Satoshi Nakamura Osaka University Japan Collaborators H Kamano RCNP Osaka Univ T Sato Osaka Univ TSH Lee Argonne Natl Lab Contents Introduction ID: 341266
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Slide1
Neutrino-induced meson productions
Satoshi Nakamura Osaka University, Japan
Collaborators : H.
Kamano
(RCNP, Osaka Univ.), T. Sato (Osaka Univ.)
T.-S.H. Lee (Argonne Nat’l Lab)Slide2
Contents
Introduction
nN
scattering in resonance region
Dynamical coupled-channels (DCC)
model
Analysis
of
g
N
,
pN
pN
,
hN
, KL, KS
data
Extension
to
nN
l
-
X
(
X=
pN
,
ppN
,
hN
, KL, KS
)
R
esults for
nN
l
-
X
Slide3
Introduction Slide4
Neutrino-nucleus scattering
for n-oscillation experiments
n
Neutrino-nucleus interactions
neutrino
detectors
(
16
O,
12
C,
36
Ar, …
)
Neutrino-nucleus
interactions need to be known for neutrino flux measurementSlide5
DIS
region
QE
region
RES
region
Next-generation exp.
leptonic
CP, mass hierarchy
n-
nucleus scattering needs to be understood more precisely
Wide kinematical region with different characteristic
Combination of different expertise is necessary
Collaboration at J-PARC Branch of KEK Theory
C
enter
http
://j-parc-th.kek.jp/html/English/e-index.html
T2K
Neutrino-nucleus
scattering
for
n
-oscillation experiments
Atmospheric
nSlide6
Resonance region
(single nucleon)
D
2nd
3rd
Multi-channel reaction
2
p
production is comparable to 1
p
h
,
K
productions (
n
case: background of proton decay exp.)
(MeV)
(Data)
gN
X
Slide7
GOAL : Develop
nN-interaction model in resonance region
We develop a
Unitary coupled-channels
model
(multi-channel)
Unitarity
is missing
Important
2
p
production
model is missing
Problems in previous models
Dynamical coupled-channels (DCC) model for gN
, pN
pN
,
ppN
,
hN
, KL,
KS
Extension to
nN
l
-X ( X= pN, ppN
, hN, KL, KS
)
Our strategy to overcome the problems…Slide8
Dynamical Coupled-Channels
model for meson productionsSlide9
,
Coupled-channel
unitarity
is fully taken into account
Kamano
et al., PRC 88, 035209
(2013
)
In addition,
gN
,
W±N, ZN channels are included perturbativelySlide10
DCC analysis of meson production data
Fully combined analysis of gN
,
pN
pN
,
hN
, KL
, KS data
and polarization observables
(W ≤ 2.1 GeV)~380 parameters
(N* mass, N*
MB
couplings, cutoffs)
to fit
~ 20,000
data points
Kamano
, Nakamura, Lee, Sato, PRC 88 (2013)Slide11
Partial wave amplitudes of
p
N scattering
Kamano
, Nakamura, Lee, Sato,
PRC 88 (2013)
Previous model
(fitted to
p
N
p
N
data
only
)
[PRC76 065201 (2007)]
Real part
Imaginary part
Data: SAID
pN
amplitude
Constraint on axial current through PCAC Slide12
Kamano, Nakamura, Lee, Sato, 2012
Vector current (Q
2
=0) for 1
p
Production
is well-tested by data
Kamano
, Nakamura, Lee, Sato, PRC 88 (2013)Slide13
Model for vector & axial currents is necessary
Extension to full kinematical region
Q
2
≠0
DCC model
for neutrino interaction
n
F
orward
limit
Q
2
=
0
Kamano
, Nakamura, Lee, Sato, PRD 86
(2012)
s
pN
X
snN
X via PCACSlide14
Vector current
Q2
=0
g
p
MB
gn
pN
isospin separation
necessary for calculating n-interaction
Q2
≠0
(electromagnetic form factors for
VNN*
couplings
)
obtainable from (
e,e
’
p
),
(
e,e
’ X) data analysis
We’ve done first analysis of all these reactions
VNN*(
Q2) fixed neutrino reactions
DCC model for neutrino interactionSlide15
Q2
=0 non-resonant mechanisms
resonant mechanisms
Interference among resonances and background can be made under control within DCC model
