photons can be a possible origin of optical circular polarization (CP) in blazars. Given that there is no definite detection of optical CP at $\sim 0.1\%$ level, a rough limit on ALP-photon coupling can be obtained, specifically $g_{a\gamma }\cdot B_{T0}\lesssim 7.9\times 10^{-12}{\mathrm{G}\cdot \mathrm{GeV}}^{-1}$ for $m_a\lesssim 10^{-13}\mathrm{eV}$, depending on the magnetic field configuration of the blazar jet. Obviously, for the blazar models with a larger magnetic field strength, such as hadronic radiation models, this constraint could be more stringent. We also perform a dedicated analysis of the tentative observations of optical CP in two blazars, namely 3C 66A and OJ 287, and we find that these observations could be explained by the ALP-photon mixing with $g_{a\gamma }\sim 10^{-11}{\mathrm{GeV}}^{-1}$. As an outlook, our analysis can be improved by further research on the radiation models of blazars and high-precision joint measurements of optical CP and linear polarization.

    ↳ astro-ph.HEhep-phPRD(2023)·9 citations
35. 35*

    Gradient flow step-scaling function for SU(3) with $N_f$ = 6 or 4 fundamental flavors

    Anna Hasenfratz🇺🇸 · Claudio Rebbi🇺🇸 · Oliver Witzel🇩🇪

    Nonperturbative determinations of the renormalization group (RG) $\beta$ function are crucial to understand properties of gauge-fermion systems at strong coupling and connect lattice simulations and the perturbative ultraviolet regime. Choosing well-understood, QCD-like systems with SU(3) gauge group and either six or four fundamental flavors, we investigate their step-scaling $\beta$ function. In both cases we push the simulations to the boundary of chiral symmetry breaking and study the regime $g_{GF}^2\lesssim 8.2$ with six, and $g_{GF}^2\lesssim 6.6$ with four flavors. We carefully consider the lattice discretization errors by comparing three different gradient flows (GF), and for each flow three operators to estimate the renormalized finite volume coupling. We also consider the tree level improvement of the coupling. Noteworthy outcome is that nonperturbatively determined $\beta$ functions run much slower than perturbatively predicted.

    ↳ hep-lathep-phPRD(2022)·9 citations
36. 36*

    Towards a nonperturbative construction of the $S$-matrix

    Brian Henning🇨🇭 · Hitoshi Murayama🇺🇸 · Francesco Riva🇨🇭 · Jedidiah O. Thompson🇺🇸 · Matthew T. Walters🇨🇭

    We present a nonperturbative recipe for directly computing the $S$-matrix in strongly-coupled QFTs. The method makes use of spectral data obtained in a Hamiltonian framework and can be applied to a wide range of theories, including potentially QCD. We demonstrate the utility of this prescription in the specific example of the 2+1d $O(N)$ model at large $N$, using energy eigenstates computed with Hamiltonian truncation to reproduce the full $2\to 2$ scattering amplitude for arbitrary (complex) center-of-mass energy.

    ↳ hep-thhep-lathep-phJHEP(2023)·16 citations
37. 37*

    The Interplay between the Dark Matter Axion and Primordial Black Holes

    Kratika Mazde🇮🇳 · Luca Visinelli🇨🇳

    If primordial black holes (PBHs) had come to dominate the energy density of the early Universe when oscillations in the axion field began, we show that the relic abundance and expected mass range of the QCD axion would be greatly modified. Since the QCD axion is a potential candidate for dark matter (DM), we refer to it as the DM axion. We predominantly explore PBHs in the mass range $(10^6-5\times 10^8)$g. We investigate the relation between the relic abundance of DM axions and the parameter space of PBHs. We numerically solve the set of Boltzmann equations, that governs the cosmological evolution during both radiation and PBH-dominated epochs, providing the bulk energy content of the early Universe. We further solve the equation of motion of the DM axion field to obtain its present abundance. Alongside non-relativistic production mechanisms, light QCD axions are generated from evaporating PBHs through the Hawking mechanism and could make up a fraction of the dark radiation (DR). If the QCD axion is ever discovered, it will give us insight into the early Universe and probe into the physics of the PBH-dominated era. We estimate the bounds on the model from DR axions produced via PBH evaporation and thermal decoupling, and we account for isocurvature bounds for the period of inflation where the Peccei-Quinn symmetry is broken. We assess the results obtained against the available CMB data and we comment on the forecasts from gravitational wave searches. We briefly state the consequences of PBH accretion and the uncertainties this may further add to cosmology and astroparticle physics modeling.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2023)·48 citations
38. 38*

    Vanishing of black hole tidal Love numbers from scattering amplitudes

    Mikhail M. Ivanov🇺🇸 · Zihan Zhou🇺🇸

    We extract the black hole (BH) static tidal deformability coefficients (Love numbers) and their spin-0 and spin-1 analogs by comparing on-shell amplitudes for fields to scatter off a spinning BH in the worldline effective field theory (EFT) and in general relativity (GR). We point out that the GR amplitudes due to tidal effects originate entirely from the BH potential region. Thus, they can be separated from gravitational non-linearities in the wave region, whose proper treatment requires higher order EFT loop calculations. In particular, the elastic scattering in the near field approximation is produced exclusively by tidal effects. We find this contribution to vanish identically, which implies that the static Love numbers of Kerr BHs are zero for all types of perturbations. We also reproduce the known behavior of scalar Love numbers for higher dimensional BHs. Our results are manifestly gauge-invariant and coordinate-independent, thereby providing a valuable consistency check for the commonly used off-shell methods.

    ↳ hep-thastro-ph.HEgr-qchep-phPRL(2023)·120 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.