Wed·Nov 2, 2022Wednesday·November 2, 2022

1. 01*

   A Sum-Rules Analysis of Next-to-Leading-Order (NLO) QCD Perturbative Contributions to a $J^{PC}=0^{+-}$, $du\bar{d}\bar{u}$ Tetraquark Correlator

   K. Ray🇨🇦 · D. Harnett🇨🇦 · T. G. Steele🇨🇦

   We calculated next-to-leading-order (NLO) QCD perturbative contributions to a $J^{PC}=0^{+-}$, $du\bar{d}\bar{u}$ tetraquark (diquark-antidiquark) correlator in the chiral limit of massless $u$ and $d$ quarks. At NLO, there are four quark self-energy diagrams and six gluon-exchange diagrams. Nonlocal divergences were cancelled using diagrammatic renormalization. Dimensionally regularized integrals were numerically computed using pySecDec. The combination of pySecDec with diagrammatic renormalization establishes a valuable new methodology for NLO calculations of QCD correlation functions. Compared to leading-order (LO) perturbation theory, we found that NLO perturbation theory is significant. To quantify the impact of NLO perturbation theory on physical predictions, we computed NLO perturbative contributions to QCD Laplace, Gaussian, and finite-energy sum rules. Using QCD sum rules, we determined upper and lower bounds on the $0^{+-}$, $du\bar{d}\bar{u}$ tetraquark ground-state mass, $M$: at NLO in perturbation theory, we found $2.2\text{GeV}\lesssim M\le 4.2\text{GeV}$ whereas, at LO, we found $2.4\text{GeV}\lesssim M\le 4.6\text{GeV}$. This mass range suggests the possibility of mixing between $0^{+-}$, light-quark (i.e., $u$ and $d$ quarks) hybrid and $du\bar{d}\bar{u}$ tetraquark states. Taking into account uncertainties in QCD parameters, we found no evidence for a $0^{+-}$, $du\bar{d}\bar{u}$ tetraquark under 1.9 GeV.

   hep-phPRD(2023)·6 citations
2. 02*

   Probe the Mixing Parameter $|V_{\tau N}{|}^2$ for Heavy Neutrinos

   Lingxiao Bai🇨🇳 · Ying-nan Mao🇨🇳 · Kechen Wang🇨🇳

   Because of the difficulty in detecting final state taus, the mixing parameter $|V_{\tau N}{|}^2$ for heavy neutrino $N$ is not well studied at current experiments, compared with other mixing parameters $|V_{eN}{|}^2$ and $|V_{\mu N}{|}^2$. In this paper, we focus on a challenging scenario where $N$ mixes with active neutrino of tau flavour only, i.e. $|V_{\tau N}{|}^2\ne 0$ and $|V_{eN}{|}^2=|V_{\mu N}{|}^2=0$. We derive current constraints on $|V_{\tau N}{|}^2$ from the rare $Z$-boson decay and electroweak precision data (EWPD). To forecast the future limits, we also investigate the signal $pp\to {\tau }^{\pm }{\tau }^{\pm }jj$ via a Majorana heavy neutrino at future proton-proton colliders. To suppress the background, both taus are required to decay leptonically into muons, leading to the final state containing two same sign muons, at least two jets plus moderate missing energy. The signal and relevant background processes are simulated at the HL-LHC and SppC/FCC-hh with center-of-mass energy of 14 TeV and 100 TeV. The preselection and multivariate analyses based on machine-learning are performed to reduce background. Limits on $|V_{\tau N}{|}^2$ are shown for heavy neutrino mass in the range 10-1000 GeV based on measurements from the rare $Z$-boson decay and EWPD, and searches at the HL-LHC and SppC/FCC-hh with integrated luminosities of 3 and 20 ab${}^{-1}$.

