Mon·Oct 31, 2022Monday·October 31, 2022

1. 01*

   Investigating exclusive ${\rho }^0$ photoproduction within the Regge phenomenology approach

   László Jenkovszky🇺🇦 · Érison dos Santos Rocha🇧🇷 · Magno V. T. Machado🇧🇷

   The elastic differential and integrated total cross section for the exclusive ${\rho }^0$ photoproduction in electron-proton ($ep$) collisions are evaluated taking into account nonperturbative Pomeron exchange approach. By using three different models based on Regge phenomenology the results are compared to recent measurements by H1 Collaboration in $ep$ collisions and by the CMS collaboration from ultraperipheral proton-lead collisions. The analysis is expanded by calculating the coherent nuclear cross section, $\sigma (\gamma A\to {\rho }^{0}A)$, which is applied to ${\rho }^0$ production in ultraperipheral lead-lead and xenon-xenon collisions. The predictions are compared to the measurements performed by ALICE Collaboration. Aspects of the theoretical uncertainties and limitations of the formalism are scrutinized.

   hep-phPLB(2022)·7 citations
2. 02*

   Open-Source Numerical Solver for Neutrino Collective Effects -- I: Isotropic Neutrino Gas

   Pedro Dedin Neto🇧🇷

   In this paper, we introduce a new open-source code to find numerical solutions for the neutrino evolution considering neutrino-neutrino interactions, which result in the so-called collective effects. We first describe the theoretical background of this type of evolution, explaining the polarization vector formalism in which we implement our numerical code. We then show the results for different neutrino systems. In this first paper, we focus on the case of an isotropic neutrino gas, exploring a mono-energetic scenario and one with a spectral distribution. The resulting code of this work is available at https://github.com/pedrodedin/Neutrino-Collective-Effects.

   hep-ph1 citation
3. 03*

   Probing a ${\mathrm{Z}}^{\prime }$ with non-universal fermion couplings through top quark fusion, decays to bottom quarks, and machine learning techniques

   Diego Barbosa🇨🇴 · Felipe Díaz🇨🇴 · Liliana Quintero🇨🇴 · Andrés Flórez🇨🇴 · Manuel Sanchez🇨🇴 · Alfredo Gurrola🇺🇸 · Elijah Sheridan🇺🇸 · Francesco Romeo🇺🇸

   The production of heavy mass resonances has been widely studied theoretically and experimentally. Several extensions of the standard model (SM) of particle physics, naturally give rise to a new resonance, with neutral electric charge, commonly referred to as the ${\text{Z}}^{\prime }$ boson. The nature, mass, couplings, and associated quantum numbers of this hypothetical particle are yet to be determined. We present a feasibility study on the production of a vector like ${\text{Z}}^{\prime }$ boson at the LHC, with preferential couplings to third generation fermions, considering proton-proton collisions at $\sqrt{s}=13$ $\mathrm{TeV}$ and 14 TeV. We work under two simplified phenomenological frameworks where the ${\mathrm{Z}}^{\prime }$ masses and couplings to the SM particles are free parameters, and consider final states of the ${\text{Z}}^{\prime }$ decaying to a pair of $\mathrm{b}$ quarks. The analysis is performed using machine learning techniques in order to maximize the experimental sensitivity. The proposed search methodology can be a key mode for discovery, complementary to the existing search strategies considered in literature, and extends the LHC sensitivity to the ${\mathrm{Z}}^{\prime }$ parameter space.

   hep-phEPJC(2023)·14 citations
4. 04*

   Fully-heavy tetraquark spectroscopy in the relativistic quark model

   R.N. Faustov🇷🇺 · V.O. Galkin🇷🇺 · E.M. Savchenko🇷🇺

   Masses of the ground and excited (1P, 2S, 1D, 2P, 3S) states of the fully-heavy tetraquarks, composed of charm ($c$) and bottom ($b$) quarks and antiquarks, are calculated in the diquark-antidiquark picture within the relativistic quark model based on the quasipotential approach and quantum chromodynamics. The quasipotentials of the quark-quark and diquark-antidiquark interactions are constructed similarly to the previous consideration of mesons and baryons. Relativistic effects are consistently taken into account. A tetraquark is considered as a bound state of a diquark and an antidiquark. The finite size of the diquark is taken into account, using the form factors of the diquark-gluon interaction. It is shown that most of the investigated states of tetraquarks lie above the decay thresholds into a meson pair, as a result they can be observed only as broad resonances. The narrow state X(6900) recently discovered in the di-$J/\psi$ production spectrum by the LHCb, CMS and ATLAS Collaborations corresponds to an excited state of the fully-charmed tetraquark. Other recently discovered exotic heavy resonances X(6200), X(6400), X(6600), X(7200), X(7300) can also be interpreted as the different excitations of the fully-charmed tetraquark.

