Tue·Dec 21, 2021Tuesday·December 21, 2021

1. 01*

   Precision identified-hadron spectrum analysis for 5 TeV $\mathbf{p}$-$\mathbf{Pb}$ collisions -- Part I

   Thomas A. Trainor🇺🇸

   The $p$-Pb collision system occupies a unique position regarding physical interpretation of high-energy particle data. More-peripheral $p$-Pb is indistinguishable from $p$-$p$ collision while more-central $p$-Pb overlaps an interval of Pb-Pb centrality wherein it has been claimed that quark-gluon plasma (QGP) formation is achieved. One basis for such claims is certain features and centrality trends of identified-hadron (PID) $p_t$ spectra, including similarities between $p$-Pb and Pb-Pb spectra. In order to verify or falsify such claims it is essential that PID spectra for $p$-Pb collisions (as a control experiment) be understood in terms of fundamental QCD principles. This article (Part I of a two-part report) presents application of a two-component (soft + hard) model (TCM) to PID spectra from 5 TeV $p$-Pb collisions. Certain issues remaining from a preliminary PID TCM analysis (e.g. proton detection inefficiency) are resolved. Coefficients for TCM model functions previously assumed independent of $p$-Pb centrality are obtained directly from spectra. Jet-related spectrum hard components are precisely isolated and their shape evolution with centrality determined relative to a fixed TCM as reference. In Part II the TCM is further elaborated to describe varying spectrum hard components (and therefore entire spectra) within data statistical uncertainties. The completed PID TCM is then used to investigate properties of spectrum and yield ratios (e.g. $p/\pi$) and ${\bar{p}}_t$ data.

   hep-ph14 citations
2. 02*

   Axion-like Particle Searches at DarkQuest

   Nikita Blinov🇨🇦 · Elizabeth Kowalczyk🇺🇸 · Margaret Wynne🇺🇸

   Axion-like particles (ALPs) interacting with the Standard Model can be abundantly produced in proton beam fixed-target experiments. Looking for their displaced decays is therefore an effective search strategy for ALPs with a mass in the MeV to GeV range. Focusing on the benchmark models where the ALP interacts dominantly with photons or gluons, we show that the proposed DarkQuest experiment at Fermilab will be able to test parameter space which has been previously inaccessible. We pay particular attention to the self-consistency of gluon-coupled ALP production and decay calculations, which has been recently shown to be a problem in many existing predictions. We also apply these results to explore existing constraints in the ALP parameter space.

   hep-phhep-exJHEP(2022)·52 citations
3. 03*

   Muon and Electron $(g-2)$ Anomalies with Non-Holomorphic Interactions in MSSM

   Md. Isha Ali🇮🇳 · Manimala Chakraborti🇵🇱 · Utpal Chattopadhyay🇮🇳 · Samadrita Mukherjee🇮🇳

   The recent Fermilab muon $g-2$ result and the same for electron due to fine-structure constant measurement through ${}^{133}\mathrm{Cs}$ matter-wave interferometry are probed in relation to MSSM with non-holomorphic (NH) trilinear soft SUSY breaking terms, referred as NHSSM. Supersymmetric contributions to charged lepton $(g-2{)}_l$ can be enhanced via the new trilinear terms involving a wrong Higgs coupling with left and right-handed scalars. Unlike many MSSM based analyses, the model does not require a light electroweakino, or light sleptons, or unequal left and right slepton masses, or a very large higgsino mass parameter. The first part of the analysis involves $(g-2{)}_{\mu }$ constraint along with limits from Higgs mass, B-physics, collider data, direct detection of dark matter (DM) while focusing on a higgsino DM which is underabundant in nature. We then impose the constraint from electron $g-2$ where a large Yukawa threshold corrections (an outcome of NHSSM) and opposite signs of trilinear NH coefficients associated with $\mu$ and $e$ fields are used to satisfy the dual limits of $\Delta a_{\mu }$ and $\Delta a_e$ (where the latter comes with negative sign). Varying Yukawa threshold corrections further provide the necessary flavor-dependent enhancement of $\Delta a_e/m_e^2$ compared to that of $\Delta a_{\mu }/m_{\mu }^2$. A larger Yukawa threshold correction through $A_e^{\prime }$ for $y_e$ also takes away the direct proportionality of $a_e$ with respect to $\tan \beta$. With a finite intercept, $a_e$ becomes only an increasing function of $\tan \beta$. We identified the available parameter space in the two cases while also applying the ATLAS data on slepton pair production in the plane of slepton mass parameter and the mass of the lightest neutralino.

   hep-phEPJC(2023)·30 citations
4. 04*

   Widening the $U(1{)}_{L_{\mu }-L_{\tau }}$ $Z^{\prime }$ mass range for resolving the muon $g-2$ anomaly

   Yu Cheng🇨🇳 · Xiao-Gang He🇨🇳 · Jin Sun🇨🇳

   Exchanging a $Z^{\prime }$ gauge boson is a favored mechanism to solve the muon $(g-2{)}_{\mu }$ anomaly. Among such models the $Z^{\prime }$ from $U(1{)}_{L_{\mu }-L_{\tau }}$ gauge group has been extensively studied. In this model the same interaction addressing $(g-2{)}_{\mu }$, leads to an enhanced muon neutrino trident (MNT) process ${\nu }_{\mu }N\to {\nu }_{\mu }\mu \bar{\mu }N$ constraining the $Z^{\prime }$ mass to be less than a few hundred MeV. Many other $Z^{\prime }$ models face the same problem. It has long been realized that the coupling of $Z^{\prime }$ in the model can admit $(\bar{\mu }{\gamma }^{\mu }\tau +{\bar{\nu }}_{\mu }{\gamma }^{\mu }L{\nu }_{\tau })Z_{\mu }^{\prime }$ interaction which does not contribute to the MNT process. It can solve $(g-2{)}_{\mu }$ anomaly for a much wider $Z^{\prime }$ mass range. However this new interaction induces $\tau \to \mu {\bar{\nu }}_{\mu }{\nu }_{\tau }$ which rules out it as a solution to $(g-2{)}_{\mu }$ anomaly. Here we propose a mechanism by introducing type-II seesaw $SU(2{)}_L$ triplet scalars to evade constraints from all known data to allow a wide $Z^{\prime }$ mass range to solve the $(g-2{)}_{\mu }$ anomaly. This mechanism opens a new window for $Z^{\prime }$ physics.

   hep-phPLB(2022)·23 citations
5. 05*

   Prospects for detecting axionlike particles at the Coherent CAPTAIN-Mills experiment

   A.A. Aguilar-Arevalo🇲🇽 · D.S.M. Alves🇺🇸 · S. Biedron🇺🇸 · J. Boissevain🇺🇸 · M. Borrego🇺🇸 · L. Bugel🇺🇸 · M. Chavez-Estrada🇲🇽 · J.M. Conrad🇺🇸 · R.L. Cooper🇺🇸 · A. Diaz🇺🇸 · J.R. Distel🇺🇸 · J.C. D'Olivo🇲🇽 and 36 other authors

