Wed·Jun 28, 2023Wednesday·June 28, 2023

1. 01*

   Supernovae and superbursts by dark matter clumps

   Nirmal Raj🇮🇳

   Cosmologies in which dark matter clumps strongly on small scales are unfavorable to terrestrial detectors that are as yet unexposed to the clumps. I show that sub-hectometer clumps could trigger thermonuclear runaways by scattering on nuclei in white dwarf cores (carbon and oxygen) and neutron star oceans (carbon), setting off Type Ia-like supernovae and x-ray superbursts respectively. I consider two scenarios: ``dark clusters" that are essentially microhalos, and ``long-range dark nuggets", essentially macroscopic composites, with long-range Yukawa baryonic interactions that source the energy for igniting explosions. I constrain dark clusters weighing between the Planck mass and asteroid masses, and long-range dark nuggets over a wider mass range spanning forty orders of magnitude. These limits greatly complement searches I had co-proposed in 2109.04582 for scattering interactions of dark clumps in neutron stars, cosmic rays, and pre-historic minerals.

   hep-phastro-ph.HEhep-exPRD(2024)·16 citations
2. 02*

   Thermodynamics of oscillating neutrinos

   Lucas Johns🇺🇸

   The title theory is formulated. It entails a quantum-coherent variant of the Fermi-Dirac distribution and casts new light on neutrino oscillations. It might enable the incorporation of neutrino mixing into the modeling of core-collapse supernovae and neutron star mergers.

   hep-phastro-ph.HEPRD(2025)·37 citations
3. 03*

   Probing New Physics with ${\mu }^{+}{\mu }^{-}\to bs$ at a Muon Collider

   Wolfgang Altmannshofer🇺🇸 · Sri Aditya Gadam🇺🇸 · Stefano Profumo🇺🇸

   We show that bottom-strange production at a high-energy muon collider, ${\mu }^{+}{\mu }^{-}\to bs$, is a sensitive probe of new physics. We consider the full set of four-fermion contact interactions that contribute to this process at dimension 6, and discuss the complementarity of a muon collider and of the study of rare $B$ meson decays that also probe said new physics. If a signal were to be found at a muon collider, the forward-backward asymmetry of the $b$-jet provides diagnostics about the underlying chirality structure of the new physics. In the absence of a signal at a center of mass energy of $10$~TeV, ${\mu }^{+}{\mu }^{-}\to bs$ can indirectly probe new physics at scales close to $100$~TeV. We also discuss the impact that beam polarization has on the muon collider sensitivity performance.

   hep-phPRD(2023)·28 citations
4. 04*

   Collinear matching for next-to-leading power transverse-momentum distributions

   Simone Rodini🇫🇷 · Alessio Carmelo Alvaro🇮🇹 · Barbara Pasquini🇮🇹

   Phenomenological studies of transverse momentum dependent (TMD) parton distributions rely on the expansion in small values of the transverse separation of fields, where TMD parton distributions match onto collinear parton distribution functions. In this work, we derive this expansion at tree-level for the genuine next-to-leading power quark-gluon-quark TMDs, taking into account all the target mass corrections. We find that only a limited number of TMD parton distributions exhibit matching to twist-three collinear distributions, leading to a significant simplification in the analysis of the structure functions of semi-inclusive deep inelastic scattering.

   hep-phhep-thPLB(2023)·6 citations
5. 05*

   Pion decay constraints on exotic 17 MeV vector bosons

   Matheus Hostert🇬🇧 · Maxim Pospelov🇺🇸

   We derive constraints on the couplings of light vector particles to all first-generation Standard Model fermions using leptonic decays of the charged pion, ${\pi }^{+}\to e^{+}{\nu }_e{X}_{\mu }$. In models where the net charge to which $X_{\mu }$ couples is not conserved, no lepton helicity flip is required for the decay to happen, enhancing the decay rate by factors of $O(m_{\pi }^4/m_e^2{m}_X^2)$. A past search at the SINDRUM-I spectrometer severely constrains this possibility. In the context of the hypothesized $17$ MeV particle proposed to explain anomalous ${}^8$Be, ${}^4$He, and ${}^{12}$C nuclear transitions claimed by the ATOMKI experiment, this limit rules out vector-boson explanations and poses strong limits on axial-vector ones.

   hep-phhep-exPRD(2023)·28 citations
6. 06*

   Complementary constraints on $Zb\bar{b}$ couplings at the LHC

   Fady Bishara🇩🇪 · Zhuoni Qian🇨🇳

   We propose a new strategy to probe the $Z$ boson couplings to bottom and charm quarks at the LHC. In this work we mainly focus on the case of bottom quarks. Here, the $Z$ boson is produced in association with two $b$-jets and decays to electrons or muons. In this final state, tagging the charge of the $b$-jets allows us to measure the charge asymmetry and thus to directly probe the $Zb\bar{b}$ couplings. The leptonic final state not only allows us to cleanly reconstruct the $Z$ boson but also to mitigate the otherwise overwhelming backgrounds. Furthermore, while LEP could only scan a limited range of dilepton invariant masses, there is no such limitation at the LHC. Consequently, this allows us to make full use of the interference between the amplitudes mediated by a $Z$ boson and a photon. Using the full high-luminosity LHC dataset of $3{\text{ab}}^{-1}$ and with the current flavor and charge-tagging capabilities would allow us to reject the wrong-sign right-handed coupling solution by 4$\sigma$. Further improving the charge-tagging efficiency would disfavor it by 6$\sigma$.

