Mon·Apr 25, 2022Monday·April 25, 2022

1. 01*

   Probing Heavy Sterile Neutrinos at Ultrahigh Energy Neutrino Telescopes via the Dipole Portal

   Guo-yuan Huang🇩🇪 · Sudip Jana🇩🇪 · Manfred Lindner🇩🇪 · Werner Rodejohann🇩🇪

   The question of how heavy a sterile neutrino can be probed in experiments leads us to investigate the Primakoff production of heavy sterile neutrinos up to PeV masses from ultrahigh-energy neutrinos via the magnetic dipole portal. Despite the suppression from the small magnetic moment, the transition is significantly enhanced by tiny $t$-channel momentum transfers, similar to the resonant production of pions and axions in an external electromagnetic field. Based on the current IceCube measurement of astrophysical neutrinos up to PeV energies, strong constraints can already be derived on the transition magnetic moments of sterile neutrinos up to TeV masses. Moreover, we investigate the sensitivity of future tau neutrino telescopes, which are designed for EeV cosmogenic neutrino detection. We find that sterile neutrino masses as large as $30\mathrm{TeV}$ can be probed at tau neutrino telescopes such as GRAND, POEMMA, and Trinity.

   hep-phastro-ph.HEPLB(2023)·27 citations
2. 02*

   Exclusive $Z^0$ production in $ep$ and $eA$ collisions at high energies

   G. M. Peccini🇧🇷 · L. S. Moriggi🇧🇷 · M. V. T. Machado🇧🇷

   In this work the $k_{\perp }$-factorization formalism is applied to compute the exclusive $Z^0$ boson photoproduction in $ep$ and $eA$ collisions. The study is also extended to $pp$ and $AA$ processes. The nuclear effects are investigated considering heavy and light ions. Analytical models for the unintegrated gluon distribution are taken into account and the corresponding theoretical uncertainty is quantified. The analysis is done for electron-ion collisions at the Large Hadron-Electron Collider (LHeC), its high-energy upgrade (HE-LHeC) and at the Future Circular Collider (FCC) in lepton-hadron mode. Additionally, ultra-peripheral heavy ion collisions at future runs of the Large Hadron Collider (LHC) and at the FCC (hadron-hadron mode) are also considered.

   hep-phhep-exnucl-exPRD(2022)·3 citations
3. 03*

   Exploring Contur beyond its default mode: a case study

   M. M. Altakach🇵🇱 · J. M. Butterworth🇬🇧 · T. Ježo🇩🇪 · M. Klasen🇩🇪 · I. Schienbein🇫🇷

   We discuss Contur's different modes by studying a leptophobic Top-Colour (TC) model. We use, for the first time, higher order calculations for both the signal (NLO) and the background (up to NNLO). We compare the results between the different approaches of Contur. Furthermore, we compare these results to the ones coming from a direct search.

   hep-ph2 citations
4. 04*

   Microscopic and Macroscopic Effects in the Decoherence of Neutrino Oscillations

   Ting Cheng🇩🇪 · Manfred Lindner🇩🇪 · Werner Rodejohann🇩🇪

   We present a generic structure (the layer structure) for decoherence effects in neutrino oscillations, which includes decoherence from quantum mechanical and classical uncertainties. The calculation is done by combining the concept of open quantum system and quantum field theory, forming a structure composed of phase spaces from microscopic to macroscopic level. Having information loss at different levels, quantum mechanical uncertainties parameterize decoherence by an intrinsic mass eigenstate separation effect, while decoherence for classical uncertainties is typically dominated by a statistical averaging effect. With the help of the layer structure, we classify the former as state decoherence (SD) and the latter as phase decoherence (PD), then further conclude that both SD and PD result from phase wash-out effects of different phase structures on different layers. Such effects admit for simple numerical calculations of decoherence for a given width and shape of uncertainties. While our structure is generic, so are the uncertainties, nonetheless, a few notable ones are: the wavepacket size of the external particles, the effective interaction volume at production and detection, the energy reconstruction model and the neutrino production profile. Furthermore, we estimate the experimental sensitivities for SD and PD parameterized by the uncertainty parameters, for reactor neutrinos and decay-at-rest neutrinos, using a traditional rate measuring method and a novel phase measuring method.