   hep-phhep-exPRD(2023)·5 citations
3. 03*

   Geometric Phases in Kaon Decays and Baryogenesis

   Swarup Sangiri🇮🇳 · Utpal Sarkar🇮🇳

   We studied the formalism for construction of Bargmann invariants (BIs) as quantum mechanical geometric phases and identified the CP invarince with the rephasing invariant phases in neutral kaon system, kaon decays, baryogenesis and leptogenesis. We develop this formalism to express the CP violation in terms of the Bargmann invariants, which allow us to interpret them as geometric phases. We then comment on the application of such generalized treatment of CP phases.

   hep-phNPB(2023)·7 citations
4. 04*

   PeV-scale leptogenesis, gravity waves and black holes from a SUSY-breaking phase transition

   James M. Cline🇨🇦 · Benoit Laurent🇨🇦 · Stuart Raby🇺🇸 · Jean-Samuel Roux🇨🇦

   Supersymmetry is a highly motivated theoretical framework, whose scale of breaking may be at PeV energies, to explain null searches at the Large Hadron Collider. SUSY breaking through a first order phase transition may have occurred in the early universe, leading to potential gravitational wave signals. Constructing a realistic model for gauge-mediated supersymmetry breaking, we show that such a transition can also induce masses for heavy right-handed neutrinos and sneutrinos, whose CP-violating decays give leptogenesis at the PeV scale, and a novel mechanism of neutrino mass generation at one loop. For the same models we predict the possible gravity wave signals, and we study the possibility of production of primordial black holes during the phase transition.

   hep-phastro-ph.COPRD(2023)·7 citations
5. 05*

   PELICAN: Permutation Equivariant and Lorentz Invariant or Covariant Aggregator Network for Particle Physics

   Alexander Bogatskiy🇺🇸 · Timothy Hoffman🇺🇸 · David W. Miller🇺🇸 · Jan T. Offermann🇺🇸

   Many current approaches to machine learning in particle physics use generic architectures that require large numbers of parameters and disregard underlying physics principles, limiting their applicability as scientific modeling tools. In this work, we present a machine learning architecture that uses a set of inputs maximally reduced with respect to the full 6-dimensional Lorentz symmetry, and is fully permutation-equivariant throughout. We study the application of this network architecture to the standard task of top quark tagging and show that the resulting network outperforms all existing competitors despite much lower model complexity. In addition, we present a Lorentz-covariant variant of the same network applied to a 4-momentum regression task.

   hep-phcs.LGhep-ex64 citations
6. 06*

   Systematic analysis of doubly charmed baryons ${\Xi }_{cc}$ and ${\Omega }_{cc}$

   Guo-Liang Yu🇨🇳 · Zhen-Yu Li🇨🇳 · Zhi-Gang Wang🇨🇳 · Jie Lu🇨🇳 · Meng Yan🇨🇳

   In this work, we perform a systematic study of the mass spectra, the root mean square(r.m.s.) radii and the radial density distributions of the doubly charmed baryons ${\Xi }_{cc}$ and ${\Omega }_{cc}$. The calculations are carried out in the frame work of Godfrey-Isgur (GI) relativized quark model, where the baryon is regarded as a real three-body system of quarks. Our results show that the excited energy of doubly charmed baryon with $\rho$-mode is lower than those of the $\lambda$-mode and $\lambda$-$\rho$ mixing mode, which indicates that the lowest state is dominated by the $\rho$-mode. According to this conclusion, we systematically investigate the mass spectra, the r.m.s. radii of the ground and excited states($1S\sim 4S$, $1P\sim 4P$, $1D\sim 4D$, $1F\sim 4F$ and $1G\sim 4G$) with $\rho$-mode. Using the wave functions obtained from quark model, we also study the radial density distributions. Finally, with the predicated mass spectra, the Regge trajectories of ${\Xi }_{cc}$ and ${\Omega }_{cc}$ in the ($J$,$M^2$) plane are constructed, and the slopes, intercepts are determined by linear fitting. It is found that model predicted masses fit nicely to the constructed Regge trajectories.