   hep-phhep-exJHEP(2023)·2 citations
7. 07*

   Study of Baryon Number Transport Dynamics and Strangeness Conservation Effects Using $\Omega$-hadron Correlations

   Weijie Dong🇨🇳 · Xiaozhou Yu🇨🇳 · Siyuan Ping🇨🇳 · Xiatong Wu🇺🇸 · Gang Wang🇺🇸 · Huan Zhong Huang🇺🇸 · Zi-Wei Lin🇺🇸

   In nuclear collisions at RHIC energies, an excess of $\Omega$ hyperons over $\bar{\Omega }$ is observed, indicating that $\Omega$ carries a net baryon number despite $s$ and $\bar{s}$ quarks being produced in pairs. The baryon number in $\Omega$ could have been transported from the incident nuclei and/or produced in baryon-pair production of $\Omega$ with other types of anti-hyperons, such as $\bar{\Xi }$. To investigate these two scenarios, we propose to measure correlations between $\Omega$ and $K$, as well as between $\Omega$ and anti-hyperons. We will use two versions, the default and string-melting, of a multiphase transport (AMPT) model to illustrate the method to measure the correlation and to demonstrate the general shape of the correlation. We will present the $\Omega$-hadron correlations from simulated $\mathrm{Au}$+$\mathrm{Au}$ collisions at $\sqrt{s_{NN}}=7.7$ and $14.6\mathrm{GeV}$, and discuss the dependence on collision energy and on the hadronization scheme in these two AMPT versions. These correlations can be used to explore the mechanism of baryon number transport and the effects of baryon number and strangeness conservation in nuclear collisions.

   hep-phnucl-thNucl.Sci.Tech.(2024)·8 citations
8. 08*

   Baryogenesis via flavoured leptogenesis in a minimal type-II seesaw model

   Sreerupa Chongdar🇮🇳 · Sasmita Mishra🇮🇳

   We study baryogenesis via leptogenesis in an extension of the Standard Model by adding one right-handed neutrino and one triplet scalar. These heavy particles contribute to the generation of tiny neutrino mass through seesaw mechanism. The contribution of the heavy particles to the neutrino masses is inversely proportional to their corresponding masses. Considering leptogenesis is achieved by the decay of the right-handed neutrino, the new source of CP asymmetry comes solely from the decay of the right-handed neutrino with one-loop vertex diagram involving the triplet scalar. The predictiveness of the model is enhanced by introducing Fritzsch-type textures for the neutrino mass matrix and charged lepton mass matrix. We execute the parameter space study following the latest neutrino oscillation data. We study baryogenesis via leptogenesis in the two-flavoured regime, using the zero textures, and show that there is an enhancement in baryon asymmetry as compared to the unflavoured regime. For two-flavour leptogenesis we consider the suitable temperature regime $T\subset \left[10^{10},10^{11}\right]$ GeV. We also study the common correlation of CP violation between low and high-energy regimes using the geometrical description of CP violation in terms of unitarity triangle.

   hep-phNPB(2025)·0 citations
9. 09*

   DGLAP evolution of parton distributions at approximate N${}^3$LO

   Felix Hekhorn🇮🇹 · Giacomo Magni🇳🇱

   We present recent progress towards a global determination of parton distribution functions (PDFs) at approximate N${}^3$LO (aN${}^3$LO) accuracy within the NNPDF framework. We construct a parametrisation of the $\mathcal{O}({\alpha }_s^4)$ QCD splitting functions and anomalous dimensions reproducing all known exact results, estimate the associated missing and incomplete higher order uncertainties (MHOU and IHOU, respectively), and implement it in the open-source DGLAP code EKO enabling PDFs to be evolved at aN${}^3$LO accuracy in the NNPDF fitting framework. We compare aN${}^3$LO calculation of splitting functions with the results of lower perturbative orders and quantify the impact of the various sources of theoretical uncertainties.

   hep-ph21 citations
10. 10*

    Radiative neutrino masses and the Cohen-Kaplan-Nelson bound

    Patrick Adolf🇩🇪 · Martin Hirsch🇪🇸 · Heinrich Päs🇩🇪

    Recently, an increasing interest in UV/IR mixing phenomena has drawn attention to the range of validity of standard quantum field theory. Here we explore the consequences of such a limited range of validity in the context of radiative models for neutrino mass generation. We adopt an argument first published by Cohen, Kaplan and Nelson that gravity implies both UV and IR cutoffs, apply it to the loop integrals describing radiative corrections, and demonstrate that this effect has significant consequences for the parameter space of radiative neutrino mass models.

    hep-phJHEP(2023)·4 citations
11. 11*

    Conformal Symmetry and Effective Potential: I. Vacuum $V_{z,x}$-operation for the Green functions

    I.V. Anikin🇷🇺

    We begin a series of two papers that is devoted to the study of the multi-loop effective potential evolution in ${\phi }^4$-theory using the conformal symmetry. In the first part, we introduce and describe in detail the vacuum $V_{z,x}$-operation ($"V"$ stems from "vacuum", $\{z,x\}$ imply the corresponding coordinates) that transforms the given Green functions to the corresponding vacuum integrations which generate the effective potential. Our operation can be considered as an inverse procedure compared to the Gorishni-Isaev method. To the final goal, it is necessary to introduce also the special treatment of the mass terms as sorts of "interaction" in an asymptotical expansion of the generating functional.