   hep-phhep-exSymmetry(2022)·65 citations
5. 05*

   Precise Estimate of Charged Wino Decay Rate

   Masahiro Ibe🇯🇵 · Masataka Mishima🇯🇵 · Yuhei Nakayama🇯🇵 · Satoshi Shirai🇯🇵

   The Wino is an $\mathrm{SU}(2{)}_L$ triplet Majorana fermion and a well-motivated dark matter candidate. The mass difference between the charged and the neutral Winos is small thanks to the $\mathrm{SU}(2{)}_L$ symmetry. The small mass difference makes the charged Wino meta-stable, which provides disappearing charged track signatures at collider experiments. The constraint on the Wino dark matter at the LHC strongly depends on the Wino lifetime. We compute the next-to-leading order (NLO) correction of the charged Wino decay and make the most precise estimate of the decay rate. We find that the NLO decay rate is determined by the mass difference and scarcely depend on the Wino mass itself in the heavy Wino limit. As a result, we find the NLO correction gives a minor impact on the lifetime of 2-4% increase.

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

   Next-to-leading order perturbative QCD predictions for exclusive $J/\psi$ photoproduction in oxygen-oxygen and lead-lead collisions at the LHC

   Kari J. Eskola🇫🇮 · Christopher A. Flett🇫🇮 · Vadim Guzey🇫🇮 · Topi Löytäinen🇫🇮 · Hannu Paukkunen🇫🇮

   We present predictions for the cross sections of coherent $J/\psi$ photoproduction in lead-lead and oxygen-oxygen ultraperipheral collisions (UPCs) as a function of the $J/\psi$ rapidity at the LHC in the framework of collinear factorization at next-to-leading order (NLO) in perturbative QCD. Taking generalized parton distribution functions in their forward limit and using the EPPS21, nNNPDF3.0, and nCTEQ15WZSIH nuclear parton distribution functions, we update our recent results for Pb-Pb collisions, make detailed predictions for O-O collisions for several beam energy configurations, and examine the ratio of O-O and Pb-Pb UPC cross sections. We show that the latter observable allows one to significantly reduce the scale uncertainty of NLO predictions for this process.

   hep-phPRC(2023)·41 citations
7. 07*

   Sudakov effects and the dipole amplitude

   Tomoki Goda🇵🇱 · Krzysztof Kutak🇵🇱 · Sebastian Sapeta🇵🇱

   In this study we incorporate the Sudakov form factor into the dipole factorization formula, where the hard scale of the former is provided by the photon virtuality $Q^2$. We obtain a general formula which we then apply to the well-known GBW and BGK saturation models. Parameters of the above Sudakov-improved models are successfully fitted to the $F_2$ data from HERA. We observe, in particular, that inclusion of the Sudakov factor on top of the GBW model improves description of data at large $Q^2$.

   hep-phNPB(2023)·8 citations
8. 08*

   Sterile neutrino dark matter in the super-weak model

   Károly Seller🇭🇺

   The super-weak model is a U(1) extension of the Standard Model. In addition to a mediator $Z^{\prime }$, a singlet scalar field $\chi$ is added to deal with the meta-stability of the SM vacuum, and right-handed neutrinos are introduced to account for the non-vanishing neutrino masses. We demonstrate that the lightest right-handed neutrino is a possible dark matter candidate with masses of $\mathcal{O}(10)\mathrm{MeV}$ via the resonant freeze-out scenario. The dark matter production is explored and the available parameter space is discussed from the point of view of various experiments and beyond SM aspects.

   hep-phPoS(2022)·4 citations
9. 09*

   Are Leptons as elementary as Quarks?

   Aharon Davidson🇮🇱

   Nucleons and electrons were once considered elementary particles, a role nowadays taken by quarks and leptons. Here, mainly at the group theoretical level, we examine the unorthodox idea that nucleons and electrons share the same level of compositeness after all. We do it by first trading color $SU(3{)}_C$ for color/leptocolor $SU(3{)}_C\times SU(3{)}_{\ell C}$ confining gauge symmetry. Standard model leptons, equipped with inherited Yukawa couplings, make then their appearance at the intermediate (gauge protected) $SU(3{)}_C\times SU(3{)}_L\times SU(3{)}_R$ trinification stage as three pre-lepton composites. The addition of an exclusively prescribed (on anomaly free and Pauli exclusion grounds) spontaneously broken $SU(3{)}_F$ horizontal link to the unification chain, in the spirit of "One three to rule them all", strikingly preserves the anti-symmetric structure of the single family fermionic wave function. The threefold quark/lepton (spectators + composites) flavor chiral representation is then necessarily supplemented by a trinification singlet composite Majorana neutrino. The scheme serendipitously predicts a novel anomaly free lepto/dark portal.

