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Bing-Lin Young

Publications and source records attributed to Bing-Lin Young.

At least 19 recordsLinked to original sources
arXiv2016

Detection of supernova neutrinos at spallation neutron sources

After considering the supernova shock effects, the Mikheyev-Smirnov-Wolfenstein effects, the neutrino collective effects, and the Earth matter effects, the detection of supernova neutrinos at China Spallation Neutron Sources is studied and the event numbers of different flavor supernova neutrinos observed through various reaction channels are calculated with the neutrino energy spectra described by the Fermi-Dirac distribution and "beta fit" distribution respectively. Furthermore, the numerical calculation method of supernova neutrino detection on the Earth is applied to some other spallation neutron sources, and the total event numbers of supernova neutrinos observed through different reactions channels are given.

hep-ph↗
arXiv2014

Effects of Shock Waves on Neutrino Oscillations in Three Supernova Models

It has been realized that the shock wave effects play an important role in neutrino oscillations during the supernova explosion. In recent years, with the development of simulations about supernova explosion, we have a better understanding about the density profiles and the shock waves in supernovae than before. It has been shown that the appearance of shock waves not only varies with time, but is also affected by the mass of the supernova. When the mass of the supernova happens to be in a certain range (e.g. it equals 10.8 times the mass of the sun), there might be a reverse shock wave, another sudden change of density except the forward shock wave, emerging in the supernova. In addition, there are some other time-dependent changes of density profiles in different supernova models. Because of these complex density profiles, the expression of the crossing probability at the high resonance, $P_H$, which we used previously would be no longer applicable. In order to get more accurate and reasonable results, we use the data of density profiles in three different supernova models obtained from simulations to study the variations of $P_s$ (the survival probability of $ν_e\rightarrowν_e$), as well as $P_c$ (the conversion probability of $ν_x\rightarrowν_e$). It is found that the mass of the supernova does make a difference on the behavior of $P_s$, and affects $P_c$ at the same time. With the results of $P_s$ and $P_c$, we can estimate the number of $ν_e$ remained after they go through the matter in the supernova.

hep-ph↗
arXiv2013

Detection of supernova neutrinos on the Earth for large theta13

Supernova (SN) neutrinos detected on the Earth are subject to the shock wave effects, the Mikheyev-Smirnov-Wolfenstein (MSW) effects, the neutrino collective effects and the Earth matter effects. Considering the recent experimental result about the large mixing angle $θ_{13}$ ($\backsimeq8.8^{\circ}$) provided by the Daya Bay Collaboration and applying the available knowledge for the neutrino conversion probability in the high resonance of SN, $P_{H}$, which is in the form of hypergeometric function in the case of large $θ_{13}$, we deduce the expression of $P_{H}$ taking into account the shock wave effects. It is found that $P_{H}$ is not zero in a certain range of time due to the shock wave effects. After considering all the four physical effects and scanning relevant parameters, we calculate the event numbers of SN neutrinos detected at the Daya Bay experiment. From the numerical results, it is found that the behaviors of neutrino event numbers detected on the Earth depend on the neutrino mass hierarchy and neutrino spectrum parameters including the temperature $T_α$, the dimensionless pinching parameter $η_α$ or $β_α$ (where $α$ refers to neutrino flavor), the average energy $< E_α>$, and the SN neutrino luminosities $L_α$. We also compare the results of two parametrization methods for the neutrino energy distributions and give the ranges of SN neutrino event numbers that will be detected at the Daya Bay experiment.

hep-ph↗
arXiv2010

Acquire information about neutrino parameters by detecting supernova neutrinos

We consider the supernova shock effects, the Mikheyev-Smirnov-Wolfenstein (MSW) effects, the collective effects, and the Earth matter effects in the detection of type II supernova neutrinos on the Earth. It is found that the event number of supernova neutrinos depends on the neutrino mass hierarchy, the neutrino mixing angle $θ_{13}$, and neutrino masses. Therefore, we propose possible methods to identify the mass hierarchy and acquire information about $θ_{13}$ and neutrino masses by detecting supernova neutrinos. We apply these methods to some current neutrino experiments.

astro-ph.HE↗
arXiv2009

Supernova Neutrinos Detection On Earth

In this paper, we first discuss the detection of supernova neutrino on Earth. Then we propose a possible method to acquire information about $θ_{13}$ smaller than $1.5^\circ$ by detecting the ratio of the event numbers of different flavor supernova neutrinos. Such an sensitivity cannot yet be achieved by the Daya Bay reactor neutrino experiment.

hep-ph↗
arXiv2009

Realistic Earth matter effects and a method to acquire information about small θ_{13} in the detection of supernova neutrinos