    hep-phhep-thPTEP(2023)·3 citations
12. 12*

    Strange molecular partners of $P_c$ states in $\gamma p\to \varphi p$ reaction

    Shu-Ming Wu🇨🇳 · Fei Wang🇨🇳 · Bing-Song Zou🇨🇳

    Based on the high statistical data of the CLAS Collaboration on $\gamma p\to \varphi p$ reaction in the center-of-mass energy range of 2.2 GeV to 2.8 GeV, we investigate the possible existence of strange molecular partners of $P_c$ states, i.e., $N^{\ast }(2080)$ and $N^{\ast }(2270)$ as $K^{\ast }\Sigma$ and $K^{\ast }{\Sigma }^{\ast }$ molecular states. In addition to the t-channel Pomeron exchange, t-channel meson exchange including pseudo-scalar meson $(\pi ,\eta )$, scalar meson $(\sigma ,a_0(980),f_0(980))$, axial-vector meson $f_1(1285)$, tensor meson $f_2(1270)$, as well as s- and u-channel proton exchange, including s-channel $N^{\ast }(2080)$ and $N^{\ast }(2270)$ states can fit the data very well. The fitted coupling constants of these $N^{\ast }$ molecular states to $p\varphi$ and $\gamma p$ are consistent with the results directly calculated from the relevant hadronic triangle diagrams of the molecular picture.

    hep-phPRC(2023)·18 citations
13. 13*

    All Two-Loop Feynman Integrals for Five-Point One-Mass Scattering

    Samuel Abreu🇨🇭 · Dmitry Chicherin🇫🇷 · Harald Ita🇨🇭 · Ben Page🇨🇭 · Vasily Sotnikov🇨🇭 · Wladimir Tschernow🇩🇪 · Simone Zoia🇮🇹

    We compute the complete set of two-loop master integrals for the scattering of four massless particles and a massive one. Our results are ready for phenomenological applications, removing a major obstacle to the computation of complete next-to-next-to-leading order (NNLO) QCD corrections to processes such as the production of a $H/Z/W$ boson in association with two jets at the LHC. Furthermore, they open the door to new investigations into the structure of quantum-field theories and provide precious analytic data for studying the mathematical properties of Feynman integrals.

    hep-phhep-thPRL(2024)·84 citations
14. 14*

    The total cross section for proton-proton interactions at the FCC

    Per Grafstrom🇮🇹

    The lower and upper limits of the total cross section (${\sigma }_{tot}$) at the projected FCC-hh have been estimated. A lower limit has been estimated using dispersion relations in combination with recent LHC data of ${\sigma }_{tot}$ and the $\rho$-parameter. The upper limit has been estimated using the standard $l{n}^2(s)$ evolution of ${\sigma }_{tot}$. Some models giving values in between those limits are also discussed.

    hep-ph1 citation
15. 15*

    Exploring mixed lepton-quark interactions in non-resonant leptoquark production at the LHC

    João Gonçalves🇵🇹 · António P. Morais🇵🇹 · António Onofre🇵🇹 · Roman Pasechnik🇸🇪

    Searches for new physics (NP) at particle colliders typically involve multivariate analysis of kinematic distributions of final state particles produced in a decay of a hypothetical NP resonance. Since the pair-production cross-sections mediated by such resonances are strongly suppressed by the NP scale, this analysis becomes less relevant for NP searches for masses of the BSM resonance above 1 TeV. On the other hand, $t$-channel processes are less sensitive to the mass of the virtual mediator and therefore larger phase-space can be potentially probed as well as the couplings between the NP particles and the Standard Model fields. The fact that transitions between different generations of quarks and leptons may exist, the potential of the search presented in this article can be used, as a reference guide, to enlarge significantly the scope of searches performed at the LHC to flavour off-diagonal channels, in a theoretically consistent approach. In this work, we study non-resonant production of scalar leptoquarks which have been proposed in the literature to provide a potential avenue for radiative generation of neutrino masses, accommodating as well the existing flavour physics data. Final states involving just two muons at the LHC (${\mu }^{+},{\mu }^{-}$), are used as a well-motivated case study.

    hep-phhep-exJHEP(2023)·4 citations
16. 16*

    Dynamical realization of the small field inflation of Coleman-Weinberg type in the post supercooled universe

    He-Xu Zhang🇨🇳 · Hiroyuki Ishida🇯🇵 · Shinya Matsuzaki🇨🇳

    The small field inflation (SFI) of Coleman-Weinberg (CW) type suffers from precise tuning of the initial inflaton field value to be away from the true vacuum one. We propose a dynamical trapping mechanism to solve this problem: an ultra-supercooling caused by an almost scale-invariant CW potential traps the inflaton at the false vacuum, far away from the true vacuum dominantly created by the quantum scale anomaly, and allows the inflaton to dynamically start the slow-roll down due to a classical explicit-scale breaking effect. To be concrete, we employ a successful CW-SFI model and show that the proposed mechanism works consistently with the observed bounds on the inflation parameters. The proposed new mechanism thus provides new insights for developing small field inflation models.