   hep-phhep-th1 citation
10. 10*

    Baryogenesis in a Parity Solution to the Strong CP Problem

    Keisuke Harigaya🇺🇸 · Isaac R. Wang🇺🇸

    Space-time parity can solve the strong CP problem and introduces a spontaneously broken $SU(2{)}_R$ gauge symmetry. We investigate the possibility of baryogenesis from a first-order $SU(2{)}_R$ phase transition similar to electroweak baryogenesis. We consider a model with the minimal Higgs content, for which the strong CP problem is indeed solved without introducing extra symmetry beyond parity. Although the parity symmetry seems to forbid the $SU(2{)}_R$ anomaly of the $B-L$ symmetry, the structure of the fermion masses can allow for the $SU(2{)}_R$ sphaleron process to produce non-zero $B-L$ asymmetry of Standard Model particles so that the wash out by the $SU(2{)}_L$ sphaleron process is avoided. The setup predicts a new hyper-charged fermion whose mass is correlated with the $SU(2{)}_R$ symmetry breaking scale and hence with the $SU(2{)}_R$ gauge boson mass, and depending on the origin of CP violation, with an electron electric dipole moment. In a setup where CP violation and the first-order phase transition are assisted by a singlet scalar field, the singlet can be searched for at future colliders.

    hep-phastro-ph.COJHEP(2023)·12 citations
11. 11*

    The newly observed ${\rm Y}(10753)$ as a tetraquark state in a chiral quark model with scalar nonet exchange

    Yue Tan🇨🇳 · Xuejie Liu🇨🇳 · Xiaoyun Chen🇨🇳 · Hongxia Huang🇨🇳 · Jialun Ping🇨🇳

    Recently, Belle\uppercase\expandafter{\romannumeral2} Collaboration firstly reported a new resonance $\omega {\chi }_{bJ}$ in the processes of $e^{+}{e}^{-}\to \omega {\chi }_{bJ}$ at center-of-mass energies $\sqrt{s}=10.745$ GeV. Given the Born cross section similar with the previously reported ${\rm Y}(10753)$, the new resonance $\omega {\chi }_{bJ}$ may have be ${\rm Y}(10753)$. From the perspectives of traditional ${\rm Y}(nS)$ meson and exotic tetraquark $b\bar{q}q\bar{b}$ state with the $J^{PC}$ = $1^{--}$, we tentatively investigate the ${\rm Y}(10753)$ by solving Schrödinger equation in the framework of the chiral quark model. Numerical results for the meson show that the mass of ${\rm Y}(5S)$ is up to 10.86 GeV and unsuitable for the candidate of ${\rm Y}(10753)$. On the other hand, not only the two kinds of molecular structure ($b\bar{b}$-$q\bar{q}$, $b\bar{q}$-$q\bar{b}$) but also the \da~structure ($\bar{b}\bar{q}$-$qb$) are considered into our tetraquark calculation with the help of Gaussian expansion method. When a fully-channel coupling is performed using the real-scaling method (stabilization method), we get a stable resonance ${}^1{R}_1(10770)$ ( ${}^{2S+1}{R}_J$ ) with a great component of the diquark-antidiquark state. Combined with the mass and width of ${}^1{R}_1(10770)$, it may be a good candidate for experimental ${\rm Y}(10753)$. Besides, several resonance states ranging from 10.82 GeV to 10.96 GeV are obtained, which are expected to be further verified in future experiments.

    hep-phPRD(2023)·8 citations
12. 12*

    $\nu$ Electroweak Baryogenesis: The Scalar Singlet Strikes Back

    E. Fernández-Martínez🇪🇸 · J. López-Pavón🇪🇸 · J. M. No🇪🇸 · T. Ota🇪🇸 · S. Rosauro-Alcaraz🇫🇷

    We perform a thorough scan of the parameter space of a general singlet scalar extension of the Standard Model to identify the regions which can lead to a strong first-order phase transition, as required by the electroweak baryogenesis mechanism. We find that taking into account bubble nucleation is a fundamental constraint on the parameter space and present a conservative and fast estimate for it to enable efficient parameter space scanning. The allowed regions turn out to be already significantly probed by constraints on the scalar mixing from Higgs signal strength measurements. We also consider the addition of new neutrino singlet fields with Yukawa couplings to both scalars and forming heavy (pseudo)-Dirac pairs, as in the linear or inverse see-saw mechanisms for neutrino mass generation. Interestingly, we identify an interplay between the strength of the phase transition and the stability of the electroweak vacuum which prevents these Yukawa couplings to become arbitrarily large. Thus, their inclusion does not alter the early universe phenomenology or allowed parameter space in a significant way. Conversely, we find allowed regions of the parameter space where the presence of the neutrino singlets would remarkably modify the collider phenomenology, yielding interesting new signatures in Higgs and singlet scalar decays.

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

    Constraining Lepton Flavor Violating Higgs Couplings at the HL-LHC in the Vector Boson Fusion Channel

    Rahool Kumar Barman🇺🇸 · P. S. Bhupal Dev🇺🇸 · Anil Thapa🇺🇸

    We explore the parameter space of lepton flavor violating (LFV) neutral Higgs Yukawa couplings with the muon and tau leptons that can be probed at the high-luminosity Large Hadron Collider (HL-LHC) via the vector boson fusion~(VBF) Higgs production process. Our projected sensitivities for the Standard Model Higgs ($h$) LFV branching ratio $\mathrm{Br}(h\to \mu \tau )$ in the $pp\to hjj\to (h\to \mu \tau )jj$ channel at the HL-LHC are contrasted with the current and future low-energy constraints from the anomalous magnetic moment and electric dipole moment of the muon, as well as with other LFV observables, such as $\tau \to 3\mu$ and $\tau \to \mu \gamma$. We also study the LFV prospects of a generic beyond the Standard Model neutral Higgs boson ($H$) with a mass in the range of $m_H\in [20,800]$GeV and give the projected model-independent upper limits on the VBF production cross-section of $Hjj$ times the branching ratio of $H\to \mu \tau$ at the HL-LHC. We interpret these results in the context of a two-Higgs doublet model as a case study.