In this paper, we first calculate the realistic Earth matter effects in the detection of type II supernova neutrinos at the Daya Bay reactor neutrino experiment which is currently under construction. It is found that the Earth matter effects depend on the neutrino incident angle $θ$, the neutrino mass hierarchy $Δm_{31}^{2}$, the crossing probability at the high resonance region inside the supernova, $P_{H}$, the neutrino temperature, $T_α$, and the pinching parameter in the neutrino spectrum, $η_α$. We also take into account the collective effects due to neutrino-neutrino interactions inside the supernova. With the expression for the dependence of $P_H$ on the neutrino mixing angle $θ_{13}$, we obtain the relations between $θ_{13}$ and the event numbers for various reaction channels of supernova neutrinos. Using these relations, we propose a possible method to acquire information about $θ_{13}$ smaller than $1.5^\circ$. Such a sensitivity cannot yet be achieved by the Daya Bay reactor neutrino experiment which has a sensitivity of the order of $θ_{13}\sim 3^\circ$. Furthermore, we apply this method to other neutrino experiments, i.e. Super-K, SNO, KamLAND, LVD, MinBooNE, Borexino, and Double-Chooz. We also study the energy spectra of the differential event numbers, ${\rm d}N/{\rm d}E$.

hep-ph↗
arXiv2006

Earth Matter Effects in Detection of Supernova Neutrinos

We calculated the matter effect, including both the Earth and supernova, on the detection of neutrinos from type II supernovae at the proposed Daya Bay reactor neutrino experiment. It is found that apart from the dependence on the flip probability P_H inside the supernova and the mass hierarchy of neutrinos, the amount of the Earth matter effect depends on the direction of the incoming supernova neutrinos, and reaches the biggest value when the incident angle of neutrinos is around 93^\circ. In the reaction channel \barν_e + p --> e^+ + n the Earth matter effect can be as big as about 12%. For other detection processes the amount of the Earth matter effect is a few per cent.

hep-ph↗
arXiv2005

Detecting dark energy in long baseline neutrino oscillations

In this paper, we discuss a possibility of studying properties of dark energy in long baseline neutrino oscillation experiments. We consider two types of models of neutrino dark energy. For one type of models the scalar field is taken to be quintessence-like and for the other phantom-like. In these models the scalar fields couple to the neutrinos to give rise to a spatially varying neutrino masses. We will show that the two types of models predict different behaviors of the spatial variation of the neutrino masses inside Earth and consequently result in different signals in long baseline neutrino oscillation experiments.

hep-ph↗
arXiv2005

Flavor-changing Top Quark Decays In R-Parity Violating SUSY

The flavor changing top quark decays t -> cV (V=Z,photon,gluon) induced by R-parity-violating couplings in the minimal supersymmetric standard model (MSSM) are evaluated. We find that the decays t -> cV can be significantly enhanced relative to those in the R-parity conserving SUSY model. Our results show that the top quark FCNC decay can be as large as Br(t->cg)=10^-3, Br(t->cZ)=10^-4 and Br(t-> cγ)= 10^-5, which may be observable at the upgraded Tevatron and/or the LHC.

hep-ph↗
arXiv2003

Modeling realistic Earth matter density for CP violation in neutrino oscillation

We examine the effect of a more realistic Earth matter density model which takes into account of the local density variations along the baseline of a possi ble 2100 km very long baseline neutrino oscillation experiment. Its influence to the measurement of CP violation is investigated and a comparison with the commonly used global density models made. Significant differences are found in the comparison of the results of the different density models.

hep-ph↗
arXiv2002

Measuring CP violation and mass ordering in joint long baseline experiments with superbeams

We propose to measure the CP phase $δ_{\rm CP}$, the magnitude of the neutrino mixing matrix element $|U_{e3}|$ and the sign of the atmopheric scale mass--squared difference $Δ{\rm m}^2_{31}$ with a superbeam by the joint analysis of two different long baseline neutrino oscillation experiments. One is a long baseline experiment (LBL) at 300 km and the other is a very long baseline (VLBL) experiment at 2100 km. We take the neutrino source to be the approved high intensity proton synchrotron, HIPA. The neutrino beam for the LBL is the 2-degree off-axis superbeam and for the VLBL, a narrow band superbeam. Taking into account all possible errors, we evaluate the event rates required and the sensitivities that can be attained for the determination of $δ_{\rm CP}$ and the sign of $Δm^2_{31}$. We arrive at a representative scenario for a reasonably precise probe of this part of the neutrino physics.

