Fri·Jun 2, 2023Friday·June 2, 2023

1. 01*

   Complete Formalism of Cross Sections and Asymmetries for Longitudinally and Transversely Polarized Leptons and Hadrons in Deep Inelastic Scattering

   Paul Anderson🇺🇸 · Douglas Higinbotham🇺🇸 · Sonny Mantry🇺🇸 · Xiaochao Zheng🇺🇸

   Studies of the Deep Inelastic Scattering (DIS) have provided fundamental information of the nucleon structure for decades. The electron-ion collider (EIC) will be the first collider capable of DIS study with both polarized lepton and polarized hadron beams, providing the possibility of accessing new electroweak structure functions of the nucleon. In this work, we completed the DIS cross section derivations for both longitudinally and transversely polarized leptons and hadrons, with no approximations made, and with all three contributions $\gamma \gamma ,\gamma Z,ZZ$ included. These results were derived using primarily tensor algebra and Feynman calculus, starting from previously established leptonic and hadronic tensors and carry out their contraction. Our results are presented in terms of both spin-averaged and spin-dependent cross sections, allowing direct comparison with experimentally measured cross sections and their asymmetries. We include also in our discussion comparisons of different conventions that exist in the literature.

   hep-phhep-exnucl-exnucl-th2 citations
2. 02*

   A road to an elementary particle physics model with no Higgs -- I

   Giancarlo Rossi🇮🇹

   This is the first of two companion papers where we prove that the recently discovered non perturbative mechanism capable of giving mass to elementary fermions, in the presence of weak interactions can also generate a mass for the $W$, and can thus be used as a viable alternative to the Higgs scenario. The non perturbative fermion and $W$ masses have the form $m_f\sim C_f(\alpha ){\Lambda }_{RGI}$ and $M_W\sim g_w{c}_w(\alpha ){\Lambda }_{RGI}$ with $C_f(\alpha )$ and $c_w(\alpha )$ functions of the gauge couplings, $g_w$ the weak coupling and ${\Lambda }_{RGI}$ the RGI scale of the theory. These parametric structures imply that a realistic model must include a new sector of massive fermions (Tera-fermions) subjected, besides Standard Model interactions, to some kind of super-strong gauge interactions (Tera-interactions) so that the RGI scale of the full theory, ${\Lambda }_T$, will be in the few TeV region. The extension of the model by introducing hypercharge and particles singlets under strong interactions (leptons and Tera-leptons) is the focus of the companion paper, where we also discuss some phenomenological implications of this approach. One can show that, upon integrating out the (heavy) Tera-degrees of freedom, the resulting low energy effective Lagrangian closely resembles the Standard Model Lagrangian. The argument rests on the conjecture that the 125 GeV resonance detected at LHC is a $W^{+}{W}^{-}/ZZ$ composite state, bound by Tera-particle exchanges, and not an elementary object. Although we restrict to the one family case, neglecting weak isospin splitting, this scheme has a certain number of merits with respect to the Standard Model. It offers a radical solution of the Higgs mass tuning problem as there is no Higgs. It allows identifying ${\Lambda }_T$ as the electroweak scale. It helps reducing the number of Standard Model parameters as elementary particle masses are determined by the dynamics.

   hep-phhep-th4 citations
3. 03*

   A road to an elementary particle physics model with no Higgs -- II

   Giancarlo Rossi🇮🇹

   This is the second of two companion papers in which we continue developing the construction of an elementary particle model with no Higgs. Here we show that the recently identified non-perturbative field-theoretical feature, alternative to the Higgs mechanism and capable of giving masses to quarks, Tera-quarks and $W$, can also provide mass to leptons and Tera-leptons when the model is extended to include, besides strong, Tera-strong and weak interactions, also hypercharge. In the present approach elementary fermion masses are not free parameters but are determined by the dynamics of the theory. We derive parametric formulae for elementary particle masses from which we can ``predict'' the order of magnitude of the scale of the new Tera-interaction and get crude numerical estimates for mass ratios in fair agreement with phenomenology. The interest of considering elementary particle models endowed with this kind of non-perturbative mass generation mechanism is that they allow solving some of the conceptual problems of the present formulation of the Standard Model, namely origin of the electroweak scale and naturalness.

