HEP Phenomenology·hep-ph

Wed·Jan 6, 2021Wednesday·January 6, 2021

17 papers—13 primary·4 cross-listed·reconstructed*

01*
Fast Flavor Oscillations of Astrophysical Neutrinos with $1, 2, \dots, \infty$ Crossings
Soumya Bhattacharyya🇮🇳 · Basudeb Dasgupta🇮🇳
In the early Universe, as well as in supernovae and merging neutron stars, neutrinos have such high densities that they affect each other and exhibit collective flavor oscillations. A crucial ingredient for fast collective flavor oscillations is that the electron lepton number (ELN) distribution changes its sign as a function of direction, i.e., has a zero crossing. We present a study in two dimensions and show how fast flavor oscillations depend on the ELN and its crossings. We show that a large number of crossings can inhibit flavor oscillations. This may be a natural self-limiting mechanism that stabilizes the flavor content of the dense neutrino gas in a vast majority of scenarios, especially the early Universe, where the angular distributions for all flavors are very similar and crossings occur mainly due to fluctuations.
hep-phastro-ph.COastro-ph.SRJCAP(2021)·17 citations
02*
Fast flavor oscillations in dense neutrino media with collisions
Joshua D. Martin🇺🇸 · J. Carlson🇺🇸 · Vincenzo Cirigliano🇺🇸 · Huaiyu Duan🇺🇸
We investigate the impact of the nonzero neutrino splitting and elastic neutrino-nucleon collisions on fast neutrino oscillations. Our calculations confirm that a small neutrino mass splitting and the neutrino mass hierarchy have very little effect on fast oscillation waves. We also demonstrate explicitly that fast oscillations remain largely unaffected for the time/distance scales that are much smaller than the neutrino mean free path but are damped on larger scales. This damping originates from both the direct modification of the dispersion relation of the oscillation waves in the neutrino medium and the flattening of the neutrino angular distributions over time. Our work suggests that fast neutrino oscillation waves produced near the neutrino sphere can propagate essentially unimpeded which may have ramifications in various aspects of the supernova physics.
hep-phastro-ph.HEnucl-thPRD(2021)·80 citations
03*
Updates to the One-loop Provider NLOX
Diogenes Figueroa🇺🇸 · Seth Quackenbush🇺🇸 · Laura Reina🇺🇸 · Christian Reuschle🇸🇪
We describe the 1.2 update to NLOX, a computer program for calculations in high-energy particle physics. New features since the 1.0 release and other changes are described, along with usage documentation.
hep-phComput.Phys.Commun.(2022)·13 citations
04*
Study on pure annihilation type B to V gamma decays
Hui Deng🇨🇳 · Jing Gao🇨🇳 · Lei-Yi Li🇨🇳 · Cai-Dian Lü🇨🇳 · Yue-Long Shen🇨🇳 · Chun-Xu Yu🇨🇳
We investigate the pure annihilation type radiative $B$ meson decays $B^{0} \to ϕ γ$ and $B_{s} \to ρ^{0} (ω) γ$ in the soft-collinear effective theory. We consider three types of contributions to the decay amplitudes, including the direct annihilation topology, the contribution from the electro-magnetic penguin operator and the contribution of the neutral vector meson mixings. The numerical analysis shows that the decay amplitudes are dominated by the $ω - ϕ$ mixing effect in the $B^{0} \to ϕ γ$ and $B_{s} \to ω γ$ modes. The corresponding decay branching ratios are enhanced about three orders of magnitudes relative to the pure annihilation type contribution in these two decay channels. The decay rate of $B_{s} \to ρ^{0} γ$ is much smaller than that of $B_{s} \to ω γ$ because of the smaller $ρ^{0} - ϕ$ mixing. The predicted branching ratios $B (B^{0} \to ϕ γ) = (3.9 9_{- 1.46}^{+ 1.67}) \times 1 0^{- 9}, B (B_{s} \to ω γ) = (2.0 1_{- 0.71}^{+ 0.81}) \times 1 0^{- 7}$ are to be tested by the Belle-II and LHC-b experiments.
hep-phPRD(2021)·9 citations
05*
Compositeness, Bargmann-Wigner solutions within a U(1)-interaction quantum-field-theory expansion, and charge
J. Besprosvany🇲🇽
New solutions of the Bargmann-Wigner equations are obtained: free fermion-antifermion pairs, each satisfying Dirac's equation, with parallel momenta and momenta on a plane, produce vectors satisfying Proca's equations. These equations are consistent with Dirac's and Maxwell's equations, as zero-order conditions within a Lagrangian expansion for the U(1)-symmetry quantum field theory. Such vector solutions' demand that they satisfy Maxwell's equations and quantization fix the charge. The current equates the vector field, reproducing the superconductivity London equations, thus, binding and screening conditions. The derived vertex connects to QCD superconductivity and constrains four-fermion interaction composite models.
