Thu·Sep 8, 2022Thursday·September 8, 2022

1. 01*

   Revealing the inner structure of the newly observed ${\eta }_1(1855)$ via photoproduction

   Yin Huang🇨🇳 · Hong Qiang Zhu🇨🇳

   Very recently, a new hadronic exotic state ${\eta }_1(1855)$ at the invariant mass spectrum of $\eta {\eta }^{{}^{\prime }}$ was observed by the BESIII Collaboration. According to its properties, such as the spectroscopy and decay width, the ${\eta }_1(1855)$ have been suggested to be a compact multi-quark state, a hadron molecule, or a hybrid meson. In order to distinguish the various interpretations of the ${\eta }_1(1855)$, a Reggeized model combined with the vector dominance model for ${\eta }_1(1855)$ photoproduction on the proton target is presented. If the ${\eta }_1(1855)$ is a $s\bar{s}g$ hybrid meson, the ${\eta }_1(1855)$ can be produced though the Primakoff effect. However, the ${\eta }_1(1855)$ photoproduction is dominated by the $t$-channel vector mesons $\rho$, $\omega$, and $\varphi$ exchange by assuming ${\eta }_1(1855)$ as an $S$-wave $K{\bar{K}}_1(1400)$ molecular state. Our calculations show that the total cross section of the ${\eta }_1(1855)$ production via $\gamma p$ reaction can reach up to 0.115 pb, about 0.0124$\%$ of the total cross section obtained by considering the ${\eta }_1(1855)$ as an $S$-wave $K{\bar{K}}_1(1400)$ molecule. We also find their line shapes are sizably different. If the ${\eta }_1(1855)$ is a molecular state, the photoproduction of ${\eta }_1(1855)$ near the threshold offers a nice place to test its molecular nature. However, it should be better to take high energy, at least above $E_{\gamma }=16.97$ GeV, to observe the production of ${\eta }_1(1855)$ if ${\eta }_1(1855)$ is a $s\bar{s}g$ hybrid meson. These results can be measured in the GlueX experiment or Electron-Ion Collider in China to test the nature of the ${\eta }_1(1855)$.

   hep-phJ.Phys.G(2023)·8 citations
2. 02*

   Testing the Gallium Anomaly

   Patrick Huber🇺🇸

   We study the online detection by gallium capture of mono-energetic neutrinos produced by a ${}^{51}$Cr radioactive source in a scintillation experiment. We find that cerium-doped gadolinium aluminum gallium garnet (GAGG) is a suitable scintillator which contains about 21% of gallium per weight and has a high mass density and light yield. Combined with a highly efficient light detection system this allows tagging of the subsequent germanium decay and thus a clean distinction of gallium capture and elastic neutrino electron scattering events. With 1.5 tons of scintillator and 10 source runs of 3.4MCi, each, we obtain about 760 gallium capture events with a purity of 85% and 680,000 neutrino electron scattering events, where the latter provide a precise normalization independent of any nuclear physics. This configuration would allow to test the gallium anomaly at more than $5\sigma$ in an independent way.

   hep-phhep-exnucl-exPRD(2023)·14 citations
3. 03*

   Tetraquark mixing supported by the partial decay widths of two light-meson nonets

   Hungchong Kim🇰🇷 · K. S. Kim🇰🇷

   Recently, the tetraquark mixing framework has been proposed as a possible structure for the two light-meson nonets in the $J^P=0^{+}$ channel, the light nonet composed of $a_0(980)$, $K_0^{\ast }(700)$, $f_0(500)$, $f_0(980)$, and the heavy nonet of $a_0(1450)$, $K_0^{\ast }(1430)$, $f_0(1370)$, $f_0(1500)$. Among various signatures, we report in this work that their partial decay widths collected from various experimental data in Particle Data Group (PDG) can support this mixing scheme also. In particular, we demonstrate that the couplings of the light nonet to two pseudoscalar mesons estimated from the partial widths are consistently stronger than those of the heavy nonet. This consistent feature agrees qualitatively well with the predictions from the tetraquark mixing framework and, therefore, provides supporting evidence for the tetraquark mixing.