    hep-phastro-ph.COhep-thPLB(2023)·4 citations
17. 17*

    Mission Target: Tetraquark Mesons of Flavour-Cryptoexotic Type

    Wolfgang Lucha🇦🇹

    Currently, flavour-cryptoexotic tetraquarks form the most common sort of all experimentally established exotic multiquark hadrons. This note points out a few promising concepts that should help improve theoretical (but, for several reasons, not quite straightforward) analyses of such kind of states: among others, their scope of application encompasses the strong interactions in the limit of (arbitrarily) large numbers of colours, and equally analytical and nonperturbative approaches to multiquark states.

    hep-phhep-thnucl-thUniverse(2023)·2 citations
18. 18*

    The $\gamma b\overline{b}$ production via ${\gamma }^{\ast }{\gamma }^{\ast }$ collisions at the ILC and LHC

    Bui Thi Ha Giang🇻🇳

    Taking into account of the mixing of Higgs-radion in the Randall-Sundrum model and the vector anomalous couplings, we investigate the production of $b\overline{b}$ associated with the photon through ${\gamma }^{\ast }{\gamma }^{\ast }$ collisions at the International Linear Collider (ILC) and Large Hadron Collider (LHC). The total cross-section depends strongly on the vacuum expectation value (VEV) of the radion field ${\Lambda }_{\varphi }$, the radion mass $m_{\varphi }$, the parameters of anomalous couplings. The result shows that the total cross-section in $\gamma b\overline{b}$ production at the LHC is much larger than that at the ILC. The production cross-section gives the largest value at the dominated state, $m_{\varphi }=m_h=125$ GeV.

    hep-phInt.J.Mod.Phys.A(2025)·0 citations
19. 19*

    Bubbletrons: Ultrahigh-Energy Particle Collisions and Heavy Dark Matter at Phase Transitions

    Iason Baldes🇫🇷 · Maximilian Dichtl🇫🇷 · Yann Gouttenoire🇮🇱 · Filippo Sala🇮🇹

    We initiate the study of `bubbletrons', by which we mean ultra-high-energy collisions of the particle shells that generically form at the walls of relativistic bubbles in cosmological first-order phase transitions (PT). As an application, we calculate the maximal dark matter mass $M_{DM}$ that bubbletrons can produce in a $U(1)$ gauge PT, finding $M_{DM}\sim 10^5/10^{11}/10^{15}$ GeV for PT scales $v_{\varphi }\sim 10^{-2}/10^3/10^9$ GeV. Bubbletrons realise a novel link between ultra-high-energy phenomena and gravitational waves (GW) sourced at the PT, from nanohertz to megahertz frequencies.

    hep-phastro-ph.COPRL(2025)·55 citations
20. 20*

    Collider constraints on massive gravitons coupling to photons

    David d'Enterria (CERN)🇨🇭 · Malak Ait Tamlihat (Mohammed V University in Rabat)🇲🇦 · Laurent Schoeffel (CEA)🇫🇷 · Hua-Sheng Shao (LPTHE)🇫🇷 · Yahya Tayalati (Mohammed V University in Rabat)🇲🇦

    We study the discovery potential of massive graviton-like spin-2 particles coupled to standard model fields, produced in photon-photon collisions at the Large Hadron Collider (LHC) as well as in electron-positron ($e^{+}{e}^{-}$) collisions, within an effective theory with and without universal couplings. Our focus is on a massive graviton G coupled to the electromagnetic field, which decays via $\mathrm{G}\to \gamma \gamma$ and leads to a resonant excess of diphotons over the light-by-light scattering continuum at the LHC, and of triphoton final states at $e^{+}{e}^{-}$ colliders. Based on similar searches performed for pseudoscalar axion-like particles (ALPs), and taking into account the different cross sections, $\gamma \gamma$ partial widths, and decay kinematics of the pseudoscalar and tensor particles, we reinterpret existing experimental bounds on the ALP-$\gamma$ coupling into G-$\gamma$ ones. Using the available data, exclusion limits on the graviton-photon coupling are set down to $g_{\mathrm{G}\gamma \gamma }\approx 1$--0.05~TeV${}^{-1}$ for masses $m_{\mathrm{G}}\approx 100$~MeV--2~TeV. Such bounds can be improved by factors of 100 at Belle~II in the low-mass region, and of 4 at the HL-LHC at high masses, with their expected full integrated luminosities.

    hep-phhep-exnucl-exnucl-thPLB(2023)·24 citations
21. 21*

    Parity doublet model for baryon octets: diquark classifications and mass hierarchy based on the quark-line diagram

    Takuya Minamikawa🇯🇵 · Bikai Gao🇯🇵 · Toru kojo🇯🇵 · Masayasu Harada🇯🇵

    We construct ${\mathrm{SU}(3)}_{\mathrm{L}}\otimes {\mathrm{SU}(3)}_{\mathrm{R}}$ invariant parity doublet models within the linear realization of the chiral symmetry. Describing baryons as the superposition of linear representations should be useful description for transitions toward the chiral restoration. The major problem in the construction is that there are much more chiral representations for baryons than in the two-flavor cases. To reduce the number of possible baryon fields, we introduce a hierarchy between representations with good or bad diquarks (called soft and hard baryon representations, respectively). We use $(3,\bar{3})+(\bar{3},3)$ and $(8,1)+(1,8)$ as soft to construct a chiral invariant Lagrangian, while the $(3,6)+(6,3)$ representations are assumed to be integrated out, leaving some effective interactions. The mass splitting associated with the strange quark mass is analyzed in the first and second order in the meson fields $M$ in $(3,\bar{3})+(\bar{3},3)$ representations. We found that the chiral ${\mathrm{SU}(3)}_L\otimes {\mathrm{SU}(3)}_R$ constraints are far more restrictive than the ${\mathrm{SU}(3)}_V$ constraints used in conventional models for baryons. After extensive analyses within $(3,\bar{3})+(\bar{3},3)$ and $(8,1)+(1,8)$ models, we found that models in the first order of $M$ do not reproduce the mass hierarchy correctly, although the {\GO} is satisfied. In the second order, the masses of the positive parity channels are reproduced well up to the first radial excitations, while some problem in the mass ordering remains in a negative parity channel. Apparently the baryon dynamics is not well-saturated by just $(3,\bar{3})+(\bar{3},3)$ and $(8,1)+(1,8)$ representations, as indicated by the necessity of terms higher order in $M$.

