plan for a proposal in high-energy hadorn physics at j...
Post on 16-Jun-2018
213 Views
Preview:
TRANSCRIPT
Plan for a proposal in high-energy hadorn physics at J-PARC
March 12 (Thursday), 2015
pre-workshop meeting
Discussions on J-PARC proposal on high-energy hadron physics
1
Wen-Chen Chang, Takahiro Sawada (Academia Sinica)
Jen-Chieh Peng (UIUC)
Shunzo Kumano, Shinya Sawada (KEK)
Kazuhiro Tanaka (Juntendo)
Outline
• Uniqueness of hadron physics studied at HiPBL of J-PARC
• Physics Processes under consideration:• Drell-Yan process
• Hard exclusive process
• Charm production process
• Feasibility study of exclusive Drell-Yan process in E50 spectrometer
• Summary & Questions
2
J-PARC High-momentum Beam Line(Hi-P BL)
• High-intensity secondary Pion beam
• High-resolution beam: Δp/p ~ 0.1%
3
Hadron Hall
50GeV Synchrotron
Beam Dump
50GeV Tunnel
T1 Target(30/50% Loss)
Test BL
Hi-P BL
ExtensionSM1
(2% Loss)T0
0.1% Loss)
Switchyard15kW Loss Target(SM)
30 GeV proton
J-PARC High-momentum Beam Line(Hi-P BL)
• High-intensity secondary Pion beam
• High-resolution beam: Δp/p ~ 0.1%
* Sanford-Wang: 15 kW Loss on Pt, Acceptance :1.5 msr%, 133.2 m
1.0E+03
1.0E+04
1.0E+05
1.0E+06
1.0E+07
1.0E+08
1.0E+09
0 5 10 15 20
Co
un
ts/s
ec
[GeV/c]
1.0E+03
1.0E+04
1.0E+05
1.0E+06
1.0E+07
1.0E+08
1.0E+09
0 5 10 15 20
Co
un
ts/s
ec
[GeV/c]
Negative Hadron Beams(Prod. Angle = 0 deg.)
p-
K-
pbar
p+
K+
Positive Hadron Beams(Prod. Angle = 3.1 deg.)
4
6
http://j-parc-th.kek.jp/html/English/e-index.html
Uniqueness of hadron physics studied at HiPBL of J-PARC
• The beam energy of hadrons at J-PARC at 5-15 GeV ( 𝑠 = 𝟑 − 𝟓. 𝟓 GeV) might be most ideal for studying the hard exclusive processes and discerning the quark-hadron transition in the strong interaction.
• Valance-like partonic degrees of freedom of hadrons could be discerned, compared to the collisions at low-energy regime.
• Reasonably large cross sections, compared to those at higher energies.
7
Constituent-Counting Rule in Hard Exclusive Process Kawamura et al., PRD 88, 034010 (2013)
8
p n p ++ +0Kpp - + +
2
1( ) ( ) CMn a b c d
da b n nc d f
dt sn n n
-++ + ++
1 3 2 3 7n + + + 2 3 2 3 8n + + +
Physics Processes
• Drell-Yan process– Inclusive pion-induced Drell-Yan:
• u/d(x) at large x
• Violation of Lam-Tung relation, BM functions
• Pion PDF and DA
– Exclusive pion-induced Drell-Yan• GPD and TDA of proton
• Pion DA
• Hard exclusive production process– Exclusive pion-N Lambda(1405) production
• Valence quark structure of Lambda(1405)
• Charm production process– Inclusive pion-N J/psi production: J/psi production mechanism
– Exclusive pion-N J/psi production: Intrinsic charm?
– Exotic charmed baryons
9
Quark and Gluon Wigner Phase-Space
Distributions in Protons
10
Wigner Distribution
Transverse Momentum
Dependent PDF
Generalized Parton Distr.