   hep-phEPJA(2023)·22 citations
7. 07*

   Axion effects on gamma-ray spectral irregularities with AGN redshift uncertainty

   Hai-Jun Li🇨🇳 · Wei Chao🇨🇳

   We investigate the photon-axionlike particle (ALP) oscillation effects on TeV gamma-ray spectral irregularities from the uncertain redshift active galactic nuclei (AGN) VER J0521+211. The gamma-ray spectra are measured by Fermi-LAT and VERITAS with the three flux states in 2013 and 2014. We set the combined constraints on the ALP parameter ($m_a,g_{a\gamma }$) space with these states and test the extragalactic background light (EBL) absorption effect on ALP constraints with the redshift limit scenarios $z_0\sim \mathcal{O}(0.1-0.3)$. The 99% $C.L.$ photon-ALP combined constraints set by VER J0521+211 are roughly at $g_{a\gamma }\gtrsim 2.0\times 10^{-11}\mathrm{Ge}{\mathrm{V}}^{-1}$ for $1.0\times 10^{-9}\mathrm{eV}\lesssim m_a\lesssim 1.0\times 10^{-7}\mathrm{eV}$. We find no clear connection between the redshift limit scenarios and the photon-ALP constraints. Both the underestimated and overestimated redshifts can affect the constraint results.

   hep-phastro-ph.HEPRD(2023)·12 citations
8. 08*

   Low-mass doubly-charged Higgs bosons at LHC

   Saiyad Ashanujjaman🇮🇳 · Kirtiman Ghosh🇮🇳 · Rameswar Sahu🇮🇳

   Search for light (within the mass range 84-200 GeV) doubly-charged Higgs bosons decaying into a pair of W-bosons has been deemed challenging using the conventional LHC searches with leptons, jets and missing transverse momentum in the final state. Such Higgses together with slightly heavier singly-charged and neutral Higgses, when arranged in an $SU(2{)}_L$ triplet as in the type-II see-saw model, are lately shown to accommodate the recent measurement of the $W$-boson mass by the CDF collaboration. These, when produced in a highly Lorentz-boosted regime, tend to manifest themselves as a single fat-jet or a pair of adjacent same-sign leptons plus missing transverse momentum. First, we perform a multivariate analysis to discern such exotic jets from the SM jets. Then, we present a novel search in the final state with an exotic jet and two same-sign leptons plus missing transverse momentum. We find that such low-mass doubly-charged Higgsses could be directly probed with the already collected Run 2 LHC data.

   hep-phPRD(2023)·24 citations
9. 09*

   GRB 221009A Gamma Rays from Radiative Decay of Heavy Neutrinos?

   Alexei Y. Smirnov🇩🇪 · Andreas Trautner🇩🇪

   We consider a mechanism which allows to decrease attenuation of high energy gamma ray flux from gamma ray burst GRB 221009A. The mechanism is based on the existence of a heavy $m_N\sim 0.1\mathrm{MeV}$ mostly sterile neutrino $N$ which mixes with active neutrinos. $N$'s are produced in GRB in $\pi$ and $K$ decays via mixing with ${\nu }_{\mu }$. They undergo the radiative decay $N\to \nu \gamma$ on the way to the Earth. The usual exponential attenuation of gamma rays is lifted to an attenuation inverse in the optical depth. Various restrictions on this scenario are discussed. We find that the high energy $\gamma$ events at $18\mathrm{TeV}$ and potentially $251\mathrm{TeV}$ can be explained if (i) the GRB active neutrino fluence is close to the observed limit, (ii) the branching ratio of $N\to \nu \gamma$ is at least of the order 10%.