    hep-phPRD(2023)·15 citations
22. 22*

    New physics in multi-electron muon decays

    Matheus Hostert🇬🇧 · Tony Menzo🇺🇸 · Maxim Pospelov🇺🇸 · Jure Zupan🇺🇸

    We study the exotic muon decays with five charged tracks in the final state. First, we investigate the Standard Model rate for ${\mu }^{+}\to 3e^{+}2e^{-}2\nu$ ($B=4.0\times 10^{-10})$ and find that the Mu3e experiment should have tens to hundreds of signal events per $10^{15}$ ${\mu }^{+}$ decays, depending on the signal selection strategy. We then turn to a neutrinoless ${\mu }^{+}\to 3e^{+}2e^{-}$ decay that may arise in new-physics models with lepton-flavor-violating effective operators involving a dark Higgs $h_d$. Following its production in ${\mu }^{+}\to e^{+}{h}_d$ decays, the dark Higgs can undergo a decay cascade to two $e^{+}{e}^{-}$ pairs through two dark photons, $h_d\to {\gamma }_d{\gamma }_d\to 2(e^{+}{e}^{-})$. We show that a ${\mu }^{+}\to 3e^{+}2e^{-}$ search at the Mu3e experiment, with potential sensitivity to the branching ratio at the $O(10^{-12})$ level or below, can explore new regions of parameter space and new physics scales as high as $\Lambda \sim 10^{15}$ GeV.

    hep-phhep-exJHEP(2023)·14 citations
23. 23*

    Foliation, topology and nucleon charge profiles in hypersphere soliton model

    Soon-Tae Hong🇰🇷

    In the hypersphere soliton model (HSM), we study the geometrical inner structures and the ensuing charge distributions of the nucleons by exploiting the aspect of the HSM where the hypersphere soliton is described by an extended object possessing the parameter $\lambda$ $(0\le \lambda <\infty )$ which corresponds to the radial distance from the center of $S^3$ to the foliation leaves of the hypersphere soliton. To do this, we investigate the foliation and topology related with geometry on a hypersphere described by $(\mu ,\theta ,\varphi )$. Exploiting the so-called scanning algorithm we study geometrical relations between spherical shell foliation leave on a northern hemi-hypersphere $S_{+}^3$ and that on a flat equatorial solid sphere $E^3$ which contains the center of $S^3$. We then elucidate the physical meaning of $\mu$ in $S^3$ of radius $\lambda$ by showing that $\mu$ plays the role of an auxiliary angle to fix the radius $\lambda \sin \mu$ of the $S^2$ spherical shell sharing the center of $S^3(=S^2\times S^1)$, at a given angle $\mu$. Next, using the charge density profiles of nucleons with $\mu$ dependence, we construct the nucleon fractional charges of spherically symmetric and nontrivial distributions. In the HSM we note that the proton and neutron charges do not leak out from the hypersphere soliton, and the positive and negative charges in the neutron are confined inside and outside its core, respectively. Explicitly we predict the fractional volumes and charges of the neutron. The proton and neutron are shown to be described by a topological structure of two Hopf-linked Möbius strip type twist circles in $S^3$. We also note that the characteristic ratio of the hypersphere volume to the corresponding solid sphere one is given by a geometrical invariant related with hyper-compactness.

    hep-phPhys.Scripta(2024)·0 citations
24. 24*

    Refractive neutrino masses, ultralight dark matter and cosmology

    Manibrata Sen🇩🇪 · Alexei Y. Smirnov🇩🇪

    We consider in detail a possibility that the observed neutrino oscillations are due to refraction on ultralight scalar boson dark matter. We introduce the refractive mass squared, ${\tilde{m}}^2$, and study its properties: dependence on neutrino energy, state of the background, etc. If the background is in a state of cold gas of particles, ${\tilde{m}}^2$ shows a resonance dependence on energy. Above the resonance ($E\gg E_R$), we find that ${\tilde{m}}^2$ has the same properties as usual vacuum mass squared. Below the resonance, ${\tilde{m}}^2$ decreases with energy, which (if realised) allows us to avoid the cosmological bound on the sum of neutrino masses. Also, ${\tilde{m}}^2$ may depend on time. We consider the validity of the results: effects of multiple interactions with scalars, and modification of the dispersion relation. We show that for values of parameters of the system required to reproduce the observed neutrino masses, perturbativity is broken at low energies, which border above the resonance. If the background is in the state of coherent classical field, the refractive mass does not depend on energy explicitly but may show time dependence. It coincides with the refractive mass in a cold gas at high energies. The refractive nature of neutrino mass can be tested by searches of its dependence on energy and time.

    hep-phastro-ph.COJCAP(2024)·41 citations
25. 25*

    $SU(2{)}_L$ triplet scalar as the origin of the 95 GeV excess?