   We show results from the Coherent CAPTAIN Mills (CCM) 2019 engineering run which begin to constrain regions of parameter space for axion-like particles (ALPs) produced in electromagnetic particle showers in an 800 MeV proton beam dump, and further investigate the sensitivity of ongoing data-taking campaigns for the CCM200 upgraded detector. Based on beam-on background estimates from the engineering run, we make realistic extrapolations for background reduction based on expected shielding improvements, reduced beam width, and analysis-based techniques for background rejection. We obtain reach projections for two classes of signatures; ALPs coupled primarily to photons can be produced in the tungsten target via the Primakoff process, and then produce a gamma-ray signal in the Liquid Argon (LAr) CCM detector either via inverse Primakoff scattering or decay to a photon pair. ALPs with significant electron couplings have several additional production mechanisms (Compton scattering, $e^{+}{e}^{-}$ annihilation, ALP-bremsstrahlung) and detection modes (inverse Compton scattering, external $e^{+}{e}^{-}$ pair conversion, and decay to $e^{+}{e}^{-}$). In some regions, the constraint is marginally better than both astrophysical and terrestrial constraints. With the beginning of a three year run, CCM will be more sensitive to this parameter space by up to an order of magnitude for both ALP-photon and ALP-electron couplings. The CCM experiment will also have sensitivity to well-motivated parameter space of QCD axion models. It is only a recent realization that accelerator-based large volume liquid argon detectors designed for low energy coherent neutrino and dark matter scattering searches are also ideal for probing ALPs in the unexplored $\sim$MeV mass scale.

   hep-phhep-exPRD(2023)·46 citations
6. 06*

   Workshop on Tau Lepton Physics: $30^{\mathbf{th}}$ Anniversary

   Antonio Pich🇪🇸

   The first Workshop on Tau Lepton Physics took place at Orsay in 1990. The evolution of the field and some physics highlights are briefly described, following the presentations discussed at the fifteen $\tau$ workshops that have been held since then.

   hep-phhep-exSciPost Phys.Proc.(2025)·1 citation
7. 07*

   Bound-state formation, dissociation and decays of darkonium with potential non-relativistic Yukawa theory for scalar and pseudoscalar mediators

   Simone Biondini🇨🇭 · Vladyslav Shtabovenko🇩🇪

   Dark matter models with light mediators featuring sizable interactions among dark particles enjoy an increasing attention in the model building community due to the elegance with which they can potentially explain the scaling relations governing galactic halos and clusters of galaxies. In the present work we continue our study of such models using non-relativistic and potential non-relativistic effective field theories (NREFTs and pNREFTs) and explore the properties of a Yukawa-type model with scalar and pseudoscalar interactions between a low-energetic scalar mediator and heavy dark matter fermions. In particular, we make first steps towards the formulation of such theories at finite temperature by providing the thermal bound-state formation rate and the thermal break-up of bound states from the self-energies of the dark-pair fields, that interact with the thermal environment. We estimate numerically bound-state effects on the dark matter energy density, that provide up to a $35\%$ correction depending on the relative size of the model couplings.

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

   Reduction of Order and Transseries Structure of Radiation Reaction

   Robin Ekman🇬🇧

   The Landau-Lifshitz equation is obtained from the Lorentz-Abraham-Dirac equation through `reduction of order'. It is the first in a divergent series of approximations that, after resummation, eliminate runaway solutions. Using Borel plane and transseries analysis we explain why this is, and show that a non-perturbative formulation of reduction of order can retain runaway solutions. We also apply transseries analysis to solutions of the Lorentz-Abraham-Dirac equation, essentially treating them as expansions in both time and a coupling. Our results illustrate some aspects of such expansions under changes of variables and limits.

   hep-phhep-thphysics.plasm-phPRD(2022)·5 citations
9. 09*

   Seesaw mechanism in the R-parity violating supersymmetric standard model with the gauged flavor $\mathrm{U}(1{)}_X$ symmetry

   A. Hinata🇯🇵

   We study the seesaw mechanism in the supersymmetric standard model (SSM) with ${\mathbb{Z}}_3$ symmetry instead of the R-parity, so-called {\it Matter triality} ($M_3$). This Abelian discrete symmetry prohibits the baryon/lepton number violation operators at the non-renormalizable level, and the proton longevity is ensured. The lepton number violation term by the right-handed neutrino is only allowed under the symmetry, it plays a role of the Majorana mass after the right-handed sneutrino develops into the vacuum expectation value. The mass of the active neutrino is generated from the two contributions from the right-handed neutrino and the neutralino due to the R-parity violation. In this paper, we realize the neutrino mass and mixing angle in the SSM with matter triality which is embedded into the gauged flavor $\mathrm{U}(1{)}_X$ symmetry. In addition to the flavor ansatz, we derive the charge assignment to satisfy the anomaly cancellation conditions. Then, the model could predict the sterile neutrino with the mass below the soft SUSY breaking mass scale, and its mass and mixing angle are restricted by the search for the heavy neutral leptons.

   hep-phPTEP(2022)·0 citations
10. 10*

    Magnetic moments of the doubly charged axial-vector $T_{cc}^{++}$ states

    U. Ozdem🇹🇷

    Motivated by the discovery of the doubly-charmed state $T_{cc}^{+}$ and with the help of light-cone sum rules, the magnetic moments of possible $T_{cc}^{++}$ states are calculated. While calculating the magnetic moments of these states, these particles are considered in the molecular picture and they have $J^P=1^{+}$ quantum numbers. The magnetic moment results obtained for the $T_{cc}^{++}$ states are large due to the double electric charge. The results obtained in this study can be checked using other theoretical models. The magnetic moments of the hadrons reveal valuable knowledge about the size and the shape of the hadrons. Measurement of the magnetic moment of the $T_{cc}^{++}$ states in future experimental collaborations can be very useful to understanding substructure and identification the quantum numbers of these states.

    hep-phhep-exhep-latPRD(2022)·25 citations
11. 11*

    Probing dark gauge boson via Einstein-Cartan portal

    Cao H. Nam🇻🇳

    Einstein-Cartan gravity which is an alternative formulation of general relativity introduces new degrees of freedom contained in the torsion field which encodes the torsion feature of spacetime. Interestingly, the torsion field couples to all fermions through its axial-vector mode with a universal coupling $\eta =1/8$ which is possible to change under the quantum effects. We argue that Einstein-Cartan gravity provides a significant portal to probe $A^{\prime }$ dark gauge boson which resides in dark sector existing as an invisible world parallel to our own and couples to the standard model (SM) particles through only the kinetic mixing. For the (very) small kinetic mixing, searches for the $A^{\prime }$ from Drell-Yan processes are insensitive due to the suppressed production cross-section and the considerable SM backgrounds. However, through the mediation of torsion field the $pp$ collisions produce dark-sector fermions which would significantly produce the $A^{\prime }$ due to unsuppressed dark gauge coupling. We explore the potential production modes of the $A^{\prime }$ through bremsstrahlung off dark-sector fermion and the cascade decays. Einstein-Cartan gravity suggests the torsion mass $\gtrsim \mathcal{O}(4)$ TeV for $\eta$ varying around the classical value since the present scenarios would tend to produce the $A^{\prime }$ with the high boost and large missing transverse momentum from dark-sector fermions where the SM backgrounds are low. On the other hand, the $A^{\prime }$ search via Einstein-Cartan portal can reach even for the signal events to be not large and is also sensitive to the (very) small kinetic mixing as long as the decay channels of the $A^{\prime }$ to dark-sector particles are inaccessible.

    hep-phgr-qchep-thPRD(2022)·10 citations
12. 12*

    Azimuthal correlations of high transverse momentum jets at next-to-leading order in the parton branching method