PDF Form Factors
GPD
Ji, PRL91,062001(2003)
( , , )TW r x k
f( , )Tx k
f( )x
F( , , t)x
1 2( ), ( )F t F t
dr
Tdk dx0 & 0x
iq r
Te drdk
2/ 2 , z
qq E t q -
Naïve Assumption:
NMC (Gottfried Sum
Rule):
NA51 (Drell-Yan, 1994):
E866/NuSea (Drell-Yan,
1998):
Light Antiquark Flavor Asymmetry: Drell-Yan Experiments with Proton Beam
11
Tevatro
n 800
GeVMain Injector 120 GeV
𝑑(𝑥)/ 𝑢(𝑥) Measured by
FNAL E906/SeaQuest Experiment
12
Fermilab E906
𝑥𝐵𝑥𝑇 =𝑀
𝑠; smaller s, larger 𝑥𝑇
Unpolarized Drell-Yan using 120
GeV proton beam from Main
Injector
1H, 2H, and nuclear targets
( ( ) / ( )) up to 0.45Td x u x x
Ratios of d/u(x) at large x by pion-induced Drell-Yan processes• At large x1 and x2:
• With deuterium target and spectator tagging:
• With both 𝜋+ and 𝜋− beams:
17
1 2
1 2
1 2
( ) 4 ( ) ( )
( ) 4 ( ) ( )
( ) ( ) ( )
p
DY
p
DY
p
DY
p u x u x
n u x d x
p d x d x
p
p
p
p
p
p
-
-
+
-
-
+
1 2 2
21 2
( n) 4 ( )d ( ) ( )
( p) ( )4 ( ) u ( )
p p
DY
ppDY
u x x d x
u xu x x
p
p
p
p
-
-
-
-
1 2 2
21 2
( ) ( ) ( ) ( )
( p) 4 ( )4 ( ) u ( )
p p
DY
ppDY
p d x d x d x
u xu x x
p
p
p
p
+
-
+
-
No nuclear correction for deuteron is needed
Deuterium target
18
Drell-Yan decay angular distributions
Collins-Soper frame
and are the decay polar
and azimuthal angles of the
μ+ in the dilepton rest-frame
0O(
annilation parton model:
) =1, W W= =0; 1, 0T Ls
2 2
2 2 2
(1 cos sin 2 cos sin cos 2 )2
( (1 cos ) (1 cos ) sin 2 cos sin cos 2 )T LW W W W
d
d
+ + +
+ + - + +
1Collinear pQCD
Lam-Tung relation (1978)
: O 2 1 2 =0( ), ; s LW W - -
E615 @ FNAL: Violation of LT RelationPRD 39, 92 (1989)
20
252-GeV p-+W
1 2 =0 - -
cos2 modulation at large Tp
Berger and Brodsky (PRL 42, 940, (1979)) :
Higher Twist Effect at large 𝑥𝜋
2 2
2 2 2
2
4(1 ) (1 cos ) sin
9
Tx kd x
m
p
p
- + +
2(1 cos )d +
21
Brandenburg et al. (PRL 73, 939 (1994)):
Pion Distribution Amplitude
22Pion distribution amplitude: distribution of LC momentum fractions
in the lowest-particle number valence Fock state.
A. P. Bakulev, N. G. Stefanis, and O. V. Teryaev
(Phys. Rev. D 76, 074032 (2007))
Pion Distribution Amplitude
asymptotic-like form = 6y(1-y)
Chernyak-Zhitnitsky (CZ)-like form
Nonlocal QCD sum rules
23
QCD evolution
A. P. Bakulev, N. G. Stefanis, and O. V. Teryaev
(Phys. Rev. D 76, 074032 (2007))
Sensitivity of Pion DA to ,,
*
*
TP
M
0.06 0.3 0.5
24
Dimuon pairs of Large Pt or small M
Theoretical Interpretations of Lam-Tung
Violation in pion-induced DY
25
Boer-Mulders
Function
QCD chromo-
magnetic effect
Glauber gluon
Origin of effect Hadron QCD vacuum Pion specifically
Quark-flavor
dependence
Yes No No
Hadron
dependence
Yes No Yes
Large PT limit 0 Nonzero 0
Reference PRD 60,
014012 (1999)
Z. Phy. C
60,697 (1993)
PLB 726, 262
(2013)
Measurements with different beams , , , and at wide kinematical ranges
would help differentiating the origin.