   hep-phhep-th4 citations
4. 04*

   Gravitational Wave Signatures of Gauged Baryon and Lepton Number

   Jessica Bosch🇺🇸 · Zoraida Delgado🇺🇸 · Bartosz Fornal🇺🇸 · Alejandra Leon🇺🇸

   We demonstrate that novel types of gravitational wave signatures arise in theories with new gauge symmetries broken at high energy scales. For concreteness, we focus on models with gauged baryon number and lepton number, in which neutrino masses are generated via the type I seesaw mechanism, leptogenesis occurs through the decay of a heavy right-handed neutrino, and one of the new baryonic fields is a good dark matter candidate. Depending on the scalar content of the theory, the gravitational wave spectrum consists of contributions from cosmic strings, domain walls, and first order phase transitions. We show that a characteristic double-peaked signal from domain walls or a sharp domain wall peak over a flat cosmic string background may be generated. Those new signatures are within the reach of future experiments, such as Cosmic Explorer, Einstein Telescope, DECIGO, Big Bang Observer, and LISA.

   hep-phgr-qcPRD(2023)·10 citations
5. 05*

   Dynamical Inflation Stimulated Cogenesis

   Debasish Borah🇮🇳 · Arnab Dasgupta🇺🇸 · Daniel Stolarski🇨🇦

   We propose a minimal setup that realises dynamical inflection point inflation, and, using the same field content, generates neutrino masses, a baryon asymmetry of the universe, and dark matter. A dark $SU(2{)}_D$ gauge sector with a dark scalar doublet playing the role of inflaton is considered along with several doublet and singlet fermions sufficient to realise multiple inflection points in the inflaton potential. The singlet fermions couple to SM leptons and generate neutrino masses via the inverse seesaw mechanism. Those fermions also decay asymmetrically and out of equilibrium, generating a baryon asymmetry via leptogenesis. Some of the fermion doublets are dark matter, and they are produced via inflaton decay and freeze-in annihilation of the same fermions that generate the lepton asymmetry. Reheating, leptogenesis, and dark matter are all at the TeV scale.

   hep-phastro-ph.COJHEP(2024)·1 citation
6. 06*

   Melting of Quarkonia in strong magnetic field

   Manohar Lal🇮🇳 · Siddhartha Solanki🇮🇳 · Rishabh Sharma🇮🇳 · Vineet Kumar Agotiya🇮🇳

   In this paper, spectra of the quarkonium states has been studied using the conditions temperature, chemical potential and the magnetic field. Here our main focus is to study the effect of strong magnetic field on the quarkonium properties. The binding energies and the dissociation temperature for the ground and the first excited states of the charmonium and bottomonium in the presence of strong magnetic field at chemical potential \mu = 500 MeV has been studied. Here we use quasiparticle (QP) Debye mass depending upon temperature, magnetic field and chemical potential obtained from the quasiparticle approach. The Debye mass strongly increases at different values of temperature and magnetic field. The binding energy decreases with increase in the temperature at different magnetic field eB= 0.3, 0.5, and 0.7 GeV2 and also decreases with magnetic field at different at T=200,300 and 400 MeV for the J/\psi, \psi, \upsilon, and \upsilon prime states of the quarkonia. The dissociation temperature of the quarkonium states falls with the increasing values of the magnetic field at critical temperature Tc =197 MeV

   hep-phhep-thIndian J.Pure Appl.Phys.(2022)·1 citation
7. 07*

   Chiral Transport Phenomena and Compact Stars

   Cristina Manuel🇪🇸

   I will review the main chiral transport phemomena arising in systems made up of (almost) massless fermions associated to the quantum chiral anomaly. These quantum effects might have relevant implications in compact stars, and I will review some relevant works that reveal so. I will also show how a conservation law that has the same form of the chiral anomaly also emerge in perfect classical fluids, which expresses a conservation law of magnetic, fluid and mixed helicities for isentropic fluids, and why this should also be relevant in compact stars.

   hep-phnucl-thJ.Phys.Conf.Ser.(2023)·0 citations
8. 08*

   Super Restoration of Chiral Symmetry in Massive Four-Fermion Interaction Models

   Tomohiro Inagaki🇯🇵 · Daiji Kimura🇯🇵 · Hiromu Shimoji🇯🇵

   The chiral symmetry is explicitly and spontaneously broken in a strongly interacting massive fermionic system. We study the chiral symmetry restoration in massive four-fermion interaction models with increasing temperature and chemical potential. At high temperature and large chemical potential, we find the boundaries where the spontaneously broken chiral symmetry can be fully restored in the massive Gross--Neveu model. We call the phenomenon super restoration. The phase boundary is obtained analytically and numerically. In the massive Nambu--Jona-Lasinio model, it was found that whether super restoration occurs depends on regularizations. We also evaluate the behavior of the dynamical mass and show the super restoration boundaries on the ordinary phase diagrams.