    M. I. Abdulhamid🇪🇬 · M. A. Al-Mashad🇪🇬 · A. Bermudez Martinez🇩🇪 · G. Bonomelli🇮🇹 · I. Bubanja🇧🇪 · N. Crnkovic🇭🇷 · F. Colombina🇩🇪 · B. D'Anzi🇮🇹 · S. Cerci🇹🇷 · M. Davydov🇷🇺 · L.I. Estevez Banos🇩🇪 · N. Forzano🇮🇹 and 17 other authors

    The azimuthal correlation, $\Delta {\varphi }_{12}$, of high transverse momentum jets in pp collisions at $\sqrt{s}=13$ TeV is studied by applying PB-TMD distributions to NLO calculations via MCatNLO together with the PB-TMD parton shower. A very good description of the cross section as a function of $\Delta {\varphi }_{12}$ is observed. In the back-to-back region of $\Delta {\varphi }_{12}\to \pi$, a very good agreement is observed with the PB-TMD Set 2 distributions while significant deviations are obtained with the PB-TMD Set 1 distributions. Set 1 uses the evolution scale while Set 2 uses transverse momentum as an argument in ${\alpha }_s$, and the above observation therefore confirms the importance of an appropriate soft-gluon coupling in angular ordered parton evolution. The total uncertainties of the predictions are dominated by the scale uncertainties of the matrix element, while the uncertainties coming from the PB-TMDs and the corresponding PB-TMD shower are very small. The $\Delta {\varphi }_{12}$ measurements are also compared with predictions using MCatNLO together PYTHIA8, illustrating the importance of details of the parton shower evolution.

    hep-phEPJC(2022)·29 citations
13. 13*

    Fragmentation functions for gluon into $B_c$ or $B_c^{\ast }$ meson

    Xu-Chang Zheng🇨🇳 · Chao-Hsi Chang🇨🇳 · Xing-Gang Wu🇨🇳

    In the paper, we calculate the fragmentation functions for $g\to B_c$ and $g\to B_c^{\ast }$. The ultraviolet divergences in the calculation are removed through the renormalization of the operator definition of the fragmentation functions under the modified minimal subtraction scheme. We then obtain the fragmentation functions $D_{g\to B_c}(z,{\mu }_F)$ and $D_{g\to B_c^{\ast }}(z,{\mu }_F)$, which are presented as figures and fitting functions. The obtained fragmentation functions are complementary to the previous work on the next-to-leading order fragmentation functions for $\bar{b}\to B_c(B_c^{\ast })$ and $c\to B_c(B_c^{\ast })$.

    hep-phJHEP(2022)·23 citations
14. 14*

    Artificial neural network modelling of generalised parton distributions

    H. Dutrieux · O. Grocholski · H. Moutarde · P. Sznajder

    We discuss the use of machine learning techniques in effectively nonparametric modelling of generalised parton distributions (GPDs) in view of their future extraction from experimental data. Current parameterisations of GPDs suffer from model dependency that lessens their impact on phenomenology and brings unknown systematics to the estimation of quantities like Mellin moments. The new strategy presented in this study allows to describe GPDs in a way fulfilling theory-driven constraints, keeping model dependency to a minimum. Getting a better grip on the control of systematic effects, our work will help the GPD phenomenology to achieve its maturity in the precision era commenced by the new generation of experiments.

    hep-phEPJC(2022)·33 citations
15. 15*

    A global analysis of charmless two body hadronic decays for anti-triplet charmed baryons

    Fei Huang🇨🇳 · Zhi-Peng Xing🇨🇳 · Xiao-Gang He🇨🇳

    Recently Belle collaboration reported new measurements for the branching fractions with the first observing two processes of $\mathcal{B}({\Xi }_c^0\to \Lambda K_S^0)$, $\mathcal{B}({\Xi }_c^0\to {\Sigma }^0{K}_S^0)$ and updating data for $\mathcal{B}({\Xi }_c^0\to {\Sigma }^{+}{K}^{-})$. Combined with other known data on charmless two body decays of anti-triplet charmed baryons, a lot of information can be derived with the assistance of $SU(3)$ flavour symmetry. Using $SU(3)$ relations between different decay modes, we can give some predictions based on the new measurements which can be tested with the high luminosity experiments in the future. More interestingly, we find that a global fit is now possible with the addition of new Belle data. In general, there are 18 complex $SU(3)$ invariant amplitudes. We find that a scenario of all amplitudes being real can fit the data well with a ${\chi }^2/d.o.f$ only $0.773$. This indicates that neglecting the phases of the amplitudes is a reasonable assumption. When more data become available, one may be able to get more information for phases in the amplitudes. We give several comments on the feature of global fit regarding the branching fractions, relations between different decays, and decays involving $K^0$ and ${\bar{K}}^0$. Many of the unknown branching fractions and polarization asymmetry parameters of anti-triplet charmed baryon for charmless two body decays are predicted to be accessible by experiments at Belle, Belle~II, BES-III, and LHCb. The validity of $SU(3)$ for charmless two body hadronic decays can be more accurately tested.

    hep-phhep-exJHEP(2022)·29 citations
16. 16*

    Measuring the stability of fundamental constants with a network of clocks

    G. Barontini🇬🇧 · L. Blackburn🇬🇧 · V. Boyer🇬🇧 · F. Butuc-Mayer🇬🇧 · X. Calmet🇬🇧 · J. R. Crespo Lopez-Urrutia🇩🇪 · E. A. Curtis🇬🇧 · B. Darquie🇬🇧 · J. Dunningham🇬🇧 · N. J. Fitch🇬🇧 · E. M. Forgan🇬🇧 · K. Georgiou🇬🇧 and 32 other authors

    The detection of variations of fundamental constants of the Standard Model would provide us with compelling evidence of new physics, and could lift the veil on the nature of dark matter and dark energy. In this work, we discuss how a network of atomic and molecular clocks can be used to look for such variations with unprecedented sensitivity over a wide range of time scales. This is precisely the goal of the recently launched QSNET project: A network of clocks for measuring the stability of fundamental constants. QSNET will include state-of-the-art atomic clocks, but will also develop next-generation molecular and highly charged ion clocks with enhanced sensitivity to variations of fundamental constants. We describe the technological and scientific aims of QSNET and evaluate its expected performance. We show that in the range of parameters probed by QSNET, either we will discover new physics, or we will impose new constraints on violations of fundamental symmetries and a range of theories beyond the Standard Model, including dark matter and dark energy models.

    hep-phastro-ph.COgr-qchep-ex+1EPJ Quant.Technol.(2022)·55 citations
17. 17*

    The $\tau \to {\nu }_{\tau }\pi e^{+}{e}^{-}$ decay revisited

    Adolfo Guevara🇪🇸

    The recent results from Belle of the ${\tau }^{-}\to {\nu }_{\tau }{\pi }^{-}{e}^{+}{e}^{-}$ analysis has incentivated us to make a reanalysis of a former work where the Structure Dependent parts are obtained using Resonance Chiral Theory. Here we rely on the same theory accounting for effects that explicitly break such symmetry. A motivation is the involved $W\pi {\gamma }^{\star }$ vertex, utterly relevant in computing ${\tau }^{-}\to {\nu }_{\tau }{\pi }^{-}$ radiative corrections.