hep-phhep-th0 citations
06*
$Δ B = 2$ neutron decay into antiproton mode $n \to p ˉ e^{+} ν (ν ˉ)$
Xiao-Gang He🇹🇼 · Xiao-Dong Ma🇹🇼
We discuss the unique baryon number violation by two units neutron decay mode $n \to p ˉ e^{+} χ$ , with $χ$ being the standard model (SM) neutrino $ν$ or antineutrino $ν ˉ$ or any beyond SM light fermion, in the framework of effective field theory. This mode is kinematically allowed but rarely discussed theoretically or searched for experimentally. We estimate the lower bound on its partial lifetime from that of the dinucleon decay $n p \to e^{+} χ$ per oxygen nucleus $^{16}$ O set by the Super-Kamiokande experiment, with a conservative bound $Γ_{n \to p ˉ e^{+} χ}^{- 1} > 5.7 \times 1 0^{39} yrs$ . We also discuss its characteristic signature for the future experimental search and astrophysical implications.
hep-phPLB(2021)·15 citations
07*
Triply Charged Monopole and Magnetic Quarks
George Lazarides🇬🇷 · Qaisar Shafi🇺🇸
We describe the internal composition of a topologically stable monopole carrying a magnetic charge of $6 π / e$ that arises from the spontaneous breaking of the trinification symmetry $S U (3)_{c} \times S U (3)_{L} \times S U (3)_{R}$ ( $G$ ). Since this monopole carries no color magnetic charge, a charge of $6 π / e$ is required by the Dirac quantization condition. The breaking of $G$ to the Standard Model occurs in a number of steps and yields the desired topologically stable monopole ("magnetic baryon"), consisting of three confined monopoles. The confined monopoles ("magnetic quarks") each carry a combination of Coulomb magnetic flux and magnetic flux tubes, and therefore they do not exist as isolated states. We also display a more elaborate configuration ("fang necklace") composed of these magnetic quarks. In contrast to the $S U (5)$ monopole which is superheavy and carries a magnetic charge of $2 π / e$ as well as color magnetic charge, the trinification monopole may have mass in the TeV range, in which case it may be accessible at the LHC and its planned upgrades.
hep-phhep-thPLB(2021)·18 citations
08*
Three-loop off-forward evolution kernel for axial-vector operators in Larin's scheme
V. M. Braun🇩🇪 · A. N. Manashov🇩🇪 · S. Moch🇩🇪 · M. Strohmaier🇩🇪
Evolution equations for leading twist operators in high orders of perturbation theory can be restored from the spectrum of anomalous dimensions and the calculation of the special conformal anomaly at one order less using conformal symmetry of QCD at the Wilson-Fisher critical point at non-integer $d = 4 - 2 ϵ$ space-time dimensions. In this work we generalize this technique to axial-vector operators. We calculate the corresponding three-loop evolution kernels in Larin's scheme and derive explicit expressions for the finite renormalization kernel that describes the difference to the vector case to restore the conventional $MS$ -scheme. The results are directly applicable to deeply-virtual Compton scattering and the transition form factor $γ^{*} γ \to π$ .
hep-phPRD(2021)·12 citations
09*
One-loop corrections to the processes $e^{+} e^{-} \to γ, Z \to J / ψ η_{c}$ and $e^{+} e^{-} \to Z \to J / ψ J / ψ$
A.V. Berezhnoy🇷🇺 · I.N. Belov🇷🇺 · S.V. Poslavsky🇷🇺 · A.K. Likhoded🇷🇺
The cross section values of $J / ψ η_{c}$ and $J / ψ J / ψ$ production in $e^{+} e^{-}$ annihilation are estimated within one-loop approximation near $Z$ pole, as well as at higher energies. Both intermediate bosons, $γ$ and $Z$ , are taken into account. It is shown that at $Z$ mass the NLO contribution increases the cross-section values by 3.5 times.
hep-phPRD(2021)·13 citations
10*
Fragmentation functions for a quark into a spin-singlet quarkonium: Different flavor case
Xu-Chang Zheng🇨🇳 · Ze-Yang Zhang🇨🇳 · Xing-Gang Wu🇨🇳
In the paper, we calculate the fragmentation functions for a quark to fragment into a spin-singlet quarkonium, where the flavor of the initial quark is different from that of the constituent quark in the quarkonium. The ultraviolet divergences in the phase space integral are removed through the operator renormalization under the modified minimal subtraction scheme. The fragmentation function $D_{q \to η_{Q}} (z, μ_{F})$ is expressed as a two-dimensional integral. Numerical results for the fragmentation functions of a light quark or a bottom quark to fragment into the $η_{c}$ are presented. As an application of those fragmentation functions, we study the processes $Z \to η_{c} + q q ˉ g (q = u, d, s)$ and $Z \to η_{c} + b b ˉ g$ under the fragmentation and the direct nonrelativistic QCD approaches.