   hep-phPRD(2024)·1 citation
9. 09*

   Exploring the dark sectors via the cooling of white dwarfs

   Jaime Hoefken Zink🇮🇹 · Maura E. Ramirez-Quezada🇯🇵

   As dense and hot bodies with a well-understood equation of state, white dwarfs offer a unique opportunity to investigate new physics. In this paper, we examine the role of dark sectors, which are extensions of the Standard Model of particle physics that are not directly observable, in the cooling process of white dwarfs. Specifically, we examine the role of a dark photon, within the framework of a three-portal Model, in enhancing the neutrino emission during the cooling process of white dwarfs. We compare this scenario to the energy release predicted by the Standard Model. By analyzing the parameter space of dark sectors, our study aims to identify regions that could lead to significant deviations from the expected energy release of white dwarfs.

   hep-phPRD(2023)·4 citations
10. 10*

    Elastic pion-proton and pion-pion scattering via the holographic Pomeron and Reggeon exchange

    Zhibo Liu🇨🇳 · Akira Watanabe🇨🇳

    The elastic pion-proton and pion-pion scattering are studied in a holographic QCD model, focusing on the Regge regime. Taking into account the Pomeron and Reggeon exchange, which are described by the Reggeized $2^{++}$ glueball and vector meson propagator respectively, the total and differential cross sections are calculated. The adjustable parameters involved in the model are determined with the experimental data of the pion-proton total cross sections. The differential cross sections can be predicted without any additional parameters, and it is shown that our predictions are consistent with the data. The energy dependence of the Pomeron and Reggeon contribution is also discussed.

    hep-phhep-exnucl-exnucl-thPRD(2023)·6 citations
11. 11*

    Associated Production of Neutrino and Dark Fermion at Future Lepton Colliders

    Shao-Feng Ge🇨🇳 · Kai Ma🇨🇳 · Xiao-Dong Ma🇨🇳 · Jie Sheng🇨🇳

    Fermionic dark matter can be pairly produced and hence searched with missing energy at colliders. We extend such probe to the associated production of a neutrino and a dark sector fermion at the future $e^{+}{e}^{-}$ colliders such as CEPC, FCC-ee, ILC, and CLIC. Two typical processes, the mono-photon and electron-positron pair productions associated with missing energy, can serve the purpose. While the mono-photon search prevails at CEPC, FCC-ee, and ILC, the $e^{+}{e}^{-}\text{met}$ channel has more significant contributions at CLIC with much higher collision energy $\sqrt{s}$. The beam polarizations can help further suppressing the SM backgrounds to enhance the signal significance while differential cross sections can distinguish the Lorentz structure of various effective operators. The combined sensitivity can reach well above $1\text{tev}$ at CEPC/FCC-ee and ILC while it further touches 30\,TeV at CLIC. Comparing with the updated results from the direct detection experiments (XENON1T, PandaX-II, PandaX-4T, LZ, and XENONnT), astrophysical $X/\gamma$-ray observations, and cosmological constraints for the sub-MeV absorption dark matter, the collider searches are actually more sensitive and hence can provide a complementary approach to addressing the dark fermions.

    hep-phJHEP(2023)·19 citations
12. 12*

    The effect of gluon condensate on the entanglement entropy in a holographic model

    Xun Chen🇨🇳 · Bo Yu🇨🇳 · Peng-Cheng Chu🇨🇳 · Xiao-Hua Li🇨🇳 · Mitsutoshi Fujita🇨🇳

    In this study, we examine the impact of the gluon condensate on holographic entanglement entropy within an Einstein-Dilaton model at both zero and finite temperatures. A critical length exists for the difference in entanglement entropy between connected and disconnected surfaces in this model, which is typically interpreted as an indicator of phase transition. As the gluon condensate increases, the critical length decreases, suggesting that confinement strengthens at zero temperature. Additionally, the entropic C-function abruptly drops to zero at the critical length, indicating the absence of entangled states. At finite temperatures, the results show that the effect of the gluon condensate on the critical length is qualitatively similar to that at zero temperature. We observe that the entropic C-function increases as a function of $L$ at finite temperature, though it exhibits competitive behaviors when the gluon condensate is large.