   hep-phhep-exnucl-exnucl-thEPJC(2022)·7 citations
4. 04*

   Primordial neutron star; a new candidate of dark matter

   M. Yoshimura🇯🇵

   Z-boson exchange interaction induces attractive force between left-handed neutrino and neutron. The Ginzburg-Landau mean field calculation and the Bogoliubov transformation suggest that this attractive force leads to neutrino-neutron pair condensate and super-fluidity. When the result of super-fluid formation is applied to the early universe, horizon scale pair condensate may become a component of dark energy. A further accretion of other fermions from thermal cosmic medium gives a seed of primordial neutron stars made of proton, neutron, electron, and neutrino in beta-equilibrium. Primordial neutron stars may provide a mechanism of giving a part or the whole of the dark matter in the present universe, if a properly chosen small fraction of cosmic thermal particles condenses to neutrino-neutron super-fluid and primordial neutron star not to over-close the universe. The proposal can be verified in principle by measuring neutrino burst at primordial neutron star formation and by detecting super-fluid relic neutrinos in atomic experiments at laboratories.

   hep-phastro-ph.COhep-th0 citations
5. 05*

   Particle species and energy dependencies of freeze-out parameters in high-energy proton-proton collisions

   Muhammad Waqas🇨🇳 · Guang Xiong Peng🇨🇳 · Fu-Hu Liu🇨🇳 · Muhammad Ajaz🇵🇰 · Abd Al Karim Haj Ismail🇦🇪 · Khusniddin K. Olimov🇺🇿 · Abdel Nasser Tawfik🇪🇬

   We used blast wave model with Tsallis statistics to analyze the experimental data measured by ALICE Collaboration in proton-proton collisions at Large Hadron Collider and extracted the related parameters (kinetic freeze-out temperature, transverse flow velocity and kinetic freeze-out volume of emission source) from transverse momentum spectra of the particles. We found that the kinetic freeze-out temperature and kinetic freeze-out volume are mass dependent. The former increase while the latter decrease with the particle mass which is the evidence of a mass as well as volume differential kinetic freeze-out scenario. Furthermore we extracted the mean transverse momentum and initial temperature by an indirect method and observed that they increase with mass of the particles. All the above discussed parameters are observed to increase with energy. Triton ($t$), hyper-triton (${}_{\bar{\Lambda }}^{3}H$) and helion (${}^{3}He$) and their anti-matter are observed to freeze-out at the same time due to isospin symmetry.

   hep-phnucl-thEur.Phys.J.Plus(2022)·6 citations
6. 06*

   Light Sterile Neutrinos, Left-Right Symmetry, and $0\nu \beta \beta$ Decay

   Jordy de Vries🇳🇱 · Gang Li🇨🇳 · Michael J. Ramsey-Musolf🇨🇳 · Juan Carlos Vasquez🇺🇸

   We investigate neutrinoless double beta ($0\nu \beta \beta$) decay rates in minimal left-right symmetric models in presence of relatively light right-handed neutrinos. By use of an effective field theory approach, we systematically include all contributions in the model as well as the dependence of the decay amplitude on the masses of right-handed neutrinos. In type-I and type-II seesaw scenarios, we analyze the impact of right-handed neutrinos heavier than about 10 MeV, showing that this effect can lead to a detection of $0\nu \beta \beta$ decay in the next-generation experiments even for the normal hierarchy and a relatively large right-handed scale set by the mass of hypothetical right-handed gauge bosons. Finally, we comment on a possible connection between light right-handed neutrinos and the strong CP problem.

   hep-phJHEP(2022)·24 citations
7. 07*

   NNLO Positivity Bounds on ChPT for a General Number of Flavours

   Benjamin Alvarez🇫🇷 · Johan Bijnens🇸🇪 · Mattias Sjö🇸🇪

   We present positivity bounds, derived from the principles of analyticity, unitarity and crossing symmetry, that constrain the low-energy constants of chiral perturbation theory. Bounds are produced for 2, 3 or more flavours with equal meson masses, up to and including next-to-next-to-leading order (NNLO), using the second and higher derivatives of the amplitude. We enhance the bounds by using the most general isospin combinations posible (or higher-flavour counterparts thereof) and by analytically integrating the low-energy range of the amplitude. In addition, we present a powerful and general mathematical framework for efficiently managing large numbers of positivity bounds.

   hep-phPoS(2024)·1 citation
8. 08*

   Addendum: Timelike and spacelike kernel functions for the hadronic vacuum polarization contribution to the muon anomalous magnetic moment (2022 J. Phys. G: Nucl. Part. Phys. 49 055001)