Axial current
DCC model
for neutrino interaction
Caveat :
phenomenological axial currents are added to maintain PCAC relation
to be improved in future Slide16
Axial current
Q2≠
0
non-resonant mechanisms
resonant mechanisms
DCC model
for neutrino interaction
M
A
=
1.02
GeV
:
axial
form factors
More neutrino
data are necessary to
fix axial form factors for
ANN
*
Sato et al. PRC 67 (2003)
Neutrino cross sections will be predicted with this axial current for this presentationSlide17
Analysis of electron scattering dataSlide18
p(e,e’
p
0
)
p
p
(e,
e’p+
)n
both
Analysis of electron-proton scattering dataPurpose
: Determine Q2 –dependence of vector coupling of p-N* :
VpN*(Q
2
)
Data
:
*
1
p
electroproduction
Database
* Empirical inclusive inelastic structure functions
s
T
,
s
L
Christy et al, PRC 81 (2010)
r
egion where inclusive
s
T
&
s
L
are fittedSlide19
Analysis result
Q2
=0.40 (
GeV
/
c
)
2
s
T
+ e s
L for
W=1.1 – 1.68 GeV
p(
e,e’
p
0
)
p
p
(
e,e’
p
+
)
nSlide20
Analysis result
Q
2
=0.40 (
GeV
/
c
)
2
s
T
&
sL (inclusive inelastic)
DCC
Christy et al PRC 81
s
T
s
L
r
egion where inclusive
s
T
&
s
L
are fittedSlide21
For application to neutrino interactions
Analysis of electron scattering data
VpN
*
(
Q
2
)
&
VnN*(Q2
) fixed for several Q
2 values
Parameterize
VpN*(Q2) & VnN
*(Q
2
)
with simple analytic function of
Q
2
I
=3/
2
:
VpN*(Q2
) = VnN*(
Q2) CC, NC I=1/
2 isovector part : (
VpN*(Q2) -
VnN*(Q2) ) / 2
CC, NC I=1/2 isoscalar part : ( VpN*(Q
2) +
VnN*(Q2) ) / 2 NC
DCC vector currents has been tested by data for whole kinematical regionrelevant to neutrino interactions of E
n ≤ 2
GeVSlide22
Neutrino ResultsSlide23
Caveat
Results presented here are still preliminaryC
areful examination needs to be made to obtain a final resultSlide24
C
ross section for
n
m
N
m
-
X
pN
&
ppN are main channels in few-GeV
regionhN
,
K
Y
cross sections are 10
-1
–
10
-2
smaller
n
m
n
m
-
X
n
m
p m-
X Slide25
Comparison with
n
m
N
m
-
p N
data
ANL Data : PRD 19, 2521 (1979)BNL Data : PRD
34, 2554 (1986)DCC model prediction slightly undershoots data
DCC model has flexibility to fit data (
ANN*(Q
2
)
)
Data should be analyzed with nuclear effects
n
m
n
m
-
p
N
n
m
p
m-p
+ p Slide26
Mechanisms for
n
m
N
m
-
p N
D(1232)
dominates for nm p
m
-
p
+
p
(
I
=3/2)
for
E
n
≤ 2 GeVNon-resonant mechanisms contribute significantlyHigher
N*s
becomes important towards En ≈
2 GeV for nm
n m- p N
nm n
m-
p
N
n
m
p
m
-
p
+
p
D(1232)
D(1232)Slide27
ds /
dW dQ2
( ×10
-38
cm
2
/ GeV
2
)
n
m
n
m
-
p
N
n
m
n
m
-
pp
N
n
m
p m
-p+ p n
m p
m-pp N
En
=
2
GeV
Slide28
ConclusionSlide29
Development of DCC model for
nN interaction in resonance region
pN
&
ppN
are main channels in few-
GeV
regionDCC model prediction slightly undershoots data
D, N*s, non-resonant are all important in few-
GeV region (for n
m n
m- X
)
essential to understand interference pattern among them
DCC model can do this; consistency between
p
interaction and axial current
Start with DCC
model for
gN
,
pN
pN, ppN
, hN, KL
, KS extension of vector current to Q2≠0
region, isospin separation through analysis of e
—- p & e—-’n’ data for W ≤
2 GeV , Q
2≤ 3 (GeV/c)2Development of axial current for nN
interaction; PCAC is maintained
ConclusionSlide30
Future development
Axial form factor more neutrino data is ideal
p N
r
N
(t-ch
p) (possible at J-PARC)
ppN
channel p N
pp N
experiment (J-PARC, K. Hicks et al.)