    hep-phRev.Mex.Fis.Suppl.(2022)·0 citations
18. 18*

    A novel viewpoint of Proton Decay

    Paul H Frampton🇮🇹

    We update the standard model d=6 operators of Weinberg (1979) using a modified notation which accommodates the bilepton extension of the standard model. This may lead to an enhancement of the proton lifetime by orders of magnitude due to mixing first-family with third-family quarks. By contrast, d=5 operators which can provide Majorana neutrino masses retain the family structure of their counterparts in the standard model.

    hep-phMod.Phys.Lett.A(2022)·2 citations
19. 19*

    Study of the hidden charm $D{\bar{D}}^{\ast }$ interactions in chiral effective field theory

    Hao Xu🇨🇳

    We study the chiral interactions of the hidden charm $D{\bar{D}}^{\ast }$ system within chiral effective field theory. Chiral Lagrangians are constructed by incorporating the chiral symmetry, heavy quark symmetry as well as proper charge conjugation properties of the heavy mesons. The interacting potentials of the $S$-wave $D{\bar{D}}^{\ast }$ are calculated up to second chiral order at 1-loop level, where complete two-pion exchange interactions are included. We further investigate the behaviors of the potentials in coordinate space, as well as their bound state properties. Our studies indicate that there exists a interacting strength ordering among considered four channels: $\text{str.}[0^{+}(1^{++})]>\text{str.}[0^{-}(1^{+-})]>\text{str.}[1^{+}(1^{+-})]>\text{str.}[1^{-}(1^{++})]$ where str. stands for the strength of the $D{\bar{D}}^{\ast }$ interaction. Moreover, we find that $X(3872)$ can be treated as a good candidate of $0^{+}(1^{++})$ molecular state. There also tends to form $0^{-}(1^{+-})$ and $1^{+}(1^{+-})$ molecular states and we expect the experiments to search for the predicted multi-structures around the $D{\bar{D}}^{\ast }$ mass region.

    hep-phhep-latnucl-thPRD(2022)·8 citations
20. 20*

    Dark Freeze-out Cogenesis

    Xiaoyong Chu🇦🇹 · Yanou Cui🇺🇸 · Josef Pradler🇦🇹 · Michael Shamma🇨🇦

    We propose a new mechanism where a multi-component dark sector generates the observed dark matter abundance and baryon asymmetry and thus addresses the coincidence between the two. The thermal freeze-out of dark matter annihilating into meta-stable dark partners sets the dark matter relic abundance while providing the out-of-equilibrium condition for baryogenesis. The meta-stable state triggers baryon asymmetry production by its decay well after the freeze-out and potentially induces a period of early matter domination before its decay. The dark matter and baryon abundances are related through number conservation within the dark sector (cogenesis). The "coincidence" is a natural outcome with GeV- to TeV-scale symmetric dark matter and the dark sector's interactions with the Standard Model quarks. We present a UV-complete model and explore its phenomenological predictions, including dark matter direct detection signals, LHC signatures of new massive particles with color charges and long-lived particles with displaced vertices, dark matter-induced nucleon conversions, (exotic) dark matter indirect detection signals, and effects on the cosmological matter power spectrum. As a side result, we provide a novel analytical treatment for dark sector freeze-out, which may prove useful in the study of related scenarios.

    hep-phastro-ph.COJHEP(2022)·15 citations
21. 21*

    Matchmakereft: automated tree-level and one-loop matching

    Adrian Carmona🇪🇸 · Achilleas Lazopoulos🇨🇭 · Pablo Olgoso🇪🇸 · Jose Santiago🇪🇸

    We introduce matchmakereft, a fully automated tool to compute the tree-level and one-loop matching of arbitrary models onto arbitrary effective theories. Matchmakereft performs an off-shell matching, using diagrammatic methods and the background field method when gauge theories are involved. The large redundancy inherent to the off-shell matching together with explicit gauge invariance offers a significant number of non-trivial checks of the results provided. These results are given in the physical basis but several intermediate results, including the matching in the Green basis before and after canonical normalization, are given for flexibility and the possibility of further cross-checks. As a non-trivial example we provide the complete matching in the Warsaw basis up to one loop of an extension of the Standard Model with a charge -1 vector-like lepton singlet. Matchmakereft has been built with generality, flexibility and efficiency in mind. These ingredients allow matchmakereft to have many applications beyond the matching between models and effective theories. Some of these applications include the one-loop renormalization of arbitrary theories (including the calculation of the one-loop renormalization group equations for arbitrary theories); the translation between different Green bases for a fixed effective theory or the check of (off-shell) linear independence of the operators in an effective theory. All these applications are performed in a fully automated way by matchmakereft.

    hep-phSciPost Phys.(2022)·166 citations
22. 22*

    Depletion of atmospheric neutrino fluxes from parton energy loss

    François Arleo🇫🇷 · Greg Jackson🇺🇸 · Stéphane Peigné🇫🇷

    The phenomenon of fully coherent energy loss (FCEL) in the collisions of protons on light ions affects the physics of cosmic ray air showers. As an illustration, we address two closely related observables: hadron production in forthcoming proton-oxygen collisions at the LHC, and the atmospheric neutrino fluxes induced by the semileptonic decays of hadrons produced in proton-air collisions. In both cases, a significant nuclear suppression due to FCEL is predicted. The conventional and prompt neutrino fluxes are suppressed by $\sim 10...25\%$ in their relevant neutrino energy ranges. Previous estimates of atmospheric neutrino fluxes should be scaled down accordingly to account for FCEL.

    hep-phastro-ph.HEPLB(2022)·5 citations
23. 23*

    Probing Leptogenesis with the Cosmological Collider

    Yanou Cui🇺🇸 · Zhong-Zhi Xianyu🇨🇳

    Leptogenesis is generally challenging to directly test due to the very high energy scales involved. In this work we propose a new probe for leptogenesis with cosmological collider physics. With the example of a cosmological Higgs collider, we demonstrate that during inflation leptogenesis models can produce detectable primordial non-Gaussianity with distinctive oscillatory patterns that encode information about the lepton-number violating couplings, the Majorana right-hand neutrino masses, and the CP phases, which are essential to leptogenesis.

    hep-phastro-ph.COhep-thPRL(2022)·76 citations
24. 24*

    Binary neutron star mergers within kaon condensation: GW170817

    Z. Sharifi🇮🇷 · M. Bigdeli🇮🇷 · D. Alvarez-Castillo🇵🇱 · E. Nasiri🇮🇷

    The equation of state (EoS) of neutron star (NS) matter is investigated considering kaon condensation. Moreover, the tidal parameters related to the components of binary neutron star mergers are determined and compared to the constraints of GW170817 imposed on these quantities. In this study, we employ the lowest-order constrained variational (LOCV) approach and utilize {AV6${}^{\prime }$, AV8${}^{\prime }$, and AV18 potentials} accompanied by the three nucleon interaction (TNI) {in order to consider the nucleon-nucleon interaction}. It is known that the existence of kaons in the core of NSs softens the EoS {and thus} lowers the value of maximum mass which is expected to be greater than 2 M${}_{\odot }$. Our results demonstrate that considering kaon condensation with a strangeness value, a${}_3$m${}_s$=-134 MeV satisfies the maximum mass constraint except for AV8${}^{\prime }$+TNI potential. However, the calculation of dimensionless tidal deformability shows that with the decrease of strangeness value, the neutron star gets less deformed.