    Saiyad Ashanujjaman🇮🇳 · Sumit Banik🇨🇭 · Guglielmo Coloretti🇨🇭 · Andreas Crivellin🇨🇭 · Bruce Mellado🇿🇦 · Anza-Tshilidzi Mulaudzi🇿🇦

    We explore the possibility that an $SU(2{)}_L$ triplet scalar with hypercharge $Y=0$ is the origin of the $95$GeV diphoton excess. For a small mixing angle with the Standard Model Higgs, its neutral component has naturally a sizable branching ratio to $\gamma \gamma$ such that its Drell-Yan production via $pp\to W^{\ast }\to H{H}^{\pm }$ is sufficient to obtain the desired signal strength, where $H^{\pm }$ is the charged Higgs component of the triplet. The predictions of this setup are: 1) The $\gamma \gamma$ signal has a $p_T$ spectrum different from gluon fusion but similar to associated production. 2) Photons are produced in association with tau leptons and jets, but generally do not fall into the vector-boson fusion category. 3) The existence of a charged Higgs with $m_{H^{\pm }}\approx (95\pm 5)$GeV leading to $\sigma (pp\to \tau \tau \nu \nu )\approx 0.4$pb, which is of the same level as the current limit and can be discovered with Run 3 data. 4) A positive definite shift in the $W$ mass as suggested by the current global electroweak fit.

    hep-phhep-exPRD(2023)·68 citations
26. 26*

    Searches for supersymmetric particles with prompt decays with the ATLAS detector

    Francesco Giuseppe Gravili (on behalf of the ATLAS Collaboration)🇮🇹

    Supersymmetry (SUSY) provides elegant solutions to several problems in the Standard Model and searches for SUSY particles are an important component of the LHC physics program. The latest results from electroweak and strong SUSY searches are reported here, conducted by the ATLAS experiment at the CERN LHC. The searches target multiple final states and different assumptions about the decay mode of the produced SUSY particles, including searches for both R-parity conserving models and R-parity violating models, and their possible connections with the recent observation of the flavour and muon g-2 anomalies. The talk will also highlight the employment of novel analysis techniques, including advanced machine learning techniques and special object reconstruction, that are necessary for many of these analyses to extend the sensitivity reach to challenging regions of the phase space.

    ↳ hep-exhep-ph0 citations
27. 27*

    Implicit Quantile Networks For Emulation in Jet Physics

    B. Kronheim🇺🇸 · A. Al Kadhim🇺🇸 · M. P. Kuchera🇺🇸 · H. B. Prosper🇺🇸 · R. Ramanujan🇺🇸

    The ability to model and sample from conditional densities is important in many physics applications. Implicit quantile networks (IQN) have been successfully applied to this task in domains outside physics. In this work, we illustrate the potential of IQNs as components of emulators using the simulation of jets as an example. Specifically, we use an IQN to map jets described by their 4-momenta at the generation level to jets at the event reconstruction level. The conditional densities emulated by our model closely match those generated by $\text{Delphes}$, while also enabling faster jet simulation.

    ↳ physics.comp-phhep-phMach.Learn.Sci.Tech.(2024)·0 citations
28. 28*

    On the dark radiation role in the Hubble constant tension

    Stefano Gariazzo🇮🇹 · Olga Mena🇪🇸

    Dark radiation, parameterized in terms of $N_{\mathrm{eff}}$, has been considered many times in the literature as a possible remedy in alleviating the Hubble constant ($H_0$) tension. We review here the effect of such an extra dark radiation component in the different cosmological observables, focusing mostly on $H_0$. While a larger value of $N_{\mathrm{eff}}$ automatically implies a larger value of the Hubble constant, and one would naively expect that such a simple scenario provides a decent solution, more elaborated models are required. Light sterile neutrinos or neutrino asymmetries are among the first-order corrections to the most economical (tree-level) massless dark radiation scenario. However, they are not fully satisfactory in solving the $H_0$ issue. We devote here special attention to second-order corrections: some interacting scenarios, such as those with new dark radiation degrees of freedom that exhibit a non-free streaming nature are highly satisfactory alternative cosmologies where to solve the Hubble constant tension. Models with self-interacting sterile neutrinos and/or majorons, both well-motivated beyond the Standard Model particles, will be discussed along our assessment.

    ↳ astro-ph.COhep-ph11 citations
29. 29*

    Fixed point behavior mapping of cumulants between the three-dimensional Ising model and QCD

    Xue Pan🇨🇳

    Fixed point behavior was found in the temperature dependence of normalized cumulants of order parameter at different external magnetic fields in the three-dimensional Ising model in my last work. In this paper, considering possible existing QCD critical point belonging to the three-dimensional Ising universality class and the non-universal mapping parameters between the Ising model and QCD, effects of the mapping parameters on the fixed point behavior in the net-baryon chemical potential dependence of normalized cumulants along different experimental freeze-out curves is studied in this paper. We found that when the directions of Ising variables, the reduced temperature and external magnetic field, are orthogonal or not far from orthogonal after mapping to the QCD temperature and net-baryon chemical potential plane, the fixed point behavior exists in the net-baryon chemical potential dependence of the normalized cumulants and is closer to the QCD critical point than the peak in the cumulants.

