Tue·Mar 22, 2022Tuesday·March 22, 2022

1. 01*

   Explaining the hints for lepton flavour universality violation with three $S_2$ leptoquark generations

   Andreas Crivellin🇨🇭 · Benjamin Fuks🇫🇷 · Luc Schnell🇩🇪

   Leptoquarks are prime candidates for explaining the intriguing hints for lepton flavour universality violation. In particular, the $SU(2{)}_L$ doublet of scalar leptoquarks $S_2$ is capable of providing an explanation for the tensions between the measurements and the Standard Model predictions in $(g-2{)}_{\mu }$, $b\to s{\ell }^{+}{\ell }^{-}$ and $b\to c\tau \nu$ processes, as well as in non-resonant di-electron production. However, in the minimal setup with a single leptoquark generation, a common explanation for all these issues is not possible as this would lead to unacceptably large charged lepton flavour violation. We therefore propose a model with three generations of $S_2$, each coupling exclusively to a single lepton flavour, \textit{i.e.}~a model extending the Standard Model particle content by an electroquark, a muoquark and a tauquark. We show that after taking into account other constraints, such as those originating from electroweak precision observables and $\Delta F=2$ processes, it is possible to provide a combined explanation for all these hints of lepton flavour universality violation. Moreover, we find that the presence of the tauquark can generate a dimension-six ${\mathcal{O}}_9^U$ operator via off-shell photon penguin diagrams, which, together with the muoquark contribution, further improves the global fit to $b\to s{\ell }^{+}{\ell }^{-}$ data.

   hep-phhep-exnucl-exnucl-thJHEP(2022)·42 citations
2. 02*

   CP violation and flavor invariants in the seesaw effective field theory

   Bingrong Yu🇨🇳 · Shun Zhou🇨🇳

   In this paper, we systematically study the algebraic structure of the ring of the flavor invariants and the sources of CP violation in the seesaw effective field theory (SEFT), which is obtained by integrating out heavy Majorana neutrinos in the type-I seesaw model at the tree level and thus includes the dimension-five Weinberg operator and one dimension-six operator. For the first time, we calculate the Hilbert series and explicitly construct all the primary flavor invariants in the SEFT. We show that all the physical parameters can be extracted using the primary invariants and any CP-violating observable can be expressed as the linear combination of CP-odd flavor invariants. The calculation of the Hilbert series shows that there is an equal number of primary flavor invariants in the SEFT and in the full seesaw model, which reveals the intimate connection between the flavor space of the SEFT and that of its ultraviolet theory. A proper matching procedure of the flavor invariants is accomplished between the SEFT and the full seesaw model, through which one can establish a direct link between the CP asymmetries in leptogenesis and those in low-energy neutrino oscillations.

   hep-phhep-thJHEP(2022)·30 citations
3. 03*

   A Comprehensive Study of Energy Dependence of Particle Ratios in $pp$ Collisions from SPS to LHC Energies

   A.M.Khan🇨🇳 · M.U.Ashraf🇵🇰 · Junaid Tariq🇵🇰 · Anwarzada🇵🇰 · Ijaz Ahmed🇵🇰

   A comprehensive study has been performed to estimate the kaon to pion ($K^{\pm }$/${\pi }^{\pm }$) yield ratio and total kaon to total pion ($K$/$\pi$) yield ratio as a function of centre of mass energy in $pp$ collisions at different energies i.e., \sqrts~= 6.3, 17.3, 62.4, 200, 900 GeV, 2.76 TeV, 7 TeV, 13 TeV and 14 TeV using EPOS1.99, EPOS-LHC, HIJING, QGSJETII-03 and Sibyll2.3d model simulations. NA61/SHINE experiment reported that $K^{+}/{\pi }^{+}$ yield ratio exhibits rapid changes at the SPS energy range. A horn like structure appears in $K/\pi$ yield ratio as a function of collision energy. Significant presence of horn in $K^{+}$/${\pi }^{+}$ and $K^{-}$/${\pi }^{-}$ yield ratio is suggested by experimental data at lower energies, which is confirmed by HIJING and EPOS-LHC models. A smooth increase in $K/\pi$ yield ratio is also seen at higher energies. The model simulations predict similar increase in yield ratio with increasing energies. On the basis of previous available measurements, we also study model predictions of these yield ratios at \sqrts~= 13 and 14 TeV where no data is available. Almost all models suggest a saturation in the yield ratio within statistical fluctuations at these energies except EPOS1.99 and QGSJETII-03 which slightly over predict the yield ratio. These systematic comparisons are helpful to apply possible constraints on various hadronic event generators to significantly improve the predictions of Standard Model physics as well as for the understanding of underlying physics mechanisms in high energy collisions.

   hep-phEur.Phys.J.Plus(2022)·2 citations
4. 04*

   Quarkonium polarization in Pb+Pb collisions in the improved color evaporation model

   Vincent Cheung🇺🇸 · Ramona Vogt🇺🇸

   We apply our calculation of direct $J/\psi$ production in the improved color evaporation mode at $\mathcal{O}({\alpha }_s^3)$ in collinear factorization to Pb+Pb collisions. The cold nuclear matter effects of nuclear modifications of the parton densities and intrinsic transverse momentum broadening are included. We find that the polarization is independent of these effects. Our calculations are compared to the Pb+Pb polarization parameters extracted by the ALICE Collaboration at $\sqrt{s_{NN}}=5.02$ TeV.

   hep-phPRC(2022)·10 citations
5. 05*

   Soft Pomeron in the Colour Glass Condensate approach

   Carlos Contreras (UTFSM)🇨🇱 · Eugene Levin (Tel Aviv U./UTFSM)🇮🇱 · Michael Sanhueza (UTFSM)🇨🇱

   In this paper we suggest a new approach to the structure of the soft Pomeron: based on the $t$-channel unitarity, we expressed the exchange of the soft Pomeron through the interaction of the dipole of small size of the order of $1/Q_s(Y)$ ($Q_s(Y)$ is the saturation momentum) with the hadrons. Therefore, it is shown that the typical distances in soft processes are small $r\sim 1/Q_s\text{Lb}\text{h}Y\text{Rb}$, where $Y=lns$. The saturation momentum, which determines the energy dependence of the scattering amplitude is proportional to $Q_s^2\text{Lb}\text{h}Y\text{Rb}\propto \exp \text{Lb}\text{h}\lambda Y\text{Rb}$, with $\lambda \approx 0.2$, and this behaviour is in perfect agreement with phenomenological Donnachie-Landshoff Pomeron. We demonstrate that the saturation models could describe the experimental data for ${\sigma }_{tot},{\sigma }_{el},{\sigma }_{diff}$ and $B_{el}$. Hence our approach is a good first approximation to start discussion of the soft processes in CGC approach on the solid theoretical basis.