   A.V.Nesterenko

   This addendum provides results complementary to those obtained in [J. Phys. G49, 055001 (2022)]. Specifically, an equivalent form of the relation, which binds together the "spacelike" kernel functions for the hadronic vacuum polarization contribution to the muon anomalous magnetic moment $a_{\mu }^{\text{HVP}}$, is obtained. It is shown that the infrared limiting value of the "spacelike" and "timelike" kernel functions, which enter the representations for $a_{\mu }^{\text{HVP}}$ involving the Adler function and the $R$-ratio, is identical to the corresponding QED contribution to the muon anomalous magnetic moment of the preceding order in the electromagnetic coupling. The next-to-leading order contributions $a_{\mu }^{\text{HVP}(3b)}$ (which includes the leptonic and hadronic insertions) and $a_{\mu }^{\text{HVP}(3c)}$ (which includes the double hadronic insertion), are studied. The three kernel functions appearing in the representations for $a_{\mu }^{\text{HVP}(3b)}$, which involve the hadronic vacuum polarization function, Adler function, and the $R$-ratio, are presented for the cases of the electron and $\tau$-lepton loop insertions.

   hep-phJ. Phys. G50, 029401 (2023)
9. 09*

   Quantum current dissipation in superconducting strings and vortons

   Yoshihiko Abe🇯🇵 · Yu Hamada🇯🇵 · Kota Saji🇯🇵 · Koichi Yoshioka🇯🇵

   In this work, the current stability is discussed for cosmic strings with the bosonic superconductivity. A non-vanishing curvature of string generally induce the quantum instability of the current-carrying particle. Its decay rates are explored for various types of model parameters, curved string shapes, and decay processes. As a cosmological application, the stability is examined for superconducting strings in the string network and also for cosmic vortons by evaluating their cosmological evolution. The zero mode and hence the vorton cannot be stable in various cases, e.g., with a hierarchy between the current-carrying particle mass off the string and the string tension or with sizable couplings of the current-carrying particle to light species such as the Standard Model particles.

   hep-phastro-ph.COhep-thJHEP(2023)·13 citations
10. 10*

    Probing Supersymmetry Breaking Scale with Atomic Clocks

    Victor V. Flambaum🇦🇺 · Xuewen Liu🇨🇳 · Igor Samsonov🇦🇺 · Lei Wu🇨🇳 · Bin Zhu🇨🇳

    The supersymmetry (SUSY) breaking mechanism generally predicts the existence of the sgoldstinos, which can play the role of wave-like dark matter. Due to the ubiquitous coupling to the electromagnetic fields, the light scalar sgoldstino dark matter can lead to the variance of the fine-structure constant. With the precise atomic clock data, we find the SUSY breaking scale $\sqrt{F}$ can be probed up to the GUT scale in the sgoldstino mass range of $10^{-22}$ eV $<m_{\varphi }<$ $4\times 10^{-7}$ eV.

    hep-phquant-phNPB(2023)·6 citations
11. 11*

    Exploring dark $Z_d$-boson in future Large Hadron-electron collider

    Ashok Goyal🇮🇳 · Mukesh Kumar🇿🇦 · Satendra Kumar🇮🇳 · Rafiqul Rahaman🇮🇳

    The interaction between the dark $U(1{)}_d$ sector with the visible Standard Model (SM) sector takes place through the kinetic mixing between the dark photon $U(1{)}_d$ field $Z_d^{\mu }$ and the SM $U(1{)}_Y$ gauge field $B_{\mu }$. After the electroweak and $U(1{)}_d$ symmetry breaking, the dark photon $Z_d^{\mu }$ acquires a mass and mixes with the SM neutral vector boson $Z_{\mu }$. This mixing leads to parity-violating coupling between the $Z_d^{\mu }$ and SM. The coupling between the dark photon and SM can be explored in low energy phenomenology as well as in collider experiments. The Lorentz structure of dark photon interaction with SM fermions is explored in the proposed high energy future Large Hadron-electron collider, which would provide efficient energy and a clean environment using cross-section and asymmetries associated with polarisation observable of the dark photon in leptons decay. A ${\chi }^2$-analysis is performed to compare the strength of various variables for both the charge- and neutral-current processes. Based on this analysis, $90\%$ confidence level (C.L.) contours in the $ϵ$-$m_{Z_d}$ and $ϵ$-$g_V$ plane are obtained to put limits on the $Z_d^{\mu }$ mass up to $100$ GeV, coupling strength $ϵ$ and on the Lorentz structure of dark photon coupling with the SM fermions ($g_V$) at $\sqrt{s}\approx 1.3$ TeV.