p K pp
Competing with CERN COMPASS DY Program
Pasquini and Schweitzer (PRD 90, 014050 (2014))
Boer-Mulders Functions of Pion and Proton in
Light-Front Constituent Model
26
E866 (PRL 99 (2007) 082301; PRL 102 (2009) 182001)
Consistency of LT relation for DY events in pd, pp
27
Boer-Mulders functions from
unpolarized pD and pp Drell-YanZ. Lu and I. Schmidt,
PRD 81, 034023 (2010)
V. Barone et al.,
PRD 82, 114025 (2010)
Sign of BM functions and their flavor dependence? 28
u d
u d
u d
Flavor separation of the Boer–Mulders functions
Z. Lu et al. (PLB 639 (2006) 494)
29
2 22
2
cos 2 ( ) cos 2
4 4
T A B TT
A B A B T A B
q d h h llX qW d d q
M M d dx dx d q M M
MIT Bag Model Spectator Model Large Nc limit
Deuterium target
Quark and Gluon Wigner Phase-Space
Distributions in Protons
30
Wigner Distribution
Transverse Momentum
Dependent PDF
Generalized Parton Distr.
PDF Form Factors
GPD
Ji, PRL91,062001(2003)
( , , )TW r x k
f( , )Tx k
f( )x
F( , , t)x
1 2( ), ( )F t F t
dr
Tdk dx0 & 0x
iq r
Te drdk
2/ 2 , z
qq E t q -
x+ x-
t
GPD
s
PP’
( ,0,0) ( ) ( )
( ,0,0) ( ) ( )
f f f
f f f
H x q x q x
H x q x q x
- -
- -
1
1
1
1
2
1
1
1
1
1
( , , ) ( )
( , , ) ( )
( , , ) ( )
( , , ) ( )
f
f
f
f
f A
f
f p
f
dx H x t F t
dx E x t F t
dx H x t g t
dx E x t g t
-
-
-
-
-
-
-
-
)]0,,()0,,([2
1
2
11
1
xExHxdxLJ ff
ff
f ++ -
),,( txGPD
Ji’s sum rule
Generalized Parton Distribution (GPD)
2)'( PPt -
0t
5
( , , ) ( , , )
( , , ) ( , , )
f f
f f
no spin flip H x t H x t
spin flip E x t E x t
0t
31
Spacelike vs. Timelike ProcessesMuller et al., PRD 86 031502(R) (2012)
32
Deeply Virtual Compton Scattering Timelike Compton Scattering
2 0q 2 0q
t<0, space-like GPD
Spacelike vs. Timelike ProcessesMuller et al., PRD 86 031502(R) (2012)
33
Deeply Virtual Meson Production Exclusive Meson-induced DY
2 0q 2 0q
t<0, space-like GPD
𝜋𝑁 → 𝜇+𝜇−𝑁(PLB 523 (2001) 265)
𝑡 = 𝑝 − 𝑝′ 2
𝑄′2 = 𝑞′2 > 0
2 2
2
' '
2 N
Q Q
pq s M
-
( ')
( ')
p p
p p
+
+
-
+ 34
𝜋𝑁 → 𝜇+𝜇−𝑁(PLB 523 (2001) 265)
𝑡 = 𝑝 − 𝑝′ 2
𝑄′2 = 𝑞′2 > 0
2 2
2
' '
2B
N
Q Qx
pq s M
-
( ')
( ') 2
p p
p p
+
+
-
+ - 35
Differential Cross Sections (Q2,t,)E.R. Berger, M. Diehl, B. Pire, PLB 523 (2001) 265
36
𝑡 = 𝑝 − 𝑝′ 2
𝑄′2 = 𝑞′2 > 0
2 2
2
' '
2B
N
Q Qx
pq s M
-
( ')
( ') 2
p p
p p
+
+
-
+ -
Evaluation of Cross Sections
• Input:
– GPD 𝐻(𝑥, 𝜂, 𝑡;Q2), 𝐸(𝑥, 𝜂, 𝑡;Q2)
– Pion distribution amplitude (DA) φ(𝑧;Q2)
• QCD evolutions:
– GPD: Vinnikov framework for LO evolution
– Pion DA: construction by Gegenbauerpolynomials of order 3/2.