    ↳ nucl-thhep-exhep-ph0 citations
30. 30*

    Atmospheric Lepton Fluxes via Two-Dimensional Matrix Cascade Equations

    Tetiana Kozynets🇩🇰 · Anatoli Fedynitch🇹🇼 · D. Jason Koskinen🇩🇰

    The atmospheric lepton fluxes play a crucial role in many particle and astroparticle physics experiments, e.g. in establishing the neutrino signal and the muon background for neutrino oscillation measurements, or the atmospheric background for astrophysical neutrino searches. The Matrix Cascade Equations (MCEq) code is a numerical tool used to model the atmospheric lepton fluxes by solving a system of coupled differential equations for particle production, interaction, and decay at extremely low computational costs. Previously, the MCEq framework only accommodated longitudinal development of air showers, an approximation that works well for neutrino and muon fluxes at high energies (O(10 GeV) and above). However, for accurate calculations of atmospheric lepton angular distributions at lower energies, the lateral component of hadronic cascades becomes significant, necessitating three-dimensional calculation schemes. We introduce "2D MCEq", an efficient numerical approach for combined longitudinal and angular evolution of air showers that retains the low computational complexity. The accuracy of the "2D MCEq" is affirmed by its benchmark comparison with the standard Monte Carlo code CORSIKA. This study paves the way for efficient three-dimensional calculations of atmospheric neutrino fluxes.

    ↳ astro-ph.HEhep-phPRD(2023)·8 citations
31. 31*

    Prediction of non-SUSY AdS conjecture on the lightest neutrino mass revisited

    Cao H. Nam🇻🇳

    We study the constraint of the non-SUSY AdS conjecture on the three-dimensional vacua obtained from the compactification of the Standard Model coupled to Einstein gravity on a circle where the three-dimensional components of the four-dimensional metric are general functions of both non-compact and compact coordinates. From studying the wavefunction profile of the three-dimensional metric in the compactified dimension, we find that the radius of the compactified dimension must be quantized. Consequently, the three-dimensional vacua are constrained by not only the non-SUSY AdS conjecture but also the quantization rule of the circle radius, leading to both upper and lower bounds for the mass of the lightest neutrino as $\sqrt{2}\le m_{\nu }/\sqrt{{\Lambda }_4}<\sqrt{3}$ where ${\Lambda }_4\simeq 5.06\times 10^{-84}$ GeV${}^2$ is the observed cosmological constant. This means that the lightest neutrino should have a mass around $10^{-32}$ eV or it would be approximately massless. With this prediction, we reconstruct the light neutrino mass matrix that is fixed by the neutrino oscillation data and in terms of three new mixing angles and six new phases for both the normal ordering and inverted ordering. In the situation that the light neutrino mass matrix is Hermitian, we calculate its numerical value in the $3\sigma$ range.

    ↳ hep-thgr-qchep-phPRD(2024)·2 citations
32. 32*

    Scattering amplitudes and electromagnetic horizons

    Anton Ilderton🇬🇧 · William Lindved🇬🇧

    We consider the scattering of charged particles on particular electromagnetic fields which have properties analogous to gravitational horizons. Classically, particles become causally excluded from regions of spacetime beyond a null surface which we identify as the `electromagnetic horizon'. In the quantum theory there is pair production at the horizon via the Schwinger effect, but only one particle from the pair escapes the field. Furthermore, unitarity appears to be violated when crossing the horizon, and there is no well-defined S-matrix. Despite this, we show how to use the perturbiner method to construct `amplitudes' which contain all the dynamical information required to construct observables related to pair creation, and to radiation from particles scattering on the background.

    ↳ hep-thgr-qchep-phJHEP(2023)·16 citations
33. 33*

    Accurate determination of ${}^{6,7}$Li nuclear magnetic moments

    Krzysztof Pachucki🇵🇱 · Vojtěch Patkóš🇨🇿 · Vladimir A. Yerokhin🇩🇪

    We report an accurate determination of the nuclear magnetic dipole moments of ${}^{6,7}$Li from the measured ratio of the nuclear and the electron $g$-factors in atomic Li. The obtained results significantly improve upon the literature values and stress the importance of reliable theoretical calculations of the nuclear shielding corrections.

    ↳ physics.atom-phhep-phnucl-thPLB(2023)·4 citations
34. 34*

    Prospects of $CP$ violation in $\Lambda$ decay with polarized electron beam at STCF

    Sheng Zeng🇨🇳 · Yue Xu🇨🇳 · Xiao Rong Zhou🇨🇳 · Jia Jia Qin🇨🇳 · Bo Zheng🇨🇳

    Based on $1.89\times 10^8$ $J/\psi \to \Lambda \bar{\Lambda }$ Monte Carlo (MC) events produced from a longitudinally-polarized electron beam, the sensitivity of $CP$ violation of $\Lambda$ decay is studied with fast simulation software. In addition, the $J/\psi \to \Lambda \bar{\Lambda }$ decay can also be used as a process to optimize the detector response using the interface provided by the fast simulation software. In the future, STCF is expected to obtain 3.4 trillion $J/\psi$ events, and the statistical sensitivity of $CP$ violation of $\Lambda$ decay via $J/\psi \to \Lambda \bar{\Lambda }$ process is expected to reach $\mathcal{O}$~$(10^{-5})$ when the electron beam polarization is 80\%.

