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Charmedmesonmassesinmediumbasedoneffec1vechiralmodels
MasayasuHarada(NagoyaUniversity)@ KEKtheorycenterworkshopon
HadronandNuclearPhysicsin2017(KEK,JAPAN,January9,2017)
Basedon• M.Harada,Y.L.Ma,D.Suenaga,Y.Takeda,arXiv:1612.03496• D.Suenaga,M.Harada,Phys.Rev.D93,076005(2016).• D.Suenga,B.-R.He,Y.L.Ma,M.Harada,Phys.Rev.D91,036001(2015)• D.Suenaga,B.-R.He,Y.L.Ma,M.Harada,Phys.Rev.C89,068201(2014)• D.Suenaga,S.Yasui,M.Harada,inprepara1on
2017/1/9 HadronandNuclearPhysicsin2017@KEK 1
1.Introduc,on
2017/1/9 HadronandNuclearPhysicsin2017@KEK 2
OriginofMass ?ofHadrons
ofUs
OneoftheInteres,ngproblemsofQCD=
2017/1/9 HadronandNuclearPhysicsin2017@KEK 3
PhasediagramofQuark-Gluonsystem
Highdensity
NeutronStar
hightemperature
1 trillion kelvin
100 million ton/cm3
• SpontaneousChiralSymmetryBreaking• ConfinementofQuarks
• ChiralSymmetryRestra,on• DeconfinementofQuarks
EarlyUniverse
2017/1/9 HadronandNuclearPhysicsin2017@KEK 4
Q “Light-quark cloud” (Brown Muck) ・・・ made of light quarks and gluons typical energy scale ~ ΛQCD
☆ Heavy-Light Mesons (Qq type) Baryons (Qqq) -
◎ Heavy mesons ・・・ 3 or 3bar, … of SU(3)l ◎ Heavy baryons ・・・ 6, … of SU(3)l
Flavor representations, which do not exist in the light quark sector, give a new clue to understand the hadron structure.
<<MQ
Heavy-lighthadronsasprobesofvacuumstructue
2017/1/9 Hadron and Nuclear Physics in 2017 @ KEK
5
• In this talk, I will summarize main points of a series of papers, in which we studied spectra of charmed mesons in nuclear matter.
Outline1. Introduc1on2. D-D*mixinginspin-isospincorrelatedmaeer
D.Suenaga,B.-R.He,Y.L.MaandM.Harada,Phys.Rev.C89,068201(2014)3. Dispersionrela1onsofcharmedmesonsinspin-isospin
correlatedmaeerD.Suenaga,M.Harada,PhysicalReviewD93,076005(2016)
4. Effectsofpar1alchiralsymmetryrestora1oninnuclearmaeertoeffec1vemassesofcharmedmesonsM.Harada,Y.L.Ma,D.Suenaga,Y.Takeda,arXiv:1612.03496D.Suenaga,B.-R.He,Y.L.MaandM.Harada,Phys.Rev.D91,036001(2015)
5. Modifica1onofspectralfunc1onofcharmedmesonsinnuclearmaeerD.Suenaga,S.Yasui,M.Harada,inprepara1on
6. Summary
2017/1/9 HadronandNuclearPhysicsin2017@KEK 6
seePosterbyD.Suenaga
2.D-D*mixinginspin-isospincorrelatedmaeerD.Suenaga,B.-R.He,Y.L.MaandM.Harada,Phys.Rev.C89,068201(2014)
7 2017/1/9 HadronandNuclearPhysicsin2017@KEK
dualchiraldensitywave(DCDW)• NakanoandTatsumishowedtheexistenceoftheDCDWphasewith
inhomogeneouschiralcondensate(Nakano-Tatsumi,PRD71,114006(2005))inthehighdensitymaeer.
qq x!"( ) = σ x
!"( )+ iπ 3 x
!"( )τ 3
=φ cos 2αx( )+ iτ 3φ sin 2αx( )
2017/1/9 HadronandNuclearPhysicsin2017@KEK 8
• Ananalysisusinganeffec1vehadronmodelin[A.Heinz,F.Giacosa,D.Rischke,NPA93,34(2015)]showedthatthephasetransi1ontotheinhomogeneousphaseoccursatthedensityof2.41mesofnormalnuclearmaeerdensity.
position dependent pion condensation• Spin-isospin correlation in the nuclear medium will
cause the position dependent pion condensation. • In the equilibrium case, the pion condensation does
not depend on the time.