g
N
pp
N
experiment
(ELPH,
JLab
) Slide31
BACKUPSlide32
Physics at J-PARC: Charm, Neutrino, Strangeness, and Spin
T2K
(Tokai to
Kamioka
) experiment for
neutrino oscillation
measurement
Far Detector
(Super
Kamiokande
)
T2K measures neutrino fluxes at
near
and
far detectorsJ-PARC produces neutrino beam directed to Super
Kamiokande by
Proton + nucleus
p
-
(
p
+
) + ….
n
m
+
m
- (n
m
+ m + )
_Slide33
Neutrino oscillation
Expected
n
m
fluxes in T2K
Near detector
F
ar detector
E
n
(
GeV
)
n
m
survival probability
(two-flavor case)
q
:
mixing angle
D
m
2
(eV
2
) =
m
1
2
–
m
2
2
L (km) : distance between J-PARC and SKEn (
GeV) : neutrino energy
Comparing data to oscillation formula, mixing parameters (q , Dm2 ) can be determinedComparing n data with
n data
leptonic CP violation ( dCP ) _Slide34
T2K
Quasi-elastic (QE) is dominant
n
-flux is measured by detecting QE
1
p
production via
D-
excitation
is major background p
can be absorbed
QE is contaminated
n
m
m
-
n
m
m
-
D
LBNE and other planned experiments
( higher energy
n
-
beam)
DIS and higher nucleon resonances are main mechanisms
In this work,
w
e focus on
resonance region, single nucleon processes
basic ingredient for neutrino-nucleus interaction modelSlide35
DCC model
for neutrino interaction
n
s
pN
X
is from our DCC model
v
ia
PCAC
nN
l
X
(
X =
pN
,
ppN
,
hN
, KL, KS
)
a
t forward limit Q2=
0
Kamano, Nakamura, Lee, Sato, PRD 86 (2012) pN
ppN
KSSlide36
Formalism
Cross section for
nN
l
X
(
X =
pN
, ppN,
hN, KL, KS )
q
0
Q
2
0
CVC & PCAC
LSZ & smoothness
Finally
s
pN
X
is from our DCC modelSlide37
Results
SL
p
N
pp
N
KS
h
N
KL
Prediction based on model well tested by
data (
first
nN
ppN
)
pN
dominates for
W
≤
1.5
GeV
ppN
becomes comparable to
pN
for
W
≥ 1.5
GeVSmaller contribution from
hN and KY O(10-1) - O(10-2)
Agreement with SL (no PCAC) in D
regionSlide38
Comparison with Rein-Sehgal
model
Lower
D
peak of RS model
RS overestimate in higher energy regions
(DCC model is tested by data)
Similar findings by
Leitner
et al.,
PoS
NUFACT08 (2008) 009
Graczyk et al.,
Phys.Rev. D77 (2008) 053001
Comparison in whole kinematical region will be done
after axial current model is developedSlide39
F2 from RS modelSlide40
SL model applied to
n-nucleus scattering
1
p
production
Szczerbinska
et al. (2007)Slide41
SL model applied to
n-nucleus scattering
coherent
p
production
g
+
12
C
p
0 + 12C
nm
+ 12C
m
-
+
p
0
+
12
C
Nakamura et al. (2010)Slide42Slide43
Previous models for
n-induced 1