    ↳ astro-ph.HEastro-ph.SRhep-phPhys.Scripta(2021)·4 citations
25. 25*

    $R^2$-gravity quark stars from perturbative QCD

    José C. Jiménez🇧🇷 · Juan M. Z. Pretel🇧🇷 · Eduardo S. Fraga🇧🇷 · Sergio E. Jorás🇧🇷 · Ribamar R. R. Reis🇧🇷

    We investigate the structure of quark stars in the framework of $f(R)=R+\alpha R^2$ gravity using an equation of state for cold quark matter obtained from perturbative QCD, parametrized only by the renormalization scale. We show that a considerably large range of the free parameter $\alpha$, within and even beyond the constraints previously reported in the literature, yield non-negligible modifications in the mass and radius of stars with large central mass densities. Besides, their stability against baryon evaporation is analyzed through the behavior of the associated total binding energies for which we show that these energies are slightly affected by the modified gravity term in the regime of high proper (baryon) masses.

    ↳ gr-qcastro-ph.HEhep-phJCAP(2022)·16 citations
26. 26*

    Gürsey, Groups & Fluids

    V.P. Nair🇺🇸

    Feza Gürsey was a brilliant physicist who loved symmetries and beautiful mathematical structures such as group theory and division algebras. In this centenary year, I give a brief review of some of his contributions and then zero-in on group theory and discuss how it can give us a new perspective on a centuries-old topic, namely, fluid dynamics, including new facets such as the chiral magnetic effect. \vskip .1in \noindent This is a slightly edited and enhanced version of a colloquium at the Middle East Technical University on December 9, 2021, which was organized in celebration of the centenary of Feza Gürsey. The video of the presentation can be accessed by following the link given at http://www.physics.metu.edu.tr/Department/FezaGursey2021 or by clicking https://www.youtube.com/watch?v=DstVVuOlqGk for direct access.

    ↳ physics.hist-phhep-phhep-thmath-ph+10 citations
27. 27*

    A New Picture of Cosmic String Evolution and Anisotropic Stochastic Gravitational-Wave Background

    Rong-Gen Cai🇨🇳 · Zong-Kuan Guo🇨🇳 · Jing Liu🇨🇳

    We investigate the anisotropies of the stochastic gravitational-wave background (SGWB) produced by cosmic strings associated with the spontaneous U(1) symmetry breaking of Grand Unified Theory, which happens at the onset of inflation. The string network evolution is determined by primordial fluctuations and never reaches the scaling regime. The string loops are inhomogeneously distributed in large scale regions, resulting in large anisotropies in the SGWB. We find that the angular power spectrum of SGWB anisotropies depends on frequency, which is testable in multiband observations of GWs. In particular, GWs from the cosmic strings can appropriately interpret the common-spectrum process reported by NANOGrav collaboration, and the angular power spectrum in the nanohertz band, $\mathtt{l}(\mathtt{l}+1)C_{\mathtt{l}}=5.6\times 10^{-2}$ at large scales, is expected to be detectable by pulsar timing array experiments in the near future.

    ↳ astro-ph.COgr-qchep-ph10 citations
28. 28*

    When cold, dense quarks in 1+1 and 3+1 dimensions are not a Fermi liquid

    Marton Lajer🇺🇸 · Robert M. Konik🇺🇸 · Robert D. Pisarski🇺🇸 · Alexei M. Tsvelik🇺🇸

    We analyze the behavior of quarks coupled to a $SU(N_c)$ gauge theory in 1+1 dimensions. In the limit of strong coupling, the model reduces to a Wess-Zumino-Novikov-Witten (WZNW) model. At nonzero density, excitations near the Fermi surface form a non-Fermi liquid. With $N_f$ flavors, the finite density of quarks reduce to a free $U(1)$ field, which governs fluctuations in baryon number, together with a WZNW $SU(N_f)$ nonlinear sigma model at level $N_c$, from the pion/kaon modes. We compute the singularity in the charge susceptibility at the Fermi surface and the attendant power law correlations. We suggest that this is relevant to the quarkyonic regime of cold, dense QCD in 3+1 dimensions, in the limit that the Fermi surface is covered by many small patches, and the theory is effectively one dimensional. In this regime the dominant excitations near the Fermi surface are not baryons, but gapless bosonic modes.

    ↳ hep-thcond-mat.str-elhep-phnucl-thPRD(2022)·9 citations
29. 29*

    Specific heat and its high-order moments in relativistic heavy-ion collisions from a multiphase transport model

    Ru-Xin Cao🇨🇳 · Song Zhang🇨🇳 · Yu-Gang Ma🇨🇳

    Energy dependence of specific heat extracted from temperature fluctuation of Au + Au collisions at $\sqrt{s_{NN}}$ = 7.7 GeV to 200 GeV was investigated by using a multiphase transport (AMPT) model. The results were compared with those from other models and some differences at low $\sqrt{s_{NN}}$ were found. To explain the above differences and describe the properties of the hot dense matter at low $\sqrt{s_{NN}}$, a new quantity $C_v^{\ast }$ was derived for describing specific heat in heavy-ion collisions. It was found that, by using $C_v^{\ast }$ together with its high order moments (skewness and kurtosis), thermal properties of the hot dense matter can be described and different thermal properties with or without parton process can be clearly distinguished. The proposed observable provides a way to learn the property of QCD matter % phase transition %along with critical point in heavy-ion collisions.

    ↳ nucl-thhep-phnucl-exPRC(2022)·13 citations
30. 30*

    First test of Lepton Flavor Universality in the charmed baryon decays ${\Omega }_c^0\to {\Omega }^{-}{\ell }^{+}{\nu }_{\ell }$ using data of the Belle experiment

    Belle Collaboration:Y. B. Li🇨🇳 · C. P. Shen🇨🇳 · I. Adachi🇯🇵 · H. Aihara🇯🇵 · S. Al Said🇸🇦 · D. M. Asner🇺🇸 · H. Atmacan🇺🇸 · T. Aushev🇷🇺 · R. Ayad🇸🇦 · V. Babu🇩🇪 · S. Bahinipati🇮🇳 · P. Behera🇮🇳 and 193 other authors

    We present the first observation of the ${\Omega }_c^0\to {\Omega }^{-}{\mu }^{+}{\nu }_{\mu }$ decay and present measurements of the branching fraction ratios of the ${\Omega }_c^0\to {\Omega }^{-}{\ell }^{+}{\nu }_{\ell }$ decays compared to the reference mode ${\Omega }_c^0\to {\Omega }^{-}{\pi }^{+}$, ($\ell =e$ or $\mu$). This analysis is based on 89.5 fb${}^{-1}$, 711 fb${}^{-1}$, and 121.1 fb${}^{-1}$ data samples collected with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider at the center-of-mass energies of 10.52 GeV, 10.58 GeV, and 10.86 GeV, respectively. The ${\Omega }_c^0$ signal yields are extracted by fitting $M_{{\Omega }^{-}{\ell }^{+}}$ and $M_{{\Omega }^{-}{\pi }^{+}}$ spectra. The branching fraction ratios $\mathcal{B}({\Omega }_c^0\to {\Omega }^{-}{e}^{+}{\nu }_e)/\mathcal{B}({\Omega }_c^0\to {\Omega }^{-}{\pi }^{+})$ and $\mathcal{B}({\Omega }_c^0\to {\Omega }^{-}{\mu }^{+}{\nu }_{\mu })/\mathcal{B}({\Omega }_c^0\to {\Omega }^{-}{\pi }^{+})$ are measured to be $1.98\pm 0.13(stat.)\pm 0.08(syst.)$ and $1.94\pm 0.18(stat.)\pm 0.10(syst.)$, respectively. The ratio of $\mathcal{B}({\Omega }_c^0\to {\Omega }^{-}{e}^{+}{\nu }_e)/\mathcal{B}({\Omega }_c^0\to {\Omega }^{-}{\mu }^{+}{\nu }_{\mu })$ is measured to be $1.02\pm 0.10(stat.)\pm 0.02(syst.)$, which is consistent with the expectation of lepton flavor universality.