hep-ph↗
arXiv2001

Probing neutrino oscillations jointly in long and very long baseline experiments

We examine the prospects of making a joint analysis of neutrino oscillation at two baselines with neutrino superbeams. Assuming narrow band superbeams and a 100 kt water Cerenkov calorimeter, we calculate the event rates and sensitivities to the matter effect, the signs of the neutrino mass differences, the CP phase and the mixing angle θ_{13}. Taking into account all possible experimental errors under general consideration, we explored the optimum cases of narrow band beam to measure the matter effect and the CP violation effect at all baselines up to 3000 km. We then focus on two specific baselines, a long baseline of 300 km and a very long baseline of 2100 km, and analyze their joint capabilities. We found that the joint analysis can offer extra leverage to resolve some of the ambiguities that are associated with the measurement at a single baseline.

hep-ph↗
arXiv2001

On the Optimum Long Baseline for the Next Generation Neutrino Oscillation Experiments

For high energy long baseline neutrino oscillation experiments, we propose a Figure of Merit criterion to compare the statistical quality of experiments at various oscillation distances under the condition of identical detectors and a given neutrino beam. We take into account all possible experimental errors under general consideration. In this way the Figure of Merit is closely related to the usual statistical criterion of number of sigmas. We use a realistic neutrino beam for an entry level neutrino factory and a possible superbeam from a meson source and a 100 kt detector for the calculation. We considered in detail four oscillation distances, 300 km, 700 km, 2100 km and 3000 km, in the neutrino energy range of 0.5-20 GeV for a 20 GeV entry level neutrino factory and a 50 GeV superbeam. We found that the very long baselines of 2100 km and 3000 km are preferred for the neutrino factory according to the figure of merit criterion. Our results also show that, for a neutrino factory, lower primary muon energies such as 20 GeV are preferred rather than higher ones such as 30 or 50 GeV. For the superbeam, the combination of a long baseline such as 300 km and a very long baseline like 2100 km will form a complete measurement of the oscillation parameters besides the CP phase. To measure the CP phase in a superbeam, a larger detector (a factor 3 beyond what is considered in this article) and/or a higher intensity beam will be needed to put some significant constraints on the size of the CP angle.

hep-ph↗
arXiv2001

Prospect of a very long baseline neutrino oscillation experiment: HIPA to Beijing

We discuss the prospects of a very long baseline neutrino oscillation experiment from HIPA to Beijing. The current understanding of neutrino oscillations, both theoretically and experimentally, are summarized. The figure of merits for interested physics measurements are defined and compared at different distances: 300 km, 700 km, 2100 km and 3000 km. We conclude that a baseline more than 2100 km is optimal. A large water cerenkov calorimeter was proposed and its performance is satisfactory from a Monte Carlo simulation study. Such a large detector can do many other measurements on cosmic-rays physics and astrophysics.

hep-ph↗
arXiv2001

Probing R-violating top quark decays at the NLC

We examine the possibility of observing exotic top quark decays via $R$-Parity violating SUSY interactions in $e^+e^-$ collisions at $\sqrt{s = 500 GeV$. We present cross-sections for $t\bar t$ production followed by the subsequent decay of either the $t$ or $\overline{t}$ via the $R$-Parity violating interaction while the other undergoes the SM decay. We discuss kinematic cuts that allow the exotic SUSY decays to be detected over standard model backgrounds. Discovery limits for $R$-Parity violating couplings in the top sector are presented assuming an integrated luminosity of $100 fb^{-1}$.

hep-ph↗
arXiv2000

Probing R-violating top quark decays at hadron colliders

We examine the possibility of observing exotic top quark decays via R-violating SUSY interactions at the Fermilab Tevatron and CERN LHC. We present cross-sections for $t\bar t$ production followed by the subsequent decay of either $t$ or $\bar t$ via the R-violating interaction while the other undergoes the SM decay. With suitable kinematic cuts, we find that the exotic decays can possibly be detected over standard model backgrounds at the future runs of the Tevatron and LHC, but not at Run 1 of the Tevatron due to limited statistics. Discovery limits for R-Violating couplings in the top sector are presented.

hep-ph↗
arXiv2000

Searching for a stop-pair sample from top counting experiments at hadron colliders

The light stop pair if produced in hadron colliders and decaying through the likely decay chain stop->chargino + b followed by chargino->neutralino + f f', can mimic closely a top quark event when the mass of the stop is close to that of the top quark. Because of the much lower production rate, the stop event can be buried under the top quark event sample. In order to uncover the stop event, specific selection cuts need to be applied. Through Monte Carlo simulation with suitable kinematic cuts, we found that such stop event can be extracted from the top quark sample and detected by the top quark counting experiments in the upcoming upgraded Tevatron and LHC. However, because of the small statistics of the Run 1 of the Tevatron, the stop signal remains hidden at Run 1.

hep-ph↗