Mon·Feb 5, 2024Monday·February 5, 2024

1. 01*

   Swamplandish Unification of the Dark Sector

   Cumrun Vafa🇺🇸

   We provide a short overview of recent progress made in our understanding of the dark sector based on the Swampland program which in turn is rooted in lessons from string theory. We explain how the existence of one extra mesoscopic dimension (the ``dark dimension") in the micron range emerges and how this can lead to a unification of the dark energy and dark matter. In particular the smallness of the dark energy leads to the prediction of the existence of a tower of weakly interacting light particles which can naturally play the role of dark matter. Moreover this unifies dark matter with gravity as dark matter ends up being excitations of graviton in the dark dimension. We also explain how in combination with other Swampland principles one finds an explanation of the ``why now" and the ``cosmological coincidence" problems. This model is consistent with the cosmological bounds as well as the Newton's inverse square law, but makes predictions which differ from $\Lambda$CDM. It also gives rise to an appealing picture of hierarchy of scales in particle physics pegged to the dark energy, including a possible origin of the electroweak hierarchy and the prediction of masses of QCD axion and sterile neutrinos both in the 1-10 meV range. This review is intended for a broad audience of high energy theorists and cosmologists without prior knowledge of string theory and it explains the motivations and predictions of this program in a non-technical form.

   hep-phgr-qchep-th36 citations
2. 02*

   Upper Limits on the Cosmic Neutrino Background from Cosmic Rays

   Mar Císcar-Monsalvatje🇩🇪 · Gonzalo Herrera🇺🇸 · Ian M. Shoemaker🇺🇸

   Extragalactic and galactic cosmic rays scatter with the cosmic neutrino background during propagation to Earth, yielding a flux of relic neutrinos boosted to larger energies. If an overdensity of relic neutrinos is present in galaxies, and neutrinos are massive enough, this flux might be detectable by high-energy neutrino experiments. For a lightest neutrino of mass $m_{\nu }\sim 0.1$ eV, we find an upper limit on the local relic neutrino overdensity of $\sim 10^{13}$ and an upper limit on the relic neutrino overdensity at TXS 0506+056 of $\sim 10^{10}$. Future experiments like GRAND or IceCube-Gen2 could improve these bounds by orders of magnitude.

   hep-phastro-ph.COPRD(2024)·32 citations
3. 03*

   Connection of event shapes to the heavy-flavor baryon enhancement

   Róbert Vértesi🇭🇺 · Zoltán Varga🇭🇺

   Recent results from ALICE and CMS show a low-transverse-momentum enhancement of charm baryon-to-meson production ratios over model predictions based on $e^{+}{e}^{-}$ collisions. This new development challenges the universality of fragmentation. We studied the charm-baryon enhancement in collision events generated by PYTHIA 8 and applied a color-reconnection model beyond leading color approximation. We proposed a measurement method based on several event-activity classifiers, to identify the origin of the charm-baryon enhancement. In this work we extend our studies to a new event classifier, flattenicity, that considers a broad pseudorapidity range. We have also studied the role of isospin and strangeness by comparing the production of different charmed baryons. The observables we explored provide a unique opportunity in the upcoming measurements from the high-luminosity LHC Run 3 period to better understand heavy-flavor fragmentation mechanisms, and will help the further development of models.

   hep-ph2 citations
4. 04*

   Single production of vectorlike quarks with charge 5/3 at the 14 TeV LHC

   Yao-Bei Liu🇨🇳 · Bo Hu🇨🇳 · Chao-Zheng Li🇨🇳

   Vectorlike quarks have been predicted in many new physics scenarios beyond the Standard Model (SM), which can have sizable couplings to first generation quarks without conflicting with current experimental constraints. In a framework of the SM simply extended by an SU(2) doublet $\left(X,T\right)$ including a vectorlike quark $X$~(VLQ-$X$), with electric charge $|Q_X|=5/3$, we investigate the single production of the VLQ-$X$ induced by the couplings between the VLQ-$X$ with the first and the third generation quarks at the Large Hadron Collider (LHC) Run-III and High-Luminosity LHC (HL-LHC) operating at $\sqrt{s}=14$~TeV. The signal is searched in events including same-sign dileptons (electrons or muons), one $b$-tagged jet and missing energy, where the X quark is assumed to decay into a top quark and a W boson, both decaying leptonically. After a rapid simulation of signal and background events, the 95\% CL exclusion limits and the $5\sigma$ discovery reach are respectively obtained at the 14 TeV LHC with an integrated luminosity of 300 and 3000 fb${}^{-1}$, respectively.