    ↳ hep-exhep-phPRD(2022)·34 citations
31. 31*

    Bayesian WIMP detection with the Cherenkov Telescope Array

    Abhi Mangipudi🇦🇺 · Eric Thrane🇦🇺 · Csaba Balazs🇦🇺

    Over the past decades Bayesian methods have become increasingly popular in astronomy and physics as stochastic samplers have enabled efficient investigation of high-dimensional likelihood surfaces. In this work we develop a hierarchical Bayesian inference framework to detect the presence of dark matter annihilation events in data from the Cherenkov Telescope Array (CTA). Cosmic rays are weighted based on their measured sky position ${\hat{\Omega }}_m$ and energy $E_m$ in order to derive a posterior distribution for the dark matter's velocity averaged cross section $⟨\sigma v⟩$. The dark matter signal model and the astrophysical background model are cast as prior distributions for $({\hat{\Omega }}_m,E_m)$. The shape of these prior distributions can be fixed based on first-principle models; or one may adopt flexible priors to include theoretical uncertainty, for example, in the dark matter annihilation spectrum or the astrophysical distribution of sky location. We demonstrate the utility of this formalism using simulated data with a contribution from a scalar singlet dark-matter model. The sensitivity according to our method is comparable to previous estimates of the CTA sensitivity.

    ↳ astro-ph.HEhep-phJCAP(2022)·3 citations
32. 32*

    A background-free optically levitated charge sensor

    Nadav Priel🇺🇸 · Alexander Fieguth🇺🇸 · Charles P. Blakemore🇺🇸 · Emmett Hough🇺🇸 · Akio Kawasaki🇺🇸 · Denzal Martin🇺🇸 · Gautam Venugopalan🇺🇸 · Giorgio Gratta🇺🇸

    Optically levitated macroscopic objects are a powerful tool in the field of force sensing, owing to high sensitivity, absolute force calibration, environmental isolation and the advanced degree of control over their dynamics that have been achieved. However, limitations arise from the spurious forces caused by electrical polarization effects that, even for nominally neutral objects, affect the force sensing because of the interaction of dipole moments with gradients of external electric fields. In this paper we introduce a new technique to model and eliminate dipole moment interactions limiting the performance of sensors employing levitated objects. This process leads to the first noise-limited measurement with a sensitivity of $3.3\times 10^{-5}e$. As a demonstration, this is applied to the search for unknown charges of a magnitude much below that of an electron or for exceedingly small unbalances between electron and proton charges. The absence of remaining systematic biases, enables true discovery experiments, with sensitivities that are expected to improve as the system noise is brought down to or beyond the quantum limit. As a by-product of the technique, the electromagnetic properties of the levitated objects can also be measured on an individual basis.

    ↳ hep-exhep-phquant-ph3 citations
33. 33*

    Cosmological Standard Timers from Unstable Primordial Relics

    Yi-Fu Cai🇨🇳 · Chao Chen🇨🇳 · Qianhang Ding🇨🇳 · Yi Wang🇨🇳

    In this article we study a hypothetical possibility of tracking the evolution of our Universe by introducing a series of the so-called standard timers. Any unstable primordial relics generated in the very early Universe may serve as the standard timers, as they can evolve through the whole cosmological background until their end while their certain time-varying properties could be a possible timer by recording the amount of physical time elapsed since the very early moments. Accordingly, if one could observe these quantities at different redshifts, then a redshift-time relation of the cosmic history can be attained. To illustrate such a hypothetical possibility, we consider the primordial black hole bubbles as a concrete example and analyze the mass function inside a redshifted bubble by investigating the inverse problem of Hawking radiation. To complete the analyses theoretically, the mass distribution can serve as a calibration of the standard timers.

    ↳ astro-ph.COgr-qchep-phhep-thEPJC(2023)·16 citations
34. 34*

    Anisotropies in Cosmological 21 cm Background by Oscillons/I-balls of Ultra-light Axion-like Particle

    Masahiro Kawasaki🇯🇵 · Kazuyoshi Miyazaki🇯🇵 · Kai Murai🇯🇵 · Hiromasa Nakatsuka🇯🇵 · Eisuke Sonomoto🇯🇵

    Ultra-light axion-like particle (ULAP) with mass $m\sim 10^{-22}\mathrm{eV}$ has recently been attracting attention as a possible solution to the small-scale crisis. ULAP forms quasi-stable objects called oscillons/I-balls, which can survive up to a redshift $z\sim 10$ and affect the structure formation on a scale $\sim \mathcal{O}(0.1)\mathrm{Mpc}$ by amplifying the density fluctuations. We study the effect of oscillons on 21~cm anisotropies caused by neutral hydrogen in minihalos. It is found that this effect can be observed in a wide mass range by future observations such as Square Kilometer Array~(SKA) if the fraction of ULAP to the total dark matter density is $\mathcal{O}(0.01\text{–}0.1)$.

    ↳ astro-ph.COhep-phJCAP(2022)·9 citations
35. 35*

    The refractive index of the relic gravitons and the nHz band

    Massimo Giovannini🇨🇭

    If the refractive index of the relic gravitons increases during a conventional stage of inflationary evolution the spectral energy density is blue at intermediate frequencies above the fHz and then flattens out after a knee that is typically smaller than the mHz. We investigate here the conditions leading to a sufficiently large spectral energy density in the nHz range where some peculiar signatures observed with the pulsar timing arrays have been recently attributed to cosmic gravitons. If these potential evidences are combined with the most recent bounds provided by wide-band interferometers in the audio range (i.e. between few Hz and the kHz) the allowed regions of the parameter space are compatible with both determinations and also with all the other constraints associated with the background of relic gravitons produced during inflation. The present analysis suggests that the pulsar timing arrays are sensitive to the evolution of the refractive index during the early stages of the inflationary evolution. This physical interpretation of the preliminary empirical evidence is distinguishable from other perspectives since the high-frequency normalization, the blue spectral index and the tensor to scalar ratio cannot be independently assigned but are all related to the frequency of the knee that is ultimately determined by the competition between the rate of evolution of the refractive index and the slow-roll corrections.

    ↳ gr-qcastro-ph.COhep-phhep-thEPJC(2022)·5 citations
36. 36*

    Lessons for adaptive mesh refinement in numerical relativity

    Miren Radia🇬🇧 · Ulrich Sperhake🇬🇧 · Amelia Drew🇬🇧 · Katy Clough🇬🇧 · Pau Figueras🇬🇧 · Eugene A. Lim🇬🇧 · Justin L. Ripley🇬🇧 · Josu C. Aurrekoetxea🇬🇧 · Tiago França🇬🇧 · Thomas Helfer🇺🇸

    We demonstrate the flexibility and utility of the Berger-Rigoutsos Adaptive Mesh Refinement (AMR) algorithm used in the open-source numerical relativity code GRChombo for generating gravitational waveforms from binary black-hole inspirals, and for studying other problems involving non-trivial matter configurations. We show that GRChombo can produce high quality binary black-hole waveforms through a code comparison with the established numerical relativity code Lean. We also discuss some of the technical challenges involved in making use of full AMR (as opposed to, e.g. moving box mesh refinement), including the numerical effects caused by using various refinement criteria when regridding. We suggest several "rules of thumb" for when to use different tagging criteria for simulating a variety of physical phenomena. We demonstrate the use of these different criteria through example evolutions of a scalar field theory. Finally, we also review the current status and general capabilities of GRChombo.

