Abstract
The T2K experiment presents new measurements of neutrino oscillation parameters using
$$19.7(16.3)\times 10^{20}$$
19.7
(
16.3
)
×
10
20
protons on target (POT) in (anti-)neutrino mode at ...the far detector (FD). Compared to the previous analysis, an additional
$$4.7\times 10^{20}$$
4.7
×
10
20
POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on
$$\sin ^2\theta _{13}$$
sin
2
θ
13
and the impact of priors on the
$$\delta _{\textrm{CP}}$$
δ
CP
measurement. Both analyses prefer the normal mass ordering and upper octant of
$$\sin ^2\theta _{23}$$
sin
2
θ
23
with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on
$$\sin ^2\theta _{13}$$
sin
2
θ
13
from reactors,
$$\sin ^2\theta _{23}=0.561^{+0.021}_{-0.032}$$
sin
2
θ
23
=
0
.
561
-
0.032
+
0.021
using Feldman–Cousins corrected intervals, and
$$\varDelta {}m^2_{32}=2.494_{-0.058}^{+0.041}\times 10^{-3}~\text {eV}^2$$
Δ
m
32
2
=
2
.
494
-
0.058
+
0.041
×
10
-
3
eV
2
using constant
$$\varDelta \chi ^{2}$$
Δ
χ
2
intervals. The CP-violating phase is constrained to
$$\delta _{\textrm{CP}}=-1.97_{-0.70}^{+0.97}$$
δ
CP
=
-
1
.
97
-
0.70
+
0.97
using Feldman–Cousins corrected intervals, and
$$\delta _{\textrm{CP}}=0,\pi $$
δ
CP
=
0
,
π
is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than
$$2\sigma $$
2
σ
credible level using a flat prior in
$$\delta _{\textrm{CP}},$$
δ
CP
,
and just below
$$2\sigma $$
2
σ
using a flat prior in
$$\sin \delta _{\textrm{CP}}.$$
sin
δ
CP
.
When the external constraint on
$$\sin ^2\theta _{13}$$
sin
2
θ
13
is removed,
$$\sin ^2\theta _{13}=28.0^{+2.8}_{-6.5}\times 10^{-3},$$
sin
2
θ
13
=
28
.
0
-
6.5
+
2.8
×
10
-
3
,
in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
An upgrade of the near detector of the T2K long baseline neutrino oscillation experiment is currently being conducted. This upgrade will include two new Time Projection Chambers, each equipped with ...16 charge readout resistive Micromegas modules.
A procedure to validate the performance of the detectors at different stages of production has been developed and implemented to ensure a proper and reliable operation of the detectors once installed. A dedicated X-ray test bench is used to characterize the detectors by scanning each pad individually and to precisely measure the uniformity of the gain and the deposited energy resolution over the pad plane. An energy resolution of about 10% is obtained.
A detailed physical model has been developed to describe the charge dispersion phenomena in the resistive Micromegas anode. The detailed physical description includes initial ionization, electron drift, diffusion effects and the readout electronics effects. The model provides an excellent characterization of the charge spreading of the experimental measurements and allowed the simultaneous extraction of gain and charge spreading information of the modules.
The T2K experiment presents new measurements of neutrino oscillation parameters using
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
...\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$19.7(16.3)\times 10^{20}$$\end{document}
19.7
(
16.3
)
×
10
20
protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$4.7\times 10^{20}$$\end{document}
4.7
×
10
20
POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\sin ^2\theta _{13}$$\end{document}
sin
2
θ
13
and the impact of priors on the
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\delta _{\textrm{CP}}$$\end{document}
δ
CP
measurement. Both analyses prefer the normal mass ordering and upper octant of
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\sin ^2\theta _{23}$$\end{document}
sin
2
θ
23
with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\sin ^2\theta _{13}$$\end{document}
sin
2
θ
13
from reactors,
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\sin ^2\theta _{23}=0.561^{+0.021}_{-0.032}$$\end{document}
sin
2
θ
23
=
0
.
561
-
0.032
+
0.021
using Feldman–Cousins corrected intervals, and
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\varDelta {}m^2_{32}=2.494_{-0.058}^{+0.041}\times 10^{-3}~\text {eV}^2$$\end{document}
Δ
m
32
2
=
2
.
494
-
0.058
+
0.041
×
10
-
3
eV
2
using constant
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\varDelta \chi ^{2}$$\end{document}
Δ
χ
2
intervals. The CP-violating phase is constrained to
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\delta _{\textrm{CP}}=-1.97_{-0.70}^{+0.97}$$\end{document}
δ
CP
=
-
1
.
97
-
0.70
+
0.97
using Feldman–Cousins corrected intervals, and
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\delta _{\textrm{CP}}=0,\pi $$\end{document}
δ
CP
=
0
,
π
is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$2\sigma $$\end{document}
2
σ
credible level using a flat prior in
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\delta _{\textrm{CP}},$$\end{document}
δ
CP
,
and just below
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$2\sigma $$\end{document}
2
σ
using a flat prior in
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\sin \delta _{\textrm{CP}}.$$\end{document}
sin
δ
CP
.
When the external constraint on
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\sin ^2\theta _{13}$$\end{document}
sin
2
θ
13
is removed,
\documentclass12pt{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\sin ^2\theta _{13}=28.0^{+2.8}_{-6.5}\times 10^{-3},$$\end{document}
sin
2
θ
13
=
28
.