    hep-phPRD(2023)·18 citations
14. 14*

    The Scalar Singlet Extension of the Standard Model: Gravitational Waves versus Baryogenesis

    John Ellis🇬🇧 · Marek Lewicki🇵🇱 · Marco Merchand🇵🇱 · José Miguel No🇪🇸 · Mateusz Zych🇵🇱

    We study the possible gravitational wave signal and the viability of baryogenesis arising from the electroweak phase transition in an extension of the Standard Model (SM) by a scalar singlet field without a ${\mathbb{Z}}_2$ symmetry. We first analyze the velocity of the expanding true-vacuum bubbles during the phase transition, confirming our previous finding in the unbroken ${\mathbb{Z}}_2$ symmetry scenario, where the bubble wall velocity can be computed from first principles only for weak transitions with strength parameters $\alpha \lesssim 0.05$, and the Chapman-Jouguet velocity defines the maximum velocity for which the wall is stopped by the friction from the plasma. We further provide an analytical approximation to the wall velocity in the general scalar singlet scenario without ${\mathbb{Z}}_2$ symmetry and test it against the results of a detailed calculation, finding good agreement. We show that in the singlet scenario with a spontaneously broken ${\mathbb{Z}}_2$ symmetry, the phase transition is always weak and we see no hope for baryogenesis. In contrast, in the case with explicit ${\mathbb{Z}}_2$ breaking there is a region of the parameter space producing a promising baryon yield in the presence of CP violating interactions via an effective operator involving the singlet scalar and the SM top quarks. Yet, we find that this region yields unobservable gravitational waves. Finally, we show that the promising region for baryogenesis in this model may be fully tested by direct searches for singlet-like scalars in di-boson final states at the HL-LHC, combined with present and future measurements of the electron electric dipole moment.

    hep-phastro-ph.COJHEP(2023)·91 citations
15. 15*

    The Continuum Dark Matter Zoo

    Csaba Csaki🇺🇸 · Ameen Ismail🇺🇸 · Seung J. Lee🇰🇷

    We generalize the recently proposed continuum dark matter model to the case where the dark matter consists of a spin-$1/2$ or spin-$1$ gapped continuum. We construct simple continuum analogs of weakly interacting massive particles annihilating through the $Z$ portal. We discuss all existing experimental constraints, with the strongest bounds arising from indirect detection and limits on continuum decays from the cosmic microwave background. Our models are phenomenologically viable for gap scales of $60$-$200$ GeV (spin-$1/2$) and $35$-$90$ GeV (spin-$1$), owing to the strong kinematic suppression of direct detection bounds which is unique to continuum states. We comment on future prospects for detection and suggest directions for further continuum model building.

    hep-phJHEP(2023)·15 citations
16. 16*

    Two is better than one: The U-spin-CP anomaly in charm

    Rigo Bause🇩🇪 · Hector Gisbert🇩🇪 · Gudrun Hiller🇩🇪 · Tim Höhne🇩🇪 · Daniel F. Litim🇬🇧 · Tom Steudtner🇩🇪

    The recent measurement of the CP-asymmetry in the decay $D\to K^{+}{K}^{-}$ by LHCb, combined with $\Delta A_{\text{CP}}$, evidences a sizable CP-asymmetry in $D\to {\pi }^{+}{\pi }^{-}$ decays, which requires a dynamical enhancement of standard model higher-order contributions over tree-level ones by a factor of two. The data furthermore imply huge U-spin breaking, about 4-5 times larger than the nominal standard model one of $\lesssim 30\%$ in charm. Enhanced breakdown of the two approximate symmetries points to models that violate U-spin and CP and disfavors flavor singlet contributions such as chromomagnetic dipole operators as explanations of the data. We analyze the reach of flavorful $Z^{\prime }$ models for charm CP-asymmetries. Models feature explicit U-spin and isospin breaking, allowing for correlations with $D\to {\pi }^0{\pi }^0$ and $D^{+}\to {\pi }^{+}{\pi }^0$ decays with corresponding CP-asymmetries at a similar level and sign as $D\to {\pi }^{+}{\pi }^{-}$, about $\mathcal{O}(1-2)\cdot 10^{-3}$. Experimental and theoretical constraints narrow down the shape of viable models: anomaly-free models are leptophobic -- or at least electro- and muo-phobic -- with light $Z^{\prime }$ below $\mathcal{O}(20)$ GeV, and can be searched for in low mass dijets at the LHC, ${\rm Y}$ and charmonium decays, and dark photon signatures. A $Z^{\prime }$ around $\sim 3$ GeV or $\sim (5-7)$ GeV can relieve the tensions in the $J/\psi \to {\pi }^{+}{\pi }^{-}$ and ${\psi }^{\prime }\to {\pi }^{+}{\pi }^{-}$ branching ratios with pion form factors from fits to Babar and JLab data, and simultaneously explain the charm CP asymmetries. Models also feature sizable branching ratios into light right-handed neutrinos or vector-like dark fermions, which can be searched for in $e^{+}{e}^{-}\to$~hadrons + invisibles at Belle II and BESIII. Due to the low new physics scale dark fermions may induce an early Landau pole which requires UV-completion near the TeV-scale.