   hep-phPRD(2022)·4 citations
6. 06*

   Revisiting the transition ${\Xi }_{cc}^{+}\to {\Xi }_c^{{(}^{\prime })+}$ to understand the data from LHCb

   Hong-Wei Ke🇨🇳 · Xue-Qian Li🇨🇳

   The LHCb collaboration newly measured the decay rate of doubly charmed baryon ${\Xi }_{cc}^{++}\to {\Xi }^{{}^{\prime }+}{\pi }^{+}$ and a ratio of its branching fraction with respect to that of the decay ${\Xi }_{cc}^{++}\to {\Xi }^{+}{\pi }^{+}$ is reported as $1.41\pm 0.17\pm 0.10$. This result conflicts with the theoretical predictions made by several groups. In our previous work, following the prescription given in early literature where the $us$ diquark in ${\Xi }_c^{+}$ is assumed to be a scalar whereas in ${\Xi }_c^{{}^{\prime }+}$ is a vector i.e. the spin-flavor structure of ${\Xi }_c^{+}$ is $[us{]}_{0}c$ and that of ${\Xi }_c^{{}^{\prime }+}$ is $[us{]}_{1}c$, we studied the case of ${\Xi }_{cc}^{++}\to {\Xi }^{{(}^{\prime })+}$ with the light front quark model. Numerically we obtained $\Gamma ({\Xi }_{cc}^{++}\to {\Xi }^{{}^{\prime }+}{\pi }^{+})/\Gamma ({\Xi }_{cc}^{++}\to {\Xi }^{+}{\pi }^{+})=0.56\pm 0.18$ which is about half of the data. While abandoning the presupposition, we suppose the spin-flavor structure of $us$ in ${\Xi }_c^{+}$ may be a mixture of scalar and vector, namely the spin-flavor function of ${\Xi }_c^{+}$ could be $\cos \theta [us{]}_0[c]+\sin \theta [us{]}_1[c]$. An alternative combination $-\sin \theta [us{]}_0[c]+\cos \theta [us{]}_1[c]$ would correspond to ${\Xi }_c^{{}^{\prime }+}$. Introducing the mixing mechanism the ratio $\Gamma ({\Xi }_{cc}^{++}\to {\Xi }^{{}^{\prime }+}{\pi }^{+})/\Gamma ({\Xi }_{cc}^{++}\to {\Xi }^{+}{\pi }^{+})$ depends on the mixing angle $\theta$. With the mixing scenario, the theoretical prediction on the ratio between the transition rate of ${\Xi }_{cc}^{+}\to {\Xi }_c^{{}^{\prime }+}$ and that of ${\Xi }_{cc}^{+}\to {\Xi }_c^{+}$ can coincide with the data as long as $\theta =16.27^{\circ }\pm 2.30^{\circ }$ or $85.54^{\circ }\pm 2.30^{\circ }$ is set. Definitely, more precise measurements on other decay portals of ${\Xi }_{cc}^{+}$ are badly needed for testing the mixing mechanism and further determining the mixing angle.

   hep-phhep-exPRD(2022)·20 citations
7. 07*

   Number-of-constituent-quark scaling of elliptic flow: a quantitative study

   M. Wang🇨🇳 · J.Q. Tao🇨🇳 · H. Zheng🇨🇳 · W.C. Zhang🇨🇳 · L.L. Zhu🇨🇳 · A. Bonasera🇺🇸

   The number-of-constituent-quark (NCQ) scaling behavior of the elliptic flow of identified particles produced in A+A collisions is studied quantitatively using an empirical function that fits the experimental $v_2$ data available from the RHIC and LHC. The most common approach for NCQ scaling involves (1) doing a scaling of the experimental $v_2$ data of an identified particle with its NCQ, (2) doing the same to its transverse momentum or energy, then (3) combining all the scaled data and identifying the NCQ behavior by intuitively looking (since the measured experimental data are discrete). We define two variables $(d_1,d_2)$ to describe NCQ scaling quantitatively and simultaneously, and identify the approximate region where the NCQ scaling holds. This approach could be applied to study NCQ or other scaling phenomena in future experiments.

   hep-phNucl.Sci.Tech.(2022)·27 citations
8. 08*

   Helicity amplitudes without gauge cancellation for electroweak processes

   Junmou Chen🇨🇳 · Kaoru Hagiwara🇯🇵 · Junichi Kanzaki🇯🇵 · Kentarou Mawatari🇯🇵

   In the 5-component representation of weak bosons, the first four components make a Lorentz four vector, representing the transverse and longitudinal polarizations excluding the scalar component of the weak bosons, whereas its fifth component corresponds to the Goldstone boson. We obtain the $5\times 5$ component propagators of off-shell weak bosons, proposed previously and named after the Goldstone boson equivalence theorem, by starting from the unitary-gauge representation of the tree-level scattering amplitudes, and by applying the BRST (Becchi--Rouet--Stora--Tyutin) identities to the two sub-amplitudes connected by each off-shell weak-boson line. By replacing all weak boson vertices with those among the off-shell 5-component wavefunctions, we arrive at the expression of the electroweak scattering amplitudes, where the magnitude of each Feynman amplitude has the correct on-shell limits for all internal propagators, and hence with no artificial gauge cancellation among diagrams. Although our derivation is limited to the tree-level only, it allows us to study the properties of each Feynman amplitude separately, and then learn how they interfere in the full amplitudes. We implement the 5-component weak boson propagators and their vertices in the numerical helicity amplitude calculation code HELAS (Helicity Amplitude Subroutines), so that an automatic amplitude generation program such as MadGraph can generate the scattering amplitudes without gauge cancellation. We present results for several high-energy scattering processes where subtle gauge-theory cancellation among diagrams takes place in all the other known approaches.

   hep-phEPJC(2023)·18 citations
9. 09*

   One-loop electroweak radiative corrections to polarized Møller scattering

   S.G. Bondarenko (1)🇷🇺 · L.V. Kalinovskaya (2)🇷🇺 · L.A. Rumyantsev (2)🇷🇺 · V.L. Yermolchyk (2,3) ((1) Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, 141980 Russia, (2) Dzhelepov Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, Dubna, 141980 Russia, (3) Institute for Nuclear Problems, Belarusian State University, Minsk, 220006 Belarus)🇷🇺

   This work is devoted to a theoretical description of polarized Møller scattering. Complete one-loop electroweak radiative corrections are calculated in the helicity amplitude approach with allowance for the exact dependence on the muon mass. Numerical results are presented for integrated unpolarized and polarized cross sections as well as angular differential distributions. Calculations are performed using ReneSANCe Monte Carlo generator and MCSANC Monte Carlo integrator.