   hep-phNPB(2024)·12 citations
5. 05*

   Vector Dark Matter with Higgs Portal in Type II Seesaw framework

   Nandini Das🇮🇳 · Tapoja Jha🇮🇳 · Dibyendu Nanda🇰🇷

   We study the phenomenology of a vector dark matter (VDM) in a $U(1{)}_X$ gauged extension of the Standard Model (SM) which is connected to the type II seesaw framework via the Higgs portal. When this $U(1{)}_X$ symmetry is spontaneously broken by the vacuum expectation value (VEV) of a complex scalar singlet, the gauge boson $Z^{\prime }$ becomes massive. The stability of the dark matter (DM) is ensured by the introduction of an exact charge conjugation symmetry. On the other hand, the $SU(2{)}_L$ triplet scalar generates light neutrino masses through the type II seesaw mechanism. We have studied the phenomenology of the usual WIMP DM considering all possible theoretical and experimental constraints that are applicable. Due to the presence of triplet scalar, our scenario can accommodate the observed $2\sigma$ deviation in $h\to Z\gamma$ decay. We have also briefly discussed the possibility of non-thermal production of DM from the decay of the same complex scalar that is responsible for the breaking of this $U(1{)}_X$ symmetry.

   hep-phPRD(2024)·9 citations
6. 06*

   Weak decays of the triply heavy baryons in the three-quark picture with the light-front quark model

   Fang Lu🇨🇳 · Hong-Wei Ke🇨🇳 · Xiao-Hai Liu🇨🇳

   We investigate the weak decays of the triply heavy baryon ${\Omega }_{QQQ}$ in the light-front quark model. Since ${\Omega }_{QQQ}$ consists of three indistinguishable identical heavy quarks, the commonly adopted quark-diquark picture does not seem to be valid anymore. Instead, we employ the three-quark picture for baryons where the three quarks are regarded as individual quarks. We calculate the hadronic form factors for the transitions and give predictions for the decay widths of the semi-leptonic decay modes ${\Omega }_{ccc}\to {\Xi }_{cc}/{\Omega }_{cc}+l{\bar{\nu }}_l$, ${\Omega }_{bbb}\to {\Xi }_{bb}+l{\bar{\nu }}_l$ and the non-leptonic decay modes ${\Omega }_{ccc}\to {\Xi }_{cc}/{\Omega }_{cc}+M$, ${\Omega }_{bbb}\to {\Xi }_{bb}+M$. Our study can be a guide for future experiments to discover the triply heavy baryons.

   hep-phEPJC(2024)·6 citations
7. 07*

   Dark Matter-Electron Scattering Search Using Cryogenic Light Detectors

   V. Zema🇩🇪 · P. Figueroa🇩🇪 · G. Angloher🇩🇪 · M. R. Bharadwaj🇩🇪 · T. Frank🇩🇪 · M. N. Hughes🇩🇪 · M. Kellermann🇩🇪 · F. Pröbst🇩🇪 · K. Schäffner🇩🇪 · K. Shera🇩🇪 · M. Stahlberg🇩🇪

   The CSC (cryogenic scintillating calorimeter) technology devoted to rare event searches is reaching the sensitivity level required for the hunt of dark matter-electron scatterings. Dark matter-electron interactions in scintillating targets are expected to stimulate the emission of single photons, each of energy equal to the target electronic band gap. The electronic band gap in scintillators like NaI/GaAs is of O(eV). The search for this signal can be done by an array of cryogenic light detectors with eV/sub-eV energy resolution. In this work, we describe the detection principle, the detector response and the envisioned detector design to search for dark matter interacting with electrons via the measurement of the scintillation light at millikelvin. First sensitivity projections are provided, which show the potential of this research.

   hep-phastro-ph.COhep-exPRD(2024)·13 citations
8. 08*

   $e^{+}{e}^{-}\to l^{+}{l}^{-}$ scattering at finite temperature in the presence of a classical background magnetic field