    hep-phPRD(2023)·37 citations
17. 17*

    The CMSSM Survives Planck, the LHC, LUX-ZEPLIN, Fermi-LAT, H.E.S.S. and IceCube

    John Ellis🇬🇧 · Keith A. Olive🇺🇸 · Vassilis C. Spanos🇬🇷 · Ioanna D. Stamou🇧🇪

    We revisit the viability of the CMSSM, searching for regions of parameter space that yield a neutralino dark matter density compatible with Planck measurements, as well as LHC constraints including sparticle searches and the mass of the Higgs boson, recent direct limits on spin-independent and -dependent dark matter scattering from the LUX-ZEPLIN (LZ) experiment, the indirect constraints from Fermi-LAT and H.E.S.S. on dark matter annihilations to photons in dwarf spheroidal galaxies and the Galactic Centre, and the IceCube limits on muons from annihilations to neutrinos in the Sun. For representative values of $\tan \beta$ and $A_0$ we map in detail the Planck-compatible strips in CMSSM parameter planes, which exhibit multiple distinctive features for large $\tan \beta$, $A_0=0$ and $\mu >0$, and identify portions of the strips that survive all the phenomenological constraints. We find that the most powerful constraint is that from $m_h$, followed by the LZ limit on spin-independent scattering, whereas sparticle searches at the LHC and indirect dark matter searches are less restrictive. Most of the surviving CMSSM parameter space features a Higgsino-like dark matter particle with a mass $\sim 1000-1100$ GeV, which could best be probed with future direct searches for dark matter scattering.

    hep-phastro-ph.COhep-exhep-thEPJC(2023)·29 citations
18. 18*

    Constraining properties of asymmetric dark matter candidates from gravitational-wave observations

    Divya Singh🇺🇸 · Anuradha Gupta🇺🇸 · Emanuele Berti🇺🇸 · Sanjay Reddy🇺🇸 · B. S. Sathyaprakash🇺🇸

    The accumulation of certain types of dark matter particles in neutron star cores due to accretion over long timescales can lead to the formation of a mini black hole. In this scenario, the neutron star is destabilized and implodes to form a black hole without significantly increasing its mass. When this process occurs in neutron stars in coalescing binaries, one or both stars might be converted to a black hole before they merge. Thus, in the mass range of $\sim \text{mbox}1--2M_{\odot },$ the Universe might contain three distinct populations of compact binaries: one containing only neutron stars, the second population of only black holes, and a third, mixed population consisting of a neutron star and a black hole. However, it is unlikely to have a mixed population as the various timescales allow for both neutron stars to remain or collapse within a short timescale. In this paper, we explore the capability of future gravitational-wave detector networks, including upgrades of Advanced LIGO and Virgo, and new facilities such as the Cosmic Explorer and Einstein Telescope (XG network), to discriminate between different populations by measuring the effective tidal deformability of the binary, which is zero for binary black holes but nonzero for binary neutron stars. Furthermore, we show that observing the relative abundances of the different populations can be used to infer the timescale for neutron stars to implode into black holes, and in turn, provide constraints on the particle nature of dark matter. The XG network will infer the implosion timescale to within an accuracy of 0.01 Gyr at 90% credible interval and determine the dark matter mass and interaction cross section to within a factor of 2 GeV and 10 cm${}^{-2}$, respectively.

    ↳ gr-qcastro-ph.HEhep-phPRD(2023)·38 citations
19. 19*

    GRB 221009A: A light dark matter burst or an extremely bright Inverse Compton component?

    M. M. González🇲🇽 · D. Avila Rojas🇲🇽 · A. Pratts🇲🇽 · S Hernández-Cadena🇲🇽 · N. Fraija🇲🇽 · R. Alfaro🇲🇽 · Y. Pérez Araujo🇲🇽 · J. A. Montes🇲🇽

    Gamma-ray bursts (GRBs) have been considered as potential very high-energy photon emitters due to the large amount of energy released as well as the strong magnetic fields involved in their jets. However, the detection of TeV photons is not expected from bursts beyond a redshift of $z\gtrsim 0.1$ due to their attenuation with the extragalactic background light (EBL). For these reasons, the recent observation of photons with energies of 18 and 251 TeV from GRB 221009A (z=0.151) last October 9th, 2022 has challenged what we know about the TeV-emission mechanisms and the extragalactic background. In order to explain the TeV observations, recent works exploring candidates of dark matter have started to appear. In this paper, we discuss the required conditions and limitations within the most plausible scenario, synchrotron-self Compton (SSC) radiation in the GRB afterglow, to interpret the one 18-TeV photon observation besides the EBL. To avoid the Klein-Nishina effect, we find an improbable value of the microphysical magnetic parameter below $10^{-6}$ for a circumburst medium value $>1\mathrm{c}{\mathrm{m}}^{-3}$ (expected in the collapsar scenario). Therefore, we explore possible scenarios in terms of ALPs and dark photon mechanisms to interpret this highly-energetic photon and we discuss the implications in the GRB energetics. We find that the ALPs and dark photon scenarios can explain the 18 TeV photon but not the 251 TeV photon.