   hep-phJETP Lett.(2022)·8 citations
10. 10*

    Particle production at large $p_T$ in Xe+Xe collisions with jet quenching using the higher twist approach

    Qing Zhang🇨🇳 · Wei Dai🇨🇳 · Lei Wang🇨🇳 · Ben-Wei Zhang🇨🇳 · Enke Wang🇨🇳

    The production of ${\pi }^0$, $\eta$, and $\varphi$ in the most central (0%-5%) Xe+Xe collisions at $\sqrt{s_{NN}}$ = 5.44 TeV is investigated in the framework of the perturbative QCD (pQCD) improved parton model at an accuracy of next-to-leading order (NLO). The jet quenching effect is effectively incorporated by medium-modified fragmentation functions via the higher-twist approach. Predictions of the nuclear modification factors of ${\pi }^0$, $\eta$, and $\varphi$ as functions of the transverse momentum $p_{\mathrm{T}}$ are made with the jet transport parameter ${\hat{q}}_0$, which is extracted from the available experimental data of charged hadrons provided by ALICE and CMS. The particle ratios $\eta /{\pi }^0,\varphi /{\pi }^0$ as functions of $p_{\mathrm{T}}$ in Xe+Xe collisions at $\sqrt{s_{NN}}$ = 5.44 TeV as well as in 0%-5% Pb+Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV are also presented. The numerical simulations of the scaled ratios of charged hadron production in the Xe+Xe 5.44 TeV system over those in the Pb+Pb 5.02 TeV system give a good description of the CMS data, and the scaled ratios of ${\pi }^0$, $\eta$, and $\varphi$ production coincide with the curve of charged hadron production.

    hep-phnucl-thCPC(2022)·7 citations
11. 11*

    Snowmass White Paper: Beyond the Standard Model effects on Neutrino Flavor

    C. A. Argüelles🇺🇸 · G. Barenboim🇪🇸 · M. Bustamante🇩🇰 · P. Coloma🇪🇸 · P. B. Denton🇺🇸 · I. Esteban🇺🇸 · Y. Farzan🇮🇷 · E. Fernández Martínez🇪🇸 · D. V. Forero🇨🇴 · A. M. Gago🇵🇪 · T. Katori🇬🇧 · R. Lehnert🇺🇸 and 14 other authors

    Neutrinos are one of the most promising messengers for signals of new physics Beyond the Standard Model (BSM). On the theoretical side, their elusive nature, combined with their unknown mass mechanism, seems to indicate that the neutrino sector is indeed opening a window to new physics. On the experimental side, several long-standing anomalies have been reported in the past decades, providing a strong motivation to thoroughly test the standard three-neutrino oscillation paradigm. In this Snowmass21 white paper, we explore the potential of current and future neutrino experiments to explore BSM effects on neutrino flavor during the next decade.

    hep-phhep-exEPJC(2023)·114 citations
12. 12*

    Angular Momentum Inheritance from the Schwinger Effect in (Chromo)electromagnetic Fields

    Patrick Copinger🇹🇼 · Yoshimasa Hidaka🇯🇵

    The angular momentum of fermion pairs generated by the Schwinger effect is studied in homogeneous (chromo)electromagnetic fields, mimicking the early stages of a heavy-ion collision. It is demonstrated that the angular momentum density of produced pairs is proportional to that of the background fields. This is argued both heuristically in a virtual breaking condensate model by evaluating Wong's equations, and out-of-equilibrium to one-loop using the in-in formalism.

    hep-phhep-thPTEP(2023)·3 citations
13. 13*

    YFS Resummation for Future Lepton-Lepton Colliders in SHERPA

    Frank Krauss🇬🇧 · Alan Price🇩🇪 · Marek Schönherr🇬🇧

    We present an implementation of the Yennie--\-Frautschi--\-Suura (YFS) scheme for the all-orders resummation of logarithms from the emission of soft real and virtual photons in processes that are critical for future lepton colliders. They include, in particular, $e^{-}{e}^{+}\to f\bar{f}$ and $e^{-}{e}^{+}\to W^{-}{W}^{+}$, where we validate the results of our implementation, improved with fixed-order corrections, with those obtained from the most precise calculations. We also show, for the first time, results for the Higgs-Strahlungs process, $e^{-}{e}^{+}\to ZH$, in YFS resummation including fixed-order improvements up to order ${\alpha }^3{L}^3$.

    hep-phSciPost Phys.(2022)·26 citations
14. 14*

    Investigating the QCD dynamical entropy in high-energy hadronic collisions

    G.S. Ramos🇧🇷 · M.V.T. Machado🇧🇷

    The dynamical entropy of dense gluonic states in proton-proton collisions at high energies is studied by using phenomenological models for the unintegrated gluon distribution. The corresponding transverse momentum probability distributions are evaluated in terms of rapidity. The dynamical entropy density is obtained in the rapidity range relevant for the collisions at the Large Hadron Collider. The total entropy density for the dense system is computed as a function of the rapidity evolution $\Delta Y=Y-Y_0$ given an initial rapidity $Y_0$. The theoretical uncertainties are investigated and comparison with related approaches in literature is done.

    hep-phhep-exhep-thPRD(2022)·16 citations
15. 15*

    Local Unitarity: cutting raised propagators and localising renormalisation

    Zeno Capatti🇨🇭 · Valentin Hirschi🇨🇭 · Ben Ruijl🇨🇭

    The Local Unitarity (LU) representation of differential cross-sections locally realises the cancellations of infrared singularities predicted by the Kinoshita-Lee-Nauenberg theorem. In this work we solve the two remaining challenges to enable practical higher-loop computations within the LU formalism. The first concerns the generalisation of the LU representation to graphs with raised propagators. The solution to this problem results in a generalisation of distributional Cutkosky rules. The second concerns the regularisation of ultraviolet and spurious soft singularities, solved using a fully automated and local renormalisation procedure based on Bogoliubov's R-operation. We detail an all-order construction for the hybrid $\overline{\text{MS}}$ and On-Shell scheme whose only analytic input is single-scale vacuum diagrams. Using this novel technology, we provide (semi-)inclusive results for two multi-leg processes at NLO, study limits of individual supergraphs up to N3LO and present the first physical NNLO cross-sections computed fully numerically in momentum-space, namely for the processes ${\gamma }^{\ast }\to jj$ and ${\gamma }^{\ast }\to t\bar{t}$.