    hep-phEPJC(2023)·3 citations
12. 12*

    Flavour anti-$k_{\text{T}}$ algorithm applied to $Wb\bar{b}$ production at the LHC

    Heribertus Bayu Hartanto🇬🇧 · Rene Poncelet🇬🇧 · Andrei Popescu🇬🇧 · Simone Zoia🇮🇹

    We apply the recently proposed flavoured anti-$k_{\text{T}}$ jet algorithm to $Wb\bar{b}$ production at the Large Hadron Collider at $\sqrt{s}=8$ TeV. We present results for the total cross section and differential distributions at the next-to-next-to-leading order (NNLO) in QCD. We discuss the effects of the remaining parametric freedom in the flavoured anti-$k_{\text{T}}$ prescription, and compare it against the standard flavour-$k_{\text{T}}$ algorithm. We compare the total cross section results against the CMS data, finding good agreement. The NNLO QCD corrections are significant, and their inclusion substantially improves the agreement with the data.

    hep-ph24 citations
13. 13*

    Laboratory Constraints on the Neutron-Spin Coupling of feV-scale Axions

    Junyi Lee🇨🇳 · Mariangela Lisanti🇺🇸 · William A. Terrano🇺🇸 · Michael Romalis🇺🇸

    Ultralight axion-like particles can contribute to the dark matter near the Sun, leading to a distinct, stochastic signature in terrestrial experiments. We search for such particles through their neutron-spin coupling by re-analyzing approximately 40 days of data from a K-${}^3$He co-magnetometer with a new frequency-domain likelihood-based formalism that properly accounts for stochastic effects over all axion coherence times relative to the experimental time span. Assuming that axions make up all of the dark matter in the Sun's vicinity, we find a median 95% upper limit on the neutron-spin coupling of $2.4\times 10^{-10}$ GeV${}^{-1}$ for axion masses from 0.4 to 4 feV, which is about five orders of magnitude more stringent than previous laboratory bounds in that mass range. Although several peaks in the experiment's magnetic power spectrum suggest the rejection of a white-noise null hypothesis, further analysis of their lineshapes yields no positive evidence for a dark matter axion.

    hep-phastro-ph.COphysics.atom-phPRX(2023)·74 citations
14. 14*

    Model-Agnostic Exploration of the Mass Reach of Precision Higgs Boson Coupling Measurements

    Michael E. Peskin🇺🇸

    To understand the possibility for precision Higgs boson coupling measurements to access effects of very heavy new particles, I present five scenarios in which significant deviations in Higgs boson couplings are produced by new particles with multi-TeV masses. These scenarios indicate that such precision measurements provide opportunities to reach well beyond the capabilities of direct particle searches at the HL-LHC.

    hep-phhep-ex5 citations
15. 15*

    UV/IR Mixing, Causal Diamonds and the Electroweak Hierarchy Problem

    Thomas W. Kephart🇺🇸 · Heinrich Päs🇩🇪

    UV/IR Mixing is an umbrella term for phenomena in which high and low energy physics does not decouple as expected and may offer new perspectives on the electroweak hierarchy problem, i.e. the apparent unnaturally large hierarchy between the electroweak and the Planck scales. Based on how UV/IR mixing has been employed in the Cohen-Kaplan-Nelson bound and advocated as a solution to the cosmological constant problem, we argue that in the Higgs system causal diamonds replace the cosmic horizon as an infrared bound for effective field theory and show how this ansatz may help to explain the large hierarchy between the electroweak and the Planck scale.

    hep-phhep-thMod.Phys.Lett.A(2025)·7 citations
16. 16*

    Single Vector-Like top quark production via chromomagnetic interactions at present and future hadron colliders $-$A Snowmass 2021 White Paper

    Alexander Belyaev🇬🇧 · R. Sekhar Chivukula🇺🇸 · Benjamin Fuks🇫🇷 · Elizabeth H. Simmons🇺🇸 · Xing Wang🇺🇸