• We are interested in the mass spectrum of charmed
mesons, so that we take the spatial components of the residual momentum of charmed mesons to be zero.
• Only the space average of α⊥ contributes.
α⊥0A x!"( ) = α||0
A x!"( ) = 0
α⊥iA = d 3x
V∫ α⊥iA x!"( ) : α⊥i
A =1fπ∂iπ
A +# P-wave pion condensation
•α⊥µA =
1fπ∂µπ
A +! ; chiral field for pion
• π 3 x!"( )=φ sin 2αx( ) leads to α⊥i
A =αδi 3δa3
2017/1/9 Hadron and Nuclear Physics in 2017 @ KEK 9
D-D*mixing• P-wavepioncondensa1ongivesamixingbetweenD(JP=0-)andD*(JP=1-),aswellasamixingbetween2modesofD*.
2017/1/9 HadronandNuclearPhysicsin2017@KEK 10
Lint = �igAMD̄⇤µ ↵
µ? D � igA✏
µ⌫��D̄⇤µ↵?⌫@�D
⇤�
α⊥µ =1fπ∂µπ +!
causesamixingbetweenDandD*mesons
causesamixingbetweendifferentmodesofD*mesons
Mass spectrum in the heavy quark limit
4 states (2 HQ pairs) : (+,+) and (-,-) related by Z2
0 100 200 300 400!150
!100
!50
0
50
100
150
!Α! "MeV#
Mass"Me
V#
U(1)s X U(1)I X Z2 [subgroup of SU(2)spin X SU(2)isospin] exists.
4 states (2 HQ pairs) : (+,-) and (-,+) related by Z2
2017/1/9 Hadron and Nuclear Physics in 2017 @ KEK 11
• α⊥iA =αδi 3δa3
There are 8 states at vacuum, which are degenerated due to the existence of the heavy quark symmetry D+ and D0, D*+ (3 states) and D*0 (3 states)
Inclusion of mass difference at the vacuum
• We include the violation of the heavy quark symmetry by the mass difference between D and D* mesons at vacuum.
• Meson spin denoted by SU(2)J together with the isospin SU(2)I is conserved at vacuum.
• In the spin-isospin correlated matter, the SU(2)J X SU(2)I is broken to a subgroup depending on the symmetry structure of the correlation.
2017/1/9 Hadron and Nuclear Physics in 2017 @ KEK
12
Inclusion of mass difference at the vacuum
• SU(2)J X SU(2)I → U(1)J X U(1)I X Z2 Ø 8 states are split into 4 pairs of Z2 symmetry. Ø 2 D mesons provide 1 pair {(0,+), (0,-) } Ø 6 D* provide 3 pairs :
Ø {(0,+), (0,-)}, {(+,+), (-,-)}, {(+,-), (-,+)}. Ø 2 of {(0,+), (0,-)} are mixed with each other
1 pair0 100 200 300 400
1700
1800
1900
2000
2100
2200
!Α! "MeV#
Mass"Me
V#
1 pair1 pair1 pair
2017/1/9 Hadron and Nuclear Physics in 2017 @ KEK 13
3.Dispersionrela1onsofcharmedmesonsinspin-isospincorrelatedmaeerD.Suenaga,M.Harada,PhysicalReviewD93,076005(2016)
14 2017/1/9 HadronandNuclearPhysicsin2017@KEK
Chiralpartnerstructureforcharmedmesons
• 2heavyquarkmul1pletswithJl=1/2areregardedasthechiralpartner:
• Massdifferenceisgeneratedbythechiralcondensate,andthevalueisroughlyequaltothecons1tuentquarkmass.
• Experimentalvalueimpliesthatthechiralpartnerstructureseemstowork:
D(0−),D *(1−)"# $% chiral partner← →(((( D0*(0+),D1(1
+)"# $%
• M.A.Nowak,M.RhoandI.Zahed,PRD48,4370(1993)• W.A.BardeenandC.T.Hill,PRD49,409(1994)
m 0+( )−m 0−( ) ≈m 1+( )−m 1−( ) ≈ 0.43GeV2017/1/9 HadronandNuclearPhysicsin2017@KEK 15
Aneffec1veLagrangian• Weconstructedaneffec1veLagrangianoftherela1vis1cformbased
ontheheavyquarksymmetryandthechiralpartnerstructure.• ThefreeLagrangianandtheinterac1onwithσareexpressedas:
• Spontaneouschiralsymmetrybreakingatzerodensityleadstothevacuumexpecta1onvalue(VEV)oftheσfieldas<σ>=σ0,whichcausesthemassdifferencebetweenthechiralpartners.