    hep-phhep-thJHEP(2022)·39 citations
16. 16*

    Mass and width of an unstable particle

    Scott Willenbrock🇺🇸

    We show that the mass and width of an unstable particle are precisely defined by the pole in the complex energy plane, $\mu =m-(i/2)\Gamma$, by identifying the width, $\Gamma$, with the particle's decay rate and the mass, $m$, with the oscillatory frequency. We find that the physical $Z$ boson mass lies 26 MeV below its quoted value, while the physical $W$ boson mass lies 20 MeV below. We also clarify the various Breit-Wigner formulae that are used to describe a resonance.

    hep-phhep-exEur.Phys.J.Plus(2024)·16 citations
17. 17*

    Nambu--Jona-Lasinio model with a fractal inspired coupling

    E. Megias🇪🇸 · M. J. Teixeira🇧🇷 · V. S. Timóteo🇧🇷 · A. Deppman🇧🇷

    The Nambu--Jona-Lasino model is modified by the inclusion of a running-coupling that was obtained by a fractal approach to Quantum Chromodynamics. The coupling follows a $q$-exponential function and, in the context of high energy collisions, explains the origin of the Tsallis non-extensive statistics distributions. The parameter $q$ is completely determined in terms of the number of colours and the number of quark flavours. We study several aspects of the extended model and compare our results to the standard NJL model, where a constant coupling is used in combination with a sharp cutoff to regularize the gap equation. We show that the modified coupling regularizes the model in a smooth cutoff fashion and reproduces the pion mass and decay constant, providing an almost identical Gell-Mann-Oakes-Renner relation as in the standard NJL model. In both models the relation is satisfied in similar cutoff scales. An important novelty of this work is the physical explanation, in terms of the fractal QCD vacuum, for a running coupling that renormalizes the quark condensate.

    hep-phhep-latnucl-thPLB(2025)·5 citations
18. 18*

    Event Generators for High-Energy Physics Experiments

    J. M. Campbell🇺🇸 · M. Diefenthaler🇺🇸 · T. J. Hobbs🇺🇸 · S. Höche🇺🇸 · J. Isaacson🇺🇸 · F. Kling🇩🇪 · S. Mrenna🇺🇸 · J. Reuter🇩🇪 · S. Alioli🇮🇹 · J. R. Andersen🇬🇧 · C. Andreopoulos🇬🇧 · A. M. Ankowski🇺🇸 and 200 other authors

    We provide an overview of the status of Monte-Carlo event generators for high-energy particle physics. Guided by the experimental needs and requirements, we highlight areas of active development, and opportunities for future improvements. Particular emphasis is given to physics models and algorithms that are employed across a variety of experiments. These common themes in event generator development lead to a more comprehensive understanding of physics at the highest energies and intensities, and allow models to be tested against a wealth of data that have been accumulated over the past decades. A cohesive approach to event generator development will allow these models to be further improved and systematic uncertainties to be reduced, directly contributing to future experimental success. Event generators are part of a much larger ecosystem of computational tools. They typically involve a number of unknown model parameters that must be tuned to experimental data, while maintaining the integrity of the underlying physics models. Making both these data, and the analyses with which they have been obtained accessible to future users is an essential aspect of open science and data preservation. It ensures the consistency of physics models across a variety of experiments.

    hep-phhep-exSciPost Phys.(2024)·207 citations
19. 19*

    Electroweak fragmentation at high energies: A Snowmass White Paper

    Tao Han🇺🇸 · Yang Ma🇺🇸 · Keping Xie🇺🇸

    In particle collisions at energies higher than the mass scale involved, the collinear splitting becomes the dominant phenomena. Suitable descriptions of the physics in this regime include the parton distribution functions, the initial state radiations, the final state radiations and the fragmentation functions. It is of fundamental importance to formulate those functions with consistent theoretical treatments, and to provide the adequate formalism for applications, as motivated by the recent discussions of partonic scatterings at the multi-TeV energy regime. In this report, we briefly present the resummation of the final-state logarithms as fragmentation functions for the electroweak processes. As an explicit example, we study an electroweak gauge boson splitting in the process $pp\to WZj$ and demonstrate the important effects from the fragmentation.

    hep-phhep-th5 citations
20. 20*

    Renormalization of gluonic leading-twist Operators in covariant Gauges

    Giulio Falcioni🇬🇧 · Franz Herzog🇬🇧

    We provide the all-loop structure of gauge-variant operators required for the renormalisation of Green's functions with insertions of twist-two operators in Yang-Mills theory. Using this structure we work out an explicit basis valid up to 4-loop order for an arbitrary compact simple gauge group. To achieve this we employ a generalised gauge symmetry, originally proposed by Dixon and Taylor, which arises after adding to the Yang-Mills Lagrangian also operators proportional to its equation of motion. Promoting this symmetry to a generalised BRST symmetry allows to generate the ghost operator from a single exact operator in the BRST-generalised sense. We show that our construction complies with the theorems by Joglekar and Lee. We further establish the existence of a generalised anti-BRST symmetry which we employ to derive non-trivial relations among the anomalous dimension matrices of ghost and equation-of-motion operators. For the purpose of demonstration we employ the formalism to compute the N=2,4 Mellin moments of the gluonic splitting function up to 4 loops and its N=6 Mellin moment up to 3 loops, where we also take advantage of additional simplifications of the background field formalism.

    hep-phhep-thJHEP(2022)·26 citations
21. 21*

    Gravitational Waves from Quasi-stable Strings

    George Lazarides🇬🇷 · Rinku Maji🇮🇳 · Qaisar Shafi🇺🇸

    We estimate the stochastic gravitational wave spectrum emitted from a network of cosmic strings in which the latter are effectively stable against breaking by monopole pair creation. The monopoles are produced at a higher scale from an earlier symmetry breaking and experience significant inflation before reentering the horizon. This gives rise to monopole-antimonopole pairs connected by string segments and the string loop formation essentially ceases. As a consequence, the lower frequency portion of the gravitational wave spectrum is suppressed relative to the no-inflation case with stable strings, which evades the stringent PPTA bound on the dimensionless string tension $G\mu$. We display the modified spectrum, accessible in the ongoing and future experiments, for $G\mu$ values in the range $10^{-10}-10^{-15}$. We show how this `quasi-stable' string network is realized in realistic grand unified theories.

    hep-phastro-ph.COhep-thJCAP(2022)·44 citations
22. 22*

    Lepton-flavor violating axions at MEG II

    Yongsoo Jho🇰🇷 · Simon Knapen🇺🇸 · Diego Redigolo🇨🇭

    We study the sensitivity of the existing MEG data to lepton flavor violating axion-like particles produced through ${\mu }^{+}\to e^{+}a\gamma$ and estimate the discovery potential for the upcoming MEG II experiment in this channel. The MEG II signal efficiency can be improved significantly if a new trigger can be implemented in a dedicated run with a reduced beam intensity. This search would establish the world leading measurement in this channel with only 1 month of data taking.