    In our recent paper, we have investigated the potential for the LHC to discover vector-like quark partner states singly produced via their chromomagnetic moment interactions. These production mechanisms extend traditional searches which rely on pair-production of top-quark partner states or on the single production of these states through electroweak interactions, in the sense of providing greatly increased reach in parameter space regions where traditional searches are insensitive. In this study we determine the potential of both the 14 TeV high-luminosity LHC (HL-LHC) and a 100 TeV proton-proton collider to probe new vector-like quarks produced in this mode. We focus on the single production of a top-quark partner in association with an ordinary top-quark, as well as on the resonant production of the bottom-quark partner with its subsequent decay to a top-quark partner and a $W$ boson. For both cases we consider a top-partner decay to the Higgs boson and an ordinary top-quark. We find that HL-LHC and a future 100 TeV proton collider can probe vector-like partner masses up to about 3 TeV and 15-20 TeV respectively, visibly extending the range of the traditional vector like quark partner searches.

    hep-phhep-ex5 citations
17. 17*

    Report of the Topical Group on Neutrino Properties for Snowmass 2021

    Carlo Giunti🇮🇹 · Julieta Gruszko🇺🇸 · Benjamin Jones🇺🇸 · Lisa Kaufman🇺🇸 · Diana Parno🇺🇸 · Andrea Pocar🇺🇸

    Neutrinos are the most elusive among the known elementary particles, because of their feeble interactions with ordinary matter. They are also the most mysterious, because of their tiny masses that suggest a novel mass generating mechanism, their unknown Dirac or Majorana nature, and their big quantum mixing leading to large-amplitude flavor oscillations. This Topical Group focuses on neutrino properties that are not directly investigated in other Topical Groups of the Neutrino Frontier: in particular, the absolute value of the neutrino masses, the Dirac or Majorana nature of neutrinos, their electromagnetic properties, their lifetime, and hypothetical exotic properties.

    hep-phhep-exnucl-exnucl-th15 citations
18. 18*

    No room to hide: implications of cosmic-ray upscattering for GeV-scale dark matter

    James Alvey🇳🇱 · Torsten Bringmann🇳🇴 · Helena Kolesova🇳🇴

    The irreducible upscattering of cold dark matter by cosmic rays opens up the intriguing possibility of detecting even light dark matter in conventional direct detection experiments or underground neutrino detectors. The mechanism also significantly enhances sensitivity to models with very large nuclear scattering rates, where the atmosphere and rock overburden efficiently stop standard non-relativistic dark matter particles before they could reach the detector. In this article, we demonstrate that cosmic-ray upscattering essentially closes the window for strongly interacting dark matter in the (sub-)GeV mass range. Arriving at this conclusion crucially requires a detailed treatment of both nuclear form factors and inelastic dark matter-nucleus scattering, as well as including the full momentum-transfer dependence of scattering amplitudes. We illustrate the latter point by considering three generic situations where such a momentum-dependence is particularly relevant, namely for interactions dominated by the exchange of light vector or scalar mediators, respectively, and for dark matter particles of finite size. As a final concrete example, we apply our analysis to a putative hexaquark state, which has been suggested as a viable baryonic dark matter candidate. Once again, we find that the updated constraints derived in this work close a significant part of otherwise unconstrained parameter space.

    hep-phastro-ph.COJHEP(2023)·54 citations
19. 19*

    Axion Dark Matter from Lepton flavor-violating Decays

    Paolo Panci🇮🇹 · Diego Redigolo🇮🇹 · Thomas Schwetz🇩🇪 · Robert Ziegler🇩🇪

    We propose simple scenarios where lepton flavor-violating couplings generate the observed dark matter abundance through freeze-in of an axion-like particle with mass in the few keV range. Compared to flavor-diagonal freeze-in, this mechanism enhances dark matter stability, softens stellar cooling constraints and improves the experimental sensitivity of accelerator-based searches. These scenarios can be tested by future X-ray telescopes, and in some cases will be almost entirely probed by new searches for lepton flavor violation at high-intensity experiments such as Mu3e and MEG II.