   D. S. Cabral🇧🇷 · A. F. Santos🇧🇷

   In this work the $e^{+}{e}^{-}\to l^{+}{l}^{-}$ scattering process is investigated. The cross-section is calculated considering three different effects: temperature, external magnetic field and chemical potential. The effect due to an external field is inserted into the problem through a redefinition of the fermionic field operator. Effects due to temperature and chemical potential are introduced using the Thermo Field Dynamics formalism.

   hep-phhep-thEur.Phys.J.Plus(2024)·9 citations
9. 09*

   Transverse $\Lambda$ polarization in unpolarized $pp\to \mathrm{jet}{\Lambda }^{\uparrow }X$

   Umberto D'Alesio🇮🇹 · Leonard Gamberg🇺🇸 · Francesco Murgia🇮🇹 · Marco Zaccheddu🇺🇸

   In this Letter, we investigate the spontaneous transverse polarization of $\Lambda$ hyperons produced in unpolarized $pp$ collisions inside a jet, by adopting a TMD approach where transverse momentum effects are included only in the fragmentation process. We will present predictions based on the parametrizations of the $\Lambda$ polarizing fragmentation function as extracted from fits to Belle $e^{+}{e}^{-}$ data. These estimates will be compared against preliminary STAR data. We will then be able to explore the universality properties of the quark polarizing fragmentation function and, for the first time, the role of its gluon counterpart.

   hep-phPLB(2024)·8 citations
10. 10*

    Probing the Sterile Neutrino Dipole Portal with SN1987A and Low-Energy Supernovae

    Garv Chauhan🇺🇸 · Shunsaku Horiuchi🇺🇸 · Patrick Huber🇺🇸 · Ian M. Shoemaker🇺🇸

    BSM electromagnetic properties of neutrinos may lead to copious production of sterile neutrinos in the hot and dense core of a core-collapse supernova. In this work, we focus on the active-sterile transition magnetic moment portal for heavy sterile neutrinos. Firstly, we revisit the SN1987A cooling bounds for dipole portal using the integrated luminosity method, which yields more reliable results (especially in the trapping regime) compared to the previously explored via emissivity loss, aka the Raffelt criterion. Secondly, we obtain strong bounds on the dipole coupling strength reaching as low as $10^{-11}{\text{ GeV}}^{-1}$ from energy deposition, i.e., constrained from the observation of explosion energies of underluminous Type IIP supernovae. In addition, we find that sterile neutrino production from Primakoff upscattering off of proton dominates over scattering off of electron for low sterile neutrino masses.

    hep-phPRD(2024)·25 citations
11. 11*

    Baryon Spin and Emergent Hadron Mass

    Peng Cheng🇨🇳

    This thesis describes the use of Dyson-Schwinger equations (DSEs) to study baryon bound states in QCD. In this work, octet baryon axial form factors are calculated using a symmetry-preserving treatment of a vector $\times$ vector contact interaction (SCI). The baryons are considered as quark-plus-interacting-diquark bound states, whose structure (wave function) is obtained by solving a Poincaré-covariant Faddeev equation. Since it preserves symmetries, all consequences of partial conservation of the axial current are manifest. For instance, one finds that octet baryon axial properties are consistent with only minor violations of SU(3)-flavour symmetry, being interpreted as a dynamical consequence of emergent hadron mass (EHM). Considering neutral axial currents, the SCI delivers predictions for the flavour separation of octet baryon axial charges and, consequently, produces values for the associated SU(3) singlet, triplet, and octet axial charges. The results indicate that, at the hadron scale ${\zeta }_{\mathcal{H}}$, valence degrees of freedom carry approximately $50\%$ of an octet baryon's total spin. Proton structure is one of the principal topics in hadron physics. Its study is expected to reveal key features of both the origin of mass and strong interaction dynamics. This work therefore extended the above analyses to an examination of in-proton parton helicity (spin) distribution functions (DFs). Using Ansätze for hadron-scale proton polarised valence quark DFs, predictions are delivered for all proton polarised DFs at the measurement scale ${\zeta }_{\mathrm{C}}^2=3$GeV${}^2$. The pointwise behaviour of the predicted DFs and, consequently, their moments, shows good agreement with results inferred from data. Based on these results, one finds that experimental measurements of the proton flavour-singlet axial charge should return a value $a_0^{\mathrm{E}}({\zeta }_{\mathrm{C}})=0.35(2)$.