    hep-phJHEP(2022)·63 citations
23. 23*

    NLO QCD Renormalization Group Evolution for Non-Leptonic $\Delta F=2$ Transitions in the SMEFT

    Jason Aebischer🇨🇭 · Andrzej J. Buras🇩🇪 · Jacky Kumar🇩🇪

    We present for the first time NLO QCD Renormalization Group (RG) evolution matrices for non-leptonic $\Delta F=2$ transitions in the Standard Model Effective Field Theory (SMEFT). To this end we transform first the known two-loop QCD anomalous dimension matrices (ADMs) of the BSM operators in the so-called BMU basis into the ones in the common Weak Effective Theory (WET) basis (the so-called JMS basis) for which tree-level and one-loop matching to the SMEFT are already known. This allows us subsequently to find the two-loop QCD ADMs for the SMEFT non-leptonic $\Delta F=2$ operators in the Warsaw basis. Having all these ingredients we investigate the impact of these NLO QCD effects on the QCD RG evolution of SMEFT Wilson coefficients for non-leptonic $\Delta F=2$ transitions from the new physics scale $\Lambda$ down to the electroweak scale ${\mu }_{\text{ew}}$. The main benefit of these new contributions is that they allow to remove renormalization scheme dependences present both in the one-loop matchings between the WET and SMEFT and also between SMEFT and a chosen UV completion. But the NLO QCD effects, calculated here in the NDR scheme, turn out to be small, in the ballpark of a few percent but larger than one-loop Yukawa top effects when only the $\Delta F=2$ operators are considered. The technology developed in our paper allows to obtain the ADMs in the SMEFT from the ones of the BMU basis also for non-leptonic $\Delta F=1$ decays and the results of this more involved analysis will be presented soon in another publication.

    hep-phhep-exhep-latPRD(2022)·30 citations
24. 24*

    Heisenberg's uncertainty principle in the PTOLEMY project: a theory update

    PTOLEMY Collaboration: A. Apponi🇮🇹 · M. G. Betti🇮🇹 · M. Borghesi🇮🇹 · A. Boyarsky🇳🇱 · N. Canci🇮🇹 · G. Cavoto🇮🇹 · C. Chang🇺🇸 · V. Cheianov🇳🇱 · Y. Cheipesh🇳🇱 · W. Chung🇺🇸 · A. G. Cocco🇮🇹 · A. P. Colijn🇳🇱 and 48 other authors

    We discuss the consequences of the quantum uncertainty on the spectrum of the electron emitted by the $\beta$-processes of a tritium atom bound to a graphene sheet. We analyze quantitatively the issue recently raised in [Cheipesh et al., Phys. Rev. D 104, 116004 (2021)], and discuss the relevant time scales and the degrees of freedom that can contribute to the intrinsic spread in the electron energy. We perform careful calculations of the potential between tritium and graphene with different coverages and geometries. With this at hand, we propose possible avenues to mitigate the effect of the quantum uncertainty.

    hep-phcond-mat.otherhep-exPRD(2022)·61 citations
25. 25*

    CP-violating axion interactions in effective field theory

    W. Dekens🇺🇸 · J. de Vries🇳🇱 · S. Shain🇳🇱

    Axions are introduced to explain the observed smallness of the $\bar{\theta }$ term of QCD. Standard Model extensions typically contain new sources of CP violation, for instance to account for the baryon asymmetry of the universe. In the presence of additional CP-violating sources a Peccei-Quinn mechanism does not remove all CP violation, leading to CP-odd interactions among axions and Standard Model fields. In this work, we use effective field theory to parametrize generic sources of beyond-the-Standard-Model CP violation. We systematically compute the resulting CP-odd couplings of axions to leptons and hadrons by using chiral perturbation theory. We discuss in detail the phenomenology of the CP-odd axion couplings and compare limits from axion searches, such as fifth force and monopole-dipole searches and astrophysics, to direct limits on the CP-violating operators from electric dipole moment experiments. While limits from electric dipole moment searches are tight, the proposed ARIADNE experiment can potentially improve the existing constraints in a window of axion masses.

    hep-phnucl-thJHEP(2022)·37 citations
26. 26*

    Three-loop non-singlet matching coefficients for heavy quark currents

    Manuel Egner🇩🇪 · Matteo Fael🇩🇪 · Fabian Lange🇩🇪 · Kay Schönwald🇩🇪 · Matthias Steinhauser🇩🇪

    We compute the matching coefficients between QCD and non-relativistic QCD for external vector, axial-vector, scalar and pseudo-scalar currents up to three-loop order. We concentrate on the non-singlet contributions and present precise numerical results with an accuracy of about ten digits. For the vector current the results from arXiv:1401.3004 are confirmed, increasing the accuracy by several orders of magnitude.

    hep-phPRD(2022)·9 citations
27. 27*

    Flux Compactifications, dS Vacua and the Swampland

    Christoph Roupec🇦🇹

    One of the main goals of the field of string phenomenology is to describe the properties of our spacetime in low-energy effective models related to and consistent with string theory. It is known that our universe undergoes accelerated expansion, which can be described in Einstein's theory of general relativity as a positive cosmological constant. Within string theory descriptions, this is realized by a scalar field with a positive value of its potential. Oftentimes, this is modeled by having the scalar at a stable, positive minimum. One then obtains a de Sitter spacetime. Constructions of de Sitter spaces from string theory are not straightforward and face many criticisms. In this thesis, we address several aspects related to this topic. We investigate the description of general branes in supergravity and in particular describe the uplifting anti-D3-brane of the KKLT model, including all world-volume fields. Additionally, we translate the type IIB based KKLT model into type IIA and introduce a mechanism that allows for the rapid construction of many de Sitter solutions. Related to this, we investigate models based on twisted 7-tori from M-theory and their relation to type II supergravity. These setups can also yield de Sitter solutions using the same mass production mechanism. One of the more recent and serious claims against the construction of de Sitter spaces in string theory, the de Sitter swampland conjecture, is also addressed here. We highlight the difficulty of obtaining a stable, positive vacuum energy in classical type IIA flux compactifications and their reliance on O-plane sources. Then, we turn our attention to the conjecture itself. Contrary to the initial claim, we find many unstable de Sitter points in numerical searches and go on to present our own refined conjecture that differs in several key aspects from the refined version of the original conjecture.

    ↳ hep-thgr-qchep-ph0 citations
28. 28*

    Analysis of quantum decay law: Is quantum tunneling really exponential?

