arXiv subjects

Yu Seon Jeong

Publications and source records attributed to Yu Seon Jeong.

31 records · Page 2Linked to original sources

arXiv2018

Probing secret interactions of eV-scale sterile neutrinos with the diffuse supernova neutrino background

Sterile neutrinos with mass in the eV-scale and large mixings of order $θ_0\simeq 0.1$ could explain some anomalies found in short-baseline neutrino oscillation data. Here, we revisit a neutrino portal scenario in which eV-scale sterile neutrinos have self-interactions via a new gauge vector boson $ϕ$. Their production in the early Universe via mixing with active neutrinos can be suppressed by the induced effective potential in the sterile sector. We study how different cosmological observations can constrain this model, in terms of the mass of the new gauge boson, $M_ϕ$, and its coupling to sterile neutrinos, $g_s$. Then, we explore how to probe part of the allowed parameter space of this particular model with future observations of the diffuse supernova neutrino background by the Hyper-Kamiokande and DUNE detectors. For $M_ϕ\sim 5-10$~keV and $g_s \sim 10^{-4}-10^{-2}$, as allowed by cosmological constraints, we find that interactions of diffuse supernova neutrinos with relic sterile neutrinos on their way to the Earth would result in significant dips in the neutrino spectrum which would produce unique features in the event spectra observed in these detectors.

hep-ph↗

arXiv2017

Tau energy loss and ultrahigh energy skimming tau neutrinos

We consider propagation of high energy earth-skimming taus produced in interactions of astrophysical tau neutrinos. For astrophysical tau neutrinos we take generic power-law flux, $E^{-2}$ and the cosmogenic flux initiated by the protons. We calculate tau energy loss in several approaches, such as dipole models and the phenomenological approach in which parameterization of the $F_2$ is used. We evaluate the tau neutrino charged-current cross section using the same approaches for consistency. We find that uncertainty in the neutrino cross section and in the tau energy loss partially compensate giving very small theoretical uncertainty in the emerging tau flux for distances ranging from $2$ km to $100$ km and for the energy range between $10^6$ GeV and $10^{11}$ GeV, focusing on energies above $10^8$ GeV. When we consider uncertainties in the neutrino cross section, inelasticity in neutrino interactions and the tau energy loss, which are not correlated, i.e. they are not all calculated in the same approach, theoretical uncertainty ranges from about $30\%$ and $60 \%$ at $10^8$ GeV to about factors of 3.3 and 3.8 at $10^{11}$ GeV for the $E^{-2}$ flux and the cosmogenic flux, respectively, for the distance of 10 km rock. The spread in predictions significantly increases for much larger distances, e.g., $\sim 1,000$ km. Most of the uncertainty comes from the treatment of photonuclear interactions of the tau in transit through large distances. We also consider Monte Carlo calculation of the tau propagation and we find that the result for the emerging tau flux is in agreement with the result obtained using analytic approach. Our results are relevant to several experiments that are looking for skimming astrophysical taus, such as the Pierre Auger Observatory, HAWC and Ashra. We evaluate the aperture for the Auger and discuss briefly application to the the other two experiments.

hep-ph↗

arXiv2016

Prompt atmospheric neutrino flux from the various QCD models

We evaluate the prompt atmospheric neutrino flux using the different QCD models for heavy quark production including the $b$ quark contribution. We include the nuclear correction and find it reduces the fluxes by $10 \% - 50\%$ according to the models. Our heavy quark results are compared with experimental data from RHIC, LHC and LHCb.

hep-ph↗

arXiv2016

Prompt atmospheric neutrino flux

We evaluate the prompt atmospheric neutrino flux including nuclear correction and $B$ hadron contribution in the different frameworks: NLO perturbative QCD and dipole models. The nuclear effect is larger in the prompt neutrino flux than in the total charm production cross section, and it reduces the fluxes by $10\% - 30\%$ depending on the model. We also investigate the uncertainty using the QCD scales allowed by the charm cross section data from RHIC and LHC experiments.