• Matrix elements of Exclusive DY.
• Differential cross sections (Q2,t,)
37
GPD 𝐻(𝑥, 𝜂, 𝑡) Double IntegrationE.R. Berger, M. Diehl, B. Pire, EPJC 23, 675 (2002)
38 𝐻(𝑥, 𝜂 = 0, 𝑡 = 0)=polarized valance distribution
𝜋𝑁 → 𝜇+𝜇−𝑁E.R. Berger, M. Diehl, B. Pire, PLB 523 (2001) 265
40
𝑸′𝟐 = 𝒒′𝟐 = 𝟓 𝑮𝒆𝑽𝟐
2 2
2
' '0.2
2 N
Q Q
pq s M
-𝑡 = 𝑝 − 𝑝′ 2=-0.2 GeV2
Cross sections increase toward small s!
blue greenred
|t|
Cross Sections of Exclusive DY
2 2
2
' '0.2
2 N
Q Q
pq s M
-
Exclusive DYd
σ/(
dQ
2d
t) (
pb
/GeV
4)
|t| (GeV2)
τ
Cross sections increase toward small s!
dσ
/(d
Q2d
t) (
pb
/GeV
4)
Goloskokov, Kroll
Berger, Diehl, Pire
VinnikovGoloskokov, Kroll
Berger, Diehl, Pire
Vinnikov
J-PARC
GPD dependence
44
A.V. Vinnikov, hep-ph/0604248
Pion Distribution Amplitude
46
QCD evolution
2 3/2 2 (3/2)
2,4,6,...
2 2
( , ) ( )[1 ( ) ( )]
3( , ) ( ) (1 )
4
asym
j j
j
asym
z Q z a Q C z
z Q z z
p p
p p
+
-
(3/2) : Gegenbauer =3/2 polynomialsjC
p DA Asymptotic Chernyak-Zhitnitsky(CZ)
Kroll Dyson-Schwinger equation(DSE)
Q2 (GeV2) infty 1 4 4
a2 0 0.56 0.22 0.20
a4 0 0 0 0.093
a6 0 0 0 0.055
Pion DA Dependence: Pire GPD
48
The differential cross sections of exclusive DY process shows good sensitivity to pion DA 𝜑𝜋(𝑧).
|t| (GeV2)
Pion DA Dependence: Kroll GPD
49
The differential cross sections of exclusive DY process shows good sensitivity to pion DA 𝜑𝜋(𝑧).
|t| (GeV2)
Pion DA Dependence
50
Kroll
Pire
Pire
Kroll
The discrimination of pion DA and GPD could be done in multi-dimensional distributions.
1.5 GeVM 15 GeVPp
Pp
Constituent-Counting Rule in Hard Exclusive ProcessKawamura et al., PRD 88, 034010 (2013)
52
p n p ++ +0Kpp - + +
2
1( ) ( ) CMn a b c d
da b n nc d f
dt sn n n
-++ + ++
1 3 2 3 7n + + + 2 3 2 3 8n + + +
WA98: pi(252GeV) N->J/psi +XPRL 58, 2523 (1987)
qqbar anihlation dominating and exclusive production?
60
H. Noumi
A neutron target would be useful for the search of some exotic charmed baryons like 𝑑𝑑𝑢𝑢 𝑐 in I=0 channel.