• Then,thecouplingofσtotheheavymesonsarerelatedtothemassdifference(anextendedGoldberger-Treimanrela1on):
heavyquarksymemtry
heavyquarksymemtry
Lfree+� = @µD̄@µD̄† �✓m2��m2
2
�
�0
◆D̄D̄†
+ @µD̄⇤@µD̄⇤† �
✓m2��m2
2
�
�0
◆D̄⇤D̄⇤†
+ @µD̄⇤0@
µD̄⇤†0 �
✓m2+
�m2
2
�
�0
◆D̄⇤
0D̄⇤†0
+ @µD̄1@µD̄†
1 �✓m2+
�m2
2
�
�0
◆D̄1D̄
†1
chiralsymmetry
G�DD =�m2
2�0, . . .2017/1/9 HadronandNuclearPhysicsin2017@KEK 16
Klein-Gordonequa1onsatvacuum• Wedeterminethedispersionsrela1onsofD,D*,D0*,D1bysolvingthecoupledequa1onsofmo1on.
• Theequa1onsofmo1onatvacuumareordinaryKlein-Gordonequa1ons.
– Theheavyquarksymmetryimpliesmassdegeneracy.
– Thechiralsymmetrybreakinggeneratesthemassdifferences:
MD(0�) = MD⇤(1�) ; MD⇤0 (0
+) = MD1(1+)
2
664�@µ@
µ +m2�
0
BB@
11
11
1
CCA+�m2
2
0
BB@
�1�1
11
1
CCA
3
775
0
BB@
D̄(0�)D̄⇤(1�)D̄⇤
0(0+)
D̄1(1+)
1
CCA = 0
⇥MD⇤
0 (0+)
⇤2 �⇥MD(0�)
⇤2=
⇥MD1(1+)
⇤2 �⇥MD⇤(1�)
⇤2= �m2
2016/07/11 Seminar@RCNP 17
Poten1alintheDCDW
• Thepoten1alinthematrixformisexpressedas
V =
0
BB@
�V� �iV@⇡ iV⇡ V@�
iV@⇡ �V� V@� iV⇡
�iV⇡ �V@� V� iV@⇡
�V@� �iV⇡ �iV@⇡ V�
1
CCA
– Eachcomponentisgivenby
V� =
�m
2
2
�
�0cos(2fx) , V⇡ =
�m
2
2
�
�0sin(2fx)
V@� = �2fgm
�
�0sin(2fx) , V@⇡ = 2fgm
�
�0cos(2fx)
2016/07/11 Seminar@RCNP 18
2017/1/9 HadronandNuclearPhysicsin2017@KEK 19
• Theseeffectsareincludedintheequa1onsofmo1onasapoten1alobtainedbyreplacingtheσandπfieldsintheLagrangianas
– Here,xisoneofthe3direc1onsofthespace,fisafrequencyofthedensitywave,andφisastrengthofthecondensate
Poten1albyσandπmesonsintheDCDW
D
D0*
π
D
D
σ
D0*
D0*
σ…
D
D*
π…
�(x) = � cos(2fx) ; ⇡
3(x) = � sin(2fx)
• Dmesonsgetmediumcorrec1onsintheDCDWthroughtheexchangeofσandπmesons.
Dispersionrela1onswithnoD*Dπinterac1on• 4modesappearfrom(D,D0
*)sector(2par1clesatvacuum)
E2 = m2 +1
2
⇥(q
x
+ 2f)2 + q2x
⇤+ k2
y
+ k2z
± 1
2
s
[(qx
+ 2f)2 � q2x
]2 + 4�m2�2
�20
E2 = m2 +1
2
⇥q2x
+ (qx
� 2f)2⇤+ k2
y
+ k2z
± 1
2
s
[q2x
� (qx
� 2f)2]2 + 4�m2�2
�20
1.95
2.05
2.15
2.25
2.35
2.45
2.55
2.65
2.75
-1000 -600 -200 200 600 1000
E [GeV]
qx [MeV]
f=400MeV(kx=ky=0)
freeD0*
· Group velocity : vx
=
dE
dqx
����q
x
=k
y
=k
z
=0
vx
=
f
E
2
41± 4f2
q16f4
+
�
2(�m
2)2
�
20
3
5 > 0
vx
= � f
E
2
41± 4f2
q16f4
+
�
2(�m
2)2
�
20
3
5 < 0
• For-f<qx<0or0<qx<f,vx∝-qx• Minimumenergyatqx=forqx=-f• Only4modesinsteadofinfinitemodesfor
usualBloch’streatment.• Noenergygaps.