    ↳ hep-exhep-phCPC(2023)·12 citations
35. 35*

    Electromagnetic Cascade Emission from Neutrino-Coincident Tidal Disruption Events

    Chengchao Yuan🇩🇪 · Walter Winter🇩🇪

    The potential association between Tidal Disruption Events (TDEs) and high-energy astrophysical neutrinos implies the acceleration of cosmic rays. These accelerated particles will initiate electromagnetic (EM) cascades spanning from keV to GeV energies by the processes related to neutrino production. We model the EM cascade and neutrino emissions by numerically solving the time-dependent transport equations and discuss the implications for AT2019dsg and AT2019fdr in the X-ray and $\gamma$-ray bands. We show that the $\gamma$-ray constraints from \emph{Fermi} can constrain the size of the radiation zone and the maximum energy of injected protons, and that the corresponding expected neutrino event numbers in follow-up searches are limited to be less than about 0.1. Depending on the efficiency of $p\gamma$ interactions, the X-ray and $\gamma$-ray signals can be expected closer to the peak of the optical-ultraviolet (OUV) luminosity, or to the time of the neutrino production.

    ↳ astro-ph.HEhep-phApJ(2023)·17 citations
36. 36*

    Revisiting Recent Progress in the Karch-Randall Braneworld

    Hao Geng🇺🇸

    Motivated by the study of entanglement island in the Karch-Randall braneworld, it has been conjectured and proven in general that entanglement island is not consistent with long-range (massless) gravity. In this paper, we provide a careful check of this conclusion in a model of massless gravity that is constructed using the Karch-Randall braneworld. We show that there is indeed no entanglement island and hence not a nontrivial Page curve due to the diffeomorphism invariance if we are studying the correct question which is though subtle. Moreover, we show that this conclusion is not affected by deforming the setup with the Dvali--Gabadadze--Porrati (DGP) terms. Furthermore, we show that the consistency of holography in this model will provide nontrivial constraints to the DGP parameters. This study provides an example that causality and holography in anti-de Sitter space can be used to constrain low energy effective theories. At the end, we clarify several subtleties in the braneworld gravity which are overlooked in the literature and we discuss the robustness of the above results against possible coarse-graining protocols to define a subregion in a gravitational theory.

    ↳ hep-thgr-qchep-phClass.Quant.Grav.(2026)·44 citations
37. 37*

    Constraining braneworlds with entanglement entropy

    Hao Geng🇺🇸 · Andreas Karch🇺🇸 · Carlos Perez-Pardavila🇺🇸 · Lisa Randall🇺🇸 · Marcos Riojas🇺🇸 · Sanjit Shashi🇺🇸 · Merna Youssef🇺🇸

    We propose swampland criteria for braneworlds viewed as effective field theories of defects coupled to semiclassical gravity. We do this by exploiting their holographic interpretation. We focus on general features of entanglement entropies and their holographic calculations. Entropies have to be positive. Furthermore, causality imposes certain constraints on the surfaces that are used holographically to compute them, most notably a property known as causal wedge inclusion. As a test case, we explicitly constrain the Dvali--Gabadadze--Porrati term as a second-order-in-derivatives correction to the Randall--Sundrum action. We conclude by discussing the implications of these criteria for the question on whether entanglement islands in theories with massless gravitons are possible in Karch--Randall braneworlds.

    ↳ hep-thgr-qchep-phSciPost Phys.(2023)·33 citations
38. 38*

    On Asymptotic Dark Energy in String Theory

    Sera Cremonini🇺🇸 · Eduardo Gonzalo🇺🇸 · Muthusamy Rajaguru🇺🇸 · Yuezhang Tang🇺🇸 · Timm Wrase🇺🇸

    We examine bounds on accelerated expansion in asymptotic regions of the moduli space in string theory compactifications to four spacetime dimensions. While there are conjectures that forbid or constrain accelerated expansion in such asymptotic regions, potential counter examples have been discussed recently in the literature. We check whether such counter examples can arise in explicit string theory constructions, focusing in particular on non-geometric compactifications of type IIB string theory that have no Kähler moduli. We find no violation of the Strong Asymptotic dS Conjecture and thus provide support for the absence of accelerated expansion in asymptotic regions of a barely explored corner of the string landscape. Moreover, working in a simplified setting, we point out a new mechanism for potentially connecting the Sharpened Distance Conjecture and the Strong Asymptotic dS Conjecture. If this argument could be generalized, it would mean that the Sharpened Distance Conjecture is implied by the Strong Asymptotic dS Conjecture, and that their exponential factors are naturally related by a factor of 2.

    ↳ hep-thhep-phJHEP(2023)·31 citations
39. 39*

    Unveiling Neutrino Halos with CMB Lensing

    Selim C. Hotinli🇺🇸 · Nashwan Sabti🇺🇸 · Jaxon North🇺🇸 · Marc Kamionkowski🇺🇸

    The existence of a cosmic neutrino background has been inferred indirectly from cosmological surveys through its effect on the linear-theory evolution of primordial density perturbations, as well as from measurements of the primordial abundances of light elements. Constraints on the masses of the three neutrino species imply that at least two of them move non-relativistically today. As a consequence, non-linear evolution of density perturbations results in the formation of neutrino halos around dark-matter halos. We study whether these neutrino halos can be detected in the foreseeable future through measurements of weak gravitational lensing of the cosmic microwave background, thus providing, possibly, the first beyond-linear-theory signature of cosmic neutrinos.

    ↳ astro-ph.COhep-phPRD(2023)·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.