   hep-phhep-exquant-phJHEP(2022)·15 citations
5. 05*

   The heavy tetra-quark states after the discovery of tetra-charm states

   Carlo Becchi🇮🇹

   This paper is devoted to the study of exclusive charm and bottom aggregates which are suitable, at least partially, for a non-relativistic description. Starting from a simple choice of quarkonia and tetra-quark wave functions we study their production cross sections, total widths and more interesting decay properties. In particular, we compute the production cross sections of the ground state scalar quarkonia getting results compatible with the values appearing in the literature. We also compute the production cross sections of the lower energy states of the charm and bottom tetra-quarks, their decay widths and the decay rates in two $\mu \bar{\mu }$ pairs and in the $q\bar{q}\mu \bar{\mu }$ channel. Our results on the tetra-charm are consistent with the data published by the LHCb Collaboration and those on the tetra-bottom show a reasonable agreement with the indications published by the CMS Collaboration. Our cross section analyses are based on interpolations based on the gluon-gluon luminosity grids published by the NNPDF and CTEQ Collaborations. The hard amplitude calculations are based on QCD in the tree approximation. We think that a careful improvement of our method and a refinement of the experimental data after the foreseen luminosity increase at the LHC will make possible valuable tests of QCD at the intermediate energies.

   hep-phEPJC(2022)·1 citation
6. 06*

   Decomposition of Triple Collinear Splitting Functions

   Oscar Braun-White🇬🇧 · Nigel Glover🇬🇧

   In the kinematic region where three particles $i$, $j$, $k$ are collinear, the multi-parton scattering amplitudes factorise into a product of a triple collinear splitting function and a multi-parton scattering amplitude with two fewer particles. These triple collinear splitting functions contain both iterated single unresolved contributions, and genuine double unresolved contributions. We make this explicit by rewriting the known triple collinear splitting functions in terms of products of two-particle splitting functions, and a remainder that is explicitly finite when any two of $\{i,j,k\}$ are collinear. We analyse all of the single unresolved singularities present in the remainder.

   hep-phJHEP(2022)·19 citations
7. 07*

   Masses of Heavy Flavour Mesons in a potential Model Approach with Wave Function containing Airy's Infinite Series

   Abdul Aziz🇮🇳 · Sabyasachi Roy🇮🇳 · Atri Deshamukhya🇮🇳

   We report the masses of $B$ and $D$ sectors heavy-flavoured mesons obtained by using our recently developed meson wave function employing potential model approach with linear confinement term in potential as parent in the perturbation method. As the wave-function involves infinite Airy's polynomial series, in carrying out the mass calculation, to avoid divergences, we have introduced some cut-off parameter for inter-quark separation. Our results for ground state masses of heavy-flavoured $B$ and $D$ sector mesons are reasonably closer to the PDG masses.

   hep-ph0 citations
8. 08*

   Chirality distributions inside baryons in $\mathrm{QC}{\mathrm{D}}_2$

   Adrien Florio🇺🇸 · David Frenklakh🇺🇸 · Dmitri E. Kharzeev🇺🇸

   The connection between the spin distribution and the topological structure of the baryon is an open and important problem. Here we address it using QCD in $(1+1)$ spacetime dimensions, which is exactly solvable at large number of colors $N$. It is found that the distribution of chirality inside a baryon is drastically different from a chirality distribution inside states with zero baryon number, ``mesons". This difference is shown to arise from the topological structure of the baryon -- at large $N$, all of the baryon's chirality is concentrated near $x=0$, whereas in a meson state it vanishes in the small $x$ limit. Our results illustrate how the constituent features of the baryon reemerge and are tied to the topological features of the bosonized solitonic solution. Possible implications for QCD in $(3+1)$ dimensions and for deep inelastic scattering experiments are discussed.

   hep-phhep-thnucl-thPRD(2022)·3 citations
9. 09*

   Transient phenomena in the axion assisted Schwinger effect

   Valerie Domcke🇨🇭 · Yohei Ema🇺🇸 · Kyohei Mukaida🇯🇵

   Particle production induced by a time-dependent background is well understood as the projection of the time-evolved initial state onto a set of final states. While the asymptotic initial and final states are well defined in the usual way, the definition of particles and antiparticles at intermediate times in the presence of external fields is ambiguous. These external fields moreover induce divergences which require regularization. In this paper we clarify some subtleties in the computation of transient effects in physical quantities for fermions in a homogeneous axion background, including Schwinger production in background electromagnetic fields. The presence of the axion requires particular care as well as knowledge of the UV theory when regulating the theory and computing the vacuum contribution to the fermion energy.

   hep-phhep-thJHEP(2022)·7 citations
10. 10*

    Unraveling the $0\nu \beta \beta$ Decay Mechanisms

    Lukáš Gráf🇺🇸 · Manfred Lindner🇩🇪 · Oliver Scholer🇩🇪

    We discuss the possibilities of distinguishing among different mechanisms of neutrinoless double beta decay arising in the effective field theory framework. Following the review and detailed investigation of the particular ways of discrimination, we conclude that the 32 different low-energy effective operators can be split into multiple groups that are in principle distinguishable from each other by measurements of the phase-space observables and by comparison of the decay rates obtained using different isotopes. This would require not only a substantial experimental precision but necessarily also a considerable improvement of the current theoretical knowledge of the underlying nuclear physics. Specifically, the limiting aspect in our approach turns out to be the currently unknown or uncertain values of low-energy constants. Besides the study adopting the effective field theory language we also look into several typical UV models.