    ↳ gr-qcastro-ph.HEhep-phClass.Quant.Grav.(2022)·80 citations
37. 37*

    An Operator Product Expansion for Form Factors III. Finite Coupling and Multi-Particle Contributions

    Amit Sever🇮🇱 · Alexander G. Tumanov🇩🇪 · Matthias Wilhelm🇩🇰

    Form factors in planar $\mathcal{N}=4$ super-Yang-Mills theory have a dual description in terms of periodic Wilson loops. This duality maps the multi-collinear expansion of the former to an operator product expansion of the latter. The coefficients of this expansion are decomposed in terms of several elementary building blocks and can be determined at finite 't Hooft coupling using bootstrap and integrability techniques. Some of these blocks are known from an analogous expansion of scattering amplitudes. In addition to these, the expansion for form factors includes a new type of building block, called {\it form factor transitions}, that encode information about the local operator. In the present paper, we consider the form factor of the chiral part of the stress-tensor supermultiplet. We bootstrap the corresponding form factor transitions of two-particle flux-tube states and use them to predict the leading term in the collinear expansion at finite coupling. The transitions we find can be expressed in terms of a quantity that previously appeared in a seemingly unrelated context, namely the octagon kernel. Lastly, we use a factorized ansatz to determine the multi-particle form factor transitions at finite coupling, which we use to predict the first subleading term in the collinear expansion. A perfect match is found between our predictions and the available perturbative data.

    ↳ hep-thhep-phJHEP(2022)·30 citations
38. 38*

    A first look at the function space for planar two-loop six-particle Feynman integrals

    Johannes Henn🇩🇪 · Tiziano Peraro🇮🇹 · Yingxuan Xu🇩🇪 · Yang Zhang🇨🇳

    Two-loop corrections to scattering amplitudes are crucial theoretical input for collider physics. Recent years have seen tremendous advances in computing Feynman integrals, scattering amplitudes, and cross sections for five-particle processes. In this paper, we initiate the study of the function space for planar two-loop six-particle processes. We study all genuine six-particle Feynman integrals, and derive the differential equations they satisfy on maximal cuts. Performing a leading singularity analysis in momentum space, and in Baikov representation, we find an integral basis that puts the differential equations into canonical form. The corresponding differential equation in the eight independent kinematic variables is derived with the finite-field reconstruction method and the symbol letters are identified. We identify the dual conformally invariant hexagon alphabet known from maximally supersymmetric Yang-Mills theory as a subset of our alphabet. This paper constitutes an important step in the analytic calculation of planar two-loop six-particle Feynman integrals.

    ↳ hep-thhep-phJHEP(2022)·31 citations
39. 39*

    Predictions for neutron stars from holographic nuclear matter

    Nicolas Kovensky🇫🇷 · Aaron Poole🇬🇧 · Andreas Schmitt🇬🇧

    We discuss masses, radii, and tidal deformabilities of neutron stars constructed from the holographic Witten-Sakai-Sugimoto model. Using the same model for crust and core of the star, we combine our theoretical results with the latest astrophysical data, thus deriving more stringent constraints than given by the data alone. For instance, our calculation predicts -- independent of the model parameters -- an upper limit for the maximal mass of the star of about 2.46 solar masses and a lower limit of the (dimensionless) tidal deformability of a 1.4-solar-mass star of about 277.

    ↳ astro-ph.HEhep-phhep-thnucl-thSciPost Phys.Proc.(2022)·11 citations
40. 40*

    Do cosmological observations allow a negative $\Lambda$?

    Anjan A. Sen🇮🇳 · Shahnawaz A. Adil🇮🇳 · Somasri Sen🇮🇳

    In view of the recent measurement of $H_0$ from HST and SH0ES team, we explore the possibility of existence of a negative cosmological constant (AdS vacua in the dark energy sector) in the Universe. In this regard, we consider quintessence fields on top of a negative cosmological constant and compare such construction with $\Lambda$CDM model using a different combination of CMB, SnIa, BAO and $H_0$ data. Various model comparison estimators show that quintessence models with a negative $\Lambda$ is either preferred over $\Lambda$CDM or performs equally as $\Lambda$CDM model. This suggests that the presence of a negative $\Lambda$ (AdS ground state) in our Universe, which can naturally arise in string theory, is consistent with cosmological observations.

    ↳ astro-ph.COgr-qchep-phhep-thMNRAS(2022)·101 citations
41. 41*

    How to assess the primordial origin of single gravitational-wave events with mass, spin, eccentricity, and deformability measurements

    Gabriele Franciolini🇮🇹 · Roberto Cotesta🇺🇸 · Nicholas Loutrel🇮🇹 · Emanuele Berti🇺🇸 · Paolo Pani🇮🇹 · Antonio Riotto🇨🇭

    A population of primordial black holes formed in the early Universe could contribute to at least a fraction of the black-hole merger events detectable by current and future gravitational-wave interferometers. With the ever-increasing number of detections, an important open problem is how to discriminate whether a given event is of primordial or astrophysical origin. We systematically present a comprehensive and interconnected list of discriminators that would allow us to rule out, or potentially claim, the primordial origin of a binary by measuring different parameters, including redshift, masses, spins, eccentricity, and tidal deformability. We estimate how accurately future detectors (such as the Einstein Telescope and LISA) could measure these quantities, and we quantify the constraining power of each discriminator for current interferometers. We apply this strategy to the GWTC-3 catalog of compact binary mergers. We show that current measurement uncertainties do not allow us to draw solid conclusions on the primordial origin of individual events, but this may become possible with next-generation ground-based detectors.

    ↳ astro-ph.COastro-ph.HEgr-qchep-ph+1PRD(2022)·73 citations
42. 42*

    Polychronic Tunneling: New Tunneling Processes Experiencing Euclidean and Lorentzian Evolution Simultaneously

    Naritaka Oshita🇯🇵 · Yutaro Shoji🇮🇱 · Masahide Yamaguchi🇯🇵

    We discuss new possible tunneling processes in the presence of gravity. We formulate quantum tunneling using the Wheeler-deWitt canonical quantization and the WKB approximation. The distinctive feature of our formulation is that it accommodates the coexistence of Euclidean and Lorentzian evolution. It opens up a new possibility of quantum tunneling; e.g. a bubble wall itself tunnels the potential barrier pulling the field nearby, where the wall region experiences the Euclidean evolution while the other regions experience the Lorentzian evolution simultaneously. We execute numerical analysis and find that such a process can have a much higher tunneling rate than that of the Coleman-De Luccia bounce. We also find that the new tunneling processes exist even in the decoupling regime of gravity and affect low energy phenomenology.

    ↳ hep-thastro-ph.COgr-qchep-phPRD(2023)·10 citations
43. 43*

    Quintessence and the Swampland: The parametrically controlled regime of moduli space

    Michele Cicoli🇮🇹 · Francesc Cunillera🇬🇧 · Antonio Padilla🇬🇧 · Francisco G. Pedro🇮🇹

    We provide evidence that slow roll is not possible in any parametrically controlled regime of the moduli space of string theory. This is proven in full generality in the asymptotic limit of the moduli space of type II and heterotic Calabi-Yau compactifications for the dilaton and any number of Kähler moduli. Our results suggest that in order to build quintessence into string theory one must work in the interior of moduli space where numerical, even if not parametric, control could still be achieved.