J-PARC E50 Spectrometer + MuID
62
p-
LH2-target
Ring ImageCherenkovCounter
Internal DC
FM magnet
ps-
K+
Fiber tracker
Beam GC
Internal TOF
Internal TOFDC
TOF wall
2m
Decay p(p+)
20 GeV/cBeam p-
Acceptance: ~ 60% for D*, ~80% for decay p+
Resolution: p/p~0.2% at ~5 GeV/c (Rigidity: ~2.1 Tm)
||<60
Scintillator Muon trigger device
+
-
10 GeV/c 20 GeV/c
Beam Intensity High
Total Cross Sectionof Exclusive DY High
High
Acceptance High
π- beam(prod. angle 0 deg)
Total Cross Section of DY
Beam Intensity High
High
Low
Low
Low
Low
Low
Low
of Inclusive DY
15 GeV/cBeam Energy
Yield Estimation
π+ beam(prod. angle 3.1 deg)
63
・ π- beam : 50 days(prod. angle 0 deg)
・ π+ beam : 150 days(prod. angle 3.1 deg)
d/u ratio
GPD
Assumptions:
• Ibeam=107 π/s, Target ; 57cm LH2 , ε(DAQ, Tracking, PID) = 0.9*0.7*0.9, 1 events/day/pb
• Beam momentum resolution: Δp/p = 0.1 %
• Detector resolution: ΔM/M = 1 %
・ Beam Time
・ J-PARC High-p Beam Line
Inclusive DY
Exclusive DY
Yield Estimation
64
Geant 4.9.3(E-50 spectrometer + Muon ID)
・ Exclusive Drell-Yancalculated with GPD by
E.R. Berger, M. Diehl, B. Pire, Eur. Phys. J. C 23, 675 (2002)
・ Inclusive Drell-Yan Pythia 6.4.26
・ BackgroundJAM 1.132
π π+
10 GeV 2.11 nb 0.323 nb
15 GeV 2.71 nb 0.493 nb
20 GeV 3.08 nb 0.616 nb
-
π π+
10 GeV 9.98 pb
15 GeV 7.53 pb
20 GeV 5.83 pb
-
π π+
10 GeV 26.9 mb 24.8 mb
15 GeV 25.8 mb 24.1 mb
20 GeV 25.1 mb 23.5 mb
-
Event GeneratorInclusive Drell-Yan (Mμμ>1.5 GeV)
Exclusive Drell-Yan (Mμμ>1.5 GeV)
Background
Total Cross Section
Particle Transportation + Detector
Yield Estimation
65
π π+
10 GeV 2.11 nb 0.323 nb
15 GeV 2.71 nb 0.493 nb
20 GeV 3.08 nb 0.616 nb
-
π π+
10 GeV 9.98 pb
15 GeV 7.53 pb
20 GeV 5.83 pb
-
π π+
10 GeV 26.9 mb 24.8 mb
15 GeV 25.8 mb 24.1 mb
20 GeV 25.1 mb 23.5 mb
-
Inclusive Drell-Yan (Mμμ>1.5 GeV)
Exclusive Drell-Yan (Mμμ>1.5 GeV)
Background
・ Exclusive Drell-Yancalculated with GPD by
E.R. Berger, M. Diehl, B. Pire, Eur. Phys. J. C 23, 675 (2002)
Geant 4.9.3(E-50 spectrometer + Muon ID)
・ Inclusive Drell-Yan Pythia 6.4.26
・ BackgroundJAM 1.132
Event Generator Total Cross Section
Particle Transportation + Detector
might be several times larger
Yield Estimation
66
𝜋−p → 𝜇+𝜇−𝑛MX In E-50 Spectrometer + MuID
67
1.5 < Mμ+μ- < 2.9 GeV/c2π- beam 50 days
10 GeV 15 GeV 20 GeV
Beam Momentum
Nev
ent
(/0
.01
GeV
/c2)
Missing Mass MX (GeV/c2)
Nev
ent
(/0
.01
GeV
/c2)
Nev
ent
(/0
.01
GeV
/c2)
Missing Mass MX (GeV/c2) Missing Mass MX (GeV/c2)
Exclusive DY
Inclusive DY
Exclusive DY
Inclusive DY
BG BG BG
Exclusive DY
Inclusive DY
• The signal of exclusive Drell-Yan processes can be clearly identified in the missing mass spectrum of dimuon pairs.
• Because of the low event rate, this study could be accommodated into the E50 experiment.