    hep-phhep-exPRD(2022)·53 citations
11. 11*

    D-term inflation in braneworld models: Consistency with cosmic-string bounds and early-time Hubble tension resolving models

    Chia-Min Lin🇹🇼

    We revisit D-term inflation with the bounds of the cosmic string tension from gravitational wave observations and consider the possible deviation of the spectral index compared with the $\Lambda$CDM model in light of prerecombination resolutions of the Hubble tension. D-term inflation requires very small coupling constants under these constraints. We show that natural coupling constants ($g=\lambda =0.1$) can be achieved in the case of D-term inflation on the brane.

    ↳ hep-thastro-ph.COhep-phPRD(2022)·17 citations
12. 12*

    Extraction of different temperatures and kinetic freeze-out volume in high energy collisions

    M. Waqas🇨🇳 · G.-X. Peng🇨🇳 · M. Ajaz🇵🇰 · A. Haj Ismail🇦🇪 · Z. Wazir🇵🇰 · L.-L. Li🇨🇳

    We analyze the transverse momentum ($p_T$) spectra, $1/N_{ev}$[(1/2$\pi$$p_T$) $d^2$$N$/$dyd$$p_T$], of kaon, proton, deuteron and triton in different centrality events in gold-gold (Au-Au) collisions at Relativistic Heavy Ion Collisions (RHIC) by Hagedorn thermal model and extracted the excitation function of effective temperature, kinetic freeze-out volume, initial temperature and kinetic freeze-out temperature. We perceived that the effective temperature, initial temperature and kinetic freeze-out temperature sharply increases from 7.7 GeV to 14.5 GeV and then remain static from 14.5-39 GeV, and this consistency may disclose that the onset energy of the phase transition of partial deconfinement and the whole deconfinement are 14.5 and 39 GeV respectively. The kinetic freeze-out volume and mean transverse momentum grows with the rise of collision energy. Furthermore, the different extracted temperatures are observed in the order of time evolution of the interacting system, and they (as well as kinetic freeze-out volume) have an increasing trend from peripheral to central collisions. We also observed the mass dependence of the effective temperature and kinetic freeze-out volume where former increases while the later decreases for heavier particles, which indicates the early freeze-out of the heavier particles.

    ↳ nucl-thhep-phJ.Phys.G(2022)·21 citations
13. 13*

    Dimensional regularization, Wilsonian RG, and the Naturalness/Hierarchy problem

    Carlo Branchina🇫🇷 · Vincenzo Branchina🇮🇹 · Filippo Contino🇮🇹 · Neda Darvishi🇺🇸

    While it is usually stated that dimensional regularization (DR) has no direct physical interpretation, consensus has recently grown on the idea that it might be endowed with special physical properties that would provide the mechanism that solves the naturalness/hierarchy problem. Comparing direct Wilsonian calculations with the corresponding DR ones, we find that DR indeed has a well-defined physical meaning, and we point out its limitations. In particular, our results show that DR cannot provide the solution to the naturalness/hierarchy problem. The absence of too large corrections to the Higgs boson mass is due to a secretly realized fine-tuning, rather than special physical properties of DR. We also investigate these issues within the Wilsonian RG framework and, by comparison with the usual perturbative RG analysis, we show that several popular proposals for the resolution of the problem, commonly considered as physical mechanisms free of fine-tuning, again secretly implement the tuning.

    ↳ hep-thcond-mat.stat-mechhep-phPRD(2022)·34 citations
14. 14*

    The problem with Proca: ghost instabilities in self-interacting vector fields

    Katy Clough🇬🇧 · Thomas Helfer🇺🇸 · Helvi Witek🇺🇸 · Emanuele Berti🇺🇸

    Massive vector fields feature in several areas of particle physics, e.g., as carriers of weak interactions, dark matter candidates, or as an effective description of photons in a plasma. Here we investigate vector fields with self-interactions by replacing the mass term in the Proca equation with a general potential. We show that this seemingly benign modification inevitably introduces ghost instabilities of the same kind as those recently identified for vector-tensor theories of modified gravity (but in this simpler, minimally coupled theory). It has been suggested that nonperturbative dynamics may drive systems away from such instabilities. We demonstrate that this is not the case by evolving a self-interacting Proca field on a Kerr background, where it grows due to the superradiant instability. The system initially evolves as in the massive case, but instabilities are triggered in a finite time once the self-interaction becomes significant. These instabilities have implications for the formation of condensates of massive, self-interacting vector bosons, the possibility of spin-one bosenovae, vector dark matter models, and effective models for interacting photons in a plasma.

    ↳ gr-qcastro-ph.HEhep-phPRL(2022)·72 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.