   hep-phastro-ph.HEPRL(2023)·29 citations
10. 10*

    Littlest Modular Seesaw

    Ivo de Medeiros Varzielas🇵🇹 · Steve F. King🇬🇧 · Miguel Levy🇵🇹

    We present the first complete model of the Littlest Modular Seesaw, based on two right-handed neutrinos, within the framework of multiple modular symmetries, justifying the use of multiple moduli fields which take their values at 3 specific stabilizers of ${\Gamma }_4\simeq S_4$, including a new phenomenological possibility. Using a semi-analytical approach, we perform a ${\chi }^2$ analysis of each case and show that good agreement with neutrino oscillation data is obtained, including predictive relations between the leptonic mixing angles and the ratio of light neutrino masses, which non-trivially agree with the experimental values. It is noteworthy that in this very predictive setup, the models fit the global fits of the experimental data remarkably well, both with and without the Super-Kamiokande atmospheric data, for both choices of stabilizers. By extending the model to include a weighton and the double cover group ${\Gamma }_4^{\prime }\simeq S_4^{\prime }$, we are able to also account for the hierarchy of the charged leptons using modular symmetries, without altering the neutrino predictions.

    hep-phJHEP(2023)·19 citations
11. 11*

    The irresistible call of $\tau =i$

    Ferruccio Feruglio🇮🇹

    We analyze a large set of modular invariant models of lepton masses and mixing angles, pointing out that many of them prefer to live close to the self-dual point $\tau =i$. We show that in the vicinity of this point a universal behavior naturally emerges, independently from details of the theory such as the finite modular group acting on the lepton multiplets, the weights of the matter multiplets and even the form of the kinetic terms, which are not required to be neither minimal nor flavour blind. The neutrino mass spectrum is normally ordered and universal relations describe the scaling of the physical observables in terms of the parameter $|\tau -i|$.

    hep-phhep-thPRL(2023)·44 citations
12. 12*

    Flavor-changing light bosons with accidental longevity

    Yohei Ema🇺🇸 · Zhen Liu🇺🇸 · Kun-Feng Lyu🇺🇸 · Maxim Pospelov🇺🇸

    We consider a model with a complex scalar field that couples to $(e,\mu )$ or $(\mu ,\tau )$ within the "longevity" window: $[|m_{l_1}-m_{l_2}|,m_{l_1}+m_{l_2}]$ in which $l_1$ and $l_2$ are the two different charged leptons. Within such a mass window, even a relatively large coupling (e.g. of the size commensurate with the current accuracy/discrepancy in the muon $g-2$ experiment) leads to long lifetimes and macroscopic propagation distance between production and decay points. We propose to exploit several existing neutrino experiments and one future experiment to probe the parameter space of this model. For the $\mu -e$ sector, we exploit the muonium decay branching ratio and the production and decay sequence at the LSND experiment, excluding the parametric region suggested by $g_{\mu }-2$ anomaly. For the $\tau -\mu$ sector, we analyze three main production mechanisms of scalars at beam dump experiments: the Drell-Yan process, the heavy meson decay, and the muon scattering. We explore the constraints from the past CHARM and NuTeV experiments, and evaluate sensitivity for the proposed beam dump experiment, SHiP. The latter can thoroughly probe the parameter space relevant for the $g_{\mu }-2$ anomaly.

    hep-phhep-exJHEP(2023)·7 citations
13. 13*

    Classical vs Quantum Eikonal Scattering and its Causal Structure

    Brando Bellazzini🇫🇷 · Giulia Isabella🇫🇷 · Massimiliano Maria Riva🇫🇷

    We study the eikonal scattering of two gravitationally interacting bodies, in the regime of large angular momentum and large center of mass energy. We show that eikonal exponentiation of the scattering phase matrix is a direct consequence of the group contraction $SU(2)\to ISO(2)$, from rotations to the isometries of the plane, in the large angular momentum limit. We extend it to all orders in the scattering angle, and for all masses and spins. The emergence of the classical limit is understood in terms of the continuous-spin representations admitted by $ISO(2)$. We further investigate the competing classical vs quantum corrections to the leading classical eikonal scattering, and find several interesting examples where quantum corrections are more important than Post-Minkowskian's. As a case of study, we analyse the scattering of a photon off a massless neutral scalar field, up to next-to-leading order in the Newton constant, and to leading order in the fine structure constant. We investigate the causal structure of the eikonal regime and establish an infinite set of non-linear positivity bounds, of which positivity of time delay is the simplest.