    M. S. Hosseini-Ghalehni🇮🇷 · B. Azadegan🇮🇷 · S. A. Alavi🇮🇷

    The exponential decay law is well established since its first derivation in 1928, however it is not exact but only an approximate description. In recent years some experimental and theoretical indications for non-exponential decay have been documented. First we solve analytically the time-dependent Schrödinger equation in one dimension for a potential consisting of an infinite wall plus a rectangular barrier with finite width and also a cut harmonic oscillator potential by considering it as a sequence of square potentials. Then using the staggered Leap-Frog method, we solve the time-dependent Schrödinger equation for the cut harmonic oscillator potential. In both methods, time dependence of the survival probability of the particle and the decay parameter {\lambda} are analyzed. The results exhibit non-exponential behavior for survival probability at short and intermediate times.

    ↳ quant-phhep-phhep-thnucl-thEur.Phys.J.Plus(2022)·0 citations
29. 29*

    Study of Electroweak Phase Transition in Exotic Higgs Decays at the CEPC

    Zhen Wang🇨🇳 · Xuliang Zhu🇨🇳 · Elham E Khoda🇺🇸 · Shih-Chieh Hsu🇺🇸 · Nikolaos Konstantinidis🇬🇧 · Ke Li🇺🇸 · Shu Li🇨🇳 · Michael J. Ramsey-Musolf🇨🇳 · Yanda Wu🇨🇳 · Yuwen E. Zhang🇬🇧

    A strong first-order electroweak phase transition (EWPT) can be induced by light new physics weakly coupled to the Higgs. This study focuses on a scenario in which the first-order EWPT is driven by a light scalar $s$ with a mass between 15-60 GeV. A search for exotic decays of the Higgs boson into a pair of spin-zero particles, $h\to ss$, where the $s$-boson decays into $b$-quarks promptly is presented. The search is performed in events where the Higgs boson is produced in association with a $Z$ boson, giving rise to a signature of two charged leptons (electrons or muons) and multiple jets from $b$-quark decays. The analysis is considering a scenario of analysing 5000 fb${}^{-1}$ $e^{+}{e}^{-}$ collision data at $\sqrt{s}=240$ GeV from the Circular Electron Positron Collider (CEPC). This study with $4b$ final state conclusively tests the expected sensitivity of probing the light scalars in the CEPC experiment. The sensitivity reach is significantly larger than that can be achieved at the LHC.

    ↳ hep-exhep-ph18 citations
30. 30*

    Belle II Executive Summary

    D.M. Asner🇺🇸 · H. Atmacan🇺🇸 · Sw. Banerjee🇺🇸 · J.V. Bennett🇺🇸 · M. Bertemes🇦🇹 · M. Bessner🇺🇸 · D. Biswas🇺🇸 · G. Bonvicini🇺🇸 · N. Brenny🇺🇸 · R.A. Briere🇺🇸 · T.E. Browder🇺🇸 · C. Chen🇺🇸 and 69 other authors

    Belle II is a Super $B$ Factory experiment, expected to record 50 ab${}^{-1}$ of $e^{+}{e}^{-}$ collisions at the SuperKEKB accelerator until 2035. The large samples of $B$ mesons, charm hadrons, and tau leptons produced in the clean experimental environment of $e^{+}{e}^{-}$ collisions will provide the basis of a broad and unique flavor-physics program. Belle II will pursue physics beyond the Standard Model in many ways, for example: improving the precision of weak interaction parameters, particularly Cabibbo-Kobayashi-Maskawa (CKM) matrix elements and phases, and thus more rigorously test the CKM paradigm, measuring lepton-flavor-violating parameters, and performing unique searches for missing-mass dark matter events. Many key measurements will be made with world-leading precision.

    ↳ hep-exhep-ph5 citations
31. 31*

    Gravitational transitions via the explicitly broken symmetron screening mechanism

    Leandros Perivolaropoulos🇬🇷 · Foteini Skara🇬🇷

    We generalize the symmetron screening mechanism by allowing for an explicit symmetry breaking of the symmetron ${\varphi }^4$ potential. A coupling to matter of the form $A(\varphi )=1+\frac{{\varphi }^2}{M^2}$ leads to an explicitly broken symmetry with effective potential $V_{eff}(\varphi )=-{\mu }^2(1-\frac{\rho }{{\mu }^2{M}^2}){\varphi }^2+\frac{\lambda }{2}{\varphi }^4+2\epsilon {\varphi }^3+\frac{\lambda }{2}{\eta }^4$. Due to the explicit symmetry breaking induced by the cubic term we call this field the 'asymmetron'. For large matter density $\rho >{\rho }_{\ast }\equiv {\mu }^2{M}^2+\frac{9}{4}\epsilon \eta M^2$ the effective potential has a single minimum at $\varphi =0$ leading to restoration of General Relativity as in the usual symmetron screening mechanism. For low matter density however, there is a false vacuum and a single true vacuum due to the explicit symmetry breaking. This is expected to lead to an unstable network of domain walls with slightly different value of the gravitational constant $G$ on each side of the wall. This network would be in constant interaction with matter overdensities and would lead to interesting observational signatures which could be detected as gravitational and expansion rate transitions in redshift space. Such a gravitational transition has been recently proposed for the resolution of the Hubble tension.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2022)·27 citations
32. 32*

    Anomalous dimension and quasinormal modes of flavor branes

    Mahdi Atashi🇮🇷 · Kazem Bitaghsir Fadafan🇮🇷

    We study scalar quasinormal modes in a D3/D7 system holographically dual to a quantum field theory with chiral symmetry breaking at finite temperature. From the bottom-up approach, we consider a nontrivial dilaton profile which is responsible for the anomalous dimension of the quark condensate. It depends on a new parameter$q$ in the model. By varying this parameter, we study the behavior of the massive and massless scalar quasinormal modes. The numerical method that we use is the spectral method, and we find that there is no pure imaginary mode for the massless case but it appears by increasing the parameter $q$. It is known that this mode becomes tachyonic for massive cases. Then we turn on a pseudoscalar field and using a simple ansatz study its effect on the quasinormal modes of the scalar field. By varying the parameter of the nontrivial dilaton profile in the model, we qualitatively study quasinormal modes in walking theories.