    ↳ astro-ph.HEhep-phApJ(2023)·36 citations
20. 20*

    Ultrafast modulations in stellar, solar and galactic spectra: Dark Matter and numerical ghosts, stellar flares and SETI

    Fabrizio Tamburini🇩🇪 · Ignazio Licata🇮🇹

    From new results presented in the literature we discuss the hypothesis that the ultrafast periodic spectral modulations at $f_S\simeq 0.607$ THz found in the spectra of $236$ stars of the Sloan Digital Sky Survey (SDSS) [1] were due to oscillations induced by dark matter (DM) cores in their centers [2] behaving as oscillating boson stars [3,4]. Two additional frequencies in the redshift-corrected SDSS galactic spectra were found [5], $f_{1,G}\simeq 9.5$ THz, the beating between $f_S$ and a spurious frequency, $f_{2,G}\simeq 8.9$ THz, introduced during the data analysis [6]. The indication that $f_S$ can be real is its detection in a real solar spectrum but not in the Kurucz's artificial solar spectrum [6,7,8]. Then, independent SETI observations of four of these stars could not confirm with high confidence, but not completely exclude, the presence of $f_S$ in their power spectra [9] while the radio SETI deep-learning analysis with artificial intelligence confirmed indirectly $f_S$ detecting a narrowband Doppler drifting of radio signals in two of these stars over a sample of $7$ with a high S/N [10]. Numerical simulations suggest that the drifting can be due to frequency and phase modulation in time of the observed frequencies at $1.3-1.7$ GHz with $f_S$. This would imply a DM upper mass limit $m_a\lesssim 2.4\times 10^3\mu \mathrm{eV}$ [2] which also agrees with the results from the gamma ray burst GRB221009A [11,12,13], laser interferometry [14], suggesting new physics for the muon g-2 anomaly [15].

    ↳ astro-ph.GAastro-ph.HEastro-ph.SRgr-qc+1Particles(2024)·0 citations
21. 21*

    Constraints on heavy decaying dark matter from 570 days of LHAASO observations

    The LHAASO Collaboration · Zhen Cao · F. Aharonian · Q. An · Axikegu · L. X. Bai · Y. X. Bai · Y.W. Bao · D. Bastieri · X. J. Bi · Y. J. Bi · J. T. Cai and 269 other authors

    The Kilometer Square Array~(KM2A) of the Large High Altitude Air Shower Observatory (LHAASO) aims at surveying the northern gamma-ray sky at energies above 10 TeV with unprecedented sensitivity. Gamma-ray observations have long been one of the most powerful tools for dark matter searches, as e.g., high-energy gamma-rays could be produced by the decays of heavy dark matter particles. In this letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340~days of data from 1/2-KM2A and 230~days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after gamma/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest gamma-ray constraints on the lifetime of heavy dark matter particles with mass between 10^5 and 10^9~GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

    ↳ astro-ph.HEastro-ph.COhep-phPRL(2022)·57 citations
22. 22*

    Hybrid multi-fluid-particle simulations of the cosmic neutrino background

    Joe Zhiyu Chen🇦🇺 · Markus R. Mosbech🇦🇺 · Amol Upadhye🇦🇺 · Yvonne Y. Y. Wong🇦🇺

    Simulation of the cosmic clustering of massive neutrinos is a daunting task, due both to their large velocity dispersion and to their weak clustering power becoming swamped by Poisson shot noise. We present a new approach, the multi-fluid hybrid-neutrino simulation, which partitions the neutrino population into multiple flows, each of which is characterised by its initial momentum and treated as a separate fluid. These fluid flows respond initially linearly to nonlinear perturbations in the cold matter, but slowest flows are later converted to a particle realisation should their clustering power exceed some threshold. After outlining the multi-fluid description of neutrinos, we study the conversion of the individual flows into particles, in order to quantify transient errors, as well as to determine a set of criteria for particle conversion. Assembling our results into a total neutrino power spectrum, we demonstrate that our multi-fluid hybrid-neutrino simulation is convergent to $<3\%$ if conversion happens at $z=19$ and agrees with more expensive simulations in the literature for neutrino fractions as high as ${\Omega }_{\nu }{h}^2=0.005$. Moreover, our hybrid-neutrino approach retains fine-grained information about the neutrinos' momentum distribution. However, the momentum resolution is currently limited by free-streaming transients excited by missing information in the neutrino particle initialisation procedure, which restricts the particle conversion to z $\gtrsim 19$ if percent-level resolution is desired.