    ↳ hep-thastro-ph.COgr-qchep-phFortsch.Phys.(2022)·62 citations
44. 44*

    Convergence of hydrodynamics in rapidly spinning strongly coupled plasma

    Casey Cartwright🇺🇸 · Markus Garbiso Amano🇺🇸 · Matthias Kaminski🇺🇸 · Jorge Noronha🇺🇸 · Enrico Speranza🇺🇸

    We compute the radius of convergence of the linearized relativistic hydrodynamic expansion around a non-trivially rotating strongly coupled N=4 Super-Yang-Mills plasma. Our results show that the validity of hydrodynamics is sustained and can even get enhanced in a highly vortical quark-gluon plasma, such as the one produced in heavy-ion collisions. The hydrodynamic dispersion relations are computed using a rotating background that is an analytic solution of the ideal hydrodynamic equations of motion with non-vanishing angular momentum and large vorticity gradients, giving rise to a particular boost symmetry. Analytic equations for the transport coeffcients of the rotating plasma as a function of their values in a plasma at rest are given.

    ↳ hep-thhep-phnucl-thPRD(2023)·36 citations
45. 45*

    Quintessence and the Swampland: The numerically controlled regime of moduli space

    Michele Cicoli🇮🇹 · Francesc Cunillera🇬🇧 · Antonio Padilla🇬🇧 · Francisco G. Pedro🇮🇹

    We provide a detailed discussion of the main theoretical and phenomenological challenges of quintessence model building in any numerically controlled regime of the moduli space of string theory. We argue that a working quintessence model requires a leading order non-supersymmetric (near) Minkowski vacuum with an axionic flat direction. This axion, when lifted by subdominant non-perturbative effects, could drive hilltop quintessence only for highly tuned initial conditions and a very low inflationary scale. Our analysis has two important implications. Firstly, scenarios which are in agreement with the swampland conjectures, such as those that include runaways, or supersymmetric AdS and Minkowski vacua, cannot give rise to phenomenologically viable quintessence with full computational control. This raises doubts on the validity of the swampland dS conjecture since it would imply a strong tension between quantum gravity and observations. Secondly, if data should prefer dynamical dark energy, axion models based on alignment mechanisms look more promising than highly contrived hilltop scenarios.

    ↳ hep-thastro-ph.COgr-qchep-phFortsch.Phys.(2022)·52 citations
46. 46*

    Sensitivities on non-spinning and spinning primordial black hole dark matter with global 21 cm troughs

    Akash Kumar Saha🇮🇳 · Ranjan Laha🇮🇳

    Detection of the global 21 cm signal arising from neutral hydrogen can revolutionize our understanding of the standard evolution of the universe after recombination. In addition, it can also be an excellent probe of Dark Matter (DM). Among all the DM candidates, Primordial Black Holes (PBHs) are one of the most well-motivated. Hawking emission from low-mass PBHs can have substantial effect on the thermal and ionization history of the early universe, and that in turn can have an imprint on the global 21 cm signal. Recently EDGES has claimed a global 21 cm signal, though SARAS 3 has rejected that claim. In this work, we investigate the sensitivities on non-spinning and spinning PBHs arising from an EDGES-like measurement of the global 21 cm signal, and find that the sensitivities will be competitive with those arising from other astrophysical observables. We show that the sensitivities can be significantly strengthened depending on various uncertain astrophysical parameters. Besides, we also derive projections on the PBH density from the absorption trough expected during the Dark Ages. Our work shows that the near future unambiguous detection of the global 21 cm absorption troughs can be an excellent probe of PBH DM.

    ↳ astro-ph.COastro-ph.HEhep-phPRD(2022)·93 citations
47. 47*

    IR/UV Mixing, Towers of Species and Swampland Conjectures

    Alberto Castellano🇪🇸 · Alvaro Herráez🇫🇷 · Luis E. Ibáñez🇪🇸

    By applying the Covariant Entropy Bound (CEB) to an EFT in a box of size $1/{\Lambda }_{\text{IR}}$ one obtains that the UV and IR cut-offs of the EFT are necessarily correlated. We argue that in a theory of Quantum Gravity (QG) one should identify the UV cutoff with the `species scale', and give a general algorithm to calculate it in the case of multiple towers becoming light. One then obtains an upper bound on the characteristic mass scale of the tower in terms of the IR cut-off, given by $M_{\text{tower}}\lesssim ({\Lambda }_{\text{IR}}{)}^{2{\alpha }_D}$ in Planck units, with ${\alpha }_D=(D-2+p)/2p(D-1)$, where $p$ depends on the density of states. Identifying the IR cut-off with a (non-vanishing) curvature in AdS one reproduces the statement of the AdS Distance Conjecture (ADC), also giving an explicit lower bound for the $\alpha$ exponent. In particular, we find that the CEB implies $\alpha \ge 1/2$ in any dimension if there is a single KK tower, both in AdS and dS vacua. However values $\alpha <1/2$ are allowed if the particle tower is multiple or has a string component. We also consider the CKN constraint coming from avoiding gravitational collapse which further requires in general $\alpha \ge 1/D$ for the lightest tower. We analyse the case of the DGKT-CFI class of Type IIA orientifold models and show it has both particle and string towers below the species scale, so that a careful analysis of how the ADC is defined is needed. We find that this class of models obey but do not saturate the CEB. The UV/IR constraints found apply to both AdS and dS vacua. We comment on possible applications of these ideas to the dS Swampland conjecture as well as to the observed dS phase of the universe.

    ↳ hep-thhep-phJHEP(2022)·96 citations
48. 48*

    Decay of acoustic turbulence in two dimensions and implications for cosmological gravitational waves

    Jani Dahl🇫🇮 · Mark Hindmarsh🇫🇮 · Kari Rummukainen🇫🇮 · David Weir🇫🇮

    Gravitational waves from a phase transition associated with the generation of the masses of elementary particles are within the reach of future space-based detectors such as LISA. A key determinant of the resulting power spectrum, not previously studied, is the lifetime of the acoustic turbulence which follows. We study decaying acoustic turbulence using numerical simulations of a relativistic fluid in two dimensions. Working in the limit of non-relativistic bulk velocities, with an ultra-relativistic equation of state, we find that the energy spectrum evolves towards a self-similar broken power law, with a high-wavenumber behaviour of $k^{-2.08\pm 0.08}$, cut off at very high $k$ by the inverse width of the shock waves. Our model for the decay of acoustic turbulence can be extended to three dimensions using the universality of the high-$k$ power law and the evolution laws for the kinetic energy and the integral length scale. It is used to build an estimate for the gravitational wave power spectrum resulting from a collection of shock waves, as might be found in the aftermath of a strong first order phase transition in the early universe. The power spectrum has a peak wavenumber set by the initial length scale of the acoustic waves, and a new secondary scale at a lower wavenumber set by the integral scale after a Hubble time. Between these scales a distinctive new power law appears. Our results allow more accurate predictions of the gravitational wave power spectrum for a wide range of early universe phase transition scenarios.

    ↳ gr-qchep-phphysics.flu-dynPRD(2022)·44 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.