    hep-phhep-exhep-latnucl-ex+10 citations
12. 12*

    Transverse momentum moments

    Oscar del Rio🇪🇸 · Alexei Prokudin🇺🇸 · Ignazio Scimemi🇪🇸 · Alexey Vladimirov🇪🇸

    We establish robust relations between Transverse Momentum Dependent distributions (TMDs) and collinear distributions. We define weighted integrals of TMDs that we call Transverse Momentum Moments (TMMs) and prove that TMMs are equal to collinear distributions evaluated in some minimal subtraction scheme. The conversion to the modified minimal subtraction ($\overline{MS}$) scheme, can be done by a calculable factor, which we derive up to three loops for some cases. We discuss in detail the zeroth, the first, and the second TMMs and provide phenomenological results for them based on the current extractions of TMDs. The results of this paper open new avenues for theoretical and phenomenological investigation of the three-dimensional and collinear hadron structures.

    hep-phhep-exhep-thnucl-thPRD(2024)·29 citations
13. 13*

    Indirect Searches for Dark Photon-Photon Tridents in Celestial Objects

    Tim Linden🇸🇪 · Thong T. Q. Nguyen🇸🇪 · Tim M. P. Tait🇺🇸

    We model and constrain the unique indirect detection signature produced by dark matter particles that annihilate through a $U(1)$ gauge symmetry into dark photons that subsequently decay into three-photon final states. We focus on scenarios where the dark photon is long-lived, and show that $\gamma$-ray probes of celestial objects can set strong constraints on the dark matter/baryon scattering cross section that in many cases surpass the power of current direct detection constraints, and in some cases even peer into the neutrino fog.

    hep-phastro-ph.COastro-ph.HEJCAP(2026)·50 citations
14. 14*

    Gauge-Invariant Quantum Fields

    Andrea Quadri (INFN, Sez. di Milano)🇮🇹

    Gauge-invariant quantum fields are constructed in an Abelian power-counting renormalizable gauge theory with both scalar, vector and fermionic matter content. This extends previous results already obtained for the gauge-invariant description of the Higgs mode via a propagating gauge-invariant field. The renormalization of the model is studied in the Algebraic Renormalization approach. The decomposition of Slavnov-Taylor identities into separately invariant sectors is analyzed. We also comment on some non-renormalizable extensions of the model whose 1-PI Green's functions are the flows of certain differential equations of the homogeneous Euler type, exactly resumming the dependence on a certain set of dim. 6 and dim. 8 derivative operators. The latter are identified uniquely by the condition that they span the mass and kinetic terms in the gauge-invariant dynamical fields. The construction can be extended to non-Abelian gauge groups.

    ↳ hep-thhep-phEPJC(2024)·3 citations
15. 15*

    Strongly coupled gauge theories towards physics beyond the Standard Model

    Jong-Wan Lee🇰🇷

    Strongly coupled gauge theories provide an ultra-violet realization of new physics models for physics beyond the Standard Model of particle physics arising from composite dynamics. Depending on the gauge group and matter content, they are expected to exhibit interesting features and rich phenomenology, similar or dissimilar to QCD, of which model builders and phenomenologists can take advantage. Due to the non-perturbative nature of these theories, first principles lattice calculations are essential to test the validity of composite models and provide theoretical inputs, that are otherwise unattainable, to the experimental searches for new physics. In this contribution, we will review recent efforts in the non-perturbative lattice studies of strongly coupled gauge theories other than QCD in the context of physics beyond the Standard Model by focusing on technical developments and new results.

    ↳ hep-lathep-phhep-thPoS(2024)·4 citations
16. 16*

    The worldvolume fermion as baryon in holographic QCD with instanton

    Si-wen Li🇨🇳 · Hao-qian Li🇨🇳 · Yi-peng Zhang🇨🇳

    In this work, we investigate the worldvolume fermion on the flavor brane in the D0-D4/D8 model which is holographically equivalent to the four-dimensional QCD with instantons, or equivalently with a theta angle. The action for the worldvolume fermion is obtained by the T-duality rules in string theory and we accordingly derive its effectively five-dimensional, canonical four-dimensional forms by using the systematical dimensional reduction and decomposition of spinor. Afterwards, we employ the AdS/CFT dictionary in order to evaluate the two-point correlation function as the spectral function for the worldvolume fermion and interpret the fermion as baryon by analyzing its quantum number with the baryon vertex in holography. In this sense, the interacted action involving the worldvolume fermion and gauge field on the flavor brane are finally derived in holography which describes the various interaction of meson and baryon with instantons in large-N limit. Therefore, this work provides a holographic picture to describe baryon and its interactions based on string theory, in particular, in the presence of instantons or a theta angle.