    ↳ astro-ph.COhep-phJCAP(2023)·11 citations
23. 23*

    Sequential hypothesis testing for Axion Haloscopes

    Andrea Gallo Rosso🇸🇪 · Sara Algeri🇺🇸 · Jan Conrad🇸🇪

    The goal of this paper is to introduce a novel likelihood-based inferential framework for axion haloscopes which is valid under the commonly applied "rescanning" protocol. The proposed method enjoys short data acquisition times and a simple tuning of the detector configuration. Local statistical significance and power are computed analytically, avoiding the need of burdensome simulations. Adequate corrections for the look-elsewhere effect are also discussed. The performance of our inferential strategy is compared with that of a simple method which exploits the geometric probability of rescan. Finally, we exemplify the method with an application to a HAYSTAC type axion haloscope.

    ↳ physics.data-anastro-ph.IMhep-exhep-phPRD(2023)·5 citations
24. 24*

    Bremsstrahlung as a probe of baryon stopping in heavy-ion collisions

    Sigurd Nese🇳🇴 · Joakim Nystrand🇳🇴

    In collisions between heavy ions at ultra-relativistic energies the participating protons lose energy, which is converted into new particles. As the protons slow down, they emit bremsstrahlung radiation. The yield and angular distribution of the emitted radiation are sensitive probes of how much energy the incoming protons have lost. In this paper, the spectrum of bremsstrahlung radiation is calculated for different stopping scenarios, and the results are compared with the expected yield of photons from hadronic interactions.

    ↳ nucl-thhep-phEPJC(2023)·2 citations
25. 25*

    Is the "RG-invariant EFT'' for few-nucleon systems cutoff independent?

    A. M. Gasparyan🇩🇪 · E. Epelbaum🇩🇪

    We consider nucleon-nucleon scattering using the formulation of chiral effective field theory which is claimed to be renormalization group invariant. The cornerstone of this framework is the existence of a well-defined infinite-cutoff limit for the scattering amplitude at each order of the expansion, which should not depend on a particular regulator form. Focusing on the ${}^3{P}_0$ partial wave as a representative example, we show that this requirement can in general not be fulfilled beyond the leading order, in spite of the perturbative treatment of subleading contributions to the amplitude. Several previous studies along these lines, including the next-to-leading order calculation by Long and Yang [Phys. Rev. C84, 057001 (2011)] and a toy model example with singular long-range potentials by Long and van Kolck [Annals Phys. 323, 1304-1323 (2008)], are critically reviewed and scrutinized in detail.

    ↳ nucl-thhep-lathep-phPRC(2023)·30 citations
26. 26*

    Resolving the Hubble tension with Early Dark Energy

    Laura Herold🇩🇪 · Elisa G. M. Ferreira🇯🇵

    Early dark energy (EDE) offers a solution to the so-called Hubble tension. Recently, it was shown that the constraints on EDE using Markov Chain Monte Carlo are affected by prior volume effects. The goal of this paper is to present constraints on the fraction of EDE, $f_{\mathrm{EDE}}$, and the Hubble parameter, $H_0$, which are not subject to prior volume effects. We conduct a frequentist profile likelihood analysis considering Planck cosmic microwave background, BOSS full-shape galaxy clustering, DES weak lensing, and SH0ES supernova data. Contrary to previous findings, we find that $H_0$ for the EDE model is in statistical agreement with the SH0ES direct measurement at $\le 1.7\sigma$ for all data sets. For our baseline data set (Planck + BOSS), we obtain $f_{\mathrm{EDE}}=0.087\pm 0.037$ and $H_0=70.57\pm 1.36km/s/Mpc$ at $68\%$ confidence limit. We conclude that EDE is a viable solution to the Hubble tension.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2023)·90 citations
27. 27*

    Fermi Surface Symmetric Mass Generation

    Da-Chuan Lu🇺🇸 · Meng Zeng🇺🇸 · Juven Wang🇺🇸 · Yi-Zhuang You🇺🇸

    Symmetric mass generation is a novel mechanism to give gapless fermions a mass gap by non-perturbative interactions without generating any fermion bilinear condensation. The previous studies of symmetric mass generation have been limited to Dirac/Weyl/Majorana fermions with zero Fermi volume in the free fermion limit. In this work, we generalize the concept of symmetric mass generation to Fermi liquid with a finite Fermi volume and discuss how to gap out the Fermi surfaces by interactions without breaking the U(1) loop group symmetry or developing topological orders. We provide examples of Fermi surface symmetric mass generation in both (1+1)D and (2+1)D Fermi liquid systems when several Fermi surfaces together cancel the Fermi surface anomaly. However, the U(1) loop group symmetry in these cases is still restrictive enough to rule out all possible fermion bilinear gapping terms, such that a non-perturbative interaction mechanism is the only way to gap out the Fermi surfaces. This symmetric Fermi surface reconstruction is in contrast to the conventional symmetry-breaking mechanism to gap the Fermi surfaces. As a side product, our model provides a pristine 1D lattice regularization for the (1+1)D U(1) symmetric chiral fermion model (e.g., the 3-4-5-0 model) by utilizing a lattice translation symmetry as an emergent U(1) symmetry at low energy. This opens up the opportunity for efficient numerical simulations of chiral fermions in their own dimensions without introducing mirror fermions under the domain wall fermion construction.