    hep-phPLB(2023)·45 citations
20. 20*

    Majorana versus Dirac Constraints on the Neutrino Dipole Moments

    André de Gouvêa🇺🇸 · Giancarlo Jusino Sánchez🇺🇸 · Pedro A.N. Machado🇺🇸 · Zahra Tabrizi🇺🇸

    Massive neutrinos are guaranteed to have nonzero electromagnetic moments and, since there are at least three neutrino species, these dipole moments define a matrix. Here, we estimate the current upper bounds on all independent neutrino electromagnetic moments, concentrating on Earth-bound experiments and measurements with solar neutrinos, including the very recent results reported by XENONnT. We make no simplifying assumptions and compare the hypotheses that neutrinos are Majorana fermions or Dirac fermions. In particular, we fully explore constraints in the Dirac-neutrino parameter space. Majorana and Dirac neutrinos are different; for example, the upper bounds on the magnitudes of the elements of the dipole moment matrix are weaker for Dirac neutrinos, relative to Majorana neutrinos. The potential physics reach of next-generation experiments also depends on the nature of the neutrino. We find that a next-generation experiment two orders of magnitude more sensitive to the neutrino electromagnetic moments via ${\nu }_{\mu }$ elastic scattering may discover that the neutrino electromagnetic moments are nonzero if the neutrinos are Dirac fermions. Instead, if the neutrinos are Majorana fermions, such a discovery is ruled out by existing solar neutrino data, unless there are more than three light neutrinos.

    hep-phhep-th9 citations
21. 21*

    (In)Visible signatures of the minimal dark abelian gauge sector

    Ana Luisa Foguel🇧🇷 · Gabriel M. Salla🇧🇷 · Renata Zukanovich Funchal🇧🇷

    In this paper we study the present and future sensitivities of the rare meson decay facilities KOTO, LHCb and Belle II to a light dark sector of the minimal dark abelian gauge symmetry where a dark Higgs $S$ and a dark photon $Z_D$ have masses $\lesssim 10$ GeV. We have explored the interesting scenario where $S$ can only decay to a pair of $Z_D$'s and so contribute to visible or invisible signatures, depending on the life-time of the latter. Our computations show that these accelerator experiments can access the dark Higgs (mass and scalar mixing) and the dark photon (mass and kinetic mixing) parameters in a complementary way. We have also discussed how the CMS measurement of the SM Higgs total decay width and their limit on the Higgs invisible branching ratio can be used to extend the experimental reach to dark photon masses up to $\sim 10$ GeV, providing at the same time sensitivity to the gauge coupling associated with the broken dark abelian symmetry.

    hep-phJHEP(2022)·20 citations
22. 22*

    Probing ultralight scalar, vector and tensor dark matter with pulsar timing arrays

    Caner Unal🇮🇱 · Federico R. Urban🇨🇿 · Ely D. Kovetz🇮🇱

    Pulsar timing arrays (PTAs) are sensitive to oscillations in the gravitational potential along the line-of-sight due to ultralight particle pressure. We calculate the probing power of PTAs for ultralight bosons across all frequencies, from those larger than the inverse observation time to those smaller than the inverse distance to the pulsar. We show that since the signal amplitude grows comparably to the degradation in PTA sensitivity at frequencies smaller than inverse observation time, the discovery potential can be extended towards lower masses by over three decades, maintaining high precision. We demonstrate that, in the mass range $10^{-26}-10^{-23}$ eV, existing 15-year PTA data can robustly detect or rule out an ultralight component down to $O(1-10)\%$ of the total dark matter. Non-detection, together with other bounds in different mass ranges, will imply that ultralight scalar/axion can comprise at most $1-10\%$ of dark matter in the $10^{-30}-10^{-17}$ eV range. With 30 years of observation, current PTAs can extend the reach down to $0.1-1\%$, while next-generation PTAs such as SKA can attain the $0.01-0.1\%$ precision. We generalize the analysis and derive predictions for ultralight spin-1 vector (i.e. dark photon) and spin-2 tensor dark components.

    ↳ astro-ph.COastro-ph.HEhep-phhep-thPLB(2024)·29 citations
23. 23*

    Denominator Regularization in Quantum Field Theory

    W. A. Horowitz🇿🇦

    We propose a novel regularization scheme in quantum field theory, denominator regularization (den reg). As simple to apply as dimensional regularization, and similarly compatible with a minimal subtraction renormalization scheme, den reg manifestly 1) maintains Lorentz invariance, 2) maintains gauge invariance, 3) maintains supersymmetry, 4) correctly predicts the axial anomaly, and 5) yields Green functions that satisfy the Callan-Symanzik equation. Den reg also naturally enables regularization in asymmetric spacetimes, finite spacetimes, curved spacetimes, and in thermal field theory.