2017/1/9 HadronandNuclearPhysicsin2017@KEK 20graycurve:freeD
Effectsofchiralsymmetryrestora1on• Weconsidertheeffectsofchiralsymmetryrestora1onbyreducingφ:
2017/1/9 HadronandNuclearPhysicsin2017@KEK 21
qq x!"( ) = σ x
!"( )+ iπ a x
!"( )τ a =φ cos 2 f x( )+ iτ 3φ sin 2f x( )
1.95
2.05
2.15
2.25
2.35
2.45
2.55
-1000 -600 -200 200 600 1000
E [GeV]
qx [MeV]
1.95
2.05
2.15
2.25
2.35
2.45
-1000 -600 -200 200 600 1000
E [GeV]
qx [MeV]
1.95
2.05
2.15
2.25
2.35
2.45
-1000 -600 -200 200 600 1000E [GeV]
qx [MeV]
1.95
2.05
2.15
2.25
2.35
2.45
-1000 -600 -200 200 600 1000
E [GeV]
qx [MeV]
f = 200MeV ;�
�0= 1
�
�0= 0.6
�
�0= 0.3
�
�0= 0f = 200MeV ;
�
�0= 1
�
�0= 0.6
�
�0= 0.3
�
�0= 0f = 200MeV ;
�
�0= 1
�
�0= 0.6
�
�0= 0.3
�
�0= 0f = 200MeV ;
�
�0= 1
�
�0= 0.6
�
�0= 0.3
�
�0= 0
• Asthevalueofφbecomessmall,theredandgreencurvesmoveup,andtheorangeandbluecurvesmovedown.
• Forφ=0,thereareonly2modeswhichhaveadegeneratedispersionrela1on,reflec1ngthechiralsymmetryrestora1on.Notethat2modesdisappearsincetheeigenvectorsvanish.
Dispersionrela1onswithD*Dπinterac1onincluded• Allof(D,D*,D0*,D1)mix.WecansolvethecoupledEoManaly1cally.• 8modesappear,whichiscomparedwith4modesatvacuum.
2017/1/9 HadronandNuclearPhysicsin2017@KEK 22
1.85
1.95
2.05
2.15
2.25
2.35
2.45
2.55
2.65
-1000 -600 -200 200 600 1000
E [GeV]
qx [MeV]• f=200MeV(g=0.5)• Forallthemodes,vx∝-qx.• Minimumenergyisrealizedatqx=for
qx=-f.
1.80 1.90 2.00 2.10 2.20 2.30 2.40 2.50 2.60 2.70 2.80
-1000 -600 -200 200 600 1000
E [GeV]
qx [MeV]• f=400MeV(g=0.5)• Levelcrossingoccursbetweenred
doeedandorangesolidcurves
• ThespliungbetweenasolidcurveandadoeedcurvewiththesamecoloriscausedbythemixingbetweenDandD*mesonsaswellasthemixingbetweenD0*andD1mesons.
4.Effectsofpar,alchiralsymmetryrestora,oninnuclearmaKertoeffec,vemassesofcharmedmesons
M.Harada,Y.L.Ma,D.Suenaga,Y.Takeda,arXiv:1612.03496D.Suenaga,B.-R.He,Y.L.MaandM.Harada,Phys.Rev.D91,036001(2015)
2017/1/9 HadronandNuclearPhysicsin2017@KEK 23
Par1alchiralsymmetryrestora1oninnuclearmaeer
• Itisexpectedthatthechiralsymmetryispar1allyrestoredinnuclearmaeer:– e.g.inlineardensityapproxima1on
2017/1/9 HadronandNuclearPhysicsin2017@KEK 24
f⇤⇡
f⇡= 1� �⇡N
m2⇡f
2⇡
⇢B0 1
⇢B/⇢0
• Anexperimentshowedthedecreasingoffπinmaeer– K.Suzukietal.,PRL92,072302(2004)
f⇤⇡(⇢B)
f⇡
�2' 0.64 at ⇢B = ⇢0
Massesofcharmedmesonsinnuclearmaeer
2017/1/9HadronandNuclearPhysicsin2017@KEK
25
• Effec1vemassesforD(JP=0-),D(JP=0+)innuclearmaeer
m(e↵)D(�) = m� 1
2�M
h�if⇡
+ g!DD h!0i
m(e↵)D(+) = m+
1
2�M
h�if⇡
+ g!DD h!0i
• Effec1vemassesforan1-charmedmesons
D
D
σD
D
ω
m(e↵)D̄(�)
= m� 1
2�M
h�if⇡
� g!DD h!0i
m(e↵)D̄(+)
= m+1
2�M
h�if⇡
� g!DD h!0i
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.41900
2000
2100
2200
2300
2400
2500
ΡB!Ρ0
EffectiveMass"MeV#
mG"eff#
mH"eff#
mG"eff#
mH"eff#
g!DDg!NN > 0
g!DDg!NN < 0
Effec1vemassesinlineardensityapproxima1on
26
h!0i =g!NN
m2!