    hep-phPTEP(2025)·2 citations
13. 13*

    Exclusive ${\eta }_c$ production by ${\gamma }^{\ast }\gamma$ interactions in electron-ion collisions

    Izabela Babiarz🇵🇱 · Victor P. Goncalves🇧🇷 · Wolfgang Schäfer🇵🇱 · Antoni Szczurek🇵🇱

    One of the main goals of future electron-ion colliders is to improve our understanding of the structure of hadrons. In this letter, we study the exclusive ${\eta }_c$ production by ${\gamma }^{\ast }\gamma$ interactions in $eA$ collisions and demonstrate that future experimental analysis of this process can be used to improve the description of the ${\eta }_c$ transition form factor. The rapidity, transverse momentum and photon virtuality distributions are estimated considering the energy and target configurations expected to be present at the EIC, EicC and LHeC and assuming different predictions for the light-front wave function of the ${\eta }_c$ meson. Our results indicate that the electron-ion colliders can be considered an alternative to providing supplementary data to those obtained in $e^{-}{e}^{+}$ colliders.

    hep-phnucl-thPLB(2023)·10 citations
14. 14*

    Anisotropic behavior of S-wave and P-wave states of heavy quarkonia at finite magnetic field

    Manohar Lal🇮🇳 · Siddhartha Solanki🇮🇳 · Rishabh Sharma🇮🇳 · Vineet Kumar Agotiya🇮🇳

    We studied the effect of momentum space anisotropy on heavy quarkonium states using an extended magnetized effective fugacity quasiparticle model (EQPM). Both the real and imaginary part of the potential has been modified through the dielectric function by including the anisotropic parameter $\xi$. The real part of the medium modified potential becomes more attractive in the presence of the anisotropy and constant magnetic field. The binding energy of the 1S, 2S, and 1P quarkonium states including anisotropy effects for both the oblate and the isotropic case were studied. We find that the binding energy of quarkonium states becomes stronger in the presence of anisotropy. However, the magnetic field is found to reduce the binding energy. The thermal width of the charmonium and bottomonium 1S states have been studied at constant magnetic field eB = 0.3 GeV2 for isotropic and prolate cases. The effect of magnetic field on the mass spectra of the 1P state for the oblate case was also examined. The dissociation temperature for the 1S, 2S, and 1P charmonium and bottomonium have been determined to be higher for the oblate case with respect to the isotropic case

    hep-phAdv.High Energy Phys.(2023)·5 citations
15. 15*

    Introduction to Generalized Global Symmetries in QFT and Particle Physics

    T. Daniel Brennan🇺🇸 · Sungwoo Hong🇰🇷

    Generalized symmetries (also known as categorical symmetries) is a newly developing technique for studying quantum field theories. It has given us new insights into the structure of QFT and many new powerful tools that can be applied to the study of particle phenomenology. In these notes we give an exposition to the topic of generalized/categorical symmetries for high energy phenomenologists although the topics covered may be useful to the broader physics community. Here we describe generalized symmetries without the use of category theory and pay particular attention to the introduction of discrete symmetries and their gauging.

    hep-phhep-th263 citations
16. 16*

    Looking forward to photon-coupled long-lived particles IV: neutralino-ALPino/gravitino

    Krzysztof Jodłowski🇰🇷

    Various supersymmetric (SUSY) scenarios predict a sub-GeV neutralino decaying into a single photon and an invisible state. This signature has recently been studied in a number of intensity frontier experiments, finding constraints complementary to the usual collider searches. In this work, we study the prospects of searches for long-lived neutralinos coupled to an ALPino or gravitino, where each can act as the lightest SUSY particle (LSP). In addition to the neutralino decays into a LSP and a photon, we also consider three-body decays into a pair of charged leptons, and signatures related to scattering with electrons and secondary neutralino production. For both models, we find that the searches at FASER2 will allow to overcome the current bounds, while SHIP will extend these limits by more than an order of magnitude in the value of the coupling constant.