    ↳ hep-thcond-mat.stat-mechhep-phnucl-th8 citations
24. 24*

    CFTs with $U(m)\times U(n)$ Global Symmetry in 3D and the Chiral Phase Transition of QCD

    Stefanos R. Kousvos🇮🇹 · Andreas Stergiou🇬🇧

    Conformal field theories (CFTs) with $U(m)\times U(n)$ global symmetry in $d=3$ dimensions have been studied for years due to their potential relevance to the chiral phase transition of quantum chromodynamics (QCD). In this work such CFTs are analyzed in $d=4-\epsilon$ and $d=3$. This includes perturbative computations in the $\epsilon$ and large-$n$ expansions as well as non-perturbative ones with the numerical conformal bootstrap. New perturbative results are presented and a variety of non-perturbative bootstrap bounds are obtained in $d=3$. Various features of the bounds obtained for large values of $n$ disappear for low values of $n$ (keeping $m<n$ fixed), a phenomenon which is attributed to a transition of the corresponding fixed points to the non-unitary regime. Numerous bootstrap bounds are found that are saturated by large-$n$ results, even in the absence of any features in the bounds. A double scaling limit is also observed, for $m$ and $n$ large with $m/n$ fixed, both in perturbation theory as well as in the numerical bootstrap. For the case of two-flavor massless QCD existing bootstrap evidence is reproduced that the chiral phase transition may be second order, albeit associated to a universality class unrelated to the one usually discussed in the $\epsilon$ expansion. Similar evidence is found for the case of three-flavor massless QCD, where we observe a pronounced kink.

    ↳ hep-thcond-mat.str-elhep-lathep-phSciPost Phys.(2023)·28 citations
25. 25*

    Strange mesons in nuclei and neutron stars

    Laura Tolos🇪🇸

    The present status in the field of strange mesons in nuclei and neutron stars is reviewed. In particular, the $\bar{K}N$ interaction, that is governed by the presence of the $\Lambda (1405)$, is analyzed and the formation of the $\bar{K}NN$ bound state is discussed. Moreover, the properties of $\bar{K}$ in dense nuclear matter are studied, in connection with strangeness production in nuclear collisions and kaon condensation in neutron stars.

    ↳ nucl-thhep-exhep-phEPJ Web Conf.(2022)·0 citations
26. 26*

    Hadronic vacuum polarization correction to atomic energy levels

    Sören Breidenbach🇩🇪 · Eugen Dizer🇩🇪 · Halil Cakir🇩🇪 · Zoltán Harman🇩🇪

    The shift of atomic energy levels due to hadronic vacuum polarization is evaluated in a semiempirical way for hydrogenlike ions and for muonic hydrogen. A parametric hadronic polarization function obtained from experimental cross sections of $e^{-}{e}^{+}$ annihilation into hadrons is applied to derive an effective relativistic Uehling potential. The energy corrections originating from hadronic vacuum polarization are calculated for low-lying levels using analytical Dirac-Coulomb wave functions, as well as bound wave functions accounting for the finite nuclear size. Closed formulas for the hadronic Uehling potential of an extended nucleus as well as for the relativistic energy shift in case of a point-like nucleus are derived. These results are compared to existing analytic formulas from non-relativistic theory.

    ↳ quant-phhep-phphysics.atom-phPRA(2022)·14 citations
27. 27*

    Center-of-mass energy determination using $e^{+}{e}^{-}$ to ${\mu }^{+}{\mu }^{-}$ $(\gamma )$ events at future $e^{+}{e}^{-}$ colliders