hep-ph↗

arXiv2016

Prompt atmospheric neutrino fluxes: perturbative QCD models and nuclear effects

We evaluate the prompt atmospheric neutrino flux at high energies using three different frameworks for calculating the heavy quark production cross section in QCD: NLO perturbative QCD, $k_T$ factorization including low-$x$ resummation, and the dipole model including parton saturation. We use QCD parameters, the value for the charm quark mass and the range for the factorization and renormalization scales that provide the best description of the total charm cross section measured at fixed target experiments, at RHIC and at LHC. Using these parameters we calculate differential cross sections for charm and bottom production and compare with the latest data on forward charm meson production from LHCb at $7$ TeV and at $13$ TeV, finding good agreement with the data. In addition, we investigate the role of nuclear shadowing by including nuclear parton distribution functions (PDF) for the target air nucleus using two different nuclear PDF schemes. Depending on the scheme used, we find the reduction of the flux due to nuclear effects varies from $10\%$ to $50 \%$ at the highest energies. Finally, we compare our results with the IceCube limit on the prompt neutrino flux, which is already providing valuable information about some of the QCD models.

hep-ph↗

arXiv2016

Constraints on the $U(1)_L$ gauge boson in a wide mass range

There is a growing interest for the search of new light gauge bosons. The small mass of a new boson can turn various kinds of low-energy experiments to a new discovery machine, depending on their couplings to the standard model particles. It is important to understand the properties of each type of gauge boson and their current constraints for a given mass. While the dark photon (which couples to the electric charges) and the $U(1)_{B-L}$ gauge boson have been well studied in an extensive mass range, the $U(1)_L$ gauge boson has not been fully investigated yet. We consider the gauge boson of the $U(1)_L$ in a wide mass range $m_{Z'} \approx 0 - 10^{12} ~\ev$ and investigate the constraints on its coupling from various experiments, discussing the similarities and differences from the dark photon and the $U(1)_{B-L}$ gauge boson.

hep-ph↗

arXiv2015

A facility to Search for Hidden Particles at the CERN SPS: the SHiP physics case

This paper describes the physics case for a new fixed target facility at CERN SPS. The SHiP (Search for Hidden Particles) experiment is intended to hunt for new physics in the largely unexplored domain of very weakly interacting particles with masses below the Fermi scale, inaccessible to the LHC experiments, and to study tau neutrino physics. The same proton beam setup can be used later to look for decays of tau-leptons with lepton flavour number non-conservation, $τ\to 3μ$ and to search for weakly-interacting sub-GeV dark matter candidates. We discuss the evidence for physics beyond the Standard Model and describe interactions between new particles and four different portals - scalars, vectors, fermions or axion-like particles. We discuss motivations for different models, manifesting themselves via these interactions, and how they can be probed with the SHiP experiment and present several case studies. The prospects to search for relatively light SUSY and composite particles at SHiP are also discussed. We demonstrate that the SHiP experiment has a unique potential to discover new physics and can directly probe a number of solutions of beyond the Standard Model puzzles, such as neutrino masses, baryon asymmetry of the Universe, dark matter, and inflation

hep-ph↗

arXiv2014

Color dipole cross section and inelastic structure function

Instead of starting from a theoretically motivated form of the color dipole cross section in the dipole picture of deep inelastic scattering, we start with a parametrization of the deep inelastic structure function for electromagnetic scattering with protons, and then extract the color dipole cross section. Using the parametrizations of $F_2(ξ=x \ {\rm or}\ W^2,Q^2)$ by Donnachie-Landshoff and Block et al., we find the dipole cross section from an approximate form of the presumed dipole cross section convoluted with the perturbative photon wave function for virtual photon splitting into a color dipole with massless quarks. The color dipole cross section determined this way reproduces the original structure function within about 10\% for $0.1$ GeV$^2\leq Q^2\leq 10$ GeV$^2$. We discuss the large and small form of the dipole cross section and compare with other parameterizations.