    hep-ph2 citations
17. 17*

    The Higgs Mechanism and Higgs Boson: Unveiling the Symmetry of the Universe

    Ahmed Abokhalil🇪🇬

    The discovery of the Higgs boson at the Large Hadron Collider marked a significant milestone in particle physics. The Higgs mechanism, a key theoretical framework, provides profound insights into the origin of particle masses and the spontaneous breaking of symmetries. In this review article, we delve into the fundamental aspects of the Higgs mechanism and Higgs boson physics while exploring related topics such as Noether's theorem, gauge invariance, and the $U(1)$ and $SU(2)$ models. Additionally, we examine Goldstone's theorem, the extension of the Higgs mechanism to $U(1)$ and $SU(2)$ models, and its role in the electroweak theory for understanding the masses of the $W$ and $Z$ bosons. Finally, we scrutinize the properties of the Higgs boson itself, its production mechanisms, and decay processes, shedding light on its significance in unraveling the mysteries of the universe.

    hep-ph13 citations
18. 18*

    Proton charge radius extraction from muon scattering at MUSE using dispersively improved chiral effective field theory

    F. Gil-Domínguez🇪🇸 · J. M. Alarcón🇪🇸 · C. Weiss🇺🇸

    The MUSE experiment at Paul Scherrer Institute will perform the first measurement of low-energy muon-proton elastic scattering (muon lab momenta 115-210 MeV) with the aim of determining the proton charge radius. We study the prospects for the proton radius extraction using the theoretical framework of Dispersively Improved Chiral Effective Field Theory (DI$\chi$EFT). It connects the proton radii with the finite-$Q^2$ behavior of the form factors through complex analyticity and enables the use of data up to $Q^2\sim$ 0.1 GeV${}^2$ for radius extraction. We quantify the sensitivity of the $\mu p$ cross section to the proton charge radius, the theoretical uncertainty of the cross section predictions, and the size of two-photon exchange corrections. We find that the optimal kinematics for radius extraction at MUSE is at momenta 210 MeV and $Q^2\sim$ 0.05-0.08 GeV${}^2$. We compare the performance of electron and muon scattering in the same kinematics. As a byproduct, we obtain explicit predictions for the $\mu p$ and $ep$ cross sections at MUSE as functions of the assumed value of the proton radius.

    hep-phhep-exnucl-exnucl-thPRD(2023)·6 citations
19. 19*

    Bounds on lepton non-unitarity and heavy neutrino mixing

    Mattias Blennow🇸🇪 · Enrique Fernández-Martínez🇪🇸 · Josu Hernández-García🇭🇺 · Jacobo López-Pavón🇪🇸 · Xabier Marcano🇪🇸 · Daniel Naredo-Tuero🇪🇸

    We present an updated and improved global fit analysis of current flavor and electroweak precision observables to derive bounds on unitarity deviations of the leptonic mixing matrix and on the mixing of heavy neutrinos with the active flavours. This new analysis is motivated by new and updated experimental results on key observables such as $V_{ud}$, the invisible decay width of the $Z$ boson and the $W$ boson mass. It also improves upon previous studies by considering the full correlations among the different observables and explicitly calibrating the test statistic, which may present significant deviations from a ${\chi }^2$ distribution. The results are provided for three different Type-I seesaw scenarios: the minimal scenario with only two additional right-handed neutrinos, the next to minimal one with three extra neutrinos, and the most general one with an arbitrary number of heavy neutrinos that we parametrize via a generic deviation from a unitary leptonic mixing matrix. Additionally, we also analyze the case of generic deviations from unitarity of the leptonic mixing matrix, not necessarily induced by the presence of additional neutrinos. This last case relaxes some correlations among the parameters and is able to provide a better fit to the data. Nevertheless, inducing only leptonic unitarity deviations avoiding both the correlations implied by the right-handed neutrino extension as well as more strongly constrained operators is challenging and would imply significantly more complex UV completions.

    hep-phhep-exJHEP(2023)·116 citations
20. 20*

    Getting the most on supernova axions

    Alessandro Lella🇮🇹 · Pierluca Carenza🇸🇪 · Giampaolo Co'🇮🇹 · Giuseppe Lucente🇮🇹 · Maurizio Giannotti🇺🇸 · Alessandro Mirizzi🇮🇹 · Thomas Rauscher🇨🇭