hep-phPRD(2021)·15 citations
11*
Bose-Einstein condensation of pions in proton-proton collisions at the Large Hadron Collider using non-extensive Tsallis statistics
Suman Deb🇮🇳 · Dushmanta Sahu🇮🇳 · Raghunath Sahoo🇮🇳 · Anil Kumar Pradhan🇮🇳
The possibility of formation of Bose-Einstein Condensation (BEC) is studied in $pp$ collisions at $s$ = 7 TeV at the Large Hadron Collider. A thermodynamically consistent non-extensive formulation of the identified hadron transverse momentum distributions is used to estimate the critical temperature required to form BEC of charged pions, which are the most abundant species in a multi-particle production process in hadronic and nuclear collisions. The obtained results have been contrasted with the systems produced in Pb-Pb collisions to have a better understanding. We observe an explicit dependency of BEC critical temperature and number of particles in the pion condensates on the non-extensive parameter $q$ , which is a measure of degree of non-equilibrium -- as $q$ decreases, the critical temperature increases and approaches to the critical temperature obtained from Bose-Einstein statistics without non-extensivity. Studies are performed on the final state multiplicity dependence of number of particles in the pion condensates in a wide range of multiplicity covering hadronic and heavy-ion collisions, using the inputs from experimental transverse momentum spectra.
hep-phhep-exnucl-exnucl-thEPJA(2021)·12 citations
12*
Fast Neutrino Flavor Conversion at Late Time
Soumya Bhattacharyya🇮🇳
We all know that in the dense anisotropic interior of the star, neutrino-neutrino forward-scattering can lead to fast collective neutrino oscillations, which has striking consequences on flavor dependent neutrino emission and can be crucial for the evolution of a supernova and its neutrino signal. The flavor evolution of such dense neutrino system is governed by a large number of coupled nonlinear partial differential equations which are almost always very difficult to solve. Although the triggering, initial linear growth and the condition for fast oscillations to occur are understood by "Linear stability analysis" but this fails to answer an important question: "what is the impact of fast flavor conversion on observable neutrino fluxes or the supernova explosion mechanism?". This is a significantly harder problem that requires understanding the nature of the final state solution in the nonlinear regime. Moving towards this direction we present one of the first numerical as well as an analytical study of the coupled flavor evolution of a non-stationary and inhomogeneous dense neutrino system in the nonlinear regime considering one spatial dimension and a spectrum of velocity modes. This work gives a clear picture of the final state flavor dynamics of such systems specifying its dependence on space-time coordinates, phase space variables as well as the lepton asymmetry and thus can have significant implications for the supernova astrophysics as well as its associated neutrino phenomenology even for the most realistic scenario.
hep-phastro-ph.HEPoS(2021)·0 citations
13*
Telescope Array Bursts, Radio Pulses and Axion Quark Nuggets
Xunyu Liang🇨🇦 · Ariel Zhitnitsky🇨🇦
Telescope Array (TA) experiment has recorded \cite{Abbasi:2017rvx,Okuda_2019} several short time bursts of air shower like events. These bursts are very distinct from conventional single showers, and are found to be strongly correlated with lightnings. In our previous work \cite{Zhitnitsky:2020shd} we proposed that these bursts represent the direct manifestation of the dark matter (DM) annihilation events within the so-called axion quark nugget (AQN) model. In the present work we suggest to test this proposal to search for the radio signals in frequency band $ν \in (0.5 - 200)$ MHz which must be synchronized with the TA bursts. We argued that the conventional lightning-induced radio emission can be easily discriminated from the AQN-induced radio pulses discussed in this work.
hep-phastro-ph.HEastro-ph.IMphysics.ao-phEPJC(2022)·12 citations
14*
Test of the superdiffusion model in the interstellar medium around the Geminga pulsar
Sheng-Hao Wang🇨🇳 · Kun Fang🇨🇳 · Xiao-Jun Bi🇨🇳 · Peng-Fei Yin🇨🇳
The TeV $γ$ -ray halo around the Geminga pulsar is an important indicator of cosmic-ray (CR) propagation in the local zone of the Galaxy as it reveals the spatial distribution of the electrons and positrons escaping from the pulsar. Considering the intricate magnetic field in the interstellar medium (ISM), it is proposed that superdiffusion model could be more realistic to describe the CR propagation than the commonly used normal diffusion model. In this work, we test the superdiffusion model in the ISM around the Geminga pulsar by fitting to the surface brightness profile of the Geminga halo measured by HAWC. Our results show that the chi-square statistic monotonously increases as $α$ decreases from 2 to 1, where $α$ is the characteristic index of superdiffusion describing the degree of fractality of the ISM and $α = 2$ corresponds to the normal diffusion model. We find that model with $α < 1.32$ (or $< 1.4$ , depending on the data used in fit) is disfavored at 95\% confidence level. Superdiffusion model with $α$ close to 2 can well explain the morphology of the Geminga halo, while it predicts much higher positron flux on the Earth than the normal diffusion model. This has important implication for the interpretation of the CR positron excess.