hep-ph↗

arXiv2013

Charge Asymmetry of Weak Boson Production at the LHC and the Charm Content of the Proton

We investigate the production of the weak bosons $W^+$, $W^-$ and $Z$ at the LHC as a function of their rapidity, reconstructed {\it experimentally} from their leptonic decay. We show that the measurements provide a powerful tool for constraining the parton distribution functions, as was already the case for the lower energy $p\bar{p}$ collider data. We study the charge asymmetry determining the $u$ and $d$ distribution functions using the reconstructed $W^+$, $W^-$ rapidities. We also show how the ratio of the $W$ and $Z$ boson rapidity distributions directly probes the charm quark distribution function of the proton.

hep-ph↗

arXiv2012

Majorana Dark Matter Cross Sections with Nucleons at High Energies

Non-relativistic dark matter scattering with nucleons is constrained by direct detection experiments. We use the XENON constraints on the spin-independent and spin-dependent cross section for dark matter scattering with nucleons to constrain a hypothetical Majorana fermionic dark matter particle's couplings to the Higgs boson and Z boson. In the procedure we illustrate the change in the dark matter nucleon cross section as one goes from non-relativistic, coherent scattering to relativistic, incoherent scattering. While the Z invisible decay width excludes directly couplings of dark matter to ordinary matter, by introducing a light Z' portal to the dark sector, a relatively large dark matter nucleon cross section can be preserved even with accelerator experiment constraints for dark matter with a mass of ~10 GeV

hep-ph↗

arXiv2011

Radio Cherenkov signals from the Moon: neutrinos and cosmic rays

Neutrino production of radio Cherenkov signals in the Moon is the object of radio telescope observations. Depending on the energy range and detection parameters, the dominant contribution to the neutrino signal may come from interactions of the neutrino on the Moon facing the telescope, rather than neutrinos that have traversed a portion of the Moon. Using the approximate analytic expression of the effective lunar aperture from a recent paper by Gayley, Mutel and Jaeger, we evaluate the background from cosmic ray interactions in the lunar regolith. We also consider the modifications to the effective lunar aperture from generic non-standard model neutrino interactions. A background to neutrino signals are radio Cherenkov signals from cosmic ray interactions. For cosmogenic neutrino fluxes, neutrino signals will be difficult to observe because of low neutrino flux at the high energy end and large cosmic ray background in the lower energy range considered here. We show that lunar radio detection of neutrino interactions is best suited to constrain or measure neutrinos from astrophysical sources and probe non-standard neutrino-nucleon interactions such as microscopic black hole production.

astro-ph.CO↗

arXiv2010

Tau neutrino and antineutrino cross sections

Tau neutrino and antineutrino interactions with nucleons in large underground or under ice detectors will be important signals of astrophysical and atmospheric sources of neutrinos. We present here a theoretical update of the deep inelastic scattering contribution to the tau neutrino and antineutrino charged current cross sections with isoscalar nucleon targets and proton targets for incident neutrinos and antineutrinos in the energy range from 10 GeV to 10 TeV. Next-to-leading order quantum chromodynamic corrections, target mass corrections and heavy quark effects are included. Uncertainties in the cross section associated with the structure functions a low momentum transfers, the input parton distribution functions, scale dependence and flavor number scheme are discussed.

hep-ph↗

arXiv2010

Quark mass effects in high energy neutrino nucleon scattering

We evaluate the neutrino nucleon charged current cross section at next-to-leading order in quantum chromodynamic corrections in the variable flavor number scheme and the fixed flavor number scheme, taking into account quark masses. The number scheme dependence is largest at the highest energies considered here, $10^{12}$ GeV, where the cross sections differ by approximately 15 percent. We illustrate the numerical implications of the inconsistent application of the fixed flavor number scheme.

hep-ph↗