    Axion-like particles (ALPs) coupled to nucleons might be copiously emitted from a supernova (SN) core. We extend existing bounds on free-streaming ALPs to the case in which these are so strongly-interacting with the nuclear matter to be trapped in the SN core. For strongly-interacting ALPs, we also extend the bound from the absence of an ALP-induced signal in Kamiokande-II neutrino detector at the time of SN 1987A. We find that combining the different arguments, SNe exclude values of ALP-nucleon coupling $g_{aN}\gtrsim 10^{-9}$ for ALP masses $m_a\lesssim 1\mathrm{MeV}$. Remarkably, in the case of canonical QCD axion models, the SN bounds exclude all values of $m_a\gtrsim 10^{-2}\mathrm{eV}$. This result prevents the possibility for current and future cosmological surveys to detect any signatures due to hot dark matter QCD axion mass.

    hep-phastro-ph.HEPRD(2024)·120 citations
21. 21*

    Holographic neutrino transport in dense strongly-coupled matter

    M. Järvinen🇰🇷 · E. Kiritsis🇫🇷 · F. Nitti🇫🇷 · E. Préau🇫🇷

    A (toy) model for cold and luke-warm strongly-coupled nuclear matter at finite baryon density is used to study neutrino transport. The complete charged current two-point correlators are computed in the strongly-coupled medium and their impact on neutrino transport is analyzed. The full result is compared with various approximations for the current correlators and the distributions, including the degenerate approximation, the hydrodynamic approximation as well as the diffusive approximation and we comment on their successes. Further improvements are discussed.

    ↳ astro-ph.HEhep-phhep-thnucl-thJHEP(2023)·10 citations
22. 22*

    Low-lying odd-parity nucleon resonances as quark-model like states

    Curtis D. Abell🇦🇺 · Derek B. Leinweber🇦🇺 · Zhan-Wei Liu🇨🇳 · Anthony W. Thomas🇦🇺 · Jia-Jun Wu🇨🇳

    Recent lattice QCD results for the low-lying odd-parity excitations of the nucleon near the $N^{\ast }(1535)$ and $N^{\ast }(1650)$ resonance positions have revealed that the lattice QCD states have magnetic moments consistent with predictions from a constituent-quark-model. Using Hamiltonian Effective Field Theory (HEFT) to describe pion-nucleon scattering in the $I(J^P)=\frac{1}{2}({\frac{1}{2}}^{-})$ channel, we represent these two quark-model like states as two single-particle bare basis states, dressed and mixed by meson-baryon scattering channels. By constraining the free parameters of the Hamiltonian with $S_{11}$ pion-nucleon scattering data, we perform the first calculation of the finite-volume spectrum using two bare-baryon basis states. By comparing this spectrum to contemporary lattice QCD results at three lattice volumes, we analyse the eigenvectors of the Hamiltonian to gain insight into the structure and composition of these two low-lying resonances. We find that an interpretation of the two low-lying nucleon resonances as quark-model like states dressed by meson-baryon interactions is consistent with both the $S_{11}$ scattering data and lattice QCD. We introduce a novel HEFT formalism for estimating scattering-state contaminations in lattice QCD correlation functions constructed with standard three-quark operators. Not only are historical lattice QCD results described with excellent accuracy, but correlation functions with large scattering-state contaminations are identified.

    ↳ hep-lathep-phnucl-thPRD(2023)·35 citations
23. 23*

    Impact of big bang nucleosynthesis on the H0 tension

    Tomo Takahashi🇯🇵 · Yo Toda🇯🇵

    We investigate the impact of big bang nucleosynthesis (BBN) on the Hubble tension, focusing on how the treatment of the reaction rate and observational data affect the evaluation of the tension. We show that the significance of the tension can vary by $0.8\sigma$ in some early dark energy model, depending on the treatment of the reaction rate and observational data. This indicates that how we include the BBN data in the analysis can give a significant impact on the Hubble tension, and we need to carefully consider the assumptions of the analysis to evaluate the significance of the tension when the BBN data is used.

    ↳ astro-ph.COgr-qchep-phJCAP(2023)·9 citations
24. 24*

    Mass spectrum in a six-dimensional $SU(n)$ gauge theory on a magnetized torus

    Kentaro Kojima🇯🇵 · Yuri Okubo🇯🇵 · Carolina Sayuri Takeda🇯🇵

    We examine six-dimensional $SU(n)$ gauge theories compactified on a two-dimensional torus with a constant magnetic flux background to obtain a comprehensive low-energy mass spectrum. We introduce general background configurations including the magnetic flux and continuous Wilson line phases, consistent with classical equations of motion. Under the standard gauge fixing procedure, the complete mass spectrum in low-energy effective theory for the $SU(n)$ case is newly presented without imposing restrictions on the gauge fixing parameter. Our analysis confirms the inevitable existence of tachyonic modes, which neither depend on the background configurations of Wilson line phases nor are affected by the gauge fixing parameter. Masses for some low-energy modes exhibit dependence on the gauge fixing parameter, and these modes are identified as would-be Goldstone bosons that are absorbed by massive four-dimensional vector fields. We discuss the phenomenological implications associated with stabilization or condensation of the tachyonic states. Various mass spectra and symmetry-breaking patterns are expected with flux backgrounds in the $SU(n)$ case. They are helpful for constructing phenomenologically viable models beyond the standard model, such as gauge-Higgs unification and grand unified theories.