↳ astro-ph.HEhep-phPRD(2021)·13 citations
15*
Ideal topological gas in the high temperature phase of SU(3) gauge theory
Reka A. Vig (Debrecen U.)🇭🇺 · Tamas G. Kovacs (Eotvos Lorand U., Budapest, Inst. Theor. Phys. and Debrecen, Inst. Nucl. Res.)🇭🇺
We show that the nature of the topological fluctuations in $S U (3)$ gauge theory changes drastically at the finite temperature phase transition. Starting from temperatures right above the phase transition topological fluctuations come in well separated lumps of unit charge that form a non-interacting ideal gas. Our analysis is based on a novel method to count not only the net topological charge, but also separately the number of positively and negatively charged lumps in lattice configurations using the spectrum of the overlap Dirac operator. This enables us to determine the joint distribution of the number of positively and negatively charged topological objects, and we find this distribution to be consistent with that of an ideal gas of unit charged topological objects.
↳ hep-lathep-phhep-thPRD(2021)·32 citations
16*
Implications of current nuclear cross sections on secondary cosmic rays with the upcoming DRAGON2 code
Pedro de la Torre Luque🇮🇹 · Mario Nicola Mazziotta🇮🇹 · Francesco Loparco🇮🇹 · Fabio Gargano🇮🇹 · Davide Serini🇮🇹
Current measurements of cosmic-ray fluxes have reached unprecedented accuracy thanks to the new generation of experiments, and in particular the AMS-02 mission. At the same time, significant progress has been made in the propagation models of galactic cosmic rays. These models include several propagation parameters, which are usually inferred from the ratios of secondary to primary cosmic rays, and which depend on the cross sections describing the collisions among the various species of cosmic-ray nuclei. At present, our knowledge of these cross sections in the energy range where cosmic-ray interactions occur is limited, and this is a source of uncertainties in the predicted fluxes of secondary cosmic-ray nuclei. In this work we study the impact of the cross section uncertainties on the fluxes of light secondary nuclei (Li, Be, B) using a preliminary version of the upcoming {\tt DRAGON2} code. We first present a detailed comparison of the secondary fluxes computed by implementing different parametrizations for the network of spallation cross sections. Then, we propose for the first time the use of secondary-over-secondary cosmic-ray flux ratios as a tool to investigate the consistency of cross sections models and give insight of the overall uncertainties coming from the cross sections parametrizations. We show that the uncertainties inferred from the cross section data are enough to explain the discrepancies in the Be and Li fluxes with respect to the AMS-02 data, with no need of a primary component in their spectra. In addition, we show that the fluxes of B, Be and Li can be simultaneously reproduced by rescaling their cross sections within the experimental uncertainty. Finally, we also revisit the diffusive estimation of the halo size, obtaining good agreement with previous works and a best fit value of $6.8 \pm 1$ kpc from the most updated cross sections parametrizations.
↳ astro-ph.HEhep-exhep-phJCAP(2021)·53 citations
17*
Chiral Effective Field Theory and the High-Density Nuclear Equation of State
C. Drischler🇺🇸 · J.W. Holt🇺🇸 · C. Wellenhofer🇩🇪
Born in the aftermath of core collapse supernovae, neutron stars contain matter under extraordinary conditions of density and temperature that are difficult to reproduce in the laboratory. In recent years, neutron star observations have begun to yield novel insights into the nature of strongly interacting matter in the high-density regime where current theoretical models are challenged. At the same time, chiral effective field theory has developed into a powerful framework to study nuclear matter properties with quantified uncertainties in the moderate-density regime for modeling neutron stars. In this article, we review recent developments in chiral effective field theory and focus on many-body perturbation theory as a computationally efficient tool for calculating the properties of hot and dense nuclear matter. We also demonstrate how effective field theory enables statistically meaningful comparisons between nuclear theory predictions, nuclear experiments, and observational constraints on the nuclear equation of state.
↳ nucl-thastro-ph.HEastro-ph.SRhep-ph+1Ann.Rev.Nucl.Part.Sci.(2021)·249 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.