    ↳ hep-thhep-ph3 citations
33. 33*

    Revealing Intrinsic Flat $\Lambda$CDM Biases with Standardizable Candles

    Eoin Ó Colgáin🇰🇷 · M. M. Sheikh-Jabbari🇮🇷 · Rance Solomon🇺🇸 · Giada Bargiacchi🇮🇹 · Salvatore Capozziello🇮🇹 · Maria Giovanna Dainotti🇯🇵 · Dejan Stojkovic🇺🇸

    Emerging high redshift cosmological probes, in particular quasars (QSOs), show a preference for larger matter densities, ${\Omega }_m\approx 1$, within the flat $\Lambda$CDM framework. Here, using the Risaliti-Lusso relation for standardizable QSOs, we demonstrate that the QSOs recover the \textit{same} Planck-$\Lambda$CDM Universe as Type Ia supernovae (SN), ${\Omega }_m\approx 0.3$ at lower redshifts $0<z\lesssim 0.7$, before transitioning to an Einstein-de Sitter Universe (${\Omega }_m=1$) at higher redshifts $z\gtrsim 1$. We illustrate the same trend, namely increasing ${\Omega }_m$ and decreasing $H_0$ with redshift, in SN but poor statistics prevent a definitive statement. We explain physically why the trend is expected in the flat $\Lambda$CDM cosmology, illustrate the intrinsic bias and non-Gaussian tails with mock Pantheon data, and identify a similar trend in BAO below $z=1$. Our results highlight an intrinsic bias in the flat $\Lambda$CDM Universe, whereby ${\Omega }_m$ increases, $H_0$ decreases and $S_8$ increases with effective redshift, thus providing a new perspective on $\Lambda$CDM tensions; even in a Planck-$\Lambda$CDM Universe the current tensions might have been expected.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2022)·143 citations
34. 34*

    A Statistical Analysis for the Neutrinoless Double-Beta Decay Matrix element of 48Ca

    M. Horoi🇺🇸 · A. Neacsu🇷🇴 · S. Stoica🇷🇴

    Neutrinoless double beta decay ($0\nu \beta \beta$) nuclear matrix elements (NME) are the object of many theoretical calculation methods, and are very important for analysis and guidance of a large number of experimental efforts. However, there are large discrepancies between the NME values provided by different methods. In this paper we propose a statistical analysis of the ${}^{48}$Ca $0\nu \beta \beta$ NME using the interacting shell model, emphasizing the range of the NME probable values and its correlations with observables that can be obtained from the existing nuclear data. Based on this statistical analysis with three independent effective Hamiltonians we propose a common probability distribution function for the $0\nu \beta \beta$ NME, which has a range of (0.45 - 0.95) at 90\% confidence level of, and a mean value of 0.68.

    ↳ nucl-thhep-phPRC(2022)·34 citations
35. 35*

    Prospects for slepton pair production in the future $e^{-}{e}^{+}$ Higgs factories

    Jiarong Yuan🇨🇳 · Huajie Cheng🇨🇳 · Xuai Zhuang🇨🇳

    The Circular Electron Positron Collider (CEPC) with a center-of-mass energy $\sqrt{s}$ = 240 GeV is proposed to serve as a Higgs factory, while it can also provide good opportunity for new physics searches at lower energy, which are difficult in hadron colliders but well-motivated by some theory models such as dark matter. This paper presents the sensitivity study of direct stau / smuon production at CEPC using full Monte Carlo (MC) simulation. With the assumption of flat 5% systematic uncertainty, the CEPC has the potential to discover the production of combined left-handed and right-handed stau up to 116 GeV if exists, or up to 113 GeV for the production of pure left-handed / right-handed stau; the discovery potential of direct smuon reaches up to 117 GeV with the same assumption. Due to the conserved assumption of systematic uncertainty and limited reliance on the reconstruction and detector geometry in this study, the results can be used as reference for similar searches in other electron positron colliders at a center-of-mass energy close to 240 GeV, such as Future Circular Collider $e^{+}{e}^{-}$ (FCC-ee) and the International Linear Collider (ILC).

    ↳ hep-exhep-ph7 citations
36. 36*

    Ghost condensates and pure kinetic $k$-essence condensates in presence of field-fluid non-minimal coupling in the dark sector

    Saddam Hussain🇮🇳 · Anirban Chatterjee🇮🇳 · Kaushik Bhattacharya🇮🇳

    In this article we try to find out the conditions when a ghost field in conjunction with a barotropic fluid produces a stable accelerating expansion phase of the universe. It is seen that in many cases the ghost field produces a condensate and drives the fluid energy density to zero in the final accelerating phase, but there can be other possibilities. We have shown that a pure kinetic $k$-essence field (which is not a ghost field) interacting with a fluid can also form an interaction induced condensate and produce a stable accelerating phase of the universe. In the latter case the fluid energy density does not vanish in the stable phase.

    ↳ gr-qcastro-ph.COhep-phUniverse(2023)·19 citations
37. 37*

    Using lower-redshift, non-CMB, data to constrain the Hubble constant and other cosmological parameters

    Shulei Cao🇺🇸 · Bharat Ratra🇺🇸

    We use updated Hubble parameter and baryon acoustic oscillation data, as well as other lower-redshift Type Ia supernova, Mg II reverberation-measured quasar, quasar angular size, H II starburst galaxy, and Amati-correlated gamma-ray burst data, to jointly constrain cosmological parameters in six cosmological models. The joint analysis provides model-independent determinations of the Hubble constant, $H_0=69.7\pm 1.2$ $\mathrm{km}{\mathrm{s}}^{-1}\mathrm{Mp}{\mathrm{c}}^{-1}$, and the current non-relativistic matter density parameter, ${\Omega }_{m0}=0.295\pm 0.017$. These error bars are factors of 2.2 and 2.3 larger than the corresponding error bars in the flat $\Lambda$CDM model from Planck TT,TE,EE+lowE+lensing cosmic microwave background anisotropy data. Based on the deviance information criterion (DIC), the flat $\Lambda$CDM model is most favored but mild dark energy dynamics and a little spatial curvature are not ruled out.

    ↳ astro-ph.COgr-qchep-phhep-thMNRAS(2022)·98 citations
38. 38*

    Cosmological Parameter Estimation Using Current and Future Observations of Strong Gravitational Lensing

    Jing-Zhao Qi🇨🇳 · Wei-Hong Hu🇨🇳 · Yu Cui🇨🇳 · Jing-Fei Zhang🇨🇳 · Xin Zhang🇨🇳

    Remarkable development of cosmology is benefited from the increasingly improved measurements of cosmic distances including absolute distances and relative distances. In recent years, however, the emerged cosmological tensions motivate us to explore the independent and precise late-universe probes. The two observational effects of strong gravitational lensing (SGL), the velocity dispersions of lens galaxies and the time delays between multiple images, can provide measurements of relative and absolute distances respectively, and their combination is possible to break the degeneracies between cosmological parameters and enable tight constraints on cosmological parameters. In this paper, we combine the observed 130 SGL systems with velocity-dispersion measurements and 7 SGL systems with time-delay measurements to constrain dark-energy cosmological models. It is found that the combination of the two effects does not significantly break the degeneracies between cosmological parameters as expected. However, with the simulations of 8000 SGL systems with well-measured velocity dispersions and 55 SGL systems with well-measured time delays based on the forthcoming LSST survey, we find that the combination of two effects can significantly break the parameter degeneracies, and make the constraint precision of cosmological parameters meet the standard of precision cosmology. We conclude that the observations of SGL will become a useful late-universe probe for precisely measuring cosmological parameters.