0
-
6.5
+
2.8
×
10
-
3
,
in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
The main source of systematic uncertainty on neutrino cross section measurements at the GeV scale originates from the poor knowledge of the initial flux. The reduction of this uncertainty to ...1% can be achieved through the monitoring of charged leptons produced in association with neutrinos. The goal of the ENUBET ERC project is to prove the feasibility of such a monitored neutrino beam. In this contribution, the final results of the ERC project, together with the complete assessment of the feasibility of its concept, are presented. An overview of the detector technology for a next generation of high precision neutrino-nucleus cross section measurements, to be performed with the ENUBET neutrino beam, is also given.
Abstract
We present the development of neutron-tagging techniques in
Super-Kamiokande IV using a neural network analysis. The detection
efficiency of neutron capture on hydrogen is estimated to be ...26%,
with a mis-tag rate of 0.016 per neutrino event. The uncertainty of
the tagging efficiency is estimated to be 9.0%. Measurement of the
tagging efficiency with data from an Americium-Beryllium calibration
agrees with this value within 10%. The tagging procedure was
performed on 3,244.4 days of SK-IV atmospheric neutrino data,
identifying 18,091 neutrons in 26,473 neutrino events. The fitted
neutron capture lifetime was measured as 218±9 μs.
Abstract
The ENUBET ERC project, also included in the CERN Neutrino Platform as NP06/ENUBET, is developing a new neutrino beam based on conventional techniques in which the flux and the flavor ...composition are known with unprecedented precision (
O
(1%)). Such a goal is accomplished monitoring the associated charged leptons produced in the decay region of the ENUBET facility. Positrons and muons from kaon decays are measured by a segmented calorimeter instrumenting the walls of the decay tunnel, while muon stations after the hadron dump can be used to monitor the neutrino component from pion decays. Furthermore, the narrow momentum width (<10%) of the beam provides a precise measurement (
O
(10%)) of the neutrino energy on an event by event basis, thanks to its correlation with the radial position of the interaction at the neutrino detector. ENUBET is therefore an ideal facility for a high precision neutrino cross-section measurement at the GeV scale, that could enhance the discovery potential of the next-generation of long baseline experiments. It is also a powerful tool for testing the sterile neutrino hypothesis and to investigate possible non-standard interactions.
Abstract
A search for neutrinos produced in coincidence with gamma-ray bursts (GRBs) was conducted with the Super-Kamiokande (SK) detector. Between December 2008 and March 2017, the Gamma-ray ...Coordinates Network recorded 2208 GRBs that occurred during normal SK operation. Several time windows around each GRB were used to search for coincident neutrino events. No statistically significant signal in excess of the estimated backgrounds was detected. The $\bar\nu_e$ fluence in the range from 8 MeV to 100 MeV in positron total energy for $\bar\nu_e+p\rightarrow e^{+}+n$ was found to be less than $\rm 5.07\times10^5$ cm$^{-2}$ per GRB at a 90% confidence level. For all GRBs, upper bounds were obtained on the fluence as a function of neutrino energy. Additionally, for GRBs at known distances, upper limits were set for the neutrino energy emission at the GRB.
Abstract The T2K experiment presents new measurements of neutrino oscillation parameters using $$19.7(16.3)\times 10^{20}$$ 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at ...the far detector (FD). Compared to the previous analysis, an additional $$4.7\times 10^{20}$$ 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on $$\sin ^2\theta _{13}$$ sin 2 θ 13 and the impact of priors on the $$\delta _{\textrm{CP}}$$ δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of $$\sin ^2\theta _{23}$$ sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on $$\sin ^2\theta _{13}$$ sin 2 θ 13 from reactors, $$\sin ^2\theta _{23}=0.561^{+0.021}_{-0.032}$$ sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman–Cousins corrected intervals, and $$\varDelta {}m^2_{32}=2.494_{-0.058}^{+0.041}\times 10^{-3}~\text {eV}^2$$ Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant $$\varDelta \chi ^{2}$$ Δ χ 2 intervals. The CP-violating phase is constrained to $$\delta _{\textrm{CP}}=-1.97_{-0.70}^{+0.97}$$ δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman–Cousins corrected intervals, and $$\delta _{\textrm{CP}}=0,\pi $$ δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than $$2\sigma $$ 2 σ credible level using a flat prior in $$\delta _{\textrm{CP}},$$ δ CP , and just below $$2\sigma $$ 2 σ using a flat prior in $$\sin \delta _{\textrm{CP}}.$$ sin δ CP . When the external constraint on $$\sin ^2\theta _{13}$$ sin 2 θ 13 is removed, $$\sin ^2\theta _{13}=28.0^{+2.8}_{-6.5}\times 10^{-3},$$ sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The ENUBET experiment is developing a new narrow-band neutrino beam in which the flux and the flavor composition are known at 1
level, and the energy with O(10
) precision. Such a goal is ...accomplished monitoring the associated charged leptons produced in the decay region of the ENUBET facility:
and
from kaons are measured by a segmented calorimeter instrumenting the walls of the decay tunnel, while muon stations after the hadron dump can monitor muons from pions. We report an update on the status of the project.
PDF