⇢B ,h�ih�i0
= 1� �⇡N
m2⇡f
2⇡
⇢Bm(e↵)
D(�) = m� 1
2�M
h�if⇡
+ g!DD h!0i
m(e↵)D(+) = m+
1
2�M
h�if⇡
+ g!DD h!0i
Anexample
g!DDg!NN > 0
g!DDg!NN < 0
⇢B/⇢0
m(e↵)D̄(�)
= m� 1
2�M
h�if⇡
� g!DD h!0i
m(e↵)D̄(+)
= m+1
2�M
h�if⇡
� g!DD h!0i
2017/1/9 HadronandNuclearPhysicsin2017@KEK
|g!DD| = 3.7 , |g!NN | = 6.23 , �⇡N = 45MeV
D̄(+) D(+)
D(+) D̄(+)
D̄(�) D(�)
D(�) D̄(�)
Increasingordecreasingofpseudo-scalarD(-)mesonmassonlyisnotenoughformeasuringthepar1alchiralsymmetryrestora1on.
Par1alchiralsymmetryrestora1on
2017/1/9 HadronandNuclearPhysicsin2017@KEK 27
m(e↵)D(�) = m� 1
2�M
h�if⇡
+ g!DD h!0i
m(e↵)D(+) = m+
1
2�M
h�if⇡
+ g!DD h!0i
m(e↵)D̄(�)
= m� 1
2�M
h�if⇡
� g!DD h!0i
m(e↵)D̄(+)
= m+1
2�M
h�if⇡
� g!DD h!0i
h!0i =g!NN
m2!
⇢B ,h�ih�i0
= 1� �⇡N
m2⇡f
2⇡
⇢B
D(+)�D(�)
• Inaddi1ontostudythemassdifferenceofchiralpartners,takingaverageofpar1cleandan1-par1clewillgiveaclueforpar1alchiralsymmetryrestora1on.
• Thresholdenergyforproduc1onofDandan1-Dmesonpairinmediumislargerthanvacuumreflec1ngthepar1alchiralsymmetryrestora1on.
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.40
100
200
300
400
500
ΡB!Ρ
EffectiveM
assDifference"MeV#
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.41900
2000
2100
2200
2300
2400
2500
ΡB!Ρ0
EffectiveM
ass"MeV#
"mG"eff#"m
G"eff##!2
"mH"eff#"m
H"eff##!2
D(+) + D̄(+)
D(�) + D̄(�)
Nuclearmaeerfromaparitydoubletmodel
2017/1/9 HadronandNuclearPhysicsin2017@KEK 28
• In[Y.Motohiro,Y.Kim,M.Harada,Phys.Rev.C92,025201(2015)],weconstructedameanfieldmodelofWaleckatype,usingaparitydoubletmodelfornucleon,whichreproducestheproper1esofnuclearmaeeratnormalnuclearmaeerdensity.
• Hereweusethemodeltodeterminethemeanfieldsofsigmaandomega. g!DD < 0
m(e↵)D(�) = m� 1
2�M
h�if⇡
+ g!DD h!0i
m(e↵)D(+) = m+
1
2�M
h�if⇡
+ g!DD h!0i
m(e↵)D̄(�)
= m� 1
2�M
h�if⇡
� g!DD h!0i
m(e↵)D̄(+)
= m+1
2�M
h�if⇡
� g!DD h!0i
g!DD > 0
Densitydependenceisquitesimilartotheoneinthelineardensityapproxima1on.