    ↳ astro-ph.COgr-qchep-phUniverse(2022)·15 citations
39. 39*

    Novel Physics with International Pulsar Timing Array: Axionlike Particles, Domain Walls and Cosmic Strings

    Deng Wang🇨🇳

    After NANOGrav, the IPTA collaboration also reports a strong evidence of a stochastic gravitation wave background. This hint has very important implications for fundamental physics. With the recent IPTA data release two, we attempt to search signals of light new physics. and give new constraints on the audible axion, domain walls and cosmic strings models. We find that the best fit point corresponding to a decay constant $F\approx 5\times 10^{17}$ GeV and an axion mass $m_a\approx 2\times 10^{-13}$ eV from NANOGrav data is ruled out by IPTA at beyond $2\sigma$ confidence level. Fixing the coupling strength $\lambda =1$, we obtain a $2\sigma$ lower bound on the breaking scale of $Z_2$ symmetry $\eta >135$ TeV. Interestingly, we give a very strong restriction on the cosmic-string tension ${\log }_{10}G\mu =-8.93_{-0.06}^{+0.12}$ at $1\sigma$ confidence level. Employing the rule of Bayes factor, we find that IPTA data has a moderate, strong and inconclusive preference of an uncorrelated common power-law (CPL) model over audible axion, domain walls and cosmic strings, respectively. This means that it is hard to distinguish CPL from cosmic strings with current observations and more pulsar timing data with high precision are required to give new clues of underlying physics.

    ↳ astro-ph.COastro-ph.HEgr-qchep-ph+119 citations
40. 40*

    Discovering new physics in rare kaon decays

    Thomas Blum🇺🇸 · Peter Boyle🇬🇧 · Mattia Bruno🇮🇹 · Norman Christ🇺🇸 · Felix Erben🇬🇧 · Xu Feng🇨🇳 · Vera Guelpers🇬🇧 · Ryan Hill🇬🇧 · Raoul Hodgson🇬🇧 · Danel Hoying🇺🇸 · Taku Izubuchi🇺🇸 · Yong-Chull Jang🇺🇸 and 11 other authors

    The decays and mixing of $K$ mesons are remarkably sensitive to the weak interactions of quarks and leptons at high energies. They provide important tests of the standard model at both first and second order in the Fermi constant $G_F$ and offer a window into possible new phenomena at energies as high as 1,000 TeV. These possibilities become even more compelling as the growing capabilities of lattice QCD make high-precision standard model predictions possible. Here we discuss and attempt to forecast some of these capabilities.

    ↳ hep-lathep-ph20 citations
41. 41*

    Cosmology from the vacuum

    Stefano Antonini🇺🇸 · Petar Simidzija🇨🇦 · Brian Swingle🇺🇸 · Mark Van Raamsdonk🇨🇦

    We argue that standard tools of holography can be used to describe fully non-perturbative microscopic models of cosmology in which a period of accelerated expansion may result from the positive potential energy of time-dependent scalar fields evolving towards a region with negative potential. In these models, the fundamental cosmological constant is negative, and the universe eventually recollapses in a time-reversal symmetric way. The microscopic description naturally selects a special state for the cosmology. In this framework, physics in the cosmological spacetime is dual to the vacuum physics in a static planar asymptotically AdS Lorentzian wormhole spacetime, in the sense that the background spacetimes and observables are related by analytic continuation. The dual spacetime is weakly curved everywhere, so any cosmological observables can be computed in the dual picture via effective field theory without detailed knowledge of the UV completion or the physics near the big bang. In particular, while inflation may explain the origin of perturbations in the cosmology picture, the perturbations can be deduced from the dual picture without any knowledge of the inflationary potential.

    ↳ hep-thastro-ph.COgr-qchep-phClass.Quant.Grav.(2024)·50 citations
42. 42*

    Snowmass2021 Cosmic Frontier CF6 White Paper: Multi-Experiment Probes for Dark Energy -- Transients

    Alex G. Kim🇺🇸 · Antonella Palmese🇺🇸 · Maria E. S. Pereira🇩🇪 · Greg Aldering🇺🇸 · Felipe Andrade-Oliveira🇺🇸 · James Annis🇺🇸 · Stephen Bailey🇺🇸 · Segev BenZvi🇺🇸 · Ulysses Braga-Neto🇺🇸 · Frédéric Courbin🇨🇭 · Alyssa Garcia🇺🇸 · David Jeffery🇺🇸 and 5 other authors

    This invited Snowmass 2021 White Paper highlights the power of joint-analysis of astronomical transients in advancing HEP Science and presents research activities that can realize the opportunities that come with current and upcoming projects. Transients of interest include gravitational wave events, neutrino events, strongly-lensed quasars and supernovae, and Type~Ia supernovae specifically. These transients can serve as probes of cosmological distances in the Universe and as cosmic laboratories of extreme strong-gravity, high-energy physics. Joint analysis refers to work that requires significant coordination from multiple experiments or facilities so encompasses Multi-Messenger Astronomy and optical transient discovery and distributed follow-up programs.

    ↳ astro-ph.COastro-ph.IMhep-exhep-ph6 citations
43. 43*

    The cosmic optical background excess, dark matter, and line-intensity mapping

    José Luis Bernal🇺🇸 · Gabriela Sato-Polito🇺🇸 · Marc Kamionkowski🇺🇸

    Recent studies using New Horizons LORRI images have returned the most precise measurement of the cosmic optical background to date, yielding a flux that exceeds that expected from deep galaxy counts by roughly a factor of two. We investigate whether this excess, detected at $\sim 4\sigma$ significance, is due to axion-like dark matter that decays to monoenergetic photons. We compute the spectral energy distribution from such decays and the contribution to the flux measured by LORRI. Assuming that axion-like particles make up all of the dark matter, the parameter space unconstrained to date that explains the measured excess spans masses and effective axion-photon couplings of 8 - 20 eV masses and 3 - 6 $\times 10^{-11}$ GeV${}^{-1}$, respectively. If the excess arises from dark-matter decay to a photon line, there will be a significant signal in forthcoming line-intensity mapping measurements that will allow the discrimination of this hypothesis from other candidates.

    ↳ astro-ph.COhep-phPRL(2022)·35 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.