S. Sawada (KEK)S. Kumano (KEK)J.C. Peng (UIUC)T. Sawada (AS)W.C. Chang (AS)
GPD(xB,Q2) in both space-like and time-like regime
68
J-PARC’s results in the time-like and large-Q2 region will be complementary to what to be obtained in space-like processes from the deeply virtual Compton scattering (DVCS) deeply virtual meson scattering (DVMS) process to be measured in JLab.
Large-Q2 region
10 GeV 15 GeV 20 GeV
π+ beam 150 days π- beam 50 days
Beam Momentum
(p+/p-) p → μ+ μ- Xd/u measurement with E-50 Spectrometer + MuID
𝑥2
𝑑/𝑢
𝑑/𝑢
𝑑/𝑢
𝑥2 𝑥2
Red lines : CTEQ6.6M
Inclusive DY
Statistics strongly depends on the prod. angle for
secondary beam 69
1.5 < Mμ+μ- < 2.9 GeV/c2
Experimental Difficulties of Detecting 𝜋−𝑝 → 𝐾0Λ(1405)• Multi-particle Acceptance:
• Background?
70
0
0
K (1405)
K
(1405)
pp
p p
p
-
+ -
+ +
+
+
Pion-Induced Exclusive Drell-Yan Process
2small ( )t q q -2large ( )t q q -
: pion distritribution amplitude (DA)p TDA : -N transistion distritribution amplitudep
•DA characterizes the minimal valence Fock state of hadrons.•DA of pion are also explored by pion-photon transition form factor in Belle and Barbar Exps.
•TDA characterizes the next-to-minimal valence Fock state of hadrons.•TDA of pion-nucleon is related to the pion cloud of nucleons.
Bernard Pire , IWHS2011
71
B. Pire, L. Szymanowski, Phys. Lett. B622 (2005) 83
Small cross sections
Exclusive Vector Boson Production
• 𝜋−p → γ∗𝑛
• 𝜋−p → γ∗∆0
• 𝜋−n → γ∗∆−
• 𝜋+n → γ∗p
• 𝜋+p → γ∗∆++
• 𝜋+n → γ∗∆+
• 𝜋−p → 𝐽/𝜓𝑛
• 𝜋−p → 𝐽/𝜓∆0
• 𝜋−n → 𝐽/𝜓∆−
• 𝜋+n → 𝐽/𝜓p
• 𝜋+p → 𝐽/𝜓∆++
• 𝜋+n → 𝐽/𝜓∆+
72
Dark Photon A’
74
p-
LH2-target
Ring ImageCherenkovCounter
Internal DC
FM magnet
ps-
K+
Fiber tracker
Beam GC
Internal TOF
Internal TOFDC
TOF wall
2m
Decay p(p+)
20 GeV/cBeam p-
Acceptance: ~ 60% for D*, ~80% for decay p+
Resolution: p/p~0.2% at ~5 GeV/c (Rigidity: ~2.1 Tm)
||<60
Scintillator Muon trigger device
+
-
'A
Summary (I)
• High-energy hadron beam at J-PARC is ideal for studying hard exclusive processes.
• The study of 𝜋-induced DY/charm production and hard exclusive processes will offer important understanding on
• Nucleon structure: valence quarks PDF; TMD (BM), GPD (TDA)
• 𝜋 structure: DA and PDF
• Structure of exotic hadrons
• 𝑱/𝝍 production mechanism, exotic charmed baryons
75
Summary (II)
• Spectrometer with large acceptance and good mass resolution is required for the measurement and such measurement in E-50 conceptual detectors seems promising.
• Availability of deuterium target together with the detection of recoiled protons will enable the measurement of flavor separation of BM functions , valance-quark distributions at large-x and search for some exotic charmed baryons.
• More collaborators are critically necessary!
76
Questions
• Will the factorization of exclusive DY process based on a crossing symmetry of DVMP process be a major concern?
• What is the relationship between the inclusive DY process at xF 1 limit and the exclusive one? If these two processes are different, how to differentiate them experimentally, e.g. the missing mass or angular distribution of dimuon pairs?
• What is the relationship between the inclusive J/psi production process at xF 1 limit and the exclusive one?
77
top related