    Brendon Madison🇺🇸 · Graham W. Wilson🇺🇸

    Methods for measuring the absolute center-of-mass energy, $\sqrt{s}$, and its distribution, are investigated for future $e^{+}{e}^{-}$ Higgs-factory colliders using in situ $e^{+}{e}^{-}$ collisions. We emphasize the potential of an estimator based on the measurement of muon momenta that we denote ${\sqrt{s}}_p$. It can be determined with high precision in $e^{+}{e}^{-}$ to ${\mu }^{+}{\mu }^{-}$($\gamma$) events while being sensitive to effects from beam energy spread, beamstrahlung, initial-state radiation (ISR), final-state radiation (FSR), crossing angle, and detector resolution. The measurement precision is enabled by a high-precision low-mass tracker; the reported performance estimates are based on full simulation of the tracker response of the ILD detector concept for the ILC operating at $\sqrt{s}=250$ GeV. The underlying statistical precision is 1.9 ppm for a 2.0 ab${}^{-1}$ dataset at ILC. The ultimate utility will depend largely on how well one can calibrate and maintain the tracker momentum scale.

    ↳ hep-exhep-phphysics.acc-ph7 citations
28. 28*

    Tunneling Potential Actions from Canonical Transformations

    José R. Espinosa🇪🇸 · Ryusuke Jinno🇪🇸 · Thomas Konstandin🇩🇪

    A new formulation for obtaining the tunneling action for vacuum decay based on the so-called tunneling potential was developed recently. In the original derivation, the new action was obtained by requiring that its variation led to the correct equations of motion and the same value for the action as evaluated on the Euclidean bounce. We present an alternative derivation of the tunneling potential action via canonical transformations. We discuss both single-field and multi-field cases as well as the case with gravity. We also comment on the possible application of the new approach to the calculation of the functional determinant prefactor in the tunneling rate.

    ↳ hep-thhep-phJCAP(2023)·9 citations
29. 29*

    Circuit Complexity in an interacting quenched Quantum Field Theory

    Sayantan Choudhury🇮🇳 · Rakshit Mandish Gharat🇮🇳 · Saptarshi Mandal🇮🇳 · Nilesh Pandey🇮🇳

    In this work, we explore the effects of a quantum quench on the circuit complexity for a quenched quantum field theory having weakly coupled quartic interaction. We use the invariant operator method, under a perturbative framework, for computing the ground state of this system}. We give the analytical expressions for specific reference and target states using the ground state of the system. Using a particular cost functional, we show the analytical computation of circuit complexity for the quenched and interacting field theory. Further, we give a numerical estimate of circuit complexity with respect to the quench rate, $\delta t$ for two coupled oscillators. The parametric variation of the unambiguous contribution of the circuit complexity for an arbitrary number of oscillators has been studied with respect to the dimensionless parameter $(t/\delta t$). We comment on the variation of circuit complexity for different values of coupling strength, different number of oscillators, and even in different dimensions.

    ↳ hep-thcond-mat.stat-mechgr-qchep-ph+1Symmetry(2023)·10 citations
30. 30*

    Investigation of the freeze-out parameters in B-B, O-O, Ca-Ca and Au-Au collisions at 39 GeV

    Muhammad Waqas🇵🇰 · Guang Xiong Peng🇨🇳 · Fu-Hu Liu🇨🇳 · Muhammad Ajaz · Abd Al Karim Haj Ismail🇦🇪

    We analyzed the transverse momentum spectra of proton, deuteron and triton in Boron-Boron (B-B), Oxygen-Oxygen (O-O), and Calcium-Calcium (Ca-Ca) central collisions, as well as in several centrality bins in Gold-Gold (Au-Au) collisions at 39 GeV by using the blast wave model with Tsallis statistics. The bulk properties in terms of kinetic freeze-out temperature, transverse flow velocity and kinetic freeze-out volume are extracted from the model by the least square method. We observed that with increasing the rest mass of the particle, the kinetic freeze-out temperature becomes larger, while transverse flow velocity and the kinetic freeze-out volume reduces. These parameters are also found to depend on the size of the system. Larger the size of the system, the larger they are. Furthermore, the kinetic freeze-out temperature in peripheral Au-Au collisions is close to the central O-O collisions. We also observed that the above parameters depend on the centrality, and they decrease from central to peripheral collisions. Besides, we also extracted the entropy-index parameter $q$, and the parameter $N_0$ which shows the multiplicity. Both of them depend on the size of interacting the system, rest mass of the particle and centrality. Both $q$ and $N_0$ are larger for lighter particles, and the former is smaller for large systems while the latter is larger, and the former decrease with increasing centrality while the latter increase.

    ↳ nucl-thhep-phEur.Phys.J.Plus(2022)·7 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.