    ↳ hep-thhep-phJHEP(2023)·6 citations
25. 25*

    Neutrino mass and nature through its mediation in atomic clock interference

    José Bernabeu🇪🇸 · Dylan O. Sabulsky🇫🇷 · Federico Sánchez🇨🇭 · Alejandro Segarra🇩🇪

    The absolute mass of neutrinos and their nature are presently unknown. Aggregate matter has a coherent weak charge leading to a repulsive interaction mediated by a neutrino pair. Near its range at micron distances the virtual neutrinos are non-relativistic, giving a distinct behavior for Dirac versus Majorana mass terms. The magnitude and the distance dependence of the effective potential disentangle these fundamental properties of neutrinos. We propose an experiment to search for this potential based on the concept that the density dependent interaction of an atomic probe with a material source in one arm of an atomic clock interferometer generates a differential phase. The appropriate geometry of the device is selected using the saturation of the weak potential as a guide. The proposed experiment has the added benefit of being sensitive to gravity at micron distances. A strategy to suppress the competing Casimir-Polder interaction, depending on the electronic structure of the material source, as well as a way to compensate the gravitational interaction in the two arms of the interferometer is discussed.

    ↳ physics.atom-phhep-phAVS Quantum Sci.(2023)·1 citation
26. 26*

    Constraining Palatini gravity with GR-independent equations of state for neutron stars

    Eva Lope-Oter🇪🇸 · Aneta Wojnar🇪🇸

    We demonstrate how to construct GR-independent equations of state. We emphasize the importance of using theory-based principles instead of relying solely on astrophysical observables and General Relativity (GR). We build a set of equations of state based on first principles, including chiral perturbation theory and perturbation theory in quantum chromodynamics. Interpolation methods are employed to assume thermodynamic stability and causality in the intermediate region. These equations of state are then used to constrain quadratic Palatini $f(\mathcal{R})$ gravity, indicating that the parameter lies within the range $-6.47\lesssim \beta \lesssim 1.99$ km${}^2$. Additionally, we briefly discuss the problem of phase transitions and twin stars.

    ↳ gr-qcastro-ph.HEhep-phnucl-thJCAP(2024)·19 citations
27. 27*

    Novel CMB constraints on the $\alpha$ parameter in alpha-attractor models

    Laura Iacconi🇬🇧 · Matteo Fasiello🇪🇸 · Jussi Väliviita🇫🇮 · David Wands🇬🇧

    Cosmological $\alpha$-attractors are a compelling class of inflationary models. They lead to universal predictions for large-scale observables, broadly independent from the functional form of the inflaton potential. In this work we derive improved analytical predictions for the large-scale observables, whose dependence on the duration of reheating and the parameter $\alpha$ is made explicit. We compare these with Planck and BICEP/Keck 2018 data in the framework of a Bayesian study, employing uniform logarithmic and linear priors for $\alpha$. Our improved universal predictions allow direct constraints on the duration of reheating. Furthermore, while it is well-known that CMB constraints on the tensor-to-scalar ratio can be used to place an upper bound on the $\alpha$ parameter, we demonstrate that including the $\alpha$-dependence of the scalar spectral tilt yields novel constraints on $\alpha$. In particular, for small $\alpha$, the scalar spectral tilt scales with ${\log }_{10}\alpha$, regardless of the specific potential shape. For decreasing $\alpha$, this eventually puts the models in tension with CMB measurements, bounding the magnitude of $\alpha$ from below. Therefore, in addition to the upper bound from the tensor-to-scalar ratio, we derive the first lower bound on the magnitude of $\alpha$ for $\alpha$-attractor T-models, ${\log }_{10}\alpha =-4.2_{-8.6}^{+5.4}$ at $95\%$ C.L. .

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2023)·26 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.