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.41800
2000
2200
2400
2600
ΡB!Ρ0
EffectiveM
ass"Me
V#
mG"eff#
mH"eff#
mG"eff#
mH"eff#
D̄(+) D(+)
D(+) D̄(+)
D̄(�) D(�)
D(�) D̄(�)
σ
density
d 3x∫ σ
NuclearmaeerfromSkyrmecrystal
2017/1/9 HadronandNuclearPhysicsin2017@KEK 29
• Y. –L. Ma, M. Harada, H.K. Lee, Y. Oh, B. –Y. Park, M. Rho, PRD88 (2013) 014016 • Y. –L. Ma, M. Harada, H.K. Lee, Y. Oh, B. –Y. Park, M. Rho, PRD90 (2014) 34105 • M. Harada, H.K. Lee, Y.-L. Ma, M. Rho, PRD91, (2015) 096011 • D.Suenga, B.R.He, Y.L.Ma. M.Harada, PRD 91, 036001 (2015)
• IntheSkyrmecrystalmodel,thereexiststhe“half-Skyrmionphase”,wherethespaceaverageofthesigmacondensatevanishes.
g!DD < 0g!DD > 0
Chiralpartnersaredegeneratewitheachotherinthehalf-Skyrmionphase.Proper1esinthenormalnuclearmaeeraresimilartotheothercases.
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.41900
2000
2100
2200
2300
2400
2500
ΡB!Ρ0
EffectiveM
ass"Me
V#
mG"eff#
mH"eff#
mG"eff#
mH"eff#
D̄(+) D(+)
D̄(�) D(�)
D(+) D̄(+)
D(�) D̄(�)
5.Modifica,onofspectralfunc,onofcharmedmesonsinnuclearmaKer
D.Suenaga,S.Yasui,M.Harada,inprepara1on
2017/1/9 HadronandNuclearPhysicsin2017@KEK 30
Inclusionoffluctua1onmodes• Weincludethefluctua1onmodesofσandπtostudythespectralfunc1onofcharmedmesons.
2017/1/9 HadronandNuclearPhysicsin2017@KEK 31
- modifications of and are calculated by following diagrams
tree level one loop corrections
- meson propagators must be resummed ones to maintain chiral symmetry:
Modifica1onofmasses
2017/1/9 HadronandNuclearPhysicsin2017@KEK 32
� � � � ��
� � � � ��
� � � � � �
� � � � � �
0.02 0.04 0.06 0.08 0.10� [/fm3]
1900
2000
2100
2200
2300
Mass [MeV]
- Mass of and are not changed from mean field level
D̄ D̄⇤0
or : or meson mass with mean fieldD̄or : or meson mass with one loops
D̄⇤0
D̄ D̄⇤0
Spectralfunc1on
① LandaudampingPosi1onmovestohigherenergyregion.Hightisenhanced
② ThresholdenhancementPosi1onmovestohigherenergyregion.Hightisenhanced.
③ DecayofD*0→DπCollisionalbroadening.Posi1onmovestolowerenergyregion.
2017/1/9 HadronandNuclearPhysicsin2017@KEK 33
1900 2000 2100 2200 2300 24000.00000
2.×10-6
4.×10-6
6.×10-6
8.×10-6
0.00001
q0 [MeV]
�(q 0,0�
)[/MeV
2 ]
1900 2000 2100 2200 2300 24000.00000
2.×10-6
4.×10-6
6.×10-6
8.×10-6
0.00001
q0 [MeV]
�(q 0,0�)[/MeV
2 ]1900 2000 2100 2200 2300 2400
0.00000
2.×10-6
4.×10-6
6.×10-6
8.×10-6
0.00001
q0 [MeV]
�(q 0,0�
)[/MeV
2 ]
① ①①
②
② ②③
③③
ρB/ρ0=0.23ρB/ρ0=0.41 ρB/ρ0=0.51
6.Summary• Weproposedtostudythemassspectrumofheavy-light
mesonstoprobethesymmetrystructureofnuclearmaeer.• Existenceofspin-isospincorrela1ongeneratesamixing
amongDandD*mesons.• Inaddi1ontostudythemassdifferenceofchiralpartners,
takingaverageofpar1cleandan1-par1clewillgiveaclueforpar1alchiralsymmetryrestora1on.
• Thresholdenergyforproduc1onofDandan1-Dmesonpairinmediumislargerthanvacuumreflec1ngthepar1alchiralsymmetryrestora1on.
• Spectralfunc1onisalsomodifiedbytheeffectofpar1alchiralsymmetryrestora1on.
• Ourresultsimplythatstudyingcharmedmesonspectrumwillgivecluestounderstandthechiralsymmetrystructureofnuclearmaeer.
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