p
production in resonance region
Rein et al. (1981), (1987) ;
Lalalulich
et al. (2005), (2006)
Hernandez et al. (2007), (2010) ;
Lalakulich
et al. (2010)
Sato, Lee (2003), (2005)
r
esonant only
+ non-resonant
(tree-level)
+
rescattering
(
p
N
unitarity
)Slide44
Eta production reactions
Kamano, Nakamura, Lee, Sato
, 2012Slide45
KY production reactions
1732 MeV
1845
MeV
1985
MeV
2031
MeV
1757
MeV
1879
MeV
1966
MeV
2059
MeV
1792
MeV
1879
MeV
1966
MeV
2059
MeV
Kamano, Nakamura, Lee, Sato
, 2012Slide46Slide47
Kamano
, Nakamura, Lee, Sato,
arXiv:
1305.4351
Vector current (Q
2
=0) for
h
Production
i
s well-tested by dataSlide48
Vector current (Q
2
=0) for
K
Production
i
s well-tested by data
Kamano
, Nakamura, Lee, Sato,
arXiv:
1305.4351Slide49Slide50
Kamano, Nakamura, Lee, Sato, PRC 88 (2013)
“N” resonances
(I=1/2)
J
P
(L
2I 2J
)
Re(M
R
)
“Δ” resonances (I=3/2)
PDG: 4* & 3*
states
assigned by PDG2012
AO : ANL-Osaka
J :
Juelich
(DCC)
[EPJA49(2013)44, Model A]
BG : Bonn-
Gatchina
(K-matrix)
[EPJA48(2012)5]
-2Im(M
R
)
(“width”)Slide51
Kamano, Nakamura, Lee, Sato, 2012
Quality of describing data
with DCC model
Model is extensively tested by
gN
,
pN
pN
,
hN
, KL, KS
data
(
W
≤ 2.1
GeV
,
~
20,000
data points
)
application
to
n
-scattering
reliable vector current (Q2
= 0) pN
X model combined with PCAC
Kamano, Nakamura, Lee, Sato, PRC 88 (2013)Slide52
Analysis result
Q2
=0.16 (
GeV
/
c
)
2
s
T
+
e sL
for W=1.1 - 1.32 GeV
p
(
e,e’
p
0
)
p
p
(
e,e’
p
+
)
nSlide53
Analysis result
Q2
=0.16 (
GeV
/
c
)
2
s
T
&
sL
(inclusive inelastic)
DCC
Christy et al PRC 81
s
T
s
L
r
egion where inclusive
s
T
&
s
L
are fittedSlide54
Analysis result
Q2
=2.95 (
GeV
/
c
)
2
s
T
+ e s
L for
W=1.11 – 1.69 GeV
p(e,e’
p
0
)
p
p
(
e,e’
p
+
)
nSlide55
Analysis result
Q
2
=2.95 (
GeV
/
c
)
2
s
T
&
sL (inclusive inelastic)
DCC
Christy et al PRC 81
s
T
s
L
r
egion where inclusive
s
T
&
s
L
are fittedSlide56
Purpose : V
ector coupling of neutron-N* and its Q
2
–dependence
:
VnN*
(Q2)
(I=1/2)
I=3/2 part has been fixed by proton target data
Analysis of electron-’neutron’ scattering data
Data
: * 1p photoproduction (Q
2=0)
* Empirical inclusive
inelastic
structure functions
s
T
,
s
L
(
Q
2
≠0)
Christy and Bosted, PRC 77 (2010), 81 (2010)Slide57
Analysis result
Q2
=0
d
s
/
d
W
(
g n p
-p) for
W=
1.1
– 2.0
GeVSlide58
Analysis result
Q
2
=1
(
GeV
/
c
)
2
s
T
&
s
L
(
inclusive inelastic
e
—
-’n’
)
DCC
Christy and
Bosted
PRC 77; 81
s
T
s
L
Q2=2 (GeV/c)2
s
L s
T
Q
2
≠0