    ↳ hep-thhep-phCommun.Theor.Phys.(2025)·5 citations
17. 17*

    ATLAS Run 2 searches for electroweak production of supersymmetric particles interpreted within the pMSSM

    ATLAS Collaboration

    A summary of the constraints from searches performed by the ATLAS Collaboration for the electroweak production of charginos and neutralinos is presented. Results from eight separate ATLAS searches are considered, each using 140 fb${}^{-1}$ of proton-proton data at a centre-of-mass energy of $\sqrt{s}$=13 TeV collected at the Large Hadron Collider during its second data-taking run. The results are interpreted in the context of the 19-parameter phenomenological minimal supersymmetric standard model, where R-parity conservation is assumed and the lightest supersymmetric particle is assumed to be the lightest neutralino. Constraints from previous electroweak, flavour and dark matter related measurements are also considered. The results are presented in terms of constraints on supersymmetric particle masses and are compared with limits from simplified models. Also shown is the impact of ATLAS searches on parameters such as the dark matter relic density and the spin-dependent and spin-independent scattering cross-sections targeted by direct dark matter detection experiments. The Higgs boson and Z boson `funnel regions', where a low-mass neutralino would not oversaturate the dark matter relic abundance, are almost completely excluded by the considered constraints. Example spectra for non-excluded supersymmetric models with light charginos and neutralinos are also presented.

    ↳ hep-exhep-phJHEP(2024)·41 citations
18. 18*

    Testing $\alpha$-attractor quintessential inflation against CMB and low-redshift data

    William Giarè🇬🇧 · Eleonora Di Valentino🇬🇧 · Eric V. Linder🇺🇸 · Enrico Specogna🇬🇧

    Due to universality and attractor properties, $\alpha$-attractor quintessential inflation establishes direct relations between inflationary observables such as the scalar tilt $n_s$ and the tensor-to-scalar ratio $r$, and late-time dark energy equation of state parameters $w_0$ and $w_a$. In this work, we examine three different physically motivated regimes, considering complete freedom in the parameter $\alpha$, models inspired by supergravity where $\alpha$ takes on values up to $\alpha =7/3$, and Starobinsky inflation ($\alpha =1$). We investigate the consistency and constraints imposed by Cosmic Microwave Background measurements from the Planck satellite, B-mode polarization data from the BICEP/Keck collaboration, and low-redshift observations. Additionally, we consider small-scale CMB measurements released by the Atacama Cosmology Telescope, which give results approaching the Harrison-Zel'dovich spectrum ($n_s\approx 1$). Here $\alpha$-attractors lead to an improved fit over $\Lambda$CDM. For the large-scale CMB measurements, $\alpha \gtrsim 2$ models can provide equally good fits as $\Lambda$CDM.

    ↳ astro-ph.COgr-qchep-phPhys.Dark Univ.(2024)·18 citations
19. 19*

    Relativistic Dissipative Magnetohydrodynamics from the Boltzmann equation for a two-component gas

    Khwahish Kushwah🇧🇷 · Gabriel S. Denicol🇧🇷

    We derive the equations of motion of relativistic magnetohydrodynamics, as well as microscopic expressions for all of its transport coefficients, from the Boltzmann equation using the method of moments. In contrast to reference Phys. Rev. D 98(7) 2018, where a single component gas was considered, we perform our derivation for a locally neutral fluid composed of two massless particle species with opposite charges. We demonstrate that the magnetohydrodynamical equations of motion become dramatically different for this more realistic system. The shear-stress tensor no longer obeys a single differential equation; it breaks into three non-degenerate components with respect to the magnetic field, each evolving according to different dynamical equations. For large magnetic fields, we further show that the solution of this theory displays oscillatory behaviour that can no longer be described by an Israel-Stewart-like theory. Finally, we investigate the derived equations in a Bjorken flow scenario.

    ↳ nucl-thastro-ph.HEhep-phPRD(2024)·14 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.