    ↳ hep-thgr-qchep-phJHEP(2023)·58 citations
14. 14*

    Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of ${\rho }^0$ mesons

    G. D. Alexeev · M. G. Alexeev · C. Alice · A. Amoroso · V. Andrieux · V. Anosov · K. Augsten · W. Augustyniak · C. D. R. Azevedo · B. Badelek · J. Barth · R. Beck and 180 other authors

    The production of vector mesons in deep inelastic scattering is an interesting yet scarsely explored channel to study the transverse spin structure of the nucleon and the related phenomena. The COMPASS collaboration has performed the first measurement of the Collins and Sivers asymmetries for inclusively produced ${\rho }^0$ mesons. The analysis is based on the data set collected in deep inelastic scattering in $2010$ using a $160\mathrm{GeV}/c$ ${\mu }^{+}$ beam impinging on a transversely polarized ${\mathrm{NH}}_3$ target. The ${\rho }^0$ mesons are selected from oppositely charged hadron pairs, and the asymmetries are extracted as a function of the Bjorken-$x$ variable, the transverse momentum of the pair and the fraction of the energy $z$ carried by the pair. Indications for positive Collins and Sivers asymmetries are observed.

    ↳ hep-exhep-phPLB(2023)·13 citations
15. 15*

    Ultra-high energy cosmic neutrinos from gamma-ray bursts

    Yanqi Huang🇨🇳 · Bo-Qiang Ma🇨🇳

    Based on recent proposal to associate IceCube TeV and PeV neutrino events with gamma-ray bursts~(GRBs) by considering the Lorentz violation of neutrinos, we provide a new estimate on the GRB neutrino flux and such result is much bigger than previous results by the IceCube Collaboration. Among these 24 neutrino ``shower" events above 60~TeV, 12 events are associated with GRBs. Such result is comparable with the prediction from GRB fireball models. Analysis of track events provide consistent result with the shower events to associate high energy cosmic neutrinos with GRBs under the same Lorentz violation features of neutrinos. We also make a background estimation and reveal GRBs as a significant source for the ultra-high energy IceCube neutrino events. Our work supports the Lorentz violation and $CPT$-violation of neutrinos, indicating new physics beyond relativity.

    ↳ astro-ph.HEgr-qchep-phFund.Res.(2024)·16 citations
16. 16*

    Vacuum energy, the Casimir effect, and Newton's non-constant

    Benjamin Koch🇦🇹 · Christian Käding🇦🇹 · Mario Pitschmann🇦🇹 · René Sedmik🇦🇹

    We explore two hypotheses. First, the possibility that the quantum vacuum energy density of the Casimir effect contributes to a (local) gravitational vacuum energy density. Second, the possibility that a change in the gravitational coupling implies a change in the cosmological constant. We parametrize these two possibilities in a covariant framework and show that the next generation of Casimir experiments does have a surprisingly good chance of exploring this parameter space.

    ↳ hep-thhep-phUniverse(2023)·6 citations
17. 17*

    The CGF dark matter fluid

    Daniel Friedan🇺🇸

    The cosmological gauge field (CGF) is a classical solution of SU(2)-weak gauge theory oscillating rapidly in time. It is the dark matter driving the CGF cosmology. A general, local, mathematically natural construction of the CGF is given here. The macroscopic properties are derived. The CGF is an irrotational perfect fluid. It provides a synchronized global time coordinate and a global rest frame. There is a conserved number density. The energy density and pressure are related by the same equation of state as derived in the CGF cosmology and used in the TOV stellar structure equations for stars made of CGF dark matter. The present construction justifies the TOV solution. Some possible routes towards testing the theory are suggested at the end.

    ↳ physics.gen-phastro-ph.COgr-qchep-ph+11 citation

* 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.