    ↳ cond-mat.str-elhep-lathep-phhep-th+1PRB(2023)·28 citations
28. 28*

    Colliding Ghosts: Constraining Inflation with the Parity-Odd Galaxy Four-Point Function

    Giovanni Cabass🇺🇸 · Mikhail M. Ivanov🇺🇸 · Oliver H. E. Philcox🇺🇸

    Could new physics break the mirror symmetry of the Universe? Utilizing recent measurements of the parity-odd four-point correlation function of BOSS galaxies, we probe the physics of inflation by placing constraints on the amplitude of a number of parity-violating models. Within canonical models of (single-field, slow-roll) inflation, no parity-asymmetry can occur; however, it has recently been shown that breaking of the standard assumptions can lead to parity violation within the Effective Field Theory of Inflation (EFTI). In particular, we consider the Ghost Condensate and Cosmological Collider scenarios -- the former for the leading and subleading operators in the EFTI and the latter for different values of mass and speed of an exchanged spin-$1$ particle -- for a total of $18$ models. Each instance yields a definite prediction for the inflationary trispectrum, which we convert to a late-time galaxy correlator prediction (through a highly non-trivial calculation) and constrain using the observed data. We find no evidence for inflationary parity-violation (with each of the $18$ models having significances below $2\sigma$), and place the first constraints on the relevant coupling strengths, at a level comparable with the theoretical perturbativity bounds. This is also the first time Cosmological Collider signatures have directly been searched for in observational data. We further show that possible secondary parity-violating signatures in galaxy clustering can be systematically described within the Effective Field Theory of Large-Scale Structure. We argue that these late-time contributions are subdominant compared to the primordial parity-odd signal for a vast region of parameter space. In summary, the results of this paper disfavor the notion that the recent hints of parity-violation observed in the distribution of galaxies are due to new physics.

    ↳ astro-ph.COastro-ph.GAgr-qchep-ph+1PRD(2023)·78 citations
29. 29*

    Endothermic self-interacting dark matter in Milky Way-like dark matter haloes

    Stephanie O'Neil (1)🇺🇸 · Mark Vogelsberger (1,2)🇺🇸 · Saniya Heeba (3)🇨🇦 · Katelin Schutz (3)🇨🇦 · Jonah C. Rose (4)🇺🇸 · Paul Torrey (4)🇺🇸 · Josh Borrow (1)🇺🇸 · Ryan Low (5)🇺🇸 · Rakshak Adhikari (5)🇺🇸 · Mikhail V. Medvedev (5,6)🇺🇸 · Tracy R. Slatyer (1,2,7)🇺🇸 · Jesús Zavala (8) ((1) MIT, (2) AIFAI MIT, (3) McGill, (4) UFL, (5) KU, (7) MIT CTP, (8) University of Iceland)🇮🇸

    Self-interacting dark matter (SIDM) offers the potential to mitigate some of the discrepancies between simulated cold dark matter (CDM) and observed galactic properties. We introduce a physically motivated SIDM model to understand the effects of self interactions on the properties of Milky Way and dwarf galaxy sized haloes. This model consists of dark matter with a nearly degenerate excited state, which allows for both elastic and inelastic scattering. In particular, the model includes a significant probability for particles to up-scatter from the ground state to the excited state. We simulate a suite of zoom-in Milky Way-sized N-body haloes with six models with different scattering cross sections to study the effects of up-scattering in SIDM models. We find that the up-scattering reaction greatly increases the central densities of the main halo through the loss of kinetic energy. However, the physical model still results in significant coring due to the presence of elastic scattering and down-scattering. These effects are not as apparent in the subhalo population compared to the main halo, but the number of subhaloes is reduced compared to CDM.

    ↳ astro-ph.GAhep-phMNRAS(2023)·37 citations
30. 30*

    Scaling Transformations and the Origins of Light Relics Constraints from Cosmic Microwave Background Observations

    Fei Ge🇺🇸 · Francis-Yan Cyr-Racine🇺🇸 · Lloyd Knox🇺🇸

    We use here a family of scaling transformations, that scale key rates in the evolution equations, to analytically understand constraints on light relics from cosmic microwave background (CMB) maps, given cosmological models of varying degrees of complexity. We describe the causes of physical effects that are fundamentally important to the constraining power of the data, with a focus on the two that are most novel. We use as a reference model a cosmological model that admits a scaling transformation that increases light relic energy density while avoiding all of these causes. Constraints on light relics in a given model can then be understood as due to the differences between the given model and the reference model, as long as the additional light relics only interact gravitationally with the Standard Model components. This understanding supports the development of cosmological models that can evade light relics constraints from CMB maps.

    ↳ astro-ph.COhep-phPRD(2023)·30 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.